4 research outputs found
Transforming 3D cartesian into geodetic coordinates
Transformationbetweengeodeticcoordinates(φ,λ,h)(geodeticlattitudeφ,geodeticlongitudeλandellipsoidal/geodeticheight h) and cartesian coordinates has been studied over the years, being a subject of interest in many fields as Geodesy, Aerospace Engineering, Building Engineering, Architecture etc. Most recent works related to this topic present iterative methods for the transformation on a biaxial or triaxial ellipsoid. Our ongoing approach consists in developping a method which directly perform the transformation from 3D cartesian coordinates into geodetic coordinates by using Computer Algebra techniques (mainly Gröbner bases). The celestial bodies considered in our numerical tests are Moon, Io, Europa, Mimas and Enceladus. The method we are developping is going to be implemented in the Computer Algebra System Maple, together with the iterative methods above mentioned, in order to adequately compare their efficiency
Leukemic conversion involving RAS mutations of type 1 CALR-mutated primary myelofibrosis in a patient treated for HCV cirrhosis: a case report
Somatic frameshift mutations in exon 9 of calreticulin (CALR) gene are recognized as disease drivers in primary myelofibrosis (PMF), one of the three classical Philadelphia-negative myeloproliferative neoplasms (MPNs). Type 1/type 1-like CALR mutations particularly confer a favorable prognostic and survival advantage in PMF patients. We report an unusual case of PMF incidentally diagnosed in a 68-year-old woman known with hepatitis C virus (HCV) cirrhosis who developed a progressive painful splenomegaly, without anomalies in blood cell counts. While harboring a type 1 CALR mutation, the patient underwent a leukemic transformation in less than 1 year from diagnosis, with a lethal outcome. Analysis of paired DNA samples from chronic and leukemic phases by a targeted next-generation sequencing (NGS) panel and single-nucleotide polymorphism (SNP) microarray revealed that the leukemic clone developed from the CALR-mutated clone through the acquisition of genetic events in the RAS signaling pathway: an increased variant allele frequency of the germline NRAS Y64D mutation present in the chronic phase (via an acquired uniparental disomy of chromosome 1) and gaining NRAS G12D in the blast phase. SNP microarray analysis showed five clinically significant copy number losses at regions 7q22.1, 8q11.1-q11.21, 10p12.1-p11.22, 11p14.1-p11.2, and Xp11.4, revealing a complex karyotype already in the chronic phase. We discuss how additional mutations, detected by NGS, as well as HCV infection and antiviral therapy, might have negatively impacted this type 1 CALR-mutated PMF. We suggest that larger studies are required to determine if more careful monitoring would be needed in MPN patients also carrying HCV and receiving anti-HCV treatment
Direct transformation from Cartesian into geodetic coordinates on a triaxial ellipsoid
This paper1 presents two new direct symbolic-numerical algorithms for the transformation of Cartesian co ordinates into geodetic coordinates considering the general case of a triaxial reference ellipsoid. The problem in both algorithms is reduced to finding a real positive root of a sixth degree polynomial. The first approach consists of algebraic manipulations of the equations describing the geometry of the problem and the second one uses
Grobner € bases. In order to perform numerical tests and accurately compare efficiency and reliability, our algorithms together with the iterative methods presented by M. Ligas (2012) and J. Feltens (2009) have been implemented in Cþþ. The numerical tests have been accomplished by considering 10 celestial bodies, referenced in the available literature. The obtained results show that our algorithms improve the aforementioned, up-to-date reference, iterative methods, in terms of both efficiency and accuracy.Agencia Estatal de Investigación MTM2017-88796-PMinisterio de Economía, Industria y Competitividad TIN2017-86885-
Molecular Aspects of Hypoxic Stress Effects in Chronic Ethanol Exposure of Neuronal Cells
Experimental models of a clinical, pathophysiological context are used to understand molecular mechanisms and develop novel therapies. Previous studies revealed better outcomes for spinal cord injury chronic ethanol-consuming patients. This study evaluated cellular and molecular changes in a model mimicking spinal cord injury (hypoxic stress induced by treatment with deferoxamine or cobalt chloride) in chronic ethanol-consuming patients (ethanol-exposed neural cultures (SK-N-SH)) in order to explain the clinical paradigm of better outcomes for spinal cord injury chronic ethanol-consuming patients. The results show that long-term ethanol exposure has a cytotoxic effect, inducing apoptosis. At 24 h after the induction of hypoxic stress (by deferoxamine or cobalt chloride treatments), reduced ROS in long-term ethanol-exposed SK-N-SH cells was observed, which might be due to an adaptation to stressful conditions. In addition, the HIF-1α protein level was increased after hypoxic treatment of long-term ethanol-exposed cells, inducing fluctuations in its target metabolic enzymes proportionally with treatment intensity. The wound healing assay demonstrated that the cells recovered after stress conditions, showing that the ethanol-exposed cells that passed the acute step had the same proliferation profile as the cells unexposed to ethanol. Deferoxamine-treated cells displayed higher proliferative activity than the control cells in the proliferation–migration assay, emphasizing the neuroprotective effect. Cells have overcome the critical point of the alcohol-induced traumatic impact and adapted to ethanol (a chronic phenomenon), sustaining the regeneration process. However, further experiments are needed to ensure recovery efficiency is more effective in chronic ethanol exposure