Does the inclusion of protease inhibitors in the insemination extender affect rabbit reproductive performance?

[EN] The bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases. Thus, the addition of amino peptidase inhibitors to rabbit semen extenders could be a solution to decrease the hormone degradation. This study was conducted to evaluate the effect of the protease activity inhibition on rabbit semen quality parameters and reproductive performance after artificial insemination. Seminal quality was not affected by the incubation with protease inhibitors, being the values of motility, viability, and acrosome integrity not significantly different between the protease inhibitors and the control group. In addition, seminal plasma aminopeptidase activity was inhibited in a 55.1% by the protease inhibitors. On the other hand, regarding the effect of protease inhibitors on reproductive performance, our results showed that the presence of protease inhibitors affected the prolificacy rate (9.2 +/- 0.26 and 9.3 +/- 0.23 vs. 8.2 +/- 0.22 total born per litter for negative control, positive control, and aminopeptidase inhibitors group, respectively; P < 0.05), having this group one kit less per delivery. We conclude that the addition of a wide variety of protease inhibitors in the rabbit semen extender negatively affects prolificacy rate. Therefore, the development of new extenders with specific aminopeptidase inhibitors would be one of the strategies to increase the bioavailability of GnRH analogues without affecting the litter size. (C) 2016 Elsevier Inc. All rights reserved.This research was supported in part by the RTA2013-00058-00-00 from INIA, the European Social Fund and the European FEDER Funds. L Casares-Crespo is supported by a scholarship from Institute Valenciano de Investigaciones Agrarias (IVIA) and the European Social Fund.Casares-Crespo, L.; Vicente Antón, JS.; Talavan, A.; Viudes De Castro, MP. (2016). Does the inclusion of protease inhibitors in the insemination extender affect rabbit reproductive performance?. Theriogenology. 85(5):928-932. doi:10.1016/j.theriogenology.2015.10.044S92893285

Kinematics and stability of high-mass protostellar disk candidates at sub-arcsecond resolution

Context. The fragmentation mode of high-mass molecular clumps and the accretion processes that form the most massive stars (M & 8 M) are still not well understood. A growing number of case studies have found massive young stellar objects (MYSOs) to harbour disk-like structures, painting a picture that the formation of high-mass stars may proceed through disk accretion, similar to that of lower mass stars. However, the properties of such structures have yet to be uniformly and systematically characterised. Massive disks are prone to fragmentation via gravitational instabilities due to high gas densities and accretion rates. Therefore, it is important to study the stability of such disks in order to put into context the role of disk fragmentation in setting the final stellar mass distribution in high-mass star forming regions. Aims. The aim of this work is to uniformly study the kinematic properties of a large sample of MYSOs and characterise the stability of possible circumstellar disks against gravitational fragmentation. Methods. We have undertaken a large observational program (CORE) making use of interferometric observations from the Northern Extended Millimetre Array (NOEMA) for a sample of 20 luminous (L > 104 L) protostellar objects in the 1.37 mm wavelength regime in both continuum and spectral line emission, reaching 0.400 resolution (800 au at 2 kpc). Results. We present the gas kinematics of the full sample and detect dense gas emission surrounding 15 regions within the CORE sample. Using the dense gas tracer CH3CN, we find velocity gradients across 13 cores perpendicular to the directions of bipolar molecular outflows, making them excellent disk candidates. The extent of the CH3CN emission tracing the disk candidates varies from 1800 − 8500 au. Analysing the free-fall to rotational timescales, we find that the sources are rotationally supported. The rotation profiles of some disk candidates are well described by differential rotation while for others the profiles are poorly resolved. Fitting the velocity profiles with a Keplerian model, we find protostellar masses in the range of ∼ 10 − 25 M. Modelling the level population of CH3CN (12K − 11K) K = 0 − 6 lines we present temperature maps and find median temperature in the range 70–210 K with a diversity in distributions. Radial profiles of the specific angular momentum (j) for the best disk candidates span a range of 1–2 orders of magnitude, on average ∼ 10−3 km s−1 pc, and follow j ∝ r 1.7, consistent with a poorly resolved rotating and infalling envelope/disk model. Studying the Toomre stability of the disk candidates, we find almost all (11 out of 13) disk candidates to be prone to fragmentation due to gravitational instabilities at the scales probed by our observations, as a result of their high disk to stellar mass ratio. In particular, disks with masses greater than ∼ 10 − 20% of the mass of their host (proto)stars are Toomre unstable, and more luminous YSOs tend to have disks that are more massive compared to their host star and hence more prone to fragmentation. Conclusions. In this work, we show that most disk structures around high-mass YSOs are prone to disk fragmentation early in their formation due to their high disk to stellar mass ratio. This impacts the accretion evolution of high-mass protostars which will have significant implications for the formation of the most massive stars

Caracterização física de frutos e sementes de goiaba-da-costa-rica, produzidos em Manaus, Amazonas Physical characterization of fruits and seeds of costa rican guavas produced in Manaus, Amazonas

A goiaba-da-costa-rica (Psidium friedrichsthalianum) é uma espécie frutífera nativa da América Central, cultivada em pomares domésticos. Visando a contribuir para o estabelecimento de técnicas de implantação e condução de plantios comerciais, foi realizada a caracterização física de frutos e sementes dessa espécie. Assim, foi verificado que o valor médio da massa fresca dos frutos foi 42,19 g, da polpa foi 39,72 g e das sementes foi 2,47g, com número em torno de 72,8 sementes por fruto. As sementes apresentam formato irregular, com valores médios de comprimento, largura e espessura de 4,29 mm, 4,11 mm e 2,68 mm, respectivamente. O fruto apresenta atributos favoráveis ao aproveitamento industrial, como o elevado rendimento em polpa (94%) e o formato globoso, levemente achatado nos pólos (valor da relação diâmetro longitudinal/diâmetro transversal = 0,83). O número elevado de sementes por fruto representa uma característica facilitadora à propagação e produção de mudas.<br>The Costa Rican guava (Psidium friedrichsthalianum) is a native fruit tree species of Central America cultivated in home gardens. The physical characterization of fruits and seeds of this species was done with the aim of contributing for the establishment of the implementation of techniques and commercial crops management. In this way, it was verified that the average fruit fresh weight was 42.19g, and pulp fresh weight was 39.72g, and seed fresh weight was 2.47g, with 72.8 seeds per fruit. The seeds are irregularly shaped, with average length, width and thickness of 4.29mm, 4.11mm and 2.68mm, respectively. The fruit presents favorable attributes for industrial exploitation, with high pulp yield (94%) and a round shape, somewhat flattened on the apex and base (longitudinal diameter/transversal diameter ratio = 0.83). The high seed number per fruit represents a characteristic that facilitates the propagation and seedling production of the species

Short-Term Effects of Muscular Denervation and Fasciotomy on Global Limb Variables during Locomotion in the Decerebrate Cat

The motor system is capable of preserving the trajectories during locomotion of task level variables such as limb length and limb orientation in the face of paralysis of major muscle groups. This compensation is accomplished by the adjustment of the kinematics of joints other than the one most affected by the paralysis. The conservation of these task level variables could be accomplished quickly by feedback regulation or intrinsic mechanics, or by a longer-term adaptive process. We investigated the immediate effects of denervation of the triceps surae muscles in one limb of stepping, decerebrate cats to determine whether task level variables were preserved by short-term regulatory or intrinsic mechanisms. We further investigated the effects of disruption of the crural fascia in conjunction with denervation of the triceps surae muscles to determine whether the system consisting of multi-articular muscles of the thigh and crural fascia provided some contribution toward the preservation of limb length and orientation. Denervation led to substantial increases in ankle yield during stance, as previously observed, but also to significant decreases in limb length during early stance. Disruption of the crural fascia did not lead to increased ankle yield but, instead, to evidence for decreased propulsion. The results suggest that the preservation of task level variables observed in other studies does not result from online error correction or intrinsic properties of the musculoskeletal system but, by inference, from longer-term neural adaptation

Impacto do fogo no componente arbóreo de uma floresta estacional semidecídua no município de Ibituruna, MG, Brasil Impact of fire on the arboreal component of a seasonal semideciduous forest in Ibituruna, southeastern Brazil

Foram realizados inventários da comunidade arbórea, da topografia e dos solos de um fragmento de floresta semidecídua com o objetivo de avaliar os impactos de um incêndio ocorrido em 1999, na estrutura da comunidade arbórea e na composição e diversidade de espécies, bem como as relações entre a severidade do incêndio e variáveis do ambiente físico. O fragmento florestal, com área de 57 ha, está localizado nas coordenadas de 21º09'S e 44º50'W, no município de Ibituruna, MG. Os inventários foram conduzidos em dois setores do fragmento. Na Encosta, foram realizados dois inventários: o primeiro, em 1997, antes do incêndio, foi feito em quinze parcelas de 5×50 m e o segundo, em 2001, posterior ao incêndio, em treze parcelas de 20×20 m. No Vale, foi conduzido em 2001 um inventário em 13 parcelas de 20×20 m distribuídas ao longo da linha de frente definida pela propagação máxima do incêndio. Nos inventários foram registradas a espécie, a circunferência à altura do peito (CAS) e a altura total de todos os indivíduos arbóreos com diâmetro à altura do peito (DAP) > 5 cm. Em cada parcela, foram obtidas variáveis topográficas, variáveis químicas e texturais do solo e gerados um fator borda e um índice de dano por fogo (IDF). O incêndio causou impactos consideráveis ao componente arbóreo da vegetação. A densidade e a área basal total de indivíduos arbóreos foram reduzidas e esta redução concentrou-se nas classes de menores diâmetros e alturas. Onde o incêndio foi mais severo (maior IDF), foram maiores as proporções de árvores mortas em pé em relação às sobreviventes, expressas tanto em densidade como em área basal. Na Encosta, as espécies que atingem menor porte na maturidade caíram na ordem de abundância relativa depois do fogo. Dois anos após o incêndio houve aumento na diversidade e riqueza de espécies de árvores provavelmente devido ao acréscimo de espécies pioneiras nas áreas abertas pelo fogo. Não foram detectadas correlações do IDF com o fator borda nem com as variáveis topográficas e do solo.<br>Surveys of the tree community, topography and soils of a fragment of tropical semideciduous forest were carried out with the purpose of assessing the impacts of a fire that struck the forest in 1999 on the community structure and tree species composition and diversity, as well as the relationship between fire severity and variables of the physical environment. The forest fragment, with an area of 57ha, is situated at 21º09'S of latitude and 44º50'W of longitude, in the municipality of Ibituruna, Minas Gerais state, Brazil. The surveys were carried out in two sectors of the fragment. There were two surveys in the Slope sector: the first, in 1997 (before the fire), within fifteen 5×50 m sample plots, and the second, in 2001 (after the fire), within thirteen 20×20 m sample plots. A single survey was carried out in the Valley sector within thirteen 20×20 m sample plots distributed along the frontline, defined by the maximum fire propagation. The surveys registered the species, the circumference at breast height and the total height of trees with diameter at breast height (dbh) > 5 cm. Topographic variables, soil chemical and textural variables, a fire damage index (FDI), and an edge factor were obtained for each sample plot. The fire caused considerable impacts to the arboreal component of the vegetation. Tree density and total basal area decreased and this was particularly concentrated in the classes of smallest diameter and height. Where fire severity was higher (> FDI), there were higher proportions of standing dead over surviving trees, expressed as both density and basal area. In the Slope sector, the species of lower stature at maturity dropped in the rank of relative abundances after the fire. Two years after the fire, there was an increase in tree species richness and diversity probably due to the addition of pioneer species in fire-opened areas. No correlations were detected between the FDI and the edge factor, not even any of the topographic or soil variables