Rencontre de la science de l'information géographique et de l'anthropologie culturelle:modélisation spatiale et représentation de phénomènes culturels

Geographical Information Science and Cultural Anthropology are aimed to collaborate on development projects dedicated to indigenous communities. This fact is first based on a growing intention to integrate the reality and the perception of the development owned by the community. This movement, towards a stronger consideration of the community's point of view, is assigning to the anthropologist with a central importance in projects. He plays a leading part in linking the culture and the scientific disciplines involved in a project. Secondly, the geographic space, the community is evolving in, has its own organization and functioning. The recognized importance of space therefore implies the participation of the geographical information science specialist. The "rapprochement" of those disciplines with distant epistemologies constitutes the context of this study. At first sight, the use of a geographical information system by an anthropologist appears to be limited to the introduction of a new tool. For the specialist in geographical information science, the adaptation of the anthropological knowledge to the logic of the information systems seems to be a common problem of data structuring, analysis and mapping. The attempts of rapprochement to date aren't particularly successful. Their analysis brought us to formulate a statement of fact summarized in this research by the complexity versus simplicity paradox. The interaction between the two disciplines, given a concrete expression by the confrontation of their epistemologies, is at the origin of new problems and questions. Some of them are complex as this study shows. This research results corresponds to a twofold proposal for collaboration approaches. First, an innovative approach of modelling the anthropological knowledge in geographical information science is suggested. This approach introduces the concept of "knowledge model", dialogue object between the disciplines. Its establishment precedes the one of the conceptual data model. Second, an approach is developed for the conception of a visual and interactive interface. This computerized framework is set up in order to support interdisciplinary communication. Moreover, it allows products of the geographical information science to be accessible to the anthropologists. The pertinence and the reliability of the suggested approaches are established in terms of adequacy to the logic of each discipline, and of integration to the development projects. The associated contributions and limits are finally discussed, leading to some future prospects

Elaboration et caractérisation de structures métal-isolant-métal à base de TiO2 déposé par Atomic Layer Deposition

The requirements for future dynamic random access memory (DRAM) capacitors are summarized in the International Technology Roadmap for Semiconductors. For sub-22 nm node, performances like equivalent oxide thickness (EOT) < 0.5 nm and leakage current density < 1.10-7 A/cm² at 0.8 V are required but are difficult to meet. Titanium dioxide (TiO2) is an attractive dielectric material for such application regarding its high dielectric constant (k). Depending on its growth conditions, TiO2 can be prepared in amorphous, anatase or rutile phase. From the structural point of view, it is generally preferred that TiO2 remains amorphous throughout a complete technological process to minimize leakage transport along grain boundaries. However, the rutile phase exhibits very high dielectric constant ranging from 90 to 170, depending on the lattice orientation. Due to this high dielectric constant, TiO2 rutile phase is considered as a promising material for capacitors in future generations of Dynamic Random Access Memories (DRAMs). A key issue is how to control the high leakage current of rutile phase while keeping the highest dielectric constant in order to get the best electrical performances. In this work, we investigate the growth of high dielectric constant rutile TiO2 films in Metal - Insulator - Metal (MIM) structures deposited on different substrates such as RuO2/Ru or Pt electrodes using ALD (Atomic Layer Deposition). A study of physico-chemical properties of TiO2 layer and influence of bottom electrodes on TiO2's crystalline structure is proposed. Different compositions of dielectrics are processed using flexibility of ALD deposition technique, including Al-doped TiO2 layers and pure TiO2 layers. Electrical properties in terms of leakage current or capacitance density of MIM structures embedding that kind of dielectrics and comparison between these MIM structures in terms of electrical performances is proposed in order to determine the best dielectric film composition to meet the requirements for next generation of DRAM capacitors.Les besoins de la microélectronique pour les condensateurs de type DRAM sont résumés dans la feuille de route ITRS (International Technology Roadmap for Semiconductors). Pour descendre en dessous du noeud technologique 22 nm, des performances électriques telles qu'une épaisseur d'oxyde équivalent (EOT) < 0.5 nm et un niveau de courant de fuite < 1.10-7 A/cm² à 0.8 V sont nécessaires. Ces performances sont difficiles à atteindre si l'on considère des oxydes standards largement utilisés tels que le SiO2, le Si3N4 ou l'Al2O3. Le dioxyde de Titane constitue un matériau diélectrique de choix pour ce type d'application si l'on considère sa forte constante diélectrique, la plus haute des oxydes binaires. Selon les conditions de croissance de la couche de TiO2, celle-ci peut se présenter sous forme amorphe ou posséder une structure cristalline appelé phase anatase ou phase rutile. Cette dernière présente une très forte constante diélectrique (90 à 170 selon l'orientation de la maille cristalline) et en fait un atout indéniable pour le développement de condensateur DRAM. Toutefois, cette phase rutile est aussi à l'origine d'un fort courant de fuite mesuré à partir des structures Métal - Isolant - Métal (MIM) associées. De ce fait, il est primordial de savoir contrôler ces courants de fuite tout en gardant la forte valeur de constante diélectrique de la phase rutile. Dans ce travail, nous proposons de travailler sur la croissance des couches minces de TiO2 intégrées dans des structures MIM et déposées sur des substrats différents tels que des électrodes de RuO2/Ru ou de Pt. La technique de dépôt employée pour les couches minces de TiO2 est la technique ALD pour son contrôle très précis de l'épaisseur déposée et sa souplesse d'utilisation pour ce type d'applications. Les propriétés physico-chimiques des couches de TiO2 et l'influence du substrat sur ces propriétés sont analysées. Des compositions différentes de diélectriques sont élaborées au moyen de la technique de dépôt par ALD et notamment des couches minces de TiO2 dopés à l'aluminium. Les propriétés électriques de ces couches sont étudiées afin de déterminer les performances électriques des structures MIM associées en termes de courant de fuite et de densité capacitive

Postnikov invariants of H-spaces

It is known that the order of all Postnikov k-invariants of an H-space of finite type is finite. This paper establishes the finiteness of the order of the k-invariants $k^{m+1}(X)$ of X in dimensions m ≤ 2n if X is an (n-1)-connected H-space which is not necessarily of finite type (n ≥ 1). Similar results hold more generally for higher k-invariants if X is an iterated loop space. Moreover, we provide in all cases explicit universal upper bounds for the order of the k-invariants of X

Atomic layer deposition: Low temperature process well adapted to ULSI and TFT technologies

The high k dielectrics is an important materials to be integrate in future Ultra Large Scale Integration (ULSI) and future TFT technology. Indeed, to keep on the Moore\u27s Law curve, the reduction of silicon oxide (SiO2) thickness still required, but this reduction is hindered by tunneling current leakage limit. Consequently, it is important to replace SiO2 by another materials with high dielectric constant. The use of this material in manufacturing of gate dielectric in Thin-film transistor (TFT) and in Complementary Metal Oxide Semiconductor (CMOS) will increase gate capacitance with maintaining a low leakage current. Titanium dioxide is a good candidate due to its high dielectric constant in its rutile crystalline phase (180).This rutile structure is obtained at low temperature (250°C) by ALD deposition when TiO2 is deposited on ruthenium dioxide (RuO2) layer thanks to the small lattice mismatch between these two materials

A biomarker of brain arousal mediates the intergenerational link between maternal and child post-traumatic stress disorder.

This study examined whether there is a biological basis in the child's resting brain activity for the intergenerational link between maternal interpersonal violence-related posttraumatic stress disorder (IPV-PTSD) and child subclinical symptoms. We used high-density EEG recordings to investigate the resting brain activity in a sample of 57 children, 34 from mothers with IPV-PTSD, and 23 from mothers without PTSD. These children were part of a prospective, longitudinal study focusing on the offspring of mothers with and without IPV-PTSD, reporting how the severity of a mother's IPV-PTSD can impact her child's emotional regulation and risk for developing mental illness. However, we had not yet looked into potential EEG biomarkers during resting state that might mediate and/or moderate effects of maternal IPV-PTSD severity on child mental health, and in particular the risk for PTSD. The alpha band spectral power as well as the aperiodic exponent of the power spectrum (PLE; power-law exponent) were examined as mediators of maternal IPV-PTSD and child PTSD. While there was no difference in alpha spectral power between the two groups, PLE was significantly reduced in children of mothers with IPV-PTSD compared to control children, indicating cortical hyper-arousal. Interestingly, child PLE was negatively correlated with the severity of maternal IPV-PTSD, suggesting an intergenerational interaction. This interpretation was reinforced by a negative correlation between child PLE and child PTSD symptoms. Finally, causal analyses using structural equation modelling indicated that child PLE mediated the relationship between maternal PTSD severity and child PTSD. Our observations suggest that maternal IPV-PTSD has an intergenerational impact on the child neurobehavioral development through a correlated abnormal marker of brain arousal (i.e. child PLE). These findings are potentially relevant to psychotherapy research and to the development of more effective psycho-neurobehavioral therapies (i.e. neurofeedback) among affected individuals

Associations Between Maternal Post-traumatic Stress Disorder and Traumatic Events With Child Psychopathology: Results From a Prospective Longitudinal Study.

Introduction: Exposure to interpersonal violence (IPV) can lead to post-traumatic stress disorder (PTSD) in mothers, and in turn adversely affect the mother-child relationship during early development, as well as the mental health of their children. Our objectives are to assess: (1) the association of maternal IPV-PTSD to child psychopathology, (2) the association of maternal IPV independently of PTSD to child psychopathology, and (3) the relationship between child exposure to violence to the psychopathology of these children. Methods: We used data from the longitudinal Geneva Early Childhood Stress Project. The sample included 64 children [mean age at Phase 1 = 2.4 (1.0-3.7) years] of mothers with or without IPV-PTSD. Data on mothers was collected during Phase 1, using the Clinical Administered PTSD Scale (CAPS), the Brief Physical and Sexual Abuse Questionnaire (BPSAQ) and the Conflict Tactics Scale (CTS2). Modules of a semi-structured diagnostic interview, and the Violence Exposure Scale were used to collect information on child at Phase 2, when children were older [mean age = 7.02 (4.7-10)]. Results: A higher CAPS score in mothers when children were toddler-age was associated with an increased risk of symptoms of attention deficit/hyperactivity disorder (ADHD; β = 0.33, p = 0.014) and PTSD in school-age children. The association between maternal IPV-PTSD and child PTSD (β = 0.48, p &lt; 0.001) symptoms remained significant after adjustment for potential confounders. Among children, exposure to violence was associated with an increased risk of symptoms of generalized anxiety (β = 0.37, p = 0.006), major depressive (β = 0.24, p = 0.039), ADHD (β = 0.27, p = 0.040), PTSD (β = 0.52, p &lt; 0.001), conduct (β = 0.58, p = 0.003) and oppositional defiant (β = 0.34, p = 0.032) disorders. Conclusion: Our longitudinal findings suggest that maternal IPV-PTSD during the period of child development exert an influence on the development of psychopathology in school-aged children. Mothers' IPV was associated with child psychopathology, independently of PTSD. Child lifetime exposure to violence had an additional impact on the development of psychopathology. Careful evaluation of maternal life-events is essential during early childhood to reduce the risk for the development of child psychopathology. Early efforts to curb exposure to violence in children and early intervention are both needed to reduce further risk for intergenerational transmission of trauma, violence, and related psychopathology

On the complex and dimensional relationship of maternal PTSD during early childhood and child outcomes at school-age.

Several studies have shown associations between maternal interpersonal violence-related posttraumatic stress disorder (PTSD), child mental health problems, and impaired socioemotional development. However, the existing literature lacks evidence linking constellations of risk factors such as maternal interpersonal-violence-related PTSD, psychopathology, and interactive behavior with toddlers and outcome measures at school-age. This study involved a prospective, longitudinal investigation of 62 mothers and examined the relationship between maternal variables measured when children were in early childhood (mean age 27 months), and child outcomes when children were school-age (age mean = 83.2 months) while retaining a focus on the context of maternal PTSD. To identify and weigh associated dimensions comparatively, we employed sparse canonical correlation analysis (sCCA) aimed at associating dimensions of a dataset of 20 maternal variables in early childhood with that of more than 20 child outcome variables (i.e., child psychopathology, life-events, and socioemotional skills) at school-age. Phase 1 variables with the highest weights were those of maternal psychopathology: PTSD, depressive and dissociative symptoms, and self-report of parental stress. The highest weighted Phase 2 child outcome measures were those of child psychopathology: PTSD, anxiety, and depressive symptoms as well as peer bullying and victimization. sCCA revealed that trauma-related concepts in mothers were significantly and reliably associated with child psychopathology and other indicators of risk for intergenerational transmission of violence and victimization. The results highlight the dimensional and multifaceted nature-both for mothers as well as children-of the intergenerational transmission of violence and associated psychopathology