Instant Efficient Pollution Abatement under Non-Linear Taxation and Asymmetric Information: The Differential Tax Revisited

This paper analyzes incentives for polluting firms to exchange abatement cost information under the non-linear pollution tax scheme (‘differential tax’) introduced by Kim and Chang [J. Regul. Econom. 5, 1993, 193-197]. It shows that polluting firms have - under mild conditions - an incentive to join a coalition whose members mutually truthfully exchange information as well as commit themselves with respect to their abatement decisions. As a result, the differential tax triggers instantly - i.e. no abatement adaptation is needed – efficient abatement levels without the regulator knowing marginal abatement costs. Consequently, this paper shows that differential taxation results in lower social costs than traditional non-linear taxation which triggers efficient emissions only after a period of non-efficient abatement.Externalities, Pollution taxes, Coalition formation, Non-linear taxation, Asymmetric information, Co-operative game theory

A comment on "An arbitrage-free approach to quasi-option value" by Coggins and Ramezani

In their article ?An Arbitrage-Free Approach to Quasi-Option Value? [J. Environm. Econom. Management 35, 103-125, 1998], Coggins and Ramezani interpreted the concept of quasi-option value introduced by Arrow and Fisher [Quart. J. Econom. 88, 1974, 312-319] as being identical to Dixit and Pindyck?s real option value. This means their approach differs from the approach by Fisher and Hanemann [J. Environm. Econom. Management 14, 183-190, 1987] who formalized the concept of quasi-option value a decade before. By indirectly characterizing Dixit and Pindyck?s real option value Coggins and Ramezani confirmed classic results in the field of real options theory. --

The Dixit-Pindyck and the Arrow-Fisher-Hanemann-Henry option values are not equivalent

Fisher [2000, this journal] offers a unifying framework for two concepts of (quasi-) option value suggested by Arrow, Fisher, Hanemann, and Henry (AFHH) on the one hand, and by Dixit and Pindyck (DP) on the other, and claims these two concepts to be equivalent. We show that this claim is not correct and point out the flaws in Fisher's proof. We further suggest a decomposition of the DP option value into two components, one of which corresponds exactly to the AFHH option value which captures the value of obtaining new information, and a second one which captures the postponement value irrespective of uncertainty. --option value,quasi option value,decision under uncertainty,irreversible investment

HERBIVORY AND DETRITIVORY BY THE LAND SNAIL CEPAEA NEMORALIS IN A TEMPERATE OLD FIELD

The European banded wood snail (Cepaea nemoralis) has become widespread throughout the northeast United States and Canada, thriving in woodlands, roadsides, disturbed habitats, grasslands, and old fields. I used exclosure experiments to investigate the effect of snail herbivory on the biomass of Canada thistle (Cirsium arvense), a highly palatable forb species. I measured grass litter within exclosures to determine the effects o f detritivory on litter mass and used fecal analysis to determine the ratio of dead to live plant material in the diet. Snail exclosures had no effect on the total biomass of C. arvense or mass of grass litter. Live plants comprised approximately 10% of the overall snail diet with the remainder consisting of plant litter and soil. There was no clear seasonal trend in consumption of green material. However, snail herbivory increased with time from the last precipitation event, suggesting that snails consume live material to obtain water

Factors influencing the recruitment, growth and reproduction of a temperate reef fish, Forsterygion lapillum

In order to gain a comprehensive understanding of population dynamics, it is vital to identify the key factors that contribute to variation in both survival and reproductive success throughout the life history of an organism. The population dynamics of reef fishes may be influenced by events occurring across multiple life stages, throughout the entire life cycle. For instance, the input of new individuals into a population (recruitment) is heavily shaped by mortality in the larval and juvenile stages, which is influenced by conspecific interactions and habitat characteristics. For individuals that survive, variation in somatic growth histories during development may influence mating success among fish that successfully recruit into the adult population, and particular developmental histories may receive a disproportionate amount of a population’s reproductive output. However, female preferences for particular phenotypes may also be modified by events occurring in adult life, such as parasite infection. Finally, absolute reproductive success (i.e., the number of offspring that survive to reproductive age) may be dependent upon early larval mortality of offspring, and variation in larval mortality among spawning sites could have consequences for metapopulation dynamics. In this thesis, I investigated how recruitment, growth and reproductive success varied among individuals of a small temperate reef fish, Forsterygion lapillum, the common triplefin, based upon their developmental histories, morphological traits, and habitat characteristics (including conspecific densities, regional locations, etc.). Specifically, I examined: - how the spatial distribution and survival of juveniles is influenced by age-class interactions (Chapter 2) - verified methods to measure somatic growth rates during development using scale structures (Chapter 3) - explored how previous growth rates influence reproductive success (Chapter 4) - evaluated how reproductive success is modified by the presence of ectoparasites (Chapter 5) - and finally, assessed how natal origin modifies larval survival probabilities among offspring (Chapter 6). The larvae of many reef fishes settle into habitats that are already occupied by adults, and interactions between age classes (intercohort interactions) may affect spatial variation in recruitment strength across settlement sites. In Chapter 2, I evaluated spatial covariation in juvenile and adult densities of F. lapillum (within the preferred settlement habitats of juveniles) to investigate correlations between adult and juvenile densities potentially caused by age-class interactions. The relationship between juvenile and adult densities followed a dome-shaped curve, with a negative correlation between juveniles and adults at higher adult densities. The shape of this curve was temporally variable, but was otherwise unaffected by particular features of the site (algal species identity). Using a laboratory-based experiment that used a “multiple predator effects” (MPE) design, I tested the hypothesis that increased settler mortality, caused by either (i) intercohort competition leading to enhanced predation risk or (ii) cannibalism by adults on juveniles, contributed to the observed negative relationship between juvenile and adult densities. Results suggested overall mortality attributable to cannibalism was low; however, smaller settlers appeared to be more vulnerable to cannibalism. There was no evidence that combined or interacting effects between predators (F. lapillum adults and Forsterygion varium [the variable triplefin]) increased predation risk in settlers of F. lapillum. Overall, these results highlight the potentially complex effects adult residents may have on shaping patterns of recruitment and the distributions of new juveniles. Somatic growth rates through ontogeny are one of the most important metrics for understanding fish populations and in Chapter 3, I evaluate the use of spacing between growth increments on fish scales (called circuli) as a measurement technique for assessing historical growth in F. lapillum. First, I established the relationship between scale growth and body size, and determined how variable this relationship was among populations. The body-scale size relationship was strongly positive and was unaffected by gender; however, there did appear to be significant differences between certain populations. Second, I monitored somatic and fish scale growth in the laboratory to measure the relationship between somatic growth and spacing between growth increments (intercirculus spacing). New scale growth and circuli deposition were both positively correlated with somatic growth. Average intercirculus spacing was also positively correlated with somatic growth rate, but this appeared to differ between age/size classes, with the older and larger individuals showing a weaker relationship. Results suggest that intercirculus spacing can be used to determine previous growth histories, but may be limited to particular size/age ranges (e.g., juveniles). In Chapter 4, I employ the techniques developed in Chapter 3 to examine how early growth rates (derived from fish scales) and male morphological traits explain variation in reproductive output between individual males in F. lapillum. I measured the reproductive success of breeding males in relation to their size and growth rates over the breeding season at two different spawning locations. Clutch size (number of eggs per nest) was highly variable among individuals over the study period; however, I detected a significant, albeit subtle, negative correlation between clutch size and growth rates after settlement. Although growth explained relatively small amounts of total variation, it was the only male trait I measured that significantly correlated with clutch size. The negative effects of faster growth on clutch size were greatest during the period of growth after settlement suggesting that growth at this early stage may be important for later reproductive success (early post-settlement). In Chapter 5, I examined how infection with an ectoparasite modified reproductive success among individual males using a field survey. Females often preferentially mate with unparasitised males, and therefore parasitised males experience lowered reproductive success. In this study, individuals of greater total length were more likely to be infected with an ectoparasite, but were also more likely to have an egg nest. Parasite infection had no effect on reproductive success (either the presence of a nest, or the average surface area of eggs if a nest was present). Positive covariation in total length, reproductive success, and parasite infection potentially suggest that the influence of parasitic infection on reproductive success may depend upon the strength of selection for larger male body size. In addition, this study provides the first quantitative measurement of ectoparasite infection for both the focal parasite species (Caligus buechlerae) and the host (F. lapillum). Finally, in Chapter 6, I explore how larval survival is mediated by spawning location. In marine reef fish, spatially isolated adult populations may be connected (i.e., have gene flow) via larval dispersal; however, differential larval survival between source populations may mediate both the degree of population connectivity as well as the reproductive success of individuals within those source populations. To evaluate variation in larval quality among different spawning locations, I conducted a laboratory assay to measure the potential effects of source population on larval time to starvation, as starvation is often proposed as a major source of mortality for larval fish. Average survival time was 3.75 days, but survival analysis indicated that starvation resistance did not differ between the two natal sources. For individual nests, mean larval size was negatively correlated with their mean survival time, although this was only apparent in larvae collected from one population (the south coast). My findings indicate that variation in larval traits between source populations does exist, but that on average, source populations had equal resistance to starvation. Given the differences between source populations in (i) the relationship between larval mortality and larval size (i.e., the absence of size effects in one source population) and (ii) overall variation in larval size (larger larvae on the south coast), the relative contribution of larvae from each source population may vary under certain conditions (e.g., low levels of food availability). In conclusion, the field surveys and laboratory experiments conducted in this thesis demonstrate the potential for a variety of factors across multiple life history stages to influence recruitment, growth and reproduction. These findings suggest that factors across multiple life stages (e.g., conspecific density, previous growth histories, or spawning site) have the ability to influence individual success, and in turn populations. By carefully considering and integrating these factors into our studies of population dynamics, we may be able to gain a more comprehensive understanding of the spatio-temporal fluctuations in populations for marine reef fish

CFD SIMULATIONS OF THE IMPACT OF A LINE VEGETATION ELEMENT ALONG A MOTORWAY ON LOCAL AIR QUALITY

In the paper a CFD-based micro scale air quality model called ENVI-met will be presented. ENVI-met distinguishes itself from other CFD-models due the implementation of a detailed vegetation model which describes the interaction of local vegetation, not only on the wind field, but also on the thermodynamic processes and the diffusion and deposition of gases and particulate matter. This makes the model particularly suitable for a recent research programme initiated by the Air Quality Innovation Project (IPL), founded by the Dutch Ministry for Transport, Public Works and Water Management (Rijkswaterstaat) and the Ministry of Housing, Spatial Planning & the Environment (Ministry of VROM). One of the seven branches of the IPL-project is to investigate both by measurements and modelling the effect of line vegetation along a motorway on local air quality. Recently the model results have been compared to a first measurement campaign

Reduction in BACE1 decreases body weight, protects against diet-induced obesity and enhances insulin sensitivity in mice

Insulin resistance and impaired glucose homoeostasis are important indicators of Type 2 diabetes and are early risk factors of AD (Alzheimer's disease). An essential feature of AD pathology is the presence of BACE1 (β-site amyloid precursor protein-cleaving enzyme 1), which regulates production of toxic amyloid peptides. However, whether BACE1 also plays a role in glucose homoeostasis is presently unknown. We have used transgenic mice to analyse the effects of loss of BACE1 on body weight, and lipid and glucose homoeostasis. BACE1−/− mice are lean, with decreased adiposity, higher energy expenditure, and improved glucose disposal and peripheral insulin sensitivity than wild-type littermates. BACE1−/− mice are also protected from diet-induced obesity. BACE1-deficient skeletal muscle and liver exhibit improved insulin sensitivity. In a skeletal muscle cell line, BACE1 inhibition increased glucose uptake and enhanced insulin sensitivity. The loss of BACE1 is associated with increased levels of UCP1 (uncoupling protein 1) in BAT (brown adipose tissue) and UCP2 and UCP3 mRNA in skeletal muscle, indicative of increased uncoupled respiration and metabolic inefficiency. Thus BACE1 levels may play a critical role in glucose and lipid homoeostasis in conditions of chronic nutrient excess. Therefore strategies that ameliorate BACE1 activity may be important novel approaches for the treatment of diabetes

Differential effects of natural palm oil, chemically- and enzymatically-modified palm oil on weight gain, blood lipid metabolites and fat deposition in a pediatric pig model

<p>Abstract</p> <p>Background</p> <p>Increasing prevalence of obesity and overweight in the Western world, continue to be a major health threat and is responsible for increased health care costs. Dietary intervention studies show a strong positive association between saturated fat intake and the development of obesity and cardiovascular disease. This study investigated the effect of positional distribution of palmitic acid (Sn-1, 2 & 3) of palm oil on cardiovascular health and development of obesity, using weaner pigs as a model for young children.</p> <p>Methods</p> <p>Male and female weaner piglets were randomly allocated to 4 dietary treatment groups: 1) pork lard (LRD); 2) natural palm olein (NPO); 3) chemically inter-esterified PO (CPO) and 4) enzymatically inter-esterified PO (EnPO) as the fat source. Diets were formulated with 11% lard or with palm olein in order to provide 31% of digestible energy from fat in the diet and were balanced for cholesterol, protein and energy across treatments.</p> <p>Results</p> <p>From 8 weeks onwards, pigs on EnPO diet gained (P < 0.05) more weight than all other groups. Feed conversion efficiency (feed to gain) over the 12 week experimental period did not vary between treatment groups. Plasma LDL-C content and LDL-C/HDL-C ratio in pigs fed natural PO tended to be lower compared to all other diets. The natural PO lowered (P < 0.02) the plasma triglyceride (TG) content relative to the lard or EnPO diets, but was not different from the CPO diet. The natural PO diet was associated with lower (P < 0.05) saturated fat levels in subcutaneous adipose tissue than the CPO and EnPO diets that had lower saturated fat levels than the lard diet. Female pigs had lower lean and higher fat and fat:lean ratio in the body compared with male pigs. No difference in weight gain or blood lipid parameters was observed between sexes.</p> <p>Conclusions</p> <p>The observations on plasma TG, muscle and adipose tissue saturated fatty acid contents and back fat (subcutaneous) thickness suggest that natural palm oil may reduce deposition of body fat. In addition, dietary supplementation with natural palm oil containing palmitic acid at different positions in meat producing animals may lead to the production of meat and meat products with lower saturated fats. An increase in fat content and a decrease in lean content in female pigs resulted in an increased body fat:lean ratio but gender had no effect on blood lipid parameters or insulin concentrations.</p