Effects of heat stress on milk yield of primiparous Holstein cows at regional scale using large data bases

With the prospects of global warming, heat stress, the depressive (summer) heat effect on milk yield, has become a high priority research problem in temperate zones. The effect of summer present day heat and lag heat effects on milk yield of first lactation grazing Holstein cows was assessed through the temperature and humidity index (THI). Additionally, THI thresholds were calculated. Daily air temperature and humidity data from three locations for six summer seasons (December-March in years 2001 – 2006) were used. Data of 35500 monthly test days from 8875 cows in 54 farms within the influence zones of the respective meteorological stations were analyzed. Mixed linear models were adjusted, considering the animal as random effect and location, farm, days in milking, age at calving, year of calving and THI as fixed effects. Four measures per animal were taken into account and modelled as repeated measures. A significant depressing heat effect on milk yield was found for the present day (THI) and also for one-day and two-days before (THI1 and THI2). Significant interactions between THI and days in milk, farm and year were found. The lag heat effects explained more variability on milk yield than the heat effect for the present day. Threshold THI-values were different depending on the considered day: 75, 75 and 72 were estimated for THI, THI1 and THI2, respectively. Heat stress caused a decrease in milk yield of 1.3%, 1.9%, and 0.9% of average daily production (per THI unit increase above threshold), depending on the THI measure used.Con las perspectivas de calentamiento global, el estrés por calor, el efecto depresivo (verano) sobre la producción de leche, se ha convertido en un problema de investigación de alta prioridad en zonas templadas. El efecto del calor actual del verano y los efectos del retraso en el rendimiento de la leche de las vacas Holstein que pasaron la primera lactación se evaluó a través del índice de temperatura y humedad (THI). Además, se calcularon los umbrales de THI. Se utilizaron datos diarios de temperatura y humedad del aire de tres ubicaciones durante seis temporadas de verano (diciembre-marzo en los años 2001 - 2006). Se analizaron datos de 35500 días de prueba mensuales de 8875 vacas en 54 granjas dentro de las zonas de influencia de las estaciones meteorológicas respectivas. Se ajustaron modelos lineales mixtos, considerando al animal como efecto aleatorio y ubicación, granja, días de ordeño, edad al parto, año de parto y THI como efectos fijos. Se tomaron en cuenta cuatro medidas por animal y se modelaron como medidas repetidas. Se encontró un efecto de calor deprimente significativo en el rendimiento de la leche para el día presente (THI) y también para un día y dos días antes (THI1 y THI2). Se encontraron interacciones significativas entre THI y días en leche, granja y año. Los efectos del calor rezagado explicaron más variabilidad en el rendimiento de la leche que el efecto del calor para el día de hoy. Los valores de umbral de THI fueron diferentes según el día considerado: 75, 75 y 72 se estimaron para THI, THI1 y THI2, respectivamente. El estrés por calor provocó una disminución en la producción de leche de 1.3%, 1.9% y 0.9% de la producción diaria promedio (por unidad de THI aumenta por encima del umbral), dependiendo de la medida de THI utilizada

Chronic Chagas disease: from basics to laboratory medicine

Chagas disease, caused by Trypanosoma cruzi infection, is ranked as the most serious parasitic disease in Latin America and has huge potential to become a worldwide problem, due to increasing migration, and international tourism, as well as infectant transfer by blood contact and transfusion, intrauterine transfer, and organ transplantation. Nearly 30% of chronically-infected patients become symptomatic, often with a latency of 10-30 years, developing life-threatening complications. Of those, nearly 90% develop Chagas heart disease, while the others manifest gastrointestinal disease and neuronal disorders. Besides interrupting the infection cycle and chemotherapeutic infectant elimination, starting therapy early in symptomatic patients is important for counteracting the disease. This would be essentially supported by optimized patient management, involving risk assessment, early diagnosis and monitoring of the disease and its treatment. From economic and logistic viewpoints, the tools of laboratory medicine should be especially able to guarantee this. After summarizing the basics of chronic Chagas disease, such as the epidemiological data, the pathogenetic mechanisms thought to drive symptomatic Chagas disease and also treatment options, we present tools of laboratory medicine that address patient diagnosis, risk assessment for becoming symptomatic and guidance, focusing on autoantibody estimation for risk assessment and heart marker measurement for patient guidance. In addition, increases in levels of inflammation and oxidative stress markers in chronic Chagas disease are discussed

Alternative characterization of the nematic transition in deposition of rods on two-dimensional lattices

We revisit the problem of excluded volume deposition of rigid rods of length k unit cells over square lattices. Two new features are introduced: (a) two new short-distance complementary order parameters, called Π and ς, are defined, calculated, and discussed to deal with the phases present as coverage increases; (b) the interpretation is now done beginning at the high-coverage ordered phase which allows us to interpret the low-coverage nematic phase as an ergodicity breakdown present only when k≥7. In addition the data analysis invokes both mutability (dynamical information theory method) and Shannon entropy (static distribution analysis) to further characterize the phases of the system. Moreover, mutability and Shannon entropy are compared, and we report the advantages and disadvantages they present for their use in this problem.Fil: Vogel, E. E.. Universidad de La Frontera; ChileFil: Saravia, G.. Universidad de la Frontera. Facultad de Ingeniería y Ciencias; ChileFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Pasinetti, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Resistance to Oxidative Stress Is Associated with Metastasis in Mucocutaneous Leishmaniasis

Mucocutaneous leishmaniasis (MCL) in South and Central America is characterized by the dissemination (metastasis) of Leishmania Viannia subgenus parasites from a cutaneous lesion to nasopharyngeal tissues. Little is known about the pathogenesis of MCL, especially with regard to the virulence of the parasites and the process of metastatic dissemination. We previously examined the functional relationship between cytoplasmic peroxiredoxin and metastatic phenotype using highly, infrequently, and nonmetastatic clones isolated from an L. (V.) guyanensis strain previously shown to be highly metastatic in golden hamsters. Distinct forms of cytoplasmic peroxiredoxin were identified and found to be associated with the metastatic phenotype. We report here that peroxidase activity in the presence of hydrogen peroxide and infectivity differs between metastatic and nonmetastatic L. (V.) guyanensis clones. After hydrogen peroxide treatment or heat shock, peroxiredoxin was detected preferentially as dimers in metastatic L. (V.) guyanensis clones and in L. (V.) panamensis strains from patients with MCL, compared with nonmetastatic parasites. These data provide evidence that resistance to the first microbicidal response of the host cell by Leishmania promastigotes is linked to peroxiredoxin conformation and may be relevant to intracellular survival and persistence, which are prerequisites for the development of metastatic diseas

Early-life exposure to combustion-derived particulate matter causes pulmonary immunosuppression

Elevated levels of combustion-derived particulate matter (CDPM) are a risk factor for the development of lung diseases such as asthma. Studies have shown that CDPM exacerbates asthma, inducing acute lung dysfunction and inflammation; however, the impact of CDPM exposure on early immunological responses to allergens remains unclear. To determine the effects of early-lifeCDPMexposure on allergic asthma development in infants, we exposed infant mice to CDPM and then induced a mouse model of asthma using house dust mite (HDM) allergen. Mice exposed to CDPMHDM failed to develop a typical asthma phenotype including airway hyper-responsiveness, T-helper type 2 (Th2) inflammation, Muc5ac expression, eosinophilia, and HDM-specific immunoglobulin (Ig) compared with HDM-exposed mice. Although HDM-specific IgE was attenuated, total IgE was twofold higher in CDPMHDM mice compared with HDM mice. We further demonstrate that CDPM exposure during early life induced an immunosuppressive environment in the lung, concurrent with increases in tolerogenic dendritic cells and regulatory T cells, resulting in the suppression of Th2 responses. Despite having early immunosuppression, these mice develop severe allergic inflammation when challenged with allergen as adults. These findings demonstrate a mechanism whereby CDPM exposure modulates adaptive immunity, inducing specific antigen tolerance while amplifying total IgE, and leading to a predisposition to develop asthma upon rechallenge later in life. © 2014 Society for Mucosal Immunology

Rodenticide residues in non-target small mammal species and their occurrence in owl pellets

OBJECTIVES: Distinguishing the patterns of autoantibodies (AAB) against G-protein-coupled receptors in Chagas' cardiomyopathy and megacolon and the discovery of such a pattern in patients who are as yet asymptomatic could help to identify patients at high risk of developing the life-threatening complications of Chagas' disease. BACKGROUND: Such AAB against receptors as beta 1 (beta1-AAB), beta 2 (beta2-AAB), and muscarinergic 2 (M2-AAB) are thought to be involved in the pathogenesis of Chagas' cardiomyopathy and megacolon, the predominant manifestations of Chagas' disease, which is the most serious parasitic disease in Latin America. METHODS: Beta1-AAB, beta2-AAB, and M2-AAB were measured in the serum of asymptomatic Chagas' patients and in those with cardiomyopathy and/or megacolon. RESULTS: Nearly all Chagas' patients with cardiomyopathy and/or megacolon had AAB. Predominance of beta1-AAB combined with M2-AAB in Chagas' cardiomyopathy and beta2-AAB with M2-AAB in megacolon was found. Such patterns were also found in 34% of the asymptomatic patients, of whom 85% possessed a beta1-AAB level typical for Chagas' cardiomyopathy. CONCLUSIONS: The percentage of asymptomatic Chagas' patients who had a specific AAB pattern and had a beta1-AAB level above a defined cutoff point mirrors very well the epidemiological situation, which showed that clinical manifestations develop in nearly 30% of Chagas' patients and cardiomyopathy in nearly 90% of them. We hypothesize that beta1-, beta2-, and M2-AAB measurement might be a useful tool for risk assessment in the indeterminate state of Chagas' disease to select patients for earlier involvement in care programs. However, prospective studies are needed to further evaluate this hypothesis

Relevamiento de la cupremia en rodeos de cría bovina del chaco semiárido salteño (Argentina)

Saravia, F.C.; Martínez, M.V.; Ávila, G.N.: Relevamiento de la cupremia en rodeos de cría bovina del chaco semiárido salteño (Argentina). Rev. vet. 26: 1, 59-62, 201

Progress on the Development of an Iodine-fed Hall Effect Thruster

The paper deals with the results of an ongoing activity carried out by the Department of Civil and Industrial Engineering (DICI) and the Department of Chemistry and Industrial Chemistry (DCCI) of the University of Pisa (UniPi) in collaboration with SITAEL SpA, aimed at the development of technologies for Iodine-fed Hall Effect Thrusters. A feeding system architecture is described and the results of reduced order numerical models of the feeding system are illustrated, in both steady and unsteady state conditions. An activity for iodine interaction with materials is in progress. The experimental setups for material characterization tests are described. Material samples can be heated from room temperature up to 300 °C and exposed to iodine at high (soakage test) or low (flow test) concentration, simulating the condition at which the materials will undergo in the propulsion system, in the vacuum facility or in the spacecraft. Calibration and preliminary soakage test results are illustrated. On the thruster unit side, the candidate thruster and cathode are presented along with the modifications needed to operate them on iodine. Finally, a description of the foreseen test campaign and associated facilities is presented

Glycated hemoglobin, fasting insulin and the metabolic syndrome in males. Cross-sectional analyses of the aragon workers health study baseline

Background and aims: Glycated hemoglobin (HbA1c) is currently used to diagnose diabetes mellitus, while insulin has been relegated to research. Both, however, may help understanding the metabolic syndrome and profiling patients. We examined the association of HbA1c and fasting insulin with clustering of metabolic syndrome criteria and insulin resistance as two essential characteristics of the metabolic syndrome. Methods: We used baseline data from 3200 non-diabetic male participants in the Aragon Workers' Health Study. We conducted analysis to estimate age-adjusted odds ratios (ORs) across tertiles of HbA1c and insulin. Fasting glucose and Homeostatic model assessment - Insulin Resistance were used as reference. Here we report the uppermost-to-lowest tertile ORs (95%CI). Results: Mean age (SD) was 48.5 (8.8) years and 23% of participants had metabolic syndrome. The ORs for metabolic syndrome criteria tended to be higher across HbA1c than across glucose, except for high blood pressure. Insulin was associated with the criteria more strongly than HbA1c and similarly to Homeostatic model assessment - Insulin Resistance (HOMA-IR). For metabolic syndrome, the OR of HbA1c was 2.68, of insulin, 11.36, of glucose, 7.03, and of HOMA-IR, 14.40. For the clustering of 2 or more non-glycemic criteria, the OR of HbA1c was 2.10, of insulin, 8.94, of glucose, 1.73, and of HOMA-IR, 7.83. All ORs were statistically significant. The areas under the receiver operating characteristics curves for metabolic syndrome were 0.670 (across HbA1c values) and 0.770 (across insulin values), and, for insulin resistance, 0.647 (HbA1c) and 0.995 (insulin). Among non-metabolic syndrome patients, a small insulin elevation identified risk factor clustering. Conclusions: HbA1c and specially insulin levels were associated with metabolic syndrome criteria, their clustering, and insulin resistance. Insulin could provide early information in subjects prone to develop metabolic syndrome