Modeling potential vadose-zone transport of nitrogen from onsite wastewater systems at the development scale.

Water in the urban front-range corridor of Colorado has become an increasingly critical resource as the state faces both supply issues as well as anthropogenic degradation of water quality in several aquifers used for drinking water. A proposed development (up to 1100 homes over two quarter-quarter sections) at Todd Creek, Colorado, a suburb of Westminster located about 20 miles northeast of Denver, is considering use of onsite wastewater systems (OWS) to treat and remove domestic wastewater. Local health and environmental agencies have concerns for potential impacts to local water quality. Nitrogen treatment in the vadose zone and subsequent transport to ground water at a development scale is the focus of this investigation. The numerical model HYDRUS 1D was used, with input based on site-specific data and several transport parameters estimated from statistical distribution, to simulate nitrate concentrations reaching ground water. The model predictions were highly sensitive to mass-loading of nitrogen from OWS and the denitrification rate coefficient. The mass loading is relatively certain for the large number of proposed OWS. However, reasonable values for the denitrification rate coefficients vary over three orders of magnitude. Using the median value from a cumulative frequency distribution function, based on rates obtained from the literature, resulted in simulated output nitrate concentrations that were less than 1% of regulatory maximum concentrations. Reasonable rates at the lower end of the reported range, corresponding to lower 95% confidence interval estimates, result in simulated nitrate concentrations reaching groundwater above regulatory limits.

Alternate forms reliability of the assessment of motor and process skills.

The purpose of this study is to examine the alternate forms reliability of the AMPS (Assessment of Motor and Process Skills) (Fisher, 1997a) where alternate forms means different pairs of AMPS tasks. The participants for this study were persons selected from the AMPS database who had performed four AMPS tasks. The participants varied in age, gender, diagnosis, and level of assistance needed to live in the community. The AMPS was administered by trained and calibrated occupational therapists according to standardized procedures. The data for the 91 participants were subjected to 12 many-faceted Rasch analyses to generate ADL motor and ADL process ability measures for each task and each set of paired tasks. Repeated measures ANOVAs revealed no time effect across the four AMPS tasks. Pearson product moment correlations between Tasks 1 and 2 combined and Tasks 3 and 4 combined were r = .91 and r = .86 for the ADL motor and ADL process scales, respectively. Calculation of the standardized difference (z) revealed that no more than 8% of the participants had ADL motor or ADL process ability measures that differed significantly between observations once we accounted for real differences in a persons performance; 80% of the paired ADL motor and ADL process ability measures remained stable within +/- 0.5 logits when the participants performed two tasks. The AMPS ADL motor and ADL process scales can be used reliably in clinical practice and for research purposes.

A low-incidence red cell antigen JAL associated with two unusual Rh gene complexes.

A multilaboratory investigation during several years has identified a low incidence antigen JAL on the red cells of 7 propositi. JAL appears to be associated with two unusual Rh complexes, one of which produces a depressed C antigen and the other a depressed c antigen. Family studies strongly suggest that the JAL antigen is encoded by the RH locus. Anti-JAL has been implicated in haemolytic disease of the newborn and is thus considered to be a clinically significant antibody.

The Lui elution technique. A simple and efficient method for eluting ABO antibodies.

The Lui elution and the heat elution techniques are the most simple techniques available for eluting antibodies from red cells. Both are very effective for eluting ABO antibodies. We compared the two techniques and found the Lui technique superior in that it more efficiently eluted ABO antibodies, required less hands-on time, and allowed more flexibility in the procedure. We therefore recommend the Lui elution technique as the method of choice for eluting ABO antibodies, especially for the evaluation of hemolytic disease of the newborn.