620 research outputs found

    An examination of the temporal and geographical patterns of psychiatric emergency service use by multiple visit patients as a means for their early detection

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    <p>Abstract</p> <p>Background:</p> <p>Frequent users of the psychiatric emergency service (PES) place a heavy burden upon the mental health care delivery system. The aim of this study was to identify distinct temporal or geographical patterns of PES use by these patients as potential markers for their early detection.</p> <p>Methods:</p> <p>Diagnostic profiles were obtained for patients making an intermediate (4 to 10) or a high (11 or more) number of visits to a general hospital PES in Montreal (Canada) between 1985 and 2004. Between-group comparisons were made with regards to several parameters. These included the time intervals between consecutive visits, visit clustering (single, repeating, and the time interval to the first cluster) and visits made to three other services where data was similarly acquired from 2002 to 2004.</p> <p>Results:</p> <p>The two multiple visit groups differed with regards to diagnostic profiles and actual time between consecutive visits (significantly shorter in patients with 11 or more visits). Patients with 11 or more visits were more likely to have a single cluster (3 or more visits/3 months) or repeating clusters (4 visits/3 months) in their patterns of use. Personality disorders were more prevalent in patients with single clusters as they were, along with schizophrenia, in those with repeating clusters. In addition, clusters were found to occur sufficiently early so as to be potentially useful as markers for early detection. Ten percent of those with 11 or more visits and 16% of those with an intermediate number of visits frequented at least one other PES. A small number of patients, primarily those with substance abuse, made over 50% of their visits to other services.</p> <p>Conclusion:</p> <p>Temporal and geographical patterns of use differed significantly between the multiple visit groups. These patterns, combined with distinct diagnostic profiles, could potentially lead to the more rapid identification and treatment of specific sub-groups of multiple visit patients.</p

    Effect of chromophore-chromophore electrostatic interactions in the NLO response of functionalized organic-inorganic sol-gel materials

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    In the last years, important non-linear optical results on sol-gel and polymeric materials have been reported, with values comparable to those found in crystals. These new materials contain push-pull chromophores either incorporated as guest in a high Tg polymeric matrix (doped polymers) or grafted onto the polymeric matrix. These systems present several advantages; however they require significant improvement at the molecular level - by designing optimized chromophores with very large molecular figure of merit, specific to each application targeted. Besides, it was recently stated in polymers that the chromophore-chromophore electrostatic interactions, which are dependent of chromophore concentration, have a strong effect into their non-linear optical properties. This has not been explored at all in sol-gel systems. In this work, the sol-gel route was used to prepare hybrid organic-inorganic thin films with different NLO chromophores grafted into the skeleton matrix. Combining a molecular engineering strategy for getting a larger molecular figure of merit and by controlling the intermolecular dipole-dipole interactions through both: the tuning of the push-pull chromophore concentration and the control of TEOS (Tetraethoxysilane) concentration, we have obtained a r33 coefficient around 15 pm/V at 633 nm for the classical DR1 azo-chromophore and a r33 around 50 pm/V at 831 nm for a new optimized chromophore structure.Comment: 10 pages, 11 figures, 1 tabl

    Giant alkali-metal-induced lattice relaxation as the driving force of the insulating phase of alkali-metal/Si(111):B

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    Ab initio density-functional theory calculations, photoemission spectroscopy (PES), scanning tunneling microscopy, and spectroscopy (STM, STS) have been used to solve the 2√3 x 2√3R30 surface reconstruction observed previously by LEED on 0.5 ML K/Si:B. A large K-induced vertical lattice relaxation occurring only for 3/4 of Si adatoms is shown to quantitatively explain both the chemical shift of 1.14 eV and the ratio 1/3 measured on the two distinct B 1s core levels. A gap is observed between valence and conduction surface bands by ARPES and STS which is shown to have mainly a Si-B character. Finally, the calculated STM images agree with our experimental results. This work solves the controversy about the origin of the insulating ground state of alkali-metal/Si(111):B semiconducting interfaces which were believed previously to be related to many-body effectsThis work has received the financial support of the French ANR SURMOTT program (ANR-09-BLAN- 0210-01) and the Spanish MICIIN under Project No. FIS2010-1604

    Distribution-based bisimulation for labelled Markov processes

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    In this paper we propose a (sub)distribution-based bisimulation for labelled Markov processes and compare it with earlier definitions of state and event bisimulation, which both only compare states. In contrast to those state-based bisimulations, our distribution bisimulation is weaker, but corresponds more closely to linear properties. We construct a logic and a metric to describe our distribution bisimulation and discuss linearity, continuity and compositional properties.Comment: Accepted by FORMATS 201

    The elderly in the psychiatric emergency service (PES); a descriptive study

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    <p>Abstract</p> <p>Background</p> <p>The impact of an aging population on the psychiatric emergency service (PES) has not been fully ascertained. Cognitive dysfunctions aside, many DSM-IV disorders may have a lower prevalence in the elderly, who appear to be underrepresented in the PES. We therefore attempted to more precisely assess their patterns of PES use and their clinical and demographic characteristics.</p> <p>Methods</p> <p>Close to 30,000 visits to a general hospital PES (Montreal, Quebec, Canada) were acquired between 1990 and 2004 and pooled with over 17,000 visits acquired using the same methodology at three other services in Quebec between 2002 and 2004.</p> <p>Results</p> <p>The median age of PES patients increased over time. However, the proportion of yearly visits attributable to the elderly (compared to those under 65) showed no consistent increase during the observation period. The pattern of return visits (two to three, four to ten, eleven or more) did not differ from that of patients under 65, although the latter made a greater number of total return visits per patient. The elderly were more often women (62%), widowed (28%), came to the PES accompanied (42%) and reported « illness » as an important stressor (29%). About 39% were referred for depression or anxiety. They were less violent (10%) upon their arrival. Affective disorders predominated in the diagnostic profile, they were less co-morbid and more likely admitted than patients under 65.</p> <p>Conclusion</p> <p>Although no proportional increase in PES use over time was found the elderly do possess distinct characteristics potentially useful in PES resource planning so as to better serve this increasingly important segment of the general population.</p

    Energy Spectra, Altitude Profiles and Charge Ratios of Atmospheric Muons

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    We present a new measurement of air shower muons made during atmospheric ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio mu+ / mu- is presented as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c. The differential mu- momentum spectra are presented between 0.3 and about 50 GeV/c at atmospheric depths between 13 and 960 g/cm^2. We compare our measurements with other recent data and with Monte Carlo calculations of the same type as those used in predicting atmospheric neutrino fluxes. We find that our measured mu- fluxes are smaller than the predictions by as much as 70% at shallow atmospheric depths, by about 20% at the depth of shower maximum, and are in good agreement with the predictions at greater depths. We explore the consequences of this on the question of atmospheric neutrino production.Comment: 11 pages, 8 figures, to appear in Phys. Rev. D (2000

    Extraction of hydrocarbons from freshwater green microalgae (Botryococcus sp.) biomass after phycoremediation of domestic wastewater

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    This study was undertaken to analyze the efficiency of Botryococcus sp. in the phycoremediation of domestic wastewater and to determine the variety of hydrocarbons derived from microalgal oil after phycoremediation. The study showed a significant (p < 0.05) reduction of pollutant loads of up to 93.9% chemical oxygen demand, 69.1% biochemical oxygen demand, 59.9% total nitrogen, 54.5% total organic carbon, and 36.8%phosphate. The average dry weight biomass produce was 0.1 g/L of wastewater. In addition, the dry weight biomass of Botryococcus sp. was found to contain 72.5% of crude oil. The composition analysis using Gas Chromatogram - Mass Spectrometry (GC-MS) found that phthalic acid, 2-ethylhexyltridecyl ester (C29H48O4), contributed the highest percentage (71.6%) of the total hydrocarbon compounds to the extracted algae oil. The result of the study suggests that Botryococcus sp. can be used for effective phycoremediation, as well as to provide a sustainable hydrocarbon source as a value-added chemical for the bio-based plastic industry

    Microparticle-mediated transfer of the viral receptors CAR and CD46, and the CFTR channel in a CHO cell model confers new functions to target cells

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    Cell microparticles (MPs) released in the extracellular milieu can embark plasma membrane and intracellular components which are specific of their cellular origin, and transfer them to target cells. The MP-mediated, cell-to-cell transfer of three human membrane glycoproteins of different degrees of complexity was investigated in the present study, using a CHO cell model system. We first tested the delivery of CAR and CD46, two monospanins which act as adenovirus receptors, to target CHO cells. CHO cells lack CAR and CD46, high affinity receptors for human adenovirus serotype 5 (HAdV5), and serotype 35 (HAdV35), respectively. We found that MPs derived from CHO cells (MP-donor cells) constitutively expressing CAR (MP-CAR) or CD46 (MP-CD46) were able to transfer CAR and CD46 to target CHO cells, and conferred selective permissiveness to HAdV5 and HAdV35. In addition, target CHO cells incubated with MP-CD46 acquired the CD46-associated function in complement regulation. We also explored the MP-mediated delivery of a dodecaspanin membrane glycoprotein, the CFTR to target CHO cells. CFTR functions as a chloride channel in human cells and is implicated in the genetic disease cystic fibrosis. Target CHO cells incubated with MPs produced by CHO cells constitutively expressing GFP-tagged CFTR (MP-GFP-CFTR) were found to gain a new cellular function, the chloride channel activity associated to CFTR. Time-course analysis of the appearance of GFP-CFTR in target cells suggested that MPs could achieve the delivery of CFTR to target cells via two mechanisms: the transfer of mature, membrane-inserted CFTR glycoprotein, and the transfer of CFTR-encoding mRNA. These results confirmed that cell-derived MPs represent a new class of promising therapeutic vehicles for the delivery of bioactive macromolecules, proteins or mRNAs, the latter exerting the desired therapeutic effect in target cells via de novo synthesis of their encoded proteins
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