Current relaxation in nonlinear random media

We study the current relaxation of a wave packet in a nonlinear random sample coupled to the continuum and show that the survival probability decays as $P(t) \sim 1/t^{\alpha}$. For intermediate times $t<t^*$, the exponent $\alpha$ satisfies a scaling law $\alpha =f(\Lambda=\chi/l_{\infty})$ where $\chi$ is the nonlinearity strength and $l_{\infty}$ is the localization length of the corresponding random system with $\chi=0$. For $t\gg t^*$ and $\chi>\chi_{\rm cr}$ we find a universal decay with $\alpha=2/3$ which is a signature of the {\it nonlinearity-induced delocalization}. Experimental evidence should be observable in coupled nonlinear optical waveguides.Comment: revised version, PRL in press, 4 pages, 4 figs (fig 3 with reduced quality

Tripartite Graph Clustering for Dynamic Sentiment Analysis on Social Media

The growing popularity of social media (e.g, Twitter) allows users to easily share information with each other and influence others by expressing their own sentiments on various subjects. In this work, we propose an unsupervised \emph{tri-clustering} framework, which analyzes both user-level and tweet-level sentiments through co-clustering of a tripartite graph. A compelling feature of the proposed framework is that the quality of sentiment clustering of tweets, users, and features can be mutually improved by joint clustering. We further investigate the evolution of user-level sentiments and latent feature vectors in an online framework and devise an efficient online algorithm to sequentially update the clustering of tweets, users and features with newly arrived data. The online framework not only provides better quality of both dynamic user-level and tweet-level sentiment analysis, but also improves the computational and storage efficiency. We verified the effectiveness and efficiency of the proposed approaches on the November 2012 California ballot Twitter data.Comment: A short version is in Proceeding of the 2014 ACM SIGMOD International Conference on Management of dat

Reversing conditional orderings

We analyze some specific aspects concerning conditional orderings and relations among them. To this purpose we define a suitable concept of reversed conditional ordering and prove some related results. In particular we aim to compare the univariate stochastic orderings ≤ st, ≤ hr, and ≤ lr in terms of differences among different notions of conditional orderings. Some applications of our result to the analysis of positive dependence will be detailed. We concentrate attention to the case of a pair of scalar random variables X, Y ​. Suitable extensions to multivariate cases are possible

Influence of Blood and Milk Selenium Concentration on Somatic Cell Count in Early and Mid Lactation

The aim of this study was to determine the effect of selenium concentration in blood and milk in early lactation on somatic cell count. The average selenium concentration in the blood serum was 0.62 ± 0.11 μmol/l and in the milk serum 0.61 ± 0.07 μmol/l. Optimal blood selenium concentrations were found in 19 cows and suboptimal concentrations in 11 cows. Optimal milk selenium concentration was found in 14 cows and suboptimal in 16 cows. The average milk production per cow was 23.12 ± 3.1 liters / day and the average somatic cell count in the first and sixth months of lactation was 5.34 ± 5 (log transformed) and 5.12 ± 4.9, respectively. Blood selenium concentration correlated negatively with milk somatic cell count in early and mid lactation. The classification of cows based on blood selenium concentration gave results which suggested that selenium-deficient cows had a significantly higher somatic cell count in early lactation (the first month) and mid lactation (the sixth month). Blood selenium is an important predictor of milk somatic cell count. Somatic cell count in milk is not dependent upon selenium concentration in milk or interaction blood×milk selenium. Selenium concentration is not in connection with milk production

Operationalizing anthropological theory: four techniques to simplify networks of co-occurring ethnographic codes

The use of data and algorithms in the social sciences allows for exciting progress, but also poses epistemological challenges. Operations that appear innocent and purely technical may profoundly influence final results. Researchers working with data can make their process less arbitrary and more accountable by making theoretically grounded methodological choices. We apply this approach to the problem of simplifying networks representing ethnographic corpora, in the interest of visual interpretation. Network nodes represent ethnographic codes, and their edges the co-occurrence of codes in a corpus. We introduce and discuss four techniques to simplify such networks and facilitate visual analysis. We show how the mathematical characteristics of each one are aligned with an identifiable approach in sociology or anthropology: structuralism and post-structuralism; identifying the central concepts in a discourse; and discovering hegemonic and counter-hegemonic clusters of meaning. We then provide an example of how the four techniques complement each other in ethnographic analysis

An alternative approach for the dynamics of polarons in one dimension

We developed a new method based on functional integration to treat the dynamics of polarons in one-dimensional systems. We treat the acoustical and the optical case in an unified manner, showing their differences and similarities. The mobility and diffusion coefficients are calculated in the Markovian approximation in the strong coupling limit.Comment: 57 page

A spinor approach to Walker geometry

A four-dimensional Walker geometry is a four-dimensional manifold M with a neutral metric g and a parallel distribution of totally null two-planes. This distribution has a natural characterization as a projective spinor field subject to a certain constraint. Spinors therefore provide a natural tool for studying Walker geometry, which we exploit to draw together several themes in recent explicit studies of Walker geometry and in other work of Dunajski (2002) and Plebanski (1975) in which Walker geometry is implicit. In addition to studying local Walker geometry, we address a global question raised by the use of spinors.Comment: 41 pages. Typos which persisted into published version corrected, notably at (2.15

Development of a nurse home visitation intervention for intimate partner violence

Background: Despite an increase in knowledge about the epidemiology of intimate partner violence (IPV), much less is known about interventions to reduce IPV and its associated impairment. One program that holds promise in preventing IPV and improving outcomes for women exposed to violence is the Nurse-Family Partnership (NFP), an evidence-based nurse home visitation program for socially disadvantaged first-time mothers. The present study developed an intervention model and modification process to address IPV within the context of the NFP. This included determining the extent to which the NFP curriculum addressed the needs of women at risk for IPV or its recurrence, along with client, nurse and broader stakeholder perspectives on how best to help NFP clients cope with abusive relationships. Methods. Following a preliminary needs assessment, an exploratory multiple case study was conducted to identify the core components of the proposed IPV intervention. This included qualitative interviews with purposeful samples of NFP clients and community stakeholders, and focus groups with nurse home visitors recruited from four NFP sites. Conventional content analysis and constant comparison guided data coding and synthesis. A process for developing complex interventions was then implemented. Results: Based on data from 69 respondents, an IPV intervention was developed that focused on identifying and responding to IPV; assessing a client\u27s level of safety risk associated with IPV; understanding the process of leaving and resolving an abusive relationship and system navigation. A need was identified for the intervention to include both universal elements of healthy relationships and those tailored to a woman\u27s specific level of readiness to promote change within her life. A clinical pathway guides nurses through the intervention, with a set of facilitators and corresponding instructions for each component. Conclusions: NFP clients, nurses and stakeholders identified the need for modifications to the existing NFP program; this led to the development of an intervention that includes universal and targeted components to assist NFP nurses in addressing IPV with their clients. Plans for feasibility testing and evaluation of the effectiveness of the IPV intervention embedded within the NFP, and compared to NFP-only, are discussed. © 2012 Jack et al; licensee BioMed Central Ltd

Эндометриоз под маской рака мочевого пузыря (обзор литературы и описание трех собственных наблюдений)

The authors consider the prevalence, etiology, pathogenesis, symptoms, diagnosis, differential diagnosis, and surgical treatment of bladder endometriosis on the basis of 3 own cases and an analysis of 384 cases described in world literature. It has been established that endometriosis may mimic bladder carcinoma. The detection of the cyclic pattern of gross hematuria and other symptoms (during menstruation) and that of the characteristic type of tumorous endrometrioid mass at cystoscopy performed during or just prior to menstruation are of key importance for the differential diagnosis of endometriosis and carcinoma. Indications for open resection of the bladder, transurethral resection, and minimally invasive laparoscopic surgery are determined.Рассмотрены распространенность, этиология, патогенез, симптоматика, диагностика, дифференциальная диагностика и оперативное лечение эндометриоза мочевого пузыря на основе 3 собственных наблюдений и анализа 384 случаев, описанных в мировой литературе. Установлено, что эндометриоз нередко может протекать под маской рака мочевого пузыря. В дифференциальной диагностике эндометриоза от рака главное значение имеют выявление циклического характера макрогематурии и других симптомов (сопутствующих менструации), обнаружение характерных признаков опухолевидного эндометриоидного образования при цистоскопии, выполненной во время менструации или непосредственно перед ней. Определены показания к открытой резекции мочевого пузыря, ТУР и мини-инвазивной лапароскопической операции