OPINIONS RELATING TO FLUORIDATION: DEVELOPMENT OF MEASURES1

ABSTRACT. Elected officials, technical specialists and the public are talking more about “citizen input” into the decision process, and how the people view a given issue or kind of public service. However, problem definition and valid instruments are needed before we can meaningfully predict or understand public attitude relating to a particular issue or concept. The fluoridation of community water supplies was chosen for the present methodological demonstration. This issue achieves a high level of controversy among many public segments [Crain, Katz and Rosenthal, 1969; Davis, 1959; McNeal, 1957]. By 1950, there was widespread endorsement for a national program relating to controlled water fluoridation. Yet, public acceptance of this particular technological advance has not been very high.     

Landscape Patterns of Florida Scrub Jay Habitat Use and Demographic Success

Remote sensing and geographical information systems are used to analyze landscapes important to species of conservation concern. The accuracy of the methods depends on how closely habitat mapping classes are linked to population demography. Habitat use by Florida Scrub Jays ( Aphelocoma c. coemlescens ) was quantified using circular plots. Habitat variation was mapped using high-resolution aerial photography on a site where all Florida Scrub Jays were color-banded. Nest site selection, nest success, yearling production, and breeder survival were measured within Florida Scrub Jay territories. Habitat use was lowest in areas without scrub oaks or areas within 136 m from forests. Open oak, dominated by scrub oaks and open sandy areas, had the highest use and nest success among habitats. Open oak occurred as narrow patches ( <20 m wide) in landscapes dominated by matrix habitat (palmetto-lyonia and swale marshes). Most wide patches (>50 m) of open oak were potential population sources, where reproduction exceeded mortality. Areas with patches of open oak of less than 1 ha were usually population sinks. Open oak occurred as less flammable patches in a landscape subject to frequent fires. Population sources varied temporally and spatially with fires and site potential to support scrub oaks (soils). Analyses of landscape patterns and dynamics indicated that habitat mapping should not only include patches of currently optimal habitat but should also include landscapes associated with open oak. The influences of landscape patterns on habitat use, reproductive success, survival, and territory size can be quantified at different scales starting with attributes associated with habitat patches, nest sites, and territories. Potential mapping errors occur, however, when habitats are used to quantify the areal extent of sources and sinks and similar population attributes important for species persistence.     

Association between older driver characteristics, on-road driving test performance, and crash liability

From May 1999, a new system for licensing older drivers was introduced in New Zealand. It included a practical on-road driving test with expanded scope, to be completed every two years from the time the driver turns 80. The relationship between crashes and test performance needed to be studied to inform the debate regarding the testing system. The population studied was all drivers who entered this licensing system during its first three years of operation. They were defined as crash involved if they were involved in an injury crash during the two years following their first licensure under the new system. Logistic regression was used to describe the risk of crash involvement in terms of driving test performance and other driver characteristics. Each driving test failure was associated with a 33% increase in the odds of crash involvement (95% CI 14% to 55%), controlling for age, gender, minor traffic violations, and whether the older driver lived with another licensed driver or not. Minor traffic violations in the two years following the driving test were associated with twice the odds of crash involvement. These results suggest that the new on-road driving test does identify older driver behaviors or limitations that are related to crash liability. It is anticipated that the results presented here will provide essential information for discussing older driver licensing systems, whose impact will grow in importance as the population of drivers ages.     

Monitoring Forest Carbon Sequestration with Remote Sensing and Carbon Cycle Modeling

Sources and sinks of carbon associated with forests depend strongly on the management regime and spatial patterns in potential productivity. Satellite remote sensing can provide spatially explicit information on land cover, stand-age class, and harvesting. Carbon-cycle process models coupled to regional climate databases can provide information on potential rates of production and related rates of decomposition. The integration of remote sensing and modeling thus produces spatially explicit information on carbon storage and flux. This integrated approach was employed to compare carbon flux for the period 1992–1997 over two 165-km² areas in western Oregon. The Coast Range study area was predominately private land managed for timber production, whereas the West Cascades study area was predominantly public land that was less productive but experienced little harvesting in the 1990s. In the Coast Range area, 17% of the land base was harvested between 1991 and 2000. Much of the area was in relatively young, productive-age classes that simulations indicate are a carbon sink. Mean annual harvest removals from the Coast Range were greater than mean annual net ecosystem production. On the West Cascades study area, a relatively small proportion (< 1%) of the land was harvested and the area as a whole was accumulating carbon. The spatially and temporally explicit nature of this approach permits identification of mechanisms underlying land base carbon flux. Published online     

ENHANCING EVACUATION WARNING COMPLIANCE: SUGGESTIONS FOREMERGENCY PLANNING*

This review of incentives to evacuate is meaningful largely in the context of planning for and managing the consequences of the impact of riverine floods. Of course, incentives do not constitute an emergency plan. At best, they should be seen as suggestions for structuring some elements of a plan. Furthermore, the enumeration of incentives presented here is meant to be suggestive rather than exhaustive. A primary objective of this paper has been to underscore the importance of advance planning in coping with hazards and to argue that, even though limited, existing research can be productively used in the planning process. The incentives described here are based upon or drawn from empirical research on people's performance under flood disaster conditions. This reflects the view that it is important to build emergency planning around people's known reaction patterns. Too often emergency plans which are administratively devised turn out to be based upon misconceptions of how people react (cf. Drabek and Stephenson, 1971, p. 202; Dynes et al., 1972, p. 31) and, therefore, potentially create more difficulties than they solve. One must be cautioned, however, that although our data indicate that people say they would support the idea of various evacuation incentives examined here, these are attitudinal data and not performance data. Thus, the real test of evacuation incentives lies in their implementation and in evaluation data on pilot programs which, unfortunately, do not presently exist. The outlook for the feasibility of developing and utilizing evacuation incentives appears to be positive, though, judging from responses to our interviews. In the final analysis, it would appear to be wise to develop emergency plans which guide and channel citizen actions into complementary and productive protection behavior patterns. The present discussion of incentives to evacuate is intended to encourage data-based emergency planning.     

DYNAMIC PROGRAMMING FOR OPTIMAL CAPACITY EXPANSION OF WASTEWATER TREATMENT PLANTS1

ABSTRACT: A dynamic programming procedure for the planning and operation of a wastewater treatment plant over a long period of time is presented. In order to meet increased demands for wastewater treatment in the future, the expansion of existing plants must be considered. Dynamic programming is employed to determine the optimal schedule of expansion at each plant, simultaneously determining an optimal operating policy (treatment level). The optimal schedule of expansion at each plant depends on the following: (1) the shape of the projected wastewater demand function; (2) the interest rate used; (3) the locations and capacities of the facilities available; and (4) the rates of increase of the costs of construction, labor, chemicals, and electric power. An example illustrating the use of the procedure is presented.