Vital status of pre-ART and ART patients defaulting from care in rural Malawi

OBJECTIVES: To ascertain the outcome of pre-Antiretroviral therapy (ART) and ART patients defaulting from care and investigate reasons for defaulting. METHODS: Patients defaulting from HIV care in Chiradzulu between July 2004 and September 2007 were traced at last known home address. Deaths and moves were recorded, and patients found alive were interviewed. Defaulting was defined as missed last appointment by more than 1 month among patients of unknown vital status. RESULTS: A total of 1637 individuals were traced (54%-88% of eligible), 981 pre-ART and 656 ART patients. Of 694 pre-ART patients found, 49% had died (51% of adults and 38% of children), a median of 47 days after defaulting, and 14% had moved away. Of 451 ART patients found, 54% had died (54% of adults and 50% of children), a median of 52 days after defaulting, and 20% had moved away. Overall, 221 patients were interviewed (90% of those found alive), 42% had worked outside the district in the previous year; 49% of pre-ART and 19% of ART patients had not disclosed their HIV status to other household members. Main reasons for defaulting were stigma (43%), care dissatisfaction (34%), improved health (28%) and for ART discontinuation, poor understanding of disease or treatment (56%) and drug side effects (42%). CONCLUSION: This study in a rural African HIV programme reveals the dynamics related to health service access and use, and it provides information to correct programme mortality estimates for adults and children

Bioinspired Electro-Thermo-Hygro Reversible Shape-Changing Materials by 4D Printing

International audienceHygromorph composites are moisture-induced shape-changing materials that are increasingly studied to develop autonomously actuated deployable structures. The morphing mechanism is based on the high affinity for moisture and the hygroexpansive nature of at least one component, combined with a bilayer microstructure. Among available hygromorphs, those consisting of cellulosic or hydrogel material-based actuators trigger fast responses to moisture. Their stiffness however decreases significantly with the moisture content and that restricts their potential application as soft actuators. This work proposes a novel 4D printed multistimuli-responsive structural material based on conductive carbon reinforcements and combined with a moisture sensitive polymer. These 4D printed materials possess a microstructure that provides the capability of natural actuators like pine cones. The actuation of these functional materials could be either triggered passively by the variation of the ambient moisture, or by electroheating, with the latter leading to the control of the moisture content in initially wet samples via Joule effects. This new class of functional materials shows an increase of the actuation speed by a factor 10 compared to other existing hygromorphs with the same responsiveness. When the electrical heating is turned off, passive cooling and moisture driven actuation is triggered in a full reversible mode

Games Where You Can Play Optimally with Arena-Independent Finite Memory

For decades, two-player (antagonistic) games on graphs have been a framework of choice for many important problems in theoretical computer science. A notorious one is controller synthesis, which can be rephrased through the game-theoretic metaphor as the quest for a winning strategy of the system in a game against its antagonistic environment. Depending on the specification, optimal strategies might be simple or quite complex, for example having to use (possibly infinite) memory. Hence, research strives to understand which settings allow for simple strategies. In 2005, Gimbert and Zielonka provided a complete characterization of preference relations (a formal framework to model specifications and game objectives) that admit memoryless optimal strategies for both players. In the last fifteen years however, practical applications have driven the community toward games with complex or multiple objectives, where memory -- finite or infinite -- is almost always required. Despite much effort, the exact frontiers of the class of preference relations that admit finite-memory optimal strategies still elude us. In this work, we establish a complete characterization of preference relations that admit optimal strategies using arena-independent finite memory, generalizing the work of Gimbert and Zielonka to the finite-memory case. We also prove an equivalent to their celebrated corollary of great practical interest: if both players have optimal (arena-independent-)finite-memory strategies in all one-player games, then it is also the case in all two-player games. Finally, we pinpoint the boundaries of our results with regard to the literature: our work completely covers the case of arena-independent memory (e.g., multiple parity objectives, lower- and upper-bounded energy objectives), and paves the way to the arena-dependent case (e.g., multiple lower-bounded energy objectives).Comment: Updated title, full version of CONCUR 2020 conference pape

The 2008-2009 outburst of the young binary system Z CMa unraveled by interferometry with high spectral resolution

Z CMa is a young binary system consisting of an Herbig primary and a FU Ori companion. Both components seem to be surrounded by active accretion disks and a jet was associated to the Herbig B0. In Nov. 2008, K. Grankin discovered that Z CMa was exhibiting an outburst with an amplitude larger than any photometric variations recorded in the last 25 years. To study the innermost regions in which the outburst occurs and understand its origin, we have observed both binary components with AMBER/VLTI across the Br{\gamma} emission line in Dec. 2009 in medium and high spectral resolution modes. Our observations show that the Herbig Be, responsible for the increase of luminosity, also produces a strong Br{\gamma} emission, and they allow us to disentangle from various origins by locating the emission at each velocities through the line. Considering a model of a Keplerian disk alone fails at reproducing the asymmetric spectro-astrometric measurements, suggesting a major contribution from an outflow.Comment: To be published in the proceedings of the SPIE'2010 conference on "Optical and Infrared Interferometry II

Natural fibres actuators for smart bio-inspired hygromorph biocomposites

International audienceHygromorph biocomposite (HBC) actuators make use of the transport properties of plant fibres to generate an out-of-plane displacement when a moisture gradient is present. HBC actuators possess a design based on the bilayer configuration of natural hygromorph actuators (like pine cone, wheat awn, Selaginella lepidophyll). In this work we present a series of design guidelines for HBCs with improved performance, low environmental footprints and high durability in severe environments. We develop a theoretical actuating response (curvature) formulation of maleic anhydride polypropylene (MAPP)/plant fibres based on bimetallic actuators theory. The actuation response is evaluated as a function of the fibre type (flax, jute, kenaf and coir). We demonstrate that the actuation is directly related to the fibre microstructure and its biochemical composition. The jute and flax fibres appear to be the best candidates for use in HBCs. Flax/MAPP and jute/MAPP HBCs exhibit similar actuating behaviours during the sorption phase (amplitude and speed), but different desorption characteristics due to the combined effect of the lumen size, fibre division and biochemical composition on the desorption mechanism. During hygromechanical fatigue tests the jute/MAPP HBCs exhibit a drastic improvement in durability compared to their flax counterparts. We also provide a demonstration on how HBCs can be used to trigger deployment of more complex structures based on Origami and Kirigami designs

Games Where You Can Play Optimally with Arena-Independent Finite Memory

For decades, two-player (antagonistic) games on graphs have been a framework of choice for many important problems in theoretical computer science. A notorious one is controller synthesis, which can be rephrased through the game-theoretic metaphor as the quest for a winning strategy of the system in a game against its antagonistic environment. Depending on the specification, optimal strategies might be simple or quite complex, for example having to use (possibly infinite) memory. Hence, research strives to understand which settings allow for simple strategies. In 2005, Gimbert and Zielonka provided a complete characterization of preference relations (a formal framework to model specifications and game objectives) that admit memoryless optimal strategies for both players. In the last fifteen years however, practical applications have driven the community toward games with complex or multiple objectives, where memory -- finite or infinite -- is almost always required. Despite much effort, the exact frontiers of the class of preference relations that admit finite-memory optimal strategies still elude us. In this work, we establish a complete characterization of preference relations that admit optimal strategies using arena-independent finite memory, generalizing the work of Gimbert and Zielonka to the finite-memory case. We also prove an equivalent to their celebrated corollary of great practical interest: if both players have optimal (arena-independent-)finite-memory strategies in all one-player games, then it is also the case in all two-player games. Finally, we pinpoint the boundaries of our results with regard to the literature: our work completely covers the case of arena-independent memory (e.g., multiple parity objectives, lower- and upper-bounded energy objectives), and paves the way to the arena-dependent case (e.g., multiple lower-bounded energy objectives)

Development of standardized method for the determination of the degradation of nitric oxide (NO) in the air by photocatalytic materials: Inter-laboratory validation tests

International audienceThe need of a uniform experimental procedure for assessing the performance of photocatalytic inorganic materials contained in building materials led the European Committee for Standardization (CEN/TC386/WG2) to elaborate a Technical Specification (TS).Taking into consideration the importance of the effects which will be of possible variations in the implementation of the reference method, parallel photocatalytic tests according to the TS were performed in the current study. 6 European labs were participated in an inter-laboratory exercise where the experiments had to be done in a special design CEN reactor using LED system. The experimental procedure and conditions were taken from the draft TS and were referred to the average irradiance, inlet NO & NO 2 concentration, T o C and RH inside the reactor, flow and reactor net volume. Identical photocatalytic samples were provided to all participants. The results obtained from the 6 labs showed a variation between 18% and 31% on the photocatalytic NO conversion while the mean value was 26%. The corresponding photocatalytic rate was ranged between 2600 μg/m 2 h and 4100 μg/m 2 h presenting a mean value of 3400 μg/m 2 h. The homogeneity of the lamp and the homogeneity of the deposition of TiO 2 are the main factors impacting the results

Dynamic study of blood-brain barrier closure after its disruption using ultrasound: a quantitative analysis.

International audienceDelivery of therapeutic or diagnostic agents to the brain is majorly hindered by the blood-brain barrier (BBB). Recently, many studies have demonstrated local and transient disruption of the BBB using low power ultrasound sonication combined with intravascular microbubbles. However, BBB opening and closure mechanisms are poorly understood, especially the maximum gap that may be safely generated between endothelial cells and the duration of opening of the BBB. Here, we studied BBB opening and closure under magnetic resonance (MR) guidance in a rat model. First, MR contrast agents (CA) of different hydrodynamic diameters (1 to 65 nm) were employed to estimate the largest molecular size permissible across the cerebral tissues. Second, to estimate the duration of the BBB opening, the CA were injected at various times post-BBB disruption (12 minutes to 24 hours). A T(1) mapping strategy was developed to assess CA concentration at the ultrasound (US) focal point. Based on our experimental data and BBB closure modeling, a calibration curve was obtained to compute the half closure time as a function of CA hydrodynamic diameter. These findings and the model provide an invaluable basis for optimal design and delivery of nanoparticles to the brain