138 research outputs found

    Higher order conductivity corrections to the Casimir force

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    The finite conductivity corrections to the Casimir force in two configurations are calculated in the third and fourth orders in relative penetration depth of electromagnetic zero oscillations into the metal. The obtained analytical perturbation results are compared with recent computations. Applications to the modern experiments are discussed.Comment: 15 pages, 4 figure

    Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories

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    In this paper we obtain the space-time generated by a time-like current-carrying superconducting screwed cosmic string(TCSCS). This gravitational field is obtained in a modified scalar-tensor theory in the sense that torsion is taken into account. We show that this solution is comptible with a torsion field generated by the scalar field ϕ\phi . The analysis of gravitational effects of a TCSCS shows up that the torsion effects that appear in the physical frame of Jordan-Fierz can be described in a geometric form given by contorsion term plus a symmetric part which contains the scalar gradient. As an important application of this solution, we consider the linear perturbation method developed by Zel'dovich, investigate the accretion of cold dark matter due to the formation of wakes when a TCSCS moves with speed vv and discuss the role played by torsion. Our results are compared with those obtained for cosmic strings in the framework of scalar-tensor theories without taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV- Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to appear in Phys. Rev.

    Thermal correction to the Casimir force, radiative heat transfer, and an experiment

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    The low-temperature asymptotic expressions for the Casimir interaction between two real metals described by Leontovich surface impedance are obtained in the framework of thermal quantum field theory. It is shown that the Casimir entropy computed using the impedance of infrared optics vanishes in the limit of zero temperature. By contrast, the Casimir entropy computed using the impedance of the Drude model attains at zero temperature a positive value which depends on the parameters of a system, i.e., the Nernst heat theorem is violated. Thus, the impedance of infrared optics withstands the thermodynamic test, whereas the impedance of the Drude model does not. We also perform a phenomenological analysis of the thermal Casimir force and of the radiative heat transfer through a vacuum gap between real metal plates. The characterization of a metal by means of the Leontovich impedance of the Drude model is shown to be inconsistent with experiment at separations of a few hundred nanometers. A modification of the impedance of infrared optics is suggested taking into account relaxation processes. The power of radiative heat transfer predicted from this impedance is several times less than previous predictions due to different contributions from the transverse electric evanescent waves. The physical meaning of low frequencies in the Lifshitz formula is discussed. It is concluded that new measurements of radiative heat transfer are required to find out the adequate description of a metal in the theory of electromagnetic fluctuations.Comment: 19 pages, 4 figures. svjour.cls is used, to appear in Eur. Phys. J.

    Meristematic and meristematic-like fungi in Dothideomycetes

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    SUPPLEMENTARY MMATERIAL : FIG. S1. Maximum Likelihood (ML) phylogenetic tree of the ITS sequence alignment of the new genus Endophytium and related meristematic and meristematic-like fungi in Dothideomycetes. New taxa are in bold face. Thickened branches indicate full statistical support in all analyses. Confidence values for ML-BS ≥ 70 % (UFboot2/RAxML) are included near the nodes and the “-” indicates statistical support below the threshold values. The scale bar represents the expected number of changes per site. The tree was rooted to Xylaria (Xylariales, Sordariomycetes) and Sordaria (Sordariales, Sordariomycetes). Families and orders are shown in coloured blocks and indicated to the right of the tree. FIG. S2. Maximum Likelihood (ML) phylogenetic tree of the LSU sequence alignment of the new genus Endophytium and related meristematic and meristematic-like fungi in Dothideomycetes. New taxa are in bold face. Thickened branches indicate full statistical support in all analyses. Confidence values for ML-BS ≥ 70 % (UFboot2/RAxML) are included near the nodes and the “-” indicates statistical support below the threshold values. The scale bar represents the expected number of changes per site. The tree was rooted to Xylaria (Xylariales, Sordariomycetes) and Sordaria (Sordariales, Sordariomycetes). Families and orders are shown in coloured blocks and indicated to the right of the tree. FIG. S3. Maximum Likelihood (ML) phylogenetic tree of the SSU sequence alignment of the new genus Endophytium and related meristematic and meristematic-like fungi in Dothideomycetes. New taxa are in bold face. Thickened branches indicate full statistical support in all analyses. Confidence values for ML-BS ≥ 70 % (UFboot2/RAxML) are included near the nodes and the “-” indicates statistical support below the threshold values. The scale bar represents the expected number of changes per site. The tree was rooted to Xylaria (Xylariales, Sordariomycetes) and Sordaria (Sordariales, Sordariomycetes). Families and orders are shown in coloured blocks and indicated to the right of the tree. FIG. S4. Maximum Likelihood (ML) phylogenetic tree of the RPB2 sequence alignment of the new genus Endophytium and related meristematic and meristematic-like fungi in Dothideomycetes. New taxa are in bold face. Thickened branches indicate full statistical support in all analyses. Confidence values for ML-BS ≥ 70 % (UFboot2/RAxML) are included near the nodes and the “-” indicates statistical support below the threshold values. The scale bar represents the expected number of changes per site. The tree was rooted to Xylaria (Xylariales, Sordariomycetes) and Sordaria (Sordariales, Sordariomycetes). Families and orders are shown in coloured blocks and indicated to the right of the tree. TABLE S1. Summary of phylogenetic information for the different analyses in this study. TABLE S2. Species, strains/vouchers and GenBank accession numbers of sequences used in phylogenetic analyses. Newly generated sequences are in bold.Meristematic fungi are mainly defined as having aggregates of thick-walled, melanised cells enlarging and reproducing by isodiametric division. Dothideomycetes black meristematic and meristematic-like fungi have been allied to Myriangiales, which currently has two accepted families, Myriangiaceae and Elsinoaceae, with fungi mainly regarded as pathogens, parasites, saprobes and epiphytes of different plant species. This study aimed to verify the phylogenetic position using four nuclear markers (SSU, LSU, ITS and RPB2) of the incertae sedis genera associated with Myriangiales, namely Endosporium, Gobabebomyces, Lembosiniella and Phaeosclera, and the new genus, Endophytium gen. nov. (including E. albocacti sp. nov. and E. cacti sp. nov.), established for endophytic fungi occurring in cacti in Brazil. Based on morphology, lifestyle and phylogenetic inferences, these black meristematic and meristematic-like fungi cannot be accommodated in Myriangiales. Combining these results, three new orders and two new families are introduced: Endophytiales ord. nov. (including Endophytiaceae fam. nov. for Endophytium gen. nov.), Endosporiales ord. nov. (including Endosporiaceae for Endosporium) and Phaeosclerales ord. nov. (including Phaeoscleraceae fam. nov. for Phaeosclera). Gobabebomyces and Lembosiniella remained incertae sedis due to their disposition in the phylogenetic tree, that moved among clades accordingly with the gene analysed. Our results show that the inclusion of endophytic fungi obtained from plants in dry forests can contribute to the discovery of new taxa, clarify the phylogenetic position of allied taxa and confer information to the estimation of national and global fungal diversity.the Conselho Nacional de Desenvolvimento Científico e Tecnológico, the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, the Financiadora de Estudos e Projetos, the Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco, the Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG) of Brazil, CAPES, CNPq and the European Union’s Horizon 2020 research and innovation program (RISE) under the Marie Skłodowska-Curie grant agreement No. 101008129.https://fuse-journal.orghj2024BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologySDG-15:Life on lan

    Template-stripped gold surfaces with 0.4 nm rms roughness suitable for force measurements. Application to the Casimir force in the 20-100 nm range

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    Using a template-stripping method, macroscopic gold surfaces with root-mean-square (rms) roughness less than 0.4 nm have been prepared, making them useful for studies of surface interactions in the nanometer range. The utility of such substrates is demonstrated by measurements of the Casimir force at surface separations between 20 and 100 nm, resulting in good agreement with theory. The significance and quantification of this agreement is addressed, as well as some methodological aspects regarding the measurement of the Casimir force with high accuracy.Comment: 7 figure

    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 < 0.001), MCV (p < 0.001), MCH (p < 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

    Avaliação de fluxos de calor e evapotranspiração pelo modelo SEBAL com uso de dados do sensor ASTER

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    O objetivo deste trabalho foi avaliar a eficiência da aplicação do modelo SEBAL em estimar os fluxos de energia em superfície e a evapotranspiração diária, numa extensa área de cultivo de arroz irrigado, no município de Paraíso do Sul, RS, tendo como parâmetros dados do sensor ASTER. As variáveis estudadas constituem importantes parâmetros do tempo e do clima em estudos agrometeorológicos e de racionalização no uso da água. As metodologias convencionais de estimativa desses parâmetros são pontuais e geralmente apresentam incertezas, que aumentam quando o interesse é o comportamento espacial desses parâmetros. Aplicou-se o algoritmo “Surface Energy Balance Algorithm for Land” (SEBAL), em uma imagem do sensor “Advanced Spaceborne Thermal Emission and Reflection Radiometer” (ASTER). As estimativas obtidas foram comparadas com medições em campo, realizadas por uma estação micrometeorológica localizada no interior da área de estudo. As estimativas mais precisas foram as de fluxo de calor sensível e de evapotranspiração diária, e a estimativa que apresentou maior erro foi a do fluxo de calor no solo. A metodologia empregada foi capaz de reproduzir os fluxos de energia em superfície de maneira satisfatória para estudos agrometeorológicos e de rendimento de culturas.The objective of this study was to evaluate the efficiency of SEBAL model in estimating soil surface energy fluxes and daily evapotranspiration for a large area of irrigated rice farms, near the municipality of Paraíso do Sul, RS, Brazil, using data from ASTER sensor. The evaluated variables are important weather and climatic parameters for agrometeorological studies and rationalization of water use. The conventional methodologies for estimating these parameters generally present uncertainties, which increase when concern is in the spatial behavior of such parameters. The Surface Energy Balance Algorithm for Land (SEBAL) was applied in an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scene and the estimates were compared to micrometeorological data retrieved from a station located in the studied area. The most accurate modeled parameter estimatives were sensitive heat and evapotranspiration, and the one which presented the highest error was soil heat flux. The adopted methodology was able to reproduce surface energy fluxes for agrometeorological and crop yield studies

    Fungal diversity notes 1512-1610: taxonomic and phylogenetic contributions on genera and species of fungal taxa

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    This article is the 14th in the Fungal Diversity Notes series, wherein we report 98 taxa distributed in two phyla, seven classes, 26 orders and 50 families which are described and illustrated. Taxa in this study were collected from Australia, Brazil, Burkina Faso, Chile, China, Cyprus, Egypt, France, French Guiana, India, Indonesia, Italy, Laos, Mexico, Russia, Sri Lanka, Thailand, and Vietnam. There are 59 new taxa, 39 new hosts and new geographical distributions with one new combination. The 59 new species comprise Angustimassarina kunmingense, Asterina lopi, Asterina brigadeirensis, Bartalinia bidenticola, Bartalinia caryotae, Buellia pruinocalcarea, Coltricia insularis, Colletotrichum flexuosum, Colletotrichum thasutense, Coniochaeta caraganae, Coniothyrium yuccicola, Dematipyriforma aquatic, Dematipyriforma globispora, Dematipyriforma nilotica, Distoseptispora bambusicola, Fulvifomes jawadhuvensis, Fulvifomes malaiyanurensis, Fulvifomes thiruvannamalaiensis, Fusarium purpurea, Gerronema atrovirens, Gerronema flavum, Gerronema keralense, Gerronema kuruvense, Grammothele taiwanensis, Hongkongmyces changchunensis, Hypoxylon inaequale, Kirschsteiniothelia acutisporum, Kirschsteiniothelia crustaceum, Kirschsteiniothelia extensum, Kirschsteiniothelia septemseptatum, Kirschsteiniothelia spatiosum, Lecanora immersocalcarea, Lepiota subthailandica, Lindgomyces guizhouensis, Marthe asmius pallidoaurantiacus, Marasmius tangerinus, Neovaginatispora mangiferae, Pararamichloridium aquisubtropicum, Pestalotiopsis piraubensis, Phacidium chinaum, Phaeoisaria goiasensis, Phaeoseptum thailandicum, Pleurothecium aquisubtropicum, Pseudocercospora vernoniae, Pyrenophora verruculosa, Rhachomyces cruralis, Rhachomyces hyperommae, Rhachomyces magrinii, Rhachomyces platyprosophi, Rhizomarasmius cunninghamietorum, Skeletocutis cangshanensis, Skeletocutis subchrysella, Sporisorium anadelphiae-leptocomae, Tetraploa dashaoensis, Tomentella exiguelata, Tomentella fuscoaraneosa, Tricholomopsis lechatii, Vaginatispora flavispora and Wetmoreana blastidiocalcarea. The new combination is Torula sundara. The 39 new records on hosts and geographical distribution comprise Apiospora guiyangensis, Aplosporella artocarpi, Ascochyta medicaginicola, Astrocystis bambusicola, Athelia rolfsii, Bambusicola bambusae, Bipolaris luttrellii, Botryosphaeria dothidea, Chlorophyllum squamulosum, Colletotrichum aeschynomenes, Colletotrichum pandanicola, Coprinopsis cinerea, Corylicola italica, Curvularia alcornii, Curvularia senegalensis, Diaporthe foeniculina, Diaporthe longicolla, Diaporthe phaseolorum, Diatrypella quercina, Fusarium brachygibbosum, Helicoma aquaticum, Lepiota metulispora, Lepiota pongduadensis, Lepiota subvenenata, Melanconiella meridionalis, Monotosporella erecta, Nodulosphaeria digitalis, Palmiascoma gregariascomum, Periconia byssoides, Periconia cortaderiae, Pleopunctum ellipsoideum, Psilocybe keralensis, Scedosporium apiospermum, Scedosporium dehoogii, Scedosporium marina, Spegazzinia deightonii, Torula fici, Wiesneriomyces laurinus and Xylaria venosula. All these taxa are supported by morphological and multigene phylogenetic analyses. This article allows the researchers to publish fungal collections which are important for future studies. An updated, accurate and timely report of fungus-host and fungus-geography is important. We also provide an updated list of fungal taxa published in the previous fungal diversity notes. In this list, erroneous taxa and synonyms are marked and corrected accordingly

    Viabilidade de ovos de Aedes aegypti (Diptera, Culicidae) em diferentes condições de armazenamento em Manaus, Amazonas, Brasil

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    The viability of Aedes aegypti eggs was assessed in the Amazon region. The eggs were maintained under different conditions: indoors (insectarium) and outdoors (natural environment), as well as in different storage types (plastic cup, paper envelope, plastic bag) for different days. Egg viability was measured as the mean of hatchings observed from egg-bearing sheets of filter paper immersed in water, using three sheets randomly selected from each storage type and at both sites. There were significant differences in the viability of Ae. aegypti eggs with respect to the location (F=30.40; DF=1; P<0.0001), storage type (F=17.66; DF=2; P<0.0001), and time of storage (F=49.56; DF=9; P<0.0001). The interaction between storage site versus storage type was also significant (F=15.96; DF=2; P<0.0001). A higher hatching mean was observed for the eggs kept in the insectarium than for those outdoors (32.38 versus 7.46). Hatching rates of egg batches stored for 12 to 61 days ranged between 84 and 90%. A reduction was observed between 89 and 118 days, with values of 63 and 48%, respectively. With respect to type of storage, mean egg hatching was higher for the eggs in plastic cups (44.46). It was concluded that the viability of the eggs of Ae. aegypti in the Amazon region remains high up to 4 months, after which it declines drastically, although in this study hatching occurred for up to 8 months in very low percentages. © 2017, Instituto Internacional de Ecologia. All rights reserved
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