1,213 research outputs found

    Detection of Multiple Pathways in the Spinal Cord White Matter Using Q-Ball Imaging

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    International audienceHigh angular resolution MRI such as q-ball imaging (QBI) allows to recover complex white matter architecture. We applied this technique to an ex vivo spinal cord of one cat using a 3T scanner, 100 directions and b-values varying from 1000 to 3000 s/mm2. As a result, QBI can retrieve crossing fibre information, where the diffusion tensor imaging approach is constrained to a single diffusion direction. To our knowledge, this is the first study demonstrating the benefits of QBI in observing longitudinal, commissural and dorso-ventral fibres in the spinal cord. It is a first step towards in vivo characterization of the healthy and injured spinal cord using high angular resolution diffusion imaging (HARDI) and QBI

    High frequency sampling of the 1984 spring bloom within the mid-Atlantic Bight: Synoptic shipboard, aircraft, and in situ perspectives of the SEEP-I experiment

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    Moorings of current meters, thermistors, transmissometers, and fluorometers on the mid-Atlantic shelf, south of Long Island, suggest a cumulative seaward export of perhaps 0.35 g C/sq m/day between the 80 and 120 m isobaths during February-April 1984. Such a horizontal loss of algal carbon over the lower third of the water column would be 23 to 78% of the March-April 1984 primary production. This physical carbon loss is similar to daily grazing losses from zooplankton of 32-40% of the algal fixation of carbon. Metabolic demands of the benthos could be met by just the estimated fecal pellet flux, without direct consumption of algal carbon, while bacterioplankton needs could be served by excretory release of dissolved organic matter during photosynthesis. Sediment traps tethered 10 m off the bottom at the 120 m isobath and 50 m above the 500 m isobath caught as much as 0.16 to 0.26 g C /sq m/day during March-April 1984, in reasonable agreement with the flux estimated from the other moored instruments

    Not fitting in and getting out : psychological type and congregational satisfaction among Anglican churchgoers in England

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    Listening to the motivations reported by individuals for ceasing church attendance and becoming church leavers, Francis and Richter identified high on the list the sense of "not fitting in". Drawing on psychological type theory, several recent studies have documented the way in which some psychological types are over-represented in church congregations and other psychological types are under-represented. Bringing these two observations together, the present study tested the hypothesis that church congregations have created type-alike communities within which individuals displaying the opposite type preferences are more likely to feel marginalised and to display lower levels of satisfaction with the congregations they attend. Data were provided by 1867 churchgoers who completed a measure of psychological type, together with measures of frequency of attendance and congregational satisfaction. These data confirmed that congregations were weighted towards preferences for introversion, sensing, feeling and judging, and that individuals displaying the opposite preferences (especially intuition, thinking and perceiving) recorded lower levels of congregational satisfaction. The implications of these findings are discussed for promoting congregational retention by enhancing awareness of psychological type preferences among those who attend

    Climbing Fiber Burst Size and Olivary Sub-threshold Oscillations in a Network Setting

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    The inferior olivary nucleus provides one of the two main inputs to the cerebellum: the so-called climbing fibers. Activation of climbing fibers is generally believed to be related to timing of motor commands and/or motor learning. Climbing fiber spikes lead to large all-or-none action potentials in cerebellar Purkinje cells, overriding any other ongoing activity and silencing these cells for a brief period of time afterwards. Empirical evidence shows that the climbing fiber can transmit a short burst of spikes as a result of an olivary cell somatic spike, potentially increasing the information being transferred to the cerebellum per climbing fiber activation. Previously reported results from in vitro studies suggested that the information encoded in the climbing fiber burst is related to the occurrence of the spike relative to the ongoing sub-threshold membrane potential oscillation of the olivary cell, i.e. that the phase of the oscillation is reflected in the size of the climbing fiber burst. We used a detailed three-compartmental model of an inferior olivary cell to further investigate the possible factors determining the size of the climbing fiber burst. Our findings suggest that the phase-dependency of the burst size is present but limited and that charge flow between soma and dendrite is a major determinant of the climbing fiber burst. From our findings it follows that phenomena such as cell ensemble synchrony can have a big effect on the climbing fiber burst size through dendrodendritic gap-junctional coupling between olivary cells

    Are juveniles who have committed sexual offenses the same everywhere? psychometric properties of the juvenile sex offender assessment protocol–II in a portuguese youth sample

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    Over the last decade, we have witnessed consistent advances in risk assessment procedures, namely the validation of those used with juveniles who have committed sexual offenses. The adaptation of these instruments into other languages requires research examining the conceptual and metric equivalence of the instruments, not just translation equivalence. Informed by data from 141 boys, aged 13 to 18, the psychometric properties of the Portuguese version of the Juvenile Sex Offender Assessment Protocol–II (J-SOAP-II), regarding reliability and construct validation, are presented and discussed. Factor structure, internal consistency, and interrater reliability were examined, and a reliable factorial structure that was consistent with the original validation of the J-SOAP was found. Scales 2 and 3 had good internal consistency, and Scale 1 had acceptable internal consistency. Results regarding concurrent validity revealed mostly statistically significant correlations. The implications of this research for juvenile sex offender risk assessments are discussed.The author(s) received no financial support for the research, authorship, and/or publication of this article

    Do All Lives Have the Same Value? Support for International Military Interventions as a Function of Political System and Public Opinion of the Target States

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    This research examined the support for international military interventions as a function of the political system and the public opinion of the target country. In two experiments, we informed participants about a possible military intervention by the international community towards a sovereign country whose government planned to use military force against a secessionist region. They were then asked whether they would support this intervention whilst being reminded that it would cause civilian deaths. The democratic or nondemocratic political system of the target country was experimentally manipulated, and the population support for its belligerent government policy was either assessed (Experiment 1) or manipulated (Experiment 2). Results showed greater support for the intervention when the target country was nondemocratic, as compared to the democratic and the control conditions, but only when its population supported the belligerent government policy. Support for the external intervention was low when the target country was democratic, irrespective of national public opinion. These findings provide support for the democracy-as-value hypothesis applied to international military interventions, and suggest that civilian deaths (collateral damage) are more acceptable when nondemocratic populations support their government's belligerent policy

    The Neutron star Interior Composition Explorer (NICER): design and development

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    Suspension cultured transgenic cells of Nicotiana tabacum expressing tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus produce strictosidine upon secologanin feeding

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    A transgenic cell suspension culture of Nicotiana tabacum L. ‘Petit Havana’ SR1 was established expressing tryptophan decarboxylase and strictosidine synthase cDNA clones from Catharanthus roseus (L.) G. Don under the direction of cauliflower mosaic virus 35S promoter and nopaline synthase terminator sequences. During a growth cycle, the transgenic tobacco cells showed relatively constant tryptophan decarboxylase activity and an about two- to sixfold higher strictosidine synthase activity, enzyme activities not detectable in untransformed tobacco cells. The transgenic culture accumulated tryptamine and produced strictosidine upon feeding of secologanin, demonstrating the in vivo functionality of the two transgene-encoded enzymes. The accumulation of strictosidine, which occurred predominantly in the medium, could be enhanced by feeding both secologanin and tryptamine. No strictosidine synthase activity was detected in the medium, indicating the involvement of secologanin uptake and strictosidine release by the cells.info:eu-repo/semantics/publishedVersio

    Suspension cultured transgenic cells of Nicotiana tabacum expressing tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus produce strictosidine upon secologanin feeding

    Get PDF
    A transgenic cell suspension culture of Nicotiana tabacum L. ‘Petit Havana’ SR1 was established expressing tryptophan decarboxylase and strictosidine synthase cDNA clones from Catharanthus roseus (L.) G. Don under the direction of cauliflower mosaic virus 35S promoter and nopaline synthase terminator sequences. During a growth cycle, the transgenic tobacco cells showed relatively constant tryptophan decarboxylase activity and an about two- to sixfold higher strictosidine synthase activity, enzyme activities not detectable in untransformed tobacco cells. The transgenic culture accumulated tryptamine and produced strictosidine upon feeding of secologanin, demonstrating the in vivo functionality of the two transgene-encoded enzymes. The accumulation of strictosidine, which occurred predominantly in the medium, could be enhanced by feeding both secologanin and tryptamine. No strictosidine synthase activity was detected in the medium, indicating the involvement of secologanin uptake and strictosidine release by the cells.info:eu-repo/semantics/publishedVersio

    A review on substances and processes relevant for optical remote sensing of extremely turbid marine areas, with a focus on the Wadden Sea

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    The interpretation of optical remote sensing data of estuaries and tidal flat areas is hampered by optical complexity and often extreme turbidity. Extremely high concentrations of suspended matter, chlorophyll and dissolved organic matter, local differences, seasonal and tidal variations and resuspension are important factors influencing the optical properties in such areas. This review gives an overview of the processes in estuaries and tidal flat areas and the implications of these for remote sensing in such areas, using the Wadden Sea as a case study area. Results show that remote sensing research in extremely turbid estuaries and tidal areas is possible. However, this requires sensors with a large ground resolution, algorithms tuned for high concentrations of various substances and the local specific optical properties of these substances, a simultaneous detection of water colour and land-water boundaries, a very short time lag between acquisition of remote sensing and in situ data used for validation and sufficient geophysical and ecological knowledge of the area. © 2010 The Author(s)
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