1,440 research outputs found

    Settlement of Macoma balthica larvae in response to benthic diatom films

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    The role of multi-species benthic diatom films (BDF) in the settlement of late pediveliger larvae of the bivalve Macoma balthica was investigated in still-water bioassays and multiple choice flume experiments. Axenic diatom cultures that were isolated from a tidal mudflat inhabited by M. balthica were selected to develop BDF sediment treatments characterized by a different community structure, biomass, and amount of extracellular polymeric substances (EPS). Control sediments had no added diatoms. Although all larvae settled and initiated burrowing within the first minute after their addition in still water, regardless of treatment, only 48-52% had completely penetrated the high diatom biomass treatments after 5 min, while on average 80 and 69% of the larvae had settled and burrowed into the control sediments and BDF with a low diatom biomass (<3.5 mu g Chl a g(-1) dry sediment), respectively. The percentage of larvae settling and burrowing into the sediment was negatively correlated with the concentration of Chl a and EPS of the BDF. This suggests higher physical resistance to bivalve penetration by the BDF with higher diatom biomass and more associated sugar and protein compounds. The larval settlement rate in annular flume experiments at flow velocities of 5 and 15 cm s(-1) was distinctly lower compared to the still-water assays. Only 4.6-5.8% of the larvae were recovered from BDF and control sediments after 3 h. Nonetheless, a clear settlement preference was observed for BDF in the flume experiments; i.e., larvae settled significantly more in BDF compared to control sediments irrespective of flow speed. Comparison with the settlement of polystyrene mimics and freeze-killed larvae led to the conclusion that active selection, active secondary dispersal and, at low flow velocities (5 cm s(-1)), passive adhesion to the sediment are important mechanisms determining the settlement of M. balthica larvae in estuarine biofilms

    The long-term effect of complex regional pain syndrome type 1 on disability and quality of life after foot injury

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    PURPOSE: To study the long-term evolution of patients with lower-limb Complex Regional Pain Syndrome (CRPS), focusing on functional and proprioceptive aspects and quality of life. METHODS: In 20 patients suffering from chronic distal lower-limb CRPS diagnosed using Budapest criteria, we assessed joint position sense and strength of the knee muscles at the CRPS and unaffected leg, functional exercise capacity, pain, CRPS severity score, quality of life and kinesiophobia. Similar assessments were performed in 20 age-matched controls. RESULTS: The joint position performance (at 45°) was significantly lower for the CRPS leg as compared to controls. The knee extensor strength of the CRPS leg was significantly reduced as compared to the unaffected leg (−27%) and controls (−42%). CRPS patients showed significantly reduced performance at the 6 min-walk test as compared to their age group predicted value and controls. Patients suffering from CRPS for 3.8 years in average still exhibit high pain, severity and kinesiophobia scores. CONCLUSIONS: Long-term deficits in strength and proprioceptive impairments are observed at the knee joint of the CRPS leg. This persistent functional disability has significant repercussions on the quality of life. We highlight the importance of including strength and proprioceptive exercises in the therapeutic approaches for CPRS patients

    Antineutrino emission and gamma background characteristics from a thermal research reactor

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    The detailed understanding of the antineutrino emission from research reactors is mandatory for any high sensitivity experiments either for fundamental or applied neutrino physics, as well as a good control of the gamma and neutron backgrounds induced by the reactor operation. In this article, the antineutrino emission associated to a thermal research reactor: the OSIRIS reactor located in Saclay, France, is computed in a first part. The calculation is performed with the summation method, which sums all the contributions of the beta decay branches of the fission products, coupled for the first time with a complete core model of the OSIRIS reactor core. The MCNP Utility for Reactor Evolution code was used, allowing to take into account the contributions of all beta decayers in-core. This calculation is representative of the isotopic contributions to the antineutrino flux which can be found at research reactors with a standard 19.75\% enrichment in 235^{235}U. In addition, the required off-equilibrium corrections to be applied to converted antineutrino energy spectra of uranium and plutonium isotopes are provided. In a second part, the gamma energy spectrum emitted at the core level is provided and could be used as an input in the simulation of any reactor antineutrino detector installed at such research facilities. Furthermore, a simulation of the core surrounded by the pool and the concrete shielding of the reactor has been developed in order to propagate the emitted gamma rays and neutrons from the core. The origin of these gamma rays and neutrons is discussed and the associated energy spectrum of the photons transported after the concrete walls is displayed.Comment: 14 pages, 11 figures, Data in Appendix A and B (13 pages

    Fluorescence excitation spectrum, lifetimes and photoisomerization of jet-cooled conformers of 1,1 '- bi(benzocyclobutylidene)

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    First measurements of fluorescence excitation spectra of the recently synthesized rigid stilbene analogue 1,1'- bi(benzocyclobutylidene) in a supersonic jet expansion show that, in contrast to the parent compound, both the trans- and the cis-conformer fluoresce under these conditions. The excitation energy dependence of fluorescence lifetimes indicates the onset of an efficient non-radiative decay channel above energy thresholds of 1340 cm(-1) and 990 cm(-1) for the trans- and cis-form, respectively, which is assigned to photoisomerization in the singlet state. From an RRKM analysis of the microcanonical rate coefficients an estimate of the high pressure limit of the thermal photoisomerization rate coefficient is obtained and compared with photoisomerization rate coefficients measured in low viscosity solution and in thermal vapor. There are strong indications that for this compound there are no dynamic or static solvent induced effects that lead to an anomalous acceleration of the reaction in solution

    Retrospective analysis of a cohort of HIV-infected patients on antiretroviral therapy in Abidjan (2003 to 2017)

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    Background: Antiretroviral therapy (ART) has been successful in improving clinical outcomes for HIV-positive patients, but efforts are needed to improve life expectancy and quality of life. This study aimed to analyze a long-term ART cohort and assess patients' life expectancy. Methods: A retrospective cohort study was conducted at the infectious and tropical diseases department of the University Teaching Hospital of Treichville from 2003 to 2017. Data analysis was done using VBA access and XLSTAT 2018 excel software. Patients on post-exposure chemoprophylaxis and prevention of mother-to-child transmission were excluded. Results: Out of 19,567 patient records, 49.60% were included, 72.43% were in 1st line, and 50.10% were over 50 years old, mostly female 58.49%, 98.4% HIV1. 74.31% had a CD4/mm3 (Nadir) count &lt;350. The patients were essentially on the 2IN+INN regimen (72.31%), TDF + XTC + EFV (20.57%). The average duration under treatment 6.15 [0-13.67] ±3.94 years, the average duration under a line of treatment 4.33 [0-14.04] ±2.96 years. Life expectancy was 10.37 years. It is higher in patients on 2IN+IPr (12.21 years) versus 10.12 years in patients on 2IN+INN. The comparison of duration on a line according to the CD4 counts and the line of treatment did not show a significant difference p&gt;0.05. Conclusions: The study concluded that ART significantly improved the life expectancy of patients, adherence could be improved to further enhance the benefits of ART. The use of new combinations of ART may reduce events related to non-compliance

    Bioinformatics and the politics of innovation in the life sciences: Science and the state in the United Kingdom, China, and India

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    The governments of China, India, and the United Kingdom are unanimous in their belief that bioinformatics should supply the link between basic life sciences research and its translation into health benefits for the population and the economy. Yet at the same time, as ambitious states vying for position in the future global bioeconomy they differ considerably in the strategies adopted in pursuit of this goal. At the heart of these differences lies the interaction between epistemic change within the scientific community itself and the apparatus of the state. Drawing on desk-based research and thirty-two interviews with scientists and policy makers in the three countries, this article analyzes the politics that shape this interaction. From this analysis emerges an understanding of the variable capacities of different kinds of states and political systems to work with science in harnessing the potential of new epistemic territories in global life sciences innovation

    The costs of functional gastrointestinal disorders and related signs and symptoms in infants: a systematic literature review and cost calculation for England

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    OBJECTIVES: To estimate the cost of functional gastrointestinal disorders (FGIDs) and related signs and symptoms in infants to the third party payer and to parents. STUDY DESIGN: To estimate the cost of illness (COI) of infant FGIDs, a two-stage process was applied: a systematic literature review and a COI calculation. As no pertinent papers were found in the systematic literature review, a 'de novo' analysis was performed. For the latter, the potential costs for the third party payer (the National Health Service (NHS) in England) and for parents/carers for the treatment of FGIDs in infants were calculated, by using publicly available data. In constructing the calculation, estimates and assumptions (where necessary) were chosen to provide a lower bound (minimum) of the potential overall cost. In doing so, the interpretation of the calculation is that the true COI can be no lower than that estimated. RESULTS: Our calculation estimated that the total costs of treating FGIDs in infants in England were at least £72.3 million per year in 2014/2015 of which £49.1 million was NHS expenditure on prescriptions, community care and hospital treatment. Parents incurred £23.2 million in costs through purchase of over the counter remedies. CONCLUSIONS: The total cost presented here is likely to be a significant underestimate as only lower bound estimates were used where applicable, and for example, costs of alternative therapies, inpatient treatments or diagnostic tests, and time off work by parents could not be adequately estimated and were omitted from the calculation. The number and kind of prescribed products and products sold over the counter to treat FGIDs suggest that there are gaps between treatment guidelines, which emphasise parental reassurance and nutritional advice, and their implementation
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