4,067 research outputs found
Consolidated fuel reprossing program: The implications of force reflection for teleoperation in space
Previous research on teleoperator force feedback is reviewed and results of a testing program which assessed the impact of force reflection on teleoperator task performance are reported. Force relection is a type of force feedback in which the forces acting on the remote portion of the teleoperator are displayed to the operator by back-driving the master controller. The testing program compared three force reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to tasks components, and variability in forces applied to components during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force relection than they did without it. These data support the hypothesis that force reflection provides useful information for teleoperator users. The earlier literature and the results of the experiment are discussed in terms of their implications for space based teleoperator systems. The discussion described the impact of force reflection on task completion performance and task strategies, as suggested by the literature. It is important to understand the trade-offs involved in using telerobotic systems with and without force reflection
ΦCrAss001 represents the most abundant bacteriophage family in the human gut and infects Bacteroides intestinalis
peer-reviewedCrAssphages are an extensive and ubiquitous family of tailed bacteriophages, predicted to infect bacteria of the order Bacteroidales. Despite being found in ~50% of individuals and representing up to 90% of human gut viromes, members of this viral family have never been isolated in culture and remain understudied. Here, we report the isolation of a CrAssphage (ΦCrAss001) from human faecal material. This bacteriophage infects the human gut symbiont Bacteroides intestinalis, confirming previous in silico predictions of the likely host. DNA sequencing demonstrates that the bacteriophage genome is circular, 102 kb in size, and has unusual structural traits. In addition, electron microscopy confirms that ΦcrAss001 has a podovirus-like morphology. Despite the absence of obvious lysogeny genes, ΦcrAss001 replicates in a way that does not disrupt proliferation of the host bacterium, and is able to maintain itself in continuous host culture during several weeks
On the Effect of Quantum Interaction Distance on Quantum Addition Circuits
We investigate the theoretical limits of the effect of the quantum
interaction distance on the speed of exact quantum addition circuits. For this
study, we exploit graph embedding for quantum circuit analysis. We study a
logical mapping of qubits and gates of any -depth quantum adder
circuit for two -qubit registers onto a practical architecture, which limits
interaction distance to the nearest neighbors only and supports only one- and
two-qubit logical gates. Unfortunately, on the chosen -dimensional practical
architecture, we prove that the depth lower bound of any exact quantum addition
circuits is no longer , but . This
result, the first application of graph embedding to quantum circuits and
devices, provides a new tool for compiler development, emphasizes the impact of
quantum computer architecture on performance, and acts as a cautionary note
when evaluating the time performance of quantum algorithms.Comment: accepted for ACM Journal on Emerging Technologies in Computing
System
Impact of a primary school-based nutrition and physical activity intervention on learners in Kwazulu-Natal, South Africa: A pilot study
Background. The opportunity for children to be physically active during school hours is rapidly decreasing in selected schools. This study evaluated the effects of a nutrition and physical activity (NAP) intervention incorporated within the school curriculum. Study design and methods. A prospective empirical pilot study with an intervention and an assessment of pre- and post-intervention fitness. Learners completed a NAP questionnaire and participated in a battery of fitness tests before and after intervention.
Setting. A purposive sample of four primary schools in KwaZulu-Natal was selected by the provincial Department of Health. Interventions. The NAP intervention was designed to introduce various methods of physical activity and healthy nutritional habits within the school's existing curriculum. Classroom-based intervention materials were developed to provide cost-effective and, more importantly, a sustainable intervention. Results. Post-intervention results showed a significant increase (p<0.05) in the average number of sports participated in by each learner during physical education / life orientation periods. Learners were motivated to participate in physical activity including games and sports during break times. A general increase in after-school activities from pre- to post-intervention per learner was noted.
Conclusion. A school-based physical activity and nutrition intervention programme has the potential to increase the physical activity of learners and to a lesser degree their nutritional behaviour
Financial rogue waves
The financial rogue waves are reported analytically in the nonlinear option
pricing model due to Ivancevic, which is nonlinear wave alternative of the
Black-Scholes model. These solutions may be used to describe the possible
physical mechanisms for rogue wave phenomenon in financial markets and related
fields.Comment: 4 papges, 2 figures, Final version accepted in Commun. Theor. Phys.,
201
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The Quality of Arizona Irrigation Water
This item is part of the Agricultural Experiment Station archive. It was digitized from a physical copy provided by the University Libraries at the University of Arizona. For more information, please email CALS Publications at [email protected]
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British research in accounting and finance (2001–2007): the 2008 research assessment exercise
No abstract available
Use of biomarkers to assess fruit and vegetables intake
A high intake of fruit and vegetables (FV) has been associated with reduced risk of a number of chronic diseases, including CVD. The aim of this review is to describe the potential use of biomarkers to assess FV intake. Traditional methods of assessing FV intake have limitations, and this is likely to impact on observed associations with disease outcomes and markers of disease risk. Nutritional biomarkers may offer a more objective and reliable method of assessing dietary FV intake. Some single blood biomarkers, such as plasma vitamin C and serum carotenoids, are well established as indicators of FV intake. Combining potential biomarkers of intake may more accurately predict overall FV intake within intervention studies than the use of any single biomarker. Another promising approach is metabolomic analysis of biological fluids using untargeted approaches to identify potential new biomarkers of FV intake. Using biomarkers to measure FV intake may improve the accuracy of dietary assessment.authorsversionPeer reviewe
Decuplet Baryon Structure from Lattice QCD
The electromagnetic properties of the SU(3)-flavor baryon decuplet are
examined within a lattice simulation of quenched QCD. Electric charge radii,
magnetic moments, and magnetic radii are extracted from the E0 and M1 form
factors. Preliminary results for the E2 and M3 moments are presented giving the
first model independent insight to the shape of the quark distribution in the
baryon ground state. As in our octet baryon analysis, the lattice results give
evidence of spin-dependent forces and mass effects in the electromagnetic
properties. The quark charge distribution radii indicate these effects act in
opposing directions. Some baryon dependence of the effective quark magnetic
moments is seen. However, this dependence in decuplet baryons is more subtle
than that for octet baryons. Of particular interest are the lattice predictions
for the magnetic moments of and for which new recent
experimental measurements are available. The lattice prediction of the
ratio appears larger than the experimental ratio, while the
lattice prediction for the magnetic moment ratio is in good
agreement with the experimental ratio.Comment: RevTeX manuscript, 34 pages plus 21 figures (available upon request
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