2,089 research outputs found
Control of entropy in neural models of environmental state
Humans and animals construct internal models of their environment in order to select
appropriate courses of action. The representation of uncertainty about the current state of the
environment is a key feature of these models that controls the rate of learning as well as directly
affecting choice behaviour. To maintain flexibility, given that uncertainty naturally decreases over
time, most theoretical inference models include a dedicated mechanism to drive up model
uncertainty. Here we probe the long-standing hypothesis that noradrenaline is involved in
determining the uncertainty, or entropy, and thus flexibility, of neural models. Pupil diameter,
which indexes neuromodulatory state including noradrenaline release, predicted increases (but not
decreases) in entropy in a neural state model encoded in human medial orbitofrontal cortex, as
measured using multivariate functional MRI. Activity in anterior cingulate cortex predicted pupil
diameter. These results provide evidence for top-down, neuromodulatory control of entropy in
neural state models
Diversity assessment of Aphididae and their natural enemies in banana culture near border plants
Une Ă©valuation des populations de pucerons et de leurs ennemis naturels sous culture de bananier plantain bordĂ©e de plants de tomate et de piment a Ă©tĂ© rĂ©alisĂ©e de mars Ă octobre 2012 dans la rĂ©gion de Bengamisa, en RD Congo. Des diffĂ©rences significatives sur la diversitĂ© et lâabondance des populations aphidiennes et aphidiphages ont Ă©tĂ© observĂ©es entre les espĂšces vĂ©gĂ©tales hĂŽtes expĂ©rimentĂ©es Ă P<0,05. Les familles principales (Aphididae, Aphidiidae et Coccinellidae) ont Ă©tĂ© identifiĂ©es; dont la famille des Coccinellidae a Ă©tĂ© la plus importante en termes dâespĂšces prĂ©datrices regroupant 9 espĂšces aphidiphages, soit 23 %. De cette Ă©tude, la tomate attire les populations de pucerons et dâinsectes aphidiphages les plus diversifiĂ©s (3 espĂšces de pucerons et 9 espĂšces dâinsectes auxiliaires). Le bananier (1 seule espĂšce de pucerons et 7 espĂšces dâinsectes auxiliaires) et le piment (3 espĂšces de pucerons et 7 espĂšces dâinsectes auxiliaires), en attirent moins. Ces rĂ©sultats suggĂšrent une attraction spĂ©cifique entre auxiliaires et plantes due Ă la reconnaissance des molĂ©cules spĂ©cifiques Ă©mises par les plantes. La tendance Ă une distribution prĂ©fĂ©rentielle dâinsectes aux plantes hĂŽtes sâest conservĂ©e pendant les deux saisons, ce qui traduit une infĂ©odation diffĂ©rentielle dâespĂšces aux plantes et une spĂ©cialisation dans lâalimentation dâinsectes.
Mots-clés : lutte biologique, Aphididae, plante marginale, insecte auxiliaire.
An assessment of aphid populations and their natural enemies in a banana field bordered by tomato and pepper plants was conducted from March to October 2012 in the region of Bengamisa, DR Congo. Significant differences in the diversity and the abundance of aphids and aphidophagous populations have been observed between the host plants tested at P<0.05. Three main families (Aphididae, Aphidiidae and Coccinellidae) have been identified in which the Coccinellidae family was the most important in terms of predator species. Out of three host plants tested, tomato attracts the most diversified aphid and aphidophagous insect populations (3 Aphididae species and 9 aphidophagous species). Banana (1 Aphididae species and 7 aphidophagous species) and pepper (3 Aphididae species and 7 aphidophagous species) were less attractive. The results suggest a specific attraction between predators or parasitoids and plants due to the recognition of specific molecules emitted by plants. The tendency to a preferential distribution of insects in relation to host plants has been preserved in both seasons, indicating a differential species allegiance to plants and food specialization in insects.
Keywords: biological control, Aphididae, marginal plant, auxiliary insect
Integrated management of Pentalonia nigronervosa aphid by the push-pull strategy in Bengamisa region, DR Congo
De cette Ă©tude, il a Ă©tĂ© question de tester lâhypothĂšse selon laquelle la stratĂ©gie push-pull rendrait disponible au sein ou Ă proximitĂ© des cultures Ă protĂ©ger, des ressources qui contribuent Ă leur efficacitĂ© telles que des refuges physiques, des hĂŽtes alternatifs, des sources de nourriture ou des signaux attractifs. De ce fait, les rĂ©sultats de lâĂ©tude montrent que la tomate sâest rĂ©vĂ©lĂ©e meilleure plante attractive des aphidiphages en relation avec la culture de bananier dans la rĂ©gion de Bengamisa par son effet Bottom-Up, renforcĂ© par lâeffet Top Down et par lâeffet de confusion lors des relations push-pull. Enfin, la lutte biologique par conservation peut ĂȘtre considĂ©rĂ©e comme une meilleure stratĂ©gie de lutte contre P. nigronervosa Ă Bengamisa en RĂ©publique DĂ©mocratique du Congo.
Mots clés : Lutte biologique, Push-pull, Pentalonia nigronervosa CoquerelThis study was set up to test the hypothesis according to which the push-pull strategy would make available with in or near crops to be protected, of resources that contribute to their effectiveness such as physical shelters, alternative hosts, food sources or attractive signals. Therefore, the results of the study show that tomato was the best attractive plant of aphidiphagous in relation with the banana in the Bengamisa region by its Bottom Up effect enhanced by the Top Down effect and the confusing effect during the push-pull relationships. Finally, the biological control by conservation might be used as the best strategy control against P. nigronervosa in Bengamisa region in the Democratic Republic of the Congo.
Keywords: Biological control, Push-pull, Pentalonia nigronerosa Coquerel
Integrated management of Pentalonia nigronervosa aphid by the push-pull strategy in Bengamisa region, DR Congo
This study was discussed to test the hypothesis according to which the push-pull strategy would make available within or near crop protection, resources that contribute to their effectiveness such as physical shelters, alternative hosts, food sources or attractive signal. Therefore, the results of the study show that the tomato has been pointed to be the best attractive plant of aphidiphagous in relation with the banana in the Bengamisa region by its Botton Up effect enhanced by the Top Down effect and the confusing effect during the push- pull relationships. Finally, the biological control by conservation migth is used as the best strategy control against P. nigronervosa in Bengamisa region in the Democratic Republic of the Congo
Diversity assessment of Aphididae and their natural enemies in banana culture near border plants
An assessment of aphid populations and their natural enemies in a banana field bordered by tomato and pepper plants was conducted from March to October 2012 in the region of Bengamisa, D.R.Congo. Significant differences in the diversity and the abundance of aphids and aphidophagous populations have been observed between the host plants tested at P<0.05. Three main families (Aphididae, Aphidiidae and Coccinellidae) have been identified, in which the Coccinellidae family was the most important in terms of predator species. Out of three host plants tested, tomato attracts the most diversified aphid and aphidophagous insect populations (3 Aphididae species and 9 aphidophagous species). Banana (1 Aphididae species and 7 aphidophagous species) and pepper (3 Aphididae species and 7 aphidophagous species) were less attractive. The results suggest a specific attraction between predators or parasitoids and plants due to the recognition of specific molecules emitted by plants. The tendency to a preferential distribution of insects in relation to host plants has been preserved in both seasons, indicating a differential species allegiance to plants and food specialization in insects
Invasive fungal disease in PICU: epidemiology and risk factors
Candida and Aspergillus spp. are the most common agents responsible for invasive fungal infections in children. They are associated with a high mortality and morbidity rate as well as high health care costs. An important increase in their incidence has been observed during the past two decades. In infants and children, invasive candidiasis is five times more frequent than invasive aspergillosis. Candida sp. represents the third most common agent found in healthcare-associated bloodstream infections in children. Invasive aspergillosis is more often associated with hematological malignancies and solid tumors. Recommendations concerning prophylactic treatment for invasive aspergillosis have been recently published by the Infectious Diseases Society of America. Candida albicans is the main Candida sp. associated with invasive candidiasis in children, even if a strong trend toward the emergence of Candida non-albicans has been observed. The epidemiology and the risk factors for invasive fungal infections are quite different if considering previously healthy children hospitalized in the pediatric intensive care unit, or children with a malignancy or a severe hematological disease (leukemia). In children, the mortality rate for invasive aspergillosis is 2.5 to 3.5 higher than for invasive candidiasis (respectively 70% vs. 20% and 30%)
Pre-Adolescent Cardio-Metabolic Associations and Correlates: PACMAC methodology and study protocol
Introduction: Although cardiovascular disease is typically associated with middle or old age, the atherosclerotic process often initiates early in childhood. The process of atherosclerosis appears to be occurring at an increasing rate, even in pre-adolescents, and has been linked to the childhood obesity epidemic. This study will investigate the relationships between obesity, lifestyle behaviours and cardiometabolic health in pre-pubescent children aged 8â10 years, and investigates whether there are differences in the correlates of cardiometabolic health between MÄori and Caucasian children. Details of the methodological aspects of recruitment, inclusion/exclusion criteria, assessments, statistical analyses, dissemination of findings and anticipated impact are described. Methods and analysis Phase 1: a cross-sectional study design will be used to investigate relationships between obesity, lifestyle behaviours (nutrition, physical activity/fitness, sleep behaviour, psychosocial influences) and cardiometabolic health in a sample of 400 pre-pubescent (8â10 years old) children. Phase 2: in a subgroup (50 Caucasian, 50 MÄori children), additional measurements of cardiometabolic health and lifestyle behaviours will be obtained to provide objective and detailed data. General linear models and logistic regression will be used to investigate the strongest correlate of (1) fatness; (2) physical activity; (3) nutritional behaviours and (4) cardiometabolic health. Ethics and dissemination Ethical approval will be obtained from the New Zealand Health and Disabilities Ethics Committee. The findings from this study will elucidate targets for decreasing obesity and improving cardiometabolic health among preadolescent children in New Zealand. The aim is to ensure an immediate impact by disseminating these findings in an applicable manner via popular media and traditional academic forums. Most importantly, results from the study will be disseminated to participating schools and relevant MÄori health entities
Circulating Biomarkers of Fibrosis Formation in Patients with Arrhythmogenic Cardiomyopathy
Arrhythmogenic cardiomyopathy (ACM) is a progressive inheritable disease which is characterized by a gradual fibro-(fatty) replacement of the myocardium. Visualization of diffuse and patchy fibrosis patterns is challenging using clinically applied cardiac imaging modalities (e.g., late gadolinium enhancement, LGE). During collagen synthesis and breakdown, carboxy-peptides are released into the bloodstream, specifically procollagen type-I carboxy-terminal propeptides (PICP) and collagen type-I carboxy-terminal telopeptides (ICTP). We collected the serum and EDTA blood samples and clinical data of 45 ACM patients (age 50.11 ± 15.53 years, 44% female), divided into 35 diagnosed ACM patients with a 2010 ARVC Task Force Criteria score (TFC) ℠4, and 10 preclinical variant carriers with a TFC < 4. PICP levels were measured using an enzyme-linked immune sorbent assay and ICTP levels with a radio immunoassay. Increased PICP/ICTP ratios suggest a higher collagen deposition. We found significantly higher PICP and PICP/ICTP levels in diagnosed patients compared to preclinical variant carriers (p < 0.036 and p < 0.027). A moderate negative correlation existed between right ventricular ejection fractions (RVEF) and the PICP/ICTP ratio (r = -0.46, p = 0.06). In addition, significant correlations with left ventricular function (LVEF r = -0.53, p = 0.03 and end-systolic volume r = 0.63, p = 0.02) were found. These findings indicate impaired contractile performance due to pro-fibrotic remodeling. Follow-up studies including a larger number of patients should be performed to substantiate our findings and the validity of those levels as potential promising biomarkers in ACM
Multilevel Deconstruction of the In Vivo Behavior of Looped DNA-Protein Complexes
Protein-DNA complexes with loops play a fundamental role in a wide variety of
cellular processes, ranging from the regulation of DNA transcription to
telomere maintenance. As ubiquitous as they are, their precise in vivo
properties and their integration into the cellular function still remain
largely unexplored. Here, we present a multilevel approach that efficiently
connects in both directions molecular properties with cell physiology and use
it to characterize the molecular properties of the looped DNA-lac repressor
complex while functioning in vivo. The properties we uncover include the
presence of two representative conformations of the complex, the stabilization
of one conformation by DNA architectural proteins, and precise values of the
underlying twisting elastic constants and bending free energies. Incorporation
of all this molecular information into gene-regulation models reveals an
unprecedented versatility of looped DNA-protein complexes at shaping the
properties of gene expression.Comment: Open Access article available at
http://www.plosone.org/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.000035
Developments in Structuring of Reformed Theology:The Synopsis Purioris Theologiae (1625) as Example
The Synopsis Purioris Theologiae (1625), an influential handbook of Reformeddogmatics, began as a cycle of disputations. A comparison of it with the cyclesthat were held previously in Leiden reveals some shifts in the structure of Reformeddogmatics. After introducing the Synopsis, this paper highlights thefunction of prolegomena, the place of predestination, and the relationship betweenthe magistrate and eschatology. It concludes that the choices made in theSynopsis illustrate tensions in Reformed theology. After the conflict with theRemonstrants it became urgent to carefully define the character of theology inthe prolegomena, to relate predestination to the person and work of Christ, andto connect the task of the magistrate to the doctrine of the church
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