Exploring the Molecular Properties of Collagen Type IV with Atomic Force Microscopy

Collagen type IV is a network-forming collagen that provides support and anchorage to cells. Its basic structural unit is a 410 nm long and 1.5 nm in diameter triple helix, with natural discontinuities in the triple-helical defining Gly-X-Y sequence. The C-terminal globular domain (NC1) in a collagen IV molecule plays an important role in forming networks, and has recently been reported to be structurally triggered by chloride ions to form hexamers outside the cell. How this hexamer assembles in vitro remains unknown. Here, I aim to use atomic force microscopy (AFM) to investigate the molecular basis of collagen type IV network assembly by studying the effects of different solvent conditions on the stability of the NC1 domain. Studying the dissociation of this hexametric domain can shed light onto how it assembles in solution and under what ionic conditions. The flexibility of the collagen type IV molecule is also investigated by performing statistical analysis of AFM-imaged chains and estimating persistence length, a mechanical property that quantifies the flexibility of a polymer. Here, I investigate the effects of triple helix interruptions on the flexibility of the molecule, by comparing collagen type IV to other fibrillar collagens that are continuously triple-helical. In addition, I determine a position-dependent flexibility profile of the molecule showcasing the effects of over-lapping interruptions, from a α1(IV)]2–α2(IV) mouse collagen type IV, on the persistence length

Reversed-Phase HPLC Determination of Citral in Locally Grown Lemon Grass Harvested at Different Season.

A simple HPLC procedure for the quantitative determination of citral, the major fragrant component in the lemon grass, has been developed. The procedure involves a C-8 stationary phase using a 90:10 methanol: water pH 5 mobile phase containing 0.25% 1-octanesulfonic acid and an UV detector (set at 233 nm). The lemon grass leaves were harvested fresh at different times of the year and were soaked in methanol for 48 hours without any mechanical assistance to extract the citral and other methanol soluble components. The method showed good reproducibility with relative standard deviation of 2.8% and 10.8% for two different sets of samples. The method showed linearity in the range of 0.89 - 35.52 μg/mL. The average recovery was 104.8%. The amount of citral found as a percentage of the dried leaves are, 0.093, 0.27, 0.10, 0.13, 0.16, and 0.066 for fall, winter, three summer, and 1 commercial store samples, respectively

The Relationship between Audit Committees, Corporate Environmental Disclosure, and Environmental Reputation: UK Evidence

The thesis examines the determinants of the volume of environmental disclosures and their quality, with particular reference to the role of audit committees and the role of such disclosures in the creation and sustenance of firms’ environmental reputation. It also examines the impact of environmental reputation on enhancing firm financial performance. Using a resource-based view (RBV) and quality signalling approach, this study examines three questions: first, to what extent are the volume and quality of environmental disclosures determined by the resource base of the firm and the quality of its audit committee?; second, does the combination of quality disclosures and audit committee add to the reputation of the firm?; and finally, what is the relationship between corporate environmental reputation and firm financial performance? Using a sample of UK FTSE 350 companies from 2007-2011, I found evidence that larger firms with higher quality audit committees make higher quality disclosures. These firms enhance their reputations by virtue of their size, the quality of their audit committees, the quality of their disclosures, and their board size. Larger firms with block shareholders tend to have greater volume of disclosures, whilst audit committees and larger boards tend to have no role in promoting such disclosures. Higher disclosure volume alone does not lead to increased reputation. These results therefore show support for the RBV quality signalling approach. Larger firms possess a greater resource base and, therefore, have the ability to invest in non-replicable corporate social responsibility (CSR) strategies. Audit committees, which possess Smith Report compliant features, promote reputation directly and through their determination of better quality disclosures that are difficult to replicate by competitors, thereby signalling the firm specific competitive advantage investments to the market. When revisiting the relationship between environmental reputation and financial performance, results indicate a positive impact of corporate environmental reputation on financial performance measured by both accounting and market-based measures, and were consistent with the RBV of the firm. Findings in this study have implications for managers in terms of disclosure practices where the quality of disclosure is an important aspect and of a higher value due to the difficulty of replication by companies not genuinely committed to environmental good practice. Moreover, the study aims to provide managers with a better view of how governance and specifically audit committee can impact the setting of environmental goals and enhance accountability. Finally, corporations looking to regain trust with investors and other stakeholders need to take steps towards an environmental agenda

The Covid-19 pandemic and its impact on profitability: case study of companies listed in Amman Stock Exchange during the years (2019 – 2020)

تعتبر بورصة عمان (ASE) مؤسسة مالية رئيسية في الأردن، ومن المحتمل أن يكون للوباء تأثير على ربحية الشركات المدرجة في بورصة عمان. تهدف هذه الدراسة إلى التحقيق في تأثير جائحة Covid-19 على ربحية الشركات المدرجة في بورصة عمان خلال السنوات 2019-2020. ستحلل الدراسة تأثير الوباء على المؤشرات المالية المختلفة مثل صافي الربح والإيرادات ودخل التشغيل. كما اعتمدت هذه الدراسة على تحليل توصيات الأبحاث السابقة التي تم إجراؤها حول نفس الموضوع والتي تم نشرها في المجلات العلمية خلال الفترة 2019-2022. تقدم نتائج هذه الدراسة نظرة ثاقبة حول تأثير Covid-19 على ربحية الشركات المدرجة في بورصة عمان. تُظهر النتائج أن العديد من الشركات تأثرت بالفعل بالوباء، وتمكنت شركات أخرى من تقليل الآثار الجانبية والنجاة من هذه الأزمة.The Amman Stock Exchange (ASE) is a major financial institution in Jordan, and the pandemic is likely to have had an impact on the profitability of companies listed on the ASE. This study aims to investigate the impact of the Covid-19 pandemic on the profitability of companies listed on the ASE during the years 2019-2020. The study will analyze the impact of the pandemic on various financial indicators such as net profit, revenue, and operating income. This study also depended on analyzing the recommendations of previous research that’s been done on the same topic which were published in scientific journals during 2019-2022. The findings of this study provide insights into the impact of the Covid-19 on the profitability of companies listed on the ASE. The results showcase that many companies were indeed affected by the pandemic, and other companies managed to minimize the side effects and survive this crisis

A Hierarchical Filtering-Based Monitoring Architecture for Large-scale Distributed Systems

On-line monitoring is essential for observing and improving the reliability and performance of large-scale distributed (LSD) systems. In an LSD environment, large numbers of events are generated by system components during their execution and interaction with external objects (e.g. users or processes). These events must be monitored to accurately determine the run-time behavior of an LSD system and to obtain status information that is required for debugging and steering applications. However, the manner in which events are generated in an LSD system is complex and represents a number of challenges for an on-line monitoring system. Correlated events axe generated concurrently and can occur at multiple locations distributed throughout the environment. This makes monitoring an intricate task and complicates the management decision process. Furthermore, the large number of entities and the geographical distribution inherent with LSD systems increases the difficulty of addressing traditional issues, such as performance bottlenecks, scalability, and application perturbation. This dissertation proposes a scalable, high-performance, dynamic, flexible and non-intrusive monitoring architecture for LSD systems. The resulting architecture detects and classifies interesting primitive and composite events and performs either a corrective or steering action. When appropriate, information is disseminated to management applications, such as reactive control and debugging tools. The monitoring architecture employs a novel hierarchical event filtering approach that distributes the monitoring load and limits event propagation. This significantly improves scalability and performance while minimizing the monitoring intrusiveness. The architecture provides dynamic monitoring capabilities through: subscription policies that enable applications developers to add, delete and modify monitoring demands on-the-fly, an adaptable configuration that accommodates environmental changes, and a programmable environment that facilitates development of self-directed monitoring tasks. Increased flexibility is achieved through a declarative and comprehensive monitoring language, a simple code instrumentation process, and automated monitoring administration. These elements substantially relieve the burden imposed by using on-line distributed monitoring systems. In addition, the monitoring system provides techniques to manage the trade-offs between various monitoring objectives. The proposed solution offers improvements over related works by presenting a comprehensive architecture that considers the requirements and implied objectives for monitoring large-scale distributed systems. This architecture is referred to as the HiFi monitoring system. To demonstrate effectiveness at debugging and steering LSD systems, the HiFi monitoring system has been implemented at the Old Dominion University for monitoring the Interactive Remote Instruction (IRI) system. The results from this case study validate that the HiFi system achieves the objectives outlined in this thesis

The pivotal role of cholesterol absorption inhibitors in the management of dyslipidemia

Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease. Ezetimibe is the first member of a new class of selective cholesterol absorption inhibitors. It impairs the intestinal reabsorption of both dietary and hepatically excreted biliary cholesterol. Ezetimibe is an effective and safe agent for lowering LDL-C and non HDL-C. Short term clinical trials have established the role of ezetimibe monotherapy and its use in combination with statins. Furthermore, ezetimibe and statin combination therapy increased the percentage of patients who achieved their LDL-C treatment goal. Studies using surrogate markers of atherosclerosis have suggested a possible role of ezetimibe in combating atherosclerosis. Ezetimibe provides an effective therapeutic strategy for the management of homozygous familial hypercholesterolemia (HoFH) and sitosterolemia. The lack of outcomes and long term safety data is attributed to the relatively recent introduction of this medication

CEO compensation and sustainability reporting assurance: Evidence from the UK

© 2017 The Author(s) Companies are expected to monitor sustainable behaviour to help improve performance, enhance reputation and increase chances of survival. This paper examines the relationship between sustainability committees and independent external assurance on the inclusion of sustainability-related targets in CEO compensation contracts. Using a sample of UK FTSE350 companies for 2011–2015 and controlling for governance and firm characteristics, we find both board-level sustainability committees and sustainability reporting assurance have a positive and significant association with the inclusion of sustainability terms in compensation contracts. However, there is no joint impact between the voluntary use of independent external assurance and the role of sustainability committees on CEO compensation contracts. Sustainability-related terms in compensation contracts are more likely to be included, and higher compensation is likely to be paid, when assurance is provided by a Big4 firm and when a company operates in a sustainability-sensitive industry. Our findings highlight the potential of assured sustainability reports in assessing CEO performance in sustainability-related tasks, especially when sustainability metrics are included in CEO compensation contracts. Overall, our results suggest companies that invest in voluntary assurance are more likely to monitor management’s behaviour and be concerned about the achievement of sustainability goals

Audit committee disclosure tone and earnings management

Purpose: This paper examines the effect of audit committee (AC) reporting, measured by the tone of audit committee disclosures, in improving financial reporting quality as proxied by earnings management. Design/methodology/approach: The authors focus on the textual properties of AC reports, particularly the tone of AC disclosure, and their impact on financial reporting quality proxied using real and accruals-based earnings management. For additional analysis, the authors use a financial reporting index and matched sample. The analysis is based on a sample of UK FTSE 350 firms. Findings: The analysis suggests that AC reports are not boilerplate but varied in language. The authors find AC reporting is negatively associated with both real and accruals-based earnings management. In our additional tests, the authors find a positive association between financial reporting quality index and reporting tone. Research limitations/implications: Overall, this paper provides baseline evidence for future research and policy making and reveals that ACs reporting what they have done increases transparency and impacts on reporting quality. Practical implications: Overall, this paper suggests that the tone of AC reports seems to convey information that affects the communication function of AC reporting and thereby helps to improve reporting quality. Originality/value: Though the importance of AC disclosures in improving reporting quality is well recognised in policy guidelines and governance recommendations, no study has employed computer-based textual analysis of AC reports and investigated the effect of AC disclosure tone and the role it can play in achieving higher reporting quality