Evolution of Compact Stars and Dark Dynamical Variables

This work is aimed to explore the dark dynamical effects of $f(R,T)$ modified gravity theory on the dynamics of compact celestial star. We have taken the interior geometry as spherical star which is filled with imperfect fluid distribution. The modified field equations are explored by taking a particular form of $f(R,T)$ model, i.e., $f(R,T)=f_1(R)+f_2(R)f_3(T)$. These equations are then utilized to formulate the well-known structure scalars under the dark dynamical effects of this higher order gravity theory. Also, the evolution equations for expansion and shear are formulated with the help of these scalar variables. Further, all this analysis have been made under the condition of constant $R$ and $T$. We found a crucial significance of dark source terms and dynamical variables on the evolution and density inhomogeneity of compact objects.Comment: 18 pages, 4 figures, version accepted for publication in European Physical Journal

Influence of f(R)f(R) Models on the Existence of Anisotropic Self-Gravitating Systems

This paper aims to explore some realistic configurations of anisotropic spherical structures in the background of metric $f(R)$ gravity, where $R$ is the Ricci scalar. The solutions obtained by Krori and Barua are used to examine the nature of particular compact stars with three different modified gravity models. The behavior of material variables is analyzed through plots and the physical viability of compact stars is investigated through energy conditions. We also discuss the behavior of different forces, equation of state parameter, measure of anisotropy and Tolman-Oppenheimer-Volkoff equation in the modeling of stellar structures. The comparison from our graphical representations may provide evidences for the realistic and viable $f(R)$ gravity models at both theoretical and astrophysical scale.Comment: 23 pages, 13 figures, version accepted for publication in European Physical Journal

Existence of Compact Structures in f(R,T)f(R,T) Gravity

The present paper is devoted to investigate the possible emergence of relativistic compact stellar objects through modified $f(R,T)$ gravity. For anisotropic matter distribution, we used Krori and Barura solutions and two notable and viable $f(R,T)$ gravity formulations. By choosing particular observational data, we determine the values of constant in solutions for three relativistic compact star candidates. We have presented some physical behavior of these relativistic compact stellar objects and some aspects like energy density, radial as well as transverse pressure, their evolution, stability, measure of anisotropy and energy conditions.Comment: 27 pages, 13 figures, version accepted for publication in European Physical Journal

Motor imagery classification in Brain Computer Interface (BCI) based on EEG signal by using machine learning technique

This paper focuses on classification of motor imagery in Brain Computer Interface (BCI) by using classifiers from machine learning technique. The BCI system consists of two main steps which are feature extraction and classification. The Fast Fourier Transform (FFT) features is extracted from the electroencephalography (EEG) signals to transform the signals into frequency domain. Due to the high dimensionality of data resulting from the feature extraction stage, the Linear Discriminant Analysis (LDA) is used to minimize the number of dimension by finding the feature subspace that optimizes class separability. Five classifiers: Support Vector Machine (SVM), K-Nearest Neighbors (KNN), Naïve Bayes, Decision Tree and Logistic Regression are used in the study. The performance was tested by using Dataset 1 from BCI Competition IV which consists of imaginary hand and foot movement EEG data. As a result, SVM, Logistic Regression and Naïve Bayes classifier achieved the highest accuracy with 89.09% in AUC measurement

Compact relativistic geometries in f(R,G)f(R,G) gravity

One of the possible potential candidates for describing the universe's rapid expansion is modified gravity. In the framework of the modified theory of gravity $f(R,G)$, the present work features the materialization of anisotropic matter, such as compact stars. Specifically, to learn more about the physical behavior of compact stars, the radial, and tangential pressures as well as the energy density of six stars namely $Her X-1$, $SAXJ1808.4-3658$, $4U1820-30$, $PSR J 1614 2230$, $VELA X-1$, and $Cen X-3$ are calculated. Herein, the modified theory of gravity $f(R,G)$ is disintegrated into two parts i.e. the $\tanh$ hyperbolic $f(R)$ model and the three different $f(G)$ model. The study focuses on graphical analysis of compact stars wherein the stability aspects, energy conditions, and anisotropic measurements are mainly addressed. Our calculation revealed that, for the positive value of parameter n of the model $f(G)$, all the six stars behave normally.Comment: Some changes have been made. " To appear in International Journal of Geometric Methods in Modern Physics

Reflections on local community identity by evaluating heritage sustainability protection in Jugra, Selangor, Malaysia

The purpose of this study is to evaluate the value derived by the local community from cultural heritage and natural heritage in Jugra, Kuala Langat, as it has the potential to be a recognized heritage tourism site. The quantitative approach was used by conducting a survey study. A total of 392 respondents among the local community were selected through a purposive sampling technique. The collected data were processed with SPSS software and analyzed using cross tabulation analysis. Then, several hypotheses were tested using AMOS software. The result showed that Jugra’s unique heritage elements positively influenced the respondent’s willingness to accept and fund its tourism development. Socioeconomic factors also influenced the respondents’ disposition to preserve heritage. The findings revealed that there was priceless value when respondents agreed with the development, although they had never visited the heritage sites. Their physical, economic, and social valuation made them proud of the heritage, as it is a reflection of their identity. This study also aims to emphasize the role of local community as one of the stakeholders, as they should also be able to benefit from tourism development. All these would help boost the tourism industry, particularly through the archaeo-tourism and eco-tourism perspectives

The effect of Berberine on weight loss in order to prevent obesity: A systematic review

This study provides a critical overview of experimental studies in vitro, in humans, and in animals that evaluated the efficacy of Berberine and its effect on management of obesity and the related metabolic consequences. As a result of this review, we summarized the effects of Berberine in different models and the related mechanism of actions. In preclinical models, Berberine demonstrates that it affects gut microbiota by reducing diversity of microbes starting at a dosage of 100 mg/kg/day. Moreover, in animal models, Berberine explicates an action on glucose through the inhibition of α-glycosidase at a dose of 200 mh/kg/day. Berberine is also known to be effective against differentiation of adipocytes through a decrease in LXRs, PPARs, and SREBPs expression at 150 mg/kg/day. Other mechanism ascribed to Berberine are related to its inhibition of hepatic gluconeogenesis through the Phospheoenolpyruvate carboxykinase (PEPCK), Glucose-6-phosphate (G6Pase) and AMP-activated protein kinase (AMPK). Furthermore, Berberine (associated to Red Yeast Rice) is effective in decreasing lipid levels in rats, which consequently lowers the change of weight gain at dosage of 40 mg/kg to 380 mg/kg/day. All the above preclinical data are confirmed in human studies where Berberine can modulate the diversity of gut microbes at the dose of 500 mg/day. In addition, Berberine is found to have a beneficial impact on gene regulation for the absorption of cholesterol at a daily dose of 300 mg in humans, an amelioration on glucose accumulation at 1.0 g daily dose was also observed. For all these reasons, this review gives an important good account of the impact of Berberine in obesity treatment and prevention