2,331 research outputs found

    Avaliação da estratégia de tratamento parcial do rebanho no controle da mosca-dos-chifres.

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    A mosca-dos-chifres (MDC) destaca-se dentre os principais ectoparasitos que acometem a pecuária de corte nacional. Seu controle é realizado quase exclusivamente com produtos inseticidas, o que tem levado a sérios problemas de resíduos e resistência. Alternativas não químicas e redução do uso de inseticidas tornam-se essenciais ao controle sustentável deste parasito. O presente estudo avaliou a eficiência do tratamento parcial do rebanho como estratégia de controle da MDC. Quatro experimentos foram conduzidos, utilizando produtos de diferentes classes inseticidas: lactona macrocíclica (ivermectina), fenilpirazol (fipronil), piretróide cipermetrina) e organofosforado+piretróide (clorpirifós+cipermetrina), em formulações pour-on. Em cada experimento, 200 vacas Nelore foram distribuídas em quatro grupos, para avaliação do tratamento de 20%, 50% e 100% do rebanho, além de um grupo não tratado. Contagens periódicas da MDC foram realizadas nos dias 0, 3, 7, 14, 21 e 28 em todos os animais. A eficácia dos produtos nos grupos tratados integralmente foi superior a 90% (exceto pela cipermetrina) ao final da 1ª semana pós-tratamento, sendo de modo geral superior a dos tratados parcialmente nas duas semanas iniciais. Nos grupos tratados parcialmente, a eficácia foi geralmente maior nos grupos com maior frequência de animais tratados. Independente da classe inseticida aplicada e do percentual de animais tratados (20% ou 50%), o tratamento parcial do rebanho apresentou três características principais: a) rápida e acentuada redução das infestações em todo o rebanho, b) menores níveis de redução das infestações e c) menor período de proteção, em relação ao tratamento de todo o rebanho. Apesar da redução no uso de inseticidas e do menor custo, a viabilidade do tratamento parcial do rebanho, como estratégia de controle da MDC, se limita a situações onde um menor nível e período de eficácia sejam aceitáveis, caso contrário, tratamentos adicionais podem ser necessários, comprometendo as vantagens da estratégia. As implicações do tratamento parcial do rebanho no desenvolvimento e manejo da resistência a inseticidas devem ser avaliadas. The horn fly stands out among the main ectoparasites that affect national beef cattle. This livestock pest is controlled almost exclusively by insecticide products, which has led to serious residue and resistance issues. Non-chemical alternatives and reduction of insecticide use are essential for a sustainable control of this parasite. This study evaluated the efficiency of partial herd treatment as a strategy for controlling horn flies. Four experiments were conducted using products from different insecticide classes: macrocyclic lactone (ivermectin) phenylpyrazole (fipronil), pyrethroid (cypermethrin), and an organophosphate-pyrethroid mixture (chlorpyrifos + cypermethrin), in pour-on formulations. In each experiment, 200 Nelore cows were distributed in four groups for evaluation of the treatment of 20, 50, and 100% of the herd, besides an untreated group. Periodic fly counts were performed on days 0, 3, 7, 14, 21, and 28 in all animals. Product efficacy in the full-treated herd exceeded 90% (except for cypermethrin) at the end of the 1st week after treatment, being mostly higher than in partially treated groups in the first two weeks. In the groups partially treated, efficacy was generally higher in the groups with the largest frequency of treated animals. Regardless of the insecticide class and the percentage of treated animals (20% or 50%), the partial treatment of the herd showed three main features: a) fast and marked reduction in infestations throughout the herd, b) lower reduction of horn fly infestations, and c) shorter period of protection, when compared to the full herd treatment. Despite reduction in insecticide use and lower costs, viability of partial herd treatment as a strategy for controlling the horn fly is limited to situations where a lower level and protection period are acceptable; otherwise, the need for additional treatments tends to compromise the advantages of the strategy. The implications of partial herd treatment in the development and management of insecticide resistance should be evaluated.bitstream/item/129471/1/BP125.pd

    Hyperextended Scalar-Tensor Gravity

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    We study a general Scalar-Tensor Theory with an arbitrary coupling funtion ω(ϕ)\omega (\phi ) but also an arbitrary dependence of the ``gravitational constant'' G(ϕ)G(\phi ) in the cases in which either one of them, or both, do not admit an analytical inverse, as in the hyperextended inflationary scenario. We present the full set of field equations and study their cosmological behavior. We show that different scalar-tensor theories can be grouped in classes with the same solution for the scalar field.Comment: latex file, To appear in Physical Review

    Aumento das infestações pela mosca-dos-chifres em bovinos nelore no Pantanal Sul-Mato-Grossense.

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    Após sua introdução no norte do país na década de 70, a mosca-dos-chifres (Haematobia irritans) chegou à região Centro-Oeste no início dos anos 90. No Pantanal, sua presença foi registrada pela primeira vez em 1991 (Barros, 1992), demandando conhecimento sobre sua ecologia e controle.bitstream/CPAP-2009-09/56780/1/CT80.pdfFormato eletrônico

    Procedimentos para aplicação de injeções em equinos: cuidados para evitar acidentes

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    A aplicação de medicamentos injetáveis em equinos pode ser feita por um técnico habilitado ou até mesmo pelo proprietário do animal, desde que sejam respeitadas as recomendações do médico veterinário, no que se refere à droga utilizada, dose e via medicamentosa prescrita por esse profissional.bitstream/CPAP/56030/1/CT69.pdfFormato eletrônic

    Obstetric and perinatal risks after the use of donor sperm : A systematic review and meta-analysis

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    Donor sperm is widely used in infertility treatments. The purpose of the study was to investigate, whether use of donor sperm in intrauterine insemination (IUI) or in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments affect maternal and perinatal risks compared with spontaneously conceived pregnancies or use of partner sperm in IUI, IVF or ICSI. We provide a systematic review and meta-analyses on the most clinically relevant obstetric and perinatal outcomes after use of donor sperm compared with partner sperm: hypertensive disorders of pregnancy, preeclampsia, low birth weight, and preterm birth. Our meta-analyses showed an increased risk for preeclampsia (pooled adjusted odds ratio (aOR) 1.77, 95% CI 1.26-2.48) and hypertensive disorders of pregnancy (pooled aOR 1.55, 95%, CI 1.20-2.00) in pregnancies resulting from IUI with donor sperm compared with IUI with partner sperm. No increased risk was seen for low birth weight or preterm birth after the use of donor sperm in IUI compared with the use of partner sperm in IUI. Subgroup analysis for singletons only did not change these results. The meta-analysis on low birth weight showed a lower risk after in IVF with donor sperm compared with IVF with partner sperm (pooled aOR 0.89, 95% CI 0.83-0.94). For hypertensive disorders of pregnancy, preeclampsia and preterm birth, no difference was found between IVF with donor sperm vs. partner sperm. Patients need to be informed about the moderately increased risk of hypertensive disorders of pregnancy and preeclampsia in pregnancies after IUI with donor sperm.Peer reviewe

    Isotropization of Bianchi type models and a new FRW solution in Brans-Dicke theory

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    Using scaled variables we are able to integrate an equation valid for isotropic and anisotropic Bianchi type I, V, IX models in Brans-Dicke (BD) theory. We analyze known and new solutions for these models in relation with the possibility that anisotropic models asymptotically isotropize, and/or possess inflationary properties. In particular, a new solution of curve (k0k\neq0) Friedmann-Robertson-Walker (FRW) cosmologies in Brans-Dicke theory is analyzed.Comment: 15 pages, 4 postscript figures, to appear in Gen. Rel. Grav., special issue dedicated in honour of Prof. H. Dehne

    A case series on the value of tau and neurofilament protein levels to predict and detect delirium in cardiac surgery patients

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    BACKGROUND: Delirium following cardiac surgery is a relevant complication in the majority of elderly patients but its prediction is challenging. Cardiopulmonary bypass, essential for many interventions in cardiac surgery, is responsible for a severe inflammatory response leading to neuroinflammation and subsequent delirium. Neurofilament light protein (NfL) and tau protein (tau) are specific biomarkers to detect neuroaxonal injury as well as glial fibrillary acidic protein (GFAP), a marker of astrocytic activation. METHODS: We thought to examine the perioperative course of these markers in a case series of each three cardiac surgery patients under off-pump cardiac arterial bypass without evolving delirium (OPCAB-NDEL), patients with a procedure under cardio-pulmonary bypass (CPB) without delirium (CPB-NDEL) and delirium after a CPB procedure (CPB-DEL). Delirium was diagnosed by the Confusion Assessment Method for the ICU and chart reviews. RESULTS: We observed increased preoperative levels of tau in patients with later delirium, whereas values of NfL and GFAP did not differ. In the postoperative course, all biomarkers increased multi-fold. NfL levels sharply increased in patients with CPB reaching the highest levels in the CPB-DEL group. CONCLUSION: Tau and NfL might be of benefit to identify patients in cardiac surgery at risk for delirium and to detect patients with the postoperative emergence of delirium
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