Gestão ambiental: uma súplica do planeta, um desafio para políticas públicas, incubadoras e pequenas empresas

O texto traz uma reflexão sobre o papel das incubadoras de empresas no apoio a práticas ambientais por micro e pequenas empresas. Reconhecendo as debilidades estruturais das empresas de pequeno porte e as dificuldades para a realização de investimentos ambientais, defende o uso de incubadoras como instrumento de política pública para estimular investimentos ambientais. Identifica um número restrito de incubadoras de tecnologias ambientais, em plano internacional. Relata os resultados de uma pesquisa que avaliou a aplicabilidade de um indicador para apurar o desempenho ambiental de incubadoras. Destacaram-se dois resultados: a) a baixa importância atribuída, pelas incubadoras (e pelas empresas abrigadas) ao desempenho ambiental; e b) a ausência de estímulos, pelas incubadoras, aos investimentos ambientais. Desse último resultado deriva importante conclusão: a de que, uma vez apurados os padrões insatisfatórios de desempenho ambiental, de incubadoras e empresas assistidas, ficariam criadas as condições para a formulação e a implementação de medidas indutoras de novas posturas.

Education in primary school as a strategy to control dengue

A proliferação do Aedes aegypti é propiciada pelo habito de permitir a formação de criadouros em vários tipos de recipientes. Uma das formas de controla-lo é a disseminação do conhecimento sobre o vetor, por conduzir a conscientização e a tomada de medidas contra a sua proliferação. Para avaliar um método de ensino sobre o vetor e a dengue, foram comparando alunos de 5ª e 6ª séries antes e após a intervenção didática. Os alunos com intervenção foram mais aptos em reconhecerem as fases do ciclo e tiveram um discernimento maior sobre a importância dos mosquitos para a saúde. Eles também foram mais aptos em reconhecerem quais medidas de controle são mais eficientes e viáveis, repercutindo em suas residências que apresentaram duas vezes menos criadouros em relação aos que não tiveram intervenção.

Mass fractal characteristics of wet sonogels as determined by small-angle x-ray scattering and differential scanning calorimetry

Low density silica sonogels were prepared from acid sonohydrolysis of tetraethoxysilane. Wet gels were studied by small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC). The DSC tests were carried out under a heating rate of 2 degrees C/min from -120 degrees C up to 30 degrees C. Aerogels were obtained by CO(2) supercritical extraction and characterized by nitrogen adsorption and SAXS. The DSC thermogram displays two distinct endothermic peaks. The first, a broad peak extending from about -80 degrees C up to practically 0 degrees C, was associated to the melting of ice nanocrystals with a crystal size distribution with pore diameter ranging from 1 or 2 nm up to about 60 nm, as estimated from Thomson's equation. The second, a sharp peak with onset temperature close to 0 degrees C, was attributed to the melting of macroscopic crystals. The DSC incremental nanopore volume distribution is in reasonable agreement with the incremental pore volume distribution of the aerogel as determined from nitrogen adsorption. No macroporosity was detected by nitrogen adsorption, probably because the adsorption method applies stress on the sample during measurement, leading to a underestimation of pore volume, or because often positive curvature of the solid surface is in aerogels, making the nitrogen condensation more difficult. According to the SAXS results, the solid network of the wet gels behaves as a mass fractal structure with mass fractal dimension D=2.20 +/- 0.01 in a characteristic length scale below xi=7.9 +/- 0.1 nm. The mass fractal characteristics of the wet gels have also been probed from DSC data by means of an earlier applied modeling for generation of a mass fractal from the incremental pore volume distribution curves. The results are shown to be in interesting agreement with the results from SAXS.

A natural combinatorial chemistry strategy in acylpolyamine toxins from Nephilinae orb-web spiders

The present study shows how nature combined a small number of chemical building blocks to synthesize the acylpolyamine toxins in the venoms of Nephilinae orb-web spiders. Considering these structures in four parts, it was possible to rationalize a way to represent the natural combinatorial chemistry involved in the synthesis of these toxins: an aromatic moiety is connected through a linker amino acid to a polyamine chain, which in turn may be connected to an optional tail. The polyamine chains were classified into seven subtypes (from A to G) depending on the way the small chemical blocks are combined. These polyamine chains may be connected to one of the three possible chromophore moieties: 2,4-dihydroxyphenyl acetic acid, or 4-hydroxyindole acetic acid, or even with the indole acetic group. The connectivity between the aryl moiety and the polyamine chain is usually made through an asparagine residue; optionally a tail may be attached to the polyamine chain; nine different types of tails were identified among the 72 known acylpolyamine toxin structures. The combinations of three chromophores, two types of amino acid linkers, seven sub-types of polyamine backbone, and nine options of tails results in 378 different structural possibilities. However, we detected only 91 different toxin structures, which may represent the most successful structural trials in terms of efficiency of prey paralysis/death.

Local and remote lesions in horses subjected to small colon distension and decompression

The purpose of this study was to observe and characterize colonic and lung lesions in horses subjected to experimental distension and decompression of the small colon. Sixteen healthy adult horses were divided into 2 groups: 9 horses that were subjected to distension of the small colon by means of a latex balloon surgically implanted in the lumen and inflated to a pressure of 40 mm Hg for 4 h, and 7 horses in which the balloon was implanted but not inflated. Colonic biopsy specimens were collected before balloon implantation, at the end of the period of obstruction, and 1.5 and 12 h after decompression and were examined for hemorrhage, edema, and neutrophil infiltration; myeloperoxidase (MPO) activity and hemoglobin concentration were measured as well. At the end of the experiment, lung samples were also collected and examined for neutrophil accumulation and MPO activity. The mucosa was not affected by luminal distension; lesions were restricted to the seromuscular layer. Neutrophil accumulation and edema were observed in the samples from both groups of horses but were greater in those from the distension group, in which there was also hemorrhage, fibrin deposition, and increased MPO activity in the seromuscular layer. Similarly, there was greater accumulation of neutrophils in the lung samples from the distension group than in those from the sham-operated group, as determined by histologic evaluation and MPO assay. These findings provide new evidence of reperfusion injury and a systemic inflammatory response, followed by remote lesions, in horses with intestinal obstruction.

Interaction of mercury(II) with humic substances from the Rio Negro (Amazonas State, Brazil) by means of an ion exchange procedure

The aquatic humic substances (HS) investigated in this study with respect to their binding capability towards mercury(II) were isolated from the river Rio Negro, Amazonas State - Brazil, by means of the adsorbent XAD 8. Labile/inert fractions of inorganic Hg(II) complexes formed with these HS were characterized using an ion-exchange batch and column technique, respectively, based on Chelite S. This collector exhibits high Hg(II) distribution coefficients, Kd, up to the order of 104 decreasing, however, in the case of small Hg(II)/HS ratios (< 0.1 μg Hg(II) / mg HS). The influence of different complexation parameters (ratio of Hg(II)/HS, pH, contact time, complexing time) relevant for Hg(II) binding in aquatic environments was assessed. The Hg(II) lability in dissolved HS is mainly influenced by the mass ratio of Hg(II)/HS and the ageing of Hg(II)-HS species formed. This is particularly obvious in the case of low Hg(II) loading of HS where slow transformation processes of freshly formed Hg(II)-HS species significantly decrease their lability, leading to incomplete recoveries (< 20%) of the total Hg(II) bound to HS.

Latin America and the Caribbean in the World Economy 2005-2006

Includes bibliography

Latin America and the Caribbean in the World Economy 2007: 2008 trends

Includes bibliography

Structural change and productivity growth, 20 years later: old problems, new opportunities

Includes bibliography

Promoting corporate social responsibility in small and medium enterprises in the Caribbean: methodology report

Incluye Bibliografía

Caribbean trade and integration: trends and future prospects

Includes Bibliography

The current situation of small and medium-sized industrial enterprises in Trinidad & Tobago, Barbados and St. Lucia

Includes bibliography

Towards a theory of the small firm: theoretical aspects and some policy implications

Includes bibliography

Korean OFDI: investment strategies and corporate motivations for investing abroad

Includes bibliography

Determinantes económicos del salario mínimo en países pequeños y abiertos: una aplicación para Centroamérica

Incluye Bibliografía