bluuebunny/crossref_metadata_2025 huggingface dataset:
Propensity score‐based methods for causal inference and external data leveraging in regulatory settings: From basic ideas to implementation
Authors: Li Heng , Yue Lilly Q.
Published: February 2023

The breakthrough propensity score methodology was formulated by Rosenbaum and Rubin in the 1980s for the mitigation of confounding bias in non‐randomized comparative studies to facilitate causal inference for treatment effects. The methodology had been used mainly in epidemiological and social science studies that may often be exploratory, until it was adopted by FDA/CDRH in 2002 and applied in the evaluation of medical device pre‐market confirmatory studies, including those with a control group extracted from a well‐designed and executed registry database or historical clinical studies. Around 2013, following the Rubin outcome‐free study design principle, the two‐stage propensity score design framework was developed for medical device studies to safeguard study integrity and objectivity, thereby strengthening the interpretability of study results. Since 2018, the scope of the propensity score methodology has been broadened so that it can be used for the purpose of leveraging external data to augment a single‐arm or randomized traditional clinical study. All these statistical approaches, collectively referred to as propensity score‐based methods in this article, have been considered in the design of medical device regulatory studies and stimulated related research, as evidenced by the latest trends in journal publications. We will provide a tutorial on the propensity score‐based methods from the basic idea to their implementation in regulatory settings for causal inference and external data leveraging, along with step‐by‐step descriptions of the procedures of the two‐stage outcome‐free design through examples, which can be used as templates for real study proposals.
A simple algorithm for graph reconstruction
Authors: Mathieu Claire , Zhou Hang
Published: February 2023

How efficiently can we find an unknown graph using distance queries between its vertices? We assume that the unknown graph is connected, unweighted, and has bounded degree. The goal is to find every edge in the graph. This problem admits a reconstruction algorithm based on multi‐phase Voronoi‐cell decomposition and using distance queries. In our work, we analyze a simple reconstruction algorithm. We show that, on random ‐regular graphs, our algorithm uses distance queries. As by‐products, with high probability, we can reconstruct those graphs using queries to an all‐distances oracle or queries to a betweenness oracle, and we bound the metric dimension of those graphs by . Our reconstruction algorithm has a very simple structure, and is highly parallelizable. On general graphs of bounded degree, our reconstruction algorithm has subquadratic query complexity.
Large deviations for subcomplex counts and Betti numbers in multiparameter simplicial complexes
Authors: Samorodnitsky Gennady , Owada Takashi
Published: February 2023

We consider the multiparameter random simplicial complex as a higher dimensional extension of the classical Erdős–Rényi graph. We investigate appearance of “unusual” topological structures in the complex from the point of view of large deviations. We first study upper tail large deviation probabilities for subcomplex counts, deriving the order of magnitude of such probabilities at the logarithmic scale precision. The obtained results are then applied to analyze large deviations for the number of simplices of the multiparameter simplicial complexes. Finally, these results are also used to deduce large deviation estimates for Betti numbers of the complex in the critical dimension.
Bimetallic Phosphide Heterostructure Coupled with Ultrathin Carbon Layer Boosting Overall Alkaline Water and Seawater Splitting
Authors: Li Jingwen , Hu Yezhou , Huang Xiao , Zhu Ye , Wang Deli
Published: February 2023

Seawater electrolysis is promising for green hydrogen production but hindered by the sluggish reaction kinetics of both cathode and anode, as well as the detrimental chlorine chemistry environment. Herein, a self‐supported bimetallic phosphide heterostructure electrode strongly coupled with an ultrathin carbon layer on Fe foam (C@CoP‐FeP/FF) is constructed. When used as an electrode for the hydrogen and oxygen evolution reactions (HER/OER) in simulated seawater, the C@CoP‐FeP/FF electrode shows overpotentials of 192 mV and 297 mV at 100 mA cm−2, respectively. Moreover, the C@CoP‐FeP/FF electrode enables the overall simulated seawater splitting at the cell voltage of 1.73 V to achieve 100 mA cm−2, and operate stably during 100 h. The superior overall water and seawater splitting properties can be ascribed to the integrated architecture of CoP‐FeP heterostructure, strongly coupled carbon protective layer, and self‐supported porous current collector. The unique composites can not only provide enriched active sites, ensure prominent intrinsic activity, but also accelerate the electron transfer and mass diffusion. This work confirms the feasibility of an integration strategy for the manufacturing of a promising bifunctional electrode for water and seawater splitting.
Research on Signal Processing Technology of Ultrasonic Non‐Destructive Testing Based on EEMD Combined with Wavelet Packet
Authors: Li Songsong , Yang Ying , Li Chen , He Huimin , Zhang Qi , Zhao Siqi
Published: February 2023

When processing ultrasonic non‐destructive testing signals, the ensemble empirical mode decomposition (EEMD) method can eliminate the phenomenon of modal aliasing, and the processing effect is better than the empirical mode decomposition (EMD) method. However, in signal reconstruction, the intrinsic mode function (IMF) will be eliminated directly, resulting in the loss of some signals and errors. Therefore, a signal processing method of ultrasonic non‐destructive testing based on EEMD combined with wavelet packet is proposed in this paper. In this method, the signal is preprocessed by wavelet packet, and then decomposed by EEMD. The correlation coefficient method is used in reconstruction. This method not only retains the advantages of EEMD, but also uses the characteristics of wavelet packet decomposition of high frequency and low frequency to ensure the integrity of the signal. Finally, the simulation and actual measurement signals are used for verification. Compared with the EEMD algorithm, the signal‐to‐noise ratio is increased by 31.60% and the root mean square error is reduced by 31.63%, and the cross‐correlation coefficient is increased by 22.09%. This method is more suitable for ultrasonic non‐destructive testing signal processing. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Diallyl disulfide downregulating RhoGDI2 induces differentiation and inhibit invasion via the Rac1/Pak1/LIMK1 pathway in human leukemia HL‐60 cells
Authors: Hui Tan , Yiling Jiang , Guangqun Chen , Ran Liu , Hui Ling , Lan Yi , Jie He , Su Qi
Published: February 2023

Leukemia is a type of disease in which hematopoietic stem cells proliferate clonally at the genetic level. We discovered previously by high‐resolution mass spectrometry that diallyl disulfide (DADS), which is one of the effective ingredients of garlic, reduces the performance of RhoGDI2 from APL HL‐60 cells. Although RhoGDI2 is oversubscribed in several cancer categories, the effect of RhoGDI2 in HL‐60 cells has remained unexplained. We aimed to investigate the influence of RhoGDI2 on DADS‐induced differentiation of HL‐60 cells to elucidate the association among the effect of inhibition or over‐expression of RhoGDI2 with HL‐60 cell polarization, migration and invasion, which is important for establishing a novel generation of inducers to elicit leukemia cell polarization. Co‐transfection with RhoGDI2‐targeted miRNAs apparently decreases the malignant biological behavior of cells and upregulates cytopenias in DADS‐treated HL‐60 cell lines, which increases CD11b and decreases CD33 and mRNA levels of Rac1, PAK1 and LIMK1. Meanwhile, we generated HL‐60 cell lines with high‐expressing RhoGDI2. The proliferation, migration and invasion capacity of such cells were significantly increased by the treated with DADS, while the reduction capacity of the cells was decreased. There was a reduction in CD11b and an increase in CD33 production, as well as an increase in the mRNA levels of Rac1, PAK1 and LIMK1. It also confirmed that inhibition of RhoGDI2 attenuates the EMT cascade via the Rac1/Pak1/LIMK1 pathway, thereby inhibiting the malignant biological behavior of HL‐60 cells. Thus, we considered that inhibition of RhoGDI2 expression might be a new therapeutic direction for the treatment of human promyelocytic leukemia. The anti‐cancer property of DADS against HL‐60 leukemia cells might be regulated by RhoGDI2 through the Rac1‐Pak1‐LIMK1 pathway, which provides new evidence for DADS as a clinical anti‐cancer medicine.
Causal shadow and non-local modular flow: from degeneracy to perturbative genesis by correlation
Authors: Chen Liangyu , Wang Huajia
Published: February 2023

Abstract

Causal shadows are bulk space-time regions between the entanglement wedges and the causal wedges, their existence encodes deep aspects of the entanglement wedge reconstruction in the context of subregion duality in AdS/CFT. In this paper, we study the perturbation theory of the causal shadows and their relation to the properties of the associated modular flows. We first revisit the cases of degenerate causal shadows based on known examples, and discuss the origin for their degeneracy via the local nature of the modular flow. We then focus on the perturbative case in which the CFT subregion consists of two spheres separated by a large distance L ≫ R1,2. The RT surfaces still agree with the causal horizons, giving a degenerate causal shadow classically. We compute the corrections to the quantum extremal surfaces (Q.E.S) from the bulk mutual information, which then give rise to a non-degenerate causal shadow at order GN. We end by discussing the causal shadow perturbation theory more generally, in particular we explore the possibility of extracting the positivity conditions characterizing perturbative causal shadows in the boundary CFTs.
Flow equation and fermion gap in the holographic superconductors
Authors: Yuk Taewon , Sin Sang-Jin
Published: February 2023

Abstract

We reconsider the fermion spectral function in the presence of the Cooper pair condensation and identified the interaction type of complex scalar and fermion, which gives consistent results with the expected s-wave superconductor for the first time. We derive the matrix Riccati equation, which allows the precise calculation of the fermion spectral function. Apart from the gap structure, we studied the effect of the chemical potential and the density and compared it with the BCS theory. We found that two theories give similar results in small chemical potential but very different ones in the high-density case, which we attribute to the correlation effect.
Integrable field theories and their CCFT duals
Authors: Kapec Daniel , Tropper Adam
Published: February 2023

Abstract

We compute the Mellin transforms of various two-dimensional integrable S-matrices, providing the first explicit, non-perturbative realizations of celestial CFT. In two dimensions, the Mellin transform is simply the Fourier transform in rapidity space, and the “celestial correlator” has no position dependence. The simplified setting allows us to study the analytic properties of CCFT correlators exactly as a function of the conformal dimensions. We find that the correlators exist as real distributions of the conformal weights, with asymptotics controlled by the mass spectrum and three-point couplings of the model. Coupling these models to a flat space limit of JT gravity preserves integrability and dresses the amplitudes by a rapidly varying gravitational phase. We find that the coupling to gravity smooths out certain singular aspects of the Mellin-transformed correlators.
Anatomy of the electroweak phase transition for dark sector induced baryogenesis
Authors: Carena Marcela , Li Ying-Ying , Ou Tong , Wang Yikun
Published: February 2023

Abstract

We investigate the electroweak phase transition patterns for a recently proposed baryogenesis model with CP violation originated in the dark sector. The model includes a complex scalar singlet-Higgs boson portal, a U(1)l gauge lepton symmetry with a Z′ gauge boson portal and a fermionic dark matter particle. We find a novel thermal history of the scalar sector, featuring a Z2 breaking singlet vacuum in the early Universe driven by a dark Yukawa coupling, that induces a one-step strongly first order electroweak phase transition. We explore the parameter space that generates the observed matter-antimatter asymmetry and dark matter relic abundance, while being consistent with constraints from electric dipole moment, collider searches, and dark matter direct detection bounds. The complex singlet can be produced via the Higgs portal and decays into Standard Model particles after traveling a certain distance. We explore the reach for long-lived singlet scalars at the 13 TeV Large Hadron Collider with $$ \mathcal{L} $$
L
= 139 fb−1 and show its impact on the parameter space of the model. Setting aside currently unresolved theoretical uncertainties, we estimate the gravitational wave signatures detectable at future observatories.
Probing the singularities of the Landau-Gauge gluon and ghost propagators with rational approximants
Authors: Boito D. , Cucchieri A. , London C. Y. , Mendes T.
Published: February 2023

Abstract

We employ Padé approximants in the study of the analytic structure of the four-dimensional SU(2) Landau-gauge gluon and ghost propagators in the infrared regime. The approximants, which are model independent, serve as fitting functions for the lattice data. We carefully propagate the uncertainties due to the fitting procedure, taking into account all possible correlations. For the gluon-propagator data, we confirm the presence of a pair of complex poles at $$ {p}_{\textrm{pole}}^2 $$

p
pole
2

= [(−0.37 ± 0.05stat± 0.08sys) ± i (0.66 ± 0.03stat± 0.02sys)] GeV2, where the first error is statistical and the second systematic. The existence of this pair of complex poles, already hinted upon in previous works, is thus put onto a firmer basis, thanks to the model independence and to the careful error propagation of our analysis. For the ghost propagator, the Padés indicate the existence of a single pole at p2 = 0, as expected. In this case, our results also show evidence of a branch cut along the negative real axis of p2. This is corroborated with another type of approximant, the D-Log Padés, which are better suited to studying functions with a branch cut and are applied here for the first time in this context. Due to particular features and limited statistics of the gluon-propagator data, our analysis is inconclusive regarding the presence of a branch cut in the gluon case.
Gravity as a gapless phase and biform symmetries
Authors: Hinterbichler Kurt , Hofman Diego M. , Joyce Austin , Mathys Grégoire
Published: February 2023

Abstract

We study effective field theories (EFTs) enjoying (maximal) biform symmetries. These are defined by the presence of a conserved (electric) current that has the symmetries of a Young tableau with two columns of equal length. When these theories also have a topological (magnetic) biform current, its conservation law is anomalous. We go on to show that this mixed anomaly uniquely fixes the two-point function between the electric and magnetic currents. We then perform a Källén-Lehmann spectral decomposition of the current-current correlator, proving that there is a massless mode in the spectrum, whose masslessness is protected by the anomaly. Furthermore, the anomaly gives rise to a universal form of the EFT whose most relevant term — which resembles the linear Einstein action — dominates the infrared physics. As applications of this general formalism, we study the theories of a Galileon superfluid and linearized gravity. Thus, one can view the masslessness of the graviton as being protected by the anomalous biform symmetries. The associated EFT provides an organizing principle for gravity at low energies in terms of physical symmetries, and allows interactions consistent with linearized diffeomorphism invariance. These theories are not ultraviolet-complete — the relevant symmetries can be viewed as emergent — nor do they include the nonlinearities necessary to make them fully diffeomorphism invariant, so there is no contradiction with the expectation that quantum gravity cannot have any global symmetries.
A unified picture of medium-induced radiation
Authors: Isaksen Johannes Hamre , Takacs Adam , Tywoniuk Konrad
Published: February 2023

Abstract

We revisit the picture of jets propagating in the quark-gluon plasma. In addition to vacuum radiation, partons scatter on the medium constituents resulting in induced emissions. Analytical approaches to including these interactions have traditionally dealt separately with multiple, soft, or rare, hard scatterings. A full description has so far only been available using numerical methods. We achieve full analytical control of the relevant scales and map out the dominant physical processes in the full phase space. To this aim, we extend existing expansion schemes for the medium-induced spectrum to the Bethe-Heitler regime. This covers the whole phase space from early to late times, and from hard splittings to emissions below the thermal scale. Based on the separation of scales, a space-time picture naturally emerges: at early times, induced emissions start to build from rare scatterings with the medium. At a later stage, induced emissions due to multiple soft scatterings result in a turbulent cascade that rapidly degrades energy down to, and including, the Bethe-Heitler regime. We quantify the impact of such an improved picture, compared to the current state-of-the-art factorization that includes only soft scatterings, by both analytical and numerical methods for the medium-induced energy distribution function. Our work serves to improve our understanding of jet quenching from small to large systems and for future upgrades of Monte Carlo generators.
Unfolded Fierz-Pauli equations in three-dimensional asymptotically flat spacetimes
Authors: Ammon Martin , Pannier Michel
Published: February 2023

Abstract

We utilise a quotient of the universal enveloping algebra of the Poincaré algebra in three spacetime dimensions, on which we formulate a covariant constancy condition. The equations so obtained contain the Fierz-Pauli equations for non-interacting, massive higher-spin fields, and can thus be regarded as an unfolding of the Fierz-Pauli system. All fundamental fields completely decouple from each other. In the non-truncated case, the field content includes infinitely many copies of each field at fixed spin.
Local spatial densities for composite spin-3/2 systems
Authors: Alharazin H. , Sun B.-D. , Epelbaum E. , Gegelia J. , Meißner U.-G.
Published: February 2023

Abstract

The definition of local spatial densities by using sharply localized one-particle states is applied to spin-3/2 systems. Matrix elements of the electromagnetic current and the energy-momentum tensor are considered and integral expressions of associated spatial distributions in terms of form factors are derived.
Perfecting one-loop BCJ numerators in SYM and supergravity
Authors: Edison Alex , He Song , Johansson Henrik , Schlotterer Oliver , Teng Fei , Zhang Yong
Published: February 2023

Abstract

We take a major step towards computing D-dimensional one-loop amplitudes in general gauge theories, compatible with the principles of unitarity and the color-kinematics duality. For n-point amplitudes with either supersymmetry multiplets or generic non-supersymmetric matter in the loop, simple all-multiplicity expressions are obtained for the maximal cuts of kinematic numerators of n-gon diagrams. At n = 6, 7 points with maximal supersymmetry, we extend the cubic-diagram numerators to encode all contact terms, and thus solve the long-standing problem of simultaneously realizing the following properties: color-kinematics duality, manifest locality, optimal power counting of loop momenta, quadratic rather than linearized Feynman propagators, compatibility with double copy as well as all graph symmetries. Color-kinematics dual representations with similar properties are presented in the half-maximally supersymmetric case at n = 4, 5 points. The resulting gauge-theory integrands and their supergravity counterparts obtained from the double copy are checked to reproduce the expected ultraviolet divergences.
Constraints on the hadronic light-by-light in the Melnikov-Vainshtein regime
Authors: Bijnens Johan , Hermansson-Truedsson Nils , Rodríguez-Sánchez Antonio
Published: February 2023

Abstract

The muon anomalous magnetic moment continues to attract attention due to the possible tension between the experimentally measured value and the theoretical Standard Model prediction. With the aim to reduce the uncertainty on the hadronic light-by-light contribution to the magnetic moment, we derive short-distance constraints in the Melnikov-Vainshtein regime which are useful for data-driven determinations. In this kinematical region, two of the four electromagnetic currents are close in the four-point function defining the hadronic light-by-light tensor. To obtain the constraints, we develop a systematic operator product expansion of the tensor in question to next-to-leading order in the expansion in operators. We evaluate the leading in αs contributions and derive constraints for the next-to-leading operators that are also valid nonperturbatively.
Tailoring flow behavior and heat transfer in tempering channels for high-pressure die casting—analysis of potentials of commercial static mixers and prospects of additive manufacturing
Authors: Sode Marco , Kahlert Moritz , Arold Tizian , Fros Adam Peter , Vollmer Malte , Niendorf Thomas , Fehlbier Martin
Published: February 2023

Additive manufacturing (AM) opens up manifold possibilities to influence the heat transfer between fluid and die in high-pressure die casting (HPDC), eventually allowing to minimize the total cycle time of the process. AM already has been exploited to establish near-contour temperature control systems in industrial applications. However, AM not only allows to influence the position of tempering channels in dies but it also allows to influence the fluid dynamics itself, e.g., by imprinted static mixers. Up to now, such flow-influencing mixing elements have not been considered in metal AM. In the present work, the impact of such metallic static mixers and most relevant processing conditions is investigated experimentally as well by computational fluid dynamics (CFD) simulation. In a first step, conventional static mixer elements are integrated into straight tempering channels to stimulate turbulences of the flowing tempering medium, finally resulting in an increase of the heat transfer up to 33%. In a second step, laser-based powder bed fusion of metals (PBF-LB/M) is applied to realize static mixers. Results obtained reveal that tempering channels without negative influences on the general flow behavior compared to conventional static mixers in straight tempering channels can be realized. In conclusion, the presented results show a positive impact on heat transfer and, thus, allow to further increase the economic efficiency of the HPDC process.
The short-term impact of the 2020 pandemic lockdown on employment in Greece
Authors: Betcherman Gordon , Giannakopoulos Nicholas , Laliotis Ioannis , Pantelaiou Ioanna , Testaverde Mauro , Tzimas Giannis
Published: February 2023

This paper analyzes the short-term employment impact of the COVID-19 lockdown in Greece during the first few months following the pandemic onset. During the initial lockdown period, aggregate employment was lower by almost 9 percentage points than it would have been expected based on pre-pandemic employment trends. However, due to a government intervention that prohibited layoffs, this was not due to higher separation rates. The overall short-term employment impact was due to lower hiring rates. To uncover the mechanism behind this, we use a difference-in-differences framework, and show that tourism-related activities, which are exposed to seasonal variation, had significantly lower employment entry rates in the months following the pandemic onset compared to non-tourism activities. Our results highlight the relevance of the timing of unanticipated shocks in economies with strong seasonal patterns, and the relative effectiveness of policy interventions to partly absorb the consequences of such shocks.
Preliminary clinical study of personalized neoantigen vaccine therapy for microsatellite stability (MSS)-advanced colorectal cancer
Authors: Yu Yao-Jun , Shan Na , Li Li-Yi , Zhu Yue-Sheng , Lin Li-Miao , Mao Chen-Chen , Hu Ting-Ting , Xue Xiang-Yang , Su Xiao-Ping , Shen Xian , Cai Zhen-Zhai
Published: February 2023

Immunotherapy based on immune checkpoint inhibitors (ICIs) has provided revolutionary results in treating various cancers. However, its efficacy in colorectal cancer (CRC), especially in microsatellite stability-CRC, is limited. This study aimed to observe the efficacy of personalized neoantigen vaccine in treating MSS–CRC patients with recurrence or metastasis after surgery and chemotherapy. Candidate neoantigens were analyzed from whole-exome and RNA sequencing of tumor tissues. The safety and immune response were assessed through adverse events and ELISpot. The clinical response was evaluated by progression-free survival (PFS), imaging examination, clinical tumor marker detection, circulating tumor DNA (ctDNA) sequencing. Changes in health-related quality of life were measured by the FACT-C scale. A total of six MSS–CRC patients with recurrence or metastasis after surgery and chemotherapy were administered with personalized neoantigen vaccines. Neoantigen-specific immune response was observed in 66.67% of the vaccinated patients. Four patients remained progression-free up to the completion of clinical trial. They also had a significantly longer progression-free survival time than the other two patients without neoantigen-specific immune response (19 vs. 11 months). Changes in health-related quality of life improved for almost all patients after the vaccine treatment. Our results shown that personalized neoantigen vaccine therapy is likely to be a safe, feasible and effective strategy for MSS–CRC patients with postoperative recurrence or metastasis.
The evolution of dynamic and flexible courtship displays that reveal individual quality
Authors: Hollon Samuel H. , García-Ruiz Irene , Veen Thor , Fawcett Tim W.
Published: February 2023

Sexual selection is a major force shaping morphological and behavioral diversity. Existing theory focuses on courtship display traits such as morphological ornaments whose costs and benefits are assumed be to fixed across individuals’ lifetimes. In contrast, empirically observed displays are often inherently dynamic, as vividly illustrated by the acrobatic dances, loud vocalizations, and vigorous motor displays involved in courtship behavior across a broad range of taxa. One empirically observed form of display flexibility occurs when signalers adjust their courtship investment based on the number of rival signalers. The predictions of established sexual selection theory cannot readily be extended to such displays because display expression varies between courtship events, such that any given display may not reliably reflect signaler quality. We thus lack an understanding of how dynamic displays coevolve with sexual preferences and how signalers should tactically adjust their display investment across multiple courtship opportunities. To address these questions, we extended an established model of the coevolution of a female sexual preference and a male display trait to allow for flexible, dynamic displays. We find that such a display can coevolve with a sexual preference away from their naturally selected optima, though display intensity is a weaker signal of male quality than for non-flexible displays. Furthermore, we find that males evolve to decrease their display investment when displaying alongside more rivals. This research represents a first step towards generalizing the findings of sexual selection theory to account for the ubiquitous dynamism of animal courtship.

Significance statement

Animal courtship displays are typically costly for survival: songs attract predators; dances are exhausting; extravagant plumage is cumbersome. Because of the trade-off between mating benefits and survival costs, displaying individuals often vary their displays across time, courting more intensely when the potential benefit is higher or the cost is lower. Despite the ubiquity of such adjustment in nature, existing theory cannot account for how this flexibility might affect the coevolution of displays with sexual preferences, nor for the patterns of tactical display adjustment that might result, because those models treat displays as static, with fixed costs and benefits. Generalizing a well-studied model of sexual selection, we find that a static display and a flexible display can evolve under similar conditions. Our model predicts that courtship should be less intense when more competitors are present.
Bumblebee cognitive abilities are robust to changes in colony size
Authors: Hill Luke , Gérard Maxence , Hildebrandt Frida , Baird Emily
Published: February 2023

Eusocial insect colonies act as a superorganism, which can improve their ability to buffer the negative impact of some anthropogenic stressors. However, this buffering effect can be affected by anthropogenic factors that reduce their colony size. A reduction in colony size is known to negatively affect several parameters like brood maintenance or thermoregulation, but the effects on behaviour and cognition have been largely overlooked. It remains unclear how a sudden change in group size, such as that which might be caused by anthropogenic stressors, affects individual behaviour within a colony. In this study, the bumblebeeBombus terrestriswas used to study the effect of social group size on behaviour by comparing the associative learning capabilities of individuals from colonies that were unmanipulated, reduced to a normal size (a colony of 100 workers) or reduced to a critically low but functional size (a colony of 20 workers). The results demonstrated that workers from the different treatments performed equally well in associative learning tasks, which also included no significant differences in the learning capacity of workers that had fully developed after the colony size manipulation. Furthermore, we found that the size of workers had no impact on associative learning ability. The learning abilities of bumblebee workers were thus resilient to the colony reduction they encountered. Our study is a first step towards understanding how eusocial insect cognition can be impacted by drastic reductions in colony size.

Significance statement

While anthropogenic stressors can reduce the colony size of eusocial insects, the impact of this reduction is poorly studied, particularly among bumblebees. We hypothesised that colony size reduction would affect the cognitive capacity of worker bumblebees as a result of fewer social interactions or potential undernourishment. Using differential conditioning, we showed that drastic reductions in colony size have no effect on the associative learning capabilities of the bumblebeeBombus terrestrisand that this was the same for individuals that were tested just after the colony reduction and individuals that fully developed under the colony size reduction. We also showed that body size did not affect learning capabilities. This resilience could be an efficient buffer against the ongoing impacts of global change.
Mineralogical characterization of fluorescent grossular garnet var. tsavorite from Merelani Hills, Tanzania
Authors: Idini Alfredo , Angeli Celestino , Frau Franco , Ennas Guido , Naitza Stefano , De Giudici Giovanni Battista , Argazzi Roberto
Published: February 2023

Tsavorite is the trade name for the green vanadium–chromium variety of grossular occurring in the Precambrian terrains in the areas of Merelani Hills (Tanzania) and Tsavo Park (Kenya) which are by far the most important source of gem grade specimens of tsavorite used for high jewellery. The tsavorite crystals from Merelani Hills exhibit a pink-red and yellow fluorescence when irradiated by common portable UV lamp, an unusual phenomenon among members of the garnet group. The electron density map calculated from the diffraction data and plotted against a grossular standard shows that an excess of negative charge is clearly pinpointed in the crystallographic site occupied by Al3+. The bulk elemental analysis shows that the most represented end-member, besides grossular, is the vanadium-bearing goldmanite garnet (3.82–4.08 mol %). The fluorometry with an excitation beam at 408 nm indicates a complex emission pattern with the most intense emissions at 701 and 716 nm and subordinately at 592 nm. The colour perception is dominated by the emission yellow band at 592 nm while the contribution of the red band modulates the colour ranging from bright orange to pink-red. The attribution of the emission at 592 nm is related to Mn2+ while the emissions at 701 and 716 nm could be related to the chromium content and/or to a possible fraction of vanadium as V2+. Because of the characteristic colour perceived under UV light, the use of a common led lamp can be useful as a diagnostic tool to easily identify tsavorite.
Comparison of Safety and Efficacy after Emergency Stenting in Patients Exhibiting Intracranial Atherosclerotic Stenosis Associated with Large-vessel Occlusion with and without Intravenous Infusion of Tirofiban
Authors: Garayzade Rana , Berlis Ansgar , Schiele Stefan , Schneider Hauke , Ertl Michael , Müller Gernot , Maurer Christoph J.
Published: February 2023

Purpose

Intracranial rescue stent angioplasty is a bailout strategy for acute stroke patients in cases of unsuccessful endovascular thrombectomy due to underlying atherosclerotic stenosis. However, there is no consensus on a preprocedural and intraprocedural antiplatelet regimen. The aim of this single-centre study was to compare the safety and efficacy of emergency stenting in patients exhibiting intracranial atherosclerotic stenosis-related acute large-vessel occlusion with or without peri-interventional intravenous infusion of tirofiban.

Materials and Methods

We performed a retrospective analysis of 78 patients who were treated with rescuestent angioplasty between 2010 and 2019 due to acute ischaemic stroke. The patients were divided into 2 groups: those who received peri-interventional intravenous tirofiban and those who did not receive tirofiban. We compared clinical safety and functional outcomes in both treatment groups with symptomatic haemorrhage as the primary endpoint. Bivariate and multivariable logistic regression was performed to investigate the association between tirofiban and outcome measures.

Results

Thirty-seven patients were treated with intravenous tirofiban (47.4%), and 41 patients did not receive intravenous tirofiban (52.6%). Statistical analysis revealed no significant difference between the two groups in the rate of symptomatic haemorrhage (16.2% in the tirofiban group versus 14.6% in the control group, p = 0.847). The 3-month mortality (21.6% in the tirofiban group versus 17.1% in the control group, p = 0.611) and good functional outcomes according to the modified Rankin scale (45.9% versus 34.1%, p = 0.289) were comparable.

Conclusion

The results of our study suggest that the application of tirofiban for rescue stenting after failed mechanical thrombectomy is safe.
Postoperative morbidity and mortality in pediatric indigenous populations: a scoping review and meta-analysis
Authors: Livergant Rachel J. , Fraulin Georgia , Stefanyk Kelsey , Binda Catherine , Maleki Sasha , Joharifard Shahrzad , Hillier Tracey , Joos Emilie
Published: February 2023

Mounting evidence suggests that childhood health is an important predictor of wellness as an adult. Indigenous peoples worldwide suffer worse health outcomes compared to settler populations. No study comprehensively evaluates surgical outcomes for Indigenous pediatric patients. This review evaluates inequities between Indigenous and non-Indigenous children globally for postoperative complications, morbidities, and mortality. Nine databases were searched for relevant subject headings including “pediatric”, “Indigenous”, “postoperative”, “complications”, and related terms. Main outcomes included postoperative complications, mortality, reoperations, and hospital readmission. A random-effects model was used for statistical analysis. The Newcastle Ottawa Scale was used for quality assessment. Fourteen studies were included in this review, and 12 met inclusion criteria for meta-analysis, representing 4793 Indigenous and 83,592 non-Indigenous patients. Indigenous pediatric patients had a greater than twofold overall (OR 2.0.6, 95% CI 1.23–3.46) and 30-day postoperative mortality (OR 2.23, 95% CI 1.23–4.05) than non-Indigenous populations. Surgical site infections (OR 1.05, 95% CI 0.73–1.50), reoperations (OR 0.75, 95% CI 0.51–1.11), and length of hospital stay (SMD = 0.55, 95% CI − 0.55–1.65) were similar between the two groups. There was a non-significant increase in hospital readmissions (OR 6.09, 95% CI 0.32–116.41, p = 0.23) and overall morbidity (OR 1.13, 95% CI 0.91–1.40) for Indigenous children. Indigenous children worldwide experience increased postoperative mortality. It is necessary to collaborate with Indigenous communities to promote solutions for more equitable and culturally appropriate pediatric surgical care.
Impact of implementation of polymerase chain reaction on diagnosis, treatment, and clinical course of Acanthamoeba keratitis
Authors: Roth Mathias , Balasiu Adriana , Daas Loay , Holtmann Christoph , Servera Anna , Walckling Marcus , MacKenzie Colin R. , Fuchsluger Thomas A. , Geerling Gerd
Published: February 2023

Purpose

Acanthamoeba keratitis (AK) is a painful and possibly sight-threatening ocular infection. While the correct diagnosis and specific treatment in the early stages significantly improve the prognosis, the disease is often misdiagnosed and in clinical examination confused with other forms of keratitis. Polymerase chain reaction (PCR) for the detection of AK was first introduced in our institution in December 2013 to improve the timely diagnosis of AK. The aim of this study was to assess the impact of implementation of Acanthamoeba PCR on the diagnosis and treatment of the disease in a German tertiary referral center.

Patients and methods

Patients treated for Acanthamoeba keratitis between 1st of January 1993 and 31st of December 2021 in the Department of Ophthalmology of the University Hospital Duesseldorf were identified retrospectively via in-house registries. Evaluated parameters include age, sex, initial diagnosis, method of correct diagnosis, duration of symptoms until correct diagnosis, contact lens use, visual acuity, and clinical findings as well as medical and surgical therapy by keratoplasty (pKP). In order to assess the impact of implementation of Acanthamoeba PCR, the cases were divided into two groups (before (pre-PCR group) and after PCR implementation (PCR group).

Results

Seventy-five patients with Acanthamoeba keratitis were included (69.3% female, median age 37 years). Eighty-four percent (63/75) of all patients were contact lens wearers. Until PCR was available, 58 patients with Acanthamoeba keratitis were diagnosed either clinically (n = 28), by histology (n = 21), culture (n = 6), or confocal microscopy (n = 2) with a median duration until diagnosis of 68 (18; 109) days. After PCR implementation, in 17 patients, the diagnosis was established with PCR in 94% (n = 16) and median duration until diagnosis was significantly shorter with 15 (10; 30.5) days. A longer duration until correct diagnosis correlated with a worse initial visual acuity (p = 0.0019, r = 0.363). The number of pKP performed was significantly lower in the PCR group (5/17; 29.4%) than in the pre-PCR group (35/58; 60.3%) (p = 0.025).

Conclusions

The choice of diagnostic method and especially the application of PCR have a significant impact on the time to diagnosis and on the clinical findings at the time of confirmation of diagnosis and the need for penetrating keratoplasty. In contact lens–associated keratitis, the first crucial step is to take AK into consideration and perform a PCR test as timely confirmation of diagnosis of AK is imperative to prevent long-term ocular morbidity.
“More life and more days”—patient and care characteristics in a specialized acute pediatric palliative care inpatient unit
Authors: Stoesslein Sophie , Gramm Julia D. , Bender Hans-Ulrich , Müller Petra , Rabenhorst Dorothee , Borasio Gian Domenico , Führer Monika
Published: February 2023

Only a few acute hospital inpatient units dedicated to pediatric palliative care (PPC) patients exist today. Clinical data on the patients and care provided at specialized acute PPC inpatient units (PPCUs) are scarce. This study aims at describing patient and care characteristics on our PPCU to learn about the complexity and relevance of inpatient PPC. A retrospective chart analysis was performed on the 8-bed PPCU of the Center for Pediatric Palliative Care of the Munich University Hospital, including demographic, clinical, and treatment characteristics (487 consecutive cases; 201 individual patients; 2016–2020). Data were analyzed descriptively; the chi-square test was used for comparisons. Patients’ age (1–35.5 years, median: 4.8 years) and length of stay (1–186 days, median 11 days) varied widely. Thirty-eight percent of patients were admitted repeatedly (range 2–20 times). Most patients suffered from neurological diseases (38%) or congenital abnormalities (34%); oncological diseases were rare (7%). Patients’ predominant acute symptoms were dyspnea (61%), pain (54%), and gastrointestinal symptoms (46%). Twenty percent of patients suffered from > 6 acute symptoms, 30% had respiratory support incl. invasive ventilation, 71% had a feeding tube, and 40% had full resuscitation code. In 78% of cases, patients were discharged home; 11% died on the unit.

Conclusion: This study shows the heterogeneity, high symptom burden, and medical complexity of the patients on the PPCU. The high dependency on life-sustaining medical technology points to the parallelism of life-prolonging and palliative treatments that is typical for PPC. Specialized PPCUs need to offer care at the intermediate care level in order to respond to the needs of patients and families.

What is Known:• Pediatric patients in outpatient PPC or hospices present with a variety of clinical syndromes and different levels of complexity and care intensity.• There are many children with life-limiting conditions (LLC) in hospitals, but specialized PPC hospital units for these patients are rare and poorly described.

What is New:• Patients on a specialized PPC hospital unit show a high symptom burden and a high level of medical complexity, including dependency on medical technology and frequent full resuscitation code.﻿• The PPC unit is mainly a place for pain and symptom management as well as crisis intervention, and needs to be able to offer treatment at the intermediate care level.
Investigation of spatial and temporal variations of airborne Poaceae, Myrtaceae and Cupressaceae pollen and Alternaria spores in Sydney, Australia, 2017–2020
Authors: Jetschni Johanna , Al Kouba Jane , Beggs Paul J. , Jochner-Oette Susanne
Published: February 2023

There is a need for information on pollen exposure to assess allergy risk. Monitoring of aeroallergens in a city is usually limited to the use of a single trap for the whole area. While a single trap provides enough information on background pollen concentration for the area, varying pollen exposure across different urban environments, however, is not considered. In this study, we analysed aerobiological data of three pollen seasons (2017–2020) recorded with a volumetric pollen trap in Sydney, Australia. In order to assess spatial differences in pollen exposure across the city, we installed ten gravimetric traps recording pollen deposition for eight weeks during the summer of 2019/2020. We considered the influence of meteorological variables, land use, urbanisation and distance to the sea. Our results showed differences in pollen season characteristics across the three analysed seasons and correlations with meteorological parameters. Considering all years, we found for Poaceae and Alternaria the strongest positive correlation with mean temperature and for Myrtaceae and Cupressaceae with maximum temperature. Likewise, there were negative correlations with humidity (Myrtaceae, Cupressaceae, Alternaria) and precipitation (Myrtaceae, Cupressaceae). Days with medically relevant pollen and spore concentrations varied between years and we recorded the highest amount in 2017/2018 for Poaceae and Alternaria and in 2019/2020 for Myrtaceae. In addition, we found spatial and temporal variations of pollen deposition. However, we did not detect significant correlations between pollen deposition and land use, which can be attributable to drought conditions prior to the sampling campaign and the temporal setting in the pollen season. This study highlights the importance of continuous volumetric aerobiological monitoring as well as the assessment of pollen exposure at several locations across a large urban area.
Design-based spatial interpolation with data driven selection of the smoothing parameter
Authors: Fattorini Lorenzo , Franceschi Sara , Marcheselli Marzia , Pisani Caterina , Pratelli Luca
Published: February 2023

In the inverse distance weighting interpolation the interpolated, value is a weighted mean of the sampled values, with weights decreasing with the distances. The most widely adopted class of distance functions is the class of negative powers of order $$\alpha $$
α
and the appropriate choice of the smoothing parameter $$\alpha $$
α
is a crucial issue. In this paper, we give sufficient conditions for the design-based consistency of the inverse distance weighting interpolator when $$\alpha $$
α
is selected by cross-validation techniques, and a pseudo-population bootstrap approach is introduced to estimate the accuracy of the resulting interpolator. A simulation study is performed to empirically confirm the theoritical findings and to investigate the finite-sample properties of the interpolator obtained using leave-one-out cross-validation. Moreover, a comparison with the nearest neighbor interpolator, which is the limiting case for $$\alpha =\infty $$

α
=
∞

, is performed. Finally, the estimation of the surface of the Shannon diversity index of tree diameter at breast height in the experimental watershed of Bonis forest (Southern Italy) is described.