1
|
Belov V, Erwin-Grabner T, Aghajani M, Aleman A, Amod AR, Basgoze Z, Benedetti F, Besteher B, Bülow R, Ching CRK, Connolly CG, Cullen K, Davey CG, Dima D, Dols A, Evans JW, Fu CHY, Gonul AS, Gotlib IH, Grabe HJ, Groenewold N, Hamilton JP, Harrison BJ, Ho TC, Mwangi B, Jaworska N, Jahanshad N, Klimes-Dougan B, Koopowitz SM, Lancaster T, Li M, Linden DEJ, MacMaster FP, Mehler DMA, Melloni E, Mueller BA, Ojha A, Oudega ML, Penninx BWJH, Poletti S, Pomarol-Clotet E, Portella MJ, Pozzi E, Reneman L, Sacchet MD, Sämann PG, Schrantee A, Sim K, Soares JC, Stein DJ, Thomopoulos SI, Uyar-Demir A, van der Wee NJA, van der Werff SJA, Völzke H, Whittle S, Wittfeld K, Wright MJ, Wu MJ, Yang TT, Zarate C, Veltman DJ, Schmaal L, Thompson PM, Goya-Maldonado R. Multi-site benchmark classification of major depressive disorder using machine learning on cortical and subcortical measures. Sci Rep 2024; 14:1084. [PMID: 38212349 PMCID: PMC10784593 DOI: 10.1038/s41598-023-47934-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 11/19/2023] [Indexed: 01/13/2024] Open
Abstract
Machine learning (ML) techniques have gained popularity in the neuroimaging field due to their potential for classifying neuropsychiatric disorders. However, the diagnostic predictive power of the existing algorithms has been limited by small sample sizes, lack of representativeness, data leakage, and/or overfitting. Here, we overcome these limitations with the largest multi-site sample size to date (N = 5365) to provide a generalizable ML classification benchmark of major depressive disorder (MDD) using shallow linear and non-linear models. Leveraging brain measures from standardized ENIGMA analysis pipelines in FreeSurfer, we were able to classify MDD versus healthy controls (HC) with a balanced accuracy of around 62%. But after harmonizing the data, e.g., using ComBat, the balanced accuracy dropped to approximately 52%. Accuracy results close to random chance levels were also observed in stratified groups according to age of onset, antidepressant use, number of episodes and sex. Future studies incorporating higher dimensional brain imaging/phenotype features, and/or using more advanced machine and deep learning methods may yield more encouraging prospects.
Collapse
Affiliation(s)
- Vladimir Belov
- Laboratory of Systems Neuroscience and Imaging in Psychiatry (SNIP-Lab), Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Georg-August University, Von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Tracy Erwin-Grabner
- Laboratory of Systems Neuroscience and Imaging in Psychiatry (SNIP-Lab), Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Georg-August University, Von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Moji Aghajani
- Department of Psychiatry, Amsterdam UMC, Amsterdam Neuroscience, Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Institute of Education and Child Studies, Section Forensic Family and Youth Care, Leiden University, Leiden, The Netherlands
| | - Andre Aleman
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alyssa R Amod
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Zeynep Basgoze
- Department of Psychiatry and Behavioral Science, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Francesco Benedetti
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Bianca Besteher
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Robin Bülow
- Institute for Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany
| | - Christopher R K Ching
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Colm G Connolly
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Kathryn Cullen
- Department of Psychiatry and Behavioral Science, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Christopher G Davey
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Danai Dima
- Department of Psychology, School of Arts and Social Sciences, City, University of London, London, UK
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Annemiek Dols
- Department of Psychiatry, Amsterdam UMC, Amsterdam Neuroscience, Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jennifer W Evans
- Experimental Therapeutics and Pathophysiology Branch, National Institute for Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Cynthia H Y Fu
- School of Psychology, University of East London, London, UK
- Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Ali Saffet Gonul
- SoCAT Lab, Department of Psychiatry, School of Medicine, Ege University, Izmir, Turkey
| | - Ian H Gotlib
- Department of Psychology, Stanford University, Stanford, CA, USA
| | - Hans J Grabe
- Department of Psychiatry and Psychotherapy, University Medicine Greifswald, Greifswald, Germany
| | - Nynke Groenewold
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - J Paul Hamilton
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Center for Medical Imaging and Visualization, Linköping University, Linköping, Sweden
| | - Ben J Harrison
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Tiffany C Ho
- Department of Psychiatry and Behavioral Sciences, Division of Child and Adolescent Psychiatry, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Benson Mwangi
- Louis A. Faillace, MD, Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center Of Excellence On Mood Disorders, Louis A. Faillace, MD, Department of Psychiatry and Behavioral Sciences at McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Natalia Jaworska
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Neda Jahanshad
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | | | | | - Thomas Lancaster
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK
- MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Meng Li
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - David E J Linden
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK
- MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
- School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Frank P MacMaster
- Departments of Psychiatry and Pediatrics, University of Calgary, Calgary, AB, Canada
| | - David M A Mehler
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK
- MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany
| | - Elisa Melloni
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Bryon A Mueller
- Department of Psychiatry and Behavioral Science, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Amar Ojha
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mardien L Oudega
- Department of Psychiatry, Amsterdam UMC, Amsterdam Neuroscience, Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Brenda W J H Penninx
- Department of Psychiatry, Amsterdam UMC, Amsterdam Neuroscience, Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Sara Poletti
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Edith Pomarol-Clotet
- FIDMAG Germanes Hospitalàries Research Foundation, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Catalonia, Spain
| | - Maria J Portella
- Sant Pau Mental Health Research Group, Institut de Recerca de L'Hospital de La Santa Creu I Sant Pau, Barcelona, Catalonia, Spain
| | - Elena Pozzi
- Centre for Youth Mental Health, The University of Melbourne, Parkville, VIC, Australia
- Orygen, Parkville, VIC, Australia
| | - Liesbeth Reneman
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Matthew D Sacchet
- Meditation Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Anouk Schrantee
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Kang Sim
- West Region, Institute of Mental Health, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jair C Soares
- Center Of Excellence On Mood Disorders, Louis A. Faillace, MD, Department of Psychiatry and Behavioral Sciences at McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Dan J Stein
- SA MRC Research Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry and Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Sophia I Thomopoulos
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Aslihan Uyar-Demir
- SoCAT Lab, Department of Psychiatry, School of Medicine, Ege University, Izmir, Turkey
| | - Nic J A van der Wee
- Leiden Institute for Brain and Cognition, Leiden University Medical Center, Leiden, The Netherlands
| | - Steven J A van der Werff
- Leiden Institute for Brain and Cognition, Leiden University Medical Center, Leiden, The Netherlands
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
| | - Henry Völzke
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Sarah Whittle
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, VIC, Australia
| | - Katharina Wittfeld
- Department of Psychiatry and Psychotherapy, University Medicine Greifswald, Greifswald, Germany
- German Center for Neurodegenerative Diseases (DZNE), Site Rostock/ Greifswald, Greifswald, Germany
| | - Margaret J Wright
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Mon-Ju Wu
- Louis A. Faillace, MD, Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center Of Excellence On Mood Disorders, Louis A. Faillace, MD, Department of Psychiatry and Behavioral Sciences at McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Tony T Yang
- Department of Psychiatry and Behavioral Sciences, Division of Child and Adolescent Psychiatry, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Carlos Zarate
- Section on the Neurobiology and Treatment of Mood Disorders, National Institute of Mental Health, Bethesda, MD, USA
| | - Dick J Veltman
- Department of Psychiatry, Amsterdam UMC, Amsterdam Neuroscience, Amsterdam Public Health Research Institute, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Lianne Schmaal
- Centre for Youth Mental Health, The University of Melbourne, Parkville, VIC, Australia
- Orygen, Parkville, VIC, Australia
| | - Paul M Thompson
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Roberto Goya-Maldonado
- Laboratory of Systems Neuroscience and Imaging in Psychiatry (SNIP-Lab), Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Georg-August University, Von-Siebold-Str. 5, 37075, Göttingen, Germany.
| |
Collapse
|
2
|
Lancaster T, Creese B, Escott-Price V, Driver I, Menzies G, Khan Z, Corbett A, Ballard C, Williams J, Murphy K, Chandler H. Proof-of-concept recall-by-genotype study of extremely low and high Alzheimer's polygenic risk reveals autobiographical deficits and cingulate cortex correlates. Alzheimers Res Ther 2023; 15:213. [PMID: 38087383 PMCID: PMC10714651 DOI: 10.1186/s13195-023-01362-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023]
Abstract
BACKGROUND Genome-wide association studies demonstrate that Alzheimer's disease (AD) has a highly polygenic architecture, where thousands of independent genetic variants explain risk with high classification accuracy. This AD polygenic risk score (AD-PRS) has been previously linked to preclinical cognitive and neuroimaging features observed in asymptomatic individuals. However, shared variance between AD-PRS and neurocognitive features are small, suggesting limited preclinical utility. METHODS Here, we recruited sixteen clinically asymptomatic individuals (mean age 67; range 58-76) with either extremely low / high AD-PRS (defined as at least 2 standard deviations from the wider sample mean (N = 4504; N EFFECTIVE = 90)) with comparable age sex and education level. We assessed group differences in autobiographical memory and T1-weighted structural neuroimaging features. RESULTS We observed marked reductions in autobiographical recollection (Cohen's d = - 1.66; P FDR = 0.014) and midline structure (cingulate) thickness (Cohen's d = - 1.55, P FDR = 0.05), with no difference in hippocampal volume (P > 0.3). We further confirm the negative association between AD-PRS and cingulate thickness in a larger study with a comparable age (N = 31,966, β = - 0.002, P = 0.011), supporting the validity of our approach. CONCLUSIONS These observations conform with multiple streams of prior evidence suggesting alterations in cingulate structures may occur in individuals with higher AD genetic risk. We were able to use a genetically informed research design strategy that significantly improved the efficiency and power of the study. Thus, we further demonstrate that the recall-by-genotype of AD-PRS from wider samples is a promising approach for the detection, assessment, and intervention in specific individuals with increased AD genetic risk.
Collapse
Affiliation(s)
- Thomas Lancaster
- Department of Psychology, University of Bath, Bath, UK.
- School of Physics and Astronomy, Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, UK.
- Dementia Research Institute (UKDRI), Cardiff University, Cardiff, UK.
| | - Byron Creese
- Department of Clinical and Biomedical Science, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
- Department of Life Sciences, Brunel University London, Uxbridge, west London, UK
| | - Valentina Escott-Price
- Division of Neuroscience and Mental Health, School of Medicine, Cardiff University, Cardiff, UK
| | - Ian Driver
- School of Physics and Astronomy, Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, UK
| | - Georgina Menzies
- Dementia Research Institute (UKDRI), Cardiff University, Cardiff, UK
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Zunera Khan
- Institute of Psychiatry, King's College London, Psychology & Neuroscience, London, UK
| | - Anne Corbett
- Deptartment of Health & Community Sciences, University of Exeter, Exeter, UK
| | - Clive Ballard
- Department of Clinical and Biomedical Science, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Julie Williams
- Dementia Research Institute (UKDRI), Cardiff University, Cardiff, UK
| | - Kevin Murphy
- School of Physics and Astronomy, Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, UK
| | - Hannah Chandler
- School of Physics and Astronomy, Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, UK
| |
Collapse
|
3
|
Opherden D, Tepaske MSJ, Bärtl F, Weber M, Turnbull MM, Lancaster T, Blundell SJ, Baenitz M, Wosnitza J, Landee CP, Moessner R, Luitz DJ, Kühne H. Field-Tunable Berezinskii-Kosterlitz-Thouless Correlations in a Heisenberg Magnet. Phys Rev Lett 2023; 130:086704. [PMID: 36898116 DOI: 10.1103/physrevlett.130.086704] [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: 09/14/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
We report the manifestation of field-induced Berezinskii-Kosterlitz-Thouless (BKT) correlations in the weakly coupled spin-1/2 Heisenberg layers of the molecular-based bulk material [Cu(pz)_{2}(2-HOpy)_{2}](PF_{6})_{2}. At zero field, a transition to long-range order occurs at 1.38 K, caused by a weak intrinsic easy-plane anisotropy and an interlayer exchange of J^{'}/k_{B}≈1 mK. Because of the moderate intralayer exchange coupling of J/k_{B}=6.8 K, the application of laboratory magnetic fields induces a substantial XY anisotropy of the spin correlations. Crucially, this provides a significant BKT regime, as the tiny interlayer exchange J^{'} only induces 3D correlations upon close approach to the BKT transition with its exponential growth in the spin-correlation length. We employ nuclear magnetic resonance measurements to probe the spin correlations that determine the critical temperatures of the BKT transition as well as that of the onset of long-range order. Further, we perform stochastic series expansion quantum Monte Carlo simulations based on the experimentally determined model parameters. Finite-size scaling of the in-plane spin stiffness yields excellent agreement of critical temperatures between theory and experiment, providing clear evidence that the nonmonotonic magnetic phase diagram of [Cu(pz)_{2}(2-HOpy)_{2}](PF_{6})_{2} is determined by the field-tuned XY anisotropy and the concomitant BKT physics.
Collapse
Affiliation(s)
- D Opherden
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - M S J Tepaske
- Physikalisches Institut, Universität Bonn, Nussallee 12, 53115 Bonn, Germany
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| | - F Bärtl
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
| | - M Weber
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| | - M M Turnbull
- Carlson School of Chemistry, Clark University, Worcester, Massachusetts 01610, USA
| | - T Lancaster
- Department of Physics, Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - S J Blundell
- Clarendon Laboratory, Department of Physics, University of Oxford, Park Road, Oxford OX1 3PU, United Kingdom
| | - M Baenitz
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - J Wosnitza
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
| | - C P Landee
- Department of Physics, Clark University, Worcester, Massachusetts 01610, USA
| | - R Moessner
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| | - D J Luitz
- Physikalisches Institut, Universität Bonn, Nussallee 12, 53115 Bonn, Germany
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| | - H Kühne
- Hochfeld-Magnetlabor Dresden (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| |
Collapse
|
4
|
Hulsebosch SE, Pires J, Bannasch MJ, Lancaster T, Delpero A, Ragupathy R, Murikipudi S, Zion T, Gilor C. Ultra-long-acting recombinant insulin for the treatment of diabetes mellitus in dogs. J Vet Intern Med 2022; 36:1211-1219. [PMID: 35621084 PMCID: PMC9308417 DOI: 10.1111/jvim.16449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 05/10/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND For the treatment of diabetes mellitus (DM) in dogs, novel insulins with decreased injection frequency while maintaining safety and efficacy are desirable. Insulin fused with immunoglobulin-fragment-crystallizable (Fc) has an ultra-long plasma half-life because it recycles through cells, protected from proteolysis. HYPOTHESIS Glycemic control can be achieved in diabetic dogs with a recombinant fusion protein of a synthetic insulin and canine Fc (AKS-218d) administered subcutaneously once-weekly. ANIMALS Five client-owned dogs with naturally occurring DM. METHODS Prospective clinical trial in dogs with DM that were recruited from the UC Davis Veterinary Teaching Hospital and local veterinary clinics. Dogs previously controlled using intermediate-acting insulin q12h were transitioned to once-weekly injections of a preliminary construct identified as AKS-218d. The dose of AKS-218d was titrated weekly for 8 weeks based on clinical response and continuous interstitial glucose monitoring. Clinical signs, body weight, serum fructosamine concentrations, and mean interstitial glucose concentrations (IG) over the preceding week were compared between baseline (before AKS-218d) and during the last week of treatment. Data were compared using nonparametric paired tests. RESULTS Once-weekly AKS-218d, compared to baseline twice-daily insulin therapy, resulted in no significant changes in clinical signs, median (range) body weight (+0.4 kg [-0.5-1.1]; P = .6), fructosamine concentration (-75 mmol/L [-215 to +126]; P = .4), or mean IG (+81 mg/dL [-282 to +144]; P = .8). No adverse reactions were reported. CONCLUSION Control of clinical signs, body weight, and maintenance of glycemia was achieved with this once-weekly novel insulin construct in 4 of 5 dogs.
Collapse
Affiliation(s)
- Sean E. Hulsebosch
- Department of Veterinary Medicine and EpidemiologyUniversity of CaliforniaDavisCaliforniaUSA
| | - Jully Pires
- Veterinary Medical Teaching HospitalUniversity of CaliforniaDavisCaliforniaUSA
| | - Michael J. Bannasch
- Veterinary Medical Teaching HospitalUniversity of CaliforniaDavisCaliforniaUSA
| | | | | | | | | | - Todd Zion
- Akston BiosciencesBeverlyMassachusettsUSA
| | - Chen Gilor
- Department of Veterinary Medicine and EpidemiologyUniversity of CaliforniaDavisCaliforniaUSA,Department of Small Animal Clinical SciencesUniversity of Florida, College of Veterinary MedicineGainesvilleFloridaUSA
| |
Collapse
|
5
|
McLauchlan DJ, Lancaster T, Craufurd D, Linden DEJ, Rosser AE. Different depression: motivational anhedonia governs antidepressant efficacy in Huntington's disease. Brain Commun 2022; 4:fcac278. [PMID: 36440100 PMCID: PMC9683390 DOI: 10.1093/braincomms/fcac278] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 04/13/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Depression is more common in neurodegenerative diseases such as Huntington's disease than the general population. Antidepressant efficacy is well-established for depression within the general population: a recent meta-analysis showed serotonin norepinephrine reuptake inhibitors, tricyclic antidepressants and mirtazapine outperformed other antidepressants. Despite the severe morbidity, antidepressant choice in Huntington's disease is based on Class IV evidence. We used complementary approaches to determine treatment choice for depression in Huntington's disease: propensity score analyses of antidepressant treatment outcome using the ENROLL-HD data set, and a dissection of the cognitive mechanisms underlying depression in Huntington's disease using a cognitive battery based on the Research Domain Criteria for Depression. Study 1 included ENROLL-HD 5486 gene-positive adult patients started on an antidepressant medication for depression. Our outcome measures were depression (Hospital Anxiety and Depression Scale or Problem Behaviours Assessment 'Depressed Mood' item) at first follow-up (primary outcome) and all follow-ups (secondary outcome). The intervention was antidepressant class. We used Svyglm&Twang in R to perform propensity scoring, using known variables (disease progression, medical comorbidity, psychiatric morbidity, sedatives, number of antidepressants, demographics and antidepressant contraindications) to determine the probability of receiving different antidepressants (propensity score) and then included the propensity score in a model of treatment efficacy. Study 2 recruited 51 gene-positive adult patients and 26 controls from the South Wales Huntington's Disease Management Service. Participants completed a motor assessment, in addition to measures of depression and apathy, followed by tasks measuring consummatory anhedonia, motivational anhedonia, learning from reward and punishment and reaction to negative outcome. We used generalised linear models to determine the association between task performance and depression scores. Study 1 showed selective serotonin reuptake inhibitors outperformed serotonin norepinephrine reuptake inhibitors on the primary outcome (P = 0.048), whilst both selective serotonin reuptake inhibitors (P = 0.00069) and bupropion (P = 0.0045) were superior to serotonin norepinephrine reuptake inhibitors on the secondary outcome. Study 2 demonstrated an association between depression score and effort for reward that was not explained by apathy. No other mechanisms were associated with depression score. We found that selective serotonin reuptake inhibitors and bupropion outperform serotonin norepinephrine reuptake inhibitors at alleviating depression in Huntington's disease. Moreover, motivational anhedonia appears the most significant mechanism underlying depression in Huntington's disease. Bupropion is improves motivational anhedonia and has a synergistic effect with selective serotonin reuptake inhibitors. This work provides the first large-scale, objective evidence to determine treatment choice for depression in Huntington's disease, and provides a model for determining antidepressant efficacy in other neurodegenerative diseases.
Collapse
Affiliation(s)
- Duncan James McLauchlan
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Neurology, Morriston Hospital, Swansea Bay University Health Board, Swansea SA6 6NL, UK
| | - Thomas Lancaster
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff CF24 4HQ, UK.,Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Psychology, University of Bath, Bath BA2 7AY, UK
| | - David Craufurd
- Manchester Center for Genomic Medicine, Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Center, Manchester M13 9PL, UK.,St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Center, Manchester M13 9WL, UK
| | - David E J Linden
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff CF24 4HQ, UK.,Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Psychology, University of Bath, Bath BA2 7AY, UK.,School for Mental Health and Neuroscience, Fac. Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Anne E Rosser
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Neurology, Morriston Hospital, Swansea Bay University Health Board, Swansea SA6 6NL, UK.,School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| |
Collapse
|
6
|
Huddart BM, Onuorah IJ, Isah MM, Bonfà P, Blundell SJ, Clark SJ, De Renzi R, Lancaster T. Intrinsic Nature of Spontaneous Magnetic Fields in Superconductors with Time-Reversal Symmetry Breaking. Phys Rev Lett 2021; 127:237002. [PMID: 34936766 DOI: 10.1103/physrevlett.127.237002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/27/2021] [Accepted: 10/27/2021] [Indexed: 06/14/2023]
Abstract
We present a systematic investigation of muon-stopping states in superconductors that reportedly exhibit spontaneous magnetic fields below their transition temperatures due to time-reversal symmetry breaking. These materials include elemental rhenium, several intermetallic systems, and Sr_{2}RuO_{4}. We demonstrate that the presence of the muon leads to only a limited and relatively localized perturbation to the local crystal structure, while any small changes to the electronic structure occur several electron volts below the Fermi energy, leading to only minimal changes in the charge density on ions close to the muon. Our results imply that the muon-induced perturbation alone is unlikely to lead to the observed spontaneous fields in these materials, whose origin is more likely intrinsic to the time-reversal symmetry-broken superconducting state.
Collapse
Affiliation(s)
- B M Huddart
- Department of Physics, Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - I J Onuorah
- Department of Mathematical, Physical and Computer Sciences, University of Parma, 43124 Parma, Italy
| | - M M Isah
- Department of Mathematical, Physical and Computer Sciences, University of Parma, 43124 Parma, Italy
| | - P Bonfà
- Department of Mathematical, Physical and Computer Sciences, University of Parma, 43124 Parma, Italy
| | - S J Blundell
- Department of Physics, Clarendon Laboratory, Oxford University, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S J Clark
- Department of Physics, Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - R De Renzi
- Department of Mathematical, Physical and Computer Sciences, University of Parma, 43124 Parma, Italy
| | - T Lancaster
- Department of Physics, Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| |
Collapse
|
7
|
Comas-Forgas R, Lancaster T, Calvo-Sastre A, Sureda-Negre J. Exam cheating and academic integrity breaches during the COVID-19 pandemic: An analysis of internet search activity in Spain. Heliyon 2021; 7:e08233. [PMID: 34722942 PMCID: PMC8539823 DOI: 10.1016/j.heliyon.2021.e08233] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 09/22/2021] [Accepted: 10/19/2021] [Indexed: 11/17/2022] Open
Abstract
Academic institutions worldwide have had to adapt their methods of teaching and assessment due to COVID-19. In many Spanish universities exams moved online, affording students with opportunities to breach academic integrity that were not previously available to them. This paper uses the emerging research method of search engine data analysis to investigate the extent of requests for exam cheating information in Spain in the time period surrounding adjustments for the pandemic. The Internet data analytics technique is one that the paper proposes should be used more widely as an academic integrity research method. For this study, search engine activity data on exam cheating in Spain was collected and analysed for the five-year period between 2016 and 2020 inclusive. The data suggests that students are searching for information about ways to cheat in exams, including how to create cheat sheets. Most strikingly, the results show a significant increase in requests for information on cheating on online exams during the COVID-19 timeframe and the Spanish lockdown period. Based on the findings, academic institutions in other regions should be wary about the opportunities that their students have to commit exam fraud.
Collapse
|
8
|
Gilor C, Hulsebosch SE, Pires J, Bannasch MJ, Lancaster T, Delpero A, Ragupathy R, Murikipudi S, Zion T. An ultra-long-acting recombinant insulin for the treatment of diabetes mellitus in cats. J Vet Intern Med 2021; 35:2123-2130. [PMID: 34190365 PMCID: PMC8478034 DOI: 10.1111/jvim.16150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Treatment of diabetes mellitus (DM) in cats typically requires insulin injections q12h-q24h, posing a major compliance barrier for caregivers. Novel treatments enabling decreased injection frequency while maintaining safety are highly desirable. Insulin fused with feline immunoglobulin fragment crystallizable (Fc) has an ultra-long plasma half-life because it recycles through cells where it is protected from proteolysis. HYPOTHESIS Glycemic control can be achieved in diabetic cats with a recombinant fusion protein of a synthetic insulin and feline Fc (AKS-267c) administered SC weekly. ANIMALS Five cats with spontaneous DM. METHODS Cats previously controlled using insulin glargine q12h were transitioned to once-weekly injection of AKS-267c. The dose of AKS-267c was titrated weekly for 7 weeks based on continuous glucose monitoring. Clinical signs, body weight, fructosamine concentrations, and mean interstitial glucose concentrations (IG) were compared between baseline (week 0, on insulin glargine) and the last week of treatment. Data were assessed for normality and compared using parametric or nonparametric paired tests (as appropriate). RESULTS After 7 weeks of once-weekly injections, compared to baseline, there were no significant changes in clinical signs, body weight (median [range] gain, 0.1 kg [-0.1 to +0.7]; P = .5), fructosamine (-60 mmol/L [-338 to +206]; P = .6), and mean IG concentrations (change = -153 mmol/L [-179 to +29]; P = .3), and no adverse reactions were reported. CONCLUSION Successful control of clinical signs and maintenance of glycemia was achieved with this once-weekly novel insulin treatment. The efficacy and safety of this novel formulation should be further assessed in a large clinical trial.
Collapse
Affiliation(s)
- Chen Gilor
- Department of Veterinary Medicine and EpidemiologyUniversity of California, DavisDavisCaliforniaUSA
- Department of Small Animal Clinical SciencesUniversity of Florida, College of Veterinary MedicineGainesvilleFloridaUSA
| | - Sean E. Hulsebosch
- Department of Veterinary Medicine and EpidemiologyUniversity of California, DavisDavisCaliforniaUSA
| | - Jully Pires
- Department of Veterinary Medicine and EpidemiologyUniversity of California, DavisDavisCaliforniaUSA
| | - Michael J. Bannasch
- Department of Veterinary Medicine and EpidemiologyUniversity of California, DavisDavisCaliforniaUSA
| | | | | | | | | | - Todd Zion
- Akston BiosciencesBeverlyMassachusettsUSA
| |
Collapse
|
9
|
Lancaster T. Academic Dishonesty or Academic Integrity? Using Natural Language Processing (NLP) Techniques to Investigate Positive Integrity in Academic Integrity Research. J Acad Ethics 2021. [DOI: 10.1007/s10805-021-09422-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractIs academic integrity research presented from a positive integrity standpoint? This paper uses Natural Language Processing (NLP) techniques to explore a data set of 8,507 academic integrity papers published between 1904 and 2019.Two main techniques are used to linguistically examine paper titles: (1) bigram (word pair) analysis and (2) sentiment analysis. The analysis sees the three main bigrams used in paper titles as being “academic integrity” (2.38%), “academic dishonesty” (2.06%) and “plagiarism detection” (1.05%). When only highly cited papers are considered, negative integrity bigrams dominate positive integrity bigrams. For example, the 100 most cited academic integrity papers of all time are three times more likely to have “academic dishonesty” included in their titles than “academic integrity”. Similarly, sentiment analysis sees negative sentiment outperforming positive sentiment in the most cited papers.The history of academic integrity research is seen to place the field at a disadvantage due to negative portrayals of integrity. Despite this, analysis shows that change towards positive integrity is possible. The titles of papers by the ten most prolific academic integrity researchers are found to use positive terminology in more cases that not. This suggests an approach for emerging academic integrity researchers to model themselves after.
Collapse
|
10
|
Lancaster T, Cotarlan C. Contract cheating by STEM students through a file sharing website: a Covid-19 pandemic perspective. Int J Educ Integr 2021; 17:3. [PMCID: PMC7857863 DOI: 10.1007/s40979-021-00070-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 01/06/2021] [Indexed: 05/29/2023]
Abstract
Students are using file sharing sites to breach academic integrity in light of the Covid-19 pandemic. This paper analyses the use of one such site, Chegg, which offers “homework help” and other academic services to students. Chegg is often presented as a file sharing site in the academic literature, but that is just one of many ways in which it can be used. As this paper demonstrates, Chegg can and is used for contract cheating This is despite the apparent existence of an Honour Code on Chegg which asks students not to breach academic integrity. With pandemic led safety considerations leading to increased online teaching and assessment, the paper analyses data relating to how Chegg is used by students in five STEM subjects, namely Computer Science, Mechanical Engineering, Electrical Engineering, Physics and Chemistry. The results show that students are using Chegg to request exam style questions. They demonstrate that contract cheating requests can be put live and answered within the short duration of an examination. The number of student requests posted for these five subjects increased by 196.25% comparing the time period April 2019 to August 2019 with the period April 2020 to August 2020. This increase corresponds with the time when many courses moved to be delivered and assessed online. The growing number of requests indicates that students are using Chegg for assessment and exam help frequently and in a way that is not considered permissible by universities. The paper concludes by recommending that academic institutions put interventions in place to minimise the risk to educational standards posed by sites such as Chegg, particularly since increased online teaching and assessment may continue after the pandemic.
Collapse
Affiliation(s)
| | - Codrin Cotarlan
- Department of Computing, Imperial College London, London, UK
| |
Collapse
|
11
|
Arh T, Gomilšek M, Prelovšek P, Pregelj M, Klanjšek M, Ozarowski A, Clark SJ, Lancaster T, Sun W, Mi JX, Zorko A. Origin of Magnetic Ordering in a Structurally Perfect Quantum Kagome Antiferromagnet. Phys Rev Lett 2020; 125:027203. [PMID: 32701346 DOI: 10.1103/physrevlett.125.027203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
The ground state of the simple Heisenberg nearest-neighbor quantum kagome antiferromagnetic model is a magnetically disordered spin liquid, yet various perturbations may lead to fundamentally different states. Here we disclose the origin of magnetic ordering in the structurally perfect kagome material YCu_{3}(OH)_{6}Cl_{3}, which is free of the widespread impurity problem. Ab initio calculations and modeling of its magnetic susceptibility reveal that, similar to the archetypal case of herbertsmithite, the nearest-neighbor exchange is by far the dominant isotropic interaction. Dzyaloshinskii-Moriya (DM) anisotropy deduced from electron spin resonance, susceptibility, and specific-heat data is, however, significantly larger than in herbertsmithite. By enhancing spin correlations within kagome planes, this anisotropy is essential for magnetic ordering. Our study isolates the effect of DM anisotropy from other perturbations and unambiguously confirms the predicted phase diagram.
Collapse
Affiliation(s)
- T Arh
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska u. 19, SI-1000 Ljubljana, Slovenia
| | - M Gomilšek
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
- Centre for Materials Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - P Prelovšek
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - M Pregelj
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - M Klanjšek
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - A Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - S J Clark
- Centre for Materials Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - T Lancaster
- Centre for Materials Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - W Sun
- Fujian Provincial Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian Province, People's Republic of China
| | - J-X Mi
- Fujian Provincial Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian Province, People's Republic of China
| | - A Zorko
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska u. 19, SI-1000 Ljubljana, Slovenia
| |
Collapse
|
12
|
Abstract
AbstractContract cheating services are marketing to students at discipline level, using increasingly sophisticated techniques. The discipline level reach of these services has not been widely considered in the academic integrity literature. Much of the academic understanding of contract cheating is not discipline specific, but the necessary solutions to this problem may need to vary by discipline. This paper reviews current knowledge about contract cheating services at the discipline level, including summarising four studies that rank the relative volume of contract cheating within different academic disciplines. The reviewed studies show high volumes of contract cheating transactions in the disciplines of Business and Computing. Examples of discipline level contract cheating research and service advertising are provided. The main contribution of the paper is an analysis of the discipline level reach by contract cheating services as seen through an analysis of Google search results from the United Kingdom. This analysis of 19 discipline groups uses measures of organic search engine results, paid results and competition. Three discipline groups are shown as currently being heavily exploited by essay mills; these are: (1) Architecture, Building and Planning, (2) Computer Science and (3) Law. In addition, the discipline group of Creative Arts and Design is shown to be at risk of future exploitation. The paper recommends that academics are made aware about continual change in the contract cheating industry including the involved marketing taking place at discipline level. The paper concludes with a call to action for academia to develop discipline specific solutions to contract cheating.
Collapse
|
13
|
Lancaster T, Huddart BM, Williams RC, Xiao F, Franke KJA, Baker PJ, Pratt FL, Blundell SJ, Schlueter JA, Mills MB, Maahs AC, Preuss KE. Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF 2(pyz) and [Ln(hfac) 3(boaDTDA)] n (Ln = Sm, La) using implanted muons. J Phys Condens Matter 2019; 31:394002. [PMID: 31239417 DOI: 10.1088/1361-648x/ab2cb6] [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] [Indexed: 06/09/2023]
Abstract
We present the results of muon-spin relaxation ([Formula: see text]SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF2(pyz) we identify a transition to long range magnetic order taking place at [Formula: see text] K, allowing us to estimate a ratio with the intrachain exchange of [Formula: see text] and the ratio of interchain to intrachain exchange coupling as [Formula: see text]. The ferromagnetic chain [Sm(hfac)3(boaDTDA)] n undergoes an ordering transition at [Formula: see text] K, seen via a broad freezing of dynamic fluctuations on the muon (microsecond) timescale and implying [Formula: see text]. The ordered radical moment continues to fluctuate on this timescale down to 0.3 K, while the Sm moments remain disordered. In contrast, the radical spins in [La(hfac)3(boaDTDA)] n remain magnetically disordered down to T = 0.1 K suggesting [Formula: see text].
Collapse
Affiliation(s)
- T Lancaster
- Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
El Ters N, Claassen C, Lancaster T, Barnette A, Eldridge W, Yazigi F, Brar K, Herco M, Rogowski L, Strand M, Vachharajani A. Central versus Low-Lying Umbilical Venous Catheters: A Multicenter Study of Practices and Complications. Am J Perinatol 2019; 36:1198-1204. [PMID: 30566998 DOI: 10.1055/s-0038-1676482] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Conventional neonatology practice is to place umbilical venous catheters (UVCs) in central position and to limit the use of low-lying catheters. Our objectives were to describe the practices and complications associated with UVCs and to evaluate the type of infusates used with either UVC position. STUDY DESIGN A retrospective chart review was performed at four neonatal intensive care units to identify neonates who underwent UVC placement over a 2-year period. Infant demographics, UVC position, catheter days, fluid and medication characteristics, and specific complications were extracted. RESULTS A total of 2,011 neonates who underwent UVC placement were identified during the 2-year period. Of these, 641 UVCs (31.9%) were identified in the low-lying position. Centrally positioned UVCs were associated with lower gestational age and were left in situ for a longer duration than low-lying UVCs. Infusions of hyperosmolar solutions and vasopressors were significantly higher in central UVCs, though they were used in a significant number of low-lying UVCs. Complications, while not statistically different, were three times higher in low-lying UVCs. CONCLUSION Despite conventional teaching, low-lying UVCs were used in nearly one-third of infants in this cohort. Parenteral nutrition, antibiotics, and vasopressors were infused through central and low-lying UVCs. There was no statistically significant difference in complication rates between UVC positions.
Collapse
Affiliation(s)
- Nathalie El Ters
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Colleen Claassen
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri
| | | | - Alan Barnette
- Department of Neonatology, Saint Francis Medical Center, Cape Girardeau, Missouri
| | - Whitney Eldridge
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Flora Yazigi
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Komalpreet Brar
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Maja Herco
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Lauren Rogowski
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Marya Strand
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Akshaya Vachharajani
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
15
|
McLauchlan DJ, Lancaster T, Craufurd D, Linden DEJ, Rosser AE. Insensitivity to loss predicts apathy in huntington's disease. Mov Disord 2019; 34:1381-1391. [PMID: 31361357 DOI: 10.1002/mds.27787] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/03/2019] [Accepted: 06/10/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Apathy is a deficit in goal-directed behavior that significantly affects quality of life and function. It is common in Huntington's disease and other disorders affecting corticostriatal pathways. Deficits in processing of reward, altered effort, and executive dysfunction are associated with apathy in other disorders, but the cognitive processes leading to apathy in Huntington's disease remain largely unknown. A previously reported deficit in learning from losses in Huntington's disease raises the possibility of a hitherto unrecognized mechanism leading to apathy. This study's objective was to delineate the cognitive processes associated with apathy in HD. METHODS We tested 51 Huntington's disease participants and 26 controls on a battery of novel and established measures to assess the contribution to apathy in Huntington's disease of executive function, reward value, reward-effort calculations, instrumental learning, and response to reward and loss. RESULTS Huntington's disase participants had deficits in instrumental learning with impaired response to loss, but no evidence to suggest altered reward-related behavior or effort. We also saw an executive dysfunction contribution to apathy in Huntington's disease. DISCUSSION We report the novel finding that apathy in Huntington's disease is associated with blunted responses to losses and impaired instrumental learning. This association is consistent with the known early degeneration of the indirect pathway and amygdala involvement in apathy in Huntington's disease, but is previously unreported in any disorder. In keeping with the comparative preservation of the ventral striatum and orbitofrontal cortex in Huntington's disease, reward valuation and reward-effort calculations did not contribute to apathy. © 2019 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Duncan J McLauchlan
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.,MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.,Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK
| | - Thomas Lancaster
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.,MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.,Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK
| | - David Craufurd
- Manchester Center for Genomic Medicine, Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Center, Manchester, UK.,St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Center, Manchester, UK
| | - David E J Linden
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.,MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.,Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK.,School for Mental Health and Neuroscience, Fac. Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Anne E Rosser
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.,MRC Center for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.,Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, UK
| |
Collapse
|
16
|
Huddart BM, Birch MT, Pratt FL, Blundell SJ, Porter DG, Clark SJ, Wu W, Julian SR, Hatton PD, Lancaster T. Local magnetism, magnetic order and spin freezing in the 'nonmetallic metal' FeCrAs. J Phys Condens Matter 2019; 31:285803. [PMID: 30933932 DOI: 10.1088/1361-648x/ab151f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present the results of x-ray scattering and muon-spin relaxation ([Formula: see text]SR) measurements on the iron-pnictide compound FeCrAs. Polarized non-resonant magnetic x-ray scattering results reveal the 120° periodicity expected from the suggested three-fold symmetric, non-collinear antiferromagnetic structure. [Formula: see text]SR measurements indicate a magnetically ordered phase throughout the bulk of the material below [Formula: see text] K. There are signs of fluctuating magnetism in a narrow range of temperatures above [Formula: see text] involving low-energy excitations, while at temperatures well below [Formula: see text] behaviour characteristic of freezing of dynamics is observed, likely reflecting the effect of disorder in our polycrystalline sample. Using density functional theory we propose a distinct muon stopping site in this compound and assess the degree of distortion induced by the implanted muon.
Collapse
Affiliation(s)
- B M Huddart
- Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Lancaster T. Profiling the international academic ghost writers who are providing low-cost essays and assignments for the contract cheating industry. JICES 2019. [DOI: 10.1108/jices-04-2018-0040] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose
Students have direct access to academic ghost writers who are able to provide for their assessment needs without the student needing to do any of the work. These ghost writers are helping to fuel the international industry of contract cheating, raising ethical dilemmas, but not much is known about the writers, their business or how they operate. This paper aims to explore how the ghost writers market their services and operate, based on observable information.
Design/methodology/approach
This paper reviews data from providers actively offering contract cheating services available to the public on Fiverr.com, a low-cost micro outsourcing site. The search term write essay is used to identify providers, finding 103 Gigs from 96 unique providers. Visible information, such as provider marketing, advertised services, pricing information and customer reviews, is analysed.
Findings
The results demonstrate that bespoke essays are readily available to students at a low cost. The majority of providers operate from Kenya. Revenue calculations indicate a price point of US$31.73 per 1,000 words, below the cost of traditional essay mills, but show that these 96 providers have generated around US$270,000 of essay writing business between them.
Originality/value
This study affords a look into a complex and established industry whose inner workings are normally kept private and for which little published information currently exists. The research adds to what is known about the extent, location and operation of the contract cheating industry.
Collapse
|
18
|
Liu J, Kittaka S, Johnson RD, Lancaster T, Singleton J, Sakakibara T, Kohama Y, van Tol J, Ardavan A, Williams BH, Blundell SJ, Manson ZE, Manson JL, Goddard PA. Unconventional Field-Induced Spin Gap in an S=1/2 Chiral Staggered Chain. Phys Rev Lett 2019; 122:057207. [PMID: 30822013 DOI: 10.1103/physrevlett.122.057207] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Indexed: 06/09/2023]
Abstract
We investigate the low-temperature magnetic properties of the molecule-based chiral spin chain [Cu(pym)(H_{2}O)_{4}]SiF_{6}·H_{2}O (pym=pyrimidine). Electron-spin resonance, magnetometry and heat capacity measurements reveal the presence of staggered g tensors, a rich low-temperature excitation spectrum, a staggered susceptibility, and a spin gap that opens on the application of a magnetic field. These phenomena are reminiscent of those previously observed in nonchiral staggered chains, which are explicable within the sine-Gordon quantum-field theory. In the present case, however, although the sine-Gordon model accounts well for the form of the temperature dependence of the heat capacity, the size of the gap and its measured linear field dependence do not fit with the sine-Gordon theory as it stands. We propose that the differences arise due to additional terms in the Hamiltonian resulting from the chiral structure of [Cu(pym)(H_{2}O)_{4}]SiF_{6}·H_{2}O, particularly a uniform Dzyaloshinskii-Moriya coupling and a fourfold periodic staggered field.
Collapse
Affiliation(s)
- J Liu
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S Kittaka
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - R D Johnson
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - T Lancaster
- Centre for Materials Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - J Singleton
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, MS-E536, Los Alamos, New Mexico 87545, USA
| | - T Sakakibara
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Y Kohama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - J van Tol
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - A Ardavan
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - B H Williams
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S J Blundell
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Z E Manson
- Department of Chemistry and Biochemistry, Eastern Washington University, Cheney, Washington 99004, USA
| | - J L Manson
- Department of Chemistry and Biochemistry, Eastern Washington University, Cheney, Washington 99004, USA
| | - P A Goddard
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| |
Collapse
|
19
|
Affiliation(s)
- R. Schoonmaker
- Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - T. Lancaster
- Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - S. J. Clark
- Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom
| |
Collapse
|
20
|
Bittner R, Hahn P, Novak C, Lancaster T, Linden D, Reif A. PB 22 Association between genetic risk for schizophrenia and deactivation of the right temporo-parietal junction during working memory encoding – An imaging genetics study. Clin Neurophysiol 2017. [DOI: 10.1016/j.clinph.2017.06.078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
21
|
Nadal R, Mortazavi A, Stein M, Pal S, Davarpanah N, Parnes H, Ning Y, Cordes L, Lin J, Bagheri M, Linderberg L, Berniger M, Steinberg S, Moore T, Lancaster T, Aviles M, Costello R, Bottaro D, Dahut W, Apolo A. Final results of a phase I study of cabozantinib (cabo) plus nivolumab (nivo) and cabonivo plus ipilimumab (Ipi) in patients (pts) with metastatic urothelial carcinoma (mUC) and other genitourinary (GU) malignancies. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx371.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
22
|
Foley SF, Tansey KE, Caseras X, Lancaster T, Bracht T, Parker G, Hall J, Williams J, Linden DE. Multimodal Brain Imaging Reveals Structural Differences in Alzheimer's Disease Polygenic Risk Carriers: A Study in Healthy Young Adults. Biol Psychiatry 2017; 81:154-161. [PMID: 27157680 PMCID: PMC5177726 DOI: 10.1016/j.biopsych.2016.02.033] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 02/08/2016] [Accepted: 02/29/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Recent genome-wide association studies have identified genetic loci that jointly make a considerable contribution to risk of developing Alzheimer's disease (AD). Because neuropathological features of AD can be present several decades before disease onset, we investigated whether effects of polygenic risk are detectable by neuroimaging in young adults. We hypothesized that higher polygenic risk scores (PRSs) for AD would be associated with reduced volume of the hippocampus and other limbic and paralimbic areas. We further hypothesized that AD PRSs would affect the microstructure of fiber tracts connecting the hippocampus with other brain areas. METHODS We analyzed the association between AD PRSs and brain imaging parameters using T1-weighted structural (n = 272) and diffusion-weighted scans (n = 197). RESULTS We found a significant association between AD PRSs and left hippocampal volume, with higher risk associated with lower left hippocampal volume (p = .001). This effect remained when the APOE gene was excluded (p = .031), suggesting that the relationship between hippocampal volume and AD is the result of multiple genetic factors and not exclusively variability in the APOE gene. The diffusion tensor imaging analysis revealed that fractional anisotropy of the right cingulum was inversely correlated with AD PRSs (p = .009). We thus show that polygenic effects of AD risk variants on brain structure can already be detected in young adults. CONCLUSIONS This finding paves the way for further investigation of the effects of AD risk variants and may become useful for efforts to combine genotypic and phenotypic data for risk prediction and to enrich future prevention trials of AD.
Collapse
Affiliation(s)
- Sonya F. Foley
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom,Central Biotechnology Services, TIME Institute, Wales, United Kingdom,Address correspondence to Sonya F. Foley, M.Sc., Cardiff University Brain Research Imaging Centre, 70 Park Place, Cardiff CF103AT, United Kingdom;Cardiff University Brain Research Imaging Centre, 70 Park PlaceCardiffCF103ATUnited Kingdom
| | - Katherine E. Tansey
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Medical Research Council Integrative Epidemiology Unit, School of Social and Community Medicine, Faculty of Medicine & Dentistry, University of Bristol, Bristol, United Kingdom
| | - Xavier Caseras
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom
| | - Thomas Lancaster
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom
| | - Tobias Bracht
- Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom
| | - Greg Parker
- Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom
| | - Jeremy Hall
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Neuroscience and Mental Health Research Institute, Wales, United Kingdom
| | - Julie Williams
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom
| | - David E.J. Linden
- Cardiff University Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Wales, United Kingdom,Cardiff University Brain Research Imaging Centre, School of Psychology, Wales, United Kingdom
| |
Collapse
|
23
|
Apolo A, Mortazavi A, Stein M, Pal S, Davarpanah N, Parnes H, Ning Y, Francis D, Cordes L, Berniger M, Steinberg S, Monk P, Lancaster T, Mayer T, Costello R, Bottaro D, Dahut W. A phase I study of cabozantinib plus nivolumab (CaboNivo) in patients (pts) refractory metastatic urothelial carcinoma (mUC) and other genitourinary (GU) tumors. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw373.02] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
24
|
Williams RC, Xiao F, Thomas IO, Clark SJ, Lancaster T, Cornish GA, Blundell SJ, Hayes W, Paul AK, Felser C, Jansen M. Muon-spin relaxation study of the double perovskite insulators Sr2 BOsO6 (B = Fe, Y, ln). J Phys Condens Matter 2016; 28:076001. [PMID: 26807612 DOI: 10.1088/0953-8984/28/7/076001] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present the results of zero-field muon-spin relaxation measurements made on the double perovskite insulators Sr2 BOsO6 (B = Fe,Y, In). Spontaneous muon-spin precession indicative of quasistatic long range magnetic ordering is observed in Sr2FeOsO6 within the AF1 antiferromagnetic phase for temperatures below [Formula: see text] K. Upon cooling below T2≈67 K the oscillations cease to be resolvable owing to the coexistence of the AF1 and AF2 phases, which leads to a broader range of internal magnetic fields. Using density functional calculations we identify a candidate muon stopping site within the unit cell, which dipole field simulations show to be consistent with the proposed magnetic structure. The possibility of incommensurate magnetic ordering is discussed for temperatures below TN = 53 K and 25 K for Sr2YOsO6 and Sr2InOsO6, respectively.
Collapse
Affiliation(s)
- R C Williams
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Simpson K, Miller J, Lancaster T, Henn M, Epstein D, Schuessler R, Balzer D, Shahanavaz S, Murphy J, Eghtesady P, Boston U, Canter C. Improved Transplant Survival in Failed Fontan Patients With Preserved Ventricular Function in the Current Era. J Heart Lung Transplant 2015. [DOI: 10.1016/j.healun.2015.01.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
26
|
Foronda FR, Lang F, Möller JS, Lancaster T, Boothroyd AT, Pratt FL, Giblin SR, Prabhakaran D, Blundell SJ. Anisotropic local modification of crystal field levels in Pr-based pyrochlores: a muon-induced effect modeled using density functional theory. Phys Rev Lett 2015; 114:017602. [PMID: 25615502 DOI: 10.1103/physrevlett.114.017602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Indexed: 06/04/2023]
Abstract
Although muon spin relaxation is commonly used to probe local magnetic order, spin freezing, and spin dynamics, we identify an experimental situation in which the measured response is dominated by an effect resulting from the muon-induced local distortion rather than the intrinsic behavior of the host compound. We demonstrate this effect in some quantum spin ice candidate materials Pr(2)B(2)O(7) (B=Sn, Zr, Hf), where we detect a static distribution of magnetic moments that appears to grow on cooling. Using density functional theory we show how this effect can be explained via a hyperfine enhancement arising from a splitting of the non-Kramers doublet ground states on Pr ions close to the muon, which itself causes a highly anisotropic distortion field. We provide a quantitative relationship between this effect and the measured temperature dependence of the muon relaxation and discuss the relevance of these observations to muon experiments in other magnetic materials.
Collapse
Affiliation(s)
- F R Foronda
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - F Lang
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J S Möller
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - T Lancaster
- Durham University, Centre for Materials Physics, South Road, Durham DH1 3LE, United Kingdom
| | - A T Boothroyd
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - F L Pratt
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - S R Giblin
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, United Kingdom
| | - D Prabhakaran
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S J Blundell
- Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| |
Collapse
|
27
|
Erk S, Meyer-Lindenberg A, Linden DE, Lancaster T, Mohnke S, Grimm O, Degenhardt F, Holmans P, Pocklington A, Schmierer P, Haddad L, Mühleisen TW, Mattheisen M, Witt SH, Romanczuk-Seiferth N, Tost H, Schott BH, Cichon S, Nöthen MM, Rietschel M, Heinz A, Walter H. Replication of brain function effects of a genome-wide supported psychiatric risk variant in the CACNA1C gene and new multi-locus effects. Neuroimage 2014; 94:147-154. [DOI: 10.1016/j.neuroimage.2014.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/09/2014] [Accepted: 03/09/2014] [Indexed: 12/12/2022] Open
|
28
|
Pratt FL, Lancaster T, Blundell SJ, Baines C. Low-field superconducting phase of (TMTSF)2ClO4. Phys Rev Lett 2013; 110:107005. [PMID: 23521285 DOI: 10.1103/physrevlett.110.107005] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 01/04/2013] [Indexed: 06/01/2023]
Abstract
The low-field phase of the organic superconductor (TMTSF)(2)ClO(4) is studied by muon-spin rotation. The zero temperature limit of the magnetic penetration depth within the TMTSF layers is obtained to be λ(ab)(0) = 0.86(2) μm. Temperature dependence of the muon-spin relaxation shows no indication of gap nodes on the Fermi surface nor of any spontaneous fields due to time-reversal-symmetry breaking. The weight of evidence suggests that the symmetry of this low-field phase is odd-frequency p-wave singlet, a novel example of odd-frequency pairing in a bulk superconductor.
Collapse
Affiliation(s)
- F L Pratt
- ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | | | | | | |
Collapse
|
29
|
Choi SK, Coldea R, Kolmogorov AN, Lancaster T, Mazin II, Blundell SJ, Radaelli PG, Singh Y, Gegenwart P, Choi KR, Cheong SW, Baker PJ, Stock C, Taylor J. Spin waves and revised crystal structure of honeycomb iridate Na2IrO3. Phys Rev Lett 2012; 108:127204. [PMID: 22540621 DOI: 10.1103/physrevlett.108.127204] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Indexed: 05/31/2023]
Abstract
We report inelastic neutron scattering measurements on Na2IrO3, a candidate for the Kitaev spin model on the honeycomb lattice. We observe spin-wave excitations below 5 meV with a dispersion that can be accounted for by including substantial further-neighbor exchanges that stabilize zigzag magnetic order. The onset of long-range magnetic order below T(N)=15.3 K is confirmed via the observation of oscillations in zero-field muon-spin rotation experiments. Combining single-crystal diffraction and density functional calculations we propose a revised crystal structure model with significant departures from the ideal 90° Ir-O-Ir bonds required for dominant Kitaev exchange.
Collapse
Affiliation(s)
- S K Choi
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Lord JS, McKenzie I, Baker PJ, Blundell SJ, Cottrell SP, Giblin SR, Good J, Hillier AD, Holsman BH, King PJC, Lancaster T, Mitchell R, Nightingale JB, Owczarkowski M, Poli S, Pratt FL, Rhodes NJ, Scheuermann R, Salman Z. Design and commissioning of a high magnetic field muon spin relaxation spectrometer at the ISIS pulsed neutron and muon source. Rev Sci Instrum 2011; 82:073904. [PMID: 21806196 DOI: 10.1063/1.3608114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The high magnetic field (HiFi) muon instrument at the ISIS pulsed neutron and muon source is a state-of-the-art spectrometer designed to provide applied magnetic fields up to 5 T for muon studies of condensed matter and molecular systems. The spectrometer is optimised for time-differential muon spin relaxation studies at a pulsed muon source. We describe the challenges involved in its design and construction, detailing, in particular, the magnet and detector performance. Commissioning experiments have been conducted and the results are presented to demonstrate the scientific capabilities of the new instrument.
Collapse
Affiliation(s)
- J S Lord
- ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Lancaster T, Möller JS, Blundell SJ, Pratt FL, Baker PJ, Guidi T, Timco GA, Winpenny REP. Observation of a level crossing in a molecular nanomagnet using implanted muons. J Phys Condens Matter 2011; 23:242201. [PMID: 21628784 DOI: 10.1088/0953-8984/23/24/242201] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have observed an electronic energy level crossing in a molecular nanomagnet (MNM) using muon spin relaxation. This effect, not observed previously despite several muon studies of MNM systems, provides further evidence that the spin relaxation of the implanted muon is sensitive to the dynamics of the electronic spin. Our measurements on a broken ring MNM [H(2)N(t)Bu(is)Pr][Cr(8)CdF(9)(O(2)CC(CH(3))(3))(18)], which contains eight Cr ions, show clear evidence for the S = 0 --> S = 1 transition that takes place at B(c) = 2.3 T. The crossing is observed as a resonance-like dip in the average positron asymmetry and also in the muon spin relaxation rate, which shows a sharp increase in magnitude at the transition and a peak centred within the S = 1 regime.
Collapse
Affiliation(s)
- T Lancaster
- Clarendon Laboratory, Oxford University Department of Physics, Oxford, UK.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Linden D, Lancaster T. Functional Magnetic Resonance Imaging (FMRI)-based neurofeedback as a new treatment tool for depression. Eur Psychiatry 2011. [DOI: 10.1016/s0924-9338(11)72642-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We investigated whether depressed patients who received fMRI-based neurofeedback are able to upregulate the activity in brain areas devoted to positive emotion processing and thereby establish improvements in mood state. Eight medicated patients with major depression participated in four separate fMRI sessions, each of which consisted of an emotion localiser and three neurofeedback runs. Target areas were selected individually with a functional localiser that identified the region most responsive to positive affective images. The target areas were in uni- or bilateral prefrontal cortex, insula or amygdala. During neurofeedback runs, patients received real-time feedback about activation levels in the target area. Each patient learnt to increase target area activity over successive sessions. Depression scores on the 17-item Hamilton Depression Rating Scale improved significantly. No such improvement was seen in a non-neurofeedback control group (N = 8) that was matched for symptom severity, demographics and medication and used the same cognitive/affective strategies that were employed successfully by the neurofeedback group, but outside the scanner. This group difference in treatment effects was supported by a significant interaction between the factors time (pre/post-intervention) and group (neurofeedback/controls) on the repeated measures ANOVA (F(1,14) = 10.15, p = .007). The neurofeedback group showed increasing activity in the ventral striatum and regions involved in cognitive control as training progressed. Upregulation of brain areas responsive to positive affective cues through fMRI-neurofeedback is thus a promising tool in the treatment of depression. The novelty of the present approach consists in the combination of biological and cognitive factors in the same intervention.
Collapse
|
33
|
Abstract
Total absence of ribs is a rare finding that has occasionally been documented in patients with cerebrocostomandibular syndrome. Only 2 other reports document complete absence of ribs in 3 individuals, and we tabulate the findings of all the 4 cases of complete absence of ribs in this case report. Our case and the other 3 reported cases represent the extreme form of cerebrocostomandibular syndrome with regard to the costal defects.
Collapse
Affiliation(s)
- Seema Lale
- Department of Pathology, Truman Medical Center, Kansas City, MO 64108, USA
| | | | | | | | | | | |
Collapse
|
34
|
Lancaster T, Pratt FL, Blundell SJ, McKenzie I, Assender HE. Muon-fluorine entanglement in fluoropolymers. J Phys Condens Matter 2009; 21:346004. [PMID: 21715794 DOI: 10.1088/0953-8984/21/34/346004] [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] [Indexed: 05/31/2023]
Abstract
We present the results of muon spin relaxation measurements on the fluoropolymers polytetrafluoroethylene (PTFE), poly(vinylidene fluoride) (PVDF) and poly(vinyl fluoride) (PVF). Entanglement between the muon spin and the spins of the fluorine nuclei in the polymers allows us to identify the different muon stopping states that occur in each of these materials and provides a method of probing the local environment of the muon and the dynamics of the polymer chains.
Collapse
Affiliation(s)
- T Lancaster
- Department of Physics, Clarendon Laboratory, Oxford University, Parks Road, Oxford OX1 3PU, UK
| | | | | | | | | |
Collapse
|
35
|
Lawrence M, Jones L, Lancaster T, Daly E, Banks E. Hormone replacement therapy: patterns of use studied through British general practice computerized records. Climacteric 2009. [DOI: 10.3109/13697139909038096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
36
|
Drew AJ, Niedermayer C, Baker PJ, Pratt FL, Blundell SJ, Lancaster T, Liu RH, Wu G, Chen XH, Watanabe I, Malik VK, Dubroka A, Rössle M, Kim KW, Baines C, Bernhard C. Coexistence of static magnetism and superconductivity in SmFeAsO(1-x)F(x) as revealed by muon spin rotation. Nat Mater 2009; 8:310-314. [PMID: 19234446 DOI: 10.1038/nmat2396] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 01/20/2009] [Indexed: 05/27/2023]
Abstract
The recent observation of superconductivity with critical temperatures (Tc) up to 55 K in the pnictide RFeAsO(1-x)F(x), where R is a lanthanide, marks the first discovery of a non-copper-oxide-based layered high-Tc superconductor. It has raised the suspicion that these new materials share a similar pairing mechanism to the cuprate superconductors, as both families exhibit superconductivity following charge doping of a magnetic parent material. In this context, it is important to follow the evolution of the microscopic magnetic properties of the pnictides with doping and hence to determine whether magnetic correlations coexist with superconductivity. Here, we present a muon spin rotation study on SmFeAsO(1-x)F(x), with x=0-0.30 that shows that, as in the cuprates, static magnetism persists well into the superconducting regime. This analogy is quite surprising as the parent compounds of the two families have rather different magnetic ground states: itinerant spin density wave for the pnictides contrasted with the Mott-Hubbard insulator in the cuprates. Our findings therefore suggest that the proximity to magnetic order and associated soft magnetic fluctuations, rather than strong electronic correlations in the vicinity of a Mott-Hubbard transition, may be the key ingredients of high-Tc superconductors.
Collapse
Affiliation(s)
- A J Drew
- University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Chemin du Musée 3, CH-1700 Fribourg, Switzerland.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Baker PJ, Lancaster T, Blundell SJ, Pratt FL, Brooks ML, Kwon SJ. Tuning the interlayer spacing of high-T_{c} Bi-based superconductors by intercalation: measuring the penetration depth and the two-dimensional superfluid density. Phys Rev Lett 2009; 102:087002. [PMID: 19257777 DOI: 10.1103/physrevlett.102.087002] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Indexed: 05/27/2023]
Abstract
Substantial control of the interlayer spacing in Bi-based high temperature superconductors has been achieved through the intercalation of guest molecules between the superconducting layers. Measurements using implanted muons reveal that the penetration depth increases with increasing layer separation while T_{c} does not vary appreciably, demonstrating that the bulk superfluid density is not the determining factor controlling T_{c}. Our results strongly suggest that for Bi-based high temperature superconductors the superfluid density appearing in the Uemura scaling relation rho_{s} proportional, variantT_{c} should be interpreted as the two-dimensional density within the superconducting layers, which we find to be constant for each class of system investigated.
Collapse
Affiliation(s)
- P J Baker
- Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom
| | | | | | | | | | | |
Collapse
|
38
|
Lancaster T. Physician training in the use of a decision aid increased patient participation in decision making for CVD prevention. ACTA ACUST UNITED AC 2009; 14:24. [DOI: 10.1136/ebm.14.1.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
39
|
Baker PJ, Lancaster T, Blundell SJ, Hayes W, Pratt FL, Itoh M, Kuroiwa S, Akimitsu J. Muon spin relaxation study of LaTiO(3) and YTiO(3). J Phys Condens Matter 2008; 20:465203. [PMID: 21693843 DOI: 10.1088/0953-8984/20/46/465203] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report muon spin relaxation (μSR) measurements on two Ti(3+) containing perovskites, LaTiO(3) and YTiO(3), which display long-range magnetic order at low temperature. For both materials, oscillations in the time dependence of the muon polarization are observed which are consistent with three-dimensional magnetic order. From our data we identify two magnetically inequivalent muon stopping sites. The μSR results are compared with the magnetic structures of these compounds previously derived from neutron diffraction and μSR studies on structurally similar compounds.
Collapse
Affiliation(s)
- P J Baker
- Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU, UK
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Drew AJ, Pratt FL, Lancaster T, Blundell SJ, Baker PJ, Liu RH, Wu G, Chen XH, Watanabe I, Malik VK, Dubroka A, Kim KW, Rössle M, Bernhard C. Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation. Phys Rev Lett 2008; 101:097010. [PMID: 18851648 DOI: 10.1103/physrevlett.101.097010] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Indexed: 05/26/2023]
Abstract
Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An estimate of the in-plane penetration depth lambda ab(0)=190(5) nm was obtained, which confirms that the pnictide superconductors obey an Uemura-style relationship between Tc and lambda ab(0);(-2).
Collapse
Affiliation(s)
- A J Drew
- Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musee 3, CH-1700 Fribourg, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
BACKGROUND Healthcare professionals frequently advise patients to improve their health by stopping smoking. Such advice may be brief, or part of more intensive interventions. OBJECTIVES The aims of this review were to assess the effectiveness of advice from physicians in promoting smoking cessation; to compare minimal interventions by physicians with more intensive interventions; to assess the effectiveness of various aids to advice in promoting smoking cessation, and to determine the effect of anti-smoking advice on disease-specific and all-cause mortality. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group trials register. Date of the most recent search: September 2007. SELECTION CRITERIA Randomized trials of smoking cessation advice from a medical practitioner in which abstinence was assessed at least six months after advice was first provided. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on the setting in which advice was given, type of advice given (minimal or intensive), and whether aids to advice were used, the outcome measures, method of randomization and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up. We also considered the effect of advice on mortality where long-term follow-up data were available. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow up were counted as smokers. Effects were expressed as relative risks. Where possible, meta-analysis was performed using a Mantel-Haenszel fixed effect model. MAIN RESULTS We identified 41 trials, conducted between 1972 and 2007, including over 31,000 smokers. In some trials, subjects were at risk of specified diseases (chest disease, diabetes, ischaemic heart disease), but most were from unselected populations. The most common setting for delivery of advice was primary care. Other settings included hospital wards and outpatient clinics, and industrial clinics. Pooled data from 17 trials of brief advice versus no advice (or usual care) detected a significant increase in the rate of quitting (relative risk (RR) 1.66, 95% confidence interval (CI) 1.42 to 1.94). Amongst 11 trials where the intervention was judged to be more intensive the estimated effect was higher (RR 1.84, 95% CI 1.60 to 2.13) but there was no statistical difference between the intensive and minimal subgroups. Direct comparison of intensive versus minimal advice showed a small advantage of intensive advice (RR 1.37, 95% CI 1.20 to 1.56). Direct comparison also suggested a small benefit of follow-up visits. Only one study determined the effect of smoking advice on mortality. This study found no statistically significant differences in death rates at 20 years follow up. AUTHORS' CONCLUSIONS Simple advice has a small effect on cessation rates. Assuming an unassisted quit rate of 2 to 3%, a brief advice intervention can increase quitting by a further 1 to 3%. Additional components appear to have only a small effect, though there is a small additional benefit of more intensive interventions compared to very brief interventions.
Collapse
Affiliation(s)
- L F Stead
- University of Oxford, Department of Primary Health Care, Old Road Campus, Headington, Oxford, UK OX3 7LF.
| | | | | |
Collapse
|
42
|
Abstract
BACKGROUND The aim of nicotine replacement therapy (NRT) is temporarily to replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence. OBJECTIVES The aims of this review were:To determine the effect of NRT compared to placebo in aiding smoking cessation, and to consider whether there is a difference in effect for the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets/lozenges) in achieving abstinence from cigarettes. To determine whether the effect is influenced by the dosage, form and timing of use of NRT; the intensity of additional advice and support offered to the smoker; or the clinical setting in which the smoker is recruited and treated. To determine whether combinations of NRT are more likely to lead to successful quitting than one type alone. To determine whether NRT is more or less likely to lead to successful quitting compared to other pharmacotherapies. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group trials register for papers with 'nicotine' or 'NRT' in the title, abstract or keywords. Date of most recent search July 2007. SELECTION CRITERIA Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow up of less than six months. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model. MAIN RESULTS We identified 132 trials; 111 with over 40,000 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The RR of abstinence for any form of NRT relative to control was 1.58 (95% confidence interval [CI]: 1.50 to 1.66). The pooled RR for each type were 1.43 (95% CI: 1.33 to 1.53, 53 trials) for nicotine gum; 1.66 (95% CI: 1.53 to 1.81, 41 trials) for nicotine patch; 1.90 (95% CI: 1.36 to 2.67, 4 trials) for nicotine inhaler; 2.00 (95% CI: 1.63 to 2.45, 6 trials) for oral tablets/lozenges; and 2.02 (95% CI: 1.49 to 3.73, 4 trials) for nicotine nasal spray. The effects were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. The effect was similar in a small group of studies that aimed to assess use of NRT obtained without a prescription. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum, but weaker evidence of a benefit from higher doses of patch. There was evidence that combining a nicotine patch with a rapid delivery form of NRT was more effective than a single type of NRT. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with nicotine patch were lower than with the antidepressant bupropion. AUTHORS' CONCLUSIONS All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50-70%, regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.
Collapse
Affiliation(s)
- L F Stead
- University of Oxford, Department of Primary Health Care, Old Road Campus, Headington, Oxford, UK OX3 7LF.
| | | | | | | | | |
Collapse
|
43
|
Lancaster T, Blundell SJ, Baker PJ, Brooks ML, Hayes W, Pratt FL, Coldea R, Sörgel T, Jansen M. Anomalous temperature evolution of the internal magnetic field distribution in the charge-ordered triangular antiferromagnet AgNiO2. Phys Rev Lett 2008; 100:017206. [PMID: 18232815 DOI: 10.1103/physrevlett.100.017206] [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: 08/02/2007] [Indexed: 05/25/2023]
Abstract
Zero-field muon-spin relaxation measurements of the frustrated triangular quantum magnet AgNiO2 are consistent with a model of charge disproportionation that has been advanced to explain the structural and magnetic properties of this compound. Below an ordering temperature of TN=19.9(2) K we observe six distinct muon precession frequencies, due to the magnetic order, which can be accounted for with a model describing the probable muon sites. The precession frequencies show an unusual temperature evolution which is suggestive of the separate evolution of two opposing magnetic sublattices.
Collapse
Affiliation(s)
- T Lancaster
- Clarendon Laboratory, Oxford University Department of Physics, Parks Road, Oxford OX1 3PU, United Kingdom.
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Lancaster T, Blundell SJ, Baker PJ, Brooks ML, Hayes W, Pratt FL, Manson JL, Conner MM, Schlueter JA. Muon-fluorine entangled states in molecular magnets. Phys Rev Lett 2007; 99:267601. [PMID: 18233603 DOI: 10.1103/physrevlett.99.267601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Indexed: 05/25/2023]
Abstract
The information accessible from a muon-spin relaxation experiment can be limited due to a lack of knowledge of the precise muon stopping site. We demonstrate here the possibility of localizing a spin polarized muon in a known stopping state in a molecular material containing fluorine. The muon-spin precession that results from the entangled nature of the muon spin and surrounding nuclear spins is sensitive to the nature of the stopping site. We use this property to identify three classes of sites that occur in molecular magnets and describe the extent to which the muon distorts its surroundings.
Collapse
Affiliation(s)
- T Lancaster
- Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford, OX1 3PU, United Kingdom.
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
BACKGROUND It may be reasonable to try to reduce the harm from continued smoking amongst smokers unable or unwilling to quit. Possible approaches to reduce the exposure to toxins from smoking include reducing the amount of tobacco used, and using less toxic products. The interventions evaluated in controlled trials have predominantly attempted to reduce the number of cigarettes smoked. OBJECTIVES To assess the effect of interventions intended to reduce the harm from smoking on the following: biomarkers of damage caused by tobacco, biomarkers of tobacco exposure, number of cigarettes smoked, quitting, and long-term health status. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group Specialised Register using free text and MeSH terms for harm reduction, smoking reduction and cigarette reduction. The initial search was in March 2006, updated in March 2007. SELECTION CRITERIA Randomized or quasi-randomized controlled trials of interventions in tobacco users to reduce amount smoked, or to reduce harm from smoking by means other than cessation. Outcomes were change in cigarette consumption, markers of cigarette exposure and any markers of damage or benefit to health, measured at least six months from the start of the intervention. DATA COLLECTION AND ANALYSIS We pooled trials with similar interventions and outcomes using a fixed-effect model. Other studies were summarised narratively. MAIN RESULTS The 13 included trials all evaluated interventions to help smokers cut down the amount smoked. Self-reported reduction in cigarettes per day (CPD) was validated by reduction in carbon monoxide (CO) levels. Most trials tested nicotine replacement therapy (NRT) to assist reduction. No eligible studies evaluated the use of potentially reduced-exposure products. In a pooled analysis of eight trials, NRT significantly increased the odds of reducing CPD by 50% or more for people using nicotine gum or inhaler or a choice of product compared to placebo (n=3273, odds ratio [OR] 2.02, 95% confidence interval [CI] 1.55 to 2.62). Where average changes from baseline were compared for different measures, CO and cotinine consistently showed smaller reductions than CPD. Whilst the effect for NRT was significant, small numbers of people in either treatment or control group successfully sustained a reduction of 50% or more. Use of NRT also significantly increased the odds of quitting (OR 1.90, 95% CI 1.46 to 2.47). One trial of bupropion failed to detect an effect on reduction or cessation. Four trials of different types of advice and instructions on reducing CPD did not provide clear evidence. AUTHORS' CONCLUSIONS There is insufficient evidence about long-term benefit to give firm support the use of interventions intended to help smokers reduce but not quit tobacco use. Some people who do not wish to quit can be helped to cut down the number of cigarettes smoked and reduce their carbon monoxide levels by using nicotine gum or nicotine inhaler. Because the long-term health benefit of a reduction in smoking rate is unclear this application of NRT is more appropriately used as a precursor to quitting.
Collapse
Affiliation(s)
- L F Stead
- Oxford University, Department of Primary Health Care, Old Road Campus, Headington, Oxford, UK, OX3 7LF.
| | | |
Collapse
|
46
|
Pratt FL, Baker PJ, Blundell SJ, Lancaster T, Green MA, Kurmoo M. Chiral-like critical behavior in the antiferromagnet cobalt glycerolate. Phys Rev Lett 2007; 99:017202. [PMID: 17678186 DOI: 10.1103/physrevlett.99.017202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Indexed: 05/16/2023]
Abstract
Critical exponents closely matching those of the N=2 chiral universality class have been obtained for the layered magnetic system cobalt glycerolate using muon spin relaxation. This class was originally introduced to represent geometrically frustrated triangular stacked-layer XY magnets with chiral noncollinear spin structures. Since the present magnetic system is a canted XY system without geometrical frustration or chiral degeneracy, the results indicate that the order parameter for canting in this system plays a similar role to the chiral order parameter in the geometrically frustrated systems, strongly suggesting that both types of noncollinear system share the same universality class.
Collapse
Affiliation(s)
- F L Pratt
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire, United Kingdom
| | | | | | | | | | | |
Collapse
|
47
|
Lancaster T, Blundell SJ, Andreica D, Janoschek M, Roessli B, Gvasaliya SN, Conder K, Pomjakushina E, Brooks ML, Baker PJ, Prabhakaran D, Hayes W, Pratt FL. Magnetism in geometrically frustrated YMnO3 under hydrostatic pressure studied with muon spin relaxation. Phys Rev Lett 2007; 98:197203. [PMID: 17677657 DOI: 10.1103/physrevlett.98.197203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Indexed: 05/16/2023]
Abstract
The ferroelectromagnet YMnO3 consists of weakly coupled triangular layers of S=2 spins. Below T(N) approximately equal to 70 K muon-spin relaxation data show two oscillatory relaxing signals due to magnetic order, with no purely relaxing signals resolvable (which would require different coexisting spin distributions). The transition temperature T(N) increases with applied hydrostatic pressure, even though the ordered moment decreases. These results suggest that pressure increases both the exchange coupling between the layers and the frustration within the layers.
Collapse
Affiliation(s)
- T Lancaster
- Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford, OX1 3PU, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
BACKGROUND There are at least two theoretical reasons to believe antidepressants might help in smoking cessation. Nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Alternatively, some antidepressants may have a specific effect on neural pathways underlying nicotine addiction, (e.g. blocking nicotine receptors) independent of their antidepressant effects. OBJECTIVES The aim of this review is to assess the effect of antidepressant medications in aiding long-term smoking cessation. The medications include bupropion; doxepin; fluoxetine; imipramine; moclobemide; nortriptyline; paroxetine; sertraline, tryptophan and venlafaxine. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, and other reviews and meeting abstracts, in September 2006. SELECTION CRITERIA We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or to help smokers reduce cigarette consumption. We excluded trials with less than six months follow up. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on the type of study population, the nature of the pharmacotherapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up in patients smoking at baseline, expressed as an odds ratio (OR). We used the most rigorous definition of abstinence available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model. MAIN RESULTS Seventeen new trials were identified since the last update in 2004 bringing the total number of included trials to 53. There were 40 trials of bupropion and eight trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (31 trials, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.72 to 2.19) and nortriptyline (four trials, OR 2.34, 95% CI 1.61 to 3.41) both doubled the odds of cessation. There is insufficient evidence that adding bupropion or nortriptyline to nicotine replacement therapy provides an additional long-term benefit. Three trials of extended therapy with bupropion to prevent relapse after initial cessation did not find evidence of a significant long-term benefit. From the available data bupropion and nortriptyline appear to be equally effective and of similar efficacy to nicotine replacement therapy. Pooling three trials comparing bupropion to varenicline showed a lower odds of quitting with bupropion (OR 0.60, 95% CI 0.46 to 0.78). There is a risk of about 1 in 1000 of seizures associated with bupropion use. Concerns that bupropion may increase suicide risk are currently unproven. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation. There were six trials of selective serotonin reuptake inhibitors; four of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant long-term effects, and there was no evidence of a significant benefit when results were pooled. There was one trial of the monoamine oxidase inhibitor moclobemide, and one of the atypical antidepressant venlafaxine. Neither of these detected a significant long-term benefit. AUTHORS' CONCLUSIONS The antidepressants bupropion and nortriptyline aid long-term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Adverse events with both medications are rarely serious or lead to stopping medication.
Collapse
Affiliation(s)
- J R Hughes
- University of Vermont, Department of Psychiatry, 38 Fletcher Place, Burlington, Vermont 05401-1419, USA.
| | | | | |
Collapse
|
49
|
Abstract
BACKGROUND Nicotine receptor partial agonists may help smokers to quit by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials are underway. OBJECTIVES The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The last search was in October 2006. SELECTION CRITERIA We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up. The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis using the Mantel-Haenszel fixed-effect model. MAIN RESULTS We found five trials of varenicline compared with placebo for smoking cessation; three of these also included a bupropion experimental arm. We also found one relapse prevention trial, comparing varenicline with placebo. The six trials covered 4924 participants, 2451 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion. The pooled odds ratio (OR) for continuous abstinence at 12 months for varenicline versus placebo was 3.22 (95% confidence interval [CI] 2.43 to 4.27). The pooled OR for varenicline versus bupropion was 1.66 (95% CI 1.28 to 2.16). The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated and effective during long-term use. The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an OR of 1.77 (95% CI 1.30 to 2.40). AUTHORS' CONCLUSIONS Varenicline increased the odds of successful long-term smoking cessation approximately threefold compared with pharmacologically unassisted quit attempts. In trials reported so far, more participants quit successfully with varenicline than with bupropion. The effectiveness of varenicline as an aid to relapse prevention has not been clearly established. The main adverse effect of varenciline is nausea, but this is mostly at mild to moderate levels and tends to reduce with habituation. There is a need for independent trials of varenicline versus placebo, to test the early findings. There is also a need for direct comparisons with nicotine replacement therapy, and for further trials with bupropion, to establish the relative efficacy of the treatments.Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive.
Collapse
Affiliation(s)
- K Cahill
- Department of Primary Health Care, Old Road Campus, University of Oxford, Oxford, UK, OX3 7LF.
| | | | | |
Collapse
|
50
|
Abstract
BACKGROUND There are at least two theoretical reasons to believe antidepressants might help in smoking cessation. Nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Alternatively, some antidepressants may have a specific effect on neural pathways underlying nicotine addiction, (e.g. blocking nicotine receptors) independent of their antidepressant effects. OBJECTIVES The aim of this review is to assess the effect of antidepressant medications in aiding long-term smoking cessation. The medications include bupropion; doxepin; fluoxetine; imipramine; moclobemide; nortriptyline; paroxetine; sertraline, tryptophan and venlafaxine. SEARCH STRATEGY We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, and other reviews and meeting abstracts, in September 2006. SELECTION CRITERIA We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or to help smokers reduce cigarette consumption. We excluded trials with less than six months follow up. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on the type of study population, the nature of the pharmacotherapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up in patients smoking at baseline, expressed as an odds ratio (OR). We used the most rigorous definition of abstinence available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model. MAIN RESULTS Seventeen new trials were identified since the last update in 2004 bringing the total number of included trials to 53. There were 40 trials of bupropion and eight trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (31 trials, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.72 to 2.19) and nortriptyline (four trials, OR 2.34, 95% CI 1.61 to 3.41) both doubled the odds of cessation. There is insufficient evidence that adding bupropion or nortriptyline to nicotine replacement therapy provides an additional long-term benefit. Three trials of extended therapy with bupropion to prevent relapse after initial cessation did not find evidence of a significant long-term benefit. From the available data bupropion and nortriptyline appear to be equally effective and of similar efficacy to nicotine replacement therapy. Pooling three trials comparing bupropion to varenicline showed a lower odds of quitting with bupropion (OR 0.60, 95% CI 0.46 to 0.78). There is a risk of about 1 in 1000 of seizures associated with bupropion use. Concerns that bupropion may increase suicide risk are currently unproven. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation. There were six trials of selective serotonin reuptake inhibitors; four of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant long-term effects, and there was no evidence of a significant benefit when results were pooled. There was one trial of the monoamine oxidase inhibitor moclobemide, and one of the atypical antidepressant venlafaxine. Neither of these detected a significant long-term benefit. AUTHORS' CONCLUSIONS The antidepressants bupropion and nortriptyline aid long-term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Adverse events with both medications are rarely serious or lead to stopping medication.
Collapse
Affiliation(s)
- J R Hughes
- University of Vermont, Department of Psychiatry, 38 Fletcher Place, Burlington, Vermont 05401-1419, USA.
| | | | | |
Collapse
|