758 research outputs found

    Complex Shepard Operators and Their Summability

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    In this paper, we construct the complex Shepard operators to approximate continuous and complex-valued functions on the unit square. We also examine the effects of regular summability methods on the approximation by these operators. Some applications verifying our results are provided. To illustrate the approximation theorems graphically we consider the real or imaginary part of the complex function being approximated and also use the contour lines of the modulus of the function

    Rates of A-statistical convergence of positive linear operators

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    AbstractIn this paper we study the rates of A-statistical convergence of sequences of positive linear operators mapping the weighted space Cρ1 into the weighted space Bρ2

    Hierarchical Over-the-Air Federated Edge Learning

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    Federated learning (FL) over wireless communication channels, specifically, over-the-air (OTA) model aggregation framework is considered. In OTA wireless setups, the adverse channel effects can be alleviated by increasing the number of receive antennas at the parameter server (PS), which performs model aggregation. However, the performance of OTA FL is severely limited by the presence of mobile users (MUs) located far away from the PS. In this paper, to mitigate this limitation, we propose hierarchical over-the-air federated learning (HOTAFL), which utilizes intermediary servers (IS) to form clusters near MUs. We provide a convergence analysis for the proposed setup, and demonstrate through experimental results that local aggregation in each cluster before global aggregation leads to a better performance and faster convergence than OTA FL

    The accuracy rate of Alvarado score, ultrasonography, and computerized tomography scan in the diagnosis of acute appendicitis in our center

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    Objective: In this study, we aim to compare the relationship between the Alvarado score, ultrasonography, and multislice computerized tomography (CT) findings used for the diagnosis of the patients who presented to our emergency unit with clinical features suggestive of acute appendicitis.Materials and Methods: Seventy.four patients operated with the diagnosis of acute appendicitis were included in the study. The demographic  characteristics of the patients, physical findings, blood parameters,  Alvarado scores, the radiological method used for the diagnosis, the  surgical methods (open or laparoscopic) and the pathology results wererecorded on the standard proforma. The collected data were analyzed with Statistical Package for Social Sciences (SPSS 15 for Windows, SPSS Inc., Chicago, Illinois, USA) computer program.Results: During study period, the sensitivity of ultrasonography was found to be as 71.2%, specificity as 46.7%, the positive predictive value (PPV) as 82.2%, the negative predictive value (NPV) as 31.8%, and the accuracy  rate was determined as 65.7%. The sensitivity of tomography was  determined as 97.2%, the specificity as 62.5%, PPV as 92.1%, and NPV as 83.3%, and the accuracy rate was determined as 90%. The sensitivity of  the Alvarado score was calculated as 54%, the specificity as 73.3%, the PPV as 88.2% and the NPV as 29.7%, and the accuracy rate was determined as 57.7%.Conclusion: In conclusion, computerized tomography (CT) was found to have higher specificity and sensitivity than Alvarado score and USG which are not sufficient on their own for taking the decision for surgery. We also found that CT scan had lower negative laparotomy rate when compared with the other two modalities.Key words: Alvarado score, appendicitis, computerized tomography, ultrasonograph

    "Civilianization" in Greece versus "demilitarization" in Turkey: A comparative study of civil-military relations and the impact of the European Union

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    The civil-military-relations literature has long concentrated on domestic factors in explaining the relationship between civilians and the military. This article concentrates on the effect of an external actor, the European Union (EU), on civil-military relations in Greece and Turkey. The main findings reveal that the two countries shared similar characteristics until the mid-1970s. However, their path of civil-military relations diverged considerably as soon as Greece's EU membership prospect became tangible. While in the Greek case, "civilianization" took place, Turkey had witnessed a mere "demilitarization" of its regime. However, the article also shows how EU membership paves the way for the improvement of civil-military relations in the Turkish case. © 2006, Inter-University Seminar on Armed Forces and Society. All rights reserved

    Evaluation of localisation of mandibular foramen in patients with mandibular third molar teeth using cone-beam computed tomography

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    Background: It is important to know the correct anatomical location of the mandibular foramen to obtain successful anaesthesia of inferior alveolar nerve and to prevent injury to the mandibular vessels and nerve, during a variety of oral and maxillofacial surgical procedures. The aim of this study is to evaluate localisation of the mandibular foramen in patients with the third molars using cone-beam computed tomography (CBCT). Materials and methods: Cone-beam computed tomography was used to determine the location of the mandibular foramen in 67 patients (totally 99 sides) with unilateral or bilateral impacted mandibular third molars. Results: The distance from the posterior border of the mandibular ramus to mandibular foramen did not differ significantly among the other angulations. But the difference between vertical and horizontal angulation of the impactedmandibular third molars according to ‘fd’ values (the shortest distance between mandibular foramen and the posterior border of mandibular ramus) was found to be statistically significant (p < 0.05). Conclusions: The present study provides new information to the literature concerning relationship between the location of the mandibular foramen and the mandibular third molars

    Disorder induced critical phenomena in magnetically glassy Cu-Al-Mn alloys

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    Measurements of magnetic hysteresis loops in Cu-Al-Mn alloys of different Mn content at low temperatures are presented. The loops are smooth and continuous above a certain temperature, but exhibit a magnetization discontinuity below that temperature. Scaling analysis suggest that this system displays a disorder induced phase transition line. Measurements allow to determine the critical exponents β=0.03±0.01\beta=0.03\pm 0.01 and βδ=0.4±0.1\beta \delta = 0.4 \pm 0.1 in agreement with those reported recently [Berger et al., Phys. Rev. Lett. {\bf 85}, 4176 (2000)]Comment: 4 pages, 5 figure

    Inverse magnetocaloric effect in ferromagnetic Ni-Mn-Sn alloys

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    The magnetocaloric effect (MCE) in paramagnetic materials has been widely used for attaining very low temperatures by applying a magnetic field isothermally and removing it adiabatically. The effect can be exploited also for room temperature refrigeration by using recently discovered giant MCE materials. In this letter, we report on an inverse situation in Ni-Mn-Sn alloys, whereby applying a magnetic field adiabatically, rather than removing it, causes the sample to cool. This has been known to occur in some intermetallic compounds, for which a moderate entropy increase can be induced when a field is applied, thus giving rise to an inverse magnetocaloric effect. However, the entropy change found for some ferromagnetic Ni-Mn-Sn alloys is just as large as that reported for giant MCE materials, but with opposite sign. The giant inverse MCE has its origin in a martensitic phase transformation that modifies the magnetic exchange interactions due to the change in the lattice parameters.Comment: 12 pages, 4 figures, to appear in Nature Materials (online published, 15 May 2005

    Coxiella burnetii Phagocytosis Is Regulated by GTPases of the Rho Family and the RhoA Effectors mDia1 and ROCK

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    The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the host´s cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C. burnetii by phagocytic and non-phagocytic cells. The internalization of C. burnetii into HeLa and RAW cells was significantly inhibited when the cells were treated with Clostridium difficile Toxin B which irreversibly inactivates members of the Rho family. In addition, the internalization was reduced in HeLa cells that overexpressed the dominant negative mutants of RhoA, Rac1 or Cdc42 or that were knocked down for the Rho GTPases. The pharmacological inhibition or the knocking down of ROCK diminished bacterium internalization. Moreover, C. burnetii was less efficiently internalized in HeLa cells overexpressing mDia1-N1, a dominant negative mutant of mDia1, while the overexpression of the constitutively active mutant mDia1-ΔN3 increased bacteria uptake. Interestingly, when HeLa and RAW cells were infected, RhoA, Rac1 and mDia1 were recruited to membrane cell fractions. Our results suggest that the GTPases of the Rho family play an important role in C. burnetii phagocytosis in both HeLa and RAW cells. Additionally, we present evidence that ROCK and mDia1, which are downstream effectors of RhoA, are involved in that processFil: Salinas Ojeda, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Ortiz Flores, Rodolfo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Distel, Jesús Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Aguilera, Milton Osmar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Beron, Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin
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