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Maxwell D, Praetorius RT. "Gutting It Out" Does Not Work: Why Mental Health Days are Needed. Soc Work Public Health 2024; 39:221-233. [PMID: 38426694 DOI: 10.1080/19371918.2024.2322589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
College student mental health issues negatively impact academic performance. Over half of college students in the U.S. report a mental health issue, with 60% reporting one at the two-year mark. Even when aware of such mental health issues, students are still hesitant to seek treatment. As such, investigating perceptions of mental health time off may illuminate perceived usefulness of such policies as well as potential processes for defining and implementing such policies. This study sought to answer the question, "What are the perspectives of time-off for mental health?" Using Reddit's responses, this study extracted (N = 392) quotes and used thematic analysis to identify four main themes. Implications include the need for school-level mental health time-off policies or integration of instructors' policies into their syllabi for transparency to students, which may alleviate student stress and further stigmatization.
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Affiliation(s)
- December Maxwell
- Thompson School of Social Work & Public Health, University of Hawaii at Manoa, Honolulu, HI, USA
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2
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Maxwell D, Conrad P. Women are the thread: Keetoowah elders' experiences of becoming a mother. Cult Health Sex 2023; 25:1355-1370. [PMID: 36527451 DOI: 10.1080/13691058.2022.2156618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Becoming a mother can simultaneously be a shared experience while having cultural distinctions. Indigenous motherhood, for example, has been heavily influenced by colonisation, medicalisation and Western imperialism. Historical and generational trauma has contributed to shifts in Indigenous practices surrounding becoming a mother and a disconnection from traditional birthing practices that has impacted maternal mental health. Nevertheless, recovering traditions can be beneficial for contemporary Indigenous mothers. This study utilised a culturally appropriate method, Story Inquiry. Using this approach, the paper coalesces community stories about a health challenge across time to better understand elders' experiences of becoming a mother in one Indigenous tribe, the United Keetoowah Band of Cherokee. The results of this inquiry illustrate the acute effects of colonialism and the historical trauma that resulted from it on Keetoowah experiences of Becoming a Mother and the cultural transmission of practices and beliefs surrounding maternal role transition. At the same time, it demonstrates the strategies that have shaped women's experiences of motherhood and made possible community persistence: especially the relationships between female kin within the Keetoowah tribe that have been integral to tribal resilience. Findings stress the value of healthcare approaches that include cultural traditions surrounding becoming a mother and more culturally informed perinatal care.
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Affiliation(s)
- December Maxwell
- Thompson School of Social Work & Public Health, The University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - Paul Conrad
- History, The University of Texas at Arlington, Arlington, Texas, USA
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Maxwell D, Thomas J, Plassmeyer M. The dynamics of providing street medicine to a geographically diverse homeless population in Hawaii. J Evid Based Soc Work (2019) 2023; 20:743-764. [PMID: 37461307 DOI: 10.1080/26408066.2023.2211067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
PURPOSE Since Hawaii has the highest rate of per capita of persons experiencing homelessness (PEH) in the United States, the purpose of this qualitative evaluation study was to evaluate the experiences of both the providers and clients of a Street Medicine (SM) program serving one side of the island of O'ahu. METHOD This evaluation used Story Inquiry to qualitatively assess one SM program serving one side of the island of O'ahu in Hawa'i. Since the culture in Hawaii is largely based upon stories, a qualitative approach was taken to better understand the lived experiences of PEH who utilized the SM services, as well as provider perspectives. RESULTS The findings of this evaluation include strengths of increased primary care engagement and improved quality of life for PEH; barriers to success included transportation scarcity and limitations of services available. CONCLUSIONS The findings lend implications for new SM programs, including gathering community support, having culturally aware outreach and that mobility and flexibility can overcome health-care barriers for PEH.
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Affiliation(s)
- December Maxwell
- Thompson School of Social Work & Public Health, The University of Hawai'i at Manoa, Honolulu, United States
| | - Johanna Thomas
- School of Social Work, The University of Arkansas, Honolulu, United States
| | - Mark Plassmeyer
- School of Social Work, The University of Arkansas, Honolulu, United States
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Anderson EK, Baker CJ, Bertsche W, Bhatt NM, Bonomi G, Capra A, Carli I, Cesar CL, Charlton M, Christensen A, Collister R, Cridland Mathad A, Duque Quiceno D, Eriksson S, Evans A, Evetts N, Fabbri S, Fajans J, Ferwerda A, Friesen T, Fujiwara MC, Gill DR, Golino LM, Gomes Gonçalves MB, Grandemange P, Granum P, Hangst JS, Hayden ME, Hodgkinson D, Hunter ED, Isaac CA, Jimenez AJU, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Madsen N, Martin L, Massacret N, Maxwell D, McKenna JTK, Menary S, Momose T, Mostamand M, Mullan PS, Nauta J, Olchanski K, Oliveira AN, Peszka J, Powell A, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Schoonwater J, Silveira DM, Singh J, Smith G, So C, Stracka S, Stutter G, Tharp TD, Thompson KA, Thompson RI, Thorpe-Woods E, Torkzaban C, Urioni M, Woosaree P, Wurtele JS. Observation of the effect of gravity on the motion of antimatter. Nature 2023; 621:716-722. [PMID: 37758891 PMCID: PMC10533407 DOI: 10.1038/s41586-023-06527-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/09/2023] [Indexed: 09/29/2023]
Abstract
Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.
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Affiliation(s)
- E K Anderson
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK.
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK.
| | - N M Bhatt
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - G Bonomi
- University of Brescia, Brescia and INFN Pavia, Pavia, Italy
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - I Carli
- TRIUMF, Vancouver, British Columbia, Canada
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - A Christensen
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - R Collister
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Cridland Mathad
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - D Duque Quiceno
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - S Eriksson
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - A Evans
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - S Fabbri
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Accelerator and Technology Sector, CERN, Geneva, Switzerland
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
| | - A Ferwerda
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - L M Golino
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - M B Gomes Gonçalves
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - P Granum
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - E D Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - S A Jones
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Groningen, The Netherlands
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physics, British Columbia Institute of Technology, Burnaby, British Columbia, Canada
| | - N Madsen
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - L Martin
- TRIUMF, Vancouver, British Columbia, Canada
| | | | - D Maxwell
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - J T K McKenna
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Momose
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - M Mostamand
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - P S Mullan
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
- Institute for Particle Physics and Astrophysics, ETH, Zurich, Switzerland
| | - J Nauta
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - A N Oliveira
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J Peszka
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
- Institute for Particle Physics and Astrophysics, ETH, Zurich, Switzerland
| | - A Powell
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Accelerator Systems Department, CERN, Geneva, Switzerland
| | - E Sarid
- Soreq NRC, Yavne, Israel
- Department of Physics, Ben Gurion University, Beer Sheva, Israel
| | - J Schoonwater
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - J Singh
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - G Smith
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - C So
- TRIUMF, Vancouver, British Columbia, Canada
| | | | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- School of Mathematical and Physical Sciences, University of Sussex, Brighton, UK
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - K A Thompson
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - E Thorpe-Woods
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - C Torkzaban
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - M Urioni
- University of Brescia, Brescia and INFN Pavia, Pavia, Italy
| | - P Woosaree
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
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Maxwell D, Seo JY, Stotzer RL. The Effects of COVID-19 on Choosing to Have Children in the State of Hawai'i. Hawaii J Health Soc Welf 2023; 82:141-143. [PMID: 37304897 PMCID: PMC10248818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- December Maxwell
- Department of Social Work, Thompson School of Social Work and Public Health, University of Hawai'i at Mānoa, Honolulu, HI
| | - Jin Young Seo
- Department of Social Work, Thompson School of Social Work and Public Health, University of Hawai'i at Mānoa, Honolulu, HI
| | - Rebecca L Stotzer
- Department of Social Work, Thompson School of Social Work and Public Health, University of Hawai'i at Mānoa, Honolulu, HI
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Maxwell D, Mauldin R, Thomas J, Holland V. American Indian Motherhood and Historical Trauma: Keetoowah Experiences of Becoming Mothers. Int J Environ Res Public Health 2022; 19:ijerph19127088. [PMID: 35742333 PMCID: PMC9222731 DOI: 10.3390/ijerph19127088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 12/27/2022]
Abstract
Background: American Indian/Alaskan Native (AI/AN) women disproportionally experience postpartum depression in the United States as compared to the rest of the population. Despite being disproportionately represented, the current body of knowledge lacks research on depression in this particular population. Specifically, the current literature lacks research pertaining to the experiences of postpartum AI/AN women, their culture, birthing and mothering expectations, and trauma. This qualitative study used the theories of becoming a mother, historical-trauma framework, and reproductive justice as they relate to Indigenous women’s personal and historical trauma to assess their lived experiences of becoming a mother. Methods: Keetoowah mothers (N = 8) were interviewed by using a story inquiry method to understand the perinatal experiences of members of one Indigenous tribe in the US. Findings: The story inquiry coding resulted in two main themes, namely maternal mental health challenges and inadequacies of perinatal care. Conclusion: The subthemes illuminate the intersection of historical trauma and the perinatal experience, continued colonization of mothering, and the resilience of tribal culture during the postpartum period. Implications include advocacy for increasing culturally derived perinatal interventions, increased healthcare coverage of culturally appropriate birthing practices, and future research evaluating the correlation between historical trauma and maternal mental health challenges.
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Affiliation(s)
- December Maxwell
- Thompson School of Social Work & Public Health, University of Hawaii at Manoa, Honolulu, HI 96822, USA
- Correspondence:
| | - Rebecca Mauldin
- School of Social Work, The University of Texas at Arlington, Arlington, TX 76019, USA;
| | - Johanna Thomas
- School of Social Work, University of Arkansas at Fayetteville, Fayetteville, AR 72701, USA;
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7
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Umolu AG, Venn R, Maxwell D, Al Shiekh Ali Z, Howlett DC. Hyperechoic kidneys in a patient with bronchiectasis. Ultrasound 2021; 29:260-263. [PMID: 34777546 DOI: 10.1177/1742271x21989064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/30/2020] [Indexed: 11/16/2022]
Abstract
Introduction Hyperechoic renal cortex in a normal-sized kidney has a range of causes, some of which irreparably damage the kidney and should initiate further investigations. Case Report We present a 72-year-old woman with longstanding bronchiectasis, noticed to have worsening renal function. Renal tract ultrasonography showed hyperechoic normal-sized kidneys. Renal biopsy confirmed amyloidosis. Discussion Imaging findings in renal amyloidosis tend to be non-specific and are not always present. However, ultrasonography findings of hyperechoic cortex in normal-sized kidneys should not be ignored. Conclusion Renal impairment from blood chemistry in addition to hyperechoic kidneys may be the key to diagnosing secondary amyloidosis in a patient with bronchiectasis, a rare association but important to recognise.
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Affiliation(s)
- A G Umolu
- Department of Radiology, East Sussex Healthcare NHS Trust, East Sussex, UK
| | - R Venn
- Department of Respiratory Medicine, East Sussex Healthcare NHS Trust, East Sussex, UK
| | - D Maxwell
- Department of Respiratory Medicine, East Sussex Healthcare NHS Trust, East Sussex, UK
| | - Z Al Shiekh Ali
- Department of Histopathology, East Sussex Healthcare NHS Trust, East Sussex, UK
| | - D C Howlett
- Department of Radiology, East Sussex Healthcare NHS Trust, East Sussex, UK
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8
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Baker CJ, Bertsche W, Capra A, Cesar CL, Charlton M, Mathad AC, Eriksson S, Evans A, Evetts N, Fabbri S, Fajans J, Friesen T, Fujiwara MC, Grandemange P, Granum P, Hangst JS, Hayden ME, Hodgkinson D, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Momose T, Mullan P, Olchanski K, Olin A, Peszka J, Powell A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production. Nat Commun 2021; 12:6139. [PMID: 34686658 PMCID: PMC8536749 DOI: 10.1038/s41467-021-26086-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/13/2021] [Indexed: 11/25/2022] Open
Abstract
The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.
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Affiliation(s)
- C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Cridland Mathad
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - S Fabbri
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - P Grandemange
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - P Granum
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691, Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - J T K McKenna
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, ON, M3J 1P3, Canada
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - P Mullan
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - J Peszka
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Powell
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, 1211, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - E Sarid
- Soreq NRC, 81800, Yavne, Israel
- Department of Physics, Ben Gurion University, 8410501, Beer Sheva, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881, Milwaukee, WI, 53201-1881, USA
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
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9
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Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Christensen A, Collister R, Mathad AC, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Grandemange P, Granum P, Hangst JS, Hardy WN, Hayden ME, Hodgkinson D, Hunter E, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Mullan PS, Munich JJ, Olchanski K, Olin A, Peszka J, Powell A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Starko DM, So C, Stutter G, Tharp TD, Thibeault A, Thompson RI, van der Werf DP, Wurtele JS. Laser cooling of antihydrogen atoms. Nature 2021; 592:35-42. [PMID: 33790445 PMCID: PMC8012212 DOI: 10.1038/s41586-021-03289-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 01/26/2021] [Indexed: 11/08/2022]
Abstract
The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6-8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11-13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.
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Affiliation(s)
- C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Christensen
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | | | - A Cridland Mathad
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - P Grandemange
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - P Granum
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - E Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physics, British Columbia Institute of Technology, Burnaby, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J T K McKenna
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - J M Michan
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - T Momose
- TRIUMF, Vancouver, British Columbia, Canada.
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
| | - P S Mullan
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - A Olin
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - J Peszka
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Powell
- Department of Physics, College of Science, Swansea University, Swansea, UK
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - E Sarid
- Soreq NRC, Yavne, Israel
- Department of Physics, Ben Gurion University, Beer Sheva, Israel
| | - D M Silveira
- TRIUMF, Vancouver, British Columbia, Canada
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - D M Starko
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - C So
- TRIUMF, Vancouver, British Columbia, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - A Thibeault
- TRIUMF, Vancouver, British Columbia, Canada
- Faculté de Génie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
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10
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Granum P, Hangst JS, Hardy WN, Hayden ME, Hunter ED, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, So C, Starko DM, Stutter G, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Investigation of the fine structure of antihydrogen. Nature 2020; 578:375-380. [PMID: 32076225 PMCID: PMC7162817 DOI: 10.1038/s41586-020-2006-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/20/2019] [Indexed: 10/29/2022]
Abstract
At the historic Shelter Island Conference on the Foundations of Quantum Mechanics in 1947, Willis Lamb reported an unexpected feature in the fine structure of atomic hydrogen: a separation of the 2S1/2 and 2P1/2 states1. The observation of this separation, now known as the Lamb shift, marked an important event in the evolution of modern physics, inspiring others to develop the theory of quantum electrodynamics2-5. Quantum electrodynamics also describes antimatter, but it has only recently become possible to synthesize and trap atomic antimatter to probe its structure. Mirroring the historical development of quantum atomic physics in the twentieth century, modern measurements on anti-atoms represent a unique approach for testing quantum electrodynamics and the foundational symmetries of the standard model. Here we report measurements of the fine structure in the n = 2 states of antihydrogen, the antimatter counterpart of the hydrogen atom. Using optical excitation of the 1S-2P Lyman-α transitions in antihydrogen6, we determine their frequencies in a magnetic field of 1 tesla to a precision of 16 parts per billion. Assuming the standard Zeeman and hyperfine interactions, we infer the zero-field fine-structure splitting (2P1/2-2P3/2) in antihydrogen. The resulting value is consistent with the predictions of quantum electrodynamics to a precision of 2 per cent. Using our previously measured value of the 1S-2S transition frequency6,7, we find that the classic Lamb shift in antihydrogen (2S1/2-2P1/2 splitting at zero field) is consistent with theory at a level of 11 per cent. Our observations represent an important step towards precision measurements of the fine structure and the Lamb shift in the antihydrogen spectrum as tests of the charge-parity-time symmetry8 and towards the determination of other fundamental quantities, such as the antiproton charge radius9,10, in this antimatter system.
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11
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Maxwell D, Mauldin RL, Kao D. HEALTHCARE ACCESS AND SOCIAL ENGAGEMENT OF OLDER MINORITY ADULTS: EXPERIENCES NAVIGATING TRANSPORTATION BARRIERS. Innov Aging 2019. [PMCID: PMC6846039 DOI: 10.1093/geroni/igz038.3297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Transportation is vital in the daily lives of older adults and provides access to health care services and health enhancing activities, such as social engagement. Disparities in mobility exist for older African American and Hispanic adults compared to non-Hispanic Whites, including higher likelihood of driving cessation at an earlier age and having a higher risk for reduced life space. This poster presents findings from a qualitative analysis of data from the Using Geo-Ethnography to Explore the Spatial Accessibility of Health Services for Aging Minorities Study (GeoSAS), a mixed methods study of older minority adults in Houston, TX. Using interpretive phenomenological analysis, the transcripts of semistructured interviews with 23 older adults (13 African American and 10 Hispanic; 17 female; mean age = 71.3 yrs, SD = 6.3 years) were analyzed to address the research question: What are the mobility experiences and perceptions of minority older adults regarding healthcare access and social engagement? Based on an ecological systems theoretical framework, we found reciprocal influences of (1) healthcare systems and transportation utilization and (2) participants’ health and well-being, mobility, and social engagement. Support from family members and financial capacity were critical for participants’ mobility. Implications of this research include educating health care providers about patients’ transportation experiences and barriers, optimizing social support to increase mobility, and addressing systematic disparities in transportation access to enhance health and well-being for older minority adults.
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Affiliation(s)
- December Maxwell
- The University of Texas at Arlington, Arlington, Texas, United States
| | - Rebecca L Mauldin
- The University of Texas at Arlington, Arlington, Texas, United States
| | - Dennis Kao
- Carleton University, School of Social Work, Ottawa, Ontario, Canada
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12
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Phadke R, Dean A, Evans M, Parker A, Maxwell D, Sewry C, Sarkozy A, Muntoni F. P.83Vacuolar myopathy with valosin containing protein (VCP)-positive intranuclear and cytoplasmic inclusions: report of two cases with early and late childhood-onset disease. Neuromuscul Disord 2019. [DOI: 10.1016/j.nmd.2019.06.112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Robinson SR, Maxwell D, Williams JR. Qualitative, Interpretive Metasynthesis of Women's Experiences of Intimate Partner Violence During Pregnancy. J Obstet Gynecol Neonatal Nurs 2019; 48:604-614. [PMID: 31479629 DOI: 10.1016/j.jogn.2019.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2019] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To describe the perspectives of women who experienced intimate partner violence (IPV) during pregnancy through a qualitative, interpretive metasynthesis. DATA SOURCES We searched 12 electronic databases to identify articles on qualitative studies pertaining to women's experiences of IPV during pregnancy. We searched Academic Search Complete, AgeLine, CINAHL Complete, Family Studies Abstracts, MEDLINE, PsycARTICLES, Psychology and Behavioral Sciences, PsycINFO, Social Work Abstracts, Health Source-Consumer Edition, Health Source-Nursing/Academic Edition, and Humanities Full Text for articles published from 2008 through 2018. DATA EXTRACTION We used inclusion and exclusion criteria to identify eight reports of qualitative studies that contained direct quotations in which women described their experiences of IPV. DATA SYNTHESIS We used a methodologic reduction to provide a theoretical context that helped us synthesize the data to five key themes: Pregnancy Escalates Abuse, Concern for Unborn Fetus, Importance ofSupport, My Child Saved Me, and Pregnancy Is a Catalyst for Reflection. CONCLUSION The results of our synthesis illustrate the unique perspectives of women who experienced IPV during pregnancy. Understanding these experiences can help health care providers assist pregnant women through enhanced screenings and education. Health care providers can also help women identify resources for emotional and financial support as they determine the best courses of action for themselves and their children.
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14
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Maxwell D, Robinson SR, Rogers K. "I keep it to myself": A qualitative meta-interpretive synthesis of experiences of postpartum depression among marginalised women. Health Soc Care Community 2019; 27:e23-e36. [PMID: 30178901 DOI: 10.1111/hsc.12645] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/19/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
Postpartum depression (PPD) is a significant public health concern due to the physical, emotional, economic, and life course outcomes. Rates of PPD are significantly higher for marginalised populations and can impact low-income, minority, and/or immigrant women differently when compared to white middle-class women. Commonly studied negative effects of PPD include poor health outcomes, mother-child bonding challenges, and negative child educational outcomes. However, research surveying the postpartum experience and negative outcomes among marginalised women is sparse. This study implemented a qualitative meta-interpretive synthesis (QIMS) methodology to synthesise themes across 12 qualitative research articles surveying postpartum experiences of marginalised women in North American countries. Articles included in the QIMS were extracted from online databases from a 10-year window spanning January 2008-2018. The guiding research question was "What are the PPD experiences of women belonging to marginalized populations?" Constant comparative analysis was used with coding in atlas.ti and themes were synthesised with input of all three authors. Five main themes emerged. The themes are (a) intersections of PPD and poverty, (b) culture and PPD, (c) pressures of mothering, (d) strengths and coping, and (e) abuse affects my PPD experience. Subthemes such as "I keep it to myself" relating to cultural response to PPD and idealised mothering were also discovered. Implications for social workers, nurses, and future research are discussed.
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Affiliation(s)
| | | | - Kelli Rogers
- The University of Texas at Arlington, Arlington, Texas
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15
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Stauss K, Jackson BA, Maxwell D. Developing networks in disempowered communities: Experiencing hardships while focusing on opportunities. J Community Appl Soc Psychol 2019. [DOI: 10.1002/casp.2408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | - December Maxwell
- School of Social WorkUniversity of Texas at Arlington Arlington TX
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16
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Hunter ED, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Starko DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Observation of the 1S-2P Lyman-α transition in antihydrogen. Nature 2018; 561:211-215. [PMID: 30135588 PMCID: PMC6786973 DOI: 10.1038/s41586-018-0435-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/05/2018] [Indexed: 11/09/2022]
Abstract
In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.
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Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | | | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - E D Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - J M Michan
- TRIUMF, Vancouver, British Columbia, Canada
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - A Olin
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | | | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - D M Starko
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
- IRFU, CEA/Saclay, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
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17
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Demmel F, McPhail D, French C, Maxwell D, Harrison S, Boxall J, Rhodes N, Mukhopadhyay S, Silverwood I, Sakai VG, Fernandez-Alonso F. ToF-Backscattering spectroscopy at the ISIS Facility: Status and Perspectives. ACTA ACUST UNITED AC 2018. [DOI: 10.1088/1742-6596/1021/1/012027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Scriven JE, Scobie A, Verlander NQ, Houston A, Collyns T, Cajic V, Kon OM, Mitchell T, Rahama O, Robinson A, Withama S, Wilson P, Maxwell D, Agranoff D, Davies E, Llewelyn M, Soo SS, Sahota A, Cooper MA, Hunter M, Tomlins J, Tiberi S, Kendall S, Dedicoat M, Alexander E, Fenech T, Zambon M, Lamagni T, Smith EG, Chand M. Mycobacterium chimaera infection following cardiac surgery in the United Kingdom: clinical features and outcome of the first 30 cases. Clin Microbiol Infect 2018; 24:1164-1170. [PMID: 29803845 DOI: 10.1016/j.cmi.2018.04.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/22/2018] [Accepted: 04/24/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Mycobacterium chimaera infection following cardiac surgery, due to contaminated cardiopulmonary bypass heater-cooler units, has been reported worldwide. However, the spectrum of clinical disease remains poorly understood. To address this, we report the clinical and laboratory features, treatment and outcome of the first 30 UK cases. METHODS Case note review was performed for cases identified retrospectively through outbreak investigations and prospectively through ongoing surveillance. Case definition was Mycobacterium chimaera detected in any clinical specimen, history of cardiothoracic surgery with cardiopulmonary bypass, and compatible clinical presentation. RESULTS Thirty patients were identified (28 with prosthetic material) exhibiting a spectrum of disease including prosthetic valve endocarditis (14/30), sternal wound infection (2/30), aortic graft infection (4/30) and disseminated (non-cardiac) disease (10/30). Patients presented a median of 14 months post surgery (maximum 5 years) most commonly complaining of fever and weight loss. Investigations frequently revealed lymphopenia, thrombocytopenia, liver cholestasis and non-necrotizing granulomatous inflammation. Diagnostic sensitivity for a single mycobacterial blood culture was 68% but increased if multiple samples were sent. In all, 27 patients started macrolide-based combination treatment and 14 had further surgery. To date, 18 patients have died (60%) a median of 30 months (interquartile range 20-39 months) after initial surgery. Survival analysis identified younger age, mitral valve surgery, mechanical valve replacement, higher serum sodium concentration and lower C-reactive protein as factors associated with better survival. CONCLUSIONS Mycobacterium chimaera infection following cardiac surgery is associated with a wide spectrum of disease. The diagnosis should be considered in all patients who develop an unexplained illness following cardiac surgery.
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Affiliation(s)
- J E Scriven
- Department of Infection and Tropical Medicine, Birmingham Heartlands Hospital, Birmingham, UK; National Infection Service, Public Health England, Colindale, London, UK.
| | - A Scobie
- National Infection Service, Public Health England, Colindale, London, UK
| | - N Q Verlander
- Statistics Unit, National Infection Service, Public Health England, Colindale, London, UK
| | - A Houston
- Department of Infection, St Georges Universities NHS Foundation Trust, London, UK
| | - T Collyns
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - V Cajic
- Department of Infection, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - O M Kon
- Department of Respiratory Medicine, Imperial College Healthcare NHS Trust, London, UK
| | - T Mitchell
- Department of Infection and Tropical Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - O Rahama
- Hull and East Yorkshire Hospitals NHS Trust, Hull, UK
| | - A Robinson
- Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - S Withama
- Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - P Wilson
- University College London Hospitals NHS Foundation Trust, London, UK
| | - D Maxwell
- Department of Respiratory Medicine, East Sussex Healthcare NHS Trust, Eastbourne, UK
| | - D Agranoff
- Department of Microbiology and Infection, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - E Davies
- Public Health Wales Microbiology, Cardiff, UK
| | - M Llewelyn
- Department of Infectious Diseases, Royal Gwent Hospital, Newport, UK
| | - S-S Soo
- Department of Microbiology, Nottingham University Hospitals NHS Trust, QMC Campus, Nottingham, UK
| | - A Sahota
- Department of Infection and Tropical Medicine, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - M A Cooper
- Department of Microbiology, The Royal Wolverhampton Hospitals NHS Trust, Wolverhampton, UK
| | - M Hunter
- Department of Infectious Diseases, Royal Victoria Hospital, Belfast, UK
| | - J Tomlins
- Department of Infection, St Georges Universities NHS Foundation Trust, London, UK
| | - S Tiberi
- Division of Infection, Barts Health NHS Trust, Royal London Hospital, London, UK; Blizard Institute, Barts and the London School of Medicine and Dentistry, London, UK
| | - S Kendall
- Society for Cardiothoracic Surgery in Great Britain and Ireland, London, UK; South Tees Hospitals Foundation NHS Trust, Middlesbrough, UK
| | - M Dedicoat
- Department of Infection and Tropical Medicine, Birmingham Heartlands Hospital, Birmingham, UK
| | - E Alexander
- National Infection Service, Public Health England, Colindale, London, UK
| | | | - M Zambon
- National Infection Service, Public Health England, Colindale, London, UK
| | - T Lamagni
- National Infection Service, Public Health England, Colindale, London, UK
| | - E G Smith
- National Infection Service, Public Health England, Colindale, London, UK
| | - M Chand
- National Infection Service, Public Health England, Colindale, London, UK; National Institute for Health Research Health Protection Research Unit in Respiratory Infections, Imperial College London, London, UK; Guy's and St Thomas' NHS Foundation Trust, London, UK
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19
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Characterization of the 1S-2S transition in antihydrogen. Nature 2018; 557:71-75. [PMID: 29618820 PMCID: PMC6784861 DOI: 10.1038/s41586-018-0017-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/06/2018] [Indexed: 11/09/2022]
Abstract
In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.
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Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea, UK
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | | | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
- IRFU, CEA/Saclay, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
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20
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Erratum: Observation of the hyperfine spectrum of antihydrogen. Nature 2018; 553:530. [PMID: 29258296 DOI: 10.1038/nature24663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This corrects the article DOI: 10.1038/nature23446.
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21
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, So C, Stutter G, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Enhanced Control and Reproducibility of Non-Neutral Plasmas. Phys Rev Lett 2018; 120:025001. [PMID: 29376718 DOI: 10.1103/physrevlett.120.025001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Indexed: 06/07/2023]
Abstract
The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.
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Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, United Kingdom
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - C L Cesar
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - T Momose
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - R L Sacramento
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - E Sarid
- Soreq NRC, Yavne 81800, Israel
| | - D M Silveira
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - C So
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881,Milwaukee, Wisconsin 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - R I Thompson
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
- IRFU, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
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22
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Thomas J, Collier-Tenison S, Maxwell D, Cheek C. TANF Participation and Intimate Partner Violence: Exploring Barriers to Self-Sufficiency. ACTA ACUST UNITED AC 2017. [DOI: 10.11114/ijsss.v5i12.2749] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Interpersonal Violence (IPV) is regarded as a primary barrier to employment for women in poverty. For recipients of Temporary Assistance to Needy Families (TANF), required to participate in work-related activities, experiences of IPV threatens the ability to meet work requirements, resulting in sanctions, if they do not have exemptions through a domestic violence option (DVO) waiver. The purpose of the current study was to assess the effects of IPV on self-sufficiency in a sample of TANF participants. Data for the study were collected from a mail survey instrument sent to 2,000 randomly selected TANF recipients in one state in the U.S. Findings indicate the majority of the sample (N=525) was female (96%), non-white (73%), and single (86%). One-third of respondents experienced IPV and 29% experienced IPV within the past year. Approximately half of the respondents sustained a physical injury and 29% reported trouble working due to IPV. Non-parametric correlation analysis indicated those who reported IPV were less likely to be employed (p <.002). Respondents reporting violence in the past year and were less likely to be self-sufficient (p =.01). Lastly, participants who experienced an injury from IPV were also significantly more likely to have trouble working (p <.001). Although IPV is just one of many barriers to self-sufficiency for poor women, the lack of access to employment can have dire consequences for women reliant upon TANF benefits. This study indicates a need to further explore the linkages between IPV, access to employment, and other barriers to self-sufficiency.
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23
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Observation of the hyperfine spectrum of antihydrogen. Nature 2017; 548:66-69. [PMID: 28770838 DOI: 10.1038/nature23446] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 06/30/2017] [Indexed: 11/09/2022]
Abstract
The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 1013 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 104. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.
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Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, UK
| | - E Butler
- Physics Department, CERN, CH-1211 Geneve 23, Switzerland
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Gutierrez
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.,Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, UK
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - A Ishida
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, UK
| | - S A Jones
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - J M Michan
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne CH-1015, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - P Nolan
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - E Sarid
- Soreq NRC, Yavne 81800, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - S Stracka
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Universita di Pisa and Sezione INFN di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - T D Tharp
- Physics Department, Marquette University, PO Box 1881, Milwaukee, Wisconsin 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK.,IRFU, CEA/Saclay, F-91191, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
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24
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Antihydrogen accumulation for fundamental symmetry tests. Nat Commun 2017; 8:681. [PMID: 28947794 PMCID: PMC5613003 DOI: 10.1038/s41467-017-00760-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/20/2017] [Indexed: 11/18/2022] Open
Abstract
Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles. Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.
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Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - E Butler
- Physics Department, CERN, CH-1211, Geneve 23, Switzerland
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark.
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - A Gutierrez
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, BC, Canada, V5A 1S6
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Ishida
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033, Japan
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - S A Jones
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691, Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - J M Michan
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3.,École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015, Lausanne, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, BC, Canada, V5A 1S6
| | - P Nolan
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3.,Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada, V8P 5C2
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - E Sarid
- Soreq NRC, Yavne, 81800, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - S Stracka
- Universita di Pisa and Sezione INFN di Pisa, Largo Pontecorvo 3, 56127, Pisa, Italy
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881, Milwaukee, WI, 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.,IRFU, CEA/Saclay, F-91191, Gif-sur-Yvette, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
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25
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Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Observation of the 1S–2S transition in trapped antihydrogen. Nature 2016; 541:506-510. [DOI: 10.1038/nature21040] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 11/09/2022]
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26
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Mead L, Porteous L, Tait M, Stoker R, Payne S, Calvert C, Maxwell D, Katikireddi SV. The prevalence of medical reasons for non-participation in the Scottish breast and bowel cancer screening programmes. J Med Screen 2015; 22:106-8. [PMID: 25753487 PMCID: PMC4429165 DOI: 10.1177/0969141315572173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 01/20/2015] [Indexed: 11/19/2022]
Abstract
Objective Increasing uptake of cancer screening is a priority for health systems internationally, however, some patients may not attend because they are undergoing active treatment for the cancer of interest or have other medical reasons that mean participation would be inappropriate. This study aims to quantify the proportion of non-participants who have a medical reason for not attending cancer screening. Methods Medical reasons for not participating in breast and bowel screening were defined a priori on the basis of a literature review and expert opinion. The notes of 700 patients at two GP practices in Scotland were reviewed, to ascertain the prevalence of medical reasons amongst non-participants. Simple proportions and confidence intervals were calculated. Results 17.4% of breast and 2.3% of bowel screening non-participants had a medical reason to not participate. The two most common reasons were previous breast cancer follow up (8.86%) and recent mammogram (6.57%). Conclusion These patients may not benefit from screening while also being distressed by receiving an invitation. This issue also makes accurate monitoring and target-setting for improving uptake difficult. Further work is needed to estimate robustly the extent to which medical reasons account for screening non-participation in a larger population.
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Affiliation(s)
- L Mead
- College of Medicine, 47 Little France Crescent, Edinburgh, Midlothian EH16 4TJ
| | - L Porteous
- North Berwick Health Centre, 54 St Baldred's Road, North Berwick, East Lothian EH39 4PU
| | - M Tait
- South East Scotland Breast Screening Programme, Ardmillan House, Ardmillan Terrace, Edinburgh EH11 2JL
| | - R Stoker
- NHS Lothian, Waverley Gate, 2-4 Waterloo Place, Edinburgh, Midlothian EH1 3EG
| | - S Payne
- Department of Public Health and Health Policy, NHS Lothian, Waverley Gate, 2-4 Waterloo Place, Edinburgh, Midlothian EH1 3EG
| | - C Calvert
- Bruntsfield Medical Practice, 11 Forbes Road, Edinburgh EH10 4EY
| | - D Maxwell
- Howden Health Centre, Howden road West, Livingston
| | - S V Katikireddi
- MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Top floor, 200 Renfield Street, Glasgow, G2 3QB
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27
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Demmel F, McPhail D, Crawford J, Maxwell D, Pokhilchuk K, Garcia-Sakai V, Mukhopadyay S, Telling M, Bermejo F, Skipper N, Fernandez-Alonso F. Opening the terahertz window on the OSIRIS spectrometer. EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158303003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Hicks A, Muthukumarasamy S, Maxwell D, Howlett D. Chronic inactive pulmonary tuberculosis and treatment sequelae: chest radiographic features. Int J Tuberc Lung Dis 2014; 18:128-33. [PMID: 24429302 DOI: 10.5588/ijtld.13.0360] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The chest radiograph (CXR) is a key initial tool in the diagnosis of many lung conditions, including pulmonary tuberculosis (TB). With proper use of anti-tuberculosis drugs, TB can be treated effectively and many CXR changes are limited. However, anti-tuberculosis drugs have not always been available, and in some cases they have not been started early in the disease process. The infection has then been able to take hold and cause significant radiologically visible damage, such as calcification and fibrosis. Before the use of anti-tuberculosis drugs, a variety of surgical techniques were employed to control pulmonary infection, including plombage, oleothorax, phrenic nerve crush and thoracoplasty. Each of these led to distinctive CXR features. This article sets out to describe the CXR features of chronic disease and surgical treatments, as their increasing rarity with the passage of time has meant that they can be misinterpreted. However, with increasing life expectancy and the revival of surgery due to the development of anti-tuberculosis drug resistance, the correct interpretation of these CXR changes is still of importance.
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Affiliation(s)
- A Hicks
- Department of Respiratory Medicine and Allergy, Kings College London, London, UK
| | - S Muthukumarasamy
- Department of Radiology, Eastbourne District General Hospital, Eastbourne, UK
| | - D Maxwell
- Department of Respiratory Medicine, Eastbourne District General Hospital, Eastbourne, UK
| | - D Howlett
- Department of Radiology, Eastbourne District General Hospital, Eastbourne, UK
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29
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Kusminsky RE, Witsberger T, Todd Kuenstner J, Willis Trammell S, Schlarb CA, Maxwell D, Richmond BK, Boland JP. Identification of the sentinel node by ultrasonography in patients with breast cancer. Ann Surg Oncol 2014; 21:1969-74. [PMID: 24566860 DOI: 10.1245/s10434-014-3570-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Identification of the sentinel node (SN) in patients with breast cancer is done by tracking a radioactive tracer, a vital dye, or both, as the marker(s) reach the axilla. Replacing this method with ultrasonographic (US) recognition of the SN could eventually spare patients the need for systemic anesthesia, permit minimally invasive outpatient biopsy of the node, and allow the formulation of a precise therapeutic plan before a definitive surgical procedure. METHODS Eighty-eight axillae of 84 patients with a histologic diagnosis of breast cancer were studied by injecting the subareolar area of the affected breast(s) with technetium 99 and an iron preparation before the planned surgical procedure and SN biopsy. An axillary US scan was performed in all patients before the injection of the markers. After induction of anesthesia, the SN was identified, needle-localized, and extracted under US guidance. Confirmation that the SN was retrieved was established by concordance with the audible gamma signal, unless there was none. All extracted nodes had iron stains performed. RESULTS All except three of the SNs were identified with US after the iron marker was injected, and all except six were identified by their radioactive signal. One of the SNs undetected on US was identified by its radioactive tracer, and the other two, although seen on US, had neither a gamma signal nor concordant iron deposits. All other SNs identified with US had a concordant audible signal when there was one, and all had concordant iron deposits on microscopy. Of the six SNs without a gamma signal, three without preincision activity were identified with US; three with neither a preincision nor an ex vivo signal were seen with US, but two of these were the SNs without a concordant iron deposit. CONCLUSIONS Using an iron preparation, the SN in patients with breast cancer can be identified with US with an accuracy equal to and perhaps better than that achieved with a radioactive tracer. These findings may change the current diagnostic model and affect the therapeutic algorithm of breast cancer patients.
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Affiliation(s)
- Roberto E Kusminsky
- Department of Surgery, West Virginia University/Charleston Division, Charleston, WV, USA,
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30
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Maxwell D, Szwer DJ, Paredes-Barato D, Busche H, Pritchard JD, Gauguet A, Weatherill KJ, Jones MPA, Adams CS. Storage and control of optical photons using Rydberg polaritons. Phys Rev Lett 2013; 110:103001. [PMID: 23521254 DOI: 10.1103/physrevlett.110.103001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 06/01/2023]
Abstract
We use a microwave field to control the quantum state of optical photons stored in a cold atomic cloud. The photons are stored in highly excited collective states (Rydberg polaritons) enabling both fast qubit rotations and control of photon-photon interactions. Through the collective read-out of these pseudospin rotations it is shown that the microwave field modifies the long-range interactions between polaritons. This technique provides a powerful interface between the microwave and optical domains, with applications in quantum simulations of spin liquids, quantum metrology and quantum networks.
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Affiliation(s)
- D Maxwell
- Joint Quantum Centre Durham-Newcastle, Department of Physics, Durham University, Rochester Building, South Road, Durham DH1 3LE, United Kingdom.
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31
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Sherry N, Qin J, Fuller MS, Xie Y, Mola O, Bauer M, McIntyre NS, Maxwell D, Liu D, Matias E, Armstrong C. Remote Internet access to advanced analytical facilities: a new approach with Web-based services. Anal Chem 2012; 84:7283-91. [PMID: 22894172 DOI: 10.1021/ac301513b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Over the past decade, the increasing availability of the World Wide Web has held out the possibility that the efficiency of scientific measurements could be enhanced in cases where experiments were being conducted at distant facilities. Examples of early successes have included X-ray diffraction (XRD) experimental measurements of protein crystal structures at synchrotrons and access to scanning electron microscopy (SEM) and NMR facilities by users from institutions that do not possess such advanced capabilities. Experimental control, visual contact, and receipt of results has used some form of X forwarding and/or VNC (virtual network computing) software that transfers the screen image of a server at the experimental site to that of the users' home site. A more recent development is a web services platform called Science Studio that provides teams of scientists with secure links to experiments at one or more advanced research facilities. The software provides a widely distributed team with a set of controls and screens to operate, observe, and record essential parts of the experiment. As well, Science Studio provides high speed network access to computing resources to process the large data sets that are often involved in complex experiments. The simple web browser and the rapid transfer of experimental data to a processing site allow efficient use of the facility and assist decision making during the acquisition of the experimental results. The software provides users with a comprehensive overview and record of all parts of the experimental process. A prototype network is described involving X-ray beamlines at two different synchrotrons and an SEM facility. An online parallel processing facility has been developed that analyzes the data in near-real time using stream processing. Science Studio and can be expanded to include many other analytical applications, providing teams of users with rapid access to processed results along with the means for detailed discussion of their significance.
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Affiliation(s)
- N Sherry
- Faculty of Science, The University of Western Ontario, London, ON, Canada
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32
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Pritchard JD, Maxwell D, Gauguet A, Weatherill KJ, Jones MPA, Adams CS. Cooperative atom-light interaction in a blockaded Rydberg ensemble. Phys Rev Lett 2010; 105:193603. [PMID: 21231168 DOI: 10.1103/physrevlett.105.193603] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Indexed: 05/30/2023]
Abstract
By coupling a probe transition to a Rydberg state using electromagnetically induced transparency (EIT) we map the strong dipole-dipole interactions onto an optical field. We characterize the resulting cooperative optical nonlinearity as a function of probe strength and density. We demonstrate good quantitative agreement between the experiment and an N-atom cooperative model for N=3 atoms per blockade sphere and the n=60 Rydberg state. The measured linewidth of the EIT resonance places an upper limit on the dephasing rate of the blockade spheres of <110 kHz.
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Affiliation(s)
- J D Pritchard
- Department of Physics, Durham University, Rochester Building, South Road, Durham DH1 3LE, United Kingdom.
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34
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Simpson JM, Maxwell D, Rosenthal E, Gill H. Fetal ventricular tachycardia secondary to long QT syndrome treated with maternal intravenous magnesium: case report and review of the literature. Ultrasound Obstet Gynecol 2009; 34:475-480. [PMID: 19731233 DOI: 10.1002/uog.6433] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ventricular tachycardia is a very rare fetal arrhythmia accounting for fewer than 2% of fetal tachycardias. We describe a fetus presenting at 30 weeks' gestation with ventricular tachycardia at a rate of 220 beats per min and fetal hydrops. The tachycardia was unresponsive to flecainide but was controlled within 12 h by an intravenous infusion of magnesium to the mother. Despite rapid control of the arrhythmia the fetus developed severe periventricular leukomalacia before birth for which a poor neurological prognosis was given. The baby was delivered preterm at 32 weeks' gestation and died on the sixth day after birth. Long QT syndrome was identified postnatally on the electrocardiogram, and was confirmed by genetic testing which showed a mutation in the KCNH2 gene (p.T613M).
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Affiliation(s)
- J M Simpson
- Department of Congenital Heart Disease, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK.
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35
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Affiliation(s)
- V Valayatham
- Guy's and St Thomas NHS Trust, Lambeth Palace Road, London, UK
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Maxwell D, Lilford R, Morsman J, Rodeck C, Old J, Thein S. Direct DNA analysis for diagnosing fetal sickle status in first trimester chorion tissue. J OBSTET GYNAECOL 2009. [DOI: 10.3109/01443618509067730] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Volgin A, LeRoux L, Maxwell D, Schellingerhout D, Thitai-Kumar A, He Y, Gelovani J, Schwartz D. In Vitro 3D Modeling of Host Organ-specific Whole Tumor Responses to Radiation. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Sau A, Weber M, Shennan AH, Maxwell D. Antenatal detection of arteriovenous anastomoses in monochorionic twin pregnancy. Int J Gynaecol Obstet 2007; 100:56-9. [PMID: 17920601 DOI: 10.1016/j.ijgo.2007.06.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 06/15/2007] [Accepted: 06/21/2007] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To revalidate the detection technique for arteriovenous anastomoses in an unselected group of monochorionic twins, and to make recommendations about its applicability for more widespread use. METHODS Women with monochorionic diamniotic (MCDA) twins were recruited and underwent placental mapping by color Doppler ultrasound. Images of placental maps showing the location and type of anastomoses were saved as digital video clips. After delivery, dye injection study of all the placentas was performed to delineate the site and type of anastomoses. A digital photograph of each injection study was taken and saved. The antenatal ultrasound images and postnatal dye injection studies were compared. RESULTS 18 sets MCDA twins were evaluated. In 3 cases there was evidence of twin-to-twin transfusion syndrome. Dye injection of 18 placentas revealed 21 arterio-arterial anastomoses (AAA), 21 arteriovenous anastomoses (AVA) and 4 veno-venous anastomoses (VVA). Of these, 10 (48%) AAAs and 5 (24%) AVAs were detected antenatally by color Doppler. In all cases, where an AVA was detected, the placenta was located anteriorly. CONCLUSION Antenatal detection of AVA was feasible when the placenta was located anteriorly, but proved difficult in posteriorly situated placentas.
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Affiliation(s)
- A Sau
- Department of Obstetrics and Gynaecology, University Hospital Lewisham, London, UK.
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39
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Ash A, Smith A, Maxwell D. Authors response to: Caesarean scar pregnancy. BJOG 2007. [DOI: 10.1111/j.1471-0528.2007.01437.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Hu YF, Zuin L, Wright G, Igarashi R, McKibben M, Wilson T, Chen SY, Johnson T, Maxwell D, Yates BW, Sham TK, Reininger R. Commissioning and performance of the variable line spacing plane grating monochromator beamline at the Canadian Light Source. Rev Sci Instrum 2007; 78:083109. [PMID: 17764315 DOI: 10.1063/1.2778613] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The variable line spacing plane grating monochromator beamline at the Canadian Light Source (CLS) employs three grazing incidence variable line spacing gratings to cover a photon energy range of 5-250 eV. It uses a 185 mm period length planar permanent magnet insertion device as the photon source, sharing a straight section with another soft x-ray beamline at the CLS. The commissioning and performance of the beamline is reported. The high resolution photoabsorption spectra of Ar and PF(5) gases are reported. A resolving power of over 40,000 for photons in the low energy region and >10,000 for a wider energy range (8-200 eV) can be achieved. A photon flux of up to 2 x 10(12) photons/s per 100 mA with slit settings of 50 microm has been measured.
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Affiliation(s)
- Y F Hu
- Canadian Light Source, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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41
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Faderl S, Bornmann W, Maxwell D, Peng Z, Van Q, Liu Z, Verstovsek S, Ferrajoli A, Kantarjian HM, Estrov Z. Molecular targeting in acute myeloid leukemia (AML) therapy: APcK110 is a new inhibitor of c-Kit activity in AML blasts. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.7019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
7019 Background: Tyrosine kinases (TK) are important for most cellular functions and require stringent control and regulation. C- Kit, a TK and transmembrane receptor for stem cell factor, plays a crucial role in hematopoiesis. Mutations of c-Kit can contribute to AML pathophysiology and have been associated with shorter survival and higher relapse risk following standard AML therapy. On the other hand, responses have been observed following TK inhibitor therapy such as imatinib. Identification of c-Kit or its pathways in AML leukemogenesis and development of new compounds targeting these mutations may therefore hold promise for therapy. Methods: APcK110 is the result of a structure-based design of c-Kit inhibitors and was derived of a set of compounds with favorable IC50 values in a c-Kit kinase assay. Here we present results of the activity and mechanism of action of APcK110. We used the mastocytosis cell line HMC1.1 carrying an activating c-Kit mutation and two AML lines (OCIM2 and OCI/AML3) as well as primary samples from patients with AML. Results: We demonstrate that: (1) APcK110 inhibits proliferation of all three cell lines in a dose dependent fashion using an MTT assay. Inhibition of proliferation is most significant in the SCF-dependent cell line OCI/AML3; (2) inhibition of OCIM2 cells (SCF-responsive) by APcK110 can be enhanced when adding SCF suggesting recruitment of c-Kit-dependent signaling components and increased activity of the c-Kit inhibitor under these circumstances; (3) APcK110 is a more potent inhibitor of OCI/AML3 proliferation than imatinib and dasatininb; (4) using Western immunoblotting, APcK110 decreases levels of phospho-Akt, phospho-Stat3 and 5 in a time- and dose-dependent fashion demonstrating activity of APcK110 on c-Kit downstream signaling pathways; (5) APcK110 induces apoptosis by cleavage of caspase 3 and PARP; (6) APcK110 inhibits proliferation of primary AML cells in a clonogenic assay, but does not affect proliferation of normal controls. Conclusions: APcK110 is a potent inhibitor of AML cell lines and primary samples from patients with AML. Activation of c-Kit or downstream pathways increases activity of APcK110. APcK110 and similar compounds should be evaluated in clinical trials of patients with AML. No significant financial relationships to disclose.
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Affiliation(s)
| | | | | | - Z. Peng
- MD Anderson Cancer Ctr, Houston, TX
| | - Q. Van
- MD Anderson Cancer Ctr, Houston, TX
| | - Z. Liu
- MD Anderson Cancer Ctr, Houston, TX
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Abstract
Caesarean scar pregnancy is one of the rarest forms of ectopic pregnancy. Little is known about its incidence and natural history. With increasing incidence of caesarean section worldwide, more and more cases are diagnosed and reported. Transvaginal ultrasound and colour flow Doppler provides a high diagnostic accuracy with very few false positives. A delay in diagnosis and/or treatment can lead to uterine rupture, major haemorrhage, hysterectomy and serious maternal morbidity. Early diagnosis can offer treatment options of avoiding uterine rupture and haemorrhage, thus preserving the uterus and future fertility. Management plan should be individually tailored. Available data suggest that termination of pregnancy is the treatment of choice in the first trimester soon after the diagnosis. Expectant treatment has a poor prognosis because of risk of rupture. There are no reliable scientific data on the risk of recurrence of the condition in future pregnancy, role of the interval between the previous caesarean delivery and occurrence of caesarean scar pregnancy, and effect of caesarean wound closure technique on caesarean scar pregnancy. In this article, we aim to find the demography, pathophysiology, clinical presentation, most appropriate methods of diagnosis and management, with their implications in clinical practice for this condition.
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Affiliation(s)
- A Ash
- Guy's and St Thomas' NHS Foundation Trust, London, UK.
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Pal A, Glekas A, Doubrovin M, Balatoni J, Namavari M, Beresten T, Maxwell D, Soghomonyan S, Shavrin A, Ageyeva L, Finn R, Larson SM, Bornmann W, Gelovani JG. Molecular imaging of EGFR kinase activity in tumors with 124I-labeled small molecular tracer and positron emission tomography. Mol Imaging Biol 2007; 8:262-77. [PMID: 16897320 DOI: 10.1007/s11307-006-0049-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Positron emission tomography (PET) with epidermal growth factor receptor (EGFR) kinase-specific radiolabeled tracers could provide the means for noninvasive and repetitive imaging of heterogeneity of EGFR expression and signaling activity in tumors in individual patients before and during therapy with EGFR signaling inhibitors. We developed the synthesis and (124)I-radiolabeling of the (E)-But-2-enedioic acid [4-(3-[(124)I]iodoanilino)-quinazolin-6-yl]-amide-(3-morpholin-4-yl-propyl)-amide (morpholino-[(124)I]-IPQA), which selectively, irreversibly, and covalently binds the adenosine-triphosphate-binding site to the activated (phosphorylated) EGFR kinase, but not to the inactive EGFR kinase. The latter was demonstrated using in silico modeling with crystal structures of the wild type and different gain-of-function mutants of EGFR kinases. Also, this was demonstrated by selective radiolabeling of the EGFR kinase domain with morpholino-[(131)I]-IPQA in A431 human epidermoid carcinoma cells and Western blot autoradiography. In vitro radiotracer accumulation and washout studies demonstrated a rapid accumulation and progressive retention postwashout of morpholino-[(131)I]-IPQA in A431 epidermoid carcinoma and in U87 human glioma cells genetically modified to express the EGFRvIII mutant receptor, but not in the wild-type U87MG glioma cells under serum-starved conditions. Using morpholino-[(124)I]-IPQA, we obtained noninvasive PET images of EGFR activity in A431 subcutaneous tumor xenografts, but not in subcutaneous tumor xenografts grown from K562 human chronic myeloid leukemia cells in immunocompromised rats and mice. Based on these observations, we suggest that PET imaging with morpholino-[(124)I]-IPQA should allow for identification of tumors with high EGFR kinase signaling activity, including brain tumors expressing EGFRvIII mutants and nonsmall-cell lung cancer expressing gain-of-function EGFR kinase mutants. Because of significant hepatobiliary clearance and intestinal reuptake of the morpholino-[(124)I]-IPQA, additional [(124)I]-IPQA derivatives with improved water solubility may be required to optimize the pharmacokinetics of this class of molecular imaging agents.
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Affiliation(s)
- A Pal
- Department of Experimental Diagnostic Imaging, MD Anderson Cancer Center, Unit 057, 1515 Holcombe Blvd., Houston, TX 77030, USA
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Pal A, Glekas A, Doubrovin M, Balatoni J, Namavari M, Beresten T, Maxwell D, Soghomonyan S, Shavrin A, Ageyeva L, Finn R, Larson SM, Bornmann W, Gelovani JG. Molecular Imaging of EGFR Kinase Activity in Tumors with 124I-Labeled Small Molecular Tracer and Positron Emission Tomography. Mol Imaging Biol 2006. [DOI: 10.1007/s11307-006-0067-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The outcomes of 60 sets of monochorionic diamniotic (MCDA) twins were compared with 218 sets of dichorionic diamniotic (DCDA) twins. The caesarean section rates for MCDA were similar to those for DCDA twins (56.6 versus 53.6%, P > 0.1). Although the number of babies with 5-minute Apgar score of <7 was significantly higher for vaginally delivered MCDA twins compared with that of DCDA twins (12 versus 3.5%, P < 0.001), the umbilical artery pH of <7.2 was similar (20 versus 13%, P > 0.05). Admission to neonatal intensive care unit (NICU) and neonatal mortality were also similar in both groups. Delivery by caesarean section was associated with increased admission to the NICU and neonatal mortality for MCDA twins when compared with vaginal delivery group. From this retrospective cohort study, we can conclude that vaginal delivery for MCDA twins appeared to be a reasonable management option when similar selection criteria for vaginal delivery of DCDA twins were applied.
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Affiliation(s)
- A Sau
- Department of Obstetrics & Gynaecology, University Hospital Lewisham, London, UK.
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Gazayerli M, Bleibel W, Elhorr A, Maxwell D, Seifeldin R. A correlation between the shape of the epiglottis and obstructive sleep apnea. Surg Endosc 2006; 20:836-7. [PMID: 16544072 DOI: 10.1007/s00464-005-0641-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 09/15/2005] [Indexed: 02/04/2023]
Abstract
The incidence of Obstructive Sleep Apnea (OSA) is increasing with the rise in the prevalence of obesity in the population. Upon performing esophagogastroduodenoscopy (EGD) on more than 50 patients with BMI ranging from 21 to 63, we noticed an increase in the concavity of the posterior surface of the epiglottis in correlation with the increase in BMI. Since OSA is caused by collapse of the airways, this same pressure seems to be responsible for the deformity of the epiglottis, which normally has a minimally concave posterior surface. Therefore the shape of the epiglottis reflects the degree of airway collapse and thus the severity of OSA. We recommend that patients with increased concavity of the posterior epiglottal surface seen endoscopically should be tested for OSA.
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Abstract
An unhurried, deft, economical technique allied to efficient use of available resources, surgical instruments and support staff is the hallmark of a 'good' surgeon. To achieve this sense of fluency, surgeons need to be familiar with the tools of their profession so that these can be employed appropriately for the task at hand. The range of instruments available in obstetrics and gynaecology is no less wide or complex than in any other branch of surgery, but formal teaching in the full range of surgical hardware is frequently lacking and an individual's exposure is generally limited to the instruments used in his or her own training hospital. This chapter sets out to describe key technical areas with which surgeons need to be familiar.
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Affiliation(s)
- S Singh
- Royal Bournemouth Hospital, Castle Lane East, Bournemouth BH7 7DW, UK.
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Taylor BW, Maxwell D, Al-Hertani W. The emergency department as an asthma surveillance tool at the community level: a decline in the burden of pediatric asthma in halifax, Canada. J Asthma 2005; 42:679-82. [PMID: 16266960 DOI: 10.1080/02770900500265090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We report pediatric emergency department (PED) asthma visit and inpatient asthma (AS) admission data in our area over a 5-year period. AS visits decreased by 33.9%, AS admissions by 24.6%, both significant compared with the decline in elementary school enrollment. The decrease in asthma visits was due to a decrease in the number of asthmatic patients, not a decline in repeat visits, or use of alternate venues of care. Explanations include a decrease in the burden of disease or an improvement in ambulatory care, but not alternate treatment venues or improvement in acute (PED) care. Readily available, emergency department data are useful in the community surveillance of asthma.
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Affiliation(s)
- B W Taylor
- Departments of Emergency Medicine/Pediatrics/Family Medicine, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
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Snoek GJ, IJzerman MJ, Hermens HJ, Maxwell D, Biering-Sorensen F. Survey of the needs of patients with spinal cord injury: impact and priority for improvement in hand function in tetraplegics. Spinal Cord 2004; 42:526-32. [PMID: 15224087 DOI: 10.1038/sj.sc.3101638] [Citation(s) in RCA: 298] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To investigate the impact of upper extremity deficit in subjects with tetraplegia. SETTING The United Kingdom and The Netherlands. STUDY DESIGN Survey among the members of the Dutch and UK Spinal Cord Injury (SCI) Associations. MAIN OUTCOME PARAMETER: Indication of expected improvement in quality of life (QOL) on a 5-point scale in relation to improvement in hand function and seven other SCI-related impairments. RESULTS In all, 565 subjects with tetraplegia returned the questionnaire (overall response of 42%). Results in the Dutch and the UK group were comparable. A total of 77% of the tetraplegics expected an important or very important improvement in QOL if their hand function improved. This is comparable to their expectations with regard to improvement in bladder and bowel function. All other items were scored lower. CONCLUSION This is the first study in which the impact of upper extremity impairment has been assessed in a large sample of tetraplegic subjects and compared to other SCI-related impairments that have a major impact on the life of subjects with SCI. The present study indicates a high impact as well as a high priority for improvement in hand function in tetraplegics.
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Affiliation(s)
- G J Snoek
- Roessingh Rehabilitation Centre and Research Department, Enschede, The Netherlands
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