The effect of heated effluents from power plants on seagrass (Thalassia) communities quantitatively comparing estuaries in the subtropics to the tropics

The need for most efficient use of energy is abruptly in conflict with the need to maintain environmental quality in terms of heated effluents released from power plants. This study synthesizes biological results found from four effluent canals from power plants releasing heat on shallow estuaries: tropics, edge of tropics and subtropics. The dominant near-shore community in the Gulf of Mexico and Caribbean is that of Thalassia, rich in animal and plant abundance and biomass. Summer mean temperatures in all three estuaries ranged around 30°C. Results show sustained temperatures of +5°C in summer denude the area of the Thalassia community. Temperatures +1 and +1.5°C were minimally damaging to the studied areas and can be considered rational release temperatures. Insufficient data was available at +2°C to make a statement; +4°C areas showed intense damage to the biological communities at all locations; +3°C effect varied from severe damage in the subtropics to 40% damage in the tropics. Recommended summer heated effluent release for power plants eliminating heat onto Thalassia beds would certainly nerver be greater than +3°C. A trade-off decision must be made by decision-makers as to +3 or +2°C as the upper permissable limit. Winter release of effluent temperature in areas where winter temperatures fall below 25°C could be above +3°C apparently without damage. Tropical and subtropical ecosystems are on the brink of disaster and small increments of change by man's activities can push them beyond tolerance limits. Evidently the marine tropics differ from marine temperate zones in their capacity to assimilate man's activities.     

Reference Minerals for the Microanalysis of Light Elements

The quantitative determination of light element concentrations in geological specimens represents a major analytical challenge as the electron probe is generally not suited to this task. With the development of new in situ analytical techniques, and in particular the increasing use of secondary ion mass spectrometry, the routine determination of Li, Be and B contents has become a realistic goal. However, a major obstacle to the development of this research field is the critical dependence of SIMS on the availability of well characterized, homogeneous reference materials that are closely matched in matrix (composition and structure) to the sample being studied. Here we report the first results from a suite of large, gem crystals which cover a broad spectrum of minerals in which light elements are major constituents. We have characterized these materials using both in situ and wet chemical techniques. The samples described here are intended for distribution to geochemical laboratories active in the study of light elements. Further work is needed before reference values for these materials can be finalized, but the availability of this suite of materials represents a major step toward the routine analysis of the light element contents of geological specimens.     

Can Jupiters be found by monitoring Galactic bulge microlensing events from northern sites?

In 1998 the EXPORT team monitored microlensing event light curves using a charge-coupled device (CCD) camera on the IAC 0.8-m telescope on Tenerife to evaluate the prospect of using northern telescopes to find microlens anomalies that reveal planets orbiting the lens stars. The high airmass and more limited time available for observations of Galactic bulge sources make a northern site less favourable for microlensing planet searches. However, there are potentially a large number of northern 1-m class telescopes that could devote a few hours per night to monitor ongoing microlensing events. Our IAC observations indicate that accuracies sufficient to detect planets can be achieved despite the higher airmass.     

Beyond the headlines: changing patterns in international student enrollment in the United States

In the aftermath of the terrorist attacks of September 11, 2001, newspapers and magazines reported a dramatic decline in the enrollment of international students at US universities. Many of these articles blamed this decrease on the difficulties of getting a visa to the US and expressed concern about the potential impact on the US education system and economy. A look beyond the headlines, however, reveals that this decline cannot be attributed exclusively to the heightened security measures, as student numbers from some countries had already begun to decline before 2001 or continue to increase despite the changed regulations. Therefore, other factors also play a role in explaining the diverse migration patterns—most notably increasing competition from other host countries and changing economic and educational conditions in sending countries. Since international students often stay in their host countries after the completion of their degrees, the United States has a strong interest in continuing to attract international students as potential highly skilled immigrants. In order to achieve this, changes need to be implemented at the government level as well as at individual universities.     

Isotope Approach to Assess Hydrologic Connections During Marcellus Shale Drilling

Water and gas samples were collected from (1) nine shallow groundwater aquifers overlying Marcellus Shale in north‐central West Virginia before active shale gas drilling, (2) wells producing gas from Upper Devonian sands and Middle Devonian Marcellus Shale in southwestern Pennsylvania, (3) coal‐mine water discharges in southwestern Pennsylvania, and (4) streams in southwestern Pennsylvania and north‐central West Virginia. Our preliminary results demonstrate that the oxygen and hydrogen isotope composition of water, carbon isotope composition of dissolved inorganic carbon, and carbon and hydrogen isotope compositions of methane in Upper Devonian sands and Marcellus Shale are very different compared with shallow groundwater aquifers, coal‐mine waters, and stream waters of the region. Therefore, spatiotemporal stable isotope monitoring of the different sources of water before, during, and after hydraulic fracturing can be used to identify migrations of fluids and gas from deep formations that are coincident with shale gas drilling.     

Mineralogische Notizen aus dem Mineralogisch-Petrographischen Institut der Universität Heidelberg

Ohne Zusammenfassung     

Voice,Perceived Fairness,Agency Trust,and Acceptance of Management Decisions Among Minnesota Anglers

Although researchers agree that public participation in natural resource decision making is critical to institutional acceptance by stakeholders and the general public, the processes to gain public perceptions of fairness, agency trust, and acceptance of management decisions are not clear. Using results from a mail survey of Minnesota resident anglers, we used structural equation modeling to examine how instrumental versus symbolic motives related to anglers’ perceptions of agency fairness, trustworthiness, and ultimately acceptance of fisheries management decisions. We applied laboratory research on relationships among procedural fairness, trust, and management acceptance, and then tested models incorporating anglers’ perceptions of voice for anglers and nonanglers in management decisions. Results suggested that trust fully mediated the relationship between procedural fairness and management acceptance. Angler perceptions of angler and nonangler voice both related to views of procedural fairness, but angler voice was more strongly related and was also significantly related to acceptance of management decisions.