Long-term individual foraging site fidelity – why some gannets don’t change their spots

Many established models of animal foraging assume that individuals are ecologically equivalent. However, it is increasingly recognized that populations may comprise individuals who differ consistently in their diets and foraging behaviors. For example, recent studies have shown that individual foraging site fidelity (IFSF, when individuals consistently forage in only a small part of their population's home range) occurs in some colonial breeders. Short‐term IFSF could result from animals using a win–stay, lose–shift foraging strategy. Alternatively, it may be a consequence of individual specialization. Pelagic seabirds are colonial central‐place foragers, classically assumed to use flexible foraging strategies to target widely dispersed, spatiotemporally patchy prey. However, tracking has shown that IFSF occurs in many seabirds, although it is not known whether this persists across years. To test for long‐term IFSF and to examine alternative hypotheses concerning its cause, we repeatedly tracked 55 Northern Gannets (Morus bassanus) from a large colony in the North Sea within and across three successive breeding seasons. Gannets foraged in neritic waters, predictably structured by tidal mixing and thermal stratification, but subject to stochastic, wind‐induced overturning. Both within and across years, coarse to mesoscale (tens of kilometers) IFSF was significant but not absolute, and foraging birds departed the colony in individually consistent directions. Carbon stable isotope ratios in gannet blood tissues were repeatable within years and nitrogen ratios were also repeatable across years, suggesting long‐term individual dietary specialization. Individuals were also consistent across years in habitat use with respect to relative sea surface temperature and in some dive metrics, yet none of these factors accounted for IFSF. Moreover, at the scale of weeks, IFSF did not decay over time and the magnitude of IFSF across years was similar to that within years, suggesting that IFSF is not primarily the result of win–stay, lose–shift foraging. Rather, we hypothesize that site familiarity, accrued early in life, causes IFSF by canalizing subsequent foraging decisions. Evidence from this and other studies suggests that IFSF may be common in colonial central‐place foragers, with far‐reaching consequences for our attempts to understand and conserve these animals in a rapidly changing environment.

Roche tomography of cataclysmic variables - IV. Star-spots and slingshot prominences on BV Cen

We present Roche tomograms of the G5-G8 IV/V secondary star in the long-period cataclysmic variable BV Cen reconstructed from Magellan Inamori Kyocera Echelle spectrograph echelle data taken on the Magellan Clay 6.5-m telescope. The tomograms show the presence of a number of large, cool star-spots on BV Cen for the first time. In particular, we find a large high-latitude spot which is deflected from the rotational axis in the same direction as seen on the K3-K5 IV/V secondary star in the cataclysmic variable AE Aqr. BV Cen also shows a similar relative paucity of spots at latitudes between 40° and 50° when compared with AE Aqr. Furthermore, we find evidence for an increased spot coverage around longitudes facing the white dwarf which supports models invoking star-spots at the L1 point to explain the low states observed in some cataclysmic variables. In total, we estimate that some 25 per cent of the Northern hemisphere of BV Cen is spotted. We also find evidence for a faint, narrow, transient emission line with characteristics reminiscent of the peculiar low-velocity emission features observed in some outbursting dwarf novae. We interpret this feature as a slingshot prominence from the secondary star and derive a maximum source size of 75000 km and a minimum altitude of 160000 km above the orbital plane for the prominence. The entropy landscape technique was applied to determine the system parameters of BV Cen. We find M1 = 1.18 +/-0.280.16Msolar and M2 = 1.05 +/-0.230.14Msolar and an orbital inclination of i = 53° +/- 4° at an optimal systemic velocity of ? = -22.3 km s-1. Finally, we also report on the previously unknown binarity of the G5IV star HD 220492.

Roche tomography of cataclysmic variables - III. Star-spots on AE Aqr

We present a Roche tomography reconstruction of the secondary star in the cataclysmic variable AE Aqr. The tomogram reveals several surface inhomogeneities that are due to the presence of large, cool star-spots. In addition to a number of lower latitude spots, the maps also show the presence of a large, high-latitude spot similar to that seen in Doppler images of rapidly rotating isolated stars, and a relative paucity of spots at a latitude of 40 degrees. In total, we estimate that some 18 per cent of the Northern hemisphere of AE Aqr is spotted.

The effect of star-spots on eclipse timings of binary stars

We investigate the effects that star-spots have on the light curves of eclipsing binaries, and in particular how they may affect the accurate measurement of eclipse timings. Concentrating on systems containing a low-mass main-sequence star and a white dwarf, we find that if star-spots exhibit the Wilson depression they can alter the times of primary eclipse ingress and egress by several seconds for typical binary parameters and star-spot depressions. In addition, we find that the effect on the eclipse ingress/egress times becomes more profound for lower orbital inclinations. We show how it is possible, in principle, to determine estimates of both the binary inclination and the depth of the Wilson depression from light curve analysis.

A simple bioanalytical method for the quantification of antiepileptic drugs in dried blood spots

An increasing number of publications on the dried blood spot (DBS) sampling approach for the quantification of drugs and metabolites have been spurred on by the inherent advantages of this sampling technique. In the present research, a selective and sensitive high-performance liquid chromatography method for the concurrent determination of multiple antiepileptic drugs (AEDs) [levetiracetam (LVT), lamotrigine (LTG), phenobarbital (PHB)], carbamazepine (CBZ) and its active metabolite carbamazepine-10,11 epoxide (CBZE)] in a single DBS has been developed and validated. Whole blood was spotted onto Guthrie cards and dried. Using a standard punch (6. mm diameter), a circular disc was punched from the card and extracted with methanol: acetonitrile (3:1, v/v) containing hexobarbital (Internal Standard) and sonicated prior to evaporation. The extract was then dissolved in water and vortex mixed before undergoing solid phase extraction using HLB cartridges. Chromatographic separation of the AEDs was achieved using Waters XBridge™ C18 column with a gradient system. The developed method was linear over the concentration ranges studied with r=0.995 for all compounds. The lower limits of quantification (LLOQs) were 2, 1, 2, 0.5 and 1. µg/mL for LVT, LTG, PHB, CBZE and CBZ, respectively. Accuracy (%RE) and precision (%CV) values for within and between day were

Efecto de los spots políticos en la intención de voto. Análisis del papel de los encuadres y las funciones discursivas.

Tesis (Doctor en Filosofía con Acentuación en Ciencias Políticas) UANL, 2013.

Los spots políticos en la televisión y su impacto en la participación política de los jóvenes universitarios.

Tesis (Doctor en Filosofía con orientación en Ciencias Políticas) UANL, 2014.

Los Hot Spots: ¿Una alternativa para reducir los niveles de delincuencia en Bogotá?

El interés de esta monografía es analizar la incidencia de la estrategia de seguridad ciudadana de los Hot Spots en los niveles de delincuencia de Bogotá durante el periodo de la Alcaldía de Samuel Moreno 2009-2011, tomando como casos de estudio la Avenida 19 y la Zona Rosa (Chicó El Lago). Esta investigación se realiza desde los conceptos teórico-prácticos que ha arrojado el modelo de Hot Spot tras su aplicación en 18 ciudades del mundo, y que sirven como herramienta para analizar las transformaciones del delito en las zonas de estudio. De esta manera se avanza hacia el resultado que permite identificar los factores que impidieron que el modelo de Hot Spots se formulara y ejecutara efectivamente y por lo tanto no disminuyera los niveles de delincuencia en Bogotá.

Los spots audiovisuales en la campaña electoral de Horacio Serpa en las elecciones presidenciales de 2002 en Colombia y su incidencia sobre la favorabilidad de imagen del candidato

El presente trabajo se propone demostrar que la publicidad política audiovisual utilizada por la campaña de Horacio Serpa no alcanzó a generar el efecto positivo necesario para posicionar favorablemente su imagen frente a los electores, ya que los temas tratados por sus spots audiovisuales no lograron sintonizarse con la agenda pública. Para efectos de esta investigación, y por motivos de acceso a la información, en una parte del estudio la favorabilidad de imagen del candidato será analizada en función de su relación con la intención de voto de los ciudadanos.

Ambiente, figura y actio de las mujeres en los spots del siglo xx.

Resumen tomado de la publicación

Características de los spots con contenido deportivo en las cadenas televisivas españolas.

Resumen tomado de la publicación

Spots and other lumps and bumps.

Adecuado para lectura independiente o compartida, y enlaces curriculares. Se adapta a los diferentes tipos de textos requeridos por la Estrategia Nacional de Lectura. Este trabajo da detalles sobre espinillas, granos, acné, alergias y picaduras, manchas que crecen, la varicela, el sarampión, la viruela y la peste negra. También hay una resumida historia de la vacunación. Tiene glosario.