Multiple dinosaur egg-shell occurrence in an Upper Cretaceous nesting site from Patagonia

The discovery of hundreds of megaloolithid-type egg-clutches (some including embryos of an indeterminate species of titanosaur sauropods) in several stratigraphical levels of the Late Cretaceous nesting site of Auca Mahuevo (Chiappe et al., 2005) unveiled important aspects of the reproductive behavior of sauropod dinosaurs and stimulated further work at other Patagonian dinosaur egg sites. In November of 2003, a join expedition of the National University of Comahue (Neuquén), the Museo Carmen Funes (Plaza Huincul) and the Museo de Lamarque (Lamarque) conducted fieldwork in several Late Cretaceous localities of Bajo Santa Rosa (center-north Río Negro Province, Argentina) bearing the remains of dinosaur eggs and other terrestrial vertebrates (figure 1). The main focus of this expedition was to assess the diversity of dinosaur eggs, to fine-tune the stratigraphy of the egg-bearing layers, and to document the spatial distribution of the egg-clutches. The overall results of this research were reported elsewhere (Salgado et al., 2007). In this contribution, we make focus in one of the fossil localities worked, Berthe IV, where the association of egg clutches likely belonging to different dinosaur species was detected (figure 1.2). Collected eggshells were observed with a binocular loupe ‘‘Stemi SV6 Zeiss’’, at magnifications of x1.0 and x3.2 (for macrocharacters). Microcharacters were observed in transverse thin section using a polarizing microscope (‘‘Zeiss Axioplan’’) at magnifications of x0.4 and x10. The eggshells were photographed using this polarizing microscope equipped with a digital camera. Prior to analysis, the eggshells were submitted to a process of cleaning using ultrasound (see Salgado et al., 2007 for further methodological details).Fil: Coria, Rodolfo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia del Neuquen. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; ArgentinaFil: Salgado, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Museo de Geologia y Paleontologia; ArgentinaFil: Chiappe, Luis M.. Los Angeles County Museum of Natural History. Dinosaur Institute; Estados Unido

Ks1, an epithelial cell-specific gene, responds to early signals of head formation in Hydra

As a molecular marker for head specification in Hydra, we have cloned an epithelial cell-specific gene which responds to early signals of head formation. The gene, designated ks1, encodes a 217-amino acid protein lacking significant sequence similarity to any known protein. KS1 contains a N-terminal signal sequence and is rich in charged residues which are clustered in several domains. ks1 is expressed in tentacle-specific epithelial cells (battery cells) as well as in a small fraction of ectodermal epithelial cells in the gastric region subjacent to the tentacles. Treatment with the protein kinase C activator 12-O-tetradecanoylphorbol-13- acetate (TPA) causes a rapid increase in the level of ks1 mRNA in head-specific epithelial cells and also induces ectopic ks1 expression in cells of the gastric region. Sequence elements in the 5 ¢-flanking region of ks1 that are related to TPA-responsive elements may mediate the TPA inducibility of ks1 expression. The pattern of expression of ks1 suggests that a ligand-activated diacylglycerol second messenger system is involved in head-specific differentiation

Hydra tropomyosin TROP1 is expressed in head-specific epithelial cells and is a major component of the cytoskeletal structure that anchors nematocytes

A cDNA clone encoding a 253 amino acid tropomyosin was isolated from Hydra in a differential screen for headspecific genes. The Hydra tropomyosin gene, designated trop1, is a single copy gene, lacks introns and is strongly expressed in tentacle-specific epithelial cells. Analysis of protein synthesis in head and gastric tissue indicated a high rate of tropomyosin synthesis in head tissue. Immunolocalization of tropomyosin in tentacle tissue revealed a cushion-like tropomyosin-containing structure within battery cells at the base of nematocytes. The structure appears to form part of the cytoskeletal anchor for nematocytes. Tropomyosin cushions were also observed in epithelial cells along the body column, which contain mounted stenotele nematocytes

Tele-revista: representaciones, imágenes y libertad política en un informativo de la televisión pública suiza para la emigración española

Desde 1973 hasta 2003 la televisión pública suiza emitió el programa Telerevista una vez cada dos semanas, los fines de semana, y con una duración de quince minutos. Tele-revista era un programa en español dirigido a los emigrantes españoles en el país helvético que contenía reportajes de temas relacionados con la realidad de la comunidad española. En una primera parte abordaremos la imagen y la puesta en escena del poder institucional de la administración española en Suiza en el programa y de su evolución a lo largo del tiempo. En una segunda parte trataremos los esfuerzos del programa por formar a los espectadores en cuestiones de democracia y libertades en Suiza. Finalmente nos ocuparemos de la presencia cada vez mayor en la información cultural del programa de las particularidades y de las relaciones entre cultura popular y alta cultura.Between 1973 and 2003 Swiss television used to broadcast at the weekend the biweekly news magazine Tele-revista, which lasted 15 minutes. Tele-revista was sent in Spanish and addressed to Spanish migrants living in Switzerland. It contained reportages about the Spanish community’s reality. This paper focuses first on the image and the staging of the Spanish administration’s institutional power in Switzerland and its evolution in the course of time. Then it will consider the efforts to educate the audience in matters of democracy and liberties in Switzerland. Finally it will treat the increasing presence in the magazine’s cultural section of the characteristics and the relation between popular and high culture

Medios audiovisuales en la enseñanza universitaria de la historia. Análisis del documental : Hans Hutter : un suizo en la guerra civil española

Los medios audiovisuales pueden estar presentes en la enseñanza de la Historia a nivel universitario desde los primeros cursos. Esta es la apuesta del Seminario de Historia de Zúrich, que, con motivo de la implantación de la reforma de Bolonia, se ha propuesto integrarlos en una plataforma de e-learning pensada para esta primera fase de los estudios. Para ello se han rodado películas cortas que se muestran en la plataforma sobre los siguientes temas: qué es la Historia; cómo buscar bibliografía en una biblioteca; cómo presentar una ponencia; qué es una fuente; qué función social tienen los archivos y cómo se trabaja en ellos. Finalmente, se utiliza un documental (que se ofrece como complemento de este número de la revista) para conjugar el uso de entrevistas de historia oral, de películas de archivo y de fotografías.Since the first courses audiovisual media can be present in academical history education. This is the application of Zurich’s Institute of History, which due to the introduction of the Bologna process has intended to integrate them into an elearning platform preconceived for this first level of study. For this purpose short movies have been filmed, which are showed on the platform on the following subjects: What is history? How to find a bibliography in a library; How to give a presentation; What is a source? What are the archives’ social functions and how do we work with them? Finally, a documentary film (offered as a supplement to this review volume) is used in order to combine the use of oral history interviews, archive movies and pictures

Photo-detectors integrated with resonant tunneling diodes

We report on photo-detectors consisting of an optical waveguide that incorporates a resonant tunneling diode (RTD). Operating at wavelengths around 1.55 μm in the optical communications C band we achieve maximum sensitivities of around 0.29 A/W which is dependent on the bias voltage. This is due to the nature of RTD nonlinear current-voltage characteristic that has a negative differential resistance (NDR) region. The resonant tunneling diode photo-detector (RTD-PD) can be operated in either non-oscillating or oscillating regimes depending on the bias voltage quiescent point. The oscillating regime is apparent when the RTD-PD is biased in the NDR region giving rise to electrical gain and microwave self-sustained oscillations Taking advantage of the RTD’s NDR distinctive characteristics, we demonstrate efficient detection of gigahertz (GHz) modulated optical carriers and optical control of a RTD GHz oscillator. RTD-PD based devices can have applications in generation and optical control of GHz low-phase noise oscillators, clock recovery systems, and fiber optic enabled radio frequency communication systems.info:eu-repo/semantics/publishedVersio

External interaction management of VRML scenes for e-learning applications

This is an electronic version of the paper presenten at the International conference on International Workshop on Web3D Technologies in Learning, Education and Training (LET-Web3D 2004) held in Udine (Italy) on 2004This paper describes an innovative approach to solve some of the problems that arise when integrating virtual reality capabilities into e-learning environments. The VRML representation of a scene includes, along with its geometric description, a full specification of the student-scene interaction logic. This representation is rendered by a browser, which also orchestrates the interaction according to the logic. Such a mechanism implies reprogramming and/or replicating partly the logic when modifying the interaction scheme of a single scene for different students. It also prevents any external access to student’s actions or scene reactions, which is necessary for on-line evaluation or instruction. We propose to expand the standard interaction mechanism of VRML so that both the specification of the scene logic and the interaction flow are managed by an external and centralized entity following a clientserver approach, hence solving the identified problems, while additionally increasing design efficiency and content protection.This work has been partly supported by the Plan Nacional de Ciencia y Tecnología of the Spanish Government under project TIC2001-306

Determination of Thermophysical Properties of the Protic Ionic Liquid EIM NO₃, Pure and Doped with Lithium Nitrate Salt

[Abstract] In this work, viscosity, density and electrical conductivity of the ionic liquid, Ethylimidazolium Nitrate pure and doped with lithium nitrate salt were determined in order to check the properties’ improvement of the ionic liquid with the salt addition to consider these mixtures as potential electrolytes. Viscosity decreases exponentially as temperature increases, and increases with salt content, as expected. Density values decrease linearly as temperature increases and also increases with salt content. From electrical studies, an increase of conductivity with temperature and a decrease with salt concentration were observed. No significant differences between pure and doped sample were observed on Walden plots.This work was supported by Spanish Ministry of Economy and Competitiveness and FEDER Program through the projects MAT2014-57943-C3-1-P, MAT2014-57943-C3-3-P, MAT2017-89239-C2-1-P, as well as by Xunta de Galicia through GRC ED431C 2020/10 project and the Galician Network of Ionic Liquids (ReGaLIs) ED431D 2017/06. P. Vallet and J. J. Parajó thank funding support of FPI Program from Spanish Ministry of Science, Education and Universities and I2C postdoctoral Program of Xunta de Galicia, respectivelyXunta de Galicia; ED431C 2020/10Xunta de Galicia; ED431D 2017/0

Fast Mode Decision on H.264/AVC Baseline Profile for real-time performance

In this paper a new fast mode decision (FMD) algorithm is proposed for the recent H.264/AVC video coding standard, aiming to reduce its computational load without loosing coding efficiency. This algorithm identifies redundancy and selects the minimum sub-set of modes for each macroblock (MB) required to provide high rate-distortion (RD) efficiency. It is based on a fast analysis of the histogram of the difference image between frames which classifies the areas of each frame as active or non-active by means of an adaptive thresholding technique. More coding effort is devoted to active areas with the selection of a large sub-set of Modes, as these areas are expected to be the most relevant in terms of RD cost. Results show reduction values around 35–65% of motion estimation (ME) time, preserving the RD cost for the Baseline Profile, by using P-Slices and without needing B-Slices. Moreover, the strategy works as an intelligent tool for real-time applications with constrained number of operations per frame: it wisely uses the given operational resources distributing them among those MBs that need it