bluuebunny/crossref_metadata_2025 huggingface dataset:
Ο ρόλος της διέκπλυσης του καρωτιδικού ενδοαυλικού νάρθηκα στην πρόληψη των καθυστερημένων εμβολικών ισχαιμικών αγγειακών εγκεφαλικών επεισοδίων
Authors: Μήτκα Αφροδίτη - Μαρία
Published: March 2021

Σκοπός: Η παρουσίαση των αποτελεσμάτων της αγγειοπλαστικής της έσω καρωτίδας (CAS) με και χωρίς την διέκπλυση της επιφάνειας του καρωτιδικού ενδονάρθηκα, με στόχο τη μείωση των Αγγειακών Εγκεφαλικών Επεισοδίων (ΑΕΕ). Μέθοδοι: Από τον Μάιο του 2015 έως τον Οκτώβριο του 2017, 125 ασθενείς υποβλήθηκαν σε CAS υπό τοπική αναισθησία με διαμηριαία προσπέλαση. Το δείγμα χωρίστηκε σε δύο ομάδες: Α(63) με διέκπλυση του ενδονάρθηκα και Β(62) χωρίς. Συμπτωματικοί ήταν το 76%. Παρουσία περιφερικού φίλτρου εγκεφαλικής προστασίας τοποθετήθηκε ενδονάρθηκας και η κάθε ομάδα εξετάστηκε με τη χρήση ανοιχτού (Α1-Β1) και κλειστού κελιού (Α2-Β2). Ο μέσος όρος καρωτιδική στένωση ήταν ≥70%. Χρησιμοποιήθηκε ηπαρινισμένος φυσιολογικός ορός 80ml για την διέκπλυση της εσωτερικής επιφάνειας του ενδονάρθηκα πριν την αφαίρεση του φίλτρου (Α1-Β1). Πραγματοποιήθηκε MRI εγκεφάλου 24 ώρες μετεγχειρητικά για την ανίχνευση πιθανών εμβολικών εστιών. Νευρολογικά εκτιμήθηκαν οι ασθενείς πριν και μετά την επέμβαση. Συλλέχθηκα τα φίλτρα και ταξινομήθηκαν με βάση του συλλεγόμενου εμβολικού υλικού. Ο επανέλεγχος των ασθενών πραγματοποιήθηκε σε 1 και 3 μήνες. Αποτελέσματα: Η τεχνική επιτυχία ήταν 99,2%. Μόνο 1 ΑΕΕ παρουσιάστηκε στην ομάδα Α αντί 5 της Β (p=0,097). Κανένα ΠΙΕ δεν εμφάνισαν στην Α αντί 5 στη Β (p=0,018). Στην DW-MRI αποκαλύφθηκαν λιγότερες ασυμπτωματικές εστίες στις Α1-Α2 σε σχέση με τις Β1-Β2 (p=0,001). Στο συλλεγόμενο υλικό αναδείχτηκε περισσότερο υλικό στην Α1, Α2 και Β1σε σχέση με την Β2 (p=<0,001). Δεν παρατηρήθηκε κανένας θάνατος και νοσηλεία στη ΜΕΘ. Στον επανέλεγχο δεν παρατηρήθηκε νέα νευρολογική σημειολογία. Συμπέρασμα: Η τεχνική της διέκπλυσης του ενδονάρθηκα είναι μια ασφαλής και αποτελεσματική διαδικασία με ευνοϊκά αποτελέσματα.
An exploratory study of social media users’ engagement with COVID-19 vaccine-related content
Authors: Al-Zaman Md. Sayeed
Published: March 2021

Background: Facebook, as the world’s most popular social media platform, has been playing various important roles throughout the COVID-19 pandemic, allowing users to produce and share health-related information that both eases and complicates public health communication. However, the characteristics of vaccine-related Facebook content and users’ reaction to the vaccine issue has been an unexplored area to date.

Methods: To fill the previous knowledge-gap, this exploratory study wants to understand the communication climate of Facebook on the COVID-19 vaccine issue, including the nature of dominant content and users’ engagement patterns with them. Therefore, the study analyzes the 10,000 most popular Facebook posts with the highest interactions on the vaccine issue.

Results: The results show that Facebook users prioritize more vaccine-related news links (71.22%) over other content. The declining interactions on the issue suggests that interaction growth mainly depends on positive news on the vaccine. Finally, users’ reaction to the vaccine issue is dominantly positive, though they may show a highly negative attitude toward vaccine misinformation.

Conclusions: A few limitations and strengths of this study are discussed along with values and implications. This study for the first time analyzes Bangla language-based Facebook content related to the COVID-19 vaccine issue, which is largely overlooked in global academic research.
Adaptive Learning of Drug Quality and Optimization of Patient Recruitment for Clinical Trials with Dropouts
Authors: Tian Zhili , Han Weidong , Powell Warren B.
Published: March 2021

Problem definition: Clinical trials are crucial to new drug development. This study investigates optimal patient enrollment in clinical trials with interim analyses, which are analyses of treatment responses from patients at intermediate points. Our model considers uncertainties in patient enrollment and drug treatment effectiveness. We consider the benefits of completing a trial early and the cost of accelerating a trial by maximizing the net present value of drug cumulative profit. Academic/practical relevance: Clinical trials frequently account for the largest cost in drug development, and patient enrollment is an important problem in trial management. Our study develops a dynamic program, accurately capturing the dynamics of the problem, to optimize patient enrollment while learning the treatment effectiveness of an investigated drug. Methodology: The model explicitly captures both the physical state (enrolled patients) and belief states about the effectiveness of the investigated drug and a standard treatment drug. Using Bayesian updates and dynamic programming, we establish monotonicity of the value function in state variables and characterize an optimal enrollment policy. We also introduce, for the first time, the use of backward approximate dynamic programming (ADP) for this problem class. We illustrate the findings using a clinical trial program from a leading firm. Our study performs sensitivity analyses of the input parameters on the optimal enrollment policy. Results: The value function is monotonic in cumulative patient enrollment and the average responses of treatment for the investigated drug and standard treatment drug. The optimal enrollment policy is nondecreasing in the average response from patients using the investigated drug and is nonincreasing in cumulative patient enrollment in periods between two successive interim analyses. The forward ADP algorithm (or backward ADP algorithm) exploiting the monotonicity of the value function reduced the run time from 1.5 months using the exact method to a day (or 20 minutes) within 4% of the exact method. Through an application to a leading firm’s clinical trial program, the study demonstrates that the firm can have a sizable gain of drug profit following the optimal policy that our model provides. Managerial implications: We developed a new model for improving the management of clinical trials. Our study provides insights of an optimal policy and insights into the sensitivity of value function to the dropout rate and prior probability distribution. A firm can have a sizable gain in the drug’s profit by managing its trials using the optimal policies and the properties of value function. We illustrated that firms can use the ADP algorithms to develop their patient enrollment strategies.
Specialist Interest Groups in the Association of Nephrology Nurses UK
Authors: McManus Breeda , Thomas Nicola , Bangura Binta , Anderson Nicola , Williams Gail , Rhodes Carol
Published: March 2021

Breeda McManus and colleagues detail the Specialist Interest Groups within the Association of Nephrology Nurses UK
Mo/Si lamellar multilayer gratings with high efficiency and enhanced resolution for the x-ray region of 1000–1700eV
Authors: Feng Yufei , Huang Qiushi , Zhuang Yeqi , Sokolov Andrey , Lemke Stephanie , Qi Runze , Zhang Zhong , Wang Zhanshan
Published: March 2021

The d-spacing of the multilayer lamellar grating was theoretically optimized to improve the energy resolution and maintain a high efficiency. Based on the study of the growth behavior of Mo/Si multilayer on the lamellar grating under different sputtering pressures, Ar gas pressure of 1 mTorr was selected, which can fabricate the multilayer with lower roughness and a good replication of the groove shape. An absolute diffraction efficiency of 25.6% and a C
ff
factor of 1.79 were achieved for the -1st order of the Mo/Si lamellar multilayer grating at an energy of 1700 eV.
Simultaneous measurement of gas absorption and path length based on the dual-sideband heterodyne phase-sensitive detection of dispersion spectroscopy
Authors: Zou Mingli , Sun Liqun , Li Shaomin
Published: March 2021

We present a novel approach based on dual-sideband heterodyne phase-sensitive detection of dispersion spectroscopy to realize simultaneous measurement of the gas absorption signal and corresponding path length. The details of heterodyne phase-sensitive detection of dispersion spectroscopy are derived. A standard Mach–Zehnder intensity modulator (MZM) is adopted to generate a spectrum of a carrier and two sidebands. Phase shift of the beatnote signal generated by the two sidebands is detected to retrieve the path length as well as the gas absorption signal. The measurement range of the path length can be adapted by changing the modulation frequency. Proof-of-principle experiments are conducted with methane (CH4) as the absorber which is filled into a gas cell with a variable path length. We also utilize this approach to evaluate the path length of a White cell and meanwhile calibrate the experimental system with different concentrations of methane. The proposed method has a great potential for detecting the path length and gas absorption in multipass cells and the open path environment.
Compact, diode-pumped, unstable cavity Yb:YAG laser and its application in laser shock peening
Authors: Körner Jörg , Zulić Sanin , Reiter Jürgen , Lenski Mathias , Hein Joachim , Bödefeld Ragnar , Rostohar Danijela , Mocek Tomáš , Kaluza Malte C.
Published: March 2021

We present the setup of a compact, q-switched, cryogenically cooled Yb:YAG laser, which is capable of producing over 1 J output energy in a 10 ns pulse at 10 Hz. The system’s design is based on the recently published unstable cavity layout with gain shaping of the spatial intra-cavity intensity distribution. Using a hexagonal homogenized pump beam, the laser generated an according hexagonal output beam profile. The suitability of such laser properties for the intended use in a laser shock peening process is demonstrated. In the experiment an aluminum plate was treated and the generated residual stresses in the sample subsequently measured. Other applications of this laser system like laser pumping or surface cleaning are conceivable.
Genome-wide analysis of DNA replication and DNA double-strand breaks using TrAEL-seq
Authors: Kara Neesha , Krueger Felix , Rugg-Gunn Peter , Houseley Jonathan
Published: March 2021

Faithful replication of the entire genome requires replication forks to copy large contiguous tracts of DNA, and sites of persistent replication fork stalling present a major threat to genome stability. Understanding the distribution of sites at which replication forks stall, and the ensuing fork processing events, requires genome-wide methods that profile replication fork position and the formation of recombinogenic DNA ends. Here, we describe Transferase-Activated End Ligation sequencing (TrAEL-seq), a method that captures single-stranded DNA 3′ ends genome-wide and with base pair resolution. TrAEL-seq labels both DNA breaks and replication forks, providing genome-wide maps of replication fork progression and fork stalling sites in yeast and mammalian cells. Replication maps are similar to those obtained by Okazaki fragment sequencing; however, TrAEL-seq is performed on asynchronous populations of wild-type cells without incorporation of labels, cell sorting, or biochemical purification of replication intermediates, rendering TrAEL-seq far simpler and more widely applicable than existing replication fork direction profiling methods. The specificity of TrAEL-seq for DNA 3′ ends also allows accurate detection of double-strand break sites after the initiation of DNA end resection, which we demonstrate by genome-wide mapping of meiotic double-strand break hotspots in a dmc1Δ mutant that is competent for end resection but not strand invasion. Overall, TrAEL-seq provides a flexible and robust methodology with high sensitivity and resolution for studying DNA replication and repair, which will be of significant use in determining mechanisms of genome instability.
SARS-CoV-2 variants reveal features critical for replication in primary human cells
Authors: Pohl Marie O. , Busnadiego Idoia , Kufner Verena , Glas Irina , Karakus Umut , Schmutz Stefan , Zaheri Maryam , Abela Irene , Trkola Alexandra , Huber Michael , Stertz Silke , Hale Benjamin G.
Published: March 2021

Since entering the human population, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2; the causative agent of Coronavirus Disease 2019 [COVID-19]) has spread worldwide, causing >100 million infections and >2 million deaths. While large-scale sequencing efforts have identified numerous genetic variants in SARS-CoV-2 during its circulation, it remains largely unclear whether many of these changes impact adaptation, replication, or transmission of the virus. Here, we characterized 14 different low-passage replication-competent human SARS-CoV-2 isolates representing all major European clades observed during the first pandemic wave in early 2020. By integrating viral sequencing data from patient material, virus stocks, and passaging experiments, together with kinetic virus replication data from nonhuman Vero-CCL81 cells and primary differentiated human bronchial epithelial cells (BEpCs), we observed several SARS-CoV-2 features that associate with distinct phenotypes. Notably, naturally occurring variants in Orf3a (Q57H) and nsp2 (T85I) were associated with poor replication in Vero-CCL81 cells but not in BEpCs, while SARS-CoV-2 isolates expressing the Spike D614G variant generally exhibited enhanced replication abilities in BEpCs. Strikingly, low-passage Vero-derived stock preparation of 3 SARS-CoV-2 isolates selected for substitutions at positions 5/6 of E and were highly attenuated in BEpCs, revealing a key cell-specific function to this region. Rare isolate-specific deletions were also observed in the Spike furin cleavage site during Vero-CCL81 passage, but these were rapidly selected against in BEpCs, underscoring the importance of this site for SARS-CoV-2 replication in primary human cells. Overall, our study uncovers sequence features in SARS-CoV-2 variants that determine cell-specific replication and highlights the need to monitor SARS-CoV-2 stocks carefully when phenotyping newly emerging variants or potential variants of concern.
Reconstructing feedback representations in the ventral visual pathway with a generative adversarial autoencoder
Authors: Al-Tahan Haider , Mohsenzadeh Yalda
Published: March 2021

While vision evokes a dense network of feedforward and feedback neural processes in the brain, visual processes are primarily modeled with feedforward hierarchical neural networks, leaving the computational role of feedback processes poorly understood. Here, we developed a generative autoencoder neural network model and adversarially trained it on a categorically diverse data set of images. We hypothesized that the feedback processes in the ventral visual pathway can be represented by reconstruction of the visual information performed by the generative model. We compared representational similarity of the activity patterns in the proposed model with temporal (magnetoencephalography) and spatial (functional magnetic resonance imaging) visual brain responses. The proposed generative model identified two segregated neural dynamics in the visual brain. A temporal hierarchy of processes transforming low level visual information into high level semantics in the feedforward sweep, and a temporally later dynamics of inverse processes reconstructing low level visual information from a high level latent representation in the feedback sweep. Our results append to previous studies on neural feedback processes by presenting a new insight into the algorithmic function and the information carried by the feedback processes in the ventral visual pathway.
Viscoelastic properties of wheat gluten in a molecular dynamics study
Authors: Mioduszewski Łukasz , Cieplak Marek
Published: March 2021

Wheat (Triticum spp.) gluten consists mainly of intrinsincally disordered storage proteins (glutenins and gliadins) that can form megadalton-sized networks. These networks are responsible for the unique viscoelastic properties of wheat dough and affect the quality of bread. These properties have not yet been studied by molecular level simulations. Here, we use a newly developed α-C-based coarse-grained model to study ∼ 4000-residue systems. The corresponding time-dependent properties are studied through shear and axial deformations. We measure the response force to the deformation, the number of entanglements and cavities, the mobility of residues, the number of the inter-chain bonds, etc. Glutenins are shown to influence the mechanics of gluten much more than gliadins. Our simulations are consistent with the existing ideas about gluten elasticity and emphasize the role of entanglements and hydrogen bonding. We also demonstrate that the storage proteins in maize and rice lead to weaker elasticity which points to the unique properties of wheat gluten.
Genome-wide association study of fish oil supplementation on lipid traits in 81,246 individuals reveals new gene-diet interaction loci
Authors: Francis Michael , Li Changwei , Sun Yitang , Zhou Jingqi , Li Xiang , Brenna J. Thomas , Ye Kaixiong
Published: March 2021

Fish oil supplementation is widely used for reducing serum triglycerides (TAGs) but has mixed effects on other circulating cardiovascular biomarkers. Many genetic polymorphisms have been associated with blood lipids, including high- and low-density-lipoprotein cholesterol (HDL-C, LDL-C), total cholesterol, and TAGs. Here, the gene-diet interaction effects of fish oil supplementation on these lipids were analyzed in a discovery cohort of up to 73,962 UK Biobank participants, using a 1-degree-of-freedom (1df) test for interaction effects and a 2-degrees-of-freedom (2df) test to jointly analyze interaction and main effects. Associations with P < 1×10−6 in either test (26,157; 18,300 unique variants) were advanced to replication in up to 7,284 participants from the Atherosclerosis Risk in Communities (ARIC) Study. Replicated associations reaching 1df P < 0.05 (2,175; 1,763 unique variants) were used in meta-analyses. We found 13 replicated and 159 non-replicated (UK Biobank only) loci with significant 2df joint tests that were predominantly driven by main effects and have been previously reported. Four novel interaction loci were identified with 1df P < 5×10−8 in meta-analysis. The lead variant in the GJB6-GJB2-GJA3 gene cluster, rs112803755 (A>G; minor allele frequency = 0.041), shows exclusively interaction effects. The minor allele is significantly associated with decreased TAGs in individuals with fish oil supplementation, but with increased TAGs in those without supplementation. This locus is significantly associated with higher GJB2 expression of connexin 26 in adipose tissue; connexin activity is known to change upon exposure to omega-3 fatty acids. Significant interaction effects were also found in three other loci in the genes SLC12A3 (HDL-C), ABCA6 (LDL-C), and MLXIPL (LDL-C), but highly significant main effects are also present. Our study identifies novel gene-diet interaction effects for four genetic loci, whose effects on blood lipids are modified by fish oil supplementation. These findings highlight the need and possibility for personalized nutrition.
Fitness costs of individual and combined pyrethroid resistance mechanisms, kdr and CYP-mediated detoxification, in Aedes aegypti
Authors: Smith Letícia B. , Silva Juan J. , Chen Connie , Harrington Laura C. , Scott Jeffrey G.
Published: March 2021

Background

Aedes aegypti is an important vector of many human diseases and a serious threat to human health due to its wide geographic distribution and preference for human hosts. A. aegypti also has evolved widespread resistance to pyrethroids due to the extensive use of this insecticide class over the past decades. Mutations that cause insecticide resistance result in fitness costs in the absence of insecticides. The fitness costs of pyrethroid resistance mutations in A. aegypti are still poorly understood despite their implications for arbovirus transmission.

Methodology/Principle findings

We evaluated fitness based both on allele-competition and by measuring specific fitness components (i.e. life table and mating competition) to determine the costs of the different resistance mechanisms individually and in combination. We used four congenic A. aegypti strains: Rockefeller (ROCK) is susceptible to insecticides; KDR:ROCK (KR) contains only voltage-sensitive sodium channel (Vssc) mutations S989P+V1016G (kdr); CYP:ROCK (CR) contains only CYP-mediated resistance; and CYP+KDR:ROCK (CKR) contains both CYP-mediated resistance and kdr. The kdr allele frequency decreased over nine generations in the allele-competition study regardless of the presence of CYP-mediated resistance. Specific fitness costs were variable by strain and component measured. CR and CKR had a lower net reproductive rate (R0) than ROCK or KR, and KR was not different than ROCK. There was no correlation between the level of permethrin resistance conferred by the different mechanisms and their fitness cost ratio. We also found that CKR males had a reduced mating success relative to ROCK males when attempting to mate with ROCK females.

Conclusions/Significance

Both kdr and CYP-mediated resistance have a fitness cost affecting different physiological aspects of the mosquito. CYP-mediated resistance negatively affected adult longevity and mating competition, whereas the specific fitness costs of kdr remains elusive. Understanding fitness costs helps us determine whether and how quickly resistance will be lost after pesticide application has ceased.
Chagas disease screening in pregnant Latin American women: Adherence to a systematic screening protocol in a non-endemic country
Authors: Llenas-García Jara , Wikman-Jorgensen Philip , Gil-Anguita Concepción , Ramos- Sesma Violeta , Torrús-Tendero Diego , Martínez-Goñi Raquel , Romero-Nieto Mónica , García-Abellán Javier , Esteban-Giner María José , Antelo Karenina , Navarro-Cots María , Buñuel Fernando , Amador Concepción , García-García Josefa , Gascón Isabel , Telenti Guillermo , Fuentes-Campos Encarna , Torres Ignacio , Gimeno-Gascón Adelina , Ruíz-García María Montserrat , Navarro Miriam , Ramos-Rincón José-Manuel
Published: March 2021

Background

Chagas disease (CD) is a chronic parasitic disease caused by Trypanosoma cruzi and is endemic to continental Latin America. In Spain, the main transmission route is congenital. We aimed to assess adherence to regional recommendations of universal screening for CD during pregnancy in Latin American women in the province of Alicante from 2014 to 2018.

Methodology/Principal findings

Retrospective quality study using two data sources: 1) delivery records of Latin American women that gave birth in the 10 public hospitals of Alicante between January 2014 and December 2018; and 2) records of Chagas serologies carried out in those centers between May 2013 and December 2018. There were 3026 deliveries in Latin American women during the study period; 1178 (38.9%) underwent CD serology. Screening adherence ranged from 17.2% to 59.3% in the different health departments and was higher in Bolivian women (48.3%). Twenty-six deliveries (2.2%) had a positive screening; CD was confirmed in 23 (2%) deliveries of 21 women. Bolivians had the highest seroprevalence (21/112; 18.7%), followed by Colombians (1/333; 0.3%) and Ecuadorians (1/348; 0.3%). Of 21 CD-positive women (19 Bolivians, 1 Colombian, 1 Ecuadorian), infection was already known in 12 (57.1%), and 9 (42.9%) had already been treated. Only 1 of the 12 untreated women (8.3%) was treated postpartum. Follow-up started in 20 of the 23 (87.0%) neonates but was completed only in 11 (47.8%); no cases of congenital transmission were detected. Among the 1848 unscreened deliveries, we estimate 43 undiagnosed cases of CD and 1 to 2 undetected cases of congenital transmission.

Conclusions/Significance

Adherence to recommendations of systematic screening for CD in Latin American pregnant women in Alicante can be improved. Strategies to strengthen treatment of postpartum women and monitoring of exposed newborns are needed. Currently, there may be undetected cases of congenital transmission in our province.
Naegleria fowleri: Protein structures to facilitate drug discovery for the deadly, pathogenic free-living amoeba
Authors: Tillery Logan , Barrett Kayleigh , Goldstein Jenna , Lassner Jared W. , Osterhout Bram , Tran Nathan L. , Xu Lily , Young Ryan M. , Craig Justin , Chun Ian , Dranow David M. , Abendroth Jan , Delker Silvia L. , Davies Douglas R. , Mayclin Stephen J. , Calhoun Brandy , Bolejack Madison J. , Staker Bart , Subramanian Sandhya , Phan Isabelle , Lorimer Donald D. , Myler Peter J. , Edwards Thomas E. , Kyle Dennis E. , Rice Christopher A. , Morris James C. , Leahy James W. , Manetsch Roman , Barrett Lynn K. , Smith Craig L. , Van Voorhis Wesley C.
Published: March 2021

Naegleria fowleri is a pathogenic, thermophilic, free-living amoeba which causes primary amebic meningoencephalitis (PAM). Penetrating the olfactory mucosa, the brain-eating amoeba travels along the olfactory nerves, burrowing through the cribriform plate to its destination: the brain’s frontal lobes. The amoeba thrives in warm, freshwater environments, with peak infection rates in the summer months and has a mortality rate of approximately 97%. A major contributor to the pathogen’s high mortality is the lack of sensitivity of N. fowleri to current drug therapies, even in the face of combination-drug therapy. To enable rational drug discovery and design efforts we have pursued protein production and crystallography-based structure determination efforts for likely drug targets from N. fowleri. The genes were selected if they had homology to drug targets listed in Drug Bank or were nominated by primary investigators engaged in N. fowleri research. In 2017, 178 N. fowleri protein targets were queued to the Seattle Structural Genomics Center of Infectious Disease (SSGCID) pipeline, and to date 89 soluble recombinant proteins and 19 unique target structures have been produced. Many of the new protein structures are potential drug targets and contain structural differences compared to their human homologs, which could allow for the development of pathogen-specific inhibitors. Five of the structures were analyzed in more detail, and four of five show promise that selective inhibitors of the active site could be found. The 19 solved crystal structures build a foundation for future work in combating this devastating disease by encouraging further investigation to stimulate drug discovery for this neglected pathogen.
Genome-scale metabolic model of the diatom Thalassiosira pseudonana highlights the importance of nitrogen and sulfur metabolism in redox balance
Authors: van Tol Helena M. , Armbrust E. Virginia
Published: March 2021

Diatoms are unicellular photosynthetic algae known to secrete organic matter that fuels secondary production in the ocean, though our knowledge of how their physiology impacts the composition of dissolved organic matter remains limited. Like all photosynthetic organisms, their use of light for energy and reducing power creates the challenge of avoiding cellular damage. To better understand the interplay between redox balance and organic matter secretion, we reconstructed a genome-scale metabolic model of Thalassiosira pseudonana strain CCMP 1335, a model for diatom molecular biology and physiology, with a 60-year history of studies. The model simulates the metabolic activities of 1,432 genes via a network of 2,792 metabolites produced through 6,079 reactions distributed across six subcellular compartments. Growth was simulated under different steady-state light conditions (5–200 μmol photons m-2 s-1) and in a batch culture progressing from exponential growth to nitrate-limitation and nitrogen-starvation. We used the model to examine the dissipation of reductants generated through light-dependent processes and found that when available, nitrate assimilation is an important means of dissipating reductants in the plastid; under nitrate-limiting conditions, sulfate assimilation plays a similar role. The use of either nitrate or sulfate uptake to balance redox reactions leads to the secretion of distinct organic nitrogen and sulfur compounds. Such compounds can be accessed by bacteria in the surface ocean. The model of the diatom Thalassiosira pseudonana provides a mechanistic explanation for the production of ecologically and climatologically relevant compounds that may serve as the basis for intricate, cross-kingdom microbial networks. Diatom metabolism has an important influence on global biogeochemistry; metabolic models of marine microorganisms link genes to ecosystems and may be key to integrating molecular data with models of ocean biogeochemistry.
Choice of library preparation affects sequence quality, genome assembly, and precise in silico prediction of virulence genes in shiga toxin-producing Escherichia coli
Authors: Haendiges Julie , Jinneman Karen , Gonzalez-Escalona Narjol
Published: March 2021

Whole genome sequencing (WGS) provides essential public health information and is used worldwide for pathogen surveillance, epidemiology, and source tracking. Foodborne pathogens are often sequenced using rapid library preparation chemistries based on transposon technology; however, this method may miss random segments of genomes that can be important for accurate downstream analyses. As new technologies become available, it may become possible to achieve better overall coverage. Here we compare the sequence quality obtained using libraries prepared from the Nextera XT and Nextera DNA Prep (Illumina, San Diego, CA) chemistries for 31 Shiga toxin-producingEscherichia coli(STEC) O121:H19 strains, which had been isolated from flour during a 2016 outbreak. The Nextera DNA Prep gave superior performance metrics including sequence quality, assembly quality, uniformity of genome coverage, and virulence gene identification, among other metrics. Comprehensive detection of virulence genes is essential for making educated assessments of STECs virulence potential. The phylogenetic SNP analysis did not show any differences in the variants detected by either library preparation method which allows isolates prepared from either library method to be analysed together. Our comprehensive comparison of these chemistries should assist researchers wishing to improve their sequencing workflow for STECs and other genomic risk assessments.
Evaluating a large-scale online behaviour change intervention aimed at wildlife product consumers in Singapore
Authors: Doughty Hunter , Milner-Gulland E. J. , Lee Janice Ser Huay , Oliver Kathryn , Carrasco L. Roman , Veríssimo Diogo
Published: March 2021

Interventions to shift the behaviour of consumers using unsustainable wildlife products are key to threatened species conservation. Whether these interventions are effective is largely unknown due to a dearth of detailed evaluations. We previously conducted a country-level online behaviour change intervention targeting consumers of the Critically Endangered saiga antelope (Saiga tatarica) horn in Singapore. To evaluate intervention impact, we carried out in-person consumer surveys with >2,000 individuals pre- and post-intervention (2017 and 2019), and 93 in-person post-intervention surveys with traditional Chinese medicine (TCM) shopkeepers (2019). The proportion of self-reported high-usage saiga horn consumers in the target audience (Chinese Singaporean women aged 35–59) did not change significantly from pre- to post-intervention (24.4% versus 22.6%). However, post-intervention the target audience was significantly more likely than the non-target audience to accurately recall the intervention message and to report a decrease in saiga horn usage (4% versus 1% reported a behaviour change). Within the target audience, high-usage consumers were significantly more likely than lower-usage consumers to recall the message and report a behaviour change. Across respondents who reported a decrease in saiga horn usage, they cited the intervention message as a specific reason for their behaviour change significantly more than other reasons. Additionally, across all respondents, the belief that saiga is a common species in the wild decreased significantly from pre- to post-intervention. TCM shopkeepers, however, cited factors such as price and availability as the strongest influences on saiga horn sales. In sum, the intervention did significantly influence some consumers but the reduction of high-usage consumer frequency was not significant at the population level. We explore reasons for these findings, including competing consumer influences, characteristics of the intervention, and evaluation timing. This work suggests our intervention approach has potential, and exemplifies a multi-pronged in-person evaluation of an online wildlife trade consumer intervention.
Australian voters’ attitudes to climate action and their social-political determinants
Authors: Colvin R. M. , Jotzo Frank
Published: March 2021

Australia is a relative laggard on climate policy, amidst social and political fractures despite rising support for climate policy in opinion polls. In the 2019 Australian federal election, which was dubbed the ‘climate election’, the opposition campaigned on comparatively ambitious climate action but the government was returned on a status quo policy. We explore the social-political determinants of climate attitudes and how they are positioned in relation to voting behaviour, in the context of the 2019 election. We use a large nationally representative survey of Australian voters (n = 2,033), and employ univariate and multivariate ordinal logistic regression models to uncover correlates. We find that a large majority of voters think it is important for Australia to reduce greenhouse gas emissions. However, the importance given to emissions reductions is sharply divided along lines of political party preference. Holding pro-climate action attitudes consistently correlates with voting for progressive political parties and having higher levels of education. We also find a strong age cohort divide, with younger people holding stronger pro-climate attitudes than older people, raising the question whether we are seeing the emergence of a new generation expressing strong pro-climate action and progressive political attitudes that will persist over time. We conduct population ageing scenarios to project changes to public opinion, by age group, into the future. These indicate that strong support for climate action would increase by about four percentage points over the coming decade as younger voters replace the old, if attitudes within cohorts remained fixed. We conclude that while cleavages in climate attitudes in Australia are set to continue, efforts to promote climate delay are bound to have a limited shelf life as a growing majority of voters accepts the need for climate action.
Experiences of receiving and providing maternity care during the COVID-19 pandemic in Australia: A five-cohort cross-sectional comparison
Authors: Bradfield Zoe , Wynter Karen , Hauck Yvonne , Vasilevski Vidanka , Kuliukas Lesley , Wilson Alyce N. , Szabo Rebecca A. , Homer Caroline S. E. , Sweet Linda
Published: March 2021

Introduction

The global COVID-19 pandemic has radically changed the way health care is delivered in many countries around the world. Evidence on the experience of those receiving or providing maternity care is important to guide practice through this challenging time.

Methods

A cross-sectional study was conducted in Australia. Five key stakeholder cohorts were included to explore and compare the experiences of those receiving or providing care during the COVID-19 pandemic. Women, their partners, midwives, medical practitioners and midwifery students who had received or provided maternity care from March 2020 onwards in Australia were recruited via social media and invited to participate in an online survey released between 13th May and 24th June 2020; a total of 3701 completed responses were received.

Findings

While anxiety related to COVID-19 was high among all five cohorts, there were statistically significant differences between the responses from each cohort for most survey items. Women were more likely to indicate concern about their own and family’s health and safety in relation to COVID-19 whereas midwives, doctors and midwifery students were more likely to be concerned about occupational exposure to COVID-19 through working in a health setting than those receiving care through attending these environments. Midwifery students and women’s partners were more likely to respond that they felt isolated because of the changes to the way care was provided. Despite concerns about care received or provided not meeting expectations, most respondents were satisfied with the quality of care provided, although midwives and midwifery students were less likely to agree.

Conclusion

This paper provides a unique exploration and comparison of experiences of receiving and providing maternity care during the COVID-19 pandemic in Australia. Findings are useful to support further service changes and future service redesign. New evidence provided offers unique insight into key stakeholders’ experiences of the rapid changes to health services.
School-based relationships and problematic internet use amongst Chinese students
Authors: Hayixibayi Alimila , Strodl Esben , Chen Wei-Qing , Kelly Adrian B.
Published: March 2021

The potential for adolescent mental health problems arising from heavy internet use is significant. There is a need to better understand the risk and protective factors related to problematic internet use (PIU) amongst adolescents. This study examined the role of adolescents’ perceptions of school-based relationships as potential contextual antecedents to problematic internet use. Specifically, 6552 adolescent students (55.9% boys, 13.51 ± 2. 93 years) from 22 primary and middle schools in southern China completed questionnaires to measure the degree of adolescent conflict with peers, teachers and other staff, school connectedness, perceived classroom atmosphere and problematic internet use. Self-reported data was collected using a two-level stratified sampling. Multiple regression analyses showed that conflict with peers and teachers was positively associated with higher levels of PIU, while school connectedness and perceived classroom atmosphere were negatively associated with PIU. An interaction effect was found for conflict with peers and grade level, such that the association between conflict with peers and PIU was stronger for secondary students compared to primary school students. The results support the need for school-based interventions for PIU to include a focus on conflict with peers and teachers, and for a focus on the enhancement of school connectedness and classroom atmosphere.
Willingness to pay for cataract surgery and associated factors among cataract patients in Outreach Site, North West Ethiopia
Authors: Seid Mohammed , Minyihun Amare , Tilahun Gizachew , Atnafu Asmamaw , Amare Getasew
Published: March 2021

Introduction

In Ethiopia, cataract surgery is mainly provided by donors free of charge through outreach programs. Assessing willingness to pay for patients for cataract surgery will help explain how the service is valued by the beneficiaries and design a domestic source of finance to sustain a program. Although knowledge concerning willingness to pay for cataract surgery is substantive for developing a cost-recovery model, the existed knowledge is limited and not well-addressed. Therefore, the study aimed to assess willingness to pay for cataract surgery and associated factors among cataract patients in Outreach Site, North West Ethiopia.

Methods

A cross-sectional outreach-based study was conducted on 827 cataract patients selected through a simple random sampling method in Tebebe Gion Specialized Hospital, North West Ethiopia, from 10/11/2018 to 14/11/2018. The data were collected using a contingent valuation elicitation approach to elicit the participants’ maximum willingness to pay through face to face questionnaire interviews. The descriptive data were organized and presented using summary statistics, frequency distribution tables, and figures accordingly. Factors assumed to be associate with a willingness to pay were identified using a Tobit regression model with a p-value of <0.05 and confidence interval (CI ≠ 0).

Results

The study involved 827 cataract patients, and their median age was 65years. About 55% of the participants were willing to pay for the surgery. The average amount of money willing to pay was 17.5USD (95% CI; 10.5, 35.00) and It was significantly associated with being still worker (β = 26.66, 95% CI: 13.03, 40.29), being educated (β = 29.16, 95% CI: 2.35, 55.97), free from ocular morbidity (β = 28.48, 95% CI: 1.08, 55.90), duration with the condition, (β = -1.69, 95% CI: -3.32, -0.07), admission laterality (β = 21.21, 95% CI: 3.65, 38.77) and remained visual ability (β = -0.29, 95% CI (-0.55, -0.04).

Conclusions

Participants’ willingness to pay for cataract surgery in outreach Sites is much lower than the surgery’s actual cost. Early intervention and developing a cost-recovery model with multi-tiered packages attributed to the neediest people as in retired, less educated, severely disabled is strategic to increase the demand for service uptake and service accessibility.
Graph-based ahead monitoring of vulnerabilities in large dynamic transportation networks
Authors: Furno Angelo , Faouzi Nour-Eddin El , Sharma Rajesh , Zimeo Eugenio
Published: March 2021

Betweenness Centrality (BC) has proven to be a fundamental metric in many domains to identify the components (nodes) of a system modelled as a graph that are mostly traversed by information flows thus being critical to the proper functioning of the system itself. In the transportation domain, the metric has been mainly adopted to discover topological bottlenecks of the physical infrastructure composed of roads or railways. The adoption of this metric to study the evolution of transportation networks that take into account also the dynamic conditions of traffic is in its infancy mainly due to the high computation time needed to compute BC in large dynamic graphs. This paper explores the adoption of dynamic BC,i.e.,BC computed on dynamic large-scale graphs, modeling road networks and the related vehicular traffic, and proposes the adoption of a fast algorithm for ahead monitoring of transportation networks by computing approximated BC values under time constraints. The experimental analysis proves that, with a bounded and tolerable approximation, the algorithm computes BC on very large dynamically weighted graphs in a significantly shorter time if compared with exact computation. Moreover, since the proposed algorithm can be tuned for an ideal trade-off between performance and accuracy, our solution paves the way to quasi real-time monitoring of highly dynamic networks providing anticipated information about possible congested or vulnerable areas. Such knowledge can be exploited by travel assistance services or intelligent traffic control systems to perform informed re-routing and therefore enhance network resilience in smart cities.
Baseline clinical characteristics and prognostic factors in hospitalized COVID-19 patients aged ≤ 65 years: A retrospective observational study
Authors: Betti Marta , Bertolotti Marinella , Ferrante Daniela , Roveta Annalisa , Pelazza Carolina , Giacchero Fabio , Penpa Serena , Massarino Costanza , Bolgeo Tatiana , Cassinari Antonella , Mussa Marco , Chichino Guido , Maconi Antonio
Published: March 2021

Background

Individual differences in susceptibility to SARS-CoV-2 infection, symptomatology and clinical manifestation of COVID-19 have thus far been observed but little is known about the prognostic factors of young patients.

Methods

A retrospective observational study was conducted on 171 patients aged ≤ 65 years hospitalized in Alessandria’s Hospital from 1st March to 30th April 2020 with laboratory confirmed COVID-19. Epidemiological data, symptoms at onset, clinical manifestations, Charlson Comorbidity Index, laboratory parameters, radiological findings and complications were considered. Patients were divided into two groups on the basis of COVID-19 severity. Multivariable logistic regression analysis was used to establish factors associated with the development of a moderate or severe disease.

Findings

A total of 171 patients (89 with mild/moderate disease, 82 with severe/critical disease), of which 61% males and a mean age (± SD) of 53.6 (± 9.7) were included. The multivariable logistic model identified age (50–65 vs 18–49; OR = 3.23 CI95% 1.42–7.37), platelet count (per 100 units of increase OR = 0.61 CI95% 0.42–0.89), c-reactive protein (CPR) (per unit of increase OR = 1.12 CI95% 1.06–1.20) as risk factors for severe or critical disease. The multivariable logistic model showed a good discriminating capacity with a C-index value of 0.76.

Interpretation

Patients aged ≥ 50 years with low platelet count and high CRP are more likely to develop severe or critical illness. These findings might contribute to improved clinical management.
Improved detection of air trapping on expiratory computed tomography using deep learning
Authors: Ram Sundaresh , Hoff Benjamin A. , Bell Alexander J. , Galban Stefanie , Fortuna Aleksa B. , Weinheimer Oliver , Wielpütz Mark O. , Robinson Terry E. , Newman Beverley , Vummidi Dharshan , Chughtai Aamer , Kazerooni Ella A. , Johnson Timothy D. , Han MeiLan K. , Hatt Charles R. , Galban Craig J.
Published: March 2021

Background

Radiologic evidence of air trapping (AT) on expiratory computed tomography (CT) scans is associated with early pulmonary dysfunction in patients with cystic fibrosis (CF). However, standard techniques for quantitative assessment of AT are highly variable, resulting in limited efficacy for monitoring disease progression.

Objective

To investigate the effectiveness of a convolutional neural network (CNN) model for quantifying and monitoring AT, and to compare it with other quantitative AT measures obtained from threshold-based techniques.

Materials and methods

Paired volumetric whole lung inspiratory and expiratory CT scans were obtained at four time points (0, 3, 12 and 24 months) on 36 subjects with mild CF lung disease. A densely connected CNN (DN) was trained using AT segmentation maps generated from a personalized threshold-based method (PTM). Quantitative AT (QAT) values, presented as the relative volume of AT over the lungs, from the DN approach were compared to QAT values from the PTM method. Radiographic assessment, spirometric measures, and clinical scores were correlated to the DN QAT values using a linear mixed effects model.

Results

QAT values from the DN were found to increase from 8.65% ± 1.38% to 21.38% ± 1.82%, respectively, over a two-year period. Comparison of CNN model results to intensity-based measures demonstrated a systematic drop in the Dice coefficient over time (decreased from 0.86 ± 0.03 to 0.45 ± 0.04). The trends observed in DN QAT values were consistent with clinical scores for AT, bronchiectasis, and mucus plugging. In addition, the DN approach was found to be less susceptible to variations in expiratory deflation levels than the threshold-based approach.

Conclusion

The CNN model effectively delineated AT on expiratory CT scans, which provides an automated and objective approach for assessing and monitoring AT in CF patients.