Development and evaluation of a new instrument to measure visual exploration behavior

Effective visual exploration is required for many activities of daily living and instruments to assess visual exploration are important for the evaluation of the visual and the oculomotor system. In this article, the development of a new instrument to measure central and peripheral target recognition is described. The measurement setup consists of a hemispherical projection which allows presenting images over a large area of ±90° horizontal and vertical angle. In a feasibility study with 14 younger (21–49 years) and 12 older (50–78 years) test persons, 132 targets and 24 distractors were presented within naturalistic color photographs of everyday scenes at 10°, 30°, and 50° eccentricity. After the experiment, both younger and older participants reported in a questionnaire that the task is easy to understand, fun and that it measures a competence that is relevant for activities of daily living. A main result of the pilot study was that younger participants recognized more targets with smaller reaction times than older participants. The group differences were most pronounced for peripheral target detection. This test is feasible and appropriate to assess the functional field of view in younger and older adults.

THE DESIGN AND DEVELOPMENT OF A SURVEY INSTRUMENT FOR THE ASSESSMENT OF OCCUPATIONAL STRESS

Using stress and coping as a unifying theoretical concept, a series of five models was developed in order to synthesize the survey questions and to classify information. These models identified the question, listed the research study, described measurements, listed workplace data, and listed industry and national reference data.^ A set of 38 instrument questions was developed within the five coping correlate categories. In addition, a set of 22 stress symptoms was also developed. The study was conducted within two groups, police and professors, on a large university campus. The groups were selected because their occupations were diverse, but they were a part of the same macroenvironment. The premise was that police officers would be more highly stressed than professors.^ Of a total study group of 80, there were 37 respondents. The difference in the mean stress responses was observable between the two groups. Not only were the responses similar within each group, but the stress level of response was also similar within each group. While the response to the survey instrument was good, only 3 respondents answered the stress symptom survey properly. It was determined that none of the 37 respondents believed that they were ill. This perception of being well was also evidenced by the grand mean of the stress scores of 2.76 (3.0 = moderate stress). This also caused fewer independent variables to be entered in the multiple regression model.^ The survey instrument was carefully designed to be universal. Universality is the ability to transcend occupational or regional definitions as applied to stress. It is the ability to measure responses within broad categories such as physiological, emotional, behavioral, social, and cognitive functions without losing the ability to measure the detail within the individual questions, or the relationships between questions and categories.^ Replication is much easier to achieve with standardized categories, questions, and measurement procedures such as those developed for the universal survey instrument. Because the survey instrument is universal it can be used as an analytical device, an assessment device, a basic tool for planning and a follow-up instrument to measure individual response to planned reductions in occupational stress. (Abstract shortened with permission of author.) ^

Development and Test of a Neutron Imaging Setup at the PGAA Instrument at FRM II

We report on the developments of a neutron tomography setup at the instrument for prompt gamma-ray activation analysis (PGAA) at the Maier-Leibnitz Zentrum(MLZ). The recent developments are driven by the idea of combining the spatial information obtained with neutron tomography with the elemental information determined with PGAA, i.e. to further combine both techniques to an investigative technique called prompt gamma activation imaging (PGAI).At the PGAA instrument, a cold neutron flux of up to 6 x 1010 cm-2 s-1 (thermal equivalent) is available in the focus of an elliptically tapered neutron guide. In the reported experiments, the divergence of the neutron beam was investigated, the resolution of the installed detector system tested, and a proof-of-principle tomography experiment performed. In our study a formerly used camera box was upgraded with a better camera and an optical resolution of 8 line pairs/mm was achieved. The divergence of the neutron beam was measured by a systematic scan along the beam axis. Based on the acquired data, a neutron imaging setup with a L/D ratio of 200 was installed. The resolution of the setup was testedin combination with a gadolinium test target and different scintillator screens. The test target was irradiated at two positions to determine the maximum resolution and the resolution at the actual sample position. The performance of the installed tomography setup was demonstrated bya tomography experiment of an electric amplifier tube.

Measuring health state preferences for hemophilia: Development of a disease-specific utility instrument

Research has shown that disease-specific health related quality of life (HRQoL) instruments are more responsive than generic instruments to particular disease conditions. However, only a few studies have used disease-specific instruments to measure HRQoL in hemophilia. The goal of this project was to develop a disease-specific utility instrument that measures patient preferences for various hemophilia health states. The visual analog scale (VAS), a ranking method, and the standard gamble (SG), a choice-based method incorporating risk, were used to measure patient preferences. Study participants (n = 128) were recruited from the UT/Gulf States Hemophilia and Thrombophilia Center and stratified by age: 0–18 years and 19+. ^ Test retest reliability was demonstrated for both VAS and SG instruments: overall within-subject correlation coefficients were 0.91 and 0.79, respectively. Results showed statistically significant differences in responses between pediatric and adult participants when using the SG (p = .045). However, no significant differences were shown between these groups when using the VAS (p = .636). When responses to VAS and SG instruments were compared, statistically significant differences in both pediatric (p < .0001) and adult (p < .0001) groups were observed. Data from this study also demonstrated that persons with hemophilia with varying severity of disease, as well as those who were HIV infected, were able to evaluate a range of health states for hemophilia. This has important implications for the study of quality of life in hemophilia and the development of disease-specific HRQoL instruments. ^ The utility measures obtained from this study can be applied in economic evaluations that analyze the cost/utility of alternative hemophilia treatments. Results derived from the SG indicate that age can influence patients' preferences regarding their state of health. This may have implications for considering treatment options based on the mean age of the population under consideration. Although both instruments independently demonstrated reliability and validity, results indicate that the two measures may not be interchangeable. ^

A novel scanning lens instrument for evaluating Fresnel lens performance: equipment development and initial results

A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

Building from building waste: The development of an instrument to determine the circularity of materials from the existing building stock in order to maximise high quality reuse

On a global level the population growth and increase of the middle class lead to a growing demand on material resources. The built environment has an enormous impact on this scarcity. In addition, a surplus of construction and demolition waste is a common problem. The construction industry claims to recycle 95% of this waste but this is in fact mainly downcycling. Towards the circular economy, the quality of reuse becomes of increasing importance. Buildings are material warehouses that can contribute to this high quality reuse. However, several aspects to achieve this are unknown and a need for more insight into the potential for high quality reuse of building materials exists. Therefore an instrument has been developed that determines the circularity of construction waste in order to maximise high quality reuse. The instrument is based on three principles: ‘product and material flows in the end of life phase’, ‘future value of secondary materials and products’ and ‘the success of repetition in a new life cycle’. These principles are further divided into a number of criteria to which values and weighting factors are assigned. A degree of circularity can then be determined as a percentage. A case study for a typical 70s building is carried out. For concrete, the circularity is increased from 25% to 50% by mapping out the potential for high quality reuse. During the development of the instrument it was clarified that some criteria are difficult to measure. Accurate and reliable data are limited and assumptions had to be made. To increase the reliability of the instrument, experts have reviewed the instrument several times. In the long-term, the instrument can be used as a tool for quantitative research to reduce the amount of construction and demolition waste and contribute to the reduction of raw material scarcity.