3,763 research outputs found

    Luminescence dating and mineralogical investigations of bricks from erikli basilica in Stratonikeia ancient city (SW-Turkey)

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    Stratonikeia is one of the oldest settlements in southwestern Anatolia and at the same time significant for an understanding of the Hellenistic period. Archaeological records of Stratonikeia date back to around 2000 BC. This study provides new information not only about luminescence age but also about mineralo-petrographic, geochemical characteristics of bricks taken from Erikli Basilica in Stratonikeia (Turkey). In this study, mineralogical data of TL and OSL dating of two bricks and two sediment samples will be presented. The bricks have highly similar mineralogical composition, consisting mainly of quartz and muscovite. These results are supported by XRD studies. In order to perform the thermoluminescence (TL) and optically stimulated luminescence (OSL) dating, the equivalent dose (ED) and the annual dose (AD) of the samples were determined using different estimation techniques. The TL ages of bricks are determined to be 1189±89 and 576±40 years. The IRSL ages of the bricks are determined to be 1167±85 years and 545±50 years. Additionally, supporting the TL and IRSL ages, the OSL quartz ages of the two sediments obtained from the top of the layer under the floor are discovered to be about 1100 years. Mineralo-petrographic, geochemical, dating and archaeological studies have revealed that the age of bricks is different from each other. Furthermore, Erikli Basillica was built in bricks, consisting of raw materials taken from different quarries in different periods. Within the framework, the first report of the experimental approach has been published from Stratonikeia archaeological site located in Muğla, Agean Anatolia. © 2018 MAA Open Access. Printed in Greece. All rights reserved

    Optimal trajectory generation in ocean flows

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    In this paper it is shown that Lagrangian Coherent Structures (LCS) are useful in determining near optimal trajectories for autonomous underwater gliders in a dynamic ocean environment. This opens the opportunity for optimal path planning of autonomous underwater vehicles by studying the global flow geometry via dynamical systems methods. Optimal glider paths were computed for a 2-dimensional kinematic model of an end-point glider problem. Numerical solutions to the optimal control problem were obtained using Nonlinear Trajectory Generation (NTG) software. The resulting solution is compared to corresponding results on LCS obtained using the Direct Lyapunov Exponent method. The velocity data used for these computations was obtained from measurements taken in August, 2000, by HF-Radar stations located around Monterey Bay, CA

    Bounds on Parameters in Dynamic Discrete Choice Models

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    Identification of dynamic nonlinear panel data models is an important and delicate problem in econometrics. In this paper we provide insights that shed light on the identification of parameters of some commonly used models. Using this insight, we are able to show through simple calculations that point identification often fails in these models. On the other hand, these calculations also suggest that the model restricts the parameter to lie in a region that is very small in many cases, and the failure of point identification may therefore be of little practical importance in those cases. Although the emphasis is on identification, our techniques are constructive in that they can easily form the basis for consistent estimates of the identified sets.

    Multi-Competitive Viruses over Static and Time--Varying Networks

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    Epidemic processes are used commonly for modeling and analysis of biological networks, computer networks, and human contact networks. The idea of competing viruses has been explored recently, motivated by the spread of different ideas along different social networks. Previous studies of competitive viruses have focused only on two viruses and on static graph structures. In this paper, we consider multiple competing viruses over static and dynamic graph structures, and investigate the eradication and propagation of diseases in these systems. Stability analysis for the class of models we consider is performed and an antidote control technique is proposed

    On the Analysis of a Continuous-Time Bi-Virus Model

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    Motivated by the spread of opinions on different social networks, we study a distributed continuous-time bi-virus model for a system of groups of individuals. An in-depth stability analysis is performed for more general models than have been previously considered, for the healthy and epidemic states. In addition, we investigate sensitivity properties of some nontrivial equilibria and obtain an impossibility result for distributed feedback control

    FGF4 retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs.

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    Chondrodystrophy in dogs is defined by dysplastic, shortened long bones and premature degeneration and calcification of intervertebral discs. Independent genome-wide association analyses for skeletal dysplasia (short limbs) within a single breed (PBonferroni = 0.01) and intervertebral disc disease (IVDD) across breeds (PBonferroni = 4.0 × 10-10) both identified a significant association to the same region on CFA12. Whole genome sequencing identified a highly expressed FGF4 retrogene within this shared region. The FGF4 retrogene segregated with limb length and had an odds ratio of 51.23 (95% CI = 46.69, 56.20) for IVDD. Long bone length in dogs is a unique example of multiple disease-causing retrocopies of the same parental gene in a mammalian species. FGF signaling abnormalities have been associated with skeletal dysplasia in humans, and our findings present opportunities for both selective elimination of a medically and financially devastating disease in dogs and further understanding of the ever-growing complexity of retrogene biology

    Synthesis of Novel 6-(4-Substituted piperazine-1-yl)-9(b-D-ribofuranosyl) purine Derivatives, Which Lead to Senescence-Induced Cell Death in liver Cancer Cells

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    Cataloged from PDF version of article.Novel purine ribonucleoside analogues (9-13) containing a 4-substituted piperazine in the substituent at N-6 were synthesized and evaluated for their cytotoxicity on Huh7, HepG2, FOCUS, Mahlavu liver, MCF7 breast, and HCT116 colon carcinoma cell lines. The purine nucleoside analogues were analyzed initially by an anticancer drug-screening method based on a sulforhodamine B assay. Two nucleoside derivatives with promising cytotoxic activities (11 and 12) were further analyzed on the hepatoma cells. The N-6-(4-Trifluoromethylphenyl)piperazine analogue 11 displayed the best antitumor activity, with IC50 values between 5.2 and 9.2 mu M. Similar to previously described nucleoside analogues, compound 11 also interferes with cellular ATP reserves, possibly through influencing cellular kinase activities. Furthermore, the novel nucleoside analogue 11 was shown to induce senescence-associated cell death, as demonstrated by the SA beta-gal assay. The senescence-dependent cytotoxic effect of 11 was also confirmed through phosphorylation of the Rb protein by p15(INK4b) overexpression in the presence of this compound
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