Comparação do efeito do ácido etilenodiaminotetracético (EDTA) e da heparina sobre os eritrócitos de avestruzes (Struthio camelus L.)

Anticoagulantes com diferentes formas de ação têm sido utilizados na hematologia aviária. Entretanto, poucos estudos foram publicados sobre seu efeito e sobre os parâmetros hematológicos dos avestruzes. Visando a preencher essa lacuna, realizou-se um estudo em que foi comparado o efeito de dois anticoagulantes de rotina (EDTA - 2 mg/mL sangue e da Heparina -10U/mL sangue) sobre os eritrócitos de avestruzes. Para tanto, foram avaliados a integridade, o volume globular e a morfometria dos eritrócitos de amostras sanguíneas de 20 aves, tratadas com ambos os anticoagulantes. A integridade eritrocitária foi estimada pelo grau de hemoglobina livre no plasma, sendo o volume globular obtido pelo método de micro-hematócrito e os dados morfométricos (área, diâmetro maior e menor) calculados automaticamente em sistema computadorizado de imagem digital de alta resolução. A hemólise estimada pela dosagem de hemoglobina plasmática, o volume globular, a área e o diâmetro máximo dos eritrócitos foram significativamente maiores nas amostras tratadas com EDTA. Para melhor preservar a integridade e a morfometria dos eritrócitos, concluiuse que a heparina é um anticoagulante mais adequado que o EDTA para avaliar as discrasias eritrocitárias dos avestruzes.

Jejum Pré-abate em Frangos de Corte

As condições ideais dos frangos de corte no momento do abate devem ser conhecidas a fim de possibilitar a produção de carne de excelente qualidade, uma vez que diversos fatores pré e pós-abate estão envolvidos na qualidade final. em condições normais de abate e processamento, a retirada de ração é feita de 6 a 8 horas antes da apanha das aves, resultando em um período total de jejum de 8 a 12 horas antes do abate, para esvaziar o intestino e com isso minimizar a contaminação no abatedouro. A escalda, depena e evisceração são pontos importantes de contaminação cruzada no abatedouro devido à grande quantidade de microorganismos aderidos às penas, pele e patas das aves e ao rompimento das vísceras durante a evisceração. Entretanto, a desidratação da carcaça começa imediatamente após o início do jejum. Períodos prolongados de jejum podem afetar o pH das diversas partes do intestino, aumentando a presença de Salmonella e outros microorganismos patogênicos. Além disso, determinam uma maior contaminação pela bile, e são, subjetivamente, associados à fragilidade dos intestinos durante a evisceração mecânica. Portanto, os esquemas de processamento devem ser estabelecidos levando-se em conta a integridade e o esvaziamento do intestino e da vesícula biliar, bem como a desidratação e os seus efeitos sobre o bem estar das aves, contaminação da carcaça e qualidade da carne. Como alguns efeitos do jejum ainda não são bem conhecidos, sugerem-se pesquisas nas seguintes áreas: definir o tempo ótimo de jejum para atender o bem estar das aves, minimizar a contaminação e otimizar os parâmetros de qualidade de carcaça; estudar os efeitos de períodos prolongados de jejum sobre o pH e a colonização do papo, pró-ventrículo, moela, intestino delgado, intestino grosso e cecos por enterobactérias, como Salmonella, por exemplo; efeito do jejum sobre o tamanho e cor do fígado. O resultado esperado é um aumento na qualidade final dos produtos aliado a uma redução nas perdas e no custo de produção.

Testing transposable elements as genetic drive mechanisms using Drosophila P element constructs as a model system

The use of transposable elements (TEs) as genetic drive mechanisms was explored using Drosophila melanogaster as a model system. Alternative strategies, employing autonomous and nonautonomous P element constructs were compared for their efficiency in driving the ry(+) allele into populations homozygous for a ry(-) allele at the genomic rosy locus. Transformed flies were introduced at 1%, 5%, and 10% starting frequencies to establish a series of populations that were monitored over the course of 40 generations, using both phenotypic and molecular assays. The transposon-borne ry(+) marker allele spread rapidly in almost all populations when introduced at 5% and 10% seed frequencies, but 1% introductions frequently failed to become established. A similar initial rapid increase in frequency of the ry(+) transposon occurred in several control populations lacking a source of transposase. Constructs carrying ry(+) markers also increased to moderate frequencies in the absence of selection on the marker. The results of Southern and in situ hybridization studies indicated a strong inverse relationship between the degree of conservation of construct integrity and transposition frequency. These finding have relevance to possible future applications of transposons as genetic drive mechanisms.

Bull semen varibles after experimental exposure with Bovine Herpesvirus type 5

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comparativo do desempenho de rebolos com grãos superabrasivos e convencionais

Grinding is a precision machining process which is widely used in the manufacture of components requiring fine tolerances and smooth surfaces. There are several imput parameters (cutting conditions, cutting fluid and grinding wheel type used, dressing conditions etc.) which can affect the process variables (tangential and normal cutting forces, roughness, grinding temperatures, G ratio, etc.) leading to differences in the roughness, in the surface integrity and in the mechanical strength of the ground component. Consequently, the imput parameters must be controlled in order to insure the workpiece final quality. This paper presents a comparative evaluation of the performance of two types of grinding wheels [a conventional (Al2O3) and a superabrasive (CBN)] when grinding a VC131 steel, by the analysis of specific process variables when varying the cutting conditions. Highest values of G ratio and lowest workpiece roughness was observed when using CBN grinding wheels. This confirms the global trend of replacement of alumina grinding wheels by CBN, when grinding DTG (difficult to grind) materials.

Defects location in power systems components through a dedicated genetic algorithm

In this work the problem of defects location in power systems is formulated through a binary linear programming (BLP) model based on alarms historical database of control and protection devices from the system control center, sets theory of minimal coverage (AI) and protection philosophy adopted by the electric utility. In this model, circuit breaker operations are compared to their expected states in a strictly mathematical manner. For solving this BLP problem, which presents a great number of decision variables, a dedicated Genetic Algorithm (GA), is proposed. Control parameters of the GA, such as crossing over and mutation rates, population size, iterations number and population diversification, are calibrated in order to obtain efficiency and robustness. Results for a test system found in literature, are presented and discussed. © 2004 IEEE.

Minimally processed guava Fruits (Psidium guaiava L.)

'Paluma' guavas, after internal quality evaluation using magnetic resonance tomography, were used to produce fresh-cut product. Fruits were peeled or not, cut in halves and seed removed, and they were packaged in polystyrene trays covered with PVC film or in a PET container with a lid. These packages were stored for 12 days at 5°C, 10°C and ambient temperature (22.6°C). Tomography evaluation verified that impacts produced internal bruising with loss of cellular integrity and liquefication of the placenta tissues. Compression was more evident on the pericarp and cutting promoted superficial deformation. Storage temperature affected the weight loss, with fruit packaged in the polystyrene tray having a greater weight loss. The peeling did not influence weight loss. Product stored at 5°C and 10°C for 8 days had low microbial growth (<103 UFC.g-1) and no coliforms. Rapid spoilage and a short shelf life (3-4 days) occurred when the product was stored at ambient temperature. Peeling reduced ascorbic acid concentration and total soluble solids. Use of calcium to protect fresh-cut products was not efficient. Calcium absorption capacity of 'Pedro Sato' guava was tested using 45Ca. Fruits treated with 2% CaCl2, with or without the radioisotope, were divided in four layers (epicarp, mesocarp, endocarp and seed) and analyzed for the total and 45Ca calcium. It was observed that the applied calcium remained in superficial layers of45fruits, which was confirmed by autoradiography. Internal layers did not contain 45Ca, indicating that calcium was not distributed into different parts of the fruit.

Chitosan nanoparticles for non-viral gene therapy

The cationic polysaccharide chitosan has been widely used for non-viral transfection in vitro and in vivo and has many advantages over other polycations. Chitosan is biocompatible and biodegradable and protects DNA against DNase degradation. However following administration the ChitosanDNA polyplexes must overcome a series of barriers before DNA is delivered to the cell nucleus. This paper describes the most important parameters involved in the chitosan-DNA interaction and their effects of on the condensation, shape, size and protection of DNA. Strategies developed for chitosanDNA polyplexes to avoid non-specific interaction with blood components and to overcome intracellular obstacles as the crossing of die cell membrane, endosomal escape and nuclear import are presented. © 2006 American Chemical Society.

Social Panorama of Latin America 2004

Includes bibliography

Envejecimiento, derechos humanos y políticas públicas

Incluye Bibliografía

Defeating poverty through social inclusion

Includes bibliography

The use of current transformers for noise detection due to sparking in insulators strings in high voltage transmission lines

In a general way, in an electric power utility the current transformers (CT) are used to measurement and protection of transmission lines (TL) 1 The Power Line Carriers systems (PLC) are used for communication between electrical substations and transmission line protection. However, with the increasing use of optical fiber to communication (due mainly to its high data transmission rate and low signal-noise relation) this application loses potentiality. Therefore, other functions must be defined to equipments that are still in using, one of them is detecting faults (short-circuits) and transmission lines insulator strings damages 2. The purpose of this paper is to verify the possibility of using the path to the ground offered by the CTs instead of capacitive couplings / capacitive potential transformers to detect damaged insulators, since the current transformers are always present in all transmission lines (TL's) bays. To this a comparison between this new proposal and the PLC previous proposed system 2 is shown, evaluating the economical and technical points of view. ©2010 IEEE.

Effects of ascorbic acid on in vitro culture of bovine preantral follicles

The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed (control) and the other fragments were cultured in minimum essential medium (MEM) supplemented or not with various doses of ascorbic acid. Ovarian tissue was processed for histology, transmission electron microscopy (TEM) and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Compared with control fragments, the percentage of primordial follicles was reduced (p < 0.05) and the percentage of growing follicles had increased (p < 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (p < 0.05), but not when cultures were supplemented with 25, 50 or 100 μg/ml of ascorbic acid. Ultrastructural and immunohistochemical analysis of 8 day cultured ovarian cortical fragments, however, showed the integrity and viability of follicles only when fragments were cultured in presence of 50 μg/ml of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg/ml not only stimulates the activation of 8 day in vitro cultured cattle primordial follicles and subsequent growth of activated follicles, but also safeguards the viability of these early-stage follicles. © 2012 Copyright Cambridge University Press.

Congelação de espermatozoides epididimários de gatos utilizando o diluidor Botu-crio® após refrigeração por 24 h em contêiner de transporte de sêmen Botu-tainer®

The possibilities of using the sperm collected from the epididymis have been widely used because the fertilizing capacity sperm preservation and the possibility of using it for wild cats. But in the process of cryopreservation, some studies show a decrease in the quality of the sperm when left under cooling before frozen for some time. This study aimed to assess the quality of the epididymal sperm obtained from domestic cats after cryopreservation using a diluent based on egg yolk and glycerol (Botu-crio®), comparing the morphofunctional characteristics after cooling for 24 hours in a container of semen transport (Botu-tainer®). We use eight cats submitted to elective orchiectomy, aging from eight months, without racial determination, and good nutritional status. These sperm characteristics were: motility, vigor, concentration, membrane integrity and morphology. It has been found, after statistical analysis, that the container of semen was able to maintain sperm viability, even for 24h. We also observed a significant decrease on all parameters after frozen, consequential, probably to thermal stress that occurs in processing. However, the percentage of membrane integrity after thawing shows good employability of the Botu-crio®, which viability is possible to perform in vitro fertilization, requiring higher ratings.

Effects of Pentoxifylline on Equine Epididymal Sperm

This study evaluated whether pentoxifylline (PTX) present in the flushing extender influenced the function of equine epididymal spermatozoa after recovery and after thawing. For this experiment, 58 testicles from 29 Brazilian Jumping Horses were used. Cauda epididymides of each stallion were separated and flushed with a skim milk extender, with or without 7.18 mM PTX and then subjected to the freezing process. Samples flushed with the extender containing PTX showed a significant increase in total motility, progressive motility, straight line velocity, curvilinear velocity, and percentage of rapid sperm immediately after the recovery of epididymal sperm and after 15 minutes of incubation at 37°C (P < .05). However, the presence of PTX in the flushing extender did not affect the post-thaw motility parameters or plasma membrane integrity (P > .05). The results of this study showed that the PTX present in the flushing extender improved motility parameters of recently recovered epididymal sperm and had no deleterious effects on plasma membrane integrity and freezability of equine epididymal sperm. © 2013 Elsevier Inc. All rights reserved.