Preanalytical Biases in the Measurement of Human Blood Sphingolipids

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Robert Brunkhorst

2018-05-01

Full Text Available Dysregulation of blood sphingolipids is an emerging topic in clinical science. The objective of this study was to determine preanalytical biases that typically occur in clinical and translational studies and that influence measured blood sphingolipid levels. Therefore, we collected blood samples from four healthy male volunteers to investigate the effect of storage conditions (time, temperature, long-term storage, freeze–thaw cycles, blood drawing (venous or arterial sampling, prolonged venous compression, and sample preparation (centrifugation, freezing on sphingolipid levels measured by LC-MS/MS. Our data show that sphingosine 1-phosphate (S1P and sphinganine 1-phosphate (SA1P were upregulated in whole blood samples in a time- and temperature-dependent manner. Increased centrifugation at higher speeds led to lower amounts of S1P and SA1P. All other preanalytical biases did not significantly alter the amounts of S1P and SA1P. Further, in almost all settings, we did not detect differences in (dihydroceramide levels. In summary, besides time-, temperature-, and centrifugation-dependent changes in S1P and SA1P levels, sphingolipids in blood remained stable under practically relevant preanalytical conditions.

Evaluation of Preanalytical Quality Indicators by Six Sigma and Pareto`s Principle.

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Kulkarni, Sweta; Ramesh, R; Srinivasan, A R; Silvia, C R Wilma Delphine

2018-01-01

Preanalytical steps are the major sources of error in clinical laboratory. The analytical errors can be corrected by quality control procedures but there is a need for stringent quality checks in preanalytical area as these processes are done outside the laboratory. Sigma value depicts the performance of laboratory and its quality measures. Hence in the present study six sigma and Pareto principle was applied to preanalytical quality indicators to evaluate the clinical biochemistry laboratory performance. This observational study was carried out for a period of 1 year from November 2015-2016. A total of 1,44,208 samples and 54,265 test requisition forms were screened for preanalytical errors like missing patient information, sample collection details in forms and hemolysed, lipemic, inappropriate, insufficient samples and total number of errors were calculated and converted into defects per million and sigma scale. Pareto`s chart was drawn using total number of errors and cumulative percentage. In 75% test requisition forms diagnosis was not mentioned and sigma value of 0.9 was obtained and for other errors like sample receiving time, stat and type of sample sigma values were 2.9, 2.6, and 2.8 respectively. For insufficient sample and improper ratio of blood to anticoagulant sigma value was 4.3. Pareto`s chart depicts out of 80% of errors in requisition forms, 20% is contributed by missing information like diagnosis. The development of quality indicators, application of six sigma and Pareto`s principle are quality measures by which not only preanalytical, the total testing process can be improved.

Biofluid infrared spectro-diagnostics: pre-analytical considerations for clinical applications.

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Lovergne, L; Bouzy, P; Untereiner, V; Garnotel, R; Baker, M J; Thiéfin, G; Sockalingum, G D

2016-06-23

Several proof-of-concept studies on the vibrational spectroscopy of biofluids have demonstrated that the methodology has promising potential as a clinical diagnostic tool. However, these studies also show that there is a lack of a standardised protocol in sample handling and preparation prior to spectroscopic analysis. One of the most important sources of analytical errors is the pre-analytical phase. For the technique to be translated into clinics, it is clear that a very strict protocol needs to be established for such biological samples. This study focuses on some of the aspects of the pre-analytical phase in the development of the high-throughput Fourier Transform Infrared (FTIR) spectroscopy of some of the most common biofluids such as serum, plasma and bile. Pre-analytical considerations that can impact either the samples (solvents, anti-coagulants, freeze-thaw cycles…) and/or spectroscopic analysis (sample preparation such as drying, deposit methods, volumes, substrates, operators dependence…) and consequently the quality and the reproducibility of spectral data will be discussed in this report.

Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan.

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Najat, Dereen

2017-01-01

Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan. Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician's request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs. The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%), incorrect sample identification (8%) and clotted samples (6%). Most quality control schemes at Sulaimani

Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan.

Directory of Open Access Journals (Sweden)

Dereen Najat

Full Text Available Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan.Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician's request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs.The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%, incorrect sample identification (8% and clotted samples (6%. Most quality control schemes

Preanalytical errors in medical laboratories: a review of the available methodologies of data collection and analysis.

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West, Jamie; Atherton, Jennifer; Costelloe, Seán J; Pourmahram, Ghazaleh; Stretton, Adam; Cornes, Michael

2017-01-01

Preanalytical errors have previously been shown to contribute a significant proportion of errors in laboratory processes and contribute to a number of patient safety risks. Accreditation against ISO 15189:2012 requires that laboratory Quality Management Systems consider the impact of preanalytical processes in areas such as the identification and control of non-conformances, continual improvement, internal audit and quality indicators. Previous studies have shown that there is a wide variation in the definition, repertoire and collection methods for preanalytical quality indicators. The International Federation of Clinical Chemistry Working Group on Laboratory Errors and Patient Safety has defined a number of quality indicators for the preanalytical stage, and the adoption of harmonized definitions will support interlaboratory comparisons and continual improvement. There are a variety of data collection methods, including audit, manual recording processes, incident reporting mechanisms and laboratory information systems. Quality management processes such as benchmarking, statistical process control, Pareto analysis and failure mode and effect analysis can be used to review data and should be incorporated into clinical governance mechanisms. In this paper, The Association for Clinical Biochemistry and Laboratory Medicine PreAnalytical Specialist Interest Group review the various data collection methods available. Our recommendation is the use of the laboratory information management systems as a recording mechanism for preanalytical errors as this provides the easiest and most standardized mechanism of data capture.

The effect of centrifugation speed and time on pre-analytical platelet activation

DEFF Research Database (Denmark)

Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

2016-01-01

BACKGROUND: The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation....... METHODS: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean...... of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p...

Pre-analytic phase in molecular biology: criticism and non-compliance management

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Catia Sias

2010-06-01

Full Text Available Introduction: During workflow in Laboratories the most delicate and important step is pre-analytic sample treatment because it involves more than one operator of the same structure and often different health services. In fact, the biological materials used for the diagnosis should be collected, sent and properly treated before the analytic phase. Correct methods for collecting and handling biological materials, including guidelines to users of laboratory services, improve performance of Laboratory testing activity. In the pre-analytic phase the operators check sample integrity, and prepare the sample for the subsequent analytic phase: in all these steps monitoring and control of “non- compliance” is crucial. Methods: During 2007-2008 we created a “non- compliance” check-list, to monitor errors which occurred in different sectors of the preanalytic phase, particularly in the nucleic acid extraction step. These “non-compliances” are analysed to identify and to remove errors, adopting preventive and corrective proceedings. Since 2008 we have been using DNA/RNA internal controls synthesized in our Laboratory. They can be amplified by the same primers and recognized by different probes. Results: Examination of the “non compliance” check-list for molecular biology investigations shows that the percentage of urine repeat samples decreased from 17% to 2% and the percentage of stool repeat samples from 27% to 2%. Regarding use of internal controls, they allow the assessment of inhibitory factors that can prevent gene amplification. Conclusions: Monitoring “non-compliance” cases and dividing them by typology allow us identifying the most frequent causes of incorrect sample handling, as a non optimal procedure of pre-treatment, thus improving the pre-analytic phase. Therefore by monitoring the preanalytic phase we can prevent the introduction of confounding factors that may negatively influence the accuracy of results and their

The knowledge and understanding of preanalytical phase among biomedicine students at the University of Zagreb.

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Dukic, Lora; Jokic, Anja; Kules, Josipa; Pasalic, Daria

2016-01-01

The educational program for health care personnel is important for reducing preanalytical errors and improving quality of laboratory test results. The aim of our study was to assess the level of knowledge on preanalytical phase in population of biomedicine students through a cross-sectional survey. A survey was sent to students on penultimate and final year of Faculty of Pharmacy and Biochemistry--study of medical biochemistry (FPB), Faculty of Veterinary Medicine (FVM) and School of Medicine (SM), University of Zagreb, Croatia, using the web tool SurveyMonkey. Survey was composed of demographics and 14 statements regarding the preanalytical phase of laboratory testing. Comparison of frequencies and proportions of correct answers was done with Fisher's exact test and test of comparison of proportions, respectively. Study included 135 participants, median age 24 (23-40) years. Students from FPB had higher proportion of correct answers (86%) compared to students from other biomedical faculties 62%, P < 0.001. Students from FPB were more conscious of the importance of specimen mixing (P = 0.027), prevalence of preanalytical errors (P = 0.001), impact of hemolysis (P = 0.032) and lipemia interferences (P = 0.010), proper choice of anticoagulants (P = 0.001), transport conditions for ammonia sample (P < 0.001) and order of draw during blood specimen collection (P < 0.001), in comparison with students from SM and FVM. Students from FPB are more conscious of the importance of preanalytical phase of testing in comparison with their colleagues from other biomedical faculties. No difference in knowledge between penultimate and final year of the same faculty was found.

Preanalytical external quality assessment of the Croatian Society of Medical Biochemistry and Laboratory Medicine and CROQALM: finding undetected weak spots.

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Nikolac, Nora; Krleza, Jasna Lenicek; Simundic, Ana-Maria

2017-02-15

The aim of this paper is to present results of first two years of preanalytical external quality assessment (EQA) in Croatia. This paper summarizes results from 6 rounds of preanalytical EQA during 2014-2016 in 161-175 Croatian laboratories (number ranged between cycles). EQA was designed as an online survey of the compliance with National recommendations for phlebotomy (NRP). Forty-seven questions in 5 categories are analyzed (materials and equipment, patient identification, patient preparation, sampling and storage). Additionally, preanalytical cases are presented. Overall performance scores (Question score (Qscore) for compliance with NRP and Case score (Cscore) for preanalytical cases) are calculated for each question/case as a proportion of laboratories with satisfactory procedure (x 100). Qscores and Cscores ≥ 70 were classified as acceptable (maximal score = 100). In investigation of compliance with NRP, acceptable Qscores were obtained for 34/47 questions. The lowest scores were observed for the availability of sterile disposable tourniquets (Qscore = 15) and safe-sharp needles (Qscore = 34), obtaining patients address as an identifier (Qscore = 21), using glycolysis inhibitor tubes for glucose concentration measurement (Qscore = 21) and verification of manufacturers declarations on temperature and time of storage (Qscore = 31). There was no statistically significant difference in overall Qscore according to different categories of phlebotomy procedures (P = 0.284). The results of preanalytical cases showed acceptable Cscore values for all cases (89-96). First two years of preanalytical EQA showed good compliance with the NRP and excellent expertise in resolving complex preanalytical issues. Major critical spots are lack of availability of safe-sharp needles, disposable tourniquets and glucose inhibitor tubes.

Pre-analytical and analytical variation of drug determination in segmented hair using ultra-performance liquid chromatography-tandem mass spectrometry.

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Nielsen, Marie Katrine Klose; Johansen, Sys Stybe; Linnet, Kristian

2014-01-01

Assessment of total uncertainty of analytical methods for the measurements of drugs in human hair has mainly been derived from the analytical variation. However, in hair analysis several other sources of uncertainty will contribute to the total uncertainty. Particularly, in segmental hair analysis pre-analytical variations associated with the sampling and segmentation may be significant factors in the assessment of the total uncertainty budget. The aim of this study was to develop and validate a method for the analysis of 31 common drugs in hair using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with focus on the assessment of both the analytical and pre-analytical sampling variations. The validated method was specific, accurate (80-120%), and precise (CV≤20%) across a wide linear concentration range from 0.025-25 ng/mg for most compounds. The analytical variation was estimated to be less than 15% for almost all compounds. The method was successfully applied to 25 segmented hair specimens from deceased drug addicts showing a broad pattern of poly-drug use. The pre-analytical sampling variation was estimated from the genuine duplicate measurements of two bundles of hair collected from each subject after subtraction of the analytical component. For the most frequently detected analytes, the pre-analytical variation was estimated to be 26-69%. Thus, the pre-analytical variation was 3-7 folds larger than the analytical variation (7-13%) and hence the dominant component in the total variation (29-70%). The present study demonstrated the importance of including the pre-analytical variation in the assessment of the total uncertainty budget and in the setting of the 95%-uncertainty interval (±2CVT). Excluding the pre-analytical sampling variation could significantly affect the interpretation of results from segmental hair analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Novel Opportunities for Improving the Quality of Preanalytical Phase. A Glimpse to the Future?

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Lippi Giuseppe

2017-08-01

Full Text Available The preanalytical phase is crucial for assuring the quality of in vitro diagnostics. The leading aspects which contribute to enhance the vulnerability of this part of the total testing process include the lack of standardization of different practices for collecting, managing, transporting and processing biological specimens, the insufficient compliance with available guidelines and the still considerable number of preventable human errors. As in heavy industry, road traffic and aeronautics, technological advancement holds great promise for decreasing the risk of medical and diagnostic errors, thus including those occurring in the extra-analytical phases of the total testing process. The aim of this article is to discuss some potentially useful technological advances, which are not yet routine practice, but may be especially suited for improving the quality of the preanalytical phase in the future. These are mainly represented by introduction of needlewielding robotic phlebotomy devices, active blood tubes, drones for biological samples transportation, innovative approaches for detecting spurious hemolysis and preanalytical errors recording software products.

EFLM WG-Preanalytical phase opinion paper

DEFF Research Database (Denmark)

Lippi, Giuseppe; Cornes, Michael P; Grankvist, Kjell

2016-01-01

The selection or procurement of blood collection devices in healthcare facilities is often an underestimated issue. This is probably due to different factors including the lack of knowledge of policymakers, hospital administrators and even laboratory managers about the importance of preanalytical...... quality and phlebotomy process, as well as to the absence of reliable guidelines or recommendations on how to precisely assess the quality of blood collection devices around the globe. With the awareness that a gap remains between manufacturers' and local validation of blood collection devices...

Review of Pre-Analytical Errors in Oral Glucose Tolerance Testing in a Tertiary Care Hospital.

Science.gov (United States)

Nanda, Rachita; Patel, Suprava; Sahoo, Sibashish; Mohapatra, Eli

2018-03-13

The pre-pre-analytical and pre-analytical phases form a major chunk of the errors in a laboratory. The process has taken into consideration a very common procedure which is the oral glucose tolerance test to identify the pre-pre-analytical errors. Quality indicators provide evidence of quality, support accountability and help in the decision making of laboratory personnel. The aim of this research is to evaluate pre-analytical performance of the oral glucose tolerance test procedure. An observational study that was conducted overa period of three months, in the phlebotomy and accessioning unit of our laboratory using questionnaire that examined the pre-pre-analytical errors through a scoring system. The pre-analytical phase was analyzed for each sample collected as per seven quality indicators. About 25% of the population gave wrong answer with regard to the question that tested the knowledge of patient preparation. The appropriateness of test result QI-1 had the most error. Although QI-5 for sample collection had a low error rate, it is a very important indicator as any wrongly collected sample can alter the test result. Evaluating the pre-analytical and pre-pre-analytical phase is essential and must be conducted routinely on a yearly basis to identify errors and take corrective action and to facilitate their gradual introduction into routine practice.

The knowledge and understanding of preanalytical phase among biomedicine students at the University of Zagreb

Science.gov (United States)

Dukic, Lora; Jokic, Anja; Kules, Josipa; Pasalic, Daria

2016-01-01

Introduction The educational program for health care personnel is important for reducing preanalytical errors and improving quality of laboratory test results. The aim of our study was to assess the level of knowledge on preanalytical phase in population of biomedicine students through a cross-sectional survey. Materials and methods A survey was sent to students on penultimate and final year of Faculty of Pharmacy and Biochemistry – study of medical biochemistry (FPB), Faculty of Veterinary Medicine (FVM) and School of Medicine (SM), University of Zagreb, Croatia, using the web tool SurveyMonkey. Survey was composed of demographics and 14 statements regarding the preanalytical phase of laboratory testing. Comparison of frequencies and proportions of correct answers was done with Fisher’s exact test and test of comparison of proportions, respectively. Results Study included 135 participants, median age 24 (23-40) years. Students from FPB had higher proportion of correct answers (86%) compared to students from other biomedical faculties 62%, P sample (P order of draw during blood specimen collection (P < 0.001), in comparison with students from SM and FVM. Conclusions Students from FPB are more conscious of the importance of preanalytical phase of testing in comparison with their colleagues from other biomedical faculties. No difference in knowledge between penultimate and final year of the same faculty was found. PMID:26981023

Pre-analytical Factors Influence Accuracy of Urine Spot Iodine Assessment in Epidemiological Surveys.

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Doggui, Radhouene; El Ati-Hellal, Myriam; Traissac, Pierre; El Ati, Jalila

2018-03-26

Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12 years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50 μg/L and the proportion of UIC analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.

Pre-analytical factors influencing the stability of cerebrospinal fluid proteins

DEFF Research Database (Denmark)

Simonsen, Anja H; Bahl, Justyna M C; Danborg, Pia B

2013-01-01

Cerebrospinal fluid (CSF) is a potential source for new biomarkers due to its proximity to the brain. This study aimed to clarify the stability of the CSF proteome when undergoing pre-analytical factors. We investigated the effects of repeated freeze/thaw cycles, protease inhibitors and delayed s...

Intensive educational efforts combined with external quality assessment improve the preanalytical phase in general practitioner offices and nursing homes.

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Sølvik, Una Ørvim; Bjelkarøy, Wenche Iren; Berg, Kari van den; Saga, Anne Lise; Hager, Helle Borgstrøm; Sandberg, Sverre

2017-10-26

Errors in the preanalytical phase in clinical laboratories affect patient safety. The aim of this study was to evaluate the effect of intensive educational efforts together with external quality assessment (EQA) of the preanalytical phase from 2013 to 2015 to improve patient identification in primary health care in Norway. In addition, routines for venous and capillary blood sampling were investigated. A preanalytical EQA was circulated in 2013 by the Norwegian Quality Improvement of Laboratory Examinations (Noklus) to general practitioner offices and nursing homes (n=2000) to obtain information about important issues to focus on before launching an intensive educational program with courses, posters and visits in 2013-2015. Preanalytical EQA surveys were further circulated in 2014 and 2015. The response rate varied between 42% and 55%. The percentages of participants asking for the patients' name and the Norwegian identification number increased from about 8% in 2013 to about 35% in 2015. The increase was similar for those participating in only one EQA survey and for those who participated in EQA surveys both in 2013 and 2015. Guidelines for venous and capillary blood sampling were not always followed. Educational efforts more than the preanalytical EQA influenced the actions and resulted in an increase in the percentages of participants that followed the guidelines for patient identification. Some aspects of blood sampling routines need improvement.

Misleading hallucinations in unrecognized narcolepsy.

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Szucs, A; Janszky, J; Holló, A; Migléczi, G; Halász, P

2003-10-01

To describe psychosis-like hallucinatory states in unrecognized narcolepsy. Two patients with hypnagogic/hypnapompic hallucinations are presented. Both patients had realistic and complex - multi-modal and scenic-daytime sexual hallucinations leading, in the first case, to a legal procedure because of false accusation, and in the second, to serious workplace conflicts. Both patients were convinced of the reality of their hallucinatory experiences but later both were able to recognize their hallucinatory character. Clinical data, a multiple sleep latency test, polysomnography, and HLA typing revealed that both patients suffered from narcolepsy. We suggest that in unrecognized narcolepsy with daytime hypnagogic/hypnapompic hallucinations the diagnostic procedure may mistakenly incline towards delusional psychoses. Daytime realistic hypnagogic/hypnapompic hallucinations may also have forensic consequences and mislead legal evaluation. Useful clinical features in differentiating narcolepsy from psychoses are: the presence of other narcoleptic symptoms, features of hallucinations, and response to adequate medication.

The role of European Federation of Clinical Chemistry and Laboratory Medicine Working Group for Preanalytical Phase in standardization and harmonization of the preanalytical phase in Europe

NARCIS (Netherlands)

Cornes, Michael P.; Church, Stephen; van Dongen-Lases, Edmée; Grankvist, Kjell; Guimarães, João T.; Ibarz, Mercedes; Kovalevskaya, Svetlana; Kristensen, Gunn Bb; Lippi, Giuseppe; Nybo, Mads; Sprongl, Ludek; Sumarac, Zorica; Simundic, Ana-Maria

2016-01-01

Patient safety is a leading challenge in healthcare and from the laboratory perspective it is now well established that preanalytical errors are the major contributor to the overall rate of diagnostic and therapeutic errors. To address this, the European Federation of Clinical Chemistry and

Preanalytical quality improvement – in quality we trust

OpenAIRE

Lippi, G; Salvagno, GL; Lima-Oliveira, G; Funk-Adcock, DM; Guidi, GC; Favaloro, EJ; Biljak Radišić, V; Božičević, S; Vučić Lovrenčić, M; Milinković, N; Šumarac, Z; Ignjatović, S; Majkić-Singh, N; Trujillo Arribas, E; Camacho Martinez, P

2013-01-01

Background The preanalytical phase represents the major source of variability in laboratory diagnostics. Our aim was to assess to what extent underfilling of primary blood tubes may impact upon routine coagulation testing. Materials and methods: Blood was drawn by syringe from 21 healthy volunteers and 6 patients on warfarin therapy, and immediately transferred into 3.6 mL vacuum tubes containing 3.2% sodium citrate (Terumo Europe N.V., Leuven, Belgium). All tubes were filled using standardiz...

Pre-analytical variables of circulating cell-free nucleosomes containing 5-methylcytosine DNA or histone modification H3K9Me3

DEFF Research Database (Denmark)

Rasmussen, Louise; Herzog, Marielle; Rømer, Eva

2016-01-01

Aim: To evaluate pre-analytical variables of circulating cell-free nucleosomes containing 5-methylcytosine DNA (5mC) or histone modification H3K9Me3 (H3K9Me3). Materials and methods: Six studies were designed to assess the possible influence of pre-analytical variables. Study 1: influence of stasis...... significantly lower levels of 5mC or H3K9Me3 compared to levels in healthy individuals. Conclusion: Levels of 5mC or H3K9Me3 appear stable in most pre-analytical settings if blood samples are stored at room temperature until centrifugation....

The effect of centrifugation speed and time on pre-analytical platelet activation.

Science.gov (United States)

Söderström, Anna C; Nybo, Mads; Nielsen, Christian; Vinholt, Pernille J

2016-12-01

The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation. Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry. The median percentage of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), pcentrifuged. In platelet-rich plasma, increasing centrifugation speed significantly increased platelet yield but decreased contamination from other blood cells, platelet composition was altered as platelet parameters (MPV, IPF, and PDW) was lowered. Platelet aggregation was not affected by the centrifugation speed platelet-rich plasma was prepared. Proportional to centrifugation speed, platelets in plasma and platelet-rich plasma were activated with centrifugation speed, cell content and composition changed while platelet aggregation was unaltered.

The preanalytical optimization of blood cultures: a review and the clinical importance of benchmarking in 5 Belgian hospitals.

Science.gov (United States)

Willems, Elise; Smismans, Annick; Cartuyvels, Reinoud; Coppens, Guy; Van Vaerenbergh, Kristien; Van den Abeele, Anne-Marie; Frans, Johan

2012-05-01

Bloodstream infections remain a major challenge in medicine. Optimal detection of pathogens is only possible if the quality of preanalytical factors is thoroughly controlled. Since the laboratory is responsible for this preanalytical phase, the quality control of critical factors should be integrated in its quality control program. The numerous recommendations regarding blood culture collection contain controversies. Only an unambiguous guideline permits standardization and interlaboratory quality control. We present an evidence-based concise guideline of critical preanalytical determinants for blood culture collection and summarize key performance indicators with their concomitant target values. In an attempt to benchmark, we compared the true-positive rate, contamination rate, and collected blood volume of blood culture bottles in 5 Belgian hospital laboratories. The true-positive blood culture rate fell within previously defined acceptation criteria by Baron et al. (2005) in all 5 hospitals, whereas the contamination rate exceeded the target value in 4 locations. Most unexpected, in each of the 5 laboratories, more than one third of the blood culture bottles were incorrectly filled, irrespective of the manufacturer of the blood culture vials. As a consequence of this shortcoming, one manufacturer recently developed an automatic blood volume monitoring system. In conclusion, clear recommendations for standardized blood culture collection combined with quality control of critical factors of the preanalytical phase are essential for diagnostic blood culture improvement. Copyright © 2012 Elsevier Inc. All rights reserved.

Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

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Walz, Johanna M; Boehringer, Daniel; Deissler, Heidrun L; Faerber, Lothar; Goepfert, Jens C; Heiduschka, Peter; Kleeberger, Susannah M; Klettner, Alexa; Krohne, Tim U; Schneiderhan-Marra, Nicole; Ziemssen, Focke; Stahl, Andreas

2016-01-01

Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements. Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center) twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD), cannula (butterfly vs. neonatal), type of centrifuge (swing-out vs. fixed-angle), time before and after centrifugation, filling level (completely filled vs. half-filled tubes) and analyzing method (ELISA vs. multiplex bead array). Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model. The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes. VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

Directory of Open Access Journals (Sweden)

Johanna M Walz

Full Text Available Vascular endothelial growth factor-A (VEGF-A is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD, cannula (butterfly vs. neonatal, type of centrifuge (swing-out vs. fixed-angle, time before and after centrifugation, filling level (completely filled vs. half-filled tubes and analyzing method (ELISA vs. multiplex bead array. Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

Impact of Educational Activities in Reducing Pre-Analytical Laboratory Errors: A quality initiative.

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Al-Ghaithi, Hamed; Pathare, Anil; Al-Mamari, Sahimah; Villacrucis, Rodrigo; Fawaz, Naglaa; Alkindi, Salam

2017-08-01

Pre-analytic errors during diagnostic laboratory investigations can lead to increased patient morbidity and mortality. This study aimed to ascertain the effect of educational nursing activities on the incidence of pre-analytical errors resulting in non-conforming blood samples. This study was conducted between January 2008 and December 2015. All specimens received at the Haematology Laboratory of the Sultan Qaboos University Hospital, Muscat, Oman, during this period were prospectively collected and analysed. Similar data from 2007 were collected retrospectively and used as a baseline for comparison. Non-conforming samples were defined as either clotted samples, haemolysed samples, use of the wrong anticoagulant, insufficient quantities of blood collected, incorrect/lack of labelling on a sample or lack of delivery of a sample in spite of a sample request. From 2008 onwards, multiple educational training activities directed at the hospital nursing staff and nursing students primarily responsible for blood collection were implemented on a regular basis. After initiating corrective measures in 2008, a progressive reduction in the percentage of non-conforming samples was observed from 2009 onwards. Despite a 127.84% increase in the total number of specimens received, there was a significant reduction in non-conforming samples from 0.29% in 2007 to 0.07% in 2015, resulting in an improvement of 75.86% ( P educational activities directed primarily towards hospital nursing staff had a positive impact on the quality of laboratory specimens by significantly reducing pre-analytical errors.

Importance and Impact of Preanalytical Variables on Alzheimer Disease Biomarker Concentrations in Cerebrospinal Fluid

NARCIS (Netherlands)

Le Bastard, Nathalie; De Deyn, Peter Paul; Engelborghs, Sebastiaan

BACKGROUND: Analyses of cerebrospinal fluid (CSF) biomarkers (beta-amyloid protein, total tau protein, and hyperphosphorylated tau protein) are part of the diagnostic criteria of Alzheimer disease. Different preanalytical sample procedures contribute to variability of CSF biomarker concentrations,

[Quality Management and Quality Specifications of Laboratory Tests in Clinical Studies--Challenges in Pre-Analytical Processes in Clinical Laboratories].

Science.gov (United States)

Ishibashi, Midori

2015-01-01

The cost, speed, and quality are the three important factors recently indicated by the Ministry of Health, Labour and Welfare (MHLW) for the purpose of accelerating clinical studies. Based on this background, the importance of laboratory tests is increasing, especially in the evaluation of clinical study participants' entry and safety, and drug efficacy. To assure the quality of laboratory tests, providing high-quality laboratory tests is mandatory. For providing adequate quality assurance in laboratory tests, quality control in the three fields of pre-analytical, analytical, and post-analytical processes is extremely important. There are, however, no detailed written requirements concerning specimen collection, handling, preparation, storage, and shipping. Most laboratory tests for clinical studies are performed onsite in a local laboratory; however, a part of laboratory tests is done in offsite central laboratories after specimen shipping. As factors affecting laboratory tests, individual and inter-individual variations are well-known. Besides these factors, standardizing the factors of specimen collection, handling, preparation, storage, and shipping, may improve and maintain the high quality of clinical studies in general. Furthermore, the analytical method, units, and reference interval are also important factors. It is concluded that, to overcome the problems derived from pre-analytical processes, it is necessary to standardize specimen handling in a broad sense.

Pre-analytic process control: projecting a quality image.

Science.gov (United States)

Serafin, Mark D

2006-09-26

Within the health-care system, the term "ancillary department" often describes the laboratory. Thus, laboratories may find it difficult to define their image and with it, customer perception of department quality. Regulatory requirements give laboratories who so desire an elegant way to address image and perception issues--a comprehensive pre-analytic system solution. Since large laboratories use such systems--laboratory service manuals--I describe and illustrate the process for the benefit of smaller facilities. There exist resources to help even small laboratories produce a professional service manual--an elegant solution to image and customer perception of quality.

Chasing the Effects of Pre-Analytical Confounders - A Multicenter Study on CSF-AD Biomarkers

DEFF Research Database (Denmark)

Leitão, Maria João; Baldeiras, Inês; Herukka, Sanna-Kaisa

2015-01-01

INTRODUCTION: Core cerebrospinal fluid (CSF) biomarkers - Aβ42, Tau, and phosphorylated Tau (pTau) - have been recently incorporated in the revised criteria for Alzheimer's disease (AD). However, their widespread clinical application lacks standardization. Pre-analytical sample handling and storage...

Identification of clinical biomarkers for pre-analytical quality control of blood samples.

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Kang, Hyun Ju; Jeon, Soon Young; Park, Jae-Sun; Yun, Ji Young; Kil, Han Na; Hong, Won Kyung; Lee, Mee-Hee; Kim, Jun-Woo; Jeon, Jae-Pil; Han, Bok Ghee

2013-04-01

Pre-analytical conditions are key factors in maintaining the high quality of biospecimens. They are necessary for accurate reproducibility of experiments in the field of biomarker discovery as well as achieving optimal specificity of laboratory tests for clinical diagnosis. In research at the National Biobank of Korea, we evaluated the impact of pre-analytical conditions on the stability of biobanked blood samples by measuring biochemical analytes commonly used in clinical laboratory tests. We measured 10 routine laboratory analytes in serum and plasma samples from healthy donors (n = 50) with a chemistry autoanalyzer (Hitachi 7600-110). The analyte measurements were made at different time courses based on delay of blood fractionation, freezing delay of fractionated serum and plasma samples, and at different cycles (0, 1, 3, 6, 9) of freeze-thawing. Statistically significant changes from the reference sample mean were determined using the repeated-measures ANOVA and the significant change limit (SCL). The serum levels of GGT and LDH were changed significantly depending on both the time interval between blood collection and fractionation and the time interval between fractionation and freezing of serum and plasma samples. The glucose level was most sensitive only to the elapsed time between blood collection and centrifugation for blood fractionation. Based on these findings, a simple formula (glucose decrease by 1.387 mg/dL per hour) was derived to estimate the length of time delay after blood collection. In addition, AST, BUN, GGT, and LDH showed sensitive responses to repeated freeze-thaw cycles of serum and plasma samples. These results suggest that GGT and LDH measurements can be used as quality control markers for certain pre-analytical conditions (eg, delayed processing or repeated freeze-thawing) of blood samples which are either directly used in the laboratory tests or stored for future research in the biobank.

Preanalytical and analytical variation of surface-enhanced laser desorption-ionization time-of-flight mass spectrometry of human serum

DEFF Research Database (Denmark)

Albrethsen, Jakob; Bøgebo, Rikke; Olsen, Jesper

2006-01-01

BACKGROUND: Surface-enhanced laser desorption-ionization time-of-flight (SELDI-TOF) mass spectrometry of human serum is a potential diagnostic tool in human diseases. In the present study, the preanalytical and analytical variation of SELDI-TOF mass spectrometry of serum was assessed in healthy...... was 18% (6%-34%, n=4) for 16 peaks, and inter-individual CV was 38% (16%-56%, n=16) for 20 peaks. CONCLUSIONS: The pre-analytical and analytical conditions of SELDI-TOF mass spectrometry of serum have a significant impact on the protein peaks, with the number of peaks low and the assay variation high...

Pre-Analytical Conditions in Non-Invasive Prenatal Testing of Cell-Free Fetal RHD

DEFF Research Database (Denmark)

Clausen, Frederik Banch; Jakobsen, Tanja Roien; Rieneck, Klaus

2013-01-01

D positive fetus. Prophylaxis reduces the risk of immunization that may lead to hemolytic disease of the fetus and the newborn. The reliability of predicting the fetal RhD type depends on pre-analytical factors and assay sensitivity. We evaluated the testing setup in the Capital Region of Denmark, based...

Pre-analytic phase in molecular biology: criticism and non-compliance management

OpenAIRE

Catia Sias; Loredana Aleo; Stefania Di Filippo; Marco Paterno; Anna Rosa Garbuglia; Maria Rosaria Capobianchi

2010-01-01

Introduction: During workflow in Laboratories the most delicate and important step is pre-analytic sample treatment because it involves more than one operator of the same structure and often different health services. In fact, the biological materials used for the diagnosis should be collected, sent and properly treated before the analytic phase. Correct methods for collecting and handling biological materials, including guidelines to users of laboratory services, improve performance of Labor...

Dried blood spot specimen quality and validation of a new pre-analytical processing method for qualitative HIV-1 PCR, KwaZulu-Natal, South Africa.

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Govender, Kerusha; Parboosing, Raveen; Siyaca, Ntombizandile; Moodley, Pravikrishnen

2016-01-01

Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume. This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method. Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed. Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems. Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997. The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care.

Dried blood spot specimen quality and validation of a new pre-analytical processing method for qualitative HIV-1 PCR, KwaZulu-Natal, South Africa

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Parboosing, Raveen; Siyaca, Ntombizandile; Moodley, Pravikrishnen

2016-01-01

Background Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume. Objectives This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method. Methods Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed. Results Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems. Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997. Conclusions The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care. PMID:28879108

Effect of pre-analytical handling on haematological variables in minipigs

DEFF Research Database (Denmark)

Olsen, A K; Bladbjerg, E-M; Jensen, A L

2001-01-01

Pre-analytical handling may be an important determinant of haematological variables, if analysis is delayed. We investigated the effect of anticoagulants, i.e. tripotassium ethylenediamine-tetraacetic acid (EDTA) and citric acid, theophylline, adenosine, dipyridamole (CTAD), storage time (0.5, 1......, the samples must be stored in a refrigerator until analysis. Our studies underline that time delay before analysis of haematological variables can cause increased variation, and should therefore be limited as far as possible in order to reduce the number of animals needed to make reliable conclusions...

Exploring the initial steps of the testing process: frequency and nature of pre-preanalytic errors.

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Carraro, Paolo; Zago, Tatiana; Plebani, Mario

2012-03-01

Few data are available on the nature of errors in the so-called pre-preanalytic phase, the initial steps of the testing process. We therefore sought to evaluate pre-preanalytic errors using a study design that enabled us to observe the initial procedures performed in the ward, from the physician's test request to the delivery of specimens in the clinical laboratory. After a 1-week direct observational phase designed to identify the operating procedures followed in 3 clinical wards, we recorded all nonconformities and errors occurring over a 6-month period. Overall, the study considered 8547 test requests, for which 15 917 blood sample tubes were collected and 52 982 tests undertaken. No significant differences in error rates were found between the observational phase and the overall study period, but underfilling of coagulation tubes was found to occur more frequently in the direct observational phase (P = 0.043). In the overall study period, the frequency of errors was found to be particularly high regarding order transmission [29 916 parts per million (ppm)] and hemolysed samples (2537 ppm). The frequency of patient misidentification was 352 ppm, and the most frequent nonconformities were test requests recorded in the diary without the patient's name and failure to check the patient's identity at the time of blood draw. The data collected in our study confirm the relative frequency of pre-preanalytic errors and underline the need to consensually prepare and adopt effective standard operating procedures in the initial steps of laboratory testing and to monitor compliance with these procedures over time.

Preanalytical errors in primary healthcare: a questionnaire study of information search procedures, test request management and test tube labelling.

Science.gov (United States)

Söderberg, Johan; Brulin, Christine; Grankvist, Kjell; Wallin, Olof

2009-01-01

Most errors in laboratory medicine occur in the preanalytical phase and are the result of human mistakes. This study investigated information search procedures, test request management and test tube labelling in primary healthcare compared to the same procedures amongst clinical laboratory staff. A questionnaire was completed by 317 venous blood sampling staff in 70 primary healthcare centres and in two clinical laboratories (response rate = 94%). Correct procedures were not always followed. Only 60% of the primary healthcare staff reported that they always sought information in the updated, online laboratory manual. Only 12% reported that they always labelled the test tubes prior to drawing blood samples. No major differences between primary healthcare centres and clinical laboratories were found, except for test tube labelling, whereby the laboratory staff reported better practices. Re-education and access to documented routines were not clearly associated with better practices. The preanalytical procedure in the surveyed primary healthcare centres was associated with a risk of errors which could affect patient safety. To improve patient safety in laboratory testing, all healthcare providers should survey their preanalytical procedures and improve the total testing process with a systems perspective.

Pre-analytical and analytical factors influencing Alzheimer's disease cerebrospinal fluid biomarker variability.

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Fourier, Anthony; Portelius, Erik; Zetterberg, Henrik; Blennow, Kaj; Quadrio, Isabelle; Perret-Liaudet, Armand

2015-09-20

A panel of cerebrospinal fluid (CSF) biomarkers including total Tau (t-Tau), phosphorylated Tau protein at residue 181 (p-Tau) and β-amyloid peptides (Aβ42 and Aβ40), is frequently used as an aid in Alzheimer's disease (AD) diagnosis for young patients with cognitive impairment, for predicting prodromal AD in mild cognitive impairment (MCI) subjects, for AD discrimination in atypical clinical phenotypes and for inclusion/exclusion and stratification of patients in clinical trials. Due to variability in absolute levels between laboratories, there is no consensus on medical cut-off value for the CSF AD signature. Thus, for full implementation of this core AD biomarker panel in clinical routine, this issue has to be solved. Variability can be explained both by pre-analytical and analytical factors. For example, the plastic tubes used for CSF collection and storage, the lack of reference material and the variability of the analytical protocols were identified as important sources of variability. The aim of this review is to highlight these pre-analytical and analytical factors and describe efforts done to counteract them in order to establish cut-off values for core CSF AD biomarkers. This review will give the current state of recommendations. Copyright © 2015. Published by Elsevier B.V.

Tissue is alive: New technologies are needed to address the problems of protein biomarker pre-analytical variability.

Science.gov (United States)

Espina, Virginia; Mueller, Claudius; Edmiston, Kirsten; Sciro, Manuela; Petricoin, Emanuel F; Liotta, Lance A

2009-08-01

Instability of tissue protein biomarkers is a critical issue for molecular profiling. Pre-analytical variables during tissue procurement, such as time delays during which the tissue remains stored at room temperature, can cause significant variability and bias in downstream molecular analysis. Living tissue, ex vivo, goes through a defined stage of reactive changes that begin with oxidative, hypoxic and metabolic stress, and culminate in apoptosis. Depending on the delay time ex vivo, and reactive stage, protein biomarkers, such as signal pathway phosphoproteins will be elevated or suppressed in a manner which does not represent the biomarker levels at the time of excision. Proteomic data documenting reactive tissue protein changes post collection indicate the need to recognize and address tissue stability, preservation of post-translational modifications, and preservation of morphologic features for molecular analysis. Based on the analysis of phosphoproteins, one of the most labile tissue protein biomarkers, we set forth tissue procurement guidelines for clinical research. We propose technical solutions for (i) assessing the state of protein analyte preservation and specimen quality via identification of a panel of natural proteins (surrogate stability markers), and (ii) using multi-purpose fixative solution designed to stabilize, preserve and maintain proteins, nucleic acids, and tissue architecture.

Pre-analytical method for NMR-based grape metabolic fingerprinting and chemometrics.

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Ali, Kashif; Maltese, Federica; Fortes, Ana Margarida; Pais, Maria Salomé; Verpoorte, Robert; Choi, Young Hae

2011-10-10

Although metabolomics aims at profiling all the metabolites in organisms, data quality is quite dependent on the pre-analytical methods employed. In order to evaluate current methods, different pre-analytical methods were compared and used for the metabolic profiling of grapevine as a model plant. Five grape cultivars from Portugal in combination with chemometrics were analyzed in this study. A common extraction method with deuterated water and methanol was found effective in the case of amino acids, organic acids, and sugars. For secondary metabolites like phenolics, solid phase extraction with C-18 cartridges showed good results. Principal component analysis, in combination with NMR spectroscopy, was applied and showed clear distinction among the cultivars. Primary metabolites such as choline, sucrose, and leucine were found discriminating for 'Alvarinho', while elevated levels of alanine, valine, and acetate were found in 'Arinto' (white varieties). Among the red cultivars, higher signals for citrate and GABA in 'Touriga Nacional', succinate and fumarate in 'Aragonês', and malate, ascorbate, fructose and glucose in 'Trincadeira', were observed. Based on the phenolic profile, 'Arinto' was found with higher levels of phenolics as compared to 'Alvarinho'. 'Trincadeira' showed lowest phenolics content while higher levels of flavonoids and phenylpropanoids were found in 'Aragonês' and 'Touriga Nacional', respectively. It is shown that the metabolite composition of the extract is highly affected by the extraction procedure and this consideration has to be taken in account for metabolomics studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Plasma tissue inhibitor of metalloproteinases-1 as a biological marker? Pre-analytical considerations

DEFF Research Database (Denmark)

Lomholt, Anne Fog; Frederiksen, Camilla; Christensen, Ib Jarle

2007-01-01

Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) may be a valuable biological marker in Colorectal Cancer (CRC). However, prospective validation of TIMP-1 as a biological marker should include a series of pre-analytical considerations. TIMP-1 is stored in platelets, which may degranulate during ...... collection and storage. The aim of this study was to evaluate the influence of platelet TIMP-1 contamination on plasma TIMP-1 levels in healthy volunteers....

Increased Patient Satisfaction and a Reduction in Pre-Analytical Errors Following Implementation of an Electronic Specimen Collection Module in Outpatient Phlebotomy.

Science.gov (United States)

Kantartjis, Michalis; Melanson, Stacy E F; Petrides, Athena K; Landman, Adam B; Bates, David W; Rosner, Bernard A; Goonan, Ellen; Bixho, Ida; Tanasijevic, Milenko J

2017-08-01

Patient satisfaction in outpatient phlebotomy settings typically depends on wait time and venipuncture experience, and many patients equate their experiences with their overall satisfaction with the hospital. We compared patient service times and preanalytical errors pre- and postimplementation of an integrated electronic health record (EHR)-laboratory information system (LIS) and electronic specimen collection module. We also measured patient wait time and assessed patient satisfaction using a 5-question survey. The percentage of patients waiting less than 10 minutes increased from 86% preimplementation to 93% postimplementation of the EHR-LIS (P ≤.001). The median total service time decreased significantly, from 6 minutes (IQR, 4-8 minutes), to 5 minutes (IQR, 3-6 minutes) (P = .005). The preanalytical errors decreased significantly, from 3.20 to 1.93 errors per 1000 specimens (P ≤.001). Overall patient satisfaction improved, with an increase in excellent responses for all 5 questions (P ≤.001). We found several benefits of implementing an electronic specimen collection module, including decreased wait and service times, improved patient satisfaction, and a reduction in preanalytical errors. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Bias due to Preanalytical Dilution of Rodent Serum for Biochemical Analysis on the Siemens Dimension Xpand Plus

Directory of Open Access Journals (Sweden)

Jennifer L. Johns

2018-02-01

Full Text Available Clinical pathology testing of rodents is often challenging due to insufficient sample volume. One solution in clinical veterinary and exploratory research environments is dilution of samples prior to analysis. However, published information on the impact of preanalytical sample dilution on rodent biochemical data is incomplete. The objective of this study was to evaluate the effects of preanalytical sample dilution on biochemical analysis of mouse and rat serum samples utilizing the Siemens Dimension Xpand Plus. Rats were obtained from end of study research projects. Mice were obtained from sentinel testing programs. For both, whole blood was collected via terminal cardiocentesis into empty tubes and serum was harvested. Biochemical parameters were measured on fresh and thawed frozen samples run straight and at dilution factors 2–10. Dilutions were performed manually, utilizing either ultrapure water or enzyme diluent per manufacturer recommendations. All diluted samples were generated directly from the undiluted sample. Preanalytical dilution caused clinically unacceptable bias in most analytes at dilution factors four and above. Dilution-induced bias in total calcium, creatinine, total bilirubin, and uric acid was considered unacceptable with any degree of dilution, based on the more conservative of two definitions of acceptability. Dilution often caused electrolyte values to fall below assay range precluding evaluation of bias. Dilution-induced bias occurred in most biochemical parameters to varying degrees and may render dilution unacceptable in the exploratory research and clinical veterinary environments. Additionally, differences between results obtained at different dilution factors may confound statistical comparisons in research settings. Comparison of data obtained at a single dilution factor is highly recommended.

Prevalence and Significance of Unrecognized Lower Extremity Peripheral Arterial Disease in General Medicine Practice

Science.gov (United States)

McGrae McDermott, Mary; Kerwin, Diana R; Liu, Kiang; Martin, Gary J; O'Brien, Erin; Kaplan, Heather; Greenland, Philip

2001-01-01

OBJECTIVE To determine the prevalence of unrecognized lower extremity peripheral arterial disease (PAD) among men and women aged 55 years and older in a general internal medicine (GIM) practice and to identify characteristics and functional performance associated with unrecognized PAD. DESIGN Cross-sectional. SETTING Academic medical center. PARTICIPANTS We identified 143 patients with known PAD from the noninvasive vascular laboratory, and 239 men and women aged 55 and older with no prior PAD history from a GIM practice. Group 1 consisted of patients with PAD consecutively identified from the noninvasive vascular laboratory (n = 143). Group 2 included GIM practice patients found to have an ankle brachial index less than 0.90, consistent with PAD (n = 34). Group 3 consisted of GIM practice patients without PAD (n = 205). MEASUREMENTS AND MAIN RESULTS Leg functioning was assessed with the 6-minute walk, 4-meter walking velocity, and Walking Impairment Questionnaire (WIQ). Of GIM practice patients, 14% had unrecognized PAD. Only 44% of patients in Group 2 had exertional leg symptoms. Distances achieved in the 6-minute walk were 1,130, 1,362, and 1,539 feet for Groups 1, 2, and 3, respectively, adjusting for age, gender, and race (P < .001). The degree of difficulty walking due to leg symptoms as reported on the WIQ was comparable between Groups 2 and 3 and significantly greater in Group 1 than Group 2. In multiple logistic regression analysis including Groups 2 and 3, current cigarette smoking was associated independently with unrecognized PAD (odds ratio [OR], 6.82; 95% confidence interval [95% CI], 1.55 to 29.93). Aspirin therapy was nearly independently associated with absence of PAD (OR, 0.37; 95% CI, 0.12 to 1.12). CONCLUSION Unrecognized PAD is common among men and women aged 55 years and older in GIM practice and is associated with impaired lower extremity functioning. Ankle brachial index screening may be necessary to diagnose unrecognized PAD in a GIM

SPIDIA-DNA: An External Quality Assessment for the pre-analytical phase of blood samples used for DNA-based analyses

Czech Academy of Sciences Publication Activity Database

Malentacchi, F.; Pazzagli, M.; Simi, L.; Orlando, C.; Wyrich, R.; Hartmann, C.C.; Verderio, P.; Pizzamiglio, S.; Ciniselli, C.M.; Tichopád, Aleš; Kubista, Mikael; Gelmini, S.

-, č. 424 (2013), s. 274-286 ISSN 0009-8981 Institutional research plan: CEZ:AV0Z50520701 Keywords : Pre-analytical phase * DNA quality * Blood samples Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.764, year: 2013

Does laboratory automation for the preanalytical phase improve data quality?

Science.gov (United States)

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Montagnana, Martina; Brocco, Giorgio; Voi, Monica; Picheth, Geraldo; Guidi, Gian Cesare

2013-10-01

Our aim was to evaluate whether automation for the preanalytical phase improves data quality. Blood from 100 volunteers was collected into two vacuum tubes. One sample from each volunteer was respectively assigned to (G1) traditional processing, starting with centrifugation at 1200 g for 10 min, and (G2) the MODULAR PRE-ANALYTICALS EVO-MPA system. The routine clinical chemistry tests were performed in duplicate on the same instrument Cobas 6000 module. G1 samples were uncapped manually and immediately placed into the instrument. G2 samples were directly fed from the MPA system to the instrument without further staff intervention. At the end, (1) the G1 samples were stored for 6 h at 4 °C as prescribed in our accredited laboratory and (2) the G2 samples were stored for 6 h in the MPA output buffer. Results from G1 and G2, before and after storage, were compared. Significant increases were observed in G1 compared with G2 samples as follows: (1) before storage for alkaline phosphatase (ALP), lactate dehydrogenase (LDH), phosphate (P), magnesium (MG), iron (FE), and hemolysis index and (2) after storage for total cholesterol (COL), triglycerides (TG), total protein (TP), albumin (ALB), blood urea nitrogen (BUN), creatinine (CRE), uric acid (UA), ALP, pancreatic amylase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), g-glutamyltransferase (GGT), LDH, creatine kinase (CK), calcium (CA), FE, sodium (NA), potassium (K), and hemolysis index. Moreover, significant increases were observed in (3) G1-after versus G1-before storage samples for COL, high-density lipoprotein cholesterol, TG, TP, ALB, BUN, CRE, UA, AST, ALT, GGT, LDH, P, CA, MG, FE, NA, K, and hemolysis index and (4) G2-after versus G2-before storage only for BUN, AST, LDH, P, and CA. In conclusion, our results show that the MPA system improves the quality of laboratory testing.

Circulating VEGF as a biological marker in patients with rheumatoid arthritis? Preanalytical and biological variability in healthy persons and in patients

DEFF Research Database (Denmark)

Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine

2008-01-01

/ml (range: non-detectable to 352); serum: 328 pg/ml (53-1791)) were independent of gender and age. Short- and long-term biologic variability included diurnal variation (sampling should take place after 7 AM) and impact of exercise (increased VEGF immediately after bicycling normalised within 1 hour......BACKGROUND: Soluble vascular endothelial growth factor (VEGF) is a promising biomarker in monitoring rheumatoid arthritis (RA), but studies of pre-analytical and biologic variability are few. METHODS: VEGF was measured by ELISA methods in serum and plasma from healthy persons and RA patients. Pre......). CONCLUSIONS: Pre-analytical factors and biologic variability including diurnal variation and impact of exercise should be accounted for in future studies that include circulating VEGF as a biological marker....

SPIDIA-RNA: First external quality assessment for the pre-analytical phase of blood samples used for RNA based analyses

Czech Academy of Sciences Publication Activity Database

Pazzagli, M.; Malentacchi, F.; Simi, L.; Wyrich, R.; Guenther, K.; Hartmann, C.; Verderio, P.; Pizzamiglio, S.; Ciniselli, C.M.; Tichopád, Aleš; Kubista, Mikael; Gelmini, S.

2013-01-01

Roč. 59, č. 1 (2013), s. 20-31 ISSN 1046-2023 Institutional research plan: CEZ:AV0Z50520701 Keywords : Pre-analytical phase * RNA quality * Blood samples Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.221, year: 2013

Analysis of Pre-Analytic Factors Affecting the Success of Clinical Next-Generation Sequencing of Solid Organ Malignancies

International Nuclear Information System (INIS)

Chen, Hui; Luthra, Rajyalakshmi; Goswami, Rashmi S.; Singh, Rajesh R.; Roy-Chowdhuri, Sinchita

2015-01-01

Application of next-generation sequencing (NGS) technology to routine clinical practice has enabled characterization of personalized cancer genomes to identify patients likely to have a response to targeted therapy. The proper selection of tumor sample for downstream NGS based mutational analysis is critical to generate accurate results and to guide therapeutic intervention. However, multiple pre-analytic factors come into play in determining the success of NGS testing. In this review, we discuss pre-analytic requirements for AmpliSeq PCR-based sequencing using Ion Torrent Personal Genome Machine (PGM) (Life Technologies), a NGS sequencing platform that is often used by clinical laboratories for sequencing solid tumors because of its low input DNA requirement from formalin fixed and paraffin embedded tissue. The success of NGS mutational analysis is affected not only by the input DNA quantity but also by several other factors, including the specimen type, the DNA quality, and the tumor cellularity. Here, we review tissue requirements for solid tumor NGS based mutational analysis, including procedure types, tissue types, tumor volume and fraction, decalcification, and treatment effects

Analysis of Pre-Analytic Factors Affecting the Success of Clinical Next-Generation Sequencing of Solid Organ Malignancies

Energy Technology Data Exchange (ETDEWEB)

Chen, Hui [Department of Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (United States); Luthra, Rajyalakshmi, E-mail: rluthra@mdanderson.org; Goswami, Rashmi S.; Singh, Rajesh R. [Department of Hematopathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (United States); Roy-Chowdhuri, Sinchita [Department of Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (United States)

2015-08-28

Application of next-generation sequencing (NGS) technology to routine clinical practice has enabled characterization of personalized cancer genomes to identify patients likely to have a response to targeted therapy. The proper selection of tumor sample for downstream NGS based mutational analysis is critical to generate accurate results and to guide therapeutic intervention. However, multiple pre-analytic factors come into play in determining the success of NGS testing. In this review, we discuss pre-analytic requirements for AmpliSeq PCR-based sequencing using Ion Torrent Personal Genome Machine (PGM) (Life Technologies), a NGS sequencing platform that is often used by clinical laboratories for sequencing solid tumors because of its low input DNA requirement from formalin fixed and paraffin embedded tissue. The success of NGS mutational analysis is affected not only by the input DNA quantity but also by several other factors, including the specimen type, the DNA quality, and the tumor cellularity. Here, we review tissue requirements for solid tumor NGS based mutational analysis, including procedure types, tissue types, tumor volume and fraction, decalcification, and treatment effects.

Analysis of Pre-Analytic Factors Affecting the Success of Clinical Next-Generation Sequencing of Solid Organ Malignancies

Directory of Open Access Journals (Sweden)

Hui Chen

2015-08-01

Full Text Available Application of next-generation sequencing (NGS technology to routine clinical practice has enabled characterization of personalized cancer genomes to identify patients likely to have a response to targeted therapy. The proper selection of tumor sample for downstream NGS based mutational analysis is critical to generate accurate results and to guide therapeutic intervention. However, multiple pre-analytic factors come into play in determining the success of NGS testing. In this review, we discuss pre-analytic requirements for AmpliSeq PCR-based sequencing using Ion Torrent Personal Genome Machine (PGM (Life Technologies, a NGS sequencing platform that is often used by clinical laboratories for sequencing solid tumors because of its low input DNA requirement from formalin fixed and paraffin embedded tissue. The success of NGS mutational analysis is affected not only by the input DNA quantity but also by several other factors, including the specimen type, the DNA quality, and the tumor cellularity. Here, we review tissue requirements for solid tumor NGS based mutational analysis, including procedure types, tissue types, tumor volume and fraction, decalcification, and treatment effects.

Standard operating procedures for pre-analytical handling of blood and urine for metabolomic studies and biobanks

Energy Technology Data Exchange (ETDEWEB)

Bernini, Patrizia; Bertini, Ivano, E-mail: bertini@cerm.unifi.it; Luchinat, Claudio [University of Florence, Magnetic Resonance Center (CERM) (Italy); Nincheri, Paola; Staderini, Samuele [FiorGen Foundation (Italy); Turano, Paola [University of Florence, Magnetic Resonance Center (CERM) (Italy)

2011-04-15

{sup 1}H NMR metabolic profiling of urine, serum and plasma has been used to monitor the impact of the pre-analytical steps on the sample quality and stability in order to propose standard operating procedures (SOPs) for deposition in biobanks. We analyzed the quality of serum and plasma samples as a function of the elapsed time (t = 0-4 h) between blood collection and processing and of the time from processing to freezing (up to 24 h). The stability of the urine metabolic profile over time (up to 24 h) at various storage temperatures was monitored as a function of the different pre-analytical treatments like pre-storage centrifugation, filtration, and addition of the bacteriostatic preservative sodium azide. Appreciable changes in the profiles, reflecting changes in the concentration of a number of metabolites, were detected and discussed in terms of chemical and enzymatic reactions for both blood and urine samples. Appropriate procedures for blood derivatives collection and urine preservation/storage that allow maintaining as much as possible the original metabolic profile of the fresh samples emerge, and are proposed as SOPs for biobanking.

Standard operating procedures for pre-analytical handling of blood and urine for metabolomic studies and biobanks.

Science.gov (United States)

Bernini, Patrizia; Bertini, Ivano; Luchinat, Claudio; Nincheri, Paola; Staderini, Samuele; Turano, Paola

2011-04-01

(1)H NMR metabolic profiling of urine, serum and plasma has been used to monitor the impact of the pre-analytical steps on the sample quality and stability in order to propose standard operating procedures (SOPs) for deposition in biobanks. We analyzed the quality of serum and plasma samples as a function of the elapsed time (t = 0-4 h) between blood collection and processing and of the time from processing to freezing (up to 24 h). The stability of the urine metabolic profile over time (up to 24 h) at various storage temperatures was monitored as a function of the different pre-analytical treatments like pre-storage centrifugation, filtration, and addition of the bacteriostatic preservative sodium azide. Appreciable changes in the profiles, reflecting changes in the concentration of a number of metabolites, were detected and discussed in terms of chemical and enzymatic reactions for both blood and urine samples. Appropriate procedures for blood derivatives collection and urine preservation/storage that allow maintaining as much as possible the original metabolic profile of the fresh samples emerge, and are proposed as SOPs for biobanking.

Standard operating procedures for pre-analytical handling of blood and urine for metabolomic studies and biobanks

International Nuclear Information System (INIS)

Bernini, Patrizia; Bertini, Ivano; Luchinat, Claudio; Nincheri, Paola; Staderini, Samuele; Turano, Paola

2011-01-01

1 H NMR metabolic profiling of urine, serum and plasma has been used to monitor the impact of the pre-analytical steps on the sample quality and stability in order to propose standard operating procedures (SOPs) for deposition in biobanks. We analyzed the quality of serum and plasma samples as a function of the elapsed time (t = 0−4 h) between blood collection and processing and of the time from processing to freezing (up to 24 h). The stability of the urine metabolic profile over time (up to 24 h) at various storage temperatures was monitored as a function of the different pre-analytical treatments like pre-storage centrifugation, filtration, and addition of the bacteriostatic preservative sodium azide. Appreciable changes in the profiles, reflecting changes in the concentration of a number of metabolites, were detected and discussed in terms of chemical and enzymatic reactions for both blood and urine samples. Appropriate procedures for blood derivatives collection and urine preservation/storage that allow maintaining as much as possible the original metabolic profile of the fresh samples emerge, and are proposed as SOPs for biobanking.

Prevalence of electrocardiographic unrecognized myocardial infarction and its association with mortality

NARCIS (Netherlands)

van der Ende, M. Yldau; Hartman, Minke H. T.; Schurer, Remco A. J.; van der Werf, Hindrik W.; Lipsic, Erik; Snieder, Harold; van der Harst, Pim

2017-01-01

Background: Identifying unrecognizedmyocardial infarction (MI) is important for secondary prevention. The aim of this study is to determine the prevalence and correlates of unrecognizedMI and the associationwithmortality in the general population. Methods: All participants >= 18 years participating

Impact of pre-analytical factors on the proteomic analysis of formalin-fixed paraffin-embedded tissue.

Science.gov (United States)

Thompson, Seonaid M; Craven, Rachel A; Nirmalan, Niroshini J; Harnden, Patricia; Selby, Peter J; Banks, Rosamonde E

2013-04-01

Formalin-fixed paraffin-embedded (FFPE) tissue samples represent a tremendous potential resource for biomarker discovery, with large numbers of samples in hospital pathology departments and links to clinical information. However, the cross-linking of proteins and nucleic acids by formalin fixation has hampered analysis and proteomic studies have been restricted to using frozen tissue, which is more limited in availability as it needs to be collected specifically for research. This means that rare disease subtypes cannot be studied easily. Recently, improved extraction techniques have enabled analysis of FFPE tissue by a number of proteomic techniques. As with all clinical samples, pre-analytical factors are likely to impact on the results obtained, although overlooked in many studies. The aim of this review is to discuss the various pre-analytical factors, which include warm and cold ischaemic time, size of sample, fixation duration and temperature, tissue processing conditions, length of storage of archival tissue and storage conditions, and to review the studies that have considered these factors in more detail. In those areas where investigations are few or non-existent, illustrative examples of the possible importance of specific factors have been drawn from studies using frozen tissue or from immunohistochemical studies of FFPE tissue. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimised Pre-Analytical Methods Improve KRAS Mutation Detection in Circulating Tumour DNA (ctDNA) from Patients with Non-Small Cell Lung Cancer (NSCLC)

Science.gov (United States)

Sherwood, James L.; Corcoran, Claire; Brown, Helen; Sharpe, Alan D.; Musilova, Milena; Kohlmann, Alexander

2016-01-01

Introduction Non-invasive mutation testing using circulating tumour DNA (ctDNA) is an attractive premise. This could enable patients without available tumour sample to access more treatment options. Materials & Methods Peripheral blood and matched tumours were analysed from 45 NSCLC patients. We investigated the impact of pre-analytical variables on DNA yield and/or KRAS mutation detection: sample collection tube type, incubation time, centrifugation steps, plasma input volume and DNA extraction kits. Results 2 hr incubation time and double plasma centrifugation (2000 x g) reduced overall DNA yield resulting in lowered levels of contaminating genomic DNA (gDNA). Reduced “contamination” and increased KRAS mutation detection was observed using cell-free DNA Blood Collection Tubes (cfDNA BCT) (Streck), after 72 hrs following blood draw compared to EDTA tubes. Plasma input volume and use of different DNA extraction kits impacted DNA yield. Conclusion This study demonstrated that successful ctDNA recovery for mutation detection in NSCLC is dependent on pre-analytical steps. Development of standardised methods for the detection of KRAS mutations from ctDNA specimens is recommended to minimise the impact of pre-analytical steps on mutation detection rates. Where rapid sample processing is not possible the use of cfDNA BCT tubes would be advantageous. PMID:26918901

Optimised Pre-Analytical Methods Improve KRAS Mutation Detection in Circulating Tumour DNA (ctDNA from Patients with Non-Small Cell Lung Cancer (NSCLC.

Directory of Open Access Journals (Sweden)

James L Sherwood

Full Text Available Non-invasive mutation testing using circulating tumour DNA (ctDNA is an attractive premise. This could enable patients without available tumour sample to access more treatment options.Peripheral blood and matched tumours were analysed from 45 NSCLC patients. We investigated the impact of pre-analytical variables on DNA yield and/or KRAS mutation detection: sample collection tube type, incubation time, centrifugation steps, plasma input volume and DNA extraction kits.2 hr incubation time and double plasma centrifugation (2000 x g reduced overall DNA yield resulting in lowered levels of contaminating genomic DNA (gDNA. Reduced "contamination" and increased KRAS mutation detection was observed using cell-free DNA Blood Collection Tubes (cfDNA BCT (Streck, after 72 hrs following blood draw compared to EDTA tubes. Plasma input volume and use of different DNA extraction kits impacted DNA yield.This study demonstrated that successful ctDNA recovery for mutation detection in NSCLC is dependent on pre-analytical steps. Development of standardised methods for the detection of KRAS mutations from ctDNA specimens is recommended to minimise the impact of pre-analytical steps on mutation detection rates. Where rapid sample processing is not possible the use of cfDNA BCT tubes would be advantageous.

Pre-analytic evaluation of volumetric absorptive microsampling and integration in a mass spectrometry-based metabolomics workflow.

Science.gov (United States)

Volani, Chiara; Caprioli, Giulia; Calderisi, Giovanni; Sigurdsson, Baldur B; Rainer, Johannes; Gentilini, Ivo; Hicks, Andrew A; Pramstaller, Peter P; Weiss, Guenter; Smarason, Sigurdur V; Paglia, Giuseppe

2017-10-01

Volumetric absorptive microsampling (VAMS) is a novel approach that allows single-drop (10 μL) blood collection. Integration of VAMS with mass spectrometry (MS)-based untargeted metabolomics is an attractive solution for both human and animal studies. However, to boost the use of VAMS in metabolomics, key pre-analytical questions need to be addressed. Therefore, in this work, we integrated VAMS in a MS-based untargeted metabolomics workflow and investigated pre-analytical strategies such as sample extraction procedures and metabolome stability at different storage conditions. We first evaluated the best extraction procedure for the polar metabolome and found that the highest number and amount of metabolites were recovered upon extraction with acetonitrile/water (70:30). In contrast, basic conditions (pH 9) resulted in divergent metabolite profiles mainly resulting from the extraction of intracellular metabolites originating from red blood cells. In addition, the prolonged storage of blood samples at room temperature caused significant changes in metabolome composition, but once the VAMS devices were stored at - 80 °C, the metabolome remained stable for up to 6 months. The time used for drying the sample did also affect the metabolome. In fact, some metabolites were rapidly degraded or accumulated in the sample during the first 48 h at room temperature, indicating that a longer drying step will significantly change the concentration in the sample. Graphical abstract Volumetric absorptive microsampling (VAMS) is a novel technology that allows single-drop blood collection and, in combination with mass spectrometry (MS)-based untargeted metabolomics, represents an attractive solution for both human and animal studies. In this work, we integrated VAMS in a MS-based untargeted metabolomics workflow and investigated pre-analytical strategies such as sample extraction procedures and metabolome stability at different storage conditions. The latter revealed that

Influence of common preanalytical variations on the metabolic profile of serum samples in biobanks

International Nuclear Information System (INIS)

Fliniaux, Ophélie; Gaillard, Gwenaelle; Lion, Antoine; Cailleu, Dominique; Mesnard, François; Betsou, Fotini

2011-01-01

A blood pre-centrifugation delay of 24 h at room temperature influenced the proton NMR spectroscopic profiles of human serum. A blood pre-centrifugation delay of 24 h at 4°C did not influence the spectroscopic profile as compared with 4 h delays at either room temperature or 4°C. Five or ten serum freeze–thaw cycles also influenced the proton NMR spectroscopic profiles. Certain common in vitro preanalytical variations occurring in biobanks may impact the metabolic profile of human serum.

Use of CTX-I and PINP as bone turnover markers: National Bone Health Alliance recommendations to standardize sample handling and patient preparation to reduce pre-analytical variability.

Science.gov (United States)

Szulc, P; Naylor, K; Hoyle, N R; Eastell, R; Leary, E T

2017-09-01

The National Bone Health Alliance (NBHA) recommends standardized sample handling and patient preparation for C-terminal telopeptide of type I collagen (CTX-I) and N-terminal propeptide of type I procollagen (PINP) measurements to reduce pre-analytical variability. Controllable and uncontrollable patient-related factors are reviewed to facilitate interpretation and minimize pre-analytical variability. The IOF and the International Federation of Clinical Chemistry (IFCC) Bone Marker Standards Working Group have identified PINP and CTX-I in blood to be the reference markers of bone turnover for the fracture risk prediction and monitoring of osteoporosis treatment. Although used in clinical research for many years, bone turnover markers (BTM) have not been widely adopted in clinical practice primarily due to their poor within-subject and between-lab reproducibility. The NBHA Bone Turnover Marker Project team aim to reduce pre-analytical variability of CTX-I and PINP measurements through standardized sample handling and patient preparation. Recommendations for sample handling and patient preparations were made based on review of available publications and pragmatic considerations to reduce pre-analytical variability. Controllable and un-controllable patient-related factors were reviewed to facilitate interpretation and sample collection. Samples for CTX-I must be collected consistently in the morning hours in the fasted state. EDTA plasma is preferred for CTX-I for its greater sample stability. Sample collection conditions for PINP are less critical as PINP has minimal circadian variability and is not affected by food intake. Sample stability limits should be observed. The uncontrollable aspects (age, sex, pregnancy, immobility, recent fracture, co-morbidities, anti-osteoporotic drugs, other medications) should be considered in BTM interpretation. Adopting standardized sample handling and patient preparation procedures will significantly reduce controllable pre-analytical

Pre-analytical and analytical variation of drug determination in segmented hair using ultra-performance liquid chromatography-tandem mass spectrometry

DEFF Research Database (Denmark)

Nielsen, Marie Katrine Klose; Johansen, Sys Stybe; Linnet, Kristian

2014-01-01

variation was estimated to be less than 15% for almost all compounds. The method was successfully applied to 25 segmented hair specimens from deceased drug addicts showing a broad pattern of poly-drug use. The pre-analytical sampling variation was estimated from the genuine duplicate measurements of two...

Clinically unrecognized miliary tuberculosis: an autopsy study.

Science.gov (United States)

Savic, Ivana; Trifunovic-Skodric, Vesna; Mitrovic, Dragan

2016-01-01

Miliary tuberculosis (TB) usually presents with atypical clinical manifestations; thus it is often recognized only at autopsy. Our objectives were to study the frequency of MT diagnosed at autopsy and determine clinical diagnoses that masked TB, as well as causes of death and comorbidities. Retrospective study of all autopsies performed between 2008 and 2014. Institute of Pathology, Belgrade, Serbia. in subjects where autopsy showed the presence of MT that was not recognized clinically, we recorded the clinical diagnoses (presumed causes of death) as reported in autopsy request forms, as well as actual cause of death and comorbidities as determined at autopsy. Clinically unrecognized MT. The total number of autopsies in this period was 6206. thirty-five individuals showed clinically unrecognized MT (0.56% of all autopsies, age: 62.2 [17.2] years, M:F=2:3). Common clinical diagnoses masking pulmonary MT were exacerbation of COPD (25%) and pulmonary thromboembolism (25%), with common radiological presentation of diffuse pulmonary infiltrates (56.3%). Dominant clinical diagnoses in patients with generalized MT were adult respiratory distress syndrome, sepsis, gastrointestinal bleeding and meningoencephalitis. Disseminated MT was often associated with secondary anemia or thrombocytopenia (15.8%) and recent surgery (15.8%). Frequent comorbidities included chronic renal failure and malignancies, whereas MT was a dominant cause of death. Greater awareness of MT is needed to improve recognition in clinical settings. In particular, MT should be considered in patients with atypical clinical presentation and diffuse pulmonary infiltrates on chest X-ray, particularly if they have chronic renal failure, malignancy, hematological disorders or a history of recent surgery. None.

Pre-analytical sample quality: metabolite ratios as an intrinsic marker for prolonged room temperature exposure of serum samples.

Directory of Open Access Journals (Sweden)

Gabriele Anton

Full Text Available Advances in the "omics" field bring about the need for a high number of good quality samples. Many omics studies take advantage of biobanked samples to meet this need. Most of the laboratory errors occur in the pre-analytical phase. Therefore evidence-based standard operating procedures for the pre-analytical phase as well as markers to distinguish between 'good' and 'bad' quality samples taking into account the desired downstream analysis are urgently needed. We studied concentration changes of metabolites in serum samples due to pre-storage handling conditions as well as due to repeated freeze-thaw cycles. We collected fasting serum samples and subjected aliquots to up to four freeze-thaw cycles and to pre-storage handling delays of 12, 24 and 36 hours at room temperature (RT and on wet and dry ice. For each treated aliquot, we quantified 127 metabolites through a targeted metabolomics approach. We found a clear signature of degradation in samples kept at RT. Storage on wet ice led to less pronounced concentration changes. 24 metabolites showed significant concentration changes at RT. In 22 of these, changes were already visible after only 12 hours of storage delay. Especially pronounced were increases in lysophosphatidylcholines and decreases in phosphatidylcholines. We showed that the ratio between the concentrations of these molecule classes could serve as a measure to distinguish between 'good' and 'bad' quality samples in our study. In contrast, we found quite stable metabolite concentrations during up to four freeze-thaw cycles. We concluded that pre-analytical RT handling of serum samples should be strictly avoided and serum samples should always be handled on wet ice or in cooling devices after centrifugation. Moreover, serum samples should be frozen at or below -80°C as soon as possible after centrifugation.

Pre-Analytical Components of Risk in Four Branches of Clinical Laboratory in Romania--Prospective Study.

Science.gov (United States)

David, Remona E; Dobreanu, Minodora

2016-01-01

Development of quality measurement principles is a strategic point for each clinical laboratory. Preexamination process is the most critical and the most difficult to be managed. The aim of this study is to identify, quantify, and monitor the nonconformities of the pre-analytical process using quality indicators that can affect the patient's health safety in four different locations of a Romanian private clinical laboratory. The study group consisted of all the analysis requests received by the departments of biochemistry, hematology, and coagulation from January through March 2015. In order to collect the pre-analytical nonconformities, we created a "Risk Budget", using the entries from the "Evidence notebook--non-conform samples" from the above mentioned departments. The laboratory established the quality indicators by means of the risk management technique in order to identify and control the sources of errors, FMEA (Failure Modes and Effects Analyses), which had been implemented and monitored for its purposes and special needs. For the assessment of the control level over the processes, the results were transformed on the Six Sigma scale, using the Westgard calculation method and being obtained in this way the frequency with which an error may occur. (https://www.westgard. com/six-sigma-calculators.htm). The obtained results prove that the quantification and monitoring of the indicators can be a control instrument for the pre-analytic activities. The calculation of the Six Sigma value adds extra information to the study because it allows the detection of the processes which need improvement (Sigma value higher than 4 represents a well controlled process). The highest rates were observed for the hemolyzed and the lipemic samples, in the department of biochemistry and hemolyzed, insufficient sample volume, or clotted samples for the department of hematology and coagulation. Significant statistical differences between laboratories participating in the study have

Influence of common preanalytical variations on the metabolic profile of serum samples in biobanks

Energy Technology Data Exchange (ETDEWEB)

Fliniaux, Ophelie [University of Picardie Jules Verne, Laboratoire de Phytotechnologie EA 3900-BioPI (France); Gaillard, Gwenaelle [Biobanque de Picardie (France); Lion, Antoine [University of Picardie Jules Verne, Laboratoire de Phytotechnologie EA 3900-BioPI (France); Cailleu, Dominique [Batiment Serres-Transfert, rue de Mai/rue Dallery, Plateforme Analytique (France); Mesnard, Francois, E-mail: francois.mesnard@u-picardie.fr [University of Picardie Jules Verne, Laboratoire de Phytotechnologie EA 3900-BioPI (France); Betsou, Fotini [Integrated Biobank of Luxembourg (Luxembourg)

2011-12-15

A blood pre-centrifugation delay of 24 h at room temperature influenced the proton NMR spectroscopic profiles of human serum. A blood pre-centrifugation delay of 24 h at 4 Degree-Sign C did not influence the spectroscopic profile as compared with 4 h delays at either room temperature or 4 Degree-Sign C. Five or ten serum freeze-thaw cycles also influenced the proton NMR spectroscopic profiles. Certain common in vitro preanalytical variations occurring in biobanks may impact the metabolic profile of human serum.

Control of (pre-analytical aspects in immunoassay measurements of metabolic hormones in rodents

Directory of Open Access Journals (Sweden)

Maximilian Bielohuby

2018-04-01

Full Text Available The measurement of circulating hormones by immunoassay remains a cornerstone in preclinical endocrine research. For scientists conducting and interpreting immunoassay measurements of rodent samples, the paramount aim usually is to obtain reliable and meaningful measurement data in order to draw conclusions on biological processes. However, the biological variability between samples is not the only variable affecting the readout of an immunoassay measurement and a considerable amount of unwanted or unintended variability can be quickly introduced during the pre-analytical and analytical phase. This review aims to increase the awareness for the factors ‘pre-analytical’ and ‘analytical’ variability particularly in the context of immunoassay measurement of circulating metabolic hormones in rodent samples. In addition, guidance is provided how to gain control over these variables and how to avoid common pitfalls associated with sample collection, processing, storage and measurement. Furthermore, recommendations are given on how to perform a basic validation of novel single and multiplex immunoassays for the measurement of metabolic hormones in rodents. Finally, practical examples from immunoassay measurements of plasma insulin in mice address the factors ‘sampling site and inhalation anesthesia’ as frequent sources of introducing an unwanted variability during the pre-analytical phase. The knowledge about the influence of both types of variability on the immunoassay measurement of circulating hormones as well as strategies to control these variables are crucial, on the one hand, for planning and realization of metabolic rodent studies and, on the other hand, for the generation and interpretation of meaningful immunoassay data from rodent samples.

Statistical uncertainties and unrecognized relationships

International Nuclear Information System (INIS)

Rankin, J.P.

1985-01-01

Hidden relationships in specific designs directly contribute to inaccuracies in reliability assessments. Uncertainty factors at the system level may sometimes be applied in attempts to compensate for the impact of such unrecognized relationships. Often uncertainty bands are used to relegate unknowns to a miscellaneous category of low-probability occurrences. However, experience and modern analytical methods indicate that perhaps the dominant, most probable and significant events are sometimes overlooked in statistical reliability assurances. The author discusses the utility of two unique methods of identifying the otherwise often unforeseeable system interdependencies for statistical evaluations. These methods are sneak circuit analysis and a checklist form of common cause failure analysis. Unless these techniques (or a suitable equivalent) are also employed along with the more widely-known assurance tools, high reliability of complex systems may not be adequately assured. This concern is indicated by specific illustrations. 8 references, 5 figures

Recommendations to standardize preanalytical confounding factors in Alzheimer's and Parkinson's disease cerebrospinal fluid biomarkers

DEFF Research Database (Denmark)

del Campo, Marta; Mollenhauer, Brit; Bertolotto, Antonio

2012-01-01

Early diagnosis of neurodegenerative disorders such as Alzheimer's (AD) or Parkinson's disease (PD) is needed to slow down or halt the disease at the earliest stage. Cerebrospinal fluid (CSF) biomarkers can be a good tool for early diagnosis. However, their use in clinical practice is challenging...... the need to establish standardized operating procedures. Here, we merge two previous consensus guidelines for preanalytical confounding factors in order to achieve one exhaustive guideline updated with new evidence for Aβ42, total tau and phosphorylated tau, and α-synuclein. The proposed standardized...

Pre-analytical and biological variability in circulating interleukin 6 in healthy subjects and patients with rheumatoid arthritis

DEFF Research Database (Denmark)

Knudsen, Lene S; Christensen, Ib J; Lottenburger, Tine

2008-01-01

in serum IL-6 over a 3-year period (14%, p=0.33). Exercise (cycling) increased serum IL-6 in healthy subjects but not in RA patients. In conclusion, circulating IL-6 is stable regarding sample handling and shows little variation over time. Changes in IL-6 concentrations >60% (2 times the biological...... variation) are likely to reflect changes in disease activity and not only pre-analytical or normal biological variability....

Technical evaluation of the novel preanalytical module on instrumentation laboratory ACL TOP: advancing automation in hemostasis testing.

Science.gov (United States)

Lippi, Giuseppe; Ippolito, Luigi; Favaloro, Emmanuel J

2013-10-01

Automation in hemostasis testing is entering an exciting and unprecedented phase. This study was planned to assess the performance of the new preanalytical module on the hemostasis testing system Instrumentation Laboratory ACL TOP. The evaluation included interference studies to define reliable thresholds for rejecting samples with significant concentrations of interfering substances; within-run imprecision studies of plasma indices on four different interference degrees for each index; comparison studies with reference measures of hemolysis index, bilirubin, and triglycerides on clinical chemistry analyzers; and calculation of turnaround time with and without automatic performance of preanalytical check. The upper limits for sample rejection according to our interference studies were 3.6 g/L for hemoglobin, 13.6 mg/dL for bilirubin, and 1454 mg/dL for triglycerides. We found optimal precision for all indices (0.6% to 3.1% at clinically relevant thresholds) and highly significant correlations with reference measures on clinical chemistry analyzers (from 0.985 to 0.998). The limited increase of turnaround time (i.e., +3% and +5% with or without cap-piercing), coupled with no adjunctive costs over performance of normal coagulation assays, contribute to make the automatic check of plasma indices on ACL TOP a reliable and practical approach for improving testing quality and safeguarding patient safety.

Breast Carcinoma With Unrecognized Neuroendocrine Differentiation Metastasizing to the Pancreas

DEFF Research Database (Denmark)

Christensen, Lene Svendstrup; Mortensen, Michael Bau; Detlefsen, Sönke

2016-01-01

, a second panel revealed positivity for estrogen receptors and GATA3. On review of the lumpectomy specimen, a significant neuroendocrine component was found, leading to the final diagnosis of breast carcinoma with neuroendocrine features metastasizing to the pancreas. Neuroendocrine markers...... are not routinely analyzed in breast tumors. Hence, metastases from breast carcinomas with unrecognized neuroendocrine features may lead to false diagnoses of primary neuroendocrine tumors at different metastatic sites, such as the pancreas....

Pre-analytical and post-analytical evaluation in the era of molecular diagnosis of sexually transmitted diseases: cellularity control and internal control

Directory of Open Access Journals (Sweden)

Loria Bianchi

2014-06-01

Full Text Available Background. Increase of molecular tests performed on DNA extracted from various biological materials should not be carried out without an adequate standardization of the pre-analytical and post-analytical phase. Materials and Methods. Aim of this study was to evaluate the role of internal control (IC to standardize pre-analytical phase and the role of cellularity control (CC in the suitability evaluation of biological matrices, and their influence on false negative results. 120 cervical swabs (CS were pre-treated and extracted following 3 different protocols. Extraction performance was evaluated by amplification of: IC, added in each mix extraction; human gene HPRT1 (CC with RT-PCR to quantify sample cellularity; L1 region of HPV with SPF10 primers. 135 urine, 135 urethral swabs, 553 CS and 332 ThinPrep swabs (TP were tested for C. trachomatis (CT and U. parvum (UP with RT-PCR and for HPV by endpoint-PCR. Samples were also tested for cellularity. Results. Extraction protocol with highest average cellularity (Ac/sample showed lowest number of samples with inhibitors; highest HPV positivity was achieved by protocol with greatest Ac/PCR. CS and TP under 300.000 cells/sample showed a significant decrease of UP (P<0.01 and HPV (P<0.005 positivity. Female urine under 40.000 cells/mL were inadequate to detect UP (P<0.05. Conclusions. Our data show that IC and CC allow optimization of pre-analytical phase, with an increase of analytical quality. Cellularity/sample allows better sample adequacy evaluation, crucial to avoid false negative results, while cellularity/PCR allows better optimization of PCR amplification. Further data are required to define the optimal cut-off for result normalization.

An unrecognized foreign body retained in the calcaneus

Energy Technology Data Exchange (ETDEWEB)

Lee, Ro Woon; Choi, Soo Jung; Hwang, Jae Kwang; Ahn, Jae Hong; Kang, Chae Hoon; Shin, Dong Rock [Gangneung Asan Hospital, College of Medicine, University of Ulsan, Gangneung (Korea, Republic of)

2017-06-15

We describe a case of an unrecognized foreign body retained in the calcaneus. The patient denied any history of trauma. The skin overlying the calcaneus was intact with no local signs of inflammation. The retained foreign body was not observed on the radiograph of the calcaneus. Magnetic Resonance Imaging showed a tubular low signal intensity lesion in the calcaneal body, surrounded by strongly enhanced soft tissue and bone marrow edema caused by a foreign body reaction. A foreign body retained in the calcaneus was suspected on the basis of these findings. Surgical exploration and curettage was performed, and a rod shaped wooden fragment was found.

Thyroglobulin assay in fluids from lymph node fine needle-aspiration washout: influence of pre-analytical conditions.

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Casson, Florence Boux de; Moal, Valérie; Gauchez, Anne-Sophie; Moineau, Marie-Pierre; Sault, Corinne; Schlageter, Marie-Hélène; Massart, Catherine

2017-04-01

The aim of this study was to evaluate the pre-analytical factors contributing to uncertainty in thyroglobulin measurement in fluids from fine-needle aspiration (FNA) washout of cervical lymph nodes. We studied pre-analytical stability, in different conditions, of 41 samples prepared with concentrated solutions of thyroglobulin (FNA washout or certified standard) diluted in physiological saline solution or buffer containing 6% albumin. In this buffer, over time, no changes in thyroglobulin concentrations were observed in all storage conditions tested. In albumin free saline solution, thyroglobulin recovery rates depended on initial sample concentrations and on modalities of their conservation (in conventional storage tubes, recovery mean was 56% after 3 hours-storage at room temperature and 19% after 24 hours-storage for concentrations ranged from 2 to 183 μg/L; recovery was 95%, after 3 hours or 24 hours-storage at room temperature, for a concentration of 5,656 μg/L). We show here that these results are due to non-specific adsorption of thyroglobulin in storage tubes, which depends on sample protein concentrations. We also show that possible contamination of fluids from FNA washout by plasma proteins do not always adequately prevent this adsorption. In conclusion, non-specific adsorption in storage tubes strongly contributes to uncertainty in thyroglobulin measurement in physiological saline solution. It is therefore recommended, for FNA washout, to use a buffer containing proteins provided by the laboratory.

[Pre-analytical stability before centrifugation of 7 biochemical analytes in whole blood].

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Perrier-Cornet, Andreas; Moineau, Marie-Pierre; Narbonne, Valérie; Plee-Gautier, Emmanuelle; Le Saos, Fabienne; Carre, Jean-Luc

2015-01-01

The pre-analytical stability of 7 biochemical parameters (parathyroid hormone -PTH-, vitamins A, C E and D, 1,25-dihydroxyvitamin D and insulin) at +4 °C, was studied on whole blood samples before centrifugation. The impact of freezing at -20°C was also analyzed/performed for PTH and vitamin D. The differences in the results of assays for whole blood samples, being kept for different times between sampling time and analysis, from 9 healthy adults, were compaired by using a Student t test. The 7 analytes investigated remained stable up to 4 hours at +4°C in whole blood. This study showed that it is possible to accept uncentrifuged whole blood specimens kept at +4°C before analysis. PTH is affected by freezing whereas vitamin D is not.

Biomarker Analysis of Stored Blood Products: Emphasis on Pre-Analytical Issues

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Delobel, Julien; Rubin, Olivier; Prudent, Michel; Crettaz, David; Tissot, Jean-Daniel; Lion, Niels

2010-01-01

Millions of blood products are transfused every year; many lives are thus directly concerned by transfusion. The three main labile blood products used in transfusion are erythrocyte concentrates, platelet concentrates and fresh frozen plasma. Each of these products has to be stored according to its particular components. However, during storage, modifications or degradation of those components may occur, and are known as storage lesions. Thus, biomarker discovery of in vivo blood aging as well as in vitro labile blood products storage lesions is of high interest for the transfusion medicine community. Pre-analytical issues are of major importance in analyzing the various blood products during storage conditions as well as according to various protocols that are currently used in blood banks for their preparations. This paper will review key elements that have to be taken into account in the context of proteomic-based biomarker discovery applied to blood banking. PMID:21151459

The impact of unrecognized autoimmune rheumatic diseases on the incidence of preeclampsia and fetal growth restriction: a longitudinal cohort study.

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Spinillo, Arsenio; Beneventi, Fausta; Locatelli, Elena; Ramoni, Vèronique; Caporali, Roberto; Alpini, Claudia; Albonico, Giulia; Cavagnoli, Chiara; Montecucco, Carlomaurizio

2016-10-18

The burden of pregnancy complications associated with well defined, already established systemic rheumatic diseases preexisting pregnancy such as rheumatoid arthritis, systemic lupus erythematosus or scleroderma is well known. Systemic rheumatic diseases are characterized by a long natural history with few symptoms, an undifferentiated picture or a remitting course making difficult a timely diagnosis. It has been suggested that screening measures for these diseases could be useful but the impact of unrecognized systemic rheumatic disorders on pregnancy outcome is unknown. The objective of the study was to evaluate the impact of previously unrecognized systemic autoimmune rheumatic on the incidence of preeclampsia and fetal growth restriction (FGR). A longitudinal cohort-study with enrolment during the first trimester of pregnancy of women attending routine antenatal care using a two-step approach with a self-reported questionnaire, autoantibody detection and clinical evaluation of antibody-positive subjects. The incidence of FGR and preeclampsia in subjects with newly diagnosed rheumatic diseases was compared to that of selected negative controls adjusting for potential confounders by logistic regression analysis. The prevalence of previously unrecognized systemic rheumatic diseases was 0.4 % for rheumatoid arthritis (19/5232), 0.25 % (13/5232) for systemic lupus erythematosus, 0.31 % (16/5232) for Sjögren's syndrome, 0.3 % for primary antiphospholipid syndrome (14/5232) and 0.11 % (6/5232) for other miscellaneous diseases. Undifferentiated connective tissue disease was diagnosed in an additional 131 subjects (2.5 %). The incidence of either FGR or preeclampsia was 6.1 % (36/594) among controls and 25.3 % (50/198) in subjects with unrecognized rheumatic diseases (excess incidence = 3.9 % (95 % CI = 2.6-9.6) or 34 % (95 % CI = 22-44) of all cases of FGR/preeclampsia). The incidence of small for gestational age infant (SGA) was higher among

Unrecognized pediatric and adult family members of children with acute brucellosis.

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Çiftdoğan, Dilek Yılmaz; Aslan, Selda

Brucellosis is an infectious, contagious and zoonotic disease that occurs worldwide. The family members of an index case of brucellosis may be especially susceptible, due to sharing the same source of infection and similar risk factors for brucellosis. In this study, we propose to screen pediatric and adult family members of brucellosis index cases for detecting additional unrecognized infected family members. 114 family members of 41 pediatric patients with brucellosis were evaluated. All family members completed a brief questionnaire and were tested by a standard tube agglutination test (STA). The majority of family members (n=96, 84.2%) were children. Among the 114 family members, 42 (36.8%) were seropositive, and 15 (35.7%) were symptomatic. The majority of the symptomatic seropositive family members (n=12, 80%) had STA titers (≥1:640) higher than asymptomatic seropositive family members (n=9, 33%; p=0.004). The routine screening of both pediatric and adult family members of index cases is a priority in endemic areas. Using this screening approach, unrecognized family members who are seropositive for brucellosis will be identified earlier and be able to receive prompt treatment. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Effects of fecal sampling on preanalytical and analytical phases in quantitative fecal immunochemical tests for hemoglobin.

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Rapi, Stefano; Berardi, Margherita; Cellai, Filippo; Ciattini, Samuele; Chelazzi, Laura; Ognibene, Agostino; Rubeca, Tiziana

2017-07-24

Information on preanalytical variability is mandatory to bring laboratories up to ISO 15189 requirements. Fecal sampling is greatly affected by lack of harmonization in laboratory medicine. The aims of this study were to obtain information on the devices used for fecal sampling and to explore the effect of different amounts of feces on the results from the fecal immunochemical test for hemoglobin (FIT-Hb). Four commercial sample collection devices for quantitative FIT-Hb measurements were investigated. The volume of interest (VOI) of the probes was measured from diameter and geometry. Quantitative measurements of the mass of feces were carried out by gravimetry. The effects of an increased amount of feces on the analytical environment were investigated measuring the Hb values with a single analytical method. VOI was 8.22, 7.1 and 9.44 mm3 for probes that collected a target of 10 mg of feces, and 3.08 mm3 for one probe that targeted 2 mg of feces. The ratio between recovered and target amounts of devices ranged from 56% to 121%. Different changes in the measured Hb values were observed, in adding increasing amounts of feces in commercial buffers. The amounts of collected materials are related to the design of probes. Three out 4 manufacturers declare the same target amount using different sampling volumes and obtaining different amounts of collected materials. The introduction of a standard probes to reduce preanalytical variability could be an useful step for fecal test harmonization and to fulfill the ISO 15189 requirements.

Platelet Function Tests: Preanalytical Variables, Clinical Utility, Advantages, and Disadvantages.

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Hvas, Anne-Mette; Grove, Erik Lerkevang

2017-01-01

Platelet function tests are mainly used in the diagnostic work-up of platelet disorders. During the last decade, the additional use of platelet function tests to evaluate the effect of antiplatelet therapy has also emerged in an attempt to identify patients with an increased risk of arterial thrombosis. Furthermore, platelet function tests are increasingly used to measure residual effect of antiplatelet therapy prior to surgery with the aim of reducing the risk of bleeding. To a limited extend, platelet function tests are also used to evaluate hyperaggregability as a potential marker of a prothrombotic state outside the setting of antiplatelet therapy. This multifaceted use of platelet function tests and the development of simpler point-of-care tests with narrower application have increased the use of platelet function testing and also facilitated the use of platelet function tests outside the highly specialized laboratories. The present chapter describes the preanalytical variables, which should be taken into account when planning platelet function testing. Also, the most widely used platelet function tests are introduced, and their clinical utility and their relative advantages and disadvantages are discussed.

Analytical and pre-analytical performance characteristics of a novel cartridge-type blood gas analyzer for point-of-care and laboratory testing.

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Oyaert, Matthijs; Van Maerken, Tom; Bridts, Silke; Van Loon, Silvi; Laverge, Heleen; Stove, Veronique

2018-03-01

Point-of-care blood gas test results may benefit therapeutic decision making by their immediate impact on patient care. We evaluated the (pre-)analytical performance of a novel cartridge-type blood gas analyzer, the GEM Premier 5000 (Werfen), for the determination of pH, partial carbon dioxide pressure (pCO 2 ), partial oxygen pressure (pO 2 ), sodium (Na + ), potassium (K + ), chloride (Cl - ), ionized calcium ( i Ca 2+ ), glucose, lactate, and total hemoglobin (tHb). Total imprecision was estimated according to the CLSI EP5-A2 protocol. The estimated total error was calculated based on the mean of the range claimed by the manufacturer. Based on the CLSI EP9-A2 evaluation protocol, a method comparison with the Siemens RapidPoint 500 and Abbott i-STAT CG8+ was performed. Obtained data were compared against preset quality specifications. Interference of potential pre-analytical confounders on co-oximetry and electrolyte concentrations were studied. The analytical performance was acceptable for all parameters tested. Method comparison demonstrated good agreement to the RapidPoint 500 and i-STAT CG8+, except for some parameters (RapidPoint 500: pCO 2 , K + , lactate and tHb; i-STAT CG8+: pO 2 , Na + , i Ca 2+ and tHb) for which significant differences between analyzers were recorded. No interference of lipemia or methylene blue on CO-oximetry results was found. On the contrary, significant interference for benzalkonium and hemolysis on electrolyte measurements were found, for which the user is notified by an interferent specific flag. Identification of sample errors from pre-analytical sources, such as interferences and automatic corrective actions, along with the analytical performance, ease of use and low maintenance time of the instrument, makes the evaluated instrument a suitable blood gas analyzer for both POCT and laboratory use. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Order of blood draw: Opinion Paper by the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase (WG-PRE)

NARCIS (Netherlands)

Cornes, Michael; van Dongen-Lases, Edmée; Grankvist, Kjell; Ibarz, Mercedes; Kristensen, Gunn; Lippi, Giuseppe; Nybo, Mads; Simundic, Ana-Maria

2017-01-01

It has been well reported over recent years that most errors within the total testing process occur in the pre-analytical phase (46%-68.2%), an area that is usually outside of the direct control of the laboratory and which includes sample collection (phlebotomy). National and international (WHO,

Chasing the effects of Pre-analytical Confounders - a Multicentre Study on CSF-AD biomarkers

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Maria Joao Leitao

2015-07-01

Full Text Available Core cerebrospinal fluid (CSF biomarkers-Aβ42, Tau and pTau–have been recently incorporated in the revised criteria for Alzheimer’s disease (AD. However, their widespread clinical application lacks standardization. Pre-analytical sample handling and storage play an important role in the reliable measurement of these biomarkers across laboratories. In this study, we aim to surpass the efforts from previous studies, by employing a multicentre approach to assess the impact of less studied CSF pre-analytical confounders in AD-biomarkers quantification. Four different centres participated in this study and followed the same established protocol. CSF samples were analysed for three biomarkers (Aβ42, Tau and pTau and tested for different spinning conditions (temperature: Room temperature (RT vs. 4oC; speed: 500g vs. 2000g vs. 3000g, storage volume variations (25%, 50% and 75% of tube total volume as well as freezing-thaw cycles (up to 5 cyles. The influence of sample routine parameters, inter-centre variability and relative value of each biomarker (reported as normal/abnormal, was analysed. Centrifugation conditions did not influence biomarkers levels, except for samples with a high CSF total protein content, where either non centrifugation or centrifugation at RT, compared to 4ºC, led to higher Aβ42 levels. Reducing CSF storage volume from 75% to 50% of total tube capacity, decreased Aβ42 concentration (within analytical CV of the assay, whereas no change in Tau or pTau was observed. Moreover, the concentration of Tau and pTau appears to be stable up to 5 freeze-thaw cycles, whereas Aβ42 levels decrease if CSF is freeze-thawed more than 3 times. This systematic study reinforces the need for CSF centrifugation at 4ºC prior to storage and highlights the influence of storage conditions in Aβ42 levels. This study contributes to the establishment of harmonized standard operating procedures that will help reducing inter-lab variability of CSF

The analytic impact of a reduced centrifugation step on chemistry and immunochemistry assays: an evaluation of the Modular Pre-Analytics.

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Koenders, Mieke M J F; van Hurne, Marco E J F; Glasmacher-Van Zijl, Monique; van der Linde, Geesje; Westerhuis, Bert W J J M

2012-09-01

The COBAS 6000 system can be completed by a Modular Pre-Analytics (MPA), an integrated laboratory automation system that streamlines preanalysis. For an optimal throughput, the MPA centrifuges blood collection tubes for 5 min at 1885 × g - a centrifugation time that is not in concordance with the World Health Organization guidelines which suggest centrifugation for 10/15 min at 2000-3000 × g. In this study, the analytical outcome of 50 serum and 50 plasma samples centrifuged for 5 or 10 min at 1885 × g was investigated. The study included routine chemistry and immunochemistry assays on the COBAS 6000 and the Minicap capillary electrophoresis. Deming-fit and Bland-Altman plots of the 5-min and 10-min centrifugation steps indicated a significant correlation in serum samples. The lipaemia index in plasma samples centrifuged for 5 min displayed a statistically significant variation when compared with the 10-min centrifugation. Preanalytical centrifugation can be successfully down-scaled to a duration of 5 min for most routine chemistry and immunochemistry assays in serum and plasma samples. To prevent inaccurate results in plasma samples with an increased lipaemia index from being reported, the laboratory information system was programmed to withhold results above certain lipaemia indices. The presented data support the use of a 5-min centrifugation step to improve turnaround times, thereby meeting one of the desires of the requesting clinicians.

Pre-analytical and analytical aspects affecting clinical reliability of plasma glucose results.

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Pasqualetti, Sara; Braga, Federica; Panteghini, Mauro

2017-07-01

The measurement of plasma glucose (PG) plays a central role in recognizing disturbances in carbohydrate metabolism, with established decision limits that are globally accepted. This requires that PG results are reliable and unequivocally valid no matter where they are obtained. To control the pre-analytical variability of PG and prevent in vitro glycolysis, the use of citrate as rapidly effective glycolysis inhibitor has been proposed. However, the commercial availability of several tubes with studies showing different performance has created confusion among users. Moreover, and more importantly, studies have shown that tubes promptly inhibiting glycolysis give PG results that are significantly higher than tubes containing sodium fluoride only, used in the majority of studies generating the current PG cut-points, with a different clinical classification of subjects. From the analytical point of view, to be equivalent among different measuring systems, PG results should be traceable to a recognized higher-order reference via the implementation of an unbroken metrological hierarchy. In doing this, it is important that manufacturers of measuring systems consider the uncertainty accumulated through the different steps of the selected traceability chain. In particular, PG results should fulfil analytical performance specifications defined to fit the intended clinical application. Since PG has tight homeostatic control, its biological variability may be used to define these limits. Alternatively, given the central diagnostic role of the analyte, an outcome model showing the impact of analytical performance of test on clinical classifications of subjects can be used. Using these specifications, performance assessment studies employing commutable control materials with values assigned by reference procedure have shown that the quality of PG measurements is often far from desirable and that problems are exacerbated using point-of-care devices. Copyright © 2017 The Canadian

Unrecognized clozapine-related constipation leading to fatal intra-abdominal sepsis – a case report

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Oke V

2015-09-01

Full Text Available Vikram Oke, Frances Schmidt, Bikash Bhattarai, Md Basunia, Chidozie Agu, Amrit Kaur, Danilo Enriquez, Joseph Quist, Divya Salhan, Vijay Gayam, Prajakta Mungikar Department of Pulmonary Medicine, Interfaith Medical Center, NY, USA Abstract: Clozapine is the preferred antipsychotic used for the treatment of resistant schizophrenia with suicidal ideation. The drug is started at a low dose and gradually increased to a target dose of 300–450 mg/day. It is well known to cause agranulocytosis and neutropenia. Several cases of fatal sepsis have been reported in neutropenic patients and emphasis is placed on monitoring for agranulocytosis; however, clozapine also causes intestinal hypomotility and constipation, which if unrecognized can lead to intestinal obstruction, bowel necrosis, and intra-abdominal sepsis. Reduced behavioral pain reactivity in schizophrenics may alter the ability to express pain, potentially leading to a delay in the presentation for medical attention. We report a case of fatal intra-abdominal sepsis secondary to an unrecognized case of clozapine-related constipation. Keywords: antipsychotics, clozapine, schizophrenia, syncope, constipation, sepsis

SPIDIA-RNA: second external quality assessment for the pre-analytical phase of blood samples used for RNA based analyses.

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Francesca Malentacchi

Full Text Available One purpose of the EC funded project, SPIDIA, is to develop evidence-based quality guidelines for the pre-analytical handling of blood samples for RNA molecular testing. To this end, two pan-European External Quality Assessments (EQAs were implemented. Here we report the results of the second SPIDIA-RNA EQA. This second study included modifications in the protocol related to the blood collection process, the shipping conditions and pre-analytical specimen handling for participants. Participating laboratories received two identical proficiency blood specimens collected in tubes with or without an RNA stabilizer. For pre-defined specimen storage times and temperatures, laboratories were asked to perform RNA extraction from whole blood according to their usual procedure and to return extracted RNA to the SPIDIA facility for further analysis. These RNA samples were evaluated for purity, yield, integrity, stability, presence of interfering substances, and gene expression levels for the validated markers of RNA stability: FOS, IL1B, IL8, GAPDH, FOSB and TNFRSF10c. Analysis of the gene expression results of FOS, IL8, FOSB, and TNFRSF10c, however, indicated that the levels of these transcripts were significantly affected by blood collection tube type and storage temperature. These results demonstrated that only blood collection tubes containing a cellular RNA stabilizer allowed reliable gene expression analysis within 48 h from blood collection for all the genes investigated. The results of these two EQAs have been proposed for use in the development of a Technical Specification by the European Committee for Standardization.

Serum protein profiling by solid phase extraction and mass spectrometry: A future diagnostics tool?

DEFF Research Database (Denmark)

Callesen, Anne K; Madsen, Jonna S; Vach, Werner

2009-01-01

Serum protein profiling by MS is a promising method for early detection of disease. Important characteristics for serum protein profiling are preanalytical factors, analytical reproducibility and high throughput. Problems related to preanalytical factors can be overcome by using standardized and ...

Management of thyroid cytological material, pre-analytical procedures and bio-banking.

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Bode-Lesniewska, Beata; Cochand-Priollet, Beatrix; Straccia, Patrizia; Fadda, Guido; Bongiovanni, Massimo

2018-06-09

Thyroid nodules are common and increasingly detected due to recent advances in imaging techniques. However, clinically relevant thyroid cancer is rare and the mortality from aggressive thyroid cancer remains constant. FNAC (Fine Needle Aspiration Cytology) is a standard method for diagnosing thyroid malignancy and the discrimination of malignant nodules from goiter. As the examined nodules on thyroid FNAC are often small incidental findings, it is important to maintain a low rate of undetermined diagnoses requiring further clinical work up or surgery. The most important factors determining the accuracy of the cytological diagnosis and suitability for biobanking of thyroid FNACs are the quality of the sample and availability of adequate tissue for auxiliary studies. This article analyses technical aspects (pre-analytics) of performing thyroid FNACs, including image guidance and rapid on slide evaluation (ROSE), sample collection methods (conventional slides, liquid based methods (LBC), cell blocks) and storage (bio-banking). The spectrum of the special studies (immunocytochemistry on direct slides or LBC, immunohistochemistry on cell blocks and molecular methods) required for improving the precision of the cytological diagnosis of the thyroid nodules is discussed. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Differences in metabolite profiles caused by pre-analytical blood processing procedures.

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Nishiumi, Shin; Suzuki, Makoto; Kobayashi, Takashi; Yoshida, Masaru

2018-05-01

Recently, the use of metabolomic analysis of human serum and plasma for biomarker discovery and disease diagnosis in clinical studies has been increasing. The feasibility of using a metabolite biomarker for disease diagnosis is strongly dependent on the metabolite's stability during pre-analytical blood processing procedures, such as serum or plasma sampling and sample storage prior to centrifugation. However, the influence of blood processing procedures on the stability of metabolites has not been fully characterized. In the present study, we compared the levels of metabolites in matched human serum and plasma samples using gas chromatography coupled with mass spectrometry and liquid chromatography coupled with mass spectrometry. In addition, we evaluated the changes in plasma metabolite levels induced by storage at room temperature or at a cold temperature prior to centrifugation. As a result, it was found that 76 metabolites exhibited significant differences between their serum and plasma levels. Furthermore, the pre-centrifugation storage conditions significantly affected the plasma levels of 45 metabolites. These results highlight the importance of blood processing procedures during metabolome analysis, which should be considered during biomarker discovery and the subsequent use of biomarkers for disease diagnosis. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Pre-Analytical Considerations for Successful Next-Generation Sequencing (NGS: Challenges and Opportunities for Formalin-Fixed and Paraffin-Embedded Tumor Tissue (FFPE Samples

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Gladys Arreaza

2016-09-01

Full Text Available In cancer drug discovery, it is important to investigate the genetic determinants of response or resistance to cancer therapy as well as factors that contribute to adverse events in the course of clinical trials. Despite the emergence of new technologies and the ability to measure more diverse analytes (e.g., circulating tumor cell (CTC, circulating tumor DNA (ctDNA, etc., tumor tissue is still the most common and reliable source for biomarker investigation. Because of its worldwide use and ability to preserve samples for many decades at ambient temperature, formalin-fixed, paraffin-embedded tumor tissue (FFPE is likely to be the preferred choice for tissue preservation in clinical practice for the foreseeable future. Multiple analyses are routinely performed on the same FFPE samples (such as Immunohistochemistry (IHC, in situ hybridization, RNAseq, DNAseq, TILseq, Methyl-Seq, etc.. Thus, specimen prioritization and optimization of the isolation of analytes is critical to ensure successful completion of each assay. FFPE is notorious for producing suboptimal DNA quality and low DNA yield. However, commercial vendors tend to request higher DNA sample mass than what is actually required for downstream assays, which restricts the breadth of biomarker work that can be performed. We evaluated multiple genomics service laboratories to assess the current state of NGS pre-analytical processing of FFPE. Significant differences in pre-analytical capabilities were observed. Key aspects are highlighted and recommendations are made to improve the current practice in translational research.

Sources of pre-analytical variations in yield of DNA extracted from blood samples: analysis of 50,000 DNA samples in EPIC.

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Elodie Caboux

Full Text Available The European Prospective Investigation into Cancer and nutrition (EPIC is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88% performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies.

Aspectos prácticos de la fase preanalítica del estudio de biovigilancia BIOAMBIENT.ES Practical features of the pre-analytical phase of the BIOAMBIENT.ES biomonitoring study

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Marta Esteban

2013-02-01

Full Text Available Entre marzo de 2009 y julio de 2010 se desarrolló el trabajo de campo de BIOAMBIENT.ES, un estudio de biovigilancia de contaminantes ambientales en humanos de cobertura nacional. Esta nota pretende mostrar las tareas desarrolladas antes del comienzo del trabajo de campo con el fin de asegurar la calidad de las muestras recogidas, y consecuentemente de los resultados obtenidos. Se recogieron 1936 muestras de sangre, suero y orina, y 604 muestras de pelo, de trabajadores que acudían al reconocimiento anual de salud laboral en 38 centros de la Península, Ceuta y Canarias. Previamente se identificó el material idóneo para la recogida y el transporte de las muestras, y se entrenó al personal de campo. La planificación y la organización de la fase preanalítica hizo posible que menos del 1% de las muestras recogidas tuvieran que rechazarse por problemas de derrames, conservación, etc. Asimismo, los análisis no reflejan la presencia de interferencias preanalíticas.The fieldwork of BIOAMBIENT.ES was developed from March 2009 to July 2010. BIOAMBIENT.ES is a human biomonitoring study of environmental pollutants performed in Spain at the national level. This article aims to show the tasks performed before starting the fieldwork to ensure the quality of the samples and consequently the quality of the results. A total of 1,936 whole blood, serum and first-morning urine samples and 604 hair samples were collected from workers who attended the annual occupational health examination in 38 centers in the Peninsula, Ceuta and the Canary Islands. Before the fieldwork was started, the optimal sampling material and sample shipment was identified and fieldworkers were trained in their tasks. Due to the planning and organization of the pre-analytical phase, only 1% of the collected samples had to be rejected due to problem with spills, conservation, etc. In addition, the analyses conducted showed no pre-analytical interferences.

Compliance of blood sampling procedures with the CLSI H3-A6 guidelines: An observational study by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) working group for the preanalytical phase (WG-PRE)

NARCIS (Netherlands)

Simundic, Ana-Maria; Church, Stephen; Cornes, Michael P.; Grankvist, Kjell; Lippi, Giuseppe; Nybo, Mads; Nikolac, Nora; van Dongen-Lases, Edmee; Eker, Pinar; Kovalevskaya, Svjetlana; Kristensen, Gunn B. B.; Sprongl, Ludek; Sumarac, Zorica

2015-01-01

Abstract Background: An observational study was conducted in 12 European countries by the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) to assess the level of compliance with the CLSI H3-A6 guidelines. Methods: A structured

MALDI-TOF MS identification of anaerobic bacteria: assessment of pre-analytical variables and specimen preparation techniques.

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Hsu, Yen-Michael S; Burnham, Carey-Ann D

2014-06-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a tool for identifying clinically relevant anaerobes. We evaluated the analytical performance characteristics of the Bruker Microflex with Biotyper 3.0 software system for identification of anaerobes and examined the impact of direct formic acid (FA) treatment and other pre-analytical factors on MALDI-TOF MS performance. A collection of 101 anaerobic bacteria were evaluated, including Clostridium spp., Propionibacterium spp., Fusobacterium spp., Bacteroides spp., and other anaerobic bacterial of clinical relevance. The results of our study indicate that an on-target extraction with 100% FA improves the rate of accurate identification without introducing misidentification (Panaerobes grown in suboptimal conditions, such as on selective culture media and following oxygen exposure. In conclusion, we report on a number of simple and cost-effective pre- and post-analytical modifications could enhance MALDI-TOF MS identification for anaerobic bacteria. Copyright © 2014 Elsevier Inc. All rights reserved.

The impact of pre-analytical variables on the stability of neurofilament proteins in CSF, determined by a novel validated SinglePlex Luminex assay and ELISA.

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Koel-Simmelink, Marleen J A; Vennegoor, Anke; Killestein, Joep; Blankenstein, Marinus A; Norgren, Niklas; Korth, Carsten; Teunissen, Charlotte E

2014-01-15

Neurofilament (Nf) proteins have been shown to be promising biomarkers for monitoring and predicting disease progression for various neurological diseases. The aim of this study was to evaluate the effects of pre-analytical variables on the concentration of neurofilament heavy (NfH) and neurofilament light (NfL) proteins. For NfH an in-house newly-developed and validated SinglePlex Luminex assay was used; ELISA was used to analyze NfL. For the NfL ELISA assay, the intra- and inter-assay variation was respectively, 1.5% and 16.7%. Analytical performance of the NfH SinglePlex Luminex assay in terms of sensitivity (6.6pg/mL), recovery in cerebrospinal fluid (CSF) (between 90 and 104%), linearity (from 6.6-1250pg/mL), and inter- and intra-assay variation (<8%) were good. Concentrations of both NfL and NfH appeared not negatively affected by blood contamination, repeated freeze-thaw cycles (up to 4), delayed processing (up to 24hours) and during long-term storage at -20°C, 4°C, and room temperature. A decrease in concentration was observed during storage of both neurofilament proteins up to 21days at 37°C, which was significant by day 5. The newly developed NfH SinglePlex Luminex assay has a good sensitivity and is robust. Moreover, both NfH and NfL are stable under the most prevalent pre-analytical variations. Copyright © 2013 Elsevier B.V. All rights reserved.

A Systematic Evaluation of Blood Serum and Plasma Pre-Analytics for Metabolomics Cohort Studies

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Elodie Jobard

2016-12-01

Full Text Available The recent thriving development of biobanks and associated high-throughput phenotyping studies requires the elaboration of large-scale approaches for monitoring biological sample quality and compliance with standard protocols. We present a metabolomic investigation of human blood samples that delineates pitfalls and guidelines for the collection, storage and handling procedures for serum and plasma. A series of eight pre-processing technical parameters is systematically investigated along variable ranges commonly encountered across clinical studies. While metabolic fingerprints, as assessed by nuclear magnetic resonance, are not significantly affected by altered centrifugation parameters or delays between sample pre-processing (blood centrifugation and storage, our metabolomic investigation highlights that both the delay and storage temperature between blood draw and centrifugation are the primary parameters impacting serum and plasma metabolic profiles. Storing the blood drawn at 4 °C is shown to be a reliable routine to confine variability associated with idle time prior to sample pre-processing. Based on their fine sensitivity to pre-analytical parameters and protocol variations, metabolic fingerprints could be exploited as valuable ways to determine compliance with standard procedures and quality assessment of blood samples within large multi-omic clinical and translational cohort studies.

During childhood unrecognized congenital heart defect in patient with Turner syndrome, and its implications

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Klaskova, E.; Kapralova, S.; Zapletalova, J.; Tuedoes, Z.

2015-01-01

Congenital heart disease affects approximately 50 % of individuals with Turner syndrome (TS). Bicuspid aortic valve, aortic coarctation, ascending aorta dilatation and arterial hypertension are important risk factors for life-threatening aortic dissection or rupture. Authors discuss the importance of a careful cardiac examination including cardiac magnetic resonance imaging study and life-long follow-up by experienced cardiologist in TS patients, and point out high maternal mortality and morbidity during pregnancy. They present a case report of woman with TS and the above-mentioned in childhood unrecognized congenital heart defects that underwent infertility treatment without pre conceptional counselling focused on cardiovascular risk for aortic dissection. (author)

Alcohol use and policy formation: an evolving social problem.

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Levine, Amir

2012-01-01

This article explores the evolutionary course that the social problem of alcohol use has taken in the United States since the Colonial Era. This article utilizes a range of theoretical models to analyze the evolving nature of alcohol use from an unrecognized to a perceived social problem. The models used include critical constructionism (Heiner, 2002), top-down policy model (Dye, 2001) and Mauss'(1975) understanding of social problems and movements. These theoretical constructs exhibit the relative nature of alcohol use as a social problem in regards to a specific time, place, and social context as well as the powerful and influential role that social elites have in defining alcohol asa social problem. Studies regarding the development of alcohol policy formation are discussed to illuminate the different powers, constituents, and factors that play a role in alcohol policy formation.Finally, implications for future study are discussed [corrected].

A Republican Egalitarian Approach to Bioethics: The Case of the Unrecognized Bedouin Villages in Israel.

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Filc, Dani; Davidovich, Nadav; Gottlieb, Nora

2016-10-01

This article argues that current, mainstream, liberal approaches to the right to health and to bioethics are not adequately aware of the structural and political character of health and illness. We propose a radical egalitarian definition of the right to health as the basis for the discussion of a republican egalitarian perspective on bioethics that redefines autonomy and stresses the importance of equality, political participation, and the common good. The violations of the right to health in unrecognized Bedouin villages in Israel are analyzed to exemplify the possibilities opened by the republican egalitarian approach. © The Author(s) 2015.

Preeclampsia: is it because of the asymptomatic, unrecognized renal scars caused by urinary tract infections in childhood that become symptomatic with pregnancy?

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Ozlü, Tülay; Alçelik, Aytekin; Calişkan, Billur; Dönmez, Melahat Emine

2012-11-01

Preeclampsia is an important disease of pregnancy whose exact etiology is still unknown despite continuing developments in medicine. Although most commonly it is believed to be caused by a defective placentation, in this paper, we hypothesize that the primary underlying problem in the development of preeclampsia can be in kidneys in a greater proportion of cases than it is believed today. The increased intravascular volume and the increased work load of kidneys together with the resulting glomerular hypertrophy may precipitate nephrotic syndrome, which in this case is called "preeclampsia" in a previously affected kidney. Urinary tract infections in childhood leaving silent, unrecognized small scars in the kidneys may be the underlying renal cause which disrupts its silence with an increased work load of kidneys prominently occurring after the midtrimester. The histopathologic finding in kidneys with renal scars after childhood urinary tract infections and in preeclampsia is focal segmental glomerulosclerosis in the majority of cases and this similarity strengthens our hypothesis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preanalytic Factors Associated With Hemolysis in Emergency Department Blood Samples.

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Phelan, Michael P; Reineks, Edmunds Z; Schold, Jesse D; Hustey, Frederic M; Chamberlin, Janelle; Procop, Gary W

2018-02-01

- Hemolysis of emergency department blood samples is a common occurrence and has a negative impact on health care delivery. - To determine the effect of preanalytic factors (straight stick, intravenous [IV] line, needle gauge, location of blood draw, syringe versus vacuum tube use, tourniquet time) on hemolysis in emergency department blood samples. - A single 65 000-visit emergency department's electronic health record was queried for emergency department potassium results and blood draw technique for all samples obtained in calendar year 2014, resulting in 54 531 potassium results. Hemolyzed potassium was measured by hemolysis index. Comparisons of hemolysis by sampling technique were conducted by χ 2 tests. - Overall hemolysis was 10.0% (5439 of 54 531). Hemolysis among samples obtained from straight stick was significantly less than among those obtained with IV line (5.4% [33 of 615] versus 10.2% [4821 of 47 266], P < .001). For IV-placed blood draws, antecubital location had a statistically significant lower overall hemolysis compared with other locations: 7.4% (2117 of 28 786) versus 14.6% (2622 of 17 960) ( P < .001). For blood drawn with a syringe compared with vacuum, hemolysis was 13.0% (92 of 705) and 11.0% (1820 of 16 590), respectively ( P = .09, not significant). For large-gauge IV blood draws versus smaller-gauge IV lines, a lower hemolysis was also observed (9.3% [3882 of 41 571] versus 16.7% [939 of 5633]) ( P < .001). For IV-drawn blood with tourniquet time less than 60 seconds, hemolysis was 10.3% (1362 of 13 162) versus 13.9% for more than 60 seconds (532 of 3832), P < .001. - This study confirmed previous findings that straight stick and antecubital location are significantly associated with reduced hemolysis and indicated that shorter tourniquet time and larger gauge for IV draws were significantly associated with lower hemolysis.

Prevalence of unrecognized depression and associated factors among patients attending medical outpatient department in Adare Hospital, Hawassa, Ethiopia

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Tilahune AB

2016-10-01

Full Text Available Asres Bedaso Tilahune,1 Gezahegn Bekele,1 Nibretie Mekonnen,2 Eyerusalem Tamiru2 1School of Nursing and Midwifery, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia; 2Department of Medical Case Team, Hawassa University Comprehensive Specialized Hospital, Hawassa, Ethiopia Abstract: Depression is an illness that involves the body, mood, and thoughts and that affects the way a person eats, sleeps, feels about him or herself and thinks about things. Depression is one of the most common mental disorders affecting 121 million people in the world, and it frequently goes unrecognized among patients. It is estimated that 5%–10% of the population at any given time is suffering from identifiable depression needing psychiatric or psychosocial intervention. An institution-based cross-sectional study design was implemented to determine the magnitude and associated factors of unrecognized depression among patients attending the adult medical outpatient department in Adare Hospital, Hawassa, Southern Nations, Nationalities, and Peoples’ Region, Ethiopia, among 326 patients selected using systematic random sampling technique. Data were collected using the interviewer-administered technique. A structured questionnaire was used to collect data on sociodemographic characteristics and other independent variables. Depression was assessed using the Patient Health Questionnaire 9. Data were entered and analyzed using SPSS 20. The level of significance was determined at P<0.05. About 326 patients were interviewed, of whom 186 (57.1% were males. The mean age of participant was 34 with standard deviation of ±13.1 years. Current substance users accounted for 106 (32.5% of the total participants. Of 326 respondents, 80 (24.5% had significant depressive symptoms, while the detection rate of depression by the clinician was 0%. Depression was associated with female sex (adjusted odds ratio [AOR] =1.63 [1.14–2.34], age >60 years (AOR =4

Polyamine modification by acrolein exclusively produces 1,5-diazacyclooctanes: a previously unrecognized mechanism for acrolein-mediated oxidative stress.

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Tsutsui, Ayumi; Imamaki, Rie; Kitazume, Shinobu; Hanashima, Shinya; Yamaguchi, Yoshiki; Kaneda, Masato; Oishi, Shinya; Fujii, Nobutaka; Kurbangalieva, Almira; Taniguchi, Naoyuki; Tanaka, Katsunori

2014-07-28

Acrolein, a toxic unsaturated aldehyde generated as a result of oxidative stress, readily reacts with a variety of nucleophilic biomolecules. Polyamines, which produced acrolein in the presence of amine oxidase, were then found to react with acrolein to produce 1,5-diazacyclooctane, a previously unrecognized but significant downstream product of oxidative stress. Although diazacyclooctane formation effectively neutralized acrolein toxicity, the diazacyclooctane hydrogel produced through a sequential diazacyclooctane polymerization reaction was highly cytotoxic. This study suggests that diazacyclooctane formation is involved in the mechanism underlying acrolein-mediated oxidative stress.

Blood venous sample collection: Recommendations overview and a checklist to improve quality.

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Giavarina, Davide; Lippi, Giuseppe

2017-07-01

The extra-analytical phases of the total testing process have substantial impact on managed care, as well as an inherent high risk of vulnerability to errors which is often greater than that of the analytical phase. The collection of biological samples is a crucial preanalytical activity. Problems or errors occurring shortly before, or soon after, this preanalytical step may impair sample quality and characteristics, or else modify the final results of testing. The standardization of fasting requirements, rest, patient position and psychological state of the patient are therefore crucial for mitigating the impact of preanalytical variability. Moreover, the quality of materials used for collecting specimens, along with their compatibility, can guarantee sample quality and persistence of chemical and physical characteristics of the analytes over time, so safeguarding the reliability of testing. Appropriate techniques and sampling procedures are effective to prevent problems such as hemolysis, undue clotting in the blood tube, draw of insufficient sample volume and modification of analyte concentration. An accurate identification of both patient and blood samples is a key priority as for other healthcare activities. Good laboratory practice and appropriate training of operators, by specifically targeting collection of biological samples, blood in particular, may greatly improve this issue, thus lowering the risk of errors and their adverse clinical consequences. The implementation of a simple and rapid check-list, including verification of blood collection devices, patient preparation and sampling techniques, was found to be effective for enhancing sample quality and reducing some preanalytical errors associated with these procedures. The use of this tool, along with implementation of objective and standardized systems for detecting non-conformities related to unsuitable samples, can be helpful for standardizing preanalytical activities and improving the quality of

Quality assurance in the pre-analytical phase of human urine samples by (1)H NMR spectroscopy.

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Budde, Kathrin; Gök, Ömer-Necmi; Pietzner, Maik; Meisinger, Christine; Leitzmann, Michael; Nauck, Matthias; Köttgen, Anna; Friedrich, Nele

2016-01-01

Metabolomic approaches investigate changes in metabolite profiles, which may reflect changes in metabolic pathways and provide information correlated with a specific biological process or pathophysiology. High-resolution (1)H NMR spectroscopy is used to identify metabolites in biofluids and tissue samples qualitatively and quantitatively. This pre-analytical study evaluated the effects of storage time and temperature on (1)H NMR spectra from human urine in two settings. Firstly, to evaluate short time effects probably due to acute delay in sample handling and secondly, the effect of prolonged storage up to one month to find markers of sample miss-handling. A number of statistical procedures were used to assess the differences between samples stored under different conditions, including Projection to Latent Structure Discriminant Analysis (PLS-DA), non-parametric testing as well as mixed effect linear regression analysis. The results indicate that human urine samples can be stored at 10 °C for 24 h or at -80 °C for 1 month, as no relevant changes in (1)H NMR fingerprints were observed during these time periods and temperature conditions. However, some metabolites most likely of microbial origin showed alterations during prolonged storage but without facilitating classification. In conclusion, the presented protocol for urine sample handling and semi-automatic metabolite quantification is suitable for large-scale epidemiological studies. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparative study of family functioning, health, and mental health awareness and utilization among female Bedouin-Arabs from recognized and unrecognized villages in the Negev.

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Al-Krenawi, Alean; Graham, John R

2006-02-01

A good portion of geography is contested by the Israeli state and the country's Bedouin-Arab population. There are two categories of Bedouin villages: those areas that are "officially" recognized by the state and those that are not. In this article we determine utilization and awareness of health and mental health services among 376 Bedouin-Arab women in recognized and unrecognized villages in the Negev. Although there are differences between them, primary health care (PHC) services usually are available within recognized villages, accessible to those from unrecognized villages, and tend to precipitate user satisfaction. We conclude with various suggestions for improving health service delivery and making PHC and mental health delivery more accessible. Through this article we intend to help mental health practitioners on two levels: the policy level, regarding the design of mental health services for societies in transition, such as the Bedouin Arab, and the practical level by helping practitioners better appreciate the psychosocial status of women in Bedouin-Arab societies and the factors associated with Bedouin-Arab PHC utilization.

Adult pertussis is unrecognized public health problem in Thailand.

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Siriyakorn, Nirada; Leethong, Pornvimol; Tantawichien, Terapong; Sripakdee, Saowalak; Kerdsin, Anusak; Dejsirilert, Surang; Paitoonpong, Leilani

2016-01-25

Although pertussis has been considered a disease of childhood, it is also recognized as an important respiratory tract infection in adolescents and adults. However, in countries with routine vaccination against pertussis with high coverage, pertussis is not usually taken into consideration for the etiology of prolonged cough in adults. Previous studies in a variety of populations in developed countries have documented that pertussis is quite common, ranging from 2.9 to 32% of adolescents and adults with prolonged cough. The anticipation and early recognition of this change in the epidemiology is important because the affected adolescents and adults act as reservoirs of the disease and source of infection to the vulnerable population of infants, for whom the disease can be life threatening. We conducted a prospective study to determine the prevalence of pertussis in Thai adults with prolonged cough. Seventy-six adult patients with a cough lasting for more than 2 weeks (range, 14-180 days) were included in the present study. The data regarding medical history and physical examination were carefully analyzed. Nasopharyngeal swabs from all patients were obtained for the detection of deoxyribonucleic acid of Bordetella pertussis by the polymerase chain reaction (PCR) method. Paired serum samples were collected and tested for IgG antibody against pertussis toxin by using an ELISA method. Of 76 adult patients, 14 patients (18.4%) with the mean age of 59 (range, 28-85) years and the mean duration of cough of 34 (range, 14-120) days had laboratory evidence of acute pertussis infection. One patient was diagnosed by the PCR method, while the rest had serological diagnosis. Whooping cough is a significantly associated symptom of patients with chronic cough who had laboratory evidence of pertussis. (p < .05, odds ratio 3.75, 95% confidence interval: 1.00, 14.06) CONCLUSION: Pertussis is being increasingly recognized as a cause of prolonged, distressing cough among adults in Thailand. This result addresses the need of pertussis vaccination in Thai adults for preventing transmission to a high risk group such as newborn infants.

Pre-analytical and Analytical Variables Affecting the Measurement of Plasma-Derived Microparticle Tissue Factor Activity

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Lee, RD; Barcel, DA; Williams, JC; Wang, JG; Boles, JC; Manly, DA; Key, NS; Mackman, N

2011-01-01

Introduction Elevated levels of tissue factor positive (TF+) microparticles (MPs) are observed in plasma from a variety of patients with an increased risk of thrombosis. We and others have described the measurement of TF activity in MPs isolated from plasma. The aim of this study was to investigate the effects of pre-analytical and analytical variables on TF activity of MPs isolated from blood of healthy volunteers treated ex vivo with or without bacterial lipopolysaccharide. Materials and Methods We evaluated the following parameters: use of different centrifugation speeds to isolate the MPs; comparison of TF activity of MPs isolated from platelet poor plasma versus platelet free plasma; effect of freeze/thaw on MP TF activity; and comparison of the MP TF activity assay with the measurement of TF protein by ELISA or flow cytometry. Results MPs prepared from platelet poor plasma by centrifugation at 20,000 × g or 100,000 × g for 15 minutes had similar levels of TF activity. However, significantly less TF activity was found in MPs isolated from platelet free plasma compared with platelet poor plasma. Interestingly, freeze/thawing of the plasma showed donor to donor variation in MP TF activity, with a moderate increase in some individuals. Conclusion TF+ MPs can be quantitatively isolated from platelet poor or platelet free plasma by centrifugation at 20,000 × g for 15 minutes. Measurement of MP TF activity in plasma can be used to detect a prothrombotic state in patients with various diseases. PMID:21737126

Prevention of unrecognized joint penetration during internal fixation of hip fractures: a geometric model based on Steinmetz Solid.

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Mao, Yujiang; Song, Jie; Wei, Jie; Wang, Manyi

2010-01-01

Unrecognized joint penetration (UJP) by screw penetration through the articular surface undetectable on routine anteroposterior (AP) and lateral radiographs can cause serious complications. We have developed a geometric model to analyze UJP, and methods for the prevention of the problem. A Steinmetz Solid (SS) is the overlapping portion between two identical, vertically intersecting cylinders. The AP and lateral radiographs of a femoral head (simplified as a sphere) are projections of two cylinder-shaped images. A screw that appears to be within the femoral head in fact only lies within the cylinder. A screw apparently within the femoral head on both AP and lateral images is only confined to the SS generated by two cylinders, but not necessarily confined to the femoral head itself. We have therefore analyzed UJP using a geometric model based on SS. The geometric basis of UJP lies in the fact that the SS is larger than the sphere (femoral head) with a volume ratio of 4: π. The theoretical risk of UJP for any screw therefore can be as high as 21.5% ((4-π)/4). In reality, screws are always carefully placed to ensure a distance between the screw's tip and the edge of femoral head (tip-to-edge distance, or TED). This TED effectively lowers the risk of UJP by reducing the size of the screw-confining SS. When the SS entirely fits into (internally tangential to) the femoral head, the risk of UJP approaches zero. A TED fulfilling this requirement can be regarded as safe (approximately 0.29 x femoral head radius). With a femoral head diameter of 5 cm, the safe TED is approximately 7 mm.

Pre-analytical conditions in non-invasive prenatal testing of cell-free fetal RHD.

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Frederik Banch Clausen

Full Text Available Non-invasive prenatal testing of cell-free fetal DNA (cffDNA in maternal plasma can predict the fetal RhD type in D negative pregnant women. In Denmark, routine antenatal screening for the fetal RhD gene (RHD directs the administration of antenatal anti-D prophylaxis only to women who carry an RhD positive fetus. Prophylaxis reduces the risk of immunization that may lead to hemolytic disease of the fetus and the newborn. The reliability of predicting the fetal RhD type depends on pre-analytical factors and assay sensitivity. We evaluated the testing setup in the Capital Region of Denmark, based on data from routine antenatal RHD screening.Blood samples were drawn at gestational age 25 weeks. DNA extracted from 1 mL of plasma was analyzed for fetal RHD using a duplex method for exon 7/10. We investigated the effect of blood sample transportation time (n = 110 and ambient outdoor temperatures (n = 1539 on the levels of cffDNA and total DNA. We compared two different quantification methods, the delta Ct method and a universal standard curve. PCR pipetting was compared on two systems (n = 104.The cffDNA level was unaffected by blood sample transportation for up to 9 days and by ambient outdoor temperatures ranging from -10 °C to 28 °C during transport. The universal standard curve was applicable for cffDNA quantification. Identical levels of cffDNA were observed using the two automated PCR pipetting systems. We detected a mean of 100 fetal DNA copies/mL at a median gestational age of 25 weeks (range 10-39, n = 1317.The setup for real-time PCR-based, non-invasive prenatal testing of cffDNA in the Capital Region of Denmark is very robust. Our findings regarding the transportation of blood samples demonstrate the high stability of cffDNA. The applicability of a universal standard curve facilitates easy cffDNA quantification.

Uncertainty in soil carbon accounting due to unrecognized soil erosion.

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Sanderman, Jonathan; Chappell, Adrian

2013-01-01

The movement of soil organic carbon (SOC) during erosion and deposition events represents a major perturbation to the terrestrial carbon cycle. Despite the recognized impact soil redistribution can have on the carbon cycle, few major carbon accounting models currently allow for soil mass flux. Here, we modified a commonly used SOC model to include a soil redistribution term and then applied it to scenarios which explore the implications of unrecognized erosion and deposition for SOC accounting. We show that models that assume a static landscape may be calibrated incorrectly as erosion of SOC is hidden within the decay constants. This implicit inclusion of erosion then limits the predictive capacity of these models when applied to sites with different soil redistribution histories. Decay constants were found to be 15-50% slower when an erosion rate of 15 t soil ha(-1)  yr(-1) was explicitly included in the SOC model calibration. Static models cannot account for SOC change resulting from agricultural management practices focused on reducing erosion rates. Without accounting for soil redistribution, a soil sampling scheme which uses a fixed depth to support model development can create large errors in actual and relative changes in SOC stocks. When modest levels of erosion were ignored, the combined uncertainty in carbon sequestration rates was 0.3-1.0 t CO2  ha(-1)  yr(-1) . This range is similar to expected sequestration rates for many management options aimed at increasing SOC levels. It is evident from these analyses that explicit recognition of soil redistribution is critical to the success of a carbon monitoring or trading scheme which seeks to credit agricultural activities. © 2012 Blackwell Publishing Ltd.

Unrecognized Myocardial Infarction Assessed by Cardiac Magnetic Resonance Imaging--Prognostic Implications.

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Anna M Nordenskjöld

Full Text Available Clinically unrecognized myocardial infarctions (UMI are not uncommon and may be associated with adverse outcome. The aims of this study were to determine the prognostic implication of UMI in patients with stable suspected coronary artery disease (CAD and to investigate the associations of UMI with the presence of CAD.In total 235 patients late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR imaging and coronary angiography were performed. For each patient with UMI, the stenosis grade of the coronary branch supplying the infarcted area was determined. UMIs were present in 25% of the patients and 67% of the UMIs were located in an area supplied by a coronary artery with a stenosis grade ≥70%. In an age- and gender-adjusted model, UMI independently predicted the primary endpoint (composite of death, myocardial infarction, resuscitated cardiac arrest, hospitalization for unstable angina pectoris or heart failure within 2 years of follow-up with an odds ratio of 2.9; 95% confidence interval 1.1-7.9. However, this association was abrogated after adjustment for age and presence of significant coronary disease. There was no difference in the primary endpoint rates between UMI patients with or without a significant stenosis in the corresponding coronary artery.The presence of UMI was associated with a threefold increased risk of adverse events during follow up. However, the difference was no longer statistically significant after adjustments for age and severity of CAD. Thus, the results do not support that patients with suspicion of CAD should be routinely investigated by LGE-CMR for UMI. However, coronary angiography should be considered in patients with UMI detected by LGE-CMR.ClinicalTrials.gov NTC01257282.

Previously Unrecognized Ornithuromorph Bird Diversity in the Early Cretaceous Changma Basin, Gansu Province, Northwestern China

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Wang, Ya-Ming; O'Connor, Jingmai K.; Li, Da-Qing; You, Hai-Lu

2013-01-01

Here we report on three new species of ornithuromorph birds from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province, northwestern China: Yumenornis huangi gen. et sp. nov., Changmaornis houi gen. et sp. nov., and Jiuquanornis niui gen. et sp. nov.. The last of these is based on a previously published but unnamed specimen: GSGM-05-CM-021. Although incomplete, the specimens can be clearly distinguished from each other and from Gansus yumenensis Hou and Liu, 1984. Phylogenetic analysis resolves the three new taxa as basal ornithuromorphs. This study reveals previously unrecognized ornithuromorph diversity in the Changma avifauna, which is largely dominated by Gansus but with at least three other ornithuromorphs. Body mass estimates demonstrate that enantiornithines were much smaller than ornithuromorphs in the Changma avifauna. In addition, Changma enantiornithines preserve long and recurved pedal unguals, suggesting an arboreal lifestyle; in contrast, Changma ornithuromorphs tend to show terrestrial or even aquatic adaptions. Similar differences in body mass and ecology are also observed in the Jehol avifauna in northeastern China, suggesting niche partitioning between these two clades developed early in their evolutionary history. PMID:24147058

Fat, demented and stupid: An unrecognized legacy of pediatric urology?

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Cooper, Christopher S

2017-08-01

The human body is an unfathomably intricate structure consisting of many connected and intertwined systems. This makes it impossible for therapeutic interventions to selectively target only one physiologic system without some impact or side effects on all the other systems. The resiliency of the human body modifies and disguises side effects, some of which may be undetectable for years and not apparent without scientific investigation. Pediatric urologists employ relatively few medications for the common conditions they treat and in general these consist of antibiotics, anticholinergics, and anesthetics. Although harm from early side effects is well recognized, recent medical literature suggests there may be other side effects of these common interventions that aren't as well recognized. Antibiotics have been added to livestock feed as growth promoters for three-quarters of a century. Antibiotics alter the microbiota of the intestinal tract and these alterations have been demonstrated to impact growth, metabolism, and the risk of obesity in animals and humans. To date, the long-term impact of daily antibiotic prophylaxis in children with such pediatric urology conditions as vesicoureteral reflux or prenatal hydronephrosis have not been published. Similarly, there are no studies assessing long-term effects of anticholinergic use on cognition in children despite research demonstrating an increased risk of dementia in adults using anticholinergics. Research in animals and children recently led the FDA to issue a warning regarding the risk of lengthy use of general anesthesia on cognitive development in children. This review raises the possibility that antibiotics in children may alter growth, anticholinergics may increase their risk of dementia later in life, and anesthetics may impair their cognitive development. The possibility of such an unrecognized legacy from current therapeutic interventions should give all physicians, including pediatric urologists, pause for

ASVCP quality assurance guidelines: control of preanalytical, analytical, and postanalytical factors for urinalysis, cytology, and clinical chemistry in veterinary laboratories.

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Gunn-Christie, Rebekah G; Flatland, Bente; Friedrichs, Kristen R; Szladovits, Balazs; Harr, Kendal E; Ruotsalo, Kristiina; Knoll, Joyce S; Wamsley, Heather L; Freeman, Kathy P

2012-03-01

In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and documents recommendations for control of preanalytical, analytical, and postanalytical factors related to urinalysis, cytology, and clinical chemistry in veterinary laboratories and is adapted from sections 1.1 and 2.2 (clinical chemistry), 1.3 and 2.5 (urinalysis), 1.4 and 2.6 (cytology), and 3 (postanalytical factors important in veterinary clinical pathology) of these guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. © 2012 American Society for Veterinary Clinical Pathology.

Preanalytical blood sample workup for cell-free DNA analysis using Droplet Digital PCR for future molecular cancer diagnostics.

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van Ginkel, Joost H; van den Broek, Daan A; van Kuik, Joyce; Linders, Dorothé; de Weger, Roel; Willems, Stefan M; Huibers, Manon M H

2017-10-01

In current molecular cancer diagnostics, using blood samples of cancer patients for the detection of genetic alterations in plasma (cell-free) circulating tumor DNA (ctDNA) is an emerging practice. Since ctDNA levels in blood are low, highly sensitive Droplet Digital PCR (ddPCR) can be used for detecting rare mutational targets. In order to perform ddPCR on blood samples, a standardized procedure for processing and analyzing blood samples is necessary to facilitate implementation into clinical practice. Therefore, we assessed the technical sample workup procedure for ddPCR on blood plasma samples. Blood samples from healthy individuals, as well as lung cancer patients were analyzed. We compared different methods and protocols for sample collection, storage, centrifugation, isolation, and quantification. Cell-free DNA (cfDNA) concentrations of several wild-type targets and BRAF and EGFR-mutant ctDNA concentrations quantified by ddPCR were primary outcome measurements. Highest cfDNA concentrations were measured in blood collected in serum tubes. No significant differences in cfDNA concentrations were detected between various time points of up to 24 h until centrifugation. Highest cfDNA concentrations were detected after DNA isolation with the Quick cfDNA Serum & Plasma Kit, while plasma isolation using the QIAamp Circulating Nucleic Acid Kit yielded the most consistent results. DdPCR results on cfDNA are highly dependent on multiple factors during preanalytical sample workup, which need to be addressed during the development of this diagnostic tool for cancer diagnostics in the future. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

[Biometric method for the description of the head of an unrecognized corpse for the purpose of personality individualization and identification].

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Zviagin, V N; Galitskaia, O I; Negasheva, M A

2012-01-01

We have determined absolute dimensions of the head and the relationship between the dimensions of its selected parts. The study enrolled adult subjects (mostly of Russian ethnicity) at the age from 17 to 22 years (1108 men and 1153 women). We calculated the normal values for the estimation of real dimensional characteristics and the frequency of their occurrence in the population. The proposed approach makes it possible to reliably identify the dimensional features of human appearance in terms of the quantitative verbal description (categories 1-5) and to reveal its most characteristic features. The results of this biometric study of the heads of unrecognized corpses obtained by the specially developed technology may be used in operational and search investigations, in the procedure of corpse identification, and forensic medical personality identification of a missing subject.

Privacy and equality in diagnostic genetic testing.

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Nyrhinen, Tarja; Hietala, Marja; Puukka, Pauli; Leino-Kilpi, Helena

2007-05-01

This study aimed to determine the extent to which the principles of privacy and equality were observed during diagnostic genetic testing according to views held by patients or child patients' parents (n = 106) and by staff (n = 162) from three Finnish university hospitals. The data were collected through a structured questionnaire and analysed using the SAS 8.1 statistical software. In general, the two principles were observed relatively satisfactorily in clinical practice. According to patients/parents, equality in the post-analytic phase and, according to staff, privacy in the pre-analytic phase, involved the greatest ethical problems. The two groups differed in their views concerning pre-analytic privacy. Although there were no major problems regarding the two principles, the differences between the testing phases require further clarification. To enhance privacy protection and equality, professionals need to be given more genetics/ethics training, and patients individual counselling by genetics units staff, giving more consideration to patients' world-view, the purpose of the test and the test result.

Optimization of analytical and pre-analytical conditions for MALDI-TOF-MS human urine protein profiles.

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Calvano, C D; Aresta, A; Iacovone, M; De Benedetto, G E; Zambonin, C G; Battaglia, M; Ditonno, P; Rutigliano, M; Bettocchi, C

2010-03-11

Protein analysis in biological fluids, such as urine, by means of mass spectrometry (MS) still suffers for insufficient standardization in protocols for sample collection, storage and preparation. In this work, the influence of these variables on healthy donors human urine protein profiling performed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was studied. A screening of various urine sample pre-treatment procedures and different sample deposition approaches on the MALDI target was performed. The influence of urine samples storage time and temperature on spectral profiles was evaluated by means of principal component analysis (PCA). The whole optimized procedure was eventually applied to the MALDI-TOF-MS analysis of human urine samples taken from prostate cancer patients. The best results in terms of detected ions number and abundance in the MS spectra were obtained by using home-made microcolumns packed with hydrophilic-lipophilic balance (HLB) resin as sample pre-treatment method; this procedure was also less expensive and suitable for high throughput analyses. Afterwards, the spin coating approach for sample deposition on the MALDI target plate was optimized, obtaining homogenous and reproducible spots. Then, PCA indicated that low storage temperatures of acidified and centrifuged samples, together with short handling time, allowed to obtain reproducible profiles without artifacts contribution due to experimental conditions. Finally, interesting differences were found by comparing the MALDI-TOF-MS protein profiles of pooled urine samples of healthy donors and prostate cancer patients. The results showed that analytical and pre-analytical variables are crucial for the success of urine analysis, to obtain meaningful and reproducible data, even if the intra-patient variability is very difficult to avoid. It has been proven how pooled urine samples can be an interesting way to make easier the comparison between

Multi-locus phylogeny reveals instances of mitochondrial introgression and unrecognized diversity in Kenyan barbs (Cyprininae: Smiliogastrini).

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Schmidt, Ray C; Bart, Henry L; Nyingi, Wanja Dorothy

2017-06-01

The phylogenetics and taxonomic status of small African barbs (Cyprininae: Smiliogastrini) remains unresolved despite the recent decision to elevate the genus name Enteromius for the group. The main barrier to understanding the origin of African small barbs and evolutionary relationships within the group is the poor resolution of phylogenies published to date. These phylogenies usually rely on mitochondrial markers and have limited taxon sampling. Here we investigate the phylogenetic relationships of small barbs of Kenya utilizing cytochrome b, Growth Hormone (GH) intron 2, and RAG1 markers from multiple populations of many species in the region. This multi-locus study produced well-supported phylogenies and revealed additional issues that complicate understanding the relationships among East African barbs. We observed widespread mtDNA introgression within the Kenyan barbs, highlighting the need to include nuclear markers in phylogenetic studies of the group. The GH intron 2 resolved heterospecific individuals and aided in inferring the species level phylogeny. The study reveals unrecognized diversity within the group, including within species reported to occur throughout East Africa, and it provides the groundwork for future taxonomic work in the region and across Africa. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and validation of dried matrix spot sampling for the quantitative determination of amyloid β peptides in cerebrospinal fluid.

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Delaby, Constance; Gabelle, Audrey; Meynier, Philippe; Loubiere, Vincent; Vialaret, Jérôme; Tiers, Laurent; Ducos, Jacques; Hirtz, Christophe; Lehmann, Sylvain

2014-05-01

The use of dried blood spots on filter paper is well documented as an affordable and practical alternative to classical venous sampling for various clinical needs. This technique has indeed many advantages in terms of collection, biological safety, storage, and shipment. Amyloid β (Aβ) peptides are useful cerebrospinal fluid (CSF) biomarkers for Alzheimer disease diagnosis. However, Aβ determination is hindered by preanalytical difficulties in terms of sample collection and stability in tubes. We compared the quantification of Aβ peptides (1-40, 1-42, and 1-38) by simplex and multiplex ELISA, following either a standard operator method (liquid direct quantification) or after spotting CSF onto dried matrix paper card. The use of dried matrix spot (DMS) overcame preanalytical problems and allowed the determination of Aβ concentrations that were highly commutable (Bland-Altman) with those obtained using CSF in classical tubes. Moreover, we found a positive and significant correlation (r2=0.83, Pearson coefficient p=0.0329) between the two approaches. This new DMS method for CSF represents an interesting alternative that increases the quality and efficiency in preanalytics. This should enable the better exploitation of Aβ analytes for Alzheimer's diagnosis.

Environmental hazards of waste disposal patterns--a multimethod study in an unrecognized Bedouin village in the Negev area of Israel.

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Meallem, Ilana; Garb, Yaakov; Cwikel, Julie

2010-01-01

The Bedouin of the Negev region of Israel are a formerly nomadic, indigenous, ethnic minority, of which 40% currently live in unrecognized villages without organized, solid waste disposal. This study, using both quantitative and qualitative methods, explored the transition from traditional rubbish production and disposal to current uses, the current composition of rubbish, methods of waste disposal, and the extent of exposure to waste-related environmental hazards in the village of Um Batim. The modern, consumer lifestyle produced both residential and construction waste that was dumped very close to households. Waste was tended to by women who predominantly used backyard burning for disposal, exposing villagers to corrosive, poisonous, and dangerously flammable items at these burn sites. Village residents expressed a high level of concern over environmental hazards, yet no organized waste disposal or environmental hazards reduction was implemented.

Blood sample collection and patient identification demand improvement: a questionnaire study of preanalytical practices in hospital wards and laboratories.

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Wallin, Olof; Söderberg, Johan; Van Guelpen, Bethany; Stenlund, Hans; Grankvist, Kjell; Brulin, Christine

2010-09-01

Scand J Caring Sci; 2010; 24; 581-591 
 Blood sample collection and patient identification demand improvement: a questionnaire study of preanalytical practices in hospital wards and laboratories   Most errors in venous blood testing result from human mistakes occurring before the sample reach the laboratory.   To survey venous blood sampling (VBS) practices in hospital wards and to compare practices with hospital laboratories.   Staff in two hospitals (all wards) and two hospital laboratories (314 respondents, response rate 94%), completed a questionnaire addressing issues relevant to the collection of venous blood samples for clinical chemistry testing.   The findings suggest that instructions for patient identification and the collection of venous blood samples were not always followed. For example, 79% of the respondents reported the undesirable practice (UDP) of not always using wristbands for patient identification. Similarly, 87% of the respondents noted the UDP of removing venous stasis after the sampling is finished. Compared with the ward staff, a significantly higher proportion of the laboratory staff reported desirable practices regarding the collection of venous blood samples. Neither education nor the existence of established sampling routines was clearly associated with VBS practices among the ward staff.   The results of this study, the first of its kind, suggest that a clinically important risk of error is associated with VBS in the surveyed wards. Most important is the risk of misidentification of patients. Quality improvement of blood sample collection is clearly needed, particularly in hospital wards. © 2009 The Authors. Journal compilation © 2009 Nordic College of Caring Science.

Improving Histopathology Laboratory Productivity: Process Consultancy and A3 Problem Solving

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Kutsal YÖRÜKOĞLU

2017-01-01

Full Text Available Objective: The ISO 17020 quality program has been run in our pathology laboratory for four years to establish an action plan for correction and prevention of identified errors. In this study, we aimed to evaluate the errors that we could not identify through ISO 17020 and/or solve by means of process consulting. Process consulting is carefully intervening in a group or team to help it to accomplish its goals. Material and Method: The A3 problem solving process was run under the leadership of a ‘workflow, IT and consultancy manager’. An action team was established consisting of technical staff. A root cause analysis was applied for target conditions, and the 6-S method was implemented for solution proposals. Applicable proposals were activated and the results were rated by six-sigma analysis. Non-applicable proposals were reported to the laboratory administrator. Results: A mislabelling error was the most complained issue triggering all pre-analytical errors. There were 21 non-value added steps grouped in 8 main targets on the fish bone graphic (transporting, recording, moving, individual, waiting, over-processing, over-transaction and errors. Unnecessary redundant requests, missing slides, archiving issues, redundant activities, and mislabelling errors were proposed to be solved by improving visibility and fixing spaghetti problems. Spatial re-organization, organizational marking, re-defining some operations, and labeling activities raised the six sigma score from 24% to 68% for all phases. Operational transactions such as implementation of a pathology laboratory system was suggested for long-term improvement. Conclusion: Laboratory management is a complex process. Quality control is an effective method to improve productivity. Systematic checking in a quality program may not always find and/or solve the problems. External observation may reveal crucial indicators about the system failures providing very simple solutions.

Improving Histopathology Laboratory Productivity: Process Consultancy and A3 Problem Solving.

Science.gov (United States)

Yörükoğlu, Kutsal; Özer, Erdener; Alptekin, Birsen; Öcal, Cem

2017-01-01

The ISO 17020 quality program has been run in our pathology laboratory for four years to establish an action plan for correction and prevention of identified errors. In this study, we aimed to evaluate the errors that we could not identify through ISO 17020 and/or solve by means of process consulting. Process consulting is carefully intervening in a group or team to help it to accomplish its goals. The A3 problem solving process was run under the leadership of a 'workflow, IT and consultancy manager'. An action team was established consisting of technical staff. A root cause analysis was applied for target conditions, and the 6-S method was implemented for solution proposals. Applicable proposals were activated and the results were rated by six-sigma analysis. Non-applicable proposals were reported to the laboratory administrator. A mislabelling error was the most complained issue triggering all pre-analytical errors. There were 21 non-value added steps grouped in 8 main targets on the fish bone graphic (transporting, recording, moving, individual, waiting, over-processing, over-transaction and errors). Unnecessary redundant requests, missing slides, archiving issues, redundant activities, and mislabelling errors were proposed to be solved by improving visibility and fixing spaghetti problems. Spatial re-organization, organizational marking, re-defining some operations, and labeling activities raised the six sigma score from 24% to 68% for all phases. Operational transactions such as implementation of a pathology laboratory system was suggested for long-term improvement. Laboratory management is a complex process. Quality control is an effective method to improve productivity. Systematic checking in a quality program may not always find and/or solve the problems. External observation may reveal crucial indicators about the system failures providing very simple solutions.

Prevalence of unrecognized diabetes, prediabetes and metabolic syndrome in patients undergoing elective percutaneous coronary intervention.

Science.gov (United States)

Balakrishnan, Revathi; Berger, Jeffrey S; Tully, Lisa; Vani, Anish; Shah, Binita; Burdowski, Joseph; Fisher, Edward; Schwartzbard, Arthur; Sedlis, Steven; Weintraub, Howard; Underberg, James A; Danoff, Ann; Slater, James A; Gianos, Eugenia

2015-09-01

Diabetes mellitus (DM) and metabolic syndrome are important targets for secondary prevention in cardiovascular disease. However, the prevalence in patients undergoing elective percutaneous coronary intervention is not well defined. We aimed to analyse the prevalence and characteristics of patients undergoing percutaneous coronary intervention with previously unrecognized prediabetes, diabetes and metabolic syndrome. Data were collected from 740 patients undergoing elective percutaneous coronary intervention between November 2010 and March 2013 at a tertiary referral center. Prevalence of DM and prediabetes was evaluated using Haemoglobin A1c (A1c ≥ 6.5% for DM, A1c 5.7-6.4% for prediabetes). A modified definition was used for metabolic syndrome [three or more of the following criteria: body mass index ≥30 kg/m2; triglycerides ≥ 150 mg/dL; high density lipoprotein prediabetes at time of percutaneous coronary intervention. Overall, 54.9% met criteria for metabolic syndrome (69.2% of patients with DM and 45.8% of patients without DM). Among patients undergoing elective percutaneous coronary intervention, a substantial number were identified with a new DM, prediabetes, and/or metabolic syndrome. Routine screening for an abnormal glucometabolic state at the time of revascularization may be useful for identifying patients who may benefit from additional targeting of modifiable risk factors. Copyright © 2015 John Wiley & Sons, Ltd.

New approaches to old scattering problems

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Goldberg, Joshua David

This thesis is broken into two parts corresponding to the research done before and after the death of Roger Dashen. The first part addresses the problem of high frequency scattering from flat objects. A new formalism, developed by Dashen and Wurmser, is applied to the two dimensional problem of scattering from a soft infinite strip. It is seen that the cross section can be related to a quantity, termed the divergence coefficient, which describes the behavior of the field near the edges. A simple expression for the divergence coefficient and the scattering cross section is derived which, in contrast to traditional results, is uniformly valid in the high frequency limit. The basic procedure is to first express the divergence coefficient in a series form involving Mathieu functions, approximating the terms in this series by their uniform WKB representation, and using the Poisson sum formula to convert the WKB-based series to a more rapidly converging series of integrals which can be evaluated asymptotically. The result is a new expression for the scattering cross section which is compared with previously obtained results. The second part addresses a specific problem in the field of wave propagation in random media: computing the average field for the case of a plane wave incident on a region with a weakly fluctuating sound speed. A review of the existing mathematical methods for treating this problem in both the small and large-scale fluctuation cases is given. In the small-scale regime, previously unrecognized problems with the closure theory are discussed and numerical results are given which illustrate the role played by backscattering in this type of propagation. In the large-scale regime, a new mathematical approach, analogous to the renormalization technique, is described and used to derive a new expression for the mean field valid in this limit. This result is compared with the traditional expressions for this quantity.

Comparison of Pre-Analytical FFPE Sample Preparation Methods and Their Impact on Massively Parallel Sequencing in Routine Diagnostics

Science.gov (United States)

Heydt, Carina; Fassunke, Jana; Künstlinger, Helen; Ihle, Michaela Angelika; König, Katharina; Heukamp, Lukas Carl; Schildhaus, Hans-Ulrich; Odenthal, Margarete; Büttner, Reinhard; Merkelbach-Bruse, Sabine

2014-01-01

Over the last years, massively parallel sequencing has rapidly evolved and has now transitioned into molecular pathology routine laboratories. It is an attractive platform for analysing multiple genes at the same time with very little input material. Therefore, the need for high quality DNA obtained from automated DNA extraction systems has increased, especially to those laboratories which are dealing with formalin-fixed paraffin-embedded (FFPE) material and high sample throughput. This study evaluated five automated FFPE DNA extraction systems as well as five DNA quantification systems using the three most common techniques, UV spectrophotometry, fluorescent dye-based quantification and quantitative PCR, on 26 FFPE tissue samples. Additionally, the effects on downstream applications were analysed to find the most suitable pre-analytical methods for massively parallel sequencing in routine diagnostics. The results revealed that the Maxwell 16 from Promega (Mannheim, Germany) seems to be the superior system for DNA extraction from FFPE material. The extracts had a 1.3–24.6-fold higher DNA concentration in comparison to the other extraction systems, a higher quality and were most suitable for downstream applications. The comparison of the five quantification methods showed intermethod variations but all methods could be used to estimate the right amount for PCR amplification and for massively parallel sequencing. Interestingly, the best results in massively parallel sequencing were obtained with a DNA input of 15 ng determined by the NanoDrop 2000c spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). No difference could be detected in mutation analysis based on the results of the quantification methods. These findings emphasise, that it is particularly important to choose the most reliable and constant DNA extraction system, especially when using small biopsies and low elution volumes, and that all common DNA quantification techniques can be used for

Comparison of pre-analytical FFPE sample preparation methods and their impact on massively parallel sequencing in routine diagnostics.

Directory of Open Access Journals (Sweden)

Carina Heydt

Full Text Available Over the last years, massively parallel sequencing has rapidly evolved and has now transitioned into molecular pathology routine laboratories. It is an attractive platform for analysing multiple genes at the same time with very little input material. Therefore, the need for high quality DNA obtained from automated DNA extraction systems has increased, especially to those laboratories which are dealing with formalin-fixed paraffin-embedded (FFPE material and high sample throughput. This study evaluated five automated FFPE DNA extraction systems as well as five DNA quantification systems using the three most common techniques, UV spectrophotometry, fluorescent dye-based quantification and quantitative PCR, on 26 FFPE tissue samples. Additionally, the effects on downstream applications were analysed to find the most suitable pre-analytical methods for massively parallel sequencing in routine diagnostics. The results revealed that the Maxwell 16 from Promega (Mannheim, Germany seems to be the superior system for DNA extraction from FFPE material. The extracts had a 1.3-24.6-fold higher DNA concentration in comparison to the other extraction systems, a higher quality and were most suitable for downstream applications. The comparison of the five quantification methods showed intermethod variations but all methods could be used to estimate the right amount for PCR amplification and for massively parallel sequencing. Interestingly, the best results in massively parallel sequencing were obtained with a DNA input of 15 ng determined by the NanoDrop 2000c spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA. No difference could be detected in mutation analysis based on the results of the quantification methods. These findings emphasise, that it is particularly important to choose the most reliable and constant DNA extraction system, especially when using small biopsies and low elution volumes, and that all common DNA quantification techniques can

Flow cytometry for feline lymphoma: a retrospective study about pre-analytical factors possibly affecting the quality of samples

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Serena Bernardi

2017-05-01

Full Text Available Introduction Flow cytometry (FC is an increasingly required technique on which veterinary oncologists rely to have an accurate, fast, minimally invasive lymphoma or leukemia diagnosis. FC has been studied and applied with great results in canine oncology, whereas in feline oncology the use of this technique is still to be experienced. This is mainly due to a supposed discomfort in sampling, because of the high prevalence of intra-abdominal lymphomas. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis. Methods 97 consecutive samples of suspected feline lymphoma were retrospectively selected from the authors’ institution FC database. The referring veterinarians were recalled and interrogated about several different variables, including signalling, features of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of being finally processed for FC. Results None of the investigated variables significantly influenced the quality of the submitted samples, but the needle size, with 21G needles providing the highest cellularity (Table 1. Notably, the samples quality did not vary between peripheral and intra-abdominal lesions. Sample cellularity alone influenced the likelihood of being processed. About a half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling. Conclusions FC can be safely applied to cases of suspected feline lymphomas, even for intra-abdominal lesions. 21G needle should be preferred for sampling. This study provides the bases for the spread of this minimally invasive, fast and cost-effective technique in feline medicine.

Flow cytometry for feline lymphoma: a retrospective study regarding pre-analytical factors possibly affecting the quality of samples.

Science.gov (United States)

Martini, Valeria; Bernardi, Serena; Marelli, Priscilla; Cozzi, Marzia; Comazzi, Stefano

2018-06-01

Objectives Flow cytometry (FC) is becoming increasingly popular among veterinary oncologists for the diagnosis of lymphoma or leukaemia. It is accurate, fast and minimally invasive. Several studies of FC have been carried out in canine oncology and applied with great results, whereas there is limited knowledge and use of this technique in feline patients. This is mainly owing to the high prevalence of intra-abdominal lymphomas in this species and the difficulty associated with the diagnostic procedures needed to collect the sample. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis. Methods Ninety-seven consecutive samples of suspected feline lymphoma were retrospectively selected from the authors' institution's FC database. The referring veterinarians were contacted and interviewed about several different variables, including signalment, appearance of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of it being finally processed for FC. Results Sample cellularity is a major factor in the likelihood of the sample being processed. Moreover, sample cellularity was significantly influenced by the needle size, with 21 G needles providing the highest cellularity. Notably, the sample cellularity and the likelihood of being processed did not vary between peripheral and intra-abdominal lesions. Approximately half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling). Conclusions and relevance FC can be safely applied to cases of suspected feline lymphomas, including intra-abdominal lesions. A 21 G needle should be preferred for sampling. This study provides the basis for

Effectiveness of Preanalytic Practices on Contamination and Diagnostic Accuracy of Urine Cultures: a Laboratory Medicine Best Practices Systematic Review and Meta-analysis

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Franek, Jacob; Leibach, Elizabeth K.; Weissfeld, Alice S.; Kraft, Colleen S.; Sautter, Robert L.; Baselski, Vickie; Rodahl, Debra; Peterson, Edward J.; Cornish, Nancy E.

2015-01-01

SUMMARY Background. Urinary tract infection (UTI) in the United States is the most common bacterial infection, and urine cultures often make up the largest portion of workload for a hospital-based microbiology laboratory. Appropriately managing the factors affecting the preanalytic phase of urine culture contributes significantly to the generation of meaningful culture results that ultimately affect patient diagnosis and management. Urine culture contamination can be reduced with proper techniques for urine collection, preservation, storage, and transport, the major factors affecting the preanalytic phase of urine culture. Objectives. The purposes of this review were to identify and evaluate preanalytic practices associated with urine specimens and to assess their impact on the accuracy of urine culture microbiology. Specific practices included collection methods for men, women, and children; preservation of urine samples in boric acid solutions; and the effect of refrigeration on stored urine. Practice efficacy and effectiveness were measured by two parameters: reduction of urine culture contamination and increased accuracy of patient diagnosis. The CDC Laboratory Medicine Best Practices (LMBP) initiative's systematic review method for assessment of quality improvement (QI) practices was employed. Results were then translated into evidence-based practice guidelines. Search strategy. A search of three electronic bibliographic databases (PubMed, SCOPUS, and CINAHL), as well as hand searching of bibliographies from relevant information sources, for English-language articles published between 1965 and 2014 was conducted. Selection criteria. The search contained the following medical subject headings and key text words: urinary tract infections, UTI, urine/analysis, urine/microbiology, urinalysis, specimen handling, preservation, biological, preservation, boric acid, boric acid/borate, refrigeration, storage, time factors, transportation, transport time, time delay

ASVCP quality assurance guidelines: control of preanalytical and analytical factors for hematology for mammalian and nonmammalian species, hemostasis, and crossmatching in veterinary laboratories.

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Vap, Linda M; Harr, Kendal E; Arnold, Jill E; Freeman, Kathleen P; Getzy, Karen; Lester, Sally; Friedrichs, Kristen R

2012-03-01

In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and provides recommendations for control of preanalytical and analytical factors related to hematology for mammalian and nonmammalian species, hemostasis testing, and crossmatching and is adapted from sections 1.1 and 2.3 (mammalian hematology), 1.2 and 2.4 (nonmammalian hematology), 1.5 and 2.7 (hemostasis testing), and 1.6 and 2.8 (crossmatching) of the complete guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. © 2012 American Society for Veterinary Clinical Pathology.

The long-term risk of recognized and unrecognized myocardial infarction for depression in older men.

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Jovanova, O; Luik, A I; Leening, M J G; Noordam, R; Aarts, N; Hofman, A; Franco, O H; Dehghan, A; Tiemeier, H

2016-07-01

The association between myocardial infarction (MI) and depression is well described. Yet, the underlying mechanisms are unclear and the contribution of psychological factors is uncertain. We aimed to determine the risk of recognized (RMI) and unrecognized (UMI) myocardial infections on depression, as both have a similar impact on cardiovascular health but differ in psychological epiphenomena. Participants of the Rotterdam Study, 1823 men aged ⩾55 years, were followed for the occurrence of depression. RMI and UMI were ascertained using electrocardiography and medical history at baseline. We determined the strength of the association of RMI and UMI with mortality, and we studied the relationship of RMI and UMI with depressive symptoms and the occurrence of major depression. The risk of mortality was similar in men with RMI [adjusted hazard ratio (aHR) 1.71, 95% confidence interval (CI) 1.45-2.03] and UMI (aHR 1.58, 95% CI 1.27-1.97). Men with RMI had on average [unstandardized regression coefficient (B) 1.14, 95% CI 0.07-2.21] higher scores for depressive symptoms. By contrast, we found no clear association between UMI and depressive symptoms (B 0.55, 95% CI -0.51 to 1.62) in men. Analysis including occurrence of major depression as the outcome were consistent with the pattern of association. The discrepant association of RMI and UMI with mortality compared to depression suggests that the psychological burden of having experienced an MI contributes to the long-term risk of depression.

Practical reporting times for environmental samples

International Nuclear Information System (INIS)

Bayne, C.K.; Schmoyer, D.D.; Jenkins, R.A.

1993-02-01

Preanalytical holding times for environmental samples are specified because chemical and physical characteristics may change between sampling and chemical analysis. For example, the Federal Register prescribes a preanalytical holding time of 14 days for volatile organic compounds in soil stored at 4 degrees C. The American Society for Testing Materials (ASTM) uses a more technical definition that the preanalytical holding time is the day when the analyte concentration for an environmental sample falls below the lower 99% confidence interval on the analyte concentration at day zero. This study reviews various holding time definitions and suggest a new preanalytical holding time approach using acceptable error rates for measuring an environmental analyte. This practical reporting time (PRT) approach has been applied to nineteen volatile organic compounds and four explosives in three environmental soil samples. A PRT nomograph of error rates has been developed to estimate the consequences of missing a preanalytical holding time. This nomograph can be applied to a large class of analytes with concentrations that decay linearly or exponentially with time regardless of sample matrices and storage conditions

Practical reporting times for environmental samples

Energy Technology Data Exchange (ETDEWEB)

Bayne, C.K.; Schmoyer, D.D.; Jenkins, R.A.

1993-02-01

Preanalytical holding times for environmental samples are specified because chemical and physical characteristics may change between sampling and chemical analysis. For example, the Federal Register prescribes a preanalytical holding time of 14 days for volatile organic compounds in soil stored at 4{degrees}C. The American Society for Testing Materials (ASTM) uses a more technical definition that the preanalytical holding time is the day when the analyte concentration for an environmental sample falls below the lower 99% confidence interval on the analyte concentration at day zero. This study reviews various holding time definitions and suggest a new preanalytical holding time approach using acceptable error rates for measuring an environmental analyte. This practical reporting time (PRT) approach has been applied to nineteen volatile organic compounds and four explosives in three environmental soil samples. A PRT nomograph of error rates has been developed to estimate the consequences of missing a preanalytical holding time. This nomograph can be applied to a large class of analytes with concentrations that decay linearly or exponentially with time regardless of sample matrices and storage conditions.

The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up

Energy Technology Data Exchange (ETDEWEB)

Themudo, Raquel; Johansson, Lars; Ebeling-Barbier, Charlotte; Ahlstroem, Haakan; Bjerner, Tomas [Uppsala University Hospital, Department of Radiology, Uppsala (Sweden); Lind, Lars [Uppsala University Hospital, Department of Medicine, Uppsala (Sweden)

2017-02-15

In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time. From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium. In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75. The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time. (orig.)

MS-based monitoring of proteolytic decay of synthetic reporter peptides for quality control of plasma and serum specimens.

Science.gov (United States)

Findeisen, Peter; Thumfart, Jörg Oliver; Costina, Victor; Hofheinz, Ralf; Neumaier, Michael

2013-09-01

To determine the preanalytical quality of serum and plasma by monitoring the time-dependent ex vivo decay of a synthetic reporter peptide (RP) with liquid chromatography/mass spectrometry (LC/MS). Serum and plasma specimens were spiked with the RP and proteolytic fragments were monitored with LC/MS at different preanalytical time points ranging from 2 to 24 hours after blood withdrawal. The concentration of fragments changed in a time-dependent manner, and respective peptide profiles were used to classify specimens according to their preanalytical time span. Classification accuracy was high, with values always above 0.89 for areas under receiver operating characteristic curves. This "proteomics degradation clock" can be used to estimate the preanalytical quality of serum and plasma and might have impact on quality control procedures of biobanking repositories.

Identification errors in the blood transfusion laboratory: a still relevant issue for patient safety.

Science.gov (United States)

Lippi, Giuseppe; Plebani, Mario

2011-04-01

Remarkable technological advances and increased awareness have both contributed to decrease substantially the uncertainty of the analytical phase, so that the manually intensive preanalytical activities currently represent the leading sources of errors in laboratory and transfusion medicine. Among preanalytical errors, misidentification and mistransfusion are still regarded as a considerable problem, posing serious risks for patient health and carrying huge expenses for the healthcare system. As such, a reliable policy of risk management should be readily implemented, developing through a multifaceted approach to prevent or limit the adverse outcomes related to transfusion reactions from blood incompatibility. This strategy encompasses root cause analysis, compliance with accreditation requirements, strict adherence to standard operating procedures, guidelines and recommendations for specimen collection, use of positive identification devices, rejection of potentially misidentified specimens, informatics data entry, query host communication, automated systems for patient identification and sample labeling and an adequate and safe environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Success of torsional correction surgery after failed surgeries for patellofemoral pain and instability

OpenAIRE

Stevens, Peter M.; Gililland, Jeremy M.; Anderson, Lucas A.; Mickelson, Jennifer B.; Nielson, Jenifer; Klatt, Joshua W.

2013-01-01

Torsional deformities of the femur and/or tibia often go unrecognized in adolescents and adults who present with anterior knee pain, and patellar maltracking or instability. While open and arthroscopic surgical techniques have evolved to address these problems, unrecognized torsion may compromise the outcomes of these procedures. We collected a group of 16 consecutive patients (23 knees), with mean age of 17, who had undergone knee surgery before torsion was recognized and subsequently treate...

The cobas p 630 instrument: a dedicated pre-analytic solution to optimize COBAS® AmpliPrep/COBAS® TaqMan® system workflow and turn-around-time.

Science.gov (United States)

Vallefuoco, L; Sorrentino, R; Spalletti Cernia, D; Colucci, G; Portella, G

2012-12-01

The cobas p 630, a fully automated pre-analytical instrument for primary tube handling recently introduced to complete the Cobas(®) TaqMan systems portfolio, was evaluated in conjunction with: the COBAS(®) AmpliPrep/COBAS(®) TaqMan HBV Test, v2.0, COBAS(®) AmpliPrep/COBAS(®) TaqMan HCV Test, v1.0 and COBAS(®) AmpliPrep/COBAS(®) TaqMan HIV Test, v2.0. The instrument performance in transferring samples from primary to secondary tubes, its impact in improving COBAS(®) AmpliPrep/COBAS(®) TaqMan workflow and hands-on reduction and the risk of possible cross-contamination were assessed. Samples from 42 HBsAg positive, 42 HCV and 42 HIV antibody (Ab) positive patients as well as 21 healthy blood donors were processed with or without automated primary tubes. HIV, HCV and HBsAg positive samples showed a correlation index of 0.999, 0.987 and of 0.994, respectively. To assess for cross-contamination, high titer HBV DNA positive samples, HCV RNA and HIV RNA positive samples were distributed in the cobas p 630 in alternate tube positions, adjacent to negative control samples within the same rack. None of the healthy donor samples showed any reactivity. Based on these results, the cobas p 630 can improve workflow and sample tracing in laboratories performing molecular tests, and reduce turnaround time, errors, and risks. Copyright © 2012 Elsevier B.V. All rights reserved.

Interdisciplinarity at the Human-Environment Interface

DEFF Research Database (Denmark)

Rasmussen, Kjeld; Arler, Finn

2010-01-01

Current environmental problems increasingly call for research - as well as education - which crosses the traditional divides between well-established scientific disciplines and between natural science, technical sciences, social sciences and the humanities. This paper addresses the issue of what...... and methodological nature. Particular attention is paid to differences between disciplines in the way they 'explain' and 'interpret' phenomena and regularities, and in 'world-views', pre-analytic assumptions and in time scales....

A diverse group of previously unrecognized human rhinoviruses are common causes of respiratory illnesses in infants.

Directory of Open Access Journals (Sweden)

Wai-Ming Lee

2007-10-01

Full Text Available Human rhinoviruses (HRVs are the most prevalent human pathogens, and consist of 101 serotypes that are classified into groups A and B according to sequence variations. HRV infections cause a wide spectrum of clinical outcomes ranging from asymptomatic infection to severe lower respiratory symptoms. Defining the role of specific strains in various HRV illnesses has been difficult because traditional serology, which requires viral culture and neutralization tests using 101 serotype-specific antisera, is insensitive and laborious.To directly type HRVs in nasal secretions of infants with frequent respiratory illnesses, we developed a sensitive molecular typing assay based on phylogenetic comparisons of a 260-bp variable sequence in the 5' noncoding region with homologous sequences of the 101 known serotypes. Nasal samples from 26 infants were first tested with a multiplex PCR assay for respiratory viruses, and HRV was the most common virus found (108 of 181 samples. Typing was completed for 101 samples and 103 HRVs were identified. Surprisingly, 54 (52.4% HRVs did not match any of the known serotypes and had 12-35% nucleotide divergence from the nearest reference HRVs. Of these novel viruses, 9 strains (17 HRVs segregated from HRVA, HRVB and human enterovirus into a distinct genetic group ("C". None of these new strains could be cultured in traditional cell lines.By molecular analysis, over 50% of HRV detected in sick infants were previously unrecognized strains, including 9 strains that may represent a new HRV group. These findings indicate that the number of HRV strains is considerably larger than the 101 serotypes identified with traditional diagnostic techniques, and provide evidence of a new HRV group.

Unrecognized Ingestion of Toxoplasma gondii Oocysts Leads to Congenital Toxoplasmosis and Causes Epidemics in North America

Science.gov (United States)

Boyer, Kenneth; Hill, Dolores; Mui, Ernest; Wroblewski, Kristen; Karrison, Theodore; Dubey, J. P.; Sautter, Mari; Noble, A. Gwendolyn; Withers, Shawn; Swisher, Charles; Heydemann, Peter; Hosten, Tiffany; Babiarz, Jane; Lee, Daniel

2011-01-01

(See the Editorial Commentary by Linn, on pages 1090–1.) Background. Congenital toxoplasmosis presents as severe, life-altering disease in North America. If mothers of infants with congenital toxoplasmosis could be identified by risks, it would provide strong support for educating pregnant women about risks, to eliminate this disease. Conversely, if not all risks are identifiable, undetectable risks are suggested. A new test detecting antibodies to sporozoites demonstrated that oocysts were the predominant source of Toxoplasma gondii infection in 4 North American epidemics and in mothers of children in the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS). This novel test offered the opportunity to determine whether risk factors or demographic characteristics could identify mothers infected with oocysts. Methods. Acutely infected mothers and their congenitally infected infants were evaluated, including in-person interviews concerning risks and evaluation of perinatal maternal serum samples. Results. Fifty-nine (78%) of 76 mothers of congenitally infected infants in NCCCTS had primary infection with oocysts. Only 49% of these mothers identified significant risk factors for sporozoite acquisition. Socioeconomic status, hometown size, maternal clinical presentations, and ethnicity were not reliable predictors. Conclusions. Undetected contamination of food and water by oocysts frequently causes human infections in North America. Risks are often unrecognized by those infected. Demographic characteristics did not identify oocyst infections. Thus, although education programs describing hygienic measures may be beneficial, they will not suffice to prevent the suffering and economic consequences associated with congenital toxoplasmosis. Only a vaccine or implementation of systematic serologic testing of pregnant women and newborns, followed by treatment, will prevent most congenital toxoplasmosis in North America. PMID:22021924

Using mHealth technologies to improve the identification of behavioral health problems in urban primary care settings.

Science.gov (United States)

Staeheli, Martha; Aseltine, Robert H; Schilling, Elizabeth; Anderson, Daren; Gould, Bruce

2017-01-01

Behavioral health disorders remain under recognized and under diagnosed among urban primary care patients. Screening patients for such problems is widely recommended, yet is challenging to do in a brief primary care encounter, particularly for this socially and medically complex patient population. In 2013, intervention patients at an urban Connecticut primary clinic were screened for post-traumatic stress disorder, depression, and risky drinking (n = 146) using an electronic tablet-based screening tool. Screening data were compared to electronic health record data from control patients (n = 129) to assess differences in the prevalence of behavioral health problems, rates of follow-up care, and the rate of newly identified cases in the intervention group. Results from logistic regressions indicated that both groups had similar rates of disorder at baseline. Patients in the intervention group were five times more likely to be identified with depression (p Post-traumatic stress disorder was virtually unrecognized among controls but was observed in 23% of the intervention group (p behavioral health problems identified in the intervention group were new cases. Follow-up rates were significantly higher in the intervention group relative to controls, but were low overall. This tablet-based electronic screening tool identified significantly higher rates of behavioral health disorders than have been previously reported for this patient population. Electronic risk screening using patient-reported outcome measures offers an efficient approach to improving the identification of behavioral health problems and improving rates of follow-up care.

POSTPARTUM DEPRESSION – THE CENTRAL PROBLEM OF MENTAL HEALTH OF EARLY MOTHERHOOD

Directory of Open Access Journals (Sweden)

N. A. Kornetov

2015-01-01

Full Text Available Perinatal mental health of the mother occupies a central position in healthcare, the same as caring for a newborn baby. Maternal depression is the lead pathology of postpartum period. Despite the high prevalence and importance to the overall development of children, most cases of depression are unappreciated, unrecognized and untreated. Inattention to issues which are related to physical and mental health of women, leads to severe negative social and economic consequences for society. Statistical comparison of the total number of pregnant women, the number of births in the United States in 2007, excluding cases of fetal loss, including still-births and miscarriages with similar Russian data allowed to calculate the approximate prevalence of postpartum depression in the same period. Presumable probability of postpartum depression is 15% in different regions of the world, and the diagnostic criteria of DSM-IV for postpartum depression are representative for comparison. Considering these assumptions, according to 2007 each year about 260,000 out of 1 mln. 600,000 of Russian women in childbirth may suffer from post-natal depression. The results have a probabilistic character. For the mothers the consequences of unrecognized and untreated depression after childbirth are the most frequent. It should be seen as a depressive episode or recurrent depressive disorder which has a singular coloring due to the appearance in the peak period of reproductive age of women. Postpartum depression may increase the possibility of occurrence of relapse of a depressive disorder as well as the transition to a state of chronic depression. Alcoholism or drug use is a common complication of depression; the risk of suicide increases, especially during the time of reducing the severity of the most severe symptoms of depression, though it is below the prevalence of suicide among the population. Particular attention should be paid to such symptoms as instability in mood and

Managing Chronic Pain in People with Learning Disabilities: A Case Study

Science.gov (United States)

Lewis, Sarah; Bell, Dorothy; Gillanders, David

2007-01-01

Chronic pain is a prevalent, under-diagnosed problem in the learning disability population. This is in part due to communication problems, unrecognized pain behaviours and the effects of medication. As a consequence, chronic pain often goes untreated and causes ongoing distress. This paper initially describes the main research that has been…

Traditional Knowledge and industrial development

DEFF Research Database (Denmark)

Hansen, Anne Merrild; Tejsner, Pelle; Egede, Parnuna Petrina

2016-01-01

of education. Some of this is based in social and health problems, but this group also includes very competent, skillful and well- functioning people. Their problem is, that their skills are acquired in informal ways and for that reason invisible and un-recognized by the job market. The lack of appreciation...

Cancer classification in the genomic era: five contemporary problems.

Science.gov (United States)

Song, Qingxuan; Merajver, Sofia D; Li, Jun Z

2015-10-19

Classification is an everyday instinct as well as a full-fledged scientific discipline. Throughout the history of medicine, disease classification is central to how we develop knowledge, make diagnosis, and assign treatment. Here, we discuss the classification of cancer and the process of categorizing cancer subtypes based on their observed clinical and biological features. Traditionally, cancer nomenclature is primarily based on organ location, e.g., "lung cancer" designates a tumor originating in lung structures. Within each organ-specific major type, finer subgroups can be defined based on patient age, cell type, histological grades, and sometimes molecular markers, e.g., hormonal receptor status in breast cancer or microsatellite instability in colorectal cancer. In the past 15+ years, high-throughput technologies have generated rich new data regarding somatic variations in DNA, RNA, protein, or epigenomic features for many cancers. These data, collected for increasingly large tumor cohorts, have provided not only new insights into the biological diversity of human cancers but also exciting opportunities to discover previously unrecognized cancer subtypes. Meanwhile, the unprecedented volume and complexity of these data pose significant challenges for biostatisticians, cancer biologists, and clinicians alike. Here, we review five related issues that represent contemporary problems in cancer taxonomy and interpretation. (1) How many cancer subtypes are there? (2) How can we evaluate the robustness of a new classification system? (3) How are classification systems affected by intratumor heterogeneity and tumor evolution? (4) How should we interpret cancer subtypes? (5) Can multiple classification systems co-exist? While related issues have existed for a long time, we will focus on those aspects that have been magnified by the recent influx of complex multi-omics data. Exploration of these problems is essential for data-driven refinement of cancer classification

An Irish outbreak of New Delhi metallo-β-lactamase (NDM)-1 carbapenemase-producing Enterobacteriaceae: increasing but unrecognized prevalence.

Science.gov (United States)

O'Connor, C; Cormican, M; Boo, T W; McGrath, E; Slevin, B; O'Gorman, A; Commane, M; Mahony, S; O'Donovan, E; Powell, J; Monahan, R; Finnegan, C; Kiernan, M G; Coffey, J C; Power, L; O'Connell, N H; Dunne, C P

2016-12-01

Carbapenemase-producing Enterobacteriaceae (CPE) may cause healthcare-associated infections with high mortality rates. New Delhi metallo-β-lactamase-1 (NDM-1) is among the most recently discovered carbapenemases. To report the first outbreak of NDM-1 CPE in Ireland, including microbiological and epidemiological characteristics, and assessing the impact of infection prevention and control measures. This was a retrospective microbiological and epidemiological review. Cases were defined as patients with a CPE-positive culture. Contacts were designated as roommates or ward mates. This outbreak involved 10 patients with a median age of 71 years (range: 45-90), located in three separate but affiliated healthcare facilities. One patient was infected (the index case); the nine others were colonized. Nine NDM-1-producing Klebsiella pneumoniae, an NDM-1-producing Escherichia coli and a K. pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae were detected between week 24, 2014 and week 37, 2014. Pulsed-field gel electrophoresis demonstrated similarity. NDM-1-positive isolates were meropenem resistant with minimum inhibitory concentrations (MICs) ranging from 12 to 32 μg/mL. All were tigecycline susceptible (MICs ≤1 μg/mL). One isolate was colistin resistant (MIC 4.0 μg/mL; mcr-1 gene not detected). In 2015, four further NDM-1 isolates were detected. The successful management of this outbreak was achieved via the prompt implementation of enhanced infection prevention and control practices to prevent transmission. These patients did not have a history of travel outside of Ireland, but several had frequent hospitalizations in Ireland, raising concerns regarding the possibility of increasing but unrecognized prevalence of NDM-1 and potential decline in value of travel history as a marker of colonization risk. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Pre-Test and Post-Test Applications to Shape the Education of Phlebotomists in A Quality Management Program: An Experience in A Training Hospital

Directory of Open Access Journals (Sweden)

Aykal Güzin

2016-09-01

Full Text Available Background: After the introduction of modern laboratory instruments and information systems, preanalytic phase is the new field of battle. Errors in preanalytical phase account for approximately half of total errors in clinical laboratory. The objective of this study was to share an experience of an education program that was believed to be successful in decreasing the number of rejected samples received from the Emergency Department (ED.

[Modal failure analysis and effects in the detection of errors in the transport of samples to the clinical laboratory].

Science.gov (United States)

Parés-Pollán, L; Gonzalez-Quintana, A; Docampo-Cordeiro, J; Vargas-Gallego, C; García-Álvarez, G; Ramos-Rodríguez, V; Diaz Rubio-García, M P

2014-01-01

Owing to the decrease in values of biochemical glucose parameter in some samples from external extraction centres, and the risk this implies to patient safety; it was decided to apply an adaptation of the «Health Services Failure Mode and Effects Analysis» (HFMEA) to manage risk during the pre-analytical phase of sample transportation from external centres to clinical laboratories. A retrospective study of glucose parameter was conducted during two consecutive months. The analysis was performed in its different phases: to define the HFMEA topic, assemble the team, graphically describe the process, conduct a hazard analysis, design the intervention and indicators, and identify a person to be responsible for ensuring completion of each action. The results of glucose parameter in one of the transport routes, were significantly lower (P=.006). The errors and potential causes of this problem were analysed, and criteria of criticality and detectability were applied (score≥8) in the decision tree. It was decided to: develop a document management system; reorganise extractions and transport routes in some centres; quality control of the sample container ice-packs, and the time and temperature during transportation. This work proposes quality indicators for controlling time and temperature of transported samples in the pre-analytical phase. Periodic review of certain laboratory parameters can help to detect problems in transporting samples. The HFMEA technique is useful for the clinical laboratory. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.

Pre-Test and Post-Test Applications to Shape the Education of Phlebotomists in A Quality Management Program: An Experience in a Training Hospital

OpenAIRE

Aykal, G?zin; Ke?apli, Mustafa; Aydin, ?zg?r; Esen, Hatice; Ye?in, Ay?enur; G?ng?r, Faruk; Yilmaz, Necat

2016-01-01

Summary Background After the introduction of modern laboratory instruments and information systems, preanalytic phase is the new field of battle. Errors in preanalytical phase account for approximately half of total errors in clinical laboratory. The objective of this study was to share an experience of an education program that was believed to be successful in decreasing the number of rejected samples received from the Emergency Department (ED). Methods An education program about laboratory ...

[Biochemical markers of bone remodeling: pre-analytical variations and guidelines for their use. SFBC (Société Française de Biologie Clinique) Work Group. Biochemical markers of bone remodeling].

Science.gov (United States)

Garnero, P; Bianchi, F; Carlier, M C; Genty, V; Jacob, N; Kamel, S; Kindermans, C; Plouvier, E; Pressac, M; Souberbielle, J C

2000-01-01

Biochemical markers of bone turnover have been developed over the past 20 years that are more specific for bone tissue than conventional ones such as total alkaline phosphatase and urinary hydroxyproline. They have been widely used in clinical research and in clinical trials of new therapies as secondary end points of treatment efficacy. Most of the interest has been devoted to their use in postmenopausal osteoporosis, a condition characterized by subtle modifications of bone metabolism that cannot be detected readily by conventional markers of bone turnover. Although several recent studies have suggested that biochemical markers may be used for the management of the individual patient in routine clinical practice, this has not been clearly defined and is a matter of debate. Because of the crucial importance to clarify this issue, the Société Francaise de Biologie Clinique prompted an expert committee to summarize the available data and to make recommendations. The following paper includes a review on the biochemical and analytical aspects of the markers of bone formation and resorption and on the sources of variability such as sex, age, menstrual cycle, pregnancy and lactation, physical activity, seasonal variation and effects of diseases and treatments. We will also describe the effects of pre-analytical factors on the measurements of the different markers. Finally based on that review, we will make practical recommendations for the use of these markers in order to minimize the variability of the measurements and improve the clinical interpretation of the data.

Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies.

Science.gov (United States)

Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

2017-09-01

Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive Behavioral Therapy for Insomnia in Older Adults

Science.gov (United States)

Belanger, Lynda; LeBlanc, Melanie; Morin, Charles M.

2012-01-01

Insomnia is associated with significant morbidity and is often a persistent problem, particularly in older adults. It is important to attend to this complaint and not assume that it will remit spontaneously. In many cases, unfortunately, insomnia remains unrecognized and untreated, often because it is presumed that insomnia is an inevitable…

"If It Doesn't Happen in Liverpool..."

Science.gov (United States)

Hopkins, Adam

1977-01-01

In 1974, the Parliamentary Select Committee on Race Relations and Immigration criticized Liverpools' education system, for leaving immigrants and their descendants at a disadvantage in school and out, for allowing their problems to go unrecognized in an atmosphere of self-satisfaction. Author just visited Liverpool, to find out how those…

Contact dermatitis is an unrecognized problem in the construction industry: Comparison of four different assessment methods.

Science.gov (United States)

Timmerman, Johan G; Heederik, Dick; Spee, Ton; van Rooy, Frits G; Krop, Esmeralda J M; Rustemeyer, Thomas; Smit, Lidwien A M

2017-10-01

A high contact dermatitis symptoms prevalence has been observed in Dutch construction workers. Contact dermatitis was diagnosed by an expert panel using questionnaire data and photographs of 751 subjects' hands. A subset was evaluated by two occupational physicians. Their diagnoses were compared to those of the expert panel. In addition, two self-reported questionnaire-based assessment methods were compared to the expert panel evaluation. Associations between contact dermatitis and determinants were assessed using log-binomial regression analysis. Contact dermatitis prevalence was high: 61.4% (expert panel's diagnosis) and 32.9% (self-reported). Agreement between occupational physicians and the expert panel was low but increased after training. Washing hands with solvents and performing job-related tasks at home were related to contact dermatitis. Contact dermatitis prevalence among construction workers is high. Recognition of contact dermatitis by occupational physicians is poor but can be improved by training. Awareness of skin disorders should be raised. © 2017 Wiley Periodicals, Inc.

Contact dermatitis is an unrecognized problem in the construction industry : Comparison of four different assessment methods

NARCIS (Netherlands)

Timmerman, Johan G; Heederik, Dick; Spee, Ton; van Rooy, Frits G; Krop, Esmeralda J M; Rustemeyer, Thomas; Smit, Lidwien A M

2017-01-01

BACKGROUND: A high contact dermatitis symptoms prevalence has been observed in Dutch construction workers. METHODS: Contact dermatitis was diagnosed by an expert panel using questionnaire data and photographs of 751 subjects' hands. A subset was evaluated by two occupational physicians. Their

The usefulness and feasibility of a screening instrument to identify psychosocial problems in patients receiving curative radiotherapy: a process evaluation

International Nuclear Information System (INIS)

Braeken, Anna PBM; Kempen, Gertrudis IJM; Eekers, Daniëlle; Gils, Francis CJM van; Houben, Ruud MA; Lechner, Lilian

2011-01-01

Psychosocial problems in cancer patients are often unrecognized and untreated due to the low awareness of the existence of these problems or pressures of time. The awareness of the need to identify psychosocial problems in cancer patients is growing and has affected the development of screening instruments. This study explored the usefulness and feasibility of using a screening instrument (SIPP: Screening Inventory of Psychosocial Problems) to identify psychosocial problems in cancer patients receiving curative radiotherapy treatment (RT). The study was conducted in a radiation oncology department in the Netherlands. Several methods were used to document the usefulness and feasibility of the SIPP. Data were collected using self-report questionnaires completed by seven radiotherapists and 268 cancer patients. Regarding the screening procedure 33 patients were offered to consult a psychosocial care provider (e.g. social worker, psychologist) during the first consultation with their radiotherapist. Of these patients, 31 patients suffered from at least sub-clinical symptoms and two patients hardly suffered from any symptoms. Patients' acceptance rate 63.6% (21/33) was high. Patients were positive about the content of the SIPP (mean scores vary from 8.00 to 8.88, out of a range between 0 and 10) and about the importance of discussing items of the SIPP with their radiotherapist (mean score = 7.42). Radiotherapists' perspectives about the contribution of the SIPP to discuss the different psychosocial problems were mixed (mean scores varied from 3.17 to 4.67). Patients were more positive about discussing items of the SIPP if the radiotherapists had positive attitudes towards screening and discussing psychosocial problems. The screening procedure appeared to be feasible in a radiotherapy department. In general, patients' perspectives were at least moderate. Radiotherapists considered the usefulness and feasibility of the SIPP generally to be lower, but their

Congenital rubella syndrome in Haiti (Short communication).

Science.gov (United States)

Golden, Nancy; Kempker, Russell; Khator, Parul; Summerlee, Robert; Fournier, Arthur

2002-10-01

To determine if there is an unrecognized problem of congenital rubella syndrome (CRS) in Haiti, a country without a national rubella immunization program. During March 2001 and June 2001, screening physicals were conducted on approximately 80 orphans at three orphanages in Haiti that accept disabled children. Children were classified as probable CRS cases based on established clinical criteria. Photo documentation of findings was obtained whenever possible. Six children met the criteria for probable CRS. Using data from surrounding Caribbean countries and from the United States of America prior to rubella immunization, we estimated that there are between 163 and 440 new cases of CRS per year in Haiti. CRS exists in Haiti, but its presence is generally unrecognized. A national rubella immunization policy should be considered.

Evaluation of analytical errors in a clinical chemistry laboratory: a 3 year experience.

Science.gov (United States)

Sakyi, As; Laing, Ef; Ephraim, Rk; Asibey, Of; Sadique, Ok

2015-01-01

Proficient laboratory service is the cornerstone of modern healthcare systems and has an impact on over 70% of medical decisions on admission, discharge, and medications. In recent years, there is an increasing awareness of the importance of errors in laboratory practice and their possible negative impact on patient outcomes. We retrospectively analyzed data spanning a period of 3 years on analytical errors observed in our laboratory. The data covered errors over the whole testing cycle including pre-, intra-, and post-analytical phases and discussed strategies pertinent to our settings to minimize their occurrence. We described the occurrence of pre-analytical, analytical and post-analytical errors observed at the Komfo Anokye Teaching Hospital clinical biochemistry laboratory during a 3-year period from January, 2010 to December, 2012. Data were analyzed with Graph Pad Prism 5(GraphPad Software Inc. CA USA). A total of 589,510 tests was performed on 188,503 outpatients and hospitalized patients. The overall error rate for the 3 years was 4.7% (27,520/58,950). Pre-analytical, analytical and post-analytical errors contributed 3.7% (2210/58,950), 0.1% (108/58,950), and 0.9% (512/58,950), respectively. The number of tests reduced significantly over the 3-year period, but this did not correspond with a reduction in the overall error rate (P = 0.90) along with the years. Analytical errors are embedded within our total process setup especially pre-analytical and post-analytical phases. Strategic measures including quality assessment programs for staff involved in pre-analytical processes should be intensified.

Immunohistochemistry practices of cytopathology laboratories: a survey of participants in the College of American Pathologists Nongynecologic Cytopathology Education Program.

Science.gov (United States)

Fischer, Andrew H; Schwartz, Mary R; Moriarty, Ann T; Wilbur, David C; Souers, Rhona; Fatheree, Lisa; Booth, Christine N; Clayton, Amy C; Kurtyz, Daniel F I; Padmanabhan, Vijayalakshmi; Crothers, Barbara A

2014-09-01

Immunohistochemistry (IHC) is important for cytology but poses special challenges because preanalytic conditions may differ from the conditions of IHC-positive controls. To broadly survey cytology laboratories to quantify preanalytic platforms for cytology IHC and identify problems with particular platforms or antigens. To discover how validation guidelines for HER2 testing have affected cytology. A voluntary survey of cytology IHC practices was sent to 1899 cytology laboratories participating in the College of American Pathologists Nongynecologic Cytopathology Education Program in the fall of 2009. A total of 818 laboratories (43%) responded to the survey by April 2010. Three hundred fourty-five of 791 respondents (44%) performed IHC on cytology specimens. Seventeen different fixation and processing platforms prior to antibody reaction were reported. A total of 59.2% of laboratories reported differences between the platforms for cytology specimens and positive controls, but most (155 of 184; 84%) did not alter antibody dilutions or antigen retrieval for cytology IHC. When asked to name 2 antibodies for which staining conditions differed between cytology and surgical samples, there were 18 responses listing 14 antibodies. A total of 30.6% of laboratories performing IHC offered HER2 testing before publication of the 2007 College of American Pathologists/American Society of Clinical Oncologists guidelines, compared with 33.6% afterward, with increased performance of testing by reference laboratories. Three laboratories validated a nonformalin HER2 platform. The platforms for cytology IHC and positive controls differ for most laboratories, yet conditions are uncommonly adjusted for cytology specimens. Except for the unsuitability of air-dried smears for HER2 testing, the survey did not reveal evidence of systematic problems with any antibody or platform.

Clinically unrecognized pulmonary aspiration during gastrointestinal endoscopy with sedation: A potential pitfall interfering the performance of 18F-FDG PET for cancer screening

International Nuclear Information System (INIS)

Hsieh, Te-Chun; Wu, Yu-Chin; Ding, Hueisch-Jy; Wang, Chih-Hsiu; Yen, Kuo-Yang; Sun, Shung-Shung; Yeh, Jun-Jun; Kao, Chia-Hung

2011-01-01

Purpose: We found several cases with unexpected pulmonary abnormalities on the 18 F-FDG PET scan after the gastrointestinal endoscopy with sedation during a compact health check-up course, interfering the interpretations of 18 F-FDG PET scan for cancer screening. The current studies aimed to analyze the incidence and the clinical relevance of this pulmonary finding. Materials and methods: From June to December 2009, 127 subjects undergoing the sequential gastrointestinal endoscopy with sedation and 18 F-FDG PET scan within 48 h as part of routine health check-up were retrospectively enrolled in this study. The incidence of abnormal pulmonary findings and their SUV max of FDG were calculated and correlated with the clinical manifestations. Results: Five subjects had abnormal 18 F-FDG PET findings but pulmonary symptoms were only found in 2. The SUV max did not seem to reflect the severity of pulmonary symptoms or the need of intervention. Although the incidence of unrecognized pulmonary aspiration featuring inflammation detected by the 18 F-FDG PET scan was high (3.94%, 5/127), the incidence of events needed intervention remained low (0.79%, 1/127), similar to those previously reported literatures. Conclusions: Although higher incidence of pulmonary aspiration in this study, it probably reflects the better sensitivity of 18 F-FDG PET for inflammation. The low incidence of clinical events needed intervention may still reflect the safety of sedation used for gastrointestinal endoscopy. Proper arrangement of the sequential examinations if subjects need both gastrointestinal endoscopy with sedation and 18 F-FDG PET is important to reduce the interference degrading the performance of 18 F-FDG PET in cancer screening, diagnosis or staging.

Obstructive Sleep Apnea and Postoperative Complications in Patients Undergoing Coronary Artery Bypass Graft Surgery: A Need for Preventive Strategies

Directory of Open Access Journals (Sweden)

Babak Amra

2014-01-01

Conclusions: Obstructive sleep apnea is frequent, but unrecognized among patients undergoing CABG. In these patients, OSA is associated with prolonged intubation duration. Preventing these problems may be possible by early diagnosis and management of OSA in cardiac surgery patients. Further studies with larger sample of patients and longer follow-ups are required in this regard.

Congenital rubella syndrome in Haiti

Directory of Open Access Journals (Sweden)

Golden Nancy

2002-01-01

Full Text Available Objective. To determine if there is an unrecognized problem of congenital rubella syndrome (CRS in Haiti, a country without a national rubella immunization program. Methods. During March 2001 and June 2001, screening physicals were conducted on approximately 80 orphans at three orphanages in Haiti that accept disabled children. Children were classified as probable CRS cases based on established clinical criteria. Photo documentation of findings was obtained whenever possible. Results. Six children met the criteria for probable CRS. Using data from surrounding Caribbean countries and from the United States of America prior to rubella immunization, we estimated that there are between 163 and 440 new cases of CRS per year in Haiti. Conclusions. CRS exists in Haiti, but its presence is generally unrecognized. A national rubella immunization policy should be considered.

Congenital rubella syndrome in Haiti

Directory of Open Access Journals (Sweden)

Nancy Golden

2002-10-01

Full Text Available Objective. To determine if there is an unrecognized problem of congenital rubella syndrome (CRS in Haiti, a country without a national rubella immunization program. Methods. During March 2001 and June 2001, screening physicals were conducted on approximately 80 orphans at three orphanages in Haiti that accept disabled children. Children were classified as probable CRS cases based on established clinical criteria. Photo documentation of findings was obtained whenever possible. Results. Six children met the criteria for probable CRS. Using data from surrounding Caribbean countries and from the United States of America prior to rubella immunization, we estimated that there are between 163 and 440 new cases of CRS per year in Haiti. Conclusions. CRS exists in Haiti, but its presence is generally unrecognized. A national rubella immunization policy should be considered.

Erythema after laser skin resurfacing.

Science.gov (United States)

Ruiz-Esparza, J; Barba Gomez, J M; Gomez de la Torre, O L; David, L

1998-01-01

Erythema after laser skin resurfacing is seen by many as a necessary evil in order to get good results from the procedure. A critical review of widely accepted concepts may lead to diminishing the length of postoperative erythema in patients undergoing laser resurfacing. The authors report on two previously unrecognized factors in the causation of this problem.

Drone inflight mixing of biochemical samples.

Science.gov (United States)

Katariya, Mayur; Chung, Dwayne Chung Kim; Minife, Tristan; Gupta, Harshit; Zahidi, Alifa Afiah Ahmad; Liew, Oi Wah; Ng, Tuck Wah

2018-03-15

Autonomous systems for sample transport to the laboratory for analysis can be improved in terms of timeliness, cost and error mitigation in the pre-analytical testing phase. Drones have been reported for outdoor sample transport but incorporating devices on them to attain homogenous mixing of reagents during flight to enhance sample processing timeliness is limited by payload issues. It is shown here that flipping maneuvers conducted with quadcopters are able to facilitate complete and gentle mixing. This capability incorporated during automated sample transport serves to address an important factor contributing to pre-analytical variability which ultimately impacts on test result reliability. Copyright © 2018 Elsevier Inc. All rights reserved.

Unrecognized myocardial infarctions assessed by cardiovascular magnetic resonance are associated with the severity of the stenosis in the supplying coronary artery.

Science.gov (United States)

Hammar, Per; Nordenskjöld, Anna M; Lindahl, Bertil; Duvernoy, Olov; Ahlström, Håkan; Johansson, Lars; Hadziosmanovic, Nermin; Bjerner, Tomas

2015-11-19

A previous study has shown an increased prevalence of late gadolinium enhancement cardiovascular magnetic resonance (LGE CMR) detected unrecognized myocardial infarction (UMI) with increasing extent and severity of coronary artery disease. However, the coronary artery disease was evaluated on a patient level assuming normal coronary anatomy. Therefore, the aims of the present study were to investigate the prevalence of UMI identified by LGE CMR imaging in patients with stable angina pectoris and no known previous myocardial infarction; and to investigate whether presence of UMI is associated with stenotic lesions in the coronary artery supplying the segment of the myocardium in which the UMI is located, using coronary angiography to determine the individual coronary anatomy in each patient. In this prospective multicenter study, we included patients with stable angina pectoris and without prior myocardial infarction, scheduled for coronary angiography. A LGE CMR examination was performed prior to the coronary angiography. The study cohort consisted of 235 patients (80 women, 155 men) with a mean age of 64.8 years. UMIs were found in 25% of patients. There was a strong association between stenotic lesions (≥70% stenosis) in a coronary artery and the presence of an UMI in the myocardial segments supplied by the stenotic artery; it was significantly more likely to have an UMI downstream a stenosis ≥ 70% as compared to < 70% (OR 5.1, CI 3.1-8.3, p < 0.0001). 56% of the UMIs were located in the inferior and infero-lateral myocardial segments, despite predominance for stenotic lesions in the left anterior descending artery. UMI is common in patients with stable angina and the results indicate that the majority of the UMIs are of ischemic origin due to severe coronary atherosclerosis. In contrast to what is seen in recognized myocardial infarctions, UMIs are predominately located in the inferior and infero-lateral myocardial segments. The PUMI study is

Typed Linear Chain Conditional Random Fields and Their Application to Intrusion Detection

Science.gov (United States)

Elfers, Carsten; Horstmann, Mirko; Sohr, Karsten; Herzog, Otthein

Intrusion detection in computer networks faces the problem of a large number of both false alarms and unrecognized attacks. To improve the precision of detection, various machine learning techniques have been proposed. However, one critical issue is that the amount of reference data that contains serious intrusions is very sparse. In this paper we present an inference process with linear chain conditional random fields that aims to solve this problem by using domain knowledge about the alerts of different intrusion sensors represented in an ontology.

[Management of pre-analytical nonconformities].

Science.gov (United States)

Berkane, Z; Dhondt, J L; Drouillard, I; Flourié, F; Giannoli, J M; Houlbert, C; Surgat, P; Szymanowicz, A

2010-12-01

The main nonconformities enumerated to facilitate consensual codification. In each case, an action is defined: refusal to realize the examination with request of a new sample, request of information or correction, results cancellation, nurse or physician information. A traceability of the curative, corrective and preventive actions is needed. Then, methodology and indicators are proposed to assess nonconformity and to follow the quality improvements. The laboratory information system can be used instead of dedicated software. Tools for the follow-up of nonconformities scores are proposed. Finally, we propose an organization and some tools allowing the management and control of the nonconformities occurring during the pre-examination phase.

Evaluation of quality indicators in a laboratory supporting tertiary cancer care facilities in India.

Science.gov (United States)

Kumar, Savitha Anil; Jayanna, Prashanth; Prabhudesai, Shilpa; Kumar, Ajai

2014-01-01

To collect and tabulate errors and nonconformities in the preanalytical, analytical, and postanalytical process phases in a diagnostic clinical laboratory that supports a super-specialty cancer center in India, and identify areas of potential improvement in patient services. We collected data from our laboratory during a period of 24 months. Departments in the study included clinical biochemistry, hematology, clinical pathology, microbiology and serology, surgical pathology, and molecular pathology. We had initiated quality assessment based on international standards in our laboratory in 2010, with the aim of obtaining accreditation by national and international governing bodies. We followed the guidelines specified by International Organization for Standardization (ISO) 15189:2007 to identify noncompliant elements of our processes. Among a total of 144,030 specimens that our referral laboratory received during the 2-year period of our study, we uncovered an overall error rate for all 3 process phases of 1.23%; all of our error rates closely approximated the results from our peer institutions. Errors were most common in the preanalytical phase in both years of study; preanalytical- and postanalytical-phase errors constituted more than 90% of all errors. Further improvements are warranted in laboratory services and are contingent on adequate training and interdepartmental communication and cooperation. Copyright© by the American Society for Clinical Pathology (ASCP).

[The birth of metapsychology. On the current interpretation of "Entwurf einer Psychologie" (1895)].

Science.gov (United States)

Schmidt-Hellerau, C

1995-12-01

The general attitude towards Entwurf einer Psychologie (1895) is to reckon it among Freud's pre-analytic writings, i.e. that part of his work later more or less disowned by the author. Schmidt-Hellerau challenges this assessment by Freud and many of his successors, demonstrating that the Entwurf can legitimately be regarded as a meta-theory resolving - or skirting- the old classification problem of whether psychoanalysis is a science or an art by connecting the hitherto dissociated spheres of soma and psyche and conceptualizing of physiological and psychological processes. See thus, the Entwurf reveals itself as a theoretical document of astonishing modernity and undiminished relevance in that it records Freud's ambitious attempt to overcome the mind-body schism and the divide between neurophysiology and psychology. And it is precisely this problem, the author contends, which Freud's later metapsychology--and the controversies it has aroused--revolves around.

Nocturnal Wakefulness as a Previously Unrecognized Risk Factor for Suicide.

Science.gov (United States)

Perlis, Michael L; Grandner, Michael A; Brown, Gregory K; Basner, Mathias; Chakravorty, Subhajit; Morales, Knashawn H; Gehrman, Philip R; Chaudhary, Ninad S; Thase, Michael E; Dinges, David F

2016-06-01

Suicide is a major public health problem and the 10th leading cause of death in the United States. The identification of modifiable risk factors is essential for reducing the prevalence of suicide. Recently, it has been shown that insomnia and nightmares significantly increase the risk for suicidal ideation, attempted suicide, and death by suicide. While both forms of sleep disturbance may independently confer risk, and potentially be modifiable risk factors, it is also possible that simply being awake at night represents a specific vulnerability for suicide. The present analysis evaluates the frequency of completed suicide per hour while taking into account the percentage of individuals awake at each hour. Archival analyses were conducted estimating the time of fatal injury using the National Violent Death Reporting System for 2003-2010 and the proportion of the American population awake per hour across the 24-hour day using the American Time Use Survey. The mean ± SD incident rate from 06:00-23:59 was 2.2% ± 0.7%, while the mean ± SD incident rate from 00:00-05:59 was 10.3% ± 4.9%. The maximum incident rate was from 02:00-02:59 (16.3%). Hour-by-hour observed values differed from those that would be expected by chance (P < .001), and when 6-hour blocks were examined, the observed frequency at night was 3.6 times higher than would be expected by chance (P < .001). Being awake at night confers greater risk for suicide than being awake at other times of the day, suggesting that disturbances of sleep or circadian neurobiology may potentiate suicide risk. © Copyright 2016 Physicians Postgraduate Press, Inc.

Medical devices made into weapons by prisoners: an unrecognized risk.

Science.gov (United States)

Hayden, J W; Laney, C; Kellermann, A L

1995-12-01

The alteration of a knee immobilizer into a sharp weapon by a prisoner prompted us to survey neighboring penal institutions to determine the frequency of such events. We mailed a nine-item survey to all detention facilities in Tennessee, Arkansas, and Mississippi. A second survey was sent to nonresponding institutions 6 weeks after the initial mailing. The Regional Medical Center at Memphis, the designated facility for evaluation and treatment of prisoners from the county jail and state penitentiary. Survey respondents included 25 state penitentiaries, 31 county jails, 1 state minimum-security facility, 1 state maximum-security facility, 1 work-release center, 1 county detention center for drunken-driving offenders, and 1 federal penitentiary. Of the 81 institutions surveyed, 77% responded to one of the two mailings. Forty percent responded in the affirmative when asked whether stolen or unauthorized medical equipment from outside their institutions had been discovered among inmates. When respondents were questioned as to whether medical equipment, prescribed or not, had been used or altered in a criminal manner, 34% responded "yes." Medications and medical appliances were listed in the responses. A survey of 81 local and neighboring penal institutions in a three-state area revealed that the illicit use of medicine and medical devices by prisoners is a legitimate safety concern of prison personnel and health care workers when medical care for inmates must be sought outside the security of their institutions. The modification of medical equipment into weapons by incarcerated patients, although clearly recognized as a security and safety problem by police authorities, appears to be unappreciated by health care workers providing episodic care to inmates.

Explaining the Mind: Problems, Problems

OpenAIRE

Harnad, Stevan

2001-01-01

The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

Kantian epistemology as an alternative to heroic astronomy

Science.gov (United States)

McLaughlin, W. I.

Theoretical and observational methods in astronomy have advanced to a point where certain of their outcomes are difficult to comprehend with the traditional categories of human knowledge. The philosophical discipline of epistemology, the theory of knowledge, is used here to address four current problems in observational astronomy, exobiology, cosmology, and quantum mechanics. The problems are united by an epistemological content which, when unrecognized, has resulted in some heroic solutions of an ad hoc nature. Immanuel Kant's critical philosophy is employed because his work is consistent with basic attitudes in present-day physics and biology.

Kantian epistemology as an alternative to heroic astronomy

Science.gov (United States)

Mclaughlin, W. I.

1985-01-01

Theoretical and observational methods in astronomy have advanced to a point where certain of their outcomes are difficult to comprehend with the traditional categories of human knowledge. The philosophical discipline of epistemology, the theory of knowledge, is used here to address four current problems in observational astronomy, exobiology, cosmology, and quantum mechanics. The problems are united by an epistemological content which, when unrecognized, has resulted in some heroic solutions of an ad hoc nature. Kant's critical philosophy is employed because his work is consistent with basic attitudes in present-day physics and biology.

Iatrogenic stomach perforation complicating unrecognized ...

African Journals Online (AJOL)

We report a case of 21-year-old male patient with traumatic diaphragmatic herniation of the stomach that is misdiagnosed as a hemo-pneumothorax with the resulting insertion of a chest tube causing iatrogenic perforation of the stomach and draining of gastric content into the pleural cavity. An emergency thoracotomy was ...

Pre-analytical and analytical validations and clinical applications of a miniaturized, simple and cost-effective solid phase extraction combined with LC-MS/MS for the simultaneous determination of catecholamines and metanephrines in spot urine samples.

Science.gov (United States)

Li, Xiaoguang Sunny; Li, Shu; Kellermann, Gottfried

2016-10-01

It remains a challenge to simultaneously quantify catecholamines and metanephrines in a simple, sensitive and cost-effective manner due to pre-analytical and analytical constraints. Herein, we describe such a method consisting of a miniaturized sample preparation and selective LC-MS/MS detection by the use of second morning spot urine samples. Ten microliters of second morning urine sample were subjected to solid phase extraction on an Oasis HLB microplate upon complexation with phenylboronic acid. The analytes were well-resolved on a Luna PFP column followed by tandem mass spectrometric detection. Full validation and suitability of spot urine sampling and biological variation were investigated. The extraction recovery and matrix effect are 74.1-97.3% and 84.1-119.0%, respectively. The linearity range is 2.5-500, 0.5-500, 2.5-1250, 2.5-1250 and 0.5-1250ng/mL for norepinephrine, epinephrine, dopamine, normetanephrine and metanephrine, respectively. The intra- and inter-assay imprecisions are ≤9.4% for spiked quality control samples, and the respective recoveries are 97.2-112.5% and 95.9-104.0%. The Deming regression slope is 0.90-1.08, and the mean Bland-Altman percentage difference is from -3.29 to 11.85 between a published and proposed method (n=50). A correlation observed for the spot and 24h urine collections is significant (n=20, p<0.0001, r: 0.84-0.95, slope: 0.61-0.98). No statistical differences are found in day-to-day biological variability (n=20). Reference intervals are established for an apparently healthy population (n=88). The developed method, being practical, sensitive, reliable and cost-effective, is expected to set a new stage for routine testing, basic research and clinical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Advancing haemostasis automation--successful implementation of robotic centrifugation and sample processing in a tertiary service hospital.

Science.gov (United States)

Sédille-Mostafaie, Nazanin; Engler, Hanna; Lutz, Susanne; Korte, Wolfgang

2013-06-01

Laboratories today face increasing pressure to automate operations due to increasing workloads and the need to reduce expenditure. Few studies to date have focussed on the laboratory automation of preanalytical coagulation specimen processing. In the present study, we examined whether a clinical chemistry automation protocol meets the preanalytical requirements for the analyses of coagulation. During the implementation of laboratory automation, we began to operate a pre- and postanalytical automation system. The preanalytical unit processes blood specimens for chemistry, immunology and coagulation by automated specimen processing. As the production of platelet-poor plasma is highly dependent on optimal centrifugation, we examined specimen handling under different centrifugation conditions in order to produce optimal platelet deficient plasma specimens. To this end, manually processed models centrifuged at 1500 g for 5 and 20 min were compared to an automated centrifugation model at 3000 g for 7 min. For analytical assays that are performed frequently enough to be targets for full automation, Passing-Bablok regression analysis showed close agreement between different centrifugation methods, with a correlation coefficient between 0.98 and 0.99 and a bias between -5% and +6%. For seldom performed assays that do not mandate full automation, the Passing-Bablok regression analysis showed acceptable to poor agreement between different centrifugation methods. A full automation solution is suitable and can be recommended for frequent haemostasis testing.

Standardization and optimization of fluorescence in situ hybridization (FISH) for HER-2 assessment in breast cancer: A single center experience.

Science.gov (United States)

Bogdanovska-Todorovska, Magdalena; Petrushevska, Gordana; Janevska, Vesna; Spasevska, Liljana; Kostadinova-Kunovska, Slavica

2018-05-20

Accurate assessment of human epidermal growth factor receptor 2 (HER-2) is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE) tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples) and DAKO Histology FISH Accessory Kit (30 samples). The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing) affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70); the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.

Detection of delirium by nurses among long-term care residents with dementia

OpenAIRE

Voyer, Philippe; Richard, Sylvie; Doucet, Lise; Danjou, Christine; Carmichael, Pierre-Hugues

2008-01-01

Abstract Background Delirium is a prevalent problem in long-term care (LTC) facilities where advanced age and cognitive impairment represent two important risk factors for this condition. Delirium is associated with numerous negative outcomes including increased morbidity and mortality. Despite its clinical importance, delirium often goes unrecognized by nurses. Although rates of nurse-detected delirium have been studied among hospitalized older patients, this issue has been largely neglected...

Delta check for blood groups: A step ahead in blood safety

Directory of Open Access Journals (Sweden)

Raj Nath Makroo

2017-01-01

Conclusion: Delta checks proved to be an effective tool for detecting blood group errors and prevention of accidental mismatched blood transfusions. Preanalytical errors in patient identification or sample labeling were the most frequent.

No Problem? No Research, Little Learning ... Big Problem!

Directory of Open Access Journals (Sweden)

Fernando Ornelas Marques

2012-06-01

Full Text Available The motivation to carry out this study stemmed from the generalized perception that nowadays youth lacks the skills for the 21st century. Especially the high-level competences like critical thinking, problem solving and autonomy. Several tools can help to improve these competences (e.g. the SCRATCH programming language, but, as researchers and educators, we are mostly concerned with the skill to recognize problems. What if we do not find problems to solve? What if we do not even feel the need to find or solve problems? The problem is to recognize the problem; the next step is to equate the problem; finally we have to feel the need to solve it. No need? No invention. Recognizing a problem is probably the biggest problem of everyday life, because we are permanently faced with problems (many ill-defined problems, which we need to identify, equate and solve.

Class and Home Problems: Optimization Problems

Science.gov (United States)

Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard

2011-01-01

Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…

Tumor markers: applications and recommendations. New IZOTOPE products

International Nuclear Information System (INIS)

Gyenes, Ana Rosa

2016-01-01

At work aspects are discussed: Tumor markers; New products IZOTOP; Measuring principle of IRMA kits for tumor markers; Guidelines and Recommendations for the use of tumor markers. pre-analytical, post-analytical and Quality control recommendations are given

The interactive effect of paternal problem drinking and maternal problem drinking on adolescent internalizing problems.

Science.gov (United States)

Ohannessian, Christine McCauley

2015-11-01

This study examined the effects of both paternal problem drinking and maternal problem drinking on adolescent internalizing problems (depression and anxiety symptomatology). Surveys were administered to 566 10th and 11th grade students from the Mid-Atlantic region of the U.S. in the spring of 2007 and again in the spring of 2008. Although significant main effects were not observed, significant interactions were found between paternal problem drinking and maternal problem drinking for internalizing problems, especially for boys. In general, these interactions indicated that when paternal problem drinking was high, depression symptomatology and anxiety symptomatology were lower if maternal problem drinking was low. Findings from this study highlight the need to consider both paternal and maternal problem drinking when examining the effects that parental problem drinking may have on adolescent adjustment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Contamination of dried blood spots - an underestimated risk in newborn screening.

Science.gov (United States)

Winter, Theresa; Lange, Anja; Hannemann, Anke; Nauck, Matthias; Müller, Cornelia

2018-01-26

Newborn screening (NBS) is an established screening procedure in many countries worldwide, aiming at the early detection of inborn errors of metabolism. For decades, dried blood spots have been the standard specimen for NBS. The procedure of blood collection is well described and standardized and includes many critical pre-analytical steps. We examined the impact of contamination of some anticipated common substances on NBS results obtained from dry spot samples. This possible pre-analytical source of uncertainty has been poorly examined in the past. Capillary blood was obtained from 15 adult volunteers and applied to 10 screening filter papers per volunteer. Nine filter papers were contaminated without visible trace. The contaminants were baby diaper rash cream, baby wet wipes, disinfectant, liquid infant formula, liquid infant formula hypoallergenic (HA), ultrasonic gel, breast milk, feces, and urine. The differences between control and contaminated samples were evaluated for 45 NBS quantities. We estimated if the contaminations might lead to false-positive NBS results. Eight of nine investigated contaminants significantly altered NBS analyte concentrations and potentially caused false-positive screening outcomes. A contamination with feces was most influential, affecting 24 of 45 tested analytes followed by liquid infant formula (HA) and urine, affecting 19 and 13 of 45 analytes, respectively. A contamination of filter paper samples can have a substantial effect on the NBS results. Our results underline the importance of good pre-analytical training to make the staff aware of the threat and ensure reliable screening results.

prevalence, treatment and control of hypertension among type 2

African Journals Online (AJOL)

2014-08-01

Aug 1, 2014 ... lipids and creatinine, urine proteins) data from type 2 diabetic patients. Good BP control .... booked for DOPC and MOPC as the sample frame, systematic sampling ... storage were followed to minimise pre-analytical sources of ...

[Automation and organization of technological process of urinalysis].

Science.gov (United States)

Kolenkin, S M; Kishkun, A A; Kol'chenko, O L

2000-12-01

Results of introduction into practice of a working model of industrial technology of laboratory studies and KONE Specific Supra and Miditron M devices are shown as exemplified by clinical analysis of the urine. This technology helps standardize all stages and operations, improves the efficiency of quality control of laboratory studies, rationally organizes the work at all stages of the process, creates a system for permanent improvement of the efficiency of investigations at the preanalytical, analytical, and postanalytical stages of technological process of laboratory studies. As a result of introduction of this technology into laboratory practice, violations of quality criteria of clinical urinalysis decreased from 15 to 8% at the preanalytical stage and from 6 to 3% at the analytical stage. Automation of the analysis decreased the need in reagents 3-fold and improved the productivity at the analytical stage 4-fold.

Identification of Analytical Factors Affecting Complex Proteomics Profiles Acquired in a Factorial Design Study with Analysis of Variance : Simultaneous Component Analysis

NARCIS (Netherlands)

Mitra, V.; Govorukhina, N.; Zwanenburg, G.; Hoefsloot, H.; Westra, I.; Smilde, A.; Reijmers, T.; van der Zee, A.G.J.; Suits, F.; Bischoff, R.; Horvatovich, P.

2016-01-01

Complex shotgun proteomics peptide profiles obtained in quantitative differential protein expression studies, such as in biomarker discovery, may be affected by multiple experimental factors. These preanalytical factors may affect the measured protein abundances which in turn influence the outcome

Quality standards for sample collection in coagulation testing.

Science.gov (United States)

Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Lima-Oliveira, Gabriel; Guidi, Gian Cesare; Favaloro, Emmanuel J

2012-09-01

Preanalytical activities, especially those directly connected with blood sample collection and handling, are the most vulnerable steps throughout the testing process. The receipt of unsuitable samples is commonplace in laboratory practice and represents a serious problem, given the reliability of test results can be adversely compromised following analysis of these specimens. The basic criteria for an appropriate and safe venipuncture are nearly identical to those used for collecting blood for clinical chemistry and immunochemistry testing, and entail proper patient identification, use of the correct technique, as well as appropriate devices and needles. There are, however, some peculiar aspects, which are deemed to be particularly critical when collecting quality specimens for clot-based tests, and these require clearer recognition. These include prevention of prolonged venous stasis, collection of nonhemolyzed specimens, order of draw, and appropriate filling and mixing of the primary collection tubes. All of these important preanalytical issues are discussed in this article, and evidence-based suggestions as well as recommendations on how to obtain a high-quality sample for coagulation testing are also illustrated. We have also performed an investigation aimed to identify variation of test results due to underfilling of primary blood tubes, and have identified a clinically significant bias in test results when tubes are drawn at less than 89% of total fill for activated partial thromboplastin time, less than 78% for fibrinogen, and less than 67% for coagulation factor VIII, whereas prothrombin time and activated protein C resistance remain relatively reliable even in tubes drawn at 67% of the nominal volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Teen Depression and Suicide, A SILENT CRISIS.

Science.gov (United States)

Kroning, Maureen; Kroning, Kayla

2016-01-01

Adolescent depression is a serious problem affecting 10.7% of all teens and 29.9% of high school students; 17% of high school students have contemplated suicide. Yet, depression in teens is often unrecognized. This article relays the tragic death of a 17-year-old, along with symptoms of depression and suicide in adolescents; DSM-5 criteria for depression; treatments including protective factors, psychotherapy, and medications; and imparts interventions for addressing this huge but silent crisis.

EuroClonality/BIOMED-2 guidelines for interpretation and reporting of Ig/TCR clonality testing in suspected lymphoproliferations

NARCIS (Netherlands)

Langerak, A. W.; Groenen, P. J. T. A.; Brüggemann, M.; Beldjord, K.; Bellan, C.; Bonello, L.; Boone, E.; Carter, G. I.; Catherwood, M.; Davi, F.; Delfau-Larue, M.-H.; Diss, T.; Evans, P. A. S.; Gameiro, P.; Garcia Sanz, R.; Gonzalez, D.; Grand, D.; Håkansson, A.; Hummel, M.; Liu, H.; Lombardia, L.; Macintyre, E. A.; Milner, B. J.; Montes-Moreno, S.; Schuuring, E.; Spaargaren, M.; Hodges, E.; van Dongen, J. J. M.

2012-01-01

PCR-based immunoglobulin (Ig)/T-cell receptor (TCR) clonality testing in suspected lymphoproliferations has largely been standardized and has consequently become technically feasible in a routine diagnostic setting. Standardization of the pre-analytical and post-analytical phases is now essential to

Direct Problems and Inverse Problems in Biometric Systems

OpenAIRE

Mihailescu Marius Iulian

2013-01-01

The article purpose is to describe the two sides of biometrics technologies, direct problems and inverse problems. The advance that we face today in field of Information Technology makes Information Security an inseparable part. The authentication has a huge role when we deal about security. The problems that can appear in implementing and developing biometrics systems is raising many problems, and one of the goal of this article is to focus on direct and inverse problems which is a new and c...

Vulvodynia: An unrecognized diabetic neuropathic syndrome

Directory of Open Access Journals (Sweden)

Bharti Kalra

2013-01-01

Full Text Available Vulvar pain syndromes, including vulvodynia, are a common source of morbidity in women and cause much physical and psychological suffering. This brief communication postulates the hypothesis that unexplained vulvar pain may be hitherto undescribed manifestation of painful sensory diabetic neuropathy. It describes the clinical characteristics of vulvodynia and highlights the similarities between this condition and diabetic neuropathy. The hypothesis calls for women presenting with vulvar pain to be screened for diabetes, as well as women with diabetes to be questioned about vulvar symptomatology. The paper hopes to stimulate extensive research in this important, but so far neglected, field of women′s endocrine health.

The unrecognized burden of typhoid fever.

Science.gov (United States)

Obaro, Stephen K; Iroh Tam, Pui-Ying; Mintz, Eric Daniel

2017-03-01

Typhoid fever (TF), caused by Salmonella enterica serovar Typhi, is the most common cause of enteric fever, responsible for an estimated 129,000 deaths and more than 11 million cases annually. Although several reviews have provided global and regional TF disease burden estimates, major gaps in our understanding of TF epidemiology remain. Areas covered: We provide an overview of the gaps in current estimates of TF disease burden and offer suggestions for addressing them, so that affected communities can receive the full potential of disease prevention offered by vaccination and water, sanitation, and hygiene interventions. Expert commentary: Current disease burden estimates for TF do not capture cases from certain host populations, nor those with atypical presentations of TF, which may lead to substantial underestimation of TF cases and deaths. These knowledge gaps pose major obstacles to the informed use of current and new generation typhoid vaccines.

Hemiequilibrium problems

Directory of Open Access Journals (Sweden)

Muhammad Aslam Noor

2004-01-01

Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

Beyond Gamification:From Problem-solving to Problem-making

OpenAIRE

Ruffino, Paolo

2014-01-01

The problem I would like to highlight in this contribution is that gamification has been thought about too much as a tool for problem solving, and not enough as a tool for problem making. The idea of gamification as a tool for problem making could be more useful – although maybe paradoxically. As long as a technique is presented as a method for the solution of problems it can too easily become an authoritative proposal, which takes one solution and vision as necessarily better than the others...

Balance Problems

Science.gov (United States)

... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

The effects of residual platelets in plasma on plasminogen activator inhibitor-1 and plasminogen activator inhibitor-1-related assays

NARCIS (Netherlands)

M. Pieters (Marlien); S.A. Barnard (Sunelle A.); D.T. Loots (Du Toit); D.C. Rijken (Dingeman)

2017-01-01

textabstractDue to controversial evidence in the literature pertaining to the activity of plasminogen activator inhibitor-1 in platelets, we examined the effects of residual platelets present in plasma (a potential pre-analytical variable) on various plasminogen activator inhibitor-1 and plasminogen

Continuous quality control of the blood sampling procedure using a structured observation scheme

DEFF Research Database (Denmark)

Seemann, T. L.; Nybo, M.

2015-01-01

Background: An important preanalytical factor is the blood sampling procedure and its adherence to the guidelines, i.e. CLSI and ISO 15189, in order to ensure a consistent quality of the blood collection. Therefore, it is critically important to introduce quality control on this part of the process....... As suggested by the EFLM working group on the preanalytical phase we introduced continuous quality control of the blood sampling procedure using a structured observation scheme to monitor the quality of blood sampling performed on an everyday basis. Materials and methods: Based on our own routines the EFLM....... Conclusion: It is possible to establish a continuous quality control on blood sampling. It has been well accepted by the staff and we have already been able to identify critical areas in the sampling process. We find that continuous auditing increase focus on the quality of blood collection which ensures...

Effect of sample type, centrifugation and storage conditions on vitamin D concentration.

Science.gov (United States)

Colak, Ayfer; Toprak, Burak; Dogan, Nese; Ustuner, Fusun

2013-01-01

Studies about vitamin D [25(OH)D] stability in plasma are limited and preanalytical variables such as tube type may affect results. We aimed to evaluate effect of storage conditions, sample type and some preanalytical variables on vitamin D concentration. Blood samples from 15 healthy subjects were centrifuged at different temperatures and stored under different conditions. Serum and plasma 25(OH)D difference, effect of centrifugation temperature and common storage conditions were investigated. There was no difference between serum and plasma vitamin D concentration. Centrifugation temperature had no impact on vitamin D concentration. 25(OH)D is stable under common storage conditions: 4 hours at room temperature, 24 hours at 2-8 degrees C, 7 days at -20 degrees C, 3 months at -80 degrees C. Vitamin D does not require any special storage conditions and refrigeration. Both serum and plasma can be used for measurement.

Biospecimen quality program in the biobank of the Norwegian Institute of Public Health

Directory of Open Access Journals (Sweden)

Liv Paltiel

2012-04-01

Full Text Available Background: The biological material collected, processed and stored in biobanks are important research tools and it is important to minimize preanalytical variations to provide researchers with high quality biological material that will give reproducible results. Methods: To minimize the preanalytical variations caused by sample collection, processing and storage, we have established a biospecimen quality program. It consists of quality assurance aspects as well as quality control programs to measure adherence to protocols and sample integrity. The quality control program includes measurements and evaluation of the DNA quality and quantity before storage, i.e. concentration, purity, fragmentation and PCR success, and long term storage programs for plasma, urine and RNA. Conclusions: The Biobank at the Norwegian Institute of Public Health has established a biospecimen quality program that ensures high quality specimens and provides the documentation required to use the biomaterial in a best possible way.

A Six Sigma Trial For Reduction of Error Rates in Pathology Laboratory.

Science.gov (United States)

Tosuner, Zeynep; Gücin, Zühal; Kiran, Tuğçe; Büyükpinarbaşili, Nur; Turna, Seval; Taşkiran, Olcay; Arici, Dilek Sema

2016-01-01

A major target of quality assurance is the minimization of error rates in order to enhance patient safety. Six Sigma is a method targeting zero error (3.4 errors per million events) used in industry. The five main principles of Six Sigma are defining, measuring, analysis, improvement and control. Using this methodology, the causes of errors can be examined and process improvement strategies can be identified. The aim of our study was to evaluate the utility of Six Sigma methodology in error reduction in our pathology laboratory. The errors encountered between April 2014 and April 2015 were recorded by the pathology personnel. Error follow-up forms were examined by the quality control supervisor, administrative supervisor and the head of the department. Using Six Sigma methodology, the rate of errors was measured monthly and the distribution of errors at the preanalytic, analytic and postanalytical phases was analysed. Improvement strategies were reclaimed in the monthly intradepartmental meetings and the control of the units with high error rates was provided. Fifty-six (52.4%) of 107 recorded errors in total were at the pre-analytic phase. Forty-five errors (42%) were recorded as analytical and 6 errors (5.6%) as post-analytical. Two of the 45 errors were major irrevocable errors. The error rate was 6.8 per million in the first half of the year and 1.3 per million in the second half, decreasing by 79.77%. The Six Sigma trial in our pathology laboratory provided the reduction of the error rates mainly in the pre-analytic and analytic phases.

microRNA Biomarker Discovery and High-Throughput DNA Sequencing Are Possible Using Long-term Archived Serum Samples.

Science.gov (United States)

Rounge, Trine B; Lauritzen, Marianne; Langseth, Hilde; Enerly, Espen; Lyle, Robert; Gislefoss, Randi E

2015-09-01

The impacts of long-term storage and varying preanalytical factors on the quality and quantity of DNA and miRNA from archived serum have not been fully assessed. Preanalytical and analytical variations and degradation may introduce bias in representation of DNA and miRNA and may result in loss or corruption of quantitative data. We have evaluated DNA and miRNA quantity, quality, and variability in samples stored up to 40 years using one of the oldest prospective serum collections in the world, the Janus Serumbank, a biorepository dedicated to cancer research. miRNAs are present and stable in archived serum samples frozen at -25°C for at least 40 years. Long-time storage did not reduce miRNA yields; however, varying preanalytical conditions had a significant effect and should be taken into consideration during project design. Of note, 500 μL serum yielded sufficient miRNA for qPCR and small RNA sequencing and on average 650 unique miRNAs were detected in samples from presumably healthy donors. Of note, 500 μL serum yielded sufficient DNA for whole-genome sequencing and subsequent SNP calling, giving a uniform representation of the genomes. DNA and miRNA are stable during long-term storage, making large prospectively collected serum repositories an invaluable source for miRNA and DNA biomarker discovery. Large-scale biomarker studies with long follow-up time are possible utilizing biorepositories with archived serum and state-of-the-art technology. ©2015 American Association for Cancer Research.

Atypical meningococcal meningitis with rashless presentation：A case report

Institute of Scientific and Technical Information of China (English)

Sunita; Singh Manpreet; Kapoor Dheeraj

2012-01-01

Meningococcal disease is the major health problem in developing world. The clinical presentation is varied, ranging from transient fever and bacteraemia to fulminant disease with death ensuing within hours of the onset of clinical symptoms. The classical clinical manifestations of meningococcal disease have been well described, but atypical presentations if unrecognized, may lead to a delay in treatment and fatal outcome. We here report a case presented with atypical presentation of meningococcal meningitis without classical rash, which was diagnosed and managed successfully.

Reproducibility of mass spectrometry based protein profiles for diagnosis of ovarian cancer across clinical studies: A systematic review

DEFF Research Database (Denmark)

Callesen, AK; Mogensen, O; Jensen, AK

2012-01-01

of published discriminatory peaks to peaks found in an original MALDI MS protein profiling study was made to address the key question of reproducibility across studies. An overlap was found despite substantial heterogeneity between studies relating to study design, biological material, pre-analytical treatment...

Plasma tissue inhibitor of metalloproteinases-1 as a biological marker?

DEFF Research Database (Denmark)

Lomholt, Anne F.; Frederiksen, Camilla B.; Christensen, Ib J.

2007-01-01

Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) may be a valuable biological marker in Colorectal Cancer (CRC). However, prospective validation of TIMP-1 as a biological marker should include a series of pre-analytical considerations. TIMP-1 is stored in platelets, which may degranulate during...

"I have nine specialists. They need to swap notes!" Australian patients' perspectives of medication-related problems following discharge from hospital.

Science.gov (United States)

Eassey, Daniela; McLachlan, Andrew J; Brien, Jo-Anne; Krass, Ines; Smith, Lorraine

2017-10-01

Research has shown that patients are most susceptible to medication-related problems (MRPs) when transitioning from hospital to home. Currently, the literature in this area focuses on interventions, which are mainly orientated around the perspective of the health-care professional and do not take into account patient perspectives and experiences. To capture the experiences and perceptions of Australian patients regarding MRPs following discharge from hospital. A cross-sectional study was conducted using a questionnaire collecting quantitative and qualitative data. Thematic analysis was conducted of the qualitative data. Survey participants were recruited through The Digital Edge, an online market research company. Five hundred and six participants completed the survey. A total of 174 participants self-reported MRPs. Two concepts and seven subthemes emerged from the analysis. The first concept was types of MRPs and patient experiences. Three themes were identified: unwanted effects from medicines, confusion about medicines and unrecognized medicines. The second concept was patient engagement in medication management, of which four themes emerged: informing patients, patient engagement, communication amongst health-care professionals and conflicting advice. This study provides an important insight into patients' experiences and perceptions of MRPs following discharge from hospital. Future direction for practice and research should look into implementing patient-centred care at the time of hospital discharge to ensure the provision of clear and consistent information, and developing ways to support and empower patients to ensure a smooth transition post-discharge from hospital. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Toward Solving the Problem of Problem Solving: An Analysis Framework

Science.gov (United States)

Roesler, Rebecca A.

2016-01-01

Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

Effects of Worked Examples, Example-Problem Pairs, and Problem-Example Pairs Compared to Problem Solving

NARCIS (Netherlands)

Van Gog, Tamara; Kester, Liesbeth; Paas, Fred

2010-01-01

Van Gog, T., Kester, L., & Paas, F. (2010, August). Effects of worked examples, example-problem pairs, and problem-example pairs compared to problem solving. Paper presented at the Biannual EARLI SIG meeting of Instructional design and Learning and instruction with computers, Ulm, Germany.

Open-Start Mathematics Problems: An Approach to Assessing Problem Solving

Science.gov (United States)

Monaghan, John; Pool, Peter; Roper, Tom; Threlfall, John

2009-01-01

This article describes one type of mathematical problem, open-start problems, and discusses their potential for use in assessment. In open-start problems how one starts to address the problem can vary but they have a correct answer. We argue that the use of open-start problems in assessment could positively influence classroom mathematics…

Speech Problems

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Speech Problems KidsHealth / For Teens / Speech Problems What's in ... a person's ability to speak clearly. Some Common Speech and Language Disorders Stuttering is a problem that ...

Research

African Journals Online (AJOL)

raoul

2011-03-29

Mar 29, 2011 ... clinicians and laboratory personnel to improve quality of services. ... Audit has been defined as a quality improvement process that seeks to improve patient care and .... Principles for best practice in clinical audit. ... Luqman M. Clinician's responsibility in Pre-Analytical Quality Assurance of Histopathology.

Sociale problemer

DEFF Research Database (Denmark)

Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner

Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...... række fagfolk på tværs af det danske socialfaglige felt fokus på sociale problemer. Det diskuteres, hvad vi overhovedet forstår ved sociale problemer, hvordan de opstår, hvilke konsekvenser de har, og ikke mindst hvordan man som fagprofessionel håndterer sociale problemer i det daglige arbejde. Bogen er...... skrevet som lærebog til professionsuddannelser, hvor sociale problemer udgør en dimension, bl.a. socialrådgiver-, pædagog- og sygeplejerskeuddannelserne....

The Markov moment problem and extremal problems

CERN Document Server

Kreĭn, M G; Louvish, D

1977-01-01

In this book, an extensive circle of questions originating in the classical work of P. L. Chebyshev and A. A. Markov is considered from the more modern point of view. It is shown how results and methods of the generalized moment problem are interlaced with various questions of the geometry of convex bodies, algebra, and function theory. From this standpoint, the structure of convex and conical hulls of curves is studied in detail and isoperimetric inequalities for convex hulls are established; a theory of orthogonal and quasiorthogonal polynomials is constructed; problems on limiting values of integrals and on least deviating functions (in various metrics) are generalized and solved; problems in approximation theory and interpolation and extrapolation in various function classes (analytic, absolutely monotone, almost periodic, etc.) are solved, as well as certain problems in optimal control of linear objects.

Problem solving stages in the five square problem.

Science.gov (United States)

Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael

2015-01-01

According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight, and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviorally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. Our participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and some of them also had the possibility of reporting impasse while working on the task. We found that the majority of participants did not follow the classic four-stage model of insight, but had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model is not sufficient to describe variability on the individual level. We revised the classic model and we provide a new model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviorally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behavior to verify insight theory.

Problem solving stages in the five square problem

Directory of Open Access Journals (Sweden)

Anna eFedor

2015-08-01

Full Text Available According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviourally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. 101 participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and 67 of them also had the possibility of reporting impasse while working on the task. We have found that 49% (19 out of 39 of the solvers and 13% (8 out of 62 of the non-solvers followed the classic four-stage model of insight. The rest of the participants had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model must be extended to explain variability on the individual level. We provide a model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviourally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behaviour to verify insight theory.

Knapsack problems

CERN Document Server

Kellerer, Hans; Pisinger, David

2004-01-01

Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

Problem-based Learning and Problem Finding Among University Graduate Students

OpenAIRE

Ankit, A, Ravankar; Shotaro, Imai; Michiyo, Shimamura; Go, Chiba; Taichi, Takasuka

2017-01-01

In recent years, problem-based learning (PBL) techniques have been gaining momentum in schools and university curricula around the world. The main advantage of the PBL method is that it promotes creative problem solving, improves cognition and enhances overall thought processes in learners. For most PBL-style programmes, problem solving is at the core, although the notion of problem discovery or problem finding is not seriously considered. In most cases, students are always presen...

A further problem of the hard problem of consciousness | Gbenga ...

African Journals Online (AJOL)

Justifying this assertion is identified as the further problem of the hard problem of consciousness. This shows that assertions about phenomenal properties of mental experiences are wholly epistemological. Hence, the problem of explaining phenomenal properties of a mental state is not a metaphysical problem, and what is ...

Elevated zinc concentrations in a 5 months old infant

DEFF Research Database (Denmark)

Petersen, Eva Rabing Brix; Mortensen, Sven; Nybo, Mads

2018-01-01

Pre-analytical errors account for the majority of laboratory-associated errors. In a 5 months old infant hospitalised with lung dysfunction due to prematurity, a routine measurement of zinc revealed an unexpected elevated concentration of 20.2 µmol/L (reference interval 10.0 - 19.0 µmol/L) compar...

Cirrhosis is Under-recognized in Patients Subsequently Diagnosed with Hepatocellular Cancer

Science.gov (United States)

Walker, Megan; El-Serag, Hashem B.; Sada, Yvonne; Mittal, Sahil; Ying, Jun; Duan, Zhigang; Richardson, Peter; Davila, Jessica A.; Kanwal, Fasiha

2015-01-01

Background Most clinical practice guidelines recommend screening for HCC in patients with cirrhosis. However, patients with compensated cirrhosis are often asymptomatic and may remain unrecognized for years. Aims To determine the extent to which cirrhosis is unrecognized in a US Veteran population with HCC and to evaluate the association between lack of cirrhosis recognition and stage of HCC at diagnosis. Methods We reviewed the electronic medical records of a random sample of HCC cases diagnosed in the national Veterans Affairs system between 2005 and 2011. We conducted multivariable analyses adjusting for patients’ demographics, comorbidity, etiology of underlying disease, and healthcare utilization including HCC surveillance. Results Of 1201 patients with HCC and cirrhosis, 24.6% had unrecognized cirrhosis prior to HCC diagnosis. Older patients (>65yr, odds ratio [OR] 2.32), African Americans (OR 1.93), patients with alcoholic or NAFLD liver disease (OR 1.69 and 4.77 respectively), HIV (OR 3.02), and fewer comorbidities (Deyo 0 vs. 3, OR 2.42) had significantly higher odds of having unrecognized cirrhosis than comparison groups. Furthermore, patients with unrecognized cirrhosis were 6.5 times more likely to have advanced stage HCC at diagnosis. The effect of cirrhosis recognition on HCC stage remained significant after adjusting for pre-specified covariates (OR 3.37). Conclusions In one fourth of patients, cirrhosis was unrecognized prior to HCC diagnosis, and this group was significantly more likely to have advanced stage HCC. These findings emphasize the importance of timely evaluation for cirrhosis in at-risk populations as a critical step to improving outcomes for HCC patients. PMID:26784271

Preanalytical Blood Sampling Errors in Clinical Settings

International Nuclear Information System (INIS)

Zehra, N.; Malik, A. H.; Arshad, Q.; Sarwar, S.; Aslam, S.

2016-01-01

Background: Blood sampling is one of the common procedures done in every ward for disease diagnosis and prognosis. Daily hundreds of samples are collected from different wards but lack of appropriate knowledge of blood sampling by paramedical staff and accidental errors make the samples inappropriate for testing. Thus the need to avoid these errors for better results still remains. We carried out this research with an aim to determine the common errors during blood sampling; find factors responsible and propose ways to reduce these errors. Methods: A cross sectional descriptive study was carried out at the Military and Combined Military Hospital Rawalpindi during February and March 2014. A Venous Blood Sampling questionnaire (VBSQ) was filled by the staff on voluntary basis in front of the researchers. The staff was briefed on the purpose of the survey before filling the questionnaire. Sample size was 228. Results were analysed using SPSS-21. Results: When asked in the questionnaire, around 61.6 percent of the paramedical staff stated that they cleaned the vein by moving the alcohol swab from inward to outwards while 20.8 percent of the staff reported that they felt the vein after disinfection. On contrary to WHO guidelines, 89.6 percent identified that they had a habit of placing blood in the test tube by holding it in the other hand, which should actually be done after inserting it into the stand. Although 86 percent thought that they had ample knowledge regarding the blood sampling process but they did not practice it properly. Conclusion: Pre analytical blood sampling errors are common in our setup. Eighty six percent participants though thought that they had adequate knowledge regarding blood sampling, but most of them were not adhering to standard protocols. There is a need of continued education and refresher courses. (author)

Preanalytical quality improvement : in quality we trust

OpenAIRE

Lippi, Giuseppe; Becan-McBride, Kathleen; Behulova, Darina; Bowen, Raffick A.; Church, Stephen; Delanghe, Joris; Grankvist, Kjell; Kitchen, Steve; Nybo, Mads; Nauck, Matthias; Nikolac, Nora; Palicka, Vladimir; Plebani, Mario; Sandberg, Sverre; Simundic, Ana-Maria

2013-01-01

Total quality in laboratory medicine should be defined as the guarantee that each activity throughout the total testing process is correctly performed, providing valuable medical decision-making and effective patient care. In the past decades, a 10-fold reduction in the analytical error rate has been achieved thanks to improvements in both reliability and standardization of analytical techniques, reagents, and instrumentation. Notable advances in information technology, quality control and qu...

Using Lean-Six Sigma to reduce hemolysis in the emergency care center in a collaborative quality improvement project with the hospital laboratory.

Science.gov (United States)

Damato, Charlotte; Rickard, Dana

2015-03-01

As part of a strategic quality improvement plan, laboratory management at Sarasota Memorial Health Care System (SMHCS) focused its efforts on improving preanalytical work flow and blood collection processes-both negatively affected by hemolyzed specimens. When hemolysis is detected in a blood specimen, blood may need to be re-collected, resulting in bottlenecks and rework all along the value stream. From July through December 2009, hemolysis averaged 9.8% in the Emergency Care Center (ECC) and 3.4% housewide. The goal was set to reduce hemolysis to 2%. The project team identified hemolysis as one of seven factors contributing to non-value-added activities and bottlenecks in blood collection and preanalytical processes. Observations and interviews helped to identify error-prone practices and process variation. To verify the root causes of hemolysis, the findings were compared against best practices. The team developed a housewide protocol, standardized collection processes, created competency-based training, and enhanced ECC hiring practices. During December 2010-March 2011, following initial housewide interventions and ECC self-sustaining solutions, ECC hemolysis decreased by 91%-from 9.8% (423 hemolyzed/4,295 collected) to 0.88% (58 hemolyzed/6,560 collected). Housewide hemolysis decreased by 59%-from 3.4% (2,046 hemolyzed/60,307 collected) to 1.39% (619 hemolyzed/44,528 collected). Since the project, hemolysis has continued to trend downward; the mean percentage has consistently been Lean-Six Sigma tools helped to pinpoint hemolysis as a key inefficiency in blood collection and preanalytical work flow. Although focused on the ECC, the project team standardized blood collection practices and instituted quality devices to achieve hemolysis reductions housewide.

Standardization and optimization of fluorescence in situ hybridization (FISH for HER-2 assessment in breast cancer: A single center experience

Directory of Open Access Journals (Sweden)

Magdalena Bogdanovska-Todorovska

2018-05-01

Full Text Available Accurate assessment of human epidermal growth factor receptor 2 (HER-2 is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC and fluorescence in situ hybridization (FISH. Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples and DAKO Histology FISH Accessory Kit (30 samples. The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70; the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p < 0.0001. The greatest discordance (82% between IHC and FISH was observed in IHC 2+ group. A standardized FISH protocol for HER-2 assessment, with high hybridization efficiency, is necessary due to variability in tissue processing and individual tissue characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.

Assessment of macrophage migration inhibitory factor in humans: protocol for accurate and reproducible levels.

Science.gov (United States)

Sobierajski, Julia; Hendgen-Cotta, Ulrike B; Luedike, Peter; Stock, Pia; Rammos, Christos; Meyer, Christian; Kraemer, Sandra; Stoppe, Christian; Bernhagen, Jürgen; Kelm, Malte; Rassaf, Tienush

2013-10-01

The analytical validation of a possible biomarker is the first step in the long translational process from basic science to clinical routine. Although the chemokine-like cytokine macrophage migration inhibitory factor (MIF) has been investigated intensively in experimental approaches to various disease conditions, its transition into clinical research is just at the very beginning. Because of its presence in preformed storage pools, MIF is the first cytokine to be released under various stimulation conditions. In the first proof-of-concept studies, MIF levels correlated with the severity and outcome of various disease states. In a recent small study with acute coronary syndrome patients, elevation of MIF was described as a new factor for risk assessment. When these studies are compared, not only MIF levels in diseased patients differ, but also MIF levels in healthy control groups are inconsistent. Blood MIF concentrations in control groups vary between 0.56 and 95.6 ng/ml, corresponding to a 170-fold difference. MIF concentrations in blood were analyzed by ELISA. Other than the influence of this approach due to method-based variations, the impact of preanalytical processing on MIF concentrations is unclear and has not been systematically studied yet. Before large randomized studies are performed to determine the impact of circulating MIF on prognosis and outcome and before MIF is characterized as a diagnostic marker, an accurate protocol for the determination of reproducible MIF levels needs to be validated. In this study, the measurement of MIF in the blood of healthy volunteers was investigated focusing on the potential influence of critical preanalytical factors such as anticoagulants, storage conditions, freeze/thaw stability, hemolysis, and dilution. We show how to avoid pitfalls in the measurement of MIF and that MIF concentrations are highly susceptible to preanalytical factors. MIF serum concentrations are higher than plasma concentrations and show broader

Differences in the Processes of Solving Physics Problems between Good Physics Problem Solvers and Poor Physics Problem Solvers.

Science.gov (United States)

Finegold, M.; Mass, R.

1985-01-01

Good problem solvers and poor problem solvers in advanced physics (N=8) were significantly different in their ability in translating, planning, and physical reasoning, as well as in problem solving time; no differences in reliance on algebraic solutions and checking problems were noted. Implications for physics teaching are discussed. (DH)

Core components of a comprehensive quality assurance program in anatomic pathology.

Science.gov (United States)

Nakhleh, Raouf E

2009-11-01

In this article the core components of a comprehensive quality assurance and improvement plan are outlined. Quality anatomic pathology work comes with focus on accurate, timely, and complete reports. A commitment to continuous quality improvement and a systems approach with a persistent effort helps to achieve this end. Departments should have a quality assurance and improvement plan that includes a risk assessment of real and potential problems facing the laboratory. The plan should also list the individuals responsible for carrying out the program with adequate resources, a defined timetable, and annual assessment for progress and future directions. Quality assurance monitors should address regulatory requirements and be organized by laboratory division (surgical pathology, cytology, etc) as well as 5 segments (preanalytic, analytic, postanalytic phases of the test cycle, turn-around-time, and customer satisfaction). Quality assurance data can also be used to evaluate individual pathologists using multiple parameters with peer group comparison.

Inferencia léxica como método de ampliación de vocabulario en el aprendizaje del chino moderno

Directory of Open Access Journals (Sweden)

Zhang Zheng Quan

2011-01-01

Full Text Available Compound words, the vast majority of the Modern Chinese lexicon, are formed by characters and can be analyzed morphologically and semantically, which facilitates lexical inference as a vocabulary learning method. Nevertheless, in the teaching of Chinese as a foreign language, this method goes unrecognized, due to the lack of explanation of either the meanings of the characters or the rules of compound word formation. This work reveals this problem and studies the method from morphological, lexematic and didactic perspectives, demonstrating its viability and efficacy and putting forward suggestions for its teaching.

Current management of nocturnal enuresis.

Science.gov (United States)

Robson, Wm Lane M

2008-07-01

Nocturnal enuresis is an especially common problem with the potential to have an appreciable negative impact on the emotional health of a child. Our understanding of the pathogenesis continues to improve. A disorder of sleep arousal, a low nocturnal bladder capacity, and nocturnal polyuria are the three factors that interrelate to cause nocturnal enuresis. Constipation is a very common and often unrecognized factor that appreciably affects bladder function. Successful treatment involves interventions that simultaneously improve these factors. Self-esteem improves with any form of therapy and dryness is possible for the majority of children.

VITAMIN D DEFICIENCY AND ITS HEALTH CONSEQUENCES – A REVIEW

Directory of Open Access Journals (Sweden)

V Jyoti

2012-09-01

Full Text Available The world is currently facing an unrecognized and untreated pandemic of Vitamin D Deficiency (VDD1. VDD is a significant public health problem in both developed and developing countries, including India2. It is highly prevalent across all age groups. Vitamin D (VD is a prehormone that humans obtain from foods and dietary supplements and by endogenous skin synthesis from7-dehydrocholesterol with sunlight exposure3. The present article reviews the etiology of VDD, physiological functions, sources, health consequences and prevalence of VDD in different regions of India.

VITAMIN D DEFICIENCY AND ITS HEALTH CONSEQUENCES – A REVIEW

Directory of Open Access Journals (Sweden)

V Jyoti

2012-10-01

Full Text Available The world is currently facing an unrecognized and untreated pandemic of Vitamin D Deficiency (VDD1. VDD is a significant public health problem in both developed and developing countries, including India2. It is highly prevalent across all age groups. Vitamin D (VD is a prehormone that humans obtain from foods and dietary supplements and by endogenous skin synthesis from7-dehydrocholesterol with sunlight exposure3. The present article reviews the etiology of VDD, physiological functions, sources, health consequences and prevalence of VDD in different regions of India.

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Directory of Open Access Journals (Sweden)

Shih-Yin Lin

2013-10-01

Full Text Available In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem. The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2013-12-01

In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem). The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few possible strategies

"What constitutes a 'problem'?" Producing 'alcohol problems' through online counselling encounters.

Science.gov (United States)

Savic, Michael; Ferguson, Nyssa; Manning, Victoria; Bathish, Ramez; Lubman, Dan I

2017-08-01

Typically, health policy, practice and research views alcohol and other drug (AOD) 'problems' as objective things waiting to be detected, diagnosed and treated. However, this approach to policy development and treatment downplays the role of clinical practices, tools, discourses, and systems in shaping how AOD use is constituted as a 'problem'. For instance, people might present to AOD treatment with multiple psycho-social concerns, but usually only a singular AOD-associated 'problem' is considered serviceable. As the assumed nature of 'the serviceable problem' influences what treatment responses people receive, and how they may come to be enacted as 'addicted' or 'normal' subjects, it is important to subject clinical practices of problem formulation to critical analysis. Given that the reach of AOD treatment has expanded via the online medium, in this article we examine how 'problems' are produced in online alcohol counselling encounters involving people aged 55 and over. Drawing on poststructural approaches to problematisation, we not only trace how and what 'problems' are produced, but also what effects these give rise to. We discuss three approaches to problem formulation: (1) Addiction discourses at work; (2) Moving between concerns and alcohol 'problems'; (3) Making 'problems' complex and multiple. On the basis of this analysis, we argue that online AOD counselling does not just respond to pre-existing 'AOD problems'. Rather, through the social and clinical practices of formulation at work in clinical encounters, online counselling also produces them. Thus, given a different set of circumstances, practices and relations, 'problems' might be defined or emerge differently-perhaps not as 'problems' at all or perhaps as different kinds of concerns. We conclude by highlighting the need for a critical reflexivity in AOD treatment and policy in order to open up possibilities for different ways of engaging with, and responding to, people's needs in their complexity

How do open-ended problems promote mathematical creativity? A reflection of bare mathematics problem and contextual problem

Science.gov (United States)

Wijaya, A.

2018-03-01

Creativity is often seen as one of the fundamental aspects of character education. As one of the 21st century skills, creativity has also been considered as an important goal of education across the world. This paper reports a study on promoting mathematical creativity through the use of open-ended mathematics problems. A total of 53 undergraduate students participated in the study. These students worked on open-ended problems in two types, i.e. bare mathematics problem and contextual problem. The contextual problem was presented in the form of paper-based and Geogebra-based. The students’ works were analysed qualitatively in order to describe how students’ mathematical creativity developed. It was found that the open-ended problems successfully promote students’ creativity as indicated by various solutions or strategies that were used by students to solve the problems. The analysis of students’ works show that students’ creativity developed through three kinds of exploration, i. e. (1) exploration of contexts, (2) exploration of software features, and (3) exploration of mathematics concepts. The use of metacognitive questioning was found to be helpful to develop the first two explorations into mathematical exploration.

Diagnosing plant problems

Science.gov (United States)

Cheryl A. Smith

2008-01-01

Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

[Pierre Mornard (1883-1929), unrecognized plastic surgeon].

Science.gov (United States)

Glicenstein, J

2017-02-01

Many operations of aesthetic surgery were described between 1920 and 1930. Several French surgeons are recognized as pioneers of the speciality. Pierre Mornard (1883-1929) published numerous articles of plastic and aesthetic surgery between 1925 and 1929 the date of his death. The articles were illustrated with drawings of surgery he had practiced. He described in 1929 the first abdominoplasty with umbilical transposition. Pierre Mornard can be considered a pioneer of aesthetic surgery. Copyright © 2016. Published by Elsevier Masson SAS.

General problems

International Nuclear Information System (INIS)

2005-01-01

This article presents the general problems as natural disasters, consequences of global climate change, public health, the danger of criminal actions, the availability to information about problems of environment

Teaching Problem Solving without Modeling through "Thinking Aloud Pair Problem Solving."

Science.gov (United States)

Pestel, Beverly C.

1993-01-01

Reviews research relevant to the problem of unsatisfactory student problem-solving abilities and suggests a teaching strategy that addresses the issue. Author explains how she uses teaching aloud problem solving (TAPS) in college chemistry and presents evaluation data. Among the findings are that the TAPS class got fewer problems completely right,…

Kolkata Restaurant Problem as a Generalised El Farol Bar Problem

Science.gov (United States)

Chakrabarti, Bikas K.

Generalisation of the El Farol bar problem to that of many bars here leads to the Kolkata restaurant problem, where the decision to go to any restaurant or not is much simpler (depending on the previous experience of course, as in the El Farol bar problem). This generalised problem can be exactly analysed in some limiting cases discussed here. The fluctuation in the restaurant service can be shown to have precisely an inverse cubic behavior, as widely seen in the stock market fluctuations.

Matrix interdiction problem

Energy Technology Data Exchange (ETDEWEB)

Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

2010-01-01

In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

Islamic Education Research Problem

Directory of Open Access Journals (Sweden)

Abdul Muthalib

2012-04-01

Full Text Available This paper will discuss Islamic educational studies that is reviewing how to find, limit and define problems and problem-solving concepts. The central question of this paper is to describe how to solve the problem in Islamic educational research. A researcher or educator who has the knowledge, expertise, or special interest on education for example is usually having a sensitivity to issues relating to educational research. In the research dimension of religious education, there are three types of problems, namely: Problems foundation, structural problems and operational issues. In doing research in Islamic education someone should understand research problem, limiting and formulating the problem, how to solve the problem, other problem relating to the point of research, and research approach.

The Chicken Problem.

Science.gov (United States)

Reeves, Charles A.

2000-01-01

Uses the chicken problem for sixth grade students to scratch the surface of systems of equations using intuitive approaches. Provides students responses to the problem and suggests similar problems for extensions. (ASK)

Ankle Problems

Science.gov (United States)

... Read MoreDepression in Children and TeensRead MoreBMI Calculator Ankle ProblemsFollow this chart for more information about problems that can cause ankle pain. Our trusted Symptom Checker is written and ...

Preventing Diabetes Problems

Science.gov (United States)

... Problems Diabetes, Sexual, & Bladder Problems Clinical Trials Preventing Diabetes Problems View or Print All Sections Heart Disease & ... to help control symptoms and restore intimacy. Depression & Diabetes Depression is common among people with a chronic, ...

Prostate Problems

Science.gov (United States)

... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

Radioactive wastes: a world problem. Les dechets nucleaires: un probleme mondial

Energy Technology Data Exchange (ETDEWEB)

Schapira, J P [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (FR)

1991-02-01

In all countries endowed with nuclear program, radioactive wastes disposal asks scientific and public acceptance problems. This paper describes several aspects: technical problem; ethic problem and responsibility towards future generations at very long-term; political problem. Different politics followed by concerned countries and recent controversy in France is also entered upon radioactive wastes underground site selection, in deep geological formations.

Popular Problems

DEFF Research Database (Denmark)

Skovhus, Randi Boelskifte; Thomsen, Rie

2017-01-01

This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

Case Problems for Problem-Based Pedagogical Approaches: A Comparative Analysis

Science.gov (United States)

Dabbagh, Nada; Dass, Susan

2013-01-01

A comparative analysis of 51 case problems used in five problem-based pedagogical models was conducted to examine whether there are differences in their characteristics and the implications of such differences on the selection and generation of ill-structured case problems. The five pedagogical models were: situated learning, goal-based scenario,…

The effect of problem-based and lecture-based instructional strategies on learner problem solving performance, problem solving processes, and attitudes

Science.gov (United States)

Visser, Yusra Laila

This study compared the effect of lecture-based instruction to that of problem-based instruction on learner performance (on near-transfer and far-transfer problems), problem solving processes (reasoning strategy usage and reasoning efficiency), and attitudes (overall motivation and learner confidence) in a Genetics course. The study also analyzed the effect of self-regulatory skills and prior-academic achievement on performance for both instructional strategies. Sixty 11th grade students at a public math and science academy were assigned to either a lecture-based instructional strategy or a problem-based instructional strategy. Both treatment groups received 18 weeks of Genetics instruction through the assigned instructional strategy. In terms of problem solving performance, results revealed that the lecture-based group performed significantly better on near-transfer post-test problems. The problem-based group performed significantly better on far-transfer post-test problems. In addition, results indicated the learners in the lecture-based instructional treatment were significantly more likely to employ data-driven reasoning in the solving of problems, whereas learners in the problem-based instructional treatment were significantly more likely to employ hypothesis-driven reasoning in problem solving. No significant differences in reasoning efficiency were uncovered between treatment groups. Preliminary analysis of the motivation data suggested that there were no significant differences in motivation between treatment groups. However, a post-research exploratory analysis suggests that overall motivation was significantly higher in the lecture-based instructional treatment than in the problem-based instructional treatment. Learner confidence was significantly higher in the lecture-based group than in the problem-based group. A significant positive correlation was detected between self-regulatory skills scores and problem solving performance scores in the problem

Problem Posing

OpenAIRE

Šilhavá, Marie

2009-01-01

This diploma thesis concentrates on problem posing from the students' point of view. Problem posing can be either seen as a teaching method which can be used in the class, or it can be used as a tool for researchers or teachers to assess the level of students' understanding of the topic. In my research, I compare three classes, one mathematics specialist class and two generalist classes, in their ability of problem posing. As an assessment tool it seemed that mathemathics specialists were abl...

Learning Problems

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Learning Problems KidsHealth / For Kids / Learning Problems What's in ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...

Hearing Problems

Science.gov (United States)

... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

Biospecimen Reporting for Improved Study Quality (BRISQ)

Energy Technology Data Exchange (ETDEWEB)

National Cancer Institute; Jewell, Ph.D., Scott D.; Seijo, M.S., Edward; Kelly, Ph.D., Andrea; Somiari, Ph.D., Stella; B.Chir., M.B.; McShane, Ph.D., Lisa M.; Clark, M.D., Douglas; Greenspan, M.D., Renata; Hayes, M.D., Daniel F.; Hainaut, Ph.D., M.S., Pierre; Kim, Paula; Mansfield, Ph.D., Elizabeth; Potapova, Ph.D., Olga; Riegman, Ph.D., Peter; Rubinstein, Ph.D., Yaffa; Weier, Ph.D., Heinz-Ulrich; Zhu, Ph.D., Claire; Moore, Ph.D., Helen M.; Vaught, Ph.D., Jim; Watson, Peter

2010-09-02

Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses human tissues, it is crucial that information on the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications on biospecimen-related research and to help reassure patient contributors and the advocacy community that their contributions are valued and respected.

Biospecimen Reporting for Improved Study Quality

Energy Technology Data Exchange (ETDEWEB)

Moore, Ph.D., Helen M.; Kelly, Ph.D., Andrea B.; Jewell, Ph.D., Scott D.; McShane, Ph.D., Lisa M.; Clark, M.D., Douglas P.; Greenspan, M.D., Renata; Hayes, M.D., Daniel F.; Hainaut, Ph.D., Pierre; Kim, Paula; Mansfield, Ph.D., Elizabeth A.; Potapova, Ph.D., Olga; Riegman, Ph.D., Peter; Rubinstein, Ph.D., Yaffa; Seijo, M.S., Edward; Somiari, Ph.D., Stella; Chir., B; Weier, Ph.D., Heinz-Ulrich; Zhu, Ph.D., Claire; Vaught, Ph.D., Jim; Watson,M.B., Peter

2010-12-27

Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses human tissues, it is crucial that information on the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications on biospecimen-related research and to help reassure patient contributors and the advocacy community that their contributions are valued and respected.

Biospecimen Reporting for Improved Study Quality (BRISQ)

Energy Technology Data Exchange (ETDEWEB)

Moore, Ph.D., Helen M.; Kelly Ph.D., Andrea; Jewell Ph.D., Scott D.; McShane Ph.D., Lisa M.; Clark M.D., Douglas P.; Greenspan M.D., Renata; Hayes M.D., Daniel F.; Hainaut Ph.D.,, Pierre; Kim, Paula; Mansfield Ph.D., Elizabeth; Potapova Ph.D., Olga; Riegman Ph.D., Peter; Rubinstein Ph.D., Yaffa; Seijo M.S., Edward; Somiari Ph.D., Stella; Watson M.B., Peter; Weier Ph.D., Heinz-Ulrich; Zhu Ph.D., Claire; Vaught Ph.D., Jim

2011-04-26

Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research utilizing human tissues it is critical that information regarding the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications around biospecimen-related research and help reassure patient contributors and the advocacy community that the contributions are valued and respected.

Assessment of vertical transfer in problem solving: Mapping the problem design space

Science.gov (United States)

Von Korff, Joshua; Hu, Dehui; Rebello, N. Sanjay

2012-02-01

In schema-based theories of cognition, vertical transfer occurs when a learner constructs a new schema to solve a transfer task or chooses between several possible schemas. Vertical transfer is interesting to study, but difficult to measure. Did the student solve the problem using the desired schema or by an alternative method? Perhaps the problem cued the student to use certain resources without knowing why? In this paper, we consider some of the threats to validity in problem design. We provide a theoretical framework to explain the challenges faced in designing vertical transfer problems, and we contrast these challenges with horizontal transfer problem design. We have developed this framework from a set of problems that we tested on introductory mechanics students, and we illustrate the framework using one of the problems.

Problem Solving Reasoning and Problem Based Instruction in Geometry Learning

Science.gov (United States)

Sulistyowati, F.; Budiyono, B.; Slamet, I.

2017-09-01

This research aims to analyze the comparison Problem Solving Reasoning (PSR) and Problem Based Instruction (PBI) on problem solving and mathematical communication abilities viewed from Self-Regulated Learning (SRL). Learning was given to grade 8th junior high school students. This research uses quasi experimental method, and then with descriptive analysis. Data were analyzed using two-ways multivariate analysis of variance (MANOVA) and one-way analysis of variance (ANOVA) with different cells. The result of data analysis were learning model gives different effect, level of SRL gives the same effect, and there is no interaction between the learning model with the SRL on the problem solving and mathematical communication abilities. The t-test statistic was used to find out more effective learning model. Based on the test, regardless of the level of SRL, PSR is more effective than PBI for problemsolving ability. The result of descriptive analysis was PSR had the advantage in creating learning that optimizing the ability of learners in reasoning to solve a mathematical problem. Consequently, the PSR is the right learning model to be applied in the classroom to improve problem solving ability of learners.

Early breastfeeding problems

DEFF Research Database (Denmark)

Feenstra, Maria Monberg; Kirkeby, Mette Jørgine; Thygesen, Marianne

2018-01-01

Objectives Breastfeeding problems are common and associated with early cessation. Stilllength of postpartum hospital stay has been reduced. This leaves new mothers to establish breastfeeding at home with less support from health care professionals. The objective was to explore mothers’ perspectives...... on when breastfeeding problems were the most challenging and prominent early postnatal. The aim was also toidentify possible factors associated with the breastfeeding problems. Methods In a cross-sectional study, a mixed method approach was used to analyse postal survey data from 1437 mothers with full...... term singleton infants. Content analysis was used to analyse mothers’ open text descriptions of their most challenging breastfeeding problem. Multiple logistic regression was used to calculate odds ratios for early breastfeeding problems according to sociodemographic- and psychosocial factors. Results...

Investigation of Problem-Solving and Problem-Posing Abilities of Seventh-Grade Students

Science.gov (United States)

Arikan, Elif Esra; Ünal, Hasan

2015-01-01

This study aims to examine the effect of multiple problem-solving skills on the problem-posing abilities of gifted and non-gifted students and to assess whether the possession of such skills can predict giftedness or affect problem-posing abilities. Participants' metaphorical images of problem posing were also explored. Participants were 20 gifted…

Mathematical Tasks without Words and Word Problems: Perceptions of Reluctant Problem Solvers

Science.gov (United States)

Holbert, Sydney Margaret

2013-01-01

This qualitative research study used a multiple, holistic case study approach (Yin, 2009) to explore the perceptions of reluctant problem solvers related to mathematical tasks without words and word problems. Participants were given a choice of working a mathematical task without words or a word problem during four problem-solving sessions. Data…

Quality control in haemostasis.

Science.gov (United States)

Capel, P; Chatelain, B; Leclerq, R; Lust, A; Masure, R; Arnout, J

1992-01-01

Laboratory investigation of the haemostatic system deserves particular procedures in the quality control of analytical variables as well as preanalytical variables. This paper reviews the precautions that have to be taken in the blood prelevement, the transport of the tubes and the performance of the laboratory tests aimed to investigate the haemostatic system in order to obtain reliable results.

Laboratory Request Forms- How Well do Doctors Fill Them? A Look ...

African Journals Online (AJOL)

TNHJOURNALPH

Effect of pre-analytic errors on quality of laboratory Medicine at a neuropsychiatric institute inN orth India. IndJ ClinBiochem. 2011; 26(1): 46-49. 8. Oladeinde BH, Omeregie R, Osakue EO,. Onifade AO. Evaluation of laboratory request forms for incomplete data at a rural tertiary hospital in Nigeria. NZJ. Med Lab. 2012; 66; 2: ...

Mathematical conversations multicolor problems, problems in the theory of numbers, and random walks

CERN Document Server

Dynkin, E B

2006-01-01

Comprises Multicolor Problems, dealing with map-coloring problems; Problems in the Theory of Numbers, an elementary introduction to algebraic number theory; Random Walks, addressing basic problems in probability theory. 1963 edition.

Cosmological constant problem

International Nuclear Information System (INIS)

Weinberg, S.

1989-01-01

Cosmological constant problem is discussed. History of the problem is briefly considered. Five different approaches to solution of the problem are described: supersymmetry, supergravity, superstring; anthropic approach; mechamism of lagrangian alignment; modification of gravitation theory and quantum cosmology. It is noted that approach, based on quantum cosmology is the most promising one

Differential equations problem solver

CERN Document Server

Arterburn, David R

2012-01-01

REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and

Problem-formulation and problem-solving in self-organized communities

DEFF Research Database (Denmark)

Foss, Nicolai J.; Frederiksen, Lars; Rullani, Francesco

2016-01-01

Building on the problem-solving perspective, we study behaviors related to projects and the communication-based antecedents of such behaviors in the free open-source software (FOSS) community. We examine two kinds of problem/project-behaviors: Individuals can set up projects around the formulation...

Inverse feasibility problems of the inverse maximum flow problems

Indian Academy of Sciences (India)

199–209. c Indian Academy of Sciences. Inverse feasibility problems of the inverse maximum flow problems. ADRIAN DEACONU. ∗ and ELEONOR CIUREA. Department of Mathematics and Computer Science, Faculty of Mathematics and Informatics, Transilvania University of Brasov, Brasov, Iuliu Maniu st. 50,. Romania.

[Population problem, comprehension problem].

Science.gov (United States)

Tallon, F

1993-08-01

Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

The internal percolation problem

International Nuclear Information System (INIS)

Bezsudnov, I.V.; Snarskii, A.A.

2010-01-01

The internal percolation problem (IP) as a new type of the percolation problem is introduced and investigated. In spite of the usual (or external) percolation problem (EP) when the percolation current flows from the top to the bottom of the system, in IP case the voltage is applied through bars which are present in the hole located within the system. The EP problem has two major parameters: M-size of the system and a 0 -size of inclusions, bond size, etc. The IP problem holds one parameter more: size of the hole L. Numerical simulation shows that the critical indexes of conductance for the IP problem are very close to those in the EP problem. On the contrary, the indexes of the relative spectral noise density of 1/f noise and higher moments differ from those in the EP problem. The basics of these facts is discussed.

Fostering information problem solving skills through completion problems and prompts

NARCIS (Netherlands)

Frerejean, Jimmy; Brand-Gruwel, Saskia; Kirschner, Paul A.

2012-01-01

Frerejean, J., Brand-Gruwel, S., & Kirschner, P. A. (2012, November). Fostering information problem solving skills through completion problems and prompts. Poster presented at the ICO Fall School 2012, Girona, Spain.

The moment problem

CERN Document Server

Schmüdgen, Konrad

2017-01-01

This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...

Structural Identification Problem

Directory of Open Access Journals (Sweden)

Suvorov Aleksei

2016-01-01

Full Text Available The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

Integrating Multimedia and Physics Problems

Science.gov (United States)

Titus, Aaron P.

1997-11-01

Although expert problem solvers typically use pictorial representations when solving problems, novices tend to proceed from the given problem statement to a mathematical solution without first developing a visual representation of the problem. For this reason, multimedia may be an effective tool to enhance students' success at solving problems. However, merely presenting a video of motion described in a problem is not necessarily the most effective method as was found in a recent study of students' responses on Web-based homework questions. Rather, multimedia-focused problems, where data relevant to solving the problem is embedded in a video or animation, may be the best use of multimedia in problem solving. Examples of multimedia-enhanced problems and multimedia-focused problems will be demonstrated, and their differences from "traditional" problems will be highlighted. Recommendations on the use of multimedia with problem solving and preliminary data on students' success at solving these problems will be discussed.

The Solving of Problems in Chemistry: the more open-ended problems

Science.gov (United States)

Reid, Norman; Yang, Mei-Jung

2002-01-01

Most problem solving in chemistry tends to be algorithmic in nature, while problems in life tend to be very open ended. This paper offers a simple classification of problems and seeks to explore the many factors which may be important in the successful solving of problems. It considers the place of procedures and algorithms. It analyses the role of long-term memory, not only in terms of what is known, but how that knowledge was acquired. It notes the great importance of the limitations of working memory space and the importance of confidence which comes from experience. Finally, various psychological factors are discussed. This paper argues that solving open-ended problems is extremely important in education and that offering learners experience of this in a group work context is a helpful way forward.

Development of a problem solving evaluation instrument; untangling of specific problem solving assets

Science.gov (United States)

Adams, Wendy Kristine

The purpose of my research was to produce a problem solving evaluation tool for physics. To do this it was necessary to gain a thorough understanding of how students solve problems. Although physics educators highly value problem solving and have put extensive effort into understanding successful problem solving, there is currently no efficient way to evaluate problem solving skill. Attempts have been made in the past; however, knowledge of the principles required to solve the subject problem are so absolutely critical that they completely overshadow any other skills students may use when solving a problem. The work presented here is unique because the evaluation tool removes the requirement that the student already have a grasp of physics concepts. It is also unique because I picked a wide range of people and picked a wide range of tasks for evaluation. This is an important design feature that helps make things emerge more clearly. This dissertation includes an extensive literature review of problem solving in physics, math, education and cognitive science as well as descriptions of studies involving student use of interactive computer simulations, the design and validation of a beliefs about physics survey and finally the design of the problem solving evaluation tool. I have successfully developed and validated a problem solving evaluation tool that identifies 44 separate assets (skills) necessary for solving problems. Rigorous validation studies, including work with an independent interviewer, show these assets identified by this content-free evaluation tool are the same assets that students use to solve problems in mechanics and quantum mechanics. Understanding this set of component assets will help teachers and researchers address problem solving within the classroom.

Augmented neural networks and problem structure-based heuristics for the bin-packing problem

Science.gov (United States)

Kasap, Nihat; Agarwal, Anurag

2012-08-01

In this article, we report on a research project where we applied augmented-neural-networks (AugNNs) approach for solving the classical bin-packing problem (BPP). AugNN is a metaheuristic that combines a priority rule heuristic with the iterative search approach of neural networks to generate good solutions fast. This is the first time this approach has been applied to the BPP. We also propose a decomposition approach for solving harder BPP, in which subproblems are solved using a combination of AugNN approach and heuristics that exploit the problem structure. We discuss the characteristics of problems on which such problem structure-based heuristics could be applied. We empirically show the effectiveness of the AugNN and the decomposition approach on many benchmark problems in the literature. For the 1210 benchmark problems tested, 917 problems were solved to optimality and the average gap between the obtained solution and the upper bound for all the problems was reduced to under 0.66% and computation time averaged below 33 s per problem. We also discuss the computational complexity of our approach.

Pet Problems at Home: Pet Problems in the Community.

Science.gov (United States)

Soltow, Willow

1984-01-01

Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

Degenerative diseases of the spine. Rare and often unrecognized causes of pain syndromes; Degenerative Erkrankungen der Wirbelsaeule. Seltene und oft verkannte Ursachen von Schmerzsyndromen

Energy Technology Data Exchange (ETDEWEB)

Baur-Melnyk, A.; Triantafyllou, M.; Reiser, M. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Institut fuer Klinische Radiologie, Muenchen (Germany); Birkenmaier, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Orthopaedische Klinik und Poliklinik (Germany)

2006-06-15

The aim of this article is to describe rare and often unrecognized causes of spinal pain syndromes. Intervertebral disc degeneration frequently appears in early adulthood and can have a symptomatic or asymptomatic course. This article discusses incidence, pathophysiology, imaging, and pain symptomatology involved in the origin of back pain. Anulus tears are often found in asymptomatic individuals but could be implicated in lumbar pain symptomatology in correlation with the provocative discography. Transient disorders can lead to pseudarthrosis of the iliac bone and to degeneration or to a reactive hypermobility with intervertebral disc degeneration in the level above. Modic type 1 erosive osteochondrosis is characterized by bone marrow edema near the hyaline cartilage end plate, which mostly elicits severe pain and results in serious limitations in everyday activities. The most important differential diagnosis is spondylodiscitis. Schmorl's nodes can exhibit considerable surrounding bone marrow edema that can be mistaken for metastases. A combination of MRI and CT should be employed for the diagnostic work-up of fatigue fracture of the interarticular portion, which is often overlooked due to its location. Synovial cysts of the facet joints can lead to radicular symptoms. Insufficiency fracture of the sacrum is frequently mistaken for metastasis due to intense scintigraphic enhancement and its signal behavior in MRI. CT provides instructive information. Differential diagnosis should include less common causes such as anulus tears, transient disorders, activated Schmorl's nodes, synovial cysts of the facet joints, fatigue fractures of the interarticular portion of the spine and the sacrum and distinguish from metastases in particular. (orig.) [German] Darstellung seltener und oft verkannter Ursachen von Wirbelsaeulenschmerzsyndromen. Eine Bandscheibendegeneration tritt haeufig im fruehen Erwachsenenalter auf und kann symptomatisch oder asymptomatisch

Problem specific heuristics for group scheduling problems in cellular manufacturing

OpenAIRE

Neufeld, Janis Sebastian

2016-01-01

The group scheduling problem commonly arises in cellular manufacturing systems, where parts are grouped into part families. It is characterized by a sequencing task on two levels: on the one hand, a sequence of jobs within each part family has to be identified while, on the other hand, a family sequence has to be determined. In order to solve this NP-hard problem usually heuristic solution approaches are used. In this thesis different aspects of group scheduling are discussed and problem spec...

On Euler's problem

International Nuclear Information System (INIS)

Egorov, Yurii V

2013-01-01

We consider the classical problem on the tallest column which was posed by Euler in 1757. Bernoulli-Euler theory serves today as the basis for the design of high buildings. This problem is reduced to the problem of finding the potential for the Sturm-Liouville equation corresponding to the maximum of the first eigenvalue. The problem has been studied by many mathematicians but we give the first rigorous proof of the existence and uniqueness of the optimal column and we give new formulae which let us find it. Our method is based on a new approach consisting in the study of critical points of a related nonlinear functional. Bibliography: 6 titles.

Noticing relevant problem features: activating prior knowledge affects problem solving by guiding encoding

Science.gov (United States)

Crooks, Noelle M.; Alibali, Martha W.

2013-01-01

This study investigated whether activating elements of prior knowledge can influence how problem solvers encode and solve simple mathematical equivalence problems (e.g., 3 + 4 + 5 = 3 + __). Past work has shown that such problems are difficult for elementary school students (McNeil and Alibali, 2000). One possible reason is that children's experiences in math classes may encourage them to think about equations in ways that are ultimately detrimental. Specifically, children learn a set of patterns that are potentially problematic (McNeil and Alibali, 2005a): the perceptual pattern that all equations follow an “operations = answer” format, the conceptual pattern that the equal sign means “calculate the total”, and the procedural pattern that the correct way to solve an equation is to perform all of the given operations on all of the given numbers. Upon viewing an equivalence problem, knowledge of these patterns may be reactivated, leading to incorrect problem solving. We hypothesized that these patterns may negatively affect problem solving by influencing what people encode about a problem. To test this hypothesis in children would require strengthening their misconceptions, and this could be detrimental to their mathematical development. Therefore, we tested this hypothesis in undergraduate participants. Participants completed either control tasks or tasks that activated their knowledge of the three patterns, and were then asked to reconstruct and solve a set of equivalence problems. Participants in the knowledge activation condition encoded the problems less well than control participants. They also made more errors in solving the problems, and their errors resembled the errors children make when solving equivalence problems. Moreover, encoding performance mediated the effect of knowledge activation on equivalence problem solving. Thus, one way in which experience may affect equivalence problem solving is by influencing what students encode about the

Problem representation and mathematical problem solving of students of varying math ability.

Science.gov (United States)

Krawec, Jennifer L

2014-01-01

The purpose of this study was to examine differences in math problem solving among students with learning disabilities (LD, n = 25), low-achieving students (LA, n = 30), and average-achieving students (AA, n = 29). The primary interest was to analyze the processes students use to translate and integrate problem information while solving problems. Paraphrasing, visual representation, and problem-solving accuracy were measured in eighth grade students using a researcher-modified version of the Mathematical Processing Instrument. Results indicated that both students with LD and LA students struggled with processing but that students with LD were significantly weaker than their LA peers in paraphrasing relevant information. Paraphrasing and visual representation accuracy each accounted for a statistically significant amount of variance in problem-solving accuracy. Finally, the effect of visual representation of relevant information on problem-solving accuracy was dependent on ability; specifically, for students with LD, generating accurate visual representations was more strongly related to problem-solving accuracy than for AA students. Implications for instruction for students with and without LD are discussed.

EFFECT OF PROBLEM BASED LEARNING AND MODEL CRITICAL THINKING ABILITY TO PROBLEM SOLVING SKILLS

Directory of Open Access Journals (Sweden)

Unita S. Zuliani Nasution

2016-12-01

Full Text Available The purposes of this research were to analyze the different between physic resolving problem ability by using problem based learning model and direct instruction model, the different of physic resolving problem ability between the students that have critical thinking ability upper the average and the students that have critical thinking ability under the average, and the interaction of problem based learning model toward critical thinking ability and students’ physic resolving problem ability. This research was quasy experimental research that use critical thinking ability tests and physic resolving problem ability tests as the instruments. Result of the research showed that the students’ physic resolving problem ability by using problem based learning model was better than by using direct instruction model, students’ physic resolving problem ability and critical thinking ability upper the average showed better different and result than students’ critical thinking ability under the average, besides there was an interaction between problem based learning model and critical thinking ability in improving students’ physic resolving problem ability.

The problem of criticality and initial-value problem in neutron transport theory

International Nuclear Information System (INIS)

Kyncl, J.

1984-10-01

The problem of criticality and the initial value problem are studied in the case of a linear Boltzmann equation and of both finite and infinite media. The space of functions where the problems are solved is chosen in such a way as to cover a wide range of physical situations. The asymptotic time behavior of the solution to the initial-value problem is also discussed, and main results are summarized in three basic theorems. (author)

Pre-Service Mathematics Teachers’ Problem Solving Processes with Geometer’s Sketchpad: Mirror Problem

OpenAIRE

ÖÇAL, Mehmet Fatih; ŞİMŞEK, Mertkan

2016-01-01

Problem solving skill is the core of mathematics education and its importance cannot be denied. This study specifically examined 56 freshmen pre-service mathematics teachers’ problem solving processes on a specific problem with the help of Geometer’s Sketchpad (GSP). They were grouped into two-person teams to solve a problem called "the mirror problem". They were expected to solve it by means of GSP. According to their works on GSP and related reflections, there appeared two differe...

Fostering Information Problem Solving Skills Through Completion Problems and Prompts

NARCIS (Netherlands)

Frerejean, Jimmy; Brand-Gruwel, Saskia; Kirschner, Paul A.

2012-01-01

Frerejean, J., Brand-Gruwel, S., & Kirschner, P. A. (2012, September). Fostering Information Problem Solving Skills Through Completion Problems and Prompts. Poster presented at the EARLI SIG 6 & 7 "Instructional Design" and "Learning and Instruction with Computers", Bari, Italy.

Semidefinite linear complementarity problems

International Nuclear Information System (INIS)

Eckhardt, U.

1978-04-01

Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

The Swedish drug problem: Conceptual understanding and problem handling, 1839–2011

Directory of Open Access Journals (Sweden)

Edman Johan

2014-12-01

Full Text Available AIM - To analyse the Swedish drug question by examining dominant concepts used to portray the problem in the years 1839-2011. Theoretically, we understand these concepts as ideological tools that shape the political initiatives and administrative efforts to deal with the problem. The study is based on two kinds of source material: articles in medical journals from the years 1839-1964 and public reports on vagrancy, the alcohol problem, mental health and the drug problem from the years 1882-2011.

The Elder Problem

Directory of Open Access Journals (Sweden)

John W. Elder

2017-03-01

Full Text Available This paper presents an autobiographical and biographical historical account of the genesis, evolution and resolution of the Elder Problem. It begins with John W. Elder and his autobiographical story leading to his groundbreaking work on natural convection at Cambridge in the 1960’s. His seminal work published in the Journal of Fluid Mechanics in 1967 became the basis for the modern benchmark of variable density flow simulators that we know today as “The Elder Problem”. There have been well known and major challenges with the Elder Problem model benchmark—notably the multiple solutions that were ultimately uncovered using different numerical models. Most recently, it has been shown that the multiple solutions are indeed physically realistic bifurcation solutions to the Elder Problem and not numerically spurious artefacts. The quandary of the Elder Problem has now been solved—a major scientific breakthrough for fluid mechanics and for numerical modelling. This paper—records, reflections, reminiscences, stories and anecdotes—is an historical autobiographical and biographical memoir. It is the personal story of the Elder Problem told by some of the key scientists who established and solved the Elder Problem. 2017 marks the 50 year anniversary of the classical work by John W. Elder published in Journal of Fluid Mechanics in 1967. This set the stage for this scientific story over some five decades. This paper is a celebration and commemoration of the life and times of John W. Elder, the problem named in his honour, and some of the key scientists who worked on, and ultimately solved, it.

Phase Transitions in Planning Problems: Design and Analysis of Parameterized Families of Hard Planning Problems

Science.gov (United States)

Hen, Itay; Rieffel, Eleanor G.; Do, Minh; Venturelli, Davide

2014-01-01

There are two common ways to evaluate algorithms: performance on benchmark problems derived from real applications and analysis of performance on parametrized families of problems. The two approaches complement each other, each having its advantages and disadvantages. The planning community has concentrated on the first approach, with few ways of generating parametrized families of hard problems known prior to this work. Our group's main interest is in comparing approaches to solving planning problems using a novel type of computational device - a quantum annealer - to existing state-of-the-art planning algorithms. Because only small-scale quantum annealers are available, we must compare on small problem sizes. Small problems are primarily useful for comparison only if they are instances of parametrized families of problems for which scaling analysis can be done. In this technical report, we discuss our approach to the generation of hard planning problems from classes of well-studied NP-complete problems that map naturally to planning problems or to aspects of planning problems that many practical planning problems share. These problem classes exhibit a phase transition between easy-to-solve and easy-to-show-unsolvable planning problems. The parametrized families of hard planning problems lie at the phase transition. The exponential scaling of hardness with problem size is apparent in these families even at very small problem sizes, thus enabling us to characterize even very small problems as hard. The families we developed will prove generally useful to the planning community in analyzing the performance of planning algorithms, providing a complementary approach to existing evaluation methods. We illustrate the hardness of these problems and their scaling with results on four state-of-the-art planners, observing significant differences between these planners on these problem families. Finally, we describe two general, and quite different, mappings of planning

Problems in differential equations

CERN Document Server

Brenner, J L

2013-01-01

More than 900 problems and answers explore applications of differential equations to vibrations, electrical engineering, mechanics, and physics. Problem types include both routine and nonroutine, and stars indicate advanced problems. 1963 edition.

Obstacle problems in mathematical physics

CERN Document Server

Rodrigues, J-F

1987-01-01

The aim of this research monograph is to present a general account of the applicability of elliptic variational inequalities to the important class of free boundary problems of obstacle type from a unifying point of view of classical Mathematical Physics.The first part of the volume introduces some obstacle type problems which can be reduced to variational inequalities. Part II presents some of the main aspects of the theory of elliptic variational inequalities, from the abstract hilbertian framework to the smoothness of the variational solution, discussing in general the properties of the free boundary and including some results on the obstacle Plateau problem. The last part examines the application to free boundary problems, namely the lubrication-cavitation problem, the elastoplastic problem, the Signorini (or the boundary obstacle) problem, the dam problem, the continuous casting problem, the electrochemical machining problem and the problem of the flow with wake in a channel past a profile.

Perbedaan Keterampilan Pemecahan Masalah pada Pembelajaran Fisika Menggunakan Metode Problem Posing dan Problem Solving

OpenAIRE

Rahman, Adetya; Hartini, Sri; An'nur, Syubhan

2015-01-01

Teachers should be able to choose the method of learning that can help students in learning physics, namely the method of problem posing and problem solving method. The purposes of this study are : (1) describe the learning physics skills by using problem posing method, (2) describe the learning physics skills by using problem solving method, and (3) know difference between learning physics skills by using problem posing method and problem solving method in class XI of Science SMAN 6 Banjarma...

ITOUGH2 sample problems

International Nuclear Information System (INIS)

Finsterle, S.

1997-11-01

This report contains a collection of ITOUGH2 sample problems. It complements the ITOUGH2 User's Guide [Finsterle, 1997a], and the ITOUGH2 Command Reference [Finsterle, 1997b]. ITOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media [Preuss, 1987, 1991a]. The report ITOUGH2 User's Guide [Finsterle, 1997a] describes the inverse modeling framework and provides the theoretical background. The report ITOUGH2 Command Reference [Finsterle, 1997b] contains the syntax of all ITOUGH2 commands. This report describes a variety of sample problems solved by ITOUGH2. Table 1.1 contains a short description of the seven sample problems discussed in this report. The TOUGH2 equation-of-state (EOS) module that needs to be linked to ITOUGH2 is also indicated. Each sample problem focuses on a few selected issues shown in Table 1.2. ITOUGH2 input features and the usage of program options are described. Furthermore, interpretations of selected inverse modeling results are given. Problem 1 is a multipart tutorial, describing basic ITOUGH2 input files for the main ITOUGH2 application modes; no interpretation of results is given. Problem 2 focuses on non-uniqueness, residual analysis, and correlation structure. Problem 3 illustrates a variety of parameter and observation types, and describes parameter selection strategies. Problem 4 compares the performance of minimization algorithms and discusses model identification. Problem 5 explains how to set up a combined inversion of steady-state and transient data. Problem 6 provides a detailed residual and error analysis. Finally, Problem 7 illustrates how the estimation of model-related parameters may help compensate for errors in that model

New Approach to Analyzing Physics Problems: A Taxonomy of Introductory Physics Problems

Science.gov (United States)

Teodorescu, Raluca E.; Bennhold, Cornelius; Feldman, Gerald; Medsker, Larry

2013-01-01

This paper describes research on a classification of physics problems in the context of introductory physics courses. This classification, called the Taxonomy of Introductory Physics Problems (TIPP), relates physics problems to the cognitive processes required to solve them. TIPP was created in order to design educational objectives, to develop…

Analysis of mathematical problem-solving ability based on metacognition on problem-based learning

Science.gov (United States)

Mulyono; Hadiyanti, R.

2018-03-01

Problem-solving is the primary purpose of the mathematics curriculum. Problem-solving abilities influenced beliefs and metacognition. Metacognition as superordinate capabilities can direct, regulate cognition and motivation and then problem-solving processes. This study aims to (1) test and analyzes the quality of problem-based learning and (2) investigate the problem-solving capabilities based on metacognition. This research uses mixed method study with The subject research are class XI students of Mathematics and Science at High School Kesatrian 2 Semarang which divided into tacit use, aware use, strategic use and reflective use level. The collecting data using scale, interviews, and tests. The data processed with the proportion of test, t-test, and paired samples t-test. The result shows that the students with levels tacit use were able to complete the whole matter given, but do not understand what and why a strategy is used. Students with aware use level were able to solve the problem, be able to build new knowledge through problem-solving to the indicators, understand the problem, determine the strategies used, although not right. Students on the Strategic ladder Use can be applied and adopt a wide variety of appropriate strategies to solve the issues and achieved re-examine indicators of process and outcome. The student with reflective use level is not found in this study. Based on the results suggested that study about the identification of metacognition in problem-solving so that the characteristics of each level of metacognition more clearly in a more significant sampling. Teachers need to know in depth about the student metacognitive activity and its relationship with mathematical problem solving and another problem resolution.

Simon on Problem-Solving

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

as a general approach to problem solving. We apply these Simonian ideas to organizational issues, specifically new organizational forms. Specifically, Simonian ideas allow us to develop a morphology of new organizational forms and to point to some design problems that characterize these forms.Keywords: Herbert...... Simon, problem-solving, new organizational forms. JEL Code: D23, D83......Two of Herbert Simon's best-known papers are "The Architecture of Complexity" and "The Structure of Ill-Structured Problems." We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

Errors in clinical laboratories or errors in laboratory medicine?

Science.gov (United States)

Plebani, Mario

2006-01-01

Laboratory testing is a highly complex process and, although laboratory services are relatively safe, they are not as safe as they could or should be. Clinical laboratories have long focused their attention on quality control methods and quality assessment programs dealing with analytical aspects of testing. However, a growing body of evidence accumulated in recent decades demonstrates that quality in clinical laboratories cannot be assured by merely focusing on purely analytical aspects. The more recent surveys on errors in laboratory medicine conclude that in the delivery of laboratory testing, mistakes occur more frequently before (pre-analytical) and after (post-analytical) the test has been performed. Most errors are due to pre-analytical factors (46-68.2% of total errors), while a high error rate (18.5-47% of total errors) has also been found in the post-analytical phase. Errors due to analytical problems have been significantly reduced over time, but there is evidence that, particularly for immunoassays, interference may have a serious impact on patients. A description of the most frequent and risky pre-, intra- and post-analytical errors and advice on practical steps for measuring and reducing the risk of errors is therefore given in the present paper. Many mistakes in the Total Testing Process are called "laboratory errors", although these may be due to poor communication, action taken by others involved in the testing process (e.g., physicians, nurses and phlebotomists), or poorly designed processes, all of which are beyond the laboratory's control. Likewise, there is evidence that laboratory information is only partially utilized. A recent document from the International Organization for Standardization (ISO) recommends a new, broader definition of the term "laboratory error" and a classification of errors according to different criteria. In a modern approach to total quality, centered on patients' needs and satisfaction, the risk of errors and mistakes

Problem-Based Learning: Student Engagement, Learning and Contextualized Problem-Solving. Occasional Paper

Science.gov (United States)

Mossuto, Mark

2009-01-01

The adoption of problem-based learning as a teaching method in the advertising and public relations programs offered by the Business TAFE (Technical and Further Education) School at RMIT University is explored in this paper. The effect of problem-based learning on student engagement, student learning and contextualised problem-solving was…

Investigating Mathematics Teachers Candidates' Knowledge about Problem Solving Strategies through Problem Posing

Science.gov (United States)

Ünlü, Melihan

2017-01-01

The aim of the study was to determine mathematics teacher candidates' knowledge about problem solving strategies through problem posing. This qualitative research was conducted with 95 mathematics teacher candidates studying at education faculty of a public university during the first term of the 2015-2016 academic year in Turkey. Problem Posing…

Pelvic floor muscle problems mediate sexual problems in young adult rape victims

NARCIS (Netherlands)

Postma, Riemke; Bicanic, Iva; van der Vaart, Huub; Laan, Ellen

2013-01-01

Prior studies have addressed sexual abuse and sexual function in adult women. No studies have focused on the effect of adolescence rape on sexual functioning. To investigate the effect of rape on sexual problems and on pelvic floor problems, as well as the mediating role of pelvic floor problems on

Parent-Reported Psychological and Sleep Problems in a Preschool-Aged Community Sample: Prevalence of Sleep Problems in Children with and without Emotional/Behavioural Problems

OpenAIRE

Salater, Julie; Røhr, Marthe

2010-01-01

Objective : To examine (a) the prevalence of sleep problems among 4-year-olds in the general population, (b) the prevalence of sleep problems among children with emotional and/or behavioural problems, and (c) whether specific sleep problems are associated with particular emotional/behavioural problems. Method: Using The Preschool Age Psychiatric Assessment (PAPA) , data about sleep and emotional/behavioural problems was obtained from 727 parents of 4-year-olds, recruited for a large...

Problem solving and problem strategies in the teaching and learning ...

African Journals Online (AJOL)

Perennial poor performance recorded annually in both internal and external examinations in Mathematics has been a great concern for the Mathematics Educators in Nigeria. This paper discusses problem-solving and influence of problem-solving strategies on students' performance in mathematics. The concept of ...

Students’ Mathematical Problem-Solving Abilities Through The Application of Learning Models Problem Based Learning

Science.gov (United States)

Nasution, M. L.; Yerizon, Y.; Gusmiyanti, R.

2018-04-01

One of the purpose mathematic learning is to develop problem solving abilities. Problem solving is obtained through experience in questioning non-routine. Improving students’ mathematical problem-solving abilities required an appropriate strategy in learning activities one of them is models problem based learning (PBL). Thus, the purpose of this research is to determine whether the problem solving abilities of mathematical students’ who learn to use PBL better than on the ability of students’ mathematical problem solving by applying conventional learning. This research included quasi experiment with static group design and population is students class XI MIA SMAN 1 Lubuk Alung. Class experiment in the class XI MIA 5 and class control in the class XI MIA 6. The instrument of final test students’ mathematical problem solving used essay form. The result of data final test in analyzed with t-test. The result is students’ mathematical problem solving abilities with PBL better then on the ability of students’ mathematical problem solving by applying conventional learning. It’s seen from the high percentage achieved by the group of students who learn to use PBL for each indicator of students’ mathematical problem solving.

Problem-solving with multiple interdependent criteria: better solution to complex problems

International Nuclear Information System (INIS)

Carlsson, C.; Fuller, R.

1996-01-01

We consider multiple objective programming (MOP) problems with additive interdependencies, this is when the states of some chosen objective are attained through supportive or inhibitory feed-backs from several other objectives. MOP problems with independent objectives (when the cause-effect relations between the decision variables and the objectives are completely known) will be treated as special cases of the MOP in which we have interdependent objectives. We illustrate our ideas by a simple three-objective real-life problem

The rational complementarity problem

NARCIS (Netherlands)

Heemels, W.P.M.H.; Schumacher, J.M.; Weiland, S.

1999-01-01

An extension of the linear complementarity problem (LCP) of mathematical programming is the so-called rational complementarity problem (RCP). This problem occurs if complementarity conditions are imposed on input and output variables of linear dynamical input/state/output systems. The resulting

The Effect of Problem Solving and Problem Posing Models and Innate Ability to Students Achievement

Directory of Open Access Journals (Sweden)

Ratna Kartika Irawati

2015-04-01

Full Text Available Pengaruh Model Problem Solving dan Problem Posing serta Kemampuan Awal terhadap Hasil Belajar Siswa   Abstract: Chemistry concepts understanding features abstract quality and requires higher order thinking skills. Yet, the learning on chemistry has not boost the higher order thinking skills of the students. The use of the learning model of Problem Solving and Problem Posing in observing the innate ability of the student is expected to resolve the issue. This study aims to determine the learning model which is effective to improve the study of the student with different level of innate ability. This study used the quasi-experimental design. The research data used in this research is the quiz/test of the class which consist of 14 multiple choice questions and 5 essay questions. The data analysis used is ANOVA Two Ways. The results showed that Problem Posing is more effective to improve the student compared to Problem Solving, students with high level of innate ability have better outcomes in learning rather than the students with low level of innate ability after being applied with the Problem solving and Problem posing model, further, Problem Solving and Problem Posing is more suitable to be applied to the students with high level of innate ability. Key Words: problem solving, problem posing, higher order thinking skills, innate ability, learning outcomes   Abstrak: Pemahaman konsep-konsep kimia yang bersifat abstrak membutuhkan keterampilan berpikir tingkat tinggi. Pembelajaran kimia belum mendorong siswa melakukan keterampilan berpikir tingkat tinggi. Penggunaan model pembelajaran Problem Solving dan Problem Posing dengan memperhatikan kemampuan awal siswa diduga dapat mengatasi masalah tersebut. Penelitian ini bertujuan untuk mengetahui model pembelajaran yang efektif dalam meningkatkan hasil belajar dengan kemampuan awal siswa yang berbeda. Penelitian ini menggunakan rancangan eksperimen semu. Data penelitian menggunakan tes hasil belajar

Diagrams benefit symbolic problem-solving.

Science.gov (United States)

Chu, Junyi; Rittle-Johnson, Bethany; Fyfe, Emily R

2017-06-01

The format of a mathematics problem often influences students' problem-solving performance. For example, providing diagrams in conjunction with story problems can benefit students' understanding, choice of strategy, and accuracy on story problems. However, it remains unclear whether providing diagrams in conjunction with symbolic equations can benefit problem-solving performance as well. We tested the impact of diagram presence on students' performance on algebra equation problems to determine whether diagrams increase problem-solving success. We also examined the influence of item- and student-level factors to test the robustness of the diagram effect. We worked with 61 seventh-grade students who had received 2 months of pre-algebra instruction. Students participated in an experimenter-led classroom session. Using a within-subjects design, students solved algebra problems in two matched formats (equation and equation-with-diagram). The presence of diagrams increased equation-solving accuracy and the use of informal strategies. This diagram benefit was independent of student ability and item complexity. The benefits of diagrams found previously for story problems generalized to symbolic problems. The findings are consistent with cognitive models of problem-solving and suggest that diagrams may be a useful additional representation of symbolic problems. © 2017 The British Psychological Society.

Modified and fuzzified general problem solver for 'monkey and banana' problem

International Nuclear Information System (INIS)

Sano, Norihide; Takahashi, Ryoichi.

1994-01-01

Automatic operation is important for the in-service inspection of nuclear power stations of the decommission of retired plants. Master and slave control will be introduced for work-robot control. It is desirable that the slave possess problem-solving capabilities. In this paper we assume that the slave incorporates the general problem solver (GPS) algorithm. In view of having solved the 'monkey and banana' problem, the slave system is regarded as reasonable alternative which incorporates the capability of problem-solving. Basically, the GPS solves a problem by reducing the difference between the initial state and goal state, and hence the performance of GPS depends on selection of the difference to be reduced. The conventional GPS is given the order of importance of the differences in advance. In this study, the GPS was improved by making use of the rules which determine the order. When several choices are available for the given difference, a fuzzified decision to determine the necessary action is made, as demonstrated in this paper. (author)

The vanishing discount problem and viscosity Mather measures. Part 2: boundary value problems

OpenAIRE

Ishii, Hitoshi; Mitake, Hiroyoshi; Tran, Hung V.

2016-01-01

In arXiv:1603.01051 (Part 1 of this series), we have introduced a variational approach to studying the vanishing discount problem for fully nonlinear, degenerate elliptic, partial differential equations in a torus. We develop this approach further here to handle boundary value problems. In particular, we establish new representation formulas for solutions of discount problems, critical values, and use them to prove convergence results for the vanishing discount problems.

How does maternal oxytocin influence children's mental health problem and maternal mental health problem?

Science.gov (United States)

Tse, Wai S; Siu, Angela F Y; Wong, Tracy K Y

2017-12-01

This study aims to explore the interrelationship among maternal oxytocin (OT) responsiveness, maternal mental health, maternal parenting behavior, and mental health of children under a free-play interaction. 61 mother-child dyads were recruited for the study. Maternal mental health problem and parenting self-efficacy were measured using self-reported questionnaires. The mental health problems of children were also evaluated using a mother-reported questionnaire. Furthermore, salivary OT was collected before and after a standardized 10min free-play interaction. Parenting behaviors, including eye gaze and touch, were measured during the free-play interaction. Maternal OT responsiveness was significantly associated with less maternal mental health problem, touch frequency, and mental health problem of children but not with parenting self-efficacy. In the multivariate linear regression analysis that considers maternal OT responsiveness and maternal and children's mental health problems, maternal OT responsiveness was not associated with the mental health problems of children. This result suggested that maternal mental health problem played a mediational role between maternal OT responsiveness and the mental health problem of children. Results supported the assertion that maternal OT responsiveness contributed to the increased risk of maternal mental health problems and, subsequently, the risk of mental health problems of their children. Copyright © 2017 Elsevier B.V. All rights reserved.

Pollution problems plague Poland

International Nuclear Information System (INIS)

Bajsarowicz, J.F.

1989-01-01

Poland's environmental problems are said to stem from investments in heavy industries that require enormous quantities of power and from the exploitation of two key natural resources: coal and sulfur. Air and water pollution problems and related public health problems are discussed

Study the Problem.

Science.gov (United States)

Choate, Joyce S.

1990-01-01

The initial step of a strategic process for solving mathematical problems, "studying the question," is discussed. A lesson plan for teaching students to identify and revise arithmetic problems is presented, involving directed instruction and supervised practice. (JDD)

The art of problem posing

CERN Document Server

Brown, Stephen I

1990-01-01

Updated and expanded, this second edition satisfies the same philosophical objective as the first -- to show the importance of problem posing. Although interest in mathematical problem solving increased during the past decade, problem posing remained relatively ignored. The Art of Problem Posing draws attention to this equally important act and is the innovator in the field. Special features include: * an exploration ofthe logical relationship between problem posing and problem solving * a special chapter devoted to teaching problem posing as a separate course * sketches, drawings, diagrams, and cartoons that illustrate the schemes proposed * a special section on writing in mathematics.

Reproductive autonomy, the non-identity problem, and the non-person problem.

Science.gov (United States)

DiSilvestro, Russell

2009-01-01

The Non-Identity Problem is the problem of explaining the apparent wrongness of a decision that does not harm people, especially since some of the people affected by the decision would not exist at all were it not for the decision. One approach to this problem, in the context of reproductive decisions, is to focus on wronging, rather than harming, one's offspring. But a Non-Person Problem emerges for any view that claims (1) that only persons can be wronged and (2) that the person-making properties allow for there to be human non-persons. Consider an individual human organism that is prevented from ever possessing the person-making properties. On person-only accounts of the victims of wronging, this organism cannot be wronged by anyone. Hence even individuals whose decisions prevent it from ever possessing the person-making properties cannot wrong it. But this is counter-intuitive. We can think of examples where a human organism is wronged by precisely those decisions that prevent it from possessing the person-making properties. The best solution to this problem, in the case where the person-making property is rational self-governance in pursuit of a meaningful life, is to adjust the concept of a person so that it refers, not merely to those with the immediate capacity for rational self-governance in pursuit of a meaningful life, but also to those with a higher-order capacity for such self-governance. Any solution to the Non-Identity Problem that focuses on wronging rather than harming should incorporate this sort of solution to the Non-Person Problem.

Croatian Society of Medical Biochemistry and Laboratory Medicine: national recommendations for venous blood sampling.

Science.gov (United States)

Nikolac, Nora; Supak-Smolcić, Vesna; Simundić, Ana-Maria; Celap, Ivana

2013-01-01

Phlebotomy is one of the most complex medical procedures in the diagnosis, management and treatment of patients in healthcare. Since laboratory test results are the basis for a large proportion (60-80%) of medical decisions, any error in the phlebotomy process could have serious consequences. In order to minimize the possibility of errors, phlebotomy procedures should be standardised, well-documented and written instructions should be available at every workstation. Croatia is one of the few European countries that have national guidelines for phlebotomy, besides the universally used CLSI (Clinical Laboratory Standards Institute) H3-A6 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; approved Standard-Sixth Edition (CLSI, 2007) and WHO (World Health Organization) guidelines on drawing blood: best practices in phlebotomy (WHO, 2010). However, the growing body of evidence in importance of preanalytical phase management resulted in a need for evidence based revision and expansion of existing recommendations. The Croatian Society for Medical Biochemistry and Laboratory Medicine, Working Group for the Preanalytical Phase issued this recommendation. This document is based on the CLSI guideline H3-A6, with significant differences and additional information.

Consensus Guidelines for CSF and Blood Biobanking for CNS Biomarker Studies

Directory of Open Access Journals (Sweden)

Charlotte E. Teunissen

2011-01-01

Full Text Available There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in cerebrospinal fluid (CSF are being used in clinical practice. Anti-aquaporin-4 antibodies in serum are currently useful for the diagnosis of neuromyelitis optica (NMO, but we could expect novel CSF biomarkers that help define prognosis and response to treatment for this disease. One of the most critical factors in biomarker research is the inadequate powering of studies performed by single centers. Collaboration between investigators is needed to establish large biobanks of well-defined samples. A key issue in collaboration is to establish standardized protocols for biobanking to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by pre-analytical factors. Here, consensus guidelines for CSF collection and biobanking are presented, based on the guidelines that have been published by the BioMS-eu network for CSF biomarker research. We focussed on CSF collection procedures, pre-analytical factors and high quality clinical and paraclinical information. Importantly, the biobanking protocols are applicable for CSF biobanks for research targeting any neurological disease.

GI-POP: a combinational annotation and genomic island prediction pipeline for ongoing microbial genome projects.

Science.gov (United States)

Lee, Chi-Ching; Chen, Yi-Ping Phoebe; Yao, Tzu-Jung; Ma, Cheng-Yu; Lo, Wei-Cheng; Lyu, Ping-Chiang; Tang, Chuan Yi

2013-04-10

Sequencing of microbial genomes is important because of microbial-carrying antibiotic and pathogenetic activities. However, even with the help of new assembling software, finishing a whole genome is a time-consuming task. In most bacteria, pathogenetic or antibiotic genes are carried in genomic islands. Therefore, a quick genomic island (GI) prediction method is useful for ongoing sequencing genomes. In this work, we built a Web server called GI-POP (http://gipop.life.nthu.edu.tw) which integrates a sequence assembling tool, a functional annotation pipeline, and a high-performance GI predicting module, in a support vector machine (SVM)-based method called genomic island genomic profile scanning (GI-GPS). The draft genomes of the ongoing genome projects in contigs or scaffolds can be submitted to our Web server, and it provides the functional annotation and highly probable GI-predicting results. GI-POP is a comprehensive annotation Web server designed for ongoing genome project analysis. Researchers can perform annotation and obtain pre-analytic information include possible GIs, coding/non-coding sequences and functional analysis from their draft genomes. This pre-analytic system can provide useful information for finishing a genome sequencing project. Copyright © 2012 Elsevier B.V. All rights reserved.

Solved problems in electrochemistry

International Nuclear Information System (INIS)

Piron, D.L.

2004-01-01

This book presents calculated solutions to problems in fundamental and applied electrochemistry. It uses industrial data to illustrate scientific concepts and scientific knowledge to solve practical problems. It is subdivided into three parts. The first uses modern basic concepts, the second studies the scientific basis for electrode and electrolyte thermodynamics (including E-pH diagrams and the minimum energy involved in transformations) and the kinetics of rate processes (including the energy lost in heat and in parasite reactions). The third part treats larger problems in electrolysis and power generation, as well as in corrosion and its prevention. Each chapter includes three sections: the presentation of useful principles; some twenty problems with their solutions; and, a set of unsolved problems

Classifying IS Project Problems

DEFF Research Database (Denmark)

Munk-Madsen, Andreas

2006-01-01

The literature contains many lists of IS project problems, often in the form of risk factors. The problems sometimes appear unordered and overlapping, which reduces their usefulness to practitioners as well as theoreticians. This paper proposes a list of criteria for formulating project problems...

Time Dependent Heterogeneous Vehicle Routing Problem for Catering Service Delivery Problem

Science.gov (United States)

Azis, Zainal; Mawengkang, Herman

2017-09-01

The heterogeneous vehicle routing problem (HVRP) is a variant of vehicle routing problem (VRP) which describes various types of vehicles with different capacity to serve a set of customers with known geographical locations. This paper considers the optimal service deliveries of meals of a catering company located in Medan City, Indonesia. Due to the road condition as well as traffic, it is necessary for the company to use different type of vehicle to fulfill customers demand in time. The HVRP incorporates time dependency of travel times on the particular time of the day. The objective is to minimize the sum of the costs of travelling and elapsed time over the planning horizon. The problem can be modeled as a linear mixed integer program and we address a feasible neighbourhood search approach to solve the problem.

Reconfigurable layout problem

NARCIS (Netherlands)

Meng, G.; Heragu, S.S.; Heragu, S.S.; Zijm, Willem H.M.

2004-01-01

This paper addresses the reconfigurable layout problem, which differs from traditional, robust and dynamic layout problems mainly in two aspects: first, it assumes that production data are available only for the current and upcoming production period. Second, it considers queuing performance

Cultural Dysthymia: An Unrecognized Disorder among African Americans?

Science.gov (United States)

Vontress, Clemmont E.; Woodland, Calvin E.; Epp, Lawrence

2007-01-01

Many African Americans experience low-grade depression, referred to as dysthymia in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000). After more than 250 years of enslavement, prejudice, and discrimination, dysthymia is reflected in chronic low-grade sadness, anger, hostility,…

Rhabdomyolysis Complicating Unrecognized Hypophosphatemia in an Alcoholic Patient

Directory of Open Access Journals (Sweden)

Deepali Kumar

1999-01-01

Full Text Available Rhabdomyolysis occurring as a complication of hypophosphatemia has been infrequently described. A 58-year-old male with a history of daily alcohol consumption presented with two generalized tonic clonic seizures secondary to hypovolemic hyponatremia. He was volume-resuscitated, and antiepileptic medication was administered. After three days of hospitalization, the patient developed severe rhabdomyolysis despite the absence of further seizure activity. Serum phosphate levels were depressed. He was treated with intravenous mannitol, alkaline diuresis, and intravenous and oral phosphate supplementation. He recovered uneventfully. Hypophosphatemia can potentially lead to multisystem organ dysfunction including severe rhabdomyolysis. It is, therefore, important to maintain a low threshold for measuring serum phosphate levels in patients admitted to hospital.

A Problem-Reduction Evolutionary Algorithm for Solving the Capacitated Vehicle Routing Problem

Directory of Open Access Journals (Sweden)

Wanfeng Liu

2015-01-01

Full Text Available Assessment of the components of a solution helps provide useful information for an optimization problem. This paper presents a new population-based problem-reduction evolutionary algorithm (PREA based on the solution components assessment. An individual solution is regarded as being constructed by basic elements, and the concept of acceptability is introduced to evaluate them. The PREA consists of a searching phase and an evaluation phase. The acceptability of basic elements is calculated in the evaluation phase and passed to the searching phase. In the searching phase, for each individual solution, the original optimization problem is reduced to a new smaller-size problem. With the evolution of the algorithm, the number of common basic elements in the population increases until all individual solutions are exactly the same which is supposed to be the near-optimal solution of the optimization problem. The new algorithm is applied to a large variety of capacitated vehicle routing problems (CVRP with customers up to nearly 500. Experimental results show that the proposed algorithm has the advantages of fast convergence and robustness in solution quality over the comparative algorithms.

An algorithm for the split-feasibility problems with application to the split-equality problem.

Science.gov (United States)

Chuang, Chih-Sheng; Chen, Chi-Ming

2017-01-01

In this paper, we study the split-feasibility problem in Hilbert spaces by using the projected reflected gradient algorithm. As applications, we study the convex linear inverse problem and the split-equality problem in Hilbert spaces, and we give new algorithms for these problems. Finally, numerical results are given for our main results.

Non-integrability of the Anisotropic Stormer Problem and the Isosceles Three-Body Problem

Science.gov (United States)

Nomikos, D. G.; Papageorgiou, V. G.

2009-02-01

We study the Anisotropic Stormer Problem (ASP) and the Isosceles Three-Body Problem (IP), from the viewpoint of integrability, using Morales-Ramis theory and its generalization. The study of their integrability presents particular interest since they model important physical phenomena. Both problems can be reduced with respect to the S1 symmetry. Almeida and Stuchi [M.A. Almeida, T.J. Stuchi, Non-integrability of the anisotropic Stormer problem with angular momentum, Physica D 189 (2004) 219-233] proved that the reduced ASP is non-integrable for almost all values of the parameters. In this paper we establish the non-integrability (in the extended Liouville sense) of the remaining cases. The IP is a special case of the three-body problem and it can be considered as a generalization of the Sitnikov problem. Here we prove that the complexified reduced IP does not admit an additional independent meromorphic first integral.

The triangle scheduling problem

NARCIS (Netherlands)

Dürr, Christoph; Hanzálek, Zdeněk; Konrad, Christian; Seddik, Yasmina; Sitters, R.A.; Vásquez, Óscar C.; Woeginger, Gerhard

2017-01-01

This paper introduces a novel scheduling problem, where jobs occupy a triangular shape on the time line. This problem is motivated by scheduling jobs with different criticality levels. A measure is introduced, namely the binary tree ratio. It is shown that the Greedy algorithm solves the problem to

Mechanics problems in undergraduate physics

CERN Document Server

Strelkov, S P

2013-01-01

Problems in Undergraduate Physics, Volume I: Mechanics focuses on solutions to problems in physics. The book first discusses the fundamental problems in physics. Topics include laws of conservation of momentum and energy; dynamics of a point particle in circular motion; dynamics of a rotating rigid body; hydrostatics and aerostatics; and acoustics. The text also offers information on solutions to problems in physics. Answers to problems in kinematics, statics, gravity, elastic deformations, vibrations, and hydrostatics and aerostatics are discussed. Solutions to problems related to the laws of

Simon on problem solving

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

2006-01-01

as a general approach to problem solving. We apply these Simonian ideas to organisational issues, specifically new organisational forms. Specifically, Simonian ideas allow us to develop a morphology of new organisational forms and to point to some design problems that characterise these forms.......Two of Herbert Simon's best-known papers are 'The Architecture of Complexity' and 'The Structure of Ill-Structured Problems.' We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

Art as metontological problem

Directory of Open Access Journals (Sweden)

Radovanović Saša Ž.

2014-01-01

Full Text Available The author explains the link between fundamental ontology and metontology in Heidegger's thought. In this context, he raises the question about art as a metontological problem. Then he goes to show that the problem of metontology stems from imanent transformation of fundamental ontology. In this sense, two aspects of the problem of existence assume relevance, namely, universality and radicalism. He draws the conclusion that metontology and art as its problem, as opposed to fundamental ontology, were not integrated into Heidegger's later thought.

Problems in equilibrium theory

CERN Document Server

Aliprantis, Charalambos D

1996-01-01

In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

The three-body problem

International Nuclear Information System (INIS)

Musielak, Z E; Quarles, B

2014-01-01

The three-body problem, which describes three masses interacting through Newtonian gravity without any restrictions imposed on the initial positions and velocities of these masses, has attracted the attention of many scientists for more than 300 years. In this paper, we present a review of the three-body problem in the context of both historical and modern developments. We describe the general and restricted (circular and elliptic) three-body problems, different analytical and numerical methods of finding solutions, methods for performing stability analysis and searching for periodic orbits and resonances. We apply the results to some interesting problems of celestial mechanics. We also provide a brief presentation of the general and restricted relativistic three-body problems, and discuss their astronomical applications. (review article)

Stability of purgeable VOCs in water samples during pre-analytical holding: Part 1, Analysis by a commercial laboratory

Energy Technology Data Exchange (ETDEWEB)

West, O.R.; Bayne, C.K.; Siegrist, R.L.; Holden, W.L.; Scarborough, S.S. [Oak Ridge National Lab., TN (United States); Bottrell, D.W. [USDOE, Washington, DC (United States)

1996-10-01

This study was undertaken to examine the hypothesis that prevalent and priority purgeable VOCs in properly preserved water samples are stable for at least 28 days. (VOCs are considered stable if concentrations do not change by more than 10%.) Surface water was spiked with 44 purgeable VOCs. Results showed that the measurement of 35 out of 44 purgeable VOCs in properly preserved water samples (4 C, 250 mg NaHSO{sub 4}, no headspace in 40 mL VOC vials with 0.010-in. Teflon-lined silicone septum caps) will not be affected by sample storage for 28 days. Larger changes (>10%) and low practical reporting times were observed for a few analytes, e.g. acrolein, CS{sub 2}, vinyl acetate, etc.; these also involve other analytical problems. Advantages of a 28-day (compared to 14-day) holding time are pointed out.

Word Problem Wizardry.

Science.gov (United States)

Cassidy, Jack

1991-01-01

Presents suggestions for teaching math word problems to elementary students. The strategies take into consideration differences between reading in math and reading in other areas. A problem-prediction game and four self-checking activities are included along with a magic password challenge. (SM)

On the graph turnpike problem

KAUST Repository

Feder, Tomá s; Motwani, Rajeev

2009-01-01

Results on graph turnpike problem without distinctness, including its NP-completeness, and an O(m+n log n) algorithm, is presented. The usual turnpike problem has all pairwise distances given, but does not specify which pair of vertices w e corresponds to. There are two other problems that can be viewed as special cases of the graph turnpike problem, including the bandwidth problem and the low-distortion graph embedding problem. The aim for the turnpike problem in the NP-complete is to orient the edges with weights w i in either direction so that when the whole cycle is transversed in the real line, it returns to a chosen starting point for the cycle. An instance of the turnpike problem with or without distinctness is uniquely mappable if there exists at most one solution up to translation and choice of orientation.

On the graph turnpike problem

KAUST Repository

Feder, Tomás

2009-06-01

Results on graph turnpike problem without distinctness, including its NP-completeness, and an O(m+n log n) algorithm, is presented. The usual turnpike problem has all pairwise distances given, but does not specify which pair of vertices w e corresponds to. There are two other problems that can be viewed as special cases of the graph turnpike problem, including the bandwidth problem and the low-distortion graph embedding problem. The aim for the turnpike problem in the NP-complete is to orient the edges with weights w i in either direction so that when the whole cycle is transversed in the real line, it returns to a chosen starting point for the cycle. An instance of the turnpike problem with or without distinctness is uniquely mappable if there exists at most one solution up to translation and choice of orientation.

Using Problem-solving Therapy to Improve Problem-solving Orientation, Problem-solving Skills and Quality of Life in Older Hemodialysis Patients.

Science.gov (United States)

Erdley-Kass, Shiloh D; Kass, Darrin S; Gellis, Zvi D; Bogner, Hillary A; Berger, Andrea; Perkins, Robert M

2017-08-24

To determine the effectiveness of Problem-Solving Therapy (PST) in older hemodialysis (HD) patients by assessing changes in health-related quality of life and problem-solving skills. 33 HD patients in an outpatient hemodialysis center without active medical and psychiatric illness were enrolled. The intervention group (n = 15) received PST from a licensed social worker for 6 weeks, whereas the control group (n = 18) received usual care treatment. In comparison to the control group, patients receiving PST intervention reported improved perceptions of mental health, were more likely to view their problems with a positive orientation and were more likely to use functional problem-solving methods. Furthermore, this group was also more likely to view their overall health, activity limits, social activities and ability to accomplish desired tasks with a more positive mindset. The results demonstrate that PST may positively impact mental health components of quality of life and problem-solving coping among older HD patients. PST is an effective, efficient, and easy to implement intervention that can benefit problem-solving abilities and mental health-related quality of life in older HD patients. In turn, this will help patients manage their daily living activities related to their medical condition and reduce daily stressors.

Addressing problems of employee performance.

Science.gov (United States)

McConnell, Charles R

2011-01-01

Employee performance problems are essentially of 2 kinds: those that are motivational in origin and those resulting from skill deficiencies. Both kinds of problems are the province of the department manager. Performance problems differ from problems of conduct in that traditional disciplinary processes ordinarily do not apply. Rather, performance problems are addressed through educational and remedial processes. The manager has a basic responsibility in ensuring that everything reasonable is done to help each employee succeed. There are a number of steps the manager can take to address employee performance problems.

A New Iterative Method for Equilibrium Problems and Fixed Point Problems

Directory of Open Access Journals (Sweden)

Abdul Latif

2013-01-01

Full Text Available Introducing a new iterative method, we study the existence of a common element of the set of solutions of equilibrium problems for a family of monotone, Lipschitz-type continuous mappings and the sets of fixed points of two nonexpansive semigroups in a real Hilbert space. We establish strong convergence theorems of the new iterative method for the solution of the variational inequality problem which is the optimality condition for the minimization problem. Our results improve and generalize the corresponding recent results of Anh (2012, Cianciaruso et al. (2010, and many others.

THE PROBLEM OF SUPPLIER

OpenAIRE

Raffo Lecca, Eduardo

2014-01-01

This is a famous problem from the annals of literature in operations research. G. Dantzig in [1] refers to W.W. Jacobs with his paper "The Caterer Problem" Nav. Log Res. Quart. 1 1954; as well as Gaddum, Hoffman and Sokolowsky "On the Solution of the Caterer Problem" Naval Res Logist. Quart., Vol.1, No. 3, september, 1954, and William Prager "On the Caterer Problem" of Management Sci, Vol 3, No. 1 october 1956 and Management Sci, Vol 3, No. 2 january 1957. Subsequently both G. Hadley presents...

The Problem of Evil

OpenAIRE

Araki,Naoki

2018-01-01

The Problem of Evil has been discussed as one of the major problems in monotheism. “Why does Almighty God allow evil to exist?” Various solutions to this problem have been proposed, including the Free Will Defence. But none of them is convincing. The Problem of Evil has an assumption, which is that God exists. One of the proofs of God’s existence is René Descartes’s Ontological Argument. But none of them is persuasive. Every logic has its own assumption, which needs to be verified. So this pr...

Adaptive Problem Solving

Science.gov (United States)

2017-03-01

Borrajo and Raquel Fuentetaja, Universidad Carlos III de Madrid on the meta-level search architecture for finding good combinations of representations and...heuristics on a problem-by-problem basis. The other is with Carlos Linares also from Universidad Carlos III de Madrid on developing effective

Problems in abstract algebra

CERN Document Server

Wadsworth, A R

2017-01-01

This is a book of problems in abstract algebra for strong undergraduates or beginning graduate students. It can be used as a supplement to a course or for self-study. The book provides more variety and more challenging problems than are found in most algebra textbooks. It is intended for students wanting to enrich their learning of mathematics by tackling problems that take some thought and effort to solve. The book contains problems on groups (including the Sylow Theorems, solvable groups, presentation of groups by generators and relations, and structure and duality for finite abelian groups); rings (including basic ideal theory and factorization in integral domains and Gauss's Theorem); linear algebra (emphasizing linear transformations, including canonical forms); and fields (including Galois theory). Hints to many problems are also included.

Calculus problems

CERN Document Server

Baronti, Marco; van der Putten, Robertus; Venturi, Irene

2016-01-01

This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

The Complete Problem Solver.

Science.gov (United States)

Hayes, John R.

This book, designed for a college course on general problem-solving skills, focuses on skills that can be used by anyone in solving problems that occur in everyday life. Part I considers theory and practice: understanding problems, search, and protocol analysis. Part II discusses memory and knowledge acquisition: the structure of human memory,…

Diabetes and Sexual and Urologic Problems

Science.gov (United States)

... Disease, & Other Dental Problems Diabetes, Sexual, & Bladder Problems Diabetes, Sexual, & Bladder Problems Sexual problems and bladder problems ... Can sexual and bladder problems be symptoms of diabetes? Yes. Changes in sexual function or bladder habits ...

Assessing student written problem solutions: A problem-solving rubric with application to introductory physics

Science.gov (United States)

Docktor, Jennifer L.; Dornfeld, Jay; Frodermann, Evan; Heller, Kenneth; Hsu, Leonardo; Jackson, Koblar Alan; Mason, Andrew; Ryan, Qing X.; Yang, Jie

2016-06-01

Problem solving is a complex process valuable in everyday life and crucial for learning in the STEM fields. To support the development of problem-solving skills it is important for researchers and curriculum developers to have practical tools that can measure the difference between novice and expert problem-solving performance in authentic classroom work. It is also useful if such tools can be employed by instructors to guide their pedagogy. We describe the design, development, and testing of a simple rubric to assess written solutions to problems given in undergraduate introductory physics courses. In particular, we present evidence for the validity, reliability, and utility of the instrument. The rubric identifies five general problem-solving processes and defines the criteria to attain a score in each: organizing problem information into a Useful Description, selecting appropriate principles (Physics Approach), applying those principles to the specific conditions in the problem (Specific Application of Physics), using Mathematical Procedures appropriately, and displaying evidence of an organized reasoning pattern (Logical Progression).

Impact of Context-Rich, Multifaceted Problems on Students' Attitudes Towards Problem-Solving

Science.gov (United States)

Ogilvie, Craig

2008-04-01

Young scientists and engineers need strong problem-solving skills to enable them to address the broad challenges they will face in their careers. These challenges will likely be ill-defined and open-ended with either unclear goals, insufficient constraints, multiple possible solutions, and different criteria for evaluating solutions so that our young scientists and engineers must be able to make judgments and defend their proposed solutions. In contrast, many students believe that problem-solving is being able to apply set procedures or algorithms to tasks and that their job as students is to master an ever-increasing list of procedures. This gap between students' beliefs and the broader, deeper approaches of experts is a strong barrier to the educational challenge of preparing students to succeed in their future careers. To start to address this gap, we have used multi-faceted, context-rich problems in a sophomore calculus-based physics course. To assess whether there was any change in students' attitudes or beliefs towards problem-solving, students were asked to reflect on their problem-solving at the beginning and at the end of the semester. These reflections were coded as containing one or more problem-solving ideas. The change in students' beliefs will be shown in this talk.

Encouraging Sixth-Grade Students' Problem-Solving Performance by Teaching through Problem Solving

Science.gov (United States)

Bostic, Jonathan D.; Pape, Stephen J.; Jacobbe, Tim

2016-01-01

This teaching experiment provided students with continuous engagement in a problem-solving based instructional approach during one mathematics unit. Three sections of sixth-grade mathematics were sampled from a school in Florida, U.S.A. and one section was randomly assigned to experience teaching through problem solving. Students' problem-solving…

Consideration of the official recognition of victims of environmental pollution. I. Environmental pollution in Toroku

Energy Technology Data Exchange (ETDEWEB)

Ota, T; Goto, M; Ryuraku, Y; Une, H; Ogawa, T; Goda, S

1975-04-01

The Toroku area in Miyazaki Prefecture has been appointed for special consideration of air-pollution related health disturbance victims and 48 inhabitants were selected for repeated medical examinations since 1971. The morbidities of subjective symptoms between a recognized group air pollution victims and an unrecognized group showed almost no difference. According to medical examinations, symptoms such as swelling of liver, decrease of sensation in the upper extremities, and decrease of sense of pain were very prevalent in both groups. Health problems in this area are due to arsenic, other elements, and sulfur dioxide; therefore, the presently used screening method for symptoms only due to arsenic is not appropriate.

Solving applied mathematical problems with Matlab

CERN Document Server

Xue, Dingyu

2008-01-01

Computer Mathematics Language-An Overview. Fundamentals of MATLAB Programming. Calculus Problems. MATLAB Computations of Linear Algebra Problems. Integral Transforms and Complex Variable Functions. Solutions to Nonlinear Equations and Optimization Problems. MATLAB Solutions to Differential Equation Problems. Solving Interpolations and Approximations Problems. Solving Probability and Mathematical Statistics Problems. Nontraditional Solution Methods for Mathematical Problems.

Sturm--Liouville eigenvalue problem

International Nuclear Information System (INIS)

Bailey, P.B.

1977-01-01

The viewpoint is taken that Sturn--Liouville problem is specified and the problem of computing one or more of the eigenvalues and possibly the corresponding eigenfunctions is presented for solution. The procedure follows the construction of a computer code, although such a code is not constructed, intended to solve Sturn--Liouville eigenvalue problems whether singular or nonsingular

Inverse problems of geophysics

International Nuclear Information System (INIS)

Yanovskaya, T.B.

2003-07-01

This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

Managing Classroom Problems.

Science.gov (United States)

Long, James D.

Schools need to meet unique problems through the development of special classroom management techniques. Factors which contribute to classroom problems include lack of supervision at home, broken homes, economic deprivation, and a desire for peer attention. The educational atmosphere should encourage creativity for both the student and the…

Numerical problems in physics

CERN Document Server

Singh, Devraj

2015-01-01

Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

Combinatorial problems and exercises

CERN Document Server

Lovász, László

2007-01-01

The main purpose of this book is to provide help in learning existing techniques in combinatorics. The most effective way of learning such techniques is to solve exercises and problems. This book presents all the material in the form of problems and series of problems (apart from some general comments at the beginning of each chapter). In the second part, a hint is given for each exercise, which contains the main idea necessary for the solution, but allows the reader to practice the techniques by completing the proof. In the third part, a full solution is provided for each problem. This book w

Problem Gambling Among Ontario Students: Associations with Substance Abuse, Mental Health Problems, Suicide Attempts, and Delinquent Behaviours.

Science.gov (United States)

Cook, Steven; Turner, Nigel E; Ballon, Bruce; Paglia-Boak, Angela; Murray, Robert; Adlaf, Edward M; Ilie, Gabriela; den Dunnen, Wendy; Mann, Robert E

2015-12-01

This paper describes gambling problems among Ontario students in 2009 and examines the relationship between gambling problems and substance use problems, mental health problem indicators, and delinquent behaviors. Data were derived from the Ontario Student Drug Use and Health Survey of Ontario students in grades 7-12. Gambling problems were measured as 2 or more of 6 indicators of problem gambling. In total 2.8% of the students surveyed endorsed two or more of the problem gambling items. The odds of problem gamblers reporting mental distress was 4.2 times higher than the rest of the sample and the odds of problem gamblers reporting a suicide attempt were 17.8 times greater than the rest of the sample. In addition compared to the rest of the students, delinquent behaviors were also more common among problem gamblers, including theft (OR = 14.5), selling marijuana (OR = 19.6), gang fights (OR = 11.3) and carrying a handgun (OR = 11.2). In a multivariate analysis, substance-use problems, mental health problems, and the participation in a variety of delinquent behaviors remained significantly associated with youth problem gambling behavior. Students who report problem gambling behaviors show increased substance abuse, mental health, and delinquency/criminal problems that are similar to those seen among adult problem gamblers. The association between these problems suggests that these problems could be addressed in a unified manner.

Unrecognised ventriculitis/meningitis presenting as hydrocephalus in infancy.

Science.gov (United States)

Udani, Vrajesh; Udani, Soonu; Merani, Rohan; Bavdekar, Manisha

2003-09-01

Infantile hydrocephalus due to unrecognized neonatal-onset meningitis/ventriculitis, was studied retrospectively using 1991-1998 chart review. Seventy two patients with hydrocephalus were reviewed. Thirteen infants had hydrocephalus associated with active meningitis/ventriculitis which had remained unrecognized. Active meningitis/ventriculitis was confirmed by the finding of an abnormal lumbar and ventricular CSF with or without positive culture. All had perinatal risk factors and 10/13 had been given antibiotics in the postnatal period. 6/13 infants appeared to be well. The most common presentation was increasing head size. All lumbar and ventricular CSFs were abnormal and 10/13 had positive cultures as well. Imaging revealed hydrocephalus in all. The infants were treated with antibiotics for a mean of 32.8 days before VP shunting. 7/11 were severely disabled. Unrecognized active meningitis/ventriculitis is an important cause of infantile hydrocephalus.

Polyhedral combinatorics of the cardinality constrained quadratic knapsack problem and the quadratic selective travelling salesman problem

DEFF Research Database (Denmark)

Mak, Vicky; Thomadsen, Tommy

2006-01-01

This paper considers the cardinality constrained quadratic knapsack problem (QKP) and the quadratic selective travelling salesman problem (QSTSP). The QKP is a generalization of the knapsack problem and the QSTSP is a generalization of the travelling salesman problem. Thus, both problems are NP...

Age differences in everyday problem-solving effectiveness: older adults select more effective strategies for interpersonal problems.

Science.gov (United States)

Blanchard-Fields, Fredda; Mienaltowski, Andrew; Seay, Renee Baldi

2007-01-01

Using the Everyday Problem Solving Inventory of Cornelius and Caspi, we examined differences in problem-solving strategy endorsement and effectiveness in two domains of everyday functioning (instrumental or interpersonal, and a mixture of the two domains) and for four strategies (avoidance-denial, passive dependence, planful problem solving, and cognitive analysis). Consistent with past research, our research showed that older adults were more problem focused than young adults in their approach to solving instrumental problems, whereas older adults selected more avoidant-denial strategies than young adults when solving interpersonal problems. Overall, older adults were also more effective than young adults when solving everyday problems, in particular for interpersonal problems.

Astronauts' menu problem.

Science.gov (United States)

Lesso, W. G.; Kenyon, E.

1972-01-01

Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.

Problem situations in management activity

OpenAIRE

N.A. DUBINKO

2009-01-01

This article reviews contemporary methodological and theoretical approaches to the problem situations in management activity. Revealed and analyzed the types of problem situations managers dealing with in their activity. Rank correlation of problem situations shows distinctions depending on management work experience. Revealed gender distinctions in the managers' ideas of management problems.

Reading the problem family: post-structuralism and the analysis of social problems.

Science.gov (United States)

Reekie, G

1994-01-01

Post-structuralist theory questions the rational pursuit of an underlying 'truth' that often characterizes social scientific inquiry, proposing instead the simultaneous existence of multiple and often contradictory truths. The problem family can, from this perspective, only be known through the different discourses that produce it. This paper suggests some of the political advantages of developing methods of reading 'problems' related to drugs and alcohol. Without this critical attention to language, we risk perpetuating the ways in which problems are talked about and thought about. Drawing on examples from debates surrounding teenage pregnancy and youth drinking, the paper argues that post-structuralism allows us to analyse the specific ways in which professional discourses write social problems, and hence to own them and to re-write them.

Sleep problems and daytime problem behaviours in children with intellectual disablity

NARCIS (Netherlands)

Didden, H.C.M.; Korzilius, H.P.L.M.; Aperloo, B. van; Overloon, C. van; Vries, M. de

2002-01-01

BACKGROUND: Sleep problems are common among children with intellectual disability (ID). METHOD: The present study assessed the prevalence of severe sleep problems in a sample of children (n=286) with mild to profound ID who lived at home with their parents(s) in the Netherlands. It also

Population Problem In Egypt As One of The Priority Health Problems ...

African Journals Online (AJOL)

In last decades, Egypt had suffered major socioeconomic consequences of population problem. This had resulted from the high levels of birth rates and the steady decline in death rates and so, a widened demographic gap. Management of population problem of Egypt included: Economic development, developing new ...

Investigasi Kemampuan Problem Solving dan Problem Posing Matematis Mahasiswa Via Pendekatan Realistic

OpenAIRE

Afriansyah, Ekasatya Aldila

2016-01-01

Mathematical problem solving and problem posing skill are the mathematical skills that need to be owned by students. By having this skill, students can be more creative in expressing ideas by connecting the knowledge that they held previously. But in reality, there are some students who are lack of problem solving skill; therefore it is really important to improve learning through appropriate approach. Realistic approach had been chosen as the learning theory to be applied in the class. This ...

Iterative methods for tomography problems: implementation to a cross-well tomography problem

Science.gov (United States)

Karadeniz, M. F.; Weber, G. W.

2018-01-01

The velocity distribution between two boreholes is reconstructed by cross-well tomography, which is commonly used in geology. In this paper, iterative methods, Kaczmarz’s algorithm, algebraic reconstruction technique (ART), and simultaneous iterative reconstruction technique (SIRT), are implemented to a specific cross-well tomography problem. Convergence to the solution of these methods and their CPU time for the cross-well tomography problem are compared. Furthermore, these three methods for this problem are compared for different tolerance values.

High prevalence of autoimmune urticaria in children with chronic urticaria

DEFF Research Database (Denmark)

Brunetti, Luigia; Francavilla, Ruggiero; Miniello, Vito L

2004-01-01

The etiology of chronic urticaria (CU) in childhood often remains unrecognized. Recently, in adults it has been shown that approximately 40% of patients with CU have autoimmune urticaria (AU); however, no data are available in children.......The etiology of chronic urticaria (CU) in childhood often remains unrecognized. Recently, in adults it has been shown that approximately 40% of patients with CU have autoimmune urticaria (AU); however, no data are available in children....

A taxonomy of inductive problems.

Science.gov (United States)

Kemp, Charles; Jern, Alan

2014-02-01

Inductive inferences about objects, features, categories, and relations have been studied for many years, but there are few attempts to chart the range of inductive problems that humans are able to solve. We present a taxonomy of inductive problems that helps to clarify the relationships between familiar inductive problems such as generalization, categorization, and identification, and that introduces new inductive problems for psychological investigation. Our taxonomy is founded on the idea that semantic knowledge is organized into systems of objects, features, categories, and relations, and we attempt to characterize all of the inductive problems that can arise when these systems are partially observed. Recent studies have begun to address some of the new problems in our taxonomy, and future work should aim to develop unified theories of inductive reasoning that explain how people solve all of the problems in the taxonomy.

Assessing student written problem solutions: A problem-solving rubric with application to introductory physics

Directory of Open Access Journals (Sweden)

Jennifer L. Docktor

2016-05-01

Full Text Available Problem solving is a complex process valuable in everyday life and crucial for learning in the STEM fields. To support the development of problem-solving skills it is important for researchers and curriculum developers to have practical tools that can measure the difference between novice and expert problem-solving performance in authentic classroom work. It is also useful if such tools can be employed by instructors to guide their pedagogy. We describe the design, development, and testing of a simple rubric to assess written solutions to problems given in undergraduate introductory physics courses. In particular, we present evidence for the validity, reliability, and utility of the instrument. The rubric identifies five general problem-solving processes and defines the criteria to attain a score in each: organizing problem information into a Useful Description, selecting appropriate principles (Physics Approach, applying those principles to the specific conditions in the problem (Specific Application of Physics, using Mathematical Procedures appropriately, and displaying evidence of an organized reasoning pattern (Logical Progression.

Problem Solving and Learning

Science.gov (United States)

Singh, Chandralekha

2009-07-01

One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited capacity of short term memory makes the cognitive load high during problem solving tasks, leaving few cognitive resources available for meta-cognition. The abstract nature of the laws of physics and the chain of reasoning required to draw meaningful inferences makes these issues critical. In order to help students, it is crucial to consider the difficulty of a problem from the perspective of students. We are developing and evaluating interactive problem-solving tutorials to help students in the introductory physics courses learn effective problem-solving strategies while solidifying physics concepts. The self-paced tutorials can provide guidance and support for a variety of problem solving techniques, and opportunity for knowledge and skill acquisition.

The Guderley problem revisited

International Nuclear Information System (INIS)

Ramsey, Scott D.; Kamm, James R.; Bolstad, John H.

2009-01-01

The self-similar converging-diverging shock wave problem introduced by Guderley in 1942 has been the source of numerous investigations since its publication. In this paper, we review the simplifications and group invariance properties that lead to a self-similar formulation of this problem from the compressible flow equations for a polytropic gas. The complete solution to the self-similar problem reduces to two coupled nonlinear eigenvalue problems: the eigenvalue of the first is the so-called similarity exponent for the converging flow, and that of the second is a trajectory multiplier for the diverging regime. We provide a clear exposition concerning the reflected shock configuration. Additionally, we introduce a new approximation for the similarity exponent, which we compare with other estimates and numerically computed values. Lastly, we use the Guderley problem as the basis of a quantitative verification analysis of a cell-centered, finite volume, Eulerian compressible flow algorithm.

Junior High School Students’ Perception about Simple Environmental Problem as an Impact of Problem based Learning

Science.gov (United States)

Tapilouw, M. C.; Firman, H.; Redjeki, S.; Chandra, D. T.

2017-09-01

Environmental problem is a real problem that occur in student’s daily life. Junior high school students’ perception about environmental problem is interesting to be investigated. The major aim of this study is to explore junior high school students’ perception about environmental problems around them and ways to solve the problem. The subject of this study is 69 Junior High School Students from two Junior High School in Bandung. This study use two open ended question. The core of first question is environmental problem around them (near school or house). The core of second question is the way to prevent or to solve the problem. These two question are as an impact of problem based learning in science learning. There are two major findings in this study. The first finding, based on most students’ perception, plastic waste cause an environmental problem. The second finding, environmental awareness can be a solution to prevent environmental pollution. The third finding, most student can classify environmental pollution into land, water and air pollution. We can conclude that Junior High School Students see the environmental problem as a phenomenon and teacher can explore environmental problem to guide the way of preventing and resolving environmental problem.

Shielding benchmark problems, (2)

International Nuclear Information System (INIS)

Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Shin, Kazuo; Tada, Keiko.

1980-02-01

Shielding benchmark problems prepared by Working Group of Assessment of Shielding Experiments in the Research Committee on Shielding Design in the Atomic Energy Society of Japan were compiled by Shielding Laboratory in Japan Atomic Energy Research Institute. Fourteen shielding benchmark problems are presented newly in addition to twenty-one problems proposed already, for evaluating the calculational algorithm and accuracy of computer codes based on discrete ordinates method and Monte Carlo method and for evaluating the nuclear data used in codes. The present benchmark problems are principally for investigating the backscattering and the streaming of neutrons and gamma rays in two- and three-dimensional configurations. (author)

The effectiveness of problem-based learning on students’ problem solving ability in vector analysis course

Science.gov (United States)

Mushlihuddin, R.; Nurafifah; Irvan

2018-01-01

The student’s low ability in mathematics problem solving proved to the less effective of a learning process in the classroom. Effective learning was a learning that affects student’s math skills, one of which is problem-solving abilities. Problem-solving capability consisted of several stages: understanding the problem, planning the settlement, solving the problem as planned, re-examining the procedure and the outcome. The purpose of this research was to know: (1) was there any influence of PBL model in improving ability Problem solving of student math in a subject of vector analysis?; (2) was the PBL model effective in improving students’ mathematical problem-solving skills in vector analysis courses? This research was a quasi-experiment research. The data analysis techniques performed from the test stages of data description, a prerequisite test is the normality test, and hypothesis test using the ANCOVA test and Gain test. The results showed that: (1) there was an influence of PBL model in improving students’ math problem-solving abilities in vector analysis courses; (2) the PBL model was effective in improving students’ problem-solving skills in vector analysis courses with a medium category.

Pelvic floor muscle problems mediate sexual problems in young adult rape victims.

Science.gov (United States)

Postma, Riemke; Bicanic, Iva; van der Vaart, Huub; Laan, Ellen

2013-08-01

Prior studies have addressed sexual abuse and sexual function in adult women. No studies have focused on the effect of adolescence rape on sexual functioning. To investigate the effect of rape on sexual problems and on pelvic floor problems, as well as the mediating role of pelvic floor problems on sexual problems, in a homogenous group of victims of adolescence rape without a history of childhood sexual, physical, and/or emotional abuse. Sexual functioning and pelvic floor functioning were assessed using self-report questionnaires. In this cross-sectional study, a group of 89 young women aged 18-25 years who were victimized by rape in adolescence was compared with a group of 114 nonvictimized controls. The rape victims were treated for posttraumatic stress disorder (PTSD) 3 years prior to participation in the study. Three years posttreatment, rape victims were 2.4 times more likely to have a sexual dysfunction (lubrication problems and pain) and 2.7 times more likely to have pelvic floor dysfunction (symptoms of provoked vulvodynia, general stress, lower urinary tract, and irritable bowel syndrome) than nonvictimized controls. The relationship between rape and sexual problems was partially mediated by the presence of pelvic floor problems. Rape victims and controls did not differ with regard to sexual activities. Rape victims suffer significantly more from sexual dysfunction and pelvic floor dysfunction when compared with nontraumatized controls, despite the provision of treatment for PTSD. Possibly, physical manifestations of PTSD have been left unaddressed in treatment. Future treatment protocols should consider incorporating (physical or psychological) treatment strategies for sexual dysfunction and/or pelvic floor dysfunction into trauma exposure treatments. © 2013 International Society for Sexual Medicine.

The pear thrips problem

Science.gov (United States)

Bruce L. Parker

1991-01-01

As entomologists, we sometimes like to think of an insect pest problem as simply a problem with an insect and its host. Our jobs would be much easier if that were the case, but of course, it is never that simple. There are many other factors besides the insect, and each one must be fully considered to understand the problem and develop effective management solutions....

Pre-Service Class Teacher' Ability in Solving Mathematical Problems and Skills in Solving Daily Problems

Science.gov (United States)

Aljaberi, Nahil M.; Gheith, Eman

2016-01-01

This study aims to investigate the ability of pre-service class teacher at University of Petrain solving mathematical problems using Polya's Techniques, their level of problem solving skills in daily-life issues. The study also investigates the correlation between their ability to solve mathematical problems and their level of problem solving…

When problem size matters: differential effects of brain stimulation on arithmetic problem solving and neural oscillations.

Directory of Open Access Journals (Sweden)

Bruno Rütsche

Full Text Available The problem size effect is a well-established finding in arithmetic problem solving and is characterized by worse performance in problems with larger compared to smaller operand size. Solving small and large arithmetic problems has also been shown to involve different cognitive processes and distinct electroencephalography (EEG oscillations over the left posterior parietal cortex (LPPC. In this study, we aimed to provide further evidence for these dissociations by using transcranial direct current stimulation (tDCS. Participants underwent anodal (30min, 1.5 mA, LPPC and sham tDCS. After the stimulation, we recorded their neural activity using EEG while the participants solved small and large arithmetic problems. We found that the tDCS effects on performance and oscillatory activity critically depended on the problem size. While anodal tDCS improved response latencies in large arithmetic problems, it decreased solution rates in small arithmetic problems. Likewise, the lower-alpha desynchronization in large problems increased, whereas the theta synchronization in small problems decreased. These findings reveal that the LPPC is differentially involved in solving small and large arithmetic problems and demonstrate that the effects of brain stimulation strikingly differ depending on the involved neuro-cognitive processes.

About an Optimal Visiting Problem

Energy Technology Data Exchange (ETDEWEB)

Bagagiolo, Fabio, E-mail: bagagiol@science.unitn.it; Benetton, Michela [Unversita di Trento, Dipartimento di Matematica (Italy)

2012-02-15

In this paper we are concerned with the optimal control problem consisting in minimizing the time for reaching (visiting) a fixed number of target sets, in particular more than one target. Such a problem is of course reminiscent of the famous 'Traveling Salesman Problem' and brings all its computational difficulties. Our aim is to apply the dynamic programming technique in order to characterize the value function of the problem as the unique viscosity solution of a suitable Hamilton-Jacobi equation. We introduce some 'external' variables, one per target, which keep in memory whether the corresponding target is already visited or not, and we transform the visiting problem in a suitable Mayer problem. This fact allows us to overcome the lacking of the Dynamic Programming Principle for the originary problem. The external variables evolve with a hysteresis law and the Hamilton-Jacobi equation turns out to be discontinuous.

Goals and everyday problem solving: examining the link between age-related goals and problem-solving strategy use.

Science.gov (United States)

Hoppmann, Christiane A; Coats, Abby Heckman; Blanchard-Fields, Fredda

2008-07-01

Qualitative interviews on family and financial problems from 332 adolescents, young, middle-aged, and older adults, demonstrated that developmentally relevant goals predicted problem-solving strategy use over and above problem domain. Four focal goals concerned autonomy, generativity, maintaining good relationships with others, and changing another person. We examined both self- and other-focused problem-solving strategies. Autonomy goals were associated with self-focused instrumental problem solving and generative goals were related to other-focused instrumental problem solving in family and financial problems. Goals of changing another person were related to other-focused instrumental problem solving in the family domain only. The match between goals and strategies, an indicator of problem-solving adaptiveness, showed that young individuals displayed the greatest match between autonomy goals and self-focused problem solving, whereas older adults showed a greater match between generative goals and other-focused problem solving. Findings speak to the importance of considering goals in investigations of age-related differences in everyday problem solving.

IDEAL Problem Solving dalam Pembelajaran Matematika

Directory of Open Access Journals (Sweden)

Eny Susiana

2012-01-01

Full Text Available Most educators agree that problem solving is among the most meaningful and importantkinds of learning and thingking. That is, the central focus of learning and instructionshould be learning to solve problems. There are several warrants supporting that claims.They are authenticity, relevance, problem solving engages deeper learning angtherefore enhances meaning making, and constructed to represent problems (problemsolving is more meaningful. It is the reason why we must provide teaching and learningto make student’s problem solving skill in progress. There are many informationprocessingmodels of problem solving, such as simplified model of the problem-solvingprocess by Gicks, Polya’s problem solving process etc. One of them is IDEAL problemsolving. Each letter of IDEAL is stand for an aspect of thinking that is important forproblem solving. IDEAL is identify problem, Define Goal, Explore possible strategies,Anticipate outcme and Act, and Look back and learn. Using peer interaction andquestion prompt in small group in IDEAL problem solving teaching and Learning canimprove problem solving skill.Kata kunci: IDEAL Problem Solving, Interaksi Sebaya, Pertanyaan Penuntun, KelompokKecil.

Radon: A health problem and a communication problem

International Nuclear Information System (INIS)

Johnson, R.H.

1992-01-01

The US Environmental Protection Agency (USEPA) is making great efforts to alert the American public to the potential health risks of radon in homes. The news media have widely publicized radon as a problem; state and local governments are responding to public alarms; and hundreds of radon open-quotes expertsclose quotes are now offering radon detection and mitigation services. Apparently, USEPA's communication program is working, and the public is becoming increasingly concerned with radon. But are they concerned with radon as a open-quotes healthclose quotes problem in the way USEPA intended? The answer is yes, partly. More and more, however, the concerns are about home resale values. Many homebuyers are now deciding whether to buy on the basis of a single radon screening measurement, comparing it with USEPA's action guide of 4 pCi L -1 . They often conclude that 3.9 is OK, but 4.1 is not. Here is where the communication problems begin. The public largely misunderstands the significance of USEPA's guidelines and the meaning of screening measurements. Seldom does anyone inquire about the quality of the measurements, or the results of USEPA performance testing? Who asks about the uncertainty of lifetime exposure assessments based on a 1-hour, 1-day, 3-day, or even 30-day measurement? Who asks about the uncertainty of USEPA's risk estimates? Fortunately, an increasing number of radiation protection professions are asking such questions. They find that USEPA's risk projections are based on many assumptions which warrant further evaluation, particularly with regard to the combined risks of radon and cigarette-smoking. This is the next communication problem. What are these radiation professions doing to understand the bases for radon health-risk projections? Who is willing to communicate a balanced perspective to the public? Who is willing to communicate the uncertainty and conservatism in radon measurements and risk estimates?

Using Problem-Based Learning in Accounting

Science.gov (United States)

Hansen, James D.

2006-01-01

In this article, the author describes the process of writing a problem-based learning (PBL) problem and shows how a typical end-of-chapter accounting problem can be converted to a PBL problem. PBL uses complex, real-world problems to motivate students to identify and research the concepts and principles they need to know to solve these problems.…

GREECE--SELECTED PROBLEMS.

Science.gov (United States)

MARTONFFY, ANDREA PONTECORVO; AND OTHERS

A CURRICULUM GUIDE IS PRESENTED FOR A 10-WEEK STUDY OF ANCIENT GREEK CIVILIZATION AT THE 10TH-GRADE LEVEL. TEACHING MATERIALS FOR THE UNIT INCLUDE (1) PRIMARY AND SECONDARY SOURCES DEALING WITH THE PERIOD FROM THE BRONZE AGE THROUGH THE HELLENISTIC PERIOD, (2) GEOGRAPHY PROBLEMS, AND (3) CULTURAL MODEL PROBLEM EXERCISES. THOSE CONCEPTS WITH WHICH…

How to solve mathematical problems

CERN Document Server

Wickelgren, Wayne A

1995-01-01

Seven problem-solving techniques include inference, classification of action sequences, subgoals, contradiction, working backward, relations between problems, and mathematical representation. Also, problems from mathematics, science, and engineering with complete solutions.

Problem Solving Instruction for Overcoming Students' Difficulties in Stoichiometric Problems

Science.gov (United States)

Shadreck, Mandina; Enunuwe, Ochonogor Chukunoye

2017-01-01

The study sought to find out difficulties encountered by high school chemistry students when solving stoichiometric problems and how these could be overcome by using a problem-solving approach. The study adopted a quasi-experimental design. 485 participants drawn from 8 highs schools in a local education district in Zimbabwe participated in the…

Parentification, Stress, and Problem Behavior of Adolescents who have a Parent with Mental Health Problems.

Science.gov (United States)

Van Loon, Linda M A; Van de Ven, Monique O M; Van Doesum, Karin T M; Hosman, Clemens M H; Witteman, Cilia L M

2017-03-01

When adolescents live with a parent with mental illness, they often partly take over the parental role. Little is known about the consequences of this so-called parentification on the adolescents' internalizing and externalizing problems. This survey study examined this effect cross-sectionally and longitudinally in a sample of 118 adolescents living with a parent suffering from mental health problems. In addition, the study examined a possible indirect effect via perceived stress. Path analyses were used to examine the direct associations between parentification and problem behavior as well as the indirect relations via perceived stress. The results showed that parentification was associated with both internalizing and externalizing problems cross-sectionally, but it predicted only internalizing problems 1 year later. An indirect effect of parentification on adolescent internalizing and externalizing problems via perceived stress was found, albeit only cross-sectionally. These findings imply that parentification can be stressful for adolescents who live with a parent with mental health problems, and that a greater awareness of parentification is needed to prevent adolescents from developing internalizing problems. © 2015 Family Process Institute.

Not your problem? Exploring the relationship between problem formulation and social responsibility

Directory of Open Access Journals (Sweden)

Sveinung Jørgensen

2011-05-01

Full Text Available This article explores the relationship between organizationalproblem formulation and social responsibility. Thepurpose of the article is to illuminate how organizationalproblem formulations (1 determine the manner in whichthe organization attempts to solve the problem and (2involve the ascription of significance to a group of stakeholdersseen as relevant for the organization. This has implicationsfor the degree to which they assume responsibilityfor those stakeholders. We discuss three dimensions ofresponsible decision making – rationality in goal attainment,reverence for ethical norms, and respect for stakeholders.Thereby, we arrive at an understanding of how differentorganizations in the same sector conceive of, andattempt to solve fundamental problems in the sector, aswell as how their assumed responsibility is reflected therein.We present and discuss a case that discusses keysimilarities and differences between two organizations inthe drug sector – a pharmaceutical company that producesmedicine for the treatment of drug addiction and a foundationworking with drug rehabilitation. We illuminatehow the two organizations base their activities on divergentformulations of the drug problem and how this ismanifested in their approach to the problem. We argue that this ultimately translates into differences in the inclusion of various stakeholdersin their problem space, and thereby the degree to which they assumeresponsibility for key stakeholders. This contributes to the corporate socialresponsibility literature by providing an in depth account of how problem formulationsshape organizational activities and determine the practical inclusionof stakeholders’ interests in the decisions and activities of organizations.

Problem-Based Learning and Problem-Solving Tools: Synthesis and Direction for Distributed Education Environments.

Science.gov (United States)

Friedman, Robert S.; Deek, Fadi P.

2002-01-01

Discusses how the design and implementation of problem-solving tools used in programming instruction are complementary with both the theories of problem-based learning (PBL), including constructivism, and the practices of distributed education environments. Examines how combining PBL, Web-based distributed education, and a problem-solving…

The stochastic goodwill problem

OpenAIRE

Marinelli, Carlo

2003-01-01

Stochastic control problems related to optimal advertising under uncertainty are considered. In particular, we determine the optimal strategies for the problem of maximizing the utility of goodwill at launch time and minimizing the disutility of a stream of advertising costs that extends until the launch time for some classes of stochastic perturbations of the classical Nerlove-Arrow dynamics. We also consider some generalizations such as problems with constrained budget and with discretionar...

Continuous quality control of the blood sampling procedure using a structured observation scheme

OpenAIRE

Lindberg Seemann, Tine; Nybo, Mads

2016-01-01

INTRODUCTION: An observational study was conducted using a structured observation scheme to assess compliance with the local phlebotomy guideline, to identify necessary focus items, and to investigate whether adherence to the phlebotomy guideline improved.MATERIALS AND METHODS: The questionnaire from the EFLM Working Group for the Preanalytical Phase was adapted to local procedures. A pilot study of three months duration was conducted. Based on this, corrective actions were implemented and a ...

Problem Based Learning

DEFF Research Database (Denmark)

de Graaff, Erik; Guerra, Aida

, the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

Deviation Management: Key Management Subsystem Driver of Knowledge-Based Continuous Improvement in the Henry Ford Production System.

Science.gov (United States)

Zarbo, Richard J; Copeland, Jacqueline R; Varney, Ruan C

2017-10-01

To develop a business subsystem fulfilling International Organization for Standardization 15189 nonconformance management regulatory standard, facilitating employee engagement in problem identification and resolution to effect quality improvement and risk mitigation. From 2012 to 2016, the integrated laboratories of the Henry Ford Health System used a quality technical team to develop and improve a management subsystem designed to identify, track, trend, and summarize nonconformances based on frequency, risk, and root cause for elimination at the level of the work. Programmatic improvements and training resulted in markedly increased documentation culminating in 71,641 deviations in 2016 classified by a taxonomy of 281 defect types into preanalytic (74.8%), analytic (23.6%), and postanalytic (1.6%) testing phases. The top 10 deviations accounted for 55,843 (78%) of the total. Deviation management is a key subsystem of managers' standard work whereby knowledge of nonconformities assists in directing corrective actions and continuous improvements that promote consistent execution and higher levels of performance. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Anabolic steroid-induced cardiomyopathy underlying acute liver failure in a young bodybuilder.

Science.gov (United States)

Bispo, Miguel; Valente, Ana; Maldonado, Rosário; Palma, Rui; Glória, Helena; Nóbrega, João; Alexandrino, Paula

2009-06-21

Heart failure may lead to subclinical circulatory disturbances and remain an unrecognized cause of ischemic liver injury. We present the case of a previously healthy 40-year-old bodybuilder, referred to our Intensive-Care Unit of Hepatology for treatment of severe acute liver failure, with the suspicion of toxic hepatitis associated with anabolic steroid abuse. Despite the absence of symptoms and signs of congestive heart failure at admission, an anabolic steroid-induced dilated cardiomyopathy with a large thrombus in both ventricles was found to be the underlying cause of the liver injury. Treatment for the initially unrecognized heart failure rapidly restored liver function to normal. To our knowledge, this is the first reported case of severe acute liver failure due to an unrecognized anabolic steroid-induced cardiomyopathy. Awareness of this unique presentation will allow for prompt treatment of this potentially fatal cause of liver failure.

Common Sleep Problems (For Teens)

Science.gov (United States)

... Safe Videos for Educators Search English Español Common Sleep Problems KidsHealth / For Teens / Common Sleep Problems What's ... have emotional problems, like depression. What Happens During Sleep? You don't notice it, of course, but ...

JIT-transportation problem and its algorithm

Science.gov (United States)

Bai, Guozhong; Gan, Xiao-Xiong

2011-12-01

This article introduces the (just-in-time) JIT-transportation problem, which requires that all demanded goods be shipped to their destinations on schedule, at a zero or minimal destination-storage cost. The JIT-transportation problem is a special goal programming problem with discrete constraints. This article provides a mathematical model for such a transportation problem and introduces the JIT solution, the deviation solution, the JIT deviation, etc. By introducing the B(λ)-problem, this article establishes the equivalence between the optimal solutions of the B(λ)-problem and the optimal solutions of the JIT-transportation problem, and then provides an algorithm for the JIT-transportation problems. This algorithm is proven mathematically and is also illustrated by an example.

Perturbed asymptotically linear problems

OpenAIRE

Bartolo, R.; Candela, A. M.; Salvatore, A.

2012-01-01

The aim of this paper is investigating the existence of solutions of some semilinear elliptic problems on open bounded domains when the nonlinearity is subcritical and asymptotically linear at infinity and there is a perturbation term which is just continuous. Also in the case when the problem has not a variational structure, suitable procedures and estimates allow us to prove that the number of distinct crtitical levels of the functional associated to the unperturbed problem is "stable" unde...

Students’ difficulties in probabilistic problem-solving

Science.gov (United States)

Arum, D. P.; Kusmayadi, T. A.; Pramudya, I.

2018-03-01

There are many errors can be identified when students solving mathematics problems, particularly in solving the probabilistic problem. This present study aims to investigate students’ difficulties in solving the probabilistic problem. It focuses on analyzing and describing students errors during solving the problem. This research used the qualitative method with case study strategy. The subjects in this research involve ten students of 9th grade that were selected by purposive sampling. Data in this research involve students’ probabilistic problem-solving result and recorded interview regarding students’ difficulties in solving the problem. Those data were analyzed descriptively using Miles and Huberman steps. The results show that students have difficulties in solving the probabilistic problem and can be divided into three categories. First difficulties relate to students’ difficulties in understanding the probabilistic problem. Second, students’ difficulties in choosing and using appropriate strategies for solving the problem. Third, students’ difficulties with the computational process in solving the problem. Based on the result seems that students still have difficulties in solving the probabilistic problem. It means that students have not able to use their knowledge and ability for responding probabilistic problem yet. Therefore, it is important for mathematics teachers to plan probabilistic learning which could optimize students probabilistic thinking ability.

Could HPS Improve Problem-Solving?

Science.gov (United States)

Coelho, Ricardo Lopes

2013-05-01

It is generally accepted nowadays that History and Philosophy of Science (HPS) is useful in understanding scientific concepts, theories and even some experiments. Problem-solving strategies are a significant topic, since students' careers depend on their skill to solve problems. These are the reasons for addressing the question of whether problem solving could be improved by means of HPS. Three typical problems in introductory courses of mechanics—the inclined plane, the simple pendulum and the Atwood machine—are taken as the object of the present study. The solving strategies of these problems in the eighteenth and nineteenth century constitute the historical component of the study. Its philosophical component stems from the foundations of mechanics research literature. The use of HPS leads us to see those problems in a different way. These different ways can be tested, for which experiments are proposed. The traditional solving strategies for the incline and pendulum problems are adequate for some situations but not in general. The recourse to apparent weights in the Atwood machine problem leads us to a new insight and a solving strategy for composed Atwood machines. Educational implications also concern the development of logical thinking by means of the variety of lines of thought provided by HPS.

Teaching problem solving: Don't forget the problem solver(s)

Science.gov (United States)

Ranade, Saidas M.; Corrales, Angela

2013-05-01

The importance of intrapersonal and interpersonal intelligences has long been known but educators have debated whether to and how to incorporate those topics in an already crowded engineering curriculum. In 2010, the authors used the classroom as a laboratory to observe the usefulness of including selected case studies and exercises from the fields of neurology, artificial intelligence, cognitive sciences and social psychology in a new problem-solving course. To further validate their initial findings, in 2012, the authors conducted an online survey of engineering students and engineers. The main conclusion is that engineering students will benefit from learning more about the impact of emotions, culture, diversity and cognitive biases when solving problems. Specifically, the work shows that an augmented problem-solving curriculum needs to include lessons on labelling emotions and cognitive biases, 'evidence-based' data on the importance of culture and diversity and additional practice on estimating conditional probability.

The Steiner tree problem

CERN Document Server

Hwang, FK; Winter, P

1992-01-01

The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

Assessing Student Written Problem Solutions: A Problem-Solving Rubric with Application to Introductory Physics

Science.gov (United States)

Docktor, Jennifer L.; Dornfeld, Jay; Frodermann, Evan; Heller, Kenneth; Hsu, Leonardo; Jackson, Koblar Alan; Mason, Andrew; Ryan, Qing X.; Yang, Jie

2016-01-01

Problem solving is a complex process valuable in everyday life and crucial for learning in the STEM fields. To support the development of problem-solving skills it is important for researchers and curriculum developers to have practical tools that can measure the difference between novice and expert problem-solving performance in authentic…

Obstacle mean-field game problem

KAUST Repository

Gomes, Diogo A.; Patrizi, Stefania

2015-01-01

In this paper, we introduce and study a first-order mean-field game obstacle problem. We examine the case of local dependence on the measure under assumptions that include both the logarithmic case and power-like nonlinearities. Since the obstacle operator is not differentiable, the equations for first-order mean field game problems have to be discussed carefully. Hence, we begin by considering a penalized problem. We prove this problem admits a unique solution satisfying uniform bounds. These bounds serve to pass to the limit in the penalized problem and to characterize the limiting equations. Finally, we prove uniqueness of solutions. © European Mathematical Society 2015.

Side Effects: Sleep Problems

Science.gov (United States)

Sleep problems are a common side effect during cancer treatment. Learn how a polysomnogram can assess sleep problems. Learn about the benefits of managing sleep disorders in men and women with cancer.

Mekh-mat entrance examinations problems

CERN Document Server

Vardi, I

2000-01-01

This paper provides a complete solution set to 25 ``killer problems'' given to Jewish candidates to the Mekh--mat at Moscow State University during the 1970's and 1980's. Typically, the problems are at the mathematical olympiad level and some feature interesting theorems. However, a number of the problems are flawed, or even completely wrong. The paper therefore includes an evaluation of the problems in the style of a referee report.

Secretary Problems: Weights and Discounts

OpenAIRE

Babaioff, M.; Dinitz, M.; Gupta, A.; Immorlica, Nicole Simone; Talwar, K.

2009-01-01

textabstractThe classical secretary problem studies the problem of selecting online an element (a “secretary”) with maximum value in a randomly ordered sequence. The difficulty lies in the fact that an element must be either selected or discarded upon its arrival, and this decision is irrevocable. Constant-competitive algorithms are known for the classical secretary problems and several variants. We study the following two extensions of the secretary problem: In the discounted secretary probl...

Solar neutrino problem

Energy Technology Data Exchange (ETDEWEB)

Faulkner, D J [Australian National Univ., Canberra. Mount Stromlo and Siding Spring Observatories

1975-10-01

This paper reviews several recent attempts to solve the problem in terms of modified solar interior models. Some of these have removed the count rate discrepancy, but have violated other observational data for the sun. One successfully accounts for the Davis results at the expense of introducing an ad hoc correction with no current physical explanation. An introductory description of the problem is given.

Schiffer's Conjecture, Interior Transmission Eigenvalues and Invisibility Cloaking: Singular Problem vs. Nonsingular Problem

OpenAIRE

Liu, Hongyu

2012-01-01

In this note, we present some interesting observations on the Schiffer's conjecture, interior transmission eigenvalue problem and their connections to singular and nonsingular invisibility cloaking problems of acoustic waves.

Problems on Divisibility of Binomial Coefficients

Science.gov (United States)

Osler, Thomas J.; Smoak, James

2004-01-01

Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…

Sialorrhea: a review of a vexing, often unrecognized sign of oropharyngeal and esophageal disease.

Science.gov (United States)

Boyce, H Worth; Bakheet, Michael R

2005-02-01

Saliva is produced by the major salivary glands (parotid, submandibular, and sublingual), as well as several smaller glands. Salivary flow can be altered by multiple entities. There is much written regarding xerostomia ("dry mouth"), the condition related to inhibited or decreased salivary flow. This condition is widely recognized in certain systemic diseases, particularly Sjögren syndrome, diabetes mellitus, after anticholinergic, antihistamine, and decongestant medications, as well as states of enhanced sympathetic drive, such as anxiety or emotional disturbances and various other psychosocial conditions. On the other hand, sialorrhea or ptyalism, the condition of increased salivary flow, is rarely discussed in the clinical literature. Sialorrhea can occur with various neurologic disorders, infections, the secretory phase of the menstrual cycle, heavy metal poisoning, Wilson disease, Angelman syndrome, as well as a relatively unknown condition called idiopathic paroxysmal sialorrhea. Normal salivation may be altered by drugs (such as clozapine, risperidone, nitrazepam, lithium, and bethanecol) that have a cholinergic effect that induces sialorrhea. This report focuses on sialorrhea as it relates to disorders of the oropharynx and esophagus. The patient typically recognizes a problem with excessive "foamy mucus" but does not understand its origin. Infections and obstruction are the most common oropharyngeal causes. Increased salivary flow occurs as a typically subtle manifestation of gastroesophageal reflux disease. This occurrence is referred to as water brash. Idiopathic achalasia and megaesophagus due to the parasite Trypanosoma cruzi are regularly associated with sialorrhea. Esophageal obstruction (foreign body, cancer, or stricture formation), infection, and nasogastric intubation are the more common conditions associated with the symptomatic sequelae of sialorrhea. Sialorrhea-related respiratory and pulmonary complications are greatest in those with a

Challenging problems in algebra

CERN Document Server

Posamentier, Alfred S

1996-01-01

Over 300 unusual problems, ranging from easy to difficult, involving equations and inequalities, Diophantine equations, number theory, quadratic equations, logarithms, more. Detailed solutions, as well as brief answers, for all problems are provided.

Cognitive Backgrounds of Problem Solving: A Comparison of Open-Ended vs. Closed Mathematics Problems

Science.gov (United States)

Bahar, Abdulkadir; Maker, C. June

2015-01-01

Problem solving has been a core theme in education for several decades. Educators and policy makers agree on the importance of the role of problem solving skills for school and real life success. A primary purpose of this study was to investigate the influence of cognitive abilities on mathematical problem solving performance of elementary…

Creativity for Problem Solvers

DEFF Research Database (Denmark)

Vidal, Rene Victor Valqui

2009-01-01

This paper presents some modern and interdisciplinary concepts about creativity and creative processes specially related to problem solving. Central publications related to the theme are briefly reviewed. Creative tools and approaches suitable to support problem solving are also presented. Finally......, the paper outlines the author’s experiences using creative tools and approaches to: Facilitation of problem solving processes, strategy development in organisations, design of optimisation systems for large scale and complex logistic systems, and creative design of software optimisation for complex non...

Processes involved in solving mathematical problems

Science.gov (United States)

Shahrill, Masitah; Putri, Ratu Ilma Indra; Zulkardi, Prahmana, Rully Charitas Indra

2018-04-01

This study examines one of the instructional practices features utilized within the Year 8 mathematics lessons in Brunei Darussalam. The codes from the TIMSS 1999 Video Study were applied and strictly followed, and from the 183 mathematics problems recorded, there were 95 problems with a solution presented during the public segments of the video-recorded lesson sequences of the four sampled teachers. The analyses involved firstly, identifying the processes related to mathematical problem statements, and secondly, examining the different processes used in solving the mathematical problems for each problem publicly completed during the lessons. The findings revealed that for three of the teachers, their problem statements coded as `using procedures' ranged from 64% to 83%, while the remaining teacher had 40% of his problem statements coded as `making connections.' The processes used when solving the problems were mainly `using procedures', and none of the problems were coded as `giving results only'. Furthermore, all four teachers made use of making the relevant connections in solving the problems given to their respective students.

Collaborative problem structuring using MARVEL

NARCIS (Netherlands)

Veldhuis, G.A.; Scheepstal, P.G.M. van; Rouwette, E.A.J.A.; Logtens, T.W.A.

2015-01-01

When faced with wicked and messy problems, practitioners can rely on a variety of problem structuring methods (PSMs). Although previous efforts have been made to combine such methods with simulation, currently, few exist that integrate a simulation capability within problem structuring. Our

Problem Based Game Design

DEFF Research Database (Denmark)

Reng, Lars; Schoenau-Fog, Henrik

2011-01-01

At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various ...... projects and how they learn to analyse, design, and develop for innovation by using it. We will present various cases to exemplify the approach and focus on how the method engages students and aspires for innovation in digital entertainment and games.......At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various...

Abstract Cauchy problems three approaches

CERN Document Server

Melnikova, Irina V

2001-01-01

Although the theory of well-posed Cauchy problems is reasonably understood, ill-posed problems-involved in a numerous mathematical models in physics, engineering, and finance- can be approached in a variety of ways. Historically, there have been three major strategies for dealing with such problems: semigroup, abstract distribution, and regularization methods. Semigroup and distribution methods restore well-posedness, in a modern weak sense. Regularization methods provide approximate solutions to ill-posed problems. Although these approaches were extensively developed over the last decades by many researchers, nowhere could one find a comprehensive treatment of all three approaches.Abstract Cauchy Problems: Three Approaches provides an innovative, self-contained account of these methods and, furthermore, demonstrates and studies some of the profound connections between them. The authors discuss the application of different methods not only to the Cauchy problem that is not well-posed in the classical sense, b...

Procedure for statistical analysis of one-parameter discrepant experimental data

International Nuclear Information System (INIS)

Badikov, Sergey A.; Chechev, Valery P.

2012-01-01

A new, Mandel–Paule-type procedure for statistical processing of one-parameter discrepant experimental data is described. The procedure enables one to estimate a contribution of unrecognized experimental errors into the total experimental uncertainty as well as to include it in analysis. A definition of discrepant experimental data for an arbitrary number of measurements is introduced as an accompanying result. In the case of negligible unrecognized experimental errors, the procedure simply reduces to the calculation of the weighted average and its internal uncertainty. The procedure was applied to the statistical analysis of half-life experimental data; Mean half-lives for 20 actinides were calculated and results were compared to the ENSDF and DDEP evaluations. On the whole, the calculated half-lives are consistent with the ENSDF and DDEP evaluations. However, the uncertainties calculated in this work essentially exceed the ENSDF and DDEP evaluations for discrepant experimental data. This effect can be explained by adequately taking into account unrecognized experimental errors. - Highlights: ► A new statistical procedure for processing one-parametric discrepant experimental data has been presented. ► Procedure estimates a contribution of unrecognized errors in the total experimental uncertainty. ► Procedure was applied for processing half-life discrepant experimental data. ► Results of the calculations are compared to the ENSDF and DDEP evaluations.

Framework of synchromodal transportation problems

NARCIS (Netherlands)

Juncker, M.A.M. de; Huizing, D.; Vecchyo, M.R.O. del; Phillipson, F.; Sangers, A.

2017-01-01

Problem statements and solution methods in mathematical synchromodal transportation problems depend greatly on a set of model choices for which no rule of thumb exists. In this paper, a framework is introduced with which the model choices in synchromodal transportation problems can be classified,

Framework of Synchromodal Transportation Problems

NARCIS (Netherlands)

Huncker, M.A.M. de; Huizing, D.; Ortega del Vecchyo, M.R.; Phillipson, F.; Sangers, A.

2017-01-01

Problem statements and solution methods in mathematical synchromodal transportation problems depend greatly on a set of model choices for which no rule of thumb exists. In this paper, a framework is introduced with which the model choices in synchromodal transportation problems can be classified,

The uncertain geographic context problem

NARCIS (Netherlands)

Kwan, M.P.

2012-01-01

Any study that examines the effects of area-based attributes on individual behaviors or outcomes faces another fundamental methodological problem besides the modifiable areal unit problem (MAUP). It is the problem that results about these effects can be affected by how contextual units or

Multi-Stage Transportation Problem With Capacity Limit

Directory of Open Access Journals (Sweden)

I. Brezina

2010-06-01

Full Text Available The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algorithms for transportation problem etc. and heuristics approaches (e.g. evolutionary techniques were developed. This article considers Multi-stage transportation problem with capacity limit that reflects limits of transported materials (commodity quantity. Discussed issues are: theoretical base, problem formulation as way as new proposed algorithm for that problem.

Alcoholism: diagnosis, prognosis, epidemiology, and burden of the disease.

Science.gov (United States)

Beresford, Thomas P; Wongngamnit, Narin; Temple, Benjamin A

2014-01-01

To the clinician, alcoholism can appear as an amorphous entity that is confusing with respect to diagnosis, treatment prognosis, and the role of the health professional, despite its high incidence and associated morbidities and mortality when unrecognized or untreated. This chapter focuses on the clinical application of current knowledge, with the aim of being useful to the practitioner in working directly with patients for whom alcoholism may or may not be an already identified problem. It briefly reviews large-scale studies and then focuses on diagnosis and prognosis assessment and decision making. Also considered are current controversies in nomenclature and the chapter ends with an economic perspective with respect to healthcare and cost to society. As the introductory chapter, the goal is to provide a context of the scope of alcoholism and attendant problems for the rest of the chapters. © 2014 Elsevier B.V. All rights reserved.

Should we screen for emotional distress in type 2 diabetes mellitus?

DEFF Research Database (Denmark)

Pouwer, Francois

2009-01-01

Emotional problems such as depression, anxiety and diabetes-specific distress are common in patients with type 2 diabetes mellitus (T2DM) but often remain unrecognized and thus untreated. The present Review focuses on the extent of this problem and discusses whether we should screen for depression......DM have shown that screening for depression does not improve outcomes. On the other hand, collaborative care approaches for depression in patients with type 1 diabetes mellitus (T1DM) or T2DM seem to be effective. Intervention studies for anxiety or diabetes-specific emotional distress are currently...... assessments of emotional well-being in patients with T2DM. However, this recommendation is not based on strong evidence, as the effects of screening (case-finding) on psychological outcomes and diabetes outcomes have not been tested in a randomized controlled study. Results from studies in patients without T2...

The Soccer-Ball Problem

Science.gov (United States)

Hossenfelder, Sabine

2014-07-01

The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

Using standardized patients versus video cases for representing clinical problems in problem-based learning.

Science.gov (United States)

Yoon, Bo Young; Choi, Ikseon; Choi, Seokjin; Kim, Tae-Hee; Roh, Hyerin; Rhee, Byoung Doo; Lee, Jong-Tae

2016-06-01

The quality of problem representation is critical for developing students' problem-solving abilities in problem-based learning (PBL). This study investigates preclinical students' experience with standardized patients (SPs) as a problem representation method compared to using video cases in PBL. A cohort of 99 second-year preclinical students from Inje University College of Medicine (IUCM) responded to a Likert scale questionnaire on their learning experiences after they had experienced both video cases and SPs in PBL. The questionnaire consisted of 14 items with eight subcategories: problem identification, hypothesis generation, motivation, collaborative learning, reflective thinking, authenticity, patient-doctor communication, and attitude toward patients. The results reveal that using SPs led to the preclinical students having significantly positive experiences in boosting patient-doctor communication skills; the perceived authenticity of their clinical situations; development of proper attitudes toward patients; and motivation, reflective thinking, and collaborative learning when compared to using video cases. The SPs also provided more challenges than the video cases during problem identification and hypotheses generation. SPs are more effective than video cases in delivering higher levels of authenticity in clinical problems for PBL. The interaction with SPs engages preclinical students in deeper thinking and discussion; growth of communication skills; development of proper attitudes toward patients; and motivation. Considering the higher cost of SPs compared with video cases, SPs could be used most advantageously during the preclinical period in the IUCM curriculum.

Dimensions of problem based learning

DEFF Research Database (Denmark)

Nielsen, Jørgen Lerche; Andreasen, Lars Birch

2013-01-01

The article contributes to the literature on problem based learning and problem-oriented project work, building on and reflecting the experiences of the authors through decades of work with problem-oriented project pedagogy. The article explores different dimensions of problem based learning such...... and Learning (MIL). We discuss changes in the roles of the teachers as supervisors within this learning environment, and we explore the involvement of students as active participants and co-designers of how course and project activities unfold....

Impact of Prolonged Blood Incubation and Extended Serum Storage at Room Temperature on the Human Serum Metabolome

Directory of Open Access Journals (Sweden)

Beate Kamlage

2018-01-01

Full Text Available Metabolomics is a powerful technology with broad applications in life science that, like other -omics approaches, requires high-quality samples to achieve reliable results and ensure reproducibility. Therefore, along with quality assurance, methods to assess sample quality regarding pre-analytical confounders are urgently needed. In this study, we analyzed the response of the human serum metabolome to pre-analytical variations comprising prolonged blood incubation and extended serum storage at room temperature by using gas chromatography-mass spectrometry (GC-MS and liquid chromatography-tandem mass spectrometry (LC-MS/MS -based metabolomics. We found that the prolonged incubation of blood results in a statistically significant 20% increase and 4% decrease of 225 tested serum metabolites. Extended serum storage affected 21% of the analyzed metabolites (14% increased, 7% decreased. Amino acids and nucleobases showed the highest percentage of changed metabolites in both confounding conditions, whereas lipids were remarkably stable. Interestingly, the amounts of taurine and O-phosphoethanolamine, which have both been discussed as biomarkers for various diseases, were 1.8- and 2.9-fold increased after 6 h of blood incubation. Since we found that both are more stable in ethylenediaminetetraacetic acid (EDTA blood, EDTA plasma should be the preferred metabolomics matrix.

Investigations of blood ammonia analysis: Test matrices, storage, and stability.

Science.gov (United States)

Goldstein, Brittany N; Wesler, Jordan; Nowacki, Amy S; Reineks, Edmunds; Natowicz, Marvin R

2017-06-01

An assessment of blood ammonia concentration is common medical practice in the evaluation of an individual with an unexplained mental status change or coma. The determination of a blood ammonia level is most commonly done using a glutamate dehydrogenase (GLDH)-based assay, although there are many potential sources of artifact and the literature is inconsistent regarding key preanalytic issues. Using a GLDH-based assay, we first investigated matrix effects using three anticoagulants: heparin, EDTA and oxalate. Heparin-anticoagulated plasma was substantially less precise than EDTA- and oxalate-anticoagulated plasma. Oxalate-anticoagulated plasma showed a greater baseline of apparent ammonia than either heparin- or EDTA-derived plasma, presumably due to interferants. We then evaluated the stability of EDTA-anticoagulated plasma for assessment of ammonia when stored at 4°C,-14°C or -70°C. There was a linear increase of ammonia with storage at both 4°C and -14°C. Plasma kept at -70°C for up to three weeks showed no change in measured ammonia relative to the baseline determination. This work clarifies preanalytic conditions for which a precise determination of ammonia can be accomplished using a GLDH-based assay. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Multi-Stage Transportation Problem With Capacity Limit

OpenAIRE

I. Brezina; Z. Čičková; J. Pekár; M. Reiff

2010-01-01

The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algor...

Problems of Turkish Librarianship and Problems for Solution

Directory of Open Access Journals (Sweden)

İrfan Çakın

1993-09-01

Full Text Available Report presented to the Librarianship, Documentation and Archives Committee of the UNESCO Turkish National Commission, identifies environmental factors, the notion of library and librarianship in the society, and the low profile of librarians as main sources of problems. The society still sees the librarian as the protector of books. The value given to the profession is, thus, limited to such a narrow understanding of the profession, which leads to low payment and insufficient resource allocation to the libraries. Main field of activity, that is, the pro\\ision of information is expected from documentation and information centres. Library and information work cannot be separated from each other. The proposals for solution of the problems include improvement of professional education, legal provisions, and reorganiztion of professional organizations.

Assertiveness and problem solving in midwives.

Science.gov (United States)

Yurtsal, Zeliha Burcu; Özdemir, Levent

2015-01-01

Midwifery profession is required to bring solutions to problems and a midwife is expected to be an assertive person and to develop midwifery care. This study was planned to examine the relationship between assertiveness and problem-solving skills of midwives. This cross-sectional study was conducted with 201 midwives between July 2008 and February 2009 in the city center of Sivas. The Rathus Assertiveness Schedule (RAS) and Problem Solving Inventory (PSI) were used to determine the level of assertiveness and problem-solving skills of midwives. Statistical methods were used as mean, standard deviation, percentage, Student's T, ANOVA and Tukey HSD, Kruskal Wallis, Fisher Exact, Pearson Correlation and Chi-square tests and P problem-solving skills training. A statistically significant negative correlation was found between the RAS and PSI scores. The RAS scores decreased while the problem-solving scores increased (r: -0451, P problem solving skills of midwives, and midwives who were assertive solved their problems better than did others. Assertiveness and problem-solving skills training will contribute to the success of the midwifery profession. Midwives able to solve problems, and display assertive behaviors will contribute to the development of midwifery profession.

Dynamical impurity problems

International Nuclear Information System (INIS)

Emery, V.J.; Kivelson, S.A.

1993-01-01

In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class

Dynamical impurity problems

Energy Technology Data Exchange (ETDEWEB)

Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

1993-12-31

In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

School Leaders' Problem Framing: A Sense-Making Approach to Problem-Solving Processes of Beginning School Leaders

Science.gov (United States)

Sleegers, Peter; Wassink, Hartger; van Veen, Klaas; Imants, Jeroen

2009-01-01

In addition to cognitive research on school leaders' problem solving, this study focuses on the situated and personal nature of problem framing by combining insights from cognitive research on problem solving and sense-making theory. The study reports the results of a case study of two school leaders solving problems in their daily context by…

One-dimensional Gromov minimal filling problem

International Nuclear Information System (INIS)

Ivanov, Alexandr O; Tuzhilin, Alexey A

2012-01-01

The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

Highly indefinite multigrid for eigenvalue problems

Energy Technology Data Exchange (ETDEWEB)

Borges, L.; Oliveira, S.

1996-12-31

Eigenvalue problems are extremely important in understanding dynamic processes such as vibrations and control systems. Large scale eigenvalue problems can be very difficult to solve, especially if a large number of eigenvalues and the corresponding eigenvectors need to be computed. For solving this problem a multigrid preconditioned algorithm is presented in {open_quotes}The Davidson Algorithm, preconditioning and misconvergence{close_quotes}. Another approach for solving eigenvalue problems is by developing efficient solutions for highly indefinite problems. In this paper we concentrate on the use of new highly indefinite multigrid algorithms for the eigenvalue problem.

What Is the Problem in Problem-Based Learning in Higher Education Mathematics

Science.gov (United States)

Dahl, Bettina

2018-01-01

Problem and Project-Based Learning (PBL) emphasise collaborate work on problems relevant to society and emphases the relation between theory and practice. PBL fits engineering students as preparation for their future professions but what about mathematics? Mathematics is not just applied mathematics, but it is also a body of abstract knowledge…

Problem children or harassed childhood?

DEFF Research Database (Denmark)

Warming, Hanne

instition as stressed andnoisy, and thus it is the children they try to change (re-socialize) to solve the problems. The paper concludes that the discoruses tend to individualize structural problems with the result that a large group of children are identified as problem children rather than given better...

Solving complex fisheries management problems

DEFF Research Database (Denmark)

Petter Johnsen, Jahn; Eliasen, Søren Qvist

2011-01-01

A crucial issue for the new EU common fisheries policy is how to solve the discard problem. Through a study of the institutional set up and the arrangements for solving the discard problem in Denmark, the Faroe Islands, Iceland and Norway, the article identifies the discard problem as related...

Six problems in frame theory

DEFF Research Database (Denmark)

Christensen, Ole

2014-01-01

We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role.......We discuss various problems in frame theory that have been open for some years. A short discussion of frame theory is also provided, but it only contains the information that is necessary in order to understand the open problems and their role....

Sociological interpretation of social problems

Directory of Open Access Journals (Sweden)

O. V. Katsora

2015-04-01

The article considers such sociological approaches to social problems as social pathology, social disorganization, functional and critical approaches, the approach of value conflict, constructionsite approach and the approach of «labelling». Each approach has its own peculiarities of consideration of social problems, that is related with the historical period in which it arose and settled down, and the views of members of a particular sociological approach to social problems. Also, the article discusses the main advantages and disadvantages of sociological approaches to dealing the social problems.

Brauer type embedding problems

CERN Document Server

Ledet, Arne

2005-01-01

This monograph is concerned with Galois theoretical embedding problems of so-called Brauer type with a focus on 2-groups and on finding explicit criteria for solvability and explicit constructions of the solutions. The advantage of considering Brauer type embedding problems is their comparatively simple condition for solvability in the form of an obstruction in the Brauer group of the ground field. This book presupposes knowledge of classical Galois theory and the attendant algebra. Before considering questions of reducing the embedding problems and reformulating the solvability criteria, the

Customer-centered problem solving.

Science.gov (United States)

Samelson, Q B

1999-11-01

If there is no single best way to attract new customers and retain current customers, there is surely an easy way to lose them: fail to solve the problems that arise in nearly every buyer-supplier relationship, or solve them in an unsatisfactory manner. Yet, all too frequently, companies do just that. Either we deny that a problem exists, we exert all our efforts to pin the blame elsewhere, or we "Band-Aid" the problem instead of fixing it, almost guaranteeing that we will face it again and again.

Problem-Oriented Project Work

DEFF Research Database (Denmark)

Olsen, Poul Bitsch; Pedersen, Nils Kaare

This book is meant to support problem-oriented learning activities. Problem-orientation concerns the reasoning about lack of knowledge, while project work includes the ethnomethods that are practiced when collectives produce scientific knowledge. This book reflects particular methods related...

Math word problems for dummies

CERN Document Server

Sterling, Mary Jane

2008-01-01

Covers percentages, probability, proportions, and moreGet a grip on all types of word problems by applying them to real lifeAre you mystified by math word problems? This easy-to-understand guide shows you how to conquer these tricky questions with a step-by-step plan for finding the right solution each and every time, no matter the kind or level of problem. From learning math lingo and performing operations to calculating formulas and writing equations, you''ll get all the skills you need to succeed!Discover how to: * Translate word problems into plain English* Brush up on basic math skills* Plug in the right operation or formula* Tackle algebraic and geometric problems* Check your answers to see if they work

Problem music and self-harming.

Science.gov (United States)

North, Adrian C; Hargreaves, David J

2006-10-01

Academics and protest groups have claimed that "problem music" (hard rock, hip hop/rap, & punk) causes self-injurious thoughts/behaviors among fans. In this study we investigated whether the relationship is mediated by self-esteem, delinquency, and conservatism; and whether first exposure to problem music preceded self-injurious thoughts. A liking for problem music was associated with four of the five self-injurious measures, although these significant relationships were weakened (into nonsignificance in the case of two self-injurious measures) when the mediating variables were included. Listening to problem music did not precede self-injurious thoughts. Problem music is associated with self-injurious thoughts and behaviors, but this relationship is mediated by other factors and the former does not seem to cause the latter.

Insight Is Not in the Problem: Investigating Insight in Problem Solving across Task Types.

Science.gov (United States)

Webb, Margaret E; Little, Daniel R; Cropper, Simon J

2016-01-01

The feeling of insight in problem solving is typically associated with the sudden realization of a solution that appears obviously correct (Kounios et al., 2006). Salvi et al. (2016) found that a solution accompanied with sudden insight is more likely to be correct than a problem solved through conscious and incremental steps. However, Metcalfe (1986) indicated that participants would often present an inelegant but plausible (wrong) answer as correct with a high feeling of warmth (a subjective measure of closeness to solution). This discrepancy may be due to the use of different tasks or due to different methods in the measurement of insight (i.e., using a binary vs. continuous scale). In three experiments, we investigated both findings, using many different problem tasks (e.g., Compound Remote Associates, so-called classic insight problems, and non-insight problems). Participants rated insight-related affect (feelings of Aha-experience, confidence, surprise, impasse, and pleasure) on continuous scales. As expected we found that, for problems designed to elicit insight, correct solutions elicited higher proportions of reported insight in the solution compared to non-insight solutions; further, correct solutions elicited stronger feelings of insight compared to incorrect solutions.

Solving radwaste problems

International Nuclear Information System (INIS)

Oyen, L.C.

1976-01-01

The combination of regulatory changes and increased waste volume has resulted in design changes in waste processing systems. Problems resulting from waste segregation as a basis for design philosophy are considered, and solutions to the problems are suggested. The importance of operator training, maintenance procedures, good housekeeping, water management, and offsite shipment of solids is discussed. Flowsheets for radioactive waste processing systems for boiling water reactors and pressurized water reactors are included

Problems of Forecast

OpenAIRE

Kucharavy , Dmitry; De Guio , Roland

2005-01-01

International audience; The ability to foresee future technology is a key task of Innovative Design. The paper focuses on the obstacles to reliable prediction of technological evolution for the purpose of Innovative Design. First, a brief analysis of problems for existing forecasting methods is presented. The causes for the complexity of technology prediction are discussed in the context of reduction of the forecast errors. Second, using a contradiction analysis, a set of problems related to ...

Problem solving of student with visual impairment related to mathematical literacy problem

Science.gov (United States)

Pratama, A. R.; Saputro, D. R. S.; Riyadi

2018-04-01

The student with visual impairment, total blind category depends on the sense of touch and hearing in obtaining information. In fact, the two senses can receive information less than 20%. Thus, students with visual impairment of the total blind categories in the learning process must have difficulty, including learning mathematics. This study aims to describe the problem-solving process of the student with visual impairment, total blind category on mathematical literacy issues based on Polya phase. This research using test method similar problems mathematical literacy in PISA and in-depth interviews. The subject of this study was a student with visual impairment, total blind category. Based on the result of the research, problem-solving related to mathematical literacy based on Polya phase is quite good. In the phase of understanding the problem, the student read about twice by brushing the text and assisted with information through hearing three times. The student with visual impairment in problem-solving based on the Polya phase, devising a plan by summoning knowledge and experience gained previously. At the phase of carrying out the plan, students with visual impairment implement the plan in accordance with pre-made. In the looking back phase, students with visual impairment need to check the answers three times but have not been able to find a way.

Effects of worked examples, example-problem, and problem-example pairs on novices’ learning

NARCIS (Netherlands)

Van Gog, Tamara; Kester, Liesbeth; Paas, Fred

2010-01-01

Van Gog, T., Kester, L., & Paas, F. (2011). Effects of worked examples, example-problem, and problem-example pairs on novices’ learning. Contemporary Educational Psychology, 36(3), 212-218. doi:10.1016/j.cedpsych.2010.10.004

On generalized operator quasi-equilibrium problems

Science.gov (United States)

Kum, Sangho; Kim, Won Kyu

2008-09-01

In this paper, we will introduce the generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which generalize the operator equilibrium problem due to Kazmi and Raouf [K.R. Kazmi, A. Raouf, A class of operator equilibrium problems, J. Math. Anal. Appl. 308 (2005) 554-564] into multi-valued and quasi-equilibrium problems. Using a Fan-Browder type fixed point theorem in [S. Park, Foundations of the KKM theory via coincidences of composites of upper semicontinuous maps, J. Korean Math. Soc. 31 (1994) 493-519] and an existence theorem of equilibrium for 1-person game in [X.-P. Ding, W.K. Kim, K.-K. Tan, Equilibria of non-compact generalized games with L*-majorized preferences, J. Math. Anal. Appl. 164 (1992) 508-517] as basic tools, we prove new existence theorems on generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which includes operator equilibrium problems.

The world solution for world problems : the problem, its cause, its solution

NARCIS (Netherlands)

León, L.

2002-01-01

The book discusses the main world problem of today, which is the gradual, but lethal change of the soil and atmosphere, the main cause, which is the world-wide overpopulation, and the main solution, which is world government by lottocracy. It is a recipe for the solution of the one and only problem

Ethnic differences in problem perception and perceived need for care for young children with problem behaviour.

Science.gov (United States)

Bevaart, Floor; Mieloo, Cathelijne L; Jansen, Wilma; Raat, Hein; Donker, Marianne C H; Verhulst, Frank C; van Oort, Floor V A

2012-10-01

 Problem perception and perceived need for professional care are important determinants that can contribute to ethnic differences in the use of mental health care. Therefore, we studied ethnic differences in problem perception and perceived need for professional care in the parents and teachers of 5- to 6-year-old children from the general population who were selected for having emotional and behavioural problems. A cross-sectional study with data of 10,951 children from grade two of the elementary schools in the Rotterdam-Rijnmond area, The Netherlands. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) as well as questions on problem perception and perceived need for care. The SDQ was used to identify children with emotional and behavioural problems. We included Dutch, Surinamese, Antillean, Moroccan and Turkish children in our sample with high (>P90) SDQ scores (N = 1,215), who were not currently receiving professional care for their problems. Amongst children with high SDQ scores, problem perception was lower in non-Dutch parents than in Dutch parents (49% vs. 81%, p ethnic differences were found in parental perceived need and in problem perception and perceived need reported by teachers. Higher levels of problem perception and perceived need were reported by teachers than by parents in all ethnic groups (PP: 87% vs. 63% and PN: 48% vs. 23%). Child health professionals should be aware of ethnic variations in problem perception as low problem perception in parents of non-Dutch children may lead to miscommunication and unmet need for professional care for the child. © 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.

Case of two electrostatics problems: Can providing a diagram adversely impact introductory physics students’ problem solving performance?

Directory of Open Access Journals (Sweden)

Alexandru Maries

2018-03-01

Full Text Available Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an investigation in which two different interventions were implemented during recitation quizzes in a large enrollment algebra-based introductory physics course. Students were either (i asked to solve problems in which the diagrams were drawn for them or (ii explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed rubrics to score the problem solving performance of students in different intervention groups and investigated ten problems. We found that students who were provided diagrams never performed better and actually performed worse than the other students on three problems, one involving standing sound waves in a tube (discussed elsewhere and two problems in electricity which we focus on here. These two problems were the only problems in electricity that involved considerations of initial and final conditions, which may partly account for why students provided with diagrams performed significantly worse than students who were not provided with diagrams. In order to explore potential reasons for this finding, we conducted interviews with students and found that some students provided with diagrams may have spent less time on the conceptual analysis and planning stage of the problem solving process. In particular, those provided with the diagram were more likely to jump into the implementation stage of problem solving early without fully analyzing and understanding the problem, which can increase the likelihood of mistakes in solutions.

Case of two electrostatics problems: Can providing a diagram adversely impact introductory physics students' problem solving performance?

Science.gov (United States)

Maries, Alexandru; Singh, Chandralekha

2018-06-01

Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an investigation in which two different interventions were implemented during recitation quizzes in a large enrollment algebra-based introductory physics course. Students were either (i) asked to solve problems in which the diagrams were drawn for them or (ii) explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed rubrics to score the problem solving performance of students in different intervention groups and investigated ten problems. We found that students who were provided diagrams never performed better and actually performed worse than the other students on three problems, one involving standing sound waves in a tube (discussed elsewhere) and two problems in electricity which we focus on here. These two problems were the only problems in electricity that involved considerations of initial and final conditions, which may partly account for why students provided with diagrams performed significantly worse than students who were not provided with diagrams. In order to explore potential reasons for this finding, we conducted interviews with students and found that some students provided with diagrams may have spent less time on the conceptual analysis and planning stage of the problem solving process. In particular, those provided with the diagram were more likely to jump into the implementation stage of problem solving early without fully analyzing and understanding the problem, which can increase the likelihood of mistakes in solutions.

Problem-based learning and radiology

International Nuclear Information System (INIS)

Thurley, P.; Dennick, R.

2008-01-01

The Royal College of Radiologists recently published documents setting out guidelines to improve the teaching of radiology to medical students. These included recommendations that clinicians who teach radiology should be aware of newer educational techniques, such as problem-based learning, and should be involved in the development of curricula and assessment in medical schools. This review aims to introduce the educational theories behind problem-based learning and describe how a problem-based learning tutorial is run. The relevance of problem-based learning to radiology and the potential advantages and disadvantages are discussed

Problem solving through recreational mathematics

CERN Document Server

Averbach, Bonnie

1999-01-01

Historically, many of the most important mathematical concepts arose from problems that were recreational in origin. This book takes advantage of that fact, using recreational mathematics - problems, puzzles and games - to teach students how to think critically. Encouraging active participation rather than just observation, the book focuses less on mathematical results than on how these results can be applied to thinking about problems and solving them. Each chapter contains a diverse array of problems in such areas as logic, number and graph theory, two-player games of strategy, solitaire ga

The problems of Visaginas town

International Nuclear Information System (INIS)

Schiurov, V.

1998-01-01

The problems of Visaginas are specific and, first of all, connected with the operation of the Ignalina nuclear power plant and cultural development of Visaginas ethnic minorities, lack of skilled specialists employed in different spheres. Some difficulties we have with the learning of the official language. A strong well-reasoned opinion of the scientists corresponds to our practical directions: the problems of the town of Visaginas are not only the problems of its inhabitants but also a composite part of the problems of the Ignalina nuclear power plant region. (author)

The Effect of Learning Environments Based on Problem Solving on Students' Achievements of Problem Solving

Science.gov (United States)

Karatas, Ilhan; Baki, Adnan

2013-01-01

Problem solving is recognized as an important life skill involving a range of processes including analyzing, interpreting, reasoning, predicting, evaluating and reflecting. For that reason educating students as efficient problem solvers is an important role of mathematics education. Problem solving skill is the centre of mathematics curriculum.…

Open problems in mathematics

CERN Document Server

Nash, Jr, John Forbes

2016-01-01

The goal in putting together this unique compilation was to present the current status of the solutions to some of the most essential open problems in pure and applied mathematics. Emphasis is also given to problems in interdisciplinary research for which mathematics plays a key role. This volume comprises highly selected contributions by some of the most eminent mathematicians in the international mathematical community on longstanding problems in very active domains of mathematical research. A joint preface by the two volume editors is followed by a personal farewell to John F. Nash, Jr. written by Michael Th. Rassias. An introduction by Mikhail Gromov highlights some of Nash’s legendary mathematical achievements. The treatment in this book includes open problems in the following fields: algebraic geometry, number theory, analysis, discrete mathematics, PDEs, differential geometry, topology, K-theory, game theory, fluid mechanics, dynamical systems and ergodic theory, cryptography, theoretical computer sc...

Statistical perspectives on inverse problems

DEFF Research Database (Denmark)

Andersen, Kim Emil

of the interior of an object from electrical boundary measurements. One part of this thesis concerns statistical approaches for solving, possibly non-linear, inverse problems. Thus inverse problems are recasted in a form suitable for statistical inference. In particular, a Bayesian approach for regularisation...... problem is given in terms of probability distributions. Posterior inference is obtained by Markov chain Monte Carlo methods and new, powerful simulation techniques based on e.g. coupled Markov chains and simulated tempering is developed to improve the computational efficiency of the overall simulation......Inverse problems arise in many scientific disciplines and pertain to situations where inference is to be made about a particular phenomenon from indirect measurements. A typical example, arising in diffusion tomography, is the inverse boundary value problem for non-invasive reconstruction...

Scalable algorithms for contact problems

CERN Document Server

Dostál, Zdeněk; Sadowská, Marie; Vondrák, Vít

2016-01-01

This book presents a comprehensive and self-contained treatment of the authors’ newly developed scalable algorithms for the solutions of multibody contact problems of linear elasticity. The brand new feature of these algorithms is theoretically supported numerical scalability and parallel scalability demonstrated on problems discretized by billions of degrees of freedom. The theory supports solving multibody frictionless contact problems, contact problems with possibly orthotropic Tresca’s friction, and transient contact problems. It covers BEM discretization, jumping coefficients, floating bodies, mortar non-penetration conditions, etc. The exposition is divided into four parts, the first of which reviews appropriate facets of linear algebra, optimization, and analysis. The most important algorithms and optimality results are presented in the third part of the volume. The presentation is complete, including continuous formulation, discretization, decomposition, optimality results, and numerical experimen...

A Diagnostic Taxonomy of Adult Career Problems.

Science.gov (United States)

Campbell, Robert E.; Cellini, James V.

1981-01-01

Developed a taxonomy for the differential diagnosis of adult career development problems. Problem categories identified were: (1) problems in career decision making; (2) problems in implementing career plans; (3) problems in organizational/institutional performance; and (4) problems in organizational/institutional adaption. (Author)

Modified and fuzzified general problem solver for 'monkey and banana' problem, 2

International Nuclear Information System (INIS)

Sano, Norihide; Takahashi, Ryoichi.

1991-01-01

The automatic operation is important for the in-service inspection of the operating nuclear power station or the decommission of retired plants. The master and slave control will be introduced for work-robot control. It is desirable that the slave involves the capability of problem solving. This paper assumed that the slave involved the general problem solver algorithm. In view of having solved the puzzle of the 'monkey and banana', the slave system is regarded as the reasonable alternative which incorporates the capability of problem solving. Basically, the GPS solves a problem by reducing the difference between an initial state and a goal state, and hence the performance of GPS depends on selecting the difference to be reduced. The usual GPS is given in advance the ordering which indicates the importance of the differences. In this paper, the GPS was improved by making use of the rules which decide the order. When several choices are found on the given difference, the fuzzified decision to determine the action is demonstrated in this paper. (author)