114 research outputs found

    Response of Spiking Neurons to Correlated Inputs

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    The effect of a temporally correlated afferent current on the firing rate of a leaky integrate-and-fire (LIF) neuron is studied. This current is characterized in terms of rates, auto and cross-correlations, and correlation time scale τc\tau_c of excitatory and inhibitory inputs. The output rate νout\nu_{out} is calculated in the Fokker-Planck (FP) formalism in the limit of both small and large τc\tau_c compared to the membrane time constant τ\tau of the neuron. By simulations we check the analytical results, provide an interpolation valid for all τc\tau_c and study the neuron's response to rapid changes in the correlation magnitude.Comment: 4 pages, 3 figure

    Confrontational Behavior and Escalation to War 1816-1980: A Research Plan

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    The understanding of international war, like many complex social events, may be - and has been - ap proached from a range of theoretical perspectives and via a variety of research strategies. Outside of the work of Bloch (1898), Sorokin (1936), Richardson (1941), and Wright (1942), however, there was little re search of a scientific nature until the mid-1960s. And while these past fifteen years have certainly not given us a compelling theory of international war, they have seen a steady growth in cumulative knowledge regar ding the correlates of war. These results, despite the expected mix of inconsistencies and anomalies, provide us with some sense of the factors that are most consistently associated with war over the last century and a half, along with some tentative insights into the rising and declining potency of these factors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68556/2/10.1177_002234338201900104.pd

    Texas Lifestyle Limits Transmission of Dengue Virus

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    Urban dengue is common in most countries of the Americas, but has been rare in the United States for more than half a century. In 1999 we investigated an outbreak of the disease that affected Nuevo Laredo, Tamaulipas, Mexico, and Laredo, Texas, United States, contiguous cities that straddle the international border. The incidence of recent cases, indicated by immunoglobulin M antibody serosurvey, was higher in Nuevo Laredo, although the vector, Aedes aegypti, was more abundant in Laredo. Environmental factors that affect contact with mosquitoes, such as air-conditioning and human behavior, appear to account for this paradox. We conclude that the low prevalence of dengue in the United States is primarily due to economic, rather than climatic, factors

    Concentração de fluoreto em arroz, feijão e alimentos infantis industrializados

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    OBJETIVO: Determinar a concentração de fluoreto na refeição brasileira típica (arroz e feijão) e em alimentos infantis industrializados e estimar suas contribuições para fluorose dental. MÉTODOS: Os alimentos foram adquiridos de supermercados das cidades de Piracicaba e Campinas, SP, Brasil. Os alimentos infantis industrializados foram comprados em 2001 e o arroz e feijão em 2003, e imediatamente analisados. Foram analisadas três marcas de arroz, três de feijão e 36 amostras de alimentos infantis divididos em cinco grupos: prontos para o consumo; mingaus; alimentos formulados; leites em pó e outros alimentos. No arroz e feijão, foram determinadas as concentrações de fluoreto nas sementes "in natura" e após cozimento com água destilada ou fluoretada (0,7 ppm). Todas as análises de fluoreto foram feitas com eletrodo específico. Considerou-se 0,07 mg/kg/dia como a dose limite de exposição a fluoreto para risco de fluorose. RESULTADOS: A concentração de fluoreto encontrada nos grãos de arroz e feijão foi baixa. Porém, a concentração aumentou 100-200 vezes após cozimento em água fluoretada e mesmo assim, foi menor que a encontrada em alguns alimentos industrializados. Uma refeição com arroz e feijão preparada com água fluoretada seria responsável por 29% da dose limite de ingestão de fluoreto em termos de fluorose aceitável; a contribuição de alguns alimentos industrializados atingiria 45%. CONCLUSÕES: A alimentação típica brasileira, mesmo preparada com água fluoretada, é mais segura em termos de risco de fluorose dental que alguns alimentos infantis industrializados

    Clinical Pattern of Tolvaptan-Associated Liver Injury in Subjects with Autosomal Dominant Polycystic Kidney Disease: Analysis of Clinical Trials Database

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    INTRODUCTION: Subjects with autosomal dominant polycystic kidney disease (ADPKD) who were taking tolvaptan experienced aminotransferase elevations more frequently than those on placebo in the TEMPO 3:4 (Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and its Outcomes) clinical trial. METHODS: An independent, blinded, expert Hepatic Adjudication Committee re-examined data from TEMPO 3:4 and its open-label extension TEMPO 4:4, as well as from long-term (>14 months) non-ADPKD tolvaptan trials, using the 5-point Drug-Induced Liver Injury Network classification. RESULTS: In TEMPO 3:4, 1445 subjects were randomized 2:1 (tolvaptan vs. placebo) and 1441 had post-baseline assessments of hepatic injury. Sixteen patients on tolvaptan and one on placebo had significant aminotransferase elevations judged to be at least probably related to study drug. No association with dose or systemic exposure was found. Two of 957 subjects taking tolvaptan (0.2 %) and zero of 484 taking placebo met the definition of a Hy’s Law case. One additional Hy’s Law case was identified in a TEMPO 4:4 subject who had received placebo in the lead study. The onset of a hepatocellular injury occurred between 3 and 18 months after starting tolvaptan, with gradual resolution over the subsequent 1–4 months. None of the events were associated with liver failure or chronic liver injury/dysfunction. No imbalance in hepatic events was observed between tolvaptan and placebo in lower-dose clinical trials of patients with hyponatremia, heart failure, or cirrhosis. CONCLUSIONS: Although hepatocellular injury following long-term tolvaptan treatment in ADPKD subjects was infrequent and reversible, the potential for serious irreversible injury exists. Regular monitoring of transaminase levels is warranted in this patient population

    Physiological Correlates of Volunteering

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    We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Effect of fatty Amazon fish consumption on lipid metabolism

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    OBJECTIVE: The present study aimed to evaluate the effect of feeding diets enriched with fatty fish from the Amazon basin on lipid metabolism. METHODS: Male Wistar rats were divided into four groups: control group treated with commercial chow; Mapará group was fed diet enriched with Hypophthalmus edentatus; Matrinxã group was fed diet enriched with Brycon spp.; and, Tambaqui group was fed diet enriched with Colossoma macropomum. Rats with approximately 240g±0.60 of body weight were fed ad libitum for 30 days, and then were sacrificed for collection of whole blood and tissues. RESULTS: The groups treated with enriched diets showed a significant reduction in body mass and lipogenesis in the epididymal and retroperitoneal adipose tissues and carcass when compared with the control group. However, lipogenesis in the liver showed an increase in Matrinxã group compared with the others groups. The levels of serum triglycerides in the treated groups with Amazonian fish were significantly lower than those of the control group. Moreover, total cholesterol concentration only decreased in the group Matrinxã. High Density Lipoprotein cholesterol levels increased significantly in the Mapará and Tambaqui compared with control group and Matrinxã group. The insulin and leptin levels increased significantly in all treatment groups. CONCLUSION: This study demonstrated that diets enriched with fatty fish from the Amazon basin changed the lipid metabolism by reducing serum triglycerides and increasing high density lipoprotein-cholesterol in rats fed with diets enriched with Mapará, Matrinxã, and Tambaqui
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