bluuebunny/crossref_metadata_2025 huggingface dataset:
Building a syntrophicPseudomonas putidaconsortium with reciprocal substrate processing of lignocellulosic disaccharides
Authors: Burýšková Barbora , Miró-Bueno Jesús , Popelářová Barbora , Gavendová Barbora , Goñi-Moreno Ángel , Dvořák Pavel
Published: November 2024

Synthetic microbial consortia can leverage their expanded enzymatic reach to tackle biotechnological challenges too complex for single strains, such as lignocellulose valorisation. The benefit of metabolic cooperation comes with a catch – installing stable interactions between consortium members. We constructed a syntrophic consortium ofPseudomonas putidastrains for lignocellulosic disaccharide processing. Two strains were engineered to hydrolyse and metabolise lignocellulosic sugars: one grows on xylose and hydrolyses cellobiose to produce glucose, while the other grows on glucose and cleaves xylobiose to produce xylose. This specialisation allows each strain to provide essential growth substrate to its partner, establishing a stable mutualistic interaction, which we term reciprocal substrate processing. Key enzymes fromEscherichia coli(xylose isomerase pathway) andThermobifida fusca(glycoside hydrolases) were introduced intoP. putidato broaden its carbohydrate utilisation capabilities and arranged in a way to install the strain cross-dependency. A mathematical model of the consortium assisted in predicting the effects of substrate composition, strain ratios, and protein expression levels on population dynamics. Our results demonstrated that modulating extrinsic factors such as substrate concentration can optimise growth and balance fitness disparities between the strains, but achieving this by altering intrinsic factors such as glycoside hydrolase expression levels is much more challenging. This study underscores the potential of synthetic microbial consortia to facilitate the bioconversion of lignocellulosic sugars and offers insights into overcoming the challenges of establishing synthetic microbial cooperation.
Global and selective effects of auditory attention on arousal: insights from pupil dilation
Authors: Aurélie Grandjean , Hoyer Roxane S. , Anne Mathieu , Anne Caclin , Annie Moulin , Aurélie Bidet-Caulet
Published: November 2024

This study investigated the interplay between attention and arousal in humans by measuring pupil dilation as a function of task engagement and stimulus relevance. Arousal in response to task-relevant and unexpected irrelevant sounds was measured in healthy young adults during the performance of an auditory detection task, the Competitive Attention Test, and in sensory matched passive conditions. Attention was manipulated using informative and uninformative visual cues. Both relevant and irrelevant sounds elicited a larger increase in pupil dilation in the active compared to the passive condition, revealing a global effect of task engagement on arousal. Additionally, in the active condition, the pupil dilation amplitude during the anticipation and detection of the task-relevant sound was greater following an informative compared to an uninformative cue, while no cue effect was found on the pupil dilation response to distracting sounds. This finding suggests that arousal can be selectively enhanced by attention for task-relevant, but not -irrelevant, events.
Development of a p62 biodegrader for autophagy targeted degradation
Authors: Thiel Zacharias , Marcellin David , Manneville Carole , Goretzki Benedikt , Egger Luca , Maher Rob , Siccardi Noémie , Sansig Gilles , Torres Laura , Probst Alexandra , Müller Catrin Swantje , George Nathalie , Vogel Markus , Sinterhauf Sabine , Lavoisier Alexandra , Choi Ji-Young , Forcellino Laurianne , Hauck Patrick , Be Celine , Villard Frédéric , Gutmann Sascha , Meyer Marc , Freuler Felix , Patoor Maude , Mitchell Gabriel , Nyfeler Beat
Published: November 2024

Harnessing autophagy for targeted degradation is a promising extension to proteasome-based targeted protein degradation because of the capacity and versatility of lysosomes to degrade large and complex cargo, thus broadening the scope of therapeutic targets. While small-molecule degraders recruiting the autophagy machinery to targets are starting to emerge, it remains unclear which component of the autophagy lysosomal pathway is most efficacious to induce selective target degradation. Here, we describe two orthogonal induced-proximity strategies to identify and prioritize autophagy effectors that are sufficient to degrade organelles as well as soluble targets. We show that induced proximity of different effectors such as autophagy cargo receptors, ATG8-like proteins or the kinases ULK1 and TBK1 are sufficient to trigger mitophagy. In contrast, self-oligomerizing autophagy cargo receptors outperform ATG8- like effectors and autophagy-related kinases in clearing a soluble cytosolic protein. We further explore the importance of avidity for targeted degradation via autophagy and reveal that the PB1 domain of p62 fused to a LIR peptide is a minimal degron to induce the degradation of mitochondria as well as cytosolic proteins. By developing a novel and highly selective intrabody against the autophagy cargo receptor p62 into a heterobifunctional degrader, we demonstrate that recruitment of endogenous p62 is sufficient to clear mitochondria. This biodegrader, however, is unable to induce degradation of soluble cytosolic proteins due to its inhibitory effect on p62 self-oligomerization. Our study highlights the importance of avidity and suggests that autophagy cargo receptors are attractive entry points for the development of heterobifunctional degraders for complex targets such as organelles or protein aggregates.
Id1Promotes Clonal Hematopoiesis in Mice withTet2Loss of Function
Authors: Singh Shweta , Sarkar Tanmoy , Gudmundsson Kristbjorn O. , Jakubison Brad L. , Morris Holly M. , Burkett Sandra , Baktiar Karim , Pauly Gary T. , Sigano Dina M. , Schneider Joel P. , Keller Jonathan R.
Published: November 2024

Hematopoietic malignancies emerge through the gradual acquisition of genetic mutations within hematopoietic stem and progenitor cells (HSPCs). Mutations that occur early in disease progression impart a selective growth advantage to HSPCs, which allows them to expand and contribute to a substantial percentage of mature blood cells. This increased expansion is termed clonal hematopoiesis (CH) and is a preleukemic phase associated with an increased risk of developing leukemia. Inhibitor of DNA binding 1 (ID1) protein is a transcriptional regulator of proliferation/differentiation of neuronal, muscle, hematopoietic and other cells, and is frequently overexpressed in cancer.Id1is expressed at low levels in normal HSCs and is induced by growth factors and other mediators of inflammatory stress and promotes HSPC proliferationin vitro and in vivo.Since chronic inflammation is associated with the progression of hematopoietic malignancies, reducingId1expression during CH may be therapeutic. Mutations inTET2are frequently observed in patients with CH, andTet2−/−mice develop CH that progress to hematopoietic malignancies.Id1is upregulated in murineTet2−/−HSPCs and in AML, CMML and MDS patient samples withTET2mutations. Genetic ablation ofId1inTet2−/−HSPCs reduces HSPC expansion/self-renewal/CH, extramedullary hematopoiesis, myeloid skewing, genetic instability and delays the onset of disease. Mechanistically, p16 expression, senescence and apoptosis were increased and proliferation decreased inTet2−/−; Id1−/−HSPCs. Thus, ID1 may represent a potential therapeutic target to reduce CH, hematopoietic hyperplasia, and delay the onset of disease.

One Sentence Summary

Genetic ablation ofId1inTet2−/−mice rescues clonal hematopoiesis by increasing CDKI expression, apoptosis, senescence, and differentiation, and reducing cell growth.
Gellan gum-based nutrient medium increases the diversity of cultivated groups of soil microorganisms
Authors: Borisovna Kulikova Daria , Alekseevich Demin Konstantin , Valerievna Prazdnova Evgenia , Sergeevna Mazanko Maria , Pavlovich Kulikov Maksim
Published: November 2024

Soil microbial communities contain a huge proportion of microorganisms that cannot be cultured on standard microbiological media and are available for study only by molecular methods such as metagenomics. Among them may be found microorganisms-producers of biologically active substances useful for medicine, biotechnology and agricultural activities of humans. Development of approaches for cultivation of such groups may open the way to the creation of fundamentally new antibiotic, antitumor drugs, phyto- and immunostimulants. We have proposed a solid oligotrophic medium for cultivation of soil microorganisms containing gellan gum, which allows to obtain cultures of more rare microorganisms compared to known media. Representatives of phylum Chloroflexota, Deinococcota, Planctomycetota, Actinomycetota, which were absent on agar media, were found in the metagenome of the community grown on this medium
Excess weight increases the risk for neurological and neuropsychiatric symptoms in post-COVID-19 condition: A systematic review and meta-analysis
Authors: Ronca Débora Barbosa , Mesquita Larissa Otaviano , Oliveira Dryelle , Figueiredo Ana Cláudia Morais Godoy , Wen Jun , Song Manshu , de Carvalho Kênia Mara Baiocchi
Published: November 2024

Background/purpose: Excess weight has been identified as a potential risk factor for the development of post-COVID-19 condition (PCC). This review investigates whether excess weight increases the risk of neurological and neuropsychiatric symptoms associated with PCC.Methods: Studies published up to July 2023 were searched independently across eight electronic databases to evaluate the risk of developing neurological and neuropsychiatric symptoms more than 12 weeks post-infection between exposure and controls groups (excess weightvs.normal weight; obesityvs.non-obesity). Meta-analyses were conducted under a random-effects model.Results:Of the 10,122 abstracts screened, 18 studies (n= 139,091 adults) met the inclusion criteria and reported PCC symptoms according to nutritional status. These studies included 79,050 individuals with excess weightvs57,926 normal-weight individuals and 30,694 individuals with obesityvs107,612 non-obese individuals. The presence of excess weight in PCC significantly increased the risk of depression (RR = 1.21; 95% CI: 1.03–1.42), headache (RR = 1.21; 95% CI: 1.09–1.35), memory issues (RR = 1.43; 95% CI: 1.24–1.65), sleep disturbance (RR = 1.31; 95% CI: 1.16–1.48), and vertigo (RR = 1.21; 95% CI: 1.04– 1.41). Obesity significantly increased the risk of headache (RR = 1.41; 95% CI: 1.34– 1.49), smell disorder (RR = 1.15; 95% CI: 1.09–1.21), taste disorder (RR = 1.21; 95% CI: 1.07–1.36), and vertigo (RR = 1.44; 95% CI: 1.35–1.53).Conclusions:Excess weight or obesity increases the risk of experiencing neuro-symptoms related to PCC. Individuals with these conditions urgently need enhanced personalized care management in current post-pandemic context.
Nano3P-seq: charting the coding and non-coding transcriptome at single molecule resolution
Authors: Begik Oguzhan , Pryszcz Leszek P , Niazi Adnan Muhammad , Valen Eivind , Novoa Eva Maria
Published: November 2024

RNA polyadenylation is crucial for RNA maturation, stability and function, with polyA tail lengths significantly influencing mRNA translation, efficiency and decay. Here, we provide a step-by-step protocol to perform Nanopore 3’ end-capture sequencing (Nano3P-seq), a nanopore-based cDNA sequencing method to simultaneously capture RNA abundances, tail composition and tail length estimates at single-molecule resolution. Taking advantage of a template switching-based protocol, Nano3P-seq can sequence any RNA molecule from its 3’ end, regardless of its polyadenylation status, without the need for PCR amplification or RNA adapter ligation. We provide an updated Nano3P-seq protocol that is compatible with R10.4 flowcells, as well as compatible software for polyA tail length and content prediction, which we termPolyTailor. We demonstrate thatPolyTailorprovides accurate estimates of transcript abundances, tail lengths and content information, while capturing both coding and non-coding RNA biotypes, including mRNAs, snRNAs, and rRNAs. This method can be applied to any RNA sample of interest (e.g. poly(A)-selected, ribodepleted, total RNA), and can be completed in one day. The Nano3P-seq protocol can be performed by researchers with moderate experience in molecular biology techniques and nanopore sequencing library preparation, and basic knowledge of linux bash syntax and R programming. This protocol makes Nano3P-seq accessible and easy to implement by future users aiming to study the tail dynamics and heterogeneity of both coding and non-coding transcriptome in a comprehensive and reproducible manner.

Key Papers

Beğik O, Diensthuber G, Liu H, Delgado-Tejedor A, Kontur C, Niazi AM, Valen E, Giraldez AJ, Beaudoin JD, Mattick JS, Novoa EM. Nano3P-seq: transcriptome-wide analysis of gene expression and tail dynamics using end-capture nanopore cDNA sequencing.Nature Methods20, 75–85 (2023).

https://doi.org/10.1038/s41592-022-01714-w

Delgado-Tejedor A, Medina M, Begik O, Cozzuto L, Lopez J, Blanco B, Ponomarenko J, Novoa EM. Native RNA nanopore sequencing reveals antibiotic-induced loss of rRNA modifications in the A- and P-sites.NatComm15, 10054 (2024).https://doi.org/10.1038/s41467-024-54368-x
Challenges in identifying mRNA transcript starts and ends from long-read sequencing data
Authors: Calvo-Roitberg Ezequiel , Daniels Rachel F. , Pai Athma A.
Published: November 2024

Long-read sequencing (LRS) technologies have the potential to revolutionize scientific discoveries in RNA biology through the comprehensive identification and quantification of full-length mRNA isoforms. Despite great promise, challenges remain in the widespread implementation of LRS technologies for RNA-based applications, including concerns about low coverage, high sequencing error, and robust computational pipelines. Although much focus has been placed on defining mRNA exon composition and structure with LRS data, less careful characterization has been done of the ability to assess the terminal ends of isoforms, specifically, transcription start and end sites. Such characterization is crucial for completely delineating full mRNA molecules and regulatory consequences. However, there are substantial inconsistencies in both start and end coordinates of LRS reads spanning a gene, such that LRS reads often fail to accurately recapitulate annotated or empirically derived terminal ends of mRNA molecules. Here, we describe the specific challenges of identifying and quantifying mRNA terminal ends with LRS technologies and how these issues influence biological interpretations of LRS data. We then review recent experimental and computational advances designed to alleviate these problems, with ideal use cases for each approach. Finally, we outline anticipated developments and necessary improvements for the characterization of terminal ends from LRS data.
Layered superconductors as nonlinear lenses for laser beams tunable by dc magnetic field
Authors: Kvitka N. , Ovcharenko H. V. , Maizelis Z. A. , Apostolov S. S. , Yampol'skii V. A.
Published: November 2024

We develop a theory of focusing of a THz Gaussian laser beam by a layered superconducting slab of finite thickness in the presence of an external dc magnetic field in a nonlinear regime. We show that focusing abilities of the slab, which originate from the specific nonlinearity of the medium, can be flexibly tuned by the external magnetic field providing a way to control THz waves. We analytically study the main characteristics of the Gaussian beam transmitted through such a nonlinear lens, namely, a beam waist and a focusing distance, as functions of radiation frequency, beam intensity, and dc field magnitude. The results of analytic calculations are supported by the numerical simulation of the electromagnetic field distribution in the beam propagating through the superconducting slab.

Published by the American Physical Society
2024
Magnetotransport in a graphite cylinder under quantizing fields
Authors: Kunchur N. , Galeski S. , Menges F. , Wawrzyńczak R. , Felser C. , Meng T. , Gooth J.
Published: November 2024

We analyze the transport properties of curved, three-dimensional graphite samples in strong magnetic fields. Focusing on a millimeter-scale graphite cylinder as a prototypical curved object, we perform longitudinal and Hall voltage measurements while applying quantizing magnetic fields. These measurements are investigated as a function of field strength and angles. Most importantly, we find that angle-dependent Shubnikov-de Hass oscillations are superimposed with angle-independent features. Reproducing the experimental observations, we introduce a network model that accounts for the cylindrical geometry effect by conceptualizing the cylinder as composed of strips of planar graphite in an effectively inhomogeneous magnetic field. Our work highlights how the interplay between geometric curvature and quantizing magnetic fields can be leveraged to engineer tunable spatial current densities within solid-state systems, and paves the way for understanding transport properties of curved and bent three-dimensional samples more generally.

Published by the American Physical Society
2024
Direct quarkonium production in DIS from a joint CGC and NRQCD framework
Authors: Cheung Vincent , Kang Zhong-Bo , Salazar Farid , Vogt Ramona
Published: November 2024

We compute the differential cross section for direct quarkonium production in high-energy electron-nucleus collisions at small x. Our computation is performed within the nonrelativistic QCD factorization formalism that separates the calculation into short distance coefficients and long distance matrix elements that depend on the color and spin of the state. We obtain the short distance coefficients of the production of the heavy quark pair within the framework of the color glass condensate effective field theory, which resums coherent multiple interactions of the heavy quark pair with the nucleus to all orders. Our results are expressed as the convolution of perturbatively calculable functions with multipoint lightlike Wilson line correlators. In the correlation limit, we establish the correspondence between our color glass condensate formulation with calculations employing the transverse momentum dependent (TMD) framework. We extend this correspondence by resumming kinematic power corrections within the improved TMD framework, which interpolates between the TMD formalism and k⊥-factorization formalism. We present a detailed numerical analysis, focusing on J/ψ production in the kinematics accessible at the future Electron-Ion Collider, highlighting the importance of genuine higher-order saturation contributions when the electron collides with a large nucleus. Our results are also valid in the photoproduction limit where we expect the largest contribution from genuine higher-order saturation contributions which could be accessed in ultraperipheral collisions of relativistic heavy ions.

Published by the American Physical Society
2024
Hybrids, tetraquarks, pentaquarks, doubly heavy baryons, and quarkonia in Born-Oppenheimer effective theory
Authors: Berwein Matthias , Brambilla Nora , Mohapatra Abhishek , Vairo Antonio
Published: November 2024

The discovery of XYZ exotic states in the hadronic sector with two heavy quarks represents a significant challenge in particle theory. Understanding and predicting their nature remains an open problem. In this work, we demonstrate how the Born-Oppenheimer (BO) effective field theory (BOEFT), derived from quantum chromodynamics (QCD) on the basis of scale separation and symmetries, can address XYZ exotics of any composition. We derive the Schrödinger coupled equations that describe hybrids, tetraquarks, pentaquarks, doubly heavy baryons, and quarkonia at leading order, incorporating nonadiabatic terms, and present the predicted multiplets. We define the static potentials in terms of the QCD static energies for all relevant cases. We provide the precise form of the nonperturbative low-energy gauge-invariant correlators required for the BOEFT: static energies, generalized Wilson loops, gluelumps, and adjoint mesons. These are to be calculated on the lattice, and we calculate here their short-distance behavior. Furthermore, we outline how spin-dependent corrections and mixing terms can be incorporated using matching computations. Lastly, we discuss how static energies with the same BO quantum numbers mix at large distances leading to the phenomenon of avoided level crossing. This effect is crucial to understand the emergence of exotics with molecular characteristics, such as the χc1(3872). With BOEFT both the tetraquark and the molecular picture appear as part of the same description.

Published by the American Physical Society
2024
Investigation of pion-nucleon contributions to nucleon matrix elements
Authors: Alexandrou Constantia , Koutsou Giannis , Li Yan , Petschlies Marcus , Pittler Ferenc
Published: November 2024

We investigate contributions of excited states to nucleon matrix elements computed in lattice QCD by employing, in addition to the standard nucleon interpolating operator, pion-nucleon (π−N) operators. We solve a generalized eigenvalue problem (GEVP) to obtain an optimal interpolating operator that minimizes overlap with the π−N states. We derive a variant of the standard application of the GEVP method, which allows for constructing 3-point correlation functions using the optimized interpolating operator without requiring the computationally demanding combination that includes π−N operators in both sink and source. We extract nucleon matrix elements using two twisted mass fermion ensembles, one ensemble generated using pion mass of 346 MeV and one ensemble tuned to reproduce the physical value of the pion mass. Especially, we determine the isoscalar and isovector scalar, pseudoscalar, vector, axial, and tensor matrix elements. We include results obtained using a range of kinematic setups, including momentum in the sink. Our results using this variational approach are compared with previous results obtained using the same ensembles and multistate fits without GEVP improvement. We find that for the physical mass point ensemble, the improvement, in terms of suppression of excited states using this method, is most significant for the case of the matrix elements of the isovector axial and pseudoscalar currents.

Published by the American Physical Society
2024
GPU-accelerated semicoherent hierarchical search for stellar-mass binary inspiral signals in LISA
Authors: Bandopadhyay Diganta , Moore Christopher J.
Published: November 2024

Searching for gravitational waves from stellar-mass binary black holes with LISA remains a challenging open problem. Conventional template-bank approaches to the search are impossible due to the prohibitive number of templates that would be required. This paper continues the development of a hierarchical semicoherent stochastic search, extending it to a full end-to-end pipeline that is then applied to multiple mock LISA data streams which include simulated noise. Particle swarm optimization is used as a stochastic search algorithm, tracking multiple maxima of a semicoherent search statistic defined over source parameter space. The pipeline is accelerated by the use of graphical processing units (GPUs). No prior information from observations by ground-based detectors is used; this is necessary in order to provide advance warning of the merger. We find that the pipeline is able to detect sources with signal-to-noise ratios as low as ρ∼17, we demonstrate that these searches can directly seed coarse parameter estimation in cases where the search trigger is loud. An example of how the false-alarm probability can be estimated for this type of GW search is also included.

Published by the American Physical Society
2024
Phase-space methods for neutrino oscillations: Extension to multibeams
Authors: Lacroix Denis , Bauge Angel , Yilmaz Bulent , Mangin-Brinet Mariane , Roggero Alessandro , Balantekin A. Baha
Published: November 2024

The phase-space approach (PSA), which was originally introduced in Lacroix [] to describe neutrino flavor oscillations for interacting neutrinos emitted from stellar objects is extended to describe arbitrary numbers of neutrino beams. The PSA is based on mapping the quantum fluctuations into a statistical treatment by sampling initial conditions followed by independent mean-field evolution. A new method is proposed to perform this sampling that allows treating an arbitrary number of neutrinos in each neutrino beams. We validate the technique successfully and confirm its predictive power on several examples where a reference exact calculation is possible. We show that it can describe many-body effects, such as entanglement and dissipation induced by the interaction between neutrinos. Due to the complexity of the problem, exact solutions can only be calculated for rather limited cases, with a limited number of beams and/or neutrinos in each beam. The PSA approach considerably reduces the numerical cost and provides an efficient technique to accurately simulate arbitrary numbers of beams. Examples of PSA results are given here, including up to 200 beams with time-independent or time-dependent Hamiltonians. We anticipate that this approach will be useful to bridge exact microscopic techniques with more traditional transport theories used in neutrino oscillations. It will also provide important reference calculations for future quantum computer applications where other techniques are not applicable to classical computers.

Published by the American Physical Society
2024
Equivalence of gauge-invariant models for massive integer-spin fields
Authors: Fegebank Arcadia John , Kuzenko Sergei M.
Published: November 2024

There are several approaches to formulate gauge-invariant models for massive integer-spin fields in d dimensions including the following: (i) in terms of symmetric tensor fields ϕμ1…μk, with k=s,s−1,…,0, restricted to be double traceless for k≥4; and (ii) in terms of a quartet of symmetric tensor fields ψμ1…μk, of rank k=s,s−1,s−2,s−3. We demonstrate that these formulations in Minkowski space Md are equivalent to the gauge-invariant theory for a massive integer-spin field proposed in 1989 by Pashnev. We also make use of the Klishevich-Zinoviev theory in

M

d

to derive a unique generalization of the Singh-Hagen model for a massive integer-spin field in d>4 dimensions.

Published by the American Physical Society
2024
Continuous Microwave Photon Counting by Semiconductor-Superconductor Hybrids
Authors: Haldar Subhomoy , Barker David , Havir Harald , Ranni Antti , Lehmann Sebastian , Dick Kimberly A. , Maisi Ville F.
Published: November 2024

We present a continuous microwave photon counter based on superconducting cavity-coupled semiconductor quantum dots. The device utilizes photon-assisted tunneling in a double quantum dot with tunneling events being probed by a third dot. Our device detects both single and multiple-photon absorption events independently, thanks to the energy tunability of a two-level double-dot absorber. We show that the photon-assisted tunnel rates serve as the measure of the cavity photon state in line with the P(E) theory—a theoretical framework delineating the mediation of the cavity photon field via a two-level absorber. We further describe the single photon detection using the Jaynes-Cummings input-output theory and show that it agrees with the P(E) theory predictions at a low-power regime.

Published by the American Physical Society
2024
Incorporating static intersite correlation effects in vanadium dioxide through
DFT+V
Authors: Haas Lea , Mlkvik Peter , Spaldin Nicola A. , Ederer Claude
Published: November 2024

We analyze the effects on the structural and electronic properties of vanadium dioxide (VO2) due to adding an empirical interatomic potential within the density-functional theory+V (DFT+V) framework. We use the DFT+V machinery founded on the extended Hubbard model to apply an empirical self-energy correction between nearest-neighbor vanadium atoms in both rutile and monoclinic phases, and for a set of structures interpolating between these two cases. We observe that imposing an explicit intersite interaction V along the vanadium–vanadium chains enhances the characteristic bonding-antibonding splitting of the relevant bands in the monoclinic phase, thus favoring electronic dimerization and the formation of a bandgap. We then explore the effect of V on the structural properties and the relative energies of the two phases, finding an insulating global energy minimum for the monoclinic phase, consistent with experimental observations. With increasing V, this minimum becomes deeper relative to the rutile structure, and the transition from the metallic to the insulating state becomes sharper. We also analyze the effect of applying the +V correction either to all or only to selected vanadium–vanadium pairs and both in the monoclinic as well as the metallic rutile phase. Our results suggest that DFT+V can indeed serve as a computationally inexpensive unbiased way of modeling VO2 which is well suited for studies that, e.g., require large system sizes.

Published by the American Physical Society
2024
Semimetallization induced Hall anomaly in doped polymers
Authors: Guo Zean , Wang Jiawei , Li Mengmeng , Lv Yawei , Lu Nianduan , Bi Chong , Wang Yeliang , Li Ling , Liu Ming
Published: November 2024

Hall anomaly related to deviations in Hall carrier concentrations have always been recognized as signs of charge incoherence in organic semiconductors, which lack ordered lattices. In this paper, we show that the Hall carrier concentration anomaly in doped polymers might be a result of semimetallization. Based on the observation of semimetal-like states, a dual-channel model, in which electrons and holes compensate the Hall voltages of each other, is employed to account for the anomaly. Observations of possible nonlinear Hall effect and temperature dependent Hall signs further support the origin of Hall anomaly from semimetal states.

Published by the American Physical Society
2024
High-Coherence Kerr-Cat Qubit in 2D Architecture
Authors: Hajr Ahmed , Qing Bingcheng , Wang Ke , Koolstra Gerwin , Pedramrazi Zahra , Kang Ziqi , Chen Larry , Nguyen Long B. , Jünger Christian , Goss Noah , Huang Irwin , Bhandari Bibek , Frattini Nicholas E. , Puri Shruti , Dressel Justin , Jordan Andrew N. , Santiago David I. , Siddiqi Irfan
Published: November 2024

The Kerr-cat qubit is a bosonic qubit in which multiphoton Schrödinger cat states are stabilized by applying a two-photon drive to an oscillator with a Kerr nonlinearity. The suppressed bit-flip rate with increasing cat size makes this qubit a promising candidate to implement quantum error correction codes tailored for noise-biased qubits. However, achieving strong light-matter interactions necessary for stabilizing and controlling this qubit has traditionally required strong microwave drives that heat the qubit and degrade its performance. In contrast, increasing the coupling to the drive port removes the need for strong drives at the expense of large Purcell decay. By integrating an effective band-block filter on chip, we overcome this trade-off and realize a Kerr-cat qubit in a scalable 2D superconducting circuit with high coherence. This filter provides 30 dB of isolation at the qubit frequency with negligible attenuation at the frequencies required for stabilization and readout. We experimentally demonstrate quantum nondemolition readout fidelity of 99.6% for a cat with eight photons. Also, to have high-fidelity universal control over this qubit, we combine fast Rabi oscillations with a new demonstration of the X(π/2) gate through phase modulation of the stabilization drive. Finally, the lifetime in this architecture is examined as a function of the cat size of up to ten photons in the oscillator, achieving a bit-flip time higher than 1 ms and only a linear increase in the phase-flip rate, in good agreement with the theoretical analysis of the circuit. Our qubit shows promise as a building block for fault-tolerant quantum processors with a small footprint.

Published by the American Physical Society
2024
Reducing heat load density with asymmetric and inclined double-crystal monochromators: principles and requirements revisited
Authors: Huang XianRong , Assoufid Lahsen , Macrander Albert T.
Published: November 2024

Asymmetric double-crystal monochromators (aDCMs) and inclined DCMs (iDCMs) can significantly expand the X-ray beam footprint and consequently reduce the heat load density and gradient. Based on rigorous dynamical theory calculations, the major principles and properties of aDCMs and iDCMs are presented to guide their design and development, particularly for fourth-generation synchrotrons. In addition to the large beam footprint, aDCMs have very large bandwidths (up to ∼10 eV) and angular acceptance, but the narrow angular acceptance of the second crystal requires precise control of the relative orientations and strains. Based on Fourier coupled-wave diffraction theory calculations, it is rigorously proved that the iDCM has almost the same properties as the conventional symmetric DCM, including the efficiency, angular acceptance, bandwidth, tuning energy range and sensitivity to misalignment. The exception is that, for the extremely inclined geometry that can achieve very large footprint expansion, the iDCM has (beneficially) a larger bandwidth and wider angular acceptance. Inclined diffraction has the `rho-kick effect' that can be cancelled by the second reflection of the iDCM (even with misalignment), except that inhomogeneous strains may cause non-uniform rho-kick angles. At present, fabrication/mounting-induced strains pose low risk since they can be controlled to <0.5 µrad over large areas. The only uncertain challenge is the thermally induced strains, yet it is estimated that these strains are naturally lowered by the large footprint and may be further mitigated by optimized cryogenic cooling to the 1–2 µrad level. Overall, aDCMs and iDCMs have more stringent requirements than normal DCMs, but they are feasible schemes in practice.
Hard X-ray single-shot spectrometer of PAL-XFEL
Authors: Kim Sangsoo , Lee Jae Hyuk , Nam Daewoong , Park Gisu , Kim Myong-jin , Eom Intae , Nam Inhyuk , Shim Chi Hyun , Kim Jangwoo
Published: November 2024

A transmissive single-shot spectrometer has been developed to monitor shot-to-shot spectral structures in the hard X-ray beamline of the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL). The established spectrometer comprises 10 µm-thick Si crystals bent to a radius of curvature of 100 mm. Depending on the photon energy range, either the Si (111) or Si (110) crystal can be selected for spectral analysis. Especially in the energy range 4.5–17 keV, the spectrometer is designed to cover a spectral range wider than the full free-electron laser bandwidth and to guarantee a high resolution sufficient for resolving each spectral spike. This paper presents the design specifications, instruments and performance of this spectrometer, which has also been applied to demonstrate the spectral properties of various XFEL sources, such as self-amplified spontaneous emission, monochromatic and seeded beams.
Development of MHz X-ray phase contrast imaging at the European XFEL
Authors: Koliyadu Jayanath C. P. , Moško Daniel , Asimakopoulou Eleni Myrto , Bellucci Valerio , Birnšteinová Šarlota , Bean Richard , Letrun Romain , Kim Chan , Kirkwood Henry , Giovanetti Gabriele , Jardon Nerea , Szuba Janusz , Guest Trey , Koch Andreas , Grünert Jan , Szeles Peter , Villanueva-Perez Pablo , Reuter Fabian , Ohl Claus-Dieter , Noack Mike Andreas , Garcia-Moreno Francisco , Kuglerová-Valdová Zuzana , Juha Libor , Nikl Martin , Yashiro Wataru , Soyama Hitoshi , Eakins Daniel , Korsunsky Alexander M. , Uličný Jozef , Meents Alke , Chapman Henry N. , Mancuso Adrian P. , Sato Tokushi , Vagovič Patrik
Published: November 2024

We report on recent developments that enable megahertz hard X-ray phase contrast imaging (MHz XPCI) experiments at the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX) instrument of the European XFEL facility (EuXFEL). We describe the technical implementation of the key components, including an MHz fast camera and a modular indirect X-ray microscope system based on fast scintillators coupled through a high-resolution optical microscope, which enable full-field X-ray microscopy with phase contrast of fast and irreversible phenomena. The image quality for MHz XPCI data showed significant improvement compared with a pilot demonstration of the technique using parallel beam illumination, which also allows access to up to 24 keV photon energies at the SPB/SFX instrument of the EuXFEL. With these developments, MHz XPCI was implemented as a new method offered for a broad user community (academic and industrial) and is accessible via standard user proposals. Furthermore, intra-train pulse diagnostics with a high few-micrometre spatial resolution and recording up to 128 images of consecutive pulses in a train at up to 1.1 MHz repetition rate is available upstream of the instrument. Together with the diagnostic camera upstream of the instrument and the MHz XPCI setup at the SPB/SFX instrument, simultaneous two-plane measurements for future beam studies and feedback for machine parameter tuning are now possible.
A polymeric form of basic iron(III) acetate with an acetic acid ligand
Authors: Abrahams Brendan F. , Robson Richard , Commons Christopher J.
Published: November 2024

A new crystalline compound, catena-poly[hexa-μ-acetato-(acetic acid)-μ3-oxido-triangulo-triiron(III)]-μ-acetato], [Fe3(C2H3O2)7O(C2H4O2)]
n
, incorporating the basic ferric acetate unit, has been obtained from an acetic anhydride solution of hydrated iron(III) nitrate. The crystals have the composition Fe3O(OAc)7(HOAc) (HOAc is acetic acid) and include the well-known [Fe3O(OAc)6]+ unit, in which the FeIII centres are linked to a central coplanar μ3-oxido ligand. Acetate ions provide bridges between pairs of FeIII centres. These individual [Fe3O(OAc)6]+ units are linked by additional bridging acetate anions to form zigzag chains. The bridging acetate ions coordinate to a position trans to the oxido group on two of the FeIII centres. Remarkably, the trans site on the third FeIII centre is occupied by the carbonyl group of an acetic acid molecule. This is the first reported case of an acetic acid molecule coordinating to an FeIII centre. Not surprisingly, the acetic acid molecule is only weakly coordinating, resulting in a short Fe—O(oxido) bond trans to the carbonyl group. The trans influence apparent in this structure provides an interesting contrast with the structurally similar MnIII analogue, in which the corresponding pair of trans bonds are both elongated because of the Jahn–Teller effect.
Protonated oxalyl chloride and the ClCO+ cation
Authors: Steiner Sebastian , Djordjevic Kristina , Bockmair Valentin , Hollenwäger Dirk , Kornath Andreas J.
Published: November 2024

The reactions of oxalyl chloride were investigated in the binary superacidic systems HF/SbF5 and DF/SbF5. O-Monoprotonated oxalyl chloride was isolated and represents the first example of a protonated acyl chloride. Diprotonated oxalyl chloride is only stable in solution. Salts of the ClCO+ cation were synthesized from the reactions of oxalyl chloride or COClF with SbF5 in 1,1,1,2-tetrafluoroethane (R-134a, CF3CFH2). The colourless salts were characterized by low-temperature vibrational spectroscopy, NMR spectroscopy and single-crystal X-ray diffraction. (1,2-Dichloro-2-oxoethylidene)oxidanium hexafluoridoantimonate(V), [C2O(OH)Cl2][SbF6], crystallizes in the monoclinic space group P21 and carbonyl chloride hexadecafluoridotriarsenate(V) [ClCO][Sb3F16], in the trigonal space group P31, with two and three formula units per unit cell, respectively. Monoprotonated oxalyl chloride and the ClCO+ cation both display very short C—Cl bonds with a strong double-bond character.
Growth functions of periodic space tessellations
Authors: Naskręcki Bartosz , Malinowski Jakub , Dauter Zbigniew , Jaskolski Mariusz
Published: November 2024

This work analyzes the rules governing the growth of the numbers of vertices, edges and faces in all possible periodic tessellations of the 2D Euclidean space, and encodes those rules in several types of polynomial growth functions. These encodings map the geometric, combinatorial and topological properties of the tessellations into sets of integer coefficients. Several general statements about these encodings are given with rigorous mathematical proof. The variation of the growth functions is represented graphically and analyzed in orphic diagrams, so named because of their similarity to orphic art. Several examples of 3D space groups are included, to emphasize the complexity of the growth functions in higher dimensions. A freely available Python library is presented to facilitate the discovery of the growth functions and the generation of orphic diagrams.
Haar wavelet analysis of axisymmetric vibration of 2-D functionally graded porous thin annular plate resting on the Winkler foundation
Authors: Kumar Yajuvindra , Pandit Sapna
Published: November 2024

Purpose

In this paper, free axisymmetric vibration analysis of a two-directional functionally graded porous thin annular plate resting on the Winkler foundation is presented utilizing the classical plate theory (CPT). The mechanical properties are considered to be varying in the radial-thickness plane.

Design/methodology/approach

Based on the CPT, the governing differential equation of motion is derived. The highest-order derivative of displacement is approximated by Haar wavelets and successive lower-order derivatives are obtained by integration. The integration coefficients are calculated using boundary conditions. The fundamental frequency for clamped-clamped, clamped-simply supported, simply supported-clamped and simply supported-simply supported boundary conditions is obtained.

Findings

The effects of the porosity coefficient, the coefficient of radial variation, the exponent of power law, the foundation parameter, the aspect ratio and boundary conditions are investigated on fundamental frequency. A convergence study is conducted to validate the present analysis. The accuracy and reliability of the Haar wavelets are shown by comparing frequencies with those available in the literature. Three-dimensional mode shapes in the fundamental mode for all four boundary conditions are presented.

Originality/value

Based on the Haar wavelet method, a free axisymmetric vibration model of a porous thin annular plate is solved in which 2-D variation of mechanical properties is considered.
Job crafting agility: a conceptual proposition for rethinking behaviour in organizations
Authors: Dhanpat Nelesh
Published: November 2024

Purpose

This research proposes a new construct towards the job crafting theory, termed job crafting agility. The study provides the potential contributions of job crafting agility in the context of rethinking behaviours in organizations during times of disruption and change.

Design/methodology/approach

A conceptual analysis is followed to present the construct of job crafting agility, based on a review of job crafting and agility literature.

Findings

The research proposes job-crafting agility as a dynamic and proactive process of balancing job demands and resources in response to changing or fluctuating circumstances. The study provides four propositions on job-crafting agility. This research contributes to the existing literature by proposing a new construct, job-crafting agility that can help organizations and employees adapt to changing circumstances during disruption and change. It highlights the unique components of job-crafting agility and its theoretical foundations and distinguishes the new construct from other forms of job crafting.

Research limitations/implications

The construct of job crafting agility is new and requires further empirical validation. It presents several propositions as recommendations for future studies.

Practical implications

The paper provides practical implications for organizations and managers on promoting job crafting agility among employees. It emphasizes the importance of creating a work environment that encourages flexibility, experimentation and learning to enable employees to adjust to changing circumstances effectively.

Originality/value

This research makes a novel contribution by introducing and defining job crafting agility, and advances job crafting theory by exploring how job crafting agility can foster resilience and positive organizational outcomes amid continual change and disruption.
Crowdfunding, asymmetric information and pecking order
Authors: Miglo Anton
Published: November 2024

Purpose

Crowdfunding is a rapidly growing phenomenon in theory and practice. A significant gap exists between theoretical literature and empirical evidence regarding the volumes of crowdfunding and the quality of firms that use crowdfunding.

Design/methodology/approach

This is one of the first articles that offers a theory of entrepreneurs' choice between debt, equity and crowdfunding (reward-based). It uses a game-theoretic model where information about the expected quality of products developed by entrepreneurs is asymmetric.

Findings

We argue that in most cases crowdfunding is at the end of pecking order. The payments in the form of pre-orders come before the project investment is made making the entrepreneur's profit independent of actual quality of the product creating a strong ground for cross-subsidies of low-quality entrepreneurs by high-quality entrepreneurs in a pooling equilibrium.

Originality/value

The paper is consistent with some well-known empirical phenomena on crowdfunding, e.g. relatively small volumes of crowdfunding vs traditional funding, low volumes of reward-based crowdfunding vs debt-based and equity-based crowdfunding and excess entry of low-quality firms to crowdfunding market. We further compare this approach with an approach based on asymmetric information about the cost of production/investment (as in Belleflamme et al. (2014) and some other papers) and argue that even though some predictions maybe close under some general assumptions both approaches lead to qualitatively different results.
Does environmental policy stringency promote financial development? New policy insights from BRICS countries
Authors: Akram Vaseem , Srivastav Anant
Published: November 2024

Purpose

Over the past few decades, BRICS nations have implemented several environmental legislations to combat environmental issues, along with the development of the financial sector. However, they still face the dual challenge of balancing financial development (FD) and reducing carbon emissions to achieve sustainable development. Hence, this study aims to explore how environmental policy stringency (EPS) influences FD in BRICS nations from 1993 to 2020.

Design/methodology/approach

The authors performed a panel data analysis to examine the effect of the EPS on FD. Firstly, they conducted a panel unit root test using the Levin–Lin–Chu and the Im–Pesaran–Shin unit root tests to check the stationarity of the data. Then, they used the fixed effect model for analysis. A feasible generalised least squares test is used to ensure the robustness of the results.

Findings

The EPS positively affects FD through financial markets and intuitions in BRICS nations, indicating that more stringent environmental policies of BRICS countries promote FD in these nations.

Practical implications

This study suggests that policymakers in BRICS nations should consider strengthening EPS, implying the dual benefit of aligning environmental sustainability goals with economic growth.

Originality/value

This study provides a deeper understanding by disassembling FD into financial markets and institutions, thereby establishing a nuanced relationship with EPS, which is highly relevant for addressing the distinctive financial systems and environmental challenges of BRICS nations. Therefore, this study fills this gap and offers new insights into the relationship between EPS and FD in these nations.