Soudure directe silicium sur silicium (étude de procédés de passivation de l'interface)

Ces travaux de thèse accompagnent le développement de nouvelles architectures d interrupteurs monolithiques bidirectionnels en courant et en tension. L une des voies technologiques proposées consiste à contrôler les propriétés électriques de l interface de soudure Si-Si. Nous avons mis en évidence la nature complexe de l activité électrique de l interface avec l existence d un continuum d états d énergie au caractère recombinant. L intégration d une telle brique technologique nécessite alors la maîtrise de la passivation/décoration de l interface par diffusion d impuretés. La passivation des états d interfaces par hydrogénation a montré une amélioration des propriétés électriques globales de l interface de soudure avec une réduction de la dispersion des paramètres électriques. Une contamination contrôlée par diffusion de platine, nous a permis d obtenir une désactivation, voire une compensation, du phosphore à l interface, accompagnée d une disparition des niveaux profonds.1-lydrophobic silicon direct wafer bonding is an interesting way to realize new devices, espccia1lhen it could substitutc for double-side lithography or give access tu buried layers during process. This study goes with the design of a monolithic switch bidirectional in current and voltage for household appliances. We investigate the electrical properties of hydrophobic silicon wafer bonded interface. We have shown the interface is composed of several electronic defects, due to lattice deformations and residual contaminations, generating deep levels with recombinant properties. Finally, this study is focused on its electrical characterization and how to control its electrical activity. Hydrogenation and platinum diffusion are performed at Iow temperature and underline the possibility to restore the phosphorus biilk doping level. Therefore, an appropriate thermal treatment could be used to passivate a bonded interface without any bulk contamination.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

Incentivizing school attendance in the presence of parent-child information frictions

Education conditional cash transfer programs may increase school attendance in part due to the information they transmit to parents about their child's attendance. This paper presents experimental evidence that the information content of an education conditional cash transfer program, when given to parents independently of any transfer, can have a substantial effect on school attendance. The effect is as large as 75 percent of the effect of a conditional cash transfer incentivizing parents, and not significantly different from it. In contrast, a conditional transfer program incentivizing children instead of parents is nearly twice as effective as an "information only" treatment providing the same information to parents about their child's attendance. Taken together, these results suggest that children have substantial agency in their schooling decisions. The paper replicates the findings from most evaluations of conditional cash transfers that gains in attendance achieved by incentivizing parents financially do not translate into gains in test scores. But it finds that both the information only treatment and the alternative intervention incentivizing children substantially improve math test scores

ScenaLand: a simple methodology for developing land use and management scenarios

Scenarios serve science by testing the sensitivity of a system and/or society to adapt to the future. In this study, we present a new land use scenario methodology called ScenaLand. This methodology aims to develop plausible and contrasting land use and management (LUM) scenarios, useful to explore how LUM (e.g. soil and water conservation techniques) may afect ecosystem services under global change in a wide range of environments. ScenaLand is a method for constructing narrative and spatially explicit land use scenarios that are useful for end-users and impact modellers. This method is innovative because it merges literature and expert knowledge, and its low data requirement makes it easy to be implemented in the context of inter-site comparison, including global change projections. ScenaLand was developed and tested on six diferent Mediterranean agroecological and socioeconomic contexts during the MASCC research project (Mediterranean agricultural soil conservation under global change). The method frst highlights the socioeconomic trends of each study site including emerging trends such as new government laws, LUM techniques through a qualitative survey addressed to local experts. Then, the method includes a ranking of driving factors, a matrix about land use evolution, and soil and water conservation techniques. ScenaLand also includes a framework to develop narratives along with two priority axes (contextualized to environmental protection vs. land productivity in this study). In the context of this research project, four contrasting scenarios are proposed: S1 (business-as-usual), S2 (market-oriented), S3 (environmental protection), and S4 (sustainable). Land use maps are then built with the creation of LUM allocation rules based on agroecological zoning. ScenaLand resulted in a robust and easy method to apply with the creation of 24 contrasted scenarios. These scenarios come not only with narratives but also with spatially explicit maps that are potentially used by impact modellers and other endusers. The last part of our study discusses the way the method can be implemented including a comparison between sites and the possibilities to implement ScenaLand in other contexts.info:eu-repo/semantics/publishedVersio

Survival and consciousness recovery are better in the minimally conscious state than in the vegetative state

BACKGROUND The prognosis value of early clinical diagnosis of consciousness impairment is documented by an extremely limited number of studies, whereas it may convey important information to guide medical decisions. OBJECTIVE We aimed at determining if patients diagnosed at an early stage (<90 days after brain injury) as being in the minimally conscious state (MCS) have a better prognosis than patients in the vegetative state/Unresponsive Wakefulness syndrome (VS/UWS), independent of care limitations or withdrawal decisions. METHODS Patients hospitalized in ICUs of the Pitié-Salpêtrière Hospital (Paris, France) from November 2008 to January 2011 were included and evaluated behaviourally with standardized assessment and with the Coma Recovery Scale-Revised as being either in the VS/UWS or in the MCS. They were then prospectively followed until 1July 2011 to evaluate their outcome with the GOSE. We compared survival function and outcomes of these two groups. RESULTS Both survival function and outcomes, including consciousness recovery, were significantly better in the MCS group. This difference of outcome still holds when considering only patients still alive at the end of the study. CONCLUSIONS Early accurate clinical diagnosis of VS/UWS or MCS conveys a strong prognostic value of survival and of consciousness recovery

Characterization of greater middle eastern genetic variation for enhanced disease gene discovery

The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Silicon direct water bonding : study of passivation processes of the interface

Ces travaux de thèse accompagnent le développement de nouvelles architectures d’interrupteurs monolithiques bidirectionnels en courant et en tension. L’une des voies technologiques proposées consiste à contrôler les propriétés électriques de l’interface de soudure Si-Si. Nous avons mis en évidence la nature complexe de l’activité électrique de l’interface avec l’existence d’un continuum d’états d’énergie au caractère recombinant. L’intégration d’une telle brique technologique nécessite alors la maîtrise de la passivation/décoration de l’interface par diffusion d’impuretés. La passivation des états d’interfaces par hydrogénation a montré une amélioration des propriétés électriques globales de l’interface de soudure avec une réduction de la dispersion des paramètres électriques. Une contamination contrôlée par diffusion de platine, nous a permis d’obtenir une désactivation, voire une compensation, du phosphore à l’interface, accompagnée d’une disparition des niveaux profonds.1-lydrophobic silicon direct wafer bonding is an interesting way to realize new devices, espccia1lhen it could substitutc for double-side lithography or give access tu buried layers during process. This study goes with the design of a monolithic switch bidirectional in current and voltage for household appliances. We investigate the electrical properties of hydrophobic silicon wafer bonded interface. We have shown the interface is composed of several electronic defects, due to lattice deformations and residual contaminations, generating deep levels with recombinant properties. Finally, this study is focused on its electrical characterization and how to control its electrical activity. Hydrogenation and platinum diffusion are performed at Iow temperature and underline the possibility to restore the phosphorus biilk doping level. Therefore, an appropriate thermal treatment could be used to passivate a bonded interface without any bulk contamination

Observations of Macroporous Gallium Nitride Electrochemically Etched from High Doped Single Crystal Wafers in HF Based Electrolytes

International audienceIn this paper, we present a process to produce porous structures by electrochemical etching of highly doped n-type GaN single crystals in aqueous HF solutions. At first, we show that we are able to perform well oriented macropores from 30% HF based solutions. To our knowledge, it's the first time that this morphology is observed in porous GaN. These macropores grow from a 5 μm thick mesoporous layer observable at the sample surface. No significant difference in term of morphology is visible for etching on Ga or N face. Moreover, the influence of the HF concentration on the morphology is also discussed