bluuebunny/crossref_metadata_2025 huggingface dataset:
A Gestão Ambiental Como Fonte de Vantagem Competitiva Sustentável: Contribuições da Visão Baseada em Recursos e da Teoria Institucional
Authors: Finazzi Santos Patrick Michel , Porto Rafael Barreiros
Published: April 2013

Este artigo de natureza teórica almeja discutir o papel da gestão ambiental na geração de vantagem competitiva a uma firma. Seu objetivo é verificar em que condições a gestão ambiental pode contribuir com a vantagem competitiva sustentável, segundo os arcabouços teóricos da Visão Baseada em Recursos (VBR) e da Teoria Institucional (TI). Para tal, fundamentado no trabalho de Hart (1995), foram sugeridas três estratégias ambientais (Produtividade dos Recursos, Negócios Sustentáveis e Reputação Corporativa) por meio das quais se deu o diálogo entre a gestão ambiental, a VBR e a TI. Verificou-se, por intermédio de sete proposições de pesquisas, que a VBR e a TI fornecem referências complementares para entender a relação entre gestão ambiental e vantagem competitiva. A vantagem competitiva, nos termos da VBR, é movida pela capacidade de a empresa em desenvolver e acumular recursos ecológicos valiosos, raros, imperfeitamente imitáveis, insubstituíveis e não-comercializáveis capazes de causar heterogeneidade em relação aos seus concorrentes. A TI evidenciou que as empresas possuem percepções distintas acerca das pressões sociais de natureza ecológicas, porém, reações em direção ao isomorfismo tendem a reduzir o potencial de geração de vantagem competitiva das estratégias ambientais.
O Solo Epistemológico de Michel Foucault: Possibilidades de Pesquisa no Campo da Administração
Authors: Costa Flávia Zimmerle da Nóbrega , Guerra José Roberto Ferreira , Leão André Luiz Maranhão de Souza
Published: April 2013

Tendo em vista a crise paradigmática contemporânea, colaboramos para a corrente de defensores da possibilidade crítica na construção teórico-empírica para o campo da Administração, debruçando-nos sobre o pensamento de um dos principais filósofos do conhecimento na contemporaneidade: Michel Foucault. Desta forma, este artigo tem por objetivo abordar o conceito de solo epistemológico de Michel Foucault como uma possibilidade para que uma nova ótica crítica seja aplicada à compreensão dos fenômenos no campo da Administração. Tendo em vista a compreensão do complexo legado de Foucault, iniciamos contextualizando a trajetória teórica do filósofo nos dois ciclos interligados de sua trajetória intelectual (arqueologia e genealogia), apoiados na noção de episteme, dispositivo e prática. Abordamos, desse modo, alguns conceitos-chave de sua produção teórica, estabelecendo suas relações. Concluímos o artigo apresentando possibilidades de aplicação do método para o campo da Administração, entendendo que sua compreensão poderá promover a produção de conhecimento crítico para a área.
Criação de empresas: um processo mais rápido e fácil resulta em empresas de melhor desempenho?
Authors: Borges Cândido , Filion Louis Jacques , Simard Germain
Published: April 2013

As pesquisas realizadas sobre o desempenho de novas empresas se concentraram principalmente em analisar a influência das características e dos recursos dos empreendedores e das empresas sobre este desempenho. Poucos foram os estudos que investigaram a influência do processo de criação de uma empresa sobre o seu desempenho. Em resposta a essa lacuna, o objetivo deste artigo consiste em investigar se dois dos elementos do processo de criação - o tempo que os empreendedores necessitam para criar uma empresa e as dificuldades que eles encontram durante a criação - influenciam o desempenho da nova empresa. A pesquisa consistiu em um survey com 175 novas empresas. Os resultados indicam que o desempenho e a rapidez com que estas atividades são realizadas são dois fatores independentes, que não exercem efeitos um sobre o outro. Sobre o segundo elemento – o grau de dificuldades encontrado –, os resultados mostram que no processo de criação existem dificuldades ligadas aos recursos financeiros (acesso e gestão) e ao mercado (compreensão, avaliação e acesso) que influenciam o desempenho das novas empresas.
Characterization of photochemical pollution at different elevations in mountainous areas in Hong Kong
Authors: Guo H. , Ling Z. H. , Cheung K. , Jiang F. , Wang D. W. , Simpson I. J. , Barletta B. , Meinardi S. , Wang T. J. , Wang X. M. , Saunders S. M. , Blake D. R.
Published: April 2013

Abstract. To advance our understanding on the factors that affect photochemical pollution at different elevations in mountainous areas, concurrent systematic field measurements (September to November 2010) were conducted at a mountain site and at an urban site at the foot of the mountain in Hong Kong. The mixing ratios of air pollutants were greater at the foot of the mountain (i.e., Tsuen Wan urban site, TW) than near the summit (i.e., Tai Mao Shan mountain site, TMS), expect for ozone. In total, only one O3 episode day was observed at TW, whereas twenty-one (21) O3 episode days were observed at TMS. The discrepancy of O3 at the two sites was attributed to the mixed effects of NO titration, vertical meteorological conditions, regional transport and mesoscale circulations. The lower NO levels at TMS and the smaller differences of "oxidant" Ox (O3 + NO2) between the two sites suggested that variations of O3 at the two sites were partly attributed to different degree of NO titration. In addition, analysis of vertical structure of meteorological variables revealed that the inversion layer at the range of altitudes of 500–1000 m might be another factor that caused the high O3 levels at TMS. Furthermore, analyses of the wind fields, the levels of air pollutants in different air flows, ratios of different trace gases and the correlation between variability and the lifetime of VOCs (volatile organic compounds) indicated that high O3 concentrations at TMS were somewhat influenced by regional air masses from the highly polluted Pearl River delta (PRD) region. In particular, the diurnal profiles and correlations of gaseous pollutants suggested influence of mesoscale circulations, which is confirmed using the Master Chemical Mechanism moving box model (Mbox) and the Weather Research and Forecasting (WRF) model. By investigating the correlations of observed O3 and NOx* and the relationships of O3 and its precursors by an observation-based model (OBM), as well as the ratios of VOC/NOx, it was concluded that photochemical O3 formation at TMS was mostly influenced by VOCs, with measurable impact of NOx, while O3 production at TW was generally limited by the concentrations of VOCs. This is the first report of the comprehensive analysis on the data of photochemical pollution obtained from concurrent measurements in mountainous areas in the PRD region.
Multi-satellite aerosol observations in the vicinity of clouds
Authors: Várnai T. , Marshak A. , Yang W.
Published: April 2013

Abstract. Improved characterization of aerosol properties in the vicinity of clouds is important for better understanding two critical aspects of climate: aerosol–cloud interactions and the direct radiative effect of aerosols. Satellite measurements have provided important insights into aerosol properties near clouds, but also suggested that the observations can be affected by 3-D radiative processes and instrument blurring not considered in current data interpretation methods. This study examines systematic cloud-related changes in particle properties and radiation fields that influence satellite measurements of aerosols in the vicinity of low-level maritime clouds. For this, the paper presents a statistical analysis of a yearlong global dataset of co-located MODIS and CALIOP observations and theoretical simulations. The results reveal that CALIOP-observed aerosol particle size and optical thickness, and MODIS-observed solar reflectance increase systematically in a wide transition zone around clouds. It is estimated that near-cloud changes in particle populations – including both aerosols and undetected cloud particles – are responsible for roughly two thirds of the observed increase in 0.55 μm MODIS reflectance. The results also indicate that 3-D radiative processes significantly contribute to near-cloud reflectance enhancements, while instrument blurring contributes significantly only within 1 km from clouds and then quickly diminishes with distance from clouds.
Chemical characterization and source apportionment of PM2.5 in Beijing: seasonal perspective
Authors: Zhang R. , Jing J. , Tao J. , Hsu S.-C. , Wang G. , Cao J. , Lee C. S. L. , Zhu L. , Chen Z. , Zhao Y.
Published: April 2013

Abstract. In this study, 121 daily PM2.5 (aerosol particle with aerodynamic diameter less than 2.5 μm) samples were collected from an urban site in Beijing in four months between April 2009 and January 2010 representing the four seasons. The samples were determined for various compositions, including elements, ions, and organic/elemental carbon. Various approaches, such as chemical mass balance, positive matrix factorization (PMF), trajectory clustering, and potential source contribution function (PSCF), were employed for characterizing aerosol speciation, identifying likely sources, and apportioning contributions from each likely source. Our results have shown distinctive seasonalities for various aerosol speciations associated with PM2.5 in Beijing. Soil dust waxes in the spring and wanes in the summer. Regarding the secondary aerosol components, inorganic and organic species may behave in different manners. The former preferentially forms in the hot and humid summer via photochemical reactions, although their precursor gases, such as SO2 and NOx, are emitted much more in winter. The latter seems to favorably form in the cold and dry winter. Synoptic meteorological and climate conditions can overwhelm the emission pattern in the formation of secondary aerosols. The PMF model identified six main sources: soil dust, coal combustion, biomass burning, traffic and waste incineration emission, industrial pollution, and secondary inorganic aerosol. Each of these sources has an annual mean contribution of 16, 14, 13, 3, 28, and 26%, respectively, to PM2.5. However, the relative contributions of these identified sources significantly vary with changing seasons. The results of trajectory clustering and the PSCF method demonstrated that regional sources could be crucial contributors to PM pollution in Beijing. In conclusion, we have unraveled some complex aspects of the pollution sources and formation processes of PM2.5 in Beijing. To our knowledge, this study is the first systematical study that comprehensively explores the chemical characterizations and source apportionments of PM2.5 aerosol speciation in Beijing by applying multiple approaches based on a completely seasonal perspective.
An automated system for selective and continuous measurements of vertical thoron profiles for the determination of transport times near the ground
Authors: Plake D. , Trebs I.
Published: April 2013

Abstract. The quantification of in-canopy transport times is of major importance for the investigation of sources, sinks and net fluxes of reactive trace gases within plant canopies. The Damköhler number, which compares timescales of chemical reactions with transport times, is a widely applied measure to evaluate flux divergences. In this study we present and evaluate a novel automated measurement system for selective vertical thoron (Tn) profiles near the Earth's surface and demonstrate its suitability for the direct and reliable determination of transport times within a natural grassland canopy. For the first time, we perform a rigorous determination of systematic and random uncertainties of Tn (and Rn) concentrations under field conditions for this type of measurement system. The obtained median precisions for three concentration classes (> 100 Bq m−3, 100–15 Bq m−3, < 15 Bq m−3) were 8.8%, 23.2% and 132.1% for Tn (and 16.6%, 25.0%, 99.2% for Rn). We calculate in-canopy transport times (τ) and propagate their uncertainty from the individual errors of the Tn concentration measurements. A quality assessment of τ for the field experiment during a period of 51 days revealed good data quality with 44% of the relative uncertainties below 50%. The occurrence of transport time uncertainties higher than 100% was caused by absolute Tn gradients lower than 70 Bq m−3 m−1, which was found for 22% of all determined transport times. In addition, the method was found to be highly sensitive to the Tn concentrations at the upper of the two inlet heights (zu). Low values of CTnzu result in high absolute uncertainties of the transport time. A comparison with empirical parameterizations revealed a much lower scatter for the τ values determined from our measurements. We found an excellent agreement with τ values obtained by the in-canopy resistance approach used, e.g., in the SURFATM model during daytime, while the SURFATM model significantly overestimated transport times during nighttime.
The distribution of soil phosphorus for global biogeochemical modeling
Authors: Yang X. , Post W. M. , Thornton P. E. , Jain A.
Published: April 2013

Abstract. Phosphorus (P) is a major element required for biological activity in terrestrial ecosystems. Although the total P content in most soils can be large, only a small fraction is available or in an organic form for biological utilization because it is bound either in incompletely weathered mineral particles, adsorbed on mineral surfaces, or, over the time of soil formation, made unavailable by secondary mineral formation (occluded). In order to adequately represent phosphorus availability in global biogeochemistry–climate models, a representation of the amount and form of P in soils globally is required. We develop an approach that builds on existing knowledge of soil P processes and databases of parent material and soil P measurements to provide spatially explicit estimates of different forms of naturally occurring soil P on the global scale. We assembled data on the various forms of phosphorus in soils globally, chronosequence information, and several global spatial databases to develop a map of total soil P and the distribution among mineral bound, labile, organic, occluded, and secondary P forms in soils globally. The amount of P, to 50cm soil depth, in soil labile, organic, occluded, and secondary pools is 3.6 ± 3, 8.6 ± 6, 12.2 ± 8, and 3.2 ± 2 Pg P (Petagrams of P, 1 Pg = 1 × 1015g) respectively. The amount in soil mineral particles to the same depth is estimated at 13.0 ± 8 Pg P for a global soil total of 40.6 ± 18 Pg P. The large uncertainty in our estimates reflects our limited understanding of the processes controlling soil P transformations during pedogenesis and a deficiency in the number of soil P measurements. In spite of the large uncertainty, the estimated global spatial variation and distribution of different soil P forms presented in this study will be useful for global biogeochemistry models that include P as a limiting element in biological production by providing initial estimates of the available soil P for plant uptake and microbial utilization.
Prediction of railway induced ground vibration through multibody and finite element modelling
Authors: Kouroussis G. , Verlinden O.
Published: April 2013

Abstract. The multibody approach is now recognized as a reliable and mature computer aided engineering tool. Namely, it is commonly used in industry for the design of road or railway vehicles. The paper presents a framework developed for predicting the vibrations induced by railway transportation. Firstly, the vehicle/track subsystem is simulated, on the basis of the home-made C++ library EasyDyn, by mixing the multibody model of the vehicle and the finite element model of the track, coupled to each other through the wheel/rail contact forces. Only the motion in the vertical plane is considered, assuming a total symmetry between left and right rails. This first step produces the time history of the forces exerted by the ballast on the foundation, which are then applied to a full 3-D FEM model of the soil, defined under the commercial software ABAQUS. The paper points out the contribution of the pitch motion of the bogies and carbodies which were neglected in previous publications, as well as the interest of the so-called coupled-lumped mass model (CLM) to represent the influence of the foundation in the track model. The potentialities of the model are illustrated on the example of the Thalys high-speed train, riding at 300 km h−1 on the Belgian site of Mévergnies.
The association between renal tumour scoring systems and ischemia time during open partial nephrectomy
Authors: Lavallée Luke T. , Desantis Darren , Kamal Fadi , Blew Brian , Watterson James , Mallick Ranjeeta , Fergusson Dean , Morash Christopher , Cagiannos Ilias , Breau Rodney H.
Published: April 2013

Objective: To evaluate the association between renal tumour scoring systems and open partial nephrectomy ischemia time.Methods: A historical cohort of open partial nephrectomy patients at The Ottawa Hospital between 2002 and 2009 was reviewed. Preoperative patient characteristics (age, gender, preoperative renal function, diabetes, hypertension, smoking history, heart disease) and ischemia time were abstracted from medical records. Preoperative computed tomography (CT) images were reviewed and tumours were characterized using three scoring systems: (1) R.E.N.A.L. nephrometry score (radius, exophytic/endophytic properties, nearness of tumour to the collecting system or sinus in millimetres, anterior/posterior, location relative to polar lines); (2) preoperative aspects and dimensions used for anatomic (PADUA) classification; and (3) Centrality index (C index). Patients without preoperative CT and patients treated with laparoscopic partial nephrectomy were excluded.Results: During the study period, 78 patients met the inclusion criteria. Median R.E.N.A.L. score was 7 (interquartile range [IQR] 5-8), median PADUA score was 8 (IQR 7-10), and mean C index was 3.9 (standard deviation [SD] 2.1). Mean ischemia time was 23.4 (SD 10.8) minutes. Five individual tumour characteristics (diameter, nearness to collecting system, anterior/posterior location, medial/lateral location, and collecting system involvement) were strongly associated with ischemia time (p < 0.05). Increased R.E.N.A.L. score (1.5 minutes per unit 95%CI 0.08, 2.9, p = 0.04) and PADUA score (2.0 minutes per unit 95%CI 0.5, 3.5, p = 0.009) were significantly associated with ischemia time. An increasing C index score was also associated with ischemia time (-1.1 minutes per unit 95%CI -2.2, 0.04, p = 0.06), but the association was not statistically significant.Conclusion: Renal tumour characteristics are associated with ischemia time. The proposed scoring systems are useful descriptors of surgical complexity and should be used when describing partial nephrectomy patients. Prospective evaluation and refinement of scoring systems are required to create an optimized model prior to widespread application.
Incremental costs of prostate cancer trials: Are clinical trials really a burden on a public payer system?
Authors: Jones Britney , Syme Rachel , Eliasziw Misha , Eigl Bernhard J.
Published: April 2013

Introduction: Clinical trials are a critical component of improving cancer prevention and treatment strategies. However, the perception that patients enrolled in trials consume more resources than those receiving the standard-of-care (SOC) has contributed to an increasingly research-averse environment. Current economic data pertaining to the per-patient costs of prostate cancer trials relative to SOC treatment are limited.Methods: A retrospective observational cohort study was conducted to compare costs incurred by 59 prostate cancer patients participating in a mix of industry and non-industry sponsored clinical trials with costs incurred by an equal number of eligible nonparticipants who received SOC over a year. Resource utilization was tracked and quantified to standardized price templates.Results: No difference in overall resource utilization was seen between trial and SOC patients (two-tailed t-test, n = 118, p = 0.99). Variability in the types of resources used by each group indicated that, while trial patients may take up significantly more clinic time (p = 0.001) and undergo more tests and procedures (p = 0.001), SOC patients are more likely to receive other costly interventions, such as radiation therapy (p < 0.001). Other variables (e.g., pathology, diagnostic imaging, prescribed therapies) were statistically indistinguishable between groups.Conclusion: This study revealed differences in the cost distribution of patients enrolled in clinical trials versus those receiving SOC, which could be used to improve resource allocation. The lack of evidence for a difference in overall cost provides an argument for payers to more fully support clinical research without fear of adverse financial consequences. Further analysis is required.
Le développement de l’échelle POSITIVES : satisfaction des étudiants en situation de handicap concernant les technologies de l’information et de la communication
Authors: Nguyen Mai Nhu , Fichten Catherine S. , Budd Jillian
Published: April 2013

L’échelle POSITIVES (Postsecondary Information Technology Initiative Scale) porte sur les réponses de 141 étudiants francophones canadiens de niveau postsecondaire en situation de handicap concernant la satisfaction de leurs besoins reliés aux technologies de l’information et de la communication (TIC). Cet article a pour objectif de présenter des données sur les propriétés psychométriques de l’échelle et d’en proposer des utilisations futures. Sa fidélité et sa validité sont excellentes. Les résultats indiquent qu’en général l’accessibilité des sites Web et services en ligne des établissements, les heures d’accès à ces technologies et les formats alternatifs des matériels de cours sont adéquats. Par contre, la formation hors campus à ce sujet et la disponibilité des ordinateurs adaptés dans les établissements sont problématiques.
« Qui sont les terroristes ? » Lutte de classement autour de la radicalité mapuche
Authors: Barbut Michael
Published: April 2013

Dans le sud du Chili, depuis les années 1990 et l’enclenchement de la « transition à la démocratie », on a assisté à la multiplication d’actions de protestation mapuche, principal peuple indien du Chili, autour de la revendication de droits territoriaux et fonciers.

Ces actions défiant la propriété privée et la légalité ont vite été catégorisées comme l’expression d’un « nouveau radicalisme indigène » par la presse, et sanctionnées par la multiplication d’actions en justice contre leurs supposés auteurs, labéllisés comme « extrémistes », voire « terroristes ». Le présent article s’attache, à partir de l’évolution des mobilisations mapuche, à montrer que la radicalité n’est pas une essence et qu’elle doit avant tout être appréhendée comme une lutte de classement.
La norme de radicalité dans les mouvements transnationaux pour la paix dans le conflit israélo - palestinien et l’action directe non violente
Authors: Beauzamy Brigitte
Published: April 2013

Dans un contexte de conflit armé où la radicalité est souvent associée aux actions des acteurs violents, la pratique de la non-violence revendiquée par de nombreux mouvements pour la paix est souvent construite comme non radicale. La catégorie de la radicalité est cependant mobilisée dans les discours des mouvements pour la paix où elle prend une connotation positive, associée à des positions éthiques de non-compromission et de mise en danger des activistes. Dans les cas des mouvements transnationaux pour la paix dans le conflit israélo-palestinien, elle constitue également un puissant moteur d’unification des mouvements.
Pour une socioscénologie : de la métaphore théâtrale à sa conceptualisation
Authors: Dubois Jérôme
Published: April 2013

Pour étudier les apports heuristiques et épistémologiques du théâtre en tant qu’objet à la fois métaphorique et conceptuel, nous en ferons d’abord une généalogie à travers l’histoire des idées de la sociologie, pour illustrer ensuite sa pertinence en dégageant ce que nous appelons une socioscénologie, en établissant les principes d’usage de la métaphore, puis la pertinence d’une sociopoétique du quotidien, une homologie épistémologique du poète et du sociologue, pour aborder enfin des aspects méthodologiques, en nous reportant tout du long aux avancées de la sociologie et de l’ethnoscénologie.
La variable tiempo en la enseñanza universitaria
Authors: Zabalza Miguel A.
Published: April 2013

La importancia del tiempo (de los tiempos) en Educación ha estado presente en la literatura pedagógica desde los estudios iniciales de Carrol (1963) y los posteriores estudios longitudinales de Fisher mediante el California Beginning Teachers Evaluation Study (BTES). En los momentos actuales, la problemática de los tiempos ha adquirido un nuevo impulso en el marco de los nuevos enfoques curriculares que buscan una mayor homogeneidad en el diseño de las carreras que facilite la movilidad de los estudiantes. Parte de ese proceso es la incorporación de los créditos (ECTS, en Europa; SCT en Latinoamérica). El artículo analiza el factor tiempo desde una triple perspectiva: (a) el tiempo del currículo; (b) el tiempo de los profesores; y (c) el tiempo de los estudiantes. El autor defiende que, en todos los casos, la consideración de la variable tiempo está siendo marginal y sobre todo que su interpretación mecánica y burocrática deja fuera de consideración elementos fundamentales de la didáctica universitaria.
Programa universitário (50+) ou do questionamento de crenças tomadas pela medusa
Authors: Palmeirão Cristina , Amorim José Pedro
Published: April 2013

Neste artigo, é nossa intenção refletir e analisar, ainda que de uma forma exploratória,três dimensões essenciais – a relação pedagógica, o currículo e a avaliação – subjacentes à realização por alunos com mais de 50 anos de um Programa Universitário promovido pelo Centro Regional do Porto da Universidade Católica Portuguesa. Numa expressão que não perfilhamos, diríamos tratar-se de uma oferta “não tradicional” para estudantes “não tradicionais”. Paradoxalmente, este “não” exprime não um défice, mas uma riqueza nada despicienda – de experiências (de vida, profissionais, mas também, as mais das vezes, de educação formal, pelo facto de a maioria dos alunos ser, pelo menos, licenciada), de memórias (passado), bem como de atividade (presente), desejos e expectativas (futuro)! Então, e justamente pelo facto de ser “não tradicional”, este Programa tem, por um lado, implicado um esforço no sentido de repensar alguns dos processos e procedimentoshabituais da Universidade; por outro, tem trazido dados que nos podem levar a questionar algumas crenças associadas à Educação de adultos.
Práticas pedagógicas na perspectiva do hibridismo tecnológico digital
Authors: Backes Luciana , Schlemmer Eliane
Published: April 2013

Atualmente, as Tecnologias Digitais (TD) apresentam inúmeras possibilidades para a interação, a comunicação e a representação do conhecimento, favorecendo a configuração de espaços digitais virtuais de convivência, que potencializam os processos de ensinar e de aprender, numa perspectiva de hibridismo tecnológico digital. Nesse contexto, emergem questões como: quais são os aspectos no processo de ensinar e de aprender que contribuem para a configuração dos espaços de convivência no contexto do hibridismo tecnológico digital? Quais as características da prática pedagógica que podem favorecer uma formação para este tempo e este espaço? Para tanto, foram desenvolvidos processos de formação no Ensino Superior, contextos Brasil e França, na perspectiva do hibridismo tecnológico digital, o qual comportou as seguintes TD: ambiente virtual de aprendizagem; comunicador instantâneo; blog e metaverso. Os processos formativos se desenvolveram por meio da Metodologia de Projetos de Aprendizagem baseado em Problema (Brasil) e da Metodologia Pedagógica de Estudo de Caso (França). Os dados empíricos são as representações expressas nas TD, no processo de interação dos estudantes, submetidas à metodologia de análise de conteúdo. A análise de conteúdo, realizada no contexto das unidades de análise, passou por tratamentos de natureza qualitativa, quantitativa e, novamente, qualitativa. Esta análise complexa nos instigou à reflexão sobre as práticas pedagógicas como possibilidade de problematizar a realidade atual, utilizando as TD de maneira congruente. Assim, os estudantes são instigados a (re)significar a realidade atual, numa condição de responsabilidade em relação às TD, a fim de encontrar alternativas para a emancipação na construção de novos conhecimentos.
Evolution of Gene Expression in Human and Chimpanzee Brains
Authors: Osada Naoki , Sumio Sugano , Suzuki Yutaka
Published: April 2013

It has long been proposed that for creating diverse phenotypes in closely related species, such as a striking difference between human and chimpanzee brain functions, evolutionary changes in gene expression are more important than the changes in protein structure. High‐throughput detection methods make it possible to gauge the differences in gene expression at the genome‐wide level. Initial studies using
deoxyribonucleic acid
microarrays have shown that gene expression evolution is more conserved in the brain than in other tissues. However, those studies have also shown that the divergence rate of gene expression in the brain is higher in humans than in the chimpanzee lineage. Subsequent studies have identified detailed differences in gene expression such as alterations in network connectivity and temporal order. In addition to the expression of protein‐coding genes, the expression of noncoding RNAs may also affect the divergence of gene expression and contribute to the phenotypic differences between humans and chimpanzees.

Key Concepts:

Differences in gene expression patterns rather than the changes in protein structures may have contributed to the functional differences between human and chimpanzee brains.

The set of genes that have different expression patterns in human and chimpanzee brains can be identified using high‐throughput methods such as DNA microarrays and RNA‐Seq.

Although we can detect functional gene expression changes specific to the human brain, it is not easy to elucidate the underlying evolutionary mechanisms.

Gene expression is a complex trait; understanding the molecular mechanisms of brain development is important to unveil the genetic basis of brain evolution.

Several studies revealed that the pattern of gene expression evolution in human brains was highly conservative in general, but showed acceleration after the split from the chimpanzee lineage.
Reconstruction of Ancestral Genomes
Authors: Stanyon Roscoe , Bigoni Francesca
Published: April 2013

Comparative genomics allow hypotheses about the content of the genome of ancestral species and for many major branching points on the tree of life, hypothetical ancestral genomes can be reconstructed. Cross‐species chromosome painting over the last two decades has led the way in the reconstruction of ancestral genomes. Chromosome painting techniques allow to rapidly track chromosome translocations in evolution. A cladistic analysis of syntenies and chromosome associations allows rearrangements to be placed on the evolutionary tree. More recently, assemblies of genome sequences have allowed more far ranging comparisons of vertebrate genome evolution. The

in‐situ

hybridisation of the
deoxyribonucleic acid (DNA)
cloned into bacterial artificial chromosome overcomes the limitations of chromosome painting permitting the reconstruction of ancestral marker order along the single chromosome and has revealed that centromeres can reposition during evolution. These reconstructions provide insight into the evolutionary forces that have sculpted the genomes of extant species.

Key Concepts:

All forms of life on this planet are connected by descent from common ancestors.

Hypothetical ancestral genomes can be reconstructed at various nodes on the tree of life.

FISH is the major technique of comparative molecular cytogenetics.

Chromosome painting can detect chromosomal homologies even between distantly related mammalian orders.

Chromosomal syntenies may often be fragmented but it is highly unlikely that the same syntenic group can be brought together independently in different lineages.

Chromosome associations are segments homologous to different human chromosomes that are found contiguously in genomes of other species.

Chromosome painting maps are now available for about 200 mammalian species from all eutherian orders.

Bioinformatics provided an alternative approach to reconstructing ancestral genomes from the comparison of complete genome assemblies.

Integration between molecular cytogenetics, sequencing and bioinformatics will allow even more refined hypotheses about genome evolution.
Dual‐Coding Regions in Alternatively Spliced Human Genes
Authors: Liang Han , Landweber Laura F
Published: April 2013

In eukaryotes, a coding
deoxyribonucleic acid (DNA)
sequence usually encodes amino acids in one reading frame only. However, by using different exon combinations, alternatively spliced genes may contain dual‐coding regions, where more than one reading frame encodes amino acid sequences. In recent years, quite a few studies have systematically identified such dual‐coding regions in the human genome. These special coding regions generate functionally related but distinct protein products, and they have evolved under unusual selective forces, with fewer synonymous sites. This article will first introduce the concept of dual‐coding regions in alternatively spliced genes through several well‐characterised examples, and then discusses the computational methods for detecting such regions and elucidating their evolutionary constraints and finally discusses the potential selective advantages.

Key Concepts:

The open reading frame in a DNA sequence defines the encoded amino acid sequences.

Particularly low synonymous substitution rate suggests the presence of overlapping reading frames.

During translation, ribosomes move along an mRNA not by one nucleotide, but by one codon at a time.

The presence of in‐frame stop codons indicates that the ORF no longer encodes a functional protein product.

Two reading frames of a dual‐coding region resulting from alternative splicing are in the same strand whereas those resulting from other mechanisms may be in different strands.
Human‐specific Accelerated Evolution of Noncoding Sequences
Authors: Webster Matthew T
Published: April 2013

Mutations in functional noncoding elements are likely to be responsible for a large fraction of phenotypic evolution. There is considerable interest in identifying genes and genomic regions under positive selection on the human lineage, as they may govern the traits that make us unique. Several studies have attempted to identify functional noncoding elements under positive selection in the human lineage by identifying those with evidence of accelerated evolutionary rates since the common ancestor of humans and chimpanzees. These studies have identified a catalogue of human‐accelerated regions (HARs). Two of the most extremely accelerated HARs are implicated in controlling human‐specific morphology and cognition. However, detailed analyses of the forces governing the evolution of HARs suggest that a number of different processes distinct from positive selection may be involved in their accelerated rates. These include relaxation of constraint, variation in mutation rate and GC‐biased gene conversion.

Key Concepts:

Noncoding genomic regions under evolutionary constraint are likely to be functional elements such as the transcription binding sites.

Evolutionarily constrained elements that have undergone accelerated evolution on the human lineage are candidates for governing human‐specific traits.

Positive selection represents a bias towards fixation of alleles conferring an increased fitness.

GC‐biased gene conversion (gBGC) is a recombination‐associated process that increases the probabilty of fixation of G and C nucleotides independent of their fitness.

Multiple processes, including positive selection and gBGC are implicated in governing the evolution of human‐accelerated regions.
Genetics of Disordered Gambling
Authors: Slutske Wendy S
Published: April 2013

There is evidence from twin studies that genetic variation contributes to individual differences in the risk for disordered gambling (DG), and that some of this genetic variation overlaps with the genetic risk for other comorbid disorders such as alcohol dependence, antisocial behaviour disorders and major depression. It is likely that the specific genes that contribute to DG risk will be of small effect; there are no established susceptibility genes for DG. The most promising candidates based on theory and cumulative evidence are dopamine system genes. Other interesting leads come from the norepinephrine system, including the
ADRAC2
and
MAO‐A
genes, and several novel variants identified in a recent genome‐wide association study. Genetic research on DG is in its infancy, with most of the interesting findings based on single unreplicated studies. There is much uncharted territory in research on the genetics of DG.

Key Concepts:

Disordered gambling affects approximately 1–2% of the population in the United States, and many individuals who do not qualify for a clinical diagnosis may also experience substantial harms from their gambling involvement.

There are cross‐national and cross‐temporal differences in the prevalence of disordered gambling, highlighting the importance of nongenetic factors.

Twin studies suggest that the variation in risk for disordered gambling among adults is due to genetic and unique environmental influences, with no evidence for an important role of the shared family environment.

The contribution of genes and environment to disordered gambling risk appears to be similar among men and women.

Genetic variation in disordered gambling risk overlaps with the genetic risk for other comorbid disorders such as alcohol dependence, antisocial behaviour disorders and major depression.

Genetic susceptibility for DG will also include those genes related to individual differences in the earlier stages of gambling involvement.

Like other complex polygenic disorders, genetic variation in disordered gambling risk appears to be due to many genes of small effect.

There are no known susceptibility genes for disordered gambling; the most promising candidates are the dopamine system genes, with other interesting leads from the norepinephrine system.

The much‐needed research on disordered gambling endophenotypes will improve the understanding of the pathways from genes to disordered gambling and may facilitate efforts to identify susceptibility genes.

There is little research evaluating the potential disordered gambling endophenotypes, but the broader disordered gambling literature suggests that neural systems, cognitive distortions and decision making, personality traits such as impulsivity and negative emotionality, and loss‐chasing are viable candidates.
RNA
Therapy for Polyglutamine Neurodegenerative Diseases
Authors: Smith Danielle C , Watson Lauren M , Greenberg Jacquie LJ , Wood Matthew JA , Scholefield Janine
Published: April 2013

The polyglutamine neurodegenerative diseases are caused by the expansion of a CAG repeat, which is translated into an extended polyglutamine tract in the disease‐causing protein. Although arising from a common type of mutation, the mechanisms by which each polyglutamine protein exerts its cellular toxicity are complex. RNA‐based approaches represent promising therapeutic strategies, offering the potential to target and suppress the expression of polyglutamine disease genes in a sequence‐specific manner, upstream of the deleterious effects of the mutant protein. In particular, allele‐specific therapies, which selectively silence the mutant copy of the gene while retaining the wild‐type function, may prove useful in cases where wild‐type gene expression is known to be indispensable. With a variety of RNA technologies currently being developed to target multiple polyglutamine disease genes, the initiation of clinical trials appears imminent. However, the numerous challenges associated with design, dosage and delivery optimisation must be addressed before such therapies can be effectively applied in a clinical setting.

Key Concepts:

The elucidation of an effective therapy for any of the inherited polyglutamine repeat disorders may contribute to the alleviation of the global health burden.

Because many of the polyglutamine pathogenic mechanisms involve the toxic protein and its intermediates, the most logical therapeutic strategy may be to prevent pathogenesis upstream of these effects.

Gene‐based therapies have been heralded as the most promising avenue for therapeutic research, because they may allow for prevention or reversal of disease progression through altering the expression, processing or conformation of the mutant protein.

Various RNA‐based targeting strategies for the polyglutamine repeat disorders have been explored, including repeat targeting, allele‐specific silencing, nonallele‐specific silencing and gene knockdown and replacement.

Numerous guidelines exist for the design, delivery and dosage of therapeutic effectors.

Cell‐based and animal models have contributed significantly towards the testing and improvement of potential therapies, paving the way to clinical application.
Mixed Aerogels from Au and CdTe Nanoparticles
Authors: Hendel Thomas , Lesnyak Vladimir , Kühn Laura , Herrmann Anne‐Kristin , Bigall Nadja C. , Borchardt Lars , Kaskel Stefan , Gaponik Nikolai , Eychmüller Alexander
Published: April 2013

Mixed metal–semiconductor nanocrystal aerogels are fabricated, which are light‐emitting and highly porous macroscopic monoliths. Thiol‐stabilized CdTe and Au nanoparticles from aqueous synthesis act as building blocks for the hybrid material. The Au colloids undergo a surface‐modification to enhance the particle stability and achieve thiol functionalities. A photochemical treatment is applied for the gelation process which is found to be reversible by subsequent addition of thiol molecules. Via supercritical drying aerogels are formed. The variation of the initial CdTe to Au nanoparticle ratio permits a facile tuning of the content and the properties of the resulting aerogels. The obtained structures were characterized by means of optical spectroscopy, electron microscopy, elemental analysis, and nitrogen physisorption.
Novel ways to assess forested wetland restoration in North Carolina using ecohydrological patterns from reference sites
Authors: Johnson Yari Ben , Shear Theodore Henry , James April Lynda
Published: April 2013

Restoring jurisdictional wetland hydrology does not ensure that the hydrologic conditions of any specific natural forested wetland community are recreated. This is especially problematic for a state like North Carolina, which has roughly two dozen different forested wetland communities. Because forested wetland communities align themselves across edaphic and hydrologic gradients, we suggest exploiting these relationships to guide restoration design and set performance standards. However, methods to compare hydrology between multiple reference sites and restored wetlands are lacking. To address this, we studied three different forested wetlands across 13 reference sites to determine which measures of water table levels, based on correlation with plant community composition, would be useful to distinguish these three communities. We then used the best measures of water table levels to assess two restoration sites and compare them with the reference sites. Our results showed that monthly median water table levels encompassing the start of the growing season had the strongest correlation with plant community composition, whereas roughly five other measures also had strong correlations. On the basis of the best measures, both of the restoration sites had water table levels that generally fell within the natural range of the reference sites. Because there was variation in water table levels across each restoration site, the different measures where useful to identify which areas were least similar to the reference sites and might need further monitoring in the future. On the basis of our results, we recommend using community‐specific measures of hydrology to guide and assess forested wetland restoration. Copyright © 2013 John Wiley & Sons, Ltd.
Copper biosorption in the presence of lead onto olive stone and pine bark in batch and continuous systems
Authors: Ronda Alicia , Martín‐Lara María Ángeles , Blázquez Gabriel , Bachs Nuria Moreno , Calero Mónica
Published: April 2013

In the present work, biosorption of copper(II) in the presence of lead(II) ions by olive stone and pine bark was investigated in batch and continuous mode. Particularly, it pretends provide new information regarding binary biosorption of metals in continuous flow. The behavior of competitive Cu(II) and Pb(II) biosorption in batch was successfully described by the multicomponent Sips model, obtaining maximum capacities for Cu(II) and Pb(II) of 1.34 and 2.12 mg/g, respectively for olive stone, and 6.05 and 10.04 mg/g, respectively, for pine bark. Olive stone and pine bark removed the target metal ions in the selectivity order of Pb(II)>Cu(II). In continuous mode the biosorption capacity for Pb(II) (6.59 and 26.01 mg/g for olive stone and pine bark, respectively) were also higher than copper one (2.19 and 12.66 mg/g for olive stone and pine bark, respectively), indicating the higher affinity of lead for the two biosorbents in continuous system too. Finally, the results of this study demonstrated that pine bark could be a better biosorbent than olive stone. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 192–204, 2014
Factors associated with help‐seeking behaviors in Mexican older individuals with depressive symptoms: a cross‐sectional study
Authors: Pérez‐Zepeda Mario Ulises , Arango‐Lopera Victoria Eugenia , Wagner Fernando A. , Gallo Joseph J. , Sánchez‐García Sergio , Juárez‐Cedillo Teresa , García‐Peña Carmen
Published: April 2013

Objective

Depression in the older individuals is associated with multiple adverse outcomes, such as high health service utilization rates, low pharmacological compliance, and synergistic interactions with other comorbidities. Moreover, the help‐seeking process, which usually starts with the feeling “that something is wrong” and ends with appropriate medical care, is influenced by several factors.

The aim of this study was to explore factors associated with the pathway of help seeking among older adults with depressive symptoms.

Methods

A cross‐sectional study of 60‐year or older community dwelling individuals belonging to the largest health and social security system in Mexico was carried out. A standardized interview explored the process of seeking health care in four dimensions: depressive symptoms, help seeking, help acquisition, and specialized mental health.

Results

A total of 2322 individuals were studied; from these, 67.14% (n = 1559) were women, and the mean age was 73.18 years (SD = 7.02); 57.9% had symptoms of depression; 337 (25.1%) participants sought help, and 271 (80.4%) received help; and 103 (38%) received specialized mental health care. In the stepwise model for not seeking help (χ2 = 81.66, p < 0.0001), significant variables were female gender (odds ratio (OR) = 0.7, 95% confidence interval (CI) 0.511–0.958, p = 0.026), health‐care use (OR 3.26, CI 95% 1.64–6.488, p = 0.001). Number of years in school, difficulty in activities, Short Anxiety Screening Test score, and indication that depression is not a disease belief were also significant.

Conclusions

Appropriate mental health care is rather complex and is influenced by several factors. The main factors associated with help seeking were gender, education level, recent health service use, and the belief that depression is not a disease. Detection of subjects with these characteristics could improve care of the older individuals with depressive symptoms. Copyright © 2013 John Wiley & Sons, Ltd.