1,042 research outputs found
Episodes of falling among elderly people: a systematic review and meta-analysis of social and demographic pre-disposing characteristics
CONTEXT: The multifactorial nature of falls among elderly people is well-known. Identifying the social-demographic characteristics of elderly people who fall would enable us to define the typical profile of the elderly who are at risk of falling. OBJECTIVE: We aimed to isolate studies in which the social-demographic risk factors for falls among the elderly have been evaluated and to carry out a meta-analysis by combining the results of all of these selected studies. METHOD: We did a systematic literature review using the key words "accidental fall / numerical data" and "risk factors." Inclusion criteria entailed the selection of articles with the following characteristics: population of subjects aged 60 years or over, falls that took place in everyday life, and social-demographic risk factors for falls. RESULTS: 3,747 indexed articles published between 1981 and 2007 were identified, and 177 studies with available data were included, of which 129 had data on social-demographic risk factors for falls. Difficulties in activities of daily living (ADL) or in instrumental activities of daily living (IADL) double the risk of falling: The OR and 95% Cl were 2.26 (2.09, 2.45) for disturbance ADL and 2.10 (1.68, 2.64) for IADL. The OR and 95% Cl for Caucasians were 1.68 (0.98 - 2.88) and 0.64 (0.51 - 0.80) for Hispanics. In the subgroup of patients older than eighty, being married protected people from falling with an OR and 95% Cl =0.68 (0.53 - 0.87). CONCLUSION: Defining factors that create a risk of falling and protect elderly people from falls using social-demographic characteristics lets us focus on an "at risk" population for which a specific program could be developed
The FALCON concept: multi-object spectroscopy combined with MCAO in near-IR
A large fraction of the present-day stellar mass was formed between z=0.5 and
z~3 and our understanding of the formation mechanisms at work at these epochs
requires both high spatial and high spectral resolution: one shall
simultaneously} obtain images of objects with typical sizes as small as
1-2kpc(~0''.1), while achieving 20-50 km/s (R >= 5000) spectral resolution. The
obvious instrumental solution to adopt in order to tackle the science goal is
therefore a combination of multi-object 3D spectrograph with multi-conjugate
adaptive optics in large fields. A partial, but still competitive correction
shall be prefered, over a much wider field of view. This can be done by
estimating the turbulent volume from sets of natural guide stars, by optimizing
the correction to several and discrete small areas of few arcsec2 selected in a
large field (Nasmyth field of 25 arcmin) and by correcting up to the 6th, and
eventually, up to the 60th Zernike modes. Simulations on real extragalactic
fields, show that for most sources (>80%), the recovered resolution could reach
0".15-0".25 in the J and H bands. Detection of point-like objects is improved
by factors from 3 to >10, when compared with an instrument without adaptive
correction. The proposed instrument concept, FALCON, is equiped with deployable
mini-integral field units (IFUs), achieving spectral resolutions between R=5000
and 20000. Its multiplex capability, combined with high spatial and spectral
resolution characteristics, is a natural ground based complement to the next
generation of space telescopes.Comment: ESO Workshop Proceedings: Scientific Drivers for ESO Future VLT/VLTI
Instrumentation, 10 pages and 5 figure
Pancreatic tumours: molecular pathways implicated in ductal cancer are involved in ampullary but not in exocrine nonductal or endocrine tumorigenesis
Alterations of K-ras, p53, p16 and DPC4/Smad4 characterize pancreatic ductal cancer (PDC). Reports of inactivation of these latter two genes in pancreatic endocrine tumours (PET) suggest that common molecular pathways are involved in the tumorigenesis of pancreatic exocrine and endocrine epithelia. We characterized 112 primary pancreatic tumours for alterations in p16 and DPC4 and immunohistochemical expression of DPC4. The cases included 34 PDC, 10 intraductal papillary-mucinous tumours (IPMT), 6 acinar carcinomas (PAC), 5 solid-pseudopapillary tumours (SPT), 16 ampulla of Vater cancers (AVC) and 41 PET. All tumours were also presently or previously analysed for K- ras and p53 mutations and allelic loss at 9p, 17p and 18q. Alterations in K- ras, p53, p16 and DPC4 were found in 82%, 53%, 38% and 9% of PDC, respectively and in 47%, 60%, 25% and 6% of AVC. Alterations in these genes were virtually absent in PET, PAC or SPT, while in IPMT only K-ras mutations were present (30%). Positive immunostaining confirmed the absence of DPC4 alterations in all IPMT, SPT, PAC and PET, while 47% of PDC and 38% of AVC were immunonegative. These data suggest that pancreatic exocrine and endocrine tumourigenesis involves different genetic targets and that among exocrine pancreatic neoplasms, only ductal and ampullary cancers share common molecular events. © 2001 Cancer Research Campaign http://www.bjcancer.co
Purification and Reconstitution of the Glutamate Carrier GltT of the Thermophilic Bacterium Bacillus stearothermophilus
An affinity tag consisting of six adjacent histidine residues followed by an enterokinase cleavage site was genetically engineered at the N-terminus of the glutamate transport protein GltT of the thermophilic bacterium Bacillus stearothermophilus. The fusion protein was expressed in Escherichia coli and shown to transport glutamate. The highest levels of expression were observed in E. coli strain DH5α grown on rich medium. The protein could be purified in a single step by Ni2+-NTA affinity chromatography after solubilization of the cytoplasmic membranes with the detergent Triton X100. Purified GltT was reconstituted in an active state in liposomes prepared from E. coli phospholipids. The protein was reconstituted in detergent-treated preformed liposomes, followed by removal of the detergent with polystyrene beads. Active reconstitution was realized with a wide range of Triton X100 concentrations. Neither the presence of glycerol, phospholipids, nor substrates of the transporter was necessary during the purification and reconstitution procedure to keep the enzyme in an active state. In B. stearothermophilus, GltT translocates glutamate in symport with protons or sodium ions. In membrane vesicles derived from E. coli cells expressing GltT, the Na+ ion dependency seems to be lost, suggesting a role for the lipid environment in the cation specificity. In agreement with the last observation, glutamate transport catalyzed by purified GltT reconstituted in E. coli phospholipid is driven by an electrochemical gradient of H+ but not of Na+.
Cost-effectiveness analysis alongside the inter-B-NHL ritux 2010 trial:rituximab in children and adolescents with B cell non-Hodgkin’s lymphoma
Objectives: The randomized controlled trial Inter-B-NHL ritux 2010 showed overall survival (OS) benefit and event-free survival (EFS) benefit with the addition of rituximab to standard Lymphomes Malins B (LMB) chemotherapy in children and adolescents with high-risk, mature B cell non-Hodgkin’s lymphoma. Our aim was to assess the cost-effectiveness of rituximab-chemotherapy versus chemotherapy alone in the French setting.Methods: We used a decision-analytic semi-Markov model with four health states and 1-month cycles. Resource use was prospectively collected in the Inter-B-NHL ritux 2010 trial (NCT01516580). Transition probabilities were assessed from patient-level data from the trial (n = 328). In the base case analysis, direct medical costs from the French National Insurance Scheme and life-years (LYs) were computed in both arms over a 3-year time horizon. Incremental net monetary benefit and cost-effectiveness acceptability curve were computed through a probabilistic sensitivity analysis. Deterministic sensitivity analysis and several sensitivity analyses on key assumptions were also conducted, including one exploratory analysis with quality-adjusted life years as the health outcome.Results: OS and EFS benefits shown in the Inter-B-NHL ritux 2010 trial translated into the model by rituximab-chemotherapy being the most effective and also the least expensive strategy over the chemotherapy strategy. The mean difference in LYs between arms was 0.13 [95% CI 0.02; 0.25], and the mean cost difference € − 3 710 [95% CI € − 17,877; € 10,525] in favor of rituximab-chemotherapy group. For a € 50,000 per LY willingness-to-pay threshold, the probability of the rituximab-chemotherapy strategy being cost-effective was 91.1%. All sensitivity analyses confirmed these findings.Conclusion: Adding rituximab to LMB chemotherapy in children and adolescents with high-risk mature B-cell non-Hodgkin's lymphoma is highly cost-effective in France.Trial registration: ClinicalTrials.gov identifier: NCT01516580
Le mouflon de Corse
Synthèse des études disponibles sur le mouflon de Corse en France (Génétique population, répartition, particularités morphologiques, particularités physiologiques, pathologie, utilisation de l'espace, utilisation du temps,
alimentation, vie sociale, comportement reproducteur, relations interspécifiques, dynamique et structure des populations
Active Membrane Fluctuations Studied by Micropipet Aspiration
We present a detailed analysis of the micropipet experiments recently
reported in J-B. Manneville et al., Phys. Rev. Lett. 82, 4356--4359 (1999),
including a derivation of the expected behaviour of the membrane tension as a
function of the areal strain in the case of an active membrane, i.e.,
containing a nonequilibrium noise source. We give a general expression, which
takes into account the effect of active centers both directly on the membrane,
and on the embedding fluid dynamics, keeping track of the coupling between the
density of active centers and the membrane curvature. The data of the
micropipet experiments are well reproduced by the new expressions. In
particular, we show that a natural choice of the parameters quantifying the
strength of the active noise explains both the large amplitude of the observed
effects and its remarkable insensitivity to the active-center density in the
investigated range. [Submitted to Phys Rev E, 22 March 2001]Comment: 14 pages, 5 encapsulated Postscript figure
The ANTARES Optical Beacon System
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It
consists of a three dimensional array of photomultiplier tubes that can detect
the Cherenkov light induced by charged particles produced in the interactions
of neutrinos with the surrounding medium. High angular resolution can be
achieved, in particular when a muon is produced, provided that the Cherenkov
photons are detected with sufficient timing precision. Considerations of the
intrinsic time uncertainties stemming from the transit time spread in the
photomultiplier tubes and the mechanism of transmission of light in sea water
lead to the conclusion that a relative time accuracy of the order of 0.5 ns is
desirable. Accordingly, different time calibration systems have been developed
for the ANTARES telescope. In this article, a system based on Optical Beacons,
a set of external and well-controlled pulsed light sources located throughout
the detector, is described. This calibration system takes into account the
optical properties of sea water, which is used as the detection volume of the
ANTARES telescope. The design, tests, construction and first results of the two
types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.
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