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PubMed1993

Oculomotor functions in a Swedish population of dyslexic and normally reading children.

Eighty-six nine-year-old dyslexic children were matched to control children with regard to age, sex, class in school, and intelligence. Orthoptic and eye movement analysis were performed on all children. It was concluded that the dyslexic pupils did not differ significantly from control children in terms of strabismus, accommodation, stereo acuity, vergence function or ocular dominance. Eye movement recordings did not show any qualitative differences between the groups in vergence dynamics during synoptophore investigations.

Accommodation, Ocular↗

PubMed2004

Effect of patient sex, clinician sex, and sex role on the diagnosis of Antisocial Personality Disorder: models of underpathologizing and overpathologizing biases.

This study examined the influence of patient sex and clinician sex and sex role for a case, meeting minimum diagnostic criteria for Antisocial Personality Disorder, in which patient sex was varied. The purpose was to provide an in-depth evaluation of the process by which patient sex and characteristics of clinicians may contribute to bias in personality disorder diagnoses. Psychologists (N = 167) read two cases, including the target case, and provided symptom ratings and diagnoses. A sex-unspecified condition served as a baseline to assess for over- and underpathologizing bias, and diagnoses based on the symptom ratings were compared to assigned diagnoses. Clinician sex role was assessed using the Bem Sex Role Inventory-Short Form. Results revealed that bias occurred when the patient's sex (female) was inconsistent with the gender weighting of the symptoms in the case (masculine), but the direction of the bias was consistent with sex roles (underdiagnosis of sex-role-inconsistent diagnoses, overdiagnosis of sex-role-consistent diagnoses). Path models of over- and underdiagnostic bias were developed using structural equation modeling. Patient sex had a direct effect on diagnostic ratings whereas clinician sex role had an indirect effect through symptom ratings.

Adult↗

PubMed1995

Visual and visuomotor performance in dyslexic children.

The present study was designed to compare the performance of nine dyslexic boys and nine age- and IQ-matched controls on tasks which presumably tap visual functions dependent on the subcortical magnocellular (M) pathway (flicker sensitivity) and the cortical dorsal stream (stereoacuity, structure-from-motion, visuomotor control). Increasing evidence suggests that dyslexics experience impairments in M-system functioning. In keeping with previous work supporting this conclusion, dyslexic subjects in the present study were found to have reduced sensitivity to flicker relative to controls. Given that the M system provides the predominant input to the dorsal stream, it was expected that reduced functioning of the M system in dyslexics would result in disruptions of functions related to this cortical visual pathway. Indeed, dyslexic subjects in the present study were found to be less efficient at recognizing structure-from-motion and less accurate at grasping objects precisely. They also showed a mild impairment in stereoacuity. These results, then, lend some support to the hypothesis that dyslexic individuals should show deficiencies on tasks dependent on dorsal stream processing of visual information.

Arm↗

PubMed2005

Initial clinical results of an in vivo dosimeter during external beam radiation therapy.

PURPOSE: An implantable radiation dosimeter has been developed to monitor dose delivered at depth in patients undergoing external beam therapy. A clinical pilot study was conducted to test the safety, efficacy, and utility of the device. METHODS AND MATERIALS: Ten patients, all with unresectable malignant disease, were enrolled to assess implantation risk and movement of the device in the body and to compare the in vivo measured dose to the value predicted by the treatment planning system software. RESULTS: Migration of the sensor away from the point of original placement was noted in only 1 patient (due to unconsolidated host tissue) and no adverse events were recorded during the implantation procedure or thereafter. Daily dose measurements were recorded successfully for all sensors in all patients. Variance between measured and predicted dose values was reported as a frequency of error at the > or =5% and > or =8% levels. The error frequency at the > or =8% level was as high as 47%, 29%, and 21% for lung, prostate, and rectal tumors, respectively. CONCLUSIONS: The implantable dosimeter was found to be safe and effective in measuring dose at depth. There are many factors that can influence delivered dose, and the implantable dosimeter measures the net effect of these factors. The daily sensor readings provide a new tool for rigorous treatment quality assurance.

Humans↗

PubMed2002

Visual deficits in a patient with 'kaleidoscopic disintegration of the visual world'.

We describe psychophysical, neuropsychological and neuro-ophthalmological studies of visual abilities in a patient who, following a right hemisphere stroke, had difficulty in combining parts of objects into a whole and in reading. Strikingly, her perceptual problems were accentuated when the objects moved or when she moved. Formal testing showed that her main deficits were in depth perception, various tasks of motion and object recognition of degraded stimuli. But low-level detection and discrimination of form and color were normal. Despite her deficits in visual motion and degraded static-object recognition, her visual recognition of 'biological motion' stimuli was normal. Structural magnetic resonance imaging revealed an infarct in the ventro-medial occipito-temporal region, extending ventro-laterally and leading to a 'kaleidoscopic disintegration of visible objects'.

Adrenalectomy↗

PubMed2025

insilicoSV: a flexible grammar-based framework for structural variant simulation and placement.

SUMMARY: Structural variants (SVs) are key drivers of genetic variation and disease in the genome. Their discovery remains challenging, however, in large part due to the scarcity of validated SV callsets and comprehensive benchmarks, which are essential for method development and evaluation. The growing number of data-driven learning-based approaches for SV discovery, in particular, requires large, diverse, and well-balanced training datasets to achieve reliable performance. To address this need, SV simulation has served as a key tool for assessing method performance and training SV models. However, existing SV simulators only support a fixed and limited set of SV classes and do not provide fine-grained control over the placement of SVs within specific contexts of the genome. Here we present insilicoSV, a versatile framework for SV simulation, which models SVs using a simple and flexible grammar, allowing users to easily define standard and custom arbitrary genome rearrangements, as well as encode genome placement constraints. This design allows insilicoSV to naturally support new and bespoke SV types, such as the complex rearrangements of cancer genomes. In addition to grammar-based modeling, insilicoSV provides built-in support for 26 predefined SV types, placement of user-provided SVs, small variant simulation, streamlined workflows for the simulation of genome evolution and genome mixtures, read simulation, alignment, and visualization. These features enable the creation of comprehensive genomic datasets for a variety of downstream applications, such as in-depth benchmarking of alignment and variant calling methods, as well as training of data-driven learning-based approaches for SV detection. AVAILABILITY AND IMPLEMENTATION: insilicoSV is available under the MIT license at https://github.com/PopicLab/insilicoSV and https://doi.org/10.5281/zenodo.17402009.

Software↗

PubMedDate not supplied

Tests of an electron monitor for routine quality control measurements of electron energies.

The depth dose for electrons is sensitive to energy and the AAPM Task Group 24 has recommended that tests be performed at monthly intervals to assure electron beam energy constancy by verifying the depth for the 80% dose to within +/- 3 mm. Typically, this is accomplished by using a two-depth dose ratio technique. Recently, a new device, the Geske monitor, has been introduced that is designed for verifying energy constancy in a single reading. The monitor consists of nine parallel plate detectors that alternate with 5-mm-thick absorbers made of an aluminum alloy. An evaluation of the clinical usefulness of this monitor for the electron beams available on a Varian Clinac 20 has been undertaken with respect to energy discrimination. Beam energy changes of 3 mm of the 80% dose give rise to measurable output changes ranging from 1.7% for 20-MeV electron beams to 15% for 6-MeV electron beams.

Electrons↗

PubMed1993

Haptic identification of objects and their depictions.

Haptic identification of real objects is superior to that of raised two-dimensional (2-D) depictions. Three explanations of real-object superiority were investigated: contribution of material information, contribution of 3-D shape and size, and greater potential for integration across the fingers. In Experiment 1, subjects, while wearing gloves that gently attenuated material information, haptically identified real objects that provided reduced cues to compliance, mass, and part motion. The gloves permitted exploration with free hand movement, a single outstretched finger, or five outstretched fingers. Performance decreased over these three conditions but was superior to identification of pictures of the same objects in all cases, indicating the contribution of 3-D structure and integration across the fingers. Picture performance was also better with five fingers than with one. In Experiment 2, the subjects wore open-fingered gloves, which provided them with material information. Consequently, the effect of type of exploration was substantially reduced but not eliminated. Material compensates somewhat for limited access to object structure but is not the primary basis for haptic object identification.

Adult↗

PubMed2004

Ocular component measurement using the Zeiss IOLMaster.

PURPOSE: Axial length is traditionally measured using A-scan ultrasound. The IOLMaster is a new instrument that uses partial coherence interferometry to measure axial length. We compared the repeatability of these techniques for both an experienced and an inexperienced observer, the agreement between the two techniques, and the effect of cycloplegia on IOLMaster measurements. METHODS: Five measurements of axial length and three measurements of anterior chamber depth were taken with the IOLMaster in two sessions separated by 1 to 12 days in 20 young adults. The two examiners each took measurements, and the subject was then cyclopleged with 1% tropicamide. The IOLMaster readings were then repeated by both examiners, followed by five ultrasound readings. Repeatability was evaluated by calculating the difference between measurements from the two sessions. The mean and standard deviation of these differences was then used to determine the 95% limits of agreement (LoA) for each technique. In addition, the agreement between the IOLMaster and ultrasound was assessed, along with the effect of cycloplegia on IOLMaster readings. RESULTS: The IOLMaster was more repeatable than ultrasound. For axial length, the 95% LoA were -0.11 to +0.07 mm, -0.06 to +0.05 mm, and -0.25 to +0.35 mm, for noncycloplegic IOLMaster, cycloplegic IOLMaster, and ultrasound, respectively. The two instruments showed modest agreement with each other (mean difference, +0.12 mm; 95% LoA, -0.39 to +0.64 mm; p > 0.0125). Cycloplegia had no significant effect on IOLMaster axial length measurements. The 95% LoA for anterior chamber depth measurement were -0.11 to +0.18 mm, -0.06 to +0.04 mm, and -0.19 to +0.21 mm, for noncycloplegic IOLMaster, cycloplegic IOLMaster, and ultrasound, respectively. The IOLMaster gave significantly longer anterior chamber depths than ultrasound (mean, +0.18 mm; 95% LoA, -0.02 to +0.37 mm; p < 0.0125), and cycloplegia produced significantly deeper anterior chamber depths using the IOLMaster (mean, +0.12 +/- 0.09 mm; 95% LoA, -0.05 to +0.29 mm; t = 6.17; p < 0.001). The experienced observer's measurements were more repeatable than the inexperienced observer's for ultrasound, but not for the IOLMaster. CONCLUSIONS: The superior repeatability of the IOLMaster suggests that it should become the standard for axial length measurement. The 95% limits of agreement for the cycloplegic measurements correspond to a change in refractive error of +/-0.12 D.

Adult↗

PubMed2002

Optimal set-up for ultrasound guided punctures using new scanner applications: an in-vitro study.

OBJECTIVE: To investigate if US-visualisation of the needle tip echo during US-guided punctures could be improved by use of new technological applications. METHOD: an US-guided 18 G Trocar needle was inserted into targets of a puncture phantom. The punctures were performed in series of 10 using different settings of the US-scanner (GE Logic 700 Expert). At 7-cm of puncture depth the quality of the echo was tested using four different settings; normal (N), N + automatic tissue optimising (ATO), coded harmonic imaging (CHI), CHI + ATO and at 13-cm of puncture depths six different settings; N, N + ATO, coded excitation (CE), CE+ATO, CHI, CHI+ATO. In total 100 (40 + 60) images were randomly numbered and read independently by three radiologists with regard to scoring of the quality of the echoes from the needle tip, needle shaft and the target. RESULTS: US visualisation of the needle tip was significantly (P < 0.005) improved as compared to normal settings (N) when the settings of ATO and CE were used. CHI resulted in the lowest score. A high agreement between observers was registered. Similar results were registered with regard to scorings from the needle shaft and target. CONCLUSION: Not only changes of needle designs and puncture techniques can enhance echoes from the needle but also changes in the settings of the US-scanner with the use of new technological applications can improve visualisation of the needle echo.

Humans↗

PubMed1998

Monte Carlo dosimetry study of a 6 MV stereotactic radiosurgery unit.

Small-field and stereotactic radiosurgery (SRS) dosimetry with radiation detectors, used for clinical practice, have often been questioned due to the lack of lateral electron equilibrium and uncertainty in beam energy. A dosimetry study was performed for a dedicated 6 MV SRS unit, capable of generating circular radiation fields with diameters of 1.25-5 cm at isocentre using the BEAM/EGS4 Monte Carlo code. With this code the accelerator was modelled for radiation fields with a diameter as small as 0.5 cm. The radiation fields and dosimetric characteristics (photon spectra, depth doses, lateral dose profiles and cone factors) in a water phantom were evaluated. The cone factor (St) for a specific cone c at depth d is defined as St(d, c) = D(d, c)/D(d, c(ref)), where c(ref) is the reference cone. To verify the Monte Carlo calculations, measurements were performed with detectors commonly used in SRS such as small-volume ion chambers, a diamond detector, TLDs and films. Results show that beam energies vary with cone diameter. For a 6 MV beam, the mean energies in water at the point of maximum dose for a 0.5 cm cone and a 5 cm cone are 2.05 MeV and 1.65 MeV respectively. The values of St obtained by the simulations are in good agreement with the results of the measurements for most detectors. When the lateral resolution of the detectors is taken into account, the results agree within a few per cent for most fields and detectors. The calculations showed a variation of St with depth in the water. Based on calculated electron spectra in water, the validity of the assumption that measured dose ratios are equal to measured detector readings was verified.

Brain↗

PubMed2001

Dosimetry of 192Ir sources used for endovascular brachytherapy.

An in-phantom calibration technique for 192Ir sources used for endovascular brachytherapy is presented. Three different source lengths were investigated. The calibration was performed in a solid phantom using a Farmer-type ionization chamber at source to detector distances ranging from 1 cm to 5 cm. The dosimetry protocol for medium-energy x-rays extended with a volume-averaging correction factor was used to convert the chamber reading to dose to water. The air kerma strength of the sources was determined as well. EGS4 Monte Carlo calculations were performed to determine the depth dose distribution at distances ranging from 0.6 mm to 10 cm from the source centre. In this way we were able to convert the absolute dose rate at 1 cm distance to the reference point chosen at 2 mm distance. The Monte Carlo results were confirmed by radiochromic film measurements, performed with a double-exposure technique. The dwell times to deliver a dose of 14 Gy at the reference point were determined and compared with results given by the source supplier (CORDIS). They determined the dwell times from a Sievert integration technique based on the source activity. The results from both methods agreed to within 2% for the 12 sources that were evaluated. A Visual Basic routine that superimposes dose distributions, based on the Monte Carlo calculations and the in-phantom calibration, onto intravascular ultrasound images is presented. This routine can be used as an online treatment planning program.

Angioplasty, Balloon, Coronary↗

PubMed1997

Acetabular dysplasia and osteoarthritis of the hip in elderly white women.

OBJECTIVES: To examine the association of acetabular dysplasia and osteoarthritis (OA) of the hip among elderly white women. METHODS: Pelvic radiographs from a sample of 165 white women aged 65 and above with radiographic hip OA and 88 white women aged 65 and above without radiographic changes of hip OA were read for evidence of acetabular dysplasia by a single trained investigator. Acetabular dysplasia was assessed using measurements of the centre edge angle and the acetabular depth, which are both reduced in this condition. Odds ratios for the association between acetabular dysplasia and hip OA were estimated using logistic regression analysis. RESULTS: Fourteen (3.4%) hips had a centre edge angle < 25 degrees, 46 (11.2%) hips had an acetabular depth of < 9 mm, and 54 (13.2%) hips had acetabular dysplasia defined as either of the above. Hips with OA had a small, but not statistically significant, increased prevalence of abnormal centre edge angle (odds ratio: 1.43; 95% confidence intervals: 0.46, 4.46), abnormal acetabular depth (1.47; 0.78, 2.77) and acetabular dysplasia (1.33; 0.74, 2.40). CONCLUSION: These results do not support the hypothesis that mild acetabular dysplasia accounts for a substantial proportion of hip OA in elderly white women. A study with a much larger sample size would be required to rule out a weak association between dysplasia and hip OA of the magnitude actually observed in our study.

Acetabulum↗

PubMed2000

Experience of fibromyalgia. Qualitative study.

OBJECTIVE: To explore illness experiences of patients diagnosed with fibromyalgia. DESIGN: Qualitative method of in-depth interviews. SETTING: Midsize city in Ontario. PARTICIPANTS: Seven patients diagnosed with fibromyalgia. METHOD: Seven in-depth interviews were conducted to explore the illness experience of patients diagnosed with fibromyalgia. All interviews were audiotaped and transcribed verbatim. All interview transcriptions were read independently by the researchers, who then compared and combined their analysis. Final analysis involved examining all interviews collectively, thus permitting relationships between and among central themes to emerge. The analysis strategy used a phenomenologic approach and occurred concurrently rather than sequentially. MAIN FINDINGS: Themes that emerged from the interpretive analysis depict patients' journeys along a continuum from experiencing symptoms, through seeking a diagnosis, to coping with the illness. Experiencing symptoms was composed of four subcategories: pain, a precipitating event, associated symptoms, and modulating factors. Seeking a diagnosis entailed frustration and social isolation. Confirmation of diagnosis brought relief as well as anxiety about the future. After diagnosis, several steps led to creation of adaptive coping strategies, which were influenced by several factors. CONCLUSION: Findings suggest that the conventional medical model fails to address the complex experience of fibromyalgia. Adopting a patient-centred approach is important for helping patients cope with this disease.

Adaptation, Psychological↗

PubMed2000

Laboratory evaluation of two bi-level toothbrush products for subgingival access and gingival margin cleaning.

Recent technological advances have enabled the production of split or feathered endings of individual toothbrush filaments. The purpose of this laboratory study was to compare a bi-level manual toothbrush containing standard end-rounded bristles with the same shaped toothbrush containing feathered filaments, 3 mm deep, on the outer raised bi-level rows to achieve subgingival access (SA) and remove artificial plaque at the gingival margin, or gingival margin cleaning (GMC). Simulated gingivae were prepared with a 0.2 mm space between the gingivae and tooth surface. The toothbrushes were aligned with the papillae at the gingival margin, and were tested using wet brushing conditions for 60 seconds at two strokes per second with a 15 mm stroke. Four toothbrushes of each type were evaluated four times, for a total of 16 assays per design. The SA maximum depth was recorded on pressure-sensitive paper under the simulated gingivae, and the length of gingival margin cleaning was recorded as the GMC efficacy. Readings were performed with 3x magnification by one investigator. In these laboratory assays, the bi-level toothbrush with feathered outer-row bristles significantly (p < 0.001) increased the ability of the bristles to achieve SA by 35.7% and GMC efficacy by 54.5% compared to an identical bi-level toothbrush with end-rounded bristles.

Dental Plaque↗

PubMed1998

Surface-specific electrical occlusal caries diagnosis: reproducibility, correlation with histological lesion depth, and tooth type dependence.

Electrical conductance measurements are being used experimentally for occlusal caries detection. Recently, it was suggested to cover the fissure system with a conducting medium, resulting in a surface-specific measurement. It was the aim of this study to determine in vitro the reproducibility of this modified technique for occlusal caries in posterior teeth, to determine for a large study sample the correlation between the electrical measurements and histological lesion depth, and to evaluate the difference between results for premolars and molars. For the reproducibility determination, surface-specific electrical resistance measurements were made using a sample of 68 posterior teeth. Eight operators performed measurements on all teeth, and repeated measurements on 24 teeth. The validity study included the previous sample and the collected samples from two more studies, resulting in a total sample of 325 posterior teeth. One operator had performed electrical resistance measurements on all teeth in the sample. Reproducibility was good: mean Pearson's correlation coefficient 0.89 (+/-0.05) for interexaminer correlation, and 0.86 (+/-0.12) for intra-examiner correlation, using log (resistance) as the result parameter. The correlation coefficient between log(resistance) and histological lesion depth for the large sample was -0.78 for all teeth, -0.64 for premolars, and -0.73 for molars. The regression line for molars was located below the regression line for premolars: at a hypothetical histology score of 2.5 (a dentine caries threshold) the estimated resistance threshold would be 507 kOmega for premolars, and 233 kOmega for molars. Converted to Electronic Caries Monitor (ECM) readings, the difference is about 1.4 on the ECM scale. It was concluded that the in vitro reproducibility of the described surface-specific method for electrical resistance measurement is very good, even for inexperienced operators. The correlation between measurements and histological lesion depth is moderate to good. The method is sensitive to electrode area differences, which will result in different clinical cut-offs for caries diagnosis in premolar and molar teeth.

Bicuspid↗

PubMed2006

Overseas nurses' experiences of equal opportunities in the NHS in England.

PURPOSE: To explore the experiences of overseas black and minority ethnic nurses in the National Health Service (NHS) in the south of England. METHODS: Semi-structured in-depth interviews were conducted with 12 overseas black and minority ethnic nurses. All interviews were taped, transcribed verbatim and analysed using thematic analysis. All transcripts were read and re-read to elicit general themes. FINDINGS: Qualitative data analysis was undertaken using Van Manen framework and this enabled a number of themes to be identified that were part of overseas black and minority ethnic nurses' experience, however, two main themes would be discussed in this study. Firstly, unequal opportunities in career advancement and secondly, unequal opportunities for skill development and training. Both themes affected overseas nurses chances of promotion in the NHS. RESEARCH LIMITATION/IMPLICATIONS: The study has identified a notably gap in the implementation of equal opportunity policies and suggests that a more transparent implementation of such policies is needed in the NHS in the UK where this study was conducted. Additionally, more research is needed to determine whether overseas nurses in other areas experience similar problems. PRACTICAL IMPLICATIONS: The findings of this study could encourage managers to re-examine their equal opportunity policies in the light of these findings. Although this study has explored overseas nurses experiences, the findings cannot be generalised to the wider population. ORIGINALITY VALUE: The differences experienced by overseas nurses in relation to career opportunities and skill development and training.

Adult↗

PubMed1998

Women's perceptions and concerns about menopause.

The purpose of this study was to explore the following questions: What are the perceptions of midlife women as to the care they receive from a variety of healthcare providers? What are the issues and concerns that influence their decision making about hormonal therapy? What strategies do women find helpful in accommodating to menopause? What are the knowledge and perceptions/role of the partner during the menopause transition? The research design for this study used a nonrandom survey. The nonrandom convenience sample consisted of 320 midlife women 46-55 years of age. Data were gathered via a mailed self-administered Menopause Questionnaire. Descriptive statistics were used to analyze the survey data. Qualitative data revealed more in-depth and personal comments from women concerning menopause. The most significant findings were that respondents (1) were in conflict about hormone therapy (HT), yet they had read extensively about menopause and used a variety of strategies to cope with symptoms; (2) reported that they received conflicting information and advice about menopause from a variety of sources and expressed concerns about not being fully informed by their healthcare providers; and (3) who received care from nurse practitioners (NPs) were quite satisfied with their care.

Attitude to Health↗