Students’ Use of Symmetry with Gauss’s Law

To study introductory student difficulties with electrostatics, we compared student techniques when finding the electric field for spherically symmetric and non-spherically symmetric charged conductors. We used short interviews to design a free-response and multiple-choice-multiple-response survey that was administered to students in introductory calculus-based courses. We present the survey results and discuss them in light of Singh\u27s results for Gauss\u27s Law, Collins and Ferguson\u27s epistemic forms and games, and Tuminaro\u27s extension of games and frames

Meaghan

Editorial by Chris Healy, Katrina Schlunke, Prudence Black, Stephen Muecke, and Catherine Driscoll

Uncovering protein function: from classification to complexes

Almost all interactions and reactions that occur in living organisms involve proteins. The various biological roles of proteins include, but are not limited to, signal transduction, gene transcription, cell death, immune function, structural support, and catalysis of all the chemical reactions that enable organisms to survive. The varied roles of proteins have led to them being dubbed 'the workhorses of all living organisms'. This article discusses the functions of proteins and how protein function is studied in a laboratory setting. In this article, we begin by examining the functions of protein domains, followed by a discussion of some of the major classes of proteins based on their function. We consider protein binding in detail, which is central to protein function. We then examine how protein function can be altered through various mechanisms including post-translational modification, and changes to environment, oligomerisation and mutations. Finally, we consider a handful of the techniques employed in the laboratory to understand and measure the function of proteins

A pilot study investigating the use of 4D flow MRI for the assessment of splanchnic flow in patients suspected of mesenteric ischaemia

The most common cause of chronic mesenteric ischaemia is atherosclerosis which results in limitation of blood flow to the gastrointestinal tract. This pilot study aimed to evaluate 4D flow MRI as a potential tool for the analysis of blood flow changes post-prandial within the mesenteric vessels. The mesenteric vessels of twelve people were scanned; patients and healthy volunteers. A baseline MRI scan was performed after 6 h of fasting followed by a post-meal scan. Two 4D flow datasets were acquired, over the superior mesenteric artery (SMA) and the main portal venous vessels. Standard 2D time-resolved PC-MRI slices were also obtained across the aorta above the coeliac trunk, superior mesenteric vein, splenic vein and portal vein (PV). In the volunteer cohort there was a marked increase in blood flow post-meal within the PV (p = 0.028), not seen in the patient cohort (p = 0.116). Similarly, there were significant flow changes within the SMA of volunteers (p = 0.028) but not for the patient group (p = 0.116). Our pilot data has shown that there is a significant haemodynamic response to meal challenge in the PV and SMA in normal subjects compared to clinically apparent CMI patients. Therefore, the interrogation of mesenteric venous vessels exclusively is a feasible method to measure post-prandial flow changes in CMI patients

The Innocent Bystander: A Scenario Based Study on the Impact of Leadership Gossip

The purpose of this study was to understand how witnessing workplace gossip between a supervisor and an employee in a hypothetical scenario impacts ratings of acceptability of gossip behavior, leader quality ratings, relationship quality, and future comfort with the leader. Data were gathered from 207 college students who read a scenario involving gossip, which varied in the target (about oneself or another) and the domain (about work or personal matters) and then responded to a series of questions about the scenario. Across all four scenarios, leaders received fairly unfavorable ratings for participating in gossip behavior. However, we did not find consistent main effects based on the target or domain and there were no significant interactions between domain and target. Limitations and practical implications are further discussed

Student Perceptions of Stress and Relaxation at the Beginning and End of the Week

This study examined whether student perceptions of stress, their level of relaxation remorse, and their health symptoms varied at the beginning verses the end of the week. We also examined how stress and relaxation remorse correlate with health symptoms at the beginning verses the end of the week. The findings of this study indicate that students have more relaxation remorse, perceived stress, and health symptoms on Monday than on Friday; additionally, students reported fewer coping activities on Monday than on Friday. Our results also indicate that students’ level perceived stress and relaxation remorse relate to their level of health symptoms. These findings could be used to inform future interventions to promote healthy stress management among college students

Using Digital Tools to Train Health Emergencies Personnel in Fragile Contexts

The Leadership in Emergencies learning programme, launched in 2019, was designed to strengthen the competencies of World Health Organization (WHO) and Member State staff in teamwork, decision-making and communication, key skills required to lead effectively in emergencies. While the programme was initially used to train 43 staff in a workshop setting, the COVID-19 pandemic required a new remote approach. An online learning environment was developed using a variety of digital tools including WHO's open learning platform, OpenWHO.org. The strategic use of these technologies enabled WHO to dramatically expand access to the programme for personnel responding to health emergencies in fragile contexts and increase participation among key groups that were previously underserved.publishedVersionPeer reviewe

Mathematical model of a telomerase transcriptional regulatory network developed by cell-based screening: analysis of inhibitor effects and telomerase expression mechanisms

Cancer cells depend on transcription of telomerase reverse transcriptase (TERT). Many transcription factors affect TERT, though regulation occurs in context of a broader network. Network effects on telomerase regulation have not been investigated, though deeper understanding of TERT transcription requires a systems view. However, control over individual interactions in complex networks is not easily achievable. Mathematical modelling provides an attractive approach for analysis of complex systems and some models may prove useful in systems pharmacology approaches to drug discovery. In this report, we used transfection screening to test interactions among 14 TERT regulatory transcription factors and their respective promoters in ovarian cancer cells. The results were used to generate a network model of TERT transcription and to implement a dynamic Boolean model whose steady states were analysed. Modelled effects of signal transduction inhibitors successfully predicted TERT repression by Src-family inhibitor SU6656 and lack of repression by ERK inhibitor FR180204, results confirmed by RT-QPCR analysis of endogenous TERT expression in treated cells. Modelled effects of GSK3 inhibitor 6-bromoindirubin-3′-oxime (BIO) predicted unstable TERT repression dependent on noise and expression of JUN, corresponding with observations from a previous study. MYC expression is critical in TERT activation in the model, consistent with its well known function in endogenous TERT regulation. Loss of MYC caused complete TERT suppression in our model, substantially rescued only by co-suppression of AR. Interestingly expression was easily rescued under modelled Ets-factor gain of function, as occurs in TERT promoter mutation. RNAi targeting AR, JUN, MXD1, SP3, or TP53, showed that AR suppression does rescue endogenous TERT expression following MYC knockdown in these cells and SP3 or TP53 siRNA also cause partial recovery. The model therefore successfully predicted several aspects of TERT regulation including previously unknown mechanisms. An extrapolation suggests that a dominant stimulatory system may programme TERT for transcriptional stability

FTO Gene Associated Fatness in Relation to Body Fat Distribution and Metabolic Traits throughout a Broad Range of Fatness

A common single nucleotide polymorphism (SNP) of FTO (rs9939609, T/A) is associated with total body fatness. We investigated the association of this SNP with abdominal and peripheral fatness and obesity-related metabolic traits in middle-aged men through a broad range of fatness present already in adolescence.Obese young Danish men (n = 753, BMI > or = 31.0 kg/m(2)) and a randomly selected group (n = 879) from the same population were examined in three surveys (mean age 35, 46 and 49 years, respectively). The traits included anthropometrics, body composition, oral glucose tolerance test, blood lipids, blood pressure, fibrinogen and aspartate aminotransferase. Logistic regression analysis was used to assess the age-adjusted association between the phenotypes and the odds ratios for the FTO rs9939609 (TT and TA genotype versus the AA genotype), for anthropometrics and body composition estimated per unit z-score. BMI was strongly associated with the AA genotype in all three surveys: OR = 1.17, p = 1.1*10(-6), OR = 1.20, p = 1.7*10(-7), OR = 1.17, p = 3.4*10(-3), respectively. Fat body mass index was also associated with the AA genotype (OR = 1.21, p = 4.6*10(-7) and OR = 1.21, p = 1.0*10(-3)). Increased abdominal fatness was associated with the AA genotype when measured as waist circumference (OR = 1.21, p = 2.2*10(-6) and OR = 1.19, p = 5.9*10(-3)), sagittal abdominal diameter (OR = 1.17, p = 1.3*10(-4) and OR = 1.18, p = 0.011) and intra-abdominal adipose tissue (OR = 1.21, p = 0.005). Increased peripheral fatness measured as hip circumference (OR = 1.19, p = 1.3*10(-5) and OR = 1.18, p = 0.004) and lower body fat mass (OR = 1.26, p = 0.002) was associated with the AA genotype. The AA genotype was significantly associated with decreased Stumvoll insulin sensitivity index (OR = 0.93, p = 0.02) and with decreased non-fasting plasma HDL-cholesterol (OR = 0.57, p = 0.037), but not with any other of the metabolic traits. However, all significant results for both body fat distribution and metabolic traits were explained by a mediating effect of total fat mass.The association of the examined FTO SNP to general fatness throughout the range of fatness was confirmed, and this association explains the relation between the SNP and body fat distribution and decreased insulin sensitivity and HDL-cholesterol. The SNP was not significantly associated with other metabolic traits suggesting that they are not derived from the general accumulation of body fat