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This paper presents results of an online stated choice experiment on preferences of Dutch private car owners for alternative fuel vehicles (AFVs) and their characteristics. Results show that negative preferences for alternative fuel vehicles are large, especially for the electric and fuel cell car, mostly as a result of their limited driving range and considerable refueling times. Preference for AFVs increases considerably with improvements on driving range, refueling time and fuel availability. Negative AFV preferences remain, however, also with substantial improvements in AFV characteristics; the remaining willingness to accept is on average € 10,000-€ 20,000 per AFV. Results from a mixed logit model show that consumer preferences for AFVs and AFV characteristics are heterogeneous to a large extent, in particular for the electric car, additional detour time and fuel time for the electric and fuel cell car. An interaction model reveals that annual mileage is by far the most important factor that determines heterogeneity in preferences for the electric and fuel cell car. When annual mileage increases, the preference for electric and fuel cell cars decreases substantially, whilst the willingness to pay for driving range increases substantially. Other variables such as using the car for holidays abroad and the daily commute also appear to be relevant for car choice. © 2014 Elsevier Ltd.

In a paper published fifteen years ago, Gorman et al. (Nature 391, 479–481) made precise claims about how sensitive the African wild dog is to kleptoparasitism by spotted hyaenas Crocuta crocuta and lions Panthera leo. These claims are regularly referred to in the literature, and so far, they have remained unchallenged. However, careful perusal of their paper and analysis of the available data on energy intake and expenditure by wild dogs show that their claims are unfounded. Contrary to Gorman et al., wild dogs can usually take loss of food by kleptoparasitism in their stride. We present the calculations of the energy budget of wild dogs that remain implicit in the paper by Gorman et al.

Major reorganizations in climate and tectonic regime occurred in East Asia during the Pleistocene, resulting in large-scale environmental changes. In this paper a detailed geochemical and mineralogical record of these changes is presented from a distal alluvial fan sedimentary sequence in the northern Weihe Basin. We established that, in addition to glacial-interglacial variation, there are three distinctly different units deposited over the past 1 m.y. These units are the result of variations in the overall tectonic regime in the northern Weihe Basin. Fine-grained detrital minerals were predominantly delivered during colder climatic periods, whereas evaporative minerals were dominantly deposited during the warmer, interglacial periods, probably as a result of strong seasonal contrast. This compositional variation demonstrates the importance of climate control on hinterland erosion, surface runoff, chemical weathering and evaporation. Al-normalized ratios of indicative major elements relative to average loess composition, indicate important variations in sedimentary processes, mostly related to sediment flux. Si-enrichment is an index for past flooding events, while Fe enrichment, just like K and Ti, reflects influx of clays. In contrast, Ca and Mn are strongly enriched throughout the core, associated with the authigenic precipitation of carbonates, especially during interglacial periods. The lower (~ 1000–690 ka) and upper (~ 330–0 ka) units of the core are characterized by relative intense and frequent flooding, which coincided with extensive ponding in the study area. In the middle unit (~ 690–330 ka) increased salinity levels caused by evaporation, as reflected in the high Sr/Ca ratio and dolomite abundance, led to increased carbonate precipitation. Simultaneously, the increased influx of fine sediments indicates increased clay production in the source area as a result of a more intense summer monsoon strength after 600 ka. © 2017 Elsevier B.V.

In the literature, it is well established that subjects are able to jump higher in a countermovement jump (CMJ) than in a squat jump (SJ). The purpose of this study was to estimate the relative contribution of the time available for force development and the storage and reutilization of elastic energy to the enhancement of performance in CMJ compared with SJ. Six male volleyball players performed CMJ and SJ. Kinematics, kinetics, and muscle electrical activity (EMG) from six muscles of the lower extremity were monitored. It was found that even when the body position at the start of push-off was the same in SJ as in CMJ, jump height was on average 3.4 cm greater in CMJ. The possibility that nonoptimal coordination in SJ explained the difference in jump height was ruled out: there were no signs of movement disintegration in SJ, and toe-off position was the same in SJ as in CMJ. The greater jump height in CMJ was attributed to the fact that the countermovement allowed the subjects to attain greater joint moments at the start of push-off. As a consequence, joint moments were greater over the first part of the range of joint extension in CMJ, so that more work could be produced than in SJ. To explain this finding, measured and manipulated kinematics and electromyographic activity were used as input for a model of the musculoskeletal system. According to simulation results, storage and reutilization of elastic energy could be ruled out as explanation for the enhancement of performance in CMJ over that in SJ. The crucial contribution of the countermovement seemed to be that it allowed the muscles to build up a high level of active state (fraction of attached cross-bridges) and force before the start of shortening, so that they were able to produce more work over the first part of their shortening distance.

Climate change may alter physical, chemical and biological properties of ecosystems, affecting organisms but also the fate of chemical pollutants. This study aimed to find out how changes in climate conditions (air temperature, soil moisture content) affect the toxicity of metal-polluted soils to the soft-bodied soil organism Enchytraeus crypticus, linking enchytraeid performance with changes in soil available and body metal concentrations. Bioassays with E. crypticus were performed under different combinations of air temperature (20 and 25 °C) and soil moisture content (50% and 30% of the soil water holding capacity, WHC) in dilution series of three metal-polluted soils (mine tailing, forest and watercourse). After 21 d exposure, enchytraeid reproduction was determined, and soil available (extracted with 0.01 M CaCl2) and body Cd, Cu, Pb and Zn concentrations in surviving adults were determined. In general, Cd, Pb and Zn availability decreased upon incubation under the different climate scenarios. In the watercourse soil, with initially higher available metal concentrations (678 µg Cd kg(-1), 807 µg Pb kg(-1) and 31,020 µg Zn kg(-1)), decreases were greatest at 50% WHC probably due to metal immobilization as carbonates. Enchytraeid reproduction was negatively affected by higher available metal concentrations, with reductions up to 98% in the watercourse soil compared to the control soil at 30% WHC. Bioaccumulation of Cd, Pb and Zn was higher when drier conditions were combined with the higher temperature of 25 °C. Changes in metal bioavailability and bioaccumulation explained the toxicity of soil polluted by metal mine wastes to enchytraeids under changing environmental conditions.

This empirical paper tests for trade-facilitated spillovers in the convergence of energy productivity across 16 European Union (EU) countries from 1995 to 2005. One might anticipate that by inducing specialization, trade limits the potential for convergence in energy productivity. Conversely, by inducing competition and knowledge diffusion, trade may spur sectors to greater energy productivity. Unlike most previous work on convergence, we explain productivity dynamics from cross-country interactions at a detailed sector level and apply a spatial panel data approach to explicitly account for trade-flow related spatial effects in the convergence analysis. Our study confirms the existence of convergence in manufacturing energy productivity, caused by efficiency improvements in lagging countries, while undermined by increasing international differences in sector structure. Further, we find that trade flows explain 30 to 40% of the unobserved variation in energy productivity. Trade continues to explain the unobserved variation in energy productivity even after accounting for geographic proximity. Last, we find that those countries and sectors with higher dependence on trade both have higher energy productivity growth and a higher rate of convergence, further implying that trade can enhance energy productivity. Thus, unlike concerns that trade may spur a 'race to the bottom', we find that promoting trade may help stimulate energy efficiency improvements across countries.

IntroductionBoth mean power output (MPO) and the distribution of the available energy over the race, that is, pacing strategy, are critical factors in performance. The purpose of this study was to determine the relative importance of both pacing strategy and MPO to performance.MethodsSix well-trained, regionally competitive cyclists performed four 1500-m ergometer time trials (∼2 min). For each subject, the fastest (Fast) and slowest (Slow) time trials were compared and the relative importance of differences in power output and pacing strategy were determined with an energy flow model.ResultsThe difference in final time between Fast and Slow was 4.0 (2.5) s. Fast was performed with a higher MPO (437.8 (32.3) W vs 411.3 (39.0) W), a higher aerobic peak power (295.3 (36.8) vs 287.5 (34.7) W) and a higher anaerobic peak power (828.8 (145.4) W vs 649.5 (112.2) W) combined with a relatively higher, but not statistically different anaerobic rate constant (0.051 (0.016) vs 0.041 (0.009) W). The changes in MPO (63% anaerobic, 37% aerobic) largely explained the differences in final times. Athletes chose a different pacing strategy that was close to optimal for their physiological condition in both Fast and Slow.ConclusionDifferences in intraindividual performance were mainly caused by differences in MPO. Athletes seemed to be able to effectively adjust their pacing profile based on their “status of the day”.Keywordsmodelling performance, energy expenditure, aerobic, anaerobic, sports.

Studies addressing the role of large herbivores on nitrogen cycling in grasslands have suggested that the direction of effects depends on soil fertility. Via selection for high quality plant species and input of dung and urine, large herbivores have been shown to speed up nitrogen cycling in fertile grassland soils while slowing down nitrogen cycling in unfertile soils. However, recent studies show that large herbivores can reduce nitrogen mineralization in some temperate fertile soils, but not in others. To explain this, we hypothesize that large herbivores can reduce nitrogen mineralization in loamy or clay soils through soil compaction, but not in sandy soils. Especially under wet conditions, strong compaction in clay soils can lead to periods of soil anoxia, which reduces decomposition of soil organic matter and, hence, N mineralization. In this study, we use a long-term (37-year) field experiment on a salt marsh to investigate the hypothesis that the effect of large herbivores on nitrogen mineralization depends on soil texture. Our results confirm that the presence of large herbivores decreased nitrogen mineralization rate in a clay soil, but not in a sandy soil. By comparing a hand-mown treatment with a herbivore-grazed treatment, we show that these differences can be attributed to herbivore-induced changes in soil physical properties rather than to above-ground biomass removal. On clay soil, we find that large herbivores increase the soil water-filled porosity, induce more negative soil redox potentials, reduce soil macrofauna abundance, and reduce decomposition activity. On sandy soil, we observe no changes in these variables in response to grazing. We conclude that effects of large herbivores on nitrogen mineralization cannot be understood without taking soil texture, soil moisture, and feedbacks through soil macrofauna into account.