Imposer une forme à l'informe

Donner forme aux angoisses implique une représentation matérielle d'émotions immatérielles. Par conséquent, il n'y a pas de forme de référence réelle. Par métaphore, on peut considérer que l'intériorité psychologique et physique se correspondent. Nous sommes d'une certaine manière sur le terrain de l'informe. Excrétion du corps, cette notion d'informe interdit-elle la suggestion d'une forme et en particulier celle du corps ? Comment mettre en œuvre par des opérations plastiques cette tension entre forme et informe ? Cette distinction ténue entre la forme et l'informe a inspiré un dispositif pédagogique où les élèves ont été mis à la recherche d'une forme insaisissable. A partir d'une empreinte fabriquée par nos soins, ils ont tenté de définir la forme d'une créature inexistante, irréelle qui n'a donc pas de forme déterminable. Ils peuvent transcrire des contours et des surfaces, compléter les manques par l'imagination et finalement inventer un être irréel, ne rentrant pas dans les catégories des espèces animales existantes. Cette séquence a été l'occasion d'expérimenter quelques pratiques conventionnelles du dessin tout en évacuant la question de la représentation du réel, source de difficultés pour les élèves.Dans un premier temps, nous aborderons le rôle de l'enveloppe dont la double fonction permet aussi bien de mettre en évidence que de dissimuler. Ensuite, la notion d'hétérogénéité sera développée en deux axes : l'informe et les influences hétérogènes. Puis, nous verrons comment la forme peut être malmenée par la mise en œuvre de ses ambiguïtés. Enfin, la question des actes instaurés dans ces excrétions d'angoisses comme moyen de circonscrire pour maîtriser sera étudiée

Combination of nitrate (N, O) and boron isotopic ratios with microbiological indicators for the determination of nitrate sources in karstic groundwater

International audienceA new approach based on measurements of nitrate and boron isotopic composition associated with microbiological indicators for the determination of nitrate origin in karstic groundwater (SW, France) is presented. Nitrate and boron isotopic data indicate an animal source of nitrate (delta N-15-NO3- > 5 parts per thousand, delta O-18-NO3- < 10 parts per thousand and delta B-11 similar to 25 parts per thousand). Microorganism detection (bacteriophages) confirmed contamination from animal sources and proved fast water transfer (2-3 days) from surface to groundwater

Geological and Morphometric Characteristics of Quaternary Pyroclastic Aquifers in Salak and Pangrango Stratovolcano.

Indonesia is located in a subduction zone formed by the collision of continental and oceanic plates. Many volcanoes form as a result of these conditions along the arc. Springs on the volcano's slopes are widely used for domestic, irrigation, and industry water use. Investigating the characteristics of aquifers and springs is essential to ensure groundwater sustainability by providing a robust geological framework. Meanwhile, groundwater in a volcanic geological setting has good quality characteristics because of its occurrence process, which interacts with many minerals in pyroclastic rocks that act as aquifers. The study area is located in the Lido Catchment Area (LCA), which is situated between two distinct volcanic slopes. Geological and morphometric analysis at LCA is the basis of important information relating to its hydrogeological systems. The analysis of thin rock sections and parameters of the physical properties of water in groundwater springs supports our research. We applied a comprehensive geological and morphometric analysis to obtain detailed information about the aquifer. This study aimed to determine the characteristics of aquifers in pyroclastic rocks and their relationship to the formation of springs. From the research conducted, the characteristic of water can be distinguished based on the geological conditions of its constituents. There are 6 different lithological characteristics in the study area: polymictic breccia, monomictic breccia, lapilli, lapilli tuff, coarse tuff, and fine tuff. From the lithology variations obtained, breccia, lapilli, and coarse tuff can play a good role as aquifers. Geological correlations and groundwater systems in the study area show groups of superficial, mixed, and alteration springs. The system of water flows in aquifers through inter-grains or rock fractures. The types of springs in LCA are dominated by depression and fracture types. These results are fundamental information for understanding hydrogeological systems in future volcanic geological settings

The Autophagic Flux Inhibitor Bafilomycine A1 Affects the Expression of Intermediary Metabolism-Related Genes in Trout Hepatocytes

Autophagy is an evolutionarily conserved process of cellular self-eating which emerged these last years as a major adaptive metabolic response to various stresses such as fasting, hypoxia, or environmental pollutants. However, surprisingly very few data is currently available on its role in fish species which are directly exposed to frequent environmental perturbations. Here, we report that the treatment of fasted trout hepatocytes with the autophagy inhibitor Bafilomycine A1 lowered the mRNA levels of many of the gluconeogenesis-related genes and increased those of genes involved in intracellular lipid stores. Concurrently, intracellular free amino acid levels dropped and the expression of the main genes involved in the endoplasmic reticulum (ER) stress exhibited a sharp increase in autophagy inhibited cells. Together these results highlight the strong complexity of the crosstalk between ER, autophagy and metabolism and support the importance of considering this function in future studies on metabolic adaptation of fish to environmental stresses

Modification and preservation of environmental signals in speleothems

Speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system. However, the climatological meaning of many speleothem records cannot be interpreted unequivocally; this is particularly so for more subtle shifts and shorter time periods, but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward. An explicit description of speleothem records as time series draws attention to the nature and importance of the signal filtering processes by which the weather, the seasons and longer-term climatic and other environmental fluctuations become encoded in speleothems. We distinguish five sources of variation that influence speleothem geochemistry: atmospheric, vegetation/soil, karstic aquifer, primary speleothem crystal growth and secondary alteration and give specific examples of their influence. The direct role of climate diminishes progressively through these five factors. \ud \ud We identify and review a number of processes identified in recent and current work that bear significantly on the conventional interpretation of speleothem records, for example: \ud \ud 1) speleothem geochemistry can vary seasonally and hence a research need is to establish the proportion of growth attributable to different seasons and whether this varies over time. \ud \ud 2) whereas there has traditionally been a focus on monthly mean Ã�´18O data of atmospheric moisture, current work emphasizes the importance of understanding the synoptic processes that lead to characteristic isotope signals, since changing relative abundance of different weather types might 1Corresponding author, fax +44(0)1214145528, E-mail: [email protected] control their variation on the longer-term. \ud \ud 3) the ecosystem and soil zone overlying the cave fundamentally imprint the carbon and trace element signals and can show characteristic variations with time. \ud \ud 4) new modelling on aquifer plumbing allows quantification of the effects of aquifer mixing. \ud \ud 5) recent work has emphasized the importance and seasonal variability of CO2-degassing leading to calcite precipitation upflow of a depositional site on carbon isotope and trace element composition of speleothems. \ud \ud 6) Although much is known about the chemical partitioning between water and stalagmites, variability in relation to crystal growth mechanisms and kinetics is a research frontier. \ud \ud 7) Aragonite is susceptible to conversion to calcite with major loss of chemical information, but the controls on the rate of this process are obscure. \ud \ud Analytical factors are critical to generate high-resolution speleothem records. A variety of methods of trace element analysis are available, but standardization is a common problem with the most rapid methods. New stable isotope data on Irish stalagmite CC3 compares rapid laser-ablation techniques with the conventional analysis of micromilled powders and ion microprobe methods. A high degree of comparability between techniques for Ã�´18O is found on the mm-cm scale, but a previously described high-amplitude oxygen isotope excursion around 8.3 ka is identified as an analytical artefact related to fractionation of the laser-analysis associated with sample cracking. High-frequency variability of not less than 0.5o/oo may be an inherent feature of speleothem Ã�´18O records

The Metabolic Consequences of Hepatic AMP-Kinase Phosphorylation in Rainbow Trout

AMP-activated protein kinase (AMPK), a phylogenetically conserved serine/threonine protein kinase, is proposed to function as a “fuel gauge” to monitor cellular energy status in response to nutritional environmental variations. However, in fish, few studies have addressed the metabolic consequences related to the activation of this kinase. This study demonstrates that the rainbow trout (Oncorhynchus mykiss) possesses paralogs of the three known AMPK subunits that co-diversified, that the AMPK protein is present in the liver and in isolated hepatocytes, and it does change in response to physiological (fasting-re-feeding cycle) and pharmacological (AICAR and metformin administration and incubations) manipulations. Moreover, the phosphorylation of AMPK results in the phosphorylation of acetyl-CoA carboxylase, a main downstream target of AMPK in mammals. Other findings include changes in hepatic glycogen levels and several molecular actors involved in hepatic glucose and lipid metabolism, including mRNA transcript levels for glucokinase, glucose-6-phosphatase and fatty acid synthase both in vivo and in vitro. The fact that most results presented in this study are consistent with the recognized role of AMPK as a master regulator of energy homeostasis in living organisms supports the idea that these functions are conserved in this piscine model

Molecular characterization of a gilthead sea bream (Sparus aurata) muscle tissue cDNA for carnitine palmitoyltransferase 1B (CPT1B)

Understanding the control of piscine fatty acid metabolism is important for determining the nutritional requirements of fish, and hence for the production of optimal aquaculture diets. The regulation and expression of carnitine palmitoyltransferase 1 (CPT1; EC No 2.3.1.21) are critical processes in the control fatty acid metabolism, and here we report a cDNA from gilthead sea bream (Sparus aurata) which encodes a protein with high identity to vertebrate CPT1. This sea bream CPT1 mRNA is predominantly expressed in skeletal and cardiac muscle, with little expression in other tissues. Phylogenetic analysis of other vertebrate CPT1 sequences show that fish genomes contain a single gene related to mammalian CPT1B, and a further two multi-gene families related to mammalian CPT1A. Genes related to mammalian CPT1C are absent in fish. Therefore, based on both functional and evolutionary orthology to mammalian CPT1B, the sea bream CPT1 reported here is a CPT1B isoform. Sea bream CPT1B mRNA expression progressively decreases in heart and muscle up to 12 hours after last feeding, but returns to initial, non-fasted levels after 72 hours. In contrast, in liver non-fasted expression is low, but strongly increases at 24 and 72 hours after last feeding. In white muscle and liver, CPT1B mRNA expression is highly correlated with the expression of peroxisomal proliferator-activated receptor ı (PPARı).Thus fatty acid metabolism by CPT1B and its control by PPARs is similar in fish and mammals, but multiple genes for CPT1A-like proteins in fish also suggest different and more complex pathways of lipid utilisation than in mammals