2,027 research outputs found
Reduced dimension modeling of leading edge turbulent interaction noise
A computational aeroacoustics approach is used to model the effects of real airfoil geometry on leading edge turbulent interaction noise for symmetric airfoils at zero angle of attack. For the first time, one-component (transverse), two-component (transverse and streamwise), and three-component (transverse, streamwise, and spanwise) synthesized turbulent disturbances are modeled instead of single frequency transverse gusts, which previous computational studies of leading edge noise have been confined to. The effects of the inclusion of streamwise and spanwise disturbances on the noise are assessed, and it is shown that accurate noise predictions for symmetric airfoils can be made by modeling only the transverse disturbances, which reduces the computational expense of simulations. Additionally, the two-component turbulent synthesis method is used to model the effects of airfoil thickness on the noise for thicknesses ranging from 2% to 12%. By using sufficient airfoil thicknesses to show trends, it is found that airfoil thickness will reduce the noise at high frequency, and that the sound power P will reduce linearly with increasing airfoil thickness
Applying Biomedical Ontologies on Semantic Query Expansion
*1- Introduction*

The interpretation of a question (or information need) depends, among other things, of a series of lexicalsemantic relations that complement and help the cognitive process of answering that information need. Despite this fact, currently used information retrieval mechanisms take few advantages of the semantic interpretation of users’ information needs (usually specified through keywords). In most of the cases, those mechanisms are based on keyword matching, and thus are excessively dependant on the query and document terms.

There are several past results showing that, in general, information retrieval based on domain knowledge decreases the accuracy of keyword based search engines. We believe this approach deserves further discussion and experimentation, looking for more strong evidences that these negative results can really be generalized. Moreover, there are some questions left unanswered by previous work that our experiment is addressing:

(_i_) Using a scientific ontology, with formal construction and maintenance processes, such as the OBO ontologies, would produce better results? 

(_ii_) Are there more efficient query expansion techniques using available domain knowledge?

(_iii_) Is a scientific ontology complete enough to fulfill the information retrieval researchers’ needs, in general?

*2- Semantic Query Expansion*

To try to answer some of these questions, we run a query expansion experiment using the Gene Ontology (GO) as domain knowledge. As the document repository, we used an extraction of 10 years of PubMed publications (from 1994 to 2004), which contains approximately 4.6 Million documents. This dataset is a test collection used by the information retrieval community, called Genomic TREC.

*3- Results*
To evaluate our ontology-based semantic query expansion technique, we measured the effectiveness of the information retrieval mechanism with and without expansion. In a nutshell, the average result showed an increase of 28% on synonyms relations and a small decrease on other relations.

Our results show a lot of consistence with past related work. In fact, if the expansion strategy does not selectively choose when and how to expand, only synonym relations are worth to be used. However, looking further, it is possible to find several opportunities to try other expansion strategies. For example, the problem with query expansion using generalization/specialization relationships is that, if it is always applied, the bad results are more frequent than the good ones. But, if the strategy is to be selective on when to use these relations for expansion, the increasing on accuracy can be outstanding. As shown by our experiment, there was a query with 98% increment on effectiveness. 

*4- Conclusion*
We strongly believe that it is premature to assume that semantics-based query expansion is, in general, a recall-enhancing, precision-degrading technique. Our experiments suggest that by using scientific based ontologies (like OBO ontologies) with formal relations, it is possible to increase both recall and precision. Our group is currently revising this first experiment towards a better semantic query expansion strategy.

*5- Acknowledgements*
This work was partially funded by CAPES and CNPq research grants 311454/2006-2, 306889/2007-2 and 484713/2007-8.

*References*
_Fox E. Lexical relations enhancing effectiveness of information retrieval systems. SIGIR Forum, New York, v.15, n.3, p.5-3._

_Voorhees E. Query expansion using lexicalsemantic relations. In: ACM SIGIR conference on research and development in information retrieval, Proceedings, Dublin:17, p.61–69, 1994
The Cognitive Processes Underlying Affective Decision-Making Predicting Adolescent Smoking Behaviors in a Longitudinal Study
This study investigates the relationship between three different cognitive processes underlying the Iowa Gambling Task (IGT) and adolescent smoking behaviors in a longitudinal study. We conducted a longitudinal study of 181 Chinese adolescents in Chengdu City, China. The participants were followed from 10th to 11th grade. When they were in the 10th grade (Time 1), we tested these adolescents’ decision-making using the IGT and working memory capacity using the Self-ordered Pointing Test (SOPT). Self-report questionnaires were used to assess school academic performance and smoking behaviors. The same questionnaires were completed again at the 1-year follow-up (Time 2). The Expectancy-Valence (EV) Model was applied to distill the IGT performance into three different underlying psychological components: (i) a motivational component which indicates the subjective weight the adolescents assign to gains vs. losses; (ii) a learning-rate component which indicates the sensitivity to recent outcomes vs. past experiences; and (iii) a response component which indicates how consistent the adolescents are between learning and responding. The subjective weight to gains vs. losses at Time 1 significantly predicted current smokers and current smoking levels at Time 2, controlling for demographic variables and baseline smoking behaviors. Therefore, by decomposing the IGT into three different psychological components, we found that the motivational process of weight gain vs. losses may serve as a neuropsychological marker to predict adolescent smoking behaviors in a general youth population
The sensory acceptability of a tilapia (Oreochromis niloticus) mechanically separated meat-based spread.
A carne mecanicamente separada (CMS) é uma alternativa para a diversificação de novos produtos à base de pescado e também se mostra como um destino para os resíduos da indústria de filetagem. A carne mecanicamente separada de tilápia foi utilizada, neste estudo, na formulação de patê, com o objetivo de investigar a aceitabilidade desse produto pelos consumidores. Duas formulações de patê foram preparadas, com diferentes tipos de sais comerciais: sal temperado (A) e sal comum (B). Consumidores (112) avaliaram a aceitação em relação à impressão global, à espalhabilidade, à aparência e ao sabor em escala hedônica de nove pontos. A análise microbiológica da carne mecanicamente separada de tilápia e a composição química da formulação de patê de tilápia também foram determinadas. Quando a aceitação de todos os consumidores foi considerada, a impressão global, a aparência e o sabor foram significativamente (p < 0,05) inferiores para o patê de tilápia com sal comum (B). No entanto, três diferentes grupos de consumidores foram encontrados a partir da aceitabilidade da impressão global do patê de tilápia. O maior segmento também preferiu o patê de tilápia com sal temperado (A), mas ambos tiveram alta aceitabilidade. A CMS de tilápia apresentou qualidade como matéria-prima de acordo com regulamento técnico sobre padrões microbiológicos. O produto final apresentou a seguinte composição química: umidade - 62,17%; cinzas - 2,11%; proteína - 9,75%, e lipídios - 18,81%. Esses resultados podem ser de grande importância para a indústria no desenvolvimento e na comercialização de novos produtos obtidos a partir da carne mecanicamente separada de tilápia
Ferricytochrome c Directly Oxidizes Aminoacetone to Methylglyoxal, a Catabolite Accumulated in Carbonyl Stress
Age-related diseases are associated with increased production of reactive oxygen and carbonyl species such as methylglyoxal. Aminoacetone, a putative threonine catabolite, is reportedly known to undergo metal-catalyzed oxidation to methylglyoxal, NH4+ ion, and H2O2 coupled with (i) permeabilization of rat liver mitochondria, and (ii) apoptosis of insulin-producing cells. Oxidation of aminoacetone to methylglyoxal is now shown to be accelerated by ferricytochrome c, a reaction initiated by one-electron reduction of ferricytochrome c by aminoacetone without amino acid modifications. the participation of O-2(center dot-) and HO center dot radical intermediates is demonstrated by the inhibitory effect of added superoxide dismutase and Electron Paramagnetic Resonance spin-trapping experiments with 5,5'-dimethyl-1-pyrroline-N-oxide. We hypothesize that two consecutive one-electron transfers from aminoacetone (E-0 values = -0.51 and -1.0 V) to ferricytochrome c (E-0 = 0.26 V) may lead to aminoacetone enoyl radical and, subsequently, imine aminoacetone, whose hydrolysis yields methylglyoxal and NH4+ ion. in the presence of oxygen, aminoacetone enoyl and O-2(center dot-) radicals propagate aminoacetone oxidation to methylglyoxal and H2O2. These data endorse the hypothesis that aminoacetone, putatively accumulated in diabetes, may directly reduce ferricyt c yielding methylglyoxal and free radicals, thereby triggering redox imbalance and adverse mitochondrial responses.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)INCT Processos Redox em Biomedicina (Brazil)Univ São Paulo, Dept Bioquim, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim & Biol Mol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilUniv São Paulo, Dept Fis & Informat, São Paulo, BrazilUniv Fed ABC, Ctr Ciencias Nat & Humanas, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim & Biol Mol, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilWeb of Scienc
Lack of beta(2)-adrenoceptors aggravates heart failure-induced skeletal muscle myopathy in mice
Skeletal myopathy is a hallmark of heart failure (HF) and has been associated with a poor prognosis. HF and other chronic degenerative diseases share a common feature of a stressed system: sympathetic hyperactivity. Although beneficial acutely, chronic sympathetic hyperactivity is one of the main triggers of skeletal myopathy in HF. Considering that (2)-adrenoceptors mediate the activity of sympathetic nervous system in skeletal muscle, we presently evaluated the contribution of (2)-adrenoceptors for the morphofunctional alterations in skeletal muscle and also for exercise intolerance induced by HF. Male WT and (2)-adrenoceptor knockout mice on a FVB genetic background (2KO) were submitted to myocardial infarction (MI) or SHAM surgery. Ninety days after MI both WT and 2KO mice presented to cardiac dysfunction and remodelling accompanied by significantly increased norepinephrine and epinephrine plasma levels, exercise intolerance, changes towards more glycolytic fibres and vascular rarefaction in plantaris muscle. However, 2KO MI mice displayed more pronounced exercise intolerance and skeletal myopathy when compared to WT MI mice. Skeletal muscle atrophy of infarcted 2KO mice was paralleled by reduced levels of phosphorylated Akt at Ser 473 while increased levels of proteins related with the ubiquitin--proteasome system, and increased 26S proteasome activity. Taken together, our results suggest that lack of (2)-adrenoceptors worsen and/or anticipate the skeletal myopathy observed in HF.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Escola Educ Fis & Esporte, BR-05508900 São Paulo, BrazilUniv São Paulo, Fac Med, Inst Heart, BR-05508900 São Paulo, BrazilUniv São Paulo, Sch Phys Educ & Sport, BR-14049 Ribeirao Preto, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilFAPESP: 2008/56483-1CNPq: 302201/2011-4FAPESP: 2010/50048-1Web of Scienc
Decision-making, cognitive distortions and alcohol use in adolescent problem and non-problem gamblers: an experimental study
In the psychological literature, many studies have investigated the neuropsychological and behavioral changes that occur developmentally during adolescence. These studies have consistently observed a deficit in the decision-making ability of children and adolescents. This deficit has been ascribed to incomplete brain development. The same deficit has also been observed in adult problem and pathological gamblers. However, to date, no study has examined decision-making in adolescents with and without gambling problems. Furthermore, no study has ever examined associations between problem gambling, decision-making, cognitive distortions and alcohol use in youth. To address these issues, 104 male adolescents participated in this study. They were equally divided in two groups, problem gamblers and non-problem gamblers, based on South Oaks Gambling Screen Revised for Adolescents scores. All participants performed the Iowa Gambling Task and completed the Gambling Related Cognitions Scale and the Alcohol Use Disorders Identification Test. Adolescent problem gamblers displayed impaired decision-making, reported high cognitive distortions, and had more problematic alcohol use compared to non-problem gamblers. Strong correlations between problem gambling, alcohol use, and cognitive distortions were observed. Decision-making correlated with interpretative bias. This study demonstrated that adolescent problem gamblers appear to have the same psychological profile as adult problem gamblers and that gambling involvement can negatively impact on decision-making ability that, in adolescence, is still developing. The correlations between interpretative bias and decision-making suggested that the beliefs in the ability to influence gambling outcomes may facilitate decision-making impairment
Monitoring Cognitive and Emotional Processes Through Pupil and Cardiac Response During Dynamic Versus Logical Task
The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error
Integrative Effect of Carvedilol and Aerobic Exercise Training Therapies on Improving Cardiac Contractility and Remodeling in Heart Failure Mice
The use of b-blockers is mandatory for counteracting heart failure (HF)-induced chronic sympathetic hyperactivity, cardiac dysfunction and remodeling. Importantly, aerobic exercise training, an efficient nonpharmacological therapy to HF, also counteracts sympathetic hyperactivity in HF and improves exercise tolerance and cardiac contractility; the latter associated with changes in cardiac Ca2+ handling. This study was undertaken to test whether combined b-blocker and aerobic exercise training would integrate the beneficial effects of isolated therapies on cardiac structure, contractility and cardiomyocyte Ca2+ handling in a genetic model of sympathetic hyperactivity-induced HF (alpha(2A)/alpha 2C(-)adrenergic receptor knockout mice, KO). We used a cohort of 5-7 mo male wild-type (WT) and congenic mice (KO) with C57Bl6/J genetic background randomly assigned into 5 groups: control (WT), saline-treated KO (KOS), exercise trained KO (KOT), carvedilol-treated KO (KOC) and, combined carvedilol-treated and exercise-trained KO (KOCT). Isolated and combined therapies reduced mortality compared with KOS mice. Both KOT and KOCT groups had increased exercise tolerance, while groups receiving carvedilol had increased left ventricular fractional shortening and reduced cardiac collagen volume fraction compared with KOS group. Cellular data confirmed that cardiomyocytes from KOS mice displayed abnormal Ca2+ handling. KOT group had increased intracellular peak of Ca2+ transient and reduced diastolic Ca2+ decay compared with KOS group, while KOC had increased Ca2+ decay compared with KOS group. Notably, combined therapies re-established cardiomyocyte Ca2+ transient paralleled by increased SERCA2 expression and SERCA2: PLN ratio toward WT levels. Aerobic exercise trained increased the phosphorylation of PLN at Ser16 and Thr17 residues in both KOT and KOCT groups, but carvedilol treatment reduced lipid peroxidation in KOC and KOCT groups compared with KOS group. the present findings provide evidence that the combination of carvedilol and aerobic exercise training therapies lead to a better integrative outcome than carvedilol or exercise training used in isolation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Pesquisa e DesenvolvimentoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Sch Phys Educ & Sport, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilDept Circulat & Med Imaging, Trondheim, NorwayKG Jebsen Ctr Exercise Med, Trondheim, NorwayUniv Fed Minas Gerais, Dept Physiol & Biophys, Belo Horizonte, MG, BrazilUniv São Paulo, Heart Inst InCor, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilFAPESP: FAPESP:2010/50048-1FAPESP: 06/56123-0CNPq: 302201/2011-4Web of Scienc
A pedagogic appraisal of the Priority Heuristic
We have explored how science and mathematics teachers made decisions when confronted with a dilemma in which a fictitious young woman, Deborah, may choose to have an operation that might address a painful spinal condition. We sought to explore the extent to which psychological heuristic models, in particular the Priority Heuristic, might successfully describe the decision-making process of these teachers and how an analysis of the role of personal and emotional factors in shaping the decision-making process might inform pedagogical design. A novel aspect of this study is that the setting in which the decision-making process is examined contrasts sharply with those used in psychological experiments. We found that to some extent, even in this contrasting setting, the Priority Heuristic could describe these teachers' decision-making. Further analysis of the transcripts yielded some insights into limitations on scope as well the richness and complexity in how personal factors were brought to bear. We see these limitations as design opportunities for educational intervention
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