Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Modeling of asteroid spectra – M4AST

Abstract: Context. The interpretation of asteroid spectra provides the basis for determining the chemical composition and physical process that modified the surface of the asteroids. The increasing number of asteroid spectral measurements has lead to well-developed methods for analyzing asteroid spectra. There is however no centralized database for all the published data and a set of standard routines is also required. Aims. We present a public software tool that combines both data archives and analyses of asteroid spectra. Methods. Our project M4AST (Modeling for asteroids) consists of an asteroid spectral database and a set of applications for analyzing asteroid spectra. These applications cover aspects related to taxonomy, curve matching with laboratory spectra, space weathering models, and mineralogical diagnosis. Results. M4AST project is fully available via a web interface. The database contains around 2700 spectra that can be either processed in M4AST and/or downloaded. The paper presents the algorithms we developed for spectral analyses based on existing methods. The robustness of routines is proven by the solutions found for spectra of three different asteroids: (9147) Kourakuen, (99 942) Apophis, and (175 706) 1996 FG3. The available results confirm those in the literature. M4AST applications can also be used to characterize any new asteroid spectra. Conclusions. M4AST is a robust and reliable tool dedicated to asteroid spectra.

Regulation of Nox enzymes expression in vascular pathophysiology: Focusing on transcription factors and epigenetic mechanisms.

Abstract: NADPH oxidases (Nox) represent a family of hetero-oligomeric enzymes whose exclusive biological function is the generation of reactive oxygen species (ROS). Nox-derived ROS are essential modulators of signal transduction pathways that control key physiological activities such as cell growth, proliferation, migration, differentiation, and apoptosis, immune responses, and biochemical pathways. Enhanced formation of Nox-derived ROS, which is generally associated with the up-regulation of different Nox subtypes, has been established in various pathologies, namely cardiovascular diseases, diabetes, obesity, cancer, and neurodegeneration. The detrimental effects of Nox-derived ROS are related to alterations in cell signalling and/or direct irreversible oxidative damage of nucleic acids, proteins, carbohydrates, and lipids. Thus, understanding of transcriptional regulation mechanisms of Nox enzymes have been extensively investigated in an attempt to find ways to counteract the excessive formation of Nox-derived ROS in various pathological states. Despite the numerous existing data, the molecular pathways responsible for Nox up-regulation are not completely understood. This review article summarizes some of the recent advances and concepts related to the regulation of Nox expression in the vascular pathophysiology. It highlights the role of transcription factors and epigenetic mechanisms in this process. Identification of the signalling molecules involved in Nox up-regulation, which is associated with the onset and development of cardiovascular dysfunction may contribute to the development of novel strategies for the treatment of cardiovascular diseases.

Finite-difference lattice Boltzmann model with flux limiters for liquid-vapor systems.

Abstract: In this paper we apply a finite difference lattice Boltzmann model to study the phase separation in a two-dimensional liquid-vapor system. Spurious numerical effects in macroscopic equations are discussed and an appropriate numerical scheme involving flux limiter techniques is proposed to minimize them and guarantee a better numerical stability at very low viscosity. The phase separation kinetics is investigated and we find evidence of two different growth regimes depending on the value of the fluid viscosity as well as on the liquid-vapor ratio.