51 research outputs found
Follicular growth divergence: effect in the oocyte competence for in vitro embryo production
The oocyte growth in the ovarian follicle
is determined by several factors which influence its
viability and ability for the in vitro development. These
factors include: follicular size, estrous cycle day, atresy
level and influence of other follicles, such as dominant
follicle (DF). The phase of DF selection is visualized by
ultrasound as it increases in the diameter of the DF, while
other wave follicles stop their growth or undergo
regression. These changes that occur in the diameter
reflect the important endocrine, paracrines and
autocrines alterations that follow or precede this critical
moment of the folicle development; in turn, they can
influence the oocyte quality and the ability to the in vitro
development. The ovum pick-up following in vitro
fertilization (IVF) of the oocyte from gotten alive givers
and high genetic value has been one of the expanding
technique in the world, over all regard to the important
genetic increment in the improvement of the flock.
However, variability in the results of the in vitro
embryo bovine development exists and, in average,
only 30% to 40% of the matured oocyte will develop
until blastocyst.O crescimento do oócito dentro do folículo
ovariano é determinado por vários fatores que
influenciam sua viabilidade e competência para o
desenvolvimento in vitro. Estes fatores incluem tamanho
folicular, dia do ciclo estral, nível de atresia e influência
de outros folículos, tal como o folículo dominante (FD).
A fase de seleção do FD é visualizada por ultrasonografia
como um rápido aumento no diâmetro do
FD, enquanto os outros folículos da mesma onda
cessam seu crescimento e/ou regridem. Estas
mudanças que ocorrem no diâmetro refletem as
importantes alterações endócrinas, parácrinas e
autócrinas que acompanham ou antecedem este
momento crítico do desenvolvimento folicular e, por sua
vez, podem influenciar a qualidade do oócito e a
competência para o desenvolvimento in vitro. A
aspiração folicular conduzida por ultra-sonografia e
posterior fecundação in vitro dos oócitos obtidos de
doadoras vivas e de alto valor genético tem sido uma
técnica em franca ascensão no mundo, sobretudo
devido ao importante incremento no melhoramento
genético do rebanho. Porém, existe variabilidade nos
resultados do desenvolvimento in vitro de embriões
bovino e, em média, apenas 30% a 40% dos oócitos
maturados se desenvolvem até o estádio de blastocisto
Portuguese Ministers, 1851-1999: Social Background and Paths to Power
Disponível em:
http://193.136.113.6/Opac/Pages/Search/Results.aspx?SearchText=UID=bb8aa8d5-c6b6-466a-81bb-fe8a67693cee&DataBase=10449_UNLFCSHThis paper provides an empirical analysis of the impact of regime changes in the composition and patterns of recruitment of the Portuguese ministerial elite throughout the last 150 years. The ‘out-of-type’, violent nature of most regime transformations accounts for the purges in and the extensive replacements of the political personnel, namely of the uppermost officeholders. In the case of Cabinet members, such discontinuities did not imply, however, radical changes in their social profile. Although there were some significant variations, a series of salient characteristics have persisted over time. The typical Portuguese minister is a male in his midforties, of middle-class origin and predominantly urban-born, highly educated and with a state servant background. The two main occupational contingents have been university professors - except for the First Republic (1910-26) - and the military, the latter having only recently been eclipsed with the consolidation of contemporary democracy. As regards career pathways, the most striking feature is the secular trend for the declining role of parliamentary experience, which the democratic regime did not clearly reverse. In this period, a technocratic background rather than political experience has been indeed the privileged credential for a significant proportion of minister
Molecular structure and developmental expression of zebrafish atp2a genes
[[abstract]]We isolated two atp2a genes, atp2a1 and atp2a2a, from embryonic zebrafish. Amino acid sequences deduced from zebrafish atp2a genes are aligned with orthologue proteins from other species, the results showed that they share high percentage of identities (82%–94%) and acidic pIs (5.03–5.33). Whole mount in situ hybridization experiments showed that atp2a1 and atp2a2a are maternal inherited genes which can be detected at 1-cell stage embryos and express in the entire animal pole from 6 hours post-fertilization (hpf) to 12 hpf. At the later stages (48–96 hpf), expression of atp2a1 was restricted in head and trunk muscles as well as in some neurons. In contrast to the strongly expression of atp2a1 in head muscle, expression of atp2a2a was detected in head muscle in a fainter manner. In addition, transcripts of atp2a2a were observed in the developing heart during early cardiogenesis. The present studies not only help us to comparatively analyze atp2a genes across species, but also provide useful information about expressions during early embryogenesis that will help in further investigations of functional studies of Atp2a in the future.[[incitationindex]]SCI[[booktype]]紙
CUBES: a UV spectrograph for the future
In spite of the advent of extremely large telescopes in the UV/optical/NIR range, the current generation of 8-10m facilities is likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (>40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R>20,000, although a lower-resolution, sky-limited mode of R ~ 7,000 is also planned. CUBES will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the Phase B dedicated to detailed design and construction. First science operations are planned for 2028. In this paper, we briefly describe the CUBES project development and goals, the main science cases, the instrument design and the project organization and management
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
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