Patterns of growth hormone-releasing factor and somatostatin secretion into the hypophysial-portal circulation of the rat

The interrelation between the secretion of two hypophysiotropic peptides, growth hormone-releasing factor (GRF) and somatostatin (SRIF), in the generation of episodic growth hormone (GH) secretion was inferred from direct measurements of immunoreactive GRF and immunoreactive SRIF concentrations in the hypophysial-portal plasma of the rat. Secretion of immunoreactive GRF was found to be episodic, with maximal concentrations present during periods of expected GH secretory episodes. Secretion of immunoreactive GRF was accompanied by a moderate reduction in portal plasma levels of immunoreactive SRIF. Passive immunoneutralization of SRIF was associated with increased concentrations of immunoreactive GRF in hypophysial-portal plasma. On the basis of these observations, it appears that each GH secretory episode is initiated by pulsatile secretion of immunoreactive GRF into the portal circulation, which is preceded by or is concurrent with a moderate reduction of inhibitory tone provided by portal immunoreactive SRIF. These experiments provide direct insights into central and adenohypophysial mechanisms by which GRF and SRIF interact to generate episodic secretion of GH.     

Identification of Polymorphisms in the Osteopontin Gene and Their Associations with Certain Semen Production Traits of Water Buffaloes in the Brazilian Amazon

The osteopontin gene may influence the fertility of water buffaloes because it is a protein present in sperm. The aim of this work was to identify polymorphisms in this gene and associate them with fertility parameters of animals kept under extensive grazing. A total of 306 male buffaloes older than 18 months, from two farms, one in the state of Amapá and the other in the state of Pará, Brazil were used in the study. Seven SNPs were identified in the regions studied. The polymorphisms were in gene positions 1478, 1513 and 1611 in the region 5′upstrem and positions 6690, 6737, 6925 and 6952 in the region amplified in intron 5. The SNPs were associated with the traits, namely scrotal circumference, scrotal volume, sperm motility, sperm concentration and sperm pathology. There were significant SNPs (p < 0.05) for all the traits. The SNP 6690 was significant for scrotal circumference, sperm concentration, sperm motility and sperm pathology and the SNP 6737 for scrotal volume. The genotype AA of SNP 6690 presented the highest averages for scrotal circumference, sperm concentration and motility and the lowest total number of sperm pathologies. For the scrotal volume trait, the animals with the largest volume were correlated with the presence of the genotype GG of SNP 6737. These results indicate a significance of the osteopontin gene as it seems to exert a substantial influence on the semen production traits of male buffaloes.     

Yeast extract on growth,nutrient utilization and haemato‐immunological responses of Nile tilapia

Dietary supplementation (0, 10, 20, 40, 60, 80 g kg^?1) of a nucleotide source (NuPro^®) was evaluated on growth, nutrient utilization, haemato‐immunological responses and resistance to experimental infection of Nile tilapia. Fish (2.63 ± 0.63 g) were fed experimental diets to satiation three times a day for 75 days. Feed intake increased linearly with increasing levels of NuPro^® promoting higher weight gain (P < 0.05). Survival, feed conversion and protein retention were not affected. Following the growth trial, fish were challenged with Aeromonas hydrophila by intraperitoneal injection. Survival and innate immune responses (phagocytosis and lysozyme activity) were not significantly affected. However, among the haematological variables, thrombocyte, leucocyte and monocyte counts increased linearly (P < 0.05). The indirect measurement of digestibility in juvenile Nile tilapia (122.32 ± 11 g) indicated a linear decrease in protein (1.41%), dry matter (5.72%) and energy (4.10%) digestibility coefficients as dietary supplementation increased (P < 0.05). NuPro^® showed to be a beneficial additive to be supplemented in diets for juvenile Nile tilapia, providing 32.8% increase in feed intake and 28.8% in weight gain, as well as in thrombocyte, leucocyte and monocyte counts in blood, possibly indicating a more efficient defence response in the highest dietary supplementation levels tested.     

Thermal and Chemical Properties of Gelatin from Tilapia (Oreochromis niloticus) Scale

ABSTRACT

Gelatin from the scale of Nile tilapia was extracted and characterized chemically, thermally, and structurally. Scales of Nile tilapia were subjected to acid pretreatment and extraction with water at 60°C. The process yielded 12.1% (m/m) on a dry basis. The 6.67% gelatin solution had a gel strength of 233.5 ± 14g. The amino acid composition revealed that 20.02% was comprised of imino acids and glycine (34.49%) as the most abundant amino acids. The scale gelatin had α1, α2, and β subunits and was thermally stable up to 200ºC. The Fourier transform infrared spectrum showed absorption in the regions of amides A, I, II, and III. The characterization of tilapia scale gelatin showed that the obtained product was similar to commercial gelatin, thereby demonstrating its potential application.     

Origin of and resulting floristic composition from seedbanks in agroforestry systems of Tomé‐Açu,Eastern Amazon

The objective of this study was to verify the origin of and resulting floristic composition from seedbanks in different agroforestry systems in Tomé‐Açu, Brazil. The seedbanks were sampled in three smallholder farmers (Demonstration Units = DU), each with three agroforestry treatments and secondary forest as control. Seedling emergence in a glasshouse was used to quantify and identify the seeds collected in 2008. The floristic composition of the above‐ground community was characterised with annual floristic surveys from 2008 to 2011. The total densities and diversity of the seedbanks were not different among the treatments within a given DU, but differences occurred among DU. The most abundant woody species had higher seed densities in the secondary forests than in DU. Conversely, among the herbaceous species, two groups were differentiated: species with similar densities between the DU and the secondary forest and species with higher density in the DU. In the DU, the similarity between the floristic composition of the seedbank and the flora surveyed in 2008 was high, but decreased in subsequent years. The species present in the seedbank of agroforestry systems are highly influenced by the secondary forest, but provide little information about the floristic composition that will arise in the future.     

Is sewage sludge biochar capable of replacing inorganic fertilizers for corn production? Evidence from a two-year field experiment

Sewage sludge (SS) is a by-product of wastewater treatment resulting from human and industrial activities. This waste is problematic because it is difficult to manage due to its volume and environmental impacts; therefore, new technologies for treatment are needed to make its final disposal feasible. Such technologies include the pyrolysis process that produces biochar, which can be used for agricultural purposes. The present study reports a two-year field experiment with SS biochar produced under different pyrolysis temperatures and its application to soil in combination with mineral fertilizer to evaluate its effect on soil chemical properties and on corn nutrition and yield. To conduct this evaluation, 15 Mg ha^?1 of SS biochar combined or not with mineral fertilizer (NPK) was applied to the soil in the 2015 and 2016 cropping seasons. SS biochar increased soil chemical attributes, especially phosphorus, magnesium, cation exchange capacity and base saturation. Biochar resulted in a greater absorption of nutrients by plants and higher corn yields. However, SS biochar alone was incapable of increasing K uptake by corn. It was concluded that the application of SS biochar can replace mineral fertilizers (nitrogen, phosphorus and micronutrients) for corn production.     

Experimental Corynebacterium pseudotuberculosis primary infection in goats: kinetics of IgG and interferon-gamma production, IgG avidity and antigen recognition by Western blotting

Corynebacterium pseudotuberculosis is the cause of caseous lymphadenitis (CLA) in small ruminants, a chronic granulomatous disease that provokes significant zootechnics losses to ovine and goat breeders in northern Brazil. The present work was conducted to analyse aspects of humoral and cellular immune responses after experimental infection. Eight goats were infected intradermally with a single dose of virulent C. pseudotuberculosis strain and specific IgG, interferon-gamma (IFN-gamma) production as well as IgG avidity and antigens pattern recognition dynamics against an excreted-secreted antigen were recorded during 20 weeks. At the end of the follow-up, animals were slaughtered and necropsied. Although no animals showed apparent clinical signs of infection at the end of the trial, IFN-gamma response, even more so than the humoral response, differentiated animals into two groups of high or medium/low response. The time-course of IFN-gamma production presented a short-lived primary response on day 5 after infection of animals of both groups, and a strong and long lasting secondary response starting on day 16 after infection in the high response group. The indirect ELISA used was able to detect a positive antibody titre between 6 and 11 days after infection in the two groups. IgG avidity index oscillated initially between 15 and 45%, and showed approximately 5% units increment during the 20 follow-up weeks. With only one individual exception, the qualitative antigens pattern recognition showed on day 11 after infection remained constant through the experiment. IgG avidity is highly correlated with IgG production, but could not be related with specific immunodominant bands. Both humoral and cellular responses kinetics presented a similar pattern of activation/deactivation but necropsy results suggested that the IFN-gamma test would be a very specific marker of CLA status.     

Spontaneous emission spectrum in double quantum dot devices

A double quantum dot device is a tunable two-level system for electronic energy states. A dc electron current was used to directly measure the rates for elastic and inelastic transitions between the two levels. For inelastic transitions, energy is exchanged with bosonic degrees of freedom in the environment. The inelastic transition rates are well described by the Einstein coefficients, relating absorption with stimulated and spontaneous emission. The most effectively coupled bosons in the specific environment of the semiconductor device used here were acoustic phonons. The experiments demonstrate the importance of vacuum fluctuations in the environment for quantum dot devices and potential design constraints for their use for preparing long-lived quantum states.     

Hypothalamic polypeptide that inhibits the secretion of immunoreactive pituitary growth hormone

A peptide has been isolated from ovine hypothalamus which, at 1 x 10(-9)M, inhibits secretion in vitro of immunoreactive rat or human growth hormones and is similarly active in vivo in rats. Its structure is H-Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Cys-OH The synthetic replicate is biologically active.