Random Sorting Networks

A sorting network is a shortest path from 12...n to n...21 in the Cayley graph of S_n generated by nearest-neighbour swaps. We prove that for a uniform random sorting network, as n->infinity the space-time process of swaps converges to the product of semicircle law and Lebesgue measure. We conjecture that the trajectories of individual particles converge to random sine curves, while the permutation matrix at half-time converges to the projected surface measure of the 2-sphere. We prove that, in the limit, the trajectories are Holder-1/2 continuous, while the support of the permutation matrix lies within a certain octagon. A key tool is a connection with random Young tableaux.Comment: 38 pages, 12 figure

The oriented swap process

Particles labelled $1,...,n$ are initially arranged in increasing order. Subsequently, each pair of neighboring particles that is currently in increasing order swaps according to a Poisson process of rate 1. We analyze the asymptotic behavior of this process as $n\to\infty$. We prove that the space--time trajectories of individual particles converge (when suitably scaled) to a certain family of random curves with two points of non-differentiability, and that the permutation matrix at a given time converges to a certain deterministic measure with absolutely continuous and singular parts. The absorbing state (where all particles are in decreasing order) is reached at time $(2+o(1))n$. The finishing times of individual particles converge to deterministic limits, with fluctuations asymptotically governed by the Tracy--Widom distribution.Comment: Published in at http://dx.doi.org/10.1214/09-AOP456 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Detección de precios anormales en importaciones de comercio exterior del sector textil en México: uso de modelos de machine learning

La teoría económica clásica indica la importancia del comercio exterior en el crecimiento y desarrollo de una nación. Adam Smith, padre de la economía, describe que el comercio internacional es un proceso donde los países que tienen ventajas absolutas en ciertos bienes marcan su especialización en dicho bien para ser comercializado a la otra nación, y por el contrario, la otra nación se especializa en otro bien, resultando que entre ambas naciones la comercialización sea eficiente, rentable y el incremento de la producción. Las importaciones de México en el sector textil han ido en aumento, siendo China (RPC) y Vietnam los países que más exportan. Debido a sus ventajas competitivas en mano de obra y materia prima barata, han provocado que en los últimos años existan más mercancías del sector textil de estos países en México. Dado a la gran cantidad de operaciones y a la relevancia del sector para México, es primordial poder identificar los precios anormales de las importaciones de este sector, ya que esto permitirá identificar posibles mercancías subvaluadas u operaciones sobrevaluadas de lavado de dinero en el comercio exterior (TBML: Trade Based Money Laundry), y con ello reducir los efectos de la evasión fiscal y de actividades criminales de lavado de dinero. En este trabajo de tesis se utilizaron cinco modelos de Machine Learning: XGBoost, Naïves Bayes, Isolation Random Forest, Logistic Regression Classifier y Artificial Neuron Network , cuyo objetivo es resolver problemas de clasificación donde se identifican aquellas operaciones con precios normales y precios anormales. El algoritmo XGBoost permitió identificar la importancia de las variables en la estimación de la anormalidad de los precios; y con Isolation Random Forest, algoritmo no supervisado, se implementó para encontrar aquellas anomalías en los precios sin ser etiquetados previamente; Naïves Bayes, Artificial Neural Network y Logistic Regression se implementaron para obtener y comparar el mejor rendimiento de las métricas. En la revisión bibliográfica no se encontró mucha información del uso de herramientas de ML para la predicción de precios anormales en el comercio exterior, autores como Zdanowicz, Pak, de Boyrie y entre otros, implementaron otras técnicas, por lo que este trabajo de tesis puede ser novedoso y pueda aportar nuevas alternativas en la detección de precios anormales en el comercio exterior

The association between disease activity and NT-proBNP in 238 patients with rheumatoid arthritis: a 10-year longitudinal study

Introduction Disease activity in patients with rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality, of which N-terminal pro-brain natriuretic peptide (NT-proBNP) is a predictor. Our objective was to examine the cross-sectional and longitudinal associations between markers of inflammation, measures of RA disease activity, medication used in the treatment of RA, and NT-proBNP levels (dependent variable). Methods Two hundred thirty-eight patients with RA of less than 4 years in duration were followed longitudinally with three comprehensive assessments of clinical and radiographic data over a 10-year period. Serum samples were frozen and later batch-analyzed for NT-proBNP levels and other biomarkers. Bivariate, multivariate, and repeated analyses were performed. Results C-reactive protein (CRP) levels at baseline were cross-sectionally associated with NT-proBNP levels after adjustment for age and gender (r 2 adjusted = 0.23; P < 0.05). At the 10-year follow-up, risk factors for cardiovascular disease were recorded. Duration of RA and CRP levels were independently associated with NT-proBNP in the final model that was adjusted for gender, age, and creatinine levels (r 2 adjusted = 0.38; P < 0.001). In the longitudinal analyses, which adjusted for age, gender, and time of follow-up, we found that repeated measures of CRP predicted NT-proBNP levels (P < 0.001). Conclusion CRP levels are linearly associated with levels of NT-proBNP in cross-sectional and longitudinal analyses of patients with RA. The independent associations of NT-proBNP levels and markers of disease activity with clinical cardiovascular endpoints need to be further investigated

The Use of 4G Android Tablets for Enhanced Patient Activation of Chronic Disease Self-Management in People with Heart Failure

Problem: The purpose of this research was to evaluate the impact of an advanced practice nurse-directed patient education approach to heart failure treatment integrating the use of an interactive 4G android tablet, will enable patients to experience enhanced patient activation and engagement in chronic disease self-management and fewer 30-day rereadmissions. Data source: This was a prospective patient randomization, multi-center quasi-experimental design study of 50 patients comparing an advanced practice nurse-directed education of disease self-management and use of a 4G android tablet (TC) group (n = 25) and routine medical management (MC) group. The study length was 12 months. Conclusions: Descriptive statistics were computed, and the intervention and control groups were compared for differences. Descriptive statistics using ANOVA was conducted to calculate for statistical significance of readmissions between the two groups at 30 days. T-tests showed that the 30-day readmissions rate was significantly lower for the tablet groups compared to the medical group at 30 days (8% and 28% respectively; P=0.010). Implications for Practice: The results support that integrating 4G android tablet technology does have a significant impact on enhancing patient activation and engagement in chronic disease self-management and correlated to reduced 30-day readmissions in people with heart failure

Social Media Exposure: Its Relationship to Contingencies of Self-Worth and Happiness of Generations X and Y Nurses

Social media or social networking sites have been widely used to get connected with familyand friends and stay up-to date with the recent news, research, and many more. The effect,however, created an impact whether it brings positive or negative result to the end users. Thisstudy was conducted to determine the relationship of social media exposure to thecontingencies of self-worth and happiness of Generations X and Y nurses. Nurses, despite thework demands, have to carry on with the responsibility of identification, analysis,interpretation and dissemination of nursing knowledge within the health care system. Theresearchers used a descriptive correlational design. A modified version of Crocker’sContingencies of Self-worth Scale, Oxford Scale of Happiness and a self-constructed socialmedia exposure questionnaire were used to measure the variables being studied. Data from125 respondents comprising of both generation X and Y respondents were analyzed andinterpreted using mean, standard deviation, Kruskal Wallis test, and Pearson correlation.Results showed that Facebook was commonly used by the respondents followed byInstagram, Twitter, and Snapchat, respectively. Facebook was used for an average of at leastone to three hours. Contingencies of self-worth and happiness were both high. Furthermore,the results showed that there is no significant relationship between social media exposure ofGeneration X and Y nurses and contingencies of self-worth and happiness. Those belongingto the Generation X are happier than Generation Y regardless of their age and gender. Thosewith low income have been found out to have low levels of happiness. The researchersrecommend that one must be matured enough before they can be allowed to engage in socialmedia exposure so that negative influences will be avoided

Flame retardancy of rigid polyurethane foams containing thermoregulating microcapsules with phosphazene-based monomers

Thermoregulating microcapsules (MC) with flame-retardant properties were used to produce polyurethane (PU) foams. Thermogravimetric analyses of the microcapsules performed under atmospheric air and nitrogen confirmed that the hexa(methacryloylethylenedioxy) cyclotriphosphazene (PNC-HEMA) monomer raised the amount of residue after exposure to high temperature, proving the formation of a thermally stable char layer. Additionally, the flame-retardant properties of the microcapsules were analyzed by micro-combustion calorimetry (MCC), and the PU foams were tested by both MCC and cone calorimetry. The total heat release and maximum heat release rate were lower for microcapsules containing the flame-retardant PNC-HEMA. The composition of the microcapsules has been proved by MCC and TGA, where the release of the encapsulated phase change material (PCM) occurred at the expected temperature. However, in PU foams, the release of PCM is shifted to higher temperatures. Accordingly, these materials can be considered as an important alternative to commonly used microcapsules containing phase PCMs, where a lower flammability is required for their future application.publishedVersio

Characterization of p38α signaling networks in cancer cells using quantitative proteomics and phosphoproteomics

p38α (encoded by MAPK14) is a protein kinase that regulates cellular responses to almost all types of environmental and intracellular stresses. Upon activation, p38α phosphorylates many substrates both in the cytoplasm and nucleus, allowing this pathway to regulate a wide variety of cellular processes. While the role of p38α in the stress response has been widely investigated, its implication in cell homeostasis is less understood. To investigate the signaling networks regulated by p38α in proliferating cancer cells, we performed quantitative proteomic and phosphoproteomic analyses in breast cancer cells in which this pathway had been either genetically targeted or chemically inhibited. Our study identified with high confidence 35 proteins and 82 phosphoproteins (114 phosphosites) that are modulated by p38α, and highlighted the implication of various protein kinases, including MK2 and mTOR, in the p38α-regulated signaling networks. Moreover, functional analyses revealed an important contribution of p38α to the regulation of cell adhesion, DNA replication and RNA metabolism. Indeed, we provide experimental evidence supporting that p38α facilitates cancer cell adhesion, and showed that this p38α function is likely mediated by the modulation of the adaptor protein ArgBP2. Collectively, our results illustrate the complexity of the p38α regulated signaling networks, provide valuable information on p38α-dependent phosphorylation events in cancer cells, and document a mechanism by which p38α can regulate cell adhesion.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved

Network dynamics in nanofilled polymers

It is well accepted that adding nanoparticles (NPs) to polymer melts can result in significant property improvements. Here we focus on the causes of mechanical reinforcement and present rheological measurements on favourably interacting mixtures of spherical silica NPs and poly(2-vinylpyridine), complemented by several dynamic and structural probes. While the system dynamics are polymer-like with increased friction for low silica loadings, they turn network-like when the mean face-to-face separation between NPs becomes smaller than the entanglement tube diameter. Gel-like dynamics with a Williams-Landel-Ferry temperature dependence then result. This dependence turns particle dominated, that is, Arrhenius-like, when the silica loading increases to similar to 31 vol%, namely, when the average nearest distance between NP faces becomes comparable to the polymer's Kuhn length. Our results demonstrate that the flow properties of nanocomposites are complex and can be tuned via changes in filler loading, that is, the character of polymer bridges which 'tie' NPs together into a network.We thank Leon Serc (ETH Zurich) for help with FTIR. Enlightening discussions with Ulrich Jonas are gratefully acknowledged. Partial support has been provided by the EU FP7 (ETN Supolen GA-607937, Infrastructure ESMI GA-262348) and the Greek General Secretariat for Research and Technology (Thalis-380238 COVISCO). M.R. acknowledges financial support from the National Science Foundation under grants DMR-1309892, DMR-1436201 and DMR-1121107, the National Institutes of Health under grants P01-HL108808 and 1UH2HL123645 and the Cystic Fibrosis Foundation. D.Z., S.G., R.H.C. and S.K.K. gratefully acknowledge the National Science Foundation grant DMR-1408323 for financial support