17,285 research outputs found
Utilização de extrato de própolis verde no resfriamento de sêmen equino
Seminal cooling aims to prolong spermatic lifespan and fertilizing capacity due to reduction in energy metabolism of spermatozoa, providing enough period for transportation from the stallion to the mare. Cooling process can result in ultraestructural, biochemical and functional alterations to spermatozoa. The aim of this study was to evaluate the effect of green propolis hydroalcoholic extract (GPHE) added into equine semen extender and stored at 5ºC. For that, semen was collected from five stallions (Crioulo and Quarter horse) in four opportunities (n=20). These ejaculates were submitted to the following treatments: control group (skim milk glucose semen extender) and groups with the addition of green propolis extract in different concentrations (2,5μl/mL; 5μl/mL; 7,5μl/mL; 10μl/mL). Seminal analyses included motility, mitochondrial functionality, integrity of plasma membrane, DNA and acrossome, being used ejaculates with ≥70% of intact cells. Evaluation was performed at 0; 30; 60; 120; 180; 240; 300; 360 and 1440 minutes during cooled storage at 5ºC. Seminal parameters declined according to storage time in all treatments (P<0.05). Sperm motility reached 0% in 360 minutes in the groups with propolis. The addition of green propolis extract into the semen extender maintained structural characteristics of stallion sperm cell, however it was detrimental no functional characteristics.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESO resfriamento seminal tem como intuito o prolongamento da viabilidade espermática e capacidade fecundante pela redução no metabolismo energético dos espermatozoides, proporcionando período hábil para transporte do sêmen do garanhão até a égua. O processo de resfriamento pode resultar em alterações ultraestruturais, bioquímicas e funcionais na célula espermática. O objetivo deste experimento foi avaliar o efeito do extrato de própolis verde adicionado ao diluente para resfriamento de sêmen equino a 5ºC. Para isso, foram coletados 4 ejaculados de 5 garanhões da raça Crioula e Quarto de Milha (n=20). Estes ejaculados foram submetidos aos seguintes tratamentos: controle (diluente a base de leite desnatado) e grupos com adição de extrato de própolis verde em diferentes concentrações (2,5μl/mL; 5μl/mL; 7,5μl/mL; 10μl/mL). As análises espermáticas incluíram motilidade, funcionalidade mitocondrial, integridade de membrana plasmática, DNA e acrossoma, sendo utilizados ejaculados contendo ≥70% de células íntegras ás 0h. As avaliações foram realizadas ás 0; 30; 60; 120; 180; 240; 300; 360 e 1440 minutos durante o resfriamento a 5ºC. Os parâmetros seminais diminuíram de acordo com o aumento do tempo em resfriamento em todos tratamentos (P<0,05). A motilidade espermática atingiu 0% em 360 minutos nos tratamentos com própolis. A adição de extrato de própolis verde ao diluente de resfriamento seminal manteve as características estruturais da célula espermática equina, no entanto prejudicou as caraterísticas funcionais
Experimentation with Accumulation
We study signal-dependent experimentation in the presence of accumulation and show that the passive-learner’s action surprisingly coincides with the experimentor’s when the unknown term is the one determining the decay rate of the stock, while they differ when the parameter being learned is the one measuring the accumulation rate. These results highlight the importance of the dynamic structure of the problem in signal-dependent experimentation. Moreover, they have important consequences for the pollutionaccumulation debate currently in progress.
Manifestações dermatológicas em pacientes portadores do vírus da imunodeficiência humana.
Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Clínica Médica, Curso de Medicina, Florianópolis, 200
Is CDM an effective CCDM cosmology?
We show that a cosmology driven by gravitationally induced particle
production of all non-relativistic species existing in the present Universe
mimics exactly the observed flat accelerating CDM cosmology with just
one dynamical free parameter. This kind of scenario includes the creation cold
dark matter (CCDM) model [Lima, Jesus & Oliveira, JCAP 011(2010)027] as a
particular case and also provides a natural reduction of the dark sector since
the vacuum component is not needed to accelerate the Universe. The new cosmic
scenario is equivalent to CDM both at the background and perturbative
levels and the associated creation process is also in agreement with the
universality of the gravitational interaction and equivalence principle.
Implicitly, it also suggests that the present day astronomical observations
cannot be considered the ultimate proof of cosmic vacuum effects in the evolved
Universe because CDM may be only an effective cosmology.Comment: 6 pages, 2 figures, changes in the abstract, introduction, new
references and typo correction
Continuous Quantum Error Correction Through Local Operations
We propose local strategies to protect global quantum information. The
protocols, which are quantum error correcting codes for dissipative systems,
are based on environment measurements, direct feedback control and simple
encoding of the logical qubits into physical qutrits whose decaying transitions
are indistinguishable and equally probable. The simple addition of one extra
level in the description of the subsystems allows for local actions to fully
and deterministically protect global resources, such as entanglement. We
present codes for both quantum jump and quantum state diffusion measurement
strategies and test them against several sources of inefficiency. The use of
qutrits in information protocols suggests further characterization of
qutrit-qutrit disentanglement dynamics, which we also give together with simple
local environment measurement schemes able to prevent distillability sudden
death and even enhance entanglement in situations in which our feedback error
correction is not possible.Comment: Accepted for publication in Phys. Rev.
Asteroseismology and Magnetic Cycles
Small cyclic variations in the frequencies of acoustic modes are expected to
be a common phenomenon in solar-like pulsators, as a result of stellar magnetic
activity cycles. The frequency variations observed throughout the solar and
stellar cycles contain information about structural changes that take place
inside the stars as well as about variations in magnetic field structure and
intensity. The task of inferring and disentangling that information is,
however, not a trivial one. In the sun and solar-like pulsators, the direct
effect of the magnetic field on the oscillations might be significantly
important in regions of strong magnetic field (such as solar- / stellar-spots),
where the Lorentz force can be comparable to the gas-pressure gradient. Our aim
is to determine the sun- / stellar-spots effect on the oscillation frequencies
and attempt to understand if this effect contributes strongly to the frequency
changes observed along the magnetic cycle. The total contribution of the spots
to the frequency shifts results from a combination of direct and indirect
effects of the magnetic field on the oscillations. In this first work we
considered only the indirect effect associated with changes in the
stratification within the starspot. Based on the solution of the wave equation
and the variational principle we estimated the impact of these stratification
changes on the oscillation frequencies of global modes in the sun and found
that the induced frequency shifts are about two orders of magnitude smaller
than the frequency shifts observed over the solar cycle.Comment: 4 pages, 6 figures, ESF Conference: The Modern Era of Helio- and
Asteroseismology, to be published on 3 December 2012 at Astronomische
Nachrichten 333, No. 10, 1032-103
Efficiency of the Portuguese metros. is it different from other European metros?
This research analyses the performance of Portuguese metros in the European context. By means of two non-parametric benchmarking techniques, respectively performance indicators and data envelopment analysis, we compute the efficiency of 37 European metros. In order to provide statistical inference and robustness to our results we apply the recent technique of bootstrap. We also use the partial frontiers (order-m) to identify outliers and the double bootstrap procedure in a second stage methodology to take into account the influence of the operational environment. The results show important levels of inefficiency both in the Portuguese metros and in other European metros.Metro; Efficiency; Portugal; Performance Indicator; Data Envelopment Analysis
Impact of stellar companions on precise radial velocities
Context: With the announced arrival of instruments such as ESPRESSO one can
expect that several systematic noise sources on the measurement of precise
radial velocity will become the limiting factor instead of photon noise. A
stellar companion within the fiber is such a possible noise source. Aims: With
this work we aim at characterizing the impact of a stellar companion within the
fiber to radial velocity measurements made by fiber-fed spectrographs. We
consider the contaminant star either to be part of a binary system whose
primary star is the target star, or as a background/foreground star. Methods:
To carry out our study, we used HARPS spectra, co-added the target with
contaminant spectra, and then compared the resulting radial velocity with that
obtained from the original target spectrum. We repeated this procedure and used
different tunable knobs to reproduce the previously mentioned scenarios.
Results: We find that the impact on the radial velocity calculation is a
function of the difference between individual radial velocities, of the
difference between target and contaminant magnitude, and also of their spectral
types. For the worst-case scenario in which both target and contaminant star
are well centered on the fiber, the maximum contamination for a G or K star may
be higher than 10 cm/s, on average, if the difference between target and
contaminant magnitude is < 10, and higher than 1 m/s if <
8. If the target star is of spectral type M, < 8 produces the same
contamination of 10 cm/s, and a contamination may be higher than 1 m/sComment: Accepted for publication in A&A on 29/12/2019 - 14 page
Looking for a break in Spanish Inflation Data in the early eighties and assessing persistence
Using the Bai-Perron test, we look for a shift in the conditional mean of an AR representation of Spanish CPI inflation over the period: 1978-2006. It is clear that Spain, as most OECD economies, experienced an inflation slowdown in the early eithgties, which can be related to some policy measures undertook by the government coming out of the 1982 elections. It is shown, that when the break is accounted for, there are no signs of persistence in Spanish CPI inflation.inflation persistence; structural breaks; monetary policy
Doença renal crónica: uma abordagem fenomenológica das experiências de pessoas transplantadas
Dissertação de mestrado em EnfermagemA Doença Renal Crónica é um problema de saúde pública em todo o mundo que consiste na lesão
renal e, geralmente, na perda progressiva e irreversível da função dos rins.
Vivenciar uma transição saúde-doença, nomeadamente a Doença Renal Crónica (DRC), comporta
alterações profundas na vida de quem experimenta um processo desta natureza. O número de
horas que passam nas unidades de diálise altera a rotina de vida diária, os efeitos secundários
dos tratamentos são sentidos como incapacitantes e todo o sistema familiar vive o sofrimento da
pessoa com esta doença.
A investigação de índole exploratória e fenomenológica visou explorar, descrever e interpretar o
significado que as pessoas transplantadas atribuem às experiências vividas durante a frequência
de um programa regular de hemodiálise. Participaram no estudo 6 pessoas submetidas a
transplante renal após hemodiálise, tendo sido inquiridas através de entrevista não estruturada.
As narrativas foram analisadas à luz da perspetiva de van Manen (2014). Da análise efetuada
emergiram três temas principais e respetivos subtemas, os quais ajudam a compreender a
estrutura da experiência em estudo: Disrupção da Vida, Adaptação e O (re)começo.
Os resultados permitem uma compreensão mais abrangente das experiências vividas pelas
pessoas com DRC e contribuem para a orientação das práticas dos enfermeiros no sentido de que
mais e melhores cuidados possam ser prestados às pessoas que vivenciam transições saúdedoença
motivadas pela DRC e, consequentemente, que as vivenciem de forma mais saudável.Chronic Kidney Disease is a worldwide public health problem, which consists of renal injury and,
usually, progressive and irreversible loss of kidney function.
Experiencing a transition health-disease, namely Chronic Kidney Disease (CKD), involves profound
changes in the lives of those who experience such a process. The number of hours spent in dialysis
units changes the daily life routine, treatments’ side effects are felt as disabling and the entire
family system lives the pain of people with CKD.
The phenomenological and exploratory research’s nature has the purpose to study the meaning
that people transplanted give to the experiences during the frequency of a regular haemodialysis
program. 6 people submitted to renal transplantation after haemodialysis participated in the study,
having been surveyed through unstructured interview. The narratives were analysed under Max van
Manen’s (2014) perspective. From the analysis performed emerged three main themes and their
respective subthemes, which helped to understand the structure of the experience under study:
Disruption of Life, Adaptation and The (re) start.
The results allow a more comprehensive understanding of the people with CKD’s experiences, and
can make a contribution in guiding the practices of nurses by being able to provide more and better
care to people who live transitions health-disease motivated by CKD and, thereafter, experience
them in a healthier way
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