ABSTRACT
In the new Dutch decision tree for the evaluation of pesticide leaching to groundwater, spatially distributed soil data are used by the GeoPEARL model to calculate the 90th percentile of the spatial cumulative distribution function of the leaching concentration in the area of potential usage (SP90). Until now it was not known to what extent uncertainties in soil and pesticide properties propagate to spatially aggregated parameters like the SP90. A study was performed to quantify the uncertainties in soil and pesticide properties and to analyze their contribution to the uncertainty in SP90. First, uncertainties in the soil and pesticide properties were quantified. Next, a regular grid sample of points covering the whole of the agricultural area in the Netherlands was randomly selected. At the grid nodes, realizations from the probability distributions of the uncertain inputs were generated and used as input to a Monte Carlo uncertainty propagation analysis. The analysis showed that the uncertainty concerning the SP90 is 10 times smaller than the uncertainty about the leaching concentration at individual point locations. The parameters that contribute most to the uncertainty about the SP90 are, however, the same as the parameters that contribute most to uncertainty about the leaching concentration at individual point locations (e.g., the transformation half-life in soil and the coefficient of sorption on organic matter). Taking uncertainties in soil and pesticide properties into account further leads to a systematic increase of the predicted SP90. The important implication for pesticide regulation is that the leaching concentration is systematically underestimated when these uncertainties are ignored.
Subject(s)
Models, Statistical , Pesticides/chemistry , Soil Pollutants/chemistry , Soil/chemistry , Uncertainty , Computer Simulation , Monte Carlo Method , Netherlands , Sensitivity and Specificity , Water Movements , Water Pollutants, Chemical/chemistryABSTRACT
BACKGROUND: Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a growth factor commonly used to avoid leukopenia after chemotherapy. Endogenous G-CSF is produced by macrophages and granulocytes that infiltrate tumors. It has been reported that rhG-CSF stimulates the proliferation of several cell lines as well as bladder carcinoma cells. Conversely, in some hematopoietic cell lines such as U-937, WEHI-3B, and K-562 no effect or in some cases a differentiation pattern was found. Moreover, the role of rhG-CSF on the proliferation of solid tumors is not well understood. METHODS: In this study, 10 ovarian carcinoma biopsies were characterized for the presence of G-CSF and G-CSF receptor by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Proliferation was analyzed by ATP viability assays. RESULTS: Performing RT-PCR, these biopsies and four ovarian carcinoma cell lines were analyzed for endogenous G-CSF production, which was found in some biopsies and in all cell lines. Despite the presence of the G-CSF receptor in all biopsies and cell lines, no proliferation was found after rhG-CSF incubation of the cell lines or the tumor samples for 3 and for 6 days, respectively. CONCLUSIONS: Summarizing the authors' in vitro studies, rhG-CSF does not affect the proliferation of ovarian carcinoma cells in vitro.
Subject(s)
Carcinoma/genetics , Carcinoma/pathology , Gene Expression , Granulocyte Colony-Stimulating Factor/physiology , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Receptors, Granulocyte Colony-Stimulating Factor/genetics , Adenosine Triphosphate/analysis , Biopsy , Blotting, Southern , Carcinoma/chemistry , Cell Division , Colony-Stimulating Factors/pharmacology , Female , Granulocyte Colony-Stimulating Factor/analysis , Humans , Immunohistochemistry , Ovarian Neoplasms/chemistry , Receptors, Granulocyte Colony-Stimulating Factor/analysis , Recombinant Proteins , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, CulturedABSTRACT
This study compares two clinical practice guideline dissemination systems. It was hypothesized that placing guidelines on an intranet would make this information easier to retrieve. Retrieval time, retrieval accuracy, and ease of use were empirically evaluated. Sixteen clinicians from Kaiser Permanente volunteered to complete tasks that measured these variables. Time values were significantly longer for tasks completed with intranet guidelines (Intranet = 6.7 minutes, Paper = 5.7 minutes). Tasks completed with paper guidelines had a significantly higher percentage of perfect scores than those completed with the intranet (Paper = 85%, Intranet = 59%). There was no significant difference in reported ease of use. Simply placing clinical information on an electronic system does not guarantee that the information will be easier to retrieve. Such information needs to be fully integrated into the clinical decision making process. Computerizing guidelines may provide a necessary initial step toward this goal, but it does not represent the final solution.
Subject(s)
Local Area Networks , Practice Guidelines as Topic , Task Performance and Analysis , Adult , Analysis of Variance , Computer Communication Networks , Evaluation Studies as Topic , Family Practice , Female , Health Maintenance Organizations , Humans , Internal Medicine , Male , Medical StaffABSTRACT
Dual coding theory (Paivio, 1986) suggests that communicating a stimulus person's age verbally/abstractly through words and numbers arouses little feeling and has little effect on the way others evaluate her or him, whereas communicating age nonverbally/concretely through facial photographs arouses more feeling and has a greater impact on evaluation. Two experiments reported in this article, involving U.S. students and incorporating techniques developed in prior research by Levin (1988) strongly support these theoretical expectations.
