Antigens in human glioblastomas and meningiomas: Search for tumour and onco-foetal antigens. Estimation of S-100 and GFA protein.

Extracts of glioblastomas and meningiomas were analysed by quantitative immunoelectrophoresis for the presence of foetal brain antigens and tumour-associated antigens, and levels of 2 normal brain-specific proteins were also determined. The following antibodies were used: monospecific anti-S-100 (glia specific); monospecific anti-GFA (glial fibrillary acidic protein), (astroglia specific); polyspecific anti-foetal brain (12-16th week of gestation); a polyspecific anti-glioblastoma antiserum, absorbed with insolubilized serum, haemolysate and normal brain extract; polyspecific anti-alpha-foetoprotein; and monospecific anti-ferritin. Using the antibodies raised against the tumours, several antigens not present in foetal or adult normal brain were found in the glioblastomas and the meningiomas. These antigens cross-reacted with antigens present in normal liver and were therefore not tumour-associated. S-100 was found in glioblastomas in approximately one tenth the amount in whole brain homogenate, whereas GFA was found 2-4 times enriched. The 2 proteins were absent in meningiomas. The possible use of the GFA protein as a marker for astroglial neoplasia is discussed. Five foetal antigens were found in foetal brain, but none in the tumours. alpha-Foetoprotein could only be demonstrated in foetal tissue extracts, including foetal brain, but not in tumours. Ferritin was detected in all tumour extracts, although the amounts determined were unrelated to histological tumour type

Preparing Scientists, Policy-Makers, and Managers for a Fast-Forward Future

Ecosystems in the Sacramento–San Joaquin Delta are changing rapidly, as are ecosystems around the world. Extreme events are becoming more frequent and thresholds are likely to be crossed more often, creating greater uncertainty about future conditions. The accelerating speed of change means that ecological systems may not remain stable long enough for scientists to understand them, much less use their research findings to inform policy and management. Faced with these challenges, those involved in science, policy, and management must adapt and change and anticipate what the ecosystems may be like in the future. We highlight several ways of looking ahead—scenario analyses, horizon scanning, expert elicitation, and dynamic planning—and suggest that recent advances in distributional ecology, disturbance ecology, resilience thinking, and our increased understanding of coupled human–natural systems may provide fresh ways of thinking about more rapid change in the future. To accelerate forward-looking science, policy, and management in the Delta, we propose that the State of California create a Delta Science Visioning Process to fully and openly assess the challenges of more rapid change to science, policy, and management and propose appropriate solutions, through legislation, if needed

A economia da pecuária na Amazônia oriental

Este trabalho é uma simulação econômica de operações pecuárias em grande escala na Bacia Amazônica, as quais receberam linhas de crédito subsidiado e incentivos fiscais de vários tipos. Nosso estudo analisa a lucratividade de operações de bovinocultura sob quatro tecnologias de produção, sob preços variáveis de insumos e produtos e a diferentes taxas de valorização da terra. O desenvolvimento da infra-estrutura e o comprometimento do governo brasileiro em integrar a regiao à economia nacional produziu uma alta generalizada nos preços das terras, contribuindo para uma dinâmica especulativa que caracterizou os mercados de terra brasileiros ao longo dos últimos vinte anos.Este estudo demonstra haver muitas condições sob as quais o investimento em pecuária na Amazônia pode ser lucrativa, embora a maioria dos cenários envolva sobrepastejo, subsídios, preços altos para o gado e baixos para os insumos, valorização da terra ou ainda combinações de todas essas condições. O que mais se destaca na simulação é o fato de o sobrepastejo ser a mais lucrativa estratégia de produção na maior parte dos cenários considerados, em virtude do rápido declínio da produtividade das pastagens na Amazônia. Estes resultados tern duas importantes implicações: primeira, que a pecuaria pode expandir-se e ser lucrativa mesmo sem subsídios, sob certos preços do produto e/ou através de uma estrat´égia de contínuo desflorestamento e sobrepastejo: segunda, que a lucratividade do investimento é aumentada em meio a contextos de maior utilização de insumos e maior produção, marcados pela presença de subsídios e/ou valorização da terra.This study is an economic simulation of large scale livestock operations in the Amazon Basin which recieved subsidized credit lines and fiscal incentives of various types. Our study analyses the profitability of livestock operations under four production technologies, under varying input and product prices, and at different rates of land appreciation. Infrastructure development, and the commitment of the Brazilian government to integrate the region into the national economy produced a generalized boom in land prices which contributed to a speculative dynamic in Brazilian land markets that has continued for the last twenty years. This study shows that there are many conditions where investment in livestock [n the Amazon can be profitable, but most of these scenarios imply either overgrazing, subsidies, conditions of high cattle prices and low input prices, land appreciation or combinations of all of these. What is most salient in the simulation is that overgrazing is the most profitable production strategy under most pricing scenarios given the rapid decline of pasture productivity in Amazonia. These results have two important implications: first, livestock activities can expand and be profitable even without subsidies under certain product prices and/or through a strategy of continued clearing and overgrazing. Second, profitability of investment is increased across more input and product contexts with subsidies and/or land appreciation

Linking Human Health to Biological Diversity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74648/1/j.1523-1739.1997.0110061459.x.pd

Using the stated preference method for the calculation of social discount rate

The aim of this paper is to build the stated preference method into the social discount rate methodology. The first part of the paper presents the results of a survey about stated time preferences through pair-choice decision situations for various topics and time horizons. It is assumed that stated time preferences differ from calculated time preferences and that the extent of stated rates depends on the time period, and on how much respondents are financially and emotionally involved in the transactions. A significant question remains: how can the gap between the calculation and the results of surveys be resolved, and how can the real time preferences of individuals be interpreted using a social time preference rate. The second part of the paper estimates the social time preference rate for Hungary using the results of the survey, while paying special attention to the pure time preference component. The results suggest that the current method of calculation of the pure time preference rate does not reflect the real attitudes of individuals towards future generations