Diferenciación stomodeal mecanismos formales de la división de la boca primitiva

Tesis de la Universidad Complutense de Madrid, Facultad de Medicina, Departamento de Ciencias Morfológicas, leída el 20-12-2002Depto. de Anatomía y EmbriologíaFac. de MedicinaTRUEpu

Energy-Efficient UAVs Deployment for QoS-Guaranteed VoWiFi Service

This paper formulates a new problem for the optimal placement of Unmanned Aerial Vehicles (UAVs) geared towards wireless coverage provision for Voice over WiFi (VoWiFi) service to a set of ground users confined in an open area. Our objective function is constrained by coverage and by VoIP speech quality and minimizes the ratio between the number of UAVs deployed and energy efficiency in UAVs, hence providing the layout that requires fewer UAVs per hour of service. Solutions provide the number and position of UAVs to be deployed, and are found using well-known heuristic search methods such as genetic algorithms (used for the initial deployment of UAVs), or particle swarm optimization (used for the periodical update of the positions). We examine two communication services: (a) one bidirectional VoWiFi channel per user; (b) single broadcast VoWiFi channel for announcements. For these services, we study the results obtained for an increasing number of users confined in a small area of 100 m2 as well as in a large area of 10,000 m2. Results show that the drone turnover rate is related to both users’ sparsity and the number of users served by each UAV. For the unicast service, the ratio of UAVs per hour of service tends to increase with user sparsity and the power of radio communication represents 14–16% of the total UAV energy consumption depending on ground user density. In large areas, solutions tend to locate UAVs at higher altitudes seeking increased coverage, which increases energy consumption due to hovering. However, in the VoWiFi broadcast communication service, the traffic is scarce, and solutions are mostly constrained only by coverage. This results in fewer UAVs deployed, less total power consumption (between 20% and 75%), and less sensitivity to the number of served users.Junta de Andalucía Beca 2020/00000172Unión Europea FEDER 2014-202

Assessing the effect of public subsidies on firm R&D investment : a survey

This survey examines the empirical literature on the relationship between public R&D subsidies and private R&D investment over the past five decades. The survey reveals a considerable heterogeneity of empirical results that cannot be explained fully by methodological issues. We aim to provide further explanations of the possible causes of that heterogeneity. In particular, we emphasise a set of issues that, in our view, are critical to understanding the potential effect of public R&D subsidies on private R&D spending. Special attention is paid to the dynamic aspects and composition of firm R&D, the constraints faced by the firm (such as financial constraints), and the amount and source of public subsidies. None of these issues have been investigated in depth. We formulate a set of research assumptions to guide future empirical research in this field

Endovascular treatment of thoracic aorta injury after spinal column surgery

Producción CientíficaA 61-year-old woman with a history of left dorso-lumbar scoliosis and severe dorso-lumbar kyphosis underwent surgical treatment of a spinal deformity. Surgery was conducted on the patient by performing a dorso-lumbar spinal arthrodesis (T6-L5) by means of the insertion of two longitudinal rods and a number of pedicle-expander screws at different vertebral levels. Following the orthopedic surgery, the patient presented paraparesis of the lower limbs and anemia that required transfusion. In the immediate postoperative period, a noncontrast-enhanced computed tomography (CT) scan was obtained to assess the medullary canal. A deviation of the left screw placed at T6 was detected; this screw projected outward from the vertebral cortex, protruding into the descending thoracic aorta. A contrast-enhanced CT scan showed that the screw had been malpositioned, and the image was highly suggestive of a perforation of the aortic wall, despite a lack of evidence of a peri-aortic hematoma, extravasation of contrast medium, or pleural effusion. The patient remained hemodynamically stable, and the decision was to perform an endovascular repair electively within 24 hours

Influence of the subestructure irregularity in highway bridge seismic behaviour

Most of preliminary evaluation methods to accomplish the seismic vulnerability of bridges consider as an evaluation parameter the substructure irregularity. This parameter is estimated by means of the difference in the length of piers or through the pier typology, but both evaluated by a subjective form. In this paper the evaluation of the influence of substructure irregularity is presented. First, a simple and regular bridge, with three piers of equal length and four spans, is considered as an original structure. Starting from this system, different irregular models were elaborated reducing or incrementing the length of the central or one of the external piers, in percentages of 25%, 50% and 75%. As a seismic action, a database of more than 50 earthquakes, registered in the Mexican Pacific Coast, the most seismic hazardous zone of México, were considered. The selected registers have magnitudes greater than six and important peak ground accelerations. By means of elastic analyses, the variation between regular and irregular maximum responses in displacements and internal forces are determined. Of the obtained responses, statistical values as mean and standard deviation are evaluated. With these values, percentages of difference in the response of irregular bridges were estimated; these percentages could be included as fragility weights of the irregularity degree in more rigorous preliminary methods to evaluate the seismic vulnerability of bridges.Postprint (published version

Silene gazulensis sp. Nov. (Caryophyllaceae): un nuevo endemismo del entorno del estrecho de Gibraltar

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Datos sobre la vegetación de los llanos occidentales del Orinoco (Venezuela)

RESUMEN. Datos sobre la vegetación de los Llanos Occidentales del Orinoco (Venezuela). Los Llanos Occidentales del Orinoco se caracterizan por ser una gran cuenca sedimentaria donde se alternan sustratos arcillosos y arenosos. El bioclima infratropical subhúmedo y la cantidad de ambientes palustres originan una gran diversidad de comunidades vegetales, en especial de helófitos, pleustohelófitos e hidrófitos. Cuando la inundación es más escasa, aparecen los bosques, arbustedas y los pastos secos de la sabana, que forman isleos de comunidades vegetales en medio de la llanura inundable. Hemos podido reconocer 17 asociaciones repartidas en 10 clases fitosociológicas: Cabombo- Nymphaeetea (comunidades de hidrófitos), Ceibetea occidentalis (bosques y arbustedas), Cladietea jamaicensis (comunidades de helófitos), Coccolobietea obtusifoliae (arbustedas riparias), Lemnetea minoris (comunidades de pleustófitos), Leptocoryphio-Trachypogonetea (pastizales secos de la sabana), Pistio stratiotidis-Eichhornietea crassipedis (comunidades de pleustohelófitos), Polygono arenastri-Poetea annuae (comunidades nitrófilas resistentes al pisoteo), Sido-Stachytarphetaetea (comunidades nitrófilas) y Xyridetea savanensis (pastizales temporalmente inundados con plantas anuales). Además, describimos como novedades sintaxonómicas 4 asociaciones (Bromelio chrysanthae- Platymiscietum pinnati, Geophiletum repentis, Helictero guazumifoliae-Bauhinietum benthamianae y Randio venezuelensis-Annonetum jahnii), 6 alianzas (Coccolobion obtusifoliae, Desmonco orthacanthi-Platymiscion pinnati, Heterantherion reniformis, Nectandro globosae-Viticion orinocensis, Oryzion perennis y Wissadulo periplocifoliae-Cassion torae), 3 órdenes (Bactrido guineensis-Cecropietalia peltatae, Coccolobietalia obtusifoliae y Eleocharitetalia minimae) y 1 clase (Coccolobietea obtusifoliae).Palabras clave. Vegetación, sintaxonomía, Llanos, Venezuela.ABSTRACT. Data about the vegetation of the Occidental Llanos of the Orinoco (Venezuela). The western Llanos of the Orinoco river are a sedimentary basin of sandy and clayey mixed soils. The infratropical subhumid bioclimate and the large marshes cause a high diversity of plant communities consisting specially of helophytes, pleustohelophytes and hydrophytes. When there is a little flooding, forest, shrubs and dry pastures of the savannas appear, forming islands of plant communities in the swampy plain. Seventeen associations belonging to 10 classes have been recognized (Cabombo- Nymphaeetea (hydrophytic communities), Ceibetea occidentalis (forests and shrubs), Cladietea jamaicensis (helophytic communities), Coccolobietea obtusifoliae (riparian shrubs), Lemnetea minoris (pleustophytic communities), Leptocoryphio-Trachypogonetea (dry pastures of the savanna), Pistio stratiotidis-Eichhornietea crassipedis (pleustohelophytic communities), Polygono arenastri-Poetea annuae (nitrophilous communities adapted to treading), Sido-Stachytarphetaetea (nitrophilous communities) and Xyridetea savanensis (temporal flooded pastures with annual plants). Moreover, 4 new associations (Bromelio chrysanthae-Platymiscietum pinnati, Geophiletum repentis, Helictero guazumifoliae-Bauhinietum benthamianae and Randio venezuelensis-Annonetum jahnii), 6 alliances (Coccolobion obtusifoliae, Desmonco orthacanthi-Platymiscion pinnati, Heterantherion reniformis, Nectandro globosae-Viticion orinocensis, Oryzion perennis y Wissadulo periplocifoliae-Cassion torae), 3 orders (Bactrido guineensis-Cecropietalia peltatae, Coccolobietalia obtusifoliae and Eleocharitetalia minimae) and 1 class (Coccolobietea obtusifoliae) are described.Key words. Vegetation, syntaxonomy, Llanos, Venezuela

Autonomous Vehicle Based in Cooperative GPS and Intertial Systems

A system including Global Positioning Systems (GPS) and digital cartography is a good solution to carry out vehicle's guidance. However, it has inconveniences like high sensibility to multipath and interference when the GPS signal is blocked by external agents. Another system is mandatory to avoid this error. This paper presents a cooperative system based on GPS and Inertial Navigation Systems (INS) for automated vehicle position. The control system includes a decision unit to choose which value is the correct. In case GPS is working at top precision, it takes the control. On the other part, GPS signal can be lost and inertial control system guides the car in this occasion. A third possibility is contemplated: we receive the signal from GPS but the accuracy is over one meter. Now, position value is obtained by means of both systems. Experimental results analyze two situations: guidance in an urban area where GPS signal can be occluded by buildings or trees during short time intervals and the possibility of loss of the signal in long time to simulate the circulation in tunnels. Good results have been observed in tests and it demonstrates how a cooperative system improves the automated vehicle guidance