158 research outputs found
Ahead of time deployment in ROM of a Java-OS
This article shows how it is possible to place a great part of a Java system in read-only memory in order to fit with the requirements of tiny devices. Java systems for such devices are commonly deployed off-board, then embedded on the target device in a ready-to-run form. Our approach is reach an advanced state of deployment off-board, which allows us to maximize the amount of data placed in read-only memory. Doing so, we are also able to reduce the overall size of the system
A Study on the Use of Checksums for Integrity Verification of Web Downloads
App stores provide access to millions of different programs that users can download on their computers. Developers can also make their programs available for download on their websites and host the program files either directly on their website or on third-party platforms, such as mirrors. In the latter case, as users download the software without any vetting from the developers, they should take the necessary precautions to ensure that it is authentic. One way to accomplish this is to check that the published fileâs integrity verification code â the checksum â matches that (if provided) of the downloaded file. To date, however, there is little evidence to suggest that such process is effective. Even worse, very few usability studies about it exist.
In this paper, we provide the first comprehensive study that assesses the usability and effectiveness of the manual checksum verification process. First, by means of an in-situ experiment with 40 participants and eye-tracking technology, we show that the process is cumbersome and error-prone. Second, after a 4-month long in-the-wild experiment with 134 participants, we demonstrate how our proposed solution â a Chrome extension that verifies checksums automatically â significantly reduces human errors, improves coverage, and has only limited impact on usability. It also confirms that, sadly, only a tiny minority of websites that link to executable files in our sample provide checksums (0.01%), which is a strong call to action for web standards bodies, service providers and content creators to increase the use of file integrity verification on their properties
Non-hyperbolic ergodic measures and horseshoes in partially hyperbolic homoclinic classes
We study a rich family of robustly non-hyperbolic transitive diffeomorphisms
and we show that each ergodic measure is approached by hyperbolic sets in
weak-topology and in entropy. For hyperbolic ergodic measures, it is a
classical result of A. Katok. The novelty here is to deal with non-hyperbolic
ergodic measures.Comment: 25 pages and 1 figur
An open vibration platform to evaluate postural control using a simple reinforcement learning agent
In this paper, our research team proposes an inexpensive open vibration platform built from easily available electronic components to be used as a tool by physiotherapists in order to help them in their evaluation of the postural control of individuals at risk of postural imbalance which could lead to falls. The platform has been thought to be easily reproducible and all the code necessary to make it work is made available on the researchersâ websites. In addition, a simple reinforcement learning agent has been developed and tested to automatically calibrate the vibration motors for optimal stimulation. Finally, we present in this paper pilot experiments done on 7 healthy participants (40.8 years old) to validate the proper functioning of the platform
Interactive Impacts of Silver and Phosphorus on Autotrophic Biofilm Elemental and Biochemical Quality for a Macroinvertebrate Consumer
Autotrophic biofilms are complex and fundamental biological compartments of many aquatic ecosystems. In particular, these biofilms represent a major resource for many invertebrate consumers and the first ecological barrier against toxic metals. To date, very few studies have investigated the indirect effects of stressors on upper trophic levels through alterations of the quality of biofilms for their consumers. In a laboratory study, we investigated the single and combined effects of phosphorus (P) availability and silver, a re-emerging contaminant, on the elemental [carbon (C):nitrogen (N):P ratios] and biochemical (fatty acid profiles) compositions of a diatom-dominated biofilm initially collected in a shallow lake. We hypothesized that (1) P and silver, through the replacement of diatoms by more tolerant primary producer species, reduce the biochemical quality of biofilms for their consumers while (2) P enhances biofilm elemental quality and (3) silver contamination of biofilm has negative effects on consumers life history traits. The quality of biofilms for consumers was assessed for a common crustacean species, Gammarus fossarum, by measuring organismsâ survival and growth rates during a 42-days feeding experiment. Results mainly showed that species replacement induced by both stressors affected biofilm fatty acid compositions, and that P immobilization permitted to achieve low C:P biofilms, whatever the level of silver contamination. Gammarids growth and survival rates were not significantly impacted by the ingestion of silver-contaminated resource. On the contrary, we found a significant positive relationship between the biofilm P-content and gammarids growth. This study underlines the large indirect consequences stressors could play on the quality of microbial biomass for consumers, and, in turn, on the whole food web
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Evaluation expérimantale des concentrations critiques de la témocilline vis-à -vis de souches d'entérobactérales.
Worldwide spread of antimicrobial resistance among community-acquired enterobacterales, especially ESBL, leads to a worrying consumption of last resort antibiotics like carbapenem. Derivative of ticarcillin, temocillin may be an attractive carbapenem-sparing agent including against some carbapenemase-producing enterobacterales (CPE). Nevertheless, there is still uncertainty regarding clinical breakpoints with 3 different values depending on countries (8 mg/L, 16 mg/L, 32 mg/L), moreover international consensus about this issue is awaited. In this context, three original studies were conducted along with a literature review. First, in vitro susceptibility to temocillin of 762 enterobacterales from community-acquired urinary tract infection was studied. In this area of low prevalence of ESBL and no CPE, the three routine susceptibility methods (disk diffusion, automate, Etest) were very accurate, epidemiological cut-off was set to 8 mg/L. Then, temocillin efficacy against enterobacterales producing or not producing Ă-lactamase (ESBL or CPE) was assessed by two complementary murine models. We demonstrated that temocillin exposure reproducing 2 g q12h regimen showed efficacy against strains with temocillin MIC of 8 mg/L. This regimen exhibited a lower, even though significant, efficacy against strain with temocillin MIC of 16 mg/L. On the over hand, it was not observed significant efficacy against strain with temocillin MIC of 32 mg/L whatever the regimen used (2 g q12h or q8h). All together this results and the literature review support a clinical breakpoints of 8 mg/L for2 g q12h regimen, and 16 mg/L for 2 g q8h regimen. This last proposition correspond to the new susceptibility category : âIntermediate â Susceptible, increase exposureâ from the last EUCAST recommendations.Dans le monde entier lâantibiorĂ©sistance des entĂ©robactĂ©rales communautaires, notamment par production de Ă-lactamase Ă spectre Ă©tendu (E-BLSE), conduit Ă une consommation prĂ©occupante dâantibiotique de dernier recours tels les carbapĂ©nĂšmes. DĂ©rivĂ© de la ticarcilline la tĂ©mocilline pourrait reprĂ©sentĂ©e une alternative y compris sur certaines entĂ©robactĂ©rales productrices de carbapĂ©nĂšmase (EPC). NĂ©anmoins, il existe une incertitude concernant les concentrations critiques distinguant les entĂ©robactĂ©rales sensibles des rĂ©sistantes avec trois valeurs selon les pays utilisateurs de tĂ©mocilline (8 mg/L, 16 mg/L ou 32 mg/L) tandis quâune harmonisation internationale reste en attente. En ce contexte trois travaux originaux ont Ă©tĂ© poursuivi ainsi quâune revue de la littĂ©rature. Il fut dâabord Ă©tudiĂ© in vitro la sensibilitĂ© Ă la tĂ©mocilline de 762 entĂ©robactĂ©rales responsables dâinfection urinaire communautaire. Dans un contexte de prĂ©valence faible des E-BLSE (5%) et nulle des EPC, les trois mĂ©thodes de routine (disque, automate, Etest) se sont rĂ©vĂ©lĂ©es trĂšs fiables, la borne Ă©pidĂ©miologique pour la tĂ©mocilline sâĂ©tablissant Ă 8 mg/L. Ensuite, lâefficacitĂ© de la tĂ©mocilline vis-Ă -vis dâentĂ©robactĂ©rales productrices ou non de Ălactamases (E-BLSE ou EPC) a Ă©tĂ© Ă©valuĂ©e dans deux modĂšles murins complĂ©mentaires. Il a Ă©tĂ© montrĂ© lâefficacitĂ© de la tĂ©mocilline Ă un schĂ©ma reproduisant la posologie humaine de 2 g toutes 12 h vis-Ă -vis dâentĂ©robactĂ©rales pour lesquels la CMI de la tĂ©mocilline Ă©tait de 8 mg/L. LâefficacitĂ© de ce schĂ©ma posologique, bien que significative, Ă©tait moindre vis-Ă -vis des isolats pour lesquels la CMI de la tĂ©mocilline Ă©tait de 16 mg/L. Par contre, il ne fut pas observĂ© dâefficacitĂ© significative de la tĂ©mocilline vis-Ă -vis des isolats avec une CMI Ă 32 mg/L quelques soit le schĂ©ma posologique (2 g toutes les 8 ou 12 h). Lâensemble de ces rĂ©sultats, ainsi quâune revue exhaustive des donnĂ©es de la littĂ©rature, conduisent Ă proposer une concentration critique de 8 mg/L pour le schĂ©ma posologique de 2 g toutes les 12 h, et de 16 mg/L pour celui de 2 g toutes les 8h. Cette derniĂšre proposition correspondrait au « sensible Ă forte exposition », nouvelle dĂ©finition de la catĂ©gorisation « intermĂ©diaire » selon les derniĂšres recommandations de lâEUCAST
Evaluation expérimantale des concentrations critiques de la témocilline vis-à -vis de souches d'entérobactérales.
Worldwide spread of antimicrobial resistance among community-acquired enterobacterales, especially ESBL, leads to a worrying consumption of last resort antibiotics like carbapenem. Derivative of ticarcillin, temocillin may be an attractive carbapenem-sparing agent including against some carbapenemase-producing enterobacterales (CPE). Nevertheless, there is still uncertainty regarding clinical breakpoints with 3 different values depending on countries (8 mg/L, 16 mg/L, 32 mg/L), moreover international consensus about this issue is awaited. In this context, three original studies were conducted along with a literature review. First, in vitro susceptibility to temocillin of 762 enterobacterales from community-acquired urinary tract infection was studied. In this area of low prevalence of ESBL and no CPE, the three routine susceptibility methods (disk diffusion, automate, Etest) were very accurate, epidemiological cut-off was set to 8 mg/L. Then, temocillin efficacy against enterobacterales producing or not producing Ă-lactamase (ESBL or CPE) was assessed by two complementary murine models. We demonstrated that temocillin exposure reproducing 2 g q12h regimen showed efficacy against strains with temocillin MIC of 8 mg/L. This regimen exhibited a lower, even though significant, efficacy against strain with temocillin MIC of 16 mg/L. On the over hand, it was not observed significant efficacy against strain with temocillin MIC of 32 mg/L whatever the regimen used (2 g q12h or q8h). All together this results and the literature review support a clinical breakpoints of 8 mg/L for2 g q12h regimen, and 16 mg/L for 2 g q8h regimen. This last proposition correspond to the new susceptibility category : âIntermediate â Susceptible, increase exposureâ from the last EUCAST recommendations.Dans le monde entier lâantibiorĂ©sistance des entĂ©robactĂ©rales communautaires, notamment par production de Ă-lactamase Ă spectre Ă©tendu (E-BLSE), conduit Ă une consommation prĂ©occupante dâantibiotique de dernier recours tels les carbapĂ©nĂšmes. DĂ©rivĂ© de la ticarcilline la tĂ©mocilline pourrait reprĂ©sentĂ©e une alternative y compris sur certaines entĂ©robactĂ©rales productrices de carbapĂ©nĂšmase (EPC). NĂ©anmoins, il existe une incertitude concernant les concentrations critiques distinguant les entĂ©robactĂ©rales sensibles des rĂ©sistantes avec trois valeurs selon les pays utilisateurs de tĂ©mocilline (8 mg/L, 16 mg/L ou 32 mg/L) tandis quâune harmonisation internationale reste en attente. En ce contexte trois travaux originaux ont Ă©tĂ© poursuivi ainsi quâune revue de la littĂ©rature. Il fut dâabord Ă©tudiĂ© in vitro la sensibilitĂ© Ă la tĂ©mocilline de 762 entĂ©robactĂ©rales responsables dâinfection urinaire communautaire. Dans un contexte de prĂ©valence faible des E-BLSE (5%) et nulle des EPC, les trois mĂ©thodes de routine (disque, automate, Etest) se sont rĂ©vĂ©lĂ©es trĂšs fiables, la borne Ă©pidĂ©miologique pour la tĂ©mocilline sâĂ©tablissant Ă 8 mg/L. Ensuite, lâefficacitĂ© de la tĂ©mocilline vis-Ă -vis dâentĂ©robactĂ©rales productrices ou non de Ălactamases (E-BLSE ou EPC) a Ă©tĂ© Ă©valuĂ©e dans deux modĂšles murins complĂ©mentaires. Il a Ă©tĂ© montrĂ© lâefficacitĂ© de la tĂ©mocilline Ă un schĂ©ma reproduisant la posologie humaine de 2 g toutes 12 h vis-Ă -vis dâentĂ©robactĂ©rales pour lesquels la CMI de la tĂ©mocilline Ă©tait de 8 mg/L. LâefficacitĂ© de ce schĂ©ma posologique, bien que significative, Ă©tait moindre vis-Ă -vis des isolats pour lesquels la CMI de la tĂ©mocilline Ă©tait de 16 mg/L. Par contre, il ne fut pas observĂ© dâefficacitĂ© significative de la tĂ©mocilline vis-Ă -vis des isolats avec une CMI Ă 32 mg/L quelques soit le schĂ©ma posologique (2 g toutes les 8 ou 12 h). Lâensemble de ces rĂ©sultats, ainsi quâune revue exhaustive des donnĂ©es de la littĂ©rature, conduisent Ă proposer une concentration critique de 8 mg/L pour le schĂ©ma posologique de 2 g toutes les 12 h, et de 16 mg/L pour celui de 2 g toutes les 8h. Cette derniĂšre proposition correspondrait au « sensible Ă forte exposition », nouvelle dĂ©finition de la catĂ©gorisation « intermĂ©diaire » selon les derniĂšres recommandations de lâEUCAST
Place de la témocilline dans le traitement probabiliste des infections urinaires communautaires
Contexte : La tĂ©mocilline est un antibiotique de la famille des Ă-lactamines connaissant un regain dâintĂ©rĂȘt pour le traitement des infections urinaires (IU) communautaires dans le contexte de lâĂ©volution prĂ©occupante de la rĂ©sistance bactĂ©rienne des entĂ©robactĂ©ries communautaires. Objectifs : Le but fut dâanalyser le niveau actuel de la sensibilitĂ© Ă la tĂ©mocilline des isolats urinaires dâentĂ©robactĂ©ries circulant en France ainsi que la fiabilitĂ© des deux seules mĂ©thodes actuellement disponibles en routine, compte-tenu dâincertitudes Ă cet Ă©gard. MatĂ©riels et mĂ©thodes : Les entĂ©robactĂ©ries dâun souchier constituĂ© en Normandie en 2015- 2017 ont Ă©tĂ© analysĂ©es. La sensibilitĂ© Ă la tĂ©mocilline a Ă©tĂ© Ă©valuĂ©e par la mĂ©thode des disques et par bandelette Ă gradient de concentration comparativement Ă la technique de rĂ©fĂ©rence (dilution en milieu gĂ©losĂ© solide). Les rĂ©sultats ont Ă©tĂ© analysĂ©s selon les 3 concentrations critiques (cC) en vigueur : seuil de sensibilitĂ© Ă 8 mg/L, 16 mg/L ou 32 mg/L. RĂ©sultats : Au total, 820 entĂ©robactĂ©ries ont Ă©tĂ© analysĂ©es dont 710 (86,6 %) Escherichia coli. Le pourcentage de sensibilitĂ© Ă la tĂ©mocilline selon la mĂ©thode de rĂ©fĂ©rence Ă©tait de 99,4 % pour une cC de 8 mg/L, et de 100 % pour des cC de 16 mg/L et 32 mg/L. Il nâĂ©tait pas observĂ© de diffĂ©rence du taux de sensibilitĂ© selon lâĂąge, le sexe, ou la forme clinique dâIU (p>0,05). Le taux de sensibilitĂ© Ă©tait plus faible pour les 41 entĂ©robactĂ©ries (5 %) productrices de Ă-lactamase Ă spectre Ă©tendu : 95,1 % vs 99,6 % Ă la cC de 8 mg/L (p=0,02). Les taux de discordances entre les mĂ©thodes de routine et la rĂ©fĂ©rence Ă©taient faibles : Conclusion : La sensibilitĂ© Ă la tĂ©mocilline des entĂ©robactĂ©ries responsables dâIU est particuliĂšrement Ă©levĂ©e, mĂȘme en utilisant la norme la plus exigeante, et les deux mĂ©thodes dâĂ©valuation en routine sont des plus fiables, permettant de discuter la place de la molĂ©cule en stratĂ©gie probabiliste
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