From Local to Global and Informal to Formal: Entering Mainstream Markets

women, informal economy, cooperative, India, poverty, institutions

Early Prediction of ‘At-Risk’ Learners on Virtual Platforms using ODFs

This Learning analytics are one of the most important assistance tools used by educators for early identification of at-risk learners. Researchers have used many AI based tools for monitoring learning and improving learner’s performances by using any early intervention strategies to reduce dropout rates on online platforms that lacks face-to-face acknowledgement and feedback. Online platforms have Online Discussion Forums (ODFs) where a learner can post his queries and interact with other learners or the instructor. It becomes one of the useful indicators of tracking participation of a learner in the teaching learning process. Learners who actively participate in interaction on these online discussion platforms and contribute to the learning content required by other users are believed to give better performance as compared to those who do not participate in forum discussion. This paper focuses on the aspects of forum discussion like frequency of posts, sentimental analysis of forum post, number of threads initiated or replied to, and also how recent the post to predict the learners who could be at-risk of dropping out. The prediction model uses a data set from secondary resource. Various metrics like Confusion Matrix and Loss curve are employed to measure the accuracy of the model. Results indicate that data captured using forum posts can help in early identification of At-risk Learners

Aspheric intraocular lens in cataract surgery

This thesis, by prior publication, encompasses an overview and critical analysis of 6 publications on aspheric intraocular lenses (IOLs) carried out at St. Thomas’ Hospital, Guy’s & St. Thomas’ NHS Foundation Trust, London between 2006 2012. The focus is on two areas: the visual and optical performance of aspheric IOLs with different values of asphericity, and their effect on posterior capsule opacification (PCO). Chapter 1 describes the history of IOLs and the evolution of aspheric IOLs. It also presents relevant optical concepts. The three publications presented in Chapter 2 compare aspheric IOLs with spherical IOLs. The results come from two prospective, randomised, fellow-eye comparison studies: one comparing a spherical Alcon AcrySof SN60AT versus the aspheric Alcon AcrySof SN60WF (with negative asphericity), which partially corrects corneal spherical aberrations, and the other comparing the Zeiss AcriSmart 36A (with negative asphericity), which partially corrects corneal spherical aberrations, and the Bausch & Lomb Akreos MI60 (with neutral asphericity), which has zero spherical aberration. The third publication reports changes in vertical coma after implantation of all the above lenses and additionally includes data on two spherical IOLs from a previous study by our group (the three piece Alcon MA60AC IOL and the plate haptic HumanOptic MC611MI IOL). For this study, the data were divided according to their asphericity and not design. To avoid confounding from aberrometric differences due to astigmatism and surgical techniques, standard incision sizes of 2.75 mm and 2.4 mm were used in the two felloweye, randomised studies and a single surgeon performed all the surgeries using same incision size for each study. Results demonstrated that the aspheric IOLs significantly reduced spherical aberration, improved mesopic contrast sensitivity and reduced depth-of-focus. Asphericity differences up to 20 μm were not associated with depth-of-focus and the degree of asphericity was not associated with best-corrected distance visual acuity. The vertical coma varied within IOL groups of the same asphericity but there was no statistically significant difference between the two spherical IOLs (AcrySof SN60AT and AcrySof MA60AC). Further critical analysis of our data already published showed no statistically significant difference in mean vertical coma between the AcrySof MA60AC (-0.060 ± 0.211μm) with that of Akreos MI60 (- 0.042 ± 0.148μm) (p=0.70) and AcriSmart 36A (-0.034 ± 0.141μm) (p=0.58) even though the AcrySof MA60AC, Akreos MI60 and AcriSmart 36A IOLs had different asphericity. This may be due to the difference in the IOL designs, decentration and difference in the sample sizes between groups. Chapter 3 discusses the findings of three publications related to posterior capsule opacification (PCO). The first publication is an in vitro study assessing posterior optic square edges of various commercially available spherical and aspherical IOLs. Results demonstrated hydrophilic IOLs had less sharp square edges compared to hydrophobic IOLs. Although these in vitro results are potentially significant, there are currently no in vivo studies on the lenses used to compare our results with. The other two publications are based on the PCO outcomes from the prospective, randomised, fellow-eye studies described above. There was no difference in the PCO rates between hydrophobic spherical AcrySof SN60AT and aspheric AcrySof SN60WF IOLs of the same design at 2 years. In contrast, we found a significant increase in the PCO with both the hydrophilic acrylic AcriSmart 36A and Akreos MI60 IOLs (one with negative asphericity and one with neutral asphericity). Variation in asphericity did not appear to be an important factor contributing to the PCO but it was apparent that the edge design and material of the IOL were important with regards to the PCO formation. Finally, since these publications, some of manufacturers have changed their IOL models and today a majority of the IOLs have are aspheric and have a sharp edge profile. The overall, benefit of using aspheric IOLs seems to be limited as it is dependent on the natural pupil size

Trypanosoma brucei TIF2 and TRF Suppress VSG Switching Using Overlapping and Independent Mechanisms

Trypanosoma brucei causes debilitating human African trypanosomiasis and evades the host\u27s immune response by regularly switching its major surface antigen, VSG, which is expressed exclusively from subtelomeric loci. We previously showed that two interacting telomere proteins, TbTRF and TbTIF2, are essential for cell proliferation and suppress VSG switching by inhibiting DNA recombination events involving the whole active VSG expression site. We now find that TbTIF2 stabilizes TbTRF protein levels by inhibiting their degradation by the 26S proteasome, indicating that decreased TbTRF protein levels in TbTIF2-depleted cells contribute to more frequent VSG switching and eventual cell growth arrest. Surprisingly, although TbTIF2 depletion leads to more subtelomeric DNA double strand breaks (DSBs) that are both potent VSG switching inducers and detrimental to cell viability, TbTRF depletion does not increase the amount of DSBs inside subtelomeric VSG expression sites. Furthermore, expressing an ectopic allele of F2H-TbTRF in TbTIF2 RNAi cells allowed cells to maintain normal TbTRF protein levels for a longer frame of time. This resulted in a mildly better cell growth and partially suppressed the phenotype of increased VSG switching frequency but did not suppress the phenotype of more subtelomeric DSBs in TbTIF2-depleted cells. Therefore, TbTIF2 depletion has two parallel effects: decreased TbTRF protein levels and increased subtelomeric DSBs, both resulting in an acute increased VSG switching frequency and eventual cell growth arrest

Outcomes of Descemet's membrane endothelial keratoplasty performed in combination with, before, or after cataract surgery in Fuchs' endothelial dystrophy: A review of the literature and meta-analysis

This review aimed to compare the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) in combination with (category 1), before (category 2), or after cataract surgery (category 3) in patients with Fuchs' endothelial dystrophy (FED). Primary outcome was gain in best-corrected log of minimum angle of resolution (logMAR) visual acuity (BCVA). Secondary outcomes were graft detachment, rebubbling rates, rejection, failure, and endothelial cell loss (ECL). In category 1, 2, and 3, 12 studies (N = 1932) were included (five in category 1 [n = 696], one in category 2 [n = 286], and two in category 3 [n = 950], and the remaining four compared between two of the three categories). At 6 months, the gain in BCVA was 0.34 ± 0.04, 0.25 ± 0.03, and 0.38 ± 0.03 logMAR in category 1, 2, and 3, respectively. The difference was significant between categories 1 and 2 (Chi2 = 11.47, P < 0.01) and categories 2 and 3 (Chi2 = 35.53, P < 0.01). At 12 months, the gain in BCVA was 0.52 ± 0.05 and 0.38 ± 0.06 logMAR in categories 1 & 3 (Chi2 = 14.04, P < 0.01). The rebubbling rates were 15%, 4%, and 10% (P < 0.01) and the graft detachment rates were 31%, 8%, and 13% (P < 0.01) in categories 1, 2, and 3, respectively. However, graft rejection, survival rates, and ECL at 12 months were not different between categories 1 and 3. There is low certainty evidence that gain in BCVA in category 1 was comparable to category 3 at 6 months; however, it was significantly better with category 3 at 12 months. Although rebubbling and graft detachment rates were highest in category 1, there was no significant difference in graft rejection, survival rates, and ECL. Further high-quality studies are likely to change the effect estimate and have an impact on the confidence of the estimate

Trypanosoma brucei RAP1 Maintains Telomere and Subtelomere Integrity by Suppressing TERRA and Telomeric RNA: DNA Hybrids

Trypanosoma brucei causes human African trypanosomiasis and regularly switches its major surface antigen, VSG, thereby evading the host\u27s immune response. VSGs are monoallelically expressed from subtelomeric expression sites (ESs), and VSG switching exploits subtelomere plasticity. However, subtelomere integrity is essential for T. brucei viability. The telomeric transcript, TERRA, was detected in T. brucei previously. We now show that the active ES-adjacent telomere is transcribed. We find that TbRAP1, a telomere protein essential for VSG silencing, suppresses VSG gene conversionmediated switching. Importantly, TbRAP1 depletion increases the TERRA level, which appears to result from longer read-through into the telomere downstream of the active ES. Depletion of TbRAP1 also results in more telomeric RNA:DNA hybrids and more double strand breaks (DSBs) at telomeres and subtelomeres. In TbRAP1-depleted cells, expression of excessive TbRNaseH1, which cleaves the RNA strand of the RNA:DNA hybrid, brought telomeric RNA:DNA hybrids, telomeric/subtelomeric DSBs and VSG switching frequency back to WT levels. Therefore, TbRAP1-regulated appropriate levels of TERRA and telomeric RNA:DNA hybrid are fundamental to subtelomere/telomere integrity. Our study revealed for the first time an important role of a long, non-coding RNA in antigenic variation and demonstrated a link between telomeric silencing and subtelomere/telomere integrity through TbRAP1-regulated telomere transcription

Optical aberrations following implantation of multifocal intraocular lenses: a systematic review and meta-analysis protocol

INTRODUCTION: Multifocal intraocular lens (IOLs) are used to restore vision at different focal distances. The technology of multifocal IOLs is continually advancing. Optical aberrations a property of lenses that causes spreading of light over a region resulting in a blurred or distorted image. This study aims to systematically review investigator measured and patient reported optical aberrations following implantation of multifocal IOLs during phacoemulsification surgery to treat presbyopia in adults. METHODS AND ANALYSIS: We will conduct an electronic database search for randomised controlled trials, prospective non-randomised studies, observational studies in Ovid MEDLINE, Ovid EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Scopus and ClinicalTrials.gov in March 2021. Eligibility criteria will include quantitative articles written in English and containing data on optical aberrations. Two independent reviewers will screen titles and abstracts and extract data from full texts, reporting outcomes according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data extraction of key characteristics will be completed using customised forms. Methodological quality will be assessed using Cochrane Handbook 6.2. ETHICS AND DISSEMINATION: Ethics approval is not required for this review, as it will only include published data. Findings will be published in a peer-reviewed journal and disseminated across ophthalmic networks. We anticipate that the findings of this work will be of interest to multiple stakeholders: people who have undergone cataract surgery, eye health professionals, ophthalmic surgeons, device manufacturers and policy-makers. It will also inform researchers to where there are gaps in evidence and identify areas for future research. PROSPERO REGISTRATION NUMBER: CRD42021271050

Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT

BACKGROUND: Cataract surgery is one of the most common operations. Femtosecond laser-assisted cataract surgery (FLACS) is a technique that automates a number of operative steps. OBJECTIVES: To compare FLACS with phacoemulsification cataract surgery (PCS). DESIGN: Multicentre, outcome-masked, randomised controlled non-inferiority trial. SETTING: Three collaborating NHS hospitals. PARTICIPANTS: A total of 785 patients with age-related cataract in one or both eyes were randomised between May 2015 and September 2017. INTERVENTION: FLACS (n = 392 participants) or PCS (n = 393 participants). MAIN OUTCOME MEASURES: The primary outcome was uncorrected distance visual acuity in the study eye after 3 months, expressed as the logarithm of the minimum angle of resolution (logMAR): 0.00 logMAR (or 6/6 if expressed in Snellen) is normal (good visual acuity). Secondary outcomes included corrected distance visual acuity, refractive outcomes (within 0.5 dioptre and 1.0 dioptre of target), safety and patient-reported outcome measures at 3 and 12 months, and resource use. All trial follow-ups were performed by optometrists who were masked to the trial intervention. RESULTS: A total of 353 (90%) participants allocated to the FLACS arm and 317 (81%) participants allocated to the PCS arm attended follow-up at 3 months. The mean uncorrected distance visual acuity was similar in both treatment arms [0.13 logMAR, standard deviation 0.23 logMAR, for FLACS, vs. 0.14 logMAR, standard deviation 0.27 logMAR, for PCS, with a difference of -0.01 logMAR (95% confidence interval -0.05 to 0.03 logMAR; p = 0.63)]. The mean corrected distance visual acuity values were again similar in both treatment arms (-0.01 logMAR, standard deviation 0.19 logMAR FLACS vs. 0.01 logMAR, standard deviation 0.21 logMAR PCS; p = 0.34). There were two posterior capsule tears in the PCS arm. There were no significant differences between the treatment arms for any secondary outcome at 3 months. At 12 months, the mean uncorrected distance visual acuity was 0.14 logMAR (standard deviation 0.22 logMAR) for FLACS and 0.17 logMAR (standard deviation 0.25 logMAR) for PCS, with a difference between the treatment arms of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.17). The mean corrected distance visual acuity was 0.003 logMAR (standard deviation 0.18 logMAR) for FLACS and 0.03 logMAR (standard deviation 0.23 logMAR) for PCS, with a difference of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.11). There were no significant differences between the arms for any other outcomes, with the exception of the mean binocular corrected distance visual acuity with a difference of -0.02 logMAR (95% confidence interval -0.05 to 0.00 logMAR) (p = 0.036), which favoured FLACS. There were no significant differences between the arms for any health, social care or societal costs. For the economic evaluation, the mean cost difference was £167.62 per patient higher for FLACS (95% of iterations between -£14.12 and £341.67) than for PCS. The mean QALY difference (FLACS minus PCS) was 0.001 (95% of iterations between -0.011 and 0.015), which equates to an incremental cost-effectiveness ratio (cost difference divided by QALY difference) of £167,620. LIMITATIONS: Although the measurement of outcomes was carried out by optometrists who were masked to the treatment arm, the participants were not masked. CONCLUSIONS: The evidence suggests that FLACS is not inferior to PCS in terms of vision after 3 months' follow-up, and there were no significant differences in patient-reported health and safety outcomes after 12 months' follow-up. In addition, the statistically significant difference in binocular corrected distance visual acuity was not clinically significant. FLACS is not cost-effective. FUTURE WORK: To explore the possible differences in vision in patients without ocular co-pathology. TRIAL REGISTRATION: Current Controlled Trials ISRCTN77602616. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 6. See the NIHR Journals Library website for further project information. Moorfields Eye Charity (grant references GR000233 and GR000449 for the endothelial cell counter and femtosecond laser used)