Survey of Canine Dirofilaria immitis Infection in New Caledonia

Canine dirofilariosis is a frequent parasitic disease in New-Caledonia. A survey of canine heartworm (Dirofilaria immitis) infection among dogs from the cities of Tontouta, Nandaï and Nouméa, was performed in March 2009 using two antigen test kits; the microwell ELISA test: DiroCHE (Synbiotics Europe) and the Rapid Immuno Migration (RIM) test: WITNESS DIROFILARIA (Synbiotics Europe). Blood samples were collected from 64 dogs: 49 strays and 15 military working dogs. The military dogs received a permanent chemoprophylaxis (moxidectin). In 11 stray dogs, both tests were positive (22.4%). All the military dogs were negative, showing efficiency of chemoprophaxis. Results were discrepant in 6 dogs, negative with one test and doubtful with the other. Antigen heartworm test kits are available and reliable diagnostic tools. They are useful to evaluate the efficiency of chemoprophylaxis and to detect infected animals in order to treat them and to prevent the spreading of the disease

Human germinal center B cells differ from naive and memory B cells by their aggregated MHC class II‐rich compartments lacking HLA‐DO

To generate memory B cells bearing high‐affinity antibodies, naive B cells first encounter antigen in the T cell‐rich areas of secondary lymphoid organs. There, they are activated by antigen‐specific T cells and become germinal center (GC) founder B cells. GC founders enter the GC to become centroblasts that proliferate and mutate their BCR. Centroblasts differentiate into centrocytes that undergo selection, which requires both the recognition/capture of antigen on follicular dendritic cells and the presentation of processed antigen to GC T cells. Because at each stage of differentiation B cells act as antigen‐presenting cells, we analyzed their content of HLA‐DR+‐rich compartments (MIIC), as well as their expression of HLA‐DM, which catalyzes peptide loading of class II molecules, and HLA‐DO, which interacts with HLA‐DM and focuses MHC class II peptide loading on antigens internalized by the BCR. Naive and memory B cells concentrate HLA‐DR, ‐DM and ‐DO into compartments dispersed under the cell surface, which are identified by their expression of lysosome‐associated membrane protein (Lamp)‐1 as late endosomes/lysosomes. GC founders and GC B cells express larger Lamp‐1+DR+ compartments that are concentrated in the juxta‐nuclear region. These compartments express lower levels of HLA‐DM and virtually no HLA‐DO. Upon induction of a GC founder phenotype through the prolonged (days) co‐ligation of BCR and CD40, the naive B cell's peripheral DR+DM+Lamp‐1+ compartments aggregate in a polar fashion close to the nucleus. Furthermore, HLA‐DO expression virtually disappears, whereas low levels of HLA‐DM remain co‐localized with HLA‐DR. Anti‐κ/λ antibodies, used as surrogate antigens, are promptly (minutes) endocytosed in naive, memory and GC B cells. Then, naive and memory B cells target the surrogate antigen to their peripheral HLA‐DO+ MIIC, while GC B cells target it to their HLA‐DO- MIIC aggregates. Taken together, our results show that human GC B cells differ from naive and memory B cells by their aggregated MIIC that lack HLA‐D

A CH star in the globular cluster NGC 6426

We report on the serendipitous discovery of a carbon star near the centre of the low-metallicity globular cluster NGC 6426. We determined its membership and chemical properties using medium-resolution spectra. The radial velocity of -159 km/s makes it a member of the cluster. We used photometric data from the literature and the COMARCS stellar atmospheric models to derive its luminosity, effective temperature, surface gravity, metallicity, and approximate C, N, and O abundance ratios. According to these properties, we suggest that this star is a genuine carbon rich low-metallicity AGB star.Comment: 5 pages, accepted for publication in MNRA

Epidemiological study of canine trypanosomosis in an urban area of Ivory Coast

Following confirmed cases of trypanosomosis in military working dogs, c cross-sectional study was undertaken to evaluate the source of infection and determine the prevalence of canine infection with Trypanosoma congolense in the urban focus of Abidjan, Ivory Coast. Blood from 123 dogs were collected and subjected to PCR using specific primers for Trypanosoma congolense "forest type". In addition, an entomological study was conducted in an urban area near the forest surronding the military camp. The observed prevalence was 30.1% end PCR positivity to Trypanosoma congolense was not significantly associated with sex or age of animals. This study demonstrates the high contamination rate of dogs in enzootic zones, the potential risk of introduction of the disease in free animal populations and the ability of Glossina palpalis to adopt to urban areas and to transmit trypanosomosis in such areas. The factors leading to a possible emergence of canine trypanosomiasis in enzootic zones need further investigations

Multifrequency Study of The Radio Galaxy NGC326

We present the results of a multi-frequency study of the inversion symmetric radio galaxy NGC326 based on Very Large Array observations at 1.4, 1.6, 4.8, 8.5 and 14.9 GHz. The morphological, spectral and polarization properties of this peculiar object are studied at different levels of spatial resolutions. The interpretation of the data will be discussed in forthcoming papers.Comment: 15 pages, 15 ps figures, accepted by A&

Stars and gas in the very large interacting galaxy NGC 6872

The dynamical evolution of the large (> 100 kpc), barred spiral galaxy NGC 6872 and its small companion IC 4970 in the southern group Pavo is investigated. We present N-body simulations with stars and gas and 21 cm HI observations carried out with the Australia Telescope Compact Array of the large-scale distribution and kinematics of atomic gas. HI is detected toward the companion, corresponding to a gas mass of ca 1.3 10^9 Msun. NGC 6872 contains ca 1.4 10^{10} Msun of HI gas, distributed in an extended rotating disk. Massive concentrations of gas (10^9 Msun) are found at the tip of both tidal tails and towards the break seen in the optical northern arm near the companion. We detect no HI counterpart to the X-ray trail between NGC 6872 and NGC 6876, the dominant elliptical galaxy in the Pavo group located 8 arcmin to the southeast. At the sensitivity and the resolution of the observations, there is no sign in the overall HI distribution that NGC 6876 has affected the evolution of NGC 6872. There is no evidence of ram pressure stripping either. The X-ray trail could be due to gravitational focusing of the hot gas in the Pavo group behind NGC 6872 as the galaxy moves supersonically through the hot medium. The simulations of a gravitational interaction with a small nearby companion on a low-inclination prograde passage are able to reproduce most of the observed features of NGC 6872, including the general morphology of the galaxy, the inner bar, the extent of the tidal tails and the thinness of the southern tail.Comment: 12 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics. The resolution of the figures has been greatly reduced. The paper with the original figures can found at http://www.oso.chalmers.se/~horellou/PAPERS/2006n6872.pd

The Chemical Evolution of Starburst Nucleus Galaxies

The metallicities derived from spectroscopic observations of a sample of Starburst Nucleus Galaxies (SBNGs) are compared to those of several other types of galaxies (normal giant galaxies, Irregular and HII galaxies) drawn from the literature. The SBNGs are deficient in metals with respect to normal galaxies of same morphological type, suggesting that - SBNGs are galaxies still in the process of formation. Breaking the SBNGs into early-types (Sb and earlier) and late-types reveals that the former seem to follow the same linear luminosity-metallicity relation as the irregular and elliptical galaxies, whereas the latter and the giant spirals show comparable (0.2 and 0.3 dex) excess abundances with respect to the linear relation. This difference between the two types of SBNGs is consistent with the predictions of the model of hierarchical formation of galaxies: the early-type SBNGs are building their bulges by successive mergers of small stellar and gaseous systems, while the late-type SBNGs are mostly accreting gas to form a disk.Comment: accepted for publication in the ApJ Lette

Zoonotic abbreviata caucasica in wild chimpanzees (Pan troglodytes verus) from Senegal

Abbreviata caucasica (syn. Physaloptera mordens) has been reported in human and various non-human primates including great apes. The identification of this nematode is seldom performed and relies on egg characterization at the coproscopy, in the absence of any molecular tool. Following the recovery of two adult females of A. caucasica from the feces of wild Senegalese chimpanzees, morphometric characteristics were reported and new data on the width of the esophagus (0.268– 0.287 mm) and on the cuticle structure (0.70–0.122 mm) were provided. The molecular characterization of a set of mitochondrial (cox1, 16S rRNA, 12S rRNA) and nuclear (18S rRNA and ITS2) partial genes was performed. Our phylogenetic analysis indicates for the first time that A. caucasica is monophyletic with Physaloptera species. A novel molecular tool was developed for the routine diagnosis of A. caucasica and the surveillance of Nematoda infestations. An A. caucasica-specific qPCR targeting the 12S gene was assessed. The assay was able to detect up to 1.13 × 10−3 eggs/g of fecal matter irrespective of its consistency, with an efficiency of 101.8% and a perfect adjustment (R2 = 0.99). The infection rate by A. caucasica in the chimpanzee fecal samples was 52.08%. Only 6.19% of the environmental samples were positive for nematode DNA and any for A. caucasica. Our findings indicate the need for further studies to clarify the epidemiology, circulation, life cycle, and possible pathological effects of this infestation using the molecular tool herein developed