A Comparative Analysis of Rate of Convergence For Linear And Quadratic Approximations in N-R Method

Ndash Raphson (N-R) Method is commonly used in the solution of algebraic equations and transcendental equations. Using Taylorrsquos theorem for expansion of functions, generally expansion is truncated as linear approximation. In this research work, expansion of function is truncated as quadratic approximation and then a comparative analysis was done for linear and quadratic approximations.nbs

Improved Survival with the Patients with Variceal Bleed

Variceal hemorrhage is a major cause of death in patients with cirrhosis. Over the past two decades new treatment modalities have been introduced in the management of acute variceal bleeding (AVB) and several recent studies have suggested that the outcome of patients with cirrhosis and AVB has improved. Improved supportive measures, combination therapy which include early use of portal pressure reducing drugs with low rates of adverse effects (somatostatin, octerotide or terlipressin) and endoscopic variceal ligation has become the first line treatment in the management of AVB. Short-term antibiotic prophylaxis, early use of lactulose for prevention of hepatic encephalopathy, application of early transjugular intrahepatic portasystemic shunts (TIPS), fully covered self-expandable metallic stent in patients for AVB may be useful in those cases where balloon tamponade is considered. Early and wide availability of liver transplantation has changed the armamentarium of the clinician for patients with AVB. High hepatic venous pressure gradient (HVPG) >20 mmHg in AVB has become a useful predictor of outcomes and more aggressive therapies with early TIPS based on HVPG measurement may be the treatment of choice to reduce mortality further

Sinomenine inhibits microglial activation by Aβ and confers neuroprotection

Abstract Background Neuroinflammation is an important contributor to the development of neurodegenerative diseases, including Alzheimer's disease. Thus, there is a keen interest in identifying compounds, especially from herbal sources, that can inhibit neuroinflammation. Amyloid-β (Aβ) is a major component of the amyloid plaques present in the brains of Alzheimer's disease patients. Here, we examined whether sinomenine, present in a Chinese medicinal plant, prevents oligomeric Aβ-induced microglial activation and confers protection against neurotoxicity. Methods Oligomeric amyloid-β was prepared from Aβ(1-42). Intracellular reactive oxygen species production was determined using the dye 2',7'-dichlorodihydrofluorescin diacetate. Nitric oxide level was assessed using the Griess reagent. Flow cytometry was used to examine the levels of inflammatory molecules. BV2-conditioned medium was used to treat hippocampal cell line (HT22) and primary hippocampal cells in indirect toxicity experiments. Toxicity was assessed using MTT reduction and TUNEL assays. Results We found that sinomenine prevents the oligomeric Aβ-induced increase in levels of reactive oxygen species and nitric oxide in BV2 microglial cells. In addition, sinomenine reduces levels of Aβ-induced inflammatory molecules. Furthermore, sinomenine protects hippocampal HT22 cells as well as primary hippocampal cells from indirect toxicity mediated by Aβ-treated microglial cells, but has no effect on Aβ-induced direct toxicity to HT22 cells. Finally, we found that conditioned medium from Aβ-treated BV2 cells contains increased levels of nitric oxide and inflammatory molecules, but the levels of these molecules are reduced by sinomenine. Conclusions Sinomenine prevents oligomeric Aβ-induced microglial activation, and confers protection against indirect neurotoxicity to hippocampal cells. These results raise the possibility that sinomenine may have therapeutic potential for the treatment of Alzheimer's diseases as well as other diseases that involve neuroinflammation.</p

Sectoral portfolio optimization by judicious selection of financial ratios via PCA

Embedding value investment in portfolio optimization models has always been a challenge. In this paper, we attempt to incorporate it by first employing principal component analysis (PCA) sector wise to filter out dominant financial ratios from each sector and thereafter, use the portfolio optimization model incorporating second order stochastic dominance (SSD) criteria to derive the final optimal investment. We consider a total of 11 well known financial ratios corresponding to each sector representing four categories of ratios, namely liquidity, solvency, profitability, and valuation. PCA is then applied sector wise over a period of 10 years from April 2004 to March 2014 to extract dominant ratios from each sector in two ways, one from the component solution and other from each category on the basis of their communalities. The two step Sectoral Portfolio Optimization (SPO) model integrating the SSD criteria in constraints is then utilized to build an optimal portfolio. The strategy formed using the former extracted ratios is termed as PCA-SPO(A) and the latter one as PCA-SPO(B). The results obtained from the proposed strategies are compared with the SPO model and two nominal SSD models, with and without financial ratios for computational study. Empirical performance of proposed strategies is assessed over the period of 6 years from April 2014 to March 2020 using a rolling window scheme with varying out-of-sample time line of 3, 6, 9, 12 and 24 months for S&P BSE 500 market. We observe that the proposed strategy PCA-SPO(B) outperforms all other models in terms of downside deviation, CVaR, VaR, Sortino ratio, Rachev ratio, and STARR ratios over almost all out-of-sample periods. This highlights the importance of value investment where ratios are carefully selected and embedded quantitatively in portfolio selection process.Comment: 26 pages, 12 table

Remote Raman Spectroscopy of Minerals at Elevated Temperature Relevant to Venus Exploration

We have used a remote time-resolved telescopic Raman system equipped with 532 nm pulsed laser excitation and a gated intensified CCD (ICCD) detector for measuring Raman spectra of a number of minerals at high temperature to 970 K. Remote Raman measurements were made with samples at 9-meter in side a high-temperature furnace by gating the ICCD detector with 2 micro-sec gate to minimize interference from blackbody emission from mineral surfaces at high temperature as well as interference from ambient light. A comparison of Raman spectra of gypsum (CaSO4.2H2O), dolomite (CaMg(CO3)2), and olivine (Mg2Fe2-xSiO4), as a function of temperature shows that the Raman lines remains sharp and well defined even in the high-temperature spectra. In the case of gypsum, Raman spectral fingerprints of CaSO4.H2O at 518 K were observed due to dehydration of gypsum. In the case of dolomite, partial mineral dissociation was observed at 973 K at ambient pressure indicating that some of the dolomite might survive on Venus surface that is at approximately 750 K and 92 atmospheric pressure. Time-resolved Raman spectra of low clino-enstatite (MgSiO3) measured at 75 mm from the sample in side the high-temperature furnace also show that the Raman lines remains sharp and well defined in the high temperature spectra. These high-temperature remote Raman spectra of minerals show that time-resolved Raman spectroscopy can be used as a potential tool for exploring Venus surface mineralogy at shorter (75 mm) and long (9 m) distances from the samples both during daytime and nighttime. The remote Raman system could also be used for measuring profiles of molecular species in the dense Venus atmosphere during descent as well as on the surface

Successful pregnancy in a patient with Ebstein’s anomaly: a case report and review of literature

Ebstein’s anomaly, a rare congenital heart disease, has an extremely variable natural history, depending on variety of pathological features. We here describe a case of a patient with Ebstein’s anomaly who had an uneventful vaginal delivery of a healthy term baby. The anomaly was diagnosed during childhood, was not associated with other cardiac anomalies, cyanosis or pre-excitation and the echocardiographic degree of severity was low

STRUCTURAL AND OPTICAL PROPERTIES OF ZnS NANOPARTICLES SYNTHESIZED BY MICROWAVE IRRADIATION METHOD

ZnS nanoparticles were synthesized by Microwave assisted irradiation method. The obtained ZnS nanoparticles were characterized by XRD, SEM and UV-Vis spectroscopy. XRD characterization of the samples were taken which verify the crystalline form of the samples and also the average size of the nanocrystallites were measured by DebyeScherrer formula as per the XRD spectrum, which was found to be around 6 nm. The surface morphology of the ZnS nanocrystallites was taken by Scanning Electron Microscopy. The UV-Visible absorption spectra of the nanocrystallites were taken and the optical bandgap of the ZnS nanocrystals were found to be 3.76 eV

Hypertrophic pachymeningitis: a rare manifestation of IgG4 related disease

Hypertrophic pachymeningitis (HP) is a rare form of diffuse inflammatory disease that causes thickening of the dura mater. It can involve the cranial or the spinal dura or both. An increasingly well-known symptom of IgG4-related illness, a fibroinflammatory syndrome that may affect almost any organ, is IgG4-related hypertrophic pachymeningitis (IgG4-RHP). It is estimated that IgG4-RHP may account for a high proportion of cases of hypertrophic pachymeningitis once considered idiopathic. Contrast magnetic resonance imaging (MRI) shows pachymeningeal enhancement. Serum IgG4 levels may be elevated but are normal in most patients. However, most patients have elevated cerebrospinal fluid (CSF) IgG4 index. Hence, CSF IgG4 index could serve as a less invasive diagnostic marker of IgG4-RHP. Confirmation of diagnosis is by meningeal biopsy that shows swirling “storiform” fibrosis with lymphocytic infiltrates, obliterate phlebitis and IgG4 positive plasma cells. This case highlights the diagnostic dilemma of IgG4-RHP as gold standard of diagnosis is meningeal biopsy which has many of its own limitations. CSF IgG4 index could be an alternate option for meningeal biopsy when the procedure is contraindicated or uninformative

Studies of Minerals, Organic and Biogenic Materials through Time-Resolved Raman Spectroscopy

A compact remote Raman spectroscopy system was developed at NASA Langley Research center and was previously demonstrated for its ability to identify chemical composition of various rocks and minerals. In this study, the Raman sensor was utilized to perform time-resolved Raman studies of various samples such as minerals and rocks, Azalea leaves and a few fossil samples. The Raman sensor utilizes a pulsed 532 nm Nd:YAG laser as excitation source, a 4-inch telescope to collect the Raman-scattered signal from a sample several meters away, a spectrograph equipped with a holographic grating, and a gated intensified CCD (ICCD) camera system. Time resolved Raman measurements were carried out by varying the gate delay with fixed short gate width of the ICCD camera, allowing measurement of both Raman signals and fluorescence signals. Rocks and mineral samples were characterized including marble, which contain CaCO3. Analysis of the results reveals the short (approx.10-13 s) lifetime of the Raman process, and shows that Raman spectra of some mineral samples contain fluorescence emission due to organic impurities. Also analyzed were a green (pristine) and a yellow (decayed) sample of Gardenia leaves. It was observed that the fluorescence signals from the green and yellow leaf samples showed stronger signals compared to the Raman lines. Moreover, it was also observed that the fluorescence of the green leaf was more intense and had a shorter lifetime than that of the yellow leaf. For the fossil samples, Raman shifted lines could not be observed due the presence of very strong short-lived fluorescence

Standoff Ultra-Compact Micro-Raman Sensor for Planetary Surface Explorations

We report the development of an innovative standoff ultracompact micro-Raman instrument that would solve some of the limitations of traditional micro-Raman systems to provide a superior instrument for future NASA missions. This active remote sensor system, based on a 532 nm laser and a miniature spectrometer, is capable of inspection and identification of minerals, organics, and biogenic materials within several centimeters (220 cm) at a high 10 m resolution. The sensor system is based on inelastic (Raman) light scattering and laser-induced fluorescence. We report on micro-Raman spectroscopy development and demonstration of the standoff Raman measurements by acquiring Raman spectra in daylight at a 10 cm target distance with a small line-shaped laser spot size of 17.3 m (width) by 5 mm (height)