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Costs
Kinds of Costs Terms modified by Costs Selected AbstractsTURNING ISOLATION TO ADVANTAGE IN REGIONAL COST,BENEFIT ANALYSISECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 1 2007LEO DOBES Projects in small regional communities are rarely subjected to cost,benefit analysis, partly because of the perceived difficulty and cost of doing so. However, the very isolation of such communities means that well-established analytical techniques used for transport projects can be used to estimate the costs and benefits of government provision of goods and services. [source] Counting the COST: a European collaboration on the efficiency of psychotherapeutic treatment of patients with eating disordersEUROPEAN EATING DISORDERS REVIEW, Issue 3 2005Hans Kordy Abstract In 1993, a European collaboration on the efficiency of psychotherapeutic treatment of patients with Eating Disorders was initiated. The European Union supported it under the name COST Action B6 from 1994,2001. This unique opportunity to co-ordinate research and to exchange clinical experience eventually attracted more than 200 researchers and clinicians from 19 European countries. This is the first paper of a series of five through which we report on the general background, the organizational structure, the objectives, the design, the main findings, and specific methodological developments of COST Action B6. Copyright © 2005 John Wiley & Sons, Ltd and Eating Disorders Association. [source] THE COST OF MELANIZATION: BUTTERFLY WING COLORATION UNDERENVIRONMENTAL STRESSEVOLUTION, Issue 2 2004W. Talloen Abstract Evolutionary studies typically focus on adaptations to particular environmental conditions, thereby often ignoring the role of possible constraints. Here we focus on the case of variation in dorsal wing melanization in a satyrine butterfly Pararge aegeria. Because melanin is a complex polymer, its synthesis may be constrained if ambient conditions limit the resource budget. This hypothesis was tested by comparing melanization among butterflies that fed as larvae on host grasses experiencing different drought-stress treatments. Treatment differences were validated both at the level of the host plant (nitrogen, carbonate, and water content) and of the butterfly (life-history traits: survival, development time, and size at maturity). Melanization rate was measured as average gray value of the basal dorsal wing area. This area, close to the thorax, is known to be functionally significant for basking in order to thermoregulate. Individuals reared on drought-stressed host plants developed paler wings, and development of darker individuals was slower and less stable as estimated by their level of fluctuating asymmetry. These results provide evidence that melanin is indeed costly to synthesize, and that differences in environmental quality can induce phenotypic variation in wing melanization. Therefore, studies dealing with spatial and/or temporal patterns of variation in wing melanization should not focus on adaptive explanations alone, but rather on a cost-benefit balance under particular sets of environmental conditions. [source] REPRODUCTIVE BURDEN, LOCOMOTOR PERFORMANCE, AND THE COST OF REPRODUCTION IN FREE RANGING LIZARDSEVOLUTION, Issue 4 2000Donald B. Miles Abstract. A reduction in the locomotor capacity of gravid females is considered to be a cost of reproduction if it leads to an increased risk of mortality. In this study, we measured the change in endurance between gravid and postgravid female side-blotched lizards (Uta stansburiana) as a test of the cost of reproduction. We also altered reproductive investment in some females by direct ovarian manipulation (yolkectomy), which decreased reproductive burden by 30%. Regardless of experimental treatment, all females had lower endurance when gravid. Endurance was 28% lower in gravid females from the yolkectomy treatment and 31% lower in the unmanipulated females relative to postoviposition females. The experimental reduction in clutch mass resulted in a 21% increase in endurance of gravid yolkectomy females relative to control females. Postovipositional endurance was significantly higher in the yolkectomized females than unmanipulated females, which suggests that the cost of reproduction carries over to postoviposition performance. Unmanipulated females exhibited a significant negative association between endurance and size-specific burden. Endurance was not correlated with clutch size or size-specific burden in the yolkectomy females. Survivorship to the second clutch was higher in the yolkectomy females. The results from a logistic regression showed the probability of survival to the second clutch was significantly and positively associated with endurance after controlling for the effects of treatment. Our analyses demonstrated that the decrement in performance associated with current reproductive investment represents a cost of reproduction expressed as diminished locomotor performance and lowered survivorship to the next clutch. [source] ADAPTATION AND THE COST OF COMPLEXITYEVOLUTION, Issue 1 2000H. Allen Orr Abstract., Adaptation is characterized by the movement of a population toward a many-character optimum, movement that results in an increase in fitness. Here I calculate the rate at which fitness increases during adaptation and describe the curve giving fitness versus time as a population approaches an optimum in Fisher's model of adaptation. The results identify several factors affecting the speed of adaptation. One of the most important is organismal complexity,complex organisms adapt more slowly than simple ones when using mutations of the same phenotypic size. Thus, as Fisher foresaw, organisms pay a kind of cost of complexity. However, the magnitude of this cost is considerably larger than Fisher's analysis suggested. Indeed the rate of adaptation declines at least as fast as n -1, where n is the number of independent characters or dimensions comprising an organism. The present results also suggest that one can define an effective number of dimensions characterizing an adapting species. [source] Performance of multilevel-turbo codes with blind/non-blind equalization over WSSUS multipath channelsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 3 2006Osman N. Ucan Abstract In this paper, in order to improve error performance, we introduce a new type of turbo codes, called ,multilevel-turbo codes (ML-TC)' and we evaluate their performance over wide-sense stationary uncorrelated scattering (WSSUS) multipath channels. The basic idea of ML-TC scheme is to partition a signal set into several levels and to encode each level separately by a proper component of the turbo encoder. In the considered structure, the parallel input data sequences are encoded by our multilevel scheme and mapped to any modulation type such as MPSK, MQAM, etc. Since WSSUS channels are very severe fading environments, it is needed to pass the received noisy signals through non-blind or blind equalizers before turbo decoders. In ML-TC schemes, noisy WSSUS corrupted signal sequence is first processed in equalizer block, then fed into the first level of turbo decoder and the first sequence is estimated from this first Turbo decoder. Subsequently, the other following input sequences of the frame are computed by using the estimated input bit streams of previous levels. Here, as a ML-TC example, 4PSK 2 level-turbo codes (2L-TC) is chosen and its error performance is evaluated in WSSUS channel modelled by COST 207 (Cooperation in the field of Science & Technology, Project #207). It is shown that 2L-TC signals with equalizer blocks exhibit considerable performance gains even at lower SNR values compared to 8PSK-turbo trellis coded modulation (TTCM). The simulation results of the proposed scheme have up to 5.5 dB coding gain compared to 8PSK-TTCM for all cases. It is interesting that after a constant SNR value, 2L-TC with blind equalizer has better error performance than non-blind filtered schemes. We conclude that our proposed scheme has promising results compared to classical schemes for all SNR values in WSSUS channels. Copyright © 2005 John Wiley & Sons, Ltd. [source] EVIDENCE THAT GREATER DISCLOSURE LOWERS THE COST OF EQUITY CAPITALJOURNAL OF APPLIED CORPORATE FINANCE, Issue 4 2000Christine A. Botosan The effect of corporate disclosure on the cost of equity capital is a matter of considerable interest and importance to both corporations and the investment community. However, the relationship between disclosure level and cost of capital is not well established and has proved difficult for researchers to quantify. As described in this article, the author's 1997 study (published in The Accounting Review) was the first to measure and detect a direct relationship between disclosure and cost of capital. After examining the annual reports of 122 manufacturing companies, the author concluded that companies providing more extensive disclosure had a lower (forward-looking) cost of equity capital (measured using Value Line forecasts with an EBO valuation formula that derives from the dividend discount model). For companies with extensive analyst coverage, differences in disclosure do not appear to affect cost of capital. But for companies with small analyst followings, differences in disclosure do appear to matter. Among this group of companies, the firms judged to have the highest level of disclosure had a cost of equity capital that was nine-percentage points lower than otherwise similar firms with a minimal level of disclosure. Closer analysis of some of the specific disclosure practices also suggests that, for small firms with limited analyst coverage, there are benefits to providing more forward-looking information, such as forecasts of sales, profits, and capital expenditures, and enhanced disclosure of key non-financial statistics, such as order backlogs, market share, and growth in units sold. In closing, the article also discusses an interesting new study (by Lang and Lundholm) that suggests there is an important distinction between effective corporate disclosure and "hyping the stock." The findings of this study show that while higher levels of disclosures are associated with higher stock prices, sudden increases in the frequency of disclosure are viewed with skepticism. [source] EVALUATION OF GLOBAL YIELD, COMPOSITION, ANTIOXIDANT ACTIVITY AND COST OF MANUFACTURING OF EXTRACTS FROM LEMON VERBENA (ALOYSIA TRIPHYLLA[L'HÉRIT.] BRITTON) AND MANGO (MANGIFERA INDICA L.) LEAVESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2007CAMILA G. PEREIRA ABSTRACT In this work, the global yields, composition and antioxidant activity (AA) of extracts from lemon verbena (Aloysia triphylla) and mango (Mangifera indica) leaves obtained by different separation processes were determined. Lemon verbena extracts were obtained by supercritical fluid extraction (SFE), while mango leaf extracts were obtained by SFE, low-pressure solvent extraction (LPSE) and hydrodistillation. The extract's constituents were analyzed by thin-layer chromatography, gas chromatography/mass spectrometry and gas chromatography/flame ionization detector. The AA of the extracts was evaluated by the coupled reaction of , -carotene/linolenic acid. The cost of manufacturing (COM) was estimated for the SFE extracts. Higher global yields were obtained using SFE at 350 bar/45C (1.49%) for lemon verbena and LPSE (3.04%) for mango. The AAs of the extracts were larger than that of the , -carotene for both plants. The minimum values of COM were U.S.$26.96 and 52.45/kg of extract for lemon verbena and mango, respectively. [source] THE COST OF ILLIQUIDITY AND ITS EFFECTS ON HEDGINGMATHEMATICAL FINANCE, Issue 4 2010L. C. G. Rogers Though liquidity is commonly believed to be a major effect in financial markets, there appears to be no consensus definition of what it is or how it is to be measured. In this paper, we understand liquidity as a nonlinear transaction cost incurred as a function of rate of change of portfolio. Using this definition, we obtain the optimal hedging policy for the hedging of a call option in a Black-Scholes model. This is a more challenging question than the more common studies of optimal strategy for liquidating an initial position, because our goal requires us to match a random final value. The solution we obtain reduces in the case of quadratic loss to the solution of three partial differential equations of Black-Scholes type, one of them nonlinear. [source] The use of Geographic Information Systems in climatology and meteorology: COST 719METEOROLOGICAL APPLICATIONS, Issue 1 2005Izabela Dyras The COST Action 719 started in 2001 and presently 20 European countries are participating. The main objectives of the Action are to establish interfaces between GIS and meteorological data, assess the availability, contents and accessibility of meteorological and climatological data sets and encourage and foster European co-operation. The tasks are carried out within three working groups concentrated on issues such as data access and availability, methods of spatial interpolation and developing recommendations for standardised GIS applications. The applications that have been adopted mainly focus on three parameters, i.e. precipitation, temperature and energy balance for which three demonstration projects have been formulated. It is expected that the Action will result in recommendations for better and more cost-effective production of state-of-the-art meteorological and climatological information. Also an improvement of the co-operation between European countries in the application of GIS in the field of meteorology, climatology and environmental sciences should be achieved together with better-trained personnel within the operational and scientific divisions of national meteorological services. Additionally, the development of a visualisation system for climate data sets for internet applications is under preparation. This paper provides information concerning the work in progress on the demonstration projects made within COST 719. Copyright © 2005 Royal Meteorological Society. [source] SALES MAXIMIZATION AND PROFIT MAXIMIZATION: A NOTE ON THE DECISION OF A SALES MAXIMIZER TO THE INCREASE OF PER UNIT COSTPACIFIC ECONOMIC REVIEW, Issue 5 2007Ke Li A common mistake in currently used textbooks is pointed out, and a new proposition is proposed for replacing a false statement there. [source] EVALUATING THE ECONOMIC COST OF ENVIRONMENTAL MEASURES IN PLANTATION HARVESTING THROUGH THE USE OF MATHEMATICAL MODELSPRODUCTION AND OPERATIONS MANAGEMENT, Issue 3 2003FELIPE CARO An important issue being discussed for Chilean pine plantation policies is the application of environmental protection measures when managing its timber areas. Typical measures, already in place in more developed countries, include imposing riparian strips and protecting fragile soils from the use of heavy machinery. While environmental protection measures have been considered vital for decades, so far there has been almost no attempt to quantify both the benefits and costs of these measures. This paper attempts to measure the costs associated with the main measures which can help both the forestry firms and the government evaluate the cost impact of the new environmental protection regulations being studied. The analysis for different environmental scenarios is carried out by modifying a mixed integer LP, currently used for tactical planning by one forestry firm. [source] STRUCTURE REGULATION, PRICE STRUCTURE, CROSS-SUBSIDIZATION AND MARGINAL COST OF PUBLIC FUNDS,THE MANCHESTER SCHOOL, Issue 6 2009MING CHUNG CHANG In this paper we study the social desirability of the structure regulation which transforms a single multi-product monopoly into an oligopoly where the industry produces differentiated complementary goods. In particular, we pay special attention to the cross-subsidization which will be eliminated by the structure regulation. It is established that if horizontal externalities between the goods are not too strong, then the monopoly has a socially optimal price structure. In contrast, the oligopoly always distorts the price structure. We also demonstrate that the monopoly will cross-subsidize a product if and only if this product has a relatively low absolute advantage. [source] The COST 723 ActionTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue S2 2007W. A. Lahoz Abstract An overview is provided of the COST 723 Action, ,Data Exploitation and Modelling of the Upper Troposphere and Lower Stratosphere'. The three working groups are introduced and a summary of Action activities within them is provided. The achievements of the Action are: three international workshops; the LAUTLOS humidity measurement campaign; dedicated meetings to discuss the quality of upper troposphere/lower stratosphere ozone and humidity measurements; two journal special issues; more than 90 papers in the peer-reviewed literature; one international summer school; and a successor COST Action which builds on COST 723. The recommendations made are: for COST to continue to support the short-term scientific missions instrument, as they are perceived to be value for money; to encourage the use of COST money to increase links between COST Actions and other scientific communities; and for the COST secretariat to recommend that Actions consider a summer school instead of a final workshop or meeting. Copyright © 2007 Royal Meteorological Society [source] COST, DEMOGRAPHICS AND INJURY PROFILE OF ADULT PEDESTRIAN TRAUMA IN INNER SYDNEYANZ JOURNAL OF SURGERY, Issue 1-2 2006Timothy J. Small Background: Pedestrian accidents are associated with substantial morbidity, mortality and cost; however, there has been very little published work on this topic in Australasia over recent years. The objective of this study was to examine the demographics, injury profile, outcomes and cost of pedestrian versus motor vehicle accidents in a central city hospital in Sydney. Methods: Consecutive pedestrians injured by motor vehicles and admitted as inpatients during the years 2002,2004 were identified from our prospective trauma registry. A retrospective review included patient profiles (age, sex, time of injury and blood alcohol), injury pattern, cost, morbidity and mortality. Results: A total of 180 patients (64% men and 36% women) with a mean age of 46 and mean injury severity score of 14.1 were identified. Two peak injury periods were observed: one between 17.00 and 18.00 hours (P < 0.01) and the other between 20.00 and 22.00 hours (P < 0.01). Significantly more injuries occurred on Friday (P < 0.01) and during autumn months (P < 0.05). Musculoskeletal (34.3%), head (31.8%) and external (20.2%) injuries predominated. Forty-nine per cent of patients tested positive for consuming alcohol, with an average blood alcohol concentration (BAC) of 0.22%. Alcohol consumption was associated with a worse outcome in terms of hospital and intensive care unit stay, morbidity and mortality. The average length of stay was 13.4 days costing $A16320 per admission. Sixteen patients died (mortality rate of 8.9%), with the highest rate in the elderly group (22.7%) (P < 0.001). Conclusions: Pedestrian accidents in inner Sydney are common with injuries predominating in intoxicated adult males. Mortality was higher in the elderly group. Injuries to the head and lower extremities predominate. Hospital stays are lengthy, resulting in a high cost for each admission. [source] Visualizing flood forecasting uncertainty: some current European EPS platforms,COST731 working group 3ATMOSPHERIC SCIENCE LETTERS, Issue 2 2010M. Bruen Abstract Cooperation in Science and Technology (COST) funding allows European scientists to establish international links, communicate their work to colleagues, and promote international research cooperation. COST731 was established to study the propagation of uncertainty from hydrometeorological observations through meteorological and hydrological models to the final flood forecast. Our focus is on how information about uncertainty is presented to the end user and how it is used. COST731 has assembled a number of demonstrations/case studies that illustrate a variety of practical approaches and these are presented here. While there is yet no consensus on how such information is presented, many end users do find it useful. Copyright © 2010 Royal Meteorological Society [source] A WELFARE COST OF THE LOST DECADE IN JAPANAUSTRALIAN ECONOMIC PAPERS, Issue 1 2010TATSUYOSHI MIYAKOSHI This paper measures the welfare cost of the Japanese economy in a ,lost decade' from 1990 to 2002, by using panels of different consumer groups. The paper finds that the costs for consumers in the lower and middle income quintiles and in urban districts are much higher, while there exists a benefit for consumers in rural districts. We suggest that such cost disparities express the business slump related to districts and income quintile group with high costs. Also, there exist consumers feeling this stagnation to be low-cost and the seriousness of stagnation is not recognised unanimously. [source] BENEFITS AND COSTS OF INTENSIVE FOSTER CARE SERVICES: THE CASEY FAMILY PROGRAMS COMPARED TO STATE SERVICESCONTEMPORARY ECONOMIC POLICY, Issue 3 2009RICHARD O. ZERBE The foster care system attempts to prepare children and youth who have suffered child maltreatment for successful adult lives. This study documents the economic advantages of a privately funded foster care program that provided longer term, more intensive, and more expensive services compared to public programs. The study found significant differences in major adult educational, health, and social outcomes between children placed in the private program and those placed in public programs operated by Oregon and Washington. For the outcomes for which we could find financial data, the estimated present value of the enhanced foster care services exceeded their extra costs. Generalizing to the roughly 100,000 adolescents age 12-17 entering foster care each year, if all of them were to receive the private model of services, the savings for a single cohort of these children could be about $6.3 billion in 2007 dollars. (JEL D61, H75) [source] COACHING COSTS AS TULLOCK COSTS: A MODEL OF RISING COACHING SALARIESECONOMIC AFFAIRS, Issue 3 2010Kurt Rotthoff Escalating sports coaching costs have strained budgets at many universities. This paper analyses these expenditures as a form of Tullock Costs (Tullock, 1967). In this framework the money the universities receive is spent on recruiting top talent, so the schools receive little, or no, monetary gain under current scholarship rules. [source] TAXI DEREGULATION AND TRANSACTION COSTSECONOMIC AFFAIRS, Issue 2 2006Christian Seibert Deregulation of taxi markets has the potential to deliver significant benefits. However, it presents the problem of transaction costs and in particular problems linked with imperfect information and co-ordination. This article argues that the use of a centralised intermediary in deregulated taxi markets can overcome these problems so that the benefits of competition are maximised, without the need for government fare regulation. [source] COSTS AND LIMITS OF PHENOTYPIC PLASTICITY IN ISLAND POPULATIONS OF THE COMMON FROG RANA TEMPORARIA UNDER DIVERGENT SELECTION PRESSURESEVOLUTION, Issue 6 2009Martin I. Lind Costs and limits are assumed to be the major constraints on the evolution of phenotypic plasticity. However, despite their expected importance, they have been surprisingly hard to find in natural populations. It has therefore been argued that natural selection might have removed high-cost genotypes in all populations. However, if costs of plasticity are linked to the degree of plasticity expressed, then high costs of plasticity would only be present in populations where increased plasticity is under selection. We tested this hypothesis by investigating costs and limits of adaptive phenotypic plasticity in development time in a common garden study of island populations of the common frog Rana temporaria, which have varying levels of development time and phenotypic plasticity. Costs of plasticity were only found in populations with high-plastic genotypes, whereas the populations with the most canalized genotypes instead had a cost of canalization. Moreover, individuals displaying the most extreme phenotypes also were the most plastic ones, which mean we found no limits of plasticity. This suggests that costs of plasticity increase with increased level of plasticity in the populations, and therefore costs of plasticity might be more commonly found in high-plastic populations. [source] SEX-RATIO CONFLICT BETWEEN QUEENS AND WORKERS IN EUSOCIAL HYMENOPTERA: MECHANISMS, COSTS, AND THE EVOLUTION OF SPLIT COLONY SEX RATIOSEVOLUTION, Issue 12 2005Ken R. Helms Abstract Because workers in the eusocial Hymenoptera are more closely related to sisters than to brothers, theory predicts that natural selection should act on them to bias (change) sex allocation to favor reproductive females over males. However, selection should also act on queens to prevent worker bias. We use a simulation approach to analyze the coevolution of this conflict in colonies with single, once-mated queens. We assume that queens bias the primary (egg) sex ratio and workers bias the secondary (adult) sex ratio, both at some cost to colony productivity. Workers can bias either by eliminating males or by directly increasing female caste determination. Although variation among colonies in kin structure is absent, simulations often result in bimodal (split) colony sex ratios. This occurs because of the evolution of two alternative queen or two alternative worker biasing strategies, one that biases strongly and another that does not bias at all. Alternative strategies evolve because the mechanisms of biasing result in accelerating benefits per unit cost with increasing bias, resulting in greater fitness for strategies that bias more and bias less than the population equilibrium. Strategies biasing more gain from increased biasing efficiency whereas strategies biasing less gain from decreased biasing cost. Our study predicts that whether queens or workers evolve alternative strategies depends upon the mechanisms that workers use to bias the sex ratio, the relative cost of queen and worker biasing, and the rates at which queen and worker strategies evolve. Our study also predicts that population and colony level sex allocation, as well as colony productivity, will differ diagnostically according to whether queens or workers evolve alternative biasing strategies and according to what mechanism workers use to bias sex allocation. [source] COSTS OF AN INDUCED IMMUNE RESPONSE ON SEXUAL DISPLAY AND LONGEVITY IN FIELD CRICKETSEVOLUTION, Issue 10 2004Alain Jacot Abstract Immune system activation may benefit hosts by generating resistance to parasites. However, natural resources are usually limited, causing a trade-off between the investment in immunity and that in other life-history or sexually selected traits. Despite its importance for the evolution of host defense, state-dependent fitness costs of immunity received little attention under natural conditions. In a field experiment we manipulated the nutritional condition of male field crickets Gryllus campestris and subsequently investigated the effect of an induced immune response through inoculation of bacterial lipopolysaccharides. Immune system activation caused a condition-dependent reduction in body condition, which was proportional to the condition-gain during the preceding food-supplementation period. Independent of nutritional condition, the immune insult induced an enduring reduction in daily calling rate, whereas control-injected males fully regained their baseline level of sexual signaling following a temporary decline. Since daily calling rate affects female mate choice under natural conditions, this suggests a decline in male mating success as a cost of induced immunity. Food supplementation enhanced male life span, whereas the immune insult reduced longevity, independent of nutritional status. Thus, immune system activation ultimately curtails male fitness due to a combined decline in sexual display and life span. Our field study thus indicates a key role for fitness costs of induced immunity in the evolution of host defense. In particular, costs expressed in sexually selected traits might warrant the honest advertisement of male health status, thus representing an important mechanism in parasite-mediated sexual selection. [source] FITNESS COSTS OF INSECTICIDE RESISTANCE IN NATURAL BREEDING SITES OF THE MOSQUITO CULEX PIPIENSEVOLUTION, Issue 1 2004Denis Bourguet Abstract Genetic changes conferring adaptation to a new environment may induce a fitness cost in the previous environment. Although this prediction has been verified in laboratory conditions, few studies have tried to document this cost directly in natural populations. Here, we evaluated the pleiotropic effects of insecticide resistance on putative fitness components of the mosquito Culex pipiens. Experiments using different larval densities were performed during the summer in two natural breeding sites. Two loci that possess alleles conferring organophosphate (OP) resistance were considered: ace-1 coding for an acetylcholinesterase (AChE1, the OP target) and Ester, a "super locus" including two closely linked loci coding for esterases A and B. Resistance ace-1 alleles coding for a modified AChE1 were associated with a longer development time and shorter wing length. The pleiotropic effects of two resistance alleles Ester1 and Ester4 coding for the overproduced esterases A1 and A4-B4, respectively, were more variable. Both A1 and A4-B4 reduced wing length, although only A1 was associated with a longer preimaginal stage. The fluctuating asymmetry (FA) of the wing did not respond to the presence or to the interaction of resistance alleles at the two loci at any of the density levels tested. Conversely, the FA of one wing section decreased when larval density increased. This may be the consequence of selection against less developmentally stable individuals. The results are discussed in relation to the local evolution of insecticide resistance genes. [source] PLASTICITY TO LIGHT CUES AND RESOURCES IN ARABIDOPSIS THALIANA: TESTING FOR ADAPTIVE VALUE AND COSTSEVOLUTION, Issue 6 2000Lisa A. Dorn Abstract Plants shaded by neighbors or overhead foliage experience both a reduction in the ratio of red to far red light (R:FR), a specific cue perceived by phytochrome, and reduced photosynthetically active radiation (PAR), an essential resource. We tested the adaptive value of plasticity to crowding and to the cue and resource components of foliage shade in the annual plant Arabidopsis thaliana by exposing 36 inbred families from four natural populations to four experimental treatments: (1) high density, full sun; (2) low density, full sun; (3) low density, neutral shade; and (4) low density, low R:FR-simulated foliage shade. Genotypic selection analysis within each treatment revealed strong environmental differences in selection on plastic life-history traits. We used specific contrasts to measure plasticity to density and foliage shade, to partition responses to foliage shade into phytochrome-mediated responses to the R:FR cue and responses to PAR, and to test whether plasticity was adaptive (i.e., in the same direction as selection in each environment). Contrary to expectation, we found no evidence for adaptive plasticity to density. However, we observed both adaptive and maladaptive responses to foliage shade. In general, phytochrome-mediated plasticity to the R:FR cue of foliage shade was adaptive and counteracted maladaptive growth responses to reduced PAR. These results support the prediction that active developmental responses to environmental cues are more likely to be adaptive than are passive resource-mediated responses. Multiple regression analysis detected a few costs of adaptive plasticity and adaptive homeostasis, but such costs were infrequent and their expression depended on the environment. Thus, costs of plasticity may occasionally constrain the evolution of adaptive responses to foliage shade in Arabidopsis, but this constraint may differ among environments and is far from ubiquitous. [source] HOMEOWNERSHIP IN AN UNCERTAIN WORLD WITH SUBSTANTIAL TRANSACTION COSTS,JOURNAL OF REGIONAL SCIENCE, Issue 5 2007Margaret H. Smith ABSTRACT This paper presents a dynamic model of residential real estate tenure decisions that takes into account the substantial transaction costs and the uncertain time paths of rents and prices. By temporarily postponing decisions, buyers and sellers obtain additional information and may avoid transactions that are costly to reverse. One implication is that the combination of high transaction costs and substantial uncertainty can create a large wedge between a household's reservation prices for buying and selling a home, which can explain why households do not switch back and forth between owning and renting as home prices fluctuate. [source] CONSTRUCTION COSTS AND THE SUPPLY OF HOUSING STRUCTURE,JOURNAL OF REGIONAL SCIENCE, Issue 4 2006Joseph Gyourko ABSTRACT Construction costs account for the bulk of the price of new houses in most markets, but their study has been relatively neglected. We document that there are economically large differences in construction costs across U.S. housing markets. We also estimate a very elastic supply for physical structure; hence, differences in construction activity across markets do not explain the variation in costs. Supply shifters that collectively do account for differences in building costs include the extent of unionization within the construction sector, local wages, local topography in terms of the presence of high hills and mountains, and the local regulatory environment. [source] ARSENIC IN THE SHALLOW GROUND WATERS OF CONTERMINOUS UNITED STATES: ASSESSMENT, HEALTH RISKS, AND COSTS FOR MCL COMPLIANCE,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2006Navin Kumar C. Twarakavi ABSTRACT: A methodology consisting of ordinal logistic regression (OLR) is used to predict the probability of occurrence of arsenic concentrations in different threshold limits in shallow ground waters of the conterminous United States (CONUS) subject to a set of influencing variables. The analysis considered a number of maximum contaminant level (MCL) options as threshold values to estimate the probabilities of occurrence of arsenic in ranges defined by a given MCL of 3, 5, 10, 20, and 50 ,g/l and a detection limit of 1 ,g/l. The fit between the observed and predicted probability of occurrence was around 83 percent for all MCL options. The estimated probabilities were used to estimate the median background concentration of arsenic in the CONUS. The shallow ground water of the western United States is more vulnerable than the eastern United States. Arizona, Utah, Nevada, and California in particular are hotspots for arsenic contamination. The risk assessment showed that counties in southern California, Arizona, Florida, and Washington and a few others scattered throughout the CONUS face a high risk from arsenic exposure through untreated ground water consumption. A simple cost effectiveness analysis was performed to understand the household costs for MCL compliance in using arsenic contaminated ground water. The results showed that the current MCL of 10 ,g/l is a good compromise based on existing treatment technologies. [source] REBUILDING THE EASTERN BALTIC COD STOCK UNDER ENVIRONMENTAL CHANGE (PART II): TAKING INTO ACCOUNT THE COSTS OF A MARINE PROTECTED AREANATURAL RESOURCE MODELING, Issue 1 2009CHRISTINE RÖCKMANN Abstract This study adds a cost analysis of the Eastern Baltic cod fishery to the existing model presented in Röckmann et al. [2007a]. As cost data on this international fishery do not exist, data from Denmark are extrapolated to the whole international fishery. Additionally, unit and total variable costs are simulated, and the sensitivity to a set of different cost,stock and cost,output elasticities is tested. The study supports preliminary conclusions that a temporary marine reserve policy, which focuses on protecting the Eastern Baltic cod spawning stock in the International Council for the Exploration of the Sea (ICES) subdivision 25, is a valuable fisheries management tool to (i) rebuild the overexploited Eastern Baltic cod stock and (ii) increase operating profits. The negative effects of climate change can be postponed for at least 20 years,depending on the assumed rate of future climate change. Including costs in the economic analysis does not change the ranking of management policies as proposed in the previous study where costs were neglected. [source] MEASURING THE COSTS OF REALLOCATING WATER FROM AGRICULTURE: A MULTI-MODEL APPROACHNATURAL RESOURCE MODELING, Issue 2 2002DAVID SUNDING ABSTRACT. Increasing demand for water by environmental interests, coupled with the diminishing prospects for constructing new water diversion projects, is forcing farmers in the western United States to cope with reduced surface water deliveries. The cost of improving instream water quality by reducing agricultural diversions is shown to depend mainly on how the supply reductions are allocated among users and on the extent of water trading. A central contribution of this paper is a methodology for measuring the impacts of water supply policy reforms on irrigated agriculture. The paper nests three empirical models in a general conceptual framework. The models differ in terms of their degree of detail and assumptions about input substitution. By comparing model results, it is possible to place bounds on the consequences of policy changes, and to identify critical factors determining economic impacts. The models are applied to the problem of improving water quality in the San Francisco Bay/Delta estuary. [source] | ||||||||||||||||||||||||||||||||||