Detection of a novel chloramphenicol resistance plasmid from "equine" Staphylococcus sciuri

A small chloramphenicol resistance (Cm) plasmid of 4.65 kB could be detected in an "equine" Staphylococcus sciuri-culture. This plasmid, designated as pSC3, was identified by interspecific protoplast transformation. On the basis of restriction endonuclease analyses a detailed restriction map of pSC3 could be constructed. This allowed structural comparisons of pSC3 with Cm-plasmids of other staphylococcal species from infections of humans and animals and identification of pSC3 as a member of the pC 221-family of staphylococcal Cm-plasmids. The pSC3-plasmid encoded an inducible chloramphenicol acetyltransferase as confirmed by enzymatic assays. This enzyme could be demonstrated in cell-free lysates of Cm-induced pSC3-transformants.     

Plasmid-encoded antibiotic resistance in Staphylococcus hyicus

A total of 33 Staphylococcus hyicus-cultures from piglets with exudative epidermatitis were analyzed for the presence of antibiotic resistance plasmids. Four small plasmids encoding resistances to chloramphenicol, macrolide-lincosamide-antibiotics, streptomycin or tetracyclines could be identified in plasmid-curing and plasmid-transformation experiments. For further characterization these plasmids were digested with restriction endonucleases. This led to the construction of a specific restriction map for each of the 4 plasmids. On the basis of their restriction maps, these 4 antibiotic resistance plasmids from "porcine" S. hyicus-cultures were compared with the respective resistance plasmids of other staphylococcal species from infections of humans and animals.     

Is single-step genomic REML with the algorithm for proven and young more computationally efficient when less generations of data are present?

Efficient computing techniques allow the estimation of variance components for virtually any traditional dataset. When genomic information is available, variance components can be estimated using genomic REML (GREML). If only a portion of the animals have genotypes, single-step GREML (ssGREML) is the method of choice. The genomic relationship matrix (G) used in both cases is dense, limiting computations depending on the number of genotyped animals. The algorithm for proven and young (APY) can be used to create a sparse inverse of G (GAPY~-1) with close to linear memory and computing requirements. In ssGREML, the inverse of the realized relationship matrix (H⁻¹) also includes the inverse of the pedigree relationship matrix, which can be dense with a long pedigree, but sparser with short. The main purpose of this study was to investigate whether costs of ssGREML can be reduced using APY with truncated pedigree and phenotypes. We also investigated the impact of truncation on variance components estimation when different numbers of core animals are used in APY. Simulations included 150K animals from 10 generations, with selection. Phenotypes (h² = 0.3) were available for all animals in generations 1–9. A total of 30K animals in generations 8 and 9, and 15K validation animals in generation 10 were genotyped for 52,890 SNP. Average information REML and ssGREML with G⁻¹ and GAPY~-1 using 1K, 5K, 9K, and 14K core animals were compared. Variance components are impacted when the core group in APY represents the number of eigenvalues explaining a small fraction of the total variation in G. The most time-consuming operation was the inversion of G, with more than 50% of the total time. Next, numerical factorization consumed nearly 30% of the total computing time. On average, a 7% decrease in the computing time for ordering was observed by removing each generation of data. APY can be successfully applied to create the inverse of the genomic relationship matrix used in ssGREML for estimating variance components. To ensure reliable variance component estimation, it is important to use a core size that corresponds to the number of largest eigenvalues explaining around 98% of total variation in G. When APY is used, pedigrees can be truncated to increase the sparsity of H and slightly reduce computing time for ordering and symbolic factorization, with no impact on the estimates.     

Primary and secondary metabolite composition of kernels from three cultivars of Portuguese chestnut (Castanea sativa Mill.) at different stages of industrial transformation

Chestnut (Castanea sativa) is an important basic food in rural diets and a major starch crop used in a similar way to potatoes. Chestnuts are a fundamental economic resource in the "chestnut regions" not only for the fruit but also for the chestnut wood. Chestnuts have become increasingly important with respect to human health, for example, as an alternative gluten-free flour source. Chestnuts are also a rich source of other beneficial compounds, but there have been few studies on the composition during processing. In this study, we analyzed the chemical composition of three Portuguese cultivars at different stages of industrial processing. The chestnut cultivars were Longal, Judia, and Martaínha. All three cultivars had high moisture contents but were low in ash, crude fat, and crude protein contents, with high starch and low fiber contents. The free amino acid contents, including various essential amino acids, varied depending on the cultivar. All three cultivars also had a significant content of polyphenolics with gallic acid; ellagic acid was predominant among hydrolyzable and condensed tannins. Many of these compounds are known to exert significant positive effects on human health. The one-way analysis of variance for fresh chestnut shows significant differences among the three cultivars for most of the studied parameters. The same statistical analysis applied to each one of the two cultivars (Judia and Longal) sampled for the four processing steps analyzed indicates a significant effect of this factor in practically all of the constituents. On the other hand, the two-way analysis of variance shows that, besides the residual, the processing step and the interaction cultivar x processing step were the factors that more contributed for the total variation observed in the constituents analyzed, while the contribution of cultivar was much less significant.     

Aroma potential of two bairrada white grape varieties: Maria Gomes and Bical

Maria Gomes and Bical are the main white grape varieties in Portuguese Bairrada Appellation, which represent 80% and 15%, respectively, of white vineyard. To estimate their aroma potentialities, free and potential volatile components from the musts were examined. The free volatile components were extracted using a liquid-liquid continuous method and were analyzed by gas chromatography-mass spectrometry. The potential volatile compounds were determined after elimination of the free components by heat and enzymatic treatments. Principal component analysis was used to establish relations between the compounds and the varieties and also the form (free or in potential). Maria Gomes has 11.5 mg/L volatile compounds, of which 33% are in free form; Bical has 4.4 mg/L volatile compounds, of which 46% are in free form. A total of 59 compounds was identified and quantified. In Maria Gomes, the sum of the terpenoids is within the perception limits for hotrienol (0.21 mg/L) and linalool (0.20 mg/L). In Bical, benzyl alcohol and phenylethylethanol represent 20% of the volatile compounds. Considering that the volatile composition pattern of Maria Gomes and Bical varieties are different, wine-making technologies should be developed specifically for each variety.     

Computed Tomography of the Lungs of the Dog by a Six-generation CT Scanner, Intravenous Contrast Medium and Different Windows

Computed tomography (CT) is a modern technique of image diagnosis particularly recommended in human medicine to evaluate the existence of pulmonary pathological changes such as neoplasms, metastasis, interstitial infiltrates, etc. In veterinary medicine, however, few anatomical and clinical CT studies in the dog have used apparatus of the latest generation, including injection of intravenous contrast and application of regional specific CT windows with different window width (WW) and window level (WL) to evaluate the lungs, the pulmonary vessels and the bronchial structures. This methodology allows the obtaining of clear CT images with high capacity of tissue discrimination and different shades of attenuation. In this work we have planned a tomographic study of the lungs of the dog by using a six-generation spiral CT scanner (Toshiba Ex Vision), belonging to the private Medical Institute of Radiology 'Irion' of Porto Alegre, Brazil. Four mixed-breed mature dogs (4–6 years, 15–20 kg) were used, two males and two females. The dogs were anaesthetized and kept in a maximum inspiration when obtaining the images. Dogs were placed in a stretcher in a ventral or sternal recumbency. Previously, the contrast urografin® was injected in the cephalic vein. Different CT windows were applied in order to increase the quality of the images: pulmonary window (WW 928; WL -680), high-resolution pulmonary window (WW 1085; WL -750), and soft tissue window (WW 652; WL -34). The use of intravenous contrast, different CT windows and a modern CT apparatus produced excellent images of the pulmonary parenchyma, the pleural cavity, the pulmonary veins, the lobular rami of the pulmonary artery and the lobular bronchi.     

Protective effect of clenbuterol on duodenal epithelium during food restriction in rats

The aim of the study was to examine the effect of the beta2-adrenoceptor, clenbuterol, on the duodenal epithelium of food-restricted rats. Clenbuterol was administered as a dietary admixture (4 mg/kg diet) to three groups of male Wistar rats (n = 8) housed individually in metabolic cages and fed ad libitum for 15 days at 110% and 160% of the estimated requirement for energy maintenance. Untreated groups at each energy intake level were also included. Samples of the duodenum were examined by light microscopy. Compared with control animals, clenbuterol treatment significantly increased body mass in all diet groups, although it induced no changes in mean food intake. Gastrointestinal (GIT) dry mass was increased by clenbuterol only in the most severely-restricted-diet group. In this group, clenbuterol treatment increased GIT tissue nitrogen (23%), more than it did in the ad libitum group (13%). In all treated groups, clenbuterol induced significant hypertrophy of duodenal enterocytes and circular muscle layers, and the diameter of lymphatic vessels increased. In the clenbuterol-treated, restricted-diet groups the height of the brush borders of enterocytes increased. It is concluded that clenbuterol has a protective effect on the intestinal structure in rats on restricted as well as ad libitum diets.     

Learning by doing: a participatory methodology for systematization of experiments with agroforestry systems, with an example of its application

Participatory research methods have helped scientists to understand how farmers experiment and to seek partnerships with farmers in developing technologies with enhanced relevance and adoption. This paper reports on the development of a participatory methodology to systematize long-term experimentation with agroforestry systems carried out in a hotspot of biodiversity by non-governmental organizations and local farmers. A methodological guide for systematization and techniques used for Participatory Rural Appraisal formed the basis of our work. We propose an analytical framework that recognizes systems of reflexive and learning interactions, in order to make the learned lessons explicit. At the process level, the main lessons and recommendations are as follows. It is important to establish partnerships to conduct innovative and complex experimentation with agroforest. Participatory systematization allows us to improve the methodological aspects of design, implementation and management of on-farm participatory experimentation. It also serves to synthesize the main findings and to extract lessons from agroforestry systems experiments. It fosters the technical improvement of agroforestry systems. It creates possibilities for reflection on agroforestry systems by farmers, extensionists and researchers, as well as their learning with respect to management of such systems. The findings are placed in the context of current theory on participatory experimentation in agriculture. Extractive and interactive approaches help to produce rich insights of mutual interest through collaboration by identifying local, regional and global convergences, complementarities, and conflicts of interest; which affect the advance of new eco-friendly technologies, to both improve the livelihoods and to reverse biodiversity loss and environmental degradation.     

Structural ripening-related changes of the arabinan-rich pectic polysaccharides from olive pulp cell walls

In this study, the structural features and ripening-related changes that occur in the arabinan-rich pectic polysaccharides highly enmeshed in the cellulosic matrix of the olive pulp fruit were evaluated. These pectic polysaccharides, obtained from two consecutive harvests at green, cherry, and black ripening stages, account for 11-19% of the total pectic polysaccharides found in the olive pulp cell walls and were previously shown to occur as calcium chelating dimers. On the basis of the 13C NMR, (1H, 13C) gHSQC, 2D COSYPR, and (1H,13C) gHMBC carbon and proton resonances of the variously linked arabinosyl residues, we propose a tentative structure. This structure is particularly characterized by T-beta-Araf (1-->5)-linked to (1-->3,5)-Araf residues and by the occurrence of branched and linear blocks in the arabinan backbone. Methylation analysis showed that these pectic polysaccharides of black olives have more arabinan side chains, which were shorter (less (1-->5)-Araf), highly branched (more (1-->3,5)-Araf), and with shorter side chains (fewer (1-->3)-Araf) than those of green and cherry olives. Quantitative 13C NMR data indicated that these modifications involved the disappearance of the characteristic terminally linked beta-Araf residue of the arabinans. This odd feature can be used as a diagnostic tool in the evaluation of the stage of ripening of this fruit, as well as a marker for the presence of olive pulp in matrices containing pectic polysaccharides samples.