Net-zooplankton abundance and biomass from Annaba Bay (SW Mediterranean Sea) under estuarine influences

Zooplankton samples were collected in Annaba Bay (Algeria) from January 2009-March 2011 at three coastal sites differently affected by estuarine plumes and external currents. Aim of this survey was to analyze zooplankton composition, abundance and biomass and compare the results with previous studies to reveal possible populations and environmental changes. The mean zooplankton abundance varied between 1,200-6,000 ind. m-3 and biomass 6.70-25.70 mg DW m-3, according to the site. Copepods constituted the main fraction of zooplankton community, and Oithona similis and Paracalanus indicus successively dominated during autumn-winter and spring-summer. The dinoflagellate Noctiluca scintillans was one of the major zooplankton components, and developed high numbers during February-April, becoming common in neritic and coastal regions. The singularity of the zooplankton from Annaba Bay is the prevalence of P. indicus throughout the entire bay and the decrease in Acartia discaudata and A. clausi (with respect to previous years), possibly replaced by A. negligens. Additionally, Oithona nana abundance markedly decreased with the large development of O. similis. Annaba Bay also differs from other similar Mediterranean coastal areas by the large development of Centropages ponticus populations during the warm period. Among the identified copepod species, the alien species Pseudodiaptomus australiensis and P. arabicus are reported for the first time in the Mediterranean Sea. The occurrence of copepodid V stages of P. australiensis suggests that this species survives and reproduces in Annaba Bay, but so far without developing an abundant population.

Nitrogen Source Differently Regulates Barley (Hordeum vulgare) Response to NaCl Stress At Seed Germination and Early Seedling Development Stages

Nitrogen (N) acts as nutrient and signaling molecule in plants all over their development stages. The involvement of various N forms in the regulation of seed germination response to salt stress was assessed in the present work. Nitrogen sources (NO, NO2−, NO3−, NH4+, glutamine and glutamate) were added at 1mMto the germination medium of barley (Hordeum vulgare, cv Ardhaoui) in combination or not with NaCl stress (14 g.L−1). The application of nitrogen monoxide (NO) alleviated by about 20% the NaCl-induced germination capacity decrease. However, the addition of ammonium ions (NH4+) and glutamic acid (Glu) accentuated the inhibitory effects of NaCl, decreasing germination capacity by about 50% compared to the control. The levels of malondialdehyde (MDA), which is an indicator of membrane lipid peroxidation by stresses, were increased by salinity in seeds treated with nitrite (NO2−), NO3−, Glu and Gln. In N-free medium, NaCl stress induced a severe nitrate reductase activity (NR, EC 1.6.1.6) inhibition. Such an effect was alleviated by the application of N treatments. Glutamate dehydrogenase (GDH, EC 1.4.1.2) aminating activity (NADH-GDH) of seedlings was inhibited by NaCl stress in the presence of NO, Glu and Gln. Conversely, there was stimulation by salt stress of NADH-GDH activity in seedlings treated with NaCl and NH4+. Deaminating GDH activity (NAD-GDH) was found to be enhanced by salt stress in NO2− and NO3− treatments. The differential effects of applied N forms on germination and early seedling development processes in this grass probably underlines different regulatory actions within N mobilization and assimilation

From Disease Association to Risk Assessment: An Optimistic View from Genome-Wide Association Studies on Type 1 Diabetes

Genome-wide association studies (GWAS) have been fruitful in identifying disease susceptibility loci for common and complex diseases. A remaining question is whether we can quantify individual disease risk based on genotype data, in order to facilitate personalized prevention and treatment for complex diseases. Previous studies have typically failed to achieve satisfactory performance, primarily due to the use of only a limited number of confirmed susceptibility loci. Here we propose that sophisticated machine-learning approaches with a large ensemble of markers may improve the performance of disease risk assessment. We applied a Support Vector Machine (SVM) algorithm on a GWAS dataset generated on the Affymetrix genotyping platform for type 1 diabetes (T1D) and optimized a risk assessment model with hundreds of markers. We subsequently tested this model on an independent Illumina-genotyped dataset with imputed genotypes (1,008 cases and 1,000 controls), as well as a separate Affymetrix-genotyped dataset (1,529 cases and 1,458 controls), resulting in area under ROC curve (AUC) of ∼0.84 in both datasets. In contrast, poor performance was achieved when limited to dozens of known susceptibility loci in the SVM model or logistic regression model. Our study suggests that improved disease risk assessment can be achieved by using algorithms that take into account interactions between a large ensemble of markers. We are optimistic that genotype-based disease risk assessment may be feasible for diseases where a notable proportion of the risk has already been captured by SNP arrays

Bladder perforation in a peritoneal dialysis patient

The dysfunction of the catheter in peritoneal dialysis (PD) is a frequent compli-cation. However, perforation of organs are rare, particularly that of the urinary bladder. This re-quires an early diagnosis and prompt treatment of patients. We report here the case of a 38-year-old woman having end-stage renal disease due to autosomal-dominant polycystic kidney disease treated by PD since November 2000. Three years later, she was treated for Staphylococcal peritonitis. Four months later, she presented with a severe urge to urinate at the time of the fluid exchanges. The biochemical analysis of the fluid from the bladder showed that it was dialysis fluid. Injection of contrast through the catheter demonstrated the presence of a fistula between the bladder and the peritoneal cavity. She underwent cystoscopic closure of the fistulous tract and the PD catheter was removed. Subsequently, the patient was treated by hemodialysis. One month later, a second catheter was implanted surgically after confirming the closure of the fistula. Ten days later, she presented with pain at the catheter site and along the tunnel, which was found to be swollen along its track. The injection of contrast produced swelling of the subcutaneous tunnel but without extravasation of the dye. PD was withdrawn and the patient was put back on hemodialysis. Bladder fistula is a rare complication in PD and diagnosis should be suspected when patient complains of an urge to pass urine during the exchanges, which can be confirmed by contrast study showing presence of dye in the bladder. PD may be possible after the closure of the fistula, but recurrence may occur