9,993 research outputs found

    Social Identity and the Mexican Community

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    The election of President Trump can be shown to negatively impact the Mexican community through social identity theory. Since his election, President Trump has passed policies controlling immigration and uses harmful language to describe Mexicans, such as rapists and criminals. To investigate the impact that the presidency has had on the Mexican Community the author choose to analyze this influence with social identity theory. Social identity theory proposes that individuals’ self-concept is based on their identification to their ingroup, and when this ingroup (Mexican) is viewed unfavorably by the outgroup (Anglo-American), negative social identity occurs. The author interviewed 16 participants that work and are students in a university and identify as Mexican or Mexican American. Findings support that there was a difference in the participants who experienced negative social identity. Those participants with American citizenship indicated to have negative social identity when they spoke about Trump’s Presidency and policies, however, those participants without American citizenship such as DACA recipients showed to be discouraged more so because of the uncertainty of their future with immigration policies, and not negative social identity. My hypothesis that negative social identity will influence motivation in lifestyle was not supported

    Finite element differential forms on curvilinear cubic meshes and their approximation properties

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    We study the approximation properties of a wide class of finite element differential forms on curvilinear cubic meshes in n dimensions. Specifically, we consider meshes in which each element is the image of a cubical reference element under a diffeomorphism, and finite element spaces in which the shape functions and degrees of freedom are obtained from the reference element by pullback of differential forms. In the case where the diffeomorphisms from the reference element are all affine, i.e., mesh consists of parallelotopes, it is standard that the rate of convergence in L2 exceeds by one the degree of the largest full polynomial space contained in the reference space of shape functions. When the diffeomorphism is multilinear, the rate of convergence for the same space of reference shape function may degrade severely, the more so when the form degree is larger. The main result of the paper gives a sufficient condition on the reference shape functions to obtain a given rate of convergence.Comment: 17 pages, 1 figure; v2: changes in response to referee reports; v3: minor additional changes, this version accepted for Numerische Mathematik; v3: very minor updates, this version corresponds to the final published versio

    Competitive nucleation in metastable systems

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    Metastability is observed when a physical system is close to a first order phase transition. In this paper the metastable behavior of a two state reversible probabilistic cellular automaton with self-interaction is discussed. Depending on the self-interaction, competing metastable states arise and a behavior very similar to that of the three state Blume-Capel spin model is found

    Basic Ideas to Approach Metastability in Probabilistic Cellular Automata

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    Cellular Automata are discrete--time dynamical systems on a spatially extended discrete space which provide paradigmatic examples of nonlinear phenomena. Their stochastic generalizations, i.e., Probabilistic Cellular Automata, are discrete time Markov chains on lattice with finite single--cell states whose distinguishing feature is the \textit{parallel} character of the updating rule. We review some of the results obtained about the metastable behavior of Probabilistic Cellular Automata and we try to point out difficulties and peculiarities with respect to standard Statistical Mechanics Lattice models.Comment: arXiv admin note: text overlap with arXiv:1307.823

    A comparison between different cycle decompositions for Metropolis dynamics

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    In the last decades the problem of metastability has been attacked on rigorous grounds via many different approaches and techniques which are briefly reviewed in this paper. It is then useful to understand connections between different point of views. In view of this we consider irreducible, aperiodic and reversible Markov chains with exponentially small transition probabilities in the framework of Metropolis dynamics. We compare two different cycle decompositions and prove their equivalence

    Automated and Interpretable Patient ECG Profiles for Disease Detection, Tracking, and Discovery

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    The electrocardiogram or ECG has been in use for over 100 years and remains the most widely performed diagnostic test to characterize cardiac structure and electrical activity. We hypothesized that parallel advances in computing power, innovations in machine learning algorithms, and availability of large-scale digitized ECG data would enable extending the utility of the ECG beyond its current limitations, while at the same time preserving interpretability, which is fundamental to medical decision-making. We identified 36,186 ECGs from the UCSF database that were 1) in normal sinus rhythm and 2) would enable training of specific models for estimation of cardiac structure or function or detection of disease. We derived a novel model for ECG segmentation using convolutional neural networks (CNN) and Hidden Markov Models (HMM) and evaluated its output by comparing electrical interval estimates to 141,864 measurements from the clinical workflow. We built a 725-element patient-level ECG profile using downsampled segmentation data and trained machine learning models to estimate left ventricular mass, left atrial volume, mitral annulus e' and to detect and track four diseases: pulmonary arterial hypertension (PAH), hypertrophic cardiomyopathy (HCM), cardiac amyloid (CA), and mitral valve prolapse (MVP). CNN-HMM derived ECG segmentation agreed with clinical estimates, with median absolute deviations (MAD) as a fraction of observed value of 0.6% for heart rate and 4% for QT interval. Patient-level ECG profiles enabled quantitative estimates of left ventricular and mitral annulus e' velocity with good discrimination in binary classification models of left ventricular hypertrophy and diastolic function. Models for disease detection ranged from AUROC of 0.94 to 0.77 for MVP. Top-ranked variables for all models included known ECG characteristics along with novel predictors of these traits/diseases.Comment: 13 pages, 6 figures, 1 Table + Supplemen

    A case of metastatic Wilms’ tumour with reversible distortion of mediastinal anatomy : a diagnostic challenge for the echocardiographer

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    Delineation and documentation of anatomy in the presence of significant mass pathology presents a diagnostic challenge. This often necessitates the implementation of more than one imaging modality in order to perform an adequate assessment. We present a three-year old boy with extensive distortion of mediastinal anatomy secondary to pleural metastases from a Wilms tumour. This limited the ability to accurately assess mediastinal anatomy and cardiac function at baseline. Reassessment following initiation of chemotherapy showed a significant reduction in size of metastases with complete resolution of the mediastinal distortion.peer-reviewe

    Stochastic Turing Patterns on a Network

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    The process of stochastic Turing instability on a network is discussed for a specific case study, the stochastic Brusselator model. The system is shown to spontaneously differentiate into activator-rich and activator-poor nodes, outside the region of parameters classically deputed to the deterministic Turing instability. This phenomenon, as revealed by direct stochastic simulations, is explained analytically, and eventually traced back to the finite size corrections stemming from the inherent graininess of the scrutinized medium.Comment: The movies referred to in the paper are provided upon request. Please send your requests to Duccio Fanelli ([email protected]) or Francesca Di Patti ([email protected]
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