400 research outputs found
Seminal quality, testicle and epididymis morphology of bulls fed a diet containing gossypol
The objective was to evaluate the effect of intake of free gossypol on sperm quality and morphology of the testicles and epididymis of Nelore bulls. Twelve bulls were fed diets containing 3.3g of free gossypol/bull/day (cottonseed) (Group 1, n = 6) and a diet free of gossypol (Group 2, n = 6), respectively. Semen samples were collected in the beginning and end of the experiment which lasted 73 days. In the end of the study the testes and epididymis of bulls were removed to study the effect of free gossypol on histological characteristics. The average consumption of 3.3g of free gossypol/bull/day (mean 7.1mg of free gossypol/kg/day) reduced motility and sperm concentration and increased the percentage of major and total sperm defects, as well as the animals showing testes with seminiferous tubules of smaller thickness, fewer layers of spermatogenic lineage cells, smaller epididymal epithelium thickness and smaller number of sperm within the epididymal ducts, compared to animals with a diet free of gossypol (Group 2). The consumption of 3.3g of free gossypol/bull/day led to changes in morphology and morphometry of the testes and epididymis and reduced sperm quality of bulls.Objetivou-se avaliar o efeito da ingestão de gossipol livre sobre a qualidade espermática e a morfologia dos testículos e dos epidídimos de touros da raça Nelore. Doze touros receberam dieta contendo 3,3g de gossipol livre/touro/dia (caroço de algodão) (Grupo 1, n=6) e dieta isenta de gossipol (Grupo 2, n=6), respectivamente. Foram realizadas coletas de sêmen no início e no final do experimento, que teve duração de 73 dias. Ao final do estudo, foram retirados os testículos e os epidídimos dos touros para se estudar o efeito do gossipol livre sobre as características histológicas. O consumo médio de 3,3g de gossipol livre/touro/dia (média 7,1mg de gossipol livre/kg/dia) reduziu a motilidade e a concentração espermática e aumentou a porcentagem de defeitos espermáticos maiores e totais. Além disso, os animais apresentaram testículos com túbulos seminíferos de menor espessura de parede, menor número de camadas de células espermatogênicas, menor espessura do epitélio epididimário e menor número de espermatozoide no interior dos ductos epidídimários, em relação aos animais com dieta isenta de gossipol (Grupo 2). O consumo de 3,3g de gossipol livre/touro/dia acarretou alterações na morfologia e na morfometria dos testículos e dos epidídimos e reduziu a qualidade espermática dos touros.Universidade de Cuiabá Faculdade de Medicina VeterináriaUFMS Faculdade de Medicina Veterinária e ZootecniaEpamigUniversidade Federal do Mato GrossoUNIFESP-EPMUNIFESP, EPMSciEL
Simulating Growth and Competition on Wet and Waterlogged Soils in a Forest Landscape Model
Changes in CO2 concentration and climate are likely to alter disturbance regimes and competitive outcomes among tree species, which ultimately can result in shifts of species and biome boundaries. Such changes are already evident in high latitude forests, where waterlogged soils produced by topography, surficial geology, and permafrost are an important driver of forest dynamics. Predicting such effects under the novel conditions of the future requires models with direct and mechanistic links of abiotic drivers to growth and competition. We enhanced such a forest landscape model (PnET-Succession in LANDIS-II) to allow simulation of waterlogged soils and their effects on tree growth and competition. We formally tested how these modifications alter water balance on wetland and permafrost sites, and their effect on tree growth and competition. We applied the model to evaluate its promise for mechanistically simulating species range expansion and contraction under climate change across a latitudinal gradient in Siberian Russia. We found that higher emissions scenarios permitted range expansions that were quicker and allowed a greater diversity of invading species, especially at the highest latitudes, and that disturbance hastened range shifts by overcoming the natural inertia of established ecological communities. The primary driver of range advances to the north was altered hydrology related to thawing permafrost, followed by temperature effects on growth. Range contractions from the south (extirpations) were slower and less tied to emissions or latitude, and were driven by inability to compete with invaders, or disturbance. An important non-intuitive result was that some extant species were killed off by extreme cold events projected under climate change as greater weather extremes occurred over the next 30 years, and this had important effects on subsequent successional trajectories. The mechanistic linkages between climate and soil water dynamics in this forest landscape model produced tight links between climate inputs, physiology of vegetation, and soils at a monthly time step. The updated modeling system can produce high quality projections of climate impacts on forest species range shifts by accounting for the interacting effects of CO2 concentration, climate (including longer growing seasons), seed dispersal, disturbance, and soil hydrologic properties
Thoracic Aortic Calcium Versus Coronary Artery Calcium for the Prediction of Coronary Heart Disease and Cardiovascular Disease Events
ObjectivesThis study compared the ability of coronary artery calcium (CAC) and thoracic aortic calcium (TAC) to predict coronary heart disease (CHD) and cardiovascular disease (CVD) events.BackgroundCoronary artery calcium has been shown to strongly predict CHD and CVD events, but it is unknown whether TAC, also measured within a single cardiac computed tomography (CT) scan, is of further value in predicting events.MethodsA total of 2,303 asymptomatic adults (mean age 55.7 years, 38% female) with CT scans were followed up for 4.4 years for CHD (myocardial infarction, cardiac death, or late revascularizations) and CVD (CHD plus stroke). Cox regression, adjusted for Framingham risk score (FRS), examined the relation of Agatston CAC and TAC categories, and log-transformed CAC and TAC with the incidence of CHD and CVD events and receiver-operator characteristic (ROC) curves tested whether TAC improved prediction of events over CAC and FRS.ResultsA total of 53% of subjects had Agatston CAC scores of 0; 8% 1 to 9; 19% 10 to 99; 12% 100 to 399; and 8% ≥400. For TAC, proportions were 69%, 5%, 12%, 8%, and 7%, respectively; 41 subjects (1.8%) experienced CHD and 47 (2.0%) CVD events. The FRS-adjusted hazard ratios (HR) across increasing CAC groups (relative to <10) ranged from 3.7 (p = 0.04) to 19.6 (p < 0.001) for CHD and from 2.8 (p = 0.07) to 13.1 (p < 0.001) for CVD events; only TAC scores of 100 to 399 predicted CHD and CVD (HR: 3.0, p = 0.008, and HR: 2.3, p = 0.04, respectively); these risks were attenuated after accounting for CAC. Findings were consistent when using log-transformed CAC and TAC Agatston and volume scores. The ROC curve analyses showed CAC predicted CHD and CVD events over FRS alone (p < 0.01); however, TAC did not further add to predicting events over FRS or CAC.ConclusionsThis study found that CAC, but not TAC, is strongly related to CHD and CVD events. Moreover, TAC does not further improve event prediction over CAC
Making Climate Change Mitigation and Adaptability Real in Africa with Conservation Agriculture
In this report, the authors have gathered essential information on how the agricultural sector can respond to climate change through Conservation Agriculture (CA). This document aims to serve as a basis for decision-making based on science and agricultural experimentation in Africa
Fine Control of In Vivo Magnetic Hyperthermia Using Iron Oxide Nanoparticles with Different Coatings and Degree of Aggregation
High prevalence of impaired awareness of hypoglycemia and severe hypoglycemia among people with insulin-treated type 2 diabetes: The Dutch Diabetes Pearl Cohort
Objective People with type 2 diabetes on insulin are at risk for hypoglycemia. Recurrent hypoglycemia can cause impaired awareness of hypoglycemia (IAH), and increase the risk for severe hypoglycemia. The aim of this study was to assess the prevalence and determinants of self-reported IAH and severe hypoglycemia in a Dutch nationwide cohort of people with insulin-treated type 2 diabetes. Research design and methods Observational study of The Dutch Diabetes Pearl, a cohort of people with type 2 diabetes treated in primary, secondary and tertiary diabetes care centers. The presence of IAH and the occurrence of severe hypoglycemia in the past year, defined as an event requiring external help to re
Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry
Introduction: We aimed to evaluate if prior oral anticoagulation (OAC) and its type determines a greater risk of symptomatic hemorrhagic transformation in patients with acute ischemic stroke (AIS) subjected to mechanical thrombectomy. Materials and
Methods: Consecutive patients with AIS included in the prospective reperfusion registry NORDICTUS, a network of tertiary stroke centers in Northern Spain, from January 2017 to December 2019 were included. Prior use of oral anticoagulants, baseline variables, and international normalized ratio (INR) on admission were recorded. Symptomatic intracranial hemorrhage (sICH) was the primary outcome measure. Secondary outcome was the relation between INR and sICH, and we evaluated mortality and functional outcome at 3 months by modified Rankin scale. We compared patients with and without previous OAC and also considered the type of oral anticoagulants.
Results: About 1.455 AIS patients were included, of whom 274 (19%) were on OAC, 193 (70%) on vitamin K antagonists (VKA), and 81 (30%) on direct oral anticoagulants (DOACs). Anticoagulated patients were older and had more comorbidities. Eighty-one (5.6%) developed sICH, which was more frequent in the VKA group, but not in DOAC group. OAC with VKA emerged as a predictor of sICH in a multivariate regression model (OR, 1.89 [95% CI, 1.01–3.51], p = 0.04) and was not related to INR level on admission. Prior VKA use was not associated with worse outcome in the multivariate regression model nor with mortality at 3 months.
Conclusions: OAC with VKA, but not with DOACs, was an independent predictor of sICH after mechanical thrombectomy. This excess risk was associated neither with INR value by the time thrombectomy was performed, nor with a worse functional outcome or mortality at 3 months
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
- …