Summer diet comparison between the American Kestrel (<i>Falco sparverius</i></i>) and Aplomado Falcon (<i>Falco femoralis) in an agricultural area of Araucanía, southern Chile

La dieta del Halconcito Colorado (<i>Falco sparverius</i>) y del Halcón Plomizo (<i>Falco femoralis</i>) fue cuantificada a partir de regurgitados durante el verano de 1997-1998 en un área agrícola de la región de la Araucanía, sur de Chile. Numéricamente, las presas más importantes del Halconcito Colorado fueron los insectos (61% del total de presas), seguidos de aves (23%), roedores (13.7%) y reptiles (2.6%). Las aves tuvieron el mayor aporte de biomasa (79.6%), seguidas por los roedores (18%). La contribución de biomasa de insectos y reptiles fue insignificante. Las principales presas del Halcón Plomizo fueron las aves, tanto en número (89%) como en biomasa (99%). La contribución numérica y de biomasa de roedores e insectos fue mínima. La superposición trófica entre ambos halcones fue relativamente baja. Las dos especies parecieron consumir de manera oportunista a la especie de ave más abundante en el campo (Sicalis luteola), aunque el Halcón Plomizo podría estar consumiendo preferentemente a las aves presa de mayor tamaño.The diet of the American Kestrel (<i>Falco sparverius</i>) and Aplomado Falcon (<i>Falco femoralis</i>) was quantified by analysis of their pellets during the summer 1997-1998 in an agricultural area of Araucanía, southern Chile. By number, the most important prey of the American Kestrel were insects (61% of all individual prey) followed by birds (23%), rodents (13.7%) and reptiles (2.6%). Avian prey accounted for the highest biomass contribution (79.6%), followed by rodents (18%). Biomass contribution of insects and reptiles was negligible. Birds were the staple prey of the Aplomado Falcon both by number (89%) and biomass (99%). Number and biomass contribution of rodent and insect prey was minute. Diet of both raptor species did not broadly overlap. Both the American Kestrel and Aplomado Falcon appeared to respond in an opportunistic manner to the most abundant bird prey in the field (Sicalis luteola), although the latter species could be consuming preferentially larger-sized avian prey

Anchored FRET sensors detect local caspase activation prior to neuronal degeneration

<p>Abstract</p> <p>Background</p> <p>Recent studies indicate local caspase activation in dendrites or axons during development and in neurodegenerative disorders such as Alzheimer's disease (AD). Emerging evidences point to soluble oligomeric amyloid-β peptide as a causative agent in AD.</p> <p>Results</p> <p>Here we describe the design of fluorescence resonance energy transfer (FRET)-based caspase sensors, fused to the microtubule associated protein tau. Specific caspase sensors preferentially cleaved by caspase-3, -6 or -9 were expressed in differentiated human neuroblastoma SH-SY5Y cells. The anchoring of the sensors resulted in high FRET signals both in extended neurites and soma and made analysis of spatiotemporal signal propagation possible. Caspase activation was detected as loss of FRET after exposure to different stimuli. Interestingly, after staurosporine treatment caspase-6 activation was significantly delayed in neurites compared to cell bodies. In addition, we show that exposure to oligomer-enriched amyloid-β peptide resulted in loss of FRET in cells expressing sensors for caspase-3 and -6, but not -9, in both soma and neurites before neurite degeneration was observed.</p> <p>Conclusions</p> <p>Taken together, the results show that by using anchored FRET sensors it is possible to detect stimuli-dependent differential activation of caspases and to distinguish local from global caspase activation in live neuronal cells. Furthermore, in these cells oligomer-enriched amyloid-β peptide induces a global, rather than local activation of caspase-3 and -6, which subsequently leads to neuronal cell death.</p

Morphology and magnetic properties of W-capped Co nanoparticles

3 páginas, 3 figuras, 2 tablas.-- et al.Co–W nanoparticles formed by sequential sputtering of Co on amorphous alumina substrate and subsequent W capping are studied by high resolution and by scanning transmission electron microscopies, and by superconducting quantum interference device magnetometry. The analysis is focused on W nominal thickness dependence. Results suggest the formation of amorphous Co–W alloy nanoparticles, whose magnetic moment per Co atom is systematically reduced as the nominal thickness of W capping layer increases. The Co–W nanoparticles show superparamagnetic behavior. The activation energy for moment reversal and the effective anisotropy are obtained.The financial support of MAT08/1077 is acknowledged. A. I. Figueroa acknowledges a JAE-Predoc grant.Peer reviewe

Indagar dibujando

The value of the drawing as an instrument to represent what is known, defined, existing, is enriched when considering its potential to investigate, to explore and reduce the uncertainty inherent in the design process. Addressing the drawing as an instrument of inquiry implies not focusing its approach on the representation, without removing that historical merit, still current and necessary. It is to consider that its instrumental value facilitates the creative process of design, makes it possible to "think drawing". Drawing as an instrument of inquiry has as its main objective to enhance the development of the ability to think spatially.El dibujo como instrumento que indaga lo no definido, no conocido, no existente: indaga las configuraciones formales auxiliándose de la geometría. Dibujo y geometría se entrelazan en el pensamiento del diseño. El valor del dibujo como instrumento para representar lo conocido, definido, existente, se enriquece cuando se considera su potencialidad para indagar, para explorar y disminuir la incertidumbre propia del proceso de diseño. Abordar el dibujo como instrumento de indagación implica no centrar su abordaje en la representación, sin quitarle ese merito histórico, aún vigente y necesario. Es considerar que su valor instrumental viabiliza el proceso creativo del diseño, posibilita "pensar dibujando". En de la asignatura "Gráfica Sistemática 2" de la carrera Diseño industrial, de la FAUD-UNSJ, se tiene el objetivo de abordar el dibujo sistemático como un instrumento de indagación, un instrumento para pensar problemas espaciales con el propósito de ir disminuyendo el nivel de incertidumbre propio de todo proceso de diseño. Presentamos la "Práctica Integrativa: Sombras proyectadas" realizada por los alumnos durante el desarrollo de la temática "Teoría de sombras". El desarrollo de la misma requiere: resolver problemas acerca de "luces y sombras" y explorar modos en que "luz y objeto" se integran en un elemento de diseño. El proceso de enseñanza - aprendizaje se basa en la consideración del dibujo sistemático, analógico / digital, como medio de conocimiento en la resolución de problemas. El dibujo como instrumento de indagación tiene como principal objetivo potenciar el desarrollo de la habilidad para pensar espacialmente.Facultad de Arquitectura y Urbanism

Psychological interventions to prevent the onset of depressive disorders: A meta-analysis of randomized controlled trials

Purpose: Depressive disorders are common and have a considerable impact on patients and societies. Several treatments are available, but their effects are modest and reduce the burden only to a limited extent. Preventing the onset of depressive disorders may be one option to further reduce the global disease burden. Methods: We conducted a meta-analysis of randomized controlled trials in participants without a diagnosis of depression at baseline, who were assigned to a preventive psychological intervention, or a care-as-usual, or comparable control group and in which incident cases of depression at follow-up were ascertained with a diagnostic interview. Results: Our systematic searches resulted in 50 trials (14,665 participants) with relatively high quality, in high risk groups of all ages. The psychological interventions were mostly based on cognitive behavioral interventions. One year after the preventive interventions, the relative risk of developing a depressive disorder was RR = 0.81 (95% CI: 0.72–0.91), indicating that those who had received the intervention had 19% less chance to develop a depressive disorder. Given the average control event rate of 30%, twenty-one people had to participate in the intervention to prevent one depressive disorder compared to people in the control conditions. Conclusions: Prevention is a promising approach to reduce the global disease burden of depression in addition to treatments

Supersymmetry of gravitational ground states

A class of black objects which are solutions of pure gravity with negative cosmological constant are classified through the mapping between the Killing spinors of the ground state and those of the transverse section. It is shown that these geometries must have transverse sections of constant curvature for spacetime dimensions d below seven. For d > 6, the transverse sections can also be Euclidean Einstein manifolds. In even dimensions, spacetimes with transverse section of nonconstant curvature exist only in d = 8 and 10. This classification goes beyond standard supergravity and the eleven dimensional case is analyzed. It is shown that if the transverse section has negative scalar curvature, only extended objects can have a supersymmetric ground state. In that case, some solutions are explicitly found whose ground state resembles a wormhole.Comment: 16 pages, CECS style, minor correction

Oceanographic Observations in Chilean Coastal Waters Between Valdivia and Concepcion

The physical oceanography of the biologically productive coastal waters of central Chile (36 degrees to 40 degrees S) is relatively unknown. In December 1998 we made a short exploratory cruise between Valdivia (40 degrees S) and Concepcion (37.8 degrees S) taking temperature, salinity, oxygen, and current velocity profiles. Coincident sea surface temperature and color measurements were obtained by satellite. The results showed an area dominated by wind-induced coastal upwelling, river runoff, intrusion of offshore eddies, mixing, and heating. Upwelling centers were found over the shelf at three locations: inshore of Mocha Island, off Valdivia, and off Lavapie Point. At these centers, equatorial subsurface water (ESSW) intrudes into the coastal waters, sometimes affecting the surface waters. Since ESSW has characteristically low-oxygen and high-salinity values, it is easily detected. Off Valdivia, runoff imparts stratification, while farther north, solar heating and reduced mixing may facilitate stratification. In some areas, even strong winds would not destroy the stratification imparted by the advection of buoyancy that occurs during the upwelling process. Strong equatorward currents (\u3e1 m s(-1)) in the form of an upwelling jet were found off Lavapie Point. This is also the location of an intruding anticyclone. Elsewhere, currents were mainly northward but highly variable because of intrusions from offshore eddies. The sea surface temperature and ocean color images show a complex field of onshore and offshore intrusions combined with the effects of mixing on chlorophyll concentrations. The residence time of upwelled water on the shelf is estimated to be less than 1 week

Aves asociadas al Aeropuerto Carriel Sur de Talcahuano, sur de Chile: evaluación de peligro aviario

Between the summer 2002 and 2005 was evaluated the richness and abundance of birds associated to the Carriel Sur Airport of Talcahuano and was estimated the collision risk representing each species for air navigation. Birds were counted in 10 count points distributed in different habitats around the landing runways. The collision risk was estimated by the Avian Hazard Index (AHI) which combines size, abundance and history of collisions of each species. During the study period 63 species were recorded, plus 10 aditional species were recorded after summer 2005. The most abundant species were the Grassland Yellow-Finch, Kelp Gull, Southern Lapwing Long-tailed Meadowlark (28%, 14%, 10%, 8% of all individual records). Excepting Kelp Gull, all remaining species exhibited seasonal cycles of abundance. The Kelp Gull showed multiyear outbreaks triggered. The species representing a higher collision risk for air navigation are the Kelp Gull (API = 36), Southern Lapwing (AHI = 24), South American Tern (AHI = 16), Black Vulture (AHI = 12), Neotropic Cormorant (AHI = 9) and Chimango Caracara (AHI = 8). However, the each species’ AHI varied temporally from very high to very low values according to changes in abundance. This study reflects the need for long-term assessments of changes in population size of bird species to better approximate the risk of bird-aircraft collisions.Entre el verano de 2002 y 2005 se evaluó la riqueza y abundancia de aves asociadas al Aeropuerto Carriel Sur de Talcahuano y se estimó el riesgo de colisión que representaría cada especie para la aeronavegación. Las aves fueron contabilizadas en 10 puntos de conteos distribuidos en distintos hábitats alrededor del las pistas de aterrizaje. El riesgo de colisión fue estimado mediante el índice de peligro aviario (IPA) el cual combina tamaño, abundancia e historial de colisiones de cada especie. Durante el periodo de estudio se registraron 63 especies, mas 10 especies que fueron registradas después del verano de 2005. Las especies más abundantes fueron el chirigüe, la gaviota dominicana, el queltehue y la loica (28%, 14%, 10%, 8% del total de registros individuales). Con excepción de la gaviota dominicana, todas las especies exhibieron ciclos estacionales de abundancia. La gaviota dominicana mostró irrupciones multianuales aparentemente por factores ambientales no bien determinados. Las especies que representarían un mayor riesgo de colisión para la aeronavegación son la gaviota dominicana (IPA = 36), el queltehue (IPA = 24), el gaviotín sudamericano (IPA = 16), el jote de cabeza negra (IPA = 12), el yeco (IPA = 9) y el tiuque (IPA = 8). Sin embargo, el IPA de cada especie varió temporalmente desde valores muy altos a valores muy bajos según los cambios de abundancia. Este estudio refleja la necesidad de evaluaciones de largo plazo de los cambios en el tamaño poblacional de especies de aves para una mejor aproximación del riesgo de colisiones aves-aeronaves

Endocardial Approach for Substrate Ablation in Brugada Syndrome

Radiofrequency ablation (RFA) in Brugada syndrome (BrS) has been performed by both endocardial and epicardial. The substrate in BrS is not completely understood. We investigate the functional endocardial substrate and its correlation with clinical, electrophysiological and ECG findings in order to guide an endocardial ablation. Two patients agreed to undergo an endocardial biopsy and the samples were examined with transmission electron microscopy (TEM) to investigate the correlation between functional and ultrastructural alterations. About 13 patients (38.7 ± 12.3 years old) with spontaneous type 1 ECG BrS pattern, inducible VF with programmed ventricular stimulation (PVS) and syncope without prodromes were enrolled. Before endocardial mapping, the patients underwent flecainide testing with the purpose of measuring the greatest ST-segment elevation for to be correlated with the size and location of substrate in the electro-anatomic map. Patients underwent endocardial bipolar and electro-anatomic mapping with the purpose of identify areas of abnormal electrograms (EGMs) as target for RFA and determine the location and size of the substrate. When the greatest ST-segment elevation was in the third intercostal space (ICS), the substrate was located upper in the longitudinal plane of the right ventricular outflow tract (RVOT) and a greatest ST-segment elevation in fourth ICS correspond with a location of substrate in lower region of longitudinal plane of RVOT. A QRS complex widening on its initial and final part, with prolonged transmural and regional depolarization time of RVOT corresponded to the substrate located in the anterior-lateral region of RVOT. A QRS complex widening rightwards and only prolonged transmural depolarization time corresponded with a substrate located in the anterior, anterior-septal or septal region of RVOT. RFA of endocardial substrate suppressed the inducibility and ECG BrS pattern during 34.7 ± 15.5 months. After RFA, flecainide testing confirmed elimination of the ECG BrS pattern. Endocardial biopsy showed a correlation between functional and ultrastructural alterations. Endocardial RFA can eliminate the BrS phenotype and inducibility during programmed ventricular stimulation (PVS)