Developmental regulation of the aldolase A muscle-specific promoter during in vivo muscle maturation is controlled by a nuclear receptor binding element.

During the post-natal period, skeletal muscles undergo important modifications leading to the appearance of different types of myofibers which exhibit distinct contractile and metabolic properties. This maturation process results from the activation of the expression of different sets of contractile proteins and metabolic enzymes, which are specific to the different types of myofibers. The muscle-specific promoter of the aldolase A gene (pM) is expressed mainly in fast-twitch glycolytic fibers in adult body muscles. We investigate here how pM is regulated during the post-natal development of different types of skeletal muscles (slow or fast-twitch muscles, head or body muscles). We show that pM is expressed preferentially in prospective fast-twitch muscles soon after birth; pM is up-regulated specifically in body muscles only later in development. This activation pattern is mimicked by a transgene which comprises only the 355 most proximal sequences of pM. Within this region, we identify a DNA element which is required for the up-regulation of the transgene during post-natal development in body muscles. Comparison of nuclear M1-binding proteins from young or adult body muscles show no qualitative differences. Distinct M1-binding proteins are present in both young and adult tongue nuclear extracts, compared to that present in gastrocnemius extracts.     

Multiscale Morphological and Electrical Characterization of Charge Transport Limitations to the Power Performance of Positive Electrode Blends for Lithium‐Ion Batteries

In this work, exhaustive characterizations of 3D geometries of LiNi_1/3Mn_1/3Co_1/3O₂ (NMC), LiFePO₄ (LFP), and NMC/LFP blended electrodes are undertaken for rational interpretation of their measured electrical properties and electrochemical performance. X‐ray tomography and focused ion beam in combination with scanning electron microscopy tomography are used for a multiscale analysis of electrodes 3D geometries. Their multiscale electrical properties are measured by using broadband dielectric spectroscopy. Finally, discharge rate performance are measured and analyzed by simple, yet efficient methods. It allows us to discriminate between electronic and ionic wirings as the performance limiting factors, depending on the discharge rate. This approach is a unique exhaustive analysis of the experimental relationships between the electrochemical behavior, the transport properties within the electrode, and its 3D geometry.     

Trends in Child Overweight Rates and Energy Intake in France From 1999 to 2007: Relationships With Socioeconomic Status

Our objectives were (i) to assess the current prevalence of childhood overweight (including obesity) (OWOB) in France and its relationship with comprehensive socioeconomic status (SES) indicators and (ii) to examine trends in OWOB prevalence and changes in energy intake (EI) and sedentary behavior (SED) based on the previous INCA 1 (Individuelle Nationale des Consommations Alimentaires) data (1998–1999). A representative sample of children aged 3–14 (n = 1,030) was taken from the 2006–2007 cross‐sectional INCA 2 food consumption survey. Weight and height were measured. The prevalence of OWOB was estimated according to the IOTF (International Obesity Task Force) definition. Average daily EI was evaluated using a 7‐day food record. SED (screen time) and SES were reported by answering questionnaires. SES indicators included the occupation and level of education of the head of the household (HH), and variables describing household wealth. Composite indices of SES were computed by correspondence analysis, and relationships with OWOB were explored by logistic regression analysis. In total, 14.5% (95% CI: 12.1–17.0) of the children were OWOB. All SES indicators were inversely correlated to OWOB. Average EI was equal to 1,739 kcal/day. Daily, children spent 113.5 min watching television, and 38.5 min playing video games or using a computer. Compared to the INCA 1 study, OWOB prevalence was not significantly different, EI was lower, and SED was higher. These trends were the same across all occupational categories of heads of household. Although overall rates of childhood OWOB are currently stabilizing, no change was observed in the strong inverse socioeconomic gradient of OWOB between the two studies.     

Mathematical modeling of pulmonary tuberculosis therapy: Insights from a prototype model with rifampin

There is a critical need for improved and shorter tuberculosis (TB) treatment. Current in vitro models of TB, while valuable, are poor predictors of the antibacterial effect of drugs in vivo. Mathematical models may be useful to overcome the limitations of traditional approaches in TB research. The objective of this study was to set up a prototype mathematical model of TB treatment by rifampin, based on pharmacokinetic, pharmacodynamic and disease submodels.The full mathematical model can simulate the time-course of tuberculous disease from the first day of infection to the last day of therapy. Therapeutic simulations were performed with the full model to study the antibacterial effect of various dosage regimens of rifampin in lungs.The model reproduced some qualitative and quantitative properties of the bactericidal activity of rifampin observed in clinical data. The kill curves simulated with the model showed a typical biphasic decline in the number of extracellular bacteria consistent with observations in TB patients. Simulations performed with more simple pharmacokinetic/pharmacodynamic models indicated a possible role of a protected intracellular bacterial compartment in such a biphasic decline.This modeling effort strongly suggests that current dosage regimens of RIF may be further optimized. In addition, it suggests a new hypothesis for bacterial persistence during TB treatment.     

Balancing the costs of carbon gain and water transport: testing a new theoretical framework for plant functional ecology

A novel framework is presented for the analysis of ecophysiological field measurements and modelling. The hypothesis ‘leaves minimise the summed unit costs of transpiration and carboxylation’ predicts leaf‐internal/ambient CO₂ ratios (c_i/c_a) and slopes of maximum carboxylation rate (V_cmax) or leaf nitrogen (N_area) vs. stomatal conductance. Analysis of data on woody species from contrasting climates (cold‐hot, dry‐wet) yielded steeper slopes and lower mean c_i/c_a ratios at the dry or cold sites than at the wet or hot sites. High atmospheric vapour pressure deficit implies low c_i/c_a in dry climates. High water viscosity (more costly transport) and low photorespiration (less costly photosynthesis) imply low c_i/c_a in cold climates. Observed site‐mean c_i/c_a shifts are predicted quantitatively for temperature contrasts (by photorespiration plus viscosity effects) and approximately for aridity contrasts. The theory explains the dependency of c_i/c_a ratios on temperature and vapour pressure deficit, and observed relationships of leaf δ¹³C and N_area to aridity.