bluuebunny/crossref_metadata_2025 huggingface dataset:
Attentional Effects with Superimposed Symbology: Implications for Head-up Displays (HUD)
Authors: Foyle David C. , McCann Robert S. , Sanford Beverly D. , Schwirzke Martin F.J.
Published: April 2008

Previous research has shown that the presence of head-up display (HUD) symbology containing altitude information improves altitude performance at the cost of terrain path performance, implying that these information sources may not be available for concurrent cognitive processing. In two flight simulation experiments, the influence of attentive field size on this concurrent processing limitation was evaluated. In Experiment 1, a superimposed digital altitude (i.e., HUD) indicator was presented at three distances from a flight-relevant ground track. A control condition eliminated the digital altitude indicator. Altitude symbology improved performance on the altitude maintenance task, but impaired performance on the ground track task only when directly superimposed. Experiment 2 tested a visual masking explanation of the performance trade-off. Irrelevant HUD information yielded identical results to the HUD absent condition, ruling out effects of visual masking. An explanation in which visual/spatial attention cannot be directed to both HUD information and terrain information simultaneously is proposed. The absence of a performance tradeoff when the HUD and the terrain information are not directly superimposed is attributed to a breaking of attentional tunneling on the HUD, possibly due to eye movements.
Highlighting with Flicker Some Basic Visual Search Considerations
Authors: Van Orden Karl F. , DiVita Joseph
Published: April 2008

Previous research has demonstrated that search times are reduced when flicker is used to highlight color coded symbols, but that flicker is not distracting when subjects must search for non-highlighted symbols. This prompted an examination of flicker and other stimulus dimensions in a conjunctive search paradigm. In all experiments, at least 15 subjects completed a minimum of 330 trials in which they indicated the presence or absence of target stimuli on a CRT display that contained either 8, 16 or 32 items. In Experiment 1, subjects searched for blue-steady or red-flickering (5.6 Hz) circular targets among blue-flickering and red-steady distractors. Blue-steady targets produced a more efficient search rate (11.6 msec/item) than red-flickering targets (19.3 msec/item). In Experiment 2, a conjunction of flicker and size (large and small filled circles) yielded the opposite results; the search performance for large-flickering targets was unequivocally parallel. In Experiment 3, conjunctions of form and flicker yielded highly serial search performance. The findings are consistent with the response properties of parvo and magnocellular channels of the early visual system, and suggest that search is most efficient when one of these channels can be filtered completely.
Multimodal Measures of the Energetic Demands of Information Processing in a Suboptimal Environment
Authors: Ryan Arthur M. , Backs Richard W.
Published: April 2008

Twenty-four male volunteers participated in a study in which the feature extraction and response choice information processing stages of a visual memory task and the environment in which the task was performed were manipulated in order to assess the specificity of energetic demands. Ambient auditory noise was a state variable that was predicted to directly affect the energetic mechanism supporting the feature extraction processing stage and to indirectly affect the energetic mechanism supporting the response choice processing stage. Several classes of dependent measures were taken including performance, cardiovascular, pulmonary, and metabolic in order to isolate effects upon energetic mechanisms. The present study did not support the proposition of multiple energetic mechanisms. Instead, the combination of a single variable-capacity energetic resource with a flexible allocation policy to the processing stages was a better fit to the results.
Eye-Gaze Control of the Computer Interface: Discrimination of Zoom Intent
Authors: Goldberg Joseph H. , Schryver Jack C.
Published: April 2008

An analysis methodology and associated experiment were developed to assess whether definable and repeatable signatures of eye-gaze characteristics are evident, preceding a decision to zoom-in, zoom-out, or not to zoom at a computer interface. This user intent discrimination procedure can have broad application in disability aids and telerobotic control. Eye-gaze was collected from 10 subjects in a controlled experiment, requiring zoom decisions. The eye-gaze data were clustered, then fed into a multiple discriminant analysis (MDA) for optimal definition of heuristics separating the zoom-in, zoom-out, and no-zoom conditions. Confusion matrix analyses showed that a number of variable combinations classified at a statistically significant level, but practical significance was more difficult to establish. Composite contour plots demonstrated the regions in parameter space consistently assigned by the MDA to unique zoom conditions. Peak classification occurred at about 1200-1600 msec. Improvements in the methodology to achieve practical real-time zoom control are considered.
Attentional Guidance in Visual Attention
Authors: Todd Steven , Kramer Arthur F.
Published: April 2008

Earlier research has shown that a task-irrelevant sudden onset of an object will capture or draw an observer's visual attention to that object's location (e.g., Yantis & Jonides, 1984). In the four experiments reported here, we explore the question of whether task-irrelevant properties other than sudden-onset may capture attention. Our results suggest that a uniquely colored or luminous object, as well as an irrelevant boundary, may indeed capture or guide attention, though apparently to a lesser degree than a sudden onset: it appears that the degree of attentional capture is dependent on the relative salience of the varied, irrelevant dimension. Whereas a sudden onset is very salient, a uniquely colored object, for example, is only salient relative to the other objects within view, both to the degree that it is different in hue from its neighbors and the number of neighbors from which it differs. The relationship of these findings to work in the fields of visual momentum and visual scanning is noted.
Vigilance: Where Has All the Workload Gone?
Authors: Sawin David A. , Scerbo Mark W.
Published: April 2008

The present study explored whether instructions given to subjects at the outset of a vigilance experiment impact their ratings of frustration and workload. The present task consisted of monitoring a video display terminal (VDT) of uniform color for 30 min. Subjects were asked to respond to occasional 3 ms “flickers” to a different color. Half of the subjects were told to relax by focusing on the display, but to respond to any flickers observed. The remaining subjects were given traditional vigilance instructions emphasizing the importance of detecting as many “critical signals” or flickers as possible. Before and after the vigil, subjects completed the NASA Task Load Index (TLX; Hart and Staveland, 1988) which measured the subjective workload for the vigil. Hits and false alarm data were recorded for each 10 min period within the 30 min vigil. A significant reduction in mean number of hits was observed over the three periods for all subjects. A subsequent analysis showed that perceptual sensitivity also declined significantly over time. Performance, however, was not affected by instruction type. Subjects who received relaxation-emphasis instructions did report significantly lower workload and frustration for the vigil than those receiving detection-emphasis instructions. These results indicate that much of what individuals find unpleasant about participating in vigilance experiments may lie with the expectations outlined in the initial instructions.
Some Limitations on the Use of the Forced-Choice Technique for Target Detection Research
Authors: Salafia W. Ronald , DaRos Dino A.
Published: April 2008

The forced-choice (FC) format is used for stimulus presentation and performance assessment in a variety of tasks, including target detection and acquisition, tasks that involve primarily vigilance, monitoring, and search (VMS) behaviors. Laboratory experiments, comparison investigations, and system performance assessments have been reported in the literature with numerous claims about FC procedures, including that they lead to simplification of data handling and increased cost-effectiveness. The present report takes issue with these and other claims, as well as with the underlying assumption that FC procedures are interchangeable with continuous-search procedures, when applied to VMS tasks.
Guided Search 2.0: The Upgrade
Authors: Wolfe Jeremy M
Published: April 2008

This paper provides a brief review of the Guided Search model of human visual search behavior. In the model, parallel processes analyze a limited number of basic visual features across large portions of the visual field. The output of these processes can be used to guide attention in the deployment of the limited-capacity processes that are capable of identifying more complex visual targets.
The Role of Feedback in Learning Spatially Incompatible Choice Reaction Tasks: Does it Have one?
Authors: Dutta Addie , Proctor Robert W.
Published: April 2008

Stimulus-response compatibility effects have been shown to persist even after extended practice. In the present study, two experiments were conducted to see if the effects persist when knowledge of results that allows subjects to set performance goals is provided. In the first experiment, summary feedback about mean accuracy and mean reaction time was provided after each block of 40 trials of practice in a two-choice spatial compatibility task. Subjects practiced the task for 2,400 trials, yet the compatibility effect was not eliminated. Compared to previous experiments, reaction times were faster overall, but the degree of change was the same for both compatible and incompatible assignments. In the second experiment, a response deadline was imposed on each trial. If the subject did not respond within the time limit, which was reduced as the experiment progressed, auditory feedback was presented. Summary feedback was also presented as in Experiment 1. Again, 2,400 trials of practice reduced but did not eliminate the compatibility effect. The greater reduction in the difference in reaction times for compatible and incompatible assignments, relative to other experiments, could be attributed to speed-accuracy tradeoff. The results indicate that the persistence of stimulus-response compatibility effects with extended practice is not due to poorer motivation to perform with the incompatible assignment. The results suggest that training will be insufficient to overcome difficulties in performance resulting from spatially incompatible assignments.
An Endogenous Glutamatergic Drive onto Somatic Motoneurons Contributes to the Stereotypical Pattern of Muscle Tone across the Sleep–Wake Cycle
Authors: Burgess Christian , Lai Diane , Siegel Jerome , Peever John
Published: April 2008

Skeletal muscle tone is modulated in a stereotypical pattern across the sleep–wake cycle. Abnormalities in this modulation contribute to most of the major sleep disorders; therefore, characterizing the neurochemical substrate responsible for transmitting a sleep–wake drive to somatic motoneurons needs to be determined. Glutamate is an excitatory neurotransmitter that modulates motoneuron excitability; however, its role in regulating motoneuron excitability and muscle tone during natural sleep–wake behaviors is unknown. Therefore, we used reverse-microdialysis, electrophysiology, pharmacological, and histological methods to determine how changes in glutamatergic neurotransmission within the trigeminal motor pool contribute to the sleep–wake pattern of masseter muscle tone in behaving rats. We found that blockade of non-NMDA and NMDA glutamate receptors (via CNQX andd-AP-5) on trigeminal motoneurons reduced waking masseter tone to sleeping levels, indicating that masseter tone is maximal during alert waking because motoneurons are activated by an endogenous glutamatergic drive. This wake-related drive is switched off in non-rapid eye movement (NREM) sleep, and this contributes to the suppression of muscle tone during this state. We also show that a functional glutamatergic drive generates the muscle twitches that characterize phasic rapid-eye movement (REM) sleep. However, loss of a waking glutamatergic drive is not sufficient for triggering the motor atonia that characterizes REM sleep because potent activation of either AMPA or NMDA receptors on trigeminal motoneurons was unable to reverse REM atonia. We conclude that an endogenous glutamatergic drive onto somatic motoneurons contributes to the stereotypical pattern of muscle tone during wakefulness, NREM sleep, and phasic REM sleep but not during tonic REM sleep.
CD36/Fatty Acid Translocase, An Inflammatory Mediator, Is Involved in Hyperlipidemia-Induced Exacerbation in Ischemic Brain Injury
Authors: Kim Eunhee , Tolhurst Aaron T. , Qin Lu Ye , Chen Xin-Yuan , Febbraio Maria , Cho Sunghee
Published: April 2008

Hyperlipidemia with accompanying increase in peripheral inflammation is a risk factor for stroke. The effect of excess lipids on stroke-induced injury and the mechanism by which lipid-mediated inflammatory responses contribute to stroke are not known. We investigated these uncertainties by subjecting normal and hyperlipidemic mice to transient middle cerebral artery occlusion, followed by measurement of stroke severity and inflammatory response. Infarct size, swelling, and lipid contents were significantly increased in the high-fat fed ApoE knock-out mice, as was the expression of the inflammatory mediators CD36 and monocyte chemoattractant protein 1 (MCP-1) in the brain and periphery. Furthermore, the hyperlipidemic mice exhibited numerous foam cells, a probable cause of increased swelling and postischemic inflammation, in the peri-infarct area. Genetic deletion ofcd36in the hyperlipidemic condition reduced proinflammatory chemokine/receptor and cytokines (MCP-1, CC chemokine receptor 2, and interleukins 1β and 6), in the brain 6 h after ischemia. The reduced proinflammatory response also resulted in smaller ischemic injury, less swelling, and fewer foam cells at 3 d after ischemia. The results show that hyperlipidemia-induced inflammation is a negative factor for stroke outcomes and indicate that downregulating CD36 may be an effective therapeutic strategy for reducing the impact of stroke in hyperlipidemic subjects.
Mitogen-Activated Protein Kinase Is a Functional Component of the Autonomous Circadian System in the Suprachiasmatic Nucleus
Authors: Akashi Makoto , Hayasaka Naoto , Yamazaki Shin , Node Koichi
Published: April 2008

The suprachiasmatic nucleus (SCN) is the master circadian pacemaker driving behavioral and physiological rhythms in mammals. Circadian activation of mitogen-activated protein kinase [MAPK; also known as ERK (extracellular signal-regulated kinase)] is observedin vivoin the SCN under constant darkness, although the biological significance of this remains unclear. To elucidate this question, we first examined whether MAPK was autonomously activated inex vivoSCN slices. Moreover, we investigated the effect of MAPK inhibition on circadian clock gene expression and neuronal firing rhythms using SCN-slice culture systems. We show herein that MAPK is autonomously activated in the SCN, and our data demonstrate that inhibition of the MAPK activity results in dampened rhythms and reduced basal levels in circadian clock gene expression at the SCN single-neuron level. Furthermore, MAPK inhibition attenuates autonomous circadian neuronal firing rhythms in the SCN. Thus, our data suggest that light-independent MAPK activity contributes to the robustness of the SCN autonomous circadian system.
Modeling of grain refinement: Part II. Effect of nucleant particles—TiB2 additions for aluminum
Authors: Yao X. , McDonald S.D. , Dahle A.K. , Davidson C.J. , StJohn D.H.
Published: April 2008

Following the discussion of modeling grain refinement in Part I, [X. Yao, et al., J. Mater. Res.23(5), 1282, the effect of Al–Ti–B master alloy additions on grain formation in commercial-purity (CP) aluminum was investigated. The characteristics of the addition particles as applicable to the model are presented. The effect of adding TiB2 particles, the introduction of extra particles by reactions in the melt, and the effect of adding extra solute Ti are all modeled. The distribution of the potential particles and its effect on grain formation was also modeled to establish the relationship between the grain size and microstructure morphology and the additive characteristics. The calculated results are comparable with experimental data. Accordingly, possible mechanisms of grain refinement with Al–Ti–B refiners were proposed.
Surface and optical property modifications of self-assembled CdTe/ZnTe quantum dots caused by thermal treatment
Authors: Lee H.S. , Park H.L. , Kim T.W.
Published: April 2008

Atomic force microscopy images showed that the size of the CdTe quantum dots (QDs) slightly increased with increasing annealing temperature up to 350 °C. Photoluminescence spectra showed that the excitonic peak corresponding to the interband transition from the ground electronic subband to the ground heavy-hole band (E1–HH1) in the CdTe/ZnTe QDs annealed at 350 °C was shifted to lower energy compared with that in as-grown CdTe/ZnTe QDs. The full width at half-maximum of the E1–HH1 transition peak in the CdTe/ZnTe QDs annealed at 350 °C decreased resulting from the improvement of the crystallinity for the annealed CdTe QDs.
Scaffolding carbon nanotubes into single-molecule circuitry
Authors: Goldsmith Brett R. , Coroneus John G. , Lamboy Jorge A. , Weiss Gregory A. , Collins Philip G.
Published: April 2008

While nanowires and nanotubes have been shown to be electrically sensitive to various chemicals, not enough is known about the underlying mechanisms to control or tailor this sensitivity. By limiting the chemically sensitive region of a nanostructure to a single binding site, single molecule precision can be obtained to study the chemoresistive response. We have developed techniques using single-walled- carbon-nanotube (SWCNT) circuits that enable single-site experimentation and illuminate the dynamics of chemical interactions. Discrete changes in the circuit conductance reveal chemical processes happening in real-time and allow SWCNT sidewalls to be deterministically broken, reformed, and conjugated to target species.
Time-dependent mechanical characterization of poly(2-hydroxyethyl methacrylate) hydrogels using nanoindentation and unconfined compression
Authors: Kaufman Jessica D. , Miller Gregory J. , Morgan Elise F. , Klapperich Catherine M.
Published: April 2008

Hydrogels pose unique challenges to nanoindentation including sample preparation, control of experimental parameters, and limitations imposed by mechanical testing instruments and data analysis originally intended for harder materials. The artifacts that occur during nanoindentation of hydrated samples have been described, but the material properties obtained from hydrated nanoindentation have not yet been related to the material properties obtained from macroscale testing. To evaluate the best method for correlating results from microscale and macroscale tests of soft materials, nanoindentation and unconfined compression stress-relaxation tests were performed on poly-2-hydroxyethyl methacrylate (pHEMA) hydrogels with a range of cross-linker concentrations. The nanoindentation data were analyzed with the Oliver–Pharr elastic model and the Maxwell–Wiechert (j = 2) viscoelastic model. The unconfined compression data were analyzed with the Maxwell–Wiechert model. This viscoelastic model provided an excellent fit for the stress-relaxation curves from both tests. The time constants from nanoindentation and unconfined compression were significantly different, and we propose that these differences are due to differences in equilibration time between the microscale and macroscale experiments and in sample geometry. The Maxwell–Wiechert equilibrium modulus provided the best agreement between nanoindentation and unconfined compression. Also, both nanoindentation analyses showed an increase in modulus with each increasing cross-linker concentration, validating that nanoindentation can discriminate between similar, low-modulus, hydrated samples.
Funções de pedotransferência para as curvas de retenção de água e de resistência do solo à penetração
Authors: Silva Álvaro Pires da , Tormena Cássio Antonio , Fidalski Jonez , Imhoff Silvia
Published: April 2008

Funções de Pedotransferência (FPT) são ferramentas úteis para estimar, a partir de características inerentes ao solo, propriedades físicas deste, como a curva de retenção de água do solo (CRA) e a curva de resistência à penetração (CRP). A maioria dos trabalhos na literatura reporta FPT para estimar apenas a CRA. Um importante e necessário avanço nessa área de pesquisa seria o desenvolvimento de FPT para estimar a CRA e a CRP simultaneamente, objetivo deste trabalho. Uma área com solos que apresentam grande variação de textura foi selecionada; nelas 180 amostras foram obtidas para medir a CRA, a CRP, a densidade do solo, a análise granulométrica e o teor de C orgânico. A CRA e a CRP foram estimadas com sucesso, com coeficiente de determinação (R² > 0,9). O teor de argila foi a variável mais importante na definição das FPT, e o seu efeito na CRA e CRP foi demonstrado.
Índice relativo de clorofila e o estado nutricional em nitrogênio durante o ciclo do cafeeiro fertirrigado
Authors: Godoy Leandro Jose Grava de , Santos Thiago da Silva , Villas Bôas Roberto Lyra , Leite Júnior João Batista
Published: April 2008

O clorofilômetro (SPAD-502, Minolta) é um aparelho portátil que permite obtenção do índice relativo de clorofila (IRC) de modo simples, rápido e não destrutivo no próprio campo, o qual se correlaciona com a concentração de N em várias culturas, e que pode tornar mais rápida a correção de deficiência, otimizando a utilização da fertirrigação. Objetivou-se com este trabalho verificar se o IRC pode ser indicativo do estado nutricional em N, podendo auxiliar no ajuste da fertirrigação nitrogenada durante o ciclo do cafeeiro. O experimento foi desenvolvido em Botucatu, SP, em área com cafeeiros do cultivar Catuaí Vermelho, com dois anos, no espaçamento de 2,5 x 0,8 m e irrigado por gotejamento. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, aplicando-se um tratamento sem adubação, mas com irrigação, e mais quatro tratamentos utilizando fertirrigação com 33, 66, 100 e 133 % da dose de N recomendada, parcelada semanalmente (52,8; 105,6; 160,0; e 212,7 kg ha-1, respectivamente). O IRC aumentou linearmente com as doses de N, e a produtividade correlacionou-se significativamente com o IRC, do florescimento até a colheita, porém não com a concentração de N foliar. Os IRCs nos cafeeiros com maior produtividade foram de 81,5 a 83,2 (florescimento e início de expansão dos frutos), de 76,2 a 78,3 (expansão dos frutos), de 68,3 a 69,8 (início da granação), de 64,0 a 65,9 (na granação) e de 61,7 a 62,7 unidades SPAD (na maturação). O clorofilômetro pode ser utilizado para definir a probabilidade de resposta ao N no decorrer do ciclo do cafeeiro.
Estoque de carbono orgânico no solo e emissões de dióxido de carbono influenciadas por sistemas de manejo no sul do Brasil
Authors: Costa Falberni de Souza , Bayer Cimélio , Zanatta Josiléia Acordi , Mielniczuk João
Published: April 2008

O C fotossintetizado adicionado ao solo pelos resíduos vegetais (C-resíduo), as emissões de C na forma de dióxido de carbono (C-CO2) e o estoque de C orgânico do solo (C-solo) são componentes do ciclo deste elemento no sistema solo-planta-atmosfera. O efeito de práticas de manejo de solo sobre esses componentes necessita de melhor entendimento, visando à identificação de um sistema com potencial de reter C atmosférico no solo e contribuir para a mitigação do aquecimento global. Neste estudo, as emissões de C-CO2, o estoque de C e as adições de C pelos resíduos vegetais foram avaliados em experimento de longa duração (18 anos), localizado em Eldorado do Sul (RS). O quociente C-CO2/(C-resíduo + C-solo) foi proposto como índice da capacidade de sistemas de preparo e de cultura em conservar C no solo (ICC). A emissão de C-CO2 foi medida durante 17 meses; a quantidade de C-resíduo foi estimada com base em amostragens da massa de plantas de cobertura de inverno e no índice de colheita do milho; e o estoque de C-solo, avaliado na camada de 0-0,2 m do solo submetido aos sistemas de preparo convencional (PC) e plantio direto (PD), associados às sucessões de aveia (Avena strigosa Schreb)/milho (Zea mays L.) (A/M) e ervilhaca comum (Vicia sativa L.)/milho (E/M). Com objetivo de avaliar a relação das emissões de C-CO2 com fatores ambientais, foram monitoradas a temperatura a 0,05 m de profundidade e a umidade gravimétrica do solo nas camadas de 0-0,05; 0,05-0,1; e 0,1-0,2 m. Em comparação ao estoque de C-solo no início do experimento (33,4 t ha-1), o balanço foi negativo no solo em PC (-0,31 t ha-1 ano-1 no A/M e -0,10 t ha-1 ano-1 no E/M) e positivo no solo em PD (0,15 t ha-1 ano-1 ) apenas quando associado ao sistema E/M, o qual apresentou maior aporte de resíduos. As taxas mensais médias das emissões variaram entre 0,27 g m-2 de C-CO2 no inverno (média das temperaturas mínimas = 8 °C) e 1,36 g m-2 de C-CO2 no verão (média das temperaturas máximas = 38º C), que se relacionaram com a temperatura do solo (r > 0,85). A emissão total de C-CO2 no período variou entre 3,6 e 4,0 t ha-1 de C-CO2, não tendo sido verificada diferença significativa entre os sistemas de preparo de solo e de cultura. Entretanto, o ICC evidenciou que o potencial dos sistemas de manejo em conservar C no solo aumentou na ordem PC A/M < PC E/M < PD A/M < PD E/M. As condições menos oxidativas contribuíram para o balanço positivo de C no solo em plantio direto, característica que é potencializada pela utilização de sistemas de cultura com leguminosas como plantas de cobertura, que favorecem o acúmulo de C no solo por permitirem maior produção de massa das gramíneas cultivadas em sucessão, devido ao fornecimento de N.
Recuperação de um solo degradado com a aplicação de adubos verdes e lodo de esgoto
Authors: Kitamura Aline Emy , Alves Marlene Cristina , Suzuki Luiz Gustavo Akihiro Sanches , Paz Gonzalez Antonio
Published: April 2008

A utilização incorreta dos solos vem causando alterações neles, tornando-os cada vez menos produtivos, aumentando as áreas com solos degradados. O presente trabalho teve por objetivos estudar ações para acelerar a formação do horizonte A de um Latossolo Vermelho degradado, via uso de adubos verdes, lodo de esgoto e cultivo de uma espécie arbórea nativa de Cerrado, e selecionar indicadores para detectar alterações da camada superficial do solo. O monitoramento das alterações do solo foi realizado anualmente. O delineamento experimental foi o de blocos casualizados com seis tratamentos, em cinco repetições. Os tratamentos foram: testemunha - solo exposto (sem manejo); vegetação nativa (Cerrado); espécie arbórea Astronium fraxinifolium; Astronium fraxinifolium + Canavalia ensiformis; Astronium fraxinifolium + Raphanus sativus; e Astronium fraxinifolium + Brachiaria decumbens + lodo de esgoto (60 t ha-1). Avaliou-se no solo: porosidade, densidade do solo, cátions trocáveis, pH, acidez potencial (H + Al), soma de bases (SB), saturação por bases (V), CTC e macrorganismos. Nos adubos verdes, foi avaliada a massa seca e, para a espécie arbórea, a altura e o diâmetro de caule. A mobilização do solo e a mobilização mais a adubação verde e o lodo de esgoto estão recuperando as propriedades do solo degradado, com comportamento semelhante entre elas após um ano de adoção. O melhor indicador físico das alterações do solo foi sua densidade. Os tratamentos adotados são semelhantes quanto à população de macrorganismos do solo e contribuindo positivamente para recuperação da macrofauna. A presença de larva e besouro foi indicadora da melhoria da macrofauna do solo.
Modelo digital de elevação na caracterização de solos desenvolvidos de basalto e material arenítico
Authors: Sousa Junior José Geraldo de Abreu , Demattê José Alexandre M.
Published: April 2008

Os levantamentos de solos são na maioria antigos e pouco detalhados, geralmente nos níveis exploratório e de reconhecimento. Isso pode ser explicado pelo fato de que o método tradicional de levantamento de solos é lento e caro, requerendo grande número de observações de campo. Assim, o presente trabalho teve como objetivo caracterizar unidades de mapeamento de solos das regiões de Ibaté e São Carlos, SP, desenvolvidos de materiais basálticos e areníticos em função da declividade e altitudes correspondentes, com base em modelo digital de elevação (MDE). Primeiramente, foi feito um mapa de solos semidetalhado pelo método tradicional. Posteriormente, utilizando-se curvas de nível da região, foi elaborado o MDE, do qual foram extraídos mapas com diferentes classes de declividade e elevação. Por meio da tabulação cruzada, foi determinada a incidência de cada solo nas respectivas classes de declives e altitudes. Cada solo apresentou comportamento diferenciado em relação às classes de declive. Contudo, nas faixas limítrofes de declividade pode ocorrer sobreposição de dois ou mais solos. Na referida região, o Latossolo Amarelo encontra-se predominantemente nas regiões mais altas e de relevo plano; entretanto, solos pouco intemperizados, como os Neossolos Litólicos, aparecem em diferentes faixas de declividade. Conclui-se que o conhecimento da distribuição dos solos no relevo é de grande importância, pois facilita a execução do levantamento de solos. O modelo de elevação apresenta semelhanças com o mapa de solos, podendo auxiliar na sua determinação. As variações de solo, no entanto, são mais complexas, não dispensando as observações de campo.
Identification of confounders in the association between self-reported diseases and symptoms and self-rated health in a group of factory workers
Authors: Höfelmann Doroteia Aparecida , Blank Nelson
Published: April 2008

Self-related health is an important predictor of morbidity and mortality, and much of its effect is influenced by the presence of chronic diseases and/or symptoms. The current study aimed to identify confounders in the association between reported chronic diseases and/or symptoms and self-rated health among workers at a metallurgical factory in Santa Catarina State, Brazil. The study design was cross-sectional, with a probabilistic sample of 482 workers. The information was obtained through a self-administered questionnaire and anthropometric measurements. Hierarchical multiple logistic regression models were adjusted. The response rate was 98.6% (n = 475), with 84.8% men, mostly employed on the factory floor (79.4%). Back pain was the most common complaint. The association between chronic diseases and self-rated health showed an odds ratio (OR) of 7.3 (95%CI: 3.7;14.5). After statistical modeling, psychosocial (-25.59%), socioeconomic (-9.29%), and occupational variables (10.54%) were identified as confounders between the outcome and chronic diseases and/or symptoms. The way diseases and/or symptoms act on self-rated health among workers transcends physical aspects.
Impacto da internação na prática do aleitamento materno em hospital pediátrico de Salvador, Bahia, Brasil
Authors: Souza Edna Lúcia , Silva Luciana Rodrigues , Sá Ana Carolina Souza , Bastos Clara Maia , Diniz Andrea Borges , Mendes Carlos Maurício Cardeal
Published: April 2008

Trata-se de estudo do tipo corte transversal que objetivou determinar a prevalência de aleitamento materno em lactentes menores de quatro meses, internados por infecção respiratória em um hospital de ensino de Salvador, Bahia, Brasil e descrever a influência da internação na prática da amamentação. As mães foram entrevistadas e os dados sobre alimentação foram obtidos através de ficha padronizada nas quais são registradas informações sobre as práticas alimentares durante a internação. Entre as 97 crianças incluídas, o aleitamento materno exclusivo foi verificado em 57,1%, sendo interrompido em 35,4% dos pacientes pelo uso de fórmulas lácteas. A média de duração da internação não se associou à introdução de fórmulas lácteas no hospital. Na análise bivariada, houve associação entre maior escolaridade materna e interrupção mais precoce da amamentação exclusiva e entre renda familiar mais baixa e interrupção mais precoce do aleitamento materno exclusivo. A prevalência de aleitamento materno exclusivo foi baixa e em 35,4% dos casos foi interrompido durante a internação hospitalar, possivelmente, por dificuldades de ordem física e pelo pequeno apoio da equipe de saúde no estímulo à manutenção da amamentação.
Aspectos climáticos em áreas de transmissão de hantavirose no Estado de São Paulo, Brasil
Authors: Donalisio Maria Rita , Vasconcelos Cíntia Honório , Pereira Luiz Eloy , Ávila Ana Maria H. , Katz Giselda
Published: April 2008

O objetivo deste trabalho foi investigar a distribuição espacial dos casos notificados de hantavirose (n = 80) no Estado de São Paulo, Brasil, de 1993 a 2005, e identificar os padrões climáticos locais nos anos de registro da doença. Foi utilizado o estimador de densidade de pontos de kernel que apontou maior concentração nas regiões de Ribeirão Preto, São Carlos, Franca, Tupi Paulista e Grande São Paulo. O aumento do número de casos no período sugere disseminação da doença, embora se considere o aumento da capacidade diagnóstica e maior sensibilidade do sistema de saúde. Registrou-se marcada sazonalidade da hantavirose nas áreas de cerrado, com padrão comum, isto é, maior incidência em meses com baixa pluviosidade, comparados com médias dos últimos quarenta anos. Esses períodos coincidem com épocas de maior disponibilidade de alimentos a roedores em cultura de grãos, cana e outros. A colheita e armazenamento desses grãos aumentam a exposição de populações humanas aos roedores. Indicadores climáticos em conjunto com variáveis ecológicas podem compor marcadores de risco de transmissão local a serem valorizados nas ações de vigilância epidemiológica e controle da doença.
Alta prevalencia de la infección por el virus de hepatitis B en la comunidad indígena Japreira, Estado Zulia, Venezuela
Authors: Monsalve-Castillo Francisca , Echevarría José Manuel , Atencio Ricardo , Suárez Anais , Estévez Jesús , Costa-León Luciana , Montiel Pilar , Molero Tania , Zambrano Mariana
Published: April 2008

A fin de conocer la prevalencia de la infección por el virus de hepatitis B (VHB) en la comunidad indígena Japreira, Venezuela, y determinar las pautas de su adquisición en función de la edad y sexo, se seleccionaron 149 individuos de un total de 300. Se detectó por métodos serológicos la presencia de anticuerpos totales del VHB (anti-HBc total), y en las positivas se investigó la presencia del antígeno de superficie (HBsAg) y del antígeno "e" del VHB (HBeAg). La prevalencia de anti-HBc total fue de 72,9% en el sexo femenino y 81,1% en el masculino, la prevalencia de HBsAg fue elevada (61,1%) en el sexo masculino, sólo cuatro de los portadores de HBsAg fueron positivos para HBeAg. Los resultados obtenidos indican un grado elevado de endemia para esta infección y que su diseminación comienza a temprana edad. El factor involucrado en la adquisición y diseminación del virus seria la vía sexual. Hacinamiento, contacto intercorpóreo con fluidos biológicos, prácticas sociales, y características de la cepa viral circulante podrían estar involucradas en la alta cronicidad observada en la comunidad indígena Japreira.
Investigação da trombose venosa na gravidez
Authors: Kalil Jorge Agle , Jovino Marco Antonio C. , Lima Marcelo Arriaga de , Kalil Renato , Magliari Maria Elisa Ruffolo , Di Santo Marcelo K.
Published: April 2008

CONTEXTO: A trombose venosa profunda (TVP) na gravidez é fator determinante no aumento da morbidade e da mortalidade maternofetal. Pode ocorrer na presença de trombofilias, por compressão da veia cava inferior, estase venosa ou alterações hormonais. OBJETIVOS: Analisar pacientes grávidas e no pós-parto imediato portadoras de TVP em membros inferiores, pesquisar as possíveis causas de trombofilia e realizar revisão de literatura. MÉTODOS: Foram analisadas gestantes e puérperas encaminhadas por ginecologistas e obstetras com quadro clínico suspeito de TVP, de janeiro de 2004 a novembro de 2006, período em que foram realizados 24.437 partos no Hospital e Maternidade São Luiz (HMSL), sendo 89% cesarianas, 7,5% partos normais e 3,5% fórceps. Do total de pacientes encaminhadas com quadro clínico sugestivo, foram realizados 42 diagnósticos clínicos de TVP em gestantes com idade entre 21 e 39 anos, confirmados por duplex scan venoso. Imediatamente antes da introdução da terapia anticoagulante, foram colhidos exames para pesquisa de trombofilia, os quais foram repetidos após o período de tratamento. RESULTADOS: Das 42 pacientes portadoras de TVP, 32 eram primigestas (três gemelares sem alterações trombofílicas, duas por fecundação in vitro), oito secundigestas e duas tercigestas. Em quatro pacientes, a TVP ocorreu no primeiro trimestre da gestação (9,5%); em 11, no segundo trimestre (26,2%); em 27, no terceiro trimestre (64,3%). Dos 42 casos de diagnóstico de TVP, 18 (42,8%) ocorreram nas veias infrapatelares. Houve um caso de tromboembolismo pulmonar (TEP) em paciente de 37 anos que havia realizado fecundação in vitro, com gestação gemelar, e TVP (ausência de trombofilia) diagnosticada após a cesariana. Das 42 pacientes, 16 (38,1%) tiveram a causa da TVP estabelecida, com prevalência de mutação heterozigótica do fator V de Leiden (FVL) em seis pacientes (14,2%), seguida pela síndrome antifosfolípide e outras. A maioria das pacientes foi tratada com heparina de baixo peso molecular. CONCLUSÃO: A TVP na gravidez, apesar de sua baixa freqüência, aumenta consideravelmente a morbidade maternofetal. A pesquisa de trombofilia deve ser realizada em casos selecionados, tais como antecedentes pessoais ou familiares de fenômenos trombóticos e/ou trombofilia. A gestação gemelar, a cesariana e a inseminação artificial também foram fatores predisponentes para a ocorrência de TVP.
Diagnóstico e tratamento de aneurisma da artéria isquiática persistente: relato de caso e revisão da literatura
Authors: Nunes Marco Antonio Prado , Ribeiro Roberto Maurício Ferreira , Aragão José Aderval , Reis Francisco Prado , Feitosa Vera Lúcia Correa
Published: April 2008

A persistência da artéria isquiática é uma variação anatômica rara cujo curso clínico é potencialmente grave, pois o diagnóstico ocorre quando já estão presentes complicações clínicas. Essas complicações advêm do fato de a parede da artéria isquiática ter uma tendência à degeneração ateromatosa com formação aneurismática, podendo evoluir para uma oclusão ou para um tromboembolismo. Este artigo relata o caso de um paciente do sexo feminino, com queixas de dor intensa secundária a compressão extrínseca do nervo isquiático pela dilatação aneurismática no membro inferior direito e pulsatilidade na nádega ipsilateral, apresentando uma massa hiperpulsátil nessa localização. Foi realizado exame angiográfico, que revelou persistência da artéria isquiática à direita, do tipo completo e com aneurisma. A paciente foi submetida a procedimento cirúrgico, sendo utilizada uma abordagem transglútea, e uma prótese de dácron terminoterminal foi interposta entre os colos proximal e distal do aneurisma. Os aspectos técnicos e revisão da literatura sobre o diagnóstico e a terapêutica dessa variação anatômica são discutidos neste trabalho.
Avaliação e tratamento fisioterápico na doença arterial obstrutiva periférica de membro superior: um estudo de caso
Authors: Pereira Danielle Aparecida Gomes , Custódio Marcelle Xavier , Carvalho João Paulo Ferreira de , Carvalho André Maurício Borges de , Cunha-Filho Inácio Teixeira da
Published: April 2008

O objetivo deste artigo é apresentar um estudo de caso em que se propõe um protocolo de avaliação e intervenção para uma paciente com claudicação de membro superior. Descrição do caso: mulher de 50 anos com 4 meses de evolução de quadro de obstrução de artéria braquial esquerda pós-cateterismo. Na avaliação com Doppler contínuo, observou-se presença de som monofásico em artérias radial e ulnar. No teste do cicloergômetro, a dor isquêmica iniciou aos 2 minutos e 30 segundos e atingiu o ponto máximo aos 9 minutos e 26 segundos. Foi realizado tratamento em cicloergômetro três vezes por semana durante 8 semanas. Após o tratamento, o tempo de teste em cicloergômetro aumentou: dor inicial aos 5 minutos e 7 segundos e máxima aos 18 minutos. A paciente relatou desaparecimento da cianose e melhora na realização de atividades de vida diária. O protocolo de avaliação proposto envolvendo medidas objetivas (cicloergômetro) e subjetivas (questionário SF-36 traduzido e validado em português) foi bem tolerado, tendo sido capaz de detectar alterações no estado funcional da paciente. As alterações detectadas no tempo de surgimento de dor inicial e de dor máxima podem ter acontecido de modo espontâneo, mas não se pode descartar que a intervenção possa, potencialmente, ser benéfica para indivíduos com claudicação de membros superiores. Os resultados observados neste estudo de caso avalizam futuros estudos envolvendo maior número de participantes.
Surgical importance of variant hepatic blood vessels: a case report
Authors: Pulakunta Thejodhar , Potu Bhagath Kumar , Gorantla Vasavi Rakesh , Vollala Venkata Ramana , Thomas Jency
Published: April 2008

This report describes a variation in blood vessels of the liver and abnormal entry of hepatic arteries into the liver found during routine dissection in an approximately 43-year-old male cadaver. An accessory hepatic artery arose from the superior mesenteric artery and entered the liver at the porta hepatis, whereas the proper hepatic artery was seen entering the left liver lobe at the fissure for ligamentum venosum. Clinical implications of such variation are discussed in the article.
Chemotherapy in Elderly Patients with Colorectal Cancer
Authors: Köhne Claus-Henning , Folprecht Gunnar , Goldberg Richard M. , Mitry Emmanuel , Rougier Philippe
Published: April 2008

Learning Objectives

After completing this course, the reader will be able to: Evaluate elderly CRC patients with regard to overall health, independence, and performance status using a comprehensive geriatric assessment.Assess the determinants for response to treatment and overall survival in elderly CRC patients who can be categorized as either fit, intermediate, or frail.Determine the optimal first-line chemotherapy regimen for the fit elderly polymedicated patient with CRC.

CME Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com

Significant advancements in chemotherapy for metastatic colorectal cancer (mCRC) have been achieved over the past decade, and the median overall survival duration is now close to 24 months with appropriate treatment. The most widely recommended chemotherapy regimens are based on the use of irinotecan or oxaliplatin in combination with 5-fluorouracil and leucovorin; some data suggest further benefit with the addition of the targeted agents bevacizumab or cetuximab. Colorectal cancer primarily affects the elderly; however, much of the defining clinical research in this field has excluded subjects of advanced age or with a poor performance status, making it difficult for clinicians to interpret current treatment paradigms for their older patients. Most clinical trials that have included elderly patients document similar survival rates and toxicity profiles to those seen in younger patients. Moreover, survey data suggest that >70% of elderly patients with cancer are willing to undergo strong, palliative chemotherapy. While these findings suggest that age itself should not determine candidacy for chemotherapy, it is important to note the great heterogeneity of the elderly population with regard to overall health, independence, and performance status. The use of a comprehensive geriatric assessment is recommended to evaluate chemotherapy appropriateness. The management of frail elderly patients and those with a short life expectancy should be focused on palliation, while fit elderly patients can receive aggressive therapy in a similar fashion to younger patients.
“If You Know You Exist, It’s Just Marketing Poison”: Meanings of Tobacco Industry Targeting in the Lesbian, Gay, Bisexual, and Transgender Community
Authors: Smith Elizabeth A. , Thomson Katherine , Offen Naphtali , Malone Ruth E.
Published: April 2008

In the public health literature, it is generally assumed that the perception of “targeting” as positive or negative by the targeted audience depends on the product or message being promoted. Smoking prevalence rates are high among lesbian, gay, bisexual, and transgender (LGBT) individuals, but little is known about how they perceive tobacco industry targeting.

We conducted focus groups with LGBT individuals in 4 US cities to explore their perceptions. Our findings indicated that focus group participants often responded positively to tobacco company targeting.

Targeting connoted community visibility, legitimacy, and economic viability. Participants did not view tobacco as a gay health issue. Targeting is a key aspect of corporate–community interaction. A better understanding of targeting may aid public health efforts to counter corporate disease promotion.
Evaluation of an HIV Prevention Intervention Adapted for Black Men Who Have Sex With Men
Authors: Jones Kenneth T. , Gray Phyllis , Whiteside Y. Omar , Wang Terry , Bost Debra , Dunbar Erica , Foust Evelyn , Johnson Wayne D.
Published: April 2008

Objectives. We assessed the efficacy of an HIV behavioral intervention adapted for Black men who have sex with men (MSM).

Methods. We conducted serial cross-sectional surveys, 1 baseline measurement followed by initiation of an intervention and 3 follow-up measurements, among Black MSM in 3 North Carolina cities over 1 year.

Results. We observed significant decreases in unprotected receptive anal intercourse at 4 months (by 23.8%, n=287) and 8 months (by 24.7%, n=299), and in unprotected insertive anal intercourse (by 35.2%), unprotected receptive anal intercourse (by 44.1%), and any unprotected anal intercourse (by 31.8%) at 12 months (n=268). Additionally, at 12 months, the mean number of partners for unprotected receptive anal intercourse decreased by 40.5%. The mean number of episodes decreased by 53.0% for unprotected insertive anal intercourse, and by 56.8% for unprotected receptive anal intercourse. The percentage of respondents reporting always using condoms for insertive and receptive anal intercourse increased by 23.0% and 30.3%, respectively.

Conclusions. Adapting previously proven interventions designed for other MSM can significantly reduce HIV risk behaviors of Black MSM.