bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial genome wide association study substantiatespapGIIofEscherichia colias a patient independent driver of urosepsis
Authors: Cuénod Aline , Agnetti Jessica , Seth-Smith Helena , Roloff Tim , Wälchli Denise , Scherbakov Dimitri , Akbergenov Rashid , Tschudin-Sutter Sarah , Bassetti Stefano , Siegemund Martin , Nickel Christian H. , Moran-Gilad Jacob , Keys Timothy G. , Pflüger Valentin , Thomson Nicholas R. , Egli Adrian
Published: May 2023

Urinary tract infections are extremely common and often caused byEscherichia coli. Bacterial virulence factors and patient characteristics have been linked separately to progressive, invasive infection. The interaction of these factors has however rarely been considered. We whole genome sequenced 1076E. coliisolates recovered from urine-or blood culture samples from 825 clinical cases. The majority of isolates belonged to the phylogroups B2 and D and encoded polysaccharide capsules. In line with previous studies, our bGWAS identifiedpapGIIto be associated with bacteraemia. In a generalised linear model correcting for patient characteristics,papGIIwas substantiated as a major contributor to invasive infection. Further, an independent cohort of 1,657 urine samples was PCR screened forpapGIIcarryingE. coli, confirming the increased relative frequency ofpapGII+ strains to cause invasive infection. This study builds on previous work linkingpapGIIwith invasive infection by showing that it is a patient-independent risk factor that has diagnostic potential.
Comparative analysis of symptom profile and risk of death associated with infection by SARS-CoV-2 and its variants in Hong Kong
Authors: Kwok Kin On , Wei Wan In , Mcneil Edward B. , Tang Arthur , Tang Julian Wei Tze , Wong Samuel Yeung Shan , Yeoh Eng Kiong
Published: May 2023

Introduction

The recurrent multi-wave nature of COVID-19 necessitates updating its symptomatology. Before the omicron era, Hong Kong was relatively unscathed and had a low vaccine uptake rate among the old-old, giving us an opportunity to study the intrinsic severity of SARS-CoV-2 variants. A comparison of symptom patterns across variants and vaccination status in Hong Kong has yet to be undertaken. The intrinsic severity of variants and symptoms predictive of severe outcomes are also understudied as COVID-19 evolves. We therefore aim to characterize the effect of variants on symptom presentation, identify the symptoms predictive and protective of death, and quantify the effect of vaccination on symptom development.

Methods

With the COVID-19 case series in Hong Kong from inception to 25 August 2022, an iterative multi-tier text-matching algorithm was developed to identify symptoms from free text. Cases were fully vaccinated if they completed two doses. Multivariate regression was used to measure associations between variants, symptom development, death and vaccination status. A least absolute shrinkage and selection operator technique was used to identify a parsimonious set of symptoms jointly associated with death.

Results

Overall, 70.9% (54450/76762) of cases were symptomatic. We identified a wide spectrum of symptoms (n=102), with cough, fever, runny nose and sore throat being the most common (8.16-47.0%). Intrinsically, the wild-type and delta variant caused similar symptoms, with runny nose, sore throat, itchy throat and headache more frequent in the delta cohort; whereas symptoms were heterogeneous between the wild-type and omicron variant, with seven symptoms (fatigue, fever, chest pain, runny nose, sputum production, nausea/vomiting and sore throat) more frequent in the omicron cohort. With full vaccination, omicron was still more likely than delta to cause fever. Fever, blocked nose and shortness of breath were robustly jointly predictive of death as the virus evolved. Number of vaccine doses required for reduction in occurrence varied by symptoms.

Discussion

This is the first large-scale study to evaluate the changing symptomatology by COVID-19 variants and vaccination status using free-text reporting by patients. We substantiate existing findings that omicron has a different clinical presentation compared to previous variants. Syndromic surveillance can be bettered with reduced reliance on symptom-based case identification, increased weighing on symptoms robustly predictive of mortality in outcome prediction, strengthened infection control in care homes through universal individual-based risk assessment to enable early risk stratification, adjusting the stockpile of medicine to tally with the changing symptom profiles across vaccine doses, and incorporating free-text symptom reporting by patients.
The distribution of global tidal marshes from earth observation data
Authors: Worthington Thomas A. , Spalding Mark , Landis Emily , Maxwell Tania L. , Navarro Alejandro , Smart Lindsey S. , Murray Nicholas J.
Published: May 2023

Aim

Tidal marsh ecosystems are heavily impacted by human activities, highlighting a pressing need to address gaps in our knowledge of their distribution. To better understand the global distribution and changes in tidal marsh extent, and identify opportunities for their conservation and restoration, it is critical to develop a spatial knowledge base of their global occurrence. Here, we develop a globally consistent tidal marsh distribution map for the year 2020 at 10-m resolution.

Location

Global

Time period

2020

Major taxa studied

Tidal marshes

Methods

To map the location of the world’s tidal marshes we applied a random forest classification model to earth observation data from the year 2020. We trained the classification model with a reference dataset developed to support distribution mapping of coastal ecosystems, and predicted the spatial distribution of tidal marshes between 60°N to 60°S. We validated the tidal marsh map using standard accuracy assessment methods, with our final map having an overall accuracy score of 0.852.

Results

We estimate the global extent of tidal marshes in 2020 to be 52,880 km2(95% CI: 32,030 to 59,780 km2) distributed across 120 countries and territories. Tidal marsh distribution is centred in temperate and Arctic regions, with nearly half of the global extent of tidal marshes occurring in the temperate Northern Atlantic (45%) region. At the national scale, over a third of the global extent (18,510 km2; CI: 11,200 – 20,900) occurs within the USA.

Main conclusions

Our analysis provides the most detailed spatial data on global tidal marsh distribution to date and shows that tidal marshes occur in more countries and across a greater proportion of the world’s coastline than previous mapping studies. Our map fills a major knowledge gap regarding the distribution of the world’s coastal ecosystems and provides the baseline needed for measuring changes in tidal marsh extent and estimating their value in terms of ecosystem services
A predatory gastrula leads to symbiosis-independent settlement inAiptasia
Authors: Maegele Ira , Rupp Sebastian , Özbek Suat , Guse Annika , Hambleton Elizabeth A. , Holstein Thomas W.
Published: May 2023

The planulae larvae of cnidarians (jellyfish, hydras, anemones, corals) have attracted interest since Haeckels 150-year-old postulation of the gastrula developmental stage of sponges and corals as the terminal lifeform of primitive multicellular metazoans. Widely viewed as primarily particle feeders, the planulae larvae of the anemone Exaiptasia pallida (commonly Aiptasia) have not been reported to undergo settlement and metamorphosis to adult morphology, and the lack of a closed lifecycle has been a major obstacle in this increasingly popular model system for coral-dinoflagellate endosymbiosis. Here we studied Aiptasia larvae feeding behavior and show its indispensability to trigger the first reports of settlement and metamorphosis in the system, finally closing the Aiptasia lifecycle. Surprisingly, the young gastrula-like planulae at just two days post fertilization actively feed on living crustacean nauplii, preferentially to heat-killed ones. Predation is dependent on functional stinging cells (nematocytes), indicative of complex neuronal control. Larvae fed daily dramatically increase in size and at 14 days post fertilization begin to morphologically change prior to settlement at high efficiency. Strikingly, dinoflagellate endosymbionts are neither required for larval growth nor measurably affect settlement dynamics, but are essential for spawning of the mature adult polyps. Our data show for the first time that gastrula-like planulae were capable of prey capture, suggesting carnivory in addition to filter feeding as a common strategy of this terminal life form. These data are discussed in the context of recent revelations on the evolution of basal metazoans.
Hypoxia Bi-directionally Regulates Gut Vascular Barrier through HIF-1α-dependent Mechanismin vitro
Authors: Liu Ping , Dai Wen , Du Jing , Zhou Yingshan , Wang Xiaodu , Song Houhui
Published: May 2023

Objective

The gut vascular barrier (GVB) is the key checkpoint for pathogens to enter the blood circulation through the intestine, which is crucial for maintaining the intestinal barrier function. However, the effect and molecular mechanism of hypoxia on GVB remains unclear. Here, we show a role of the transcription factor hypoxia inducible factor-1α (HIF-1α) in hypoxia-induced bi-directional regulation of GVB.

Approach and Results

Anin vitroGVB model composed of rat intestinal microvascular endothelial cells was studied. Evans blue-albumin efflux assay showed that the experimentally severe hypoxia induced by cobalt chloride (500 μM, 24 h) markedly disrupted the GVBin vitro, while mild hypoxia induced by cobalt chloride (500 μM, 6 h) evidently enhanced the GVB, revealing hypoxia-induced bi-directional regulation of the GVB for the first-time. Importantly, knockdown of HIF-1α largely abolished the bi-directional changes of GVB caused by hypoxia. Furthermore, experimentally severe hypoxia exacerbated the inflammatory GVB disruption induced by LPS or TNF-α, while the mild hypoxia promoted the repair.

Conclusion

Collectively, our data indicate that hypoxia bi-directionally regulates GVB in a HIF-1α-dependent manner.
Adaptation at the edge: Patterns of local adaptation and genetic variation during a contemporary range expansion
Authors: Clark Eliza I. , Bean Dan W. , Bitume Ellyn V. , Stahlke Amanda R. , Hohenlohe Paul A. , Hufbauer Ruth A.
Published: May 2023

During range expansion, differences can evolve between populations at the core and expanding edge of a range. While theory and experimental work has focused on range expansions across uniform environments, natural range expansions often occur over environmental gradients, which present novel selection pressures. We seek to understand how genetic variation expressed in different environments may constrain adaptation during range expansion across environmental gradients, by testing whether long-established populations are better adapted to their local environments than newly established populations in the expanding edge. We study the timing of winter dormancy in a beetle introduced for biological control (Diorhabda carinulata), expanding from areas with cold winters to areas with milder, shorter winters. In a reciprocal environment experiment, core populations showed a pattern of local adaptation, but only some edge populations showed a similar pattern, indicating these populations vary in their degree of adaptation. Expressed genetic variation of dormancy timing in a core population was high in a local (core) environment but disappeared in a novel (edge) environment. These results show that adaptive evolution has been rapid, likely fueled by high heritability, but long-distance movement may hinder adaptation by reducing the heritable genetic variation on which selection can act.
A turning point in COVID-19 severity and fatality during the pandemic: A national cohort study in Qatar
Authors: Chemaitelly Hiam , Ayoub Houssein H. , Faust Jeremy Samuel , Coyle Peter , Tang Patrick , Hasan Mohammad R. , Yassine Hadi M. , Al-Khatib Hebah A. , Al Thani Asmaa A. , Al-Kanaani Zaina , Al-Kuwari Einas , Jeremijenko Andrew , Kaleeckal Anvar Hassan , Latif Ali Nizar , Shaik Riyazuddin Mohammad , Abdul-Rahim Hanan F. , Nasrallah Gheyath K. , Al-Kuwari Mohamed Ghaith , Butt Adeel A. , Al-Romaihi Hamad Eid , Al-Thani Mohamed H. , Al-Khal Abdullatif , Bertollini Roberto , Abu-Raddad Laith J.
Published: May 2023

Background

This study assessed the evolution of COVID-19 severity and fatality by utilizing rigorous and standardized criteria that were consistently applied throughout the pandemic in Qatar.

Methods

A national cohort study was conducted on Qataris, using data on COVID-19 acute-care and ICU hospitalizations, as well as severe, critical, and fatal COVID-19 cases classified according to the World Health Organization criteria.

Results

The cumulative incidence of severe, critical, or fatal COVID-19 after 3.14 years of follow-up was 0.45% (95% CI: 0.43-0.47%). The incidence rate for severe, critical, or fatal COVID-19 throughout the pandemic was 1.43 (95% CI: 1.35-1.50) per 1,000 person-years. In the pre-omicron phase, first omicron wave, and combined phases, it was 2.01 (95% CI: 1.90-2.13), 3.70 (95% CI: 3.25-4.22), and 2.18 (95% CI: 2.07-2.30) per 1,000 person-years, respectively. The post-first omicron phase saw a drastic drop to 0.10 (95% CI: 0.08-0.14) per 1,000 person-years, a 95.4% reduction. Among all severe, critical, and fatal cases, 99.5% occurred during the primary infection. The cumulative incidence of fatal COVID-19 was 0.042% (95% CI: 0.036-0.050%), with an incidence rate of 0.13 (95% CI: 0.11-0.16) per 1,000 person-years. In the post-first omicron phase, the incidence rate of fatal COVID-19 decreased by 90.0% compared to earlier stages. Both severity and fatality exhibited an exponential increase with age and a linear increase with the number of coexisting conditions.

Conclusions

The conclusion of the first omicron wave was a turning point in the severity of the pandemic. While vaccination and enhanced case management reduced severity gradually, the rapid accumulation of natural immunity during the initial omicron wave appears to have played the crucial role in driving this shift in severity.
Mobile-linked point-of-care diagnostics in community-based healthcare: A scoping review of user experiences
Authors: Nxele Siphesihle R. , Moetlhoa Boitumelo , Dlangalala Thobeka , Maluleke Kuhlula , Kgarosi Kabelo , Theberge Ashleigh B. , Mashamba-Thompson Tivani
Published: May 2023

Background

While mobile-linked point-of-care diagnostics may circumvent geographical and temporal barriers to efficient communication, the use of such technology in community settings will depend on user experience. We conducted a scoping review to systematically map evidence on user experiences of mobile-linked point-of-care diagnostics in community healthcare settings.

Methodology

We conducted a comprehensive search of the following electronic databases: Scopus, Web of Science, and EBSCOhost (Medline, CINAHL, Africa-wide, Academic Search Complete). The inter-reviewer agreement was determined using Cohen’s kappa statistic. Data quality was appraised using the mixed method appraisal tool version 2018, and the results were reported according to the preferred reporting items for systematic reviews and meta-analyses for scoping reviews (PRISMA-ScR).

Results

Following the abstract and full article screening, nine articles were found eligible for inclusion in data extraction. Following the quality appraisal, one study scored 72.5%, one study scored 95%, and the remaining seven studies scored 100%. Inter-rater agreement was 83.54% (Kappa statistic = 0.51, p < 0.05). Three themes emerged from the articles: approaches to implementing mobile-linked point-of-care diagnostics, user engagement in community-based healthcare settings, and limited user experiences in mobile-linked point-of-care diagnostics. User experiences are key to the sustainable implementation of mobile-linked point-of-care diagnostics. User experiences have been evaluated in small community healthcare settings. There is limited evidence of research aimed at evaluating the usability of mobile-linked diagnostics at the community level.

Conclusion

More studies are needed to assess the user experience of mobile-linked diagnostics in larger communities. This scoping review revealed gaps that need to be addressed to improve user experiences of mobile-linked diagnostics, including language barriers, privacy issues, and clear instructions.
Balancing Memorization and Generalization in RNNs for High Performance Brain-Machine Interfaces
Authors: Costello Joseph T. , Temmar Hisham , Cubillos Luis H. , Mender Matthew J. , Wallace Dylan M. , Willsey Matthew S. , Patil Parag G. , Chestek Cynthia A.
Published: May 2023

Brain-machine interfaces (BMIs) can restore motor function to people with paralysis but are currently limited by the accuracy of real-time decoding algorithms. Recurrent neural networks (RNNs) using modern training techniques have shown promise in accurately predicting movements from neural signals but have yet to be rigorously evaluated against other decoding algorithms in a closed-loop setting. Here we compared RNNs to other neural network architectures in real-time, continuous decoding of finger movements using intracortical signals from nonhuman primates. Across one and two finger online tasks, LSTMs (a type of RNN) outperformed convolutional and transformer-based neural networks, averaging 18% higher throughput than the convolution network. On simplified tasks with a reduced movement set, RNN decoders were allowed to memorize movement patterns and matched able-bodied control. Performance gradually dropped as the number of distinct movements increased but did not go below fully continuous decoder performance. Finally, in a two-finger task where one degree-of-freedom had poor input signals, we recovered functional control using RNNs trained to act both like a movement classifier and continuous decoder. Our results suggest that RNNs can enable functional real-time BMI control by learning and generating accurate movement patterns.
Enhanced specificity ofBacillusmetataxonomics using atuf-targeted amplicon sequencing approach
Authors: Xu Xinming , Nielsen Lasse Johan Dyrbye , Song Lijie , Maróti Gergely , Strube Mikael Lenz , Kovács Ákos T.
Published: May 2023

Bacillusspecies are ubiquitous in nature and have tremendous application potential in agriculture, medicine, and industry. However, the individual species of this genus vary widely in both ecological niches and functional phenotypes, which, hence, requires accurate classification of these bacteria when selecting them for specific purposes. Although analysis of the 16S gene has been widely used to disseminate the taxonomy of most bacterial species, this gene fails proper classification ofBacillusspecies. To circumvent this restriction, we designed novel primers and optimized them to allow exact species resolution ofBacillusspecies in both synthetic and natural communities using high-throughput amplicon sequencing. The primers designed for thetufgene were not only specific for theBacillusgenus but also sufficiently discriminated species bothin silicoandin vitroin a mixture of 11 distinctBacillusspecies. Investigating the primers using a natural soil sample, 13 dominant species were detected includingBacillus badius,Bacillus velezensis, andBacillus mycoidesas primary members, neither of which could be distinguished with 16S sequencing. In conclusion, a set of high-throughput primers were developed which allows unprecedented species-level identification ofBacillusspecies, including agriculturally important species.
Study of Glucometer Precision and Antimalarial Therapy Interference on Glucose Readings in Nigeria
Authors: Ugochukwu Ezinwanne Jane , Mosanaya Adaobi Uchenna , Nweze Victor Nnanna , Chukwu Marydith Ifeoma , Ubaka Chukwuemeka Michael , Alawami Mohammed
Published: May 2023

Malaria-infected diabetic (MID) patients have become one of the highest diabetic population with comorbidities in Nigeria. While the artemisinin-based combination therapy (ACT) are used for malaria treatment, glucometers are used to monitor their blood glucose levels. However, some drugs are known to interfere with the accuracy of glucose readings leading to misdiagnosis. In this study, we investigated the interferences of artemether and lumefantrine as well as other known drug interferents on the accuracy of glucose readings in three different glucometers commonly used in Nigeria(Accu-Answer®, VivaChek® and GlucoDr®). Blood sample was collected from a healthy volunteer, aliquots of the blood with pure samples of artemether and lumefantrinepowders as well as other known drug interferents were prepared in normal and low pools. The precision study on the glucometers were determined. We find that Accu-Answer®was the only precise glucometer considering its coefficient of variation. The influence of the artemether and lumefantrine was mild in two glucometers andthe predicted binding affinities showed possible binding interactions that may have caused their interferences.
The Genetic Landscape of a Metabolic Interaction
Authors: Nguyen Thuy N. , Ingle Christine , Thompson Samuel , Reynolds Kimberly A.
Published: May 2023

Enzyme abundance, catalytic activity, and ultimately sequence are all shaped by the need of growing cells to maintain metabolic flux while minimizing accumulation of deleterious intermediates. While much prior work has explored the constraints on protein sequence and evolution induced by physical protein-protein interactions, the sequence-level constraints emerging from non-binding functional interactions in metabolism remain unclear. To quantify how variation in the activity of one enzyme constrains the biochemical parameters and sequence of another, we focused on dihydrofolate reductase (DHFR) and thymidylate synthase (TYMS), a pair of enzymes catalyzing consecutive reactions in folate metabolism. We used deep mutational scanning to quantify the growth rate effect of 2,696 DHFR single mutations in 3 TYMS backgrounds under conditions selected to emphasize biochemical epistasis. Our data are well-described by a relatively simple enzyme velocity to growth rate model that quantifies how metabolic context tunes enzyme mutational tolerance. Together our results reveal the structural distribution of epistasis in a metabolic enzyme and establish a foundation for the design of multi-enzyme systems.
Tracking the Metabolic Fate of Exogenous Arachidonic Acid in Ferroptosis Using Dual-Isotope Labeling Lipidomics
Authors: Reimers Noelle , Do Quynh , Zhang Rutan , Guo Angela , Ostrander Ryan , Shoji Alyson , Vuong Chau , Xu Libin
Published: May 2023

Lipid metabolism is implicated in a variety of diseases, including cancer, cell death, and inflammation, but lipidomics has proven to be challenging due to the vast structural diversity over a narrow range of mass and polarity of lipids. Isotope labeling is often used in metabolomics studies to follow the metabolism of exogenously added labeled compounds because they can be differentiated from endogenous compounds by the mass shift associated with the label. The application of isotope labeling to lipidomics has also been explored as a method to track the metabolism of lipids in various disease states. However, it can be difficult to differentiate a single isotopically labeled lipid from the rest of the lipidome due to the variety of endogenous lipids present over the same mass range. Here we report the development of a dual-isotope deuterium labeling method to track the metabolic fate of exogenous polyunsaturated fatty acids, e.g, arachidonic acid (AA), in the context of ferroptosis using hydrophilic interaction-ion mobility-mass spectrometry (HILIC-IM-MS). Ferroptosis is a type of cell death that is dependent on lipid peroxidation. The use of two isotope labels rather than one enables the identification of labeled species by a signature doublet peak in the resulting mass spectra. A Python-based software, D-Tracer, was developed to efficiently extract metabolites with dual-isotope labels. The labeled species were then identified withLipydomicsbased on their retention times, collision cross section, andm/zvalues. Changes in exogenous AA incorporation in the absence and presence of a ferroptosis inducer were elucidated.

Table of Contents
α-Synuclein oligomers form by secondary nucleation
Authors: Xu Catherine K , Meisl Georg , Andrzejewska Ewa , Krainer Georg , Dear Alexander J , Cruz Marta Castellana , Turi Soma , Jacquat Raphael , Arter William E , Vendruscolo Michele , Linse Sara , Knowles Tuomas PJ
Published: May 2023

Oligomeric species arising during aggregation of α-synuclein are proposed to be a major source of toxicity in Parkinson’s disease, and thus a major potential drug target. However, their mechanism of formation and role in aggregation are largely unresolved. Here we first show that, at physiological pH, α-synuclein aggregates by secondary nucleation, rather than fragmentation, and that this process is enhanced by agitation. Moreover, using a combination of single molecule and bulk level techniques, we identify secondary nucleation on the surfaces of existing fibrils, rather than formation directly from monomers, as the dominant source of oligomers. Our results highlight secondary nucleation as not only the key source of oligomers, but also the main mechanism of aggregate formation, and show that these processes take place under physiologically relevant conditions.
Bioinformatic and fine-scale chromosomal mapping uncover the essence and evolution of eliminated chromosomes in the Japanese hagfish,Eptatretus burgeri, through repetitive DNA family analysis
Authors: Nagao Kohei , Tanaka Yoshiki , Kajitani Rei , Toyoda Atsushi , Itoh Takehiko , Kubota Souichirou , Goto Yuji
Published: May 2023

In the Japanese hagfish,Eptatretus burgeri, approximately 21% of the genomic DNA in germ cells (2n=52) consists of 16 chromosomes (eliminated [E]-chromosomes) that are eliminated from presumptive somatic cells (2n=36). To uncover the eliminated genome (E-genome), we have identified 16 eliminated repetitive DNA families from eight hagfish species, with 11 of these repeats being selectively amplified in the germline genome ofE. burgeri. Furthermore, we have demonstrated that six of these sequences, namely EEEb1–6, are exclusively localized on all 16 E-chromosomes. This has led to the hypothesis that the eight pairs of E-chromosomes are derived from one pair of ancestral chromosomes via multiple duplication events over a prolonged evolutionary period. NGS analysis has recently facilitated the re-assembly of two distinct draft genomes ofE. burgeri, derived from the testis and liver. This advancement allows for the prediction of not only nonrepetitive eliminated sequences but also over 100 repetitive and eliminated sequences, accomplished through K-mer-based analysis. In this study, we report four novel eliminated repetitive DNA sequences (designated as EEEb7–10) and confirm the relative chromosomal localization of all eliminated repeats (EEEb1–10) by fluorescencein situhybridization (FISH). With the exception of EEEb10, all sequences were exclusively detected on EEEb1-positive chromosomes. Surprisingly, EEEb10 was detected as an intense signal on EEEb1-positive chromosomes and as a scattered signal on other chromosomes in germ cells. The study further divided the eight pairs of E-chromosomes into six groups based on the signal distribution of each DNA family, and fiber-FISH experiments showed that the EEEb2–10 family was dispersed in the EEEb1-positive extended chromatin fiber. These findings provide new insights into the mechanisms underlying chromosome elimination and the evolution of E-chromosomes, supporting our previous hypothesis.
Delay of human early development via in vitro diapause
Authors: Iyer Dhanur P. , Weijden Vera A. van der , Khoei Heidar Heidari , McCarthy Afshan , Rayon Teresa , Simon Claire S. , Dunkel Ilona , Wamaitha Sissy E. , Elder Kay , Snell Phil , Christie Leila , Schulz Edda G. , Niakan Kathy K. , Rivron Nicolas , Bulut-Karslioglu Aydan
Published: May 2023

Many mammals can control the timing of gestation and birth by pausing embryonic development at the blastocyst stage. It is unknown whether the capacity to pause development is conserved, in general across mammals, and more specifically in humans. Activity of the growth regulating mTOR pathway governs developmental pausing in the mouse (1). Here we show a stage-specific capacity to delay the progression of human development via mTOR inhibition. In this context, human blastoids and pluripotent stem cells in naïve and naïve-like, but not primed, states can be induced to enter a dormant state, which is reversible at the functional and molecular level. Comparative analysis of mouse and human naïve cells’ longitudinal response to mTORi revealed distinct temporal dynamics and metabolic requirements of dormancy in each species. Mouse and human blastocysts show similar tissue-specific patterns of mTOR pathway activity, suggesting that the mTOR pathway may be a conserved regulator of blastocyst development and timing in both species. Our results raise the possibility that the developmental timing of the human embryo may be controllable, with implications for reproductive therapies.
Cl--dependent amplification of excitatory synaptic potentials at distal dendrites revealed by voltage imaging
Authors: Morita Masato , Higashi Reo , Kawaguchi Shin-ya
Published: May 2023

Processing of synaptic signals in somatodendritic compartments determines the neuronal computation. Although amplification of excitatory signals by local voltage-dependent cation channels has been extensively studied, its spatio-temporal dynamics in elaborate dendritic branches remains obscure because of technical limitation. Using fluorescent voltage imaging throughout dendritic arborizations in hippocampal pyramidal neurons, here we demonstrate a unique Cl--dependent remote computation mechanism equipped in distal branches. Local laser photolysis of caged-glutamate triggered excitatory postsynaptic potentials spreading along dendrites with gradual amplification toward the distal end whereas with attenuation toward the soma.Tour-de-forcesubcellular patch-clamp recordings from thin branches complemented with biophysical model simulation revealed that the asymmetric augmentation of excitation relies on the TTX-resistant Na+channels and Cl--conductances accompanied with deeper dendritic resting potential. Taken together, the present study unveils cooperative voltage-dependent actions of cation and anion conductances for dendritic supralinear computation which can locally decode the spatio-temporal context of synaptic inputs.
Automatic carrier landing for UAV based on integrated disturbance observer and fault-tolerant control
Authors: Xue Yixuan , Zhen Ziyang , Zhang Zhibing , Cao Teng , Wan Tiancai
Published: May 2023

Purpose

Accurate glide path tracking is vital to the automatic carrier landing task of unmanned aerial vehicle (UAV). The purpose of this paper is to develop a reliable flight controller that can simultaneously deal with external disturbance, structure fault and actuator fault.

Design/methodology/approach

The automatic carrier landing task is resolved into the glide path tracking problem and attitude tracking problem. The disturbance observer-based adaptive sliding mode control scheme is proposed for system stabilization, disturbance rejection and fault tolerance.

Findings

Both the Lyapunov method and exemplary simulations can prove that the disturbance estimation error and the attitude tracking error converge in finite time in the presence of external disturbances and various faults.

Practical implications

The presented algorithm is testified by a UAV automatic carrier landing simulation, which shows the potential of practical usage.

Originality/value

The barrier function is introduced to adaptively update both the sliding mode observer gain and sliding mode controller gain, so that the sliding mode surface could converge to a predefined region without overestimation. The proposed flight controller ensures a secure carrier landing task.
Investigation of slanted perforation diameter in tabs for supersonic jet control
Authors: G. Ezhilmaran , S. Sekar , K. Sathish Kumar , S. Thanigaiarasu
Published: May 2023

Purpose

This study aims to investigate the effect of slanted perforation diameter in tabs for the control of Mach 1.4 underexpanded supersonic jet flow characteristics.

Design/methodology/approach

Numerical investigation was carried out for NPR 5 to analyze the effect of slanted perforation diameter in tabs to control the Mach 1.4 jet. Four sets of tabs with slanted circular perforation geometries (Φp = 1, 1.5, 2 and 2.5 mm) were considered in this study. The inclination angle of 20° (αP) with reference to the jet axis was maintained constant for all the four tabs considered.

Findings

Determined value indicates there is a 68%, 71%, 73% and 75% drop in supersonic core for the Φp = 1, 1.5, 2.0 and 2.5 mm, respectively. The results show that the tabs with 2.5 mm perforation diameter were found to be efficient in reducing the supersonic jet core in comparison with other tab cases. The reduction in supersonic core length is due to the extent of miniscule vortices exuviating from slanted small and large diameter perforation in the tabs.

Practical implications

The concept of slanted perforation can be applied in scramjet combustion, which finds its best application in hypersonic vehicles and in noise suppression in fighter aircraft.

Originality/value

Slanted perforation and circular shapes with different diameters have not been studied in the supersonic regime. Examining the effect of circular diameter in slanted perforation is an innovation in this research paper.
Enhancing ICT for female economic participation in sub-Saharan Africa
Authors: Asongu Simplice , Odhiambo Nicholas M.
Published: May 2023

Purpose

This study investigates how enhancing information and communication technology (ICT) affects female economic participation in sub-Saharan African nations.

Design/methodology/approach

Three female economic participation indicators are used, namely female labour force participation, female unemployment and female employment rates. The engaged ICT variables are fixed broadband subscriptions, mobile phone penetration and Internet penetration. The Generalized Method of Moments is used for the empirical analysis.

Findings

The following main findings are established: First, there is a (1) negative net effect in the relevance of fixed broadband subscriptions in female labour force participation and female unemployment and (2) positive net effects from the importance of fixed broadband subscriptions on the female employment rate. Secondly, an extended analysis is used to establish thresholds at which the undesirable net negative effect on female labour force participation can be avoided. From the corresponding findings, a fixed broadband subscription rate of 9.187 per 100 people is necessary to completely dampen the established net negative effect. Hence, the established threshold is the critical mass necessary for the enhancement of fixed broadband subscriptions to induce an overall positive net effect on the female labour force participation rate.

Originality/value

This study complements the extant literature by assessing how increasing penetration levels of ICT affect female economic inclusion and by extension, thresholds necessary for the promotion of ICT to increase female economic inclusion.
Bilingual teachers and young children co-constructing affect and play in translanguaging read-alouds
Authors: Beauchemin Faythe , Qin Kongji
Published: May 2023

Purpose

Affect is central to the process of teaching and learning. The recent affective turn in literacy education has further underscored its critical potential as an act of resistance against dehumanizing forces that impact students’ schooling and life experiences (Dutro, 2019; Leander and Ehret, 2019). This article, taking up the notion of affect as relational and performed forces that emerge from the in-betweenness among people, objects and material and discursive contexts, examines how two US Latinx teachers and their young bilingual students co-constructed affect and play in translanguaging read-alouds with a bilingual text that centered their culturally rooted ways of knowing and being.

Design/methodology/approach

Drawing on data from a larger practitioner research study that aimed at developing teacher candidates’ culturally and linguistically sustaining literacy instruction, the authors took a discourse analytic approach to examine how the two teachers created curricular opportunities for affect and play in designing the translanguaging read-alouds and how bilingual children and their teachers playfully engaged with the bilingual text during the read-alouds.

Findings

The analysis indicated that the teachers’ intentional selection of the Spanish–English bilingual picturebookNiño Wrestles the Worldcreated opportunities for the children to leverage their full linguistic repertoire and funds of knowledge to engage with the text. During the read-alouds, the children and the teachers co-constructed affect and playfulness through embodied performance and translanguaging.

Originality/value

This study contributes to the research and practice of literacy instruction of bilingual children by illustrating how affect figures into the process of literacy instruction and how translanguaging read-alouds can afford bilingual children opportunities to playfully engage with the text that centers their cultural epistemologies.
Familytakāfulpurchase intentions in Bangladesh: the mediating role of attitude and saving motives and the moderating role of religiosity
Authors: Hasan Abdulla Al-Towfiq , Rahman Md Takibur
Published: May 2023

Purpose

The purpose of this study is to predict family takāful purchase intentions (FTPIs) using an extended theory of planned behavior (TPB) with relevant mediating and moderating factors.

Design/methodology/approach

This study is based on a survey of 384 Muslim employees who work in both government and private organizations. This study used partial least square structural equation model (PLS-SEM) for hypothesis testing, predictive relevance and measuring the effect size of the model.

Findings

The study found that attitude (ATT), subjective norms (SN), perceived behavioral control (PBC), saving motives (SM), promotional campaign (PC) and religiosity (RG) directly contribute to the prediction of FTPIs. Furthermore, ATT and SM partially mediate between PC and FTPI. Moreover, RG significantly moderates the association between ATT, SN, SM and FTPI, while RG insignificantly moderates the link between PBC and FTPI.

Practical implications

This study provides insight into understanding the factors leading to an enhanced understanding of FTPI in a country where the industry is growing very fast. Further, the study suggests informative and persuasive promotions to encourage FTPI in Bangladesh and similar countries.

Originality/value

This study provides insights into previously unaddressed FTPI among Muslim employees in Bangladesh and similar countries. Prior work on determining FTPI has not focused on promotional campaigns and saving motives, and thus, this study has extended TPB to understand the phenomenon.
Deterioration of the subjective financial well-being during the coronavirus pandemic: a latent transition analysis
Authors: Losada-Otálora Mauricio , Peña-García Nathalie , Juliao-Rossi Jorge Luis
Published: May 2023

Purpose

The authors seek (1) to identify the profiles of subjective financial well-being (SFWB) of bank customers before and during the coronavirus disease 2019 (COVID-19) pandemic, (2) to analyze the transition to profiles of lower SFWB during the pandemic and (3) to identify the factors driving such transitions.

Design/methodology/approach

The authors surveyed five countries during 2019 and 2020 to measure SFWB. The authors applied latent class analysis (LCA) to identify profiles of bank customers according to a mix of SFWB indicators in pre-pandemic times (Study 1). The authors validated the profiles during the pandemic and identified the SFWB dimensions that deteriorated during the crisis (Study 2). Finally, the authors applied latent transition analysis (LTA) to explore transitions to profiles of lower SFWB and identify the drivers.

Findings

The authors identified three profiles of customers in pre- and post-pandemic periods for four dimensions of SFWB: control over finances, capacity to absorb financial shocks, ability to track financial goals and financial freedom. Gender, age, trust in banks and bank-supporting policies were related to transitions across profiles of SFWB during the pandemic. These relationships are contingent upon contextual country-related variables.

Research limitations/implications

Banks and policymakers should reduce customers' exposure to the pandemic's long-lasting adverse effects on SFWB and should identify and control the multiplier role that contextual variables play.

Originality/value

Extant literature has not fully identified the dimensions of SFWB that changed due to the COVID-19 pandemic. The authors narrow this gap by identifying three SFWB profiles of customers, analyzing the patterns of SFWB change and connecting these changes to individual, provider and contextual factors.
Optimization of a photovoltaic system: a case study Kosovo
Authors: Bylykbashi Blerina , Filkoski Risto Vasil
Published: May 2023

Purpose

The purpose of this study is optimization of existing PV system and by making the optimization to reach the heights energy performance from the system.

Design/methodology/approach

The methodology used in this work is analytical as well as software using PV*SOL premium software. Both methods are used to achieve a more realistic analysis of the results achieved at the end of the work.

Findings

After analyzing the optimization of the PV system in terms of certain atmospheric conditions, it is clear that the optimization of the system is necessary. Through the optimization of the systems, a better performance of the system is achieved, as well as in the case in question, it affects the increase of the energy generated annually up to 500 kWh.

Originality/value

This work is the original work of the author, which represents a part of the topic of the doctorate.
Mandatory CSR disclosure and CEO pay performance sensitivity in China: evidence from a quasi-natural experiment
Authors: Song Siwen , Cheung Adrian (Wai Kong) , Jun Aelee , Ma Shiguang
Published: May 2023

Purpose

This paper aims to empirically examine the impact of mandatory CSR disclosure on the CEO pay performance sensitivity.

Design/methodology/approach

Using the mandatory requirement of CSR disclosure as an exogenous shock, the authors compare the changes in CEO pay performance sensitivity for treatment firms with control firms through a difference-in-difference (DiD) approach.

Findings

The authors find that mandatory CSR disclosure enhances CEO pay performance sensitivity. The results also show that monitoring CEO power is a conduit through which mandatory CSR disclosure affects CEO pay performance sensitivity. The positive impact is more profound in firms with a powerful CEO, i.e. one who is politically well-connected, holds dual roles as both CEO and Chairman, and/or has had a long tenure. Furthermore, the increased CEO pay performance sensitivity after the mandate is prominent among state-owned enterprises (SOEs) only.

Practical implications

The findings of this paper have implications for other economies with similar institutional backgrounds as China. Although the mandatory CSR disclosure does not require firms to spend on CSR investment, the mandatory CSR disclosure alters firm behaviour, and mitigates agency problems.

Originality/value

This paper contributes to the studies on the impact of CSR disclosure on firms' behaviour. To the authors' knowledge, this is the first study to examine the effects of mandatory CSR disclosure on CEO pay performance sensitivity using the quasi-natural experiment settings.
What is the right purchasing strategy for your company? The fit between strategic intent, strategic purchasing and perceived environmental uncertainty
Authors: Patrucco Andrea S. , Luzzini Davide , Krause Daniel , Moretto Antonella Maria
Published: May 2023

Purpose

The authors empirically examine purchasing strategy typologies based on strategic intent (i.e. competitive priorities) and practices used to achieve these priorities. The authors further investigate the implementation conditions of such strategies based on perceived uncertainty and strategic purchasing.

Design/methodology/approach

The authors utilize case study data from 11 international service and manufacturing firms with global supply chains. Each company was profiled based on the level of perceived environmental uncertainty, the characteristics of strategic purchasing, the use of relevant purchasing practices and its ability to create value through purchasing.

Findings

The study findings show that four purchasing strategy types exist: Purchasing Rationalization, Supply Base Optimization, Purchasing as a Service and World-Class Supply Base Management. Lower levels of perceived environmental uncertainty favor the adoption of rationalization strategies (i.e. Purchasing Rationalization and Supply Base Optimization), while increased uncertainty leads companies to switch to relationship-focused strategies (i.e. Purchasing as a Service and World-Class Supply Base Management). Further, that specific components of strategic purchasing (i.e. strategic planning, maturity, status and report level) enable the successful implementation of different strategy types.

Originality/value

This research contributes to the existing literature by outlining the different types of purchasing strategies and the external and internal factors that need to be considered to achieve strategic alignment and value creation in purchasing, and by classifying purchasing strategy types at the functional level based on empirical evidence.
Working capital and firm performance: role of COVID-19 disruption
Authors: Pant Pushpesh , Rathore Pradeep , Dadsena Krishna kumar , Shandilya Bhaskar
Published: May 2023

Purpose

This study examines the performance effect of working capital for a large sample of Indian manufacturing firms in light of supply chain disruption, i.e. the COVID-19 pandemic.

Design/methodology/approach

This study is based on secondary data collected from the Prowess database on Indian manufacturing firms listed on the Bombay Stock Exchange (BSE) 500. Panel data regression analyses are used to estimate all models. Moreover, this study has employed robust standard errors to consider for heteroscedasticity concerns.

Findings

The results challenge the current notion of working capital investment and reveal that higher working capital has a positive and significant impact on firm performance. Further, it highlights that Indian manufacturing firms suffered financially post-COVID-19 as they significantly lack the working capital to run day-to-day operations.

Originality/value

This research contributes to the scant literature by examining the association between working capital financing and firm performance in light of the COVID-19 pandemic, representing typical developing economies like India.