Search results for "amer"

Molecular heterogeneity of the hemocyanin isolated from the king crabParalithodes camtschaticae

2000

Native Paralithodes camtschaticae hemocyanin is found as a mixture of dodecamers (24S; 80%) and hexamers (16S; 20%). Removal of Ca2+ ions by dialysis against EDTA-containing buffer solution at neutral pH induces complete dissociation of the 24S form into the 16S form. Under these conditions, a further increase in pH to 9.2 produces complete dissociation of the hexamers into monomers (5S). In both cases, the dissociation process is reversible. The dodecamer (24S) is composed of two different hexamers which can be discriminated only by ion-exchange chromatography in the presence of Ca2+ ions. At alkaline pH and in the presence of EDTA, two major monomeric fractions can be separated by ion-exc…

Maternal Oct-4 is a potential key regulator of the developmental competence of mouse oocytes

2008

Abstract Background The maternal contribution of transcripts and proteins supplied to the zygote is crucial for the progression from a gametic to an embryonic control of preimplantation development. Here we compared the transcriptional profiles of two types of mouse MII oocytes, one which is developmentally competent (MIISN oocyte), the other that ceases development at the 2-cell stage (MIINSN oocyte), with the aim of identifying genes and gene expression networks whose misregulated expression would contribute to a reduced developmental competence. Results We report that: 1) the transcription factor Oct-4 is absent in MIINSN oocytes, accounting for 2) the down-regulation of Stella, a matern…

Nuevos actores de la no violencia

2001

Trails and Vestiges in the Stories and Travels of Eduardo L. Holmberg venezolano

2010

Este trabajo pretende estudiar la narrativa breve de Eduardo Holmberg, la manera cómo el escritor argentino traza, mediante acotaciones metaliterarias sobre los procesos constructivos del relato, fantasías científi cas y juguetes policiales desde una conciencia fi ccional que asume el estatuto literario como artifi cio y simulación. No sólo en este pliegue metafi ccional se funda el orden fantástico de las fábulas de este escritor, pues de una u otra manera, ese orden se nutre de los juegos alrededor del paradigma de la representación, del poder del simulacro, la pérdida del control narrativo y la posibilidad de una refl exión sobre el límite de la ficción. This paper is an analysis of the …

C'era una volta la cinefilia. C'era una volta...a Hollywood di Quentin Tarantino

2019

Institutions, crises, and political confidence in seven contemporary democracies. An elite-mass analysis

2017

There is ample consensus in the literature that institutional confidence by the public is needed in democracies and at the same time elites, particularly political elites, need to share this confidence in their guidance of state institutions, if political stability in established democracies and the consolidation of new democracies are desired. The research takes the form of a quantitative analysis based on the World Values Surveys and the elite surveys (parliamentarians) conducted in 2006 (before the financial crisis) and in 2012–2013 (post the crisis when apparently, the worst of the economic crunch had lessened up) in the 7 countries selected. We explore what lies at the base of politica…

Cytotoxicity and modes of action of five Cameroonian medicinal plants against multi-factorial drug resistance of tumor cells

2013

Abstract Ethnopharmacological relevance Beilschmiedia acuta Kosterm, Clausena anisata (Willd) Hook, Fagara tessmannii Engl., Newbouldia laevis Seem., and Polyscias fulva (Hiern) Harms. are medicinal plants used in Cameroonian traditional medicine in the treatment of various types of cancers. The present study aims at investigating 11 methanolic extracts from the above Cameroonian medicinal plants on a panel of human cancer cell lines, including various drug-resistant phenotypes. Possible modes of action were analyzed for two extracts from Beilschmiedia acuta and Polyscia fulva and alpha-hederin, the representative constituent of Polyscia fulva. Materials and methods Cytotoxicity was determi…

American cockroach control assays in the municipal sewerage system of Valencia (Spain)

2013

ABSTRACT Several insecticides (including different active substances and formulations) were applied to sewer shafts to control Periplaneta americana (LINNAEUS, 1758) populations in Valencia (eastern Spain). Results show that the best products for cockroach control were the paints (with and without insecticide), which provided an optimal reduction of P. americana populations for up to three months (P < 0.001). Therefore, it is important to note that the reduction of cockroach populations as well as the persistence of the insecticide effect in sewers was similar in both types of paints. A product combining two pyrethroids (Tetramethrin and Alfacipermetrin) and piperonyl butoxide also gave …

Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models

2016

Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares) in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fis…

La universidad colonial hispanoamericana (1538-1810) : bibliografía crítica, metodología y estado de la cuestión. El Río de la Plata

1994

Ponencia en las Actas de las VI Jornadas sobre la presencia universitaria española en América. Alcalá de Henares, 26 y 27 de Noviembre de 1992.