3,883 research outputs found

    Comparative evaluation between the extenders TES-TRIS and ACP-112® and the association of Sálva Marajó oil (Lippia origanoides) in the quality of cryopreserved buffalo sperm.

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    For artificial insemination, it is essential to use frozen semen, however the freezing process causes deleterious changes to the structure and integrity of sperm membranes that compromise the function of sperm. To avoid this cellular damage, extenders and suitable substrates must be used to recover the highest possible number of viable cells post-thaw. To this end, in the first experiment, we evaluated three different extenders: TES-TRIS, which is widely used for buffaloes; and an extender composed of powdered coconut water-based (ACP-112®) with or without milk (ACP-112®-milk) for buffalo semen freezing. In the second experiment, we evaluated the effect of Lippia origanoides oil extract on protecting buffalo sperm against cryoinjury arising from freezing semen. Semen was collected from ten buffalo bulls (10 ejaculates/bull) and diluted in TES-TRIS (control), ACP-112® or ACP-112®-Milk in the first experiment. In the second experiment, the samples were diluted in the diluent with the best results for sperm quality obtained in experiment I, and 2.5 µg mL-1, 5 µg mL-1 or 10 µg mL-1 of the plant extract was added to treatments; and a control group containing only the diluent was also included. The fresh semen was analyzed for conventional features such as motility, concentration, morphology and viability. After thawing, the samples were evaluated again for motility, vigor and supra-vital staining, and then, were performed the of thermal-resistance test, hypoosmotic test and evaluated sperm membrane integrity with the fluorescent probes PI, FITC-PSA and JC-1 using flow cytometry. The data were submitted to ANOVA, and the results were compared by Tukey?s test at a significance of 5%. In the first experiment, the extender TES-TRIS showed better results for the various characteristics evaluated compared to ACP-112® and ACP-112®-Milk (P 0.05). Based on these data, we demonstrated the beneficial effects of TES-TRIS for post-thaw buffalo sperm quality; however, no protective effect was observed for buffalo sperm cryopreserved with the different tested concentrations of Lippia origanoides extract oil

    Effects of Postmortem Aging Time and Muscle Location on Objective Measures of Semitendinosus Steak Tenderness

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    Beef tenderness is the most important trait affecting consumer beef eating satisfaction. Cuts from muscles with superior tenderness (tenderloin, ribeye, striploin) are consequently most highly valued, but because of recent record-high beef prices, the need to identify more economical cuts that will meet consumer expectations for tenderness is greater than ever. The eye of round (Semitendinosus) has traditionally been marketed as a lower-value cut, primarily owing to its inherent toughness. Tenderness improves throughout postmortem aging and continues to improve in muscles aged for greater than 35 days. Retail steaks from the Semitendinosus receive, on average, 17 days of aging, with almost half (48.5%) receiving less than 14 days. This indicates a significant opportunity for tenderness improvement of Semitendinosus steaks through extended aging times. In many muscles, including the Longissimus, tenderness depends on anatomical location. Tenderness is often reduced in regions of the muscle closest to the ends or in close proximity to heavy connective tissue seams. Very little is known about the effects of aging and anatomical location on the tenderness of the Semitendinosus. Warner-Bratzler shear force testing is commonly used to measure beef tenderness objectively. Consumers rate beef with shear values of 9.5 lb as “tender,” so if tenderness of Semitendinosus steaks can be improved to meet this threshold, then the eye of round may offer a suitable alternative to higher-valued cuts for consumers and an opportunity for increased value for processors. Thus, the objectives of this study were to evaluate the effects of aging and anatomical location on the tenderness of Semitendinosus steaks

    Crystal Field Triplets: A New Route to Non-Fermi Liquid Physics

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    A model for crystal field triplet ground states on rare earth or actinide ions with dipolar and quadrupolar couplings to conduction electrons is studied for the first time with renormalization group methods. The quadrupolar coupling leads to a new nontrivial, non-Fermi liquid fixed point, which survives in an intermediate valence Anderson model. The calculated magnetic susceptibility displays one parameter scaling, going as TαT^{-\alpha} (α0.4\alpha \approx 0.4) at intermediate temperatures, reminiscent of the non-Fermi liquid alloy UCu_{5-x}Pd_x.Comment: 4 pages, 3 figures, REVTe

    Caracterização molecular de híbridos do banco ativo de germoplasma de citros da Embrapa

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    Embora a citricultura brasileira seja uma das principais atividades agroindustriais do país, a base genética ainda é bastante estreita, tendo esse fato contribuído para a vulnerabilidade da cultura frente aos problemas fitossanitár

    Methods for determining the emission of greenhouse gases in swine farming.

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    ABSTRACT: Swine production systems contribute to emission of greenhouse gases (CO2, N2O, and CH4) and ammonia (NH3) into the atmosphere. Therefore, the objective of this study was to evaluate methods for determining the emissions of ammonia and greenhouse gases (GHG) in a commercial swine production unit with natural ventilation during the finishing phase. The concentrations of gases in the air were measured using a gas analyzer (INNOVA 1412), and the flow emission was calculated by considering the ventilation rate and the differences in gas concentration between the interior and exterior of the installation. The results showed that the emission flow obtained via the simplified method in [g per swine h-1] was 2.689, 0.30, 4.39, 13.55, and 3.273 for CO2, N2O, CH4, NH3 , and water vapor, respectively. The flow obtained using the continuous method in [g per swine h-1] was 574, 0.67, 19.50, 5.84, and 7.2 for CO2 , N2 O, CH4 , NH3 , and water vapor, respectively. The proposed simplified method was highly accurate for estimating GHG emissions from swine production systems with natural ventilation. Resumo: Os sistemas de produção de suínos contribuem com emissões de gases de efeito estufa (dióxido de carbono - CO2 , óxido nitroso - N2 O e metano - CH4 ) e amônia - NH3 para a atmosfera. Portanto, o objetivo deste estudo foi avaliar metodologias para determinação das emissões de amônia e gases de efeito estufa em uma unidade de produção comercial de suínos durante a fase de terminação, que possui ventilação natural. Foram medidas as concentrações de gases no ar pelo analisador de gases (INNOVA 1412) e foi calculada a vazão de emissões considerando a taxa de ventilação e as diferenças de concentração de gases entre o interior e o exterior da instalação. Os resultados mostraram que a vazão de emissão obtida pela metodologia simplificada em [g suíno por hora] foi: 2,689 para CO2, 0,30 para N2 O, 4,39 para CH4 , 13,55 para NH3 e 3,273 para vapor d’água. A vazão obtida para a metodologia contínua em [g suíno por hora] foi de 574 para CO2 , 0,67 para N2 O, 19,50 para CH4 , 5,84 para NH3 e 7,2 para vapor d’água. A metodologia simplificada foi altamente precisa para estimar as emissões de GEE em sistemas de produção de suínos com ventilação natural

    Evaluating autoencoders as a dimensionality reduction mechanism to support clustering Brazilian Agricultural Diversity.

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    Brazilian agricultural production presents high spatial diversity, challenging the conception of public policies. This article proposes an approach for grouping Brazilian municipalities according to their agricultural production. We combine a feature extraction using autoencoders and clustering based on k-means and Self-Organizing Maps. We used panel data from IBGE’s annual estimates of the production value of permanent and temporary crops, animal products, aquaculture, plant extractivism, forestry, planted areas, and herd population between 1999 and 2018. We analyzed different structures of simple stacked and incomplete autoencoders, varying the number of layers and neurons in each, and evaluated the asymmetric exponential linear loss function to handle the sparse data. We applied the Isomap, Kernel PCA, Truncated SVD, and MDS dimensionality reduction methods for comparative purposes. Results showed that the autoencoders could extract characteristics from the transformed raw data to allow the clustering of municipalities to reveal regional and even intra-regional patterns. The autoencoders improved comparative performance as the intrinsic dimensionality increased. A produção agrícola brasileira apresenta elevada diversidade espacial, o que desafia a concepção de políticas públicas. Este artigo propõe uma abordagem de agrupamento dos municípios brasileiros segundo sua produção agrícola. Combinamos extração de características utilizando autoencoders e clusterização baseada em k-médias e Mapas Auto Organizáveis. Utilizamos os dados em painel, entre 1999 e 2018, das estimativas anuais do IBGE sobre valor da produção de culturas permanentes, temporárias, produtos de origem animal, aquicultura, extrativismo vegetal, silvicultura, área plantada e efetivo de animais. Analisamos diferentes estruturas de autoencoders simples empilhados e incompletos, variando o número de camadas e neurônios em cada uma delas, e avaliamos a função de perda linear exponencial assimétrica para lidar com os dados esparsos. Comparamos os autoencoders com os métodos de redução de dimensionalidade Isomap, Kernel PCA, Truncated SVD e MDS. Os resultados mostraram que os autoencoders conseguiram extrair características dos dados brutos de forma a permitir a clusterização dos municípios revelasse padrões regionais e intra-regionais. Os autoencoders melhoram o desempenho comparativo à medida que a dimensionalidade intrínseca aument

    Identificação de progênies S1 de mandioca com maior nível de endogamia com base em marcadores microssatélites.

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    A mandioca (Manihot esculenta Crantz) é considerada uma espécie preferencialmente alógama e altamente heterozigótica, apresentando protoginia, mas podendo ocorrer autofecundação em taxas bem baixas

    Contribution of microscopy for understanding the mechanism of action against trypanosomatids

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    Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin
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