514 research outputs found
Impressions of force in visual perception of collision events: A test of the causal asymmetry hypothesis
Theory of terahertz electric oscillations by supercooled superconductors
We predict that below T_c a regime of negative differential conductivity
(NDC) can be reached. The superconductor should be supercooled to T<T_c in the
normal phase under DC voltage. In such a nonequilibrium situation the NDC of
the superconductor is created by the excess conductivity of the fluctuation
Cooper pairs. We propose NDC of supercooled superconductors to be used as an
active medium for generation of electric oscillations. Such generators can be
used in the superconducting electronics as a new type THz source of radiation.
Oscillations can be modulated by the change of the bias voltage, electrostatic
doping by a gate electrode when the superconductor is the channel of a field
effect transistor, or by light. When small amplitude oscillations are
stabilized near the critical temperature T_c the generator can be used as a
bolometer. The essential for the applications NDC is predicted by the solution
of the Boltzmann kinetic equation for the metastable in the normal phase Cooper
pairs. Boltzmann equation for fluctuation Cooper pairs is a result of
state-of-the-art application of the microscopic theory of superconductivity.
Our theoretical conclusions are based on some approximations like time
dependent Ginzburg-Landau theory, but nevertheless can reliably predict
appearance of NDC. The maximal frequency at which superconductors can operate
as generators is determined by the critical temperature \hbar omega_max ~ k_B
T_c. For high-T_c superconductors this maximal frequency falls well inside the
terahertz range. Technical conditions to avoid nucleation of the
superconducting phase are briefly discussed. We suggest that nanostructured
high-T_c superconductors patterned in a single chip can give the best technical
performance of the proposed oscillator.Comment: 7 page
Causality in collective filtering
In this paper, we describe a proposal for improving the practice of web-based collective filtering, in particular for what regards discussions and selection of issues about policy, based on the intuitive concept of causality. Causality, especially when presented in visual form, is especially suited to the task since it is intuitive to understand and to use, and at the same time, it's rich enough to create a semantic network between the representations of real world facts. We give some examples of the suggested system workflow and we present guidelines for its implementation
An Observational Study of the First Experience with Bevacizumab for the Treatment of Patients with Recurrent High-Grade Glioma in Two Belgian University Hospitals
Background. Bevacizumab (BEV), a humanized immunoglobulin G1 monoclonal antibody that inhibits VEGF has demonstrated activity against recurrent high-grade gliomas (HGG) in phase II clinical trials. Patients and Methods. Data were collected from patients with recurrent HGG who initiated treatment with BEV outside a clinical trial protocol at two Belgian university hospitals. Results. 19 patients (11 M/8 F) were administered a total of 138 cycles of BEV (median 4, range 1–31). Tumor response assessment by MRI was available for 15 patients; 2 complete responses and 3 partial responses for an objective response rate of 26% for the intent to treat population were observed on gadolinium-enhanced T1-weighted images; significant regressions on T2/FLAIR were documented in 10 out of 15 patients (67%). A reduced uptake on PET was documented in 3 out of 4 evaluable patients. The six-month progression-free survival was 21% (95% CI 2.7–39.5). Two patients had an ongoing tumor response and remained free from progression after 12 months of BEV treatment. Conclusions. The activity and tolerability of BEV were comparable to results from previous prospective phase II trials. Reduced uptake on PET suggests a metabolic response in addition to an antiangiogenic effect in some cases with favorable clinical outcome
Immanent Justice Reasoning by Spatial Proximity
Immanent justice reasoning involves causally attributing someone’s bad outcome to their prior immoral actions. Building on the idea that causality is mentally linked with spatial proximity, we investigated whether such reasoning might lead participants to spatially bind together immoral actions and bad outcomes. Across 4 experiments (N = 553 Mechanical Turk workers), participants positioned sentences describing other people’s bad (vs. good) outcomes closer in space to previous immoral behaviours. This effect was observed both when the position of the initial action remained in a fixed location and when it “chased” the outcome across the screen. Importantly, we also found that this spatial positioning of immoral actions and bad outcomes is mediated by perceived deservingness of the outcome and is not merely due to perceived similarity of events. These findings suggest that perceived deservingness biases the spatial proximity of representations of others’ random bad outcomes and their prior immoral actions
The Renormalization Effects in the Microstrip-SQUID Amplifier
The peculiarities of the microstrip-DC SQUID amplifier caused by the resonant
structure of the input circuit are analyzed. It is shown that the mutual
inductance, that couples the input circuit and the SQUID loop, depends on the
frequency of electromagnetic field. The renormalization of the SQUID parameters
due to the screening effect of the input circuit vanishes when the Josephson
frequency is much greater than the signal frequency.Comment: 11 pages, 2 figure
Animated Edge Textures in Node-Link Diagrams: a Design Space and Initial Evaluation
International audienceNetwork edge data attributes are usually encoded using color, opacity, stroke thickness and stroke pattern, or some combination thereof. In addition to these static variables, it is also possible to animate dynamic particles flowing along the edges. This opens a larger design space of animated edge textures, featuring additional visual encodings that have potential not only in terms of visual mapping capacity but also playfulness and aesthetics. Such animated edge textures have been used in several commercial and design-oriented visualizations, but to our knowledge almost always in a relatively ad hoc manner. We introduce a design space and Web-based framework for generating animated edge textures, and report on an initial evaluation of particle properties – particle speed, pattern and frequency – in terms of visual perception
Mind the Gap: Investigating Toddlers’ Sensitivity to Contact Relations in Predictive Events
Toddlers readily learn predictive relations between events (e.g., that event A predicts event B). However, they intervene on A to try to cause B only in a few contexts: When a dispositional agent initiates the event or when the event is described with causal language. The current studies look at whether toddlers’ failures are due merely to the difficulty of initiating interventions or to more general constraints on the kinds of events they represent as causal. Toddlers saw a block slide towards a base, but an occluder prevented them from seeing whether the block contacted the base; after the block disappeared behind the occluder, a toy connected to the base did or did not activate. We hypothesized that if toddlers construed the events as causal, they would be sensitive to the contact relations between the participants in the predictive event. In Experiment 1, the block either moved spontaneously (no dispositional agent) or emerged already in motion (a dispositional agent was potentially present). Toddlers were sensitive to the contact relations only when a dispositional agent was potentially present. Experiment 2 confirmed that toddlers inferred a hidden agent was present when the block emerged in motion. In Experiment 3, the block moved spontaneously, but the events were described either with non-causal (“here’s my block”) or causal (“the block can make it go”) language. Toddlers were sensitive to the contact relations only when given causal language. These findings suggest that dispositional agency and causal language facilitate toddlers’ ability to represent causal relationships.John Templeton Foundation (#12667)James S. McDonnell Foundation (Causal Learning Collaborative Initiative)National Science Foundation (U.S.) (Career Award (# 0744213
Modeling and Simulation of a Microstrip-SQUID Amplifier
Using a simple lumped-circuit model, we numerically study the dependence of
the voltage gain and noise on the amplifier's parameters. Linear, quasi-linear,
and nonlinear regimes are studied. We have shown that the voltage gain of the
amplifier cannot exceed a characteristic critical value, which decreases with
the increase of the input power. We have also shown that the spectrum of the
voltage gain depends significantly on the level of the Johnson noise generated
by the SQUID resistors.Comment: 13 page
- …