Different computer tasks affect the exposure of the upper extremity to biomechanical risk factors

In order to determine differences in biomechanical risk factors across computer tasks, a repeated measures laboratory experiment was completed with 30 touch-typing adults (15 females and 15 males). The participants completed five different computer tasks: typing text, completing an html-based form with text fields, editing text within a document, sorting and resizing objects in a graphics task and browsing and navigating a series of intranet web pages. Electrogoniometers and inclinometers measured wrist and upper arm postures, surface electromyography measured muscle activity of four forearm muscles and three shoulder muscles and a force platform under the keyboard and force-sensing computer mouse measured applied forces. Keyboard-intensive tasks were associated with less neutral wrist postures, larger wrist velocities and accelerations and larger dynamic forearm muscle activity. Mouse-intensive tasks (graphics and intranet web page browsing) were associated with less neutral shoulder postures and less variability in forearm muscle activity. Tasks containing a mixture of mouse and keyboard use (form completion and text editing) were associated with higher shoulder muscle activity, larger range of motion and larger velocities and accelerations of the upper arm. Comparing different types of computer work demonstrates that mouse use is prevalent in most computer tasks and is associated with more constrained and non-neutral postures of the wrist and shoulder compared to keyboarding.     

Quantifying low back peak and cumulative loads in open and senior sheep shearers in New Zealand: examining the effects of a trunk harness

Sheep shearing requires shearers to adopt sustained flexed postures for prolonged periods of time and has been associated with an increased risk of developing low back pain (LBP). However, these postures do not generally result in acute compressive values at L4/L5 exceeding the action limit proposed by the National Institute for Occupational Safety and Health, despite the high prevalence of LBP in this occupation. Therefore, it may not be peak loading that is responsible for LBP in this occupation but instead it may be the effect of cumulative loading over the course of a workday. The primary purpose of this research was to quantify the low back cumulative load exposure in 12 sheep shearers with and without the aid of a commercial trunk harness. Results revealed a significant reduction in the magnitude of cumulative compression with the use of the trunk harness and therefore its use may potentially reduce the risk of injury. The use of the trunk harness also reduced the time spent in axially twisted postures, which have been associated with LBP. However, using the trunk harness also resulted in increased time spent in laterally bent postures, which has been associated with increased risk for pain and injury.     

High-Throughput Screening for High Affinity Antibodies

The UCB SLAM process described here has had a positive and dramatic effect on the way we select therapeutic candidate antibodies. An example of the number of cells that can be screened using UCB SLAM is shown in Table 2. UCB previously used the hybridoma method to generate antibodies for both research and for therapy.^{[5] and [6]} This method, we believed, was not particularly amenable to automation, due to the large amount of cell culture involved in both setting up the fusion and then maintaining the hybridoma cell lines, although this approach has been adopted by others.⁷ The in vitro culture of B cells, combined with the process automation has allowed many more antibodies to be screened, with hybridoma only those B cells that have fused with the myeloma are available for screening, this is only a small proportion of the total number of B cells. UCB SLAM B cell cultures can be screened a week after they are set up compared with 2–3 weeks for hybridoma. Advances in the molecular biology have allowed us to move away from the time-consuming dilution cloning of cells to select antibodies; the antibody genes can be isolated, sequenced, and recombinant antibody transiently expressed in 2 weeks. The method does not require a species specific, myeloma cell line as a fusion partner, which means there is no constraint on B cell source species. The lack of a B cell fusion event means that a highly efficient sampling of the B cell repertoire can be achieved. We have found the process to be applicable to generating research reagents, high quality antibodies to animal target antigens.⁸ These research reagents can be raised to different target antigen epitopes than used in both in vitro and in vivo mechanistic and disease models. The research reagents are a significant aid to investigate the complex biology of our targets. The lack of species-specific fusion partners makes this approach a challenge for hybridoma, particularly when there is a need to generate antibodies to mouse and rat antigens.     

Security through Diversity: Leveraging Virtual Machine Technology

Biologists have long recognized the dangers of the lack of diversity or monocultures in biological systems. Recently, it has been noted that much of the fragility of our networked computing systems can be attributed to the lack of diversity or monoculture of our software systems. The problem is severe. Because it is virtually inevitable that software will ship with flaws, our software monoculture leaves systems open to large-scale attacks by knowledgeable adversaries. Inspired by the resilience of diverse biological systems, the authors developed the Genesis Software Development Toolchain. An innovative aspect of Genesis is the use of an application-level virtual machine technology that enables the application of diversity transforms at any point in the software toolchain. Using Genesis, they authors demonstrated that diversity, when judiciously applied, is a practical and effective defense against two widely used types of attacks—return-to-libc and code injection.     

User performance and attitude towards schemes for alphanumeric data entry using restricted input devices

. Results are reported from two usability trials in which a total of 14 schemes for alphanumeric data entry on television screens were evaluated. The seven schemes in the first trial used only the navigation and select keys on the TV remote control unit. The second trial used the best scheme from the first trial (slightly modified), a further six schemes using different combinations of the navigation and alphanumeric keys and a portable, infra-red keyboard. In both trials task completion rates and times were measured together with the number of keystrokes. User preferences were measured using attitude questionnaires and explicit ranking of the schemes. As expected, the keyboard was, overall, the best scheme-though not the most accurate. Where only a limited range of input keys were available, grid display schemes were preferred over menus and dynamic displays. Where an alphanumeric keypad was available on the remote control unit, a multiple press scheme was marginally preferred.     

An observation on probability versus randomness with applications to complexity classes

Every class C of languages satisfying a simple topological condition is shown to have probability one if and only if it contains some language that is algorithmically random in the sense of Martin-Löf. This result is used to derive separation properties of algorithmically random oracles and to give characterizations of the complexity classesP, BPP, AM, andPH in terms of reducibility to such oracles. These characterizations lead to results like:P =NP if and only if an algorithmically random set exists that is _btt ^P -hard forNP.The work of the first author was supported in part by the Alexander-von-Humboldt-Stiftung and by the National Science Foundation under Grant CCR-8913584 while he visited the Lehrstuhl für Theoretische Informatik, Institut für Informatik, Universität Würzburg, Germany. The work of the second author was supported in part by the National Science Foundation under Grant CCR-8809238 and in part by DIMACS, where he was a visitor while a portion of his work was done.     

Depressed Mood and Smoking Experimentation Among Preteens.

The authors examined children's depressed mood, parental depressed mood, and parental smoking in relation to children's smoking susceptibility and experimentation over 20 months in a cohort of 418 preteens (ages 10-12 at baseline) and their parents. Depressed mood in preteens was strongly related to experimentation but not to susceptibility. In cross-sectional analyses parental depressed mood was related to children's experimentation, but in longitudinal analyses parental depressed mood at baseline did not differentiate children who experimented from those who did not. Although parental smoking was strongly related to experimentation, it was not related to susceptibility either cross-sectionally or longitudinally. Depressed mood among preteens and parents appeared to be more strongly related to children's smoking behaviors than to their intentions to smoke. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Latent features in similarity judgments: a nonparametric bayesian approach

One of the central problems in cognitive science is determining the mental representations that underlie human inferences. Solutions to this problem often rely on the analysis of subjective similarity judgments, on the assumption that recognizing likenesses between people, objects, and events is crucial to everyday inference. One such solution is provided by the additive clustering model, which is widely used to infer the features of a set of stimuli from their similarities, on the assumption that similarity is a weighted linear function of common features. Existing approaches for implementing additive clustering often lack a complete framework for statistical inference, particularly with respect to choosing the number of features. To address these problems, this article develops a fully Bayesian formulation of the additive clustering model, using methods from nonparametric Bayesian statistics to allow the number of features to vary. We use this to explore several approaches to parameter estimation, showing that the nonparametric Bayesian approach provides a straightforward way to obtain estimates of both the number of features and their importance.