bluuebunny/crossref_metadata_2025 huggingface dataset:
The relation between cognitive and motor dysfunction and motor imagery ability in patients with multiple sclerosis
Authors: Heremans Elke , D’hooge Anne-Marie , De Bondt Sara , Helsen Werner , Feys Peter
Published: March 2012

Background:

Motor imagery (MI) was recently shown to be a promising tool in neurorehabilitation. The ability to perform MI, however, may be impaired in some patients with neurological dysfunction.

Objective:

The objective was to assess the relation between cognitive and motor dysfunction and MI ability in patients with multiple sclerosis (MS).

Methods:

Thirty patients with MS underwent cognitive and motor screening, and also performed a composite test battery to assess their MI ability. This test battery consisted of a questionnaire, a hand rotation task and a test based on mental chronometry. Patients’ MI ability was compared with the MI ability of age-matched healthy controls. Moreover, their MI scores were compared between body sides and were correlated with their scores on tests of motor and cognitive functioning.

Results:

The average accuracy and temporal organization of MI significantly differed between MS patients and controls. Patients’ MI accuracy significantly correlated with impairments in cognitive functioning, but was independent of motor functioning. MI duration, on the other hand, was independent of cognitive performance, but differed between the patients’ most and least affected side.

Conclusion:

These findings are of use when considering the application of MI practice in MS patients’ rehabilitation.
Embodied orientations towards co-participants in multinational meetings
Authors: Markaki Vassiliki , Mondada Lorenza
Published: March 2012

The interactional organization of meetings is an important locus of observation for understanding the way in which institutions are talked into being. This article contributes to this growing body of research by focusing on turn-taking and participation in business meetings, approached within conversation analysis in a sequential and multimodal way. On the basis of a corpus of video-recorded corporate meetings of a multinational company, in which managers coming from several European branches convene, the article takes into consideration the embodied orientations of the participants as they address each other, as they turn to particular addressees or groups in a recipient designed way while describing, informing, announcing events and results, and as they make relevant specific participants’ identities – especially national categories – and, in this way, display specific local expectations regarding rights and obligations to talk and to know.
Safety and tolerability of glucagon-like peptide-1 receptor agonists in the treatment of type 2 diabetes
Authors: Ahluwalia Rupa , Vora Jiten
Published: March 2012

Conventional pharmacotherapies for type 2 diabetes effectively lower blood glucose levels but are associated with side effects that preclude their optimal use or raise safety concerns. Novel treatments based on the endogenous hormone glucagon-like peptide-1 (GLP-1) may overcome some of these obstacles. The GLP-1 receptor agonists, exenatide and liraglutide, have a lower risk of hypoglycaemia than some conventional agents and can provide significant weight loss. Although they can cause gastrointestinal symptoms, effects are transient and can be reduced by gradual dose escalation. No cardiac safety issues have been reported and animal studies suggest that they may confer cardiovascular benefits. Pancreatitis has occurred among patients receiving GLP-1 receptor agonists, but it is unclear whether this is drug-related or due to the increased risk of pancreatitis in type 2 diabetes. Despite findings in rodents that GLP-1 receptor activation of thyroid C-cells results in calcitonin release and C-cell pathology, such effects have not been seen with long-term exposure in humans. Immunogenicity does not appear to be a safety concern. In summary, currently available data indicate that GLP-1 receptor agonists provide an effective and generally well tolerated therapeutic option for the management of type 2 diabetes.
Detecting early microvascular disease in type 1 diabetes: wavelet transform analysis of Doppler blood velocity waveforms
Authors: Hamilton Paul K , Mccann Aaron J , Agnew Christina E , Millar Auleen , Mcclenaghan Vivienne O , Mcgivern R Canice , Mcveigh Gary
Published: March 2012

Diabetic retinopathy is associated with markedly increased risk of cardiovascular events. Analysis of retrobulbar blood velocity waveforms should help characterise microvessels since waveform morphology is partly determined by wave reflection. This approach could potentially allow the detection of abnormalities earlier than is currently possible. Ultrasound examinations of the common carotid, ophthalmic (OA) and central retinal (CRA) arteries were undertaken on 39 subjects with type 1 diabetes (no retinopathy) and 39 controls. Waveforms were characterised using the discrete wavelet transform, and frequency data categorised into 11 bands. After correcting for possible confounders, in the OA, the mean amplitude was higher for subjects with diabetes in band 4 (p=0.022). In the CRA, the mean amplitude was higher for subjects with diabetes in bands 2 (p=0.012), 3 (p<0.001) and 5 (p=0.028). Abnormalities were most pronounced when signals were captured close to the microvasculature, providing evidence that they may be due to microvascular alterations.
The hypocaloric diet in type 2 diabetes - déjà vu
Authors: Day Caroline , Bailey Clifford J
Published: March 2012

Dietary modification is considered a cornerstone in the management of diabetes superimposed upon which are pharmacological therapies as required. The value of hypocaloric diets in reducing and eliminating glycosuria was extolled in the pre-insulin era. A common feature of the nutrient balance of these diets was restriction in the availability of carbohydrate. Herein we review the use of diet as therapy in the past and discuss the rationale for hypocaloric dietary management of type 2 diabetes in the 21st century, drawing comparisons with bariatric surgery and considering why weight loss is particularly difficult for overweight and obese individuals with type 2 diabetes.
Consuming Anime
Authors: Fennell Dana , Liberato Ana S.Q. , Hayden Bridget , Fujino Yuko
Published: March 2012

Researchers are increasingly recognizing anime and manga as worthy of scholarly examination. However, relatively little research examines how fans synthesize the cultural content of anime. This paper provides an analysis of representations of race/ethnicity and gender in two televised anime, and contrasts the understandings of scholars to fans. As anime can weave together images from Japanese culture, other cultures, as well as fantasy, anime presents many faces to fans. Fans do not necessarily see all of these faces at once, and they interpret the cultural content of anime differently. As a result, anime has the potential to generate different types of cultural influence.
The Complementarity of Team Meetings and Cross-Functional Communication
Authors: Boerner Sabine , Schäffner Mélanie , Gebert Diether
Published: March 2012

This article investigates the respective influence of two different forms of communication on performance in new services development teams, namely, formal team meetings and informal cross-functional communication. Based on the work by Gebert and colleagues, the authors suggest a complementary relationship between these two forms of communication. They posit that team meetings enhance knowledge integration but may challenge knowledge generation. Inversely, they posit that cross-functional communication fosters knowledge generation but hinders knowledge integration. The authors therefore expect that cross-functional communication and team meetings will interact to predict team performance. A study on 55 new services development teams in consulting and financial services confirmed the authors’ hypothesis.
Hormones and Their Interaction with the Pain Experience
Authors: Vincent Katy , Tracey Irene
Published: March 2012

• Sex differences in the prevalence of painful conditions appear after puberty • Variation in symptom severity across the menstrual cycle occurs in a number of clinical pain conditions • Sex steroid hormones act at a number of sites in both the peripheral and central nervous systems and in both reproductive and non-reproductive tissues • Sex steroid hormones have traditionally been thought to alter transcription; however, there is evidence that there are also non-genomic effects • Sex steroid hormones can have organisational effects from as early as in utero • The relationship between sex hormones and pain is complex
Parenting an Adolescent with Chronic Pain: Impact on Parents and Association with Adolescent Functioning
Authors: Jordan Abbie
Published: March 2012

• Chronic pain and associated disability is a serious problem for a significant number of adolescents. • Individuals who parent an adolescent with chronic pain report high levels of impaired psychological and social functioning. • Parents of adolescents with chronic pain face unique parenting challenges. • Typically, treatment of adolescent chronic pain does not specifically focus on managing parental functioning and behaviour. • The relationship between parental functioning/behaviour and adolescent outcomes is complex and not yet fully understood.
Primary Headache Disorders: Focus on Migraine
Authors: Bahra Anish
Published: March 2012

• Migraine is the most common disabling headache disorder. • Most patients with disabling tension-type headache are likely to have migraine and accordingly respond to treatments efficacious in migraine. • Individuals are genetically predisposed to experiencing recurrent migraine. • Evidence supports migraine to be a primarily neural and not vascular mediated disorder. • 1–2% of the population have chronic daily headache associated with acute-relief medication overuse; the majority are migraineurs. • The presence of acute-relief medication overuse renders preventative medication less adequately efficacious.
Robust dialogue act detection based on partial sentence tree, derivation rule, and spectral clustering algorithm
Authors: Chen Chia-Ping , Wu Chung-Hsien , Liang Wei-Bin
Published: March 2012

A novel approach for robust dialogue act detection in a spoken dialogue system is proposed. Shallow representation named partial sentence trees are employed to represent automatic speech recognition outputs. Parsing results of partial sentences can be decomposed into derivation rules, which turn out to be salient features for dialogue act detection. Data-driven dialogue acts are learned via an unsupervised learning algorithm called spectral clustering, in a vector space whose axes correspond to derivation rules. The proposed method is evaluated in a Mandarin spoken dialogue system for tourist-information services. Combined with information obtained from the automatic speech recognition module and from a Markov model on dialogue act sequence, the proposed method achieves a detection accuracy of 85.1%, which is significantly better than the baseline performance of 62.3% using a naïve Bayes classifier. Furthermore, the average number of turns per dialogue session also decreases significantly with the improved detection accuracy.
Resolution of reservoir scale electrical anisotropy from marine CSEM data
Authors: Brown Vanessa , Hoversten Mike , Key Kerry , Chen Jinsong
Published: March 2012

A combination of 1D and 3D forward and inverse solutions is used to quantify the sensitivity and resolution of conventional controlled source electromagnetic (CSEM) data collected using a horizontal electric dipole source to transverse electric anisotropy located in a deep-water exploration reservoir target. Because strongly anisotropic shale layers have a vertical resistivity that can be comparable to many reservoirs, we examined how CSEM can discriminate confounding shale layers through their characteristically lower horizontal resistivity. Forward modeling indicated that the sensitivity to reservoir level anisotropy is very low compared with the sensitivity to isotropic reservoirs, especially when the reservoir is deeper than about 2 km below the seabed. However, for 1D models where the number of inversion parameters can be fixed to be only a few layers, both vertical and horizontal resistivity of the reservoir can be well resolved using a stochastic inversion. We found that the resolution of horizontal resistivity increases as the horizontal resistivity decreases. This effect is explained by the presence of strong horizontal current density in anisotropic layers with low horizontal resistivity. Conversely, when the reservoir has a vertical to horizontal resistivity ratio of about 10 or less, the current density is vertically polarized and hence has little sensitivity to the horizontal resistivity. Resistivity anisotropy estimates from 3D inversion for 3D targets suggest that resolution of reservoir level anisotropy for 3D targets will require good a priori knowledge of the background sediment conductivity and structural boundaries.
Giant meiotic spindles in males from Drosophila species with giant sperm tails
Authors: Lattao Ramona , Bonaccorsi Silvia , Gatti Maurizio
Published: March 2012

The spindle is a highly dynamic molecular machine that mediates precise chromosome segregation during cell division. Spindle size can vary dramatically, not only between species but also between different cells of the same organism. However, the reasons for spindle size variability are largely unknown. Here we show that variations in spindle size can be linked to a precise developmental requirement. Drosophila species have dramatically different sperm flagella that range in length from 0.3 mm in D. persimilis to 58.3 mm in D. bifurca. We found that males of different species exhibit striking variations in meiotic spindle size, which positively correlate with sperm length, with D. bifurca showing 30-fold larger spindles than D. persimilis. This suggests that primary spermatocytes of Drosophila species manufacture and store amounts of tubulin that are proportional to the axoneme length and use these tubulin pools for spindle assembly. These findings highlight an unsuspected plasticity of the meiotic spindle in response to the selective forces controlling sperm length.
Molecular Motions and Hydrogen-Bonding Networks in (o-Aminoanilinium)–(Crown Ethers)–[PMo12O40]4− Crystals
Authors: Endo Daigoro , Akutagawa Tomoyuki , Kubo Kazuya , Noro Shin-ichiro , Cronin Leroy , Nakamura Takayoshi
Published: March 2012

Single crystals formed from hydrogen-bonding supramolecular cations of o-aminoanilinium (HOPD+)–crown ethers, (HOPD+)([12]crown-4), (HOPD+)([15]crown-5), and (HOPD+)([18]crown-6), and one-electron-reduced [PMo12O40]4− Keggin-type clusters were synthesized. The crystal structures and dielectric responses of the three new compounds (HOPD+)4([12]crown-4)4[PMo12O40]4−·4CH3CN (1), (HOPD+)4([15]crown-5)4[PMo12O40]4− (2), and (HOPD+)4([18]crown-6)4[PMo12O40]4−·8CH3CN (3) were examined. The CH3CN molecules in salts 1 and 3 were included in zero-dimensional pores and one-dimensional channels, respectively; higher thermal stability was observed in the former lattice because of its extended hydrogen-bonding network. Large frequency- and temperature-dependent dielectric responses were confirmed in salts 2 and 3, whereas the dielectric response of salt 1 was quite small. The fixed orientation of HOPD+ because of the hydrogen-bonding network was consistent with the dielectric property of salt 1. In contrast, large magnitudes of dielectric responses in the temperature range above 280 K were observed for salt 3. Thermal motions of CH3CN molecules in the channel were the origin of such dielectric responses. In salt 2, the thermally activated coupled motion of the orthogonally arranged HOPD+ pair along the C–NH3+-axis with the potential energy barrier of ca. 80 kJ mol−1 resulted in large dielectric responses.
Spontaneous Dispersion of Gold Nanoparticles Loaded on USY Zeolites as Analyzed by XAFS, XRD, and TEM
Authors: Sanada Takashi , Okumura Kazu , Murakami Chika , Oyama Tetsuya , Isoda Ayano , Katada Naonobu
Published: March 2012

Structural changes in the gold particles of Au-loaded ultrastable Y (USY) zeolite were analyzed by X-ray absorption fine structure, X-ray diffraction, and transmission electron microscopy. Au particles undergo spontaneous dispersion on the USY support under H2 atmosphere at a temperature of 773 K to give Au particles with an average diameter of 1.8 nm and narrow size distribution.
The Obstetric Medicine Listserv: review of controversies surrounding thrombophilia testing
Authors: Carson Michael P , Jorn H Keels S
Published: March 2012

A woman with no significant personal or family history of thrombosis asked her internist to obtain a thrombophilia work-up prior to starting the combined oral contraceptive for dysmenorrhoea, after another physician advised her to have the test. The case was sent to an international email discussion group where the consensus was that testing should not be done. The responses of the group and review of this controversial topic are presented.
The Anatomy of the Image: Toward an Applied Onto-Psychiatry
Authors: Fielding James M. , Marwede Dirk
Published: March 2012

Abstract: Biomedical software ontologies provide a means for the representation of facts gathered through biomedical research and clinical observation. At the foundation of good software ontology design lays a sound philosophical realism that supplies the basic framework required to support the computable management of this information correctly and consistently. In numerous biomedical subdomains (such as anatomy, disease classification, or functional genomics), a good degree of success has been achieved through the realist approach. In the field of psychiatry, however, the analytic tools of ontological realism are challenged to account for subjective mental experiences that typically lay beyond their scope. Although psychiatric symptoms , such as delusions, hallucinations, or memory loss, may be too ethereal to account for in terms of a realist ontology, by focusing on some psychiatric signs , such as images of the human brain (which are in themselves subject to ontological analysis), we may be able to make some in-roads toward an application ontology of the psychiatric domain. In this paper, via the ontological framework of Polish phenomenologist Roman Ingarden, we discuss the differences between the ontology of the body and the ontology of the image, and apply the subsequent image-ontology framework to the domain of neuroimaging. We aim to demonstrate how such an ontology may lead to the perspicuous structuring of clinical information in psychiatry and the benefits application ontologies afford may subsequently be attained within a portion of this particularly difficult domain.
Metformin inhibits growth and decreases resistance to anoikis in medullary thyroid cancer cells
Authors: Klubo-Gwiezdzinska Joanna , Jensen Kirk , Costello John , Patel Aneeta , Hoperia Victoria , Bauer Andrew , Burman Kenneth D , Wartofsky Leonard , Vasko Vasyl
Published: March 2012

Medullary thyroid cancer (MTC) is associated with activation of mammalian target of rapamycin (mTOR) signaling pathways. Recent studies showed that the antidiabetic agent metformin decreases proliferation of cancer cells through 5′-AMP-activated protein kinase (AMPK)-dependent inhibition of mTOR. In the current study, we assessed the effect of metformin on MTC cells. For this purpose, we determined growth, viability, migration, and resistance to anoikis assays using two MTC-derived cell lines (TT and MZ-CRC-1). Expressions of molecular targets of metformin were examined in MTC cell lines and in 14 human MTC tissue samples. We found that metformin inhibited growth and decreased expression of cyclin D1 in MTC cells. Treatment with metformin was associated with inhibition of mTOR/p70S6K/pS6 signaling and downregulation of pERK in both TT and MZ-CRC-1 cells. Metformin had no significant effects on pAKT in the cell lines examined. Metformin-inducible AMPK activation was noted only in TT cells. Treatment with AMPK inhibitor (compound C) or AMPK silencing did not prevent growth inhibitory effects of metformin in TT cells. Metformin had no effect on MTC cell migration but reduced the ability of cells to form multicellular spheroids in nonadherent conditions. Immunostaining of human MTC showed over-expression of cyclin D1 in all tumors compared with corresponding normal tissue. Activation of mTOR/p70S6K was detected in 8/14 (57.1%) examined tumors. Together, these findings indicate that growth inhibitory effects in MTC cells are associated with downregulation of both mTOR/6SK and pERK signaling pathways. Expression of metformin's molecular targets in human MTC cells suggests its potential utility for the treatment of MTC in patients.
Possibilities of Change in a World of Constraint
Authors: McCloud Sean
Published: March 2012

In this essay I will suggest that the work of Pierre Bourdieu, a scholar whose work seldom focused on religion, offers tools for thinking about personal and social change that can aid us in understanding religious conversion and deconversion. In Bourdieu we find ways to conceptualize change that are materially grounded and embodied. As a post-structuralist, Bourdieu refuses to reduce individual change and stasis to the machinations of hardened social structures that stand apart from human activity. At the same time, Bourdieu is a social theorist who—in acknowledging the statistical regularities that demonstrate the reproduction of social inequalities—also avoids simplistic conceptions of human subjectivity that imagines autonomous individuals who possess some magical spark of free will to stand outside all external compulsions and rationally choose their life trajectories. For those interested in mapping the possibilities of change in a world of constraint, Bourdieu offers some useful starting points.
Bourdieu, Religion and Pluralistic Societies
Authors: Kühle Lene
Published: March 2012

It is widely recognised that the theory of practise of French sociologist Pierre Bourdieu may provide insights for the study of religion due to its general importance for social sciences and humanities in general. When it comes to Bourdieu's specific work on religion and in particular his concept of the religious field, scholars have been less enthusiastic in particular in relation to religion in complex societies. This article argues however that Bourdieu's work on the religious field may have been rejected prematurely, and that it may provide a frutile point of departure for studies of religion in pluralistic societies.
Descrição anatômica do terço proximal da artéria circunflexa femoral medial: estudo em cadáver
Authors: Freitas Anderson , Aires Helder Nogueira , Pansiere Saulo Teixeira , Souto Diogo de Macedo , Costa Mônica Meireles
Published: March 2012

OBJETIVO: Descrever através de estudo em cadáver a disposição anatômica do terço proximal da artéria cincunflexa femoral medial (ACFM). MÉTODOS: Foi avaliada a disposição anatômica do terço proximal da ACFM, através de dissecção em 12 quadris de cadáver, que após terem sua altura aferida em metros (M), foram determinados alguns parâmetros: Ângulo de lateralização da ACFM (Â), Profundidade da ACFM em relação a origem superomedial do músculo quadrado femoral (P), distância da ACFM em relação a inserção superolateral do músculo quadrado femoral (D). RESULTADOS: Quando comparamos a média dos parâmetros entre os sexos notamos: Masculino Â= 43.6 graus, feminino Â= 38.3 graus. Masculino D= 6mm, feminino D= 9.5mm. Masculino P= 20.8 mm, feminino P= 18.3mm. A média dos parametros Â e P são menores no sexo feminino porém o parâmetro D no sexo feminino é maior. CONCLUSÃO: Devemos ter como parâmetro superficial de segurança para o terço proximal da ACFM o ponto de inserção superolateral do músculo quadrado femoral. Que o parâmetro D da ACFM no sexo feminino é maior do que no sexo masculino. Que desinserir o músculo quadrado femoral em sua origem no ísquio pode oferecer maior segurança a ACFM do que faze-lo em sua inserção femural. Nível de evidência IV, série de casos.
Desordens musculoesqueléticas em violinistas e violistas profissionais: revisão sistemática
Authors: Moraes Geraldo Fabiano de Souza , Antunes Adriana Papini
Published: March 2012

Devido à alta demanda física e psicológica de trabalho, os músicos possuem grande risco de desenvolver uma variedade de problemas de saúde. As maiores causas de desordens musculoesqueléticas observadas em instrumentistas são excesso de uso, compressão nervosa e distonia focal. O objetivo deste artigo é identificar as desordens musculoesqueléticas que acometem com maior freqüência os violinistas e violistas profissionais. Foram lidos 50 artigos, desses, 24 foram utilizados. A escala PEDro foi utilizada para atestar a qualidade dos artigos. A definição dos fatores de risco pode ajudar na elaboração de programas de prevenção. Tocar instrumentos musicais envolve combinação de ações, incluindo movimentos rápidos, repetitivos e complicados das mãos e dedos. As cadeiras não oferecem outra opção senão a adaptação do corpo frente às exigências posturais. Para atingir destreza necessária para se tornar um músico de alto nível, são necessárias muitas horas de treinamento e aperfeiçoamento. O pescoço, ombro e a articulação temporomandibular são os mais afetados devido à posição prolongada de flexão da cabeça e ombro para segurar o violino, cotovelo e dedos também são alvos de desordens. É necessário alertar aos músicos de como são os sintomas iniciais para evitar que o distúrbio se agrave. Nível de Evidência I, Centro de Medicina baseada em Evidência, Oxford, Reino Unido.
Proposta para o desenvolvimento de taxonomias em portais corporativos
Authors: Vital Luciane Paula , Café Ligia
Published: March 2012

O trabalho pretende, respaldado teórica e metodologicamente pelas áreas da Classificação, Indexação, Linguística e Documentação, apresentar uma proposta de desenvolvimento de taxonomias. A taxonomia tem como proposição classificar e ordenar as informações em áreas específicas do conhecimento, como apoio à gestão, tanto da informação quanto do conhecimento. A pesquisa toma por base a análise de práticas de elaboração de taxonomia identificadas na literatura. Trata, na primeira parte, da construção da taxonomia, apresentando seu desenvolvimento pautado em cinco etapas. A segunda parte é dedicada à aplicação da taxonomia na representação da informação e organização dos documentos recuperados. Apesar das recomendações objetivarem o desenvolvimento de taxonomias no ambiente corporativo, suas indicações podem ser aplicadas a qualquer ambiente, realizando-se as devidas adaptações. Podemos constatar que a taxonomia trabalha os conceitos básicos da classificação aplicados ao ambiente digital.
Imagem e percepção humana: alternativa aplicada na classificação da literatura infantojuvenil de uma biblioteca escolar
Authors: Ramos Clériston Ribeiro , Dziekaniak Gisele Vasconcelos , Santiago Vanessa Dias , Munhoz Deise Parula
Published: March 2012

Esta pesquisa foi baseada no trabalho de Miranda; Poméia; Bueno (2004), o qual defende que fatores culturais e a faixa etária dos alunos são questões que influenciam na percepção humana, e entende que algumas imagens são convencionalmente designadas para diferentes culturas (como a norte-americana e a brasileira). A presente proposta não teve a pretensão de substituir as notações utilizadas para a classificação de assuntos em bibliotecas, amplamente difundidas (notações numéricas da CDD, CDU, etc.), mas sim, sugerir o que esta pesquisa denomina de "rotulação" destes assuntos através de imagens, para que melhor possam representá-los. Acredita-se que o objetivo da pesquisa foi alcançado: ordenamento mais claro dos materiais da biblioteca. Sugere-se o desenvolvimento desse sistema de imagens de classificação como forma alternativa de organização de bibliotecas contendo, em seu acervo literatura infantojuvenil.
Mobile banking como novo canal de disseminação de informações e disponibilização de serviços: um teste da teoria do comportamento planejado decomposto
Authors: Santos Deborah Oliveira , Veiga Ricardo Teixeira , Souza Sarah Ituassú
Published: March 2012

Investigou-se os antecedentes atitudinais da intenção de uso do mobile banking por clientes bancários, adotando-se a teoria do Comportamento Planejado Decomposto como referencial teórico. Na fase conclusiva da pesquisa, com 515 respondentes, aplicou-se a modelagem de equações estruturais. O modelo teórico foi sustentado empiricamente, porém necessita de aperfeiçoamentos. Cerca de 74% da variação na intenção de uso do mobile banking foi explicada pelo modelo, em que o construto segurança foi acrescentado.
Valores referenciais da eletromiografia de músculos envolvidos na deglutição: uma revisão sistemática
Authors: Belo Luciana Rodrigues , Coriolano Maria das Graças Wanderley de Sales , Menezes Danielle Carneiro de , Lins Otávio Gomes
Published: March 2012

TEMA: normalidade da eletromiografia de superfície de músculos envolvidos na deglutição. OBJETIVO: investigar se a literatura aponta valores referenciais de normalidade para a duração, amplitude e características dos eletromiogramas dos músculos envolvidos na deglutição (orbicular da boca, masseter, músculos da região supra-hióidea e músculos da região infra-hióidea cobertos pelo músculo platisma). CONCLUSÃO: a busca resultou em 33 referências, das quais somente cinco enquadraram-se nos critérios de inclusão. Apenas uma referência foi classificada com um bom nível de qualidade pela escala de Jadad com modificações. Os artigos selecionados podem não apontar valores referenciais confiáveis principalmente para a amplitude e morfologia da eletromiografia de superfície, pois utilizaram uma freqüência de amostragem inadequada para os registros eletromiográficos o que potencializa a obtenção de dados distorcidos da atividade muscular. Tendo em vista a variabilidade inter e entre os sujeitos, a literatura sugere a realização de técnicas de normalização do sinal eletromiográfico.
Espalhamento e estados ligados em potenciais localizados
Authors: Castro A.S. de
Published: March 2012

Apresenta-se um formalismo simples que permite explorar o espalhamento quântico e os possíveis estados ligados em um potencial simétrico localizado de forma arbitrária de um modo unificado. A barreira e o poço quadrados simétricos são utilizados como ilustração do método.
Física e pintura: dimensões de uma relação e suas potencialidades no ensino de física
Authors: Gomes Tiago Carneiro , Giorgi Cristiano Amaral Garboggini Di , Raboni Paulo César de Almeida
Published: March 2012

Neste artigo são discutidas possibilidades de uso das relações entre a física e a pintura no Ensino Médio. A partir das propostas de ensino oficiais, que já incorporam a necessidade de rever a abordagem usual dos conceitos da física, e de propostas de outros autores que afirmam a necessidade de dar outros sentidos aos conceitos físicos, mostramos como o desenvolvimento da física e da pintura indicam aproximações, e de como estas podem contribuir para a compreensão de conceitos dessa e de outras disciplinas, bem como para a compreensão da realidade em seu sentido mais amplo.
Radiation Model for Row Crops: II. Model Evaluation
Authors: Colaizzi P. D. , Schwartz R. C. , Evett S. R. , Howell T. A. , Gowda P. H. , Tolk J. A.
Published: March 2012

Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and methods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops having sparse to full vegetation cover. The radiation model was combined with geometric view factors based on elliptical hedgerows that account for the spatial distribution of row crop vegetation, and this approach was compared with the more commonly used clumping index approach. Irradiance measurements included transmitted and reflected visible and shortwave, outgoing longwave, and total net radiation. The model used optimized parameters for corn (Zea mays L.), grain sorghum [Sorghum bicolor (L.) Moench], and cotton (Gossypium hirsutum L.). The elliptical hedgerow and clumping index approaches resulted in similar model agreement; however, the former resulted in up to 7.3 W m−2 smaller RMSE and up to 7.5 W m−2 smaller mean bias error compared with the latter. Both approaches resulted in similar model sensitivities to inputs, which varied ±25%. Calculated shortwave irradiance fluxes were most sensitive to leaf area index (LAI; –3.25), canopy width (–1.94), ellipsoid leaf angle parameter (–0.77), and visible leaf absorption (–5.54) when LAI = 2.95 m2 m−2, and visible soil reflectance (0.89) when LAI = 0.21 m2 m−2. Calculated outgoing longwave irradiance and net radiation were most sensitive to the soil directional brightness temperature (0.55 and –0.61, respectively) when LAI = 0.21 m2 m−2.
The Mechanism for Weed Suppression by a Forage Radish Cover Crop
Authors: Lawley Yvonne E. , Teasdale John R. , Weil Ray R.
Published: March 2012

Little is known about the mechanism of winter annual weed suppression by forage radish (Raphanus sativus L. variety longipinnatus) winter cover crops. Previous studies suggest that allelopathy from decomposing residue and competition due to rapid canopy development contribute to weed suppression by other Brassica cover crops. Four contrasting experimental approaches were used to identify the mechanism of weed suppression by forage radish cover crops. Results of a field based cover crop residue‐transfer experiment supported the hypothesis that fall cover crop weed competition is the dominant mechanism of weed suppression following forage radish cover crops. A high level of early spring weed suppression was observed where forage radish grew in the fall regardless of whether residues were left in place or removed. In contrast, there was limited weed suppression in bare soil treatments that received additions of forage radish tissues. Bioassays using cover crop amended soil or aqueous extracts of cover crop tissues and amended soil did not reveal any allelopathic activity limiting seed germination or seedling establishment. In a field‐based weed seed bioassay, forage radish cover crops did not inhibit emergence of winter‐planted weed seeds relative to a no cover crop control. Forage radish amended soils stimulated seedling growth of lettuce (Lactuca sativa L.) in all types of bioassays. The results of the four experiments in this study point to a common conclusion that fall weed competition is the dominant mechanism for early spring weed suppression following forage radish winter cover crops.
Phosphorus and Potassium Fertilization Do Not Affect Soybean Storability
Authors: Krueger Keaton , Goggi A. Susana , Mullen Russell E. , Mallarino Antonio P.
Published: March 2012

Few studies have investigated the influence of P and K fertilization on soybean [Glycine max L. (Merr.)] seed storability. The objectives were to determine the effect of P and K fertilizer rates and seed storage environments on soybean seed quality and seed carry‐over potential. Seed lots were harvested from a long‐term P and K trial. The plants were grown on replicated plots fertilized with one of four rates of P or four rates of K (0, 28, 56, 112 kg P2O5 ha−1/0, 35, 70, 140 kg K2O ha−1) broadcast by hand in the fall. Seed samples were stored in four different storage environments: continuous climate controlled warehouse; continuous nonclimate controlled warehouse; nonclimate controlled warehouse and 1 mo at 12‐h alternating temperatures of 4.5° and 15.5°C; and nonclimate controlled warehouse and 2 mo at alternating temperatures, with the first month at 4.5° and 15.5°C and second month at 10°C and 32.2°C. Most seed lots stored under ideal conditions were below the recommended value of 95% germination and 80% vigor following 13 mo of storage. Seed storage environments that experienced high temperature (>20°C) and relative humidity (RH) (>80%) rapidly decreased in seed viability and vigor to unacceptable levels. Phosphorus and K fertilization did not improve seed storability, although higher rates of K fertilization increased seed survival in poor storage environments for a short time. Seed producers should not store soybean seed for two growing seasons, regardless of storage environment and P and K fertilization levels in the seed production field.
Spectral Estimates of Crop Residue Cover and Density for Standing and Flat Wheat Stubble
Authors: Aguilar Jonathan , Evans Robert , Vigil Merle , Daughtry Craig S. T.
Published: March 2012

Crop residue is important for erosion control, soil water storage, filling gaps in various agroecosystem‐based modeling, and sink for atmospheric carbon. The use of remote sensing technology provides a fast, objective, and efficient tool for measuring and managing this resource. The challenge is to distinguish the crop residue from the soil and effectively estimate the residue cover across a variety of landscapes. The objective of this study is to assess a select Landsat Thematic Mapper (TM) and hyperspectral‐based indices in estimating crop residue cover and amount for both standing and laid flat, and between two winter wheat (Triticum aestivum L.) harvest managements (i.e., stripper‐header and conventional header) and fallow following proso‐millet (Panicum miliaceum L.) plots. The primary plots were located in Colorado with additional plots in eastern Montana, Oregon, and Washington states. Data collected include hyperspectral scans, crop residue amount (by weight) and residue cover (by photo‐grid). Mean analyses, correlation tests, and spectral signature comparison show that the relative position of the crop residues affected the values of some remote sensing indices more than harvest management. Geographical location did not seem to influence the results. There was not enough evidence to support the use of these indices to accurately estimate the amount of residue. Hyperspectral data may deliver better estimates, but in its absence, the use of two or more of these datasets might improve the estimation of residue cover. This information will be useful in guiding analysis of remotely sensed data and in planning data acquisition programs for crop residue, which are essentially nonexistent at present.
Density Dependence Rather Than Maturity Determines Hybrid Selection in Dryland Maize Production
Authors: Berzsenyi Z. , Tokatlidis I. S.
Published: March 2012

For dryland maize (Zea mays L.) production, it is believed that optimal hybrid choice pertains to time required to reach maturity. In our study, the main hypothesis was that density independence (ability of the hybrid to yield highly under both low and high density) is another key factor that deserves special consideration. To address the issue, field experimentation was conducted under rainfed conditions at Martonvásár, Hungary for 11 yr. Treatments consisted of four N fertilizer rates (0, 100, 200, and 300 kg ha−1), four plant population densities (3, 5, 7, and 9 plants m−2), and four hybrids (Mara, Norma, Gazda, and Maraton). Variation in precipitation contributed to considerable variability in grain yield, which ranged from 1.46 to 7.67 T ha−1. A positive relationship between optimum density and mean experimental yield indicated suitability of low and high plant populations for unfavorable and favorable seasons, respectively. Among hybrids, the mid‐season Norma and full‐season Maraton and Gazda hybrids were superior over the short‐season Mara. However, Maraton hybrid exhibited a wide range of optimum densities, and performed as a density‐independent hybrid. This characteristic enables hybrid planting at low density to meet requirements of the dry season and good utilization of occasional high rainfalls with less yield potential loss. This research indicated that breeding density‐independent hybrids help in maize production under dryland conditions.
Generalized Algorithm for Variable‐Rate Nitrogen Application in Cereal Grains
Authors: Solie John B. , Monroe A. Dean , Raun William R. , Stone Marvin L.
Published: March 2012

Many different mathematical algorithms have been developed and used in conjunction with commercial sensors for sensor‐based nutrient management. Several of the N algorithms have led to the precise mid‐season prediction of yields and calculation of sidedress N rates. The original Oklahoma State University (OSU) algorithm identified several limitations that were addressed in this study. Based on data analyses from more than 390 winter wheat (Triticum aestivum L.) and 200 corn (Zea mays L.) experiments and analyses of more than 100 N‐rich strips, a generalized algorithm (for both corn and wheat) was developed to estimate the optimum N application rate based on spectral measurements. The generalized model adjusts the yield calibration curve for growth stages and better predicts corn and wheat yields. The coefficients of determination of the generalized model explained 5 to 6% less of the model error than the individual regressed data for both crops. Mean absolute error (MAE) was approximately 0.9 Mg/ha greater with the generalized model than with the individually regressed model. The larger MAE with the OSU generalized model was due to sensitivity to location of the inflection point; however, this sensitivity did not impact the calculated fertilizer rates. The generalized model reported here using normalized difference vegetation index sensor measurements collected midseason can be used to apply fertilizer N with changing growth stage for both corn and wheat.
Critical Nitrogen Dilution Curve for Optimizing Nitrogen Management of Winter Wheat Production in the North China Plain
Authors: Yue Shanchao , Meng Qingfeng , Zhao Rongfang , Li Fei , Chen Xinping , Zhang Fusuo , Cui Zhenling
Published: March 2012

Investigating critical N concentration, that is, the minimum N concentration necessary to achieve maximum growth, provides insights into N nutrition and can serve as a guide to improving agricultural practices and regulations. Our objectives were to evaluate N dilution curves for deficient, optimal, and excess added N and to determine the critical N dilution curve for winter wheat (Triticum aestivum L.) in the North China Plain (NCP) based on 15 N fertilization experiments with three to six N fertilization rates. The N supplements significantly affected the N dilution curve, and increased N supply generally resulted in a greater N concentration. The critical N dilution curve for winter wheat was described by the equation nitrogen concentration (Nc) = 4.15 W–0.38 when aboveground biomass was between 1 and 10 Mg dry matter (DM) ha−1. When aboveground biomass was <1 Mg DM ha−1, the constant critical value Nc = 4.15% DM, which was independent of aboveground biomass. This curve was lower than that of winter wheat in France. This critical N dilution curve was validated through the nitrogen nutrition index (NNI) defined as the ratio between measured N concentration and critical Nc. The critical N dilution curve holds promise as an efficient tool for guiding N‐fertilization practices and regulations for winter wheat production in the NCP.
Effects of No‐Till on Yields as Influenced by Crop and Environmental Factors
Authors: Toliver Dustin K. , Larson James A. , Roberts Roland K. , English Burton C. , De La Torre Ugarte Daniel G. , West Tristram O.
Published: March 2012

This research evaluated differences in yields and associated downside risk from using no‐till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no‐till. Results indicated that mean yields for sorghum [Sorghum bicolor (L.) Moench] and wheat (Triticum aestivum L.) with no‐till were greater than with tillage. In addition, no‐till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no‐till on loamy soils. With the exception of corn (Zea mays L.) and cotton (Gossypium hirsutum L.) in the Southern Seaboard region, no‐till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no‐till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [Glycine max (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no‐till had larger downside yield risks than when produced with no‐till on loamy soils. The key findings of this study support the hypothesis that soil and climate factors impact no‐till yields relative to tillage yields and may be an important factor influencing risk and expected return and the adoption of the practice by farmers.
Selection of Rhizobia from Agronomic Legumes Grown in Semiarid Soils to be Employed as Bioinoculants
Authors: Ruiz‐Díez Beatriz , Fajardo Susana , Fernández‐Pascual Mercedes
Published: March 2012

The aim of this study was to select rhizobia from a collection previously created from nodulated legumes grown in semiarid environments to be used as bioinoculants. The selection was based on the analyses of symbiotic efficiency and molecular analyses. Twenty‐nine strains of rhizobia were evaluated. The symbiotic efficiency was tested by cross‐inoculations with 12 traditional cultivated legumes including pea (Pisum sativum L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.), vicias (Vicia spp.), clover (Trifolium spp.), alfalfa (Medicago sativa L.), and lupin (Lupinus spp.). The nodC gene was used as a symbiotic marker of host specificity for discriminating and consequently selecting between strains with similar growth values. This rendered 12 symbiotypes which were consistent with their hosts of origin. The 16S‐23S rDNA intergenic spacer region was successfully used for the validation of nodule occupancy revealing its potential for strain identification in nodulation studies. The strains showed variability in their nodulation patterns and the host range was strain‐specific. Some combinations were restrictive displaying nodulation only with their host plants, while it was found that 21 strains of Rhizobium leguminosarum bv. viceae and eight plant species of Fabeae tribe constituted one cross‐inoculation group. Nodule weight, as an indicator of infectiveness, and shoot dry weight, as an indicator of effectiveness, were the plant features employed to discriminate among strains with better symbiotic performance. These molecular and agronomic analyses allowed us to select specific native strains for each plant species and soil of origin. They could be employed in field inoculations trials using cultivars of agricultural legumes previously selected under typical Mediterranean conditions contributing to the development of sustainable agriculture.