111 research outputs found

    All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters

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    We report on the ion beam fabrication of all-carbon multi electrode arrays (MEAs) based on 16 graphitic micro-channels embedded in single-crystal diamond (SCD) substrates. The fabricated SCD-MEAs are systematically employed for the in vitro simultaneous amperometric detection of the secretory activity from populations of chromaffin cells, demonstrating a new sensing approach with respect to standard techniques. The biochemical stability and biocompatibility of the SCD-based device combined with the parallel recording of multi-electrodes array allow: i) a significant time saving in data collection during drug screening and/or pharmacological tests over a large number of cells, ii) the possibility of comparing altered cell functionality among cell populations, and iii) the repeatition of acquisition runs over many cycles with a fully non-toxic and chemically robust bio-sensitive substrate.Comment: 24 pages, 5 figure

    Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families.

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    The CHRM2 gene is thought to be involved in neuronal excitability, synaptic plasticity and feedback regulation of acetylcholine release and has previously been implicated in higher cognitive processing. In a sample of 667 individuals from 304 families, we genotyped three singlenucleotide polymorphisms (SNPs) in the CHRM2 gene on 7q31–35. From all individuals, standardized intelligence measures were available. Using a test of within-family association, which controls for the possible effects of population stratification, a highly significant association was found between the CHRM2 gene and intelligence. The strongest association was between rs324650 and performance IQ (PIQ), where the T allele was associated with an increase of 4.6 PIQ points. In parallel with a large familybased association, we observed an attenuated – although still significant – population-based association, illustrating that population stratification may decrease our chances of detecting allele–trait associations. Such a mechanism has been predicted earlier, and this article is one of the first to empirically show that family-based association methods are not only needed to guard against false positives, but are also invaluable in guarding against false negatives

    The Play Behaviours of Roma Children in Transylvania

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    The Roma children of Transylvania are probably the most materially deprived in Europe. They often live in one-room shacks made from wood and mud, with no running water, no sanitation, and sometimes no heating. Many rely on charity for their food and medicines. But, are they play deprived? This paper summarises an observational study of the play behaviours of children in a small Roma village. It highlights the striking contrast between the abject poverty that characterises their lives and the general happiness of the children. These children live their limited lives to the full. They ‘play everywhere and with everything’, but not in the generally accepted sense of that phrase. The usual niceties of privacy, personal possessions and property boundaries are irrelevant here. Their play is rich in imagination and creativity; it is living proof of Nicholson’s theory of loose parts

    Permian high-temperature metamorphism in the Western Alps (NW Italy)

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    During the late Palaeozoic, lithospheric thinning in part of the Alpine realm caused high-temperature low-to-medium pressure metamorphism and partial melting in the lower crust. Permian metamorphism and magmatism has extensively been recorded and dated in the Central, Eastern, and Southern Alps. However, Permian metamorphic ages in the Western Alps so far are constrained by very few and sparsely distributed data. The present study fills this gap. We present U/Pb ages of metamorphic zircon from several Adria-derived continental units now situated in the Western Alps, defining a range between 286 and 266 Ma. Trace element thermometry yields temperatures of 580-890°C from Ti-in-zircon and 630-850°C from Zr-in-rutile for Permian metamorphic rims. These temperature estimates, together with preserved mineral assemblages (garnet-prismatic sillimanite-biotite-plagioclase-quartz-K-feldspar-rutile), define pervasive upper-amphibolite to granulite facies conditions for Permian metamorphism. U/Pb ages from this study are similar to Permian ages reported for the Ivrea Zone in the Southern Alps and Austroalpine units in the Central and Eastern Alps. Regional comparison across the former Adriatic and European margin reveals a complex pattern of ages reported from late Palaeozoic magmatic and metamorphic rocks (and relics thereof): two late Variscan age groups (~330 and ~300 Ma) are followed seamlessly by a broad range of Permian ages (300-250 Ma). The former are associated with late-orogenic collapse; in samples from this study these are weakly represented. Clearly, dominant is the Permian group, which is related to crustal thinning, hinting to a possible initiation of continental rifting along a passive margin

    Morphological docking of secretory vesicles

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    Calcium-dependent secretion of neurotransmitters and hormones is essential for brain function and neuroendocrine-signaling. Prior to exocytosis, neurotransmitter-containing vesicles dock to the target membrane. In electron micrographs of neurons and neuroendocrine cells, like chromaffin cells many synaptic vesicles (SVs) and large dense-core vesicles (LDCVs) are docked. For many years the molecular identity of the morphologically docked state was unknown. Recently, we resolved the minimal docking machinery in adrenal medullary chromaffin cells using embryonic mouse model systems together with electron-microscopic analyses and also found that docking is controlled by the sub-membrane filamentous (F-)actin. Currently it is unclear if the same docking machinery operates in synapses. Here, I will review our docking assay that led to the identification of the LDCV docking machinery in chromaffin cells and also discuss whether identical docking proteins are required for SV docking in synapses

    Genetic foundations of human intelligence

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    Map of deformation partitioning in the polydeformed and polymetamorphic Austroalpine basement in Valtellina and Val Camonica, (Central Alps)

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    Foliation trajectories, superposed to classical lithological information, have been used in this essay to represent the tectonometamorphic evolution of metamorphic rocks at the map scale. Each trajectory is characterized by a chronological connotation (dot pattern) and by a metamorphic connotation (colour); the relative timing of tectonic imprints has been reconstructed by means of the superposition of structures, while the metamorphic terms have been attributed on the basis of a meso- and microstructural-petrographic analysis of the metamorphic assemblages supporting all fabric elements (e.g. foliations, lineations). In addition, fabric gradients have been reported where pre-existing, quasi-isotropic rocks could be utilised (e.g. igneous rocks); these have been represented as colour gradients: from light colours (low strain domains = coronitic fabrics) to full colours (high strain domains = mylonitic fabrics). This new mapping approach, applied to a section of the Austroalpine domain of the Central Alps (Passo Mortirolo, Alta Val Camonica - Valtellina, Italy), which is characterized by polyphasic pre-Alpine and Alpine tectonometamorphic cycles, made the complete representation of lithostratigraphic and tectonometamorphic evolutions possible; therefore, this map is an example of a new method of representation of the full tectono-metamorphic history of a continental crust that underwent two superposed tectonic cycles (Variscan andAlpine) and successive structural stages related to a sequence of metamorphic re-equilibrations. Besides, this approach can be successfully applied in all tectonic and metamorphic settings generally recorded by metamorphic basements
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