112 research outputs found
Chromosome identification in the Andean common bean accession G19833 (Phaseolus vulgaris L., Fabaceae)
Characterization of all chromosomes of the Andean G19833 bean genotype was carried out by fluorescent in situ hybridization. Eleven single-copy genomic sequences, one for each chromosome, two BACs containing subtelomeric and pericentromeric repeats and the 5S and 45S ribosomal DNA (rDNA) were used as probes. Comparison to the Mesoamerican accession BAT93 showed little divergence, except for additional 45S rDNA sites in four chromosome pairs. Altogether, the results indicated a relative karyotypic stability during the evolution of the Andean and Mesoamerican gene pools of P. vulgaris
Economically sustainable shade design for feedlot cattle
Provision of shade reduces radiant heat load on feedlot cattle, thus reducing demand of water and energy for thermoregulation. While the positive effects of shade on animal welfare are widely known, the literature lacks data on the magnitude of its economic impacts. In this study, we propose the concept of novel shade design to prove that a correctly oriented and dimensioned roof structure, which optimizes shade to be displaced within the pens, motivates cattle to seek shade, protect them from short-wave solar radiation, and is resilient to counteract weather adverse conditions. The beneficial outcome is improvement in animal welfare and productive performance, as well as increments on financial return and sustainability. To attest these benefits, eight hundred B. indicus Ă Bos taurus bulls were randomly assigned in pens with or without shade from a galvanized steel-roof structure. Performance data (e.g., dry matter intake, body weight gain, feed efficiency and hot carcass weight) and heat stress indicators (e.g., subcutaneous temperature, body-surface temperature, respiratory rate and water intake) were assessed along the study period. The economic outcomes derived from shade implementation were determined using the net present value. Meteorological variables were also monitored every 1 min, and grouped in a thermal comfort index for feedlot cattle, the InComfort Index (InCI). The shade structure efficiently reduced radiant heat load on cattle in pens with shade. According to the classification of the InCI, during very hot days (InCI > 0.6; around noon with mean solar radiation above 800 W mâ2 and mean air temperature above 33°C), greater proportion (80%) of animals in shaded pens were using shade. Under such circumstances, cattle in shade had water intake reduced by 3.4 L per animal, body temperature was lower by 5°C, subcutaneous temperature was lower by 1°C and respiration rate was lower by 10 breaths minâ1 compared to animals in pens without shade (P = 0.0001). Although dry matter intake was similar (P = 0.6805), cattle in pens with shade had higher average daily gain reflected in a heavier hot carcass weight (8 kg animalâ1; P = 0.0002). Considering an initial investment of $90 per animal to build a structure that lasts 15 years, the expected payback time is four finishing cycles (~110 days per cycle). In conclusion, this study confirms that the proposed novel shade design is economically profitable, improves performance, and enhances animal welfare
Callus induction and bioactive phenolic compounds production from Byrsonima verbascifolia (L.) DC. (Malpighiaceae)
ABSTRACT -This study developed a methodology for callus induction in leaf segments of B. verbascifolia and evaluated the bioactive phenolic compounds production. Leaf explants were cultured in MS medium with 30 g L -1 sucrose, solidified with 7 g L -1 agar supplemented with 2,4-D (0; 4.52; 9.05; 18.10 M) and BAP (0; 4.44; 8.88; 17.75 M ) in the presence and absence of light. Forty-five days after inoculation we assessed the percentage of callus induction, color, consistency, fresh and dry matter, total phenols, flavonoids, tannins contents, and chromatographic profile by HPLC-DAD method. Callus induction occurred only in medium with growth regulators. Maximal induction (100%) was found in medium containing 2,4-D combined with BAP in the presence and absence of light. We obtained friable and compact callus in yellow, green, and red. Culture media containing 4.52 M 2,4-D + 4.44 M BAP induced 100% of friable callus with higher fresh and dry weight in the absence of light. The callus produced higher amounts of total phenols and flavonoids than the initial explant
Structure-based functional inference of hypothetical proteins from Mycoplasma hyopneumoniae
Enzootic pneumonia caused by Mycoplasma hyopneumoniae is a major constraint to efficient pork production throughout the world. This pathogen has a small genome with 716 coding sequences, of which 418 are homologous to proteins with known functions. However, almost 42% of the 716 coding sequences are annotated as hypothetical proteins. Alternative methodologies such as threading and comparative modeling can be used to predict structures and functions of such hypothetical proteins. Often, these alternative methods can answer questions about the properties of a model system faster than experiments. In this study, we predicted the structures of seven proteins annotated as hypothetical in M. hyopneumoniae, using the structure-based approaches mentioned above. Three proteins were predicted to be involved in metabolic processes, two proteins in transcription and two proteins where no function could be assigned. However, the modeled structures of the last two proteins suggested experimental designs to identify their functions. Our findings are important in diminishing the gap between the lack of annotation of important metabolic pathways and the great number of hypothetical proteins in the M. hyopneumoniae genome
Successional trajectory of the fouling community on a tropical upwelling ecosystem in southeast Rio de Janeiro, Brazil
Abstract The present study describes the successional trajectory of the fouling community in the upwelling region of Cabo Frio in southeastern Rio de Janeiro, Brazil. For 12 months, five PVC panels were sampled monthly by underwater photography to record the percent cover of fouling organisms, which allowed for the evaluation of the successional process through functional groups. The variability in the composition of the fouling community increased throughout the successional trajectory, creating a mosaic pattern. The identification of two associations after a year of observation, with one characterized by filamentous algae, Hydrozoa and Cirripedia and another mainly by articulated calcareous algae, shows that divergent trajectories can be observed even under the same environmental conditions. As an important seasonal factor of the local oceanographic characteristics, the upwelling events allowed for an environmental heterogeneity, and rejecting the classic orderly and directional succession model
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