The Slow Search for Solutions: Lessons from Historical Energy Transitions by Sector and Service

28 p.

The Health Effects of Climate Change: A Survey of Recent Quantitative Research

44 p.

International Support of Climate Change Policies in Developing Countries: Strategic, Moral and Fairness Aspects

33 p.

International Climate Finance and its Influence on Fairness and Policy

27 p.

Uma revisão sobre instrumentos de avaliação do estado funcional do idoso

Este estudo visa avaliar, através de uma revisão, as qualidades conceituais e psicométricas dos instrumentos de avaliação do estado funcional do paciente idoso, e de suas adaptações para o contexto do Brasil. A dissertação está estruturada em três partes. A primeira é constituída de cinco seções que introduzem os temas do envelhecimento da população mundial e de países emergentes como o Brasil como razões de base para um estudo do atendimento do paciente idoso. Descreve-se o que se entende por estado funcional do paciente idoso no contexto da avaliação geriátrica interdisciplinar. A parte 2 se constitui no artigo da dissertação. Na seção de material e métodos descreve-se detalhadamente a revisão realizada e os bancos de dados utilizados. Nas últimas duas seções do artigo apresentam-se os resultados e a discussão, em que se verificam, em primeiro lugar, um bom número de instrumentos com propriedades psicométricas adequadas que avaliam as subdimensões do estado funcional. Dos 30 instrumentos escolhidos utilizando critérios explicitados pelos autores, apenas dois, o Multiple Outcomes Study SF-36 e o Health Assessment Questionnaire, possuem adaptação para 0 português. Entretanto, alguns dos instrumentos revisados vêm sendo utilizados em nosso meio sem adaptação formal prévia. Vários destes instrumentos possuem bons históricos em sua língua original, porém este fato ainda não despertou a preocupação da comunidade brasileira para adaptações formais dos mesmos. Também se constatam a escassez de estudos de adaptação e concepção de instrumentos desta dimensão no contexto brasileiro. Alguns aspectos deste problema são discutidos, além de possíveis caminhos para corrigi-lo. Na parte final desta dissertação são sucintamente descritos os instrumentos de cada subdimensão de estado funcional escolhidos como mais interessantes na parte 2. Em seguida, são indicadas outras dimensões consideradas pertinentes para um escrutínio semelhante. A conclusão geral sugere uma melhor utilização de medidas de saúde estruturadas no contexto da avaliação geriátrica no Brasil.

On innate and specific aspects of human language

Mixel Aurnague, Kepa Korta and Jesus M. Larrazabal (eds.)

Mechanistic aspects of the Ziegler-Natta polymerization

The isotope effect on propagation rate was determined for four homogeneous ethylene polymerization systems. The catalytic system Cp_2Ti(Et)Cl + EtA1Cl_2 has a k^H_p/k^D_p = 1.035 ± 0.03. This result strongly supports an insertion mechanism which does not involve a hydrogen migration during the rate determining step of propagation (Cossee mechanism). Three metal-alkyl free systems were also studied. The catalyst I_2 (PMe_3)_3Ta(neopentylidene)(H) has a k^H_p/k^D_p = 1.709. It is interpreted as a primary isotope effect involving a non-linear a-hydrogen migration during the rate determining step of propagation (Green mechanism). The lanthanide complexes Cp*_2LuMe•Et_2O and Cp*_2YbMe•Et_2O have a k^H_p/k^D_p = 1.46 and 1.25, respectively. They are interpreted as primary isotope effects due to a partial hydrogen migration during the rate determining step of propagation.

The presence of a precoordination or other intermediate species during the polymerization of ethylene by the mentioned metal-alkyl free catalysts was sought by low temperature NMR spectroscopy. However, no evidence for such species was found. If they exist, their concentrations are very small or their lifetimes are shorter than the NMR time scale.

Two titanocene (alkenyl)chlorides (hexenyl 1 and heptenyl 2 were prepared from titanocene dichloride and a THF solution of the corresponding alkenylmagnesium chloride. They do not cyclize in solution when alone, but cyclization to their respective titanocene(methyl(cycloalkyl) chlorides occurs readily in the presence of a Lewis acid. It is demonstrated that such cyclization occurs with the alkenyl ligand within the coordination sphere of the titanium atom. Cyclization of 1 with EtAlCl_2 at 0°C occurs in less than 95 msec (ethylene insertion time), as shown by the presence of 97% cyclopentyl-capped oligomers when polymerizing ethylene with this system. Some alkyl exchange occurs (3%). Cyclization of 2 is slower under the same reaction conditions and is not complete in 95 msec as shown by the presence of both cyclohexyl-capped oligomers (35%) and odd number α-olefin oligomers (50%). Alkyl exchange is more extensive as evidenced by the even number n-alkanes (15%).

Cyclization of 2-d_1 (titanocene(hept-6-en-1-yl-1-d_1)chloride) with EtA1Cl_2 demonstrated that for this system there is no α-hydrogen participation during said process. The cyclization is believed to occur by a Cossee-type mechanism. There was no evidence for precoordination of the alkenyl double bond during the cyclization process.

Freshwater biological research in Mexico: A brief historical review

Apart from a couple of early papers in the 1600s, the development of freshwater biology as a science in Mexico began in the last century. Taxonomic studies were made especially on algae, aquatic insects, crustaceans, annelid worms and aquatic plants. The great impetus acquired by limnology in Europe and America in the first half of the 20th Century stimulated foreign researchers to come and work in Mexico. During this period the Instituto de Biologia, belonging to the Universidad Nacional Autonoma de Mexico, was created in 1930. The Institute had a section of Hydrobiology that contributed to the limnological characterization of Mexican lakes and ponds. In 1962, the Instituto Nacional de Investigaciones Biologico-Pesqueras was created to bring together the work of several institutes working on the native ichthyofauna, the restocking of reservoirs, and aquaculture.

Limnology in Argentina: An historical account

This short review includes major books, articles and episodes concerned with studies on inland waters that have affected the development of limnology in Argentina. It is divided into three periods; (1) an early period of protolimnologists; (2) a period previous to the present times, subdivided into a first stage from 1900 to 1938 and a second stage from 1938 to 1962; and (3) a period of integrated research.

Ecological aspects of New Forest streams, draining one of Britain's unique areas

This article describes the streams of this unique area of Britain and reviews the published and some unpublished information that is currently available. None of the rivers in the New Forest are more than 30 km long. Many reaches have been artificially straightened, channelized and regraded since the 1840's. The stream waters are typically base-poor, with low nutrient concentrations. Primary productivity and standing crops of algae are predictably low when compared with other streams carrying higher concentrations of minerals and nutrients. The earliest records on the macroinvertebrate fauna go back to the late 19th Century. By 1940, over 20 species of Trichoptera and 10 species of Plecoptera had been recorded, but only four species of Ephemeroptera. Twenty species of fish occur in the streams of the New Forest of which the most common are brown trout, minnow, bullhead, stone loach, brook lamprey and eel.

Limnological aspects of three man-made lakes in Sri Lanka

An investigation was undertaken to study the physicochemical characteristics, phytoplankton and fish fauna of three major deep lakes on the River Mahaweli: Kotmale, Victoria and Randenigala. These lakes were created mainly for hydroelectric purposes during the period 1984 to 1986. In all three lakes, thermoclines were present during most months of the year, but did not appear to be very stable. They tended to disappear during January - February but were well established in August - November. Fifteen species of blue-green algae were identified as well as 27 desmid species and 25 non-desmid green algae. Melosira granulata and M. undulata were the dominant diatom species. The family Cyprinidae dominated the fish fauna by number of species, but by biomass the exotic cichlids (tilapias) were dominant.

The importance of organic detritus in lotic ecosystems: Aspects of trophic interactions

Very little research has been carried out on detrital energetics and pathways in lotic ecosystems. Most investigations have concentrated on the degradation of allochthonous plant litter by fungi, with a glance at heterotrophic bacteria associated with decaying litter. In this short review, the author describes what is known of the detrition of plant litter in lotic waters, which results from the degradative activities of colonising saprophytic fungi and bacteria, and goes on to relate this process to those invertebrates that consume coarse and/or fine particulate detritus, or dissolved organic matter that aggregates into colloidal exopolymer particles. It is clear that many of the key processes involved in the relationships between the physical, chemical, biotic and biochemical elements present in running waters are very complex and poorly understood. Those few aspects for which there are reliable models with predictive power have resulted from data collections made over periods of 20 years or more. Comprehensive research of single catchments would provide a fine opportunity to collect data over a long period.