TESTING SIGNIFICANCE OF MULTI-DESTINATION AND MULTI-PURPOSE TRIP EFFECTS IN A TRAVEL COST METHOD DEMAND MODEL FOR WHALE WATCHING TRIPS

Inclusion of multi-destination and multi-purpose visitors has an appreciable influence on a standard count data travel cost model derived estimate of willingness to pay but the differences are not statistically significant. We adapt a more general travel cost model (TCM) of Parsons and Wilson (1997) that allows for inclusion of multi-destination visitors as incidental demand to allow estimation of an unbiased measure of single and multi-destination willingness to pat for whale viewing using a single pooled equation. The primary purpose trip values from the standard TCM and simple generalized TCM model are identical at $43 per person per day and neither are significantly different from the$50 day value from a generalized model that distinguishes between joint and incidental trips. The general models avoid underestimation of total recreation site benefits that would result from omitting the consumer surplus of multi-destination visitors.Resource /Energy Economics and Policy,

Range-wide patterns of geographic variation in songs of Golden-crowned Sparrows (\u3ci\u3eZonotrichia atricapilla\u3c/i\u3e)

Discrete geographic variation, or dialects, in songs of songbirds arise as a consequence of complex interactions between ecology and song learning. Four of the five species of Zonotrichia sparrows, including the model species White-crowned Sparrow (Z. leucophrys), have been studied with respect to the causes and consequences of geographic variation in song. Within White-crowned Sparrows, subspecies that migrate farther have larger range size of dialects. Here, we assessed geographic patterns of song variation in the fifth species of this genus, the Golden-crowned Sparrow (Z. atricapilla). We analyzed field-recorded songs from 2 sampling periods (1996–1998 and 2006–2013) covering most of its breeding range in western North America. All songs began with a descending whistle and most songs consisted of 3–4 phrases that contained combinations of whistles, buzzes, and trills. We identified 13 discrete song types based on unique sequences of phrase types and frequency changes between phrases. Over 90% of individuals sang 1 of 5 song types, and we found clear dialect structure composed of these 5 common song types. The geographic range of dialects spanned large distances (500 to 1,700 km), resembling the geographic structure of dialects in the long-distance migrant Gambel’s White-crowned Sparrow (Z. l. gambelli), though locations of dialect boundaries differ between species. Because both Golden-crowned Sparrows and Gambel’s White-crowned Sparrows migrate similarly long distances, our study provides support to the hypothesis that dialect range size correlates with migration distance. We found little evidence of change in dialect composition in 4 populations that were sampled 15 years apart, which suggests that the dialect structure is stable across multiple generations. Our study opens the door for further comparisons to investigate links between ecology and the emergence of song dialects in this well-studied genus

Range-wide patterns of geographic variation in songs of Golden-crowned Sparrows (\u3ci\u3eZonotrichia atricapilla\u3c/i\u3e)

Discrete geographic variation, or dialects, in songs of songbirds arise as a consequence of complex interactions between ecology and song learning. Four of the five species of Zonotrichia sparrows, including the model species White-crowned Sparrow (Z. leucophrys), have been studied with respect to the causes and consequences of geographic variation in song. Within White-crowned Sparrows, subspecies that migrate farther have larger range size of dialects. Here, we assessedgeographic patterns of song variation in the fifth species of this genus, the Golden-crowned Sparrow (Z. atricapilla). We analyzed field-recorded songs from 2 sampling periods (1996–1998 and 2006–2013) covering most of its breeding range in western North America. All songs began with a descending whistle and most songs consisted of 3–4 phrases that contained combinations of whistles, buzzes, and trills. We identified 13 discrete song types based on unique sequences of phrase types and frequency changes between phrases. Over 90% of individuals sang 1 of 5 song types, and we found clear dialect structure composed of these 5 common song types. The geographic range of dialects spanned large distances (500 to 1,700 km), resembling the geographic structure of dialects in the long-distance migrant Gambel’s White-crowned Sparrow (Z. l. gambelli), though locations of dialect boundaries differ between species. Because both Golden-crowned Sparrows and Gambel’s White-crowned Sparrows migrate similarly long distances, our study provides support to the hypothesis that dialect range size correlates with migration distance. We found little evidence of change in dialect composition in 4 populations that were sampled 15 years apart, which suggests that the dialect structure is stable across multiple generations. Our study opens the door for further comparisons to investigate links between ecology and the emergence of song dialects in this well-studied genus. La variación geográfica discreta, o los dialectos, en los cantos de las aves canoras se originan como consecuencia de interacciones complejas entre la ecología y el aprendizaje de los cantos. Cuatro de las 5 especies de Zonotrichia, incluyendo la especie modelo Z. leucophrys, han sido estudiadas con respecto a las causas y consecuencias de la variación geográfica en el canto. Al interior de la especie Z. leucophrys, las subespecies que migran más lejos tienen dialectos con rangos más amplios. En este trabajo evaluamos los patrones de variación del canto en la quinta especie de este género, Z. atricapilla. Analizamos cantos grabados en el campo de dos períodos de muestreo (1996–1998 y 2006–2013), cubriendo la mayor parte de su rango reproductivo en el oeste de América del Norte. Todos los cantos comienzan con un silbido descendente y la mayoría de los cantos consistieron en 3–4 frases con combinaciones de silbidos, zumbidos y trinos. Identificamos 13 tipos discretos de cantos basados en secuencias únicas de tipos de frases y en cambios de frecuencia entre frases. Más del 90% de los individuos cantaron uno de los 5 tipos de cantos, y encontramos una clara estructura del dialecto compuesta por estos 5 tipos de cantos comunes. El rango geogra´fico de los dialectos abarcó grandes distancias (500 a 1,700 km), asemeja´ndose a la estructura geográfica de los dialectos de la especie migratoria de larga distancia Z. l. gambelli, aunque las localidades de frontera de los dialectos difirieron entre especies. Debido a que Z. atricapilla y Z. l. gambelli migran ambas largas distancias, nuestro estudio apoya la hipótesis de que el tamaño del rango del dialecto se correlaciona con la distancia de migración. Encontramos poca evidencia de cambios en la composición del dialecto en cuatro poblaciones que fueron muestreadas con una diferencia de 15 años, lo que sugiere que la estructura del dialecto es estable a través de varias generaciones. Nuestro estudio abre la puerta a comparaciones adicionales para investigar los vínculos entre la ecología y la emergencia de dialectos del canto en este género bien estudiado

Range-wide patterns of geographic variation in songs of Golden-crowned Sparrows (Zonotrichia atricapilla)

Discrete geographic variation, or dialects, in songs of songbirds arise as a consequence of complex interactions between ecology and song learning. Four of the five species of Zonotrichia sparrows, including the model species White-crowned Sparrow (Z. leucophrys), have been studied with respect to the causes and consequences of geographic variation in song. Within White-crowned Sparrows, subspecies that migrate farther have larger range size of dialects. Here, we assessed geographic patterns of song variation in the fifth species of this genus, the Golden-crowned Sparrow (Z. atricapilla). We analyzed field-recorded songs from 2 sampling periods (1996–1998 and 2006–2013) covering most of its breeding range in western North America. All songs began with a descending whistle and most songs consisted of 3–4 phrases that contained combinations of whistles, buzzes, and trills. We identified 13 discrete song types based on unique sequences of phrase types and frequency changes between phrases. Over 90% of individuals sang 1 of 5 song types, and we found clear dialect structure composed of these 5 common song types. The geographic range of dialects spanned large distances (500 to 1,700 km), resembling the geographic structure of dialects in the long-distance migrant Gambel’s White-crowned Sparrow (Z. l. gambelli), though locations of dialect boundaries differ between species. Because both Golden-crowned Sparrows and Gambel’s White-crowned Sparrows migrate similarly long distances, our study provides support to the hypothesis that dialect range size correlates with migration distance. We found little evidence of change in dialect composition in 4 populations that were sampled 15 years apart, which suggests that the dialect structure is stable across multiple generations. Our study opens the door for further comparisons to investigate links between ecology and the emergence of song dialects in this well-studied genus

De-leptonization and Non-Axisymmetric Instabilities in Core Collapse Supernovae

The timescale of de-leptonization by neutrino loss and associated contraction of a proto-neutron star is short compared to the time to progagate a shock through the helium core of a massive star, and so the de-leptonization phase does not occur in the vacuum of space, but within the supernova ambiance whether or not there has been a successful explosion. Dynamical non-axisymmetric instabilities (NAXI) are predicted for sufficiently strongly differentially rotating proto-neutron stars. Some modes are unstable for small values of the ratio of rotational kinetic energy to binding energy, T/|W| > 0.01. The NAXI are likely to drive magnetoacoustic waves into the surrounding time-dependent density structure. These waves represent a mechanism of the dissipation of the free energy of differential rotation of the proto-neutron star, and the outward deposition of this energy may play a role in the supernova explosion process. We estimate the power produced by this process and the associated timescale and discuss the possible systematics of the de-leptonization phase in this context. A likely possibility is that the proto-neutron star will spin down through these effects before de-leptonization and produce substantial but not excessive energy input.Comment: 15 pages, 1 figure, accepted for publication in the Astrophysical Journa

Sevoflurane induces cardioprotection through reactive oxygen species-mediated upregulation of autophagy in isolated guinea pig hearts.

PURPOSE: Sevoflurane increases reactive oxygen species (ROS), which mediate cardioprotection against myocardial ischemia-reperfusion injury. Emerging evidence suggests that autophagy is involved in cardioprotection. We examined whether reactive oxygen species mediate sevoflurane preconditioning through autophagy. METHODS: Isolated guinea pigs hearts were subjected to 30 min ischemia followed by 120 min reperfusion (control). Anesthetic preconditioning was elicited with 2 % sevoflurane for 10 min before ischemia (SEVO). The ROS-scavenger, N-(2-mercaptopropionyl) glycine (MPG, 1 mmol/l), was administered starting 30 min before ischemia to sevoflurane-treated (SEVO + MPG) or non-sevoflurane-treated (MPG) hearts. Infarct size was determined by triphenyltetrazolium chloride stain. Tissue samples were obtained after reperfusion to determine autophagy-related protein (microtubule-associated protein light chain I and II: LC3-I, -II) and 5\u27 AMP-activated protein kinase (AMPK) expression using Western blot analysis. Electron microscopy was used to detect autophagosomes. RESULTS: Infarct size was significantly reduced and there were more abundant autophagosomes in SEVO compared with control. Western blot analysis revealed that the ratio of LC3-II/I and phosphorylation of AMPK were significantly increased in SEVO. These effects were abolished by MPG. CONCLUSIONS: Sevoflurane induces cardioprotection through ROS-mediated upregulation of autophagy

The Magnetorotational Instability in Core Collapse Supernova Explosions

We investigate the action of the magnetorotational instability (MRI) in the context of iron-core collapse. Exponential growth of the field on the rotation time scale by the MRI will dominate the linear growth process of field line "wrapping" with the same characteristic time. We examine a variety of initial rotation states, with solid body rotation or a gradient in rotational velocity, that correspond to models in the literature. A relatively modest value of the initial rotation, a period of ~ 10 s, will give a very rapidly rotating PNS and hence strong differential rotation with respect to the infalling matter. We assume conservation of angular momentum on spherical shells. Results are discussed for two examples of saturation fields, a fiducial field that corresponds to Alfven velocity = rotational velocity and a field that corresponds to the maximum growing mode of the MRI. Modest initial rotation velocities of the iron core result in sub-Keplerian rotation and a sub-equipartition magnetic field that nevertheless produce substantial MHD luminosity and hoop stresses: saturation fields of order 10^{15} - 10^{16} G develop within 300 msec after bounce with an associated MHD luminosity of about 10^{52} erg/s. Bi-polar flows driven by this MHD power can affect or even cause the explosions associated with core-collapse supernovae.Comment: 42 pages, including 15 figures. Accepted for publication in ApJ. We have revised to include an improved treatment of the convection, and some figures have been update

Combination of necroptosis and apoptosis inhibition enhances cardioprotection against myocardial ischemia-reperfusion injury.

PURPOSE: Necroptosis has been proposed as a mode of cell death that is a caspase-independent programmed necrosis. We investigated whether necroptosis is involved in myocardial ischemia-reperfusion injury in isolated guinea pig hearts and, if so, whether simultaneous inhibition of necroptosis and apoptosis confers enhanced cardioprotection. METHODS: Isolated perfused guinea pig hearts were subjected to 30 min ischemia and 4 h reperfusion (control = CTL, n = 8). Necrostatin-1 (necroptosis inhibitor, 10 μM), Z-VAD (apoptosis inhibitor, 0.1 μM) and both inhibitors were administered starting 5 min before ischemia and during the initial 30 min of reperfusion (Nec, Z-VAD, Nec + Z-VAD; n = 8 each). Contractile recovery was monitored by left ventricular developed (LVDP) and end-diastolic (LVEDP) pressure. Infarct size was determined by triphenyltetrazolium chloride staining. Tissue samples were obtained after 4 h reperfusion to determine expression of receptor-interacting protein 1 (RIP1) and activated caspase 3 by Western blot analysis. RESULTS: After reperfusion, Nec + Z-VAD had higher LVDP and lower LVEDP compared with CTL. Infarct size was reduced in Nec and Z-VAD compared with CTL. Combination of necroptosis and apoptosis inhibition further reduced infarct size. Expression of activated caspase 3 was not increased in Z-VAD and Nec + Z-VAD compared with Nec and CTL. Expression of RIP1 was preserved in Z-VAD and Nec + Z-VAD compared with CTL, suggesting RIP1-mediated necrosis is involved in myocardial ischemia-reperfusion injury. CONCLUSION: Necroptosis is involved in myocardial ischemia-reperfusion injury, and simultaneous inhibition of necroptosis and apoptosis enhances the cardioprotective effect. These findings may provide a novel, additive strategy for cardioprotection in acute myocardial infarction