Carcass and meat quality of finished and non-finished Limousin heifers from alpine livestock systems differing in altitudinal origin of the forage

Effects of the alpine origin of the forage and of finishing on carcass and beef quality were quantified by modelling different alpine livestock system alternatives. Thirty-five Limousin heifers, initially weighing 383 ± 45 kg, were fed fresh grass at 400 or 2000 m above sea level, or a 1:1 mixture of alpine grass and lowland grass hay at 2000 m. After 9 weeks, the six heaviest and oldest animals per group were slaughtered. The remaining animals were finished for 8 weeks on a silage-concentrate diet in the lowlands to similar age and body weight as the first slaughtered group. Carcass and meat quality (M. longissimus thoracis) were assessed in various respects. The average daily gains achieved were of about 600 g/d and similar between forage-type groups. Dressing percentage was 53.5% in the alpine and 57.2% in the lowland group. Carcass conformation and fat cover scores did not differ between forage-type groups. The meat from the alpine groups had greater ultimate pH and smaller redness, yellowness and protein contents. Still, these differences were of minor practical relevance. There was no forage-type effect on water-holding capacity and shear force of the meat. The alpine systems enhanced the proportion of α-linolenic acid in intramuscular fat and decreased the levels of some volatile compounds in perirenal fat. Finishing resulted in compensatory growth, especially in the animals previously fed lowland grass. There was a trend for the finished compared with the non-finished groups towards greater carcass fat cover and intramuscular fat content. Additionally, ultimate pH was smaller and cooking loss was greater with than without finishing. Meat colour differences were also observed. Shear force was not affected by finishing. The finished animals had a smaller α-linolenic acid proportion in the intramuscular fat. In conclusion, the forage type had small effects on carcass and meat quality. Finishing did not substantially improve carcass and meat quality. The (alpine) grass-specific differences in fatty acid profile found in the unfinished cattle were not present in the finished animals.     

Ultrastructure comparée de la spermiogenèse et du spermatozoïde de trois espèces de Paravortex (Rhabdocoela, "Dalyellioida", Graffillidae), Turbellariés parasites intestinaux de Mollusques

Three species of the genus Paravortex were studied. Spermiogenesis involves progressive lengthening of the spermatid. No centriole nor axoneme were found. Thc mature spermatozoon is threadlike, 30μm long and aflagellate. It contains a nucleus, two longitudinal parallel mitochondria, numerous dense bodies limited by a membrane, a row of cortical microtubules and granules. The spatial arrangement of the microtubules wah deduced from a statistical analysis of their number in transverse section. The microtubules are continuous along the length of the spermatozoon and are arranged along a long cone. The granules, not limited by a membrane, are about 25 nm in diameter. They are arranged in a semicircle and represent a new structure for sperm of Platyhclminthes. A statistical comparison demonstrated that two species may be distinguished by the number of their cortical sperm microtubules. This is the tirst ultrastructural study of an aflagellate spermatozoon in the Rhabdocoela. A rickettsia was found in P. cardii .     

Genetic characterisation of the intermediate hosts of schistosomiasis in its southern distribution limit in South America

ABSTRACT

Schistosomiasis is a tropical disease caused by the digenean parasite Schistosoma mansoni. In South America it is transmitted to humans via freshwater snails of the genus Biomphalaria. In a global warming scenario, disease range expansions to subtropical countries are possible. For the first time, the distributions and genetic identification of Biomphalaria specimens in border regions of Uruguay are reported. The inclusion of Uruguayan samples allows a better understanding of the relationships between and within taxa of Biomphalaria. Samples were collected between 2015 and 2016 using hand nets. Initially, they were classified morphologically. They were then classified genetically by analysing a fragment of the cytochrome c oxidase subunit I gene. Phylogenetic analysis revealed the presence of B. peregrina and B. occidentalis. Species belonging to the B. tenagophila complex were also recognised. Individuals initially identified from their external morphology as B. tenagophila tenagophila showed inconsistencies with the analysis of COI sequences that assigned them to B. occidentalis. Since the presence of schistosomiasis in Uruguay is likely to occur in the next few years, an exhaustive population survey of Biomphalaria taxa should be urgently developed to identify the presence of S. mansoni and the places most susceptible to be colonised by these snails.     

An ecophysiologically based mapping model identifies a major pleiotropic QTL for leaf growth trajectories of Phaseolus vulgaris

Crop modeling, a widely used tool to predict plant growth and development in heterogeneous environments, has been increasingly integrated with genetic information to improve its predictability. This integration can also shed light on the mechanistic path that connects the genotype to a particular phenotype under specific environments. We implemented a bivariate statistical procedure to map and identify quantitative trait loci (QTLs) that can predict the form of plant growth by estimating cultivar‐specific growth parameters and incorporating these parameters into a mapping framework. The procedure enables the characterization of how QTLs act differently in response to developmental and environmental cues. We used this procedure to map growth parameters of leaf area and mass in a mapping population of the common bean (Phaseolus vulgaris L.). Different sets of QTLs are responsible for various aspects of growth, including the initiation time of growth, growth rate, inflection point and asymptotic growth. A major QTL of a large effect was identified to pleiotropically affect trait expression in distinct environments and different traits expressed on the same organism. The integration of crop models and QTL mapping through our statistical procedure provides a powerful means of building a more precise predictive model of genotype‐phenotype relationships for crops.     

Is nitrogen accumulation in grain legumes responsive to growth or ontogeny?

Nitrogen (N) accumulation in legumes is one of the main determinants of crop yield. Although N accumulation from symbiotic nitrogen fixation or N absorption from the soil has been widely investigated, there is no clear consensus on timing of the beginning of N accumulation and the termination of N accumulation and the physiological events that may be associated with these two events. The analyses conducted in this study aimed at identifying the determinant of N accumulation in two grain legume species. Nitrogen accumulation dynamics and mass accumulation and development stages were recorded in the field for several genotypes of common bean (Phaseolus vulgaris) and faba bean (Vicia faba) under different growing conditions. This study showed that during the vegetative stages, N accumulation rate was correlated with mass accumulation rate. However, the maximum accumulation of N did not correspond to the time of the maximum mass accumulation. In fact, for both species, N accumulation was found to persist in seed growth. This challenges a common hypothesis that seed growth causes a decrease in N accumulation because of a shift of the photosynthate supply to support the seed growth. Even more surprising was the shift of the active accumulation of N in faba bean to late in the growing season as compared with common bean. N accumulation by faba bean only was initiated at high rates very late in vegetative growth and persisted at high rates well into seed fill.     

T cell epitopes of the circumsporozoite protein of Plasmodium vivax. Recognition by lymphocytes of a sporozoite-immunized chimpanzee.

The humoral and cellular antisporozoite immune responses of a laboratory-born chimpanzee were measured following multiple exposures to the bites of Plasmodium vivax-infected mosquitoes. T cell lines and clones derived from the chimpanzee's PBL were used to identify T cell epitopes of the P. vivax circumsporozoite (CS) protein. Two independently obtained cell lines, established by culturing the PBL with either a recombinant P. vivax circumsporozoite (rPvCS) protein or a pool of synthetic peptides spanning the rPvCS sequence, recognized a 20-mer peptide from a nonpolymorphic region of the carboxyl terminus of the CS protein. This peptide overlaps a sequence homologous to region II of the Plasmodium falciparum CS protein. A third T cell line recognized an epitope within the central repeat domain, which has recently been found to be a polymorphic region of the P. vivax CS protein. The CD4+ clones derived from this third T cell line secreted IFN-gamma and IL-2 when stimulated with either the P. vivax repeat peptide (DRAAGQPAG)2 or the rPvCS protein.     

Fecal Bacterial Community Changes Associated with Isoflavone Metabolites in Postmenopausal Women after Soy Bar Consumption

Soy isoflavones and their metabolism by intestinal microbiota have gained attention because of potential health benefits, such as the alleviation of estrogen/hormone-related conditions in postmenopausal women, associated with some of these compounds. However, overall changes in gut bacterial community structure and composition in response to addition of soy isoflavones to diets and their association with excreted isoflavone metabolites in postmenopausal women has not been studied. The aim of this study was to determine fecal bacterial community changes in 17 postmenopausal women after a week of diet supplementation with soy bars containing isoflavones, and to determine correlations between microbial community changes and excreted isoflavone metabolites. Using DGGE profiles of PCR amplified 16S rRNA genes (V3 region) to compare microbial communities in fecal samples collected one week before and one week during soy supplementation revealed significant differences (ANOSIM p<0.03) before and after soy supplementation in all subjects. However, between subjects comparisons showed high inter-individual variation that resulted in clustering of profiles by subjects. Urinary excretion of isoflavone (daidzein) metabolites indicated four subjects were equol producers and all subjects produced O-desmethylangolensin (ODMA). Comparison of relative proportions of 16S rRNA genes from 454 pyrosequencing of the last fecal samples of each treatment session revealed significant increases in average proportions of Bifidobacterium after soy consumption, and Bifidobacterium and Eubacterium were significantly greater in equol vs non-S-(-)equol producers. This is the first in vivo study using pyrosequencing to characterize significant differences in fecal community structure and composition in postmenopausal women after a week of soy diet-supplementation, and relate these changes to differences in soy isoflavones and isoflavone metabolites.

Trial Registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00244907","term_id":"NCT00244907"}}NCT00244907