bluuebunny/crossref_metadata_2025 huggingface dataset:
Dermatoscopic profiling of inverted follicular keratosis in different skin phenotypes
Authors: Demirdağ Hatice Gamze , Akay Bengü Nisa
Published: January 2024

Background

Inverted follicular keratosis (IFK) is a rare benign tumour of the follicular infundibulum. Owing to its similarity to other benign and malignant cutaneous lesions, it poses a diagnostic challenge. There is limited information on the dermatoscopic characteristics of IFK and the majority of cases have been reported in patients with lighter skin types.

Objectives

To describe the prevalent dermatoscopic features of IFK, especially in patients with skin of colour.

Methods

We retrospectively analysed 35 histopathologically verified cases of IFK from a single university hospital in Turkey.

Results

With respect to the Fitzpatrick skin phototype, 2 (6%), 12 (34%), 16 (46%) and 5 (14%) patients had Fitzpatrick skin phototypes II, III, IV and V, respectively. Clinically, the majority of IFKs were hypopigmented or nonpigmented (83%). Pink–white structureless areas (54%), ulceration (54%), a central keratin mass (43%) and blood spots on keratin mass (43%) were the most frequent dermatoscopic findings. Pigmented structures were observed as blue–grey structureless areas in 12 lesions and as blue–grey clods in 5, primarily in Fitzpatrick phototype IV and V skin. The incidence of a pink, structureless area and blood spots on ulceration was found to be statistically significantly higher in individuals with fairer skin types, while a greater prevalence of blue–grey coloration was observed in those with skin of colour (P < 0.05).

Conclusions

Although our study found some distinguishing dermatoscopic findings in IFK, diagnosis is generally confirmed by histopathology, as the clinical appearance and dermatoscopic findings may not be sufficient to differentiate it from other tumours, especially squamous cell carcinoma or keratoacanthoma. The dermatoscopic characteristics of dark skin are comparable to those of pale skin; however, hyperpigmentation can be more noticeable in skin of colour.
Patient and Caregiver Perspectives on Their Experiences With Crohn’s Perianal Fistulas
Authors: Stacy Sylvie , Belcher Emily , Nazarey Pradeep P , Cazzetta Susan E , Salinas Gregory D
Published: January 2024

Background

Little is known about patients’ perception of care and management of Crohn’s perianal fistulas (CPF). This study was conducted to understand US patient and caregiver attitudes and challenges to CPF care.

Methods

Patients with CPF and caregivers of patients with CPF completed a 36-question survey about their perceptions and challenges regarding the diagnosis, treatment, and overall management of CPF. Patients/caregivers were recruited via online Crohn’s and fistula support group websites and forums and via their gastroenterologists (GEs) and surgeons from October 2020 through January 2021.

Results

The survey was completed by 96 patients and 54 caregivers. Respondents reported over 60% and 14%–23% of CPF were diagnosed and treated by a GE or surgeon, respectively. Nearly all patients/caregivers wanted to be involved in treatment decision-making with their physicians (81%). While the majority of patients/caregivers were satisfied with their quality of care (65%) and access to care (67%), racial disparities exist and there is room for improvement. A smaller proportion of non-White versus White patients/caregivers reported satisfaction with care quality (39% vs 72%, respectively) and access to care (57% vs 69%, respectively). Half of non-White patient/caregivers (50%) versus 69% of White patient/caregivers knew where to access CPF information. Most patients/caregivers (69%) stated that they would benefit from more information on managing day-to-day CPF symptoms. Significant barriers perceived by patients/caregivers to receiving optimal CPF care included lack of effective treatments (69%) and lack of access to specialist care (68%).

Conclusions

Improvements in multidisciplinary CPF care are required to optimize treatment.
The role of cellular senescence in profibrillatory atrial remodelling associated with cardiac pathology
Authors: Mehdizadeh Mozhdeh , Naud Patrice , Abu-Taha Issam H , Hiram Roddy , Xiong Feng , Xiao Jiening , Saljic Arnela , Kamler Markus , Vuong-Robillard Nhung , Thorin Eric , Ferbeyre Gerardo , Tardif Jean-Claude , Sirois Martin G , Tanguay Jean Francois , Dobrev Dobromir , Nattel Stanley
Published: January 2024

Aims

Cellular senescence is a stress-related or aging response believed to contribute to many cardiac conditions; however, its role in atrial fibrillation (AF) is unknown. Age is the single most important determinant of the risk of AF. The present study was designed to (i) evaluate AF susceptibility and senescence marker expression in rat models of aging and myocardial infarction (MI), (ii) study the effect of reducing senescent-cell burden with senolytic therapy on the atrial substrate in MI rats, and (iii) assess senescence markers in human atrial tissue as a function of age and the presence of AF.

Methods and results

AF susceptibility was studied with programmed electrical stimulation. Gene and protein expression was evaluated by immunoblot or immunofluorescence (protein) and digital polymerase chain reaction (PCR) or reverse transcriptase quantitative PCR (messenger RNA). A previously validated senolytic combination, dasatinib and quercetin, (D+Q; or corresponding vehicle) was administered from the time of sham or MI surgery through 28 days later. Experiments were performed blinded to treatment assignment. Burst pacing-induced AF was seen in 100% of aged (18-month old) rats, 87.5% of young MI rats, and 10% of young control (3-month old) rats (P ≤ 0.001 vs. each). Conduction velocity was slower in aged [both left atrium (LA) and right atrium (RA)] and young MI (LA) rats vs. young control rats (P ≤ 0.001 vs. each). Atrial fibrosis was greater in aged (LA and RA) and young MI (LA) vs. young control rats (P < 0.05 for each). Senolytic therapy reduced AF inducibility in MI rats (from 8/9 rats, 89% in MI vehicle, to 0/9 rats, 0% in MI D + Q, P < 0.001) and attenuated LA fibrosis. Double staining suggested that D + Q acts by clearing senescent myofibroblasts and endothelial cells. In human atria, senescence markers were upregulated in older (≥70 years) and long-standing AF patients vs. individuals ≤60 and sinus rhythm controls, respectively.

Conclusion

Our results point to a potentially significant role of cellular senescence in AF pathophysiology. Modulating cell senescence might provide a basis for novel therapeutic approaches to AF.
A case series of the twiddler syndrome
Authors: Montisci Roberta , Soro Cinzia , Demelas Roberta , Agus Elena , Follesa Alessio , Siragusa Gesualdo , Nissardi Vincenzo
Published: January 2024

Background

Twiddler syndrome (TS) is a complication of cardiac implantable electronic device (CIED) implantation, caused by the deliberate or unconscious manipulation of the device by the patient himself, which results in dislocation of the leads by retraction towards the subcutaneous pocket.

Case summary

This report describes two clinical cases that occurred in our centre, for which two different solutions were successfully implemented. In the first case, a complete removal of the stimulation system was performed, and a leadless pacemaker (PM; Medtronic Micra VR) was implanted. In the second case, the patient underwent a revision procedure. The PM was disconnected, and the electrodes were debrided, a submuscular pocket for the PM was created, and at the end of the procedure, the PM was anchored to the pectoralis major.

Discussion

Twiddler syndrome is a not so rare and serious complication of CIED implantation, leading to device malfunctioning and higher risk of infection of the pocket due to multiple re-interventions. In these two cases, different surgical solutions were performed, both resulting to be effective to solve the effects of TS.
Electrophysiological characteristics and ablation of ventricular arrhythmias originating from the intramural basal inferior septum
Authors: Yang Jie , Li Mengmeng , Jiang Chenxi , Tang Ribo , Sang Caihua , Wang Wei , Zhao Xin , Li Changyi , Li Songnan , Guo Xueyuan , Jia Changqi , Ning Man , Feng Li , Wen Dan , Zhu Hui , Jiang Yuexin , Liu Tong , Liu Fang , Long Deyong , Dong Jianzeng , Ma Changsheng
Published: January 2024

Aims

The electrocardiographic and electrophysiological characteristics of ventricular arrhythmia (VA) arising from the intramural basal inferior septum (BIS) have not been specifically addressed to date. The aim of the current study was to characterize intramural BIS-VA and distinguish it from those with endocardial origins besides clarifying the anatomical configurations of the pyramidal space.

Methods and results

Fifty-five consecutive patients undergoing catheter ablation of VAs from BIS were identified and divided into three groups: the left ventricular (LV)-BIS group (n = 28), right ventricular (RV)-BIS group (n = 8), and intramural group (Intra, n = 19). Compared with the LV-BIS and RV-BIS groups, patients in the Intra group presented with no adequate earliest activation time at the two-sided BIS and epicardial coronary system [right: 7.79 ± 2.38 vs. left: 7.16 ± 2.59 vs. the middle cardiac vein (MCV): 6.26 ± 1.73 ms, P = 0.173] and poor-matched pacing-produced QRS at each site. Under the intracardiac echocardiography view, the pyramidal base was the broadest part of the septum and served as the division of the two-sided BIS. Focal ablation yielded promising acute-term and long-term procedural success in the LV-BIS and RV-BIS groups. But for the Intra group, VAs disappeared only after stepwise ablation successively targeted early preferential exit. After follow-up, three patients in the Intra group had recurrent VA, and all of them were treated well by a redo procedure or drug therapy.

Conclusion

Intramural VAs were relatively common in the BIS region in our series. Intra-procedural mapping was important to distinguish the intramural VAs from other VAs by comparing the local activation time and pacing mapping. Procedural success could be achieved by stepwise ablation on the counterpart sides of the BIS and within the MCV.
Collaborative exercise: analysis of age estimation using a QIAGEN protocol and the PyroMark Q48 platform
Authors: Kampmann Marie-Louise , Fleckhaus Jan , Børsting Claus , Jurtikova Helena , Piters Alice , Papin Julien , Gauthier Quentin , Ghemrawi Mirna , Doutremepuich Christian , McCord Bruce , Schneider Peter M , Drabek Jiri , Morling Niels
Published: January 2024

Human age estimation from trace samples may give important leads early in a police investigation by contributing to the description of the perpetrator. Several molecular biomarkers are available for the estimation of chronological age, and currently, DNA methylation patterns are the most promising. In this study, a QIAGEN age protocol for age estimation was tested by five forensic genetic laboratories. The assay comprised bisulfite treatment of the extracted DNA, amplification of five CpG loci (in the genes of ELOVL2, C1orf132, TRIM59, KLF14, and FHL2), and sequencing of the amplicons using the PyroMark Q48 platform. Blood samples from 49 individuals with ages ranging from 18 to 64 years as well as negative and methylation controls were analyzed. An existing age estimation model was applied to display a mean absolute deviation of 3.62 years within the reference data set.

Key points
Degenerate orthorhombic models
Authors: Stovas Alexey , Roganov Yuriy , Roganov Vyacheslav
Published: January 2024

We define the degenerate orthorhombic anisotropy models which have two symmetric singularity lines with constant phase velocity for S1 and S2 waves. Depending on the singularity line trajectory, we consider two types of degenerate models (VTI- and HTI-type). In addition to this singularity line, seriethere is always one isolated singularity point in one of non-essential symmetry planes. The degenerate orthorhombic model has seven independent parameters and can be parametrized by different combinations of the stiffness coefficients. Exploiting the fact that the second-order derivatives matrix computed from the Christoffel polynomial is degenerate, we also compute the group velocity image of this singularity line.
‘Double Puzzle’ at the Shumagin seismic gap, Alaska Peninsula: intraslab strike-slip faulting loaded by lateral variations in megathrust fault friction
Authors: Senapati Batakrushna , Lindsey Eric O , Kundu Bhaskar , Panda Dibyashakti , Tiwari Deepak K , Yadav Rajeev Kumar
Published: January 2024

Along the Aleutian megathrust, the Shumagin seismic gap (162° W–158.5° W) had not hosted a large megathrust earthquake during the observational period 1946–2020. Geodetic evidence suggests a prominent trench-parallel transition from strong to weak kinematic coupling in this segment, indicating varying frictional properties of the megathrust. In 2020 July and October, the occurrence of two large, but dissimilar earthquakes in this seismic gap (the Mw 7.8 Simeonof Island thrust event on 2020 July 22 followed by the Mw 7.6 Sand Point intraslab strike-slip event on 2020 October 19) presented a unique opportunity to examine the interaction between stresses on the megathrust and within the downgoing slab. We use geodetic and geophysical evidence to derive a more accurate kinematic coupling model of the megathrust in this area and show that the Mw 7.6 Sand Point earthquake within the downgoing Pacific slab, likely occurred as a result of both trench-perpendicular interseismic shear stress caused by variable kinematic coupling of the megathrust and coseismic stress changes resulting from the Simeonof Island event. Furthermore, we show that the location of the strike-slip event coincides with along-strike change in the megathrust gravitational anomaly and flexural bending of the downgoing plate, suggesting a long-term interaction between megathrust frictional properties and the structure of the plate interface and downgoing slab.
National action plans on antimicrobial resistance in Latin America: an analysis via a governance framework
Authors: Avello Paula , Collins Lisa M , Gómez Sonia A , Luna Federico , Fernández Miyakawa Mariano E , West Helen M , Iossa Graziella
Published: January 2024

In 2015, the World Health Assembly adopted a global action plan (GAP) on antimicrobial resistance (AMR). Member states were encouraged to develop their own national action plans (NAPs) in alignment with the GAP. To-date, in systematic assessments of NAPs, the Latin American specific context has not been previously analysed. Here we examined 11 Latin American NAPs published between 2015 and 2021 using content analysis. We focused on two approaches: (1) alignment between the strategic objectives and actions defined in the GAP, and those outlined in the NAPs via a content indicator; and (2) assessment of the NAPs via a governance framework covering ‘policy design’, ‘implementation tools’ and ‘monitoring and evaluation’ areas. We observed a high alignment with the strategic objectives of the GAP; however, the opposite was observed for the corresponding actions. Our results showed that the governance aspects contained within coordination and participation domains were addressed by every Latin American NAP, whereas monitoring and assessment areas, as well as incorporating the environment, would need more attention in subsequent NAPs. Given that AMR is a global health threat and collective efforts across regions are necessary to combat it, our findings can benefit member states by highlighting how to strengthen the AMR strategies in Latin America, while also supporting global policy formulation.
Management strategy evaluation of harvest control rules for Pacific Herring in Prince William Sound, Alaska
Authors: Zahner Joshua A , Branch Trevor A
Published: January 2024

Management strategy evaluation (MSE) provides a mechanism to test the relative performance of alternative management strategies on a fishery. For Pacific herring in Prince William Sound, Alaska, no directed fisheries have occurred in over 30 years, providing an opportunity to evaluate potential management strategies before a fishery is opened. Here we evaluate and compare 10 harvest control rules (HCRs) ranging from simple threshold rules to rules accounting for population age structure, biomass trends, and weight distribution using an MSE integrated with a fully Bayesian stock assessment estimation model. We developed a utility function that shows simple threshold HCRs outperform the more complex rules, especially for catch stability. According to this utility function, the best rule had a lower limit threshold than the current default rule, while the worst rule had a higher limit threshold. Our simulations demonstrate that sufficient computing power exists for MSEs based on Bayesian estimation methods, thus opening a pathway for MSEs to simulation test probabilistic control rules, which provide a buffer against scientific uncertainty and should reduce the risk of overfishing.
El proceso constituyente de Bachelet en Chile (2015-2018): razones de un fracaso (previsible)Bachelet’s constitution-making process in Chile (2015-2018): reasons for a (foreseeable) failure
Authors: Henríquez Viñas Miriam , Francisco García José
Published: January 2024

This essay contributes to the increasing comparative constitutional law literature that has been examining constitution-making failure, the factors that explains it, and the possibility of obtaining valuable lessons for the design of future processes. For this purpose, it examines the Chilean constitution-making process of 2015-2018, led by former President Michelle Bachelet. The article shows that the most relevant factors that explains this failure relates to a dynamic political and social context, the institutional design of the process, and the exclusion of political parties of the process and the lack of consensus among the political elite. However, this failure cannot be considered definitive and total. To the contrary, it was only temporary and partial, considering the influence that the process had over the next two constitution-making process that followed on the next years (2019-2022, and 2023).
Career outlook and satisfaction in the presence of workload intensification—a survey of early career pharmacists
Authors: Bradley Fiona , Hammond Michael , Braund Rhiannon
Published: January 2024

Background

The demographics of the pharmacy workforce is changing with an increased proportion of pharmacists less than 30 years old (early career pharmacists—ECPs). In parallel, the profession has experienced workload intensification and workforce attrition. It is important to understand ECPs career satisfaction to retain this section of the pharmacy profession.

Objectives

This study aimed to collect data on the current career satisfaction of ECPs, and identify workplace factors that were most important to this group. Further, to use these findings to inform sector recommendations.

Methods

A steering group of ECPs in Aotearoa New Zealand developed a survey based on one used previously. An invitation email was sent to all pharmacists who had been registered for less than 10 years and were members of the Pharmaceutical Society of New Zealand.

Results

A total of 1418 ECPs were identified and invited to participate, and responses were received by 416 of these. While 90% believe that they are making a useful contribution to the health of their patients, over half are unhappy and discontented, with over a third dissatisfied with their careers. A large proportion (44%) were considering leaving the profession in the next 5 years. The top three factors for career satisfaction were ability to progress and learn new skills, the people they work with, and the remuneration.

Conclusions

This study provides a starting point for understanding the current environment and level of dissatisfaction of young pharmacists. There are several areas of concern that need to be addressed if a strong vibrant viable pharmacy profession is to be achieved.
Persistent Low-Level Variants in a Subset of Viral Genes Are Highly Predictive of Poor Outcome in Immunocompromised Patients With Cytomegalovirus Infection
Authors: Venturini Cristina , Colston Julia M , Charles Oscar , Lankina Anastasia , Best Timothy , Atkinson Claire , Forrest Calum , Williams Charlotte A , Rao Kanchan , Worth Austen , Thorburn Doug , Harber Mark , Griffiths Paul , Breuer Judith
Published: January 2024

Background

Human cytomegalovirus (HCMV) is the most common and serious opportunistic infection after solid organ and hematopoietic stem cell transplantation. In this study, we used whole-genome HCMV data to investigate viral factors associated with the clinical outcome.

Methods

We sequenced HCMV samples from 16 immunocompromised pediatric patients with persistent viremia. Eight of the 16 patients died of complications due to HCMV infection. We also sequenced samples from 35 infected solid organ adult recipients, of whom 1 died with HCMV infection.

Results

We showed that samples from both groups have fixed variants at resistance sites and mixed infections. Next-generation sequencing also revealed nonfixed variants at resistance sites in most of the patients who died (6/9). A machine learning approach identified 10 genes with nonfixed variants in these patients. These genes formed a viral signature that discriminated patients with HCMV infection who died from those who survived with high accuracy (area under the curve = 0.96). Lymphocyte numbers for a subset of patients showed no recovery posttransplant in the patients who died.

Conclusions

We hypothesize that the viral signature identified in this study may be a useful biomarker for poor response to antiviral drug treatment and indirectly for poor T-cell function, potentially identifying early those patients requiring nonpharmacological interventions.
Insights into the antimicrobial effects of tafenoquine against Enterococcus and its biofilms
Authors: Wu Yuan , Li Huilong , Wu Pingyun , Wu Ruolan , She Pengfei
Published: January 2024

Aim

The purpose of this study is to assess the in vitro antimicrobial and anti-biofilm effects of the anti-protozoal agent tafenoquine (TAF) on Enterococcus and elucidate its underlying mode of action.

Methods and results

The present work investigated the susceptibility of TAF on 3 type strains and 11 clinical isolates of enterococci. The results indicated that TAF exhibited powerful antimicrobial activity against both of Enterococcus faecalis and Enterococcus faecium with minimum inhibitory and bactericidal concentrations ranging from 8 to 16 µg ml−1. Meanwhile, biofilm inhibition and eradication assays showed that TAF exhibited potent anti-biofilm activity against E. faecalis ATCC 29212 and E. faecium ATCC 19434. Ultra-microscopic observations revealed significant changes in bacterial morphology and structure caused by TAF, particularly for the disruption of plasma membrane. Mechanistic investigations also revealed that TAF altered both membrane permeability and potential while also impacting adenosine triphosphate production as well as reactive oxygen species generation. In addition, no detectable cytotoxicity of TAF on human cells was observed at concentrations near the minimal inhibitory concentration.

Conclusions

In summary, this study confirmed that TAF could effectively inhibit Enterococcus as well as its biofilm formation.
The structure of TRAF7 coiled-coil trimer provides insight into its function in zebrafish embryonic development
Authors: Song Xiaozhen , Hu Ruixing , Chen Yi , Xiao Man , Zhang Hong , Wu Shengnan , Lu Qing
Published: January 2024

TRAF7 serves as a crucial intracellular adaptor and E3 ubiquitin ligase involved in signal transduction pathways, contributing to immune responses, tumor progression, and embryonic development. Somatic mutations within the coiled-coil (CC) domain and WD40 repeat domain of TRAF7 could cause brain tumors, while germline pathogenic mutations contribute to severe developmental abnormalities. However, the precise molecular mechanism underlying TRAF7 involvement in embryonic development remains unclear. In this study, we employed zebrafish as an in vivo model system. TRAF7 knock down caused defects in zebrafish embryonic development. We determined the crystal structure of TRAF7 CC domain at 3.3 Å resolution and found that the CC region trimerization was essential for TRAF7 functionality during zebrafish embryonic development. Additionally, disease-causing mutations in TRAF7 CC region could impair the trimer formation, consequently impacting early embryonic development of zebrafish. Therefore, our study sheds light on the molecular mechanism of TRAF7 CC trimer formation and its pivotal role in embryonic development.
Perforated appendicitis due to fishbone
Authors: Hoang Van T , Hoang The H , Nguyen Hoang Q , Pham Ngoc T T , Vo Tien H , Chansomphou Vichit , Hoang Duc T
Published: January 2024

Appendicitis is a common condition in daily clinical practice. Appendicitis due to foreign bodies is uncommon and may result from obstruction or perforation mechanism. We present a rare case of a 43-year-old male patient who was diagnosed with perforated appendicitis due to a fish bone by imaging studies and confirmed postoperatively. Confirming the fish bone causing the perforation on images is sometimes difficult, requiring the radiologist to actively search and determine the source. In addition to appendectomy, the surgeon also needs to pay attention to removing all foreign objects and treating perforations of surrounding organs.
Inflammatory fibroid polyp of the small intestine presenting as small bowel obstruction with intussusception: a case report
Authors: Hehir Cian , Calpin Gavin , Dowling Gavin , Spillane Chloe , Kilgallen Clive , Hill Arnold D K
Published: January 2024

Inflammatory fibroid polyps (IFP) are rare benign neoplasms most commonly occurring within the respiratory tract but are rarely also observed in the gastro-intestinal tract. Herein we present the case of a 73-year-old female presenting with ileo-ileal intussusception secondary to IFP. The patient was treated with emergency laparotomy with segmental bowel resection and primary anastomosis. Histopathological analysis of the excised bowel segment initially revealed a low-grade, mural based spindle cell neoplasm with surrounding benign, reactive lymphadenopathy. Immunohistochemical analysis demonstrated that the lesional cells stained positive for Vimentin, Smooth Muscle Actin (SMA), and CD34. On secondary analysis of the specimen, the morphology and immunohistochemical profile of the mass was in keeping with IFP. No invasive malignancy was identified. Such cases have been previously reported under the pseudonym ‘the great mimicker’, due to their striking similarity to malignant processes. This case report aims to add to the small body of research reporting such atypical presentations.
A New Woman Dialogue with Aestheticism and Decadence: Netta Syrett’s Short Stories for The Yellow Book
Authors: Rose Lucy Ella
Published: January 2024

Focusing on critically neglected works by prolific writer Netta Syrett (1865–1943), this article reveals her New Woman dialogue with aestheticism and decadence in her early short stories written for the iconic 1890s periodical The Yellow Book: primarily, ‘A Correspondence’ (1895) and ‘Far Above Rubies’ (1897). Together they trace Syrett’s increasingly assertive voice and navigation of the period’s seemingly competing but intersecting aesthetic, decadent and feminist movements. I argue that Syrett uses aesthetic and decadent discourses as strategic vehicles for the articulation of the evolving feminist ideas more fully expressed in her later pro-suffrage works. Specifically, her stories register her response to the male elitism and misogyny of aestheticism and decadence through a critical engagement with their tropes (exotic setting; aestheticized interior; femme fatale) and discourses (of mythology; statuary; floriography) in order to challenge the objectification and marginalization of women by masculinist culture using its own terms of reference. Syrett’s stories are thus discursive spaces through which she articulates anxieties about women’s place in, or exclusion from, aestheticism and decadence, asserting her role in these movements as both participant and critic. This article thus offers a more comprehensive understanding of the evolving discourses of, as well as the dialogues and debates enacted by, fin-de-siècle women’s writing, shedding new light on the aesthetic and decadent movements.
The Arabidopsis SR45 splicing factor bridges the splicing machinery and the exon–exon junction complex
Authors: Fanara Steven , Schloesser Marie , Joris Marine , De Franco Simona , Vandevenne Marylène , Kerff Frédéric , Hanikenne Marc , Motte Patrick
Published: January 2024

The Arabidopsis splicing factor serine/arginine-rich 45 (SR45) contributes to several biological processes. The sr45-1 loss-of-function mutant exhibits delayed root development, late flowering, unusual numbers of floral organs, shorter siliques with decreased seed sets, narrower leaves and petals, and altered metal distribution. SR45 bears a unique RNA recognition motif (RRM) flanked by one serine/arginine-rich (RS) domain on both sides. Here, we studied the function of each SR45 domains by examining their involvement in: (i) the spatial distribution of SR45; (ii) the establishment of a protein–protein interaction network including spliceosomal and exon–exon junction complex (EJC) components; and (iii) the RNA binding specificity. We report that the endogenous SR45 promoter is active during vegetative and reproductive growth, and that the SR45 protein localizes in the nucleus. We demonstrate that the C-terminal arginine/serine-rich domain is a determinant of nuclear localization. We show that the SR45 RRM domain specifically binds purine-rich RNA motifs via three residues (H101, H141, and Y143), and is also involved in protein–protein interactions. We further show that SR45 bridges both mRNA splicing and surveillance machineries as a partner of EJC core components and peripheral factors, which requires phosphoresidues probably phosphorylated by kinases from both the CLK and SRPK families. Our findings provide insights into the contribution of each SR45 domain to both spliceosome and EJC assemblies.
A high-energy study of the supernova remnant G296.5+10.0
Authors: Eppens L K , Combi J A , Reynoso E M , García F , Mestre E , Abaroa L , Romero G E , Luque-Escamilla P L , Martí J
Published: January 2024

We report a detailed multi-wavelength study of the supernova remnant G296.5+10.0 using archival data from XMM–Newton and Fermi-LAT complemented with ATCA observations. In the X-ray band, we performed an adaptive smoothing on the double background subtracted images to construct an X-ray mosaic map with six individual observations. Below 2.0 keV, G296.5+10.0 is asymmetrical, with the south-east side of the radio shell brighter than the south-west one. The spatially resolved X-ray spectral study confirms the thermal origin of the plasma, with enhanced metal abundances, probably arising from ejecta material according to the H i and infrared ($140~{\mu \rm m}$) distributions. In the γ-ray band, we analysed 14 years of accumulated Fermi observations below 500 GeV via different fitting processes. To discuss the origin of the γ-ray emission, we compare the GeV results with H i structures probably associated with the SNR and with the radio spectral indices found at various positions towards the radio shell. Moreover, we identified diverse sources candidates to contribute γ-ray emissions observed. Also, we calculated the lepto-hadronic spectral energy distribution of the remnant for synchrotron, inverse Compton, Bremsstrahlung, and proton–proton processes. The emission at low energies can be explained by electron-synchrotron radiation, with a weak magnetic field of $B=25\, {\rm \mu G}$, while the γ-ray data can be explained by hadronic interactions. Employing the reddening-distance method, we computed a distance of 1.4 kpc for the SNR, implying an age of 14 000 yr.
Properties of the gas escaping from a non-isothermal porous dust surface layer of a comet
Authors: Skorov Yu , Reshetnyk V , Markkanen J , Mottola S , Macher W , Mokhtari O , Thomas N , Küppers M , Hartogh P
Published: January 2024

Estimation of the properties of the sublimation products leaving the cometary nucleus is one of the significant questions in the study of the dusty-gas flow following the Rosetta mission. It is widely assumed that the temperature of the water molecules emitted is the temperature of ice directly exposed to the surface. However, it is the simplest non-verified idealization if the refractory porous material lays on the surface and controls the energy driving the ice sublimation. This highly non-isothermal surface layer should change the vapour temperature as the molecules pass through it from the icy region to the vacuum. A key sustaining observation here comes from the MIRO experiment on Rosetta which measured the velocity of water vapour. The observed gas velocities are visibly higher than can be explained by emission at typical ice surface temperature. To investigate the issue, we simulate a gas flow through a non-isothermal porous dust layer and analyse the temperature of molecules emitted. Monodisperse and bimodal layers, as well as layers made of porous aggregates, are considered. Modelling is carried out for various porosity values, different particle sizes, and dust layer thicknesses. The simulation results are embedded in two-layer thermal models including the effective thermal conductivity, volumetric light absorption, and the resistance of the dust layer to the gas flow.
The mass accretion history of dark matter haloes down to Earth mass
Authors: Liu Yizhou , Gao Liang , Bose Sownak , Frenk Carlos S , Jenkins Adrian , Springel Volker , Wang Jie , White Simon D M , Zheng Haonan
Published: January 2024

We take advantage of the unprecedented dynamical range provided by the ‘Cosmic-Zoom’ project to study the mass accretion history (MAH) of present-day dark matter haloes over the entire mass range present in the Lambda cold dark matter paradigm when the dark matter is made of weakly interacting massive particles of mass 100 GeV. In particular, we complement previous studies by exploring the MAHs of haloes with mass from $10^8\ h^{-1}\,\mathrm{{\rm M}_{\odot }}$ down to Earth mass, $10^{-6}\ h^{-1}\,\mathrm{{\rm M}_{\odot }}$. The formation redshift of low-mass haloes anticorrelates weakly with mass, peaking at z = 3 for haloes of mass $10^{-4}\ h^{-1}\,\mathrm{{\rm M}_{\odot }}$. Even lower masses are affected by the free-streaming cut-off in the primordial spectrum of density fluctuations and form at lower redshift. We compare MAHs in our simulations with predictions from two analytical models based on the extended Press–Schechter theory (EPS), and three empirical models derived by fitting and extrapolating either results from cosmological N-body simulations or Monte Carlo realizations of halo growth. All models fit our simulations reasonably well over the mass range for which they were calibrated. While the empirical models match better for more massive haloes, $M\gt 10^{10}\ h^{-1}\,\mathrm{{\rm M}_{\odot }}$, the analytical models do better when extrapolated down to Earth mass. At the higher masses, we explore the correlation between local environment density and MAH, finding that biases are relatively weak, with typical MAHs for haloes in extremely low-density and in typical regions differing by less than 20 per cent at high redshift. If this result can be extrapolated to lower halo masses, we conclude that EPS theory predicts the hierarchical build up of dark matter haloes quite well over the entire halo mass range.
Recovering the gravitational potential in a rotating frame: Deep Potential applied to a simulated barred galaxy
Authors: Kalda Taavet , Green Gregory M , Ghosh Soumavo
Published: January 2024

Stellar kinematics provides a window into the gravitational field, and therefore into the distribution of all mass, including dark matter. Deep Potential is a method for determining the gravitational potential from a snapshot of stellar positions in phase space, using mathematical tools borrowed from deep learning to model the distribution function and solve the Collisionless Boltzmann equation. In this work, we extend the Deep Potential method to rotating systems, and then demonstrate that it can accurately recover the gravitational potential, density distribution, and pattern speed of a simulated barred disc galaxy, using only a frozen snapshot of the stellar velocities. We demonstrate that we are able to recover the bar pattern speed to within $15 \,\rm {per\, cent}$ in our simulated galaxy using stars in a 4 kpc subvolume centred on a Solar-like position, and to within $20 \,\rm{per\,cent}$ in a 2 kpc subvolume. In addition, by subtracting the mock ‘observed’ stellar density from the recovered total density, we are able to infer the radial profile of the dark matter density in our simulated galaxy. This extension of Deep Potential is an important step in allowing its application to the Milky Way, which has rotating features, such as a central bar and spiral arms, and may moreover provide a new method of determining the pattern speed of the Milky Way bar.
The internal dynamics and environments of Relics and compact massive ETGs with TNG50
Authors: Moura Micheli T , Chies-Santos Ana L , Furlanetto Cristina , Zhu Ling , Canossa-Gosteinski Marco A
Published: January 2024

Relic galaxies are massive, compact, and quiescent objects observed in the local Universe that have not experienced any significant interaction episodes or merger events since about z = 2, remaining relatively unaltered since their formation. On the other hand, massive and compact early-type galaxies (cETGs) in the local Universe appear to show similar properties to Relic galaxies, despite having substantial accretion history. Relic galaxies, with frozen history, can provide important clues about the intrinsic processes related to the evolutionary pathways of ETGs and the role that mergers play in their evolution. Using the high-resolution cosmological simulation TNG50-1 from IllustrisTNG project, we investigate the assembly history of a sample of massive, compact, old, and quiescent subhaloes split by satellite accretion fraction. We compare the evolutionary pathways at three cosmic epochs: z = 2, z = 1.5, and z = 0, using the orbital decomposition numerical method to investigate the stellar dynamics of each galactic kinematical component and their environmental correlations. Our results point to a steady pathway across time that is not strongly dependent on the mergers or the environment. Relics and cETGs do not show a clear preference for high- or low-density environments within the volume explored at z = 0, as they are found in both scenarios. However, the progenitors of Relic galaxies have consistently resided in high-density environments since z = 2, while cETGs were shifted to such environments at a later stage. The merger history can be recovered from the stellar kinematics imprints in the local Universe. Relics and cETGs show consistently dynamical similarities at z = 2 and differences at z = 0 to disc, bulge, and hot inner stellar halo. In the current scenario, the mergers that drive the growth of cETGs do not give rise to a new and distinct evolutionary pathway when compared to Relics.
Spatially resolving the volatile sulfur abundance in the HD 100546 protoplanetary disc
Authors: Keyte Luke , Kama Mihkel , Chuang Ko-Ju , Cleeves L Ilsedore , Drozdovskaya Maria N , Furuya Kenji , Rawlings Jonathan , Shorttle Oliver
Published: January 2024

Volatile elements play a crucial role in the formation of planetary systems. Their abundance and distribution in protoplanetary discs provide vital insights into the connection between formation processes and the atmospheric composition of individual planets. Sulfur, being one of the most abundant elements in planet-forming environments, is of great significance, and now observable in exoplanets with JWST. However, planetary formation models currently lack vital knowledge regarding sulfur chemistry in protoplanetary discs. Developing a deeper understanding of the major volatile sulfur carriers in discs is essential to building models that can meaningfully predict planetary atmospheric composition, and reconstruct planetary formation pathways. In this work, we combine archival observations with new data from the Atacama Large sub-Millimeter Array (ALMA) and the Atacama Pathfinder EXperiment (APEX), covering a range of sulfur-bearing species/isotopologs. We interpret this data using the dali thermo-chemical code, for which our model is highly refined and disc-specific. We find that volatile sulfur is heavily depleted from the cosmic value by a factor of ∼1000, with a disc-averaged abundance of S/H ∼ 10−8. We show that the gas-phase sulfur abundance varies radially by ≳3 orders of magnitude, with the highest abundances inside the inner dust ring and coincident with the outer dust ring at r ∼ 150–230 au. Extracting chemical abundances from our models, we find OCS, H2CS, and CS to be the dominant molecular carriers in the gas phase. We also infer the presence of a substantial OCS ice reservoir. We relate our results to the potential atmospheric composition of planets in HD 100546, and the wider exoplanet population.
Coronal line emitters are tidal disruption events in gas-rich environments
Authors: Hinkle Jason T , Shappee Benjamin J , Holoien Thomas W -S
Published: January 2024

Some galaxies show little to no sign of active galactic nucleus (AGN) activity, yet exhibit strong coronal line (CL) emission relative to common narrow emission lines. Many of these CLs have ionization potentials of ≥100 eV, thus requiring strong extreme ultraviolet and/or soft X-ray flux. It has long been thought that such events are powered by tidal disruption events (TDEs), but owing to a lack of detailed multiwavelength follow-up, such a connection has not been firmly made. Here, we compare coronal line emitters (CLEs) and TDEs in terms of their host-galaxy and transient properties. We find that the mid-infrared (MIR) colours of CLE hosts in quiescence are similar to those of TDE hosts. Additionally, many CLEs show evidence of a large dust reprocessing echo in their MIR colours, a sign of significant dust in the nucleus. The stellar masses and star formation rates of the CLE hosts are largely consistent with TDE hosts, with many CLEs residing within the green valley. The blackbody properties of CLEs and TDEs are similar, with some CLEs showing hot (T ≥ 40 000 K) blackbody temperatures. Finally, the location of CLEs on the peak-luminosity/decline-rate parameter space is much closer to TDEs than many other major classes of nuclear transients. Combined, these provide strong evidence to confirm the previous claims that CLEs are indeed TDEs in gas-rich environments. We additionally propose a stricter threshold of CL flux ≥1/3 × [O iii] flux to better exclude AGNs from the sample of CLEs.
Extraplanar emission in isolated edge-on late-type galaxies – I. The Hα distribution versus to the old and young stellar discs
Authors: Sardaneta Minerva M , Amram Philippe , Rampazzo Roberto , Rosado Margarita , Sánchez-Cruces Mónica , Fuentes-Carrera Isaura , Ghosh Soumavo
Published: January 2024

Isolated galaxies are the ideal reference sample to study the galaxy structure minimizing potential environmental effects. We selected a complete sample of 14 nearby, late-type, highly inclined (i ≥ 80°), isolated galaxies from the Catalogue of Isolated Galaxies (CIG) which offers a vertical view of their disc structure. We aim to study extraplanar Diffuse Ionized Gas (eDIG) by comparing the old and young disc components traced by near-infrared (NIR) and ultraviolet (UV) imaging with the Hα emission structure. We obtained Hα monochromatic maps from the Fabry–Perot (FP) interferometry, while the old and young discs structures are obtained from the photometric analysis of the 2MASS Ks band, and GALEX NUV and FUV images, thereby identifying the stellar disc and whether the eDIG is present. The Hα morphology is peculiar in CIG 71, CIG 183, and CIG 593 showing clear asymmetries. In general, geometric parameters (isophotal position angle, peak light distribution, and inclination) measured from Hα, UV, and NIR show minimal differences (e.g. Δi ≤ ±10°), suggesting that interaction does not play a significant role in shaping the morphology, as expected in isolated galaxies. From Hα maps, the eDIG was detected vertically in 11 out of 14 galaxies. Although the fraction of eDIG is high, the comparison between our sample and a generic sample of inclined spirals suggests that the phenomenon is uncorrelated to the galaxy environment. As suggested by the extraplanar UV emission found in 13 out of 14 galaxies the star formation extends well beyond the disc defined by the Hα map.
The differential rotation of the chromosphere and the quiet chromosphere in the falling and rising periods of a solar cycle
Authors: Li K J , Xu J C
Published: January 2024

The full-disc chromosphere was routinely monitored in the He i 10 830 Å line at the National Solar Observatory/Kitt Peak from 2004 November to 2013 March, and thereby, synoptic maps of He i line intensity from Carrington rotations 2032 to 2135 were acquired. They are utilized to investigate the differential rotation of the chromosphere and the quiet chromosphere during the one falling (descending part of solar cycle 23) period and the one rising (ascending part of solar cycle 24) period of a solar cycle. Both the quiet chromosphere and the chromosphere are found to rotate slower and have a more prominent differential rotation in the rising period of solar cycle 24 than in the falling period of solar cycle 23, and an illustration is offered.
Probing coherence in metal absorption towards multiple images of strong gravitationally lensed quasars
Authors: Dutta Rajeshwari , Acebron Ana , Fumagalli Michele , Grillo Claudio , Caminha Gabriel B , Fossati Matteo
Published: January 2024

We present a tomographic analysis of metal absorption lines arising from the circumgalactic medium (CGM) of galaxies at z ≈ 0.5–2, using Multi Unit Spectroscopic Explorer (MUSE) observations of two background quasars at z ≈ 2.2 and 2.8, which are two of the few currently known quasars with multiple images due to strong gravitational lensing by galaxy clusters at z ≈ 0.6 and 0.5, respectively. The angular separations between different pairs of quasar multiple images enable us to probe the absorption over transverse physical separations of ≈0.4–150 kpc, which are based on strong lensing models exploiting MUSE observations. The fractional difference in rest-frame equivalent width (ΔWr) of Mg ii, Fe ii, and C iv absorption increases on average with physical separation, indicating that the metal-enriched gaseous structures become less coherent with distance, with a likely coherence length-scale of ≈10 kpc. However, ΔWr for all the ions vary considerably over ≈0.08–0.9, indicating a clumpy CGM over the full range of length-scales probed. At the same time, paired Mg ii absorption is detected across ≈100–150 kpc at similar line-of-sight velocities, which could be probing cool gas clouds within the same halo. No significant dependence of ΔWr is found on the equivalent width and redshift of the absorbing gas and on the galaxy environment associated with the absorption. The high-ionization gas phase traced by C iv shows a higher degree of coherence than the low-ionization gas phase traced by Mg ii, with ≈90 per cent of C iv systems exhibiting ΔWr ≤ 0.5 at separations ≤10 kpc compared to ≈50 per cent of Mg ii systems.