Resumo A análise da estabilidade global tem se tornado cada vez mais importante no projeto de edifícios de concreto armado, sobretudo nos mais esbeltos, por serem mais sensíveis aos deslocamentos laterais. A perda de estabilidade é usualmente associada à intensidade dos efeitos de 2ª ordem e, nesse sentido, o coeficiente gama-z (γz) torna-se um importante parâmetro de avaliação deste problema. O objetivo deste trabalho é verificar a eficiência do γz como parâmetro de estabilidade global, tomando como base os fatores de carga de flambagem das estruturas e os respectivos modos críticos de instabilidade. Para esta finalidade, é realizada uma análise comparativa de diversas estruturas idealizadas, de onde obteve-se uma equação para o cálculo aproximado do fator de carga crítica em função do coeficiente γz. A validação dessa equação foi realizada por meio da análise numérica de modelos em Elementos Finitos de edifícios reais de concreto armado. Constatou-se que a equação proposta oferece resultados satisfatórios para um certo intervalo de γz.

Abstract Global stability analysis is becoming increasingly important in the design of reinforced concrete buildings, especially in the slender ones, due its sensitivity to lateral displacement. The loss of stability is usually associated with the intensity of the second order effects and, in that sense, the gamma-z (γz) coefficient is an important evaluation parameter for this problem. This work aims to verify the γz efficiency as a global stability parameter based on the buckling load factors of the structures and their respective critical buckling modes. To this purpose, a comparative analysis is performed in several idealized structures, from which an approximate equation for calculating the critical load factor based on the γz coefficient is obtained. This equation was verified by numerical analysis of Finite Elements Method models of real reinforced concrete buildings. It was concluded that the proposed equation presents satisfying results within a certain range of γz.

Las universidades son centros de producción de conocimiento y de desarrollo científico y tecnológico. Asimismo, una de sus responsabilidades es promover en la sociedad la preservación del medio que nos rodea. Investigadores en el área cosmética de la Universidad Central de Venezuela, preocupados por el medio ambiente y los consumidores, diseñaron una propuesta venezolana como guía para la estandarización y clasificación de los cosméticos ecológicos. Conociendo que las economías de América Latina y del Caribe dependen en su mayoría de la productividad de sus ecosistemas, esta guía contribuirá como una herramienta para el desarrollo sustentable en los países de la región. Para su elaboración, se tomó en consideración la situación actual de estos países. Igualmente, se tomó en cuenta los reglamentos establecidos por los organismos internacionales para la certificación de cosméticos ecológicos más empleados en Latinoamérica. Adicionalmente, se estableció comunicación directa con algunos organismos certificadores y se realizó una revisión bibliográfica de revistas cosméticas de reconocido prestigio. Al comparar los diferentes procedimientos de certificación, se encontraron coincidencias en cuanto al uso de las materias primas permitidas, materiales de empaque y requerimientos para las empresas fabricantes. Sin embargo, se observaron diferencias tanto para la clasificación del producto, basado en el contenido del mismo, así como en los requerimientos exigidos en el texto de la etiqueta. Esta guía podría contribuir con el diseño de una legislación venezolana en materia de productos ecológicos que desarrolle ventajas competitivas en el mercado y que permita alcanzar con éxito el comercio de integración regional.

The universities are centers for knowledge production and scientific and technological development. Therefore, one of their responsibilities is to encourage the society to preserve the environment. Cosmetic researchers at the Universidad Central de Venezuela, aware of the environment as well as the necessities of the consumers, designed a proposal Venezuelan Guide for the Standardization and Classification of Ecologic Cosmetics. Ever since the economies of Latin America and the Caribbean highly depend on the productivity of the ecosystems; this guide will represent a tool for sustainable development for the countries in the region. The guide was elaborated taking into consideration the current situation of those countries. The design of the guide takes into account the rules established by the international bodies on the certification of ecologic cosmetics - mostly used in the Latin American countries-. In addition, direct communications with certifying agencies as well as important cosmetic journals were used. As we compared the different certification procedures used by the agencies, we found consensus in matters of the using of raw materials, packing materials and the requirements for these cosmetic producers. Nevertheless, there was a discrepancy in the classification of ecologic products based on their contents, as well as the information required in the labeling of the products. This guide will help to design a Venezuelan legislation on ecologic cosmetic products that will develop advantages on the market in terms of competition and, at the same time, achieving the access of these products on the regional integration markets.

Estudou-se a associação entre polimorfismos de conformação de fita simples (SSCP) no gene do receptor do fator-I de crescimento semelhante à insulina (IGF-IR) e idade ao primeiro parto (IPP), intervalo entre partos (IEP), duração da lactação (DL) e produção de leite (PL), em 106 fêmeas puras por cruza da raça Holandesa. A reação em cadeia da polimerase (PCR) com oligonucleotídeos iniciadores específicos gerou um fragmento de 335pb. A freqüência genotípica da população para o polimorfismo foi 82,1% de indivíduos homozigotos para o alelo A e 17,9% de heterozigotos (AB). A freqüência do alelo A foi 0,91 e a do alelo B, 0,09. Não foi encontrada associação entre o polimorfismo estudado e as características IPP, IEP e PL. A característica DL foi positivamente associada (P<0,05) à ausência do alelo B. A lactação dos animais portadores do genótipo AA foi mais longa.

The association between single-strand conformation polymorphism (SSCP) in the gene of insulin-like growth factor-I receptor (IGF-IR) and age at first calving (AFC), calving interval (CI), lactation length (LL), and milk yield (MY) was studied using 106 graded Holstein females. The polimerase chain reaction (PCR) with specific initiating oligonucleotides, resulted an amplified fragment of 335pb. The population genotypes frequencies were 82.1% and 17.9%, for AA and AB genotypes, respectively. The frequency of A allele was 0.91 and 0.09 of B allele. No association between the identified polymorphism and AFC, CI, and MY was observed. The LL was positively associated (P<0.05) with the absence of B allele. Animals carrying the AA genotype presented a longer lactation period.

Objective. The ongoing incidence of malignant cutaneous melanoma of the head and neck has become a challenge in many regions of the world, in spite of prophylactic trials such as popular education and screening. Although non-surgical therapies are performed, most melanomas are actually treated by surgical excision. In the last few years, sentinel node biopsy has evolved as a diagnostic and therapeutic tool, and it has permitted a significant minimizing of the morbidity associated with the surgical management of the neck. This article is aimed at providing a thorough review of our experience in head and neck melanoma, as well as a retrospective analysis of locoregional metastases and the predictability of sentinel node biopsy for the staging of melanoma. Design. A retrospective review of our experience over the last two years has been carried out that includes 12 cases of head and neck melanoma where lymphoscintigraphy and sentinel node biopsy were performed. Results. Sentinel lymph nodes were identified using preoperative lymphoscintigraphy and intraoperative gamma probe in 11 cases (91.6%). A total of 21 nodes were identified in the 12 patients, with an average number of 1.75 nodes per patient. The most frequent site where nodes were located was level II of the neck. Two nodes (9.52%) were affected by melanoma. There was minimal morbidity related to this procedure. Conclusions. In spite of the reduced size of the sample and the short-term follow-up, our results are similar to those obtained by other authors, which leads us to believe that sentinel lymph node mapping with biopsy is a reliable technique for the diagnosis of regional spread in head and neck cutaneous melanoma, even in early development stages.

Objetivo. La creciente incidencia del melanoma facial constituye un auténtico reto en muchas regiones del mundo, a pesar de medidas como la educación sanitaria de la población y realización de screenings poblacionales. Aunque también se emplean terapias no quirúrgicas, la mayoría de los melanomas se tratan en la actualidad mediante excisión quirúrgica. En los últimos años, la biopsia del ganglio centinela se ha incorporado como una técnica diagnóstica y terapéutica adicional, y ha permitido una reducción significativa de la morbilidad asociada al manejo quirúrgico del cuello. En el presente artículo pretendemos revisar la experiencia de nuestro equipo con el melanoma de cabeza y cuello en los últimos años, así como analizar retrospectivamente la incidencia de metástasis locoregionales, y la predictibilidad de la biopsia de ganglio centinela para su estadiaje. Diseño del estudio. Se ha revisado retrospectivamente nuestra experiencia en los dos últimos años con 12 casos de melanoma de cabeza y cuello en que se realizó linfoescintigrafía y biopsia de ganglio centinela. Resultados. La identificación del ganglio centinela mediante sonda de captación gamma se consiguió en 11 de los casos (91,6%). Se identificaron un total de 21 ganglios centinela, es decir, 1,75 ganglios por paciente, siendo el nivel II cervical la localización más frecuente. Dos de ellos (9,52%) resultaron afectados por melanoma. La morbilidad residual como consecuencia de la biopsia de los ganglios centinelas ha sido mínima. Conclusiones. A pesar del reducido tamaño de la muestra y de la falta de seguimiento a largo plazo, nuestros resultados son similares a los obtenidos por otros autores, lo que nos induce a considerar la linfoescintigrafía y biopsia de ganglio centinela como una técnica fiable, incluso ya desde fases iniciales de su implantación.

O reconhecimento da Febre Purpúrica Brasileira (FPB), em 1984, originou uma série de estudos que revelaram uma correlação desta doença com conjuntivites causadas por Haemophiliis aegyptius. A associação do aumento de conjuntivites em crianças e a maior densidade populacional de cloropídeos do gênero Hippelates já havia sido verificada desde o século passado. Este fenômeno está relacionado ao tropismo que estes insetos apresentam pelos olhos, secreções e feridas de onde se alimentam. Embora haja evidências do papel destes cloropídeos na transmissão mecânica de conjuntivites bacterianas, o isolamento de Haemophilus aegyptius a partir dos mesmos, no seu habitat natural, ainda não havia sido verificado. No presente trabalho obtivemos o isolamento de cepas invasivas de Haemophilus aegyptius, associadas à FPB, de duas coleções de cloropídeos, classificados como Liohippelates peruanus e uma espécie nova, Hippelates neoproboscideus, coletados ao redor dos olhos de crianças com conjuntivite.

The recognition of the Brazilian purpuric fever (BPF) in 1984 led to a number of studies which showed a relation between this disease and conjunctivitis caused by Haemophilus aegyptius. The increase in cases of conjunctivitis in children associated with higher population density of eye gnats (Chloropidae: Hippelates) has been reported since last century. This phenomenon is related to the attraction that those flies show for the eyes, secretions and wounds, from where they feed on. Although there are evidences on the role of these flies in the mechanical transmission of seasonal bacterial conjunctivitis, the isolation of Haemophilus aegyptius from them in their natural habitat had not been demonstrated yet. In this study Haemophilus aegyptius associated to BPF was isolated from two pools of chloropids collected around the eyes of children with conjuntivitis which were identified as Liohippelates peruanus (Becker) and a new species Hippelates neoproboscideus.