bluuebunny/crossref_metadata_2025 huggingface dataset:
Twist-four gravitational form factor at NNLO QCD from trace anomaly constraints
Authors: Tanaka Kazuhiro
Published: March 2023

Abstract

It is known that the trace anomaly in the QCD energy-momentum tensor Tμν can be attributed to the anomalies for each of the gauge-invariant quark part and gluon part of Tμν, and their explicit three-loop formulas have been derived in the $$ \overline{\textrm{MS}} $$

MS
¯

scheme in the dimensional regularization. The matrix elements of this quark/gluon decomposition of the QCD trace anomaly allow us to derive the QCD constraints on the hadron’s gravitational form factors, in particular, on the twist-four gravitational form factor, $$ {\overline{C}}_{q,g} $$

C
¯

q
,
g

. Using the three-loop quark/gluon trace anomaly formulas, we calculate the forward (zero momentum transfer) value of the twist-four gravitational form factor $$ {\overline{C}}_{q,g} $$

C
¯

q
,
g

at the next-to-next-to-leading-order (NNLO) accuracy. We present quantitative results for nucleon as well as for pion, leading to a model-independent determination of the forward value of $$ {\overline{C}}_{q,g} $$

C
¯

q
,
g

. We find quite different pattern in the obtained results between the nucleon and the pion. In particular, for the nucleon, the present information from experiment and lattice QCD on the nonperturbative matrix elements arising in our NNLO formula allows us to obtain a prediction of the forward value of $$ {\overline{C}}_{q,g} $$

C
¯

q
,
g

at the accuracy of a few percent level.
Gravitational transition form factors of N → ∆ via QCD light-cone sum rules
Authors: Özdem U. , Azizi K.
Published: March 2023

Abstract

We present the first direct calculation on the gravitational form factors (GFFs) of the N → ∆ transition using an analytic method, the QCD light-cone sum rules. The matrix element of the quark part of the energy momentum tensor current sandwiched between the nucleon and ∆ states are parameterized in terms of five independent conserved and four independent non-conserved GFFs, for calculation of which we use the distribution amplitudes (DAs) of the on-shell nucleon expanded in terms of functions with different twists. We present the results for two sets of light-cone input parameters. The results indicate that the behavior of the form factors with respect to Q2 are described by multipole fit functions. Our results may be checked by other phenomenological models including the Lattice QCD as well as future related experiments.
Quasi-topological gravities on general spherically symmetric metric
Authors: Chen Feiyu
Published: March 2023

Abstract

In this work we study a more restricted class of quasi-topological gravity theories where the higher curvature terms have no contribution to the equation of motion on general static spherically symmetric metric where gttgrr ≠ constant. We construct such theories up to quintic order in Riemann tensor and observe an important property of these theories: the higher order term in the Lagrangian vanishes identically when evaluated on the most general non-stationary spherically symmetric metric ansatz. This not only signals the higher terms could only have non-trivial effects when considering perturbations, but also makes the theories quasi-topological on a much wider range of metrics. As an example of the holographic effects of such theories, we consider a general Einstein-scalar theory and calculate it’s holographic shear viscosity.
Infinite distances in multicritical CFTs and higher-spin holography
Authors: Basile Ivano , Campoleoni Andrea , Pekar Simon , Skvortsov Evgeny
Published: March 2023

Abstract

We investigate the swampland distance conjecture in higher-spin gravity. To this end, we study multicritical generalizations of large-N vector models, bosonic and fermionic, and we compute the quantum information distance along selected renormalization-group trajectories toward the higher-spin limit. In contrast to the expected exponential decay of higher-spin masses or anomalous dimensions, we find that infinite-distance limits in these models lead to a power-like decay. This suggests that stringy exponential decays are characteristic of matrix-like gauge theories, rather than vector models. We corroborate this notion studying the information distance along coupling variations in Chern-Simons-matter CFTs, where matrix-like degrees of freedom dominate over vector-like ones.
Machine learning-based jet and event classification at the Electron-Ion Collider with applications to hadron structure and spin physics
Authors: Lee Kyle , Mulligan James , Płoskoń Mateusz , Ringer Felix , Yuan Feng
Published: March 2023

Abstract

We explore machine learning-based jet and event identification at the future Electron-Ion Collider (EIC). We study the effectiveness of machine learning-based classifiers at relatively low EIC energies, focusing on (i) identifying the flavor of the jet and (ii) identifying the underlying hard process of the event. We propose applications of our machine learning-based jet identification in the key research areas at the future EIC and current Relativistic Heavy Ion Collider program, including enhancing constraints on (transverse momentum dependent) parton distribution functions, improving experimental access to transverse spin asymmetries, studying photon structure, and quantifying the modification of hadrons and jets in the cold nuclear matter environment in electron-nucleus collisions. We establish first benchmarks and contrast the estimated performance of flavor tagging at the EIC with that at the Large Hadron Collider. We perform studies relevant to aspects of detector design including particle identification, charge information, and minimum transverse momentum capabilities. Additionally, we study the impact of using full event information instead of using only information associated with the identified jet. These methods can be deployed either on suitably accurate Monte Carlo event generators, or, for several applications, directly on experimental data. We provide an outlook for ultimately connecting these machine learning-based methods with first principles calculations in quantum chromodynamics.
Entanglement dynamics of the non-unitary holographic channel
Authors: Goto Kanato , Nozaki Masahiro , Tamaoka Kotaro , Tan Mao Tian
Published: March 2023

Abstract

We study the dynamical properties of a strongly scrambling quantum circuit involving a projective measurement on a finite-sized region by studying the operator entanglement entropy and mutual information (OEE and BOMI) of the dual operator state that corresponds to this quantum circuit. The time-dependence of the OEE exhibits a new dynamical behavior of operator entanglement, namely an additional fractional coefficient that accompanies the linear time growth of the OEE. For a holographic system, this is equivalent to an additional fractional coefficient that modifies the linear growth rate of the wormhole volume. The time-dependence of the BOMI shows that the projective measurement may destroy the non-local correlations in this dual state. We also propose a gravity dual as well as a line-tension picture, which is an effective model, that describe this strongly scrambling quantum circuit.
Constraints on ultralight scalar dark matter with quadratic couplings
Authors: Bouley Thomas , Sørensen Philip , Yu Tien-Tien
Published: March 2023

Abstract

Ultralight dark matter is a compelling dark matter candidate. In this work, we examine the impact of quadratically-coupled ultralight dark matter on the predictions of Big Bang Nucleosynthesis. The presence of ultralight dark matter can modify the effective values of fundamental constants during Big Bang Nucleosynthesis, modifying the predicted abundances of the primordial elements such as Helium-4. We improve upon the existing literature in two ways: firstly, we take into account the thermal mass acquired by the ultralight dark matter due to its quadratic interactions with the Standard Model bath, which affects the cosmological evolution of the dark matter. Secondly, we treat the weak freeze-out using the full kinetic equations instead of using an instantaneous approximation. Both improvements were shown to impact the Helium-4 prediction in the context of universally-coupled dark matter in previous work. We extend these lessons to more general couplings. We show that with these modifications, Big Bang Nucleosynthesis provides strong constraints of ultralight dark matter with quadratic couplings to the Standard Model for a large range of masses as compared to other probes of this model, such as equivalence principle tests, atomic and nuclear clocks, as well as astrophysical and other cosmological probes.
Absence of operator growth for average equal-time observables in charge-conserved sectors of the Sachdev-Ye-Kitaev model
Authors: Paviglianiti Alessio , Bandyopadhyay Soumik , Uhrich Philipp , Hauke Philipp
Published: March 2023

Abstract

Quantum scrambling plays an important role in understanding thermalization in closed quantum systems. By this effect, quantum information spreads throughout the system and becomes hidden in the form of non-local correlations. Alternatively, it can be described in terms of the increase in complexity and spatial support of operators in the Heisenberg picture, a phenomenon known as operator growth. In this work, we study the disordered fully-connected Sachdev-Ye-Kitaev (SYK) model, and we demonstrate that scrambling is absent for disorder-averaged expectation values of observables. In detail, we adopt a formalism typical of open quantum systems to show that, on average and within charge-conserved sectors, operators evolve in a relatively simple way which is governed by their operator size. This feature only affects single-time correlation functions, and in particular it does not hold for out-of-time-order correlators, which are well-known to show scrambling behavior. Making use of these findings, we develop a cumulant expansion approach to approximate the evolution of equal-time observables. We employ this scheme to obtain analytic results that apply to arbitrary system size, and we benchmark its effectiveness by exact numerics. Our findings shed light on the structure of the dynamics of observables in the SYK model, and provide an approximate numerical description that overcomes the limitation to small systems of standard methods.
NNLO QCD corrections to event shapes at the LHC
Authors: Alvarez Manuel , Cantero Josu , Czakon Michal , Llorente Javier , Mitov Alexander , Poncelet Rene
Published: March 2023

Abstract

In this work we perform the first ever calculation of jet event shapes at hadron colliders at next-to-next-to leading order (NNLO) in QCD. The inclusion of higher order corrections removes the shape difference observed between data and next-to-leading order predictions. The theory uncertainty at NNLO is comparable to, or slightly larger than, existing measurements. Except for narrow kinematical ranges where all-order resummation becomes important, the NNLO predictions for the event shapes considered in the present work are reliable. As a prime application of the results derived in this work we provide a detailed investigation of the prospects for the precision determination of the strong coupling constant and its running through TeV scales from LHC data.
Search for exotic decays of the Higgs boson into long-lived particles with jet pairs in the final state at CLIC
Authors: Kucharczyk Marcin , Goncerz Mateusz
Published: March 2023

Abstract

A study of the sensitivity of the CLIC_ILD detector model for massive long-lived particles produced in the decay of the Higgs boson is presented, using a data sample of e+e− collisions at $$ \sqrt{\textrm{s}} $$

s

= 350 GeV and $$ \sqrt{\textrm{s}} $$

s

= 3 TeV, corresponding to an integrated luminosity of 1 ab−1 and 3 ab−1, respectively. The sensitivity range covers long-lived particle lifetimes from 1 to 300 ps, masses between 25 and 50 GeV/c2, and a parent Higgs mass of 126 GeV/c2. Sensitivities to the production cross-section as a function of the long-lived-particle mass and lifetime are determined.
Universal spinning Casimir equations and their solutions
Authors: Burić Ilija , Schomerus Volker
Published: March 2023

Abstract

Conformal blocks are a central analytic tool for higher dimensional conformal field theory. We employ Harish-Chandra’s radial component map to construct universal Casimir differential equations for spinning conformal blocks in any dimension d of Euclidean space. Furthermore, we also build a set of differential “shifting” operators that allow to construct solutions of the Casimir equations from certain seeds. In the context of spinning four-point blocks of bulk conformal field theory, our formulas provide an elegant and far reaching generalisation of existing expressions to arbitrary tensor fields and arbitrary dimension d. The power of our new universal approach to spinning blocks is further illustrated through applications to defect conformal field theory. In the case of defects of co-dimension q = 2 we are able to construct conformal blocks for two-point functions of symmetric traceless bulk tensor fields in both the defect and the bulk channel. This opens an interesting avenue for applications to the defect bootstrap. Finally, we also derive the Casimir equations for bulk-bulk-defect three-point functions in the bulk channel.
Hadamard Products of Symbolic Powers and Hadamard Fat Grids
Authors: Bahmani Jafarloo I. , Bocci C. , Guardo E. , Malara G.
Published: March 2023

In this paper we address the question if, for points $$P, Q \in \mathbb {P}^{2}$$

P
,
Q
∈

P

2

, $$I(P)^{m} \star I(Q)^{n}=I(P \star Q)^{m+n-1}$$

I

(
P
)

m

⋆
I

(
Q
)

n

=
I

(
P
⋆
Q
)

m
+
n
-
1

and we obtain different results according to the number of zero coordinates in P and Q. Successively, we use our results to define the so called Hadamard fat grids, which are the result of the Hadamard product of two sets of collinear points with given multiplicities. The most important invariants of Hadamard fat grids, as minimal resolution, Waldschmidt constant and resurgence, are then computed.
Endogenous but not sensory-driven activity controls migration, morphogenesis and survival of adult-born juxtaglomerular neurons in the mouse olfactory bulb
Authors: Li Kaizhen , Figarella Katherine , Su Xin , Kovalchuk Yury , Gorzolka Jessika , Neher Jonas J. , Mojtahedi Nima , Casadei Nicolas , Hedrich Ulrike B. S. , Garaschuk Olga
Published: March 2023

The development and survival of adult-born neurons are believed to be driven by sensory signaling. Here, in vivo analyses of motility, morphology and Ca2+ signaling, as well as transcriptome analyses of adult-born juxtaglomerular cells with reduced endogenous excitability (via cell-specific overexpression of either Kv1.2 or Kir2.1 K+ channels), revealed a pronounced impairment of migration, morphogenesis, survival, and functional integration of these cells into the mouse olfactory bulb, accompanied by a reduction in cytosolic Ca2+ fluctuations, phosphorylation of CREB and pCREB-mediated gene expression. Moreover, K+ channel overexpression strongly downregulated genes involved in neuronal migration, differentiation, and morphogenesis and upregulated apoptosis-related genes, thus locking adult-born cells in an immature and vulnerable state. Surprisingly, cells deprived of sensory-driven activity developed normally. Together, the data reveal signaling pathways connecting the endogenous intermittent neuronal activity/Ca2+ fluctuations as well as enhanced Kv1.2/Kir2.1 K+ channel function to migration, maturation, and survival of adult-born neurons.
Influence of a prolonged shelf time on PA12 laser sintering powder and resulting part properties
Authors: Klippstein Sven Helge , Kletetzka Ivo , Sural Ilknur , Schmid Hans-Joachim
Published: March 2023

In the laser sintering technology, the semi-crystalline polymer material is exposed to elevated temperatures during processing, which leads to serious material ageing for most materials. This has already been investigated intensively by various authors. However, the ageing of the material at ambient temperatures during shelf life has not been the focus so far. The need to analyse the shelf life can be derived from an ecological and economic point of view. This work is focusing on the shelf life of PA2200 (PA12). To reduce the potential influences of powder production fluctuations, two different powder batches stored for 5.5 years and 6.5 years are investigated and compared to a reference powder produced 0.5 years before these investigations. Multiple powder analyses and part characterisations have been performed. A significant yellowing and molecular chain length reduction can be derived from the measurement results. Whereas the influence on mechanical part performance was minor, the parts built with the stored powders are more yellowish. As it is most likely that this is due to the consumption of polyamide stabilisers, it can be assumed that these parts will be subject to significantly faster ageing. Therefore, it is still not recommended to use the stored powders for critical parts or light intense and humid environments.
Hot working behaviour of low-cost Ti-3.4Fe bio-implant alloy
Authors: Mosoma Dineo , Klenam Desmond , Maunganidze Takunda , Bodunrin Michael
Published: March 2023

This study investigated the hot workability of an experimental, non-toxic, low-cost Ti-3.4Fe alloy using flow stress analysis, constitutive modelling, processing maps and microstructural examination. Hot compression tests were performed on Ti-3.4Fe alloy samples at different deformation temperatures (750, 800, 850 and 900 °C), strain rates (0.05, 0.1, 1 and 10 s−1) and a total strain of 0.6. The compression tests were performed using a Gleeble® 3500 thermomechanical simulator. The isothermally compressed samples were analysed using a scanning electron microscope to assess the microstructure. An Arrhenius-based model was used to derive the constitutive constants. From the results, the stress exponent and activation energy were 4.91 and 611 kJ.mol−1 under the steady-state stress condition and 5.32 and 675 kJ.mol−1 at peak stress. The stress exponents suggested a dislocation climb and glide mechanism controlling deformation. The processing map showed that the optimum conditions to deform Ti-3.4Fe were 850 °C at a strain rate of 0.1 s−1 for both steady-state and peak stresses. The microstructure revealed kinked, rotated and bent lamella at the safe region (850 °C at 0.05 s−1), confirming the dominance of dynamic recovery as the softening mechanism. Instabilities manifested as cracks and inhomogeneity at 750 °C and 1 s−1 and at 850 °C and 10 s−1.
Investigating nanocatalyst-embedding laser-induced carbon nanofibers for non-enzymatic electrochemical sensing of hydrogen peroxide
Authors: Bruckschlegel Christoph , Schlosser Marc , Wongkaew Nongnoot
Published: March 2023

In this present study, we explored the catalytic behaviors of the in situ generated metal nanoparticles, i.e., Pt/Ni, embedded in laser-induced carbon nanofibers (LCNFs) and their potential for H2O2 detection under physiological conditions. Furthermore, we demonstrate current limitations of laser-generated nanocatalyst embedded within LCNFs as electrochemical detectors and possible strategies to overcome the issues. Cyclic voltammetry revealed the distinctive electrocatalytic behaviors of carbon nanofibers embedding Pt and Ni in various ratios. With chronoamperometry at  +0.5 V, it was found that modulation of Pt and Ni content affected only current related to H2O2 but not other interfering electroactive substances, i.e., ascorbic acid (AA), uric acid (UA), dopamine (DA), and glucose. This implies that the interferences react to the carbon nanofibers regardless of the presence of metal nanocatalysts. Carbon nanofibers loaded only with Pt and without Ni performed best in H2O2 detection in phosphate-buffered solution with a limit of detection (LOD) of 1.4 µM, a limit of quantification (LOQ) of 5.7 µM, a linear range from 5 to 500 µM, and a sensitivity of 15 µA mM−1 cm−2. By increasing Pt loading, the interfering signals from UA and DA could be minimized. Furthermore, we found that modification of electrodes with nylon improves the recovery of H2O2 spiked in diluted and undiluted human serum. The study is paving the way for the efficient utilization of laser-generated nanocatalyst-embedding carbon nanomaterials for non-enzymatic sensors, which ultimately will lead to inexpensive point-of-need devices with favorable analytical performance.

Graphical abstract
Dirac Operators for Matrix Algebras Converging to Coadjoint Orbits
Authors: Rieffel Marc A.
Published: March 2023

In the high-energy physics literature one finds statements such as “matrix algebras converge to the sphere”. Earlier I provided a general precise setting for understanding such statements, in which the matrix algebras are viewed as quantum metric spaces, and convergence is with respect to a quantum Gromov–Hausdorff-type distance. But physicists want even more to treat structures on spheres (and other spaces), such as vector bundles, Yang–Mills functionals, Dirac operators, etc., and they want to approximate these by corresponding structures on matrix algebras. In the present paper we provide a somewhat unified construction of Dirac operators on coadjoint orbits and on the matrix algebras that converge to them. This enables us to prove our main theorem, whose content is that, for the quantum metric-space structures determined by the Dirac operators that we construct, the matrix algebras do indeed converge to the coadjoint orbits, for a quite strong version of quantum Gromov–Hausdorff distance.
The influence of abiotic and biotic conditions on lifecycle stages is critical for estuarine seagrass resilience
Authors: Webster Chanelle , Lavery Paul S. , O’Dea Caitlyn , Sánchez Alarcón Marta , Salgado Kent Chandra , McMahon Kathryn
Published: March 2023

Abiotic and biotic factors influence seagrass resilience, but the strength and relative importance of the effects are rarely assessed over the complete lifecycle. This study examined the effects of abiotic (salinity, temperature, water depth) and biotic (grazing by black swans) factors on Ruppia spp. over the complete lifecycle. Structures were set up in two estuaries ( – 33.637020, 115.412608) that prevented and allowed natural swan grazing of the seagrasses in May 2019, before the start of the growing season. The density of life stage(s) was measured from June 2019 when germination commenced through to January 2020 when most of the seagrass senesced. Our results showed that swans impacted some but not all life stages. Seedling densities were significantly higher in the plots that allowed natural grazing compared to the exclusion plots (e.g. 697 versus 311 seedlings per m-2), revealing an apparent benefit of swans. Swans removed ≤ 10% of seagrass vegetation but a dormant seedbank was present and new propagules were also observed. We conclude that grazing by swans provides some benefit to seagrass resilience by enhancing seedling recruitment. We further investigated the drivers of the different lifecycle stages using general additive mixed models. Higher and more variable salinity led to increased seed germination whilst temperature explained variation in seedling density and adult plant abundance. Bet-hedging strategies of R. polycarpa were revealed by our lifecycle assessment including the presence of a dormant seedbank, germinated seeds and seedlings over the 8-month study period over variable conditions (salinity 2–42 ppt; temperatures 11–28 °C). These strategies may be key determinants of resilience to emerging salinity and temperature regimes from a changing climate.
Post-closure Cost Efficiency in Public Versus Private Landfills: The Case of Emilia-Romagna (Italy)
Authors: Tallaki Mouhcine , Bracci Enrico , Ievoli Riccardo
Published: March 2023

Waste management systems have developed in recent years toward the adoption of sustainable management principles and practices, such as circular economy, zero waste, resource efficiency, waste avoidance, re-use, and recycling. Nevertheless, landfills continue to be used for waste disposal despite their risks related to contamination and effects on urban development. Most research on landfills focuses on their operational and technical aspects, while the performance and cost efficiency in managing landfills is less commonly studied, especially their post-closure management. However, improving efficiency is very relevant in the context of scarce public sector resources. This paper, therefore, analyzes the efficiency of post-closure management of landfills. Drawing on agency and stewardship theories, we focus on the difference in efficiency between public and private management of post-closure landfills. We use a linear mixed regression model to analyze data from 2015 to 2018 relating to 54 landfills (79% of which are privately managed) in the Emilia-Romagna region of Italy. The results show that public management is more efficient than private management. Results contribute to defining drivers of cost and confirming a disparity in the performance of private and public management. Our results cast doubt on the assumption, which is prevalent in new public management theory, that private operators are more efficient than public ones. We conclude by highlighting that to reach efficiency, it is better to increase the effectiveness of regulation in terms of value for money, without pre-determined preferences for the type of management.
Practical aspects of designing background-oriented schlieren (BOS) experiments for vortex measurements
Authors: Schwarz Clemens , Braukmann Johannes N.
Published: March 2023

Setup-related aspects of background-oriented schlieren (BOS) experiments are discussed focusing on a sensitivity parameterS, which represents the relation between light deflection and resulting BOS signal, and the geometric blur. An analytic expression for the geometric blur by means of the circle of confusion (CoC) was derived which shows a proportional relation to the sensitivity factorS. The theoretical findings were validated in a reference experiment using generic distortions in glass plates. It was found that the filtering effect of the blur decreases the maximum background shift and its influence can be expressed with a blur loss factorB, which depends on the size of the CoC in relation to the investigated object. Multiplying the setup sensitivitySwith the blur lossBresults in the effective sensitivity$$S _{{\rm eff}}$$Seffthat determines the maximum achievable BOS signal of a schlieren object. For the investigated reference objects, the maximum effective sensitivity$$S _{{\rm eff}}$$Seffwas found to occur at CoC sizes in the object domain from 2.5 to 3.8 times the extent of the investigated objects. A step-by-step method is proposed for designing BOS experiments to obtain a maximum signal strength. The design parameters are further discussed specifically in regard to rotor tip vortex visualization, for which a variety of previously reported experiments are compared. A simple prediction method for the BOS signal of blade tip vortices is proposed and validated with experimental data from a rotor test stand. The application of the method to rotor systems of different size shows the requirement for increasingly higher sensitivity values for visualizing vortices of small-scale rotors.

Graphical abstract
Vortex ring state of a shrouded rotor: an experimental survey
Authors: Pickles David J. , Zagaglia Daniele , Busse Angela , Green Richard B.
Published: March 2023

The vortex ring state (VRS) is a flow condition typical of rotors operating in axial descent flight which may lead to large unpredictable thrust oscillations and possibly the loss of control of the rotorcraft. Despite the dangers associated with this flight condition, there is a distinct lack of detailed experimental data related to shrouded rotors operating in axial descent, which is of relevance owing to the number of novel unmanned aerial vehicles that incorporate this technology. This manuscript presents an experimental investigation designed to assess if and how the presence of the shroud affects the development of the vortex ring state. To this end, laser Doppler anemometry and particle image velocimetry were used to investigate the flow for a range of descent velocities and results were compared with those obtained without the shroud. Time-averaged data were used to assess the general structures of the flow fields, whilst statistical analysis of the velocity fluctuations and modal analysis of the velocity field using proper orthogonal decomposition highlighted the unsteady features of the flow. The investigation showed that shrouded rotors enter the VRS similarly to their isolated counterparts, and the presence of the shroud may be responsible for a slight delay of its onset.

Graphical abstract
Glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA): a molecularly distinct brain tumor type with recurrent NTRK gene fusions
Authors: Bogumil Henri , Sill Martin , Schrimpf Daniel , Ismer Britta , Blume Christina , Rahmanzade Ramin , Hinz Felix , Cherkezov Asan , Banan Rouzbeh , Friedel Dennis , Reuss David E. , Selt Florian , Ecker Jonas , Milde Till , Pajtler Kristian W. , Schittenhelm Jens , Hench Jürgen , Frank Stephan , Boldt Henning B. , Kristensen Bjarne Winther , Scheie David , Melchior Linea C. , Olesen Viola , Sehested Astrid , Boué Daniel R. , Abdullaev Zied , Satgunaseelan Laveniya , Kurth Ina , Seidlitz Annekatrin , White Christine L. , Ng Ho-Keung , Shi Zhi-Feng , Haberler Christine , Deckert Martina , Timmer Marco , Goldbrunner Roland , Tauziède-Espariat Arnault , Varlet Pascale , Brandner Sebastian , Alexandrescu Sanda , Snuderl Matija , Aldape Kenneth , Korshunov Andrey , Witt Olaf , Herold-Mende Christel , Unterberg Andreas , Wick Wolfgang , Pfister Stefan M. , von Deimling Andreas , Jones David T. W. , Sahm Felix , Sievers Philipp
Published: March 2023

Glioneuronal tumors are a heterogenous group of CNS neoplasms that can be challenging to accurately diagnose. Molecular methods are highly useful in classifying these tumors—distinguishing precise classes from their histological mimics and identifying previously unrecognized types of tumors. Using an unsupervised visualization approach of DNA methylation data, we identified a novel group of tumors (n = 20) that formed a cluster separate from all established CNS tumor types. Molecular analyses revealed ATRX alterations (in 16/16 cases by DNA sequencing and/or immunohistochemistry) as well as potentially targetable gene fusions involving receptor tyrosine-kinases (RTK; mostly NTRK1-3) in all of these tumors (16/16; 100%). In addition, copy number profiling showed homozygous deletions of CDKN2A/B in 55% of cases. Histological and immunohistochemical investigations revealed glioneuronal tumors with isomorphic, round and often condensed nuclei, perinuclear clearing, high mitotic activity and microvascular proliferation. Tumors were mainly located supratentorially (84%) and occurred in patients with a median age of 19 years. Survival data were limited (n = 18) but point towards a more aggressive biology as compared to other glioneuronal tumors (median progression-free survival 12.5 months). Given their molecular characteristics in addition to anaplastic features, we suggest the term glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA) to describe these tumors. In summary, our findings highlight a novel type of glioneuronal tumor driven by different RTK fusions accompanied by recurrent alterations in ATRX and homozygous deletions of CDKN2A/B. Targeted approaches such as NTRK inhibition might represent a therapeutic option for patients suffering from these tumors.
A prospective study of cellular immune response to booster COVID-19 vaccination in multiple sclerosis patients treated with a broad spectrum of disease-modifying therapies
Authors: Torres Pascual , Sancho-Saldaña Agustín , Gil Sánchez Anna , Peralta Silvia , Solana Maria José , Bakkioui Sofian , González-Mingot Cristina , Quibus Laura , Ruiz-Fernández Emilio , San Pedro-Murillo Eduardo , Brieva Luis
Published: March 2023

Background

Most people with Multiple Sclerosis (pwMS) are subjected to immunomodulatory disease-modifying treatments (DMTs). As a result, immune responses to COVID-19 vaccinations could be compromised. There are few data on cellular immune responses to the use of COVID-19 vaccine boosters in pwMS under a broad spectrum of DMTs.

Methods

In this prospective study, we analysed cellular immune responses to SARS-CoV-2 mRNA booster vaccinations in 159 pwMS with DMT, including: ocrelizumab, rituximab, fingolimod, alemtuzumab, dimethyl fumarate, glatiramer acetate, teriflunomide, natalizumab and cladribine.

Results

DMTs, and particularly fingolimod, interact with cellular responses to COVID-19 vaccination. One booster dose does not increase cellular immunity any more than two doses, except in the cases of natalizumab and cladribine. SARS-CoV-2 infection combined with two doses of vaccine resulted in a greater cellular immune response, but this was not observed after supplementary booster jabs. Ocrelizumab-treated pwMS who had previously received fingolimod did not develop cellular immunity, even after receiving a booster. The time after MS diagnosis and disability status negatively correlated with cellular immunity in ocrelizumab-treated pwMS in a booster dose cohort.

Conclusions

After two doses of SARS-CoV-2 vaccination, a high response yield was achieved, except in patients who had received fingolimod. The effects of fingolimod on cellular immunity persisted for more than 2 years after a change to ocrelizumab (which, in contrast, conserved cellular immunity). Our results confirmed the need to find alternative protective measures for fingolimod-treated people and to consider the possible failure to provide protection against SARS-CoV-2 when switching from fingolimod to ocrelizumab.
Predictors of return to work for people on sick leave with depression, anxiety and stress: secondary analysis from a randomized controlled trial
Authors: Bjørkedal Siv-Therese , Fisker Jonas , Hellström Lone Christina , Hoff Andreas , Poulsen Rie Mandrup , Hjorthøj Carsten , Bojesen Anders Bo , Rosenberg Nicole Gremaud , Eplov Lene Falgaard
Published: March 2023

Purpose

Knowledge about predictors of return to work (RTW) in people on sick leave with common mental disorders (CMDs) may inform the development of effective vocational rehabilitation interventions for this target group. In this study, we investigated predictors of RTW at 6 and 12 months in people on sick leave with depression, anxiety disorders or stress-related disorders.

Methods

We have performed a secondary analysis, utilizing data from two RCTs that evaluated the efficacy of an integrated health care and vocational rehabilitation intervention. Data were obtained from mental health assessments, questionnaires and registers. Using Cox regression analysis, the relationship between baseline variables and RTW was analysed at 6 and 12 months after randomization within the group of CMD as a whole and within the subgroups of depression, anxiety and stress-related disorders.

Results

Symptom burden and employment status at baseline predicted RTW in the CMD group (n = 1245) and in the three diagnostic subgroups at both time points. RTW self-efficacy predicted RTW in the depression group but not in the anxiety or stress subgroups.

Conclusion

Many predictors of RTW were similar over time and, to some extent, across the CMD subgroups. Findings highlight the need not only to take health-related and psychological factors into account when developing vocational rehabilitation interventions but also to consider workplace strategies and options for support.
The complete dorsal structure is formed from only the blastocoel roof of Xenopus blastula: insight into the gastrulation movement evolutionarily conserved among chordates
Authors: Sato Yuki , Narasaki Izumi , Kunimoto Takuya , Moriyama Yuki , Hashimoto Chikara
Published: March 2023

Gastrulation is a critical event whose molecular mechanisms are thought to be conserved among vertebrates. However, the morphological movement during gastrulation appears to be divergent across species, making it difficult to discuss the evolution of the process. Previously, we proposed a novel amphibian gastrulation model, the “subduction and zippering (S&Z) model”. In this model, the organizer and the prospective neuroectoderm are originally localized in the blastula’s blastocoel roof, and these embryonic regions move downward to make physical contact of their inner surfaces with each other at the dorsal marginal zone. The developmental stage when contact between the head organizer and the anterior-most neuroectoderm is established is called “anterior contact establishment (ACE).” After ACE, the A-P body axis elongates posteriorly. According to this model, the body axis is derived from limited regions of the dorsal marginal zone at ACE. To investigate this possibility, we conducted stepwise tissue deletions using Xenopus laevis embryos and revealed that the dorsal one-third of the marginal zone had the ability to form the complete dorsal structure by itself. Furthermore, a blastocoel roof explant of the blastula, which should contain the organizer and the prospective neuroectoderm in the S&Z model, autonomously underwent gastrulation and formed the complete dorsal structure. Collectively, these results are consistent with the S&Z gastrulation model and identify the embryonic region sufficient for construction of the complete dorsal structure. Finally, by comparing amphibian gastrulation to gastrulation of protochordates and amniotes, we discuss the gastrulation movement evolutionarily conserved among chordates.
Molecular characterization of haemosporidian and haemogregarine diversity in southwestern Iberian amphibians and reptiles
Authors: Parejo-Pulido Daniel , Mora-Rubio Carlos , Marzal Alfonso , Magallanes Sergio
Published: March 2023

The knowledge of the diversity and geographic distribution of parasite species is the first step towards understanding processes of global epidemiology and species conservation. Despite recent increases in research on haemosporidian and haemogregarine parasites of reptiles and amphibians, we still know little about their diversity and parasite-host interactions, especially in the Iberian Peninsula, where a few studies have been conducted. In this study, the haemosporidian and haemogregarine diversity and phylogenetic relationships of the parasites in southwestern Iberian amphibians and reptiles were assessed using PCR approaches on blood samples of 145 individuals from five amphibian and 13 reptile species. The amphibians did not present any of both groups of parasites studied. Regarding reptiles, five Hepatozoon, one Haemogregarina, and one Haemocystidum haplotypes were found infecting four different species, revealing new host records for these parasites. Among them, we found one new Haemocystidium haplotype and three new and a previously reported Hepatozoon haplotype from a north African snake. The latter finding suggests that some Hepatozoon parasites may not be host-specific and have large geographic ranges even crossing geographical barriers. These results increased the knowledge about the geographic distribution and the number of known host species of some reptile apicomplexan parasites, highlighting the great unexplored diversity of them in this region.
K[(CuII,MnII,MnIII)2(TeO3)3]∙2H2O, the first zemannite-type structure based on a Jahn-Teller-distorted framework
Authors: Eder Felix , Miletich Ronald , Weil Matthias
Published: March 2023

Synthetic single crystals of K[(CuII,MnII,MnIII)2(TeO3)3]·2H2O were obtained from an overconcentrated alkaline aqueous solution in the system K2O-MnO-CuO-TeO2 under hydrothermal conditions at T ≤ 220 °C. Subeuhedral single crystals have been investigated by means of single-crystal X-ray diffraction. The crystal structure of this new zemannite-type representative adopts a monoclinic twofold superstructure. The doubling of the unit-cell volume is accompanied by a hexagonal-to-monoclinic symmetry reduction, resulting in threefold twinning with individual crystal domains following the space group symmetry P21. Refinements of site-occupation factors and the evaluation of bond valences suggest a distribution of di- and trivalent cations at the octahedrally coordinated M sites with a ratio (CuII + MnII):MnIII approximating 1:1. Based on arguments about the cation sizes and the individual bond valence sums, a distribution of CuII1–xMnIIIx and MnIIx MnIII1–x at each two of the four M sites can be assumed with x between ~ 0.14 and ~ 0.50. The K+ cations and H2O molecules inside the channels are located off the central channel axis. In contrast to most other known zemannite-type phases, the extra-framework atoms show full occupancies and are not disordered. The distribution of the channel contents supports the anisotropic deformation of the surrounding framework, which follows the local symmetry reduction as required for the Jahn-Teller distortion of the octahedrally coordinated M sites within the framework. The arrangement of the deformed channels can be understood as the origin of the existing superstructure.
Emotional dysregulation predicts problematic gaming in children and youths: a cross-sectional and longitudinal approach
Authors: Schettler Leonie Marie , Thomasius Rainer , Paschke Kerstin
Published: March 2023

Adolescents show a high vulnerability for addictive gaming patterns on the one hand and immature emotion regulation (ER) abilities as a risk factor for mental disorders on the other hand. We investigated the predictive value of ER difficulties on problematic gaming (PG) considering age groups (children vs. youths) and gender cross-sectionally and prospectively in a representative sample of German adolescents via online survey with two measurement points 14 months apart. General Poisson, logistic, and multinomial regression models were estimated to predict gaming patterns by ER difficulties controlling for age group and gender. Results revealed ER difficulties to be significantly associated with PG. Moreover, subgroup analyses indicated differing ER patterns for children vs. youths and boys vs. girls: for children, higher PG values were associated with emotional awareness and emotional clarity whereas for youths it was the acceptance of emotional responses. Moreover, gender differences implicated that boys with PG had more deficits in goal-oriented behavior as well as emotional awareness while affected girls were lacking emotional clarity and had problems with the acceptance of their emotional responses. Interestingly, procrastination was a significant predictor for PG irrespective of subgroups. Furthermore, longitudinal analyses indicated that difficulties in ER promoted PG while stronger procrastination tendencies maintained it. With the inclusion of procrastination, which can be understood as a maladaptive ER strategy, a broader picture of ER difficulties as a risk factor for PG could be drawn. The findings support a better understanding of PG etiology and the development of targeted prevention and intervention measures.
Naïve chicks do not prefer objects with stable body orientation, though they may prefer behavioural variability
Authors: Rosa-Salva Orsola , Hernik Mikołaj , Fabbroni Martina , Lorenzi Elena , Vallortigara Giorgio
Published: March 2023

Domestic chicks (Gallus gallus domesticus) have been widely used as a model to study the motion cues that allow visually naïve organisms to detect animate agents shortly after hatching/birth. Our previous work has shown that chicks prefer to approach agents whose main body axis and motion direction are aligned (a feature typical of creatures whose motion is constrained by a bilaterally symmetric body plan). However, it has never been investigated whether chicks are also sensitive to the fact that an agent maintains a stable front–back body orientation in motion (i.e. consistency in which end is leading and which trailing). This is another feature typical of bilateria, which is also associated with the detection of animate agents in humans. The aim of the present study was to fill this gap. Contrary to our initial expectations, after testing 300 chicks across 3 experimental conditions, we found a recurrent preference for the agent which did not maintain a stable front–back body orientation. Since this preference was limited to female chicks, the results are discussed also in relation to sex differences in the social behaviour of this model. Overall, we show for the first time that chicks can discriminate agents based on the stability of their front–back orientation. The unexpected direction of the effect could reflect a preference for agents’ whose behaviour is less predictable. Chicks may prefer agents with greater behavioural variability, a trait which has been associated with animate agents, or have a tendency to explore agents performing “odd behaviours”.
Epidemiology and clinical presentation of community-acquired Staphylococcus aureus bacteraemia in children under 5 years of age admitted to the Manhiça District Hospital, Mozambique, 2001–2019
Authors: Garrine Marcelino , Quintó Llorenç , Costa Sofia Santos , Messa Augusto , Massinga Arsénia J. , Vubil Delfino , Nhampossa Tacilta , Massora Sérgio , Ácacio Sozinho , Cossa Anélsio , Sigaúque Betuel , Bassat Quique , Couto Isabel , Mandomando Inácio
Published: March 2023

Staphylococcus aureus bacteraemia (SAB) is one of the most common bloodstream infections globally. Data on the burden and epidemiology of community-acquired SAB in low-income countries are scarce but needed to define preventive and management strategies. Blood samples were collected from children < 5 years of age with fever or severe disease admitted to the Manhiça District Hospital for bacterial isolation, including S. aureus. Between 2001 and 2019, 7.6% (3,197/41,891) of children had bacteraemia, of which 12.3% corresponded to SAB. The overall incidence of SAB was 56.1 episodes/100,000 children-years at risk (CYAR), being highest among neonates (589.8 episodes/100,000 CYAR). SAB declined significantly between 2001 and 2019 (322.1 to 12.5 episodes/100,000 CYAR). In-hospital mortality by SAB was 9.3% (31/332), and significantly associated with infections by multidrug-resistant (MDR) strains (14.7%, 11/75 vs. 6.9%, 14/204 among non-MDR, p = 0.043) and methicillin-resistant S. aureus (33.3%, 5/15 vs. 7.6%, 20/264 among methicillin-susceptible S. aureus, p = 0.006). Despite the declining rates of SAB, this disease remains an important cause of death among children admitted to MDH, possibly in relation to the resistance to the first line of empirical treatment in use in our setting, suggesting an urgent need to review current policy recommendations.