57 research outputs found

    Contribución al estudio de la flora y vegetación gipsofila de la provincia de Valladolid y sureste de la de Palencia

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    Cette recherche empirique a pour but d’étudier l’impact de la pratique de diverses formes d’organisation temporelle du travail posté. Après un rappel théorique, nous comparons trois types d’horaires de personnel infirmier au sein d’un même établissement hospitalier situé en Picardie (horaires fixes de nuit et horaires alternants) en vue de déterminer leurs conséquences sur les formes de sommeil, les comportements alimentaires, la vie sociale et familiale. Les résultats montrent que l’ampleur de ces conséquences n’est pas sans lien avec les divers éléments constitutifs d’une organisation temporelle du travail posté.This empirical study investigates the practical impact of different types of time-based organization of shiftwork. After a theoretical follow-up, we compare three types of staff schedules in the same hospital located in Picardy (fixed night schedules and alternating schedules) in order to determine their consequences on sleep, eating behavior, and social and family life. The results show that the extent of these consequences is related to different aspects of the time-based organization of shiftwork.Esta investigación empírica tiene el objetivo de estudiar el impacto de la práctica de diversas formas de organización temporal del trabajo por turno. Después de un recordatorio teórico, comparamos tres tipos de horarios de personal enfermero dentro del mismo centro hospitalario en Picardía (horarios fijos de noche y horarios en alternancia) con objetivo de determinar sus consecuencias sobre las formas de sueño, los comportamientos alimentarios y la vida social y familiar. Los resultados demuestran que el alcance de esta consecuencias tiene vínculos con los diversos elementos constitutivos de una organización temporal del trabajo por turno

    A synthetic rainbow trout linkage map provides new insights into the salmonid whole genome duplication and the conservation of synteny among teleosts

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    <p>Abstract</p> <p>Background</p> <p>Rainbow trout is an economically important fish and a suitable experimental organism in many fields of biology including genome evolution, owing to the occurrence of a salmonid specific whole-genome duplication (4<sup>th </sup>WGD). Rainbow trout is among some of the most studied teleosts and has benefited from substantial efforts to develop genomic resources (e.g., linkage maps. Here, we first generated a synthetic map by merging segregation data files derived from three independent linkage maps. Then, we used it to evaluate genome conservation between rainbow trout and three teleost models, medaka, stickleback and zebrafish and to further investigate the extent of the 4<sup>th </sup>WGD in trout genome.</p> <p>Results</p> <p>The INRA linkage map was updated by adding 211 new markers. After standardization of marker names, consistency of marker assignment to linkage groups and marker orders was checked across the three different data sets and only loci showing consistent location over all or almost all of the data sets were kept. This resulted in a synthetic map consisting of 2226 markers and 29 linkage groups spanning over 3600 cM. Blastn searches against medaka, stickleback, and zebrafish genomic databases resulted in 778, 824 and 730 significant hits respectively while blastx searches yielded 505, 513 and 510 significant hits. Homology search results revealed that, for most rainbow trout chromosomes, large syntenic regions encompassing nearly whole chromosome arms have been conserved between rainbow trout and its closest models, medaka and stickleback. Large conserved syntenies were also found between the genomes of rainbow trout and the reconstructed teleost ancestor. These syntenies consolidated the known homeologous affinities between rainbow trout chromosomes due to the 4<sup>th </sup>WGD and suggested new ones.</p> <p>Conclusions</p> <p>The synthetic map constructed herein further highlights the stability of the teleost genome over long evolutionary time scales. This map can be easily extended by incorporating new data sets and should help future rainbow trout whole genome sequence assembly. Finally, the persistence of large conserved syntenies across teleosts should facilitate the identification of candidate genes through comparative mapping, even if the occurrence of intra-chromosomal micro-rearrangement may hinder the accurate prediction their genomic location.</p

    Resistance to a Rhabdovirus (VHSV) in Rainbow Trout: Identification of a Major QTL Related to Innate Mechanisms

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    Chantier qualité GAHealth control is a major issue in animal breeding and a better knowledge of the genetic bases of resistance to diseases is needed in farm animals including fish. The detection of quantitative trait loci (QTL) will help uncovering the genetic architecture of important traits and understanding the mechanisms involved in resistance to pathogens. We report here the detection of QTL for resistance to Viral Haemorrhagic Septicaemia Virus (VHSV), a major threat for European aquaculture industry. Two induced mitogynogenetic doubled haploid F2 rainbow trout (Oncorhynchus mykiss) families were used. These families combined the genome of susceptible and resistant F0 breeders and contained only fully homozygous individuals. For phenotyping, fish survival after an immersion challenge with the virus was recorded, as well as in vitro virus replication on fin explants. A bidirectional selective genotyping strategy identified seven QTL associated to survival. One of those QTL was significant at the genome-wide level and largely explained both survival and viral replication in fin explants in the different families of the design (up to 65% and 49% of phenotypic variance explained respectively). These results evidence the key role of innate defence in resistance to the virus and pave the way for the identification of the gene(s) responsible for resistance. The identification of a major QTL also opens appealing perspectives for selective breeding of fish with improved resistance

    Quantitative trait loci for resistance to Flavobacterium psychrophilum in rainbow trout: effect of the mode of infection and evidence of epistatic interactions.

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    BACKGROUND: Bacterial cold-water disease, which is caused by Flavobacterium psychrophilum, is one of the major diseases that affect rainbow trout (Oncorhynchus mykiss) and a primary concern for trout farming. Better knowledge of the genetic basis of resistance to F. psychrophilum would help to implement this trait in selection schemes and to investigate the immune mechanisms associated with resistance. Various studies have revealed that skin and mucus may contribute to response to infection. However, previous quantitative trait loci (QTL) studies were conducted by using injection as the route of infection. Immersion challenge, which is assumed to mimic natural infection by F. psychrophilum more closely, may reveal different defence mechanisms. RESULTS: Two isogenic lines of rainbow trout with contrasting susceptibilities to F. psychrophilum were crossed to produce doubled haploid F2 progeny. Fish were infected with F. psychrophilum either by intramuscular injection (115 individuals) or by immersion (195 individuals), and genotyped for 9654 markers using RAD-sequencing. Fifteen QTL associated with resistance traits were detected and only three QTL were common between the injection and immersion. Using a model that accounted for epistatic interactions between QTL, two main types of interactions were revealed. A "compensation-like" effect was detected between several pairs of QTL for the two modes of infection. An "enhancing-like" interaction effect was detected between four pairs of QTL. Integration of the QTL results with results of a previous transcriptomic analysis of response to F. psychrophilum infection resulted in a list of potential candidate immune genes that belong to four relevant functional categories (bacterial sensors, effectors of antibacterial immunity, inflammatory factors and interferon-stimulated genes). CONCLUSIONS: These results provide new insights into the genetic determinism of rainbow trout resistance to F. psychrophilum and confirm that some QTL with large effects are involved in this trait. For the first time, the role of epistatic interactions between resistance-associated QTL was evidenced. We found that the infection protocol used had an effect on the modulation of defence mechanisms and also identified relevant immune functional candidate genes

    Identifying Fishes through DNA Barcodes and Microarrays

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    Background: International fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection. Methodology/Principal Findings: This study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S), cytochrome b (cyt b), and cytochrome oxidase subunit I (COI) for the identification of 50 European marine fish species by combining techniques of ‘‘DNA barcoding’’ and microarrays. In a DNA barcoding approach, neighbour Joining (NJ) phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the ‘‘position of label’’ effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (.90%) renders the DNA barcoding marker as rather unsuitable for this high-throughput technology. Conclusions/Significance: Based on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products

    The Athena X-ray Integral Field Unit (X-IFU)

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    The X-ray Integral Field Unit (X-IFU) is the high resolution X-ray spectrometer of the ESA Athena X-ray observatory. Over a field of view of 5' equivalent diameter, it will deliver X-ray spectra from 0.2 to 12 keV with a spectral resolution of 2.5 eV up to 7 keV on similar to 5 '' pixels. The X-IFU is based on a large format array of super-conducting molybdenum-gold Transition Edge Sensors cooled at similar to 90 mK, each coupled with an absorber made of gold and bismuth with a pitch of 249 mu m. A cryogenic anti-coincidence detector located underneath the prime TES array enables the non X-ray background to be reduced. A bath temperature of similar to 50 mK is obtained by a series of mechanical coolers combining 15K Pulse Tubes, 4K and 2K Joule-Thomson coolers which pre-cool a sub Kelvin cooler made of a He-3 sorption cooler coupled with an Adiabatic Demagnetization Refrigerator. Frequency domain multiplexing enables to read out 40 pixels in one single channel. A photon interacting with an absorber leads to a current pulse, amplified by the readout electronics and whose shape is reconstructed on board to recover its energy with high accuracy. The defocusing capability offered by the Athena movable mirror assembly enables the X-IFU to observe the brightest X-ray sources of the sky (up to Crab-like intensities) by spreading the telescope point spread function over hundreds of pixels. Thus the X-IFU delivers low pile-up, high throughput (> 50%), and typically 10 eV spectral resolution at 1 Crab intensities, i.e. a factor of 10 or more better than Silicon based X-ray detectors. In this paper, the current X-IFU baseline is presented, together with an assessment of its anticipated performance in terms of spectral resolution, background, and count rate capability. The X-IFU baseline configuration will be subject to a preliminary requirement review that is scheduled at the end of 2018. The X-IFU will be provided by an international consortium led by France, the Netherlands and Italy, with further ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Ireland, Poland, Spain, Switzerland and contributions from Japan and the United States.Peer reviewe

    Prospecting potential links between PRRSV infection susceptibility of alveolar macrophages and other respiratory infectious agents present in conventionally reared pigs

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    International audiencePorcine Reproductive and Respiratory Syndrome virus (PRRSV) is one of the main component of the porcine respiratory disease complex (PRDC), which strongly impact the pig production. Although PRRSV is often considered as a primary infection that eases subsequent respiratory coinfections, the possibility that other PRDC components may facilitate PRRSV infection has been largely overlooked. The main cellular targets of PRRSV are respiratory macrophages among them alveolar macrophages (AM) and pulmonary intravascular macrophages (PIM). AM, contrarily to PIM, are directly exposed to the external respiratory environment, among them co-infectious agents. In order to explore the possibility of a co-infections impact on the capacity of respiratory macrophages to replicate PRRSV, we proceed to in vitro infection of AM and PIM sampled from animals presenting different sanitary status, and tested the presence in the respiratory tract of these animals of the most common porcine respiratory pathogens (PCV2, Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma floculare, Pasteurella multocida, Bordetella bronchiseptica, Streptoccocus suis). In this exploratory study with a limited number of animals, no statistic differences were observed between AM and PIM susceptibility to in vitro PRRSV infection, nor between AM coming from animals presenting very contrasting respiratory coinfection loads

    A first insight into the effect of Lotilaner on GABA-gated channels from the european tick Ixodes ricinus

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    Ticks are strict blood-feeding arthropods (Acari), which represent a major health issue for wild or domesticated animals and humans, due to their potential to transmit disease agents. Control of ticks is increasingly difficult due to the development of drug-resistant parasites. Ligand-gated ion channels of the tick central nervous system are the primary targets of acaricides. Among those receptors, the γ-aminobutyric acid-gated chloride ion channels (GABACls) are the main synaptic inhibitory receptors. Lotilaner is a recently developed parasiticide from the isoxazoline chemical class that was shown to be a non-competitive antagonist of GABACls from the livestock tick Rhipicephalus microplus. In the present study, we characterized the GABACls from the European tick species Ixodes ricinus. We extracted RNAs from Ixodes ricinus nymphs. Taking advantage of the phylogenetic closeness of I. ricinus and R. microplus in the Arthropoda phylum, we identified the I. ricinus GABACl subunit homologue. The cDNA encoding the Iri- GABACl was cloned and the corresponding in vitro synthesized cRNAs were micro-injected into Xenopus laevis oocytes to investigate its pharmacological properties. Functional expression and two-electrode voltage clamp studies demonstrated that the GABACl subunit formed a homomeric receptor gated by GABA. Importantly, the insecticides like lotilaner, fipronil and picrotoxin efficiently blocked the GABA currents as previously observed for the R. microplus GABACl. Surprisingly, I. ricinus GABACl was not sensitive to the pesticide dieldrin, suggesting a potential naturally existing resistance mechanism involving alternative exons. Here we report the functional characterization of the first GABACl of I. ricinus demonstrating that it is an important molecular target for lotilaner. Transcriptomic analysis of I. ricinus are in progress to identify new acaricidal targets
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