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31.
Christina M. Rudin-Brown Michael G. LennéJessica Edquist Jordan Navarro 《Accident; analysis and prevention》2012
Although collisions at level crossings are relatively uncommon occurrences, the potential severity of their consequences make them a top priority among safety authorities. Twenty-five fully-licensed drivers aged between 20 and 50 years participated in a driving simulator study that compared the efficacy, and drivers’ subjective perception, of two active level crossing traffic control devices: flashing lights with boom barriers and standard traffic lights. Because of its common usage in most states in Australia, a stop sign-controlled level crossing served as the passive referent. Although crossing violations were less likely at the level crossings controlled by active devices than at those controlled by stop signs, both kinds of active control were associated with a similar number of violations. Further, the majority (72%) of drivers reported preferring flashing lights to traffic lights. Collectively, results indicate that the installation of traffic lights at real-world level crossings would not be likely to offer safety benefits over and above those provided already by flashing lights with boom barriers. Furthermore, the high rate of violations at passively controlled crossings strongly supports the continued practice of upgrading level crossings with active traffic control devices. 相似文献
32.
Jessica Jones Schonna Manning Morela Montoya Karin Keller Martin Poenie 《Journal of the American Oil Chemists' Society》2012,89(8):1371-1381
Algae are a promising source of biofuel but claims about their lipid content can be ambiguous because extraction methods vary and lipid quantitation often does not distinguish between particular lipid classes. Here we compared methods for the extraction of algal lipids and showed that 2-ethoxyethanol (2-EE) provides superior lipid recovery (>150–200 %) compared to other common extraction solvents such as chloroform:methanol or hexane. Extractions of wet and dry algal biomass showed that 2-EE was more effective at extracting lipids from wet rather than dried algal pellets. To analyze lipid content we used normal-phase HPLC with parallel quantitation by an evaporative light scattering detector and a mass spectrometer. Analysis of crude lipid extracts showed that all major lipid classes could be identified and quantified and revealed a surprisingly large amount of saturated hydrocarbons (HC). This HC fraction was isolated from extracts of bioreactor-grown algae and further analyzed by HPLC/MS, NMR, and GC/MS. The results showed that the sample consisted of a mixture of saturated, straight- and branched-chain HC of different chain lengths. These algal HC could represent an alternative biofuel to triacylglycerols (TAG) that could feed directly into the current petroleum infrastructure. 相似文献
33.
Katia Rodríguez Kong Ah‐Hen Antonio Vega‐Gálvez Jessica López Issis Quispe‐Fuentes Roberto Lemus‐Mondaca Lena Gálvez‐Ranilla 《International Journal of Food Science & Technology》2014,49(4):990-1000
Murta (Ugni molinae T.) berries were air‐dried at five temperatures (40, 50, 60, 70 and 80 °C), and the changes in β‐carotene, phenolic acids, total phenolic and flavonoid contents and antioxidant capacities (DPPH and ORAC) were investigated. The berries showed a high content of β‐carotene, which decreased during drying temperature between 40 °C and 80 °C. Free and bound phenolic acids were also determined, showing gallic acid to be the prevalent phenolic acid. Total phenolic and flavonoid contents in the dried berries showed a higher decrease at lower temperature due to longer drying time. The radical‐scavenging activity also showed higher antioxidant activity at higher drying temperatures (70–80 °C) than at lower drying temperatures (40–50 °C). Total phenolic content (TPC) and flavonoids showed good correlation with antioxidant capacity. Murta berries proved to be an excellent source of antioxidants and bioactive compounds and are therefore a potential ingredient for new functional food products. 相似文献
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Little is known about how people structure sets of visualizations to support sequential viewing. We contribute findings from several studies examining visualization sequencing and reception. In our first study, people made decisions between various possible structures as they ordered a set of related visualizations (consisting of either bar charts or thematic maps) into what they considered the clearest sequence for showing the data. We find that most people structure visualization sequences hierarchically: they create high level groupings based on shared data properties like time period, measure, level of aggregation, and spatial region, then order the views within these groupings. We also observe a tendency for certain types of similarities between views, like a common spatial region or aggregation level, to be seen as more appropriate categories for organizing views in a sequence than others, like a common time period or measure. In a second study, we find that viewers’ perceptions of the quality and intention of different sequences are largely consistent with the perceptions of the users who created them. The understanding of sequence preferences and perceptions that emerges from our studies has implications for the development of visualization authoring tools and sequence recommendations for guided analysis. 相似文献
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Emily B. Button Andrew S. Mitchell Marcia M. Domingos Jessica H.-J. Chung Ryan M. Bradley Ashkan Hashemi Phillip M. Marvyn Ashley C. Patterson Ken D. Stark Joe Quadrilatero Robin E. Duncan 《Lipids》2014,49(4):305-316
Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation. 相似文献
38.
Palomares-Pecho Jessica M. Silva-Calpa Greis Francy M. Raposo Alberto B. 《Universal Access in the Information Society》2021,20(2):299-319
Universal Access in the Information Society - Studies on end-user adaptable applications for rehabilitation aim to offer exercises to patients based on their therapeutic goals and individual... 相似文献
39.
Scientific meetings and conferences are a part of the scientific process, and can facilitate collaboration, idea-sharing, and harmonization of research and management. The success of a conference can be measured using many criteria, including consistency and reoccurrence of the meetings, credibility by participation of reputable professionals, and attendance by a diverse community. In the interest of increasing the success of large-lake, freshwater science, policy, and management, this comment focuses on two recent conferences attended by the authors: the 60th annual meeting of the International Association for Great Lakes Research, in Detroit, U.S.A., and the African Great Lakes Conference, in Entebbe, Uganda. By our measures of success, we suggest that to make a larger impact on research, policy, and management of global, large, freshwater lakes that each conference can improve, either through greater diversity of experts from the global freshwater research community, or by consistently reoccurring on a regular basis. 相似文献
40.
Michael E. Sierszen Lee S. Schoen Jessica M. Kosiara Joel C. Hoffman Matthew J. Cooper Donald G. Uzarski 《Journal of Great Lakes research》2019,45(1):129-137
Hydrologic linkages among coastal wetland and nearshore areas allow coastal fish to move among the habitats, which has led to a variety of habitat use patterns. We determined nutritional support of coastal fishes from 12 wetland-nearshore habitat pairs using stable isotope analyses, which revealed differences among species and systems in multi-habitat use. Substantial (proportions?>?0.30) nutrition often came from the habitat other than that in which fish were captured. Nearshore subsidies to coastal wetlands indicate wetlands are not exclusively exporters of energy and materials; rather, there is reciprocity in the mutual energetic support of nearshore and wetland food webs. Coastal wetland hydrogeomorphology influenced the amount of multi-habitat use by coastal fishes. Fishes from systems with relatively open interfaces between wetland and nearshore habitats exhibited less nutritional reliance on the habitat in which they were captured, and higher use of resources from the adjacent habitat. Comparisons of stable isotope analyses of nutrition with otolith analyses of occupancy indicated nutritional sources often corresponded with habitat occupancy; however, disparities among place of capture, otolith analyses, and nutritional analyses indicated differences in the types of support those analyses inform. Disparities between occupancy information and nutritional information can stem from movements for support functions other than foraging. Together, occupancy information from otolith microchemistry and nutritional information from stable isotope analyses provide complementary measures of the use of multiple habitats by mobile consumers. This work underscores the importance of protecting or restoring a diversity of coastal habitats and the hydrologic linkages among them. 相似文献