11,778 research outputs found

    Cooperative Glutamatergic and Cholinergic Mechanisms Generate Short-Term Modifications of Synaptic Effectiveness in Prepositus Hypoglossi Neurons

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    To maintain horizontal eye position on a visual target after a saccade, extraocular motoneurons need a persistent (tonic) neural activity, called "eye-position signal," generated by prepositus hypoglossi (PH) neurons. We have shown previously in vitro and in vivo that this neural activity depends, among others mechanisms, on the interplay of glutamatergic transmission and cholinergic synaptically triggered depolarization. Here, we used rat sagittal brainstem slices, including PH nucleus and paramedian pontine reticular formation (PPRF). We made intracellular recordings of PH neurons and studied their synaptic activation from PPRF neurons. Train stimulation of the PPRF area evoked a cholinergic-sustained depolarization of PH neurons that outlasted the stimulus. EPSPs evoked in PH neurons by single pulses applied to the PPRF presented a short-term potentiation (STP) after train stimulation. APV (an NMDA-receptor blocker) or chelerythrine (a protein kinase-C inhibitor) had no effect on the sustained depolarization, but they did block the evoked STP, whereas pirenzepine (an M1 muscarinic antagonist) blocked both the sustained depolarization and the STP of PH neurons. Thus, electrical stimulation of the PPRF area activates both glutamatergic and cholinergic axons terminating in the PH nucleus, the latter producing a sustained depolarization probably involved in the genesis of the persistent neural activity required for eye fixation. M1-receptor activation seems to evoke a STP of PH neurons via NMDA receptors. Such STP could be needed for the stabilization of the neural network involved in the generation of position signals necessary for eye fixation after a saccade

    A Cholinergic Synaptically Triggered Event Participates in the Generation of Persistent Activity Necessary for Eye Fixation

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    An exciting topic regarding integrative properties of the nervous system is how transient motor commands or brief sensory stimuli are able to evoke persistent neuronal changes, mainly as a sustained, tonic action potential firing. A persisting firing seems to be necessary for postural maintenance after a previous movement. We have studied in vitro and in vivo the generation of the persistent neuronal activity responsible for eye fixation after spontaneous eye movements. Rat sagittal brainstem slices were used for the intracellular recording of prepositus hypoglossi (PH) neurons and their synaptic activation from nearby paramedian pontine reticular formation (PPRF) neurons. Single electrical pulses applied to the PPRF showed a monosynaptic glutamatergic projection on PH neurons, acting on AMPA-kainate receptors. Train stimulation of the PPRF area evoked a sustained depolarization of PH neurons exceeding (by hundreds of milliseconds) stimulus duration. Both duration and amplitude of this sustained depolarization were linearly related to train frequency. The train-evoked sustained depolarization was the result of interaction between glutamatergic excitatory burst neurons and cholinergic mesopontine reticular fibers projecting onto PH neurons, because it was prevented by slice superfusion with cholinergic antagonists and mimicked by cholinergic agonists. As expected, microinjections of cholinergic antagonists in the PH nucleus of alert behaving cats evoked a gaze-holding deficit consisting of a re-centering drift of the eye after each saccade. These findings suggest that a slow, cholinergic, synaptically triggered event participates in the generation of persistent activity characteristic of PH neurons carrying eye position signals

    Exploiting graphic processing units parallelism to improve intelligent data acquisition system performance in JET's correlation reflectometer

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    The performance of intelligent data acquisition systems relies heavily on their processing capabilities and local bus bandwidth, especially in applications with high sample rates or high number of channels. This is the case of the self adaptive sampling rate data acquisition system installed as a pilot experiment in KG8B correlation reflectometer at JET. The system, which is based on the ITMS platform, continuously adapts the sample rate during the acquisition depending on the signal bandwidth. In order to do so it must transfer acquired data to a memory buffer in the host processor and run heavy computational algorithms for each data block. The processing capabilities of the host CPU and the bandwidth of the PXI bus limit the maximum sample rate that can be achieved, therefore limiting the maximum bandwidth of the phenomena that can be studied. Graphic processing units (GPU) are becoming an alternative for speeding up compute intensive kernels of scientific, imaging and simulation applications. However, integrating this technology into data acquisition systems is not a straight forward step, not to mention exploiting their parallelism efficiently. This paper discusses the use of GPUs with new high speed data bus interfaces to improve the performance of the self adaptive sampling rate data acquisition system installed on JET. Integration issues are discussed and performance evaluations are presente

    Gender differences in mental health during the economic crisis

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    Background: Economic crises have a negative effect on mental health. Little evidence has been published on the impact of economic downturns on male and female. The aim of the study was to analyze gender differences in specific mental disorders in primary care during the current economic recession in Spain. Method: A total of 7, 914 patients in 2006 and 5, 876 patients in 2010 were recruited to collect sociodemographic data and the Primary Care Evaluation of Mental Disorders. Results: Between 2006 and 2010 the prevalence of Major Depressive Disorder increased 155.7% in men and 104.9% in women; Generalized Anxiety Disorder increased 98.3% in men and 71.3% in women; and Multisomatoform Disorder increased 100.05% in men and 37% in women. The effect of the Employment confounder was significant across all comparisons: Major Depressive Disorder Generalized Odds Ratio=2.557 for Men (p<.001), 2.046 for Women (p=.002); Generalized Anxiety Disorder Generalized Odds Ratio= 2.153 (p<.001) for Men, 1.546 for Women (p<.001); and for Non-specific Multisomatoform Disorder Generalized Odds Ratio=1.680 for Men (p<.001) and 1.301 for women (p=.014). Conclusion: Overall prevalence of mental disorders increased significantly between 2006 and 2010, especially in males, who are more sensitive to the effect of the current economic recession than women. Antecedentes: el impacto de las crisis económicas sobre la salud mental está bien documentado, pero hay poca evidencia sobre el efecto diferencial que pueda tener entre hombres y mujeres. El objetivo fue analizar las diferencias de género en la prevalencia de trastornos mentales en atención primaria durante la recesión económica en España. Método: 7.914 pacientes en 2006-2007 y 5.876 en 2010-2011 fueron encuestados para recoger datos sociodemográficos y completar la entrevista Primary Care Evaluation of Mental Disorders. Resultados: entre 2006 y 2010 la prevalencia del Trastorno Depresivo Mayor incrementó 155, 7% en hombres y un 104, 9% en mujeres; el Trastorno de Ansiedad Generalizada aumentó 98, 3% en hombres y 71, 3% en mujeres; el Trastorno Multisomatomorfo incrementó 100, 05% en hombres y 37% en mujeres. El desempleo fue significativo en todos los análisis: Trastorno Depresivo Odds Ratio Generalizados= 2.557 en hombres (p<.001), 2.046 en mujeres (p= .002); Trastorno de Ansiedad Generalizada Odds Ratio Generalizados= 2.153 (p<.001) en hombres, 1.546 en mujeres (p<.001); Trastorno Multisomatoformo indiferenciado Odds Ratio Generalizados= 1.680 en hombres (p<.001) y 1.301 en mujeres (p= .014). Conclusiones: la prevalencia de los trastornos mentales se incrementó entre 2006 y 2010 en ambos sexos, pero especialmente en hombres, quienes son más sensibles a los efectos de la crisis económica

    Laughter as a diagnostic measure of psoriasis severity

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    Laughter has been studied for its beneficial effects on health and as a therapeutic method to prevent and treat medical conditions. We explore the predictive potential of laughter as a psoriasis severity diagnostic tool. In this study, the dermatologist first examines the patient and registers the PASI and BSA scores. Then patients complete the DLQI and EQ-5D-3L (quality of life), as well as the HADS (anxiety and depression) and the NEO PI-R (personality traits). Finally, the laughs of 30 patients with plaque psoriasis (15 mild cases and 15 moderate to severe cases), and 30 healthy controls will be registered. To do this, patients and accompanying health controls (in pairs), watch a 15-minute video with humorous sketches..

    Rhodium complexes in p-C bond formation: Key role of a hydrido ligand

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    Olefin hydrophosphanation is an attractive route for the atom-economical synthesis of functionalized phosphanes. This reaction involves the formation of P-C and H-C bonds. Thus, complexes that contain both hydrido and phosphanido functionalities are of great interest for the development of effective and fast catalysts. Herein, we showcase the excellent activity of one of them, [Rh(Tp)H(PMe3)(PPh2)] (1), in the hydrophosphanation of a wide range of olefins. In addition to the required nucleophilicity of the phosphanido moiety to accomplish the P-C bond formation, the key role of the hydride ligand in 1 has been disclosed by both experimental results and DFT calculations. An additional Rh-H··· C stabilization in some intermediates or transition states favors the hydrogen transfer reaction from rhodium to carbon to form the H-C bond. Further support for our proposal arises from the poor activity exhibited by the related chloride complex [Rh(Tp)Cl(PMe3)(PPh2)] as well as from stoichiometric and kinetic studies

    Bibliometric analysis in motorcycle accident research: a global overview

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    770 million motorcycles are estimated on the roads. Motorcyclists represent more than 380,000 annual deaths worldwide. 28% of the global fatalities in the roads in 2016. With the increase of the accident rate, studies have been developed within the scientific literature. Bibliometric analysis is applied in the field of motorcycle safety in order to identify relevant publications on risk factors of road crashes and their implications. The information in this research was extracted from Web of Science and Scopus databases between 1947 and May 31, 2018. The study identified the key bibliometric indicators such as publications, authors, journals, countries, institutions, citation and co-citation analysis, subject categories, and co-occurrence of terms. EndNote, Microsoft Excel, Statgraphics Centurion and VOS-viewer software were used for the analysis. In total, 1813 articles were considered. The publications from 2000 to 2017 exhibits an average growth of 9%. The journal “Accident Analysis and Prevention” was the key issue in the publication and citation. The top institutions were the University of California, Universiti Putra Malaysia, and Monash University. The average citation of the top 10 articles was 134. A network visualization map showed that ‘vehicle’, ‘model’, ‘system’, ‘road’, ‘safety’, and ‘behavior’ were the most commons key terms. Bibliometric analysis demonstrates a high collaboration between authors and institutions. Two growing trends were identified. First, studies on the protection of the motorcyclist and the safe design considering the performance. Second, studies in analysis, characterization, and prevention of accidents. These studies are more related to the generation of strategies for the protection of road safety for motorcyclists
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