Descemet’s stripping automated endothelial keratoplasty for congenital hereditary endothelial dystrophy

Congenital hereditary endothelial dystrophy (CHED), presents in infancy or early childhood with bilateral clouding of corneas. This condition has previously been managed surgically with penetrating keratoplasty (PKP). Performing PKP in pediatric patients has its own set of difficulties. More recently, there has been growing interest in treating this condition with Descemet’s stripping automated endothelial keratoplasty (DSAEK). The purpose of this study is to report our experience of successfully performing DSAEK in a child with CHED

Knowledge, attitudes and practices among people in Saudi Arabia regarding COVID-19: A cross-sectional study

Background: The general population’s compliance with preventive measures and legislation is mainly influenced by their knowledge level, attitude, and practices. This study assessed the knowledge, attitude, and practices of public residents towards corona virus disease-2019 preventive measures in Saudi Arabia. Design and Methods: This is a cross-sectional study; it used a validated cross-sectional online survey that received responses from 13 Saudi administrative regions. Results: There were 1513 participants who completed the study (55% females; 77.7%, university education). Knowledge level, attitude, and practices towards corona virus disease-2019 were 81.3%, 86.6%, and 81.9%, respectively. The knowledge subscales showed that 1496 (98.9%) participants knew the system targeted by the virus, 96.2% and 97.3% knew the causative agent and symptoms, 783 (52.2%) participants knew the transmission modes, and 696 (46.0%) participants knew about the complications. The attitude subscales included 1465 (96.5%) participants who had dealt with an infected person, 1451 (95.9%) participants who isolated in a health facility, 1195 (97.0%) participants who knew about hand washing, and 1387 (91.7%) participants who thought the virus spread through home delivery. The practice subscales included 1505 (99.5%) participants who properly disposed of gloves and tissues and 1347 (89.0%) participants who reported safe practices when coughing or sneezing.Conclusions: This study showed satisfactory knowledge, attitude, and practice towards corona virus disease-2019 in Saudi Arabia. The educational level is a dominant influencing factor for knowledge, attitude, and practice

A Proposed Educational Model to Improve the Operations of Knowledge-Exchange between MOE and Higher Education Institutions in Jordan

هدفت الدراسة إلى بناء أنموذج تربوي مقترح لتحسين عمليات تبادل المعرفة بين وزارة التّربية والتّعليم ومؤسسات التّعليم العالي في الأردنّ، وتكونت عينة الدراسة من (301) من القادة التربويين، منهم (158) عضو هيئة تدريس من العاملين في كلية العلوم التربوية بالجامعة الأردنية، وكلية التّربية بجامعة اليرموك، و(143) من العاملين في مركز وزارة التّربية والتّعليم في الأردنّ للعام الدراسي 2016/ 2017م. ولتحقيق هدف الدراسة قام الباحثان ببناء استبانة تكونت من (88) فقرة بعد التحقق من دلالات صدقها وثباتها، ولتحليل البيانات استُخدمت المتوسطات الحسابية، والانحرافات المعيارية. أظهرت نتائج الدراسة تقديرات متوسطة لدرجة ممارسة عمليات تبادل المعرفة بين وزارة التّربية والتّعليم ومؤسسات التّعليم العالي في الأردن من وجهة نظر القادة التربويين، وكذلك بينت النتائج أن درجة تقدير القادة التربويين للمعوقات التي توجه عمليات تبادل المعرفة كانت متوسطة، وتوصلت الدراسة إلى بناء أنموذج لتحسين عمليات تبادل المعرفة بين وزارة التّربية والتّعليم ومؤسسات التّعليم العالي في الأردن، والتي أوصت باعتماده وتطبيقه في الأردن وتقييمه بشكل مستمر. الكلمات المفتاحية: الأنموذج، عمليات تبادل المعرفة، درجة الممارسة، المعوقات، الجامعات الأردنية، وزارة التّربية والتّعليم الأردنية.The purpose of this study was to build a proposed educational model for improving knowledge-exchange processes between the Ministry of Education and Higher Education institutions in Jordan. The sample of the study consisted of (301) educational leaders: (158) academic staff members from the Faculty of Educational Sciences – University of Jordan – and the Faculty of Education in Yarmouk University; and (143) members from the center of Jordanian Ministry of Education for the academic year 2016/2017. To achieve the aims of the study, the researcher built a questionnaire, consisting of (88) items as tool for collecting data. The research tool was checked for its validity and reliability semantics. To analyze the data, means and standard deviation were used. The results of the study showed that the educational leaders rated the degree of practicing knowledge-exchange processes between Jordanian Ministry of Education and Higher Education institutions in Jordan as (moderate). Also, they rated the obstacles that face knowledge-exchange processes as (moderate). The study concluded with a proposed educational model for improving knowledge-exchange processes between the Ministry of Education and Higher Education institutions in Jordan, and recommended to be approved and applied in Jordan. Keywords: A Proposed educational model, Knowledge-exchange processes, Practicing degree, Obstacles, Jordanian Universities, Jordanian Ministry of Educatio

Yangian in the Twistor String

We study symmetries of the quantized open twistor string. In addition to global PSL(4|4) symmetry, we find non-local conserved currents. The associated non-local charges lead to Ward identities which show that these charges annihilate the string gluon tree amplitudes, and have the same form as symmetries of amplitudes in N=4 super conformal Yang Mills theory. We describe how states of the open twistor string form a realization of the PSL(4|4) Yangian superalgebra.Comment: 37 pages, 4 figure

Functional modelling of a novel mutation in <em>BBS5</em>

Background: Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy disorder with 18 known causative genes (BBS1-18). The primary clinical features are renal abnormalities, rod-cone dystrophy, post-axial polydactyly, learning difficulties, obesity and male hypogonadism.Results: We describe the clinical phenotype in three Saudi siblings in whom we have identified a novel mutation in exon 12 of BBS5 (c.966dupT; p.Ala323CysfsX57). This single nucleotide duplication creates a frame shift results in a predicted elongated peptide. Translation blocking Morpholino oligonucleotides were used to create zebrafish bbs5 morphants. Morphants displayed retinal layering defects, abnormal cardiac looping and dilated, cystic pronephric ducts with reduced cilia expression. Morphants also displayed significantly reduced dextran clearance via the pronephros compared to wildtype embryos, suggesting reduced renal function in morphants. The eye, kidney and heart defects reported in morphant zebrafish resemble the human phenotype of BBS5 mutations. The pathogenicity of the novel BBS5 mutation was determined. Mutant mRNA was unable to rescue pleiotropic phenotypes of bbs5 morphant zebrafish and in cell culture we demonstrate a mislocalisation of mutant BBS5 protein which fails to localise discretely with the basal body.Conclusions: We conclude that this novel BBS5 mutation has a deleterious function that accounts for the multisystem ciliopathy phenotype seen in affected human patients. \ua9 2014 Al-Hamed et al.; licensee BioMed Central Ltd

A slice of AdS_5 as the large N limit of Seiberg duality

A slice of AdS_5 is used to provide a 5D gravitational description of 4D strongly-coupled Seiberg dual gauge theories. An (electric) SU(N) gauge theory in the conformal window at large N is described by the 5D bulk, while its weakly coupled (magnetic) dual is confined to the IR brane. This framework can be used to construct an N = 1 MSSM on the IR brane, reminiscent of the original Randall-Sundrum model. In addition, we use our framework to study strongly-coupled scenarios of supersymmetry breaking mediated by gauge forces. This leads to a unified scenario that connects the extra-ordinary gauge mediation limit to the gaugino mediation limit in warped space.Comment: 47 Pages, axodraw4j.st

Treatment reduces the incidence of newly appearing multiple sclerosis lesions evolving into chronic active, slowly expanding lesions: A retrospective analysis

Background and purpose: Newly appearing lesions in multiple sclerosis (MS) may evolve into chronically active, slowly expanding lesions (SELs), leading to sustained disability progression. The aim of this study was to evaluate the incidence of newly appearing lesions developing into SELs, and their correlation to clinical evolution and treatment. // Methods: A retrospective analysis of a fingolimod trial in primary progressive MS (PPMS; INFORMS, NCT 00731692) was undertaken. Data were available from 324 patients with magnetic resonance imaging scans up to 3 years after screening. New lesions at year 1 were identified with convolutional neural networks, and SELs obtained through a deformation-based method. Clinical disability was assessed annually by Expanded Disability Status Scale (EDSS), Nine-Hole Peg Test, Timed 25-Foot Walk, and Paced Auditory Serial Addition Test. Linear, logistic, and mixed-effect models were used to assess the relationship between the Jacobian expansion in new lesions and SELs, disability scores, and treatment status. // Results: One hundred seventy patients had ≥1 new lesions at year 1 and had a higher lesion count at screening compared to patients with no new lesions (median = 27 vs. 22, p = 0.007). Among the new lesions (median = 2 per patient), 37% evolved into definite or possible SELs. Higher SEL volume and count were associated with EDSS worsening and confirmed disability progression. Treated patients had lower volume and count of definite SELs (β = −0.04, 95% confidence interval [CI] = −0.07 to −0.01, p = 0.015; β = −0.36, 95% CI = −0.67 to −0.06, p = 0.019, respectively). // Conclusions: Incident chronic active lesions are common in PPMS, and fingolimod treatment can reduce their number

Quantum control of hybrid nuclear-electronic qubits

Pulsed magnetic resonance is a wide-reaching technology allowing the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip either dilute electronic or nuclear spins is orders of magnitude shorter than their decoherence times, leading to several schemes for quantum information processing with spin qubits. We investigate instead the novel regime where the eigenstates approximate 50:50 superpositions of the electronic and nuclear spin states forming "hybrid nuclear-electronic" qubits. Here we demonstrate quantum control of these states for the first time, using bismuth-doped silicon, in just 32 ns: this is orders of magnitude faster than previous experiments where pure nuclear states were used. The coherence times of our states are five orders of magnitude longer, reaching 4 ms, and are limited by the naturally-occurring 29Si nuclear spin impurities. There is quantitative agreement between our experiments and no-free-parameter analytical theory for the resonance positions, as well as their relative intensities and relative Rabi oscillation frequencies. In experiments where the slow manipulation of some of the qubits is the rate limiting step, quantum computations would benefit from faster operation in the hybrid regime.Comment: 20 pages, 8 figures, new data and simulation

Results from PAMELA, ATIC and FERMI : Pulsars or Dark Matter ?

It is well known that the dark matter dominates the dynamics of galaxies and clusters of galaxies. Its constituents remain a mystery despite an assiduous search for them over the past three decades. Recent results from the satellite-based PAMELA experiment detect an excess in the positron fraction at energies between 10-100 GeV in the secondary cosmic ray spectrum. Other experiments namely ATIC, HESS and FERMI show an excess in the total electron (\ps + \el) spectrum for energies greater 100 GeV. These excesses in the positron fraction as well as the electron spectrum could arise in local astrophysical processes like pulsars, or can be attributed to the annihilation of the dark matter particles. The second possibility gives clues to the possible candidates for the dark matter in galaxies and other astrophysical systems. In this article, we give a report of these exciting developments.Comment: 27 Pages, extensively revised and significantly extended, to appear in Pramana as topical revie

Induced vertical disparity effects on local and global stereopsis

Purpose: Although significant amounts of vertical misalignment could have a noticeable effect on visual performance, there is no conclusive evidence about the effect of very small amount of vertical disparity on stereopsis and binocular vision. Hence, the aim of this study was to investigate the effects of induced vertical disparity on local and global stereopsis at near. Materials and Methods: Ninety participants wearing best-corrected refraction had local and global stereopsis tested with 0.5 and 1.0 prism diopter (Δ) vertical prism in front of their dominant and non-dominant eye in turn. This was compared to local and global stereopsis in the same subjects without vertical prism. Data were analyzed in SPSS.17 software using the independent samples T and the repeated measures ANOVA tests. Results: Induced vertical disparity decreases local and global stereopsis. This reduction is greater when vertical disparity is induced in front of the non-dominant eye and affects global more than local stereopsis. Repeated measures ANOVA showed differences in the mean stereopsis between the different measured states for local and global values. Local stereopsis thresholds were reduced by 10s of arc or less on average with 1.0Δ of induced vertical prism in front of either eye. However, global stereopsis thresholds were reduced by over 100s of arc by the same 1.0Δ of induced vertical prism. Conclusion: Induced vertical disparity affects global stereopsis thresholds by an order of magnitude (or a factor of 10) more than local stereopsis. Hence, using a test that measures global stereopsis such as the TNO is more sensitive to vertical misalignment than a test such as the Stereofly that measures local stereopsis. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted