371 research outputs found

    Application of fuzzy logic and geostatistic in the analysis of the fertility of a soil under pasture

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    The objective of this research was to generate a representation of the chemical attributes of the soil, using fuzzy logic and geostatistic analysis as procedures of appropriate mapping to the representation of continuous phenomena. The area in study is located in the south of Espirito Santo state, county district of Alegre. The experiment was done in an Ultisol Yellow-Red loamy texture under cultivation of pasture Brachiaria decumbens The soil was sampled in the depth of 0-0,2 m, in the 64 points of a regular grid, with dimension of 90 x 90 m. The studied chemical attributes were K, Ca, Mg, Al. SB, T and V It took place a continuous classification (if the attributes, using the fuzzy logic The data were submitted to the descriptive analysis and, soon afterwards. the geostatistic analysis. through the semivariograms adjustment. The attributes presented moderate and high variability measured by CV. All of the attributes presented spatial dependence, demonstrated by the adjustment of the spherical and the exponential semivariogram The maps in study presented a mild representation of the limits of variation of the degrees of pertinence of the chemical attributes of the soil, turning them more representative The fuzzy logic associated to the geostatistic analysis is it suitable technique to be applied to generate a representation of soils attributes, which naturally present a gradual variation in the land.40332333

    Quantum Black Holes from Cosmic Rays

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    We investigate the possibility for cosmic ray experiments to discover non-thermal small black holes with masses in the TeV range. Such black holes would result due to the impact between ultra high energy cosmic rays or neutrinos with nuclei from the upper atmosphere and decay instantaneously. They could be produced copiously if the Planck scale is in the few TeV region. As their masses are close to the Planck scale, these holes would typically decay into two particles emitted back-to-back. Depending on the angles between the emitted particles with respect to the center of mass direction of motion, it is possible for the simultaneous showers to be measured by the detectors.Comment: 6 pages, 3 figure

    Gravitational effective action at second order in curvature and gravitational waves

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    We consider the full effective theory for quantum gravity at second order in curvature including non-local terms. We show that the theory contains two new degrees of freedom beyond the massless graviton: namely a massive spin-2 ghost and a massive scalar field. Furthermore, we show that it is impossible to fine-tune the parameters of the effective action to eliminate completely the classical spin-2 ghost because of the non-local terms in the effective action. Being a classical field, it is not clear anyway that this ghost is problematic. It simply implies a repulsive contribution to Newton’s potential. We then consider how to extract the parameters of the effective action and show that it is possible to measure, at least in principle, the parameters of the local terms independently of each other using a combination of observations of gravitational waves and measurements performed by pendulum type experiments searching for deviations of Newton’s potential

    Prevalence and correlates of frailty in an older rural African population:findings from the HAALSI cohort study

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    Background: Frailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort. Methods: We analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1–2) and frail participants (score 3+). Results: Five thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail). Conclusions: Phenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

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    SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation

    The presence of a systemic inflammatory response predicts poorer survival in patients receiving adjuvant 5-FU chemotherapy following potentially curative resection for colorectal cancer

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    There is increasing evidence that the presence of a systemic inflammatory response plays an important role in survival following curative resection for colorectal cancer. The present study evaluated the relationship between C-reactive protein concentrations and survival in a cohort of patients receiving adjuvant 5-fluorouracil (5-FU) chemotherapy following potentially curative resection for colorectal cancer. In all, 222 patients undergoing potentially curative resection for colorectal cancer were studied. Of these, 50 patients received adjuvant 5-FU-based chemotherapy. Circulating concentrations of C-reactive protein were measured prior to surgery. The minimum follow-up was 15 months; the median follow-up of the survivors was 38 months. During this period 61 patients died, 32 patients of their cancer and 29 of intercurrent disease. In those patients who did not receive adjuvant chemotherapy, age (P<0.001), Dukes stage (P<0.05) and an elevated C-reactive protein (P<0.01) were significantly associated with survival. In those patients who did receive adjuvant chemotherapy, an elevated C-reactive protein concentration (P<0.01) was significantly associated with survival. The presence of a systemic inflammatory response is an independent predictor of poor outcome in patients receiving adjuvant 5-FU-based chemotherapy following potentially curative resection for colorectal cancer

    Circulating microRNA Profiles during the Bovine Oestrous Cycle

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    Up to 50% of ovulations go undetected in modern dairy herds due to attenuated oestrus behavior and a lack of high-accuracy methods for detection of fertile oestrus. This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry. MicroRNAs (miRNAs) are ubiquitous regulators of gene expression during both health and disease and they have been shown to regulate different reproductive processes. Extracellular miRNAs are stable and can provide useful biomarkers of tissue function; changes in circulating miRNA profiles have been reported during menstrual cycles. This study sought to establish the potential of circulating miRNAs as biomarkers of oestrus in cattle. We collected plasma samples from 8 Holstein-Friesian heifers on days Days 0, 8 and 16 of an oestrous cycle and analysed small RNA populations on each Day using two independent high-throughput approaches, namely, Illumina sequencing (n = 24 samples) and Qiagen PCR arrays (n = 9 sample pools, 3-4 samples / pool). Subsequently, we used RT-qPCR (n = 24 samples) to validate the results of high-throughput analyses, as well as to establish the expression profiles of additional miRNAs previously reported to be differentially expressed during reproductive cycles. Overall, we identified four miRNAs (let-7f, miR-125b, miR-145 and miR-99a-5p), the plasma levels of which distinctly increased (up to 2.2-fold, P < 0.05) during oestrus (Day 0) relative to other stages of the cycle (Days 8 and 16). Moreover, we identified several hundred different isomiRs and established their relative abundance in bovine plasma. In summary, our results reveal the dynamic nature of plasma miRNAs during the oestrous cycle and provide evidence of the feasibility of using circulating miRNAs as biomarkers of reproductive function in livestock in the future

    Esophagitis in a High H. pylori Prevalence Area: Severe Disease Is Rare but Concomitant Peptic Ulcer Is Frequent

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    Background: Few data are available on the prevalence of erosive and severe esophagitis in Western countries. Objective: To retrospectively determine the prevalence and the factors predicting erosive esophagitis and severe esophagitis in a large series of endoscopies in Spain. Design: Retrospective observational study. A multivariate analysis was performed to determine variables predicting severe esophagitis. Setting: Databases of 29 Spanish endoscopy units. Patients: Patients submitted to a diagnostic endoscopy during the year 2005. Interventions: Retrospective review of the databases. Main Outcome Measurements: Esophagitis severity (graded according to the Los Angeles classification) and associated endoscopic findings. Results: Esophagitis was observed in 8.7% of the 93,699 endoscopies reviewed. Severe esophagitis (LA grade C or D) accounted for 22.5% of cases of the disease and was found in 1.9% of all endoscopies. Incidences of esophagitis and those of severe esophagitis were 86.2 and 18.7 cases per 100,000 inhabitants per year respectively. Male sex (OR 1.89) and advanced age (OR 4.2 for patients in the fourth age quartile) were the only variables associated with severe esophagitis. Associated peptic ulcer was present in 8.8% of cases. Limitations: Retrospective study, no data on individual proton pump inhibitors use. Conclusions: Severe esophagitis is an infrequent finding in Spain. It occurs predominantly in males and in older individuals. Peptic ulcer disease is frequently associated with erosive esophagitis

    Comprehensive analysis of blood cells and plasma identifies tissue-specific miRNAs as potential novel circulating biomarkers in cattle

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    Abstract Background The potential of circulating miRNAs as biomarkers of tissue function, both in health and disease, has been extensively demonstrated in humans. In addition, circulating miRNA biomarkers offer significant potential towards improving the productivity of livestock species, however, such potential has been hampered by the absence of information on the nature and source of circulating miRNA populations in these species. In addition, many miRNAs originally proposed as robust biomarkers of a particular tissue or disease in humans have been later shown not to be tissue specific and thus to actually have limited biomarker utility. In this study, we comprehensively analysed miRNA profiles in plasma and cell fractions of blood from cattle with the aim to identify tissue-derived miRNAs which may be useful as biomarkers of tissue function in this important food animal species. Results Using small RNA sequencing, we identified 92 miRNAs with significantly higher expression in plasma compared to paired blood cell samples (n = 4 cows). Differences in miRNA levels between plasma and cell fractions were validated for eight out of 10 miRNAs using RT-qPCR (n = 10 cows). Among miRNAs found to be enriched in plasma, we confirmed miR-122 (liver), miR-133a (muscle) and miR-215 (intestine) to be tissue-enriched, as reported for other species. Profiling of additional miRNAs across different tissues identified the human homologue, miR-802, as highly enriched specifically in liver. Conclusions These results provide novel information on the source of bovine circulating miRNAs and could significantly facilitate the identification of production-relevant tissue biomarkers in livestock. In particular, miR-802, a circulating miRNA not previously identified in cattle, can reportedly regulate insulin sensitivity and lipid metabolism, and thus could potentially provide a specific biomarker of liver function, a key parameter in the context of post-partum negative energy balance in dairy cows
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