508 research outputs found

    Acoustically induced and controlled micro-cavitation bubbles as active source for transcranial adaptive focusing

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    The skull bone is a strong aberrating medium for ultrasound in the low MHz range. Brain treatment with High Intensity Focused Ultrasound (HIFU) can however be achieved through the skull by multichannel arrays using an adaptive focusing technique. Time-reversal is a robust adaptive technique for correction of aberrations. It achieves moreover a matched filter and then allows the optimal energy concentration for thermal therapy. Nevertheless, this method requires a reference signal sent by a source embedded in brain tissues. Acoustically generated cavitation bubbles are active acoustic sources which can be remotely generated. Therefore, they are suited for this non-invasive time reversal aberration correction. We report here in vitro experiments where micro-cavitation was induced transcranially in agar gel at targeted positions using a coarse aberration correction either obtained from CT-scan based simulations or conventional steering. The bubbles' ultrasonic signature received by the array were then successfully used to optimally focus at the designated locations.http://deepblue.lib.umich.edu/bitstream/2027.42/84308/1/CAV2009-final134.pd

    Fatigue resistance: is it possible having a unique response?

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    The mechanical characterisation of the asphalt concrete in terms of both the fatigue resistance and the stiffness modulus is necessary to use any design method of the flexible road pavements. Different kinds of test are usually used in experimental work such as bending tests, uniaxial tests, etc., but sometimes they do not give the same answer. In this paper mechanical characterization was carried out by means of fatigue tests undertaken with two most used testing machines for asphalt material: two point bending (2PB) test at IFSTTAR in Nantes (France) and four point bending (4PB) test at University of Palermo, in Palermo (Italy). Different strain controlled tests were undertaken for the same material under the same loading conditions, frequency and temperature (15 Hz and 20ËšC), according to the European standard 12697 part 24 and 26. The first results of this interlaboratory activity are showed in this paper

    Data collection protocol

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    This document shows the data collection protocol to perform the sustainability assessment of different 4CE-MED cropping systems by applying life cycle thinking methodologies. Within 4CE-MED project, WP4 will select 3 countries and trials will be selected to compare the sustainability performance of current situations with the introduction of 4CE-MED cropping systems. The cases will belong to three major camelina cropping models presented in the project: Model A introduces Camelina to replace fallow in winter cereal sole-cropping systems, in marginal areas with very dry climate; Model B considers Camelina as a double-cropping cultivation in autumn, to precede typical Mediterranean summer crops; and Model C uses Camelina as a double-cropping in late spring/early summer in colder areas to follow winter pulses (e.g. pea) or cereals harvested as fodder. The selected cases would have followed the experimental protocol presented in WP2. This protocol is based on the Methodological framework to develop life cycle thinking assessment on 4CE-MED systems (D4.1). A literature review was also conducted for this deliverable, which allowed to observe there is limited LCA, E-LCC and S-LCA studies of the Camelina crop in Mediterranean regions. Most of the information found is referred to the application of Camelina as biofuel, while some articles even highlighted that camelina is not used as food. The definition of a goal and scope, expressed in the methodological framework for the assessment, expects to conduct a cradle-to-farm gate assessment with functionality based mostly on yield, and a perspective based on the crop succession. Functional unit is expected to be mass based, with derivations towards the environmental, economic and social impact categories of interest. The environmental dimension will refer to midpoint categories, with a consistent use as in most of the studies of Global Warming Potential, Eutrophication Potential and Terrestrial Acidification Potential. Regarding the economic dimension, cost categories, income and net margin will be observed, and the social dimension will include impact categories that range from endpoint to midpoint categories, where human rights, working conditions and community are to be addressed

    A Parent-Led Intervention to Promote Recovery Following Pediatric Injury: Study Protocol for a Randomized Controlled Trial

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    Background: Injury is one of the most prevalent potentially emotionally traumatic events that children experience and can lead to persistent impaired physical and emotional health. There is a need for interventions that promote full physical and emotional recovery and that can be easily accessed by all injured children. Based on research evidence regarding post-injury recovery, we created the Cellie Coping Kit for Children with Injury intervention to target key mechanisms of action and refined the intervention based on feedback from children, families, and experts in the field. The Cellie Coping Kit intervention is parent-guided and includes a toy (for engagement), coping cards for children, and a book for parents with evidence-based strategies to promote injury recovery. This pilot research trial aims to provide an initial evaluation of the impact of the Cellie Coping Kit for Children with Injury on proximal targets (coping, appraisals) and later child health outcomes (physical recovery, emotional health, health-related quality of life). Method / Design: Eighty children (aged 8–12 years) and their parents will complete a baseline assessment (T1) and then will be randomly assigned to an immediate intervention group or waitlist group. The Cellie Coping Kit for Injury Intervention will be introduced to the immediate intervention group after the T1 assessment and to the waitlist group following the T3 assessment. Follow-up assessments of physical and emotional health will be completed at 6 weeks (T2), 12 weeks (T3), and 18 weeks (T4). Discussion: This will be one of the first randomized controlled trials to examine an intervention tool intended to promote full recovery after pediatric injury and be primarily implemented by children and parents. Results will provide data on the feasibility of the implementation of the Cellie Coping Intervention for Injury as well as estimations of efficacy. Potential strengths and limitations of this design are discussed. Trial Registration: Clinicaltrials.gov, NCT03153696. Registered on 15 May 2017

    Infection of human monocyte-derived dendritic cells by ANDES Hantavirus enhances pro-inflammatory state, the secretion of active MMP-9 and indirectly enhances endothelial permeability

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    <p>Abstract</p> <p>Background</p> <p>Andes virus (ANDV), a rodent-borne Hantavirus, is the major etiological agent of Hantavirus cardiopulmonary syndrome (HCPS) in South America, which is mainly characterized by a vascular leakage with high rate of fatal outcomes for infected patients. Currently, neither specific therapy nor vaccines are available against this pathogen. ANDV infects both dendritic and epithelial cells, but in despite that the severity of the disease directly correlates with the viral RNA load, considerable evidence suggests that immune mechanisms rather than direct viral cytopathology are responsible for plasma leakage in HCPS. Here, we assessed the possible effect of soluble factors, induced in viral-activated DCs, on endothelial permeability. Activated immune cells, including DC, secrete gelatinolytic matrix metalloproteases (gMMP-2 and -9) that modulate the vascular permeability for their trafficking.</p> <p>Methods</p> <p>A clinical ANDES isolate was used to infect DC derived from primary PBMC. Maturation and pro-inflammatory phenotypes of ANDES-infected DC were assessed by studying the expression of receptors, cytokines and active gMMP-9, as well as some of their functional status. The ANDES-infected DC supernatants were assessed for their capacity to enhance a monolayer endothelial permeability using primary human vascular endothelial cells (HUVEC).</p> <p>Results</p> <p>Here, we show that <it>in vitro </it>primary DCs infected by a clinical isolate of ANDV shed virus RNA and proteins, suggesting a competent viral replication in these cells. Moreover, this infection induces an enhanced expression of soluble pro-inflammatory factors, including TNF-α and the active gMMP-9, as well as a decreased expression of anti-inflammatory cytokines, such as IL-10 and TGF-β. These viral activated cells are less sensitive to apoptosis. Moreover, supernatants from ANDV-infected DCs were able to indirectly enhance the permeability of a monolayer of primary HUVEC.</p> <p>Conclusions</p> <p>Primary human DCs, that are primarily targeted by hantaviruses can productively be infected by ANDV and subsequently induce direct effects favoring a proinflammatory phenotype of infected DCs. Finally, based on our observations, we hypothesize that soluble factors secreted in ANDV-infected DC supernatants, importantly contribute to the endothelial permeability enhancement that characterize the HCPS.</p

    Using historical fisheries data to predict tuna distribution within the British Indian Ocean Territory marine protected area, and implications for its management

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    1. Recently, several large marine protected areas (MPAs) have been established globally and it is hoped that they will aid the recovery of populations of highly-mobile, large pelagic species. Understanding the distribution of these species within MPAs is key to delivering effective management but monitoring can be challenging over such vast areas of open ocean. 2. Historical fisheries data, collected prior to reserve establishment, can provide an insight into the past distributions of target species. We investigated the 10spatial and temporal distribution of yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tuna catch using logbook data from the purse seine fishery in British Indian Ocean Territory (BIOT) from 1996 to 2010, before it was established as an MPA in April 2010. 3. Generalized additive models (GAMs) were used to predict tuna presence and relative abundance from fishing records in relation to temporal and environmental variables. Significant variables included sea salinity, temperature and water velocity. 4. Predictions from the models identified a distinct hotspot for large yellowfin tuna within the MPA, and areas of high predicted relative abundance of skipjack tuna. We recommend that these areas are used as focal points from which populations can be monitored and investigations into tuna residency time can occur, so that the effectiveness of the MPA in conserving highly-mobile pelagic fish can be determined

    Première évaluation du risque toxique lié aux cyanobactéries d'eau douce en France : le programme " EFFLOCYA "

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    Une enquête menée à l'aide d'un questionnaire couvrant l'ensemble du territoire français ainsi que l'étude spécifique d'écosystèmes aquatiques de type lacs et réservoirs ont permis de montrer que les proliférations de cyanobactéries toxiques pouvaient a priori affecter n'importe quel plan d'eau de l'Héxagone. Les genres rencontrés responsables de la production de toxines, le plus souvent hépatiques, sont Microcystis, Planktothrix, Anabœna et Cylindrospermopsis.Les efflorescences peuvent se produire tout au long de l'année car certaines espèces sont adaptées aux eaux froides et elles ne sont pas liées de manière univoque à un état eutrophe de l'écosystème.La production toxinique est la plus élevée lorsque les populations cyanobactériennes sont peu ou pas diversifiées et à la lumière de travaux récents, cette production serait favorisée, en ce qui concerne les microcystines, par un milieu riche en nitrate, pauvre en ammonium et fortement carencé en fer.La suite à donner à ce travail pourrait être la création d'un observatoire national des efflorescences toxiques.An inquiry covering the whole French territory together with specific studies of natural and artificial reservoirs has been made to assess the human health risk related to the prolifération of toxin producing blue green algae (cyanobacteria). The conclusions show that any lentic ecosystem can be affected like it has been shown already in other countries all over the world and more specifically within the EU. The main genus concemed are: Microcystis, Planktothrix, Anabœna and Cylindrospermopsis.Blooms can occur juring the whole year since some species are well adapted to cold water and are not clearly linked with the trophic status of the aquatic ecosystem.The toxinic production is the largest when the cyanobacteria populations contain only a few number of species. The results of recent works are well correlated with our findings which show that the production of toxic heptapeptides (microcystins) could be correlated with high levels of nitrate and depletions of ammonium and iron.The follow up of this work should now include the set up of a national observatory of toxic algal blooms
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