Synthesis of some organotin monomers and copolymerisation with acrylic monmers

The aim of this thesis was to synthesise new organotin monomers based on Nsubstituted acrylamide and methacrylamide and on acrylic acid and methacrylic acid esters with pendant hydrolysable organotin moieties and to study their copolymerisation with methyl acrylate (MA), butyl acrylate (BA) and methyl methacrylate (MMA). A specific objective was to obtain suitable macromolecular chains, to which the organotin moieties could be attached at some distance from the main backbone. The new organotin monomers which were synthesised are: m-acrylamidotri-n-butyltin benzoate (m-AATBTB), p-acrylamidotri-n-butyltin benzoate (p-AATBTB), m-methacrylamidotri-n-butyltin benzoate (mMAATBTB), p-methacrylamidotri-n-butyltin benzoate (p-MAATBTB), 0- acryloyloxytri-n-butyltin benzoate (o-AOTBTB) and o-methacryloyloxytri-nbutyltin benzoate (o-MAOTBTBO). These were prepared by the reaction of bis(tri-n-butyltin) oxide (TBTO) with the corresponding acrylamide or acryloyloxy benzoic acid which were prepared by the reaction of aminobenzoic acid derivatives or salicylic acid with either acryloyl chloride or acrylic anhydride. These organotin monomers were polymerised in dimethylformamide (DMF) solution with azobisisobutyronitrile (AIBN) as initiator. Binary copolymerisation experiments were performed by solution polymerisation in DMF solution with AIBN as initiator. The copolymer composition in each case was determined from tin analysis. Since the properties of these organotin polymers are related to the distribution of monomer units, it is of great interest to determine the actual monomer reactivity ratios which control the sequence length distribution. Monomer reactivity ratios were calculated by the KelenTudos method. All of these organotin polymers and copolymers were characterised by Nuclear magnetic resonance spectroscopy (NMR) and Fourier Transform infrared spectroscopy (FTIR) methods, gel permeation chromatograghy (GPC) and dynamic mechanical thermal analysis (DMTA)

The Omani sandfish sea cucumber, Holothuria scabra Jaeger, 1833 (Holothuroidea: Holothuriidae): Fishery, length-Weight relationship and condition factor

The fishery of Omani sea cucumber, Holothuria scabra, is limited so far to the Mahout Bay in Al Wusta governorate. This fishery supports an uncertain number of fishermen ranging from 100 to 150. This fishery is not well-studied and has no current management program. In order to prepare a management strategy, the government has suspended this fishery for 2 years from March 2018 to March 2021. Apart from presenting a thorough review on the sea cucumber fishery in Oman, the current work presents a detailed analysis of the length–weight relationship, sex ratio, and condition factor of the H. scabra collected from four different areas during the period February-May 2019. Based on the results, the females were longer than males, that is 226±33.4 and 221±37.8 mm, respectively. The overall sex ratio of the entire/pooled sample was 0.49 which was not different from the anticipated theoretical sex ratio of 0.5. The mean Kn and the empirical weight–length equations for the total sample were between 0.12±0.01 and 1.0±0.16, and W=0.03L1.6, respectively

Assessment of Glomerular Filtration Rates by Cockcroft-Gault and Modification of Diet in Renal Disease Equations in a Cohort of Omani Patients

Objectives: Glomerular filtration rate (GFR) is the best index of renal function and is frequently assessed by corrected creatinine clearance (CCLcr). The limitations of CCLcr have inspired researchers to derive easy formulas to estimate GFR, with Cockcroft-Gault (C-G) and the modification of diet in renal disease (MDRD) being the most widely used. This study aimed to evaluate the validity of these equations by finding the relation between CCLcr and estimated GFR (eGFR) by C-G, modified C-G and MDRD equations. Methods: From 2007 to 2011, 158 subjects were analysed for serum creatinine and CCLcr at Bowsher Polyclinic, Muscat, Oman. The C-G equation was used to obtain eGFRC-G which was adjusted to body surface area (BSA) to obtain eGFRmC-G, and the MDRD equation was used to obtain eGFRMDRD. The eGFRMDRD, eGFRmC-G and eGFRC-G were then compared to CCLcr. Results: The eGFRMDRD, eGFRmC-G and eGFRC-G significantly correlated with CCLcr, with a slightly stronger correlation with eGFRMDRD (r = 0.701, 0.658 and 0.605, respectively). A receiver operating characteristic curve analysis showed that the diagnostic accuracy of eGFRMDRD for diagnosing chronic kidney disease (CKD) was higher than that of eGFRmC-G, which in turn was higher than that of eGFRC-G (area under the curve was 0.846, 0.831, and 0.791; cut-off limits were 61.9, 58.3 and 59.5, respectively). Conclusion: C-G and MDRD equations can be an alternative to the CCLcr test for assessing GFR, thus avoiding the need for the cumbersome and expensive GFR test. The MDRD formula had greater validity than the C-G equation and the C-G equation validity was improved by an adjustment to BSA

Investigating quality of life and communication in Saudi Arabian individuals with progressive dysarthria

One functional factor commonly affected by neurodegenerative diseases is communication. Many people with neurodegenerative disease experience a progressive motor speech disorder: dysarthria. It is known that communication is essential for full social participation but there is limited evidence on the role it plays in quality of life (QoL). The aim of this thesis is to explore the QoL of Saudi Arabian individuals with progressive dysarthria associated with neurodegenerative disease. The thesis includes the development of new intelligibility and functional communication measures for use with an Arabic speaking population. It also explores the relationship between QoL and communication for individuals with neurodegenerative disease. Qualitative and quantitative research methodologies were used. Research participants were recruited from a specialist hospital in Riyadh, Saudi Arabia. 16 people participated in the first part and 34 in the second, all of whom had been diagnosed with neurodegenerative disease associated with different severities of progressive dysarthria. In addition, caregivers participated to explore the difference between their perceptions of participants’ QoL and functional communication and that of the participants themselves. It was established that QoL, as measured by the ASIP, showed the most frequent relationship with functional measures of communication. Additionally, qualitative analysis of interviews highlighted themes related to physical, psychological, social, and environmental factors. Communication was mainly discussed in relation to changes and restrictions in participation and interaction. Finally caregiver and patient perspectives were found to be similar when asked to rate the participants’ QoL and functional communication. Although this research is not without limitations as reflected by some of the methodologies used as well as variable population features within the disease groups, it is an important first step in looking at a Saudi Arabian population with progressive dysarthria and exploring methods for assessing intelligibility, functional communication and the relationship between communication and QoL

Conceptual Understanding for Systems of Linear Equations: Difficulties and Challenges

The conceptual understanding of algebraic concepts is challenging to students, adds to the challenge of teaching them. This study aimed to reveal the level of conceptual understanding about Systems of Linear Equations (SLEs) and its difficulties that faced students while they solving problems. The study sample consisted of (68) male and female students of linear algebra course. The conceptual understanding test was prepared with two qualitative and quantitative rubrics to classify students’ levels. The study results showed a decrease in the conceptual understanding of SLEs in general, and in the area of realizing the relationships between concepts related to SLEs in particular. In contrast, the level of conceptual understanding of students was medium in the context of multiple representations. The results also showed many difficulties that students face while solving SLEs. The study recommended the need to focus on the conceptual understanding of concepts related to SLEs and to use multiple representations and connect them together when teaching mathematical concepts

LEADERSHIP STYLE AMONG MIDDLE MANAGERS IN SAUDI MINISTRY OF HEALTH

Background: Middle managers within ministry of health act under continuous pressure from board level to be successful leaders of today's and tomorrow's healthcare service. Leadership styles are important factors among middle managers to retain employees in organizations and to ensure a high quality of practice.Aims: Two main aims: to examine the leadership style(s) of middle managers as perceived by them as leader from different departments of the Saudi Ministry of Health, and to examine the leadership style(s) of the middle managers as perceived by their subordinates as raters from different departments of the Saudi Ministry of Health.Materials and methods: A cross-sectional descriptive design was used to answer the research questions. A convenience sample of 121 participants, 30 middle managers and 91 subordinates, who were recruited through different departments at Saudi Ministry of Health during the period of June 2010 through September 2010.Participants were subjected to Univariate and Multivariate analysis. The Multifactor Leadership Questionnaire (MLQ) was used to collect data.Results: the mean ratings of all four components of transformational leadership for the subordinates and middle managers were between 2.90 to 3.29 .The mean ratings for contingent reward and management by exception active were 3.30 and 2.50 respectively and this was well within the optimum range as suggested by Bass. Management by exception passive and laissez-faire showed mean ratings of 1.67 and 1.25 respectively. The correlation coefficients among transformational leadership style and each variable of, satisfaction, effectiveness and extra effort for raters and leaders sample was high positively reached (r = .72, p< 0.05) , (r = .81, p< 0.05) , (r = .80, p< 0.05) respectively, The correlation coefficients among transactional leadership style and each variable of, satisfaction, effectiveness and extra effort for raters and leaders sample was high positively reached (r = .20, p<0.05) , (r = .44, p< 0.05) , (r = .35, p< 0.05) respectively, and The correlation coefficients among laissez -Faire leadership style and each variable of, satisfaction, effectiveness and extra effort for raters and leaders sample was high negatively reached (r = -.48, p< 0.05) , (r = -.46, p< 0.05) , (r = -.43, p< 0.05) respectively. There are agreement between leaders and raters on transformational, transactional and laissez-faire as distributive in Saudi Ministry of Health in kingdom of Saudi Arabia. The result showed there was no significant difference on the MLQ factors for raters and Leader due to gender, marital status, and age. Also , the analysis showed significant differences among raters’ opinions due to work experiences as contingent reward and extra effort in favor of raters who experience of them more than ˃ 6 Month, and finally, the analysis showed there significant differences among raters’ opinions due to period working with leaders as transformational, idealized Influence attributed, inspirational motivation, intellectual stimulation, contingent reward, and effectiveness in favor of raters who working with leaders for a period between 6 months - ˂ 1 year, but significant differences among raters’ opinions due to period working with leaders as Laissez –Faire in favor of raters who working with leaders for a period between 1 year - 2 years.Conclusions: transformational leadership can contribute a lot to the effectiveness of organizations and that there is a need for further investigation of leadership at different levels

Cone Penetration Testing For Field Density Prediction

This paper summarizes an experimental program for developing a pilot procedure to check and predict field densities of compacted soils using static cone penetration tests. Three sandy soils were tested. The testing program included both laboratory and field tests. On the basis of laboratory tests, density prediction curves were developed while field results were used to find a correlation to predict densities on the basis of measured penetration resistances. The results are rather encouraging and promising. It is anticipated that the presented methodology would be very effective for compaction quality control in large areas of sandy soils because it is fast, simple and causes minimum disturbance to the compacted soil

Evaluation of length-weight relationship for a native goby, Awaous jayakari (Teleostei: Gobiidae) in the Middle East

Parameters of length-weight relationship of freshwater and marine fishes have long been of interest as a longstanding theme fisheries sciences and have been estimated for many fishes around the world. In this study, for the first time, length weight relationship (LWR) was estimated for a native fish, the long nose goby Awaous jayakari (Gobiidae) collected from the inland waters of Oman in 2020 using foldable shrimp and crab fishing traps (mesh size of 3*3mm). The parameter of b for male and female specimens based on standard length (SL) was within the range of 2.666-4.377 and 2.852-3.374 respectively. As proposed for different fishes there was high and significant correlation coefficients with between length and weight of (0.970-0.983). Bailey’s ‘t’ test revealed that b value significantly deviated from 3 for both males and females