Interactions géomorphologiques et sédimentaires entre bassin versant et piémont alluvial. Modélisation numérique et exemples naturels dans les Andes

Les incisions d'un paysage, formant généralement des terrasses, sont interprétées comme les marqueurs de changements climatiques ou tectoniques passé, de variations de niveau de base ou de rétroactions propres au système. Cette thèse propose de préciser leur interprétation en étudiant un système montagne-piémont. Une étude utilisant le modèle numérique CIDRE, a montré que des incisions autogéniques (sans changement climatique ou tectonique) se développaient dans le système s'il existait un seuil de transport non négligeable et une condition aux limites aval correspondant à une rivière transversale. Les incisions se propagent de l'apex du piémont vers l'aval et vers l'apex de la montagne. Les rétroactions avec la montagne sont d'autant plus importantes que le piémont est long. Le couplage montagne-piémont induit une réponse simple ou complexe du système à un changement climatique selon l'intensité de ce dernier. L'étude de cas naturels a montré que les taux d'érosion actuels des bassins versants au Chili sont essentiellement contrôlés par les débits moyens et des seuils de couverture végétale et de pente moyenne. Le système montagne-piémont de Las Tunas (Sud de Mendoza, Argentine) est incisé en trois niveaux terrasses. La géométrie des terrasses et leur continuité depuis le piémont jusqu'à la Cordillère sont précisées par nos données GPS. Elles attestent des fortes interactions entre montagne et piémont. Les analyses 10Be montrent que les incisions sont reliées aux cycles glaciaires-interglaciaires. Enfin, les profils de 10Be versus profondeur montrent une remobilisation des terrasses (faiblement pentées et déconnectées) sur plus de deux mètres de profondeur.Climatic or tectonics changes, base level variation or natural feedbacks markers can be interpreted from terraces formed by landscapes entrenchments. This study provides improved entrenchment interpretation by focussing on a mountain catchments-foreland system. Two necessary conditions for permanent autogenic entrenchment (without climate or tectonic changes) in a catchment-fan system are defined using the CIDRE digital model. These include a significant transport threshold (critical shear stress) and a downstream boundary condition corresponding to a transversal river. The entrenchments propagate from the fan apex both upstream to mountain divides and downstream to the fan base. The strength of feedback with the mountain catchments is dependent on the size of the foreland. This relationship between mountain and foreland is responsible for simple or complex responses to the degree of climatic change perturbations. Natural cases studies show that the current erosion rates of Chilean catchments are essentially controlled by mean runoff rates combined with mean slope and plant cover thresholds. The mountain catchment-fan system of Las Tunas (Argentina) has been strongly entrenched in three main terraces levels. Terrace geometry and continuity from foreland to mountain have been detailed by our kinematic GPS study proving strong relationships between mountain and foreland. 10Be studies has revealed two significant results: (1) entrenchments are correlated glacial-interglacial cycles and (2) 10Be concentration versus depth profiles show that terrace remobilization (plane and disconnected surfaces) occurs down to two meters of depth

Amplitude of the rest–activity cycle in chronic obstructive pulmonary disease: an exploratory study

In chronic obstructive pulmonary disease (COPD), there is large individual variability in the progression of the disease. Low amplitude of rest–activity rhythms has been associated with worse prognosis in a variety of diseases, but it has not been investigated in COPD. The first aim of this exploratory study was to compare disease severity and prognosis indicators between COPD patients with relatively high or low amplitude of their rest–activity cycle, as measured with actigraphy. As a second objective, 24-hour profiles of both activity levels and nighttime-sleep quality were compared between the two subgroups to assess the relative contribution of day- and night-activity levels to high and low rest–activity rhythm amplitude in this population. Rest–activity rhythms were measured with 8–14 days of wrist actigraphy in 14 patients (nine men), aged 58–79 years, suffering from moderate-to-severe COPD. Relative amplitude of 24-hour activity profiles ranged from 0.72 to 0.98. Participants were divided at the median into high-amplitude (mean ± standard deviation 0.9±0.04) and low-amplitude (0.79±0.05) subgroups. There was no significant difference between the two subgroups for pulmonary function or exercise capacity. However, the low-amplitude group had more severe symptoms of dyspnea and worse prognostic scores than the high-amplitude group (P<0.05). The 24-hour activity profiles revealed higher levels of activity in the high-amplitude group for the 12–3 pm interval (P<0.05). There was no significant difference between the two groups for subjective or actigraphic estimates of sleep quality, sleep duration, or proportion of daytime sleep. This exploratory study is a first step toward the identification of larger rest–activity rhythm amplitude as a marker of better prognosis in COPD and as another potential target for exercise-based rehabilitation programs in this population

Using Continuous Data Tracking Technology to Study Exercise Adherence in Pulmonary Rehabilitation

Pulmonary rehabilitation is widely recognized in the management of respiratory diseases. A key component to successful pulmonary rehabilitation is adherence to the recommended exercise training. The purpose of the present protocol is to describe how continuous data tracking technology can be used to precisely measure adherence to a prescribed aerobic training intensity

Amplitude of the rest-activity cycle in chronic obstructive pulmonary disease: an exploratory study

In chronic obstructive pulmonary disease (COPD), there is large individual variability in the progression of the disease. Low amplitude of rest–activity rhythms has been associated with worse prognosis in a variety of diseases, but it has not been investigated in COPD. The first aim of this exploratory study was to compare disease severity and prognosis indicators between COPD patients with relatively high or low amplitude of their rest–activity cycle, as measured with actigraphy. As a second objective, 24-hour profiles of both activity levels and nighttime-sleep quality were compared between the two subgroups to assess the relative contribution of day- and night-activity levels to high and low rest–activity rhythm amplitude in this population. Rest–activity rhythms were measured with 8–14 days of wrist actigraphy in 14 patients (nine men), aged 58–79 years, suffering from moderate-to-severe COPD. Relative amplitude of 24-hour activity profiles ranged from 0.72 to 0.98. Participants were divided at the median into high-amplitude (mean ± standard deviation 0.9±0.04) and low-amplitude (0.79±0.05) subgroups. There was no significant difference between the two subgroups for pulmonary function or exercise capacity. However, the low-amplitude group had more severe symptoms of dyspnea and worse prognostic scores than the high-amplitude group (P<0.05). The 24-hour activity profiles revealed higher levels of activity in the high-amplitude group for the 12–3 pm interval (P<0.05). There was no significant difference between the two groups for subjective or actigraphic estimates of sleep quality, sleep duration, or proportion of daytime sleep. This exploratory study is a first step toward the identification of larger rest–activity rhythm amplitude as a marker of better prognosis in COPD and as another potential target for exercise-based rehabilitation programs in this population

Développement d'un cadre pour l'évaluation de la santé de la faune sauvage (un modèle conceptuel basé sur la notion "d'intelligence" pour la santé de la faune en vue de son utilisation pour le Sri Lanka Wildlife Health Centre)

LYON1-BU Santé (693882101) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF

The Economic Burden of Sleepy Driving

International audienc

Interactions géomorphologiques et sédimentaires entre bassin versant et piémont alluvial (modélisation numérique et exemples naturels dans les Andes)

TOULOUSE3-BU Sciences (315552104) / SudocTOULOUSE-Observ. Midi Pyréné (315552299) / SudocSudocFranceF

Adipose tissue (P)RR regulates insulin sensitivity, fat mass and body weight

Objective: We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance. Methods: An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. Results: KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR. Conclusions: (P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes. Keywords: (Pro)renin receptor, Renin-angiotensin system, Adipose tissue knock-out mice, Obesity, Adipose tissue, Insulin resistanc

Using Continuous Data Tracking Technology to Study Exercise Adherence in Pulmonary Rehabilitation

Pulmonary rehabilitation is widely recognized in the management of respiratory diseases. A key component to successful pulmonary rehabilitation is adherence to the recommended exercise training. The purpose of the present protocol is to describe how continuous data tracking technology can be used to precisely measure adherence to a prescribed aerobic training intensity