109 research outputs found

    Writing and literacy in Indonesia

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    published or submitted for publicationis peer reviewe

    A metric to quantify analogous conditions and rank environmental layers

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    Analogous conditions in environmental variables are expected because environments are spatially autocorrelated and often present similar combinations over geographic space. That similar environmental combinations may be found at different localities provides a crucial basis for correlative species distribution modeling. An absolutely analogous variable is constant, while a non-analogous variable has no-repeating values, yet no current method allows researchers to quantify intermediate degrees of analogous conditions and rank environmental layers. I approached this issue from the perspective of dual-space correspondence, in which (a) variable range and modal frequency have a theoretical inverse relationship (y ∝ x-1), and (b) modal values of frequency are limited by the number of pixels in a given raster layer. For two geographic extents and two resolutions (2.5’ and 10’), I obtained range and modal frequency of 19 bioclimatic variables and 5 reference variables. Then, I measured Euclidean distances from candidate variables to the non-analogous variable as a metric for degree of analogous conditions, which were used to rank variables. Bioclimatic layers were plotted in log-log scatterplots of range vs. modal frequency; variables were located inside the upper-right triangle (except for one set), and no layer fit the inverse model. Temperature variables presented higher degrees of analogous conditions than precipitation for South America and the Araucaria Moist Forests ecoregion. Geographic extent and pixel resolution changed the degree of analogous conditions of derived variables (quarterly and monthly); however, a pattern of change was not observed, which suggested ad hoc hypotheses on geographic and temporal idiosyncrasies. Variables with high contribution in previous SDM/ENM studies (e.g., temperature seasonality and annual precipitation) showed low degree of analogous conditions. It is expected that heterogeneous layers would generate better correlational geographic distributional predictions than analogous variables, even though this hypothesis remains untested. Ranking layers can provide grounds for selecting variables in distribution and niche modeling, particularly as regards interpreting spatial projection and transferability. Alternatively, ranking can be used to compare degrees of analogous conditions of the same layer in different time spans

    Processo aperfeiçoado para reduzir o peso molecular de elastômeros

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    ConcedidaRefere-se a polímeros de alto peso molecular, pela ação de agentes catalisadores. Consta o processo em fazer a redução do peso molecular de polímeros de alto peso molecular pela ação de catalisadores metálicos de elementos de transição ou seus sais. O polímero ou copolímero pode estar dissolvido em solvente adequado. A redução do peso molecular é ativada pelo calor da pressão

    Anais e resumos do XXXII Congresso Brasileiro de Zoologia: Desafios e Perspectivas para a zoologia na América Latina

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    Annals, meeting reports, symposia and abstracts of the 32rd Brazilian Congress of Zoology.Anais, resumos de reuniões, simpósios e resumos apresentados no XXXII Congresso Brasileiro de Zoologia.O Congresso Brasileiro de Zoologia é um evento bienal que visa congregar pessoas interessadas em estudos zoológicos (profissionais, estudantes, professores e pesquisadores); promover, incentivar e divulgar os avanços nos estudos da fauna neotropical; incrementar a formação e o reconhecimento do zoólogo como elemento indispensável no inventário e estudo do patrimônio natural dos países, especialmente na América Latina, região com maior diversidade de espécies no mundo. Esta 32ª. edição foi realizada entre os dias 26 de fevereiro a 02 de março de 2018 em Foz do Iguaçu, Paraná, pelo Programa de Pós-raduação em Biodiversidade Neotropical da Universidade Federal da Integração Latino-Americana. Teve por tema “Desafios e perspectivas para a Zoologia na América Latina”, visando promover uma discussão prolífica sobre a integração de pessoas de diferentes países para o avanço da pesquisa e conservação da diversidade animal da Região Neotropical. O tema é considerado essencial para uma região de tríplice fronteira, como Foz do Iguaçu, de grande diversidade natural e cultural e, em uma escala mais ampla, considerado importante para toda a América Latina. A programação científica contou com oito palestras plenárias de pesquisadores internacionalmente renomados e 17 simpósios de temas específicos, cobrindo temas de grande interesse para a Zoologia brasileira. Participaram do evento 1441 congressistas e foram apresentados 1235 trabalhos, sendo 219 em sessões orais. Destaca-se que a maioria dos participantes foi de graduandos (641) e pós-graduandos (292) e maioria de mulheres (61%). Tivemos congressistas de 12 países além do Brasil. Esta edição do CBZ refletiu claramente o quanto a zoologia no Brasil é realizada por colaborações e o quão diversa é nossa comunidade. Agradecemos a participação de todos os congressistas, convidados, monitores, patrocinadores e equipe de apoio, que contribuíram para que esta edição do evento fosse um sucesso.Itaipu Binacional, Petrobras, Eletrobras Furnas, Ministério de Minas e Energia, Governo Federal. Apoio: CNPq, CAPES, Parque das Aves, Parque Tecnológico Itaipu, Iguassu Convention & Visitors Bureau

    Novel regulators of stem cell fates identified by a multivariate phenotype screen of small compounds on human embryonic stem cell colonies

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    Understanding the complex mechanisms that govern the fate decisions of human embryonic stem cells (hESCs) is fundamental to their use in cell replacement therapies. The progress of dissecting these mechanisms will be facilitated by the availability of robust high-throughput screening assays on hESCs. In this study, we report an image-based high-content assay for detecting compounds that affect hESC survival or pluripotency. Our assay was designed to detect changes in the phenotype of hESC colonies by quantifying multiple parameters, including the number of cells in a colony, colony area and shape, intensity of nuclear staining, and the percentage of cells in the colony that express a marker of pluripotency (TRA-1-60), as well as the number of colonies per well. We used this assay to screen 1040 compounds from two commercial compound libraries, and identified 17 that promoted differentiation, as well as 5 that promoted survival of hESCs. Among the novel small compounds we identified with activity on hESC are several steroids that promote hESC differentiation and the antihypertensive drug, pinacidil, which affects hESC survival. The analysis of overlapping targets of pinacidil and the other survival compounds revealed that activity of PRK2, ROCK, MNK1, RSK1, and MSK1 kinases may contribute to the survival of hESCs. (C) 2010 Elsevier B.V. All rights reserved

    Autonomous growth potential of leukemia blast cells is associated with poor prognosis in human acute leukemias

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    We have described a severe combined immunodeficiency (SCID) mouse model that permits the subcutaneous growth of primary human acute leukemia blast cells into a measurable subcutaneous nodule which may be followed by the development of disseminated disease. Utilizing the SCID mouse model, we examined the growth potential of leukemic blasts from 133 patients with acute leukemia, (67 acute lymphoblastic leukemia (ALL) and 66 acute myeloid leukemia (AML)) in the animals after subcutaneous inoculation without conditioning treatment. The blasts displayed three distinct growth patterns: "aggressive", "indolent", or "no tumor growth". Out of 133 leukemias, 45 (33.8%) displayed an aggressive growth pattern, 14 (10.5%) displayed an indolent growth pattern and 74 (55.6%) did not grow in SCID mice. The growth probability of leukemias from relapsed and/or refractory disease was nearly 3 fold higher than that from patients with newly diagnosed disease. Serial observations found that leukemic blasts from the same individual, which did not initiate tumor growth at initial presentation and/or at early relapse, may engraft and grow in the later stages of disease, suggesting that the ability of leukemia cells for engraftment and proliferation was gradually acquired following the process of leukemia progression. Nine autonomous growing leukemia cell lines were established in vitro. These displayed an aggressive proliferation pattern, suggesting a possible correlation between the capacity of human leukemia cells for autonomous proliferation in vitro and an aggressive growth potential in SCID mice. In addition, we demonstrated that patients whose leukemic blasts displayed an aggressive growth and dissemination pattern in SClD mice had a poor clinical outcome in patients with ALL as well as AML. Patients whose leukemic blasts grew indolently or whose leukemia cells failed to induce growth had a significantly longer DFS and more favorable clinical course

    Molecular characterization of mutant TP53 acute myeloid leukemia and high-risk myelodysplastic syndrome

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    Substantial heterogeneity within mutant TP53 acute myeloid leukemia (AML) and myelodysplastic syndrome with excess of blast (MDS-EB) precludes the exact assessment of prognostic impact for individual patients. We performed in-depth clinical and molecular analysis of mutant TP53 AML and MDS-EB to dissect the molecular characteristics in detail and determine its impact on survival. We performed next-generation sequencing on 2200 AML/MDS-EB specimens and assessed the TP53 mutant allelic status (mono- or bi-allelic), the number of TP53 mutations, mutant TP53 clone size, concurrent mutations, cytogenetics, and mutant TP53 molecular minimal residual disease and studied the associations of these characteristics with overall survival. TP53 mutations were detected in 230 (10.5%) patients with AML/MDS-EB with a median variant allele frequency of 47%. Bi-allelic mutant TP53 status was observed in 174 (76%) patients. Multiple TP53 mutations were found in 49 (21%) patients. Concurrent mutations were detected in 113 (49%) patients. No significant difference in any of the aforementioned molecular characteristics of mutant TP53 was detected between AML and MDS-EB. Patients with mutant TP53 have a poor outcome (2-year overall survival, 12.8%); however, no survival difference between AML and MDS-EB was observed. Importantly, none of the molecular characteristics were significantly associated with survival in mutant TP53 AML/MDS-EB. In most patients, TP53 mutations remained detectable in complete remission by deep sequencing (73%). Detection of residual mutant TP53 was not associated with survival. Mutant TP53 AML and MDS-EB do not differ with respect to molecular characteristics and survival. Therefore, mutant TP53 AML/MDS-EB should be considered a distinct molecular disease entity

    Reduced SLIT2 is Associated with Increased Cell Proliferation and Arsenic Trioxide Resistance in Acute Promyelocytic Leukemia

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    Simple Summary In solid tumors, the altered expression of embryonic genes such as the SLIT-ROBO family has been associated with poor prognosis, while little is known about their role in acute myeloid leukemia (AML). Previous studies reported frequent hypermethylation of SLIT2 mediated by the methyltransferase enzyme EZH2 and more recently the PML protein, which are commonly found to be aberrantly expressed in AML. Here, we aim to assess retrospectively the clinical relevance of the SLIT2 gene in acute promyelocytic leukemia, a homogenous subtype of AML. We demonstrated that reduced SLIT2 expression was associated with high leukocyte counts and reduced overall survival in different APL cohorts. STLI2 treatment decreased APL growth, while SLIT2 knockdown accelerated cell cycle progression and proliferation. Finally, reduced expression of SLIT2 in murine APL blasts resulted in fatal leukemia associated with increased leukocyte counts in vivo. These findings demonstrate that SLIT2 can be considered as a prognostic marker in APL, and a potential candidate for clinical studies of a more heterogeneous disease, such as AML. The SLIT-ROBO axis plays an important role in normal stem-cell biology, with possible repercussions on cancer stem cell emergence. Although the Promyelocytic Leukemia (PML) protein can regulate SLIT2 expression in the central nervous system, little is known about SLIT2 in acute promyelocytic leukemia. Hence, we aimed to investigate the levels of SLIT2 in acute promyelocytic leukemia (APL) and assess its biological activity in vitro and in vivo. Our analysis indicated that blasts with SLIT2(high) transcript levels were associated with cell cycle arrest, while SLIT2(low) APL blasts displayed a more stem-cell like phenotype. In a retrospective analysis using a cohort of patients treated with all-trans retinoic acid (ATRA) and anthracyclines, high SLIT2 expression was correlated with reduced leukocyte count (p = 0.024), and independently associated with improved overall survival (hazard ratio: 0.94; 95% confidence interval: 0.92-0.97; p <0.001). Functionally, SLIT2-knockdown in primary APL blasts and cell lines led to increased cell proliferation and resistance to arsenic trioxide induced apoptosis. Finally, in vivo transplant of Slit2-silenced primary APL blasts promoted increased leukocyte count (p = 0.001) and decreased overall survival (p = 0.002) compared with the control. In summary, our data highlight the tumor suppressive function of SLIT2 in APL and its deteriorating effects on disease progression when downregulated
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