Environmental Information Systems in Malaria Risk Mapping and Epidemic Forecasting

Every year between one and two million African children under five die of malaria. If one adds to this the contribution of malaria to all-cause infant mortality then clearly the burden of the disease is catastrophic — a disaster quietly happening each and every year. New tools are needed urgently to support those currently available for control of the disease. An effective vaccine remains elusive. This article outlines the potential contribution to malaria control services of satellite information, which is being used by resource managers in other sectors. In particular, it highlights the lessons which can be learned from early warning systems in other areas, especially those designed to respond to famine. An appendix provides a brief introduction to satellite data and their interpretation.     

Fluoride in the prey of barn owls (Tyto alba)

Bone fluoride in short-tailed voles (Microtus agrestis) and common shrews (Sorex araneus), the prey of barn owls (Tyto alba), was studied on Anglesey, North Wales. The average fluoride content of M. agrestis skulls obtained from a location 0.9 km from an aluminium reduction plant was significantly greater than that of skulls from another location 22 km from the source of industrial fluoride pollution. At both locations, mean fluoride levels of skulls extracted from owl pellets and those of voles trapped mechanically were broadly similar but important differences existed. Near the aluminium reduction plant, owls caught voles and shrews with a much wider range of fluoride levels than occurred at a single trapping site. However, there was no evidence for selection of heavily fluoridated prey. Within 1 km of the aluminium reduction plant, six trapping sites yielded S. araneus with a fourfold difference between the highest and lowest mean bone fluoride level.     

Protégé selection by mentors: what makes the difference?

This study examined protégé characteristics that mentors reported were most influential when choosing a protégé. Based on existing research, two variables were identified related to protégé selection: perceptions regarding the protégé's potential/ability and perceptions regarding the protégé's need for help. The relationships of these two factors with perceived barriers to mentoring others, mentor advancement aspirations, and mentor gender were investigated. Data from 282 mentors revealed that mentors were more likely to choose a protégé based on perceptions regarding the protégé's ability/potential than based on perceptions regarding the protégé's need for help. Additionally, women were more likely to choose a protégé based on the protégé's perceived ability than were men. Copyright © 2000 John Wiley & Sons, Ltd.     

Does participative leadership enhance work performance by inducing empowerment or trust? The differential effects on managerial and non‐managerial subordinates

We examined whether participative leadership behavior is associated with improved work performance through a motivational process or an exchange‐based process. Based on data collected from 527 employees from a Fortune 500 company, we found that the link between superiors' participative leadership behaviors and subordinates' task performance and organizational citizenship behavior toward organizations (OCBO) was mediated by psychological empowerment (motivational mediator) for managerial subordinates. Yet, for non‐managerial subordinates such as supporting and front‐line employees, the impact of participative leadership on task performance and OCBO was mediated by trust‐in‐supervisor (exchange‐based mediator). Implications for theories and practices are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Learning and development factors related to perceptions of job content and hierarchical plateauing

This study applied theory from the employee learning and development literature to examine factors related to employees' perceptions of being job content plateaued and hierarchically plateaued. Results indicated that both types of plateauing were related to support from top management, career planning, job involvement, and education level. Furthermore, career exploration, motivation to learn, organizational tenure, and job tenure were related to perceptions of hierarchical plateauing, while supervisor support was related to job content plateauing. Additionally, the two types of plateauing differed in the relative strength of their relationship with the variables studied. Implications and future research suggestions are provided. Copyright © 1999 John Wiley & Sons, Ltd.     

Will progress in science and technology avert or accelerate global collapse? A critical analysis and policy recommendations

Industrial society will move towards collapse if its total environmental impact (I), expressed either in terms of energy and materials use or in terms of pollution, increases with time, i.e., dI/dt > 0. The traditional interpretation of the I = PAT equation reflects the optimistic belief that technological innovation, particularly improvements in eco-efficiency, will significantly reduce the technology (T) factor, and thereby result in a corresponding decline in impact (I). Unfortunately, this interpretation of the I = PAT equation ignores the effects of technological change on the other two factors: population (P) and per capita affluence (A). A more heuristic formulation of this equation is I = P(T)·A(T)·T in which the dependence of P and A on T is apparent. From historical evidence, it is clear that technological revolutions (tool-making, agricultural, and industrial) have been the primary driving forces behind successive population explosions, and that modern communication and transportation technologies have been employed to transform a large proportion of the world’s inhabitants into consumers of material- and energy-intensive products and services. In addition, factor analysis from neoclassical growth theory and the rebound effect provide evidence that science and technology have played a key role in contributing to rising living standards. While technological change has thus contributed to significant increases in both P and A, it has at the same time brought about considerable eco-efficiency improvements. Unfortunately, reductions in the T-factor have generally not been sufficiently rapid to compensate for the simultaneous increases in both P and A. As a result, total impact, in terms of energy production, mineral extraction, land-use and CO₂ emissions, has in most cases increased with time, indicating that industrial society is nevertheless moving towards collapse. The belief that continued and even accelerated scientific research and technological innovation will automatically result in sustainability and avert collapse is at best mistaken. Innovations in science and technology will be necessary but alone will be insufficient for sustainability. Consequently, what is most needed are specific policies designed to decrease total impact, such as (a) halting population growth via effective population stabilization plans and better access to birth control methods, (b) reducing total matter-energy throughput and pollution by removing perverse subsidies, imposing regulations that limit waste discharges and the depletion of non-renewable resources, and implementing ecological tax reform, and (c) moving towards a steady-state economy in which per-capita affluence is stabilized at lower levels by replacing wasteful conspicuous material consumption with social alternatives known to enhance subjective well-being. While science and technology must play an important role in the implementation of these policies, none will be enacted without a fundamental change in society’s dominant values of growth and exploitation. Thus, value change is the most important prerequisite for avoiding global collapse.

Response of “Alamo” switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee,USA

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha^?1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ± 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha^?1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.     

Social information use is a process across time, space, and ecology, reaching heterospecifics

Decision making can be facilitated by observing other individuals faced with the same or similar problem, and recent research suggests that this social information use is a widespread phenomenon. Implications of this are diverse and profound: for example, social information use may trigger cultural evolution, affect distribution and dispersal of populations, and involve intriguing cognitive traits. We emphasize here that social information use is a process consisting of the scenes of (1) event, (2) observation, (3) decision, and (4) consequence, where the initial event is a scene in such a process of another individual. This helps to construct a sound conceptual framework for measuring and studying social information use. Importantly, the potential value of social information is affected by the distance in time, space, and ecology between the initial observation and eventual consequence of a decision. Because negative interactions between individuals (such as direct and apparent competition) also depend on the distance between individuals along these dimensions, the potential value of information and the negative interactions may form a trade-off situation. Optimal solutions to this trade-off can result in adaptively extended social information use, where using information gathered some time ago, some distance away, and from ecologically different individuals is preferred. Conceivably, using information gathered from a heterospecific individual might often be optimal. Many recent studies demonstrate that social information use does occur between species, and the first review of published cases is provided here. Such interaction between species, especially in habitat selection, has important consequences for community ecology and conservation. Adaptively extended social information use may also be an important evolutionary force in guild formation. Complex coevolutionary patterns may result depending on the effect of information use on the provider of information.     

Do source-sink dynamics promote the spread of an invasive grass into a novel habitat?

Models of source-sink and other spatial patch dynamics have generated a number of ideas and predictions about species range expansion, the evolution of local adaptation, and the factors influencing population persistence, but relatively few empirical studies have applied these ideas due to the difficulty of measuring both patch-specific demography and movement rates. In this study, I used a combination of mark-recapture experiments, model fitting, and demographic approaches to ask how habitat-specific differences in population growth and dispersal affect spread of the invasive grass Aegilops triuncialis into serpentine environments. A. triuncialis germinated at lower rates but exhibited equivalent survival and greater growth in edge (extreme serpentine) than in core populations, even accounting for density differences between habitats. Estimated growth rates (lambda) for four of five edge subpopulations were strongly positive, ranging from lambda = 1.32 to 2.09 without propagule input from adjacent habitat. Local dispersal was best described by an exponential kernel, with a mean dispersal distance about twice as long on the edge (0.24-0.40 m) as in the core (0.18 m). Twenty-five percent of marked spikes in the edge were not relocated within the patch, suggesting greater rates of either seed predation or long-distance dispersal that reduced population growth. These results suggest that A. triuncialis can successfully spread into extreme serpentine habitats without sustained propagule input from adjacent populations. Further, asymmetric dispersal that may be both habitat- and density-dependent could slow growth rates on the edge. This pattern may also increase the importance of harsh edge patches as a source of long-distance dispersers.