bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromyographic Evaluation of a Bed Assistive Device for Abdominal Surgery Patients in Postoperative Care
Authors: Tran Grace , Babski-Reeves Kari , Nussbaum Maury A.
Published: April 2008

Objective: Muscle activity with and without the use of commercially available patient assistive devices during bed rising and lowering was quantified. Background: Limited research is available in understanding or evaluating the physical benefits of assistive devices for patient use following major abdominal surgery. Methods: Twenty healthy participants (9 men, 11 women) took part in a laboratory study to test the effects of device configuration (five levels) and bed elevation angle (0° and 30°) on mean and peak upper and lower rectus abdominis and external oblique concentric and eccentric muscle activity. Results: Reduced muscle activity was associated with the use of an assistive device, as compared with manual bed rising (unassisted). Positioning the devices at a higher anchor height and/or increasing the bed elevation angle further reduced muscle activity. Objective and subjective differences between the two assistive devices evaluated in the study were found. Conclusion: These results suggest that self-assistive devices may speed recovery because of reduced loads on damaged tissues. Application: Potential applications of this research include the assessment of other commercially available lift aids or comparisons of self-assistive lift aids with hospital-housed lift aids used to speed recovery rates.
Perceptual Distortions Produce Multidimensional Stress Profiles in Novice Users of an Endoscopic Surgery Simulator
Authors: Klein Martina I. , Warm Joel S. , Riley Michael A. , Matthews Gerald , Gaitonde Krishnanath , Donovan James F.
Published: April 2008

Objectives: We determine the impact of perceptual-motor distortions on multidimensional stress dynamics in novice users of an endoscopic/laparoscopic surgery simulator during performance of a peg-transfer task. Background: Surgeons find the endoscopic/laparoscopic surgery procedure to be more mentally stressful than open surgery. This investigation was designed to identify specific stress dimensions associated with these procedures and to determine the contributions to that stress made by loss of depth information resulting from image-guided views of the surgical field and by disruption of eye-hand mapping. Because stress reactions might depend upon familiarity with these procedures, the study focused upon novice participants. Method: An endoscopic box-simulator featured in surgical training was used in conjunction with the Dundee Stress State Questionnaire, a well-validated multidimensional stress state instrument. A control group (no perceptual distortions) viewed the simulated “surgical field” directly. Two other groups viewed the surgical field through TV images in which spatial rotation of the images was absent or in which the images were rotated 90° from the actual line of sight. Results: Performance efficiency in the simulator varied inversely with the degree of perceptual-motor distortion. Reactions reflecting increased task coping were observed in all groups. These were accompanied in the image groups by negative reactions involving decreases in hedonic tone and control and confidence and an increase in tense arousal. Conclusions: Perceptual-motor distortions are sources of complex task-induced stress profiles in novices using an endoscopic surgery simulator. Application: Procedures to reduce stress in endoscopic/laparoscopic surgery trainees may benefit from knowledge regarding specific stress dimensions involved.
Not All Trust Is Created Equal: Dispositional and History-Based Trust in Human-Automation Interactions
Authors: Merritt Stephanie M. , Ilgen Daniel R.
Published: April 2008

Objective: We provide an empirical demonstration of the importance of attending to human user individual differences in examinations of trust and automation use. Background: Past research has generally supported the notions that machine reliability predicts trust in automation, and trust in turn predicts automation use. However, links between user personality and perceptions of the machine with trust in automation have not been empirically established. Method: On our X-ray screening task, 255 students rated trust and made automation use decisions while visually searching for weapons in X-ray images of luggage. Results: We demonstrate that individual differences affect perceptions of machine characteristics when actual machine characteristics are constant, that perceptions account for 52% of trust variance above the effects of actual characteristics, and that perceptions mediate the effects of actual characteristics on trust. Importantly, we also demonstrate that when administered at different times, the same six trust items reflect two types of trust (dispositional trust and history-based trust) and that these two trust constructs are differentially related to other variables. Interactions were found among user characteristics, machine characteristics, and automation use. Conclusion: Our results suggest that increased specificity in the conceptualization and measurement of trust is required, future researchers should assess user perceptions of machine characteristics in addition to actual machine characteristics, and incorporation of user extraversion and propensity to trust machines can increase prediction of automation use decisions. Application: Potential applications include the design of flexible automation training programs tailored to individuals who differ in systematic ways.
Application of the Vienna classification for Crohn’s disease to a single center from Brazil
Authors: Santana Genoile Oliveira , Souza Lorena Rocha , Azevedo Matheus , Sá Ana Carolina , Bastos Clara Maia , Lyra André Castro
Published: April 2008

BACKGROUND: Crohn’s disease is a chronic inflammatory disorder with diversity on its clinical presentation that may be observed from the varying age of onset of symptoms to the site of occurrence of the illness. There is a need for a replicable and uniform description of the disease allowing a comparison between distinct study populations. The 1998 Vienna classification characterizes patients according to three clinical aspects: age at diagnosis, location and disease behavior. AIM: To describe Crohn’s disease in patients from a reference center of Salvador, BA, Brazil according to the Vienna classification. METHODS: Between January and October of 2005, patients (n = 47) having at least one endoscopic and radiological examination of the intestine participated in this study. RESULTS: Most of the participants had the diagnosis of the disease when they were younger than 40 years old (70.2%) while an ileocolic location (38.3%) and the penetrating form (46.8%) were the most prevalent clinical presentation. The restricted location of the ileum (L1) was more frequent in nonstricturing, nonpenetrating disease (B1) while the ileocolic disease (L3) was more associated with the penetrating behavior (B3). CONCLUSION: In this study, differently from the first description of the Vienna classification, the large number of patients presenting a complicated stage of the disease can be attributed to the fact that it was carried out at a reference center, where many patients present with the disease at an advanced stage.
Aplicando recomendações da Escala de Braden e prevenindo úlceras por pressão: evidências do cuidar em enfermagem
Authors: Sousa Cristina Albuquerque de , Santos Iraci dos , Silva Lolita Dopico da
Published: April 2008

Questiona-se o risco de acometimento de úlcera de pressão (UP) no cliente, e a validade do cuidado de enfermagem aplicando a escala de Braden para verificar as evidências desse cuidado na incidência da UP. Utilizou-se o método de medidas biofisiológicas em clientes de UTI. Encontrou-se 11 clientes com UP, numa incidência de 26,83%. A maioria (57,1%) de úlcera encontra-se no estágio I. Clientes com UP têm escores menores que os sem UP mostrando sensibilidade para predizer o risco de UP. Concluiu-se que: a evidência dos cuidados de enfermagem foi demonstrada pela densidade de 47,12 % para os clientes sem UP; a incidência das UP foi menor que as encontradas em outras UTIs; os cuidados de enfermagem preventivos reduzem as UP.
Pessoas com Diabetes Mellitus: suas escolhas de cuidados e tratamentos
Authors: Silva Denise Guerreiro Vieira da , Francioni Fabiane Ferreira , Souza Sabrina da Silva de , Mattosinho Mariza Maria Serafim , Coelho Maria Seloi , Sandoval Rita de Cássia Bruno , Cunha Mila Andrade , Ferreira Nadja
Published: April 2008

Estudo fundamentado na pesquisa qualitativa, na perspectiva interpretativista. Teve como objetivo conhecer o itinerário terapêutico de pessoas com diabetes mellitus na busca de cuidados e tratamentos nos diferentes subsistemas de cuidado a saúde. Os dados foram obtidos através de entrevistas em profundidade e grupos focais. A análise permitiu identificar as modalidades terapêuticas, a avaliação do cuidado e do tratamento à saúde e o percurso terapêutico nos três subsistemas. O Diabetes Mellitus requer mudanças no processo de viver. A pessoa realiza várias modalidades terapêuticas até perceber aquela ou aquelas que lhes são mais adequadas, tanto do ponto de vista do bem estar físico, quanto de como esse cuidado ou tratamento interfere em seu cotidiano.
Temas éticos e bioéticos que inquietaram a Enfermagem: publicações da REBEn de 1970-2000
Authors: Santiago Maria Madalena de Andrade , Palácios Marisa
Published: April 2008

Estudou-se temas éticos e/ou bioéticos publicados na Revista Brasileira de Enfermagem - REBEn, que inquietaram a Enfermagem no período 1970 2000, objetivando identificar nos artigos publicados, temas relacionados à ética/bioética e discutir as perspectivas teóricas nas quais os autores fundamentam suas argumentações. O desenho do estudo é de tipo documental ou bibliográfico. Os resultados mostraram que nos últimos 30 anos houve aumento gradativo, no número de artigos que debatem questionamentos éticos. Os principais temas relacionados à Bioética foram: dilemas e conflitos éticos associados a assistência à saúde, Deontologia, formação ética do enfermeiro e ética em pesquisa. Após 1984 surge o primeiro estudo, versando sobre tema usual da bioética e o termo bioética aparece pela primeira vez em 1998.
Adensamento da beterraba no manejo de plantas daninhas
Authors: Carvalho L.B. , Guzzo C.D.
Published: April 2008

O objetivo deste trabalho foi verificar o efeito do adensamento da semeadura na capacidade de supressão da cultura da beterraba sobre a comunidade infestante. Os tratamentos constituíram-se de 12 períodos semanais crescentes de convivência e controle das plantas daninhas, a partir da segunda semana após a semeadura, submetidos a duas densidades populacionais da cultura (40 e 50 plantas m-2). Avaliou-se o acúmulo de massa seca pelas plantas daninhas em cada período e a estimativa da época e extensão dos períodos críticos de interferência das plantas daninhas em função da produtividade comercial da cultura. Observou-se menor acúmulo de massa seca pelas plantas daninhas quando a cultura foi adensada, sendo a diferença média no acúmulo de 17 e 30% para períodos de convivência e controle, respectivamente. O período crítico de prevenção à interferência foi menor na cultura adensada (11 dias) em relação à não-adensada (22 dias). O adensamento de semeadura da cultura da beterraba proporcionou aumento na capacidade de supressão da cultura sobre a comunidade infestante, afetando o crescimento e a época e extensão dos períodos críticos de interferência das plantas daninhas, podendo ser usado como ferramenta eficaz no manejo da flora invasora.
Implicações da teoria da evolução para a psicologia: a perspectiva da psicologia evolucionista
Authors: Lopes Rafael Gimenes , Vasconcellos Sílvio
Published: April 2008

A idéia de que o comportamento humano está baseado em instintos mostrou-se popular entre os psicólogos há cem anos. Na atualidade, os psicólogos evolucionistas vêm postulando que o comportamento é fortemente influenciado por fatores hereditários, e que os mesmos objetivam ampliar a aptidão. O principal propósito deste estudo foi introduzir e discutir a teoria evolucionista e suas implicações para a área de psicologia. Os autores revisaram artigos e livros sobre o tema. Este artigo pode contribuir para o desenvolvimento de um novo paradigma para a etologia e para a psicologia comparativa no âmbito da psicologia brasileira.
Processo de enfermagem: reflexões de auxiliares e técnicos
Authors: Longaray Vanessa Kenne , Almeida Miriam de Abreu , Cezaro Paula de
Published: April 2008

O Processo de Enfermagem consiste em um instrumento tecnológico empregado para favorecer o cuidado. Trata-se de uma pesquisa qualitativa exploratória descritiva realizada no primeiro semestre de 2006, com o objetivo de conhecer as reflexões de técnicos e auxiliares sobre o Processo de Enfermagem, no Hospital de Clínicas de Porto Alegre - RS. Participaram da pesquisa 11 sujeitos de diferentes serviços. Utilizou-se entrevista semi-estruturada para obtenção de informações e análise temática de Bardin. Na análise identificaram-se cinco categorias: 1) amplia a visão e organiza o cuidado; 2) aproxima a equipe de enfermagem; 3) favorece a continuidade dos cuidados; 4) falhas na comunicação entre a equipe de enfermagem; 5) necessidade de reavaliação da prescrição dos cuidados de enfermagem. Diante do exposto sugere-se fomentar educação em serviço para a equipe de enfermagem tendo como foco o Processo de Enfermagem, dando-se ênfase à comunicação.
A duras penas: estratégias, conquistas e desafios da enfermagem em escala mundial
Authors: Santos Luiz A. de Castro
Published: April 2008

Discutem-se os rumos e transformações da enfermagem como profissão, em escala mundial, desde as últimas décadas do século XIX. Num cenário de intenso intercâmbio de idéias e práticas entre as lideranças do movimento, que desconheciam fronteiras nacionais e conformavam espaços de associação e interação verdadeiramente transnacionais - como o Conselho Internacional de Enfermagem -, a literatura insiste na hegemonia de 'modelos nacionais' diferenciados, prontos para exportação. As idéias que predominavam entre as novas lideranças eram, na verdade, um amálgama de diferentes tradições. O modo como se propagaram variou de país para país, diante das tradições culturais e das estruturas sociais vigentes. No Brasil, não se pode falar de uma 'alternativa francesa' aos rumos da enfermagem, liderados pela Escola Anna Nery, sem que se desfigurasse ou comprometesse o processo de profissionalização então em curso. O processo lento, descontínuo e freqüentemente contraditório, de expansão da enfermagem em todo o mundo, constitui o tema do presente artigo.
A vertigem da descontinuidade: sobre os usos da história na arqueologia de Michel Foucault
Authors: Oliveira Cristiane
Published: April 2008

Abordam-se os usos da história na arqueologia de Foucault, a fim de precisar suas rupturas com o discurso da história tradicionalista. Analisa-se, inicialmente, a noção de 'arqueologia' e indicam-se os seus propósitos, tomando por base as elucidações do próprio autor. Em seguida, descreve-se a trama de noções ('acontecimento', 'formação discursiva' e 'enunciado') que se encontram enredadas no conceito de 'arquivo', buscando demonstrar a inventividade analítica desse autor para a história, problematizada a partir do paradoxo existente entre 'unidade' e 'dispersão de enunciados'. Finalmente, discute-se a enunciação de mecanismos de controle do discurso, a fim de identificar elementos de transição do trabalho descritivo das formações discursivas realizado na arqueologia do saber, para uma análise de estratégias em jogo tanto nas práticas discursivas quanto nas não-discursivas, presentes na genealogia do poder.
Estudo retrospectivo de crianças e jovens com deficiência auditiva: caracterização das etiologias e quadro audiológico
Authors: Pupo Altair Cadrobbi , Balieiro Clay Rienzo , Figueiredo Renata de Souza Lima
Published: April 2008

OBJETIVO: conhecer os fatores de risco para deficiência auditiva e obter informações sobre o tempo transcorrido entre suspeita, diagnóstico e intervenção em crianças e jovens deficientes auditivos atendidos no Serviço de Audiologia Educacional, DERDIC-PUC-SP. MÉTODOS: estudo retrospectivo de 162 prontuários de deficientes auditivos com idade entre um e 17 anos e 6 meses, atendidos de 1999 a 2002. Para registro dos dados utilizou-se a adaptação do protocolo elaborado no Fórum de Reabilitação Aural do Encontro Internacional de Audiologia, no Brasil. RESULTADOS: 54% dos sujeitos eram do sexo masculino e 46% do feminino; 60% tinham idade entre três e oito anos e 11 meses; 43% tiveram a suspeita da deficiência auditiva no primeiro ano de vida. Em 25% dos casos, o diagnóstico ocorreu logo após a suspeita, em 34% ocorreu um intervalo de até um ano; 11% iniciaram atendimento fonoaudiológico após diagnóstico, 54% demoraram até um ano e 27% demoraram mais de um ano. Trinta e dois por cento apresentaram etiologia desconhecida, 18% genética, 17% presumida multifatorial, 15% meningite, 9% rubéola congênita. CONCLUSÃO: a prevalência da etiologia desconhecida aponta para a necessidade do aprofundamento no diagnóstico etiopatológico (estudos genéticos, de imagens e laboratoriais) como rotina para se obter as causas da deficiência auditiva. Observou-se que mesmo após as campanhas de vacinação, a rubéola ainda foi a maior causa de deficiência auditiva congênita e a meningite a maior causa das deficiências auditivas adquiridas após o nascimento. Constatou-se um longo intervalo de tempo entre suspeita, confirmação e início da intervenção fonoaudiológica.
Relationship between stuttering severity in children and their mothers’ speaking rate
Authors: Dehqan Ali , Bakhtiar Mehdi , Panahi Sadegh Seif , Ashayeri Hassan
Published: April 2008

CONTEXT AND OBJECTIVE: Stuttering is a complex disease that influences occupational, social, academic and emotional achievements. The aim of this study was to correlate the stuttering severity index with speaking rates of mothers and children. DESIGN AND SETTING: Cross-sectional study, at the child rehabilitation clinics of Tehran city. METHODS: 35 pairs of mothers and their children who stuttered were studied. There were 29 boys and six girls, of mean age 8.5 years (range: 5.1-12.0). Speech samples from the mother-child pairs were audiotaped for approximately 15 minutes, until a reciprocal verbal interaction had been obtained. This sample was then analyzed in accordance with a stuttering severity index test and speaking rate parameters. RESULTS: The research results outlined a significant relationship between the mothers’ speaking rate and their children’s stuttering severity. CONCLUSION: The results suggest that the mothers’ speaking rate should be incorporated in the assessment and treatment of stuttering.
Bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees (Poaceae): structure in relation to function
Authors: Alvarez Juliana Magalhães , Rocha Joecildo Francisco , Machado Silvia Rodrigues
Published: April 2008

This work reports anatomic and ultrastructural characteristics of bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees. Both the species presented leaf rolling under water stress. The main characteristics observed in these cells were: periclinal wall thinner than the adjacent epidermal wall; abundance of pectic substances in cuticular layer; sinuous anticlinal walls with ramified plasmodesmata; vacuome formed by a developed vacuole or innumerous small vacuoles; abundance of phenolic substances and oil drops. These characteristics suggested the involvement of bulliform cells in the mechanism of foliar involution in the studied species.
Cytogenetic characterization of Hypostomus nigromaculatus (Siluriformes: Loricariidae)
Authors: Rubert Marceléia , Zawadzki Cláudio H. , Giuliano-Caetano Lucia
Published: April 2008

Hypostomus is the most speciose genus in the family Loricariidae, with approximately 120 species. These fish show a wide morphological and color variation, which hinders the identification of species, mainly of widely distributed representatives. The aim of this study was to contribute to the current knowledge on cytogenetic features of Hypostomus nigromaculatus. Three specimens of H. nigromaculatus, collected in two tributaries of rio Tibagi, Paraná, and in Cachoeira de Emas, rio Mogi-Guaçu, São Paulo, the latter being the type locality of H. nigromaculatus, were studied. Chromosomal preparations were submitted to Giemsa staining, silver nitrate impregnation, C-banding and CMA3 and DAPI fluorochromes staining. All samples presented 2n = 76, but the rio Mogi-Guaçu sample differed from those from tributaries of rio Tibagi in relation to karyotype formulae, distribution and composition of heterochromatin, and NOR location. The silver nitrate staining revealed the presence of multiple Ag-NORs for all samples, but with differences on the location on chromosomes. CMA3 staining reveled bright signals equivalent to NOR-bearing chromosomal segments; such sites were characterized by negative, i.e. unstained, marks after DAPI staining. The pattern of heterochromatin distribution was distinctive among samples from rio Mogi-Guaçu and tributaries of rio Tibagi. The differences observed between the sample from rio Mogi-Guaçu and the ones from tributaries of rio Tibagi allow us to suggest that these samples are presently isolated. Further analyses are necessary to ascertain whether such isolation refers to distinct populations or characterizes true different species.
Feeding association between benthic and nektonic Neotropical stream fishes
Authors: Teresa Fabrício Barreto , Carvalho Fernando Rogério
Published: April 2008

Following behaviour among Neotropical stream fishes have been scarcely reported. This type of feeding association was observed in a small stream in the upper rio Paraná system between the catfish, Aspidoras fuscoguttatus, acting as a nuclear species, and Knodus moenkhausii, Poecilia reticulata, and Astyanax altiparanae as follower species. Aspidoras fuscoguttatus individuals dug in the bottom during feeding, causing sediment suspension. Their followers picked food items in the "cloud" of suspended particles. Food items of sediment are no longer consumed by the catfish when in suspension, but are still available for K. moenkhausii, P. reticulata and A. altiparanae. Following behaviour is an alternative feeding tactic for these species, which reinforces the general idea of behavioural plasticity among follower species.
Spatially distributed ecological risk for fish of a coastal food web exposed to dioxins
Authors: Micheletti Christian , Lovato Tomas , Critto Andrea , Pastres Roberto , Marcomini Antonio
Published: April 2008

The ecological risk posed by 2,3,7,8-polychlorodibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyl (PCB) congeners to five edible fish species of the aquatic food web of Venice Lagoon, Italy, was estimated by applying a state-of the-art kinetic bioaccumulation model. Site-specific data were used to define a representative food web. The experimental data set for model validation and application included PCB and PCDD/F congener concentrations in sediments, in water, and in five organisms (both invertebrates and fish). The spatial distribution of risk was evaluated by dividing the lagoon into six homogeneous areas, and for each area, sediment, water, and organism dioxins concentrations were calculated. The bioaccumulation model was calibrated for both nonmetabolizing and metabolizing congeners, the metabolic elimination rates of which were estimated. The model validation showed an acceptable bioaccumulation estimation, evaluated using the model bias parameter. The calibrated model was applied to the six areas of the lagoon to estimate the fish predicted exposure concentration as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents from sediment concentration. Internal no-effect concentrations were calculated for each fish species from literature data. Risk was estimated by applying the hazard quotient (HQ) approach, obtaining the ecological risk for each fish species on the basis of 90 and 99% protection levels, in each of the six lagoon areas. The sediment dioxins concentration does not pose a significant risk to the selected fish species at the 90% protection target (HQ < 1), whereas risk is significant (HQ > 1) at the 99% protection target. Risk results were higher near the Porto Marghera industrial district, Italy, and in lagoon zones characterized by a low water-exchange rate and freshwater basin inputs.
Ecotoxicological evaluation of octachlorostyrene in fourth instar larvae of Chironomus riparius (Diptera, chironomidae)
Authors: Lee Si-Won , Park Kwangsik , Hong Jongki , Choi Jinhee
Published: April 2008

The ecotoxicological effects of octachlorostyrene (OCS) on the aquatic larvae of the nonbiting midges Chironomus riparius (Diptera, Chironomidae) were investigated by evaluating their responses in various biological organizations, from the molecular and biochemical to the ecophysiological levels. The results of the 24-h lethality test of OCS on C. riparius suggest that this compound has a low acute toxic potential with respect to this species. The OCS exhibited serious chronic toxicity in C. riparius, however, especially on the species' development (pupation and emergence failure), the sex ratio of the emerged adults (high female to male ratio), and the adults' reproduction (oviposition failure). As the basic premise that changes in the gene expression can be harnessed to diagnose the exposure and effects of environmental chemicals is currently receiving significant attention, the increase in the expression of the heat shock protein and hemoglobin genes suggests that altered molecular-level parameters could be interpreted as early warning biomarkers of chemical stress. The establishment of a causal relationship between molecular and organism or population indicators is important, however, from the ecotoxicological point of view, although it is difficult to perform. The experimental evidence generated in the present study, especially at the molecular and biochemical levels, is not sufficient to demonstrate a plausible mechanistic linkage among responses across biological levels. Had more parameters at the molecular and biochemical levels been investigated, the mechanistic linkage might have been better identified. A mechanistic study appears to be necessary to understand causal relationships between gene expression and higher-level consequences, such as development and reproduction. The results of the present study may constitute an important contribution to knowledge on the ecotoxicology of OCS in aquatic organisms, about which little data is available.
Acute lethal and teratogenic effects of tributyltin chloride and copper chloride on mahi mahi (Coryphaena hippurus) eggs and larvae
Authors: Adema-Hannes Rachel , Shenker Jonathan
Published: April 2008

Acute and chronic bioassays were used to evaluate the lethal and sublethal effects of copper chloride and tributyltin chloride on mahi mahi (Coryphaena hippurus) embryos, a pelagic life stage often found in the surface microlayer where anthropogenic contaminants can accumulate. Acute bioassay testing determined the median lethal concentration (LC50) for the test organism after 48 h of exposure. Chronic toxicity tests were used to determine the measurement of sublethal parameters, such as developmental abnormalities after 72-h exposures to the toxicants. Embryos were collected 4 h postfertilization and subsequently exposed to 1, 5, 25, 50, and 100 μg/L of copper chloride and 3, 10, 20, 30, and 50 μg/L of tributyltin chloride. Analysis of hatch rate percentage determined that the mean 48-h LC50 of copper chloride and tributyltin chloride was 32.8 and 16.7 μg/L, respectively, based on the pooled data of four experiments with four replicates for each metal. Consistent abnormalities, such as yolk sac swelling, spinal deformities, and decreased hatch rates, were observed for each metal. Teratogenic responses to copper chloride and tributyltin chloride demonstrate the need to investigate further the impacts of pollution in the open oceans to a species indigenous to, and commercially important to, the Florida (USA) coasts. This information could then lead to the future development of a surface microlayer bioassay using mahi mahi embryos.
Fate of the nonsteroidal anti-inflammatory drug naproxen in agricultural soil receiving liquid municipal biosolids
Authors: Topp Edward , Hendel John G , Lapen David R , Chapman Ralph
Published: April 2008

Naproxen (2-(6-methoxy-2-naphthyl) propionic acid) is widely used for the treatment of pain and swelling associated with arthritis, gout, and other inflammatory conditions. Naproxen has been detected in municipal sewage outflows and in surface waters and could reach agricultural land through the application of municipal biosolids or reclaimed water. The persistence characteristics of naproxen in three agricultural soils were investigated. In laboratory microcosms of moist soil incubated at 30°C, [O-14CH3]naproxen was rapidly and thoroughly mineralized to 14CO2 with comparable kinetics in a sandy loam soil, a loam soil, and a silt loam soil. Naproxen mineralization was responsive to soil temperature and soil moisture content, consistent with the primary mechanism of dissipation being biodegradation. Mineralization of naproxen was hastened by the addition of liquid municipal biosolids (LMBs) from a municipal sewage treatment plant that aerated this material. Naproxen was stable in autoclaved soils with or without addition of autoclaved LMBs, whereas naproxen was rapidly mineralized in sterile soil supplemented with nonsterile LMBs. An enrichment culture was obtained from aerobically digested LMBs in a mineral salts medium with naproxen as the sole source of carbon. The culture converted the parent compound to the corresponding naphthol, O-desmethyl naproxen. In summary, naproxen was rapidly removed from soil, with mesophilic aerobic biodegradation being the primary mechanism of dissipation. Microorganisms carried in biosolids enhanced naproxen dissipation in soil, with the initial mechanism of attack likely being O-demethylation. We conclude on this basis that naproxen in soils receiving biosolids would be readily biodegradable and, in the absence of preferential flow or runoff, pose little risk for contamination of adjacent water or crops.
Research on micro-particles distribution character in water treatment processes
Authors: Guangqi Liu , Yanhong Kong , Lihui Jiang , Yongpeng Xu
Published: April 2008

In this paper we studied the particle size and distribution (PSD) character during conventional water treatment process. By measuring the particle size and distribution of raw-water, settled water and filtered water, we developed a log-log model between particle diameter and amount, which can be described as ln n=−β ln Dp+K. The value of collision frequency factor β in the PSD log-log model can represent the particles' dynamic behavior, and can provide a foundation to choose a more suitable coagulation mode in accelerating particles aggregation. At the same time, we deduced the relationship ln V=bK+C between the value of parameter K and the total particles volume V. Lots of experiments proved the conclusion's validity. K is defined as particle volume exponent, which can represent the total volume of particles. K's degression degree shows the removal efficiency of potable water treatment units.
Aggregation capability of a fluidised layer of granular material during treatment of water with high DOC and low alkalinity
Authors: Pivokonsky M. , Pivokonska L. , Tomaskova H.
Published: April 2008

The aim of this contribution is to investigate aggregation efficiencies when a fluidised layer of granular material (FLGM) is applied for a treatment of surface water with high DOC (Dissolved Organic Carbon) and low alkalinity in a pilot size operation. It was shown that the FLGM can be effective for agitation of a system using destabilised particles with the aim to form readily separable suspension. An aggregation efficiency of the FLGM reactor was evaluated by the degrees of destabilisation and aggregation of the particles of impurities. The maximal separation efficiencies of the pilot plant after filtration attained φAl = 0.96 and φDOC = 0.73. These values exceeded not negligibly the ones reported for the conventional aggregation processes.
Environmental effects analysis of a wastewater reuse system for agriculture in Korea
Authors: Jang Tae Il , Park Seung Woo , Kim Hak Kwan
Published: April 2008

The long-term goal of this research is to develop the infra-technologies to reclaim effluents from wastewater treatment plants and reuse them for agricultural water demands. The objectives of this were: 1) to study the effects of various wastewater treatment levels on crop growth and yields; 2) to determine the pollution loads from wastewater applications to paddy fields, and explore potential health hazards; 3) to investigate the treatment efficiencies of three different levels of treatment systems; and 4) to assess the agro-environmental effects of reusable wastewater resources. Wastewater reuse systems can be greatly beneficial for irrigating crops and improving river water quality. Field experiments for cultivating rice with reclaimed wastewater were carried out on the test plots. The effects of various wastewater treatment levels on water quality, paddy soil, crop growth, yields, and the health hazards were investigated.
Bridging the Gap between Spreadsheet Use and Control: An Instructional Case
Authors: Loraas Tina M. , Mueller Jennifer M.
Published: April 2008

End user applications (such as spreadsheets) have been cited as a previously ignored yet potentially significant risk to financial reporting in the wake of The Sarbanes-Oxley Act (PricewaterhouseCoopers [PwC] 2004; Ernst&Young [E&Y] 2004). We developed a realistic spreadsheet model in order to expose students to internal control issues inherent in a spreadsheet environment. By completing the case, students develop skills relating to auditing information systems and evaluating spreadsheet controls, functions, and formulas. Students also have an opportunity to improve written communication skills by conveying their findings to others in a memorandum.
Exploring the Effect of Distance: An Experimental Investigation of Virtual Collaboration, Social Loafing, and Group Decisions
Authors: Blaskovich Jennifer L.
Published: April 2008

Contemporary businesses are rapidly embracing virtual collaboration as a flexible, cheaper, and more efficient method for conducting group work. Past research has shown, however, that virtual groups operate quite differently than face-to-face groups. In this study, Social Impact Theory provides a framework to investigate whether virtual collaboration heightens social loafing—the tendency for individuals to contribute less than full effort to a group. The theory predicts that member distance, inherent in virtual collaboration, increases the propensity of group members to loaf, and decreases group performance. Two hundred seventy-nine participants assigned to face-to-face or virtual groups completed a business resources allocation task. Results suggest that virtual collaboration negatively affects group performance and that social loafing behavior may partially explain this result. The findings imply that organizations should carefully consider whether virtual collaboration can be seamlessly substituted for face-to-face group interaction.
Protective Role of Programmed Death 1 Ligand 1 (PD-L1)in Nonobese Diabetic Mice
Authors: Wang Chia-Jen , Chou Feng-Cheng , Chu Chi-Hong , Wu Jen-Chine , Lin Shih-Hua , Chang Deh-Ming , Sytwu Huey-Kang
Published: April 2008

OBJECTIVE—Coinhibitory signals mediated via programmed death 1 (PD-1) receptor play a critical role in downregulating immune responses and in maintaining peripheral tolerance. Programmed death 1 ligand 1 (PD-L1), the interacting ligand for PD-1, widely expressed in many cell types, acts as a tissue-specific negative regulator of pathogenic T-cell responses. We investigated the protective potential of PD-L1 on autoimmune diabetes by transgenically overexpressing PD-L1 in pancreatic β-cells in nonobese diabetic (NOD) mice.

RESEARCH DESIGN AND METHODS—We established an insulin promoter–driven murine PD-L1 transgenic NOD mouse model to directly evaluate the protective effect of an organ-specific PD-L1 transgene against autoimmune diabetes. Transgene expression, insulitis, and diabetic incidence were characterized in these transgenic NOD mice. Lymphocyte development, Th1 cells, and regulatory T-cells were analyzed in these transgenic mice; and T-cell proliferation, adoptive transfer, and islet transplantation were performed to evaluate the PD-L1 transgene–mediated immune-protective mechanisms.

RESULTS—The severity of insulitis in these transgenic mice is significantly decreased, disease onset is delayed, and the incidence of diabetes is markedly decreased compared with littermate controls. NOD/SCID mice that received lymphocytes from transgenic mice became diabetic at a slower rate than mice receiving control lymphocytes. Moreover, lymphocytes collected from recipients transferred by lymphocytes from transgenic mice revealed less proliferative potential than lymphocytes obtained from control recipients. Transgenic islets transplanted in diabetic recipients survived moderately longer than control islets.

CONCLUSIONS—Our results demonstrate the protective potential of transgenic PD-L1 in autoimmune diabetes and illustrate its role in downregulating diabetogenic T-cells in NOD mice.
Modified Matrix Band Design for Ultra-conservative Posterior Restorations
Authors: Deliperi S.
Published: April 2008

Clinical Relevance

The combination of minimally invasive cavity preparations and adhesive restorations allows clinicians a significantly more conservative approach to proximal carious lesions of teeth adjacent to MO/DO preparations.
The Effect of Subject Age on the Microtensile Bond Strengths of a Resin and a Resin-modified Glass Ionomer Adhesive to Tooth Structure
Authors: Brackett W. W. , Tay F. R. , Looney S. W. , Ito S. , Haisch L. D. , Pashley D. H.
Published: April 2008

Clinical Relevance

For the materials tested, there was no difference in adhesion to young and aged tooth structure.
Dextran
Authors: de Belder Anthony N.
Published: April 2008

The article contains sections titled:

1.

Introduction

2.

Structure, Chemical, and Physicochemical Properties

2.1.

Structure

2.2.

Physicochemical Properties

2.3.

Reactivity

3.

Production

3.1.

Biosynthesis

3.2.

Production of Clinical Dextran

3.3.

Future Trends

4.

Quality Specifications

5.

Storage

6.

Uses

6.1.

Clinical Products

6.2.

General Uses

7.

Economic Aspects

8.

Toxicology
Polymer Photovoltaic Devices Employing a Chemically Fixed p–i–n Junction
Authors: Leger Janelle M. , Patel Dinesh G. , Rodovsky Deanna B. , Bartholomew Glenn P.
Published: April 2008

Polymer photovoltaic devices commonly suffer from low power conversion efficiencies despite the potential for much higher performance. Here we apply a recently reported system for creating a chemically fixed polymer p‐i‐n junction to polymer photovoltaic devices. Both single‐component and blended donor/acceptor devices are fabricated and tested. We study the devices during charging and find that the changes in light and dark current characteristics are consistent with the formation of a p‐i‐n junction in the active material. While the overall performance of these systems need improvement, the devices show promising open circuit voltages, suggesting the possibility for improving the state‐of‐the‐art in polymer photovoltaic techno logies with continued materials development.
Virus Filtration Membranes Prepared from Nanoporous Block Copolymers with Good Dimensional Stability under High Pressures and Excellent Solvent Resistance
Authors: Yang Seung Yun , Park Jihoon , Yoon Jinhwan , Ree Moonhor , Jang Sung Key , Kim Jin Kon
Published: April 2008

We introduce a nanoporous membrane suitable for virus filtration with good dimensional stability under high pressures maintaining high selectivity. The membrane consists of a double layer: The upper layer is a nanoporous film with pore size of ∼17 nm and a thickness of ∼160 nm, which was prepared by polystyrene‐block‐poly(methyl methacrylate) copolymer (PS‐b‐PMMA) where PMMA block was removed by ultraviolet irradiation followed by rinsing with acetic acid. The nanoporous block copolymer film was combined with a conventional micro‐filtration membrane to enhance mechanical strength. The membrane employed in this study did not show any damage or crack even at a pressure of 2 bar, while high selectivity was maintained for the filtration of human rhinovirus type 14 which has a diameter of ∼30 nm and is a major pathogen of the common cold in humans. Furthermore, due to crosslinked PS matrix during the UV irradiation, the nanoporous membrane showed excellent resistance to all organic solvents. This could be used under harsh filtration conditions such as high temperature and strong acidic (or basic) solution.
Effect of Charge Density on Energy‐Transfer Properties of Cationic Conjugated Polymers
Authors: Pu Kan‐Yi , Fang Zhen , Liu Bin
Published: April 2008

Cationic conjugated polymers (CCPs) with different charge densities are synthesized via Suzuki polymerization. The CCPs show similar optical properties in aqueous solutions but obvious difference in fluorescence resonance energy transfer (FRET) to Texas Red‐labeled single‐stranded DNA (ssDNA‐TR). Both CCP and TR fluorescence quenching are revealed to influence the energy‐transfer process. The difference in quantum yields of CCP/ssDNA complexes highlights the importance of polymer side‐chain structures and charge density. A CCP with a high charge density and ethylene oxide as the side chain provides the highest quantum yield for CCP/ssDNA complexes, which favors FRET. TR quenching within the CCP/ssDNA complexes is predominantly determined by the CCP charge density. In contrast to the other two polymers, the CCP with low charge density provides the most‐intense polymer‐sensitized TR emission, which is due to the collective response of more optically active polymer units around TR and the minimized TR self‐quenching within the CCP/ssDNA‐TR complexes. These studies provide a new guideline for improving the signal amplification of conjugated‐polymer‐based optical sensors.
Third‐Order Nonlinear Optical Response of Gold‐Island Films
Authors: Xenogiannopoulou Evangelia , Iliopoulos Kostas , Couris Stelios , Karakouz Tanya , Vaskevich Alexander , Rubinstein Israel
Published: April 2008

Films of gold nanoscaled islands with thicknesses ranging between 0.5 and 15 nm were prepared by thermal evaporation onto untreated and aminosilane‐pretreated glass substrates. Post‐deposition annealing was found to modify the morphological characteristics of the islands (e.g., average island area and height, inter‐island distance, etc.), resulting in changes of the localized surface plasmon resonance (SPR) characteristics and, therefore, modifying the nonlinear optical (NLO) response of the films. The NLO response of both unannealed and annealed (20 h at 200 °C) films was studied by means of the optical Kerr effect (OKE), using 35 ps, 532 nm laser excitation, while measurements performed by means of the Z‐scan technique allowed for the determination of both the nonlinear refraction and absorption characteristics of the films. The results are discussed and compared with other reports.
Organosilica Materials with Bridging Phenyl Derivatives Incorporated into the Surfaces of Mesoporous Solids
Authors: Kuschel Andreas , Polarz Sebastian
Published: April 2008

An interesting class of materials is mesoporous organosilica materials containing a bridging, organic group along the pore‐surface. Such materials are prepared from silsesquioxane precursors of the type (R′O)3Si‐R‐Si(OR′)3 where R is the bridging organic group of interest, in combination with a lyotropic phase as a template for the generation of the pores. A new silsesquioxane precursor, 1,3‐bis‐(trialkoxysilyl)‐5‐bromobenzene, and the related mesoporous organosilica material containing bromobenzene groups located at the pore walls are presented in the current publication. The latter precursor allows access to the derivatization reactions known for halogenated aromatic compounds. Materials containing phenyl derivatives can be obtained either by chemical modifications starting from the mentioned precursor on the molecular scale, or the modifications can be performed directly at the surfaces of the porous material. Materials with surfaces containing benzoic acid, styrene, and phenylphosphonic acid are described.
Asymmetric Organocatalysis: From Infancy to Adolescence
Authors: Dondoni Alessandro , Massi Alessandro
Published: April 2008

After an initial period of validating asymmetric organocatalysis by using a wide range of important model reactions that constitute the essential tools of organic synthesis, the time has now been reached when organocatalysis can be used to address specific issues and solve pending problems of stereochemical relevance. This Review deals with selected studies reported in 2006 and the first half of 2007, and is intended to highlight four main aspects that may be taken as testimony of the present status and prospective of organocatalysis: a) chemical efficiency; b) discovery of new substrate combinations to give new asymmetric syntheses; c) development of new catalysts for specific purposes by using mechanistic findings; and d) applications of organocatalytic reactions in the asymmetric total synthesis of target natural products and known compounds of biological and pharmaceutical relevance.
Preparation and characterization of poly(vinyl alcohol) and gelatin blend films
Authors: Pawde S. M. , Deshmukh Kalim , Parab Sanmesh
Published: April 2008

Poly(vinyl alcohol) (PVA) is a water‐soluble polymer that has been studied intensively because of several interesting physical properties that are useful in technical applications, including biochemical and medical applications. In this article, we report the effects of the addition of gelatin on the optical, microstructural, thermal, and electrical properties of PVA. Pure and PVA/gelatin blend films were prepared with the solution‐casting method. These films were further investigated with Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, and dielectric measurements. The FTIR spectrum shows a strong chemical interaction between PVA and gelatin molecules with the formation of new peaks. These peaks are due to the presence of gelatin in the blend films. The DSC results indicate that the addition of gelatin to PVA changes the thermal behavior, such as the melting temperature of PVA, and this shows that the blends are compatible with each other. This also shows that the interaction of gelatin and PVA molecules changes the crystallite parameters and the degree of crystallinity, and this supports the XRD results. The UV–vis optical study also reflects the formation of the complex and its effect on the microstructure of the blend film. Moreover, the addition of gelatin also gives rise to changes in the electrical properties of PVA/gelatin blend films. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Instant modification of graphite nanosheets by the grafting of a styrene oligomer under microwave radiation
Authors: Li Jianping , Lin Hongfei , Zhao Weifeng , Chen Guohua
Published: April 2008

Instant grafting polymerization of styrene initiated by microwave radiation on the surface of graphite nanosheets (GNs) was carried out. The stability of the modified GN dispersions in different solvents indicated significant changes in the surface properties of GNs. In comparison with GNs without modification, the modified GNs showed more stable suspensions in a nonpolar organic solvent such as toluene and were more likely to form a precipitate when dispersed in distilled water, a polar solvent. Fourier transform infrared and thermogravimetric analysis were used to confirm the functionalized GNs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008