Differential regulation of melatonin synthesis genes and phototransduction genes in embryonic chicken retina and cultured retinal precursor cells.

International audiencePhotoreceptor differentiation involves the activation of two specific sets of genes; those encoding the proteins of the phototransduction cascade and those encoding the enzymes of the melatonin synthesis pathway, arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole O-methyltransferase (HIOMT). The purpose of the present study was to examine the conditions of AANAT and HIOMT gene activation, relative to that of selected phototransduction markers (alpha-transducin and opsins), in both in vivo and in vitro differentiating photoreceptors of the chicken retina

On-chip thermal calibration with 8 CB liquid crystal of micro-thermal device

International audienceA micro sensor integrated on a micro-thermal device for bioexperiments requires affordable, rapid and accurate thermal 10 calibration. However, there has been no way to make thermal calibration directly under the microscope. This was the limitations in making numbers of bioexperiments with micro thermal devices. We present in this paper an inexpensive, fast and accurate way to realise such thermal calibration directly 15 under the microscope. We used a thermotropic liquid crystal: the 4-n-octyl-4-cyanobiphenyl（8CB） in order to reach the 313 K isothermal phase change on the device. Coupled with FEA simulations, we proved that this method enables us to make easy and accurate thermal calibration of micro-thermal device for 20 biological application

Acute and Delayed Neuromuscular Alterations Induced by Downhill Running in Trained Trail Runners: Beneficial Effects of High-Pressure Compression Garments

Introduction: The aim of this study was to examine, from a crossover experimental design, whether wearing high-pressure compression garments (CGs) during downhill treadmill running affects soft-tissue vibrations, acute and delayed responses in running economy (RE), neuromuscular function, countermovement jump, and perceived muscle soreness.Methods: Thirteen male trail runners habituated to regular eccentric training performed two separate 40-min downhill running (DHR, –8.5°) sessions while wearing either CGs (15–20 mmHg for quadriceps and calves) or control garments (CON) at a velocity associated with ∼55% of VO2max, with a set of measurements before (Pre-), after (Post-DHR), and 1 day after (Post-1D). No CGs was used within the recovery phase. Perceived muscle soreness, countermovement jump, and neuromuscular function (central and peripheral components) of knee extensors (KE) and plantar flexors (PF) were assessed. Cardiorespiratory responses (e.g., heart rate, ventilation) and RE, as well as soft-tissue vibrations (root mean square of the resultant acceleration, RMS Ar) for vastus lateralis and gastrocnemius medialis were evaluated during DHR and in Post-1D.Results: During DHR, mean values in RMS Ar significantly increased over time for the vastus lateralis only for the CON condition (+11.6%). RE and cardiorespiratory responses significantly increased (i.e., alteration) over time in both conditions. Post, small to very large central and peripheral alterations were found for KE and PF in both conditions. However, the deficit in voluntary activation (VA) was significantly lower for KE following CGs (–2.4%), compared to CON (–7.9%) conditions. No significant differences in perceived muscle soreness and countermovement jump were observed between conditions whatever the time period. Additionally, in Post-1D, the CGs condition showed reductions in neuromuscular peripheral alterations only for KE (from –4.4 to –7.7%) and perceived muscle soreness scores (–8.3%). No significant differences in cardiorespiratory and RE responses as well as countermovement jump were identified between conditions in Post-1D.Discussion: Wearing high-pressure CGs (notably on KE) during DHR was associated with beneficial effects on soft-tissue vibrations, acute and delayed neuromuscular function, and perceived muscle soreness. The use of CGs during DHR might contribute to the enhanced muscle recovery by exerting an exercise-induced “mechanical protective effect.

X-ray magnetic circular dichroïsm provides strong evidence for tetrahedral iron in ferrihydrite

International audience[1] Ferrihydrite is an important iron oxyhydroxide for earth and environmental sciences, biology, and technology. Nevertheless, its mineral structure remains a matter of debate. The stumbling block is whether a significant amount of tetrahedrally coordinated iron is present. Here we present the first X-ray magnetic circular dichroïsm (XMCD) measurements performed on a well characterized synthetic sample of 6-line fer-rihydrite, at both K and L 2,3 energy edges of iron. XMCD results demonstrate unambiguously the presence of tetrahedrally coordinated Fe(III) in the mineral structure, in quantities compatible with the latest extended X-ray absorption fine structure (EXAFS) analyses suggesting a concentration of 20–30%. Moreover , we find an antiferromagnetic coupling between tetrahedral and octahedral sublattices, with the octa-hedral sublattice parallel to the external magnetic field. Components: 5100 words, 3 figures

Down-Regulation of GABAA Receptor via Promiscuity with the Vasoactive Peptide Urotensin II Receptor. Potential Involvement in Astrocyte Plasticity

GABAA receptor (GABAAR) expression level is inversely correlated with the proliferation rate of astrocytes after stroke or during malignancy of astrocytoma, leading to the hypothesis that GABAAR expression/activation may work as a cell proliferation repressor. A number of vasoactive peptides exhibit the potential to modulate astrocyte proliferation, and the question whether these mechanisms may imply alteration in GABAAR-mediated functions and/or plasma membrane densities is open. The peptide urotensin II (UII) activates a G protein-coupled receptor named UT, and mediates potent vasoconstriction or vasodilation in mammalian vasculature. We have previously demonstrated that UII activates a PLC/PIPs/Ca2+ transduction pathway, via both Gq and Gi/o proteins and stimulates astrocyte proliferation in culture. It was also shown that UT/Gq/IP3 coupling is regulated by the GABAAR in rat cultured astrocytes. Here we report that UT and GABAAR are co-expressed in cerebellar glial cells from rat brain slices, in human native astrocytes and in glioma cell line, and that UII inhibited the GABAergic activity in rat cultured astrocytes. In CHO cell line co-expressing human UT and combinations of GABAAR subunits, UII markedly depressed the GABA current (β3γ2>α2β3γ2>α2β1γ2). This effect, characterized by a fast short-term inhibition followed by drastic and irreversible run-down, is not relayed by G proteins. The run-down partially involves Ca2+ and phosphorylation processes, requires dynamin, and results from GABAAR internalization. Thus, activation of the vasoactive G protein-coupled receptor UT triggers functional inhibition and endocytosis of GABAAR in CHO and human astrocytes, via its receptor C-terminus. This UII-induced disappearance of the repressor activity of GABAAR, may play a key role in the initiation of astrocyte proliferation

Beyond Autonomy: Coersion and Morality in Clinical Relationships

International audienc

Le rouge est mis: analyse des rouges dans la faïence de « grand feu » du xviiie et du xixesiècle (avec le rouge de Thiviers)

En faïence, le rouge de grand feu pose de nombreux problèmes dus à l’instabilité des oxydes de fer. Cette expérimentation porte sur l’analyse de divers échantillons de faïences archéologiques des xviiie et xixe siècles (Rouen, Nevers, Thiviers) par les méthodes MEB-EDS et la spectrométrie Raman. Avant les années 1760, les faïenciers ont obtenu des résultats variés et plus ou moins satisfaisants. Ensuite, ils sont parvenus à une maîtrise plus grande en employant directement une ocre ferrugineuse. Dès le début du xixe siècle, les faïenciers de Thiviers, dans le Périgord, ont su tirer parti d’un pigment issu des dalles silico-ferrugineuses locales, pour obtenir une couleur stable justement nommé rouge de Thiviers. Les analyses ont confirmé les textes qui assurent que ce pigment a également été utilisé à Nevers où on le trouve couramment dès les années 1835-1840. Malgré le petit nombre d’échantillons analysés, ces résultats montrent comment certaines manufactures régionales ont réussi à obtenir une couleur stable grâce au rouge de Thiviers dès le début du xixe siècle, rencontrant un large succès populaire qui leur a permis de survivre quelques décennies jusqu’ au développement des grandes usines produisant de nouveaux types de céramique qui allaient définitivement causer leur perte peu après le milieu du xixe siècle.The instability of the iron oxides make it very difficult to obtain the colour red in single- fired faïence. In this experiment, various samples of archaeological faïence from the 18th and 19th centuries were analysed (BSE images by SEM and Raman spectrometry). Before the 1760’s, the results obtained by faience manufacturers were various and more or less satisfactory. Later on, they eventually managed to reach a greater command by using directly an iron rich ochre. At the beginning of the 19th century, the manufacturers from Thiviers, in the Perigord region, managed to make the best use of a pigment extracted from the local quartz-ferriferous rock to obtain a stable colour precisely called Thiviers red. The analyses confirm the written sources which say that this pigment was also used in Nevers where it can commonly be found from 1835-1840 on. In spite of the small number of samples analysed, these results show how some local manufactures managed to obtain a stable colour thanks to Thiviers red at the beginning of the 19th century, meeting a large popular success which enabled them to survive for a few decades until the development of the large factories producing new types of ceramics which were eventually to cause their ruin shortly after the middle of the 19th century

Appeal No. 0678: Perto Drilling Corp., Inc. v. Division of Mineral Resources Management

Chief\u27s Order 99-15