50 research outputs found

    Machine learning models for LoDI indices.

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    Two indices published monthly by the Logistics and Distribution Institute (LoDI) predict changes in logistics and distribution activity levels nationally and regionally and are useful for organizations when planning projects and expenses. This research validates the current linear regression model, updates the index conversion method, and introduces machine learning models. New source data are introduced to the models to validate the current linear regression model and a comparative analysis verifies that the current source data are robust. A rolling average is used for index conversion in place of a fixed reference month to reflect recent changes in employment levels. Three linear machine learning models are tested on the data. Patterns among the residuals indicate non-linearity. Four non-linear models are tested on the data and compared to the linear models. The non-linear models are found to be more accurate than the linear models for both the national index and regional index

    Crowdsourcing hypothesis tests: Making transparent how design choices shape research results

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    To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div

    Mitochondrial respiration controls neoangiogenesis during wound healing and tumour growth

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    The vasculature represents a highly plastic compartment, capable of switching from a quiescent to an active proliferative state during angiogenesis. Metabolic reprogramming in endothelial cells (ECs) thereby is crucial to cover the increasing cellular energy demand under growth conditions. Here we assess the impact of mitochondrial bioenergetics on neovascularisation, by deleting cox10 gene encoding an assembly factor of cytochrome c oxidase (COX) specifically in mouse ECs, providing a model for vasculature-restricted respiratory deficiency. We show that EC-specific cox10 ablation results in deficient vascular development causing embryonic lethality. In adult mice induction of EC-specific cox10 gene deletion produces no overt phenotype. However, the angiogenic capacity of COX-deficient ECs is severely compromised under energetically demanding conditions, as revealed by significantly delayed wound-healing and impaired tumour growth. We provide genetic evidence for a requirement of mitochondrial respiration in vascular endothelial cells for neoangiogenesis during development, tissue repair and cancer

    Chemotherapy-induced bone marrow nerve injury impairs hematopoietic regeneration

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    Anti-cancer chemotherapy drugs challenge hematopoietic tissues to regenerate, but commonly produce long-term sequelae. Deficits in hematopoietic stem or stromal cell function have been described, but the mechanisms mediating chemotherapy-induced hematopoietic dysfunction remain unclear. Administration of multiple cycles of cisplatin chemotherapy causes significant sensory neuropathy. Here, we demonstrate that chemotherapy-induced nerve injury in the bone marrow is a critical lesion impairing hematopoietic regeneration. We show using various pharmacological and genetic models that the selective loss of adrenergic innervation in the BM alters its regeneration following genotoxic insult. Sympathetic nerves in the marrow promote the survival of stem cell niche constituents that initiate recovery. Neuroprotection by deletion of Trp53 in sympathetic neurons or neuro-regeneration using 4-methylcatechol or glial-derived neurotrophic factor (GDNF) administration can restore hematopoietic recovery. Thus, these results shed light on the potential benefit of adrenergic nerve protection to shield hematopoietic niches from injury
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