An insight into the drag effect of water,land, and energy on economic growth across space and time: the application of improved Solow growth model

Environmental Science and Pollution Research - Economies that depend on natural resources can experience a resource drag effect when economic growth is limited by constraints on the availability of...     

Importance of Sediment–Water Interactions in Coeur d’Alene Lake,Idaho, USA: Management Implications

A field study at Coeur dAlene Lake, Idaho, USA, was conducted between October 1998 and August 2001 to examine the potential importance of sediment–water interactions on contaminant transport and to provide the first direct measurements of the benthic flux of dissolved solutes of environmental concern in this lake. Because of potential ecological effects, dissolved zinc and orthophosphate were the solutes of primary interest. Results from deployments of an in situ flux chamber indicated that benthic fluxes of dissolved Zn and orthophosphate were comparable in magnitude to riverine inputs. Tracer analyses and benthic-community metrics provided evidence that solute benthic flux were diffusion-controlled at the flux-chamber deployment sites. That is, effects of biomixing (or bioturbation) and ground-water interactions did not strongly influence benthic flux. Remediation efforts in the river might not produce desired water-quality effects in the lake because imposed shifts in concentration gradients near the sediment–water interface would generate a benthic feedback response. Therefore, development of water-quality models to justify remediation strategies requires consideration of contaminant flux between the water column and underlying sediment in basins that have been affected by long-term (decadal) anthropogenic activities.     

Material investment and prey capture potential of reduced spider webs

Summary The webs of Miagrammopes animotus have a simple structure and variable form. However, both the length of their lines and the total surface area of their capture threads are closely associated with spider size. These spiders' ability to deposit both linear and looped cribellar capture threads along a web's diverging capture lines plays an important role in establishing these relationships. Looped capture threads have the greater surface area and are more prominent in the webs of older spiders where they increase a web's surface area and enhance its ability to retain prey. The predicted performance of these webs is supported by comparisons of the stickiness of their threads and a survey of the prey their owners capture. Cribellar thread stickiness increases with spider size, and larger spiders capture prey that have greater masses.     

Ecological analysis of disturbed riverbanks in the Montréal area of Québec

In revegetation trials on disturbed riverbank sites in the Montréal region (Québec, Canada), an analysis of their structure by means of their biotic and abiotic components was undertaken. Vegetation sampling and physical surveys, together with soil analyses of 62 stands, grouped in 20 sectors, were carried out in the summer of 1986. The statistical analyses of biotic and abiotic data were executed in parallel by a hierarchical agglomerative cluster analysis (arithmetic average clustering) and by an ordination in reduced space (principal coordinate analysis). The species colonizing these riverbanks are, for the most part, ruderals from the Montréal region, of which more than 50% are introduced species. The pioneering communities characterizing these artificial habitats have had very little impact on the physical conditions of their environment; therefore, the ordination on the plant communities proves to be strongly correlated to the ordination stemming from the abiotic components. The statistical analysis retains the original sectors, underlining the fact that each human intervention generally results in the creation of a particular ecological situation.     

Country specific low carbon commitments versus equitable and practical company specific decarbonisation targets

Environment, Development and Sustainability - Concerns about the impact of climate change and the need for stabilising a global temperature rise to below 2 degrees Celsius are driving the...     

Real-world vehicle emissions: a summary of the twelfth Coordinating Research Council On-Road Vehicle Emissions Workshop

The Coordinating Research Council (CRC) held its 12th workshop in April 2002, with nearly 90 presentations on the most recent on-road vehicle emissions research. This paper summarizes the presentations from researchers who are engaged in improving understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed mobile source emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emissions control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.     

Seasonal changes in the structure of rhesus macaque social networks

Social structure emerges from the patterning of interactions between individuals and plays a critical role in shaping some of the main characteristics of animal populations. The topological features of social structure, such as the extent to which individuals interact in clusters, can influence many biologically important factors, including the persistence of cooperation, and the rate of spread of disease. Yet, the extent to which social structure topology fluctuates over relatively short periods of time in relation to social, demographic, or environmental events remains unclear. Here, we use social network analysis to examine seasonal changes in the topology of social structures that emerge from socio-positive associations in adult female rhesus macaques (Macaca mulatta). Behavioral data for two different association types (grooming and spatial proximity) were collected for females in two free-ranging groups during two seasons: the mating and birth seasons. Stronger dyadic bonds resulted in social structures that were more tightly connected (i.e., of greater density) in the mating season compared to the birth season. Social structures were also more centralized around a subset of individuals and more clustered in the mating season than those in the birth season, although the latter differences were mostly driven by differences in density alone. Our results suggest a degree of temporal variation in the topological features of social structure in this population. Such variation may feed back on interactions, hence affecting the behaviors of individuals, and may therefore be important to take into account in studies of animal behavior.     

Cross-combined composite sampling designs for identification of elevated regions

Analyzing soils for contaminants can be costly. Generally, discrete samples are gathered from within a study area, analyzed by a laboratory and the results are used in a site-specific statistical analysis. Because of the heterogeneities that exist in soil samples within study areas, a large amount of variability and skewness may be present in the sample population. This necessitates collecting a large number of samples to obtain reliable inference on the mean contaminant concentration and to understand the spatial patterns for future remediation. Composite, or Incremental, sampling is a commonly applied method for gathering multiple discrete samples and physically combining them, such that each combination of discrete samples requires a single laboratory analysis, which reduces cost and can improve the estimates of the mean concentration. While incremental sampling can reduce cost and improve mean estimates, current implementations do not readily facilitate the characterization of spatial patterns or the detection of elevated constituent regions within study areas. The methods we present in this work provide efficient estimation and inference for the mean contaminant concentration over the entire spatial area and enable the identification of high contaminant regions within the area of interest. We develop sample design methodologies that explicitly define the characteristics of these designs (such as sample grid layout) and quantify the number of incremental samples that must be obtained under a design criteria to control false positive and false negative (Type I and II) decision errors. We present the sample design theory and specifications as well as results on simulated and real data.     

Hydrologic monitoring tools for freshwater municipal planning in the Arctic: the case of Iqaluit,Nunavut, Canada

Freshwater and the services it provides are vital to both natural ecosystems and human needs; however, extreme climates and their influence on freshwater availability can be challenging for municipal planners and engineers to manage these resources effectively. In Arctic Canada, financial and human capital limitations have left a legacy of freshwater systems that underserve current communities and may be inadequate in the near future under a warming climate, growing population, and increasing demand. We address this challenge to community water resource planning by applying several novel water supply forecasting methods to evaluate the Apex River as an alternative freshwater source for Iqaluit, Nunavut (Canada). Surveys of water isotope composition of the Apex River and tributaries indicated that rainfall is the main source of water replenishment. This information was utilized to calibrate a water resource assessment that considered climate forecasting scenarios and their influence on supply, and alternative scenarios for freshwater management to better adapt to a changing climate. We found that under current climate and demand conditions, the freshwater supply of Iqaluit would be in a perpetual state of drawdown by 2024. Analysis of current infrastructure proposals revealed significant deficiencies in the supply extensions proposed whereby the Apex replenishment pipeline would only provide a 2-year extension to current municipal supply. Our heuristic supply forecast methods allowed for several alternative supply strategies to be rapidly evaluated, which will aid the community planning process by specifically quantifying the service life of the city’s current and future primary water supply.     

Dust events and their influence on aerosol optical properties over Jaipur in Northwestern India

In this study, we systematically document the link between dust episodes and local scale regional aerosol optical properties over Jaipur located in the vicinity of Thar Desert in the northwestern state of Rajasthan. The seasonal variation of AOT_{500 nm} (aerosol optical thickness) shows high values (0.51?±?0.18) during pre-monsoon (dust dominant) season while low values (0.36?±?0.14) are exhibited during winter. The Ångström wavelength exponent has been found to exhibit low value (<0.25) indicating relative dominance of coarse-mode particles during pre-monsoon season. The AOT increased from 0.36 (April_mean) to 0.575 (May–June_mean). Consequently, volume concentration range increases from April through May–June followed by a sharp decline in July during the first active phase of the monsoon. Significantly high dust storms were observed over Jaipur as indicated by high values of single scattering albedo (SSA_{440 nm}?=?0.89, SSA_{675 nm}?=?0.95, SSA_{870 nm}?=?0.97, SSA_{1,020 nm}?=?0.976) than the previously reported values over IGP region sites. The larger SSA values (more scattering aerosol), especially at longer wavelengths, is due to the abundant dust loading, and is attributed to the measurement site’s proximity to the Thar Desert. The mean and standard deviation in SSA and asymmetry parameter during pre-monsoon season over Jaipur is 0.938?±?0.023 and 0.712?±?0.017 at 675 nm wavelength, respectively. Back-trajectory air mass simulations suggest Thar Desert in northwestern India as the primary source of high aerosols dust loading over Jaipur region as well as contribution by long-range transport from the Arabian Peninsula and Middle East gulf regions, during pre-monsoon season.