Broader Debates (broader + debate)

Distribution by Scientific Domains
Humanities and Social Sciences80%

Selected Abstracts

Biodiversity and biocontrol: emergent impacts of a multi-enemy assemblage on pest suppression and crop yield in an agroecosystem

ECOLOGY LETTERS, Issue 9 2003
Bradley J. Cardinale
Abstract The suppression of agricultural pests has often been proposed as an important service of natural enemy diversity, but few experiments have tested this assertion. In this study we present empirical evidence that increasing the richness of a particular guild of natural enemies can reduce the density of a widespread group of herbivorous pests and, in turn, increase the yield of an economically important crop. We performed an experiment in large field enclosures where we manipulated the presence/absence of three of the most important natural enemies (the coccinellid beetle Harmonia axyridis, the damsel bug Nabis sp., and the parasitic wasp Aphidius ervi) of pea aphids (Acyrthosiphon pisum) that feed on alfalfa (Medicago sativa). When all three enemy species were together, the population density of the pea aphid was suppressed more than could be predicted from the summed impact of each enemy species alone. As crop yield was negatively related to pea aphid density, there was a concomitant non-additive increase in the production of alfalfa in enclosures containing the more diverse enemy guild. This trophic cascade appeared to be influenced by an indirect interaction involving a second herbivore inhabiting the system , the cowpea aphid, Aphis craccivora. Data suggest that high relative densities of cowpea aphids inhibited parasitism of pea aphids by the specialist parasitoid, A. ervi. Therefore, when natural enemies were together and densities of cowpea aphids were reduced by generalist predators, parasitism of pea aphids increased. This interaction modification is similar to other types of indirect interactions among enemy species (e.g. predator,predator facilitation) that can enhance the suppression of agricultural pests. Results of our study, and those of others performed in agroecosystems, complement the broader debate over how biodiversity influences ecosystem functioning by specifically focusing on systems that produce goods of immediate relevance to human society. [source]

Race, Ethnicity, and Racism in Medical Anthropology, 1977,2002

MEDICAL ANTHROPOLOGY QUARTERLY, Issue 1 2008
Clarence C. Gravlee
Researchers across the health sciences are engaged in a vigorous debate over the role that the concepts of "race" and "ethnicity" play in health research and clinical practice. Here we contribute to that debate by examining how the concepts of race, ethnicity, and racism are used in medical,anthropological research. We present a content analysis of Medical Anthropology and Medical Anthropology Quarterly, based on a systematic random sample of empirical research articles (n =283) published in these journals from 1977 to 2002. We identify both differences and similarities in the use of race, ethnicity, and racism concepts in medical anthropology and neighboring disciplines, and we offer recommendations for ways that medical anthropologists can contribute to the broader debate over racial and ethnic inequalities in health. [source]

Integrating Gender Interests into Health Policy

DEVELOPMENT AND CHANGE, Issue 2 2006
Jasmine Gideon
This article reviews current initiatives to integrate gender interests into health policy in Chile. The analysis outlines the debates that have arisen around the questions of mainstreaming gender, in relation to state institutions, NGOs and grassroots organizations. The discussion highlights both the constraints and opportunities identified in the literature. The study locates the Chilean case study within these broader debates and draws some overall conclusions. Despite the limitations posed by the broader context of neo-liberal health sector reforms, the experience of the Chilean gender mainstreaming initiative does suggest that there is some cause for optimism. [source]

Narratives of nationalism in Eritrea: research and revisionism*

NATIONS AND NATIONALISM, Issue 2 2005
2003), Dedicated to the memory of Alex Naty (195
Eritrean politics is increasingly captured in competing narratives of nationalism. ,Official' narratives emphasize Eritrea's purported stability, orderliness, and uniqueness. This discourse defends and supports the current government's policies. In contrast, recent research challenges those policies, and contributes to a nationalist counter-narrative. This article seeks to investigate the discursive power of conventional narratives and the implications of new research for accounts of state and nation-building in Eritrea. The Eritrean case , one of the newest states in the world , intersects with and informs a number of broader debates on nationalism and nation-building: the impact of globalization, secessionism, and war as well as the relationship between ethnicity and nationalism. The penetration of state and nation-building projects into every sector of Eritrean life means that all social research is deeply politicised. Journalists and researchers have long been key players in the contested process of conceptualising Eritrean nation-hood, and this continues in the post-liberation period. Research thus both buttresses and challenges official discourses, even where it is not explicitly framed in terms of nationalism. [source]

Household diversity and migration in mid-life: understanding residential mobility among 45,64 year olds in Melbourne, Australia

POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 4 2010
Maryann Wulff
Abstract This paper focuses on the residential mobility of middle-aged persons, not yet retired, an understudied cohort in mobility research. From the 1950s to the 1980s, mobility studies pointed to mid-life as a settled stage in terms of family, work and housing. Recent demographic and social changes, however, have led to these years being typified by a wide gamut of living arrangements that have complicated decisions about, and patterns of, residential mobility. Using the life-course perspective, this paper suggests that the transition to ,empty nester' status will heighten mobility among this group of middle-aged persons relative to their counterparts in other living arrangements. The analysis uses a customised migration matrix from the Australian 2006 Census and identifies segments of 45,64 year olds most likely to have changed address since the previous census in 2001. CHAID statistical method partitioned the 45,64 year old population in Melbourne, Australia, into eight statistically significant segments based on life-course factors and mobility levels. Younger (45,54 years) mid-life empty-nesters changed residence at 1.4 times the mobility rate of all mid-life persons. For couples in this age group, empty nest status conferred a 13 percentage point ,mobility premium' compared with couples that still had children at home. The results contribute to a better understanding of housing consumption among mid-life households and broader debates on access to affordable housing and processes of urban growth. Copyright © 2009 John Wiley & Sons, Ltd. [source]