How Air Transport Connects The World: A New Metric of Air Connectivity and Its Evolution Between 1990 And 2012

Scheduled air transport services connect airports throughout the world and thereby enable interaction on a global scale. By doing so, they spur globalization (Hummels, 2007) as well as social and economic development (Lakshmanan, 2011). In order to facilitate integration of regions into global value chains, planners, scholars and policymakers therefore need to understand as to how scheduled air transport services link a region to other markets. For this purpose, connectivity metrics have been developed, which measure the degree of connections between airports (Burghouwt, Redondi, 2013). In particular, the ‘connection quality-weighting’ approach (Veldhuis, 1997; Burghouwt, de Wit, 2005) has been used to compute the aggregate quality of all available connections at an airport with regard to their properties in quickly bridging distances. However, such a metric has neither been calibrated on the basis of observed passenger behavior nor been computed for the world’s airports across a multi-decade time series. This paper sets out to develop the first such metric and to discuss global airline network development between 1990 and 2012 from a connectivity perspective.Florian Allroggen gratefully acknowledges funding from the German Research Foundation under grant no.: AL 1814/1-1. Michael Wittman thanks the members of the MIT Airline Industry Consortium for financial support and helpful comments throughout the development of this paper

Male Sex Pheromone of the Parasitoid Wasp Urolepis rufipes Demonstrates Biosynthetic Switch Between Fatty Acid and Isoprenoid Metabolism Within the Nasonia Group

Sex pheromones play a crucial role in the mate finding process of insects. The information has to be encoded in a species specific manner to avoid fitness costs due to courtship by or even mismating with closely related species. Hence, sex pheromones normally diversify when new species evolve. Pheromones of closely related species typically vary in their chemical composition, but the compounds they use are often biosynthetically related. The biosynthetic pathways of insect pheromones are variations of conserved pathways that lead to primary and secondary metabolites. A switch from one pathway to another, particularly in species that use the same type of pheromone glands, is the exception. Here we use chemical analyses and behavioral bioassays to examine the male sex pheromone of the parasitoid wasp Urolepis rufipes. The genus Urolepis is most closely related to Nasonia and Trichomalopsis, forming the so-called "Nasonia group." All Nasonia species and T. sarcophagae, the only Trichomalopsis species studied so far, produce fatty acid-derived hydroxylactones in their rectal vesicle. The pheromones are deposited on the ground and other substrates and attract virgin females. We show that males of U. rufipes produce a sex pheromone in the same gland and use it in the same manner as the other species of the Nasonia group. Structure elucidation and stable isotope labeling experiments revealed, however, that the U. rufipes pheromone is 2,6-dimethyl-7-octene-1,6-diol, a monoterpenoid derived from the mevalonate pathway. This suggests a biosynthetic switch between the fatty acid and isoprenoid metabolism in the Nasonia group

Morichales, cananguchales y otros palmares inundables de Suramérica. Parte II: Colombia, Venezuela, Brasil, Perú, Bolivia, Paraguay, Uruguay y Argentina

El libro está dividido en cuatro partes. En la primera sección se incluye un análisis muy completo sobre el estado del conocimiento, uso y conservación de Mauritia flexuosa en Suramérica. En la segunda parte se consideran varios casos de estudio (11) sobre comunidades de plantas asociadas, demografía, polinizadores, aves y mamíferos relacionados, así como temas de manejo y ecoturismo en palmares de Mauritia flexuosa. La tercera sección incluye aportes de varios países sobre otros palmares, principalmente de Astrocaryum jauari, Butia odorata, B. paraguayensis, Copernicia alba, C. tectorum, Euterpe oleracea, Manicaria saccifera, Mauritiella aculeata y Roystonea oleracea. También se aporta información de 25 especies adicionales de palmas, incluyendo los usos, dinámica de poblaciones, biología reproductiva, florística de humedales asociados y conservación, entre otros aspectos. Por último, en la cuarta parte se dan las conclusiones y recomendaciones para la conservación de los palmares inundables en Suramérica.Bogotá, D. C

Dark Matter Science in the Era of LSST

Astrophysical observations currently provide the only robust, empirical measurements of dark matter. In the coming decade, astrophysical observations will guide other experimental efforts, while simultaneously probing unique regions of dark matter parameter space. This white paper summarizes astrophysical observations that can constrain the fundamental physics of dark matter in the era of LSST. We describe how astrophysical observations will inform our understanding of the fundamental properties of dark matter, such as particle mass, self-interaction strength, non-gravitational interactions with the Standard Model, and compact object abundances. Additionally, we highlight theoretical work and experimental/observational facilities that will complement LSST to strengthen our understanding of the fundamental characteristics of dark matter