ABSTRACT
The mud crab (Scylla paramamosain) is a commercially significant marine decapod crustacean. Due to its obvious sexual dimorphism, the mechanism of sex differentiation and gonadal development has attracted significant research interest. The Dmrt (double-sex and mab-3 related transcription factor) genes are vital in animal gonadal development and sex differentiation. In the present study, miR-34 was predicted to target the 3' end of Dmrt-1, idmrt-2, Dmrt-3, Dsx and Dmrt-like genes by prediction software, and the interactions between miR-34 and these Dmrt genes were validated by in vivo and in vitro experiments. Dual luciferase assay results indicated that miR-34 mimics/inhibitors co-transfected with plasmid vectors with 3' end of Dmrt-1, idmrt-2, Dmrt-3, Dsx and Dmrt-like, respectively, led to a significant decrease/increase of fluorescence activity in HEK293T cells. In vivo experiments showed that injection of agomir-34 significantly inhibited Dmrt-1, idmrt-2, Dsx and Dmrt-like expression, while injection of antagomir-34 caused the opposite result. However, Dmrt-3 expression was not affected by injection of the antagomir. Meanwhile, the expression of spermatogenesis and testicular development-related molecular marker genes (IAG, foxl2 and vasa) in mud crabs was significantly changed after injecting the miR-34 reagent in vivo. Furthermore, the result of immunoblotting proved that the expression level of Dmrt-like protein can be regulated by miR-34. These results imply that miR-34 is indirectly involved in sex differentiation and testicular development of S. paramamosain by regulating Dmrt-1, idmrt-2, Dsx and Dmrt-like genes.
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In the realm of neuroscience, mapping the three-dimensional (3D) neural circuitry and architecture of the brain is important for advancing our understanding of neural circuit organization and function. This study presents a novel pipeline that transforms mouse brain samples into detailed 3D brain models using a collaborative data analytics platform called "Texera." The user-friendly Texera platform allows for effective interdisciplinary collaboration between team members in neuroscience, computer vision, and data processing. Our pipeline utilizes the tile images from a serial two-photon tomography/TissueCyte system, then stitches tile images into brain section images, and constructs 3D whole-brain image datasets. The resulting 3D data supports downstream analyses, including 3D whole-brain registration, atlas-based segmentation, cell counting, and high-resolution volumetric visualization. Using this platform, we implemented specialized optimization methods and obtained significant performance enhancement in workflow operations. We expect the neuroscience community can adopt our approach for large-scale image-based data processing and analysis.
Subject(s)
Brain , Workflow , Animals , Brain/diagnostic imaging , Brain/physiology , Mice , Imaging, Three-Dimensional/methods , Image Processing, Computer-Assisted/methods , SoftwareABSTRACT
Osteoarthritis is a chronic degenerative disease based on the degeneration and loss of articular cartilage. Inflammation and aging play an important role in the destruction of the extracellular matrix, in which microRNA (miRNA) is a key point, such as miRNA-34a-5p. Upregulation of miRNA-34a-5p was previously reported in a rat OA model, and its inhibition significantly suppressed interleukin (IL)-1ß-induced apoptosis in rat chondrocytes. However, Oxidative stress caused by reactive oxygen species (ROS) can exacerbate the progression of miRNA regulated OA by mediating inflammatory processes. Thus, oxidative stress effects induced via tert-butyl hydroperoxide (tBHP) in human chondrocytes were assessed in the current research by evaluating mitochondrial ROS production, mitochondrial cyclooxygenase (COX) activity, and cell apoptosis. We also analyzed the activities of antioxidant enzymes including glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD). Additionally, inflammatory factors, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8, and IL-24, which contribute to OA development, were detected by enzyme-linked immunosorbent assay (ELISA). The results of this study indicated that miR-34a-5p/silent information regulator 1 (SIRT1)/p53 axis was involved in the ROS-induced injury of human chondrocytes. Moreover, dual-luciferase assay revealed that SIRT1 expression was directly regulated by miR-34a-5p, indicating the presence of a positive feedback loop in the miR-34a-5p/SIRT1/p53 axis that plays an important role in cell survival. However, ROS disrupted the miR-34a-5p/SIRT1/p53 axis, leading to the development of OA, and articular injection of SIRT1 agonist, SRT1720, in a rat model of OA effectively ameliorated OA progression in a dose-dependent manner. Our study confirms that miRNA-34a-5p could participate in oxidative stress responses caused by ROS and further regulate the inflammatory process via the SIRT1/p53 signaling axis, ultimately affecting the onset of OA, thus providing a new treatment strategy for clinical treatment of OA.
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Mud crab (Scylla paramamosain) has become an important mariculture crab along the southeast coast of China due to its strong adaptability, delicious taste, and rich nutrition. Several vertebrate steroid hormones and their synthesis-related genes and receptors have been found in crustaceans, but there are few reports on their synthesis process and mechanism. 3-beta-hydroxysteroid dehydrogenase (HSD3B) is a member of the Short-chain Dehydrogenase/Reductase (SDR) family, and an indispensable protein in vertebrates' steroid hormone synthesis pathway. In this study, the SpHsd3b gene sequence was obtained from the transcriptome data of S. paramamosain, and its full-length open reading frame (ORF) was cloned. The spatial and temporal expression pattern of SpHsd3b was performed by quantitative real-time PCR (qRT-PCR). SpHsd3b dsRNA interference (RNAi) and HSD3B inhibitor (trilostane) were used to analyze the function of SpHSD3B. The results showed that the SpHsd3b gene has an 1113â¯bp ORF encoding 370 amino acids with a 3ß-HSD domain. SpHSD3B has lower homology with HSD3B of vertebrates and higher homology with HSD3B of crustaceans. SpHsd3b was expressed in all examined tissues in mature crabs, and its expression was significantly higher in the testes than in the ovaries. SpHsd3b expression level was highest in the middle stage of testicular development, while its expression was higher in the early and middle stages of ovarian development. RNAi experiment and trilostane injection results showed that SpHSD3B had regulatory effects on several genes related to gonadal development and steroid hormone synthesis. 15-day trilostane suppression could also inhibit ovarian development and progesterone level of hemolymph. According to the above results, crustaceans may have steroid hormone synthesis pathways like vertebrates, and the Hsd3b gene may be involved in the gonadal development of crabs. This study provides further insight into the function of genes involved in steroid hormone synthesis in crustaceans.
Subject(s)
Brachyura , Phylogeny , Animals , Brachyura/genetics , Brachyura/growth & development , Brachyura/metabolism , Brachyura/enzymology , Female , Male , Amino Acid Sequence , 3-Hydroxysteroid Dehydrogenases/genetics , 3-Hydroxysteroid Dehydrogenases/metabolism , Ovary/metabolism , Ovary/growth & development , Cloning, Molecular , RNA Interference , Dihydrotestosterone/analogs & derivativesABSTRACT
Toll-like receptors (TLRs) are one of the extensively studied pattern recognition receptors (PRRs) and play crucial roles in the immune responses of vertebrates and invertebrates. In this study, 14 TLR genes were identified from the genome-wide data of Octopus sinensis. Protein structural domain analysis showed that most TLR proteins had three main structural domains: extracellular leucine-rich repeats (LRR), transmembrane structural domains, and intracellular Toll/IL-1 receptor domain (TIR). The results of subcellular localization prediction showed that the TLRs of O. sinensis were mainly located on the plasma membrane. The results of quantitative real-time PCR (qPCR) showed that the detected TLR genes were differentially expressed in the hemolymph, white bodies, hepatopancreas, gills, gill heart, intestine, kidney, and salivary gland of O. sinensis. Furthermore, the present study investigated the expression changes of O. sinensis TLR genes in hemolymph, white bodies, gills, and hepatopancreas in different phases (6 h, 12 h, 24 h, 48 h) after stimulation with PGN, poly(I: C) and Vibrio parahaemolyticus. The expression of most of the TLR genes was upregulated at different time points after infection with pathogens or stimulation with PAMPs, a few genes were unchanged or even down-regulated, and many of the TLR genes were much higher after V. parahaemolyticus infection than after PGN and poly(I:C) stimulation. The results of this study contribute to a better understanding of the molecular immune mechanisms of O. sinensis TLRs genes in resistance to pathogen stimulation.
Subject(s)
Gene Expression Regulation , Immunity, Innate , Octopodiformes , Toll-Like Receptors , Vibrio parahaemolyticus , Animals , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology , Toll-Like Receptors/chemistry , Vibrio parahaemolyticus/physiology , Octopodiformes/genetics , Octopodiformes/immunology , Immunity, Innate/genetics , Gene Expression Regulation/immunology , Phylogeny , Gene Expression Profiling/veterinary , Poly I-C/pharmacology , Peptidoglycan/pharmacology , Arthropod Proteins/genetics , Arthropod Proteins/immunology , Arthropod Proteins/chemistry , Pathogen-Associated Molecular Pattern Molecules/pharmacologyABSTRACT
OBJECTIVE: Non-tobacco blunt wraps (N-TBWs), which entered the marketplace in 2017, are being promoted as an alternative to traditional TBWs (e.g., cigarillos) for blunt smoking. The lack of studies on these novel products warrants an investigation. This study was the first to explore blunt smokers' perceptions about N-TBWs and the extent of product marketing on Twitter. METHODS: A corpus of tweets from Twitter, posted between January 2017 and November 2021, were identified by a Boolean search string (N = 149,343), where 48,695 tweets were classified as relevant by a machine learning algorithm. These relevant tweets were further screened and labeled as promotional or organic based on product URLs, usernames, keywords, or hashtags. Topic modeling using Dirichlet Allocation was then employed for identifying latent patterns of words among relevant tweets. The Social Networking Potential (SNP) score was employed for identifying influential accounts. RESULTS: Most relevant tweets (89%) were organic, non-promotional expressions about N-TBWs. Account users who only posted non-promotional tweets had a significantly higher SNP than those who only posted promotional tweets. Yet, neither of the two groups of account users consisted of known celebrities. Topic modeling revealed three broad groups of topics (7 in total) denoting the attributes of hemp N-TBWs, interest in non-hemp N-TBWs, and product marketing. CONCLUSIONS: The large proportion of organic tweets is indicative of the nascency of N-TBWs, which will need to be marketed more extensively if they are to replace cigar products used by blunt smokers.
Subject(s)
Social Media , Tobacco Products , Humans , Marketing , SmokingABSTRACT
BACKGROUND: Although duloxetine has shown a positive effect on pain relief with hip and knee osteoarthritis, there is no pooled analysis of duloxetine for pain relief and opioid consumption in patients after total hip or knee arthroplasty. AIM: This systematic review and meta-analysis aimed to analyze pain control, opioid consumption, and associated adverse events of perioperative administration of duloxetine after total hip or knee arthroplasty. METHOD: After being registered with PROSPERO (CRD42022323202), the databases of MEDLINE, PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov were searched from inception until March 20, 2023, for randomized controlled trials (RCTs). Primary outcomes were the visual Analog Scale (VAS) pain scores at rest (rVAS) and upon ambulation (aVAS). Secondary outcomes were postoperative opioid consumption quantified as oral morphine milligram equivalents (MMEs) and adverse effects of duloxetine. RESULTS: Nine RCTs with 806 cases were included. Duloxetine was associated with lower VAS scores at different times after surgery (24 h, two weeks, and ≥ 3 months). Compared to placebo, perioperative daily duloxetine use significantly reduced daily opioid MMEs at 24 h (standard mean deviation [SMD] -0.71, 95% confidence interval [95% CI] -1.19 to -0.24, P = 0.003), three days (SMD -1.10, 95% CI -1.70 to -0.50, P = 0.0003), and one week (SMD -1.18, 95% CI -1.99 to -0.38, P = 0.004) after surgery. The duloxetine group had a significantly lower rate of nausea (odds ratio 0.62, 95% CI [0.41 to 0.94], P = 0.02) and a higher rate of drowsiness and somnolence (odds ratio 1.87, 95% CI [1.13 to 3.07], P = 0.01) compared to the placebo group. No significant differences were observed in the rates of other adverse events. CONCLUSION: Perioperative duloxetine significantly decreased postoperative pain and opioid consumption with good safety profiles. Further high quality designed and well-controlled randomized trials are warranted.
Subject(s)
Analgesics, Opioid , Arthroplasty, Replacement, Hip , Humans , Analgesics, Opioid/adverse effects , Duloxetine Hydrochloride/adverse effects , Arthroplasty, Replacement, Hip/adverse effects , Randomized Controlled Trials as Topic , Pain, Postoperative/drug therapy , Pain, Postoperative/etiologyABSTRACT
Public sentiment toward the COVID-19 vaccine as expressed on social media can interfere with communication by public health agencies on the importance of getting vaccinated. We investigated Twitter data to understand differences in sentiment, moral values, and language use between political ideologies on the COVID-19 vaccine. We estimated political ideology, conducted a sentiment analysis, and guided by the tenets of moral foundations theory (MFT), we analyzed 262,267 English language tweets from the United States containing COVID-19 vaccine-related keywords between May 2020 and October 2021. We applied the Moral Foundations Dictionary and used topic modeling and Word2Vec to understand moral values and the context of words central to the discussion of the vaccine debate. A quadratic trend showed that extreme ideologies of both Liberals and Conservatives expressed a higher negative sentiment than Moderates, with Conservatives expressing more negative sentiment than Liberals. Compared to Conservative tweets, we found the expression of Liberal tweets to be rooted in a wider set of moral values, associated with moral foundations of care (getting the vaccine for protection), fairness (having access to the vaccine), liberty (related to the vaccine mandate), and authority (trusting the vaccine mandate imposed by the government). Conservative tweets were found to be associated with harm (around safety of the vaccine) and oppression (around the government mandate). Furthermore, political ideology was associated with the expression of different meanings for the same words, e.g. "science" and "death." Our results inform public health outreach communication strategies to best tailor vaccine information to different groups.
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Background: Atrophie blanche (AB) is a thrombotic vascular disease, also known as venous vasculitis or segmental hyaline vasculitis, characterized by chronic recurring painful ulcers on the lower legs, especially the ankles. AB is a clinically rare condition, affecting 1%-5% of the population, specifically middle-aged women with an average age of 45 years, and cases of AB in children are rare. Following recovery, ivory-white atrophy spots accompanied by pigmentation and telangiectasia remain in patients. One of the complications of AB is the parasitic growth of microorganisms infecting the ischemic soft tissue undergoing necrosis in the lower limbs. Furthermore, although infection combined with microbial parasitism is a type of surgical site infection, myiasis is particularly rare, which may warrant limb amputation or may even be life-threatening. Understanding the complications of AB may help in early and timely surgical debridement as well as wound repair. Summarizing the knowledge and treatment strategies of AB and formulating clinical strategies and guidelines for AB management with insights from relevant cases are important. Case summary: A 59-year-old woman was hospitalized due to repeated ulceration of the skin of the right lower leg for 3 years, aggravation, and maggot growth for 3 days. In the previous 3 years, the skin and soft tissue of the right calf had become ischemic, necrotic, and infected, but the patient did not seek any medical treatment. Subsequently, 2 years ago, she was diagnosed with AB at the dermatology department of our hospital. After hormone treatment, her right leg improved. However, 1 year ago, the skin and soft tissue of the right leg again became ischemic, necrotic, and infected. This time, the patient did not seek medical treatment and applied musk on her wound. The wound deepened, resulting in the exposure of the tendon and some bones. In addition, a large number of maggots and microorganisms grew in and infested the wound for 3 days before the patient came to our department for treatment. Debridement of the necrotizing infected site on the right lower leg combined with negative pressure vacuum sealing drainage were performed twice within 16 days after admission. Simultaneously, antibiotics were given systemically. On the 17th day after admission, the wound appeared clean, myiasis had resolved, and the growth and coverage of the granulation tissue on the wound were satisfactory. Subsequently, debridement of the infected site on the right leg, removal of skin of the right thigh, and autologous free skin grafting were performed. After 10 days, the wound was clean, all skin grafts had survived, and wound repair was satisfactory. Finally, the patient was discharged after 38 days of hospitalization. Conclusion: Although AB is rare, leukodystrophy requires specialized treatment and regular follow-up. If lower limb infection and maggot growth occur simultaneously, self-treatment should be avoided and medical attention must be sought immediately. Early implementation of wound debridement and anti-infective treatment combined with wound repair, which should be performed after cleaning the wound, is advised.
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Recently, there has been a focus on drawing progress on representation learning to obtain more identifiable and interpretable latent representations for spike trains, which helps analyze neural population activity and understand neural mechanisms. Most existing deep generative models adopt carefully designed constraints to capture meaningful latent representations. For neural data involving navigation in cognitive space, based on insights from studies on cognitive maps, we argue that the good representations should reflect such directional nature. Due to manifold mismatch, models utilizing the Euclidean space learn a distorted geometric structure that is difficult to interpret. In the present work, we explore capturing the directional nature in a simpler yet more efficient way by introducing hyperspherical neural latent variable models (SNLVM). SNLVM is an improved deep latent variable model modeling neural activity and behavioral variables simultaneously with hyperspherical latent space. It bridges cognitive maps and latent variable models. We conduct experiments on modeling a static unidirectional task. The results show that while SNLVM has competitive performance, a hyperspherical prior naturally provides more informative and significantly better latent structures that can be interpreted as spatial cognitive maps.
Subject(s)
Learning , Models, Theoretical , Humans , CognitionABSTRACT
N-acetyltransferase 10 (NAT10) is a nucleolar acetyltransferase and has been reported to facilitate tumorigenesis in various cancers, but its role in NSCLC and how it is regulated remain to be assessed. The expression of NAT10 was explored in online databases and our collected clinical specimens. The relationship of NAT10 and clinical characteristics was evaluated using the online databases. Functional analyses were utilized to determine the effect of NAT10 on the proliferation and migration abilities. KEGG pathway analyses were conducted to investigate NAT10-related pathways in NSCLC. The influence of NAT10 on cell cycle was assessed by flow cytometry and cell synchronization assay. The association between c-myc and NAT10 promoter was determined by ChIP. Compared with normal tissue, NAT10 was significantly overexpressed in NSCLC. Upregulated NAT10 was associated with more advanced stage for lung adenocarcinoma and shorter overall survival and first progression time for lung cancer. NAT10 could promote proliferation and migration of NSCLC cells in vitro. c-myc positively regulated the expression of NAT10 as a transcription factor. KEGG pathway analyses indicated that NAT10 was significantly involved in cell cycle regulation, cytokine-cytokine receptor interaction and other pathways. The knockdown of NAT10-induced G1 arrest, which was possibly mediated by the downregulation of cyclin D1.Our findings suggested that c-myc-mediated upregulation of NAT10 promoted the proliferation and migration of NSCLC cells and NAT10 might be a marker for prognosis and a promising target for treatment in NSCLC.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Cell Cycle , Lung Neoplasms , N-Terminal Acetyltransferases , Proto-Oncogene Proteins c-myc , Acetyltransferases/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation, Neoplastic/genetics , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , N-Terminal Acetyltransferases/genetics , N-Terminal Acetyltransferases/metabolism , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Up-RegulationABSTRACT
Big data era has brought big challenge for firms in human resource management, especially in employees' emotion. Drawing on emotion regulation and leadership theories, this study tests the mediating roles of emotion regulation for cognitive reappraisal and expressive suppression in the relationship between spiritual leadership and job engagement. We made a field survey with 203 full-time employees to test our hypotheses. Empirical results show that the mediating effects of both cognitive reappraisal and expressive suppression in accounting for the relationship between spiritual leadership and job engagement. Our study is among the first to examine whether and why spiritual leadership predicts job engagement. Our study contributes to the literatures on job engagement and emotion regulation.
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Latent variable models (LVMs) for neural population spikes have revealed informative low-dimensional dynamics about the neural data and have become powerful tools for analyzing and interpreting neural activity. However, these approaches are unable to determine the neurophysiological meaning of the inferred latent dynamics. On the other hand, emerging evidence suggests that dynamic functional connectivities (DFC) may be responsible for neural activity patterns underlying cognition or behavior. We are interested in studying how DFC are associated with the low-dimensional structure of neural activities. Most existing LVMs are based on a point process and fail to model evolving relationships. In this work, we introduce a dynamic graph as the latent variable and develop a Variational Dynamic Graph Latent Variable Model (VDGLVM), a representation learning model based on the variational information bottleneck framework. VDGLVM utilizes a graph generative model and a graph neural network to capture dynamic communication between nodes that one has no access to from the observed data. The proposed computational model provides guaranteed behavior-decoding performance and improves LVMs by associating the inferred latent dynamics with probable DFC.
ABSTRACT
While it has been scientifically proven that COVID-19 vaccine is a safe and effective measure to reduce the severity of infection and curbing the spread of the SARS-CoV-2 virus, skepticism remains widespread, and in many countries vaccine mandates have been met with strong opposition. In this study, we applied machine learning-based analyses of the U.S.-based tweets covering the periods leading toward and after the Biden Administration's announcement of federal vaccine mandates, supplemented by a qualitative content analysis of a random sample of relevant tweets. The objective was to examine the beliefs held among twitter users toward vaccine mandates, as well as the evidence that they used to support their positions. The results show that while approximately 30% of the twitter users included in the dataset supported the measure, more users expressed differing opinions. Concerns raised included questioning on the political motive, infringement of personal liberties, and ineffectiveness in preventing infection.
Subject(s)
COVID-19 , Social Media , Humans , Public Opinion , COVID-19 Vaccines , SARS-CoV-2 , Machine LearningABSTRACT
INTRODUCTION: Twitter represents a mainstream news source for the American public, offering a valuable vehicle for learning how citizens make sense of pandemic health threats like Covid-19. Masking as a risk mitigation measure became controversial in the US. The social amplification risk framework offers insight into how a risk event interacts with psychological, social, institutional, and cultural communication processes to shape Covid-19 risk perception. METHODS: Qualitative content analysis was conducted on 7,024 mask tweets reflecting 6,286 users between January 24 and July 7, 2020, to identify how citizens expressed Covid-19 risk perception over time. Descriptive statistics were computed for (a) proportion of tweets using hyperlinks, (b) mentions, (c) hashtags, (d) questions, and (e) location. RESULTS: Six themes emerged regarding how mask tweets amplified and attenuated Covid-19 risk: (a) severity perceptions (18.0%) steadily increased across 5 months; (b) mask effectiveness debates (10.7%) persisted; (c) who is at risk (26.4%) peaked in April and May 2020; (d) mask guidelines (15.6%) peaked April 3, 2020, with federal guidelines; (e) political legitimizing of Covid-19 risk (18.3%) steadily increased; and (f) mask behavior of others (31.6%) composed the largest discussion category and increased over time. Of tweets, 45% contained a hyperlink, 40% contained mentions, 33% contained hashtags, and 16.5% were expressed as a question. CONCLUSIONS: Users ascribed many meanings to mask wearing in the social media information environment revealing that COVID-19 risk was expressed in a more expanded range than objective risk. The simultaneous amplification and attenuation of COVID-19 risk perception on social media complicates public health messaging about mask wearing.
Subject(s)
COVID-19/prevention & control , Masks/virology , Pandemics/prevention & control , Social Media/statistics & numerical data , Communication , Humans , Longitudinal Studies , Perception/physiology , Public Health/statistics & numerical data , Public Opinion , Risk-Taking , SARS-CoV-2/pathogenicity , United StatesABSTRACT
OBJECTIVE: Facial masks are an essential personal protective measure to fight the COVID-19 (coronavirus disease) pandemic. However, the mask adoption rate in the United States is still less than optimal. This study aims to understand the beliefs held by individuals who oppose the use of facial masks, and the evidence that they use to support these beliefs, to inform the development of targeted public health communication strategies. MATERIALS AND METHODS: We analyzed a total of 771 268 U.S.-based tweets between January to October 2020. We developed machine learning classifiers to identify and categorize relevant tweets, followed by a qualitative content analysis of a subset of the tweets to understand the rationale of those opposed mask wearing. RESULTS: We identified 267 152 tweets that contained personal opinions about wearing facial masks to prevent the spread of COVID-19. While the majority of the tweets supported mask wearing, the proportion of anti-mask tweets stayed constant at about a 10% level throughout the study period. Common reasons for opposition included physical discomfort and negative effects, lack of effectiveness, and being unnecessary or inappropriate for certain people or under certain circumstances. The opposing tweets were significantly less likely to cite external sources of information such as public health agencies' websites to support the arguments. CONCLUSIONS: Combining machine learning and qualitative content analysis is an effective strategy for identifying public attitudes toward mask wearing and the reasons for opposition. The results may inform better communication strategies to improve the public perception of wearing masks and, in particular, to specifically address common anti-mask beliefs.
Subject(s)
Attitude to Health , COVID-19/prevention & control , Machine Learning , Masks , Social Media , Humans , Public Opinion , United StatesABSTRACT
In this work, we investigated the mid-infrared (MIR) optical properties of selenide (Se-based) chalcogenide glasses (ChGs) within an As- and Ge-free system, namely the environment-friendly and low-cost tin-antimony-selenium (Sn-Sb-Se, SSS) ternary system, which has not been systematically studied to the best of our knowledge. As compared to ChGs within those conventional Se-based systems, SSS ChGs were found to exhibit extended infrared transmittance range as well as larger linear refractive index (n0). Femtosecond Z-scan measurements show the presence of evident three-photon absorption from Urbach absorption of the SSS ChGs at MIR wavelength, which resonantly enhanced the nonlinear refractive behavior and resulted in large nonlinear refractive index (n2).
ABSTRACT
We report the fabrication of a novel high nonlinear fiber made of Ge-Sb-Se chalcogenide glasses with high numerical aperture (â¼1.0), where the core and the cladding glasses consist of Ge15Sb25Se60 and Ge15Sb20Se65 (mol. %), respectively. The nonlinear refractive index (n2) of the core glass is 19×10-18 m2/W at 1.55 µm, and its laser-induced damage threshold under irradiation of 3.0 µm fs laser is approximately 3674 GW/cm2. By pumping a 20-cm-long fiber with a core diameter of 23 µm using 150 fs pulses at 6.0 µm, supercontinuum spanning from â¼1.8 to â¼14 µm was generated.
ABSTRACT
Two series of chalcogenide glasses in Ge-Sb-S ternary system were synthesized with melt-quenching method. The phycochemical properties and spectral characteristic of glasses with different content of Ge and Sb were obtained with a series of measurements, and the systematic analysis on the change of optical properties was conducted in terms of microstructure of glasses combined with the Raman spectra. With constraint theory based on mean coordination number (Z), we described the variation trend of network structure directly. It was found that as long as the value of Z reaches 2.6, new vibration peaks would be formed in the Raman spectra indicating the presence of threshold behavior as well as the change of the network structure of the Ge-Sb-S glasses which could be expressed in a specific varition in the number of metal bonds and the nonmetal bonds. The appearance of new functional groups in the network have changed the total bond energy of glasses, and then affected the energy band structure of glasses representing the corresponding threshold behavior of the value of optical band gap (Eopg).