Preliminary results of a study of magnetic properties in the Foum-Zguid dyke (Morocco)

This work focuses on the study of flow and propagation of magma using rock magnetic analyses along sections across the thick Jurassic dyke of Foum-Zguid (Southern Morocco). Thermomagnetic data show that Ti-poor titanomagnetite is the main magnetic carrier. Petrographic analysis shows that the main Ti phase (ilmenite) occurs either as lamellae within spinel (center of the dyke) or as isolated grains (dyke margin). Bulk magnetic properties display distinct behavior according to the distance to the dyke margin; grain size of the main magnetic carrier decreases towards the center of the dyke, while the natural remanent magnetization and the bulk magnetic susceptibility increase. Only the magnetic susceptibility ellipsoid close to the dyke margin corresponds to that usually found in thin dykes, with the magnetic foliation sub parallel to dyke margins. Maximum principal axis is in most cases either parallel or perpendicular to the intersection between the planes of magnetic foliation and dyke wall. Moreover, when this axis is perpendicular to the intersection it is associated with a more oblate magnetic susceptibility ellipsoid shape, indicating the presence of complex magnetic fabrics. The studied magnetic properties show that, in this 100 m wide thick dyke, flow structures related with dyke propagation are only preserved close to the quickly cooled dyke margins. (C) 2004 Elsevier Ltd. All rights reserved

The role of sulfoglucuronosyl glycosphingolipids in the pathogenesis of monoclonal IgM paraproteinemia and peripheral neuropathy

In IgM paraproteinemia and peripheral neuropathy, IgM M-protein secretion by B cells leads to a T helper cell response, suggesting that it is antibody-mediated autoimmune disease involving carbohydrate epitopes in myelin sheaths. An immune response against sulfoglucuronosyl glycosphingolipids (SGGLs) is presumed to participate in demyelination or axonal degeneration in the peripheral nervous system (PNS). SGGLs contain a 3-sulfoglucuronic acid residue that interacts with anti-myelin-associated glycoprotein (MAG) and the monoclonal antibody anti-HNK-1. Immunization of animals with sulfoglucuronosyl paragloboside (SGPG) induced anti-SGPG antibodies and sensory neuropathy, which closely resembles the human disease. These animal models might help to understand the disease mechanism and lead to more specific therapeutic strategies. In an in vitro study, destruction or malfunction of the blood-nerve barrier (BNB) was found, resulting in the leakage of circulating antibodies into the PNS parenchyma, which may be considered as the initial key step for development of disease

No evidence that protein truncating variants in BRIP1 are associated with breast cancer risk: implications for gene panel testing.

BACKGROUND: BRCA1 interacting protein C-terminal helicase 1 (BRIP1) is one of the Fanconi Anaemia Complementation (FANC) group family of DNA repair proteins. Biallelic mutations in BRIP1 are responsible for FANC group J, and previous studies have also suggested that rare protein truncating variants in BRIP1 are associated with an increased risk of breast cancer. These studies have led to inclusion of BRIP1 on targeted sequencing panels for breast cancer risk prediction. METHODS: We evaluated a truncating variant, p.Arg798Ter (rs137852986), and 10 missense variants of BRIP1, in 48 144 cases and 43 607 controls of European origin, drawn from 41 studies participating in the Breast Cancer Association Consortium (BCAC). Additionally, we sequenced the coding regions of BRIP1 in 13 213 cases and 5242 controls from the UK, 1313 cases and 1123 controls from three population-based studies as part of the Breast Cancer Family Registry, and 1853 familial cases and 2001 controls from Australia. RESULTS: The rare truncating allele of rs137852986 was observed in 23 cases and 18 controls in Europeans in BCAC (OR 1.09, 95% CI 0.58 to 2.03, p=0.79). Truncating variants were found in the sequencing studies in 34 cases (0.21%) and 19 controls (0.23%) (combined OR 0.90, 95% CI 0.48 to 1.70, p=0.75). CONCLUSIONS: These results suggest that truncating variants in BRIP1, and in particular p.Arg798Ter, are not associated with a substantial increase in breast cancer risk. Such observations have important implications for the reporting of results from breast cancer screening panels.The COGS project is funded through a European Commission's Seventh Framework Programme grant (agreement number 223175 - HEALTH-F2-2009-223175). BCAC is funded by Cancer Research UK [C1287/A10118, C1287/A12014] and by the European Community´s Seventh Framework Programme under grant agreement number 223175 (grant number HEALTH-F2-2009-223175) (COGS). Funding for the iCOGS infrastructure came from: the European Community's Seventh Framework Programme under grant agreement n° 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A 10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692, C8197/A16565), the National Institutes of Health (CA128978) and Post-Cancer GWAS initiative (1U19 CA148537, 1U19 16 CA148065 and 1U19 CA148112 - the GAME-ON initiative), the Department of Defense (W81XWH-10-1- 0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, Komen Foundation for the Cure, the Breast Cancer Research Foundation, and the Ovarian Cancer Research Fund. This study made use of data generated by the Wellcome Trust Case Control consortium. Funding for the project was provided by the Wellcome Trust under award 076113. The results published here are in part based upon data generated by The Cancer Genome Atlas Project established by the National Cancer Institute and National Human Genome Research Institute.This is the author accepted manuscript. The final version is available from BMJ Group at http://dx.doi.org/10.1136/jmedgenet-2015-103529

Tiques Ixodidae parasites d'oiseaux et leur rôle pathogène

The authors first give the list of Ixodid ticks which can be found on avian species in Europa and recall their pathogenic role for birds and mammals, when they are not specific, and, when they are, their eventual role as vectors or reservoir of germ for different kinds of infectious agents, more particularly for Borrelia burgdorferi, the agent of Lyme borreliosis. Concerning that zoonosis, the authors were mostly interested by the presence of B. burgdorferi in Ixodes (Trichotoixodes) pari Leach 1815 (= Ixodes frontalis (Panzer, 1798)), a very specific tick for birds; considered generally as a rare species, but in fact a very common one. Research of B. burgdorferi (sensu late) by indirect immunofluorescence revealed the presence of that agent in near 10 per cent of studied I. pari, including all evolutive stages and gorged states. Observation of B. burgdorferi in not yet fed larvae collected on the grass, with a non negligible frequency, results in the possible transmission of this infectious agent from infected female to its progeny, by transovarial passage. Existence of such a possibility let the authors think that I. pari is very likely a vector from bird to bird and a true germ reservoir for the zoonosis

Microbially-mediated glass dissolution and sorption of metals by Pseudomonas aeruginosa cells and biofilm.

A basaltic glass and a vitrified bottom ash were incubated at 25 degrees C in a growth medium (based on casaminoacids) inoculated with Pseudomonas aeruginosa. Bacterial growth and mineral concentrations in different compartments (bacterial cells, growth medium and biofilm) were monitored in short-term (3 days), and long-term experiments involving repeated renewals of the culture medium during 174 days. In short-term experiments, while the concentration of iron increased in the presence of bacteria, a decrease in Ni and Zn was observed in the growth medium compared to the sterile condition. During long-term experiments, such differences gradually decreased and disappeared after 78 days. On the contrary, iron concentration remained higher in the biotic condition compared to the sterile one. Bacterial growth resulted within a few days in the formation of a biofilm, which lead to the cementation of the altered glass grains. Most of the constituents of the glass (Si, Mg, Fe, Ti, Ba, Co, Zn, Cu, Ni and Cr) were found in the biofilm, while the chemical composition of the bacterial cells was very different

Fréquence de Borrelia burgdorferi, agent de la Borreliose de Lyme, chez les stades nymphaux de Ixodes ricinus (Acari: Ixodidae) dans divers massifs forestiers du centre de la France.

info:eu-repo/semantics/publishe

Action bactérienne sur un mâchefer d'incinération d'ordure ménagère

International audienceMicro-organisms such as bacteria are likely to be present in the weathered municipal solid waste incinerator (MSWI) bottom ash that will be used as aggregates in road construction. Microbial activity may impact the weathering process of such material and thus the rate of leaching of potentially toxic elements. Indeed, the deterioration of rocks, like that of materials of anthropogenic origin (stained glasses, cements, blast-furnace slags), depends partly on organic compounds and micro-organisms. However, the exact role of micro-organisms remains poorly understood. Some authors suggest that they play a considerable part in the degradation of stained glass in cathedrals but they do not specify neither the mechanisms, nor even the type of micro-organism (bacteria, fungi, lichens) involved. Other authors are of the opinion that bacteria accelerate the deterioration of marine basaltic glasses due to the observation of “hair channels” that could represent bacterial activity. In our opinion, the exact role of micro-organisms remains to be demonstrated apart for some well-defined materials: degradation of books by fungi and metal drains by bacteria like Thiobacillus. There is no existing experimental validation of the role of bacterial action in the degradation of complex silicates such as the glass contained in MSWI bottom ash. The major difficulty is to measure in such complex media the rate of deterioration with reliable tracers.Although studies have been conducted on the role of bacterial cells, there is however, a lack of studies that compare the degradation due to bacterial biofilms (cells-exopolymers-solution) and the degradation that occurs in abiotic systems. As a consequence, our aim was to investigate the effect of Pseudomonas aeruginosa (a common bacteria found in the environment) on the weathering of MSWI bottom slag under well-defined conditions, similar to the natural environment (neutral pH and 25 °C).Experiments were carried out at 25 °C for 19 weeks. Two conditions were performed in parallel; the first one in a sterile medium and the second one in the presence of P. aeruginosa. The culture medium used (PS medium AOUAD et al., 2005), buffered at pH 6.7, has been developed in order to detect the greatest number of elements dissolved during deterioration. The bottom slag grains were placed in containers filled with 50 ml of medium which was renewed each week to ensure the production of a measurable quantity of bacterial cells and exopolysaccharides (biofilm). The renewed solutions were analyzed using ICP/AES (Jobin-Yvon JY 124 spectrometer) and ICP/MS (Fisons VG PQ2 + spectrometer). From the measured concentrations for Si, Mg, Ca and Sr (potential tracers), the rate of dissolution expressed in masses standardized to the reactive surface area (g/m2.j) was calculated. Rates obtained in sterile condition are higher than those of the biotic one, but they converge by the end of the experiments. For Mg and Si the rates are lower than those obtained for Ca and Sr. This may be a consequence of the precipitation of a magnesium silicate hydrate.The first remarkable observation is that the grains leached in biotic medium are agglomerated and form a compact cluster whereas the grains resulting from deterioration in the abiotic medium remain free. SEM observations indicate that by the end of the experiments, the surface of the grains leached in abiotic medium do not appear to be different to those initially present. Conversely, grains deteriorated in biotic experiments are systematically covered with exopolyssacharides which explains their agglomeration; the biofilm cements the bottom ash grains together.The rate of corrosion of bottom ash decreases quickly in biotic medium despite of the renewal of the growth medium. One explanation could be that the biofilm acts as a protective barrier, thus preventing dissolution. The rate also decreases although less rapidly in the absence of bacteria. This is probably due to the formation of a layer of precipitated minerals at the surface which has also protective properties. At the end of our experiments (19 weeks) both rates are equal