Stock Price Reaction to the Stock Splits Announcement of Listed Companies in the Colombo Stock Exchange

A stock split is a corporate event that directly impacts the number of a company’s shares and indirectly on stock prices. This study tests the effect of the stock splits on the share price of companies listed in the Colombo Stock Exchange during the periods of pre and post stock split announcement in accordance with the Efficient Market Hypothesis. The main objective of this paper is to identify the overall impact of a stock split announcement on stock prices. This study analyses 88 annual stock splits during the ten (10) year period from 2009 to 2019 by taking the listed companies in the Colombo Stock Exchange into consideration. It uses the event study methodology to test the market efficiency of the Colombo Stock Exchange, and the market model is run with the aid of abnormal returns, which are calculated based on daily closing stock prices and the All-Share Price Index. For analysing the results, the graphical analysis and t statistics have been utilized. According to the event day average abnormal return, the majority of stock splits were more negative than positive with a significant t value at 5% by indicating that investors were taking the stock split announcement as bad news just after the split announcement was released. Each day with a significant Average Abnormal Return shows more positives than negatives. Graphical results have shown both Average Abnormal Return, and Cumulative Average Abnormal Return has remained continuously negative up to 18 and 25 days, respectively, by implicating that stock splits have made a deleterious impact on stock return. This study finally concludes that the information regarding the stock splits has not been absorbed efficiently by the market because the market reactions before and after the date of the split announcement were significant at 5%, although the Average Abnormal Return got a quick reaction to the announcement. Furthermore, results had not provided evidence for Semi-Strong Form efficiency of the Colombo Stock Exchange since the significant stock price adjustments before and after the event day was noticed. By this study, the policymakers and investors are convinced that all information has not been incorporated into stock prices in making their decisions. Keywords: Efficient market hypothesis; Event study methodology; Signalling theory; Sri Lanka; Stock split

Chart Adequacy: Workshop and GEBCO Training

In July, 2015 the first NOAA Chart Adequacy Workshop was held in Silver Spring, Maryland, USA. Following a three-day workshop (14th to 16th July, 2015), four Nippon Foundation GEBCO students stayed at NOAA for an additional 10-day training at Office of Coast Survey’s Marine Chart Division. The key objective of the NOAA Chart Adequacy Workshop was to demonstrate techniques to evaluate the suitability of nautical chart products using chart quality information and publicly-available information. The attendees were cartographers, hydrographers and potential chart producers from hydrographic offices and government agencies around the world. The nations of the participants in the workshop included: Indonesia, Israel, Japan, Kenya, Malaysia, Philippines, South Korea, Sri Lanka, United Kingdom, United States and Venezuela. Through instructor presentations and GIS laboratory exercises (provided by Dr. Shachak Pe’eri and Lt Anthony Klemm), the participants generated the key layers that are involved in the NOAA procedure. A vessel traffic layer was generated by classification of navigational routes using Automatic Identification Systems (AIS) information. A bathymetric difference layer was generated by identifying areas that showed significant bathymetric changes identified by comparing Satellite-Derived Bathymetry (SDB) or other surveys of opportunity, with the existing chart. A hydrographic characteristics layer was generated by classification of chart quality information. Chart data (including the smooth sheet sounding sets) for the procedure were provided in a vector format with the appropriate metadata according to IHO S-57. Raster Navigational Charts were also used as a background and as a reference for the Bathymetric Difference layer

Redox-Induced Src Kinase and Caveolin-1 Signaling in TGF-β1-Initiated SMAD2/3 Activation and PAI-1 Expression

Plasminogen activator inhibitor-1 (PAI-1), a major regulator of the plasmin-based pericellular proteolytic cascade, is significantly increased in human arterial plaques contributing to vessel fibrosis, arteriosclerosis and thrombosis, particularly in the context of elevated tissue TGF-β1. Identification of molecular events underlying to PAI-1 induction in response to TGF-β1 may yield novel targets for the therapy of cardiovascular disease.Reactive oxygen species are generated within 5 minutes after addition of TGF-β1 to quiescent vascular smooth muscle cells (VSMCs) resulting in pp60(c-src) activation and PAI-1 expression. TGF-β1-stimulated Src kinase signaling sustained the duration (but not the initiation) of SMAD3 phosphorylation in VSMC by reducing the levels of PPM1A, a recently identified C-terminal SMAD2/3 phosphatase, thereby maintaining SMAD2/3 in an active state with retention of PAI-1 transcription. The markedly increased PPM1A levels in triple Src kinase (c-Src, Yes, Fyn)-null fibroblasts are consistent with reductions in both SMAD3 phosphorylation and PAI-1 expression in response to TGF-β1 compared to wild-type cells. Activation of the Rho-ROCK pathway was mediated by Src kinases and required for PAI-1 induction in TGF-β1-stimulated VSMCs. Inhibition of Rho-ROCK signaling blocked the TGF-β1-mediated decrease in nuclear PPM1A content and effectively attenuated PAI-1 expression. TGF-β1-induced PAI-1 expression was undetectable in caveolin-1-null cells, correlating with the reduced Rho-GTP loading and SMAD2/3 phosphorylation evident in TGF-β1-treated caveolin-1-deficient cells relative to their wild-type counterparts. Src kinases, moreover, were critical upstream effectors of caveolin-1(Y14) phosphoryation and initiation of downstream signaling.TGF-β1-initiated Src-dependent caveolin-1(Y14) phosphorylation is a critical event in Rho-ROCK-mediated suppression of nuclear PPM1A levels maintaining, thereby, SMAD2/3-dependent transcription of the PAI-1 gene

Predicting Functional and Regulatory Divergence of a Drug Resistance Transporter Gene in the Human Malaria Parasite

Background: The paradigm of resistance evolution to chemotherapeutic agents is that a key coding mutation in a specific gene drives resistance to a particular drug. In the case of resistance to the anti-malarial drug chloroquine (CQ), a specific mutation in the transporter pfcrt is associated with resistance. Here, we apply a series of analytical steps to gene expression data from our lab and leverage 3 independent datasets to identify pfcrt-interacting genes. Resulting networks provide insights into pfcrt’s biological functions and regulation, as well as the divergent phenotypic effects of its allelic variants in different genetic backgrounds. Results: To identify pfcrt-interacting genes, we analyze pfcrt co-expression networks in 2 phenotypic states - CQ-resistant (CQR) and CQ-sensitive (CQS) recombinant progeny clones - using a computational approach that prioritizes gene interactions into functional and regulatory relationships. For both phenotypic states, pfcrt co-expressed gene sets are associated with hemoglobin metabolism, consistent with CQ’s expected mode of action. To predict the drivers of co-expression divergence, we integrate topological relationships in the co-expression networks with available high confidence protein-protein interaction data. This analysis identifies 3 transcriptional regulators from the ApiAP2 family and histone acetylation as potential mediators of these divergences. We validate the predicted divergences in DNA mismatch repair and histone acetylation by measuring the effects of small molecule inhibitors in recombinant progeny clones combined with quantitative trait locus (QTL) mapping. Conclusions: This work demonstrates the utility of differential co-expression viewed in a network framework to uncover functional and regulatory divergence in phenotypically distinct parasites. pfcrt-associated co-expression in the CQ resistant progeny highlights CQR-specific gene relationships and possible targeted intervention strategies. The approaches outlined here can be readily generalized to other parasite populations and drug resistances

Increased growing temperature reduces content of polyunsaturated fatty acids in four oilseed crops

Environmental temperature directly influences the lipid profile produced by oilseeds. If growing temperatures increase, as is predicted by current models, the precise profile of lipids produced are likely to change. This paper develops models to predict lipid profiles as a function of growing temperature. Data relating to lipid profiles of soybean (Glycine max), spring canola (Brassica napus), spring camelina (Camelina sativa), and sunflower (Helianthus annuus) were gathered from the literature and evaluated to examine the influence of temperature on relative production of oleic, linoleic, and linolenic acid. For each crop, a set of linear regressions was used to correlate temperature during the grain fill, defined as 30 days before harvest, with the molar percentages of oleic, linoleic, and linolenic acid present. An increase in temperature from 10 to 40°C resulted in an increase in the production of oleic acid and a decrease in the production of linoleic and linolenic acid in soybeans, canola, and sunflowers. Over the range of data available, the lipid profile of camelina was temperature insensitive. To test the validity of the correlations, the four crops were grown in a field study in Manhattan, Kansas simultaneously, in the same environment, in 2011. The correlations accurately predicted the field data for soybean, canola, and camelina but not for sunflower. The correlation for sunflower under-predicted the molar amount of oleic acid and over-predicted the molar amount of linoleic acid. This study indicates increasing growing temperatures from 10 to 40°C will result in more monounsaturated oils and less polyunsaturated oils in soybean, canola, and sunflower

Zig-Zag magnetic order and potential Kitaev interactions in the spin-1 honeycomb lattice KNiAsO4_4

Despite the exciting implications of the Kitaev spin-Hamiltonian, finding and confirming the quantum spin liquid state has proven incredibly difficult. Recently the applicability of the model has been expanded through the development of a microscopic description of a spin-1 Kitaev interaction. Here we explore a candidate spin-1 honeycomb system, KNiAsO$_4$ , which meets many of the proposed criteria to generate such an interaction. Bulk measurements reveal an antiferromagnetic transition at $\sim$ 19 K which is generally robust to applied magnetic fields. Neutron diffraction measurements show magnetic order with a $\textbf{k}=(\frac{3}{2},0,0)$ ordering vector which results in the well-known ``zig-zag" magnetic structure thought to be adjacent to the spin-liquid ground state. Field dependent diffraction shows that while the structure is robust, the field can tune the direction of the ordered moment. Inelastic neutron scattering experiments show a well defined gapped spin-wave spectrum with no evidence of the continuum expected for fractionalized excitations. Modeling of the spin waves shows that the extended Kitaev spin-Hamiltonians is generally necessary to model the spectra and reproduce the observed magnetic order. First principles calculations suggest that the substitution of Pd on the Ni sublattice may strengthen the Kitaev interactions while simultaneously weakening the exchange interactions thus pushing KNiAsO$_4$ closer to the spin-liquid ground state.Comment: 13 pages, 7 figure

Environmental Preferences of Yellowfin Tuna in the North East Indian Ocean: An Application of Satellite Data to Longline Catches

Abstract: Development of state-of-the-art methodologies to minimise search time and to increase the fishing efficiency of high seas fishery are vital for fishing success. It, minimise the operational cost as well as fishing duration that save the fish quality. Understanding of the ocean environment and their preferences of Yellowfin Tuna (YFT) are important aspect to addresses the fishing uncertainty thereby ensuring the expected catch during a short period of time. Environmental parameters such as temperature, chlorophyll and dynamic height of the sea surface were obtained from remote sensing satellites and a YFT catch dataset was obtained from Sri Lankan longliners. The results of the data analyses have shown that the relationships between oceanographic parameters and YFT catch rates were found significant. These relations are capable of predicting fishable aggregations of YFT using near-real time satellite observations. High frequencies of YFT catches were found in the areas where Sea Surface Temperature (SST) varied primarily between 28-30C. The corresponding Sea Surface Heights (SSH) ranged from 205-215 cm and Sea Surface Clorophyll_a (SSC) concentration ranged from 0.1-0.4 mg/m 3 . The relationships between catch rates and the three environmental variables have been tested with the Empirical Cumulative Distribution Function (ECDF). The degrees of differences between the ECDF and catch-weighted cumulative distributions of the three variables are statistically significant (p<0.01). The strongest association showed between catch rates and SSC while SSH showed the lowest. The results obtained from a Generalized Additive Model (GAM) have shown that the space-time factor is well above the ocean environmental factors and the oceanographic factors are also in significant levels (p<0.05). Therefore, the migratory pathway is an essential factor in predicting YFT inhabitants in the northeast Indian Ocean