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61.
Reports an error in Age differences in psychosocial predictors of positive and negative affect: A longitudinal investigation of young, midlife, and older adults by Tim D. Windsor and Kaarin J. Anstey (Psychology and Aging, 2010[Sep], Vol 25[3], 641-652). Contains an error in Figure 3, on page 649. The correction discusses where to find the correct data. (The following abstract of the original article appeared in record 2010-18944-009.) Research has consistently shown that despite aging-related losses, older adults have high levels of emotional well-being relative to those in young and midlife adults. We aimed to contribute to knowledge around the factors that predict emotional well-being over the life course by examining age group differences in associations of positive and negative social exchanges and mastery beliefs with positive and negative affect in a sample of 7,472 young, midlife, and older adults assessed on 2 measurement occasions, 4 years apart. Results from structural equation models indicated lower levels of negative affect with advancing age. Mastery was consistently related to higher well-being, with the strongest associations evident for young adults. Older adults reported the most frequent positive and least frequent negative social exchanges; however, associations of social relations with affect tended to be stronger among young and midlife adults relative to older adults. Results are discussed in the context of life course perspectives on goal orientations and self-regulatory processes. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
62.
We assessed the importance of flow regime to the success of native and non‐native fish species by analysing winter/spring seining data collected from 1987 to 1997 on the resident fish communities of the lower Tuolumne River, California. The data were analysed using regression models to predict the percentage of non‐native fish at a site. The regression models included various combinations of the variables longitudinal location of the site, mean April/May stream discharge in the year of sampling, and mean April/May stream discharge in the previous year. Comparison of the models indicated that the best model included longitudinal location and stream discharge in the previous year. This model is consistent with the hypothesis that flow in the previous year differentially affects reproductive success of native and non‐native species and thus the resulting community sampled in the following winter/spring. A detrended correspondence analysis of percentage abundance species data identified a co‐occurring group of native species and a co‐occurring group of non‐native species with the non‐native red shiner (Cyprinella lutrensis) grouping separately. The differing reproductive strategies of the species were consistent with the hypothesis concerning spawning success. Our results indicate that flow regime is an important determinant of the reproductive success of native and non‐native fish species in regulated rivers. Manipulations of flow regime are a potentially powerful tool for managing native fish species, but should be considered in combination with other restoration efforts and in the context of ecosystem restoration. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
63.
Tim D. Sparks Bettina N. Bockelmann-Evans Roger A. Falconer 《Water Resources Management》2013,27(8):2989-3004
DIVAST is a two-dimensional hydrodynamic and water quality numerical model developed for estuarine and coastal modelling. The original model enables the simulation of problems such as pollution and flooding in surface waters. In this paper the existing model is extended to allow the modelling of 2-D groundwater as well as surface water in the same model, using an integrated approach rather than two disparate models. The changes to the original model are summarised and the method of implementation is outlined. The new extended model (DIVAST-SG) is then tested against an analytical solution to verify that the model solves the equations correctly. The model is shown to predict the analytical solution for two different scenarios to within approximately 1 % of the height of flood wave. 相似文献
64.
Fletcher TD Walsh CJ Bos D Nemes V RossRakesh S Prosser T Hatt B Birch R 《Water science and technology》2011,64(2):494-502
Urbanisation results in changes to runoff behaviour which, if not addressed, inevitably degrade receiving waters. To date, most stormwater management has focussed on the streetscape and public open space. Given that much of the catchment imperviousness is located on private land, we developed and tested a novel economic instrument (a uniform price auction) for encouraging allotment-scale stormwater retention. We evaluated bids using an integrated environmental benefit index (EBI), based on the ability of the proposed works to reduce runoff frequency, pollutant loads and to reduce potable water demand. The uniform price auction resulted in 1.4 ha of impervious areas being effectively 'disconnected' from the stormwater system. The EBI provided an objective and transparent method of comparing bids, which varied in the type of works proposed (e.g. rainwater tank, rain-garden), the cost and the resulting environmental benefit. Whilst the pilot auction was a success, the public subsidy of works undertaken was around 85%, meaning that property owners a relatively small private benefit in the works. Future auction rounds will be revised to (i) test an EBI which is more focussed on the protection of streams (assessing changes to runoff frequency, baseflow volumes and water quality) and (ii) provide an auction process which is simpler to understand, and provides greater practical support for landholders who wish to undertake works. 相似文献
65.
Modelling the effects of dam removal on migratory walleye (Sander vitreus) early life‐history stages
Many dams in the USA have outlived their intended purpose and an increasing number are being considered for removal. Yet, quantitative studies of the potential physical, biological and ecological responses are needed to assess dam removal decisions. In this paper, the responses of migratory walleye (Sander vitreus) to increased spawning habitat availability as a result of dam removal was studied by comparing scenarios with and without a high‐head dam in the Sandusky River (Ohio), a major tributary to Lake Erie. A conceptual, ecological model was proposed to define the relationship between hydrodynamics and walleye spawning, egg hatching, larval drift and survival. A mathematical, ecological model of the early life‐history stages was then developed and coupled with time series of depth and velocity predictions over the spawning grounds from a 1‐D hydrodynamic model. Model simulations were run for 1984–1993 for both the with‐ and without‐dam scenarios to assess the potential benefit of dam removal. The simulation results demonstrated that velocity, depth and water temperature are major factors influencing adult walleye spawning success. Without the dam, 10 times the amount of spawning habitat would be available for walleye to spawn. This increase in spawning habitat area resulted in up to five times the total egg deposition and seven times the larval output to the nursing grounds, based on the assumption that 5% of the walleye population of Lake Erie migrated up the Sandusky River to spawn. We concluded that the spawning habitat in the current condition (with the dam) is limiting and additional spawning habitat upstream could significantly increase the number of larval walleye drifting to Lake Erie. The model sensitivity analysis showed that the number of walleye migrating up the river in spring is the dominant factor for larval recruitment to the lake. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
66.
Ohne Zusammenfassung Zuschriften zum Studierendenforum bitte an: Universit?t Bayreuth, Lehrstuhl BWL VII (Wirtschaftsinformatik), Prof. Dr. Torsten Eymann, Redaktion Studierendenforum, z. Hd. Dipl.-Wirtschaftsinformatiker Stefan K?nig, Universit?tsstra?e 30, 95447 Bayreuth, stefan.koenig@uni-bayreuth.de 相似文献
67.
68.
The incident of concern involves a tour bus that caught fire. The fire took place while the bus was traveling at highway speeds. Bus fires can be catastrophic, consuming the entire vehicle and threatening the lives of passengers. In this case, the fire was detected soon enough to allow the bus to be evacuated. Further, the fire was extinguished in sufficient time to allow the origin of the fire to be traced by burn patterns to the brake assembly at the passenger’s side rear axle. With the origin established, it remained consequential to determine the cause. It was here that metallurgical analysis came into play. Two competing theories as to the cause were presented. One theory was that heat generated by a dragging brake ignited the adjacent tire. The dragging brake, in turn, would have been the result of a leak in the air line servicing the brake. The second theory was that an underinflated tire had overheated and ignited. To prove if either theory was correct, the brake drum was subjected to metallurgical examination. It so happened that the changes in microstructure of the drum material as a function of location and of temperature exposure verified that the dragging brake theory was correct. It is also important to realize that a correct and well-documented analysis provided knowledge as to the cause of the fire and is one step in preventing another such fire. This article was published in Materials Science & Technology 2007 Conference and Exhibition: Exploring Structure, Processing, and Applications Across Multiple Materials Systems (Detroit, MI), September 17–20, 2007, What We Can Learn from Failure Analysis Symposium, ASM International, Materials Park, OH, 2007. 相似文献
69.
70.
Catherine A Woolnough Tim Charlton Lachlan H Yee Maria Sarris L John R Foster 《Polymer International》2008,57(9):1042-1051
BACKGROUND: Despite the recognition that microbial biofilms play a role in environmental degradation of bioplastics, few studies investigate the relationship between bioplastic biodegradation and microbial colonisation. We have developed protocols based on a combination of confocal laser scanning microscopy and contact angle goniometry to qualitatively and quantitatively map surface changes due to biofilm formation and biopolymer degradation of solvent cast poly(3‐hydroxyalkanoate) films in an accelerated in vitro biodegradation system. RESULTS: A significant regression relationship between biofilm formation and polymer biodegradation (R2 = 0.96) was primarily conducted by cells loosely attached to the film surfaces (R2 = 0.95), rather than the strongly attached biofilm (R2 = 0.78). During biodegradation the surface rugosity of poly(3‐hydroxybutyrate) and poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] increased by factors of 1.5 and 1.76, respectively. In contrast, poly(3‐hydroxyoctanoate) films showed little microbial attachment, negligible weight loss and insignificant changes in surface rugosity. CONCLUSION: A statistically significant link is established between polymer weight loss and biofilm formation. Our results suggest that this degradation is primarily conducted by cells loosely attached to the polymer rather than those strongly attached. Biofilm formation and its type are dependent upon numerous factors; the flat undifferentiated biofilms observed in this study produce a gradual increase in surface rugosity, observed as an increase in waviness. Copyright © 2008 Society of Chemical Industry 相似文献