751 resultados para 1104
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One of the most fascinating aspects of plant morphology is the regular geometric arrangement of leaves and flowers, called phyllotaxy. The shoot apical meristem (SAM) determines these patterns, which vary depending on species and developmental stage. Auxin acts as an instructive signal in leaf initiation, and its transport has been implicated in phyllotaxy regulation in Arabidopsis (Arabidopsis thaliana). Altered phyllotactic patterns are observed in a maize (Zea mays) mutant, aberrant phyllotaxy1 (abph1, also known as abphyl1), and ABPH1 encodes a cytokinin-inducible type A response regulator, suggesting that cytokinin signals are also involved in the mechanism by which phyllotactic patterns are established. Therefore, we investigated the interaction between auxin and cytokinin signaling in phyllotaxy. Treatment of maize shoots with a polar auxin transport inhibitor, 1-naphthylphthalamic acid, strongly reduced ABPH1 expression, suggesting that auxin or its polar transport is required for ABPH1 expression. Immunolocalization of the PINFORMED1 (PIN1) polar auxin transporter revealed that PIN1 expression marks leaf primordia in maize, similarly to Arabidopsis. Interestingly, maize PIN1 expression at the incipient leaf primordium was greatly reduced in abph1 mutants. Consistently, auxin levels were reduced in abph1, and the maize PIN1 homolog was induced not only by auxin but also by cytokinin treatments. Our results indicate distinct roles for ABPH1 as a negative regulator of SAM size and a positive regulator of PIN1 expression. These studies highlight a complex interaction between auxin and cytokinin signaling in the specification of phyllotactic patterns and suggest an alternative model for the generation of altered phyllotactic patterns in abph1 mutants. We propose that reduced auxin levels and PIN1 expression in abph1 mutant SAMs delay leaf initiation, contributing to the enlarged SAM and altered phyllotaxy of these mutants.
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Transcription factors (TFs) are major players in gene regulatory networks and interactions between TFs and their target genes furnish spatiotemporal patterns of gene expression. Establishing the architecture of regulatory networks requires gathering information on TFs, their targets in the genome, and the corresponding binding sites. We have developed GRASSIUS (Grass Regulatory Information Services) as a knowledge-based Web resource that integrates information on TFs and gene promoters across the grasses. In its initial implementation, GRASSIUS consists of two separate, yet linked, databases. GrassTFDB holds information on TFs from maize (Zea mays), sorghum (Sorghum bicolor), sugarcane (Saccharum spp.), and rice (Oryza sativa). TFs are classified into families and phylogenetic relationships begin to uncover orthologous relationships among the participating species. This database also provides a centralized clearinghouse for TF synonyms in the grasses. GrassTFDB is linked to the grass TFome collection, which provides clones in recombination-based vectors corresponding to full-length open reading frames for a growing number of grass TFs. GrassPROMDB contains promoter and cis-regulatory element information for those grass species and genes for which enough data are available. The integration of GrassTFDB and GrassPROMDB will be accomplished through GrassRegNet as a first step in representing the architecture of grass regulatory networks. GRASSIUS can be accessed from www.grassius.org.
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Glucose modulates plant metabolism, growth, and development. In Arabidopsis (Arabidopsis thaliana), Hexokinase1 (HXK1) is a glucose sensor that may trigger abscisic acid (ABA) synthesis and sensitivity to mediate glucose-induced inhibition of seedling development. Here, we show that the intensity of short-term responses to glucose can vary with ABA activity. We report that the transient (2 h/4 h) repression by 2% glucose of AtbZIP63, a gene encoding a basic-leucine zipper (bZIP) transcription factor partially involved in the Snf1-related kinase KIN10-induced responses to energy limitation, is independent of HXK1 and is not mediated by changes in ABA levels. However, high-concentration (6%) glucose-mediated repression appears to be modulated by ABA, since full repression of AtbZIP63 requires a functional ABA biosynthetic pathway. Furthermore, the combination of glucose and ABA was able to trigger a synergistic repression of AtbZIP63 and its homologue AtbZIP3, revealing a shared regulatory feature consisting of the modulation of glucose sensitivity by ABA. The synergistic regulation of AtbZIP63 was not reproduced by an AtbZIP63 promoter-5`-untranslated region:beta-glucuronidase fusion, thus suggesting possible posttranscriptional control. A transcriptional inhibition assay with cordycepin provided further evidence for the regulation of mRNA decay in response to glucose plus ABA. Overall, these results indicate that AtbZIP63 is an important node of the glucose-ABA interaction network. The mechanisms by which AtbZIP63 may participate in the fine-tuning of ABA-mediated abiotic stress responses according to sugar availability (i.e., energy status) are discussed.
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Studiens syfte var att undersöka de samspelssituationer som råder mellan allmänheten och handläggarna på försäkringskassan, men även att undersöka hur handläggarna upplever sin egen arbetssituation. Mellan handläggarna och allmänheten indikerar studien att allmänheten för det mesta är nöjd med handläggarna på försäkringskassan. Men studien visar även att allmänheten finner det oacceptabelt med en väntetid på två månader för utbetalning av ersättning. Något som båda grupperna har gemensamt är att bemötande är viktigt. Iden till studien växte fram ur de debatterna som förekom i media och om hur försäkringskassan har förändrat sitt arbetssätt genom att granska först och betala ut sedan mot tidigare att betala först och granska sedan. Datainsamlingen genomfördes med två enkäter. Totalt deltog 135 från allmänheten och 43 handläggare från lokalkontoret i Borlänge respektive länskontoret i Falun.
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Reader-Response Criticism and the Internet: A Methodological Discussion This article explores connections between Internet-based research and reader-response criticism, aiming to critically discuss the methodologies used in this particular field of research. First, the history of reader-response studies is briefly presented, with reference to theorists such as Richards, Rosenblatt, Robbe-Grillet, Iser and Jauss. It is noted that, for the past 15 years, people have utilised the Internet as a basis for the discussion of literary and reading-related topics. Researchers in this field may access reviews and commentaries on open web-based venues such as personal homepages, blogs and online forums (i.e. message boards and discussion sites). The material available on these sites is interesting because of its "spontaneous" nature; that is, such material has been formulated and uploaded without the interference of the researcher. The article presents one concrete example of an Internet-based reader-response study, discussing a number of pros and cons of the chosen methodology– including some important ethical considerations that arise when the researcher’s corpus is composed of material taken from the Internet. One of the conclusions of the paper is that many aspects of the general public’s web-based responses to literature are yet to be explored by the research community.
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It is an everyday experience to realize that things do not turn out the as expected. But what if you realize that everything you have so far experienced as reality is illusion? This article is about former members of the Jehovah’s Witnesses who have had doubts about what they previously believed to be the Truth. The article also treats the exit process, from being a Jehovah’s Witness to becoming an ex-Jehovah’s Witness. The data consists of twenty qualitative interviews with ten Jehovah’s Witnesses and twenty qualitative interviews with ten former Jehovah’s Witnesses. The data also include a diary written during four years preceding an exit from the organization. The analysis was made through thematic concentration. Ontologically the analysis and the article are based on a constructionist view though it is mainly empirical with no further theoretical assessment. However, to be able to understand the results a contextual frame is sketched with two factors affecting members who make an exit. First there are tying factors that bind the person closer to the organization; these are closeness and friendship and confirmation. A secluding factor is something that secludes the member from the outside society; these factors are the work situation and »closed doors«. With high values on these factors the exit process will be more arduous. The results are presented through a process model in which different phases or steps in the exit process are described. The following steps in the process are: (1) different levels of doubts; (2) trying out doubts; (3) turning points; (4) different decisions; (5) different steps in execution; (6) floating; (7) relative neutrality. The process is defined as an altogether ambivalent and emotionally tough experience, but other parts of life may be affected as well, such as employment, social life, family life and career.
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In this paper we present an approach to information flow analysis for a family of languages. We start with a simple imperative language. We present an information flow analysis using a flow logic. The paper contains detailed correctness proofs for this analysis. We next extend the analysis to a restricted form of Idealised Algol, a call-by-value higher-order extension of the simple imperative language (the key restriction being the lack of recursion). The paper concludes with a discussion of further extensions, including a probabilistic extension of Idealised Algol.
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David J. Stevens and Ernest Fitzgerald were 1948 graduates of the Plumbing Department at the New York Trade School and are pictured with a truck from their successful D.H. Stevens Company in Washington, DC. Original caption reads, "David J. Stevens - Plumbing 1948, is shown here with Ernest Fitzgerald - Plumbing 1948, with two of their thirteen pieces of equipment necessary to satisfy 650 calls per month. David Stevens is the third generation to have graduated from Plumbing." Black and white photograph with caption adhered to reverse.
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In her January 20, 2015 interview with Michelle Dubert-Bellrichard, Jeuel Esmacher Bannister details her time at Winthrop from 1940-1944. Shared are the memories of professors in the music department, her opinions on the expectations of students, and going to school during WWII. Esmacher Bannister recalls stories of the Army Air Corps Cadets on campus, and the courses offered by the U.S. government that led Esmacher Bannister to a career as a Japanese and Russian cryptographer. This interview was conducted for inclusion into the Louise Pettus Archives and Special Collections Oral History Program.
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Summer Graphic Design workshops Co-sponsored by the Continuing Education Division and the Graphic Design Dept. Schedule A & B, tuition $410.00, Applied Semiotics for Design Seminar $625.00
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Print No:66; Initials Lower Left: WH; Initials Lower Left: DN; Initials Lower Left: GY
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Introdução: Bronquiolite viral aguda (BVA) é a doença respiratória mais grave de lactentes previamente hígidos. Ocorre em epidemias anuais durante os meses de inverno, sendo uma causa freqüente de hospitalizações nesta faixa etária. O agente etiológico mais freqüente é o vírus respiratório sincicial (VRS). É uma doença benigna na maioria dos casos, mas pode apresentar-se de forma grave em alguns pacientes e freqüentemente produz seqüelas após o episódio agudo. Nos últimos anos vários estudos têm procurado elucidar a patogênese da BVA e suas seqüelas, e mecanismos imunológicos e de resposta inflamatória têm sido pesquisados. O papel dos eosinófilos e suas proteínas citotóxicas, como a Proteína Catiônica Eosinofílica (PCE), têm sido investigado na BVA, com resultados inconclusivos. O objetivo do presente estudo é determinar a contagem de eosinófilos no sangue periférico e a concentração sérica de PCE em pacientes internados com BVA e comparar com diferentes graus de gravidade. Pacientes e Métodos: Foi realizado um estudo com lactentes menores de 1 ano que internaram no Hospital da Criança Santo Antônio (HCSA) no período de junho a agosto de 1999 com quadro clínico de BVA com os seguintes critérios de inclusão: freqüência respiratória maior ou igual a 60 movimentos por minuto, ou saturação da hemoglobina (satHb) menor do que 95%. Foram excluídos pacientes com história prévia de doença respiratória inferior e pacientes com uso prévio de cortiscoteróides. Os pacientes elegíveis para o estudo foram avaliados nas primeiras 12 horas de internação. Foi colhida amostra de secreção nasofaríngea para pesquisa de vírus respiratpórios. Foi colhida amostra de sangue para hemograma e reservada uma amostra para determinação da PCE. Foram realizadas comparações do número de eosinófilos e concentração de PCE entre grupos de pacientes conforme a gravidade, sexo e faixa etária. Foram utilizados como critérios de gravidade a satHb em ar ambiente e a prevalência de ventilação mecânica. A análise estatística foi realizada através dos testes de Mann-Whitney e Kruskal-Wallis, e teste de correlação de Spearman para as associações. Foi considerado (alfa) crítico de 5% para significância estatística. Resultados: Foram estudados 58 pacientes, 32 (55%) eram do sexo masculino. A idade variou de 0 a 10 meses, com média de 2 meses. Dezenove pacientes foram classificados como graves de acordo com a satHb, inferior a 90%. Sete pacientes necessitaram ventilação mecânica, resultando numa prevalência de 12%. A prevalência do VRS foi de 62% entre os pacientes nos quais foi realizada pesquisa virológica (48 pacientes). A contagem de eosinófilos sangüíneos variou de 0 a 1104, com mediana de 100. O número de eosinófilos foi maior nos lactentes menores de 3 meses em relação aos maiores de 3 meses (p=0.052). Verificou-se que o número de eosinófilos foi menor nos pacientes com saturação mais baixa (p<0.05). Os pacientes que necessitaram ventilação mecânica também apresentaram menor número de eosinófilos, porém sem significância estatística. A concentração sérica de PCE na amostra estudada variou de 2 a 114 g/litro, com mediana em 6 g/l. Não houve correlação com satHb nem com ventilação mecânica e PCE. Conclusões: Houve associação entre baixo número de eosinófilos e gravidade da BVA medida pela satHb. Não houve associação entre PCE e gravidade. Estudos adicionais são necessários para elucidar melhor o papel de eosinófilos e seus derivados na determinação da gravidade da bronquiolite.