14,033 research outputs found

    BrainBasher: a BCI Game

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    Brain-computer interaction (BCI) is starting to focus on healthy subjects. This research adresses the effects of using this novel input modality to control a simple game, and also looks into the beneficial effects of bringing game elements into BCI experiments. A simple BCI game has been developed and evaluated with fifteen subjects using the Game Experience Questionnaire (GEQ) developed at the Eindhoven Game Experience Lab. Three variations of the game were evaluated for comparison: the original game with BCI input, one with keyboard input, and one with a more clinical look leaving out all extraneous information. The keyboard-controlled game was considered easy and boring, whereas using BCI for input resulted in a more challenging, immersive and richer experience. The design and additional information presented by the game also resulted in higher immersion compared to the clinical design

    Thermoelectric performance of multiphase XNiSn (X = Ti, Zr, Hf) half-Heusler alloys

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    Quantitative X-ray powder diffraction analysis demonstrates that mixing Ti, Zr and Hf on the ionic site in the half-Heusler structure, which is a common strategy to lower the lattice thermal conductivity in this important class of thermoelectric materials, leads to multiphase behaviour. For example, nominal Ti0.5Zr0.5NiSn has a distribution of Ti1−xZrxNiSn compositions between 0.24 ≤ x ≤ 0.70. Similar variations are observed for Zr0.50Hf0.5NiSn and Ti0.5Hf0.5NiSn. Electron microscopy and elemental mapping demonstrate that the main compositional variations occur over micrometre length scales. The thermoelectric power factors of the mixed phase samples are improved compared to the single phase end-members (e.g. S2/ρ = 1.8 mW m−1 K−2 for Ti0.5Zr0.5NiSn, compared to S2/ρ = 1.5 mW m−1 K−2 for TiNiSn), demonstrating that the multiphase behaviour is not detrimental to electronic transport. Thermal conductivity measurements for Ti0.5Zr0.5NiSn0.95 suggest that the dominant reduction comes from Ti/Zr mass and size difference phonon scattering with the multiphase behaviour a secondary effect

    Wess-Zumino-Witten model off criticality

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    We study the renormalization group flow properties of the Wess-Zumino-Witten model in the region of couplings between g2=0g^2=0 and g2=4π/kg^2=4\pi/k, by evaluating the two-loop Zamolodchikov's cc-function. We also discuss the region of negative couplings.Comment: 8 page

    Atherosclerotic Calcification: Determinants and Clinical Neurological Consequences

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    __Abstract__ Atherosclerosis is a highly frequent vascular disease that exerts huge influence on the health care system. Major clinical conditions caused by atherosclerosis are ischemic heart disease (myocardial infarction) and stroke, both top causes of global morbidity and mortality in middle-aged and elderly persons. Due to the aging of the population, the global burden of atherosclerosis, and thereby of its clinical consequences, will continue to rise in the coming decades. The purpose of my thesis is to expand the knowledge on determinants - or risk factors - and neurological consequences of atherosclerosis, with a specific focus on differences across vessel beds. The research described in my thesis was performed within the framework of the Rotterdam Study;21 a large prospective, population-based cohort study aimed at investigating determinants of various chronic diseases in the elderly. Using CT-imaging in this population-based setting, I studied atherosclerosis in four major vessel beds: the coronary arteries, aortic arch and the extracranial and intracranial part of the internal carotid arteries

    Actual and Imagined Movement in BCI Gaming

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    Most research on Brain-Computer Interfaces (BCI) focuses\ud on developing ways of expression for disabled people who are\ud not able to communicate through other means. Recently it has been\ud shown that BCI can also be used in games to give users a richer experience\ud and new ways to interact with a computer or game console.\ud This paper describes research conducted to find out what the differences\ud are between using actual and imagined movement as modalities\ud in a BCI game. Results show that there are significant differences\ud in user experience and that actual movement is a more robust way of\ud communicating through a BCI

    Evaluatie Opvangbeleid 2005-2008 overwinterende ganzen en smienten. Deelrapport 11. Effect van Brandganzen op broedende weidevogels

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    Deze studie onderzoekt op welke wijze de tijdsbesteding van broedende weidevogels en de vegetatie van de broedhabitat wordt beïnvloed door de aanwezigheid overwinterende en in Nederland broedende Brandganzen. De nabijheid van Brandganzen werd door weidevogels als bedreigend voor hun eieren ervaren. Begrazing door Brandganzen had een negatief effect op hoogte en drooggewicht van de vegetatie vlak voor en tijdens de broedperiode van weidevogels waardoor mogelijk de nestplaatskeuze van weidevogels kan worden beïnvloed. Het effect van Brandganzen op de vestiging van weidevogels is in deze studie onderbelicht gebleven en ook is niet gekeken naar het effect op kuikenoverleving. De resultaten moeten daarom met enige voorzichtigheid geïnterpreteerd worden. Aldus resultaten van Alterra in samenwerking met Altenburg & Wymeng

    Een pilotstudie naar de interacties tussen broedende weidevogels en Brandganzen

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    De voor Nederland zo typerende natte graslanden van het laagveen- en zeekleigebied worden momenteel bevolkt door twee karakteristieke groepen vogels. Hun habitatvoorkeur komt sterk overeen, maar voor het overige verschillen ze duidelijk van elkaar. De in hun broedseizoen van dierlijk voedsel afhankelijke weidevogels gaan sterk in populatieomvang achterui

    Demographic and epidemiological characteristics of major regions, 1990-2001

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    In an era when most societies are coping with greater demand for health resources, choices will have to be made about the provision of health services. Strategic health planning must take into account the comparative burden of diseases and injuries, and the risk factors that cause them, and how this burden is likely to change under various policies and interventions. The Global Burden of Disease (GBD) framework is the principal, if not the only, framework for integrating and analyzing information on population health and making it more relevant for health policy and planning purposes. The comprehensive findings of the 2001 GBD study represent a major update of the effort launched with the 1990 GBD study. The 1990 GBD study was a major advance in the quantification of the impact of diseases, injuries, and risk factors on population health globally and by region. Government and nongovernmental agencies alike have used its results to argue for more strategic allocation of health resources to programs that are likely to yield the greatest gains in population health. Publication of the 1990 results led to improvements in analytical methods and mortality data in a number of countries. In addition, critiques of methodological approaches used in the 1990 study prompted a new framework for risk factor assessment along with systematic attempts to quantify some of the uncertainty in national and global assessments of disease burden. The 2001 GBD provides a new and improved baseline for measuring progress in global health

    The role of ras gene in the development of haemic neoplasia in Mytilus trossulus

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    Disseminated neoplasia has been reported in mussels (Mytilus spp) from numerous locations worldwide. This condition is progressive and fatal and the aetiology is unknown. In vertebrates, oncogenes such as ras, and tumour suppressor genes such as p53, play important roles in carcinogenesis. We have cloned a Mytilus trossulus homologue of the vertebrate ras gene, which shows conserved sequence in regions of functional importance. Neoplastic hemolymph samples derived from M. trossulus have been investigated for the presence of ras gene mutations and changes in expression

    Theoretical investigation of magnetic order in ReOFeAs, Re = Ce, Pr

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    Density functional theory (DFT) calculations are carried out on ReOFeAs, Re = Ce, Pr, the parent compounds of the high-Tc_c superconductors ReO1x_{1-x}Fx_{x}FeAs, in order to determine the magnetic order of the ground state. It is found that the magnetic moments on the Fe sites adopt a collinear antiferromagnetic order, similar to the case of LaOFeAs. Within the generalized gradient approximation along with Coulomb onsite repulsion (GGA+U), we show that the Re magnetic moments also adopt an antiferromagnetic order for which, within the ReO layer, same spin Re sites lie along a zigzag line perpendicular to the Fe spin stripes. While within GGA the Re 4f band crosses the Fermi level, upon inclusion of onsite Coulomb interaction the 4f band splits and moves away from the Fermi level, making ReOFeAs a Mott insulator.Comment: 5 pages, 4 figure
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