The linear stability of massive extreme Pop I stars at the main sequence is investigated with a f... more The linear stability of massive extreme Pop I stars at the main sequence is investigated with a full nonadiabatic treatment. Contrary to earlier beliefs these stars become vibrationally unstable only beyond a critical mass as high as 440 M⊙ at the main sequence.
Finite amplitude pulsations of realistic stellar models are analyzed within the framework of a pr... more Finite amplitude pulsations of realistic stellar models are analyzed within the framework of a promising asymptotic perturbation approach and the results are compared with those of numerical hydrodynamic studies.
Angiogenesis is an important adaptation mechanism of the blood vessels to the changing requiremen... more Angiogenesis is an important adaptation mechanism of the blood vessels to the changing requirements of the body during development, aging, and wound healing. Angiogenesis allows existing blood vessels to form new connections or to reabsorb existing ones. Blood vessels are composed of a layer of endothelial cells (ECs) covered by one or more layers of mural cells (smooth muscle cells or pericytes). We constructed a computational Boolean model of the molecular regulatory network involved in the control of angiogenesis. Our model includes the ANG/TIE, HIF, AMPK/mTOR, VEGF, IGF, FGF, PLCγ/Calcium, PI3K/AKT, NO, NOTCH, and WNT signaling pathways, as well as the mechanosensory components of the cytoskeleton. The dynamical behavior of our model recovers the patterns of molecular activation observed in Phalanx, Tip, and Stalk ECs. Furthermore, our model is able to describe the modulation of EC behavior due to extracellular micro-environments, as well as the effect due to loss- and gain-of-f...
In recent years there has been increasing interest in understanding the role that Very Massive St... more In recent years there has been increasing interest in understanding the role that Very Massive Stars (VMS) could play in the cosmological scenario. Star formation and accretion calculations suggest that the proposed first stars are VMS rather than lower mass stars. ...
Communications in Computer and Information Science, 2016
The results described in this chapter are part of a larger project. The long term goal of this pr... more The results described in this chapter are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain arteriovenous malformations. First, we need to build a model of the vascular architecture of each specific patient, our approach to build these models is described in this chapter. Later we will use the model of the vascular architecture to simulate the velocity and pressure gradients of the blood flowing within the vessels, and the stresses on the blood vessel walls, before and after treatment. We are developing a program to describe each blood vessel as a parametric curve, where each point within this curve includes a normal vector that points in the opposite direction of the pressure gradient. The shape of the cross section of the vessel in each point is described as an ellipse. Our program is able to describe the geometry of a blood vessel using as an input a cloud of dots. The program allows us to model any blood vessel, and other tubular structures.
The linear stability of massive extreme Pop I stars at the main sequence is investigated with a f... more The linear stability of massive extreme Pop I stars at the main sequence is investigated with a full nonadiabatic treatment. Contrary to earlier beliefs these stars become vibrationally unstable only beyond a critical mass as high as 440 M⊙ at the main sequence.
Finite amplitude pulsations of realistic stellar models are analyzed within the framework of a pr... more Finite amplitude pulsations of realistic stellar models are analyzed within the framework of a promising asymptotic perturbation approach and the results are compared with those of numerical hydrodynamic studies.
Angiogenesis is an important adaptation mechanism of the blood vessels to the changing requiremen... more Angiogenesis is an important adaptation mechanism of the blood vessels to the changing requirements of the body during development, aging, and wound healing. Angiogenesis allows existing blood vessels to form new connections or to reabsorb existing ones. Blood vessels are composed of a layer of endothelial cells (ECs) covered by one or more layers of mural cells (smooth muscle cells or pericytes). We constructed a computational Boolean model of the molecular regulatory network involved in the control of angiogenesis. Our model includes the ANG/TIE, HIF, AMPK/mTOR, VEGF, IGF, FGF, PLCγ/Calcium, PI3K/AKT, NO, NOTCH, and WNT signaling pathways, as well as the mechanosensory components of the cytoskeleton. The dynamical behavior of our model recovers the patterns of molecular activation observed in Phalanx, Tip, and Stalk ECs. Furthermore, our model is able to describe the modulation of EC behavior due to extracellular micro-environments, as well as the effect due to loss- and gain-of-f...
In recent years there has been increasing interest in understanding the role that Very Massive St... more In recent years there has been increasing interest in understanding the role that Very Massive Stars (VMS) could play in the cosmological scenario. Star formation and accretion calculations suggest that the proposed first stars are VMS rather than lower mass stars. ...
Communications in Computer and Information Science, 2016
The results described in this chapter are part of a larger project. The long term goal of this pr... more The results described in this chapter are part of a larger project. The long term goal of this project is to help physicians predict the hemodynamic changes, and associated risks, caused by different treatment options for brain arteriovenous malformations. First, we need to build a model of the vascular architecture of each specific patient, our approach to build these models is described in this chapter. Later we will use the model of the vascular architecture to simulate the velocity and pressure gradients of the blood flowing within the vessels, and the stresses on the blood vessel walls, before and after treatment. We are developing a program to describe each blood vessel as a parametric curve, where each point within this curve includes a normal vector that points in the opposite direction of the pressure gradient. The shape of the cross section of the vessel in each point is described as an ellipse. Our program is able to describe the geometry of a blood vessel using as an input a cloud of dots. The program allows us to model any blood vessel, and other tubular structures.
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