148 research outputs found

    Biomarkers of Thermal Adaptation: New Tools in Sustainable Livestock Production under Climate Change

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    Climate changes have been identified as one of the greatest environmental, social and economic threats to the planet and humanity. The increase of extreme weather events, such as prolonged droughts, extreme ambient temperatures or periods with high and intensive precipitation has effects on animal production systems. Crops, and consequently forage productivity and availability are compromised, the risk of new diseases increase, and animal production is impaired (growth, reproductive performance, metabolic and health status, and immune response can be affected). In this way the development of resilient and robust animal production systems, together with an improvement in the knowledge of the environmental impact in animal production and welfare are crucial to enhance innovation, sustainability and productivity in the animal sector. Ambient temperature and its abrupt extreme events have a major impact on the energy metabolism of livestock. This implies that animals presenting more physiological versatility can be best adapted, and therefore less susceptible to thermal stress and more productive. To achieve a production system where the detrimental effect of the climate change can be the minimum is necessary to improve the ability of the animal to cope with environmental stress by management and selection. The existence of biomarkers that allow to identify the levels of thermal stress and/or acclimation are valuable in the process of selecting the best well suited animals for each environmental condition, to propose selection programs based on that and for the herds management. Ideally biomarkers should be obtained from readily accessible samples, preferably non-invasively or minimally invasive, such as saliva, sweat and milk, hair and feces. Nowadays, the most commonly fluid used in biomarkers studies is the blood/plasma, but with growing tendency for being replaced. Blood cortisol has been one of the parameters more frequently used for assessing stressful conditions such as thermal stress. Nevertheless, it does not allow a full understanding of heat stress, due to its circadian cycle and because the confounding with other types of stress. Moreover, and taking the advantage of saliva as a non-invasive source of this corticosteroid, salivary cortisol has been also referred as potentially interesting. However, some of the limitations in taking conclusions from salivary cortisol results are the same reported for blood cortisol. Consequently, new and better non-invasive methods, than allow assessing stress, are necessary. The aim of this chapter is to present the state of the art on stress responses (climate, housing) and the principal effects of great temperature amplitudes in livestock production and the existing means to evaluate heat stress and acclimation capacity. Focus will be put on the importance of new reliable biomarkers. Saliva, hair, milk and feces will be discussed as potential sources of such non-invasive biomarkers

    Selectivity of Pesticides used in Integrated Apple Production to the Lacewing, Chrysoperla externa

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    This research aimed to assess the toxicity of the pesticides abamectin 18 CE (0.02 g a.i. L-1), carbaryl 480 SC (1.73 g a.i. L-1), sulfur 800 GrDA (4.8 g a.i. L-1), fenitrothion 500 CE (0.75 g a.i. L-1), methidathion 400 CE (0.4 g a.i. L-1), and trichlorfon 500 SC (1.5 g a.i. L-1) as applied in integrated apple production in Brazil on the survival, oviposition capacity, and egg viability of the lacewing, Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) from Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil. An attempt was made to study morphological changes caused by some of these chemicals, by means of ultrastructural analysis, using a scanning electronic microscope. Carbaryl, fenitrothion, and methidathion caused 100% adult mortality for both populations, avoiding evaluation of pesticides' effects on predator reproductive parameters. Abamectin and sulfur also affected the survival of these individuals with mortality rates of 10% and 6.7%, respectively, for adults from Bento Gonçalves, and were harmless to those from Vacaria at the end of evaluation. Trichlorfon was also harmless to adults from both populations. No compound reduced oviposition capacity. C. externa from Vacaria presented higher reproductive potential than those from Bento Gonçalves. In relation to egg viability, sulfur was the most damaging compound to both populations of C. externa. Ultrastructural analyses showed morphological changes in the micropyle and the chorion of eggs laid by C. externa treated with either abamectin or sulfur. The treatment may have influenced the fertilization of C. externa eggs and embryonic development. Sulfur was responsible for malformations in the end region of the abdomen and genitals of treated females. When applied to adults, abamectin, sulfur, and trichlorfon were harmless, while carbaryl, fenitrothion, and methidathion were harmful, according to the IOBC classification

    Pentoxifylline associated to hypertonic saline solution attenuates inflammatory process and apoptosis after intestinal ischemia/reperfusion in rats

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    PURPOSE:To evaluate intestinal inflammatory and apoptotic processes after intestinal ischemia/reperfusion injury, modulated by pentoxifylline and hypertonic saline.METHODS:It was allocated into four groups (n=6), 24 male Wistar rats (200 to 250g) and submitted to intestinal ischemia for 40 min and reperfusion for 80 min: IR (did not receive any treatment); HS group (Hypertonic Saline, 4ml/kg-IV); PTX group (Pentoxifylline, 30mg/kg-IV); HS+PTX group (Hypertonic Saline and Pentoxifylline). All animals were heparinized (100U/kg). At the end of reperfusion, ileal fragments were removed and stained on hematoxylin-eosin and histochemical studies for COX-2, Bcl-2 and cleaved caspase-3.RESULTS:The values of sO2 were higher on treated groups at 40 minutes of reperfusion (p=0.0081) and 80 minutes of reperfusion (p=0.0072). Serum lactate values were lower on treated groups after 40 minutes of reperfusion (p=0.0003) and 80 minutes of reperfusion (p=0.0098). Morphologic tissue injuries showed higher grades on IR group versus other groups: HS (p=0.0006), PTX (p=0.0433) and HS+PTX (p=0.0040). The histochemical study showed lesser expression of COX-2 (p=0.0015) and Bcl-2 (p=0.0012) on HS+PTX group. A lower expression of cleaved caspase-3 was demonstrated in PTX (p=0.0090; PTXvsIR).CONCLUSION:The combined use of pentoxifylline and hypertonic saline offers best results on inflammatory and apoptotic inhibitory aspects after intestinal ischemia/reperfusion.São Paulo University Medical SchoolUSP Medical SchoolFederal University of São Paulo Medical SchoolUSP School of MedicineUSP School of Medicine Department of SurgeryUSP Medical School Department of SurgeryUNIFESP, Medical SchoolSciEL

    Kebab: Kinetochore and EB1 Associated Basic Protein That Dynamically Changes Its Localisation during Drosophila Mitosis

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    Microtubule plus ends are dynamic ends that interact with other cellular structures. Microtubule plus end tracking proteins are considered to play important roles in the regulation of microtubule plus ends. Recent studies revealed that EB1 is the central regulator for microtubule plus end tracking proteins by recruiting them to microtubule plus ends through direct interaction. Here we report the identification of a novel Drosophila protein, which we call Kebab (kinetochore and EB1 associated basic protein), through in vitro expression screening for EB1-interacting proteins. Kebab fused to GFP shows a novel pattern of dynamic localisation in mitosis. It localises to kinetochores weakly in metaphase and accumulates progressively during anaphase. In telophase, it associates with microtubules in central-spindle and centrosomal regions. The localisation to kinetochores depends on microtubules. The protein has a domain most similar to the atypical CH domain of Ndc80, and a coiled-coil domain. The interaction with EB1 is mediated by two SxIP motifs but is not required for the localisation. Depletion of Kebab in cultured cells by RNA interference did not show obvious defects in mitotic progression or microtubule organisation. Generation of mutants lacking the kebab gene indicated that Kebab is dispensable for viability and fertility
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