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Quality Control Procedures (quality + control_procedure)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Three-dimensional spatial interpolation of surface meteorological observations from high-resolution local networks

METEOROLOGICAL APPLICATIONS, Issue 3 2008
Francesco Uboldi
Abstract An objective analysis technique is applied to a local, high-resolution meteorological observation network in the presence of complex topography. The choice of optimal interpolation (OI) makes it possible to implement a standard spatial interpolation algorithm efficiently. At the same time OI constitutes a basis to develop, in perspective, a full multivariate data assimilation scheme. In the absence of a background model field, a simple and effective de-trending procedure is implemented. Three-dimensional correlation functions are used to account for the orographic distribution of observing stations. Minimum-scale correlation parameters are estimated by means of the integral data influence (IDI) field. Hourly analysis fields of temperature and relative humidity are routinely produced at the Regional Weather Service of Lombardia. The analysis maps show significant informational content even in the presence of strong gradients and infrequent meteorological situations. Quantitative evaluation of the analysis fields is performed by systematically computing their cross validation (CV) scores and by estimating the analysis bias. Further developments concern the implementation of an automatic quality control procedure and the improvement of error covariance estimation. Copyright © 2008 Royal Meteorological Society [source]

Community psychiatric nurses' experience of working with people who engage in deliberate self-harm

INTERNATIONAL JOURNAL OF MENTAL HEALTH NURSING, Issue 3 2008
Andrew R. Thompson
ABSTRACT:, This paper reports on a study that explored community psychiatric nurses' experiences of working with people who self-harm. Interpretative Phenomenological Analysis was used with eight experienced community psychiatric nurses who participated in semi-structured interviews. Established quality control procedures were utilized including audit of the analysis process and validating the results with participants. The participants described struggling to conceptualize self-harm behaviour and generally reported finding working with people who self-harm stressful particularly in terms of managing the emotional impact upon themselves and the boundaries of their professional responsibilities in relation to managing risk. The therapeutic relationship was viewed as crucial and a variety of coping methods to manage the impact of the work, which had largely developed through ,on the job', experience were described. The results highlight the potential difficulties faced by community staff and can be translated into clear recommendations for training and support. [source]

PATHOGEN DETECTION IN FOOD MICROBIOLOGY LABORATORIES: AN ANALYSIS OF QUALITATIVE PROFICIENCY TEST DATA, 1999,2007

JOURNAL OF FOOD SAFETY, Issue 4 2009
DANIEL C. EDSON
ABSTRACT The objective of this study was to assess laboratories' ability to detect or rule out the presence of four common food pathogens: Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Campylobacter spp. To do this, qualitative proficiency test data provided by one proficiency test provider from 1999 to 2007 were examined. The annual and cumulative 9-year percentages of false-negative and false-positive responses were calculated. The cumulative 9-year false-negative rates were 7.8% for E. coli O157:H7, 5.9% for Salmonella spp., 7.2% for L. monocytogenes and 13.6% for Campylobacter spp. Atypical strains and low concentrations of bacteria were more likely to be missed, and the data showed no trend of improving performance over time. Percentages of false-positive results were below 5.0% for all four pathogens. PRACTICAL APPLICATIONS The results imply that food testing laboratories often fail to detect the presence of these four food pathogens in real food specimens. To improve pathogen detection, supervisors should ensure that testing personnel are adequately trained, that recommended procedures are followed correctly, that samples are properly prepared, that proper conditions (temperature, atmosphere and incubation time) are maintained for good bacterial growth and that recommended quality control procedures are followed. Supervisors should also always investigate reasons for unsatisfactory proficiency test results and take corrective action. Finally, more research is needed into testing practices and proficiency test performance in food testing laboratories. [source]

Development of a decision support system for diagnosis and grading of brain tumours using in vivo magnetic resonance single voxel spectra

NMR IN BIOMEDICINE, Issue 4 2006
Anne R. Tate
Abstract A computer-based decision support system to assist radiologists in diagnosing and grading brain tumours has been developed by the multi-centre INTERPRET project. Spectra from a database of 1H single-voxel spectra of different types of brain tumours, acquired in vivo from 334 patients at four different centres, are clustered according to their pathology, using automated pattern recognition techniques and the results are presented as a two-dimensional scatterplot using an intuitive graphical user interface (GUI). Formal quality control procedures were performed to standardize the performance of the instruments and check each spectrum, and teams of expert neuroradiologists, neurosurgeons, neurologists and neuropathologists clinically validated each case. The prototype decision support system (DSS) successfully classified 89% of the cases in an independent test set of 91 cases of the most frequent tumour types (meningiomas, low-grade gliomas and high-grade malignant tumours,glioblastomas and metastases). It also helps to resolve diagnostic difficulty in borderline cases. When the prototype was tested by radiologists and other clinicians it was favourably received. Results of the preliminary clinical analysis of the added value of using the DSS for brain tumour diagnosis with MRS showed a small but significant improvement over MRI used alone. In the comparison of individual pathologies, PNETs were significantly better diagnosed with the DSS than with MRI alone. Copyright © 2006 John Wiley & Sons, Ltd. [source]