A state-of-the-art review of the recent advances in exosome isolation and detection methods in viral infection.

Proteins, RNA, DNA, lipids, and carbohydrates are only some of the molecular components found in exosomes released by tumor cells. They play an essential role in healthy and diseased cells as messengers of short- and long-distance intercellular communication. However, since exosomes are released by every kind of cell and may be found in blood and other bodily fluids, they may one day serve as biomarkers for a wide range of disorders. In many pathological conditions, including cancer, inflammation, and infection, they play a role. It has been shown that the biogenesis of exosomes is analogous to that of viruses and that the exosomal cargo plays an essential role in the propagation, dissemination, and infection of several viruses. Bidirectional modulation of the immune response is achieved by the ability of exosomes associated with viruses to facilitate immunological escape and stimulate the body's antiviral immune response. Recently, exosomes have received a lot of interest due to their potential therapeutic use as biomarkers for viral infections such as human immunodeficiency virus (HIV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Epstein-Barr virus (EBV), and SARS-CoV-2. This article discusses the purification procedures and detection techniques for exosomes and examines the research on exosomes as a biomarker of viral infection.

The impact of nicotine smoking on spondyloarthritis and rheumatoid arthritis.

OBJECTIVE: Nicotine has major side effects on human health through numerous mechanisms, one of which is the alteration of the immune system and its genetic components. Such alteration can be a predisposing factor for autoimmune diseases such as spondyloarthritis (SpA) and rheumatoid arthritis (RA). This review aims to shed light on the effects of nicotine smoking on the pathophysiology, clinical presentation, and management of SpA and RA. METHODS: This review looked into the studies, excluding case reports and series, which were cited by PubMed/MEDLINE. RESULTS: Patients with established autoimmune conditions may have a different underlying pathophysiology and disease course when exposed to nicotine through cigarette smoking. Through the involvement of several cytokines, endothelial dysfunction, and epigenetic mechanisms, the severity of SpA is more prominent in smokers. The global health status, pain, and fatigue are worse in SpA patients. The evidence on the effect of nicotine smoking on the treatment of SpA is still limited. Nicotine can contribute to RA via the disruption of cellular regulatory activity, inflammatory responses, morphological, physiological, biochemical, and enzymatic responses. As such, smokers with RA have higher disease activity and are more likely to be seropositive through the citrullination of peptides. In addition, these patients are at risk of achieving a suboptimal response to tumor necrosis factor inhibitors. CONCLUSIONS: Cigarette smoking can substantially affect the pathophysiology and clinical presentation of patients with SpA and RA. The impact of nicotine on the management of these diseases still needs to be further studied.

BRCA1-specific machine learning model predicts variant pathogenicity with high accuracy.

Identification of novel BRCA1 variants outpaces their clinical annotation which highlights the importance of developing accurate computational methods for risk assessment. Therefore our aim was to develop a BRCA1-specific machine learning model to predict the pathogenicity of all types of BRCA1 variants and to apply this model and our previous BRCA2-specific model to assess BRCA variants of uncertain significance (VUS) among Qatari patients with breast cancer. We developed an XGBoost model that utilizes variant information such as position frequency and consequence as well as prediction scores from numerous in silico tools. We trained and tested the model with BRCA1 variants that were reviewed and classified by the Evidence-Based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium. In addition we tested the model's performance on an independent set of missense variants of uncertain significance with experimentally determined functional scores. The model performed excellently in predicting the pathogenicity of ENIGMA-classified variants (accuracy: 99.9%) and in predicting the functional consequence of the independent set of missense variants (accuracy: 93.4%). Moreover it predicted 2 115 potentially pathogenic variants among the 31 058 unreviewed BRCA1 variants in the BRCA exchange database. Using two BRCA-specific models we did not identify any pathogenic BRCA1 variants among those found in patients in Qatar but predicted four potentially pathogenic BRCA2 variants, which could be prioritized for functional validation.

Tactics of the tobacco industry in an Arab nation: a review of tobacco documents in Oman.

BACKGROUND: Few studies have investigated tobacco industry interference in the tobacco control policies of Arab nations. This paper explores the tactics used by the industry to subvert tobacco control policies in Oman and offers lessons on how to prevent such interference in the future. METHODS: We searched the Truth Tobacco Industry Documents Archive using the word 'Oman', names of government institutions, policymakers and local tobacco distributors. Extracted data were noted chronologically by key elements of tobacco control measures. Gulf Cooperation Council (GCC) Health Ministers' Council resolutions on tobacco control were also reviewed. RESULTS: Out of 1020 tobacco documents located, 327 were closely related to policy interference. Documents revealed that the industry met key government officials, offered in-kind services, used local diplomatic missions to influence Omani policymakers, opposed smoking bans, delayed regulations to lower tar and nicotine content of cigarettes, and to require effective health warnings, circumvented a tobacco advertising, promotion and sponsorship ban and provided voluntary codes as an alternative to effective regulations. Additionally, industry representatives lobbied individual countries in the GCC to veto tax increments and defeat consensus on agreed resolutions of the Health Ministers' Council. CONCLUSION: The tobacco industry interfered in all key public health policies aimed to reduce tobacco use in Oman. There is an urgent need for the Omani government to enforce the Civil Code of Conduct and develop guidelines for all policymakers through implementing Article 5.3 of the WHO Framework Convention on Tobacco Control to curb the tobacco epidemic.

Entangled-Based Quantum Wavelength-Division-Multiplexing and Multiple-Access Networks.

This paper investigates the mathematical model of the quantum wavelength-division-multiplexing (WDM) network based on the entanglement distribution with the least required wavelengths and passive devices. By adequately utilizing wavelength multiplexers, demultiplexers, and star couplers, N wavelengths are enough to distribute the entanglement among each pair of N users. Moreover, the number of devices employed is reduced by substituting a waveguide grating router for multiplexers and demultiplexers. Furthermore, this study examines implementing the BBM92 quantum key distribution in an entangled-based quantum WDM network. The proposed scheme in this paper may be applied to potential applications such as teleportation in entangled-based quantum WDM networks.

Home infusion services in Saudi Arabia: Where are we standing?

Diseases management has reached the highest level of complexity and cost in history, worldwide, and in Saudi Arabia in particular, which led to prolonged, unnecessary hospital stays. There have been many recent innovative measures to reduce these issues. One is to provide home infusion services. Hence, this narrative review emphasizes the expected benefits and challenges of such services and the applicability of their implementation in Saudi Arabia. A literature search was conducted via PubMed database, involving all published studies from inception until March 24th, 2023. Many studies showed positive impacts of home infusion on reducing the length of hospital stays, increasing cost-saving, and leading to high patient satisfaction.

Validation of the Arabic Version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale.

BACKGROUND: The Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) has become the gold standard for evaluating different domains in Parkinson's disease (PD), and it is commonly used in clinical practice, research, and clinical trials. OBJECTIVES: The objectives are to validate the Arabic-translated version of the MDS-UPDRS and to assess its factor structure compared with the English version. METHODS: The study was carried out in three phases: first, the English version of the MDS-UPDRS was translated into Arabic and subsequently back-translated into English by independent translation team; second, cognitive pretesting of selected items was performed; third, the Arabic version was tested in over 400 native Arabic-speaking PD patients. The psychometric properties of the translated version were analyzed using confirmatory factor analysis (CFA) as well as exploratory factor analysis (EFA). RESULTS: The factor structure of the Arabic version was consistent with that of the English version based on the high CFIs for all four parts of the MDS-UPDRS in the CFA (CFI ≥0.90), confirming its suitability for use in Arabic. CONCLUSIONS: The Arabic version of the MDS-UPDRS has good construct validity in Arabic-speaking patients with PD and has been thereby designated as an official MDS-UPDRS version. The data collection methodology among Arabic-speaking countries across two continents of Asia and Africa provides a roadmap for validating additional MDS rating scale initiatives and is strong evidence that underserved regions can be energically mobilized to promote efforts that apply to better clinical care, education, and research for PD. © 2022 International Parkinson and Movement Disorder Society.

The introduction of tobacco excise taxation in the Gulf Cooperation Council Countries: a step in the right direction of advancing public health.

BACKGROUND: The Gulf Cooperation Council (GCC) countries relied, until recently, solely on import duties for tobacco products. The agreement for the introduction of an excise and value added tax (VAT) in 2016 and 2017, respectively, in most GCC countries, was a major breakthrough for public health. There is, however, ample room for improvement. METHODS: The study examines the outcomes of tax reforms, for both public health and public finances, based on the World Health Organization (WHO) recommendations and best practices worldwide. Tax simulations were performed using the WHO TaXSiM model. The study is based on data from Saudi Arabia, the only GCC country for which sufficient data existed. RESULTS: We recommend a stepwise tax reform, which involves increasing the current ad valorem excise tax rate, phasing out import duties keeping total tax share constant and introducing a minimum excise, and finally switching to a revenue-neutral specific excise. Specific excises must be adjusted for inflation and income increases. If implemented, cigarette tax reform simulations show that the recommended reforms would lead to a higher than 50% increase in cigarette prices, 16% reduction in cigarette sales and almost 50% increase in total cigarette tax revenue. A significant number of cigarette-related deaths would be averted. CONCLUSIONS: The recommended tax reforms are expected to lead to significant improvements in both public health and tobacco tax revenues. Our results provide useful insights that are of relevance to the whole GGC region. The effectiveness of the reforms, however, requires a strong tax and customs administration, including the establishment of a good database to monitor and advance public health.

Harnessing landfill gas (LFG) for electricity: A strategy to mitigate greenhouse gas (GHG) emissions in Jakarta (Indonesia).

Due to its increasing demands for fossil fuels, Indonesia needs an alternative energy to diversify its energy supply. Landfill gas (LFG), which key component is methane (CH4), has become one of the most attractive options to sustain its continued economic development. This exploratory study seeks to demonstrate the added value of landfilled municipal solid waste (MSW) in generating sustainable energy, resulting from CH4 emissions in the Bantargebang landfill (Jakarta). The power generation capacity of a waste-to-energy (WTE) plant based on a mathematical modeling was investigated. This article critically evaluated the production of electricity and potential income from its sale in the market. The project's environmental impact assessment and its socio-economic and environmental benefits in terms of quantitative and qualitative aspects were discussed. It was found that the emitted CH4 from the landfill could be reduced by 25,000 Mt annually, while its electricity generation could reach one million kW â‹…h annually, savings on equivalent electricity charge worth US$ 112 million/year (based on US' 8/kW ⋅ h). An equivalent CO2 mitigation of 3.4 × 106 Mt/year was obtained. The income from its power sale were US$ 1.2 ×106 in the 1st year and 7.7 ×107US$ in the 15th year, respectively, based on the projected CH4 and power generation. The modeling study on the Bantargebang landfill using the LFG extraction data indicated that the LFG production ranged from 0.05 to 0.40 m3 per kg of the landfilled MSW. The LFG could generate electricity as low as US' 8 per kW ⋅ h. With respect to the implications of this study, the revenue not only defrays the cost of landfill's operations and maintenance (O&M), but also provides an incentive and means to further improve its design and operations. Overall, this work not only leads to a diversification of primary energy, but also improves environmental protection and the living standard of the people surrounding the plant.

Rheumatology research output in the Arab World: despite the challenges.

Rheumatology is a field in which diagnostic, pathophysiological, and therapeutic advancements occur daily. These developments are the result of research in basic sciences, translational sciences, and clinical sciences. Physical and financial support, provided by individuals and institutions, is essential for all types of research. The political and economic instability in the Arab world has impacted the advancement of healthcare and the output of research. This review seeks to evaluate the quantity and quality of rheumatology-related research conducted in the Arab world. This review examined the number of rheumatological clinical publications produced by Arab countries between 2017 and 2021 and cited by PubMed/MEDLINE. Publications with authors from multiple nations were disqualified. Publications were then categorized by type, including randomized controlled trials (RCTs), cohort studies, cross-sectional studies, systematic reviews, narrative reviews, and case reports. Publications were also organized according to the regions of the Arab world: North and East Africa, the Middle East, and the Arabian Peninsula. The review also used data from the world bank to evaluate the gross domestic product (GDP) and total population of Arabian nations in order to calculate a ratio of publications to GDP and publications to population. Egypt had the highest number of publications among north and east African countries and Arab countries in general, with 261 publications, including the highest number of RCTs, which were 23. With 81 publications, Saudi Arabia had the highest number of publications on the Arabian peninsula. However, no individual country on the Arabian peninsula published an RCT. Lebanon had the most publications in the Middle East, but the majority were reviews and case reports. Tunisia had the highest ratio of publications to GDP. Notably, the number of publications increased during the coronavirus disease 2019 era in some countries. The Arab world is still able to produce clinical rheumatology publications despite its political instability and lack of resources. The influence of such publications on the daily practice of rheumatology is still debatable.

Phase-only femtosecond optical pulse shaping based on an all-dielectric polarization-insensitive metasurface.

Recently, metasurfaces capable of manipulating the amplitude and the phase of an incident wave in a broad frequency band have been employed for femtosecond optical pulse shaping purposes. In this study, we introduce a phase-only pulse shaper based on an all-dielectric CMOS-compatible polarization-insensitive metasurface, composed of Si nano cylinders sitting on a fused silica substrate. The required phase profile of the metasurface for desired waveforms are calculated using an iterative Fourier transform algorithm, and the performance of the pulse shaper metasurface in implementing the phase masks was assessed using full-wave simulations. Such approach for realizing a polarization-insensitive metasurface-based phase-only pulse shaper has never been investigated to the best of our knowledge. It is demonstrated that the simulated results of the proposed metasurface-based pulse shaper is in great agreement with the results of the algorithm, while exhibiting a very high transmission efficiency. This work indicates yet another exciting but not fully examined application of meta-structures that is the optical pulse shaping.

Myocardial Injury After Colorectal Cancer Surgery and Postoperative 90-Day Mortality and Morbidity: A Retrospective Cohort Study.

BACKGROUND: Myocardial injury after noncardiac surgery is a strong predictor of 30-day mortality and morbidity. OBJECTIVE: The purpose of this study was to examine the incidence of myocardial injury in patients undergoing colorectal cancer surgery in an enhanced recovery after surgery protocol and its association with 90-day mortality and morbidity. DESIGN: This is a retrospective cohort study. SETTING: This study was conducted at Zealand University Hospital, Denmark, between June 2015 and July 2017. PATIENTS: Adult patients undergoing colorectal cancer surgery were included if troponin was measured at least twice during the first 7 days after surgery. The patients were followed for 90 days. MAIN OUTCOME MEASURES: Myocardial injury was defined as an elevated troponin I measurement (>45 ng/L) without evidence of a nonischemic origin causing the elevation. Ninety-day mortality and complications were assessed. RESULTS: A total of 586 patients were included of which 42 were diagnosed with myocardial injury. Thirteen patients (2%) died within 90 days of surgery. There was no significant difference in 90-day mortality between patients with and without myocardial injury (5% (2/42) versus 2% (11/544); p = 0.24). We found a higher incidence of postoperative complications within 90 days of surgery in the myocardial injury group than in the nonmyocardial injury group (43% (18/42) versus 20% (107/544); p < 0.01). We found a significant difference between the myocardial injury group and nonmyocardial injury group in terms of medical complications (33% (14/42) versus 9% (50/544); p < 0.01) but not surgical complications (19% (8/42) versus 16% (85/544); p = 0.56). Myocardial injury was an independent predictor of postoperative complications within 90 days of surgery (adjusted OR, 2.69; 95% CI, 1.31-5.55). LIMITATIONS: This study was limited by its retrospective design. CONCLUSION: Myocardial injury occurs frequently in patients undergoing colorectal cancer surgery in an enhanced recovery after surgery protocol. Patients with myocardial injury did not have a significantly higher 90-day mortality but had higher risk of 90-day postoperative complications than patients without myocardial injury. Future research should examine the prevention and treatment of myocardial injury. See Video Abstract at http://links.lww.com/DCR/B692. LESIN MIOCRDICA DESPUS DE LA CIRUGA DE CNCER COLORRECTAL Y MORTALIDAD Y MORBILIDAD POSOPERATORIAS A LOS DAS UN ESTUDIO DE COHORTE RETROSPECTIVE: ANTECEDENTES:La lesión del miocardio después de una cirugía no cardíaca es un fuerte predictor de mortalidad y morbilidad a los 30 días.OBJETIVO:El propósito fue examinar la incidencia de lesión miocárdica en pacientes sometidos a cirugía de cáncer colorrectal en un protocolo de recuperación mejorada después de la cirugía y su asociación con la mortalidad y morbilidad a los 90 días.DISEÑO:Estudio de cohorte retrospectivo.AJUSTE:Realizado en el Hospital Universitario de Zelanda, Dinamarca, entre junio de 2015 y julio de 2017.PACIENTES:Se incluyeron pacientes adultos sometidos a cirugía de cáncer colorrectal, si la troponina se midió al menos dos veces durante los primeros siete días después de la cirugía. Los pacientes fueron seguidos durante 90 días.PRINCIPALES MEDIDAS DE RESULTADO:La lesión miocárdica se definió como una medición de troponina I elevada (> 45 ng / l) sin evidencia de una etiología no isquémica que causara la elevación. Se evaluaron la mortalidad y las complicaciones a los noventa días.RESULTADOS:Se incluyeron un total de 586 pacientes, de los cuales 42 fueron diagnosticados de lesión miocárdica. Trece pacientes (2%) murieron dentro de los 90 días posteriores a la cirugía. No hubo diferencias significativas en la mortalidad a 90 días entre los pacientes con y sin lesión del miocardio, 5% [2/42] versus 2% [11/544], p = 0,24. Encontramos una mayor incidencia de complicaciones posoperatorias dentro de los 90 días de la cirugía en el grupo de lesión miocárdica en comparación con el grupo de lesión no miocárdica, 43% [18/42] versus 20% [107/544], p <0,01. Encontramos una diferencia significativa entre el grupo de lesión miocárdica y el grupo de lesión no miocárdica en términos de complicaciones médicas (33% [14/42] versus 9% [50/544]; p <0,01) pero no complicaciones quirúrgicas (19% [8/42] versus 16% [85/544]; p = 0,56). La lesión miocárdica fue un predictor independiente de complicaciones posoperatorias dentro de los 90 días posteriores a la cirugía (razón de probabilidades ajustada: 2,69; intervalo de confianza del 95%: 1,31 - 5,55).LIMITACIONES:Limitado por su diseño retrospectivo.CONCLUSIÓN:La lesión del miocardio ocurre con frecuencia en pacientes sometidos a cirugía de cáncer colorrectal en un protocolo de recuperación mejorada después de la cirugía. Los pacientes con lesión miocárdica no tuvieron una mortalidad significativamente mayor a los 90 días, pero tuvieron un mayor riesgo de complicaciones posoperatorias a los 90 días en comparación con los pacientes sin lesión miocárdica. Las investigaciones futuras deben examinar la prevención y el tratamiento de la lesión miocárdica. Consulte Video Resumen en http://links.lww.com/DCR/B692.

Economic cost of smoking and secondhand smoke exposure in the Gulf Cooperation Council countries.

BACKGROUND: The economic cost of smoking has been determined in many high-income countries as well as at a global level. This paper estimates the economic cost of smoking and secondhand smoke (SHS) exposure in the six Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates), for which no detailed study exists. METHODS: We used data from the Global Burden of Diseases Study 2016 and the cost-of-illness approach to estimate direct costs (healthcare expenditures) and indirect costs (productivity losses due to morbidity and mortality). Indirect cost was estimated with and without the inclusion of musculoskeletal disorders, using the human capital approach. RESULTS: Total cost of smoking and SHS was estimated to be purchasing power parity (PPP)$ 34.5 billion in 2016, equivalent to 1.04% of the combined gross domestic product (GDP). SHS accounted for 20.4% of total cost. The highest proportion of indirect cost resulted from smoking in men and middle-aged people. The main causes of morbidity cost from smoking and SHS were chronic respiratory diseases and type 2 diabetes mellitus, respectively. Cardiovascular diseases were the main contributor to mortality cost for both smoking and exposure to SHS. Including musculoskeletal disorders increased total cost to PPP$ 41.3 billion (1.25% of the combined GDP). CONCLUSION: The economic cost of smoking and SHS in the GCC states is relatively low compared with other high-income countries. Scaling-up implementation of evidence-based policies will prevent the evolution of a tobacco epidemic with its negative consequences for health and public finances.

Use of Twitter in Neurology: Boon or Bane?

Twitter is a free, open access social media platform that is widely used in medicine by physicians, scientists, and patients. It provides an opportunity for advocacy, education, and collaboration. However, it is likely not utilized to its full advantage by many disciplines in medicine, and pitfalls exist in its use. In particular, there has not been a review of Twitter use and its applications in the field of neurology. This review seeks to provide an understanding of the current use of Twitter in the field of neurology to assist neurologists in engaging with this potentially powerful application to support their work.

Records of two gonad-infecting species of Philometra (Nematoda: Philometridae) from marine fishes off Iraq, including the description of Philometra parabrevicollis n. sp. from the bigeye snapper Lutjanus lutjanus Bloch (Pisces, Lutjanidae).

Recent examinations of some marine fishes from off the southern coast of Iraq revealed the presence of two species of Philometra Costa, 1845 (Nematoda: Philometridae): P. parabrevicollis n. sp. (males and subgravid and nongravid females) from the ovary of the bigeye snapper Lutjanus lutjanus Bloch (Perciformes, Lutjanidae) and Philometra sp. (subgravid females) from the ovary of the bartail flathead Platycephalus indicus (Linnaeus) (Perciformes, Platycephalidae). Specimens of species are described and illustrated based on light and scanning electron microscopical examinations. Philometra parabrevicollis n. sp. is mainly characterised by the length of spicules (267-285 µm) and gubernaculum (159-168 µm), the gubernaculum/spicule length ratio (1:1.64-1.76), the structure of the gubernaculum distal tip and of the male caudal end, and the body length of males (4.03-4.90 mm). The description of this new species again confirms a high degree of host specificity of gonad-infecting species of Philometra in congeneric lutjanid hosts. Although Philometra sp. parasitising P. indicus in Iraqi waters was previously recorded, its subgravid females are described for the first time. A key to gonad-infecting species of Philometra parasitic in fishes of the family Lutjanidae is provided.

Axial and peripheral spondyloarthritis triggered by sars-cov-2 infection: a report of two cases.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can show musculoskeletal symptoms such as peripheral arthritis. In rare cases, peripheral arthritis can develop after the resolution of SARS-CoV-2. We present two cases of spondyloarthritis induced by SARS-CoV-2; one case with axial and peripheral spondyloarthritis and the other with peripheral spondyloarthritis. Both cases refer to Lebanese patients who were HLA-B27 positive. These two cases highlight the possible predisposition of HLA-B27 positive patients to the development of spondyloarthritis symptoms triggered by SARS-CoV-2.

Global Survey on Telemedicine Utilization for Movement Disorders During the COVID-19 Pandemic.

BACKGROUND: The COVID-19 pandemic restricted usual healthcare management for movement-disorders patients, with a consequent upsurge in telemedicine to bridge the gap. OBJECTIVE: To assess global telemedicine usage in the context of the pandemic. METHODS: The Movement Disorder Society (MDS) Telemedicine Study Group surveyed telemedicine experts from 40 countries across all continents in March-April 2020. Four domains of telemedicine were assessed: legal regulations, reimbursement, clinical use, and barriers; comparing emerging responses to the pandemic versus the baseline scenario. RESULTS: All forms of telemedicine for movement disorders increased globally, irrespective of country income categorization, as an immediate response to the pandemic. This was aided by widespread availability of technology and updated government regulations. However, privacy concerns, lack of reimbursement, limited access, and lack of telemedicine training were barriers highlighted worldwide. CONCLUSIONS: Questions remain about the longevity and extent of changes in regulations and reimbursement regarding telemedicine in the aftermath of the pandemic. © 2020 International Parkinson and Movement Disorder Society.

The Amino Terminus of LeuT Changes Conformation in an Environment Sensitive Manner.

Neurotransmitter:sodium symporters are highly expressed in the human brain and catalyze the uptake of substrate through the plasma membrane by using the electrochemical gradient of sodium as the energy source. The bacterial homolog LeuT, a small amino acid transporter isolated from the bacteria Aquifex aeolicus, is the founding member of the family and has been crystallized in three conformations. The N-terminus is structurally well defined and strongly interacts with the transporter core in the outward-facing conformations. However, it could not be resolved in the inward-facing conformation, which indicates enhanced mobility. Here we investigate conformations and dynamics of the N-terminus, by combining molecular dynamics simulations with experimental verification using distance measurements and accessibility studies. We found strongly increased dynamics of the N-terminus, but also that helix TM1A is subject to enhanced mobility. TM1A moves towards the transporter core in the membrane environment, reaching a conformation that is closer to the structure of LeuT with wild type sequence, indicating that the mutation introduced to create the inward-facing structure might have altered the position of helix TM1A. The mobile N-terminus avoids entering the open vestibule of the inward-facing state, as accessibility studies do not show any reduction of quenching by iodide of a fluorophore attached to the N-terminus.

LiFi grid: a machine learning approach to user-centric design.

A novel machine learning (ML) clustering algorithm, named light-fidelity (LiFi) Grid, is proposed to design amorphous cells of LiFi access points (APs) in order to maximize the minimum signal-to-interference-plus-noise ratio (SINR) from the viewpoint of user-centric (UC) network design. The algorithm consists of two phases. Explicitly, the first phase consists of finding clusters of user densities based on the mean-shift (MS) clustering algorithm. In contrast to some other clustering algorithms, such as K-means, MS does not need to know the number of clusters in advance. Furthermore, the combined transmission scheme is assumed in each cell. In the second phase, this paper proposes a novel clustering algorithm that addresses the problem of grouping APs based on the positions of users-UC design-in optical wireless networks (OWNs). Hence, it addresses the dynamic resource allocation problem in OWNs if APs are considered as network resources. Based on the maximization of minimum SINR metric, LiFi Grid demonstrates the superior performance relative to conventional fixed-shape cell-centric network designs. Additionally, full compatibility of the LiFi Grid clustering algorithm with the Institute of Electrical and Electronics Engineers standard 802.15.7 is also shown.

LiFi grid: a machine learning approach to user-centric design: publisher's note.

This publisher's note amends the author listing and affiliation section in Appl. Opt.59, 8895 (2020)APOPAI0003-693510.1364/AO.396804.