919 research outputs found
SYAL : UN NOUVEL OUTIL POUR LE DEVELOPPEMENT DE TERRITOIRES MARGINAUX. LES LEĂONS DE L'ALLIANCE DES AGRO-INDUSTRIES RURALES DE LA SELVA LACANDONA, CHIAPAS.
N° ISBN - 978-2-7380-1284-5International audienceSince its beginnings in the eighties, Rural Agro-Industry (RAI) has emerged as an effective way to fight against poverty in marginalized rural areas, because of its ability to contribute to the overall improvement of small producers' living conditions. This development tool has been completed in the nineties by the Localized Agri-food Systems concept (SYAL in French) and the process of their activation. From the experience of a RAI development project promoted in the Selva Lacandona (Chiapas, Mexico), we present some lessons learned from this development project. One of the principal results was to identify and define the conditions of RAI sustainability in the Selva Lacandona. If economics profitability of the micro-enterprises proved to be essential to ensure their viability, it does not seem central as it doesn't represent a real problem. On the other hand, two aspects appeared to be fundamental to guarantee the RAI sustainable development in such marginalized region: the necessity of a prior favorable environment, in particular trough the presence of functional local public goods, and the resolution of organization and leadership problems
Measuring connectedness among herds in mixed linear models: From theory to practice in large-sized genetic evaluations
A procedure to measure connectedness among groups in large-sized genetic evaluations is presented. It consists of two steps: (a) computing coefficients of determination (CD) of comparisons among groups of animals; and (b) building sets of connected groups. The CD of comparisons were estimated using a sampling-based method that estimates empirical variances of true and predicted breeding values from a simulated n-sample. A clustering method that may handle a large number of comparisons and build compact clusters of connected groups was developed. An aggregation criterion (Caco) that reflects the level of connectedness of each herd was computed. This procedure was validated using a small beef data set. It was applied to the French genetic evaluation of the beef breed with most records and to the genetic evaluation of goats. Caco was more related to the type of service of sires used in the herds than to herd size. It was very sensitive to the percentage of missing sires. Disconnected herds were reliably identified by low values of Caco. In France, this procedure is the reference method for evaluating connectedness among the herds involved in on-farm genetic evaluation of beef cattle (IBOVAL) since 2002 and for genetic evaluation of goats from 2007 onwards
Technical note: Influence of the drying position and time on the persistence of gunshot residues on fabrics
The influence of the drying position and time on the persistence of gunshot residues (GSR) on fabrics was investigated. Powder tattooing from a 40 cm shooting distance on targeted fabrics were slightly wetted using a spray and dried for 3 h or 48 h in horizontal or vertical positions. The GSR particles were visualised using IR fluorescence with a Video Spectral Comparator (VSC) and automatically counted with a software before the wetting and after the drying stages. While a significant rate of GSR particles (up to 22 %) were lost, it was mainly due to the wetting procedure rather than the drying stage. No statistically significant difference was observed between the drying positions, indicating that both drying positions can be used in practice to dry slightly wet fabrics. The drying time had no influence on the loss, and the GSR distribution was not significantly influenced by either factor (i.e., time and position)
High cadmium concentrations in Jurassic limestone as the cause for elevated cadmium levels in deriving soils: a case study in Lower Burgundy, France
Cadmium (Cd) is a highly toxic element and its presence in the environment needs to be closely monitored. Recent systematic surveys in French soils have revealed the existence of areas in eastern and central France, which show systematically high cadmium concentrations. It has been suggested that at least part of these anomalous levels are of natural origin. For the Lower Burgundy area in particular, a direct heritage from the Jurassic limestone bedrock is highly suspected. This potential relationship has been studied in several localities around Avallon and this study reports new evidence for a direct link between anomalously elevated cadmium contents of Bajocian and Oxfordian limestone and high cadmium concentrations in deriving soils. Soils in this area show cadmium concentrations generally above the average national population values, with contents frequently higher than the âupper whisker' value of 0.8ÎŒggâ1 determined by statistical evaluation. In parallel, limestone rocks studied in the same area exhibit cadmium concentrations frequently exceeding the mean value of 0.030-0.065ÎŒggâ1 previously given for similar rocks by one order of magnitude, with a maximum of 2.6ÎŒggâ1. Mean ratios between the cadmium concentrations of limestone bedrock and deriving soils (Cdsoil/Cdrock), calculated for different areas, range from 4.6 to 5.7. Calculations based on the analyses of both soils from a restricted area and fragments of bedrock sampled in the immediate vicinity of high-concentration soils are around 5.5-5.7. Cdsoil/Cdrock is useful in determining the potential of soils in Lower Burgundy to reflect and exacerbate the high concentrations of cadmium present in parent bedrock
Periodontal pathogens of the interdental microbiota in a 3âmonths pregnant population with an intact periodontium
Steroid hormones and the oral microbiota of pregnant women both appear as cumulative risk factors for gingivitis. This cross-sectional study, using real-time PCR, investigated the composition and diversity of the microbiota in interdental spaces of 3âmonths pregnant women with intact periodontium according the 2018 EFP/AAP classification. Bacteria identified were belonged to the red (Porphyromonas gingivalis Treponema denticola, and Tanerella forsythia), orange (Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Parvimonas micra), and green (Eikenella corrodens and A. actinomycetencomitans) Socransky complexes. Approximatively 109.11 bacteria were counted per interdental space in pregnant women. Bacteria from the red complex represented 33.80% versus 62.81% for the orange group versus 3.39% for the green group of the total number spread over the 3 groups. Dietary habits and physical activity did not have a significant impact on interdental microbiota, although a decrease in the median amount of 9 periodontopathogens was observed when fruit and vegetable consumption increased. Pregnant women who brushed their teeth at least twice a day had lower counts of total bacteria and 9 periodontal pathogens than those who brushed less. In 3âmonths pregnant women at high risk of periodontal disease (>30% bleeding sites), the dendogram revealed 2 clusters of the 9 periodontopathogens. This provides further support for the âkey pathogenâ hypothesis, among which Porphyromonas gingivalis plays a key role, indicating that specific bacteria in limited quantities can influence the host immune system and convert the microbiota from symbiotic to dysbiotic to induce inflammatory disorder. As a result, this study reported that 3âmonths pregnant women with healthy periodontium had high levels of interdental bleeding and a dysbiotic microbiota with periodontal pathogens of the Socransky orange and red complexes. These subjects were therefore potentially at increased risk of developing periodontal disease and, consequently, an adverse pregnancy outcome. So, preventive oral prophylaxis measures, in particular individual interdental prophylaxis, should be implemented as soon as pregnancy is established
Fast and robust single particle reconstruction in 3D fluorescence microscopy
Single particle reconstruction has recently emerged in 3D fluorescence
microscopy as a powerful technique to improve the axial resolution and the
degree of fluorescent labeling. It is based on the reconstruction of an average
volume of a biological particle from the acquisition multiple views with
unknown poses. Current methods are limited either by template bias, restriction
to 2D data, high computational cost or a lack of robustness to low fluorescent
labeling. In this work, we propose a single particle reconstruction method
dedicated to convolutional models in 3D fluorescence microscopy that overcome
these issues. We address the joint reconstruction and estimation of the poses
of the particles, which translates into a challenging non-convex optimization
problem. Our approach is based on a multilevel reformulation of this problem,
and the development of efficient optimization techniques at each level. We
demonstrate on synthetic data that our method outperforms the standard
approaches in terms of resolution and reconstruction error, while achieving a
low computational cost. We also perform successful reconstruction on real
datasets of centrioles to show the potential of our method in concrete
applications
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