Villarini, Gabriele, James A. Smith, Mary Lynn Baeck, and Witold F. Krajewski, 2011. Examining Flood Frequency Distributions in the Midwest U.S. Journal of the American Water Resources Association (JAWRA) 47(3):447‐463. DOI: 10.1111/j.1752‐1688.2011.00540.x Abstract: Annual maximum peak discharge time series from 196 stream gage stations with a record of at least 75 years from the Midwest United States is examined to study flood peak distributions from a regional point of view. The focus of this study is to evaluate: (1) “mixtures” of flood peak distributions, (2) upper tail and scaling properties of the flood peak distributions, and (3) presence of temporal nonstationarities in the flood peak records. Warm season convective systems are responsible for some of the largest floods in the area, in particular in Nebraska, Kansas, and Iowa. Spring events associated with snowmelt and rain‐on‐snow are common in the northern part of the study domain. Nonparametric tests are used to investigate the presence of abrupt and slowly varying changes. Change‐points rather than monotonic trends are responsible for most violations of the stationarity assumption. The abrupt changes in flood peaks can be associated with anthropogenic changes, such as changes in land use/land cover, agricultural practice, and construction of dams. The trend analyses do not suggest an increase in the flood peak distribution due to anthropogenic climate change. Examination of the upper tail and scaling properties of the flood peak distributions are examined by means of the location, scale, and shape parameters of the Generalized Extreme Value distribution. 相似文献
Focusing specifically on regulation of coal-fired power plants, we examine how technological innovation by early adopters influences the timing of new environmental regulation in non-innovating countries. We build a general equilibrium model of an open economy to identify the political-economy determinants of regulation. With a newly created dataset of SO2 and NOx regulations for coal-fired power plants and a patent-based measure of the technology frontier, we estimate the determinants of environmental regulation diffusion. Our findings support the hypothesis that international economic integration eases access to environmentally friendly technologies and leads to earlier adoption, ceteris paribus, of regulation in non-innovating countries. However, we also find evidence that domestic trade protection promotes earlier adoption allowing shifts of regulatory costs to domestic consumers. Furthermore, international market power permits large countries to shift costs to foreign consumers. Other political economy factors, such as the quality of domestic coal, are also important determinants. 相似文献
The ascidian Styela clava, native to the north-west Pacific, is an invasive species affecting New Zealand’s marine ecosystems, biodiversity and aquaculture
operations. To provide detailed information on the reproductive biology of S. clava in New Zealand for post-border biosecurity management, long-term seasonal patterns of gametogenesis were determined from
May 2006 to May 2008 in Auckland’s Waitemata Harbour (36°49′20″S, 174°45′85″E). Of particular interest was whether the critical
15°C threshold spawning temperature for reproduction observed in the Northern Hemisphere applied here to the first Southern
Hemisphere study. S. clava gametogenesis followed a regular seasonal cycle with ripe gametes appearing as early as September and persisting to June;
this time frame corresponds to the period when sea surface temperatures in the region first reach 15°C and with spawning occurring
mainly during late summer to early autumn. From photoperiod manipulation, it was determined that spawning occurred at approximately
18:20. The extended reproductive period and a short generation time in the Waitemata Harbour provides a lengthy opportunity
for S. clava to spread. Findings are discussed in relation to S. clava’s post-border management. 相似文献
Despite the fact that the establishment and maintenance of blue gum plantations can potentially result in the removal of riparian vegetation, the presence of increased levels of sediments, pesticides, and nutrients, and consequently, the loss of in-stream biodiversity, few studies exist that have looked at the impacts of timber plantations on in-stream biota. The goals of this study were thus to determine water quality, riparian condition, and in-stream biodiversity values of local streams draining blue gum plantations in the Marbellup Brook catchment in Western Australia and to compare these values with those of streams associated with other land uses. Selected water quality and habitat variables and in-stream macroinvertebrate biodiversity were measured in 2006 and 2007 at 28 sites falling into five broad categories based on the predominant land use within 200 m of each study reach. Overall, the results indicated that ??blue gum plantation?? sites often had better water quality, riparian condition, and biodiversity values than ??pasture unfenced,?? and sometimes ??pasture fenced?? sites, but water quality and biodiversity values at these sites were not as good as those associated with ??remnant?? native vegetation sites. The location of the blue gum plantation sites along the disturbance gradient investigated was attributed to both present management and past land uses in the subcatchments investigated. As this study was conducted at a time when blue gum plantations were in an on-growing phase, it was recommended that future research on the impact of blue gum plantations on waterways in southwestern Australia should include an investigation of the impacts of timber clear-cutting and extraction. Longer-term cumulative and downstream effects of blue gum plantations on local waterways also need to be investigated. 相似文献
Exercise-based research interventions demonstrate reduced risk and rates of falls for community dwelling older adults; however, little is known about effective mechanisms for the translation, implementation, and maintenance of these interventions in community settings.
Method
The RE-AIM framework was used to assess the translatability of an effective exercise-based research intervention in a community setting. Questions included: Reach — Would the target population attend? Effectiveness — What was the adherence and compliance to the program? Were there individual improvements in falls risk factors? Adoption: Would staff at the center adopt the program and offer it past the funding period? Implementation — What adaptations, including optimal frequency and duration, should be made to meet the community needs, still adhere to core elements and achieve similar outcomes? Maintenance — Would the program be sustained by our community partners?
Discussion
The process of translating a controlled research intervention targeting older adults at risk of falls into a community setting was challenging. Licensed professionals developed the infrastructure to safely and effectively deliver the program. The end product was highly appealing program to our target audience, resulted in improved outcomes and was successfully adopted and maintained by the community partner.
Summary
Partnerships between community and healthcare providers are key to successful implementation of falls prevention interventions. Lessons learned from this experience can be applied to the translation of future exercise-based falls prevention interventions. 相似文献
Polychlorinated biphenyls (PCBs) were measured in raw and finished drinking water at seven Public Water Systems (PWSs) along the Hudson River as part of a baseline monitoring program prior to the extensive sediment dredging of the Upper Hudson River. Water samples were either analyzed using an Aroclor method (based on USEPA Method 508) or a congener method (Modified Green Bay Mass Balance Method). Using the congener-based method, raw water concentrations ranged from <9.3 to 164.3 ng/L and finished water concentrations ranged from <9.3 to 186.6 ng/L. Using the Aroclor method, finished water concentrations ranged from <5.0 to 200.9 ng/L. Most finished water samples above 73.0 ng/L were from a PWS with wells drilled near the river. Excluding the well data, total PCB concentrations in raw water at systems in the Upper River were similar to concentrations at systems in the Lower River, though the congener patterns differed. Paired comparison of total PCB concentrations using the two analytical methods showed good agreement, although raw water showed a different relationship than finished water. 相似文献
Recent literature suggests that a “shared politics of place” attained through joint activities fosters social integration and provides people with a means to practise co-operation [Baumann, G., 1996. Contesting culture: discourses of identity in multi-ethnic London. Cambridge: Cambridge University Press; Sanjek, R., 1998. The future of us all: race & neighbourhood policies in New York City. Ithaca, NY: Cornell University Press; Sennett, R., 2012. Together: the rituals, pleasures and politics of cooperation. UK: Penguin]. Such a “shared politics of place” is most likely to occur in the context of public space conceptualised broadly as “the setting for everyday spatial behaviour of individuals and communities, emphasizing ordinary activities of citizens” [Lownsbrough, H. and Beunderman, J., 2007. Equally spaced? Public space and interaction between diverse communities. London: Demos, p. 8]. Here we explore one element of such public space – urban agriculture sites – with a view to identifying the extent to which a “shared politics of place” can be created and nurtured among the cultivating citizenry. The paper draws on data collected on allotment gardening sites in two urban contexts: Dublin (Ireland) and Belfast (Northern Ireland) over the period 2009–2013. We demonstrate the centrality of allotment cultivation to the generation of solidarity, mutuality and trust among participating citizens. Individuals engaging in allotment gardening in both Dublin and Belfast create and sustain civil interfaces – dismantling barriers, exchanging knowledge, challenging stereotypes, generating empathy and getting on with the business of simply getting on with their lives. The modus operandi of allotment gardening is predicated on a willingness to disregard social and ethno-national categorisations while on site. This is not to deny that such differences exist and persist, but allotments offer a “space of potential” where those differences are, at least for a time, rendered less salient. 相似文献
Polylactic acid (PLA) and thermoplastic starch (TPS) are biodegradable polymers of biological origin, and the mixture of these polymers has been studied due to the desirable mechanical properties of PLA and the low processing cost of TPS. However, the TPS/PLA combination is thermodynamically immiscible due to the poor interfacial interaction between the hydrophilic starch granules and the hydrophobic PLA. To overcome these limitations, researchers studied the modification, processing, and properties of the mixtures as a strategy to increase the compatibility between phases. This review highlights recent developments, current results, and trends in the field of TPS/PLA-based compounds during the last two decades, with the main focus of improving the adhesion between the two components. The TPS/PLA blends were classified as plasticized, compatible, reinforced and with nanocomposites. This article presents, based on published research, TPS/PLA combinations, considering different methods with significant improvements in mechanical properties, with promising developments for applications in food packaging and biomedicine.
Researchers have developed methods to account for imperfect detection of species with either occupancy (presence absence) or count data using replicated sampling. We show how these approaches can be combined to simultaneously estimate occurrence, abundance, and detection probability by specifying a zero-inflated distribution for abundance. This approach may be particularly appropriate when patterns of occurrence and abundance arise from distinct processes operating at differing spatial or temporal scales. We apply the model to two data sets: (1) previously published data for a species of duck, Anas platyrhynchos, and (2) data for a stream fish species, Etheostoma scotti. We show that in these cases, an incomplete-detection zero-inflated modeling approach yields a superior fit to the data than other models. We propose that zero-inflated abundance models accounting for incomplete detection be considered when replicate count data are available. 相似文献
The pelagic yellowtail kingfish Seriola lalandi has become a target species for aquaculture in Asia and Australasia. Australasian production is reliant on larviculture from
eggs of captive brood stock; however, knowledge regarding the nutritional requirements of larvae of this species is still
scarce, particularly in relation to lipids. As a first step in establishing these requirements, eggs and larvae from captive
S. lalandi brood stock were examined for differences in total protein, total lipid and lipid classes between individual spawning events,
over the spawning season, and during larval development from fertilisation to 15 days post hatch. Results indicate that total
protein egg−1 varied significantly between individual spawning events within a season, but neither total lipid nor total protein egg−1 varied significantly across the spawning season. Brood stock egg lipids were made up of approximately 60% phospholipid, 25%
wax and/or sterol esters (WE), 15% triacylglycerol (TAG), and small amounts of sterols and free fatty acids. During the early
larval period, both WE and TAG were utilised concurrently for energy. The larvae experienced very high mortality around 5–7 days
post hatch, which coincided with very low levels of all neutral lipid classes. Although many other factors may also influence
larval mortality, these results indicate that lipid provisioning may be an important factor in larval survival during the
critical period around first-feeding in this species. Examination of ratios of TAG:ST, often used as a condition index in
fish larvae, suggested that some of the larvae were suffering from starvation. However, as egg-derived WE appears to provide
a significant source of energy during the early larval period in S. lalandi, it is suggested that WE should be included in any index of larval nutritional state. 相似文献