146,964 research outputs found
Magma mobilization by downward-propagating decompression of the Eyjafjallajökull volcanic plumbing system
No full textDetailed observations of the 2010 Eyjafjallajökull eruptions in Iceland show seismic activity propagating vertically through the entire crust during a ten-week period of volcanic unrest comprising multiple eruption episodes. Systematic changes in magma chemistry suggest a complex magmatic plumbing system, tapping several accumulation zones at different depths containing magma of differing ages and compositions. During the eruption, a systematic downward propagation of seismicity through the crust and into the upper mantle to ~30 km depth occurred in a series of steps, each of which preceded an explosive surge in eruption rate. Here we show that the sequence of seismicity and eruptive activity may be explained by the downward propagation of a decompression wave that triggers magma release from progressively deeper sills in the crust. Comparing observations of the downward-propagating seismicity with the decompression of a series of model elastic sills suggests that each sill was 1-10 km3 in size
<i>No se sabe</i>: entrevista a Lucas Gagliardi
No full textEntrevista al Licenciado y Profesor en Letras (UNLP) Lucas Gagliardi. Se especializa en literatura en lengua inglesa y en crítica genética. Se desempeña como profesor en la Universidad Pedagógica (UNIPE), en institutos de formación docente y escuelas secundarias. Ha participado en proyectos de investigación sobre archivos de escritores, publicaciones impresas. Participa en el programa de voluntariado universitario de la Facultad de Trabajo Social (UNLP) en articulación con la Biblioteca Ambulante del Hospital de Niños dictando talleres de lectura y escritura.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de Lucas Gagliardi presentes en el repositorio.Radio Universidad Nacional de La Plat
MICROPROPAGAÇÃO DO KIWI CV. HAYWARD
No full textO presente trabalho teve como objetivo desenvolver um protocolo para a obtenção de mudas de kiwi (Actinidia chinensis Planch), cv. Hayward, por meio do cultivo in vitro de cotilédones. Utilizou-se o meio de MURASHIGE & SKOOG (1962) -- MS, suplementado com dois tipos de auxina (AIA e AIB) e uma citocinina (BAP). Foram verificados os efeitos de três doses de auxinas (0,125; 0,250 e 0,375 mg.L-1), combinadas com três doses de citocinina (0,5; 1,0 e 1,5 mg.L-1) na capacidade morfogênica dos explantes. Procedeu-se o estudo histológico dos órgãos das plântulas obtidas in vitro, e verificou-se, também, a capacidade de aclimatação das mudas ex vitro. A menor dose de AIB (0,125 mg.L-1), independentemente das doses de BAP, foi a mais eficaz na morfogênese dos explantes. Não foram verificadas alterações histológicas e anatômicas das plântulas obtidas in vitro. Aos três meses após o cultivo ex vitro dos explantes, verificou-se a sobrevivência de 88% das plantas transplantadas em condições de campo
Aetea arcuata Winston & Hayward 2012
No full textAetea arcuata Winston & Hayward, 2012 (Figs. 2–3) Aetea recta: Kirkpatrick, 1890: 504. [Brazil: Fernando de Noronha Archipelago (Pernambuco)] Aetea anguina: Vieira et al., 2008: 12 (in part). [Brazil: Pernambuco;?Espírito Santo,?Rio de Janeiro, and?Paraná] Aetea sica: Vieira et al., 2008: 12 (in part). [Brazil: Fernando de Noronha Archipelago (Pernambuco)] Aetea arcuata Winston & Hayward, 2012: 41, fig. 2. (cum syn.) [USA: Massachusetts to New York]? Aetea anguina: Almeida et al., 2015 b: 3. [Brazil: Bahia] Material examined. UFAL 0 0 98, Sobral sewer outfall, Maceió, Alagoas, Brazil, 9 º 40 ' 45 " S, 35 º 45 '01" W, intertidal, on bryozoans, coll. 24 December 2006 by M.D. Correia; UFAL 0 121, coll. 18 January 2007 by L.M. Vieira and M.D. Correia. UFAL 0 211, UFPE 0 75, UFPE 0 87, UFPE 101, Riacho Doce, Maceió, Alagoas, Brazil, 9 º 34 ' 42 " S, 35 º 39 ' 19 " W, intertidal, on algae, Sargassum spp., coll. 31 March 2007 by L.M. Vieira. UFAL 252, UFPE 0 64, UFPE 0 66, UFPE 0 69, UFPE 0 93, Pratagy (Sereia), Maceió, Alagoas, Brazil, 9 º 33 ' 55 " S, 35 º 38 ' 40 " W, intertidal, on algae, Sargassum spp., coll. 0 7 September 2007 by A.G.A. Borba Jr. UFPE 103, Jatiúca, Maceió, Alagoas, Brazil, 9 º 39 ' 10 " S, 35 º 41 ' 40 " W, intertidal, on algae, Sargassum spp., coll. 0 9 September 2007 by L.M. Vieira; UFPE 105, coll. 13 August 2007 by L.M. Vieira; UFPE 111, coll. 0 9 September 2003 by L.M. Vieira. Additional comparative material. NHMUK 1899.7.1.562– 3, NHMUK 1899.7. 1.565, G. Busk collection, John Adams Banks [Abrolhos], Bahia, Brazil, on algae, coll. H.M.S. ‘ Herald’; NHMUK 1888.4. 16.22, H.N. Ridley collection, Pernambuco, Brazil, on algae. Description. Colony of uniserial chains of autozooids, creeping, delicate, white, from which erect tubular portions arise. Basal portion creeping, slender and slightly punctate. Tubular portion arising from dilations of basal region; erect stems almost ringed, narrowed proximally and curved distally, about 0.494–0.865 mm (0.659 ± 0.098) long and 0.049–0.074 mm (0.059 ± 0.006) wide; frontal membrane curved proximally and truncate distally, occupying one side of the scoop-shaped head region at the distal third of stalk, about 0.185–0.241 mm (0.212 ± 0.018) long. Basal surface of membranous area with several small pseudopores. Zoeciules absent. Ovisacs with reddish embryos at the distal end of zooid, distal to orifice, placed on dorsal surface of the scoop-shaped area. Remarks. Species of Aetea are often found on the surface of shells, algae and other colonial invertebrates, such as bryozoans and hydroids. Species of the genus are distinguished by the size of the raised stalk region, size and shape of the distal ‘head’ region, zoecial ornamentation (punctate, annulated, corrugated or wrinkled), and embryo color. At least two species, Aetea anguina (Linnaeus, 1758) and Aetea sica (Couch, 1844), had been widely reported in shallow waters, including Brazil (Vieira et al. 2008). They were previously characterized by an often-flexed stalk with annulations, and a perforated spatulate distal head, which is parallel to the substratum when the stalk is flexed. Comparison between specimens from Brazil and other specimens deposited at the NHMUK and USNM revealed, however, that several species may be involved under the names A. anguina and A. sica (e.g. Busk 1852 a; Landsborough 1852; Marcus 1937; Osburn, 1940; Hayward & Ryland 1998;). These species are distinguished by the zooid length and head region width, and by the shape and pseudopores of the head, in addition to the shape and density of annulations, if present, in stalks. Specimens from Gibraltar identified by Landsborough (1852) (NHMUK 1899.7. 1.542, G. Busk Collection) and specimens from British Isles (Hayward & Ryland 1998) resemble those from NE Brazil in having annulated stalks and a punctate distal portion, but are distinguished by their size, shape of the head and diameter of stalks. Hayward & Ryland (1998) described golden yellow embryos in both A. anguina and A. sica, further distinguishing them from the specimens from Alagoas with their reddish embryos. Specimens from Europe, as illustrated in Hayward & Ryland (1998: fig. 16; British Isles) and De Blauwe (2009: figs. 125–127; Belgium) also show a greater curvature of the stem region near the head, and presence of annulations further into the head region. Recently, Winston & Hayward (2012) described A. arcuata from the northeast coast of the USA, with a finely annulated stalk and pinkish embryos, which we believe may be conspecific with specimens from Brazil examined in this study. In Brazil, A. anguina was previously recorded from Bahia (NE), Pernambuco (NE), Espírito Santo (SE), Rio de Janeiro (SE), São Paulo (SE), and Paraná (S) states (Vieira et al. 2008; Almeida et al. 2015 b), although with morphological differences. Specimens recorded as Aetea recta Hincks, 1862 from Pernambuco (Kirkpatrick 1890) are similar to specimens here assigned to A. arcuata. Specimens from Bahia (Almeida et al. 2015 b) may also belong to A. arcuata. Specimens of A. anguina from São Paulo (Marcus 1937; Migotto et al. 2011), however, have a shorter membranous area and wider stalk than colonies figured here, and may belong to an undescribed species rather than to either A. anguina or A. arcuata. Specimens from Espírito Santo, Rio de Janeiro and Paraná (see Vieira et al. 2008) require reexamination; they may belong to distinct species. Distribution. Aetea arcuata is known from the Western Atlantic, from the northeast to the south coast of USA, including Florida, and from NE Brazil. In NE Brazil it is known from Pernambuco, Alagoas, and Bahia (Abrolhos; G. Busk collection).Published as part of Vieira, Leandro M., Almeida, Ana C. S. & Winston, Judith E., 2016, Taxonomy of intertidal cheilostome Bryozoa of Maceió, northeastern Brazil. Part 1: Suborders Inovicellina, Malacostegina and Thalamoporellina, pp. 59-83 in Zootaxa 4097 (1) on pages 61-62, DOI: 10.11646/zootaxa.4097.1.3, http://zenodo.org/record/27101
<i>No se sabe</i>: entrevista a Laura Sombra del Río
No full textEntrevista a la profesora de Matemática Laura Sombra del Río, integrante del Instituto de Metodología Alternativa para la Enseñanza de la Ciencia (IMApEC). Se especializa en tecnología informática aplicada a la educación, especialmente de las ciencias duras como la matemática.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de Laura Sombra del Río presentes en el repositorio.Facultad de Ingenierí
Particles with Tunable Porosity and Morphology by Controlling Interfacial Instability in Block Copolymer Emulsions
No full textA series of porous block copolymer
(BCP) particles with controllable
morphology and pore sizes was fabricated by tuning the interfacial
behavior of BCP droplets in oil-in-water emulsions. A synergistic
adsorption of polystyrene-b-poly(4-vinylpyridine)
(PS-b-P4VP) BCPs and sodium dodecyl sulfate (SDS)
to the surface of the emulsion droplet induced a dramatic decrease
in the interfacial tension and generated interfacial instability at
the particle surface. In particular, the SDS concentration and the
P4VP volume fraction of PS-b-P4VP were key parameters
in determining the degree of interfacial instability, leading to different
types of particles including micelles, capsules, closed-porosity particles,
and open-porosity particles with tunable pore sizes ranging from 10
to 500 nm. The particles with open-porosity could be used as pH-responsive,
high capacity delivery systems where the uptake and release of multiple
dyes could be achieved
MICROPROPAGATION of THE KIWI FRUIT 'HAYWARD'
No full textO presente trabalho teve como objetivo desenvolver um protocolo para a obtenção de mudas de kiwi (Actinidia chinensis Planch), cv. Hayward, por meio do cultivo in vitro de cotilédones. Utilizou-se o meio de MURASHIGE & SKOOG (1962) -- MS, suplementado com dois tipos de auxina (AIA e AIB) e uma citocinina (BAP). Foram verificados os efeitos de três doses de auxinas (0,125; 0,250 e 0,375 mg.L-1), combinadas com três doses de citocinina (0,5; 1,0 e 1,5 mg.L-1) na capacidade morfogênica dos explantes. Procedeu-se o estudo histológico dos órgãos das plântulas obtidas in vitro, e verificou-se, também, a capacidade de aclimatação das mudas ex vitro. A menor dose de AIB (0,125 mg.L-1), independentemente das doses de BAP, foi a mais eficaz na morfogênese dos explantes. Não foram verificadas alterações histológicas e anatômicas das plântulas obtidas in vitro. Aos três meses após o cultivo ex vitro dos explantes, verificou-se a sobrevivência de 88% das plantas transplantadas em condições de campo.The aim of this paper was to develop a protocol for plantlets production in kiwi fruit (Actinidia chinensis Planch) Hayward through in vitro cotyledons cultivation. For this purpose the Murashige & Skoog (1962) medium was supplemented with two types of auxin (IAA and IBA) and also with a cytokinin (BAP). Effects over the morphogenic capacity of the explants were tested using three auxin (0.125; 0.250 and 0.375 mg.L-1) and cytokinin (0.5; 1.0 and 1.5 mg.L-1) concentrations. Studies in the obtained plantlets histology and acclimatization capacity were proceeded. It could be concluded that IBA at the lowest concentration (0.125 mg. L-1) was the most effective in explants morphogenesis, regardless of the BAP concentration. In vitro obtained plantlets did not present any anatomical nor histological alterations. Three months after transplanting it was observed that 88% of the plantlets had survived at field conditions.UNESP FCAV Dept Biologia Aplicada à AgropecuáriaUNESP FCAV Dept Biologia Aplicada à Agropecuári
Secciones de dispersión y absorción de Hayward con quintaesencia
No full textIn this contribution, we study the scattering and absorption sections of the Hayward black hole surrounded by quintessence. Itshows how the behavior of the classical and semi-classical scattering cross sections is modified by varying the value of the normalization factor dependent on the quintessence density. In addition, the absorption section is studied with the sinc approximation inthe eikonal limit. In both cases, the quintessence state parameter is considered in the particular cases ω = −2/3 and ω = −4/9.En esta contribución, estudiamos las secciones de dispersión y absorción del agujero negro de Hayward rodeado por quintaesencia. Se muestra cómo se modifica el comportamiento de las secciones transversales de dispersión clásica y semiclásica al
variar el valor de factor de normalización dependiente de la densidad de quintaescencia. Además, se estudia la sección de absorción con la aproximación sinc en el límite eikonal. En ambos casos se considera el parámetro de estado de quintaesencia en los casos
particulares ω = −2/3 y ω = −4/9
Una carta de Navarro Tomás antes del bombardeo de Barcelona. El legado hemerográfico y epistolar de Hayward Keniston
No full textEn este trabajo comentamos la biografía del hispanista Hayward Keniston, conocido sobre todo por su obra The Syntax of Castilian Prose pero autor de un relevante grupo de investigaciones sobre la lengua y la literatura españolas. Se expone el contacto de Keniston con otros hispanistas, así como dos documentos epistolares inéditos ligados a él que ayudan a reconstruir su biografía en el panorama intelectual de la hispanística estadounidense en torno al medio siglo. Se editan una carta de Ramón Menéndez Pidal y otra de Tomás Navarro Tomás.In this paper, we comment on the biography of the Hispanist Hayward Keniston, best known for his work The Syntax of Castilian Prose, but also the author of an important body of research on the Spanish language and literature. Keniston’s contact with other Hispanist are discussed, as well as two unpublished epistolary documents related to him that help to reconstruct his biography and the intellectual panorama of American Hispanic Studies. A letter by Ramón Menéndez Pidal and another by Tomás Navarro Tomás are published.Ministerio de Ciencia e Innovación PID2020-113146GB-I0
Stanwyck, Crawford et Hayward : femmes puissantes du gothique féminin tardif (1948-1962)
No full textCet article se propose d’examiner de quelle manière la persona et le jeu de certaines actrices modifient les attendus du film gothique féminin à travers quatre exemples significatifs : Barbara Stanwyck dans Sorry Wrong Number (Anatol Litvak, 1948), Joan Crawford dans Sudden Fear (David Miller, 1952) et Female on the Beach (Joseph Pevney, 1955) et Susan Hayward dans I Thank a Fool (Robert Stevens, 1962). Même si ces films présentent des intrigues qui convoquent les grands succès du début des années 1940 dans ce registre, Stanwyck, Crawford et Hayward ont l’assurance et la séduction des « femmes fatales » du film noir, alors que leurs personnages exercent souvent une autorité financière, juridique et sentimentale sur des époux ou amants subjugués. Elles ne sont absolument plus des ingénues, mais se rapprochent des « superwomen » définies par Haskell, capables de s’approprier certaines caractéristiques traditionnellement considérées comme masculines, et altèrent donc les modèles genrés habituellement à l’œuvre dans le film gothique féminin.This article aims to examine how the persona and performance of some actresses modify the the female gothic through four significant examples : Barbara Stanwyck in Sorry Wrong Number (Anatol Litvak, 1948), Joan Crawford in Sudden Fear ( David Miller, 1952) and Female on the Beach (Joseph Pevney, 1955) and Susan Hayward in I Thank a Fool (Robert Stevens, 1962). Even if these films present plots that recall the great successes of the early 1940s in this register, Stanwyck, Crawford and Hayward have the assurance and seduction of the “femmes fatales” of film noir, while their characters often exercise financial, legal and sentimental authority on subjugated husbands or lovers. They are absolutely no longer ingénues, but are closer to the “superwomen” defined by Haskell, capable of appropriating certain characteristics traditionally considered as masculine and therefore alter the gendered models usually at work in the female gothic
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