562 research outputs found
Wearing a bike helmet leads to less cognitive control, revealed by lower frontal midline theta power and risk indifference
A recent study claims that participants wearing a bike helmet behave riskier in a computer-based risk task compared to control participants without a bike helmet. We hypothesized that wearing a bike helmet reduces cognitive control over risky behavior. To test our hypothesis, we recorded participants' EEG brain responses while they played a risk game developed in our laboratory. Previously, we found that, in this risk game, anxious participants showed greater levels of cognitive control as revealed by greater frontal midline theta power, which was associated with less risky decisions. Here, we predicted that cognitive control would be reduced in the helmet group, indicated by reduced frontal midline theta power, and that this group would prefer riskier options in the risk game. In line with our hypothesis, we found that participants in the helmet group showed significantly lower frontal midline theta power than participants in the control group, indicating less cognitive control. We did not replicate the finding of generally riskier behavior in the helmet group. Instead, we found that participants chose the riskier option in about half of trials, no matter how risky the other option was. Our results suggest that wearing a bike helmet reduces cognitive control, as revealed by reduced frontal midline theta power, leading to risk indifference when evaluating potential behaviors
What you give is what you get : payment of one randomly selected trial induces risk-aversion and decreases brain responses to monetary feedback
In economic studies, it is standard practice to pay out the reward of only one randomly selected trial (pay-one) instead of the total reward accumulated across trials (pay-all), assuming that both methods are equivalent. We tested this assumption by recording electrophysiological activity to reward feedback from participants engaged in a decision-making task under both a pay-one and a pay-all condition. We show that participants are approximately 12% more risk averse in the pay-one condition than in the pay-all condition. Furthermore, we observed that the electrophysiological response to monetary rewards, the reward positivity, is significantly reduced in the pay-one condition relative to the pay-all condition. The difference of brain responses is associated with the difference in risky behavior across conditions. We concluded that the two payment methods lead to significantly different results and are therefore not equivalent
Control of disinfection by-products and biodegradable organic matter through biological treatment
L'objectif de ce projet, commun à l'Agence Américaine pour la Protection de l'Environnement (USEPA) et l'Université de Cincinnati, est d'optimiser l'usage de la préozonation associée à des procédés biologiques pour le traitement de l'eau de la rivière Ohio en vue de produire une eau biologiquement stable, d'éliminer une partie importante de la demande en chlore, et de réduire le potentiel de formation des sous-produits de la disintection. Ce projet a été conduit à l'échelle pilote et à l'échelle du laboratoire. Pour le traitement biologique, des bioréacteurs, contenant un film biologique sur un sable acclimaté aux eaux de la rivière Ohio, ont été utilisé.Une attention particulière a été portée à l'étude des sous-produits de la disinfection (DBPs) et de leurs précurseurs.Les résultats de l'ozonation ont démontré la formation d'aldéhydes : formaidéhyde, méthyl glyoxal, glyoxal et acétaldéhyde. A l'exception du formaldéhyde, les aldéhydes augmentent avec l'augmentation de la dose d'ozone, puis se stabilisent à un rapport d'ozone/carbone organique total (O3/COT) de 0,7 mg/mg. La formaldéhyde continue à augmenter proportionnellement aux doses d'ozone. Après traitement biologique, la concentration en aldéhydes diminue au dessous de 1 µg/l.L'augmentation de la dose d'ozone augmente le carbone organique assimilable (COA), (COA P17 ou COA-NOX), ainsi que le carbone organique dissous biodégradable (CODE). Le COA atteint un maximum pour une dose O3/COT de 2 mg/mg, alors que le COU continue à augmenter avec l'augmentation de la dose d'ozone jusqu'à une dose O3/COT de 3 mg/mg.La demande en chlore est réduite par les deux traitements, soit l'ozonation soit les procédés biologiques, respectivement de 75 % par l'ozonation et 55 % par les traitements biologiques.Des résultats similaires ont été trouvés en ce qui concerne l'effet des différentes doses d'ozone et des traitements biologiques sur les précurseurs des composés organiques halogénés totaux (TOX), les trihalométhanes (THMs) et les acides acétiques halogénés (HAAs). Les précurseurs sont mesurés par le potentiel de formation (FP), (conditions expérimentales : 12 mg/l de chlore, 7 jours de contact, 25 °C et pH 6,5 - 7,2). A une dose d'O3/COD de 0,4 mg/mg, les TOXFP, les THMFP et les HAAFP sont diminué de 28 %, 23 %, et 33 % respectivement. L'abattement des TOXFP et des THMFP continue légèrement avec une augmentation de la dose d'ozone, alors que les HAAFP sont diminués de façon plus marquée avec une dose d'O3/COD de 0,87 mglmg. Avec le traitement biologique et même sans préozonation, les TOXFP, les THMFP et les HAAFP diminuent de 39 %, 38 %, et 73 % respectivement. Avec le couplage de l'ozonation et le traitement biologique, les TOXFP et les THMFP sont diminués de 30 à 50 %. Les HAAFP se stabilisent entre 30 et 40 µg/l pour toutes les doses étudiées.Le potentiel de formation de chloropicrine augmente par l'ozonation mais est réduit de suite par le traitement biologique, jusqu'à moins de 0,2 µg/l.Donc, pour éliminer les sous-produits de la disinfection, la concentration optimale d'ozone pour l'eau de la rivière Ohio serait entre 0,6 à 1,0 mg/mg (O3/COT).En conclusion, l'ozonation diminue la demande en chlore ainsi que les précurseurs des composés organiques halogénés (TOX, THM et HAA). Par contre, l'ozonation produit des autres sous-produits comme les aldéhydes et le chloropicrine et augmente le COA et le COD biodégradable, qui sert par la suite de substrat aux microorganismes. Les procédés biologiques sont efficaces pour diminuer les sous-produits d'oxydation, la demande en chlore et les précurseurs des composés organiques halogénés (TOX, THM et HAA).Cet abattement permettra l'application de moins de chlore pour maintenir un résiduel dans le réseau et permettra aux usines d'atteindre des normes plus sévères que celles qui sont en effet maintenant.The optimal use of ozonation as a pretreatment process prior to biological treatment of Ohio River water was investigated at both the bench (batch) and pilot-plant (continuous flow) scale. The study focused on disinfection by-products (DBPs) and DBP precursor compounds and on the production of biologically stable water. Biotreatment was achieved using a bench-scale fixed-film reactor with sand acclimated to the raw Ohio River water.Ozonation was found to create a number of aldehydes, in particular formaldehyde, methyl glyoxal, glyoxal and acetaldehyde. With the exception of formaldehyde, a plateau in the aldehyde yield occurred at an ozone to total organic carbon (03/TOC) ratio of 0,7 mg/mg, while formaldehyde increased with increasing ozone dose. After biotreatment, the concentration of aldehydes were below 1 µg/1. Increasing ozone doses were also found to increase the assimilable organic carbon (AOC), by both NOX and P17 procedures, and the biodegradable dissolved organic carton (BDOC). The AOC values showed a maximum at about an 03/TOC ratio of 2 mg/mg, white the BDOC continued to increase with the highest ozone dose : an 03/TOC ratio of 2,8 mg/mg.Both ozonation and biotreatment were fond to decrease the chlorine demand by up to 75 % for ozonation and 55 % for biotreatment.Similar trends were found for the impact of ozonation and biotreatment on the precursor compounds for total organic halogen (TOX), total trihalomethanes (TTHMs) and total haloacetic acids (THAAs), as measured by the formation potential (FP) test : 12 mg/l chlorine, 7 days, 25 °C, 6.5-7.2 pH. An ozone dose of 0.4 03/DOC (mg/mg) decreased the TOXFP, TTHMFP and THAAFP by 28 %, 23 % and 33 %, respectively. Further increases in ozone only marginally increased the amount of the TOXFP and TTHMFP removed, white a maximum removal of 53 % of the THAAFP occurred at 03/DOC ratio of 0.87 mg/mg. Biotreatment of the nonozonated samples yielded 39 %, 38 % and 73 % removal of the TOXFP, TTHMFP and THAAFP, respectively. Biotreatment of the ozonated sample yielded a 30 to 50 % reduction in TOXFP and TTHMFP, while a constant level of 30 to 40 µg/l of THAAFP was achieved. Chloropicrin formation potential increased with ozone dose, but subsequent biotreatment reduced it to below 0.2 µg/l.Ozonation was Pound to oxidize chorine demand and the precursors for TOX, THM and HAAs. However, it created chloropicrin precursors, aldehydes and other biodegradable organic matter. Biotreatment was found to further reduce the chlorine demand, the precursors for TOX, THMs and HAAs and reduce the ozone created disinfection by-products
Robustness and Enhancement of Neural Synchronization by Activity-Dependent Coupling
We study the synchronization of two model neurons coupled through a synapse
having an activity-dependent strength. Our synapse follows the rules of
Spike-Timing Dependent Plasticity (STDP). We show that this plasticity of the
coupling between neurons produces enlarged frequency locking zones and results
in synchronization that is more rapid and much more robust against noise than
classical synchronization arising from connections with constant strength. We
also present a simple discrete map model that demonstrates the generality of
the phenomenon.Comment: 4 pages, accepted for publication in PR
Aberrant network connectivity during error processing in patients with schizophrenia
BACKGROUND: Neuroimaging methods have pointed to deficits in the interaction of large-scale brain networks in patients with schizophrenia. Abnormal connectivity of the right anterior insula (AI), a central hub of the salience network, is frequently reported and may underlie patients’ deficits in adaptive salience processing and cognitive control. While most previous studies used resting state approaches, we examined right AI interactions in a task-based fMRI study. METHODS: Patients with schizophrenia and healthy controls performed an adaptive version of the Eriksen Flanker task that was specifically designed to ensure a comparable number of errors between groups. RESULTS: We included 27 patients with schizophrenia and 27 healthy controls in our study. The between-groups comparison replicated the classic finding of reduced activation in the midcingulate cortex (MCC) in patients with schizophrenia during the commission of errors while controlling for confounding factors, such as task performance and error frequency, which have been neglected in many previous studies. Subsequent psychophysiological interaction analysis revealed aberrant functional connectivity (FC) between the right AI and regions in the inferior frontal gyrus and temporoparietal junction. Additionally, FC between the MCC and the dorsolateral prefrontal cortex was reduced. LIMITATIONS: As we examined a sample of medicated patients, effects of antipsychotic medication may have influenced our results. CONCLUSION: Overall, it appears that schizophrenia is associated with impairment of networks associated with detection of errors, refocusing of attention, superordinate guiding of cognitive control and their respective coordination
Mitigating the negative impacts of tall wind turbines on bats: Vertical activity profiles and relationships to wind speed.
Wind turbines represent a source of hazard for bats, especially through collision with rotor blades. With increasing technical development, tall turbines (rotor-swept zone 50-150 m above ground level) are becoming widespread, yet we lack quantitative information about species active at these heights, which impedes proposing targeted mitigation recommendations for bat-friendly turbine operation. We investigated vertical activity profiles of a bat assemblage, and their relationships to wind speed, within a major valley of the European Alps where tall wind turbines are being deployed. To monitor bat activity we installed automatic recorders at sequentially increasing heights from ground level up to 65 m, with the goal to determine species-specific vertical activity profiles and to link them to wind speed. Bat call sequences were analysed with an automatic algorithm, paying particular attention to mouse-eared bats (Myotis myotis and Myotis blythii) and the European free-tailed bat (Tadarida teniotis), three locally rare species. The most often recorded bats were the Common pipistrelle (Pipistrellus pipistrellus) and Savi's pipistrelle (Hypsugo savii). Mouse-eared bats were rarely recorded, and mostly just above ground, appearing out of risk of collision. T. teniotis had a more evenly distributed vertical activity profile, often being active at rotor level, but its activity at that height ceased above 5 ms-1 wind speed. Overall bat activity in the rotor-swept zone declined with increasing wind speed, dropping below 5% above 5.4 ms-1. Collision risk could be drastically reduced if nocturnal operation of tall wind turbines would be restricted to wind speeds above 5 ms-1. Such measure should be implemented year-round because T. teniotis remains active in winter. This operational restriction is likely to cause only small energy production losses at these tall wind turbines, although further analyses are needed to assess these losses precisely
Institutional maintenance of macroeconomic equilibrium and well-being
Goodwill component changes the pricing mechanism and gives the production of knowledge marketable character, complementing its with cognitive component. The paper substantiates the need to institute a regulated competitive market order as the search strategy of social sustainable balance consolidated on the basis of the reproduction cognitive capital process
Opioid receptor activation triggering downregulation of cAMP improves effectiveness of anti-cancer drugs in treatment of glioblastoma
Glioblastoma are the most frequent and malignant human brain tumors, having a very poor prognosis. The enhanced radio- and chemoresistance of glioblastoma and the glioblastoma stem cells might be the main reason why conventional therapies fail. The second messenger cyclic AMP (cAMP) controls cell proliferation, differentiation, and apoptosis. Downregulation of cAMP sensitizes tumor cells for anti-cancer treatment. Opioid receptor agonists triggering opioid receptors can activate inhibitory Gi proteins, which, in turn, block adenylyl cyclase activity reducing cAMP. In this study, we show that downregulation of cAMP by opioid receptor activation improves the effectiveness of anti-cancer drugs in treatment of glioblastoma. The µ-opioid receptor agonist D,L-methadone sensitizes glioblastoma as well as the untreatable glioblastoma stem cells for doxorubicin-induced apoptosis and activation of apoptosis pathways by reversing deficient caspase activation and deficient downregulation of XIAP and Bcl-xL, playing critical roles in glioblastomas' resistance. Blocking opioid receptors using the opioid receptor antagonist naloxone or increasing intracellular cAMP by 3-isobutyl-1-methylxanthine (IBMX) strongly reduced opioid receptor agonist-induced sensitization for doxorubicin. In addition, the opioid receptor agonist D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux, whereas doxorubicin increased opioid receptor expression in glioblastomas. Furthermore, opioid receptor activation using D,L-methadone inhibited tumor growth significantly in vivo. Our findings suggest that opioid receptor activation triggering downregulation of cAMP is a promising strategy to inhibit tumor growth and to improve the effectiveness of anti-cancer drugs in treatment of glioblastoma and in killing glioblastoma stem cells
GABA-enhanced collective behavior in neuronal axons underlies persistent gamma-frequency oscillations
Gamma (30–80 Hz) oscillations occur in mammalian electroencephalogram in a manner that indicates cognitive relevance. In vitro models of gamma oscillations demonstrate two forms of oscillation: one occurring transiently and driven by discrete afferent input and the second occurring persistently in response to activation of excitatory metabotropic receptors. The mechanism underlying persistent gamma oscillations has been suggested to involve gap-junctional communication between axons of principal neurons, but the precise relationship between this neuronal activity and the gamma oscillation has remained elusive. Here we demonstrate that gamma oscillations coexist with high-frequency oscillations (>90 Hz). High-frequency oscillations can be generated in the axonal plexus even when it is physically isolated from pyramidal cell bodies. They were enhanced in networks by nonsomatic -aminobutyric acid type A (GABAA) receptor activation, were modulated by perisomatic GABAA receptor-mediated synaptic input to principal cells, and provided the phasic input to interneurons required to generate persistent gamma-frequency oscillations. The data suggest that high-frequency oscillations occurred as a consequence of random activity within the axonal plexus. Interneurons provide a mechanism by which this random activity is both amplified and organized into a coherent network rhythm
Анализ и разработка способов повышения эффективности работы Томской ГРЭС-2 в летний период
Одно из главных направлений повышения эффективности топливоиспользования на ТЭС – внутристанционная оптимизация режимов паротурбинных установок. Оптимизация режимов абсолютно эффективна, так как в этом случае достигается значительная экономия топлива без дополнительных капитальных вложений.
В данной работе предполагается повышение эффективности Томской ГРЭС-2 в летний период, за счёт оптимизации режимов работы и снятия ограничений установленной мощности при увеличении объёмов отпускаемой тепловой энергии внешним потребителям.One of the main directions of improving the efficiency of fuel use at TPP is the internal optimization of the modes of steam turbine plants. Optimization of modes is absolutely effective, since in this case significant fuel savings are achieved without additional capital investments.
In this work, it is planned to increase the efficiency of the Tomsk ГРЭС-2 in the summer, due to the optimization of operating modes and the removal of restrictions on the installed power with an increase in the volume of thermal energy available to external consumers
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