Running couplings for the simultaneous decoupling of heavy quarks

Scale-invariant running couplings are constructed for several quarks being decoupled together, without reference to intermediate thresholds. Large-momentum scales can also be included. The result is a multi-scale generalization of the renormalization group applicable to any order. Inconsistencies in the usual decoupling procedure with a single running coupling can then be avoided, e.g. when cancelling anomalous corrections from t,b quarks to the axial charge of the proton.Comment: 12 pages, 1 figure, version to appear in PLB. Pages 8-11 and Fig. 1 are new, with consequent changes to the abstract, page 2, and the references. We show that our multi-scale renormalization group is needed to achieve anomaly cancellation in t,b decoupling from the weak neutral current, and extend it to include large moment

Breaking Down Grit: Persistency and Flexibility in the Career Plans of Military Medical Students.

INTRODUCTION: The field of medicine is experiencing a crisis as high levels of physician and trainee burnout threaten the pipeline of future physicians. Grit, or passion and perseverance for long-term goals, has been studied in high-performing and elite military units and found to be predictive of successful completion of training in adverse conditions. The Uniformed Services University of the Health Sciences (USU) graduates military medical leaders who make up a significant portion of the Military Health System physician workforce. Taken together, an improved understanding of the relationships between burnout, well-being, grit, and retention among USU graduates is critical to the success of the Military Health System. MATERIALS AND METHODS: The current study was approved by the Institutional Review Board at USU and explored these relations among 519 medical students across three graduating classes. These students participated in two surveys approximately one year apart from October 2018 until November 2019. Participants completed measures on grit, burnout, and likelihood of leaving the military. These data were then merged with demographic and academic data (e.g., Medical College Admission Test scores) from the USU Long Term Career Outcome Study. These variables were then analyzed simultaneously using structural equation modeling to examine the relationships among variables in a single model. RESULTS: Results reaffirmed the 2-factor model of grit as both passion and perseverance (or interest consistency). No significant relationships emerged between burnout and other study variables. Sustained and focused interest was predictive of less likelihood of staying in the military. CONCLUSION: This study offers important insights into the relationship among well-being factors, grit, and long-term career planning in the military. The limitations of using a single-item measure of burnout and measuring behavioral intentions in a short time frame during undergraduate medical education highlight the importance of future longitudinal studies that can examine actual behaviors across a career lifespan. However, this study offers some key insights into potential impacts on the retention of military physicians. The findings suggest that military physicians who are most likely to stay in the military tend to embrace a more fluid and flexible medical specialty path. This is critical in expectation setting for the military to train and retain military physicians across a wide range of critical wartime specialties

Well-being at a Military Medical School and Implications for Military Retention.

INTRODUCTION: Physical and psychological well-being play a critical role in the academic and professional development of medical students and can alter the trajectory of a student\u27s quality of personal and professional life. Military medical students, given their dual role as officer and student, experience unique stressors and issues that may play a role in their future intentions to continue military service, as well as practice medicine. As such, this study explores well-being across the 4 years of medical school at Uniformed Services University (USU) and how well-being relates to a student\u27s likelihood to continue serving in the military and practicing medicine. METHODS: In September 2019, 678 USU medical students were invited to complete a survey consisting of three sections-the Medical Student Well-being Index (MSWBI), a single-item burnout measure, and six questions regarding their likelihood of staying in the military and medical practice. Survey responses were analyzed using descriptive statistics, analysis of variance (ANOVA), and contingency table analysis. Additionally, thematic analysis was conducted on open-ended responses included as part of the likelihood questions. RESULTS: Our MSWBI and burnout scores suggest that the overall state of well-being among medical students at USU is comparable to other studies of the medical student population. ANOVA revealed class differences among the four cohorts, highlighted by improved well-being scores as students transitioned from clerkships to their fourth-year curriculum. Fewer clinical students (MS3s and MS4s), compared to pre-clerkship students, indicated a desire to stay in the military. In contrast, a higher percentage of clinical students seemed to reconsider their medical career choice compared to their pre-clerkship student counterparts. Medicine-oriented likelihood questions were associated with four unique MSWBI items, whereas military-oriented likelihood questions were associated with one unique MSWBI item. CONCLUSION: The present study found that the overall state of well-being in USU medical students is satisfactory, but opportunities for improvement exist. Medical student well-being seemed to have a stronger association with medicine-oriented likelihood items than with military-oriented likelihood items. To obtain and refine best practices for strengthening engagement and commitment, future research should examine if and how military and medical contexts converge and diverge throughout training. This may enhance the medical school and training experience and, ultimately, reinforce, or strengthen, the desire and commitment to practice and serve in military medicine

Metabolic acetate therapy improves phenotype in the tremor rat model of Canavan disease

Genetic mutations that severely diminish the activity of aspartoacylase (ASPA) result in the fatal brain dysmyelinating disorder, Canavan disease. There is no effective treatment. ASPA produces free acetate from the concentrated brain metabolite, N-acetylaspartate (NAA). Because acetyl coenzyme A is a key building block for lipid synthesis, we postulated that the inability to catabolize NAA leads to a brain acetate deficiency during a critical period of CNS development, impairing myelination and possibly other aspects of brain development. We tested the hypothesis that acetate supplementation during postnatal myelination would ameliorate the severe phenotype associated with ASPA deficiency using the tremor rat model of Canavan disease. Glyceryltriacetate (GTA) was administered orally to tremor rats starting 7 days after birth, and was continued in food and water after weaning. Motor function, myelin lipids, and brain vacuolation were analyzed in GTA-treated and untreated tremor rats. Significant improvements were observed in motor performance and myelin galactocerebroside content in tremor rats treated with GTA. Further, brain vacuolation was modestly reduced, and these reductions were positively correlated with improved motor performance. We also examined the expression of the acetyl coenzyme A synthesizing enzyme acetyl coenzyme A synthase 1 and found upregulation of expression in tremor rats, with a return to near normal expression levels in GTA-treated tremor rats. These results confirm the critical role played by NAA-derived acetate in brain myelination and development, and demonstrate the potential usefulness of acetate therapy for the treatment of Canavan disease

Global quieting of high-frequency seismic noise due to COVID-19 pandemic lockdown measures

Human activity causes vibrations that propagate into the ground as high-frequency seismic waves. Measures to mitigate the COVID-19 pandemic caused widespread changes in human activity, leading to a months-long reduction in seismic noise of up to 50%. The 2020 seismic noise quiet period is the longest and most prominent global anthropogenic seismic noise reduction on record. While the reduction is strongest at surface seismometers in populated areas, this seismic quiescence extends for many kilometers radially and hundreds of meters in depth. This provides an opportunity to detect subtle signals from subsurface seismic sources that would have been concealed in noisier times and to benchmark sources of anthropogenic noise. A strong correlation between seismic noise and independent measurements of human mobility suggests that seismology provides an absolute, real-time estimate of population dynamics

Alternating Hemiplegia of Childhood-Related Neural and Behavioural Phenotypes in Na+,K+-ATPase α3 Missense Mutant Mice

Missense mutations in ATP1A3 encoding Na(+),K(+)-ATPase α3 have been identified as the primary cause of alternating hemiplegia of childhood (AHC), a motor disorder with onset typically before the age of 6 months. Affected children tend to be of short stature and can also have epilepsy, ataxia and learning disability. The Na(+),K(+)-ATPase has a well-known role in maintaining electrochemical gradients across cell membranes, but our understanding of how the mutations cause AHC is limited. Myshkin mutant mice carry an amino acid change (I810N) that affects the same position in Na(+),K(+)-ATPase α3 as I810S found in AHC. Using molecular modelling, we show that the Myshkin and AHC mutations display similarly severe structural impacts on Na(+),K(+)-ATPase α3, including upon the K(+) pore and predicted K(+) binding sites. Behavioural analysis of Myshkin mice revealed phenotypic abnormalities similar to symptoms of AHC, including motor dysfunction and cognitive impairment. 2-DG imaging of Myshkin mice identified compromised thalamocortical functioning that includes a deficit in frontal cortex functioning (hypofrontality), directly mirroring that reported in AHC, along with reduced thalamocortical functional connectivity. Our results thus provide validation for missense mutations in Na(+),K(+)-ATPase α3 as a cause of AHC, and highlight Myshkin mice as a starting point for the exploration of disease mechanisms and novel treatments in AHC