Stellar Equilibrium in 2+1 Dimensions

The hydrostatic equilibrium of a $2+1$ dimensional perfect fluid star in asymptotically anti-de Sitter space is discussed. The interior geometry matches the exterior $2+1$ black-hole solution. An upper mass limit is found, analogous to Buchdahl's theorem in 3+1, and the possibility of collapse is discussed. The case of a uniform matter density is solved exactly and a new interior solution is presented.Comment: 11 pages, revtex, no figure

The Dirichlet Problem for Curvature Equations in Riemannian Manifolds

We prove the existence of classical solutions to the Dirichlet problem for a class of fully nonlinear elliptic equations of curvature type on Riemannian manifolds. We also derive new second derivative boundary estimates which allows us to extend some of the existence theorems of Caffarelli, Nirenberg and Spruck [4] and Ivochkina, Trundinger and Lin [19] to more general curvature functions and less convex domains.Comment: 32 pages, no figures. Final version. Paper accepted to publication in Indiana University Mathematics Journa

Internet of Things and Their Coming Perspectives: A Real Options Approach

Internet of things is developing at a dizzying rate, and companies are forced to implement it in order to maintain their operational efficiency. The high flexibility inherent to these technologies makes it necessary to apply an appropriate measure, which properly assesses risks and rewards. Real options methodology is available as a tool which fits the conditions, both economic and strategic, under which investment in internet of things technologies is developed. The contribution of this paper is twofold. On the one hand, it offers an adequate tool to assess the strategic value of investment in internet of things technologies. On the other hand, it tries to raise awareness among managers of internet of things technologies because of their potential to contribute to economic and social progress. The results of the research described in this paper highlight the importance of taking action as quickly as possible if companies want to obtain the best possible performance. In order to enhance the understanding of internet of things technologies investment, this paper provides a methodology to assess the implementation of internet of things technologies by using the real options approach; in particular, the option to expand has been proposed for use in the decision-making process

Using Formative Research and Audience-Centric Intelligence to Develop the #JustBe Digital Magazine: An mHealth Strategy to Improve Adolescent Sexual Health

Digital strategies may help to overcome challenges in providing contraception education to overlooked and key sub-populations (older teens, ethnic minority youth, LGBTQ youth, high school dropouts and males). However, many current digital strategies are not culturally specific and often have limited information on the most effective contraceptive methods. In this article, we describe the preliminary steps used to develop #JustBe, a user-centered digital strategy for ethnic minority older youth and young adults with a specific focus contraception, sexual health, consent, and healthy relationships. Technology-based strategies such as #JustBe offer advantages over traditional face-to-face methods by utilizing a confidential way to retrieve sexual health information that may be sensitive and potentially embarrassing. Questions still remain regarding the feasibility and long-term effects of mobile health interventions for contraception use

El patrimonio del comercio valenciano del frío

El comercio del frío natural adquirió una gran importancia en el País Valenciano entre los siglos XVII y XIX. El artículo plantea algunas claves para su interpretación histórica y cultural. Presenta la red de depósitos de nieve (neveras y ventisqueros) y las actuaciones que se han desarrollado para conservar y revalorizar este singular patrimonio. (A

Warehouse Storing and Collecting of Parts

This report deals with reducing the high costs resulting from the wear and tear of the fork-lifts used to store or collect items in a warehouse. Two problems were identified and addressed separately. One concerns the way items should be stored or collected at storage locations on the shelves of one corridor. The other problem seeks for an efficient way to define which fork-lift should operate on each corridor, and the order by which the fork-lifts should visit the corridors. We give to both problems formulations that fit in the framework of combinatorial optimization

The last instar larva and pupa of Ora depressa (Coleoptera: Scirtidae), a marsh beetle with underwater pupation

In this contribution we describe and illustrate for the first time, detailed morphology and chaetotaxy of the last instar larva and the pupa of Ora depressa (Fabricius, 1801), and provide diagnostic characters and information on its biology. The last instar larva of O. depressa exhibits the characters traditionally recognized as diagnostic of the genus, i.e. the tip of the mandible obtuse, and the fourth maxillary palpomere long, almost as long as third palpomere. Ora depressa is characterized by a broadly elliptical body, which is widest at the metanotum, being brownish testaceous in color with several brown spots, having the dorsal surface mostly covered with numerous grooved scale-like setae and also several ungrooved scale-like setae, hair-like setae, club-like setae and pore-like sensilla distributed in a specific pattern, and the femur and tibiotarsus bearing a row of natatorial setae. The last instar larva of Ora depressa can be distinguished from those of the other known species of the genus by lobes of clypeolabrum being as long as wide and socket bristles with 2–6 inner teeth. The pupa of O. depressa differs from those of the other known species of the genus in the absence of pronotal horns and by the place where pupation occurs. Ora depressa pupates underwater, hanging from water’s surface with the aid of the laterally expanded pronotum which bears hydrophobic setation along the lateral margins.Fil: Libonatti, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Jorge, Gabrielle. Ministério da Ciência, Tecnologia, Inovações. Instituto Nacional de Pesquisas da Amazônia; BrasilFil: Archangelsky, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Departamento de Biología. Laboratorio de Investigaciones en Ecología y Sistemática Animal; ArgentinaFil: Michat, Mariano Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin