PERFECT RECALL AND PRUNING IN GAMES WITH IMPERFECT INFORMATION 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72986/1/j.1467-8640.1996.tb00256.x.pd

Evaluation of silica monoliths in affinity microcolumns for high-throughput analysis of drug–protein interactions

Silica monoliths in affinity microcolumns were tested for the high-throughput analysis of drug–protein interactions. HSA was used as a model protein for this work, while carbamazepine and R-warfarin were used as model analytes. A comparison of HSA silica monoliths of various lengths indicated columns as short as 1 to 3 mm could be used to provide reproducible estimates of retention factors or plate heights. Benefits of using smaller columns for this work included the lower retention times and lower back pressures that could be obtained versus traditional HPLC affinity columns, as well as the smaller amount of protein that is required for column preparation. One disadvantage of decreasing column length was the lower precision that resulted in retention factor and plate height measurements. A comparison was also made between microcolumns containing silica particles versus silica monoliths. It was demonstrated with R-warfarin that supports could be used in HSA microcolumns for the determination of retention factors or plate heights. However, the higher efficiency of the silica monolith made this the preferred support for work at higher flow rates or when a larger number of plates are needed during the rapid analysis of drug–protein interactions

The Neuro-Glial Properties of Adipose-Derived Adult Stromal (ADAS) Cells Are Not Regulated by Notch 1 and Are Not Derived from Neural Crest Lineage

We investigated whether adipose-derived adult stromal (ADAS) are of neural crest origin and the extent to which Notch 1 regulates their growth and differentiation. Mouse ADAS cells cultured in media formulated for neural stem cells (NSC) displayed limited capacity for self-renewal, clonogenicity, and neurosphere formation compared to NSC from the subventricular zone in the hippocampus. Although ADAS cells expressed Nestin, GFAP, NSE and Tuj1 in vitro, exposure to NSC differentiation supplements did not induce mature neuronal marker expression. In contrast, in mesenchymal stem cell (MSC) media, ADAS cells retained their ability to proliferate and differentiate beyond 20 passages and expressed high levels of Nestin. In neuritizing cocktails, ADAS cells extended processes, downregulated Nestin expression, and displayed depolarization-induced Ca2+ transients but no spontaneous or evoked neural network activity on Multi-Electrode Arrays. Deletion of Notch 1 in ADAS cell cultures grown in NSC proliferation medium did not significantly alter their proliferative potential in vitro or the differentiation-induced downregulation of Nestin. Co-culture of ADAS cells with fibroblasts that stably expressed the Notch ligand Jagged 1 or overexpression of the Notch intracellular domain (NICD) did not alter ADAS cell growth, morphology, or cellular marker expression. ADAS cells did not display robust expression of neural crest transcription factors or genes (Sox, CRABP2, and TH); and lineage tracing analyses using Wnt1–Cre;Rosa26R-lacZ or -EYFP reporter mice confirmed that fewer than 2% of the ADAS cell population derived from a Wnt1-positive population during development. In summary, although media formulations optimized for MSCs or NSCs enable expansion of mouse ADAS cells in vitro, we find no evidence that these cells are of neural crest origin, that they can undergo robust terminal differentiation into functionally mature neurons, and that Notch 1 is likely to be a key regulator of their cellular and molecular characteristics

Studies of immobilized antibody supports and their use in chromatographic immunoassays

A method of preparing dihydrazide-activated silica was developed for use in high-performance affinity chromatography (HPAC). This support was made by oxidizing diol-bonded silica and reacting it with oxalic or adipic dihydrazide. The steps involved in this synthesis were studied and confirmed by FTIR. Items considered in optimizing the preparation of the support included the amount of dihydrazide added and the reaction time or pH used. Control of dihydrazide bifunctional attachment was obtained by varying the extent of diol-bonded silica oxidation. This support was successfully used in the immobilization of oxidized antibodies, horse radish peroxidase and transfer RNA. The activity of the immobilized antibodies on dihydrazide activated silica were compared to those attached to silica by the Schiff base and CDI methods. The dihydrazide method produced antibodies with an activity that was equivalent to or greater than that produced by the amine-based coupling methods. This dihydrazide activated support was used in the immobilization of anti-HSA antibodies in the development of an automated immunoassay system for the simultaneous analysis of albumin and creatinine in urine. Albumin was determined by injecting samples onto a column containing immobilized anti-albumin antibodies. A flow injection analysis (FIA) system following this column was used to quantitate creatinine eluting in the non-retained peak. Items considered in the optimization of this system included the binding and elution properties of the immobilized antibody column and the reagent concentrations used in the FIA system. The total analysis time of the final method was five minutes per 20 $\mu$l injection. The limits of detection for albumin and creatinine were 0.005 and 0.008 mg/ml and the linear ranges covered a 200 to 1000-fold range in concentration. The within-run precision for both analytes was $\pm$2% or better and the results showed good agreement with those obtained by reference methods. The approach described is a general one that can be applied to other analytes in urine by using different immobilized antibody columns

Work environment study and exposure measurement on a shooting range (FOI, Grindsjön)

Bakgrund: Totalförsvarets forskningsinstituts skjutbana i Grindsjön är en provanläggning där storskaliga försök kan utföras för analys och metodutveckling av militära vapensystem. Olika typer av material som kan röra sig om fordonsskydd eller personskydd testas. Arbetsplatsen undersöktes av Previa, augusti 2011 och flera problemområden identifierades. Ventilationen i skjutbyggnaden hade brister och misstanke fanns om exponering för damm och partiklar samt tungmetaller på skjutbanan. Syfte: Syftet med studien var att utföra mätning av exponering för damm samt tungmetaller på FOI:s skjutbana, där ventilationsundersökning och emissionsmätning gjordes för att förtydliga exponeringsbilden. Koncentrationer av identifierade potentiellt hälsofarliga ämnen jämfördes med hygieniska gränsvärden varefter åtgärdsförslag presenterades. Metod: Studien utfördes med hjälp av observationer, intervju och mätningar. Mätningar avsåg exponering i form av emissionsmätning samt mätning av bakgrundshalt. Dessutom undersöktes ventilationen, genom mätning av lufthastigheten samt undersökning av luftrörelser. Temperaturen noterades i samband med mätningen. Mätresultatet analyserades och jämfördes med hygieniska gränsvärden. Slutsats: Blyhalter låg över de hygieniska gränsvärdena för båda arbetstagarna samt vid källan. Andra uppmätta halterna av både respirabla och totala dammpartiklar samt dess metallsammansättning översteg generellt inte de uppsatta hygieniska gränsvärdena. De högsta uppmätta halterna av damm och metaller var som förväntad vid emissionskällan. Efter undersökningen av ventilation och mätning av lufthastigheten konstaterades det att den var otillfredsställande med brister i uppbyggnad samt funktion. Utifrån arbetets art borde den byggas om så att arbetstagarna inte utsätts för farliga ämnen. Den dåliga städningen bidrar dessutom till en icke godtagbar arbetsmiljö