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Transporte de fósforo na enxurrada superficial em função do tipo de fonte de P e intensidade das chuvas: Relevância à gerência ambiental em sistemas de produção brasileiros; Phosphorus transport in surface runoff as a function of P source type and rainfall intensity: Relevance to environmental management of Brazilian production systems

Shigaki, Francirose
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/09/2006 PT
Relevância na Pesquisa
35.49%
Estima-se que a água potável no futuro será limitada devido a: (1) problemas ambientais, (2) aumento na demanda (a população mundial deve atingir 10,5 bilhões de habitantes em 2050); e (3) 60% do consumo mundial é baseado em recursos não renováveis. Conseqüentemente, é imperativo que os recursos de águas doces sejam cuidadosamente manejados para assegurar seu uso para as gerações futuras. Um dos principais problemas ambientais que limita o uso da água é a eutrofização, que pode ser acelerada por entradas de nitrogênio (N) e fósforo (P). Como resultado, a minimização das perdas de P para as águas é essencial para diminuição da incidência e severidade da eutrofização. Entretanto, suplementos adequados de P são necessários para produção de culturas de interesse econômico na maioria das vezes dependentes de suplementação adequada de P do solo. Sendo assim, o P é adicionado rotineiramente para melhores rendimentos de todas as culturas. A maioria dos fertilizantes fosfatados utilizados na agricultura são altamente solúveis em água, afim de fornecer P prontamente disponível para absorção das plantas. Entretanto, uma alta proporção desse fósforo aplicado torna-se indisponível devido as reações químicas dos constituintes do solo (fixação). Fertilizantes fosfatados com alta solubilidade em água tendem a dissolver-se rapidamente...

Locativos e sintagmas preposicionados no português quatrocentista: um estudo do movimento; Locatives and PPs in 15th century portuguese language: a movement research

Mendes, Jaqueline Massagardi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/06/2009 PT
Relevância na Pesquisa
65.72%
Nesta tese estudamos o movimento de sintagmas preposicionados (PPs), pronomes locativos (Locs) e pronomes locativos preposicionados (LocPs) em estruturas encaixadas do português quatrocentista, admitindo que esse período acomode variações que apontam para uma competição de gramáticas na linha de Kroch (1989, 1994, 2003). Assumimos com Martins (1994), Muidine (2000) e Moraes de Castilho (2005), que os pronomes locativos hi e ende tenham coexistido com os PPs, mas foram suplantados por estes últimos a partir do séc.XV. Tomando-se como corpus representativo do português quatrocentista a Crônica do Conde Dom Pedro de Menezes de Zurara, de fato atestamos PPs convivendo com pronomes locativos nos mesmos contextos sintáticos e inclusive os redobrando. As estruturas de redobro de um locativo por um PP mostraram-se relevantes por indicar a especialização das posições desses elementos. Fazemos uso de duas linhas teóricas, conforme proposta de Kato e Tarallo (1989): um modelo mais formal como a Teoria de Princípios e Parâmetros (Chomsky, 1986) e um de cunho variacionista como a Sociolinguística Laboviana, Para uma análise descritiva dos dados, seguimos a metodologia da Sociolingüística Quantitativa, pontuando fatores lingüísticos condicionadores da posição desses constituintes. De modo geral...

O discurso pedagógico na modernidade: uma escuta psicanalítica do emprego de slogans e jargões no contexto escolar; The pedagogical discourse of modernity: a psychoanalytic listening of the use of slogans and jargon in the school context

Siqueira, Flávia Zanni
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/09/2012 PT
Relevância na Pesquisa
35.49%
Nesta pesquisa, propomos um exame do discurso pedagógico e de seus recursos linguísticos constituintes (sloganse jargões), desde sua formulaçãopela Secretaria de Estado da Educação de São Paulo, até a atribuição de sentido prático numa unidade da rede estadual, feita por seus agentes educativos (professores, coordenadores, diretores). Nosso intuito é compreender os modos de adesão desses agentes ao discurso oficial, em seus aspectos de conformidade e de resistência. No que diz respeito à autoridade pública,interessam-nos os documentos referentes àproposta curricular de São Paulo(vigentesdesde 2008), entendidos como representantes concretos da política públicaeducacional do Estado. Em sua configuração particular, importa-nos a construção de propostas de ação, apreendidas a partir do discurso dos agentes de uma escola, em reuniões de equipe (Horas de Trabalho Pedagógico Coletivo HTPC).Para tanto, propomos analisar o material divulgado pelo órgão do Estado e os dados da pesquisa de campo à luz dos escritos freudianos acerca dos mecanismos psíquicos de funcionamento de grupos e das contribuições lacanianassobre ateoria dos discursos, procurando evidenciar as características da circulação e da reprodução dos discursos pedagógicos e de seus recursos linguísticos.A partir de sua teoria da libido...

Tempos e espaços vividos : a produtividade das configurações espaço-temporais a partir do cotidiano de um laboratório de pesquisa; Time and space lived: the productivity of space-time configurations from the routine of a research laboratory

Susin, Loredana
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
35.49%
Nesta Tese de Doutorado, procuro conhecer e entender o funcionamento das configurações espaço-temporais exercidas em um laboratório de pesquisa em bioquímica, visando mostrar seus possíveis efeitos nos processos que constituem as subjetividades. O entendimento de tempo e espaço como categorias socialmente construídas levou-me a buscar compreender os processos sócio-históricos relacionados à sua construção. Inicialmente, apresento o olhar histórico que empreendi com a finalidade de mostrar a emergência das categorias tempo e espaço, entendidas como noções constitutivas de modos de pensar o mundo e a si mesmo. Com esse olhar, busco compreender as implicações dessas categorias na vida das pessoas em diferentes épocas. Para tanto, revisito alguns momentos históricos, desde a Antigüidade até a contemporaneidade, mostrando as compreensões, as necessidades e as estratégias relacionadas ao tempo e ao espaço, marcando continuidades e descontinuidades nesses períodos. A partir dessas reflexões, procuro tornar visíveis o caráter construído dessas noções e o funcionamento das configurações espaço-temporais, assim como chamar a atenção para possíveis efeitos na vida das pessoas. No segundo momento, trago as discussões e as análises do percurso investigativo desta Tese...

Dynamics of the TOM Complex of Mitochondria during Binding and Translocation of Preproteins

Rapaport, Doron; Künkele, Klaus-Peter; Dembowski, Markus; Ahting, Uwe; Nargang, Frank E.; Neupert, Walter; Lill, Roland
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/1998 EN
Relevância na Pesquisa
35.49%
Translocation of preproteins across the mitochondrial outer membrane is mediated by the TOM complex. This complex consists of receptor components for the initial contact with preproteins at the mitochondrial surface and membrane-embedded proteins which promote transport and form the translocation pore. In order to understand the interplay between the translocating preprotein and the constituents of the TOM complex, we analyzed the dynamics of the TOM complex of Neurospora crassa and Saccharomyces cerevisiae mitochondria by following the structural alterations of the essential pore component Tom40 during the translocation of preproteins. Tom40 exists in a homo-oligomeric assembly and dynamically interacts with Tom6. The Tom40 assembly is influenced by a block of negatively charged amino acid residues in the cytosolic domain of Tom22, indicating a cross-talk between preprotein receptors and the translocation pore. Preprotein binding to specific sites on either side of the outer membrane (cis and trans sites) induces distinct structural alterations of Tom40. To a large extent, these changes are mediated by interaction with the mitochondrial targeting sequence. We propose that such targeting sequence-induced adaptations are a critical feature of translocases in order to facilitate the movement of preproteins across cellular membranes.

Patterns of mitochondrial sorting in yeast zygotes.

Azpiroz, R; Butow, R A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1993 EN
Relevância na Pesquisa
35.67%
Inheritance of mitochondrial DNA (mtDNA) in Saccharomyces cerevisiae is usually biparental. Pedigree studies of zygotic first buds indicate limited mixing of wild-type (p+) parental mtDNAs: end buds are frequently homoplasmic for one parental mtDNA, while heteroplasmic and recombinant progeny usually arise from medial buds. In crosses involving certain petites, however, mitochondrial inheritance can be uniparental. In this study we show that mitochondrial sorting can be influenced by the parental mtDNAs and have identified intermediates in the process. In crosses where mtDNA mixing is limited and one parent is prelabeled with the matrix enzyme citrate synthase 1 (CS1), the protein freely equilibrates throughout the zygote before the first bud has matured. Furthermore, if one parent is p0 (lacking mtDNA), mtDNA from the p+ parent can also equilibrate; intracellular movement of mtDNA is unhindered in this case. Surprisingly, in zygotes from a p0 CS1+ x p+ CS1- cross, CS1 is quantitatively translocated to the p+ end of the zygote before mtDNA movement; subsequently, both components equilibrate throughout the cell. This initial vectorial transfer does not require respiratory function in the p+ parent, although it does not occur if that parent is p-. Mouse dihydrofolate reductase (DHFR) present in the mitochondrial matrix can also be vectorially translocated...

Nitrogen-Induced Changes in the Growth and Metabolism of Developing Maize Kernels Grown in Vitro1

Singletary, George W.; Below, Frederick E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1990 EN
Relevância na Pesquisa
35.61%
Cereal kernel growth and grain yield are functions of endosperm starch accumulation. The objective of this study was to examine how various metabolic factors in developing maize (Zea mays L.) endosperm influence starch deposition. Kernels were grown in vitro on medium with: (a) zero N (−N), (b) optimum N (+N), or (c) −N from 3 to 20 days after pollination followed by +N until maturity (±N) to produce different degrees of endosperm growth and to promote an enhancement of starch synthesis midway through development. At intervals, kernels were harvested and levels of enzyme activities and carbohydrate and N constituents examined. Endosperm starch and protein accumulation were decreased in −N compared to +N kernels, but relief of N starvation increased both constituents. With greater movement of N into ±N kernels, endosperm sugar concentrations declined suggesting an inverse relationship between C and N transport. Unusually high concentrations of sugar in N stressed kernels did not appear to limit or enhance starch production. Rather, increased accumulation of starch in ±N endosperm was correlated with significant increases in the enzymatic activities of sucrose synthase and PPi-linked phosphofructokinase, and to a lessor extent hexokinase. In addition...

Polar Transport Related to Mobilization of Plant Constituents

Zaerr, J. B.; Mitchell, J. W.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1967 EN
Relevância na Pesquisa
35.61%
Indole-3-acetic acid (IAA), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), sucrose, and mannitol, were tested for polar transport through 5-mm hypocotyl segments of bean (Phaseolus vulgaris var. Pinto) seedlings. All 4 compounds were transported in a polar direction. Autoradiographs of segments through which 14C-labeled compounds were transported indicated areas of 14C concentration near the morphological base of segments. There was a direct correlation of IAA transport with the ability to initiate roots as well as with the degree of 14C accumulation in the morphological base of segments. Unlabeled IAA in lanolin applied to segments appeared to reduce transport of IAA-14C through those segments when measured by the accumulation of 14C in a receiver-block of agar, caused an increase in 14C accumulation in the region to which the unlabeled IAA was applied, and also caused a decrease in accumulation of 14C at the morphological base of upright segments. Histological studies showed that IAA accelerated cell division and the formation of root primordia particularly at the basal ends, and that these responses sometimes occurred at the expense of cell proliferation at the apical ends of segments. The data presented support the hypothesis that polar movement of IAA...

Intracellular Localization of Phosphatidylinositide 3-kinase and Insulin Receptor Substrate-1 in Adipocytes: Potential Involvement of a Membrane Skeleton

Clark, Sharon F.; Martin, Sally; Carozzi, Amanda J.; Hill, Michelle M.; James, David E.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 09/03/1998 EN
Relevância na Pesquisa
35.5%
Phosphatidylinositide (PI) 3-kinase binds to tyrosyl-phosphorylated insulin receptor substrate-1 (IRS-1) in insulin-treated adipocytes, and this step plays a central role in the regulated movement of the glucose transporter, GLUT4, from intracellular vesicles to the cell surface. PDGF, which also activates PI 3-kinase in adipocytes, has no significant effect on GLUT4 trafficking in these cells. We propose that this specificity may be mediated by differential localization of PI 3-kinase in response to insulin versus PDGF activation. Using subcellular fractionation in 3T3-L1 adipocytes, we show that insulin- and PDGF-stimulated PI 3-kinase activities are located in an intracellular high speed pellet (HSP) and in the plasma membrane (PM), respectively. The HSP is also enriched in IRS-1, insulin-stimulated tyrosyl-phosphorylated IRS-1 and intracellular GLUT4-containing vesicles. Using sucrose density gradient sedimentation, we have been able to segregate the HSP into two separate subfractions: one enriched in IRS-1, tyrosyl-phosphorylated IRS-1, PI 3-kinase as well as cytoskeletal elements, and another enriched in membranes, including intracellular GLUT4 vesicles. Treatment of the HSP with nonionic detergent, liberates all membrane constituents...

Redistribution of the tight junction protein ZO-1 during physiological shedding of mouse intestinal epithelial cells

Guan, Yanfang; Watson, Alastair J. M.; Marchiando, Amanda M.; Bradford, Emily; Shen, Le; Turner, Jerrold R.; Montrose, Marshall H.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.58%
We questioned how tight junctions contribute to intestinal barrier function during the cell shedding that is part of physiological cell renewal. Intravital confocal microscopy studied the jejunal villus epithelium of mice expressing a fluorescent zonula occludens 1 (ZO-1) fusion protein. Vital staining also visualized the cell nucleus (Hoechst staining) or local permeability to luminal constituents (Lucifer Yellow; LY). In a cell fated to be shed, ZO-1 redistributes from the tight junction toward the apical and then basolateral cell region. ZO-1 rearrangement occurs 15 ± 6 min (n = 28) before movement of the cell nucleus from the epithelial layer. During cell extrusion, permeation of luminal LY extends along the lateral intercellular spaces of the shedding cell only as far as the location of ZO-1. Within 3 min after detachment from the epithelial layer, nuclear chromatin condenses. After cell loss, a residual patch of ZO-1 remains in the space previously occupied by the departed cell, and the size of the patch shrinks to 14 ± 2% (n = 15) of the original cell space over 20 min. The duration of cell shedding measured by nucleus movement (14 ± 1 min) is much less than the total duration of ZO-1 redistribution at the same sites (45 ± 2 min). In about 15% of cell shedding cases...

Agrammatic Comprehension of Simple Active Sentences With Moved Constituents: Hebrew OSV and OVS Structures

Friedmann, Naama; Shapiro, Lewis P.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/2003 EN
Relevância na Pesquisa
35.66%
This study examines agrammatic comprehension of object-subject-verb (OSV) and object-verb-subject (OVS) structures in Hebrew. These structures are syntactically identical to the basic order subject-verb-object (SVO) sentence except for the movement of the object to the beginning of the sentence, and thus enable empirical examination of syntactic movement in agrammatic comprehension. Seven individuals with agrammatism, 7 individuals with conduction aphasia, and 7 individuals without language impairment, all native speakers of Hebrew, performed a sentence–picture matching task. The task compared OSV and OVS sentences to SVO sentences and to subject and object relatives. Individuals with agrammatism performed more poorly than those in either of the other groups. Their comprehension of SVO sentences was significantly above chance, but comprehension of OSV and OVS sentences was at chance and was poorer than comprehension of SVO sentences. These results show that agrammatic comprehension of structures that involve movement of a noun phrase is impaired even when the structure is a simple active sentence, in line with the Trace Deletion Hypothesis (TDH; Y. Grodzinsky, 1990, 1995a, 2000). A modification is suggested to accommodate the TDH with the VP Internal Subject Hypothesis...

Crystallographic Observation of pH-Induced Conformational Changes in the Amyelois transitella Pheromone-Binding Protein AtraPBP1

di Luccio, Eric; Ishida, Yuko; Leal, Walter S.; Wilson, David K.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 13/02/2013 EN
Relevância na Pesquisa
45.58%
The navel orangeworm, Amyelois transitella is a major agricultural pest causing large losses in a variety of tree crops. Control of this insect pest may be achieved by interfering with olfactory pathways to block detection of female-produced sex pheromones and consequently, disrupt mating. The first component of this pathway is the pheromone-binding protein AtraPBP1, which recognizes the pheromone and presents it to the odorant receptor housed in a sensory neuron of the male antennae. Release of the ligand depends on a pH-induced conformational change associated with the acidity of the membrane surface. To characterize this conformational change and to understand how pheromones bind, we have determined the high resolution crystal structures of AtraPBP1 in complex with two main constituents of the sex pheromone, i.e., (11Z,13Z)-hexadecadienal and (11Z,13Z)-hexadecadienol. Comparison with the structure of the unliganded form demonstrates a large ∼90° movement of the C-terminal helix which is observed in other pheromone- or odorant-binding proteins accompanied by an unpredicted 37° displacement of the N-terminal helix. Molecular dynamic trajectories suggest that the conformational change of the α1 helix facilitates the movement of the C-terminal helix.

The Stable Association of Virion with the Triple-gene-block Protein 3-based Complex of Bamboo mosaic virus

Chou, Yuan-Lin; Hung, Yi-Jing; Tseng, Yang-Hao; Hsu, Hsiu-Ting; Yang, Jun-Yi; Wung, Chiung-Hua; Lin, Na-Sheng; Meng, Menghsiao; Hsu, Yau-Heiu; Chang, Ban-Yang
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
45.63%
The triple-gene-block protein 3 (TGBp3) of Bamboo mosaic virus (BaMV) is an integral endoplasmic reticulum (ER) membrane protein which is assumed to form a membrane complex to deliver the virus intracellularly. However, the virus entity that is delivered to plasmodesmata (PD) and its association with TGBp3-based complexes are not known. Results from chemical extraction and partial proteolysis of TGBp3 in membrane vesicles revealed that TGBp3 has a right-side-out membrane topology; i.e., TGBp3 has its C-terminal tail exposed to the outer surface of ER. Analyses of the TGBp3-specific immunoprecipitate of Sarkosyl-extracted TGBp3-based complex revealed that TGBp1, TGBp2, TGBp3, capsid protein (CP), replicase and viral RNA are potential constituents of virus movement complex. Substantial co-fractionation of TGBp2, TGBp3 and CP, but not TGBp1, in the early eluted gel filtration fractions in which virions were detected after TGBp3-specific immunoprecipitation suggested that the TGBp2- and TGBp3-based complex is able to stably associate with the virion. This notion was confirmed by immunogold-labeling transmission electron microscopy (TEM) of the purified virions. In addition, mutational and confocal microscopy analyses revealed that TGBp3 plays a key role in virus cell-to-cell movement by enhancing the TGBp2- and TGBp3-dependent PD localization of TGBp1. Taken together...

The influence of dynein processivity control, MAPs, and microtubule ends on directional movement of a localising mRNA

Soundararajan, Harish Chandra; Bullock, Simon L
Fonte: eLife Sciences Publications, Ltd Publicador: eLife Sciences Publications, Ltd
Tipo: Artigo de Revista Científica
Publicado em 15/04/2014 EN
Relevância na Pesquisa
35.5%
Many cellular constituents travel along microtubules in association with multiple copies of motor proteins. How the activity of these motors is regulated during cargo sorting is poorly understood. In this study, we address this issue using a novel in vitro assay for the motility of localising Drosophila mRNAs bound to native dynein-dynactin complexes. High precision tracking reveals that individual RNPs within a population undergo either diffusive, or highly processive, minus end-directed movements along microtubules. RNA localisation signals stimulate the processive movements, with regulation of dynein-dynactin’s activity rather than its total copy number per RNP, responsible for this effect. Our data support a novel mechanism for multi-motor translocation based on the regulation of dynein processivity by discrete cargo-associated features. Studying the in vitro responses of RNPs to microtubule-associated proteins (MAPs) and microtubule ends provides insights into how an RNA population could navigate the cytoskeletal network and become anchored at its destination in cells.

Tropical Cyclone Impacts on Coastal Regions: the Case of the Yucatán and the Baja California Peninsulas, Mexico

Farfan, Luis M.; D'Sa, Eurico J.; Liu, Kam-biu; Rivera-Monroy, Victor H.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
35.5%
Tropical cyclones (TCs) are large-scale natural disturbances that generate strong winds and heavy rainfall, impacting coastal and inland environments. TCs also influence biogeochemical and hydrological cycles controlling aquatic primary productivity in tropical and subtropical coastal ecosystems. We assessed TC landfall activity and identified sites along the Mexican east and west coasts with high frequency in the period 1970–2010 and evaluated TCs with significant precipitation. Changes in chlorophyll-a (Chl-a) concentrations before and after storm impacts were estimated using remotely sensed ocean color. There were 1,065 named TCs with a wide diversity in tracks. Three states with the highest number of landfalls were identified: Baja California Sur and Sinaloa on the west coast and Quintana Roo on the east coast. While a relative increase in Chl-a values following TC landfalls in the Baja California and Yucatán Peninsula regions appeared to be strongly linked to TC strength, the intensity of precipitation, the spatial scales of the two peninsulas, and the relative movement of TCs appeared to have contributed to Chl-a variability. Satellite estimates of Chl-a in the nearshore coastal waters following TC passage were likely enhanced by coastal morphology and water discharge along with constituents such as suspended particulate...

Knowledge, Technology, and Cluster-Based Growth in Africa

Zeng, Douglas Zhihua
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
Tipo: Publications & Research :: Publication; Publications & Research :: Publication
ENGLISH; EN_US
Relevância na Pesquisa
35.5%
Although Africa is falling behind in today's global economic race, it holds pockets of vital economic activity -- many in the form of enterprise clusters scattered across the continent's countries and industries. By clustering, enterprises are able to overcome constraints in capital, skills, technology, and markets. Enterprise clusters help their constituents grow and compete by encouraging more effective knowledge and technology diffusion and product specialization, leveraging local comparative advantage, fostering production value chains, and achieving collective efficiency. In so doing, they contribute significantly to Africa's economic growth. They provide jobs for the continent's growing population, thus enabling families not only to survive, but also to educate their children and perhaps move out of poverty. But in today's increasingly knowledge-intensive and globalized economy, these clusters also face serious challenges in the areas of technology, natural resources, infrastructure, skill acquisition...

Biochemical and histological investigations of viral localisation in the hypersensitive reaction of Phaselous vulgaris L. var Pinto to tobacco mosaic virus infection

Stobbs, Lorne W.
Fonte: Brock University Publicador: Brock University
Tipo: Electronic Thesis or Dissertation
ENG
Relevância na Pesquisa
45.58%
STOBBS, Lorne,W ABSTRACT Biochemical and Histological Investigations of viral localisation in the hypersensitive reaction of Phaseolus vulgaris L. var Pinto to tobacco mosaic virus infection. The infection of Phaseolus vulgaris L. var Pinto with tobacco mosaic virus (TMV) results in the production of distinct necrotic lesions confining the virus to restricted areas of the leaf surface. Biochemical and histological changes in the leaf tissue as a result of infection have been described. Trace accumulations of fluorescent metabolites, detected prior to lesion expression represent metabolites produced, by the cell in response to virus infection. These substances, are considered to undergo oxidation and in diffusing into adjacent cells, react with cellular constituents causing the death of these cells. Such cellular necrosis in advance of infection effectively limits virus spread. Chromatographic studies on extracts from TMV infected Pinto bean leaf tissue suggests that a number of extra-fluorescent metabolites produced on lesion'expression represent end products of phenolic oxidation r,eactionsoccurring earlier in these cells. Inhibition of phenolic oxidation by ascorbate infiltration or elevated temperature treatment resulted in the absence of extra-fluorescent metabolites and the continued movement of virus in the absence of necrosis. Further studies with i ascorbate infiltration indicated that irreversible necrotic events were determined as early as 12 tci 18 hrs after viral inoculation. Histochemical tests indicated that callose formation was initiated at this time...

Ordem de palavras, movimento do verbo e efeito V2 na história do espanhol; Word order, verb movement and verb second in the history of Spanish

Carlos Felipe da Conceição Pinto
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/11/2011 PT
Relevância na Pesquisa
35.8%
Esta Tese discute a mudança na ordem de constituintes e no posicionamento do verbo finito na história do espanhol europeu. Fontana (1993) propõe que o espanhol antigo era uma língua V2 simétrica, como o iídiche e o islandês atuais, na qual o verbo se movia para Io e SpeclP era uma posição A-Barra. Zubizarreta (1998) propõe que, no espanhol atual, o verbo também se mova para |o e que SpeclP ainda seja uma posição A-Barra. Neste sentido, se entende que a proposta de Zubizarreta (1998) é a de que as duas fases da língua são estruturalmente idênticas; contudo, o que os dados de Fontana (1993) mostram é que há diferenças estruturais importantes entre elas. O Capítulo 01 se concentra na discussão formal do efeito V2 nas línguas germânicas, que são consideradas as línguas V2 prototípicas, enfatizando: a) qual é o gatilho para o movimento do verbo; b) o que desencadeia a variação na manifestação do efeito V2 nas orações subordinadas fazendo com que algumas línguas apresentem efeito V2 irrestritamente e outras só apresentem efeito V2 nas orações matrizes. É proposta uma análise unificada em que, em ambos os casos, o verbo sempre se move para Co em orações matrizes e que a variação no traço [±asserção] é o responsável pela variação do efeito V2 nas orações subordinadas. O Capítulo 02 apresenta os dados do espanhol antigo e do espanhol atual. O trabalho se concentra em orações finitas e declarativas. Mostra-se que há aspectos que não distinguem superficialmente as duas fases...

Trafficlike collective movement of ants on trails: absence of jammed phase

John, Alexander; Schadschneider, Andreas; Chowdhury, Debashish; Nishinari, Katsuhiro
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 16/03/2009
Relevância na Pesquisa
45.58%
We report experimental results on unidirectional traffic-like collective movement of ants on trails. Our work is primarily motivated by fundamental questions on the collective spatio-temporal organization in systems of interacting motile constituents driven far from equilibrium. Making use of the analogies with vehicular traffic, we analyze our experimental data for the spatio-temporal organisation of the ants on the trail. From this analysis, we extract the flow-density relation as well as the distributions of velocities of the ants and distance-headways. Some of our observations are consistent with our earlier models of ant-traffic, which are appropriate extensions of the asymmetric simple exclusion process (ASEP). In sharp contrast to highway traffic and most other transport processes, the average velocity of the ants is almost independent of their density on the trail. Consequently, no jammed phase is observed.; Comment: 4 pages, 5 figures

La moda como objeto de información: el caso del movimiento feminista punk Riot Grrrl; Fashion as an information object: the case of the punk feminist movement Riot Grrrl; A moda como objeto de informação: o caso do Movimento Feminista Punk Riot Grrrl

Castro, Kedma Lima de; Universidade da Amazônia - UNAMA; Castro, Jetur Lima de; Universidade Federal do Pará - UFPA; Oliveira, Alessandra Nunes de; Universidade Federal do Pará - UFPA
Fonte: Mestrado Interdisciplinar em Ciência, Gestão e Tecnologia da Informação - UFPR Publicador: Mestrado Interdisciplinar em Ciência, Gestão e Tecnologia da Informação - UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artículo evaluado por pares; Exploratorio; documental; ; Exploratory; documental; Avaliado pelos pares; Exploratório; documental Formato: text/html; application/zip; application/pdf
Publicado em 14/09/2015 POR
Relevância na Pesquisa
35.68%
Introduction: In considering the issue of fashion as an object of information, the study aims to present the behavior and attire characteristics of the punk feminist movement Riot Grrrrl as constituents of a singular language and discourse space and, therefore, subject to further investigations by the area of Library and Information Science. Method: This is an exploratory research of bibliographic and documentary base. Results: it presents the historical scene of punk feminist movement Riot Grrrrl within the punk background, analyzing the theme of feminism, the discussion of gender and its relationship with the overall fashion context. It was revealed that the Riot Grrrrls´ behavior and attire act as way of gender and political dissent. Conclusion: the visual reinterpretation of a punk feminist movement supported in their radical ideologies and their impact on the fashion world shows the representative nature of attire and behavior as emancipatory forms in the social, configured as discourse spaces and, therefore, as an information attribute.; Introdução: Ao se considerar que a moda pode ser entendida como objeto de informação, o objetivo do trabalho é apresentar as características de indumentária e de comportamento do movimento feminista punk Riot Grrrrl como constituintes espaço de discurso e de linguagem e...