bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular and Seroepidemiologic Characteristics ofStaphylococcus aureus in Children with Cystic Fibrosis
Authors: Ryan Vivian G , Creech C Buddy , Soper Nicole R , Yoder Sandra M , Brady Eric , Thomsen Isaac P , Sokolow Andrew G
Published: October 2024

Background

Cystic fibrosis (CF), through altered sodium and chloride transport across the CF transmembrane receptor (CFTR), is associated with poor mucus clearance, bacterial colonization of the lower airway, chronic pulmonary disease punctuated by acute exacerbations, and chronic inflammation. With increased use of CFTR modulators, changes in the CF pulmonary microbiome have been observed, including decreased prevalence of Pseudomonas colonization; however, overall S. aureus prevalence remains largely unchanged. An important remaining question is whether changes in the CF pulmonary microbiome, while not affecting the overall prevalence of S. aureus colonization, has led to changes in S. aureus diversity or the strain types that are most frequently recovered from children with CF. It is also unknown whether the humoral immune response to S. aureus is altered in the presence of CFTR modulator therapy.

Methods

Genomic DNA was extracted from S. aureus isolates obtained from two cohorts: a historic cohort, comprised of children not receiving CFTR modulators, and a modern cohort, comprised of children receiving CFTR modulator therapy. Multilocus sequence typing (MLST) and whole genome sequencing (WGS) were used to identify clonotype and characterize virulence factors of interest. Serum was obtained from participants and antibody titers to the extracellular toxins LukAB and LukED were measured.

Results

One hundred participants were enrolled: 50 in cohort 1 (historic) and 50 in cohort 2 (modern). Compared to cohort 1, isolates identified in cohort 2 were less likely to contain ACME and mecA; similarly, cohort 2 isolates were more likely to contain PVL, sek, and sak. The frequency of specific clonotypes changed over time, with increased prevalence of CC8 and decreased prevalence of CC1, CC5, CC15, and CC30 in cohort 2 compared to cohort 1 (Figure 1A). Serum antibody concentrations to LukAB, a conserved toxin across S. aureus, were similar across cohorts (Figure 1B).

Conclusion

Over time, the clonotypes responsible for S. aureus colonization in patients receiving CFTR modulators have changed. Despite changes in clonotypes and receipt of CFTR modulators, serum concentrations of LukAB-specific antibodies did not differ. These data suggest that staphylococcal colonization in patients with CF is dynamic over time and may be modified based on the receipt of CFTR modulator therapy.

Figure 1. (A) S. aureus clonal complexes, over time, demonstrating a relative increase in CC8 between 2012 and 2022; (B) serum concentrations of LukAB antibodies from 2012 (historic) and 2022 (modern) cohorts. No significant difference was observed in median anti-LukAB concentrations.
New US DHHS Guidelines for Feeding of HIV Exposed Infants: Uptake, Practice Variability and Concerns
Authors: Eisenberg Ilan Rozen , Campbell Jeffrey , Clarke Diana , Cooper Ellen , Pelton Stephen , Vuppula Sharon
Published: October 2024

Background

Approximately 5000 infants are born to mothers living with HIV annually in the US. In the past, the Center for Disease Control (CDC), American Academy of Pediatrics (AAP), and US Department of Health and Human Services (DHHS) have recommended that people living with HIV (PWH) not breast/chest feed their infants. Recent changes published in January 2023 in the “Section on Infant Feeding for Individuals Living with HIV” in the US DHHS HIV Guidelines, now include that individuals with HIV who are on antiretroviral therapy (ART) with a sustained undetectable viral load (VL) and who choose to breastfeed should be supported in this decision. We evaluated the uptake of these guidelines, and practice variability across providers who care for such mothers and infants.

Methods

We surveyed Pediatric Infectious Diseases Society members who practice clinically in the US, via an internal email list serve. The ten-question survey assessed uptake of the updated DHHS guidelines and respondents’ clinical practice in three key areas that are subject to interpretation in the guidelines: VL control, mixed feeding, and ART prophylaxis. We used descriptive statistics to examine guideline uptake and variability in practice. We used inductive qualitative thematic analysis to identify themes in open-ended survey responses.

Results

Of 915 individuals who opened the survey, 165 responded and 129 were included in the final analysis. Respondents represented 86 US clinical centers. Uptake varied: 14 respondents (10.8%) were unaware of the new guidelines, 103 (79.8%) had implemented or were planning to implement the new guidelines, and 12 (9.3%) were not planning to implement the guidelines. The table summarizes variability in pre-delivery VL suppression and mixed feeding criteria used by 117 respondents who are either planning/already implementing guidelines or who are unaware of guidelines. Areas of concern revealed by thematic analysis included insufficient data to support guidelines and lack of specific criteria for implementation.

Conclusion

We identified substantial heterogeneity in provider uptake and comfort with new breastfeeding guidelines among US pediatric infectious diseases practitioners, and variability in assessment of safety to breastfeed. Further research is essential to explore patient preferences, define necessary follow-up, and address provider concerns regarding insufficient data to support guidelines and lack of specific criteria for implementation.
STI Rates Among High-Risk Youth Undeterred During Early COVID-19 In A HIV Care Clinic
Authors: Bittle Elspeth , Patel Nehali , Knapp Katherine , Green Amanda
Published: October 2024

Background

In recent years, the United States has observed increasing rates of sexually transmitted infections (STIs). Rates are highest amongst the teen and young adult age groups. In addition to the immense healthcare costs associated with STIs, long-term sequelae can be severe on the individual level. The risk of infertility is particularly high for those with repeated or prolonged infection. Upon entering the COVID-19 pandemic, it was unclear if the widespread behavioral changes and disruptions in routine care practices to minimize the further spread of COVID-19 would cause an increase or decrease in the United States’ STI rates. This study sought to determine if there was a change in the incidence of STIs during the first year of the COVID-19 pandemic compared to the year prior in a population at high risk for STIs.

Methods

A retrospective chart review was performed for 330 patients aged 12 to 41 years (mean 20.2 years, median 20 years, standard deviation 3.75 years) with human immunodeficiency virus (HIV) or on pre-exposure prophylaxis (PrEP) to prevent the acquisition of HIV, who presented for preventative and acute care appointments at a multidisciplinary pediatric and young adult HIV Clinic in the year prior to and during the first year of the COVID-19 pandemic (March 22, 2019-March 21, 2021). Utilizing telehealth, rapid COVID-19 screening, and multimodal patient communication, increased efforts were made in this clinic during the pandemic to maintain appropriate STI screening, testing, treatment, and rescheduling of routine visits when appropriate to minimize COVID-19 exposure and spread. Comparisons were made between the two time periods, which evaluated the incidences of individual and overall STIs diagnosed per person-years, STIs per total tests performed, and time to treatment initiation.

Results

Between one year prior to and the first year during the COVID-19 pandemic, this clinic experienced no statistically significant rate changes of sexually transmitted infections. A non-significant decreased incidence of chlamydia (22 cases per 100 person-years and 18 cases per 100 person-years, respectively) and unchanged rates of gonorrhea (22 cases per 100 person-years and 22 cases per 100 person-years, respectively) and syphilis (16 cases per 100 person-years and 15 cases per 100 person-years, respectively) were observed. The median times to treatment remained largely unchanged.

Conclusion

This HIV care clinic experienced a decreased chlamydia infection rate, a trend similar to the CDC United States STI data during this time period. In contrast to the nationally reported increased rates of gonorrhea and syphilis, this clinic experienced unchanged rates. The lack of change in our cohort could reflect that the benefits of a multidisciplinary HIV care model persist despite a pandemic that disrupted routine medical care and behavior practices.
Antibody responses to re-immunization in recipients of allogeneic hematopoietic cell transplantation
Authors: Hijano Diego R , Bhoopalan Senthil , Zeng Emily , Selukar Subodh , Sharma Akshay , Maron Gabriela
Published: October 2024

Background

Immunologic memory against vaccine-preventable diseases is often lost after an allogeneic hematopoietic cell transplant (allo-HCT), therefore recipients are required to be re-immunized after allo-HCT to regain immunity against these infections. But the response to vaccination after an allo-HCT can be highly variable and is not well understood. We performed a single center retrospective study to examine immunization practices and determine the rate of vaccine protection and seroconversion following vaccination after allo-HCT.

Methods

Electronic medical records (EMR) from patients ≤18 years of age who underwent allo-HCT at St. Jude Childrens’ Research Hospital between 2005 - 2021 were reviewed. Clinical information and serology results before and after completion of the immunizations series were extracted from the EMR. The vaccines included in this analysis were diphtheria, measles, mumps, rubella (MMR), varicella, and polio. Protection was evaluated only for infections with established immune correlates. Seroconversion was defined as 4-fold increase in titers for vaccines with quantitative antibody assays, or as a change from negative to positive IgG for vaccines with qualitative antibody tests.

Results

760 patients were included in this cohort. Demographic and clinical data are summarized in Table 1. The mean age at allo-HCT was 10.4 years, most were male (56.8%) and white (74.6%). Acute leukemia accounted for 66.4% of allo-HCT recipients. Conditioning was myeloablative for 53.45%, and reduced intensity for 37.9%. Most received transplants from mismatched-related donors, (44.9%), followed by matched unrelated donors (35.4%) and matched related donors (19.5%). The number of patients who received the full vaccination series at our institution differed by vaccine and ranged from 41-150, and the respective subsets with available pre-vaccination and post-vaccination titers ranged from 24-93. The median time from transplant to initiation of immunizations was 12 months (range: 6-58) for non-live vaccines, 25 months (range: 23, 63) for MMR vaccine, and 28 months (range: 16, 117)) for varicella vaccine. Protection post immunization varied, with less patients demonstrating protections for mumps (79%) and measles (82%) (Figure 1). Seroconversion also varied among the different vaccine components and types of vaccines.

Conclusion

Current strategies to re-immunize patients after allo-HCT do not provide protection to all patients. Understanding the factors associated with suboptimal immune responses is critical for advancing our knowledge in this area. Whether time-based approaches combined with immune reconstitution data are required to further optimize protection remains unclear. Additionally, different vaccine schedules (i.e., higher doses) may be required in these patients.

Figure 1. Protection and seroconversion rate by vaccine target.
Association Between Measurable Residual Levels and Infection Mortality in Acute Myeloid Leukemia
Authors: Gomez S , Deana A , Ruiz C , Riccheri C , Caniza M
Published: October 2024

Background

Acute myeloid leukemia (AML) outcomes have improved over the years. Better AML disease risk classification, achieved by measuring minimal residual disease (MRD) levels, has contributed to improved treatment and survival. Even though the role of MRD in survival is still preliminary, results are promising. However, infections are still a problem to circumvent. In our previous protocol LMA-GATLA 2007 we found a 30% incidence of sepsis related death (SRD), and they were more frequent during or after first induction. The overall survival of that study was 51.4 % (0.38). In this study, we aimed to analyze the mortality rates due to infection; and determine if there is an association of the MRD levels and infection mortality rates; also, we will analyze overall outcomes of AML.

Methods

Patients were accrued form the National Registry GATLA LMA 2021 protocol. Disease risks were classified based on cytogenetics and molecular abnormalities as standard risk (SR), high risk (HR), and very high risk (VHR). MRD determinations were performed using flow cytometry after 1st induction with mitoxantrone, anthraciclines and etoposide (MAE) protocol, at day 22 and 29 and after 2nd induction with high dose citarabine and mitoxantrone (HAM). We used descriptive statistics (analysis by frequency), compared categorical variables using chi-square or χ2 test and Fisher test, and time to event calculation techniques.

Results

95 patients have been accrued, 51.6 % were males. The median age was 9 years of age (IQR 3-13), and 31% were SR, 22% HR, and 47% VHR. MRD levels < 0.1% were seen in 55.5% post first induction, 92% post intensification and 85% post consolidation. Estimated probability of overall survival was 65% (ES 0.6) at 45.7 (2.7) months, (CI 95% 40.3-51,1). 23 pts (24%) died; 11 (48 %) for progression, 7 (30%) for sepsis, for non-sepsis toxicity 3 (13%), other causes 2 pts (9%). Hazard ratio of death with MRD > 0.1% was 2.35 (p=0.06, 95% CI 0.043-1.756). The incidence of SRD was 7.4%, 4 patients had sepsis with MRD < 0.1% (57 %), after HAM /consolidation phase; and 3 patients with > 0.1% (43%) when in relapse (p= 0.028). The SRD episodes were independent from MRD levels, however patients on remission showed SRD as late events, because no patient developed SRD during or after first induction.

Conclusion

Overall survival results have improved with current protocol. MRD seems a valuable tool to estimate response, levels >0.1 % are associated with increased risk of death. However, better infection prevention and care are required to improve further the outcomes, especially those associated with higher MRD levels.
Clinical Characteristics, Management, and Outcomes of Bacteremia in Children with Cancer: A Retrospective Study
Authors: Hancock Asher , Chen Yichen , Chung Hyun Jy , Carrillo Angela K , Faughnan Lane , Staples Courtney , Villegas César A , Bhattacharyya Parthasarathi , Escobedo Griselda , Devidas Meenakshi , Licona Sergio , Mukkada Sheena
Published: October 2024

Background

Bacteremia is a common infectious complication among pediatric oncology patients, yet management practices are not standardized. Antibiotic treatment courses as short as seven days are supported by literature and could improve patient quality of life and resource use. However, it is not known if short courses are associated with greater treatment failure in immunocompromised patients.

Methods

We conducted a retrospective study at St. Jude Children’s Research Hospital, including patients with a laboratory confirmed bloodstream bacterial infection between April 1, 2022, and March 31, 2023. Clinical characteristics such as age, gender, type of malignancy, phase of treatment, underlying chronic conditions, and clinical sites of infection were collected. Antibiotics used, duration of therapy, and route of administration were also gathered to examine clinical management. Clinical outcomes were measured by documenting ICU admission, oxygen, fluid and vasopressor requirements, date of hospital discharge, bacteremia recurrence, and mortality.

Results

86 patients contributed 112 bacteremia episodes that met eligibility criteria. Severe neutropenia was present at onset in 68% of all episodes and 32% of patients did not have neutrophil recovery over 500 cells/ml during the episode. Gram-negative organisms accounted for 52% of isolated organisms, with the most common organisms isolated overall being Escherichia coli (19%), followed by Klebsiella pneumoniae (14%), and Viridans group streptococcus (14%). The median length of antibiotic treatment was 12 days. Treatment duration was not associated with oncologic diagnosis or Gram-negative versus Gram-positive infection.

Conclusion

Bacteremia occurs more frequently in patients who are neutropenic, especially those who are severely neutropenic with an absolute neutrophil count less than 500 cells/mL. Treatment duration is not associated with primary cancer diagnosis or type of bacteremia. In this single high resource setting, bloodstream infections resulted in significant morbidity, resource use, and a mortality rate of 8%, highlighting opportunities for investigation to improve clinical practices.
Evaluation of effective strategies in the prevention of chemotherapy induced mucositis among Children
Authors: Safdar Dilnasheen , Panjawani Rehana
Published: October 2024

Background

Oral mucositis is a frequent side effect of anticancer treatments. It impairs the patient’s quality of life, aggravate clinical condition, increase the risk of infection and can delay anticancer treatment. Health care workers at the NIBD and BMT Karachi, Pakistan emphasize on oral hygiene to prevent such complications for the patients. Proper oral hygiene protocol can reduce the risk of oral ulcers. In this study we have done the evaluation of oral hygiene. At NIBD and BMT among pediatric population are advice to brush their teeth twice a day, use pyodine/ Chlorhexidine 0.2% mouth wash thrice a day followed by application of anti-fungal jell.

Methods

A cross-sectional survey was conducted from date 8/5/2020 to 11/5/2020 at children hospital. 73 admitted patients were the study using convenient sampling, team approached eligible patients and informed consent was obtained from parents. A standardized questionnaire was then administered in Urdu (Pakistan’s national language).

Results

11% of patients reported that they frequently or always suffered from oral ulcer and use mouth washes for gargles; however 79.5% reported that they rarely or never suffered from oral ulcer and use mouth washes. In contrast, 9.6% patients reported that they rarely or never suffered from oral ulcer and do not use mouth washes, whereas none of the patients who reported that they do not use mouth washes for gargles had suffered from oral ulcer frequently or all the time. 2.7% of the patients experienced oral ulcer frequently or always and brush once in a day, 6.8% experienced oral ulcer frequently or always and brush twice or more in a day and 1.4% don’t brush and suffered from oral ulcer frequently or always. Conversely, 27.4% never or rarely had oral ulcer and brush once in a day, 54.8% never or rarely had oral ulcer and brush twice or more in a day and 6.8% don’t brush and had never or rarely experienced oral ulcer

Conclusion

The use of proper oral hygiene protocol can decrease the risk of chemotherapy induced mucositis. Majority of the patients at NIBD 02 + 103 understand the importance of oral hygiene after their doctor’s Furthermore oral hygiene can decrease levels of oral mucositis and eventually decrease inpatient admissions, delays in treatments and improving the quality of life.
Infection Mortality in Acute Promyelocytic Leukemia in Children
Authors: Sergio Gomez , Cecilia Riccheri , Claudia Ruiz , Alejandra Deana , Cecilia Garbini , Federico Filardi , Estefania Tarsetti , Elena Sossi Maria , Miguela Caniza
Published: October 2024

Background

Acute promyelocytic leukemia (APL) is a rare entity in children. The percentage of APL patients is 5-7% of all pediatric acute myeloid leukemia cases; a higher frequency (about 20%) is reported in children of Latino/Hispanic ancestry. The introduction of trans retinoic acid has been crucial for both antileukemic efficacy in APL and for prevention of early deaths. Furthermore, the use of arsenic trioxide (ATO) demonstrated to be highly effective in achieving high cure rates with reduced toxicity. However, there is a paucity of data concerning infection related deaths in APL. The objective was to describe the percentage of infection-related-deaths in APL in children; to describe the event free survival (EFS) and describe other main complications observed.

Methods

We identified 30 patients, as part of the Hospital Alejandro Posadas registry from a single center. We conducted a retrospective observational descriptive analysis. The patients were treated with the GIMEMA-AIDA 2000 protocol (n=23, 76.7%) and 1-LPA pediatrico-18-GALTA/CLEHOP (n=6, 20%). One patient died before treatment was given. The patients were diagnosed between 2000 to 2022. We used frequencies for descriptive variables, Chi2 /Fisher test for categorical data and time to event techniques for survival analysis. Any cause of mortality was extracted and analyzed.

Results

There were 66.7% of males; and median age was 12-year (IQR 8-15). PML-Rar alfa was positive (cytogenetics) in 23 (76.7%); Negative 6 (20%) and failed in 1 patient (3.3%). 100% had positive molecular biology for PML-rarAlfa transcript. Median white cells were 3.35x 109 /l (IQR 1.675-13.25). The patients were classified as high-risk (n=10, 33.3%) and standard risk (n=20, 66.7%). Four patients showed molecular relapse, 2 had CNS and one bone marrow involvement. Three patients died (10%), 2 due to endocranial hemorrhage, 1 as a consequence of complications of a hematological relapse. No patient died due to microbiologically documented infection or febrile neutropenia. With a mean estimated survival time (median not achieved) in years of 17.7 years, (CI 95% 14.6-20.7) the event free survival was 79% (SE 0.75), with 6 events. Cumulative competitive incidence of relapse 14% (SE 0.65).

Conclusion

In patients with APL, we could not find infections as cause of death. The overall results of APL management were very promising.

Figure 1. Event Free Survival Acute Promyelocytic Leukemia.
Rhein induces apoptosis of AGS and MGC803 cells by regulating the Ras/PI3K/AKT and p38/MAPK signaling pathway
Authors: Wan Meiqi , Gan Anna , Dai Jun , Lin Fei , Wang Ruixuan , Wu Bo , Yan Tingxu , Jia Ying
Published: October 2024

Objectives

Rhein is one of the main bioactive compounds in the Polygonaceae plant, and has been proven to have anti-cancer activity in some reports. But the mechanism of Rhein in the treatment of gastric cancer (GC) is limited reported. In this research, network pharmacology combined with in vitro experiments was used for systematically studying the mechanism of Rhein.

Methods

Network pharmacology confirmed the major effect signaling pathway and key targets of Rhein in the treatment of GC. Cell viability assay, colony formation assay, fluorescence probe assay, apoptosis assay, western blot and qRT–PCR verified the mechanism of Rhein in the treatment of GC cells (AGS and MGC803 cells).

Key findings

The results showed that Rhein significantly induced the apoptosis process of AGS and MGC803 cells by regulating the Ras/phosphoinositide-3 kinase (PI3K)/protein kinase B (AKT) and the p38/mitogen-activated protein kinase signaling pathways. The AKT activator (SC79) and p38 inhibitor (SB202190) inhibited Rhein-induced apoptosis.

Conclusions

All results proved that Rhein could be recognized as a potential natural drug for the treatment of GC.
tdCoxSNN: Time-dependent Cox survival neural network for continuous-time dynamic prediction
Authors: Zeng Lang , Zhang Jipeng , Chen Wei , Ding Ying
Published: October 2024

The aim of dynamic prediction is to provide individualized risk predictions over time, which are updated as new data become available. In pursuit of constructing a dynamic prediction model for a progressive eye disorder, age-related macular degeneration (AMD), we propose a time-dependent Cox survival neural network (tdCoxSNN) to predict its progression using longitudinal fundus images. tdCoxSNN builds upon the time-dependent Cox model by utilizing a neural network to capture the nonlinear effect of time-dependent covariates on the survival outcome. Moreover, by concurrently integrating a convolutional neural network with the survival network, tdCoxSNN can directly take longitudinal images as input. We evaluate and compare our proposed method with joint modelling and landmarking approaches through extensive simulations. We applied the proposed approach to two real datasets. One is a large AMD study, the Age-Related Eye Disease Study, in which more than 50,000 fundus images were captured over a period of 12 years for more than 4,000 participants. Another is a public dataset of the primary biliary cirrhosis disease, where multiple laboratory tests were longitudinally collected to predict the time-to-liver transplant. Our approach demonstrates commendable predictive performance in both simulation studies and the analysis of the two real datasets.
Oculomotor compressive neuropathy secondary to calcifying pseudoneoplasm of the neuraxis (CAPNON)
Authors: Alzate-Carvajal Verónica , Madriñán-Navia Humberto Jose , Escobar Luis Alberto , Moreno-Huertas Camilo E
Published: October 2024

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is an uncommon entity and a rare cause of third cranial nerve palsy. We review the case of a 17-year-old male with a 9-month history of progressive left third cranial nerve palsy. Cerebral magnetic resonance image showed a left clinoidal lesion with low signal intensity in T2 and T1 sequences with signs of calcification in the computed tomography and without vascular lesion in AngioMRI. A left pterional approach was performed with posterior clinoidectomy and total resection of the lesion. Calcifying pseudoneoplasm of the neuraxis is an infrequent pathology that presents in the skull base and spine that requires surgical treatment in the presence of compressive phenomena and differential diagnosis as meningioma, chordoma, and metastasis should be considered.
Grain lysine enrichment and improved stress tolerance in rice through protein engineering
Authors: Rathore Ray Singh , Mishra Manjari , Pareek Ashwani , Singla-Pareek Sneh Lata
Published: October 2024

Amino acids are a major source of nourishment for people living in regions where rice is a staple food. However, rice grain is deficient in essential amino acids including lysine. The activity of the enzyme dihydrodipicolinate synthase (DHDPS) is crucial for lysine production in higher plants, but it is tightly regulated through feedback inhibition by its end product, lysine, leading to limited activity in the grain and resulting in low lysine accumulation. We identified lysine binding sites in the DHDPS enzyme and introduced key mutations to make DHDPS lysine feedback insensitive. Using in vivo analysis and functional complementation assays, we confirmed that protein engineering of the DHDPS renders it insensitive to lysine. Expression of mutated DHDPS resulted in 29% higher lysine and 15% higher protein accumulation in rice grains than in the wild type. Importantly, the lysine content in transgenic grains was maintained in cooked rice. The transgenic plants also exhibited enhanced stress tolerance along with higher antioxidant levels, improved photosynthesis, and higher grain yield compared to wild-type plants. We have shown that protein engineering of DHDPS in rice can lead to accumulation of lysine in grains and impart abiotic stress tolerance. This approach could improve health in regions with nutrient deficiencies and environmental stressors that challenge food production and human health.
MV-frames
Authors: Nganou Jean B
Published: October 2024

Each complete MV-algebra is naturally equipped with a structure of a frame. For this reason, we shall call such MV-algebras MV-frames and investigate some of their main frame properties. We completely characterize algebraic MV-frames as well as regular MV-frames. In addition, we consider nuclei on MV-frames in general and on MV-frames of ideals of Łukasiewicz rings in particular. Finally, we use the Chang–Mundici functor to explore the frame structures of complete unital lattice-ordered groups.

2010 Mathematics Subject Classification. 06D35, 06E15, 06D50
Volatile composition of the HD 169142 disc and its embedded planet
Authors: Keyte Luke , Kama Mihkel , Booth Alice S , Law Charles J , Leemker Margot
Published: October 2024

The composition of a planet’s atmosphere is intricately linked to the chemical makeup of the protoplanetary disc in which it formed. Determining the elemental abundances from key volatiles within discs is therefore essential for establishing connections between the composition of discs and planets. The disc around the Herbig Ae star HD 169142 is a compelling target for such a study due to its molecule-rich nature and the presence of a newly forming planet between two prominent dust rings. In this work, we probe the chemistry of the HD 169142 disc at small spatial scales, drawing links between the composition of the disc and the planet-accreted gas. Using thermochemical models and archival data, we constrain the elemental abundances of volatile carbon, oxygen, and sulfur. Carbon and oxygen are only moderately depleted from the gas phase relative to their interstellar abundances, with the inner ~60 au appearing enriched in volatile oxygen. The carbon-to-oxygen ratio is approximately solar within the inner disc (~0.5) and rises above this in the outer disc (>0.5), as expected across the H$_2$O snowline. The gas-phase sulfur abundance is depleted by a factor of ~1000, consistent with a number of other protoplanetary discs. Interestingly, the observed SiS emission near the HD 169142 b protoplanet vastly exceeds chemical model predictions, supporting previous hypotheses suggesting its origin in shocked gas or a localized outflow. We contextualize our findings in terms of the potential atmospheric composition of the embedded planet, and highlight the utility of sulfur-bearing molecules as probes of protoplanetary disc chemistry.
Ultraluminous X-ray sources with He star companions
Authors: Li Luhan , Wang Bo , Liu Dongdong , Guo Yunlang , Chen Wen-Cong , Han Zhanwen
Published: October 2024

Ultraluminous X-ray sources (ULXs) are non-nuclear point-like objects observed with extremely high X-ray luminosity that exceeds the Eddington limit of a $\rm 10\, M_\odot$ black hole. A fraction of ULXs has been confirmed to contain neutron star (NS) accretors due to the discovery of their X-ray pulsations. The donors detected in NS ULXs are usually luminous massive stars because of the observational biases. Recently, the He donor star in NGC 247 ULX-1 has been identified, which is the first evidence of a He donor star in ULXs. In this paper, we employed the stellar evolution code mesa (Modules for Experiments in Stellar Astrophysics) to investigate the formation of ULXs through the NS+He star channel, in which a He star transfers its He-rich material onto the surface of an NS via Roche lobe overflow. We evolved a large number of NS+He star systems and provided the parameter space for the production of ULXs. We found that the initial NS+He star systems should have $\sim 0.7\!-\!2.6 \, \mathrm{M}_\odot$ He star and $\sim 0.1\!-\!2500\, \mathrm{d}$ orbital period for producing ULXs, eventually evolving into intermediate-mass binary pulsars. According to binary population synthesis calculations, we estimated that the Galactic rate of NS ULXs with He donor stars is in the range of $\sim 1.6\!-\!4.0\times 10^{-4}\, {\rm yr}^{-1}$, and that there exist $\sim 7-20$ detectable NS ULXs with He donor stars in the Galaxy.
On the membership of variable stars in Galactic globular clusters: the Oosterhoff gap
Authors: Prudil Z , Arellano Ferro A
Published: October 2024

We have performed a critical evaluation of the membership status of all variable stars in globular clusters recorded in the Catalogue of Variable Stars in Globular Clusters (CVSGC) curated by Christine Clement. To this end, we employed the systematic and bulky membership analysis performed by E. Vasiliev and H. Baumgardt based on the proper motions and parallaxes given in Gaia-EDR3. We found numerous variables in the CVSGC which are in fact field stars, which is particularly the case for globular clusters located in the Galactic bulge. Using the newly acquired list of reliable cluster members we examine the Oosterhoff dichotomy present among the Milky Way (MW) globular clusters using their RR Lyrae stars content. We confirm the presence of the Oosterhoff gap, separating both Oosterhoff groups. The Oosterhoff gap is mostly populated by globular clusters associated with MW dwarf galaxies and globular clusters with a low number of fundamental mode RR Lyrae variables. Several of the clusters in the Oosterhoff gap were previously linked to past merger events (e.g. Kraken/Heracles).
HD 28185 revisited: an outer planet, instead of a brown dwarf, on a Saturn-like orbit
Authors: Venner Alexander , An Qier , Huang Chelsea X , Brandt Timothy D , Wittenmyer Robert A , Vanderburg Andrew
Published: October 2024

As exoplanet surveys reach ever-higher sensitivities and durations, planets analogous to the Solar system giant planets are increasingly within reach. HD 28185 is a Sun-like star known to host a $m\sin i=6~M_\mathrm{ J}$ planet on an Earth-like orbit; more recently, a brown dwarf with a more distant orbit has been claimed. In this work, we present a comprehensive re-analysis of the HD 28185 system, based on 22 yr of radial velocity (RV) observations and precision Hipparcos–Gaia astrometry. We confirm the previous characterization of HD 28185 b as a temperate giant planet, with its $385.92^{+0.06}_{-0.07}$ d orbital period giving it an Earth-like incident flux. In contrast, we substantially revise the parameters of HD 28185 c; with a new mass of $m=6.0\pm 0.6~M_\mathrm{ J}$, we reclassify this companion as a super-Jovian planet. HD 28185 c has an orbital period of $24.9^{+1.3}_{-1.1}$ yr, a semimajor axis of $8.50^{+0.29}_{-0.26}$ au, and a modest eccentricity of $0.15\pm 0.04$, resulting in one of the most Saturn-like orbits of any known exoplanet. HD 28185 c lies at the current intersection of detection limits for RVs and direct imaging, and highlights how the discovery of giant planets at $\approx$10 au separations is becoming increasingly routine.
Reversing arrested development: a new method to address halo assembly bias
Authors: Smith William J , Berlind Andreas A , Sinha Manodeep
Published: October 2024

Halo assembly bias is a phenomenon whereby the clustering of dark matter haloes is dependent on halo properties, such as age, at fixed mass. Understanding the origin of assembly bias is important for interpreting the clustering of galaxies and constraining cosmological models. One proposed explanation for the origin of assembly bias is the truncation of mass accretion in low-mass haloes in the presence of more massive haloes, called ‘arrested development’. Haloes undergoing arrested development would have older measured ages and exhibit stronger clustering than equal mass haloes that have not undergone arrested development. We propose a new method to test the validity of this explanation for assembly bias and correct for it in cosmological N-body simulations. The method is based on the idea that the early mass accretion history of a halo, before arrested development takes effect, can be used to predict the late-time evolution of the halo in the absence of arrested development. We implement this idea by fitting a model to the early portion of halo accretion histories and extrapolating to late times. We then calculate ‘corrected’ masses and ages for haloes based on this extrapolation and investigate how this impacts the assembly bias signal. We find that correcting for arrested development this way leads to a factor of two reduction in the strength of the assembly bias signal across a range of low-halo masses. This result provides new evidence that arrested development is a cause of assembly bias and validates our approach to mitigating the effect.
An alternative interpretation of magnetars’ traits deduced from the observational data on their outburst fluxes and spectra
Authors: Ardavan Houshang
Published: October 2024

By applying the Efron–Petrosian method to the fluxes S and distances D of the magnetars listed in the Magnetar Outburst Online Catalogue, we show that the observational data are consistent with the dependence $S\propto D^{-3/2}$, which characterizes the emission from the superluminally moving current sheet in the magnetosphere of a non-aligned neutron star, at substantially higher levels of significance than they are with the dependence $S\propto D^{-2}$. This result agrees with that previously obtained by an analysis of the data in the McGill Online Magnetar Catalog and confirms that, contrary to the currently prevalent view, magnetars’ X-ray luminosities do not exceed their spin-down luminosities. The X-ray spectra of magnetars, moreover, are congruous with the spectral energy distribution (SED) of a broad-band non-thermal emission mechanism identical to that at play in rotation-powered pulsars: we show that the SED of the caustics that are generated in certain privileged directions by the magnetospheric current sheet single-handedly fits the observed spectra of 4U 0142+61, 1E 1841−045, and XTE J1810−197 over their entire breadths. Magnetars’ outbursts and their associated radio bursts are predicted to occur when, as a result of large-scale timing anomalies (such as glitches, quakes, or precession), one of the privileged directions along which the radiation from the current sheet decays more slowly than predicted by the inverse-square law either swings past or oscillates across the line of sight.
Occupational well-being of diplomatic personnel: a qualitative study
Authors: Brooks S K , Patel D , Greenberg N
Published: October 2024

Background

Diplomatic personnel face unique job demands due to their frequent relocations. There is some evidence that occupational stress contributes to poor well-being in this occupational group, but little research on the aspects of the job that are perceived to be particularly challenging.

Aims

This study aimed to explore diplomatic personnel’s perceptions of their organization and their roles and to identify aspects of the job, which could cause stress and potentially affect well-being.

Methods

Semi-structured interviews were carried out with 24 employees of the Foreign, Commonwealth and Development Office between September 2021 and February 2022. Participants were asked to reflect on their experiences before the coronavirus disease 2019 pandemic. Thematic analysis was used to analyse data.

Results

Participants enjoyed many aspects of their work including the variety, travel opportunities and feeling that they made a difference. They also identified several stressors relating to job demands, overseas postings, family needs, frequent relocation, hardship posts, workplace relationships, (lack of) appreciation and acknowledgement, and organizational culture. Good relationships with colleagues and managers were perceived to be very important.

Conclusions

Findings suggest various ways in which diplomatic organizations can better support their personnel, highlighting workload management; cross-cultural training; providing appropriate support to both accompanying families and unaccompanied staff members; practical and psychological preparation for those in high-risk locations; encouraging positive workplace relationships; good management; increased autonomy and increased recognition for good work.
Anorexia nervosa with comorbid autism spectrum disorder: Optimizing care for youth, caregivers, and health care providers
Authors: Coret Alon , Agostino Holly
Published: October 2024

Youth with anorexia nervosa (AN) have been reported to have high levels of comorbid autism spectrum disorder (ASD) and ASD-like traits suggesting a potential shared underlying neurodevelopmental or genetic link between the disorders. Youth with comorbid AN and ASD symptomatology generally require more intensive treatment and have worse psychological outcomes following treatment. To date, no Canadian national guidelines exist for the treatment of this comorbidity. An informal survey of tertiary paediatric eating disorder programs across Canada revealed that centres do not routinely screen for ASD at intake and few offer any treatment modifications for youth with AN and suspected/diagnosed comorbid ASD. This represents a significant care gap for this clinical sub-population and an important area for future study and healthcare provider training.
Exome sequencing for nonimmune hydrops fetalis and clinical utility of data reanalysis
Authors: Liu Chang , Huang Yanlin , Wang Yunan , Zhang Yan , Du Li , Yu Lihua , Ding Hongke , Li Fake , Qi Yiming , Liu Yuan , Wang Xingwang , Guo Fangfang , Xiong Ying , Zhao Xin , Fang Liyuan , Geng Juan , Fu Anpeng , Wu Jing , Yin Aihua
Published: October 2024

Background

Nonimmune hydrops fetalis (NIHF) presents as life-threatening fluid collections in multiple fetal compartments and may be led by numerous etiologies.

Aim

To establish the diagnostic yield of exome sequencing for single-gene disorders in unexplained NIHF and to evaluate the clinical utility of data reanalysis.

Methods

A series of 53 unexplained cases of NIHF were enrolled, including 39 cases met a strict definition of NIHF and 14 cases with increased nuchal translucency (NT) and/or cystic hygroma in combination with other fluid collections. Trio ES from fetal samples and parental blood was performed, and clinical reports were returned by geneticists and genetic counselors. Multidisciplinary team forums were conducted for accurate diagnoses and improved patient management. The clinical follow-up assessments were conducted, and the reanalysis was performed for cases with a non-positive result.

Results

Diagnostic variants were identified in 22.6% (12/53) of the cases, and variants of potential clinical significance were detected in an additional 13.2% (7/53) of the cases. Of them, three possible diagnoses (3/41, 7.3%) were obtained during reanalysis. Notably, half of the diagnosed cases were from the group exhibiting only skin edema and increased NT and/or cystic hygroma. The diagnostic rate in this group was 42.8% (6/14), while in the classically defined NIHF group, the rate was 15.4% (6/39). The pregnancy termination and live birth rates of the cases with positive genetic testing results were found to be statistically significantly different from those with negative results (91.7% vs. 53.6% and 8.3% vs. 36.6%, P < 0.05 for both).

Conclusion

ES provides high incremental diagnostic yield for NIHF after standard-of-care testing, and reevaluating non-diagnostic exomes in light of updated knowledge can maximize diagnostic yield. Identifying the etiology of NIHF facilitates prenatal diagnosis, improves the management of NIHF cases and predicts recurrence risk in future pregnancies.
Racial diversities in lifespan bone mass: findings from the China BCL Study and US NHANES
Authors: Huang Yiwen , Ma Chuanwei , Dong Hongbo , Xiong Jingfan , Liu Li , Fan Hongmin , Shan Xinying , Chen Fangfang , Gao Liwang , Liu Junting , Wang Xi , Wang Xia , Yan Yinkun , Cheng Hong , Mi Jie
Published: October 2024

Background

Bone mass at different life stages is instrumental for developing effective, long-term osteoporosis prevention strategies.

Aim

We aimed to investigate the developmental patterns of bone mass across the entire lifespan among the Chinese population and to compare these patterns with those of different racial groups, including Whites, Blacks and Mexicans in the US population.

Design

A population-based study.

Methods

Our study analyzed data from the China Body Composition Life-course (2013–2023) Study and the United States National Health and Nutrition Examination Survey (2005–2018). We measured bone mineral content (BMC) and density (BMD) using dual-energy X-ray absorptiometry at various anatomical sites, including the whole-body (WB), lumbar spine, total hip and femoral neck.

Results

In the Chinese population, WB BMC and BMD increased rapidly during childhood and adolescence, with males and females achieving approximately 90.6% and 95.7% of their respective peak bone mass. Peak bone mass for WB, total hip and femoral neck BMC/BMD occurred generally between the ages of 21 and 30, whereas the lumbar spine BMD peak occurred approximately a decade later. After reaching the peak, a gradual bone loss was observed from ages 30 to 40, with an acceleration post age 40, especially in females. Comparative analyses indicated that Chinese individuals exhibited the lowest bone mass levels and accrual rates over their lifespan, followed successively by Whites, Mexicans and Blacks.

Conclusion

By exploring bone mass changes and racial disparities among the Chinese and US populations, this study emphasizes the need for establishing sex- and ethnic-specific public health strategies to prioritize bone health throughout the entire life course.
Association between colchicine use and adverse cardiovascular events in patients with gout: a nationwide nested case–control study
Authors: Kim Hyung Woo , Kang Minjin , Lim Hyunsun , Park Cheol Ho , Kim Jae Young , Chang Tae Ik , Han Seung Hyeok
Published: October 2024

Objective

The association between colchicine use and the primary prevention of atherosclerotic cardiovascular disease (ASCVD) remains unknown. This study aimed to explore the association between colchicine use and new development of ASCVD and ASCVD-related mortality in patients with incident gout.

Methods

This nested case–control study utilized the nationwide claims database of the Korean National Health Insurance System. Patients without a history of ASCVD who developed incident gout and were newly started on allopurinol as first-line therapy between 2011 and 2016 were initially screened. Individuals who experienced ASCVD event or ASCVD-related mortality during the follow-up period were matched with four controls for age, sex, income, residential area, co-morbidities and medications. The main exposure was colchicine use, assessed by (i) the cumulative defined daily doses (cDDDs) and (ii) the cumulative duration. For secondary analyses, the risk of ASCVD events and ASCVD-related mortality were examined separately.

Results

Overall, 9346 patients with ASCVD event or ASCVD-related mortality were matched with 35 070 controls. The patient population was predominantly male. Compared with non-users, a curvilinear relationship between higher cDDDs of colchicine and the odds of ASCVD event was observed; the odds ratios (95% CI) were 1.09 (1.04, 1.15) for <90 cDDDs, 1.20 (1.07, 1.33) for 80–179 cDDDs and 1.21 (1.09, 1.35) for ≥180 cDDDs. This association was similarly observed for ASCVD events and ASCVD-related mortality.

Conclusion

Colchicine use was associated with an increased risk of ASCVD in patients with newly diagnosed gout who did not have a prior history of ASCVD.