5,941 research outputs found

    Microburst phenomena. I - Auroral zone X-rays

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    Balloon observations of auroral zone bremsstrahlung X-ray microburst

    One-Pot Phosphate-Mediated Synthesis of Novel 1,3,5-Trisubstituted Pyridinium Salts: A New Family of S. aureus Inhibitors

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    Polysubstituted pyridinium salts are valuable pharmacophores found in many biologically active molecules. Their synthesis typically involves the use of multistep procedures or harsh reaction conditions. Here, we report water-based phosphate mediated reaction conditions that promote the condensation of arylacetaldehydes with amines to give 1,3,5-pyridinium salts. The reaction, carried out at pH 6, provides conditions suitable for the use of less stable aldehydes and amines in this Chichibabin pyridine condensation. The evaluation of selected 1,3,5-trisubstituted pyridinium salts highlighted that they can inhibit the growth of S. aureus in the low μg/mL range. The synthetic accessibility of these compounds and preliminary growth inhibition data may pave the way towards the discovery of new anti-bacterials based on the 1,3,5-trisubstituted pyridinium scaffold

    Interactions Localisations Transport. Projet ILOT – Phase I. Rapport final pour la DRAST

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    Le projet ILOT consiste à appliquer la modélisation multi-agents aux rapports entre mobilité locale et transformation des espaces dans les aires urbaines. Il vise à développer dans un premier temps un ensemble de "briques" théoriques susceptibles de représenter de manière pertinente l'émergence de comportements collectifs en matière de rythmes temporels d'activités et de localisation. A plus long terme, ces "briques" théoriques seront le matériau de base pour élaborer des modèles plus appliqués, susceptibles d'être confrontés à des situations réelles.L'objectif à long terme de cette recherche consiste à réaliser des outils opérationnels, pour la recherche dans un premier temps et pour l'application dans un second temps, qui permettent de comprendre et d'analyser l'interaction entre la mobilité et la localisation dans les aires urbaines.Trois étapes ont été préalables identifiées qui semblent pertinentes :- l'exploration théorique de l'émergence de comportements "stylisés" de rythmes temporels et de localisation d'activités à travers une "ville-modèle",- le couplage de modèles éprouvés dans les domaines respectifs du transport et de la localisation, en particulier les modèles applicables à des problèmes pratiques,- l'identification et la résolution des obstacles informatiques relatifs à la simulation, à la collecte des données et à l'analyse des résultats de ces modèles

    Separation of suspended particles in microfluidic systems by directional-locking in periodic fields

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    We investigate the transport and separation of overdamped particles under the action of a uniform external force in a two-dimensional periodic energy landscape. Exact results are obtained for the deterministic transport in a square lattice of parabolic, repulsive centers that correspond to a piecewise-continuous linear-force model. The trajectories are periodic and commensurate with the obstacle lattice and exhibit phase-locking behavior in that the particle moves at the same average migration angle for a range of orientation of the external force. The migration angle as a function of the orientation of the external force has a Devil's staircase structure. The first transition in the migration angle was analyzed in terms of a Poincare map, showing that it corresponds to a tangent bifurcation. Numerical results show that the limiting behavior for impenetrable obstacles is equivalent to the high Peclet number limit in the case of transport of particles in a periodic pattern of solid obstacles. Finally, we show how separation occurs in these systems depending on the properties of the particles

    Interactions Localisations Transport. Projet ILOT – Phase I. Rapport final pour la DRAST

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    Le projet ILOT consiste à appliquer la modélisation multi-agents aux rapports entre mobilité locale et transformation des espaces dans les aires urbaines. Il vise à développer dans un premier temps un ensemble de "briques" théoriques susceptibles de représenter de manière pertinente l'émergence de comportements collectifs en matière de rythmes temporels d'activités et de localisation. A plus long terme, ces "briques" théoriques seront le matériau de base pour élaborer des modèles plus appliqués, susceptibles d'être confrontés à des situations réelles.L'objectif à long terme de cette recherche consiste à réaliser des outils opérationnels, pour la recherche dans un premier temps et pour l'application dans un second temps, qui permettent de comprendre et d'analyser l'interaction entre la mobilité et la localisation dans les aires urbaines.Trois étapes ont été préalables identifiées qui semblent pertinentes :- l'exploration théorique de l'émergence de comportements "stylisés" de rythmes temporels et de localisation d'activités à travers une "ville-modèle",- le couplage de modèles éprouvés dans les domaines respectifs du transport et de la localisation, en particulier les modèles applicables à des problèmes pratiques,- l'identification et la résolution des obstacles informatiques relatifs à la simulation, à la collecte des données et à l'analyse des résultats de ces modèles.modélisation multi-agents ; mobilité urbaine ; localisation des activités ; interactions localisations transport

    Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

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    Background Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded. Methods We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis. Findings Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis. Conclusion Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice

    A sustainable path for space science

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    High-performance scientific satellites are currently the exclusive domain of government-funded agencies. The team behind the Twinkle Space Mission is developing a new class of small and sustainable science satellites that leverages recent innovations in the commercial space sector

    Effects of comorbidities on quality of life in Filipino people with tuberculosis.

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    BACKGROUND: We investigated health-related quality of life (HrQoL) in Filipino people undergoing TB treatment, and whether HrQoL was negatively impacted by comorbidity with undernutrition, diabetes (DM) and anaemia.METHODS: Adult participants were enrolled in public facilities in Metro Manila (three sites) and Negros Occidental (two sites). Multivariate linear regression was used to model the four correlated domain scores from a WHOQOL-BREF questionnaire (physical, psychological, social, environmental). A forward-stepwise approach was used to select a final multivariable model with inclusion based on global tests of significance at P < 0.1.RESULTS: In 446 people on drug-susceptible TB treatment, DM and moderate/severe anaemia were not associated with HrQoL. After adjustment for age, sex, education, food insecurity, treatment adherence, inflammation, Category I or II TB treatment, treatment phase, current side effects and inhibited ability to work, moderate/severe undernutrition (body mass index < 17 kg/m²) was associated with lower HrQoL (P = 0.003) with reduced psychological (coefficient: -1.02, 95% CI -1.54 to -0.51), physical (-0.62, 95% CI -1.14 to -0.09) and environmental domain scores (-0.45, 95% CI -0.88 to -0.01). In 225 patients with known HIV status in Metro Manila, HIV was associated with modestly reduced HrQoL (P = 0.014).CONCLUSION: Nutritional status and food insecurity represent modifiable risk factors for poor HrQoL that may be alleviated through interventions
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