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Selected AbstractsPRECISION OF HERBIVORE TOLERANCE EXPERIMENTS WITH IMPOSED AND NATURAL DAMAGEEVOLUTION, Issue 3 2003Kari Lehtilä Abstract Tiffin and Inouye (2000) discussed the use of natural and imposed (controlled) damage in experiments of herbivore tolerance. They constructed a statistical model of the effect of herbivory on plant fitness, including damage level and an environmental factor as the independent factors, in which tolerance is defined as a slope of the regression line when damage level is regressed with plant fitness. They claim that while experiments with imposed damage are more accurate (i.e., they give a more correct estimate of tolerance), experiments with natural damage are more precise under a wide range of parameter values (i.e., tolerance estimates explain a larger part of variation in fitness). I show, however, that experiments with imposed damage are less precise only when an experimenter uses an experimental design that has weaker statistical power than in experiments with natural herbivory. The experimenter can nevertheless control the damage levels to optimize the experimental designs. For instance, when half of the experimental plants are left undamaged and the other half treated with maximal relevant damage level, experiments with imposed damage are almost always much more precise than experiments with natural damage. [source] A Perspective on UK Productivity PerformanceFISCAL STUDIES, Issue 3 2001Nicholas Crafts Abstract The paper reviews recent UK productivity performance using insights from new growth economics and its embodiment in growth accounting techniques. The sources of the UK labour productivity gap are found to differ across countries; broad capital per worker plays a larger part with regard to France and Germany while innovation matters more compared with the USA. The role of incentive structures is examined and the importance of competition as an antidote to agency problems in UK firms is highlighted. Current UK policy is reviewed and the need to address government as well as market failures is stressed. [source] The economic costs of dementia in Korea, 2002INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2006Guk-Hee Suh Abstract Objective To estimate the economic costs of dementia in 2002 using an economic evaluation model for dementia care. Methods Data were from the Korea National Survey of the Long-Term Care Need (LTC survey) (n,=,5058), two prospective 1-year studies [one clinical trial (n,=,234), one naturalistic community cohort study (n,=,107)], and two epidemiologic community studies for prevalence of dementia (n,=,1037,+,1481). Daily costs and proportions of different levels of institutional service provided were collected from the LTC survey. Resource use in the community included health care services, social care services, out-of-pocket purchase for self-support, caregiver time and missed work of caregiver. Costs in community were calculated based on resource utilization multiplied by the unit costs for each resource. Results Total annual costs of dementia were estimated to be over 2.4 billion US$ for 272,000 dementia sufferers. Costs in community represent 96% of the total annual costs, while costs of informal care and missed work of caregivers were 1.3 billion US$, or 55% of total annual cost. Average annual costs of full time care (FTC) and pre-FTC in community LTC were 44,121 US$ and 13,273 US$ per person, whereas cost per patient who did not need community LTC was 3986 US$. Conclusion Given that the number of dementia sufferers is projected to increase in the near future and that larger part of the costs are subsidized by the government, the economic and social costs of dementia is significant not only for dementia sufferers and their caregivers, but also for society. Copyright © 2006 John Wiley & Sons, Ltd. [source] Assessment of soil erosion hazard and prioritization for treatment at the watershed level: Case study in the Chemoga watershed, Blue Nile basin, EthiopiaLAND DEGRADATION AND DEVELOPMENT, Issue 6 2009W. Bewket Abstract Soil erosion by water is the most pressing environmental problem in Ethiopia, particularly in the Highlands where the topography is highly rugged, population pressure is high, steeplands are cultivated and rainfall is erosive. Soil conservation is critically required in these areas. The objective of this study was to assess soil erosion hazard in a typical highland watershed (the Chemoga watershed) and demonstrate that a simple erosion assessment model, the universal soil loss equation (USLE), integrated with satellite remote sensing and geographical information systems can provide useful tools for conservation decision-making. Monthly precipitation, soil map, a 30-m digital elevation model derived from topographic map, land-cover map produced from supervised classification of a Land Sat image, and land use types and slope steepness were used to determine the USLE factor values. The results show that a larger part of the watershed (>58 per cent of total) suffers from a severe or very severe erosion risk (>80,t,ha,1,y,1), mainly in the midstream and upstream parts where steeplands are cultivated or overgrazed. In about 25 per cent of the watershed, soil erosion was estimated to exceed 125,t,ha,1,y,1. Based on the predicted soil erosion rates, the watershed was divided into six priority categories for conservation intervention and 18 micro-watersheds were identified that may be used as planning units. Finally, the method used has yielded a fairly reliable estimation of soil loss rates and delineation of erosion-prone areas. Hence, a similar method can be used in other watersheds to prepare conservation master plans and enable efficient use of limited resources. Copyright © 2009 John Wiley & Sons, Ltd. [source] Welfare state and women's work: the professional projects of nurses and occupational therapists in SwedenNURSING INQUIRY, Issue 4 2005Lars Evertsson In this article we explore how Swedish welfare politics within health-care and rehabilitation has opened up a space for nurses' and occupational therapists' professional projects. Using historical data, an analysis of the policy-making process behind welfare programs central to the professionalization of nursing and occupational therapy is presented. The time period covered is, in the case of nurses, the larger part of the twentieth century, while the modern history of occupational therapists first began in the 1940s. Special emphasis is placed on the corporative nature of the Swedish welfare state and the professional strategies utilized by nurses and occupational therapists in their struggle for jurisdiction. In the article, politicization is identified as a core strategy by which female-dominated welfare state occupations in Sweden have tried to gain influence over the welfare policy-making process and their occupations' jurisdiction. [source] Elevated carbon dioxide increases nitrate uptake and nitrate reductase activity when tobacco is growing on nitrate, but increases ammonium uptake and inhibits nitrate reductase activity when tobacco is growing on ammonium nitratePLANT CELL & ENVIRONMENT, Issue 11 2001P. Matt Abstract The influence of elevated [CO2] on the uptake and assimilation of nitrate and ammonium was investigated by growing tobacco plants in hydroponic culture with 2 mm nitrate or 1 mm ammonium nitrate and ambient or 800 p.p.m. [CO2]. Leaves and roots were harvested at several times during the diurnal cycle to investigate the levels of the transcripts for a high-affinity nitrate transporter (NRT2), nitrate reductase (NIA), cytosolic and plastidic glutamine synthetase (GLN1, GLN2), the activity of NIA and glutamine synthetase, the rate of 15N-nitrate and 15N-ammonium uptake, and the levels of nitrate, ammonium, amino acids, 2-oxoglutarate and carbohydrates. (i) In source leaves of plants growing on 2 mm nitrate in ambient [CO2], NIA transcript is high at the end of the night and NIA activity increases three-fold after illumination. The rate of nitrate reduction during the first part of the light period is two-fold higher than the rate of nitrate uptake and exceeds the rate of ammonium metabolism in the glutamate: oxoglutarate aminotransferase (GOGAT) pathway, resulting in a rapid decrease of nitrate and the accumulation of ammonium, glutamine and the photorespiratory intermediates glycine and serine. This imbalance is reversed later in the diurnal cycle. The level of the NIA transcript falls dramatically after illumination, and NIA activity and the rate of nitrate reduction decline during the second part of the light period and are low at night. NRT2 transcript increases during the day and remains high for the first part of the night and nitrate uptake remains high in the second part of the light period and decreases by only 30% at night. The nitrate absorbed at night is used to replenish the leaf nitrate pool. GLN2 transcript and glutamine synthetase activity rise to a maximum at the end of the day and decline only gradually after darkening, and ammonium and amino acids decrease during the night. (ii) In plants growing on ammonium nitrate, about 30% of the nitrogen is derived from ammonium. More ammonium accumulates in leaves during the day, and glutamine synthetase activity and glutamine levels remain high through the night. There is a corresponding 30% inhibition of nitrate uptake, a decrease of the absolute nitrate level, and a 15,30% decrease of NIA activity in the leaves and roots. The diurnal changes of leaf nitrate and the absolute level and diurnal changes of the NIA transcript are, however, similar to those in nitrate-grown plants. (iii) Plants growing on nitrate adjust to elevated [CO2] by a coordinate change in the diurnal regulation of NRT2 and NIA, which allows maximum rates of nitrate uptake and maximum NIA activity to be maintained for a larger part of the 24 h diurnal cycle. In contrast, tobacco growing on ammonium nitrate adjusts by selectively increasing the rate of ammonium uptake, and decreasing the expression of NRT2 and NIA and the rate of nitrate assimilation. In both conditions, the overall rate of inorganic nitrogen utilization is increased in elevated [CO2] due to higher rates of uptake and assimilation at the end of the day and during the night, and amino acids are maintained at levels that are comparable to or even higher than in ambient [CO2]. (iv) Comparison of the diurnal changes of transcripts, enzyme activities and metabolite pools across the four growth conditions reveals that these complex diurnal changes are due to transcriptional and post-transcriptional mechanisms, which act several steps and are triggered by various signals depending on the condition and organ. The results indicate that nitrate and ammonium uptake and root NIA activity may be regulated by the sugar supply, that ammonium uptake and assimilation inhibit nitrate uptake and root NIA activity, that the balance between the influx and utilization of nitrate plays a key role in the diurnal changes of the NIA transcript in leaves, that changes of glutamine do not play a key role in transcriptional regulation of NIA in leaves but instead inhibit NIA activity via uncharacterized post-transcriptional or post-translational mechanisms, and that high ammonium acts via uncharacterized post-transcriptional or post-translational mechanisms to stabilize glutamine synthetase activity during the night. [source] Study of interphase in glass fiber,reinforced poly(butylene terephthalate) compositesPOLYMER COMPOSITES, Issue 1 2004A. Bergeret It is well known that application of a coupling agent to a glass fiber surface will improve fiber/matrix adhesion in composites. However, on commercial glass fibers the coupling agent forms only a small fraction of the coating, the larger part being a mixture of processing aids whose contribution to composite properties is not well defined. The interfacial region of the composite will therefore be affected by the coating composition but also by the chemical reactions involved in the vicinity of the fiber and inside the surrounding matrix. The main feature of this study consists in dividing the interface region into two separate regions: the fiber/sizing interphase and the sizing/matrix interphase. A wide range of techniques was used, including mechanical and thermomechanical tests, infrared spectroscopy, gel permeation chromatography, carboxyl end group titrations, extraction rate measurements, and viscosity analysis. Experiments were performed on poly(butylene terephthalate) composites and results indicate that the adhesion improvement is due to the presence of a short chain coupling agent and of a polyfunctional additive, which may react both with the coupling agent and the matrix. According to the nature of this additive, it may be possible to soften the interphase and then to increase the composite impact strength. [source] Winter ecology of the Arunachal macaque Macaca munzala in Pangchen Valley, western Arunachal Pradesh, northeastern IndiaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2009Uttara Mendiratta Abstract The newly described Arunachal macaque Macaca munzala occurs largely in sub-tropical to temperate environments at elevations of c. 1,800,3,000,m in Arunachal Pradesh, northeastern India. We studied its over-wintering strategy by comparing the diet, ranging, and behavior of a troop of 24 individuals during winter and spring (December 2005 to May 2006) through instantaneous scan sampling (3,002 records, 448 scans, 112,hr of observation). We also monitored the phenology of food plants. The macaques spent more time (41,66%) feeding in the winter than in spring (33,51%), whereas time spent moving and resting was greater in spring. The diet composed largely of plants, with animal matter being eaten rarely. The number of plant species in the diet increased from 18 to 25 whereas food types rose from 18 to 36 from winter to spring, respectively. Although only two species formed 75% of the winter diet, seven species comprised this proportion in spring. Availability of fruits and young leaves increased in spring; the troop moved more and utilized a larger part of its range during this time. Seasonal changes in behavior could be explained by the scarcity of food and the costs of thermoregulation in winter. Our study suggests that the Arunachal macaque inhabits a highly seasonal environment and has an over-wintering strategy that includes subsisting on a high-fiber diet by increasing the time spent feeding, and minimizing energy expenditure by reducing the time spent moving. Am. J. Primatol. 71:939,947, 2009. © 2009 Wiley-Liss, Inc. [source] East Asian monsoon instability at the stage 5a/4 transitionBOREAS, Issue 2 2002SHANGFA XIONG The physics involved in the abrupt climate changes of the late Quaternary have eluded paleoclimatologists for many years. More paleoclimatic records characteristic of different elements of the global climate system are needed for better understanding of the cause-feedback relationships in the system. The East Asian monsoon is an important part of the global climate system and the mechanical links between the East Asian monsoon and other climatic elements around the world may hold a key to our knowledge of abrupt climate changes in East Asia and probably over a larger part of the globe. Previous studies have detected millennial-scale winter monsoon oscillations during the last glaciation and probably also during the last interglaciation in loess sequences across China. However, less attention has been paid to the abrupt summer monsoon changes and the stage 5a/4 transition, an important period for the evolution of the East Asian monsoon when the global climate shifted towards the last glaciation. Here we report on two loess sections from eastern China which were dated using a thermoluminescence (TL) technique. The pedogenic and other sediment parameters suggest that the summer monsoon experienced a two-step abrupt retreat at the stage 5a/4 transition. The variations in the proxies for the winter monsoon are synchronized with the summer monsoon proxies during this brief interval, implying a direct and immediate link between high latitude and low latitude mechanisms. These changes may be correlated with similar climatic oscillations observed in the North Atlantic, Europe and Antarctica, raising the possibility that the forcing factors that induced these changes are global in extent. [source] Movin' On Up: Interpreting The Earnings,Experience ProfileBULLETIN OF ECONOMIC RESEARCH, Issue 4 2000Alan Manning Human capital theory provides the generally accepted interpretation of the relationship between earnings and labour market experience, namely that general human capital tends to increase with experience. However, there are other plausible interpretations. Search models, for example, generally predict that more time in the labour market increases the chance of finding a better match and hence tends to be associated with higher earnings. This paper shows how a simple search model can be used to predict the amount of earnings growth that can be assigned to search with the residual being assigned to the human capital model. A substantial if not the larger part of the rise in earnings over the life-cycle in Britain can be explained by a simple search model, and virtually all the earnings gap between men and women can be explained in this way. Overall, the evidence suggests that we do need to reinterpret the returns to experience in earnings functions. [source] | |||||||||||||||||||