(R1517) Asymptotical Stability of Riemann-Liouville Fractional Neutral Systems with Multiple Time-varying Delays

In this manuscript, we investigate the asymptotical stability of solutions of Riemann-Liouville fractional neutral systems associated to multiple time-varying delays. Then, we use the linear matrix inequality (LMI) and the Lyapunov-Krasovskii method to obtain sufficient conditions for the asymptotical stability of solutions of the system when the given delays are time dependent and one of them is unbounded. Finally, we present some examples to indicate the efficacy of the consequences obtained

On the Qualitative Analysis of Volterra IDDEs with Infinite Delay

This investigation deals with a nonlinear Volterra integro-differential equation with infinite retardation (IDDE).We will prove three new results on the stability, uniformly stability (US) and square integrability (SI) of solutions of that IDDE. The proofs of theorems rely on the use of an appropriate Lyapunov-Krasovskii functional (LKF). By the outcomes of this paper, we generalize and obtain some former results in mathematical literature under weaker conditions

Oil Prices and Global Stock Markets: A Time-Varying Causality-In-Mean and Causality-in-Variance Analysis

This study examines the Granger-causal relationships between oil price movements and global stock returns by using time-varying Granger-causality tests in mean and in variance. We use the daily returns from Morgan Stanley Capital International (MSCI) G7 and the MSCI Emerging Stock Market Indexes to distinguish between the effects of daily oil price movements on G7 countries' and emerging market countries' stock markets. We further divide the emerging markets into two groups as oil-exporting and oil-importing countries. For the oil market, we use both the West Texas Intermediate (WTI) and Brent oil daily price movements. While the Granger-causality-in-mean tests indicate a causal link from WTI oil prices and G7 countries' stock returns to MSCI emerging countries' stock returns, the Granger-causality-in-variance tests suggest no causal link from global oil market prices to stock market returns. Nonetheless, a causal link from the G7 countries' stock returns to the MSCI emerging countries' stock returns is detected. In addition, G7 countries' stock market volatility is found to Granger-cause Brent oil price volatility. The time-varying Granger-causality-in-mean and Granger-causality-in-variance tests present new and further insights. A causal relationship between oil price changes and G7 countries' stock returns is found for some periods during and after the global financial crisis. Time-varying Granger-causality-in-variance test results indicate evidence of causal linkages among oil prices and global stock market returns that are specific only to certain time periods. We also find that there might be a difference between the movements in Brent and WTI oil prices with respect to their Granger-causal effects on oil-importing emerging markets' stock returnsespecially after the global financial crisis. Our results provide further evidence that the effects of oil price movements on stock returns might be different depending on the volatility in the stock markets

Series expansions and polynomial approximations of Monomolecular growth model for some populations of Eucalyptus camaldulensis Dehn. from Eastern Mediterranean Forest Research Manager

I n this study, firstly the series expansions of monomolecular growth model from first degree polynomial to n-1 th degree polynomial, were given with respect to t-r where t is time, n is the number of data, r is integer number: 0t≤ ≤nal values of time, respectively. Secondly, monomolecular growth model's series expansions having m-th degree polynomials, studied on the data taken for Eucalyptus camaldulensis Dehn. from Eastern Mediterranean Forest Research Manager were given with R2 with respect to t-k , respectively where t is time; n is the number of data points; m, k are integer numbers 1m nhaving m-th degree were given with R2. For each purpose, the tables and the graphs were used for analyzing the difference

Apoptosis biomarkers (Apaf-1, sFa s, sFa s-L, and caspase-9), albumin, and fetuin-A levels in pulmonary thromboembolic patients

INTRODUCTION: Pulmonary thromboembolism (PE) is the third most common medical emergency with mortality due to ischemia and reperfusion lung injury. Lung ischaemia-reperfusion injury. Lung reperfusion damage is believed to cause cellular damage and apoptosis. The aim of the present study was to evaluate the levels of fetuin-A, albumin, and apoptosis biomarkers (Apaf-1, sFas, and sFasL) among pulmonary thromboembolic patients. MATERIAL AND METHODS: Blood samples were collected from 45 volunteer patients and 40 healthy control volunteers. Human apoptosis biomarkers (Apaf-1, sFas, sFasL, and caspase-9) and fetuin-A values were measured by ELISA device. Student’s t-test or Mann-Whitney U test were used for continuous variables, and categorical variables were compared with the chi-square test to assess the significance of intergroup differences. The mean values of apoptosis biomarkers and acute phase reactants between dead and survival patients were also compared. RESULTS: While the apoptosis mean values of Apaf-1, sFas, sFasL, and caspase-9 for the control group were 0.12 ± 0.01, 332.1 ± 28.0, 130.4 ± 34.6, and 74.3 ± 2.6, for the patient group they were 0.14 ± 0.02, 509.1 ± 67.6, 139.9 ± 23.7, and 79.4 ± 2.8, respectively. The group differences were significant for all the biomarkers (p = 0.01, p = 0.001, p = 0.19, and p = 0.01, respectively). The negative acute phase fetuin- A and albumin levels decreased significantly in the patient groups (p = 0.01 and p = 0.01, respectively). CONCLUSİONS: Intrinsic and extrinsic apoptosis pathways are stimulated during pulmonary embolism, and negative acute phase reactants are decreased. There was a correlation with the mortality and Apaf-1, sFas, caspase-9, fetuin, and albumin levels

Nonlinearity and nonstationarity in international art market prices: evidence from Markov-switching ADF unit root tests

This study investigates the presence (or lack thereof) of nonlinear dynamics and nonstationarity in international art market prices using quarterly data for the period 1990-2011. We first test whether art market price indices follow stochastic trends or whether they are stationary by means of linear unit root tests. Next, we estimate the Markov regime-switching ADF model and test whether the linear or the nonlinear regime-switching model provides a better characterization of the global art market price series. We find that all art market price indices (except for Drawings) exhibit nonlinearity. To our knowledge, our study is the first one in the literature to suggest that a nonlinear (Markov regime-switching) model provides a better characterization of the behavior of price dynamics in international art markets. In particular, our findings indicate that the market for the overall global art market, paintings, old masters, sculptures, photographs, prints, and contemporary art might indeed be stationary while exhibiting nonlinear regime-switching properties. On the other hand, the market for drawings and the Nineteenth century art are found to be nonstationary. Overall, despite the common ground of a regime-switching framework, we still find that the sub-segments of the art market have their own inner regime switching dynamics and hence they can evolve differently overtim

Downside Business Confidence Spillovers in Europe: Evidence from Causality-in-Risk Tests

This paper employs Hong et al.’s (2009) extreme risk spillovers test to investigate the bilateral business confidence spillovers between Greece, Italy, Spain, Portugal, France, and Germany. After controlling for domestic economic developments in each country and common international factors, downside risk spillovers are detected as a causal feedback between Spain and Portugal and unilaterally from Spain to Italy. Extremely low business sentiments in France, Germany, and Greece are mostly due to the common adverse economic environment and to each country’s own domestic economic developments

A Compact Microstrip Spiral Antenna Embedded in Water Bolus for Hyperthermia Applications

This paper presents the design, simulation, fabrication, and measurement of a circular spiral microstrip antenna embedded in distilled water bolus. The antenna is mainly designed to operate at 434 MHz ISM band to be used for a hyperthermia applicator. The performance of the antenna is compared to a conventional patch antenna also embedded in water bolus. The results show that spiral antenna has significant narrower radiation pattern and is capable to operate at multiple frequencies as well. Narrow beam of the antenna is desired to design a multiantenna arrangement with less coupling and a better focusing resolution which can be crucial for deep regional hyperthermia applications. The option of other frequencies is desirable to have a better control over the penetration depth versus focusing depending on the application region

Absorption and Fluorescence Spectroscopy of 1,2 : 3,4-Dibenzanthracene

Polycyclic aromatic hydrocarbon compound, 1,2 : 3,4-dibenzanthracene, is spectroscopically analyzed in ethanol. Ultraviolet absorption spectra were taken and fluorescence measurements were performed. From absorption and emission spectra, Stokes' lines were clearly discernible and these shifts were recorded. Being a carcinogenic compound, the detection of 1,2 : 3,4-dibenzanthracene presence in the environment as a pollutant with adverse genotoxic effects is vital

Optical Energy Transfer Mechanisms: From Naphthalene to Biacetyl in Liquids and from Pyrazine to Biacetyl

Optical energy transfer from naphthalene to biacetyl in liquids at room temperature is studied. Electronically excited naphthalene with 200–260 nm ultraviolet (UV) light emits photons in its emission band and the emitted photons are absorbed by biacetyl, which, in turn, excites biacetyl phosphorescence. The resulting phosphorescence is very stable with emission peak at 545 nm for different excitation wavelengths from 200 to 260 nm. Similar optical energy transfer is also observed from pyrazine to biacetyl. The sensitization of biacetyl by several aromatic donors has been investigated in detail. An aromatic donor, pyrazine, is raised to its first excited singlet state by absorption of ultraviolet radiation. Excitation wavelengths were selected in the first - band of pyrazine. Intersystem crossing in pyrazine is sufficiently fast to give a triplet yield of almost unity as determined by the biacetyl method. The optical excess energy in the biacetyl will be released as light, which is sensitized fluorescence. Biacetyl is the simplest molecule among a wide range of -dicarbonyl compounds, which is important for photophysics and photochemistry applications