Influence of different meal sizes on growth characteristics of young rainbow trout (Oncorhynchus mykiss Wal).

This paper presents the results of the effects of different sizes of meals (80%, 90%, 100%, 110% and 120% regarding the amount recommended by the food producer) on the growth characteristics of young rainbow trout (Oncorhynchus mykiss Wal.) aged from 2 to 3.5 months. The experiment was carried out at the Laboratory of Aquaculture, Faculty of Agriculture, University of Banja Luka for a period of 47 days. In the experiment, there were a total of 500 fish, divided into five groups, and placed in the 55-l aquarium with a constant flow of water and the aeration system. The main parameters of water quality were analyzed every day and they included: water temperature 12.64-12.76°C, content of dissolved oxygen 7.83-8.09 mg/l, saturation of water with oxygen 75.47-77.39% and pH value 7.224-7.268. In the end, the average individual weight and body length (±standard deviation) of young rainbow trout, regarding the experimental groups (EG), were reached: EG80 10.53±2.58 g and 9.94±0.76 cm, EG90 12.14±2.97 g and 10.45±0.86 cm, EG100 13.18±2.91 g and 10.67±0.82 cm, EG110 13.80±3.14 g and 10.82±0.78 cm, EG120 14.58±3.63 g and 10.81±1.11 cm. Statistically highly significant differences were found between the means of experimental groups (p <0,01). The coefficient of condition of young rainbow trout at the end of the experiment was similar in the treatments EG80, EG90, EG100 and EG110 (1.06 to 1.09), and it was the highest in the treatment EG120 (1,15±0,17). Generally, it can be said that increasing of the size of meals up to 10% above the recommended value does not cause significant differences, and if the increase is greater than 10%, statistically significant difference in body weight occurs

Dynamics of generating transients of delayed fluorescence induction signal and photosynthetic antennas: A possible relationship: Mathematical modeling approach

A mathematical model was developed for resolved temporal transients of experimentally recorded delayed fluorescence (DF) induction signal. During an intermittent light regime, antennas of the photosynthetic apparatus were treated as targets, repeatedly hit by potentially absorbable photons within a series of consecutive light flashes. Formulas were derived for the number of antennas, cumulatively hit by a specific number of photons, as function of the flash serial number (time). Model parameters included: number of absorbable photons in one flash, antenna sizes and numbers. A series of induction curves were analyzed, obtained from a ZeamaysL. leaf segment and differing in the previous dark period (td). Each curve, consisting of the two most prominent DF transients (C and D), was fitted with several model types, differing in the number of absorbed photons. For both transients, the best fitting result was achieved when DF induction was linked to the second absorbed photon. As expected, model parameters related to antenna sizes showed weaker dependence on td than those referring to antenna numbers. With restrictions applied in this model, the two DF induction transients may be related to two classes of photosynthetic antennas. Their different sizes may have a predominant influence on the efficiency of photon absorption, and possibly time-dependent appearance of DF transients

Polymorphism of Pramenka sheep hemoglobin in Central Bosnia

The study of the hemoglobin polymorphism was performed on blood samples, taken from areas inhabited by Pramenka sheep in Central Bosnia: the area of the mountain Vlašić, the upper flow of the river Vrbas and Kupres plateau. Dupska pramenka sheep inhabits the mountain Vlašić and the areas of surrounding municipalities. Privorska pramenka sheep inhabits the area around the upper flow of the river Vrbas and the mountain Vranica and Kupreška pramenka sheep inhabits Kupres plateau. HbA gene frequency was 0.31 and HbB gene frequency was 0.69 for Dupska pramenka sheep. Privorska pramenka sheep had a frequency of 0.33 for the HbA gene, and 0.67 for the HbB gene, in its population. Kupreška pramenka sheep had the lowest frequency of the HbA gene, (0.30), and therefore the maximum frequency of the HbB gene. Hemoglobin genotype frequencies for all investigated types of Pramenka sheep breed are in equilibrium. Investigated types of Pramenka sheep breed inhabit areas adjacent to each other. They are phenotypically quite similar and have a similar frequency of genotype polymorphism of hemoglobin. The difference between them is not statistically significant

Genetic divergence estimated by RAPD markers and its relationship with hybrid performance in popcorn

The objective of this study was to evaluate the genetic diversity of six popcorn inbred lines and to determine the relationship between combing ability and heterosis for grain yield and popping expansion and genetic distance, using random amplified polymorphic DNA (RAPD) molecular markers. The genetic distance based on Dice coefficient ranged from 0.086 to 0.212. The highest genetic distance was found between inbreds ZPL2 and ZPL5. Hybrid combination of these two inbreds has the highest grain yield, grain yield heterosis and popping expansion heterosis. A positive and significant correlation was observed in parental lines between grain yield and SCA with genetic distance based on RAPD markers. The genetic divergence, however, was not enough to determine the grain yield heterosis as well as heterosis and specific combining ability for popping expansion

E. coli Nissle 1917 is a safe mucosal delivery vector for a birch-grass pollen chimera to prevent allergic poly-sensitization

International audienceAllergic poly-sensitization affects a large number of allergic patients and poses a great challenge for their treatment. In this study we evaluated the effects of the probiotic Escherichia coli Nissle 1917 (EcN) expressing a birch and grass pollen allergen chimera ‘Bet v 1, Phl p 1 and Phl p 5’ (EcN-Chim) on allergy prevention after oral or intranasal application in poly-sensitized mice. In contrast to oral application, intranasal pretreatment with EcN-Chim prior to poly-sensitization led to a significant reduction of lung inflammation (eosinophils, IL-5, and IL-13 in bronchoalveolar lavage) along with suppressed levels of allergen-specific serum IgE. The suppression was associated with increased levels of allergen-specific IgA in lungs and serum IgG2a along with increased Foxp3, TGF-β, and IL-10 mRNA in bronchial lymph nodes. In vitro EcN induced high levels of IL-10 and IL-6 in both lung and intestinal epithelial cells. Importantly, using in vivo imaging techniques we demonstrated that intranasally applied EcN do not permanently colonize nose, lung, and gut and this strain might therefore be a safe delivery vector against allergy in humans. In conclusion, our data show that intranasal application of recombinant EcN expressing a multiallergen chimera presents a novel and promising treatment strategy for prevention of allergic poly-sensitization

Correction: E. coli Nissle 1917 is a safe mucosal delivery vector for a birch-grass pollen chimera to prevent allergic poly-sensitization

International audienc

Sixty years of ZP maize hybrid breeding

The modern ZP maize hybrids breeding at the Maize Research Institute, Zemun Polje, begun during the fifties of the 20(th) century. Collecting of the initial material was the first step in conducting maize breeding programs. The maize inbred line-developing programs from three local populations has initiated in 1953. That was beginning of breeding first cycles ZP maize hybrids. From that period up to present time, we have had five generations of ZP maize hybrids. Each generation has characterized by introduction of the new potentially higher yielding hybrids and with better other agronomics characteristics. According to results from different studies, the genetic yield potential of ZP maize hybrids over the last 40 years amounted to 100 kg.ha(-1) per year. ZP 755 was the first registered maize hybrid in the country in 1964. Total 499 ZP maize hybrids have released by the State Government Commission's since 1964 and 99 ZP maize hybrids have registered in 15 countries. Since the seventies biotechnology methods have been applied in the breeding programs. The main part of biotechnology work is based on the molecular marker application for determining genetic diversity, QTL mapping for drought tolerance and identification of chromosome regions harbouring QTLs for economically important traits (yield, kernel oil content)