bluuebunny/crossref_metadata_2025 huggingface dataset:
Opening the black box of article retractions: exploring the causes and consequences of data management errors
Authors: Kovacs Marton , Varga Marton A. , Dianovics Dominik , Poldrack Russell A. , Aczel Balazs
Published: December 2024

The retraction of an article is probably the most severe outcome of a scientific project. While great emphasis has been placed on articles retracted due to scientific misconduct, studies show many retractions are due to honest errors. Unfortunately, in most cases, retraction notices do not provide sufficient information to determine the specific types and causes of these errors. In our study, we explored the research data management (RDM) errors that led to retractions from the authors’ perspectives. We collected responses from 97 researchers from a broad range of disciplines using a survey design. Our exploratory results suggest that just about any type of RDM error can lead to the retraction of a paper, and these errors can occur at any stage of the data management workflow. The most frequently occurring cause of an error was inattention. The retraction was an extremely stressful experience for the majority of our sample, and most surveyed researchers introduced changes to their data management workflow as a result. Based on our findings, we propose that researchers revise their data management workflows as a whole instead of focusing on certain aspects of the process, with particular emphasis on tasks vulnerable to human fallibility.
Changes in wing resonance in dried preserved crickets
Authors: Laskri Sophia , Holmes Lewis B. , Dixon Thomas , Robillard Tony , Montealegre-Z Fernando
Published: December 2024

Male crickets sing to attract females for mating. Sound is produced by tegminal stridulation, where one wing bears a plectrum and the other a wing vein modified with cuticular teeth. The carrier frequency (

f
c

) of the call is dictated by the wing resonance and the rate of tooth strikes. Therefore, the

f
c

varies across species due to the size of the vibrating membranes on the wings and/or the speed of tooth strikes. But how well is the resonant frequency (

f
o

) conserved in dried preserved specimens? This project is designed to investigate the gradual change in cricket wing

f
o

over time and aims to produce equations that help to predict or recover the original natural frequency of wing vibration in dry-preserved crickets and allies. Using laser Doppler vibrometry, we scanned the wings of living specimens to determine their

f
o

. The specimens were then preserved, allowing us to continue measuring the wings

f
o

as they desiccate. We found that after the first week,

f
o

increases steeply, reaching a plateau and stabilizing for the following months. We go on to propose a model that can be used to recover the original

f
c

of the wings of preserved Ensifera that use pure tones for communication. Models were corroborated using preserved specimens previously recorded and mounted in dry collections for more than 10 years.
Identification and field testing of sex-attractant semiochemicals produced by male deer mice,
Peromyscus maniculatus
Authors: Varner Elana , Gries Regine , Takács Stephen , Jackson Hanna , Purdey Leah , Gofredo Daniella , Bibal Alishba , Gries Gerhard
Published: December 2024

Following previous reports that male deer mice,
Peromyscus maniculatus
, produce chemical signals that attract conspecific females, we analysed and field-tested sex-attractant semiochemicals (message-bearing chemicals) of male deer mice. Field traps baited with urine- and faeces-soiled bedding of male mice captured adult female, but not male, mice, indicating dissemination of sex-attractant semiochemicals from the males’ excreta. Analysing excreta headspace volatiles of both males and females by gas chromatography–mass spectrometry revealed that 5-methyl-2-hexanone was male-specific, and that eight other ketones (3-methyl-2-pentanone, 2-hexanone, 4-heptanone, 2-heptanone, 6-methyl-2-heptanone, 3-octanone, 2-octanone, 2-nonanone) were 2.6–5.6 times more abundant in male, than in female, samples. In a field experiment with paired trap boxes, treatment boxes baited with the synthetic ketone lure captured 3.4 times more females (17 : 5) and 1.6 times fewer males (5 : 8) than corresponding unbaited boxes. In a follow-up paired-trap field experiment, treatment boxes baited with both the ketone lure and synthetic testosterone captured 8 times more mature females and 2.3 times more immature females, but 9 times fewer immature males, than control boxes baited only with the ketone lure, all indicating that testosterone is a synergistic sex-attractant semiochemical. As previously shown in house mice,
Mus musculus
, and brown rats,
Rattus norvegicus
, sex-attractant semiochemicals of male deer mice comprise both volatile and sex steroid components.
Identification of a novel nuclease activity in human DDX49 helicase
Authors: Parkes Ashley J. , Anandavijayan Sabesan , Lou-Hing Anna , Downs Olivia , Killelea Tom , Martin Louise , Kapllanaj Fiorela , Bolt Edward L.
Published: December 2024

Human DDX49 is an emerging target in cancer progression and retroviral diseases through its essential roles in nucleolar RNA processing. Here, we identify nuclease activity of human DDX49, which requires active site aspartate residues within a conserved region of metazoan DDX49s that is absent from yeast and archaeal DDX49 homologues. We provide evidence that DDX49 nuclease activity is facilitated by its helicase activity. Using CRISPR-Cas9 genetic editing, we show that a heterozygous (
DDX49
+/−
) U2OS cell line is defective at cell migration, a phenotype supporting the association of DDX49 with cancer cell invasiveness. Measurement of RNAs in
DDX49
+/−
indicates that DDX49 is required to sustain levels of 5.8S rRNA.
Linking selection to demography in experimental evolution of active death in a unicellular organism
Authors: Zeballos Nathalie , Rieu Océane , Fereol Stanislas , Leung Christelle , Chevin Luis-Miguel
Published: December 2024

Deciphering how natural selection emerges from demographic differences among genotypes, and reciprocally how evolution affects population dynamics, is key to understanding population responses to environmental stress. This is especially true in non-trivial ecological scenarios, such as programmed cell death (PCD) in unicellular organisms, which can lead to massive population decline in response to stress. To understand how selection may operate on this trait, we exposed monocultures and mixtures of two closely related strains of the microalga
Dunalliela salina
, one of which induces PCD, to multiple cycles of hyper-osmotic shocks, and tracked demography and selection throughout. Population dynamics were consistent between mixtures and monocultures, suggesting that selection on PCD does not involve strong ecological interactions. The PCD-inducing strain was maintained throughout the experiment despite an initial decline, by a combination of fast population rebound following each decline, and density-dependent competition dynamics near the stationary phase that were independent of these initial population fluctuations. As a result of PCD maintenance, population decline in response to environmental stress was not counter-selected in our experiment, but persisted over 13 cycles of salinity. Our results highlight how analysing the demographic underpinnings of fitness and competition can shed light on the mechanisms underlying selection and eco-evolutionary dynamics.
Independent and differential effects of arbuscular mycorrhizal fungal composition and plant pathogens on plant traits and nitrogen uptake
Authors: Zhang Li , Rong Yizhong , Zhang Peng , Lin Ziyuan , Hu Kui , Wang Xingxing , Liu Xiang , Liu Mu
Published: December 2024

Arbuscular mycorrhizal fungi (AMF), as microbial mutualists, interact with various microbial taxa, including pathogens, and significantly shape the ecology and evolution of their host species. However, how AMF and pathogens jointly or independently affect plant traits and nitrogen uptake remains unclear. Here, we conducted a factorial experiment with three AMF treatments (AMF-free-control,
Funneliformis mosseae
, and a mixture of AMF species of
F. mosseae
and
C. etunicatum
), four plant–pathogen pairs, each under two pathogen treatments (one pathogen and a pathogen-free control). After 65 days of growth, we measured AMF colonization, pathogen infection, plant functional traits and ammonium and nitrate uptake. Our findings reveal that AMF and pathogens independently influence plant traits and nitrogen uptake, with no observed interactions between them. Specifically, colonization by
F. mosseae
or a mixed AMF species reduced nitrate uptake and plant height, without affecting root traits or ammonium uptake. In contrast, pathogen infection enhanced acquisitive root traits, such as increased specific root length and area but did not impact shoot traits or nitrogen uptake. These results broaden our understanding of the tripartite interactions among plants, AMF and pathogens, offering insights into how plant–microbial relationships influence plant health, growth and nitrogen cycling.
Soleus H-Reflex Up-Conditioning during Sciatic Nerve Regeneration in Rats Improves Recovery of Locomotion
Authors: Chen Yi , Wang Yu , Chen Lu , Yang Xinxin , Gemoets Darren E. , Chen Xiang Yang , Wolpaw Jonathan R.
Published: December 2024

Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, induces plasticity in the brain and spinal cord that increases (up-conditioning) or decreases (down-conditioning) the reflex elicited by primary afferent input to the spinal motoneuron. In rats in which the sciatic nerve is transected and repaired, soleus (SOL) H-reflex up-conditioning during regeneration strengthens primary afferent reinnervation of SOL motoneurons and improves recovery of the SOL H-reflex. This suggests that H-reflex up-conditioning could improve functional recovery after nerve injury and repair. To explore this possibility, we examined the impact of SOL H-reflex up- or down-conditioning during sciatic regeneration on recovery of locomotor symmetry. Sprague-Dawley rats were implanted with EMG electrodes in right SOL and a stimulating cuff on right posterior tibial nerve. After control data collection, right sciatic nerve was transected and repaired. Control EMG and H-reflex data collection continued for 20 more days. The rat was then exposed for 100 days to either: continued control data collection; SOL H-reflex up-conditioning; or SOL H-reflex down-conditioning. Locomotor EMG, H-reflex, and kinematics were assessed before nerve transection and 120 days after transection. H-reflex up-conditioning improved H-reflex recovery and also restored right/left step symmetry. H-reflex down-conditioning did not worsen H-reflex recovery or right/left step asymmetry. These results suggest that H-reflex up-conditioning might enhance functional recovery after nerve injury in humans. They also confirm previous results indicating that compensatory plasticity prevents inappropriate H-reflex conditioning (i.e., down-conditioning) from further impairing function.
Transcription factors associated with regulation of transcriptome in human thigh and calf muscles at baseline and after six days of disuse
Authors: Borzykh Anna A. , Makhnovskii Pavel A. , Ponomarev Ivan I. , Vepkhvadze Tatiana F. , Lednev Egor M. , Rukavishnikov Ilya V. , Orlov Oleg I. , Tomilovskaya Elena S. , Popov Daniil V.
Published: December 2024

Disuse has a negative impact on the postural muscles of the trunk and legs. Different leg muscles demonstrate a differentiated and conservative response to disuse, in terms of a decrease in muscle mass, strength, aerobic performance, and changes in gene expression. We aimed to identify transcription factors regulating gene expression at baseline and after disuse in humanm. soleus– a “slow” muscle with a strong postural function, and “mixed”m. vastus lateralis. Biopsies were taken from these muscles prior to and after 6 days of strict disuse (dry immersion). The enriched transcription factor binding sites (and corresponding factors) in the individual promoter regions of co-expressed genes were examined using the positional weight matrix approach. The baseline transcriptomic profiles and the disuse-induced changes (RNA-seq) differ significantly between muscles. In particular, the specific and significant response to disuse inm. soleuswas found to be strongly related to the suppression of genes regulating the mitochondrial energy metabolism, the activation of the inflammatory response and the ubiquitin-proteasome system. This response is associated with the proinflammatory transcription factors such as families IRF, STAT, and other. The validity of approximately two-thirds of the predicted transcription factors was indirectly confirmed by the analysis of their function described in the literature. These identified transcription factors appear to be promising candidates for future targeted studies that mechanistically investigate gene expression regulation in various muscles at baseline, following disuse or inactivity.

Highlights

Disuse has a different negative impact on the different human postural leg muscles.

The transcriptome regulation inm. soleusandm. vastus lateralisdiffers markedly.

The gene response to disuse inm. soleusis greater than inm. vastus lateralis.

This partially related to activation of inflammation-induced transcription factors.
Gestational diabetes mellitus and hypertension causally increased the risk of postpartum depression: a Mendelian randomization analysis
Authors: Jia Jia , Liu Haojie , Cao Liying , Xing Ying
Published: December 2024

Background

Observational studies have presented inconsistent findings on the association between gestational diabetes mellitus, gestational hypertension, and postpartum depression. This study used Mendelian randomization to examine the potential causal relationship between gestational diabetes mellitus, gestational hypertension, and postpartum depression.

Methods

We obtained data from genome-wide association study databases. Single nucleotide polymorphisms associated with gestational diabetes mellitus (5,687 cases; 117,892 controls), gestational hypertension (7,686 cases; 115,893 controls), and postpartum depression (7,604 cases; 59,601 controls) were analyzed. Various Mendelian randomization methods were applied, including inverse variance weighted, weighted median, MR-Egger, simple mode, and weighted mode. Sensitivity analyses such as the MR-Egger intercept test, funnel plot, MR-PRESSO analysis, Cochran’s Q test, and leave-one-out tests confirmed the robustness of our findings. The MR-Steiger test was applied to verify the causal direction from exposure to outcome.

Results

Genetically predicted gestational diabetes mellitus was significantly associated with increased postpartum depression risk (IVW OR = 1.09; 95% CI: 1.03- 1.14; p = 1.24×10⁻³), as was gestational hypertension (IVW OR = 1.08; 95% CI: 1.01- 1.15; p = 0.01). Multiple sensitivity analyses further reinforced the validity of these findings. Multivariable Mendelian randomization adjusting for gestational hypertension confirmed the independent effect of gestational diabetes mellitus on postpartum depression and vice versa for gestational hypertension.

Conclusion

Both gestational diabetes mellitus and gestational hypertension increase the incidence of postpartum depression. By focusing on interventions to manage these prenatal conditions, nursing professionals can play a crucial role in potentially reducing the incidence of postpartum depression.
Structurally distinct manganese-sensing riboswitch aptamers regulate diverse expression platform architectures
Authors: Stephen Christine N. , Palmer Danea E. , Bautista Clarisa , Mishanina Tatiana V.
Published: December 2024

Manganese (Mn)-sensing riboswitches protect bacteria from Mn toxicity by upregulating expression of Mn exporters. The Mn aptamers share key features but diverge in other important elements, including within the metal-binding core. Although X-ray crystal structures of isolated aptamers exist, these structural snapshots lack crucial details about how the aptamer communicates the presence or absence of ligand to the expression platform. In this work, we investigated the Mn-sensing translational riboswitches inE. coli(mntPandalx), which differ in aptamer secondary structure, nucleotide sequence, and pH-dependence of Mn response. We performed co-transcriptional RNA chemical probing, allowing us to visualize RNA folding intermediates that form and resolveen routeto the final folded riboswitch. For the first time, we report that sampling of metal ions by the RNA begins before the aptamer synthesis and folding are complete. At a single-nucleotide resolution, we pinpoint the transcription window where “riboswitching” occurs in response to Mn binding and uncover key differences in how thealxandmntPriboswitches fold. Finally, we describe riboswitch-specific effects of pH, providing insights into how two members of the same riboswitch family differentially sense two distinct environmental cues: concentration of Mn and pH.

GRAPHICAL ABSTRACT
Aperiodic parameters of the fMRI power spectrum associate with preterm birth and neonatal age
Authors: Suuronen Ilkka , Luotonen Silja , Railo Henry , Airola Antti , Bano Wajiha , Merisaari Harri , Pulli Elmo P. , Mariani Wigley Isabella L.C , Vartiainen Elena , Hashempour Niloofar , Karlsson Hasse , Karlsson Linnea , Kringelbach Morten L. , Batalle Dafnis , Tuulari Jetro J.
Published: December 2024

While strong associations of structural magnetic resonance imaging (sMRI) with preterm birth and post-menstrual age (PMA) have been reported, such associations for functional MRI (fMRI) have been considerably weaker. We studied the associations of the aperiodic parameters of neonatal fMRI Blood-oxygen-level-dependent (BOLD) signal power spectrum with preterm birth and PMA at scan using task-free fMRI data from the Developing Human Connectome Project (dHCP). First, we studied the associations of the aperiodic parameters of the BOLD signal from pre- and postcentral gyri with preterm birth and mapped the associations with PMA, postnatal age, and sex. Second, we used machine learning regression to predict PMA and postnatal age with 90 cortical and subcortical regions of interest (ROIs). We found clear differences between preterm and full-term groups, as well as males and females. Furthermore, our machine learning model predicted the age variables with relatively high accuracy (mean test R² = 0.20 – 0.41).
Prevalence of chlamydia, gonorrhoea, and trichomoniasis among male and female general populations in sub-Saharan Africa from 2000-2024: A systematic review and meta-regression analysis
Authors: Michalow Julia , Hall Lauren , Rowley Jane , Anderson Rebecca L. , Hayre Quinton , Chico R. Matthew , Edun Olanrewaju , Knight Jesse , Kuchukhidze Salome , Majaya Evidence , Reed Domonique M. , Stevens Oliver , Walters Magdalene K , Peters Remco PH , Cori Anne , Boily Marie-Claude , Imai-Eaton Jeffrey W.
Published: December 2024

Background

Sub-Saharan Africa (SSA) has the highest sexually transmitted infection (STI) prevalence globally, but information about trends and geographic variation is limited by sparse aetiologic studies, particularly among men. This systematic review assessed chlamydia, gonorrhoea, and trichomoniasis prevalence by sex, sub-region, and year, and estimated male-to-female prevalence ratios for SSA.

Methods

We searched Embase, MEDLINE, Global Health, PubMed, and African Index Medicus for studies measuring STI prevalence among general populations from January 1, 2000, to September 17, 2024. We adjusted observations for diagnostic test performance and used log-binomial mixed-effects meta-regressions to estimate prevalence trends and sex-prevalence ratios.

Findings

Of 5202 records identified, we included 211 studies from 28 countries. In 2020, estimated prevalence among 15-49-year-olds in SSA for chlamydia was 6.6% (95%CI: 5.0-8.2%, n=169 observations) among females and 4.7% (3.4-6.1%, n=33) among males, gonorrhoea was 2.4% (1.4-3.3%, n=171) and 1.7% (0.7-2.6%, n=31), and trichomoniasis was 6.8% (3.6-9.9%, n=188) and 1.7% (0.7-2.7%, n=19). Male-to-female ratio estimates were 0.61 (0.53-0.71) for chlamydia, 0.81 (0.61-1.09) for gonorrhoea, and 0.23 (0.18-0.28) for trichomoniasis. From 2010-2020, chlamydia prevalence increased by 34.5% (11.1-62.9%) in SSA, while gonorrhoea and trichomoniasis trends were not statistically significant. Chlamydia and gonorrhoea prevalence were highest in Southern and Eastern Africa, whereas trichomoniasis was similar across sub-regions.

Interpretation

SSA has a high, geographically varied STI burden, with increasing prevalence of chlamydia. Region-specific sex-prevalence ratios differed from existing global ratios and should be considered in future burden estimates. Enhanced sex-stratified surveillance is crucial to guide national programmes and reduce STI prevalence in SSA.

Funding

Gates Foundation, Imperial College London, NIH, UKRI
Dosage compensation of transposable elements in mammals
Authors: Wei Chunyao , Kesner Barry , Weissbein Uri , Wasserzug-Pash Peera , Das Priyojit , Lee Jeannie T.
Published: December 2024

In mammals, X-linked dosage compensation involves two processes: X-chromosome inactivation (XCI) to balance X chromosome dosage between males and females, and hyperactivation of the remaining X chromosome (Xa-hyperactivation) to achieve X-autosome balance in both sexes. Studies of both processes have largely focused on coding genes and have not accounted for transposable elements (TEs) which comprise 50% of the X-chromosome, despite TEs being suspected to have numerous epigenetic functions. This oversight is due in part to the technical challenge of capturing repeat RNAs, bioinformatically aligning them, and determining allelic origin. To overcome these challenges, here we develop a new bioinformatic pipeline tailored to repetitive elements with capability for allelic discrimination. We then apply the pipeline to our recent So-Smart-Seq analysis of single embryos to comprehensively interrogate whether X-linked TEs are subject to either XCI or Xa-hyperactivation. With regards to XCI, we observe significant differences in TE silencing in parentally driven “imprinted” XCI versus zygotically driven “random” XCI. Chromosomal positioning and genetic background impact TE silencing. We also find that SINEs may influence 3D organization during XCI. In contrast, TEs do not undergo Xa-hyperactivation. Thus, while coding genes are subject to both forms of dosage compensation, TEs participate only in Xi silencing. Evolutionary and functional implications are discussed.
Oxidative stress drives potent bactericidal activity of pyrazinamide againstMycobacterium tuberculosis
Authors: Dillon Nicholas A. , Lamont Elise A. , Rather Muzafar A. , Baughn Anthony D.
Published: December 2024

Pyrazinamide (PZA) is a critical component of tuberculosis first-line therapy due to its ability to kill both growing and non-replicating drug-tolerant populations ofMycobacterium tuberculosiswithin the host. Recent evidence indicates that PZA acts through disruption of coenzyme A synthesis under conditions that promote cellular stress. In contrast to its bactericidal actionin vivo, PZA shows weak bacteriostatic activity againstM. tuberculosisin axenic culture. While the basis for this striking difference betweenin vivoandin vitroPZA activity has yet to be resolved, recent studies have highlighted an important role for cell-mediated immunity in PZA efficacy. These observations suggest that host-derived antimicrobial activity may contribute to the bactericidal action of PZA within the host environment. In this study we show that the active form of PZA, pyrazinoic acid (POA), synergizes with the bactericidal activity of host-derived reactive oxygen species (ROS). We determined that POA can promote increased cellular oxidative damage and enhanced killing ofM. tuberculosis. Further, we find that the thiol oxidant diamide is also able to potentiate PZA activity, implicating thiol oxidation as a key driver of PZA susceptibility. Using a macrophage infection model, we demonstrate the essentiality of interferon-γ induced ROS production for PZA mediated clearance ofM. tuberculosis. Based on these observations, we propose that thein vivosterilizing activity of PZA can be mediated through its synergistic interaction with the host oxidative burst leading to collateral disruption of coenzyme A metabolism. These findings will enable discovery efforts to identify novel host- and microbe-directed approaches to bolster PZA efficacy.
Spatially barcoding biochemical reactions using DNA nanostructures unveil a major contact mechanism in proximity labeling
Authors: Yang Zhe , Zhang Yu , Fang Yuxin , Zhang Yuan , Du Jiasheng , Shen Xiaowen , Zhang Kecheng , Zou Peng , Chen Zhixing
Published: December 2024

Proximity labeling techniques like TurboID and APEX2 have become pivotal tools in spatial omics research for studying protein interactions. However, the biochemical mechanisms underlying these reactive species-mediated labelings, particularly the spatial patterns of labeling methods within the sub-μm range, remain poorly understood. Here, we employed DNA nanostructure platforms to precisely measure the labeling radii of TurboID and APEX2 throughin vitroassays. Our DNA nanoruler design enables the deployment of oligonucleotide-barcoded labeling targets with nanometer precision near the enzymes. By quantifying labeling yields using quantitative PCR and mapping them against target distances, we uncovered surprising insights into the labeling mechanisms. Contrary to the prevailing diffusive labeling model, our results demonstrate that TurboID primarily operates through contact-dependent labeling. Similarly, APEX2 shows high labeling efficiency within its direct contact range. In parallel, it exhibits a low-level diffusive labeling towards more distant phenols. These findings reframe our understanding in the mechanism of proximity labeling enzymes, at the same time highlight the potential of DNA nanotechnology in spatially profiling reactive species.
Semantic mining of functionalde novogenes from a genomic language model
Authors: Merchant Aditi T. , King Samuel H. , Nguyen Eric , Hie Brian L.
Published: December 2024

Generative genomics models can design increasingly complex biological systems. However, effectively controlling these models to generate novel sequences with desired functions remains a major challenge. Here, we show that Evo, a 7-billion parameter genomic language model, can perform function-guided design that generalizes beyond natural sequences. By learning semantic relationships across multiple genes, Evo enables a genomic “autocomplete” in which a DNA prompt encoding a desired function instructs the model to generate novel DNA sequences that can be mined for similar functions. We term this process “semantic mining,” which, unlike traditional genome mining, can access a sequence landscape unconstrained by discovered evolutionary innovation. We validate this approach by experimentally testing the activity of generated anti-CRISPR proteins and toxin-antitoxin systems, includingde novogenes with no significant homology to any natural protein. Strikingly, in-context protein design with Evo achieves potent activity and high experimental success rates even in the absence of structural hypotheses, known evolutionary conservation, or task-specific fine-tuning. We then use Evo to autocomplete millions of prompts to produce SynGenome, a first-of-its-kind database containing over 120 billion base pairs of AI-generated genomic sequences that enables semantic mining across many possible functions. The semantic mining paradigm enables functional exploration that ventures beyond the observed evolutionary universe.
High pressure induced superconductivity and chirality-neutral Fermi surface in
SrSi2
Authors: Yao M.-Y. , Noky J. , Mu Q.-G. , Manna K. , Kumar N. , Strocov V. N. , Shekhar C. , Medvedev S. , Sun Y. , Felser C.
Published: December 2024

In this study, we investigate the electronic structure and topological properties of the compound SrSi2 using angle-resolved photoemission spectroscopy (ARPES), electrical transport measurements, and calculations. In contrast to recent theoretical predictions that SrSi2 is a Weyl semimetal with robust Weyl nodes and Fermi arcs, our ARPES measurements on undoped and Ca-doped SrSi2 single crystals show no evidence of the predicted Weyl fermions or Fermi arcs at ambient pressure. Instead, ARPES and transport data show that SrSi2 is a narrow-gap semiconductor at ambient conditions. Our hybrid functional calculations also find a small band gap, in agreement with experiments. However, by applying external pressure, we induce a topological phase transition where the electronic bands overlap and Weyl nodes appear, as confirmed by transport measurements and calculations. Interestingly, we also observe a pressure-induced superconducting transition above 20 GPa. Our results establish SrSi2 as a platform to study the interplay between topological states and superconductivity driven by external pressure. Importantly, our results challenge the previously predicted intrinsic Weyl semimetallic nature of SrSi2 and highlight the need for combined experimental and advanced computational approaches to correctly describe the complex electronic structures in topological materials.

Published by the American Physical Society
2024
Self-Interacting Dark Sectors in Supernovae Can Behave as a Relativistic Fluid
Authors: Fiorillo Damiano F. G. , Vitagliano Edoardo
Published: December 2024

We revisit supernova (SN) bounds on a hidden sector consisting of millicharged particles χ and a massless dark photon. Unless the self-coupling is fine-tuned to be small, rather than exiting the SN core as a gas, the particles form a relativistic fluid and subsequent dark QED fireball, streaming out against the drag due to the interaction with matter. Novel bounds due to excessive energy deposition in the mantle of low-energy supernovae can be obtained. The cooling bounds from SN 1987A are unexpectedly not affected in the free-streaming regime. The inclusion of χχ¯→standard model substantially modifies the constraints in the trapping regime, which can only be treated hydrodynamically. Our results can be adapted to generic sub-GeV self-interacting dark sectors.

Published by the American Physical Society
2024
New Constraints on the Melting Temperature and Phase Stability of Shocked Iron up to 270 GPa Probed by Ultrafast X-Ray Absorption Spectroscopy
Authors: Balugani S. , Hernandez J. A. , Sévelin-Radiguet N. , Mathon O. , Recoules V. , Kas J. J. , Eakins D. E. , Doyle H. , Ravasio A. , Torchio R.
Published: December 2024

Studying the properties and phase diagram of iron at high-pressure and high-temperature conditions has relevant implications for Earth’s inner structure and dynamics and the temperature of the inner core boundary (ICB) at 330 GPa. Also, a hexagonal-closed packed to body-centered cubic (bcc) phase transition has been predicted by many theoretical works but observed only in a few experiments. The recent coupling of high-power laser with advanced x-ray sources from synchrotrons allows for novel approaches to address these issues. Here, we present a study on shock compressed iron up to 270 GPa and 5800 K probed by single-pulse (100 ps FWHM) x-ray absorption spectroscopy (XAS). Based on the analysis of the XAS spectra, we provide structural identification and bulk temperature measurements along the Hugoniot up to the melting. These results rule out the predicted transition to a high-temperature bcc phase and allow one to discriminate among existing equations of state models and melting curves. In particular, we report the first bulk temperature measurement in shock compressed iron on the melting plateau at 240(20) GPa and 5345(600) K. The melting curve resulting from our work extrapolates to a temperature of 6202(514) K at 330 GPa and represents a refined upper bound for the ICB temperature.

Published by the American Physical Society
2024
Shaping Quantum Noise through Cascaded Nonlinear Processes in a Dissipation-Engineered Multimode Cavity
Authors: Pontula Sahil , Salamin Yannick , Roques-Carmes Charles , Soljačić Marin
Published: December 2024

Multimode quantum light is enticing for several applications, spanning imaging, spectroscopy, communication, and more. Parametric nonlinear processes have been vital in realizing squeezed and other quantum states of light. However, most work exploiting these processes has focused on generating multimode squeezed vacua and squeezing in mode superpositions (supermodes). Bright squeezing in multiple discrete frequency modes, if realized, could unlock novel applications in quantum-enhanced spectroscopy and optical quantum computing. Here, we show how dissipation engineering of a multimode nonlinear cavity with cascaded three-wave-mixing processes allows us to shape above-threshold frequency combs that feature strong single-mode output amplitude noise squeezing over 10 dB below the shot-noise limit, tunable across the comb. In addition, we demonstrate squeezing for multiple discrete frequency modes above threshold. This bright squeezing arises from enhancement of the (noiseless) nonlinear rate relative to decay rates in the system due to the cascaded generation of photons in a single idler “bath” mode. A natural consequence of the strong nonlinear coupling in our system is the creation of an effective cavity in the synthetic frequency dimension that sustains Bloch oscillations in the modal energy distribution. Bloch mode engineering could provide an opportunity to better control nonlinear energy flow in the synthetic frequency dimension, with exciting applications in quantum random walks and topological photonics. Lastly, we show evidence of long-range correlations in amplitude noise between discrete frequency modes, enabling long-range entanglement in a synthetic frequency dimension and providing a new resource for quantum communication.

Published by the American Physical Society
2024
Thermal deformation compensation scheme to the sub-nanometre level of a piezoelectric offset mirror for MHz repetition rate free-electron laser
Authors: Sun Baoning , Li Qinming , Yang Chuan , Hu Kai , Xu Zhongmin , Dong Xiaohao , Zhang Weiqing , Yang Xueming
Published: December 2024

Free-electron laser (FEL) facilities operating at MHz repetition rates can emit lasers with average powers reaching hundreds of watts. Partial absorption of this power induces thermal deformation of a few micrometres on the mirror surface. Such deformation degrades the characteristics of the reflected photon beam, leading to focal spot aberrations and wavefront distortions that fail to meet experimental requirements. A robust method is necessary to correct the mirror surface shape to meet the Maréchal criterion. This paper proposes a thermal deformation compensation scheme for offset mirrors operating at MHz repetition rates using a piezoelectric deformable mirror. The mirror is side-mounted with slots filled with an indium–gallium alloy, which house copper tubes for water cooling. Eighteen groups of piezo actuators are symmetrically attached to the top and bottom surfaces. The scheme incorporates finite-element analysis for simulation and post-processing verification, utilizing a differential evolution (DE) algorithm for global optimization. The DE algorithm effectively addresses the voltage constraints that the traditional singular value decomposition algorithm cannot handle. Under an X-ray wavelength of 1 nm, the peak-to-valley (PV) height error of the mirror was reduced from 1340.8 nm to 1.1 nm, and the root-mean-square (RMS) height error decreased from 859.1 nm to 0.18 nm. The slope error was corrected to 154 nrad PV and 24 nrad RMS. Significant results were also achieved at an X-ray wavelength of 3 nm. Wave-optics simulations verified the reliability of this approach, and effects on key mirror parameters and conditions were systematically analysed.
Personalized interactive urban maps for autism: an innovative approach involving persons with Level 1 autism spectrum disorder to user-centered design
Authors: Brighenti Stefania , Cena Federica , Keller Roberto
Published: December 2024

Purpose

Because of social interaction difficulties, cognitive characteristics and sensory sensitivity, people with autism spectrum disorder (ASD) may struggle with independence and active participation in urban contexts. Through understanding how people with ASDs experience and perceive urban spaces, the Personalized Interactive Urban Maps for Autism (PIUMA) project’s purpose is to create a useful platform to support persons with ASD in their movements in the city, helping them in managing their daily lives, promoting their autonomy and active participation in urban contexts, taking in to account their direct point of view. This paper aim to present a user-centered approach involving autistic people.

Design/methodology/approach

The authors involved researchers with different backgrounds applying mixed research techniques such as semi-structured qualitative interviews, participatory design, exploiting user-adapted systems techniques, human–computer interaction techniques and interviews. The authors involved people with autism (PWA) from the beginning of the project to gain user requirements, as well as to assess the acceptability and effectiveness of our solution in the final stage. In specific phases of the project, the authors involved a group of parents of PWA and a group of neurotypical individuals as a control group.

Findings

The authors collected various data and created an App taking into account PWA needs, suggestions and points of view.

Research limitations/implications

Choosing different methodologies to allow participants to express their point of view, their needs and suggestions, the authors limited the quantitative data collected. The male-to-female ratio in the study, along with the sample size and participants’ age, can also be considered limitations.

Practical implications

The authors collected information about how autistic people move in urban contexts, represent the space of their cities, move independently and use technological devices. The data the author collected also provides suggestions about how to improve computer systems designed for them.

Social implications

The results suggest how to improve computer systems designed for autistic people and how to encourage their full participation in community life according to their cognitive and sensory characteristics.

Originality/value

The PIUMA project takes into account the direct input of PWA in all the different stages from conception and design to deployment of the device in a human-centered design approach.
Evaluating occupational health and safety practices in an airport construction project in Nepal
Authors: Giri Om Prakash , Sainju Pratik Raj , Htet Arkar
Published: December 2024

Purpose

This study examines the implementation and performance of Occupational Health and Safety (OHS) practices in the Pokhara Regional International Airport Project (PRIAP), a key public infrastructure initiative in Nepal. Given airports' significance to Nepal’s economy, particularly for tourism and trade, the research highlights the unique safety challenges in airport construction, addressing gaps in OHS management in developing countries.

Design/methodology/approach

A case study methodology focused on the PRIAP enabled a thorough analysis of safety practices. Data were gathered using structured questionnaires from various stakeholders. The Cronbach’s alpha and relative importance index (RII) were used to assess response reliability and ranked factors affecting safety performance.

Findings

The study identifies both strengths and weaknesses in the project’s OHS practices. While plant and equipment handling and financial aspects, such as budget allocation for safety measures and accident compensation, were deemed satisfactory, significant deficiencies were found in hazard identification and the investigation of near misses. These results suggest that improvements are needed in proactive safety management, particularly in worker-management communication.

Research limitations/implications

This study provides valuable insights but is limited by its single-site focus and use of descriptive statistics. Future research should employ advanced statistical methods, like ANOVA, and include multiple construction sites to capture a broader range of OHS challenges. Evaluating the long-term effectiveness of proposed interventions is also essential. Addressing these limitations will enhance the development of comprehensive safety management strategies tailored to the specific needs of construction projects in developing countries.

Practical implications

This study provides practical recommendations for improving OHS practices in airport construction and similar large-scale projects in developing countries. Enhanced hazard identification and improved communication among stakeholders can help reduce accidents and boost project efficiency.

Social implications

Improving safety regulations and culture can reduce workplace injuries, enhancing workers' well-being and quality of life. This research supports stronger public policies, helping lower economic burdens from accidents, promoting social stability and increasing public trust in regulatory bodies.

Originality/value

This research contributes to the limited literature on OHS in airport construction projects in developing countries, particularly in Nepal. The case study methodology provides a detailed examination of safety practices and offers a framework for improving OHS in similar projects.
Determinants and impacts of supply chain responsiveness: an empirical research
Authors: Keskin Beyza , Ungan Mustafa Cahit
Published: December 2024

Purpose

The aim of this study is to identify the factors affecting supply chain responsiveness. Additionally, it investigates the relationships between supply chain responsiveness, customer satisfaction and competitive power.

Design/methodology/approach

A quantitative method was adopted. Data were collected from 290 companies operating in Turkey and tested with structural equation modeling.

Findings

The results show that supply chain responsiveness is related to continuous process improvement, supplier integration and environmental uncertainty but not to customer integration. The findings also present relationships between supply chain responsiveness, customer satisfaction and competitive power.

Practical implications

The findings indicate that decision-makers should invest in continuous process improvement and supplier integration. They also need to understand that their supply chain responsiveness depends on the environmental dynamism of their sectors, and they must direct their efforts accordingly. Finally, decision-makers wishing high customer satisfaction and competitive power must value supply chain responsiveness and take necessary actions to achieve it.

Originality/value

A literature review for this study indicated very limited empirical evidence of the relationship between continuous process improvement, supplier integration, customer integration, environmental uncertainty and supply chain responsiveness. Similarly, there was a quest for more research on the relationships between supply chain responsiveness, customer satisfaction and competitive power. This work will enhance the literature by adding knowledge in these areas.
Belonging and beliefs: how social influences drive the intention to purchase foods with health claims
Authors: Sarabia-Sánchez Francisco J. , Küster Boluda Inés , Vila-Lopez Natalia , Sarabia-Andreu Francisco
Published: December 2024

Purpose

This study examines how social influences (need to belong and fear of missing out) and the perceived credibility of health claims affect the intention to purchase foods with health claims.

Design/methodology/approach

Data were obtained from a web-based survey of 844 Spaniards aged 25 years and older, with sex and age quotas. Real product images with health claims contextualized the purchase intention questions, aiding respondents who often struggle to differentiate health from promotional claims.

Findings

Both personal and social dimensions of fear of missing out (FoMO) influence the desire to belong to a healthy group. The intention to purchase food with health claims is also positively associated with the desire to belong. The results reflect the importance of FoMO and the need to belong in enhancing consumers’ tendency to purchase products with health claims. The results also reflect the importance of purchase intention in making health claims perceived as credible.

Originality/value

This study integrates individual aspects (belief in the credibility of health claims) with social aspects (belonging and FoMO) to analyze the intention to purchase foods with health claims. Using authentic product images to aid consumer comprehension adds an innovative dimension, addressing a gap in consumer behavior research.
Knowing and not knowing about algorithms
Authors: Yerbury Hilary , Henninger Maureen
Published: December 2024

Purpose

This paper considers the implications of not knowing – hypocognition – the lack of a cognitive or linguistic representation of a concept, algorithms, held by librarians responsible for programs of information literacy in universities in NSW, Australia.

Design/methodology/approach

A practice-based study of university librarians and their role in the development of algorithmic literacy, using semi-structured interviews and thematic analysis, showed that they had limited socio-technical knowledge of algorithms.

Findings

Not knowing led most participants to anthropomorphise algorithms, including those found in search engines such as Google, sometimes explaining them as something mysterious, although they were aware that the algorithms were gathering data about them and their online interactions. Nonetheless, they delegated responsibility for online activities. These online interactions were not presented in system terms, but often could be interpreted as examples of Goffman’s civil inattention, a social norm used in interactions with strangers, such as fellow passengers. Such an understanding prevented the development of robust algorithmic literacy.

Social implications

With technologies disrupting social norms, algorithms cannot be considered strangers who understand such civility; instead, metaphorically and practically, they rudely rummage through wallets and phones. Acknowledging the implications of the reliance on socio-cultural understandings of algorithms and their anthropomorphic representations for explaining online system-based interactions can present new ways for developing algorithmic literacy.

Originality/value

This study suggests that the links between hypocognition and the anthropomorphising of algorithms can undermine the development of knowledge and skills in information and digital literacies.