bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinguishing laser-induced dissociation pathways of O
2 molecule based on alignment-dependent dissociation spectra in intense laser fields
Authors: Sun Renping , Xin Peipei
Published: September 2024

We experimentally investigate the dissociative single ionization process, O
2 → O
+ + O, of aligned O
2 molecule in intense laser fields. The yield of a vibrational structure in the kinetic energy release spectra is measured as a function of alignment angle. By quantitative comparison of the measured angle-dependent dissociation probability with the simulation of a classical model that considers ionization and thus additional interaction within the laser pulse, we are able to distinguish the dissociation pathway that contribute to the vibrational structure. It is found that for a relative low laser intensity, the vibrational structure are produced from the dissociation pathway of a
4Π
u
→ f
4Π
g
− 1ω. As the laser intensity increases, the increasing of the population probability of higher vibrational states and the absorbtion probability of more photons makes another two dissociation pathways open and become dominant.
A pattern reconfigurable hybrid graphene-metal terahertz MIMO antenna with improved isolation by metasurface absorber for 6G communication
Authors: Karimi Pardis , Moradi Khatereh
Published: September 2024

This paper introduces an innovative 2 × 2 MIMO, Multi-Input Multi-Output, antenna working in the sub-Terahertz (THz) band for 6G, 6-Generation, communications (0.1–1.2 THz). This antenna was designed with main metal octagonal patches and parasitic graphene elements, providing pattern reconfigurable antenna for Single-Input Single-Output (SISO) and MIMO applications. In the YZ-plane, aforementioned antenna illustrates a tunable pattern (0°, +70°, −70°) for SISO in three distinct states. In the XZ-plane, it obtains a versatile MIMO function with a controllable pattern (0°, ±20°, ±45°, ±75°) across four states, simultaneously. The adaptability of the radiation pattern is originated from changing graphene conductivity through biasing. In addition, a graphene metasurface was applied as an absorber, moderately improving isolation between 2 antenna elements, minimizing interference, and enhancing the overall system capability. The proposed schematization achieves a significant isolation up to −35 dB within the MIMO antenna’s operational frequency band. Moreover, the MIMO antenna touches a maximum gain of

9.5
dBi
,

maximum impedance bandwidth of approximately 91% during different states,

10
dBi

Diversity Gain, and

2.6
2
×

10

−
7

ECC in the resonance frequency, which demonstrates novelty designing, remarkable pros, and broad applications in the landscape evolution of 6G communication networks.
Exploring the influence of pH on structural and magnetic properties of lead-free double perovskite, La2CoFeO6 nanoparticles
Authors: Jharwal Swati , Gupta Anurag , Kar Manoranjan , Verma Vivek Kumar , Kumar Arvind
Published: September 2024

Lead free perovskite is at the center of the present study due to its multifunctional properties. In the present work, pH (0–5) of the solution during the synthesis of La2CoFeO6 (LCFO) nanoparticles has been varied to study its impact on structural and magnetic properties. X-ray diffraction(XRD) pattern confirms the formation of LCFO nanoparticle with pH variation. Rietveld refinement of the XRD patterns indicates that the LCFO is formed in mixed phase of orthorhombic and rhombohedral structure. The percentage contribution of orthorhombic phase decreases with an increase in the pH value. Morphological studies show the increment in the particle size with pH value (from ∼16 nm to ∼32 nm). Structural and morphological investigations indicate that LCFO prepared at pH 0 are highly agglomerated and may have some amorphous phases. Magnetization curves indicate the ferromagnetic response for the LCFO nanoparticles at pH-0. The maximum magnetization (M

S
) is found to decrease whereas coercivity (H

C
) increases with the increase in pH value. This could be attributed to the structural changes incorporated and presence of anti-site disorder due to the variation of pH. A large exchange bias effect has also been noticed at 60 K for all the LCFO samples.
Comprehensive evaluation of recombination confined performance of CuGaO2 for solar cell application
Authors: Vijayakumar S , Kumar Atul , Radhika R , Thandaiah Prabu R
Published: September 2024

In the quest to find an outstanding solar energy capturing system that meets requirements like affordability, widespread availability, eco-friendliness, remarkable efficiency, and enduring stability, thorough investigations have been carried out to explore the possibilities presented by ‘Delafossite’ copper gallium oxide (CuGaO2). β-CuGaO2 has an ideal bandgap of 1.5 eV, along with a high absorption coefficient and excellent carrier mobility, making it well-suited for high-efficiency solar cell applications. Theoretical modelling, utilizing the optical and electrical attributes of the CuGaO2 (CGO) material, is employed to analyze its photovoltaic performance when used as an absorber. The detailed balance analysis showed 56.9% of the incident power is wasted in spectrum loss (as thermalisation and non-absorption loss), 10.1% is wasted in intrinsic losses (such as radiative recombination, radiation dilution, entropy generation etc,), extrinsic recombination (originating from electrical losses, parasitic resistance, finite mobility, surface recombination velocity (SRV), non-ohmic contacts etc), eats up another 9.5% and the resultant 23.6% is available as net useful efficiency. Through the careful selection of a suitable buffer counterpart and optimization of material parameters, absorber thickness, defect density, contacts, and SRV, the CGO device dem onstrates an efficiency of 23.6%.
Search for MeV gamma-ray emission from TeV bright red dwarfs with COMPTEL
Authors: Shrivastava Niharika , Manna Siddhant , Desai Shantanu
Published: September 2024

The SHALON atmospheric Cherenkov telescope has detected very high energy gamma-ray
emission at TeV energies from eight red dwarfs, namely, V388 Cas, V547 Cas, V780 Tau, V962 Tau,
V1589 Cyg, GJ 1078, GJ 3684 and GL 851.1. Consequently, these red dwarfs have been suggested as
sources of ultra-high energy cosmic rays. In this work, we search for soft gamma-ray emission
from these TeV bright red dwarfs between 0.75–30 MeV using archival data from the COMPTEL
gamma-ray imaging telescope, as a follow-up to a similar search for GeV gamma-ray emission using
the Fermi-LAT telescope. Although, prima-facie, we detect non-zero photon flux from three red
dwarfs with high significance, these signals can attributed to contamination from nearby sources
such as Crab and Cygnus, which are within the angular resolution of COMPTEL, and have been
previously detected as very bright point sources at MeV energies. Therefore, we could not detect
any statistically significant signal (> 3σ) from any of these eight red dwarfs from 0.75–30 MeV. We then report the 95% confidence level upper limits on the differential photon flux (at 30 MeV), integral photon flux and integral energy flux for all of the eight red dwarfs. The integral
energy flux limits range between 10-11 - 10-10-ergs/cm2/s.
STORM image denoising and information extraction
Authors: Lu Yuer , Ying Yongfa , Huang Chengliang , Li Xiang , Cheng Jinyan , Yu Rongwen , Ma Lixiang , Shuai Jianwei , Zhou Xuejin , Zhong Jinjin
Published: September 2024

Stochastic optical reconstruction microscopy (STORM) is extensively utilized in the fields of cell and molecular biology as a super-resolution imaging technique for visualizing cells and molecules. Nonetheless, the imaging process of STORM is frequently susceptible to noise, which can significantly impact the subsequent image analysis. Moreover, there is currently a lack of a comprehensive automated processing approach for analyzing protein aggregation states from a large number of STORM images. This paper initially applies our previously proposed denoising algorithm, UNet-Att, in STORM image denoising. This algorithm was constructed based on attention mechanism and multi-scale features, showcasing a remarkably efficient performance in denoising. Subsequently, we propose a collection of automated image processing algorithms for the ultimate feature extractions and data analyses of the STORM images. The information extraction workflow effectively integrates automated methods of image denoising, objective image segmentation and binarization, and object information extraction, and a novel image information clustering algorithm specifically developed for the morphological analysis of the objects in the STORM images. This automated workflow significantly improves the efficiency of the effective data analysis for large-scale original STORM images.
Logistic regression approach on classifying air-pollution events: a parsimony technique
Authors: Masseran Nurulkamal
Published: September 2024

This study deals with the problem of classifying extreme and nonextreme air pollution events using the logistic regression technique, which is a model specifically developed for binary classification. Aiming at the features engineering of duration, intensity, and severity size of air pollution events, this study presents logistic regression as a parsimonious yet effective model. A case study was performed in Klang, Malaysia. Inductive learning with a basis of data mining framework was employed to train and test the accuracy of logistic regression. The results revealed a high precision and low generalization error for both extreme and nonextreme air pollution events. In conclusion, logistic regression is a suitable and efficient machine learning model for the classification of air pollution events. Further investigation is warranted to incorporate topological characteristics of air pollution events as additional features in training logistic regression models, which can potentially offer valuable insights into the behavior of air pollution events and improve the classification process.
The climate-energy nexus: a critical review of power grid components, extreme weather, and adaptation measures
Authors: Garland Jasmine , Baker Kyri , Livneh Ben
Published: September 2024

Extreme weather events and weather anomalies are on the rise, creating unprecedented struggles for the electrical power grid. With the aging of the United States power grid, the status quo for maintaining the transmission and distribution system, demand, generation, and operations will no longer suffice under the current and future conditions. Such conditions will require a shift in thinking and operating the power grid toward a weather-driven power system. This paper conducts a comprehensive review of each component of the power grid regarding the current leading weather events related to major power outages in the United States. For each event, contemporary issues and possible adaptations are presented, following a parallel comparison of the power grid development and knowledge of global climate modeling. Further, a background in global climate modeling is provided through the lens of an energy professional to aid in emission scenarios used in future studies. Overall, this paper works toward bridging the gap between weather and climate-related studies and operating the power grid in an uncertain climatic landscape while offering possible adaptations and solutions at a short-term and long-term scale.
On the maximal spectral type of nilsystems
Authors: Ackelsberg Ethan , Richter Florian , Shalom Or
Published: September 2024

Let

(
G

/

Γ
,

R
a

)

(G/\Gamma ,R_a)

be an ergodic

k
k

-step nilsystem for

k
≥
2

k\geq 2

. We adapt an argument of Parry [Topology 9 (1970), pp. 217–224] to show that

L
2

(
G

/

Γ
)

L^2(G/\Gamma )

decomposes as a sum of a subspace with discrete spectrum and a subspace of Lebesgue spectrum with infinite multiplicity. In particular, we generalize a result previously established by Host–Kra–Maass [J. Anal. Math. 124 (2014), pp. 261–295] for

2
2

-step nilsystems and a result by Stepin [Uspehi Mat. Nauk 24 (1969), pp. 241–242] for nilsystems

G

/

Γ

G/\Gamma

with connected, simply connected

G
G

.
Metric comparison of connectome-based lesion-symptom mapping in post-stroke aphasia
Authors: Ding Junhua , Thye Melissa , Edmondson-Stait Amelia J , Szaflarski Jerzy P , Mirman Daniel
Published: September 2024

Connectome-based lesion-symptom mapping relates behavioural impairments to disruption of structural brain connectivity. Connectome-based lesion-symptom mapping can be based on different approaches (diffusion MRI versus lesion mask), network scales (whole brain versus regions of interest) and measure types (tract-based, parcel-based, or network-based metrics). We evaluated the similarity of different connectome-based lesion-symptom mapping processing choices and identified factors that influence the results using multiverse analysis—the strategy of conducting and displaying the results of all reasonable processing choices. Metrics derived from lesion masks and diffusion-weighted images were tested for association with Boston Naming Test and Token Test performance in a sample of 50 participants with aphasia following left hemispheric stroke. ‘Direct’ measures were derived from diffusion-weighted images. ‘Indirect’ measures were derived by overlaying lesion masks on a white matter atlas. Parcel-based connectomes were constructed for the whole brain and regions of interest (14 language-relevant parcels). Numerous tract-based and network-based metrics were calculated. There was a high discrepancy across processing approaches (diffusion-weighted images versus lesion masks), network scales (whole brain versus regions of interest) and metric types. Results indicate weak correlations and different connectome-based lesion-symptom mapping results across the processing choices. Substantial methodological work is needed to validate the various decision points that arise when conducting connectome-based lesion-symptom mapping analyses. Multiverse analysis is a useful strategy for evaluating the similarity across different processing choices in connectome-based lesion-symptom mapping.
Landscape of the metaplasmidome of deep-sea hydrothermal vents located at Arctic Mid-Ocean Ridges in the Norwegian–Greenland Sea: ecological insights from comparative analysis of plasmid identification tools
Authors: Ciuchcinski Karol , Stokke Runar , Steen Ida Helene , Dziewit Lukasz
Published: September 2024

Plasmids are one of the key drivers of microbial adaptation and evolution. However, their diversity and role in adaptation, especially in extreme environments, remains largely unexplored. In this study, we aimed to identify, characterize, and compare plasmid sequences originating from samples collected from deep-sea hydrothermal vents located in Arctic Mid-Ocean Ridges. To achieve this, we employed, and benchmarked three recently developed plasmid identification tools—PlasX, GeNomad, and PLASMe—on metagenomic data from this unique ecosystem. To date, this is the first direct comparison of these computational methods in the context of data from extreme environments. Upon recovery of plasmid contigs, we performed a multiapproach analysis, focusing on identifying taxonomic and functional biases within datasets originating from each tool. Next, we implemented a majority voting system to identify high-confidence plasmid contigs, enhancing the reliability of our findings. By analysing the consensus plasmid sequences, we gained insights into their diversity, ecological roles, and adaptive significance. Within the high-confidence sequences, we identified a high abundance of Pseudomonadota and Campylobacterota, as well as multiple toxin–antitoxin systems. Our findings ensure a deeper understanding of how plasmids contribute to shaping microbial communities living under extreme conditions of hydrothermal vents, potentially uncovering novel adaptive mechanisms.
Isolation and characterization of Saccharomyces cerevisiae mutants with increased cell wall chitin using fluorescence-activated cell sorting
Authors: Chuene Lesiba Tyrone , Ndlovu Thulile , Rossouw Debra , Naidoo-Blassoples Rene Kathleen , Bauer Florian Franz
Published: September 2024

Yeast cell wall chitin has been shown to bind grape pathogenesis-related chitinases that are the primary cause of protein haze in wines, suggesting that yeast cell walls may be applied for haze protection. Here, we present a high-throughput screen to identify yeast strains with high cell wall chitin using a reiterative enrichment strategy and fluorescence-activated cell sorting of cells labelled with either GFP-tagged chitinase or Calcofluor white. To assess the validity of the strategy, we first used a pooled deletion strain library of Saccharomyces cerevisiae. The strategy enriched for deletion mutants with genes that had previously been described as having an impact on chitin levels. Genes that had not previously been linked to chitin biosynthesis or deposition were also identified. These genes are involved in cell wall maintenance and/or membrane trafficking functions. The strategy was then applied to a mutagenized population of a commercial wine yeast strain, S. cerevisiae EC1118. Enriched mutant strains showed significantly higher cell wall chitin than the wild type and significantly reduced the activity of chitinases in synthetic model wine, suggesting that these strains may be able to reduce haze formation in wine.
Genetic and biochemical characterization of OXA-1186, a novel OXA-198-type carbapenemase hydrolysing cephalosporins in Citrobacter freundii
Authors: Vanparis Oceane , Oueslati Saoussen , Girlich Delphine , Jousset Agnès B , Guyot Caroline , Delaval Anne , Naas Thierry , Dortet Laurent , Bonnin Rémy A
Published: September 2024

Objectives

This study described OXA-1186, a novel carbapenemase related to OXA-198 carbapenemase and produced by a clinical isolate of Citrobacter freundii.

Methods

WGS was used to characterize the resistome, virulome and plasmid types of the C. freundii 315C8 isolate and to reconstruct the blaOXA-1186-carrying plasmid. Disc diffusion and broth microdilution assays were used to determine MICs. The blaOXA-1186 gene was cloned into plasmid pTOPO and then transformed into Escherichia coli TOP10 or HB4. It was also cloned in pET41b and transformed into E. coli BL21 DE3 for protein purification. Steady-state kinetic parameters were determined on purified OXA-1186.

Results

C. freundii 315C8, belonging to ST8, was resistant to penicillins including temocillin and broad-spectrum cephalosporins and displayed reduced susceptibility to carbapenems. It was negative for one of the five main carbapenemases. WGS revealed that the blaOXA-1186 gene encoded a novel carbapenemase that shared 83% amino acid identity with OXA-198. The blaOXA-1186 gene was carried on an IncP6-type plasmid and was embedded within a class 1 integron. Cloning and expression in E. coli revealed that expression of the blaOXA-1186 gene conferred resistance to penicillins, cephalosporins and carbapenems, where it was associated with impaired outer membrane permeability. Kinetic parameters confirmed the hydrolysis of ceftazidime, cefepime and aztreonam, in addition to imipenem and meropenem.

Conclusions

Here, we described a novel carbapenemase, OXA-1186, identified in C. freundii. Unlike OXA-198, OXA-1186 is able to hydrolyse broad-spectrum cephalosporins. This carbapenemase was carried on a broad-spectrum IncP6 plasmid identified in other Citrobacter species and non-fermenters.
Spermidine supplementation influence on protective enzymes of Apis mellifera (Hymenoptera: Apidae)
Authors: Čelić Tatjana V , Đorđievski Srđana , Vukašinović Elvira L , Pihler Ivan , Kojić Danijela , Purać Jelena
Published: September 2024

Dietary supplementation has been proposed as a sustainable way to improve the health and resilience of honey bees (Apis mellifera, L.), as the decline in their numbers in recent decades has raised scientific, environmental, and economic concerns. Spermidine, a natural polyamine, has been shown to be a promising substance for honey bee supplementation, as its health-promoting effects have been demonstrated in numerous studies and in different organisms. As already shown, supplementation with spermidine at a certain concentration prolonged lifespan, reduced oxidative stress, and increased antioxidative capacity in honey bees. The aim of the present study was to investigate whether spermidine supplementation affects gene expression and/or enzyme activity of antioxidative and detoxification enzymes and immune response markers in honey bee workers. The different gene expression and enzyme activity patterns observed in abdominal and head tissues in response to spermidine supplementation suggest tissue-specific and concentration-dependent effects. In addition, the immune response markers suggest that spermidine has the ability to boost honey bee immunity. The observed changes make a valuable contribution to understanding the molecular mechanisms by which spermidine may exert its beneficial effects on the bee’s health and lifespan. These results support the idea of the use of spermidine supplementation to promote bee health and resilience to environmental stressors, emphasizing that the dose must be carefully chosen to achieve a balance between the pro- and antioxidant effects of spermidine.
Riparian plant community structure and assembly processes differed by variations in riverbank curvatures: implications for restoring habitats along the Three Gorges Reservoir
Authors: Li Xiaohong , Huang Jinxia , Bai Zuncheng , Zou Hang , Wang Wanyu , Qi Wanyu , Ma Maohua
Published: September 2024

A meandering riverbank plays a vital role in maintaining natural river ecosystems, providing habitats for riparian vegetation. However, dams have significantly altered riverbank shapes. To restore the riparian ecosystems, it is imperative to understand how different riverbank curvatures influence them. This study aims to uncover the ecological impacts of riverbank curvature on the structure and assembly process of plant communities in the riparian zone of the Yangtze River, regulated by the Three Gorges Dam (TGD) in China. We categorized the riparian zones into four types: cove, lobe, wavy and linear shapes. We documented the composition and diversity of riparian plant communities. Our findings revealed that wavy and cove riverbanks exhibited greater species diversity (with Shannon–Wiener diversity index values 1.5× higher) compared to communities along linear riverbanks. Furthermore, the analysis of functional traits indicated that wavy riverbanks promoted the differentiation of plant functional traits, thus enhancing ecosystem functions, with functional dispersion index (FDis) values 1.3 times higher than those of linear riverbanks. Significant variations in the assembly of riparian communities were also observed among different riverbanks, with standardized effect size (SES) values indicating a higher degree of niche differentiation in cove riverbanks (SES = 0.4) compared to linear riverbanks (SES = –0.6). These results highlight the ecological importance of diverse riverbank curvatures in influencing the diversity, structure and assembly of riparian communities along the waterway. In summary, this study underscores the necessity of maintaining or restoring various natural morphological curvatures when rehabilitating riparian communities along rivers impacted by human activities.
Fossil groups analysis using weak gravitational lensing
Authors: Castejon M , Cypriano E S , Vitorelli A Z
Published: September 2024

The overall objective of this study is to investigate claims found in the literature that fossil groups, characterized by a large magnitude gap between their two brightest galaxies, are darker, i.e. exhibit higher mass-to-light (M/L) ratios, compared to regular groups. Specifically, we aim to measure the mass of these systems using the weak gravitational lensing technique. To achieve this, we obtained deep images of four fossil systems with the CFHT telescope in the $r$ and g bands. Through a careful process of weak gravitational shear measurement, including corrections for the point spread function (PSF) and contamination from group and foreground galaxies, we fit NFW models and obtained mass measurements as a result. Similarly, we quantified the light distribution produced by these groups, taking into account relevant data gaps in the images due to the presence of bright stars, as well as contamination from foreground and background galaxies. We obtained masses and M/L ratios that are consistent with previous results where mass was estimated from galaxy dynamics. Indeed, the four fossil systems studied here exhibit high M/L ratios compared to the general population of systems. Drawing more generalizable conclusions from a sample of only four systems is challenging. However, the procedure outlined in this study can be applied to large image surveys, allowing for a revisiting of this question with significantly reduced statistical uncertainties. This will enable a more homogeneous comparison between fossil groups and clusters and the overall population.
Exploring the catastrophic regime: thermodynamics and disintegration in head-on planetary collisions
Authors: Dou Jingyao , Carter Philip J , Lock Simon , Leinhardt Zoë M
Published: September 2024

Head-on giant impacts (collisions between planet-sized bodies) are frequently used to study the planet formation process as they present an extreme configuration where the two colliding bodies are greatly disturbed. With limited computing resources, focusing on these extreme impacts eases the burden of exploring a large parameter space. Results from head-on impacts are often then extended to study oblique impacts with angle corrections or used as initial conditions for other calculations, for example, the evolution of ejected debris. In this study, we conduct a detailed investigation of the thermodynamic and energy budget evolution of high-energy head-on giant impacts, entering the catastrophic impacts regime, for target masses between 0.001 and 12 M$_{{\oplus }}$. We demonstrate the complex interplay of gravitational forces, shock dynamics, and thermodynamic processing in head-on impacts at high energy. Our study illustrates that frequent interactions of core material with the liquid side of the vapour curve could have cumulative effects on the post-collision remnants, leading to fragmentary disintegration occurring at lower impact energy. This results in the mass of the largest remnant diverging significantly from previously developed scaling laws. These findings suggest two key considerations: (1) head-on planetary collisions for different target masses do not behave similarly, so caution is needed when applying scaling laws across a broad parameter space; and (2) an accurate model of the liquid-vapour phase boundary is essential for modelling giant impacts. Our findings highlight the need for careful consideration of impact configurations in planetary formation studies, as head-on impacts involve a complex interplay between thermodynamic processing, shocks, gravitational forces, and other factors.
Relativistic X-ray reflection from the accreting millisecond X-ray pulsar IGR J17498−2921
Authors: Bhattacharya Mahasweta , Mondal Aditya S , Pahari Mayukh , Raychaudhuri Biplab , Ghosh Rohit , Dewangan Gulab C
Published: September 2024

The accreting millisecond X-ray pulsar IGR J17498−2921 went into X-ray outburst on 2023 April 13–15, for the first time since its discovery on 2011 August 11. Here, we report on the first follow-up NuSTAR observation of the source, performed on 2023 April 23, around 10 d after the peak of the outburst. The NuSTAR spectrum of the persistent emission (3–60 keV band) is well described by an absorbed blackbody with a temperature of $kT_{\mathrm{ bb}}=1.61\pm 0.04$ keV, most likely arising from the NS surface and a Comptonization component with power-law index $\Gamma =1.79\pm 0.02$, arising from a hot corona at $kT_{e}=16\pm 2$ keV. The X-ray spectrum of the source shows robust reflection features which have not been observed before. We use a couple of self-consistent reflection models, relxill and relxillCp , to fit the reflection features. We find an upper limit to the inner disc radius of $6\: R_{\mathrm{ ISCO}}$ and $9\: R_{\mathrm{ ISCO}}$ from relxill and relxillCp model, respectively. The inclination of the system is estimated to be $\simeq 40^{\circ }$ from both reflection models. Assuming magnetic truncation of the accretion disc, the upper limit of magnetic field strength at the pole of the NS is found to be $B\lesssim 1.8\times 10^{8}$ G. Furthermore, the NuSTAR observation revealed two type-I X-ray bursts and the burst spectroscopy confirms the thermonuclear nature of the burst. The blackbody temperature reaches nearly 2.2 keV at the peak of the burst.
White dwarf eccentricity fluctuation and dissipation by AGB convection
Authors: Cohen Yair , Ginzburg Sivan , Levy Maya , Bar Shalom Tal , Siman Tov Yoav
Published: September 2024

Millisecond pulsars with white dwarf companions have typical eccentricities $e\sim 10^{-6}{\!-\!}10^{-3}$. The eccentricities of helium white dwarfs are explained well by applying the fluctuation–dissipation theorem to convective eddies in their red giant progenitors. We extend this theory to more massive carbon–oxygen (CO) white dwarfs with asymptotic giant branch (AGB) progenitors. Due to the radiation pressure in AGB stars, the dominant factor in determining the remnant white dwarf’s eccentricity is the critical residual hydrogen envelope mass $m_{\rm env}$ required to inflate the star to giant proportions. Using a suite of mesa stellar evolution simulations with $\Delta m_{\rm c}=10^{-3}\, {\rm M}_{\odot }$ core-mass intervals, we resolved the AGB thermal pulses and found that the critical $m_{\rm env}\propto m_{\rm c}^{-6}$. The resulting eccentricity $e\sim 3\times 10^{-3}$ is almost independent of the remnant CO white dwarf’s mass $m_{\rm c}$. Nearly all of the measured eccentricities lie below this robust theoretical limit, indicating that the eccentricity is damped during the common-envelope inspiral that follows the unstable Roche lobe overflow of the AGB star. Specifically, we focused on white dwarfs with median masses $m_{\rm c}\gt 0.6\, {\rm M}_{\odot }$. These massive white dwarfs begin their inspiral with practically identical orbital periods and eccentricities, eliminating any dependence on the initial conditions. For this sub-sample, we find an empirical relation $e\propto P^{3/2}$ between the final period and eccentricity that is much tighter than previous studies – motivating theoretical work on the eccentricity evolution during the common envelope phase. The eccentricities of lower mass CO white dwarfs may be explained by alternative formation channels.
Agonistic song rate positively correlates with male breeding success and avian malaria infection in Acrocephalus paludicola (Aquatic Warbler), a promiscuous songbird with female-only parental care
Authors: Kubacka Justyna , Dubiec Anna , Souza Arantes Larissa , Herdegen-Radwan Magdalena , Mazzoni Camila J , Sparmann Sarah , Osiejuk Tomasz S
Published: September 2024

The link between male song and reproductive success has been explored at length in socially monogamous birds, but results were inconsistent and under-represented socially non-monogamous species with uniparental care. Here, we evaluated whether metrics of male song in Acrocephalus paludicola (Aquatic Warbler), a promiscuous songbird with female-only care and large repertoires, are associated with fitness- and quality-related traits. We showed that the number of 9-day-old nestlings fathered and probability of avian malaria infection increased with the rate of agonistic song, produced in male–male interactions, and that male scaled mass index (proxy for energy reserves) positively correlated with the repertoire size. The male breeding success was not explained by repertoire size and song duty cycle. None of the song variables clearly explained the male return rate or change in the tarsus length (proxy for structural body size) and scaled mass index of the fathered chicks between days 2 and 9 post-hatch. No other relationships between the song characteristics and the inbreeding coefficient, scaled mass index, wing-length and Trypanosoma infection status of the males were supported, and Plasmodium infection was unrelated to the song duty cycle and repertoire size. We conclude that in male A. paludicola the repertoire size could be a signal of early developmental stress or current body condition, and the agonistic song rate could be shaped by sexual selection and signal to females a genetic makeup that enhances survival upon infection by Plasmodium.
Effects of Antihypertensive Therapy During Pregnancy on Postpartum Blood Pressure Control
Authors: Martin Samantha L. , Kuo Hui-Chien , Boggess Kim , Dugoff Lorraine , Sibai Baha , Lawrence Kirsten , Hughes Brenna L. , Bell Joseph , Aagaard Kjersti , Gibson Kelly S. , Haas David M. , Plante Lauren , Metz Torri D. , Casey Brian M. , Esplin Sean , Longo Sherri , Hoffman Matthew , Saade George R. , Foroutan Janelle , Tuuli Methodius G. , Owens Michelle Y. , Simhan Hyagriv N. , Frey Heather A. , Rosen Todd , Palatnik Anna , Baker Susan , August Phyllis , Reddy Uma M. , Kinzler Wendy , Su Emily J. , Krishna Iris , Nguyen Nicki , Norton Mary E. , Skupski Daniel , El-Sayed Yasser Y. , Ogunyemi Dotun , Galis Zorina S. , Ambalavanan Namasivayam , Oparil Suzanne , Librizzi Ronald , Pereira Leonardo , Magann Everett F. , Habli Mounira , Williams Shauna , Mari Giancarlo , Pridjian Gabriella , McKenna David S. , Parrish Marc , Chang Eugene , Osmundson Sarah , Quinones JoAnne , Werner Erika , Szychowski Jeff M. , Tita Alan T. N. ,   for the CHAP Consortium
Published: September 2024

OBJECTIVE:

To compare differences in postpartum blood pressure (BP) control (BP below 140/90 mm Hg) for participants with hypertension randomized to receive antihypertensive treatment compared with no treatment during pregnancy.

METHODS:

This study was a planned secondary analysis of a multicenter, open-label, randomized controlled trial (The CHAP [Chronic Hypertension and Pregnancy] trial). Pregnant participants with mild chronic hypertension (BP below 160/105 mm Hg) were randomized into two groups: active (antihypertensive treatment) or control (no treatment unless severe hypertension, BP 160/105 mm Hg or higher). Study outcomes were BP control below 140/90 mm Hg (primary) and medication nonadherence based on a composite score threshold (secondary) at the 6-week postpartum follow-up visit. Participants without follow-up BP measurements were excluded from analysis of the BP control outcome. Participants without health care professional–prescribed antihypertensives at delivery were excluded from the analysis of the adherence outcome. Multivariable logistic regression was used to adjust for potential confounders.

RESULTS:

Of 2,408 participants, 1,684 (864 active, 820 control) were included in the analysis. A greater percentage of participants in the active group achieved BP control (56.7% vs 51.5%; adjusted odds ratio [aOR] 1.22, 95% CI, 1.00–1.48) than in the control group. Postpartum antihypertensive prescription was higher in the active group (81.7% vs 58.4%, P<.001), and nonadherence did not differ significantly between groups (aOR 0.81, 95% CI, 0.64–1.03).

CONCLUSION:

Antihypertensive treatment of mild chronic hypertension during pregnancy was associated with better BP control below 140/90 mm Hg in the immediate postpartum period.
The Thoracolumbar Injury Classification and Severity Score Appropriately Predicts Treatment in Children Aged 10 and Under
Authors: Metcalf Tyler , Paulson Ambika E. , Sborov Katherine D. , Moore-Lotridge Stephanie N. , Schoenecker Jonathan G. , Mencio Gregory A. , Martus Jeffrey E. , Louer Jr. Craig R.
Published: September 2024

Study Design.

Retrospective cohort study.

Objective.

This study aims to assess the validity of the Thoracolumbar Injury Classification and Severity Score (TLICS) in patients ≤10 years-old.

Summary of Background Data.

TLICS is a validated measure developed to help facilitate clinical decision-making regarding thoracolumbar spinal trauma in adults. Studies examining the utility of TLICS in children skew towards older pediatric patients, where the spine’s biomechanical properties are more similar to adults. Due to differences in a pre-adolescent spine compared to a more mature, adolescent spine, it is unclear if TLICS can be applied to younger patients.

Methods.

A single center spine trauma registry was queried for patients ≤10 with an acute, traumatic thoracolumbar fracture treated at a level-1 pediatric trauma center between 2006 and 2020. Test characteristics and Receiver-Operator Curve were used to evaluate TLICS based on TLICS <4=nonsurgical treatment and TLICS >4=surgery recommendation.

Results.

We identified 94 patients with traumatic thoracolumbar fractures (surgical=20; non-surgical=74). Despite TLICS-suggested operative management in 28 patients with TLICS>4, 9 (32.1%) were initially treated non-operatively. All patients who deviated from TLICS-suggested treatment had flexion-distraction injuries (FDI). Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 89.2%, 70.4%, and 100%, respectively. The receiver operating characteristic curve demonstrated strong diagnostic ability of TLICS in predicting need for surgery (area under the curve: 0.97, F1-score: 0.86).

Conclusion.

TLICS score <4 showed strong validity and is highly specific in predicting non-operative management for patients ≤10 years-old with thoracolumbar fractures. However, TLICS >4 has more limited specificity in indicating the necessity for surgical intervention, as many FDIs were successfully treated without surgery. Additional factors other than TLICS score may need to be considered for these more severe injuries to optimize management in this age group.
Codesign of a Quality Improvement Tool for Adults With Prolonged Critical Illness: A Modified Delphi Consensus Study
Authors: Allum Laura , Pattison Natalie , Connolly Bronwen , Apps Chloe , Cowan Katherine , Flowers Emily , Hart Nicholas , Rose Louise
Published: September 2024

OBJECTIVES:

Increasing numbers of patients experience a prolonged stay in intensive care. Yet existing quality improvement (QI) tools used to improve safety and standardize care are not designed for their specific needs. This may result in missed opportunities for care and contribute to worse outcomes. Following an experience-based codesign process, our objective was to build consensus on the most important actionable processes of care for inclusion in a QI tool for adults with prolonged critical illness.

DESIGN:

Items were identified from a previous systematic review and interviews with former patients, their care partners, and clinicians. Two rounds of an online modified Delphi survey were undertaken, and participants were asked to rate each item from 1 to 9 in terms of importance for effective care; where 1–3 was not important, 4–6 was important but not critical, and 7–9 was critically important for inclusion in the QI tool. A final consensus meeting was then moderated by an independent facilitator to further discuss and prioritize items.

SETTING:

Carried out in the United Kingdom.

PATIENTS/SUBJECTS:

Former patients who experienced a stay of over 7 days in intensive care, their family members and ICU staff.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

We recruited 116 participants: 63 healthcare professionals (54%), 45 patients (39%), and eight relatives (7%), to Delphi round 1, and retained 91 (78%) in round 2. Of the 39 items initially identified, 32 were voted “critically important” for inclusion in the QI tool by more than 70% of Delphi participants. These were prioritized further in a consensus meeting with 15 ICU clinicians, four former patients and one family member, and the final QI tool contains 25 items, including promoting patient and family involvement in decisions, providing continuity of care, and structured ventilator weaning and rehabilitation.

CONCLUSIONS:

Using experience-based codesign and rigorous consensus-building methods we identified important content for a QI tool for adults with prolonged critical illness. Work is underway to understand tool acceptability and optimum implementation strategies.
Effect of Virtual Education on Knowledge and Practice of Critical Care Nurses Regarding the Administration of Drugs Through Enteral Feeding Tubes
Authors: Sabaghnejad Elnaz , Nikvarz Naemeh , Nematollahi Monirsadat
Published: September 2024

A study was conducted to evaluate the effect of virtual education on knowledge and practice of nurses regarding administration of drugs through enteral feeding tubes (EFTs). Sixty nurses working in 4 intensive care units were enrolled. A questionnaire evaluating knowledge and practice of nurses regarding drug administration through EFTs was used. At the pre-intervention stage, all nurses responded to the questionnaire. Then an educational videoclip was provided to the intervention group. One month later, post-intervention stage, both groups answered to the questionnaire again. At the end of the study, the scores of all items in the knowledge domain including medication preparation (mean difference [MD] [95% CI]: 1.11 [0.57; 1.66]), tube flushing (MD [95% CI]: 2.15 [1.59; 2.79]), recognizing drug-drug/drug-feed interactions (MD [95% CI]: 0.57 [0.05; 1.09]), and recognizing dosage forms (MD [95% CI]: 1.51 [0.94; 2.10]) and practice domain including medication preparation (MD [95% CI]: 1.63 [1.04; 2.21]), tube flushing (MD [95% CI]: 1.19 [0.64; 1.74]), and recognizing drug-drug/drug-feed interactions [MD (95% CI): 2.16 (1.53; 2.80)] in the intervention group were significantly higher than those in the control group (P < .05). Education of proper technics of preparation and administration of drugs through EFTs improved knowledge and practice of the participants.
Impact of quality indicators on variability of keratometry measurements using a SS-OCT–based optical biometer
Authors: Cannon Nathan T. , Cooke David L. , Wendelstein Jascha A. , Lehman Erik , Pantanelli Seth M.
Published: September 2024

Purpose:

To characterize the variability of keratometry measurements on the IOLMaster 700 and relate it to device image quality indicators (QIs).

Setting:

2 academic centers and 1 private practice.

Design:

Multicenter, retrospective consecutive case series.

Methods:

Measurements from 3 sites, obtained between December 2015 and July 2023, were included. Surgery-naïve phakic eyes with same-day sequential measurements on the same eye were identified. Repeat measurement pairs were grouped by IOLMaster QIs (success vs warning), and changes in mean standard keratometry (∆Kmean) and total keratometry (∆TKmean) as well as standard astigmatism (∆Kastig) and total astigmatism (∆TKastig) vectors were calculated.

Results:

Analysis was performed on 3222 eyes of 1890 patients. Measurement “success” was associated with a smaller ΔKmean (0.09 ± 0.14 diopters [D]) and ΔTKmean (0.11 ± 0.16 D) when compared with pairs in which both measurements had a “warning” (0.25 ± 0.32 D and 0.14 ± 0.17 D, respectively; P < .0001). A similarly smaller ∆Kastig (0.26 ± 0.28 D) and ∆TKastig (0.28 ± 0.30 D) were observed with measurement “success” vs “warning” (0.77 ± 0.79 D and 0.42 ± 0.41 D, respectively; P < .0001). Even when both measurements were successful, the proportion of measurement pairs that had a ∆Kastig >0.50 D increased from 14% to 24% to 32% when Kmean SD was ≥0.01, 0.05, and 0.10 D, respectively.

Conclusions:

When measurement quality is poor, TK varies less than standard K measurements. Clinicians may use the SD of Kmean/TKmean to estimate the repeatability of measurements and balance this against their tolerance for performing repeat measurements.
Risk Factors for Delayed Treatment of Gonorrhea and Chlamydia in Active-Duty Service Members
Authors: Quackenbush David A. , Smalley Joshua M. , Herbold John , Landt Cristy L. , Vance Bryce A. , Hansen Shana L.
Published: September 2024

Background

Sexually transmitted infections including gonorrhea and chlamydia are common in the active-duty military population, with historically higher rates than their civilian counterparts. Prevention and screening are 2 of the main strategies used to reduce the chronic medical complications and costs associated with untreated gonorrhea and chlamydia; however, there is little information in the literature regarding treatment time after a positive screening. To our knowledge, there has not yet been a study regarding delayed treatment of gonorrhea and chlamydia in the active-duty population.

Methods

We performed a population-based retrospective observational study on active-duty service members (ADSMs) diagnosed with gonorrhea and chlamydia from 2010–2019. Statistical analysis was performed to determine differences in treatment times for key demographics. This study was reviewed and approved by the Brooke Army Medical Center Institutional Review Board.

Results

Average treatment time was 3.5 days for individuals with chlamydia and 5 days for those with gonorrhea. Treatment within 2 weeks was met for 94% of people diagnosed with chlamydia and 91% of people diagnosed with gonorrhea. Delay in treatment times for chlamydia were seen in men, ages 25–34, full-time active-duty service members, those with a history of prior infection, and soldiers in the Army. Gonorrhea treatment times were delayed in men, members of the Coast Guard, ages 35–44, and those with a history of prior infection.

Conclusions

Significant differences in treatment time were seen based on sex, age, branch of service, rank, and history of prior infection.
A Rare Mutation in MESP1 Increases the Risk of Congenital Heart Disease
Authors: Peng Rui , Huang Li-Juan , Zhou Xiang-Yu , Lei Bing-Kun , Li Pei-Qiang
Published: September 2024

Objective:

In this study, we aim to screen MESP1 variants in congenital heart disease (CHD), and explore the biological functions of these variants.

Methods:

Targeted sequencing was used to screen MESP1 variants in a cohort of patients with CHD and healthy controls from Shandong Province, China, and confirm the variants with Sanger sequencing. Dual-luciferase reporter assay was used to assess the effects of MESP1 variants on the expression of downstream target genes in HEK293T and H9C2 cells. Binding affinity with NKX2-5 between variants and wild-type MESP1 was detected in HEK293T cells using an electrophoretic gel mobility shift assay (EMSA). The teratogenic effects of the MESP1 variants compared to the wild-type were explored with zebrafish embryo microinjection.

Results:

We identified two rare mutations, namely c.359T>C (p.L120P) and c.526A>T (p.T176S), in MESP1. The impact of these mutations was investigated using dual-luciferase reporter assay. Our findings demonstrate that compared to the wild-type, the mutation c.359T>C (p.L120P) significantly inhibits the expression of downstream target genes, whereas the mutation c.526A>T (p.T176S) does not exhibit altered activity. Further insights from EMSA revealed that the mutation c.359T>C (p.L120P) displays a reduced binding affinity with NKX2-5. Notably, our investigation involving zebrafish embryo microinjection unveiled a significant increase in the rate of malformation associated with the mutation c.359T>C (p.L120P).

Conclusions:

Two rare mutations in MESP1 were identified in the CHD cohort. Our in vitro and in vivo studies showed that MESP1 c.359T>C (p.L120P) is a loss-of-function mutation that may increase the risk of CHD.