The application of ergonomics to consumer product evaluation

Consumer products may be evaluated by technical tests or by ergonomics assessments. If an ergonomics assessment is required, then three types of test are available to the researcher. These are the user trial, the expert appraisal and the performance test. These three methods are described briefly and some advantages, disadvantages and issues arising from each are discussed. It is concluded that although the user trial will always assume an important role for the evaluation of many products, expert appraisals and performance tests can prove to be cost effective methods in certain circumstances. Some controversial areas requiring further research are highlighted.     

TopCat: data mining for topic identification in a text corpus

TopCat (topic categories) is a technique for identifying topics that recur in articles in a text corpus. Natural language processing techniques are used to identify key entities in individual articles, allowing us to represent an article as a set of items. This allows us to view the problem in a database/data mining context: Identifying related groups of items. We present a novel method for identifying related items based on traditional data mining techniques. Frequent itemsets are generated from the groups of items, followed by clusters formed with a hypergraph partitioning scheme. We present an evaluation against a manually categorized ground truth news corpus; it shows this technique is effective in identifying topics in collections of news articles.     

Indoor mold levels and current asthma among school‐aged children in Saskatchewan,Canada

Current knowledge regarding the association between indoor mold exposures and asthma is still limited. The objective of this case–control study was to investigate the relationship between objectively measured indoor mold levels and current asthma among school‐aged children. Parents completed a questionnaire survey of health history and home environmental conditions. Asthma cases had a history of doctor‐diagnosed asthma or current wheeze without a cold in the past 12 months. Controls were age‐ and sex‐matched to cases. Vacuumed dust samples were collected from the child's indoor play area and mattress. Samples were assessed for mold levels and quantified in colony‐forming units (CFU). Sensitization to mold allergens was also determined by skin testing. Being a case was associated with family history of asthma, pet ownership, and mold allergy. Mold levels (CFU/m²) in the dust samples of children's mattress and play area floors were moderately correlated (r = 0.56; P < 0.05). High mold levels (≥30 000 CFU/m²) in dust samples from play [adjusted odds ratio (aOR) = 2.6; 95% CI: 1.03–6.43] and mattress (aOR) = 3.0; 95% CI: 1.11–8.00) areas were significantly associated with current asthma. In this study high levels of mold are a risk factor for asthma in children.     

Prediction of rock brittleness using nondestructive methods for hard rock tunneling

The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks(ANN). Herein hard rock brittleness is defined using Yagiz’method. A predictive model is developed using a comprehensive database compiled from 30 years’ worth of rock tests at the Earth Mechanics Institute(EMI), Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.     

Fully-coupled simulations of thermally-induced cracking in pegmatite due to microwave irradiation

Fully-coupled thermo-mechanical simulations are implemented in COMSOL Multiphysics to investigate micro-scale stress-strain variability in pegmatite specimens subjected to thermal loading using microwaves. Thermally-induced compressive and tensile stresses increase as the microwave irradiation duration increases. The dielectric constant, coefficient of expansion, and type and size of mineralogical boundary have significant impacts on the responses of the rock to microwave irradiation. The maximum principal stress of the chlorite is the smallest, indicating that the chlorite experiences the most damage under microwave irradiation, followed by the quartz. The maximum principal stress values of plagioclase and orthoclase are larger, indicating that they are likely to incur the least damage. Where quartz or chlorite is dominant, the resulting von Mises stresses are consistently higher after 120 s of microwave irradiation. The rate of generation of von Mises stresses increases most rapidly along the interface between quartz and plagioclase, and the interface between quartz and orthoclase, followed by the interface between quartz and chlorite, and finally the interface between plagioclase and orthoclase. The presented modeling approach provides a practical method to investigate stress-strain relationships within mineralogical boundaries inside a rock thin section.     

Modulation of whole body protein metabolism, during and after exercise, by variation of dietary protein

The aim of this study was to investigate dietary protein-induced changes in whole body leucine turnover and oxidation and in skeletal muscle branched chain 2-oxo acid dehydrogenase (BCOADH) activity, at rest and during exercise. Postabsorptive subjects received a primed constant infusion of L-[1-13C,15N]leucine for 6 h, after previous consumption of a high- (HP; 1.8 g . kg-1 . day-1, n = 8) or a low-protein diet (LP; 0.7 g . kg-1 . day-1, n = 8) for 7 days. The subjects were studied at rest for 2 h, during 2-h exercise at 60% maximum oxygen consumption, then again for 2 h at rest. Exercise induced a doubling of both leucine oxidation from 20 micromol . kg-1 . h-1 and BCOADH percent activation from 7% in all subjects. Leucine oxidation was greater before (+46%) and during (+40%, P < 0.05) the first hour of exercise in subjects consuming the HP rather than the LP diet, but there was no additional change in muscle BCOADH activity. The results suggest that leucine oxidation was increased by previous ingestion of an HP diet, attributable to an increase in leucine availability rather than to a stimulation of the skeletal muscle BCOADH activity.     

Characterizing spatial distribution of trap captures of beetles in retail pet stores using SADIE software

The weevils, Sitophilus spp., drug store beetle, Stegobium paniceum (L.), and red flour beetle, Tribolium castaneum (Herbst) in two retail pet stores in Kansas, USA, were sampled with pitfall traps on five separate occasions before and four separate occasions after a thorough sanitation in areas with high trap captures. Trap captures of Sitophilus spp. and S. paniceum in store 1 and those of T. castaneum and Sitophilus spp. in store 2, were analyzed using the Spatial Analysis of Distance IndicEs (SADIE^®) software. Captures of Sitophilus spp. in store 1 and T. castaneum in store 2 increased immediately after sanitation, but subsequently were similar to levels before sanitation, whereas captures of S. paniceum in store 1 and Sitophilus spp. in store 2 were unaffected by sanitation. In store 1, S. paniceum trap captures were randomly distributed on all sampling occasions, while Sitophilus spp. captures were spatially aggregated immediately before and after sanitation. During the 6 months of trapping, the Sitophilus spp. trap capture centroids gradually moved northwards, and those of S. paniceum moved southwards. In store 2, trap captures of T. castaneum and Sitophilus spp. were uniformly distributed before sanitation and were predominantly spatially aggregated after sanitation. During the 6 months of trapping, trap capture centroids of both T. castaneum and Sitophilus spp. gradually moved northwards. The impact of a thorough sanitation performed once on the spatial distribution patterns of insects in the two retail stores was not consistent. Sanitation was also ineffective in reducing captures of the insect species.     

Expect the worse or hope for the best? Prenatal diagnosis of geleophysic dysplasia

Geleophysic dysplasia is a rare, autosomal recessive disorder which causes disproportionate short stature associated with severe physical handicaps, but is compatible with survival into adulthood. We present a case, a first-born child, where genetic counselling difficulties arose following ultrasound recognition of short-limbed dwarfism in association with polyhydramnios and an initial incorrect prenatal diagnosis of lethal chondrodysplasia. After birth of the surviving affected infant, the parents had great difficulty accepting that there had been a prenatal misdiagnosis and they were greatly disappointed by our inability to predict the postnatal survival of an infant to whom no hope of life had previously been given. The correct diagnosis was not made until the proband was nearly 1 year old, and the true prognosis then became clearer. This experience underlines the relative ease of prenatal recognition of skeletal growth abnormalities compared with the considerable difficulties experienced in reaching a precise diagnosis. Thus, following prenatal diagnosis of unspecified chondrodysplasia when parents seek definite information about the prognosis, the temptation to be either overpessimistic or overoptimistic should be avoided.