bluuebunny/crossref_metadata_2025 huggingface dataset:
Fungi activate Toll-1 dependent immune evasion to induce cell loss in the host brain
Authors: Singh Deepanshu N.D. , Roberts Abigail R.E. , Moraga Enrique Quesada , Alliband David , Ballou Elizabeth , Tsai Hung-Ji , Hidalgo Alicia
Published: April 2024

Fungi evolve within the host, ensuring their own nutrition and reproduction, at the expense of host health. They intervene in hosts’ brain function, to alter host behaviour and induce neurodegeneration. In humans, fungal infections are emerging as drivers of neuroinflammation, neurodegenerative diseases and psychiatric disorders. However, how fungi alter the host brain is unknown. Fungi trigger an innate immune response mediated by the Toll-1/TLR receptor, the adaptor MyD88 and the transcription factor Dif/NFκB, that induce the expression of antimicrobial peptides (AMPs). However, in the nervous system, Toll-1/TLR could also drive an alternative pathway involving the adaptor Sarm, which causes cell death instead. Sarm is the universal inhibitor of MyD88 and could drive immune evasion. The entomopathogenic fungusBeauveria bassianais well-known to activate Toll-1 signalling in innate immunity inDrosophila. In fruit-flies, the adaptor Wek links Toll-1 to Sarm. Thus, here we asked whetherB. bassianacould damage theDrosophilabrain via Toll-1, Wek and Sarm. We show that exposure toB. bassianareduced fly lifespan and impaired locomotion.B. bassianaentered the brain and induced the up-regulation ofAMPs,as well aswekandsarm,within the brain. Exposure toB. bassianacaused neuronal and glial loss in the adultDrosophilabrain. Importantly, RNAi knockdown ofToll-1, wekorsarmconcomitantly with infection preventedB. bassianainduced cell loss. By contrast, over-expression ofwekorsarmwas sufficient to cause dopaminergic neuron loss in the absence of infection. These data show thatB. bassianacaused cell loss in the host brain via Toll-1/Wek/Sarm signalling driving immune evasion. We conclude that pathogens can benefit from an innate immunity receptor to damage the host brain. A similar activation of Sarm downstream of TLRs in response to fungal infections could underlie psychiatric and neurodegenerative diseases in humans.
Communication between DNA polymerases and Replication Protein A within the archaeal replisome
Authors: Martínez-Carranza Markel , Vialle Léa , Madru Clément , Cordier Florence , Tekpinar Ayten Dizkirici , Haouz Ahmed , Legrand Pierre , Le Meur Rémy A. , England Patrick , Dulermo Rémi , Iñaki Guijarro J. , Henneke Ghislaine , Sauguet Ludovic
Published: April 2024

Replication Protein A (RPA) plays a pivotal role in DNA replication by coating and protecting exposed single-stranded DNA, and acting as a molecular hub that recruits additional replication factors. We demonstrated that archaeal RPA hosts a winged-helix domain (WH) that interacts with two key actors of the replisome: the DNA primase (PriSL) and the replicative DNA polymerase (PolD). Using an integrative structural biology approach, combining nuclear magnetic resonance, X-ray crystallography and cryo-electron microscopy, we unveiled how RPA interacts with PriSL and PolD through two distinct surfaces of the WH domain: an evolutionarily conserved interface and a novel binding site. Finally, RPA was shown to stimulate the activity of PriSL in a WH-dependent manner. This study provides a molecular understanding of the WH-mediated regulatory activity in conserved central replication factors such as RPA, which regulate genome maintenance in Archaea and Eukaryotes.
Investigating NovelStreptomycesBacteriophage Endolysins as Potential Antimicrobial Agents
Authors: Maneekul Jindanuch , Chiaha Amanda , Hughes Rachel , Labry Faith , Saito Joshua , Almendares Matthew , Banda Brenda N. , Lopez Leslie , McGaskey Nyeomi , Miranda Melizza , Rana Jenil , Zadeh Brandon R. , Hughes Lee E.
Published: April 2024

Background

As antibiotic resistance has become a major global threat; the World Health Organization (WHO) has urgently called for alternative strategies for control of bacterial infections. Endolysin, a phage-encoded protein, can degrade bacterial peptidoglycan (PG) and disrupt bacterial growth. According to the WHO, there are only three endolysin products currently in clinical phase development. In this study we explore novel endolysins fromStreptomycesphages as only a few of them have been experimentally characterized. Using several bioinformatics tools, we identified nine different functional domain combinations from 250Streptomycesphages putative endolysins. LazerLemon gp35 (CHAP; LL35lys), Nabi gp26 (amidase; Nb26lys), and Tribute gp42 (PGRP/amidase; Tb42lys) were selected for experimental studies. We hypothesized that (1) the proteins of interest will have the ability to degrade purified PG, and (2) the proteins will have potential antimicrobial activity against bacteria from families of importance in antibiotic resistance, such as ESKAPE safe relatives (Enterococcus raffinosus, Staphylococcus epidermidis,Klebsiella aerogenes,Acinetobacter baylyi,Pseudomonas putida, andEscherichia coli).

Results

LL35lys, Nb26lys, and Tb42lys exhibit PG-degrading activity on zymography and hydrolysis assay. The enzymes (100 µg/mL) can reduce PG turbidity to 32-40%. The killing assay suggests that Tb42lys has a broader range (E. coli,P. putida,A. baylyiandK. aerogenes). While Nb26lys better attacks Gram-negative than Gram-positive bacteria, LL35lys can only reduce the growth of the Gram-positive ESKAPE strains but does so effectively with a low MIC90of 2 µg/mL. A higher concentration (≥300 µg/mL) of Nb26lys is needed to inhibitP. putidaandK. aerogenes.

Conclusion

From 250 putative endolysins, bioinformatic methods were used to select three putative endolysins for cloning and study: LL35lys, Nb26lys, and Tb42lys. All have shown PG-degrading activity, a critical function of endolysin. With a low MIC, LL35lys shows activity for the Gram-positive ESKAPE strains, while Nb26lys and Tb42lys are active against the Gram-negatives. Therefore, endolysins fromStreptomycesphage have potential as possible antimicrobial agents against ESKAPE bacteria.
A novel statistical framework for meta-analysis of total mediation effect with high dimensional omics mediators in large-scale genomic consortia
Authors: Xu Zhichao , Wei Peng
Published: April 2024

Meta-analysis is used to aggregate the effects of interest across multiple studies, while its methodology is largely underexplored in mediation analysis, particularly in estimating the total mediation effect of high-dimensional omics mediators. Large-scale genomic consortia, such as the Trans-Omics for Precision Medicine (TOPMed) program, comprise multiple cohorts with diverse technologies to elucidate the genetic architecture and biological mechanisms underlying complex human traits and diseases. Leveraging the recent established asymptotic standard error of the R-squared-based mediation effect estimation for high-dimensional omics mediators, we have developed a novel meta-analysis framework requiring only summary statistics and allowing inter-study heterogeneity. Whereas the proposed meta-analysis can uniquely evaluate and account for potential effect heterogeneity across studies due to, for example, varying genomic profiling platforms, our extensive simulations showed that the developed method was more computationally efficient and yielded satisfactory operating characteristics comparable to analysis of the pooled individual-level data when there was no inter-study heterogeneity. We applied the developed method to 8 TOPMed studies with over 5800 participants to estimate the mediation effects of gene expression on age-related variation in systolic blood pressure and sex-related variation in high-density lipoprotein (HDL) cholesterol. The proposed method is available in R package MetaR2M on GitHub.
Heat tolerance, oxidative stress response tuning, and robust gene activation in early-stageDrosophila melanogasterembryos
Authors: Mikucki Emily E. , O’Leary Thomas S. , Lockwood Brent L.
Published: April 2024

In organisms with complex life cycles, life stages that are most susceptible to environmental stress may determine species persistence in the face of climate change. Early embryos ofDrosophila melanogasterare particularly sensitive to acute heat stress, yet tropical embryos have higher heat tolerance than temperate embryos, suggesting adaptive variation in embryonic heat tolerance. We compared transcriptomic responses to heat stress among tropical and temperate embryos to elucidate the gene regulatory basis of divergence in embryonic heat tolerance. The transcriptomes of tropical and temperate embryos were differentiated by the expression of relatively few genes, including genes involved in oxidative stress. But most of the transcriptomic response to heat stress was shared among all embryos. Further, embryos shifted the expression of thousands of genes and showed robust gene activation, demonstrating that, contrary to previous reports, early embryos are not transcriptionally silent. The involvement of oxidative stress genes in embryonic heat tolerance corroborates recent reports on the critical role of redox homeostasis in coordinating developmental transitions. By characterizing adaptive variation in the transcriptomic basis of embryonic heat tolerance, this study is a novel contribution to the literature on developmental physiology and genetics, which often lacks ecological and evolutionary context.
Evaluation of extraction solvents for untargeted metabolomics to decipher the dissolved organic matter of Antarctic cryoconite holes
Authors: Mundhe Swapnil , Maiti Saborni , Sanyal Aritri , Kadoo Narendra Y , Dhotre Dhiraj , Barvkar Vitthal T , Shaikh Shamim A. , Antony Runa , Paul Dhiraj
Published: April 2024

Cryoconite holes are biological hotspots with a high biogeochemical turnover rate, contributing significantly to the glacial ecosystem’s overall carbon cycles and net fluxes. Unfortunately, the information about the composition of low molecular weight molecules formed through the metabolic processes of cryoconite-dwelling microbes is scanty. These molecules constitute a substantial portion of the dissolved organic matter (DOM) within cryoconite holes. The present study investigated the composition of DOM in cryoconite holes using reverse-phase liquid chromatography (RP-LC) coupled with high-resolution tandem mass spectrometry. We evaluated various solvent combinations of water, methanol, and acetonitrile to extract chemically diverse polar and non-polar metabolites from the cryoconite holes. Among the single solvents, organic-rich MeOH: Water (70:30 v/v) and in parallel 2-single solvent combinations of MeOH: Water (70:30 v/v) and Acetonitrile: Methanol: Water (40:40:20 v/v) provided increased number and chemical diversity of extracted metabolites. Combining RP with the hydrophilic interaction liquid chromatography (HILIC) technique provided the highest number of unique metabolites. This dual-LC and ionization polarity combination increased the detection of metabolic features by 46.96% and 24.52% in single- and two-solvent combinations compared to RP alone. This study developed a simple untargeted metabolomics workflow that is highly sensitive and robust, detecting and potentially identifying a large number of chemically diverse molecules present in the DOM (extracellular) and microbes (intracellular) from the cryoconite holes environment. This method can better characterize DOM’s chemical composition and, after integrating with other ‘omics’ approaches, can be used to examine the link between metabolic pathways and microbial communities in global cryoconite holes or other similar ecosystems, revealing how these earthy systems and their microbial flora control carbon or nutrient storage or release in response to global climate change. Overall, the study presents a valuable methodology for studying the biogeochemistry of cryoconite holes.
MmpL3, Wag31 and PlrA are involved in coordinating polar growth with peptidoglycan metabolism and nutrient availability
Authors: Arejan Neda Habibi , Czapski Desiree R. , Buonomo Joseph A. , Boutte Cara C.
Published: April 2024

Cell growth in mycobacteria involves cell wall expansion that is restricted to the cell poles. The DivIVA homolog Wag31 is required for this process, but the molecular mechanism and protein partners of Wag31 have not been described. In this study ofMycobacterium smegmatis, we identify a connection betweenwag31and trehalose monomycolate (TMM) transportermmpl3in a suppressor screen, and show that Wag31 and polar regulator PlrA are required for MmpL3’s polar localization. In addition, the localization of PlrA and MmpL3 are responsive to nutrient and energy deprivation and inhibition of peptidoglycan metabolism. We show that inhibition of MmpL3 causes delocalized cell wall metabolism, but does not delocalize MmpL3 itself. We found that cells with an MmpL3 C-terminal truncation, which is defective for localization, have only minor defects in polar growth, but are impaired in their ability to downregulate cell wall metabolism under stress. Our work suggests that, in addition to its established function in TMM transport, MmpL3 has a second function in regulating global cell wall metabolism in response to stress. Our data are consistent with a model in which the presence of TMMs in the periplasm stimulates polar elongation, and in which the connection between Wag31, PlrA and the C-terminus of MmpL3 is involved in detecting and responding to stress in order to coordinate synthesis of the different layers of the mycobacterial cell wall in changing conditions.
Inositol pyrophosphate catabolism by three families of phosphatases controls plant growth and development
Authors: Laurent Florian , Bartsch Simon M. , Shukla Anuj , Rico-Resendiz Felix , Couto Daniel , Fuchs Christelle , Nicolet Joël , Loubéry Sylvain , Jessen Henning J. , Fiedler Dorothea , Hothorn Michael
Published: April 2024

Inositol pyrophosphates (PP-InsPs) are nutrient messengers whose cellular concentration must be tightly regulated. Diphosphoinositol pentakisphosphate kinases (PPIP5Ks) generate the active signaling molecule 1,5-InsP8. PPIP5Ks contain additional phosphatase domains involved in PP-InsP catabolism. Plant and Fungi Atypical Dual Specificity Phosphatases (PFA-DSPs) and NUDIX phosphatases (NUDTs) also hydrolyze PP-InsPs. Here we dissect the relative contributions of the three different phosphatase families to plant PP-InsP catabolism and nutrient signaling. We report the biochemical characterization of inositol pyrophosphate phosphatases from Arabidopsis andMarchantia polymorpha. Overexpression of different PFA-DSP and NUDT enzymes affects PP-InsP levels and leads to stunted growth phenotypes in Arabidopsis.nudt17/18/21knock-out mutants have altered PP-InsP pools and gene expression patterns, but no apparent growth defects. In contrast,Marchantia polymorphaMppfa-dsp1ge,Mpnudt1geand Mpvip1gemutants display severe growth and developmental phenotypes associated with changes in cellular PP-InsP levels. Analysis of Mppfa-dsp1geand Mpvip1gesupports a role for PP-InsPs in Marchantia phosphate signaling, and additional functions in nitrate homeostasis and cell wall biogenesis. Simultaneous removal of two phosphatase activities enhances the observed growth phenotypes. Taken together, PPIP5K, PFA-DSP and NUDT inositol pyrophosphate phosphatases play important roles in growth and development by collectively shaping plant PP-InsP pools.

Author summary

Organisms must maintain adequate levels of nutrients in their cells and tissues. One such nutrient is phosphorus, an essential building block of cell membranes, nucleic acids and energy metabolites. Plants take up phosphorus in the form of inorganic phosphate and require sufficient cellular phosphate levels to support their growth and development. It has been shown that plants and other eukaryotic organisms "measure" cellular phosphate levels using inositol pyrophosphate signaling molecules. The concentration of inositol pyrophosphates serves as a proxy for the cellular concentration of inorganic phosphate, and therefore inositol pyrophosphate synthesis and degradation must be tightly regulated. Here, we report that three different families of enzymes contribute to the degradation of inositol pyrophosphates in plants. The different phosphatases together shape cellular inositol pyrophosphate pools and thereby affect inorganic phosphate levels. Loss-of-function mutants of the different enzymes display additional defects in nitrate levels and cell wall architecture, suggesting that inositol pyrophosphates regulate cellular processes beyond inorganic phosphate homeostasis.
Sustained innate interferon is an essential inducer of tertiary lymphoid structures
Authors: Calvanese Anna Laura , Cecconi Virginia , Stäheli Severin , Schnepf Daniel , Pereira Paulo , Gschwend Julia , Heikenwälder Mathias , Schneider Christoph , Ludewig Burkhard , Silina Karina , van den Broek Maries
Published: April 2024

Tertiary lymphoid structures (TLS) resemble follicles of secondary lymphoid organs and develop in non-lymphoid tissues during inflammation and cancer. Which cell types and signals drive the development of TLS is largely unknown.

To investigate early events of TLS development in the lungs, we repeatedly instilled p(I:C) plus ovalbumin (Ova) intranasally. This induced TLS ranging from lymphocytic aggregates to organized and functional structures containing germinal centers. We found that TLS development is independent of FAP+fibroblasts, alveolar macrophages or CCL19 but crucially depends on type I (IFN-I)-but not type III interferon (IFN-III)-signaling.

Mechanistically, IFN-I initiates two synergistic pathways that culminate in the development of TLS. On the one hand, IFN-I induces lymphotoxin (LT)α in lymphoid cells, which stimulate stromal cells to produce the B-cell-attracting chemokine CXCL13 through LTβR-signaling. On the other hand, IFN-I is sensed by stromal cells that produce the T-cell-attracting chemokines CXCL9, CXCL10 as well as CCL19 and CCL21 independently of LTβR. Consequently, B-cell aggregates develop within a week, whereas follicular dendritic cells and germinal centers appear after 3 weeks.

Thus, sustained production of IFN-I together with an antigen is essential for the induction of functional TLS in the lungs.

Graphical abstract
An unexpected path for Malat1 in neurons: trafficking out of the nucleus for translation
Authors: Wright Bradley W. , Wilusz Jeremy E.
Published: April 2024

The Malat1 (metastasis-associated lung adenocarcinoma transcript 1) long noncoding RNA is highly and broadly expressed in mammalian tissues, accumulating in the nucleus where it modulates expression and pre-mRNA processing of many protein-coding genes. In this issue ofGenes & Development, Xiao and colleagues (doi:10.1101/gad.351557.124) report that a significant fraction of Malat1 transcripts in cultured mouse neurons are surprisingly exported from the nucleus. These transcripts are packaged with Staufen proteins in RNA granules and traffic down the lengths of neurites. They then can be released in a stimulus-dependent manner to be locally translated into a microprotein that alters neuronal gene expression patterns.
Earth tomography with the ICAL detector at INO
Authors: Raikwal Deepak , Choubey Sandhya
Published: April 2024

Observing matter effects in atmospheric neutrinos traveling through the entire mantle and core of the Earth is a promising way of enhancing our understanding of Earth’s density structure. In that context we study the prospects of Earth tomography with the ICAL detector at the India-based Neutrino Observatory. While this experiment is smaller in size in comparison to some of the other larger detectors being proposed, it is the only planned neutrino experiment with charge-identification sensitivity. In particular, ICAL can see matter effects separately in neutrinos and antineutrinos. This has been seen to enhance ICAL’s sensitivity to earth matter effects and hence the mass ordering sensitivity for both normal and inverted mass orderings. It is therefore pertinent to see if the ICAL sensitivity to earth tomography is competitive or better with respect to other experiments, especially for the inverted mass ordering, where other experiments suffer reduced sensitivity. We present the sensitivity of ICAL to earth tomography by taking into consideration both the Earth’s mass constraint as well as the hydrostatic equilibrium constraints.

Published by the American Physical Society
2024
Perturbative QCD contribution to transverse single spin asymmetries in the Drell-Yan process and SIDIS
Authors: Benić Sanjin , Hatta Yoshitaka , Kaushik Abhiram , Li Hsiang-nan
Published: April 2024

In a previous publication [Benić , ], we have computed the perturbative QCD contribution to transverse single spin asymmetries (SSAs) in semi-inclusive deep inelastic scattering (SIDIS) involving the gT(x) distribution. In this paper, we first present a more efficient derivation of the asymmetries which is applicable to both transverse and longitudinal SSAs and correct some inconsistencies in our previous calculation. We then adapt the method to compute transverse SSAs in the Drell-Yan process proportional to gT(x) and its gluonic counterpart and discuss the crossing symmetry between the results for SIDIS and the Drell-Yan process. Finally, we present numerical results for various asymmetries measurable at the EIC, RHIC, COMPASS, and Fermilab (SpinQuest), including also part of the genuine twist-three corrections to gT(x) from a recent global analysis. We find that the asymmetries can reach percent-level magnitude, if the kinematics predominantly probes the large-x (valence) region of the polarized proton, but remain at subpercent levels otherwise.

Published by the American Physical Society
2024
Magnetogenesis with gravitational waves and primordial black hole dark matter
Authors: Balaji Shyam , Fairbairn Malcolm , Olea-Romacho María Olalla
Published: April 2024

Strongly supercooled first-order phase transitions (FOPTs) can produce primordial black hole (PBH) dark matter (DM) along with observable gravitational waves (GWs) from bubble collisions. Such FOPTs may also produce coherent magnetic fields generated by bubble collisions and by turbulence in the primordial plasma. Here we find that the requirement for PBH DM can produce large primordial magnetic fields which subsequently yield intergalactic magnetic fields in the present Universe (with magnitude ≲20  pG across coherence length scales of ≃0.001–0.01  Mpc, assuming maximally helical magnetic fields) that easily exceed lower bounds from blazar observations. We follow a largely model-independent approach and highlight the possibility of producing DM and observable multimessenger magnetic fields and GW signals visible in next generation experiments.

Published by the American Physical Society
2024
Pulsar timing array source ensembles
Authors: Allen Bruce , Valtolina Serena
Published: April 2024

The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description? To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.

Published by the American Physical Society
2024
MeV gamma rays from
Q
-ball decay
Authors: Kasuya Shinta , Kawasaki Masahiro , Tsuji Naomi
Published: April 2024

We study the supersymmetric Q balls which decay at present and find that they create a distinctive spectrum of gamma rays at around O(10) MeV. The charge of the Q ball is lepton numbers in order for the lifetime to be as long as the present age of the Universe, and the main decay products are light leptons. However, as the charge of the Q ball decreases, the decay channel into pions becomes kinematically allowed towards the end of the decay, and the pions are produced at rest. Immediately, π0 decays into two photons with the energy of 67.5 MeV, half the pion mass, which exhibits a unique emission line. In addition, π± decay into μ±, which further decay with emitting internal bremsstrahlung, whose spectrum has a sharp cutoff at ∼50  MeV. If the observations find these peculiar features of the gamma-ray spectrum in the future, it could be a smoking gun of the supersymmetric Q-ball decay at present.

Published by the American Physical Society
2024
Exact WKB analysis for
PT
-symmetric quantum mechanics: Study of the Ai-Bender-Sarkar conjecture
Authors: Kamata Syo
Published: April 2024

We consider exact Wentzel-Kramers-Brillouin analysis to a PT symmetric quantum mechanics defined by the potential, V(x)=ω2x2+gx2(ix)ϵ=2 with ω∈R≥0, g∈R>0. We in particular aim to verify a conjecture proposed by Ai-Bender-Sarkar (ABS), that pertains to a relation between D-dimensional PT-symmetric theories and analytic continuation (AC) of Hermitian theories concerning the energy spectrum or Euclidean partition function. For the purpose, we construct energy quantization conditions by exact Wentzel-Kramers-Brillouin analysis and write down their transseries solution by solving the conditions. By performing alien calculus to the energy solutions, we verify validity of the ABS conjecture and seek a possibility of its alternative form by Borel resummation theory if it is violated. Our results claim that the validity of the ABS conjecture drastically changes depending on whether ω>0 or ω=0: If ω>0, then the ABS conjecture is violated when exceeding the semiclassical level of the first nonperturbative order, but its alternative form is constructable by Borel resummation theory. The PT and the AC energies are related to each other by a one-parameter Stokes automorphism, and a median resummed form, which corresponds to a formal exact solution, of the AC energy (resp. PT energy) is directly obtained by acting Borel resummation to a transseries solution of the PT energy (resp. AC energy). If ω=0, then, with respect to the inverse energy level-expansion, not only perturbative/nonperturbative structures of the PT and the AC energies but also their perturbative parts do not match with each other. These energies are independent solutions, and no alternative form of the ABS conjecture can be reformulated by Borel resummation theory.

Published by the American Physical Society
2024
Revisiting the Cosmic String Origin of GW190521
Authors: Aurrekoetxea Josu C. , Hoy Charlie , Hannam Mark
Published: April 2024

For the first time we analyze gravitational-wave strain data using waveforms constructed from strong gravity simulations of cosmic string loops collapsing to Schwarzschild black holes; a previously unconsidered source. Since the expected signal is dominated by a black-hole ringdown, it can mimic the observed gravitational waves from high-mass binary black hole mergers. To illustrate this, we consider GW190521, a short duration gravitational-wave event observed in the third LIGO-Virgo-KAGRA observing run. We show that describing this event as a collapsing cosmic string loop is favored over previous cosmic string analyses by an approximate log Bayes factor of 22. The binary black hole hypothesis is still preferred, mostly because the cosmic string remnant is nonspinning. It remains an open question whether a spinning remnant could form from loops with angular momentum, but if possible, it would likely bring into contention the binary black hole preference. Finally, we suggest that searches for ringdown-only waveforms would be a viable approach for identifying collapsing cosmic string events and estimating their event rate. This Letter opens up an important new direction for the cosmic-string and gravitational-wave communities.

Published by the American Physical Society
2024
Chern mosaic and ideal flat bands in equal-twist trilayer graphene
Authors: Guerci Daniele , Mao Yuncheng , Mora Christophe
Published: April 2024

We study trilayer graphene arranged in a staircase stacking configuration with equal consecutive twist angle. On top of the moiré crystalline pattern, a supermoiré long-wavelength modulation emerges that we treat adiabatically. For each valley, we find that the two central bands are topological with Chern numbers C=±1 forming a Chern mosaic at the supermoiré scale. The Chern domains are centered around the high-symmetry stacking points ABA or BAB and they are separated by gapless lines connecting the AAA points where the spectrum is fully connected. In the chiral limit and at a magic angle of θ∼1.69∘, we prove that the central bands are exactly flat with ideal quantum curvature at ABA and BAB. Furthermore, we decompose them analytically as a superposition of an intrinsic color-entangled state with ±2 and a Landau level state with Chern number ∓1. To connect with experimental configurations, we also explore the nonchiral limit with finite corrugation and find that the topological Chern mosaic pattern is indeed robust and the central bands are still well separated from the remote bands.

Published by the American Physical Society
2024
Investigation on the flow and induced-noise mechanism during the transient start-up process of a mixed-flow pump
Authors: Zhang Jinsong , Wang Xinlong , Yang Chen , Sun Mingkang , Huang Zhenwei
Published: April 2024

Purpose

This study aims to investigate the noise-inducing characteristics during the start-up process of a mixed-flow pump and the impact of different start-up schemes on pump noise.

Design/methodology/approach

This study conducted numerical simulations on the mixed-flow pump under different start-up schemes and investigated the flow characteristics and noise distribution under these schemes.

Findings

The results reveal that the dipole noise is mainly caused by pressure fluctuations, while the quadrupole noise is mainly generated by the generation, development and breakdown of vortices. Additionally, the noise evolution characteristics during the start-up process of the mixed-flow pump can be divided into the initial stage, stable growth stage, impulse stage and stable operation stage.

Originality/value

The findings of this study can provide a theoretical basis for the selection of start-up schemes for mixed-flow pumps, reducing flow noise and improving the operational stability of mixed-flow pumps.
Technology meets clinical practice: Keel Mind as a digital therapy platform
Authors: Austin Sydney , Bandealy Ahad , Cawley Elizabeth
Published: April 2024

Purpose

The purpose of this paper is to highlight current utilizations of advanced technology within the digital mental health platform Keel Mind.

Design/methodology/approach

Keel Mind, based out of Ontario, Canada is a therapeutic delivery platform that dually functions to train clinicians and deliver virtual therapy to clients.

Findings

From personalizing client and therapist matching to using natural language processing (NLP) and artificial intelligence (AI)-driven features Keel Mind supports clinician decision-making to meet the growing mental health needs of the population. Keel Mind functions to provide accessible service, efficiently train high-quality clinicians and enhance clinical outcomes for clients. In a preliminary study within post-secondary students from Ontario, Canada, 90.1% of clients reported liking the platform, and 83.4% reported that they experienced positive mental health outcomes as a result of using Keel Mind.

Practical implications

Keel Mind is a leader within the rapidly developing field of telepsychology and aims to promote positive mental health outcomes worldwide.

Originality/value

This digital showcase is the first published piece of work highlighting the technological capabilities of Keel Mind as a digital therapeutic platform. The intention of this work is to highlight current uses of digital technology within the field of therapeutic practice and to promote technological growth within the field.
Development of a Genetic Algorithm – Artificial Neural Network model to optimize the Dimensional Accuracy of parts printed by FFF
Authors: Hashemi Baghi Ali , Mansour Jasmin
Published: April 2024

Purpose

Fused Filament Fabrication (FFF) is one of the growing technologies in additive manufacturing, that can be used in a number of applications. In this method, process parameters can be customized and their simultaneous variation has conflicting impacts on various properties of printed parts such as dimensional accuracy (DA) and surface finish. These properties could be improved by optimizing the values of these parameters.

Design/methodology/approach

In this paper, four process parameters, namely, print speed, build orientation, raster width, and layer height which are referred to as “input variables” were investigated. The conflicting influence of their simultaneous variations on the DA of printed parts was investigated and predicated. To achieve this goal, a hybrid Genetic Algorithm – Artificial Neural Network (GA-ANN) model, was developed in C#.net, and three geometries, namely, U-shape, cube and cylinder were selected. To investigate the DA of printed parts, samples were printed with a central through hole. Design of Experiments (DoE), specifically the Rotational Central Composite Design method was adopted to establish the number of parts to be printed (30 for each selected geometry) and also the value of each input process parameter. The dimensions of printed parts were accurately measured by a shadowgraph and were used as an input data set for the training phase of the developed ANN to predict the behavior of process parameters. Then the predicted values were used as input to the Desirability Function tool which resulted in a mathematical model that optimizes the input process variables for selected geometries. The mean square error of 0.0528 was achieved, which is indicative of the accuracy of the developed model.

Findings

The results showed that print speed is the most dominant input variable compared to others, and by increasing its value, considerable variations resulted in DA. The inaccuracy increased, especially with parts of circular cross section. In addition, if there is no need to print parts in vertical position, the build orientation should be set at 0° to achieve the highest DA. Finally, optimized values of raster width and layer height improved the DA especially when the print speed was set at a high value.

Originality/value

By using ANN, it is possible to investigate the impact of simultaneous variations of FFF machines’ input process parameters on the DA of printed parts. By their optimization, parts of highly accurate dimensions could be printed. These findings will be of significant value to those industries that need to produce parts of high DA on FFF machines.
Leveraging liminality: how the interim manager’s liminal position facilitates knowledge transfer to client organizations
Authors: Rubin Viktoria
Published: April 2024

Purpose

With the rise of the gig economy, management positions are increasingly staffed with flexible labor, so-called interim managers. They plunge into organizations for a limited period, operating in a liminal position as partly insider, partly outsider. Although several contributions to their client organizations are acknowledged, it is unknown how the interim manager’s knowledge from previous assignments is made useful in the new context under these particular working conditions. Therefore, the purpose of this paper is to increase the understanding of how the interim manager’s knowledge is transferred to the client organization while operating from a liminal position.

Design/methodology/approach

This paper presents an interview-based multiple case study of six interim assignments where knowledge transfer is considered a social and context-dependent process.

Findings

The findings unveil the multifaceted nature of the liminal position, which consists of task orientation, time limitation, political detachment and cultural distance. These facets contribute to knowledge transfer in terms of new shared understandings and joint interests, which in turn might create new practices that augment continuous knowledge-sharing patterns.

Originality/value

The results contribute to the research on flexible work arrangements by shedding light on how the liminal position, predominantly depicted as an obstacle for the individual, might facilitate knowledge transfer. Through the process of knowledge generation, it is shown how a short-term engagement might enable the organization to increase its knowledge over time.
A self‐supervised scheme for ground roll suppression
Authors: Liu Sixiu , Birnie Claire , Bakulin Andrey , Dawood Ali , Silvestrov Ilya , Alkhalifah Tariq
Published: April 2024

In recent years, self‐supervised procedures have advanced the field of seismic noise attenuation, due to not requiring a massive amount of clean labelled data in the training stage, an unobtainable requirement for seismic data. However, current self‐supervised methods usually suppress simple noise types, such as random and trace‐wise noise, instead of the complicated, aliased ground roll. Here, we propose an adaptation of a self‐supervised procedure, namely, blind‐fan networks, to remove aliased ground roll within seismic shot gathers without any requirement for clean data. The self‐supervised denoising procedure is implemented by designing a noise mask with a predefined direction to avoid the coherency of the ground roll being learned by the network while predicting one pixel's value. Numerical experiments on synthetic and field seismic data demonstrate that our method can effectively attenuate aliased ground roll.
Integrated non‐targeted metabolomics and transcriptomics reveals the browning mechanism of scraped ginger (Zingiber officinale Rosc.)
Authors: Tong Moru , Ding Yangfei , YU Hao , Zhang Wei , Wu Deling
Published: April 2024

Ginger (Zingiber officinale Rosc.) possesses a rich nutritional profile, making it a valuable ingredient for a wide range of culinary applications. After removing its outer skin, ginger can be effectively utilized in the production of pickles and other processed food products. However, following scraping, ginger undergoes a series of physiological and biochemical changes during storage, which can impact its subsequent development and utilization in food. Thus, the current study aimed to investigate the browning mechanism of scraped ginger using non‐targeted metabolomics and transcriptomics. The findings revealed 149 shared differential metabolites and 639 shared differential genes among freshly scraped ginger, ginger browned for 5 days, and ginger browned for 15 days. These metabolites and genes are primarily enriched in stilbenes, diarylheptane, and gingerol biosynthesis, phenylpropanoid biosynthesis, and tyrosine metabolism. Through the combined regulation of these pathways, the levels of phenolic components (such as chlorogenic acid and ferulic acid) and the ginger indicator component (6‐gingerol) decreased, whereas promoting an increase in the content of coniferaldehyde and curcumin. Additionally, the activities of polyphenol oxidase (PPO) and peroxidase (POD) were significantly increased (p‐adjust <0.05). This study hypothesized that chlorogenic and ferulic acid undergo polymerization under the catalysis of PPO and POD, thereby exacerbating the lignification of scraped ginger. These findings offer a theoretical foundation for understanding the browning mechanism of ginger after scraping.

Practical Application

Ginger's quality and nutrition can change when its skin is removed. This happens due to physical and biochemical reactions during scraping. The browning that occurs affects both the taste and health benefits of ginger, we can better understand how to prevent browning and maintain ginger's quality. This research sheds light on improving ginger processing techniques for better products.
Effect of cellulase on dough structure and quality characteristics of tough biscuits enriched with potato whole flour
Authors: Liu Xinhua , Zhu Xiao , Zhu Ying , Wang Chenjie , Li Hongjun , Chen Shanfeng
Published: April 2024

Potato whole flour is a promising way to improve the nutrition of tough biscuits, while its gluten‐free characteristic was difficult to form acceptable texture properties. In this study, cellulase was used to degrade the cellulose in dough enriched with potato whole flour, so as to mitigate the interference of cellulose with the gluten network, resulting in forming the potato whole flour biscuit with great characteristics. Results indicated that cellulase within 0.2% led to the gradually reduced G' and G’’ values of dough from 5.50×104 to 4.00×104 and 2.66×104 to 1.35×104, respectively. Cellulase at 0.2% resulted in the significantly increased tensile properties of the dough compared to the control. The incorporation of cellulase within 0.2% also led to the tightly ordered and intact network structure base on the results of SEM, disulfide bonds determination and FTIR. Those results indicated that cellulase was beneficial to improve the baking quality of dough, which was conductive to form tough biscuit with great characteristics. The hardness, crunchiness, crispness and specific volume analysis results confirmed that 0.2% cellulase resulted in the significantly decreased hardness by 45.25% and the significantly increased specific volume, crunchiness and crispness by 24.74%, 121.20% and 156.47%, respectively. Overall, cellulase ultimately improved the quality of the biscuits by improving the properties and structure of the dough. It was of great significance for the utilization of potato whole flour resources and the industrial production of its tough biscuits.

Practical Application

The results showed that inclusion of cellulase led to the reduced hardness and increased crunchiness, crispness, and specific volume of potato whole flour tough biscuits. Cellulase could be used as a potential improver of tough biscuits. This study will provide guidance for practical uses of cellulase in improving potato whole flour dough and tough biscuit quality.
Applications of high‐intensity ultrasound on shrimp: Potential, constraints, and prospects in the extraction and retrieval of bioactive compounds, safety, and quality
Authors: Marques Lucas P. , Bernardo Yago A. A. , Conte‐Junior Carlos A.
Published: April 2024

The global shrimp market holds substantial prominence within the food industry, registering a significant USD 24.7 billion in worldwide exportation in 2020. However, the production of a safe and high‐quality product requires consideration of various factors, including the potential for allergenic reactions, occurrences of foodborne outbreaks, and risks of spoilage. Additionally, the exploration of the recovery of bioactive compounds (e.g., astaxanthin [AX], polyunsaturated fatty acids, and polysaccharides) from shrimp waste demands focused attention. Within this framework, this review seeks to comprehend and assess the utilization of high‐intensity ultrasound (HIUS), both as a standalone method and combined with other technologies, within the shrimp industry. The objective is to evaluate its applications, limitations, and prospects, with a specific emphasis on delineating the impact of sonication parameters (e.g., power, time, and temperature) on various applications. This includes an examination of undesirable effects and identifying areas of interest for current and prospective research. HIUS has demonstrated promise in enhancing the extraction of bioactive compounds, such as AX, lipids, and chitin, while concurrently addressing concerns such as allergen reduction (e.g., tropomyosin), inactivation of pathogens (e.g., Vibrio parahaemolyticus), and quality improvement, manifesting in reduced melanosis scores and improved peelability. Nonetheless, potential impediments, particularly related to oxidation processes, especially those associated with lipids, pose a hindrance to its widespread implementation, potentially impacting texture properties. Consequently, further optimization studies remain imperative. Moreover, novel applications of sonication in shrimp processing, including brining, thawing, and drying, represent a promising avenue for expanding the utilization of HIUS in the shrimp industry.
PAR2‐mediated cellular senescence promotes inflammation and fibrosis in aging and chronic kidney disease
Authors: Ha Sugyeong , Kim Hyun Woo , Kim Kyung Mok , Kim Byeong Moo , Kim Jeongwon , Son Minjung , Kim Doyeon , Kim Mi‐Jeong , Yoo Jian , Yu Hak Sun , Jung Young‐Suk , Lee Jaewon , Chung Hae Young , Chung Ki Wung
Published: April 2024

Cellular senescence contributes to inflammatory kidney disease via the secretion of inflammatory and profibrotic factors. Protease‐activating receptor 2 (PAR2) is a key regulator of inflammation in kidney diseases. However, the relationship between PAR2 and cellular senescence in kidney disease has not yet been described. In this study, we found that PAR2‐mediated metabolic changes in renal tubular epithelial cells induced cellular senescence and increased inflammatory responses. Using an aging and renal injury model, PAR2 expression was shown to be associated with cellular senescence. Under in vitro conditions in NRK52E cells, PAR2 activation induces tubular epithelial cell senescence and senescent cells showed defective fatty acid oxidation (FAO). Cpt1α inhibition showed similar senescent phenotype in the cells, implicating the important role of defective FAO in senescence. Finally, we subjected mice lacking PAR2 to aging and renal injury. PAR2‐deficient kidneys are protected from adenine‐ and cisplatin‐induced renal fibrosis and injury, respectively, by reducing senescence and inflammation. Moreover, kidneys lacking PAR2 exhibited reduced numbers of senescent cells and inflammation during aging. These findings offer fresh insights into the mechanisms underlying renal senescence and indicate that targeting PAR2 or FAO may be a promising therapeutic approach for managing kidney injury.
Will Australia's tightened prescription system reduce nicotine vaping among young people?
Authors: Hall Wayne D.
Published: April 2024

Background

Australia introduced a prescription only policy for e‐cigarettes in 2011 to prevent uptake among youth while allowing smokers to access e‐cigarettes for cessation. This is one of the restrictive forms of regulation for e‐cigarettes recommended by the World Health Organisation.

Aims

To assess whether the policy has prevented e‐cigarette youth uptake and facilitated smokers' access to e‐cigarettes for cessation; and to examine a proposed toughening of the policy.

Methods

An analysis of survey and administrative data on e‐cigarette use and smoking and a critical analysis of the contents of submissions to parliamentary inquiries into the policy.

Results

E‐cigarette use among youth and young adults has increased steeply since 2016 but very few of these products have been obtained through the prescription system, because medical authorities discourage their use. A policy change in 2021 to increase the prescription of e‐cigarettes has not reduced e‐cigarette use among youth and only marginally increased rates of prescribing. Australian policy makers have nonetheless tightened the prescription system by banning any use of e‐cigarettes unless prescribed by a doctor and dispensed by a pharmacist.

Implications

Australia's tightened prescription policy for e‐cigarettes may reduce adolescent vaping but at the risk of reducing smokers' access to e‐cigarettes and increasing the size of the illicit market for combustible cigarettes and e‐cigarettes. A more effective policy would allow vapes to be sold as consumer products by licensed tobacconists under regulations that require prior product approval, plain packaging, bans on their promotion and enforced age restrictions on purchases.