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An unsolved problem gets elementary and middle school students thinking and doing mathematics like mathematicians.

During cortical development and throughout adulthood, oligodendrocytes add myelin internodes to glutamatergic projection neurons and GABAergic inhibitory neurons. In addition to directing node of Ranvier formation, to enable saltatory conduction and influence action potential transit time, oligodendrocytes support axon health by communicating with axons via the periaxonal space and providing metabolic support that is particularly critical for healthy ageing. In this review we outline the timing of oligodendrogenesis in the developing mouse and human cortex and describe the important role that oligodendrocytes play in sustaining and modulating neuronal function. We also provide insight into the known and speculative impact that myelination has on cortical axons and their associated circuits during the developmental critical periods and throughout life, particularly highlighting their life-long role in learning and remembering.

OBJECTIVES The Farmer’s Market Nutrition Program (FMNP) provides fresh, locally grown fruits and vegetables (FV) to eligible participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). However, redemption of FMNP benefits remains low. This qualitative study explores facilitators and barriers to produce access and FMNP redemption for caregivers of WIC-eligible children in Philadelphia during the COVID-19 pandemic. METHODS We conducted semistructured phone interviews with caregivers between August and December 2020 to understand experiences with produce access and programming preferences to increase benefit redemption and produce consumption. We used content analysis with constant comparison with code interviews inductively and identified emerging themes through an iterative process. RESULTS Participants (n = 30) wanted their children to eat more produce but described barriers to produce access, including limited availability, higher cost, and limited time. The Supplemental Nutrition Assistance Program and WIC benefits improved the ability to purchase produce, but difficulties with electronic benefit transfer and pandemic-related office closures limited use of WIC benefits. Similarly, lack of convenient market locations and hours prohibited use of FMNP benefits. Caregivers described that an ideal food program would be delivery based, low cost, offer a variety of FV, and provide recipes and educational activities. CONCLUSIONS WIC-eligible caregivers want their children to eat more produce; however, they face multiple barriers in redeeming their benefits to access fresh produce. Delivery-based, low-cost produce programs may lead to increased produce access as well as benefit use. Future study is needed on feasibility and acceptability of produce delivery options among WIC-eligible families.

Background Guidelines recommend fixed cardiac troponin thresholds for the assessment of patients with suspected acute coronary syndrome, however, performance varies in important patient groups as concentrations are influenced by age, sex and comorbidities. This limitation can be addressed using machine learning algorithms. Methods Machine learning algorithms were developed that integrate cardiac troponin concentrations at presentation or on serial testing with age, sex and clinical features in 10,038 consecutive emergency patients with suspected acute coronary syndrome. The primary outcome was an adjudicated diagnosis of type 1, type 4b or type 4c myocardial infarction. The best performing algorithm was selected for the CoDE-ACS (Collaboration for the Diagnosis and Evaluation of Acute Coronary Syndrome) decision-support tool, and performance was externally validated in 3,035 patients pooled from three prospective studies. Findings CoDE-ACS had excellent discrimination and calibration using cardiac troponin at presentation (area under curve [AUC] 0.959, 95% confidence interval 0.948–0.971, Brier score 0.040), in the pooled external validation cohort. At presentation, the rule-out score identified 62.1% (1,885/3,035) of all patients as low-probability of myocardial infarction with a 99.5% (99.1–99.7%) negative predictive value and 97.0% (96.3–97.6%) sensitivity. The rule-in score identified 8.3% (252/3,035) of patients as high-probability with an 83.7% (82.4–85.0%) positive predictive value and 98.5% (98.0–98.9%) specificity. Performance of the rule-out and rule-in scores was consistent across patient subgroups (Figure 1 and Figure 2). CoDE-ACS incorporating a second cardiac troponin measurement also had excellent discrimination and calibration (AUC 0.971 [0.962–0.980], Brier score 0.039) and refined the individualised probabilities in the 29.5% (898/3,035) of patients neither ruled-out or ruled-in at presentation to guide further investigation. Conclusions We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements. Conclusions We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health ResearchBritish Heart Foundation

Passive recovery techniques are popular and offer a diverse spectrum of options for athletes and the clinicians providing care for them. These techniques are intended to minimize the negative effects of training or competition, thus enabling the athlete a quicker return to peak performance. Current evidence demonstrates improved athlete recovery with compression garments, cold water immersion, partial body cryotherapy, hyperbaric oxygen, and vibratory therapies. Other popular modalities, such as compression devices, whole body cryotherapy, percussive gun-assisted therapy, neuromuscular electrical stimulation, and pulsed electromagnetic therapy lack convincing evidence concerning athlete recovery. This article seeks to review the current literature and offer the reader an updated understanding of the mechanisms for each modality and the evidence regarding each modality's potential benefit in an athlete's recovery strategy.

Enteric duplication cysts are rare congenital entities most commonly found in the esophagus, ileum or colon but can be in remote locations such as the biliary tree, liver or pancreas. Pancreatic duplication cysts are very uncommon and usually present in adulthood with pancreatitis or abdominal pain. Here, we present a unique and complex case of an infant with a pancreatic duplication cyst initially presenting with an upper gastrointestinal bleed followed by pancreatitis, cyst infection and gastric outlet obstruction.

How players react to failure remains an understudied area of games research. Previous work has shown that mastery orientation can effectively gauge how players will behave in response to failure in a video game. This study shows that after playing a challenging video game for two weeks, women who initially scored lower on this scale significantly increased, while men significantly decreased. No differences were found regarding how much they played, how often they failed, or their reactions to in-game failure. This suggests that this change is not rooted in their behavior, but in their perceptions of their ability to persist in these environments. These perceptions may have been influenced by well-documented stereotype biases that women and other individuals face entering video game communities. While this doesn’t address the root cause, it suggests that the perception of their ability to persist through challenging games can change with exposure, relieving these held biases.

Background Discussions on the diagnostic and management of acquired pediatric lung pathology are usually published by large tertiary children's hospitals. It is likely that much of this pathology is actually seen and managed in nonacademic practices. Methods A 10-year retrospective review of patients under 18-years of age, treated for lung abscesses or empyema was performed. Results Nineteen empyema and four lung abscesses were included. Presenting symptoms, workup, and management are reviewed. A unique subset (n = 4) of atypical pulmonary pathology is described. A 14-year-old with a vaping history and a lung abscess misdiagnosed as an empyema. A 15-year-old with primary pulmonary Hodgkin's lymphoma presenting as a lung abscess and empyema. A 5-year-old with an empyema complicated by a bronchopleural fistula and a 21-year-old with autism and an acquired lung cyst. Conclusion Our dilemmas, experiences, and strategies in managing complex lung disease are generalized to community-based practice.

Objective The aim of this study was to evaluate Scotland's national HIV preexposure prophylaxis (PrEP) programme in relation to PrEP uptake and associated population-level impact on HIV incidence among MSM. Design A retrospective cohort study within real-world implementation. Methods Comparison of HIV diagnoses from national surveillance data and HIV incidence within a retrospective cohort of HIV-negative MSM attending sexual health clinics from the National Sexual Health information system between the 2-year periods pre(July 2015-June 2017) and post(July 2017-June 2019) introduction of PrEP. Results Of 16 723 MSM attending sexual health services in the PrEP period, 3256 (19.5%) were prescribed PrEP. Between pre-PrEP and PrEP periods, new HIV diagnoses among MSM declined from 229 to 184, respectively [relative risk reduction (RRR): 19.7%, 95% confidence interval (95% CI) 2.5-33.8]; diagnosed recently acquired infections declined from an estimated 73 to 47, respectively (35.6%, 95% CI 7.1-55.4). Among MSM attending sexual health clinics, HIV incidence per 1000 person-years declined from 5.13 (95% CI 3.90-6.64) pre-PrEP to 3.25 (95% CI 2.30-4.47) in the PrEP period (adjusted IRR 0.57, 95% CI 0.37-0.87). Compared with the pre-PrEP period, incidence of HIV was lower in the PrEP period for those prescribed PrEP (aIRR 0.25, 95% CI 0.09-0.70) and for those not prescribed PrEP (aIRR 0.68, 95% CI 0.43-1.05). Conclusion We demonstrate national population-level impact of PrEP for the first time in a real-world setting. HIV incidence reduced in MSM who had been prescribed PrEP and, to a lesser extent, in those who had not. Promotion of the benefits of PrEP needs to extend to MSM who do not access sexual health clinics.

Objectives This work sought to determine the prognosis for dogs for return to athletic function in canine agility competitions after digit amputation. Materials and Methods Data were collected using an Internet-based survey of owners of agility dogs with digit disorders that required amputation. Signalment and physical characteristics were compared between dogs with traumatic and nontraumatic disorders. Athletic performance before and after amputation was assessed subjectively by owner opinion and objectively for eight dogs using competition performance records. Results Problems leading to digit amputation in 46 dogs included acute or chronic traumatic lesions (30 dogs), infection (7 dogs), neoplasia (7 dogs), and cystic lesions (2 dogs). There were no differences in signalment or physical characteristics between dogs with traumatic and nontraumatic disorders. Of the 46 dogs, 39 (84.7%) had returned to agility at the time of the survey and 94.6% of the owners (37/39) were satisfied with performance after amputation. No dog failed to return to agility as a result of the digit disorder or amputation. There was no difference in mean competition speed before and after amputation. Clinical Significance Most agility dogs undergoing digit amputation perform satisfactorily after surgery, although modifications to performance criteria may be appropriate for some.

Primary cilia are small microtubule‐based organelles capable of transducing signals from growth factor receptors embedded in the cilia membrane. Developmentally, oligodendrocyte progenitor cells (OPCs) express genes associated with primary cilia assembly, disassembly, and signaling, however, the importance of primary cilia for adult myelination has not been explored. We show that OPCs are ciliated in vitro and in vivo, and that they disassemble their primary cilia as they progress through the cell cycle. OPC primary cilia are also disassembled as OPCs differentiate into oligodendrocytes. When kinesin family member 3a (Kif3a), a gene critical for primary cilium assembly, was conditionally deleted from adult OPCs in vivo (Pdgfrα‐CreER™:: Kif3a fl/fl transgenic mice), OPCs failed to assemble primary cilia. Kif3a‐deletion was also associated with reduced OPC proliferation and oligodendrogenesis in the corpus callosum and motor cortex and a progressive impairment of fine motor coordination., Main Points OPCs disassemble primary cilia upon cell cycle re‐entry.Deletion of Kif3a from OPCs prevents primary cilia assembly and reduces OPC proliferation.Deletion of Kif3a from adult OPCs in vivo reduces oligodendrogenesis and impairs motor function.

In this lesson, third graders were asked how many degrees is a full rotation around a circle. After we gave students time and space to disagree, to make and test conjectures, and to explore, they reasoned about angle as turn and determined a full rotation is 360 degrees.

Myelin and axon losses are associated with cognitive decline in healthy ageing but are worse in people diagnosed with tauopathy. To determine whether tauopathy is also associated with enhanced myelin plasticity, we evaluated the behaviour of OPCs in mice that expressed a human pathological variant of microtubule‐associated protein tau (MAPTP301S ). By 6 months of age (P180), MAPTP301S mice overexpressed hyperphosphorylated tau and had developed reactive gliosis in the hippocampus but had not developed overt locomotor or memory impairment. By performing cre‐lox lineage tracing of adult OPCs, we determined that the number of newborn oligodendrocytes added to the hippocampus, entorhinal cortex and fimbria was equivalent in control and MAPTP301S mice prior to P150. However, between P150 and P180, significantly more new oligodendrocytes were added to these regions in the MAPTP301S mouse brain. This large increase in new oligodendrocyte number was not the result of increased OPC proliferation, nor did it alter oligodendrocyte density in the hippocampus, entorhinal cortex or fimbria, which was equivalent in P180 wild‐type and MAPTP301S mice. Furthermore, the proportion of hippocampal and fimbria axons with myelin was unaffected by tauopathy. However, the proportion of myelinated axons that were ensheathed by immature myelin internodes was significantly increased in the hippocampus and fimbria of P180 MAPTP301S mice, when compared with their wild‐type littermates. These data suggest that MAPTP301S transgenic mice experience significant oligodendrocyte turnover, with newborn oligodendrocytes compensating for myelin loss early in the development of tauopathy., Mice overexpressing a pathological variant of human microtubule‐associated protein tau (MAPT P301S) experience increased oligodendrogenesis in the hippocampus, entorhinal cortex and fimbria between 5 and 6 months of age. Total oligodendrocyte and oligodendrocyte progenitor cell number, axon density and the per cent of myelinated axons remain normal, though there is an increase in newly generated myelin, suggesting that oligodendrocyte turnover occurs early in the development of tauopathy.

Redox flow batteries represent a remarkable alternative for grid-scale energy storage. They commonly employ carbon felts or carbon papers, which suffer from low activity towards the redox reactions involved, leading to poor performance. Here we propose the use of electrospun freestanding carbon materials derived from lignin as alternative sustainable electrodes for all-vanadium flow batteries. The lignin-derived carbon electrospun mats exhibited a higher activity towards the VO2+/VO2+ reaction than commercial carbon papers when tested in a three-electrode electrochemical cell (or half-cell), which we attribute to the higher surface area and higher amount of oxygen functional groups at the surface. The electrospun carbon electrodes also showed performance comparable to commercial carbon papers, when tested in a full cell configuration. The modification of the surface chemistry with the addition of phosphorous produced different effect in both samples, which needs further investigation. This work demonstrates for the first time the application of sustainably produced electrospun lignin-derived carbon electrodes in a redox flow cell, with comparable performance to commercial materials and establishes the great potential of biomass-derived carbons in energy devices.

As algorithms come to govern every aspect of our lives—from bank loans, to job applications, to traffic patterns, to our media consumption patterns—communication research has become increasingly concerned with how we govern algorithms. Building on the methodological frameworks established by critical information researchers like Safiya Noble, Tarleton Gillespie, and Nick Seaver, this essay argues that we do not need to reverse engineer the “black box” to understand its impacts because they can be found through qualitative methodologies instead. This essay rejects the “black box” as an epistemic premise upon which critical algorithmic literacies can be built by using discourse analysis to observe how the unknowable language of the algorithm is deployed discursively within gamer communities to establish and maintain patriarchal power. This essay shows how the “black box” is used by fan communities to advance a patriarchal understanding of what we term paradigms of “balance” and “realism” in game design.

Background Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease, characterised by oligodendrocyte death and demyelination. Oligodendrocyte progenitor cells can differentiate into new replacement oligodendrocytes; however, remyelination is insufficient to protect neurons from degeneration in people with MS. We previously reported that 4 weeks of daily low-intensity repetitive transcranial magnetic stimulation (rTMS) in an intermittent theta-burst stimulation (iTBS) pattern increased the number of new myelinating oligodendrocytes in healthy adult mice. This study translates this rTMS protocol and aims to determine its safety and tolerability for people living with MS. We will also perform magnetic resonance imaging (MRI) and symptom assessments as preliminary indicators of myelin addition following rTMS. Methods Participants (N = 30, aged 18–65 years) will have a diagnosis of relapsing-remitting or secondary progressive MS. ≤2 weeks before the intervention, eligible, consenting participants will complete a physical exam, baseline brain MRI scan and participant-reported MS symptom assessments [questionnaires: Fatigue Severity Scale, Quality of Life (AQoL-8D), Hospital Anxiety and Depression Scale; and smartphone-based measures of cognition (electronic symbol digit modalities test), manual dexterity (pinching test, draw a shape test) and gait (U-Turn test)]. Participants will be pseudo-randomly allocated to rTMS (n=20) or sham (placebo; n=10), stratified by sex. rTMS or sham will be delivered 5 days per week for 4 consecutive weeks (20 sessions, 6 min per day). rTMS will be applied using a 90-mm circular coil at low-intensity (25% maximum stimulator output) in an iTBS pattern. For sham, the coil will be oriented 90° to the scalp, preventing the magnetic field from stimulating the brain. Adverse events will be recorded daily. We will evaluate participant blinding after the first, 10th and final session. After the final session, participants will repeat symptom assessments and brain MRI, for comparison with baseline. Participant-reported assessments will be repeated at 4-month post-allocation follow-up. Discussion This study will determine whether this rTMS protocol is safe and tolerable for people with MS. MRI and participant-reported symptom assessments will serve as preliminary indications of rTMS efficacy for myelin addition to inform further studies. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12619001196134. Registered on 27 August 2019

Oligodendrocyte progenitor cells (OPCs) express protocadherin 15 (Pcdh15), a member of the cadherin superfamily of transmembrane proteins. Little is known about the function of Pcdh15 in the central nervous system (CNS), however, Pcdh15 expression can predict glioma aggression and promote the separation of embryonic human OPCs immediately following a cell division. Herein, we show that Pcdh15 knockdown significantly increases extracellular signal-related kinase (ERK) phosphorylation and activation to enhance OPC proliferation in vitro. Furthermore, Pcdh15 knockdown elevates Cdc42-Arp2/3 signalling and impairs actin kinetics, reducing the frequency of lamellipodial extrusion and slowing filopodial withdrawal. Pcdh15 knockdown also reduces the number of processes supported by each OPC and new process generation. Our data indicate that Pcdh15 is a critical regulator of OPC proliferation and process motility, behaviours that characterise the function of these cells in the healthy CNS, and provide mechanistic insight into the role that Pcdh15 might play in glioma progression.

The field of Human Resource Management (HRM) has long recognized the importance of interpersonal influence for employee and organizational effectiveness. HRM research and practice have focused primarily on individuals’ characteristics and behaviors as a means to understand “who” is influential in organizations, with substantially less attention paid to social networks. To reinvigorate a focus on network structures to explain interpersonal influence, the authors present a comprehensive account of how network structures enable and constrain influence within organizations. The authors begin by describing how power and status, two key determinants of individual influence in organizations, operate through different mechanisms, and delineate a range of network positions that yield power, reflect status, and/or capture realized influence. Then, the authors extend initial structural views of influence beyond the positions of individuals to consider how network structures within and between groups – capturing group social capital and/or shared leadership – enable and constrain groups’ ability to influence group members, other groups, and the broader organizational system. The authors also discuss how HRM may leverage these insights to facilitate interpersonal influence in ways that support individual, group, and organizational effectiveness.