Thirteen juvenile Golden Eagles Aquila chrysaetos were tracked during their first year of life us... more Thirteen juvenile Golden Eagles Aquila chrysaetos were tracked during their first year of life using satellite telemetry. Distances to the nest attained during that period and the age at the onset of juvenile dispersal were explored. The performance of nine different criteria to determine that age was analysed. In general, after a brief period of restricted movements around the nest, the average distance to the nest increased with time. Maximum distances to the nest ranged between 57.7 and 184.3 km, and were considerably greater in females (mean ± sd, 138.5 ± 44.5 km) than in males (70.5 ± 14.0 km). No sex difference was observed in the age at which that distance was attained (males: 329 ± 32 days, females: 312 ± 20 days). The onset of juvenile dispersal took place around the fifth month of life (September in Spain). Eight of the nine criteria provided similar results, suggesting that in Spain dispersal starts when birds are between 140 and 180 days old, and that the post-nestling period lasts between 60 and 120 days. For future studies, to determine the age at which the onset of juvenile dispersal occurs, we recommend the use of either the first day on which individuals were located beyond the mean distance between nests of different pairs (10 km in our study area), or the date of the record midway between the first and the last location recorded during the month in which the maximum variability in the distance to the nest was observed.
This paper proposes a novel control for voltagesource inverters with the capability to flexibly o... more This paper proposes a novel control for voltagesource inverters with the capability to flexibly operate in gridconnected and islanded modes. The control scheme is based on the droop method, which uses some estimated grid parameters such as the voltage and frequency and the magnitude and angle of the grid impedance. Hence, the inverter is able to inject independently active and reactive power to the grid. The controller provides a proper dynamics decoupled from the grid-impedance magnitude and phase. The system is also able to control active and reactive power flows independently for a large range of impedance grid values. Simulation and experimental results are provided in order to show the feasibility of the control proposed.
Protected natural areas (PNAs) are the most important strategy related to environmental conservat... more Protected natural areas (PNAs) are the most important strategy related to environmental conservation policies worldwide. For such a declaration to be made, Spanish law demands that a technically comprehensive specific natural resources plan (SNRP) be legally approved. The SNRP is a normative document with prevalence over the national, regional and local laws affecting the area. This prominent legal position guarantees the achievement of the nature conservation objectives. Since SNRP restricts human uses of the area, the SNRP is of great importance to local inhabitants and stakeholders. Their agreement is socially necessary if a rapid and trouble-free declaration of PNA status is to be made. The most useful tool for seeking such agreement is a public information program (PIP). It must be well designed and developed to be successful. The main objectives of a PIP can be summarized with the following words or concepts. Justice: the PIP make come true the right of citizens to participate; adequacy: the PIP will improve the obtained planning; and effectiveness: the PIP is an effective instrument to achieve acquiescence of the affected population. To achieve the above objectives is necessary to design and develop the activities of PIP based on the following criteria. Consider local resident motivations and give personalized information. Promote participation and discussion regarding the purpose of the PNA. Establish transparency and representation. Implement planning, continuity, monitoring and control. A model for a PIP is proposed. This model is based on the experience gathered in the declaration of the Alto Tajo Natural Park in central Spain. It is useful for other proposed PNA. The main practical considerations for a PIP designthe different activities undertaken, as well as the most important factors in PIP successare also described and discussed. The attempts to establish the Alto Tajo area with PNA status failed on three occasions (1974, 1981 and 1989) due mainly to the opposition of local residents and stakeholders. Following a PIP carried out between 1996 and 2000, local residents and stakeholders saw the declaration of the PNA in a very favourable light; and, finally, the Alto Tajo Natural Park was declared in 2000.
This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparatio... more This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparations of a vaccine composed of whole antigens from killed promastigotes of Leishmania amazonensis. Leishmanin skin-test (LST)-negative volunteers were immunized with either autoclaved or nonautoclaved vaccine preparations (32 and 36 subjects, respectively) that had been maintained at 48C for one year before the onset of this trial. Immunological tests were performed two days before and 40 days after vaccination. The LST conversion rates induced by the autoclaved and nonautoclaved vaccines were signi®cantly dierent: 59% and 83%, respectively. Leishmania antigen-stimulated proliferative responses of peripheral blood mononuclear cells (PBMC) were signi®cantly higher after vaccination than before vaccination in both groups. The CD8 + subset was predominant over the CD4 + subset among the leishmania-reactive cells after vaccination in both groups. The production of IFN-g by the leishmania antigen-stimulated PBMC was signi®cantly higher after vaccination than before vaccination in the group receiving the nonautoclaved vaccine but not in the autoclaved vaccine group. IL-2 was found both before and after vaccination with no dierences between its levels in these time points in either group. IL-4 was not detected for either group during the study period. #
The location of the instantaneous screw axis (ISA) is essential in order to obtain useful kinemat... more The location of the instantaneous screw axis (ISA) is essential in order to obtain useful kinematic models of the human body for applications such as prosthesis and orthoses design or even to help in disease diagnosis techniques. In this paper, dual vectors will be used to represent and operate with kinematic screws with the purpose of locating the instantaneous screw axes which characterize this instantaneous motion. A photogrammetry system based on markers will be used to obtain the experimental data from which the kinematic magnitudes will be obtained. A comprehensive analysis of the errors in the measurement of kinematic parameters has been developed, obtaining explicit expressions for them based on the number of markers and their distribution. Finally, the developed methodology has been applied to the experimental determination of the ISA during an alternative motion of flexion and extension of the back.
Between 2006 and 2008, 14 Montagu’s Harriers (Circus pygargus) were tagged with satellite transmi... more Between 2006 and 2008, 14 Montagu’s Harriers (Circus pygargus) were tagged with satellite transmitters at their breeding grounds in NE Spain, recording a total of 18 autumn and 10 spring journeys. In both autumn and spring migrations, harriers migrated between Europe and West Africa along a relatively narrow corridor between the coast of Morocco and Western Sahara and the western border of Algeria. Birds tended to follow a slightly more westerly track during spring migration compared to autumn migration. Harriers started autumn migration in late August–early September, arriving at their wintering grounds in early–mid-September, after travelling between 8 and 25 days, and covering a mean of 187 km a day. Spring migration started in mid-March, with birds arriving at the breeding grounds in mid-April after covering a mean of 114 km a day. On average, spring migration lasted longer, with birds covering longer distances than during autumn migration, and distances travelled in a day tended to be shorter. Significant differences in the routes followed by harriers were observed among seasons and individuals, with the same individuals following different routes in different years. Wintering areas were located in northern Senegal and the southern border of Mauritania with Mali, with some birds breeding in the same colony in Europe separated more than 1,200 km during the wintering season. Birds showed a relatively high fidelity to their wintering areas. Several birds moved from one area to another during the wintering period, which resulted in larger wintering areas, whereas others remained in the same area during the whole wintering season. Zwischen 2006 und 2008 wurden 14 Wiesenweihen (Circus pygargus) in ihren Brutgebieten in Nordostspanien mit Satellitensendern versehen und insgesamt 18 Herbst- und zehn Frühjahrszugwege aufgezeichnet. Sowohl auf dem Herbst- als auch auf dem Frühjahrszug zogen die Weihen zwischen Europa und Westafrika in einem relativ engen Korridor zwischen der Küste Marokkos und der westlichen Sahara und der Westgrenze von Algerien. Die Vögel tendierten dazu, auf dem Frühjahrszug einem etwas westlicheren Kurs verglichen mit dem Herbstzug zu folgen. Die Weihen begannen mit dem Herbstzug Ende August bis Anfang September und kamen in ihren Überwinterungsgebieten Anfang bis Mitte September an, nachdem sie zwischen acht und 25 Tage geflogen waren und im Mittel 187 km pro Tag zurückgelegt hatten. Der Frühjahrszug setzte Mitte März ein, und die Vögel trafen Mitte April in ihren Brutgebieten ein, wobei sie im Mittel 114 km pro Tag flogen. Der Frühjahrszug dauerte im Durchschnitt länger als der Herbstzug, die Vögel legten größere Entfernungen zurück, und die an einem Tag zurückgelegte Entfernung war tendenziell kürzer. Zwischen verschiedenen Saisons und Individuen wurden signifikante Unterschiede in den von den Weihen geflogenen Routen beobachtet, und dieselben Tiere nutzten verschiedene Routen in verschiedenen Jahren. Die Überwinterungsgebiete lagen in Nordsenegal und an der Südgrenze Mauretaniens zu Mali. Einige Vögel, die in Europa in derselben Kolonie brüteten, überwinterten mehr als 1,200 km voneinander entfernt. Die Weihen zeigten eine relativ ausgeprägte Treue zu ihren Überwinterungsgebieten. Einige Vögel zogen während der Überwinterungsperiode von einem Gebiet zu einem anderen, was in insgesamt größeren Überwinterungsgebieten resultierte, wohingegen andere während der gesamten Wintersaison im selben Gebiet blieben.
Journal of Infection (2007) 55, 260e266 imipenem-resistant), 115 (85.1%) were distributed among 1... more Journal of Infection (2007) 55, 260e266 imipenem-resistant), 115 (85.1%) were distributed among 14 clusters and 20 were unrelated. Of the imipenem-resistant isolates, 45 (70.3%) belonged to six clusters that also had imipenemsusceptible isolates; 14 constituted four exclusive clusters, and five were unrelated. Conclusions: Acquisition of imipenem resistance in A. baumannii is likely due to both clonal and non-clonal dissemination; resistance rates strongly vary between different hospitals and even between different hospital departments.
This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (W... more This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (WTs) based on doubly fed induction generators (DFIG) that intends to improve its low-voltage ride through capability. The main objective of this work is to design an algorithm that would enable the system to control the initial overcurrents that appear in the generator during voltage sags, which can damage the RSC, without tripping it. As a difference with classical solutions, based on the installation of crowbar circuits, this operation mode permits to keep the inverter connected to the generator, something that would permit the injection of power to the grid during the fault, as the new grid codes demand. A theoretical study of the dynamical behavior of the rotor voltage is also developed, in order to show that the voltage at the rotor terminals required for the control strategy implementation remains under controllable limits. In order to validate the proposed control system simulation, results have been collected using PSCAD/EMTDC and experimental tests have been carried out in a scaled prototype.
Thirteen juvenile Golden Eagles Aquila chrysaetos were tracked during their first year of life us... more Thirteen juvenile Golden Eagles Aquila chrysaetos were tracked during their first year of life using satellite telemetry. Distances to the nest attained during that period and the age at the onset of juvenile dispersal were explored. The performance of nine different criteria to determine that age was analysed. In general, after a brief period of restricted movements around the nest, the average distance to the nest increased with time. Maximum distances to the nest ranged between 57.7 and 184.3 km, and were considerably greater in females (mean ± sd, 138.5 ± 44.5 km) than in males (70.5 ± 14.0 km). No sex difference was observed in the age at which that distance was attained (males: 329 ± 32 days, females: 312 ± 20 days). The onset of juvenile dispersal took place around the fifth month of life (September in Spain). Eight of the nine criteria provided similar results, suggesting that in Spain dispersal starts when birds are between 140 and 180 days old, and that the post-nestling period lasts between 60 and 120 days. For future studies, to determine the age at which the onset of juvenile dispersal occurs, we recommend the use of either the first day on which individuals were located beyond the mean distance between nests of different pairs (10 km in our study area), or the date of the record midway between the first and the last location recorded during the month in which the maximum variability in the distance to the nest was observed.
This paper proposes a novel control for voltagesource inverters with the capability to flexibly o... more This paper proposes a novel control for voltagesource inverters with the capability to flexibly operate in gridconnected and islanded modes. The control scheme is based on the droop method, which uses some estimated grid parameters such as the voltage and frequency and the magnitude and angle of the grid impedance. Hence, the inverter is able to inject independently active and reactive power to the grid. The controller provides a proper dynamics decoupled from the grid-impedance magnitude and phase. The system is also able to control active and reactive power flows independently for a large range of impedance grid values. Simulation and experimental results are provided in order to show the feasibility of the control proposed.
Protected natural areas (PNAs) are the most important strategy related to environmental conservat... more Protected natural areas (PNAs) are the most important strategy related to environmental conservation policies worldwide. For such a declaration to be made, Spanish law demands that a technically comprehensive specific natural resources plan (SNRP) be legally approved. The SNRP is a normative document with prevalence over the national, regional and local laws affecting the area. This prominent legal position guarantees the achievement of the nature conservation objectives. Since SNRP restricts human uses of the area, the SNRP is of great importance to local inhabitants and stakeholders. Their agreement is socially necessary if a rapid and trouble-free declaration of PNA status is to be made. The most useful tool for seeking such agreement is a public information program (PIP). It must be well designed and developed to be successful. The main objectives of a PIP can be summarized with the following words or concepts. Justice: the PIP make come true the right of citizens to participate; adequacy: the PIP will improve the obtained planning; and effectiveness: the PIP is an effective instrument to achieve acquiescence of the affected population. To achieve the above objectives is necessary to design and develop the activities of PIP based on the following criteria. Consider local resident motivations and give personalized information. Promote participation and discussion regarding the purpose of the PNA. Establish transparency and representation. Implement planning, continuity, monitoring and control. A model for a PIP is proposed. This model is based on the experience gathered in the declaration of the Alto Tajo Natural Park in central Spain. It is useful for other proposed PNA. The main practical considerations for a PIP designthe different activities undertaken, as well as the most important factors in PIP successare also described and discussed. The attempts to establish the Alto Tajo area with PNA status failed on three occasions (1974, 1981 and 1989) due mainly to the opposition of local residents and stakeholders. Following a PIP carried out between 1996 and 2000, local residents and stakeholders saw the declaration of the PNA in a very favourable light; and, finally, the Alto Tajo Natural Park was declared in 2000.
This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparatio... more This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparations of a vaccine composed of whole antigens from killed promastigotes of Leishmania amazonensis. Leishmanin skin-test (LST)-negative volunteers were immunized with either autoclaved or nonautoclaved vaccine preparations (32 and 36 subjects, respectively) that had been maintained at 48C for one year before the onset of this trial. Immunological tests were performed two days before and 40 days after vaccination. The LST conversion rates induced by the autoclaved and nonautoclaved vaccines were signi®cantly dierent: 59% and 83%, respectively. Leishmania antigen-stimulated proliferative responses of peripheral blood mononuclear cells (PBMC) were signi®cantly higher after vaccination than before vaccination in both groups. The CD8 + subset was predominant over the CD4 + subset among the leishmania-reactive cells after vaccination in both groups. The production of IFN-g by the leishmania antigen-stimulated PBMC was signi®cantly higher after vaccination than before vaccination in the group receiving the nonautoclaved vaccine but not in the autoclaved vaccine group. IL-2 was found both before and after vaccination with no dierences between its levels in these time points in either group. IL-4 was not detected for either group during the study period. #
The location of the instantaneous screw axis (ISA) is essential in order to obtain useful kinemat... more The location of the instantaneous screw axis (ISA) is essential in order to obtain useful kinematic models of the human body for applications such as prosthesis and orthoses design or even to help in disease diagnosis techniques. In this paper, dual vectors will be used to represent and operate with kinematic screws with the purpose of locating the instantaneous screw axes which characterize this instantaneous motion. A photogrammetry system based on markers will be used to obtain the experimental data from which the kinematic magnitudes will be obtained. A comprehensive analysis of the errors in the measurement of kinematic parameters has been developed, obtaining explicit expressions for them based on the number of markers and their distribution. Finally, the developed methodology has been applied to the experimental determination of the ISA during an alternative motion of flexion and extension of the back.
Between 2006 and 2008, 14 Montagu’s Harriers (Circus pygargus) were tagged with satellite transmi... more Between 2006 and 2008, 14 Montagu’s Harriers (Circus pygargus) were tagged with satellite transmitters at their breeding grounds in NE Spain, recording a total of 18 autumn and 10 spring journeys. In both autumn and spring migrations, harriers migrated between Europe and West Africa along a relatively narrow corridor between the coast of Morocco and Western Sahara and the western border of Algeria. Birds tended to follow a slightly more westerly track during spring migration compared to autumn migration. Harriers started autumn migration in late August–early September, arriving at their wintering grounds in early–mid-September, after travelling between 8 and 25 days, and covering a mean of 187 km a day. Spring migration started in mid-March, with birds arriving at the breeding grounds in mid-April after covering a mean of 114 km a day. On average, spring migration lasted longer, with birds covering longer distances than during autumn migration, and distances travelled in a day tended to be shorter. Significant differences in the routes followed by harriers were observed among seasons and individuals, with the same individuals following different routes in different years. Wintering areas were located in northern Senegal and the southern border of Mauritania with Mali, with some birds breeding in the same colony in Europe separated more than 1,200 km during the wintering season. Birds showed a relatively high fidelity to their wintering areas. Several birds moved from one area to another during the wintering period, which resulted in larger wintering areas, whereas others remained in the same area during the whole wintering season. Zwischen 2006 und 2008 wurden 14 Wiesenweihen (Circus pygargus) in ihren Brutgebieten in Nordostspanien mit Satellitensendern versehen und insgesamt 18 Herbst- und zehn Frühjahrszugwege aufgezeichnet. Sowohl auf dem Herbst- als auch auf dem Frühjahrszug zogen die Weihen zwischen Europa und Westafrika in einem relativ engen Korridor zwischen der Küste Marokkos und der westlichen Sahara und der Westgrenze von Algerien. Die Vögel tendierten dazu, auf dem Frühjahrszug einem etwas westlicheren Kurs verglichen mit dem Herbstzug zu folgen. Die Weihen begannen mit dem Herbstzug Ende August bis Anfang September und kamen in ihren Überwinterungsgebieten Anfang bis Mitte September an, nachdem sie zwischen acht und 25 Tage geflogen waren und im Mittel 187 km pro Tag zurückgelegt hatten. Der Frühjahrszug setzte Mitte März ein, und die Vögel trafen Mitte April in ihren Brutgebieten ein, wobei sie im Mittel 114 km pro Tag flogen. Der Frühjahrszug dauerte im Durchschnitt länger als der Herbstzug, die Vögel legten größere Entfernungen zurück, und die an einem Tag zurückgelegte Entfernung war tendenziell kürzer. Zwischen verschiedenen Saisons und Individuen wurden signifikante Unterschiede in den von den Weihen geflogenen Routen beobachtet, und dieselben Tiere nutzten verschiedene Routen in verschiedenen Jahren. Die Überwinterungsgebiete lagen in Nordsenegal und an der Südgrenze Mauretaniens zu Mali. Einige Vögel, die in Europa in derselben Kolonie brüteten, überwinterten mehr als 1,200 km voneinander entfernt. Die Weihen zeigten eine relativ ausgeprägte Treue zu ihren Überwinterungsgebieten. Einige Vögel zogen während der Überwinterungsperiode von einem Gebiet zu einem anderen, was in insgesamt größeren Überwinterungsgebieten resultierte, wohingegen andere während der gesamten Wintersaison im selben Gebiet blieben.
Journal of Infection (2007) 55, 260e266 imipenem-resistant), 115 (85.1%) were distributed among 1... more Journal of Infection (2007) 55, 260e266 imipenem-resistant), 115 (85.1%) were distributed among 14 clusters and 20 were unrelated. Of the imipenem-resistant isolates, 45 (70.3%) belonged to six clusters that also had imipenemsusceptible isolates; 14 constituted four exclusive clusters, and five were unrelated. Conclusions: Acquisition of imipenem resistance in A. baumannii is likely due to both clonal and non-clonal dissemination; resistance rates strongly vary between different hospitals and even between different hospital departments.
This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (W... more This paper presents a new control strategy for the rotor-side converter (RSC) of wind turbines (WTs) based on doubly fed induction generators (DFIG) that intends to improve its low-voltage ride through capability. The main objective of this work is to design an algorithm that would enable the system to control the initial overcurrents that appear in the generator during voltage sags, which can damage the RSC, without tripping it. As a difference with classical solutions, based on the installation of crowbar circuits, this operation mode permits to keep the inverter connected to the generator, something that would permit the injection of power to the grid during the fault, as the new grid codes demand. A theoretical study of the dynamical behavior of the rotor voltage is also developed, in order to show that the voltage at the rotor terminals required for the control strategy implementation remains under controllable limits. In order to validate the proposed control system simulation, results have been collected using PSCAD/EMTDC and experimental tests have been carried out in a scaled prototype.
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Papers by Alvaro Vicente