1,500 research outputs found

    Analysis of TIG Welding Process on Mechanical Properties and Microstructure of Aa6063 Aluminum Alloy Joints

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    Present work pertains to testing of mechanical properties and microstructure of AA 6063 Aluminium alloy joints by Tungsten inert gas (TIG) welding. By varying weld current and maintaining all parameters constant hardness, impact and tensile strength of the welded joints are tested and finally, microstructure details are analyzed. The results showed mechanical properties linearly varies with increase in weld current

    Birds and people in Europe

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    At a regional scale, species richness and human population size are frequently positively correlated across space. Such patterns may arise because both species richness and human density increase with energy availability. If the species-energy relationship is generated through the 'more individuals' hypothesis, then the prediction is that areas with high human densities will also support greater numbers of individuals from other taxa. We use the unique data available for the breeding birds in Europe to test this prediction. Overall regional densities of bird species are higher in areas with more people; species of conservation concern exhibit the same pattern. Avian density also increases faster with human density than does avian biomass, indicating that areas with a higher human density have a higher proportion of small-bodied individuals. The analyses also underline the low numbers of breeding birds in Europe relative to humans, with a median of just three individual birds per person, and 4 g of bird for every kilogram of human

    Smokeless tobacco - a substantial risk for oral potentially malignant disorders in South Asia

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    Data sources: Medline, the Science Citation Index (SCI) via Web of Science, Scopus, CINAHL, Global Index Medicus, Google Scholar and SLT-related reports of the International Agency for Research on Cancer and the National Cancer Institute of the United States. Study selection: Observational studies on the use of SLT and the risk of developing OPMDs in South Asian Populations. Data extraction and synthesis: Duplicate selection of studies was undertaken with two reviewers undertaking data abstraction and quality assessment independently. Risk and odds ratios were extracted or calculated for studies where possible. Meta odds ratios (mOR) were calculated using a random effects analysis. Results: Fifteen papers reporting 18 studies were included. The majority (12) were from India. All the studies were case-control designs. MOR for any OPMD with the use of any SLT product was 15.5 (95% CI; 9.9–24.2). Risk was higher in women; mOR = 22.2 (95% CI, 9.1–54.1) than men; mOR = 8.7 (95% CI, 2.1–34.8). Betel quid with tobacco carried the highest risk for OPMD, mOR = 16.1 (95% CI, 7.8–33.5). Conclusions: The findings of our study point towards a strong association between some forms of OPMDs and SLT use in South Asia. The risk estimates are high, irrespective of controlling for confounders such as smoking and alcohol or stratification by sex, country or source of controls. There is also an exposure-response relationship between OPMDs and SLT use

    Class of self-limiting growth models in the presence of nonlinear diffusion

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    The source term in a reaction-diffusion system, in general, does not involve explicit time dependence. A class of self-limiting growth models dealing with animal and tumor growth and bacterial population in a culture, on the other hand are described by kinetics with explicit functions of time. We analyze a reaction-diffusion system to study the propagation of spatial front for these models.Comment: RevTex, 13 pages, 5 figures. To appear in Physical Review

    BMI and All-Cause Mortality in a Population-Based Cohort in Rural South Africa

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    OBJECTIVE: This study evaluates the association between BMI and all-cause and cause-specific mortality in South Africa. METHODS: Prospective, population-based observational cohort data from rural South Africa were analyzed. BMI was measured in 2010. Demographic characteristics were recorded and deaths were verified with verbal autopsy interview. The InterVA-5 tool was used to assign causes of death. HIV testing was conducted annually. Cox proportional hazards models were fit to estimate the effect of BMI on all-cause and cause-specific mortality, accounting for the competing risk of death from other causes. Models were adjusted for sociodemographic characteristics and HIV status, and inverse probability weighting for survey nonparticipation was used. RESULTS: The cohort consisted of 9,728 individuals. In adjusted models, those with BMI of 25.0 to 29.9 kg/m2 or 30.0 to 34.9 kg/m2 had a lower hazard of death (adjusted hazard ratio: 0.80; 95% CI: 0.69-0.92 and adjusted hazard ratio: 0.75; 95% CI: 0.60-0.93, respectively) compared with those with BMI of 18.5 to 24.9 kg/m^{2}. CONCLUSIONS: Individuals in South Africa who meet clinically defined criteria for overweight or obesity had a lower risk of all-cause mortality than those with a normal BMI. These findings were stronger for women and communicable conditions

    The 1991 International Energy Workshop: The Poll Results and a Review of Papers

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    The tenth annual meeting of the International Energy Workshop (IEW) was held IIASA. In addition to analyses of the IEW survey of expected crude oil prices, economic growth, primary energy consumption and production, and energy trade, this meeting featured sessions on the forthcoming establishment of the common energy market in the European Community, the prospects for the development of the energy system in the economies of the former Soviet Union and Eastern Europe, and the global environment. This report is divided into three sections. The first section presents and analyzes the latest poll results. The next section reports on the papers presented at the IEW meeting. The final section briefly summarizes the proceedings of the special session held at the meeting

    Species identification of Australian marsupials using collagen fingerprinting

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    The study of faunal remains from archaeological sites is often complicated by the presence of large numbers of highly fragmented, morphologically unidentifiable bones. In Australia, this is the combined result of harsh preservation conditions and frequent scavenging by marsupial carnivores. The collagen fingerprinting method known as zooarchaeology by mass spectrometry (ZooMS) offers a means to address these challenges and improve identification rates of fragmented bones. Here, we present novel ZooMS peptide markers for 24 extant marsupial and monotreme species that allow for genus-level distinctions between these species. We demonstrate the utility of these new peptide markers by using them to taxonomically identify bone fragments from a nineteenth-century colonial-era pearlshell fishery at Bandicoot Bay, Barrow Island. The suite of peptide biomarkers presented in this study, which focus on a range of ecologically and culturally important species, have the potential to significantly amplify the zooarchaeological and paleontological record of Australia.1. Introduction 2. Material and methods 2.1. Materials 2.1.1. Modern reference specimens 2.1.2. Archaeological specimens 2.2. Collagen extraction 2.3. Matrix-assisted laser desorption/ionization–tandem time of flight mass spectrometry 2.4. Liquid chromatography with tandem mass spectrometry 2.5. Identification and confirmation of biomarkers 3. Results 3.1. Novel ZooMS peptide markers 3.2. Marsupial versus monotreme ZooMS markers 3.3. Marsupial ZooMS markers 3.4. Using ZooMS to identify macropods 3.5. Collagen fingerprinting of archaeological specimens 4. Discussion 4.1. ZooMS insights at Bandicoot Bay 4.2. Comparison to published markers 4.3. Challenges and future prospect

    Exposure to Cerium Oxide Nanoparticles Is Associated With Activation of Mitogen-activated Protein Kinases Signaling and Apoptosis in Rat Lungs

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    Objectives: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2) nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. Methods: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline) or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. Results: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p\u3c0.05). Conclusions: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response
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