Chromatographic test facility. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

Test facility to verify design concepts and mathematical models of chromatograph for atmospheric composition analysis of Mar

Specialization of the rostral prefrontal cortex for distinct analogy processes

Analogical reasoning is central to learning and abstract thinking. It involves using a more familiar situation (source) to make inferences about a less familiar situation (target). According to the predominant cognitive models, analogical reasoning includes 1) generation of structured mental representations and 2) mapping based on structural similarities between them. This study used functional magnetic resonance imaging to specify the role of rostral prefrontal cortex (PFC) in these distinct processes. An experimental paradigm was designed that enabled differentiation between these processes, by temporal separation of the presentation of the source and the target. Within rostral PFC, a lateral subregion was activated by analogy task both during study of the source (before the source could be compared with a target) and when the target appeared. This may suggest that this subregion supports fundamental analogy processes such as generating structured representations of stimuli but is not specific to one particular processing stage. By contrast, a dorsomedial subregion of rostral PFC showed an interaction between task (analogy vs. control) and period (more activated when the target appeared). We propose that this region is involved in comparison or mapping processes. These results add to the growing evidence for functional differentiation between rostral PFC subregions

Technical and economic performances in organic sheep meat production: observations of breeding networks and experimental farms

A network of 42 sheep farms (including 13 in organic farming (OF)) shows that the gross margin per ewe is 24% lower in OF in the mountains because of high food costs and comparable in the lowlands because of the high level of food self-sufficiency based on the cultivation of fodder and grain; incomes are identical when structural costs are comparable. An analysis of four demonstration farms shows that, given the different conditions, specific livestock management is required depending on the presence of tillable land or not. If their proportion is limited, lambings are equally distributed between spring and autumn in order to maximise fodder self-sufficiency. When crops are possible, lambings are focused on autumn (with good sale prices), which requires the increased use of concentrates, some of which are produced on the farm. A five-year study revealed that these strategies lead to a convergence of between 80 and 90% food self-sufficiency. In suckling livestock in organic as well as conventional farming systems, high levels of forage and food self-sufficiency are essential to ensure economic viability within the context of rising grain prices

Production de viande ovine en agriculture biologique comparée à l’élevage conventionnel : résultats technicoéconomiques d’exploitations de plaine et de montagne du nord du Massif central

Durant les cinq dernières années, l’Agriculture Biologique (AB) a connu, en France, un développement inégalé : entre 1997 et 2002, la superficie conduite en AB a été multipliée par trois et les effectifs de brebis par cinq. Cette croissance s’accompagne d’un important besoin de références, en particulier technico-économiques. L’observation sur trois années de 24 exploitations ovines allaitantes en AB, comparées à 39 exploitations ovines allaitantes conventionnelles, met en évidence une certaine spécificité des élevages AB, tout en confirmant les principaux facteurs qui déterminent la marge par brebis et le revenu. Etant donné le prix des aliments concentrés en AB, 1,8 fois supérieur à celui des conventionnels, la quantité consommée est déterminante sur la marge par brebis. Elle peut être réduite en valorisant au mieux la surface fourragère. La plus-value sur la vente des agneaux en AB se réduit depuis trois ans, pour n’être plus en 2002 que de 16 % en zone de montagne et 0 % en zone de plaine. Le revenu hors aides CTE des éleveurs AB est de 39 % inférieur en montagne et de 57 % en plaine à celui des élevages conventionnels. Marge par brebis, productivité du travail et charges de structure sont déterminants sur le revenu. Dans le contexte actuel de cours favorables à l’agneau conventionnel, ne permettant que peu de plus-value sur l’agneau bio, le développement ou même simplement le maintien des élevages AB passe par des aides sur le long terme qui intégreraient les aspects environnementaux et, peut-être, la valeur santé des produits qui reste à démontrer

TECHNICAL AND ECONOMIC CONSTRAINTS IN ORGANIC SUCKLER SHEEP FARMING IN FRANCE. ANALYSIS IN A GROUP OF FARMS

The structures and the technical and economic results of 12 farms practising organic farming (Org) (eight upland and four lowland) were compared with those of 25 conventional farms (Conv) (14 and 11), over three years (2002-2004). The Org farms had smaller structures, fewer workers, and lower numerical productivity, especially in uplands (-16 % on average over three years) owing to lower flock intensification and sometimes because of sanitary problems. The key questions were above all economic with (i) the high cost of concentrates, the consumption of which remained high (extra cost per kg from 40 % to 60 % in 2004), and (ii) steadily decreasing average premium on meat price; only 9 % in uplands and 2 % in lowlands in 2004. Hence the gross margin per ewe was 20 % to 23 % lower on average over three years, than that on Conv farms. The impact on earnings was marked. Income is also strongly dependent on public subsidies, which are set to diminis

Heart enhancers with deeply conserved regulatory activity are established early in zebrafish development.

During the phylotypic period, embryos from different genera show similar gene expression patterns, implying common regulatory mechanisms. Here we set out to identify enhancers involved in the initial events of cardiogenesis, which occurs during the phylotypic period. We isolate early cardiac progenitor cells from zebrafish embryos and characterize 3838 open chromatin regions specific to this cell population. Of these regions, 162 overlap with conserved non-coding elements (CNEs) that also map to open chromatin regions in human. Most of the zebrafish conserved open chromatin elements tested drive gene expression in the developing heart. Despite modest sequence identity, human orthologous open chromatin regions recapitulate the spatial temporal expression patterns of the zebrafish sequence, potentially providing a basis for phylotypic gene expression patterns. Genome-wide, we discover 5598 zebrafish-human conserved open chromatin regions, suggesting that a diverse repertoire of ancient enhancers is established prior to organogenesis and the phylotypic period

Reduction of chromatographic data and evaluation of a GC model

Gas chromatograph, mass spectrometer system for chemical and biochemical determinations on Mars, and data reduction progra

Development of a recombinase polymerase amplification lateral flow assay for the detection of active Trypanosoma evansi infections

Author summary Neglected tropical diseases (NTDs) affecting humans and/or domestic animals severely impair the socio-economic development of endemic areas. One of these diseases, animal trypanosomosis, affects livestock and is caused by the parasites of the Trypanosoma genus. The most widespread causative agent of animal trypanosomosis is T. evansi, which is found in large parts of the world (Africa, Asia, South America, Middle East, and the Mediterranean). Proper control and treatment of the disease requires the availability of reliable and sensitive diagnostic tools. DNA-based detection techniques are powerful and versatile in the sense that they can be tailored to achieve a high specificity and usually allow the reliable detection of low amounts of parasite genetic material. However, many DNA-based methodologies (such as PCR) require trained staff and well-equipped laboratories, which is why the research community has actively investigated in developing amplification strategies that are simple, fast, cost-effective and are suitable for use in minimally equipped laboratories and field settings. In this paper, we describe the development of a diagnostic test under a dipstick format for the specific detection of T. evansi, based on a DNA amplification principle (Recombinase Polymerase Amplification aka RPA) that meets the above-mentioned criteria. Background Animal trypanosomosis caused by Trypanosoma evansi is known as "surra" and is a widespread neglected tropical disease affecting wild and domestic animals mainly in South America, the Middle East, North Africa and Asia. An essential necessity for T. evansi infection control is the availability of reliable and sensitive diagnostic tools. While DNA-based PCR detection techniques meet these criteria, most of them require well-trained and experienced users as well as a laboratory environment allowing correct protocol execution. As an alternative, we developed a recombinase polymerase amplification (RPA) test for Type A T. evansi. The technology uses an isothermal nucleic acid amplification approach that is simple, fast, cost-effective and is suitable for use in minimally equipped laboratories and even field settings. Methodology/Principle findings An RPA assay targeting the T. evansi RoTat1.2 VSG gene was designed for the DNA-based detection of T. evansi. Comparing post-amplification visualization by agarose gel electrophoresis and a lateral flow (LF) format reveals that the latter displays a higher sensitivity. The RPA-LF assay is specific for RoTat1.2-expressing strains of T. evansi as it does not detect the genomic DNA of other trypanosomatids. Finally, experimental mouse infection trials demonstrate that the T. evansi specific RPA-LF can be employed as a test-of-cure tool