Impact of Dividend Policy on Shareholders’ Wealth: An Empirical Analysis of Listed Insurance Companies in Pakistan

This study aims to investigate the impact of dividend policy on shareholders’ wealth using secondary data of 17 listed insurance companies in Pakistan employing non-probability convenience sampling for 2012-2015. Shareholders’ wealth is used as dependent variable measured by earning per share whereas dividend policy as independent variable measured by three ratios namely dividend per share, Retention ratio and dividend payout ratio. Analysis techniques include descriptive statistics, regression analysis and correlation analysis. The results show that all the independent variables impact dependent variable positively with dividend per share and retention ratio significant at 5%. Moreover study reveals that the theory of dividend irrelevancy failed in the case of insurance industry of Pakistan.

Assessment of Biosafety and Implantation Feasibility of Novel Phakic Refractive Lens

Purpose: To investigate the biosafety and implantation feasibility of newly developed phakic refractive lens (PRL) in rabbit eyes. Methods: The PRLs, including short PRL (S-PRL), large PRL (L-PRL), and large grooved PRL (LG-PRL), were prepared by molding liquid medical silicon. The in vitro cytotoxicity of the above PRLs was evaluated by incubating them with human lens epithelial cells (HLECs) and then measuring cell viability by CCK-8 assay. In vitro cell adhesion of PRLs was assessed by culturing HLECs on PRL film surface and calculating the cell number and average cell area after stained with Calcein-AM and fluorescent. The implantation feasibility was appraised by observing the relative positions of S-PRL, L-PRL or LG-PRL implanted in the posterior chamber of rabbit eyes by optical coherence tomography, and calculating their retention ratio postoperatively. The intraocular pressure (IOP) of S-PRL, L-PRL, LG-PRL and control groups of rabbit eyes was compared to evaluate the biosafety of implantation.Results: The results of in vitro cytotoxicity showed no significant difference of cell viability was observed in the S-PRL, L-PRL or LG-PRL groups compared to the control group throughout the whole experiment. The HLECs cultured on the PRL film surface presented similar cell number, but smaller average cell area (53.8% vs 100%) when compared to the control group, which implied obvious adhesion inhibition on HLECs caused by PRL film. After implantation of S-PRL, L-PRL or LG-PRL into the posterior chamber of rabbit eyes, no obvious inflammation and IOP elevation were observed at each time point in all sample groups compared to the control group, which indicated that PRL samples had good implantation biosafety. Most of the implanted L-PRL and LG-PRL kept in the correct location, while only less of the S-PRL was at the right site. That was, L-PRL and LG-PRL had proper relative position and high retention ratio in the posterior chamber of rabbit eyes. L-PRL and S-PRL samples tended to attach to iris surface, while LG-PRL sample constructed enough space on the iris surface by its grooves surrounding the central optical zone, which was conducive to circulation of aqueous humor.Conclusions: The newly developed LG-PRL sample presented good biosafety in terms of the negligible in vitro cytotoxicity, ocular inflammation and IOP fluctuations. The LG-PRL provided the best implantation feasibility due to the more proper relative position, available space for aqueous humor circulation, and high retention ratio in the posterior chamber of rabbit eyes among the three kinds of PRL samples. Thus, LG-PRL is a promising alternative with appropriate size and surface structure to more effectively correct refractive errors.

Focal Increased Radiopharmaceutical Uptake Differentiation Using Quantitative Indices

Focal increased radiopharmaceutical uptake in a lesion results in focal Hot Spots in the scans. This can occur in benign infective or inflammatory disorders and cancerous diseases as well. Comparison between malignant and benign lesions is important. The Hot spots can be classified into benign and malignant lesions by Spatial Scintimetry or Temporal Scintimetry. Spatial Scintimetry compares the uptake in the region of interest with the adjacent tissue or the unaffected contralateral site. The quantitative indices are lesion/non lesion ratio, lesion/background activity and lesion to Bone ratio etc. The Temporal Scintimetry relies on the changes in the counts or uptake in the Hotspot lesion with reference to the dual point time of acquisition. The Hotspot in the bone scan can be classified using the quantitative index of retention ratio by Dr. V. Siva and Israel. In PET studies the focal hot spots can be differentiated into benign and malignant lesion using the dual phase PETCT evaluation using the Rong’s Retention ratio and Dr. V. Siva’s modified RRI values.

Effectiveness retention ratio and its standardization

Aim. To promote a better understanding, a wider and more correct application of the effectiveness retention ratio. That is the measure that is best suited for assessing the dependability of complex technical systems, in which partial failures are possible that put a system into intermediate states between complete up and down ones. Methods. The paper uses the methods of the probability theory and comparative analysis of texts of interstate (Euro-Asian), Russian and international dependability-related standards. Results. The principal contribution of Russian researchers to the creation and development of methods for applying effectiveness indicators to estimating the dependability of complex systems is pointed out. Shortcomings were identified in the basic dependability-related standards as regards the effectiveness retention ratio and related concepts. Namely, in terminology standard GOST 27.002–2015, the phrases that require improvement are indicated. They relate to the concepts of partial failure, partial up state and partial down state. A broader and more ac[1]curate definition of partial failure is suggested. It is noted that the relationship between partially up and partially down states are to be discussed and clarified. GOST 27.003–2016 that establishes the content and general rules for specifying dependability requirements contains wording errors in the classification of items according to the number of possible (taken into consideration) states and in the examples of possible variants of the effectiveness retention ratio in various branches of technology that are probabilities of task completion, etc. The paper suggests corrections to the appropriate wordings. It has been established that although the effectiveness retention ratio is not referred to in the international dependability-related terminology standard (IEC 60050-192:2015), it implicitly appears in two IEC standards (IEC 61703:2016 and IEC 62673:2013), in which it is assigned to availability measures. Conclusion. The paper’s findings will be useful to experts involved in the assessment and standardization of complex technical system dependability. Their implementation will help improve interstate, Russian and international dependability-related standards.