Subglacial topography and geothermal heat flux: potential interactions with drainage of the Greenland ice sheet

This is the published version, also available here: http://dx.doi.org/10.1029/2007GL030046.[1] Many of the outlet glaciers in Greenland overlie deep and narrow trenches cut into the bedrock. It is well known that pronounced topography intensifies the geothermal heat flux in deep valleys and attenuates this flux on mountains. Here we investigate the magnitude of this effect for two subglacial trenches in Greenland. Heat flux variations are estimated for idealized geometries using solutions for plane slopes derived by Lachenbruch (1968). It is found that for channels such as the one under Jakobshavn Isbræ, topographic effects may increase the local geothermal heat flux by as much as 100%

Improving the Quality of Child Care in the Rural South

A collaborative of six social service agencies and a state university determined that the single most pressing need of families in a 14-county, rural area was child care. The Training Resource Center, developed through a W K. Kellogg Foundation grant, worked with day care licensing and early childhood professional groups to develop a plan to address the systemic nature of the problem of how to improve the quality of child care. Programs developed included training, mentoring, NAEYC accreditation, and a resource library. After 15 months, some programs show the possibility of sustainability

Accentuating the positive and eliminating the negative: Efficacy of TiO2 as digestibility index marker for poultry nutrition studies

Inert digestibility index markers such as titanium dioxide are universally accepted to provide simple measurement of digestive tract retention and relative digestibility in poultry feeding trials. Their use underpins industry practice: specifically dosing regimens for adjunct enzymes added to animal feed. Among these, phytases, enzymes that degrade dietary phytate, inositol hexakisphosphate, represent a billion-dollar sector in an industry that raises ca. 70 billion chickens/annum. Unbeknown to the feed enzyme sector, is the growth in cell biology of use of titanium dioxide for enrichment of inositol phosphates from extracts of cells and tissues. The adoption of titanium dioxide in cell biology arises from its affinity under acid conditions for phosphates, suggesting that in feeding trial contexts that target phytate degradation this marker may not be as inert as assumed. We show that feed grade titanium dioxide enriches a mixed population of higher and lower inositol phosphates from acid solutions. Additionally, we compared the extractable inositol phosphates in gizzard and ileal digesta of 21day old male Ross 308 broilers fed three phytase doses (0, 500 and 6000 FTU/kg feed) and one inositol dose (2g/kg feed). This experiment was performed with or without titanium dioxide added as a digestibility index marker at a level of 0.5%, with all diets fed for 21 days. Analysis yielded no significant difference in effect of phytase inclusion in the presence or absence of titanium dioxide. Thus, despite the utility of titanium dioxide for recovery of inositol phosphates from biological samples, it seems that its use as an inert marker in digestibility trials is justified—as its inclusion in mash diets does not interfere with the recovery of inositol phosphates from digesta samples

Adaptation to divergent larval diets in the medfly, Ceratitis capitata

Variation in diet can influence the timing of major life history events and can drive population diversification and ultimately speciation. Proximate responses of life histories to diet have been well studied. However, there are scant experimental data on how organisms adapt to divergent diets over the longer term. We focused on this omission by testing the responses of a global pest, the Mediterranean fruitfly, to divergent selection on larval diets of different nutritional profiles. Tests conducted before and after 30 generations of nutritional selection revealed a complex interplay between the effects of novel larval dietary conditions on both plastic and evolved responses. There were proximate-only responses to the larval diet in adult male courtship and the frequency of copulation. Males on higher calorie larval diets consistently engaged in more bouts of energetic courtship. In contrast, following selection, larval development time and egg to adult survival showed evidence of evolved divergence between diet regimes. Adult body size showed evidence for adaptation, with flies being significantly heavier when reared on their ‘own’ diet. The results show the multifaceted responses of individuals to dietary selection and are important in understanding the extreme generalism exhibited by the medfly

Historical institutionalism and the politics of sustainable energy transitions: a research agenda

Improving the understanding of the politics of sustainable energy transitions has become a major focus for research. This paper builds on recent interest in institutionalist approaches to consider in some depth the agenda arising from a historical institutionalist perspective on such transitions. It is argued that historical institutionalism is a valuable complement to socio-technical systems approaches, offering tools for the explicit analysis of institutional dynamics that are present but implicit in the latter framework, opening up new questions and providing useful empirical material relevant for the study of the wider political contexts within which transitions are emerging. Deploying a number of core concepts including veto players, power, unintended consequences, and positive and negative feedback in a variety of ways, the paper explores research agendas in two broad areas: understanding diversity in transition outcomes in terms of the effects of different institutional arrangements, and the understanding of transitions in terms of institutional development and change. A range of issues are explored, including: the roles of electoral and political institutions, regulatory agencies, the creation of politically credible commitment to transition policies, power and incumbency, institutional systems and varieties of capitalism, sources of regime stability and instability, policy feedback effects, and types of gradual institutional change. The paper concludes with some observations on the potential and limitations of historical institutionalism, and briefly considers the question of whether there may be specific institutional configurations that would facilitate more rapid sustainable energy transitions

Clear purpose or sheer survival? National ministerial leadership across multiple arenas

Day-to-day political life for the most senior national politicians can be very pressurized and exposed. How they as individuals cope with constant challenges and make the most of opportunities for leadership is an under researched area. This is addressed in this interpretive study of the personal accounts of a small group of prominent U.K. politicians as they reflect, soon after leaving office, on their experiences as national ministers. The article connects generic leadership theory around practice and purpose with political leadership studies as a basis for a thematic analysis of ministers’ experiences across three key prominent arenas of ministerial life: relationships with the Prime Minister’s office, within their departments, and with their constituencies. Analysis of findings leads to a proposed analytical framework of active leadership in their everyday experience. The article concludes that active leadership practice is difficult but possible for leading national politicians