66 research outputs found

    A priori error estimates of a diusion equation with Ventcel boundary conditions on curved meshes

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    In this work is considered a diusion problem, referred to as the Ventcel problem, involving a second order term on the domain boundary (the Laplace-Beltrami operator). A variational formulation of the Ventcel problem is studied, leading to a nite element discretization. The focus is on the construction of high order curved meshes for the discretization of the physical domain and on the denition of the lift operator, which is aimed to transform a function dened on the mesh domain into a function dened on the physical one. This lift is dened in a way as to satisfy adapted properties on the boundary, relatively to the trace operator. Error estimations are computed and expressed both in terms of nite element approximation error and of geometrical error, respectively associated to the nite element degree k \ge 1 and to the mesh order r \ge 1. The numerical experiments we led allow us to validate the results obtained and proved on the a priori error estimates depending on the two parameters k and r

    Phase I, randomized, observer-blind, placebo-controlled studies to evaluate the safety, reactogenicity and immunogenicity of an investigational non-typeable Haemophilus influenzae (NTHi) protein vaccine in adults

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    Background: Non-typeable Haemophilus influenzae (NTHi) is a major cause of various respiratory diseases. The development of an effective vaccine against NTHi mandates new approaches beyond conjugated vaccines as this opportunistic bacterium is non-encapsulated. Here we report on the safety, reactogenicity and immunogenicity of a multi-component investigational vaccine based on three conserved surface proteins from NTHi (proteins D [PD],E [PE] and Pilin A [PilA]) in two observer-blind phase I studies. Methods: In the first study (NCT01657526), 48 healthy 18-40 year-olds received two vaccine formulations (10 or 30 mu g of each antigen [PD and a fusion protein PE-PilA]) or saline placebo at months 0 and 2. In the second study (NCT01678677), 270 50-70 year-olds, current or former smokers, received eight vaccine formulations (10 or 30 mu g antigen/dose non-adjuvanted or adjuvanted with alum, AS01(E) or ASO4(c)) or saline placebo at months 0,2 and 6 (plain and alum-adjuvanted groups) and at months 0 and 2 (AS-adjuvanted groups). Solicited and unsolicited adverse events (AEs) were recorded for 7 and 30 days post-vaccination, respectively; potential immune-mediated diseases (pIMDs) and serious AEs (SAEs) throughout the studies. Humoral and antigen-specific T-cell immunity (in study 2 only) responses were assessed up to 12 months post-vaccination. Results: Observed reactogenicity was highest in the AS-adjuvanted groups but no safety concerns were identified with any of the NTHi vaccine formulations. One fatal SAE (cardiac arrest) not considered related to vaccination, and one pIMD (non-serious psoriasis) in the Placebo group, were reported post-dose 3 in Study 2. All formulations generated a robust antibody response while the AS01-adjuvanted formulations produced the highest humoral and cellular immune responses. Conclusion: This study confirms that the NTHi vaccine formulations had an acceptable reactogenicity and safety profile and were immunogenic in adults. These results justify further clinical development of this NTHi vaccine candidate

    Measuring currents, ice drift, and waves from space: the Sea Surface KInematics Multiscale monitoring (SKIM) concept

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    We propose a new satellite mission that uses a near-nadir Ka-band Doppler radar to measure surface currents, ice drift and ocean waves at spatial scales of 40?km and more, with snapshots at least every day for latitudes 75 to 82, and every few days otherwise. The use of incidence angles at 6 and 12 degrees allows a measurement of the directional wave spectrum which yields accurate corrections of the wave-induced bias in the current measurements. The instrument principle, algorithm for current velocity and mission performance are presented here. The proposed instrument can reveal features on tropical ocean and marginal ice zone dynamics that are inaccessible to other measurement systems, as well as a global monitoring of the ocean mesoscale that surpasses the capability of today?s nadir altimeters. Measuring ocean wave properties facilitates many applications, from wave-current interactions and air-sea fluxes to the transport and convergence of marine plastic debris and assessment of marine and coastal hazards

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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