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Search Results: 1 - 10 of 189979 matches for " Pall G "
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Isotope research before Isotopy: George Hevesy's early radioactivity research in the Hungarian context
Palló,Gábor;
Dynamis , 2009, DOI: 10.4321/S0211-95362009000100008
Abstract: this paper presents a framework for the study of george hevesy's research in the 1910s by distinguishing two styles of radioactivity research: the analytical (as practices in manchester and vienna in some extent) and the natural historical styles (as practiced in hungary). georg hevesy's approach combined the two types. indeed, by studying hevesy's research in context, i show that the earliest applications of isotopes were born in parallel with the establishment of the isotope theory of matter.
Intensivmedizinische Therapie der instabilen Herzinsuffizienz
P?lzl G,Pall G
Journal für Kardiologie , 2003,
Abstract: Das Syndrom der instabilen Herzinsuffizienz ist eine komplexe und hochmaligne Erkrankung, die eine rasche und zielgerichtete Intervention erfordert. Mit der Erweiterung des therapeutischen Spektrums hat sich das Management der Erkrankung in den letzten Jahren ge ndert. Die frühzeitige Stratifizierung in akute Herzinsuffizienz und akut dekompensierte, chronische Herzinsuffizienz soll die Einleitung wichtiger diagnostischer und therapeutischer Schritte erleichtern und beschleunigen und die frühzeitige Festlegung eines konkreten Therapiezieles erm glichen. Voraussetzung für den differenzierten Einsatz der medikament sen Therapie ist das pathophysiologische Verst ndnis für h modynamische Ver nderungen. Eine Reduktion der hohen Mortalit tsrate beim kardiogenen Schock infolge eines akuten Myokardinfarkts ist durch rasche interventionelle Revaskularisation und Implantation einer intraaortalen Ballonpumpe m glich. Nach initialer Stabilisierung ist daher die ehestm gliche Transferierung betroffener Patienten an ein entsprechendes Zentrum sinnvoll.
Noncoding RNA Mediated Traffic of Foreign mRNA into Chloroplasts Reveals a Novel Signaling Mechanism in Plants
Gustavo Gómez,Vicente Pallás
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0012269
Abstract: Communication between chloroplasts and the nucleus is one of the milestones of the evolution of plants on earth. Proteins encoded by ancestral chloroplast-endogenous genes were transferred to the nucleus during the endosymbiotic evolution and originated this communication, which is mainly dependent on specific transit-peptides. However, the identification of nuclear-encoded proteins targeted to the chloroplast lacking these canonical signals suggests the existence of an alternative cellular pathway tuning this metabolic crosstalk. Non-coding RNAS (NcRNAs) are increasingly recognized as regulators of gene expression as they play roles previously believed to correspond to proteins. Avsunviroidae family viroids are the only noncoding functional RNAs that have been reported to traffic inside the chloroplasts. Elucidating mechanisms used by these pathogens to enter this organelle will unearth novel transport pathways in plant cells. Here we show that a viroid-derived NcRNA acting as a 5′UTR-end mediates the functional import of Green Fluorescent Protein (GFP) mRNA into chloroplast. This claim is supported by the observation at confocal microscopy of a selective accumulation of GFP in the chloroplast of the leaves expressing the chimeric vd-5′UTR/GFP and by the detection of the GFP mRNA in chloroplasts isolated from cells expressing this construct. These results support the existence of an alternative signaling mechanism in plants between the host cell and chloroplasts, where an ncRNA functions as a key regulatory molecule to control the accumulation of nuclear-encoded proteins in this organelle. In addition, our findings provide a conceptual framework to develop new biotechnological tools in systems using plant chloroplast as bioreactors. Finally, viroids of the family Avsunviroidae have probably evolved to subvert this signaling mechanism to regulate their differential traffic into the chloroplast of infected cells.
Pachyonychia congenita-like nail changes treated successfully with a combination of vitamins A and E: A case report
Mahajan B,Pall A,Garg G,Gupta R
Indian Journal of Dermatology, Venereology and Leprology , 2003,
Abstract: A 20-year-old man presented with thickening, subungual hyperkeratosis and discoloration of all the nails of both hands and both great toes since birth. No other ectodermal abnormalities were found. Treatment with vitamins A and E in high doses along with a moisturizing ointment topically for one year resulted in complete resolution of all nail abnormalities.
Photometric Variability of the Disk Integrated Infrared Emission of the Earth
I. Gómez-Leal,E. Pallé,F. Selsis
Physics , 2012, DOI: 10.1088/0004-637X/752/1/28
Abstract: We present an analysis of the global-integrated mid-infrared emission flux of the Earth based on data derived from satellite measurements. We have studied the photometric annual, seasonal, and rotational variability of the thermal emission of the Earth to determine which properties can be inferred from the point-like signal. We find that the analysis of the time series allows us to determine the 24 hr rotational period of the planet for most observing geometries, due to large warm and cold areas, identified with geographic features, which appear consecutively in the observer's planetary view. However, the effects of global-scale meteorology can effectively mask the rotation for several days at a time. We also find that orbital time series exhibit a seasonal modulation, whose amplitude depends strongly on the latitude of the observer but weakly on its ecliptic longitude. As no systematic difference of brightness temperature is found between the dayside and nightside, the phase variations of the Earth in the infrared range are negligible. Finally, we also conclude that the phase variation of a spatially unresolved Earth-Moon system is dominated by the lunar signal.
Communities in context: undefinitions, multiplicity and cultural difference
Cristina Pallí
Revista Interamericana de Psicología , 2003,
Abstract: Después de mostrar la pluralidad de nociones de comunidad que habitan la disciplina, se argumenta que la teorización sobre el concepto necesita reconocer e incluir la complejidad encontrada por lo/as psicólogo/as en sus prácticas comunitarias. Partiendo de una lógica representacional, y apoyándose en algunas condiciones empíricas, este artículo explora: a) la diversidad contextual de los significados del concepto de comunidad; b) el carácter diverso, a veces fracturado, de las comunidades, con límites variables y borrosos y con identidades cambiantes y controvertidas. C) el carácter relacional de las comunidades; construido a través de contextos históricos y prácticas locales, incluyendo las propias perspectivas de lo/as psicólogo/as comunitario/as. Se argumenta también que las relaciones dialógicas entre miembros y no miembros, y el capturar el significado de las situaciones cotidianas, son buenos modos de dar sentido de identidades y conceptos de comunidad, que pueden ser usados estratégicamente por la comunidad, a fin de producir cambios sociales
On the GJ 436 planetary system
G. Maciejewski,A. Niedzielski,G. Nowak,E. Pallé,B. Tingley,R. Errmann,R. Neuh?user
Physics , 2015,
Abstract: The GJ 436 system contains a transiting planet GJ 436 b which is a hot analogue of Neptune on an eccentric orbit. Recently, two additional transiting sub-Earth planets have been postulated in the literature. We observed three transits of GJ 436 b over the course of 3 years using two-meter class telescopes, each with a photometric precision better than one millimagnitude. We studied system dynamics based on the existence of the additional planets. We redetermined system parameters, which were in agreement with those found in the literature. We refined the orbital period of GJ 436 b and found no evidence of transit timing variations. The orbital motion of the GJ 436 c planet candidate was found to be significantly affected by the planet b with variations in transit times at a level of 20 minutes. As the orbital period of the GJ 436 d planet candidate remains unknown, our numerical experiments rule out orbits in low-order resonances with GJ 436 b. The GJ 436 system with the hot Neptune and additional two Earth-like planets, if confirmed, would be an important laboratory for studies of formation and evolution of planetary systems.
High-Throughput Sequencing, Characterization and Detection of New and Conserved Cucumber miRNAs
Germán Martínez,Javier Forment,Cesar Llave,Vicente Pallás,Gustavo Gómez
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019523
Abstract: Micro RNAS (miRNAs) are a class of endogenous small non coding RNAs involved in the post-transcriptional regulation of gene expression. In plants, a great number of conserved and specific miRNAs, mainly arising from model species, have been identified to date. However less is known about the diversity of these regulatory RNAs in vegetal species with agricultural and/or horticultural importance.
The centre-to-limb variations of solar Fraunhofer lines imprinted upon lunar eclipse spectra - Implications for exoplanet transit observations
Fei Yan,Robert A. E. Fosbury,Monika G. Petr-Gotzens,Gang Zhao,Enric Pallé
Physics , 2015, DOI: 10.1051/0004-6361/201425220
Abstract: The atmospheres of exoplanets are commonly studied by observing the transit of the planet passing in front of its parent star. The obscuration of part of the stellar disk during a transit will reveal aspects of its surface structure resulting from general centre-to-limb variations (CLVs). These become apparent when forming the ratio between the stellar light in and out of transit. These phenomena can be seen particularly clearly during the progress of a penumbral lunar eclipse, where the Earth transits the solar disk and masks different regions of the solar disk as the eclipse progresses. When inferring the properties of the planetary atmosphere, it is essential that this effect originating at the star is properly accounted for. Using the data observed from the 2014-April-15 lunar eclipse with the ESPaDOnS spectrograph mounted on the Canada France Hawaii Telescope (CFHT), we have obtained for the first time a time sequence of the penumbral spectra. These penumbral spectra enable us to study the centre-to-limb variations of solar Fraunhofer lines when the Earth is transiting Sun. The Na i and Ca ii absorption features reported from previous lunar eclipse observations are demonstrated to be CLV features, which dominate the corresponding line profiles and mask possible planetary signal. Detecting atmospheric species in exoplanets via transit spectroscopy must account for the CLV effect.
Using the Rossiter-McLaughlin effect to observe the transmission spectrum of Earth's atmosphere
Fei Yan,Robert A. E. Fosbury,Monika G. Petr-Gotzens,Enric Pallé,Gang Zhao
Physics , 2015, DOI: 10.1088/2041-8205/806/2/L23
Abstract: Due to stellar rotation, the observed radial velocity of a star varies during the transit of a planet across its surface, a phenomenon known as the Rossiter-McLaughlin (RM) effect. The amplitude of the RM effect is related to the radius of the planet which, because of differential absorption in the planetary atmosphere, depends on wavelength. Therefore, the wavelength-dependent RM effect can be used to probe the planetary atmosphere. We measure for the first time the RM effect of the Earth transiting the Sun using a lunar eclipse observed with the ESO HARPS spectrograph. We analyze the observed RM effect at different wavelengths to obtain the transmission spectrum of the Earth's atmosphere after the correction of the solar limb-darkening and the convective blueshift. The ozone Chappuis band absorption as well as the Rayleigh scattering features are clearly detectable with this technique. Our observation demonstrates that the RM effect can be an effective technique for exoplanet atmosphere characterization. Its particular asset is that photometric reference stars are not required, circumventing the principal challenge for transmission spectroscopy studies of exoplanet atmospheres using large ground-based telescopes.
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