125 research outputs found

    Education for Democracy: A co-constructivist perspective

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    En el presente artículo describimos el papel que la educación ha de desempeñar en el proceso de mejora de la calidad de vida en el mundo moderno. El enfoque específico de este artículo enfatiza el papel que la educación debe desempeñar para promover la evolución de las formas de vida democráticas como un medio para mejorar la calidad de la vida tanto personal como colectiva e institucional. La calidad de vida, al menos en lo concerniente a la conducta orientada a fines, supone elegir los valores y alcanzar con éxito los objetivos de la vida. Esto último, está relacionado con la utilización del pensamiento y la discusión crítica para realizar elecciones vitales de tipo individual y colectivo. Lo cual, a su vez, tiene que ver con la institucionalización del ideal democrático. En este sentido, el enfoque principal de nuestro trabajo aplicado trata de promover la evolución de las formas de vida democráticas como un medio para mejorar la calidad de vida en los niveles personal, interpersonal e institucional

    A mozgató működésekért felelős gerincvelői neuronhálózatok morfológiai, fiziológiai vizsgálata és számítógépes szimulációja = Morphological, physiological investigations and computer simulation of spinal neuronal network involved in locomotion.

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    1. Fiziológiai kísérletekben jelentős különbségeket találtak propriospinalis axon - motoneuron (MN) kapcsolatokban a MN-ból elvezetett EPSP amplitúdójában a béka gerincvelőben. Modellkísérletekkel bizonyítottuk, hogy a kapcsolatok között mért eltéréseket több tényező magyarázhatja: a szinapszisok elhelyezkedése, a dendrit kitüremkedések, nem-lineáris PSP szummáció illetve a PSP-ok szómára érkezéséhez szükséges késési idők eltérései. 2. A Xenopus embrió úszómozgásáért felelős központi ritmusgeneráló hálózatában azt vizsgáltuk, hogyan vezethet egy rövid inger hosszú ideig tartó úszó mozgáshoz. Az utóagy-gerincvelő határának populációs modelljében azt találtuk, hogy az utóagyi neuronok közötti reciprok serkentő kapcsolatok felelősek lehetnek az említett jelenségért. Elképzelésünket a kísérletes eredmények megerősítik. 3. Patkány gerincvelőben vizsgáltuk a cink kolokalizációját gátló aminosavakkal. Eredményeink azt mutatták, hogy a gerincvelőben a cink tartalmú terminálisok elsősorban gátló karakterűek, amelyekben a GABA és glicin is megtalálható. 4. Újszülött patkány gerincvelőben elemeztük a commissuralis interneuronok (CIN) neurokémiai sajátságait és szinaptikus kapcsolatait. A jelölt CIN terminálisok több mint fele tartalmazott gátló aminosavat, míg a glutamátot tartalmazó terminálisok aránya 27% volt. A jelölt CIN terminálisok közvetlen kapcsolatot képeztek az ellenoldali motoneuronokkal és CIN-okkal. | 1. We investigated the postsynaptic factors that may contribute the high variability of synaptic efficacy in monosynaptically connected propriospinal axon-motoneuron pairs in the spinal cord of frog. We proved that differences in location of these synapses, dendritic protrusions, non-linear summation of PSPs, sizes of time windows for effective temporal summation and differences in delays of arrivals of PSPs to soma are all factors that may differentiate between high and low efficacy single fiber propriospinal connections found experimentally. 2. The central pattern generator for swimming in the Xenopus tadpole was investigated to find out how a brief stimulus can lead to prolonged swimming. By using large-scale population model of the hindbrain-spinal cord junction we found that reciprocal excitatory connections among hindbrain neurons may be responsible for this phenomenon. Our proposal has strong experimental support. 3. Colocalization of zinc with inhibitory neurotrasmitters was investigated in the rat spinal cord. 70% of zinc-containing terminals showed immunoreactivity for GABA and glycine. 4. In neonatal rats we investigated the axonal projection and neurotransmitter properties of spinal commissural interneurons (CIN). About half of the labelled CIN terminals contained GABA or glycine and one third proved to be excitatory. Many of CIN terminals made close appositions with motor neurons and also with CINs on the opposite side of the spinal cord

    Blood Magnesium, and the Interaction with Calcium, on the Risk of High-Grade Prostate Cancer

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    Ionized calcium (Ca) and magnesium (Mg) compete as essential messengers to regulate cell proliferation and inflammation. We hypothesized that inadequate Mg levels, perhaps relative to Ca levels (e.g. a high Ca/Mg ratio) are associated with greater prostate cancer risk.In this biomarker sub-study of the Nashville Men's Health Study (NMHS), we included 494 NMHS participants, consisting of 98 high-grade (Gleason≥7) and 100 low-grade cancer cases, 133 prostate intraepithelial neoplasia (PIN) cases, and 163 controls without cancer or PIN at biopsy. Linear and logistic regression were used to determine associations between blood Ca, Mg, and the Ca/Mg ratio across controls and case groups while adjusting for potential confounding factors.Serum Mg levels were significantly lower, while the Ca/Mg ratio was significantly higher, among high-grade cases vs. controls (p = 0.04, p = 0.01, respectively). Elevated Mg was significantly associated with a lower risk of high-grade prostate cancer (OR = 0.26 (0.09, 0.85)). An elevated Ca/Mg ratio was also associated with an increased risk of high-grade prostate cancer (OR = 2.81 (1.24, 6.36) adjusted for serum Ca and Mg). In contrast, blood Ca levels were not significantly associated with prostate cancer or PIN.Mg, Ca, or Ca/Mg levels were not associated with low-grade cancer, PIN, PSA levels, prostate volume, or BPH treatment.Low blood Mg levels and a high Ca/Mg ratio were significantly associated with high-grade prostate cancer. These findings suggest Mg affects prostate cancer risk perhaps through interacting with Ca

    Longitudinal neuronal organization and coordination in a simple vertebrate: a continuous, semi-quantitative computer model of the central pattern generator for swimming in young frog tadpoles

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    When frog tadpoles hatch their swimming requires co-ordinated contractions of trunk muscles, driven by motoneurons and controlled by a Central Pattern Generator (CPG). To study this co-ordination we used a 3.5 mm long population model of the young tadpole CPG with continuous distributions of neurons and axon lengths as estimated anatomically. We found that: (1) alternating swimming-type activity fails to self-sustain unless some excitatory interneurons have ascending axons, (2) a rostro-caudal (R-C) gradient in the distribution of excitatory premotor interneurons with short axons is required to obtain the R-C gradient in excitation and resulting progression of motoneuron firing necessary for forward swimming, (3) R-C delays in motoneuron firing decrease if excitatory motoneuron to premotor interneuron synapses are present, (4) these feedback connections and the electrical synapses between motoneurons synchronise motoneuron discharges locally, (5) the above findings are independent of the detailed membrane properties of neurons

    Systems approaches to innovation in crop protection. A systematic literature review

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    The objective of this paper is to explore the extent to which systems approaches to innovation are reflected in the crop protection literature and how such approaches are used. A systematic literature review is conducted to study the relation between crop protection and systems approaches to innovation in 107 publications. The analysis of the crop protection literature demonstrates that only a small fraction is systems-oriented as compared to the bulk of publications with a technology-oriented approach. The analysis of agricultural innovations systems literature shows that, although crop protection is addressed, the potential of this systems approach remains largely unexplored for crop protection innovation. A large share of the publications included in this review focus on cropping or farming ‘systems’ while ‘innovation’ often equals the development, transfer, adoption and diffusion of crop protection technologies at farm level. There is relatively little attention for the institutional and political dimensions of crop protection and the interactions between farm, regional and national levels in crop protection systems. The traditional division of roles and responsibilities of researchers as innovators, extension personnel as disseminators, and farmers as end-users, is challenged only to a limited extent. The majority of publications discusses ways to optimise existing features of crop protection systems, without exploring more structural transformations that may be required to enhance the resilience of crop protection systems

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Causal effect of plasminogen activator inhibitor type 1 on coronary heart disease

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    Background--Plasminogen activator inhibitor type 1 (PAI-1) plays an essential role in the fibrinolysis system and thrombosis. Population studies have reported that blood PAI-1 levels are associated with increased risk of coronary heart disease (CHD). However, it is unclear whether the association reflects a causal influence of PAI-1 on CHD risk. Methods and Results--To evaluate the association between PAI-1 and CHD, we applied a 3-step strategy. First, we investigated the observational association between PAI-1 and CHD incidence using a systematic review based on a literature search for PAI-1 and CHD studies. Second, we explored the causal association between PAI-1 and CHD using a Mendelian randomization approach using summary statistics from large genome-wide association studies. Finally, we explored the causal effect of PAI-1 on cardiovascular risk factors including metabolic and subclinical atherosclerosis measures. In the systematic meta-analysis, the highest quantile of blood PAI-1 level was associated with higher CHD risk comparing with the lowest quantile (odds ratio=2.17; 95% CI: 1.53, 3.07) in an age- and sex-adjusted model. The effect size was reduced in studies using a multivariable-adjusted model (odds ratio=1.46; 95% CI: 1.13, 1.88). The Mendelian randomization analyses suggested a causal effect of increased PAI-1 level on CHD risk (odds ratio=1.22 per unit increase of log-transformed PAI-1; 95% CI: 1.01, 1.47). In addition, we also detected a causal effect of PAI-1 on elevating blood glucose and high-density lipoprotein cholesterol. Conclusions--Our study indicates a causal effect of elevated PAI-1 level on CHD risk, which may be mediated by glucose dysfunction
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