684 research outputs found

    The Shapes of Dense Cores and Bok Globules

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    The shapes of isolated Bok globules and embedded dense cores of molecular clouds are analyzed using a nonparametric method, under the alternate hypotheses that they are randomly oriented prolate objects or that they are randomly oriented oblate objects. In all cases, the prolate hypothesis gives a better fit to the data. If Bok globules are oblate, they must be very flat; the average axis ratio is b/a = 0.3, and few or no globules can have b/a > 0.7. If Bok globules are prolate, then the mean axis ratio is b/a = 0.5. For most data samples of dense cores, the randomly-oriented oblate hypothesis can be rejected at the 99% confidence level. If the dense cores are prolate, their mean axis ratio is approximately 0.4 to 0.5. Dense cores are significantly different in shape from the clouds in which they are embedded; clouds have flatter apparent shapes, and are inconsistent with a population of randomly oriented axisymmetric objects.Comment: 26 pages (LaTeX) including 8 postscript figures; to appear in Ap

    A systematic literature review of research on social procurement in the construction and infrastructure sector : barriers, enablers, and strategies

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    In Australia, a new feature of public policy is the requirement by governments that large-scale infrastructure projects integrate social procurement practices that alter the traditional focus on balancing price and quality. Social procurement has been gradually developing in practice, but the academic literature has not kept pace. Although past research has identified some of the barriers affecting social procurement implementation in the construction industry, the nature of the barriers impeding its proliferation has not to date been systematically reviewed. This paper undertakes a review of the social procurement literature published from January 2012 to 30 June 2022, with 49 papers chosen under selective criteria. This critical review employs the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) technique to retrieve secondary data on social procurement from available peer-reviewed academic papers through three databases (Scopus, EBSCOhost, Web of Science). The literature analysis focuses on three themes: (1) barriers; (2) enablers; and (3) strategies to overcome the barriers. The paper finds that social procurement as a field of practice is evolving and expanding, but its role in contributing to social value creation remains an under-theorised concept. Recommendations for practice and future research are identified, including the need to measure the real-world impacts of policy

    A systematic literature review of research on social procurement in the construction and infrastructure sector: barriers, enablers, and strategies

    Get PDF
    In Australia, a new feature of public policy is the requirement by governments that large-scale infrastructure projects integrate social procurement practices that alter the traditional focus on balancing price and quality. Social procurement has been gradually developing in practice, but the academic literature has not kept pace. Although past research has identified some of the barriers affecting social procurement implementation in the construction industry, the nature of the barriers impeding its proliferation has not to date been systematically reviewed. This paper undertakes a review of the social procurement literature published from January 2012 to 30 June 2022, with 49 papers chosen under selective criteria. This critical review employs the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) technique to retrieve secondary data on social procurement from available peer-reviewed academic papers through three databases (Scopus, EBSCOhost, Web of Science). The literature analysis focuses on three themes: (1) barriers; (2) enablers; and (3) strategies to overcome the barriers. The paper finds that social procurement as a field of practice is evolving and expanding, but its role in contributing to social value creation remains an under-theorised concept. Recommendations for practice and future research are identified, including the need to measure the real-world impacts of policy

    Exploring Alternative Futures in the Anthropocene

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    Many challenges posed by the current Anthropocene epoch require fundamental transformations to humanity’s relationships with the rest of the planet. Achieving such transformations requires that humanity improve its understanding of the current situation and enhance its ability to imagine pathways toward alternative, preferable futures. We review advances in addressing these challenges that employ systematic and structured thinking about multiple possible futures (futures-thinking). Over seven decades, especially the past two, approaches to futures-thinking have helped people from diverse backgrounds reach a common understanding of important issues, underlying causes, and pathways toward optimistic futures. A recent focus has been the stimulation of imagination to produce new options. The roles of futures-thinking in breaking unhelpful social addictions and in conflict resolution are key emerging topics. We summarize cognitive, cultural, and institutional constraints on the societal uptake of futures-thinking, concluding that none are insurmountable once understood

    Genetic variability, chemotype distribution, and aggressiveness of Fusarium culmorum on durum wheat in Tunisia

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    Fusarium culmorum is the most commonly reported root rot pathogen in Tunisian durum wheat. Isolates of the pathogen from four durum wheat growing areas in the north of Tunisia were analyzed for their chemotypes. Two chemotypes were detected at unequal abundance (96% of 3-ADON and 4% of NIV). Distribution of a SNP mutation located at the position 34 bp after the first exon of the EF-1α partial sequence was analysed, to verify whether the haplotype was specifically associated to Fusarium root rot. A and T haplotypes were homogeneously distributed in three different Tunisian regions (Mateur, Beja and Bousalem) but not for the region of Bizerte, from which greatest number of A haplotype strains were detected. The isolates were tested for their virulence under glasshouse conditions, and a mean of 91% of crown and root infection was observed. Chemotype influenced virulence, but there was no significant influence of the geographical origin or haplotype on virulence. The distribution of three inter simple sequence repeats (ISSR) was examined, to better understand the structure of F. culmorum populations in Tunisia. A total of 27 fragments were obtained with eight polymorphic bands. Cluster analysis showed a high level of similarity between isolates. Analysis of molecular variance confirmed that there was little genetic differentiation among F. culmorum strains from different locations

    Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to alpha-aminoadipic semialdehyde dehydrogenase deficiency

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    Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability. To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy. These lysine-reduction therapies have resulted in improved biochemical parameters and cognitive development in many but not all patients. The goal of these consensus guidelines is to re-evaluate and update the two previously published recommendations for diagnosis, treatment, and follow-up of patients with PDE-ALDH7A1. Members of the International PDE Consortium initiated evidence and consensus-based process to review previous recommendations, new research findings, and relevant clinical aspects of PDE-ALDH7A1. The guideline development group included pediatric neurologists, biochemical geneticists, clinical geneticists, laboratory scientists, and metabolic dieticians representing 29 institutions from 16 countries. Consensus guidelines for the diagnosis and management of patients with PDE-ALDH7A1 are provided. This article is protected by copyright. All rights reserved

    Association of genetic variation with systolic and diastolic blood pressure among African Americans: the Candidate Gene Association Resource study

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    The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexit

    New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

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    To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P<5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    The genetic architecture of type 2 diabetes

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    The genetic architecture of common traits, including the number, frequency, and effect sizes of inherited variants that contribute to individual risk, has been long debated. Genome-wide association studies have identified scores of common variants associated with type 2 diabetes, but in aggregate, these explain only a fraction of heritability. To test the hypothesis that lower-frequency variants explain much of the remainder, the GoT2D and T2D-GENES consortia performed whole genome sequencing in 2,657 Europeans with and without diabetes, and exome sequencing in a total of 12,940 subjects from five ancestral groups. To increase statistical power, we expanded sample size via genotyping and imputation in a further 111,548 subjects. Variants associated with type 2 diabetes after sequencing were overwhelmingly common and most fell within regions previously identified by genome-wide association studies. Comprehensive enumeration of sequence variation is necessary to identify functional alleles that provide important clues to disease pathophysiology, but large-scale sequencing does not support a major role for lower-frequency variants in predisposition to type 2 diabetes
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