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PubMed1990

[Analysis of doctoral theses in nursing science produced in Finland in the years 1982-1987].

Licentiate theses in nursing science produced in Finland in 1982-87 are analysed in terms of their frame of reference, methodology, data collection techniques and analytical methods. The data were gathered by means of a content analysis using a list of themes specially constructed for this purpose and classified qualitatively on the basis of statements appearing in the theses. The majority of the theses were of a descriptive nature, usually employing a survey method. The most common means of data collection was by questionnaire, typically combining a number of such methods within the same work. The material was largely analysed by quantitative methods, with a qualitative approach adopted in only two cases. The theoretical frame of reference consisted of the theories of nursing science and the behavioural sciences, but two theses were found which did not make use of information from nursing science at all in their frame of reference, and three which developed their own theoretical models.

Academic Dissertations as Topic↗
PubMed1994

Technical report. An inexpensive densitometric analysis system using a Macintosh computer and a desktop scanner.

A brief description of the setup of an inexpensive densitometric analysis system is provided. This system uses a software package and scanner that can be obtained for a total of less than $1000 and that can be operated by any Macintosh computer, including a MacPlus. In the event that a scanner is already available, the software itself can be obtained for approximately $399. Several comparisons are presented of data obtained with this system, data obtained by other analytical methods and data obtained with more expensive, dedicated densitometric systems. These comparisons demonstrate the usefulness and accuracy of this system.

Computers↗
PubMed1996

Reasons for proficiency testing failures in clinical chemistry and blood gas analysis: a College of American Pathologists Q-Probes study in 665 laboratories.

OBJECTIVE: To determine the reasons for proficiency testing (PT) failures from 41 chemistry and blood gas analytes using data collected to benchmark performance. DESIGN: Self-administered survey requesting number of challenges by analyte encompassing nine PT events. When the challenge resulted in a self-defined failure, further information was requested concerning the magnitude of the failure (as a standard deviation index) and categorization of the type of failure into six major groups (Methodologic, Technical, Clerical, Survey, Unexplained, or Other) and then into subgroups. PARTICIPANTS: Laboratories enrolled in the 1992 College of American Pathologists Q-Probes program. MAIN OUTCOME MEASURES: Rate of PT failures and reasons for failure. RESULTS: Proficiency testing data from 670,489 challenges performed in 665 laboratories revealed 9268 (1.4%) unacceptable results. Failure types were distributed as follows: Methodologic, 33.5%; Technical, 17.4%; Clerical, 11.1%; Survey, 7.8%; Unexplained, 25.7%; and Other, 7.4%. CONCLUSIONS: Individual analyte PT failure is a common event in the participating laboratories, but failures in successive or alternate events are rare. Analysis of the reasons for failed events indicates that most identified reasons occurred in either the Methodologic or Technical categories (50.9%). Analysis of the failure types suggested investigation pathways based on the magnitude of the failure that could reduce the 25.7% rate of unexplained failures.

Blood Gas Analysis↗
PubMed2001

Histidine as a dipolar eluent component in cation chromatography. II. Prediction of retention data for alkaline and alkaline-earth ions.

The utility of cation chromatography has been developed by the application of L-histidine as a multiprotic and dipolar (zwitterionic) eluent component. The method simplifies the cation analysis. The chromatographic characteristics of this system were studied in detail with a view to determining the selectivity and the mechanism by which the cations (Na+, K+, Mg2+, Ca2+) are retained. Complete separations were observed in the isocratic run over the eluent concentration range 3.0-6.0 mM at pH below 2.0. Sensitive detection was achieved using suppressed conductivity at the pH of isoelectric point of the histidine. Retention equations are derived for mono- and divalent cations eluted from ion-exchange separation column with multiple ionic eluents. The theory is based on the extension of ion-exchange equilibrium by protonation equilibria. The selectivity data for analyte and eluent species are deterrmined using the model from the experimental retention data by computer-assisted iterative calculations. The model was utilized to predict retention data. The results in three-dimensional retention surfaces together with species distribution graphs are presented.

Cations↗
PubMed2002

Short-scan SPECT imaging with non-uniform attenuation and 3D distance-dependent spatial resolution.

Image quality and quantitative accuracy in single-photon emission computed tomography (SPECT) can be degraded by, e.g., the effects of photon attenuation and finite spatial resolution. It is generally considered that adequate compensation for such effects on SPECT images requires data acquired over 2 pi. Recently, using the existing consistency condition on the data function, Noo and Wagner (2001 Inverse Problems 17 1357-72) have shown analytically that data acquired over only pi can be used to correct completely for the effect of uniform attenuation in SPECT. It remains unknown, however, whether data acquired only over pi in SPECT with non-uniform attenuation and/or 3D distance-dependent spatial resolution (DDSR) contain complete information for accurate image reconstruction. In this work, we develop a heuristic perspective, which is referred to as the potato peeler perspective to show conceptually that data in SPECT with non-uniform attenuation and/or 3D DDSR acquired over 2 pi contain redundant information and that such information can be used to reduce the scanning angle in SPECT. Specifically, we show heuristically that, in SPECT with only non-uniform attenuation, the scanning angle can be reduced from 2 pi to pi and that, in SPECT with both non-uniform attenuation and DDSR with a physically realistic form, the scanning angle can be reduced from 2 pi to pi in a practical sense. We conduct computer simulation studies, and the results from these studies corroborate the observations obtained based upon the heuristic potato peeler perspective.

Algorithms↗
PubMed2003

Influence of socioeconomic status on the effectiveness of bicycle helmet legislation for children: a prospective observational study.

OBJECTIVE: To evaluate the influence of average family income in a geographic area on the effectiveness of helmet legislation on observed helmet use by children (5-14 years). METHODS: The study was conducted in East York, a health district of Metropolitan Toronto, in collaboration with the East York Health Unit. In 1996, the total population was 107 822, 11 340 of which were children 5 to 14 years. Census data were used to group the 21 census tracts in East York into 7 geographically distinct areas. The boundaries of these areas are natural barriers to travel, such as expressways, ravines, railway tracks, and hydroelectric power lines. The areas were also ranked according to average family income (based on Statistics Canada data). For analytical purposes, areas were defined as low-, mid-, and high-income areas. Census data profiles of the areas have been previously described. For each consecutive year from 1990 to 1997 inclusive, direct observations of children riding bicycles in East York during the months of April through October were made. In 1995, observations were completed before the introduction of the law on October 1, 1995. Only children who were between 5 and 14 years of age and riding a 2-wheeled bicycle were included in the study. In total, 111 sites across all 7 areas were selected for observation. Observational sites included school yards of all elementary and middle schools (kindergarten to grade 8) and all parks in East York. In addition, 5 major intersections and 5 residential streets from each area were randomly selected. Observers were trained and used a standardized data collection form. A pilot study showed that the data collected by observers were reliable and valid. Observers remained at each site for 1 hour and collected data on helmet use and sex. Ethical approval for the study was obtained from the Hospital for Sick Children Research Ethics Board, the East York Board of Education, and the Metropolitan Separate School Board. The proportion of children who were wearing a bicycle helmet was estimated by year (1990-1997, inclusive), sex (male, female), location (school, park, major intersection, residential street), and income area (low, mid, high). For estimating the effect of legislation on helmet use, data from the year immediately after legislation (1996) were compared with data from the year preceding legislation (1995). The relative risk (RR) of helmet use (after vs before legislation) was calculated along with a 95% confidence interval (CI). Logistic regression analysis was used to adjust for potential confounding variables (sex and location). RESULTS: During the 8-year study period, 9768 observations were made (range: 914-1879 observations per year). The proportion of child cyclists who wore a bicycle helmet increased steadily during the first 4 years of the study period, from 4% in 1990 (34 of 914), to 16% in 1991 (303 of 1879), to 25% in 1992 (383 of 1563), and to 45% in 1993 (438 of 984). During 1994 (460 of 1083) and 1995 (568 of 1227), helmet use remained relatively stable at approximately 44%. Helmet use rose markedly in 1996 (the first year after helmet legislation was introduced) to 68% (818 of 1202) and remained stable at 66% (609 of 916) in 1997. Throughout the study period, girls were consistently more likely to wear helmets than were boys. In total, 47% (1420 of 3047) of girls wore helmets, compared with 33% (2193 of 6721) of boys (RR: 1.43; 95% CI: 1.36-1.50). In addition, children who were riding to school were more likely to use helmets, compared with children who were riding on residential streets, major intersections, and parks. Overall, 48% (1497 of 3129) of children who were riding to school wore bicycle helmets, compared with 32% (2116 of 6639) of children who were riding at other locations (RR: 1.50; 95% CI: 1.43-1.58). Children in the high-income areas were consistently more likely to wear helmets, compared with children in the mid- and low-income areas. Helmet legislation was associated with a significant increase in helmet use by children in East York. In 1995, 46% (ast York. In 1995, 46% (568 of 1227) of children wore bicycle helmets, compared with 68% (818 of 1202) of children in 1996 (RR: 1.47; 95% CI: 1.37-1.58). The effect of legislation, however, varied by income area. In low-income areas, helmet use increased by 28% after legislation, from 33% (213 of 646) in 1995 to 61% (442 of 721) in 1996 (RR: 1.86; 95% CI: 1.64-2.11). In mid-income areas, helmet use increased by 29% after legislation, from 50% (150 of 300) in 1995 to 79% (185 of 234) in 1996 (RR: 1.58; 95% CI: 1.39-1.80). In high-income areas, helmet use increased by only 4%, from 73% (205 of 281) in 1995 to 77% (191 of 247) in 1996 (RR: 1.06; 95% CI: 0.96-1.17). This finding of a significant increase in helmet use after legislation in low- and mid-income areas but not in high-income areas remained even after logistic regression analysis adjusted for sex and location. CONCLUSIONS: This study showed that bicycle helmet use by children increased significantly after helmet legislation. In this urban area with socioeconomic diversity and in the context of prelegislation promotion and educational activities, the legislative effect was most powerful among children who resided in low-income areas.

Accidents, Traffic↗
PubMed2005

Relative transcript quantification by quantitative PCR: roughly right or precisely wrong?

BACKGROUND: When estimating relative transcript abundances by quantitative real-time PCR (Q-PCR) we found that the results can vary dramatically depending on the method chosen for data analysis. RESULTS: Analyses of Q-PCR results from a salmon louse starvation experiment show that, even with apparently good raw data, different analytical approaches 12 may lead to opposing biological conclusions. CONCLUSION: The results emphasise the importance of being cautious when analysing Q-PCR data and indicate that uncritical routine application of an analytical method will eventually result in incorrect conclusions. We do not know the extent of, or have a universal solution to this problem. However, we strongly recommend caution when analysing Q-PCR results e.g. by using two or more analytical approaches to validate conclusions. In our view a common effort should be made to standardise methods for analysis and validation of Q-PCR results.

Animals↗
PubMed2006

Performance goals for the laboratory testing of antithrombin, protein C and protein S.

To achieve a reliable analytical quality for both monitoring and diagnostic testing, laboratories need to fulfil the widely accepted analytical performance goals based on the biological variation of the analytes of testing. Not only is the short-term analytical performance, which regularly is assessed by internal quality control procedures, of importance, but also the long-term analytical performance. To assess the long-term analytical performance, data obtained from an external quality assessment programme can be used. In this study we have used the evaluation model designed by the ECAT Foundation for the assessment of the longterm analytical performance, including imprecision, bias and total analytical error. The model was applied to the data from 136 different laboratories for the assay of antithrombin (activity), protein C (activity and antigen) and protein S (activity, total and free antigen). The imprecision (median; range), reflected by the long-term analytical coefficient of variation (LCV (A) ), was the lowest for antithrombin (7.6%; 2.6 - 43.8%) and the highest for protein S activity (17.2%; 4.3 - 88.6%). For bias and total error the same pattern was observed (antithrombin: 3.8%; 0.3 - 17.1% and 9.1%; 3.4 - 34.3%, respectively; protein S activity: 12.8%; 3.1 - 34.8% and 24.5%; 9.9 - 87.0%, respectively). For the majority of the laboratories (70 - 85%) the imprecision contributes considerably more to the total error than the bias. However the effect of the bias on the analytical quality is not negligible. Assays for antithrombin, protein C and protein S are mainly used for diagnostic testing. About 70 - 100% of the laboratories can fulfil the desirable performance goal for imprecision. The desirable performance goal for bias was reached by 50 - 95% of the laboratories. In all cases the highest numbers of laboratories fulfilling performance goals was obtained for the protein C variables. To improve the analytical quality in assays of antithrombin, protein C and protein S it is highly recommended that primarily imprecision (non-systematic failures) be suppressed. However the effect of the bias (systematic failures) on the analytical quality should not be neglected. A useful tool for determining the imprecision (LCV (A) ) and bias is the long-term analytical performance evaluation model as used by the ECAT Foundation.

Antithrombin III↗
PubMed2002

The learning and application of generic skills by CLSs/MTs who have 'left the field'.

OBJECTIVE: To determine whether generic skills that dinical laboratory scientists (CLSs)/medical technologists (MTs) learned as students and/or practitioners are applied to jobs outside the field of CLS/MT; and to determine if there are any significant differences in learning and/or doing these skills by CLS/MT majors vs. non-CLS/MT majors. DESIGN: An Occupational Change Survey was sent to CLS/MT practitioners who had identified themselves as having left the field (LTF) of CLS/MT. The participants were asked whether or not they were CLS/MT majors as undergraduates, whether they utilized generic baccalaureate level skills in their LTF jobs, and whether or not they learned these skills as CLS/MT students and/or practitioners. The skills were: problem solving, decision making, troubleshooting, analytical reasoning, data correlation, precision studies, quality assessment, teaching, research, communication, technical writing, computer use, utilization review, and supervision. SETTINGS AND PARTICIPANTS: The survey was sent to 105 participants of an ongoing longitudinal study who identified themselves as having LTF. MAIN OUTCOME MEASURES: Responses for doing/utilizing the skills were grouped as 'Yes' if participants indicated they frequently or sometimes used the skills in their LTF jobs, and 'No' if they indicated they rarely or never used the skills in their LTF jobs. Responses for learning the skills were grouped as 'Yes' if participant indicated they learned the skills as CLS/MT students, practitioners or both and 'No' if they indicated they never learned the skills as CLS/MT students, practitioners, or both. Participants indicated whether or not they were CLS/MT majors in college. Chi square analyses were performed to test for any statistical significant (p = 0.05) differences between: doing and learning the skills, doing the skills and being a CLS/MT major, and learning the skills and being a CLS/MT major. RESULTS: The response rate for the survey was 48% (50/103). Chi square analyses could not be performed for doing the skills in the LTF jobs for three variables: problem solving, analytical reasoning, and computer use because all respondents reported that they used these skills. Chi square analyses indicated there were no significant differences between doing and learning the skills in the LTF job for the entire sample group for all remaining skills except supervision. There were no significant differences between doing the skills in the LTF job and being a CLS/MT major. A statistically significant difference in learning the skills was observed between CLS/MT majors and non-CLS/MT majors for the following skills: problem solving, correlating data, precision studies, research, analytical reasoning, and troubleshooting. The 'Yes' answer frequencies for learning the skills was higher for the CLS/ MT majors for all the generic skills except teaching, where they were equal, and utilization studies where they were lower. CONCLUSION: The results indicate that, in general, for this sample group, generic skills learned as CLS/MT students and/or practitioners can be and are applied to a wide variety of LTF jobs. Furthermore, CLS/MT majors learned the generic skills at least as well, if not better, than other baccalaureate level laboratory practitioners who obtained degrees in other areas.

Career Choice↗
PubMed1994

Influence of imaging ability on word transformation.

In the present study, we examined whether individual differences in imaging ability affect visual word recognition. Poor and vivid imagers performed a naming task that involved nonreversed (e.g., JUMP) and reversed (e.g., PMUJ) words (Experiment 1). Poor and vivid imagers were also tested on a naming task that was controlled for verbal ability; all the words were reversed and presentation time was varied (Experiment 2). In both experiments, imaging ability interacted with task difficulty, suggesting that individual differences in imaging ability affect visual word recognition. Specifically, the present data suggest that poor imagers may be less efficient than vivid imagers at processing words analytically. The data are interpreted within a limited-capacity, hybrid, word recognition model, in which words can be processed as either word-level or letter-level codes.

Adult↗
PubMed1979

DIADEM--a system for the interactive data acquisition and processing in an analytical laboratory.

A conversational program for the acquisition of experimental data in a multi-user, multi-instrument computer system is described. It assists the researcher when recording on-time data. Due to the simple structure of the dialogue, no special knowledge of computer handling is required by the experimenter. Whereas the experimental methods are versatile, a uniform concept of the dialogue and the file structure is realized.

Chemistry Techniques, Analytical↗
PubMed1996

Prostate cancer: metabolic response to cryosurgery as detected with 3D H-1 MR spectroscopic imaging.

PURPOSE: To determine, in patients with prostate cancer treated with cryosurgery, whether levels of choline and citrate measured at magnetic resonance (MR) spectroscopy can help discriminate regions of residual tumor from other prostatic tissues and necrosis. MATERIALS AND METHODS: Combined MR imaging and three-dimensional proton spectroscopic imaging were performed in 25 patients (mean age, 69 years) with prostate cancer who underwent cryosurgery. Volume imaging and spectroscopic data were analytically corrected for the reception profile of the endorectal and pelvic phased-array coils. Spectral data were aligned with the MR imaging data and compared with serum prostate-specific antigen levels and biopsy results. RESULTS: Histologically confirmed necrotic tissue (432 voxels) did not demonstrate any observable choline or citrate. The (choline + creatine)/ citrate values in regions of histologically confirmed benign prostatic hyperplasia (0.61 +/- 0.21 [standard deviation], 52 voxels) and cancer (2.4 +/- 1.0, 65 voxels) after cryosurgery were not statistically significantly different from those before therapy but were statistically significantly different from the ratio in necrotic tissue and from each other. The (choline + creatine)/citrate images threshold and overlaid in color on T2-weighted images yielded an estimate of the spatial extent of prostate cancer and benign prostatic hyperplasia. CONCLUSION: Volume MR imaging with MR spectroscopic imaging provided a noninvasive assessment of the presence and location of residual cancer after unsuccessful therapy and helped identify successful cryosurgery in patients who still had an elevated prostate-specific antigen level.

Aged↗
PubMed1998

Intracellular compounds quantification by means of flow cytometry in bacteria: application to xanthan production by Xanthomonas campestris.

The use of flow cytometry (FCM) to quantitatively analyze intracellular compounds is studied. FCM is a very useful technique for individual cell studies in microbial systems, and gives access to information which cannot be obtained in any other way. Nevertheless, it provides data in arbitrary units, that is, relative data. This analytical technique could be employed for kinetic modeling of microbial systems and even for internal phenomena analysis, but for this purpose, absolute data-that is concentration of intracellular compounds-must be used. In this work, relative flow cytometry data are transformed into absolute data by means of calibrations employing the same fluorochromes with another technique: spectrofluorymetry. Calibrations of DNA, RNA, and protein intracellular concentrations are presented for the bacteria, Xanthomonas campestris. Other analytical methods, based on biochemical determinations, were also employed to quantify intracellular compounds, but the results obtained are very poor compared with those achieved by means of spectrofluorymetry (SFM). Calibration equations and data obtained by both techniques are given. Evolutions of protein and nucleic acids during Xanthomonas campestris growth and xanthan gum production are shown.

Bacterial Proteins↗
PubMed1992

A network model for improving access to food and nutrition data.

In this article we propose a network in which existing food composition and consumption databases are linked through a master database of complete and detailed food descriptions. The proposal arises from an analysis of the importance of food data, their descriptive and analytical nature, and their uses. Lack of detail and standardization in food description hinders the retrieval of food and nutrition data from various databases and the integration of such data. Standardized food descriptions can be developed and maintained in the master database, which can then serve as the interface to the many existing databases of analytical data (especially food composition data) and to databases containing data on food production, consumption, and effects, thereby linking these databases in a coordinated system, or network. The ability to link food-related databases by standardized food descriptions offers a powerful tool for scientists and practitioners in the field of food and nutrition.

Computer Communication Networks↗
PubMed1999

Getting data out of the electronic patient record: critical steps in building a data warehouse for decision support.

Health care has taken advantage of computers to streamline many clinical and administrative processes. However, the potential of health care information technology as a source of data for clinical and administrative decision support has not been fully explored. This paper describes the process of developing on-line analytical processing (OLAP) capacity from data generated in an on-line transaction processing (OLTP) system (the electronic patient record). We discuss the steps used to evaluate the EPR system, retrieve the data, and create an analytical data warehouse accessible for analysis. We also summarize studies based on the data (lab re-engineering, practice variation in diagnostic decision-making and evaluation of a clinical alert). Besides producing a useful data warehouse, the process also increased understanding of organizational and cost considerations in purchasing OLAP tools. We discuss the limitations of our approach and ways in which these limitations can be addressed.

Database Management Systems↗
PubMed1984

Physicochemical and analytical characteristics of amiodarone.

Data are reported on the analytical and physicochemical characteristics of amiodarone, for use in identifying and/or assaying this antiarrhythmic agent. The drug is highly soluble in chloroform and poorly soluble in water. Its acid-base constant (pKa) is 6.56, and its maximal lipid solubility range is from pH 3.5 to 5.5.

Amiodarone↗
PubMedDate not supplied

Drug testing in the workplace--are methods legally defensible? A survey of experts, arbitrators, and testing laboratories.

Urinalysis results are increasingly being used by employers to detect use of prohibited substances in the workplace. Actions taken on the basis of positive urinalysis results can have a significant effect on employees' lives and careers, and may face legal challenge. Important aspects of urinalysis are choice of analytical methods and their legal defensibility. Medical directors are frequently required to select testing laboratories, but have had few data correlating analytical methods with legal defensibility. To evaluate the legal defensibility of the methods used for drug testing, we conducted a survey of technical experts, testing laboratories, and arbitrators. Experts reported wide differences in the legal defensibility of methods rated. Arbitrators had considerable experience in drug use cases and understood the critical role of urinalysis results, but were unable to distinguish legal defensibility of analytical methods. Commercial laboratory practice in urinalysis varies widely among laboratories. An objective of this article is to provide company medical directors with information that will enable them to make informed decisions when choosing urinalysis laboratories and methods.

Chemistry, Clinical↗
PubMed2002

A functional genomics approach using metabolomics and in silico pathway analysis.

In the field of functional genomics increasing effort is being undertaken to analyze the function of orphan genes using metabolome data. Improved analytical equipment allows screening simultaneously for a high number of metabolites. Such metabolite profiles are analyzed using multivariate data analysis techniques and changes in the genotype will in many cases lead to different metabolite profiles. Here, a theoretical framework that may be applied to identify the function of orphan genes is presented. The approach is based on a combination of metabolome analysis combined with in silico pathway analysis. Pathway analysis may be carried out using convex analysis and a change in the active pathway structure of deletion mutants expressed in a different metabolite profile may disclose the function or the functional class of an orphan gene. The concept is illustrated using a simplified model for growth of Saccharomyces cerevisiae.

Algorithms↗