Stream Fishes Estimate Water Quality in Dayton-Montgomery County Park District Reserves

Author Institution: Department of Zoology, Miami University-MiddletownInformation on fish communities within seven streams and rivers in or near Dayton-Montgomery County Park District reserves was collected and analyzed to compile a preliminary species list for Park District waters and to estimate water quality of the streams. Fifty-two species of fishes were found in lotic habitats in or near the reserves, and more extensive sampling likely will reveal the presence of additional species. Index of Biotic Integrity (IBI) scoring of the fish communities indicated that water quality within the reserves ranged from fair to exceptional. It would appear that improvements of water quality and fish communities within the reserves may require changes in wastewater treatment outfalls and stream drainage land-use practices

Unscreened water-diversion pipes pose an entrainment risk to the threatened green sturgeon, Acipenser medirostris.

Over 3,300 unscreened agricultural water diversion pipes line the levees and riverbanks of the Sacramento River (California) watershed, where the threatened Southern Distinct Population Segment of green sturgeon, Acipenser medirostris, spawn. The number of sturgeon drawn into (entrained) and killed by these pipes is greatly unknown. We examined avoidance behaviors and entrainment susceptibility of juvenile green sturgeon (35±0.6 cm mean fork length) to entrainment in a large (>500-kl) outdoor flume with a 0.46-m-diameter water-diversion pipe. Fish entrainment was generally high (range: 26-61%), likely due to a lack of avoidance behavior prior to entering inescapable inflow conditions. We estimated that up to 52% of green sturgeon could be entrained after passing within 1.5 m of an active water-diversion pipe three times. These data suggest that green sturgeon are vulnerable to unscreened water-diversion pipes, and that additional research is needed to determine the potential impacts of entrainment mortality on declining sturgeon populations. Data under various hydraulic conditions also suggest that entrainment-related mortality could be decreased by extracting water at lower diversion rates over longer periods of time, balancing agricultural needs with green sturgeon conservation

The Value of Literacy Practices

The concepts of literacy events and practices have received considerable attention in educational research and policy. In comparison, the question of value, that is, ‘which literacy practices do people most value?’ has been neglected. With the current trend of cross-cultural adult literacy assessment, it is increasingly important to recognise locally valued literacy practices. In this paper we argue that measuring preferences and weighting of literacy practices provides an empirical and democratic basis for decisions in literacy assessment and curriculum development and could inform rapid educational adaptation to changes in the literacy environment. The paper examines the methodological basis for investigating literacy values and its potential to inform cross-cultural literacy assessments. The argument is illustrated with primary data from Mozambique. The correlation between individual values and respondents’ socio-economic and demographic characteristics is explored

Photoionization from the Xe 4d orbitals of XeF2

We present a comparison of the photoionization dynamics of the 4d shell of XeF2 from threshold to 250 eV to those of the prototypical 4d shell of atomic Xe. The new experimental data include spin–orbit and ligand-field-resolved partial cross sections, photoelectron angular distributions, branching fractions, and lifetime widths for the 4d-hole states. The spin–orbit branching fractions and angular distributions are remarkably similar to the corresponding distributions from atomic Xe across a broad energy interval that includes both the intense shape resonance in the f continuum and a Cooper minimum in the same channel. The angular distributions and branching fractions are also in reasonably good agreement with our first-principles theoretical calculations on XeF2. Data are also presented on the lifetime widths of the substate-resolved 4d-hole states of XeF2. While the trends in the widths are similar to those in the earlier experimental and theoretical work, the linewidths are considerably smaller than in the previous measurements, which may require some reinterpretation of the decay mechanism. Finally, we present new data and an analysis of the Auger electron spectra for ionization above the 4d thresholds and resonant Auger spectra for several pre-edge features

Hydraulics Near Unscreened Diversion Pipes in Open Channels: Large Flume Experiments

Most of the water diversions on the Sacramento and San Joaquin Rivers (California, United States) and their tributaries are currently unscreened. These unscreened diversions are commonly used for irrigation and are potentially harmful to migrating and resident fishes. A large flume (test section: 18.29 m long, 3.05 m wide and 3.20 m high) was used to investigate the hydraulic fields near an unscreened water diversion under ecologically and hydraulically relevant diversion rates and channel flow characteristics. We investigated all combinations of three diversion rates (0.28, 0.42, and 0.57 m3/s) and three sweeping velocities (0.15, 0.38, and 0.61 m/s), with one additional test at 0.71 m3/s and 0.15 m/s. We measured the three-dimensional velocity field at seven cross sections near a diversion pipe and constructed regression equations of the observed maximum velocities near the pipe. Because the velocity components in three directions (longitudinal, transverse, and vertical) were significantly greater near the diversion pipe inlet compared with those farther from it, they cannot be neglected in the modeling and design of fish guidance and protection devices for diversion pipes. Our results should be of great value in quantifying the hydraulic fields that are formed around fish guidance devices to design more effective protection for fishes from entrainment into unscreened water-diversion pipes