Análise comparativa entre a fecundidade de Dilocarcinus pagei Stimpson e Sylviocarcinus australis Magalhães & Turkay (Crustacea, Decapoda, Trichodactylidae) no Pantanal do Rio Paraguai, Porto Murtinho, Mato Grosso do Sul

The aim of this study was to estimate the fecundity of Dilocarcinus pagei Stimpson, 1861 and Sylviocarcinus australis Magalhães & Turkay, 1996, collected in the Paraguay River, Porto Murtinho County, State of Mato Grosso do Sul, Brazil, between coordinates 21º42,000'S 57º33,649'W and 21º41,449'S 57º33,770'W, in the period of April 1999 to March 2000. After general collection procedures, the specimens were measured and processed in laboratory conditions. The river water crab species hatch like juveniles and, frequently, female specimens were observed carrying eggs in different stages of development, besides juveniles and eggs at the same time. It was apparent in the frequency distributions that D. pagei has a carapace width average greater than S. australis. The number of eggs and juveniles transported varied amongst species and amongst size class. A size superposition was observed between young and adult females for both species. According to the calculated fecundity index, D. pagei presented slightly more elevated values (7.41) than S. australis (6.65). Eggs are spherical and are not adhering to pleopods. Egg size did not varied during development, continuing with 2mm diameters.

Forced convection to laminar flow of liquid egg yolk in circular and annular ducts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ovarian development in Meliponine bees (Hymenoptera: Apidae): the effect of queen presence and food on worker ovary development and egg production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic characterization of egg weight, egg production and age at first egg in quails

O objetivo neste estudo foi obter estimativas de parâmetros genéticos para as características peso do ovo, produção de ovos em 189 dias de postura e dia do primeiro ovo em codornas de três linhagens de postura e uma de corte. Os dados foram analisados por meio de procedimentos bayesianos usando amostragem de Gibbs. As estimativas de herdabilidade para peso do ovo, produção de ovos em 189 dias de postura e dia do primeiro ovo foram, respectivamente, para a linhagem amarela, 0,31; 0,84 e 0,53; azul, 0,14; 0,82 e 0,60; vermelha, 0,70; 0,96 e 0,75; e de corte, 0,73; 0,96 e 0,72. As correlações genéticas entre peso do ovo e produção de ovos em 189 dias de postura, peso do ovo e dia do primeiro ovo e, produção de ovos em 189 dias de postura e dia do primeiro ovo foram, para amarela, 0,58; -0,77; e -0,90; azul, 0,09; -0,01; e -0,95; vermelha, 0,09; 0,03; e -0,76; e de corte, -0,18; 0,19 e -0,91. A partir das probabilidades de superposição das distribuições posteriories dos parâmetros, as linhagens dividem-se em dois grupos distintos: um com as linhagens amarela e azul e outro com as linhagens vermelha e de corte.

Continuous pasteurization of egg yolk: Thermophysical properties and process simulation

This article presents empirical correlations to predict the density, specific heat, thermal conductivity and rheological power-law parameters of liquid egg yolk over a temperature range compatible with its industrial thermal processing (0-61 C). Moreover, a mathematical model for a pasteurizer that takes into account the spatial variation of the overall heat transfer coefficient throughout the plate heat exchanger is presented, as are two of its simplified forms. The obtained correlations of thermophysical properties are applied for the simulation of the egg yolk pasteurization, and the obtained temperature profiles are used for evaluating the extent of thermal inactivation. A detailed simulation example shows that there is a considerable deviation between the designed level of heat treatment and that this is predicted through process simulation. It is shown that a reliable mathematical model, combined with specialized thermophysical property correlations, provide a more accurate design of the pasteurization equipment that ensures effective inactivation, while preserving nutritional and sensorial characteristics.

Mantispa minuta Fabricius (Neuroptera : Mantispidae) on egg sacs of the orb-weaver spider Parawixia bistriata (Araneidae) in forests of Eucalyptus grandis in Brazil

This is the first report of the interaction between the two entomophagous agents Mantispa minuta Fabricius (Mantispidae) and Parawixia bistriata Rengger, an orb-weaver spider (Araneidae). From egg sacs kept in the laboratory we observed the emergence of adult neuropterans followed by the emergence of a high number of spiderlings. This association illustrates the interactions among the invertebrate predators coexisting in Eucalyptus plantations managed without chemical treatment, in the State of São Paulo, Brazil.

EFFECTS OF CAFFEINE ON FECUNDITY, EGG-LAYING CAPACITY, DEVELOPMENT TIME AND LONGEVITY IN DROSOPHILA-PROSALTANS

In Drosophila prosaltans reared on culture medium with caffeine (50-mu-g/ml, 100-mu-g/ml, 1000-mu-g/ml and 1500-mu-g/ml), fecundity decreased with increasing dosage. Other effects were (a) an approximately one day increase in development time of flies at 1000 and 1500-mu-g/ml, (b) a decrease of egg laying capacity, with increasing dosage and (c) a decrease of longevity when virgin males and females or mated males were analyzed. Mated treated females, however showed, in most experiments, greater longevity than the controls, thus suggesting a benefit of the partial blockage of reproduction caused by caffeine.

Rheological properties and fluid dynamics of egg yolk

The rheological behavior of egg yolk was studied at a range of temperatures (277-333 K) using a concentric cylinder viscometer. Rheological behavior was pseudoplastic and flow curves fitted by the power law model. The consistency and behavior indexes, dependent on temperature, were expressed by an Arrhenius-type equation. The rheological parameters, together with experimental values of pressure loss in tube flow were used to calculate friction factors. The good agreement between predicted and observed values confirmed the reliability of the equations proposed for describing the flow behavior of the egg yolk. (c) 2005 Published by Elsevier Ltd.

Viscoelasticity of frozen/thawed egg yolk

Dynamic rheological measurements indicate that the gel formed during freezing is based on physical aggregation rather than chemical binding, with a nonhomogeneous structure. The gelation was highly dependent on frozen storage temperature in the range -10 to -14 degrees C, but there was no appreciable difference in the range -14 to -24 degrees C. When yolk was maintained motionless and supercooled at -10 degrees C and -12 degrees C for 23 hr, no change in the complex modulus, G*, was observed, but there was a considerable increase when yolk was disturbed and became frozen at the same temperatures for the same time.

Density, heat capacity and thermal conductivity of liquid egg products

Density, heat capacity and thermal conductivity of liquid egg products, such as egg white, egg yolk, whole egg and various white and yolk blends, were determined as affected by temperature and water content ranging from 273 to 311 K and 51.8 to 88.2% (mass), respectively. Polynomial models fitted the experimental data very well, showing a linear relationship both for temperature and water content. (c) 2005 Published by Elsevier Ltd.

Rhodocyclus gelatinosus biomass for egg yolk pigmentation

Biomass of the photosynthetic bacterium Rhodocyclus gelatinosus was used at different levels in laying hens' rations as a xanthophyll source. Sixty-four hens were used in the experiment that investigated the effects of different biomass concentrations on weight gain, egg production, egg weight, and yolk color as compared with a control group that received no biomass supplementation in the ration. Yolk color was scored by means of a color fan. All concentrations tested were able to provide yolk color scores higher than those provided by the control group. The pigment deposition began after 24 h of administration and reached a plateau around the twentieth day. Each increase in the supplementation level led to an additional increase on yolk color scores. Yolk colors of all treatments that received R. gelatinosus biomass differed significantly from the control group and from each other, corroborating that the increase in the biomass supplementation had a positive effect on color increase. Body weight loss occurred in all treatments. Egg production did not increase with the biomass addition, while a significant increase in egg weight was observed in the treatments that received the product.