A Virtual CAD Model of the LHC

Integrating the large and complex LHC machine into the existing LEP tunnel is a major challenge. Space was not really a problem to fit the LEP machine into its tunnel, but LHC cryostats are much larger than the LEP quadrupoles and the external cryogenic line fills even more the tunnel. Space problems lead to small clearances. Possible conflicts, or at least the most penalising ones, between installed equipment or with transport, must be solved beforehand in order to avoid unacceptable delays and extra costs during the installation. Experience gained with LEP has already shown the help that Computer-Aided Engineering tools could provide for the integration. A virtual model of the LHC is presently prepared. The actual LEP tunnel, known with a quite good accuracy (centimetre level), has been modelled and all the elements of the machine constructed as 3D objects with the CAD system are positioned accurately on the basis of data generated from the theoretical definition. These layouts are used to generate the reference sections and to check the clearances. Examples of this powerful approach applied to engineering for accelerators are given

Rhizobial characterization in revegetated areas after bauxite mining.

Little is known regarding how the increased diversity of nitrogen-fixing bacteria contributesto the productivity and diversity of plants in complex communities. However, some authorshave shown that the presence of a diverse group of nodulating bacteria is required for dif-ferent plant species to coexist. A better understanding of the plant symbiotic organismdiversity role in natural ecosystems can be extremely useful to define recovery strategies ofenvironments that were degraded by human activities. This study used ARDRA, BOX-PCRfingerprinting and sequencing of the 16S rDNA gene to assess the diversity of root nodulenitrogen-fixing bacteria in former bauxite mining areas that were replanted in 1981, 1985,1993, 1998, 2004 and 2006 and in a native forest. Among the 12 isolates for which the 16SrDNA gene was partially sequenced, eight, three and one isolate(s) presented similarity withsequences of the genera Bradyrhizobium, Rhizobium and Mesorhizobium, respectively. The rich-ness, Shannon and evenness indices were the highest in the area that was replanted theearliest (1981) and the lowest in the area that was replanted most recently (2006)

Role of methylotrophy during symbiosis between Methylobacterium nodulans and Crotalaria podocarpa

Some rare leguminous plants of the genus Crotalaria are specifically nodulated by the methylotrophic bacterium Methylobacterium nodulans. In this study, the expression and role of bacterial methylotrophy were investigated during symbiosis between M. nodulans, strain ORS 2060(T), and its host legume, Crotalaria podocarpa. Using lacZ fusion to the mxaF gene, we showed that the methylotroph genes are expressed in the root nodules, suggesting methylotrophic activity during symbiosis. In addition, loss of the bacterial methylotrophic function significantly affected plant development. Indeed, inoculation of M. nodulans nonmethylotroph mutants in C. podocarpa decreased the total root nodule number per plant up to 60%, decreased the whole-plant nitrogen fixation capacity up to 42%, and reduced the total dry plant biomass up to 46% compared with the wild-type strain. In contrast, inoculation of the legume C. podocarpa with nonmethylotrophic mutants complemented with functional mxa genes restored the symbiotic wild phenotype. These results demonstrate the key role of methylotrophy during symbiosis between M. nodulans and C. podocarpa

Arbuscular mycorrhizal fungi diversity in revegetated areas after bauxite mining.

Arbuscular mycorrhizal fungi (AMF) are obligatory biotrophs that have a symbiotic evolutionary relationship with about 80% of all terrestrial plant species. The fungus mainly supplies water and nutrients to the plant and receives photoassimilates. The AMF diversity affects both the competition among species and floristic composition of an area. Fluctuations in the population of this group of microorganisms can cause fluctuations in plant populations above ground. In this work, the AMF community profile in areas with different ages of revegetation was evaluated by morphological identification of spores and denaturing gradient gel electrophoresis (DGGE) techniques. We found 12 AMF species and dominance of the species Glomus macrocarpum determined by spore density. Since the richness level observed in each plot was low and there was predominance of one species of AMF, it can be concluded that these areas still present a high degree of disturbance. It was possible to detect complex band profiles by DGGE analyses for the two plant species studied, Visnia latifolia and Cecropia hololeuca. No relationship between AMF diversity and revegetation time was observed in these areas

ICU Risk Stratification Models Feasible for Use in Sub-Saharan Africa Show Poor Discrimination in Malawi: A Prospective Cohort Study

Background: Critical illness disproportionately affects people in low-income countries (LICs). Efforts to improve critical care in LICs must account for differences in demographics and infrastructure compared to high-income settings. Part of this effort includes the development and validation of intensive care unit (ICU) risk stratification models feasible for use in LICs. The purpose of this study was to validate and compare the performance of ICU mortality models developed for use in sub-Saharan Africa. Materials and Methods: This was a prospective, observational cohort study of ICU patients in a referral hospital in Malawi. Models were selected for comparison based on a Medline search for studies which developed ICU mortality models based on cohorts in sub-Saharan Africa. Model discrimination was evaluated using the area under the curve with 95% confidence intervals (CI). Results: During the study, 499 patients were admitted to the study ICU, and after exclusions, there were 319 patients. The cohort was 62% female, with the mean age 31 years (IQR: 23-41), and 74% had surgery preceding ICU admission. Discrimination for hospital mortality ranged from 0.54 (95% CI 0.48, 0.60) for the Universal Vital Assessment (UVA) to 0.72 (95% CI 0.66, 0.78) for the Malawi Intensive care Mortality Evaluation (MIME). After tenfold cross-validation, these results were unchanged. Conclusions: The MIME outperformed other models in this prospective study. Most ICU models developed for LICs had poor to modest discrimination for hospital mortality. Future research may contribute to a better risk stratification model for LICs by refining and enhancing the MIME

Serological proteome analysis reveals new specific biases in the IgM and IgG autoantibody repertoires in autoimmune polyendocrine syndrome type 1

Objective: Autoimmune polyendocrine syndrome type 1 (APS 1) is caused by mutations in the AIRE gene that induce intrathymic T-cell tolerance breakdown, which results in tissue-specific autoimmune diseases. Design: To evaluate the effect of a well-defined T-cell repertoire impairment on humoral self-reactive fingerprints, comparative serum self-IgG and self-IgM reactivities were analyzed using both one- and two-dimensional western blotting approaches against a broad spectrum of peripheral tissue antigens. Methods: Autoantibody patterns of APS 1 patients were compared with those of subjects affected by other autoimmune endocrinopathies (OAE) and healthy controls. Results: Using a Chi-square test, significant changes in the Ab repertoire were found when intergroup patterns were compared. A singular distortion of both serum self-IgG and self-IgM repertoires was noted in APS 1 patients. The molecular characterization of these antigenic targets was conducted using a proteomic approach. In this context, autoantibodies recognized more significantly either tissue-specific antigens, such as pancreatic amylase, pancreatic triacylglycerol lipase and pancreatic regenerating protein 1α, or widely distributed antigens, such as peroxiredoxin-2, heat shock cognate 71-kDa protein and aldose reductase. As expected, a well-defined self-reactive T-cell repertoire impairment, as described in APS 1 patients, affected the tissue-specific self-IgG repertoire. Interestingly, discriminant IgM reactivities targeting both tissue-specific and more widely expressed antigens were also specifically observed in APS 1 patients. Using recombinant targets, we observed that post translational modifications of these specific antigens impacted upon their recognition. Conclusions: The data suggest that T-cell-dependent but also T-cell-independent mechanisms are involved in the dynamic evolution of autoimmunity in APS 1

Development of a Malawi Intensive care Mortality risk Evaluation (MIME) model, a prospective cohort study

Introduction: Intensive care medicine can contribute to population health in low-income countries by reducing premature mortality related to surgery, trauma, obstetrical and other medical emergencies. Quality improvement is guided by risk stratification models, which are developed primarily within high-income settings. Models validated for use in low-income countries are needed. Methods: This prospective cohort study consisted of 261 patients admitted to the intensive care unit (ICU) of Kamuzu Central Hospital in Malawi, from September 2016 to March 2018. The primary outcome was in-hospital mortality. We performed univariable analyses on putative predictors and included those with a significance of 0.15 in the Malawi Intensive care Mortality risk Evaluation model (MIME). Model discrimination was evaluated using the area under the curve. Results: Males made up 37.9% of the study sample and the mean age was 34.4 years. A majority (73.9%) were admitted to the ICU after a recent surgical procedure, and 59% came directly from the operating theater. In-hospital mortality was 60.5%. The MIME based on age, sex, admitting service, systolic pressure, altered mental status, and fever during the ICU course had a fairly good discrimination, with an AUC of 0.70 (95% CI 0.63–0.76). Conclusions: The MIME has modest ability to predict in-hospital mortality in a Malawian ICU. Multicenter research is needed to validate the MIME and assess its clinical utility