Genetic control and evolution of acoustic signals in planthoppers (Homoptera: Delphacidae)

Acoustic signals are part of the specific mate recognition system of planthoppers. The genetic control of acoustic signal characters was studied in the planthopperRibautodelphax imitans. Artificial selection for interpulse interval in the female call revealed a large additive genetic component for this polygenic character. Other female call characters showed a correlated response. Some male call characters also appeared to be genetically correlated with the female character selected for, despite the rather different structure of male and female calls. Parent-offspring regression provided significant heritability estimates for those male call characters that also responded to artificial selection in the female call, one of which appeared to be influenced by sex-linked genes. It is argued that the differentiation of this mate recognition system in planthopper populations and species could be the result of founder effects, enabled by the genetic plasticity of the call characters and the existence of a wing length dimorphism in these animals.     

Land use conflict after the wildlife and countryside act 1981: the role of the farming and wildlife advisory group

As the conflict between agriculture and conservation in Britain continues, the farming and landowning lobby has placed increasing emphasis on the Farming and Wildlife Advisory Group (FWAG). This paper examines the development of FWAG as a mechanism for self-regulation through a voluntary and co-operative approach to conservation within the farming community. FWAG, until recently accorded little attention either by farmers or government, now enjoys considerable patronage, and new-found financial support from the Countryside Commission. As the National Farmers' Union (NFU) and Country Landowners' Association (CLA) seek to contain the tide of criticism of activities in the countryside FWAG, essentially a practical advisory body, has assumed a crucial ideological importance in the presentation of the farmers' traditional case of ‘stewardship’ and ‘good husbandry’. The paper concludes by stressing the dilemma facing the NFU and CLA as they seek to satisfy the wishes of their own members, government and the conservation lobby.     

A product-limit estimator for use with length-biased data

The following life-testing situation is considered. At some time in the distant past, n objects, from a population with life distribution F, were put in use; whenever an object failed, it was promptly replaced. At some time τ, long after the start of the process, a statistician starts observing the n objects in use at that time; he knows the age of each of those n objects, and observes each of them for a fixed length of time? ∞, or until failure, whichever occurs first. In the case where T is finite, some of the observations may be censored; in the case where T =∞, there is no censoring. The total life of an object in use at time ∞ is a length-biased observation from F. A nonparametric estimator of the (cumulative) hazard function is proposed, and is used to construct an estimator of F which is of the product-limit type. Strong uniform consistency results (for n → ∞) are obtained. An “Aalen-Johansen” identity, satisfied by any pair of life distributions and their (cumulative) hazard functions, is used in obtaining rate-of-convergence results.     

Models of accepting an early retirement incentive

The presence of special early retirement incentives has changed the work environment for older workers. It is of interest to know how existing models of the timing of the pension acceptance decision function in an incentive environment. Furthermore, it is of interest to note the similarities or differences between males and females with regard to retirement behaviors. In this study, a basic utility maximization model, an expanded model, and an interactive model are applied to the acceptance of an early retirement pension incentive; probabilities of acceptance range from .18 to .39. Acceptance behavior without the incentive is simulated, with probabilities of acceptance ranging from .11 to .33. Addition of a set of socioeconomic and psychological variables and a vector of interactive variables is found to improve the basic model.The author would like to thank W. Keith Bryant, Olivia Mitchell and several anonymous reviewers for comments on earlier drafts. Any remaining errors are, of course, my own. Acknowledgement is also given to the Cornell University Agricultural Experiment Station for funding assistance.Jeanne M. Hogarth is an associate professor in the Department of Consumer Economics and Housing, Cornell University, Ithaca, NY 14853. Dr. Hogarth received her Ph.D. from The Ohio State University, Department of Family Resource Management and includes retirement decision making, such as the timing of retirement and use of financial resources during retirement, among her current research interests.     

Citizenship and culture: the role of disabled people in Navajo society

Cultural constructs of disabilities can vary from one culture to another and significantly affect how the individual with disabilities is perceived, accepted, and accorded citizenship rights and responsibilities. This anthropological study of Navajo individuals with disabilities investigates these cultural constructs in a non-Western society from the perspective of the Navajo community members. Factors analyzed include child-rearing practices, the Navajo concept of childhood, and Navajo notions of health and unwellness. Historical attitudes toward disabled people are also explored, as well as changing attitudes due to the influence of Western biomedical explanations and interventions.     

Toward a Relational Understanding of Objectification,Body Image,and Preventive Sexual Health

There is a wealth of empirical support for objectification theory. Researchers have suggested an extension to the theory that includes risky sexual behaviors as a consequence of body shame. However, there are no known studies that place the association between body image and sexual behavior in the context of the interpersonal sexual relationship. The current study was grounded in objectification theory and relational cultural theory and sought to better understand how negative self-objectification, body appreciation, relationship quality, and preventive sexual health behaviors are related. An online survey was conducted with 399 emerging adult women in the Midwest, and the proposed model was tested using structural equation modeling (SEM). The results suggest that, among this sample, negative self-objectification was indirectly related to preventive sexual health behaviors through body appreciation alone and through both body appreciation and relationship quality. Implications for clinical practice and future research are discussed.     

Revisiting histories of anti-racist thought and activism

ABSTRACT

This piece reconsiders histories of anti-racist thought and practice, including the linkages between anti-racisms and other traditions of liberatory thought. We argue that anti-racism should be understood as a strand in radical thought linking internationalism, institutional critique and street activism, in the process interfeeding with other social movements. The traditions of anti-racist thought discussed in this special issue exemplify these cross-cutting influences.