bluuebunny/crossref_metadata_2025 huggingface dataset:
Competição entre soja resistente ao glyphosate e plantas daninhas em solo compactado
Authors: Santos J.B. , Lázari T.M. , Camelo G.N. , Oliveira T.A. , Figueiredo J.L.A.
Published: April 2008

Objetivou-se com este trabalho avaliar a competição entre a soja (var. BRS 243 RR) e as plantas daninhas Bidens pilosa e Brachiaria brizantha, em diferentes níveis de compactação do solo. Para isso, foram confeccionadas colunas de PVC (10 cm de diâmetro) com três anéis: superior (com 5 cm de altura e densidade de 1,2 kg dm-3), intermediário (com 10 cm de altura e densidade variando entre 1,0 e 1,6 kg dm-3, conforme tratamento) e inferior (com 10 cm de altura e densidade de 1,2 kg dm-3). Sobre as colunas foram realizados cinco cultivos: soja, B. pilosa, B. brizantha, soja e B. pilosa e soja e B. brizantha, em esquema fatorial com as densidades, perfazendo um total de 20 tratamentos. Aos 30 dias após emergência da soja, foram avaliadas a altura, a massa seca de folhas, de caule e de raízes (em cada anel, separadamente), a área foliar e a área foliar específica. Observou-se que B. brizantha foi mais competitiva que B. pilosa; contudo, esta última possui maior capacidade de exploração radicular em solos com maior nível de compactação, indicando maior adaptabilidade a condições como déficit hídrico e escassez de nutrientes. Considerando a capacidade competitiva da soja sobre as plantas daninhas, maiores níveis de compactação favorecem a cultura, em relação a B. pilosa.
Comunicação equipe-família em unidade de terapia intensiva pediátrica: impacto no processo de hospitalização
Authors: Nieweglowski Viviane Hultmann , Moré Carmen Leontina Ojeda Ocampo
Published: April 2008

Este artigo resulta de um estudo que teve como objetivo analisar o processo de comunicação equipe-família e seu impacto em todos os envolvidos na situação de internação, na perspectiva da Teoria da Pragmática da Comunicação Humana. Buscou-se trazer à tona subsídios para instrumentalizar a equipe, visando um melhor entendimento da comunicação diagnóstica e da hospitalização, favorecendo estratégias de enfrentamento para a mencionada situação. Foi uma pesquisa de base qualitativa, na qual foram realizadas entrevistas semi-estruturadas com 16 familiares de oito crianças internadas na unidade de terapia intensiva pediátrica de um hospital Público de Santa Catarina. A análise dos dados, agrupados em unidades temáticas, evidenciou a presença de uma trama comunicacional multideterminada na comunicação entre equipe de saúde e família, a qual afetava decisivamente o processo interacional dos envolvidos. Por sua vez, isto tinha uma repercussão direta na qualidade do trabalho dos profissionais e no maior ou menor sofrimento emocional da família.
Avaliação de famílias no contexto hospitalar: uma aproximação entre o modelo Calgary e a taxonomia da NANDA
Authors: Montefusco Selma Rodrigues Alves , Bachion Maria Márcia , Nakatani Adélia Yaeko Kyosen
Published: April 2008

Esta pesquisa objetivou analisar os diagnósticos de enfermagem da North American Nursing Diagnosis Association (2006) identificados em famílias em situação de acompanhamento de pessoas hospitalizadas para tratamento de doenças crônicas não transmissíveis, mediante abordagem baseada no Modelo Calgary de Avaliação. Trata-se de estudo descritivo, de abordagem quanti-qualitativa, realizado na clínica médica de um hospital escola da região centro-oeste, de janeiro a junho de 2006. Foram realizadas entrevistas gravadas com 12 famílias. Os dados passaram por um processo de categorização, identificação de lacunas e divergências, agrupamento de padrões, inferência diagnóstica e determinação das relações, a partir do qual estabeleceram-se os diagnósticos. Entre as 12 categorias diagnósticas identificadas, as mais freqüentes foram: tensão devido ao papel de cuidador (100%), comunicação verbal da família prejudicada (75%), manutenção do lar prejudicada (66%), processos familiares interrompidos (66%), interação social prejudicada (25%). Este perfil identifica áreas prioritárias de cuidado integral de enfermagem para famílias em situação de hospitalar.
O óleo de chaulmoogra como conhecimento científico: a construção de uma terapêutica antileprótica
Authors: Santos Fernando Sergio Dumas dos , Souza Letícia Pumar Alves de , Siani Antonio Carlos
Published: April 2008

Analisa os processos de assimilação e transformação de saberes e práticas terapêuticas que envolvem o uso de plantas medicinais, e destaca o uso, no combate à lepra, do óleo da chaulmoogra. Atenta para os diferentes modos de incorporação e transformação das chaulmoogras em conhecimentos validados cientificamente, tendo em vista a entrada em cena da 'chaulmoogra brasileira'. Privilegia a chegada dos derivados dessa planta à pauta de produção do Instituto Oswaldo Cruz (IOC), na década de 1920, estabelecendo nexos entre os diferentes processos produtivos e articulando-os ao contexto científico no período estudado. O óleo de chaulmoogra representou, até a década de 1940, a grande esperança para a tentativa de cura da lepra. Observa ainda que a terapêutica chaulmúgrica durante esse período, consolidou-se como um saber científico graças à realização de diversas pesquisas feitas em laboratórios de todo o mundo ocidental.
Aspectos neurofisiológicos da musculatura facial visando a reabilitação na paralisia facial
Authors: Tessitore Adriana , Pfelsticker Leopoldo Nisan , Paschoal Jorge Rizzato
Published: April 2008

OBJETIVO: revisão teórica dos aspectos e particularidades neurofisiológicas relevantes da musculatura orofacial, visando a reabilitação na paralisia facial periférica. MÉTODOS: revisão da literatura sobre neuro-anatomofisiologia da musculatura orofacial mediante pesquisa dos artigos dos periódicos nacionais e internacionais e nos livros científicos sobre o tema, no período entre 1995 a 2005. RESULTADOS: foram revistas 50 referências neste trabalho. Destas, 20 sobre neurofisiologia, 14 sobre neuroanatomia. As demais sobre fonoaudiologia e paralisia facial. Os artigos de neurofisiologia e neuroanatomia estudados foram divididos em três grupos: I - Aspectos do complexo neuromuscular; II - Características morfológicas e histoquímicas dos músculos da face e III - Denervação e atrofia muscular. CONCLUSÃO: a partir dos achados, procurou-se sistematizar didaticamente as particularidades da neuro-anatomofisiologia, cujo conhecimento, na impressão dos autores, são relevantes para o sucesso na reabilitação da paralisia facial.
Resultados timpanométricos: lactentes de seis meses de idade
Authors: Melo Juliana Jandre , Lewis Dóris Ruth , Marchiori Luciana Lozza de Moraes
Published: April 2008

OBJETIVO: verificar os achados timpanométricos em lactentes de seis meses de idade, sendo ou não amamentados com aleitamento materno exclusivo e/ou predominante. MÉTODOS: foram avaliados 46 lactentes que estavam com seis meses na data da avaliação, sendo que 30 (61,22%) lactentes estavam sendo submetidos à amamentação exclusiva por um período mínimo de seis meses e 16 (34,78%) lactentes não estavam em aleitamento exclusivo. Os lactentes foram submetidos à inspeção do meato acústico externo e a realização da timpanometria. RESULTADOS: houve diferença estatisticamente significante (p=0,0084) nos achados de alteração timpanométrica em lactentes amamentados por mais tempo. Em relação ao sexo dos lactentes relacionados ao tempo de amamentação, apenas o masculino apresentou resultados estatisticamente significantes (p=0,0006) em relação ao fator de proteção de curvas timpanométricas normais. Em relação aos outros fatores analisados, não foi possível encontrar relação entre tempo de amamentação exclusiva e alterações timpanométricas. CONCLUSÃO: apesar de existirem outros fatores de risco, a amamentação exclusiva por um período de seis meses, atua como um fator de proteção contra alterações timpanométricas, não necessitando da introdução de outros alimentos antes deste período recomendado como ideal pela Organização Mundial de Saúde.
Biological response of spontaneously hypertensive rats to the streptozotocin administration
Authors: Costa Virginia Alice Vieira da , Vianna Lucia Marques
Published: April 2008

The sensitivity of adult spontaneously hypertensive rats (SHR) to the diabetogenic effect of streptozotocin (STZ) was studied. The animals were subdivided into three groups: control (citrate buffer), streptozotocin 40 mg/kg or 50 mg/kg, and general biologic parameters were analyzed, in addition to systolic blood pressure, blood glucose and insulin levels determinations. Both doses were able to induce hyperglycemia above 300 mg/dl; however, 50 mg/kg provoked a more pronounced physiological alterations in body weight, diuresis, water and food intake. There was no change on systolic blood pressure with either dose. Results suggested that SHRs did not need doses of streptozotocin above 40mg/kg in order to produce diabetes probably because this strain was much more sensible than normotensive rats. In addition, streptozotocin might be a drug choice to induce diabetes without provoking alterations in the blood pressure which allowed the use of this experimental model in the studies of induced hypertension-diabetes.
Morphoagronomic genetic diversity in american wild rice species
Authors: Veasey Elizabeth Ann , Silva Edson Ferreira da , Schammass Eliana Aparecida , Oliveira Giancarlo Conde Xavier , Ando Akihiko
Published: April 2008

To characterize the genetic variability among species and populations of South American wild rice, eleven populations of Oryza glumaepatula, seven of O. grandiglumis, four of O. latifolia and one of O. alta, from Brazil and Argentina, were evaluated. A greenhouse experiment was conducted in completely randomized blocks with 23 treatments. Twenty morphoagronomic traits were assessed. Univariate analyses were performed with 16 quantitative traits with the partitioning of populations within species. Significant differences (p<0.001) between species were observed for all the traits as well as among populations within the species. The most variable was O. glumaepatula followed by O. latifolia. Multivariate discriminant canonical and cluster analyses confirmed the separation of the highly diverse O. glumaepatula populations from the tetraploid species, and the high genetic variation among O. latifolia populations. Morphological differences among the three tetraploid species seemed to be enough to ascribe them at least the condition of species in statu nascendi.
Response of a new zealand mayfly (Deleatidium spp.) to acid mine drainage: Implications for mine remediation
Authors: O'Halloran Kathryn , Cavanagh Jo-Anne , Harding Jon S
Published: April 2008

Investigating the toxicity of acid mine drainage (AMD) on benthic communities in receiving waters can be highly challenging because of the difficulty in unraveling the effects of acidity, dissolved metals, and precipitates. Furthermore, the survival of different species may vary depending on any natural adaptation they may have acquired to low pH, metals, or sedimentation. We investigated the effect of different pHs and AMD on the survival of a common New Zealand leptophlebiid mayfly (Deleatidium spp.) in 96-h laboratory trials. Our results indicate that the primary driver of toxicity in AMD was pH, although some mortality could be attributable to the presence of dissolved heavy metals at low pH (≤3.6). Mayflies sourced from three naturally acidic streams (pH ≈︁ 5.7-6.5) had a distinctly higher tolerance to AMD and low pH (3.5-4.0) compared to mayflies sourced from three circumneutral streams (pH ≈︁ 7.0-7.4). This indicates that the chemistry of the natal stream strongly influences the sensitivity of mayflies to AMD, which, in turn, could have consequences for the successful remediation of a given AMD-impacted stream. Furthermore, the water chemistry of unimpacted streams that could be sources of potential recolonists might provide ecologically relevant water-quality targets for remediation of AMD-damaged streams. Understanding the variable tolerances of common lotic benthic taxa can provide ecologically relevant water-quality criteria for mine remediation.
Evaluating the trophic transfer of cadmium, polonium, and methylmercury in an estuarine food chain
Authors: Mathews Teresa , Fisher Nicholas S
Published: April 2008

We examined the transfer of Cd, methylmercury (MeHg), and Po in an estuarine food chain (from phytoplankton to zooplankton [Daphnia pulex] to killifish [Fundulus heteroclitus] and, finally, to juvenile striped bass [Morone saxatilis]) to better understand both the extent to which these elements may biomagnify and the underlying mechanisms governing this biomagnification. Among the phytoplankton examined (Cyclotella meneghiniana and Chlamdomonas reinhardtii), metal uptake was rapid, and volume concentration factors for all metals reached values between 104 and 105. The resulting assimilation efficiencies (AEs) of ingested metals in all animals were highest for MeHg, with values greater than 76%. The AEs of Cd were 21 to 33% in D. pulex, 1 to 16% in F. heteroclitus, and 38 to 56% in M. saxatilis. Polonium AEs were 69 to 87% in D. pulex, 25 to 41% in F. heteroclitus, and 9 to 21% in M. saxatilis. Loss rate constants (ke) of metals in D. pulex ranged from 0.04/d for MeHg to 0.39/d for Po; metal ke values for F. heteroclitus ranged from 0.01 to 0.02/d. Using a kinetic model, we showed that the trophic transfer factor, defined as the ratio of metal concentration in predatory animals to metal concentration in prey organisms, was greater than unity for all three metals in D. pulex feeding on phytoplankton, suggesting that these metals may be biomagnified at this trophic step. In killifish feeding on D. pulex, the trophic transfer factor was consistently greater than one for MeHg, consistently less than one for Cd, and from 0.1 to 1.4 for Po, suggesting that both MeHg and Po have the potential to biomagnify at this trophic step.
“What exactly are you inferring?” A closer look at hypothesis testing
Authors: Newman Michael C
Published: April 2008

This critical review describes the confused application of significance tests in environmental toxicology and chemistry that often produces incorrect inferences and indefensible regulatory decisions. Following a brief review of statistical testing theory, nine recommendations are put forward. The first is that confidence intervals be used instead of hypothesis tests whenever possible. The remaining recommendations are relevant if hypothesis tests are used. They are as follows: Define and justify Type I and II error rates a priori; set and justify an effect size a priori; do not confuse p(E | H0) and p(H0 | E); design tests permitting Positive Predictive Value estimation; publish negative results; estimate a priori, not post hoc, power; as warranted by study goals, favor null hypotheses that are not conventional nil hypotheses; and avoid definitive inferences from isolated tests.
Avoidance tests in site-specific risk assessment—influence of soil properties on the avoidance response of collembola and earthworms
Authors: Natal-da-Luz Tiago , Römbke Jörg , Sousa José Paulo
Published: April 2008

The ability of organisms to avoid contaminated soils can act as an indicator of toxic potential in a particular soil. Based on the escape response of earthworms and Collembola, avoidance tests with these soil organisms have great potential as early screening tools in site-specific assessment. These tests are becoming more common in soil ecotoxicology, because they are ecologically relevant and have a shorter duration time compared with standardized soil toxicity tests. The avoidance response of soil invertebrates, however, can be influenced by the soil properties (e.g., organic matter content and texture) that affect behavior of the test species in the exposure matrix. Such an influence could mask a possible effect of the contaminant. Therefore, the effects of soil properties on performance of test species in the exposure media should be considered during risk assessment of contaminated soils. Avoidance tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) were performed to identify the influence of both organic matter content and texture on the avoidance response of representative soil organisms. Distinct artificial soils were prepared by modifying quantities of the standard artificial soil components described by the Organization for Economic Co-operation and Development to achieve different organic matter and texture classes. Several combinations of each factor were tested. Results showed that both properties influenced the avoidance response of organisms, which avoided soils with low organic matter content and fine texture. Springtails were less sensitive to changes in these soil constituents compared with earthworms, indicating springtails can be used for site-specific assessments of contaminated soils with a wider range of respective soil properties.
Effects of estimates from different geochemical models on metal fate predicted by coupled speciation-fate models
Authors: Bhavsar Satyendra P , Gandhi Nilima , Diamond Miriam L , Lock Alan S , Spiers Graeme , de la Torre M. Catalina Alfaro
Published: April 2008

Coupled metal speciation-fate models are an improvement over stand-alone fate-transport models for accurately assessing metal fate and transport. These coupled models estimate fate-controlling partition coefficients using geochemical speciation/complexation models. Commercially available geochemical models are practical options for a two-step, loose coupling with fate-transport models. These models differ in their partitioning estimates because of differences in assumptions, databases, and so on. The present study examines the effects of differences in estimates from geochemical models on estimates of cationic metal fate using two geochemical models: the Windermere humic aqueous model (WHAM) and the minicomputer equilibrium+ model (MINEQL+). The results from each geochemical model were used as input to the fate module of TRANSPEC (a general, coupled metal transport and speciation model). The two versions of the TRANSPEC model were then used to assess the fate of five cationic metals (Cd, Cu, Ni, Pb, and Zn) in Ross Lake (Flin Flon, MB, Canada; alkaline, eutrophic, mine impacted), Kelly Lake (Sudbury, ON, Canada; circumneutral, mesotrophic, mine influenced), and Lake Tantaré (Quebec City, QC, Canada; acidic, oligotrophic, pristine). For relatively soluble metals (Cd, Ni, and Zn), the WHAM and MINEQL+ estimates of speciation/complexation were similar for Ross and Kelly lakes but differed for Lake Tantaré. These differences, however, did not result in significant differences in overall fate estimates. Marked differences were observed between the WHAM and MINEQL+ estimates of partition coefficient, Kd, for more particle-reactive Cu and Pb that translated into the greatest impact on fate in mesotrophic Kelly Lake, in which particle movement is important for fate.
Effects of chronic dietary and waterborne cadmium exposures on the contamination level and reproduction of daphnia magna
Authors: Geffard Olivier , Geffard Alain , Chaumot Arnaud , Vollat Bernard , Alvarez Cathy , Tusseau-Vuillemin Marie-Hélène , Garric Jeanne
Published: April 2008

Regulatory assessments of metal toxicity on freshwater organisms assume that toxic effects are caused by dissolved metals. In aquatic systems, organisms are exposed to both dissolved and particulate-bound metals. In this study, the chronic toxicity of dietary cadmium (Cd) on the reproduction and Cd body burden of Daphnia magna was investigated. Daphnids (<24 h) were successively exposed to dissolved Cd (8 h) and then to uncontaminated or contaminated algae (16 h) for 21 d. The results show a higher Cd burden in daphnids because of the addition of contaminated food and reveal that Cd uptake by D. magna from water and food was additive for the lowest Cd concentrations tested. Similar Cd distributions (cytosolic and insoluble fractions) were observed in the two groups of organisms, showing similar potential toxicity of Cd accumulated from the two exposure routes. Dietary Cd induces deleterious effects on D. magna reproduction. On the basis of Cd body burden of daphnids, the results support the claim that waterborne and dietary Cd exposures were additive in causing toxicity for Cd concentrations lower than 25 μg/L. At the highest Cd concentrations, the importance of dietary Cd on the daphnid contamination level decreases and confounding factors such as feeding rate reduction seem to appear, which induce an effect on neonate reproduction. In this study, we illustrate the need to take the dietary pathway into account in regulatory assessments and to establish effective concentrations with particulate-bound metals.
Spatial covariation of microbial community composition and polycyclic aromatic hydrocarbon concentration in a creosote-polluted soil
Authors: Törneman Niklas , Yang Xiuhong , Bååth Erland , Bengtsson Göran
Published: April 2008

Little is known about the spatial connection between soil microbial community composition and polycyclic aromatic hydrocarbon (PAH) concentration. A spatially explicit survey at a creosote-contaminated site demonstrated that microbial biomass (total concentration of phospholipid fatty acids [PLFAs]) and microbial community composition (PLFA fingerprints) were spatially autocorrelated, mostly within a distance of 25 m, and covaried with PAH concentrations. The concentration of PLFAs indicative of gram-negative bacteria (16:1ω7c, 16:1ω7t, 18:1ω7, cy17:0, and cy19:0) increased in the PAH hot spots, whereas PLFAs representing fungi and gram-positive bacteria (including actinomycetes) were negatively correlated to PAH concentrations. Most PLFAs were spatially autocorrelated, with distances varying between 4 and 25 m. Those PLFAs that increased in PAH-contaminated soil had autocorrelation ranges between 4 and 16 m, whereas the fungal indicator PLFA 18:2ω6,9 had the largest autocorrelation range (25 m). Bacterial strains isolated using a spray-plate technique and with the same PLFA composition as that in contaminated soil samples were capable of degrading phenanthrene, fluoranthene, and pyrene, indicating that the main PAH degraders could be isolated.
Creating metal-spiked bed sediments: A case study from Orewa estuary, New Zealand
Authors: Lu Xueqiang , Bibby Rebecca L , Ford Richard B , Webster-Brown Jenny G
Published: April 2008

Spiking sediments to achieve target concentrations of heavy metal pollutants is a key step in sediment toxicity tests. It is difficult, however, to ensure that metals in an artificially spiked sediment will behave naturally. A method has been developed in the present study to create Cu-, Pb-, and Zn-spiked sediments in which naturally occurring adsorption onto sediment surfaces is the dominant process binding the metals and in which precipitation of readily redissolved minerals and other metal-bearing phases (artifacts of the spiking procedure) are avoided. Uncontaminated bed sediment from an intertidal mudflat in the Orewa estuary, New Zealand, was characterized in terms of existing metal content, optimal adsorption pH, and adsorption capacity. Competitive adsorption between Cu and Pb as well as complexation by seawater anions only slightly affected metal adsorption from seawater. Surface complexation modeling indicated that iron oxide surfaces in the sediment likely were dominating metal adsorption processes. Spiking experiments were designed using these established adsorption characteristics but with significantly higher (>100-fold) concentrations of sediments and dissolved metals and a liquid to solid (L:S) ratio of approximately 5.5. An equilibration time of at least 36 h was required to achieve a reproducible target metal concentration, which could be reliably predicted from the L:S ratio and the initial metal concentration in the spiking solution. Adsorption equilibrium remained the process governing metal binding to the sediment, and no indication was observed that the adsorption capacity of the sediment had been exceeded or that additional metal-bearing phases had been formed.
Biodegradability of highly ethoxylated nonionic surfactants: Determination of intermediates and pathways of biodegradation
Authors: Sparham Chris , Rehman Naheed , Melling Jim , Van Duynhoven John , Marshall Stuart
Published: April 2008

Existing data regarding alcohol ethoxylate (AE) surfactants indicate that structures with greater than 20 ethoxylate (EO) units per molecule or with multibranched alkyl chains may not pass a ready biodegradability test. This could have important consequences for complying with regional regulatory requirements and for the potential risks these chemicals could present to the environment. We investigated the influence of chemical structure on the biodegradability of AEs with different alkyl chain branching and EO content. The AEs investigated were a multibranched AE (average, 18 EO), an oxo-AE (monobranched; average, 23 EO), and a linear AE of oleochemical origin (average, 40 EO). The aims of the present study were to assess the ready biodegradability of AEs with high EO content and to establish the mechanism or pathway by which biodegradation occurs for the oxo-AE. Biodegradation studies were conducted using standard test conditions (International Standards Organization 14593). Solid-phase extraction and liquid chromatography with electrospray mass spectrometry were used to detect profiles in both derivatized and underivatized extracts of samples. Derivatization with phthalic anhydride was used to improve ionization of the lower-ethoxylated AEs and free alcohol that were key indicators in the present study. All AEs were rapidly biodegraded, achieving more than 60% mineralization of parent material. Central fission was the predominant mechanism for the oxo-AE, as confirmed by identification of the oligomeric distribution and quantification of polyethylene glycol released during biodegradation.
Estrogenic activity of lambda-cyhalothrin in the MCF-7 human breast carcinoma cell line
Authors: Zhao Meirong , Zhang Ying , Liu Weiping , Xu Chao , Wang Lumei , Gan Jianying
Published: April 2008

Synthetic pyrethroids are widely used in both agricultural and urban environments for insect control. Lambda-cyhalothrin (LCT) is one of the most common pyrethroids and is used mainly for controlling mosquitoes, fleas, cockroaches, flies, and ants around households. Previous studies have addressed the environmental behaviors and acute toxicities of LCT, but little is known about its chronic toxicity, such as estrogen-like activity. In the present study, the estrogenic potential of LCT was evaluated using the MCF-7 human breast carcinoma cell line. The in vitro E-screen assay showed that 10−7 M LCT could significantly promote MCF-7 cell proliferation, with a relative proliferative effect ratio of 45%. The cell proliferation induced by LCT could be blocked completely, however, by the addition of 10−9 M of the estrogen receptor (ER)-antagonist ICI 182,780. The semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) results showed that the Trefoil factor 1 (pS2) and progesterone receptor gene expression were up-regulated by 10−7 M LCT for 2- and 1.5-fold, respectively. On the other hand, RT-PCR, Western blot analysis, and immunofluorescent assay demonstrated that LCT significantly repressed the mRNA and protein expression levels of ERα and ERβ. These observations indicate that LCT possesses estrogenic properties and may function as a xenoestrogen, likely via a mechanism similar to that of 17β-estradiol. The endocrine-disruption potential of LCT should be considered when assessing the safety of this compound in sensitive environmental compartments.
Dietary accumulation, disposition, and metabolism of technical pentabrominated diphenyl ether (DE-71) in pregnant mink (Mustela vison) and their offspring
Authors: Zhang Si , Bursian Steve , Martin Pamela A , Chan Hing Man , Martin Jonathan W
Published: April 2008

Concentrations of polybrominated diphenyl ethers (PBDEs) in humans and wildlife suggest significant bioaccumulation potential in mammals, but no quantitative biomagnification data from controlled experiments are currently available. As part of a larger study examining the effects of PBDEs on mink (Mustela vison) reproduction and development, we examined congener-specific tissue distribution, maternal transfer, biotransformation, and biomagnification of the technical penta-BDE mixture, DE-71, in farmed mink. Adult female mink were fed one of four concentrations of DE-71 (0-2.5 μg/g) in the diet from breeding through gestation and until weaning at 6 weeks postparturition. Parent PBDEs were measured in tissues and excreta of adult mink, kits, and juveniles, whereas hydroxylated PBDEs (OH-PBDEs) were measured in juveniles only. Similar lipid-normalized concentrations of PBDEs were detected in most tissues of adult mink with the exception of brain, in which concentrations were significantly lower. Kits, however, had a higher proportion of PBDEs in brain compared with adults, presumably because of incomplete development of the blood-brain barrier. Maternal transfer favored lower-brominated PBDE congeners, and the bulk of the body burden in kits at weaning resulted from lactational rather than transplacental transfer. Lipid-normalized, whole-body biomagnification factors ranged from 0.5 to 5.2 for the major congeners and were highest for BDEs 47 and 153. Metabolism clearly limited the biomagnification of some PBDEs, and OH-PBDEs were detectable in plasma, liver, and feces. On a mass basis, OH-PBDEs accounted for 28 to 32% of the excreted fraction, indicating metabolism was an important elimination pathway. Further studies are required to understand the mechanisms of PBDE biotransformation.
Kinetic study of the 2-methyl-3-methoxy-4-phenylbutanoic acid produced by oxidation of microcystin in aqueous solutions
Authors: Wu Xingqiang , Xiao Bangding , Gong Yan , Wang Zhi , Chen Xiaoguo , Li Renhui
Published: April 2008

Microcystins (MCs) are a family of related cyclic hepatotoxic heptapeptides, of which more than 70 types have been identified. The chemically unique nature of the C20 β-amino acid, (2S,3S,8S,9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (Adda), portion of the MCs has been exploited to develop a strategy to analyze the entirety. Oxidation of MCs causes the cleavage of MC Adda to form 2-methyl-3-methoxy-4-phenylbutanoic acid (MMPB). In the present study, we investigated the kinetics of MMPB produced by oxidation of the most-often-studied MC variant, MC-LR (L = leucine, R = arginine), with permanganate-periodate. This investigation allowed insight regarding the influence of the reaction conditions (concentration of the reactants, temperature, and pH) on the conversion rate. The results indicated that the reaction was second order overall and first order with respect to both permanganate and MC-LR. The second-order rate constant ranged from 0.66 to 1.35 M/s at temperatures from 10 to 30°C, and the activation energy was 24.44 kJ/mol. The rates of MMPB production can be accelerated through increasing reaction temperature and oxidant concentration, and sufficient periodate is necessary forthe formation of MMPB. The initial reaction rate under alkaline and neutral conditions is higher than that under acidic conditions, but the former decreases faster than the latter except under weakly acidic conditions. These results provided new insight concerning selection of the permanganate-periodate concentration, pH, and temperature needed for the oxidation of MCs with a high and stable yield of MMPB.
Phosphorus elimination of reclaimed water by different kinds of constructed wetlands
Authors: Li Zifu , Huang Zhaojun , Zhou Lu
Published: April 2008

Because of water shortage in Beijing, most ponds and moats there have not enough water. In some times of each year, there is even no water. Therefore, wastewater reclamation and reuse has been paid more and more attention. Reclaimed water used as scenic water such as to supplement city moats, lakes etc. is considered. In this paper, some experiments were done to investigate whether constructed wetlands can reduce the nitrogen and phosphorus concentration further in order to avoid the eutrophication of water bodies through use of reclaimed water for scenic environment. As we know, phosphorus is an important factor to cause algae bloom directly in water bodies. So investigation on phosphorus elimination is a key object for this study, which is composed of two main parts. The first part is laboratory scale testing to select the appropriate substrates of constructed wetlands among some materials. The second part is pilot scale experiments to find out optimal operational condition of different kinds of constructed wetlands. Based on the lab tests, we found that foamy-brick could provide a good condition for plants and microorganisms. According to the pilot scale experiments, it could be concluded that under optimal operational conditions, horizontal flow wetlands could work well. The results of the experiments also showed that integrated vertical flow wetlands are not suitable for phosphorus elimination of reclaimed water.
Consumer trust and confidence: some recent ideas in the literature
Authors: Fife-Schaw Chris , Barnett Julie , Chenoweth Jonathan , Morrison Gregory M. , Lundéhn Christina
Published: April 2008

This paper reflects on two recent debates in the consumer literature on trust that have implications for consumer relations in the water industry. The first concerns an important yet seldom made distinction between trust and confidence. The second concerns when and how trust is related to acceptance of, for example, new tariffs or new technologies, and it challenges the conventional view that trust is usually a precursor of acceptance. New conceptual models addressing these debates are described and their implications for future water-related consumer research are discussed as are potential implications for industry relationships with consumers.
Central water softening: customer comfort is relevant in new WHO view
Authors: Groenendijk Martijn , van de Wetering Stephan , van Nieuwenhuijze Ruud
Published: April 2008

The effects and implications of the hardness of drinking water have been intensively discussed for some years. Preventive properties have been attributed to calcium and magnesium in connection with cardiovascular disease. More recently the discussion resumed in advance of the new WHO guidelines that will deal with desalination of drinking water obtained from brackish or salt water. The outcome of these discussions will impact on water supply companies that have decided to apply central softening for reasons of customer comfort. This paper describes the strategy adopted by Brabant Water in relation to water softening and customer satisfaction and the significance of the WHO guidelines.
Mathematical Fuzzy Logics
Authors: Gottwald Siegfried
Published: April 2008

The last decade has seen an enormous development in infinite-valued systems and in particular in such systems which have become known as mathematical fuzzy logics.

The paper discusses the mathematical background for the interest in such systems of mathematical fuzzy logics, as well as the most important ones of them. It concentrates on the propositional cases, and mentions the first-order systems more superficially. The main ideas, however, become clear already in this restricted setting.
Sri Lanka: In Peace or in Pieces? A Critical Approach to Peace Education in Sri Lanka
Authors: Cardozo Mieke T.A. Lopes
Published: April 2008

This article seeks to explore the ‘two faces of education’ through a critical analysis of peace education in Sri Lanka. It aims to contribute to the wider debate on the complex role of education in situations of conflict. The article starts with an overview of what peace education is, or should be. This leads to the conclusion that peace education cannot succeed in isolation, and needs to be incorporated in a multilevel process of peacebuilding. Further analysis draws from Bush & Saltarelli's notion of the ‘two faces of education’, combined with Lynn Davies's notion of ‘war education’. These notions help to explain to what extent (peace) education in Sri Lanka contributes to positive or negative conflict, or, in other words, which one of the two ‘faces’ is most prominent. The positive side of education is employed through inter-group encounters, the stimulation of self-esteem and a ‘peaceful school environment’. Through dialogue and understanding, these initiatives stimulate a desegregation of a very segregated school system and society. However, these positive initiatives remain limited. Other, more structural issues, tend to work towards the negative face of education, by fostering segregation, fear and bias rather than counteracting them. These issues form pressing challenges for peace educators and policy makers in Sri Lanka. Critically informed research and evaluation should provide guidelines for well-thought through peace education initiatives, by working towards a combination of critical theory and problem-solving approaches to deliver both critical and hands-on guidelines for further peace education initiatives.
Improved Vascular Engraftment and Graft Function After Inhibition of the Angiostatic Factor Thrombospondin-1 in Mouse Pancreatic Islets
Authors: Olerud Johan , Johansson Magnus , Lawler Jack , Welsh Nils , Carlsson Per-Ola
Published: April 2008

OBJECTIVE—Insufficient development of a new intra-islet capillary network after transplantation may be one contributing factor to the failure of islet grafts in clinical transplantation. The present study tested the hypothesis that the angiostatic factor thrombospondin-1 (TSP-1), which is normally present in islets, restricts intra-islet vascular expansion posttransplantation.

RESEARCH DESIGN AND METHODS—Pancreatic islets of TSP-1–deficient (TSP-1−/−) mice or wild-type islets transfected with siRNA for TSP-1 were transplanted beneath the renal capsule of syngeneic or immunocompromised recipient mice.

RESULTS—Both genetically TSP-1−/− islets and TSP-1 siRNA-transfected islet cells demonstrated an increased vascular density when compared with control islets 1 month after transplantation. This was also reflected in a markedly increased blood perfusion and oxygenation of the grafts. The functional importance of the improved vascular engraftment was analyzed by comparing glucose-stimulated insulin release from islet cells transfected with either TSP-1 siRNA or scramble siRNA before implantation. These experiments showed that the increased revascularization of grafts composed of TSP-1 siRNA-transfected islet cells correlated to increments in both their first and second phase of glucose-stimulated insulin secretion.

CONCLUSIONS—Our findings demonstrate that inhibition of TSP-1 in islets intended for transplantation may be a feasible strategy to improve islet graft revascularization and function.
Human Adenovirus Type 36 Enhances Glucose Uptake in Diabetic and Nondiabetic Human Skeletal Muscle Cells Independent of Insulin Signaling
Authors: Wang Zhong Q. , Cefalu William T. , Zhang Xian H. , Yu Yongmei , Qin Jianhua , Son Leslie , Rogers Pamela M. , Mashtalir Nazar , Bordelon Justin R. , Ye Jianping , Dhurandhar Nikhil V.
Published: April 2008

OBJECTIVE—Human adenovirus type 36 (Ad-36) increases adiposity but improves insulin sensitivity in experimentally infected animals. We determined the ability of Ad-36 to increase glucose uptake by human primary skeletal muscle (HSKM) cells.

RESEARCH DESIGN AND METHODS—The effect of Ad-36 on glucose uptake and cell signaling was determined in HSKM cells obtained from type 2 diabetic and healthy lean subjects. Ad-2, another human adenovirus, was used as a negative control. Gene expression and proteins of GLUT1 and GLUT4 were measured by real-time PCR and Western blotting. Role of insulin and Ras signaling pathways was determined in Ad-36–infected HSKM cells.

RESULTS—Ad-36 and Ad-2 infections were confirmed by the presence of respective viral mRNA and protein expressions. In a dose-dependent manner, Ad-36 significantly increased glucose uptake in diabetic and nondiabetic HSKM cells. Ad-36 increased gene expression and protein abundance of GLUT1 and GLUT4, GLUT4 translocation to plasma membrane, and phosphatidylinositol 3-kinase (PI 3-kinase) activity in an insulin-independent manner. In fact, Ad-36 decreased insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation and IRS-1–and IRS-2–associated PI 3-kinase activities. On the other hand, Ad-36 increased Ras gene expression and protein abundance, and Ras siRNA abrogated Ad-36–induced PI 3-kinase activation, GLUT4 protein abundance, and glucose uptake. These effects were not observed with Ad-2 infection.

CONCLUSIONS—Ad-36 infection increases glucose uptake in HSKM cells via Ras-activated PI 3-kinase pathway in an insulin-independent manner. These findings may provide impetus to exploit the role of Ad-36 proteins as novel therapeutic targets for improving glucose handling.
Clinical Evaluation of the Soft-Start (Pulse-delay) Polymerization Technique in Class I and II Composite Restorations
Authors: Chan D. C. N. , Browning W. D. , Frazier K. B. , Brackett M. G.
Published: April 2008

Clinical Relevance

Class I and II composite restorations placed with a Soft-Start technique showed no significant changes in post-op sensitivity to cold or any decreased signs of marginal stress.
Rime samples characterization and comparison using classical and fuzzy principal components analysis
Authors: Klimaszewska Kamila , Sârbu Costel , Polkowska Żaneta , Błaś Marek , Sobik Mieczysław , Namieśnik Jacek
Published: April 2008

The main objective of this paper is to introduce principal component analysis and two robust fuzzy principal component algorithms as useful tools in characterizing and comparing rime samples collected in different locations in Poland (2004–2007). The efficiency of the applied procedures was illustrated on a data set containing 108 rime samples and concentration of anions, cations, HCHO, as well as pH and conductivity. The fuzzy principal component algorithms achieved better results mainly because they are more compressible than classical PCA and very robust to outliers. For example, a three component model, fuzzy principal component analysis-first component (FPCA-1) accounts for 62.37% of the total variance and fuzzy principal component analysis-orthogonal (FPCA-o) 90.11%; PCA accounts only for 58.30%. The first two principal components explain 51.41% of the total variance in the case of FPCA-1 and 79.59% in the case of FPCA-o as compared to only 47.55% for PCA. As a direct consequence, PCA showed only a partial differentiation of rime samples onto the plane or in the space described by different combination of two or three principal components, whereas a much sharper differentiation of the samples, regarding their origin and location, is observed when FPCAs are applied.
A comparative study of fluorescent singlet oxygen probes in plant leaves
Authors: Hideg Éva
Published: April 2008

Four fluorescent singlet oxygen sensors: DanePy, its oxalate salt, Singlet Oxygen Sensor Green and MVP, were infiltrated into tobacco leaves and tested for toxicity, subcellular localization, light sensitivity and capacity to trap the singlet oxygen produced in photoinhibition. For reference, a broad sensitivity free radical probe, TEMPO-9-AC, was also included. Photochemical yield was approximately 15% and 10% inhibited by Singlet Oxygen Sensor Green and MVP, respectively, but was not significantly affected by the other probes. Under photoinhibitory conditions, brought about by irradiating lincomycin-treated leaves with strong photosynthetically active radiation, DanePy and Singlet Oxygen Sensor Green were responsive. Singlet Oxygen Sensor Green was also reactive to low, non-photoinhibitory light exposure of the leaf, which was not characteristic to the other probes. MVP did not respond to singlet oxygen which can partly be explained by a possible attenuation of its blue emission in the leaf, as shown by the example TEMPO-9-AC. DanePy-oxalate did not respond to photosynthetic singlet oxygen due to lack of its penetration into photosynthetic tissue and hence could be useful in detecting any singlet oxygen which escapes from a chloroplast initiation site. DanePy was localized in the chloroplasts, while Singlet Oxygen Sensor Green was mainly found in the epidermal cells preferentially associated with the nucleus.
Uninvited Guests: The Influence of Teachers’ Roles and Pedagogies on the Positioning of English Language Learners in the Regular Classroom
Authors: Yoon Bogum
Published: April 2008

Grounded in positioning theory, this study examined regular classroom teachers’ views of their roles with regard to English language learners (ELLs) and the relationship between their teaching approaches and the students’ reactions and positioning of themselves in the classroom. Findings suggest that the teachers’ views of their roles varied based on their positioning of themselves as teachers for all students, as teachers for regular education students, or as teachers for a single subject. The teachers’ different approaches were related to the ELLs’ different levels of participation and their positioning of themselves as powerful or powerless students. The study breaks important ground in our understanding of the complex interactional classroom dynamics that influence the teaching and learning of ELLs.
In-Person Visits Before Initiation of Telemedicine for Mental Illness
Authors: Mehrotra Ateev , Busch Alisa B. , Uscher-Pines Lori , Raja Pushpa , Huskamp Haiden A.
Published: April 2024

This cross-sectional study examines how often patients had an in-person visit before initiating telemedicine for mental illness between 2019 and 2022.
Changes in Use of Hepatitis C Direct-Acting Antivirals After Access Restrictions Were Eased by State Medicaid Programs
Authors: Davey Sonya , Costello Kevin , Russo Massimiliano , Davies Suzanne , Lalani Hussain S. , Kesselheim Aaron S. , Rome Benjamin N.
Published: April 2024

Importance

Direct-acting antivirals (DAAs) are safe and highly effective for curing hepatitis C virus (HCV) infection, but their high cost led certain state Medicaid programs to impose coverage restrictions. Since 2015, many of these restrictions have been lifted voluntarily in response to advocacy or because of litigation.

Objective

To estimate how the prescribing of DAAs to Medicaid patients changed after states eased access restrictions.

Design, Setting, and Participants

This modified difference-in-differences analysis of 39 state Medicaid programs included Medicaid beneficiaries who were prescribed a DAA from January 1, 2015, to December 31, 2019. DAA coverage restrictions were measured based on a series of cross-sectional assessments performed from 2014 through 2022 by the US National Viral Hepatitis Roundtable and the Center for Health Law and Policy Innovation.

Exposure

Calendar quarter when states eased or eliminated 3 types of DAA coverage restrictions: limiting treatment to patients with severe liver disease, restricting use among patients with active substance use, and requiring prescriptions to be written by or in consultation with specialists. States with none of these restrictions at baseline were excluded.

Main Outcomes and Measures

Quarterly number of HCV DAA treatment courses per 100 000 Medicaid beneficiaries.

Results

Of 39 states, 7 (18%) eliminated coverage restrictions, 25 (64%) eased restrictions, and 7 (18%) maintained the same restrictions from 2015 to 2019. During this period, the average quarterly use of DAAs increased from 669 to 3601 treatment courses per 100 000 Medicaid beneficiaries. After states eased or eliminated restrictions, the use of DAAs increased by 966 (95% CI, 409-1523) treatment courses per 100 000 Medicaid beneficiaries each quarter compared with states that did not ease or eliminate restrictions.

Conclusions and Relevance

The results of this study suggest that there was greater use of DAAs after states relaxed coverage restrictions related to liver disease severity, sobriety, or prescriber specialty. Further reductions or elimination of these rules may improve access to a highly effective public health intervention for patients with HCV.