Presence Of Potential Research Articles

Two-particle transverse momentum correlations in pp and p -Pb collisions at energies available at the CERN Large Hadron Collider

Two-particle transverse momentum differential correlators, recently measured in Pb--Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at $\sqrt{s} = 7$ TeV and $\sqrt{s_{\rm NN}} = 5.02$ TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p--Pb to Pb--Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed.

Tracing the spatial organization and activity zones of an Early Mediaeval homestead at the Pohansko stronghold (Czechia) by combining geophysics and geochemical mapping

AbstractGeoarchaeological prospection techniques were applied to identify activity zones and the inner structure of a homestead at the Early Mediaeval site Pohansko near Břeclav (Czechia). By a combination of geophysical methods, the spatial distribution of microartefacts, geochemical analysis and multivariate statistical analysis, we outlined various manifestations of anthropogenic activity. We examined obtained data by Spearman's correlation coefficient, spatial autocorrelation (Global Moran's I) and robust Principal component analysis to identify the spatial pattern of the area. Recognized joint presence of heavy metals (Pb, Zn and Cu) and elements related mostly to organic matter, waste and ashes (S, P and Ca) as well as a small number of slag fragments probably indicate presence of metalworking zones or mixed zones with domestic and industrial debris at the homestead. Further anthropogenic activities could be connected to manuring, animal management or some kind of production activities based on the presence of Mn, P and Cu. Bone and charcoal concentrations supplement the information of geochemical analysis and may indicate the manner of waste management in the peripheral parts of the homestead. In the middle of the homestead, the location of archaeological features indicates an open space in which no specific activity was detected. By means of magnetic susceptibility and judging from the presence of daub, we defined the potential presence of non‐sunken features, which were not recognized by magnetometry. The outcome of the study is yet to be verified by excavation.

Stock Discrimination of Gilthead Seabream (Sparus aurata Linnaeus, 1758) through the Examination of Otolith Morphology and Genetic Structure

Reliable stock identification constitutes an integral component of effective fishery management. Current methods for the identification of putative stock units comprise the analysis of both phenotypic and genetic variability. The present study examined the spatial variation in otolith morphology (shape and asymmetry) and genetic composition of 395 wild-caught Gilthead seabream (Sparus aurata) specimens, collected from the Aegean and Ionian Seas (eastern Mediterranean) between 2014–2018. The degree of scale regeneration (SRD, % of regenerated scales) was used as an indicator to assess the potential presence of aquaculture escapees in the wild-caught samples. Otolith shape and asymmetry analyses showed a phenotypic discrimination between northwestern Aegean and Ionian Gilthead seabream populations. Genetic analyses of nine microsatellite markers revealed higher levels of genetic variation in the wild compared with samples obtained from aquaculture farms. Despite the absence of genetic structure among the wild-caught seabream populations, a low but statistically significant genetic differentiation was found between reared fish and fish collected in the field. The SRD was considered effective in detecting the presence of aquaculture escapees that may have escaped in either early or late rearing phases.

Osseous variations associated with physiological thinning of the glenoid articular cartilage: an osteological study with CT, MRI and arthroscopic correlations

ObjectiveTo investigate the relationship between osseous variations of the glenoid fossa and thinning of the overlaying articular cartilage.Materials and methodsIn total, 360 dry scapulae, comprising adult, children and fetal specimens, were observed for potential presence of osseous variants inside the glenoid fossa. Subsequently, the appearance of the observed variants was evaluated using CT and MRI (each 300 scans), and in-time arthroscopic findings (20 procedures). New terminology of the observed variants was proposed by an expert panel formed by orthopaedic surgeons, anatomists and radiologists.ResultsTubercle of Assaky was observed in 140 (46.7%) adult scapulae, and an innominate osseous depression was identified in 27 (9.0%) adult scapulae. Upon radiological imaging, the tubercle of Assaky was found in 128 (42.7%) CTs and 118 (39.3%) MRIs, while the depression was identified in 12 (4.0%) CTs and 14 (4.7%) MRIs. Articular cartilage above the osseous variations appeared relatively thinner and in several young individuals was found completely absent. Moreover, the tubercle of Assaky featured an increasing prevalence with aging, while the osseous depression develops in the second decade. Macroscopic articular cartilage thinning was identified in 11 (55.0%) arthroscopies. Consequently, four new terms were invented to describe the presented findings.ConclusionPhysiological articular cartilage thinning occurs due to the presence of the intraglenoid tubercle or the glenoid fovea. In teenagers, the cartilage above the glenoid fovea may be naturally absent. Screening for these variations increases the diagnostic accuracy of glenoid defects. In addition, implementing the proposed terminological updates would optimize communication accuracy.

Microbiological profiling and knowledge of food preservation technology to support guidance on a neutropenic diet for immunocompromised patients.

The current society consists of an increasing number of people vulnerable to infections. For certain people with severe immunodeficiency, a neutropenic or low-microbial diet is being prescribed, which substitutes high-risk foods that are more likely to contain human (opportunistic) pathogens with lower-risk alternatives. These neutropenic dietary guidelines are typically set up from a clinical and nutritional perspective, rather than from a food processing and food preservation perspective. In this study, the current guidelines in use by the Ghent University Hospital were evaluated based on the current knowledge of food processing and preservation technologies and the scientific evidence on microbiological quality, safety, and hygiene of processed foods. Three criteria are identified to be important: (1) the microbial contamination level and composition; (2) the potential presence of established foodborne pathogens such as Salmonella spp. (to which a zero-tolerance policy is recommended); and (3) an increased vigilance for L. monocytogenes as an opportunistic foodborne pathogen with a high mortality rate in immunocompromised individuals (to which a zero-tolerance policy should apply). A combination of these three criteria was used as a framework for the evaluation of the suitability of foodstuffs to be included in a low-microbial diet. Differences in processing technologies, initial contamination of products, etc., however, lead to a high degree of variability in microbial contamination and make it difficult to unambiguously accept or reject a certain type of foodstuff without prior knowledge of the ingredients and the processing and preservation technologies applied during manufacturing and subsequent storage conditions. A restricted screening on a selection of (minimally processed) plant-based foodstuffs on the retail market in Flanders, Belgium supported decision-making on the inclusion of these food types in a low-microbial diet. Still, when determining the suitability of a foodstuff to be included in a low-microbial diet, not only the microbiological status but also nutritional and sensorial properties should be assessed, which requires multidisciplinary communication and collaboration.

Prognosis of patients undergoing catheter ablation of arrhythmic storm in patients with and without history of previous ICD interventions

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation (CA) improves prognosis in patients with electrical storm (ES). However, its effectiveness and timing in patients with ventricular tachycardia and appropriate ICD therapies remain a matter of debate. Purpose Our aim was to investigate whether patients with history of discrete ventricular tachycardia episodes had different clinical features and outcome compared to patients with ES as first arrhythmic occurrence. Methods We enrolled 57 consecutive patients undergoing CA for ES and collected clinical, echocardiographic and electroanatomic mapping data. The primary end point was a composite of death from any cause and recurrences of sustained VT or ventricular fibrillation, appropriate ICD therapy, or ES. Results During a median follow up of 39 months, 28 patients (49%) met the primary end point of arrhythmic recurrence or death from any cause. There were no significant differences between clinical, electrocardiographic and echocardiographic parameters in the two groups. Regarding ICD therapies, patients with who met the primary end point had a higher number of ATP/shock episodes preceding the ES event: 15 (52%) vs 25 (89%), p=0.002. At Cox regression analysis, NIDCM, previous ATP and/or shock and ≥3 ATP were associated with arrhythmic recurrences and/or death. At multivariate analysis, ≥3 ATP was the only predictor that met statistical significance for the primary end point: HR was 30.41, CI 4.42 – 209.12, p=0.001. When dividing our population in patients and without ventricular arrhythmias (VAs) with appropriate device intervention before ES, thoses with VAs arrhythmias before ES had a higher percentage of presence of late potentials (80% vs 55%, p=0.041) and a greater unipolar scar (59.2±41.6 vs 30.2±21.6, p=0.001). At univariate analysis the presence of late potentials was associated with ventricular arrhythmias before ES (OR 3.33, CI 1.03-10.84, p=0.045). Conclusions CA in patients with a long arrhythmia history, recurrent ICD therapies and presence of late potentials at electroanatomic mapping, may yield worse outcomes and therefore our results support an early referral for CA of VT to improve prognosis in these subjects.

Association between left ventricular wall-thickness by CT and endocardial voltage potentials in patients with ischemic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Although cardiac magnetic resonance (CMR) is the gold standard for planning ventricular tachycardia (VT) ablation, its accuracy is hindered in patients with implanted cardiac defibrillators (ICD) and resynchronization therapy (CRT). Cardiac computed tomography (CT) has emerged as an alternative for ablation planning in these patients. This pilot study aimed to evaluate the relationship between wall thickness (WT) on CT and voltage of electrical potentials on endocardial electroanatomic mapping (EAM) in patients with ischemic cardiomyopathy. Methods Single centre retrospective study enrolling consecutive patients with ischemic cardiomyopathy referred for endocardial VT ablation that underwent cardiac CT for procedure planning since 2021. Patients were excluded if EAM had < 1000 data points. ADAS 3D® software was used to analyse CT images, automatically segmenting the left ventricle (LV) into the 17 American Heart Association segments and calculating end-diastolic WT for each one. Four standardized views (anterior-posterior, posterior-anterior, superior, and inferior) of the segmented LV on ADAS 3D® were used to aid in manual segmentation of the EAM. The endocardial voltage maps were created using CARTO3® software (Figure 1). For each patient, EAM was interpreted to create 2 different bulls’ eye maps, according to the presence or absence of bipolar potentials < 0.5 (dense scar) or < 1.5mV (low voltage). Only segments with >20% extension of low bipolar voltage were considered as altered. Results We included a cohort of 8 patients (mean age 67±12 years, 87.5% male, median LVEF of 32% [IQR 25-49]). All but one patient had implanted cardiac device (6 ICD, 1 CRT-D). Cardiac CT was performed 1 day (IQR 0-2) before the ablation. Overall, 136 segments were analysed, 8 of which did not have voltage information. Of the remaining 128, 51 (39.8%) had dense scar and 57 (41.9%) had low voltage. There was a good correlation between mean WT and the presence or absence of both dense scar (area under de curve (AUC) 0.799, p<0.001) and low voltage (AUC 0.838, p<0.001) in each LV segment. Conclusion WT measured by CT appears to have a strong correlation with dense scar and low voltage in EAM in patients with ischemic cardiomyopathy undergoing VT ablation. This technique may be useful to plan interventions in patients in whom CMR is not feasible.

Resource and stability near a critical point from the quantum information perspective

In the presence of chemical potential and temperature, we holographically study subregion complexity in a non-conformal quantum field theory with a critical point. We propose a new interpretation according to which the states, needing (more) less information to be specified, characterize the (un) stable thermodynamical solutions. We observe the increasing and decreasing effects of chemical potential and temperature on holographic subregion complexity, respectively. These two opposite behaviors lead to a point where subregion complexity of the mixed state is the same as this value for a zero temperature conformal field theory. We also present a new description of the difference between the minimum and the maximum value (the value near the critical point) of holographic subregion complexity as a resource for doing computational work to prepare the state near the critical point from the state far from it. We also calculate the critical exponent.

On the Prospect of Fossil Fuel on Planet Mars

Planet Mars has long been a source of attraction to astronomers and scientists. In 1976, the Viking probes inaugurated the beginning of a new era in human history by searching for primitive lifeforms on Mars. Successive Martian missions have discovered evidence, in the form of dried rivers and lake beds, of the prior abundance of water on the Martian surface leading to conjecture that, millions of years ago, some kind of primeval lifeforms, supported by chemical and biological processes, are at the origin of formation of fossil fuel on planet Mars. One hypothesis even maintains that conditions on Mars, in its early history, resembled, to a major extent, the environment reigning on Earth in its embryonic stage. Petroleum has been the outcome of this natural environment on Earth. It is argued that nascent conditions on Mars developed a fertile environment leading to the formation of fossil fuel. The aim of this paper is to investigate the prospect of such hypothesis, and to examine the likelihood that subterranean resources being extant in Mars in view of the latest data gathered by Martian probes. Analysis shows that kerogen is a viable signature of the potential presence of fossil fuel on Mars, and this result comports with preliminary findings of the Martian Rovers.

Phonon modes of magnetic vortex lattices in finite isospin chiral perturbation theory

We study phonon modes associated with magnetic vortex lattices of finite isospin chiral perturbation theory near the upper critical point by introducing quasimomentum fluctuations to the lattice and calculate dispersion relations associated with the optical and acoustic modes. We find that one of the acoustic modes is massless and that its energy for small transverse quasimomentum is quartic (due the presence of an isospin chemical potential), which is significantly softer than the “supersoft” (quadratic) massless mode of the Abelian Higgs Model (AHM). Due to the presence of derivative interactions, which is absent in the AHM, the speed of the longitudinal mode depends on both the isospin chemical potential and the external magnetic field. Our results suggest that the standard assumption of an ordered lattice in finite isospin QCD should be revisited and the existence of a disordered spaghetti phase of a vortex liquid or gas, should be considered.

Midpoint projection algorithm for stochastic differential equationson manifolds.

Stochastic differential equationsprojected onto manifolds occur in physics, chemistry, biology, engineering, nanotechnology, and optimization, with interdisciplinary applications. Intrinsic coordinate stochastic equationson the manifold are sometimes computationally impractical, and numerical projections are therefore useful in many cases. In this paper a combined midpoint projection algorithm is proposed that uses a midpoint projection onto a tangent space, combined with a subsequent normal projection to satisfy the constraints. We also show that the Stratonovich form of stochastic calculus is generally obtained with finite bandwidth noise in the presence of a strong enough external potential that constrains the resulting physical motion to a manifold. Numerical examples are given for a wide range of manifolds, including circular, spheroidal, hyperboloidal, and catenoidal cases, higher-order polynomial constraints that give a quasicubical surface, and a ten-dimensional hypersphere. In all cases the combined midpoint method has greatly reduced errors compared to other methods used for comparison, namely, a combined Euler projection approach and a tangential projection algorithm. We derive intrinsic stochastic equationsfor spheroidal and hyperboloidal surfaces for comparison purposes to verify the results. Our technique can handle multiple constraints, which allows manifolds that embody several conserved quantities. The algorithm is accurate, simple, and efficient. A reduction of an order of magnitude in the diffusion distance error is found compared to the other methods and an up to several orders of magnitude reduction in constraint function errors.

P101 HIGH–DENSITY MAPPING OF KOCH‘S TRIANGLE DURING SINUS RHYTHM AND TYPICAL AV NODAL REENTRANT TACHYCARDIA INTEGRATED WITH THE DIRECT RECORDING OF ATRIOVENTRICULAR NODE STRUCTURES POTENTIAL: A MULTICENTER NON–RANDOMIZED STUDY

Abstract Background Atrioventricular nodal re–entrant tachycardia (AVNRT) is humans‘ most frequent regular tachycardia. Nevertheless, understanding the exact mechanism and pathways involved in the circuit that sustains the arrhythmia is still incomplete. Also, the recording of nodal potential was performed previously in animals with relative success, but not in humans. The aim of our study is to identify the potential of the compact atrioventricular node (AVN) and inferior extensions by using an electroanatomic mapping of the right atrium and the Koch‘s triangle in sinus rhythm and during AVNRT. Methods From March 2021 to July 2022, 79 patients with AVNRT underwent high–resolution mapping and complete ablation in 12 Italian Hospitals. No patients with atrial fibrillation or sustained ventricular tachycardia were included. The diagnosis of AVNRT was established according to standard criteria and diagnostic pacing manoeuvres. The presence and location of SP potentials, i.e., Jackman potential (JP) and Haïssaguerre potential (HP) were evaluated in each patient. The electroanatomic mapping obtained were merged with cardiac computerized tomography (CT) scan. Results Forty–five cases of successful AVNRT ablation were included in the analysis. The AVN potential has been demonstrated to be a very low frequency signal distinct from atrial, His bundle or ventricular activations, that can be recorded from electrodes overlying the region of the compact AVN by using a non–conventional bipolar electrogram filtering both during sinus rhythm and slow fast AVNRT. AVN potential was identified in all cases in the mid–septal region (#5) in both sinus rhythm and tachycardia. The mid–septal region and the postero–septal regions (#7) bounded anteriorly by the tricuspid annulus and posteriorly by the lateral wall toward the crista terminalis showed a higher prevalence of HP than other regions (46.7% in region #5 and 51.1% in region #7, p<0.0001 vs other regions, respectively). JPs seemed to have a converse distribution across the KT and they were mainly observed in the mid–postero–septal region (73.3%). After 359±121 days of follow–up, no patients had a recurrence of AVNRT. Conclusion The exact anatomical site and pathways involved in AVNRT are still unclear as well as the analysis and characterisation of the AVN potential. Our results represent the first evidence of the recording of AVN potential. Further studies and technological improvements are needed to confirm our results.

Topological and Stacked Flat Bands in Bilayer Graphene with a Superlattice Potential.

We show that bilayer graphene in the presence of a 2D superlattice potential provides a highly tunable setup that can realize a variety of flat band phenomena. We focus on two regimes: (i)topological flat bands with nonzero Chern numbers, C, including bands with higher Chern numbers |C|>1 and (ii)an unprecedented phase consisting of a stack of nearly perfect flat bands with C=0. For realistic values of the potential and superlattice periodicity, this stack can span nearly 100meV, encompassing nearly all of the low-energy spectrum. We further show that in the topological regime, the topological flat band has a favorable band geometry for realizing a fractional Chern insulator (FCI) and use exact diagonalization to show that the FCI is in fact the ground state at 1/3 filling. Our results provide a realistic guide for future experiments to realize a new platform for flat band phenomena.

Comparative Analysis of the CO2 Extraction from Biogas Absorption Processes Effectiveness

Currently, the developed EU countries have implemented biomethane production projects from biogas, supply it to natural gas distribution grid with subsequent production of electricity or (and) heat, and use biomethane as motor fuel or supply to the gas network. It is also extremely relevant for Ukraine, supposing the problems with gas import due to Russian aggression and the presence of a large agricultural potential. The concern that arises is the rational choice of the technology for producing biomethane from biogas.The Gas Institute of the National Academy of Sciences of Ukraine has extensive experience in the development of technologies for the biogas collection, its direct usage, and CO2 extraction by the amine absorption method. Some of the technologies have been implemented at landfills in Ukraine. Data on other methods of CO2 extraction are widely available in world publications, so the authors compared the technologies from the point of view of their practical use possibility. Using computer modeling, the energy costs during the production of biomethane from biogas using the most advanced amine and water absorption processes for cleaning biogas from carbon dioxide were analysed. The combined water-amine absorption method of biogas purification from CO2 was included in the comparative analysis in which carbon dioxide was previously removed by water absorption at a pressure up to 0.3 MPa and output finally purified by amine absorption. Calculations for amine technology are verified in a pilot study.For a range of the CO2 concentration in biogas 32– 42 % vol., the specific energy consumption when using water absorption, the extraction of carbon dioxide from biogas is on average two times less compared to amine absorption, but at the same time the loss of CH4 due to its solubility during water absorption amounted to 7.1–7.6 %, with practically no losses of CH4 in amine absorption, and minor losses (0.17–2.8 %) in combined water-amine technology.The energy consumption of combined water-amine absorption is comparable to that of water absorption due to: a) reduction of heat losses for regeneration process of saturated amine absorbent, as part of CO2 has already been removed with water technology; b) using the CH4 excess to compensate power consumption of the biogas compressor during the preliminary water absorption of CO2 and/ or to compensate heat costs of the saturated amine absorbent regeneration.The results of extracting carbon dioxide from biogas processes modeling can be used to optimize technological absorption schemes for the production of biomethane, an analogue of natural gas.

Relativistic ratcheting on the surface of topological insulator Bi2Se3 attached to spiral multiferroic oxide

Relativistic ratcheting of Dirac fermions on the surface of topological insulator Bi2Se3 attached to a spiral multiferroic oxide is investigated. We find that the Dirac fermions on the surface of topological insulator Bi2Se3 exhibit pronounced Brownian motion, tuned by the strength of exchange field established by the interaction of spin degrees of Dirac fermions and multiferroic oxide. The surface Dirac fermions show ratchet effect as a net current under the influence of orthogonal, commensurate ac drives in the presence of a symmetric periodic potential set by the exchange field.

SYK Model with global symmetries in the double scaling limit

We discuss the double scaling limit of the SYK model with global symmetries. We develop the chord diagram techniques to compute the moments of the Hamiltonian and the two point function in the presence of arbitrary chemical potential. We also derive a transfer matrix acting on an auxiliary hilbert space which can capture the chord diagram contributions. We present explicit results for the case of classical group symmetries namely orthogonal, unitary and symplectic groups. We also find the partition functions at fixed charges.

Mapping human pathogens in wastewater using a metatranscriptomic approach

The monitoring of cities’ wastewaters for the detection of potentially pathogenic viruses and bacteria has been considered a priority during the COVID-19 pandemic to monitor public health in urban environments. The methodological approaches frequently used for this purpose include deoxyribonucleic acid (DNA)/Ribonucleic acid (RNA) isolation followed by quantitative polymerase chain reaction (qPCR) and reverse transcription (RT)‒qPCR targeting pathogenic genes. More recently, the application of metatranscriptomic has opened opportunities to develop broad pathogenic monitoring workflows covering the entire pathogenic community within the sample. Nevertheless, the high amount of data generated in the process requires an appropriate analysis to detect the pathogenic community from the entire dataset. Here, an implementation of a bioinformatic workflow was developed to produce a map of the detected pathogenic bacteria and viruses in wastewater samples by analysing metatranscriptomic data. The main objectives of this work was the development of a computational methodology that can accurately detect both human pathogenic virus and bacteria in wastewater samples. This workflow can be easily reproducible with open-source software and uses efficient computational resources. The results showed that the used algorithms can predict potential human pathogens presence in the tested samples and that active forms of both bacteria and virus can be identified. By comparing the computational method implemented in this study to other state-of-the-art workflows, the implementation analysis was faster, while providing higher accuracy and sensitivity. Considering these results, the processes and methods to monitor wastewater for potential human pathogens can become faster and more accurate. The proposed workflow is available at https://github.com/waterpt/watermonitor and can be implemented in currently wastewater monitoring programs to ascertain the presence of potential human pathogenic species.

Hanging Topic Left Dislocations as extrasentential constituents: toward a paratactic account. Evidence from English and Spanish

Abstract The paper argues for a bisentential, paratactic account of Hanging Topic Left Dislocations wherein the syntactically unconnected hanging topic phrase is the remnant of an elliptical copulative sentence which is linearly juxtaposed to the second, host sentence. This proposal represents a natural extension of Ott’s system for Clitic Left Dislocations and predicative non-restrictive nominal appositives. By assuming that the hanging topic is structurally disconnected from the host sentence, the analysis constitutes a radical departure from integrated/monosentential approaches within cartography, which analyze hanging topics as intrasentential, albeit peripheral, constituents in the left spine of the clause. Using data from English and Spanish as well as from other linguistic varieties, the paratactic approach provides a principled account of various issues facing monosentential analyses of hanging topics, including anti-connectivity, coreference with the resumptive/epithetic correlate, comma intonation/pause potential, case, insensitivity to locality constraints, islandhood, and potential presence of interjections between hanging topic and host sentence, amongst others. The account is also successful in capturing orphaned topics, which are not linked to any constituent in the sentence they occur with, alongside ‘interrogative’ and hyperdetached hanging topics.

Periodic orbit theory of Bethe-integrable quantum systems: an N-particle Berry–Tabor trace formula

One of the fundamental results of semiclassical theory is the existence of trace formulae showing how spectra of quantum mechanical systems emerge from massive interference among amplitudes related with time-periodic structures of the corresponding classical limit. If it displays the properties of Hamiltonian integrability, this connection is given by the celebrated Berry–Tabor trace formula, and the periodic structures it is built on are tori supporting closed trajectories in phase space. Here we show how to extend this connection into the domain of quantum many-body systems displaying integrability in the sense of the Bethe ansatz, where a classical limit cannot be rigorously defined due to the presence of singular potentials. Formally following the original derivation of Berry and Tabor (1976 Proc. R. Soc. A 349 101), but applied to the Bethe equations without underlying classical structure, we obtain a many-particle trace formula for the density of states of N interacting bosons on a ring, the Lieb–Liniger model. Our semiclassical expressions are in excellent agreement with quantum mechanical results for and 4 particles. For N = 2 we relate our results to the quantization of billiards with mixed boundary conditions. Our work paves the way towards the treatment of the important class of integrable many-body systems by means of semiclassical trace formulae pioneered by Michael Berry in the single-particle context.

PO-03-142 ABLATION OF EPICARDIAL POSTEROSEPTAL ACCESSORY PATHWAYS IN CHILDREN

Epicardial posteroseptal accessory pathways (Epi-PSAPs) within the coronary sinus (CS) are a rarely reported ablation target in children. They are often associated with abnormal CS anatomy as well as risk of coronary artery (CA) injury. To assess characteristics associated with successful outcome of Epi-PSAP ablation in children. Retrospective cohort study at a tertiary care institution including all patients aged ≤18 years who underwent ablation of Epi-PSAP from 2000-2022. Clinical/electrophysiological characteristics and outcomes were analyzed. Epi-PSAP was targeted in 19 patients. Mean age at procedure was 13.4 (12.1-14.7) years, mean weight was 62.5 (47-78) kg. Prior ablations had been attempted in 7/19 patients. Ventricular preexcitation was present in 12/19 (63%) patients, with steep negative delta wave in lead II in all cases, and 8/12 (67%) demonstrating high risk antegrade conduction. CS angiogram to define the anatomy was performed in all patients. In 5/5 (100%) of cases where CS diverticulum was identified by CS angiogram, it proved to be the ablation target. CA angiogram to define arterial proximity (5mm cutoff) was obtained in 17/19 (90%). CA system was right dominant in 10/17 (59%), and closest arteries were ≥5mm away from the target in 11/17 (65%). Primary energy was RF in 12/19 (63%, artery ≥5mm) and cryo in 7/19 (37%, artery <5mm). Ablation was acutely successful in 18/19 (95%) patients, chronically successful in 15/18 (83%) of patients, over 98.2 (57.8-138.7) months of follow up.There was no apparent difference in outcome between ablation sites in 1) coronary vein; 2) CS diverticulum; or 3) floor of CS (FIG1.A.). The presence of a sharp unipolar accessory pathway potential (FIG1.B.) at the target site was significantly associated with acute (p=0.003) and chronic (p=0.005) success. Choice of energy was not significantly associated with outcome. Performance of CS angiogram (FIG1.C) was significantly associated with acute (p=0.04) and chronic (p=0.03) success when all ablation attempts were analyzed. There was no incidence of major adverse events. Majority of Epi-PSAP in children are manifest with high risk antegrade conduction properties. They can be ablated with RF energy when the coronary arteries are ≥5mm from ablation target, or alternatively with cryoablation. Localizing a sharp unipolar AP potential, identification of CS anatomy by CS angiogram, and delineation of arterial proximity by CA angiogram are associated with successful ablation.