1,028 research outputs found

    Large deviations for random walk in a random environment

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    In this work, we study the large deviation properties of random walk in a random environment on Zd\mathbb{Z}^d with d1d\geq1. We start with the quenched case, take the point of view of the particle, and prove the large deviation principle (LDP) for the pair empirical measure of the environment Markov chain. By an appropriate contraction, we deduce the quenched LDP for the mean velocity of the particle and obtain a variational formula for the corresponding rate function IqI_q. We propose an Ansatz for the minimizer of this formula. This Ansatz is easily verified when d=1d=1. In his 2003 paper, Varadhan proves the averaged LDP for the mean velocity and gives a variational formula for the corresponding rate function IaI_a. Under the non-nestling assumption (resp. Kalikow's condition), we show that IaI_a is strictly convex and analytic on a non-empty open set A\mathcal{A}, and that the true velocity ξo\xi_o is an element (resp. in the closure) of A\mathcal{A}. We then identify the minimizer of Varadhan's variational formula at any ξA\xi\in\mathcal{A}. For walks in high dimension, we believe that IaI_a and IqI_q agree on a set with non-empty interior. We prove this for space-time walks when the dimension is at least 3+1. In the latter case, we show that the cheapest way to condition the asymptotic mean velocity of the particle to be equal to any ξ\xi close to ξo\xi_o is to tilt the transition kernel of the environment Markov chain via a Doob hh-transform.Comment: 82 pages. PhD thesis. Advisor: S.R.S. Varadha

    Histopathologic and immunohistochemical investigations of dental abscess formed in maxillofacial area

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    Background: An abscess is a pocket of pus that forms around the root of an infected tooth. In this study, we aimed to investigate the extracellular matrix proteases ADAMTS1, ADAMTS4, osteonectin, and osteopontin expressions in abscess fluid cells in jaws after implantation and prosthesis operation. Materials and methods: In this clinical study, abscess fluids belonging to 17 patients who applied to the Department of Oral and Maxillofacial Surgery were examined histopathologically and immunohistochemically. In the histopathological examination of the abscess fluid, separation of chromatin bridges in the nuclei of neutrophil cells, pyknosis and apoptotic changes in the nucleus, degenerative change in the cytoplasm, and occasional vacuolar structures were observed. Results: The positive reaction of ADAMTS1 was observed in fibroblast cells, plasma cells, and macrophage cells. The positive reaction of ADAMTS4 was observed in fibroblast cells, osteoclast cells, and some apoptotic leukocyte cells. Osteopontin expression in osteoclastic cells and polymorphonuclear cells was defined as positive. Osteonectin expression was positive in polymorphonuclear leukocytes and hypertrophic fibroblast cells. Conclusions: ADAMTS1 and ADAMTS4 may induce bone destruction with its distinctive property in alveolar bone resorption, which promotes the activation of osteoclasts, which can accelerate the destruction of the extracellular matrix in the acute phase. Furthermore, osteoclastic activity increased with the increase of osteonectin and osteopontin protein expression due to inflammation in the abscess cases

    The Effect of pH in Nickel Ferrite Nanoparticles Synthesis by Hydrothermal Method

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    In this study, NiFe2O4 nano particles was prepared with aqueous solutions of nickel nitrate and ferric nitrate salts. An appropriate ratio of solutions nickel nitrate and ferric nitrate were dissolved in deionized water and poured into a crucible. Later, polyethylene glycol 600 (PEG 600) was added to this mixture. Samples were adjusted to various pH values. In experiments, samples obtained by hydrothermal method were heat treated at 700 oC for 8 h to enhance their crystallinity and remove the residual organic materials. The structural and morphological properties of NiFe2O4 nano particles were determined by X-ray powder diffraction (XRD) and Scanning Electron microscopy (SEM). Results showed that increasing calcination temperature contributed to cyristallinity of NiFe2O4 nano particles. But also average particle size increased. As a result, average particle size was calculated by using Debye-Scherrer Formula as aproximately 30 nm. However, this results was confirmed with SEM analysis. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3502

    The Effect of Calcination Temperature in NiFe2O4 Nanoparticles Synthesis with Microvawe Combustion Method

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    Magnetic ferrites are a group of technologically important magnetic materials. Synthesis of nanocrystalline spinel ferrite has been investigated intensively in recent years due to their potential applications in high-density magnetic recording, microwave devices, and magnetic fluids In this study, NiFe2O4 nano particles were prepared with microvawe combustion methods. In experiments, samples obtained by microvawe method were calcined at various temperatures. The structural and morphological properties of NiFe2O4 nano particles was determined by X-ray powder diffraction (XRD) and Scanning Electron microscopy (SEM). Results showed that increasing calcination temperature contributed to cyristallinity of NiFe2O4 nanoparticles. But also average particle size increased. As a result, average particle size calculated by using Debye-Scherrer Formula as aproximately 30 nm. However, this results was confirmed with SEM analysis. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3502

    Robust Inference of Kinase Activity Using Functional Networks

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    Mass spectrometry enables high-throughput screening of phosphoproteins across a broad range of biological contexts. When complemented by computational algorithms, phospho-proteomic data allows the inference of kinase activity, facilitating the identification of dysregulated kinases in various diseases including cancer, Alzheimer’s disease and Parkinson’s disease. To enhance the reliability of kinase activity inference, we present a network-based framework, RoKAI, that integrates various sources of functional information to capture coordinated changes in signaling. Through computational experiments, we show that phosphorylation of sites in the functional neighborhood of a kinase are significantly predictive of its activity. The incorporation of this knowledge in RoKAI consistently enhances the accuracy of kinase activity inference methods while making them more robust to missing annotations and quantifications. This enables the identification of understudied kinases and will likely lead to the development of novel kinase inhibitors for targeted therapy of many diseases. RoKAI is available as web-based tool at http://rokai.io

    A Jupiter-mass planet around the K0 giant HD 208897

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    For over 10 years, we have carried out a precise radial velocity (RV) survey to find substellar companions around evolved G,K-type stars to extend our knowledge of planet formation and evolution. We performed high precision RV measurements for the giant star HD 208897 using an iodine (I2) absorption cell. The measurements were made at T\"UB\.ITAK National Observatory (TUG, RTT150) and Okayama Astrophysical Observatory (OAO). For the origin of the periodic variation seen in the RV data of the star, we adopted a Keplerian motion caused by an unseen companion. We found that the star hosts a planet with a minimum mass of m2sini=1.40MJ, which is relatively low compared to those of known planets orbiting evolved intermediate-mass stars. The planet is in a nearly circular orbit with a period of P=353 days at about 1 AU distance from the host star. The star is metal rich and located at the early phase of ascent along the red giant branch. The photometric observations of the star at Ankara University Kreiken Observatory (AUKR) and the HIPPARCOS photometry show no sign of variation with periods associated with the RV variation. Neither bisector velocity analysis nor analysis of the Ca II and Halpha lines shows any correlation with the RV measurements

    Clear otorrhea: a case of Munchausen syndrome in a pediatric patient

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    This paper reports a case of Munchausen syndrome in a pediatric patient. An 11-year-old girl presented with the complaint of clear fluid otorrhea. She underwent numerous investigations with deception of the physicians. The literature with respect to Munchausen syndrome in the pediatric patient is reviewed. Diagnosis of Munchausen syndrome is difficult especially during the initial assessment, although suspicion might be aroused by inconsistencies in the patient’s history and discrepancies between signs and symptoms
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