An Empirical Air-to-Ground Channel Model Based on Passive Measurements in LTE

In this paper, a recently conducted measurement campaign for unmanned-aerial-vehicle (UAV) channels is introduced. The downlink signals of an in-service long-time-evolution (LTE) network which is deployed in a suburban scenario were acquired. Five horizontal and five vertical flight routes were considered. The channel impulse responses (CIRs) are extracted from the received data by exploiting the cell specific signals (CRSs). Based on the CIRs, the parameters of multipath components (MPCs) are estimated by using a high-resolution algorithm derived according to the space-alternating generalized expectation-maximization (SAGE) principle. Based on the SAGE results, channel characteristics including the path loss, shadow fading, fast fading, delay spread and Doppler frequency spread are thoroughly investigated for different heights and horizontal distances, which constitute a stochastic model.Comment: 15 pages, submitted version to IEEE Transactions on Vehicular Technology. Current status: Early acces

Dithiothreitol increases f3-glucuronidase accumulation in transformed tobacco (Nicotiana tabacum) protoplasts without altering their viability or the synthesis and export of cellular proteins

The effect of dithiothreitol (DTT) on the expression of the β-glucuronidase (GUS) reporter gene under the control of the CaMV-35 S promoter has been investigated by radioactive labelling and immunoprecipitation of the enzyme in protoplasts from stably transformed tobacco plants and compared with that observed in protoplasts transiently expressing the same gene construct. An increase in net accumulation of GUS during the culture period in response to externally added DTT (2 mm) was observed both in protoplasts from transformed tobacco plants and in electroporated protoplasts. DTT had no effect on rate of degradation of the mature GUS protein, as shown in a pulse-chase experiment. Relevant aspects of protoplast physiology, such as viability, synthesis of 35S-labelled cellular proteins, or synthesis and export of pathogenesis-related proteins (one putative chitinase and two 1,3-β-glucanases) were not affected by the reducing reagen

Fermiology and transport properties of the half-metallic itinerant ferromagnet CoS2_2: influence of spin orbit coupling

Electronic structure calculations were performed on the compound CoS$_2$, an itinerant ferromagnet whose magnetic properties can be understood in terms of spin fluctuation theory. We have identified nesting features in the Fermi surface of the compound, active for long wavelength spin fluctuations. The electronic structure of the material is close to a half-metal. We show the importance of introducing spin-orbit coupling (SOC) in the calculations, that partially destroys the half-metallicity of the material. By means of transport properties calculations, we have quantified the influence of SOC in the conductivity at room temperature, with an important decrease comparing to the GGA alone conductivity. SOC also helps to understand the negative 0 of the material, whose conductivity varies by a few percent with the introduction of small perturbations in the states around the Fermi level.Comment: 8 pages, 8 figure

Pressure-induced metal-insulator transition in MgV_2O_4

On the basis of experimental thermoelectric power results and ab initio calculations, we propose that a metal-insulator transition takes place at high pressure (approximately 6 GPa) in MgV_2O_4.Comment: 2 pages, 3 figures, accepted in Physica B (Strongly Correlated Electron Systems '07

Enhanced dimerization of TiOCl under pressure: spin-Peierls - to - Peierls transition

We report high-pressure x-ray diffraction and magnetization measurements combined with ab-initio calculations to demonstrate that the high-pressure optical and transport transitions recently reported in TiOCl, correspond in fact to an enhanced Ti3+-Ti3+ dimerization existing already at room temperature. Our results confirm the formation of a metal-metal bond between Ti3+ ions along the b-axis of TiOCl, accompanied by a strong reduction of the electronic gap. The evolution of the dimerization with pressure suggests a crossover from the spin-Peierls to a conventional Peierls situation at high pressures.Comment: 9pages, 4 figure

Efecto de la vitamina e en la alimentación del pavo en la acumulación tisular y estabilidad oxidativa.

El presente trabajo pretende evaluar la efectividad de las formas naturales de vitamina E en la acumulación tisular de tocoferol, así como en la estabilidad oxidativa in vivo y postmortem. El único factor de diferenciación fue el tipo de vitamina E (natural vs sintética) y concentración (Baja: 40 ppm y alta: 120 ppm) en el pienso. Adicionalmente se produjo un grupo control sin vitamina E añadida en el pienso. Se ha observado una relación dosisrespuesta lineal en la concentración de tocoferol en el plasma de los pavos, así como una tendencia (P=0.139) hacia una mayor concentración en los animales que recibieron la vitamina E en forma natural.. Existe una relación entre la concentración de tocoferol y de Metamioglobina en el músculo en el día 9 de almacenamiento refrigerado, evidenciándose una mayor efectividad de la forma natural. Se ha observado una menor concentración de ácidos grasos saturados en el grupo control y el de bajo nivel de suplementación. Asimismo, existe una tendencia hacia una menor concentración d estos ácidos grasos en los animales que reciben la forma natural de vitamina E (P=0,0658)

Short-term effects on soil properties and wheat production from secondary paper sludge application on two Mediterranean agricultural soils

This study was conducted under greenhouse conditions to evaluate the potential use of SPS as a fertilizer, amendment and/or liming agent for wheat (Triticum aestivum L.). Two representative Mediterranean agricultural soils, a Cambic Arenosol (cmAR) and a Cromic Cambisol (crCM) were used. Treatments included four sludge rates ranging from 0 to 40 g kg 1 (equivalent of 0, 38, 88 and 120 Mg ha 1). A significant increment in soil pH, organic carbon, N total, available P and exchangeable K were observed in both soils. Sludge application significantly increased N and decreased Zn, Mn and Cu concentrations in wheat. Wheat grain yields were reduced by 33% and 37% when 120 Mg SPS ha 1 was applied to cmAR and crCM soils, respectively, due apparently to unavailability of Mg. However, straw yields, with much lower Mg requirements, increased significantly with SPS rates. Secondary pulp mill sludge seems to be a potential source of organic matter, N, P, K and a potential soil amendment liming agent for acid soils, when appropriate supplemental fertilizer was provided. For grain crops grown in these soils, addition of Mg is required for proper nutrient balance

Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering: Determined by the OLYMPUS Experiment

The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, $R_{2\gamma}$, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of $\approx 20\degree$ to $80\degree$. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved GEM and MWPC detectors at $12\degree$, as well as symmetric M{\o}ller/Bhabha calorimeters at $1.29\degree$. A total integrated luminosity of 4.5~fb$^{-1}$ was collected. In the extraction of $R_{2\gamma}$, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of $R_{2\gamma}$, presented here for a wide range of virtual photon polarization $0.456<\epsilon<0.978$, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.Comment: 5 pages, 3 figures, 2 table

El tiempo del espacio: el espacio del tiempo

[EN] The transdisciplinary adventure that arises from the rapid expansion of new technologies, poses unprecedented ways of being and being there in the world. The questions about how they present and represent the different areas of what we know as physical, sensory, social or biological reality, show the complexity horizon beyond the traditional understanding of the artwork; while forcing us to redefine almost constantly, at time intervals ranging more hastily than we can comprehend. Time and space are always surrounding and present in every one of transitions or ideas about thinking, express and represent the uniqueness in all developmental stages of our journey concepts. The reason, poetry, science or technology, have left traces of the great paradox that surrounds the movement; making us wonder if perhaps the vacuum space, which may reveal the artifice of motion, or if misguided attempts to uncover the origin of it, will be the answer. In order to reach a much more complex knowledge, we must form our own paths , since in terms of time and space we are talking about, it seems that everything ends defined and vanishes by itself. The legitimacy of an extensive philosophical, scientific or epistemological heritage, is subject to dialogue between the different places of knowledge and interest in developing a complex way of thinking about human experience , to recover the wonder of the mystery of uncertainty. In the technological age, this is a compilation of concepts articulated in a vast and boundless intellectual mesh. The future however, demand poetry to the retrospective light of digital challenge .[ES] La aventura transdisciplinar que nace de la vertiginosa expansión de las nuevas tecnologías, plantea modos inéditos de ser y estar en el mundo. Los interrogantes acerca de cómo se presentan y representan los diferentes ámbitos de lo que conocemos como realidad física, sensorial, social o biológica, evidencian la complejidad de superar el horizonte tradicional de comprensión de la obra de arte; al tiempo que nos obliga a redefinirla casi constantemente, en intervalos temporales que van más apresuradamente de lo que podemos abarcar. El tiempo y el espacio son conceptos siempre circundantes y presentes en todas y cada una de las transiciones o ideas con respecto a pensar, expresar y representar la singularidad en todos los estadios evolutivos de nuestro camino. La razón, la poesía, la ciencia o la tecnología, han dejado vestigios de la gran paradoja que envuelve al movimiento; haciendo que nos preguntemos si es acaso el espacio del vacío, el que podrá revelar los artificios del movimiento, o si los intentos errados por desvelar el origen de éste, serán la respuesta. A fin de llegar a un conocimiento mucho mas complejo, tendremos que formar nuestras propias trayectorias, ya que en lo referente al tiempo y al espacio del que estamos hablando, pareciera que todo lo definido concluye y se desvanece por sí mismo. La legitimidad de una extensa herencia filosófica, científica o epistemológica, queda sometida al diálogo entre los diferentes lugares del conocimiento y a su interés por desarrollar un modo complejo de pensar la experiencia humana, que recupere el asombro por el misterio de lo incierto. En la era tecnológica, el presente es una compilación de conceptos articulados en una extensa y desmesurada malla intelectual. El futuro sin embargo, demanda poesía a la luz retrospectiva del desafío digital.F. Piñeiro, U. (2015). El tiempo del espacio: el espacio del tiempo. En II CONGRESO INTERNACIONAL DE INVESTIGACIÓN DE ARTES VISUALES. Editorial Universitat Politècnica de València. 827-831. https://doi.org/10.4995/ANIAV2015.1119OCS82783