bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical, Swelling, and Thermal Properties of Geopolymer Mixture Containing Basic Oxygen Furnace Slag Aggregates
Authors: Tukaziban Aizhan , Shon Chang-Seon , Orynbassarov Islam , Sandybay Saken , Syzdykov Daniyar , Zhang Dichuan , Kim Jong Ryeol
Published: July 2022

Basic oxygen furnace slag (BOFS) is a waste product generated during steel production. The utilization of BOFS in construction applications is considerably limited because of its inherent characteristics leading to volumetric expansion behavior caused by the chemical reaction between free lime (f-CaO) and water. The main objective of this paper is to investigate the material properties of normal mortar and geopolymer mixtures that contain BOFS aggregates. Three different aggregates were used to compare their performance, including siliceous river sand, fresh BOFS aggregate (within 1-month age), and stockpiled (more than 5-year age) BOFS aggregate. Test methods included a compressive strength test, accelerated mortar bar expansion test, and thermal conductivity test. Test results revealed that (1) geopolymer mixtures containing BOFS aggregate had comparable compressive strength with mortar mixture with river sand, (2) geopolymer mixtures have very low volume expansion, (3) thermal conductivity of geopolymer mixtures having both river sand and BOFS was lower than normal cement mortar mixture containing river sand. Therefore, geopolymer technology seems a key solution for converting BOFS slag into valuable construction materials. Therefore, a geopolymer mixture containing BOFS aggregate can be used as an energy-saving material.
Energy Analysis of Semi-transparent Building Integrated Photovoltaic Window in Hyderabad, India Using Automated Parametric Simulations
Authors: Raihan Md Anam , Chattopadhyay Kuntal , Bhatia Aviruch , Garg Vishal , Hussain Aftab M
Published: July 2022

In recent years, semi-transparent building-integrated photovoltaics (BIPV) technology has attracted attention for its renewable energy utilization. This research aims to develop a methodology for assessing the energy-saving potential of semi-transparent photovoltaic (STPV) window, which has a complex relationship with daylighting and air conditioning (AC) electricity consumption. A case study has been developed for the composite climate of Hyderabad, India. The study examines four commercially available single and double pane STPV windows and similar non-photovoltaic windows. For evaluation, an automated parametric simulation tool was developed to compute the net electricity consumption (NEC) for a representative model building with different window systems, and several window-to-wall ratios (WWR) and orientations. The result shows benefit in adopting the STPV window system across all directions and higher optimal WWR in STPV window as compared to normal window with the same opto-thermal characteristics.
A Potential Solution for Solid Particulate Matter Reduction in Large Indoor Spaces
Authors: Alustath Husam , Daou Batoul , Elgohary Sherif , Kataw Mohammad , Kianmehr Peiman , Marzbali Mason
Published: July 2022

Air filtration is an essential process in indoor air conditioning and its physical removal of particulate matter is critical for enhancing indoor air quality, especially in arid regions including United Arab Emirates. In such regions, meeting indoor air quality standard is challenging during sporadic sandstorms when common air conditioning systems are unable to maintain indoor air quality properly. Such inability occurs either due to air infiltration through building’s fenestrations exposing indoor air to excessive particulate matter or the failure of inlet air filters after rapid clogging and high pressure drops. Such failure may be observed frequently in buildings with frequent openings such as public buildings and warehouses. Aerosolized pathogenic microorganisms, e.g., SARS-CoV-2 virus, can be modelled through air particle matter and be removed to a certain degree. In addition, the recent global pandemic raised more awareness towards the necessity of particulate matter filtration in indoor environment. Employing independent air filtration units might be a great solution for intermittent or emergency situations, when primary or additional air filtration process is required to attain proper indoor air quality. The main objective of this paper is to attempt designing, manufacturing, and utilizing an easy to set portable filtration unit and to assist buildings’ existing air conditioning systems in airborne dust particle elimination. The unit is designed and manufactured with additional feature accommodating easy installation of commercially available filters for further performance studies. The unit was equipped with all necessary performance monitoring sensors to detect key parameters such as air velocity, pressure differential, temperature, humidity, and particulate matter before and after filtration. The results revealed interesting information associated with the performance of commercially available filters and the feasibility of such independent filtration units.
Harnessing tree-ring phenotypes to disentangle gene by environment interactions and their climate dependencies in a circum-Mediterranean pine
Authors: Lombardi Erica , Shestakova Tatiana A , Santini Filippo , Resco de Dios Víctor , Voltas Jordi
Published: July 2022

Background and Aims

Understanding the genetic basis of adaptation and plasticity in trees constitutes a knowledge gap. We linked dendrochronology and genomics [single nucleotide polymorphisms (SNPs)] for a widespread conifer (Pinus halepensis Mill.) to characterize intraspecific growth differences elicited by climate.

Methods

The analysis comprised 20-year tree-ring series of 130 trees structured in 23 populations evaluated in a common garden. We tested for genotype by environment interactions (G × E) of indexed ring width (RWI) and early- to latewood ratios (ELI) using factorial regression, which describes G × E as differential gene sensitivity to climate.

Key Results

The species’ annual growth was positively influenced by winter temperature and spring moisture and negatively influenced by previous autumn precipitation and warm springs. Four and five climate factors explained 10 % (RWI) and 16 % (ELI) of population-specific interannual variability, respectively, with populations from drought-prone areas and with uneven precipitation experiencing larger growth reductions during dry vegetative periods. Furthermore, four and two SNPs explained 14 % (RWI) and 10 % (ELI) of interannual variability among trees, respectively. Two SNPs played a putative role in adaptation to climate: one identified from transcriptome sequencing of P. halepensis and another involved in response regulation to environmental stressors.

Conclusions

We highlight how tree-ring phenotypes, obtained from a common garden experiment, combined with a candidate-gene approach allow the quantification of genetic and environmental effects determining adaptation for a conifer with a large and complex genome.
A comprehensive analysis of the IEDB MHC class-I automated benchmark
Authors: Trevizani Raphael , Yan Zhen , Greenbaum Jason A , Sette Alessandro , Nielsen Morten , Peters Bjoern
Published: July 2022

In 2014, the Immune Epitope Database automated benchmark was created to compare the performance of the MHC class I binding predictors. However, this is not a straightforward process due to the different and non-standardized outputs of the methods. Additionally, some methods are more restrictive regarding the HLA alleles and epitope sizes for which they predict binding affinities, while others are more comprehensive. To address how these problems impacted the ranking of the predictors, we developed an approach to assess the reliability of different metrics. We found that using percentile-ranked results improved the stability of the ranks and allowed the predictors to be reliably ranked despite not being evaluated on the same data. We also found that given the rate new data are incorporated into the benchmark, a new method must wait for at least 4 years to be ranked against the pre-existing methods. The best-performing tools with statistically indistinguishable scores in this benchmark were NetMHCcons, NetMHCpan4.0, ANN3.4, NetMHCpan3.0 and NetMHCpan2.8. The results of this study will be used to improve the evaluation and display of benchmark performance. We highly encourage anyone working on MHC binding predictions to participate in this benchmark to get an unbiased evaluation of their predictors.
Principal Component Analysis and DoE-Based AQbD Approach to Multipurpose HPTLC Method for Synchronous Estimation of Multiple FDCs of Metformin HCl, Repaglinide, Glibenclamide and Pioglitazone HCl
Authors: Prajapati Pintu , Radadiya Khushbu , Shah Shailesh
Published: July 2022

Metformin HCl (MET) is a mostly used antidiabetic drug and several fixed-dose combinations are available in the market with other antidiabetic drugs for the treatment of insulin-independent diabetes. Numerous chromatographic methods have been reported for the estimation of multiple fixed dose combination (FDC) of MET but each FDC needs a separate and dedicated chromatographic method for analysis. No chromatographic method has been reported yet in the literature which promotes synchronous estimation of multiple FDCs of MET to minimize organic solvent consumption, time and cost of analysis. Hence, the multipurpose-high performance thin layer chromatography (HPTLC) method was developed for the synchronous estimation of FDCs of MET by the implementation of an enhanced analytical quality by design approach. Principal component analysis was applied for the identification of critical method risk parameters. Box–Behnken design was applied for response surface analysis. The method operable design ranges was navigated and the control strategy was framed. The developed method was applied for the analysis of multiple FDCs of metformin. The developed method can synchronously analyze multiple FDCs of MET which required several chromatographic methods. Hence, the present method is multipurpose-HPTLC for the synchronous estimation of multiple FDCs of MET which required minimum organic solvent, time and cost of analysis.
Reduction and Hydroxylation Metabolites of Mequindox in Holothurian Analysis by Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry
Authors: Li Yonggang , Mao Xin , Jiang Lisheng , Liu Huihui , Nie Xiaoming , Liu Xiaohong , Kong Fang , Luo Ping , Li Yanshen
Published: July 2022

This research proposed and validated an LC-MSMS method for five reduction and hydroxylation metabolites of Mequindox (MEQ) as well as the precursor in holothurian samples. Specially, three hydroxylation metabolites (2-isoethanol-mequindox, M3, 2-isoethanol-1-desoxymequindox, M4 and 2-isoethanol-4-desoxymequindox, M5) are novel for analysis. Target compounds were extracted with methanol and ethyl acetate in turn without any complicated acidolysis, alkaline hydrolysis or enzymolysis steps. Samples were further purified with C18 solid-phase extraction cartridges for LC-MSMS analysis. Mean recoveries in spiked samples ranged from 81 to 107% with intra-day relative standard deviation (RSD) and inter-day RSD <11.2 and 9.9%, respectively. Limit of detection was determined based on signal-to-noise ratio ≥3 ranged from 0.16 to 2.11 μg kg−1 for each target. The validated protocol was successfully applied for commercial holothurian samples with a positive rate at 13.3%. And concentrations of hydroxylation metabolites were higher than reduction metabolites and precursor MEQ in positive samples.
Increased Stroke Risk Following Herpes Zoster Infection and Protection With Zoster Vaccine
Authors: Parameswaran Ganapathi Iyer , Wattengel Bethany A , Chua Hubert C , Swiderek Jessica , Fuchs Tom , Carter Michael T , Goode Laura , Doyle Kathleen , Mergenhagen Kari A
Published: July 2022

Background

Studies evaluating stroke following varicella zoster virus (VZV) infection are limited, and the utility of zoster vaccination against this phenomenon is unclear. This study aimed to determine the risk of stroke 30 days following zoster infection and to evaluate the impact of zoster vaccinations on the risk of stroke in VZV-infected patients.

Methods

This retrospective case-control study was conducted from January 2010 to January 2020 utilizing nationwide patient data retrieved from the Veterans Affairs’ Corporate Data Warehouse.

Results

A total of 2 165 505 patients ≥18 years of age who received care at a Veterans Affairs facility were included in the study, of whom 71 911 had a history of zoster infection. Zoster patients were found to have 1.9 times increased likelihood of developing a stroke within 30 days following infection (odds ratio [OR], 1.93 [95% confidence interval {CI}, 1.57–2.4]; P < .0001). A decreased risk of stroke was seen in patients who received the recombinant zoster vaccine (OR, 0.57 [95% CI, .46–.72]; P < .0001) or the live zoster vaccine (OR, 0.77 [95% CI, .65–.91]; P = .002).

Conclusions

Patients had a significantly higher risk of stroke within the first month following recent herpes zoster infection. Receipt of at least 1 zoster vaccination was found to mitigate this increased risk. Vaccination may therefore be viewed as a protective tool against the risk of neurologic postinfection sequelae.
Listeria monocytogenes Illness and Deaths Associated With Ongoing Contamination of a Multiregional Brand of Ice Cream Products, United States, 2010–2015
Authors: Conrad Amanda R , Tubach Sheri , Cantu Venessa , Webb Lindsey Martin , Stroika Steven , Moris Steve , Davis Megan , Hunt D Charles , Bradley Kristy K , Kucerova Zuzana , Strain Errol , Doyle Matthew , Fields Angela , Neil Karen P , Gould L Hannah , Jackson Kelly A , Wise Matthew E , Griffin Patricia M , Jackson Brendan R
Published: July 2022

Background

Frozen foods have rarely been linked to Listeria monocytogenes illness. We describe an outbreak investigation prompted by both hospital clustering of illnesses and product testing.

Methods

We identified outbreak-associated listeriosis cases using whole-genome sequencing (WGS), product testing results, and epidemiologic linkage to cases in the same Kansas hospital. We reviewed hospital medical and dietary records, product invoices, and molecular subtyping results. Federal and state officials tested product and environmental samples for L. monocytogenes.

Results

Kansas officials were investigating 5 cases of listeriosis at a single hospital when, simultaneously, unrelated sampling for a study in South Carolina identified L. monocytogenes in Company A ice cream products made in Texas. Isolates from 4 patients and Company A products were closely related by WGS, and the 4 patients with known exposures had consumed milkshakes made with Company A ice cream while hospitalized. Further testing identified L. monocytogenes in ice cream produced in a second Company A production facility in Oklahoma; these isolates were closely related by WGS to those from 5 patients in 3 other states. These 10 illnesses, involving 3 deaths, occurred from 2010 through 2015. Company A ultimately recalled all products.

Conclusions

In this US outbreak of listeriosis linked to a widely distributed brand of ice cream, WGS and product sampling helped link cases spanning 5 years to 2 production facilities, indicating longstanding contamination. Comprehensive sanitation controls and environmental and product testing for L. monocytogenes with regulatory oversight should be implemented for ice cream production.
Antibody and T-Cell Responses 6 Months After Coronavirus Disease 2019 Messenger RNA-1273 Vaccination in Patients With Chronic Kidney Disease, on Dialysis, or Living With a Kidney Transplant
Authors: Sanders Jan-Stephan F , Messchendorp A Lianne , de Vries Rory D , Baan Carla C , van Baarle Debbie , van Binnendijk Rob , Diavatopoulos Dimitri A , Geers Daryl , Schmitz Katharina S , GeurtsvanKessel Corine H , den Hartog Gerco , Kho Marcia M L , Koopmans Marion P G , van der Molen Renate G , Remmerswaal Ester B M , Rots Nynke , Gansevoort Ron T , Bemelman Frederike J , Hilbrands Luuk B , Reinders Marlies E J ,   the VACcination Immune Response Study (RECOVAC) Collaborators, Abrahams Alferso C , Baas Marije C , Bouwmans Pim , ten Dam Marc A G J , Gommers Lennert , Frölke Sophie C , Standaar Dorien , van der Heiden Marieke , Imhof Celine , Adema Yvonne M R , Malahe Reshwan K , Boer-Verschragen Marieken J , Mattheussens Wouter B , Philipsen Ria , van Mourik Djenolan , Bogers Susanne , van Dijk Laura L A , Hemmelder Marc H , de Vries Aiko P J
Published: July 2022

Background

The immune response to COVID-19 vaccination is inferior in kidney transplant recipients (KTRs) and to a lesser extent in patients on dialysis or with chronic kidney disease (CKD). We assessed the immune response 6 months after mRNA-1273 vaccination in kidney patients and compared this to controls.

Methods

A total of 152 participants with CKD stages G4/5 (eGFR <30 mL/min/1.73 m2), 145 participants on dialysis, 267 KTRs, and 181 controls were included. SARS-CoV-2 Spike S1 specific IgG antibodies were measured using fluorescent bead-based multiplex-immunoassay, neutralizing antibodies to ancestral, Delta, and Omicron (BA.1) variants by plaque reduction, and T-cell responses by interferon-γ release assay.

Results

At 6 months after vaccination, S1-specific antibodies were detected in 100% of controls, 98.7% of CKD G4/5 patients, 95.1% of dialysis patients, and 56.6% of KTRs. These figures were comparable to the response rates at 28 days, but antibody levels waned significantly. Neutralization of the ancestral and Delta variants was detected in most participants, whereas neutralization of Omicron was mostly absent. S-specific T-cell responses were detected at 6 months in 75.0% of controls, 69.4% of CKD G4/5 patients, 52.6% of dialysis patients, and 12.9% of KTRs. T-cell responses at 6 months were significantly lower than responses at 28 days.

Conclusions

Although seropositivity rates at 6 months were comparable to rates at 28 days after vaccination, significantly decreased antibody levels and T-cell responses were observed. The combination of low antibody levels, reduced T-cell responses, and absent neutralization of the newly emerging variants indicates the need for additional boosts or alternative vaccination strategies in KTRs.

Clinical Trials Registration

NCT04741386.
Risk Factors for Mortality Among Children Younger Than Age 5 Years With Severe Diarrhea in Low- and Middle-income Countries: Findings From the World Health Organization-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks
Authors: Hartman Rachel M , Cohen Adam L , Antoni Sebastien , Mwenda Jason , Weldegebriel Goitom , Biey Joseph , Shaba Keith , de Oliveira Lucia , Rey Gloria , Ortiz Claudia , Tereza Maria , Fahmy Kamal , Ghoniem Amany , Ashmony Hossam , Videbaek Dovile , Singh Simarjit , Tondo Emmanuel , Sharifuzzaman Mohammed , Liyanage Jayantha , Batmunkh Nyambat , Grabovac Varja , Logronio Josephine , Serhan Fatima , Nakamura Tomoka
Published: July 2022

Background

Diarrhea is the second leading cause of death in children younger than 5 years of age globally. The burden of diarrheal mortality is concentrated in low-resource settings. Little is known about the risk factors for childhood death from diarrheal disease in low- and middle-income countries.

Methods

Data from the World Health Organization (WHO)-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks, which are composed of active, sentinel, hospital-based surveillance sites, were analyzed to assess mortality in children <5 years of age who were hospitalized with diarrhea between 2008 and 2018. Case fatality risks were calculated, and multivariable logistic regression was performed to identify risk factors for mortality.

Results

This analysis comprises 234 781 cases, including 1219 deaths, across 57 countries. The overall case fatality risk was found to be 0.5%. Risk factors for death in the multivariable analysis included younger age (for <6 months compared with older ages, odds ratio [OR] = 3.54; 95% confidence interval [CI], 2.81–4.50), female sex (OR = 1.18; 95% CI, 1.06–1.81), presenting with persistent diarrhea (OR = 1.91; 95% CI, 1.01–3.25), no vomiting (OR = 1.13; 95% CI, .98–1.30), severe dehydration (OR = 3.79; 95% CI, 3.01–4.83), and being negative for rotavirus on an enzyme-linked immunosorbent assay test (OR = 2.29; 95% CI, 1.92–2.74). Cases from the African Region had the highest odds of death compared with other WHO regions (OR = 130.62 comparing the African Region with the European Region; 95% CI, 55.72–422.73), whereas cases from the European Region had the lowest odds of death.

Conclusions

Our findings support known risk factors for childhood diarrheal mortality and highlight the need for interventions to address dehydration and rotavirus-negative diarrheal infections.
Curation of a reference database of COI sequences for insect identification through DNA metabarcoding: COins
Authors: Magoga Giulia , Forni Giobbe , Brunetti Matteo , Meral Aycan , Spada Alberto , De Biase Alessio , Montagna Matteo
Published: July 2022

DNA metabarcoding is a widespread approach for the molecular identification of organisms. While the associated wet-lab and data processing procedures are well established and highly efficient, the reference databases for taxonomic assignment can be implemented to improve the accuracy of identifications. Insects are among the organisms for which DNA-based identification is most commonly used; yet, a DNA-metabarcoding reference database specifically curated for their species identification using software requiring local databases is lacking. Here, we present COins, a database of 5’ region cytochrome c oxidase subunit I sequences (COI-5P) of insects that includes over 532 000 representative sequences of >106 000 species specifically formatted for the QIIME2 software platform. Through a combination of automated and manually curated steps, we developed this database starting from all COI sequences available in the Barcode of Life Data System for insects, focusing on sequences that comply with several standards, including a species-level identification. COins was validated on previously published DNA-metabarcoding sequences data (bulk samples from Malaise traps) and its efficiency compared with other publicly available reference databases (not specific for insects). COins can allow an increase of up to 30% of species-level identifications and thus can represent a valuable resource for the taxonomic assignment of insects’ DNA-metabarcoding data, especially when species-level identification is needed https://doi.org/10.6084/m9.figshare.19130465.v1.
Infecting the Mind: Establishing Responsibility for Transboundary Disinformation
Authors: Lahmann Henning
Published: July 2022

This article examines the legal issues concerning the establishment of responsibility for an internationally wrongful act in the context of transboundary disinformation. In light of the unprecedented surge of potentially dangerous health disinformation throughout the COVID-19 pandemic, there is growing consensus among academics and states that influence campaigns that utilize false or misleading information may qualify as a violation of international law, amounting to a prohibited coercive intervention, a breach of the target state’s territorial inviolability or independence of state powers or, in extreme cases, even a use of force. However, the aspects of attributing the dissemination of disinformation to a state and of demonstrating a causal nexus between disinformation and effect that are necessary for international responsibility to arise have not been sufficiently addressed in the literature. This article analyses the challenges that contemporary forms of digital disinformation create for proving attribution pursuant to the customary rules of state responsibility as well as the issue of causation. In doing so, it investigates the content of the primary rules for clues pertaining to the necessary causal nexus and assesses different standards of causation employed in international and domestic law.
A Citation Review of 83 Dissemination and Implementation Theories, Models, or Frameworks Utilized in U.S.-Based Aging Research
Authors: Sullivan Jennifer L , Montano Anna Rae L , Hughes Jaime M , Davila Heather W , O’Malley Kelly A , Engle Ryann L , Hawley Chelsea E , Shin Marlena H , Smith Jason G , Pimentel Camilla B
Published: July 2022

Background and Objectives

Dissemination-implementation.org outlines 110 theories, models, and frameworks (TMFs): we conducted a citation analysis on 83 TMFs, searching Web of Science and PubMed databases.

Research Design and Methods

Search terms were broad and included “aging,” “older,” “elderly,” and “geriatric.” We extracted each TMF in identified articles from inception through January 28, 2022. Included articles must have used a TMF in research or quality improvement work directly linked to older adults within the United States.

Results

We reviewed 2,681 articles of which 295 articles cited at least one of 56 TMFs. Five TMFs represented 50% of the citations: Reach, Effectiveness, Adoption, Implementation, and Maintenance 1.0, Consolidated Framework for Implementation Research, Greenhalgh Diffusion of Innovation in Service Organizations, Quality Enhancement Research Initiative, Community-Based Participatory Research, and Promoting Action on Research Implementation in Health Services. TMF application varied and there was a steady increase in TMF citations over time, with a 2- to 3-fold increase in citations in 2020–2021. We identified that only 41% of TMF use was meaningful.

Discussion and Implications

Our results suggest TMF utilization is increasing in aging research, but there is a need to more meaningful utilize TMFs. As the population of older adults continues to grow, there will be increasing demand for effective evidence-based practices and models of care to be quickly and effectively translated into routine care. Use of TMFs is critical to building such evidence and to identifying and evaluating methods to support this translation.
Implementing CAPABLE With Care Partners Through an Area Agency on Aging: Identifying Barriers and Facilitators Using the Consolidated Framework for Implementation Research
Authors: Toto Pamela E , Alchin Tucker , Yanes Caylee , Park Seeun , Fields Beth E
Published: July 2022

Background and Objectives

Community Aging in Place, Advancing Better Living for Elders (CAPABLE) is an evidence-based intervention to promote aging in place. Although CAPABLE has been implemented in more than 40 community sites, wide variation in implementation exists. Guided by the Consolidated Framework for Implementation Research (CFIR), this study sought to determine key barriers and facilitators that may influence CAPABLE implementation with older adult and care partner dyads through an area agency on aging (AAA).

Research Design and Methods

A formative evaluation was completed using qualitative data from the pilot of a Hybrid Trial Type 1 study implementing CAPABLE in an AAA. Multiple sources of data were collected, including 2 focus groups, field notes, a tracking log, and meetings with CAPABLE interventionists. Data were analyzed using a framework method and validated through a negative case analysis approach in NVivo 12 Pro.

Results

Fourteen dyads enrolled in the pilot and 6 completed the CAPABLE intervention. Key themes aligned with 10 constructs from 5 domains of the CFIR. Facilitators included adaptability of the intervention, cost, networks and communication, and knowledge and belief of individuals. Barriers included intervention complexity, client needs and resources, and executing the planned process.

Discussion and Implications

Results enhance understanding of contextual factors that can influence the implementation of CAPABLE with care partners. Strategies to overcome barriers include simplifying recruitment materials and targeting older adults with recent onset of disability. The CFIR is a valuable resource for planning and evaluation of the implementation of evidence-based interventions to promote aging in place.
Puzzling large-scale polarization in the galaxy cluster Abell 523
Authors: Vacca Valentina , Govoni Federica , Murgia Matteo , Perley Richard A , Feretti Luigina , Giovannini Gabriele , Carretti Ettore , Gastaldello Fabio , Cova Filippo , Marchegiani Paolo , Battistelli Elia , Boschin Walter , Enßlin Torsten A , Girardi Marisa , Loi Francesca , Radiconi Federico
Published: July 2022

Large-scale magnetic fields reveal themselves through diffuse synchrotron sources observed in galaxy clusters such as radio halos. Total intensity filaments of these sources have been observed in polarization as well, but only in three radio halos out of about 100 currently known. In this paper we analyse new polarimetric Very Large Array data of the diffuse emission in the galaxy cluster Abell 523 in the frequency range 1–2 GHz. We find for the first time evidence of polarized emission on scales of ∼2.5 Mpc. The total intensity emission is observed only in the central part of the source, likely due to observational limitations. To look for total intensity emission beyond the central region, we combine these data with single-dish observations from the Sardinia Radio Telescope and we compare them with multifrequency total intensity observations obtained with different instruments, including the LOw Frequency ARray and the Murchison Widefield Array. By analysing the rotation measure properties of the system and utilizing numerical simulations, we infer that this polarized emission is associated with filaments of the radio halo located in the outskirts of the system, in the peripheral region closest to the observer.
Evolution of circumstellar discs in young star-forming regions
Authors: Concha-Ramírez Francisca , Wilhelm Martijn J C , Portegies Zwart Simon
Published: July 2022

The evolution of circumstellar discs is influenced by their surroundings. The relevant processes include external photoevaporation due to nearby stars and dynamical truncations. The impact of these processes on disc populations depends on the star-formation history and on the dynamical evolution of the region. Since star-formation history and the phase-space characteristics of the stars are important for the evolution of the discs, we start simulating the evolution of the star cluster with the results of molecular cloud collapse simulations. In the simulation, we form stars with circumstellar discs, which can be affected by different processes. Our models account for the viscous evolution of the discs, internal and external photoevaporation of gas, external photoevaporation of dust, and dynamical truncations. All these processes are resolved together with the dynamical evolution of the cluster, and the evolution of the stars. An extended period of star formation, lasting for at least 2 Myr, results in some discs being formed late. These late-formed discs have a better chance of survival because the cluster gradually expands with time, and a lower local stellar density reduces the effects of photoevaporation and dynamical truncation. Late formed discs can then be present in regions of high UV radiation, solving the proplyd lifetime problem. We also find a considerable fraction of discs that lose their gas content but remain sufficiently rich in solids to be able to form a rocky planetary system.
Formation of dust rings and gaps in non-ideal MHD discs through meridional gas flows
Authors: Hu Xiao , Li Zhi-Yun , Zhu Zhaohuan , Yang Chao-Chin
Published: July 2022

Rings and gaps are commonly observed in the dust continuum emission of young stellar discs. Previous studies have shown that substructures naturally develop in the weakly ionized gas of magnetized, non-ideal MHD discs. The gas rings are expected to trap large mm/cm-sized grains through pressure gradient-induced radial dust–gas drift. Using 2D (axisymmetric) MHD simulations that include ambipolar diffusion and dust grains of three representative sizes (1 mm, 3.3 mm, and 1 cm), we show that the grains indeed tend to drift radially relative to the gas towards the centres of the gas rings, at speeds much higher than in a smooth disc because of steeper pressure gradients. However, their spatial distribution is primarily controlled by meridional gas motions, which are typically much faster than the dust–gas drift. In particular, the grains that have settled near the mid-plane are carried rapidly inwards by a fast accretion stream to the inner edges of the gas rings, where they are lifted up by the gas flows diverted away from the mid-plane by a strong poloidal magnetic field. The flow pattern in our simulation provides an attractive explanation for the meridional flows recently inferred in HD 163296 and other discs, including both ‘collapsing’ regions where the gas near the disc surface converges towards the mid-plane and a disc wind. Our study highlights the prevalence of the potentially observable meridional flows associated with the gas substructure formation in non-ideal MHD discs and their crucial role in generating rings and gaps in dust.
Simulating radio synchrotron emission in star-forming galaxies: small-scale magnetic dynamo and the origin of the far-infrared–radio correlation
Authors: Pfrommer Christoph , Werhahn Maria , Pakmor Rüdiger , Girichidis Philipp , Simpson Christine M
Published: July 2022

In star-forming galaxies, the far-infrared (FIR) and radio-continuum luminosities obey a tight empirical relation over a large range of star-formation rates (SFR). To understand the physics, we examine magnetohydrodynamic galaxy simulations, which follow the genesis of cosmic ray (CR) protons at supernovae and their advective and anisotropic diffusive transport. We show that gravitational collapse of the proto-galaxy generates a corrugated accretion shock, which injects turbulence and drives a small-scale magnetic dynamo. As the shock propagates outwards and the associated turbulence decays, the large velocity shear between the supersonically rotating cool disc with respect to the (partially) pressure-supported hot circumgalactic medium excites Kelvin–Helmholtz surface and body modes. Those interact non-linearly, inject additional turbulence and continuously drive multiple small-scale dynamos, which exponentially amplify weak seed magnetic fields. After saturation at small scales, they grow in scale to reach equipartition with thermal and CR energies in Milky Way-mass galaxies. In small galaxies, the magnetic energy saturates at the turbulent energy while it fails to reach equipartition with thermal and CR energies. We solve for steady-state spectra of CR protons, secondary electrons/positrons from hadronic CR-proton interactions with the interstellar medium, and primary shock-accelerated electrons at supernovae. The radio-synchrotron emission is dominated by primary electrons, irradiates the magnetized disc and bulge of our simulated Milky Way-mass galaxy and weakly traces bubble-shaped magnetically loaded outflows. Our star-forming and star-bursting galaxies with saturated magnetic fields match the global FIR-radio correlation (FRC) across four orders of magnitude. Its intrinsic scatter arises due to (i) different magnetic saturation levels that result from different seed magnetic fields, (ii) different radio synchrotron luminosities for different specific SFRs at fixed SFR, and (iii) a varying radio intensity with galactic inclination. In agreement with observations, several 100-pc-sized regions within star-forming galaxies also obey the FRC, while the centres of starbursts substantially exceed the FRC.
Spectral and timing analysis of BeXRB eRASSU J050810.4–660653 recently discovered in the Large Magellanic Cloud (LMC)
Authors: Ghising Manoj , Tobrej Mohammed , Tamang Ruchi , Rai Binay , Paul Bikash Chandra
Published: July 2022

We have studied the Be/X-ray binary (BeXRB) pulsar eRASSU J050810.4–660653 recently discovered in the Large Magellanic Cloud (LMC). Timing and spectral features of the source have been discussed in detail using NuSTAR and XMM–Newton observations. Coherent pulsation of the source was detected at ∼40.578 ± 0.001 s using NuSTAR observation. We analysed pulse profiles of the source in different energy bands using NuSTAR and XMM–Newton data. The pulse-profile evolved with time but was generally suggestive of a pencil-beam dominated pattern, which combined with the measured luminosity, indicates that the source may be accreting in the sub-critical regime. The pulse fraction follows a linearly increasing trend with photon energy and is anticorrelated with luminosity. In the 1-yr interval between the XMM and NuSTAR observations, the pulse period shortened by 0.021 s which could be consistent with spin-up or orbital Doppler effect. The average flux of the source in (3–50) keV energy range is found to be $\sim 5.56 \times 10^{-11}\, {\rm erg}\, {\rm cm}^{-2}\, \mathrm{s}^{-1}$ and the corresponding luminosity is $\sim 1.66 \times 10^{37}\, {\rm erg}\, \mathrm{s}^{-1}$. The variation of spectral parameters with pulse phase is studied using phase resolved spectroscopy which reveals that the observed photon index becomes harder with increasing flux.
Centrifugal barrier and super-Keplerian rotation in protostellar disc formation
Authors: Jones Dylan C , Lam Ka Ho , Li Zhi-Yun , Tu Yisheng
Published: July 2022

With the advent of ALMA, it is now possible to observationally constrain how discs form around deeply embedded protostars. In particular, the recent ALMA C3H2 line observations of the nearby protostar L1527 have been interpreted as evidence for the so-called ‘centrifugal barrier,’ where the protostellar envelope infall is gradually decelerated to a stop by the centrifugal force in a region of super-Keplerian rotation. To test the concept of centrifugal barrier, which was originally based on angular momentum conserving-collapse of a rotating test particle around a fixed point mass, we carry out simple axisymmetric hydrodynamic simulations of protostellar disc formation including a minimum set of ingredients: self-gravity, rotation, and a prescribed viscosity that enables the disc to accrete. We find that a super-Keplerian region can indeed exist when the viscosity is relatively large but, unlike the classic picture of centrifugal barrier, the infalling envelope material is not decelerated solely by the centrifugal force. The region has more specific angular momentum than its surrounding envelope material, which points to an origin in outward angular momentum transport in the disc (subject to the constraint of disc expansion by the infalling envelope), rather than the spin-up of the envelope material envisioned in the classic picture as it falls closer to the centre in order to conserve angular momentum. For smaller viscosities, the super-Keplerian rotation is weaker or non-existing. We conclude that, despite the existence of super-Keplerian rotation in some parameter regime, the classic picture of centrifugal barrier is not supported by our simulations.
A COMPREHENSIVE STUDY ON INDOOR RADON, THORON AND THEIR PROGENY LEVEL IN DIMAPUR DISTRICT OF NAGALAND, INDIA
Authors: Jamir Supongtoshi , Sahoo B K , Mishra Rosaline , Sinha Dipak
Published: July 2022

Indoor radon (222Rn), thoron (220Rn) and their progeny concentrations were detected in several homes in Dimapur district, Nagaland, utilizing Direct Radon and Thoron progeny sensors based on solid-state Nuclear Track Detectors (Type-2 film) and pinhole type radon-thoron discriminating dosemeters. For three separate seasons, the annual inhalation dose has been determined in 80 residences in the research regions. The residences were chosen to have various types of housing, such as concrete, semi-wood/bamboo and bamboo, with varying levels of ventilation that contribute to indoor 222Rn, 220Rn and their progeny. The inhalation dose in the survey area lies between 0.33 and 3.04 mSvy−1 and is within the reference value as suggested by ICRP, 2018.
Intra-annual tree-ring δ18O and δ13C reveal a trade-off between isotopic source and humidity in moist environments
Authors: Xu Guobao , Liu Xiaohong , Hu Jia , Dorado-Liñán Isabel , Gagen Mary , Szejner Paul , Chen Tuo , Trouet Valerie
Published: July 2022

Tree-ring intra-annual stable isotopes (δ13C and δ18O) are powerful tools for revealing plant ecophysiological responses to climatic extremes. We analyzed interannual and fine-scale intra-annual variability of tree-ring δ13C and δ18O in Chinese red pine (Pinus massoniana) from southeastern China to explore environmental drivers and potential trade-offs between the main physiological controls. We show that wet season relative humidity (May–October RH) drove interannual variability of δ18O and intra-annual variability of tree-ring δ18O. It also drove intra-annual variability of tree-ring δ13C, whereas interannual variability was mainly controlled by February–May temperature and September–October RH. Furthermore, intra-annual tree-ring δ18O variability was larger during wet years compared with dry years, whereas δ13C variability was lower during wet years compared with dry years. As a result of these differences in intra-annual variability amplitude, process-based models (we used the Roden model for δ18O and the Farquhar model for δ13C) captured the intra-annual δ18O pattern better in wet years compared with dry years, whereas intra-annual δ13C pattern was better simulated in dry years compared with wet years. This result suggests a potential asymmetric bias in process-based models in capturing the interplay of the different mechanistic processes (i.e., isotopic source and leaf-level enrichment) operating in dry versus wet years. We therefore propose an intra-annual conceptual model considering a dynamic trade-off between the isotopic source and leaf-level enrichment in different tree-ring parts to understand how climate and ecophysiological processes drive intra-annual tree-ring stable isotopic variability under humid climate conditions.
Effect of Concomitant Tuberculosis Infection on COVID-19 Disease in Children: A Matched, Retrospective Cohort Study
Authors: Mathur Surendra Bahadur , Saxena Romit , Pallavi Pallavi , Jain Rahul , Mishra Devendra , Jhamb Urmila
Published: July 2022

Background

Coronavirus disease 2019 (COVID-19) has had devastating effects on the health of millions globally. Patients with tuberculosis (TB) are a vulnerable population. There is paucity of data to assess association between the 2 diseases in Pediatric population.

Objective

To elucidate the effect of concomitant TB on clinical course of pediatric COVID-19 disease.

Methods

Retrospective matched cohort study was conducted at dedicated tertiary COVID-19 hospital in India. All consecutive patients aged <18 y admitted with COVID-19 were line listed. Patients with current or recently diagnosed TB were included. Consecutive age and sex matched COVID-19 patients with no history of TB were included as controls. Medical records were retrieved, clinical data entered in pre-determined proforma.

Results

During study period, 327 pediatric COVID-19 patients were admitted. Study group included 17 patients with TB. These patients, tended to be referred from other hospitals, be sicker, had lower SpO2 at arrival and higher severity of COVID-19 as compared to controls (All P < 0.05). They required more mechanical ventilation, had longer length of stay and worse outcome.

Conclusion

COVID-19 may secondarily affect and modify the course of TB in children. Given the high case fatality rate in this association and potentially treatable nature of TB, attention of the policy makers is drawn to this.

Name of IEC committee

Maulana Azad Medical College and Associated Hospital Institutional Ethics Committee. IEC no: F.1/IEC/MAMC/(80/8/2020/No274). Dated 9 November 2020.

Trial registration

CTRI/2021/02/031197 [Registered on: 10 February 2021].
Emergency Department Visits After Outpatient Spine Surgery
Authors: Durand Wesley M. , Badin Daniel , Ortiz-Babilonia Carlos , Musharbash Farah N. , Raad Micheal , Jain Amit
Published: July 2022

Study Design.

A retrospective study.

Objective.

This study sought to characterize the incidence and timing of postoperative emergency department (ED) visits after common outpatient spinal surgeries performed at ambulatory surgery centers (ASCs) and at hospital outpatient departments (HOPDs).

Summary of Background Data.

Outpatient spine surgery has markedly grown in popularity over the past decade. The incidence of ED visits after outpatient spine surgery is not well established.

Methods.

This study was a retrospective analysis of a large commercial claims insurance database of patients 65 years old and below. Patients who underwent single-level anterior cervical discectomy and fusion, laminectomy, and microdiscectomy were identified. Incidence, timing, and diagnoses associated with ED visits within the postoperative global period (90 d) after surgery were assessed.

Results.

In total, 202,202 patients received outpatient spine surgery (19.1% in ASC vs. 80.9% in HOPD). Collectively, there were 22,198 ED visits during the 90-day postoperative period. Approximately 9.0% of patients had at least 1 ED visit, and the incidence varied by procedure: anterior cervical discectomy and fusion 9.9%, laminectomy 9.5%, and microdiscectomy 8.5% (P<0.0001). After adjusting for age, sex, and comorbidity index, the odds of at least 1 ED visit were higher among patients who received surgery at HOPD versus ASC for all 3 procedures. The majority (56.1%) ED visits occurred during the first month postoperatively; 30.8% (n=6841) occurred within the first week postoperatively, and 10.7% (n=2370) occurred on the same day as the surgery. Postoperative pain was the most common reason for ED visits.

Conclusions.

Among commercially insured patients who received outpatient spine surgery, the incidence of ED visits during the 90-day postoperative period was ~9%. Our results indicate opportunities for improved postoperative care planning after outpatient spinal surgery.
Surgical Management of Type II Displaced Dens Fractures Improves One-Year Mortality in Elderly Patients
Authors: Smith Spencer , Somogyi Rita , Lin Clifford , Yoo Jung
Published: July 2022

Study Design.

Retrospective cross-sectional analysis of US national data collected by PearlDiver Inc. database.

Objective.

To determine the rates of surgical/non-surgical treatments and associated one-year mortality for displaced type II dens fractures without neurologic deficit.

Summary of Background Data.

Existing literature on dens fractures includes small series of patients, with highly variable surgical rates. These studies contain insufficient data to determine the benefits of surgical or non-surgical treatment as surgeon bias in treatment and selection of patients have significant effects on the results.

Methods.

Displaced type II dens fractures and upper cervical surgeries were identified using their respective ICD-10 diagnosis and CPT codes. Inclusion criteria included patients older than 65, diagnosed with a displaced type II dens fracture, absent neurological damage, during the years 2015-2018. Age, gender, ICD-10 diagnosis codes, CPT codes, displacement type, and Elixhauser Comorbidity Index scores were obtained through the PearlDiver database. Patient related variables and one-year mortality associated with surgical versus non-surgical treatment were compared using univariate chi-squared analysis, odds ratios, and multivariate logistic regression analysis.

Results.

Among the 5,300 patients who met our inclusion criteria, 59% (n=3,108) were female, the mean age was 76.6 (±3.9) years old, and the average ECI was 7.1 (±4.0). Only 8.3% (n=437) had surgical treatment for the displaced dens fracture. Multivariate logistic regression analysis for one-year mortality showed surgery was associated with decreased one-year mortality in all patients (z=−6.26; P<0.001), patients between the ages of 65 and 74 (z=−2.53; P=0.012), and patients over the age of 75 (z=−5.81; P<0.001).

Conclusion.

Despite surgery improving survival in elderly patients with type II dens fractures, surgical management is rarely pursued. Factors that independently increase the likelihood of surgery include younger age, male gender, and posterior displacement