Songbird response to increased willow (Salix spp.) growth in Yellowstone's northern range

After nearly a century of height suppression, willows (Salix spp.) in the northern range of Yellowstone National Park, U.S.A., are increasing in height growth as a possible consequence of wolf (Canis lupus) restoration, climate change, or other factors. Regardless of the drivers, the recent release of this rare but important habitat type could have significant implications for associated songbirds that are exhibiting declines in the region. Our objective was to evaluate bird response to releasing willows by comparing willow structure and bird community composition across three willow growth conditions: height suppressed, recently released, and previously tall (i.e., tall prior to the height increase of released willows). Released and previously tall willows exhibited high and similar vertical structure, but released willows were significantly lower in horizontal structure. Suppressed willows were significantly shorter and lower in horizontal cover than released or previously tall willows. Bird richness increased along a gradient from lowest in suppressed to highest in previously tall willows, but abundance and diversity were similar between released and previously tall willows, despite lower horizontal cover in the released condition. Common Yellowthroat (Geothlypis trichas) and Lincoln's Sparrow (Melospiza lincolnii) were found in all three growth conditions; however, Yellow Warbler (Dendroica petechia), Warbling Vireo (Vireo gilvus), Willow Flycatcher (Empidonax traillii), and Song Sparrow (Melospiza melodii) were present in released and previously tall willows only. Wilson's Warbler (Wilsonia pusilla) was found in previously tall willows only, appearing to specialize on tall, dense willows. The results of our a priori habitat models indicated that foliage height diversity was the primary driver of bird richness, abundance, and diversity. These results indicate that vertical structure was a more important driver of bird community variables than horizontal structure and that riparian and willow-dependent bird species have responded positively to increased willow growth in the region.     

Experimental measurements and numerical simulations of the transport and retention of nanocrystal CdSe/ZnS quantum dots in saturated porous media: effects of pH,organic ligand,and natural organic matter

Environmental Science and Pollution Research - The risks of environmental exposures of quantum dot (QD) nanoparticles are increasing, but these risks are difficult to assess because fundamental...     

Torque Production Using Hand Cranks in a Simulated Gear-Operated Valve Opening Task

Hand cranks are used in a variety of industries to actuate valves and in other gear-operated applications. In order to evaluate these types of operations and their compatibility with operator strength capabilities, a rotational dynamometer was used to measure torque production capability of operators using a hand crank at different heights and angles (with respect to the coronal plane). The tests were conducted for both clockwise and counterclockwise rotations using the dominant arm of each test participant. A total of 18 tests were completed by each of five male right-handed test participants. A 0° declination angle, counterclockwise operation, and both 40.65 cm and 60.96 cm heights were found to be associated with the greatest torque production capabilities.     

Torque Production Using Handwheels of Different Size During a Simulated Valve Operation Task

Opening and closing valves in industrial facilities often requires operators to use bars and wrenches as levers (cheaters) in order to overcome initial actuation forces. In order to determine more appropriate operational specifications, the maximum torque production capability was measured when 12 male participants used 4 different valve handwheels at 3 different heights and 2 different angles (in relationship to the coronal plane). The results indicate that the participants produced significantly greater torque when the largest of the 4 wheels (40.6 cm diameter) was used than when the medium (22.9 cm), small (20.3 cm), and handled (17.8 cm) handwheels were used. Although the main effect of heights was found to be statistically significant, post-hoc analyses between the heights found them to be, essentially, equal. In addition, the vertical and horizontal wheel orientations were not found to be different. The results are applicable to all industries where handwheels are used and applicable to valve manufacturers for designing operational torque specifications below the values found in this study.     

Advancing Sustainable Bioenergy: Evolving Stakeholder Interests and the Relevance of Research

The sustainability of future bioenergy production rests on more than continual improvements in its environmental, economic, and social impacts. The emergence of new biomass feedstocks, an expanding array of conversion pathways, and expected increases in overall bioenergy production are connecting diverse technical, social, and policy communities. These stakeholder groups have different—and potentially conflicting—values and cultures, and therefore different goals and decision making processes. Our aim is to discuss the implications of this diversity for bioenergy researchers. The paper begins with a discussion of bioenergy stakeholder groups and their varied interests, and illustrates how this diversity complicates efforts to define and promote “sustainable” bioenergy production. We then discuss what this diversity means for research practice. Researchers, we note, should be aware of stakeholder values, information needs, and the factors affecting stakeholder decision making if the knowledge they generate is to reach its widest potential use. We point out how stakeholder participation in research can increase the relevance of its products, and argue that stakeholder values should inform research questions and the choice of analytical assumptions. Finally, we make the case that additional natural science and technical research alone will not advance sustainable bioenergy production, and that important research gaps relate to understanding stakeholder decision making and the need, from a broader social science perspective, to develop processes to identify and accommodate different value systems. While sustainability requires more than improved scientific and technical understanding, the need to understand stakeholder values and manage diversity presents important research opportunities.     

Removal of PFOS, PFOA and other perfluoroalkyl acids at water reclamation plants in South East Queensland Australia

This paper examines the fate of perfluorinated sulfonates (PFSAs) and carboxylic acids (PFCAs) in two water reclamation plants in Australia. Both facilities take treated water directly from WWTPs and treat it further to produce high quality recycled water. The first plant utilizes adsorption and filtration methods alongside ozonation, whilst the second uses membrane processes and advanced oxidation to produce purified recycled water. At both facilities perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) were the most frequently detected PFCs. Concentrations of PFOS and PFOA in influent (WWTP effluent) ranged up to 3.7 and 16 ng L⁻¹ respectively, and were reduced to 0.7 and 12 ng L⁻¹ in the finished water of the ozonation plant. Throughout this facility, concentrations of most of the detected perfluoroalkyl compounds (PFCs) remained relatively unchanged with each successive treatment step. PFOS was an exception to this, with some removal following coagulation and dissolved air flotation/sand filtration (DAFF). At the second plant, influent concentrations of PFOS and PFOA ranged up to 39 and 29 ng L⁻¹. All PFCs present were removed from the finished water by reverse osmosis (RO) to concentrations below detection and reporting limits (0.4-1.5 ng L⁻¹). At both plants the observed concentrations were in the low parts per trillion range, well below provisional health based drinking water guidelines suggested for PFOS and PFOA.     

Human disturbance and shifts in vertebrate community composition in a biodiversity hotspot

Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability. Areas with the most stringent land-use protections (e.g., Corcovado National Park, 24 species [95% CI 23–25]) harbored significantly more species than unprotected areas (20 species [19.7–20.3]), mainly due to a reduced presence of large-bodied species of conservation concern in unprotected areas (e.g., jaguar Panthera onca and white-lipped peccary Tayassu pecari). Small-bodied generalist species, such as opossums (Didelphidae) and armadillos (Dasypus novemcinctus), in contrast, were more common at disturbed sites, resulting in a significant difference in vertebrate community composition between sites with low and high disturbance. Co-occurrence of species was also mainly associated with response to disturbance. Similar responses to disturbance create two groups of species, those whose site-level occupancy usually increased as anthropogenic disturbance increased and those whose estimated occupancy decreased. The absence of large-bodied species entails an important loss of ecological function in disturbed areas and can hinder forest development and maintenance. Efforts to protect and restore forested landscapes are likely having a positive effect on the abundance of some threatened species. These efforts, however, must be sustained and expanded to increase connectivity and ensure the long-term viability of the wildlife community.     

Numerical modelling of nitrate transport in fractured porous media under non-isothermal conditions

Environmental Science and Pollution Research - Subsurface contamination is a frequent occurrence in fractured porous systems, posing a potential threat for the groundwater contamination. Tracking...     

Review on phase change materials for solar energy storage applications

Environmental Science and Pollution Research - The energy storage application plays a vital role in the utilization of the solar energy technologies. There are various types of the energy storage...