The influence of modified gravitational fields on motions of Keplerian objects at the far-edge of the Solar System

We investigated the impact of three different modifications of Newtonian gravity on motions of Keplerian objects within the Solar System. These objects are located at distances of the order of the distance to the Oort cloud. With these three modifications we took into account a heliocentric Dark-Matter halo as was indicated by Diemand et al, Modified Newtonian Dynamics (MOND) and a vacuum-induced force due to a locally negative cosmological constant $\Lambda_-$ derived by Fahr & Siewert. In gravitationally bound systems it turns out that all three modifications deliver the same qualitative results: Initially circular orbits for the pure Newtonian case are forced to convert into ellipses with perihelion migrations. The quantitative consideration, however, of the orbital parameters showed strong differences between MOND on the one side, and Dark-Matter and $\Lambda_-$ effects on the other side.Comment: 9 pages, 16 figures, MNRAS accepte

Cosmological test of the Yilmaz theory of gravity

We test the Yilmaz theory of gravitation by working out the corresponding Friedmann-type equations generated by assuming the Friedmann-Robertson-Walker cosmological metrics. In the case that space is flat the theory is consistent only with either a completely empty universe or a negative energy vacuum that decays to produce a constant density of matter. In both cases the total energy remains zero at all times, and in the latter case the acceleration of the expansion is always negative. To obtain a more flexible and potentially more realistic cosmology, the equation of state relating the pressure and energy density of the matter creation process must be different from the vacuum, as for example is the case in the steady-state models of Gold, Bondi, Hoyle and others. The theory does not support the cosmological principle for curved space K =/= 0 cosmological metrics

Evaluation of the Cunningham Panel™ in pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS) and pediatric acute-onset neuropsychiatric syndrome (PANS): Changes in antineuronal antibody titers parallel changes in patient symptoms

Comparison of pre- and post-treatment status revealed that the Cunningham Panel results correlated with changes in patient's neuropsychiatric symptoms. Based upon the change in the number of positive tests, the overall accuracy was 86%, the sensitivity and specificity were 88% and 83% respectively, and the Area Under the Curve (AUC) was 93.4%. When evaluated by changes in autoantibody levels, we observed an overall accuracy of 90%, a sensitivity of 88%, a specificity of 92% and an AUC of 95.7%. Assay reproducibility for the calcium/calmodulin-dependent protein kinase II (CaMKII) revealed a correlation coefficient of 0.90 (p < 1.67 × 10-6) and the ELISA assays demonstrated test-retest reproducibility comparable with other ELISA assays.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Pop-up Depth Views for Improving 3D Target Acquisition

Session 3: Target Acquisition & Interaction - Proceedings ISBN: 978-1-4503-0693-5International audienceWe present the design and experimental evaluation of pop-up depth views, a novel interaction technique for aiding in the placement or positioning of a 3D cursor or object. Previous work found that in a 3D placement task, a 2D mouse used with multiple orthographic views outperformed a 3D input device used with a perspective view with stereo. This was the case, even though the mouse required two clicks to complete the task instead of only the single click required with the 3D input device. We improve performance with 3D input devices with pop-up depth views, small inset views in a perspective display of the scene. These provide top- and side-views of the immediate 3D neighborhood of the cursor, thereby allowing the user to see more easily along the depth dimension, improving the user's effective depth acuity. In turn, positioning with the 3D input device is also improved. Furthermore, because the depth views are displayed near the 3D cursor, only tiny eye movements are required for the user to perceive the 3D cursor's depth with respect to nearby objects. Pop-up depth views are a kind of depth view, only displayed when the user's cursor slows down. In this manner, they do not occlude the 3D scene when the user is moving quickly. Our experimental evaluation shows that the combination of a 3D input device used with a perspective view, stereo projection, and pop-up depth views, outperforms a 2D mouse in a 3D target acquisition task, in terms of both movement time and throughput, but at the cost of a slightly higher error rate

A Framework for 3D Visualisation and Manipulation in an Immersive Space using an Untethered Bimanual Gestural Interface

Immersive Environments (IE) offer users the experience of being submerged in a virtual space, effectively transcending the boundary between the real and virtual world. We present a framework for visualization and manipulation of 3D virtual environments in which users need not resort to the awkward command vocabulary of traditional keyboard-and-mouse interaction. We have adapted the transparent toolglass paradigm as a gestural interface widget for a spatially immersive environment. To serve that purpose, we have implemented a bimanual gestural interpreter and parser to recognize and translate a user’s actions into commands for the toolglasses. In order to satisfy a primary design goal of keeping the user completely untethered, we use purely video-based tracking techniques

The Statistical Adversary Allows Optimal Money-Making Trading Strategies (Extended Abstract)

Andrew Chou Jeremy Cooperstock y Ran El--Yaniv z Michael Klugerman x Tom Leighton -- November, 1993 Abstract The distributional approach and competitive analysis have traditionally been used for the design and analysis of on-line algorithms. The former assumes a specific distribution on inputs, while the latter assumes inputs are chosen by an unrestricted adversary. This paper employs the statistical adversary (recently proposed by Raghavan) to analyze and design on-line algorithms for two-way currency trading. The statistical adversary approach may be viewed as a hybrid of the distributional approach and competitive analysis. By statistical adversary, we mean an adversary that generates input sequences, where each sequence must satisfy certain general statistical properties. The on-line algorithms presented in this paper have some very attractive properties. For instance, the algorithms are money-making; they are guaranteed to be profitable when the optimal off-li..

Deploying wearable sensors for pandemic mitigation: A counterfactual modelling study of Canada's second COVID-19 wave.

Wearable sensors can continuously and passively detect potential respiratory infections before or absent symptoms. However, the population-level impact of deploying these devices during pandemics is unclear. We built a compartmental model of Canada's second COVID-19 wave and simulated wearable sensor deployment scenarios, systematically varying detection algorithm accuracy, uptake, and adherence. With current detection algorithms and 4% uptake, we observed a 16% reduction in the second wave burden of infection; however, 22% of this reduction was attributed to incorrectly quarantining uninfected device users. Improving detection specificity and offering confirmatory rapid tests each minimized unnecessary quarantines and lab-based tests. With a sufficiently low false positive rate, increasing uptake and adherence became effective strategies for scaling averted infections. We concluded that wearable sensors capable of detecting presymptomatic or asymptomatic infections have potential to help reduce the burden of infection during a pandemic; in the case of COVID-19, technology improvements or supporting measures are required to keep social and resource costs sustainable