A NEW APPROACH FOR ASSESSING THE COSTS OF LIVING WITH WILDLIFE IN DEVELOPING COUNTRIES

The costs of living with wildlife are assessed using Namibian subsistence farmers willingness to pay (WTP) for deterrents to attacks on crops and livestock as a measure of damage costs. A utility-theoretic approach jointly estimates household WTP for deterrent programs in two currencies, maize and cash. This has a double payoff. Use of a noncash staple increases respondent comprehension and provides more information about preferences, improving the accuracy of results. The household shadow value of maize is also identified. Significant costs from living with elephants and other types of wildlife are demonstrated. Compensation for farmers may be warranted on equity and efficiency grounds. Uncontrolled domestic cattle generate even higher costs to farmers than wildlife, highlighting the need to clarify property rights among these farmers.Resource /Energy Economics and Policy,

Oxidative DNA damage in mild cognitive impairment and late-stage Alzheimer's disease

Increasing evidence supports a role for oxidative DNA damage in aging and several neurodegenerative diseases including Alzheimer's disease (AD). Attack of DNA by reactive oxygen species (ROS), particularly hydroxyl radicals, can lead to strand breaks, DNA–DNA and DNA–protein cross-linking, and formation of at least 20 modified bases adducts. In addition, α,β-unsaturated aldehydic by-products of lipid peroxidation including 4-hydroxynonenal and acrolein can interact with DNA bases leading to the formation of bulky exocyclic adducts. Modification of DNA bases by direct interaction with ROS or aldehydes can lead to mutations and altered protein synthesis. Several studies of DNA base adducts in late-stage AD (LAD) brain show elevations of 8-hydroxyguanine (8-OHG), 8-hydroxyadenine (8-OHA), 5-hydroxycytosine (5-OHC), and 5-hydroxyuracil, a chemical degradation product of cytosine, in both nuclear and mitochondrial DNA (mtDNA) isolated from vulnerable regions of LAD brain compared to age-matched normal control subjects. Previous studies also show elevations of acrolein/guanine adducts in the hippocampus of LAD subjects compared to age-matched controls. In addition, studies of base excision repair show a decline in repair of 8-OHG in vulnerable regions of LAD brain. Our recent studies show elevated 8-OHG, 8-OHA, and 5,6-diamino-5-formamidopyrimidine in both nuclear and mtDNA isolated from vulnerable brain regions in amnestic mild cognitive impairment, the earliest clinical manifestation of AD, suggesting that oxidative DNA damage is an early event in AD and is not merely a secondary phenomenon

Oxidative DNA Damage in Mild Cognitive Impairment and Late-Stage Alzheimer\u27s Disease

Increasing evidence supports a role for oxidative DNA damage in aging and several neurodegenerative diseases including Alzheimer\u27s disease (AD). Attack of DNA by reactive oxygen species (ROS), particularly hydroxyl radicals, can lead to strand breaks, DNA–DNA and DNA–protein cross-linking, and formation of at least 20 modified bases adducts. In addition, α,β-unsaturated aldehydic by-products of lipid peroxidation including 4-hydroxynonenal and acrolein can interact with DNA bases leading to the formation of bulky exocyclic adducts. Modification of DNA bases by direct interaction with ROS or aldehydes can lead to mutations and altered protein synthesis. Several studies of DNA base adducts in late-stage AD (LAD) brain show elevations of 8-hydroxyguanine (8-OHG), 8-hydroxyadenine (8-OHA), 5-hydroxycytosine (5-OHC), and 5-hydroxyuracil, a chemical degradation product of cytosine, in both nuclear and mitochondrial DNA (mtDNA) isolated from vulnerable regions of LAD brain compared to age-matched normal control subjects. Previous studies also show elevations of acrolein/guanine adducts in the hippocampus of LAD subjects compared to age-matched controls. In addition, studies of base excision repair show a decline in repair of 8-OHG in vulnerable regions of LAD brain. Our recent studies show elevated 8-OHG, 8-OHA, and 5,6-diamino-5-formamidopyrimidine in both nuclear and mtDNA isolated from vulnerable brain regions in amnestic mild cognitive impairment, the earliest clinical manifestation of AD, suggesting that oxidative DNA damage is an early event in AD and is not merely a secondary phenomenon

Field Electron Emission of Hafnium Carbide

Hafnium carbide, or HfC, is a robust material whose high melting point makes it an advantageous electron source for a variety of uses, including imaging. This research focused on the effects of an applied field at high temperature on HfC crystals, which induces a faceting effect over time. The cause of this faceting was studied to determine whether it could be correlated to evaporation or self-diffusion during use. The method for electrochemically etching hafnium carbide cathodes was also optimized, and the crystallographic geometry of the tip surfaces was studied using field emission microscopy

Factors affecting engagement and talent development in a school-based sports program

University of Technology Sydney. Faculty of Health.School-based sports programs provide important early sports experiences for children and young athletes, with opportunities to participate in recreational sport, or invest in developing skills required to achieve excellence. However, the suitability of school programs to balance long-term sports engagement with opportunities to develop excellence is not yet known. Four related studies were used to investigate the factors influencing sports participation and talent development in a school-based sports program. Firstly, in a cohort of 501 adolescent sport participants from 25 different sports, Study 1 showed physical and motor competence profiles to be very similar between sports in young athletes, before becoming more heterogeneous with increasing age. Participants at higher levels of competition also reported a delayed engagement in their primary sport. Study 2 employed a multidimensional approach to examine the factors influencing talent selection in adolescent soccer players (N=214), revealing fitness, technical ability and motor competence to be important for talent selection, while players seemed to be guided into playing positions based on maturation, anthropometry and physical performance. Study 3 employed a mixed model approach to examine the factors influencing match activity in youth soccer, showing playing level, playing position and individual fitness characteristics to all influence both match running and skill involvements during match-play. Finally, Study 4 employed a two-year cohort-longitudinal design (N=172), showing players selected into lower playing levels to be more likely to drop out of the school-based soccer program. Additionally, the program did not seem to support retention of motor competence. Collectively, these studies suggest development opportunities may be confounded by the talent selection process, and the school environment may not be suitable for the retention of motor competence. However, schools may also provide an ideal setting to implement a sampling pathway, which may be the most suitable for early sports involvement, improving motor competence, long-term engagement, and development of excellence