1,228 research outputs found
Gallium-assisted diffusion bonding of stainless steel to titanium; microstructural evolution and bond strength
Strong joints between stainless steel 304L and pure titanium (grade-2) were made using the novel method of āgallium-assisted diffusion bondingā. The microstructural evolution and interfacial reactions were investigated in detail. The possible mechanisms of phase changes at the joint interface when bonding with and without a nickel interlayer were identified. Layers of FeTi and (Fe,Cr)2Ti intermetallic compounds were found at the reaction zone in the case of direct bonding, whereas (Fe,Ni)Ti and Fe2Ti phases were identified in the reaction zone of the samples bonded using nickel interlayers. A layer of Ī±Fe was observed on the steel side of the reaction zone in both the cases, probably due to the enrichment of Cr at the interface. The diffusion of gallium led to formation of a layer of Ī±Ti, while the diffusion of Fe and Ni assisted in the formation of a duplex (Ī±+Ī²)Ti phase in the inter-diffusion zone. The joints fractured along the intermetallic layers at the interface, during tensile testing, with limited ductility. The maximum tensile strengths of the bonded samples were 280 and 313 MPa with and without nickel interlayer, respectively. The latter equals 92% of the tensile strength of the pure grade-2 titanium used in this work (i.e. 340 MPa)
Variance estimation for a low-income proportion
Proportions below a given fraction of a quantile of an income distribution are often estimated from survey data in poverty comparisons. We consider the estimation of the variance of such a proportion, estimated from Family Expenditure Survey data. We show how a linearization method of variance estimation may be applied to this proportion, allowing for the effects of both a complex sampling design and weighting by a raking method to population controls. We show that, for 1998-99 data, the estimated variances are always increased when allowance is made for the design and raking weights, the principal effect arising from the design. We also study the properties of a simplified variance estimator and discuss extensions to a wider class of poverty measures
Representation of women in sport sciences research, publications, and editorial leadership positions: are we moving forward?
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Elena Martinez-Rosales was supported by the Spanish Ministry of Education (FPU18/01107) . Alba Hernandez-Martinez was supported by the Plan Propio, Gerty Cori program from the University of Almeria, Spain. Irene Esteban-Cornejo was supported by the Spanish Ministry of Economy and Competitiveness (RTI2018-095284-J-100) and the Spanish Ministry of Science and Innovation (RYC2019-027287-I) . Alberto Soriano-Maldonado was supported by the Spanish Ministry of Science, Innovation and Universities (ref. RTI2018-093302-A-I00) .Objectives: We determined the representation of women in sport sciences research leadership by assessing the
proportion of women in (i) leading authorship positions of randomized controlled trials (RCTs) published
from January 2000 to September 2020 in sport sciences journals and (ii) editorial boards of these journals as of
September 2020.
Design: Review.
Methods: We searched PubMed for RCTs published from January 1, 2000, to September 1, 2020, in a representative
sample of the top sport sciences journals and identified the sex of first and senior authors through photographs,
sex pronouns, Google Scholar, ResearchGate, institutional, or other profiles. This strategy was also used
to identify the sex of the editorial board members from the selected journals.
Results: A total of 4841 articles published in 14 journals, and 1418 editors, were analyzed. The average proportions
of female first and senior authorship were 24.8% and 16.8%, respectively. The percentage of female first authorship
increased by ~0.5% annually (Ī²=0.702; B=0.46, 95% CI=0.24 to 0.68, p < 0.001) from2000 to 2020,
while the percentage of female senior authorship did not change over time (Ī² = 0.274; B = 0.15, 95% CI =
ā0.102 to 0.398, p = 0.230). Among the editorial boards' positions, 19.7% were occupied by women. None of
the editors-in-chief of the selected journals were women.
Conclusions:Women are markedly underrepresented in leading authorship and editorial board positions in sport
sciences, despite a ~0.5% annual increase in female first authorship in the past two decades. The mechanisms underlying
these findings and the actions needed to reduce potential gender inequalities warrant further research.Spanish Government FPU18/01107University of Almeria, SpainSpanish Ministry of Economy and Competitiveness RTI2018-095284-J-100Spanish Government RYC2019-027287-ISpanish Ministry of Science, Innovation and Universities RTI2018-093302-A-I0
Are there ethnic and religious variations in uptake of bowel cancer screening?:A retrospective cohort study among 1.7 million people in Scotland
This work was supported by the Chief Scientistās Office (grant number CZH/4/878), Cancer Research UK (grant number C3743/A16594), and supplementary funding from NHS Health Scotland. ISD and National Records of Scotland both made āin-houseā contributions to the work.Objective Cancer screening should be equitably accessed by all populations. Uptake of colorectal cancer screening was examined using the Scottish Health and Ethnicity Linkage Study that links the Scottish Census 2001 to health data by individual-level self-reported ethnicity and religion. Setting Data on 1.7āmillion individuals in two rounds of the Scottish Bowel Cancer Screening Programme (2007ā2013) were linked to the 2001 Census using the Scottish Community Health Index number. Main outcome measure Uptake of colorectal cancer screening, reported as age-adjusted risk ratios (RRs) by ethnic group and religion were calculated for men and women with 95% CI. Results In the first, incidence screening round, compared with white Scottish men, Other White British (RR 109.6, 95%āCI 108.8 to 110.3) and Chinese (107.2, 95% CI 102.8 to 111.8) men had higher uptake. In contrast, men of all South Asian groups had lower uptake (Indian RR 80.5, 95% CI 76.1 to 85.1; Pakistani RR 65.9, 95% CI 62.7 to 69.3; Bangladeshi RR 76.6, 95% CI 63.9 to 91.9; Other South Asian RR 88.6, 95% CI 81.8 to 96.1). Comparable patterns were seen among women in all ethnic groups, for example, Pakistani (RR 55.5, 95% CI 52.5 to 58.8). Variation in uptake was also observed by religion, with lower rates among Hindu (RR (95%CI): 78.4 (71.8 to 85.6)), Muslim (69.5 (66.7 to 72.3)) and Sikh (73.4 (67.1 to 80.3)) men compared with the reference population (Church of Scotland), with similar variation among women: lower rates were also seen among those who reported being Jewish, Roman Catholic or with no religion. Conclusions There are important variations in uptake of bowel cancer screening by ethnic group and religion in Scotland, for both sexes, that require further research and targeted interventions.Publisher PDFPeer reviewe
Comprehensive serial analysis of gene expression of the cervical transcriptome
<p>Abstract</p> <p>Background</p> <p>More than half of the approximately 500,000 women diagnosed with cervical cancer worldwide each year will die from this disease. Investigation of genes expressed in precancer lesions compared to those expressed in normal cervical epithelium will yield insight into the early stages of disease. As such, establishing a baseline from which to compare to, is critical in elucidating the abnormal biology of disease. In this study we examine the normal cervical tissue transcriptome and investigate the similarities and differences in relation to CIN III by Long-SAGE (L-SAGE).</p> <p>Results</p> <p>We have sequenced 691,390 tags from four L-SAGE libraries increasing the existing gene expression data on cervical tissue by 20 fold. One-hundred and eighteen unique tags were highly expressed in normal cervical tissue and 107 of them mapped to unique genes, most belong to the ribosomal, calcium-binding and keratinizing gene families. We assessed these genes for aberrant expression in CIN III and five genes showed altered expression. In addition, we have identified twelve unique HPV 16 SAGE tags in the CIN III libraries absent in the normal libraries.</p> <p>Conclusion</p> <p>Establishing a baseline of gene expression in normal cervical tissue is key for identifying changes in cancer. We demonstrate the utility of this baseline data by identifying genes with aberrant expression in CIN III when compared to normal tissue.</p
Quantifying the behavior of stock correlations under market stress
Understanding correlations in complex systems is crucial in the face of turbulence, such as the ongoing financial crisis. However, in complex systems, such as financial systems, correlations are not constant but instead vary in time. Here we address the question of quantifying state-dependent correlations in stock markets. Reliable estimates of correlations are absolutely necessary to protect a portfolio. We analyze 72 years of daily closing prices of the 30 stocks forming the Dow Jones Industrial Average (DJIA). We find the striking result that the average correlation among these stocks scales linearly with market stress reflected by normalized DJIA index returns on various time scales. Consequently, the diversification effect which should protect a portfolio melts away in times of market losses, just when it would most urgently be needed. Our empirical analysis is consistent with the interesting possibility that one could anticipate diversification breakdowns, guiding the design of protected portfolios
Nonvalidated home blood pressure devices dominate the online marketplace in Australia: major implications for cardiovascular risk management
Self-home blood pressure (BP) monitoring is recommended to guide clinical decisions on hypertension and is used worldwide for cardiovascular risk management. People usually make their own decisions when purchasing BP devices, which can be made online. If patients purchase nonvalidated devices (those not proven accurate according to internationally accepted standards), hypertension management may be based on inaccurate readings resulting in under- or over-diagnosis or treatment. This study aimed to evaluate the number, type, percentage validated, and cost of home BP devices available online. A search of online businesses selling devices for home BP monitoring was conducted. Multinational companies make worldwide deliveries, so searches were restricted to BP devices available for one nation (Australia) as an example of device availability through the global online marketplace. Validation status of BP devices was determined according to established protocols. Fifty nine online businesses, selling 972 unique BP devices were identified. These included 278 upper-arm cuff devices (18.3% validated), 162 wrist-cuff devices (8.0% validated), and 532 wrist-band wearables (0% validated). Most BP devices (92.4%) were stocked by international e-commerce businesses (eg, eBay, Amazon), but only 5.5% were validated. Validated cuff BP devices were more expensive than nonvalidated devices: median (interquartile range) of 101.1 (75.0ā151.5) versus 67.4 (30.4ā112.8) Australian Dollars. Nonvalidated BP devices dominate the online marketplace and are sold at lower cost than validated ones, which is a major barrier to accurate home BP monitoring and cardiovascular risk management. Before purchasing a BP device, people should check it has been validated at https://www.stridebp.org
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