Seasonal variation in sex ratio and sexual egg dimorphism favouring daughters in first clutches of the spotless starling

We investigated possible pre‐hatching mechanisms of sex‐differential investment by females that may contribute to offspring sex‐ratio adjustment enhancing the fitness return from reproductive effort in the spotless starling (Sturnus unicolor). We found a seasonal shift in sex ratio from daughters to sons as the season advances. Furthermore, the probability of breeding at 1‐year old and recruitment into the breeding population in daughters is associated with laying date but not with mass at fledging. The reverse is true for males which rarely bred at 1‐year old. We also found that eggs containing female embryos are significantly heavier than those containing males in spite of the slight sexual dimorphism in favour of males. This suggests maternal control of provisioning, favouring daughters that may balance sibling mortality and competition with their brothers. Our results on seasonal variation in sex ratio and differential egg provisioning are consistent with an adaptive tactic in which mothers increase their reproductive return by enhancing the probability that daughters survive and breed in their first year of life.     

In ovo injection with glycerol and insulin-like growth factor (IGF-I): hatchability,intestinal morphometry,performance, and carcass characteristics of broilers

ABSTRACT

The objective of this study was to evaluate the effects of in ovo injection with glycerol (GLY) and insulin-like growth factor (IGF-I) on hatchability, biochemical parameters, intestinal morphometry, performance, and carcass characteristics of broiler chickens. A total of 400 fertilised eggs were distributed into five experimental groups. The treatments were arranged as non-injected (control), saline solution injected (0.9% NaCl solution), GLY solution injected (10 nmol/ml), IGF-I solution injected (100 ng/ml), and GLY + IGF-I solution injected. At 17.5 d of incubation, 0.5 ml of each solution was injected into the amniotic fluid of each egg of the injected groups. The injection of different solutions did not influence the hatchability and incubation time of the eggs. Compared to intact eggs, IGF-I and IGF-I+ GLY increased (p < 0.01) the blood IGF-I at hatching. Higher hepatic glycogen was observed (p < 0.05) with GLY or IGF-I. The tested substances decreased (p = 0.02) the fructose 1,6-biphosfate phosphatase activity but did not affect glycaemia. No difference in performance was observed in the first week. Higher feed intake and weight gain with lower feed conversion ratio was obtained ( p  < 0.05) with IGF-I at 14 d. At 21 d, higher weight gain was obtained (p = 0.05) with IGF-I, GLY, IGF-I, and GLY + IGF-I, resulting (p < 0.01) in birds with greater weight gain at 35 and 42 d of age. GLY provided higher villus height in the ileum at hatching and at 7 d of age. The tested solutions increased the relative weight of the liver at hatching. At 42 d of age, no carcass characteristics were influenced. It is concluded that GLY and IGF-I, together or separately, can be used in the in ovo feeding to improve the post-hatch performance of broilers, without affecting hatchability and carcass composition.     

Kinetics of growth of Lactobacillus plantarum with glucose,organic acids (malate,citrate, acetate) and ethanol

Summary L. plantarum was grown on glucose and organic acids, i.e. malate, citrate, and acetate, frequently jointly encountered in wine and cider fermentation. The effect on fermentation patterns of different mixtures of acids as well as ethanol was studied. Specific growth rates and apparent biomass yields on glucose increased when adding citrate or malate. Acetate and ethanol were not consummed by the lactobacillus. The presence of acetate, but not ethanol, slightly decreased citrate consumption rates, but did not significantly influence glucose or malate fermentations.     

L-Rhamnose dehydrogenase of pullularia pullulans.

Growth of Pullularia pullulans on L-rhamnose induces formation of L-rhamnofuranose dehydrogenase, whichreversibly converts L-rhamnofuranose to L-rhamnono-gamma-lactone with the concomitant reduction of NAD, but not of NADP. The dehydrogenase was purified 100-fold by MnCl(2) treatment...     

The role of physical activity and fitness on the metabolic syndrome in adolescents: effect of different scores. The AFINOS Study

The aim of this study was to examine the associations of objectively measured physical activity (PA) and cardiorespiratory fitness (CRF) with different continuous metabolic syndrome (MetS) scores in adolescents. A cross-sectional sub-sample of 202 adolescents (99 girls), aged 13–17 years, were selected from the AFINOS Study. Body mass index, sum of 6 skindfold, waist circumference, systolic and diastolic blood pressure, insulin, glucose, triacylglycerol, and HDL-cholesterol levels were determined. Moderate PA (MPA), vigorous PA (VPA) and moderate to vigorous PA (MVPA) were assessed by the ActiGraph accelerometer for 7 consecutive days and CRF was estimated by the 20-m shuttle run test. Three continuous MetS scores were calculated according to the methodology of the Corpus Christi Child Heart Study (CCCHS), the Aerobic Center Longitudinal Study (ACLS), and the European Youth Heart Study (EYHS). VPA and MVPA were significantly related with CRF. Only CRF, and not patterns of PA, was inversely and independently associated with the three MetS scores although with different magnitudes (ranged: β = 0.22 to 0.36, p < 0.05). A significant VPA x CRF interaction (p = 0.011) was found using the ACLS MetS score. Trends across VPA-CRF groups were significantly different with ACLS and EYHS (p = 0.002 and p = 0.006, respectively), but not with CCCHS (p = 0.313) continuous MetS scores. These findings support the key role of CRF on the MetS and the relevance of PA, especially VPA, to provide CRF in adolescents. A unified pediatric definition of MetS might minimize the discrepancies among studies.     

TheCaesalpinia peltophoroides cell cycle under different aeration conditions

Summary Cell cycle parameters were studied inCaesalpinia peltophoroides meristems proliferating under different oxygen tensions. This species has been selected for mixed planting in degraded areas in Brazil, some of which are occasionally flooded. As the species’ adaptation to oxygen deprivation during flooding is not fully understood, the objective of this study was to characterize the meristematic activity of root cells under various oxygen regimes. Synchronous binucleate cells, induced by a pulse of caffeine, showed a cell-cycle time constant under both control (5.6 mg of O₂ per l) and oxygenated conditions (7.9 and 3.2 mg of O₂ per l). The whole cell cycle lasted 10 h, although the relative duration of metaphase and anaphase/early telophase increased in more hypoxic conditions. The species appeared to utilise oxygen diffusing from the shoot to the root system to maintain cell division and root growth.