Detection of a sebacate contaminant from chloroform

One of the major contaminants of reagent grade chloroform is identified as a diester of sebacic acid. The contaminant is not present in redistilled chloroform. Authorized for publication as Paper No. 3870 in the Journal Series of the Pennsylvania Agricultural Experiment Station.     

The Satchel system architecture: Mobile access to documents and services

Mobile professionals require access to documents and documentrelated services, such as printing, wherever they may be. They may also wish to give documents to colleagues electronically, as easily as with paper, facetoface, and with similar security characteristics. The Satchel system provides such capabilities in the form of a mobile browser, implemented on a device that professional people would be likely to carry anyway, such as a pager or mobile phone. Printing may be performed on any Satchelenabled printer, or any fax machine. Scanning, too, may be accomplished at any Satchelenabled scanner. Access rights to individual documents may be safely distributed, without regard to document formats. Access to document services is greatly simplified by the use of context sensitivity. The system has been extensively tested and evaluated. This paper describes the architecture of the Satchel system.     

Taking the national guideline for care of acute myocardial infarction to the bedside: developing the guideline applied in practice (GAP) initiative in Southeast Michigan.

BACKGROUND: The Guideline Applied in Practice (GAP) program was developed in 2000 to improve the quality of care by improving adherence to clinical practice guidelines. For the first GAP project, the American College of Cardiology (ACC) partnered with the Southeast Michigan Quality Forum Cardiovascular Subgroup and the Michigan Peer Review Organization (MPRO) to develop interventions that might facilitate the use of the ACC/AHA Acute Myocardial Infarction (AMI) guideline in the practice setting. Ten Michigan hospitals participated in implementing the project, which began in March 2000. DESIGNING THE PROJECT: The project developed a multifaceted intervention aimed at key players in the care delivery triangle: the physician, nurse, and patient. Intervention components included a project kick-off presentation and dinner, creation and implementation of a customized tool kit, identification and assignment of local nurse and physician opinion leaders, grand rounds site visits, and measurement before and after the intervention. IMPLEMENTING THE PROJECT: The GAP project experience suggests that hospitals are enthusiastic about partnering with ACC to improve quality of care; partners can work together to develop a program for guideline implementation; rapid-cycle implementation is possible with the GAP model; guidelines and quality indicators for AMI are well accepted; and hospitals can adapt the national guideline for care into usable tools focused on physicians, nurses, and patients. DISCUSSION: Important structure and process changes--both of which are required for successful QI efforts--have been demonstrated in this project. Ultimately, the failure or success of this initiative will depend on an indication that the demonstrated improvement in the quality indicators is sustained over time.     

Integrated offshore wind farm design: Optimizing micro‐siting and cable layout simultaneously

Electrical layout and turbine placement are key design decisions in offshore wind farm projects. Increased turbine spacing minimizes the energy losses caused by wake interactions between turbines but requires costlier cables with higher rates of failure. Simultaneous micro‐siting and electrical layout optimization are required to realize all possible savings. The problem is complex, because electrical layout optimization is a combinatorial problem and the computational fluid‐dynamics calculations to approximate wake effects are impossible to integrate into classical optimization. This means that state‐of‐the‐art methods do not generally consider simultaneous optimization and resort to approximations instead. We extend an existing model that successfully optimizes cable design to simultaneously consider micro‐siting. We use Jensen's equations to approximate the wake effect in an efficient manner, calibrating it with years of mast data. The wake effects are precalculated and introduced into the optimization problem. We solve simultaneously for turbine spacing and cable layout, exploiting the tradeoffs between these wind farm features. We use the Barrow Offshore Wind Farm as a case study to demonstrate realizable savings up to 6 MEUR over the lifetime of the plant, although it is possible that unforeseen design constraints have implications for whether the savings seen in our model are fully realizable in the real world. In addition, the model provides insights on the effects of turbine spacing that can be used to simplify the design process or to support negotiations for surface concession at the earlier stages of a project.     

Pseudomonas putida Biofilm Depends on the vWFa-Domain of LapA in Peptides-Containing Growth Medium

The biofilm of Pseudomonas putida is complexly regulated by several intercellular and extracellular factors. The cell surface adhesin LapA of this bacterium is a central factor for the biofilm and, consequently, the regulation of lapA expression, for example, by Fis. It has been recently shown that peptides in growth media enhance the formation of P. putida biofilm, but not as a source of carbon and nitrogen. Moreover, the peptide-dependent biofilm appeared especially clearly in the fis-overexpression strain, which also has increased LapA. Therefore, we investigate here whether there is a relationship between LapA and peptide-dependent biofilm. The P. putida strains with inducible lapA expression and LapA without the vWFa domain, which is described as a domain similar to von Willebrand factor domain A, were constructed. Thereafter, the biofilm of these strains was assessed in growth media containing extracellular peptides in the shape of tryptone and without it. We show that the vWFa domain in LapA is necessary for biofilm enhancement by the extracellular peptides in the growth medium. The importance of vWFa in LapA was particularly evident for the fis-overexpression strain F15. The absence of the vWFa domain diminished the positive effect of Fis on the F15 biofilm.     

Separation of underivatized gangliosides by ion exchange high performance liquid chromatography

A procedure is described which separates neutral glycolipids from gangliosides, and which separates the gangliosides into classes, based on their number of sialic acid residues. In addition to separation into mono-, di- and trisialoganglioside classes, there is purification of individual disialoganglioside species. The procedure uses a commercially available—NH₂ high performance liquid chromatography (HPLC) column, which normally is used as an adsorption column. In this method the column is modified by protonation, to pH 5.4, so that it exhibits ion exchange as well as adsorption properties. Sensitive, nondestructive detection of eluent peaks is accomplished by monitoring continuously at 210 nm, a wavelength near which underivatized glycosphingolipids have absorbance maxima and which also will clearly detect most possible contaminants. An entire run, including re-equilibration of the column, takes two hours.