Using mouse and keyboard under time pressure: preference, strategies and learning

Visually based point-and-click user interfaces have become very common. This increases the need to understand the mechanics in learning and using pointing devices in order to design appropriate human-computer interaction and thereby to help alleviate musculosketetal symptoms. The paper reports a study of preference, strategies and learning in using keyboard and mouse in a tracking task under time pressure. The keyboard was preferred by 11 out of 12 subjects due primarily to comfort, frustration, and visual strain. One of the most distinguishing features in favour of the keyboard was the opportunity to develop a working strategy facilitating learning.     

Fabrication of very high aspect ratio metal nanowires by a self-propulsion mechanism

A novel synthesis method of very high aspect ratio metal nanowires is described. The synthesis utilizes a nanoporous membrane as a template and self-electrophoresis as a directed force that continuously push formed nanowires out of the pores in a rate that is identical to the rate of their elongation. As a result, while the pores of membranes are only 6 microm long, the formed nanowires could be more than 100 microm long.     

The Luria-Nebraska Neuropsychological Battery: Theoretical orientation and comment.

Since the introduction of the Luria-Nebraska Neuropsychological Battery (LNNB), issues related to its understanding, interpretation, and validity have generated much interest. In response to P. A. Spiers's (see record 1981-24833-001) criticism of the battery, the authors suggest that the controversy appears to arise from a divergence in theoretical orientation on the role of quantitative versus qualitative assessment as well as from differences in the understanding of measurement methodology and validity. The present article discusses the theoretical basis from which the LNNB was constructed and describes the process of test interpretation. Previous and current research on use and validity of the battery is presented as it relates to the theoretical and methodological concerns. While basic philosophical differences with other theoretical systems are not likely to be resolved, the authors of the LNNB will continue to emphasize the integration of quantitative and qualitative approaches, both in the use of the LNNB and in the field of neuropsychology in general. It is concluded that the LNNB will continue to be revised on the basis of research findings and experience with the test in different patient populations. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determinants of nocturnal enuresis in England and Scotland in the '90s

The aim of this study was to assess whether changes have occurred in the determinants of nocturnal enuresis in Scotland and England in comparison with previous studies. The study was based on 22 study areas from a representative English sample, 14 areas from a representative Scottish sample, and 20 areas from an English inner-city sample. A total of 14,674 subjects was included in the analysis from 16,835 eligible children in the age range 5 to 11 years. For the main analysis, an enuretic child was one who wet the bed at least once a week. As expected, the frequency of enuresis was higher in boys and decreased markedly with age in both sexes. Bedwetting was more frequent in: Afro-Caribbean children compared with white children in the representative samples (OR 1.72 95% CI 1.22 to 2.42); those whose mothers smoked at least 10 cigarettes at home compared with non-smokers (OR 1.58 95% CI 1.26 to 1.98); children who had disturbed sleep compared with those who slept well (OR 1.96 95% CI 1.53 to 2.51); those with mothers aged less than 20 years at the child's birth compared with mothers in the age range 25 to 34 (OR 1.63 95% CI 1.20 to 2.22); and in the second- or third-born in the family in comparison with the first-born (OR 1.42 95% CI 1.17 to 1.72). Father's social class was associated with enuresis only in girls. Only 50% of the parents consulted a doctor for enuresis in their child. The percentage was even lower in Afro-Caribbean families (33%). Enuresis continues to be a highly prevalent problem and has not decreased over the last 45 years. We confirm that environmental factors are still important in the aetiology of enuresis. It is surprising that despite the availability of effective treatment only half of parents consult a doctor about the problem.     

L4–L5 compression and anterior/posterior joint shear forces in cabin attendants during the initial push/pull actions of airplane meal carts

The aim of the present study was to assess the acute low back load of cabin attendants during cart handling and to identify working situations which present the highest strain on the worker. In a setup, 17 cabin attendants (ten females and seven males) pushed, pulled and turned a 20 kg standard meal cart (L: 0.5 m × W: 0.3 m × H: 0.92 m) loaded with extra 20 kg and 40 kg, respectively on two different surfaces (carpet and linoleum) and at three floor inclinations (−2°, 0° and +2°). Two force transducers were mounted as handles. Two-dimensional movement analysis was performed and a 4D WATBAK modelling tool was used to calculate the acute L4–L5 load.     

Simultaneous determination of nerisopam, a novel anxiolytic agent showing polymorphic metabolism, and its N-acetyl metabolite from human plasma by a validated high performance liquid chromatographic method

OBJECTIVE: Our goal was to determine the effect of chronic and acute umbilical-placental embolization on placental hemodynamic and fetal heart rate patterns in relation to fetal oxygenation in the near-term ovine fetus. STUDY DESIGN: Daily fetal placental embolization was performed during 10 days in 9 sheep fetuses until fetal arterial oxygen content decreased by approximately 30%. Nine control fetuses received saline solution. Mean and pulsatile umbilical blood flow, perfusion pressure, placental vascular resistance, fundamental impedance, pressure pulsatility index, and umbilical artery resistance index corrected to a fetal heart rate of 160 beats/min were measured. On day 10 both groups were acutely embolized until fetal arterial pH decreased to approximately 7.00. Fetal heart rate was measured with the Sonicaid System 8000 (Oxford Sonicaid, Oxford, United Kingdom). RESULTS: Chronic fetal placental embolization was associated with a progressive reduction in umbilical blood flow (p < 0.00001) and fetal arterial oxygen content (p < 0.001) whereas fetal heart rate patterns remained unaltered. A chronic increase in umbilical artery resistance index corrected to a fetal heart rate of 160 beats/min could be entirely explained only if the changes in umbilical artery pressure pulsatility index and the fundamental impedance were taken into account, in addition to the changes observed in placental vascular resistance. During acute embolization leading to a 50% reduction in umbilical blood flow (p < 0.0002) and a three times increase in placental vascular resistance (p < 0.0001), the most consistent change in fetal heart rate patterns related to progressive metabolic acidosis was an 84% decrease in absolute acceleration frequency (p < 0.0001) whereas short-term fetal heart rate variability remained unaltered. CONCLUSION: Changes in umbilical artery resistance index induced by chronic umbilical-placental embolization resulting in fetal hypoxemia occurred before any changes in fetal heart rate patterns were detectable. A decrease in the absolute acceleration frequency was the only component of fetal heart rate patterns related to progressive metabolic acidosis in the near-term ovine fetus.     

Uniaxial, tensile-strained Si devices

Uniaxial, in-plane, tensile straining of silicon devices is reported. Strain is applied via mechanical techniques and then fixed by bonding to an appropriate substrate. Results are reported for diffused resistors and for some metal-oxide semiconductor field effect transistor (MOSFET) devices. Strain is introduced after device processing is complete, which enables full advantage to be taken of mainstream silicon processing technology. This macroscopic method is effective regardless of device size but has particular benefit in the deep submicron region. Mobility conductivity enhancement factors >2 for an applied strain of 0.05% are reported.