bluuebunny/crossref_metadata_2025 huggingface dataset:
CharacterisingStaphylococcus aureusgenomic epidemiology with Multilevel Genome Typing
Authors: Cheney Liam , Payne Michael , Kaur Sandeep , McKew Genevieve , Lan Ruiting
Published: May 2024

Staphylococcus aureusis a major source of both hospital and community acquired infections, and is the leading source of skin and soft tissue infections worldwide. Advances in whole genome sequencing (WGS) technologies have recently generated large volumes ofS. aureusWGS data. The timely classification ofS. aureusWGS data with genomic typing technologies has the potential to describe detailed genomic epidemiology at large and small scales. In this study, a multilevel genome typing (MGT) scheme comprised of 8 levels of multilocus sequence typing schemes of increasing resolution was developed forS. aureusand used to analyse 50,481 publicly available genomes. Application of MGT toS. aureusepidemiology was showcased in three case studies. Firstly, the population structure of the globally disseminated sequence type ST8 were described by MGT2, which was compared withSpatyping. Secondly, MGT was used to characterise MLST ST8 - PFGE USA300 isolates that colonised multiple body sites of the same patient. Unique STs from multiple MGT levels were able to group isolates of the same patient, and the highest resolution MGT8 separated isolates within a patient that varied in predicted antimicrobial resistance. Lastly, MGT was used to describe the transmission of MLST ST239 - SCCmecIII throughout a single hospital. MGT STs were able to describe both isolates that had spread between wards and also isolates that had colonised different reservoirs within a ward. TheS. aureusMGT describes large- and small-scaleS. aureusgenomic epidemiology with scalable resolutions using stable and standardised ST assignments. TheS. aureusMGT database is online (https://mgtdb.unsw.edu.au/staphylococcus) and is capable of tracking new and existing clones to facilitate the design of new strategies to reduce the global burden ofS. aureusrelated diseases.
Introgression impacts the evolution of bacteria, but species borders are rarely fuzzy
Authors: Diop Awa , Bobay Louis-Marie
Published: May 2024

Most bacteria engage in gene flow and that this may act as a force maintaining species cohesiveness like it does in sexual organisms. However, introgression (gene flow between the genomic backbone of distinct species) has been reported in bacteria and is associated with fuzzy species borders in some lineages, but its prevalence and impact on the delimitation of bacterial species has not been systematically characterized. Here, we quantified the patterns of introgression across 50 major bacterial lineages. Our results reveal that bacteria present various levels of introgression, with an average of 2% of introgressed core genes and up to 12% inCampylobacter. Furthermore, our results show that some species are more prone to introgression than others within the same genus and introgression is most frequent between highly related species. We found evidence that the various levels of introgression across lineages are likely related to ecological proximity between species. Introgression can occasionally lead to fuzzy species borders, although many of these cases are likely instances of ongoing speciation. Overall, our results indicate that introgression has substantially shaped the evolution and the diversification of bacteria, but this process does not substantially blur species borders.
Intestinal microbiome dysbiosis increasesMycobacteriapulmonary colonization in mice by regulating theNos2-associated pathways
Authors: Han MeiQing , Wang Xia , Su Lin , Pan Shiqi , Liu Ningning , Li Duan , Liu Liang , Cui JunWei , Zhao Huajie , Yang Fan
Published: May 2024

Abstract

Increasing researches reveal gut microbiota was associated with the development of tuberculosis. How to prevent or reduceMycobacterium tuberculosiscolonization in the lungs is a key measure to prevent tuberculosis. However, the data on gut microbiota preventingMycobacteriumcolonization in the lungs were scarce. Here, we established the clindamycin-inducing intestinal microbiome dysbiosis and fecal microbial transplantation models in mice to identify gut microbiota’s effect onMycobacterium’s colonization in the mouse lungs and explore its potential mechanisms. The results showed that clindamycin treatment altered the diversity and composition of the intestinal bacterial and fungal microbiome, weakened the trans-kingdom network interactions between bacteria and fungi, and induced gut microbiome dysbiosis in the mice. Gut microbiota dysbiosis increases intestinal permeability and enhances the susceptibility ofMycobacteriumcolonization in the lungs of mice. The potential mechanisms were gut microbiota dysbiosis altered the lung transcriptome and increasedNos2expression through the “gut-lung axis”.Nos2high expression disrupts the intracellular antimicrobial and anti-inflammatory environment by increasing the concentration of NO, decreasing the levels of ROS andDefb1in the cells, and resulting in promotingMycobacteriacolonization in the lungs of mice. The present study raises a potential strategy for reducing the risks ofMycobacteriainfections and transmission by regulating the gut microbiome balance.
Ability to monitor deviations of own movement without visual feedback
Authors: Brandt I.M. , Bjerregaard S.M. , Jensen D.B. , Giessing M.G. , Grünbaum T.G. , Christensen M.S.
Published: May 2024

How conscious sensations of movement relates to signals essential for movement control remains under investigation. This question is typically investigated using visuomotor tasks, in which sensation of movement is disturbed by conflicting visual feedback. The present study uses metacognitive judgements to investigate conscious access to movement signals, unchallenged by visual signals, in an index finger force task. We found that some participants can correctly assign metacognitive judgements (MCJs) to their own force, suggesting that participants do indeed have metacognitive access to sensorimotor signals. We found no correlation between metacognitive access to sensorimotor signal and variance in motor performance. Further, we found that in this purely sensorimotor task, internal focus of attention reduces variability in force compared to external focus of attention. Our results indicate that not only is it possible to access sensorimotor information, it is also possible to use focus of attention to reduce variability in force performance.
Fitness incentives to male fighters undermine fighting performance in intergroup contests
Authors: Green P.A. , Sankey D.W.E. , Collins T. , Mwanguhya F. , Nichols H. J. , Cant M.A. , Thompson F.J.
Published: May 2024

In humans and other animal societies, groups engage in intergroup conflicts over resources. The success of groups in these conflicts depends on individual contributions to collective fighting, yet individuals may have personal fitness incentives to defect rather than fight, which could undermine group performance. Here we test the hypothesis that personal fitness incentives affect intergroup conflict success in wild banded mongooses (Mungos mungo). In this species, intergroup fights are sometimes initiated by estrous females, who gain outgroup matings while their male group-mates contribute most of the fighting effort. We found that group fighting success was highest when a group’s females were in estrus, suggesting that, although females may initiate fights, their male group-mates seem motivated to chase away rival groups to defend their paternity. Surprisingly, we found that groups that won fights conceded more paternity to their rivals than groups that lost. In other words, behavioral “wins” did not always result in fitness “wins”. Younger males were more successful at attaining paternity between groups compared to within their own groups, suggesting that they may forego intergroup fighting to focus on intergroup mating. Overall, our results suggest that personal fitness incentives—here, in the form of paternity—vary widely among group members and can undermine rather than promote collective fighting performance. Such conflicts of interest are likely inherent in group combat and can contribute to variation in the frequency and costliness of intergroup violence.
Cntnap2loss drives striatal neuron hyperexcitability and behavioral inflexibility
Authors: Cording Katherine R. , Tu Emilie M. , Wang Hongli , Agopyan-Miu Alexander H. C. W. , Bateup Helen S.
Published: May 2024

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by two major diagnostic criteria - persistent deficits in social communication and interaction, and the presence of restricted, repetitive patterns of behavior (RRBs). Evidence from both human and animal model studies of ASD suggest that alteration of striatal circuits, which mediate motor learning, action selection, and habit formation, may contribute to the manifestation of RRBs.CNTNAP2is a syndromic ASD risk gene, and loss of function ofCntnap2in mice is associated with RRBs. How loss ofCntnap2impacts striatal neuron function is largely unknown. In this study, we utilizedCntnap2-/-mice to test whether altered striatal neuron activity contributes to aberrant motor behaviors relevant to ASD. We find thatCntnap2-/-mice exhibit increased cortical drive of striatal projection neurons (SPNs), with the most pronounced effects in direct pathway SPNs. This enhanced drive is likely due to increased intrinsic excitability of SPNs, which make them more responsive to cortical inputs. We also find thatCntnap2-/-mice exhibit spontaneous repetitive behaviors, increased motor routine learning, and cognitive inflexibility. Increased corticostriatal drive, in particular of the direct pathway, may contribute to the acquisition of repetitive, inflexible behaviors inCntnap2mice.
Noradrenergic modulation of stress induced catecholamine release: Opposing influence of FG7142 and yohimbine
Authors: Visocky Vladimir , Turner Carleigh J. , Lowrie Matthew H , Alibro Anthony , Messanvi Fany , Chudasama Yogita
Published: May 2024

Background: Life stress modulates decision making, particularly in the face of risk, in some cases prompting vulnerable populations to make suboptimal, life-altering choices. In the brain, stress is known to alter the extracellular release of catecholamines in structures such as basolateral amygdala (BLA) and nucleus accumbens (NAc), but the relationship between catecholamines and decision-making behavior under stress has not been systemically explored.

Methods:We developed an operant touchscreen decision-making task for rats comprising elements of loss aversion and risk seeking behavior. Rats were first injected systemically with an adrenergic α2A-receptor agonist (guanfacine) and antagonist (yohimbine), as well as a partial inverse GABAA agonist, FG 7142, known to induce anxiety and stress related physiological responses in a variety of species, including humans. We then used fiber photometry to monitor NE in the basolateral amygdala (BLA), and DA activity in the nucleus accumbens (NAc) while animals engaged in decision-making and following systemic injections of FG 7142 and yohimbine.

Results:Neither yohimbine nor guanfacine had any impact on decision making strategy but altered motivational state with yohimbine making the animal almost insensitive to the reward outcome. The pharmacological induction of stress with FG 7142 biased the rats’ decisions towards safety, but this bias shifted toward risk when co-treated with yohimbine. In the BLA and NAc, the FG 7142 altered catecholamine release, with systemic yohimbine producing opposing effects on NE and DA release.

Conclusions: Stress induced changes in catecholamine release in the BLA and NAc can directly influence loss sensitivity, decisions and motivation, which can be modulated by the α2A adrenoreceptor antagonist, yohimbine.
Structure of the Flotillin Complex in a Native Membrane Environment
Authors: Fu Ziao , MacKinnon Roderick
Published: May 2024

In this study we used cryo-electron microscopy to determine the structures of the Flotillin protein complex, part of the Stomatin, Prohibitin, Flotillin, and HflK/C (SPFH) superfamily, from cell-derived vesicles without detergents. It forms a right-handed helical barrel consisting of 22 pairs of Flotillin1 and Flotillin2 subunits, with a diameter of 32 nm its wider end and 19 nm at its narrower end. Oligomerization is stabilized by the C-terminus, which forms two helical layers linked by a β-strand, and coiled-coil domains that enable strong charge-charge inter-subunit interactions. Flotillin interacts with membranes at both ends; through its SPFH1 domains at the wide end and the C-terminus at the narrow end, facilitated by hydrophobic interactions and lipidation. The inward tilting of the SPFH domain, likely triggered by phosphorylation, suggests its role in membrane curvature induction, which could be connected to its proposed role in clathrin-independent endocytosis. The structure suggests a shared architecture across the family of SPFH proteins and will promote further research into Flotillin’s roles in cell biology.

Significance statement

It is well known that many biochemical processes in cells must occur in localized regions. There are many different ideas about how cells keep processes localized. In this study we demonstrate that Flotillin1 and Flotillin2 co-assemble to form a large, truncated cone shaped cage whose wide end is always attached to a membrane surface and whose narrow end is sometimes attached to a separate membrane. The entire wall of the cage is without holes and is likely impervious even to small molecules, forming a diffusion barrier that can connect membrane systems. The Flotillin cage is thus well suited to isolate biochemical processes. Through membrane attachment, it also alters local membrane curvature, which could influence endocytic and mechanosensory processes.
Conceptual design of a high reactive-power ferroelectric fast reactive tuner
Authors: Ben-Zvi Ilan , Burt Graeme , Castilla Alejandro , Macpherson Alick , Shipman Nicholas
Published: May 2024

We present a novel design of a ferroelectric fast reactive tuner (FE-FRT) capable of modulating mega-VAR reactive power on a submicrosecond timescale. The high reactive power capability of our design extends the range of applications of reactive tuners to numerous applications. We present a detailed analytical model of the performance of a megawatt-class reactive power device and benchmark it against finite-element method eigenmode and frequency domain electromagnetic simulations. We introduce new features, including an annulus design for the ferroelectric capacitors and capacitive window coupling to the cavity. We consider thermal design issues and nonlinear effects in the ferroelectric. The model covers several configurations, allowing control of the frequency of superconducting and normal-conducting cavities in a variety of applications and frequencies. We calculate that the FE-FRT designed should be capable of handling around 0.45 MVAR of reactive power with around 3 kW of resistive losses, providing a frequency tuning range of 8 kHz in an example of 400 MHz cavity geometry.

Published by the American Physical Society
2024
Pseudofermion functional renormalization group study of dipolar-octupolar pyrochlore magnets
Authors: Chern Li Ern , Desrochers Félix , Kim Yong Baek , Castelnovo Claudio
Published: May 2024

Motivated by recent experiments on Ce2Zr2O7 that reveal a dynamic, liquidlike ground state, we study the nearest-neighbor XYZ Hamiltonian of dipolar-octupolar pyrochlore magnets with the pseudofermion functional renormalization group (PFFRG), which is numerically implemented by the software. Taking the interaction between the octupolar components to be dominant and antiferromagnetic, we map out the phase diagram demarcating the quantum disordered and magnetically ordered states. We identify four distinct phases, namely, the 0-flux and π-flux quantum spin ices and the all-in-all-out magnetic orders along the local z and x axes. We further use the static two-spin correlation output by the PFFRG algorithm to compute the polarized neutron scattering cross sections, which are able to capture several qualitative features observed experimentally, in the materially relevant parameter regime that stabilizes the π-flux quantum spin ice. Our results provide support for a quantum spin-liquid ground state in Ce2Zr2O7.

Published by the American Physical Society
2024
Self-forced inspirals with spin-orbit precession
Authors: Lynch Philip , van de Meent Maarten , Warburton Niels
Published: May 2024

We develop the first model for extreme mass-ratio inspirals with misaligned angular momentum and primary spin, and zero eccentricity—also known as quasispherical inspirals—evolving under the influence of the first-order in mass-ratio gravitational self-force. The forcing terms are provided by an efficient spectral interpolation of the first-order gravitational self-force in the outgoing radiation gauge. In order to speed up the calculation of the inspiral, we apply a near-identity (averaging) transformation to eliminate all dependence of the orbital phases from the equations of motion while maintaining all secular effects of the first-order gravitational self-force at postadiabatic order. The resulting solutions are defined with respect to “Mino time”; thus, we perform a second averaging transformation, so the inspiral is parametrized in terms of Boyer-Lindquist time, which is more convent for LISA data analysis. We also perform a similar analysis using the two-timescale expansion and find that using either approach yields self-forced inspirals that can be evolved to subradian accuracy in less than a second. The dominant contribution to the inspiral phase comes from the adiabatic contributions, so we further refine our self-force model using information from gravitational wave flux calculations. The significant dephasing we observe between the lower and higher accuracy models highlights the importance of accurately capturing adiabatic contributions to the phase evolution.

Published by the American Physical Society
2024
Global fit of electron and neutrino elastic scattering data to determine the strange quark contribution to the vector and axial form factors of the nucleon
Authors: Pate S. F. , Papavassiliou V. , Schaub J. P. , Trujillo D. P. , Ivanov M. V. , Barbaro M. B. , Giusti C.
Published: May 2024

We present a global fit of neutral-current elastic (NCE) neutrino-scattering data and parity-violating electron-scattering (PVES) data with the goal of determining the strange quark contribution to the vector and axial form factors of the proton. Previous fits of this form included data from a variety of PVES experiments (PVA4, HAPPEx, G0, SAMPLE) and the NCE neutrino and anti-neutrino data from BNL E734. These fits did not constrain the strangeness contribution to the axial form factor GAs(Q2) at low Q2 very well because there was no NCE data for Q2<0.45  GeV2. Our new fit includes for the first time MiniBooNE NCE data from both neutrino and antineutrino scattering; this experiment used a hydrocarbon target and so a model of the neutrino interaction with the carbon nucleus was required. Three different nuclear models have been employed: a relativistic Fermi gas model, the superscaling approximation model, and a spectral function model. We find a tremendous improvement in the constraint of GAs(Q2) at low Q2 compared to previous work, although more data is needed from NCE measurements that focus on exclusive single-proton final states, for example from MicroBooNE.

Published by the American Physical Society
2024
Wigner distributions of sea quarks in the light-cone quark model
Authors: Luan Xiaoyan , Lu Zhun
Published: May 2024

We investigate the Wigner distributions of u¯ and d¯ quarks in a proton using the overlap representation within the light cone formalism. Using the light-cone wave functions which are obtained from the baryon-meson fluctuation model in terms of the |qq¯B⟩ Fock states, we calculate the Wigner distributions for the unpolarized/longitudinally polarized sea quarks in an unpolarized/longitudinally polarized proton. The Wigner distributions can be obtained through a Fourier transform on the generalized transverse-momentum dependent parton distributions (GTMDs). We also calculate the GTMDs of u¯ and d¯ quarks in the intermediate step. Numerical results for the Wigner distributions of u¯ and d¯ quarks in transverse momentum space, impact parameter space and the mixed plane are presented. We also study the orbital angular momentum and the spin-orbit correlations of the sea quarks.

Published by the American Physical Society
2024
Dark dimension, the swampland, and the dark matter fraction composed of primordial near-extremal black holes
Authors: Anchordoqui Luis A. , Antoniadis Ignatios , Lüst Dieter
Published: May 2024

In a recent publication we studied the decay rate of primordial black holes perceiving the dark dimension, an innovative five-dimensional (5D) scenario that has a compact space with characteristic length scale in the micron range. We demonstrated that the rate of Hawking radiation of 5D black holes slows down compared to 4D black holes of the same mass. Armed with our findings we showed that for a species scale of O(1010  GeV), an all-dark-matter interpretation in terms of primordial black holes should be feasible for black hole masses in the range 1014≲M/g≲1021. As a natural outgrowth of our recent study, herein we calculate the Hawking evaporation of near-extremal 5D black holes. Using generic entropy arguments we demonstrate that Hawking evaporation of higher-dimensional near-extremal black holes proceeds at a slower rate than the corresponding Schwarzschild black holes of the same mass. Assisted by this result we show that if there were 5D primordial near-extremal black holes in nature, then a primordial black hole all-dark-matter interpretation would be possible in the mass range 105β≲M/g≲1021, where β is a parameter that controls the difference between mass and charge of the associated near-extremal black hole.

Published by the American Physical Society
2024
Effective potential between static sources in quenched light-front Yukawa theory
Authors: Bray A. P. , Chabysheva S. S. , Hiller J. R.
Published: May 2024

We compute a nonperturbative effective potential between two static fermions in light-front Yukawa theory as a Hamiltonian eigenvalue problem. Fermion pair production is suppressed, to make possible an exact analytic solution in the form of a coherent state of bosons that form clouds around the sources. The effective potential is essentially an interference term between individual clouds. The model is regulated with Pauli-Villars bosons and fermions, to achieve consistent quantization and renormalization of masses and couplings. This extends earlier work on scalar Yukawa theory where Pauli-Villars regularization did not play a central role. The key result is that the nonperturbative solution restores rotational symmetry even though the light-front formulation of Yukawa theory, with its preferred axis, appears antithetical to such a symmetry.

Published by the American Physical Society
2024
General bubble expansion at strong coupling
Authors: Wang Jun-Chen , Yuwen Zi-Yan , Hao Yu-Shi , Wang Shao-Jiang
Published: May 2024

The strongly coupled system like the quark-hadron transition (if it is of first order) is becoming an active play yard for the physics of cosmological first-order phase transitions. However, the traditional field theoretic approach to strongly coupled first-order phase transitions is of great challenge, driving recent efforts from holographic dual theories with explicit numerical simulations. These holographic numerical simulations have revealed an intriguing linear correlation between the phase pressure difference (pressure difference away from the wall) to the nonrelativistic terminal velocity of an expanding planar wall, which has been reproduced analytically alongside both cylindrical and spherical walls from perfect-fluid hydrodynamics in our previous study but only for a bag equation of state. We also found, in our previous study, a universal quadratic correlation between the wall pressure difference (pressure difference near the bubble wall) to the nonrelativistic terminal wall velocity regardless of wall geometries. In this paper, we will generalize these analytic relations between the phase/wall pressure difference and terminal wall velocity into a more realistic equation of state beyond the simple bag model, providing the most general predictions so far for future tests from holographic numerical simulations of strongly coupled first-order phase transitions.

Published by the American Physical Society
2024
Quantum approach to bound states in field theory
Authors: Felipe Bruno S. , Pitelli João P. M.
Published: May 2024

It is well known that (possibly nonunique) suitable field dynamics can be prescribed in spacetimes with timelike boundaries by means of appropriate boundary conditions. In [R. M. Wald, ], Wald derived a conserved energy functional for each prescribed dynamics. This conserved energy is related to the positive self-adjoint extensions of the spatial part A of the wave equation ∂2Φ/∂t2=−AΦ (A may not be, in principle, essentially self-adjoint). This is quite surprising since the canonical energy is not conserved in these cases. In this paper, we rederive this energy functional from an action principle (with appropriate boundary terms) following [A. A. Saharian, ] and consider field dynamics arising from nonpositive self-adjoint extensions of A. The spectrum of the resulting theory fails to be positive and unstable mode solutions for classical fields come to light. By studying fields in half-Minkowski spacetime, we illustrate that these unstable classical solutions come as a consequence of an inverted parabolic potential governing their dynamics. From the quantum mechanical point of view, this leads to an effective inverted harmonic oscillator at the boundary. We then explore these unstable modes behavior, as well as their instabilities, at the quantum level.

Published by the American Physical Society
2024
Beta functions of 2D adjoint QCD
Authors: Cherman Aleksey , Neuzil Maria
Published: May 2024

We discuss the long-distance physics of 2D adjoint QCD when it is viewed as an effective field theory and determine the β functions for its two classically marginal four-Fermi operators. These four-fermion terms preserve the invertible symmetries of the kinetic terms, and they have important implications at long distances if they are generated at short distances. Our results are likely to be important for future numerical lattice Monte Carlo studies of 2D adjoint QCD.

Published by the American Physical Society
2024
Class
S
theories on
S2
Authors: Nawata Satoshi , Pan Yiwen , Zheng Jiahao
Published: May 2024

We study two-dimensional N=(0,2) and N=(0,4) theories derived from compactifying class S theories on S2 with a topological twist. We present concise expressions for the elliptic genera of both classes of theories, revealing the topological quantum field theory structure on Riemann surfaces

C

g

,

n

. Furthermore, our study highlights the relationship between the left-moving sector of the (0,2) theory and the chiral algebra of the four-dimensional N=2 theory. Notably, we propose that the (0,2) elliptic genus of a theory of this class can be expressed as a linear combination of characters of the corresponding chiral algebra.

Published by the American Physical Society
2024
Enhancement of vibrationally assisted energy transfer by proximity to exceptional points, probed by fluorescence-detected vibrational spectroscopy
Authors: Li Zeng-Zhao , Whaley K. Birgitta
Published: May 2024

Emulation of energy transfer processes in natural systems on quantum platforms can further our understanding of complex dynamics in nature. One notable example is the demonstration of vibrationally assisted energy transfer (VAET) on a trapped-ion quantum emulator, which offers insights for the energetics of light harvesting. In this work, we expand the study of VAET simulation with trapped ions to a non-Hermitian quantum system comprising a PT-symmetric chromophore dimer weakly coupled to a vibrational mode. We first characterize exceptional points (EPs) and non-Hermitian features of the excitation energy transfer processes in the absence of the vibration, finding a degenerate pair of second-order EPs. Exploring the non-Hermitian dynamics of the whole system including vibrations, we find that energy transfer accompanied by absorption of phonons from a vibrational mode can be significantly enhanced near such a degenerate EP. Our calculations reveal a unique spectral feature accompanying the coalescing of eigenstates and eigenenergies that provides a unique approach to probe the degenerate EP by fluorescence-detected vibrational spectroscopy. Enhancement of the VAET process near the EP is found to be due to maximal favorability of phonon absorption at the degenerate EP, enabling multiple simultaneous excitations. Our work on improving VAET processes in non-Hermitian quantum systems paves the way for leveraging non-Hermiticity in quantum dynamics related to excitation energy transfer.

Published by the American Physical Society
2024
Finding regulatory modules of chemical reaction systems
Authors: Yamauchi Yuhei , Hishida Atsuki , Okada Takashi , Mochizuki Atsushi
Published: May 2024

Within a cell, numerous chemical reactions form chemical reaction networks (CRNs), which are the origins of cellular functions. We previously developed a theoretical method called structural sensitivity analysis (SSA), which enables us to determine, solely from the network structure, the qualitative changes in the steady-state concentrations of chemicals resulting from the perturbations to a parameter. Notably, if a subnetwork satisfies specific topological conditions, it is referred to as a buffering structure, and the effects of perturbations to the parameter within the subnetwork are localized to the subnetwork (the law of localization). A buffering structure can be the origin of modularity in the regulation of cellular functions generated from CRNs. However, an efficient method to search for buffering structures in a large CRN has not yet been established. In this study, we prove the “inverse theorem” of the law of localization, which states that a certain subnetwork exhibiting a confined response range is always a buffering structure. In other words, we are able to identify buffering structures in terms of confined responses rather than the topological conditions. By leveraging this property, we develop an algorithm to enumerate all buffering structures for a given network by calculating responses. Additionally, we show that the hierarchy of perturbed response patterns corresponds to that of buffering structures, and present a method to illustrate the hierarchy. Our method will be a powerful tool for understanding the regulation of cellular functions generated from CRNs.

Published by the American Physical Society
2024
Crystal structures of two new high-pressure oxynitrides with composition SnGe4N4O4, from single-crystal electron diffraction
Authors: Gollé-Leidreiter Philipp , Bhat Shrikant , Wiehl Leonore , Wen Qingbo , Kroll Peter , Ishikawa Ryo , Etter Martin , Farla Robert , Ikuhara Yuichi , Riedel Ralf , Kolb Ute
Published: May 2024

SnGe4N4O4 was synthesized at high pressure (16 and 20 GPa) and high temperature (1200 and 1500°C) in a large-volume press. Powder X-ray diffraction experiments using synchrotron radiation indicate that the derived samples are mixtures of known and unknown phases. However, the powder X-ray diffraction patterns are not sufficient for structural characterization. Transmission electron microscopy studies reveal crystals of several hundreds of nanometres in size with different chemical composition. Among them, crystals of a previously unknown phase with stoichiometry SnGe4N4O4 were detected and investigated using automated diffraction tomography (ADT), a three-dimensional electron diffraction method. Via ADT, the crystal structure could be determined from single nanocrystals in space group P63
mc, exhibiting a nolanite-type structure. This was confirmed by density functional theory calculations and atomic resolution scanning transmission electron microscopy images. In one of the syntheses runs a rhombohedral 6R polytype of SnGe4N4O4 could be found together with the nolanite-type SnGe4N4O4. The structure of this polymorph was solved as well using ADT.
Synthesis, crystal structure and Hirshfeld surface analysis of (3Z)-4-[(4-amino-1,2,5-oxadiazol-3-yl)amino]-3-bromo-1,1,1-trifluorobut-3-en-2-one
Authors: Guseinov Firudin I. , Çelikesir Sevim Türktekin , Akkurt Mehmet , Ovsyannikov Viacheslav O. , Ugrak Bogdan I. , Lavrova Oksana M. , Samigullina Aida I. , Bhattarai Ajaya
Published: May 2024

In the title compound, C6H4BrF3N4O2, the oxadiazole ring is essentially planar with a maximum deviation of 0.003 (2) Å. In the crystal, molecular pairs are connected by N—H...N hydrogen bonds, forming dimers with an R
2
2(8) motif. The dimers are linked into layers parallel to the (10\overline{4}) plane by N—H...O hydrogen bonds. In addition, C—O...π and C—Br...π interactions connect the molecules, forming a three-dimensional network. The F atoms of the trifluoromethyl group are disordered over two sites in a 0.515 (6): 0.485 (6) ratio. The intermolecular interactions in the crystal structure were investigated and quantified using Hirshfeld surface analysis.
Exploring seafood choices at the point of purchase among a sample of Swedish consumers
Authors: Costa Elena , Bergman Penny , Niimi Jun , Collier Elizabeth S.
Published: May 2024

Purpose

Seafood consumption in Sweden is below the national recommendations and limited to very few species. This study aims to explore the factors shaping seafood choices at the point of purchase among a sample of current consumers in Sweden, and examines their attitudes regarding seafood consumption more broadly.

Design/methodology/approach

Convenience sampling was used to recruit consumers planning to purchase seafood at a supermarket in Sweden. Participants’ shopping trip was recorded using wearable eye tracking glasses and, upon completion, semi-structured interviews were conducted using a cued retrospective think aloud method. This exploratory study integrates qualitative data (N = 39) with eye tracking data (N = 34), to explore how seafood choices unfold when consumers purchase at the point of purchase.

Findings

Purchases were mostly restricted to familiar seafood species. Four interlinked main themes were identified from thematic analysis of the interview data: Ambivalence, Nice and Necessary, Proficiency with Seafood and External Influences. Sustainability information (e.g. certifications) faced strong competition from other visual elements at the point of purchase, receiving less attention than product imagery and pricing information.

Originality/value

This study is the first to explore the factors shaping seafood choices of current consumers at the point of purchase. The unique approach, combining explicit and implicit measures, enriches understanding of the factors influencing seafood choices and how these may interrelate. The results are valuable for the industry and contribute to the literature by identifying possible routes to improve seafood sustainability communication.
The influence of linguistic profiling on perceived employability: a new application of the systems theory framework of career development
Authors: Greer Tomika W. , Mills Monique T. , Lapka Stefanie
Published: May 2024

Purpose

The purpose of this paper is to clarify the influence of linguistic profiling on perceived employability. In doing so, we recognize multiple factors that can contribute to this relationship. Using the systems theory framework (STF) of career development, we categorize these factors based on whether they primarily reside within the societal system, the organizational system, or the individual system. Subsequently, we construct and present an open systems model that depicts the influence of linguistic profiling on perceived employability in context with other societal, organizational and individual factors.

Design/methodology/approach

The STF provides a theoretical perspective on how to contextualize linguistic profiling and perceived employability within the scope of career development. We employed an integrative literature review method to locate existing research studies that investigated the influences of linguistic profiling and perceived employability. The literature search process, coupled with inclusion and exclusion criteria, resulted in 46 publications retained for analysis.

Findings

Findings provided evidence of language ideologies that contribute to linguistic profiling globally. Linguistic profiling usually results in reduced perceived employability. There was variation in the research findings based on the context of the research studies. The context consisted of the societal, organizational and individual systems in which the research study was conducted. Findings supported our construction of an open systems model of the influence of linguistic profiling on perceived employability, which is rooted in the STF.

Originality/value

This study highlights the negative influence of linguistic profiling on perceived employability. It also demonstrates how the STF can be used to contextualize the linguistic profiling problem within societal and organizational systems.
Optimization of an inductor for electromagnetic levitation melting
Authors: Nycz Błażej , Przyłucki Roman , Maliński Łukasz , Golak Slawomir
Published: May 2024

Purpose

The study aims to maximize the efficiency of the process under a given current condition by changing the geometry of the coil. This optimization is economically justified by reducing the cost of the process.

Design/methodology/approach

The paper presents the author’s optimization process for a case requiring long computational time. The presented optimization is based on a 3D simulation model of an electromagnetic levitation melting (ELM) inductor.

Findings

The result of the work is to find a suboptimal inductor geometry for ELM.

Research limitations/implications

To solve the presented problem, a procedure using an evolutionary algorithm was relied on. As for all global search algorithms, it is possible to find a local optimum instead of a global one.

Practical implications

The new inductor geometry for ELM, thanks to its higher process efficiency for its class of inductors, can lead to the reduction of the costs of the process by using this type of equipment.

Originality/value

The novelty of the article is a proprietary optimization algorithm and the use of an advanced 3D simulation model which was necessary due to the lack of symmetry of the ELM inductor.
Strategic-hybrid orientations and perceived business performance in medium/high-tech SMEs
Authors: Magalhães-Teixeira Antonio Manuel , Roldán José L. , Leal Millán Antonio Genaro
Published: May 2024

Purpose

This paper aims to investigate the direct and combined impacts of entrepreneurial orientation (EO) and conservative orientation (CO) on perceived business performance (PBP) of small- and medium-sized enterprises (SMEs) under strategic-hybrid orientation (SHO) theory.

Design/methodology/approach

The data collected from the SABI NEO international database has 90 companies in 13 medium-to-high and high-tech activity sectors. The authors used partial least squares structural equation modelling to test the research model.

Findings

Business strategies match a SHO that includes both orientations, i.e. EO and CO. Moreover, as expected, the authors found evidence that each orientation produces performance-related sign-opposite significant impacts. Finally, the hypothesis regarding the positive synergistic effect of both orientations (EO and CO) on PBP was also supported.

Research limitations/implications

One stems from the study’s cross-sectional nature, requiring a longitudinal approach. Another one resides in the absence of further examinations concerning multigroup analysis. Another restraint is the limitedness of data, focused on firms with med/high-tech intensity. For last, while the use of results in the initial stages of theory development can be beneficial, it is important to note that such results cannot be simply extrapolated or generalized to other industrial sectors without careful consideration of the contextual factors at play.

Social implications

This study humbly endeavours to contribute to the finality of SMEs’ more steady and prosperous existence concerning the consciousness of the need to improve labour stability and wage fairness, conditions such as requiring a continuous commitment.

Originality/value

In this study, the authors aimed to investigate the impact of SHO on SMEs’ PBP. To this end, the authors simultaneously used two different strategic orientations (SOs): EO, which is widely studied in the literature, and CO, which has been less researched. The authors also examined their synergistic effects on PBP. The authors’ approach is based on Venkatraman’s strategic orientation of business enterprises model and the comparative paradigm of SOs.
Open innovation for sustainability in the agri-food sector: why, who and how?
Authors: Krasnokutska Nataliia , Merino Amparo , Escudero Guirado Carmen , Díaz-Carmona Estela M.
Published: May 2024

Purpose

This paper examines open innovation (OI) based on sustainability principles within the agri-food sector. The study aims to understand the interplay between different actors and develop a typology of their roles in fostering sustainability. Three key research questions guided our inquiry: “WHY” sustainability is driving the OI initiatives as presented by companies, “WHO” participates in OI interactions and “HOW” these interactions are structured among diverse agri-food actors.

Design/methodology/approach

Through a theoretical prism encompassing OI modes, types, practices, sustainability dimensions and multilevel perspectives, we analyzed 78 agri-food sustainable OI initiatives, as described by the companies, to identify and explain why, who and how they engage in OI to drive sustainability shifts.

Findings

The results reveal typical patterns of transaction and cooperation between actors and confirm the collaborative nature of sustainable OI in the agri-food sector when actors must transcend traditional economic boundaries and reshape both the internal performance culture and the broader industrial or community mindset. The paper also conceptualizes the roles of actors in co-creating value in the context of sustainable food transitions.

Originality/value

This study brings the theoretical lenses of OI to conceptualize the collaborative nature of sustainability transitions in the agri-food system. The focus on sustainability transitions is dominantly placed on innovators at the niche level, while incumbents tend to be depicted as protecting the status quo. Thus, the focus on the collaborative interplay among different actors engaged in OI for sustainability contributes to offering a more nuanced view of innovation in sustainability transitions. In turn, the development of a typology of actors, motivations and configurations of OI from sustainability transition perspectives contributes to strengthening the conceptualization of sustainable value co-creation in the OI realm.
Testing the validity of feminization U-shape hypothesis for female labor force participation and economic development in Pakistan: a reexamination
Authors: Sajid Saima , Abdullah Norehan , Razak Chik Abdul
Published: May 2024

Purpose

The participation of females in economic activity remains a challenge, and received a lot of attention for a better labor policy discourse. The empirical research focused widely on the relationship between female labor force participation (FLFP) and economic development, called the feminization U-shape hypothesis. However, the linear/nonlinear relationship has been questioned due to empirical and methodological anomalies. Hence, this study aims to extend the previous work by reexamining this relationship in Pakistan.

Design/methodology/approach

The annual data from 1980 to 2021, the unit root tests augmented Dickey–Fuller and Phillips and Perron, the conventional autoregressive distributed lag bound test approach by including the quadratic-term of GDP per capita and the novel Sasabuchi–Lind–Mehlum (SLM) U test (2010) used for empirical estimation.

Findings

The findings revealed the prospects of a long-run nonlinear association between FLFP and economic development in Pakistan. However, an inverse U-shape exists between the female labor force participation rate (FLFPR) and GDP per capita, predicting that FLFP may decline in the future.

Research limitations/implications

The traditional feminization U-shape hypothesis has little empirical support in the case of Pakistan. Therefore, the Government of Pakistan should enhance the enabling environment for females through the provision of better job opportunities, technical skills, on-the-job training and social security benefits during all phases of economic development.

Originality/value

The conventional approach of testing U-shape is insufficient. To the best of the authors’ knowledge, therefore, this study incorporated a wider data set in a time series that is less evident, an advanced methodology SLM U test (2010), to validate the feminization U-shape hypothesis in Pakistan for the first time.
Exploring the potential for enhancing green skills training, innovation and sustainable livelihoods in informal spaces of Harare, Zimbabwe: identifying gaps and opportunities
Authors: Manyati Tarisai Kudakwashe , Kalima Billy Ganizani , Owolabi Temitope , Mutsau Morgen
Published: May 2024

Purpose

Despite growing emphasis on green skills, innovation, and sustainable livelihoods, research remains limited in the informal economy, particularly in developing countries. This study investigates gaps in green skills training, innovations and livelihoods among informal metal fabricators, shedding light on the challenges and opportunities within this sector. Specifically, the study critically assesses the potential for upskilling informal metal fabricators through Technical and Vocational Education and Training (TVET) institutions and university innovation hubs.

Design/methodology/approach

Employing a qualitative interpretive methodology, we conducted 40 key informant interviews with small-scale informal metal fabricators operating in Magaba and Gaza home industries, two of Harare’s largest home industries in Zimbabwe. Subsequent key informant interviews were held with TVET educators and innovation hub lecturers. Observations were carried out over a period of three months to comprehensively explore the issues under investigation.

Findings

Gender disparities persist within informal innovation spaces, with women making strides in the traditionally male-dominated field of metal fabrication. However, challenges such as prejudices, stigma, ridicule and abuse hinder women’s full participation in manufacturing processes, often relegating them to less physically demanding roles like customer engagement and product marketing. Inequities in support for green skills training were evident, with the innovation hub model primarily catering to formally educated youth in universities, neglecting the active involvement of notable informal innovators with limited formal education. While a gradual shift toward renewable energy sources is observable in the informal economy, government-owned TVET institutions show minimal or no adjustments in course content to incorporate essential green skills. In light of the findings, the study proposes measures to ensure equitable green skills training, innovation and the promotion of sustainable livelihoods in the informal metal fabrication sector.

Originality/value

The findings of this study represent a novel contribution the gaps in green skills training in the informal economy and how these inform reforms for vocational learning and training practices and the incubation of innovations.