119 research outputs found

    Clustering daily patterns of human activities in the city

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    Data mining and statistical learning techniques are powerful analysis tools yet to be incorporated in the domain of urban studies and transportation research. In this work, we analyze an activity-based travel survey conducted in the Chicago metropolitan area over a demographic representative sample of its population. Detailed data on activities by time of day were collected from more than 30,000 individuals (and 10,552 households) who participated in a 1-day or 2-day survey implemented from January 2007 to February 2008. We examine this large-scale data in order to explore three critical issues: (1) the inherent daily activity structure of individuals in a metropolitan area, (2) the variation of individual daily activities—how they grow and fade over time, and (3) clusters of individual behaviors and the revelation of their related socio-demographic information. We find that the population can be clustered into 8 and 7 representative groups according to their activities during weekdays and weekends, respectively. Our results enrich the traditional divisions consisting of only three groups (workers, students and non-workers) and provide clusters based on activities of different time of day. The generated clusters combined with social demographic information provide a new perspective for urban and transportation planning as well as for emergency response and spreading dynamics, by addressing when, where, and how individuals interact with places in metropolitan areas.Massachusetts Institute of Technology. Dept. of Urban Studies and PlanningUnited States. Dept. of Transportation (Region One University Transportation Center)Singapore-MIT Alliance for Research and Technolog

    Evaluation of a Theory-Informed Implementation Intervention for the Management of Acute Low Back Pain in General Medical Practice: The IMPLEMENT Cluster Randomised Trial

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    Introduction: This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. Methods: General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. Results: 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. Conclusions: The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN01260600009853

    The Return to Final Paper Examining in English National Curriculum Assessment and School Examinations: Issues of Validity, Accountability and Politics

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    There are sound educational and examining reasons for the use of coursework assessment and practical assessment of student work by teachers in schools for purposes of reporting examination grades. Coursework and practical work test a range of different curriculum goals to final papers and increase the validity and reliability of the result. However, the use of coursework and practical work in tests and examinations has been a matter of constant political as well as educational debate in England over the last 30 years. The paper reviews these debates and developments and argues that as accountability pressures increase, the evidence base for published results is becoming narrower and less valid as the system moves back to wholly end-of-course testing

    Inflammatory Gene Regulatory Networks in Amnion Cells Following Cytokine Stimulation: Translational Systems Approach to Modeling Human Parturition

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    A majority of the studies examining the molecular regulation of human labor have been conducted using single gene approaches. While the technology to produce multi-dimensional datasets is readily available, the means for facile analysis of such data are limited. The objective of this study was to develop a systems approach to infer regulatory mechanisms governing global gene expression in cytokine-challenged cells in vitro, and to apply these methods to predict gene regulatory networks (GRNs) in intrauterine tissues during term parturition. To this end, microarray analysis was applied to human amnion mesenchymal cells (AMCs) stimulated with interleukin-1β, and differentially expressed transcripts were subjected to hierarchical clustering, temporal expression profiling, and motif enrichment analysis, from which a GRN was constructed. These methods were then applied to fetal membrane specimens collected in the absence or presence of spontaneous term labor. Analysis of cytokine-responsive genes in AMCs revealed a sterile immune response signature, with promoters enriched in response elements for several inflammation-associated transcription factors. In comparison to the fetal membrane dataset, there were 34 genes commonly upregulated, many of which were part of an acute inflammation gene expression signature. Binding motifs for nuclear factor-κB were prominent in the gene interaction and regulatory networks for both datasets; however, we found little evidence to support the utilization of pathogen-associated molecular pattern (PAMP) signaling. The tissue specimens were also enriched for transcripts governed by hypoxia-inducible factor. The approach presented here provides an uncomplicated means to infer global relationships among gene clusters involved in cellular responses to labor-associated signals

    Indian Hedgehog release from TNF activated renal epithelia drives local and remote organ fibrosis

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    Progressive fibrosis is a feature of aging and chronic tissue injury in multiple organs, including the kidney and heart. Glioma-associated oncogene 1 expressing (Gli1+) cells are a major source of activated fibroblasts in multiple organs, but the links between injury, inflammation, and Gli1+ cell expansion and tissue fibrosis remain incompletely understood. We demonstrated that leukocyte-derived tumor necrosis factor (TNF) promoted Gli1+ cell proliferation and cardiorenal fibrosis through induction and release of Indian Hedgehog (IHH) from renal epithelial cells. Using single-cell–resolution transcriptomic analysis, we identified an “inflammatory” proximal tubular epithelial (iPT) population contributing to TNF- and nuclear factor κB (NF-κB)–induced IHH production in vivo. TNF-induced Ubiquitin D (Ubd) expression was observed in human proximal tubular cells in vitro and during murine and human renal disease and aging. Studies using pharmacological and conditional genetic ablation of TNF-induced IHH signaling revealed that IHH activated canonical Hedgehog signaling in Gli1+ cells, which led to their activation, proliferation, and fibrosis within the injured and aging kidney and heart. These changes were inhibited in mice by Ihh deletion in Pax8-expressing cells or by pharmacological blockade of TNF, NF-κB, or Gli1 signaling. Increased amounts of circulating IHH were associated with loss of renal function and higher rates of cardiovascular disease in patients with chronic kidney disease. Thus, IHH connects leukocyte activation to Gli1+ cell expansion and represents a potential target for therapies to inhibit inflammation-induced fibrosis

    Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator

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    Is there only one electric eel species? For two and a half centuries since its description by Linnaeus, Electrophorus electricus has captivated humankind by its capacity to generate strong electric discharges. Despite the importance of Electrophorus in multiple fields of science, the possibility of additional species-level diversity in the genus, which could also reveal a hidden variety of substances and bioelectrogenic functions, has hitherto not been explored. Here, based on overwhelming patterns of genetic, morphological, and ecological data, we reject the hypothesis of a single species broadly distributed throughout Greater Amazonia. Our analyses readily identify three major lineages that diverged during the Miocene and Pliocene—two of which warrant recognition as new species. For one of the new species, we recorded a discharge of 860 V, well above 650 V previously cited for Electrophorus, making it the strongest living bioelectricity generator. © 2019, The Author(s)
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