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

Secretory proteomic responses of endometrial epithelial cells to trophoblast-derived extracellular vesicles

Synchronized crosstalk between the embryo and endometrium during the periconception period is integral to pregnancy establishment. Increasing evidence suggests that the exchange of extracellular vesicles (EVs) of both embryonic and endometrial origin is a critical component of embryo–maternal communication during peri-implantation. Here, we investigated whether embryonic signals in the form of EVs can modulate the endometrial epithelial cell secretome. Receptive endometrial analog RL95-2 cells were supplemented with trophoblast analog JAr cell-derived EVs, and the secretory protein changes occurring in the RL95-2 cells were analyzed using mass spectrometry. EVs of non-trophoblastic origin (HEK 293 cells) were used as the control EV source to supplement endometrial cells. Trophoblast cell-derived EVs enriched endometrial epithelial cell secretions with proteins that support embryo development, attachment, or implantation, whereas control EVs were unable to induce the same effect. The present study suggests that embryonic signals in the form of EVs may prime receptive endometrial epithelial cells to enrich their secretory proteome with critical proteomic molecules with functional importance for periconception milieu formation

Evaluation of the diffusive gradients in thin-films (DGT) technique for measuring nitrate and ammonium in soil

Rationale. The availability of soil nitrogen for plant uptake can be affected by numerous soil factors such as soil texture, moisture and organic matter content, temperature and microbial activity. Conventional extraction techniques may affect the measurement of plant-available N concentrations following sampling and sample preparation processes, including drying, sieving, homogenising, freezing and thawing. The diffusive gradients in thin-films (DGT) technique can overcome some limitations of the conventional extraction techniques and has been used to successfully estimate the plant-available fractions of nutrients, such as P, K, Zn, Cu and Mn in soils. Therefore, it is important to evaluate the use of DGT for measuring NO₃- and NH₄⁺ in a wide variety of soils and examine the factors that contribute to the plant-availability of these ions in soils. Methodology. The experiment evaluated the ability of the DGT technique to measure NO₃-N and NH₄-N in soils using binding layers containing A520E anion exchange resin or Microlite® PrCH cation exchange resin, respectively. The DGT results were compared to those from conventional KCl extraction. Results. The A520E- and PrCH-DGTs showed good detection limits for NO₃-N (6.90 µg L−¹) and NH₄-N (6.23 µg L−¹) and were able to measure potentially available NO₃-N and NH₄-N in unfertilised soils. The mass of NO₃-N and NH₄-N that accumulated on the DGT device increased linearly across soil concentrations ranging from 5 to 300 mg kg−¹ NO₃-N (depending on soil type) and 5–300 mg kg−¹ NH₄-N; which is equivalent to fertiliser rates of 75–450 kg ha¯¹ N. DGTs were used to measure potentially available NO₃-N and NH₄-N in ten soils with various physical and chemical properties. The DGT results were compared with conventional KCl extraction used to determine soil mineral N. DGT and KCl extraction measured values were significantly correlated with each other for NO₃-N (R² = 0.53; P-value < 0.001), but the relationship between the two measurements was weaker for NH₄-N (R² = 0.20, P-value = 0.045). Discussion. The results suggest that the two methods sample different N pools in the soils, with DGT targeting the NO₃-N and NH₄-N that are available in soil pore water and attached to labile solid phases

Wnt activation downregulates olfactomedin-1 in Fallopian tubal epithelial cells:a microenvironment predisposed to tubal ectopic pregnancy

Ectopic pregnancy (EP) occurs when the embryo fails to transit to the uterus and attach to the luminal epithelium of the Fallopian tube (FT). Tubal EP is a common gynecological emergency and more than 95% of EP occurs in the ampullary region of the FT. In humans, Wnt activation and downregulation of olfactomedin-1 (Olfm-1) occur in the receptive endometrium and coincided with embryo implantation in vivo. Whether similar molecular changes happen in the FT leading to EP remains unclear. We hypothesized that activation of Wnt signaling downregulates Olfm-1 expression predisposes to EP. We investigated the spatiotemporal expression of Olfm-1 in FT from non-pregnant women and women with EP, and used a novel trophoblastic spheroid (embryo surrogate)-FT epithelial cell co-culture model (JAr and OE-E6/E7 cells) to study the role of Olfm-1 on spheroid attachment. Olfm-1 mRNA expression in the ampullary region of non-pregnant FT was higher (P0.05) in the follicular phase than in the luteal phase. Ampullary tubal Olfm-1 expression was lower in FT from women with EP compared to normal controls at the luteal phase (histological scoring (H-SCORE)1.30.2 vs 2.40.5; P0.05). Treatment of OE-E6/E7 with recombinant Olfm-1 (0.2-5 g/ml) suppressed spheroid attachment to OE-E6/E7 cells, while activation of Wnt-signaling pathway by Wnt3a or LiCl reduced endogenous Olfm-1 expression and increased spheroid attachment. Conversely, suppression of Olfm-1 expression by RNAi increased spheroid attachment to OE-E6/E7 cells. Taken together, Wnt activation suppresses Olfm-1 expression, and this may predispose a favorable microenvironment of the retained embryo in the FT, leading to EP in humans. © 2012 USCAP, Inc All rights reserved.link_to_OA_fulltex

Uterine fluid extracellular vesicles proteome Is altered during the estrous cycle

Uterine environment is tightly and finely regulated via various signaling pathways mediated through endocrine, exocrine, autocrine, juxtacrine, and paracrine mechanisms. In utero signaling processes are paramount for normal and abnormal physiology which involves cell to cell, cells to gametes, cells to embryo, and even inter-kingdom communications due to presence of uterine microbiota. Extracellular vesicles (EVs) in the uterine fluid (UF) and their cargo components are known to be mediators of in utero signaling and communications. Interestingly, the changes in UF-EV proteome during the bovine estrous cycle and the effects of these differentially enriched proteins on embryo development are yet to be fully discovered. In this study, shotgun quantitative proteomics–based mass spectrometry was employed to compare UF-EV proteomes at day 0, 7, and 16 of the estrous cycle to understand the estrous cycle–dependent dynamics. Furthermore, different phase UF-EVs were supplemented in embryo cultures to evaluate their impact on embryo development. One hundred fifty-nine UF-EV proteins were differentially enriched at different time points indicating the UF-EV proteome is cycle-dependent. Overall, many identified pathways are important for normal uterine functions, early embryo development, and its nutritional needs, such as antioxidant activity, cell morphology and cycle, cellular homeostasis, cell adhesion, and carbohydrate metabolic process. Furthermore, the luteal phase UF-EVs supplementation increased in vitro blastocyst rates from 25.0 ± 5.9% to 41.0 ± 4.0% (p ≤ 0.05). Our findings highlight the importance of bovine UF-EV in uterine communications throughout the estrous cycle. Interestingly, comparison of hormone-synchronized EV proteomes to natural cycle UF-EVs indicated shift of signaling. Finally, UF-EVs can be used to improve embryo production in vitro

Harnessing nature’s defence: the antimicrobial efficacy of pasteurised cattle milk-derived extracellular vesicles on Staphylococcus aureus ATCC 25923

Increasing antimicrobial resistance (AMR) challenges conventional antibiotics, prompting the search for alternatives. Extracellular vesicles (EVs) from pasteurised cattle milk offer promise, due to their unique properties. This study investigates their efficacy against five pathogenic bacteria, including Staphylococcus aureus ATCC 25923, aiming to combat AMR and to develop new therapies. EVs were characterised and tested using various methods. Co-culture experiments with S. aureus showed significant growth inhibition, with colony-forming units decreasing from 2.4 × 105 CFU/mL (single dose) to 7.4 × 104 CFU/mL (triple doses) after 12 h. Milk EVs extended lag time (6 to 9 h) and increased generation time (2.8 to 4.8 h) dose-dependently, compared to controls. In conclusion, milk EVs exhibit dose-dependent inhibition against S. aureus, prolonging lag and generation times. Despite limitations, this suggests their potential in addressing AMR

Artificial Neural Network Inference (ANNI): A Study on Gene-Gene Interaction for Biomarkers in Childhood Sarcomas

Objective: To model the potential interaction between previously identified biomarkers in children sarcomas using artificial neural network inference (ANNI). Method: To concisely demonstrate the biological interactions between correlated genes in an interaction network map, only 2 types of sarcomas in the children small round blue cell tumors (SRBCTs) dataset are discussed in this paper. A backpropagation neural network was used to model the potential interaction between genes. The prediction weights and signal directions were used to model the strengths of the interaction signals and the direction of the interaction link between genes. The ANN model was validated using Monte Carlo cross-validation to minimize the risk of over-fitting and to optimize generalization ability of the model. Results: Strong connection links on certain genes (TNNT1 and FNDC5 in rhabdomyosarcoma (RMS); FCGRT and OLFM1 in Ewing’s sarcoma (EWS)) suggested their potency as central hubs in the interconnection of genes with different functionalities. The results showed that the RMS patients in this dataset are likely to be congenital and at low risk of cardiomyopathy development. The EWS patients are likely to be complicated by EWS-FLI fusion and deficiency in various signaling pathways, including Wnt, Fas/Rho and intracellular oxygen. Conclusions: The ANN network inference approach and the examination of identified genes in the published literature within the context of the disease highlights the substantial influence of certain genes in sarcomas

Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece

Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship

Entrepreneurial growth and ownership under market socialism in China: a longitudinal case study of small business growth

How firms grow is still a mystery and a definitive explanation remains elusive. This is especially the case for emerging economies, where the development of research into business growth has been notably slow whilst emerging business ventures are developing at hyper speed. Since most empirical studies have focused on the quantitative differences in growth across firms, this paper adopts a longitudinal case study approach to explore the qualitative differences in terms of how various types of firm achieve their growth outcomes in the organisational development process over a prolonged period of time. Through a theoretical lens which focuses on growth process approaches, this study not only demonstrates that entrepreneurial processes take different forms and dimensions in different contexts, but it also provides insights into the interactions of various organisational factors underpinning the strategies and changes that lead to contrasting growth outcomes. Case study findings assert that the ownership factor is a key contingent factor that shapes management structure and resources which, in turn, affect particular entrepreneurial outcomes. Furthermore, a combination of leadership style and the approach to knowledge management also play critical roles in the learning process which, tends to determine the strategy choice of either high or low value added product strategy. The findings of this research are that small firms with a low value product strategy can improve their survival chances and growth through the vertical broadening of a product portfolio in synchrony with increasing production and technology advancement. The case study companies show a tendency to reinforce their industry position by adopting contrasting choices for growth. The paper addresses the challenges and managerial implications for Western company managers in different growth contexts