61 research outputs found

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

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    This paper presents the results of determination of artificial 137Cs^{137}Cs and natural 40K^{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 137Cs^{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 137Cs^{137}Cs and 40K^{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

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    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

    A Neuron-Glial Perspective for Computational Neuroscience

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    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

    Key Learning Outcomes for Clinical Pharmacology and Therapeutics Education in Europe: A Modified Delphi Study.

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    Harmonizing clinical pharmacology and therapeutics (CPT) education in Europe is necessary to ensure that the prescribing competency of future doctors is of a uniform high standard. As there are currently no uniform requirements, our aim was to achieve consensus on key learning outcomes for undergraduate CPT education in Europe. We used a modified Delphi method consisting of three questionnaire rounds and a panel meeting. A total of 129 experts from 27 European countries were asked to rate 307 learning outcomes. In all, 92 experts (71%) completed all three questionnaire rounds, and 33 experts (26%) attended the meeting. 232 learning outcomes from the original list, 15 newly suggested and 5 rephrased outcomes were included. These 252 learning outcomes should be included in undergraduate CPT curricula to ensure that European graduates are able to prescribe safely and effectively. We provide a blueprint of a European core curriculum describing when and how the learning outcomes might be acquired

    Changes of spruce stands in the lower mountain forest belt subjected to active protection in the Tatra National Park

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    One of the most important objective of the active nature protection in national parks situated in Polish mountains is the restoration of mixed stands replaced by Norway spruce monocultures. Seven spruce stands situated in the Tatra National Park were measured in 1983−1986 and in 2001. The density of all stands decreased whereas the basal area and volume increased. In some of them the changes were considerable. The contribution of Fagus sylvatica and Abies alba, two most important tree species in natural mountain forests, changed only slightly and even decreased in three stands. Intensity of elimination of trees was related to their thickness – thin trees were removed from stands more often. Due to this way of thinning the variation of tree thickness diminished in all spruce stands. The densities of Fagus sylvatica and Acer pseudoplatanus saplings increased in all stands as a result of former planting. However, they are still to low for effective restoration of mixed stands. It can be concluded that mainly sanitary cuttings have been used recently in all stands. This line of management is not deliberately focused on the restoration of mixed stands and the diversification of their structure. It results in aging of dense spruce stands and increases the risk of future large−area disturbances due to strong winds and insect outbreaks

    Transect survey of artificial 137Cs and natural 40K in moss and bilberry leaf samples from two main valleys from Tatra National Park

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    This paper presents the results of determination of artificial 137Cs and natural 40K activity concentrations in plants (bilberry (Vaccinium myrtillus) and moss ( Polytrichum commune ) Polytrichum commune )) and in soil samples from two main Tatra Valleys; Kościeliska and Rybi Potok Valley. The data were obtained during two years (2001- 02). These plants are known a as good bio-monitors for radioceasium [1,2 ]. It is known that 137Cs and 40K isotopes play important roles in the environment, due to their good assimilation by plants. The transfer of these elements from soil to plant depends of many factors: type of soil, organic matter contents, pH, type of plants. In this paper some results concerning the transfer of 137 Cs and 40K isotopes from various types of Tatra soil to moss or bilberry are shown
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