An exploration of the gendering mediating students' attitudes and experiences in the formal academic curriculum at secondary school level in Libya

Introduction: The study was conducted to explore the gendering mediating students’attitudes and experiences towards the formal academic curriculum at secondary school level in Libya.The problematic nature of the link between access, quality of schooling and gender equality inthe curriculum in Libya is not sufficiently recognised. Methods: A total of 800 secondary students (ages 15-20), (males=389, females=411), who were from urban (n=360=45%) and rural (n=440=55%) localities of Libya completed a questionnaire designed to respond to a 5-point Likert scale of 19 items to elicit and to find out the key factors that influence students’ gendered perceptions, interests and characteristics of their future subject directions towards the aspects of school academic curriculum. 16 semi-structured interviews were also followed up to gain a deep understanding of the issues and enrich the validity of the questionnaire evidence. The statistical analysis software Statistical Package for Social Sciences (SPSS) was applied. The t-test statistic was used to compare the means and test the significance of any possible differences that existed between male and female responses

Multistage compression and transient flow in CO₂ pipelines with line packing

The main purpose of this thesis is to develop rigorous analytical and CFD models followed by their applications to real case studies in order to: i) identify the optimum multistage compression strategies for minimising the compression and intercooler power requirements for real CO2 feed streams containing various types and amounts of impurities associated with the various types of CO2 capture technologies; and ii) investigate the buffering efficacy of realistic CO2 transmission pipelines as a line packing strategy for smoothing out temporal fluctuations in feed loading and maintaining the desired dense-phase flow for both pure CO2 and its various realistic mixtures representative of the most common types of capture technologies. An analytical model based on thermodynamics principles is developed employing Plato Silverfrost FTN95 software and applied to determine the power requirements for various compression strategies and inter-stage cooling duties for typical pre-combustion (98.07 % v/v of CO2) and oxy-fuel CO2 mixtures of 85 and 96.7 % v/v CO2 purity compressed from a gaseous state at 15 bar and 38 oC to the dense-phase fluid at 151 bar. Compression options examined include conventional multistage integrally geared centrifugal compressors, advanced supersonic shockwave compressors and multistage compression combined with subcritical and supercritical liquefaction and pumping. In each case, the compression power requirement is calculated numerically using a 15-point Gauss-Kronrod quadrature rule in QUADPACK library, and employing the Peng-Robinson Equation of State (PR EOS) implemented in REFPROP v.9.1 to predict the pertinent thermodynamic properties of the CO2 and its mixtures. In the case of determining the power demand for inter-stage cooling and liquefaction, a thermodynamic model based on Carnot refrigeration cycle is applied. The study shows that a decrease in the impurity content from 15 to 1.9 % v/v in the CO2 streams reduces the total compression power requirement by ca. 1.5 % to as much as 30 %, while for all cases, inter-stage cooling duty is predicted to be significantly higher than the compression power demand. It is found that multistage compression combined with subcritical liquefaction using utility streams and subsequent pumping can offer a higher efficiency than conventional integrally geared centrifugal compression for high purity (> 96.7 % v/v) CO2 streams. In the case of a raw/dehumidified oxy-fuel mixture, that carries a relatively large amount of impurities (85 % v/v CO2), subcritical liquefaction at 62.53 bar is shown to increase the cooling duty by as much 50 % as compared to that for pure CO2. The second part of this study focuses on the development and testing of a numerical CFD model employing Plato Silverfrost FTN95 software for simulating the transient fluid flow behaviour in CO2 pipelines with line packing. The model is based on the numerical solution of the conservation equations using the Method of Characteristics, incorporating PR EOS to deal with CO2 and its various mixtures. Following its verification, the numerical model is employed to conduct a systematic study on the impact of operational flexibility involving a temporal reduction in the upstream CO2 feed flow rate on the transient flow behaviour in the pipe over a period of 8 hours. A particular focus of attention is determining the optimum pipeline design and operating line packing conditions required in order to maximise the delay in the transition from dense phase flow to the highly undesirable two-phase flow following the ramping down of the CO2 feed flow rate. The investigations were conducted for both pure CO2 and its various realistic mixtures. For the case studies examined, the results show that the efficacy of line packing can be increased by increasing the pipeline length from 50 to 150 km for the same pipe inner diameter of 437 mm. However, as the pipelines length increased to 150 km, the increase in the pipe inner diameter beyond 486 mm was found to have no further impact on the line drafting time. While, in the case of inlet feed temperature, the line drafting time increases following an increase in the inlet feed temperature of transported fluid from 283.15 K up to 303.15 K. Beyond the operating inlet feed temperature of 311.15 K, the line drafting time only marginally increased. It is also shown that the presence of impurities reduces the transition time to two-phase flow following the ramping down of the feed flow rate

Glaucoma Drainage Device Tube Retraction and Blockage in a Patient with Iridocorneal Endothelial Syndrome Treated With Nd:YAG Membranectomy

Purpose: To report on a case that demonstrates the successful treatment of tube blockage of the Ahmed Glaucoma Valve at its aqueous entry site by Nd:YAG laser membranectomy. Method: We report a case of refractory intraocular pressure elevation in a patient with iridocorneal endothelial syndrome after glaucoma drainage device due to blocked tube from the iridocorneal endothelial syndrome membrane. In July 2014, our patient presented with sudden right eye elevated intraocular pressure to 67 mmHg despite a well-controlled intraocular pressure in the range of teens with timolol alone over the last 2 years. Gonioscopy showed total synechial angle closure and increasing her medical treatment failed to control the intraocular pressure. Ahmed glaucoma valve was implanted successfully. However, recurrence of raised intraocular pressure from partial tube retraction and tube blockage at its aqueous entry site by an endothelial membrane was noted at 2 weeks after the surgery. Nd:YAG laser membranectomy was performed on 2 occasions to restore the patency of the tube shunt. After the second laser membranectomy, the patient’s intraocular pressure returned to, and remained at, normal level since. Conclusion: Tube occlusion by membrane is a well-known complication following glaucoma drainage device tube in patients with iridocorneal endothelial syndrome. Nd:YAG membranectomy is effective to restore the patency of tube lumen without subjecting patients to more invasive surgical interventions including tube extender or another glaucoma drainage device. However, more studies are required to ascertain the long term effect of laser membranectomy to a blocked tube, in comparison to other treatment modalities. To our knowledge, this is the first reported case of using laser membranectomy alone in treating Ahmed glaucoma valve tube obstruction due to a retracted tube blocked by endothelial membrane.published_or_final_versio

Intraocular Pressure Elevation in the Contralateral Untreated Eye Following Selective Laser Trabeculoplasty in Rabbit Eyes

Our study aimed at evaluating if a single session of unilateral selective laser trabeculoplasty would affect the intraocular pressure of the fellow untreated eye in rabbits. Eleven rabbits were involved. 360° selective laser trabeculoplasty with 532 nm frequency-doubled green Nd:YAG laser was performed over the right eyes. The mean intraocular pressure of both eyes at baseline, 3 hours, 24 hours, 3 days and 7 days after laser were measured. The baseline mean intraocular pressure of the right eye and the left eye were 8.07 ± 1.72 mmHg and 8.27 ± 1.56 mmHg respectively (p=0.78). The mean intraocular pressure of the treated eye was lower than the baseline from 3 hours through 3 days after laser, with a maximum mean decrease of 1.36 mmHg on Day 3. On the contrary, the mean intraocular pressures of the untreated eyes were higher than the baseline throughout the study, particularly at later course (1.91 mmHg on Day 3 and 1.85 mmHg on Day 7). This suggests the change of intraocular pressure in one eye after selective laser trabeculoplasty, leads to a change in the pressure of the fellow eye. It is thought that a neuronal and humoral response is triggered centrally after unilateral intraocular pressure change. The detailed mechanisms would require further studies to evaluate. The rising intraocular pressure trend in the contralateral untreated eye suggests that response may continue to exert its action for some time after the initial laser. This is the first reported study of intraocular pressure elevation of the untreated eye following contralateral selective laser trabeculoplasty.published_or_final_versio

Recurrent acute angle-closure attack due to plateau iris syndrome after cataract extraction with or without argon laser peripheral iridoplasty: a case report

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Consensual ophthalmotonic reaction in Chinese patients following augmented trabeculectomy or ExPRESS shunt implantation

INTRODUCTION: Consensual ophthalmotonic reaction (COR) was first described in 1924. Studies following monocular application of glaucoma drops and laser trabeculoplasty showed a drop in fellow eye intraocular pressure (IOP). However, studies following monocular surgery showed heterogeneous results. The purpose of this study was to investigate the COR in Chinese patients who have received monocular filtration surgery. METHODS: A noncomparative retrospective study of 65 eyes undergoing filtration surgery in Queen Mary Hospital was conducted. The IOP was obtained at baseline and postoperative days 1, 3, 7 and 14. Patient's age, sex, type of glaucoma and surgery, preoperative medications, postoperative bleb status, and number of interventions were tabulated. The postoperative IOP measurements over both eyes were obtained, and the readings were averaged to decrease the chances of extreme readings being a one-off event and allow for regression to the mean bias. RESULTS: COR was observed in the unoperated fellow eye. The mean preoperative IOP and averaged postoperative IOP were 17.2 +/- 5.2 mm Hg and 20.1 +/- 8.9 mm Hg, respectively (P 30% from baseline, while none showed IOP drop >30% from baseline. DISCUSSION: Following monocular penetrating filtration surgery, our Chinese population demonstrated a significant fellow eye IOP increase in the early postoperative period. We should bear in mind the influence of COR and take care to measure the fellow eye IOP following monocular surgery.published_or_final_versio

Suprachoroidal Hemorrhage with Delayed Rebleeding as the First Presentation of Bullous Pemphigoid Associated Acquired Hemophilia

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Choroidal effusion following post-trabeculectomy bleb massage- Case report

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Highly prevalent hyperuricaemia is associated with adverse clinical outcomes among Ghanaian stroke patients: An observational prospective study

Background: Although a direct causal relationship between hyperuricaemia and stroke continues to be debated, strong associations between serum uric acid (SUA) and cerebrovascular disease exist. Very few studies have been conducted to evaluate the frequency and association between this potentially modifiable biomarker of vascular risk and stroke in sub-Saharan Africa. Therefore the aim of this study was to examine the association between hyperuricaemia and the traditional risk factors and the outcomes of stroke in Ghanaian patients.Methods: In this prospective observational study, 147 patients presenting with stroke at a tertiary referral centre in Ghana were consecutively recruited. Patients were screened for vascular risk factors and SUA concentrations measured after an overnight fast. Associations between hyperuricaemia and stroke outcomes were analysed using Kaplan-Meier and Cox proportional hazards regression analysis.Results: The frequency of hyperuricaemia among Ghanaian stroke patients was 46.3%. Non-significant associations were observed between hyperuricaemia and the traditional risk factors of stroke. SUA concentration was positively correlated with stroke severity and associated with early mortality after an acute stroke with unadjusted hazards ratio of 2.3 (1.4 - 4.2, p=0.001). A potent and independent dose-response association between increasing SUA concentration and hazard of mortality was found on Cox proportional hazards regression, aHR (95% CI) of 1.65 (1.14-2.39), p=0.009 for each 100μmol/l increase in SUA.Conclusions: Hyperuricaemia is highly frequent and associated with adverse functional outcomes among Ghanaian stroke patients. Further studies are warranted to determine whether reducing SUA levels after a stroke would be beneficial within our setting.Key words: Hyperuricaemia, stroke, mortality, Ghan