Pollinators whose foraging habitats consist of several plant types (species or morph) may continue to choose the plant type last visited because information about the type of plant last visited dominates over all other memory contents, in particular of short-term memory. In this study, I extracted this overstrike effect on the plant choices of pollinators by analyzing patterns of visitation sequences within a single round-trip between the hive and foraging patch (bout). First, I simulated the visitation sequences within single bouts with a model to show how factors, including the bees plant-type preferences, the arrangement of plants and the effect of overstrike on short-term memory, affect visitation sequences. Here, bees are assumed to forage in a patch consisting of two plant types (H and L). The model predicts that only the effect of overstrike on short-term memory causes assorted visitation sequences according to plant type (within-bout flower constancy). That is, if the overstrike-effect on short-term memory is the primary determinant of plant choice, then bees will fly to a type-L plant after visiting a type-L plant even if they predominantly visit type-H plants and vice versa. Next, I investigated individual bumblebees visitation sequences at a patch of artificial inflorescences with a set-up similar to that assumed in the model. Two types of inflorescences were arranged on a Cartesian grid. Assorted visitation sequences according to inflorescence type were observed, depending on the distances among inflorescences. This result supports the hypotheses that bees fly to the same plant type as that last visited because short-term memory is displaced (overstruck) with information about the most recently visited plant type.Communicated by M. Giurfa 相似文献
The natural gas vehicle market is rapidly developing throughout the world, and the majority of such vehicles operate on compressed natural gas(CNG). However, most studies on the emission characteristics of CNG vehicles rely on laboratory chassis dynamometer measurements, which do not accurately represent actual road driving conditions. To further investigate the emission characteristics of CNG vehicles, two CNG city buses and two CNG coaches were tested on public urban roads and highway sections. Our results show that when speeds of 0–10 km/hr were increased to 10–20 km/hr, the CO_2, CO, nitrogen oxide(NO_x), and total hydrocarbon(THC) emission factors decreased by(71.6 ± 4.3)%,(65.6 ± 9.5)%,(64.9 ± 9.2)% and(67.8 ± 0.3)%, respectively. In this study, The Beijing city buses with stricter emission standards(Euro Ⅳ) did not have lower emission factors than the Chongqing coaches with Euro Ⅱ emission standards. Both the higher emission factors at 0–10 km/hr speeds and the higher percentage of driving in the low-speed regime during the entire road cycle may have contributed to the higher CO_2 and CO emission factors of these city buses. Additionally, compared with the emission factors produced in the urban road tests, the CO emission factors of the CNG buses in highway tests decreased the most(by 83.2%), followed by the THC emission factors, which decreased by 67.1%. 相似文献
Objective: The Useful Field of View (UFOV) assessment, a measure of visual speed of processing, has been shown to be a predictive measure of motor vehicle collision (MVC) involvement in an older adult population, but it remains unknown whether UFOV predicts commercial motor vehicle (CMV) driving safety during secondary task engagement. The purpose of this study is to determine whether the UFOV assessment predicts simulated MVCs in long-haul CMV drivers.
Method: Fifty licensed CMV drivers (Mage = 39.80, SD = 8.38, 98% male, 56% Caucasian) were administered the 3-subtest version of the UFOV assessment, where lower scores measured in milliseconds indicated better performance. CMV drivers completed 4 simulated drives, each spanning approximately a 22.50-mile distance. Four secondary tasks were presented to participants in a counterbalanced order during the drives: (a) no secondary task, (b) cell phone conversation, (c) text messaging interaction, and (d) e-mailing interaction with an on-board dispatch device.
Results: The selective attention subtest significantly predicted simulated MVCs regardless of secondary task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC in the simulated drive. The e-mail interaction secondary task significantly predicted simulated MVCs with a 4.14 times greater risk of an MVC compared to the no secondary task condition. Subtest 3, a measure of visual speed of processing, significantly predicted MVCs in the email interaction task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC during the email interaction task.
Conclusions: The UFOV subtest 3 may be a promising measure to identify CMV drivers who may be at risk for MVCs or in need of cognitive training aimed at improving speed of processing. Subtest 3 may also identify CMV drivers who are particularly at risk when engaged in secondary tasks while driving. 相似文献
Air pollution is a major obstacle to future sustainability, and traffic pollution has become a large drag on the sustainable developments of future metropolises. Here, combined with the large volume of real-time monitoring data, we propose a deep learning model, iDeepAir, to predict surface-level PM2.5 concentration in Shanghai megacity and link with MEIC emission inventory creatively to decipher urban traffic impacts on air quality. Our model exhibits high-fidelity in reproducing pollutant concentrations and reduces the MAE from 25.355 µg/m3 to 12.283 µg/m3 compared with other models. And identifies the ranking of major factors, local meteorological conditions have become a nonnegligible factor. Layer-wise relevance propagation (LRP) is used here to enhance the interpretability of the model and we visualize and analyze the reasons for the different correlation between traffic density and PM2.5 concentration in various regions of Shanghai. Meanwhile, As the strict and effective industrial emission reduction measurements implementing in China, the contribution of urban traffic to PM2.5 formation calculated by combining MEIC emission inventory and LRP is gradually increasing from 18.03% in 2011 to 24.37% in 2017 in Shanghai, and the impact of traffic emissions would be ever-prominent in 2030 according to our prediction. We also infer that the promotion of vehicular electrification would achieve further alleviation of PM2.5 about 8.45% by 2030 gradually. These insights are of great significance to provide the decision-making basis for accurate and high-efficient traffic management and urban pollution control, and eventually benefit people's lives and high-quality sustainable developments of cities. 相似文献
Background, Aims and Scope When joining the European Union on 1st May 2004, Estonia had to conform its legislation to the European Union legislation.
In relation with that, also the treatment requirements on end-of-life vehicles proceeding from Directive 2000/53/EC of the
European Parliament and of the Council of 18 September 2000 were established in Estonia for the first time. Since this area
was not regulated with law beforehand, there was not any information available about it. The aim of the current survey was
to ascertain the condition of scrap yards in mid 2004. In addition to that, also to identify the number of scrap yards operating
in Estonia, to classify these by the number of dismantled vehicles and the potential environmental hazard, and to map the
locations of car dismantling companies and evaluate their compliance with the valid requirements.
Methods The companies that have been registered in the Commercial Registry under the activity code 503090-end-of-life vehicle dismantling
were visited and visually reviewed. During the visits, the compliance of scrap yards with the existing requirements was evaluated
and it was also attempted to identify how environmentally sound the dismantling technology of every scrap yard owner is.
Results and Discussion Altogether, 63 scrap yards operated in Estonia by mid 2004. Twelve of them dismantled more than 100 vehicles, 13 of them
51-99 vehicles and 38 up to 50 vehicles a year. The total annual market capacity on dismantling of vehicles in Estonia is
considered to be approx. 10,000 units. There are very few companies dealing only with car dismantling as the main business.
Most scrap-yard owners also offer side services, e.g. haulage, car repair and maintenance. The dismantlers are interested
in the selling of second-hand spare parts and scrap metal. Only one company out of 63 complied with all the requirements enacted
by the relevant decision of the Estonian Minister of Environment. The rest of the scrap yards did not meet the requirements
on the site on storage and treatment nor did they have the hazardous waste handling licence or the waste permit. Of the requirements
established for the site for storage of end-of-life vehicles, 97% of the scrap yards were surrounded with a fence, 67% had
a 24-hour guard, 45% had covered the areas with waterproof cover, but only 3% had an oil trap. Sites for treatment were in
a somewhat better condition, these were mostly situated inside the buildings, where floors were covered with waterproof covers.
Most of the dismantlers collected the waste oil and waste fluids into separate vessels, but there were a number of dismantlers
who did not know of existence of polychlorinated biphenyls (PCB) in car air conditioning systems and the availability of mercury
in sensors belonging in passenger safety systems. Proceeding from the general condition of the scrap yard, the rest of 62
scarp yards were distributed between two empirical parameters - 'rather environmentally hazardous' or 'rather not environmentally
hazardous'. As a matter of fact, 17% of scrap yards turned out 'rather environmentally hazardous'.
Conclusion Out of the scrap yards operating in Estonia, only one is compliant with the requirements set up by Directive 2000/53/EC.
Another 62 appeared during the review to be sites of potential environmental pollution. In order to comply with environmental
requirements and get the hazardous waste treatment license, the scrap yard owners have to invest into state-of-the-art dismantling
and environment protection equipment. The main obstacle to reach the environmentally sound scrap-yard is the high investment
cost and the black market for spare parts.
Recommendation and Outlook As the correction of the market in end-of-life vehicle treatment started after the adoption of Directive 2000/53/EC, the
environmental authorities have to look after the ongoing correction. It is because there is still a demand for cheap spare
parts and it makes it attractive to dismantle the vehicles out of scrap-yards by licensees. 相似文献