335 research outputs found
Toward a tool aimed to quantify soil compaction risks at a regional scale: application to Wallonia (Belgium)
The spatial analysis of the soil compaction risk has been developed at the regional level and applied to Wallonia (Belgium). The methodology is based on the estimation of the probability of exceeding the preconsolidation stress due to the application of loads on the soil.
Preconsolidation stresses (Pc) are computed from the pedotransfer functions of Horn and Fleige (2003) at pF 1.8 and 2.5 and classified into 6 categories ranging from very low Pc ( 150 kPa). The computation requires the knowledge of pedological (texture, organic content), mechanical (bulk density, cohesion, internal friction angle), and hydraulic variables (water content available, non-available water content, air capacity, saturated hydraulic conductivity). These variables are obtained from databases like HYPRES or AARDEWERK or from pedotransfer functions. The computation of Pc takes into account the spatial structure of the data: in some cases, data are abundant (e.g. texture data) and spatial variability is taken into account through geostatistical methods. In other cases, the data is sparse but uncertainty information can be extracted from the knowledge of the statistical distribution. Maps of the most probable Pc class are produced. Uncertainty is computed as the classification error probability. Implementation of these methods in Wallonia showed that Pc values higher than 120 kPa are reached either on 64 % of the territory at pF 2.5 or on 55 % at pF 1.8. A higher uncertainty was found at pF 2.5 than at pF 1.8. Uncertainty was also found higher for clay and clayed loess than for other textural classes present in Wallonia.
The risk of compaction is defined as the probability that Pc is exceeded by the stress created by a load applied to the soil at a depth of 40 cm, the loads being similar to those induced by agricultural or forestry tires. It appeared that subsoil compaction risks exist mainly in loamy forest soils with small coarse fragments supporting loads similar to that existing on logging machines.
In the zones where the uncertainty is low, the developed tool could be used as a basis for providing policy measures in order to promote soil-friendly farming and forest practices.Etude de la compaction des sols de Walloni
Couplage de mesures sur site et de méthodes géostatistiques : mise en oeuvre " en temps réel " à l'aide d'un FPXRF Projet REPERAGE
National audienceLa caractérisation des sites pollués effectuée à l'aide de prélèvements de sol et d'analyses de laboratoire est une étape longue et coûteuse. De telles pratiques incitent à limiter le nombre de points de mesure et ne permettent pas facilement, dans une même campagne, d'utiliser les premiers résultats d'analyse pour ajuster la localisation de nouveaux points d'échantillonnage. Depuis plusieurs années sont apparus sur le marché de nouveaux appareils portatifs permettant d'analyser sur le terrain la teneur en polluants dans les sols en un temps très court. Parmi ceux-ci les spectromètres portables à fluorescence de rayons X (FPXRF) sont de plus en plus utilisés pour analyser les métaux. Dans le même temps, des approches géostatistiques adaptées aux particularités des sites et sols pollués ont été développées en Europe et sont de plus en plus utilisées pour cartographier les sols en fonction de seuils réglementaires ou estimer des quantités de matériaux contaminés, tout en en quantifiant les incertitudes locales ou globales associées. Le couplage des deux outils, mesures sur site et méthodes géostatistiques, permet d'envisager des campagnes de reconnaissance optimisées où le nombre et la localisation de nouveaux points de mesure sont déterminés au fur et à mesure de l'acquisition des données dans l'objectif de réduire l'incertitude affectant la modélisation de la contamination. Le projet de recherche REPERAGE vise à concevoir une démarche associant mesures sur site et traitement géostatistique pour conduire de façon rationnelle des campagnes de reconnaissance par rapport à des scénarios et des objectifs classiques de gestion de sites contaminés (par ex. classification des sols par rapport à des seuils, estimation de tonnages, estimation de coûts de dépollution). Le travail réalisé inclut le développement théorique de la démarche et d'un code permettant de la mettre en oeuvre, la validation de la démarche à partir des données d'un site réel bien renseigné, les environs de l'ancienne usine MétalEurop (Nord de la France), et sa mise en oeuvre " en temps réel " sur le site d'une ancienne usine sidérurgique (Henricot II, Belgique). La communication aura pour objet de présenter les principaux résultats obtenus dans le cadre de ce projet
The lived experience of younger people with a disability living in residential aged care facilities: a phenomenological study
The topic of younger people with a disability living in aged care facilities is somewhat hidden and undiscussed in Australia. The term 'younger people' is defined in health and disability policy as people aged between 18 and 65 years of age. For the purpose of this research, 'younger people' include people under the age of 65 years with a disability (Australian Institute of Health and Welfare, 2012). Younger people with a disability requiring high level needs have limited options in relation to the provision of care because there is insufficient funding, negligible facilities and limited community-based structures to assist individuals to remain living in regional or rural communities. Of note, community-based care is minimal and unavailable to over 7000 younger Australians who currently reside in aged care facilities (Commonwealth of Australia, 2015). Therefore, this study involves younger people with a disability who reside in residential aged care facilities because of inadequate support in the community to meet the level of care they require.
Constantly emerging technological advances in health care enable people with disabilities to live longer and healthier lives. However, ageing carers can struggle to meet the subsequent care requirements of a person with a disability who is also ageing. Likewise, the carer themselves may be experiencing health and age-related difficulties, resulting in an inability to adequately provide the care and support required for the younger person with a disability. Furthermore, the nature of families in today’s society means it is not always viable for relatives to provide informal care to a younger person with high level care needs. The financial burden placed on people today require adult family members to be engaged in paid employment as opposed to remaining at home to care for an individual. Inadequate resourcing by governments to supplement informal care provision results in disabled younger people having to be placed in residential aged care facilities. Therefore, it is essential to gain an understanding of the experiences of younger people with a disability placed in residential aged care facilities to provide a realistic account surrounding this hidden topic.
The research presented in this thesis is an exploration of the experiences of younger people with a disability living in residential aged care facilities. This study aims to gain insight into the psychosocial impacts of placement in a residential aged care facility and identify strategies the younger person with a disability utilises to adjust to their living environment. Interpretive phenomenology was employed as the methodology to explore the essence of the individual’s experience. Focussing on individual experiences and what was important to participants enabled a more thorough understanding of the impact of living in a residential aged care facility as a younger person. Moreover, this study assisted to identify strategies the participants adopted to help them adjust to the aged
care environment and findings highlighted aspects that could be improved to better meet the needs of this marginalised group.
The key findings of this study indicate that younger people with a disability living in residential aged care facilities experience significant loss. Loss of
relationships with family and friends, loss of ndependence, and loss of connection with the broader community were common themes. Participants countering the losses exercised resilience and adopted resilience-enhancing strategies. For instance, meaning making and benefit finding were strategies that assisted the participant to adjust to living in the residential aged care environment, while acknowledging that the quality of their lives maybe enhanced by meeting aspects of their social, emotional and psychological needs
Information-Theoretic Topology-Hiding Broadcast: Wheels, Stars, Friendship, and Beyond
Topology-hiding broadcast (THB) enables parties communicating over an incomplete network to broadcast messages while hiding the network topology from within a given class of graphs. Although broadcast is a privacy-free task, it is known that THB for certain graph classes necessitates computational assumptions, even against "honest but curious" adversaries, and even given a single corrupted party. Recent works have tried to understand when THB can be obtained with information-theoretic (IT) security (without cryptography or setup assumptions) as a function of properties of the corresponding graph class.
We revisit this question through a case study of the class of wheel graphs and their subgraphs. The nth wheel graph is established by connecting n nodes who form a cycle with another "center" node, thus providing a natural extension that captures and enriches previously studied graph classes in the setting of IT-THB.
We present a series of new findings in this line. We fully characterize feasibility of IT-THB for any class of subgraphs of the wheel, each possessing an embedded star (i.e., a well-defined center connected to all other nodes). Our characterization provides evidence that IT-THB feasibility may correlate with a more fine-grained degree structure - as opposed to pure connectivity - of the corresponding graphs. We provide positive results achieving perfect IT-THB for new graph classes, including ones where the number of nodes is unknown. Further, we provide the first feasibility of IT-THB on non-degenerate graph-classes with t > 1 corruptions, for the class of friendship graphs (Erdös, Rényi, Sós '66)
Dans un établissement d’enseignement fondamental spécialisé, comment le coordinateur pédagogique, caractérisé de marginal sécant, peut-il accompagner son équipe dans les changements qui y sont opérés ? :L’activité du coordinateur pédagogique en Fédération Wallonie-Bruxelles, accompagnateur de changements organisationnels, au cœur d’enjeux institutionnels
Mapping of Schistosomiasis and Soil-Transmitted Helminthiasis in the Regions of Centre, East and West Cameroon
Schistosomiasis and soil-transmitted helminthiasis (STH) are a major public health problem in Cameroon. The national control strategy of these diseases was based on historical data collected 25 years ago, which might be outdated in some situations due to several factors including control activities, improved or degraded sanitation and hygiene, socio-economic improvement and disease transmission dynamics. To help planning, improving control strategies and evaluation of control activities, there was a need to update the distribution of schistosomiasis and STH. We conducted parasitological surveys in three regions of Cameroon, i.e. Centre, East and West. Our results showed a significant decrease of STH infection prevalence and intensities in all these three regions, in comparison to previous mapping data, with an overall decline of prevalence from 81.1–93% to 10.5–46.6%. These results show the positive impact of annual deworming campaigns, and illustrate the progressive success of the national programme for the control of schistosomiasis and STH in Cameroon. Furthermore, our results showed an increase of the number of high transmission foci of schistosomiasis, and allowed identifying new health districts requiring mass treatment with praziquantel, and those where deworming should be reinforced
Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials
BACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ).
METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence.
RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I(2) = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis.
CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care
Risk assessment of soil compaction in Walloon Region
peer reviewedIt is well established that soil compaction affects the growth and functioning of roots and disrupts the activity of microfauna and soil microorganisms, resulting in a loss of yields. Agriculture and forestry using increasingly heavy machines, the risk of soil compaction is increasing accordingly.
Chosen as indicator of the susceptibility of soils to compaction, the precompression stress (Pc) is calculated using the pedotransfer functions (PTFs) proposed by Horn and Fleige (2003). These PTFs involve eight parameters linked to the hydraulic and mechanical behaviour of soils: organic matter content, bulk density, air capacity, available and non-plant available water capacity, saturated hydraulic conductivity, cohesion and angle of internal friction.
The challenge consists in producing Pc maps at the regional scale for Wallonia. Those maps should also be accompanied by estimation uncertainty map. Finally, the results should be exploited to produce compaction risk maps according to various frequent scenarios.
In this paper, a methodology is proposed, combining geostatistics and Monte Carlo simulations, to achieve these goals
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