INFLUENCE OF SOLUTION pH AND ELECTROLYTE PRESENCE ON BUBBLE VELOCITY IN ANIONIC SURFACTANT SOLUTIONS

Influence of sodium n-dodecyl sulfate (SDDS) concentration, presence of electrolytes (NaCl and KCl) and the solution pH variation on profiles of the bubble local velocity and values of the bubble terminal velocity were studied. It was found that in SDDS solutions the bubble accelerated rapidly after the detachment and either a maximum was observed (low SDDS solution concentrations) followed by a period of monotonic decrease or the terminal velocity was attained immediately after the acceleration stage (high SDDS concentrations). Addition of the electrolyte and/or the pH variation caused significant diminishing the local velocity in low concentrations solutions and lowering the bubble terminal velocity to a value characteristic for SDDS solutions of high concentrations. This effect of electrolyte and pH on the bubble velocity variations was attributed to lowering surface tension of the SDDS solutions. keywords: sodium n-dodecyl sulfate, SDDS, bubble; surface tension, adsorption coverage;velocity; fluidity of interface; adsorption kinetics; dynamic structure of adsorption layer

Concentrations of 137Cs^{137}Cs, 40K^{40}K radionuclides and some heavy metals in soil samples of Chochołowska Valley from Tatra National Park

This paper presents the results of determination of artificial $^{137}Cs$ and natural $^{40}K$ activity concentrations and some heavy metals in soil samples from the region of one of the main valleys of Tatra National Park (Chochołowska). Our investigation concentrated on $^{137}Cs$ and heavy metal levels in mountain soil taken from Chochołowska Valley, which revealed great variability in their concentration. The results show considerably small amounts of radionuclides $^{137}Cs$ and $^{40}K$ in the soils. Larger amounts of those elements can be found in the organic surface horizons of the soils. The evaluation of the content of those elements must be based on the bulk density analysis of the soil

Astroglial excitability and gliotransmission: an appraisal of Ca2+ as a signalling route

Astroglial cells, due to their passive electrical properties, were long considered subservient to neurons and to merely provide the framework and metabolic support of the brain. Although astrocytes do play such structural and housekeeping roles in the brain, these glial cells also contribute to the brain's computational power and behavioural output. These more active functions are endowed by the Ca2+-based excitability displayed by astrocytes. An increase in cytosolic Ca2+ levels in astrocytes can lead to the release of signalling molecules, a process termed gliotransmission, via the process of regulated exocytosis. Dynamic components of astrocytic exocytosis include the vesicular-plasma membrane secretory machinery, as well as the vesicular traffic, which is governed not only by general cytoskeletal elements but also by astrocyte-specific IFs (intermediate filaments). Gliotransmitters released into the ECS (extracellular space) can exert their actions on neighbouring neurons, to modulate synaptic transmission and plasticity, and to affect behaviour by modulating the sleep homoeostat. Besides these novel physiological roles, astrocytic Ca2+ dynamics, Ca2+-dependent gliotransmission and astrocyte–neuron signalling have been also implicated in brain disorders, such as epilepsy. The aim of this review is to highlight the newer findings concerning Ca2+ signalling in astrocytes and exocytotic gliotransmission. For this we report on Ca2+ sources and sinks that are necessary and sufficient for regulating the exocytotic release of gliotransmitters and discuss secretory machinery, secretory vesicles and vesicle mobility regulation. Finally, we consider the exocytotic gliotransmission in the modulation of synaptic transmission and plasticity, as well as the astrocytic contribution to sleep behaviour and epilepsy

EurOP2E – the European Open Platform for Prescribing Education, a consensus study among clinical pharmacology and therapeutics teachers

Purpose Sharing and developing digital educational resources and open educational resources has been proposed as a way to harmonize and improve clinical pharmacology and therapeutics (CPT) education in European medical schools. Previous research, however, has shown that there are barriers to the adoption and implementation of open educational resources. The aim of this study was to determine perceived opportunities and barriers to the use and creation of open educational resources among European CPT teachers and possible solutions for these barriers. Methods CPT teachers of British and EU medical schools completed an online survey. Opportunities and challenges were identified by thematic analyses and subsequently discussed in an international consensus meeting. Results Data from 99 CPT teachers from 95 medical schools were analysed. Thirty teachers (30.3%) shared or collaboratively produced digital educational resources. All teachers foresaw opportunities in the more active use of open educational resources, including improving the quality of their teaching. The challenges reported were language barriers, local differences, lack of time, technological issues, difficulties with quality management, and copyright restrictions. Practical solutions for these challenges were discussed and include a peer review system, clear indexing, and use of copyright licenses that permit adaptation of resources. Conclusion Key challenges to making greater use of CPT open educational resources are a limited applicability of such resources due to language and local differences and quality concerns. These challenges may be resolved by relatively simple measures, such as allowing adaptation and translation of resources and a peer review system

A Neuron-Glial Perspective for Computational Neuroscience

International audienceThere is growing excitement around glial cells, as compelling evidence point to new, previously unimaginable roles for these cells in information processing of the brain, with the potential to affect behavior and higher cognitive functions. Among their many possible functions, glial cells could be involved in practically every aspect of the brain physiology in health and disease. As a result, many investigators in the field welcome the notion of a Neuron-Glial paradigm of brain function, as opposed to Ramon y Cayal's more classical neuronal doctrine which identifies neurons as the prominent, if not the only, cells capable of a signaling role in the brain. The demonstration of a brain-wide Neuron-Glial paradigm however remains elusive and so does the notion of what neuron-glial interactions could be functionally relevant for the brain computational tasks. In this perspective, we present a selection of arguments inspired by available experimental and modeling studies with the aim to provide a biophysical and conceptual platform to computational neuroscience no longer as a mere prerogative of neuronal signaling but rather as the outcome of a complex interaction between neurons and glial cells

La fatigue et ses traitements

La fatigue est inhérente à tout organisme vivant. Accompagnant l homme depuis l origine, c est une plainte souvent vague et jusqu à une époque récente mal reconnue, devenue très fréquente en médecine au point d être baptisée : Maladie du siècle . La fatigue chronique ou asthénie (par opposition à la fatigue physiologique ou naturelle, consécutive à l effort et réversible avec le repos) est le symptôme majeur, quoique peu spécifique et difficile à mesurer, d un grand nombre de maladies tout en constituant parfois à elle seule une pathologie. La multiplicité de ces formes et de ces causes rend difficile une définition unique de l asthénie même si une origine commune peut en être trouvée au niveau cellulaire. L étude épidémiologique, au travers des statistiques et de la prévalence, confirme la difficulté d unification du concept. Elle rend d autant plus capital le diagnostic, qui à partir de la qualité de l écoute du patient (anamnèse), permettra de déterminer le traitement le plus approprié. Ces traitements, parfois préventifs ou curatifs, comme l hygiène de vie (alimentation, repos, ) ou les nombreuses thérapeutiques dont bien sûr la pharmacologie dans ses diverses déclinaisons n apportent pas à ce jour, malgré l avancée des recherches, une réponse totalement satisfaisante.LIMOGES-BU Médecine pharmacie (870852108) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Détection-localisation des défauts et reconfiguration dans un réseau de distribution d'énergie électrique

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF