TRANSGENIC CROPS AND THE ENVIRONMENT: MISSING MARKETS AND PUBLIC ROLE

The rapidity of change has left scant opportunity for investigation of the consequences of biotechnology adoption on long-term ecosystem or economic system functioning. Economic theory suggests that, if the "Biotechnology Revolution" is left to market forces alone,there will be neglected public goods. Theory and limited empirical evidence suggests that there are significant incentives for private firms to discount and neglect certain environmental impacts and to develop products that meet only the needs of those able and willing to pay. Negative distributional impacts on rural societies and economies will not normally enter the private calculus nor will the long-term problems of insect and plant resistance. Thus, there is a strong case for enhanced public roles with respect to the use of transgenic crops. The adoption of the precautionary approach in public policies addressing transgenic crops is one alternative to better reflect public concerns.Environmental Economics and Policy, Research and Development/Tech Change/Emerging Technologies,

A pilot demonstration project of technology application from the aerospace industry to city management (four cities program)

The Four Cities Program has completed the first year of the planned two-year program. At the beginning of the first year, a variety of program initiation activities were accomplished. Contracts were negotiated; science and technology advisors were interviewed, selected and assigned; general indoctrination and integration of the advisors into city affairs occurred; technical needs were identified and related projects pursued; pilot projects for the second year were identified; inter-city coordination on technical problems began to emerge; and the general soundness of the four cities program seems to have been established. Above all, the inter-personal relationships between the advisors and their interfaces in city government appear to be functioning smoothly. The establishment of such mutual respect, trusts, and confidences are believed essential to the success of the program

Parametrization of gamma-ray production cross-sections for pp interactions in a broad proton energy range from the kinematic threshold to PeV energies

Using publicly available Monte Carlo codes as well as compilation of published data on p--p interactions for proton kinetic energy below 2 GeV, we parametrize the energy spectra and production rates of $\gamma$-rays by simple but quite accurate ($\leq 20 \%$) analytical expressions in a broad range from the kinematic threshold to PeV energies.Comment: 19 pages, 15 figures, v2 version fixes the cross reference

Extensive Characterization of Seismic Laws in Acoustic Emissions of Crumpled Plastic Sheets

Statistical similarities between earthquakes and other systems that emit cracking noises have been explored in diverse contexts, ranging from materials science to financial and social systems. Such analogies give promise of a unified and universal theory for describing the complex responses of those systems. There are, however, very few attempts to simultaneously characterize the most fundamental seismic laws in such systems. Here we present a complete description of the Gutenberg-Richter law, the recurrence times, Omori's law, the productivity law, and Bath's law for the acoustic emissions that happen in the relaxation process of uncrumpling thin plastic sheets. Our results show that these laws also appear in this phenomenon, but (for most cases) with different parameters from those reported for earthquakes and fracture experiments. This study thus contributes to elucidate the parallel between seismic laws and cracking noises in uncrumpling processes, revealing striking qualitative similarities but also showing that these processes display unique features.Comment: Accepted for publication in EP

Resources/Services Available to the Handicapped of Southside Tidewater Virginia

Two research objectives were set up for this study. These included: 1. Accumulate and analyze data on the services and resources available to the handicapped in the Southside Tidewater area; 2. Develop a method or media for information dissemination to those who work with the targeted population

Distance to the scaling law: a useful approach for unveiling relationships between crime and urban metrics

We report on a quantitative analysis of relationships between the number of homicides, population size and other ten urban metrics. By using data from Brazilian cities, we show that well defined average scaling laws with the population size emerge when investigating the relations between population and number of homicides as well as population and urban metrics. We also show that the fluctuations around the scaling laws are log-normally distributed, which enabled us to model these scaling laws by a stochastic-like equation driven by a multiplicative and log-normally distributed noise. Because of the scaling laws, we argue that it is better to employ logarithms in order to describe the number of homicides in function of the urban metrics via regression analysis. In addition to the regression analysis, we propose an approach to correlate crime and urban metrics via the evaluation of the distance between the actual value of the number of homicides (as well as the value of the urban metrics) and the value that is expected by the scaling law with the population size. This approach have proved to be robust and useful for unveiling relationships/behaviors that were not properly carried out by the regression analysis, such as i) the non-explanatory potential of the elderly population when the number of homicides is much above or much below the scaling law, ii) the fact that unemployment has explanatory potential only when the number of homicides is considerably larger than the expected by the power law, and iii) a gender difference in number of homicides, where cities with female population below the scaling law are characterized by a number of homicides above the power law.Comment: Accepted for publication in PLoS ON

Scale-adjusted metrics for predicting the evolution of urban indicators and quantifying the performance of cities

More than a half of world population is now living in cities and this number is expected to be two-thirds by 2050. Fostered by the relevancy of a scientific characterization of cities and for the availability of an unprecedented amount of data, academics have recently immersed in this topic and one of the most striking and universal finding was the discovery of robust allometric scaling laws between several urban indicators and the population size. Despite that, most governmental reports and several academic works still ignore these nonlinearities by often analyzing the raw or the per capita value of urban indicators, a practice that actually makes the urban metrics biased towards small or large cities depending on whether we have super or sublinear allometries. By following the ideas of Bettencourt et al., we account for this bias by evaluating the difference between the actual value of an urban indicator and the value expected by the allometry with the population size. We show that this scale-adjusted metric provides a more appropriate/informative summary of the evolution of urban indicators and reveals patterns that do not appear in the evolution of per capita values of indicators obtained from Brazilian cities. We also show that these scale-adjusted metrics are strongly correlated with their past values by a linear correspondence and that they also display crosscorrelations among themselves. Simple linear models account for 31%-97% of the observed variance in data and correctly reproduce the average of the scale-adjusted metric when grouping the cities in above and below the allometric laws. We further employ these models to forecast future values of urban indicators and, by visualizing the predicted changes, we verify the emergence of spatial clusters characterized by regions of the Brazilian territory where we expect an increase or a decrease in the values of urban indicators.Comment: Accepted for publication in PLoS ON

Calibrating sprayers and spreaders for athletic fields and golf courses (2000)

This guide will discuss the calibration of hand-held pump-up or knapsack sprayers, large self-propelled or pull-behind sprayers, drop spreaders and rotary-type spreaders.New 5/00/7M