Transition times and stochastic resonance for multidimensional diffusions with time periodic drift: A large deviations approach

We consider potential type dynamical systems in finite dimensions with two meta-stable states. They are subject to two sources of perturbation: a slow external periodic perturbation of period $T$ and a small Gaussian random perturbation of intensity $\epsilon$, and, therefore, are mathematically described as weakly time inhomogeneous diffusion processes. A system is in stochastic resonance, provided the small noisy perturbation is tuned in such a way that its random trajectories follow the exterior periodic motion in an optimal fashion, that is, for some optimal intensity $\epsilon (T)$. The physicists' favorite, measures of quality of periodic tuning--and thus stochastic resonance--such as spectral power amplification or signal-to-noise ratio, have proven to be defective. They are not robust w.r.t. effective model reduction, that is, for the passage to a simplified finite state Markov chain model reducing the dynamics to a pure jumping between the meta-stable states of the original system. An entirely probabilistic notion of stochastic resonance based on the transition dynamics between the domains of attraction of the meta-stable states--and thus failing to suffer from this robustness defect--was proposed before in the context of one-dimensional diffusions. It is investigated for higher-dimensional systems here, by using extensions and refinements of the Freidlin--Wentzell theory of large deviations for time homogeneous diffusions. Large deviations principles developed for weakly time inhomogeneous diffusions prove to be key tools for a treatment of the problem of diffusion exit from a domain and thus for the approach of stochastic resonance via transition probabilities between meta-stable sets.Comment: Published at http://dx.doi.org/10.1214/105051606000000385 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

International expert consensus on electronic nicotine delivery systems and heated tobacco products: a Delphi survey.

To provide a consensus from a panel of international experts about electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP). Cross-sectional survey. A Delphi survey was conducted among international experts in tobacco control and smoking cessation. The first part addressed statements or recommendations about ENDS, the second about HTP, both divided into four categories: regulation, sale, use and general issues. Experts from 15 countries. Individuals with clinical, public health or research expertise in tobacco control and/or smoking cessation. 268 experts were contacted, 92 (34%) completed the first, 55/92 (60%) the second round. Consensus for ENDS: components of e-liquids, an upper limit of nicotine concentration should be defined; a warning on the lack of evidence in long-term safety and addiction potential should be stated; ENDS should not be regulated as consumer products but either as a new category of nicotine delivery or tobacco products; ENDS should not be sold in general stores but in specialised shops, shops selling tobacco or in pharmacies with restriction on sale to minors; administration of illegal drugs is likely with ENDS. Consensus for HTP: HTP have the same addictive potential as cigarettes; they should be regulated as a tobacco product with similar warning messages as cigarettes; their advertisement should not be allowed. ENDS and HTP use should not be allowed in indoor public places; a specific tax should be implemented for ENDS, taxes on HTP should not be lower than those for cigarettes; use of cigarettes is more likely with both ENDS and HTP (dual use) than quitting smoking. Experts in tobacco control and/or smoking cessation recommend differential regulation for ENDS and HTP. The results of this survey may be useful for health authorities, decision makers and researchers of the tobacco use and cessation field

Model Pembelajaran Kooperatif Tipe Stad (Student Teams Achievement Division) Dikombinasikan dengan Media Animasi pada Materi Laju Reaksi Kelas XI SMA Negeri 1 Palu

Students have difficulties in understanding chemistry subject contained mathematical calculation like on reaction rate topic. Cooperative learning model STAD type can be an alternative for the material contained calculation whereas animation media is for conceptual understanding. The objective of the research was to determine the influence of cooperative learning model STAD type combined with animation media for the eleventh grade students of SMA Negeri 1 Palu in academic year 2012/2013 toward the students' learning outcome on reaction rate material. This research was quasy experimental using posttest-only control group design. The population was the whole eleventh grade students of science program with the sample determination using purposive sampling method. The sample were class of science program 2 as the experimental class which using cooperative learning model STAD type with animation media whereas class of science program 4 as the control one which using convensional learning method. The research results showed that cooperative learning model STAD type combined with animation media at reaction rate material gave students' learning outcome higher than convensional method

Arendt and political realism: towards a realist account of political judgement

This article argues that Hannah Arendt’s thought can offer significant insights on political judgement for realism in political theory. We identify a realist position which emphasises the need to account for how humans judge politically, contra moralist tendencies to limit its exercise to rational standards, but which fails to provide a sufficient conception of its structure and potential. Limited appeals to political judgement render the realist defence of the political elusive, and compromise the endeavour to offer a meaningful alternative to the moralist tendency to displace politics. The potential and limitations of realist discussions on judgement are made visible in relation to proto-realists Judith Shklar and Isaiah Berlin. In seeking to enrich the realist conception of the political, the article introduces the displacement critique found in the neglected Arendtian ‘realism’. It also provides the foundations for a distinctly realist account of political judgement which, we argue, requires elaboration along two dimensions: the social coding of political judgement and the political capacities that help judgement build a suitable political sphere

Dispersive diffusion controlled distance dependent recombination in amorphous semiconductors

The photoluminescence in amorphous semiconductors decays according to power law $t^{-delta}$ at long times. The photoluminescence is controlled by dispersive transport of electrons. The latter is usually characterized by the power $alpha$ of the transient current observed in the time-of-flight experiments. Geminate recombination occurs by radiative tunneling which has a distance dependence. In this paper, we formulate ways to calculate reaction rates and survival probabilities in the case carriers execute dispersive diffusion with long-range reactivity. The method is applied to obtain tunneling recombination rates under dispersive diffusion. The theoretical condition of observing the relation $delta = alpha/2 + 1$ is obtained and theoretical recombination rates are compared to the kinetics of observed photoluminescence decay in the whole time range measured.Comment: To appear in Journal of Chemical Physic

Bernard Suits on capacities: games, perfectionism, and Utopia

An essential and yet often neglected motivation of Bernard Suits’ elevation of gameplay to the ideal of human existence is his account of capacities along perfectionist lines and the function of games in eliciting them. In his work Suits treats the expression of these capacities as implicitly good and the purest expression of the human telos. Although it is a possible interpretation to take Suits’ utopian vision to mean that gameplay in his future utopia must consist of the logically inevitable replaying of activities we conduct in the present for instrumental reasons (playing games-by-default), because gameplay for Suits is identical with the expression of sets of capacities specifically elicited by game rules, it is much more likely that he intends utopian gameplay to be an endless series of carefully crafted opportunities for the elicitation of special capacities (playing games-by-design), and thus embody his ideal of existence. This article therefore provides a new lens for understanding both Suits’ definitional work on gameplay and its connection to his utopian vision in the last chapter of The Grasshopper: Games, Life, and Utopia

Ubiquitin-based probes prepared by total synthesis to profile the activity of deubiquitinating enzymes

Epitope-tagged active-site-directed probes are widely used to visualize the activity of deubiquitinases (DUBs) in cell extracts, to investigate the specificity and potency of small-molecule DUB inhibitors, and to isolate and identify DUBs by mass spectrometry. With DUBs arising as novel potential drug targets, probes are required that can be produced in sufficient amounts and to meet the specific needs of a given experiment. The established method for the generation of DUB probes makes use of labor-intensive intein-based methods that have inherent limitations concerning the incorporation of unnatural amino acids and the amount of material that can be obtained. Here, we describe the total chemical synthesis of active-site-directed probes and their application to activity-based profiling and identification of functional DUBs. This synthetic methodology allowed the easy incorporation of desired tags for specific applications, for example, fluorescent reporters, handles for immunoprecipitation or affinity pull-down, and cleavable linkers. Additionally, the synthetic method can be scaled up to provide significant amounts of probe. Fluorescent ubiquitin probes allowed faster, in-gel detection of active DUBs, as compared to (immuno)blotting procedures. A biotinylated probe holding a photocleavable linker enabled the affinity pull-down and subsequent mild, photorelease of DUBs. Also, DUB activity levels were monitored in response to overexpression or knockdown, and to inhibition by small molecules. Furthermore, fluorescent probes revealed differential DUB activity profiles in a panel of lung and prostate cancer cells

Sensitivity (Se) and Specificity (Sp) Anthropometric Wall Chart (Awc) Tb/U for Detecting Stunting on Children Aged 6-12 Years

Anthropometric Wall Chart (AWC) TB/U is a tool developed to screen nutritional status that is easy and fast to use for children aged 6-12 years in the population. The accuracy of the tool in measuring stunting can be seen from its validity. This study aims to get the validity of AWC in 3 (three) cities representing the West (Medan), Central (Bandung) and East (Kupang), Indonesia so that the results could be used for stunting screening of elementary school children wider coverage. The study was conducted in a cross-sectional manner with a sample of 270 elementary students from grade 1 to grade 6 in 3 cities (Medan, Kupang, and Bandung) whose nutritional status was measured by using AWC TB / U and TB / U index using microtoise. The results of the study of the use of AWC in Medan showed that there were 20 (22.2%) stunting children, with Se value of 68.8% and Sp value of 87.8%, PPV 55%, and NPV 92.9%. In Kupang, there were 21 (23.3%) children who were stunting with a value of Se 60.0% and Sp 98.2%, and in Bandung, there were 12 (13.3%) stunted children with Se value of 72.7% and Sp 94.9%. Combined in 3 (three) cities get Se value 66.0% and Sp 93.3%, PPV 73.6% and NPV 90.3%. AWC TB / U can be used as a stunting screening tool for diagnosis with the aim of a high Sp value. For students who are detected stunted, further treatment is needed to overcome their nutritional problems