Qualitative Errors Research Articles

Object and proper name retrieval in temporal lobe epilepsy: A study of difficulties and latencies

Retrieving a specific name is sometimes difficult and can be even harder when pathology affects the temporal lobes. Word finding difficulties have been well documented in temporal lobe epilepsy (TLE) but analyses have mostly concentrated on the study of accuracy. Our aim here was to go beyond simple accuracy and to provide both a quantitative and a qualitative assessment of naming difficulties and latencies in patients with TLE. Thirty-two patients with temporal lobe epilepsy (16 with epilepsy affecting the cerebral hemisphere dominant for language (D-TLE) and 16 with epilepsy affecting the cerebral hemisphere non-dominant for language (ND-TLE)) and 34 healthy matched control subjects were included in the study. The experiment involved naming 70 photographs of objects and 70 photographs of celebrities as fast as possible. Accuracy and naming reaction times were recorded. Following each trial, a questionnaire was used to determine the specific nature of each subject's difficulty in retrieving the name (e.g., no difficulty, paraphasia, tip of the tongue, feeling of knowing the name, etc). Reaction times were analysed both across subjects and across trials. D-TLE patients showed consistent and quasi-systematic impairment compared to matched control subjects on both object and famous people naming. This impairment was characterized not only by lower accuracy but also by more qualitative errors and tip of the tongue phenomena. Furthermore, minimum reaction times were slowed down by about 70 ms for objects and 150 ms for famous people naming. In contrast, patients with ND-TLE were less impaired, and their impairment was limited to object naming. These results suggest that patients with TLE, in particular D-TLE, show a general impairment of lexical access. Furthermore, there was evidence of subtle difficulties (increased reaction times) in patients with TLE.

An error taxonomy system for analysis of haemodialysis incidents.

This paper describes the development of a haemodialysis error taxonomy system for analysing incidents and predicting the safety status of a dialysis organisation. The error taxonomy system was developed by adapting an error taxonomy system which assumed no specific specialty to haemodialysis situations. Its application was conducted with 1,909 incident reports collected from two dialysis facilities in Japan. Over 70% of haemodialysis incidents were reported as problems or complications related to dialyser, circuit, medication and setting of dialysis condition. Approximately 70% of errors took place immediately before and after the four hours of haemodialysis therapy. Error types most frequently made in the dialysis unit were omission and qualitative errors. Failures or complications classified to staff human factors, communication, task and organisational factors were found in most dialysis incidents. Device/equipment/materials, medicine and clinical documents were most likely to be involved in errors. Haemodialysis nurses were involved in more incidents related to medicine and documents, whereas dialysis technologists made more errors with device/equipment/materials. This error taxonomy system is able to investigate incidents and adverse events occurring in the dialysis setting but is also able to estimate safety-related status of an organisation, such as reporting culture.

Conjugate heat transfer LES of thermal mixing in a T-junction

Turbulent mixing of hot and cold fluids may lead to high-cycle thermal fatigue in piping of nuclear power plants. In this work, the mixing in a T-junction experiment is studied by large-eddy simulation (LES). Conjugate heat transfer (CHT) between fluid and pipe wall is studied by replacing the plexiglass pipe of the experiment with a steel one.Different inlet and wall boundary conditions are first considered. Steady and turbulent inlets are compared, as well as adiabatic and CHT wall conditions. The turbulent inlets are created by using the vortex method which is validated for fully developed flow. The inlets are shown to have only small effect in bulk of the flow, but non-negligible effect near walls. The adiabatic and CHT cases show practically no difference in the logarithmic layer and upward, whereas near walls the difference becomes significant due to thermal inertia of the pipe wall. In bulk of the flow, the mean and fluctuating quantities show good agreement with the experiment.CHT simulations by using different meshes and flow velocities are then considered. A coarse mesh is found to yield qualitative agreement but significant errors in e.g. Reynolds stresses near walls. Temperature fluctuation intensity at the pipe inner surface is fairly similar for both meshes. Normalized profiles and spectra for different velocities are qualitatively similar, but some differences exist e.g. in distributions of wall temperature fluctuation intensity.

Spatio-temporal dynamics of oxygen storage and release in a three-way catalytic converter

A physics based one-dimensional transient seven partial differential equation model is proposed to study the oxygen storage dynamics and cold start behavior of a three-way catalytic converter. The model uses the recently published simplified kinetic model, is computationally efficient and may be used for offline TWC outer loop controller design and validation. The proposed TWC model is validated using emissions data collected in a vehicle over multiple drive cycles including FTP cycles. The internal mass transfer approximation is confirmed by comparing with a detailed washcoat diffusion–reaction model and is observed to be consistent for all practical purposes. The results are also used to study the qualitative and quantitative errors in emission and oxygen storage predictions caused by axially averaging thus identifying the region of applicability of the simpler axially averaged seven ordinary differential equation model.

The gray zone of the qualitative assessment of respiratory changes in inferior vena cava diameter in ICU patients

IntroductionTransthoracic echocardiography (TTE) is a useful tool for minimally invasive hemodynamic monitoring in the ICU. Dynamic indices (such as the inferior vena cava distensibility index (dIVC)) can be used to predict fluid responsiveness in mechanically ventilated patients. Although quantitative use of the dIVC has been validated, the routinely used qualitative (visual) approach had not been assessed before the present study.MethodsQualitative and quantitative assessments of the dIVC were compared in a prospective, observational study. After operators with differing levels in critical care echocardiography had derived a qualitative dIVC, the last (expert) operator performed a standard, numeric measurement of the dIVC (referred to as the quantitative dIVC). Two groups of patients were separated into two groups: group (dIVC < 18%) and group (dIVC ≥ 18%).ResultsIn total, 114 patients were assessed for inclusion, and 97 (63 men and 34 women) were included. The mean sensitivity and specificity values for qualitative assessment of the dIVC by an intensivist were 80.7% and 93.7%, respectively. A qualitative evaluation detected all quantitative dIVCs >40%. Most of the errors concerned quantitative dIVCs of between 15% and 30%. In the dIVC <18% group, two qualitative evaluation errors were noted for quantitative dIVCs of between 0 and 10%. The average of positive predictive values and negative predictive values for qualitative assessment of the dIVC by residents, intensivists and cardiologists were 83%, 83%, and 90%; and 92%, 94%, and 90%, respectively. The Fleiss kappa for all operators was estimated to be 0.68, corresponding to substantial agreement.ConclusionThe qualitative dIVC is a rather easy and reliable assessment for extreme numeric values. It has a gray zone between 15% and 30%. The highest and lowest limitations of the gray area are rather tedious to define.Despite reliability of the qualitative assessment when it comes to extreme to numerical values, the quantitative dIVC measurement must always be done within a hemodynamic assessment for intensive care patients. The qualitative approach can be easily integrated into a fast hemodynamic evaluation by using portable ultrasound scanner for out-of-hospital patients.

Qualitative Neuropsychological Measures: Normative Data on Executive Functioning Tests from the Framingham Offspring Study

Background/Study Context: Studies have found that executive functioning is affected early in the pathophysiological processes associated with Alzheimer's disease and vascular dementia. There also exists a range of functioning on executive tasks during normal aging. Although qualitative data are commonly utilized in clinical practice for evaluating subtle changes in cognitive functioning and diagnostic discernment, it is not clear whether error responses used in clinical practice are also evident as normative behavior. Methods: As part of an extensive battery of neuropsychological tests, executive functioning measures (i.e., Trail Making Test Part B, Similarities and Verbal Fluency tests) were administered via standardized administration prescript. Regression analyses were used to determine associations between vascular aging indices and qualitative performance measures. Descriptive statistics are included for 1907 cognitively normal individuals. Results: Results suggest that although qualitative errors do occur, they are relatively infrequent within a presumably cognitively normal sample. Error commission rates on executive functioning tests are significantly associated with both age and education. Conclusion: Provided is a baseline profile of errors committed on tests of executive function across a range of age and educational levels. The normative data sets are included, stratified by age and educational achievement, for which to compare qualitative test performance of clinical and research populations.

Benefit–cost analysis of non-marginal climate and energy projects

Conventional benefit–cost analysis incorporates the normally reasonable assumption that the policy or project under examination is marginal. Among the assumptions this entails is that the policy or project is small, so the underlying growth rate of the economy does not change. However, this assumption may be inappropriate in some important circumstances, including in climate-change and energy policy. One example is global targets for carbon emissions, while another is a large renewable energy project in a small economy, such as a hydropower dam. This paper develops some theory on the evaluation of non-marginal projects, with empirical applications to climate change and energy. We examine the conditions under which evaluation of a non-marginal project using marginal methods may be wrong, and in our empirical examples we show that both qualitative and large quantitative errors are plausible.

Multicentre evaluation of Ziehl-Neelsen and light-emitting diode fluorescence microscopy in China

To assess the feasibility of using light-emitting diode fluorescence microscopy (LED-FM) in peripheral laboratories in China. The performance of LED-FM and Ziehl-Neelsen (ZN) microscopy was compared on slides directly prepared from the sputum of tuberculosis (TB) suspects and follow-up patients on treatment. The examination time, fading of fluorescence-stained slides, average unit cost and qualitative user appraisal of LED-FM were also analysed. Among 11 276 slides, the smear-positive rate for LED-FM was 11.2% (1263/11 276), 2.6% (294/11 276) higher than that of ZN (8.6%, 969/11 276; χ(2) 263.5, P < 0.05). The examination time for LED-FM (120.0 ± 38.9 seconds) was shorter than that for ZN (206.3 ± 75.9 s; t = 28.12, P < 0.05). For smear fading, quantitative and qualitative errors occurred within respectively 7.8 and 7.7 weeks. The average unit costs for ZN and LED-FM were respectively US$2.20 ± 0.58 and US$1.97 ± 0.71 (t = 5.08, P < 0.05). LED-FM was accepted by most laboratory technicians. LED-FM compared favourably with ZN, with a higher smear-positive detection rate, a shorter examination time and lower unit examination cost. LED-FM may be an alternative to ZN as a cost-effective method for detecting bacilli in peripheral laboratories in China.

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Introduction: The quality of team performance during medical crises impacts patient outcomes. Team performance can be enhanced by simulated or case-based education. Survival after pediatric cardiac arrest is excellent when effective CPR is performed. Measuring team performance during CPR events can identify errors, allowing development of focused team training. Multiple personnel are involved in resuscitative events and hence, multidisciplinary feedback of perceived errors must be sought. Hypothesis: There is a high rate of qualitative errors that occur during CPR events in the PICU and discordance in perception of errors by team members. Methods: A survey was created of demographics and 3 broad categories of errors- 1. Systems issues 2. Improper BLS/PALS application 3. Crisis resource management (CRM) deficiencies. Personnel conducting the surveys were educated about error categories and debriefing techniques. For all cardiopulmonary arrests(CPAs) in the PICU, the Critical Care (CCM) Attending, Fellow, PICU nurse and respiratory therapist that participated in the resuscitation were interviewed, using formatted, yet open-ended questions. Results: There were 30 CPA events from February to July 2012. 6 patients had 2 events each. Spontaneous circulation returned in 24 events (80%). 21 of the 24 patients survived to hospital discharge (84%). The team leader did multidisciplinary code debriefing following 10 events (33%). 360 degree surveys were successfully done for all team members in 28 cases(93%). Only 2 events(6%) were perceived as error-free by all primary respondents. Systems issues were identified by at least 1 team member in 18 events(60%), BLS/PALS deficiencies in 18 events(60%) and CRM deficiencies in 25 events(83%). More than 1 category of error was identified in 23 events(76%). In 14 events(46%), there was lack of clarity about team leadership. Conclusions: There is a significant rate of errors in PICU CPR team performance. Ample opportunity exists to improve the quality of CPR through team training. Based on our results, CRM is the commonest category of qualitative deficiencies during CPAs and must be primarily targeted during multidisciplinary simulation training and mock codes to enhance patient care.

On the dynamics of tapping mode atomic force microscope probes

A mathematical model is developed to investigate the grazing dynamics of tapping mode atomic force microscopes (AFM) subjected to a base harmonic excitation. A multimode Galerkin approximation is utilized to discretize the nonlinear partial differential equation of motion governing the cantilever response and associated boundary conditions and obtain a set of nonlinearly coupled ordinary differential equations governing the time evolution of the system dynamics. A comprehensive numerical analysis is performed for a wide range of the excitation amplitude and frequency. The tip oscillations are examined using nonlinear dynamic tools through several examples. The non-smoothness in the tip/sample interaction model is treated rigorously. A higher-mode Galerkin analysis indicates that period doubling bifurcations and chaotic vibrations are possible in tapping mode microscopy for certain operating parameters. It is also found that a single-mode Galerkin approximation, which accurately predicts the tip nonlinear responses far from the sample, is not adequate for predicting all of the nonlinear phenomena exhibited by an AFM, such as grazing bifurcations, and leads to both quantitative and qualitative errors.

Moving through virtual reality without moving?

Virtual reality (VR) technology is increasingly used in spatial cognition research, as it offers high experimental control and interactivity in naturalistic multi-modal environments, something that is difficult to achieve in real-world settings. Even in the most sophisticated and costly VR systems, people do not necessarily perceive and behave as they would in the real world. This might be related to our inability to use embodied (and thus often highly automated and effective) spatial orientation processes in VR. While real-world locomotion affords automatic and obligatory spatial updating of our self-to-surrounding relationships, such that we easily remain oriented during simple perspective changes, the same is not necessarily true in VR. This can lead to striking systematic and qualitative errors such as failures to update rotations ("Nonturner" behavior). Here, we investigated whether rich naturalistic visual stimuli in immersive VR might be sufficient to compensate for the lack of physical motion. To this end, 24 participants performed point-to-origin tasks after visually simulated excursions along streets of varying curvature in a naturalistic virtual city. Most (21/24) participants properly updated simulated self-motions and showed only moderate regression toward mean pointing responses. 3/24 participants, however, exhibited striking "Nonturner" behavior in that they pointed as if they did not update the visually simulated turns and their heading had not changed. This suggests that our immersive naturalistic VR stimuli were an improvement over prior optic flow stimuli, but still insufficient in eliciting obligatory spatial updating that supported correct point-to-origin responses in all participants.

Computer-Aided Fetal Cardiac Scanning using 2D Ultrasound

Fetal heart biometry is an indicator for providing information about the presence of heart chambers, their growth, and well being. As a clinical routine, ultrasonic scanning based fetal biometry is performed during the second trimester by skilled specialists. Such procedures are often considered tedious and time consuming. Detection of congenital heart abnormalities, such as septal defects, affects the proper functioning of the heart during the growth of the fetus, and such defects can be identified if the fetal heart structure and its features like size, shape, and symmetry are monitored. Recently, attempts have been made to provide computer-aided automated procedure where the performance depends on the efficacy of the developed algorithms. This work focuses on computer aided automated fetal cardiac scanning using 2-D ultrasonic imaging from fetal heart biometry. The process involves extracting frames from the cine-loop sequences followed by removal of noise using morphological filters. The chamber region is recognized by introducing automated region of interest (ROI). Experimental simulation study demonstrates the efficiency of algorithm in detecting the shape of each chamber. The identified chamber shape will further facilitate in automated measurement of fetal heart chamber and thus reduces the qualitative visualization errors.

Atomistic simulation of ion solvation in water explains surface preference of halides

Water is a demanding partner. It strongly attracts ions, yet some halide anions—chloride, bromide, and iodide—are expelled to the air/water interface. This has important implications for chemistry in the atmosphere, including the ozone cycle. We present a quantitative analysis of the energetics of ion solvation based on molecular simulations of all stable alkali and halide ions in water droplets. The potentials of mean force for Cl - , Br - , and I - have shallow minima near the surface. We demonstrate that these minima derive from more favorable water–water interaction energy when the ions are partially desolvated. Alkali cations are on the inside because of the favorable ion–water energy, whereas F - is driven inside by entropy. Models attempting to explain the surface preference based on one or more ion properties such as polarizability or size are shown to lead to qualitative and quantitative errors, prompting a paradigm shift in chemistry away from such simplifications.

Reference Accuracy in the General Surgery Literature

Reference inaccuracy in scientific articles brings the scientific validity of the research into question and may create difficulty when accessing the cited background data. The objective of this study was to examine the reference accuracy in the general surgery literature and its correlation with the journal impact factor. Five general surgery journals were chosen with varying impact factors. From the year 2007, one issue was randomly chosen from each journal, and from each issue 180 citations were randomly chosen for review. Three investigators evaluated the chosen references for primary, citational, and quotational errors. The impact factor of each journal was compared to the percentage of errors detected. The total number of errors per journal ranged from 31.3 to 39.3%, with a total of 35.4% of all citations reviewed containing some type of error. The most common error type detected was incorrect citation of the primary source supporting a statement, the incidence of which ranged from 13.8 to 25.2%, depending on the journal, and accounting for 53.6% of the total errors found. Citational errors, which included incorrect author names, pagination, dates, and issue and volume numbers, ranged from 1.8 to 18.1% and accounted for 20.4% of the total errors detected. Qualitative errors, which occurred when the author misquoted another author's written assertions or conclusions, ranged from 7.4 to 16.0% and accounted for 34.7% of the total errors detected. Quantitative errors (misquoted numerical data) ranged from 3.1 to 8.6% and accounted for 17.9% of the total errors detected. No association between impact factor and error rate was demonstrated. Reference inaccuracy is common in the general surgery literature. The impact factor has no clear association with the error rate, demonstrating that journal quality does not necessarily correlate with reference quality. Further investigation into potential methods for improving reference accuracy in the general surgery literature is warranted.

Koopmans’ condition for density-functional theory

In approximate Kohn-Sham density-functional theory, self-interaction manifests itself as the dependence of the energy of an orbital on its fractional occupation. This unphysical behavior translates into qualitative and quantitative errors that pervade many fundamental aspects of density-functional predictions. Here, we first examine self-interaction in terms of the discrepancy between total and partial electron removal energies, and then highlight the importance of imposing the generalized Koopmans' condition -- that identifies orbital energies as opposite total electron removal energies -- to resolve this discrepancy. In the process, we derive a correction to approximate functionals that, in the frozen-orbital approximation, eliminates the unphysical occupation dependence of orbital energies up to the third order in the single-particle densities. This non-Koopmans correction brings physical meaning to single-particle energies; when applied to common local or semilocal density functionals it provides results that are in excellent agreement with experimental data -- with an accuracy comparable to that of GW many-body perturbation theory -- while providing an explicit total energy functional that preserves or improves on the description of established structural properties.

Revising the Panko–Halverson taxonomy of spreadsheet errors

Error taxonomies are useful because different types of errors have different commission and detection rates and because error mitigation techniques often are only useful for some types of errors. In the early 1990s, Panko and Halverson developed a spreadsheet error taxonomy. This paper updates that taxonomy to reflect human error research more fully. The taxonomy focuses on quantitative errors during development and testing but notes that qualitative errors are very important and that errors occur in all stages of the system development life cycle.

Adaptation and validation of standardized aphasia tests in different languages: Lessons from the Boston Diagnostic Aphasia Examination - Short Form in Greek.

The aim of the current study was to adapt the Boston Diagnostic Aphasia Examination – Short Form (BDAE-SF) [1] to the Greek language and culture, determine the influence of demographic variables on performance and in particular the effects of age and education, develop normative data, and examine the discriminative validity of the test for acute stroke patients. A sample of 129 community healthy adults participated in the study (66 women), covering a broad range of ages and education levels so as to maximize representation of the Greek population and be able to examine the effects of age and education in language performance. Regression models showed that, overall, younger and more educated individuals presented higher performance on several subtests. Normative data for the Greek population are presented in percentile tables. Neurological patients' performance was compared to that of the neurologically intact population using Wilcoxon's rank sum test and for the most part was found to be significantly inferior, indicating good discriminant validity of the test. Qualitative errors of patients diagnosed with aphasia on the test are presented, and limitations and generalizable strengths of this adaptation are discussed.

Adaptation and Validation of Standardized Aphasia Tests in Different Languages: Lessons from the Boston Diagnostic Aphasia Examination–Short Form in Greek

The aim of the current study was to adapt the Boston Diagnostic Aphasia Examination – Short Form (BDAE-SF) [1] to the Greek language and culture, determine the influence of demographic variables on performance and in particular the effects of age and education, develop normative data, and examine the discriminative validity of the test for acute stroke patients. A sample of 129 community healthy adults participated in the study (66 women), covering a broad range of ages and education levels so as to maximize representation of the Greek population and be able to examine the effects of age and education in language performance. Regression models showed that, overall, younger and more educated individuals presented higher performance on several subtests. Normative data for the Greek population are presented in percentile tables. Neurological patients' performance was compared to that of the neurologically intact population using Wilcoxon's rank sum test and for the most part was found to be significantly inferior, indicating good discriminant validity of the test. Qualitative errors of patients diagnosed with aphasia on the test are presented, and limitations and generalizable strengths of this adaptation are discussed.

A Major Determinant for Binding and Aminoacylation of tRNA Ala in Cytoplasmic Alanyl-tRNA Synthetase Is Mutated in Dominant Axonal Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth disease (CMT) is the most common cause of inherited peripheral neuropathy, with an estimated frequency of 1/2500. We studied a large family with 17 patients affected by the axonal form of CMT (CMT2). Analysis of the 15 genes or loci known to date was negative. Genome-wide genotyping identified a CMT2 locus in 16q21-q23 between D16S3050 and D16S3106. The maximum two-point LOD score was 4.77 at theta = 0 for marker D16S3050. Sequencing of candidate genes identified a unique mutation, c.986G>A (p.Arg329His), affecting a totally conserved amino acid in the helical domain of cytoplasmic alanyl-tRNA synthetase (AlaRS). A second family with the same mutation and a different founder was then identified in a cohort of 91 CMT2 families. Although mislocation of mutant Arg329His-AlaRS in axons remains to be evaluated, experimental data point mostly to a quantitative reduction in tRNA(Ala) aminoacylation. Aminoacylation and editing functions closely cooperate in AlaRS, and Arg329His mutation could also lead to qualitative errors participating in neurodegeneration. Our report documents in 18 patients the deleterious impact of a mutation in human cytoplasmic AlaRS and broadens the spectrum of defects found in tRNA synthetases. Patients present with sensory-motor distal degeneration secondary to predominant axonal neuropathy, slight demyelination, and no atypical or additional CNS features.

Parallel Realities: Exploring Poverty Dynamics Using Mixed Methods in Rural Bangladesh

This paper explores the implications of using two methodological approaches to study poverty dynamics in rural Bangladesh. Using data from a unique longitudinal study, we show how different methods lead to very different assessments of socio-economic mobility. We suggest five ways of reconciling these differences: considering assets in addition to expenditures, proximity to the poverty line, other aspects of well-being, household division, and qualitative recall errors. Considering assets and proximity to the poverty line along with expenditures resolves three-fifths of the qualitative and quantitative differences. Use of such integrated mixed-methods can therefore improve the reliability of poverty dynamics research.