506 research outputs found

    Non-profit organizations’ participation in the management of public programmes: The case of the Czech Republic

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    EU Cohesion Policy requires the interaction of public, private and non-profit sectors in policy making. The case of the Czech Republic enables us to identify the major obstacles to the successful implementation of this approach as the Czech population perceives the ability of NGOs to influence policies at the lowest level among all the EU member states. The goal of the study is to identify and explain the determinants of success and failure regarding NGOs’ participation in designing public programmes. The methodology includes a combination of in-depth interviews with NGOs ́' representatives and public servants, a review of official documents, a focus group, and a stakeholders’ review of the study’s conclusions. The main obstacles to the implementation of the partnership principle are the following: insufficient capacities among NGOs; fluctuations in participating public servants and NGO representatives; dependence of partnership on personal contacts; late start and nonconsultative, informative character of partnership

    Python for Large-Scale Electrophysiology

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    Electrophysiology is increasingly moving towards highly parallel recording techniques which generate large data sets. We record extracellularly in vivo in cat and rat visual cortex with 54-channel silicon polytrodes, under time-locked visual stimulation, from localized neuronal populations within a cortical column. To help deal with the complexity of generating and analysing these data, we used the Python programming language to develop three software projects: one for temporally precise visual stimulus generation (“dimstim”); one for electrophysiological waveform visualization and spike sorting (“spyke”); and one for spike train and stimulus analysis (“neuropy”). All three are open source and available for download (http://swindale.ecc.ubc.ca/code). The requirements and solutions for these projects differed greatly, yet we found Python to be well suited for all three. Here we present our software as a showcase of the extensive capabilities of Python in neuroscience

    Pupil size dynamics predict dLGN firing mode over a wide range of timescales

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    Pupil size is a commonly used proxy for waking brain states such as arousal, and has been related to activity modulations in cortical sensory areas. Here, we asked whether the dorsolateral geniculate nucleus (dLGN), which provides sensory input to the visual cortex, is modulated by pupil-indexed arousal. Observing that the pupil size oscillates at multiple timescales, we developed a method to show that the spiking mode of the dLGN is predicted by pupil size oscillations over several of these timescales. Overall, we found that tonic spikes preferentially occurred during pupil dilation, while bursts occurred during contraction. These preferences could not be explained solely by pupil size per se or by the locomotion of the animal, and were also present during periods of stimulus viewing. We conclude that dLGN spiking activity is modulated by pupil-indexed arousal processes on various timescales, influencing the mode in which sensory signals are passed on to the cortex

    The Impacts of Subsidies on Czech Firms

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    In the Czech Republic there has been invested a lot of money to the human capital through the European Social Fund. The Human Resources and Employment Operational Programme plays an important role by providing subsidies for the training of employees and an introduction of modern forms of management and human resource development. This paper summarizes the application of the regression discontinuity method to test whether there is an impact of EU assistance on employment in supported firms in 2009. The estimations were conducted with a sample with 1 176 supported and 87 rejected applicants. The estimation results suggest that the impacts of the intervention on employment is positive and statistically significant. The employment change in supported firms was on average about 10–15 p.p. higher than in unsupported firms

    Robust effects of corticothalamic feedback during naturalistic visual stimulation

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    Neurons in the dorsolateral geniculate nucleus (dLGN) of the thalamus are contacted by a large number of feedback synapses from cortex, whose role in visual processing is poorly understood. Past studies investigating this role have mostly used simple visual stimuli and anesthetized animals, but corticothalamic (CT) feedback might be particularly relevant during processing of complex visual stimuli, and its effects might depend on behavioral state. Here, we find that CT feedback robustly modulates responses to naturalistic movie clips by increasing response gain and promoting tonic firing mode. Compared to these robust effects for naturalistic movies, CT feedback effects on firing rates were less consistent for simple grating stimuli, likely related to differences in spatial context. Finally, while CT feedback and locomotion affected dLGN responses in similar ways, we found their effects to be largely independent. We propose that CT feedback and behavioral state use separate circuits to modulate visual information on its way to cortex in a context-dependent manner

    Robust effects of corticothalamic feedback and behavioral state on movie responses in mouse dLGN

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    Neurons in the dorsolateral geniculate nucleus (dLGN) of the thalamus receive a substantial proportion of modulatory inputs from corticothalamic (CT) feedback and brain stem nuclei. Hypothesizing that these modulatory influences might be differentially engaged depending on the visual stimulus and behavioral state, we performed in vivo extracellular recordings from mouse dLGN while optogenetically suppressing CT feedback and monitoring behavioral state by locomotion and pupil dilation. For naturalistic movie clips, we found CT feedback to consistently increase dLGN response gain and promote tonic firing. In contrast, for gratings, CT feedback effects on firing rates were mixed. For both stimulus types, the neural signatures of CT feedback closely resembled those of behavioral state, yet effects of behavioral state on responses to movies persisted even when CT feedback was suppressed. We conclude that CT feedback modulates visual information on its way to cortex in a stimulus-dependent manner, but largely independently of behavioral state

    In vivo extracellular recordings of thalamic and cortical visual responses reveal V1 connectivity rules

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    The brain’s connectome provides the scaffold for canonical neural computations. However, a comparison of connectivity studies in the mouse primary visual cortex (V1) reveals that the average number and strength of connections between specific neuron types can vary. Can variability in V1 connectivity measurements coexist with canonical neural computations? We developed a theory-driven approach to deduce V1 network connectivity from visual responses in mouse V1 and visual thalamus (dLGN). Our method revealed that the same recorded visual responses were captured by multiple connectivity configurations. Remarkably, the magnitude and selectivity of connectivity weights followed a specific order across most of the inferred connectivity configurations. We argue that this order stems from the specific shapes of the recorded contrast response functions and contrast invariance of orientation tuning. Remarkably, despite variability across connectivity studies, connectivity weights computed from individual published connectivity reports followed the order we identified with our method, suggesting that the relations between the weights, rather than their magnitudes, represent a connectivity motif supporting canonical V1 computations

    Corticothalamic feedback sculpts visual spatial integration in mouse thalamus

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    En route from retina to cortex, visual information travels through the dorsolateral geniculate nucleus of the thalamus (dLGN), where extensive cortico-thalamic (CT) feedback has been suggested to modulate spatial processing. How this modulation arises from direct excitatory and indirect inhibitory CT feedback components remains enigmatic. We show that in awake mice topographically organized cortical feedback modulates spatial integration in dLGN by sharpening receptive fields (RFs) and increasing surround suppression. Guided by a network model revealing wide-scale inhibitory CT feedback necessary to reproduce these effects, we targeted the visual sector of the thalamic reticular nucleus (visTRN) for recordings. We found that visTRN neurons have large receptive fields, show little surround suppression, and have strong feedback-dependent responses to large stimuli, making them an ideal candidate for mediating feedback-enhanced surround suppression in dLGN. We conclude that cortical feedback sculpts spatial integration in dLGN, likely via recruitment of neurons in visTRN

    Bone Fracture Toughness and Strength Correlate With Collagen Cross‐Link Maturity in a Dose‐Controlled Lathyrism Mouse Model

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    Collagen cross‐linking is altered in many diseases of bone, and enzymatic collagen cross‐links are important to bone quality, as evidenced by losses of strength after lysyl oxidase inhibition (lathyrism). We hypothesized that cross‐links also contribute directly to bone fracture toughness. A mouse model of lathyrism using subcutaneous injection of up to 500 mg/kg ÎČ‐aminopropionitrile (BAPN) was developed and characterized (60 animals across 4 dosage groups). Three weeks of 150 or 350 mg/kg BAPN treatment in young, growing mice significantly reduced cortical bone fracture toughness, strength, and pyridinoline cross‐link content. Ratios reflecting relative cross‐link maturity were positive regressors of fracture toughness (HP/[DHLNL + HLNL] r2 = 0.208, p < 0.05; [HP + LP]/[DHNL + HLNL] r2 = 0.196, p < 0.1), whereas quantities of mature pyridinoline cross‐links were significant positive regressors of tissue strength (lysyl pyridinoline r2 = 0.159, p = 0.014; hydroxylysyl pyridinoline r2 = 0.112, p < 0.05). Immature and pyrrole cross‐links, which were not significantly reduced by BAPN, did not correlate with mechanical properties. The effect of BAPN treatment on mechanical properties was dose specific, with the greatest impact found at the intermediate (350 mg/kg) dose. Calcein labeling was used to define locations of new bone formation, allowing for the identification of regions of normally cross‐linked (preexisting) and BAPN‐treated (newly formed, cross‐link‐deficient) bone. Raman spectroscopy revealed spatial differences attributable to relative tissue age and effects of cross‐link inhibition. Newly deposited tissues had lower mineral/matrix, carbonate/phosphate, and Amide I cross‐link (matrix maturity) ratios compared with preexisting tissues. BAPN treatment did not affect mineral measures but significantly increased the cross‐link (matrix maturity) ratio compared with newly formed control tissue. Our study reveals that spatially localized effects of short‐term BAPN cross‐link inhibition can alter the whole‐bone collagen cross‐link profile to a measureable degree, and this cross‐link profile correlates with bone fracture toughness and strength. Thus, cross‐link profile perturbations associated with bone disease may provide insight into bone mechanical quality and fracture risk. © 2014 American Society for Bone and Mineral Research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110745/1/jbmr2356.pd
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