Effects of sterile insect releases on a population under predation or parasitism

Summary A continuous-time differential equation model was constructed which describes the population dynamics of a predator prey system in which sterile prey are released in a program designed to eradicate or reduce the prey population. It was found that the dynamics of the system behave quite differently when predators are present. Two conditions were found which have differing implications for the control program. If the predators still exist when the wild prey population declines to extinction, then the SIRM is assisted by the predators, sometimes to a considereble extent. If the predators decline to extinction before the wild prey population goes extinct, then the predators may or may not assist the SIRM depending on the parameters of the system. If the predators do assist the SIRM, then a potentially dangerous situation exists in which an explosion of the prey population could occur after the predators go extinct. Predator polyphagy would probably minimize this danger of an explosion since it would stabilize the predator population.     

Social Conflict: Implications for Casework Practice

Summary The concept of social conflict is examined in terms of its usefulnessin refining and extending social casework theory. Attentionis given to the influence of the homeostatic approach to caseworkpractice versus an approach utilizing a conflict orientation.Primary emphasis is given to Coser's sociological theory ofconflict in an effort to discover heuristic concepts which areconsidered to be applicable in the practice of social casework.Specifically, seven of Coser's original sixteen propositionsrelated to conflict theory have been selected for analysis.It is concluded that a conflict orientation would serve to clarifythe functional aspects of conflict as they relate to the dyadiccasework relationship     

DIVERSIFICATION GAINS FROM INCLUDING REAL ESTATE IN MIXED-ASSET PORTFOLIOS*

Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media.     

New Voices in Defence of Aid

Book reviewed in this article: Foreign Aid Reconsidered. By Roger C. Riddell. Overseas Aid: Its Defence and Reform. By Paul Mosley. Missed Opportunities: Britain and the Third World. By Charles Elliott et al.     

Economic Adversity and Voter Turnout: Evidence from Turkish Parliamentary Elections

Social Indicators Research - This paper investigates the relationship between economic adversity and voter participation in Turkish parliamentary elections. We employ a dynamic model of voter...     

THE EFFECT OF MASCULINE AND FEMININE BRAND NAMES ON THE PERCEIVED TASTE OF A CIGARETTE *

The purpose of the current study was to determine whether brand name can affect the public's evaluation of a product. All subjects smoked identical cigarettes. One group of subjects, however, knew the cigarettes by the name of “Frontiersman,” a masculine name, while the other group knew the cigarettes as “April,” a feminine name. Male and female subjects were asked to rate the cigarette on seven measures. Results show that women gave a more positive evaluation to the cigarette purportedly named “April,” while men gave a more positive evaluation to the identical cigarette when they thought it was named “Frontiersman.” In addition, women reacted more strongly than did men to brand name influence.     

Récession,austérité et genre: étude comparative sur huit marchés du travail européens

Si l'effondrement du PIB consécutif à la crise économique mondiale de 2008 a nui avant tout à l'emploi des hommes, les politiques d'austérité auraient davantage affecté celui des femmes. L'auteure cherche à vérifier ce scénario dans huit pays européens, en décomposant la variation trimestrielle du taux d'activité et du taux d'emploi des femmes et des hommes à l'échelon sectoriel. Elle montre que l'association entre he‐cession et she‐austerity ne se confirme pas toujours, mais que les politiques d'austérité peuvent nuire à l'égalité des sexes et aux droits de la femme par d'autres mécanismes d'action, qu'elle répertorie et commente.     

Urban hazards: spatial ecology and survivorship of a turtle in an expanding suburban environment

Urban Ecosystems - Urbanization poses a threat to long-lived vertebrates, particularly from road mortalities that can threaten population persistence. We studied movements, behavior and...