bluuebunny/crossref_metadata_2025 huggingface dataset:
TIC 441725813: A new bright hybrid hot B subdwarf pulsator with differential core versus envelope rotation
Authors: Su Wenchao , Charpinet Stéphane , Latour Marilyn , Zong Weikai , Green Elizabeth M. , Li Gang
Published: July 2024

Context. The Transiting Exoplanet Survey Satellite (TESS) performs high-precision photometry over almost the whole sky primarily in search of exoplanet transits. It also provides exquisite data to study stellar variability, in particular for pulsating hot B subdwarf (sdB) stars.

Aims. We present a detailed analysis of a new hybrid (p- and g-mode) sdB pulsator, TIC 441725813 (TYC 4427-1021-1), discovered and monitored by TESS for 670 days.

Methods. The TESS light curves available for this star were analysed using prewhitening techniques to extract mode frequencies accurately. The pulsation spectrum was then interpreted through methods that include asymptotic period spacing relationships and the identification of rotational multiplets. We also exploited a high signal-to-noise ratio (S/N), low-resolution spectrum of TIC 441725813 using grids of non-local thermodynamic equilibrium (NLTE) model atmospheres to derive its atmospheric parameters.

Results. The light curve analysis reveals that frequencies are mostly found in the g-mode region, but several p-modes are also detected, indicating that TIC 441725813 is a hybrid sdB pulsator. We identify 25 frequencies that can be associated with ℓ = 1 g-modes, 15 frequencies corresponding to ℓ = 2 g-modes, and six frequencies characteristic of p-modes. Interestingly, several frequency multiplets interpreted as rotational splittings of deep-probing g-modes indicate a slow rotation period of at least 85.3 ± 3.6 day, while splittings of mostly envelope-probing p-modes suggest a significantly shorter rotation period of 17.9 ± 0.7 day, which implies the core (mainly the helium mantle with possibly the deeper partially mixed helium-burning core that it surrounds) rotates at least 4.7 times slower than the envelope. The radial velocity curves indicate that TIC 441725813 is in a close binary system with a low-luminosity companion, possibly a white dwarf. While elusive in the available TESS photometry, a low-frequency signal that would correspond to a period of ∼6.7 h is found, albeit at a low S/N. Furthermore, we estimate the inclination angle to be ∼60° by two independent means.

Conclusions. TIC 441725813 is a particularly interesting sdB star whose envelope rotates faster than the core. We hypothesise that this might be caused by the effects of a tidal interaction with a companion, although in the present case, the presence of such a companion will have to be further investigated. This analysis paves the way towards a more detailed seismic probing of TIC 441725813 using optimisation techniques, which will be presented in a second paper.
The CARMENES search for exoplanets around M dwarfs
Authors: Tabernero H. M. , Shan Y. , Caballero J. A. , Duque-Arribas C. , Montes D. , González Hernández J. I. , Zapatero Osorio M. R. , Schweitzer A. , Henning Th. , Cortés-Contreras M. , Quirrenbach A. , Amado P. J. , Reiners A. , Ribas I. , Bergond G. , Morales J. C.
Published: July 2024

We present the abundances of magnesium (Mg) and silicon (Si) for 314 dwarf stars with spectral types in the interval K7.0–M5.5 (Teff range ≈ 4200–3050 K) observed with the CARMENES high-resolution spectrograph at the 3.5 m telescope at the Calar Alto Observatory. Our analysis employs the BT-Settl model atmospheres, the radiative transfer code Turbospectrum, and a state-of-the-art selection of atomic and molecular data. These Mg and Si abundances are critical for understanding both the chemical evolution and assembly of the Milky Way and the formation and composition of rocky planets. Our chemical abundances show a line-to-line scatter at the level of 0.1 dex for all studied spectral types. The typical error bar of our chemical abundance measurements is ± 0.11 dex (Mg) and ± 0.16 dex (Si) for all spectral types based on the comparison of the results obtained for stellar components of multiple systems. The derived abundances are consistent with the galactic evolution trends and observed chemical abundance distribution of earlier FGK-type stars in the solar neighbourhood. Besides, our analysis provides compatible abundances for stars in multiple systems. In addition, we studied the abundances of different galactic stellar populations. In this paper, we also explore the relation of the Mg and Si abundances of stars with and without known planets.
JWST’s PEARLS: Resolved study of the stellar and dust components in starburst galaxies at cosmic noon
Authors: Polletta M. , Frye B. L. , Garuda N. , Willner S. P. , Berta S. , Kneissl R. , Dole H. , Jansen R. A. , Lehnert M. D. , Cohen S. H. , Summers J. , Windhorst R. A. , D’Silva J. C. J. , Koekemoer A. M. , Coe D. , Conselice C. J. , Driver S. P. , Grogin N. A. , Marshall M. A. , Nonino M. , Ortiz III R. , Pirzkal N. , Robotham A. , Ryan R. E. , Willmer C. N. A. , Yan H. , Arumugam V. , Cheng C. , Gim H. B. , Hathi N. P. , Holwerda B. , Kamieneski P. , Keel W. C. , Li J. , Pascale M. , Rottgering H. , Smith B. M. , Yun M. S.
Published: July 2024

Dusty star-forming galaxies (DSFGs) significantly contribute to the stellar buildup in galaxies during “cosmic noon,” the peak epoch of cosmic star formation. Major mergers and gas accretion are often invoked to explain DSFGs’ prodigious star formation rates (SFRs) and large stellar masses. We conducted a spatially resolved morphological analysis of the rest-frame ultraviolet/near-infrared (∼0.25–1.3 μm) emission in three DSFGs at z ≃ 2.5. Initially discovered as carbon monoxide (CO) emitters by NOrthern Extended Millimeter Array (NOEMA) observations of a bright (S350 μm = 111 ± 10 mJy) Herschel source, we observed them with the James Webb Space Telescope/NIRCam as part of the PEARLS program. The NIRCam data reveal the galaxies’ stellar populations and dust distributions on scales of 250 pc. Spatial variations in stellar mass, SFR, and dust extinction are determined in resolved maps obtained through pixel-based spectral energy distribution fitting. The CO emitters are massive (Mstar ≃ (3 − 30)×1010 M⊙), dusty starburst galaxies with SFRs ranging from 340 to 2500 M⊙ yr−1, positioning them among the most active star-forming galaxies at 2 < z < 3. Notably, they belong to the ∼1.5% of the entire JWST population with extremely red colors. Their morphologies are disk like (Sérsic index n ≃ 1), with effective radii of 2.0–4.4 kpc, and exhibit substructures such as clumps and spiral arms. The galaxies have dust extinctions up to AV = 5–7 mag extending over several kiloparsecs with asymmetric distributions that include off-center regions resembling bent spiral arms and clumps. The near-infrared dust-attenuation curve in these sources deviates from standard laws, possibly implying different dust–star geometries or dust grain properties than commonly assumed in starburst galaxies. The proximity (< 5″) of galaxies with consistent redshifts, strong color gradients, an overall disturbed appearance, asymmetric dust obscuration, and widespread star formation collectively favor interactions (minor mergers and flybys) as the mechanism driving the CO galaxies’ exceptional SFRs. The galaxies’ large masses and rich environment hint at membership in two proto-structures, as initially inferred from their association with a Planck-selected high-z source.
PSR J1227−6208 and its massive white dwarf companion: Pulsar emission analysis, timing update, and mass measurements
Authors: Colom i Bernadich Miquel , Venkatraman Krishnan Vivek , Champion David J. , Freire Paulo C. C. , Kramer Michael , Tauris Thomas M. , Bailes Matthew , Ridolfi Alessandro , Lower Marcus E. , Serylak Maciej
Published: July 2024

PSR J1227−6208 is a 34.53-ms recycled pulsar with a massive companion. This system has long been suspected to belong to the emerging class of massive recycled pulsar−ONeMg white dwarf systems such as PSR J2222−0137, PSR J1528−3146, and J1439−5501. Here, we present an updated emission and timing analysis with more than 11 years of combined Parkes and MeerKAT data, including 19 hours of high-frequency data from the newly installed MeerKAT S-band receivers. We measure a scattering timescale of 1.22 ms at 1 GHz with a flat scattering index of 3.33 < β < 3.62, and a mean flux density of 0.53 − 0.62 mJy at 1 GHz with a steep spectral index of 2.06 < α < 2.35. Around 15% of the emission is linearly and circularly polarised, but the polarisation angle does not follow the rotating vector model. Thanks to the sensitivity of MeerKAT, we successfully measure a rate of periastron advance of ω7 = 0.0171(11) deg yr−1, and a Shapiro delay with an orthometric amplitude of h3 = 3.6 ± 0.5 μs and an orthometric ratio of ς = 0.85 ± 0.05. The main source of uncertainty in our timing analysis is chromatic correlated dispersion measure noise, which we model as a power law in the Fourier space thanks to the large frequency coverage provided by the Parkes UWL receiver. Assuming general relativity and accounting for the measurements across all the implemented timing noise models, the total mass, companion mass, pulsar mass, and inclination angle are constrained at 2.3 < Mt/M⊙ < 3.2, 1.21 < Mc/M⊙ < 1.47, 1.16 < Mp/M⊙ < 1.69, and 77.5 < i/deg < 80.3. We also constrain the longitude of ascending node to either Ωa = 266 ± 78 deg or Ωa = 86 ± 78 deg. We argue against a neutron star nature of the companion based on the very low orbital eccentric of the system (e = 1.15 × 10−3), and instead classify the companion of PSR J1227−6208 as a rare, massive ONeMg white dwarf close to the Chandrasekhar limit.
Von Zeipel-Lidov-Kozai secondary resonances can enhance the excitation of planetary eccentricity
Authors: Zhao Shunjing , Huang Xiumin , Lei Hanlun
Published: July 2024

The von Zeipel-Lidov-Kozai (ZLK) effect has been applied to a wide range of dynamical circumstances, covering satellites and planets to supermassive black holes, in order to explain physical phenomena. The evolution of periodic orbit families associated with ZLK resonance under the octupole-level approximation exhibits distinctly different dynamical structures from the standard ZLK effect. In particular, bifurcations of periodic-orbit families commonly exist in planetary systems with a wide range of mass ratios. It is shown that such a phenomenon of bifurcation is triggered by ZLK secondary resonance, which is a new dynamical mechanism that has not appeared in previous studies. Numerical analysis shows that ZLK secondary resonance leads to a stronger excitation of eccentricity and/or inclination than the standard ZLK effect and that the level of enhancement is dependent on the initial eccentricity. The technique of perturbative treatments is adopted to study dynamical structures of ZLK secondary resonances, showing that there is an excellent agreement between analytical structures arising in phase portraits and numerical structures arising in Poincaré sections. Phase-space structures are produced for actual exoplanetary systems including HAT-P-11, HAT-P-13, and HAT-P-44, where large excitation of planetary eccentricity and/or inclination is expected due to the emergence of ZLK secondary resonance.
Secular aberration drift in stellar proper motions
Authors: Liu N. , Zhu Z. , Liu J.-C.
Published: July 2024

Context. The motion of the Solar System barycenter (SSB), the spatial origin of the International Celestial Reference System, causes a directional displacement known as secular aberration. The secular aberration drift caused by the galactocentric acceleration of the SSB has been modeled in the third generation of the International Celestial Reference Frame.

Aims. We aim to address another secular aberration drift effect due to the change in the line-of-sight direction and study its implications for stellar proper motions.

Methods. We derived a complete formula for the secular aberration drift and computed its influence on stellar proper motion based on the astrometric data in Gaia Data Release 3.

Results. We find that the secular aberration drift due to the change in the line-of-sight direction tends to decrease the observed proper motions for stars with galactic longitudes between 0° and 180°, and increase the observed proper motion for stars in the remaining region. If this secular aberration drift effect is ignored, it will induce an additional proper motion of > 1 mas yr−1 for 84 stars and > 0.02 mas yr−1 for 5 944 879 stars, which is comparable to or several times greater than the typical formal uncertainty of the Gaia proper motion measurements at G < 13.

Conclusions. The secular aberration drift due to the change in the line-of-sight direction and the acceleration of the SSB should be modeled to make the stellar reference frame consistent with the extragalactic reference frame.
Exploration abdominale en cas de coliques chroniques :
laparoscopie ou laparotomie ?
Authors: Robert Mickaël
Published: July 2024

L’investigation des coliques chroniques chez le cheval est une tâche difficile et souvent frustrante pour le vétérinaire, et qui demande un investissement émotionnel, temporel et financier important de la part du propriétaire. Une fois que les examens complémentaires classiques n’ont pas permis de trouver la cause de ces coliques, il est parfois nécessaire de recourir à un acte chirurgical.

La laparoscopie est peu invasive est permet une excellente visualisation de l’abdomen du cheval et de potentielles anomalies topographiques, adhérences, masses, ou anses intestinales anormales. Elle est réalisable sous sédation ou sous anesthésie générale. Toutefois malgré une bonne sensibilité, sa spécificité reste faible et dépend notamment de la position du laparoscope par rapport à la lésion.

La laparotomie peut s’effectuer sur cheval debout ou couché, par le flanc ou par abord ventral médian. L’exposition qu’elle offre est supérieure, permettant la réalisation de procédures plus invasives, mais certaines zones restent uniquement palpables et non extériorisables. De plus, elle est associée à de nombreuses complications et se révèle coûteuse.

La laparoscopie avec assistance manuelle combine les avantages des deux techniques et offre ainsi une excellente visualisation tout en utilisant la sensibilité tactile du chirurgien pour certaines manipulations délicates.

Dans tous les cas, la communication avec le propriétaire est primordiale car même si un acte chirurgical est réalisé, celui-ci ne sera parfois pas curatif, et parfois même pas diagnostique.
Advances in Photoinduced Minisci-like Reactions
Authors: Martos Mario , Bosque Irene , Gonzalez-Gomez Jose C.
Published: July 2024

The Minisci reaction, which has been around for more than five decades, is still the preferred tool for the straightforward alkylation of basic heteroarenes. The recent developments in photocatalysis have opened novel pathways for radical generation under milder and more sustainable conditions. Implementing this approach into the Minisci reaction has renewed interest in this transformation, which is attractive per se in Medicinal Chemistry. Aspects such as sacrificial oxidants, catalysts, and specific reaction conditions should be carefully examined to evaluate the practicability of the protocol. This short review focuses on recent advances (2020 to February 2024) in photoinduced Minisci-type reactions, emphasizing sustainability.

1 Introduction

2 Using Noble-Metal-Based Photocatalysts

3 Noble-Metal-Free Methods Using Sacrificial Oxidants

4 Noble-Metal-Free Methods Without Sacrificial Oxidants

5 Conclusions and Perspectives
Overuse Injury of the Epiphyseal Primary Physis
Authors: Caine Dennis , Patel Vandan , Nguyen Jie C.
Published: July 2024

Year-round participation in youth sport that involves high levels of repetitive movement fosters an environment in which overuse injuries are likely to occur. Epiphyseal primary physeal stress injuries (PSIs), unique to skeletally immature athletes, are a particular concern, given their potential for growth disturbance. Initially observed in Little League baseball players, these injuries are now known to affect the long bones around the shoulder, elbow, wrist, hand, knee, ankle, and foot of skeletally immature athletes involved in a variety of sport activities.

This article offers an epidemiological and radiologic perspective on the extent and distribution of epiphyseal PSIs in youth sport. We also review a novel framework for understanding the pathophysiologic mechanisms causing these injuries. This information is essential for the early identification of epiphyseal PSIs and devising preventive measures that can reduce a delayed diagnosis and long-term morbidity. Preventing and reducing injury to the epiphyseal growth plates is essential because impairment and dysfunction can result in lifelong morbidity and a risk of premature osteoarthritis.
Fetal and Maternal Factors Predictive of Primary Cesarean Delivery at Term in a Low-Risk Population: NICHD Fetal Growth Studies—Singletons
Authors: Mateus Julio , Stevens Danielle R. , Grantz Katherine L. , Zhang Cuilin , Grewal Jagteshwar , Grobman William A. , Owen John , Sciscione Anthony C. , Wapner Ronald J. , Skupski Daniel , Chien Edward , Wing Deborah A. , Ranzini Angela C. , Nageotte Michael P. , Newman Roger B.
Published: July 2024

Objective This study aimed to examine associations of fetal biometric and amniotic fluid measures with intrapartum primary cesarean delivery (PCD) and develop prediction models for PCD based on ultrasound parameters and maternal factors.

Study Design Secondary analysis of the National Institute of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies—singleton cohort (2009–2013) including patients with uncomplicated pregnancies and intent to deliver vaginally at ≥370/7 weeks. The estimated fetal weight, individual biometric parameters, fetal asymmetry measurements, and amniotic fluid single deepest vertical pocket assessed at the final scan (mean 37.5 ± 1.9 weeks) were categorized as <10th, 10th to 90th (reference), and >90th percentiles. Logistic regression analyses examined the association between the ultrasound measures and PCD. Fetal and maternal SuperLearner prediction algorithms were constructed for the full and nulliparous cohorts.

Results Of the 1,668 patients analyzed, 249 (14.9%) had PCD. The fetal head circumference, occipital–frontal diameter, and transverse abdominal diameter >90th percentile (adjusted odds ratio [aOR] = 2.50, 95% confidence interval [95% CI]: 1.39, 4.51; aOR = 1.86, 95% CI: 1.02, 3.40; and aOR = 2.13, 95% CI: 1.16, 3.89, respectively) were associated with PCD. The fetal model demonstrated poor ability to predict PCD in the full cohort and in nulliparous patients (area under the receiver-operating characteristic curve [AUC] = 0.56, 95% CI: 0.52, 0.61; and AUC = 0.54, 95% CI: 0.49, 0.60, respectively). Conversely, the maternal model had better predictive capability overall (AUC = 0.79, 95% CI: 0.75, 0.82) and in the nulliparous subgroup (AUC = 0.72, 95% CI: 0.67, 0.77). Models combining maternal/fetal factors performed similarly to the maternal model (AUC = 0.78, 95% CI: 0.75, 0.82 in full cohort, and AUC = 0.71, 95% CI: 0.66, 0.76 in nulliparas).

Conclusion Although a few fetal biometric parameters were associated with PCD, the fetal prediction model had low performance. In contrast, the maternal model had a fair-to-good ability to predict PCD.

Key Points
Utilizing Fetal Echocardiography to Risk Stratify and Predict Neonatal Outcomes in Fetuses Diagnosed with Congenital Heart Disease
Authors: Ro Sanghee S. , Milligan Ian , Kreeger Joe , Gleason Michelle E. , Porter Andrew , Border William , Ferguson M. Eric , Sachdeva Ritu , Michelfelder Erik
Published: July 2024

Objective Risk stratification of fetuses diagnosed with congenital heart disease (CHD) helps provide a delivery plan and prepare families and medical teams on expected course in the delivery room. Our aim was to assess the accuracy of echocardiographically determined risk-stratification assignments in predicting postnatal cardiac outcomes beyond the delivery room.

Study Design This was a retrospective study at a single center evaluating all fetuses with CHD who were risk-stratified by echocardiographically determined level of care (LOC) assignment, ranging from 1a (lowest risk) to 4 (highest risk). All data were collected from January 1, 2017, to November 1, 2021. Outcomes included any unexpected cardiac interventions and neonatal clinical outcomes including in-hospital mortality, the need for prostaglandins or inotropes, and defined critical illness. These outcomes were assessed for each LOC assignment by Fisher's exact test.

Results Out of 817 patients assigned a LOC, a total of 747 fetuses were included in our final cohort with a separate subanalysis of 70 fetuses diagnosed with coarctation of the aorta. The sensitivity and specificity were high for all LOC levels in predicting delivery room needs (93–100%). Higher LOC levels (3–4) had a lower positive predictive value (66–67%) indicating a high false-positive rate. Subjects with higher LOC assignments had a greater frequency of critical illness, hospital mortality, need for inotropes, need for neonatal surgical or catheterization interventions, and need for prostaglandins (p < 0.001 for all outcomes). A post-hoc analysis reviewing LOC assignments revealed a greater tendency to over-assign LOC at higher assignments (19% for LOC 3 and 4) compared to lower assignments (4% for LOC 1 and 2).

Conclusion Risk stratification based on fetal echocardiography can predict neonatal clinical outcomes and acuity of postnatal management needs. However, there is greater variability in expected clinical events and an expected degree of false positives for those with higher LOC assignments.

Key Points
Theory of the anomalous momentum exchange from wave–particle interactions in Hall-effect ion accelerators and comparisons with measurements
Authors: Mikellides Ioannis G. , Lopez Ortega Alejandro , Chaplin Vernon H.
Published: July 2024

A first-principles model of the anomalous momentum-transfer collision frequency for electrons (vea) in E×B ion accelerators, also known as Hall-effect thrusters, is presented. The theory on which the model is based adopts a two-stage evolution of unstable waves. First, short-wavelength (k⊥ρe>1), high-frequency (ω∼ωce) modes that are driven by the cross-field drift υE=E×B/B2 grow and saturate at a level of turbulence too low to explain the observed measurements. Then, the wave energy is dominated by modes of longer wavelength (k⊥ρe<1) and in the range of the lower-hybrid frequency ωLH=ωpi/1+ωpe2/ωce2½. The lower-hybrid modes combine wave growth in the azimuthal direction that is driven by the diamagnetic drift υDe=∇pe×B/enB2, with growth parallel to B due to a higher effective mass of electrons. The latter has been typically identified as the modified two-stream instability. The diamagnetic-driven modes are found to be important in regions of the channel where ions begin to accelerate since υE ∼ υDe there. The theoretical model compares extremely well with a large set of empirical profiles of vea derived from laser-induced fluorescence measurements. Our model validation comparisons spanned thrusters with >10× range in discharge power, various sizes and operating conditions, in unshielded and shielded magnetic field topologies. The kinetic version of our closed-form expression yields the scaling vea∼ωceυTieτ¯/(υE+υDe), where τ¯ ∼ ωLH/vi, vi is the sum of the ionization and charge-exchange frequencies and υTi is the ion thermal speed. The latter must be determined by the appropriate integration of the ion velocity distribution function and include not only random changes of the drift velocity but also ion production.
Flow characteristics and propulsive performance of oblique detonation waves induced by a transverse jet
Authors: Han Xin , Qiu Ruofan , You Yancheng
Published: July 2024

The initiation of oblique detonation waves (ODWs) is a key component of the successful application of oblique detonation wave engines (ODWEs). This paper numerically investigates the initiation of ODWs under the active control of a transverse jet by solving the two-dimensional multi-species Euler equations, focusing on the morphology of the flow fields as well as the relationship between the flow structures and propulsive performance using the concept of thrust potential. Active jet control significantly shortens the initiation length of the ODW. The results reveal that the jet-induced flow field shows four typical patterns depending on the jet momentum flux ratio and wedge angle: shock-induced combustion, a type I pattern, a type II pattern, and a type I-II pattern. For the jet-induced ODW flow field, the propulsive performance declines as the momentum flux ratio increases when the wedge angle is certain. The larger the wedge angle, the greater the magnitude of the decline. The thrust of the flow field consists of two main components: the thrust generated by the mixture that passes first through the oblique shock wave and then through the detonation wave, and the thrust generated by the mixture that passes directly through the ODW front. Since the ODW upstream front has a larger wave angle, the flow loss of the mixture passes through the ODW upstream front is higher and the thrust potential is lower. This work could guide the active control of the initiation of ODWs at low flow losses.
Investigations of vortex dynamics driven primary breakup in diesel spray based on multiphase lattice Boltzmann flux solver
Authors: Wang Yue , Li De-Ming , Liu Jun-Long , Zhao Fei-Yang , Yang Li-Ming , Yu Wen-Bin
Published: July 2024

During the fuel injection process, there is competition, merging, and entrainment between the Rayleigh–Taylor and Kelvin–Helmholtz instabilities, eventually leading to the formation of jet turbulence. The associated vortex dynamics is crucial for understanding the micro-evolution of surface waves on fuel spray. Considering the characteristics of fuel jet with large density ratios, a pressure-corrected multiphase lattice Boltzmann flux solver is proposed in this study, coupled with the Cahn–Hilliard model, to capture the micro-scale evolution of diesel spray. The spray evolution during the primary breakup, under simulated engine operating conditions, is systematically conducted by defining the parameters of vortex dynamics. According to the growth feature of vortex velocity, the microscopic evolution during the primary breakup can be divided into five stages: diffusion growth, exponential growth, potential flow growth, re-acceleration, and chaotic mixing (CM), providing a theoretical basis for the instability analysis of spray breakup. The growth of the Rayleigh–Taylor instability is determined by the competitive relationship between buoyancy and viscous dissipation forces. In cases of higher density ratios, the buoyancy-driven Kelvin–Helmholtz and the secondary growth Rayleigh–Taylor waves mutually advance, elongate, disintegrate, and finally breakup. Therefore, the influence of the density ratio on tail velocities shows a scenario of first promoting and then inhibiting. As the density ratio increases, the instability reaches the CM stage of asymmetric development more quickly by undergoing complex vortical motions. At this stage, there is a complicated phenomenology associated with the evolution of spray interface, including multiscale curling, severe deformation, vortex disintegration, and droplet breakup, eventually leading to turbulence.
A high precision instantaneous detonation model (hp-IDM) for condensed energetic materials and its application in underwater explosions
Authors: Yu Jun , Wang Jun , Zhang Xian-pi , Hao Yi , Jiang Xiong-wen , Shen Chao
Published: July 2024

The utilization of underwater explosion prediction programs incorporating explosives is not widespread in engineering at present, primarily due to the complexity associated with the detonation reaction process. The instantaneous detonation model (IDM) serves as a valuable tool for simulating underwater explosions due to its efficiency in engineering applications, disregarding the detonation reaction process. However, existing analytical solutions for the distribution of detonation gaseous products, based on the assumption of 1D isentropic flow, have limitations in accuracy. Moreover, alternative IDM approaches have not gained widespread recognition. In this study, we present a novel IDM, termed hp-IDM, which predicts fluid structure in the detonation zone using high-order solutions derived from the Detonation Shock Dynamics (DSD) model. The spatial aspect of the DSD model is discretized using fifth-order weighted essentially non-oscillatory reconstruction in characteristic space and Lax–Friedrich's splitting, while temporal terms are discretized via a third-order total variation diminishing Runge–Kutta scheme. Interface motion is captured using the level-set method combined with the modified ghost fluid method model, and a programmed burn model describes the generation and propagation of the detonation wave. We validate the self-similarity of detonation wave propagation using the DSD model and derive quantitative calculation formulas for the IDM by averaging or curve fitting dimensionless results. Subsequently, the hp-IDM model is established through high-order polynomial approximation of the Taylor rarefaction zone and the constant static zone for 1D planar, cylindrical, and spherical TNT charges. The application of the hp-IDM model involves direct mapping from the radial direction to spatial structured grids for 1D planar, 2D cylindrical, and 3D spherical shaped charges. Numerical results demonstrate that the hp-IDM model proposed in this paper achieves both high accuracy and computational efficiency.
The golden-backed tree-rat (Mesembriomys macrurus) (Peters 1876): reproduction, growth, development and behaviour in captivity
Authors: Kerle J. Anne , Fleming Michael R.
Published: July 2024

The golden-backed tree-rat (Mesembriomys macrurus) is a large semi-arboreal rodent that has suffered a significant reduction in range since European settlement. Seven (three male, four female) founding adults for a captive colony were captured on the Mitchell Plateau, Western Australia, and transferred to Alice Springs, Northern Territory. The reproduction, growth, development and behaviour of M. macrurus in captivity were recorded. Twenty-three litters were born with litter size of 1–3 (median litter size: 2; overall sex ratio parity). There was no apparent seasonality in breeding. Oestrous cycle (9.9 ± 0.4 days) and gestation (46.8 ± 2.8 days) were estimated from known births and birth dates determined from calculated growth curves. Mean weight at birth was 17.2 g (±1.3, n = 12) and growth of the young was rapid, with head length reaching the asymptote from 54 days and head-body length from 83 days. Young were weaned at about 40 days and adult pelage complete by 98 days. Reproductive maturity occurred from 5 to 6 months for females and in males testes became scrotal from 76 days. Developmental stages and captive behaviour were also recorded. These results are compared with reproduction and growth of the closely related black-footed tree-rat (M. gouldii) and brush-tailed rabbit-rat (Conilurus penicillatus).
The role of asprosin in regulating ovarian granulosa- and theca-cell steroidogenesis: a review with comparisons to other adipokines
Authors: Maylem Excel Rio S. , Schütz Luis Fernando , Spicer Leon J.
Published: July 2024

Adipose tissues produce a variety of biologically active compounds, including cytokines, growth factors and adipokines. Adipokines are important as they function as endocrine hormones that are related to various metabolic and reproductive diseases. The goal of this review was to summarise the role of asprosin, a recently discovered adipokine, and compare its role in ovarian steroidogenesis with that of other adipokines including adiponectin, leptin, resistin, apelin, visfatin, chemerin, irisin, and gremlin 1. The summary of concentrations of these adipokines in humans, rats and other animals will help researchers identify appropriate doses to test in future studies. Review of the literature indicated that asprosin increases androstenedione production in theca cells (Tc), and when cotreated with FSH increases oestradiol production in granulosa cells (Gc). In comparison, other adipokines (1) stimulate Gc oestradiol production but inhibit Tc androgen production (adiponectin), (2) inhibit Gc oestradiol production and Tc androstenedione production (leptin and chemerin), (3) inhibit Gc steroidogenesis with no effect on Tc (resistin), (4) inhibit Gc oestradiol production but stimulate Tc androgen production (gremlin 1), and (5) increase steroid secretion by Gc, with unknown effects on Tc steroidogenesis (apelin and visfatin). Irisin has direct effects on Gc but its precise role (inhibitory or stimulatory) may be species dependent and its effects on Tc will require additional research. Thus, most adipokines have direct effects (either positive or negative) on steroid production in ovarian cells, but how they all work together to create a cumulative effect or disease will require further research.
The importance of geography in forecasting future fire patterns under climate change
Authors: Syphard Alexandra D. , Velazco Santiago José Elías , Rose Miranda Brooke , Franklin Janet , Regan Helen M.
Published: July 2024

An increasing amount of California’s landscape has burned in wildfires in recent decades, in conjunction with increasing temperatures and vapor pressure deficit due to climate change. As the wildland–urban interface expands, more people are exposed to and harmed by these extensive wildfires, which are also eroding the resilience of terrestrial ecosystems. With future wildfire activity expected to increase, there is an urgent demand for solutions that sustain healthy ecosystems and wildfire-resilient human communities. Those who manage disaster response, landscapes, and biodiversity rely on mapped projections of how fire activity may respond to climate change and other human factors. California wildfire is complex, however, and climate–fire relationships vary across the state. Given known geographical variability in drivers of fire activity, we asked whether the geographical extent of fire models used to create these projections may alter the interpretation of predictions. We compared models of fire occurrence spanning the entire state of California to models developed for individual ecoregions and then projected end-of-century future fire patterns under climate change scenarios. We trained a Maximum Entropy model with fire records and hydroclimatological variables from recent decades (1981 to 2010) as well as topographic and human infrastructure predictors. Results showed substantial variation in predictors of fire probability and mapped future projections of fire depending upon geographical extents of model boundaries. Only the ecoregion models, accounting for the unique patterns of vegetation, climate, and human infrastructure, projected an increase in fire in most forested regions of the state, congruent with predictions from other studies.
Climate change and public health in California: A structured review of exposures, vulnerable populations, and adaptation measures
Authors: Jerrett Michael , Connolly Rachel , Garcia-Gonzales Diane A. , Bekker Claire , Nguyen Jenny T. , Su Jason , Li Yang , Marlier Miriam E.
Published: July 2024

California faces several serious direct and indirect climate exposures that can adversely affect public health, some of which are already occurring. The public health burden now and in the future will depend on atmospheric greenhouse gas concentrations, underlying population vulnerabilities, and adaptation efforts. Here, we present a structured review of recent literature to examine the leading climate risks to public health in California, including extreme heat, extreme precipitation, wildfires, air pollution, and infectious diseases. Comparisons among different climate-health pathways are difficult due to inconsistencies in study design regarding spatial and temporal scales and health outcomes examined. We find, however, that the current public health burden likely affects thousands of Californians each year, depending on the exposure pathway and health outcome. Further, while more evidence exists for direct and indirect proximal health effects that are the focus of this review, distal pathways (e.g., impacts of drought on nutrition) are more uncertain but could add to this burden. We find that climate adaptation measures can provide significant health benefits, particularly in disadvantaged communities. We conclude with priority recommendations for future analyses and solution-driven policy actions.
Huntingtin contains an ubiquitin-binding domain and regulates lysosomal targeting of mitochondrial and RNA-binding proteins
Authors: Fote Gianna M. , Eapen Vinay V. , Lim Ryan G. , Yu Clinton , Salazar Lisa , McClure Nicolette R. , McKnight Jharrayne , Nguyen Thai B. , Heath Marie C. , Lau Alice L. , Villamil Mark A. , Miramontes Ricardo , Kratter Ian H. , Finkbeiner Steven , Reidling Jack C. , Paulo Joao A. , Kaiser Peter , Huang Lan , Housman David E. , Thompson Leslie M. , Steffan Joan S.
Published: July 2024

Understanding the normal function of the Huntingtin (HTT) protein is of significance in the design and implementation of therapeutic strategies for Huntington’s disease (HD). Expansion of the CAG repeat in theHTTgene, encoding an expanded polyglutamine (polyQ) repeat within the HTT protein, causes HD and may compromise HTT’s normal activity contributing to HD pathology. Here, we investigated the previously defined role of HTT in autophagy specifically through studying HTT’s association with ubiquitin. We find that HTT interacts directly with ubiquitin in vitro. Tandem affinity purification was used to identify ubiquitinated and ubiquitin-associated proteins that copurify with a HTT N-terminal fragment under basal conditions. Copurification is enhanced by HTT polyQ expansion and reduced by mimicking HTT serine 421 phosphorylation. The identified HTT-interacting proteins include RNA-binding proteins (RBPs) involved in mRNA translation, proteins enriched in stress granules, the nuclear proteome, the defective ribosomal products (DRiPs) proteome and the brain-derived autophagosomal proteome. To determine whether the proteins interacting with HTT are autophagic targets, HTT knockout (KO) cells and immunoprecipitation of lysosomes were used to investigate autophagy in the absence of HTT. HTT KO was associated with reduced abundance of mitochondrial proteins in the lysosome, indicating a potential compromise in basal mitophagy, and increased lysosomal abundance of RBPs which may result from compensatory up-regulation of starvation-induced macroautophagy. We suggest HTT is critical for appropriate basal clearance of mitochondrial proteins and RBPs, hence reduced HTT proteostatic function with mutation may contribute to the neuropathology of HD.
Incomplete transcriptional dosage compensation of chicken and platypus sex chromosomes is balanced by post-transcriptional compensation
Authors: Lister Nicholas C. , Milton Ashley M. , Patel Hardip R. , Waters Shafagh A. , Hanrahan Benjamin J. , McIntyre Kim L. , Livernois Alexandra M. , Horspool William B. , Wee Lee Kian , Ringel Alessa R. , Mundlos Stefan , Robson Michael I. , Shearwin-Whyatt Linda , Grützner Frank , Graves Jennifer A. Marshall , Ruiz-Herrera Aurora , Waters Paul D.
Published: July 2024

Heteromorphic sex chromosomes (XY or ZW) present problems of gene dosage imbalance between sexes and with autosomes. A need for dosage compensation has long been thought to be critical in vertebrates. However, this was questioned by findings of unequal mRNA abundance measurements in monotreme mammals and birds. Here, we demonstrate unbalanced mRNA levels of X genes in platypus males and females and a correlation with differential loading of histone modifications. We also observed unbalanced transcripts of Z genes in chicken. Surprisingly, however, we found that protein abundance ratios were 1:1 between the sexes in both species, indicating a post-transcriptional layer of dosage compensation. We conclude that sex chromosome output is maintained in chicken and platypus (and perhaps many other non therian vertebrates) via a combination of transcriptional and post-transcriptional control, consistent with a critical importance of sex chromosome dosage compensation.
A nitrogen isotopic shift in fish otolith–bound organic matter during the Late Cretaceous
Authors: Rao Zixuan C. , Lueders-Dumont Jessica A. , Stringer Gary L. , Ryu Yeongjun , Zhao Kewei , Myneni Satish C. , Oleynik Sergey , Haug Gerald H. , Martinez-Garcia Alfredo , Sigman Daniel M.
Published: July 2024

The nitrogen isotopes of the organic matter preserved in fossil fish otoliths (ear stones) are a promising tool for reconstructing past environmental changes. We analyzed the
15
N/
14
N ratio (δ
15
N) of fossil otolith-bound organic matter in Late Cretaceous fish otoliths (of
Eutawichthys maastrichtiensis
,
Eutawichthys zideki
and
Pterothrissus
sp.) from three deposits along the US east coast, with two of Campanian (83.6 to 77.9 Ma) and one Maastrichtian (72.1 to 66 Ma) age. δ
15
N and N content were insensitive to cleaning protocol and the preservation state of otolith morphological features, and N content differences among taxa were consistent across deposits, pointing to a fossil-native origin for the organic matter. All three species showed an increase in otolith-bound organic matter δ
15
N of ~4‰ from Campanian to Maastrichtian. As to its cause, the similar change in distinct genera argues against changing trophic level, and modern field data argue against the different locations of the sedimentary deposits. Rather, the lower δ
15
N in the Campanian is best interpreted as an environmental signal at the regional scale or greater, and it may be a consequence of the warmer global climate. A similar decrease has been observed in foraminifera-bound δ
15
N during warm periods of the Cenozoic, reflecting decreased water column denitrification and thus contraction of the ocean’s oxygen deficient zones (ODZs) under warm conditions. The same δ
15
N-climate correlation in Cretaceous otoliths raises the prospect of an ODZ-to-climate relationship that has been consistent over the last ~80 My, applying before and after the end-Cretaceous mass extinction and spanning changes in continental configuration.
Supplementary comparison of the measurement of current transformers (CTs)
Authors: Akhmeev A A , Voronskay E V , Kikalo V N , Melkumyan E V , Dzhasinbekov O , Gantumur G , Volozhinskii D M
Published: July 2024

Main text

The purpose of conducting comparison COOMET.EM-S22 of reference measuring systems of the AC current ratio of national metrological institutes (NMIs) is to determine the degree of consistency of national standards among themselves in the participating countries.

Six NMIs participated in the supplementary comparison COOMET.EM-S22. Affiliated Branch of D I Mendeleev Institute for Metrology (VNIIM-UNIIM), Russian Federation, acted as the coordinating laboratory of the comparison.

The comparisons were carried out by comparing the measurement results of the characteristics of measuring current transformers (CTs), namely, the units of the coefficient and the angle of the scale conversion of the sinusoidal current at a frequency of 50 Hz.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
On the modes of nanosecond pulsed plasmas for combustion ignition of quiescent CH4-air mixtures
Authors: Jiang Chunqi , Dhotre Akash C , Lai Meimei , Biswas Sayan , MacDonald James R , Ekoto Isaac W
Published: July 2024

The effect of transient plasma modes on ignition kernel development are discussed here for a quiescent CH4-air combustion model system. A 10 ns high-voltage pulse was applied to a pin-to-pin electrode in lean fuel-air mixtures at room temperature and atmospheric pressure. High-impedance streamer, transient spark and low-impedance spark discharges were identified based on pulse waveforms of voltage and current. A sustained ignition kernel expansion was observed when the plasma discharge transitioned into a transient spark or spark discharge. The minimum ignition energy was obtained at the transient spark mode, which has less than a third of the energy or Coulomb transfer compared to the low-impedance spark. Employing repetitive 10-pulse sequence at 10 kHz, the lean-fuel limit was extended from an equivalence ratio of 0.6 for the single pulse ignition to 0.5. The use of repetitive pulses also allowed streamer breakdown or spark initiation to occur at a lower voltage.
Facile synthesis and characterization of Cu2Se thin films and self-powered p-Cu2Se/n-Si heterojunction with high-performance photoresponse
Authors: Lin Der-Yuh , Shih Yu-Tai , Qiu De-Jin , Kao Yee-Mou , Hwang Sheng-Beng , Kao Ming-Cheng , Lin Chia-Feng
Published: July 2024

A facile, cost-effective, and scalable chemical vapor deposition technique was used to synthesize p-type Cu2Se thin films on glass and n-type Si substrates. Thorough characterization confirmed the films’ β-phase structure with the correct stoichiometric ratio and exceptional crystalline quality, exhibiting behavior akin to a degenerate semiconductor. Measurements unveiled a work function of 4.83 eV and a bandgap of 2.13 eV for Cu2Se. The fabrication of a p-Cu2Se/n-Si heterojunction was achieved by depositing the p-type Cu2Se thin film onto the n-type Si substrate. The resulting heterostructure displayed rectification behavior, and its energy band diagram resembled a Schottky diode. Further exploration into its photoelectric properties showcased the p-Cu2Se/n-Si heterostructure’s favorable self-powered attribute, characterized by fast, steady, reproducible, sensitive, and robust photoresponsive performance. Consequently, it proves highly suitable for applications in high-frequency photodetectors. Additionally, the p-Cu2Se/n-Si heterojunction’s photovoltaic power conversion efficiency exceeded the reported values of the CuO/Si and Cu2O/Si systems. Here, this study contributes significantly to the pivotal evaluation of p-Cu2Se/n-Si heterostructures for promising optoelectronic applications.