135 research outputs found

    Underwater acoustic slant range measurements related to weather and sea state

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    Underwater range measurements are key factor in underwater acoustic positioning, used in Long Base-Line (LBL) or Ultra Short Base-Line (USBL) computing techniques. These measurements are commonly carried out through acoustic communications between modems and their accuracy can be affected by different factors, such as sea state, weather conditions, and obstacles in the line of sight propagation. This is especially important in shallow waters areas, where others phenomena such as multi-path have to be considered. Therefore, range accuracy and the associated position estimation errors are an important area of research. Here, we addressed the relation between range measurements variability and sea state (i.e. currents or waves height) as proxy of real-world conditions, affecting acoustic positioning performances. For that purpose, a long-term deployment have been carried out in the underwater cabled observatory OBSEA, which provide different measurements of the sea and weather state.Peer ReviewedPostprint (published version

    Reduced trabecular bone mineral density and cortical thickness accompanied by increased outer bone circumference in metacarpal bone of rheumatoid arthritis patients: a cross-sectional study

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    Introduction The objective of this study was to assess three-dimensional bone geometry and density at the epiphysis and shaft of the third meta-carpal bone of rheumatoid arthritis (RA) patients in comparison to healthy controls with the novel method of peripheral quantitative computed tomography (pQCT). Methods PQCT scans were performed in 50 female RA patients and 100 healthy female controls at the distal epiphyses and shafts of the third metacarpal bone, the radius and the tibia. Reproducibility was determined by coefficient of varia-tion. Bone densitometric and geometric parameters were compared between the two groups and correlated to disease characteristics. Results Reproducibility of different pQCT parameters was between 0.7% and 2.5%. RA patients had 12% to 19% lower trabecular bone mineral density (BMD) (P ≤ 0.001) at the distal epiphyses of radius, tibia and metacarpal bone. At the shafts of these bones RA patients had 7% to 16% thinner cortices (P ≤ 0.03). Total cross-sectional area (CSA) at the metacarpal bone shaft of pa-tients was larger (between 5% and 7%, P < 0.02), and relative cortical area was reduced by 13%. Erosiveness by Ratingen score correlated negatively with tra-becular and total BMD at the epiphyses and shaft cortical thickness of all measured bones (P < 0.04). Conclusions Reduced trabecular BMD and thinner cortices at peripheral bones, and a greater bone shaft diameter at the metacarpal bone suggest RA spe-cific bone alterations. The proposed pQCT protocol is reliable and allows measuring juxta-articular trabecular BMD and shaft geometry at the metacarpal bone

    Ligand-Induced Incompatible Curvatures Control Ultrathin Nanoplatelet Polymorphism and Chirality

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    The ability of thin materials to shape-shift is a common occurrence that leads to dynamic pattern formation and function in natural and man-made structures. However, harnessing this concept to design inorganic structures at the nanoscale rationally has remained far from reach due to a lack of fundamental understanding of the essential physical components. Here, we show that the interaction between organic ligands and the nanocrystal surface is responsible for the full range of chiral shapes seen in colloidal nanoplatelets. The adsorption of ligands results in incompatible curvatures on the top and bottom surfaces of NPL, causing them to deform into helico\"ids, helical ribbons, or tubes depending on the lateral dimensions and crystallographic orientation of the NPL. We demonstrate that nanoplatelets belong to the broad class of geometrically frustrated assemblies and exhibit one of their hallmark features: a transition between helico\"ids and helical ribbons at a critical width. The effective curvature κˉ\bar{\kappa} is the single aggregate parameter that encodes the details of the ligand/surface interaction, determining the nanoplatelets' geometry for a given width and crystallographic orientation. The conceptual framework described here will aid the rational design of dynamic, chiral nanostructures with high fundamental and practical relevance.Comment: 16 pages, 8 figure

    Diagnostic du Projet d'agglomération franco-valdo-genevois de 2ème génération

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    Ce document répond à l’exigence de base 3 (EB3) de la directive pour l’examen et le cofinancement des projets d’agglomération de deuxième génération (DETEC, ARE, 2010). Le rapport présente une analyse de l’état actuel et des tendances de développement dans l'agglomération franco-valdo-genevoise et fait ressortir, pour tous les domaines (urbanisation, transport et environnement) les principales forces et faiblesses de l’agglomération. En lien avec les tendances de développement, il identifie les opportunités, les menaces et les besoins d’action. Ce document est l'annexe 1 du dossier de Projet d'agglomération 2012

    Active management of the third stage of labour without controlled cord traction: a randomized non-inferiority controlled trial

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    BACKGROUND: The third stage of labour refers to the period between birth of the baby and complete expulsion of the placenta. Some degree of blood loss occurs after the birth of the baby due to separation of the placenta. This period is a risky period because uterus may not contract well after birth and heavy blood loss can endanger the life of the mother. Active management of the third stage of labour (AMTSL) reduces the occurrence of severe postpartum haemorrhage by approximately 60-70%. Active management consists of several interventions packaged together and the relative contribution of each of the components is unknown. Controlled cord traction is one of those components that require training in manual skill for it to be performed appropriately. If it is possible to dispense with controlled cord traction without losing efficacy it would have major implications for effective management of the third stage of labour at peripheral levels of health care. OBJECTIVE: The primary objective is to determine whether the simplified package of oxytocin 10 IU IM/IV is not less effective than the full AMTSL package. METHODS: A hospital-based, multicentre, individually randomized controlled trial is proposed. The hypothesis tested will be a non-inferiority hypothesis. The aim will be to determine whether the simplified package without CCT, with the advantage of not requiring training to acquire the manual skill to perform this task, is not less effective than the full AMTSL package with regard to reducing blood loss in the third stage of labour.The simplified package will include uterotonic (oxytocin 10 IU IM) injection after delivery of the baby and cord clamping and cutting at approximately 3 minutes after birth. The full package will include the uterotonic injection (oxytocin 10 IU IM), controlled cord traction following observation of uterine contraction and cord clamping and cutting at approximately 3 minutes after birth. The primary outcome measure is blood loss of 1000 ml or more at one hour and up to two hours for women who continue to bleed after one hour. The secondary outcomes are blood transfusion, the use of additional uterotonics and measure of severe morbidity and maternal death.We aim to recruit 25,000 women delivering vaginally in health facilities in eight countries within a 12 month recruitment period. MANAGEMENT: Overall trial management will be from HRP/RHR in Geneva. There will be eight centres located in Argentina, Egypt, India, Kenya, Philippines, South Africa, Thailand and Uganda. There will be an online data entry system managed from HRP/RHR. The trial protocol was developed following a technical consultation with international organizations and leading researchers in the field. EXPECTED OUTCOMES: The main objective of this trial is to investigate whether a simplified package of third stage management can be recommended without increasing the risk of PPH. By avoiding the need for a manual procedure that requires training, the third stage management can be implemented in a more widespread and cost-effective way around the world even at the most peripheral levels of the health care system. This trial forms part of the programme of work to reduce maternal deaths due to postpartum haemorrhage within the RHR department in collaboration with other research groups and organizations active in the field. TRIAL REGISTRATION: ACTRN12608000434392

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation

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    BACKGROUND: To identify the best possible outcomes in liver transplantation from donation after circulatory death donors (DCD) and to propose outcome values, which serve as reference for individual liver recipients or patient groups. METHODS: Based on 2219 controlled DCD liver transplantations, collected from 17 centres in North America and Europe, we identified 1012 low-risk, primary, adult liver transplantations with a laboratory MELD of ≤20points, receiving a DCD liver with a total donor warm ischemia time of ≤30minutes and asystolic donor warm ischemia time of ≤15minutes. Clinically relevant outcomes were selected and complications were reported according to the Clavien-Dindo-Grading and the Comprehensive Complication Index (CCI). Corresponding benchmark cut-offs were based on median values of each centre, where the 75(th)-percentile was considered. RESULTS: Benchmark cases represented between 19.7% and 75% of DCD transplantations in participating centers. The one-year retransplant and mortality rate was 5.23% and 9.01%, respectively. Within the first year of follow-up, 51.1% of recipients developed at least one major complication (≥Clavien-Dindo-Grade-III). Benchmark cut-offs were ≤3days and ≤16days for ICU and hospital stay, ≤66% for severe recipient complications (≥Grade-III), ≤16.8% for ischemic cholangiopathy, and ≤38.9CCI points at one-year posttransplant. Comparisons with higher risk groups showed more complications and impaired graft survival, outside the benchmark cut-offs. Organ perfusion techniques reduced the complications to values below benchmark cut-offs, despite higher graft risk. CONCLUSIONS: Despite excellent 1-year survival, morbidity in benchmark cases remains high with more than half of recipients developing severe complications during 1-year follow-up. Benchmark cut-offs targeting morbidity parameters offer a valid tool to assess the protective value of new preservation technologies in higher risk groups, and provide a valid comparator cohort for future clinical trials. LAY SUMMARY: The best possible outcomes after liver transplantation of grafts donated after circulatory death (DCD) were defined using the concept of benchmarking. These were based on 2219 liver transplantations following controlled DCD donation in 17 centres worldwide. The following benchmark cut-offs for the most relevant outcome parameters were developed: ICU and hospital stay: ≤3 and ≤16 days; primary non function: ≤2.5%; renal replacement therapy: ≤9.6%; ischemic cholangiopathy: ≤16.8% and anastomotic strictures ≤28.4%. One-year graft loss and mortality were defined as ≤14.4% and 9.6%, respectively. Donor and recipient combinations with higher risk had significantly worse outcomes. The use of novel organ perfusion technology achieved similar, good results in this high-risk group with prolonged donor warm ischemia time, when compared to the benchmark cohort
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