150 research outputs found
Simulating an Airborne Lidar Bathymetry (ALB) System
This study’s focus is on the horizontal and vertical uncertainties associated with ALB measurements due to scattering through the water column. A lidar simulator was constructed and we present its design and preliminary results
Macro-Economic Variables and Stock Market Performance: Empirical Evidence from Colombo Stock Exchange
Stock market performance is considered as a significant indicator of financial and economic circumstances of a country. In a nutshell, a secured and regulated financial environment is being provided by the stock market where shares can be transacted at lower operational risk. The stock market also functions as a platform through savings, and investments of individuals are channelized into productive investment proposals. It allows capital formation and economic growth for the nation. The ultimate objective of this study is to examine the impact of macroeconomic variables on stock market performance. The macroeconomic variables (independent variables) used in this research study are Inflation, Interest Rate, and GDP. Stock market performance (All-Share Price Index) is the dependent variable. 120 Monthly observations from January 2009 to December 2018 had been taken for the study. The Augmented Dickey Fuller’s unit root test, Ordinary Least Squares Regression and Correlation analysis were applied to the variables. The results of correlation analysis indicated that inflation and Stock market performance are positively associated meanwhile interest rate, and GDP and Stock market performance are negatively correlated. The Ordinary Least Square results showed that nearly 75% of the variation in all share price index is explained by the three macroeconomic variables, GDP, TB and WPI. The study suggested some of the possible reasons for the positive impact of Inflation on the Colombo Stock market performance, and negative impact of Interest Rate on Stock market performance and recommended that efforts should be made to improve the Stock market performance.DOI: http://doi.org/10.31357/fhss/vjhss.v05i02.0
Effect of magnetic flux and of electron momentum on the transmission amplitude in the Aharonov-Bohm ring
A characterization of the two-terminal open-ring Aharonov-Bohm interferometer
is made by analyzing the phase space plots in the complex transmission
amplitude plane. Two types of plots are considered: type I plot which uses the
magnetic flux as the variable parameter and type II plot which uses the
electron momentum as the variable parameter. In type I plot, the trajectory
closes upon itself only when the ratio of the arm lengths (of the
interferometer) is a rational fraction, the shape and the type of the generated
flower-like pattern is sensitive to the electron momentum. For momenta
corresponding to discrete eigenstates of the perfect ring (i.e. the ring
without the leads), the trajectory passes through the origin a certain fixed
number of times before closing upon itself, whereas for arbitrary momenta it
never passes through the origin. Although the transmission coefficient is
periodic in the flux with the elementary flux quantum as the basic period, the
phenomenon of electron transmission is shown not to be so when analyzed via the
present technique. The periodicity is seen to spread over several flux units
whenever is a rational fraction whereas there is absolutely no periodicity
present when is an irrational number. In type II plot, closed trajectories
passing through the origin a number of times are seen for being a rational
fraction. The case R=1 (i.e. a symmetric ring) with zero flux is rather
pathological--it presents a closed loop surrounding the origin. For irrational
values, the trajectories never close.Comment: accepted in Int. J. Mod. Phys. B, RevTeX
Indigenous hydropriming practice for fastening seed germination might induce reciprocal effects in chickpea (Cicer arietinum L.) under “on-farm” seed priming scenario
From the vedic times, the cultivation of crops in India, were meant for sustenance of mankind. The age old practices transferred across generations have being followed by the young and the old without a second thought. The main land agriculture that has adopted several of these practices has witnessed many a kind of ups and downs from replicating these practices. The lack of a strategic scientific validation aided with the misinformation by passing the indigenous knowledge across generations have caused many a kind of deleterious effects too. One of such traditional practice is the soaking of seeds prior to germination that is being scientifically stated as the seed priming which enhances the process of germination. Though the “on- farm” seed priming technology have been pointed out as a sustainable option for the intensification of agriculture in marginal and tribal belts of the country, its recommendation needs prior standardization in and across various crop genotypes. Hence, in this study the effect of different durations of hydropriming on the germination and growth of Chickpea (Cicer arietinum L.) were assessed. BGD 72 variety of Desi and BGD 128 variety of Kabuli were used for the study. It was observed that there occurs wide variation in germination and seedling growth across the intervals of priming and each positive effect is sharply - duration and genotype specific.
Common Coronary Anomalies on MDCT
Coronary artery anomalies are rare, and the incidence is around 1 to 2% in the general population. Majority of the patients are asymptomatic and detected while investigating another clinical issue. A few anomalies may be life-threatening due to the malignant course with potential for ischemia and even sudden death. Multidetector computed tomography (MDCT) has high accuracy in detecting these anomalies because of volume rendering (VR) and multiplanar reconstruction (MPR). ‘High take-off’, origin of the coronary artery from the opposite or noncoronary cusp with anomalous course and coronary artery fistula are three most frequent anomalies. MDCT can be a useful screening tool in the study of coronary anomalies
Common Coronary Anomalies on MDCT
Coronary artery anomalies are rare, and the incidence is around 1 to 2% in the general population. Majority of the patients are asymptomatic and detected while investigating another clinical issue. A few anomalies may be life-threatening due to the malignant course with potential for ischemia and even sudden death. Multidetector computed tomography (MDCT) has high accuracy in detecting these anomalies because of volume rendering (VR) and multiplanar reconstruction (MPR). ‘High take-off’, origin of the coronary artery from the opposite or noncoronary cusp with anomalous course and coronary artery fistula are three most frequent anomalies. MDCT can be a useful screening tool in the study of coronary anomalies
Role of NADPH Oxidase-4 in human endothelial progenitor cells
Introduction: Endothelial progenitor cells (EPCs) display a unique ability to promote angiogenesis and restore endothelial function in injured blood vessels. NADPH oxidase 4 (NOX4)-derived hydrogen peroxide (H2O2) serves as a signaling molecule and promotes endothelial cell proliferation and migration as well as protecting against cell death. However, the role of NOX4 in EPC function is not completely understood. Methods: EPCs were isolated from human saphenous vein and mammary artery discarded during bypass surgery. NOX4 gene and protein expression in EPCs were measured by real time-PCR and Western blot analysis respectively. NOX4 gene expression was inhibited using an adenoviral vector expressing human NOX4 shRNA (Ad-NOX4i). H2O2 production was measured by Amplex red assay. EPC migration was evaluated using a transwell migration assay. EPC proliferation and viability were measured using trypan blue counts. Results: Inhibition of NOX4 using Ad-NOX4i reduced Nox4 gene and protein expression as well as H2O2 formation in EPCs. Inhibition of NOX4-derived H2O2 decreased both proliferation and migration of EPCs. Interestingly, pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) decreased NOX4 expression and reduced survival of EPCs. However, the survival of EPCs was further diminished by TNF-α in NOX4-knockdown cells, suggesting that NOX4 has a protective role in EPCs. Conclusion: These findings suggest that NOX4-type NADPH oxidase is important for proliferation and migration functions of EPCs and protects against pro-inflammatory cytokine induced EPC death. These properties of NOX4 may facilitate the efficient function of EPCs which is vital for successful neovascularization
Antifungal potential of Azotobacter species and its metabolites against Fusarium verticillioides and biodegradation of fumonisin
Abstract Aims In the study, seven Plant Growth Promoting Rhizobacteria (PGPR) Azotobacter species were screened against three strains of Fusarium verticillioides to test its antifungal activity. Azotobacter strains were tested for the degradation of fumonisin produced by F. verticillioides. Secondary metabolites were isolated and characterized from the Azotobacter strains for the first time. Methods and Results Potential seven Azotobacter species antifungal activity was tested following the dual culture assay against three strains of Fusarium verticillioides namely FVM-42, FVM-86 and MTCC156 estimating the substantial zone of inhibition. Azotobacter species AZT-31 and AZT-50 strains significantly inhibited the growth of F. verticillioides recording drastic growth enhancement of maize under in-vitro conditions by calculating the infection incidence, vigour index and germination percentage. As confirmation, dereplication studies were conducted for the reconfirmation of Azotobacter strains by isolating from rhizoplane. Azotobacter strains played a key role in the degradation of fumonisin produced by F. verticillioides reporting 98% degradation at 2Â h of incubation with the pathogen. Furthermore, in the study first time, we have tried to isolate and characterize the secondary metabolites from the Azotobacter strains exhibiting six compounds from the species AZT-31 (2) and AZT-50 (4). Preliminary in-vitro experiments were carried out using the compounds extracted to check the reduction of infection incidence (90%) and increase in germination percentage upto 50 to 70% when compared to the test pathogen. Conclusion Azotobacter strains referred as PGPR on influencing the growth of plant by producing certain substances that act as stimulators on inhibiting the growth of the pathogen. Significance and Impact of the study The future perspective would be the production of an active combination of carboxamide compound and Azotobacter species for preventively controlling the phytopathogenic fungi of plants and crops and also towards the treatment of seeds
Comparing novelty of designs from biological-inspiration with those from brainstorming
This research aims to understand the significance of biological-analogies in fostering novelty by comparing biological-analogies with other design methods for idea generation. Among other design methods, brainstorming was chosen here as benchmark. Four studies were conducted to compare: (i) the levels of abstraction at which concepts were ideated using biological inspiration (represented using biocards) with that using traditional brainstorming; and (ii) the novelty of concepts produced by using these two design methods. Concepts produced in these studies were evaluated for levels of abstraction at which they were ideated, average novelty, and proportion of high-novelty concepts. Results suggest that concepts generated using biocards were ideated at higher abstraction levels than those using brainstorming, but neither were at the highest abstraction levels. The average novelty of concepts produced using biocards was found to be greater than that using brainstorming; however, no statistically significant difference was found in the proportion of high-novelty concepts. We suspect the lack of biological knowledge and cultural difference among the subjects involved in our studies as the two reasons behind the results. The results demonstrate that the design methods substantially influence the novelty of concepts generated, while indicating the need for better training in effective use of biological-analogies
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