Penetrating keratoplasty: the search for a sutureless solution

SPECIFIC AIM: Worldwide, there is a deficiency in the availability and the outcomes of corneal transplants procedures. The use of sutures in the various types of corneal transplant procedures increases the skill requirements for performing the procedure in addition to bringing about various suture-related complications. In order to avoid these complications and to make the procedure easier to perform, it is vital to review the properties and availability of various surgical adhesives in order to assess their potential as candidates for replacing suture use in corneal transplant procedures. The focus in this paper will be on the most prominent of these procedures: the penetrating keratoplasty procedure. RECENT FINDINGS: Surgical adhesives that could potentially act as replacements or adjuncts to suture use in the penetrating keratoplasty procedure include homologous fibrin adhesives, polyethylene glycol sealants, cyanoacrylate glue, and poly [glycerol-sebacate-acrylate] (PGSA) glue. Polyethylene glycol sealants, when used as adjuncts to suture use in keratoplasty procedures lead to significant levels of wound dehiscence. Fibrin glues have been found to reduce the amount of sutures required in a "top hat" wound configuration penetrating keratoplasty when used as an adjunct to sutures in binding the donor button in place. Cyanoacrylate glues, although having higher levels of adhesive strength than fibrin glue, lead to various unwanted side effects. Lastly, PGSA glue, given its recent development, remains an uncertainty due to the lack of research on it. SUMMARY: Overall, use of homologous fibrin glues is currently the most likely way to reduce the use of sutures in the penetrating keratoplasty procedure. Its use could lead to shorter operative times, fewer complications, reductions in cost, and higher availability for corneal transplant procedures. However, with further investigation, PGSA glue may prove to be a better candidate for the replacement of sutures than fibrin glues

Management of the Omani Abalone Haliotis mariae: An Integrated Policy

The Sultanate of Oman is a small coastal nation with a maritime history, regional trade and fisheries exploitation. Among those fishery industries is Oman\u27s coastal abalone fishery, which command the highest prices per unit of weight among the other marine living resources. This study analyzes the fishery\u27s biological aspects, structure, socioeconomic, policies, and management practices in an attempt to provide an understanding of the prime parameters, that in turn could be utilized for sound management purposes. it also provides a description of an integrated development and management policy for the abalone fishery. Finally, it is hoped that this research will provide valuable information for the Sultanate and guidelines for other researchers

On Strongly F – Regular Modules and Strongly Pure Intersection Property

A submoduleA of amodule M is said to be strongly pure , if for each finite subset {ai} in A , (equivalently, for each a ?A) there exists ahomomorphism f : M ?A such that f(ai) = ai, ?i(f(a)=a).A module M is said to be strongly F–regular if each submodule of M is strongly pure .The main purpose of this paper is to develop the properties of strongly F–regular modules and study modules with the property that the intersection of any two strongly pure submodules is strongly pure

MARKET STRUCTURE AND MORTGAGE PRICING: THE ROLE OF INFORMATION IN FIRM AND CONSUMER BEHAVIOR

This dissertation analyzes information, market structure, and firm pricing strate-gies. I begin the dissertation with an analysis of the market structure of the mortgage in-dustry. I find that the configuration of the mortgage market at its present state is vastly different than its historical structure. The reduction in the cost of transmitting informa-tion has increased the collaborative environment and facilitated the dis-integration of the supply chain. Generally, the mortgage industry has been successful at reducing principal-agent problems and minimizing asymmetric information concerns that arise in segmented markets. In the first essay I provide a theoretical explanation of the effect of the internet on market outcomes. Search models assume that the reduction in search frictions would lead to competitive markets. However, I argue that gatekeepers operating in online markets may create an anticompetitive effect, in addition to reducing the consumers’ search cost. Therefore, the conduct of the gatekeeper can cause prices in online markets to be higher than in retail markets and provide online firms with larger profits. In the second essay “I empirically examine the role of the internet and Internet Comparison Search sites in reducing consumer search costs and their effects on the prices consumers pay for mortgages. Additionally, I expand the study to test for the effects of the internet on firm profits. Using a unique data set, I examine a mortgage firm’s pricing strategies and profits in online and retail markets, and find evidence of market power in online markets that do not exist in retail markets. The presumed benefits to the consumer from the reduction of search cost are offset by the anticompetitive environment in online markets. In the final essay, I examine a mortgage firm’s portfolio choice. I investigate the loan characteristics that affect the firm’s decision to retain mortgages as part of its own portfolio. I find that the decision to retain loans as a lender is driven by unobservable qualities. The firm does sort loans by quality, but it also prices non-brokered loans lower based on unobservable qualities. The sorting behavior suggests that asymmetric information exists between the lender and the secondary market

A New Cipher Based on Feistel Structure and Chaotic Maps

Chaotic systems have been proved to be useful and effective for cryptography. Through this work, a new Feistel cipher depend upon chaos systems and Feistel network structure with dynamic secret key size according to the message size have been proposed. Compared with the classical traditional ciphers like Feistel-based structure ciphers, Data Encryption Standards (DES), is the common example of Feistel-based ciphers, the process of confusion and diffusion, will contains the dynamical permutation choice boxes, dynamical substitution choice boxes, which will be generated once and hence, considered static,             While using chaotic maps, in the suggested system, called Chaotic-based Proposed Feistel Cipher System (CPFCS), we made the confusion and diffusion in dynamical behavior based on Standard and Lorenz maps. The first is used for substitution, and the second one for permutation operations .A proposed cryptographic system uses the same work (the same way) for both enciphering and deciphering. The proposed cipher operates on more than 500 bytes (4000-bit) readable text blocks by six round computing. Within the basic operator of the cipher, i.e., in the function of the round F, a dynamical lookup table 2D standard map system is used to enhance the complexity and diffusion of the unreadable text. Also, a 3D Logistic map used for key sequence generator and chaos based dynamical Initial Permutation (dynamical IP) are used to increase the diffusion and confusion. Three different image sizes and three different text length were implemented in CPFCS.  The results of the proposed system and security tests improve the applicability of PFCS in the data protection and security

Investigation of the constancy of the MWCNTs on the fibres surface for manufactured self-sensing composites

This the author accepted manuscript. The fial version is available from Elsevier via the DOI in this recordDifferent methods have been used to deposit the multi-walled carbon nanotubes (MWCNTs) onto the fibre surface to fabricate self-sensing composites. However, the constancy of the MWCNTs onto the fibre surfaces during infusion processing still unclear. In this study, we have deposited MWCNTs onto the glass fibre surface by two methods to investigate the state of MWCNTs during and after epoxy infusion processing. In the first method, the glass fibres were directly coated with the MWCNTs and in the second method, an adhesive was applied to coat the glass fibre surface before depositing the MWCNTs over it. Rectangular specimens for both types of self-sensing composites were cut from different specified zones and then tested. The results showed that the self-sensing composites with adhesively bonded MWCNTs exhibited more consistent in their properties than the composites where no adhesive was used. In addition, the electrical resistance of both types of self-sensing composites was monitored during the epoxy infusion process. The results showed that the electrical resistance was not obviously affected for composite with non-adhesive bonded MWCNTs and was high for the specimens where the MWCNTs were not adhesively bonded. Moreover, the numerical study was also conducted and the results indicated that the relationship between the volume fraction of the MWCNTs and their tunnelling distance was an inverse. The current study proves evidence that the properties of the self-sensing composites are strongly dependent on the method that used to deposit the MWCNTs on the surface of glass fibres layers.Iraqi Ministry of Oi

The Manufacture and Testing of Self-Sensing CNTs Nanocomposites for Damage Detecting Applications

Composite materials are widely used in various important applications due to their good engineering properties. However, these properties can be reduced when subjected to different type of loads. This thesis experimentally, theoretically and statistically investigates the possibility of using multi-walled carbon nanotubes (MWCNTs) as a filler to fabricate self-sensing nanocomposites for fracture and damage sensing applications. Self-sensing composite based MWCNTs can be used to diagnose early stage damage in order to prevent a fatal fracture that could occur in the structure during its working life. Here, different concentrations of MWCNTs were evenly distributed either in an epoxy resin using high frequency sonication or by depositing them onto the glass fibre surface to make it electrically conductive. Scanning electron microscopy (SEM) and Raman spectroscopy were used to investigate the presence of the MWCNTs and their interaction with the matrix. These self-sensing nanocomposites were subjected to different types of failure such as low velocity impact, static and cyclic compression test under varied temperature, anticlastic deformations including flexural and bending tests. During such testing the mechanical, electrical, impact damage, damage sensitivity, flexural, and piezoresistive properties were examined experimentally and statistically. The results of SEM microscopy showed that the MWCNTs were well distributed inside the matrix, although some agglomeration occurred at high MWCNTs concentrations. Moreover, electrical conductivity measurements indicated a steadily increasing directly proportional relationship with increasing the MWCNTs concentration. In addition, the observed changes in the electrical resistance of specimens increased with increasing impact energy, and temperature. Conversely, the resistance decreased with increasing compression loads, and during flexural and anticlastic testing up to a certain level and then increased due to specimen distortion. In terms of the strain sensitivity, there are two strain sensitivities, in opposite directions obtained, during anticlastic testing and only one obtained under flexural and compression testing conditions. This study has confirmed that the properties of a self-sensing composite are strongly dependent on the method used to deposit the MWCNTs onto the surface of glass fibres layers, the types of test, deformation after testing and the operative test conditions (i.e. temperature). Given these results, it is possible to correlate the degree of damage incurred due to the external loads with the changes in electrical resistance of the MWCNTs-GE nanocomposites both during, and after, loading. Therefore, this type of self-seing nanocomposites shows excellent potential for use in many strain and fracture sensing applications

Employee Perceptions of Emotional Intelligence Among Managers

Efficient managers influence the success and performance of organizations, in contrast to inefficient managers who may negatively affect employee motivation, productivity, stress levels, job satisfaction, and performance. Managers\u27 ability to recognize emotions can positively affect employee motivation, job satisfaction, and performance, which is likely to decrease employee turnover. The purpose of this phenomenological research was to explore the perceptions among employees regarding their managers\u27 EI in relation to employee motivation, job satisfaction, and performance in the Northern Virginia (NOVA) area. The presence of managers\u27 EI skills was explored based on the emotional abilities to facilitate, understand, perceive, and manage emotions. Snowball sampling was used consisting of 20 employees from the NOVA area. The data were collected using in- depth face-to-face semi-structured interviews. Coding and categorizing of interview responses facilitated their thematic analysis. Findings from this sampling suggested that those employees who experienced managers with EI skills reported increased levels of motivation, job satisfaction, and performance. In contrast, those employees from the sampling who experienced managers with a lack of EI skills reported decreased levels of motivation, job satisfaction, and performance. These findings could contribute to positive social change in the workplace focusing on the potential for positive change in human resource, leadership, management, and higher education. The findings could also indicate how these skills help increase employees\u27 motivation, job satisfaction, and performance, as well as effectively manage employee turnover, and improve organizational success

The Impact of Using Mobile Technology on Omani Science Teachers' Reflective Practices and Their Motivation Towards Teaching and Planning Lessons

Mobile technologies, especially smartphones, are globally popular, including amongst teachers. Thus, it could be very helpful for in-service teacher training providers to use such technologies in developing teachers’ practices. This study describes using smartphones as a platform for teachers’ professional development. It reveals levels of reflective practices, and motivation towards teaching and planning lessons, of Omani in-service science teachers, and it explores effects of the professional development on these characteristics. A training programme was designed, based on models of reflection (Kolb’s and Gibb’s Cycles) and on the Expectancy-Value theory of motivation, and hosted on Facebook and Twitter. The programme aim was to improve teachers’ reflective practices and motivation. This study took place in the Al Batinah-North Governorate of the Sultanate of Oman. 83 Omani science teachers were involved over approximately 14 weeks. A pre-post experimental design ensured accurate assessment of the mobile technology programme’s effects. Interviews, questionnaires, and document analyses were employed in order to obtain data. The findings were that Omani science teachers believe that they are at a medium level, on a five-point scale, in respect of reflective practices. However, some evidence shows that their reflective practices might objectively be less than this. They self-report a level higher than medium in motivation towards teaching and planning lessons. The results indicate that Omani female science teachers practise reflection and are motivated towards planning lessons significantly more than their male counterparts. There is a positive, but not statistically significant, impact of mobile technology use on the teachers’ reflective practices and motivation towards teaching and planning. Furthermore, there is a positive relationship between teachers’ reflective practices and their motivation towards planning lessons. Influences on Omani science teachers’ reflective practices and motivation are: professional development methods, workload in relation to focus of attention and to time, and teachers’ personality traits