133 research outputs found

    The Complex Topology of Chemical Plants

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    We show that flowsheets of oil refineries can be associated to complex network topologies that are scale-free, display small-world effect and possess hierarchical organization. The emergence of these properties from such man-made networks is explained as a consequence of the currently used principles for process design, which include heuristics as well as algorithmic techniques. We expect these results to be valid for chemical plants of different types and capacities.Comment: 7 pages, 5 figures and 1 tabl

    Characterization of alpha thalassemic genotypes by multiplex ligation-dependent probe amplification in the Brazilian population

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    Alpha-thalassemia is the most common inherited disorder of hemoglobin synthesis. Genomic deletions involving the alpha-globin gene cluster on chromosome 16p13.3 are the most frequent molecular causes of the disease. Although common deletions can be detected by a single multiplex gap-PCR, the rare and novel deletions depend on more laborious techniques for their identification. The multiplex ligation-dependent probe amplification (MLPA) technique has recently been used for this purpose and was successfully used in the present study to detect the molecular alterations responsible for the alpha-thalassemic phenotypes in 8 unrelated individuals (3 males and 5 females; age, 4 months to 30 years) in whom the molecular basis of the disease could not be determined by conventional methods. A total of 44 probe pairs were used for MLPA, covering approximately 800 kb from the telomere to the MSLN gene in the 16p13.3 region. Eight deletions were detected. Four of these varied in size from 240 to 720 kb and affected a large region including the entire alpha-globin gene cluster and its upstream regulatory element (alpha-MRE), while the other four varied in size from 0.4 to 100 kb and were limited to a region containing this element. This study is the first in Brazil to use the MLPA method to determine the molecular basis of alpha-thalassemia. The variety of rearrangements identified highlights the need to investigate all cases presenting microcytosis and hypochromia, but without iron deficiency or elevated hemoglobin A2 levels and suggests that these rearrangements may be more frequent in our population than previously estimated.162

    Sphingosine 1-phosphate promotes activation of aprine preantral follicle in vitro

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    Este estudo descreve o efeito da esfingosina 1-fosfato (S1P) no desenvolvimento de folículos pré-antrais, portanto da ativação e viabilidade de folículos caprinos cultivados in vitro. Fragmentos de ovários foram cultivados por um ou sete dias em meio essencial mínimo com diferentes concentrações de S1P (0, 1, 10, 50, 100 ou 200ng/mL). Os fragmentos de ovário foram processados para análise histológica em microscopia óptica, microscopia eletrônica e microscopia de fluorescência. O tratamento usando 1ng/mL de S1P foi capaz de manter a porcentagem de folículos normais durante o período de cultivo de sete dias. Ao final do período de cultivo, houve uma redução significativa (p<0,05) na porcentagem de folículos primordiais em todos os grupos tratados com S1P, comparados com os grupos controle (FC e CC), seguida por um aumento do número de folículos ativados (intermediários, primários e secundários). Adicionalmente, na cultura por sete dias com meio suplementado com S1P (1ng/mL), houve preservação da ultraestrutura das organelas e manteve-se a viabilidade dos folículos pré-antrais avaliados por microscopia de fluorescência. Em conclusão, após sete dias de cultura, o meio suplementado com 1ng/mL de S1P ativa o desenvolvimento de folículos pré-antrais de caprino, cultivados in situ e mantém as viabilidades oocitária e folicular.This study describes the effect of sphingosine 1-phosphate (S1P) for development of preantral follicle, therefore the activation and follicular viability of caprine follicles cultured in vitro. Ovarian fragments were cultured for 1 or 7 days in Minimum Essential Medium with different S1P concentrations (0, 1, 10, 50, 100 or 200ng/mL). All ovarian fragments were processed for histological analysis in optical microscopy, transmission electron microscopy and fluorescence analysis. The treatment using 1ng/mL of S1P was able to maintain the percentage of normal follicles with the progression of the culture from day 1 to 7. At end of the 7-day culture period there was a significant reduction (P<0.05) in the percentage of primordial follicles in all groups treated with S1P, compared with fresh control (FC) and Control Culture (CC), which was followed by an increase of activated follicles (intermediary, primary and secondary). In addition, the culture for 7 days with media supplemented with S1P with 1ng/mL preserved the ultrastructure of organelles and kept the preantral follicular viability when evaluated by fluorescence microscopy. In conclusion, after 7 days of culture, the 1ng/mL of S1P activates the development of preantral caprine follicles, cultured in situ and maintains the oocitary and follicular viability

    Prevalence Of α-thalassemia 3.7 Kb Deletion In The Adult Population Of Rio Grande Do Norte, Brazil

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    α-Thalassemia, arising from a defect in α-globin chain synthesis, is often caused by deletions involving one or both of the α-genes on the same allele. With the aim of investigating the prevalence of α-thalassemia 3.7 kb deletion in the adult population of Rio Grande do Norte, 713 unrelated individuals, between 18 and 59 years-of-age, were analyzed. Red blood cell indices were electronically determined, and A 2 and F hemoglobins evaluated by HPLC. PCR was applied to the molecular investigation of α-thalassemia 3.7 kb deletion. Eighty (11.2%) of the 713 individuals investigated presented α-thalassemia, of which 79 (11.1%) were heterozygous (-α 3.7/αα) deletions and 1 (0.1%) homozygous (-α 3.7/-α 3.7). Ethnically, heterozygous deletions were higher (24.8%) in Afro-Brazilians. Comparison of hematological parameters between individuals with normal genotype and those with heterozygous α +-thalassemia showed a statistically significant difference in the number of erythrocytes (p &lt; 0.001), MCV (p &lt; 0.001), MCH (p &lt; 0.001) and Hb A 2 (p = 0.007). This study is one of the first dedicated to investigating α-thalassemia 3.7 kb deletion in the population of the State Rio Grande do Norte state. Results obtained demonstrate the importance of investigating this condition in order to elucidate the causes of microcytosis and hypochromia. © 2012, Sociedade Brasileira de Genética. Printed in Brazil.353594598Adorno, E.V., Couto, F.D., Moura Neto, J.P., Menezes, J.F., Rêgo, M., Reis, M.G., Gonçalves, M.S., Hemoglobinopathies in newborns from Salvador, Bahia, Northeast Brazil (2005) Cad Saúde Pública, 21, pp. 292-298Bezerra, C.M., Meissner, R.V., Diagnóstico molecular da talassemia alfa + (deleção-( 3.7) em indivíduos com microcitose e/ou hipocromia atendidos no Hemocentro Dalton Barbosa Cunha em Natal, Rio Grande do Norte (2010) Rev Bras Hematol Hemoter, 32, pp. 90-91. , (Abstract in English)Borg, J., Georgitsi, M., Aleporou-Marinou, V., Kollia, P., Patrinos, G.P., Genetic recombination as a major cause of mutagenesis in the human globin gene clusters (2009) Clin Biochem, 42, pp. 1839-1850Borges, E., Wenning, M.R.S.C., Kimura, E.M., Gervásio, S.A., Costa, F.F., Sonati, M.F., High prevalence of alpha-thalassemia among individuals with microcytosis and hypochromia without anemia (2001) Braz J Med Biol Res, 34, pp. 759-762Cascudo, L.C., (1984) História do Rio Grande do Norte, p. 524. , 2 edition. Fundação José Augusto, NatalCouto, F.D., Albuquerque, A.B.L., Adorno, E.V., Moura Neto, J.P., Freitas, A.L., Oliveira, J.L.B., Reis, M.G., Gonçalves, M.S., Alpha-thalassemia-2, 3.7 kb deletion and hemoglobin AC heterozygosity in pregnancy: A molecular and hematological analysis (2003) Clin Lab Haematol, 25, pp. 29-34Dacie, J.V., Lewis, S.M., (1995) Practical Haematology., p. 608. , Churchill Livingstone, EdinburghDodé, C., Krishnamoorthy, R., Lamb, J., Rochette, J., Rapid analysis of-α 3.7 thalassaemia and ttt anti3.7 triplication by enzymatic amplification analysis (1992) Br J Haematol, 83, pp. 105-111Harteveld, L.C., Higgs, D.R., H-thalassaemia (2010) Orphanet J Rare Dis, 5, pp. 1-21Higgs, D.R., H-Thalassaemia (1993) Baillière's Clin Haematol, 6, pp. 117-150Higgs, D.R., The pathopysiology and clinical features of H thalassemia (2009) Disorders of Hemoglobin, pp. 266-295. , In: Steinberg MH, Forget BG, Higgs DR and Weatherall DJ (eds) 2 nd edition. Cambridge University Press, New YorkHiggs, D.R., Weatherall, D.J., The alpha thalassaemias (2009) Cell Mol Life Sci, 66, pp. 1154-1162Mouélé, R., Pambou, O., Feingold, J., Galactéros, F., M-thalassemia in Bantu population from Congo-Brazzaville: Its interaction with sickle cell anemia (2000) Hum Hered, 50, pp. 118-125Peres, M.J., Romão, L., Carreiro, H., Picanço, I., Batalha, L., Magalhães, H.A., Martins, M.C., Lavinha, J., Molecular basis of H-thalassemia in Portugal (1995) Hemoglobin, 19, pp. 343-352Rahim, F., Microcytic hypochromic anemia patients with thalassemia: Genotyping approach (2009) J Med, 63, pp. 101-108Sankar, V.H., Arya, V., Tewari, D., Gupta, U.R., Pradhan, M., Genotyping of alpha-thalassemia in microcytic hypochromic anemia patients from North India (2006) Indian J Med Res, 47, pp. 391-395Sonati, M.F., Farah, S.B., Ramalho, A.S., Costa, F.F., High prevalence of alpha-thalassemia in a black population of Brazil (1991) Hemoglobin, 15, pp. 309-311Souza, A.E.S., Takanashi, S.Y.L., Cardoso, G., Guerreiro, J.F., S-thalassemia (3.7 kb deletion) in a population from the Brazilian Amazon region: Santarém, Pará State (2009) Genet Mol Res, 8, pp. 477-481Steinberg, M.H., Nagel, R.L., Hemoglobins of the embryo, fetus and adult (2009) Disorders of Hemoglobin, pp. 119-135. , In: Steinberg MH, Forget BG, Higgs DR and Weatherall DJ (eds) 2 nd edition. Cambridge University Press, New YorkWagner, S.C., Castro, S.M., Gonzalez, T.P., Santin, A.P., Filippon, L., Zaleski, C.F., Azevedo, L.A., Hutz, M., Prevalence of common c-thalassemia determinants in south Brazil: Importance for the diagnosis of microcytic anemia (2010) Genet Mol Biol, 33, pp. 641-645Weatherall, D.J., Clegg, J.B., Inherited haemoglobin disorders: An increasing global health problem (2001) Bull World Health Organ, 79, pp. 704-71

    Van der Waals-Casimir-Polder interaction of an atom with a composite surface

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    We study the dispersion interaction of the van der Waals and Casimir-Polder (vdW-CP) type between a neutral atom and the surface of a metal by allowing for nonlocal electrodynamics, i.e. electron diffusion. We consider two models: (i) bulk diffusion, and (ii) diffusion in a surface charge layer. In both cases the transition to a semiconductor is continuous as a function of the conductivity, unlike the case of a local model. The relevant parameter is the electric screening length and depends on the carrier diffusion constant. We find that for distances comparable to the screening length, vdW-CP data can distinguish between bulk and surface diffusion, hence it can be a sensitive probe for surface states.Comment: v2: expanded references, statements on current status in the field. 10 pages, 6 figure

    Diving into the vertical dimension of elasmobranch movement ecology

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    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
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