956 resultados para background checks
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ABSTRACT Soil contamination by heavy metals threatens ecosystems and human health. Environmental monitoring bodies need reference values for these contaminants to assess the impacts of anthropogenic activities on soil contamination. Quality reference values (QRVs) reflect the natural concentrations of heavy metals in soils without anthropic interference and must be regionally established. The aim of this study was to determine the natural concentrations and quality reference values for the metals Ag, Ba, Cd, Co, Cu, Cr, Mo, Ni, Pb, Sb and Zn in soils of Paraíba state, Brazil. Soil samples were collected from 94 locations across the state in areas of native vegetation or with minimal anthropic interference. The quality reference values (QRVs) were (mg kg-1): Ag (<0.53), Ba (117.41), Cd (0.08), Co (13.14), Cu (20.82), Cr (48.35), Mo (0.43), Ni (14.44), Sb (0.61), Pb (14.62) and Zn (33.65). Principal component analysis grouped the metals Cd, Cr, Cu, Ni, Pb and Sb (PC1); Ag (PC2); and Ba, Co, Fe, Mn and Zn (PC3). These values were made official by Paraíba state through Normativa Resolution 3602/2014.
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Background and Aims The frequency at which males can be maintained with hermaphrodites in androdioecious populations is predicted to depend on the selfing rate, because self-fertilization by hermaphrodites reduces prospective siring opportunities for males. In particular, high selfing rates by hermaphrodites are expected to exclude males from a population. Here, the first estimates are provided of the mating system from two wild hexaploid populations of the androdioecious European wind-pollinated plant M. annua with contrasting male frequencies.Methods Four diploid microsatellite loci were used to genotype 19-20 progeny arrays from two populations of M. annua, one with males and one without. Mating-system parameters were estimated using the program MLTR.Key Results Both populations had similar, intermediate outcrossing rates (t(m) = 0.64 and 0.52 for the population with and without males, respectively). The population without males showed a lower level of correlated paternity and biparental inbreeding and higher allelic richness and gene diversity than the population with males.Conclusions The results demonstrate the utility of new diploid microsatellite loci for mating system analysis in a hexaploid plant. It would appear that androdioecious M. annua has a mixed-mating system in the wild, an uncommon finding for wind-pollinated species. This study sets a foundation for future research to assess the relative importance of the sexual system, plant-density variation and stochastic processes for the regulation of male frequencies in M. annua over space and time.
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The aim of this study is to contribute to a better understanding of the risk factors associated with school burnout, which has recently been described as a syndrome of emotional exhaustion due to school demands, cynical and detached attitude towards school and feelings of inadequacy as a student (Salmela-Aro, Kiuru, Pietikainen & Jokela, 2008a). The research focuses on students in the last years of compulsory schooling, period in which burnout has not received much attention yet. A total of 342 adolescents (Mean age = 14.84) were asked to complete questionnaires about school burnout, school-related stress and background variables. The results showed differences in school burnout by gender, grade level and school track, with girls, last grade of compulsory school and high-track classes, showing the highest scores. No difference was observed with respect to grade retention. Several types of school stress were identified, with stress type Success related to pressures to succeed and concerns about the academic future being the highest. Finally, stress and burnout were strongly and positively correlated, and the type of stress Success was the best predictor of overall Burnout, Exhaustion and Inadequacy dimension scores. The results are discussed in relation to their theoretical relevance and implications for the prevention of school burnout in adolescents.
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Fonaments: La hipertensió és una malaltia crònica amb alta prevalença al món. Els estils de vidasaludables es relacionen directament amb aquesta patologia pel que el rol de la infermeria és clauen el desenvolupament d'eines i intervencions per millorar l'autocontrol dels pacients hipertensosmitjançant l'educació sanitària.Objectiu: És valorar l'eficàcia de les intervencions en consultes d'infermera per a l'autocontrol dela tensió arterial en pacients amb hipertensió arterial respecte al seguiment habitual d'aquestspacients en consultes mèdiques.Mètode: S'estudiaran a 34 adults hipertensos mitjançant un assaig clínic aleatoritzat en dos grupsde 17 pacients hipertensos. El grup experimental serà objecte d'unes intervencions educativessobre la hipertensió i la repercussió dels estils de vida pel control d'aquesta patologia per partd'infermeria, a més a més, d'un control rutinari mèdic. Mentre que el grup control solamentassistirà als controls rutinaris mèdics sobre la hipertensió i no rebrà intervencions infermeres. Enl'avaluació de les dades es tindran en compte les variables de la mesura de la tensió arterial, ladieta, l'exercici físic i el seguiment del tractament, a més de diferents variablessociodemogràfiques com són l'edat, el gènere i el nivell socioeconòmic. Les dades s'analitzaranmitjançant Chi Cuadrat per a les variables qualitatives, la Correlació de Pearson i la de Spearmanper a les variables quantitatives i, finalment, la T de Student per a la comparació de la mitja de lesdues mostres independents.Conclusió: Amb l'assaig clínic es pretés demostrar que les intervencions d’infermeria en consultesmilloren l'autocontrol dels pacients amb hipertensió arterial, és a dir, són eficaces.
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A dual model with a nonlinear proton Regge trajectory in the missing mass (M_X^2) channel is constructed. A background based on a direct-channel exotic trajectory, developed and applied earlier for the inclusive electron-proton cross section description in the nucleon resonance region, is used. The parameters of the model are determined from the extrapolations to earlier experiments. Predictions for the low-mass (2 < M_X^2 < 8GeV^2) diffraction dissociation cross sections at the LHC energies are given.
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Mice with homologous disruption of the gene coding for the ligand-binding chain of the interferon (IFN) gamma receptor and derived from a strain genetically resistant to infection with Leishmania major have been used to study further the role of this cytokine in the differentiation of functional CD4+ T cell subsets in vivo and resistance to infection. Wild-type 129/Sv/Ev mice are resistant to infection with this parasite, developing only small lesions, which resolve spontaneously within 6 wk. In contrast, mice lacking the IFN-gamma receptor develop large, progressing lesions. After infection, lymph nodes (LN) and spleens from both wild-type and knockout mice showed an expansion of CD4+ cells producing IFN-gamma as revealed by measuring IFN-gamma in supernatants of specifically stimulated CD4+ T cells, by enumerating IFN-gamma-producing T cells, and by Northern blot analysis of IFN-gamma transcripts. No biologically active interleukin (IL) 4 was detected in supernatants of in vitro-stimulated LN or spleen cells from infected wild-type or deficient mice. Reverse transcription polymerase chain reaction analysis with primers specific for IL-4 showed similar IL-4 message levels in LN from both types of mice. The IL-4 message levels observed were comparable to those found in similarly infected C57BL/6 mice and significantly lower than the levels found in BALB/c mice. Anti-IFN-gamma treatment of both types of mice failed to alter the pattern of cytokines produced after infection. These data show that even in the absence of IFN-gamma receptors, T helper cell (Th) 1-type responses still develop in genetically resistant mice with no evidence for the expansion of Th2 cells.
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BACKGROUND: Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection. METHODS: In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis. Using the Metabochip, we genotyped 1875 HIV-positive, white individuals enrolled in 24 HIV observational studies, including 571 participants with a first CAD event during the 9-year study period and 1304 controls matched on sex and cohort. RESULTS: A genetic risk score built from 23 CAD-associated SNPs contributed significantly to CAD (P = 2.9 × 10(-4)). In the final multivariable model, participants with an unfavorable genetic background (top genetic score quartile) had a CAD odds ratio (OR) of 1.47 (95% confidence interval [CI], 1.05-2.04). This effect was similar to hypertension (OR = 1.36; 95% CI, 1.06-1.73), hypercholesterolemia (OR = 1.51; 95% CI, 1.16-1.96), diabetes (OR = 1.66; 95% CI, 1.10-2.49), ≥ 1 year lopinavir exposure (OR = 1.36; 95% CI, 1.06-1.73), and current abacavir treatment (OR = 1.56; 95% CI, 1.17-2.07). The effect of the genetic risk score was additive to the effect of nongenetic CAD risk factors, and did not change after adjustment for family history of CAD. CONCLUSIONS: In the setting of HIV infection, the effect of an unfavorable genetic background was similar to traditional CAD risk factors and certain adverse antiretroviral exposures. Genetic testing may provide prognostic information complementary to family history of CAD.
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Les plantes transgèniques són una part integral de l’agricultura contemporània. Durant l’any 2006 més de noranta milions d’hectàrees de plantes transgèniques van ser cultivades en vint-i-un països. Des de la comercialització de la primera planta transgènica el 1996 els nivells d’adopció d’aquests cultius han augmentat anualment amb percentatges de dos dígits. El desenvolupament i la comercialització de les plantes transgèniques van lligats estretament al comerç mundial, a la globalització, a la disponibilitat de suficient menjar, a la protecció del medi ambient i del consumidor i a la propietat intel·lectual. En aquest article exposem els avenços més recents i les tendències actuals en el desenvolupament dels cultius transgènics i de la seva utilització. També ens fem ressò d’alguns assumptes no científics que s’han de solucionar abans que aquests cultius arribin al màxim del seu potencial, proporcionant una agricultura més sostenible i ecològica. Finalment, ressaltarem la importància de com les plantes transgèniques poden contribuir en la disponibilitat de menjar i en la millora de la pobresa en els països en vies de desenvolupament.
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BACKGROUND: Diabetes represents an increasing health burden worldwide. In 2010, the Public Health Department of the canton of Vaud (Switzerland) launched a regional diabetes programme entitled "Programme cantonal Diabète" (PcD), with the objectives to both decrease the incidence of diabetes and improve care for patients with diabetes. The cohort entitled CoDiab-VD emerged from that programme. It specifically aimed at following quality of diabetes care over time, at evaluating the coverage of the PcD within this canton and at assessing the impact of the PcD on care of patients with diabetes. METHODS/DESIGN: The cohort CoDiab-VD is a prospective population-based cohort study. Patients with diabetes were recruited in two waves (autumn 2011--summer 2012) through community pharmacies. Eligible participants were non-institutionalised adult patients (≥ 18 years) with diabetes diagnosed for at least one year, residing in the canton of Vaud and coming to a participating pharmacy with a diabetes-related prescription. Women with gestational diabetes, people with obvious cognitive impairment or insufficient command of French were not eligible. Self-reported data collected, included the following primary outcomes: processes-of-care indicators (annual checks) and outcomes of care such as HbA1C, (health-related) quality of life measures (Short Form-12 Health Survey--SF-12, Audit of Diabetes-Dependent Quality of Life 19--ADDQoL) and Patient Assessment of Chronic Illness Care (PACIC). Data on diabetes, health status, healthcare utilisation, health behaviour, self-management activities and support, knowledge of, or participation to, campaigns/activities proposed by the PcD, and socio-demographics were also obtained. For consenting participants, physicians provided few additional pieces of information about processes and laboratory results. Participants will be followed once a year, via a mailed self-report questionnaire. The core of the follow-up questionnaires will be similar to the baseline one, with the addition of thematic modules adapting to the development of the PcD. Physicians will be contacted every 2 years. DISCUSSION: CoDiab-VD will allow obtaining a broad picture of the care of patients with diabetes, as well as their needs regarding their chronic condition. The data will be used to evaluate the PcD and help prioritise targeted actions. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov, identifier NCT01902043, July 9, 2013.
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Expression control in synthetic genetic circuitry, for example, for construction of sensitive biosensors, is hampered by the lack of DNA parts that maintain ultralow background yet achieve high output upon signal integration by the cells. Here, we demonstrate how placement of auxiliary transcription factor binding sites within a regulatable promoter context can yield an important gain in signal-to-noise output ratios from prokaryotic biosensor circuits. As a proof of principle, we use the arsenite-responsive ArsR repressor protein from Escherichia coli and its cognate operator. Additional ArsR operators placed downstream of its target promoter can act as a transcription roadblock in a distance-dependent manner and reduce background expression of downstream-placed reporter genes. We show that the transcription roadblock functions both in cognate and heterologous promoter contexts. Secondary ArsR operators placed upstream of their promoter can also improve signal-to-noise output while maintaining effector dependency. Importantly, background control can be released through the addition of micromolar concentrations of arsenite. The ArsR-operator system thus provides a flexible system for additional gene expression control, which, given the extreme sensitivity to micrograms per liter effector concentrations, could be applicable in more general contexts.