1,864 research outputs found

    Damage avoidance design steel beam-column moment connection using high-force-to-volume dissipators

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    Existing welded steel moment frames are designed to tolerate substantial yielding and plastic rotation under earthquake loads. This sacrificial design approach can lead to permanent, and often irreparable damage when interstory drifts exceed 2%. The experimental seismic performance of a 50% full-scale damage avoidance designed structural steel beam-column connection is presented. The beam-column joint region consists of a top flange-hung beam connected to the column by an angle bracket. High-force-to-volume (HF2V) devices are attached from the column to the beam to provide joint rigidity and energy dissipation as the joint opens and closes. The HF2V devices are connected either below the beam flange or concealed above the beam's lower flange. Reversed cyclic lateral load tests are conducted with drift amplitudes up to 4%. No damage is observed in the principal beam and column structural elements. The need for stiff device connections to achieve optimal device performance is demonstrated, and potential design solutions presented. Stable hysteresis and repeatable energy dissipation for a large number of cycles up to the 4% drift level is observed. It is concluded that superior and repeatable energy dissipation without damage can be achieved for every dynamic motion cycle, in contrast to conventional sacrificially designed welded moment frame connections

    Drawing inferences for high‐dimensional linear models: A selection‐assisted partial regression and smoothing approach

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    Drawing inferences for high‐dimensional models is challenging as regular asymptotic theories are not applicable. This article proposes a new framework of simultaneous estimation and inferences for high‐dimensional linear models. By smoothing over partial regression estimates based on a given variable selection scheme, we reduce the problem to low‐dimensional least squares estimations. The procedure, termed as Selection‐assisted Partial Regression and Smoothing (SPARES), utilizes data splitting along with variable selection and partial regression. We show that the SPARES estimator is asymptotically unbiased and normal, and derive its variance via a nonparametric delta method. The utility of the procedure is evaluated under various simulation scenarios and via comparisons with the de‐biased LASSO estimators, a major competitor. We apply the method to analyze two genomic datasets and obtain biologically meaningful results.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151307/1/biom13013.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151307/2/biom13013-sup-0001-SuppData.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151307/3/biom13013_am.pd

    Stillbirth and loss: family practices and display

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    This paper explores how parents respond to their memories of their stillborn child over the years following their loss. When people die after living for several years or more, their family and friends have the residual traces of a life lived as a basis for an identity that may be remembered over a sustained period of time. For the parent of a stillborn child there is no such basis and the claim for a continuing social identity for their son or daughter is precarious. Drawing on interviews with the parents of 22 stillborn children, this paper explores the identity work performed by parents concerned to create a lasting and meaningful identity for their child and to include him or her in their families after death. The paper draws on Finch's (2007) concept of family display and Walter's (1999) thesis that links continue to exist between the living and the dead over a continued period. The paper argues that evidence from the experience of stillbirth suggests that there is scope for development for both theoretical frameworks

    The prevalence of vitamin B12 deficiency in a random sample from the Australian population

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     Objective: Vitamin B12 deficiency is common in older adults, and may increase the risk of cognitive impairment. The distribution of vitamin B12 insufficiency in younger age groups is less studied. This study aims to assess the prevalence of vitamin B12 deficiency (<156ρmol/L) and subclinical low-normal levels (156-250ρmol/L) in a large, random sample of the Australian population across the adult life span. Methods: We examined serum vitamin B12 levels in a random sample of 1,085 men and 1,125 women aged 20-97 years between 1994 and 2006; in the Barwon Statistical Division, a regional area in south eastern Australia that is representative of the socioeconomic status of the Australian population. Results: The age-standardised prevalence of vitamin B12 deficiency in this cohort of men and women was 3.6%. Subclinical low-normal vitamin B12 levels (156-250ρmol/L) were found in 26%. Serum vitamin B12 levels declined with age among men (p-value <0.001) and were lower in men than women (p-value <0.001). Vitamin B12 levels were higher among supplement users (8.0% of the cohort). Conclusions: Vitamin B12 levels decline with age, and have been associated with neurodegenerative diseases and cognitive decline. Early intervention by diet education or supplement use to address this age-associated decline in vitamin levels may be an effective strategy to prevent decline in a significant segment of the population. Such intervention may need to start in mid-life (from 50-years of age) before the onset age-related decline in vitamin B12 levels

    The influence of environmental forcing on biodiversity and extinction in a resource competition model

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    In this paper, we study a model of many species that compete, directly or indirectly, for a pool of common resources under the influence of periodic, stochastic, and/or chaotic environmental forcing. Using numerical simulations, we find the number and sequence of species going extinct when the community is initially packed with a large number of species of random initial densities. Thereby, any species with a density below a given threshold is regarded to be extinct

    Dietary energy density and adiposity: employing bias adjustments in a meta-analysis of prospective studies.

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    BACKGROUND: Dietary studies differ in design and quality making it difficult to compare results. This study quantifies the prospective association between dietary energy density (DED) and adiposity in children using a meta-analysis method that adjusts for differences in design and quality through eliciting and incorporating expert opinion on the biases and their uncertainty. METHOD: Six prospective studies identified by a previous systematic literature search were included. Differences in study quality and design were considered respectively as internal and external biases and captured in bias checklists. Study results were converted to correlation coefficients; biases were considered either additive or proportional on this scale. The extent and uncertainty of the internal and external biases in each study were elicited in a formal process by five quantitatively-trained assessors and five subject-matter specialists. Biases for each study were combined across assessors using median pooling and results combined across studies by random-effects meta-analysis. RESULTS: The unadjusted combined correlation between DED and adiposity change was 0.06 (95%CI 0.01, 0.11; p = 0.013), but with considerable heterogeneity (I² = 52%). After bias-adjustment the pooled correlation was 0.17 (95%CI - 0.11, 0.45; p = 0.24), and the studies were apparently compatible (I² = 0%). CONCLUSIONS: This method allowed quantitative synthesis of the prospective association between DED and adiposity change in children, which is important for the development of evidence-informed policy. Bias adjustment increased the magnitude of the positive association but the widening confidence interval reflects the uncertainty of the assessed biases and implies that higher quality studies are required.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    The fossil insect assemblage associated with the Toarcian (Lower Jurassic) oceanic anoxic event from Alderton Hill, Gloucestershire, UK

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    Extreme global warming and environmental changes associated with the Toarcian (Lower Jurassic) Oceanic Anoxic Event (T-OAE, ∼183 Mya) profoundly impacted marine organisms and terrestrial plants. Despite the exceptionally elevated abundances of fossil insects from strata of this age, only assemblages from Germany and Luxembourg have been studied in detail. Here, we focus on the insect assemblage found in strata recording the T-OAE at Alderton Hill, Gloucestershire, UK, where <15% of specimens have previously been described. We located all known fossil insects (n = 370) from Alderton Hill, and used these to create the first comprehensive taxonomic and taphonomic analysis of the entire assemblage. We show that a diverse palaeoentomofaunal assemblage is preserved, comprising 12 orders, 21 families, 23 genera and 21 species. Fossil disarticulation is consistent with insect decay studies. The number of orders is comparable with present-day assemblages from similar latitudes (30°-40°N), including the Azores, and suggests that the palaeoentomofauna reflects a life assemblage. At Alderton, Hemiptera, Coleoptera and Orthoptera are the commonest (56.1%) orders. The high abundance of Hemiptera (22.1%) and Orthoptera (13.4%) indicates well-vegetated islands, while floral changes related to the T-OAE may be responsible for hemipteran diversification. Predatory insects are relatively abundant (∼10% of the total assemblage) and we hypothesise that the co-occurrence of fish and insects within the T-OAE represents a jubilee-like event. The marginally higher proportion of sclerotised taxa compared to present-day insect assemblages possibly indicates adaptation to environmental conditions or taphonomic bias. The coeval palaeoentomofauna from Strawberry Bank, Somerset is less diverse (9 orders, 12 families, 6 genera, 3 species) and is taphonomically biased. The Alderton Hill palaeoentomofauna is interpreted to be the bestpreserved and most representative insect assemblage from Toarcian strata in the UK. This study provides an essential first step towards understanding the likely influence of the TOAE on insects

    A Phase II Study of Venetoclax in Combination With Pomalidomide and Dexamethasone in Relapsed/Refractory Multiple Myeloma

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    © 2021 The Authors.[Background]: Venetoclax is a selective BCL-2 inhibitor with clinical activity in relapsed/refractory multiple myeloma (RRMM). Combinations of venetoclax with agents that have complementary mechanisms of action may improve venetoclax efficacy in RRMM. This study evaluated venetoclax with pomalidomide and dexamethasone (VenPd) in RRMM. [Patients and Methods]: This phase II open label study (NCT03567616) evaluated VenPd in patients with RRMM who had received ≥ 1 prior therapy and were refractory to lenalidomide. Venetoclax was administered orally daily for days 1 to 28, pomalidomide was administered orally daily for days 1 to 21, and dexamethasone was administered weekly for each 28-day cycle. The primary objective was to characterize the safety and tolerability of VenPd. The secondary objectives were to evaluate the efficacy and pharmacokinetics. The study was terminated early due to partial clinical hold and decision to pursue biomarker driven strategy. [Results]: Eight patients were enrolled. Patients had a median age of 67.5 years. All patients received 400 mg venetoclax; 4 patients experienced dose-limiting toxicities and the dose was not escalated. All patients had a grade ≥ 3 adverse event, and the most common was neutropenia (n = 6); cytopenias were the most prevalent adverse events. Five patients (63%) had a confirmed response, and the median duration of response was 12.9 months. The median progression-free survival was 10.5 months. [Conclusions]: Given the limited enrollment, no clear safety or efficacy conclusions about VenPd can be drawn. Preliminary safety data, particularly the occurrence of cytopenias, can be used to guide dosing strategies for future combinations of venetoclax with immunomodulatory agents.AbbVie Inc is a private corporation, and funding is not associated with a grant number. Funding information is correct as stated
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