150 research outputs found

    GnRH use in different times on estrus synchronization and ovulation in Santa Inês ewes.

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    Proceedings of the 28th Annual Meeting of the Brazilian Embryo Technology Society (SBTE), August, 2014, Natal, RN, Brazil. Abstracts

    Novel method to quantify intracellular accumulation of polyphosphate in EBPR systems

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    A new method for intracellular storage polyphosphate (poly-P)identification and quantification in enhanced biological phosphorus removal (EBPR) systems is proposed based on image analysis. In EBPR systems, 4',6-diamidino-2-phenylindole (DAPI) is usually combined with fluororescent in situ hybridization (FISH) to evaluate the microbial community. The proposed technique is based on an image analysis procedure specifically developed for determining poly-P inclusions within biomass suspension using solely DAPI by epifluorescence microscopy. Due to contradictory literature DAPI concentrations used for poly-P detection, the present work assessed the optimal DAPI concentration for samples acquired at the end of the EBPR aerobic stage when the accumulation is performed. Digital images were then acquired and processed by means of image processing and analysis. Regarding image analysis results and considering the current operational conditions, a promising correlation could be found between average poly-P intensity values and the analytical determination, although presenting a correlation coefficient somewhat far from the ideal. The proposed methodology can be seen as a promising alternative procedure to quantify intracellular poly-P accumulation in a faster and less labor intensive way

    Biopolymer monitoring using quantitative image analysis techniques

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    Polyhydroxyalkanoates (PHAs) are intracellular biopolymers with many applications, particularly as substitutes of polypropylene and polyethylene, due to their thermoplastic properties and biocompatible nature. Furthermore, glycogen is a polysaccharide of glucose with high importance in the metabolism of microbial communities and polyphosphate is a microbial storage compound that should be recovered in order to offset the worldwide depletion of phosphorus sources. The determination of these biopolymers by chemical analysis is a laborious task, often involving digestion processes prior to gas and high-performance liquid chromatography, which are time consuming and difficult to apply in industry. Currently, it is important to develop new, rapid and simple techniques to monitor these polymers. Image analysis is a non-invasive and rapid technique that has the potential to be used to quantify these intracellular polymers quickly, in real-time. Mesquita et al. (2013) showed that it is possible to predict the concentration of glycogen and PHAs by quantitative image analysis, using aniline blue and nile blue staining, respectively. Polyphosphate can also be predicted by this technique through DAPI staining, which is currently under development. These biopolymers are produced by several different microorganisms, and combining their quantification with fluorescence in situ hybridization (FISH) techniques for microbial identification can enable the determination of organisms that store high quantities of each biopolymer. In this work, an advanced quantitative technique is developed to perform real time monitoring of these three biopolymers in a bioreactor performing biological phosphorus removal. Image analysis of the biopolymers was combined with FISH to determine the storage level of each compound within the different microbial populations. This technique will further enable the assessment of biopolymer levels within microbial communities, which can be applied in the biopolymer production industry

    Shielding AZ91D-1%Ca from corrosion through ultrasound melt treatment: a study for stent design

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    Magnesium-based materials show great potential for producing biodegradable stents, but their high corrosion rates are a roadblock. This study investigates whether ultrasound melt treatment can change the corrosion response of an extruded AZ91D-1.0%Ca (wt.%) in Earle's Balanced Salt Solution by tailoring the intermetallics' morphology in the as-extruded state. The results showed that the wires from ultrasound-treated ingots corroded faster than non-treated ones in immersion for up to 6 hours. This trend shifted for longer periods, and ultrasound-treated material showed lower corrosion rates and uniform corrosion, while the non-treated material displayed localized corrosion signs. Tensile testing of the wires demonstrated that immersion in EBSS lowered the tensile strength and elongation at fracture due to material degradation, regardless of the processing route. Nonetheless, this decline was sharper in the non-treated material. These findings suggest that ultrasound melt processing can be a promising method for improving the corrosion resistance of magnesium-based materials, paving the way for their use in manufacturing biodegradable stents.This work was supported by Portuguese FCT under the project UIDB/04436/2020, the doctoral grant PD/BD/140094/2018 and SFRH/BD/145285/2019

    GnRH potential to synchronize follicular emergence and ovulation prior to superovulatory day 0 protocol in sheep.

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    The role of GnRH to synchronize ovulation and follicular emergence previous to superovulatory protocol, started on the first day of the estrous cycle (Day 0), was assessed in Santa Inês ewes. For estrus synchronization, 60 mg medroxyprogesterone acetate sponges were used for 6 d plus 37.5 ?g d-cloprostenol and 300 IU eCG at fifth day. After sponge removal, ewes were assigned to three treatments: GControl ? saline at 12 h (n = 10); G24h ? GnRH at 24 h (n = 10); or G36h ? GnRH at 36 h (n = 9). In conclusion, considering the beneficial effects of G36h in synchronizing ovulation and to promote the absence of dominant follicles in the first days of estrous cycle. According to data obtained, the best time to start the superovulatory treatment, known as "Day 0", could be 80 h after sponge removal (56 h for the occurrence of ovulation plus 24 h to reset dominant follicles), in the induction of synchronized estrus, for Santa Inês ewes.Proceedings of the 29th Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Gramado, RS, Brazil, August 20th to 23rd, 2015, and 31st Meeting of the European Embryo Transfer Association (AETE); Ghent, Belgium, September 11th and 12th, 2015

    Daily vaginal temperature in Girolando cows from three different genetic composition under natural heat stress.

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    The present trial evaluated the effect of crossbred composition and Temperature and Humidity Index (THI) on vaginal temperature (VT) of Girolando dairy cows maintained under tropical pasture during warm seasons. The VT was monitored along 41 to 96 h in 615 Girolando cows with different Holstein (H) × Gir genetic composition (1/2 H = 284, 3/4 H = 248, and 7/8 H = 83) from six Brazilian farms in the summer of 2016 and 2017. VT of each cow at each hour of the day and the respective THI were averaged per hour across all monitoring days to generate an averaged value for VT and THI during 24 h. A linear mixed model with repeated measures using restricted maximum likelihood (REML) method for (co)variance components estimation procedure was employed. The final model adjusted the VT for the effects of cow, time, THI, farm, year, pregnancy status, body condition score (BCS), milk yield, genetic composition, and genetic composition*time interaction. Fixed effects were evaluated by ANOVA and tested with Tukey test in R software version 3.6.1 (R Core Team, 2019). Overall mean of VT, air temperature (AT), and THI were 39.06 ± 0.52 °C, 25.63 ± 0.40 °C, and 75.06 ± 3.96, respectively. VT had moderate positive correlation with THI (r² = 0.45, P 0.05). The daily average VT was affected by genetic composition (P < 0.001) with highest temperature for 3/4 H (39.08 ± 0.06 °C a) and 7/8 H (39.09 ± 0.06 °C a) and lowest temperature for 1/2 H (38.95 ± 0.06 °C b). The difference of VT among the three crossbred groups varied in function of the time of the day, from 12:00 to 20:00 h (P < 0.001), with 3/4 Holstein and 7/8 Holstein cows reaching similar VT, above to the upper limit 39.1 °C and higher than 1/2 Holstein cows during all this period. In conclusion, Girolando cows are sensitive to heat stress in tropical condition during warm seasons. Moreover, Girolando cows with genetic composition higher than 3/4 Holstein display reduced thermoregulatory efficiency. Therefore, Girolando cows in tropical dairy farms require strategies to mitigate heat stress according to their genetic composition

    High-Fat Diet Induces Apoptosis of Hypothalamic Neurons

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    Consumption of dietary fats is amongst the most important environmental factors leading to obesity. In rodents, the consumption of fat-rich diets blunts leptin and insulin anorexigenic signaling in the hypothalamus by a mechanism dependent on the in situ activation of inflammation. Since inflammatory signal transduction can lead to the activation of apoptotic signaling pathways, we evaluated the effect of high-fat feeding on the induction of apoptosis of hypothalamic cells. Here, we show that consumption of dietary fats induce apoptosis of neurons and a reduction of synaptic inputs in the arcuate nucleus and lateral hypothalamus. This effect is dependent upon diet composition, and not on caloric intake, since pair-feeding is not sufficient to reduce the expression of apoptotic markers. The presence of an intact TLR4 receptor, protects cells from further apoptotic signals. In diet-induced inflammation of the hypothalamus, TLR4 exerts a dual function, on one side activating pro-inflammatory pathways that play a central role in the development of resistance to leptin and insulin, and on the other side restraining further damage by controlling the apoptotic activity

    Diet crude protein reduction on follicular fluid and cumulus-oocyte complexes of mid-lactating Girolando cows.

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    This study evaluated the effect of crude protein (CP) reduction in four diets (156, 139, 132, and 127 g Kg-1 DM) maintaining constant metabolizable protein (188 g/day) on the follicular fluid and cumulus-oocyte complexes of mid-lactating Girolando cows. Twenty-two Girolando cows with average of 21.55 ±3.19 L daily milk yield, 105.30 ±22.62 days in lactation and 3.22 ±0.03 body condition score were selected. To reduce CP in diets and maintain constant metabolizable protein, urea and soybean meal were gradually replaced by lignosulfonate-treated soybean meal (SoyPass®, Cargill), resulting in an increase in rumenundegradable protein and a reduction in rumen degradable protein. A linear and quadratic reduction was observed in the plasma and follicular fluid urea nitrogen concentration following CP reduction, with the most intense reduction occurring in the 127 g Kg-1 DM group (p<0.001). As CP reduced, there was a tendency for a linear increase in the follicular growth rate (P=0.0696), on the number and proportion of viable oocytes (P<0.09), and also a linear increase for the number (P=0.0397) and proportion (P<0.09) of grade I viable oocytes. Plus, there was a linear effect for the number of cumulus oophorus cells. Cows fed with the lowest amount of CP had cumulus-oocyte complexes with higher numbers of cumulus oophorus cells (P=0.0238). Also, the reduction of diet crude protein was followed by a decrease in the probability of oocytes? DNA degradation. In conclusion, the reduction of CP in the diet of mid-lactating Girolando cows, reduces urea nitrogen concentration in both blood plasma and follicular fluid, and, as a consequence, increases the viability of oocytes and the number of cumulus oophorus cells while reducing oocytes? DNA degradation of follicular included cumulus-oocyte complex. The reduction on dietary CP may improve in vivo oocytes-embryo development impacting fertility of lactating dairy cows

    Potencial do GnRH em sincronizar a emergência folicular e ovulação em protocolo superovulatório "dia 0" em ovinos.

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    O objetivo do estudo foi avaliar o papel do GnRH para sincronizar a ovulação e emergência folicular previamente a protocolo superovulatório iniciado no primeiro dia do ciclo estral (Dia 0) em ovelhas da raça Santa Inês. Em conclusão, a aplicação de GnRH 36 horas após a retirada da esponja foi eficiente em sincronizar a ovulação e promover a ausência de folículos dominantes nos primeiros dias do ciclo estral. De acordo com os dados obtidos, o melhor horário para iniciar o tratamento superovulatório, conhecido como ?Dia 0?, seria 80 h após a retirada da esponja (56 h para ocorrência da ovulação mais 24 h para a ausência de folículos dominantes), na indução do estro sincronizado, em ovelhas da raça Santa Inês
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