558 research outputs found

    DIGITAL SOGATA

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    THE SOLAR AIRSTREAM FAB LAB DIGITAL SOGATA EXPOSITION + DEMONSTRATION ‘Sogata’ is an ancient Japanese clay molding technique that traditionally uses ‘sweeps’ to create ceremonial vessels in cast metal. It is a sustainable molding process that reuses materials. Data Sculptor Pioneer Paul Higham has developed a series of ‘data sweeps’ shaped by emergent forms from Brain Waves and Tsunami data. Sculptor Coral Lambert utilizes the ‘data sweeps’ to create ‘sogata’ clay molds which are then used to produce unique forms in cast iron. The Fab Lab is located in a 1960’s Airstream which has been converted to harness solar energy

    Reversible Band Gap Engineering in Carbon Nanotubes by Radial Deformation

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    We present a systematic analysis of the effect of radial deformation on the atomic and electronic structure of zigzag and armchair single wall carbon nanotubes using the first principle plane wave method. The nanotubes were deformed by applying a radial strain, which distorts the circular cross section to an elliptical one. The atomic structure of the nanotubes under this strain are fully optimized, and the electronic structure is calculated self-consistently to determine the response of individual bands to the radial deformation. The band gap of the insulating tube is closed and eventually an insulator-metal transition sets in by the radial strain which is in the elastic range. Using this property a multiple quantum well structure with tunable and reversible electronic structure is formed on an individual nanotube and its band-lineup is determined from first-principles. The elastic energy due to the radial deformation and elastic constants are calculated and compared with classical theories.Comment: To be appear in Phys. Rev. B, Apr 15, 200

    Thermoelectric effects in superconducting proximity structures

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    Attaching a superconductor in good contact with a normal metal makes rise to a proximity effect where the superconducting correlations leak into the normal metal. An additional contact close to the first one makes it possible to carry a supercurrent through the metal. Forcing this supercurrent flow along with an additional quasiparticle current from one or many normal-metal reservoirs makes rise to many interesting effects. The supercurrent can be used to tune the local energy distribution function of the electrons. This mechanism also leads to finite thermoelectric effects even in the presence of electron-hole symmetry. Here we review these effects and discuss to which extent the existing observations of thermoelectric effects in metallic samples can be explained through the use of the dirty-limit quasiclassical theory.Comment: 14 pages, 10 figures. 374th WE-Heraus seminar: Spin physics of superconducting heterostructures, Bad Honnef, 200

    Diurnal changes in pathogenic and indicator virus concentrations in wastewater

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    Wastewater-based epidemiology (WBE) has been commonly used for monitoring SARS-CoV-2 outbreaks. As sampling times and methods (i.e. grab vs composite) may vary, diurnal changes of viral concentrations in sewage should be better understood. In this study, we collected untreated wastewater samples hourly for 4 days at two wastewater treatment plants in Wales to establish diurnal patterns in virus concentrations and the physico-chemical properties of the water. Simultaneously, we also trialled three absorbent materials as passive samples as a simple and cost-efficient alternative for the collection of composite samples. Ninety-six percent of all liquid samples (n = 74) and 88% of the passive samplers (n = 59) were positive for SARS-CoV-2, whereas 87% and 97% of the liquid and passive samples were positive for the faecal indicator virus crAssphage, respectively. We found no significant daily variations in the concentration of the target viruses, ammonium and orthophosphate, and the pH and electrical conductivity levels were also stable. Weak positive correlations were found between some physico-chemical properties and viral concentrations. More variation was observed in samples taken from the influent stream as opposed to those taken from the influent tank. Of the absorbent materials trialled as passive samples, we found that tampons provided higher viral recoveries than electronegative filter paper and cotton gauze swabs. For all materials tested, viral recovery was dependent on the virus type. Our results indicate that grab samples may provide representative alternatives to 24-h composite samples if taken from the influent tank, hence reducing the costs of sampling for WBE programmes. Tampons are also viable alternatives for cost-efficient sampling; however, viral recovery should be optimised prior to use

    New horizons in geriatric medicine education and training: the need for pan-European education and training standards

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    The ageing population ought to be celebrated as evidence for the efficacy of modern medicine, but the challenge that this demographic shift presents for 21st century healthcare systems, with increasing numbers of people living with multi-morbidity and frailty, cannot be ignored. There is therefore a need to ensure that all healthcare professionals grasp the basic principles of care of older people. In this paper, we make a case for the development of pan-European education and training standards for the field of geriatric medicine. Firstly, the challenges which face the implementation and delivery of geriatric medicine in a systematic way across Europe are described – these include, but are not limited to; variance in geriatric medicine practice across Europe, insecurity of the specialty in some countries and significant heterogeneity in geriatric medicine training programs across Europe. The opportunities for geriatric medicine are then presented and we consider how engendering core geriatric medicine competencies amongst nongeriatricians has potential to bridge existing gaps in service provision across Europe. Finally, we consider how work can proceed to teach sufficient numbers of doctors and health professionals in the core knowledge, skills and attitudes required to do this. To safeguard the future of the specialty across Europe, we contend that there is a need to strive towards harmonisation of post-graduate geriatric medicine training across Europe, through the establishment of pan-European education and training standards in the specialty

    Zero-Branes, Quantum Mechanics and the Cosmological Constant

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    We analyse some dynamical issues in a modified type IIA supergravity, recently proposed as an extension of M-theory that admits de Sitter space. In particular we find that this theory has multiple zero-brane solutions. This suggests a microscopic quantum mechanical matrix description which yields a massive deformation of the usual M(atrix) formulation of M-theory and type IIA string theory.Comment: 15 pages LaTeX, added reference

    A Rapid New Assay to Detect RNA Editing Reveals Antipsychotic-Induced Changes in Serotonin-2C Transcripts

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    ABSTRACT We report the development of a new assay as an alternative to direct DNA sequencing to measure RNA-edited variation in tissue. The new assay has been validated and is accurate, cheaper, more rapid, and less labor-intensive than DNA sequencing. We also outline the statistical modeling required for analyses of the hierarchical, clustered RNA-editing data generated in these studies. Using the new technique, we analyzed the effects of long-term antipsychotic medication on serotonin-2C receptor (5-HT 2C R) RNA editing in rat brain. Our hypothesis that a drug with high affinity for 5-HT 2C R, such as clozapine, would alter its RNA-editing profile was not confirmed. Whereas haloperidol, a typical antipsychotic drug that is primarily a dopamine receptor antagonist, reduced 5-HT 2C VNV isoform frequency and the level of RNA editing at the D site, risperidone and not the prototype atypical antipsychotic drug clozapine increased the frequency of 5-HT 2C VNV and D-site editing. Our data emphasize that caution is required in the interpretation of RNA-editing data in studies of psychiatric disorders, because these studies usually include subjects who received long-term exposure to medication. This newly established method will facilitate high-throughput investigations of RNA editing in disease pathology and in the pharmacological activity of drugs. The revelation that the human genome comprises between 30,000 and 40,000 protein-coding genes was unexpected, because such few genes are unlikely to explain the functional diversity between humans and less complex organisms. These interspecies differences could arise from post-transcriptional processes such as RNA editing and alternative splicing, which allow a single gene to generate several protein variants. The current study focuses on RNA editing. The recent detection of 1637 potential new substrates for RNA editing Because of their relatively recent discovery, substrates of RNA editing have not been extensively characterized. Adenine-to-inosine RNA editing in mammalian brain has been identified in ionotropic receptors (such as the GluR2 subunit of the ␣-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor) and in the serotonin (5-HT)-2C receptor (R), which is coupled to GTP-binding protein. Discrepancies between genomic DNA and cDNA sequences led to the discovery of nucleotide changes caused by the activity of ADAR enzymes. In the fully edited 5-HT 2C R, three amino acid codons in the pre-mRNA are changed so that the sequence coding for IRNPI becomes VRGP
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