Raccoon use of the urban matrix in the Baltimore Metropolitan Area, Maryland

The raccoon is often considered a synanthropic species; however, most urban research on this species has been restricted to urban parks or green spaces. Little is known about the persistence of synanthropic characteristics in the raccoon within the urban matrix. We examined density, den selection, home range size, habitat selection, and survival for adult raccoons (Procyon lotor) during summer (June?CAugust) and autumn (September?CNovember) in two residential neighborhoods, Linthicum located inland, and Riviera Beach on a peninsula in the Potomac river, in Southern Maryland. Den site selection varied by gender (P?=?0.0002) and study site (P?=?0.052), and study site interacted with gender (P?=?0.0063), with female raccoons denning preferentially on the ground and male raccoons in human structures in Riviera Beach while in Linthicum females denned preferentially in trees and males avoided human structures. Seasonal home range size was larger for males (P?<?0.0001) than females at both sites. Habitat selection varied at different hierarchical levels, and between gender, season and site. Intersite differences in habitat selection were apparent at the second order and third order scale. Aquatic and urban habitat was ranked high and woodland consistently lowest in second order scale at Riviera Beach while urban habitat was consistently ranked lowest at Linthicum where woodland ranked highest. Between the hierarchal scales (2nd and 3rd order) a difference in habitat selection occurred at Linthicum only where urban habitats ranked lowest at 3rd order. The differences in patterns of habitat selection we observed between two urban sites at different hierarchical scales suggest that resource selection is dependent upon the specific characteristics of the site and that raccoons exhibit variable responses to changes in landscape features. Finally, male survival tended to be lower (P?=?0.079) than female survival in both study sites. Our results reveal that raccoons can continue to exhibit synanthropic characteristics within the urban matrix even in areas with little natural habitat. This ability to adjust to different levels of development allows the raccoon to occur throughout most parts of the urban landscape, which has important management implications for human-raccoon conflicts and disease management.     

The politic,philosophy and practice of OR—A personal view of the issues

It is almost 50 years since Sir Henry Tizzard created the group of scientists in RAF Fighter Command who were to coin the term ‘Operational Research’. The group still exists, though its work, and the work of other defence OR groups, has changed from solving acute operational problems by the extrapolation of observed data, to an attempt at predicting the outcome of policy choices that are beyond experience. Inevitably this has forced OR further into a political arena. Yet most OR practitioners are scientists used to investigating apolitical and benign nature. In this paper the author gives a personal view of what he believes OR is trying to achieve, what practical problems and pressures have to be faced and attempts to give guidance on how to proceed.     

Family factors in child care research

The purpose of this article is to review evidence concerning the joint impact of family characteristics and child care experiences in understanding children's development. Although child care experiences are related to children's development across a variety of domains, family characteristics, particularly socioeconomic status and parenting quality, are typically stronger predictors of children's outcomes. An important implication of these findings is that high-quality child care experiences are likely to have stronger effects on children who are at risk of poorer outcomes because of less optimal family environments; evidence from experimental and nonexperimental studies generally supports this conclusion. From a policy perspective, an important goal for future research is to identify subgroups of families within the heterogeneous low-income population that are in particular need of relatively more intensive services and to develop effective interventions that are tailored to their needs.     

System dynamics: Portraying bounded rationality

This paper examines the linkages between system dynamics and the Carnegie School in their treatment of human decision making. It is argued that the structure of system dynamics models implicitly assumes bounded rationality in decision making and that recognition of this assumption would aid system dynamicists in model construction and in communication with other social science disciplines. The paper begins by examining Simon's ‘principle of bounded rationality’ which draws attention to the cognitive limitations on the information gathering and processing powers of human decision makers. Forrester's ‘Market Growth Model’ is used to illustrate the central theme that system dynamics models are portrayals of bounded rationality. Close examination of the model formulation reveals decision functions involving simple rules of thumb and limited information content. Finally, there is a discussion of the implications of Carnegie philosophy for system dynamics as it affects communication, model structuring, model analysis and future research.     

Screening and brief intervention for alcohol problems among college students treated in a university hospital emergency department

The authors evaluated a protocol to screen and provide brief interventions for alcohol problems to college students treated at a university hospital emergency department (ED). Of 2,372 drinkers they approached, 87% gave informed consent. Of those, 54% screened positive for alcohol problems (Alcohol Use Disorders Identification Test score < or = 6). One half to two thirds of the students who screened positive drank 2 to 3 times a week, drank 7 or more drinks per typical drinking day, or had experienced alcohol dependence symptoms within the past year. Ninety-six percent of screen-positive students accepted counseling during their ED visit. Three quarters of those questioned at 3-month follow-up reported that counseling had been helpful and that they had decreased their alcohol consumption. The prevalence of alcohol problems, high rates of informed consent and acceptance of counseling, and improved outcomes suggest that the ED is an appropriate venue for engaging students at high risk for alcohol problems.