Sekundäre Sukzession im afromontanen Nebelwald : Dynamik, Mechanismen und Schutz der Biodiversität in zwei Habitaten des Berggorillas (Mgahinga Gorilla- und Bwindi Impenetrable- Nationalpark) und im Echuya Forest, Uganda

Die vorliegende Untersuchung fand im Südwesten Ugandas statt, und zwar in zwei 1992 als Nationalpark ausgewiesenen Lebensräumen des Berggorillas und in einem benachbarten Wald. Das Spektrum der natürlichen Vegetation der drei Untersuchungsgebiete umfaßt verschiedene Gebirgssümpfe, Parinari-Regenwald, afromontanen Nebelwald, Bambuswald, Hagenia-Hypericum-Wald, Baumheiden- und Paramostufe mit afroalpiner Vegetation. Die Arbeit stellt den Verlauf und die Mechanismen der Vegetationsentwicklung auf ehemaligen Agrarflächen innerhalb der Nebelwaldzone im Südwesten Ugandas dar. Hierbei wurde die direkte mit der indirekten Methode der Sukzessionsforschung kombiniert. Die Bedeutung potentieller Vektoren des Diasporen-Eintrags in die Sukzessionsflächen, wie zum Beispiel Büffel und Vögel, wurde mit Hilfe von Kot-Analysen eingeschätzt. Um das Potential der Bodensamenbank für die Regeneration der Vegetation beurteilen zu können, wurden Bodenproben aus den Sukzessionsflächen im Auflaufverfahren auf ihren Gehalt an lebensfähigen Diasporen untersucht. Die qualitativen und quantitativen Änderungen des Artenspektrums im Sukzessionsverlauf werden mit Hilfe der pflanzensoziologischen Methode anhand von Tabellenvergleichen analysiert und führen zur Definition von 17 Pflanzengesellschaften in drei Formationen. Ackerwildkrautfluren und afromontanes Grasland (Formation I) sowie die Formation der Sekundärgebüsche mit Adlerfarn (Formation II) können in jeweils zwei Gesellschaftsgruppen eingeteilt werden, die durch Charakterarten gekennzeichnet sind. Während die frühen Sukzessionstadien den Einfluß des vorangegangenen landwirtschaftlichen Nutzungstyps (Getreideanbau oder Hackfruchtkulturen) deutlich widerspiegeln, bestimmen im weiteren Verlauf der sekundären Sukzession Standortfaktoren (Höhenlage und Entfernung zum Primärwald) die Gesellschaften. Innerhalb der frühen Sukzession (Formation I) wird die Dynamik der Parameter Artenzahl, Vegetationsstruktur, Gesamtartmächtigkeit, Lebensformen, Ausbreitungssyndrom, chorologische Gruppen und Habitattypen-Indikatoren analysiert. Neben der Zunahme der Artenzahl, der Vegetationshöhe und der Gesamtartmächtigkeit wird hier besonders die Diversifizierung des Lebensformenspektrums und der Wechsel von einer epizoochoren in eine endozoochore Phase im Sukzessionsverlauf deutlich. Der zu Sukzessionsbeginn neophytische Charakter der Vegetation geht nach 17 Monaten stark zurück und weicht einem von afromontanen Florenelementen geprägten Grasland. Die Analyse der Habitattypen-Indikatoren verdeutlicht den allmählich zurückgehenden ruderalen Charakter und die zunehmende Bedeutung der waldrandtypischen Arten. Die der Sukzession in der Untersuchungsregion zugrundeliegenden Mechanismen (Diasporenvorrat im Boden, die Rolle der Avifauna und von herbivoren Großsäugern als Ausbreitungsvektoren von Diasporen sowie der Beweidungseinfluß) werden analysiert und verdeutlichen die zeitlich begrenzte Bedeutung des Diasporenvorrats im Boden im Sukzessionsverlauf und verweisen auf den hohen Einfluß der Zoochorie. Die Methode des 'Impfens' degradierter Standorte mit Bodenmaterial aus Waldbereichen wird vorgeschlagen. Mit einem Schwerpunkt auf Renaturierungs-Strategien degradierter Standorte im Bereich des afromontanen Nebelwaldes werden für die drei Untersuchungsgebiete konkrete Management-Empfehlungen gegeben. Die Einrichtung sogenannter 'multiple use' Zonen innerhalb der gefährdeten afromontanen Ökosysteme, die gleichzeitig Lebensräume der vom Aussterben bedrohten Berggorillas (Gorilla gorilla beringei) darstellen, wird als unverträglich mit den Schutzzielen eingeschätzt.Secondary succession in afromontane forest - Dynamics, mechanisms and conservation of the biodiversity in two habitats of the mountain gorilla (Mgahinga Gorilla National Park and Bwindi Impenetrable National Park) and in Echuya Forest Reserve, Uganda Based on the definition of 17 old-field plant communities in the afromontane forest region of south-west Uganda the dynamics of early secondary succession are analysed. Beside other phenomena, the resilience of the afromontane flora versus neophytes, the diversification of life form spectra and the importance of endozoochoric plant species with time are demonstrated. Several mechanisms of secondary succession in the study area are determined. The regeneration potential of the soil seed bank is limited in its time scale, as it contains no primary forest species but it could be used to speed up and enrich the early secondary succession artificially. The study of the avifauna and the buffalo population as seed-dispersers demonstrates the importance of the animal - plant-interaction on secondary succession. With a focus on restoration ecology of afromontane ecosystems some advices for the management of deforested areas are given. The evaluation of sustainable use activities within multiple-use zones reveals their incompatibility with the conservation of the only two habitats of the endangered mountain gorilla (Gorilla gorilla beringei)

O ENSINO DA “NORMA PADRÃO” X VARIAÇÃO LINGÜÍSTICA SOB A PERSPECTIVA DA SOCIOLINGÜÍSTICA INTERACIONAL

Que existe uma crise no sistema educacional, todos estão cansados de saber, mas o que os professores, escola e sociedade têm feito para mudar este quadro? O objeto desta pesquisa consiste no papel do professor como mediador, tendo como objetivo encontrar maneiras de se trabalhar em sala de aula a “norma padrão”, mas sempre considerando as variações lingüísticas de seus alunos, partindo do que o aluno já sabe sobre a língua, para que a partir daí ele próprio possa construir novos conhecimentos. O objetivo principal desta pesquisa consiste na reflexão do uso da língua e valorização da mesma, tendo como viés a Lingüística Aplicada. Espera-se através deste estudo provocar nos professores uma reflexão sobre o ensino que temos e o ensino que queremos, para que assim possa-se melhorar a prática e consequentemente, fazer com que a aprendizagem da língua realmente aconteça, tornando-a significativa para o aluno

START lipid/sterol-binding domains are amplified in plants and are predominantly associated with homeodomain transcription factors

BACKGROUND: In animals, steroid hormones regulate gene expression by binding to nuclear receptors. Plants lack genes for nuclear receptors, yet genetic evidence from Arabidopsis suggests developmental roles for lipids/sterols analogous to those in animals. In contrast to nuclear receptors, the lipid/sterol-binding StAR-related lipid transfer (START) protein domains are conserved, making them candidates for involvement in both animal and plant lipid/sterol signal transduction. RESULTS: We surveyed putative START domains from the genomes of Arabidopsis, rice, animals, protists and bacteria. START domains are more common in plants than in animals and in plants are primarily found within homeodomain (HD) transcription factors. The largest subfamily of HD-START proteins is characterized by an HD amino-terminal to a plant-specific leucine zipper with an internal loop, whereas in a smaller subfamily the HD precedes a classic leucine zipper. The START domains in plant HD-START proteins are not closely related to those of animals, implying collateral evolution to accommodate organism-specific lipids/sterols. Using crystal structures of mammalian START proteins, we show structural conservation of the mammalian phosphatidylcholine transfer protein (PCTP) START domain in plants, consistent with a common role in lipid transport and metabolism. We also describe putative START-domain proteins from bacteria and unicellular protists. CONCLUSIONS: The majority of START domains in plants belong to a novel class of putative lipid/sterol-binding transcription factors, the HD-START family, which is conserved across the plant kingdom. HD-START proteins are confined to plants, suggesting a mechanism by which lipid/sterol ligands can directly modulate transcription in plants

5SRNAdb: an information resource for 5S ribosomal RNAs

Ribosomal 5S RNA (5S rRNA) is the ubiquitous RNA component found in the large subunit of ribosomes in all known organisms. Due to its small size, abundance and evolutionary conservation 5S rRNA for many years now is used as a model molecule in studies on RNA structure, RNA–protein interactions and molecular phylogeny. 5SRNAdb (http://combio.pl/5srnadb/) is the first database that provides a high quality reference set of ribosomal 5S RNAs (5S rRNA) across three domains of life. Here, we give an overview of new developments in the database and associated web tools since 2002, including updates to database content, curation processes and user web interfaces

ENSINO DE LÍNGUA INGLESA NAS SÉRIES INICIAIS

Teaching a Foreign Language isn’t a pleasant task or easy,mainly when the students aren’t motivated and they don’t see some pragmatic utility in this knowledge, in moment is the professor the responsible in excite the interest in their students, showing that is important to know another langue, in this case the English, also as to introduce classes that motivate the students. Before this problem, we put our search question for this article: - How this being concreted the education/apprehension of English Language in the primary? What is the time to introduce a new language scholar schedule in the public schools? This article will introduce some results that was obtained from observations did in a group of first grade, justified in theories of linguistic Applied psychology, and anothersciences.Ensinar uma LE não é tarefa amena ou fácil, principalmentequando os alunos não estão motivados e não vêem uma utilidade pragmática nesta aprendizagem, neste momento é o professor que se torna responsável em despertar neles o interesse, apresentando-lhes a importância de se conhecer uma segunda língua, no caso, língua inglesa, bem como apresentar aulas que por si os motive. Diante de tal problema, colocamos nossas perguntas de pesquisa para este trabalho: - Como está se concretizando o ensino/aprendizagem de Língua Inglesa nas séries iniciais? - Quando introduzir uma nova língua no currículo escolar das escolas públicas? Este trabalho apresentará alguns resultados decorrentes de observações feitas em uma turma de 1ª série, embasado em teorias advindas da Lingüística Aplicada, Psicologia e ciências afins

Promoter-based identification of novel non-coding RNAs reveals the presence of dicistronic snoRNA-miRNA genes in Arabidopsis thaliana

List of Arabidopsis mRNA genes containing Telo-box and Site II elements in 1kb upstream of TSS. (XLSX 134 kb