Effect of roscovitine and cycloheximide on ultrastructure of sheep oocytes

It is believed the temporary meiosis arrest with roscovitine or cycloheximide may improve the in vitro developmental competence of oocytes in different animal species. However, little is known about the effects of these inhibitors on ultrastructure of ovines cumulus-oocyte complexes (COCs). The aim of this study was to evaluate the progression of cytoplasmic maturation and the ultrastructural changes in sheep COCs exposed to roscovitine or cycloheximide, at acceptable concentrations. COCs were in vitro cultured for 24. h in maturation medium (control group) containing 100 μM roscovitine or 1 μg/mL cycloheximide (treatment groups). After this time, some COCs were cultured for further 22. h in inhibitor-free medium. The ultrastructure organization of COCs was evaluated by transmission electron microscopy before (immature group) and after in vitro culture for 24 and 46. h. As expected, signs of immaturity and maturity were observed in immature and control groups, respectively. In treatment with roscovitine, there were cumulus cells degeneration, swelling of mitochondrias, few cortical granules and many vesicles with electron-dense material. However, in cycloheximide treatment there were not signs of degeneration or cellular senescence. Metabolic units and mitochondrial pleomorphism were found in all experimental groups. These evidences demonstrate that roscovitine promoted irreversible ultrastructural changes while cycloheximide did not affect the cytoplasmic maturation. However, the implications on embryo development are still unclear. © 2012 Elsevier B.V.

Capital flows and their effect on the monetary base

Includes bibliography

Old and new trade policies

Includes bibliography

Social investment funds in Latin America

Includes bibliography

Labour costs and competitiveness in the Latin American manufacturing sector, 1990-1998

Includes bibliography

Strengthening regional financial cooperation

Includes bibliography

Improving the grid operation and reliability cost of distribution systems with dispersed generation

In this work, a mathematical model to analyze the impact of the installation and operation of dispersed generation units in power distribution systems is proposed. The main focus is to determine the trade-off between the reliability and operational costs of distribution networks when the operation of isolated areas is allowed. In order to increase the system operator revenue, an optimal power flow makes use of the different energy prices offered by the dispersed generation connected to the grid. Simultaneously, the type and location of the protective devices initially installed on the protection system are reconfigured in order to minimize the interruption and expenditure of adjusting the protection system to conditions imposed by the operation of dispersed units. The interruption cost regards the unsupplied energy to customers in secure systems but affected by the normal tripping of protective devices. Therefore, the tripping of fuses, reclosers, and overcurrent relays aims to protect the system against both temporary and permanent fault types. Additionally, in order to reduce the average duration of the system interruption experienced by customers, the isolated operation of dispersed generation is allowed by installing directional overcurrent relays with synchronized reclose capabilities. A 135-bus real distribution system is used in order to show the advantages of using the mathematical model proposed. © 1969-2012 IEEE.

Infrastructure and economic growth in Peru

Includes bibliography

Effects of Jugular Vein Occlusion on Cardiovascular Parameters in Horses During Exercise on a Treadmill

The purpose of the present investigation was to examine the effects of unilateral and bilateral jugular vein occlusion by temporary surgical ligature on the heart rate and arterial and venous blood pressure in sedentary horses during progressive treadmill exercise. Six horses performed three exercise tests (ET). ET1, considered the control, was performed in horses without jugular occlusions. ET2 and ET3 were performed with unilateral and bilateral occlusion by temporary surgical ligature of the jugular veins, respectively. Heart rate, arterial pressure, and pressure of the occluded jugular vein were evaluated. Clinically, the horses presented apathy, head edema, congested mucous membranes, increased capillary refill time, and dysphagia. These signs were observed with the unilateral jugular vein occlusion and became more evident with the bilateral occlusion. Comparing ETs, no differences were observed in heart rate. However, jugular occlusions promoted a decrease in the mean arterial pressure and a severe increase in jugular pressure. Head edema caused by the jugular vein occlusion in the horses could interfere with the autonomic cardiovascular regulation of arterial blood pressure during exercise, likely leading to an impairment of tissue perfusion. Jugular occlusion, even unilateral, also causes severe head venous congestion, leading to venous hypertension that was aggravated by exercise, which could risk development of cerebral edema and neurological damage. The present results obtained from sedentary horses are preliminary data that lead us to suggest that sport horses presenting jugular occlusive thrombophlebitis, even unilateral, may be prevented from performing athletic activities. © 2013 Elsevier Inc. All rights reserved.

Two new species of Diaptomidae (Crustacea: Copepoda: Calanoida) from the Neotropical Region (Paraná River)

Two new species of Diaptomidae were found in the Middle Paraná River. The new species are referred to as Diaptomus curvatus sp. nov. and Diaptomus frutosae sp. nov. Important character states in Diaptomus curvatus include: right fifth leg with a well-developed endopod and with the lateral spine of the second exopod segment curved and longer than the segment on which it is inserted, plus the presence of a large dorsal process on urosomite 4 of the male. For Diaptomus frutosae they include: a differentiated hook-like process on segment 20 with chitinous protuberances at base of male right antennule; the last segment of the right leg 5 of male is triangular, and the lateral spine inserted distal to mid-level of this segment. Both species are placed in Diaptomus sensu lato as a temporary placement. http://www.zoobank.org/urn:lsid:zoobank.org:pub:FECDD6C4-C0AC-4043-ADDD-F29539B451F0. © 2013 Copyright Taylor and Francis Group, LLC.

Hormonal treatment of dairy goats affected by hydrometra associated or not with ovarian follicular cyst

Hydrometra is considered a very important pathological condition, because it represents one of the main causes of temporary infertility in dairy goats. The objective was (i) to evaluate a protocol for the treatment of hydrometra associated (n=2) or not (n=17) with follicular ovarian cyst in 19 dairy goats and (ii) to assess its reproductive efficiency after treatment. For this purpose, 10. mg of dinoprost (PGF) divided in two equal doses were administered to all animals intravulvosubmucosally on Days 0 and 10. In addition, 500. IU hCG were administered on Day 7. Ultrasound exams were performed in all females from Days 0 to 3, 7 and 10 to 13 of treatment, in order to evaluate uterus drainage after each treatment. Goats were monitored for estrus after both treatments and mated after the second dose of PGF. Blood samples were collected from 11 goats to determine plasma progesterone concentrations before, during and after treatment. Of the 19 goats treated, 16 lost weight after the first dose, probably due to uterine discharge. Complete drainage of uterine fluid was observed in 11/19 (57.9%) and 17/19 (89.5%) after the first and second doses, respectively. Afterwards, we diagnosed 2 more goats with follicular cysts, for a total of 21.1% (4/19) of animals exhibiting hydrometra and ovarian cyst concomitantly. In one doe the diagnosis was on Day 2 and in the other on Day 11. All does showed progesterone concentrations superior to 1. ng/mL at Day 0, with an average of 10.6 ± 1.4. ng/mL. Out of the 10 goats mated, only two became pregnant after treatment, corresponding to 10.5% of the total (2/19). Although prostaglandin was effective to drain the uterine fluid and led to the onset of estrus, it did not improve the pregnancy rate. The use of hCG in female goats was not effective in luteinizing the cysts. It can be concluded that hydrometra alone or associated with ovarian follicular cyst may adversely affect goat reproductive performance. © 2012 Elsevier B.V.