The X-CLASS - redMaPPer galaxy cluster comparison: I. Identification procedures

We performed a detailed and, for a large part interactive, analysis of the matching output between the X-CLASS and redMaPPer cluster catalogues. The overlap between the two catalogues has been accurately determined and possible cluster positional errors were manually recovered. The final samples comprise 270 and 355 redMaPPer and X-CLASS clusters respectively. X-ray cluster matching rates were analysed as a function of optical richness. In a second step, the redMaPPer clusters were correlated with the entire X-ray catalogue, containing point and uncharacterised sources (down to a few 10^{-15} erg s^{-1} cm^{-2} in the [0.5-2] keV band). A stacking analysis was performed for the remaining undetected optical clusters. Main results show that neither of the wavebands misses any massive cluster (as coded by X-ray luminosity or optical richness). After correcting for obvious pipeline short-comings (about 10% of the cases both in optical and X-ray), ~50% of the redMaPPer (down to a richness of 20) are found to coincide with an X-CLASS cluster; when considering X-ray sources of any type, this fraction increases to ~ 80%; for the remaining objects, the stacking analysis finds a weak signal within 0.5 Mpc around the cluster optical centers. The fraction of clusters totally dominated by AGN-type emission appears to be of the order of a few percent. Conversely ~ 40% of the X-CLASS clusters are identified with a redMaPPer (down to a richness of 20) - part of the non-matches being due to the fact that the X-CLASS sample extends further out than redMaPPer (z<1 vs z<0.6); extending the correlation down to a richness of 5, raises the matching rate to ~ 65%.Comment: 15 pages, 20 figures, 2 table

Assessing the genetic diversity and the temporal evolution of plant populations for an optimized conservation: the example of the tuberous-rooted chervil.

International audienc

Activation of Brainstem Neurons by Underwater Diving in the Rat

The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different than that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii (NTS), the nucleus raphe pallidus (RPa), the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker–Fuse area, and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the NTS, A5 area, and RPa were significantly different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response

Is there variety × isolate interaction in the polygenic quantitative resistance of carrot to Alternaria dauci ?

Horizontal and polygenic resistance is race-nonspecific and, therefore, more durable, unlike vertical resistance, which is race-specific and unstable. However, this division is perhaps not so obvious since some cultivar × isolate interactions have already been observed for plant species with partial resistance. Carrot is known to be partially resistant to Alternaria dauci, but it is relevant for breeders to study cultivar × isolate interactions in order to develop durable resistant varieties. For this purpose, 12 highly diverse carrot genotypes and one segregating population were inoculated in a tunnel or in a glass house with 11 isolates of A. dauci that also represented a high diversity in terms of geographical origin, aggressiveness and genetic diversity. Disease severity values were assessed three times in the tunnel in a one-year experiment (2002) and twice in the glass house in an experiment over two consecutive years (2011 and 2012). The interaction of isolate with genotype was non-significant in the tunnel, and the same result was obtained in the glasshouse for both years of study except for the first scoring date in 2011, suggesting that the partial resistance of carrot to A. dauci is probably mainly explained by major QTLs that confer resistance to a large number of isolates and, potentially, some minor isolate-specific QTLs as well

Is quantitative resistance qualitative? An example with two Alternaria Leaf Blight resistant carrot genotypes and four resistance assessment techniques

International audienc

Is host range of carrot restricted to Alternaria dauci?

International audienc

First case of Chlamydia trachomatis L2b proctitis in a woman

AbstractSince 2003, outbreaks of lymphogranuloma venereum (LGV) have been reported in European countries, North America, and Australia. Current LGV cases have been caused by Chlamydia trachomatis serovar L2. This sexually transmitted infection is predominantly found among men who have sex with men, specifically men who are seropositive for human immunodeficiency virus and have clinical signs of proctitis. The current outbreak has been almost exclusively attributed to a new variant, designated L2b. Although urogenital cases of LGV have been described in the heterosexual population, we report the first case of C. trachomatis L2b proctitis in a woman

Evaluation of different methods for the characterization of carrot resistance to the alternaria leaf blight pathogen (Alternaria dauci) revealed two qualitatively different resistances

Alternaria leaf blight (ALB), caused by Alternaria dauci, is one of the most damaging foliar diseases of carrot worldwide. The aim of this study was to compare different methods for evaluating levels of carrot resistance to ALB. Three techniques were investigated by comparison with a visual disease assessment control: in vivo conidial germination, a bioassay based on a drop-inoculation method, and in planta quantification of fungal biomass by quantitative PCR (Q-PCR). Three carrot cultivars showing different degrees of resistance to A. dauci were used, i.e. a susceptible cultivar (Presto) and two partially resistant genotypes (Texto and Bolero), challenged with an aggressive or a very aggressive isolate of A. dauci. Both partially resistant genotypes produced a higher mean number of germ tubes per conidium (up to 3·42±0·35) than the susceptible one (1·26±0·18). The drop-inoculation results allowed one of the partially resistant genotypes (Bolero, log10(S+1) = 1·34±0·13) to be distinguished from the susceptible one (1·90±0·13). By contrast, fungal growth measured by Q-PCR clearly differentiated the two partially resistant genotypes with log10(I) values of 2·77±0·13 compared to the susceptible cultivar (3·65±0·13) at 15 days post-inoculation. This result was strongly correlated (r2 = 0·91) with the disease severity index scored at the same date. Data obtained with the different assessment methods strongly suggest that the Texto and Bolero genotypes have different genetic resistance sources

Evaluating aggressiveness and host range of Alternaria dauci in a controlled environment

The aggressiveness of Alternaria dauci isolates was investigated in greenhouse conditions. Twenty-seven isolates were pre-selected from a large collection to represent high diversity according to geographic or host origins and intergenic spacer (IGS) polymorphism. IGS sequence analysis revealed that isolates were grouped within three different clusters. Eleven isolates were selected and inoculated on a susceptible carrot cultivar. Three criteria (mean lesion number, mean necrotic leaf area and mean disease index) were used to assess the aggressiveness of isolates. Continuous variation in aggressiveness was shown and no clear division into isolate classes was evident. For the host range study, two isolates were inoculated under greenhouse conditions onto nine cultivated Apiaceae species, two wild Daucus species and six cultivated non-Apiaceae species representing six botanical families. Lesions varying in severity were observed on all dicot species (Apiaceae and non-Apiaceae), but no symptoms developed on the two monocots studied (leek and sweetcorn). Plant species were also differentiated on the basis of expanding lesions (cultivated and wild carrot, dill and fennel) or non-expanding lesions (other dicot species). Typical A. dauci conidia were observed after in vitro incubation of leaves with symptoms. Fungal structures were isolated from lesions and A. dauci was confirmed on the basis of conidial morphology and specific conventional PCR results. Genotyping of individual isolates performed with microsatellite markers confirmed the presence of the inoculated isolate. The results clearly showed that, in controlled conditions, the host range of A. dauci is not restricted to carrot