Rana palustris

Number of Pages: 3Integrative BiologyGeological Science

Influence of Hydrodynamic Interactions on the Kinetics of Colloidal Particle's Adsorption

The kinetics of irreversible adsorption of spherical particles onto a flat surface is theoretically studied. Previous models, in which hydrodynamic interactions were disregarded, predicted a power-law behavior $t^{-2/3}$ for the time dependence of the coverage of the surface near saturation. Experiments, however, are in agreement with a power-law behavior of the form $t^{-1/2}$. We outline that, when hydrodynamic interactions are considered, the assymptotic behavior is found to be compatible with the experimental results in a wide region near saturation.Comment: 4 pages, 1 figures, Phys. Rev. Lett. (in press

Adaptive end-to-end optimization of mobile video streaming using QoS negotiation

Video streaming over wireless links is a non-trivial problem due to the large and frequent changes in the quality of the underlying radio channel combined with latency constraints. We believe that every layer in a mobile system must be prepared to adapt its behavior to its environment. Thus layers must be capable of operating in multiple modes; each mode will show a different quality and resource usage. Selecting the right mode of operation requires exchange of information between interacting layers. For example, selecting the best channel coding requires information about the quality of the channel (capacity, bit-error-rate) as well as the requirements (latency, reliability) of the compressed video stream generated by the source encoder. In this paper we study the application of our generic QoS negotiation scheme to a specific configuration for mobile video transmission. We describe the results of experiments studying the overall effectiveness, stability, and dynamics of adaptation of our distributed optimization approach

How much do you want to learn? High-school students' willingness to invest effort in valenced feedback-learning tasks

High-school students decide in which tasks to invest their cognitive effort on a daily basis. At school, such decisions often relate to feedback-learning situations (e.g., whether or not to do homework exercises). To investigate how willing high-school students are to invest their cognitive effort in such situations, we administered in this preregistered study a feedback-learning task in combination with a cognitive effort-discounting task – a paradigm to quantify willingness to invest effort. We did so to a large sample (N = 195) from average educational backgrounds in an ecologically valid setting (a school class). We specifically tested whether high-school students discounted their effort in feedback-learning tasks, which proved to be the case, and whether this discounting was differentially affected by positive and negative feedback, which proved not to be the case. We also found that learning was unaffected by feedback valence, except that students learned better from positive than from negative feedback when high effort was required. These results imply that in a school setting, where feedback learning is common, high-school students are less willing to invest cognitive effort in more effortful tasks irrespective of feedback valence, and that positive feedback can aid learning when high effort is required. We provide several recommendations as to how our proposed combination of feedback learning and effort discounting could be used to understand and improve students' academic motivation. Educational relevance statement: High school students sometimes struggle with motivation for learning, at least partly because of low willingness to invest their effort. By investigating high-school students' willingness to invest effort for learning within an educational context, we aim to enhance understanding of this decision-making process in high-school students. Our results indicate that in a school setting, where feedback learning is common, high-school students are less willing to invest cognitive effort in more effortful tasks irrespective of whether they receive positive or negative feedback, but that positive feedback can aid learning when learning tasks require high effort. These results imply that positive feedback may reduce the costs of learning or increase its benefits for difficult tasks.</p

Mechanism Design in Social Networks

This paper studies an auction design problem for a seller to sell a commodity in a social network, where each individual (the seller or a buyer) can only communicate with her neighbors. The challenge to the seller is to design a mechanism to incentivize the buyers, who are aware of the auction, to further propagate the information to their neighbors so that more buyers will participate in the auction and hence, the seller will be able to make a higher revenue. We propose a novel auction mechanism, called information diffusion mechanism (IDM), which incentivizes the buyers to not only truthfully report their valuations on the commodity to the seller, but also further propagate the auction information to all their neighbors. In comparison, the direct extension of the well-known Vickrey-Clarke-Groves (VCG) mechanism in social networks can also incentivize the information diffusion, but it will decrease the seller's revenue or even lead to a deficit sometimes. The formalization of the problem has not yet been addressed in the literature of mechanism design and our solution is very significant in the presence of large-scale online social networks.Comment: In The Thirty-First AAAI Conference on Artificial Intelligence, San Francisco, US, 04-09 Feb 201

Occupational therapy and sensory integration for children with autism: a feasibility, safety, acceptability and fidelity study.

Objective: To examine the feasibility, safety, and acceptability of a manualized protocol of occupational therapy using sensory integration principles for children with autism. Methods: Ten children diagnosed with autism spectrum disorder ages 4-8 years received intensive occupational therapy intervention using sensory integration principles following a manualized protocol. Measures of feasibility, acceptability and safety were collected from parents and interveners, and fidelity was measured using a valid and reliable fidelity instrument. Results: The intervention is safe and feasible to implement, acceptable to parents and therapist, and therapists were able to implement protocol with adequate fidelity. These data provide support for implementation of a randomized control trial of this intervention and identify specific procedural enhancements to improve study implementation

Cross-cultural comparison of sensory behaviors in children with autism.

Parents of children with autism frequently report that their children exhibit unusual responses to sensory experiences. Little research is available, however, describing how parents\u27 and children\u27s culture and environment might influence parents\u27 reports of their children\u27s behaviors. This study compared the frequency of parent-reported responses to sensory experiences in children from two countries-Israel and the United States. We administered the Short Sensory Profile to primary caregivers of children with autism spectrum disorders (ASD) and typically developing peers. Results indicate that Israeli parents reported unusual responses to sensory experiences less frequently than U.S. parents for both ASD and typically developing children. U.S. children with ASD demonstrated significantly greater difficulty in the Auditory Filtering and Visual/Auditory Sensitivity domains than Israeli children with ASD. These findings indicate a need to further explore the influence of culture and environment on caregiver perceptions of the responses to sensory experiences of children with ASD

Basis States for Relativistic, Dynamically-Entangled Particles

In several recent papers on entanglement in relativistic quantum systems and relativistic Bell's inequalities, relativistic Bell-type two-particle states have been constructed in analogy to non-relativistic states. These constructions do not have the form suggested by relativistic invariance of the dynamics. Two relativistic formulations of Bell-type states are shown for massive particles, one using the standard Wigner spin basis and one using the helicity basis. The construction hinges on the use of Clebsch-Gordan coefficients of the Poincar\'e group to reduce the direct product of two unitary irreducible representations (UIRs) into a direct sum of UIRs.Comment: 19 pages, three tables, revte