In many organisms, the circadian clock is composed of functionally coupled morning and evening oscillators. In Arabidopsis, oscillator coupling relies on a core loop in which the evening oscillator ...component TIMING OF CAB EXPRESSION 1 (TOC1) was proposed to activate a subset of morning-expressed oscillator genes. Here, we show that TOC1 does not function as an activator but rather as a general repressor of oscillator gene expression. Repression occurs through TOC1 rhythmic association to the promoters of the oscillator genes. Hormone-dependent induction of TOC1 and analysis of RNA interference plants show that TOC1 prevents the activation of morning-expressed genes at night. Our study overturns the prevailing model of the Arabidopsis circadian clock, showing that the morning and evening oscillator loops are connected through the repressing activity of TOC1.
•Simple and accurate magnetic hysteresis static model.•Loss surface dynamic and static model.•Reliable representation of ferromagnetic materials behaviors.•Field decomposition applied in magnetic ...hysteresis modelling.•Unit differential reversal curve concept.
Hysteresis models allow the prediction of iron losses in materials under complex magnetic excitation, with accuracy depending on their principle and identification procedure. Commonly, to achieve high accuracy, a model may require a broad set of experimental input data, which is in some cases, not easy to obtain. We propose, in this study, a static model focusing on simplicity while still striving for accuracy. Its principle is to represent the variation of the field deviation between reversal curves and a near saturation hysteresis loop. In terms of input data, this model requires the experimental first magnetization curve and a few quasi-static centered hysteresis loops of the material. Following the principle description, the identification procedure, the model validation, as well as a sensitivity study are presented in detail.
The geothermal field of Bouillante (Guadeloupe, FWI) is a high-enthalpy hydrothermal system emplaced in submarine volcanoclastic formations (hyaloclastites, scarce lava flows) and subaerial ...formations (andesitic lava flows, pyroclastites, lahars) which belong to the Lesser Antilles arc. Three directional wells were drilled in 2001 to optimize the productivity of the geothermal field up to 15 MWe and to investigate the vertical distribution of clay alteration from the surface area down to a depth of 1000 m where temperatures exceed 250 °C. Special attention has been paid to the “clay signature” of the fractured zones which channel the present geothermal fluids.
Three successive zones, dominated, respectively by dioctahedral smectite, illite and chlorite were identified at increasing depths. Alteration petrography indicates that these mineralogical clay zones result from the spatial superimposition of at least two successive alteration stages.
The first one, assimilated to a propylitic alteration stage, affected all parts of the system and consisted of crystallization of trioctahedral phyllosilicates (chlorite or corrensite), Ca-silicates (heulandite-clinoptilolite, prehnite, pumpelleyite, wairakite and epidote), quartz and minor calcite in replacement of most of the primary minerals of the intersected volcanic or volcanoclastic formations. The later stage of alteration is related to the circulation of the present geothermal fluids and is assimilated to argillic or phyllic alteration. It consists of a more or less intense argillization which results from the crystallization of aluminous dioctahedral clay phases (smectite, illite
±
I–S mixed layers, and accessory kaolinite) associated with quartz, calcite, hematite or pyrite. The permeable zones which channel most of the present geothermal fluids are fracture controlled and do not contain specific clay parageneses. However the illite
±
I–S mixed layers minerals differ from those of the surroundings by specific properties including both crystal structure and texture. These specific properties (decrease in the expandable component of the illitic material, increase of the illite crystallinity) can be controlled by the nucleation/growth rates operating in zones of active flow regime. Being mainly a product of the earlier propylitic alteration stage, chlorites are much less informative on the fracture controlled permeable levels. However, the compositional variations of chlorites recorded within the shallower fractured zone suggest a significant change in fO
2 conditions related to early circulation of fluids along the major near west striking normal faults (Plateau fault).
The steadily increasing luminosity of the LHC requires an upgrade with high-rate and high-resolution detector technology for the inner end cap of the ATLAS muon spectrometer: the New Small Wheels ...(NSW). In order to achieve the goal of precision tracking at a hit rate of about 15 kHz/cm2 at the inner radius of the NSW, large area Micromegas quadruplets with 100µm spatial resolution per plane have been produced. IRFU, from the CEA research center of Saclay, is responsible for the production and validation of LM1 Micromegas modules. The construction, production, qualification and validation of the largest Micromegas detectors ever built are reported here. Performance results under cosmic muon characterization will also be discussed.
The evaluation of the efficacy and toxicity of hyperthermic intraoperative peritoneal chemotherapy presents some difficulties, due in part to the lack of information about the pharmacokinetic ...behavior of the drugs administered in this procedure. The aim of this study was to characterize the population pharmacokinetics of hyperthermic intraoperative peritoneal oxaliplatin in Wistar rats and to evaluate the effect of treatment-related covariates dose, instillation time and temperature on the pharmacokinetic parameters.
Oxaliplatin peritoneal and plasma concentrations from 37 rats treated by either intravenous or intraperitoneal oxaliplatin administrations under different instillation times, temperatures and doses were analyzed according to a population pharmacokinetic approach using the software NONMEM V7.3®.
Intraperitoneal (n = 115) and plasma (n = 263) concentrations were successfully described according to a two-compartment model with first order absorption. No significant effect of dose, temperature and instillation time on pharmacokinetic parameters was found. However, an abrupt decrease in the elimination process was observed, reflected in the structural pharmacokinetic model through a modification in clearance. The typical parameters values and the interindividual variability (CV %) in clearance, central and peripheral volume of distribution were 3.25 mL/min (39.1%), 53.6 mL (37.8%) and 54.1 mL (77.3%), respectively. Clearance decreased to 0.151 mL/min (39.1%) when the instillation was still ongoing, at 31.4 min. One of the possible reasons behind the clearance decrease would be an alteration of renal function due to surgery and/or hyperthermia.
This study described the deterioration of the drug elimination process due to the procedure, and estimated the time at which this deterioration is most likely to occur. In addition, dose, instillation time and temperature had no influence in the PK parameters.
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Abstract
A muon metrology experiment is presented: two distant muon detection systems are used in coincidence to detect these particles originating from primary cosmic rays. The excellent spatial ...resolution of the Micromegas detectors allows for a precise relative positioning of the two instruments. The current setup can be used to monitor mid- or long-term deformations of a structure down to sub-millimeter resolution. It could also be employed to roughly position a distant structure with single muon detection, a typical example being an underground cavity whose position with respect to the surface is poorly known.
The toc1 mutation causes shortened circadian rhythms in light-grown Arabidopsis plants. Here, we report the same toc1 effect in the absence of light input to the clock. We also show that TOC1 ...controls photoperiodic flowering response through clock function. The TOC1 gene was isolated and found to encode a nuclear protein containing an atypical response regulator receiver domain and two motifs that suggest a role in transcriptional regulation: a basic motif conserved within the CONSTANS family of transcription factors and an acidic domain. TOC1 is itself circadianly regulated and participates in a feedback loop to control its own expression.
The study of interaction between microwave radiation and minerals is gaining increasing interest in the field of minerals and material processing. Further studies are, however, still required to ...deepen the understanding of such microwave heating mechanisms in order to develop innovative techniques for mineral treatment using microwave heating. In this paper, effects of sample shapes and thickness on the distribution of temperature inside the mineral ilmenite (FeTiO3) due to microwave heating were numerically studied using the finite element (FE) method. The analysis was carried out in such a way that the flux of microwave energy was converted into an equivalent amount of heat generation in the mineral through the Poynting theorem of conservation of energy for the electromagnetic field. In this study, as a first attempt, the cylinder and slab of ilmenite were modeled to be irradiated from top and bottom surfaces with the variation of cylinder and slab thicknesses. Temperature-dependent material properties of ilmenite were taken into account in the FE simulation. Corresponding boundary conditions were then applied accordingly to the cylinder and slab of ilmenite with comparable characteristic length. Numerical results showed that, in terms of temperature differences between locations having maximum and minimum temperatures, slab geometries tended to produce higher values in comparison to those of cylinder geometries with the thickness variation, while the profiles of temperature inside the ilmenite samples were similar for both geometries. For the same duration of microwave heating, the slab geometry, hence, induced greater non-uniformity of temperature inside the ilmenite. It was also observed that, for the ilmenite samples with thickness value greater than 1.5 cm, the hotspot locations were not in the center of the sample, but on the surface of sample. Moreover, from several thickness values considered in this study, the ilmenite sample with thickness value of 3 cm gave a good trade-off between the maximum temperature value attained and temperature differences inside the sample, for both geometries. Thus, the shape and thickness of ilmenite samples affect the effectiveness of microwave heating of ilmenite, in terms of maximum temperature attained, temperature differences, and uniformity of temperature.
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