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Search Results: 1 - 10 of 4352 matches for " Sijo Sebastian "
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Kadomstev-Petviashvilli-Burgers (KPB) Equation in a Five Component Cometary Plasma with Kappa Described Electrons and Ions  [PDF]
Manesh Michael, Sreekala Gopinathan, Sijo Sebastian, Neethu T. Willington, Anu Varghese, Renuka Gangadharan, Chandu Venugopal
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.311171
Abstract: We investigate the existence of Ion-Acoustic solitary/shock waves in a five component cometary plasma consisting of positively and negatively charged oxygen ions, kappa described hydrogen ions, hot electrons and cold electrons. The KPB equation is derived for the system; its solution is plotted for different kappa values, as well as for the temperature ratios of ions. It is found that the amplitude of solitary structure increases with increasing kappa values and negatively charged oxygen ion densities. As the temperature of the positively charged oxygen ions increases, the amplitude of solitary wave also increases. We have also studied the dependence of coefficients of the KPB equation on physical parameters relevant to comet Halley.
Ion-Acoustic Instabilities in a Multi-Ion Plasma
Noble P. Abraham,Sijo Sebastian,G. Sreekala,R. Jayapal,C. P. Anilkumar,Venugopal Chandu
Journal of Astrophysics , 2013, DOI: 10.1155/2013/838534
Abstract: We have, in this paper, studied the stability of the ion-acoustic wave in a plasma composed of hydrogen, positively and negatively charged oxygen ions, and electrons, which approximates very well the plasma environment around a comet. Modelling each cometary component ( , , and ) by a ring distribution, we find that ion-acoustic waves can be generated at frequencies comparable to the hydrogen ion plasma frequency. The dispersion relation has been solved both analytically and numerically. We find that the ratio of the ring speed ( ) to the thermal spread ( ts) modifies the dispersion characteristics of the ion-acoustic wave. The contrasting behaviour of the phase velocity of the ion-acoustic wave in the presence of ions for ts (and vice versa) can be used to detect the presence of negatively charged oxygen ions and also their thermalization. 1. Introduction Low-frequency electrostatic or longitudinal ion density waves are one of the most fundamental of oscillations in a plasma [1, 2]. In the long-wavelength limit, the ions provide the inertia with the electrons as the source of the restoring force [1]. Ion-acoustic waves also exhibit strong nonlinear properties and are highly Landau damped unless , where and are, respectively, the ion and electron temperatures [3–5]. These waves have been observed in both space and laboratory plasmas; they have thus been extensively studied in many types of high-temperature laboratory plasmas [4, 6]. The waves have been invoked to explain wave characteristics observed in Earth’s ionosphere [7] and transport in the solar wind, corona, chromosphere [8], and comets [9]. In general a cometary environment contains new born hydrogen and heavier ions, with relative densities depending on the distance from the nucleus. Previous studies have concentrated on positively charged oxygen as the heavier ion species [10]. However, Giotto’s observations of the inner coma of comet Halley showed that a new component, namely, negatively charged cometary ions was present, in addition to the usual thermal electrons and ions, fast cometary pickup ions, and so forth, [11]. These negative ions were observed in three broad mass peaks at 7–19, 22–65, and 85–110 amu with being identified unambiguously [11]. A popular model of a cometary environment is the solar wind plasma environment permeated by dilute, drifting ring distribution of electrons and ions with finite thermal spreads [10]. Instabilities driven by an electron velocity ring distributions have been studied by many authors [12–14]. However, ion ring distributions are more important
Negatively Charged Oxygen Ions as a Plasma Diagnostic Tool: Application to Comets  [PDF]
Sreekala Gopinathan, Sijo Sebastian, Noble Abraham, Savithri Devi, Venugopal Chandu, Renuka Gangadharan
Open Access Library Journal (OALib Journal) , 2014, DOI: 10.4236/oalib.1100570
Abstract: We study the stability of the ion-acoustic (IA) wave in a collisional plasma composed of hydrogen, positively and negatively charged oxygen ions, electrons and neutral atoms. This composition approximates very well the plasma environment around a comet. A solution of the dispersion relation yields a frequency for the IA wave at around the hydrogen plasma frequency. The growth/ damping rate is sensitively dependent on the ring parameters u⊥s (the ring speed) and v ts (the thermal spread). The growth rate of the wave, which decreases with increasing collisional frequencies, is larger when u⊥s < v ts . In the presence of negatively charged oxygen ions, the phase and group velocities of the IA wave behave in a contrasting manner when u⊥s < v ts (and viceversa). We propose that this behaviour be exploited as a diagnostic tool for the detection of these ions and also their thermalization.
Garlic extracts prevent oxidative stress, hypertrophy and apoptosis in cardiomyocytes: a role for nitric oxide and hydrogen sulfide
Louis Xavier,Murphy Ryan,Thandapilly Sijo,Yu Liping
BMC Complementary and Alternative Medicine , 2012, DOI: 10.1186/1472-6882-12-140
Abstract: Background In ancient times, plants were recognized for their medicinal properties. Later, the arrival of synthetic drugs pushed it to the backstage. However, from being merely used for food, plants are now been widely explored for their therapeutic value. The current study explores the potential of skin and flesh extracts from a hard-necked Rocambole variety of purple garlic in preventing cardiomyocyte hypertrophy and cell death. Methods Norepinephrine (NE) was used to induce hypertrophy in adult rat cardiomyocytes pretreated with garlic skin and flesh extracts. Cell death was measured as ratio of rod to round shaped cardiomyocytes. Fluorescent probes were used to measure apoptosis and oxidative stress in cardiomyocytes treated with and without extracts and NE. Pharmacological blockade of nitric oxide (NO) and hydrogen sulfide (H2S) were used to elucidate the mechanism of action of garlic extracts. Garlic extract samples were also tested for alliin and allicin concentrations. Results Exposure of cardiomyocytes to NE induced an increase in cell size and cell death; this increase was significantly prevented upon treatment with garlic skin and flesh extracts. Norepinephrine increased apoptosis and oxidative stress in cardiomyocytes which was prevented upon pretreatment with skin and flesh extracts; NO, and H2S blockers significantly inhibited this beneficial effect. Allicin and alliin concentration were significantly higher in garlic flesh extract when compared to the skin extract. Conclusion These results suggest that both skin and flesh garlic extracts are effective in preventing NE induced cardiomyocyte hypertrophy and cell death. Reduction in oxidative stress may also play an important role in the anti-hypertrophic and anti-apoptotic properties of garlic extracts. These beneficial effects may in part be mediated by NO and H2S.
Cornu cutaneum at an unusual site
Tauro Leo,Martis John Joseph,John Sijo,K Prem Kumar
Indian Journal of Plastic Surgery , 2006,
Abstract: Cutaneous horn (cornu cutaneum) is a clinical diagnosis referring to a conical projection above the surface of the skin that resembles a miniature horn. The base of the horn may be flat, nodular or crateriform. The horn is composed of compacted keratin. Various histologic lesions have been documented at the base of the keratin mound and histological confirmation is often necessary to rule out malignant changes. Tenderness at the base of the lesion and lesions of larger size favour malignancy. Malignancy is present in 16-20% of the cases with squamous cell carcinoma being the most common type. We report a young male patient with a keratin horn on the right index finger tip.
Time-Dependent Ferrofluid Dynamics in Symmetry Breaking Transverse  [PDF]
Sebastian Altmeyer
Open Journal of Fluid Dynamics (OJFD) , 2013, DOI: 10.4236/ojfd.2013.32015
Abstract: We investigate the Taylor-Couette flow of a rotating ferrofluid under the influence of symmetry breaking transverse magnetic field in counter-rotating small-aspect-ratio setup. We find only changing the magnetic field strength can drive the dynamics from time-periodic limit-cycle solution to time-independent steady fixed-point solution and vice versa. Thereby both solutions exist in symmetry related offering mode-two symmetry with left-or right-winding characteristics due to finite transverse magnetic field. Furthermore the time-periodic limit-cycle solutions offer alternately stroboscoping both helical left-and right-winding contributions of mode-two symmetry. The Navier-Stokes equations are solved with a second order time splitting method combined with spatial discretization of hybrid finite difference and Galerkin method.
Structure of Relatively Accelerating Universe  [PDF]
Aloysius Sebastian
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.41015
Abstract:

This article is about the structure of expanding universe. Here I am trying to create a structural model of universe according to my thoughts. Studies showthat universe is accelerating its rate of expansion. Here I am trying to get some conclusions according to my thoughts. In my opinion, our universe is under a gravitational frame with all the matters in it. In this gravitational frame of universe we can consider our universe as a closed system and the empty space outside the frame as an open system. There are two possibilities we can find. One is relative motion of the objects inside the frame. By this way we can feel the universe is accelerating its expansion, but it is not. Another one is the vacuum energy absorption and negative pressure inside the frame. According to this thought, we can say that universe is accelerating and it can continue its motion at present conditions on it, even the force created by the big bang is decreasing. The other point is that, once the absorbed vacuum can create a negative pressure inside the frame, there is no need for the concept of dark energy in our universe [1]. According to this model, negative pressure inside the frame will be created by the absorbed vacuum from the space. So the

Multicenter Experience with Nonischemic Multiport Laparoscopic and Laparoendoscopic Single-Site Partial Nephrectomy Utilizing Bipolar Radiofrequency Ablation Coagulator
Wassim M. Bazzi,Mohamad E. Allaf,Jared Berkowitz,Hany N. Atalah,Sijo Parekattil,Ithaar H. Derweesh
Diagnostic and Therapeutic Endoscopy , 2011, DOI: 10.1155/2011/636537
Abstract: Objective. To investigate feasibility of multiport and laparoendoscopic single-site (LESS) nonischemic laparoscopic partial nephrectomy (NI-LPN) utilizing bipolar radiofrequency coagulator. Methods. Multicenter retrospective review of 60 patients (46 multiport/14 LESS) undergoing NI-LPN between 4/2006 and 9/2009. Multiport and LESS NI-LPN utilized Habib 4X bipolar radiofrequency coagulator to form a hemostatic zone followed by nonischemic tumor excision and renorrhaphy. Demographics, tumor/perioperative characteristics, and outcomes were analyzed. Results. 59/60 (98.3%) successfully underwent NI-LPN. Mean tumor size was 2.35?cm. Mean operative time was 160.0 minutes. Mean estimated blood loss was 131.4?mL. Preoperative/postoperative creatinine (mg/dL) was 1.02/1.07 ( ). All had negative margins. 12 (20%) patients developed complications. 3 (5%) developed urine leaks. No differences between multiport and LESS-PN were noted as regards demographics, tumor size, outcomes, and complications. Conclusion. Initial experience demonstrates that nonischemic multiport and LESS-PN is safe and efficacious, with excellent short-term preservation of renal function. Long-term data are needed to confirm oncological efficacy. 1. Introduction In 2009, there were approximately 57,760 new cases of kidney cancer with 12,980 deaths in the United States [1]. Increasing incidence of small renal masses (SRMs) [2], along with an increased awareness of the metabolic consequences of removal of normally functioning renal tissue by radical nephrectomy [3–7], has led to a paradigm shift of surgical management with greater emphasis on nephron sparing and minimally invasive approaches [8, 9]. While laparoscopic partial nephrectomy (LPN) is becoming recognized as a standard for management of SRM, concerns regarding prolonged warm ischemia times continue to forestall its widespread adoption [8, 9]. By combining working trocar sites and the eventual extraction site into a single location, laparoendoscopic single-site (LESS) surgery further limits the invasiveness of laparoscopy and may enhance advantages associated with traditional laparoscopy. Reduced incisional morbidity and improved cosmesis have largely sparked a growing interest in the utilization of this technique to perform upper tract urologic surgery [10–13]. Recent reports have demonstrated the feasibility of LESS partial nephrectomy [12, 13]. The Habib 4X (Angiodynamics, Queensbury, NY) is a bipolar radiofrequency coagulation device which has been used for nonischemic resections of the liver [14] as well as kidney [15]. We
Entanglement Manipulation in a Quantum Chaotic Optical Fiber by Modifying its Geometry
Sijo K. Joseph,Juan Sabuco,Lock Yue Chew,Miguel A. F. Sanjuán
Physics , 2015,
Abstract: The effect of boundary deformation on the non-separable entanglement which appears in the classical elec- tromagnetic field is considered. A quantum chaotic billiard geometry is used to explore the influence of a mechanical modification of the optical fiber cross-sectional geometry on the production of non-separable entan- glement within classical fields. For the experimental realization of our idea, we propose an optical fiber with a cross section that belongs to the family of Robnik chaotic billiards. Our results show that a modification of the fiber geometry from a regular to a chaotic regime can enhance the transverse mode entanglement. Our proposal can be realized in a very simple experimental set-up which consists of a specially designed optical fiber where non-entangled light enters at the input end and entangled light propagates out at the output end after interacting with a fiber boundary that is known to generate chaotic behavior.
The Post-Transcriptional mRNA Editing Analysis of cox3 Mitochondrial Gene in Fern Asplenium nidus Reveals Important Features  [PDF]
Sebastian Panarese, Guglielmo Rainaldi
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.24063
Abstract: In the mitochondria and chloroplasts of flowering plants (angiosperms), transcripts of protein-coding genes are altered after synthesis so that their final primary nucleotide sequence differs from that of the corresponding DNA sequence. This posttranscriptional mRNA editing consists almost exclusively of C-to-U substitutions (direct) and less frequently of U-to-C substitution (reverse). Editing occurs predominantly within coding regions, mostly at isolated C residues, and usually at first or second positions of codons, thereby almost always changing the amino acid from that specified by the unedited codon. Editing may also create initiation and termination codons. The effect of C-to-U RNA editing in plants is to make proteins encoded by plant organelles more similar in sequence to their non plant homologs, then specific C-to- U editing events are essential for the production of functional plant mitochondrial proteins. Our attention has been devoted to the study of the mRNA editing in cox3 mitochondrial gene of fern Asplenium nidus. This study reveals the extreme importance of both C-to-U and U-to-C substitutions for protein expression.
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