Τρίτη, 12 Απριλίου 2016

Neural control of visual search by frontal eye field: chronometry of neural events and race model processes

We investigated the chronometry of neural processes in frontal eye fields of macaques performing double-step saccade visual search in which a conspicuous target changes location in the array on a random fraction of trials. Durations of computational processes producing a saccade to original and final target locations (GO1 and GO2, respectively) are derived from response times (RT) on different types of trials. In these data, GO2 tended to be faster than GO1, demonstrating that inhibition of the initial saccade did not delay production of the compensated saccade. Here, we measured the dynamics of visual, visuomovement, and movement neuron activity in relation to these processes by examining trials when neurons instantiated either process. First, we verified that saccades were initiated when the discharge rate of movement neurons reached a threshold that was invariant across RT and trial type. Second, the time when visual and visuomovement neurons selected the target and when movement neuron activity began to accumulate were not significantly different across trial type. Third, the interval from the beginning of accumulation to threshold of movement-related activity was significantly shorter when instantiating the GO2 relative to the GO1 process. Differences observed between monkeys are discussed. Fourth, random variation of RT was accounted for to some extent by random variation in both the onset and duration of selective activity of each neuron type but mostly by variation of movement neuron accumulation duration. These findings offer new insights into the sources of control of target selection and saccade production in dynamic environments.



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Pooled, but not single-neuron, responses in macaque V4 represent a solution to the stereo correspondence problem

Binocular disparity is an important cue for depth perception. To correctly represent disparity, neurons must find corresponding visual features between the left- and right-eye images. The visual pathway ascending from V1 to inferior temporal cortex solves the correspondence problem. An intermediate area, V4, has been proposed to be a critical stage in the correspondence process. However, the distinction between V1 and V4 is unclear, because accumulating evidence suggests that the process begins within V1. In this article, we report that the pooled responses in macaque V4, but not responses of individual neurons, represent a solution to the correspondence problem. We recorded single-unit responses of V4 neurons to random-dot stereograms of varying degrees of anticorrelation. To achieve gradual anticorrelation, we reversed the contrast of an increasing proportion of dots as in our previous psychophysical studies, which predicted that the neural correlates of the solution to correspondence problem should gradually eliminate their disparity modulation as the level of anticorrelation increases. Inconsistent with this prediction, the tuning amplitudes of individual V4 neurons quickly decreased to a nonzero baseline with small anticorrelation. By contrast, the shapes of individual tuning curves changed more gradually so that the amplitude of population-pooled responses gradually decreased toward zero over the entire range of graded anticorrelation. We explain these results by combining multiple energy-model subunits. From a comparison with the population-pooled responses in V1, we suggest that disparity representation in V4 is distinctly advanced from that in V1. Population readout of V4 responses provides disparity information consistent with the correspondence solution.



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Perceiving and acting upon weight illusions in the absence of somatosensory information

When lifting novel objects, individuals' fingertip forces are influenced by a variety of cues such as volume and apparent material. This means that heavy-looking objects tend to be lifted with more force than lighter-looking objects, even when they weigh the same amount as one another. Expectations about object weight based on visual appearance also influence how heavy an object feels when it is lifted. For instance, in the "size-weight illusion," small objects feel heavier than equally weighted large objects. Similarly, in the "material-weight illusion," objects that seem to be made from light-looking materials feel heavier than objects of the same weight that appear to be made from heavy-looking materials. In this study, we investigated these perceptual and sensorimotor effects in IW, an individual with peripheral deafferentation (i.e., a loss of tactile and proprioception feedback). We examined his perceptions of heaviness and fingertip force application over repeated lifts of objects that varied in size or material properties. Despite being able to report real weight differences, IW did not appear to experience the size- or material-weight illusions. Furthermore, he showed no evidence of sensorimotor prediction based on size and material cues. The results are discussed in the context of forward models and their possible influence on weight perception and fingertip force control.



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A quantitative confidence signal detection model: 1. Fitting psychometric functions

Perceptual thresholds are commonly assayed in the laboratory and clinic. When precision and accuracy are required, thresholds are quantified by fitting a psychometric function to forced-choice data. The primary shortcoming of this approach is that it typically requires 100 trials or more to yield accurate (i.e., small bias) and precise (i.e., small variance) psychometric parameter estimates. We show that confidence probability judgments combined with a model of confidence can yield psychometric parameter estimates that are markedly more precise and/or markedly more efficient than conventional methods. Specifically, both human data and simulations show that including confidence probability judgments for just 20 trials can yield psychometric parameter estimates that match the precision of those obtained from 100 trials using conventional analyses. Such an efficiency advantage would be especially beneficial for tasks (e.g., taste, smell, and vestibular assays) that require more than a few seconds for each trial, but this potential benefit could accrue for many other tasks.



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Anaemia in patients with inflammatory bowel disease - a nationwide cross-sectional study

Digestion

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Clostridium difficile infection: A model for disruption of the gut microbiota equilibrium

Digestive Diseases

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Racial and socioeconomic disparities in gastrostomy tube placement after intracerebral hemorrhage in the United States

Stroke

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Challenges and opportunities in the management of chronic hepatitis B infection

International Journal of Infectious Diseases

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Association of maternal diabetes/glycosuria and pre-pregnancy body mass index with offspring indicators of non-alcoholic fatty liver disease

BMC Pediatrics

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TNF-alpha promotes lymphangiogenesis and lymphatic metastasis of gallbladder cancer through the ERK1/2/AP-1/VEGF-D pathway

BMC Cancer

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Quantifying rigidity of Parkinson's disease in relation to laxative treatment: a service evaluation

British Journal of Clinical Pharmacology

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Evaluation of Rabies Suspected Bites in an Immunization Center

2016-04-12T02-23-17Z
Source: TAF Preventive Medicine Bulletin
Duran Tok, Mutahher Akçaer, Ömer Çoşkun, Ahmet Karakaş, Yavuz Çekli.
Rabies is a fatal viral disease. Timely and appropriate vaccination is of vital importance in preventing this disease. The Rabies Field Guide has been prepared by the Ministry of Health of Turkey and implemented in 20214. This guide has developed a standardized nationwide approach to injuries with a rabies risk. The present study explored characteristics of patients that presented to our vaccination center for rabies prophylaxis, reasons for prophylaxis, prophylaxis approach employed, and the rate of compliance to prophylaxis. Materials and Methods: The study included patients who presented to our vaccination center between 2010 and 2012 due to contact with mammals suspected of rabies. Age, gender, site of the bite, previous vaccination status, adherence to vaccination schedule, vaccination schedule employed, type and vaccination status of the attacking animal were recorded on the forms. Results: A total of 591 patients (444 males, 75.1%), who were admitted for vaccination between 2010 and 2012, and who had accessible data, were included in the study. The mean age was 23.82±14.86 years (minimum-maximum: 1-83 years). Of these patients, 97.5% presented after exposure, while 2.5% presented for prophylaxis before exposure. The animals involved in these injuries were dogs in 50.9% and cats in 42.1%. Three cases were medical personnel at the department of forensic medicine that presented for prophylaxis after performing an autopsy to a patient who died from rabies. When the patients were evaluated according to age groups, 48.2% were in the 16-30 years age group. The affected body site was upper extremity in 63.8% of the injuries, lower extremity in 26.1%, head-neck region in 3.2%, and trunk in 1.9%. When the time between the injury and presentation to the hospital was evaluated, 73.6% of the cases presented in the same day, 25% presented between days 1 and 6, and 1.3% presented between days 7 and 15. After exposure, 54% of the patients received 5 doses, 46% received 3 doses, and 4.2% of the patients additionally received rabies hyperimmunoglobulin. Conclusion: The patients presented to our center due to suspected exposure to rabies mostly consisted of young individuals. Dogs were the most frequent animals involved in these injuries. Vaccination of the petted cats and dogs using a particular vaccination schedule, and breeding of stray animals are particularly important in combat with rabies. One fourth of the cases presented to our center days after the exposure. Public awareness campaigns must be conducted by the health authorities due to the fact that administration of prophylaxis as soon as possible after exposure.


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The statistical properties of gene-set analysis

Nature Reviews Genetics. doi:10.1038/nrg.2016.29

Authors: Christiaan A. de Leeuw, Benjamin M. Neale, Tom Heskes & Danielle Posthuma



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Genetic screens: Combination screens for combination therapies

Nature Reviews Genetics. doi:10.1038/nrg.2016.52

Author: Darren J. Burgess



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Small RNAs: Regulating transgenerational epigenetics

Nature Reviews Genetics. doi:10.1038/nrg.2016.51

Author: Denise Waldron



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Synthetic biology: Automating genetic circuit design

Nature Reviews Genetics. doi:10.1038/nrg.2016.50

Author: Ross Cloney



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Investigation of the Impact of Art Therapy Methodology Applied to the Elderly Individuals with Dementia on Cognitive State

2016-04-12T01-52-11Z
Source: Journal of Contemporary Medicine
Serap Bulduk, Yeliz Dinçer, Esra Usta, Sevgi Bayram.
Purpose: Dementia is one of the most important health problems on a global scale. The fact that the treatment options and their effectiveness led to studies about enhancing the quality of life through non-pharmacological interventions. The impacts of the art therapy, one of such interventions, on the mood and cognitive features of the elderly with dementia has been investigated within the scope of various studies. In line with this, this study was conducted on 16 elderly individuals with slight dementia in order to investigate the impact of art therapy technique that is applied to the elderly on the cognitive state of elderly individuals with slight dementia as a quasi-experimental study. Material and method: The data of the study was collected through Individual Information Form, which was prepared by the researchers and the Standardized Mini-Mental Test (SMMT). During the study, Art Therapy was implemented by a researcher who received education on art using such techniques as painting, sculpture, painting objects-living things, collage, etc. Conclusion: The average age of the participants is 73.0±7.70. The mean score of the elderly from the SMMT before art therapy implementation is 21, while this figure is 20 three months after the implementation. These scores are in the reference interval of slight dementia For the SMMT and no significant change was observed following the implementation. Considering the progressive feature of the disease, the fact that the SMMT scores of the elderly did not regularly in small groups of elderly individuals with dementia, it becomes a significant acquisition for their socialization.


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Patient-Controlled Analgesia Plus Background Opioid Infusion for Postoperative Pain in Children: A Systematic Review and Meta-Analysis of Randomized Trials.

BACKGROUND: Bolus administration of opioids via a patient-controlled analgesia (PCA) device is widely used in the postoperative pediatric population. PCA devices have been shown to provide superior analgesia and greater patient satisfaction compared with intermittent administration. Studies comparing the efficacy of PCA with and without a background infusion for postoperative analgesia in children vary considerably in terms of dosing and methodologic quality, making it difficult for practitioners to derive clinically useful information. The purpose of this meta-analysis was to assess whether the addition of a background infusion to PCA bolus administration of an opioid analgesic is more effective (defined as lower pain scores) than PCA bolus alone in the postoperative population specific to children. METHODS: We searched Medline, Embase, and CENTRAL from inception to January 2015 for registered and ongoing trials included in the meta-Register of Controlled Trials and ClinicalTrials.gov, and reference lists of review articles and included articles. Study selection was randomized controlled studies comparing PCA bolus with PCA bolus plus background infusion for postoperative analgesia in children aged 0 to 18 years and adolescents aged 13 to 21 years undergoing any form of surgery that used patient-reported pain scores as an outcome measure. Two reviewers independently extracted data on patient and study characteristics, interventions, and outcomes from included studies using standardized data extraction forms. Seven trials met our eligibility criteria. Data were analyzed using Review Manager version 5.3. Meta-analyses were performed for outcomes that were defined similarly and reported in 2 or more studies, including patient-reported pain scores, nausea and/or vomiting, sedation, and opioid consumption. We independently assessed the risk of bias for each outcome and the certainty in the estimates of effect for critically important outcomes (pain scores, nausea and/or vomiting, excessive sedation) using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Subgroup analyses based on dose of background infusion (high versus low dose) and risk of bias (low versus high/unclear) were performed. RESULTS: There were no significant differences found with respect to pain scores 12 and 24 hours after surgery, opioid consumption, or risk of adverse events with the addition of a background opioid infusion to PCA opioid bolus doses. The quality of the evidence was deemed to be low to very low. CONCLUSIONS: There was no significant difference in outcomes with the addition of an opioid background infusion to PCA bolus doses of opioid. Further high-quality studies are required. (C) 2016 International Anesthesia Research Society

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The challenges of implementing electronic health records for anesthesia use outside the operating room.

Purpose of review: The nonoperating room environment presents a number of distinct challenges for anesthesiologists in the implementation of electronic health records (EHRs). These include documentation compliance, billing, and room design. Recent findings: EHRs offer multiple opportunities for improved continuity of care, expedited preoperative evaluation, and seamless transitions between anesthesia and nonanesthesia providers. Additionally, data gathered through adoption of EHRs provide the promise of future analysis and research, allowing for data-driven improvements in quality of care and value optimization. Institutions adopting a new EHR in areas where anesthesia is provided outside of the operating room should plan wisely to address these matters. Summary: The needs of anesthesiology practice should be carefully incorporated into future EHR builds as demands for anesthesia care outside of the operating room expand. Copyright (C) 2016 YEAR Wolters Kluwer Health, Inc. All rights reserved.

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