Descriptive Epidemiology of Physical Activity in Adolescents

This paper reviews the descriptive epidemiology of physical activity in adolescents. Large population-based studies were reviewed, along with smaller studies using objective monitoring of physical activity. Estimates showed that adolescents engage in physical activity of any intensity for a mean of one hour per day. Approximately two thirds of males and one quarter of females participate in moderate to vigorous activity for 20 min 3 or more days per week. Activity levels decline with increasing age across adolescence, and this decrease is more marked in females than in males. Comparison of these data to physical activity guidelines for adolescents suggests the vast majority are meeting the guideline of accumulating physical activity. However, a substantial number of males, and the majority of females, are not meeting the guideline for moderate to vigorous physical activity

Quantifying the Effects of Hyperthermal Atomic Oxygen and Thermal Fatigue Environments on Carbon Nanotube Sheets for Space-Based Applications

The effects of atomic oxygen and thermal fatigue on two different types of carbon nanotube sheets were studied. One set was treated with nitric acid, while the other set was left untreated. Monotonic tensile tests were performed before and after exposure to determine the effects of either exposure type on the sheets’ mechanical properties. Electrical conductivity and electromagnetic interference measurements were recorded to determine the effects of AO-exposure and thermal cycling on the sheets’ electrical properties. Neither exposure type affected the sheets’ specific strengths. Both exposure types increased the sheets’ specific stiffnesses and decreased the sheets’ strains at failure. The electrical conductivity of both sheets decreased due to the different exposure types, while the EMI shielding effectiveness was unaffected. Scanning electron microscopy was used to observe any changes in the sheets’ surface morphologies, while energy-dispersive X-ray spectroscopy was used to determine the effects of AO on the sheets’ chemical makeup

Infection programs sustained lymphoid stromal cell responses and shapes lymph node remodeling upon secondary challenge

Published: January 10, 2017Lymph nodes (LNs) are constructed of intricate networks of endothelial and mesenchymal stromal cells. How these lymphoid stromal cells (LSCs) regulate lymphoid tissue remodeling and contribute to immune responses remains poorly understood. We performed a comprehensive functional and transcriptional analysis of LSC responses to skin viral infection and found that LSC subsets responded robustly, with different kinetics for distinct pathogens. Recruitment of cells to inflamed LNs induced LSC expansion, while B cells sustained stromal responses in an antigen-independent manner. Infection induced rapid transcriptional responses in LSCs. This transcriptional program was transient, returning to homeostasis within 1 month of infection, yet expanded fibroblastic reticular cell networks persisted for more than 3 months after infection, and this altered LN composition reduced the magnitude of LSC responses to subsequent heterologous infection. Our results reveal the complexity of LSC responses during infection and suggest that amplified networks of LN stromal cells support successive immune responses.Julia L. Gregory, Anne Walter, Yannick O. Alexandre, Jyh Liang Hor, Ruijie Liu, Joel Z. Ma, Sapna Devi, Nobuko Tokuda, Yuji Owada, Laura K. Mackay, Gordon K. Smyth, William R. Heath, and Scott N. Muelle

Molecular estimation of neurodegeneration pseudotime in older brains.

The temporal molecular changes that lead to disease onset and progression in Alzheimer\u27s disease (AD) are still unknown. Here we develop a temporal model for these unobserved molecular changes with a manifold learning method applied to RNA-Seq data collected from human postmortem brain samples collected within the ROS/MAP and Mayo Clinic RNA-Seq studies. We define an ordering across samples based on their similarity in gene expression and use this ordering to estimate the molecular disease stage-or disease pseudotime-for each sample. Disease pseudotime is strongly concordant with the burden of tau (Braak score, P = 1.0 × 10-5), Aβ (CERAD score, P = 1.8 × 10-5), and cognitive diagnosis (P = 3.5 × 10-7) of late-onset (LO) AD. Early stage disease pseudotime samples are enriched for controls and show changes in basic cellular functions. Late stage disease pseudotime samples are enriched for late stage AD cases and show changes in neuroinflammation and amyloid pathologic processes. We also identify a set of late stage pseudotime samples that are controls and show changes in genes enriched for protein trafficking, splicing, regulation of apoptosis, and prevention of amyloid cleavage pathways. In summary, we present a method for ordering patients along a trajectory of LOAD disease progression from brain transcriptomic data

VALIDATE—Utilization of the Viz.ai mobile stroke care coordination platform to limit delays in LVO stroke diagnosis and endovascular treatment

BackgroundThousands of hospitals worldwide have adopted mobile artificial intelligence (AI)-based stroke care coordination platforms. Studies exploring the benefit of these platforms have been scrutinized due to small sample size, serial cohort design, and measurement of metrics with multiple determinants. In this large multi-center study, we evaluated the ability of an AI-based stroke care coordination platform to expedite contact with the interventionalist (NIR) for potential thrombectomy.MethodsAcute stroke consultations seen by TeleSpecialists, LLC physicians at 166 facilities (17 states) utilizing Viz.ai software (AI) vs. no AI software (non-AI) were extracted from the TeleCare by TeleSpecialists™ database from December 1, 2021, through March 31, 2022. The primary outcome was time from patient arrival to first contact with the interventionalist to discuss need for potential thrombectomy (Arrival-to-NIR notification).ResultsA total of 14,116 cases were analyzed. Compared to the non-AI cohort, Arrival-to-NIR notification in the AI cohort was: (1) 39.5 min faster (44.13% reduction, p < 0.001) in the overall analysis; (2) 33.0 min faster (34.0% reduction, p < 0.001) in the non-thrombectomy (non-TC) facility subgroup analysis; and (3) 34.0 min faster (43.59% reduction, p < 0.001) in the thrombectomy capable (TC) facility subgroup analysis. IQR range comparison demonstrated a significant improvement in uniformity of stroke workflow across all AI subgroups. Significant, albeit small, confounding biases were revealed in the data. The presence of AI within the non-TC subgroup correlated with a lower acceptance rate for thrombectomy by the NIR (delta = −10.79% absolute and 23.17% relative reduction, p < 0.0001).ConclusionsWhile this study was limited by our inability to capture detailed neuroimaging timelines and patient outcomes, it suggests a potential significant benefit of AI-based stroke care coordination platforms and underscores the critical need to development robust “big data” systems to study the effects of AI, and other emerging technologies, on stroke systems of care

A Human IgSF Cell-Surface Interactome Reveals a Complex Network of Protein-Protein Interactions

Cell-surface protein-protein interactions (PPIs) mediate cell-cell communication, recognition, and responses. We executed an interactome screen of 564 human cell-surface and secreted proteins, most of which are immunoglobulin superfamily (IgSF) proteins, using a high-throughput, automated ELISA-based screening platform employing a pooled-protein strategy to test all 318,096 PPI combinations. Screen results, augmented by phylogenetic homology analysis, revealed ∼380 previously unreported PPIs. We validated a subset using surface plasmon resonance and cell binding assays. Observed PPIs reveal a large and complex network of interactions both within and across biological systems. We identified new PPIs for receptors with well-characterized ligands and binding partners for “orphan” receptors. New PPIs include proteins expressed on multiple cell types and involved in diverse processes including immune and nervous system development and function, differentiation/proliferation, metabolism, vascularization, and reproduction. These PPIs provide a resource for further biological investigation into their functional relevance and may offer new therapeutic drug targets

A Human IgSF Cell-Surface Interactome Reveals a Complex Network of Protein-Protein Interactions

Cell-surface protein-protein interactions (PPIs) mediate cell-cell communication, recognition, and responses. We executed an interactome screen of 564 human cell-surface and secreted proteins, most of which are immunoglobulin superfamily (IgSF) proteins, using a high-throughput, automated ELISA-based screening platform employing a pooled-protein strategy to test all 318,096 PPI combinations. Screen results, augmented by phylogenetic homology analysis, revealed ∼380 previously unreported PPIs. We validated a subset using surface plasmon resonance and cell binding assays. Observed PPIs reveal a large and complex network of interactions both within and across biological systems. We identified new PPIs for receptors with well-characterized ligands and binding partners for “orphan” receptors. New PPIs include proteins expressed on multiple cell types and involved in diverse processes including immune and nervous system development and function, differentiation/proliferation, metabolism, vascularization, and reproduction. These PPIs provide a resource for further biological investigation into their functional relevance and may offer new therapeutic drug targets

Worldwide use of the first set of physical activity Country Cards: The Global Observatory for Physical Activity - GoPA!

Background: The work of The Global Observatory for Physical Activity-GoPA! is the first global effort to compile standardized country-level surveillance, policy and research data for physical activity in order to better understand how countries and regions address promoting physical activity. GoPA! developed standardized country-specific physical activity profiles (“Country Cards”) to summarize country-level data through 2013. The aim of this study was to assess use of the Country Cards, identify the factors associated with their use, and develop recommendations for supporting country-level physical activity promotion. Methods: Cross sectional internet-based survey conducted between August–October 2016. Target study participants were national physical activity leaders and advocates in academia, government and practice from the GoPA! countries, and members of the International Society of Physical Activity and Health. A Country Card use composite score was created based on the diversity and frequency of use. Statistical analyses on the associations between the composite score and respondent characteristics, country characteristics, barriers and opinions were conducted (including descriptive analyses and a logistic regression with robust standard errors). Results: One hundred forty three participants from 68 countries completed the survey. Use of the Country Cards was associated with being part of the GoPA! network, knowing about the Country Cards, and on the stage of country capacity for physical activity promotion. Country Card knowledge varied by country income group, region and the country specific context. More diverse and frequent use of the cards (highest tertile of the composite score for use) was associated with: 1. Being a country contact vs general participant (OR 18.32–95% CI 5.63–59.55, p = 0.002), and 2. Collaborating with a government representative working in NCDs on a monthly or more frequent contact vs less frequent contact (OR 3.39–95% CI 1.00–11.54, P < 0.05). Conclusions: For the Country Cards to have a broader impact, GoPA! will need to widen its reach beyond the academic sector. With further refinement of the cards, and training in their implementation, they could be an important tool for advancing country capacity for contextually-relevant strategies, actions and timelines for PA promotion