bluuebunny/crossref_metadata_2025 huggingface dataset:
WITHDRAWN: Exercise hypertension and cardiopulmonary exercise performance in essential hypertensive patients taking diverse antihypertensive medications
Authors: Wen Pan , Tengfei Ji , Zhicong Jing , Bingtao Hu , Dan Liu , Jin Wei
Published: July 2024

Withdrawal Statement

The authors have withdrawn their manuscript owing to [The key reasons for requesting the withdrawal of the preprint are as follows. Firstly, there is a serious error in the statistical analysis. Specifically, the data that should have been analyzed as having a normal distribution was mistakenly treated as having a non-normal distribution. This methodological flaw significantly undermines the validity and reliability of the study results. Secondly, in the logistic regression, there was an incorrect assignment of multicategorical independent variables included in the model. Due to these critical mistakes, we firmly believe that withdrawing the preprint is essential to prevent any potential misguidance to the academic community and readers. We are dedicated to rectifying these errors and conducting a meticulous review before resubmitting]. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
The Splice Index as a prognostic biomarker of strength and function in myotonic dystrophy type 1
Authors: Provenzano Marina , Ikegami Kobe , Bates Kameron , Gaynor Alison , Hartman Julia M. , Jones Aileen S. , Butler Amanda , Berggren Kiera N. , Dekdebrun Jeanne , Hung Man , Lapato Dana M. , Kiefer Michael , Thornton Charles , Johnson Nicholas E. , Hale Melissa A.
Published: July 2024

Myotonic dystrophy type 1 (DM1) is a slowly progressive, multisystemic disorder caused by a CTG repeat expansion in theDMPK3’UTR that leads to global dysregulation of alternative splicing. Here, we employed a composite RNA splicing biomarker called the Myotonic Dystrophy Splice Index (SI), which incorporates 22 disease-specific splice events that sensitively and robustly assesses transcriptomic dysregulation across the disease spectrum. Targeted RNA sequencing was used to derive the SI in 95 muscle biopsies of the tibialis anterior collected from DM1 individuals with baseline (n = 52) and 3-months (n = 37) outcomes. The SI had significant associations with timepoint matched measures of muscle strength and ambulation, including ankle dorsiflexion strength (ADF) and 10-meter run/fast walk speed (Pearsonr= -0.719 and -0.680, respectively). Linear regression modeling showed that the combination of baseline ADF and SI was predictive of strength at 3-months (adjusted R2= 0.830) in our cohort. These results indicate the SI can reliably capture the association of disease-specific RNA mis-splicing to physical strength and mobility and may be predictive of future function.
Advancing Early Diagnosis of Alzheimer’s Disease: A Paper-Based Aptasensor for Detecting Aβ(1-42) and p-tau181 from Plasma Using CdTe Quantum Dots
Authors: Balci Ebrar , Yildiz Elif Nur , Oksuz Sevval Sueda , Ahmadli Nihat , Kargidan Miray , Ayyildiz Nilay , Alemdar Esra , Uludag Irem , Hasirci Umut
Published: July 2024

Alzheimer’s Disease (AD), characterized by a gradual onset and a lack of exact therapeutic interventions, underscores the imperative for the development of uncomplicated and cost-effective biosensors capable of detecting its biomarkers. This necessity arises in anticipation of a projected surge in the incidence of AD. Quantum dots (QDs) represent the promising new generation of luminophores owing to their size, composition, and surface-dependent tunable photoluminescence (PL) and photochemical stability. In this study, a paper-based QD aptasensor for the early detection of AD by targeting amyloid beta (Aβ-42) and p-tau181 proteins using Förster Resonance Energy Transfer (FRET) is developed. The sensor employs a Whatman paper with six sensing wells, integrating hydrophobic and hydrophilic regions, hydrophobic parts created through wax. Blood samples are placed in the inlet, dispersing into six sensing wells containing QD-aptamer-AuNP complexes. Target proteins induce conformational changes in aptamers, leading to fluorescence quenching in CdTe QDs. Two wells target p-tau181, two target amyloid beta-42, and two serve as references. Fluorescence emission spectra from each well are recorded, showing a linear correlation between fluorescence quenching and protein concentration. Values from each pair of wells are then averaged, and the average values from the pairs targeting (Aβ-42) and p-tau181 are compared to the average value of the reference wells. This paper-based aptasensor holds promise for early diagnosis of Alzheimer’s Disease and opens the avenue of personalized medicine for the diagnosis of Alzheimer’s.
Widespread parasite infections in living resident killer whales in the Northeast Pacific Ocean
Authors: Mastick Natalie C. , Van Cise A.M. , Parsons K.M. , Ashe E. , Williams R. , Childress J.N. , Nguyen A. , Fearnbach H. , Durban J. , Emmons C. , Hanson B. , Olsen D. , Wood C.L.
Published: July 2024

Multiple populations of resident ecotype killer whales (Orcinus orca ater) inhabit the Northeast Pacific, but the southern resident killer whale (SRKW) population is the most at-risk. SRKWs were listed as endangered in the United States in 2005 and have since shown little sign of recovery. Several factors have been identified as key threats to this population, and previously published studies suggest the population may be energetically stressed. Underlying health risks, such as parasitism, may be contributing to this population’s failure to recover, but little is known about parasite infections in living individuals from natural killer whale populations. To assess the prevalence of internal parasite infections in Northeastern Pacific killer whales, we examined scat from endangered SRKW (n = 25) compared to two conspecific populations of resident killer whales that are not in decline: northern resident (NRKW, n = 2) and southern Alaska resident killer whales (SARKW, n = 7), and one offshore killer whale (OKW, n = 1). We analyzed 35 fecal samples collected from 27 wild killer whales using both microscopic identification of parasite eggs and genetic detection of parasites through DNA metabarcoding. We used body condition indices derived from concurrent aerial photogrammetry to evaluate whether parasite infection status was associated with individual body condition. We found that most individuals sampled (94%) were positive forAnisakisspp. – a parasitic nematode known to inhabit the intestines of cetaceans. These infections were detected across populations, and were not correlated with body condition, based on limited paired data. These results suggest thatAnisakisinfection is widespread among resident killer whales of the Northeast Pacific. The widespread detections of Anisakis among the samples examined here emphasizes the need for further work to understand the potential health impacts of parasitic infections on individual killer whales, and potential synergistic effects with other environmental stressors.
Comparisons of Tree Damage Indicators in Five NASA ABoVE Forest Sites Near Fairbanks, Alaska
Authors: Huebner Diane C. , Potter Christopher S.
Published: July 2024

As global warming affects sensitive northern regions, forests near Fairbanks, Alaska may be undergoing attack from pests and pathogens that could impact their ability to store carbon. Visual tree surveys are quick and useful for assessing forest health in remote sensing studies using GT (ground-truthing). Initial spectral analysis of leaf pigments, canopy water content, and non-photosynthetic carbon of one site near Fairbanks, Alaska imaged with AVIRIS-NG by NASA for the Arctic and Boreal Vulnerability Experiment (ABoVE) showed high fire fuel loads in 2017 that burned in 2019. In 2021-2022 we visually assayed damage of 359 deciduous and 309 coniferous trees at five ABoVE sites of different moisture regimes and burn severities. Using indices of 0 - 5 (0 = healthy, 5 = severe damage) we calculated average damage per tree from: 1) leaf damage (holes or defoliation); 2) stem damage (changes in stem color, texture, growth, heartwood, sap ooze, or stem loss); 3) non-photosynthetic tissue, aka “browning”; and 4) wilting. We also characterized crown color tree-1. Least squares models found low overall average tree damage, but damage types were varied and complex. Deciduous trees suffered greater herbivore damage than conifers. A third of trees showed broadleaf insect damage, a tenth of trees across species showed stem damage associated with pathogens. Aspen and conifers showed heartwood rot, but we found no visual signs of spruce beetle at our sites. Structural equation models found greater stem damage and wilting in warmer soils and post-burned sites supporting seedlings. Browning was associated with understory branches of conifers in late-successional sites with colder, shallower soils. Our study suggests that deciduous trees and seedlings near Fairbanks, Alaska are experiencing herbivory and midsummer wilting, and conifer understory browning is common.
Avirulence depletion assay: combiningRgene-mediated selection with bulk sequencing for rapid avirulence gene identification in wheat powdery mildew
Authors: Kunz Lukas , Jigisha Jigisha , Menardo Fabrizio , Sotiropoulos Alexandros G. , Zbinden Helen , Zou Shenghao , Tang Dingzhong , Hückelhoven Ralph , Keller Beat , Müller Marion C.
Published: July 2024

Wheat production is threatened by multiple fungal pathogens, such as the wheat powdery mildew fungus (Blumeria graminisf. sp.tritici,Bgt). Wheat resistance breeding frequently relies on the use of resistance (R) genes that encode diverse immune receptors which detect specific avirulence (AVR) effectors and subsequently induce an immune response. WhileRgene cloning has accelerated recently,AVRidentification in many pathogens includingBgtlags behind, preventing pathogen-informed deployment of resistance sources. Here we describe a new “avirulence depletion (AD) assay” for rapid identification ofAVRgenes inBgt. This assay relies on the selection of a segregating, haploid F1 progeny population on a resistant host, followed by bulk sequencing, thereby allowing rapid avirulence candidate gene identification with high mapping resolution. In a proof-of- concept experiment we mapped theAVRcomponent of the wheat immune receptorPm3ato a 25kb genomic interval inBgtharboring a single effector, the previously describedAvrPm3a2/f2. Subsequently, we applied the AD assay to map the unknownAVReffector recognized by the Pm60 immune receptor. We show thatAvrPm60is encoded by three tandemly arrayed, nearly identical effector genes that trigger an immune response upon co- expression withPm60and its allelesPm60aandPm60b. We furthermore provide evidence thatPm60outperformsPm60aandPm60bthrough more efficient recognition ofAvrPm60effectors, suggesting it should be prioritized for wheat breeding. Finally, we show that virulence towardsPm60is caused by simultaneous deletion of allAvrPm60gene paralogs and that isolates lackingAvrPm60are especially prevalent in the US thereby limiting the potential ofPm60in this region. The AD assay is a powerful new tool for rapid and inexpensiveAVRidentification inBgtwith the potential to contribute to pathogen-informed breeding decisions for the use of novelRgenes and regionally tailored gene deployment.
A linear ontogeny accounts for the development of naive, memory and tumour-infiltrating regulatory T cells in mice
Authors: Pathak Sanmoy , Hogan Thea , Rane Sanket , Huang Yundi , Sinclair Charles , Barry Simon , Carnevalli Larissa , Yates Andrew , Seddon Benedict
Published: July 2024

Foxp3+Regulatory T cells (Treg) are a subset of CD4+T cells that play critical functions in maintaining tolerance to self antigens and suppressing autoimmunity, regulating immune responses to pathogens and have a role in the pathophysiology of anti-tumoural immunity. Treg ontogeny is complex since they are generated following recognition of self antigens in the thymus during normal T cell development (thymic Treg), but are also induced from mature conventional T cells when activated by foreign antigen with appropriate additional cues (inducible Treg). How these distinct ontogenic pathways contribute to the maintenance and function of the mature Treg compartment in health and disease remains unclear. Here, we use a combination of fate mapping approaches in mice to map the ontogeny of Treg subsets throughout life and estimate rates of production, loss and self-renewal. We find that naive and effector/memory (EM) Treg subsets exhibit distinct dynamics but are both continuously replenished by de novo generation throughout life. Using an inducible Foxp3-dependentCrefate reporter system, we show that naive Treg and not conventional T cells, are the predominant precursors of EM Treg in adults. Tonic development of new EM Treg is not influenced by foreign antigens from commensals, rather suggesting a role for self recognition. To investigate the ontogeny of Treg development in malignant disease, we used the same fate reporter systems to characterise the Treg infiltrate of three different model tumours. In all three cases, we found that Treg derived from pre-existing, EM Treg. Together, these results reveal a predominantly linear pathway of Treg development from thymic origin to EM Treg associated with pathophysiology of malignant disease, that is driven by self antigen recognition throughout.
Quantifying seed rain patterns in a remnant and a chronosequence of restored tallgrass prairies in north central Missouri
Authors: Wynne K. Carter , Parker-Smith Maya J. , Murdock Erica M. , Sullivan Lauren L.
Published: July 2024

Seed rain is an influential process related to plant community diversity, composition, and regeneration. However, knowledge of seed rain patterns is limited to those observed in forests and late-assembling grasslands, which might not reflect early-assembling communities such as newly restored grasslands. Resolving this gap in our understanding provides further insight into the role of seed dispersal.

Here, we measured seed rain in a remnant tallgrass prairie, which was the site of the foundational grassland seed rain study in 1978, and a nearby chronosequence of tallgrass prairie restorations. We sought to determine how the quantity, seed mass traits, timing, diversity, and composition of seed rain changed (1) long-term and (2) during community assembly. To do so, we deployed artificial turf grass seed traps into 2-year-old, 5-6-year-old, and 15-year-old restored prairies and the remnant prairie, replacing traps every two weeks from May to December 2019.

We captured over twice the density and richness of seed rain in the remnant prairie in 2019 compared to 1978. We also found that seed rain patterns changed as prairies aged, with each prairie possessing a distinct community of dispersing species. Significantly more seeds, seed biomass, and species were captured in the youngest restored prairie. However, seed mass traits were similar in all prairies. Except for composition, all other seed rain metrics in the oldest restoration were eventually comparable to the remnant prairie.

Synthesis and Applications: Our results revealed that grasslands, notably young prairies, produce larger quantities of seed rain than previously known (124,806 seeds m−2year−1, 97.24 g m−2year−1), and seed input in all sampled prairies far exceeded restoration broadcast seeding densities. We further found that decreases in seed rain quantity across the chronosequence did not correspond with increases in seed mass, suggesting a lack of tradeoffs between these metrics. Furthermore, tallgrass prairie restorations have not replicated the composition of seed rain seen in remnant systems. Increasing restoration seeding rates of desirable species may be needed to meet composition goals since current rates may not compete with the propagule pressure of undesirable species found in newly restored prairies.
Tempo-dependent selective enhancement of neural responses at the beat frequency can be explained by both an oscillator and an evoked model
Authors: Damsma Atser , de Roo Mitchell , Doelling Keith , Bazin Pierre-Louis , Bouwer Fleur L.
Published: July 2024

A crucial mechanism for the brain to make sense of the auditory environment is the synchronization of neural responses to external temporal regularities, such as a musical beat. It is debated whether this synchronization and the resulting beat percept reflect phase alignment of endogenous neural oscillations to the external regularity (entrainment), or evoked responses to the rhythmic stimulus (tracking). Here, we use the tempo-dependent properties of beat processing to differentiate between the two accounts. Behaviorally, we show a shift in the perceived level of regularity towards the preferred beat rate (around 2 Hz) when listening to rhythmic patterns at different speeds. We found a similar shift in EEG data, where the hierarchical level in the rhythms at which neural synchronization was strongest depended on tempo. This selective enhancement is consistent with entrainment accounts and could indeed be mimicked by an oscillator model. However, importantly, the results were explained equally well using a model simulating evoked responses. Together, our findings demonstrate that while neural responses to rhythm are selectively enhanced at the beat rate, this enhancement need not be taken as evidence for entrainment, but can also be explained by successive evoked responses.
APP β-CTF triggers cell-autonomous synaptic toxicity independent of Aβ
Authors: Luo Mengxun , Zhou Jia , Sun Cailu , Chen Wanjia , Fu Chaoying , Si Chenfang , Zhang Yaoyang , Geng Yang , Chen Yelin
Published: July 2024

Aβ is believed to play a significant role in synaptic degeneration observed in Alzheimer’s disease (AD) and is primarily investigated as a secreted peptide. However, the contribution of intracellular Aβ or other cleavage products of its precursor protein (APP) to synaptic loss remains uncertain. In this study, we conducted a systematic examination of their cell-autonomous impact using a sparse expression system. Here, these proteins/peptides were overexpressed in a single neuron, surrounded by thousands of untransfected neurons. Surprisingly, we found that APP induced dendritic spine loss only when co-expressed with BACE1. This effect was mediated by β-CTF, a β-cleavage product of APP, through an endosome-related pathway independent of Aβ. Neuronal expression of β-CTF in mouse brains resulted in defective synaptic transmission and cognitive impairments, even in the absence of amyloid plaques. These findings unveil a β-CTF-initiated mechanism driving synaptic toxicity irrespective of amyloid plaque formation and suggest a potential intervention by inhibiting the endosomal GTPase Rab5.
Chaotic synchronization in adaptive networks of pulse-coupled oscillators
Authors: Mato Germán , Politi Antonio , Torcini Alessandro
Published: July 2024

Ensembles of phase-oscillators are known to exhibit a variety of collective regimes. Here, we show that a simple mean-field model involving two heterogenous populations of pulse-coupled oscillators, exhibits, in the strong-coupling limit, a robust irregular macroscopic dynamics. The resulting, strongly synchronized, regime is sustained by a homeostatic mechanism induced by the shape of the phase-response curve combined with adaptive coupling strength, included to account for energy dissipated by the pulse emission. The proposed setup mimicks a neural network composed of excitatory and inhibitory neurons.
An off-lattice discrete model to characterise filamentous yeast colony morphology
Authors: Li Kai , Green J. Edward F. , Tronnolone Hayden , Tam Alexander K. Y. , Black Andrew J. , Gardner Jennifer M. , Sundstrom Joanna F. , Jiranek Vladimir , Binder Benjamin J.
Published: July 2024

We combine an off-lattice agent-based mathematical model and experimentation to explore filamentous growth of a yeast colony. Under environmental stress,Saccharomyces cerevisiaeyeast cells can transition from a bipolar (sated) to unipolar (pseudohyphal) budding mechanism, where cells elongate and bud end-to-end. This budding asymmetry yields spatially non-uniform growth, where filaments extend away from the colony centre, foraging for food. We use approximate Bayesian computation to quantify how individual cell budding mechanisms give rise to spatial patterns observed in experiments. We apply this method of parameter inference to experimental images of colonies of two strains ofS. cerevisiae, in low and high nutrient environments. The initial nutrient concentration and a forking mechanism for pseudohyphal cell proliferation are the key features driving colony morphology. Simulations run with the most likely inferred parameters produce colony morphologies that closely resemble experimental results.
Enzymatic carbon-fluorine bond cleavage by human gut microbes
Authors: Probst Silke I. , Felder Florian D. , Poltorak Victoria , Mewalal Ritesh , Blaby Ian K. , Robinson Serina L.
Published: July 2024

Fluorinated compounds are used for agrochemical, pharmaceutical, and numerous industrial applications, resulting in global contamination. In many molecules, fluorine is incorporated to enhance the half-life and improve bioavailability. Fluorinated compounds enter the human body through food, water, and xenobiotics including pharmaceuticals, exposing gut microbes to these substances. The human gut microbiota is known for its xenobiotic biotransformation capabilities, but it was not previously known whether gut microbial enzymes could break carbon-fluorine bonds, potentially altering the toxicity of these compounds.

Here, through the development of a rapid, miniaturized fluoride detection assay for whole-cell screening, we discovered active gut microbial defluorinases. We biochemically characterized enzymes from diverse human gut microbial classes including Clostridia, Bacilli, and Coriobacteriia, with the capacity to hydrolyze (di)fluorinated organic acids and a fluorinated amino acid. Whole-protein alanine scanning, molecular dynamics simulations, and chimeric protein design enabled the identification of a disordered C-terminal protein segment involved in defluorination activity. Domain swapping exclusively of the C-terminus conferred defluorination activity to a non-defluorinating dehalogenase. To advance our understanding of the structural and sequence differences between defluorinating and non-defluorinating dehalogenases, we trained machine learning models which identified protein termini as important features. Models trained on 41-amino acid segments from protein C-termini alone predicted defluorination activity with 83% accuracy (compared to 95% accuracy based on full-length protein features). This work is relevant for therapeutic interventions and environmental and human health by uncovering specificity-determining signatures of fluorine biochemistry from the gut microbiome.

Significance

Humans have introduced carbon-fluorine bonds into numerous manufactured compounds, including pharmaceuticals, leading to the formation of toxic fluorinated byproducts. While the human gut microbiota is known for its ability to metabolize drugs, its encoded capacity to break the strong carbon-fluorine chemical bond was previously unknown. Here we discovered that human gut microbial enzymes are capable of cleaving carbon-fluorine bonds. We developed a 96-well colorimetric fluoride assay amenable to bacterial culture-based screening. Additionally, we trained machine learning models to predict defluorination activity and experimentally validated our findings to identify key features of defluorinating enzymes. This opens new research directions in microbiome research for the metabolism of fluorinated compounds, with implications for therapeutic development and enzyme engineering to break carbon-fluorine bonds.
Protein quality control modulates the metabolic conservation in antibiotic tolerantCampylobacter jejuni
Authors: Feng Jinsong , Li Shenmiao , Hu Yaxi , Stahl Martin , Ma Lina , Knuff-Janzen Katelyn , Wang Kaidi , Hua Marti Z. , Vallance Bruce A. , Konkel Michael E. , Finlay B. Brett , Lu Xiaonan
Published: July 2024

Antibiotic tolerance in bacteria emerges as a phenotypic variant known as persisters and has been implicated in recurrent bacterial infections. This tolerance manifests as suppressed metabolism. We demonstrate thatCampylobacter jejunireadily forms persisters in response to both ampicillin and ciprofloxacin. Persisters induced by these two antibiotics with different mechanisms of actions experience consistent metabolic reprogramming, characterized by suppressed respiration and energy metabolism while conserving core metabolic processes. We reveal that the coordination of protein homeostasis underlies the metabolic reprogramming involved in persister formation. Mutating the caseinolytic protease geneclpP, a major component of the protein quality control system, compromises persister formationin vitroand impairs bacterial colonization in mouse. However, the deletion oflon, another component of the protein quality control system, or pre-activation ofclpPby expressing artificial disordered protein fragments does not affect the antibiotic tolerance. This suggests that specific targets of ClpP rather than the entire quality control system are critical for persister formation. Our results reveal a convergent metabolic reprogramming in persisters, highlighting the potential to limit the emergence of antibiotic tolerance by counteracting adaptive metabolism elicited by antibiotic treatment.
Local nuclear to cytoplasmic ratio regulates H3.3 incorporation via cell cycle state during zygotic genome activation
Authors: Bhatt Anusha D. , Brown Madeleine G. , Wackford Aurora B. , Shindo Yuki , Amodeo Amanda A.
Published: July 2024

Early embryos often have unique chromatin states prior to zygotic genome activation (ZGA). InDrosophila, ZGA occurs after 13 reductive nuclear divisions during which the nuclear to cytoplasmic (N/C) ratio grows exponentially. Previous work found that histone H3 chromatin incorporation decreases while its variant H3.3 increases leading up to ZGA. In other cell types, H3.3 is associated with sites of active transcription and heterochromatin, suggesting a link between H3.3 and ZGA. Here, we test what factors regulate H3.3 incorporation at ZGA. We find that H3 nuclear availability falls more rapidly than H3.3 leading up to ZGA. We generate H3/H3.3 chimeric proteins at the endogenous H3.3A locus and observe that chaperone binding, but not gene structure, regulates H3.3 behavior. We identify the N/C ratio as a major determinant of H3.3 incorporation. To isolate how the N/C ratio regulates H3.3 incorporation we test the roles of genomic content, zygotic transcription, and cell cycle state. We determine that cell cycle regulation, but not H3 availability or transcription, controls H3.3 incorporation. Overall, we propose that local N/C ratios control histone variant usage via cell cycle state during ZGA.
Crystal structures of lanthanum to 230 GPa
Authors: Storm C. V. , Roy C. R. , Munro K. A. , McMahon M. I.
Published: July 2024

The structural behavior of lanthanum metal has been investigated up to 227 GPa using synchrotron x-ray diffraction. Rather than having the rhombohedral or orthorhombic structures previously reported to be stable above 80 GPa, we find that La adopts the tetragonal tI2 structure seen previously in Ce and Pr. We show that the recent claims of a rhombohedral structure arose from the misidentification of lanthanum hydride peaks. The revised pressure dependence of the atomic volume of La above 100 GPa further constrains the stoichiometry of the superconducting LaH10 superhydride, which is synthesized from La above 160 GPa.

Published by the American Physical Society
2024
Structure of heavy mesons in the light-front quark model
Authors: Arifi Ahmad Jafar , Happ Lucas , Ohno Shuhei , Oka Makoto
Published: July 2024

We investigate the structure of ground-state heavy mesons within the light-front quark model, utilizing wave functions derived from the single Gaussian ansatz (SGA) and the Gaussian expansion method (GEM). By performing a χ2 fit to static properties such as mass spectra and decay constants, we determine the model parameters for each approach. We then compare the impacts of both methods on the light-front wave functions and structural observables. Our analysis reveals significant differences in the distribution amplitudes ϕ2;M(x) near the end points, with GEM showing enhanced amplitudes and correct asymptotic behavior ϕ2;M(x→1)∝(1−x), consistent with perturbative QCD. This end point behavior is linked to the short-range (high-momentum) wave function governed by color Coulomb interaction and relativistic kinematics. GEM accurately reproduces a power-law damping ψ0(k→∞)∝1/k⊥2, aligning with perturbative QCD predictions. Furthermore, the electromagnetic form factors of pseudoscalar mesons in the low-Q2 region fall off faster with GEM than with SGA. Overall, while both methods adequately describe static properties, GEM provides a more accurate description of structural properties, being more sensitive to details and asymptotic behaviors.

Published by the American Physical Society
2024
Actin Filament Barbed-End Depolymerization by Combined Action of Profilin, Cofilin, and Twinfilin
Authors: Arya Ankita , Choubey Sandeep , Shekhar Shashank
Published: July 2024

Cellular actin dynamics results from the collective action of hundreds of regulatory proteins, majority of which target actin filaments at their barbed ends. Three key actin binding proteins—profilin, cofilin, and twinfilin—individually depolymerize filament barbed ends. Notwithstanding recent leaps in our understanding of their individual action, how they collectively regulate filament dynamics remains an open question. In the absence of direct and simultaneous visualization of these proteins at barbed ends, gaining mechanistic insights has been challenging. We have here investigated multicomponent dynamics of profilin, cofilin, and twinfilin using a hybrid approach that combines high-throughput single filament experiments with theory. We discovered that while twinfilin competes with profilin, it promotes binding of cofilin to filament sides. Interestingly, contrary to previous expectations, we found that profilin and cofilin can simultaneously bind the same filament barbed end, resulting in its accelerated depolymerization. Our study reveals that pairwise interactions can effectively capture depolymerization dynamics in simultaneous presence of all three proteins. We thus believe that our approach of employing a theory-experiment dialog can potentially help decipher multicomponent regulation of actin dynamics.

Published by the American Physical Society
2024
Dynamic Cooling on Contemporary Quantum Computers
Authors: Bassman Oftelie Lindsay , De Pasquale Antonella , Campisi Michele
Published: July 2024

We study the problem of dynamic cooling whereby a target qubit is cooled at the expense of heating up N−1 further identical qubits by means of a global unitary operation. A standard back-of-the-envelope high-temperature estimate establishes that the target qubit temperature can be dynamically cooled by at most a factor of 1/N. Here we provide the exact expression for the minimum temperature to which the target qubit can be cooled and reveal that there is a crossover from the high initial temperature regime, where the scaling is 1/N, to a low initial temperature regime, where a much faster scaling of 1/N occurs. This slow, 1/N scaling, which was relevant for early high-temperature NMR quantum computers, is the reason dynamic cooling was dismissed as ineffectual around 20 years ago; the fact that current low-temperature quantum computers fall in the fast,

1

/

N

scaling regime, reinstates the appeal of dynamic cooling today. We further show that the associated work cost of cooling is exponentially more advantageous in the low-temperature regime. We discuss the implementation of dynamic cooling in terms of quantum circuits and examine the effects of hardware noise. We successfully demonstrate dynamic cooling in a three-qubit system on a real quantum processor. Since the circuit size grows quickly with N, scaling dynamic cooling to larger systems on noisy devices poses a challenge. We therefore propose a suboptimal cooling algorithm, whereby relinquishing a small amount of cooling capability results in a drastically reduced circuit complexity, greatly facilitating the implementation of dynamic cooling on near-future quantum computers.

Published by the American Physical Society
2024
Structural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluorolactonization products from the reaction of oleanolic acid with SelectfluorTM
Authors: Eadsforth Megan A. , Kong Linghan , Whitehead George , Vitórica-Yrezábal Iñigo J. , O'Keefe Raymond T. , Bryce Richard A. , Whitehead Roger C.
Published: July 2024

The X-ray crystal structure data of 12-α-fluoro-3β-hydroxyolean-28,13β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (1), and 12-α-fluoro-3β-hydroxytaraxer-28,14β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (2), are described. The fluorolactonization of oleanolic acid using SelectfluorTM yielded a mixture of the six-membered δ-lactone (1) and the unusual seven-membered γ-lactone (2) following a 1,2-shift of methyl C-27 from C-14 to C-13.
Crystallographic fragment-binding studies of the Mycobacterium tuberculosis trifunctional enzyme suggest binding pockets for the tails of the acyl-CoA substrates at its active sites and a potential substrate-channeling path between them
Authors: Dalwani Subhadra , Metz Alexander , Huschmann Franziska U. , Weiss Manfred S. , Wierenga Rik K. , Venkatesan Rajaram
Published: July 2024

The Mycobacterium tuberculosis trifunctional enzyme (MtTFE) is an α2β2 tetrameric enzyme in which the α-chain harbors the 2E-enoyl-CoA hydratase (ECH) and 3S-hydroxyacyl-CoA dehydrogenase (HAD) active sites, and the β-chain provides the 3-ketoacyl-CoA thiolase (KAT) active site. Linear, medium-chain and long-chain 2E-enoyl-CoA molecules are the preferred substrates of MtTFE. Previous crystallographic binding and modeling studies identified binding sites for the acyl-CoA substrates at the three active sites, as well as the NAD binding pocket at the HAD active site. These studies also identified three additional CoA binding sites on the surface of MtTFE that are different from the active sites. It has been proposed that one of these additional sites could be of functional relevance for the substrate channeling (by surface crawling) of reaction intermediates between the three active sites. Here, 226 fragments were screened in a crystallographic fragment-binding study of MtTFE crystals, resulting in the structures of 16 MtTFE–fragment complexes. Analysis of the 121 fragment-binding events shows that the ECH active site is the `binding hotspot' for the tested fragments, with 41 binding events. The mode of binding of the fragments bound at the active sites provides additional insight into how the long-chain acyl moiety of the substrates can be accommodated at their proposed binding pockets. In addition, the 20 fragment-binding events between the active sites identify potential transient binding sites of reaction intermediates relevant to the possible channeling of substrates between these active sites. These results provide a basis for further studies to understand the functional relevance of the latter binding sites and to identify substrates for which channeling is crucial.
Familiarity analysis and time-advance experimental study of LP-NGD RC-circuit intended to operate with Unity-normalized gain
Authors: Cui Jun Yan , Silochi Hakim Epea , Wieser1 Robert , Junwen Shi , Bilal Habachi , Ngoho Samuel , Ravelo Blaise
Published: July 2024

Purpose

The purpose of this paper is to develop a familiarity analysis of resistive-capacitive (RC) network active circuit operating with unfamiliar low-pass (LP) type negative group delay (NGD) behavior. The design method of NGD circuit is validated by simulation with commercial tool and experimental measurement.

Design/methodology/approach

The present research work methodology is structured in three main parts. The familiarity theory of RC-network LP-NGD circuit is developed. The LP-NGD circuit parameters are expressed in function of the targeted time-advance. Then, the feasibility study is based on the theory, simulation and measurement result comparisons.

Findings

The RC-network based LP-NGD proof of concept is validated with −1 and −0.5 ms targeted time-advances after design, simulation, test and characterized. The LP-NGD circuit unity gain prototype presents NGD cut-off frequencies of about 269 and 569 Hz for the targeted time-advances, −1 and −0.5 ms, respectively. Bi-exponential and arbitrary waveform signals were tested to verify the targeted time-advance.

Research limitations/implications

The performance of the unfamiliar LP-NGD topology developed in the present study is limited by the parasitic elements of constituting lumped components.

Practical implications

The NGD circuit enables to naturally reduce the undesired delay effect from the electronic and communication systems. The NGD circuit can be exploited to reduce the delay induced by electronic devices and system.

Social implications

As social impacts of the NGD circuit application, the NGD function is one of prominent solutions to improve the technology performances of future electronic device in term of communication aspect and the transportation system.

Originality/value

The originality of the paper concerns the theoretical approach of the RC-network parameters in function of the targeted time-advance and the input signal bandwidth. In addition, the experimental results are also particularly original.
Tackling inventory losses of small accessories in engineering manufacturing: a case study of Euro Manufacturing
Authors: Shaikh Abdul Rehman , Mirani Manzoor Ali , Ali Saqib
Published: July 2024

Learning outcomes

After completion of the case study, the students will be able to understand ABC analysis and develop a systematic approach using PDCA, analyze processes, technology, employee training and supplier relationships when analyzing shrink and developing solutions, evaluate how technology improves production inventory control and visibility and recognize the importance of fostering a culture of employee accountability and ownership to minimize inventory loss and improve overall operational efficiency.

Case overview/synopsis

On June 2, 2023, sitting in his office in Karachi, Pakistan, Khan Aamir, the manager of store and inventory at Euro Manufacturing, found himself immersed in a cloud of confusion. The incessant loss of inventory items, particularly the nut bolts and small accessories, had become a perplexing challenge. To address these losses and provide a cycle count report to the director of supply chain, Aamir, manager of store and inventory, was given the responsibility to take action. He was looking for a comprehensive approach to address the current problems and prevent further losses in the future. This case study examines the various reasons for the losses, including theft, inadequate inventory control methods, human error and problems with suppliers. It highlights the importance of established procedures, the use of technology (such as barcode scanning, radio-frequency identification tagging and inventory management software) and the cultivation of a culture of accountability among employees.

Complexity academic level

This case study is developed for class discussion in the course of operations management or supply chain management. This case study is suitable for use with undergrad students. This case study can be taught in a module on operations management or supply chain management, as part of a broader course in business management or industrial engineering.

Supplementary materials

Teaching notes are available for educators only.

Subject code

CSS: 9: Operations and logistics.
Research on the construction and application of a smart library services maturity evaluation system based on CMM
Authors: Bai Zhongxian , Yu Lvna , Zhao Lei , Wang Weijia
Published: July 2024

Purpose

Smart libraries are the result of the application of smart technologies in the era of digital intelligence. The establishment and improvement of its service evaluation system serve as indicators for evaluating the growth of smart libraries.

Design/methodology/approach

This study introduces and improves the capability maturity model (CMM), creatively constructs a service maturity model specifically designed for smart libraries and combines the Delphi method with the analytic hierarchy process (AHP) to establish a service maturity evaluation system for smart libraries while calculating indicator weights. Finally, two representative smart libraries are selected as case studies, and an empirical application is conducted using the fuzzy comprehensive evaluation method.

Findings

The empirical study shows that the developed smart libraries service maturity evaluation system holds significant theoretical and practical value in evaluating smart libraries.

Originality/value

Enhances the CMM and creatively constructs a service maturity model for smart libraries. Combines the Delphi method with AHP to establish a service maturity evaluation system while calculating indicator weights. Uses a fuzzy comprehensive evaluation method to evaluate two representative smart libraries. Demonstrates that the smart library services maturity evaluation system holds significant theoretical and practical value.
Mitigating work alienation in public sector service-delivery projects caused by perceived overqualification: the roles of empowering leadership and the psychological contracts
Authors: Alvi Tariq Hameed , Ilyas Hafiz Muhammad Siddaq , Tariq Samia , Qammar Ahmad , Wang Yonggui
Published: July 2024

Purpose

The study investigates the nature of an understudied yet salient relationship between perceived overqualification (POQ) and work alienation in project management. It employs relative deprivation theory to propose two dimensions of the psychological contract, i.e. relational and transactional, as underlying mediating mechanisms and how empowering leadership mitigates the adverse effects of POQ.

Design/methodology/approach

To this end, in two waves, we surveyed 232 project members of three public-sector information and communication technologies (ICT) projects in Punjab, Pakistan. The data was analyzed using Partial Least Square Structural Equation Modeling (PLS-SEM).

Findings

The key findings are: (1) POQ leads to work alienation, (2) relational and transactional contracts mediate this relationship, and (3) empowering leadership can mitigate the adverse effects of POQ in project management settings.

Originality/value

This research adds valuable insights to the scant POQ literature in public-sector project management settings. It also contributes by identifying the mediating role of relational and transactional psychological contracts and the moderating role of empowering leadership to mitigate the adverse effects of POQ in these settings.
Voluntary presenteeism: through the lens of employee engagement
Authors: Rawat Preeti S. , Lyndon Shiji S. , Darvekar Shivali
Published: July 2024

Purpose

The purpose of the study is to give a new perspective to presenteeism. Traditionally, there are two approaches to it. In our study, we have tried to empirically prove that there is a third approach to looking at presenteeism from the lens of employee engagement.

Design/methodology/approach

The research design used a mixed-method approach and was carried out in two parts. In Part I of the study, survey research was carried out to study presenteeism. In part II, a vignette on presenteeism was designed to study whether respondents exhibit presenteeism more in a crisis than other modes of handling the situation.

Findings

The findings from Study 1 showed that high employee engagement led to high presenteeism. Study 2 showed that in crisis situation employee engagement led to voluntary presenteeism in the form of work–from–home as the most preferred response.

Research limitations/implications

The study's limitations were the small sample size and cross-sectional survey research design. The same was offset by using the vignette study to show the relationship between employee engagement and presenteeism.

Practical implications

Voluntary presenteeism is different from forced presenteeism and often is a mark of engaged behaviour of employees.

Social implications

If work-from-home when sick is managed correctly and supported with adequate resources, attending work during illness can benefit health and performance in the long run.

Originality/value

The study provides a unique perspective on presenteeism in general and voluntary presenteeism in particular.
Decoding tourist perceptions and behavioral intentions to use electric vehicles for sustainable tourism with the lens of technology continuance theory
Authors: Prakhar Prakhar , Jaiswal Rachana , Gupta Shashank , Gupta Shiv Kumar
Published: July 2024

Purpose

This study aims to explore tourist perceptions and behaviors toward electric vehicles (EVs) in the Delhi National Capital Region using the technology continuance theory.

Design/methodology/approach

An online survey involving 226 respondents uses structural equation modeling to analyze correlations among factors, including perceived enjoyment, facilitating conditions, ease of use, satisfaction, cost, image and performance.

Findings

This study reveals that enhancing perceived enjoyment and facilitating conditions can improve the user-friendliness of EVs. Additionally, reducing perceived cost, enhancing image and improving perceived performance can increase the perceived usefulness of EVs. Perceived ease of use strongly influences user satisfaction, while perceived usefulness and satisfaction positively impact users’ attitudes and intentions to use EVs. Although factors such as experience, environmental consciousness, age and gender influence perceptions, focusing on enjoyment, facilitating conditions, cost, image and performance can significantly enhance user satisfaction and intention to use EVs.

Research limitations/implications

The findings underscore several actionable recommendations for businesses and policymakers to boost EV adoption at tourist destinations. The potential benefits of EV adoption, such as improved environmental sustainability, enhanced technological image and increased tourist satisfaction, can serve as a source of inspiration and motivation. Enhancing user experience by prioritizing comfort and convenience in EV design is crucial. Addressing cost concerns through incentives and cost-effective pricing strategies can make EVs more appealing. Marketing campaigns highlighting environmental benefits and technological advancements can improve EV image and performance perception. Prioritizing tourists’ satisfaction and support services is essential, along with educational campaigns to increase awareness. Infrastructure development, including expanding charging networks, and supportive policies like tax incentives, can further encourage EVs adoption, accelerating the transition to sustainable transportation.

Originality/value

This research contributes to understanding tourist perspectives on EV adoption within the context of sustainable tourism and technology adoption.