http://hdl.handle.net/123456789/8519 KSU Higher Education Search the Channel search http://repository.ksu.edu.sa/jspui/simple-search http://hdl.handle.net/123456789/8823 Title: Effect of the communicative approach on the listening and speaking skills of Saudi secondary school students: an experimental study<br/><br/>Authors: Al-Twairish, Badriah Nasser<br/><br/>Abstract: This thesis attempts to measure the effect of the implementation of the communicative approach (CA) on the listening and speaking skills of Saudi third year secondary students. In order to address this issue, aquantitative study was conducted on two randomly selected intact classes at Dammam Tenth Secondary School. These two classes were assigned as experimental group (37 students) and control group (41 students). Itwas particularly hypothesized that the students taught according to the CA would score higher in the post-test than in the pre-test and that there would be statistically significant differences at the level of .05 between the post-test mean scores of the experimental group and the control group. Various communicative activities were used with the experimentalgroup while the control group was exposed to traditional, non communicative, instruction using structurally based methods, such as theaudio-lingual method. A pre-test was administered to both groups at thebeginning of the experiment to ensure that they had the same language background. At the end of the experiment, a post-test was assigned to both groups to determine whether the CA had positively affected the students' listening and speaking abilities. The experiment lasted approximately seven weeks of the first semester of 1428 (2007). The study has revealed that: (1) the CA had a positive effect on the students' listening and speaking skills; (2) the experimental group obtained somewhat higher scores in the post-test than in the pre-test, making the difference between the pre-test and post-test scores statistically significant; (3) the difference between the pre-test and the post-test for the control group was not statistically significant; and (4) the experimental students were more differentiated than the control students,as shown by a statistically significant difference between the mean scores of both groups in the post-test in favor of the experimental students. In light of these results, the following recommendations were made:(1) that a shift should be made from non-communicative to communicative ELT; (2) that educational policy-makers should consider the applicability of the CA in the Saudi context; (3) that EFL teachersshould receive in-service training in applying CA principles; (4) that students should be encouraged to speak the target language with their colleagues; and (5) that local ELT textbook writers should work alongcommunicative lines.<br/><br/>Description: This study has been conducted & submitted to the Deanship of Higher studies in partial fulfillment of the requirements for the Master's Degree in Applied Linguistics in Department of English Language and Literature, King Saud University, Riyadh, Kingdom of Saudi Arabia, 1430H - 2009G Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/123456789/8663 Title: Efficacy of two rotary niti instruments in the removal of gutta-percha during root canal retreatment. An in vitro study.<br/><br/>Authors: AL-Katheeri, Nasser Hamad<br/><br/>Abstract: The aim of this study was to evaluate the efficacy of two rotary NiTi instruments,ProTaper and K3, in the removal of gutta-percha during root canal retreatment incomparison with hand instruments using Hedstrom files. Retreatment time and amount ofapically extruded debris were also recorded and evaluated. Sixty extracted single-rootedanterior teeth and premolars were instrumented to size # 40 and obturated with laterallycondensed gutta-percha using AH-26 sealer cement. The teeth were randomly dividedinto three groups, 20 teeth each. Removal of gutta-percha was performed with chloroformand one of the following techniques; (I) Hedstrom files, (II) ProTaper, and (III) K3. Theroots were split longitudinally and digitized using scanner. The area of the whole canal,the area of each third, and the area of remaining filling materials in the whole canal andin each third were traced using Ulead Photoimpact7 then calculated using SigmaScansoftware. The remaining filling materials were expressed in percentage. The resultsindicated that the two rotary NiTi instruments left significantly less remaining materials(P < 0.0001) compared to Hedstrom files while there was no significant differencebetween the two rotary instruments. In all groups the apical thirds showed the highestratio of remaining materials compared to middle and coronal thirds. The retreatment timewas significantly less (P < 0.0001) when the two rotary NiTi instruments were usedcompared to hand. There was no statistically significant difference (P = 0.159) foundbetween the three techniques regarding the amount of apically extruded debris. Inconclusion, the two rotary NiTi instruments, ProTaper and K3 were found to be effective<br/><br/>Description: This study is conducted & submitted in partial fulfillment of the requirements for theMaster of Science degree in Dentistry in the Department of Restorative Dental Sciences,Division of Endodontics, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia, Rabi-II 3 1426H - May-11 2005G Wed, 11 May 2005 00:00:00 GMT http://hdl.handle.net/123456789/8618 Title: Mechanism(s) of the potential protective effects of selected antioxidants against immunosuppression–induced by psychic stress in rats<br/><br/>Authors: AL-Aboodi, Ibrahim Suliman<br/><br/>Abstract: The immune system is normally present in homeostaticcondition. Immunosuppression is accompanied by the increase ofsusceptibility to infection and/or cancer formation while, its overactivity is linked with hypersensitivity or autoimmunity. Psychic stressis known to induce immunosuppression but the mechanism is stillcontroversial and presents an area for scientific debates. It isbelieved that activation of the sympathetic nervous system or thehypothalamic pituitary-adrenal axis mechanisms are among theplayers in stress-induced immunosuppression but the literaturesindicate other factors. Direct oxidative stress in the immune cells andorgans is a suspect candidate but scientific evidence is needed toexplore its role. The present study aims to elucidate a possiblerelationship between oxidative stress and cold-immobilization (as amodel for psychic stress) induced-immunosuppression. Also toinvestigate the possible protective effect of melatonin and silymarin ,as tools, so as to help understanding the underlying mechanism ofpsychic stress-induced immunosuppression. The present work involvestwo experiments. First experiment correlate the oxidative stressparameters such as thymus gland and spleen contents of GSH, MDAand NO, to immune relevant parameters such as thymus and spleenrelative weights, lymphoproliferative response to PHA, Con-A and LPSas well as corticosterone as a marker for psychic stress. All as afunction of time of cold-immobilization in rats. The secondexperiment investigates the possible protective effect of melatoninand silymarin (100mg/kg once daily for 5 consecutive days beforestress) against psychic stress-induced immunosuppression. In additionto the previously mentioned parameters, macrophage function,apoptosis in splenocytes and host resistance to Listeriamonocytogenes and Streptococcus pneumonia are assessed. Results ofthe present work show that cold-immobilization stress revealed amarked direct oxidative stress in the thymus and spleen as indicatedby a marked decrease in GSH content accompanied by a markedelevation of MDA and NO contents. It also revealed a correspondingimmunosuppression as shown by a significant inhibition in T-and Bcellproliferation, a marked decrease in macrophage function,induction of apoptosis in splenocytes and a marked decrease in hostresistance to both Listeria monocytogenes and Streptococcuspneumonia. Both melatonin and silymarin revealed a significantpreventive effects of all previously mentioned parameters with onlydifference in B-cell function where protective effect of melatoninwas more obvious on T-cell rather than B-cell functions. Inconclusion, it seems that oxidative stress plays an important role as amechanism of acute psychic stress induced-immunosuppression thatcould be mitigated by the use of antioxidants. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/123456789/8591 Title: Modified proximal technique to decompose variational inequality problems<br/><br/>Authors: Al-Jadhei, Reem<br/><br/>Abstract: Our study was concerned by a development of an algorithm thatdecomposes the original variational inequality problem into aseries of low-dimensional sub-problems with nonlinearconstraints. Also, it is worth to mention that the difficulty here ishow can we deal with the nonlinearity of the constraints in ourvariational inequality model and in the same time how can weobtain a decomposition scheme where the convergenceis guaranteed under mild conditions. Our work has reached thefollowing points:1) Presenting the Variational Inequality Problems (VIP) to thereader with some theoretical results on existence, uniqueness ofsolutions and convergence of some classical approaches.Also, in chapter 2, a nonexhaustive summary about the link of.VIP's and other mathematical topics was given2) Presenting a recent algorithm to solve a large scale VIPdeveloped and studied by Yang and his associates (1999-2001).3) Developing a new algorithm based on auxiliary principlemixed with quadratic and non-quadratic proximal pointtechniques to solve a VIP with nonlinear constraints.<br/><br/>Description: Master of Science thesis Mon, 01 Aug 2005 00:00:00 GMT