Exploring Heterogeneities near Earth’s Inner Core Boundary with Seismic Body Waves

The mechanism of inner core solidification drives the compositional and thermal convection in outer core, sustaining the Earth’s geodynamo. Hence any differences in the manner of crystal growth at the continuously growing inner core boundary(ICB) is essential in understanding secular variations of geomagnetic field. By applying boundary element methods(BEM) to synthesize compressional waves, effects of ICB topography are predicted and compared with waveform observations in pre-critical, critical, post-critical, and diffraction ranges of the wave reflected from the ICB(PKiKP). In the pre-critical range, data require an upper bound of 2km at 1-20km wavelength for any ICB topography. Higher topography sharply reduces PKiKP amplitude and produces time-extended coda not observed in PKiKP waveforms. Topography of this scale smooths over minima and zeros in the pre-critical ICB reflection coefficient predicted from standard Earth models. In the diffracted range(\u3e152°), topography as high as 5km leaves the PKPCdiff/PKIKP amplitude ratio unchanged from that predicted by a smooth ICB. The observed decay of PKPCdiff into the inner core shadow and the PKIKP-PKPCdiff differential travel time are consistent with a flattening of the outer core P-velocity gradient near the ICB and iron enrichment in the lowermost outer core. A search for best fitting attenuation structure for the uppermost IC, shows that eastern hemisphere and the region under Pacific are more attenuating than the rest of the western hemisphere. The BEM study implies that this structure may be resulting from intrinsic attenuation and volumetric scattering. In conclusion, we discuss ways forward in refining the story of IC evolution

Present Status and Conservation of Sri Lankan Aponogeton

Aponogeton is an aquatic genus, represented by four species in Sri Lanka, listed under various conservation categories in The National Red List, A. jacobsenii (CR), A. rigidifolius (EN), A. crispus (VU) and A. natans (VU), of which the former two are endemic. A study on the occurrence and the distribution of Sri Lankan Aponogeton was carried out during the past two years. According to records, A. jacobsenii has been commonly occurring in central highlands. However, during this study, other than the luxurious population in Horton Plains National Park, we could encounter only few, very small poorly grown populations in Pattipola area, which might disappear in near future due to lack of water and the invasion of rushes. Even though, according to literature, A. rigidifolius has commonly occurred in Kaluthara, Rathnapura and Galle districts of the wet zone, we were unable to find any populations in Kaluthara, instead a new undescribed Aponogeton species superficially resembling A. rigidifolius, growing luxuriously. Nevertheless, other few populations encountered in Ratnapura and Galle districts, are under threat due to various anthropogenic activities. Further, despite of being in a protected area, the population beside the entrance of the Kanneliya Forest Reserve has declined considerably within past two years. As in literature, even though, A. natans has been distributed throughout the dry zone and considered as the most common species, we encountered only few populations. Moreover, its habitats; shallow stagnant waters, rice fields and marshes are now disappearing due to the constructions and climate changes, causing a severe threat for its existence. On the other hand, even though there is an apparent reduction, A. crispus is the most abundant species and has shown a satisfactory distribution in the dry and intermediate zones but could be under threat due to the habitat destructions. In addition, these species are extracted in large scale for consumption and medicinal purposes causing sever threat, especially for the two endemics. Contemporary observations have revealed that there is a high possibility of some Aponogeton spp. being extinct from wild in the future. Thus it is necessary to take relevant sustainable measures to conserve these plants and upgrading the conservation status of A. rigidifolius and A. natans is recommended.Keywords: Aquatic plants, Ornamental aquatics, Conservation status, Threaten species, Over exploitatio

Hybrid machine learning architecture for automated detection and grading of retinal images for diabetic retinopathy

Purpose: Diabetic retinopathy is the leading cause of blindness, affecting over 93 million people. An automated clinical retinal screening process would be highly beneficial and provide a valuable second opinion for doctors worldwide. A computer-aided system to detect and grade the retinal images would enhance the workflow of endocrinologists. Approach: For this research, we make use of a publicly available dataset comprised of 3662 images. We present a hybrid machine learning architecture to detect and grade the level of diabetic retinopathy (DR) severity. We also present and compare simple transfer learning-based approaches using established networks such as AlexNet, VGG16, ResNet, Inception-v3, NASNet, DenseNet, and GoogLeNet for DR detection. For the grading stage (mild, moderate, proliferative, or severe), we present an approach of combining various convolutional neural networks with principal component analysis for dimensionality reduction and a support vector machine classifier. We study the performance of these networks under different preprocessing conditions. Results: We compare these results with various existing state-of-the-art approaches, which include single-stage architectures.We demonstrate that this architecture is more robust to limited training data and class imbalance. We achieve an accuracy of 98.4% for DR detection and an accuracy of 96.3% for distinguishing severity of DR, thereby setting a benchmark for future research efforts using a limited set of training images. Conclusions: Results obtained using the proposed approach serve as a benchmark for future research efforts. We demonstrate as a proof-of-concept that an automated detection and grading system could be developed with a limited set of images and labels. This type of independent architecture for detection and grading could be used in areas with a scarcity of trained clinicians based on the necessity

Factors affecting the efficiency of IT governance in Sri Lankan payment card industry

The role of money as the major medium of exchange has been rapidly changing over time and customers value the ease, flexibility, security, and convenience that cashless payment methods provide. Today payment card industry (PCI) is highly technical and information oriented. IT plays a major role in this industry with the main objectives of secure payments with customer satisfaction. On the other hand, IT is a key strategic weapon of the player that can be used to increase the overall organization strategic business objective. However, use of IT is not sufficient to face the challenges, problems, and competition. IT should be properly and carefully governed to align people, processes, and technology to meet the overall organizational strategic objectives. This will enable the PCI players to become the top of the industry gaining the competitive advantage over the other rivals. There is a global expansion and a demand for IT governance in PCI. Sri Lanka is also in the early stage of adapting to IT governance; therefore, this is an important research area at this time. The purpose of this research is to identify the main factors which affect to the efficiency of IT Governance usage in PCI and to analyze how they contribute to making the industry more attractive, efficient and effective. In this research, a conceptual framework is proposed to capture the impact on the perceived user satisfaction and overall organization performance in the aspect of IT Governance adaptation in Technology, Organization, and Environmental Context. Finally, research analysis and findings show that effective IT governance is essential in Sri Lankan payment card business to increase the user satisfaction and overall organization performance. More attention needs to be paid for domain expert’s availability, compliance of rules and regulations, technology adaptation and obtaining support from 3rd party vendors. Research findings show that there is a big potential and an opportunity to effective IT governance in Sri Lankan payment card industry. It also discusses the identified recommendations to improve IT Governance to increase the PCI user satisfaction and overall organization performances

Effectiveness of the Sri Lankan corporate governance system: a stakeholder perspective

Poor corporate governance is often viewed as one of the main factors contributing to the weak company performances and failures in emerging markets (Johnson, 2000). Most of studies which have examined various aspects of corporate governance systems in emerging markets have assessed such practices from the point of view of companies and have paid little attention to examine how such practices are viewed by various stakeholders of the companies in these markets. To fill the gap in accounting literature, this study aims to examine the perceptions of various stakeholder groups in relation to the current status, issues, strategies and practices of corporate governance system in Sri Lanka-an emerging market in Asia. Using data collected from 277 responses on a questionnaire survey covering seven stakeholder groups, these study analyses stakeholder perceptions on eight aspects of the corporate governance system in Sri Lanka. Kruskal-Wallis test is used to examine whether there are significant differences between opinions of stakeholder groups. The findings of this study reveal that while the majority of stakeholders consider governance codes, the financial reporting framework, the regulatory framework, and codes of conduct and ethics as the important components of the corporate governance system, they have not considered some important aspects such as judiciary system, corporate ownership structure, and culture and value systems of the society as important components of the system. Also, although there have been wider agreement on the fact that better corporate governance improves corporate performance and company\u27s ability to access new capital, stakeholders views varied considerably in relation to issues such as the impact of corporate governance on reducing share price volatility, political intervention and cost of capital. The study also identified a number of aspects of corporate governance system in Sri Lanka that are perceived to be poorly designed and enforced and provides suggestions for improvements

Conservation biology of threatened native olives (Notelaea Spp., Oleaceae) in Southern Queensland

Due to the limited resources available, it is necessary to prioritise the conservation action for taxa most at risk of extinction. This study investigated the systematics, population genetics and life-history traits of the two least studied threatened native olive species (Notelaea ipsviciensis and N. lloydii) in Australia, to improve our knowledge of their conservation biology. The results obtained from the genome wide molecular, morphological and comparative life-history trait analysis between rare and common Notelaea spp. in southern Queensland revealed that the taxonomic status of these two species should be re-evaluated and conservation priorities should be revised accordingly

Corporate governance practices and their impacts on corporate performance in an emerging market: the case of Sri Lanka

Many corporate governance practices and reforms in emerging markets are based on corporate governance practices and systems of developed markets, but fail to recognize their suitability and compatibility to these markets. In Sri Lanka, most corporate governance practices are developed based on British practices and they are largely recommended through voluntary codes allowing companies to have considerable discretion in their implementation. The ownership structure of Sri Lankan companies is characterized by a prevalence of family ownership and concentrated ownership, resembling the characteristics of the relationship-based model of corporate governance. Therefore, the application of corporate governance practices originating in Anglo-Saxon countries which typically experience dispersed ownership creates many compatibility issues affecting overall efficiency of corporate governance systems in Sri Lanka. However, no prior study has examined such issues empirically. This study contributes to fill this gap in the academic literature through an in-depth examination of the corporate governance practices of Sri Lanka. This study examines the nature and the level of compliance with corporate governance best practices by Sri Lankan public listed companies, with a view to identifying critical issues of corporate governance practices, and the relationship between level of compliance and firm performance in Sri Lanka. It also examines stakeholders’ perceptions of corporate governance practices in Sri Lanka and the impacts of ownership concentration on firm performance. Three separate data analyses are carried out to achieve these aims. First, the compliance with corporate governance practices is examined through an analysis of a questionnaire survey covering 60 listed companies in Sri Lanka using a corporate governance index. The results show that levels of compliance by Sri Lankan companies to corporate governance best practices vary significantly among companies, and find that such variations directly relate to ownership structures of companies. The results provide prima facie evidence that family ownership and concentrated ownership have a negative influence on corporate governance practices while foreign ownership has a positive influence. The results further reveal that higher levels of compliance have a positive impact on financial performance, but have no impact on market performance. Second, the stakeholder perceptions on eight aspects of the corporate governance system in Sri Lanka are examined using a questionnaire survey of 277 stakeholders from seven stakeholder groups. The analysis of results shows the majority of stakeholders are in agreement that sound corporate governance practices improve corporate financial, market and social performance, and the present status of corporate governance in Sri Lanka is not up to the required standard. Problems of corporate governance identified by stakeholders include: a lack of education in and awareness of corporate governance; inadequate regulations and enforcement; a lack of integrity and independence of directors; insufficient ethical standards; a lack of transparency; ownership concentration; and, political interventions, insider trading and corruption. Overall, the companies and regulators have failed to satisfy stakeholders’ expectations of corporate governance standards in Sri Lanka. Third, on the premise of an agency theory framework, and using both accounting and market-based performance indicators, the relationship between ownership concentration and firm performance is examined. A regression analysis is carried out based on pooled data of 846 firm-years collected from 157 listed companies over the period of 2001 to 2009. The results provide evidence of a strong positive relationship between ownership concentration and accounting performance measures, suggesting a greater concentration of ownership leads to better performance. However, results found no relationship between ownership concentration and market-based performance, suggesting the prevalence of numerous market inefficiencies and anomalies in the Sri Lankan stock market. Overall, the results suggest that compliance with corporate governance practices by respondent firms is closely associated with ownership structure and that better governance seems to correlate with higher financial performance of the firms. The companies with foreign ownership embrace the market-based governance framework thoroughly whereas the companies with family ownership or concentrated ownership raises the question how appropriate is the market-based model of corporate governance for Sri Lankan companies. A policy implication of the results is that the corporate governance reform efforts should pay more attention to enhance the effectiveness of boards. More broadly, priorities should be given to making internal corporate governance mechanisms work better and enhancing the roles of regulatory agencies