NORs inheritance analysis in crossings including individuals from two stocks of rainbow trout (Oncorhynchus mykiss)

Silver nitrate staining of rainbow trouts (Oncorhynchus mykiss) chromosomes, for the identification of the nucleolar organizing regions (NORs), revealed that in individuals from Nucleo Experimental de Salmonicultura de Campos do Jordao (Brazil) NORs were located in the long arms of a submetacentric pair while in specimens from Mount Shasta (USA) NORs were located in the short arms of a submetacentric pair. Cytogenetic analysis of the offspring, obtained through artificial crosses including individuals from both stocks, allowed the identification of NORs in two submetacentric chromosomes, one in the short arms and the other in the long arms, confirming the effectiveness of the hybridization process. Complementary results obtained using the FISH technique with 18S and 5S rDNA probes showed that NOR-bearing chromosomes exhibited a cluster of 5S genes located in tandem with the 18S gene cluster in both stocks. The results allow us to suggest that the difference in NOR-bearing chromosomes found between the two stocks is likely to be due to a pericentric inversion involving the chromosome segment where 18S and 5S rDNA genes are located. The presence of ribosomal genes in the long arms of a submetacentric chromosome is apparently a particular characteristic of the rainbow trout stock of Campos do Jordao and might be used as a chromosome marker in studies of controlled crosses in this species.

Respostas fisiológicas de diferentes clones de eucalipto sob diferentes regimes de irrigação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mitochondrial genotype segregation and effects during mammalian development: Applications to biotechnology

Mitochondria are endosymbiotic organelles responsible for energy production in practically every eukaryotic cell. Their uniparental fashion of inheritance, maternally inherited in mammals, and the homogeneity of mitochondrial DNA (mtDNA) within individuals and matrilineages, are biological phenomena that remain unexplained. This paper reviews some of the recent findings on mitochondrial influences on the manner in which embryos develop and how their genotypes are inherited in mammals, with particular emphasis on the genetic bottleneck effect. Animal models carrying a mix of mtDNAs (heteroplasmic) have been produced by karyoplast and cytoplast transplantation to analyze the segregation patterns at different stages during embryogenesis, in fetuses and offspring. Comparisons performed between murine and bovine reveal interesting changes in segregation and replication of transplanted mtDNAs. We have recently obtained Bos indicus and Bos taurus fetuses and calves from embryos reconstructed using enucleated polymorphic oocytes of Bos taurus origin. These and other findings on mitochondrial biology will have important implications in determining the cytoplasmic genotype of clones and in the preservation of endangered breeds and species. (C) 1999 by Elsevier B.V.

INHERITANCE of CUCUMBER TOLERANCE TO ZUCCHINI YELLOW MOSAIC VIRUS

Studies were carried out in Brazil to study the inheritance of tolerance to Zucchini yellow mosaic virus (ZYMV) in cucumber cv. Formosa. This cultivar was individually crossed with two cucumber lines from different varietal types (L(b) from a Brazilian type, and L(j) from a Japanese type), both susceptible to the virus. Two experiments, one for each line, were separately carried out, where 6 treatments (parents, generations F1, F2 and F1BC1 for both parents) were evaluated in a randomized block design with 5 repetitions. Cotyledons of 2-week-old cucumber seedlings were inoculated with ZYMV. Only the plants that did not show symptoms up to 63 days post inoculation were considered as tolerant. A chi-square (chi(2)) analysis for assessing segregation from F2 and both F1BC1, led to the conclusion that the tolerance found in cv. Formosa is determined by a recessive gene.

As Memórias de Lacroix: a instrução pública na França revolucionária, em geral, e o ensino de Matemática, em particular

O artigo - um exame hermenêutico do livro Essais sur l'enseignement en général, et sur celui des mathématiques en particulier, de 1805, de Sylvestre-François Lacroix, enfatizando sua segunda parte, na qual o autor discute seu Curso de Matemática Elementar, uma série de manuais escolares elaborados para a Escola Central das Quatro Nações - tem sua fundamentação ligada à Hermenêutica de Profundidade de Thompson conjugada a procedimentos de investigação textual sugeridos por Genette quanto aos paratextos editoriais. Defende que o livro de Lacroix é uma obra auto-referencial, de cunho claramente autobiográfico, que responde mais aos ideais iluministas da França do Setecentos que às perspectivas do século XIX, quando a obra circulou, tendo sido reeditada por quatro vezes, sob Napoleão, na primeira metade do Oitocentos. Raramente focalizado em trabalhos de pesquisa, o livro - cujas edições estão disponíveis eletronicamente - tem uma única tradução, ainda inédita, para o português.

Crossover between macroscopic and mesoscopic regimes of vortex interactions in type-II superconductors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho de escolares com e sem dificuldades de aprendizagem de ensino particular em habilidade fonológica, nomeação rápida, leitura e escrita

OBJETIVOS: caracterizar e comparar o desempenho de escolares com e sem dificuldades de aprendizagem no ensino particular em habilidades fonológicas, nomeação rápida, leitura e escrita. MÉTODOS: participaram desse estudo 60 escolares de 2ª a 4ª séries de escola de ensino particular, distribuídos em 6 grupos, sendo cada grupo composto por 10 escolares, sendo 3 grupos de escolares com dificuldades de aprendizagem e 3 grupos de escolares sem dificuldades de aprendizagem. Como procedimentos, foram realizadas a prova de nomeação automática rápida, a de consciência fonológica e a prova de leitura oral e escrita sob ditado. RESULTADOS: os resultados desse estudo evidenciaram desempenho superior dos escolares sem dificuldades de aprendizagem em relação àqueles com dificuldades. Os escolares com dificuldades de aprendizagem apresentaram maior relação velocidade/tempo em tarefas de nomeação e, conseqüentemente, desempenho inferior em tarefas de consciência fonológica e leitura e escrita de palavras isoladas quando comparados aos sem dificuldades de aprendizagem. CONCLUSÃO: os escolares com dificuldades de aprendizagem apresentaram comprometimento na relação entre as capacidades de nomeação e automatização dos estímulos apresentados com a capacidade de acesso lexical, discriminação visual, freqüência de uso dos estímulos e competição para a apresentação do menor tempo possível na nomeação dos códigos necessários para o estabelecimento do mecanismo de conversão fonema-grafema, exigido para a realização da leitura e escrita em um sistema alfabético como o português.

Sulcus vocalis: evidence for autosomal dominant inheritance

We found evidence of autosomal dominant hereditary transmission of sulcus vocalis. Four dysphonic patients from three generations of the same family were submitted to videolaryngoscopic examination (three patients) and to direct laryngoscopy ( one patient) to diagnose the hoarseness. Sulcus vocalis was diagnosed in all four patients. The finding of four affected individuals in three generations, with vertical transmission affecting man and women, is more consistent with autosomal dominant inheritance pattern; it is an etiological model that we propose for the sulcus vocalis in this pedigree.

Supernumerary chromosome inheritance in the curimbata (Prochilodus lineatus) of the Mogi-Guacu River

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Searching for larval support for majoid families (Crustacea : Brachyura) with particular reference to Inachoididae Dana, 1851

We re-evaluated the larval support for families within majoids using the Wilcoxon signed-rank test with emphasis on Inachoididae. To accomplish our objectives, we added 10 new taxa, two of which are traditionally assigned to the family of special interest, to a previous larval database for majoids, and re-appraised the larval characters used in earlier studies. Phylogenetic analysis was performed with PAUP* using the heuristic search with 50 replicates or the branch-and-bound algorithm when possible. Multi-state transformation series were considered unordered; initially characters were equally weighted followed by successive weighting, and trees were rooted at the Oregoniidae node. Ten different topological constraints were enforced for families to evaluate tree length under the assumption of monophyly for each taxonomic entity. Our results showed that the tree length of most constrained topologies was not considerably greater than that of unconstrained analysis in which most families nested as paraphyletic taxa. This may indicate that the present larval database does not provide strong support for paraphyly of the taxa in question. For Inachoididae, although the Wilcoxon signed-rank test rejected a significant difference between unconstrained and constrained cladograms, we were unable to provide a single synapomorphy for this clade. Except for the conflicting position of Leurocyclus and Stenorhynchus, the two clades correspond to the traditional taxonomic arrangement. Among inachoidids, the clade (Anasimus (Paradasygyius (Collodes + Pyromaia))) is supported, whereas for inachids, the clade (Inachus (Macropodia + Achaeus)) is one of the most supported clades within majids. As often stated, only additional characters will provide a better test for the monophyly of Inachoididae and other families within Majoidea.

Floral anatomy of Bromeliaceae, with particular reference to the evolution of epigyny and septal nectaries in commelinid monocots

Floral anatomy is described in ten genera of Bromeliaceae, including three members of subfamily Bromelioideae, three Tillandsioideae, and four genera of the polyphyletic subfamily Pitcairnioideae (including Brocchinia, the putatively basal genus of Bromeliaceae). Bromeliaceae are probably unique in the order Poales in possessing septal nectaries and epigynous or semi-epigynous flowers. Evidence presented here from floral ontogeny, vasculature, and the relative positions of nectary and ovules indicates that there could have been one or more reversals to apparent hypogyny in Bromeliaceae, although this hypothesis requires a better-resolved phylogeny. Such evolutionary reversals probably evolved in response to specialist pollinators, and in conjunction with other aspects of floral morphology of Bromeliaceae, such as the petal appendages of some species. The ovary is initiated in an inferior position even in semi-epigynous or hypogynous species. The ovary of all so-called hypogynous Bromeliaceae is actually semi-inferior, because the septal nectary is infralocular; in these species the nectaries have a labyrinthine surface and many vascular bundles. Brocchinia differs from most other fully epigynous species in that each carpel is secretory at the apex and reproductive, rather than secretory, at the base.

Queen Replacement in Mischocyttarus (Monocyttarus) cassununga (Hymenoptera, Vespidae, Mischocyttarini): a Particular Case

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Particular solution for anomalous diffusion equation with source term

In literature the phenomenon of diffusion has been widely studied, however for nonextensive systems which are governed by a nonlinear stochastic dynamic, there are a few soluble models. The purpose of this study is to present the solution of the nonlinear Fokker-Planck equation for a model of potential with barrier considering a term of absorption. Systems of this nature can be observed in various chemical or biological processes and their solution enriches the studies of existing nonextensive systems.