44 research outputs found

    Genetic evaluation and selection correlated response of growth traits in Japanese quail

    Get PDF
    Objectives of the current study were to i) investigate effects of selection for bodyweight at four weeks old on bodyweight (BW) and bodyweight gain (BWG) across four generations; ii) estimate correlated response to selection for BW and BWG at different ages; and iii) document best linear unbiased prediction (BLUP) of genetic trends for BW and BWG across four generations of selection. A total of 3540 chicks from 444 sires and 885 dams were used to estimate heritabilities, and genetic and phenotypic correlations for growth traits, including BW at 0, 2, 4, and 6 weeks, and BWG between 0 and 2, 2 and 4, 4 and 6, and 0 and 6 weeks. The selection effects, correlated responses and genetic trend for BW and BWG across generations were quantified by applying the animal model. Estimates of heritability for BW and BWG ranged from 0.22 to 0.42 and from 0.18 to 0.23, respectively. Ranges of genetic and phenotypic correlations for BW varied from 0.31 to 0.92 and 0.05 to 0.65, respectively. Moreover, estimates of genetic and phenotypic correlations for BWG at different ages were from 0.12 to 0.72 and 0.17 to 0.60, respectively. Bodyweight and BWG estimates after four generations of selection were significantly higher than those of the base generation. Moreover, contrasts of generation means were significant across the four generations. The genetic trends across the generations clarified that BLUP estimates for BW and BWG gradually increased with the advance of generations until the fourth generation. Keywords: best linear unbiased prediction, bodyweight, heritability, selection, genetic tren

    Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, hematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus

    Get PDF
    A 12-week feeding trial was conducted to evaluate the effect of different ratios of fish meal (FM): cotton seed meal (CSM) without or with inclusion of exogenous protease in diets on growth performance, hematology, digestibility and selected gene expression markers (GH and I (IGF-I) of juvenile Nile tilapia. The experimental diets were categorized into three groups; the first group CSM1 which contained fish meal protein: cotton seed meal protein (FM: CSM = 2:1), the second group CSM2 which contained FM: CSM = 1:1 and the third one CSM3 contained FM: CSM = 1:2 on protein content based. All groups were supplemented with exogenous protease at 0 and 2500 U kg−1 diet, respectively. All diets were fed to fish (initial body weight 11.62 ± 0.03 g fish−1) in triplicate aquaria twice daily. The higher weight gain (WG), protein efficiency ratio (PER) and best feed conversion ratio (FCR) were recorded by fish fed CSM1 and CSM2 and supplemented with 2500 U protease/kg diet. The highest apparent digestibility coefficient of crude protein, crude lipid and digestible energy, and apparent availability coefficient of essential amino acids were obtained by fish receiving CSM1 and CSM2 supplemented with protease (2500 U protease kg−1 diet). The highest mean values of Hb, Htc and RBCs were recorded in fish fed CSM1 and CSM2 supplemented with protease enzyme (2500 U protease kg−1 diet). Serum of alanine and aspartate aminotransferase activities were improved due to dietary protease (2500 U protease kg−1 diet) supplementation, also, fish received the diets supplemented with protease 2500 U kg−1 diet generally had higher total protein, albumin, calcium and phosphorus than those fed diets without supplement. The highest growth hormone (GH) gene expression in brain and liver of tilapia were obtained in the group fed CSM3 and un-supplemented with protease enzyme followed by CSM2 (un-supplemented). On the other hand, tilapia fed CSM1 and CSM2 supplemented with protease enzyme showed the highest values of gene expression of insulin like growth factor I (IGF-I) in brain and liver of tilapia compared to other groups. Results above showed that supplementation of protease can improve growth, nutrient assimilation, and hematology and alter gene expression of GH and IGF-I of Nile tilapia

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Influence of Precursor Compounds on the Structural and Catalytic Properties of Cobalt-Based Catalysts

    No full text
    The effects of different cobalt precursor compounds on the structural and catalytic properties of cobalt metal and Co 3 O 4 catalysts have been investigated. The techniques employed for characterizing the different solids were XRD, ESR and TEM methods, together with their effectiveness as catalysts in the decomposition of H 2 O 2 at 30–50 °C. The results obtained indicate that the investigated catalysts contained clusters or very small particles of cobalt metal or Co 3 O 4 phases. Cobalt metal and Co 3 O 4 catalysts based on cobalt chloride exhibited higher catalytic activities than other catalysts derived from cobalt nitrate and sulphate salts, respectively, due to their decreased particle sizes. The activation energies of the catalytic reaction over the as-prepared catalysts revealed that the different precursor compounds did not modify the energetic nature of the active sites involved in the catalyzed reaction but changed their concentrations

    Procalcitonin as a diagnostic marker in acute exacerbation of COPD

    Get PDF
    Background: Rational prescription of antibiotics in acute exacerbations of COPD (AECOPD) requires predictive markers. Acute phase reactants are capable of demonstrating the inflammation; however, they cannot be employed to make a difference between bacterial and nonbacterial causes of the inflammation. Recently, measurement of procalcitonin (PCT) levels appears to be useful in order to minimize this problem. We aimed to evaluate the diagnostic and prognostic role of procalcitonin in (AECOPD). Patients and methods: A total of 50 patients with AECOPD and 10 of apparently healthy individuals (control group) were studied. On presentation, serum PCT concentrations were measured, and quantitative sputum culture was performed for AECOPD. The patients were reevaluated when they had returned to their stable clinical state. Pathogenic bacterial microorganism (PBM) was only regarded as significant if they reached a growth 105 CFU/ml, indicating the presence of bacterial exacerbation of COPD. The patients were classified into two subgroups: group A included patients with bacterial AECOPD (n = 20), group B included patients with nonbacterial AECOPD (n = 30). Results: On presentation, the levels of PCT for patients of group A (2.69 ± 0.62 ng/mL) were significantly higher than group B (0.07 ± 0.02 ng/mL) and control group (0.05 ± 0.02 ng/mL) (p  0.05). In the stable state, there were no differences in the PCT measurement between the two subgroups as well as between patients and control. Furthermore, a significant correlation was recorded between PCT levels in group A at time of presentation and temperature (r = 0.898, p < 0.05), leucocytic count (r = 0.889, p < 0.05), FEV1% of predicted (r = 0.898,p < 0.05), ESR (r = 0.899, p < 0.05), CRP (r = 0.895, p < 0.05) and duration of hospital stay (r = 0.897, p < 0.05). Conclusions: Procalcitonin is a good marker for differentiation between bacterial and nonbacterial AECOPD and could be used to guide antibiotic therapy and reduce antibiotic overuse in hospitalized patients with AECOPD

    Helminth parasites of fishes from two inland lakes in Egypt

    No full text
    Results of helminthological examination of 1243 fishes, caught from two inland lakes, with unique and contrasting hydrobiological features at Fayoum Governate in Egypt, are presented. General incidence of trematodes, cestodes, nematodes and acanthocephalans in fishes from the two lakes are compared. Eleven genera of digentic trematodes are reported for the first time in certain fishes of the two lakes. The incidence of single, simultaneous double or multiple infections with digentic trematodes in fishes of the two lakes are compared. The respective relationships of digentic trematode fauna of fishes from the two lakes with those from the River Nile and the Mediterranean Sea are suggested

    How do Mentha plants induce resistance against Tetranychus urticae (Acari: Tetranychidae) in organic farming?

    No full text
    Tetranychus urticae (Acari: Tetranychidae) infesting many plants but Mentha viridis L., and Mentha piperita L., were low in number of infestation. Therefore the objective of this study was to identify the resistance of M. viridis and M. piperita plants against T. urticae by studying the external shape and internal contents of those plants. For morphological studies, dried leaves were covered with gold utilizing an Edwards Scan coat six sputter-coater. For histological studies, arrangements of Soft Tissue technique were used. For phytochemical studies, the plants were cut, dried and then high performance liquid chromatography (HPLC) was used. While feeding the mites were collected from the area between oily glands, trichomes and respiratory stomata in both mint species. The most important leaf structures in aromatic plants are the oily glands found on the external part of the leaves (both upper and lower epidermis). The number of oil glands in M. viridis leaves was greater than in M. piperita; the trichomes on the epidermis of M. viridis were greater in number than in M. piperita; the spongy mesophyll in M. viridis was much thicker than in M. piperita. The essential oils in the leaves of both mint species contained 71 compounds representing 99.61% of the total oil constituents identified from M. viridis before infestation, and 90.95% after infestation, and about 99.65% from M. piperita before infestation, and 99.98% after infestation

    Chickpea (Cicer arietinum) steep liquor as a leavening agent: Effect on dough rheology and sensory properties of bread

    No full text
    Dough fermentation is one of the oldest process in food technologies. It has been recently intensively studied for its impact on the sensory, structural, nutritional and shelf life properties of leavened baked products. The goals of this work were to investigate chickpea steep liquor (CSL) as a dough-leavening agent and to study the effect of CSL on the dough rheology and sensory properties of leavened bread. CSL was prepared by submerging chickpea seeds in boiled distilled water (1:2, w/v) for 24 h at 37оC, and then obtained liquor was filtered and freeze-dried to obtain CSL. The addition of CSL to wheat flour (WF) brought changes in the dough mixing behavior as measured by the farinograph. An increase in the farinograph water absorption of WF dough was observed when 4.5% CSL and 1.5% yeast was added, while arrival time was not affected. Addition of CSL to the dough at a content of 4.5, 9.0 and 13.5 g CSL/300 g WF caused an increase in dough stability. The CSL addition also increased mechanical tolerance index, dough weakening and mixing time. Dough development time for all blends was higher than the control (1.2-1.5 min), while between the CSL samples no significant difference was observed. The loaf weight slightly increased from 146.2 g for control to 152.2 g for CSL fermented bread, whereas the loaf volume and specific volume of CSL-fermented bread were lower than the control. The combination of yeast and CSL increased the acceptability of bread with the increasing level of both leavening agents’. The results show that CSL could be used as an alternative to yeast for syngas fermentation. On the other hand, CLS is rich in nutrients and lower in cost compared to yeast
    corecore