29 research outputs found

    Rôle et place du riz pluvial dans les exploitations du Vakinankaratra (Hauts Plateaux et Moyen Ouest)

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    International audienceDans la région des Hautes Terres, zone montagneuse dont les plaines et les bas fond irrigués sont dominés par de forts reliefs, l'accroissement de la pression démographique s'est traduit par la saturation des terres irriguées, destinées à la riziculture, et par une emprise agricole de plus en plus forte sur les terres de versant. La conduite des cultures de versant (Tanety), ou cultures pluviales, selon les techniques traditionnelles de travail du sol, combiné à l'abondance des pluies, accentue les phénomènes d'érosion et conduit donc à une forte perte de fertilité. De plus, la dégradation des sols en amont se traduit très souvent par l'ensablement et des dégâts sur les infrastructures et parcelles irriguées situées en aval. Ainsi, ces systèmes ne permettent pas, du fait de la fragilité de l'écosystème, de concilier les objectifs de production et de durabilité. Pour faire évoluer ces systèmes vers plus de durabilité, il convient d'améliorer les connaissances sur les pratiques des exploitants. Cette communication présente les résultats de deux diagnostics agraires réalisé en 2007 dans la commune d'Andranomanelatra, à la périphérie d'Antsirabe, sur les hauts plateaux de Madagascar et en 2008/2009 dans le reste du Vakinankaratra, hauts plateaux et moyen-ouest, ainsi que des résultats obtenus et sortis de la base de données parcelle (BDD) du projet BVPI SE/HP. Des typologies d'exploitations sont présentées pour mieux identifier les contraintes et opportunités de chaque type et la place du riz pluvial dans la formation du revenu ou la satisfaction des besoins alimentaires. On examinera l'opportunité que représente le riz pluvial pour les agriculteurs de la région sans oublier les autres opportunités ou alternatives présentes dans la zone qui semblent plus adaptées à des contextes très différenciés des hauts plateaux. La discussion portera sur les enjeux agricoles à venir et la place que peut y jouer le riz pluvial

    CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

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    Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

    Analysis of coastal and offshore aquaculture: application of the FARM model to multiple systems and shellfish species

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    The Farm Aquaculture Resource Management (FARM) model has been applied to several shellfish species and aquaculture types. The performance of the FARM model, developed to simulate potential harvest, key financial data, and water quality impacts at the farm-scale, was tested in five systems in the European Union: Loch Creran, Scotland (Pacific oyster), Pertuis Breton, France (blue mussel), Bay of Piran, Slovenia (Mediterranean mussel), Chioggia, Italy (Mediterranean mussel) and Ria Formosa, Portugal (Manila clam). These systems range from open coasts to estuaries, and are used for shellfish aquaculture by means of different cultivation techniques (e.g. oyster bottom culture in Loch Creran and mussel longlines and poles in Pertuis Breton). The drivers for the FARM model were supplied by measured data, outputs of system-scale models or a combination of both. The results (given in total fresh weight) generally show good agreement with reported annual production (shown in brackets) at each farm: simulated production of 134 tons of Pacific oyster in Loch Creran (150 tons, −10%), 2691 tons of blue mussel in Pertuis Breton (2304 tons, +17%), 314 tons of Mediterranean mussel in the Bay of Piran (200 tons, +57%), 545 tons of Mediterranean mussel in Chioggia (660 tons, −17%) and 119 tons of Manila clam in Ria Formosa (104 tons, +15%). The nitrogen mass balance for each farm was also determined with the FARM model. The net removal of nitrogen (N) by the farms was estimated to correspond to 1206 population equivalents per year (PEQ y−1) in Loch Creran, 93503 PEQ y−1 in Pertuis Breton, 9196 PEQ y−1 in the Bay of Piran, 97916 PEQ y−1 in Chioggia and 8613 PEQ y−1 in Ria Formosa. The aggregate income due to both the shellfish sale and substitution value of landbased fertilizer reduction or nutrient treatmentwas estimated to be about 700 k€ y−1 in Loch Creran, 30,706 k€ y−1 in Pertuis Breton, 3000 k€ y−1 in the Bay of Piran, 30,000 k€ y−1 in Chioggia, and 5000 k€ y−1in Ria Formosa. Outputs of FARM may be used to analyse the farm production potential and profit maximization according to seeding densities and/or spatial distribution. Results of a marginal analysis for all the study sites were determined. As an example, profit maximization in Loch Creranwas obtained with 97 tons of seed, resulting in a total production of 440 tons (profit of 2100 k€ for a culture period of about 2 years). FARM additionally integrates the well-known ASSETS model, for assessment of farm-related eutrophication impacts. The assessment results for the five study sites show that water quality is either maintained or improved in all farms under standard conditions of culture practice. FARM results may be used by farmers to analyse farm production potential and by managers for environmental assessment of farm-relatedwater quality impacts,whether positive or negative. It is a useful tool for all stakeholders for the valuation of nitrogen credits, which may be traded as part of an integrated catchment management plan. The FARM results were scaled up to determine a net value of 11–17 billion € y−1 of ecosystem goods and services, provided by shellfish culture towards reducing eutrophication in the coastal waters of the European Union. These numbers highlight the role that extractive organic aquaculture plays in integrated coastal zone and nutrient emissions management

    Population structure, growth and production of the wedge clam Donax hanleyanus (Bivalvia: Donacidae) from northern Argentinean beaches

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    Donax hanleyanus Philippi, 1847 (Bivalvia: Donacidae) dominates fine to coarse sandy beach communities of the northern Argentinean Atlantic coast. The population biology of this intertidal wedge clam was studied by determining population structure, growth and production at the three locations Santa Teresita, Mar de las Pampas (both from December 2005 to December 2006) and Faro QuerandıŽ (from March 2005 to December 2006). Von Bertalanffy growth functions were established from length-frequency distributions using an asymptotic length (LN) of 44 mm and the growth constants (K) of 0.46 and 0.47 y1 respectively of Mar de las Pampas and Faro QuerandıŽ. Compared with growth studies four decades ago, D. hanleyanus today is growing more slowly, but is reaching a higher maximum length. Longevity is estimated to be approximately five years. The present study confirms that the overall growth performance index is habitat-specific, grouping Donacidae into tropical/subtropical, temperate and upwelling species. The intertidal biomass of D. hanleyanus ranged between 0.04 and 1.32 g ash-free dry mass (AFDM) m2yr1. Individual production revealed the highest value at 30 mm length (0.16 g AFDM m2yr1) and annual production ranged between 0.08 and 0.99 g AFDMm2yr1, resulting in renewal rate values (P/B) between 0.82 and 2.16. The P/B ratios of D. hanleyanus populations increased with decreasing latitude from temperate to tropical regions. Only at Santa Teresita D. hanleyanus was found living with the sympatric yellow clam Mesodesma mactroides. A significant negative correlation between abundances of both surf clams suggests that abundance peaks of D. hanleyanus are related with population crashes of M. mactroides. Spatial differences in abundance are significantly related to sand texture as confirmed by nonmetrical multidimensional scaling, but not to sea surface temperature. However, the decrease of D. hanleyanus seems to be principally related to human activities

    Reproductive cycle of the commercially harvested sea urchin (Paracentrotus lividus) along the western coast of Portugal

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    Harvested populations of the sea urchin (Paracentrotus lividus) from the northwestern (Carreco) and southwestern (Aljezur) coasts of Portugal were surveyed to describe the species reproductive cycle and assess possible relationships with geographical location and seawater temperature. Individuals were sampled monthly to analyze gonad histology, mean gonadal index (GI), and gonadosomatic index (GSI) during 2 consecutive years (November 2010-November 2012). Both populations presented an annual reproductive cycle, with synchronous gonad maturation and gamete release between sexes. Gonad maturation occurred throughout autumn-winter, followed by a single but prolonged spawning season during spring-summer. The duration of the spawning season displayed a latitudinal gradient likely related to the north-south increasing trend in seawater temperature, with the northwestern population (Carreco) exhibiting a shorter spawning period compared to the southwestern population (Aljezur). The timing and duration of the spawning season was compared with several populations throughout the distributional range of P. lividus in the Atlantic Ocean and Mediterranean Sea. In the population from Carreco, the size at first sexual maturity (test diameter = 35.9 mm) was considerably smaller than the minimum conservation reference size (MCRS) of 50 mm test diameter legally established for P. lividus. This study confirms that sustainable exploitation depends on harvesters' awareness of and compliance with the MCRS and provides useful information for the eventual establishment of a closed season in the harvesting of P. lividus.Fisheries Operational ProgrammeEuropean Maritime and Fisheries Fun

    Mutations in L-type amino acid transporter-2 support SLC7A8 as a novel gene involved in age-related hearing loss

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    Age-related hearing loss (ARHL) is the most common sensory deficit in the elderly. The disease has a multifactorial etiology with both environmental and genetic factors involved being largely unknown. SLC7A8/SLC3A2 heterodimer is a neutral amino acid exchanger. Here, we demonstrated that SLC7A8 is expressed in the mouse inner ear and that its ablation resulted in ARHL, due to the damage of different cochlear structures. These findings make SLC7A8 transporter a strong candidate for ARHL in humans. Thus, a screening of a cohort of ARHL patients and controls was carried out revealing several variants in SLC7A8, whose role was further investigated by in vitro functional studies. Significant decreases in SLC7A8 transport activity was detected for patient’s variants (p.Val302Ile, p.Arg418His, p.Thr402Met and p.Val460Glu) further supporting a causative role for SLC7A8 in ARHL. Moreover, our preliminary data suggest that a relevant proportion of ARHL cases could be explained by SLC7A8 mutations
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