The Potential of Public Participation Geographic Information Systems in UK Environmental Planning: Appraisals by Active Publics

The paper draws on an empirical study of two workshops in which the issues that arise from the use of geographic information systems (GIS) as a planning tool in public participation settings were explored by local residents who take an active interest in local planning matters in their London borough. The paper demonstrates how issues concerned with the democratization of GIS and public participation GIS (PPGIS) informed the structure and conduct of the workshops and the qualitative analysis of the workshop discussions. Key themes raised by participants included: the potential of PPGIS as a means of extending knowledge networks; issues of data ownership and the responsiveness of data providers to public concerns; and the role that institutional norms and practices play in democratizing information availability and the transparency of the decision-making process. The paper concludes that the potential of PPGIS as a planning tool cannot be separated from public concerns about the legitimacy of the planning process or local government.     

DENSITY CURRENT INTRUSIONS IN AN ICE-COVERED URBAN LAKE1

ABSTRACT: Evidence is presented that snowmelt runoff from an urban watershed can produce density current intrusions (underflows) in a lake. Several episodes of density current intrusions are documented. Water temperatures and salinities measured near the bottom of a 10 m deep Minneapolis lake during the late winter warming periods in 1989, 1990, 1991, and 1995 show significant rapid changes which are correlated with observed higher air temperatures and snowmelt runoff. The snowmelt runoff entering this particular lake (Ryan Lake) has increased electrical conductivity, salinity, and density. The source of the salinity is the salt spread on urban streets in the winter. Heating of littoral waters in spring may also contribute to the occurrence of the sinking flows, but is clearly not the only cause.     

HISTORICAL TRENDS IN SEDIMENTATION RATES AND SEDIMENT PROVENANCE,FAIRFIELD LAKE,WESTERN NORTH CAROLINA1

Sedimentation rates and sediment provenance were examined for lacustrine sediments deposited in Fairfield Lake, western North Carolina, during the past 111 years. Stratigraphic, radionuclide, and cartographic data indicate that sedimentation rates have increased several fold during the past three decades in response to localized development. The magnitude of increased sedimentation was surprising given limited development within the basin: 0.12 to 0.68 buildings/ha in 2000 in those parts directly delivering sediment to the dated cores. Thus, the analysis illustrates the potential sensitivity of watersheds in the southern Appalachians to changes in land cover. An approach that combined geochemical fingerprinting with sediment mixing models was subsequently evaluated to determine its ability to accurately estimate the contribution of sediment from (1) major bedrock formations that underlie the watershed and (2) potential sources associated with four land cover categories. Sediment sources in both analyses proved difficult to geochemically fingerprint to greater than 90 percent accuracy using data on acid‐soluble metals and selected isotopes of lead (Pb). The relative contributions of sediment from delineated sources, estimated by the mixing models, generally corresponded with known temporal and spatial patterns of land cover. However, the models were plagued by two significant problems — the chemical alteration of sediments as they were transported through upland streams to depositional sites within the lake and the loss of elemental mass. Thus, future investigations using the fingerprinting approach in this area of intense weathering, and presumably others, will need to modify the existing methods to more accurately elucidate changes in sediment provenance related to development.     

Some unusual case histories from personal experience

Is protection of equipment the only consideration when setting the relieving pressures of safety relief valves? I will show you a case where other factors should have been considered and suggest that you might give your safety valve set pressures a second thought.Do you have side-by-side pieces of identical equipment? If so, you must consider that operating or maintenance personnel may become confused, and the results maybe catastrophic. A PVC reactor incident will demonstrate this point.Does your process contain materials that could decompose? After thirty years of safe operation in butadiene units, there was a vinyl acetylene decomposition. Could it happen to you?It is my hope that these three unique and unusual cases will provide valuable information for operations and maintenance personnel, managers, safety professionals, and engineers.     

Saturated uptake kinetics: transient response of the marine diatom Thalassiosira pseudonana to ammonium,nitrate, silicate or phosphate starvation

Changes in the saturated uptake kinetics of the limiting nutrient were followed as Thalassiosira pseudonana (Clone 3 H) batch cultures entered ammonium, nitrate, silicate and phosphate starvation. Cultures starved of ammonium or phosphate developed very high specific uptake capacities over a 24 to 48 h starvation period, due to both decreases in cell quota and increases in uptake rates per cell. In particular, the cell phosphorus quota decreased ca. 8-fold during phosphate starvation and specific uptake rates exceeded 100 d^-1. In contrast, cultures entering nitrate or silicate starvation underwent little or no further cell division, and the uptake capacity declined during starvation. After 24 to 48 h starvation, an induction requirement for uptake of nitrate or silicate was apparent. These responses are consistent with adaptation to the pattern of supply of these nutrients in the field.     

Taxonomic revisions in the marine biflagellate fungi: The ultrastructural evidence

The ultrastructure of the genera Althornia, Aplanochytrium, Japonochytrium, Schizochytrium and Thraustochytrium is described, and all are regarded as members of the new order Thraustochytriales Sparrow. Species considered are Althornia crouchii, Aplanochytrium kerguelensis, Hyalochlorella marina, Japonochytrium sp., Schizochytrium aggregatum, Thraustochytrium kinnei and T. striatum. All but H. marina are, on ultrastructural evidence, related genera, and some speculative suggestions are made about possible interrelationships both between the species discussed, between the Thraustochytriales and Labyrinthulales, and between these two and other major taxa.     

Nitrogen assimilation by phytoplankton and other microorganisms in the surface waters of the central North Pacific Ocean

Assimilation rates of ¹⁵N-labelled ammonium, urea, and nitrate by plankton in the upper euphotic zone were measured in 2 summer, 2 winter, and 1 spring cruise in the central North Pacific Ocean. Average rates of ammonium plus urea assimilation could not be determined precisely, but were estimated to be 7 to 25 g-at. N m^-3 day^-1. Indirect evidence suggested that non-photosynthetic microorganisms contributed to these rates. Nitrate assimilation was negligible in the upper waters considered in this report (above the chlorophyll maximum and the nutricline). Potential, nitrate-saturated rates were in the range 1 to 8 g-at. N m^-3 day^-1. Seasonal comparison showed lowest rates of both carbon and nitrogen assimilation rates per chlorophyll a in winter.     

Marine diatoms grown in chemostats under silicate or ammonium limitation. II. Transient response of Skeletonema costatum to a single addition of the limiting nutrient

Skeletonema costatum was grown at different steady-state growth rates in ammonium or silicate-limited chemostats. The culture was perturbed from its steady-state condition by a single addition of the limiting nutrients ammonium or silicate. The transient response was followed by measuring nutrient disappearance of the liliting perturbation experiment indicate that three distinct modes of uptake of the limiting nutrient can be distinguished; surge uptake (V _s ), internally controlled uptake (V _i ), and externally controlled uptake (V _e ). An interpretation of these three modes of uptake is given and their relation to control of uptake of the limiting nutrient is discussed. The uptake rates of the non-limiting nutrients were shown to be depressed during the surge of the uptake of the limiting nutrient. Kinetic uptake parameters, K _s and V _max, were obtained from data acquired during the externally controlled uptake segment, V _e . The same V _max value of 0. 12 h^-1, was obtained under either silicate or ammonium limitation. Estimates of K _s were 0.4 g-at NH₄-N l^-1 and 0.7 g-at Si l^-1. Short-term ¹⁵N uptake-rate measurements conducted on nitrogen-limited cultures appear to be a combination of V _s or V _i , or at lower substrate concentrations V _s and V _e . It is difficult to separate these different uptake modes in batch or tracer experiments, and ensuing problems in interpretation are discussed.Contribution No. 882 from the Department of Oceanography, University of Washington, Seattle, Washington 98195, USA. This work represents portion of three dissertations submitted to the Department of Oceanography, University of Washington, Seattle, in partial fulfillment of the requirements for the Ph.D. degree.     

Role of Genetic Background in the Success of Reintroduced Peregrine Falcons

Abstract: Peregrine Falcons (    Falco peregrinus ) of seven subspecies from four continents were bred in captivity, and approximately 1173 of their progeny were released in the midwestern United States and adjacent regions of Ontario and Manitoba in an attempt to replace the original population that was extirpated by chlorinated hydrocarbon poisoning in the 1950s. We analyzed the success of individuals of the different subspecies introduced to the Midwest. Five of the seven subspecies released have contributed to the current breeding population. Subspecies of breeding Peregrine Falcons were equally represented when breeding birds of high productivity were compared with less prolific breeders. The subspecific makeup of the breeding population did not differ significantly from that of the released population, suggesting that adaptability in this species was sufficient to override genetic differences between subspecies. Peregrines of widely different genetic stocks have thrived after release, making substantial genetic contributions to the new population.