bluuebunny/crossref_metadata_2025 huggingface dataset:
Outbreak of colonizations by extended-spectrum β-lactamase-producing Escherichia coli sequence type 131 in a neonatal intensive care unit, Italy
Authors: Giuffrè Mario , Cipolla Domenico , Bonura Celestino , Geraci Daniela Maria , Aleo Aurora , Di Noto Stefania , Nociforo Federica , Corsello Giovanni , Mammina Caterina
Published: March 2013

Background

Extended spectrum β-lactamases (ESBLs) often associated with resistance to aminoglycosides and fluoroquinolones have recently emerged in community-associated Escherichia coli. The worldwide clonal dissemination of E. coli sequence type (ST)131 is playing a prominent role.

We describe an outbreak of colonizations by ESBL-producing E. coli (ESBL-E. coli) in the neonatal intensive care unit (NICU) of the University Hospital, Palermo, Italy.

Methods

An epidemiological investigation was conducted with the support of molecular typing. All children admitted to the NICU and colonized by ESBL-E. coli between January and June 2012, were included in the study. Cases were defined as infants colonized by E. coli resistant to third generation cephalosporins and fluoroquinolones. A case–control study was also performed to identify possible risk factors.

Results

During the outbreak period, 15 infants were found to be colonized by ESBL-E. coli. The epidemic strain demonstrated continuous transmission throughout the outbreak period. Case–control study identified a lower birth weight as the only risk factor for colonization. The strain belonged to the sequence-type 131 community-associated clone. Transmission control interventions, including contact precautions and cohorting, restriction of the new admissions, sanitization of surfaces and equipment and targeted training sessions of the NICU staff, were successful in interrupting the outbreak.

Conclusions

Although invasive infections did not develop in any of the 15 colonized neonates, our report highlights the need to strictly monitor the spill in the NICU setting of multidrug resistant community-associated organisms. Our findings confirm also the role of active surveillance in detecting the silent spread of ESBL-producing Gram negatives in a critical healthcare setting and trigging the implementation of infection control measures. As β-lactam and fluoroquinolone resistant E. coli strains are increasingly spreading in the community, this event could become a more serious challenge.
Broadband extended images by joint inversion of multiple blended wavefields
Authors: Vasconcelos Ivan , Rickett James
Published: March 2013

Estimation of seismic velocities and subsurface reservoir properties in deep, complex, geologic environments calls for the coordination of new acquisition technology with novel depth-domain inversion methods. Here, we propose a method for inversion of subsurface reflectivity image gathers that jointly relies on broadband data acquired by multimeasurement methods (vector-acoustic data; pressure and its gradients) from monopole (pressure) and dipole (e.g., gradient) sources. Our inversion retrieves depth-domain extended images (EIs), which represent the full nonlinear reflectivity operators with pseudosources and pseudoreceivers within the subsurface, as a function of time or frequency. Based on recent advances in interferometry by multidimensional deconvolution (MDD), we present two MDD-based imaging conditions for an EI inversion. One imaging condition consists of deconvolving correlation-based EIs with the so-called joint point-spread function (JPSF). These methods can, in principle, account for imaging primaries as well as internal and free-surface multiples. Because it is based on MDD, our JPSF approach can fully account for blended/simultaneous-source data in imaging with no need to deblend/separate the simultaneous-source data prior to imaging. Using dual-source vector-acoustic data, we describe how the EI JPSF system is constructed by separating source and receiver wavefields from receiver-side upgoing and ghost data, from pressure and gradient sources. With numerical examples, we demonstrate how the method successfully inverts for EIs representing subsurface reflectivity, while benefiting from the increase in temporal and spatial bandwidth brought on by the joint use of dual-source vector-acoustic data. Although here we focus on broadband streamer seismic applications, our joint wavefield inversion approach provides a framework for jointly imaging data from multiple experiments of any kind (e.g., surface and borehole, active and passive) with acoustic, elastic, and electromagnetic fields.
Age Increase of Estrogen Receptor-α (ERα) in Cortical Astrocytes Impairs Neurotrophic Support in Male and Female Rats
Authors: Arimoto Jason M. , Wong Angela , Rozovsky Irina , Lin Sharon W. , Morgan Todd E. , Finch Caleb E.
Published: March 2013

Rodent models show decreased neuronal responses to estradiol (E2) during aging (E2-desensitization) in association with reduced neuronal estrogen receptor (ER)-α, but little is known about age changes of E2-dependent astrocytic neurotrophic support. Because elevated expression of astrocyte glial fibrillary acidic protein (GFAP) is associated with impaired neurotrophic activity and because the GFAP promoter responds to ERα, we investigated the role of astrocytic ERα and ERβ in impaired astrocyte neurotrophic activity during aging. In vivo and in vitro, ERα was increased greater than 50% with age in astrocytes from the cerebral cortex of male rats (24 vs 3 months), whereas ERβ did not change. In astrocytes from 3-month-old males, experimentally increasing the ERα to ERβ ratio induced the aging phenotype of elevated GFAP and impaired E2-dependent neurite outgrowth. In 24-month-old male astrocytes, lowering ERα reversed the age elevation of GFAP and partially restored E2-dependent neurite outgrowth. Mixed glia (astrocytes to microglia, 3:1) of both sexes also showed these age changes. In a model of perimenopause, mixed glia from 9- to 15-month rats showed E2 desensitization: 9-month regular cyclers retained young-like ERα to ERβ ratios and neurotrophic activity, whereas 9-month noncyclers had elevated ERα and GFAP but low E2-dependent neurotrophic activity. In vivo, ERα levels in cortical astrocytes were also elevated. The persisting effects of ovarian acyclicity in vitro are hypothesized to arise from steroidal perturbations during ovarian senescence. These findings suggest that increased astrocyte ERα expression during aging contributes to the E2 desensitization of the neuronal responses in both sexes.
Synthesis and Optical Properties of Some Compounds Based on Carbazole and s-Triazine
Authors: Diao Lixiao , Cui Yuezhi , Li Tianduo , Zhou Longlong , Liu Wenxia
Published: March 2013

A hyperbranched conjugated polymer (P), as well as its repeating units (M), have been synthesized based on 2,4,6-trimethyl-s-triazine and formylcarbazole. Compared with M, P exhibits much stronger fluorescence and a larger Stern–Volmer constant (KSV) in response to DNT, indicating a fluorescence signal amplification effect in the hyperbranched conjugated polymer P.
Tension Tests Behavior of API 5L X60 Pipeline Steel in a Simulated Soil Solution to Evaluate SCC Susceptibility
Authors: Contreras A. , Hernández S. L. , Galvan-Martinez R. , Vega-Becerra O.
Published: March 2013

In this work slow strain rate tests (SSRT) were used for the evaluation of API 5L X60 in contact with a simulated soil solution called NS4 in order to evaluate stress corrosion cracking (SCC) susceptibility. SSRT were carried out in NS4 solution at room temperature to simulate dilute ground water that has been found to be associated with SCC of low carbon steel pipelines. A strain rate of 1x10-6 sec-1 was used. According to the analysis of SSRT results, the X60 pipeline steel is highly resistant to SCC at the conditions studied. A combine fracture type it was observed: ductile and brittle with a transgranular appearance. Some pits close to the fracture zone were observed. The failure process and mechanism of X60 steel in NS4 solution are controlled by anodic dissolution and hydrogen embrittlement which was revealed with the internal cracks observed in the surface fracture. There is a relation between the strength of the steel and the SCC susceptibility, thus, increasing strength in the steel, the SCC susceptibility increases as a function of the pH solution used.
Synthesis of ZnO at Different Atomic Proportion Produced by Chemical Precipitation
Authors: Medina A. , Béjar L. , Herrera-Pérez G.
Published: March 2013

Zinc oxide (ZnO) nanoparticles were produced using chemical precipitation synthesis with a molar ratio of 1:1, 1:2 and 1:3. The structure, chemical composition and morphology were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). XRD and EDS demonstrated that the all particles formed at different atomic proportion were of wurtzite crystal structure with the same chemical composition. SEM and TEM showed the formation of hexagonal particles with a molar ratio of 1:1 while the samples synthesized with a molar ratio 1:2 and 1:3 showed a circular shape. HRTEM and Fast Fourier Transform (FFT) demonstrated that the all particles were formed with a preferable [0001] growth direction.
Junction Operation of GaAs Wire Array Solar Cells
Authors: Halverson Adam F. , Tsakalakos Loucas
Published: March 2013

Wire array solar cells benefit from enhanced coupling of light into the active area of the device, significantly decreased collection lengths due to radial charge separation and collection, and easier access to grain boundaries for passivation which may enable future deposition on non-wafer substrates. We report on an analysis of the junction operation of wire array based GaAs solar cells through temperature and light intensity dependent current-voltage analysis and compare these data to matched planar devices. We see evidence of non-ideal recombination pathways indicated by activation energies for generation-recombination that are significantly less than the band gap of GaAs. We observe voltage shifts in the wire array devices at low temperature and high light intensity that we posit can be explained by electron accumulation in the window layers of the devices.
Passivation, Separation and Characterization of Plasma Synthesized Silicon Nanoparticles
Authors: Cheng Jifang , Jimenez Catherine , Bell Jacob P. , Anderson Ingrid E. , Kendrick Chito , Yang Yongan , Collins Reuben T. , Williams S. Kim R.
Published: March 2013

Silicon nanoparticles (Si NPs) were synthesized by plasma enhanced chemical vapor deposition (PECVD) using silane as a silicon source. Allylamine was used as passivation ligands to form water-soluble Si NPs. Finally, aqueous asymmetric flow field-flow fractionation was used to successfully separate the polydisperse Si NPs into monodisperse Si NP fractions.
The Effect of the Dielectric Constant of a Solution of CdSe Quantum Dots on Electrophoretic Deposition of the Dots
Authors: Smith Nathanael J.
Published: March 2013

The effect on film quality of the dielectric constant εb of the bath solution used for electrophoretic deposition of CdSe quantum dots (QDs) was investigated. Various combinations of solvents yielding different εb were tested, with the best films produced by a bath consisting of hexanes and acetone. Two different types of film were observed, depending on the volume fraction of acetone in the bath: thin, but strongly adhered films for εb < 12 and thick but loose films for εb > 12. This behavior is explained in terms of the rate at which QDs arrive at the surface of the electrode, which depends on the electrophoretic mobility of the QDs and therefore also the dielectric constant of the bath.
Radioiodine therapy in elderly patients with subclinical hyperthyroidism due to non-voluminous nodular goiter and its effect on bone metabolism
Authors: Rosario Pedro Weslley
Published: March 2013

OBJECTIVE: To evaluate 131I therapy in elderly patients with subclinical hyperthyroidism (SCH) due to nodular disease and who did not receive antithyroid drugs (ATDs), and the effect of the treatment on bone metabolism. SUBJECTS AND METHODS: Thirty-six patients with TSH ≤ 0.1 mIU/L and non-voluminous goiter (< 60 cm³) were studied. Bone mineral density (BMD) was assessed in 17 women with osteopenia. RESULTS: Mean 24-h 131I uptake was 17.5%. Symptoms of thyrotoxicosis were reported by two (5.5%) patients in the first week after therapy. One year after radioiodine treatment, SCH was resolved in 30 (83.3%) patients, and hypothyroidism was detected in one (2.7%). In the patients in whom TSH returned to normal, femoral and lumbar spine BMD increased by 1.9% and 1.6%, respectively, in average. CONCLUSIONS: In elderly patients with SCH and non-voluminous goiter, radioiodine not preceded by ATDs is a safe and effective therapeutic alternative. Resolution of SCH has beneficial effects on BMD in postmenopausal women with osteopenia.
Avaliação de políticas ambientais: desafios e perspectivas
Authors: Assis Marcelo Prudente de , Malheiros Tadeu Fabrício , Fernandes Valdir , Philippi Jr Arlindo
Published: March 2013

O presente artigo tem como objetivo contribuir para o debate sobre a inserção da avaliação no ciclo das políticas ambientais no Brasil, discutindo desafios e perspectivas que se apresentam. Para tanto, é feito um resgate histórico da evolução da avaliação, discutindo o conceito, classificação e usos da avaliação e finalmente a avaliação de políticas ambientais, com base nos pressupostos de que ferramentas desenvolvidas para a avaliação de políticas sociais podem ser adaptadas para avaliar políticas ambientais, e ferramentas da área ambiental também podem contribuir para o avanço do campo de estudo. As conclusões mostram que os desafios são grandes, principalmente na obtenção de dados. Em um primeiro momento, talvez não seja possível avaliar impactos de forma ampla, mas é importante avaliar critérios relativos à transparência, equidade e legitimidade, bem como reconstruir as teorias de implementação. O uso automático dos resultados é pouco provável, mas se a avaliação faz parte de um arcabouço mais amplo de melhoria da gestão pública, eles repercutem no aperfeiçoamento das políticas.
A percepção ambiental como instrumento de apoio na gestão e na formulação de políticas públicas ambientais
Authors: Rodrigues Mariana Lima , Malheiros Tadeu Fabrício , Fernandes Valdir , Dagostin Darós Taiane
Published: March 2013

Este artigo insere-se nos estudos de políticas públicas e gestão ambiental municipal. Tem por objetivo discutir como o uso da percepção ambiental pode ser relevante para a gestão ambiental municipal. O caso de estudo escolhido para guiar esta discussão foi o Distrito de Paranapiacaba e Parque Andreense, Município de Santo André-SP. A metodologia utilizada envolveu aplicação de questionário quali-quantitativo junto à população local, buscando coletar a percepção acerca do meio ambiente e de instrumentos da gestão ambiental local. Os resultados indicaram que o uso da percepção da comunidade pode atuar como uma ferramenta de apoio à gestão do meio ambiente, e subsidiar um processo participativo para uma gestão compartilhada entre poder público e sociedade.
A construção da didática no gt Didática - análise de seus referenciais
Authors: Pimenta Selma Garrido , Fusari José Cerchi , Almeida Maria Isabel de , Franco Maria Amélia do Rosário Santoro
Published: March 2013

Ao considerarmos as condições difíceis em que se coloca a escola hoje, a didática tem sido desafiada a encontrar novos espaços de significação. Como agir/pensar didaticamente quando não há condições mínimas para a organização de um espaço/tempo educacional que valorize o ensinar e o aprender? Neste artigo, propusemo-nos a analisar a produção teórica e as pesquisas produzidas nos últimos 20 anos (1988-2008) no Grupo de Trabalho Didática (GT-04) da Associação Nacional de Pós-Graduação e Pesquisa em Educação (ANPEd). Partimos do pressuposto de que, quer como campo teórico, quer como prática social, ela funciona como caixa de ressonância e de reverberação dos desafios que o contexto socioeconômico e político propõe à tarefa educativa. Observamos no conjunto dos trabalhos analisados uma certa dispersão epistemológica e de paradigmas nas pesquisas da área. As pesquisas realizadas reafirmam quatro focos de análise: as práticas docentes; os contextos da prática; as mediações entre ensino e aprendizagem e as pesquisas de cunho epistemológico.
Literacia e pensamento crítico: um referencial para a educação em ciências e em matemática
Authors: Tenreiro-Vieira Celina , Vieira Rui Marques
Published: March 2013

É hoje amplamente defendida uma educação em ciências e em matemática, numa perspectiva de literacia, que habilite cada um a contribuir para a melhoria da qualidade de vida de todos e um ambiente sustentável para as gerações atuais e futuras. Nessa linha, em conjugação com o facto de o pensamento crítico emergir como proeminente e estreitamente ligado à literacia científica e matemática, o presente artigo centra-se em estudos desenvolvidos pelos autores com a finalidade de conferir clareza e inteligibilidade a esse campo, estabelecendo um referencial que possa ser usado para orientar a formação de professores e a educação em ciências e em matemática das crianças e jovens. O referencial aqui apresentado configura-se como um suporte à construção de ideias claras acerca de literacia científica, literacia matemática e pensamento crítico, passíveis de serem congruentemente plasmadas no desenvolvimento de materiais didáticos e de práticas pedagógico-didáticas intencional e fundamentadamente orientadas para o promover da literacia crítica dos alunos.
A escrita acadêmica: do excessivo ao razoável
Authors: Pereira Marcos Villela
Published: March 2013

O artigo propõe uma reflexão pontual sobre a natureza da escrita, colocando em análise procedimentos argumentativos, enunciativos e dispositivos de produção de regimes de verdade no interior de textos acadêmicos. Discute a tensão entre escritor e leitor, constituindo a escrita como um campo turbulento de disputa e negociação de sentidos e significados de modo que a mútua interpelação produza deslocamentos na direção da constituição do sujeito escritor e do sujeito leitor. Apresenta uma revisão de estilos de escrita acadêmica, apontando potencialidades e fragilidades, destacando-se os riscos que o exagero e o excesso podem produzir nos efeitos de apreensão e compreensão do conteúdo. Propõe, a modo conclusivo, a ponderação e a plausibilidade como estratégias de estabelecimento de uma medida do que seja o razoável no interior da cultura acadêmica.
Entre o texto e a vida: uma leitura sobre as políticas de educação especial
Authors: Vasques Carla K. , Moschen Simone , Gurski Roselene
Published: March 2013

À margem da agenda política do Estado, a educação especial tradicionalmente se organizou como atendimento educacional especializado substitutivo ao ensino comum, em classes e escolas especiais. Nas últimas décadas, o Brasil, em consonância com movimentos internacionais, estabeleceu uma série de leis, políticas e programas para combater as desigualdades e a exclusão escolar. Nesse movimento, sujeitos com transtornos globais do desenvolvimento (TGD), tradicionalmente apartados dos processos de escolarização, são recebidos nas salas de aula e no velho pátio da escola. Quais racionalidades sustentam as formas de nomear e identificar esses alunos? Como compreender as relações entre os diagnósticos, as políticas e a inscrição das (im)possibilidades escolares? Em que medida as políticas inclusivas de educação especial desconstroem sentidos que relacionam os TGD à ineducabilidade, ou, ainda, a diferença à anormalidade e à inferioridade? O presente ensaio discute a implementação das diretrizes inclusivas considerando o texto político e seus efeitos no contexto da prática. A hermenêutica filosófica oferece os tempos e os focos da leitura. O argumento é tecido com e a partir das falas de um aluno e de professores, em diferentes campos de pesquisa. Do texto à vida, o incremento das matrículas; a proliferação dos sentidos sobre esses alunos e as possibilidades escolares; a atualização de antigos impasses perante o novo, o diferente. Se, no âmbito dos princípios, são reconhecidas a igualdade e as diferenças, na concretude das escolas ainda persiste a noção do diferente como desigual. Da inclusão ao pertencimento, aposta-se no diálogo como valoração da alteridade e condição de pertença.
Como os indivíduos se tornam indivíduos? Entrevista com Danilo Martuccelli
Authors: Setton Maria da Graça Jacintho , Sposito Marilia Pontes
Published: March 2013

O objetivo desta entrevista é oferecer subsídios para o debate acerca dos desafios epistemológicos atuais da sociologia. Trata-se de uma rara oportunidade de dar voz a um pesquisador que mesmo se ocupando de temas europeus e específicos da realidade francesa, não deixa de ter um envolvimento com a realidade latino-americana. A entrevista concedida por Danilo Martuccelli, em outubro de 2012, foi realizada pelas professoras de sociologia da educação da Faculdade de Educação da Universidade de São Paulo, Maria da Graça Jacintho Setton e Marilia Pontes Sposito, a partir de um debate informal e cordial realizado ora por e-mail, ora presencialmente. Danilo Martuccelli é professor de sociologia da Faculdade de Ciências Humanas e Sociais da Universidade Paris-Descartes (Sorbonne). É também membro do grupo de pesquisa CERLIS (Centre de recherches sur les liens sociaux), que pertence à mesma instituição. Nesta entrevista temos a exposição de um instrumental teórico e analítico que evidencia a integração das perspectivas micro e macrossociológica. Aproveitando-se de uma sólida leitura dos clássicos da sociologia a partir de um enfoque grupal ou individual, Danilo Martuccelli oferece um relato inspirador de como podemos nos apropriar de uma larga tradição teórica. Fazendo uso dessas reflexões, o depoimento põe em tela um debate contemporâneo no interior das ciências sociais, bem como garante a ampliação e a contextualização histórica e teórica dos processos de formação do social.
Efeito da substituição de cloreto de sódio por cloreto de potássio em pão francês
Authors: Ignácio Ana Karoline Ferreira , Rodrigues José Tarcísio de Domenico , Niizu Patrícia Yuasa , Chang Yoon Kil , Stell Caroline Joy
Published: March 2013

Há uma tendência mundial de redução de sódio nos alimentos industrializados, em função da sua relação com o aumento da pressão arterial. Na medida em que o pão francês é um dos alimentos que mais contribuem para a ingestão de sódio pela população brasileira, o objetivo desta pesquisa foi avaliar a substituição do cloreto de sódio (NaCl) por cloreto de potássio (KCl) neste produto, como forma de atender a essa tendência. Foram avaliadas quatro formulações: a padrão (FP) com 2% de NaCl e a substituição desta porcentagem por KCl em 30% (F1) e 50% (F2), além de uma formulação com 0% de cloreto de sódio (F3), equivalendo os valores de sódio a 307, 234, 176,5 e 4,5 mg em uma unidade de 50 g de pão francês, respectivamente. Todas as reduções atendem à previsão recomendada pela ANVISA para 2014. A farinha de trigo utilizada foi caracterizada por composição centesimal, com determinação dos teores e índice de glúten, extensografia e farinografia, comprovando ser adequada para panificação. As características reológicas da massa com soluções salinas nas mesmas concentrações das formulações foram avaliadas usando-se extensógrafo. Os pães foram avaliados pelos parâmetros de volume específico e teores de sódio e potássio, além de serem submetidos a teste de aceitação com 53 consumidores de pães. A redução da dosagem do sódio não alterou significativamente o volume específico dos pães. Na análise sensorial, até a redução de 30% do sal em relação ao padrão de 2%, não foi possível diferenciar os pães pelos atributos avaliados. Já a formulação com 50% de substituição apresentou pior sabor em relação ao padrão, mas obteve uma nota de aceitação equivalente a "gostei ligeiramente". A formulação sem adição de cloreto de sódio diferiu significativamente de todas as demais no quesito sabor, o que ocasionou a pior aceitação. Os resultados comprovaram a viabilidade tecnológica de se produzir pão francês com até 30% de redução de sal (1,4% na formulação comercial), o que proporcionaria pães com a quantidade de sódio proposta para atender aos limites estabelecidos (234 mg.50 g-1), em relação a uma formulação padrão de 2% de sal (base farinha).
Plantas vasculares das áreas alagadas dos Marimbus, Chapada Diamantina, BA, Brasil
Authors: França Flávio , Melo Efigênia de , Oliveira Ivania Batista de , Reis Alessandra Terezinha Chaves Cotrim , Alves Gérson Limoeiro , Costa Milena Ferreira
Published: March 2013

As plantas vasculares de áreas alagadas são importantes componentes dos ecossistemas tropicais, embora pouco estudadas no Nordeste brasileiro. Este trabalho pretende registrar as plantas vasculares das áreas alagadas dos Marimbus na Chapada Diamantina, Bahia, discutindo aspectos de distribuição geográfica e espectro biológico, como também comparando com outros levantamentos em áreas alagadas. Foram reconhecidas 130 espécies em 46 famílias. A família Cyperaceae foi a mais rica (15%), seguida por Rubiaceae (10%), Poaceae (8%), Myrtaceae (7,6%), Leguminosae (6,8%) e Polygonaceae (3,8%). As anfíbias são as mais comuns (58%), as emergentes, flutuantes (fixas e livres) e submersas, constituem 39% da flora, que apresenta 25% de nanofanerófitas, 13% de geófitas e 12% de microfanerófitas. A maioria das espécies apresenta distribuição neotropical (34%), muitas são ruderais (17%) e outras são multicontinentais (9%). A flora mostrou-se menos dissimilar da flora do Pantanal matogrossense.
Germinação e crescimento in vitro de Cattleya bicolor Lindley (Orchidaceae)
Authors: Suzuki Rogério Mamoru , Almeida Vanessa de , Pescador Rosete , Ferreira Wagner de Melo
Published: March 2013

A germinação de sementes de orquídeas in vitro vem sendo utilizada desde o início do século passado. Apesar disso, o conhecimento disponível a respeito da composição nutricional dos meios de cultura que favorecem a germinação e o crescimento in vitro de orquídeas ainda é bastante escasso. Diante da ameaça de extinção da Cattleya bicolor e devido à escassez de conhecimento a respeito da germinação e do crescimento in vitro dessa espécie, este trabalho teve como objetivo avaliar a influência do meio de cultura na germinação in vitro de suas sementes, no desenvolvimento inicial dos protocormos até a formação das plântulas, bem como avaliar o crescimento das plântulas até os primeiros doze meses de cultivo in vitro. Os resultados mostraram que o meio de cultura ideal para a germinação in vitro das sementes e para o desenvolvimento inicial das plântulas de Cattleya bicolor é o de Vacin & Went. Recomenda-se que após seis meses de cultivo as plântulas sejam transferidas para o meio MS ou VW, que promovem o desenvolvimento das plântulas, e mantê-las em um destes meios de cultura até o início da aclimatização. Tais informações são de grande importância para a otimização do processo de propagação das espécies de orquídeas nativas do Brasil.
Trilhas podem influenciar a composição florística e a diversidade de epífitas na Floresta Atlântica?
Authors: Santos Ana Carolina Laurenti dos , Melo Maria Margarida da Rocha Fiuza de , Eisenlohr Pedro Vasconcellos
Published: March 2013

Um tipo de efeito de borda ainda pouco explorado é aquele exercido por trilhas. Testamos a hipótese de que áreas a diferentes distâncias de uma trilha em um fragmento de Mata Atlântica em São Paulo difeririam em relação à composição e diversidade de espécies de epífitas vasculares. Instalamos 20 parcelas de 2 × 50 m para marcar os forófitos nos quais seria feito o levantamento das epífitas. Diferenças na composição florística entre as áreas mais próximas e mais distantes da trilha não foram suficientes para agrupar as parcelas de cada área de forma coesa pela análise de ordenação NMDS. A diversidade (riqueza e equabilidade) de espécies mostrou-se também similar. Parece que o impacto causado pela trilha não seria suficiente para influenciar essa comunidade epifítica, o que pode ser devido a outros fatores ambientais que estariam atuando no trecho investigado ou simplesmente porque as epífitas não responderiam a um efeito de borda como o de trilhas.
Caracterização morfológica de fungos conidiais decompositores de folhedo provenientes de Cubatão, SP, Brasil
Authors: Grandi Rosely Ana Piccolo , Silva Priscila da
Published: March 2013

Este artigo apresenta seis fungos conidiais isolados de folhedo misto coletado no município de Cubatão, estado de São Paulo, Brasil. O folhedo passou pela técnica de lavagem sucessiva e incubação dos detritos em câmaras-úmidas. Os fungos foram montados em lâminas permanentes e encontram-se depositados no Herbário SP. Os hifomicetos Dendryphion comosum Wall., Graphium calicioides (Fr.) Cooke & Massee, Mycoleptodiscus disciformis Matsush., Periconia igniaria E.W. Mason & M.B. Ellis, Polyschema olivaceum (Ellis & Everh.) M.B. Ellis e Rhexoacrodictys erecta (Ellis & Everh.) W.A. Baker & Morgan-Jones são descritos e ilustrados pela primeira vez para o Brasil.
Regional Earthquake Likelihood Models I: First-Order Results
Authors: Zechar J. Douglas , Schorlemmer Danijel , Werner Maximilian J. , Gerstenberger Matthew C. , Rhoades David A. , Jordan Thomas H.
Published: March 2013

The Regional Earthquake Likelihood Models (RELM) working group designed a 5-year experiment to forecast the number, spatial distribution, and magnitude distribution of subsequent target earthquakes, defined to be those with magnitude ≥4.95 (M 4.95+) in a well-defined California testing region. Included in the experiment specification were the description of the data source, the methods for data processing, and the proposed evaluation metrics. The RELM experiment began on 1 January 2006 and involved 17 time-invariant forecasts constructed by seismicity modelers; by the end of the experiment on 1 January 2011, 31 target earthquakes had occurred. We analyze the experiment outcome by applying the proposed consistency tests based on likelihood measures and additional comparison tests based on a measure of information gain. We find that the smoothed seismicity forecast by Helmstetter et al., 2007 based on M 2+ earthquakes since 1981, is the best forecast, regardless of whether aftershocks are included in the analysis. The RELM experiment has helped to clarify ideas about testing that can be applied to more wide-ranging earthquake forecasting experiments conducted by the Collaboratory for the Study of Earthquake Predictability (CSEP).

Online Material: Figures and tables showing the RELM testing region and collection region definitions, numerical results associated with the RELM experiment, and the uncorrected forecast by Ebel et al. (2007).
Geographic variation in marine invasions among large estuaries: effects of ships and time
Authors: Ruiz Gregory M. , Fofonoff Paul W. , Ashton Gail , Minton Mark S. , Miller A. Whitman
Published: March 2013

Coastal regions exhibit strong geographic patterns of nonnative species richness. Most invasions in marine ecosystems are known from bays and estuaries, where ship‐mediated transfers (on hulls or in ballasted materials) have been a dominant vector of species introductions. Conspicuous spatial differences in nonnative species richness exist among bays, but the quantitative relationship between invasion magnitude and shipping activity across sites is largely unexplored. Using data on marine invasions (for invertebrates and algae) and commercial shipping across 16 large bays in the United States, we estimated (1) geographic variation in nonnative species richness attributed to ships, controlling for effects of salinity and other vectors, (2) changes through time in geographic variation of these ship‐mediated invasions, and (3) effects of commercial ship traffic and ballast water discharge magnitude on nonnative species richness. For all nonnative species together (regardless of vector, salinity, or time period), species richness differed among U.S. coasts, being significantly greater for Pacific Coast bays than Atlantic or Gulf Coast bays. This difference also existed when considering only species attributed to shipping (or ballast water), controlling for time and salinity. Variation in nonnative species richness among Pacific Coast bays was strongly affected by these same criteria. San Francisco Bay, California, had over 200 documented nonnative species, more than twice that reported for other bays, but many species were associated with other (non‐shipping) vectors or the extensive low‐salinity habitats (unavailable in some bays). When considering only ship‐ or ballast‐mediated introductions in high‐salinity waters, the rate of newly detected invasions in San Francisco Bay has converged increasingly through time on that for other Pacific Coast bays, appearing no different since 1982. Considering all 16 bays together, there was no relationship between either (1) number of ship arrivals (from foreign ports) and number of introductions attributed to ships since 1982 or (2) volume of foreign ballast water discharge and number of species attributed to ballast water since 1982. These shipping measures are likely poor proxies for propagule supply, although they are sometimes used as such, highlighting a fundamental gap in data needed to evaluate invasion dynamics and management strategies.
Beyond best management practices: pelagic biogeochemical dynamics in urban stormwater ponds
Authors: Williams Clayton J. , Frost Paul C. , Xenopoulos Marguerite A.
Published: March 2013

Urban stormwater ponds are considered to be a best management practice for flood control and the protection of downstream aquatic ecosystems from excess suspended solids and other contaminants. Following this, urban ponds are assumed to operate as unreactive settling basins, whereby their overall effectiveness in water treatment is strictly controlled by physical processes. However, pelagic microbial biogeochemical dynamics could be significant contributors to nutrient and carbon cycling in these small, constructed aquatic systems. In the present study, we examined pelagic biogeochemical dynamics in 26 stormwater ponds located in southern Ontario, Canada, during late summer. Initially, we tested to see if total suspended solids (TSS) concentration, which provides a measure of catchment disturbance, landscape stability, and pond performance, could be used as an indirect predictor of plankton stocks in stormwater ponds. Structural equation modeling (SEM) using TSS as a surrogate for external loading suggested that TSS was an imperfect predictor. TSS masked plankton–nutrient relationships and appeared to reflect autochthonous production moreso than external forces. When TSS was excluded, the SEM model explained a large amount of the variation in dissolved organic matter (DOM) characteristics (55–75%) but a small amount of the variation in plankton stocks (3–38%). Plankton stocks were correlated positively with particulate nutrients and extracellular enzyme activities, suggesting rapid recycling of the fixed nutrient and carbon pool with consequential effects on DOM. DOM characteristics across the ponds were mainly of autochthonous origin. Humic matter from the watershed formed a larger part of the DOM pool only in ponds with low productivity and low dissolved organic carbon concentrations. Our results suggest that in these small, high nutrient systems internal processes might outweigh the impact of the landscape on carbon cycles. Hence, the overall benefit that constructed ponds serve to protect downstream environments must be weighed with the biogeochemical processes that take place within the water body, which could offset pond water quality gains by supporting intense microbial metabolism. Finally, TSS did not provide a useful indication of stormwater pond biogeochemistry and was biased by autochthonous production, which could lead to erroneous TSS‐based management conclusions regarding pond performance.
Fire‐mediated pathways of stand development in Douglas‐fir/western hemlock forests of the Pacific Northwest, USA
Authors: Tepley Alan J. , Swanson Frederick J. , Spies Thomas A.
Published: March 2013

Forests dominated by Douglas‐fir and western hemlock in the Pacific Northwest of the United States have strongly influenced concepts and policy concerning old‐growth forest conservation. Despite the attention to their old‐growth characteristics, a tendency remains to view their disturbance ecology in relatively simple terms, emphasizing infrequent, stand‐replacing (SR) fire and an associated linear pathway toward development of those old‐growth characteristics. This study uses forest stand‐ and age‐structure data from 124 stands in the central western Cascades of Oregon to construct a conceptual model of stand development under the mixed‐severity fire regime that has operated extensively in this region. Hierarchical clustering of variables describing the age distributions of shade‐intolerant and shade‐tolerant species identified six groups, representing different influences of fire frequency and severity on stand development. Douglas‐fir trees >400 years old were found in 84% of stands, yet only 18% of these stands (15% overall) lack evidence of fire since the establishment of these old trees, whereas 73% of all stands show evidence of at least one non‐stand‐replacing (NSR) fire. Differences in fire frequency and severity have contributed to multiple development pathways and associated variation in contemporary stand structure and the successional roles of the major tree species. Shade‐intolerant species form a single cohort following SR fire, or up to four cohorts per stand in response to recurring NSR fires that left living trees at densities up to 45 trees/ha. Where the surviving trees persist at densities of 60–65 trees/ha, the postfire cohort is composed only of shade‐tolerant species. This study reveals that fire history and the development of old‐growth forests in this region are more complex than characterized in current stand‐development models, with important implications for maintaining existing old‐growth forests and restoring stands subject to timber management.
Diabetes‐Associated Periodontitis Molecular Features in Infrared Spectra of Gingival Crevicular Fluid
Authors: Xiang Xiaoming , Duarte Poliana Mendes , Lima Jadson Almeida , Santos Vanessa Renata , Gonçalves Tiago Dias , Miranda Tamires Szeremeske , Liu Kan‐Zhi
Published: March 2013

Background: It has been established previously that infrared spectroscopy (IRS) can be used to identify periodontitis‐specific molecular signatures in gingival crevicular fluid (GCF) and to confirm clinical diagnoses. This follow‐up study is designed to assess whether this novel technique is also able to differentiate diseased from healthy sites in patients with diabetes mellitus (DM) by analyzing the molecular fingerprints embedded in the GCF.

Methods: A total of 65 patients with DM with moderate‐to‐severe chronic periodontitis (CP) was recruited, and 15 individuals without DM (65 sites) without periodontal diseases were used as control. Clinical examination and GCF samples were taken from a total of 351 sites, including periodontitis (109), gingivitis (115), and healthy (127) sites. Corresponding absorption spectra of GCF samples were acquired and processed, and the relative contributions of key functional groups in the infrared spectra were identified and analyzed. The qualitative assessment of clinical relevance of these GCF spectra was interpreted with multivariate statistical analysis: linear discriminant analysis (LDA).

Results: Spectral analysis revealed several molecular signatures representing vibrations in protein (amide I and II), lipid ester, and sugar moieties in the GCF of patients with DM with CP and non‐DM controls. The diagnostic accuracy for distinction between healthy and CP sites in patients with DM determined by LDA of GCF spectra was 95.3% for the training set of samples and 87.5% for the validation set. Additional LDA of GCF spectra from healthy sites of non‐DM controls and patients with DM revealed 100% diagnostic accuracy for the training set and 86.7% for the validation set. The regions robotically selected by LDA for the two analyses were slightly different in that first LDA identified major regions clustered with the side chain vibrations originating from protein and DNA contents, whereas the second was predominantly the glycation and protein components.

Conclusion: IRS is a feasible method to differentiate disease‐specific molecular signatures in GCF in the presence of DM and to generate a complex biochemical profile of GCF to identify DM‐specific spectral features.
Interrupting the Politics of Learning
Authors: Biesta Gert
Published: March 2013

In this article, the author raises critical questions about the notion of ‘learning’, the language of ‘learning’ and the discourse of ‘learning’. The analytical and critical device used is the idea of the ‘politics of learning’, through which the author highlights the powerful work that is being done by, and which at the very same time is hidden behind, the discourse of ‘learning’. The author focuses on the field of lifelong learning, not only because it is here that claims about and demands for learning are most explicitly articulated, but also because this field, through both policy and research, is contributing most strongly to an apparent ‘common sense’ about learning in contemporary societies. Based on this analysis, the author argues that there is a need for an interruption of the politics of learning in order to reclaim the emancipatory potential of education.
“Deficiency” of Mitochondria in Muscle Does Not Cause Insulin Resistance
Authors: Holloszy John O.
Published: March 2013

Based on evidence that patients with type 2 diabetes (T2DM), obese insulin-resistant individuals, and lean insulin-resistant offspring of parents with T2DM have ∼30% less mitochondria in their muscles than lean control subjects, it appears to be widely accepted that mitochondrial “deficiency” is responsible for insulin resistance. The proposed mechanism for this effect is an impaired ability to oxidize fat, resulting in lipid accumulation in muscle. The purpose of this counterpoint article is to review the evidence against the mitochondrial deficiency concept. This evidence includes the findings that 1) development of insulin resistance in laboratory rodents fed high-fat diets occurs despite a concomitant increase in muscle mitochondria; 2) mitochondrial deficiency severe enough to impair fat oxidation in resting muscle causes an increase, not a decrease, in insulin action; and 3) most of the studies comparing fat oxidation in insulin-sensitive and insulin-resistant individuals have shown that fat oxidation is higher in T2DM patients and obese insulin-resistant individuals than in insulin-sensitive control subjects. In conclusion, it seems clear, based on this evidence, that the 30% reduction in muscle content of mitochondria in patients with T2DM is not responsible for insulin resistance.
Mitochondrial Deficiency Is Associated With Insulin Resistance
Authors: Goodpaster Bret H.
Published: March 2013

The specific cellular underpinnings or mechanisms of insulin resistance (IR) are not clear. Here I present evidence to support a causal association between mitochondrial energetics and IR. A large body of literature indicates that mitochondrial capacity for oxidative metabolism is lower in human obesity and type 2 diabetes. Whether or not mitochondria play a causal role in IR is hotly debated. First, IR can be caused by many factors, many of which may or may not involve mitochondria. These include lipid overload, oxidative stress, and inflammation. Thus the first tenet of an argument supporting a role for mitochondria in IR is that mitochondria derangements can cause IR, but IR does not have to involve mitochondria. The second tenet of this argument is that animal models in which oxidative metabolism are completely abolished are not always physiologically or pathologically relevant to human IR, in which small metabolic perturbations can have profound effects over a prolonged period. Lastly, mitochondria are complex organelles, with diverse functions, including links with cell signaling, oxidative stress, and inflammation, which in turn can be connected with IR. In summary, mitochondrial “deficiency” is not merely a reduced energy generation or low fatty acid oxidation; this concept should be expanded to numerous additional important functions, many of which can cause IR if perturbed.
Circulating Lysophosphatidylcholines Are Markers of a Metabolically Benign Nonalcoholic Fatty Liver
Authors: Lehmann Rainer , Franken Holger , Dammeier Sascha , Rosenbaum Lars , Kantartzis Konstantinos , Peter Andreas , Zell Andreas , Adam Patrick , Li Jia , Xu Guowang , Königsrainer Alfred , Machann Jürgen , Schick Fritz , Hrabé de Angelis Martin , Schwab Matthias , Staiger Harald , Schleicher Erwin , Gastaldelli Amalia , Fritsche Andreas , Häring Hans-Ulrich , Stefan Norbert
Published: March 2013

OBJECTIVE

Nonalcoholic fatty liver (NAFL) is thought to contribute to insulin resistance and its metabolic complications. However, some individuals with NAFL remain insulin sensitive. Mechanisms involved in the susceptibility to develop insulin resistance in humans with NAFL are largely unknown. We investigated circulating markers and mechanisms of a metabolically benign and malignant NAFL by applying a metabolomic approach.

RESEARCH DESIGN AND METHODS

A total of 265 metabolites were analyzed before and after a 9-month lifestyle intervention in plasma from 20 insulin-sensitive and 20 insulin-resistant subjects with NAFL. The relevant plasma metabolites were then tested for relationships with insulin sensitivity in 17 subjects without NAFL and in plasma from 29 subjects with liver tissue samples.

RESULTS

The best separation of the insulin-sensitive from the insulin-resistant NAFL group was achieved by a metabolite pattern including the branched-chain amino acids leucine and isoleucine, ornithine, the acylcarnitines C3:0-, C16:0-, and C18:0-carnitine, and lysophosphatidylcholine (lyso-PC) C16:0 (area under the ROC curve, 0.77 [P = 0.00023] at baseline and 0.80 [P = 0.000019] at follow-up). Among the individual metabolites, predominantly higher levels of lyso-PC C16:0, both at baseline (P = 0.0039) and at follow-up (P = 0.001), were found in the insulin-sensitive compared with the insulin-resistant subjects. In the non-NAFL groups, no differences in lyso-PC C16:0 levels were found between the insulin-sensitive and insulin-resistant subjects, and these relationships were replicated in plasma from subjects with liver tissue samples.

CONCLUSIONS

From a plasma metabolomic pattern, particularly lyso-PCs are able to separate metabolically benign from malignant NAFL in humans and may highlight important pathways in the pathogenesis of fatty liver–induced insulin resistance.