1,254 research outputs found

    Scalable interconnections for remote indirect exciton systems based on acoustic transport

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    Excitons, quasiparticles consisting of electron-hole pairs bound by the Coulomb interaction, are a potential medium for the processing of photonic information in the solid state. Information processing via excitons requires efficient techniques for the transport and manipulation of these uncharged particles.We have carried out a detailed investigation of the transport of excitons in GaAs quantum wells by surface acousticwaves. Based on these results, we introduce here a concept for the interconnection of multiple remote exciton systems based on the long-range transport of dipolar excitons by a network of configurable interconnects driven by acoustic wave beams. By combining this network with electrostatic gates, we demonstrate an integrated exciton multiplexer capable of interconnecting, gating, and routing exciton systems separated by millimeter distances. The multiplexer provides a scalable platform for the manipulation of exciton fluids with potential applications in information processingFinancial support by DFG Project No. SA 598/

    Search for Neutron Flux Generation in a Plasma Discharge Electrolytic Cell

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    Following some recent unexpected hints of neutron production in setups like high-voltage atmospheric discharges and plasma discharges in electrolytic cells, we present a measurement of the neutron flux in a configuration similar to the latter. We use two different types of neutron detectors, poly-allyl-diglicol-carbonate (PADC, aka CR-39) tracers and Indium disks. At 95% C.L. we provide an upper limit of 1.5 neutrons cm^-2 s^-1 for the thermal neutron flux at ~5 cm from the center of the cell. Allowing for a higher energy neutron component the largest allowed flux is 64 neutrons cm^-2 s^-1. This upper limit is two orders of magnitude smaller than what previously claimed in an electrolytic cell plasma discharge experiment. Furthermore the behavior of the CR-39 is discussed to point our possible sources of spurious signals.Comment: 4 pages, 3 figure

    Improving safety through non-technical skills in chemical plants: The validity of a questionnaire for the self-assessment of workers

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    This research is aimed at developing a questionnaire for the self-assessment of non-technical skills (NTS) leading to safety in the chemical sector and at analysing the properties of its scales in terms of construct validity. The research involved 269 Italian employees from three chemical plants of an international company, who occupied low\u2013medium levels in the organizational hierarchy. Results showed a good level of validity and reliability of the instrument and suggested that communication, situational awareness, decision-making, and fatigue/stress management are the four most important NTS for safety in the chemical sector

    Stimulating Multiple-Demand Cortex Enhances Vocabulary Learning

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    It is well established that networks within multiple-demand cortex (MDC) become active when diverse skills and behaviors are being learnt. However, their causal role in learning remains to be established. In the present study, we first performed functional magnetic resonance imaging on healthy female and male human participants to confirm that MDC was most active in the initial stages of learning a novel vocabulary, consisting of pronounceable nonwords (pseudowords), each associated with a picture of a real object. We then examined, in healthy female and male human participants, whether repetitive transcranial magnetic stimulation of a frontal midline node of the cingulo-opercular MDC affected learning rates specifically during the initial stages of learning. We report that stimulation of this node, but not a control brain region, substantially improved both accuracy and response times during the earliest stage of learning pseudoword– object associations. This stimulation had no effect on the processing of established vocabulary, tested by the accuracy and response times when participants decided whether a real word was accurately paired with a picture of an object. These results provide evidence that noninvasive stimulation to MDC nodes can enhance learning rates, thereby demonstrating their causal role in the learning process. We propose that this causal role makes MDC candidate target for exper- imental therapeutics; for example, in stroke patients with aphasia attempting to reacquire a vocabulary

    Fusarium spp en trigo, capacidad toxicogenica y quimiotaxonomia de las cepas aisladas en la Argentina

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    Se aislaron e identificaron 91 cepas de Fusarium spp (F graminearum, F equiseti, F moniliforme, F m var anthophilum, F acuminatum, F solani y F oxisporum) a partir de semillas de trigo pan procedentes de 17 localidades trigueras de la República Argentina. Mediante el cultivo de las mismas en arroz pelado y pulido se evaluó la producción de tricotecenos y zearalenona, a los efectos de revelar si existen diferencias regionales en cuanto a su presencia. Se detectaron cepas productoras de tricotecenos del grupo B y zearalenona, no habiéndose hallado productoras del grupo A. De las cepas evaluadas el 82,4% produjeron tricotecenos que se subdividieron en dos grupos: a) las cepas productoras de deoxinivalenol (DON) y su precursor 3 acetil-deoxinivalenol (AcDON) y b) las productoras de nivalenol (NIV) y su precursor 4 acetil-nivalenol o fusarenona-x (FUS-X). Los resultados demostraron que el 48,3% de las cepas fueron productoras de DON, el 7,7% de NIV y el 26,4% tuvieron la capacidad de producir simultaneamente DON y NIV en los cultivos. Al considerar exclusivamente las cepas de F graminearum el 89,4% fueron toxicogénicas, de ellas el 55,9% pertenecieron al quimiotipo DON, 10,3% al quimiotipo NIV y 33,8% produjeron DON y NIV. En cuanto a la zearalenona (ZEA) el 63,2% del total de las cepas fueron productoras de esta toxina, no existiendo ninguna relación entre los grupos DON y NIV con la producción de ZEA. La distribución de las cepas toxicogénicas de Fusarium spp observada en las distintas localidades de la República Argentina, permite inferir la existencia de diferencias regionales en el área triguera.In wheat seeds from 17 different wheat growing sites, 91 Fusarium spp strains (F graminearum, F equiseti, F moniliforme, F m var anthophilum, F acuminatum, F solani and F oxysporum) were isolated and identified. The production of trichothecenes and zearalenone was evaluated after growing them on peeled and polished rice to find out if there were any regional differences in their prevalence. Strains producing trichothecenes of the B group and zearalenone were detected; no producers of the A groups were found. From the strains studied, 82.4% produced trichothecenes, and could be divided into 2 groups: a), deoxynivalenol (DON) producing strains and its precursor 3 acetyldeoxynivalenol (AcDON); and b), nivalenol (NIV) producing strains and its precursor 4 acetylnivalenol or fusarenone-x (FUS-X). The results showed that 48.3% of the strains were DON producers, 7.7% NIV producers and 26.4% produced both DON and NIV. Eighty-nine point four percent Fgraminearum strains were toxigenic; among them 55.9% were DON chemotype, 10.3% NIV chemotype and 33.8% produced DON and NIV. Sixty-three point two percent of the strains also produced zearalenone (ZEA), no relation existing between the DON and NIV groups with regard to ZEA production. The finding of certain toxigenic strains in various sites in Argentina allows us to conclude that regional differences exist

    "Is this case of a very rare disease work-related?" A review of reported cases of Pacinian neuroma.

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    Objective In response to a request for a medicolegal opinion from an orthopaedic technician with pacinian neuroma of the hand, we conducted a systematic review of reported cases designed to assess whether this rare disease could be considered to be work-related.Methods We used Medline, Embase, Google Scholar, Google, and a manual search to identify reports of histologically confirmed pacinian neuroma of the hand manifesting after 15 years of age. Cases with available information (from article/authors) on personal history were considered eligible. We tabulated information on age/gender; localization and histopathologic features; signs/symptoms; history of local trauma; occupation, sports/hobbies or other physical exposures; right- or left-handedness; and outcome.Results We found 44 eligible cases (including the present referral). Of these, 21 (48%) followed a trauma [<6 months from onset/presentation (N=7); 0.5\u20132 years from onset (N=6); 652 years from onset (N=7); and timing unknown (N=1)] involving the same anatomic site. Three of these 21 traumas definitely occurred at work, and a further 2 cases occurred at the site of definite work-related repetitive microtrauma.Conclusions The results reinforce the concept that pacinian neuroma of the hand can follow local trauma or repetitive microtrauma. Implicated traumas were either recent or remote, and they sometimes occurred while performing manual tasks at work. We concluded that the referred case could plausibly be considered work-related
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