Linearized Holographic Isotropization at Finite Coupling

We study holographic isotropization of an anisotropic homogeneous non-Abelian strongly coupled plasma in the presence of Gauss-Bonnet corrections. It was verified before that one can linearize Einstein's equations around the final black hole background and simplify the complicated setup. Using this approach, we study the expectation value of the boundary stress tensor. Although we consider small values of the Gauss-Bonnet coupling constant, it is found that finite coupling leads to significant increasing of the thermalization time. By including higher order corrections in linearization, we extend the results to study the effect of the Gauss-Bonnet coupling on the entropy production on the event horizon.Comment: V2 and v3 are the same! version 4 is ne

Holographic energy loss in non-relativistic backgrounds

In this paper, we study some aspects of energy loss in non-relativistic theories from holography. We analyze the energy lost by a rotating heavy point particle along a circle of radius $l$ with angular velocity $\omega$ in theories with general dynamical exponent $z$ and hyperscaling violation exponent $\theta$. It is shown that this problem provides a novel perspective on the energy loss in such theories. A general computation at zero and finite temperature is done and it is shown that how the total energy loss rate depends non-trivially on two characteristic exponents $(z,\theta)$. We find that at zero temperature there is a special radius $l_c$ where the energy loss is independent of different values of $(\theta,z)$. Also at zero temperature, there is a crossover between a regime in which the energy loss is dominated by the linear drag force and by the radiation because of the acceleration of the rotating particle. We find that the energy loss of the particle decreases by increasing $\theta$ and $z$. We note that, unlike in the zero temperature, there is no special radius $l_c$ at finite temperature case.Comment: 16 pages, major revision of finite temperature analysi

Anomalous dimension and quasinormal modes of flavor branes

We study scalar quasinormal modes in a D3/D7 system holographically dual to a quantum field theory with chiral symmetry breaking at finite temperature. Using the spectral method, we show that there is no a pure imaginary mode for massless quarks but it appears by increasing the anomalous dimension of the quark condensate. It is known that this mode becomes tachyonic for massive quarks. Then we turn on a pseudoscalar field and using a simple ansatz study its effect on the quasinormal modes of the scalar field. By varying the parameter of the non trivial dilaton profile in the model, we qualitatively study quasinormal modes in walking theories.Comment: Discussions clarified, typos fixed, table 1 added, figure 4 modified, but the main result unchange

Investigating the relationship between client importance and audit quality: Evidence from TSE

The purpose of this study is to investigate the effect of client importance on audit quality in Tehran Stock Exchange (TSE). The results of previous researches in some countries suggest that the auditor independence may be affected by the economic importance of certain clients, which can affect audit quality. The results of this study, using a sample comprising of 1164 year-company observations during 2005 to 2012 from among listed companies in TSE and using logistic regression analysis showed that there is no significant relationship between the client importance and qualified audit opinion (as a measure of audit quality). In other words, it can be said that the independence and audit quality in Iran's capital market is not affected by the economic importance of clients. The results after controlling other factors that based on the previous researches can affect the qualified audit opinion showed that the probability of revealing qualified audit report has a positive relationship with financial leverage and performance of the previous year and has a negative relationship with the concentration of ownership, the size of the auditor, returns on assets and liquidity ratios

Investigating the relationship between client importance and audit quality: Evidence from TSE

The purpose of this study is to investigate the effect of client importance on audit quality in Tehran Stock Exchange (TSE). The results of previous researches in some countries suggest that the auditor independence may be affected by the economic importance of certain clients, which can affect audit quality. The results of this study, using a sample comprising of 1164 year-company observations during 2005 to 2012 from among listed companies in TSE and using logistic regression analysis showed that there is no significant relationship between the client importance and qualified audit opinion (as a measure of audit quality). In other words, it can be said that the independence and audit quality in Iran's capital market is not affected by the economic importance of clients. The results after controlling other factors that based on the previous researches can affect the qualified audit opinion showed that the probability of revealing qualified audit report has a positive relationship with financial leverage and performance of the previous year and has a negative relationship with the concentration of ownership, the size of the auditor, returns on assets and liquidity ratios

CREATING A SEMI-SUPERVISED DATA MINING MODEL FOR PREDICTING BREAST CANCER RELAPSE

Introduction: Breast cancer is one of the most common types of cancer and malignancy in Iranian women,that recently has been a growing increase. there is always a possibility of recurrence In persons afflicted by thisdisease.In regarding to the complexity of analysis, data mining is among the best solutions that is used to detect or predict cancers. Methods: In this retrospective study, data of 809 patients with breast cancer from center of breast cancer research of Tehran’s Academic Center for Education, Culture and Research (ACECR) and 26 features from each patients were used. In regarding to high number of missing data in this collection, only information of 655 patients and 14 features of each patient were usable. Many features in records have null values, thus as one of data pre-processing and preparing phases, via Auto-Clustering algorithm, the data was divided into 10 clusters and according to dominant values in each cluster for each feature, these null features has been valuing. Data was divided to recurrence and non- recurrence classes. Semi-supervised method has been used in this study. the modeling was performed using labeled data and then a hybrid model for giving label to nonlabled data has been created. For this, data with recurrence lable divided proportional 30 percent for testing and 70 percent for training,and got to decision tree algorithms C5.0, Chaid, Quest, CRT, Autoclassifier as inputs. Then, the model was formed by mixing classifier algorithms with Confidence-Weighting-Voting method for predicting cancer recurrence, and used K-Fold (K=10) method for evaluating created model. Results: The sensitivity of developed hybrid model was 82.93% and its specificity was 93.93%. The precision value of the model is 89.47% and its accuracy is 89.72%. this model mistakenly labelled only 10% of recurrence in patients of breast cancer as non-recurrence. Conclusion: Creating predictive models with an appropriate sensitivity and specificity isimportant since, if the possibility of recurrence is high, could perform special preventive proceedings before its spreading. The false negative percentage is also important in medical prediction models, as it can have very dangerous consequences. In the prediction model presented in this study, the value of this parameter was 10%, and in this regard, this model can be considered acceptabl

Study on seismic behavior of a concrete elevated tank with frame shaped base using SMA damper

Shape memory alloys are considered as novel materials, and during the recent decades, these materials are increasingly used with different applications in various fields of science and engineering. Shaped memory alloys are extensively used in the field of structures and earthquake engineering. These alloys are so expensive, and they are not sufficiently economical to be used in structures, so scholars sought to find a combination usage of these materials along with steel in order to achieve the maximum efficiency. We can make any structure resistant enough against the dynamic loads and forces exerted due to earthquakes, by placing a new member in the structure, so called Damper, which is regarded as a factor with a capability of dissipating the energy. In the present paper, an elevated tank with a capacity of 1500 m3 and frame-shaped base of 37.5 m in height, equipped with SMA damper at the tank-to-beam connection has been analyzed. It should be noted that the SMA material was used on first and seventh storey of the frame-shaped base. A numerical model of the tank was developed using Abaqus software and it was analyzed by applying EL-Centro earthquake record. Then, the best placement states of the SMA dampers indicating a better seismic behaviour were proposed. The findings indicate that an elevated tank with SMA damper has a better seismic behaviour, especially in the upper section of the beam, compared to other models

Upregulation of miR-210 promotes differentiation of mesenchymal stem cells (MSCs) into osteoblasts

Numerous studies indicated that microRNAs are critical in the regulation of cellular differentiation, by controlling the expression of underlying genes. The aim of this study was to investigate the effect of miR-210 upregulation on differentiation of human umbilical cord blood (HUCB)-derived mesenchymal stem cells (MSCs) into osteoblasts. MSCs were isolated from HUCB and confirmed by their adipogenic/osteogenic differentiation and flow cytometric analysis of surface markers. Pre-miR-210 was amplified from human DNA, digested and ligated with plenti-III-mir-green fluorescent protein (GFP) vector, and cloned in STBL4 bacteria. After confirmation with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), the plenti-III-GFP segment bearing pre-miR-210 was transfected into MSCs by electroporation. Two control vectors, pmaxGFP and Scramble, were transfected separately into MSCs. The expression of miR-210 and genes related to osteoblast differentiation, i.e., runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin gene, in the three groups of transfected MSCs was analyzed 0, 7, 14, and 21 days of transfection by quantitative reverse transcription PCR (qRT-PCR). Overexpression of miR-210 was observed in MSCs transfected with miR-210-bearing plasmid, and this was significantly different compared to Scramble group (p < 0.05). Significantly increased expression of Runx2 (at day 7 and 14), ALP and osteocalcin genes (at all time points for both genes) was observed in MSCs with miR-210-bearing plasmid compared to controls. Overall, the overexpression of miR-210 in MSCs led to MSC differentiation into osteoblasts, most probably by upregulating the Runx2, ALP, and osteocalcin genes at different stages of cell differentiation. Our study confirms the potential of miRNAs in developing novel therapeutic strategies that could target regulatory mechanisms of cellular differentiation in various disease states