Carbon exchange by establishing biofuel crops in Central Illinois

Perennial grass biofuels may contribute to long-term carbon sequestration in soils, thereby providing a broad range of environmental benefits. To quantify those benefits, the carbon balance was investigated over three perennial grass biofuel crops - miscanthus (Miscanthus × giganteus), switchgrass (Panicum virgatum) and a mixture of native prairie plants - and a row crop control (maize-maize-soy) in Central Illinois, USA, during the establishment phase of the perennial grasses (2008-2011). The eddy covariance technique was used to calculate fluxes of carbon dioxide and energy balance components, such as latent and sensible heat fluxes. Whereas maize attained the highest maximal carbon uptake rates, the perennial grasses had significantly extended growing seasons, such that their total carbon uptake rivaled that of corn in the second growing season and greatly exceeded that of soy in the third growing season. To account for the removal of carbon through harvest, net ecosystem exchange of carbon (NEE) was combined with estimates of yields, resulting in the net ecosystem carbon balance (NECB). After 2.5 years, NECB for the maize/soybean plot was positive (a source of carbon), while the grasses were a sink of carbon. Continuous measurements over the next years are required in order to confirm whether miscanthus, switchgrass and prairie can sustain a long-term sink of carbon if managed for biofuels, i.e., if harvested annually.     

Integrating Groundwater Conservation and Reuse into Remediation Projects

Groundwater remediation projects generally involve extraction and treatment of contaminated groundwater. The current state of the practice does not include an emphasis on conservation and reuse of groundwater. Consequently treated groundwater is typically disposed in sanitary or storm sewers. Longstanding water conservation and reuse practices in the municipal wastewater industry provide a body of experience available to the remediation industry. Case studies of conservation and reuse options for groundwater at remediation sites have been found across a broad range of geographic settings and regulatory jurisdictions. The intent of this article is to stimulate a more holistic view of the groundwater associated with remediation projects and to promote conservation and beneficial reuse of a vital natural resource. © 2014 US Sustainable Remediation Forum     

Exploring relationships between observed activation rates and functional attributes of lane departure prevention

Objective: Drivers’ use of lane departure warning and prevention systems is lower than use of other crash avoidance technologies and varies significantly by manufacturer. One factor that may affect use is how well a system prevents unintended departures. The current study evaluated the performance of systems that assist in preventing departures by providing steering or braking input in a 2016 Chevrolet Malibu, 2016 Ford Fusion, 2016 Honda Accord, and 2018 Volvo S90. These vehicles were selected because a prior observational study found that the percentage of privately owned vehicles that had lane departure prevention systems turned on varied among these 4 automakers.

Method: In each vehicle, a test driver induced 40 lane drifts on left and right curves by steering the vehicle straight into the curve so that vehicles departed in the opposite direction and 40 lane drifts on straightaways by slight steering input to direct the vehicle to left and right lane markers.

Results: Vehicles from automakers with higher observed lane departure prevention use rates (Volvo, Chevrolet) featured systems that provided steering input earlier and more often avoided crossing lane markers by more than 35?cm compared to vehicles from automakers with lower observed use rates (Ford, Honda).

Conclusion: The study identified functional characteristics (i.e., timing of steering input, prevention of departures more than 35?cm) of lane departure prevention systems that were strongly associated with observed activation of these systems in privately owned vehicles. Although this relationship does not imply causation, the findings support the hypothesis that functional characteristics of lane departure prevention systems affect their use. Designers may be able to use these results to maximize driver acceptance of future implementations of lane departure prevention.     

自然保护区、恢复力和动态景观

在这个日益被人类活动所改变的世界里,保护生物多样性对于维持有恢复力的生态系统和确保生态系统产品的可持续流动以及对社会的服务是至关重要的.但是,现有的自然保护区和国家公园不大可能结合生态系统的长期和大尺度的动态.因此,保护策略必须包括大面积的人类利用经营的土地.为了能使生态系统在大规模的自然和人为干扰之后得以重组,以生态存储形式出现的空间恢复力是必备的前提.生态存储包括那些能使生态系统得以重组的物种、相互作用和结构,它的组成部分可能出现在干扰斑块中,也可能出现在周围的景观中.现有的静态自然保护区应该由动态自然保护区加以补充,例如生态休闲地和动态演替保护区,这些都是在景观尺度上模拟自然干扰状况,进行生态系统经营的组成部分.     

Assessment of sperm competition by European bitterling,<Emphasis Type="Italic"> Rhodeus sericeus</Emphasis>

We investigated male assessment of sperm competition in the bitterling, Rhodeus sericeus, a freshwater fish that spawns on the gills of living unionid mussels. Field experiments showed males increased their inspection rate of mussels into which a testis solution containing sperm had been experimentally released. Males avoided leading females to mussels that contained high numbers of embryos, but did not alter their leading behavior in response to the presence of sperm. In laboratory experiments males also increased their inspection rate of mussels into which a testis solution had been released and also failed to alter their leading behavior in response to the presence of sperm in mussels. However, males avoided leading females to mussels in close proximity to other males, and thereby may avoid sperm competition. In a second field study, territorial males were shown to ejaculate into mussels at a low rate in the absence of competitors, increase the frequency of ejaculations in competition with a rival, then decrease relative ejaculate expenditure as the number of competing males increased. Observed data were shown to be significantly correlated with predicted estimates of ejaculate expenditure for a model of sperm competition intensity. We discuss our results in the context of adaptive responses of males to sperm competition.     

Reserves, resilience and dynamic landscapes

In a world increasingly modified by human activities, the conservation of biodiversity is essential as insurance to maintain resilient ecosystems and ensure a sustainable flow of ecosystem goods and services to society. However, existing reserves and national parks are unlikely to incorporate the long-term and large-scale dynamics of ecosystems. Hence, conservation strategies have to actively incorporate the large areas of land that are managed for human use. For ecosystems to reorganize after large-scale natural and human-induced disturbances, spatial resilience in the form of ecological memory is a prerequisite. The ecological memory is composed of the species, interactions and structures that make ecosystem reorganization possible, and its components may be found within disturbed patches as well in the surrounding landscape. Present static reserves should be complemented with dynamic reserves, such as ecological fallows and dynamic successional reserves, that are part of ecosystem management mimicking natural disturbance regimes at the landscape level.     

Evaluation of a low-cost transient mass measurement system in vehicle inspection and maintenance testing: results of a Gordon-Darby Study

A study was performed at a Gordon-Darby centralized inspection and maintenance (I/M) test lane in Phoenix, AZ, in December 1999 for the purpose of evaluating the accuracy of production Vehicle Mass Analysis System (VMAS) equipment relative to standard IM240 equipment. Simultaneous transient mass measurements were made on random vehicles using VMAS and IM240 systems on two test lanes during regular I/M testing. Cumulative mass emissions for 846 valid tests were correlated using least-squares regression analysis. Correlation indices were > 0.99 for both carbon monoxide (CO) and nitric oxide (NO) and 0.93 for hydrocarbon (HC), and the standard errors of regression were 1.38 g/mi, 0.123 g/mi, and 0.245 g/mi for CO, NO, and HC, respectively. These strong correlation results are reflected by high excess emission identification rates of 99.4% for CO, 99.3% for NO, and 94.5% for HC when applying final IM240 cut points with a < 2% error of commission for all pollutants.