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581.
582.
Consistent success in encouraging stair climbing on public access staircases contrasts with equivocal evidence for effectiveness in worksites. This paper tests whether contextual factors may affect stair/elevator choice. The study investigated the impact of elevator availability, pedestrian traffic (number using the elevator and stairs per minute), building occupancy (total individuals in the building) and time of day on stair ascent and descent in a workplace. Stair and elevator choices were monitored by automatic counters every weekday during two phases. In a natural experiment, days with four available elevators were compared with days when three elevators were available. Stair use increased for three elevators compared to four. Increasing building occupancy was associated with increased stair use, whilst increasing pedestrian traffic and time of day was associated with reduced stair use. A follow-up study revealed complimentary effects of building occupancy and time of day on elevator waiting times, indicating that increased stair use by contextual factors reflects increased elevator waiting times. In contrast, shorter waiting times are likely when momentary pedestrian traffic is high and later in the day. Crucially, the magnitude of the effects of these contextual factors was ten times larger than previously reported effects of stair climbing interventions. 相似文献
583.
The influence of explosive wastes in soil on the reproduction of the springtailFolsomia candida (Willem 1902) (insects of the Order Collembola) was investigated in a standard test according to ISO-Draft-Guideline 11268-2. In the test, we used soils with 3 different contamination levels from an area used for different military purposes (in Hallschlag, Germany), especially for explosive operations, since the beginning of the century. We found different and heterogenous mixtures of contaminants in the soils (primarily TNT and DNT) which resulted in a high mortality rate among the adult insects and in a dramatic reduction in the reproductive potential of the Collembola. In the mixture of contaminants with the highest contamination levels, the total extinction of exposed Collembola was observed as a result of the death of adult insects. 相似文献
584.
Tobias Hahn Frank Figge Andrea Liesen Ralf Barkemeyer 《Journal of environmental management》2010,91(10):1997-2007
In this paper, we propose the return-to-cost-ratio (RCR) as an alternative approach to the analysis of operational eco-efficiency of companies based on the notion of opportunity costs. RCR helps to overcome two fundamental deficits of existing approaches to eco-efficiency. (1) It translates eco-efficiency into managerial terms by applying the well-established notion of opportunity costs to eco-efficiency analysis. (2) RCR allows to identify and quantify the drivers behind changes in corporate eco-efficiency. RCR is applied to the analysis of the CO2-efficiency of German companies in order to illustrate its usefulness for a detailed analysis of changes in corporate eco-efficiency as well as for the development of effective environmental strategies. 相似文献
585.
Billy E. Johnson Pierre Y Julien Darcy K Molnar Chester C. Watson 《Journal of the American Water Resources Association》2000,36(1):31-42
ABSTRACT: The two‐dimensional soil erosion model CASC2D‐SED simulates the dynamics of upland erosion during single rainstorms. The model is based on the raster‐based surface runoff calculations from CASC2D. Rainfall precipitation is distributed in time and space. Infiltration is calculated from the Green‐Ampt equations. Surface runoff is calculated from the diffusive wave approximation to the Saint‐Venant equations in two‐dimensions. Watershed data bases in raster Geographical Information System (GIS) provide information on the soil type, size fractions, soil erodibility, cropping management, and conservation practice factors for soil erosion calculations. Upland sediment transport is calculated for the size fractions (sand, silt, and clay), and the model displays the sediment flux, the amount of suspended sediment, and the net erosion and deposition using color graphics. The model has been tested on Goodwin Creek, Mississippi. The peak discharge and time to peak are within ± 20 percent and sediment transport rates within ?50 percent to 200 percent. 相似文献
586.
Alan E. Donnenfeld MD Johanna van de Woestune Frank Craparo Catherine S. Smith Avi Ludomirsky Stuart Weiner 《黑龙江环境通报》1991,11(4):235-244
Experience with three prenatally diagnosed pregnancies complicated by an acardiac twin reveals that ultrasonography and echocardiography are helpful in detecting early signs of in-utero congestive heart failure in the normal twin. The use of Doppler blood flow analysis to determine direction of blood flow, post-mortem placental and fetal angiography, and umbilical cord blood gas determination provided proof that retrograde arterial perfusion occurs in the acardiac fetus. In a fourth pregnancy, an experimental approach to occlude the acardiac twin's umbilical cord was attempted, but was unsuccessful. 相似文献
587.
Kliucininkas L Martuzevicius D Krugly E Prasauskas T Kauneliene V Molnar P Strandberg B 《Journal of environmental monitoring : JEM》2011,13(1):182-191
This complex study presents indoor and outdoor levels of air-borne fine particles, particle-bound PAHs and VOCs at two urban locations in the city of Kaunas, Lithuania, and considers possible sources of pollution. Two sampling campaigns were performed in January-February and March-April 2009. The mean outdoor PM(2.5) concentration at Location 1 in winter was 34.5 ± 15.2 μg m(-3) while in spring it was 24.7 ± 12.2 μg m(-3); at Location 2 the corresponding values were 36.7 ± 21.7 and 22.4 ± 19.4 μg m(-3), respectively. In general there was little difference between the PM concentrations at Locations 1 and 2. PM(2.5) concentrations were lower during the spring sampling campaign. These PM concentrations were similar to those in many other European cities; however, the levels of most PAHs analysed were notably higher. The mean sum PAH concentrations at Locations 1 and 2 in the winter campaign were 75.1 ± 32.7 and 32.7 ± 11.8 ng m(-3), respectively. These differences are greater than expected from the difference in traffic intensity at the two sites, suggesting that there is another significant source of PAH emissions at Location 1 in addition to the traffic. The low observed indoor/outdoor (I/O) ratios indicate that PAH emissions at the locations studied arise primarily from outdoor sources. The buildings at both locations have old windows with wooden frames that are fairly permissive in terms of air circulation. VOC concentrations were mostly low and comparable to those reported from Sweden. The mean outdoor concentrations of VOC's were: 0.7 ± 0.2, 3.0 ± 0.8, 0.5 ± 0.2, 3.5 ± 0.3, and 0.2 ± 0.1 μg m(-3), for benzene, toluene, ethylbenzene, sum of m-, p-, o-xylenes, and naphthalene, respectively. Higher concentrations of VOCs were observed during the winter campaign, possibly due to slower dispersion, slower chemical transformations and/or the lengthy "cold start" period required by vehicles in the wintertime. A trajectory analysis showed that air masses coming from Eastern Europe carried significantly higher levels of PM(2.5) compared to masses from other regions, but the PAHs within the PM(2.5) are of local origin. It has been suggested that street dust, widely used for winter sanding activities in Eastern and Central European countries, may act not only as a source of PM, but also as source of particle-bound PAHs. Other potential sources include vehicle exhaust, domestic heating and long-range transport. 相似文献
588.
Oliver?HawlitschekEmail authorView authors OrcID profile Mark?D.?Scherz Bernhard?Ruthensteiner Angelica?Crottini Frank?Glaw 《Die Naturwissenschaften》2018,105(7-8):49
Cryptic species have been detected in many groups of organisms and must be assumed to make up a significant portion of global biodiversity. We study geckos of the Ebenavia inunguis complex from Madagascar and surrounding islands and use species delimitation algorithms (GMYC, BOLD, BPP), COI barcode divergence, diagnostic codon indels in the nuclear marker PRLR, diagnostic categorical morphological characters, and significant differences in continuous morphological characters for its taxonomic revision. BPP yielded ≥?10 operational taxonomic units, whereas GMYC (≥?27) and BOLD (26) suggested substantial oversplitting. In consequnce, we resurrect Ebenavia boettgeri Boulenger 1885 and describe Ebenavia tuelinae sp. nov., Ebenavia safari sp. nov., and Ebenavia robusta sp. nov., increasing the number of recognised species in Ebenavia from two to six. Further lineages of Ebenavia retrieved by BPP may warrant species or subspecies status, but further taxonomic conclusions are postponed until more data become available. Finally, we present an identification key to the genus Ebenavia, provide an updated distribution map, and discuss the diagnostic values of computational species delimitation as well as morphological and molecular diagnostic characters. 相似文献
589.
Arjan M. Boonman Martijn Boonman Frank Bretschneider Wim A. van de Grind 《Behavioral ecology and sociobiology》1998,44(2):99-107
Daubenton's bat, a trawling vespertilionid bat species, hunts for insects that fly close to, or rest on, the water surface.
During summer, many ponds at which Daubenton's bats hunt become gradually covered with duckweed. The purpose of this study
was to investigate the effects of duckweed cover on the hunting behaviour of Daubenton's bats and on the ultrasound-reflecting
properties of the water surface. Our study revealed the following. (1) Daubenton's bat avoids water surfaces covered with
duckweed. (2) Prey abundance was related to the number of foraging Daubenton's bats but was independent of duckweed cover.
(3) When mealworms were presented among standardized amounts of duckweed to naturally foraging Daubenton's bats, they caught
significantly less mealworms when the duckweed cover was increased. (4) Measurements with ultrasonic signals show that a water
surface covered with duckweed returns a much stronger background echo at small angles (i.e. parallel to the water surface)
compared to an uncovered water surface. It seems likely that a cover of duckweed on the water surface interferes with prey
detection by masking the echoes returning from prey. (5) It was relatively difficult for the bats to discriminate small patches
of duckweed from mealworms. The proposed discrimination mechanism for this trawling bat species suggests that single duckweed
patches can also be mistaken for natural prey by Daubenton's bats.
Received: 4 January 1998 / Accepted after revision: 19 July 1998 相似文献
590.
Marine organisms are exposed to increasingly acidic oceans, as a result of equilibration of surface ocean water with rising
atmospheric CO2 concentrations. In this study, we examined the physiological response of Mytilus edulis from the Baltic Sea, grown for 2 months at 4 seawater pCO2 levels (39, 113, 243 and 405 Pa/385, 1,120, 2,400 and 4,000 μatm). Shell and somatic growth, calcification, oxygen consumption
and
\textNH4 + {\text{NH}}_{4}^{ + } excretion rates were measured in order to test the hypothesis whether exposure to elevated seawater pCO2 is causally related to metabolic depression. During the experimental period, mussel shell mass and shell-free dry mass (SFDM)
increased at least by a factor of two and three, respectively. However, shell length and shell mass growth decreased linearly
with increasing pCO2 by 6–20 and 10–34%, while SFDM growth was not significantly affected by hypercapnia. We observed a parabolic change in routine
metabolic rates with increasing pCO2 and the highest rates (+60%) at 243 Pa.
\textNH4 + {\text{NH}}_{4}^{ + } excretion rose linearly with increasing pCO2. Decreased O:N ratios at the highest seawater pCO2 indicate enhanced protein metabolism which may contribute to intracellular pH regulation. We suggest that reduced shell growth
under severe acidification is not caused by (global) metabolic depression but is potentially due to synergistic effects of
increased cellular energy demand and nitrogen loss. 相似文献