bluuebunny/crossref_metadata_2025_split huggingface dataset:
A class of graphs of zero Turán density in a hypercube
Authors: Axenovich Maria 
Published: March 2024

AbstractFor a graph
$H$
and a hypercube
$Q_n$
,
$\textrm{ex}(Q_n, H)$
is the largest number of edges in an
$H$
-free subgraph of
$Q_n$
. If
$\lim _{n \rightarrow \infty } \textrm{ex}(Q_n, H)/|E(Q_n)| \gt 0$
,
$H$
is said to have a positive Turán density in a hypercube or simply a positive Turán density; otherwise, it has zero Turán density. Determining
$\textrm{ex}(Q_n, H)$
and even identifying whether
$H$
has a positive or zero Turán density remains a widely open question for general
$H$
. By relating extremal numbers in a hypercube and certain corresponding hypergraphs, Conlon found a large class of graphs, ones having so-called partite representation, that have zero Turán density. He asked whether this gives a characterisation, that is, whether a graph has zero Turán density if and only if it has partite representation. Here, we show that, as suspected by Conlon, this is not the case. We give an example of a class of graphs which have no partite representation, but on the other hand, have zero Turán density. In addition, we show that any graph whose every block has partite representation has zero Turán density in a hypercube.
Organisation of paediatric echocardiography laboratories and governance of echocardiography services and training in Europe: current status, disparities, and potential solutions. A survey from the Association for European Paediatric and Congenital Cardiology (AEPC) imaging working group
Authors: Cantinotti Massimiliano , Voges Inga , Miller Owen , Raimondi Francesca , Grotenhuis Heynric , Bharucha Tara , Garrido Almudena Ortiz , Valsangiacomo Emanuela , Roest Arno , Sunnegårdh Jan , Salaets Thomas , Brun Henrik , Khraiche Diala , Jossif Antonis , Schokking Michiel , Sabate-Rotes Anna , Meyer-Szary Jaroslaw , Deri Antigoni , Koopman Laurens , Herberg Ulrike , du Marchie Sarvaas Gideon , Leskinen Markku , Tchana Bertrand , Ten Harkel Arend D.J. , Ödemis Ender , Morrison Louise , Steimetz Micheal , Laser Kai Thorsten , Doros Gabriela , Bellshan-Revell Hannah , Muntean Iolanda , Anagostopoulou Andriana , Alpman Maria Sjoborg , Hunter Lindsey , Ojala Tiina , Bhat Misha , Olejnik Peter , Wacker Julie , Bonello Beatrice , Ramcharan Tristan , Greil Gerald , Marek Jan , DiSalvo Giovanni , McMahon Colin J. 
Published: March 2024

AbstractBackground:There is limited data on the organisation of paediatric echocardiography laboratories in Europe.Methods:A structured and approved questionnaire was circulated across all 95 Association for European Paediatric and Congenital Cardiology affiliated centres. The aims were to evaluate: (1) facilities in paediatric echocardiography laboratories across Europe, (2) accredited laboratories, (3) medical/paramedical staff employed, (4) time for echocardiographic studies and reporting, and (5) training, teaching, quality improvement, and research programs.Results:Respondents from forty-three centres (45%) in 22 countries completed the survey. Thirty-six centres (84%) have a dedicated paediatric echocardiography laboratory, only five (12%) of which reported they were European Association of Cardiovascular Imaging accredited. The median number of echocardiography rooms was three (range 1–12), and echocardiography machines was four (range 1–12). Only half of all the centres have dedicated imaging physiologists and/or nursing staff, while the majority (79%) have specialist imaging cardiologist(s). The median (range) duration of time for a new examination was 45 (20–60) minutes, and for repeat examination was 20 (5–30) minutes. More than half of respondents (58%) have dedicated time for reporting. An organised training program was present in most centres (78%), 44% undertake quality assurance, and 79% perform research. Guidelines for performing echocardiography were available in 32 centres (74%).Conclusion:Facilities, staffing levels, study times, standards in teaching/training, and quality assurance vary widely across paediatric echocardiography laboratories in Europe. Greater support and investment to facilitate improvements in staffing levels, equipment, and governance would potentially improve European paediatric echocardiography laboratories.
Bilateral ductal stenting in an infant with pulmonary atresia and ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct
Authors: Padovani Paul , Ly Mohamedou , Baruteau Alban-Elouen 
Published: March 2024

AbstractPulmonary atresia with ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct is a rare and complex CHD. Physiologic ductal closure may lead to life-threatening hypoxia. We present a case of successful bilateral ductal stenting as a bridge to further lower-risk surgical repair.
A pilot evaluation of a training and supervision pathway for Augmented Depression Therapy (ADepT) in a Devon NHS Talking Therapies Service
Authors: Warbrick Laura A. , Meehan Bradán , Carson James , Mackenzie Jo , Dunn Barnaby D. 
Published: March 2024

Abstract
Augmented Depression Therapy (ADepT) is a novel wellbeing and recovery-oriented psychological treatment for depression. A recent pilot trial run in a university clinic setting suggests ADepT has potential to be superior to cognitive behavioural therapy (CBT) at treating anhedonic depression in a NHS Talking Therapies for anxiety and depression (NHS–TTad) context. Before proceeding to definitive trial in pragmatic settings, it is important to establish if therapists in routine NHS-TTad settings can be trained to deliver ADepT effectively and to assess therapist views on the feasibility and acceptability of ADepT in this context. A bespoke training and supervision pathway was developed (2-day workshop, four 2–hour skills classes, and 6 months of weekly supervision) and piloted with 11 experienced therapists working in a single NHS–TT service in Devon. Nine out of 11 therapists completed the placement, treating 24 clients with a primary presenting problem of depression; 21/24 completed a minimum adequate dose of therapy (≥8 sessions), with 17/24 (71%) showing reliable improvement and 12/24 (50%) exhibiting reliable recovery. Eight out of nine therapists submitted a session for competency assessment, all of whom were rated as competent. Nine therapists submitted feedback on their experiences of training. Eight out of nine therapists felt the ADepT model would be effective in an NHS–TTad context; that training was interesting, useful, well presented and enhanced their own wellbeing; and that they felt sufficiently skilled in core ADepT competencies at the end of the placement. This suggests that NHS–TTad therapists can be trained to deliver ADepT competently and view the treatment as feasible and acceptable.

Key learning aims

(1)
To become familiar with the Augmented Depression Therapy (ADepT) approach for enhancing wellbeing in depression.

(2)
To evaluate the potential utility and feasibility of ADepT model in NHS Talking Therapies Services (NHS–TTad).

(3)
To understand the pilot ADepT training and supervision pathway for CBT therapists in NHS–TTad services.

(4)
To consider the opportunities and challenges of training therapists to deliver ADepT in NHS–TTad services.
Do Vegetation Fuel Reduction Treatments Alter Forest Fire Severity and Carbon Stability in California Forests?
Authors: Daum Kristofer L. , Hansen Winslow D. , Gellman Jacob , Plantinga Andrew J. , Jones Charles , Trugman Anna T. 
Published: March 2024

AbstractForest fire frequency, extent, and severity have rapidly increased in recent decades across the western United States (US) due to climate change and suppression‐oriented wildfire management. Fuels reduction treatments are an increasingly popular management tool, as evidenced by California's plan to treat 1 million acres annually by 2050. However, the aggregate efficacy of fuels treatments in dry forests at regional and multi‐decadal scales is unknown. We develop a novel fuels treatment module within a coupled dynamic vegetation and fire model to study the effects of dead biomass removal from forests in the Sierra Nevada region of California. We ask how annual treatment extent, stand‐level treatment intensiveness, and spatial treatment placement alter fire severity and live carbon loss. We find that a ∼30% reduction in stand‐replacing fire was achieved under our baseline treatment scenario of 1,000 km2 year−1 after a 100‐year treatment period. Prioritizing the most fuel‐heavy stands based on precise fuel distributions yielded cumulative reductions in pyrogenic stand‐replacement of up to 50%. Both removing constraints on treatment location due to remoteness, topography, and management jurisdiction and prioritizing the most fuel‐heavy stands yielded the highest stand‐replacement rate reduction of ∼90%. Even treatments that succeeded in lowering aggregate fire severity often took multiple decades to yield measurable effects, and avoided live carbon loss remained negligible across scenarios. Our results suggest that strategically placed fuels treatments are a promising tool for controlling forest fire severity at regional, multi‐decadal scales, but may be less effective for mitigating live carbon losses.
Transient Offset in 14C After the Carrington Event Recorded by Polar Tree Rings
Authors: Uusitalo Joonas , Golubenko Kseniia , Arppe Laura , Brehm Nicolas , Hackman Thomas , Hayakawa Hisashi , Helama Samuli , Mizohata Kenichiro , Miyake Fusa , Mäkinen Harri , Nöjd Pekka , Tanskanen Eija , Tokanai Fuyuki , Rozanov Eugene , Wacker Lukas , Usoskin Ilya , Oinonen Markku 
Published: March 2024

AbstractThe Carrington event of 1859 has been the strongest solar flare in the observational history. It plays a crucial role in shedding light on the frequency and impacts of the past and future Solar Energetic Particle (SEP) events on human societies. We address the impact of the Carrington event by measuring tree‐ring 14C with multiple replications from high‐latitude locations around the event and by comparing them with mid‐latitude measurements. A transient offset in 14C following the event is observed with high statistical significance. Our state‐of‐the‐art 14C production and transport model does not reproduce the observational finding, suggesting features beyond present understanding. Particularly, our observation would require partially fast transport of 14C between the stratosphere and troposphere at high latitudes. The observation is consistent with the previous findings with the SEP events of 774 and 993 CE for which faster integration of 14C into tree rings is observed at high latitudes.
Localized Magnetopause Erosion at Geosynchronous Orbit by Reconnection
Authors: Kim Hyangpyo , Nakamura Rumi , Connor Hyunju K. , Zou Ying , Plaschke Ferdinand , Grimmich Niklas , Walsh Brian M. , McWilliams Kathryn A. , Ruohoniemi J. Michael 
Published: March 2024

AbstractThis study presents observations of magnetopause reconnection and erosion at geosynchronous orbit, utilizing in situ satellite measurements and remote sensing ground‐based instruments. During the main phase of a geomagnetic storm, Geostationary Operational Environmental Satellites (GOES) 15 was on the dawnside of the dayside magnetopause (10.6 MLT) and observed significant magnetopause erosion, while GOES 13, observing duskside (14.6 MLT), remained within the magnetosphere. Combined observations from the THEMIS satellites and Super Dual Auroral Radar Network radars verified that magnetopause erosion was primarily caused by reconnection. While various factors may contribute to asymmetric erosion, the observations suggest that the weak reconnection rate on the duskside can play a role in the formation of asymmetric magnetopause shape. This discrepancy in reconnection rate is associated with the presence of cold dense plasma on the duskside of the magnetosphere, which limits the reconnection rate by mass loading, resulting in more efficient magnetopause erosion on the dawnside.
Fracturing and Dome‐Shaped Surface Displacements Above Laccolith Intrusions: Insights From Discrete Element Method Modeling
Authors: Morand A. , Poppe S. , Harnett C. , Cornillon A. , Heap M. , Mège D. 
Published: March 2024

AbstractInflation of viscous magma intrusions in Earth's shallow crust often induces strain and fracturing within heterogeneous host rocks and dome‐shaped ground deformation. Most geodetic models nevertheless consider homogeneous, isotropic, and linear‐elastic media wherein stress patterns indicate the potential for failure, but without simulating actual fracturing. We present a two‐dimensional Discrete Element Method (DEM) application to simulate magma recharge in a pre‐existing laccolith intrusion. In DEM models, fractures can propagate during simulations. We systematically investigate the effect of the host rock toughness (resistance to fracturing), stiffness (resistance to deformation) and the intrusion depth, on intrusion‐induced stress, strain, displacement and spatial fracture distribution. Our results show that the spatial fracture distribution varies between two end‐members: (a) for high stiffness or low toughness host rock or a shallow intrusion: extensive cracking, multiple vertical surface fractures propagating downward and two inward‐dipping highly cracked shear zones that connect the intrusion tip with the surface; and (b) for low stiffness or high toughness host rock or a deeper intrusion: limited cracking, one central vertical fracture initiated at the surface, and two inward‐dipping fractures at the intrusion tips. Abrupt increases in surface displacement magnitude occur in response to fracturing, even at constant magma injection rates. Our modeling application provides a novel approach to considering host rock mechanical strength and fracturing during viscous magma intrusion and associated dome‐shaped ground deformation, with important implications for interpreting geodetic signals at active volcanoes and the exploitation of geothermal reservoirs and mineral deposits.
Phase Relation and Equation of State of Iron‐Titanium Oxyhydroxides With α‐PbO2 Type Crystal Structure at Deep Mantle Conditions
Authors: Matsukage Kyoko N. , Nishihara Yu , Tange Yoshinori , Higo Yuji 
Published: March 2024

AbstractPhase relation and equation of state of iron‐titanium oxyhydroxide with α‐PbO2‐type crystal structure (hydrous α‐phase) was investigated at pressure from middle upper mantle to mantle transition zone. The experiments were performed using multi‐anvil apparatus with in situ synchrotron X‐ray diffraction. The metal‐diamond sample container was used to maintain a closed system with respect to water while allowing X‐ray transmittance. Starting materials were mixture of reagent grade goethite and anatase with Fe:Ti = 1:1 and 1:3. The hydrous α‐phase was synthesized at 11–14 GPa and 800–900°C. The X‐ray diffraction data were obtained over a wide range of pressures from 5 to 22 GPa and temperatures from room temperature to 930°C. Using pressure‐volume‐temperature data of the hydrous α‐phase with Fe:Ti = 1:1 collected at room temperature to 800°C and at 8.9–20.8 GPa, we determined the isothermal bulk modulus (KT0 = 183 (1) GPa) and the thermal expansivity (α0 = 3.29 (1) × 10−5K−1) at ambient condition. The stability field of the hydrous α‐phase and phase relation of FeOOH‐TiO2 system at 900°C was well constrained. It was found that the hydrous α‐phase decomposes into baddeleyite‐type TiO2 + ε‐FeOOH at pressure of approximately 20–21 GPa, and into ilmenite + rutile at 5–6 GPa. This stability field equivalent to depth of 180–600 km in the subduction zone. Our results suggest that the hydrous α‐phase is an important water reservoir in the middle upper mantle to mantle transition zone.
Chiral transmission by an open evolution trajectory in a non-Hermitian system
Authors: Shu Xiaoqian , Zhong Qi , Hong Kai , You Oubo , Wang Jian , Hu Guangwei , Alù Andrea , Zhang Shuang , Christodoulides Demetrios N. , Chen Lin 
Published: March 2024

AbstractExceptional points (EPs), at which two or more eigenvalues and eigenstates of a resonant system coalesce, are associated with non-Hermitian Hamiltonians with gain and/or loss elements. Dynamic encircling of EPs has received significant interest in recent years, as it has been shown to lead to highly nontrivial phenomena, such as chiral transmission in which the final state of the system depends on the encircling handedness. Previously, chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time- (PT-) or anti-PT-symmetric systems. Although chiral transmission of symmetry-broken modes, more accessible in practical photonic integrated circuits, has been realized by establishing a closed trajectory encircling EPs in anti-PT-symmetric systems, the demonstrated transmission efficiency is very low due to path-dependent losses. Here, we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed trajectory. Specifically, we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes (not modes in PT- and anti-PT-symmetric systems), demonstrating that this platform enables high-efficiency chiral transmission, with each eigenmode localized in a single waveguide. This concept is experimentally implemented in a coupled silicon waveguide system at telecommunication wavelengths. Our work provides a new evolution strategy for chiral dynamics with superior performance, laying the foundation for the development of practical chiral-transmission devices.
Scalable parallel ultrafast optical random bit generation based on a single chaotic microcomb
Authors: Li Pu , Li Qizhi , Tang Wenye , Wang Weiqiang , Zhang Wenfu , Little Brent E. , Chu Sai Tek , Shore K. Alan , Qin Yuwen , Wang Yuncai 
Published: March 2024

AbstractRandom bit generators are critical for information security, cryptography, stochastic modeling, and simulations. Speed and scalability are key challenges faced by current physical random bit generation. Herein, we propose a massively parallel scheme for ultrafast random bit generation towards rates of order 100 terabit per second based on a single micro-ring resonator. A modulation-instability-driven chaotic comb in a micro-ring resonator enables the simultaneous generation of hundreds of independent and unbiased random bit streams. A proof-of-concept experiment demonstrates that using our method, random bit streams beyond 2 terabit per second can be successfully generated with only 7 comb lines. This bit rate can be easily enhanced by further increasing the number of comb lines used. Our approach provides a chip-scale solution to random bit generation for secure communication and high-performance computation, and offers superhigh speed and large scalability.
Deciphering the tumor immune microenvironment of imatinib-resistance in advanced gastrointestinal stromal tumors at single-cell resolution
Authors: Liu Xuechao , Yu Jing , Li Yi , Shi Hailei , Jiao Xuelong , Liu Xiaodong , Guo Dong , Li Zequn , Tian Yulong , Dai Fan , Niu Zhaojian , Zhou Yanbing 
Published: March 2024

AbstractThe heterogeneous nature of tumors presents a considerable obstacle in addressing imatinib resistance in advanced cases of gastrointestinal stromal tumors (GIST). To address this issue, we conducted single-cell RNA-sequencing in primary tumors as well as peritoneal and liver metastases from patients diagnosed with locally advanced or advanced GIST. Single-cell transcriptomic signatures of tumor microenvironment (TME) were analyzed. Immunohistochemistry and multiplex immunofluorescence staining were used to further validate it. This analysis revealed unique tumor evolutionary patterns, transcriptome features, dynamic cell-state changes, and different metabolic reprogramming. The findings indicate that in imatinib-resistant TME, tumor cells with activated immune and cytokine-mediated immune responses interacted with a higher proportion of Treg cells via the TIGIT-NECTIN2 axis. Future immunotherapeutic strategies targeting Treg may provide new directions for the treatment of imatinib-resistant patients. In addition, IDO1+ dendritic cells (DC) were highly enriched in imatinib-resistant TME, interacting with various myeloid cells via the BTLA-TNFRSF14 axis, while the interaction was not significant in imatinib-sensitive TME. Our study highlights the transcriptional heterogeneity and distinct immunosuppressive microenvironment of advanced GIST, which provides novel therapeutic strategies and innovative immunotherapeutic agents for imatinib resistance.
Frequency, kinetics and determinants of viable SARS-CoV-2 in bioaerosols from ambulatory COVID-19 patients infected with the Beta, Delta or Omicron variants
Authors: Jaumdally S. , Tomasicchio M. , Pooran A. , Esmail A. , Kotze A. , Meier S. , Wilson L. , Oelofse S. , van der Merwe C. , Roomaney A. , Davids M. , Suliman T. , Joseph R. , Perumal T. , Scott A. , Shaw M. , Preiser W. , Williamson C. , Goga A. , Mayne E. , Gray G. , Moore P. , Sigal A. , Limberis J. , Metcalfe J. , Dheda K. 
Published: March 2024

AbstractAirborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.
Reconciling ice core CO2 and land-use change following New World-Old World contact
Authors: King Amy C. F. , Bauska Thomas K. , Brook Edward. J. , Kalk Mike , Nehrbass-Ahles Christoph , Wolff Eric. W. , Strawson Ivo , Rhodes Rachael H. , Osman Matthew B. 
Published: March 2024

AbstractIce core records of carbon dioxide (CO2) throughout the last 2000 years provide context for the unprecedented anthropogenic rise in atmospheric CO2 and insights into global carbon cycle dynamics. Yet the atmospheric history of CO2 remains uncertain in some time intervals. Here we present measurements of CO2 and methane (CH4) in the Skytrain ice core from 1450 to 1700 CE. Results suggest a sudden decrease in CO2 around 1610 CE in one widely used record may be an artefact of a small number of anomalously low values. Our analysis supports a more gradual decrease in CO2 of 0.5 ppm per decade from 1516 to 1670 CE, with an inferred land carbon sink of 2.6 PgC per decade. This corroborates modelled scenarios of large-scale reorganisation of land use in the Americas following New World-Old World contact, whereas a rapid decrease in CO2 at 1610 CE is incompatible with even the most extreme land-use change scenarios.