3,360 research outputs found
Efeito da vitamina C no ganho de peso e em parâmetros hematológicos de tambaqui.
O objetivo deste trabalho foi avaliar o efeito da suplementação dietária com ácido L-ascórbico (vitamina C) no ganho de peso e em parâmetros hematológicos de juvenis de tambaqui, Colossoma macropomum
Metabolic adjustments in two Amazonian cichlids exposed to hypoxia and anoxia.
The effects of graded hypoxia on the physiological and biochemical responses were examined in two closely related species of cichlids of the Amazon: Astronotus crassipinnis and Symphysodon aequifasciatus. Ten fish of each species were exposed to graded hypoxia for 8 h in seven oxygen concentrations (5.92, 3.15, 1.54, 0.79, 0.60, 0.34, and 0.06 mg O2 L- 1), with the aim to evaluate hypoxia tolerance and metabolic adjustments, where plasma glucose and lactate levels, hepatic and muscle glycogen contents, and maximum enzyme activities (PK, LDH, MDH and CS) in skeletal and cardiac muscles were measured. Another experimental set was done to quantify oxygen consumption (MO2) and opercular movements in two oxygen concentrations. Hypoxia tolerance differed between the two species. Astronotus crassipinnis was able to tolerate anoxia for 178 min while S. aequifasciatus was able to withstand 222 min exposure in deep hypoxia (0.75 mg O2 L- 1). Suppressed MO2 was observed during exposure to 0.34 (A. crassipinnis) and 0.79 mg O2 L- 1 (S. aequifasciatus), while opercular movements increased in both species exposed to hypoxia. Higher levels of muscle and liver glycogen and larger hypoxia-induced increases in plasma glucose and lactate were observed in A. crassipinnis, which showed a higher degree of hypoxia tolerance. Changes in enzyme levels were tissue-specific and differed between species suggesting differential abilities in down-regulating oxidative pathways and increasing anaerobic metabolism. Based on the present data, we conclude that these animals are good anaerobes and highly adapted to their environment, which is allowed by their abilities to regulate metabolic pathways and adjust their enzyme levels
Será Choque Séptico? Um Caso Raro de Choque Distributivo
The authors report a rare case of shock
in a patient without significant clinical
history, admitted to the intensive care unit
for suspected septic shock. The patient
was initially treated with fluid therapy
without improvement. A hypothesis of
systemic capillary leak syndrome was
postulated following the confirmation of severe hypoalbuminemia, hypotension,
and hemoconcentration - a combination
of three symptoms typical of the disease.
The authors discussed the differential
diagnosis and also conducted a review of
the diagnosis and treatment of the disease
Change of Parameters of the Koiwa–Hasiguti Dynamic Dislocation Relaxation in Nanostructured and Polycrystalline Zirconium after Severe Plastic Deformation and Annealing
The temperature dependences of acoustic properties of nanostructured and polycrystalline zirconium are investigated in the temperature range of 100–340 K. The effect of severe plastic deformation and subsequent annealing on key parameters of the Koiwa–Hasiguti acoustic relaxation in zirconium is studied in detail. It is established that, due to intensive plastic deformation, the relaxation strength considerably increases, and the temperature and the width of the corresponding relaxation peak systematically decrease with reduction of the mean grain size in the samples. Annealing leads to a partial recovery of the relaxation strength and the peak temperature back to the initial values in undeformed samples, but the width of the relaxation peak shows an additional decrease. The majority of the effects observed can be explained by changes in dislocation subsystems of the samples during intensive plastic deformation and annealing. An influence of a random scatter of the relaxation time on the main parameters of the Koiwa–Hasiguti peak is established using the statistical analysis based on the lognormal distribution. It is shown that the parameter β of the lognormal distribution determines the width, height, and asymmetry of the peak and also allows estimating the relaxation strength from the peak height. An algorithm for retrieving the parameter β from experimental data is presented
Crystallization in a model glass: influence of the boundary conditions
Using molecular dynamics calculations and the Voronoi tessellation, we study
the evolution of the local structure of a soft-sphere glass versus temperature
starting from the liquid phase at different quenching rates. This study is done
for different sizes and for two different boundary conditions namely the usual
cubic periodic boundary conditions and the isotropic hyperspherical boundary
conditions for which the particles evolve on the surface of a hypersphere in
four dimensions. Our results show that for small system sizes, crystallization
can indeed be induced by the cubic boundary conditions. On the other hand we
show that finite size effects are more pronounced on the hypersphere and that
crystallization is artificially inhibited even for large system sizes.Comment: 11 pages, 2 figure
Measuring molecular abundances in comet C/2014 Q2 (Lovejoy) using the APEX telescope
Comet composition provides critical information on the chemical and physical
processes that took place during the formation of the Solar system. We report
here on millimetre spectroscopic observations of the long-period bright comet
C/2014 Q2 (Lovejoy) using the Atacama Pathfinder Experiment (APEX) band 1
receiver between 2015 January UT 16.948 to 18.120, when the comet was at
heliocentric distance of 1.30 AU and geocentric distance of 0.53 AU. Bright
comets allow for sensitive observations of gaseous volatiles that sublimate in
their coma. These observations allowed us to detect HCN, CH3OH (multiple
transitions), H2CO and CO, and to measure precise molecular production rates.
Additionally, sensitive upper limits were derived on the complex molecules
acetaldehyde (CH3CHO) and formamide (NH2CHO) based on the average of the
strongest lines in the targeted spectral range to improve the signal-to-noise
ratio. Gas production rates are derived using a non-LTE molecular excitation
calculation involving collisions with H2O and radiative pumping that becomes
important in the outer coma due to solar radiation. We find a depletion of CO
in C/2014 Q2 (Lovejoy) with a production rate relative to water of 2 per cent,
and relatively low abundances of Q(HCN)/Q(H2O), 0.1 per cent, and
Q(H2CO)/Q(H2O), 0.2 per cent. In contrast the CH3OH relative abundance
Q(CH3OH)/Q(H2O), 2.2 per cent, is close to the mean value observed in other
comets. The measured production rates are consistent with values derived for
this object from other facilities at similar wavelengths taking into account
the difference in the fields of view. Based on the observed mixing ratios of
organic molecules in four bright comets including C/2014 Q2, we find some
support for atom addition reactions on cold dust being the origin of some of
the molecules.Comment: 10 pages, 7 figures, to be published in MNRA
Determination of the Alignment between Information Systems and Marketing
This paper addresses the challenge of measuring alignment. Two different approaches are developed: one based on seven dimensions of strategic orientation; and one based on eight dimensions of market orientation. A formula is developed for the calculation of alignment. The formula is applied to a survey of 175 large New Zealand companies. Analyses of the results suggest overall similarity between the strategic orientation and market orientation approaches, yet with distinct differences which might impact on business performance
Efeito de diferentes métodos de enxertia e genótipos no pegamento e desenvolvimento de mudas de bacurizeiro (Platonia insignis Mart.).
O bacurizeiro, espécie frutífera tropical da família Clusiaceae, é originário do Estado do Pará, onde localiza-se o centro de diversidade da espécie e está concentrada ampla variação de forma e tamanho de frutos, rendimento e qualidade de polpa, dentre outras características de interesse. A dispersão da espécie ocorreu por toda a região Norte, além do Nordeste Ocidental ou Meio-Norte, onde forma densos povoamentos, especialmente nas áreas de "chapadas", e dos estados de Tocantins e Mato Grosso (Ferreira et al. 1987; Carvalho & Müller, 1996; Cavalcante, 1996). Embora seja uma espécie ainda não domesticada, o bacurizeiro apresenta elevado potencial para exploração econômica pela larga aceitação de seus frutos tanto para consumo in natura como na forma processada, podendo, a médio e/ou longo prazos, estabelecer-se como uma nova opção para o mercado interno e externo de frutas exóticas. A dificuldade de propagação, aliada ao longo período de juvenilidade, é atualmente o fator de maior limitação ao cultivo racional do bacurizeiro. A propagação por sementes, além de não ser a mais recomendada para cultivos comerciais, é dificultada pelo longo período requerido para que o processo de germinação seja completado e pelo baixo percentual e desuniformidade de germinação das sementes (Carvalho et al. 1998; Carvalho et al. 1999). A propagação vegetativa por enxertia, que é a forma mais apropriada de propagação de fruteiras com fins comerciais, tem se mostrado eficiente também nessa espécie (Carvalho & Müller, 1996; Souza et al. 2000). Entretanto, na literatura especializada a disponibilidade de informações científicas sobre essa forma de propagação envolvendo o bacurizeiro é, ainda, muito incipiente. Estudos visando estabelecer métodos de enxertia eficientes, época adequada de coleta de propágulos, idade do porta-enxerto e compatibilidade entre enxerto e porta-enxerto, são, portanto, necessários para o completo domínio dessa forma de propagação na espécie. O objetivo deste trabalho foi avaliar o efeito de diferentes métodos de enxertia e genótipos no pegamento e desenvolvimento de mudas de bacuri em condições de viveiro
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