The financial crisis impact on the composition of an optimal portfolio in the stock market: study applied to portuguese index PSI 20

In order to maximize their utility function, investors select some assets over others, choosing the portfolio that will allow them to maximize their wealth. Each asset is chosen considering the relationship between the risk of that particular investment (usually measured by variance) - and the profitability it can offer, as well as the risk between this and other assets (measured by covariance). The purpose of this study consisted of constructing the minimum variance portfolio, using data from the PSI-20 (2008-2016) representative asset quotation, where investors are risk reluctant and wish to minimize risk while maintaining the same level of profitability, or on the other hand, maintaining the same level of risk but maximizing expected profit. In order to do this, a comparison of the optimal portfolio in 2004-2017 was carried out, compared to the minimum variance portfolio after the financial crisis (2008-2016). The method used to estimate each asset’s expected profitability that makes up the PSI-20 consists of extracting the obtained historical quotations. The optimal portfolio composition, in the period after the financial crisis, shows that the energy sector has an optimal portfolio weight reduction of 39.15%, that the big distribution sector (23.85%) was introduced into the portfolio and by last, the industrial sector stands its ground in the composition of the optimal portfolio.info:eu-repo/semantics/publishedVersio

A experiência brasileira de controlo da multidroga-resistência

AbstractIn this article the author reviews the evolution of the approach to multidrug-resistant tuberculosis (MDR-TB) in Brazil following the introduction of rifampicin associated to isoniazid and pyrazinamide (RHZ). It shows Brazil was one of the world’s first countries to use the RHZ regimen within a treatment system, with a first line regimen, another one specific for meningo-encephalic forms, for re-treatment of recurrences or of patients who returned with active tuberculosis after abandoning treatment, and a reserve regimen. The system was applied nationwide with guaranteed cost-free provision of medication, and self-administered. The author evaluates the growth of drug resistance, the emergence of multidrug-resistance and how management of this form of the disease has been organised

The Financial Crisis Impact on the Composition of an Optimal Portfolio in the Stock Market - Study Applied to Portuguese Index PSI 20

In order to maximize their utility function, investors select some assets over others, choosing the portfolio that will allow them to maximize their wealth. Each asset is chosen considering the relationship between the risk of that particular investment (usually measured by variance) - and the profitability it can offer, as well as the risk between this and other assets (measured by covariance). The purpose of this study consisted of constructing the minimum variance portfolio, using data from the PSI-20 (2008-2016) representative asset quotation, where investors are risk reluctant and wish to minimize risk while maintaining the same level of profitability, or on the other hand, maintaining the same level of risk but maximizing expected profit. In order to do this, a comparison of the optimal portfolio in 2004-2017 was carried out, compared to the minimum variance portfolio after the financial crisis (2008-2016). The method used to estimate each asset’s expected profitability that makes up the PSI-20 consists of extracting the obtained historical quotations. The optimal portfolio composition, in the period after the financial crisis, shows that the energy sector has an optimal portfolio weight reduction of 39.15%, that the big distribution sector (23.85%) was introduced into the portfolio and by last, the industrial sector stands its ground in the composition of the optimal portfolio.info:eu-repo/semantics/publishedVersio

A new species of Xylocopa (Nanoxylocopa) from Brazil (Hymenoptera, Apidae)

Xylocopa bella sp. nov., the second known species of the subgenus Xylocopa (Nanoxylocopa) Hurd & Moure, is newly described from the Espinhaço mountain range, in the state of Minas Gerais, and the Chapada Diamantina, in the state of Bahia, in eastern Brazil. It differs from X. ciliata Burmeister, the type species of X. (Nanoxylocopa), mainly by the possession, by females, of pale hairs intermixed with the black pubescence on the head and metasoma, the more abundant pubescence on mesoscutum and the much denser tergal pilosity, and the possession, by the male, of weakly infumated wing membrane, entirely dark scape, a patch of finely plumose pubescence on the anterior corners of the mesoscutum, narrower face, and shorter distance between the lateral ocellus and the eye. Additionally, X. ciliata, previously known from Argentina, Uruguay, Paraguay and southern Brazil, is newly recorded from the state of Minas Gerais

Mixed integer programming formulations and heuristics for joint production and transportation problems.

In this thesis we consider different joint production and transportation problems. We first study the simplest two-level problem, the uncapacitated two-level production-in-series lot-sizing problem (2L-S/LS-U). We give a new polynomial dynamic programming algorithm and a new compact extended formulation for the problem and for an extension with sales. Some computational tests are performed comparing several reformulations on a NP-Hard problem containing the 2L-S/LS-U as a relaxation. We also investigate the one-warehouse multi-retailer problem (OWMR), another NP-Hard extension of the 2L-S/LS-U. We study possible ways to tackle the problem effectively using mixed integer programming (MIP) techniques. We analyze the projection of a multi-commodity reformulation onto the space of the original variables for two special cases and characterize valid inequalities for the 2L-S/LS-U. Limited computational experiments are performed to compare several approaches. We then analyze a more general two-level production and transportation problem with multiple production sites. Relaxations for the problem for which reformulations are known are identified in order to improve the linear relaxation bounds. We show that some uncapacitated instances of the basic problem of reasonable size can often be solved to optimality. We also show that a hybrid MIP heuristic based on two different MIP formulations permits us to find solutions guaranteed to be within 10% of optimality for harder instances with limited transportation capacity and/or with additional sales. For instances with big bucket production or aggregate storage capacity constraints the gaps can be larger. In addition, we study a different type of production and transportation problem in which cllients place orders with different sizes and delivery dates and the transportation is performed by a third company. We develop a MIP formulation and an algorithm with a local search procedure that allows us to solve large instances effectively.

Propuesta de adecuación de la pista de aterrizaje y mejora de los servicios del Aeropuerto de Medina en Cundinamarca

Trabajo de investigaciónEl contenido del trabajo se basa en la investigación y el diseño de la pista del aeropuerto en medina Cundinamarca la cual incluye el presupuesto, también se incorporan diseños básicos de terminal para pasajeros áreas administrativas, cuartel de bomberos, campos de vuelos así como un estudio socioeconómico del sector en cual se plasma la viabilidad del proyecto realizado.INTRODUCCIÓN 1. GENERALIDADES 2. MARCOS DE REFERENCIA 3. METODOLOGÍA 4.RESULTADOS 5. ANÁLISIS DE RESULTADOS E IMPACTOS 6. CONCLUSIONES 113 7. NUEVAS ÁREAS DE ESTUDIO 8. BIBLIOGRAFIAEspecializaciónEspecialista en Gerencia de Obras Civile

“WANTED DEAD OR ALIVE:” BLACK VULTURES (CORAGYPS ATRATUS) FEEDING ON A LIVE CAPYBARA (HYDROCHOERUS HYDROCHAERIS)

Abstract ∙ Although vultures are scavengers that feed mainly carcasses, they occasionally may feed on living tissue of vulnerable vertebrates. In South America, most records of vulture attacks on live animals refer to newborns of domes‐ tic mammals. Here, we describe the behavior of a group of Black Vultures (Coragyps atratus) feeding on a live capybara (Hydrochoerus hydrochaeris). The capybara had low mobility, high alopecia, and showed injuries in its dorsal region. The vultures insistently pursued the capybara and pecked directly on its injuries to feed on live tissue. The capybara tried to shake‐off and bite the vultures and escaped from them by diving into the water. We suggest that the observed behaviors are compatible with an extreme case of semi‐parasitic cleaning behavior by vultures on a live wild mammal.Resumo ∙ “Procurado vivo ou morto”: Urubus‐de‐cabeça‐preta (Coragyps atratus) alimentando‐se de capivara viva (Hydrochoerus hydrochaeris) Os urubus são aves necrófagas que se alimentam principalmente de carcaças, mas ocasionalmente alimentam‐se de tecidos vivos de vertebrados vulneráveis. Na América do Sul, a maioria dos ataques de urubus a animais vivos tem como vítimas mamíferos domésticos recém‐nascidos. Neste trabalho descrevemos o comportamento de um grande grupo de Urubus‐de‐cabeça‐preta (Coragyps atratus) que bicavam e alimentavam‐se de tecidos vivos de uma capivara (Hydrochoerus hydrochaeris). A capivara apresentava mobilidade reduzida, com elevada alopecia e ferimentos na região dorsal de seu corpo. Os urubus perseguiram insistentemente a capivara e bicaram diretamente sobre suas feridas para alimentarem‐se de tecido vivo. A capivara sacudiu‐se e tentou morder os urubus e mergulhou em um reservatório para fugir das aves. Assim, concluímos que os comportamentos observados referem‐se a um caso extremo de semiparasitismo entre um grupo de urubus e um mamífero herbívoro silvestre