Particulate and water-soluble agents were tested to determine their ability to affect the relationship between metal toxicity and the survival of Euchaeta japonica (Copepoda, Calanoida). Clay minerals and diatoms were two types of particles capable of affecting this relationship. Ascorbic acid, sewage effluent, and water extracts of humic acid and two types of soils exhibited the same capability. The ability of the water-soluble agents was compared with that of a known chelating agent in an attempt to quantify the activity of the agents. 相似文献
A comprehensive understanding of sexual selection requires knowledge of the traits and mechanisms responsible for increasing a male’s paternity share (proportion of progeny sired) relative to that of other males mating with the same female. In this study we manipulated by starvation the expression of traits that might influence male paternity share in Tribolium castaneum. We then conducted experiments to examine how male starvation affects male performance during sequential episodes of sexual selection from mating to progeny production, and investigated female control over specific stages by using live vs dead females. Comparison of starved vs fed males revealed that T. castaneum females have control over spermatophore transfer during mating, as live females rejected inseminations by starved (“low quality”) males. None of the measured male copulatory behaviors (leg-rubbing frequency, asymmetry, and percent of time spent rubbing) affected the probability of successful insemination, but the last two were positively associated with male paternity share. Spermatophore positioning within the female reproductive tract was not affected by male treatment (starved/fed), by female treatment (live/dead), or by male copulatory behaviors. Starvation, however, had a dramatic effect on male reproductive physiology, decreasing both accessory gland size and total number of sperms transferred (but not sperm viability in seminal vesicles). In addition, females who mated to starved males stored fewer sperms in their spermathecae, which, together with decreased ejaculate size, may explain the reduced paternity share of starved males compared to fed males. This study elucidates some cryptic mechanisms influencing male reproductive success and aids our understanding of trait evolution through sexual selection. 相似文献
Objective: Self-report measures are typically used to assess the effectiveness of road safety advertisements. However, psychophysiological measures of persuasive processing (i.e., skin conductance response [SCR]) and objective driving measures of persuasive outcomes (i.e., in-vehicle Global Positioning System [GPS] devices) may provide further insights into the effectiveness of these advertisements. This study aimed to explore the persuasive processing and outcomes of 2 anti-speeding advertisements by incorporating both self-report and objective measures of speeding behavior. In addition, this study aimed to compare the findings derived from these different measurement approaches.
Methods: Young drivers (N = 20, M age = 21.01 years) viewed either a positive or negative emotion–based anti-speeding television advertisement. While viewing the advertisement, SCR activity was measured to assess ad-evoked arousal responses. The RoadScout GPS device was then installed in participants' vehicles for 1 week to measure on-road speed-related driving behavior. Self-report measures assessed persuasive processing (emotional and arousal responses) and actual driving behavior.
Results: There was general correspondence between the self-report measures of arousal and the SCR and between the self-report measure of actual driving behavior and the objective driving data (as assessed via the GPS devices).
Conclusions: This study provides insights into how psychophysiological and GPS devices could be used as objective measures in conjunction with self-report measures to further understand the persuasive processes and outcomes of emotion-based anti-speeding advertisements. 相似文献
Motor graders are a common type of nonroad vehicle used in many road construction and maintenance applications. In-use activity, fuel use, and emissions were measured for six selected motor graders using a portable emission measurement system. Each motor grader was tested with petroleum diesel and B20 biodiesel. Duty cycles were quantified in terms of the empirical cumulative distribution function of manifold absolute pressure (MAP), which is an indicator of engine load. The motor graders were operated under normal duty cycles for road maintenance and repair at various locations in Wake and Nash Counties in North Carolina. Approximately 3 hr of quality-assured, second-by-second data were obtained during each test. An empirical modal-based model of vehicle fuel use and emissions was developed, based on stratifying the data with respect to ranges of normalized MAP, to enable comparisons between duty cycles, motor graders, and fuels. Time-based emission factors were found to increase monotonically with MAP. Fuel-based emission factors were mainly sensitive to differences between idle and non-idle engine operation. Cycle average emission factors were estimated for road "resurfacing," "roading," and "shouldering" activities. On average, the use of B20 instead of petroleum diesel leads to a negligible decrease of 1.6% in nitric oxide emission rate, and decreases of 19-22% in emission rates of carbon monoxide, hydrocarbons, and particulate matter. Emission rates decrease significantly when comparing newer engine tier vehicles to older ones. Significant reductions in tailpipe emissions accrue especially from the use of B20 and adoption of newer vehicles. 相似文献
The semiconductor industry plays a leading role in supporting economic stabilization and social progress in Taiwan. In this paper, Eco-indicator 95 and Impact 2002+ are utilized to evaluate the potential environmental impacts from five production processes of the double data rate synchronous dynamic random access memory (DDR SDRAM). The comparisons between these two impact methods and their scopes are also discussed.From our results, global warming potential and non-renewable energy consumption were identified as the major environmental impacts. Applications of Eco-indicator 95 and IMPACT 2002+ also suggest that summer smog and respiratory inorganics are significant impact categories. The comparison of the scopes of these two methods identifies that low GWP potential PFCs substitution and electricity saving are effective ways to decrease environmental impacts of DRAM manufacturing. In addition, IMPACT 2002+ is a more applicable LCA method for the semiconductor industry in Taiwan due to the structure and reference area of this method and the characteristics of the semiconductor industry in Taiwan. 相似文献
Two means by which climate change may increase surface soil erosion in mountainous terrain are: (1) increasing the frequency of extreme rainfall events and (2) decreasing the duration of snow cover on bare soil. We used output from four general circulation models (GCMs) and two greenhouse gas trajectories to produce a suite of hydrologic variables at a daily time‐step for historic and projected 21st Century conditions. We statistically disaggregated the daily rainfall to hourly, using hourly rainfall from a network of nine weather stations in the Tahoe Basin, and filtered out rain falling on a snowpack. We applied published equations to convert hourly intensity to raindrop kinetic energy (KE) for each day and grid cell in the Basin, averaged across grid cells, and created time series of total annual and maximum annual hourly kinetic energy (TKE and MKE) on snow‐free ground. Using the Generalized Extreme Value distribution, we calculated the significance of long‐term trends in KE on snow‐free ground, and estimated energy levels for return periods of 2, 20, and 100 years. We then detrended the snowpack data and compared the resulting trends in KE with the trends resulting from changes in both rainfall energy and snowpack under two GCMs. Principal findings include (1) upward trends in MKE, (2) stronger upward trends in TKE; and (3) an effect of increasing rainfall intensities on KE in some cases, and a strong effect of reduced snowpack in all cases examined. 相似文献
Summary The mitigation of natural disasters essentially depends upon the identification and adjustment of human ecological processes
contributing to conditions of vulnerability. The analysis of vulnerability requires the local study of political, social,
and economic processes which have contributed, and are contributing, to a vulnerable condition in a hazardous environment.
One of the few similarities between Tonga and Algeria is a continuing experience of natural disaster after independence from
previous colonial administrations. In two very different but complementary projects, ways are identified for the adjustment
of assumed or inherited priorities for development, to take practical account of continuing hazards. The high vulnerability
of rural areas is a factor common to both countries, as well as to many others. The analysis of conditions and systems in
two dissimilar countries may have begun a process of implementation, one which must necessarily follow theoretical analysis
for the realisation of practical value. The degree and nature of disaster impact is conditioned as much by normally prevailing
conditions and systems as by the manifestation of natural hazard. Direct experience of hazardous environments, and of problems
caused by disaster, must be made to result in the creation of multi-disciplinary environmental policies for disaster mitigation,
inclusive of small scale development and education and training programmes for continued implementation. Comprehensive and
simultaneous strategies for disaster avoidance, disaster resistance, and disaster accomodation must be made integral components
of local development planning. 相似文献
Summary The occurrence of disastrous manifestations of hazard are not usually unique events. In analysis of the causes and effects
of these occurrences there are problems for analysts, academics and policy-makers in the understanding of long-term perspectives
as the context for recent events and future policies. Understanding will be made initially, but necessarily, more complex
by the variety of standpoints of different interest groups in the affected community, and of the community at large.
Physical permanence of a community cannot beassumed in a changing environmental condition. Vulnerability to the sea has increased during the thousand years of Chiswell's existence,
and is continuing to do so. Understanding of this changing state by various groups in society, and their administrators, is
the key to the selection and effectiveness of interacting social and technological measures whether undertaken specifically
against hazard or not.
The extent to which technology can be effectively mobilised and implemented to ensure prolonged community permanence may only
be assessed by detailed analysis of environmental phenomena on the one hand, and by comparison with social adjustments on
the other. Social adjustments cannot be compared until those options are made realistically available by the authorities elected
for their administration.
The condition of vulnerability is not static. Analysis and assessment of short- and longer-term issues is at once a multi-disciplinary
process calling for a fusion of physical and earth sciences, social sciences, and political and administrative processes.
That these sciences and processes are themselves evolving, and are not static, is as true as for vulnerability itself. That
all are in short- and long-term processes of change must be understood if each is to be integrated with the other for maximum
comprehensive and effective response to natural hazard. 相似文献
It is gratifying to report that 1975-1976 has been another year of increased activity for the Air Pollution Control Association, and various indicators are positive compared to previous years. Membership has increased, attendance at meetings has increased, we have a substantial surplus to report, there is increased activity in membership interest and in our overall activity. Public affairs involvement has increased somewhat, as have our international activities. Local sections and technical committees have expanded their scope of productive involvement. Clearly, APCA has had a successful and productive year. 相似文献