Correlation function and electronic spectral line broadening in relativistic plasmas

The electrons dynamics and the time autocorrelation function Cee(t) for the total electric microfield of the electrons on positive charge impurity embedded in a plasma are considered when the relativistic dynamic of the electrons is taken into account. We have, at first, built the effective potential governing the electrons dynamics. This potential obeys a nonlinear integral equation that we have solved numerically. Regarding the electron broadening of the line in plasma, we have found that when the plasma parameters change, the amplitude of the collision operator changes in the same way as the time integral of Cee(t). The electron-impurity interaction is taken at first time as screened Deutsh interaction and at the second time as Kelbg interaction. Comparisons of all interesting quantities are made with respect to the previous interactions as well as between classical and relativistic dynamics of electrons

The Factors Impact Information Technology Adoption Among Employees at Tax Authority of Yemen

Information is powerful. This great statement led to do this research by seeing information technology power in developing several countries such as Malaysia. Due to the increased organizational dependence on information systems and technology, most of today's organizations and governments have plans to implement information technology in all of their job processing and communication tools. This study aims to describe the current state of information technology adoption among employees in Tax Authority of Yemen and to find the relationship with complexity, compatibility, and relative advantages. To deepen the analysis, reliability test has been done, then, study used liner regression to test the hypothesis. Moreover, descriptive statistics was computed to describe the current state of information technology adoption by using tables, charts and graphs to present the findings in an understandable manner. As a result of the study relative advantages has the highest relationship, then compatibility, and complexity. This research provided some recommendations through its results both can help the top management of tax authority of the Republic of Yemen push growing of information technology implementation

The role of imaging in advancing the understanding of the pathogenesis, diagnosis and staging of central chondroid bone tumours

Central chondroid bone tumours are one of the most common primary bone tumours. Benign central chondroid tumours are termed enchondromas and its malignant counterpart are called chondrosarcomas. Enchondromas are frequently observed on routine imaging. Similarly, chondrosarcomas are the second most common primary bone tumour after osteosarcoma. Imaging is crucial in the diagnosis of central chondroid tumours and in the differentiation of enchondromas from chondrosarcomas. Furthermore, imaging plays a vital role in the staging of chondrosarcomas. In this thesis, the published scientific literature on the role of imaging in the diagnosis of benign chondroid tumours and chondrosarcomas and the role of imaging in the staging of chondrosarcomas is reviewed and summarised. Furthermore, the contribution of the authors’ published work is highlighted in the thesis. The first two articles are review articles which discuss the clinical and imaging features of benign and malignant chondrogenic tumours and the significance of imaging in the diagnosis of these tumours. The third article is an original article which investigates the theory of the pathogenesis of enchondromas. It is widely believed that enchondromas arise from cartilage islands which are displaced from the growth plate during the process of skeletal maturation. However, this theory is unproven, and the origin of this theory was forgotten prior to the authors’ study. Based on the incidental prevalence of enchondromas of the knee in the adult population of 2.9%, the study assesses the prevalence of cartilage islands/enchondromas in skeletally immature patients. In this study, no cartilage islands/enchondromas in skeletally immature patients were identified. The study therefore shows the rarity of enchondromas in skeletally immature individuals which is in contrast to the adult population. Furthermore, in view of the absence of cartilage islands in this study, the study raises doubts about the validity of the unproven theory. Lastly, the very origin of this theory is rediscovered in this thesis which has been forgotten in modern medicine. The fourth article is an original article which evaluates the role of diffusion-weighted MRI (DWI) in the diagnosis of central cartilage tumours. Prior to the authors’ study the role of DWI in the diagnosis of central cartilage tumours was uncertain. The authors’ study demonstrates that DWI cannot be used to differentiate between enchondromas and chondrosarcomas and that DWI does not aid in the distinction of low-grade chondroid tumours from high-grade chondrosarcomas. This is a finding which was not known prior to the study. The fifth article is an original article which assesses the utility of conventional MRI in the differentiation of low-grade from high-grade chondrosarcomas of long bone. Prior to the authors’ study the role of conventional MRI in the differentiation of low- grade from high-grade chondrosarcomas of long bone was unknown. The authors’ study shows that bone expansion, active periostitis, soft tissue mass and tumour length can be used to differentiate high-grade from low-grade chondral lesions of long bone on conventional MRI. Furthermore, the presence of these four MRI features shows a diagnostic accuracy of 95.6%. These findings were not known prior to the study and have significantly furthered the knowledge about the role of conventional MRI in the grading of chondrosarcoma of long bone. The sixth article is an original article which evaluates the role of bone scintigraphy and Computed Tomography of the chest in the staging of chondrosarcoma of bone. Whilst guidelines regarding the staging of bone sarcomas state that bone scintigraphy should be performed to assess for the presence of skeletal metastases and that Computed Tomography (CT) of the chest should be performed to evaluate for possible pulmonary metastases, there has been no research on the utility of bone scintigraphy in chondrosarcoma of bone and on the role of CT-chest in the staging of chondrosarcomas. Furthermore, the prevalence of skeletal and pulmonary metastases of chondrosarcoma at presentation was unknown prior to this study. The authors’ study demonstrated no skeletal metastases on bone scintigraphy in chondrosarcoma of bone at presentation. In contrast, pulmonary metastases were observed in approximately 5% of all patients with chondrosarcoma at presentation on CT-chest. The finding therefore demonstrates the rarity of skeletal metastases in chondrosarcoma of bone at presentation which is in contrast to osteosarcoma and Ewing sarcoma. The study therefore concludes that there is little role for skeletal scintigraphy in the surgical staging of chondrosarcoma. In contrast, the study shows that there is a role for CT-chest in the staging of chondrosarcoma. These above described findings are important new findings and represent a significant contribution to the knowledge base regarding metastatic behaviour of chondrosarcomas at presentation and regarding the staging of chondrosarcoma of bone. In summary, the authors’ publications have significantly enhanced and furthered the understanding of the pathogenesis of enchondromas, the role of functional MRI in the differentiation of enchondromas from chondrosarcomas, the utility of MRI in the grading of chondrosarcomas and the role of skeletal scintigraphy in the staging of chondrosarcomas

Moderating effect of employee's commitment to change on the relationship between leadership styles and employee's readiness to change in Yemen

Change in the public sector is one of the main concerns due to its critical role in enhancing the public sector which consequently contributes to the development of the economy and society. Yemen as a least developed country, its employees of public sector were unable to implement the changes planned. Besides, there is a gap in the literature in terms of examining the influencing and moderating factors that could affect the employee’s readiness to change. The aim of this thesis is to examine the effects of transformational leadership (TFL) style, transactional leadership (TAL) style and employee’s commitment towards change (ECC) on the employee’s readiness to change (ERC). The thesis also examines the moderating effect of ECC on the relationship between the two leadership styles (TFL and TAL) with ERC. The thesis utilizes Lewin's model and Social Exchange Theory (SET) as guiding theories and employs cross-sectional survey. The questionnaires were administered to collect data from the employees of the public sector in Yemen. Out of 768 questionnaires distributed through a self-administered approach, 387 usable responses were used for the analysis. By using Partial Least Square-Structural Equation Modeling, the findings show significant effects of TFL and ECC on the ERC. Furthermore, the findings show that TAL is not significantly related to ERC among the employees of the public sector in Yemen. Additionally, the findings reveal that ECC is a significant moderator on the relationship between TAL and ERC. These findings provide theoretical and practical implications. It contributes towards the body of knowledge of how employees are ready to changes in the public sectors of a least-developed country. It also provides significant insights in explaining a roadmap that help in understanding the most influential factors on employee’s readiness to change in a least developed country namely Yemen

The Impact of Capital Account Liberalization on Financial Stability in Algeria – A Benchmark Study for the Period (1990-2014)

تهدف هذه الدراسة إلى اختبار تأثير تحرير حساب رأس المال لميزان المدفوعات على الاستقرار المالي في الجزائر، وهذا عبر دراسة العلاقة بين حساب رأس المال ومؤشرات التوازن الداخلي والخارجي للاقتصاد الجزائري مستعملين في ذلك بيانات احصائية سنوية للفترة 1990-2014 على اعتبار سنة 1990 هي بداية التحرير التدريجي لحساب رأس المال في الجزائر،  وقد أستعملنا معامل الارتباط لبيرسون واختبار سببية جرانجر لتحديد طبيعة العلاقة الموجودة بين متغيرات الدراسة. وقد بينت النتائج عدم وجود علاقة ارتباط قوية بين متغيرات الدراسة وتفسير ذلك كون الاستقرار المالي المحقق في الفترة من 2001 إلى 2014 لم يكن نتيجة تحرير حساب رأس المال بل يعود لارتفاع أسعار النفط.This study aims to test the impact of liberalization of the capital account of the balance of payments on financial stability in Algeria, This is by examining the relationship between the capital account and the internal and external balance indicators of the Algerian economy using annual statistical data for the period 1990-2014 as the year 1990 is the beginning of gradual liberalization of the capital account in Algeria. We used Pearson's correlation coefficient and Granger's causal test to determine the nature of the relationship between the variables of the study, The results showed that there was no strong correlation between the variables of the study and the interpretation that the financial stability achieved in the period from 2001 to 2014 was not the result of liberalization of the capital account, but due to high oil prices

The hyperdense middle cerebral artery sign in a polycythaemic child

The hyperdense middle cerebral artery (HMCA) sign is known to be an early sign of intracranial arterial occlusion or infarction during unenhanced CT imaging of the brain.1 This sign has also been seen after treatment with bromide,2 in cocaine abusers3 and in adults with elevated haematocrit,4 but has not previously been reported to be a result of polycythaemia in children

Primary retroperitoneal soft tissue sarcoma: Imaging appearances, pitfalls and diagnostic algorithm.

Although retroperitoneal sarcomas are rare tumours, they can be encountered by a wide variety of clinicians as they can be incidental findings on imaging or present with non specific symptoms and signs. Surgical resection can offer hope of cure and patient outcomes are improved when patients are managed in high-volume specialist centers. Failure to recognize retroperitoneal sarcomas on imaging can lead to inappropriate management in inexperienced centers. Therefore it is critical that a diagnosis of retroperitoneal sarcoma should be considered in the differential diagnosis of a retroperitoneal mass with prompt referral to a soft tissue sarcoma unit. In particular, the most common retroperitoneal sarcoma subtypes, liposarcoma and leiomyosarcoma, have characteristic imaging appearances which are discussed. This review therefore aims to set the context and guide clinicians through a diagnostic pathway for retroperitoneal masses in adults which arise extrinsic to the solid abdominal viscera

Whole-body MRI in the diagnosis of paediatric CNO/CRMO

Chronic recurrent multifocal osteomyelitis (CRMO) is an auto-inflammatory disorder affecting the skeleton of children and adolescents. Whole-body MRI (WBMRI) is key in the diagnosis and follow-up of CRMO. Imaging protocols should include sagittal short Tau inversion recovery of the spine, imaging of the hands and feet, and T1 images for distinguishing normal bone marrow. CRMO lesions can be metaphyseal, epiphyseal and physeal—potentially causing growth disturbance and deformity. Spinal lesions are common, important and can cause vertebral collapse. Lesion patterns include multifocal tibial and pauci-focal patterns that follow a predictable presentation and course of disease. Common pitfalls of WBMRI include haematopoietic marrow signal, metaphyseal signal early on in bisphosphonate therapy and normal high T2 signal in the hands and feet. Pictorial reporting assists in recording lesions and follow-up over time. The purpose of this paper is to review the different WBMRI protocols, imaging findings, lesion patterns and common pitfalls in children with CRM

ECCO Essential Requirements for Quality Cancer Care : Soft Tissue Sarcoma in Adults and Bone Sarcoma. A critical review

Background: ECCO essential requirements for quality cancer care (ERQCC) are checklists and explanations of organisation and actions that are necessary to give high-quality care to patients who have a specific tumour type. They are written by European experts representing all disciplines involved in cancer care. ERQCC papers give oncology teams, patients, policymakers and managers an overview of the elements needed in any healthcare system to provide high quality of care throughout the patient journey. References are made to clinical guidelines and other resources where appropriate, and the focus is on care in Europe. Sarcoma: essential requirements for quality care Sarcomas - which can be classified into soft tissue and bone sarcomas - are rare, but all rare cancers make up more than 20% of cancers in Europe, and there are substantial inequalities in access to high-quality care. Sarcomas, of which there are many subtypes, comprise a particularly complex and demanding challenge for healthcare systems and providers. This paper presents essential requirements for quality cancer care of soft tissue sarcomas in adults and bone sarcomas. High-quality care must only be carried out in specialised sarcoma centres (including paediatric cancer centres) which have both a core multidisciplinary team and an extended team of allied professionals, and which are subject to quality and audit procedures. Access to such units is far from universal in all European countries. It is essential that, to meet European aspirations for high-quality comprehensive cancer control, healthcare organisations implement the requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis and follow-up, to treatment, to improve survival and quality of life for patients. Conclusion: Taken together, the information presented in this paper provides a comprehensive description of the essential requirements for establishing a high-quality service for soft tissue sarcomas in adults and bone sarcomas. The ECCO expert group is aware that it is not possible to propose a 'one size fits all' system for all countries, but urges that access to multidisciplinary teams is guaranteed to all patients with sarcoma. (C) 2016 The Authors. Published by Elsevier Ireland Ltd.Peer reviewe