Showing papers by "David L. Strayer published in 2000"
TL;DR: In this article, the authors used an 11-year record of DO in the tidal Hudson River to describe the timing and spatial extent of the DO decline as compared to the timing of the zebra mussel establishment in the river.
Abstract: Dissolved oxygen (DO) declines have serious implications for the health of aquatic systems. These declines are often attributed to changes in organic or nutrient loading but are not generally attributed to species invasions. We use an 11-year record of DO in the tidal Hudson River to describe the timing and spatial extent of the DO decline as compared to the timing and spatial extent of the zebra mussel establishment in the river. Furthermore, the system attributes that interact with zebra mussel respiration to moderate DO declines are explored using physical and biological budgets. Concurrent with the establishment of the zebra mussel, mean summertime DO declined from 8.3 to 7.3 mg L-1. Because of moderate hydrologic inputs and atmospheric exchange, system respiration would have to increase by only about 0.5 g of O2 m-2 d-1 to have caused this decline. Independently estimated zebra mussel respiration (1.1 g of O2 m-2 d-1) is about double this required respiration. Increased macrophyte photosynthesis, due...
82 citations
TL;DR: The findings are most consistent with the attention-based interpretation of novel popout, which suggests that attention is rapidly drawn to the novel object in an otherwise familiar display.
Abstract: When observers are given a brief glimpse of a display containing one novel object and three repeated objects, they are often better able to report the location of the novel object than the location of any one of the repeated objects. The present study contrasted two interpretations of this “novel popout” effect. The attention-based interpretation suggests that the novel popout is an attentional phenomenon, occurring during the initial processing of the four-object display. The retrieval-based interpretation suggests that novel popout is due to differential processing occurring when observers are subsequently probed for the location of one of the objects in the display. ERP measures recorded while subjects performed the novel popout task revealed differences during the initial processing of the four-object display but not subsequent to the presentation of a localization probe. The findings are most consistent with the attention-based interpretation of novel popout, which suggests that attention is rapidly drawn to the novel object in an otherwise familiar display.
16 citations
TL;DR: This paper studied the macroinvertebrate fauna of a rocky shore in the freshwater tidal Hudson River during 1992-1994, the early years of the zebra mussel invasion.
Abstract: We studied the macroinvertebrate fauna of a rocky shore in the freshwater tidal Hudson River during 1992–1994, the early years of the zebra mussel (Dreissena polymorpha) invasion. The macroinvertebrate community was numerically dominated by chironomids, nematodes, oligochaetes, gastropods, zebra mussels, and planarian flatworms. The community was a mixture of species typical of stony warm water rivers and lake shores, freshwater generalists, and semiterrestrial species. Overall macroinvertebrate densities were moderate to low (2,800–14,600 m−2). Density was a strong function of season and elevation, with consistently low densities in the early spring and in the intertidal zone. This pattern suggests that physical harshness (alternating submergence and desiccation;ice and low temperatures) limits the distribution of invertebrates at this site. Zebra mussels occurred at our study site chiefly below the low tide mark, but only at moderate abundance (usually <1,000 m−2). A weak correlation between the densities of zebra mussels and those of other macroinvertebrates nonetheless suggests that the zebra mussel invasion may have affected community structure.
13 citations
01 Jan 2000
TL;DR: The research outcome, potential, and recently received NIH grant supporting the team’s scientific methods all point to the contributions that architecture may offer to the growing field of data visualization.
Abstract: The explosive growth of scientific visualization in the past 10 years demonstrate a consistent and tacit agreement among scientists that visualization offers a better representation system for displaying complex data than traditional charting methods. However, most visualization works have not been unable to exploit the full potential of visualization techniques. The reason may be that these attempts have been largely executed by scientists. While they have the technical skills for conducting research, they do not have the design background that would allow them to display data in easy to understand formats. This paper presents the architectural methodology, theory, technology and products that are being employed in an ongoing multidisciplinary data visualization research in anesthesiology. The project’s main goal is to develop a new data representation technology to visualize physiologic information in real time. Using physiologic data, 3-D objects are generated in digital space that represent physiologic changes within the body and show functional relationships that aid in the detection, diagnosis, and treatment of critical events. Preliminary testing results show statistically significant reduction in detection times. The research outcome, potential, and recently received NIH grant supporting the team’s scientific methods all point to the contributions that architecture may offer to the growing field of data visualization.
12 citations
01 Jan 2000
TL;DR: Density was a strong function of season and elevation, with consistently low densities in the early spring and in the intertidal zone, which suggests that physical harshness limits the distribution of invertebrates at this site.
Abstract: We studied the macroinvertebrate fauna of a rocky shore in the freshwater tidal Hudson River during 1992-1994, the early years of the zebra mussel (Dreissena polymorpha) invasion. The macroinvertebrate community was numerically dominated by chironomids, nematodes, oligochaetes, gastropods, zebra mussels, and planarian flatworms. The community was a mixture of species typical of stony warm water rivers and lake shores, freshwater generalists, and semiterrestrial species. Overall macroinvertebrate densities were moderate to low (2,800-14,600 m-2). Density was a strong function of season and elevation, with consistently low densities in the early spring and in the intertidal zone. This pattern suggests that physical harshness (alternating submergence and desiccation; ice and low temperatures) limits the distribution of invertebrates at this site. Zebra mussels occurred at our study site chiefly below the low tide mark, but only at moderate abundance (usually <1,000 m-2). A weak correlation between the densities of zebra mussels and those of other macroinvertebrates nonetheless suggests that the zebra mussel invasion may have affected community structure.
11 citations