bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antimicrobial activity of Lactiplantibacillus plantarum against shiga toxin-producing Escherichia coli
Authors: Ruiz María Julia , García Mauro Daniel , Canalejo Luis Manuel Medina , Krüger Alejandra , Padola Nora Lía , Etcheverría Analía Inés 
Published: September 2023

Abstract

Aims
The aim of the present work was to characterize the Lactiplantibacillus sp. LP5 strain, isolated from pork production, and identify bacteriocin-like inhibitory substances produced by this strain.

Methods and Results
In this study, LP5 was identified by species-specific PCR and 16S rRNA sequencing. Additionally, bacterial growth kinetics, antimicrobial activity, the detection of genes related to plantaricin production, and the genetic expression of plantaricins were determined. Lactiplantibacillus sp. LP5 was identified as Lactiplantibacillus plantarum. The well-diffusion test using cell-free supernatants (CFS), neutralized CFS, CFS treated with catalase, and CFS treated with proteinase K showed that inhibitory effects on a Shiga toxin-producing Escherichia coli (STEC) strain were produced by bacteriocins. The PCR technique allowed the detection of genes encoding E/F plantaricins, as well as J/K and whole genome sequencing, and bacteriocin mining analysis allowed us to confirm the presence of these plantaricins.

Conclusions
We can conclude that the inhibitory effect of L. plantarum LP5 isolated from pigs against the STEC EDL933 strain could be associated with the bacteriocins production and represents a potential use as a probiotic strain.
Bacteria intrinsic to Medicago sativa (alfalfa) reduce Salmonella enterica growth in planta
Authors: Vitt Jacob D , Hansen Eleanore G , Garg Raghav , Bowden Steven D 
Published: September 2023

Abstract

Aims
The purpose of this study was to determine whether plant-associated bacteria (PAB) can reduce Salmonella enterica colonization and infection of alfalfa sprouts to reduce the risk of foodborne illness.

Methods
We isolated PAB from alfalfa seeds and sprouts. Monoclonal isolates of the bacteria were obtained and tested for their ability to inhibit Salmonella Typhimurium growth in alfalfa sprouts over 6 days. Genome sequencing and annotation were used to construct draft genomes of the bacteria isolated in this study using Illumina sequencing platform.

Results
We observed that a cocktail of five PAB could reduce Salmonella growth in alfalfa sprouts from ∼108 to ∼105 CFU g−1, demonstrating a protective role. Genome sequencing revealed that these bacteria were members of the Pseudomonas, Pantoea, and Priestia genus, and did not possess genes that were pathogenic to plants or animals.

Conclusions
This work demonstrates that PAB can be utilized to reduce pathogen levels in fresh produce, which may be synergistic with other technologies to improve the safety of sprouts and other fresh produce.
A Theory of Power Structure and Institutional Compatibility: China versus Europe Revisited
Authors: Jia Ruixue , Roland Gérard , Xie Yang 
Published: September 2023

Abstract
To better understand institutional differences across space and time, we propose a two-dimensional framework of the power structure among three players in society: the degree of absolute power of the Ruler over the Elites and the People, and the degree of asymmetry between the latter two in terms of their everyday rights and power. Within this framework, we show that a more absolutist Ruler prefers a more balanced Elite–People relationship. This theory helps in particular to reconcile views on the comparison between imperial China and premodern Europe that would seem contradictory in one-dimensional or two-estate frameworks: the Ruler’s absolute power was weaker in Europe, whereas the Elite–People relationship was more balanced in China. Our approach also helps more generally to interpret specific institutions and other variations in power structures.
Traumatic Experiences Adversely Affect Life Cycle Labor Market Outcomes of the Next Generation—Evidence from Wwii Nazi Raids
Authors: Atella Vincenzo , Di Porto Edoardo , Kopinska Joanna , Lindeboom Maarten 
Published: September 2023

Abstract
This paper examines the causal effect of a traumatic event experienced by pregnant women on the life-long labor market outcomes of their offspring. We exploit a unique natural experiment that involved randomly placed Nazi raids in municipalities in Italy during WWII. We link administrative data on male private sector workers to information about Nazi raids and war casualties. Our results suggest that prenatal exposure to traumatic events affects offspring earnings throughout the working career and in retirement. The lower earnings are due to lower educational attainment, the type of jobs held, and interruptions in working careers due to unemployment. We further find that prenatal exposure exacerbates the adverse effects of later-life job loss on earnings. We use a medical database on health expenditures to interpret the effect estimates. The prenatally exposed have higher medical expenditures on diseases of the nervous system and mental disorders, indicating that stress is likely to be an important factor driving our findings.
A method for modeling DC potential fields in charged lossy dielectric media
Authors: Li Jinghe , He Zhanxiang , Bai Hanying 
Published: September 2023

Abstract
Numerical modeling of the direct current (DC) potential field for the mise-a-la-masse (MALM) method traditionally depends on the specific source under loss-free dielectric consideration. In this paper, we propose a numerical technique for modeling DC potential fields in charged lossy dielectric media. A numerical solver of charged current transportation is first presented using finite different method, then the DC potential is integrated from all unit current elements with the Legendre function polynomial. A new preconditioner is also proposed for MALM surveying to reduce the condition number to accurately solve the equation. This new technique is verified through comparisons with numerical cases and field surveys. The basic problem formulation is general, but it is directly applicable in MALM surveying as a geophysical technique where the DC potential produced by charged lossy dielectric media is of interest.
Investigation of virulence factors, phylogenetic grouping, multiple-locus variable number tandem repeat analysis, and antimicrobial susceptibility of E. coli isolated from aborted bovine fetal tissue
Authors: Özgen Ediz Kağan , Yanmaz Berna , Bağatir Perihan Şerifoğlu 
Published: September 2023

Abstract
Escherichia coli is an important microorganism for cattle breeding. The aim of this study was to investigate the presence of phylogenetic groups, virulence factors, genotyping with multi-locus variable tandem repeat analysis (MLVA), and susceptibility to commonly used antimicrobial agents in E. coli strains isolated from aborted bovine fetal samples. In this study, phylogrouping and various virulence genes were analyzed by PCR in E. coli strains isolated from 637 bovine fetal tissue samples. Consequently, E. coli was isolated and identified in 24 samples in culture. Of the 24 isolates identified as positive, 12.5% were defined as group A, 83.3% as B1, and 4.2% as group B2. Of the E. coli isolates, virulence factor fimH was identified in eight (33.3%), traT in 15 (62.5%), ompT in five (20.8%), CNF1 in one (4.16%), and CNF2 in six (25%). Seven genotypic groups were determined as a result of the analysis with the MLVA 10 method. According to the antimicrobial susceptibility test results, high resistance was determined against amoxicillin/clavulanic acid and oxytetracycline. In conclusion, strains of E. coli containing CNF1, CNF2, fimH, traT, and ompT virulence factors can be associated with bovine abortions. It is noteworthy that the dominant phylogenetic group B1 has been observed in cases of cattle abortions.
Phenotypical and molecular characterization of Acinetobacter spp. isolated from a pharmaceutical facility
Authors: Vasconcellos Luiza , Silva Samara Verly , da Costa Luciana Veloso , de Miranda Rebeca Vitoria da Silva Lage , dos Reis Cristhiane Moura Falavina , Braga Lygia Maria Paulo da Silva , Silva Claudiane , Conceição Greice , Mattoso Josiane , Silva Igor Barbosa , Forsythe Stephen J , Midlej Victor , Boas Maria Helena Simões Villas , Brandão Marcelo Luiz Lima 
Published: September 2023

Abstract
Characterizing microorganisms according to different criteria is useful when investigating sources of microbiological contamination in the pharmaceutical industry. The aim of this study was to characterize 38 Acinetobacter baumannii complex strains isolated from a biopharmaceutical industry by 16S rRNA sequencing, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI–TOF/MS), multilocus sequence typing (MLST), antimicrobial susceptibility profile, biofilm formation, and sensibility to disinfectants. Thirty-three (86.9%) strains were identified by 16S rRNA gene sequencing as A. seifertii/pitti/nosocomialis/lactucae, four (10.5%) as A. baumannii, and one (2.6%) as A. vivianii/courvalini. MALDI–TOF/MS did not identify one strain, and incorrectly identified 30/37 (81.1%) strains as A. baumannii. Strains were assigned to 12 different STs, of which nine were newly defined in this study (STs 2091–2099). Twenty-six (68.4%) strains showed resistance to amikacin and gentamicin. Thirty-three (86.8%) strains were classified as moderately or strongly adherent on polystyrene. Alcohol 70%/15 min and quaternary ammonium 0.08%/20 min were not able to eliminate the biofilm formed, but sodium hypochlorite 0.1%/15 min was efficient. In conclusion, improved methods are needed to improve the identification of Acinetobacter strains in pharmaceutical industries. This organism is of particular concern as it forms recalcitrant biofilms, leading to persistence in the manufacturing environment and increased risk of product contamination.
Late-time HST UV and optical observations of AT 2018cow: extracting a cow from its background
Authors: Inkenhaag Anne , Jonker Peter G , Levan Andrew J , Chrimes Ashley A , Mummery Andrew , Perley Daniel A , Tanvir Nial R 
Published: September 2023

ABSTRACT
The bright, blue, rapidly evolving AT 2018cow is a well-studied peculiar extragalactic transient. Despite an abundance of multiwavelength data, there still is no consensus on the nature of the event. We present our analysis of three epochs of Hubble Space Telescope (HST) observations spanning the period from 713 to 1474 d post-burst, paying particular attention to uncertainties of the transient photometry introduced by the complex background in which AT 2018cow resides. Photometric measurements show evident fading in the UV and more subtle but significant fading in the optical. During the last HST observation, the transient’s optical/UV colours were still bluer than those of the substantial population of compact, young, star-forming regions in the host of AT 2018cow, suggesting some continued transient contribution to the light. However, a compact source underlying the transient would substantially modify the resulting spectral energy distribution, depending on its contribution in the various bands. In particular, in the optical filters, the complex, diffuse background poses a problem for precise photometry. An underlying cluster is expected for a supernova occurring within a young stellar environment or a tidal-disruption event (TDE) within a dense older one. While many recent works have focused on the supernova interpretation, we note the substantial similarity in UV light-curve morphology between AT 2018cow and several tidal disruption events around supermassive black holes. Assuming AT 2018cow arises from a TDE-like event, we fit the late-time emission with a disc model and find MBH = 103.2 ± 0.8 M⊙. Further observations are necessary to determine the late-time evolution of the transient and its immediate environment.
Probing the jet size of two black hole X-ray binaries in the hard state
Authors: Prabu S , Miller-Jones J C A , Bahramian A , Wood C M , Tingay S J , Atri P , Plotkin R M , Strader J 
Published: September 2023

ABSTRACT
Using multifrequency very long baseline interferometry (VLBI) observations, we probe the jet size in the optically thick hard state jets of two black hole X-ray binary (BHXRB) systems, MAXI J1820+070 and V404 Cygni. Because of optical depth effects, the phase-referenced VLBI core positions move along the jet axis of the BHXRB in a frequency-dependent manner. We use this ‘core shift’ to constrain the physical size of the hard state jet. We place an upper limit of 0.3 au on the jet size measured between the 15 and 5 GHz emission regions of the jet in MAXI J1820+070, and an upper limit of 1.0 au between the 8.4 and 4.8 GHz emission regions of V404 Cygni. Our limit on the jet size in MAXI J1820+070 observed in the low-hard state is a factor of 5 smaller than the values previously observed in the high-luminosity hard state (using time lags between multifrequency light curves), thus showing evidence of the BHXRB jet scaling in size with jet luminosity. We also investigate whether motion of the radio-emitting region along the jet axis could affect the measured VLBI parallaxes for the two systems, leading to a mild tension with the parallax measurements of Gaia. Having mitigated the impact of any motion along the jet axis in the measured astrometry, we find the previous VLBI parallax measurements of MAXI J1820+070 and V404 Cygni to be unaffected by jet motion. With a total time baseline of 8 yr, due to having incorporated 14 new epochs in addition to the previously published ones, our updated parallax measurement of V404 Cygni is 0.450 ± 0.018 mas (2.226 ± 0.091 kpc).
Evolution of low mass population III stars from the pre-main sequence to the white dwarf cooling track
Authors: Lawlor T M , MacDonald J 
Published: September 2023

ABSTRACT
Radiation feedback from massive population III stars may have given rise to low mass star formation from primordial or nearly primordial material. If early Universe low mass stars did form, some should remain locally as white dwarfs, sub-giants, or main sequence stars. In this paper, we present model calculations for the evolution of single 0.8–3.0 M⊙ stars with primordial metallicity from pre-main sequence to the white dwarf cooling track, and calculations for the evolution of single 4.0–7.0 M⊙ stars which conclude in the giant phase. One goal of this work is to identify potential observable markers for potential observed progenitors of first or nearly first stars. We uncover a number of seemingly peculiar evolutionary differences between that of population III low mass stars compared with younger higher Z stars, as well as compared to other primordial evolution models. We also present an initial–final mass relationship and identify the minimum mass of a single white dwarf that could have had a population III progenitor.
Local magneto-shear instability in Newtonian gravity
Authors: Celora Thomas , Hawke Ian , Andersson Nils , Comer Gregory L 
Published: September 2023

ABSTRACT
The magneto-rotational instability (MRI), which is due to an interplay between a sheared background and the magnetic field, is commonly considered a key ingredient for developing and sustaining turbulence in the outer envelope of binary neutron star merger remnants. To assess whether (or not) the instability is active and resolved, criteria originally derived in the accretion disc literature, thus exploiting the symmetries of such systems, are often used. In this paper, we discuss the magneto-shear instability as a truly local phenomenon, relaxing common symmetry assumptions on the background on top of which the instability grows. This makes the discussion well suited for highly dynamical environments such as binary mergers. We find that, although this is somewhat hidden in the usual derivation of the MRI dispersion relation, the instability crucially depends on the assumed symmetries. Relaxing the symmetry assumptions in the background, we find that the role of the magnetic field is significantly diminished, as it affects the modes’ growth but does not drive it. We conclude by making contact with a suitable filtering operation, as this is key to separating background and fluctuations in highly dynamical systems.
The dusty Rossby wave instability (DRWI): linear analysis and simulations of turbulent dust-trapping rings in protoplanetary discs
Authors: Liu Hanpu , Bai Xue-Ning 
Published: September 2023

ABSTRACT
Recent numerical simulations have revealed that dust clumping and planetesimal formation likely proceed in ring-like disc substructures, where dust gets trapped in weakly turbulent pressure maxima. The streaming instability has difficulty operating in such rings with external turbulence and no pressure gradient. To explore potential paths to planetesimal formation in this context, we analyse the stability of turbulent dust-trapping ring under the shearing sheet framework. We self-consistently establish the pressure maximum and the dust ring in equilibrium, the former via a balance of external forcing versus viscosity and the latter via dust drift versus turbulent diffusion. We find two types of ≳ H-scale instabilities (H being the pressure scale height), which we term the dusty Rossby wave instability (DRWI). Type I is generalized from the standard Rossby wave instability (RWI, which is stationary at the pressure maximum and dominates in relatively sharp pressure bumps. Type II is a newly identified travelling mode that requires the presence of dust. It can operate in relatively mild bumps, including many that are stable to the standard RWI, and its growth rate is largely determined by the equilibrium gas and dust density gradients. We further conduct two-fluid simulations that verify the two types of the DRWI. While Type I leads strong to dust concentration into a large gas vortex similar to the standard RWI, the dust ring is preserved in Type II, and meanwhile exhibiting additional clumping within the ring. The DRWI suggests a promising path towards formation of planetesimals/planetary embryos and azimuthally asymmetric dust structure from turbulent dust-trapping rings.
A new tool to derive simultaneously exponent and extremes of power-law distributions
Authors: Pezzuto S , Coletta A , Klessen R S , Schisano E , Benedettini M , Elia D , Molinari S , Soler J D , Traficante A 
Published: September 2023

ABSTRACT
Many experimental quantities show a power-law distribution p(x) ∝ x−α. In astrophysics, examples are: size distribution of dust grains or luminosity function of galaxies. Such distributions are characterized by the exponent α and by the extremes xminxmax where the distribution extends. There are no mathematical tools that derive the three unknowns at the same time. In general, one estimates a set of α corresponding to different guesses of xminxmax. Then, the best set of values describing the observed data is selected a posteriori. In this paper, we present a tool that finds contextually the three parameters based on simple assumptions on how the observed values xi populate the unknown range between xmin and xmax for a given α. Our tool, freely downloadable, finds the best values through a non-linear least-squares fit. We compare our technique with the maximum likelihood estimators for power-law distributions, both truncated and not. Through simulated data, we show for each method the reliability of the computed parameters as a function of the number N of data in the sample. We then apply our method to observed data to derive: (i) the slope of the core mass function in the Perseus star-forming region, finding two power-law distributions: α = 2.576 between $1.06\, \mathrm{M}_{\odot }$ and $3.35\, \mathrm{M}_{\odot }$, α = 3.39 between $3.48\, \mathrm{M}_{\odot }$ and $33.4\, \mathrm{M}_{\odot }$; (ii) the slope of the γ-ray spectrum of the blazar J0011.4+0057, extracted from the Fermi-LAT archive. For the latter case, we derive α = 2.89 between 1484 MeV and 28.7 GeV; then we derive the time-resolved slopes using subsets of 200 photons each.
Dispersion and spatial structure of the coupled Alfvén and slow magnetosonic oscillations in the Solar corona
Authors: Petrashchuk Aleksandr V , Anfinogentov S A , Fedenev V V , Mager P N , Klimushkin D Yu 
Published: September 2023

ABSTRACT
Numerical and analytical analysis of the magnetohydrodynamic (MHD) waves in Solar coronal arcades is performed. A semicylinder slab model of arcade is used where the field lines are represented by half-circles intersecting the photosphere, the magnetic shells are represented by nested coaxial semicylinders. The finite plasma pressure is taken into account. The ‘corrugational’ perturbations are considered, that is, the perturbations with short wavelength in the direction along the arcade. In this limit, there are two oscillation modes, the Alfvén and slow magnetosonic modes, coupled due to the field line curvature. The transverse dispersion of the modes, that is, the dependence of the radial wave vector’s component kr on the wave frequency ω, is considered. It was found that the wave is concentrated in two regions of mode’s existence, where $k_r^2\gt 0$: the Alfvén and magnetosonic transparent regions. On one side, each of them is bounded by the resonance surface, where $k_r^2 \rightarrow \infty$. On the resonance surface, the wave’s frequency is determined by the Alfvén and slow magnetosonic modes dispersion relations, respectively. On the other side, the transparent regions are bounded by cut-off frequencies where $k_{r}^2 =0$. In both transparent regions, the perturbations have both transverse electric field (characteristic for the Alfvén mode) and field aligned velocity (characteristic for the slow mode). The wave structure along the field line for several models of plasma parameters is calculated.
The modulation effect of ice thickness variations on convection in icy ocean worlds
Authors: Kang Wanying 
Published: September 2023

ABSTRACT
It has been long puzzling whether the ice thickness variations observed on Enceladus can be sustained solely by a polar-amplified bottom heating. The key to this question is to understand how the upward heat transport by convective plumes would be interfered by the temperature and salinity variations beneath the ice due to the ice thickness variations, which, however, has yet to be explored. Here, we find that the horizontal temperature variation induced by the ice topography can easily be orders of magnitude greater than the vertical temperature variation induced by bottom heating using scaling analysis. Due to the dominance of horizontal temperature gradient, convective plumes are completely shut off by a stratified layer under the thin ice formed out of baroclinic adjustment, largely slowing down the vertical tracer transport. The stratified layer will also deflect almost all of the core-generated heating towards the regions with thicker ice shell, destroying the ice thickness gradient. These results allow us to put an upper bound on the core-generated heating on Enceladus, which is crucial for the estimate of habitability. Scaling laws for the bottom heat flux to penetrate the stratification are derived and examined. This scaling can be used to constrain the maximum ice thickness variations induced by heterogeneous bottom heating on icy satellites in general, which can be used to differentiate icy satellites that generate the majority of heat in the ice shell from those that generate the majority of heat in the silicate core.