bluuebunny/crossref_metadata_2025 huggingface dataset:
Ignition and deflagration-to-detonation transition modes in ethylene/air mixtures behind a reflected shock
Authors: Huang Zhiwei , Zhang Huangwei
Published: July 2022

Dynamics of ethylene autoignition and deflagration-to-detonation transition (DDT) are first numerically investigated in a one-dimensional shock tube using a reduced chemistry including 10 species and 10 reactions. Different combustion modes are investigated through considering various premixed gas equivalence ratios (0.2 − 2.0) and incident shock wave Mach numbers (1.8–3.2). Four ignition and DDT modes are observed from the studied cases, i.e., no ignition, deflagration combustion, detonation after reflected shock, and deflagration behind the incident shock. For detonation development behind the reflected shock, three autoignition hot spots are formed. The first one occurs at the wall surface after the re-compression of the reflected shock and contact surface, which further develops to a reaction shock because of “the explosion in the explosion” regime. The other two are off the wall, respectively, caused by the reflected shock/rarefaction wave interaction and reaction induction in the compressed mixture. The last hot spot develops to a reaction wave and couples with the reflected shock after a DDT process, which eventually leads to detonation combustion. For deflagration development behind the reflected shock, the wave interactions, wall surface autoignition hot spot as well as its induction of reaction shock are qualitatively similar to the mode of detonation after incident shock reflection, before the reflected shock/rarefaction wave collision point. However, only one hot spot is induced after the collision, which also develops to a reaction wave but cannot catch up with the reflected shock. For deflagration behind the incident shock, deflagration combustion is induced by the incident shock compression whereas detonation occurs after the shock reflection. The chemical timescale increases after the reflected shock/contact surface collision, whereas decreases behind the incident and reflected shocks, as well as after the reflected shock/rarefaction wave interaction. Therefore, mixture reactivity behind the reflected shock is weakened by the contact surface, but is intensified by the rarefaction wave. The multi-dimensionality characteristics, including reflected shock/boundary layer interactions, reflected shock bifurcation, destabilization, and detonation, are further present in a two-dimensional configuration. Planar autoignition occurs because of reflected shock compression and detonation combustion is formed first in the central region due to the collision of the reflected shock wave/reflected compression wave. The left and right bifurcations of the separation region in the wall boundary layer are then sequentially ignited.
Model of interfacial term in turbulent kinetic energy equation and computation of dissipation rate for particle-laden flows
Authors: Xia Yan , Yu Zhaosheng , Lin Zhaowu , Guo Yu
Published: July 2022

In this paper, we demonstrate that the original Troshko–Hassan model with the correction coefficient being unity should be chosen for an interfacial term in the turbulent kinetic energy equation at the statistically steady state based on the theoretical analysis and interface-resolved direct numerical simulations of the particle sedimentation in a periodic domain and an upward turbulent channel flow. In addition, the computational schemes for the viscous dissipation near the particle surface with the non-boundary-fitted mesh are examined, and the results show that the second-order single-sided differentiation for the velocity gradient at the fluid grids in the immediate vicinity of the particle surface can reduce the computational error significantly, compared to the two-sided differentiation.
Predicting the lifetimes of evaporating droplets in ordered arrays
Authors: Chen Hao , An Qiaoru , Zhang Hongya , Li Chengshuai , Fang Haisheng , Yin Zhouping
Published: July 2022

In many industrial processes, sessile droplets are well separated in an ordered array and evaporate to form various patterns. For an evaporating droplet in arrays, the presence of surrounding droplets causes a shielding effect that, in turn, leads to a decrease in the evaporation rate compared to the same droplet in isolation. Here, we demonstrate that, theoretically and experimentally, the shielding effect results in a significant increase in the lifetime of an evaporating droplet. Based on a recent theory, we determine the lifetimes of evaporating droplets in the ordered array. The theoretical prediction shows excellent agreement with our experimental data and even performs well outside its range of validity. These findings strengthen our fundamental understanding of interactions between evaporating droplets in arrays and provide new strategies for controlling the droplet evaporation.
Triple electron–electron–proton excitations and second-order approximations in nuclear–electronic orbital coupled cluster methods
Authors: Pavošević Fabijan , Hammes-Schiffer Sharon
Published: July 2022

The accurate description of nuclear quantum effects, such as zero-point energy, is important for modeling a wide range of chemical and biological processes. Within the nuclear–electronic orbital (NEO) approach, such effects are incorporated in a computationally efficient way by treating electrons and select nuclei, typically protons, quantum mechanically with molecular orbital techniques. Herein, we implement and test a NEO coupled cluster method that explicitly includes the triple electron–electron–proton excitations, where two electrons and one proton are excited simultaneously, using automatic differentiation. Our calculations show that this NEO-CCSDTeep method provides highly accurate proton densities and proton affinities, outperforming any previously studied NEO method. These examples highlight the importance of the triple electron–electron–proton excitations for an accurate description of nuclear quantum effects. Additionally, we also implement and test the second-order approximate coupled cluster with singles and doubles (NEO-CC2) method as well as its scaled-opposite-spin (SOS) versions. The NEO-SOS′-CC2 method, which scales the electron–proton correlation energy as well as the opposite-spin and same-spin components of the electron–electron correlation energy, achieves nearly the same accuracy as the NEO-CCSDTeep method for the properties studied. Because of its low computational cost, this method will enable a wide range of chemical and photochemical applications for large molecular systems. This work sets the stage for a variety of developments and applications within the NEO framework.
Wetlands as social ecological systems, and relationality in the policy domain
Authors: Horwitz Pierre
Published: July 2022

A wetland policy perspective based on social ecological systems accepts that wetlands are part of landwaterscapes, that people are part of wetland ecosystems, and that the health of wetlands and the health of people are interdependent, evidence of the close, reciprocal and indivisible relationships between nature and culture. These relationships are storied and place-based, associated with place attachment, and are representations of relational values. They are most easily located wherever and whenever Indigenous and local peoples’ knowledge and interests are at play in wetland settings. Legal and administrative processes that recognise Chthonic law and rights for wetlands will elevate relational values and provide the governance arrangements for their inclusion in wetland (and other ecosystem) management. Co-designing with Indigenous and local communities in developing wetland policies and operationalising practices will allow for wetland stories to be shared, respectfully cared for, and built into educational curricula and ecosystem valuation models. (Warning: this article contains the name of deceased Aboriginal person.)
Equity in primary health care: the legacy of Julian Tudor Hart and a personal journey he inspired
Authors: Goodyear-Smith Felicity
Published: July 2022

Dr Julian Tudor Hart inspired me when I worked as a locum general practitioner in the neighbouring village to Glyncorrwg, southern Wales, in 1979. Our conversations helped shape my subsequent career. But it was only years later I learned that Julian was an icon of general practice and author of the famous ‘inverse care law’. Julian was both a truly compassionate dedicated general practitioner in Glyncorrwg, an impoverished Welsh working-class coal-mining village, and an epidemiologist, conducting robust research in partnership with his patients. Patients were co-producers of the research designed to improve their health outcomes. Julian led the way in advocating that first-contact, continuous, comprehensive, and coordinated care for everyone was necessary to achieve equitable health outcomes. He conducted research neither for its own sake nor for his academic advancement. His aim was always to help improve people’s lives. He identified that good medical care was least likely to be available for populations most in need. More than that, he demonstrated throughout his exemplary career how it was possible to work with a socioeconomically disadvantaged community to both discover their health needs and also provide equitable personalised health care to all. His legacy lives on.
Adaptive laboratory evolution and independent component analysis disentangle complex vancomycin adaptation trajectories
Authors: Fait Anaëlle , Seif Yara , Mikkelsen Kasper , Poudel Saugat , Wells Jerry M. , Palsson Bernhard O. , Ingmer Hanne
Published: July 2022

Human infections with methicillin-resistantStaphylococcus aureus(MRSA) are commonly treated with vancomycin, and strains with decreased susceptibility, designated as vancomycin-intermediateS. aureus(VISA), are associated with treatment failure. Here, we profiled the phenotypic, mutational, and transcriptional landscape of 10 VISA strains adapted by laboratory evolution from one common MRSA ancestor, the USA300 strain JE2. Using functional and independent component analysis, we found that: 1) despite the common genetic background and environmental conditions, the mutational landscape diverged between evolved strains and included mutations previously associated with vancomycin resistance (invraT,graS,vraFG,walKR, andrpoBCD) as well as novel adaptive mutations (SAUSA300_RS04225,ssaA,pitAR, andsagB); 2) the first wave of mutations affected transcriptional regulators and the second affected genes involved in membrane biosynthesis; 3) expression profiles were predominantly strain-specific except forsceDandlukG, which were the only two genes significantly differentially expressed in all clones; 4) three independent virulence systems (φSa3, SaeR, and T7SS) featured as the most transcriptionally perturbed gene sets across clones; 5) there was a striking variation in oxacillin susceptibility across the evolved lineages (from a 10-fold increase to a 63-fold decrease) that also arose in clinical MRSA isolates exposed to vancomycin and correlated with susceptibility to teichoic acid inhibitors; and 6) constitutive expression of the VraR regulon explained cross-susceptibility, while mutations inwalKwere associated with cross-resistance. Our results show that adaptation to vancomycin involves a surprising breadth of mutational and transcriptional pathways that affect antibiotic susceptibility and possibly the clinical outcome of infections.
A Russian lesson for the twenty-first century
Authors: Sydorenko Sergiy
Published: July 2022

In 2019, Yuval Harari, an Israeli historian and bestselling author, appeared in the center of a media debate
provoked by the discovery of considerable differences between the English text of his 21 Lessons for the 21st
Century and its Russian translation. A comparative study of the English and Russian texts of the book featured in
this paper revealed five major issues which turned out to be sensitive for the Russian censorship, namely, homosexuality,
liberalism, U.S.S.R.–U.S. “tug-of-war,” Putin and Putin’s Russia, and Putin’s aggression against Ukraine and Georgia. It is in the
presentation of these topics that Yuval Harari’s English text suffered essential transformation and reduction in the Russian
edition. The conducted analysis contributes to the long-lived debate about the author’s and the translator’s responsibility before
their readers, and the boundaries, beyond which mutilation of the source text no longer allows regarding the resulting text as a
translation. The author argues that the escalating information wars targeted at people’s minds in the twenty-first century impose
ever-increasing requirements to authors and translators of such books as Yuval Harari’s 21 Lessons for the 21st
Century in terms of intellectual integrity and professional ethics.
The negative cycle in Chinese
Authors: Meisterernst Barbara
Published: July 2022

The present discussion proposes that renewal processes in the domain of negation manifest themselves predominantly in the change from bi-morphemic, synthetic negation to analytic negationneg+auxby introducing a new auxiliary verb as verbal head. Some of these new verbs may subsequently be merged with the negator resulting into new bi-morphemic negation. The proposed analyticization process accounts for different kinds of complex negation, including aspectual and modal negation, the copula and negative focus markers. I propose a unified mechanism for the morpho-syntactic processes, which change the system of negation in Chinese. Two morpho-syntactic factors contribute to this particular grammaticalization process of Chinese: (1) the diachronically consistent head initial word order within the functional and the lexical (CP/vP) domains (with the exception of sentence-final particles); and (2) the morpho-phonological rule that negation has to attach directly toaux, i.e., to a weak verbal head. Based on particularly the second constraint, I propose that only the combinationneg+auxmodleads to the emergence of new fused negators constituting the head of a Negative/Modal phrase, i.e., a negative phrase (NegP) with modal features. The renewal process of the verbal heads of bi-morphemic negation is caused by semantic bleaching and an increasing intransparency of the negator which triggers the grammaticalization of new (often defective) lexical verbs via upward movement from the lexical to the functional domain. It accounts for the grammaticalization of the aspectual negatorwèi未, of the (negative) copula of Early Archaic Chinese into focus marker and complementizer, and for the replacement of synthetic by analytic modal negationnegmod>neg+auxmod.
Gastrochilus wolongensis
(Orchidaceae): a new species from Sichuan, China, based on molecular and morphological data
Authors: Zhang Junyi , Cheng Yuehong , Liao Min , Jin Senlong , Qu Chunmao , Tan Yingchun , Plenković-Moraj Anđelka , Xu Bo
Published: July 2022

Gastrochilus wolongensis
(Orchidaceae), a new orchid species from Sichuan Province, Southwest China, is described and illustrated. It morphologically resembles
G. sinensis
, but differs markedly from the latter in having black-purple stripes (vs. purplish-red spots) on the adaxial side of the petals and sepals, a reniform epichile densely covered with long papillate hairs (vs. sparsely pubescent) with purplish-red spots (vs. unspotted), and outside the sac of the hypochile with purplish-red stripes (vs. purplish-red spotted). The molecular phylogenetic analysis based on nuclear ribosome internal transcribed spacer (nrITS) and four chloroplast DNA fragments (
mat
K,
psb
A-
trn
H,
psb
M-
trn
D, and
trn
L-F) of 36
Gastrochilus
species showed that
G. wolongensis
was closely related to
G. ciliaris
and
G. formosanus
.
Superconducting quantum interference effect in NbSe2/NbSe2 van der Waals junctions
Authors: Jian Yu , Feng Qi , Zhong Jinrui , Peng Huimin , Duan Junxi
Published: July 2022

Layered materials with exotic properties, such as superconducting, ferromagnetic, and so on, have attracted broad interest. The advances in van der Waals (vdW) stacking technology have enabled the fabrication of numerous types of junction structures. The dangling-bond-free interface provides an ideal platform to generate and probe various physics phenomena. Typical progress is the realization of vdW Josephson junctions with high supercurrent transparency constructed of two NbSe2 layers. Here we report the observation of periodic oscillations of the voltage drop across a NbSe2/NbSe2 vdW junctions under an in-plane magnetic field. The voltage-drop oscillations come from the interface and the magnitude of the oscillations has a non-monotonic temperature dependence which increases first with increasing temperature. These features make the oscillations different from the modulation of the critical current of a Josephson junction by the magnetic field and the Little–Parks effect. The oscillations are determined to be generated by the quantum interference effect between two superconducting junctions formed between the two NbSe2 layers. Our results thus provide a unique way to make an in-plane superconducting quantum interference device that can survive under a high magnetic field utilizing the Ising-paring nature of the NbSe2.
Novel polymeric phases proposed by cold-pressing SiC tubes
Authors: Wang Yuan-Yuan , Li Zhi-Hui , Liu Yuan-Yuan , Hu Kuo , Yao Zhen
Published: July 2022

A detailed structural evolution behavior of SiC single-wall nanotubes (SiC SWNTs) under high-pressure is studied by using density functional theory. We proposed four new polymeric phases (hP4-SiC, hP48-SiC, oI32-SiC and oA40-SiC), which possess the high stability, outstanding electronic and mechanical properties. The hP4-SiC, hP48-SiC and oA40-SiC are indirect band gap semiconductors, while the oI32-SiC is direct band gap semiconductor. The exhibited suitable band gap (∼3.1 eV) allows hP4-SiC, hP48-SiC, oI32-SiC and oA40-SiC as the potential blue-laser diodes materials. The Si–C bond in four new structures is the strong covalent bond in sp3 hybridization, which results in their high stability and hardness. The exhibited high decomposition temperature and high hardness make them as the potential high temperature abrasive materials. The stacking way of different rings in structures and atomic arrangement configurations of C and Si atoms in rings induce the anisotropic stiffness of polymeric structures. The analysis of x-ray diffraction, Raman and infrared radiation spectra is performed for a guideline of their synthesis in experiment. These results would help to understand the structural evolution of SiC SWNTs under high pressure and contribute to develop the high hardness and temperature materials.
Feasibility of triple gamma ray imaging of 10C for range verification in ion therapy
Authors: Mohammadi Akram , Tashima Hideaki , Takyu Sodai , Iwao Yuma , Akamatsu Go , Kang Han Gyu , Obata Fujino , Nishikido Fumihiko , Parodi Katia , Yamaya Taiga
Published: July 2022

Objective. In carbon ion therapy, the visualization of the range of incident particles in a patient body is important for treatment verification. In-beam positron emission tomography (PET) imaging is one of the methods to verify the treatment in ion therapy due to the high quality of PET images. We have shown the feasibility of in-beam PET imaging of radioactive 15O and 11C ion beams for range verification using our OpenPET system. Recently, we developed a whole gamma imager (WGI) that can simultaneously work as PET, single gamma ray and triple gamma ray imaging. The WGI has high potential to detect the location of 10C, which emits positrons with a simultaneous gamma ray of 718 keV, within the patient’s body during ion therapy. Approach. In this work, we focus on investigating the performance of WGI for 10C imaging and its feasibility for range verification in carbon ion therapy. First, the performance of the WGI was studied to image a 10C point source using the Geant4 toolkit. Then, the feasibility of WGI was investigated for an irradiated polymethyl methacrylate (PMMA) phantom with a 10C ion beam at the carbon therapy facility of the Heavy Ion Medical Accelerator in Chiba. Main results. The average spatial resolution and sensitivity for the simulated 10C point source at the centre of the field of view were 5.5 mm FWHM and 0.010%, respectively. The depth dose of the 10C ion beam was measured, and the triple gamma image of 10C nuclides for an irradiated PMMA phantom was obtained by applying a simple back projection to the detected triple gammas. Significance. The shift between Bragg peak position and position of the peak of the triple gamma image in an irradiated PMMA phantom was 2.8 ± 0.8 mm, which demonstrates the capability of triple gamma imaging using WGI for range verification of 10C ion beams.
Selected topics in diffraction with protons and nuclei: past, present, and future
Authors: Frankfurt L , Guzey V , Stasto A , Strikman M
Published: July 2022

We review a broad range of phenomena in diffraction in the context of hadron–hadron, hadron–nucleus collisions and deep inelastic lepton–proton/nucleus scattering focusing on the interplay between the perturbative QCD and non-perturbative models. We discuss inclusive diffraction in DIS, phenomenology of dipole models, resummation and parton saturation at low x, hard diffractive production of vector mesons, inelastic diffraction in hadron–hadron scattering, formalism of color fluctuations, inclusive coherent and incoherent diffraction as well as soft and hard diffraction phenomena in hadron–hadron/nucleus and photon–nucleus collisions. For each topic we review key results from the past and present experiments including HERA and the LHC. Finally, we identify the remaining open questions, which could be addressed in the continuing experiments, in particular in photon-induced reactions at the LHC and the future electron–ion collider in the US, large hadron electron collider and future circular collider at CERN.
Highly sensitive spherical cap structure-based iontronic pressure sensors by a mold-free fabrication approach
Authors: Tang Yifeng , Zhang Tieshan , Ren Hao , Zhang Wei , Li Gen , Guo Dong , Yang Liu , Tan Rong , Shen Yajing
Published: July 2022

The hemispherical structure has been widely adopted for pressure sensor design owing to its predictable and robust architecture. However, limited to the low deformation ability of hemispherical structures under pressure, the sensitivity of such sensor is relatively low, making it not effective when detecting tiny pressure changes. Herein, we investigate the relationship between the general spherical cap structure (SCS) and sensor sensitivity by developing a mathematical model and finite element analysis, and theoretically elucidate that SCS with smaller contact angles could bring higher sensor sensitivity. Then, we fabricate the iontronic pressure sensors from SCS with different contact angles by proposing a mold-free fabrication approach. The experimental results verify that SCS with smaller contact angles can significantly improve the sensor sensitivity while keeping the advantages of the classic hemispherical structure. For instance, the SCS sensor with 30° contact angle exhibits a maximum sensitivity (100 nF kPa−1) under small pressure (1 Pa), which is five-fold higher than the sensors using the traditional hemispherical structure. This study paves an effective and easy way to improve the performance of traditional hemispherical structure-based pressure sensors, and this strategy could also benefit other kinds of highly sensitive sensor design.
Stable ferromagnetism and high Curie temperature in VGe2N4
Authors: Li Yingmei , Liu Yong
Published: July 2022

The discovery of monolayer MA2Z4 (M = transition metals; A = IVA elements; Z = VA elements) [Hong et al 2020 Science
369 670] family has led another advance for facilitating and harnessing magnetism in low-dimensional materials. However, only Cr and V based MA2N4 compounds exhibit intrinsic magnetism yet with unsatisfied magnetic ordering temperature. Herein, we identify a stable ferromagnetic number of this family, i.e., VGe2Z4 monolayer, by means of first-principles calculations. It is found that the magnetic configuration sustains under both compression and tensile uniaxial in-plane strain, and the former can act as a positive modulator to enhance magnetic ordering temperature (T
C). Electronic structure calculations reveal a large band gap in the spin down channel while band-gapless in the spin up channel, an impressive near-half-metallic character, which is a favorable candidate for spintronic device.
Dependence of scrape-off layer profiles and turbulence on gas fuelling in high density H-mode regimes in TCV
Authors: Stagni A. , Vianello N. , Tsui C.K. , Colandrea C. , Gorno S. , Bernert M. , Boedo J.A. , Brida D. , Falchetto G. , Hakola A. , Harrer G. , Reimerdes H. , Theiler C. , Tsitrone E. , Walkden N. , the TCV Team  , the EUROfusion MST1 Team
Published: July 2022

A set of high density, highly shaped H-mode discharges has been performed in the TCV tokamak with the aim of assessing the effects of increasing divertor neutral recycling on the properties of upstream inter-ELM scrape-off layer (SOL) profiles and transport. An increase of divertor neutral pressure has been correlated with the evolution of separatrix properties and turbulence level. The latter has been quantified by means of the α
t parameter introduced in (Eich 2020 Nucl. Fusion
60 056016), describing the contribution of resistive-interchange turbulence in the SOL relative to drift wave transport. The analysis reveals a general broadening of the upstream SOL profiles as α
t increases, with the SOL power width measured by the vertical IR thermography system increasing significantly. In a similar way, the upstream density profile widens in the near SOL, whereas in the far SOL a density shoulder is observed to progressively form and increase in amplitude. This behaviour is associated with an enhancement of far SOL turbulent transport in the form of blob-filaments travelling radially faster across the far SOL and becoming bigger at higher α
t. The detected filaments, evaluated from the fast reciprocating probe at the outer midplane, are determined to mostly belong to the resistive ballooning and resistive X-point regimes.
Do distylous syntopic plant species partition their floral morphological traits?
Authors: Cardoso João Custódio Fernandes , Trevizan Renata , Matallana-Puerto Carlos Andres , Gonçalves Rogério Victor , Oliveira Paulo Eugênio , Coelho Christiano Peres , Matias Raphael
Published: July 2022

Morphological niche partitioning between related syntopic plants that are distylous (with short- and long-styled morphs) is complex. Owing to differences in the heights of stigmas and anthers, each floral morph must place pollen onto two distinct parts of the body of the pollinator. This led us to hypothesize that such partitioning should be more accurate among distylous syntopic species in comparison to combinations with other related plants that do not co-occur. We tested these assumptions using a set of Palicourea (Rubiaceae) species as a model system. We compared the distribution, flowering phenology, floral measurements and reciprocity of sexual organ heights of two syntopic species (Palicourea rigida and Palicourea coriacea) and one non-syntopic congener (Palicourea marcgravii). The three species overlapped in their distributions and flowering periods. The position of sexual organs was, in most cases, partitioned between syntopic populations, with low overlap in anther and stigma heights. However, we found a higher overlap involving the non-syntopic species, especially between Palicourea rigida and Palicourea marcgravii. Additionally, reciprocity of sexual organs was more accurate in intraspecific inter-morph combinations (i.e. legitimate organ correspondence) in comparison to intraspecific intra-morph, interspecific syntopic and interspecific non-syntopic combinations. The partitioning of morphological traits between syntopic species might facilitate the differential placement of pollen on the body of the pollinator and reduce the chances of interspecific interference.
Alleviating spatial confounding in frailty models
Authors: Azevedo Douglas R M , Prates Marcos O , Bandyopadhyay Dipankar
Published: July 2022

The confounding between fixed effects and (spatial) random effects in a regression setup is termed spatial confounding. This topic continues to gain attention and has been studied extensively in recent years, given that failure to account for this may lead to a suboptimal inference. To mitigate this, a variety of projection-based approaches under the class of restricted spatial models are available in the context of generalized linear mixed models. However, these projection approaches cannot be directly extended to the spatial survival context via frailty models due to dimension incompatibility between the fixed and spatial random effects. In this work, we introduce a two-step approach to handle this, which involves (i) projecting the design matrix to the dimension of the spatial effect (via dimension reduction) and (ii) assuring that the random effect is orthogonal to this new design matrix (confounding alleviation). Under a fully Bayesian paradigm, we conduct fast estimation and inference using integrated nested Laplace approximation. Both simulation studies and application to a motivating data evaluating respiratory cancer survival in the US state of California reveal the advantages of our proposal in terms of model performance and confounding alleviation, compared to alternatives.
Understanding Spatiotemporal Human Mobility Patterns for Malaria Control Using a Multiagent Mobility Simulation Model
Authors: Li Yao , Stewart Kathleen , Han Kay Thwe , Han Zay Yar , Aung Poe P , Thein Zaw W , Htay Thura , Chen Dong , Nyunt Myaing M , Plowe Christopher V
Published: July 2022

Background

More details about human movement patterns are needed to evaluate relationships between daily travel and malaria risk at finer scales. A multiagent mobility simulation model was built to simulate the movements of villagers between home and their workplaces in 2 townships in Myanmar.

Methods

An agent-based model (ABM) was built to simulate daily travel to and from work based on responses to a travel survey. Key elements for the ABM were land cover, travel time, travel mode, occupation, malaria prevalence, and a detailed road network. Most visited network segments for different occupations and for malaria-positive cases were extracted and compared. Data from a separate survey were used to validate the simulation.

Results

Mobility characteristics for different occupation groups showed that while certain patterns were shared among some groups, there were also patterns that were unique to an occupation group. Forest workers were estimated to be the most mobile occupation group, and also had the highest potential malaria exposure associated with their daily travel in Ann Township. In Singu Township, forest workers were not the most mobile group; however, they were estimated to visit regions that had higher prevalence of malaria infection over other occupation groups.

Conclusions

Using an ABM to simulate daily travel generated mobility patterns for different occupation groups. These spatial patterns varied by occupation. Our simulation identified occupations at a higher risk of being exposed to malaria and where these exposures were more likely to occur.
Up the stairs, down in the elevator? The asymmetric response of emerging market currencies to the global liquidity cycle
Authors: Macalós João Pedro Scalco , Rossi Pedro
Published: July 2022

This paper assesses whether there is evidence of an asymmetric relationship between the global liquidity cycle and the currencies of developing and emerging economies (DEEs), a central tenet of the Minskyan interpretation of the exchange rate behaviour in these economies and the ‘financialisation in developing and emerging economies’ literature. We use a novel panel model technique that incorporates asymmetric components to fixed-effects regressions to check if there is evidence of such asymmetry. Our results suggest that capital flows, commodity prices and the VIX have a more substantial relationship with the currencies of DEEs during the retrenchment of the global liquidity cycle than during its expansionist phase. In other words, our results suggest that the currencies of DEEs take the stairs up and the elevator down.
Oesophageal safety in voltage-guided atrial fibrillation ablation using ablation index or contact force only: a prospective comparison
Authors: Schade Anja , Costello-Boerrigter Lisa , Deneke Thomas , Steinborn Frank , Chapran Mykhaylo , Vathie Koroush , Milisavljevic Nemanja , Franz Marcus , Surber Ralf , Assani Mohamad , Hamo Hussam , Khshfeh Muhammed , Lauten Alexander , Mattea Violeta
Published: July 2022

Aims

Left atrial ablation using radiofrequency (RF) is associated with endoscopically detected thermal oesophageal lesions (EDELs). The aim of this study was to compare EDEL occurrence after conventional contact force-guided (CFG) RF ablation vs. an ablation index-guided (AIG) approach in clinical routine of voltage-guided ablation (VGA). Predictors of EDEL were also assessed.

Methods and results

This study compared CFG (n = 100) with AIG (n = 100) in consecutive atrial fibrillation ablation procedures, in which both pulmonary vein isolation and VGA were performed. In the AIG group, AI targets were ≥500 anteriorly and ≥350–400 posteriorly. Upper endoscopy was performed after ablation.The CFG and AIG groups had comparable baseline characteristics. The EDEL occurred in 6 and 5% (P = 0.86) in the CFG and AIG groups, respectively. Category 2 lesions occurred in 4 and 2% (P = 0.68), respectively. All EDEL healed under proton pump inhibitor therapy. The AI > 520 was the only predictor of EDEL [odds ratio (OR) 3.84; P = 0.039]. The more extensive Category 2 lesions were predicted by: AI max > 520 during posterior ablation (OR 7.05; P = 0.042), application of posterior or roof lines (OR 5.19; P = 0.039), existence of cardiomyopathy (OR 4.93; P = 0.047), and CHA2DS2-VASc score (OR 1.71; P = 0.044). The only Category 2 lesion with AI max < 520 (467) occurred in a patient with low body mass index.

Conclusions

Both methods were comparable with respect to clinical complications and EDEL. In consideration of previous reconnection data and our study results regarding oesophageal safety, optimal AI target range might be between 400 and 450.
An evaluation of 24 h Holter monitoring in patients with myotonic dystrophy type 1
Authors: Joosten Isis B T , Janssen Cheyenne E W , Horlings Corinne G C , den Uijl Dennis , Evertz Reinder , van Engelen Baziel G M , Faber Catharina G , Vernooy Kevin
Published: July 2022

Aims

To evaluate the clinical effectiveness of routine 24 h Holter monitoring to screen for conduction disturbances and arrhythmias in patients with myotonic dystrophy type 1 (DM1).

Methods and results

A retrospective two-centre study was conducted including DM1-affected individuals undergoing routine cardiac screening with at least one 24 h Holter monitoring between January 2010 and December 2020. For each individual, the following data were collected: Holter results, results of electrocardiograms (ECGs) performed at the same year as Holter monitoring, presence of cardiac complaints, and neuromuscular status. Holter findings were compared with the results of cardiac screening (ECG + history taking) performed at the same year. Cardiac conduction abnormalities and/or arrhythmias that would have remained undiagnosed based on history taking and ECG alone were considered de novo findings. A total 235 genetically confirmed DM1 patients were included. Abnormal Holter results were discovered in 126 (54%) patients after a mean follow-up of 64 ± 28 months in which an average of 3 ± 1 Holter recordings per patient was performed. Abnormalities upon Holter mainly consisted of conduction disorders (70%) such as atrioventricular (AV) block. Out of 126 patients with abnormal Holter findings, 74 (59%) patients had de novo Holter findings including second-degree AV block, atrial fibrillation/flutter and non-sustained ventricular tachycardia. Patient characteristics were unable to predict the occurrence of de novo Holter findings. In 39 out of 133 (29%) patients with normal ECGs upon yearly cardiac screening, abnormalities were found on Holter monitoring during follow-up.

Conclusion

Twenty-four hour Holter monitoring is of added value to routine cardiac screening for all DM1 patients.
Distinct spectral dynamics of implanted cardiac defibrillator signals in spontaneous termination of polymorphic ventricular tachycardia and fibrillation in patients with electrical and structural diseases
Authors: Calvo David , Salinas Lucia , Martínez-Camblor Pablo , García-Iglesias Daniel , Alzueta Javier , Rodríguez Anibal , Romero Rafael , Viñolas Xavier , Fernández-Lozano Ignacio , Anguera Ignasi , Villacastín Julián , Bodegas Andrés , Fontenla Adolfo , Jalife José , Berenfeld Omer
Published: July 2022

Aims

To determine the spectral dynamics of early spontaneous polymorphic ventricular tachycardia and ventricular fibrillation (PVT/VF) in humans.

Methods and results

Fifty-eight self-terminated and 173 shock-terminated episodes of spontaneously initiated PVT/VF recorded by Medtronic implanted cardiac defibrillators (ICDs) in 87 patients with various cardiac pathologies were analyzed by short fast Fourier transform of shifting segments to determine the dynamics of dominant frequency (DF) and regularity index (RI). The progression in the intensity of DF and RI accumulations further quantified the time course of spectral characteristics of the episodes. Episodes of self-terminated PVT/VF lasted 8.6 s [95% confidence interval (CI): 8.1–9.1] and shock-terminated lasted 13.9 s (13.6–14.3) (P < 0.001). Recordings from patients with primarily electrical pathologies displayed higher DF and RI values than those from patients with primarily structural pathologies (P < 0.05) independently of ventricular function or antiarrhythmic drug therapy. Regardless of the underlying pathology, the average DF and RI intensities were lower in self-terminated than shock-terminated episodes [DF: 3.67 (4.04–4.58) vs. 4.32 (3.46–3.93) Hz, P < 0.001; RI: 0.53 (0.48–0.56) vs. 0.63 (0.60–0.65), P < 0.001]. In a multivariate analysis controlled by the type of pathology and clinical variables, regularity remained an independent predictor of self-termination [hazard ratio: 0.954 (0.928–0.980)]. Receiver operating characteristic (ROC) curve analysis of DF and RI intensities demonstrated increased predictability for self-termination in time with 95% CI above the 0.5 cut-off limit at about t = 8.6 s and t = 6.95 s, respectively.

Conclusion

Consistent with the notion that fast organized sources maintain PVT/VF in humans, reduction of frequency and regularity correlates with early self-termination. Our findings might help generate ICD methods aiming to reduce inappropriate shock deliveries.
Catheter ablation for patients with atrial fibrillation and heart failure with reduced and preserved ejection fraction: insights from the KiCS-AF multicentre cohort study
Authors: Shiraishi Yasuyuki , Kohsaka Shun , Ikemura Nobuhiro , Kimura Takehiro , Katsumata Yoshinori , Tanimoto Kojiro , Suzuki Masahiro , Ueda Ikuko , Fukuda Keiichi , Takatsuki Seiji
Published: July 2022

Aims

The usefulness of catheter ablation (CA) for atrial fibrillation (AF) across a broad spectrum of heart failure (HF) patients remains to be established. We assessed the association of CA with both health-related quality of life (QoL) and cardiovascular events among HF patients with reduced and preserved left ventricular ejection fraction (LVEF) in an ‘all-comer’ outpatient-based AF registry.

Methods and results

Of 3303 patients with AF consecutively enrolled in a retrospective multicentre registry that mandated the Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) questionnaire at registration and 1-year follow-up, we extracted data from 530 patients complicating clinical HF. The association between CA and both 1-year change in AFEQT Overall Summary (AFEQT-OS) scores and 2-year composite clinical outcomes (including all-cause death, stroke, and HF hospitalization) was assessed by multivariable analyses. The median duration of AF was 108 days (52–218 days), and 83.4% had LVEF >35%. Overall, 75 patients (14.2%) underwent CA for AF within 1-year after registration. At 1-year follow-up, 67.2% in the ablation group showed clinically meaningful improvements of ≥ 5 points in AFEQT-OS score than 47.8% in the non-ablation group {adjusted odds ratio, 2.03 [95% confidence interval (CI): 1.13–3.64], P = 0.017}. Furthermore, the composite endpoint of all-cause death, stroke, and HF hospitalization occurred less frequently in the ablation group than the non-ablation group [adjusted hazard ratio, 0.27 (95% CI: 0.09–0.86), P = 0.027].

Conclusion

Among AF-HF patients, CA was associated with improved QoL and lower risk of cardiovascular events against drug therapy alone, even for patients with mildly reduced and preserved LVEF.
Characterization of circumferential antral pulmonary vein isolation areas resulting from pulsed-field catheter ablation
Authors: Bohnen Marius , Weber Reinhold , Minners Jan , Jadidi Amir , Eichenlaub Martin , Neumann Franz-Josef , Arentz Thomas , Lehrmann Heiko
Published: July 2022

Aims

The cornerstone of pulmonary vein (PV) isolation (PVI) is a wide-area circumferential ablation (WACA) resulting in an antral PVI area. Pulsed-field ablation (PFA) is a new nonthermal ‘single-shot’ PVI technique resulting in well-characterized posterior isolation areas. However, information on circumferential PVI area is lacking. Thus, we sought to characterize the circumferential antral PVI areas after PFA-PVI.

Methods and results

Atrial fibrillation (AF) patients underwent fluoroscopy-guided PVI with a pentaspline PFA catheter. Ultra-high-density voltage maps using a 20-polar circular mapping catheter were created before and immediately after PVI to identify and quantify (i) insufficient isolation areas per antral PV segment (10-segment model) and (ii) enlarged left atrial (LA) isolation areas (beyond the antral PV segments) per LA region (8-region model). The PFA-PVI with pre- (5469 ± 1822 points) and post-mapping (6809 ± 2769 points) was performed in 40 consecutive patients [age 62 ± 6 years, 25/40 (62.5%) paroxysmal AF]. Insufficient isolation areas were located most frequently in the anterior antral PV segments of the left PVs (62.5–77.5% of patients) with the largest extent (median ≥0.4 cm2) located in the same segments (segments 2/5/8). Enlarged LA isolation areas were located most frequently and most extensively on the posterior wall and roof region (89.5–100% of patients; median 1.1–2.7 cm2 per region).

Conclusion

Fluoroscopy-guided PFA-PVI frequently results in insufficient isolation areas in the left anterior antral PV segments and enlarged LA isolation areas on the posterior wall/roof, which both may be extensive. To optimize the procedure, full integration of PFA catheter visualization into three-dimensional-mapping systems is needed.
Prognostic value of P-wave morphology in general population
Authors: Laitinen Idamaria , Kenttä Tuomas V , Passi Jussi , Haukilahti Mira Anette E , Eranti Antti , Holkeri Arttu , Aro Aapo L , Kerola Tuomas , Noponen Kai , Seppänen Tapio , Rissanen Harri , Knekt Paul , Heliövaara Markku , Ukkola Olavi H , Junttila M Juhani , Huikuri Heikki V , Perkiömäki Juha S
Published: July 2022

Aims

To evaluate the prognostic significance of novel P-wave morphology descriptors in general population.

Methods and results

Novel P-wave morphology variables were analyzed from orthogonal X-, Y-, Z-leads of the digitized electrocardiogram using a custom-made software in 6906 middle-aged subjects of the Mini-Finland Health Survey. A total of 3747 (54.3%) participants died during the follow-up period of 24.3 ± 10.4 years; 379 (5.5%) of the study population succumbed to sudden cardiac death (SCD), 928 (13.4%) to non-SCD (NSCD) and 2440 (35.3%) patients to non-cardiac death (NCD). In univariate comparisons, most of the studied P-wave morphology parameters had a significant association with all modes of death (P from <0.05 to <0.001). After relevant adjustments in the Cox multivariate hazards model, P-wave morphology dispersion (PMD) still tended to predict SCD [hazard ratio (HR): 1.006, 95% confidence interval (CI): 1.000–1.012, P = 0.05) but not NSCD (HR: 0.999, 95% CI: 0.995–1.003, P = 0.68) or NCD (HR: 0.999, 95% CI: 0.997–1.001, P = 0.44). The P-wave maximum amplitude in the lead Z (P-MaxAmp-Z) predicted SCD even after multivariate adjustments (HR: 1.010, 95% CI: 1.005–1.015, P = 0.0002) but also NSCD (HR: 1.005, 95% CI: 1.002–1.009, P = 0.0005) and NCD (HR: 1.002, 95% CI: 1.000–1.005, P = 0.03).

Conclusion

Abnormalities of P-wave morphology are associated with the risk of all modes of death in general population. After relevant adjustments, PMD was still closely associated with the risk of SCD but not with NSCD or NCD. P-MaxAmp-Z predicted SCD even after adjustments, however, it also retained its association with NSCD and NCD.
A synergistic arrangement of two unrelated IS elements facilitates adjacent deletion in Micrococcus luteus ATCC49732
Authors: Barker David F
Published: July 2022

Mutants of Micrococcus luteus strain ATCC49732 lacking the yellow pigment sarcinaxanthin were observed at an unexpectedly high frequency and the molecular basis was investigated. PCR probing revealed complete deletion of the crt biosynthetic operon in 11/14 mutants. Inverse PCR was used to identify a common breakpoint 35 kb downstream from crt precisely at the end of the right inverted repeat (IRR) of a partial ISMlu8 element that lies between two inversely oriented full-length ISMlu2. A total of three different breakpoints 5′ to crt were found with the sequence CTAG one bp 5′ to each novel junction. Analysis of 35 genomic sites with single ISMlu8 insertions showed that ISMlu8 transposase has high specificity for CTAG, implicating its key role in formation of the Δcrt deletions. No downstream deletion endpoints were observed at an immediately adjacent ISMlu8 with a nearly identical IRR in the same orientation and slightly closer to the crt operon, indicating that access of ISMlu8 transposase to the ISMlu2-flanked ISMlu8 IRR is greatly enhanced by the surrounding oppositely oriented ISMlu2s. The association of high frequency genomic rearrangement with this distinctive natural configuration of ISs from two different IS families offers a new insight into IS element evolutionary potential.