bluuebunny/crossref_metadata_2025 huggingface dataset:
Navigating the landscape of e-commerce: thematic clusters, intellectual turning points, and burst patterns in online reputation management
Authors: Lopez-Lopez David , Plaza-Navas Miquel Angel , Torres-Pruñonosa Jose , Martinez Luis F.
Published: September 2024

Recognizing the challenges identified in the vast literature exploring the intellectual landscape of Online Reputation Management (ORM) in the realm of e-commerce, this study performs a quantitative bibliometric analysis, specifically a co-citation analysis using CiteSpace software, to find thematic clusters in a sample of 1136 papers containing 48,385 cited references. This is the first co-citation analysis of ORM literature that cluster the intellectual structure and identifies both the intellectual turning points and burst papers. The results reveal 14 distinct co-citation clusters, each representing a unique thematic structure. An in-depth analysis further characterizes the clusters, ranging from the impact of online reputation on the hospitality industry to frameworks explaining trust formation in e-commerce. Additionally, the study identifies intellectual turning points by assessing betweenness centrality, highlighting four seminal papers that have strongly influenced the field. Furthermore, burst detection analysis uncovers the temporal dynamics of research trends, showcasing the enduring influence of certain clusters and the transient nature of burst patterns. The novelty and importance of the results from the detailed burst detection analysis lie in identifying a significant evolution in research focus over time. Initially, research was concentrated on foundational studies and understanding customer behavior. It then shifted towards practical applications in specific industries, particularly in hospitality and online reviews. In recent years, the emphasis has been on integrating ORM into broader business strategies, especially within e-commerce and the collaborative economy. This research not only contributes to a deeper understanding of ORM, but also serves as a valuable guide for researchers, practitioners, and policymakers in the evolving landscape of online reputation in e-commerce.
From cortisol-producing adrenal adenoma to atrial myxoma, through nivolumab-induced hypophysitis: a complicated case report of Carney Complex
Authors: Di Gioia Ludovico , Dambrosio Giovanni , Cignarelli Angelo , Natalicchio Annalisa , Perrini Sebastio , Laviola Luigi , Giorgino Francesco , Sorice Gian Pio
Published: September 2024

Purpose

Carney complex (CNC) is a rare, autosomal dominant syndrome, most commonly caused by PRKAR1A gene mutations and characterized by pigmented skin and mucosal changes with multiple endocrine and non-endocrine tumours. This case report highlights the diagnostic challenges associated with CNC in a patient with multiple neoplasms and a complex medical history, including cortisol-producing adrenal adenoma, breast cancer, melanoma, and atrial myxoma.

Methods

We report the case of a 41-year-old woman with a medical history of left adrenalectomy for cortisol producing adenoma (2005) with no sign of adrenal insufficiency at follow-up, right mastectomy for BRCA1/2 negative carcinoma (2013) and left parotid BRAF-V600E wild-type melanoma (2019), treated with nivolumab adjuvant therapy. In August 2019, following the fifth nivolumab administration, the patient developed central hypocortisolism due to iatrogenic hypophysitis, confirmed by brain MRI and properly treated with oral hydrocortisone. Nivolumab was discontinued due to the patient’s decision. In October 2020 and April 2021, the patient had ischaemic strokes, requiring systemic thrombolysis. Echocardiographic examination then revealed a left atrial mass, with histological finding of myxoma.

Results

Given the rarity of this neoplasm and the suspicion of a syndromic disorder, a genetic evaluation was conducted, which confirmed a PRKAR1A gene mutation and the diagnosis of Carney complex.

Conclusion

This case illustrates the diagnostic challenges in CNC, especially in patients with multiple tumourous manifestations and a wide spectrum of life-threatening clinical presentations. It underscores the importance of a multidisciplinary approach to diagnose and manage rare diseases, improving patient outcomes through timely genetic testing and coordinated care.
Hematological involvement in nephropathic cystinosis: new insights
Authors: El-Ghamrawy Mona , Soliman Neveen A.
Published: September 2024

Nephropathic cystinosis (NC) is a rare autosomal recessive lysosomal storage disease characterized by defective lysosomal efflux of cystine due to variations in the CTNS gene encoding the lysosomal cystine transporter, cystinosin. This leads to pathological crystal accumulation in almost all tissues and organs in the body, affecting their functions. NC primarily affects the kidneys followed by a cascade of extrarenal organ involvement later in life. There are few reports of hematological complications as anemia or cytopenias; nevertheless, most of the reported data have been derived from case reports or small case series. Anemia/cytopenias in NC can be multifactorial in origin. Early identification and timely management of these alterations are critical to better growth, improved outcome, and quality of life of NC patients. Early diagnosis of NC, early initiation of both supportive and definitive cystine-depleting treatment, and adherence to therapy remain the mainstay for disease control and prevention of progression of some extrarenal complications. We hereby review hematological findings in NC, discuss the underlying contributing factors, suggest work-up, and highlight treatment options for hematological complications in NC patients. Given the multisystem nature of NC, we recommend integrated NC care approach with involvement of hematologist into its multidisciplinary team.
Observations and Simulations of a Double‐Core Hot Flow Anomaly
Authors: Lu Xi , Otto Antonius , Zhang Hui , Liu Terry , Chen Xingran
Published: September 2024

Hot Flow anomalies (HFAs), one of the most well‐analyzed transient phenomena in the Earth's foreshock, are known as kinetic structures driven by tangential discontinuities (TDs). Recently, a 2‐dimensional (2D) magnetohydrodynamics (MHD) model reproduced HFAs with either a high‐ or low‐density core. Further investigation of an HFA with two cores observed by the Magnetospheric Multiscale (MMS) mission is reported. The observation via the Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) mission suggests this MHD HFA is associated with a foreshock density hole‐like structure. The trailing flux tube in simulation may propagate with a TD in the foreshock. Our work suggests that HFAs with two low‐density cores can also be achieved in MHD process. Results show the total ram pressure can be an excellent diagnostic for the presence of transient structures, such as HFAs, at the bow shock.
Madden‐Julian Oscillation Contributes to the Skewed Intraseasonal PNA in El Niño and La Niña Winters
Authors: Zhou Fang , Jian Shenghua , Liu Minghong , Wang Run
Published: September 2024

The impact of the Madden‐Julian oscillation (MJO) on the intraseasonal PNA (ISPNA) was investigated and was found to be modulated by the El Niño‐Southern Oscillation (ENSO), which reasonably explains the skewness of the ISPNA during El Niño and La Niña winters. It was shown that the intensity and periodicity of the ISPNA was much stronger and slightly longer in La Niña winters than in the El Niño winters. The phase‐locked association between the ISPNA and MJO indicate that this skewness was controlled by the MJO. The northward Rossby wave activities derived from the tropics associated with the MJO to the subtropical Pacific sector of the ISPNA clarified that the stronger intensity of the MJO convection in the western Pacific during the La Niña winters, as well as the slower eastward propagation of the MJO, led to the asymmetric intensity and period of the ISPNA in the two ENSO phases.
The black powder behind battery power
Authors: Richards Jeffrey J. , Hipp Julie B.
Published: September 2024

Carbon black, a key ingredient in ancient inks, is used today to make the porous electrodes found in many rechargeable batteries. Understanding how to control its microstructure can pave the way to better-performing batteries.
Seeing the softer side of nanoparticles
Authors: Fattaruso Laura
Published: September 2024

Nanoparticles are coated with organic molecules that influence their size, shape, and behavior. A new technique opens a window to imaging those molecules in action.
NOAA to train thousands for jobs that will advance climate resilience
Authors: Means Hannah H.
Published: September 2024

Disadvantaged communities in coastal areas will participate in the new initiative.
Genome editing for improvement of biotic and abiotic stress tolerance in cereals
Authors: Inam Safeena , Muhammad Amna , Irum Samra , Rehman Nazia , Riaz Aamir , Uzair Muhammad , Khan Muhammad Ramzan
Published: September 2024

Global agricultural production must quadruple by 2050 to fulfil the needs of a growing global population, but climate change exacerbates the difficulty. Cereals are a very important source of food for the world population. Improved cultivars are needed, with better resistance to abiotic stresses like drought, salt, and increasing temperatures, and resilience to biotic stressors like bacterial and fungal infections, and pest infestation. A popular, versatile, and helpful method for functional genomics and crop improvement is genome editing. Rapidly developing genome editing techniques including clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) are very important. This review focuses on how CRISPR/Cas9 genome editing might enhance cereals’ agronomic qualities in the face of climate change, providing important insights for future applications. Genome editing efforts should focus on improving characteristics that confer tolerance to conditions exacerbated by climate change (e.g. drought, salt, rising temperatures). Improved water usage efficiency, salt tolerance, and heat stress resilience are all desirable characteristics. Cultivars that are more resilient to insect infestations and a wide range of biotic stressors, such as bacterial and fungal diseases, should be created. Genome editing can precisely target genes linked to disease resistance pathways to strengthen cereals’ natural defensive systems.
Providing a localised cervical cancer screening course for general practice nurses
Authors: Porter Joanne E. , Miller Elizabeth M. , Prokopiv Valerie , Sewell Lauren , Borgelt Kaye , Reimers Vaughan
Published: September 2024

Cervical cancer screening programs in Australia have been developed to detect early precancerous changes in women with a cervix aged between 25 and 74. Yet, many barriers remain to the uptake of cervical screening. Barriers include a lack of culturally appropriate service provision, physical access, poor health literacy, emotional difficulties, socio-economic disadvantage and not having access to a female service provider. In remote and very remote areas of Australia, additional barriers experienced by Aboriginal or Torres Strait Islander peoples include a distrust of healthcare providers and a lack of services, resulting in a much higher rate of diagnosis and death from cervical cancer. General practice nurses (GPNs) are well placed to conduct cervical screening tests (CSTs) after they have undertaken additional education and practical training. GPNs’ increase in scope of practice is beneficial to general practice as it helps to remove some barriers to cervical screening. In addition, GPNs conducting CSTs reduce GP workload and burnout and increase teamwork. GPNs working in metropolitan clinics have greater access to training facilities, whereas those working in rural and remote clinics are required to travel potentially long distances to complete practical assessments. This highlights the need for training to be made available in rural and remote areas. The aim of this forum paper is therefore to generate further discussion on the need for training programs to be made available in rural and remote areas to aid the upskilling of GPNs.
Genetic regulation of ovulation rate and multiple births
Authors: Montgomery G. W.
Published: September 2024

Ovulation rate in many mammalian species is controlled to regulate the numbers of offspring and maximise reproductive success. Pathways that regulate ovulation rate still respond to genetic and environmental factors and show considerable variation within and between species. Genetic segregation, positional cloning, and association studies have discovered numerous mutations and genetic risk factors that contribute to this variation. Notable among the discoveries has been the role of mutations in bone morphogenetic protein 15 (BMP15), growth differentiation factor 9 (GDF9) and bone morphogenetic protein receptor type 1B (BMPR1B) from the intra-ovarian signalling pathway contributing to the evidence that signalling from the oocyte is the key driver in follicle regulation rather than circulating gonadotrophin concentrations. Multiple variants in different domains of BMP15 and GDF9 result in partial or complete loss of function of the proteins providing insights into their functional roles and differential regulation contributing to species differences in ovulation rate. Early success encouraged many more studies in prolific strains of sheep, cattle and goats providing a valuable catalogue of genetic variants of large effect increasing ovulation rate and litter size. More recently, genetic association studies are beginning to identify genetic risk factors with smaller effects. Most genes implicated are from pathways with defined roles in regulation of the ovarian function. However, some genomic regions suggest regulation by novel genes. Continuing genetic and related functional studies will add further to our understanding of the detailed regulation of ovulation rate and litter size with implications for health and animal production systems.
Tracking vaccine effectiveness in an evolving pandemic, countering misleading hot takes and epidemiologic fallacies
Authors: Morris Jeffrey S
Published: September 2024

With the emergence of Omicron during the pandemic and the establishment of antibody waning over time, vaccine effectiveness, especially against infection, declined sharply from the original levels seen after the initial rollout. However, studies have demonstrated that they still provided substantial protection vs severe/fatal disease even with Omicron and after waning. Social media has been rife with reports claiming vaccines provided no benefit and some even claiming they made things worse, often driven by simple presentations of raw observational data using erroneous arguments involving epidemiologic fallacies including the base rate fallacy, Simpson’s paradox, and the ecological fallacy and ignoring the extensive bias especially from confounding that is an inherent feature of these data. Similar fallacious arguments have been made by some in promoting vaccination policies, as well. Generally, vaccine effectiveness cannot be accurately estimated from raw population summaries but instead require rigorous, careful studies using epidemiologic designs and statistical analysis tools attempting to adjust for key confounders and sources of bias. This article summarizes what aggregated evidence across studies reveals about effectiveness of the mRNA vaccines as the pandemic has evolved, chronologically summarized with emerging variants and highlighting some of the fallacies and flawed arguments feeding social media-based claims that have obscured society’s collective understanding.
Low foetal heart rate, a potentially ominous finding: case report
Authors: Afana Andreea Sorina , Filip Cristina , Cimpoca Brindusa , Dumitrascu-Biris Ioana , Jurcut Ruxandra
Published: September 2024

Background

Congenital long QT syndrome (LQTS) type 1 is characterized by abnormally prolonged ventricular repolarization caused by inherited defects in cardiac potassium channels. Patients are predisposed to ventricular arrhythmias and even sudden cardiac death. In some cases, foetal sinus bradycardia is the only sign, making prenatal diagnosis challenging. Physicians should be aware of this subtle presentation of LQTS. Early diagnosis and proactive treatment are crucial for preventing unexpected cardiac events.

Case summary

A healthy and asymptomatic 25-year-old pregnant woman was referred to our institute for cardiac evaluation after persistent foetal sinus bradycardia was detected during repeated ultrasounds, despite the absence of any foetal morphological or functional cardiac anomalies. After a thorough assessment, the mother was diagnosed with LQTS type 1, as confirmed by molecular genetic testing. Appropriate management, including maternal medication and increased surveillance, was initiated. The infant was delivered safely, and his electrocardiogram revealed a significantly prolonged QTc interval. Genetic testing confirmed the maternally inherited variant in KCNQ1 gene, and beta-blocker therapy was started. No arrhythmic events were noted.

Discussion

Detection and careful stratification of foetal heart rate (FHR) is crucial in every pregnancy. Foetal bradycardia can be caused by both maternal and foetal factors. Persistent low FHR should raise a high suspicion for LQTS. The condition may also present with atrioventricular blocks, torsades de pointes, or sudden intrauterine foetal demise. Accurate and early diagnosis of LQTS is essential for implementing appropriate management strategies, which include vigilant monitoring, effective medical treatment, careful planning of delivery, and post-natal care.
Aortic valve replacement vs. conservative treatment in asymptomatic severe aortic stenosis: long-term follow-up of the AVATAR trial
Authors: Banovic Marko , Putnik Svetozar , Da Costa Bruno R , Penicka Martin , Deja Marek A , Kotrc Martin , Kockova Radka , Glaveckaite Sigita , Gasparovic Hrvoje , Pavlovic Nikola , Velicki Lazar , Salizzoni Stefano , Wojakowski Wojtek , Van Camp Guy , Gradinac Sinisa , Laufer Michael , Tomovic Sara , Busic Ivan , Bojanic Milica , Ristic Arsen , Klasnja Andrea , Matkovic Milos , Boskovic Nikola , Zivic Katarina , Jovanovic Miodrag , Nikolic Serge D , Iung Bernard , Bartunek Jozef
Published: September 2024

Background and Aims

The question of when and how to treat truly asymptomatic patients with severe aortic stenosis (AS) and normal left ventricular (LV) systolic function is still subject to debate and ongoing research. Here, the results of extended follow-up of the AVATAR trial are reported (NCT02436655, ClinicalTrials.gov).

Methods

The AVATAR trial randomly assigned patients with severe, asymptomatic AS and LV ejection fraction ≥ 50% to undergo either early surgical aortic valve replacement (AVR) or conservative treatment with watchful waiting strategy. All patients had negative exercise stress testing. The primary hypothesis was that early AVR will reduce a primary composite endpoint comprising all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure (HF), as compared with conservative treatment strategy.

Results

A total of 157 low-risk patients (mean age 67 years, 57% men, mean Society of Thoracic Surgeons score 1.7%) were randomly allocated to either the early AVR group (n = 78) or the conservative treatment group (n = 79). In an intention-to-treat analysis, after a median follow-up of 63 months, the primary composite endpoint outcome event occurred in 18/78 patients (23.1%) in the early surgery group and in 37/79 patients (46.8%) in the conservative treatment group [hazard ratio (HR) early surgery vs. conservative treatment 0.42; 95% confidence interval (CI) 0.24–0.73, P = .002]. The Kaplan–Meier estimates for individual endpoints of all-cause death and HF hospitalization were significantly lower in the early surgery compared with the conservative group (HR 0.44; 95% CI 0.23–0.85, P = .012, for all-cause death and HR 0.21; 95% CI 0.06–0.73, P = .007, for HF hospitalizations).

Conclusions

The extended follow-up of the AVATAR trial demonstrates better clinical outcomes with early surgical AVR in truly asymptomatic patients with severe AS and normal LV ejection fraction compared with patients treated with conservative management on watchful waiting.
Darwin’s overlooked radiation: genomic evidence points to the early stages of a radiation in the Galápagos prickly pear cactus (Opuntia: Cactaceae)
Authors: Zapata Felipe , Cerca José , McCarney Dana , Henriquez Claudia L , Tiamiyu Bashir B , McCormack John E , Reckling Kelsey R , Chaves Jaime A , Rivas-Torres Gonzalo
Published: September 2024

In the Galápagos Islands, much attention has been devoted to the radiation of iconic species like Darwin’s finches, yet the Galápagos Islands offer an overlooked but equally remarkable opportunity for investigating plant radiations. Using a combination of genomic and phenotypic data, we present evidence of the early stages of a radiation in prickly pear cactus (Opuntia), a lineage widespread across the archipelago. We show that despite extensive ecophenotypic variation, there is limited genomic differentiation, consistent with the hypothesis that Opuntia is in the early stages of the diversification process. Phylogenomic and population genomic analyses show that notwithstanding low genetic differentiation across islands, there is marked geographical structure that is broadly consistent with the palaeogeography of the Galápagos. Because low genetic differentiation stands in stark contrast to the exceptional eco-phenotypic diversity displayed by cacti, it is plausible that the genetic architecture of phenotypic divergence mismatches our genomic sequencing, that phenotypic plasticity precedes genetic divergence and is the source of adaptive evolution, or that introgression influences local adaptation. Models of population relationships including admixture indicate that gene flow is common, probably facilitated by dispersal via animals known to feed on Opuntia flowers, fruits, and seeds. Because the prickly pear cacti of the Galápagos are a radiation in the making, they provide an exciting opportunity to investigate the interplay between ecological and genomic mechanisms promoting diversification.
Unde venis? Bacterial resistance from environmental reservoirs to lettuce: tracking microbiome and resistome over a growth period
Authors: Gekenidis Maria-Theresia , Vollenweider Vera , Joyce Aoife , Murphy Sinéad , Walser Jean-Claude , Ju Feng , Bürgmann Helmut , Hummerjohann Jörg , Walsh Fiona , Drissner David
Published: September 2024

Fresh produce is suggested to contribute highly to shaping the gut resistome. We investigated the impact of pig manure and irrigation water quality on microbiome and resistome of field-grown lettuce over an entire growth period. Lettuce was grown under four regimes, combining soil amendment with manure (with/without) with sprinkler irrigation using river water with an upstream wastewater input, disinfected by UV (with/without). Lettuce leaves, soil, and water samples were collected weekly and analysed by bacterial cultivation, 16S rRNA gene amplicon sequencing, and shotgun metagenomics from total community DNA. Cultivation yielded only few clinically relevant antibiotic-resistant bacteria (ARB), but numbers of ARB on lettuce increased over time, while no treatment-dependent changes were observed. Microbiome analysis confirmed a temporal trend. Antibiotic resistance genes (ARGs) unique to lettuce and water included multidrug and β-lactam ARGs, whereas lettuce and soil uniquely shared mainly glycopeptide and tetracycline ARGs. Surface water carried clinically relevant ARB (e.g. ESBL-producing Escherichia coli or Serratia fonticola) without affecting the overall lettuce resistome significantly. Resistance markers including biocide and metal resistance were increased in lettuce grown with manure, especially young lettuce (increased soil contact). Overall, while all investigated environments had their share as sources of the lettuce resistome, manure was the main source especially on young plants. We therefore suggest minimizing soil–vegetable contact to minimize resistance markers on fresh produce.
Testing treecbh in Central European forests: an R package for crown base height detection using high-resolution aerial laser-scanned data
Authors: Diószegi Gergő , Molnár Vanda Éva , Nagy Loránd Attila , Enyedi Péter , Török Péter , Szabó Szilárd
Published: September 2024

Accurate information regarding tree canopy characteristics is crucial for forest management, but it is often difficult to assess. This study presents an innovative framework designed for crown base height (CBH) detection using high-resolution laser-scanned data, with a specific focus on individual trees within forests. The framework comprises three key steps: (i) segmenting the input tree point cloud to identify the tree trunk and its branches using the treesio software; (ii) applying vertical cross-sectional K-means clustering to cluster the identified tree and to define the elevation threshold for removing low-lying understory vegetation; (iii) employing a novel 2D kernel method for detecting CBH after eliminating low-lying understory vegetation. The 2D kernel method, developed for broadleaf forests using leaf-off airborne laser scanning (ALS) data, underpins the treecbh tool. This tool features a visual CBH adjustment component that shows a 2D profile plot of the tree point cloud, and suggests a CBH value for user approval or adjustment. To evaluate accuracy, in situ measured CBH data from five forest plots in Germany and Hungary with varied species compositions were used. ALS data were collected during leaf-off conditions for the two Hungarian plots and during leaf-on conditions for the three German plots. Leaf-off terrestrial laser-scanned data from individual trees were also used in the accuracy assessment. A sensitivity analysis using random point decimation was conducted on the terrestrial laser-scanned data to assess treecbh’s sensitivity to point density. The initial results exhibited matching rates of 45% and 60% for leaf-off ALS plots, which significantly improved to 71% and 77%, respectively, when using the visual CBH adjustment feature of the tool. The leaf-on ALS results demonstrated matching rates between 24% and 33%, whereas the CBHs of individual terrestrial laser-scanned trees could be detected with 93% accuracy in visual mode. It was observed that treecbh operates effectively when the input ALS data have a minimum point density of 20 pts/${\text{m}}^2$, with its optimal performance achieved at 110 pts/${\text{m}}^2$. These findings indicated treecbh’s sensitivity to ALS data quality, scanning season (leaf-on and leaf-off), and point density. This sensitivity can be effectively mitigated in the case of leaf-off ALS data by utilizing the visual CBH adjustment feature of the tool.
TRIM25 activates Wnt/β-catenin signalling by destabilising MAT2A mRNA to drive thoracic aortic aneurysm development
Authors: Li Chaojie , Wang Kan , Fang Jian , Qin Lin , Ling Qiong , Yu Yu
Published: September 2024

This study explored the roles of methionine adenosyltransferase 2A (MAT2A) and tripartite motif containing 25 (TRIM25) in the progression of thoracic aortic aneurysm (TAA). The TAA model was established based on the β-aminopropionitrile method. The effects of MAT2A on thoracic aortic lesions and molecular levels were analyzed by several pathological staining assays (hematoxylin–eosin, Verhoeff-Van Gieson, TUNEL) and molecular biology experiments (qRT-PCR, Western blot). Angiotensin II (Ang-II) was used to induce injury in vascular smooth muscle cells (VSMCs) in vitro. The effects of MAT2A, shMAT2A, shTRIM25 and/or Wnt inhibitor (IWR-1) on the viability, apoptosis and protein expressions of VSMCs were examined by CCK-8, Annexin V-FITC/PI and Western blot assays. In TAA mice, overexpression of MAT2A alleviated thoracic aortic injury, inhibited the aberrant expressions of aortic contractile proteins and dedifferentiation markers, and blocked the activation of Wnt/β-catenin pathway. In Ang-II-induced VSMCs, up-regulation of MAT2A increased cellular activity and repressed the expression of β-catenin protein. TRIM25 knockdown promoted activity of VSMCs, inhibited apoptosis, and blocked the Wnt/β-catenin pathway activation by binding to MAT2A. IWR-1 partially counteracted the regulatory effects of shMAT2A. Collectively, TRIM25 destabilises the mRNA of MAT2A to activate Wnt/β-catenin signaling and ultimately exacerbate TAA injury.
Continuous finite elements satisfying a strong discrete Miranda–Talenti identity
Authors: Gallistl Dietmar , Tian Shudan
Published: September 2024

This article introduces continuous $H^{2}$-nonconforming finite elements in two and three space dimensions that satisfy a strong discrete Miranda–Talenti inequality in the sense that the global $L^{2}$ norm of the piecewise Hessian is bounded by the $L^{2}$ norm of the piecewise Laplacian. The construction is based on globally continuous finite element functions with $C^{1}$ continuity on the vertices (2D) or edges (3D). As an application, these finite elements are used to approximate uniformly elliptic equations in nondivergence form under the Cordes condition without additional stabilization terms. For the biharmonic equation in three dimensions, the proposed methods has less degrees of freedom than existing nonconforming schemes of the same order. Numerical results in two and three dimensions confirm the practical feasibility of the proposed schemes.
A novel explicit optimized scheme for numerical simulation of elastic-wavefield separation
Authors: Guo Zixi , Huang Jiandong , Chen Dong , Chen Yiyu
Published: September 2024

Numerical simulation of elastic-wave equation helps us better understand the information of underground structures and elastic-wave imaging has attracted the widespread attention of researchers. Using elastic-wave imaging requires separating the compressional and shear wavefields. Therefore, we develop a novel explicit optimized scheme to simulate the separated elastic wavefield. We construct a kind of 1-norm objective function directly utilizing the dispersion error and employ the simulated annealing algorithm to acquire improved finite-difference operators, whose optimal coefficients can effectively suppress spatial numerical dispersion. Meanwhile, we introduce a rotated staggered-grid (RSG) approach to enhance computational stability. Then, our proposed scheme, called the optimized RSG approach, is applied to the elastic-wave equations and decoupled elastic-wave equations to simulate the decoupled compressional and shear wavefield propagation. Numerical dispersion analysis is consistent with numerical results. The waveform comparison shows that the optimized RSG approach possesses higher accuracy, and several complex models are used to validate the applicability and effectiveness of the presented scheme.
Working Vacations and Adventure: American Women Physician Volunteers to the Labrador Mission of Wilfred Grenfell Before 1914
Authors: Connor Jennifer J
Published: September 2024

Many accounts, autobiographical and scholarly, emphasize how volunteers portrayed their work in the mission established for fishers by British physician Wilfred Grenfell in Newfoundland and Labrador: as escapist adventure. Scholars have not studied women physicians or their motivations to volunteer, however. This oversight derives from their small number combined with lack of knowledge about this mission’s distinction from the foreign medical missions and domestic frontier missions that drew many women physicians to permanent positions. This study therefore discusses two American physicians, Alfreda B. Withington (1860-1951) and Emma E. Musson (1862-1913), who volunteered for summer service with this mission in 1907 and 1909, respectively. Through their publications, biographical sources, and clinical accounts, it reveals the appeal to them of such temporary, accessible volunteer service as a working vacation that rejuvenated. Importantly, it counters the skewed perspective of contemporary accounts in which the connection of Withington and Musson to an international celebrity, Wilfred Grenfell, overrode fuller considerations of their own lives, careers, and experiences. Finally, this examination suggests possible differences in their volunteerism between women physicians and their male counterparts: along with other women professionals, medical women often incorporated volunteer vacation experience into a continuum of similar endeavors in their careers.
Attenuation of HIV-specific T cell responses Among people with HIV on ART following dipyridamole treatment
Authors: Morris Benjamin C , Hixson Emily A , Klamar-Blain Cynthia , Gillespie Delbert G , Abebe Kaleab Z , Rinaldo Charles R , Mellors John W , Jackson Edwin K , Riddler Sharon A , Macatangay Bernard J C
Published: September 2024

Twelve weeks of dipyridamole increased extracellular adenosine levels and decreased T cell activation in people with human immunodeficiency virus (HIV). In this analysis, we investigated the effect of dipyridamole on HIV-specific T cell responses. We compared changes in Gag- and Env-specific T cell responses using intracellular cytokine staining, following 12 wk of dipyridamole treatment vs placebo. We evaluated whether frequencies of polyfunctional HIV-specific T cells were associated with purines in the adenosine pathway and with measures of HIV persistence and chronic inflammation. There was a significant decrease in CD4+ polyfunctional T cell responses to Gag (−62.6% vs −23.0%; P < 0.001) and Env (−56.1% vs −6.0%; P < 0.001) in the dipyridamole arm. In the dipyridamole group, lower frequencies of polyfunctional Env-specific CD4+ T cells were associated with higher plasma levels of adenosine (r = −0.85, P < 0.01) and inosine (r = −0.70, P = 0.04). Higher adenosine levels induced by dipyridamole treatment is associated with decreased HIV-specific CD4+ T cell polyfunctional responses in people with HIV on antiretroviral therapy.
Trajectories of sexual well-being and links with grief after a recent pregnancy loss: a dyadic longitudinal study
Authors: Allsop David B , Péloquin Katherine , Cockwell Heather , Rosen Natalie O
Published: September 2024

Background

Pregnancy loss affects 1 in 4 women and is linked with poorer overall health and relationship outcomes. Despite sexual well-being’s importance to health, how sexual well-being changes across time after a pregnancy loss and what might predict such changes, like perinatal grief, have never been examined, leaving practitioners and couples without knowledge of what to expect.

Aim

We aimed to examine (1) how sexual satisfaction, sexual desire, sexual distress, and perinatal grief change from 10 to 25 weeks postloss for both couple members; and (2) if perinatal grief levels at 10 weeks postloss predict sexual well-being trajectories.

Methods

Women and gender-diverse individuals who were pregnant when a pregnancy loss occurred (within the last 4 months) and men, women, and gender-diverse partners who were not pregnant (N = 132 couples) independently completed 4 monthly assessments of sexual well-being and perinatal grief.

Outcomes

Outcomes included sexual satisfaction (Global Measure of Sexual Satisfaction), sexual desire (Sexual Desire Inventory), sexual distress (Sexual Distress Scale–Short Form), perinatal grief (Perinatal Grief Scale).

Results

Dyadic growth curve modeling indicated that, from 10 to 25 weeks postloss, both couple members’ sexual satisfaction increased, and their sexual desire remained stable; sexual distress decreased for partners but remained stable for individuals who were pregnant; and both couple members’ perinatal grief decreased. Perinatal grief levels at 10 weeks postloss did not predict sexual well-being trajectories over time.

Clinical Implications

Given sexual well-being’s dynamic nature, clinicians should regularly discuss sexuality with both couple members after pregnancy loss. During such discussions, clinicians could reassure couples about their sexual relationship’s recovery by sharing that, on average, sexual satisfaction, sexual desire, and sexual distress tend to improve or stay the same (rather than worsen) from 10 to 25 weeks postloss. They can also share that perinatal grief tends to decrease during this time and is unrelated to trajectories of sexual satisfaction, sexual desire, and sexual distress.

Strengths and limitations

This is the first study, to our knowledge, to examine how sexual well-being changes across time after a pregnancy loss and perinatal grief’s role in such changes. The results may not generalize broadly, as most couples were in mixed-gender/sex relationships, identified as White, and were relatively affluent.

Conclusion

From 10 to 25 weeks postloss, both couple members tend to experience improvements in their overall sexual well-being and declines in their perinatal grief. Early perinatal grief levels and subsequent sexual well-being trajectories are seemingly unrelated.
Constraining the physical properties of large-scale jets from black hole X-ray binaries and their impact on the local environment with blast-wave dynamical models
Authors: Carotenuto F , Fender R , Tetarenko A J , Corbel S , Zdziarski A A , Shaik G , Cooper A J , Palma I Di
Published: September 2024

Relativistic discrete ejecta launched by black hole X-ray binaries (BH XRBs) can be observed to propagate up to parsec-scales from the central object. Observing the final deceleration phase of these jets is crucial to estimate their physical parameters and to reconstruct their full trajectory, with implications for the jet powering mechanism, composition, and formation. In this paper, we present the results of the modelling of the motion of the ejecta from three BH XRBs: MAXI J1820$+$070, MAXI J1535–571, and XTE J1752–223, for which high-resolution radio and X-ray observations of jets propagating up to $\sim$15 arcsec ($\sim$0.6 pc at 3 kpc) from the core have been published in the recent years. For each jet, we modelled its entire motion with a dynamical blast-wave model, inferring robust values for the jet Lorentz factor, inclination angle and ejection time. Under several assumptions associated to the ejection duration, the jet opening angle and the available accretion power, we are able to derive stringent constraints on the maximum jet kinetic energy for each source (between $10^{43}$ and $10^{44}$ erg, including also H1743–322), as well as placing interesting upper limits on the density of the ISM through which the jets are propagating (from $n_{\rm ISM} \lesssim 0.4$ cm$^{-3}$ down to $n_{\rm ISM} \lesssim 10^{-4}$ cm$^{-3}$). Overall, our results highlight the potential of applying models derived from gamma-ray bursts to the physics of jets from BH XRBs and support the emerging picture of these sources as preferentially embedded in low-density environments.
Exploring mass measurements of supermassive black holes in AGN using GAMA photometry and spectroscopy
Authors: Casura Sarah , Ilić Dragana , Targaczewski Jonathan , Rakić Nemanja , Liske Jochen
Published: September 2024

In the era of massive photometric surveys, we explore several approaches to estimate the masses of supermassive black holes (SMBHs) in active galactic nuclei (AGNs) from optical ground-based imaging, in each case comparing to the independent SMBH mass measurement obtained from spectroscopic data. We select a case-study sample of 28 type 1 AGN hosted by nearby galaxies from the Galaxy And Mass Assembly (GAMA) survey. We perform multicomponent spectral decomposition, extract the AGN component, and calculate the SMBH mass from the broad H$\alpha$ emission line width and luminosity. The photometric g and i band data is decomposed into AGN+spheroid(+disc)(+bar) components with careful surface brightness fitting. From these, the SMBH mass is estimated using its relation with the spheroid Sérsic index or effective radius (both used for the first time on ground-based optical imaging of AGN); and the more widely used scaling relations based on bulge or galaxy stellar mass. We find no correlation between the H$\alpha$-derived SMBH masses and those based on the spheroid Sérsic index or effective radius, despite these being the most direct methods involving only one scaling relation. The bulge or galaxy stellar mass based methods both yield significant correlations, although with considerable scatter and, in the latter case, a systematic offset. We provide possible explanations for this and discuss the requirements, advantages, and drawbacks of each method. These considerations will be useful to optimize strategies for upcoming high quality ground-based and space-borne sky surveys to estimate SMBH masses in large numbers of AGN.
A GMRT 610 MHz radio survey of the North Ecliptic Pole (NEP, ADF-N) / Euclid Deep Field North
Authors: White Glenn J , Barrufet L , Serjeant S , Pearson C P , Sedgwick C , Pal S , Shimwell T W , Sirothia S K , Chiu P , Oi N , Takagi T , Shim H , Matsuhara H , Patra D , Malkan M , Kim H K , Nakagawa T , Malek K , Burgarella D , Ishigaki T
Published: September 2024

This paper presents a 610 MHz radio survey covering 1.94 deg$^2$ around the North Ecliptic Pole (NEP), which includes parts of the ${\it AKARI}$ (ADF-N) and Euclid, Deep Fields North. The median 5$\sigma$ sensitivity is 28 $\mu$Jy beam$^{-1}$, reaching as low as 19 $\mu$Jy beam$^{-1}$, with a synthesized beam of 3.6 arcsec $\times$ 4.1  arcsec. The catalogue contains 1675 radio components, with 339 grouped into multicomponent sources and 284 ‘isolated’ components likely part of double radio sources. Imaging, cataloguing, and source identification are presented, along with preliminary scientific results. From a non-statistical sub-set of 169 objects with multiwavelength AKARI and other detections, luminous infrared galaxies (LIRGs) represent 66 ${{\ \rm per\ cent}}$ of the sample, ultra-luminous infrared galaxies (ULIRGs) 4 ${{\ \rm per\ cent}}$, and sources with L$_{IR}$ < 10$^{11}$ $\mathrm{ L}_{\odot }\,$  30${{\ \rm per\ cent}}$. In total, 56 ${{\ \rm per\ cent}}$ of sources show some AGN presence, though only seven are AGN-dominated. ULIRGs require three times higher AGN contribution to produce high-quality SED fits compared to lower luminosity galaxies, and AGN presence increases with AGN fraction. The PAH mass fraction is not significant, although ULIRGs have about half the PAH strength of lower IR-luminosity galaxies. Higher luminosity galaxies show gas and stellar masses an order of magnitude larger, suggesting higher star formation rates. For LIRGs, AGN presence increases with redshift, indicating that part of the total luminosity could be contributed by AGN activity rather than star formation. Simple cross-matching revealed 13 ROSAT QSOs, 45 X-ray sources, and 61 sub-mm galaxies coincident with GMRT radio sources.
Stable potassium isotope ratios in human blood serum towards biomarker development in Alzheimer's disease
Authors: Mahan Brandon , Hu Yan , Lahoud Esther , Nestmeyer Mark , McCoy-West Alex , Manestar Grace , Fowler Christopher , Bush Ashley I , Moynier Frédéric
Published: September 2024

The Alzheimer's disease (AD)-affected brain purges K with concurrently increasing serum K, suggesting brain–blood K transferal. Here, natural stable K isotope ratios—δ41K—of human serum samples were characterized in an AD biomarker pilot study (plus two paired Li-heparin and potassium ethylenediaminetetraacetic acid [K-EDTA] plasma samples). AD serum was found to have a significantly lower mean δ41K relative to controls. To mechanistically explore this change, novel ab initio calculations (density functional theory) of relative K isotope compositions between hydrated K+ and organically bound K were performed, identifying hydrated K+ as isotopically light (lower δ41K) compared to organically bound K. Taken together with literature, serum δ41K and density functional theory results are consistent with efflux of hydrated K+ from the brain to the bloodstream, manifesting a measurable decrease in serum δ41K. These data introduce serum δ41K for further investigation as a minimally invasive AD biomarker, with cost, scalability, and stability advantages over current techniques.
Second generation lethality in RNAseH2a knockout zebrafish
Authors: Thomas Ruth C , Zaksauskaite Ringaile , Al-Kandari Norah Y , Hyde Anne Cathrine , Abugable Arwa A , El-Khamisy Sherif F , van Eeden Freek J
Published: September 2024

Removal of ribonucleotides from DNA by RNaseH2 is essential for genome stability, and its impacted function causes the neurodegenerative disease, Aicardi Goutières Syndrome. We have created a zebrafish rnaseh2a mutant to model this process. Surprisingly, RNaseH2a knockouts show little phenotypic abnormality at adulthood in the first generation, unlike mouse knockout models, which are early embryonic lethal. However, the second generation offspring show reduced development, increased ribonucleotide incorporation and upregulation of key inflammatory markers, resulting in both maternal and paternal embryonic lethality. Thus, neither fathers or mothers can generate viable offspring even when crossed to wild-type partners. Despite their survival, rnaseh2a−/− adults show an accumulation of ribonucleotides in both the brain and testes that is not present in early development. Our data suggest that homozygotes possess RNaseH2 independent compensatory mechanisms that are inactive or overwhelmed by the inherited ribonucleotides in their offspring, or that zebrafish have a yet unknown tolerance mechanism. Additionally, we identify ribodysgenesis, the rapid removal of rNMPs and subsequently lethal fragmentation of DNA as responsible for maternal and paternal embryonic lethality.
Unlocking precision in aptamer engineering: a case study of the thrombin binding aptamer illustrates why modification size, quantity, and position matter
Authors: Murray Makay T , Wetmore Stacey D
Published: September 2024

The thrombin binding aptamer (TBA) is a prototypical platform used to understand the impact of chemically-modified nucleotides on aptamer stability and target affinity. To provide structural insight into the experimentally-observed effects of modification size, location, and number on aptamer performance, long time-scale molecular dynamics (MD) simulations were performed on multiple binding orientations of TBA–thrombin complexes that contain a large, flexible tryptophan thymine derivative (T-W) or a truncated analogue (T-K). Depending on modification position, T-W alters aptamer–target binding orientations, fine-tunes aptamer–target interactions, strengthens networks of nucleic acid–protein contacts, and/or induces target conformational changes to enhance binding. The proximity and 5′-to-3′ directionality of nucleic acid structural motifs also play integral roles in the behavior of the modifications. Modification size can differentially influence target binding by promoting more than one aptamer–target binding pose. Multiple modifications can synergistically strengthen aptamer–target binding by generating novel nucleic acid–protein structural motifs that are unobtainable for single modifications. By studying a diverse set of modified aptamers, our work uncovers design principles that must be considered in the future development of aptamers containing chemically-modified nucleotides for applications in medicine and biotechnology, highlighting the value of computational studies in nucleic acids research.