Ocorrencia e abundância de espécies de plantas ameaçadas de extinção no entorno do reservatório da UHE Barra Grande.

Modelos de ocorrência e abundância de espécies são ferramentas atuais que devem ser incorporadas na conservação da biodiversidade no entorno de reservatórios de usinas hidroelétricas, prevendo ou planejando ações necessárias para mitigar os impactos ambientais destes empreendimentos. Neste estudo, nossos objetivos foram: modelar a ocorrência e abundância de espécies de plantas ameaçadas de extinção, verificar a relação entre a ocorrência prevista e a abundância observada e avaliar se os modelos baseados em abundância são mais eficientes em predizer a ocorrência do que aqueles baseados em dados de ocorrência (0/1). Representantes individuais de nove espécies (Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae), Butia eriospatha (Mart. ex Drude) Becc. (Arecaceae), Clethra scabra Pers. (Clethraceae), Dicksonia sellowiana (Presl.) Hook. (Dicksoniaceae), Erythrina falcata Benth. (Fabaceae), Maytenus ilicifolia (Schrad.) Planch. (Celastraceae), Myrocarpus frondosus Allemão (Fabaceae), Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) e Trithrinax brasiliensis Mart (Arecaceae)) foram contados em 388 parcelas (10x50m) aleatoriamente alocadas e georreferenciadas no entorno do reservatório da UHE Barra Grande (SC/RS). Modelamos sua relação com 15 variáveis ambientais utilizando dados de ocorrência (GLM) e abundância (Modelos Hurdle e Zero-inflado). Em geral, os modelos de ocorrência foram mais precisos do que os modelos de abundância. Para todas as espécies, a abundância observada foi correlacionada com a probabilidade de ocorrência, sugerindo que estudos futuros poderiam utilizar esta informação, em vez da abundância. Reconstruir padrões de abundância e de ocorrência é uma importante ferramenta para o planejamento de ações de conservação e manejo de espécies ameaçadas, permitindo que sejam indicadas as melhores áreas para a coleta e reintrodução de germoplasma vegetal ou mesmo a escolha de áreas de conservação com maior probabilidade de manter populações viáveis

Methanol Oxidation Genes in the Marine Methanotroph Methylomonas sp. Strain A4

Methanol dehydrogenase has been purified from the type I marine methanotroph Methylomonas sp. strain A4 and found to be similar to other methanol dehydrogenase enzymes in subunit composition, molecular mass, and N-terminal sequence of the two subunits. A heterologous gene probe and a homologous oligonucleotide have been used to identify a DNA fragment from Methylomonas sp. strain A4 which contains moxF, the gene encoding the large subunit of methanol dehydrogenase. Protein expression experiments with Escherichia coli, immunoblotting of expression extracts, and partial DNA sequence determination have confirmed the presence of moxF on this DNA fragment. In addition, expression and immunoblot experiments have shown the presence of the genes for the small subunit of methanol dehydrogenase (moxI) and for the methanol dehydrogenase-specific cytochrome c (moxG). The moxG gene product has been shown to be cytochrome c552. The expression experiments have also shown that two other genes are present on this DNA fragment, and our evidence suggests that these are the homologs of moxJ and moxR, whose functions are unknown. Our data suggest that the order of these genes in Methylomonas sp. strain A4 is moxFJGIR, the same as in the facultative methylotrophs. The transcriptional start site for moxF was mapped. The sequence 5' to the transcriptional start does not resemble other promoter sequences, including the putative moxF promoter sequence of facultative methylotrophs. These results suggest that although the order of these genes and the N-terminal amino acid sequence of MoxF and MoxI are conserved between distantly related methylotrophs, the promoters for this gene cluster differ substantially

GENERIC IDENTITY OF PHORADENDRON RUSBYI (VISCACEAE) AND A NEW RECORD FOR ARGENTINA

Durante la revisión de herbarios en la Argentina se encontró un ejemplar de Phoradendron rusbyi, que representa la tercera colección de esta especie y una nueva cita para la flora de este país. Esta especie es una planta pequeña y áfila, miembro del grupo de hiperparásitas, que fue encontrada en una colección mixta, parasitando Phoradendron bathyoryctum. Se incluye una descripción morfológica de la especie y se confirma su inclusión en el género Phorandendron. Palabras clave. Argentina; flora; hiperparásitas; Phoradendron; Viscaceae. During a review of herbaria in Argentina we found a specimen of Phoradendron rusbyi, which represents the third collection of the species and a new record for the flora of Argentina. This species is a little aphyllous plant, being a member of the group of hyperparasitic mistletoes, and was found in a mixed collection, parasitizing Phoradendron bathyoryctum. A morphological description of the species is provided, and its inclusion in Phoradendron confirmed

Stochastic analysis of surface roughness

For the characterization of surface height profiles we present a new stochastic approach which is based on the theory of Markov processes. With this analysis we achieve a characterization of the complexity of the surface roughness by means of a Fokker-Planck or Langevin equation, providing the complete stochastic information of multiscale joint probabilities. The method was applied to different road surface profiles which were measured with high resolution. Evidence of Markov properties is shown. Estimations for the parameters of the Fokker-Planck equation are based on pure, parameter free data analysis

Etched Glass Surfaces, Atomic Force Microscopy and Stochastic Analysis

The effect of etching time scale of glass surface on its statistical properties has been studied using atomic force microscopy technique. We have characterized the complexity of the height fluctuation of a etched surface by the stochastic parameters such as intermittency exponents, roughness, roughness exponents, drift and diffusion coefficients and find their variations in terms of the etching time.Comment: 5 pages, 6 figures

Multiple myeloma cells alter the senescence phenotype of bone marrow mesenchymal stromal cells under participation of the DLK1-DIO3 genomic region

Background: Alterations and senescence in bone marrow mesenchymal stromal cells of multiple myeloma patients (MM-BMMSCs) have become an important research focus. However the role of senescence in the pathophysiology of MM is not clear. Methods: Correlation between senescence, cell cycle and microRNA expression of MM-BMMSCs (n = 89) was analyzed. Gene expression analysis, copy number analysis and methylation specific PCR were performed by Real-Time PCR. Furthermore, cyclin E1, cyclin D1, p16 and p21 genes were analyzed at the protein level using ELISA. Cell cycle and senescence were analyzed by FACS. MiRNA transfection was performed with miR-485-5p inhibitor and mimic followed by downstream analysis of senescence and cell cycle characteristics of MM-BMMSCs. Results were analyzed by Mann-Whitney U test, Wilcoxon signed-rank test and paired t-test depending on the experimental set up. Results: MM-BMMSCs displayed increased senescence associated beta-galactosidase activity (SA-betaGalA), cell cycle arrest in S phase and overexpression of microRNAs. The overexpressed microRNAs miR-485-5p and miR-519d are located on DLK1-DIO3 and C19MC, respectively. Analyses revealed copy number accumulation and hypomethylation of both clusters. KMS12-PE myeloma cells decreased SA-betaGalA and influenced cell cycle characteristics of MM-BMMSCs. MiR-485-5p was significantly decreased in co-cultured MM-BMMSCs in connection with an increased methylation of DLK1-DIO3. Modification of miR-485-5p levels using microRNA mimic or inhibitor altered senescence and cell cycle characteristics of MM-BMMSCs. Conculusions: Here, we show for the first time that MM-BMMSCs have aberrant methylation and copy number of the DLK1-DIO3 and C19MC genomic region. Furthermore, this is the first study pointing that multiple myeloma cells in vitro reduce both the senescence phenotype of MM-BMMSCs and the expression of miR-223 and miR-485-5p. Thus, it is questionable whether senescence of MM-BMMSCs plays a pathological role in active multiple myeloma or is more important when cell interaction with myeloma cells is inhibited. Furthermore, we found that MiR-485-5p, which is located on the DLK1-DIO3 cluster, seems to participate in the regulation of senescence status and cell cycle characteristics of MM-BMMSCs. Thus, further exploration of the microRNAs of DLK1-DIO3 could provide further insights into the origin of the senescence state and its reversal in MM-BMMSCs