543 research outputs found

    Modeled changes of cerebellar activity in mutant mice are predictive of their learning impairments

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    Translating neuronal activity to measurable behavioral changes has been a long-standing goal of systems neuroscience. Recently, we have developed a model of phase-reversal learning of the vestibulo-ocular reflex, a well-established, cerebellar-dependent task. The model, comprising both the cerebellar cortex and vestibular nuclei, reproduces behavioral data and accounts for the changes in neural activity during learning in wild type mice. Here, we used our model to predict Purkinje cell spiking as well as behavior before and after learning of five different lines of mutant mice with distinct cell-specific alterations of the cerebellar cortical circuitry. We tested these predictions by obtaining electrophysiological data depicting changes in neuronal spiking. We show that our data is largely consistent with the model predictions for simple spike modulation of Purkinje cells and concomitant behavioral learning in four of the mutants. In addition, our model accurately predicts a shift in simple spike activity in a mutant mouse with a brainstem specific mutation. This combination of electrophysiological and computational techniques opens a possibility of predicting behavioral impairments from neural activity

    Cerebellar Codings for Control of Compensatory Eye Movements

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    This thesis focuses on the control of the cerebellum on motor behaviour, and more specifically on the role of the cerebellar Purkinje cells in exerting this control. As the cerebellum is an online control system, we look at both motor performance and learning, trying to identify components involved at the molecular, cellular and network level. To study the cerebellum we used the vestibulocerebellum, with visual and vestibular stimulation as input and eye movements as recorded output. The advantage of the vestibulocerebellum over other parts is that the input given is highly controllable, while the output can be reliably measured, and performance and learning can be easily studied. In addition, we conducted electrophysiological recordings from the vestibulocerebellum, in particular of Purkinje cells in the flocculus. Combining the spiking behaviour of Purkinje cells with visual input and eye movement output allowed us to study how the cerebellum functions and using genetically modified animals we could determine the role of different elements in this system. To provide some insights in the techniques used and the theory behind them, we will discuss the following topics in this introduction: compensatory eye movements, the anatomy of pathways to, within and out of the flocculus, the cellular physiology of Purkinje cells in relation to performance and the plasticity mechanisms related to motor learning

    Мерчандайзинг як партнерська взаємодія виробника та роздробу

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    У даній статті розглянуто мерчандайзинг як елемент комплексу маркетингових комунікацій, задачі та функції мерчандайзингу для виробника та для роздрібного торговця, їх точки пересічення та розбіжності, висувається припущення про їх взаємодію по цьому питанню, що може збільшити ефект, що очікується від використання методів мерчандайзингу в місцях продажу, як для виробника, так і для магазину.In this article merchandising is considered. Its task and functions for a producer and for a retail dealer, their intersection and divergence. There are also pulled out supposition about their cooperation in this field, what can increase an effect, which is expected from merchandising methods using to both in the places of sale

    Modeled changes of cerebellar activity in mutant mice are predictive of their learning impairments

    Get PDF
    Translating neuronal activity to measurable behavioral changes has been a long-standing goal of systems neuroscience. Recently, we have developed a model o

    Blood group probabilities by next of kin

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    For rare blood groups the recruitment of donor relatives, for example siblings, is expected to be effective, since the probability of a similar rare blood group is likely. However, the likelihood differs between blood groups and is not commonly available. This paper provides a unified mathematical formulation to calculate such likelihoods. From a mathematical and probabilistic point of view, it is shown that these likelihoods can be obtained from the computation of a stationary genotype distribution. This, in turn, can be brought down to a system of quadratic stochastic operators. A generic mathematical approach is presented which directly leads to a stationary genotype distribution for arbitrary blood groups. The approach enables an exact computation for the effectiveness of recruiting next of kin for blood donorship. Next to an illustration of computations for ‘standard’ ABO and Rhesus-D blood groups, it is particularly illustrated for the extended Rhesus blood group system. Also other applications requiring next of kin blood group associations can be solved directly by using the unified mathematical formulation

    Comparing Single-Incision Midurethral Sling with Bulking Agents for Female Stress Urinary Incontinence:Rationale for a Non-Randomized Controlled Trial

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    Objectives: Midurethral slings are considered the gold standard for the surgical treatment of stress urinary incontinence (SUI), with an efficacy up to 80%. Another therapeutic option is the use of bulking agents, which create an artificial mass in the urethral submucosa, with an efficacy varying from 64% to 74%. Although bulking agents have a lower risk of complications than midurethral sling surgery, they are mainly used in case a midurethral sling is not an option or if midurethral sling surgery failed to cure stress urinary incontinence. In this study, we offer all patients with SUI in secondary care a choice between a single-incision midurethral sling procedure and treatment with a bulking agent. We want to examine patient preference and patient satisfaction for both procedures. We expect that offering both interventions in combination with standardized counselling will result in high patient satisfaction. Design: In this non-randomized controlled trial, 266 patients will be objectively counselled for both interventions, after which all patients will choose between single-incision midurethral slings and polyacrylamide hydrogel (PAHG), followed by the standard care procedure for women with SUI. Participants/Materials, Setting, Methods: From January 1, 2021, onward, all consecutive adult patients (between 18 and 80 years of age) attending the outpatient gynaecology department with objectively confirmed, moderate to severe SUI will be eligible for enrolment in this non-randomized study. The primary outcome is patient satisfaction at 1 year, measured by the Patient Global Impression of Improvement; secondary outcomes are patient satisfaction at 3 months, objective and subjective cure at 3 months and 1 year, adverse events, post-operative pain, and cost-effectiveness. Differences in outcome measures will be assessed through logistic and linear regression analyses, both unadjusted and adjusted with covariate adjustment using the propensity score. Results: No results are available yet. Limitations: The major disadvantage of this study design is the potential confounding bias. We intend to eliminate this bias by applying propensity scoring. Conclusion: By designing a non-randomized patient preference trial, we not only expect to demonstrate high patient satisfaction with both interventions but also provide insight into the possible role of PAHG-injections in the treatment of female SUI as a first-choice non-conservative treatment.</p

    Intestinal barrier function in response to abundant or depleted mucosal glutathione in Salmonella-infected rats

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    ABSTRACT: BACKGROUND: Glutathione, the main antioxidant of intestinal epithelial cells, is suggested to play an important role in gut barrier function and prevention of inflammation-related oxidative damage as induced by acute bacterial infection. Most studies on intestinal glutathione focus on oxidative stress reduction without considering functional disease outcome. Our aim was to determine whether depletion or maintenance of intestinal glutathione changes susceptibility of rats to Salmonella infection and associated inflammation. Rats were fed a control diet or the same diet supplemented with buthionine sulfoximine (BSO; glutathione depletion) or cystine (glutathione maintenance). Inert chromium ethylenediamine-tetraacetic acid (CrEDTA) was added to the diets to quantify intestinal permeability. At day 4 after oral gavage with Salmonella enteritidis (or saline for non-infected controls), Salmonella translocation was determined by culturing extra-intestinal organs. Liver and ileal mucosa were collected for analyses of glutathione, inflammation markers and oxidative damage. Faeces was collected to quantify diarrhoea. RESULTS: Glutathione depletion aggravated ileal inflammation after infection as indicated by increased levels of mucosal myeloperoxidase and interleukin-1beta. Remarkably, intestinal permeability and Salmonella translocation were not increased. Cystine supplementation maintained glutathione in the intestinal mucosa but inflammation and oxidative damage were not diminished. Nevertheless, cystine reduced intestinal permeability and Salmonella translocation. CONCLUSIONS: Despite increased infection-induced mucosal inflammation upon glutathione depletion, this tripeptide does not play a role in intestinal permeability, bacterial translocation and diarrhoea. On the other hand, cystine enhances gut barrier function by a mechanism unlikely to be related to glutathione
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