Bounds on \"{U}bercrossing and Petal Numbers for Knots

An $n$-crossing is a point in the projection of a knot where $n$ strands cross so that each strand bisects the crossing. An \"ubercrossing projection has a single $n$-crossing and a petal projection has a single $n$-crossing such that there are no loops nested within others. The \"ubercrossing number, $\text{\"u}(K)$, is the smallest $n$ for which we can represent a knot $K$ with a single $n$-crossing. The petal number is the number of loops in the minimal petal projection. In this paper, we relate the \"{u}bercrossing number and petal number to well-known invariants such as crossing number, bridge number, and unknotting number. We find that the bounds we have constructed are tight for $(r, r+1)$-torus knots. We also explore the behavior of \"{u}bercrossing number under composition.Comment: 13 pages, 8 figure

Healthcare employment as a risk factor for functional neurological disorder: A case-control study.

BACKGROUND AND PURPOSE Female gender, younger age and stressful life events are known predisposing factors for functional neurological disorders (FNDs). Employment in a healthcare profession has also been suggested to be a predisposing factor. We set out to conduct a large-scale case-control study to estimate the rate employment in a healthcare profession among people with FND. METHODS We included 200 consecutive patients with a confirmed diagnosis of FND, referred to our clinic at University Hospital Bern Switzerland between October 1, 2016, and August 1, 2019. In addition, we included a control group of 200 patients with a confirmed neurological disorder, matched for age and gender, seen during the same period. The primary endpoint was to compare the prevalence of healthcare professionals between the groups. We also describe the clinical manifestations and concomitant psychiatric diagnoses in the FND cohort. RESULTS Female gender was predominant (70%), and the participants' mean age was 37 years. The proportion of healthcare professionals in the FND patients was 18% (33/186), which was significantly higher than in the control group, in which it was 10.6% (17/189; p = 0.019, 95% confidence interval odds ratio 1.168-4.074). Most healthcare professionals in both cohorts were nurses (21/33 among FND patients, 10/17 among controls). Among FND patients, 140 (70%) had motor symptoms and 65 (32.5%) had a concomitant psychiatric diagnosis. CONCLUSION This case-control study confirmed a higher rate of employment in healthcare professions in patients with FND, suggesting two potential mechanisms of FND: exposure to models/specific knowledge about neurological symptoms or stress-related professional factors. This warrants further studies on underlying mechanisms and prevention

Identification of biopsychological trait markers in functional neurological disorders.

Stress is a well-known risk factor to develop a functional neurological disorder, a frequent neuropsychiatric medical condition in which patients experience a variety of disabling neurological symptoms. Only little is known about biological stress regulation, and how it interacts with predisposing biological and psychosocial risk factors. Dysregulation of the hypothalamic-pituitary-adrenal axis in patients with functional neurological disorders has been postulated but its relationship to preceding psychological trauma and brain anatomical changes remains to be elucidated. We set out to study the hypothalamic-pituitary-adrenal axis analysing the cortisol awakening response and diurnal baseline cortisol in 86 patients with mixed functional neurological symptoms compared to 76 healthy controls. We then examined the association between cortisol regulation and the severity and duration of traumatic life events. Finally, we analysed volumetric brain alterations in brain regions particularly sensitive to psychosocial stress, acting on the assumption of the neurotoxic effect of prolonged cortisol exposure. Overall, patients had a significantly flatter cortisol awakening response (P < 0.001) and reported longer (P = 0.01) and more severe (P < 0.001) emotional neglect as compared to healthy controls. Moreover, volumes of the bilateral amygdala and hippocampus were found to be reduced in patients. Using a partial least squares correlation, we found that in patients, emotional neglect plays a role in the multivariate pattern between trauma history and hypothalamic-pituitary-adrenal axis dysfunction, whilst cortisol did not relate to reduced brain volumes. This suggests that psychological stress acts as a precipitating psychosocial risk factor, whereas a reduced brain volume rather represents a biological predisposing trait marker for the disorder. Contrarily, an inverse relationship between brain volume and cortisol was found in healthy controls, representing a potential neurotoxic effect of cortisol. These findings support the theory of reduced subcortical volumes representing a predisposing trait factor in functional neurological disorders, rather than a state effect of the illness. In summary, this study supports a stress-diathesis model for functional neurological disorders and showed an association between different attributes of trauma history and abnormalities in hypothalamus-pituitary-adrenal axis function. Moreover, we suggest that reduced hippocampal- and amygdalar volumes represent a biological 'trait marker' for functional neurological disorder patients, which might contribute to a reduced resilience to stress

Elasmobranch diversity across a remote coral reef atoll revealed through environmental DNA metabarcoding

As elasmobranchs are becoming increasingly threatened, efficient methods for monitoring the distribution and diversity of elasmobranch populations are required. Environmental DNA (eDNA) metabarcoding is a progressively applied technique that enables mass identification of entire communities and is an effective method for the detection of rare and elusive species. We performed an eDNA metabarcoding survey for fish communities around a coral reef atoll in the Chagos Archipelago (Central Indian Ocean) and assessed the diversity and distribution of elasmobranch species detected within these communities. Our eDNA survey detected 353 amplicon sequence variants (ASVs) attributed to fishes, 12 of which were elasmobranchs. There were no differences in fish communities based on the presence and absence of ASVs between sample depth (surface and 40 m) or sampling habitat, but communities based on read abundance were significantly different between habitats. The dominant elasmobranch species were grey reef (Carcharhinus amblyrhynchos) and silvertip (C. albimarginatus) sharks, and elasmobranch communities were significantly different between sampling depth and habitat. Overall, we find that eDNA metabarcoding can be used to reveal the diversity of elasmobranchs within broader taxonomic assays, but further research and development of targeted metabarcoding primers may be required before it can be integrated into a toolkit for monitoring these species

Properties of the mechanosensitive channel MscS pore revealed by tryptophan scanning mutagenesis

Funding This work was supported by a Wellcome Trust Programme grant [092552/A/10/Z awarded to I.R.B., S.M., J. H. Naismith (University of St Andrews, St Andrews, U.K.), and S. J. Conway (University of Oxford, Oxford, U.K.)] (T.R. and M.D.E.), by a BBSRC grant (A.R.) [BB/H017917/1 awarded to I.R.B., J. H. Naismith, and O. Schiemann (University of St Andrews)], by a Leverhulme Emeritus Fellowship (EM-2012-060\2), and by a CEMI grant to I.R.B. from the California Institute of Technology. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013 FP7/2007-2011) under Grant PITN-GA-2011-289384 (FP7-PEOPLE-2011-ITN NICHE) (H.G.) (awarded to S.M.).Peer reviewedPublisher PD

Effects of a 4-Week Heart Rate Variability Biofeedback Intervention on Psychological and Performance Variables in Student-Athletes: A Pilot Study

PURPOSE: To examine the effects of a 4-week biofeedback intervention on coherence, psychological, and performance variables in collegiate student-athletes. METHODS: Thirteen student-athletes were randomly assigned to the intervention (one weekly biofeedback session for 4-weeks) or control group (no sessions). Data were collected at pre and post-intervention using weekly averaged coherence scores, psychological measures for depression, arousal, stress, resiliency, and performance outcome measures. RESULTS: A 3 (Time) x 4 (Week average) repeated measures ANOVA was independently conducted to examine differences between time and weekly coherence average for coherence scores. No significant differences were found for “at rest”, pre, or post-practice coherence scores. A 2 (treatment group) x 4 (Week) repeated measures ANOVAs were independently conducted to examine differences between treatment groups and week average for performance, resilience, and recovery. Significant differences were found for performance by time (p = .029). For the psychological variables, 2 (treatment group) X 2 (Time) repeated measures ANOVAs were independently conducted to examine differences between treatment group and time for CESD, AD-ACL, CSSS, and the ASSQ sleep score and no significant differences were found. CONCLUSIONS: Overall the biofeedback intervention did not improve coherence, psychological, or performance variables between the groups. While the biofeedback intervention did not show significant changes in this pilot study, there is potential for future research to address male participants and a change in timing during the season

Examination of Anger Prevalence in NCAA Division I Student-Athletes

Purpose: Anger associated with sports participation may affect inability to acutely process anger, may decrease performance and increase the likelihood of risk-taking behavior in collegiate athletes. Therefore, the purpose was to examine the prevalence of anger in collegiate student-athletes across sex, academic status, and sport type. Methods: A cross sectional study over a three-year period examined 759 NCAA Division I student-athletes at one institution (age=20±1 years; males: n=259; females: n=500) completed an optional pre-participation behavioral health screening questionnaire, personal demographic information and the Anger Index Self-Test. Results: Overall, 37.2% (n=282/759; males=127/259, 49.0%; females=155/500, 31.0%) of participants were at high-risk for anger. We identified a significant difference between the anger and sex [Χ2(2, N=759) =28.1, P≤0.01]. We also identified a significant difference between the anger and sport type [Χ2(8, N=759)=32.1, P≤0.01] with 55.2% (n=419/759) at moderate risk for anger despite sport type; with the highest percentages presenting high-risk for anger within power sports (n= 64/116, 55.2%) and ball sports (n=98/240, 40.8%). No significant differences were identified for anger risk and academic status (P=0.66). Conclusions: Female collegiate student-athletes demonstrated a higher prevalence of anger than male collegiate student-athletes, yet more males were high-risk. Most student-athletes displayed moderate-risk for anger across different sports. Anger across academic status was not significantly different implying that anger management and coping skills may need to be taught during their student-athlete tenure to mitigate the identified risk. A collegiate student-athlete’s inability to process anger may affect sports performance and have negative consequences on their personal and social life. A primary prevention mechanism exists to explore proper coping mechanisms for anger during sport before the onset of mental health conditions that could exacerbate the experience for the individual