970 resultados para Frank Castorf


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Homoploid hybrid plant species are rare, and the mechanisms of their speciation are largely unknown, especially for homoploid hybrid tree species. Two contrasting hypotheses have been proposed to explain the origin of Hippophae goniocarpa: (1) it is a diploid hybrid originating from H. rhamnoides ssp. sinensis x H. neurocarpa ssp. neurocarpa, and (2) it originated via marginal differentiation from H. rhamnoides ssp. sinensis. Regardless of which of these hypotheses is true (if either), previous studies have suggested that H. rhamnoides ssp. sinensis is the only maternal donor for this hybrid species. In this study, we aim to elucidate the maternal composition of H. goniocarpa and to test the two hypotheses. For this purpose, we sequenced the maternal chloroplast DNA trnL-F region of 75 individuals representing H. goniocarpa, H. rhamnoides ssp. sinensis, and H. neurocarpa ssp. neurocarpa in two co-occurring sites of the taxa. Seven haplotypes were identified from three taxonomic units, and their phylogenetic relationships were further constructed by means of maximum parsimony, maximum likelihood, and network analyses. These seven haplotypes clustered into two distinct, highly divergent lineages. Two haplotypes from one lineage were found in H. rhamnoides ssp. sinensis, and five (representing the other lineage) in H. neurocarpa ssp. neurocarpa. Hippophae goniocarpa shared four common haplotypes from both lineages, but the haplotypes detected from the two populations differed to some extent, and in each case were identical to local haplotypes of the putative parental species. Thus, both H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa appear to have together contributed to the maternal establishment of H. goniocarpa. These results clearly demonstrate that the marginal origin hypothesis should be rejected, and support the hybrid origin hypothesis. Hippophae goniocarpa exhibits a sympatric distribution with its two parent species, without occupying new niches or displaying complete ecological isolation. However, this species has effectively developed reproductive isolation from its sympatric parent species. Our preliminary results suggest that H. goniocarpa may provide a useful model system for studying diploid hybrid speciation in trees. (c) 2008 The Linnean Society of London.

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Procedimento para identificação dos fungos das sementes de trigo; Descrição diagnostica dos principais fungos das sementes de trigo; Sclerotium Tode; Rhizoctonia DC; Chaetomium Kunze; Pleospora Rabenh; Sporobolomyces Kluy. & Niel; Rhodotorula Harrison; Phoma Sacc.; Septoria tritici Rob; Stagonospora nodorum (Berk.) Cas. & Germ.; Stagonospora avenae (Frank) Bisset f. sp. triticae; Colletotrichum graminicola (Ces.) Wilson; Fusarium tricinctum (Corda) Sacc; Fusarium moniliforme Sheldon; Fusarium avenaceum (Fr.) Sacc; Fusarium acuminatum Ell. & Kellerm; Fusarium equiseti (Corda) Sacc.; Fusarium graminearum Schw.; Mucor Micheli; Rhizopus Ehrenb; Aspergillus Link.; Penicillium Link.; Alternaria Nees; Epicoccum Link; Cladosporium Link; Nigrospora Zimm; Curvularia Boedijn; Drechslera tritici-repentis (Died.) Drech; Bipolaris sorokiniana (Sacc. in Sorok.) Shoem; Chave sistemática dos principais fungos de sementes de trigo; Ilustrações dos principais fungos encontrados em sementes de trigo.

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O sistema de cultivo do feijoeiro comum, no Estado do Acre, é típico de pequenos agricultores, o uso de insumos e máquinas é mínimo e toda mão-de-obra do processo produtivo é familiar. As áreas de cultivo dificilmente ultrapassam 5 ha, a produtividade é baixa e o excedente da produção é comercializado exclusivamente no mercado estadual. Esta cultura é a principal fonte de proteínas disponível por todo o ano nas pequenas propriedades, demonstrando importância nutricional e social para as famílias de baixa renda. As variedades de maior preferência dos agricultores e consumidores locais são o feijão Carioca Comum e o Rosinha de porte determinado. Entretanto, os materiais utilizados têm sido severamente prejudicados pela incidência da "mela" (Thanatephorus cucumeris (Frank) Donk). Estudos têm sido realizados no sentido de controlar ou minimizar esta doença, no entanto, até o momento não foi obtido um controle efetivo. A adoção de práticas culturais, como a cobertura do solo com restos culturais, diminui bastante os prejuízos, entretanto, esta prática por si só, não resolve o problema. A Embrapa Acre, desde a sua implantação, vem desenvolvendo trabalhos de introdução e avaliação de genótipos de feijão, visando a seleção e recomendação de materiais com características que superem os problemas da baixa produtividade e resistência à meia na região, bem como atender às exigências do mercado local, principalmente no que se refere ao tipo de grão. A introdução de genótipos, embora seja de fundamental importância para programas de melhoramento, nem sempre proporciona resultados imediatos e de interesse para a região, tendo em vista, principalmente, problemas de adaptação às novas condições edafoclimáticas.

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Procedimento para identificação dos fungos das sementes de trigo; Descrição diagnostica dos principais fungos das sementes de trigo; Sclerotium Tode; Rhizoctonia DC; Chaetomium Kunze; Pleospora Rabenh; Sporobolomyces Kluy. & Niel; Rhodotorula Harrison; Phoma Sacc.; Septoria tritici Rob; Stagonospora nodorum (Berk.) Cas. & Germ.; Stagonospora avenae (Frank) Bisset f. sp. triticae; Colletotrichum graminicola (Ces.) Wilson; Fusarium tricinctum (Corda) Sacc; Fusarium moniliforme Sheldon; Fusarium avenaceum (Fr.) Sacc; Fusarium acuminatum Ell. & Kellerm; Fusarium equiseti (Corda) Sacc.; Fusarium graminearum Schw.; Mucor Micheli; Rhizopus Ehrenb; Aspergillus Link.; Penicillium Link.; Alternaria Nees; Epicoccum Link; Cladosporium Link; Nigrospora Zimm; Curvularia Boedijn; Drechslera tritici-repentis (Died.) Drech; Bipolaris sorokiniana (Sacc. in Sorok.) Shoem; Chave sistemática dos principais fungos de sementes de trigo; Ilustrações dos principais fungos encontrados em sementes de trigo.

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Huelse, M., Wischmann, S., Manoonpong, P., Twickel, A.v., Pasemann, F.: Dynamical Systems in the Sensorimotor Loop: On the Interrelation Between Internal and External Mechanisms of Evolved Robot Behavior. In: M. Lungarella, F. Iida, J. Bongard, R. Pfeifer (Eds.) 50 Years of Artificial Intelligence, LNCS 4850, Springer, 186 - 195, 2007.

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„We are paying a high price for the increasingly unequivocal equation drawn between knowledge and science and ordinary market product. The ideal of perfectly unrestrained cognition, the true mother of science, is threatened by the mass drive towards practical use and application of knowledge, a looming departure into nothingness. Politicians and managers of scientific life are guilty of considerable contribution in corrupting respectable university structures, and thus undermining culture of science and scholarly ethics. (…). Acquisition of funds, sponsorship, media presence, popularisation or even striving for commercial gain are recognised by politicians and scientific consultants, but most of all they are accepted by the university management as objectives worthy of effort, not to say the foremost goals of science. University rectors are nowadays interested primarily in the amounts of acquired moneys. The outcomes of research thus financed is subject to virtually no control, nor does it arouse any interest, unless it turns out to be fit to be announced in the media as a sensation, thereby serving the ‘prestige’ of the university”.

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The impacts of antiretroviral therapy on quality of life, mental health, labor productivity, and economic wellbeing for people living with HIV/AIDS in developing countries are only beginning to be measured. We conducted a systematic literature review to analyze the effect of antiretroviral therapy (ART) on these non-clinical indicators in developing countries and assess the state of research on these topics. Both qualitative and quantitative studies were included, as were peer-reviewed articles, gray literature, and conference abstracts and presentations. Findings are reported from 12 full-length articles, 7 abstracts, and 1 presentation (representing 16 studies). Compared to HIV-positive patients not yet on treatment, patients on ART reported significant improvements in physical, emotional and mental health and daily function. Work performance improved and absenteeism decreased, with the most dramatic changes occurring in the first three months of treatment and then leveling off. Little research has been done on the impact of ART on household wellbeing, with modest changes in child and family wellbeing within households where adults are receiving ART reported so far. Studies from developing countries have not yet assessed non-clinical outcomes of therapy beyond the first year; therefore, longitudinal outcomes are still unknown. As ART roll out extends throughout high HIV prevalence, low-resource countries and is sustained over years and decades, both positive and adverse non-clinical outcomes need to be empirically measured and qualitatively explored in order to support patient adherence and maximize treatment benefits.

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To investigate the process underlying audiovisual speech perception, the McGurk illusion was examined across a range of phonetic contexts. Two major changes were found. First, the frequency of illusory /g/ fusion percepts increased relative to the frequency of illusory /d/ fusion percepts as vowel context was shifted from /i/ to /a/ to /u/. This trend could not be explained by biases present in perception of the unimodal visual stimuli. However, the change found in the McGurk fusion effect across vowel environments did correspond systematically with changes in second format frequency patterns across contexts. Second, the order of consonants in illusory combination percepts was found to depend on syllable type. This may be due to differences occuring across syllable contexts in the timecourses of inputs from the two modalities as delaying the auditory track of a vowel-consonant stimulus resulted in a change in the order of consonants perceived. Taken together, these results suggest that the speech perception system either fuses audiovisual inputs into a visually compatible percept with a similar second formant pattern to that of the acoustic stimulus or interleaves the information from different modalities, at a phonemic or subphonemic level, based on their relative arrival times.