684 research outputs found
Further Studies on the Nutritive Value of Alcohol-Extracted Animal Tissues and the Supplements Required for Growth and Lactation
In order to reveal more clearly the nutritive value of beef heart, kidney, round, and liver, these tissues, after hot alcohol extraction, were incorporated at a 15 per cent protein level in a ration adequate in the recognized factors necessary for normal nutrition. A simultaneous study of the whole dried tissues, at the same level of protein intake, revealed that rats fed the whole tissue made better gains than those on the respective extracted tissues. In those groups receiving the extracted material the most rapid growth was on kidney, and the poorest on liver, while round and heart gave intermediate growth
Niche divergence facilitated by fine-scale ecological partitioning in a recent cichlid fish adaptive radiation
Ecomorphological differentiation is a key feature of adaptive radiations, with a general trend for specialization and niche expansion following divergence. Ecological opportunity afforded by invasion of a new habitat is thought to act as an ecological release, facilitating divergence, and speciation. Here, we investigate trophic adaptive morphology and ecology of an endemic clade of oreochromine cichlid fishes (Alcolapia) that radiated along a herbivorous trophic axis following colonization of an isolated lacustrine environment, and demonstrate phenotype-environment correlation. Ecological and morphological divergence of the Alcolapia species flock are examined in a phylogenomic context, to infer ecological niche occupation within the radiation. Species divergence is observed in both ecology and morphology, supporting the importance of ecological speciation within the radiation. Comparison with an outgroup taxon reveals large-scale ecomorphological divergence but shallow genomic differentiation within the Alcolapia adaptive radiation. Ancestral morphological reconstruction suggests lake colonization by a generalist oreochromine phenotype that diverged in Lake Natron to varied herbivorous morphologies akin to specialist herbivores in Lakes Tanganyika and Malawi
The Role of Liver in Growth, Reproduction and Lactation
Alcohol-extracted beef liver was fed to albino rats as the only source of protein in a ration adequate in the recognized factors necessary for normal nutrition, the vitamins being supplied by yeast, cod liver oil and hydrogenated cottonseed oil (Crisco) ; the latter furnished the fat of the basal diet. The ration was found to be inadequate for optimum growth, reproduction and lactation. Supplementing the basal diet with 0.5 g. of raw liver or replacing the extracted-liver of the basal diet with whole dried liver greatly increased the growth rate and improved lactation
Modelling the prevalence of Salmonella carrier pigs at slaughtering age: influence of management systems and of the Salmonella status of replacement gilts
To reduce Salmonella contamination of pork food cham at the farm level, control actions can aim at preventmg the introduction of the bactena into herds or/and at preventing the in-herd transmission. Our aim is to estimate the influence of (i) the decontamination efficiency and (ii) the Salmonella status of replacement gilts on the prevalence of carrier pigs at slaughtering age. We developed a stochastic mathematical model to simulate the pig population dynamics and the Salmonella transmiss1on withrn a farrow-to-finish herd. Results show a different prevalence of carnage in groups of delivered pigs according to the scenarios tested
Quantification of the Effects of Ketosis on Reproduction in Dairy Cows by Meta-Analysis
Contextualizing time-series data: quantification of short-term regional variability in the San Pedro Channel using high-resolution in situ glider data
Oceanic time series have been instrumental in providing an understanding of
biological, physical, and chemical dynamics in the oceans and how these
processes change over time. However, the extrapolation of these results to
larger oceanographic regions requires an understanding and characterization
of local versus regional drivers of variability. Here we use high-frequency
spatial and temporal glider data to quantify variability at the coastal San
Pedro Ocean Time-series (SPOT) site in the San Pedro Channel (SPC) and
provide insight into the underlying oceanographic dynamics for the site. The
dataset could be described by a combination of four water column profile
types that typified active upwelling, a surface bloom, warm-stratified
low-nutrient conditions, and a subsurface chlorophyll maximum. On weekly
timescales, the SPOT station was on average representative of 64 % of
profiles taken within the SPC. In general, shifts in water column profile
characteristics at SPOT were also observed across the entire channel. On
average, waters across the SPC were most similar to offshore profiles,
suggesting that SPOT time series data would be more impacted by regional
changes in circulation than local coastal events. These results indicate that
high-resolution in situ glider deployments can be used to quantify major
modes of variability and provide context for interpreting time series data,
allowing for broader application of these datasets and greater integration
into modeling efforts.</p
Control of bovine mastitis: old and recent therapeutic approaches
Mastitis is defined as the inflammatory response resulting of the infection of the udder tissue and it is reported in numerous species, namely in domestic dairy animals. This pathology is the most frequent disease of dairy cattle and can be potentially fatal. Mastitis is an economically important pathology associated with reduced milk production, changes in milk composition and quality, being considered one of the most costly to dairy industry. Therefore, the majority of research in the field has focused on control of bovine mastitis and many efforts are being made for the development of new and effective anti-mastitis drugs. Antibiotic treatment is an established component of mastitis control programs; however, the continuous search for new therapeutic alternatives, effective in the control and treatment of bovine mastitis, is urgent. This review will provide an overview of some conventional and emerging approaches in the management of bovine mastitis infections.F. Gomes acknowledge the financial support of the Portuguese Foundation for Science and Technology through the Grant SFRH/BPD/84488/2012 and for financial support to the CEB research center
Mapping Arginase Expression with <sup>18</sup>F-Fluorinated Late-Generation Arginase Inhibitors Derived from Quaternary α-Amino Acids
Arginase hydrolyzes L-arginine and influences levels of polyamines and nitric oxide. Arginase overexpression is associated with inflammation and tumorigenesis. Thus, radiolabeled arginase inhibitors may be suitable PET tracers for staging arginase-related pathophysiologies. We report the synthesis and evaluation of 2 radiolabeled arginase inhibitors, 18F-FMARS and 18F-FBMARS, developed from α-substituted-2-amino-6-boronohexanoic acid derivatives. Methods: Arylboronic ester-derived precursors were radiolabeled via copper-mediated fluorodeboronation. Binding assays using arginase-expressing PC3 and LNCaP cells were performed. Autoradiography of lung sections from a guinea pig model of asthma overexpressing arginase and dynamic small-animal PET imaging with PC3-xenografted mice evaluated the radiotracers' specific binding and pharmacokinetics. Results:18F-fluorinated compounds were obtained with radiochemical yields of up to 5% (decay-corrected) and an average molar activity of 53 GBq⋅μmol-1 Cell and lung section experiments indicated specific binding that was blocked up to 75% after pretreatment with arginase inhibitors. Small-animal PET studies indicated fast clearance of the radiotracers (7.3 ± 0.6 min), arginase-mediated uptake, and a selective tumor accumulation (SUV, 3.0 ± 0.7). Conclusion: The new 18F-fluorinated arginase inhibitors have the potential to map increased arginase expression related to inflammatory and tumorigenic processes. 18F-FBMARS showed the highest arginase-mediated uptake in PET imaging and a significant difference between uptake in control and arginase-inhibited PC3 xenografted mice. These results encourage further research to examine the suitability of 18F-FBMARS for selecting patients for treatments with arginase inhibitors
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