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Morgan KM, Baraban JH. Thermochemical Studies of Small Carbohydrates. J Org Chem 2024; 89:1769-1776. [PMID: 38227766 PMCID: PMC10845155 DOI: 10.1021/acs.joc.3c02465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/14/2023] [Accepted: 12/28/2023] [Indexed: 01/18/2024]
Abstract
Despite their prevalence in biomass and importance in biochemistry, there is still much to be learned about simple carbohydrates. Gas-phase calculations are reported here on two trioses and three tetroses. For aldotetroses, both the open-chain and furanose forms are considered. Enthalpies of reduction to polyols are calculated at the CBS-APNO level of theory, and comparisons to simple aldehydes and ketones are made. Heats of formation are calculated in two ways with overall good agreement. The heat of formation of glyceraldehyde obtained from modified HEAT calculations is also reported. Finally, calculated bond energies are presented, and the influence of the structure on the bond energies is discussed.
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Affiliation(s)
- Kathleen M. Morgan
- Department
of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125, United States
| | - Joshua H. Baraban
- Department
of Chemistry, Ben-Gurion University of the
Negev, Beer Sheva 841051, Israel
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Guram K, Duran EAM, Qiao EM, Deshler LN, Morgan KM, Murphy JD, Rose BS, Banegas M. Health System Practices and Perspectives of Social Risk Screening in Oncology. Int J Radiat Oncol Biol Phys 2023; 117:e22. [PMID: 37784899 DOI: 10.1016/j.ijrobp.2023.06.696] [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: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Social risks (e.g., food insecurity) are adverse social/economic conditions associated with poor health outcomes. Among patients with cancer, presence of social risks is associated with increased late-stage diagnoses, care delays, and mortality. The purpose of this project was to assess the perspectives and practices regarding social risk screening within a large NCI-designated cancer center. MATERIALS/METHODS Email invitations to complete a secure, online survey were distributed to oncology healthcare staff (e.g., oncologists, nurses, pharmacists, medical assistants, social workers, and patient navigators) at Moores Cancer Center between June 1, 2022 and July 31, 2022. The 6-item survey collected information on clinical role, current practices and perceived barriers to screening for social risks as part of routine care. Respondents were categorized as MD-trained providers versus non-MD clinical staff. Descriptive statistics were used, including Fisher's exact test to compare responses by respondent type (MD vs non-MD). All analyses were conducted using data management and decision management software. This project was approved by the UCSD Institutional Review Board. RESULTS A total of 59 respondents completed the survey, including 20 MDs (34%) and 39 non-MD staff (66%). Overall, most respondents reported asking patients about their social risks (75%) and communicating information about patients' social risks with other healthcare staff when clinically relevant (84%). MDs were significantly more likely to agree that they ask patients about social risks when clinically relevant than non-MDs (95% vs 64%, p = 0.024). MDs were also more likely to communicate, review and use social risk information than their non-MD colleagues. The most reported barriers to integrating social risk information into clinical care, overall, included insufficient time (73%), uncertainty about who is responsible (70%), and lack of knowledge about existing tools (75%) for asking patients about social risks, as well as lack of resources to address social risks (76%). Non-MDs were more likely to cite concern that patients and families will feel uncomfortable answering questions about social risks (67% vs 20% of MDs, p = 0.003) as a barrier. Only 30% of MDs and 46% of non-MDs agreed that "asking about social risks is outside of the scope of my role" was a barrier. CONCLUSION Most oncology providers and staff agree that obtaining social risk information is important for patient care. Developing clinic-based solutions that integrate social risk screening and referral workflows within the oncology setting is imperative to reduce cancer health disparities. Future efforts that leverage the use of electronic health records to conduct social risk screening and streamline referrals to community-based resources in oncology may improve cancer health equity.
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Affiliation(s)
- K Guram
- University of California, San Diego Moores Cancer Center, La Jolla, CA
| | - E A M Duran
- Center for Health Education and Research, University of California, San Diego, La Jolla, CA
| | - E M Qiao
- VA San Diego Health Care System, La Jolla, CA
| | - L N Deshler
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - K M Morgan
- UCSD Health, Department of Radiation Medicine and Applied Sciences, La Jolla, CA
| | - J D Murphy
- Department of Radiation Medicine and Applied Sciences, UC San Diego, La Jolla, CA
| | - B S Rose
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - M Banegas
- UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
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Morgan KM, Deshler LN, Nelson TJ, Sabater-Minarim D, Duran EAM, Banegas M, Anger J, Rose BS. Association of Transgender or Gender Non-Binary Identity on Disease Characteristics and Survival Outcomes in Prostate Cancer. Int J Radiat Oncol Biol Phys 2023; 117:e420-e421. [PMID: 37785384 DOI: 10.1016/j.ijrobp.2023.06.1575] [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: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) While it is becoming increasingly common for people to identify as transgender or gender-non-binary, our understanding of the influence of gender identity on disease severity of hormone-sensitive malignancies, including prostate cancer (PC) is limited. The goal of this study is to compare the aggressiveness of disease and survival outcomes between transgender or gender non-binary (TG) and cis-gender (CG) patients with PC. MATERIALS/METHODS The cohort included patients diagnosed with PC between 1999 and 2022 within the Veterans Health Administration (VHA) Database. TG patients were identified with an ICD 9 or 10 diagnosis code that occurred prior to PC diagnosis. Treatment information and baseline disease characteristics were ascertained through the VHA electronic health records. Multivariable logistic regressions were performed to estimate the association between TG status and presenting with Gleason > = 8, PSA > 20 ng/mL, and metastatic disease at diagnosis. Covariates in these models included age at diagnosis, race, ethnicity, marital status, and smoking status. Metastases were identified through natural language processing from cancer or radiology documents. Time to metastases was defined as the time from PC diagnosis to metastases, with other causes of death considered as competing risks. The association between TG identity status and metastatic disease was calculated with a Cox regression model. The difference in overall survival was assessed with the Kaplan-Meier method and log-rank test. RESULTS The final cohort was composed of 282,264 individuals, 219 (0.08%) of which were identified as TG. TG patients have similar odds of presenting with presenting with Gleason Score ≥8 (Odds Ratio (OR) 1.18, p = 0.31), PSA >20 ng/mL (OR 0.78, p = 0.59), and metastasis at diagnosis (OR 0.47, p = 0.29). There were 34,918 patients who develop metastatic disease at any time, 24 of which were TG. The 10-year cumulative incidence of metastases for TG and CG individuals was 11.5% (95% Confidence Interval (CI): 6.6-16.1%) and 13.9% (CI: 13.7-14.0%), respectively. There was no significant difference between TG status and risk of developing metastases (Hazard Ratio (HR) 0.93, p = 0.71). The 10-year overall survival for TG and CG was 73.4% (CI: 66.5-80.9%) and 65.0% (CI: 64.8-65.2%), respectively. There was no significant difference between TG status and overall survival (Hazard Ratio (HR) 0.83, p = 0.13). CONCLUSION TG individuals do not appear to have a difference in disease characteristics at diagnosis or survival compared to CG individuals. Future research should be done to determine the effect of gender affirming treatment on these outcomes. Furthermore, it is unclear if diagnosis codes are accurately identifying TG individuals.
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Affiliation(s)
- K M Morgan
- UCSD Health, Department of Radiation Medicine and Applied Sciences, La Jolla, CA; VA San Diego Health Care System, La Jolla, CA
| | - L N Deshler
- VA San Diego Health Care System, La Jolla, CA; UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - T J Nelson
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, CA
| | - D Sabater-Minarim
- UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - E A M Duran
- VA San Diego Health Care System, La Jolla, CA; UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - M Banegas
- UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - J Anger
- UCSD Department of Urology, La Jolla, CA
| | - B S Rose
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, CA
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Riviere P, Morgan KM, Deshler LN, Huang X, Marienfeld C, Coyne C, Rose BS, Murphy JD. Psychiatric or Drug Hospitalizations in Older Cancer Survivors on Long-Term Opioids. Int J Radiat Oncol Biol Phys 2023; 117:e257. [PMID: 37784989 DOI: 10.1016/j.ijrobp.2023.06.1206] [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: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Non-cancer patients prescribed chronic courses of opioids are at high risk of psychiatric or drug overdose particularly during the post-tapering period, but data are limited on this effect in cancer survivors. This study quantified emergency room visits or hospital admissions for psychiatric or drug/alcohol overdose/withdrawal (henceforth "events") in cancer survivors prescribed opioids related to their cancer diagnoses. MATERIALS/METHODS We identified 15,002 cancer survivors in SEER-Medicare diagnosed between 2010 and 2017 with bladder, breast, colon/rectal, kidney, lung, head/neck, or prostate cancer who were prescribed at least 6 months of stable opioids following their cancer diagnosis. The post-tapering interval was defined as a 3-month period following monthly oral morphine equivalent (OME) reduction of at least 15%. Outcomes were studied with logistic regression and time-dependent analysis was performed using a generalized estimating equation (GEE) using an auto-regressive correlation matrix; all reported p-values are two-sided. RESULTS The study had a median follow up of 24 months; in this time, 8,311 patients (55%) initiated a taper at some point. The mean daily OME in non-tapering patients was 33.4 mg compared to 47.4 mg in tapering patients (p < 0.001); both groups had a low rate of any prior events in the baseline period (7.5% versus 8%, respectively p = 0.686). Patients attempting a taper also tended to be younger (40.3% versus 35.2% age 66-70, p <0.001). There was no difference by race. Opioid tapering was not associated with a higher rate of events in the 3-month post-taper period (p = 0.81) when correcting for sex, primary care site, baseline event rate, comorbidity, and age. CONCLUSION Many older cancer survivors who are prescribed chronic opioids remain on high doses of opioids after completing therapy. These patients are at risk of acute psychiatric and drug-related emergencies. Unlike the general population, this risk does not appear to be exacerbated in the months following opioid tapering. Oncologists should be mindful of psychiatric and drug-related events in long-term cancer survivors prescribed chronic opioids, and these data should reassure physicians deciding whether or not to initiate an opioid taper. Future research should explore risk mitigation in these patients.
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Affiliation(s)
- P Riviere
- University of California San Diego Department of Radiation Medicine and Applied Sciences, La Jolla, CA; UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - K M Morgan
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA; UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - L N Deshler
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA; UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - X Huang
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - C Marienfeld
- University of California San Diego Department of Psychiatry, La Jolla, CA
| | - C Coyne
- University of California San Diego Department of Radiation Medicine and Applied Sciences, La Jolla, CA; University of California San Diego Department of Emergency Medicine, La Jolla, CA
| | - B S Rose
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA; Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, CA
| | - J D Murphy
- Department of Radiation Medicine and Applied Sciences, UC San Diego, La Jolla, CA; Center for Health Education and Research, University of California, San Diego, La Jolla, CA
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Duran EAM, Morgan KM, Deshler LN, Nelson TJ, Sabater-Minarim D, Guram K, Banegas M, Rose BS. Association between National Area Deprivation Index Rank on Disease Characteristics in Prostate Cancer. Int J Radiat Oncol Biol Phys 2023; 117:e380. [PMID: 37785287 DOI: 10.1016/j.ijrobp.2023.06.2490] [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: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Social determinants of health (SDH) play a large role in an individual's health; in recent years, there has been a push to examine the impact of one's neighborhood or "place." Previous studies have showed that living in a disadvantage neighborhood is associated with worth health outcomes. We hypothesize that equal access care will diminish the effects of living in a disadvantaged neighborhood. MATERIALS/METHODS We identified non-Hispanic African American (AA) and White (NHW) men diagnosed with PC between 2012 and 2015 in the Veterans Health Administration (VHA). Patient SDH was measured using census tract level 2015 Area Deprivation Index (ADI) information. The ADI is a composite measure that includes factor such as housing quality, income, health care access etc. We measured both National and State ADI rank as a continuous variable from 1 to 10 with 10 being highest deprivation. Patient information was gathered at the census tract level while ADI is assigned at the census block group. In order to get all information on the same geographic level, we averaged the ADI to its corresponding census tract. Associations between ADI and disease characteristics at diagnosis were measured using multivariable logistic regression models including age, race, and marital status as covariates. RESULTS The final cohort was composed of 25,222 men (8,384 AA and 16,838 NHW.) At the national level, there was no significant association between ADI and Gleason Score ≥8 (Odds Rations (OR) 0.99 [95% Confidence Interval (CI):0.98 - 1.00]), PSA >20 ng/mL (OR 0.99 [95% CI: 0.98 - 1.01]), and metastasis at diagnosis (OR 1.01 [CI: 0.98-1.04]). CONCLUSION Our results are consistent with our hypothesis that equal access care diminishes the impacts of living within a disadvantaged neighborhood. Future research should investigate the interaction between health care access and social and demographic factors.
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Affiliation(s)
- E A M Duran
- VA San Diego Health Care System, La Jolla, CA; Department of Radiation Medicine and Applied Sciences, UC San Diego, La Jolla, CA
| | - K M Morgan
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - L N Deshler
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
| | - T J Nelson
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, CA
| | - D Sabater-Minarim
- UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - K Guram
- University of California, San Diego Moores Cancer Center, La Jolla, CA
| | - M Banegas
- UCSD Health, Department of Radiation Medicine and Applied Science, La Jolla, CA
| | - B S Rose
- UCSD Center for Health Equity, Education, and Research, La Jolla, CA
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Okumura T, Azuma T, Bennett DA, Chiu I, Doriese WB, Durkin MS, Fowler JW, Gard JD, Hashimoto T, Hayakawa R, Hilton GC, Ichinohe Y, Indelicato P, Isobe T, Kanda S, Katsuragawa M, Kawamura N, Kino Y, Mine K, Miyake Y, Morgan KM, Ninomiya K, Noda H, O'Neil GC, Okada S, Okutsu K, Paul N, Reintsema CD, Schmidt DR, Shimomura K, Strasser P, Suda H, Swetz DS, Takahashi T, Takeda S, Takeshita S, Tampo M, Tatsuno H, Ueno Y, Ullom JN, Watanabe S, Yamada S. Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon. Phys Rev Lett 2023; 130:173001. [PMID: 37172243 DOI: 10.1103/physrevlett.130.173001] [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] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/10/2023] [Accepted: 03/10/2023] [Indexed: 05/14/2023]
Abstract
To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst) eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.
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Affiliation(s)
- T Okumura
- Atomic, Molecular, and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - T Azuma
- Atomic, Molecular, and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - D A Bennett
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - I Chiu
- Institute for Radiation Sciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - W B Doriese
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - M S Durkin
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J W Fowler
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J D Gard
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - T Hashimoto
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai 319-1184, Japan
| | - R Hayakawa
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - G C Hilton
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Y Ichinohe
- Department of Physics, Rikkyo University, Tokyo 171-8501, Japan
| | - P Indelicato
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Case 74, 4, place Jussieu, 75005 Paris, France
| | - T Isobe
- RIKEN Nishina Center, RIKEN, Wako 351-0198, Japan
| | - S Kanda
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Katsuragawa
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - N Kawamura
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Y Kino
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - K Mine
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - Y Miyake
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K M Morgan
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - K Ninomiya
- Institute for Radiation Sciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Noda
- Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G C O'Neil
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - S Okada
- Engineering Science Laboratory, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - K Okutsu
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - N Paul
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Case 74, 4, place Jussieu, 75005 Paris, France
| | - C D Reintsema
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - D R Schmidt
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - K Shimomura
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - P Strasser
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Suda
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - D S Swetz
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - T Takahashi
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - S Takeda
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - S Takeshita
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Tampo
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Tatsuno
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Y Ueno
- Atomic, Molecular, and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - J N Ullom
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - S Watanabe
- Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210, Japan
| | - S Yamada
- Department of Physics, Rikkyo University, Tokyo 171-8501, Japan
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Johanson KE, DeFreece CB, Morgan KM. Enhancing the Mentoring Experience for Underrepresented Students. J Chem Educ 2022; 99:508-512. [PMID: 36090672 PMCID: PMC9456019 DOI: 10.1021/acs.jchemed.1c00461] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Undergraduate research is a valuable experience that increases the likelihood of a STEM major to continue on to postgraduate training in their field. For students from groups underrepresented in the biomedical sciences, a strong mentoring relationship during this undergraduate period is a key component in preparing them for the next stage of their education and can have a significant influence on their ability to persist in the pipeline. Although the ideal scenario to increase the diversity of the biomedical workforce is to provide more BIPOC (Black, Indigenous, People of Color) faculty mentors for our undergraduates, we also need to develop strategies to provide strong mentoring experiences for our BIPOC students when those mentors are not in great number. At Xavier University of Louisiana, we have used our NIH BUILD Project Pathways program to look more closely at the mentor matching process. Throughout the past seven years, we have moved from the traditional mentor, research-focused matching process to a student-centered process. The lessons learned here can be used by any University looking to craft an inclusive undergraduate research program to meet the needs of all students, but in particular a diverse student population.
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Affiliation(s)
- Kelly E Johanson
- Department of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Cecily B DeFreece
- Department of Biology, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Kathleen M Morgan
- Department of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
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Okumura T, Azuma T, Bennett DA, Caradonna P, Chiu I, Doriese WB, Durkin MS, Fowler JW, Gard JD, Hashimoto T, Hayakawa R, Hilton GC, Ichinohe Y, Indelicato P, Isobe T, Kanda S, Kato D, Katsuragawa M, Kawamura N, Kino Y, Kubo MK, Mine K, Miyake Y, Morgan KM, Ninomiya K, Noda H, O'Neil GC, Okada S, Okutsu K, Osawa T, Paul N, Reintsema CD, Schmidt DR, Shimomura K, Strasser P, Suda H, Swetz DS, Takahashi T, Takeda S, Takeshita S, Tampo M, Tatsuno H, Tong XM, Ueno Y, Ullom JN, Watanabe S, Yamada S. Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays. Phys Rev Lett 2021; 127:053001. [PMID: 34397250 DOI: 10.1103/physrevlett.127.053001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kβ x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.
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Affiliation(s)
- T Okumura
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - T Azuma
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - D A Bennett
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - P Caradonna
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - I Chiu
- Department of Chemistry, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - W B Doriese
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - M S Durkin
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J W Fowler
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J D Gard
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - T Hashimoto
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai 319-1184, Japan
| | - R Hayakawa
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - G C Hilton
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Y Ichinohe
- Department of Physics, Rikkyo University, Tokyo 171-8501, Japan
| | - P Indelicato
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Case 74, 4, place Jussieu, 75005 Paris, France
| | - T Isobe
- RIKEN Nishina Center, RIKEN, Wako 351-0198, Japan
| | - S Kanda
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - D Kato
- National Institute for Fusion Science (NIFS), Toki, Gifu 509-5292, Japan
| | - M Katsuragawa
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - N Kawamura
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Y Kino
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - M K Kubo
- Department of Natural Sciences, College of Liberal Arts, International Christian University, Mitaka, Tokyo 181-8585, Japan
| | - K Mine
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - Y Miyake
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K M Morgan
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - K Ninomiya
- Department of Chemistry, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Noda
- Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - G C O'Neil
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - S Okada
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - K Okutsu
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - T Osawa
- Materials Sciences Research Center (MSRC), Japan Atomic Energy Agency (JAEA), Tokai 319-1184, Japan
| | - N Paul
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Case 74, 4, place Jussieu, 75005 Paris, France
| | - C D Reintsema
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - D R Schmidt
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - K Shimomura
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - P Strasser
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Suda
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - D S Swetz
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - T Takahashi
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - S Takeda
- Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
| | - S Takeshita
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Tampo
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Tatsuno
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - X M Tong
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Y Ueno
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Wako 351-0198, Japan
| | - J N Ullom
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - S Watanabe
- Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210, Japan
| | - S Yamada
- Department of Physics, Rikkyo University, Tokyo 171-8501, Japan
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9
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Fowler JW, O’Neil GC, Alpert BK, Bennett DA, Denison EV, Doriese WB, Hilton GC, Hudson LT, Joe YI, Morgan KM, Schmidt DR, Swetz DS, Szabo CI, Ullom JN. Absolute energies and emission line shapes of the L x-ray transitions of lanthanide metals. Metrologia 2021; 58:10.1088/1681-7575/abd28a. [PMID: 34354301 PMCID: PMC8335601 DOI: 10.1088/1681-7575/abd28a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We use an array of transition-edge sensors, cryogenic microcalorimeters with 4 eV energy resolution, to measure L x-ray emission-line profiles of four elements of the lanthanide series: praseodymium, neodymium, terbium, and holmium. The spectrometer also surveys numerous x-ray standards in order to establish an absolute-energy calibration traceable to the international system of units for the energy range 4 keV to 10 keV. The new results include emission line profiles for 97 lines, each expressed as a sum of one or more Voigt functions; improved absolute energy uncertainty on 71 of these lines relative to existing reference data; a median uncertainty on the peak energy of 0.24 eV, four to ten times better than the median of prior work; and six lines that lack any measured values in existing reference tables. The 97 lines comprise nearly all of the most intense L lines from these elements under broad-band x-ray excitation. The work improves on previous measurements made with a similar cryogenic spectrometer by the use of sensors with better linearity in the absorbed energy and a gold x-ray absorbing layer that has a Gaussian energy-response function. It also employs a novel sample holder that enables rapid switching between science targets and calibration targets with excellent gain balancing. Most of the results for peak energy values shown here should be considered as replacements for the currently tabulated standard reference values, while the line shapes given here represent a significant expansion of the scope of available reference data.
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Affiliation(s)
- J W Fowler
- Department of Physics, University of Colorado, Boulder, CO 80309, United States of America
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - G C O’Neil
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - B K Alpert
- Applied & Computational Mathematics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - D A Bennett
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - E V Denison
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - W B Doriese
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - G C Hilton
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - L T Hudson
- Radiation Physics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
| | - Y-I Joe
- Department of Physics, University of Colorado, Boulder, CO 80309, United States of America
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - K M Morgan
- Department of Physics, University of Colorado, Boulder, CO 80309, United States of America
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - D R Schmidt
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - D S Swetz
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
| | - C I Szabo
- Radiation Physics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
- Theiss Research, 7411 Eads Ave, La Jolla, CA 92037, United States of America
| | - J N Ullom
- Department of Physics, University of Colorado, Boulder, CO 80309, United States of America
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America
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10
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Durkin M, Adams JS, Bandler SR, Chervenak JA, Chaudhuri S, Dawson CS, Denison EV, Doriese WB, Duff SM, Finkbeiner FM, FitzGerald CT, Fowler JW, Gard JD, Hilton GC, Irwin KD, Joe YI, Kelley RL, Kilbourne CA, Miniussi AR, Morgan KM, O'Neil GC, Pappas CG, Porter FS, Reintsema CD, Rudman DA, SaKai K, Smith SJ, Stevens RW, Swetz DS, Szypryt P, Ullom JN, Vale LR, Wakeham N, Weber JC, Young BA. Demonstration of Athena X-IFU Compatible 40-Row Time-Division-Multiplexed Readout. IEEE Trans Appl Supercond 2019; 29:2101005. [PMID: 31160861 PMCID: PMC6544157 DOI: 10.1109/tasc.2019.2904472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Time-division multiplexing (TDM) is the backup readout technology for the X-ray Integral Field Unit (X-IFU), a 3,168-pixel X-ray transition-edge sensor (TES) array that will provide imaging spectroscopy for ESA's Athena satellite mission. X-0IFU design studies are considering readout with a multiplexing factor of up to 40. We present data showing 40-row TDM readout (32 TES rows + 8 repeats of the last row) of TESs that are of the same type as those being planned for X-IFU, using measurement and analysis parameters within the ranges specified for X-IFU. Singlecolumn TDM measurements have best-fit energy resolution of (1.91 ± 0.01) eV for the Al Kα complex (1.5 keV), (2.10 ± 0.02) eV for Ti Kα (4.5 keV), (2.23 ± 0.02) eV for Mn Kα (5.9 keV), (2.40 ± 0.02) eV for Co Kα (6.9 keV), and (3.44 ± 0.04) eV for Br Kα (11.9 keV). Three-column measurements have best-fit resolution of (2.03 ± 0.01) eV for Ti Kα and (2.40 ± 0.01) eV for Co Kα. The degradation due to the multiplexed readout ranges from 0.1 eV at the lower end of the energy range to 0.5 eV at the higher end. The demonstrated performance meets X-IFU's energy-resolution and energy-range requirements. True 40-row TDM readout, without repeated rows, of kilopixel scale arrays of X-IFU-like TESs is now under development.
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Affiliation(s)
- M Durkin
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J S Adams
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - S R Bandler
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - J A Chervenak
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - S Chaudhuri
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - C S Dawson
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - E V Denison
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - W B Doriese
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - S M Duff
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - F M Finkbeiner
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - C T FitzGerald
- Santa Clara University Dept. of Physics, Santa Clara, CA 95053 USA
| | - J W Fowler
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J D Gard
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - G C Hilton
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - K D Irwin
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - Y I Joe
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - R L Kelley
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - C A Kilbourne
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - A R Miniussi
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - K M Morgan
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - G C O'Neil
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - C G Pappas
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - F S Porter
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - C D Reintsema
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - D A Rudman
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - K SaKai
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - S J Smith
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - R W Stevens
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - D S Swetz
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - P Szypryt
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J N Ullom
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - L R Vale
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - N Wakeham
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - J C Weber
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - B A Young
- Santa Clara University Dept. of Physics, Santa Clara, CA 95053 USA
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11
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Jaeckel FT, Ambarish CV, Christensen N, Gruenke R, Hu L, McCammon D, McPheron M, Meyer M, Nelms KL, Roy A, Wulf D, Zhang S, Zhou Y, Adams JS, Bandler SR, Chervenak JA, Datesman AM, Eckart ME, Ewin AJ, Finkbeiner FM, Kelley R, Kilbourne CA, Miniussi AR, Porter FS, Sadleir JE, Sakai K, Smith SJ, Wakeham N, Wassell E, Yoon W, Morgan KM, Schmidt DR, Swetz DS, Ullom JN. Energy calibration of high-resolution X-Ray TES microcalorimeters with 3 eV optical photons. IEEE Trans Appl Supercond 2019; 29:2100104. [PMID: 31186605 PMCID: PMC6557579 DOI: 10.1109/tasc.2019.2899856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
With the improving energy resolution of transitionedge sensor (TES) based microcalorimeters, performance verification and calibration of these detectors has become increasingly challenging, especially in the energy range below 1 keV where fluorescent atomic X-ray lines have linewidths that are wider than the detector energy resolution and require impractically high statistics to determine the gain and deconvolve the instrumental profile. Better behaved calibration sources such as grating monochromators are too cumbersome for space missions and are difficult to use in the lab. As an alternative, we are exploring the use of pulses of 3 eV optical photons delivered by an optical fiber to generate combs of known energies with known arrival times. Here, we discuss initial results of this technique obtained with 2 eV and 0.7 eV resolution X-ray microcalorimeters. With the 2 eV detector, we have achieved photon number resolution for pulses with mean photon number up to 133 (corresponding to 0.4 keV).
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Affiliation(s)
- F T Jaeckel
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - C V Ambarish
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - N Christensen
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - R Gruenke
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - L Hu
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - D McCammon
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - M McPheron
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - M Meyer
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - K L Nelms
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - A Roy
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - D Wulf
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - S Zhang
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - Y Zhou
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706
| | - J S Adams
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - S R Bandler
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - J A Chervenak
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - A M Datesman
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - M E Eckart
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - A J Ewin
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - F M Finkbeiner
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - R Kelley
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - C A Kilbourne
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - A R Miniussi
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - F S Porter
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - J E Sadleir
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - K Sakai
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - S J Smith
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - N Wakeham
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - E Wassell
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - W Yoon
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771
| | - K M Morgan
- National Institute for Standards and Technology, 325 Broadway, Boulder, CO 80305
| | - D R Schmidt
- National Institute for Standards and Technology, 325 Broadway, Boulder, CO 80305
| | - D S Swetz
- National Institute for Standards and Technology, 325 Broadway, Boulder, CO 80305
| | - J N Ullom
- National Institute for Standards and Technology, 325 Broadway, Boulder, CO 80305
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12
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Doriese WB, Bandler SR, Chaudhuri S, Dawson CS, Denison EV, Duff SM, Durkin M, FitzGerald CT, Fowler JW, Gard JD, Hilton GC, Irwin KD, Joe YI, Morgan KM, O'Neil GC, Pappas CG, Reintsema CD, Rudman DA, Smith SJ, Stevens RW, Swetz DS, Szypryt P, Ullom JN, Vale LR, Weber JC, Young BA. Optimization of Time- and Code-Division-Multiplexed Readout for Athena X-IFU. IEEE Trans Appl Supercond 2019; 29:10.1109/TASC.2019.2905577. [PMID: 31360051 PMCID: PMC6662226 DOI: 10.1109/tasc.2019.2905577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Readout of a large, spacecraft-based array of superconducting transition-edge sensors (TESs) requires careful management of the layout area and power dissipation of the cryogenic-circuit components. We present three optimizations of our time- (TDM) and code-division-multiplexing (CDM) systems for the X-ray Integral Field Unit (X-IFU), a several-thousand-pixel-TES array for the planned Athena-satellite mission. The first optimization is a new readout scheme that is a hybrid of CDM and TDM. This C/TDM architecture balances CDM's noise advantage with TDM's layout compactness. The second is a redesign of a component: the shunt resistor that provides a dc-voltage bias to the TESs. A new layout and a thicker Pd-Au resistive layer combine to reduce this resistor's area by more than a factor of 5. Third, we have studied the power dissipated by the first-stage SQUIDs (superconducting quantum-interference devices) and the readout noise versus the critical current of the first-stage SqUIDs. As a result, the X-IFU TDM and C/TDM SQUIDs will have a specified junction critical current of 5 μA. Based on these design optimizations and TDM experiments described by Durkin, et al. (these proceedings), TDM meets all requirements to be X-IFU's backup-readout option. Hybrid C/TDM is another viable option that could save spacecraft resources.
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Affiliation(s)
- W B Doriese
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - S R Bandler
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - S Chaudhuri
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - C S Dawson
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - E V Denison
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - S M Duff
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - M Durkin
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - C T FitzGerald
- Santa Clara University Dept. of Physics, Santa Clara, CA 95053 USA
| | - J W Fowler
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J D Gard
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - G C Hilton
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - K D Irwin
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
| | - Y I Joe
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - K M Morgan
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - G C O'Neil
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - C G Pappas
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - C D Reintsema
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - D A Rudman
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - S J Smith
- National Aeronautics and Space Administration, Greenbelt, MD 20771 USA
| | - R W Stevens
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - D S Swetz
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - P Szypryt
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J N Ullom
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - L R Vale
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - J C Weber
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - B A Young
- Stanford University Dept. of Physics, Stanford, CA 94305 USA
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13
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Zhou Y, Ambarish CV, Gruenke R, Jaeckel FT, Kripps KL, McCammon D, Morgan KM, Wulf D, Zhang S, Adams JS, Bandler SR, Chervenak JA, Datesman AM, Eckart ME, Ewin AJ, Finkbeiner FM, Kelley RL, Kilbourne CA, Miniussi AR, Porter FS, Sadleir JE, Sakai K, Smith SJ, Wakeham NA, Wassell EJ, Yoon W. Mapping TES Temperature Sensitivity and Current Sensitivity as a Function of Temperature, Current, and Magnetic Field with IV curve and Complex Admittance Measurements. J Low Temp Phys 2018; 193:321-327. [PMID: 31186584 PMCID: PMC6557576 DOI: 10.1007/s10909-018-1970-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 05/14/2018] [Indexed: 06/09/2023]
Abstract
We have specialized astronomical applications for X-ray microcalorimeters with superconducting transition edge sensors (TESs) that require exceptionally good TES performance, but which operate in the small-signal regime. We have therefore begun a program to carefully characterize the entire transition surface of TESs with and without the usual zebra stripes to see if there are reproducible local "sweet spots" where the performance is much better than average. These measurements require precise knowledge of the circuit parameters. Here, we show how the Shapiro effect can be used to precisely calibrate the value of the shunt-resistor. We are also investigating the effects of stress and external magnetic fields to better understand reproducibility problems.
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Affiliation(s)
- Y Zhou
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - C V Ambarish
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - R Gruenke
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - F T Jaeckel
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - K L Kripps
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - D McCammon
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - K M Morgan
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - D Wulf
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - S Zhang
- Physics Department, University of Wisconsin - Madison, Madison, WI, USA
| | - J S Adams
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - S R Bandler
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J A Chervenak
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - A M Datesman
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - M E Eckart
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - A J Ewin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - R L Kelley
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C A Kilbourne
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - A R Miniussi
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - F S Porter
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J E Sadleir
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - K Sakai
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - S J Smith
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - N A Wakeham
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - E J Wassell
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - W Yoon
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
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14
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Doriese WB, Abbamonte P, Alpert BK, Bennett DA, Denison EV, Fang Y, Fischer DA, Fitzgerald CP, Fowler JW, Gard JD, Hays-Wehle JP, Hilton GC, Jaye C, McChesney JL, Miaja-Avila L, Morgan KM, Joe YI, O'Neil GC, Reintsema CD, Rodolakis F, Schmidt DR, Tatsuno H, Uhlig J, Vale LR, Ullom JN, Swetz DS. A practical superconducting-microcalorimeter X-ray spectrometer for beamline and laboratory science. Rev Sci Instrum 2017; 88:053108. [PMID: 28571411 DOI: 10.1063/1.4983316] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We describe a series of microcalorimeter X-ray spectrometers designed for a broad suite of measurement applications. The chief advantage of this type of spectrometer is that it can be orders of magnitude more efficient at collecting X-rays than more traditional high-resolution spectrometers that rely on wavelength-dispersive techniques. This advantage is most useful in applications that are traditionally photon-starved and/or involve radiation-sensitive samples. Each energy-dispersive spectrometer is built around an array of several hundred transition-edge sensors (TESs). TESs are superconducting thin films that are biased into their superconducting-to-normal-metal transitions. The spectrometers share a common readout architecture and many design elements, such as a compact, 65 mK detector package, 8-column time-division-multiplexed superconducting quantum-interference device readout, and a liquid-cryogen-free cryogenic system that is a two-stage adiabatic-demagnetization refrigerator backed by a pulse-tube cryocooler. We have adapted this flexible architecture to mate to a variety of sample chambers and measurement systems that encompass a range of observing geometries. There are two different types of TES pixels employed. The first, designed for X-ray energies below 10 keV, has a best demonstrated energy resolution of 2.1 eV (full-width-at-half-maximum or FWHM) at 5.9 keV. The second, designed for X-ray energies below 2 keV, has a best demonstrated resolution of 1.0 eV (FWHM) at 500 eV. Our team has now deployed seven of these X-ray spectrometers to a variety of light sources, accelerator facilities, and laboratory-scale experiments; these seven spectrometers have already performed measurements related to their applications. Another five of these spectrometers will come online in the near future. We have applied our TES spectrometers to the following measurement applications: synchrotron-based absorption and emission spectroscopy and energy-resolved scattering; accelerator-based spectroscopy of hadronic atoms and particle-induced-emission spectroscopy; laboratory-based time-resolved absorption and emission spectroscopy with a tabletop, broadband source; and laboratory-based metrology of X-ray-emission lines. Here, we discuss the design, construction, and operation of our TES spectrometers and show first-light measurements from the various systems. Finally, because X-ray-TES technology continues to mature, we discuss improvements to array size, energy resolution, and counting speed that we anticipate in our next generation of TES-X-ray spectrometers and beyond.
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Affiliation(s)
- W B Doriese
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - P Abbamonte
- Department of Physics, University of Illinois, Urbana, Illinois 61801, USA
| | - B K Alpert
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - D A Bennett
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - E V Denison
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Y Fang
- Department of Physics, University of Illinois, Urbana, Illinois 61801, USA
| | - D A Fischer
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - C P Fitzgerald
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J W Fowler
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J D Gard
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J P Hays-Wehle
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - G C Hilton
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - C Jaye
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J L McChesney
- Argonne National Laboratory, Advanced Photon Source, Argonne, Illinois 60439, USA
| | - L Miaja-Avila
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - K M Morgan
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Y I Joe
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - G C O'Neil
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - C D Reintsema
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - F Rodolakis
- Argonne National Laboratory, Advanced Photon Source, Argonne, Illinois 60439, USA
| | - D R Schmidt
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - H Tatsuno
- Department of Chemical Physics, Lund University, Lund, Sweden
| | - J Uhlig
- Department of Chemical Physics, Lund University, Lund, Sweden
| | - L R Vale
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - J N Ullom
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - D S Swetz
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
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15
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Perry CT, Morgan KM. Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs. Sci Rep 2017; 7:40581. [PMID: 28084450 PMCID: PMC5233991 DOI: 10.1038/srep40581] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [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: 11/08/2016] [Accepted: 12/07/2016] [Indexed: 11/26/2022] Open
Abstract
Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m−2 yr−1) to strongly net negative (mean −2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to −0.4 mm yr−1. Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability.
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Affiliation(s)
- C T Perry
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, United Kingdom
| | - K M Morgan
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, United Kingdom
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16
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Wulf D, Jaeckel F, McCammon D, Morgan KM. Technique for Recovering Pile-up Events from Microcalorimeter Data. J Low Temp Phys 2016; 184:431-435. [PMID: 31359887 PMCID: PMC6662219 DOI: 10.1007/s10909-015-1445-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/21/2015] [Indexed: 06/09/2023]
Abstract
We report here a technique for processing microcalorimeter data that offers improved live-time over conventional optimal filtering techniques without loss of spectral resolution. Separate filters optimized for pulse amplitude and pulse arrival time (constructed in the usual way from the averaged signal and noise spectral densities) are applied to the entire pixel data stream. Pulses in the resulting filtered streams are then simultaneously fit as the sum of scaled and shifted copies of an isolated filtered pulse template. Analysis using calibration data from the University of Wisconsin/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC) sounding rocket payload demonstrates the ability of this technique to recover pulses separated by as little as the rise-time of the detectors without observable spectral broadening.
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Affiliation(s)
- D Wulf
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - F Jaeckel
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - D McCammon
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - K M Morgan
- Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA
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17
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Porterfield JP, Baraban JH, Troy TP, Ahmed M, McCarthy MC, Morgan KM, Daily JW, Nguyen TL, Stanton JF, Ellison GB. Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO−CH2OH), and Glyoxal in a Heated Microreactor. J Phys Chem A 2016; 120:2161-72. [DOI: 10.1021/acs.jpca.6b00652] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Tyler P. Troy
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, United States
| | - Kathleen M. Morgan
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125-1098, United States
| | | | - Thanh Lam Nguyen
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - John F. Stanton
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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18
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Chilvers BL, Morgan KM, Finlayson G, Sievwright KA. Diving behaviour of wildlife impacted by an oil spill: A clean-up and rehabilitation success? Mar Pollut Bull 2015; 100:128-133. [PMID: 26424224 DOI: 10.1016/j.marpolbul.2015.09.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [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: 06/22/2015] [Revised: 09/10/2015] [Accepted: 09/15/2015] [Indexed: 06/05/2023]
Abstract
The value of rehabilitating oiled wildlife is an on-going global debate. On October 5, 2011, the cargo vessel C/V Rena grounded on Astrolabe Reef, New Zealand (NZ), spilling over 300 tonnes of heavy fuel oil. As part of the Rena oil spill response, 383 little blue penguins (LBP, Eudyptula minor) were captured, cleaned, rehabilitated and released back into a cleaned environment. This research investigates foraging behaviour changes due either to the oil spill or by the rehabilitation process by comparing the diving behaviour of rehabilitated (n=8) and non-rehabilitated (n=6) LBPs and with LBP populations throughout NZ. Stabile isotope analysis of feathers was also used to investigate diet. There were no foraging behaviour differences between rehabilitated and non-rehabilitated LBPs and the overall diving behaviour of these LBPs have similar, if not less energetic, foraging behaviour than other LBPs in NZ. This suggests the rehabilitation process and clean-up undertaken after the Rena appears effective and helps justify the rehabilitation of oiled wildlife across the world.
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Affiliation(s)
- B L Chilvers
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
| | - K M Morgan
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - G Finlayson
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - K A Sievwright
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
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Morgan KM, Ashline DJ, Morgan JP, Greenberg A. Electrospray ionization (ESI) fragmentations and dimethyldioxirane reactivities of three diverse lactams having full, half, and zero resonance energies. J Org Chem 2014; 79:517-28. [PMID: 24313276 PMCID: PMC3959984 DOI: 10.1021/jo402041u] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 01/18/2023]
Abstract
Three lactams having, respectively, ~20, ~10, and 0 kcal/mol of resonance energy have been subjected to electrospray ionization mass spectrometry (ESI/MS) as well as to attempted reaction with dimethyldioxirane (DMDO). The ESI/MS for all three lactams are consistent with fragmentation from the N-protonated, rather than the O-protonated tautomer. Each exhibits a unique fragmentation pathway. DFT calculations are employed to provide insights concerning these pathways. N-Ethyl-2-pyrrolidinone and 1-azabicyclo[3.3.1]nonan-2-one, the full- and half-resonance lactams, are unreactive with DMDO. The "Kirby lactam" (3,5,7-trimethyl-1-azaadamantan-2-one) has zero resonance energy and reacts rapidly with DMDO to generate a mixture of reaction products. The structure assigned to one of these is the 2,2-dihydroxy-N-oxide, thought to be stabilized by intramolecular hydrogen bonding and buttressing by the methyl substituents. A reasonable pathway to this derivative might involve formation of an extremely labile N-oxide, in a purely formal sense, an example of the hitherto-unknown amide N-oxides, followed by hydration with traces of moisture.
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Affiliation(s)
- Kathleen M. Morgan
- Department of Chemistry, Xavier University of Louisiana, New Orleans, LA 70125
| | - David J. Ashline
- The Glycomics Center, University of New Hampshire, Durham, NH 03824
| | - Jessica P. Morgan
- Department of Chemistry, University of New Hampshire, Durham, NH 03824
| | - Arthur Greenberg
- Department of Chemistry, University of New Hampshire, Durham, NH 03824
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Abstract
Gas-phase heats of formation for the four butene oxide isomers are reported. They were obtained by measuring the condensed-phase heat of reduction to the corresponding alcohol using reaction calorimetry. Heats of vaporization were determined and allow gas-phase heats of formation to be obtained. The experimental measurements are compared to calculations obtained using a variety of computational methods. Overall, the G3 and CBS-APNO methods agree quite well with the experimental data. The influence of alkyl substituents on epoxide stability is discussed. Comparisons to alkenes, cyclopropanes, aziridines, thiiranes, and phosphiranes are also made. Isodesmic-type reactions were used to determine strain energies of the epoxides and related compounds with various substituents.
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Affiliation(s)
- Kathleen M Morgan
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans Louisiana 70125, United States.
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21
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Abstract
The base-induced rearrangement of aziridines has been examined using a combination of calculations and experiment. The calculations show that the substituent on nitrogen is a critical feature that greatly affects the favorability of both α-deprotonation, and β-elimination to form an allylic amine. Experiments were carried out to determine whether E2-like rearrangement to the allylic amine with lithium diisopropyl amide (LDA) is possible. N-Tosyl aziridines were found to deprotonate on the tosyl group, preventing further reaction. A variety of N-benzenesulfonyl aziridines having both α- and β-protons decomposed when treated with LDA in either tetrahydrofuran or hexamethylphosphoramide. However, when α-protons were not present, allylic amine was formed, presumably via β-elimination.
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Affiliation(s)
- Kathleen M Morgan
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans LA 70125, USA
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22
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Morgan KM, Kench PS. Skeletal extension and calcification of reef-building corals in the central Indian Ocean. Mar Environ Res 2012; 81:78-82. [PMID: 22925734 DOI: 10.1016/j.marenvres.2012.08.001] [Citation(s) in RCA: 10] [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] [Received: 05/30/2012] [Revised: 08/01/2012] [Accepted: 08/03/2012] [Indexed: 06/01/2023]
Abstract
Skeletal extension, density and calcification rate of 12 scleractinian coral species comprising 7 morphological groups were examined on the reef crest of Vabbinfaru platform, Maldives. Growth rates of coral specimens were measured over the period of February 2010-March 2011 using alizarin staining and direct measurements. Skeletal extension rate was highly variable between coral species. Colony morphology was a major control on the skeletal extension and calcification of coral specimens. Growth rates of Acropora and Porites corals were comparable to existing data recorded for Caribbean and Indo-Pacific reef provinces. Skeletal density was less variable between species and was typically consistent among morphological groups. Findings represent the first estimates of coral growth in the central Indian Ocean region and add to the limited growth studies available that have examined a broad range of coral growth morphologies in other reef-building regions.
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Affiliation(s)
- K M Morgan
- School of Environment, The University of Auckland, New Zealand.
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23
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Zhu N, Lightsey D, Liu J, Foroozesh M, Morgan KM, Stevens ED, Klein Stevens CL. Ethynyl and Propynylpyrene Inhibitors of Cytochrome P450. J Chem Crystallogr 2010; 40:343-352. [PMID: 20473363 PMCID: PMC2869100 DOI: 10.1007/s10870-009-9659-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The single-crystal X-ray structures and in vivo activities of three aryl acetylenic inhibitors of cytochromes P450 1A1, 1A2, 2A6, and 2B1 have been determined and are reported herein. These are 1-ethynylpyrene, 1-propy-nylpyrene, and 4-propynylpyrene. To investigate electronic influences on the mechanism of enzyme inhibition, the experimental electron density distribution of 1-ethynylpy-rene has been determined using low-temperature X-ray diffraction measurements, and the resulting net atomic charges compared with various theoretical calculations. A total of 82,390 reflections were measured with Mo Kα radiation to a (sinθ/λ)(max) = 0.985 Å(-1). Averaging symmetry equivalent reflections yielded 8,889 unique reflections. A least squares refinement procedure was used in which multipole parameters were added to describe the distortions of the atomic electron distributions from spherical symmetry. A map of the model electron density distribution of 1-ethynylpyrene was obtained. Net atomic charges calculated from refined monopole population parameters yielded charges that showed that the terminal acetylenic carbon atom (C18) is more negative than the internal carbon (C17). Net atomic charges calculated by ab initio, density functional theory, and semi-empirical methods are consistent with this trend suggesting that the terminal acetylenic carbon atom is more likely to be the site of oxidation. This is consistent with the inhibition mechanism pathway that results in the formation of a reactive ketene intermediate. This is also consistent with assay results that determined that 1-ethynylpyrene acts as a mechanism-based inhibitor of P450s 1A1 and 1A2 and as a reversible inhibitor of P450 2B1. Crystallographic data: 1-ethynylpyrene, C(18)H(10), P2(1)/c, a = 14.571(2) Å, b = 3.9094(5) Å, c = 20.242(3) Å, β = 105.042(2)°, V = 1,113.5(2) Å(3); 1-propynylpyrene, C(19)H(12), P2(1)/n, a = 8.970(2) Å, b = 10.136(1) Å, c = 14.080(3) Å, β = 99.77(2)°, V = 1,261.5(4) Å(3); 4-propynylpyrene, C(19)H(12), Pbca, a = 9.904(1) Å, b = 13.174(2) Å, c = 19.401(1) Å, V = 2,531.4(5) Å(3).
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Affiliation(s)
- Naijue Zhu
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
| | - Danielle Lightsey
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
| | - Jiawang Liu
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
| | - Maryam Foroozesh
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
| | - Kathleen M. Morgan
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
| | - Edwin D. Stevens
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA
| | - Cheryl L. Klein Stevens
- Department of Chemistry, Xavier University of Louisiana, One Drexel Drive, New Orleans, LA 70125, USA
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24
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Morgan KM, Rawlins ML, Montgomery MN. Influence of methyl substituents on the stability of 1-aza-2-adamantanone, Kirby's most twisted amide. J PHYS ORG CHEM 2005. [DOI: 10.1002/poc.855] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Wiberg KB, Crocker LS, Morgan KM. Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups. J Am Chem Soc 2002. [DOI: 10.1021/ja00009a033] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [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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Henke SL, Hadad CM, Morgan KM, Wiberg KB, Wasserman HH. A theoretical and experimental investigation of vicinal tricarbonyl systems and their hydrates. J Org Chem 2002. [DOI: 10.1021/jo00062a029] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [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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31
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Rahman MM, Secor BA, Morgan KM, Shafer PR, Lemal DM. Valence isomerization equilibria of highly fluorinated cycloocta-1,3,5-trienes. J Am Chem Soc 2002. [DOI: 10.1021/ja00172a011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [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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Florig HK, Morgan MG, Morgan KM, Jenni KE, Fischhoff B, Fischbeck PS, DeKay ML. A deliberative method for ranking risks (I): Overview and test bed development. Risk Anal 2001; 21:913-921. [PMID: 11798126 DOI: 10.1111/0272-4332.215161] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Risk ranking offers a potentially powerful means for gathering public input to help set risk-management priorities. In most rankings conducted to date, the categories and attributes used to describe the risks have varied widely, the materials and procedures have not been designed to facilitate comparisons among risks on all important attributes, and the validity and reproducibility of the resulting rankings have not been assessed. To address these needs, a risk-ranking method was developed in which risk experts define and categorize the risks to be ranked, identify the relevant risk attributes, and characterize the risks in a set of standardized risk summary sheets, which are then used by lay or other groups in structured ranking exercises. To evaluate this method, a test bed involving 22 health and safety risks in a fictitious middle school was created. This article provides an overview of the risk-ranking method and describes the challenges faced in designing the middle school test bed. A companion article in this issue reports on the validity of the ranking procedures and the level of agreement among risk managers regarding ranking of risks and attributes.
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Affiliation(s)
- H K Florig
- Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213-3890, USA.
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33
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Morgan KM, DeKay ML, Fischbeck PS, Morgan MG, Fischhoff B, Florig HK. A deliberative method for ranking risks (II): Evaluation of validity and agreement among risk managers. Risk Anal 2001; 21:923-937. [PMID: 11798127 DOI: 10.1111/0272-4332.215162] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A deliberative method for ranking risks was evaluated in a study involving 218 risk managers. Both holistic and multiattribute procedures were used to assess individual and group rankings of health and safety risks facing students at a fictitious middle school. Consistency between the rankings that emerged from these two procedures was reasonably high for individuals and for groups, suggesting that these procedures capture an underlying construct of riskiness. Participants reported high levels of satisfaction with their groups' decision-making processes and the resulting rankings, and these reports were corroborated by regression analyses. Risk rankings were similar across individuals and groups, even though individuals and groups did not always agree on the relative importance of risk attributes. Lower consistency between the risk rankings from the holistic and multiattribute procedures and lower agreement among individuals and groups regarding these rankings were observed for a set of high-variance risks. Nonetheless, the generally high levels of consistency, satisfaction, and agreement suggest that this deliberative method is capable of producing risk rankings that can serve as informative inputs to public risk-management decision making.
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Affiliation(s)
- K M Morgan
- Research Triangle Institute, Washington, DC, USA
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Morgan KM, O'Connor MJ, Humphrey JL, Buschman KE. An experimental and computational study of 1,2-hydrogen migrations in 2-hydroxycyclopentylidene and its conjugate base. J Org Chem 2001; 66:1600-6. [PMID: 11262102 DOI: 10.1021/jo001038x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thermal decomposition of alpha-hydroxydiazirine 2 gives primarily cyclopentanone and some allylic alcohol, in similar amounts as the known cyclohexyl analogue 1. Calculations (B3LYP/6-31+G) also show cyclopentanone to be the major product of this carbene rearrangement. Diazirine 2 and the lithium salt of the corresponding conjugate base 3 were decomposed by photolysis. The proportion of ketone formed increases with deprotonation, a trend also found computationally. In comparison, the base-induced isomerization of cyclopentene oxide, which proceeds via alpha-elimination to a carbenoid intermediate similar to that obtained from 3, yields primarily allylic alcohol rather than ketone; neither ring size nor charge thus accounts for the unusual product distribution observed. Interestingly, the calculations reveal that in the gas phase with no counterion, the singlet, oxyanionic carbene, and the alpha-deprotonated epoxide are the same, rather than discrete structures. This intramolecular complexation stablilizes the oxyanionic carbene by 20-25 kcal/mol.
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Affiliation(s)
- K M Morgan
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, VA 23187-8795, USA.
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Meredith D, Temple CS, Guha N, Sword CJ, Boyd CA, Collier ID, Morgan KM, Bailey PD. Modified amino acids and peptides as substrates for the intestinal peptide transporter PepT1. Eur J Biochem 2000; 267:3723-8. [PMID: 10848990 DOI: 10.1046/j.1432-1327.2000.01405.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The binding affinities of a number of amino-acid and peptide derivatives by the mammalian intestinal peptide transporter PepT1 were investigated, using the Xenopus laevis expression system. A series of blocked amino acids, namely N-acetyl-Phe (Ac-Phe), phe-amide (Phe-NH2), N-acetyl-Phe-amide (Ac-Phe-NH2) and the parent compound Phe, was compared for efficacy in inhibiting the uptake of the peptide [3H]-D-Phe-L-Gln. In an equivalent set of experiments, the blocked peptides Ac-Phe-Tyr, Phe-Tyr-NH2 and Ac-Phe-Tyr-NH2 were compared with the parent compound Phe-Tyr. Comparing amino acids and derivatives, only Ac-Phe was an effective inhibitor of peptide uptake (Ki = 1.81+/- 0.37 mM). Ac-Phe-NH2 had a very weak interaction with PepT1 (Ki = 16.8+/-5.64 mM); neither Phe nor Phe-NH2 interacted with PepT1 with measurable affinity. With the dipeptide and derivatives, unsurprisingly the highest affinity interaction was with Phe-Tyr (Ki = 0.10+/-0.04 mM). The blocked C-terminal peptide Phe-Tyr-NH2 also interacted with PepT1 with a relatively high affinity (Ki = 0.94+/-0.38 mM). Both Ac-Phe-Tyr and Ac-Phe-Tyr-NH2 interacted weakly with PepT1 (Ki = 8.41+/-0.11 and 9.97+/-4.01 mM, respectively). The results suggest that the N-terminus is the primary binding site for both dipeptides and tripeptides. Additional experiments with four stereoisomers of Ala-Ala-Ala support this conclusion, and lead us to propose that a histidine residue is involved in binding the C-terminus of dipeptides. In addition, a substrate binding model for PepT1 is proposed.
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Affiliation(s)
- D Meredith
- Department of Human Anatomy & Genetics, South Parks Road, Oxford, UK.
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Abstract
By building key structural features into hydrophilic drugs, they can be recognized by the PepT1 transporter system of the small intestine and rendered orally active. The model shown provides, for the first time, a 3D template for all known substrates of PepT1.
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Affiliation(s)
- PD Bailey
- Department of Human Anatomy and Genetics University of Oxford, South Parks Road, Oxford, OX1 3QX (UK)
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Morgan KM, Chapman RJ. Retrospective analysis of an implant system. Compend Contin Educ Dent 1999; 20:609-14, 616-23 passim; quiz 626. [PMID: 10650379] [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] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The reliability of dental implants results from a combination of design, placement, and reconstructive techniques. Retrospective analysis is one vehicle for evaluating implant success. This article presents the reliability of these techniques in Bicon dental implants. The survivability of this implant was evaluated retrospectively using life table survival analysis over a 10-year period in 13 practices. The parameters used for success included no implant loss, no mobility, no continuing bone loss that did not stabilize after 1 year, no discomfort, and no purulence.
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Affiliation(s)
- K M Morgan
- Dental Implant Centre, Faulkner Hospital, Boston, Massachusetts, USA
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Meredith D, Boyd CA, Bronk JR, Bailey PD, Morgan KM, Collier ID, Temple CS. 4-aminomethylbenzoic acid is a non-translocated competitive inhibitor of the epithelial peptide transporter PepT1. J Physiol 1998; 512 ( Pt 3):629-34. [PMID: 9882198 PMCID: PMC2231240 DOI: 10.1111/j.1469-7793.1998.629bd.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [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] [Received: 07/15/1998] [Accepted: 09/14/1998] [Indexed: 11/29/2022] Open
Abstract
1. 4-Aminomethylbenzoic acid, a molecule which mimics the special configuration of a dipeptide, competitively inhibits peptide influx in both Xenopus Laevis oocytes expressing rabbit PepT1 and through PepT1 in rat renal brush border membrane vesicles. 2. This molecule is not translocated through PepT1 as measured both by direct HPLC analysis in PepT1-exp ressing oocytes and indirectly by its failure to trans-stimulate labelle d peptide efflux through PepT1 in oocytes and in renal membrane vessicle s. 3. However 4-aminiomethylbenzoic acid does reverse trans-stimulation through expressed PepT1 of labelled peptid efflux induced by unlabelled peptide. Quantitatively this reversal is compatible with 4-aminomethyl benzoic acid competitively binding to the external surface of PepT1. 4. 4-Aminomethylbenzoic acid (the first molecule discovered to be a non-translocated competitive inhibitor of proton-coupled oligopeptide transport) and its derivatives may thus be particularly useful as experimental tools.
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Affiliation(s)
- D Meredith
- Department of Human Anatomy, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
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Temple CS, Stewart AK, Meredith D, Lister NA, Morgan KM, Collier ID, Vaughan-Jones RD, Boyd CA, Bailey PD, Bronk JR. Peptide mimics as substrates for the intestinal peptide transporter. J Biol Chem 1998; 273:20-2. [PMID: 9417040 DOI: 10.1074/jbc.273.1.20] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [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: 02/05/2023] Open
Abstract
4-Aminophenylacetic acid (4-APAA), a peptide mimic lacking a peptide bond, has been shown to interact with a proton-coupled oligopeptide transporter using a number of different experimental approaches. In addition to inhibiting transport of labeled peptides, these studies show that 4-APAA is itself translocated. 4-APAA transport across the rat intact intestine was stimulated 18-fold by luminal acidification (to pH 6.8) as determined by high performance liquid chromatography (HPLC); in enterocytes isolated from mouse small intestine the intracellular pH was reduced on application of 4-APAA, as shown fluorimetrically with the pH indicator carboxy-SNARF; 4-APAA trans-stimulated radiolabeled peptide transport in brush-border membrane vesicles isolated from rat renal cortex; and in Xenopus oocytes expressing PepT1, 4-APAA produced trans-stimulation of radiolabeled peptide efflux, and as determined by HPLC, was a substrate for translocation by this transporter. These results with 4-APAA show for the first time that the presence of a peptide bond is not a requirement for rapid translocation through the proton-linked oligopeptide transporter (PepT1). Further investigation will be needed to determine the minimal structural requirements for a molecule to be a substrate for this transporter.
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Affiliation(s)
- C S Temple
- Department of Human Anatomy, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom
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Koblinsky SA, Morgan KM, Anderson EA. African-American homeless and low-income housed mothers: comparison of parenting practices. Am J Orthopsychiatry 1997; 67:37-47. [PMID: 9034020 DOI: 10.1037/h0080209] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The child-rearing practices of homeless and low-income housed mothers of preschool children in Head Start were compared. Overall, homeless mothers provided less learning and academic stimulation, less variety in social and cultural experiences, less warmth and affection, and a less positive physical environment for their children than did housed mothers. Mothers in both living arrangements provided more language stimulation to daughters than to sons. Implications of the findings for working with homeless families are discussed.
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Affiliation(s)
- S A Koblinsky
- Department of Family Studies, University of Maryland, College Park, USA
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Morgan KM, Gajewski JJ. Mechanisms of the Base-Induced Isomerizations of Cyclopentene and Cyclohexene Oxides: Influence of Structure and Solvent on α and β Proton Removal. J Org Chem 1996. [DOI: 10.1021/jo951981e] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Candidal endophthalmitis is most commonly due to hematogenous seeding of the eye by Candida albicans. Although it is most often seen as a manifestation of disseminated candidiasis in patients who are seriously ill, other patients may have candidal endophthalmitis as the only evidence of fungal infection. We have presented a case of endophthalmitis due to C albicans in a patient who had bilateral renal calculi and who had received multiple antibiotics and extracorporeal shock wave lithotripsy.
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Affiliation(s)
- B D Greenwald
- Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908
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Litzenberger R, Morgan KM, Marden SF, Jacobs-Irvine KN, Bray SA. A nursing approach to the management of type IIA hyperlipidemia: case study of a young adult. J Cardiovasc Nurs 1991; 5:58-66. [PMID: 1987335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This case study illustrates the chronic nature of hyperlipidemia type IIa and the important contribution of the nurse in helping the client adjust life style, manage complex health regimes, and cope with the uncertainty of disease progression and its associated risks.
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Abstract
We studied five patients who maintained or spontaneously regained significant central vision despite the presence of a subfoveal neovascular membrane. Sequential photographs and fluorescein angiograms showed a pattern of development common to these patients and not observed in patients who lose all central vision. The pattern involves formation of a pigmented ring around the subfoveal neovascular membrane followed by alteration of the membrane from one that leaks fluorescein to one that stains but does not leak. This pattern is associated with gradual resorption of subretinal fluid and apparent limitation of subretinal hemorrhage and fibrosis. This course suggests the occurrence of spontaneous involution of some subfoveal neovascular membranes and implicates the retinal pigment epithelium in this process.
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Affiliation(s)
- P A Campochiaro
- Department of Ophthalmology, University of Virginia Health Sciences Center, Charlottesville 22908
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Wyszynski RE, Bruner WE, Cano DB, Morgan KM, Davis CB, Sternberg P. A donor-age-dependent change in the activity of alpha-mannosidase in human cultured RPE cells. Invest Ophthalmol Vis Sci 1989; 30:2341-7. [PMID: 2807791] [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: 01/02/2023] Open
Abstract
Six acidic glycosidase activities in cultured human retinal pigment epithelium (RPE) cells from donors of different ages (19 to 80 years) were studied with regard to pH optimum, Km, Vmax and specific activity. For alpha-mannosidase we found significant age-dependent decreases in specific activity and Vmax but not in Km. The other glycosidases and acid phosphatase, lactate dehydrogenase (LDH) and citrate synthase showed no change in these parameters with donor age. The alpha mannosidase activity of older donor cells could be activated almost 2-fold by the addition of zinc. This is the first report of age-dependent change in a human RPE lysosomal enzyme. Since alpha-mannosidase is probably required for the degradation of rhodopsin in the phagolysosomal system of the RPE, decrease in this enzyme activity may lead to accumulation of undigested rod outer segments (ROS) and drusen, both of which are associated with age-related macular degeneration (AMD).
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Affiliation(s)
- R E Wyszynski
- Veterans Administration Medical Center, Case Western Reserve University, Cleveland, Ohio
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Lass JH, Reinhart WJ, Bruner WE, Kachmer ML, Lomeo MD, Morgan KM, Glavan I, Sanders DR. Comparison of corneal storage in K-Sol and chondroitin sulfate corneal storage medium in human corneal transplantation. Ophthalmology 1989; 96:688-97. [PMID: 2501722 DOI: 10.1016/s0161-6420(89)32853-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [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: 01/01/2023] Open
Abstract
Fifty-one pairs of corneas, stored in either K-Sol or CSM (chondroitin sulfate corneal storage medium) from 8 to 97 hours (mean +/- standard deviation, 58 +/- 21 and 57 +/- 21 hours, respectively), were transplanted in a prospective, randomized manner into 99 patients (n = 102 eyes), paired by diagnostic group and procedure. Ninety-six percent of K-Sol grafts (n = 51) and 94% of the CSM grafts (n = 51) were clear at 6 months; 92% of both the K-Sol (n = 38) and CSM (n = 35) grafts were clear at 12 months. One primary donor failure occurred, a K-Sol cornea stored for 76 hours. The CSM group experienced a greater number of persistent epithelial defects beyond 2 weeks (7 versus 4 defects) and graft reaction episodes (7 versus 3 episodes) than the K-Sol group; however, an equal number of late graft failures (3) occurred in both groups. No significant differences by paired t test analyses were found in endothelial cell density, area, coefficient of variation, or figure coefficient at 3 (n = 37 pairs), 6 (n = 36 pairs), and 12 (n = 26 pairs) months between the two groups. Mean endothelial cell density significantly decreased by 11% +/- 22 by 3 months in the K-Sol group, whereas the 7% +/- 24 decrease in the CSM group was insignificant. By 12 months, both groups experienced a significant decrease: K-Sol, 27% +/- 22; CSM, 17% +/- 26. A significant decrease in the mean coefficient of variation (polymegathism) was noted after 3 months in the K-Sol group which returned to the preoperative mean by 1 year, whereas this parameter remained unchanged in the CSM group. Both chondroitin sulfate-based media result in successful corneal transplantation with storage up to 4 days; however, endothelial survival with both media are comparable with previous studies with McCarey-Kaufman (M-K) medium.
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Affiliation(s)
- J H Lass
- Division of Ophthalmology, Case Western Reserve University, Cleveland,OH
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Wyszynski RE, Vahey JB, Manning L, Bruner WE, Morgan KM, Burney EN. Sustained release of 5-fluorouracil from ethylene acetate copolymer. J Ocul Pharmacol 1989; 5:141-6. [PMID: 2754299 DOI: 10.1089/jop.1989.5.141] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pharmacologic inhibition of fibroblast proliferation and scar formation remains an important consideration in many ophthalmologic surgical procedures. Such inhibition is particularly important in glaucoma filtration surgery. A sustained release system for 5-fluorouracil (5-FU) using ethylene vinyl acetate copolymer (Elvax) was characterized in vitro. 5-FU was incorporated into Elvax discs of 4 mm diameter. Discs were coated to allow sustained and predictable release over a 14 day period. Alteration of coatings, which act as rate-controlling membranes, allowed variation in the pattern of 5-FU release from the core which acts as the drug reservoir. This system for the sustained release of 5-FU may prove valuable in glaucoma surgery where the suppression of cellular proliferation is desired. The non-inflammatory nature of Elvax suggests this compound may provide an alternative means of 5-FU delivery.
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Affiliation(s)
- R E Wyszynski
- Veterans Administration Medical Center, Case Western Reserve University, Cleveland, Ohio
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Abstract
Evidence indicates that lysosomal enzymes can carry out corneal autolysis during corneal storage and that they are damaging to the corneal endothelium. The authors investigated the release of lysosomal enzymes into two corneal storage media (K-Sol and McCarey-Kaufman [M-K]) by paired human donor corneas during 4 degrees C storage. The authors also studied the interaction of these media with lysosomal enzymes from human cornea. K-Sol and M-K stimulated (P less than 0.01) both beta-glucuronidase and alpha-galactosidase about equally. beta-N-Acetyl-glucosaminidase, a major catabolic enzyme of the cornea, was inhibited by the chondroitin sulfate in K-Sol by over 90% (P less than 0.01). Corneas stored in M-K released more lysosomal enzymes than corneas stored in K-Sol. At 4 days, the values approached significance (P less than 0.06) and by day 10 significantly higher values were found in the M-K media (P less than 0.01). Both storage methods showed a linear release. Individual corneas were found to vary in their release rates. Whether corneas that release more enzyme will show higher endothelial cell loss or produce less successful penetrating keratoplasty grafts deserves further study.
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Affiliation(s)
- K M Morgan
- Case Western Reserve University, VA Medical Center, Cleveland, OH
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