3,363 research outputs found

    Interactive Gaming Reduces Experimental Pain With or Without a Head Mounted Display

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    While virtual reality environments have been shown to reduce pain, the precise mechanism that produces the pain attenuating effect has not been established. It has been suggested that it may be the ability to command attentional resources with the use of head mounted displays (HMDs) or the interactivity of the environment. Two experiments compared participants’ pain ratings to high and low levels of electrical stimulation while engaging in interactive gaming with an HMD. In the first, gaming with the HMD was compared to a positive emotion induction condition; and in the second experiment the HMD was compared to a condition in which the game was projected onto a wall. Interactive gaming significantly reduced numerical ratings of painful stimuli when compared to the baseline and affect condition. However, when the two gaming conditions were directly compared, they equally reduced participants’ pain ratings. These data are consistent with past research showing that interactive gaming can attenuate experimentally induced pain and its effects are comparable whether presented in a head mounted display or projected on a wall

    Beryllium in Ultra-Lithium-Deficient Halo Stars - The Blue Straggler Connection

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    There are nine metal-deficient stars that have Li abundances well below the Li plateau that is defined by over 100 unevolved stars with temperatures above 5800 K and values of [Fe/H] << −-1.0. Abundances of Be have been determined for most of these ultra-Li-deficient stars in order to investigate the cause of the Li deficiencies. High-resolution and high signal-to-noise spectra have been obtained in the Be II spectral region near 3130 \AA for six ultra-Li-deficient stars with the Keck I telescope and its new uv-sensitive CCD on the upgraded HIRES. The spectrum synthesis technique has been used to determine Be abundances. All six stars are found to have Be deficiencies also. Two have measurable - but reduced - Be and four have only upper limits on Be. These results are consistent with the idea that these Li- and Be-deficient stars are analogous to blue stragglers. The stars have undergone mass transfer events (or mergers) which destroy or dilute both Li and Be. The findings cannot be matched by the models that predict that the deficiencies are due to extra-mixing in a subset of halo stars that were initially rapid rotators, with the possible exception of one star, G 139-8. Because the ultra-Li-deficient stars are also Be-deficient, they appear to be genuine outliers in population of halo stars used to determine the value of primordial Li; they no longer have the Li in their atmospheres that was produced in the Big Bang.Comment: 17 pages of text, 12 figures, 3 tables Submitted to Ap

    Energy transfer in nonlinear network models of proteins

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    We investigate how nonlinearity and topological disorder affect the energy relaxation of local kicks in coarse-grained network models of proteins. We find that nonlinearity promotes long-range, coherent transfer of substantial energy to specific, functional sites, while depressing transfer to generic locations. Remarkably, transfer can be mediated by the self-localization of discrete breathers at distant locations from the kick, acting as efficient energy-accumulating centers.Comment: 4 pages, 3 figure

    Beryllium in the Ultra-Lithium-Deficient,Metal-Poor Halo Dwarf, G186-26

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    The vast majority of low-metal halo dwarfs show a similar amount of Li; this has been attributed to the Li that was produced in the Big Bang. However, there are nine known halo stars with T >> 5900 K and [Fe/H] << −-1.0 that are ultra-Li-deficient. We have looked for Be in the very low metallicity star, G 186-26 at [Fe/H] = −-2.71, which is one of the ultra-Li-deficient stars. This star is also ultra-Be deficient. Relative to Be in the Li-normal stars at [Fe/H] = −-2.7, G 182-26 is down in Be by more than 0.8 dex. Of two potential causes for the Li-deficiency -- mass-transfer in a pre-blue straggler or extra rotationally-induced mixing in a star that was initially a very rapid rotator -- the absence of Be favors the blue-straggler hypothesis, but the rotation model cannot be ruled-out completely.Comment: Accepted for Ap.J. Letters 10 pages, 4 figure

    Influence of surface passivation on ultrafast carrier dynamics and terahertz radiation generation in GaAs

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    The carrier dynamics of photoexcited electrons in the vicinity of the surface of (NH4)2S-passivated GaAs were studied via terahertz (THz) emission spectroscopy and optical-pump THz-probe spectroscopy. THz emission spectroscopy measurements, coupled with Monte Carlo simulations of THz emission, revealed that the surface electric field of GaAs reverses after passivation. The conductivity of photoexcited electrons was determined via optical-pump THz-probe spectroscopy, and was found to double after passivation. These experiments demonstrate that passivation significantly reduces the surface state density and surface recombination velocity of GaAs. Finally, we have demonstrated that passivation leads to an enhancement in the power radiated by photoconductive switch THz emitters, thereby showing the important influence of surface chemistry on the performance of ultrafast THz photonic devices.Comment: 4 pages, 3 figures, to appear in Applied Physics Letter

    The translation of indonesia west java at a glance

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    the focus of the book makes it particularly appropriate for require core courses in accounting, in which many of the studentsare not planning to take further elective accounting courses. we believe that if a core course stresses the more analytical uses of accounting information by managers and outside analysts rather than procedural details that practicing accountant needs to know, then thoose students who do not take further accounting course will be left with a positive view of the immportance of accounting rather than with the negative "bean counter" stereotype.table of contents1. Financial Accounting2. The Nature and Purpose of Accounting3. Basic Accounting Concepts: The Balance Sheet4. Basic Accounting Concepts: The Income Statement5. Accounting Records and Systems6. Revenue and Monetary Assets7. Cost of Sales and Inventories8. Long-lived Non-Monetary Assets9. Sources of Capital: Debt10. Sources of Capital: Owners' Equity11. Other Non-Owner Items that Affect Owner's Equity12. The Statement of Cash Flows13. Acquisitions and Consolidated Statements14. Financial Statement Analysis15. Understanding Financial Statements16. Management Accounting17. The Nature of Management Accounting18. The Behavior of Costs19. Full Costs and Their Uses20. Additional Aspects of Product Costing Systems21. Standard Costs, Variable Costing Systems, Quality Costs, and Joint Costs22. Production Cost Variances23. Analyzing Other Variances24. Control: The Management Control Environment25. Control: The Management Control Process26. Strategic Planning and Budgeting27. Reporting and Evaluation28. Short-Run Alternative Choice Decision29. Longer-Run Decisions: Capital Budgeting30. Management Accounting System Design31. Present Value of 1ReceivedNYearsHence32.PresentValueof1 Received N Years Hence32. Present Value of 1 Received Annually for N Yearsxxvi, 975 hlm. ; 26 cm

    Lithium and Lithium Depletion in Halo Stars on Extreme Orbits

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    We have determined Li abundances in 55 metal-poor (3.6 < [Fe/H] < -0.7) stars with extreme orbital kinematics. We find the Li abundance in the Li-plateau stars and examine its decrease in low-temperature, low-mass stars. The Li observations are primarily from the Keck I telescope with HIRES (spectral resolution of ~48,000 and median signal-to-noise per pixel of 140). Abundances or upper limits were determined for Li for all the stars with typical errors of 0.06 dex. Our 14 stars on the Li plateau give A(Li) = log N(Li)/N(H) + 12.00 of 2.215 +-0.110, consistent with earlier results. We find a dependence of the Li abundance on metallicity as measured by [Fe/H] and the Fe-peak elements [Cr/H] and [Ni/H], with a slope of ~0.18. We also find dependences of A(Li) with the alpha elements, Mg, Ca, and Ti. For the n-capture element, Ba, the relation between A(Li) and [Ba/H] has a shallower slope of 0.13; over a range of 2.6 dex in [Ba/H], the Li abundance spans only a factor of two. We examined the possible trends of A(Li) with the characteristics of the orbits of our halo stars, but find no relationship with kinematic or dynamic properties. The stars cooler than the Li plateau are separated into three metallicity subsets. The decrease in A(Li) sets in at hotter temperatures at high metallicities than at low metallicities; this is in the opposite sense of the predictions for Li depletion from standard and non-standard models.Comment: 29 pages including 3 tables and 12 figures Accepted by The Astrophysical Journal, for the 1 November 2005 issue, v. 63

    Rhythmic tapping to a moving beat motion kinematics overrules natural gravity

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    beat induction is the cognitive ability that allows humans to listen to a regular pulse in music and move in synchrony with it. although auditory rhythmic cues induce more consistent synchronization than flashing visual metronomes, this auditory-visual asymmetry can be canceled by visual moving stimuli. here, we investigated whether the naturalness of visual motion or its kinematics could provide a synchronization advantage over flashing metronomes. Subjects were asked to tap in sync with visual metronomes defined by vertically accelerating/decelerating motion, either congruent or not with natural gravity; horizontally accelerating/decelerating motion; or flashing stimuli. we found that motion kinematics was the predominant factor determining rhythm synchronization, as accelerating moving metronomes in any cardinal direction produced more precise and predictive tapping than decelerating or flashing conditions. our results support the notion that accelerating visual metronomes convey a strong sense of beat, as seen in the cueing movements of an orchestra director

    Regarding “is there an increased risk for DVT with the VNUS closure procedure?”

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    Genetic control of resistance to gastro-intestinal parasites in crossbred cashmere-producing goats: responses to selection, genetic parameters and relationships with production traits

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    AbstractThis paper investigates the genetic control of the resistance of goats to nematode parasites, and relationships between resistance and production traits. The data set comprised faecal egg counts (FECs) measured on 830 naturally challenged (predominant species Teladorsagia circumcincta), crossbred cashmere-producing goats over 5 years (1993-1997) and production traits (fibre traits and live weight) on 3100 goats from the same population in Scotland, over 11 years (1987-1997). Egg counts comprised repeated measurements (4 to 11) taken at 12 to 18 months of age and production traits, i.e. live weight and fibre traits, were measured at approximately 5 months of age. The goats for which FECs were available were subdivided into a line selected for decreased FECs, using the geometric mean FEC across the measurement period and goats not selected on the basis of FECs, acting as controls. The selected line had significantly lower FECs, compared with the control, in 4 out of 5 years (back transformed average proportional difference of 0·23). The heritability of a single FEC measurement (after cubic root transformation) was 0·17 and the heritability of the mean FEC was 0·32. The heritabilities of the fibre traits were moderate to high with the majority in excess of 0·5. The heritability of live weight was 0·22. Genetic correlations between FECs and production traits were slightly positive but not significantly different from zero. Phenotypic and environmental correlations were very close to zero with the environmental correlations always being negative. It is concluded that selection for reduced FEC is possible for goats. Benefits of such selection will be seen when animals are kept for more than 1 year of productive life.</jats:p
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