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331.
Jeffrey Wielgus Leah R. Gerber Enric Sala Jeff Bennett 《Journal of environmental management》2009,90(11):3401-3409
Stated-preference surveys for the economic valuation of environmental resources typically assume no uncertainty in the hypothetical valuation scenarios. However, the outcomes of environmental policies are uncertain. We explored the effects of including information on probabilities of attribute improvement and provision in choice experiments. Our results suggest that stating explicitly a high probability for the occurrence of the valuation scenario can improve the goodness of fit of choice models and the consistency of choices. As the general public becomes more aware of the uncertainty of environmental outcomes under global change, omitting information on scenario risk may contribute to hypothetical bias and impair the validity of stated-preference valuations. 相似文献
332.
Edward Ming-Yang Wu Chia Cheng Tsai Juey Fu Cheng Shu Lung Kuo Wei Ting Lu 《Environmental Modeling and Assessment》2014,19(4):325-333
This study investigates six water quality monitoring stations in the watershed of the Feitsui Reservoir. It uses nine parameters of water quality collected in an interval of two and half years for factor analyses, which was first conducted to determine four types of factors, respectively, those for organic pollution, eutrophication, seasonal influence, and sediment pollution. The analysis results effectively help to determine water quality in the watershed of the reservoir. The authors reutilize analysis of moment structures (AMOS) to acquire further results in order to confirm the goodness of fit of the previous factor analysis model. During the confirmation, we examine the hypothesized orthogonal results as well as utilize oblique rotation to explore the goodness of fit of the reflective indicators of the orthogonal rotation. As shown in the algorithm results, as long as the covariance curve is included in the four factors, no related issues are detected in the goodness of fit of reflective indicators and interior and external quality is reported with excellence. The orthogonal model, thus, stands. Additionally, when the analysis of structural equation modeling (SEM) is conducted, sample data mismatches the hypotheses of multivariate normality. Therefore, this study adopts the generalized least square (GLS) for an algorithm. Research results of this study have been submitted to the reservoir management authorities in Taiwan for the improvement of statistical application and strategic evaluation of water quality monitoring data in order to strengthen the managerial effectiveness of water quality in watersheds. 相似文献
333.
Guor-Cheng Fang Yu-Chen Kuo Yuan-Jie Zhuang Kai-Hsiang Tsai Wen-Chuan Huang 《Environmental geochemistry and health》2017,39(4):879-887
This study characterized diurnal variations in the compositions of total suspended particulates (TSP) and dry deposits of particulates from ambient air, and the metallic elements that are contained in them at harbor, airport and farmland (HAF) sampling sites from August, 2013 to July, 2014. Two-way ANOVA of the amounts of metallic elements in the TSP and dry deposits was carried out in all four seasons at the HAF sampling sites. The metallic elements Cr and Cu originated in local emission sources at the airport. Metallic elements Zn and Pb originated in local emission sources at the harbor. Finally, metallic element Cd originated in local emissions form farmland. The following results were also obtained. (1) The metallic composition of the TSP differed significantly from that of the dry deposits in all four seasons at the harbor and farmland sampling sites, but not at the airport sampling site. (2) High correlations coefficients were found between the amounts of metallic elements Cr and Cu in the TSP and those in the dry deposits at the airport sampling site. (3) Pb was present in the TSP and the dry deposits at the harbor sampling site. 相似文献
334.
Andy J. Danylchuk Steven J. Cooke Tony L. Goldberg Cory D. Suski Karen J. Murchie Sascha E. Danylchuk Aaron D. Shultz Christopher R. Haak Edd J. Brooks Annabelle Oronti Jeff B. Koppelman David P. Philipp 《Marine Biology》2011,158(9):1981-1999
To identify the timing and location of spawning activity for bonefish (Albula spp.) in the Bahamian archipelago, we used an acoustic telemetry array spanning 44?km2 of shallow tidal creeks, flats, and adjacent deeper coastal waters near Cape Eleuthera. In two successive years, we surgically implanted transmitters in male and female bonefish (n?=?60) and examined their movement patterns within the array. Eight bonefish surgically implanted with transmitters as part of an earlier study were also tracked. In 2009, the telemetry information was complemented with snorkeling observations, underwater video, and manual tracking of the same acoustically tagged fish, as well as fish (n?=?3) gastrically implanted with continuous transmitters. During a period of 4?C7?days spanning the full and new moons, primarily between October and May, bonefish moved from their typical shallow flats and aggregated at sites in close proximity to the deep water drop-off of the Exuma Sound. Localized movements of the large schools of bonefish (often?>1,000 fish) at these presumptive pre-spawning aggregation sites included brief trips (<8?h) just after sunset until just prior to sunrise to the abyssal wall at the edge of the Exuma Sound (i.e.,?>1,000?m depth). Tagged bonefish detected at these aggregation sites were subsequently detected back in the tidal creeks and coastal flats shortly after new and full moons and remained at these more typical shallow sites (i.e.,?<2?m depth). Although we did not directly observe spawning events, we did observe ventral nudging and porpoising behaviors, which are potentially associated with courtship. Timing of the observed movements and possible courtship behaviors was coincident with periods when gametes were well developed. Collectively, our study provides the first objective evidence suggesting that the aggregation and seasonal migration of bonefish to deep shelf environments during certain moon phases is for spawning. 相似文献
335.
Review of PSR framework and development of a DPSIR model to assess greenhouse effect in Taiwan 总被引:1,自引:0,他引:1
In dealing with the complex issues of greenhouse gas (GHG) emission and climate change mitigation, many interrelated factors such as cost, level of technology development, supply and demand of energy, structure of industry, and expenditures on research and development exist. Using indicators to monitor environmental impacts and evaluate the efficacies of policies and regulations has been practiced for a long time, and it can serve as a useful tool for decision making and for comparison between different countries. Although numerous indicators have been developed for relevant subjects, integrated approaches that consider individual changes, dynamic interaction, and multi-dimensions of indicators are scarce. This paper aimed to develop a Driving Force-Pressure-State-Impact-Response (DPSIR) framework to assess the problems. This DPSIR model is mainly related to energy consumption, environmental impacts, and policy responses. The objectives of the paper were: (1) conduct a literature review on the indicators that have been used in GHG-related studies; (2) develop a DPSIR model that incorporates GHG-related indicators and evaluate their relationships using a cause?Ceffect chain of GHG emission; and (3) develop a calculative method that can be used to explain the dynamic correlation among the interdependent indicators. Taiwan is a significant source of global GHG emissions. A case study, using the developed framework and Taiwan??s actual data of the past two decades, was conducted. The results indicate that regulatory strategies for pollution control are inadequate in terms of ensuring environmental quality, and the nature does not have the capability to revert the impacts from the existing level of pollution. 相似文献
336.
本文研究了结缕草在污泥与粉煤灰构成的混合基质中的初期成活率,力求使粉煤灰场表层特性适合先锋植被生长,从而加快生态恢复速度,达到以废治污的目的。 相似文献
337.
Jeff Shimeta 《Marine Biology》2009,156(12):2451-2460
Passive suspension feeders rely on surrounding flow to deliver food particles to them. Therefore, the classic conception of
functional response (feeding rate vs. food concentration) may require modification to account for flow speed as a second independent
variable. I compared the functional response of Polydora cornuta at different velocities and determined whether food capture was proportional to particle flux (concentration × velocity).
To understand feeding responses at a mechanistic level, I measured the functional responses in terms of contact and capture
rates and determined particle retention efficiency. Experiments were run separately with two sizes of food particles, and
with juvenile or adult worms. For both worm sizes and both particle sizes, capture rate in weak flow was directly related
to concentration, but in strong flow it was constant. Worms were therefore unable to benefit from abundant food when in strong
flow. The critical velocity at which the capture rate became constant was lower for adult worms than for juvenile worms, and
it was lower for small particles than for large particles. Retention efficiency was constant among all treatments, and the
results for contact rate were essentially the same as for capture rate. Therefore, the mechanics of particle contact must
explain the effects of velocity on the functional response. Contact rate was not a constant proportion of particle flux; treatments
with similar fluxes yielded different contact rates depending on the strength of flow. The results appeared to be caused by
a velocity-induced behavioral change in appendage posture that affects contact rates: in moderate flow, worms form their feeding
palps into helical coils, which they tighten as the velocity increases. I suggest this behavior constrains suspension feeding
rates and the mechanical selection between particle sizes when worms are in strong flow, and that the effect changes with
ontogeny. Because the results are consistent with patterns in measured growth rates of P. cornuta, I hypothesize that this influence of velocity on the functional response can constrain growth and population dynamics in
this species. 相似文献
338.
339.
Louise Chuang Pao-Lin Kuo Hsiao-Bai Yang Chung-Ho Chien Pei-Yi Chen Chiung-Hsin Chang Fong-Ming Chang 《黑龙江环境通报》2003,23(2):134-137
The presence of two independent translocations in one person is rare. Herein, we report the prenatal diagnosis of two sibling fetuses with holoprosencephaly, whose father is a carrier of double translocations. The karyotype of the father is 46,XY, t(1;7) (q32;q32), t(14,15) (q32.1;q26.3). The two fetuses had variable facial dysmorphisms and identical cytogenetic abnormality—a derivative (7) t(1;7) (q32;q32) inherited from the father. The proband 1 showed a small mouth, a single median eye and a proboscis above the eye, while the proband 2 showed hypotelorism, a flat nose, cleft lip and cleft palate. Both fetuses also had alobar holoprosencephaly. Haploinsufficiency of the sonic hedgehog gene at 7q36 does account for the occurrence of holoprosencephaly in the two fetuses with a deletion of distal 7q (7q32 → qter). Copyright © 2003 John Wiley & Sons, Ltd. 相似文献