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We compared the characteristics of neural cells derived from induced pluripotent stem (iPS) cells from a patient with multiple sclerosis versus neurally differentiated control iPS cells of a healthy individual. The iPS cells were differentiated toward the oligodendrocyte lineage using a four-step protocol established for the differentiation of embryonic stem cells. The resulting cell population was immunostained on day 112 of differentiation for the presence of oligodendrocytes and analyzed by transmission electron microscopy (TEM). Both patient and control samples resembled a mixed population of neural cells rather than oligodendroglia of high purity, including neural stem cell-like cells and possibly oligodendrocytes demonstrable by TEM.
Laboratory spectra showing Zeeman patterns in some FeH lines susceptible to be used as magnetic probes in cool stellar atmostpheres have been recorded in the laboratory, and molecular Landé factors obtained from analysis. These Landé factors have been used to model some lines recorded in Stokes V polarisation in sunspot spectra at the solar telescope THEMIS.
The effects of cyanobacterial toxins on herbivorous zooplankton depend on cyanobacterial strains, zooplankton species and environmental conditions. To explore the relationship between zooplankton and cyanobacteria, we investigated the effects of Planktothrix agardhii extracts on Daphnia magna population dynamics. We designed an experiment where individuals were grown in the presence of extracts of two P. agardhii strains. We monitored daily life-history parameters of D. magna individuals subjected to microcystin-RR (MC-RR), intracellular and extracellular extracts of a microcystin-producing strain (MC-strain, PMC 75.02) and a microcystin-free strain (MC-free strain, PMC 87.02) of P. agardhii. Measured life-history parameters of D. magna were used to build population dynamics models and compute expected population growth rate, replacement rate, generation time and proportion of adult and juveniles at demographic equilibrium. Results show that MC-RR tends to slow the life history (reduced growth rate and larger proportion of adults). In contrast, intracellular extracts of the two strains tend to accelerate the life history (increased growth rate, decreased generation time and lower proportion of adults). Extracellular extracts produce the same trends as the intracellular extracts but to a lesser extent. However, the MC-strain has stronger effects than the MC-free strain. Interestingly, extracellular extracts of the MC-free strain may have effects comparable to pure MC-RR. Moreover, in the presence of MC-RR and both cyanobacterial extracts, the daily fecundities present a cyclic pattern. These results suggest that MC-RR and unknown metabolites of cyanobacterial extracts have negative effects on D. magna reproduction processes such as those observed with endocrine-disruptive molecules.
Endemic to the island of Corsica in the western Mediterranean, the Corsican Nuthatch Sitta whiteheadi only occupies mature stands of Corsican Pine Pinus nigra laricio which cover a very small area. We present estimates of the distribution and population size of the Corsican Nuthatch, based on both field investigation and analysis of vegetation maps for the 103 county and municipality forests identified. Between spring 1997 and summer 2008, 48 forests were systematically investigated to map nuthatch territories, requiring 20 months of fieldwork. In the 55 forests not explored, we estimated the number of territories from analysis of digital maps with a calculated mean density from six spot-mapping censuses previously made in mature forests. The total estimated number was estimated to be 1,557-2,201 territories, distributed across 45 forest fragments (= group of connected stands) totalling 185 km2. At distances varying from 250 m to 16 km from each other, fragments were separated by unfavourable vegetation (shrubs, trees other than pines) or rocky outcrops. The area of these fragments varied from seven to 3,159 ha. Of the 45 fragments, 19 held fewer than 10 nuthatch pairs, 20 had 10–99 territories, and only six had more than 100 territories. We suggest that nuthatch numbers have declined by 10% in the past 10 years because of a reduction in suitable habitat due to fires and logging. The Corsican Nuthatch currently fulfils the criteria established by IUCN to qualify as “Vulnerable”.
Ce travail s’intéresse à un écoulement autour d’un obstacle cylindro-conique chauffé, en
rotation à l’intérieur d’une cavité cylindrique. Il s’agit d’étudier l’influence d’une
perturbation de type harmonique sur le comportement dynamique de l’écoulement et sur le
mécanisme de l’échange thermique avec l’obstacle. La fréquence de référence de
l’écoulement périodique a été déterminée par l’analyse de l’évolution du régime vers son
état stationnaire. L’étude a été menée pour des fréquences variant de 1/3 de la fréquence
de référence à 10 fois cette dernière. La périodicité de l’écoulement est assurée par la
condition d’entrée sur le débit supposé périodique. L’étude numérique a été réalisée pour
des valeurs du nombre de Reynolds inférieur à 100 et pour des valeurs de nombre de Taylor
inférieur à 500 afin d’éviter la présence des instabilités au sein de l’écoulement. Deux
méthodes numériques ont été utilisées : une méthode de différences-finies combinée avec un
schéma ADI et la méthode des éléments-finis. Le fluide considéré est l’air avec des
propriétés physiques constantes. Le couplage convection-conduction a été considéré dans
une plage de variation du rapport K de la conductivité thermique du
solide à celle du fluide de 10-2 à 103. Les résultats montrent que
les composantes de la vitesse varient en phase avec le débit, alors que la pression et les
différents paramètres thermiques sont en déphasage avec la vitesse d’entrée. On note aussi
l’aspect périodique de tous les paramètres dynamiques et thermiques de l’écoulement pour
les nombres de Reynolds utilisés. L’influence de la fréquence se manifeste davantage pour
ses valeurs élevées. Le nombre de Nusselt est proportionnel à la fréquence. Ces résultats
sont en bon accord avec ceux données par d’autres études de référence.
The strength of the association between intensive care unit (ICU)-acquired nosocomial infections (NIs) and mortality might differ according to the methodological approach taken.
TO assess the association between ICU-acquired NIs and mortality using the concept of population-attributable fraction (PAF) for patient deaths caused by ICU-acquired NIs in a large cohort of critically ill patients.
Eleven ICUs of a French university hospital.
We analyzed surveillance data on ICU-acquired NIs collected prospectively during the period from 1995 through 2003. The primary outcome was mortality from ICU-acquired NI stratified by site of infection. A matched-pair, case-control study was performed. Each patient who died before ICU discharge was defined as a case patient, and each patient who survived to ICU discharge was denned as a control patient. The PAF was calculated after adjustment for confounders by use of conditional logistic regression analysis.
Among 8,068 ICU patients, a total of 1,725 deceased patients were successfully matched with 1,725 control Patients. The adjusted PAF due to ICU-acquired NI for patients who died before ICU discharge was 14.6% (95% confidence interval [CI], 14.4%—14.8%). Stratified by the type of infection, the PAF was 6.1% (95% CI, 5.7%–6.5%) for pulmonary infection, 3.2% (95% CI, 2.8%–3.5%) for central venous catheter infection, 1.7% (95% CI, 0.9%–2.5%) for bloodstream infection, and 0.0% (95% CI, –0.4% to 0.4%) for urinary tract infection.
ICU-acquired NI had an important effect on mortality. However, the statistical association between ICU-acquired NI and mortality tended to be less pronounced in findings based on the PAF than in study findings based on estimates of relative risk. Therefore, the choice of methods does matter when the burden of NI needs to be assessed.
To describe the French program for the prevention of healthcare-associated infections and antibiotic resistance and provide results for some of the indicators available to evaluate the program. In addition to structures and process indicators, the 2 outcome indicators selected were the rate of surgical site infection and the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates among the S. aureus isolates recovered.
Descriptive study of the evolution of the national structures for control of healthcare-associated infections since 1992. Through national surveillance networks, process indicators were available from 1993 to 2006, surgical site infection rates were available from 1999 to 2005, and prevalence rates for MRSA infection were available from 2001 to 2007.
A comprehensive national program has gradually been set up in France during the period from 1993 to 2004, which included strengthening of organized infection control activities at the local, regional, and national levels and developing large networks for surveillance of specific infections and antibiotic resistance. These achievements were complemented by instituting mandatory notification for unusual nosocomial events, especially outbreaks. The second phase of the program involved the implementation of 5 national quality indicators with public reporting. Surgical site infection rates decreased by 25% over a 6-year period. In France, the median proportion of MRSA among S. aureus isolates recovered from patients with bacteremia decreased from 33.4% to 25.7% during the period from 2001 to 2007, whereas this proportion increased in many other European countries.
Very few national programs have been evaluated since the Study on the Efficacy of Nosocomial Infection Control. Although continuing efforts are required, the French program appears to have been effective at reducing infection rates.
We show that parasitism by the trematode Prosorhynchus squamatus in parental and introgressed Mytilus edulis/galloprovincialis (Bivalvia) mussels occurs in individuals with a predominantly M. edulis genome. This result suggests that the restricted specificity of P. squamatus is dependent on genetic factor(s) present in M. edulis. Because of its strong pathogenic effects (i.e. total castration and possible death), this parasite may be a source of intense selection against M. edulis genomes when they are present in a site. As a consequence, it may favour the geographic extension of the M. galloprovincialis genome. Previous studies have indicated that, in hybrid zones, recombinant genotypes are more susceptible to parasitic infections than either parental genotype. We demonstrate that this is not the case for the M. edulis/M. galloprovincialis system, and that the parental genotype alone determines susceptibility.
Introduction. The fruit of the date palm (Phoenix dactylifera L.) is an important crop of the arid and semi-arid areas of the world. It has always played a genuine economic and social part in the lives of the people of these areas. Nevertheless, there are few studies related to the composition and the functional properties of the different components (fibres, fats and proteins) of the date seeds. In order to obtain more information on the nutritive value and the chemical composition of the pits of the most important and most valuable Tunisian date palm varieties (Deglet Nour and Allig), we studied their profiles of proteins and amino acids. Materials and methods. Date seeds of two Tunisian cultivars, Deglet Nour and Allig, were separately milled in a heavy-duty grinder to pass 1–2 mm screens; then, they were preserved at – 20 °C until analysis. The soluble proteins from defatted date seeds were extracted with water at pH 10, and were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Results and discussion. Amino acid profiles revealed that date seeds from the Deglet Nour and Allig varieties contained the majority of essential amino acids: lysine, isoleucine, leucine, methionine, threonine, valine and phenylalanine. Seventeen amino acids were detected in the seeds of the two studied cultivars. Glutamic acid was the major amino acid in Deglet Nour and Allig date seeds, representing 17.83% and 16.77%, respectively, of the total amino acids. Date seeds appeared to contain a number of proteins with molecular weights ranging from 22 kDa to 70 kDa. Three prominent bands appeared at 32 kDa, 60 kDa and 70 kDa.
Les instabilités générées par frottement sont responsables
des divers bruits tels que le crissement, le sifflement ou le broutement... Pour modéliser et comprendre ce phénomène
d'instabilités, les analyses temporelles et aux valeurs propres sont
utilisées sur un système modèle constitué de deux poutres en
contact. Dans l'analyse aux valeurs propres, l'instabilité se manifeste
par la coalescence de deux modes propres du système. Dans l'analyse
temporelle, l'instabilité est caractérisée par des zones
d'adhérence ou de décollement qui apparaissent au niveau de la
surface de contact. Les résultats issus des deux analyses sont
cohérents et complémentaires. Une validation expérimentale a
été effectuée et montre une bonne corrélation entre les
résultats numériques et expérimentaux.
Although numerous environmental factors are documented to influence serum ascorbic concentrations, little is known about the genetic versus environmental contributions to variation of this trait. The aim of this study was to estimate family correlation and, additive genetic heritability and household effects in a variance component analysis for serum ascorbic acid concentrations. In a sample of ninety French families, information was obtained regarding serum ascorbic acid concentrations, usual dietary intake, lifestyle, and other related covariates. Spouse, parent–offspring and offspring–offspring significant correlation coefficients for serum ascorbic acid concentrations, adjusted for age, cigarette consumption and oral contraceptive use, were 0·432, 0·298 and 0·485, respectively, and for adjusted values for additional diet covariates (vitamin C intake and fruit and vegetable consumption), were 0·362, 0·154 and 0·348, respectively. Variance component analysis for serum ascorbic concentrations showed no significant genetic contribution to variability of this trait. Conversely, household common environment accounted for 27·7 and 42·6 % in parents and offspring, respectively, after adjustment for age, cigarette consumption and oral contraceptive use. After adjustment for the two additional diet covariates (vitamin C intake and fruit and vegetable consumption) household common variance decreased to 13·6 and 30·5 % in parents and offspring, respectively. These results show that serum ascorbic acid concentrations aggregate within healthy families partly due to diet intake but without a significant genetic component.
It is well known that the intestinal availability of Ca from Ca-rich mineral waters is equivalent to that of milk Ca. However, the effect of associated anions on Ca urinary loss needs to be addressed. The aim of the current study was to compare, under ordinary conditions of consumption, milk and a SO4-rich mineral water as the Ca provider in a large number of subjects consuming the same quantity of Ca from the two sources in a crossover study lasting for an extended period. Thirty-seven healthy women completed a 12-week protocol, divided into four periods of 3 weeks (W). In the first (W1–3) and third (W6–9) periods, dietary Ca intake was restricted to 600 mg/d. In the second (W4–6) and final (W10–12) periods, either 400 ml/d medium-fat milk or 1 litre of a Ca- and SO4-rich mineral water, each providing about 480 mg Ca/d, was added to the diet in a random manner. Dietary evaluation, blood and urinary measures were performed during the last week (W6 and W12) of each Ca supplementation period. The urinary excretion of Ca was higher (0·5 mmol/d more) with water than with milk (P<0·001). An examination of all the dietary factors known to influence calciuria suggested that the acidogenic action of SO4 was responsible for this increased calciuria. Thus, despite an equal Ca intake and assuming an unchanged intestinal absorption, these results suggest that Ca balance is better with milk consumption than with CaSO4-rich water.
Methods for assessing the occurrence and recency of mating are important for the management and conservation of exploited brachyuran crabs. Using multiparous females of the snow crab Chionoecetes opilio, we evaluated by experiment the efficacy of three indicators of recent mating: a white deposit in the spermathecae, extended mate-guarding, and fresh grasping marks on the female pereiopods. This was done by contrasting sperm counts between the left and the right spermatheca of females that were exposed to males with the right gonopod ablated, at treatment sex ratios of 20[female]:3[male ] or 50[female]:3[male ]. We expected that sperm reserves would be balanced between the two spermathecae of non-mated females and larger in the right than in the left spermatheca of mated females. Although no mating indicator was infallible, the presence of a white deposit was the most accurate because it maximized the median difference of sperm counts between the two spermathecae for the group of presumably mated females and minimized it for the group of presumably non-mated females. The use of grasping marks overestimated the mating frequency and resulted in the misclassification of a large proportion of females. Extended mate-guarding was a slightly better mating indicator than grasping marks, but it is not practical for field studies. Classification errors associated with each indicator can be explained mostly by female and male behaviours and may vary in magnitude with sociosexual context.
Minke whale (Balaenoptera acutorostrata) distribution was derived from a 12 year observation programme in the Mingan Islands (Canada) and related to three geological features of the sea-floor: maximum depth, topography and geomorphology. Minke whale distribution was not uniform nor random in relation to maximum depth and topography, however, no evident trend was found. The most prominent factor was the presence of underwater sand dunes, where significantly more minke whales were observed than on any other bottom types. Because sand dunes are the favoured habitat of the minke whale major prey in the study area, an indirect link between minke whale distribution, geomorphology and substrate type is suggested.
Digestion and portal net flux of nutrients were studied in sheep fed twice daily with fresh orchard-grass. Digestive flows were measured in six fistulated sheep using the double-marker technique. Three sheep were fitted with catheters and blood-flow probes, allowing nutrient net flux measurements across the portal-drained viscera (PDV), the mesenteric-drained viscera (MDV) and the rumen. Total tract apparent digestion of N was similar to portal net appearance of N, calculated as the sum of free amino acids (FAA), peptide amino acids (PAA), NH3, and urea net fluxes. PAA accounted for 25 % of non-protein amino acid net release across the PDV. With the exception of glycine and glutamate, the small intestine was the main contributor to this PAA net release. The essential amino acid (EAA) apparent disappearance between the duodenum and the ileum was lower than the net appearance of EAA (FAA + PAA) across the MDV. The value of PDV:MDV flux of free EAA was, on average, 78 %. The rumen accounted for 30 % of the net uptake of EAA by the PDV tissues not drained by the mesenteric vein. Rumen net release of acetate, propionate, butyrate, 3-hydroxybutyrate, and lactate accounted for 70, 55, 46, 77 and 52 %, respectively, of their portal net releases. Conversely, the small intestine was a net consumer of arterial acetate and 3-hydroxybutyrate. Dynamic study of nutrient net fluxes across the PDV showed that throughout a feeding cycle, the liver faced a constant flux of amino acids (AA), whereas volatile fatty acid and NH3 net fluxes varied in response to the meal. The present study specified, in forage-fed sheep, the partitioning of nutrient net fluxes across the PDV and the role of peptides in portal net release of AA.
The production of laccase, an enzyme of industrial interest, was screened among species of the genus Pycnoporus, in particular P. sanguineus. Strains were isolated from various tropical Chinese environments and phylogenetically compared to ones deposited in international collections. Molecular clustering, based on ribosomal ITS1-5.8S-ITS2 genomic sequence analysis, showed that the Chinese strains of P. sanguineus formed an homogeneous phylogenetic group distinguished by its laccase-overproducing character. The dikaryotic strain P. sanguineus G05 was selected for its ability to produce up to 40 000 U l−1 laccase in the presence of 2,5-xylidine, Tween 80 and maize bran. Since fruit bodies of P. sanguineus could be formed in the laboratory, monokaryotic laccase-hyperproducing strains were isolated using classic genetical methods. Among these isolates, strain G05.10 synthesized up to 71 000 U l−1 laccase, with a productivity of 5069 U l−1 d−1. The laccase was purified and identified as a 70 kDa protein with an acidic pI, and was very stable at high temperatures.
Current evidence strongly supports a role for the breast tumour suppressor genes, BRCA1 and BRCA2, in both normal development and carcinogenesis. In vitro observations reported that BRCA1 and BRCA2 are expressed in a cell cycle-dependent manner. Interestingly, differences in the actions of n-3 and n-6 polyunsaturated fatty acids have been observed: while the n-3 polyunsaturated fatty acids have been described to reduce pathological cell growth, the n-6 polyunsaturated fatty acids have been found to induce tumour proliferation. Here, we examined the expression of BRCA1 and BRCA2 in breast cell lines after treatment with polyunsaturated fatty acids. Real-time quantitative polymerase chain reaction determinations conclusively demonstrated increases in BRCA1 and BRCA2 mRNA expressions in MCF7 and MDA-MB 231 tumour cell lines after treatment with n-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but no variation was noticed with the n-6 polyunsaturated fatty acid (arachidonic acid). On the other hand, no variation of the expression of BRCA1 and BRCA2 mRNA was detected in MCF10a normal breast cell line treated by polyunsaturated fatty acids. The level of BRCA1 and BRCA2 proteins quantified by affinity chromatography remained unchanged in tumour (MCF7, MDA-MB 231) and normal (MCF10a) breast cell lines. We suggest the presence of a possible transcriptional or post-transcriptional regulation of BRCA1 and BRCA2 after n-3 polyunsaturated fatty acid treatment in breast tumour cells.
To identify the routes of transmission in a nosocomial outbreak of hepatitis C virus (HCV) infection.
Epidemiological investigation, including screening for HCV of hospitalized patients, and a retrospective cohort study, review of hygiene and medical practices, and molecular comparison of HCV isolates.
A specialized care unit for cystic fibrosis (CF) and diabetic patients at an acute-care facility in the south of France.
Of the 57 CF patients (age in 1995: 2-28 years), 38 (66.7%) were tested and 22 (57.9%) were anti-HCV positive. Eight (50%) of 16 patients with anti-HCV antibody tested by polymerase chain reaction were viremic. No patients had received blood products or had any history of intravenous drug use. All 18 (100%) patients with CF who had ever undergone self-monitoring of capillary blood glucose in the unit were anti-HCV positive, compared to 4 (20%) of 20 who had not (relative risk, 5.0; 95% confidence interval, 2.1-12.0). Seventy (39.5%) of the patients with diabetes were screened for anti-HCV; 12 (18.8%) tested positive, with 3 (25%) positive for HCV-RNA. Patients with diabetes had routine capillary blood glucose monitoring while hospitalized and shared with CF patients the same spring-triggered devices for capillary blood glucose monitoring. The disposable platform of the devices was not changed between patient use. All HCV isolates belonged to the type 1, subtype b, and phylogenetic analysis showed a close homology by sequencing of NS5b and E2/HVR regions.
As reported earlier for the hepatitis B virus, shared spring-triggered devices for capillary blood glucose monitoring by finger puncture may transmit HCV. Strict application of Standard Precautions procedures is warranted in any healthcare setting.