Optimal Control of Insect Populations

We consider some optimal control problems for systems governed by linear parabolic PDEs with local controls that can move along the domain region Ω of the plane. We prove the existence of optimal paths and also deduce the first order necessary optimality conditions, using the Dubovitskii–Milyutin’s formalism, which leads to an iterative algorithm of the fixed-point kind. This problem may be considered as a model for the control of a mosquito population existing in a given region by using moving insecticide spreading devices. In this situation, an optimal control is any trajectory or path that must follow such spreading device in order to reduce the population as much as possible with a reasonable not too expensive strategy. We illustrate our results by presenting some numerical experiments

Optimal network topologies for local search with congestion

The problem of searchability in decentralized complex networks is of great importance in computer science, economy and sociology. We present a formalism that is able to cope simultaneously with the problem of search and the congestion effects that arise when parallel searches are performed, and obtain expressions for the average search cost--written in terms of the search algorithm and the topological properties of the network--both in presence and abscence of congestion. This formalism is used to obtain optimal network structures for a system using a local search algorithm. It is found that only two classes of networks can be optimal: star-like configurations, when the number of parallel searches is small, and homogeneous-isotropic configurations, when the number of parallel searches is large.Comment: 4 pages. Final version accepted in PR

RRx-001 in Refractory Small-Cell Lung Carcinoma: A Case Report of a Partial Response after a Third Reintroduction of Platinum Doublets.

RRx-001 is a pan-active, systemically nontoxic epigenetic inhibitor under investigation in advanced non-small cell lung cancer, small-cell lung cancer and high-grade neuroendocrine tumors in a Phase II clinical trial entitled TRIPLE THREAT (NCT02489903), which reexposes patients to previously effective but refractory platinum doublets after treatment with RRx-001. The purpose of this case study is first to report a partial response to carboplatin and etoposide in a patient with small-cell lung cancer pretreated with RRx-001, indicating episensitization or resensitization by epigenetic mechanisms, and second to discuss the literature related to small-cell lung cancer and episensitization

Molecular Systematics of the Fishing Bat Myotis (Pizonyx) vivesi

Phylogenetic reconstructions based on molecular data have shown recurrent morphological convergence during evolution of the species-rich genus Myotis. Species or groups of species with similar feeding strategies have evolved independently several times to produce remarkable similarities in external morphology. In this context, we investigated the contentious phylogenetic position of 1 of the 2 piscivorous bat species, Myotis vivesi, which was not included in previous molecular studies. This bat, endemic to the coasts and islands of the Gulf of California, Mexico, was long classified in its own genus, Pizonyx, because of its distinctive morphology. To reconstruct its phylogenetic origins relative to other Myotis, we sequenced the mitochondrial cytochrome-b gene of 2 M. vivesi and related vespertilionids. These outgroups included Pipistrellus subflavus, a member of the subgenus Perimyotis, sometimes classified within the genus Myotis. Unexpectedly, all reconstructions placed M. vivesi within a strongly supported clade including all other typical neotropical and Nearctic Myotis. This molecular phylogeny supports an endemic radiation of New World Myotis. Other Myotis species with similar adaptations to gaffing prey from the water surface present no close phylogenetic relationships with M. vivesi, indicating that such adaptations are convergences. On the other hand, P. subflavus is genetically as distant from the genus Myotis as from other Pipistrellus species, suggesting that generic rank to Perimyotis is warrante

Social Preferences, Skill Segregation and Wage Dynamics

We study the earning structure and the equilibrium asignment of workers to firms in a model in which workers have social preferences, and skills are perfectly substitutable in production. Firms offer long-term contracts, and we allow for frictions in the labour market in the form of mobility costs. The model delivers specific predictions about the nature of worker flows, about the characteristic of workplace skill segregation, and about wage dispersion both within and cross firms. We shows that long-term contracts in the resence of social preferences associate within-firm wage dispersion with novel "internal labour market" features such as gradual promotions, productivity-unrelated wage increases, and downward wage flexibility. These three dynamic features lead to productivity-unrelated wage volatily within firms.Publicad

Prisoners Teaching ESL: A Learning Community among “Language Partners”

A program in which prisoners teach ESL classes, supported by volunteer teacher-trainers, is a learning community with immense and sometimes unforeseen value

Employment Expectations and Gross Flows by Type of Work Contract

There is growing interest in understanding firms’ temporary and permanent employment practices and how institutional changes shape them. Using data on Spanish establishments, we examine: (a) how employers adjust temporary and permanent job and worker flows to prior employment expectations, and (b) how the 1994 and 1997 labour reforms promoting permanent employment affected establishments’ employment practices. Generally, establishments’ prior employment expectations are realized through changes in all job and worker flows. However, establishments uniquely rely on temporary hires as a buffer to confront diminishing long-run employment expectations. None of the reforms significantly affected establishments’ net temporary or permanent employment flows.http://deepblue.lib.umich.edu/bitstream/2027.42/40032/3/wp646.pd

Acute myocardial infarction as first manifestation of primary antiphospholipid syndrome in a twenty-four years old patient

El síndrome antifosfolípido primario usualmente se manifiesta como trombosis venosa profunda, tromboembolismo pulmonar y como evento cerebrovascular en la circulación arterial. Se presenta el caso de un paciente joven previamente sano, con infarto agudo del miocardio como primera manifestación del síndrome antifosfolípido primario.Q4Presentación de casos135-139Primary antiphospholipid syndrome is usually manifested with deep venous thrombosis, pulmonary thromboembolism and arterial thrombosis, including cerebrovascular accidents. We report the case of a previously healthy young patient who suffered an acute myocardial infarction as the first manifestation of a primary antiphospholipid syndrome

Forward induction and entry deterrence: an experiment

The Dixit (Econ J 90:95–106, 1980) hypothesis that incumbents use investment in capacity to deter potential entrants has found little empirical support. Bagwell and Ramey (J Econ 27:660–680, 1996) propose a model where, in the unique game-theoretic prediction based on forward induction or iterated elimination of weakly-dominated strategies, the incumbent does not have the strategic advantage. We conduct an experiment with games inspired by these models. In the Dixit-style game, the incumbent monopolizes the market most of the time even without the investment in capacity. In our Bagwell-and-Ramey-style game, the incumbent also tends to keep the market, in contrast to the predictions of an entrant advantage. Nevertheless, we fin strong evidence that forward induction affects the behavior of most participants. The results of our games suggest that players perceive that the firs mover has an advantage without having to pre-commit capacity. In our Bagwell–Ramey game, evolution and learning do not drive out this perception. We back these claims with data analysis and a theoretical framework for dynamics.Publicad