Myopia progression in school children with prolonged screen time during the coronavirus disease confinement

Background: Myopia, the most common refractive error, is a global public health problem with substantial visual impairment if left untreated. Several studies have investigated the association between increased near-work and restricted outdoor activities in children with myopia; however, such studies in children without myopia are scarce. We aimed to monitor the effect of the coronavirus disease-2019 (COVID-19) home confinement and mandatory virtual learning on myopic progression among myopic and non-myopic school-aged children. Methods: We conducted a retrospective chart review of children aged 6 – 12 years attending regular visits to the pediatric ophthalmology clinic in a tertiary eye hospital in Eastern Province, Saudi Arabia. Cycloplegic refraction was determined from three visits at least six months apart: two visits before the start of the COVID-19 pandemic and one during the COVID-19 home confinement. Parents were asked about the time spent in near-work and outdoor activities, the devices used during virtual learning, and the demographic characteristics of the children. Statistical analyses were conducted to compare myopia progression before and during the COVID-19 home confinement. Results: A total of 160 eyes of 80 children were analyzed. The boy (n = 46) to girl (n = 34) ratio was 1.4:1. The hyperopia (n = 131 eyes) to myopia (n = 29 eyes) ratio was 4.5:1. Most eyes exhibited a hyperopic shift before the confinement; however, all eyes displayed a myopic shift during the confinement. When comparing both eyes of the same individual, the more myopic or less hyperopic eye in the same child had a significantly greater myopic shift than the fellow eye (both P < 0.05). Children who used tablets showed a significant myopic shift (P < 0.05). Likewise, children in both age categories (less than or equal to 8 and > 8 years), boys, those living in an apartment, and those having parents with bachelor’s degrees experienced a significant myopic shift during COVID-19 home confinement compared to before (all P < 0.05). The mean myopic shift was greater in children aged > 8 years than in those aged less than or equal to 8 years. Children with and without a family history of myopia had a myopic shift in the mean spherical equivalent during COVID-19 home confinement; however, that of children with no family history was statistically significant (P < 0.05). Conclusions: Progression of myopia accelerated in children during the COVID-19 pandemic. Excessive time spent on digital screen devices at near distances is considered a substantial environmental contributor to myopic shift in children. Further multicenter studies with extended follow-up periods are needed to assess the factors contributing to myopic progression in our population

A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction

The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function

Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications

PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications

Biallelic variants in PCDHGC4 cause a novel neurodevelopmental syndrome with progressive microcephaly, seizures, and joint anomalies.

PURPOSE: We aimed to define a novel autosomal recessive neurodevelopmental disorder, characterize its clinical features, and identify the underlying genetic cause for this condition. METHODS: We performed a detailed clinical characterization of 19 individuals from nine unrelated, consanguineous families with a neurodevelopmental disorder. We used genome/exome sequencing approaches, linkage and cosegregation analyses to identify disease-causing variants, and we performed three-dimensional molecular in silico analysis to predict causality of variants where applicable. RESULTS: In all affected individuals who presented with a neurodevelopmental syndrome with progressive microcephaly, seizures, and intellectual disability we identified biallelic disease-causing variants in Protocadherin-gamma-C4 (PCDHGC4). Five variants were predicted to induce premature protein truncation leading to a loss of PCDHGC4 function. The three detected missense variants were located in extracellular cadherin (EC) domains EC5 and EC6 of PCDHGC4, and in silico analysis of the affected residues showed that two of these substitutions were predicted to influence the Ca2+-binding affinity, which is essential for multimerization of the protein, whereas the third missense variant directly influenced the cis-dimerization interface of PCDHGC4. CONCLUSION: We show that biallelic variants in PCDHGC4 are causing a novel autosomal recessive neurodevelopmental disorder and link PCDHGC4 as a member of the clustered PCDH family to a Mendelian disorder in humans

Using Plastic Sand as a Construction Material toward a Circular Economy: A Review

Recently, research on innovative approaches to and practices for plastic waste management in a circular economy has gained momentum. Plastic waste pollution poses a serious environmental concern. At the same time, the cement industry is among the biggest sources of CO2 emissions, which poses another environmental challenge. This makes plastic sand bricks an attractive alternative to concrete blocks and bricks. This paper looks at the recent studies regarding the development of plastic sand bricks and the different percentages of plastic and sand used in the bricks. The literature review reveals that there is a lack of studies that evaluate plastic sand construction materials from an economic perspective. Such studies are essential if the industry is to invest in and adopt this alternative construction material. Plastic sand bricks could be a workable solution for combating issues related to solid waste. The compressive strength decreased with increasing ratios of plastic to sand. Plastic sand bricks weighed less than the conventional bricks. Issues requiring further investigation include: dealing with varying proportions and types of plastic, the lack of understanding of the long-term performance of plastic sand bricks, the flammability and fire resistance of plastic sand bricks, and the absence of appropriate standards and regulations for recycling plastic into plastic sand bricks. This paper allows us to look ahead in terms of some specific technical needs, the translation of the emerging technology into practice, and new ideas to decrease plastic pollution

Saudi Arabia’s Journey toward Net-Zero Emissions: Progress and Challenges

Combating climate change by reducing greenhouse gas (GHG) emissions has become an obligation for countries that ratified the Paris Agreement. Saudi Arabia, as a member of the Paris Agreement, pledged to achieve net zero emissions (NZE) by 2060. This endeavor is challenging for all countries. This paper provides an analysis and assessment of the Saudi measures to achieve NZE by 2060. The analysis reveals that Saudi Arabia will reduce the total net emissions to 49.67 Mt of CO2eq, whereas under a business-as-usual scenario, the emissions would reach 1.724 million tons (Mt) of CO2 equivalent (CO2eq). The study reveals that sectors conducting environmental, social, and governance ratings (ESG) and those where the government is a stakeholder are on the right track and will facilitate the government’s efforts in reaching NZE. The gap in reaching NZE will be mainly due to the Saudi steel and cement industries

Multi-functional double mode inverter for power quality enhancement in smart-grid applications

This paper introduces a new multi-functional double mode inverter (MFDMI) scheme, which is able to operate under a variety of operational conditions for aggregation of PV-based renewable energy resources. Detecting islanded situation within a new and fast approach, regulating the voltage in the islanded mode, smooth transition between islanded and grid-tied (GT) modes, injecting both active and reactive powers to the grid in addition to compensating the harmonics from nonlinear loads are beyond the most notable functionalities of the proposed framework. Technically, we exploit a combinational control scheme formed by instantaneous power theory, vector-control and a proportional integral resonant (PIR) controller to address the required functionalities. To deal with the low output power issue, photovoltaic (PV) cells are aggregated through a high gain DC-DC floating interleaved boost converter (FIBC). Moreover, a battery back-up module with bidirectional DC-DC floating interleaved buck-boost converter (FIBBC) is used to improve the system reliability and dispatch ability. The effectiveness of the proposed framework has been first verified within a comprehensive PSIM simulation results and then has been examined under realistic situations using the real-time simulator OPAL-RT with DSP modules (hardware in the loop) for a broad range of conditions and within different practical scenarios