Survey of fishes and water properties of south San Francisco Bay, California, 1973-82

The objective of this study was to describe the physical and ichthyological changes occurring seasonally and annually in the south San Francisco Bay, based on the results of 2,561 otter trawl and water samples obtained between February 1973 and June 1982. Temperature varied predictably among seasons in a pattern that varied little between years. Salinity also underwent predictable seasonal changes but the pattern varied substantially between years. The most abundant species of fish were northern anchovy (Engraulis mordax), English sole (Parophrys vetulus), and shiner surfperch (Cymatogaster aggregata). The majority of the common fish species were most abundant during wet years and least abundant in dry years. Numeric diversity was highest during the spring and early summer, with no detectable interannual trends. Species composition changed extensively between seasons and between years, particularly years with extremely high or extremely low freshwater inflows. All the common species exhibited clustered spatial distributions. Such spatial clustering could affect the interpretation of data from estuarine sampling programs. Gobies (Family Gobiidae) were more abundant during flood tides than during ebb tides. English sole were significantly more abundant in shallower areas. Shiner surfperch showed significant differences in abundance between sample areas.(PDF file contains 28 pages.

Little green steps: sustainability practice for early years comes to WA.

Little Green Steps, a training workshop on education for sustainability for early years educators, was recently conducted by the Australian Association for Environmental Education - Western Australian Chapter (MEE-WAJ. With a grant from the Waste Authority of Western Australia, AAEE-WA was able to provide professional learning for staff of childcare services, kindergartens and preschools. The purpose of the training was to encourage sustainable practice through zero waste policy and practical implementation of these practices for children, staff and parents. This training was developed by Lady Gowrie Child Centre In Sydney and the Department of Environment, Climate Change and Water in New South Wales, and assisted in the setting up of the professional development component of Gosford City and Wyong Shire Councils' Little Green Steps Program. To increase national exposure to the program two days were offered in WA. Each day stood alone as a discrete training program

Transport properties of N2 gas at cryogenic temperatures

The viscosity and thermal conductivity of nitrogen gas for the temperature range 5 K - 135 K have been computed from the second Chapman-Enskog approximation. Quantum effects, which become appreciable at the lower temperatures, are included by utilizing collision integrals based on quantum theory. A Lennard-Jones (12-6) potential was assumed. The computations yield viscosities about 20 percent lower than those predicted for the high end of this temperature range by the method of corresponding states, but the agreement is excellent when the computed values are compared with existing experimental data

Origins of concentration dependence of waiting times for single-molecule fluorescence binding

Binary fluorescence time series obtained from single-molecule imaging experiments can be used to infer protein binding kinetics, in particular, association and dissociation rate constants from waiting time statistics of fluorescence intensity changes. In many cases, rate constants inferred from fluorescence time series exhibit nonintuitive dependence on ligand concentration. Here we examine several possible mechanistic and technical origins that may induce ligand dependence of rate constants. Using aggregated Markov models, we show under the condition of detailed balance that non-fluorescent bindings and missed events due to transient interactions, instead of conformation fluctuations, may underly the dependence of waiting times and thus apparent rate constants on ligand concentrations. In general, waiting times are rational functions of ligand concentration. The shape of concentration dependence is qualitatively affected by the number of binding sites in the single molecule and is quantitatively tuned by model parameters. We also show that ligand dependence can be caused by non-equilibrium conditions which result in violations of detailed balance and require an energy source. As to a different but significant mechanism, we examine the effect of ambient buffers that can substantially reduce the effective concentration of ligands that interact with the single molecules. To demonstrate the effects by these mechanisms, we applied our results to analyze the concentration dependence in a single-molecule experiment EGFR binding to fluorophore-labeled adaptor protein Grb2 by Morimatsu et al. (PNAS,104:18013,2007).Comment: 11 pages, 4 figures; J. Chem. Phys., 137, 201

Measuring and comparing the reliability of the structured walkthrough evaluation method with novices and experts

Effective evaluation of websites for accessibility remains problematic. Automated evaluation tools still require a significant manual element. There is also a significant expertise and evaluator effect. The Structured Walkthrough method is the translation of a manual, expert accessibility evaluation process adapted for use by novices. The method is embedded in the Accessibility Evaluation Assistant (AEA), a web accessibility knowledge management tool. Previous trials examined the pedagogical potential of the tool when incorporated into an undergraduate computing curriculum. The results of the evaluations carried out by novices yielded promising, consistent levels of validity and reliability. This paper presents the results of an empirical study that compares the reliability of accessibility evaluations produced by two groups (novices and experts). The main results of this study indicate that overall reliability of expert evaluations was 76% compared to 65% for evaluations produced by novices. The potential of the Structured Walkthrough method as a useful and viable tool for expert evaluators is also examined. Copyright 2014 ACM

Parametric oscillator tuning curve from observations of total parametric fluorescence

Measurements of total emitted parametric fluorescence power are presented and used to fix one point on the predicted tuning curve of a parametric oscillator. The method is particularly useful for predicting the tuning curve of infrared pumped parametric oscillators. Experimental results, which verify the usefulness of the technique in a 1.06-μ-pumped oscillator, are presented

Age, Growth, Life History, and Fisheries of the Sand Sole, Psettichthys melanostictus

Sand sole, Psettichthys melanostictus, is a small but important part of the west coast groundfish fishery. It has never been assessed and there is a limited amount of biological data for the species. We provide the first estimates of age and growth for California populations and compare them with studies from other areas. We found that sand sole is a rapidly growing species which may show a strong latitudinal gradient in growth rate. We also found evidence of a recent, strong cohortrelated shift in the sex ratio of the population towards fewer females. In addition we examined data from the Washington, Oregon, and California commercial fishery to make an initial determination of population status. We found that catch per unit of effort in commercial trawls experienced a decline over time but has rebounded in recent years, except central California (the southern part of its commercial range), where the decline has not reversed