34 research outputs found

    How spiking neurons give rise to a temporal-feature map

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    A temporal-feature map is a topographic neuronal representation of temporal attributes of phenomena or objects that occur in the outside world. We explain the evolution of such maps by means of a spike-based Hebbian learning rule in conjunction with a presynaptically unspecific contribution in that, if a synapse changes, then all other synapses connected to the same axon change by a small fraction as well. The learning equation is solved for the case of an array of Poisson neurons. We discuss the evolution of a temporal-feature map and the synchronization of the single cells’ synaptic structures, in dependence upon the strength of presynaptic unspecific learning. We also give an upper bound for the magnitude of the presynaptic interaction by estimating its impact on the noise level of synaptic growth. Finally, we compare the results with those obtained from a learning equation for nonlinear neurons and show that synaptic structure formation may profit from the nonlinearity

    Association of a Public Health Campaign About Coronavirus Disease 2019 Promoted by News Media and a Social Influencer With Self-reported Personal Hygiene and Physical Distancing in the Netherlands

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    Importance: In the absence of a vaccine and therapeutic agent, personal hygiene and physical distancing are essential measures to contain the coronavirus disease 2019 pandemic. Objective: To determine whether a social media campaign, targeted at the gaps in behavior on personal hygiene and physical distancing and distributed nationwide via digital news media, may be an effective method to improve behavior and help to inhibit person-to-person transmission of severe acute respiratory syndrome coronavirus 2. Design, Setting, and Participants: This survey study was designed to uncover self-reported gaps in behavior regarding personal hygiene and physical distancing in the Netherlands. A diagnostic survey was distributed by a large national newspaper (De Telegraaf) and a popular social influencer (Govert Sweep) on March 17, 2020, and was completed by 16 072 participants. Analysis of these outcomes showed that coughing and sneezing in the elbow was done well, but that handwashing, face touching, and physical distancing showed serious gaps compared with advised behavior. This diagnostic information was used to design infographics and a video targeted at repairing these gaps in behavior. The video and infographics were distributed on a national level on March 21, 2020, followed by a postcampaign survey to measure the results on March 24, 2020. Data analysis was performed from March to April 2020. Exposure: Exposed participants were those who viewed the infographics and/or video. Main Outcomes and Measures: Improvement on the extent of handwashing in all areas, handwashing duration of 20 seconds or longer, awareness on face touching, and physical distancing were measured according to responses on the postcampaign survey. Results: A total of 17 189 participants (mean [SD] age, 47.61 [13.57] years; 9100 women [52.9%]) responded to the postcampaign survey. The news article in De Telegraaf was read more than 2 million times, and the influencer video was watched more than 80 000 times. Cross-sectional analysis of the postcampaign survey using logistic regression correcting for age, gender, and educational level showed that exposure to the video plus infographics (827 participants) (adjusted odds ratio [OR], 2.14; 95% CI, 1.83-2.50; P < .001) and to the infographics alone (11 348 participants) (adjusted OR, 1.31; 95% CI, 1.22-1.40; P < .001) were positively associated with washing hands in all areas compared with the unexposed group (4751 participants). In addition, exposure to the video plus infographics (adjusted OR, 1.86; 95% CI, 1.59-2.16; P < .001) and to the infographics alone (adjusted OR, 1.27; 95% CI, 1.19-1.36; P < .001) were positively associated with washing hands long enough compared with the unexposed group. Exposure to the video alone was not associated with improved handwashing. Compared with the unexposed group, exposure to the infographics alone and video plus infographics were associated with improvements in physical distancing when the participant had COVID-19 syptoms (infographics alone, adjusted OR, 1.10; 95% CI, 1.03-1.17; P = .006; video plus infographics, adjusted OR, 0.79; 95% CI, 0.69-0.91; P = .001) and face touching

    High prevalence of hand- and wrist-related symptoms, impairments, activity limitations and participation restrictions in children with juvenile idiopathic arthritis

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    To determine the prevalence of hand- and wrist-related symptoms and impairments, with resulting activity limitations and participation restrictions in children being treated for juvenile idiopathic arthritis. Cohort study of children, diagnosed in our hospitals between 2003 and 2008 with juvenile idiopathic arthritis, who received standard treatment with regular follow-ups in the same institutions. Patients were asked about hand and wrist symptoms, and underwent a standardized physical examination. For activity limitations, they were asked to complete the Dutch version of the Childhood Health Assessment Questionnaire (CHAQ). Concerning participation restrictions, children were asked about any hand- and/or wrist-related difficulties during daily activities. Of all 152 eligible patients, 121 (80%) participated in the study; 34 boys and 87 girls, mean age 13.7 years (standard deviation (SD) 4.2), mean disease duration 2.6 years (SD 1.4), mean Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71) score 8 (SD 8), indicating low disease activity. Of these 121, 84 (69%) had at least 1 symptom and 40% had at least 1 impairment. The median CHAQ-total score was 0.5 (mean 0.75 (SD 0.77)), indicating mild-to-moderate activity limitations; and 54% reported having hand- and/or wrist-related problems at school. Despite low disease activity, many children appeared to have hand- and/or wrist-related symptoms and impairments, with resulting moderate to severe levels of activity limitations and participation restrictions at schoo

    Proton pump inhibitors and the risk of colorectal cancer

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    INTRODUCTION: Proton pump inhibitor (PPI) use is associated with increased serum gastrin levels and bacterial overgrowth, resulting in more toxic bile salt formation. Concern has risen that these factors may increase the risk of developing colorectal neoplasia. AIM: To investigate the association between the use of PPIs and the risk of colorectal cancer. METHODS: A population-based case-control study was conducted within the Dutch Primary Care Information (IPCI) database over the period 1996-2005. Cases with colorectal cancer were matched with up to 20 controls on age, gender, calendar time, and duration of follow-up prior to diagnosis. Cumulative exposure to PPIs was assessed in the 5 yr prior to diagnosis with a 1-yr lag time analysis. We calculated adjusted odds ratios (OR) with 95% confidence intervals (95% CI) using multivariate, conditional logistic regression analysis. RESULTS: Within the source population of 457,024 persons, we identified 595 colorectal cancer cases. The odds of colorectal cancer were not increased among patients ever using PPIs compared with patients who never used PPIs (OR 0.85, 95% CI 0.63-1.16). Also, the use of PPIs for > 365 days was not associated with a greater risk of colorectal cancer (OR 0.79, 95% CI 0.44-1.41) compared with nonusers. The odds of colorectal cancer in neither the right nor the left hemicolon were significantly increased in patients using PPIs. CONCLUSION: The present study indicates no association between PPI use and the risk of colorectal cancer. Larger numbers of long-term PPI users are needed to confirm the absence of a risk-increasing effect of long-term PPI exposur
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