50,849 research outputs found
Influence of salicylic acid on phytochelatin synthesis in Zea mays during Cd stress
No full textAbstract: Presoaking maize (Zea mays) seeds in salicylic acid (SA) reduces damage caused by cadmium. In the present work the possible
role of phytochelatins (PCs) in SA-mediated protection against Cd toxicity was investigated. Seeds were presoaked in 0.5 mM SA, and
seedlings were grown in hydroponic solution containing 0, 0.01, 0.015, or 0.025 mM Cd. Treatment with Cd increased the PC levels in
maize roots, but only slight changes were observed in the leaves. Long-term exposure to Cd decreased the phytochelatin synthase (PCS)
activity in the roots and led to an increase in PCS and glutathione reductase (GR) activities in maize leaves. Although presoaking seeds
in SA solution before exposure to Cd may reduce the level of heavy metal injury and has an effect on the composition of individual PCs,
this protection is not directly connected with the altered regulation of PCs
Filosofía de la historia Americana
No full textLos aportes de Leopoldo Zea a la reflexión sobre América y el mundo no deben restringirse al ambito filosófico propiamente dicho, ya que logró configurar una serie de temas y problemas nodales que a su vez sometió a un amplio debate intelectual. No le bastó con recuperar lo que le significó para América Latina la apertura de la corriente de la historia de las ideas y el reconocimiento de la dignidad de la filosofía latinoamericana, sino que también atendió al carácter constitutivo, estructurador, que tuvo este quehacer, cuyo reconocimiento culmina en obras como la Filosofía de la historia americana (1978). Para Zea no se trataba sólo de descubrir un tema, definir un problema o aplicar una metodología para su análisis: se trataba de fundarlo como tal, de enlazarlo como una tradición de pensamiento y de establecer un diálogo con los maestros que lo precedieron y los contemporáneos que lo acompañaron.Libro
A List of Zea Books, published by University of Nebraska-Lincoln Libraries
No full text94 published titles (2005-2020), plus 1 forthcoming this fall.
Zea Books are produced by the Office of Scholarly Communications, and published by the University of Nebraska-Lincoln Libraries.
With links to online pdf editions and Lulu.com print-on-demand online storefront.
Zea Books are online at https://digitalcommons.unl.edu/zeabook/
Print-on-demand editions are available @ http://www.lulu.com/spotlight/unlli
Los orígenes del latinoamericanismo de Leopoldo Zea
No full textEn esta intervención se habla sobre la obra del joven Leopoldo Zea, a partir de una lectura de los artículos recopilados en “Leopoldo Zea: escritos de juventud 1933-1942” con el cual se pretendían buscar los orígenes del Zea que se conoció, quien era una figura mundial, un maestro reconocido. Se intenta entender cómo fue que empezó a ocuparse del tema de América Latina, en qué contexto, en qué circunstancia y cómo fue que llegó a ese tema
Dragmacidon alvarezae Zea & Pulido, 2016, n. sp.
No full textDragmacidon alvarezae n. sp. Fig. 1 B, 2 B, 3 B, 4; plate 1 figs. E–I, Tables 1–2 Pseudaxinella lunaecharta; Wiedenmayer 1977: 155, pl. 31 figs. 7–10; pl. 32 figs. 1–3, textfig. 156 (Bimini, Bahamas; Florida Keys) (in part; some specimens could be Dragmacidon reticulatum); Gómez López & Green 1984: 81, fig. 20 (Quintana Roo, Mexico); Pulitzer-Finali 1986: 102 (Bimini, Bahamas; Boca Chica and Boca de Yuma, Dominican Republic); Zea 1987: 195, fig. 70, pl 12 figs. 3–4 (Continental coast of Colombia; Old Providence Island); Gammill 1997: 5, photo 5 (Florida Keys; Bahamas; Caribbean); Gómez 2002: 73, fig. (Gulf of Mexico; Yucatán; Quintana Roo). Dragmacidon “ lunaecharta ”; Zea et al. 2014 (Bahamas; Florida Keys; continental coast of Colombia). [Non: Axinella (?) lunaecharta Ridley & Dendy, 1886: 481 (Cape Verde Islands); Ridley & Dendy, 1887: 186, pl. 37, figs. 1, 1a, 2 (= Dragmacidon lunaecharta, valid species from the eastern Atlantic, see Alvarez et al. 1998).] Pseudaxinella reticulata; Alvarez et al. 1998: 15, figs. 8, 9, table 8 [in part, apparently all specimens but USNM 32847 (Bermuda) and USNM 42787 (Gulf of Mexico); North Carolina, South Carolina and Georgia shelves; east coast of Florida; Gulf of Mexico; Belize; Nicaragua; Puerto Rico; US Virgin Islands; Curaçao, Tobago, Venezuela]. Dragmacidon reticulata; Díaz 2007: 47; Mora-Cristancho et al. 2007: 170, Table 1 (Santa Marta, Colombia, antifouling properties); Díaz & Zea 2008: 34 (Guajira, Colombia). Dragmacidon reticulatus; Valderrama & Zea 2013: 358 (Gulf of Urabá, Colombia; annotated list citing material from Zea 1987). Dragmacidon reticulatum; Zea et al. 2009 (Bahamas, Florida Keys); Rützler et al. 2014: 70 (Carrie Bow Cay, Belize). [Non: Dragmacidon reticulatum (Ridley & Dendy, 1886) (original under Axinella; a valid species).] Type material and type locality. Continental coast of Colombia, Santa Marta, Holotype : INV-POR 0 525, Bahía de Santa Marta, Morro, SW side (11 ° 14 ’ 57.77 ” N, 74 ° 13 ’ 48.66 ” W), 15–23 m, coll. Sven Zea, 2 September 1997 (voucher for Castellanos et al. 2003, as Pseudaxinella reticulata). Paratypes (coll. Sven Zea): INV-POR 0 330, Ensenada Granate, canal de la Aguja (11 ° 18 ’ 28.40 ” N, 74 ° 11 ’ 31.93 " W), 6 m, 23 June 1981 (described by Zea, 1987 as Pseudaxinella lunaecharta); ICN-MHN(Po) 0 140, Bahía de Nenguange, in front of Playa Brava (11 ° 19 ’ 43.96 ” W, 74 ° 5 ’ 55.24 ” W), 12 m, 20 April 1982 (described by Zea, 1987 as Pseudaxinella lunaecharta); INV-POR 1259, Bahía de Santa Marta, Morro, SW side (11 ° 14 ’ 57.77 ” N, 74 ° 13 ’ 48.66 ” W), 20 m, 9 July 1993. Additional material. Bahamas: voucher 189 (tissue slide, 10 m, 19 June 2004), voucher 286 (12 m, 26 June 200,), Stirrup Cays, N Berry Islands (25 ° 49 ’ 39.2 ” N, 77 ° 53 ’ 497.9 ” W), coll. Sven Zea. USA, East side of Florida: USNM 30384 (fragment INV-POR 1261), Florida Keys, Looe Key, west patch reef, coll. S. Pomponi, 14 June 1984 (originally identified as Pseudaxinella lunaecharta by K. Rützler and S. Pomponi, 1994). USA, Florida west coast, Gulf of Mexico: USNM 39859 (fragment INV-POR 1262), Florida west coast, Sta 0 7 (26 ° 16 ’ 49 ” N, 82 ° 44 ’01” W), 30.4 m, 19 July 1981 (originally identified as Pseudaxinella rosacea). Southwestern Caribbean, Old Providence Island : INV-POR 0 331, Blue Hole (13 ° 24 ’ 16.80 ” N, 81 ° 23 ’ 37.11 ” W), 27 m, coll. Sven Zea, 8 December 1980 (material described by Zea 1987). Continental coast of Colombia, Gulf of Urabá : INV-POR 0 327, 328, Peñón Napú (08° 25 ’ 10 ” N, 77 °07’ 14 ” W), coll. INVEMAR Expedition, October 1977 (described by Zea 1987 as Pseudaxinella lunaecharta; listed by Valderrama & Zea 2013 as Dragmacidon reticulatu s); Cartagena: INV-POR 0 329, Banco Salmedina (10 ° 22 ’ 24.59 ” N, 75 ° 39 ’ 58.59 ” W), 24 m, coll. Sven Zea, 19 July 1980 (described by Zea 1980); ICN-MHN(Po) 0 139, Islas del Rosario, Isla Tesoro, north side (10 ° 14 ’ 3.93 ” N, 75 ° 44 ’ 25.22 ” W), 15 m, coll. Sven Zea, 1 February 1983 (described by Zea, 1987 as Pseudaxinella lunaecharta); Santa Marta: INV-POR 881, Bahía de Santa Marta, Morro, SW side (11 ° 14 ’ 57.77 ” N, 74 ° 13 ’ 48.66 ” W), 24 m, coll. Sven Zea & Marisol Santos-Acevedo, 18 November 2003 (voucher for Mora-Cristancho et al. 2007, as Dragmacidon reticulata). Guajira: INV-POR1097, 10 m, coll. INVEMAR-CORPOGUAJIRA Expedition on board R/V Ancón, station 215, Bahía Honda (12 ° 23 ’ 33 ” N, 71 ° 45 ’ 40 ” W), 30 March- 9 April 2005 (material described by Díaz 2007 as Dragmacidon reticulata). Description. Shape, color and consistency. Encrusting, massive, or erect with lobed, fan- or club-shaped projections; the latter sometimes divided; large specimens can be arborescent, with flattened branches thickened at the tips. Size from a few cm in height and thickness up to 25–30 cm or more in height when erect. At Santa Marta, continental coast of Colombia, it is always encrusting, up to 2–3 cm thick and up to 20–25 cm in maximum diameter. Surface smooth to slightly hispid, sometimes more so in elevated portions; oscules even or slightly elevated, scattered, or aligned on ridges or fanned projections, where these occur, 1–5 mm in diameter. Live color scarlet red to orange; interior orange; cream when preserved. Consistency toughly compressible; erect specimens more compressible and flexible. Abundant mucus is exuded upon handling. Skeleton. Vertically elongated reticulation of ascending and diverging plumose spicule tracts, 100–500 µm thick, up to 300 µm apart, interconnected every 175–1225 µm by thinner, 50–350 µm tracts. At the surface, ascending tracts end in non-projecting spicule brushes. Spicules are: (1) Styles, slightly curved, with smooth heads and acute to slightly telescopic ends, 170–390 µm by 4.5–28 µm. (2) Oxeas, slightly curved, usually slightly asymmetric, with pointed to slightly telescopic ends, 210–420 µm by 5–17.5 µm. Specimen measurements are given in Table 1. Distribution. Bahamas, Florida, Gulf of Mexico, Antilles, Central America, north coast of South America. Its presence in Bermuda and Brazil is possible, but needs to be confirmed. Ecology. It inhabits rocky littorals and reefs, from shallow to deep, generally exposed to light, but sometimes cryptic (Rützler et al. 2014). Depth range 1– 31 m. Etymology. Named in honor of Venezuelan spongologist Belinda Alvarez, now at Lund University, Sweden, for her contributions to systematics and taxonomy of sponges, especially of the order Halichondrida sensu lato. ……continued on the next page Remarks. Although D. reticulatum and D. alvarezae n. sp. share many characteristics such as both being encrusting, exudating mucus, having the same color, same spicule types, and overlapping size range of spicules and skeletal tracts, they can also be distinguished as different species from a combination of characteristics (Table 2). We confirmed these differences by detailed examination of co-occurring specimens from the Bahamas and from Santa Marta, Colombia (see also Plate 1). While D. reticulatum is predominantly encrusting and massive, D. alvarezae n. sp. can grow fan or club shaped projections, sometimes even becoming arborescent (excepting at Santa Marta, where both species are always thickly encrusting); erect specimens of D. alvarezae n. sp. can be more flexible and compressible than encrusting forms of both species. The surface of D. reticulatum is rugose, often with hispid projections, while D. alvarezae n. sp. has a more even and smoother surface, usually without or with fewer and lower hispid projections. The skeletal architecture is also distinctive. In D. reticulatum the ascending tracts are usually thicker, more widely spaced, and protrude above the surface to form the hispid projections, while in D. alvarezae n. sp. the reticulation is elongated vertically, more compact and uniform, and although at the surface there are dense bouquets of spicules, these do not project as much to form spines. Although spicule sizes overlap in the two species and oxeas always reach larger sizes than styles in both species, maximum sizes are always smaller in D. alvarezae n. sp. than in D. reticulatum (Tables 1 and 2, Fig. 4); in D. alvarezae only rarely a specimen may have a few spicules that surpass 400 µm in length (max measured 420), while in D. reticulatum many spicules within a specimen reach larger sizes (Fig. 4). Statistical comparison of spicule length (mean per specimen) in localities where there was available data for both species (Bahamas, Florida Keys, Gulf of Mexico, Santa Marta) confirmed that D. reticulatum styles and oxea are significantly larger (p<0.05) than those of D. alvarezae n. sp. (two-way ANOVA with factors being species, locality and species*locality).Published as part of Zea, Sven & Pulido, Alejandra, 2016, Taxonomy of the Caribbean sponge Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida), with the description of a new species, pp. 393-408 in Zootaxa 4114 (4) on pages 397-402, DOI: 10.11646/zootaxa.4114.4.2, http://zenodo.org/record/26396
Obras en verso y prosa de Francisco de Zea
No full texta f. de lám., retr. do aut.: "Litog. de J. Donon
Mode of inheritance and combining abilities for kernel row number, kernel number per row and grain yield in maize (Zea mays L.)
No full textBocanski J., Z. Sreckov, A. Nastasic, M. Ivanovic, I.Djalovic and M. Vukosavljev (2010): Mode of inheritance and combining abilities for kernel row number, kernel number per row and grain yield in maize (Zea mays L.) - Genetika, Vol 42, No. 1, 169- 176. Utilization of heterosis requires the study of combining abilities of potential parents. In view of this, the objective of this paper was to study combining abilities and determine the mode of inheritance and gene effects for the main agronomic character, grain yield, and its components, kernel row number and kernel number per row. Six inbred lines Were used in the study, three of which originated in the U.S., while the other three were developed at the Institute of Field and Vegetable Crops in Novi Sad. Kernel row number was inherited by superdominance, partial dominance, complete dominance and intermediacy. The mode of inheritance of kernel number per row and grain yield was superdominance. Additive gene action had the greatest influence on the expression of kernel row number, while the other two traits were influenced the most by nonalditive gene
Leopoldo Zea polemista
No full textLeopoldo Zea Aguilar developed his intellectual work nurtured by discussion and the contraposition of ideas. Therefore, 100 years after his birth, the inner workings of his circumstances may be viewed by paying attention to the debates in which he was a protagonist. His anti-Eurocentric and anti-Manicheist arguments, encompassing the values of socialism, and even the systematization of his interdisciplinary methodological approach, are products of the controversies in which he became engaged.Leopoldo Zea Aguilar desarrolló su quehacer intelectual al calor de la discusión y confrontación de ideas. Por ello, a cien años de su nacimiento, puede radiografiarse su actualidad atendiendo los debates en los que fue protagonista. Producto de las polémicas que entabló son sus argumentos antieurocentristas, antimaniqueístas y comprensivos de los valores del socialismo, e incluso la sistematización de su enfoque metodológico interdisciplinario
Intelectuales: entre el compromiso social y el conocimiento estricto. Ética, política y epistemología en Leopoldo Zea
No full textIs the dilemma between social commitment and commitment to knowledge inevitable for intellectuals? This paper, based on the thought of Leopoldo Zea, and through a hermeneutical, analytical-conceptual, critical-evaluative, and theoretical-constructive method, argues that these commitments are not only compatible, but also implicate each other. To argue this point, it elaborates a conceptualization of the figure of intellectuals and his social commitment, according to which it is proper to them to articulate his theoretical activity to ethical and political transtheoretical activity, while preserving the autonomy of theoretical activity and seeking universal knowledge. The article has a double importance: on the one hand, it makes a reformulation of the valid ideas of Zea in this regard; on the other hand, it offers a scheme with a claim of general validity regarding a now as ever urgent social problem: intellectuals’ social commitment and his commitment to knowledge.¿Es inevitable para el intelectual la disyuntiva entre el compromiso social y el compromiso con el conocimiento? Este artículo, a partir del pensamiento de Leopoldo Zea, y a través de un método hermenéutico, analítico-conceptual, crítico-evaluativo y teórico-constructivo, sostiene que esos compromisos no solo son compatibles, sino que se implican el uno al otro. Para argumentar este punto, elabora una conceptualización de la figura del intelectual y de su compromiso social, de acuerdo con la cual lo propio del intelectual consiste en articular su actividad teórica a la actividad transteórica ética y política, a la vez que en preservar la autonomía de la actividad teórica y buscar un conocimiento universal. El artículo tiene una importancia doble: por una parte, efectúa una reformulación de las ideas vigentes de Zea al respecto; por otra parte, ofrece un esquema con pretensión de validez general respecto a un problema social apremiante hoy como ayer: el compromiso social del intelectual y su compromiso con el conocimiento
P\u27UNCHAW: una opética de la luz Cusqueña por Víctor Zea
No full textEn su reciente primer fotolibro, coeditado por Impresiones Choqechaka y KWY Ediciones, el fotógrafo Víctor Zea hace alusión a los mitosancestrales de la ciudad del Cusco a través del P’unchaw, que en quechua significa día.
En un espacio urbano actualmente muy cosmopolita, Zea aborda la observación del sol, la luz y la sombra que terminan pormaterializarse en ‘oro’, elemento de admiración para los Incas, el cual representaba a su dios más importante: el Sol
- …
