bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Factors Associated With Congenital Syphilis in Missouri
Authors: Daniels Elizabeth , Atkinson Andrew , Cardoza Nicholas , Ramakrishnan Aditi , Willers Denise , Reno Hilary
Published: May 2024

Background

Congenital syphilis disproportionately affects individuals impacted by adverse social determinants of health. Understanding these determinants may help facilitate holistic care.

Methods

We performed a retrospective review of mother-infant dyads with potential congenital syphilis in a Missouri hospital system. Cases were classified per Centers for Disease Control and Prevention clinical scenarios. Information was collected regarding demographics, prenatal care, substance use, and other social factors. Dyads with confirmed/highly probable or possible congenital syphilis (“congenital syphilis outcomes”) were compared to those with less likely/unlikely congenital syphilis (“noncongenital syphilis outcomes”) using descriptive statistics.

Results

We identified 131 dyads with infant dates of birth from 2015 to 2022: 74 (56%) with congenital syphilis outcomes and 56 (43%) with noncongenital syphilis outcomes. Most mothers were Black/African American (n = 84 [65%]) and lived in areas with a high Social Vulnerability Index. Many had inadequate prenatal care (n = 61 [47%]) and/or had substance use histories (n = 55 [42%]). Significant associations (odds ratio [95% confidence interval]) with congenital syphilis outcomes included limited prenatal care (3.01 [1.38–6.56]), no prenatal care (16.08 [1.96–132.11]), substance use (3.42 [1.61–7.25]), housing instability (3.42 [1.39–8.38]), and justice system interactions (2.29 [1.00–5.24]). Substance use correlated with prenatal care adequacy (P < .001). One-third of infants with congenital syphilis outcomes were taken into protective custody.

Conclusions

Adverse social determinants of health are common in dyads impacted by congenital syphilis. Health systems should consider interdisciplinary programming to improve testing and linkage to care. Future studies should evaluate social support for congenital syphilis prevention and management.
Portal vein Doppler tracks volume status in patients with severe tricuspid regurgitation: a proof-of-concept study
Authors: Alday-Ramírez Sergio M , Leal-Villarreal Mario Andrés de Jesús , Gómez-Rodríguez César , Abu-Naeima Eslam , Solis-Huerta Fernando , Gamba Gerardo , Baeza-Herrera Luis A , Araiza-Garaygordobil Diego , Argaiz Eduardo R
Published: May 2024

Aims

Renal and liver congestion are associated with adverse outcomes in patients with tricuspid regurgitation (TR). Currently, there are no valid sonographic indicators of fluid status in this population. Intra-renal venous Doppler (IRVD) is a novel method for quantifying renal congestion but its interpretation can be challenging in severe TR due to altered haemodynamics. This study explores the potential of portal vein Doppler (PVD) as an alternative marker for decongestion during volume removal in patients with severe TR.

Methods and results

Forty-two patients with severe TR undergoing decongestive therapy were prospectively enrolled. Inferior vena cava diameter, PVD, and IRVD were sequentially assessed during volume removal. Improvement criteria were portal vein pulsatility fraction (PVPF) < 70% and renal venous stasis index (RVSI) < 0.5 for partial improvement, and PVPF < 30% and RVSI < 0.2 for complete improvement. After volume removal, PVPF significantly improved from 130 ± 39% to 47 ± 44% (P < 0.001), while IRVD improved from 0.72 ± 0.08 to 0.54 ± 0.22 (P < 0.001). A higher proportion of patients displayed improvement in PVD compared to IRVD (partial: 38% vs. 29%, complete: 41% vs. 7%) (P < 0.001). Intra-renal venous Doppler only improved in patients with concomitant improvement in severe TR. Portal vein Doppler was the only predictor of achieving ≥5 L of negative fluid balance [area under the ROC curve (AUC) 0.83 P = 0.001].

Conclusion

This proof-of-concept study suggests that PVD is the only sonographic marker that can track volume removal in severe TR, offering a potential indicator for decongestion in this population. Further intervention trials are warranted to determine if PVD-guided decongestion improves patient outcomes in severe TR.
Prospects for artificial intelligence-enhanced electrocardiogram as a unified screening tool for cardiac and non-cardiac conditions: an explorative study in emergency care
Authors: Strodthoff Nils , Lopez Alcaraz Juan Miguel , Haverkamp Wilhelm
Published: May 2024

Aims

Current deep learning algorithms for automatic ECG analysis have shown notable accuracy but are typically narrowly focused on singular diagnostic conditions. This exploratory study aims to investigate the capability of a single deep learning model to predict a diverse range of both cardiac and non-cardiac discharge diagnoses based on a single ECG collected in the emergency department.

Methods and results

In this study, we assess the performance of a model trained to predict a broad spectrum of diagnoses. We find that the model can reliably predict 253 ICD codes (81 cardiac and 172 non-cardiac) in the sense of exceeding an AUROC score of 0.8 in a statistically significant manner.

Conclusion

The model demonstrates proficiency in handling a wide array of cardiac and non-cardiac diagnostic scenarios, indicating its potential as a comprehensive screening tool for diverse medical encounters.
Paying Them to Hate US: The Effect of US Military Aid on Anti-American Terrorism, 1968–2018
Authors: Dimant Eugen , Krieger Tim , Meierrieks Daniel
Published: May 2024

How does anti-American terrorism in recipient countries respond to US military aid? Does aid protect United States interests abroad or does it have unintended consequences for US security? To answer these questions, we estimate the effect of US military aid on anti-American terrorism in recipient countries for a sample of 174 countries between 1968 and 2018. We find that higher levels of aid especially for military financing and education are associated with a higher likelihood of anti-American terrorism in aid-receiving countries. Examining potential transmission channels, we show that more US military aid correlates with lower military capacity and increases in corruption and exclusionary policies in recipient countries. Our findings are consistent with the argument that military aid aggravates local grievances, creating anti-American resentment and leading to anti-American terrorism. Indeed, we also provide tentative evidence that US military aid is associated with lower public opinion about the United States in recipient countries.
Differences in the body image based on physical parameters among young women from the Czech Republic and Slovakia
Authors: Babosová Ramona , Matejovičová Barbora , Langraf Vladimír , Kopecký Miroslav , Sandanusová Anna , Petrovičová Kornélia , Schlarmannová Janka
Published: May 2024

Background

The increased prevalence of overweight and obesity in the Czech Republic and Slovakia has led to heightened emphasis on weight control, particularly among women. Our aim is to explore body image perceptions among women in both countries and compare their attitudes, focusing on the relationship between body image and body mass index (BMI), height, weight, body fat and the weight control.

Methods

The cross-sectional study involved 358 female students from the University of Pardubice and Constantine the Philosopher University in Nitra, with equal representation from the Czech Republic and Slovakia. Body parameters were assessed using anthropometric methods and the InBody 230 diagnostic device, while participants’ perceptions of their bodies were evaluated using the Body Shape Questionnaire.

Results

The results confirmed that BMI did not significantly influence self-perception among Slovak students, while Czech participants with increasing obesity tended to perceive themselves more negatively. Significantly higher median values for BMI (p = 0.0509), weight (p = 0.0507), height (p = 0.05) and body image (p = 0.002) were observed in the Czech Republic compared with Slovakia. No significant difference was found in weight control and fat between participants from both countries.

Conclusions

Although obesity was demonstrated in both nations, body satisfaction was different for participants from the Czech Republic and Slovakia.
Imprints of ecological processes in the taxonomic core community: an analysis of naturally replicated microbial communities enclosed in oil
Authors: Brauer Verena S , Voskuhl Lisa , Mohammadian Sadjad , Pannekens Mark , Haque Shirin , Meckenstock Rainer U
Published: May 2024

It is widely assumed that a taxonomic core community emerges among microbial communities from similar habitats because similar environments select for the same taxa bearing the same traits. Yet, a core community itself is no indicator of selection because it may also arise from dispersal and neutral drift, i.e. by chance. Here, we hypothesize that a core community produced by either selection or chance processes should be distinguishable. While dispersal and drift should produce core communities with similar relative taxon abundances, especially when the proportional core community, i.e. the sum of the relative abundances of the core taxa, is large, selection may produce variable relative abundances. We analyzed the core community of 16S rRNA gene sequences of 193 microbial communities occurring in tiny water droplets enclosed in heavy oil from the Pitch Lake, Trinidad and Tobago. These communities revealed highly variable relative abundances along with a large proportional core community (68.0 ± 19.9%). A dispersal-drift null model predicted a negative relationship of proportional core community and compositional variability along a range of dispersal probabilities and was largely inconsistent with the observed data, suggesting a major role of selection for shaping the water droplet communities in the Pitch Lake.
Determinants of bacterial survival and proliferation in blood
Authors: Lê-Bury Pierre , Echenique-Rivera Hebert , Pizarro-Cerdá Javier , Dussurget Olivier
Published: May 2024

Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
Direct Parental (DIPA) CRISPR in the jewel wasp, Nasonia vitripennis
Authors: Zhang Xinmi , Singh Anabhra , Soriano Martinez Kassandra , Ferree Patrick M
Published: May 2024

While clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 technology has demonstrated remarkable promise as a gene-editing tool, its application in certain insects, such as the jewel wasp, Nasonia vitripennis, has been hindered by a lack of a tractable method for reagent delivery. Direct Parental (DIPA-) CRISPR recently emerged as a facile way to induce gene lesions because it involves adult injection with commercially available Cas9–sgRNA with no helper reagent. However, DIPA-CRISPR has so far been tested in only a few insects. Here, we have assessed the amenability of DIPA-CRISPR in N. vitripennis by targeting two eye pigmentation genes, cinnabar and vermilion, which function in the ommochrome pathway. Successful generation of lesions in both genes demonstrated the functionality of DIPA-CRISPR in N. vitripennis and its potential application to other genes, thereby expanding the range of insects suitable for this method. We varied two parameters, Cas9–sgRNA concentration and injection volume, to determine optimal injection conditions. We found that the larger injection volume coupled with either higher or lower reagent concentration was needed for consistent mutation production. However, DIPA-CRISPR yields an overall low mutation rate in N. vitripennis when compared to other tested insects, a characteristic that may be attributed to a proportionally low vitellogenic import efficiency in the jewel wasp. We discuss different factors that may be considered in determining when DIPA-CRISPR may be preferable over other reagent delivery methods.
Childhood Adversities and Caregiving for Older Parents: Building Capacity for a Caring Society
Authors: Hu Bo , Bai Xue , Wang Pengyun
Published: May 2024

Objectives

This study investigates the relationships between childhood adversities and the provision of informal care for older parents in later life in China.

Methods

The data came from 4 waves of the China Health and Retirement Longitudinal Study (N = 20,047). Using multilevel logistic regression models, we examined the relationships between adverse experiences in childhood and both the propensity and intensity of caregiving for older parents. Drawing on the regression results, we then estimated the total number of caregivers for older parents in China.

Results

Experiencing 1 additional childhood adversity was associated with a decrease of 8% in the odds of providing informal care (p < .001). The association between childhood adversity and caregiving remained significant after sociodemographic factors and later-life outcomes were controlled for. We estimated that 58.3 million middle-aged adults in China were providing care for parents in 2020. Had people experienced 1 fewer adversity in their childhood, there would have been 2.2 million more caregivers in 2020. Had they experienced 2 fewer adversities, there would have been 3.4 million more caregivers.

Discussion

The factors associated with informal caregiving can be traced back to early-life experiences. To address the shortage of informal care supply, it is crucial to foster a caring culture from the very beginning of human development.
Locating clustered seismicity using Distance Geometry Solvers: applications for sparse and single-borehole DAS networks
Authors: Tuinstra Katinka , Grigoli Francesco , Lanza Federica , Rinaldi Antonio Pio , Fichtner Andreas , Wiemer Stefan
Published: May 2024

The determination of seismic event locations with sparse networks or single-borehole systems remains a significant challenge in observational seismology. Leveraging the advantages of the location approach HADES (eartHquake locAtion via Distance gEometry Solvers), which was initially developed for locating clustered seismicity recorded at two stations, through the solution of a Distance Geometry Problem, we present here an improved version of the methodology: HADES-R (HADES-Relative). Where HADES previously needed a minimum of four absolutely located master events, HADES-R solves a least-squares problem to find the relative inter-event distances in the cluster, and uses only a single master event to find the locations of all events and subsequently applies rotational optimizer to find the cluster orientation. It can leverage iterative station combinations if multiple receivers are available, to describe the cluster shape and orientation uncertainty with a bootstrap approach. The improved method requires P- and S-phase arrival picks, a homogeneous velocity model, a single master event with a known location, and an estimate of the cluster width. The approach is benchmarked on the 2019 Ridgecrest sequence recorded at two stations, and applied to two seismic clusters at the FORGE geothermal test site in Utah, USA, with a microseismic monitoring scenario with a Distributed Acoustic Sensing in a vertical borehole. Traditional procedures struggle in these settings due to the ill-posed network configuration. The azimuthal ambiguity in such a scenario is partially overcome by the assumption that all events belong to the same cluster around the master event and a cluster width estimate. We are able to find the cluster shape in both cases, although the orientation remains uncertain. HADES-R contributes to an efficient way to locate multiple events simultaneously with minimal prior information. The method’s ability to constrain the cluster shape and location with only one well-located event offers promising implications, especially for environments where limited or specialized instrumentation is in use.
Resolution enhancement for a seismic velocity model using machine learning
Authors: Kim Sujeong , Cho Yongchae , Jun Hyunggu
Published: May 2024

To address complex subsurface structures, a high-resolution velocity model must be constructed. Conventionally, algorithms such as full waveform inversion (FWI) have been used to derive accurate high-resolution velocity structures, but obstacles such as high computational costs remain. Therefore, we propose a high-resolution U-NET (HR U-NET) machine learning model to derive a high-resolution velocity model from a low-resolution velocity model. The low-resolution velocity model and migration data obtained through the corresponding velocity information were used as input data for training. In addition, we tried to improve the accuracy of the high-resolution velocity model by using prior information containing accurate velocity values. A prior model generated through geophysical logging data and a weight model including the reliability information of the prior model were also utilized. Therefore, the HR U-NET model was trained using the low-resolution velocity model, the migration data, the prior model and the weight model. Numerical experiments conducted using synthetic and field data demonstrated that the proposed model could accurately construct a high-resolution velocity model and verified that the prior model and weight model play important roles in the training process. Additionally, we confirmed that the proposed method derived almost similar results using only 8.2 percent of the computational cost of the conventional inversion method. In other words, there is an advantage that it is possible to predict high-resolution velocity information more efficiently in terms of computational cost.
Efficient function approximation in enriched approximation spaces
Authors: Herremans Astrid , Huybrechs Daan
Published: May 2024

An enriched approximation space is the span of a conventional basis with a few extra functions included, for example to capture known features of the solution to a computational problem. Adding functions to a basis makes it overcomplete and, consequently, the corresponding discretized approximation problem may require solving an ill-conditioned system. Recent research indicates that these systems can still provide highly accurate numerical approximations under reasonable conditions. In this paper we propose an efficient algorithm to compute such approximations. It is based on the AZ algorithm for overcomplete sets and frames, which simplifies in the case of an enriched basis. In addition, analysis of the original AZ algorithm and of the proposed variant gives constructive insights on how to achieve optimal and stable discretizations using enriched bases. We apply the algorithm to examples of enriched approximation spaces in literature, including a few nonstandard approximation problems and an enriched spectral method for a 2D boundary value problem, and show that the simplified AZ algorithm is indeed stable, accurate and efficient.
Formation of the calpain-1/calpastatin complex promotes activation of calpain-1 under oxidizing conditions
Authors: Maddock Carlin Kasey R , Steadham Edward , Huff-Lonergan Elisabeth , Lonergan Steven M
Published: May 2024

Calpains are cysteine proteinases responsible for many biological roles in muscle, including protein degradation, muscle growth, and myoblast fusion. Calpains are inhibited by calpastatin, an endogenous inhibitor. Other factors, such as variations in pH, ionic strength, and oxidation influence calpain activity. This study aimed to determine the extent to which oxidation influences calpastatin inhibition of calpain-1. A series of order of addition assays were used to determine calpain-1 calcium activation and autolysis after exposure to an oxidizing agent (n-ethylmaleimide [NEM] or hydrogen peroxide [H2O2]. In the first series, purified calpastatin was added to the assay before or after oxidizing exposure at 165 mM NaCl, pH 6.5. In the second series, incubation buffer ionic strength (165 mM or 295 mM NaCl) was evaluated. The inhibitory activities of purified porcine calpastatin, purified human calpastatin domain I, or a subdomain B inhibitor peptide were evaluated in the third series. In the fourth series, a maleimide-polyethylene glycol molecule (MAL-PEG; MW = 5,000 Dalton) was used to evaluate the accessibility of free sulfhydryl groups and tagging of calpain-1 under each condition through a molecular weight shift assay. Results from this study indicate that autolysis of calpain-1, when used as an indicator of activation, occurred when the calpain-1/calpastatin complex was exposed to an oxidant or cysteine modifier such as NEM. However, when calpain-1 was exposed to the cysteine modifier before calpastatin, autolysis of calpain-1 did not occur or was significantly decreased (P < 0.05). Irreversible modification of cysteine residues by NEM prevented activation of calpain-1 in the absence of calpastatin, but if the cysteine modification is potentially reversible (H2O2), calpain-1 activity can be recovered. Results from this study indicate that when calpastatin is bound to calpain-1, calpain-1 activation can occur even after being exposed to a cysteine modifier (NEM) or hydrogen peroxide (H2O2). Calpain-1 is not tagged with maleimide-polyethylene glycol (MAL-PEG) in the presence of calpastatin, indicating that calpastatin blocks or covers free cysteines on calpain-1 from modification. Moreover, exposure to calpain-1/calpastatin complex with a cysteine modifier allows activation of calpain-1, indicating that the inhibitory action of calpastatin is compromised. These results indicate a regulatory role for calpastatin that is not inhibitory but protective for calpain-1.
Additive manufacturing-driven simultaneous optimization of topology and print direction for thermoelastic structures considering strength failure
Authors: Jiang Hexin , He Zhicheng , Li Eric , Jiang Chao
Published: May 2024

This paper presents a strength-based simultaneous optimization method for optimizing thermoelastic structural topology and print direction in the presence of anisotropy induced by additive manufacturing. The approach utilizes the bi-directional evolutionary structural optimization framework and defines design variables including element density and print-off angle. Firstly, an anisotropic thermoelastic constitutive model is established for finite element analysis. By introducing the Tsai–Hill failure criteria, the strength constraint to evaluate the stress level of additively manufactured anisotropic components is formulated. The P-norm aggregation function is employed to approximate the maximum strength failure coefficient. Then, the aggregated strength constraint is augmented to the optimization objective through a Lagrange multiplier. Sensitivity analysis of the new objective function with respect to the elemental design variables is performed, and an analytical approach is proposed to optimize the print-off angle. To improve the stability of the optimization procedure, a series of numerical algorithms and parameter updating strategies are developed. The effectiveness of our proposed method is demonstrated through typical numerical examples, highlighting a desirable match between the structural topology and the print direction can greatly improve the structural performance.
“A Conscience Rightly Informed”: Puritan Casuistry and the Theological Justifications for Religious Establishment
Authors: Higdon Cory D
Published: May 2024

In the early modern debates over religious liberty and toleration, religious dissenters often raised the issue of an individual’s conscience as a primary support for disestablishment. Dissenters like Roger Williams contended that establishmentarian policies persecuted tender consciences. God, according to dissenters, had not granted authority over the conscience to civil rulers; thus, religious establishment was both theologically specious as well as politically perilous. Much attention has been given to how religious dissenters discussed the human conscience and its place within the civil society. This essay, however, focuses on how magisterial Protestants developed their theological system of religious establishment in concert with their own understanding of the human conscience. Proponents of establishment utilized their own theology of the conscience as grounds for religious establishment, and this essay seeks to understand how they reconciled their soteriological convictions and their conception of the human conscience with their belief in the magistrate’s authority in matters of doctrine and religion.
Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics
Authors: Ma Yina , Zhao Yu , Zhang Xin
Published: May 2024

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils’ functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis.
Using forced migration to foster emergence? International aid and development policies in Cameroon
Authors: Lefort-Rieu Claire
Published: May 2024

This paper examines the alignment of refugee aid interventions with Cameroon’s national policy of emergence, shedding light on an authoritarian government's utilization of international assistance. Drawing on extensive ethnographic fieldwork, it investigates how international policies aiming at turning refugees into a development opportunity for their host states are managed by an aid-receiving country and strategically leveraged by Cameroonian authorities to strengthen their political apparatus. It explores how the government integrates humanitarian responses with large-scale development policies, while retaining control over strategic sectors. Implementing the emergence policy enables Cameroon to reappropriate international standards, navigating complex donor relations to establish new legitimacy. The analysis highlights the power dynamics and implications of aid interventions within an authoritarian context, demonstrating the state's capacity to transform internal crises into productive forces. This research contributes to a better understanding of the links between refugee aid, host states’ domestic and international politics, and migration diplomacy.
Disciplining subjectivity in Australian migrant deterrence campaigns
Authors: Zeweri Helena
Published: May 2024

This article examines public information campaigns designed to deter asylum seekers from entering Australia via boat. Through analysing the institutional context and content of a graphic novel that was circulated within Afghan Hazara communities in 2014, I show that certain Australian public information campaigns mobilize an ethos of cultural sensitivity rooted in ethnographic data-gathering projects that reinscribe migrants as ignorant and socially deviant subjects. Such campaigns both situate Australia as an impossible destination and render migration a dangerous, futile act that will bring further misfortune to migrants’ families. The Australian case shows that in contexts where cultural sensitivity and externalized border control simultaneously guide migration policy, cultural knowledge becomes weaponized not only to keep migrants immobile but also to discipline migrant subjectivity and ultimately exclude them from pathways to refuge.
Beyond victim and hero representations? A comparative analysis of UNHCR’s Instagram communication strategies for the Syrian and Ukrainian crises
Authors: Ongenaert David , Soler Claudia
Published: May 2024

The Ukrainian crisis has received substantial Global Northern policy support and favourable news coverage, contrasting sharply with Global Southern crises. Nevertheless, refugee organizations can influence public perceptions through social media. This study comparatively analyses UNHCR’s Instagram communication strategies for the Ukrainian and Syrian crises (2022–2023). Applying a multimodal critical discourse analysis on UNHCR’s Instagram posts (N = 90), we discern interacting humanitarian and post-humanitarian appeals, involving inter- and intra-group hierarchies of deservingness, expanding research on humanitarian communication. While UNHCR mainly represents forcibly displaced Ukrainians as victims and focuses on ‘ideal victims’, it mostly portrays forcibly displaced Syrians as empowered individuals, likely due to context-specific differences and partially countering news and policy narratives. Both humanitarian representations often intersect with post-humanitarian strategies, facilitated by Instagram affordances. This study thus contributes to the literature on humanitarian communication with comparative crisis-specific and platform-specific insights and causes. Moreover, it nuances the often-assumed importance of post-humanitarian imageries on social media.
On the rise and fall of galactic ionizing output at the end of reionization
Authors: Cain Christopher , D’Aloisio Anson , Lopez Garett , Gangolli Nakul , Roth Joshua T
Published: May 2024

Quasar absorption spectra measurements suggest that reionization proceeded rapidly, ended late at z ∼ 5.5, and was followed by a flat ionizing background evolution. Simulations that reproduce this behaviour often rely on a fine-tuned galaxy ionizing emissivity, which peaks at z ∼ 6–7 and drops a factor of 1.5–2.5 by z ∼ 5. This is puzzling since the abundance of galaxies is observed to grow monotonically during this period. Explanations for this include effects such as dust obscuration of ionizing photon escape and feedback from photoheating of the IGM. We explore the possibility that this drop in emissivity is instead an artefact of one or more modelling deficiencies in reionization simulations. These include possibly incorrect assumptions about the ionizing spectrum and/or inaccurate modelling of IGM clumping. Our results suggest that the need for a drop could be alleviated if simulations are underestimating the IGM opacity from massive, star-forming haloes. Other potential modelling issues either have a small effect or require a steeper drop when remedied. We construct an illustrative model in which the emissivity is nearly flat at reionization’s end, evolving only ∼0.05 dex at 5 < z < 7. More realistic scenarios, however, require a ∼0.1–0.3 dex drop. We also study the evolution of the Ly α effective optical depth distribution and compare to recent measurements. We find that models that feature a hard ionizing spectrum and/or are driven by faint, low-bias sources most easily reproduce the mean transmission and optical depth distribution of the forest simultaneously.
The structure and evolution of relativistic jetted blast waves
Authors: Govreen-Segal Taya , Nakar Ehud
Published: May 2024

We study, analytically and numerically, the structure and evolution of relativistic jetted blast waves that propagate in uniform media, such as those that generate afterglows of gamma-ray bursts. Similar to previous studies, we find that the evolution can be divided into two parts: (i) a pre-spreading phase, in which the jet core angle is roughly constant, θc,0, and the shock Lorentz factor along the axis, Γa, evolves as a part of the Blandford–Mckee solution, and (ii) a spreading phase, in which Γa drops exponentially with the radius and the core angle, θc, grows rapidly. Nevertheless, the jet remains collimated during the relativistic phase, where $\theta _\mathrm{ c}(\Gamma _\mathrm{ a}\beta _\mathrm{ a}=1)\simeq 0.4\theta _{\mathrm{ c},0}^{1/3}$. The transition between the phases occurs when $\Gamma _\mathrm{ a}\simeq 0.2\theta _{\mathrm{ c},0}^{-1}$. We find that the “wings” of jets with initial “narrow” structure ($\frac{\mathrm{ d} \log \, E_{\mathrm{ iso}}}{\mathrm{ d}\log \, \theta }\lt -3$ outside of the core, where Eiso is isotropic equivalent energy), start evolving during the pre-spreading phase. By the spreading phase these jets evolve to a self-similar profile, which is independent of the initial structure, where in the wings Γ(θ)∝θ−1.5 and Eiso(θ)∝θ−2.6. Jets with initial “wide” structure roughly keep their initial profile during their entire evolution. We provide analytic description of the jet lateral profile evolution for a range of initial structures, as well as the evolution of Γa and θc. For off-axis GRBs, we present a relation between the initial jet structure and the light curve rising phase. Applying our model to GW170817, we find that initially the jet had $\theta _{\mathrm{ c},0}=0.4-4.5~\deg$ and wings consistent with Eiso∝θ−3 − θ−4.
Mid-infrared echoes of ambiguous nuclear transients reveal high dust covering fractions: evidence for dusty tori
Authors: Hinkle Jason T
Published: May 2024

Alongside the recent increase in discoveries of tidal disruption events (TDEs) have come an increasing number of ambiguous nuclear transients (ANTs). These ANTs are characterized by hot blackbody-like UV/optical spectral energy distributions (SEDs) and smooth photometric evolution, often with hard power law-like X-ray emission. ANTs are likely exotic TDEs or smooth flares originating in active galactic nuclei (AGNs). While their emission in the UV/optical and X-ray has been relatively well-explored, their infrared (IR) emission has not been studied in detail. Here, we use the NEOWISE mission and its low-cadence mapping of the entire sky to study mid-IR dust reprocessing echoes of ANTs. We study 19 ANTs, finding significant MIR flares in 18 objects for which we can estimate an IR luminosity and temperature evolution. The dust reprocessing echoes show a wide range in IR luminosities (∼1042–1045 erg s−1) with blackbody temperatures largely consistent with sublimation temperature of graphite grains. Excluding the two sources possibly associated with luminous supernovae (ASASSN-15lh and ASASSN-17jz), the dust covering fractions (fc) for detected IR flares lie between 0.05 and 0.91, with a mean of fc = 0.29 for all ANTs (including limits) and fc = 0.38 ± 0.04 for detections. These covering fractions are much higher than optically selected TDEs and similar to AGNs. We interpret the high covering fractions in ANT host galaxies as evidence for the presence of a dusty torus.
Exoplanet transit spectroscopy with JWST NIRSpec: diagnostics and homogeneous case study of WASP-39 b
Authors: Sarkar Subhajit , Madhusudhan Nikku , Constantinou Savvas , Holmberg Måns
Published: May 2024

The JWST has ushered in a new era of exoplanet transit spectroscopy. Among the JWST instruments, the Near-Infrared Spectrograph (NIRSpec) has the most extensive set of configurations for exoplanet time-series observations. The NIRSpec Prism and G395H grating represent two extremes in NIRSpec instrument modes, with the Prism spanning a wider spectral range (0.6–5.3 µm) at lower resolution (R ∼ 100) compared to G395H (2.87–5.14 µm; R ∼ 2700). In this work, we develop a new data reduction framework, JexoPipe, to conduct a homogeneous assessment of the two NIRSpec modes for exoplanet spectroscopy. We use observations of the hot Saturn WASP-39 b obtained as part of the JWST Transiting Exoplanet Early Release Science programme to assess the spectral quality and stability between the two instrument modes at different epochs. We explore the noise sources, effect of saturation, and offsets in transmission spectra between the different instrument modes and also between the two G395H NRS detectors. We find an inter-detector offset in G395H of ∼40–50 ppm, consistent with recent studies. We find evidence for correlated noise in the Prism white light curve. We find the G395H spectrum to be of higher precision compared to the Prism spectrum at the same resolution. We also compare the JexoPipe spectra with those reported from other pipelines. Our work underscores the need for robust assessment of instrument performance and identification of optimal practices for JWST data reduction and analyses.
Kinematic substructure in star clusters constrains star cluster formation
Authors: Arnold Becky , Wright Nicholas J
Published: May 2024

The spatial–kinematic structure of 48 young star clusters and associations is investigated. Moran’s I statistic is used to quantify the degree of kinematic substructure in each region, and the results are compared to those expected assuming the hierarchical or monolithic models of star cluster formation. Of the observed regions, 39 are found to have significant kinematic substructure, such that they are compatible with the hierarchical model and incompatible with the monolithic model. This includes multiple regions whose Q parameter shows the region to be centrally concentrated and clustered. The remaining nine are compatible with both models. From this, it is concluded that the kinematic substructure of the observed star clusters represents strong evidence in favour of the hierarchical model of star cluster formation over the monolithic model.
An asymptotically correct implicit–explicit time integration scheme for finite volume radiation-hydrodynamics
Authors: He Chong-Chong , Wibking Benjamin D , Krumholz Mark R
Published: May 2024

Numerical radiation-hydrodynamics (RHD) for non-relativistic flows is a challenging problem because it encompasses processes acting over a very broad range of time-scales, and where the relative importance of these processes often varies by orders of magnitude across the computational domain. Here, we present a new implicit–explicit method for numerical RHD that has a number of desirable properties that have not previously been combined in a single method. Our scheme is based on moments and allows machine-precision conservation of energy and momentum, making it highly suitable for adaptive mesh refinement applications; it requires no more communication than hydrodynamics and includes no non-local iterative steps, making it highly suitable for massively parallel and Graphics Processing Unit (GPU)-based systems where communication is a bottleneck; and we show that it is asymptotically accurate in the streaming, static diffusion, and dynamic diffusion limits, including in the so-called asymptotic diffusion regime where the computational grid does not resolve the photon mean-free path. We implement our method in the GPU-accelerated RHD code quokka and show that it passes a wide range of numerical tests.
Randomness and retention: using weak mean motion resonances to constrain Neptune’s late-stage migration
Authors: Hermosillo Ruiz Arcelia , Lau Harriet C P , Murray-Clay Ruth
Published: May 2024

Planet–planetesimal interactions cause a planet to migrate, manifesting as a random walk in semimajor axis. In models for Neptune’s migration involving a gravitational upheaval, this planetesimal-driven migration is a side-effect of the dynamical friction required to damp Neptune’s orbital eccentricity. This migration is noisy, potentially causing Trans-Neptunian Objects (TNOs) in mean motion resonance to be lost. With N-body simulations, we validate a previously derived analytic model for resonance retention and determine unknown coefficients. We identify the impact of random-walk (noisy) migration on resonance retention for resonances up to fourth order lying between 39  and 75 au. Using a population estimate for the weak 7:3 resonance from the well-characterized Outer Solar System Origins Survey (OSSOS), we rule out two cases: (1) a planetesimal disc distributed between 13.3 and 39.9 au with ≳ 30 Earth masses in today’s size distribution and Tmig ≳ 40 Myr and (2) a top-heavy size distribution with ≳2000 Pluto-sized TNOs and Tmig ≳10 Myr, where Tmig is Neptune’s migration time-scale. We find that low-eccentricity TNOs in the heavily populated 5:2 resonance are easily lost due to noisy migration. Improved observations of the low-eccentricity region of the 5:2 resonance and of weak mean motion resonances with Rubin Observatory’s Legacy Survey of Space and Time will provide better population estimates, allowing for comparison with our model’s retention fractions and providing strong evidence for or against Neptune’s random interactions with planetesimals.
Cosmic dipoles of active galactic nuclei at optical and radio wavelengths display much larger amplitudes than the cosmic microwave background dipole
Authors: Singal Ashok K
Published: May 2024

Sky distributions of large samples of distant active galactic nuclei (AGNs) have shown dipoles significantly larger than the cosmic microwave background (CMB) dipole. However, a recent Bayesian analysis of the Quaia sample, comprising 1.3 million quasars, has yielded a dipole that seems to be in tandem with the CMB dipole, in contravention of most previous studies of AGN dipoles. Since the question has large cosmological implications, we investigate the Quaia quasar sample afresh, by directly computing the dipole from asymmetries observed in the source number counts. We instead find a dipole 3-4 times as large as the CMB dipole though in the same direction. Further, it has been claimed elsewhere that the difference between the CMB dipole and the radio dipole estimated from the NRAO VLA Sky Survey (NVSS), the first large catalogue that showed an AGN dipole about four times larger than the CMB dipole, can be fully accounted for by incorporating the shot noise and clustering contributions to the total NVSS dipole. A careful reinvestigation of the NVSS dipole, however, shows that the random phenomena like shot noise or clustering cannot account for the actually observed NVSS asymmetries, which show a systematic dipole pattern over the sky.
Advancements in prokaryotic systematics and the role of Bergey's International Society for Microbial Systematicsin addressing challenges in the meta-data era
Authors: Jiao Jian-Yu , Abdugheni Rashidin , Zhang Dao-Feng , Ahmed Iftikhar , Ali Mukhtiar , Chuvochina Maria , Dedysh Svetlana N , Dong Xiuzhu , Göker Markus , Hedlund Brian P , Hugenholtz Philip , Jangid Kamlesh , Liu Shuang-Jiang , Moore Edward R B , Narsing Rao Manik Prabhu , Oren Aharon , Rossello-Mora Ramon , Rekadwad Bhagwan Narayan , Salam Nimaichand , Shu Wensheng , Sutcliffe Iain C , Teo Wee Fei Aaron , Trujillo Martha E , Venter Stephanus N , Whitman William B , Zhao Guoping , Li Wen-Jun
Published: May 2024

Prokaryotes are ubiquitous in the biosphere, important for human health and drive diverse biological and environmental processes. Systematics of prokaryotes, whose origins can be traced to the discovery of microorganisms in the 17th century, has transitioned from a phenotype-based classification to a more comprehensive polyphasic taxonomy and eventually to the current genome-based taxonomic approach. This transition aligns with a foundational shift from studies focused on phenotypic traits that have limited comparative value to those using genome sequences. In this context, Bergey's Manual of Systematics of Archaea and Bacteria (BMSAB) and Bergey's International Society for Microbial Systematics (BISMiS) play a pivotal role in guiding prokaryotic systematics. This review focuses on the historical development of prokaryotic systematics with a focus on the roles of BMSAB and BISMiS. We also explore significant contributions and achievements by microbiologists, highlight the latest progress in the field and anticipate challenges and opportunities within prokaryotic systematics. Additionally, we outline five focal points of BISMiS that are aimed at addressing these challenges. In conclusion, our collaborative effort seeks to enhance ongoing advancements in prokaryotic systematics, ensuring its continued relevance and innovative characters in the contemporary landscape of genomics and bioinformatics.
The SK4 channel allosteric blocker, BA6b9, reduces atrial fibrillation substrate in rats with reduced ejection fraction
Authors: Burg Shira , Levi Or , Elyagon Sigal , Shapiro Shir , Murninkas Michael , Etzion Sharon , Gradwohl Gideon , Makarovsky Daria , Lichtenstein Alexandra , Gordon Yaara , Attali Bernard , Etzion Yoram
Published: May 2024

Atrial fibrillation (AF), the most common cardiac arrhythmia, is strongly associated with several comorbidities including heart failure (HF). AF in general, and specifically in the context of HF, is progressive in nature and associated with poor clinical outcomes. Current therapies for AF are limited in number and efficacy and do not target the underlying causes of atrial remodeling such as inflammation or fibrosis. We previously identified the calcium-activated SK4 K+ channels, which are preferentially expressed in the atria relative to the ventricles in both rat and human hearts, as attractive druggable target for AF treatment. Here, we examined the ability of BA6b9, a novel allosteric inhibitor of SK4 channels that targets the specific calmodulin-PIP2 binding domain, to alter AF susceptibility and atrial remodeling in a systolic HF rat postmyocardial infarction (post-MI) model. Daily BA6b9 injection (20 mg/kg/day) for 3 weeks starting 1-week post-MI prolonged the atrial effective refractory period, reduced AF induction and duration, and dramatically prevented atrial structural remodeling. In the post-MI left atrium (LA), pronounced upregulation of the SK4 K+ channel was observed, with corresponding increases in collagen deposition, α-SMA levels, and NLRP3 inflammasome expression. Strikingly, BA6b9 treatment reversed these changes while also significantly reducing the lateralization of the atrial connexin Cx43 in the LA of post-MI rats. Our findings indicate that the blockade of SK4 K+ channels using BA6b9 not only favors rhythm control but also remarkably reduces atrial structural remodeling, a property that is highly desirable for novel AF therapies, particularly in patients with comorbid HF.