2D Monolithic silicon detectors for dosimetry in Small beam radiotherapy (Stereotactic Radiotherapy)

Radiation Therapy is one type of cancer’s treatment, which aims to kill or control tumour cells by using high energy radiation. However, it can affect both normal and tumour cells. Due to that, scientists worked to develop a new treatment technique of radiation delivery that focuses the high prescribed dose on the small localized area of tumour cells and protects the normal cells. This focal irradiation technique is called Stereotactic Radiosurgery (SRS). Using SRS allows the treatment of hard-to-reach lesions where surgery is not possible because of the risks resulting in the surgical procedures. The commissioning and Quality Assurance of SRS/SRT is complex and requires special dosimetry tools. Poor dosimetry of small-field characteristics may lead to reduced treatment efficacy, whether by under-dosage of targeted tumours or overirradiation of adjacent healthy tissues. Poor measurements of the small field characteristics, such as FWHM, penumbra width, output factors and percentage depth dose may result in pernicious health consequences, such as radiation-induced carcinogenesis. Hence, the dosimetry tool plays an important role in the SRS/SRT accuracy and precise delivery. Recently, silicon detectors have increased in popularity because they have high spatial resolution, small sensitive volume, high sensitivity to radiation, reasonable uniformity and provides real time measurements. The Centre for Medical Radiation Physics (CMRP) has developed two innovative monolithic silicon array detectors, DUO and OCTA, to be used in SRS/SRT for pretreatment quality assurance dosimetry. Therefore, the aim of this thesis is to characterise these two monolithic silicon detectors for small radiation field dosimetry employed in stereotactic radiotherapy

T-lymphocyte/monocyte interactions in relation to inflammatory joint diseases

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Diversity, distribution and conservation of the terrestrial reptiles of Oman (Sauropsida, Squamata)

All authors: Salvador Carranza , Meritxell Xipell, Pedro Tarroso, Andrew Gardner, Edwin Nicholas Arnold, Michael D. Robinson, Marc Simó-Riudalbas, Raquel Vasconcelos, Philip de Pous, Fèlix Amat, Jiří Šmíd, Roberto Sindaco, Margarita Metallinou †, Johannes Els, Juan Manuel Pleguezuelos, Luis Machado, David Donaire, Gabriel Martínez, Joan Garcia-Porta, Tomáš Mazuch, Thomas Wilms, Jürgen Gebhart, Javier Aznar, Javier Gallego, Bernd-Michael Zwanzig, Daniel Fernández-Guiberteau, Theodore Papenfuss, Saleh Al Saadi, Ali Alghafri, Sultan Khalifa, Hamed Al Farqani, Salim Bait Bilal, Iman Sulaiman Alazri, Aziza Saud Al Adhoobi, Zeyana Salim Al Omairi, Mohammed Al Shariani, Ali Al Kiyumi, Thuraya Al Sariri, Ahmed Said Al Shukaili, Suleiman Nasser Al Akhzami.In the present work, we use an exceptional database including 5,359 records of 101 species of Oman’s terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman’s 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).This work was funded by grants CGL2012-36970, CGL2015-70390-P from the Ministerio de Economía y Competitividad, Spain (cofunded by FEDER) to SC, the project Field study for the conservation of reptiles in Oman, Ministry of Environment and Climate Affairs, Oman (Ref: 22412027) to SC and grant 2014-SGR-1532 from the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya to SC. MSR is funded by a FPI grant from the Ministerio de Economía y Competitividad, Spain (BES-2013-064248); RV, PT and LM were funded by Fundação para a Ciência e Tecnologia (FCT) through post-doc grants (SFRH/BPD/79913/2011) to RV, (SFRH/BPD/93473/2013) to PT and PhD grant (SFRH/BD/89820/2012) to LM, financed by Programa Operacional Potencial Humano (POPH) – Quadro de Referência Estrategico Nacional (QREN) from the European Social Fund and Portuguese Ministerio da Educação e Ciência

From Policy to Practice: School-Based Assessment of Omani Students’ Science Learning in Basic Education Schools

This qualitative study focuses on understanding how science teachers in Basic Education in Oman enact a national initiative in the New Assessment System (NAS), which focuses on Assessment for Learning (AFL) in science education. It also examines the influence of contextual factors on teachers’ actual practices while enacting the NAS policy. Data-gathering methods were observations, interviews and document analysis. Ten Ministry of Education (MOE) policymakers and fifteen practitioners in Grade 5-10 schools participated. The research questions address the policy intentions behind NAS, how science teachers enact the system, the factors influencing their enactment and the extent of alignment between policy intentions and teachers’ practices. While the findings have pointed that although there is a concurrence between the MOE policy intentions that NAS should function as AFL, and practitioners’ perspectives on them, the reality of NAS policy enactment was not entirely consistent with the NAS policy intentions, and the extent of this alignment depends on the contextual factors. This gap can be attributed to the absence of a consultation in the policy development process and the weakness of policy enactment reinforcement, such as the inadequacy of professional development. Moreover, this is due to the absence of a specific accountability framework, and of a particular body that enforces accountability, as well as the absence of self-accountability, a lack of interest in the teacher agency, and the influence of contextual factors on the adaptation of borrowed policy. The most prominent of this study’s contributions to the current literature is that it contributes towards filling a gap in it regarding both AFL policy enactment in science education in the Eastern context, and the consultation stage in policy development in educational studies. The study also extends the current literature with further examples of the influence of contextual factors on the professional development of practitioners. Finally, this study contributes to filling an important gap in the current literature regarding the critical aspects that are associated with the NAS enactment, such as policy borrowing, teacher agency, moderation, and self-accountability for the policy enactment

New faunistic records of cockroaches (Insecta: Blattodea) from Oman

The knowledge of Blattodea from Oman is still incipient. One species of cockroaches are reported from Oman so far and this indicates the large blank in our knowledge in this order when compared to recorded species from other neighboring countries in the Arabian Peninsula.  Blattodea have been collected at various localities in Sultanate of Oman with different sampling artifacts. The present communication records five species of cockroaches from Oman, namely Blattella biligata (Walker, 1868), Heterogamisca Bey-Bienko, 1950, Pycnoscelus surinamensis (Linnaeus, 1758), Tivia fusca Bohn, 2008 from northern Oman and Neostylopyga rhombifolia (Stoll, 1813) from southern Oman

Effect of gum arabic on oxidative stress and inflammation in adenine-induced chronic renal failure in rats

Inflammation and oxidative stress are known to be involved in the pathogenesis of chronic kidney disease in humans, and in chronic renal failure (CRF) in rats. The aim of this work was to study the role of inflammation and oxidative stress in adenine-induced CRF and the effect thereon of the purported nephroprotective agent gum arabic (GA). Rats were divided into four groups and treated for 4 weeks as follows: control, adenine in feed (0.75%, w/w), GA in drinking water (15%, w/v) and adenine+GA, as before. Urine, blood and kidneys were collected from the rats at the end of the treatment for analysis of conventional renal function tests (plasma creatinine and urea concentration). In addition, the concentrations of the pro-inflammatory cytokine TNF-a and the oxidative stress markers glutathione and superoxide dismutase, renal apoptosis, superoxide formation and DNA double strand break frequency, detected by immunohistochemistry for c-H2AX, were measured. Adenine significantly increased the concentrations of urea and creatinine in plasma, significantly decreased the creatinine clearance and induced significant increases in the concentration of the measured inflammatory mediators. Further, it caused oxidative stress and DNA damage. Treatment with GA significantly ameliorated these actions. The mechanism of the reported salutary effect of GA in adenine-induced CRF is associated with mitigation of the adenine-induced inflammation and generation of free radicals

IMPACT OF LEADERSHIP STYLE ON ELECTRONIC COMMERCE ADOPTION AMONG SME: A CASE OF AD DAKHILIYYAH GOVERNORATE IN OMAN

Today's rapidly evolving technology has an impact on businesses as it offers new ways and means of conducting business. Undoubtedly, e-commerce has created new opportunities to change the way businesses operate. In such a critical situation, leaders need to develop visions and make important preparations to keep their companies afloat. The Multifactor Leadership Questionnaire (MLQ) was used to explore the relationship between leadership style and e-commerce adoption among managers of small and medium enterprises (SMEs) in Ad Dakhiliyah Governorate. Managers of 9104 SMEs in Ad Dakhiliyah responded to the questionnaire with 367 responses. SmartPLS 4 was used to analyse the data. The study found that there is a significant and positive relationship between transactional leadership and e-commerce adoption. However, the results show that there is a positive but not significant relationship between transformational leadership and e-commerce adoption. This study has important implications for how SME managers should demonstrate the right leadership style to support e-commerce adoption. This study provides SME managers with a better knowledge of the influence of leadership style on the adoption of e-commerce in Ad Dakhiliyah. Keywords: Leadership Style, E-commerce, Technology Adoption, SME, Oman, SmartPLS

Psychological Symptoms of COVID-19 Pandemic Among Community-Dwelling Older People in Oman and Associated Risk Factors

Introduction The COVID-19 pandemic has led to a dramatic loss of human lives worldwide. Objective This study aimed to investigate the psychological factors of the COVID-19 pandemic in the community-dwelling older population. Method This was a cross-sectional study of older people aged ≥60 years with no mental or psychological illnesses. A total of 193 participants were recruited. The study questionnaire included anxiety- and depression-related questions tailored for the COVID-19 pandemic. The questionnaire was developed through a literature review and expert review. Data was collected from December 2020 to January 2022. Results The psychological symptoms of COVID-19 were high in this sample (mean 29.18 ± 3.57). Gender (female) was found to have a strong positive relationship with the psychological symptoms of COVID-19 score ( p  = 0.003). Chronic illnesses (β = 0.19, p  < 0.001), living alone (β = 0.39, p  < 0.001), and having a family member or a friend with COVID-19 (β = 0.15, p  < 0.001) were also found to have a strong positive relationship with the psychological symptoms of COVID-19 score. Conclusion The negative psychological effects of COVID-19 were high among the older population in Oman. In this study, female gender, chronic illnesses, living alone, and having a family member or a friend with COVID-19 were associated with worse COVID-19 psychological symptoms. Older women were affected by COVID-19 more than older men. In addition, those who had chronic illnesses, lived alone, or had a family member or a friend with COVID-19 were more psychologically burdened by the pandemic than those without those characteristics. Particular attention should be given to older adults who have chronic illnesses, live alone, or have a family member or a friend with COVID-19. Support groups and psychological counseling programs are essential for older people during a pandemic

Representative pictures of superoxide formation visualized by using the dye dihydroethidium on kidney cryosections (A). Superoxide (B) and DNA double strand break formation (C) in control rats, rats treated with gum arabic (15% w/v in drinking water) and rats treated with adenine (0.75% w/w) alone in feed, or with adenine and gum arabic given concomitantly at the same dose for 28 days.

<p>Each column and vertical bar represents the mean ± SEM (n = 5). ** p<0.01, *** p<0.001 vs. control, ^## p<0.01, ^### p<0.001 vs. adenine treatment.</p