949 resultados para Embryo reconstruction
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The objective of this study was to evaluate alternatives in small volumes to conventional gradient of Percoll((R)) on semen quality, in vitro embryo production, sex ratio and embryo survival after vitrification. Thawed semen was randomly allocated to one of four density gradient selection methods: (1) conventional Percoll((R)) (P), (2) MiniPercoll (MP), (3) MiniIsolate (MI), and (4) MiniOptiprep (MO). Sperm kinetics and quality were evaluated. Use of P, MP and MI gradients did not affect sperm motility (P > 0.05). However, there was a decrease in total and progressive sperm motility in MO (70.8 and 51.3% vs. 87.3 and 69.5% for P; 87.3 and 73% for MP; 92.3 and 78.8% for MI; P < 0.05). The MO had lower membrane integrity compared with P, MP and MI (39.7 vs. 70.5, 72.3, 63.8%, respectively, P < 0.05). The percentage of blastocysts produced was higher in MI than in MP and MO (21.1 vs. 16.1 and 16.9%, P < 0.05) and similar to P (18.4%; P > 0.05). Sex ratio and embryo survival after vitrification were similar among groups (P > 0.05). Semen selected by Isolate and Optiprep gradient, at the concentrations and small volumes used, demonstrated similar characteristics and in vitro embryo production to conventional Percoll((R)) gradient.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In the world stage, the environmental condition has been a big public policies issue. A clear understanding of the parameters that determine the state of the environment is essential for estimation of the quality of life of the population, not least since ecosystems are highly complex. Consequently, definition of public policies demands the use of evaluation tools that can combine and quantify information in a clear way. The use of indicators and indices that are able to translate the complexity of environmental conditions in cities into simpler terms has been increasingly effective in decision-making, since they assist in general evaluation of the situation in question, identification of priority actions and anticipation of future trends. In an attempt to evaluate the environmental conditions of the Brazilian city, Sorocaba, an Environmental Quality Fuzzy Index (IFQAmb) was proposed. In this work this methodology is improved. After reviewing the IFQAmb methodology, a number of changes in the index are proposed. Additional variables are suggested, derived from a State Environment Department program whose objective is to grant municipalities the title of Municipio Verde e Azul (Green and Blue City). In addition, a new rule base is being drafted to enable consideration of all possibilities, since in the existing version the use of specific criteria eliminates a significant number of rules. The changes seek to define with clarity and precision the conceptual aspects and structure of the IFQAmb, so that it can provide an even more effective evaluation of environmental performance, guiding future actions in order to improve the living conditions of the population of Sorocaba.
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The major challenge for a greater dissemination of in vitro produced (IVP) bovine embryos is to improve embryonic survival after cryopreservation. The involvement of embryonic lipids on this issue is well documented. However, it has been recognized that not only the amount of lipids that affects embryo cryotolerance, but the embryo survival capacity after cryopreservation is a rather multifactorial event. In this review, some strategies to improve embryonic lipid composition and postcryopreservation survival by modifying the embryos themselves to make them more cryopreservable are overviewed. The use of semi-defined and defined serum-free culture media, the addition of some chemicals in the culture media to modify embryo lipid composition, and the modulation of embryo cell membrane fluidity by cholesterol or unsaturated fatty acids added to the culture media and oocyte/embryo donor nutritional management with a diet enriched in polyunsaturated fatty acids, were described as alternatives for the improvement of IVP embryo survival after cryopreservation.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Currently, timed ovulation induction and timed artificial insemination (TAI) can be performed in buffalo using GnRH or estradiol plus progesterone/progestin (P4)-releasing devices and prostaglandin F-2 alpha (PGF(2 alpha)). The control of the emergence of follicular waves and of ovulation at predetermined times, without the need for estrus detection, has facilitated the management and improved the efficiency of AI programs in buffalo during the breeding and nonbreeding season. Multiple ovulations, embryo transfer, ovum collection and in vitro embryo production have been shown to be feasible in buffalo, although low efficiency and limited commercial application of these techniques have been documented as well. These results could be associated with low ovarian follicular pools, high levels of follicular atresia and failures of the oocyte to enter the oviduct after superstimulation of follicular growth. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve pregnancy rates following TAI and embryo transfer of in vivo- and in vitro-derived embryos in buffalo.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The Virgo detector is a kilometer-scale interferometer for gravitational wave detection located near Pisa (Italy). About 13 months of data were accumulated during four science runs (VSR1, VSR2, VSR3 and VSR4) between May 2007 and September 2011, with increasing sensitivity. In this paper, the method used to reconstruct, in the range 10 Hz-10 kHz, the gravitational wave strain time series h(t) from the detector signals is described. The standard consistency checks of the reconstruction are discussed and used to estimate the systematic uncertainties of the h(t) signal as a function of frequency. Finally, an independent setup, the photon calibrator, is described and used to validate the reconstructed h(t) signal and the associated uncertainties. The systematic uncertainties of the h(t) time series are estimated to be 8% in amplitude. The uncertainty of the phase of h(t) is 50 mrad at 10 Hz with a frequency dependence following a delay of 8 mu s at high frequency. A bias lower than 4 mu s and depending on the sky direction of the GW is also present.