Optimizacion estatica restringida en economia: metodos, algoritmos e implementacion en el general algebraic modeling system

The paper presents methods of linear and nonlinear mathematical programming and their computational implementation in the General Algebraic Modeling System (GAMS). It also presents economic examples and introduces a number of solution algorithms: simplex, gradient, Newton and penalties

Optimizacion estatica restringida en economia: metodos, algoritmos e implementacion en el general algebraic modeling system

The paper presents methods of linear and nonlinear mathematical programming and their computational implementation in the General Algebraic Modeling System (GAMS). It also presents economic examples and introduces a number of solution algorithms: simplex, gradient, Newton and penalties

Choosing the extent of private participation in public services: A computable general equilibrium perspective

What determines the propensity to reduce or widen the extent of public ownership? Why has there been a tendency to privatise and concede public utilities during the nineties? The answers to these questions depend both on macroeconomic and microeconomic considerations. And correct answers could also help to avoid or prevent inefficient reversals and frustrations that jeopardize reform processes. An alternative perspective, that combines micro and macro arguments, is given by general equilibrium models. The objective of this paper is to explore the rationality of the decision of choosing the implicit “technologies” of private and public operators of utilities in an economy that has fiscal budget and trade balance in equilibrium. The simulations confirm that the choice of the technology to be used for servicing infrastructure depends on deep parameters of efficiency and costs. The model shows that there are plausible scenarios where the selection is not unique

Dominulin A and B: two new antibacterial peptides identified on the cuticle and in the venom of the social paper wasp Polistes dominulus using MALDI-TOF, MALDI-TOF/TOF, and ESI-ion trap.

Two new antibacterial peptides, denominated as Dominulin A and B, have been found on the cuticle and in the venom of females of the social paper wasp Polistes dominulus. The amino acidic sequence of the two peptides, determined by mass spectrometry, is INWKKIAE VGGKIL SSL for Dominulin A (MW = 1854 Da) and INWKKIAEIGKQVL SAL (MW = 1909 Da) for Dominulin B. Their presence on the cuticle was confirmed using MALDI-TOF by means of micro-extractions and direct analyses on body parts. The presence in the venom and the primary structure of the dominulins suggest their classification in the mastoparans, a class of peptides found in the venom of other Aculeate hymenoptera. Their antimicrobial action against Gram+ and Gram− bacteria fits in the range of the best natural antimicrobial peptides. Dominulins can represent an important defense of the colony of Polistes dominulus against microbial pathogens

The Evolution of Invasiveness in Garden Ants

It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects

Biochar successfully replaces activated charcoal for in vitro culture of two white poplar clones reducing ethylene concentration

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Determinants of immature brood and nest recognition in a stenogastrine wasp (Hymenoptera Vespidae)

Parischnogaster mellyi is a common species of hover wasp which lives in the Oriental Region. In this research we wanted to achieve a deeper understanding of some aspects of its social biology and chemical ecology considering the composition of colonies, the reproductive potential of the female nest-mates, the chemical similarities between the adult cuticular hydrocarbons, the nest paper, the Dufour's gland secretion of the females and the pap placed on the eggs as a support for larval development. We were able to assess with nest exchange experiments that this species is capable of immature brood recognition. Neither the pap placed on eggs, nor the nest odour are used in this recognition process, despite the potential discrimination cues shown by chemical analyses

The trade balance effect of infrastructure services regulation

This paper addresses the relationship between the design of incentives to firms under regulation, mainly the rule for adjusting tariffs, and trade balance performance of the country. We also explore whether this relationship is relevant or not for a typical developing economy like Argentina. We find it is. To study these issues we perform comparative static numerical exercises using a CGE model where service obligation and no entry in regulated industries are assumed. We show that the capital account openness and the rate of exchange regime could be key elements to match with the regulatory regime. The potential inconsistency between the international trade regime and the regulatory regime should not be rejected a priori.Fil: Chisari, Omar Osvaldo. Universidad Argentina de la Empresa. Facultad de Ciencias Economicas. Instituto de Economia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Estache, Antonio. Universite Libre de Bruxelles; BélgicaFil: Lambardi, Germán D.. Universidad ICESI; ColombiaFil: Romero. Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias Economicas. Instituto de Economia; Argentin

Determinants of immature brood and nest recognition in a stenogastrine wasp (hymenoptera vespidae)

Parischnogaster mellyi is a common species of hover wasp which lives in the Oriental Region. In this research we wanted to achieve a deeper understanding of some aspects of its social biology and chemical ecology considering the composition of colonies, the reproductive potential of the female nest-mates, the chemical similarities between the adult cuticular hydrocarbons, the nest paper, the Dufour's gland secretion of the females and the pap placed on the eggs as a support for larval development. We were able to assess with nest exchange experiments that this species is capable of immature brood recognition. Neither the pap placed on eggs, nor the nest odour are used in this recognition process, despite the potential discrimination cues shown by chemical analyses