bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-time particle motion in one and two-dimensional lattices with site disorder
Authors: Cui Bingyu , Sukharev Maxim , Nitzan Abraham
Published: April 2023

As in the case of a free particle, the initial growth of a broad (relative to lattice spacing) wavepacket placed on an ordered lattice is slow (its time derivative has zero initial slope), and the spread (root mean square displacement) becomes linear in t at a long time. On a disordered lattice, the growth is inhibited for a long time (Anderson localization). We consider site disorder with nearest-neighbor hopping on one- and two-dimensional systems and show via numerical simulations supported by the analytical study that the short time growth of the particle distribution is faster on the disordered lattice than on the ordered one. Such faster spread takes place on time and length scales that may be relevant to the exciton motion in disordered systems.
Nonadiabatic dynamics in a forest of coupled states: Electronic state branching in the VUV photodissociation of N2
Authors: Gelfand Natalia , Komarova Ksenia , Remacle Françoise , Levine Raphael D.
Published: April 2023

Multi-state electronic dynamics at higher excitation energies is needed for the understanding of a variety of energy rich situations, including chemistry under extreme conditions, vacuum ultraviolet (VUV) induced astrochemistry, and attochemistry. It calls for an understanding of three stages, energy acquisition, dynamical propagation, and disposal. It is typically not possible to identify a basis of uncoupled quantum states that is sufficient for the three stages. The handicap is the large number of coupled quantum states that is needed to describe the system. Progress in quantum chemistry provides the necessary background to the energetics and the coupling. Progress in quantum dynamics takes this as input for the propagation in time. Right now, it seems that we have come of age with potential detailed applications. We here report a demonstration to a coupled electron-nuclear quantum dynamics through a maze of 47 electronic states and with attention to the order in perturbation theory that is indicated using propensity rules for couplings. Close agreement with experimental results for the VUV photodissociation of 14N2 and its isotopomer 14N15N is achieved. We pay special attention to the coupling between two dissociative continua and an optically accessible bound domain. The computations reproduce and interpret the non-monotonic branching between the two exit channels producing N(2D) and N(2P) atoms as a function of excitation energy and its variation with the mass.
Ant mediated dispersal of spiny stick insect (Extatosoma tiaratum) eggs and Acacia longifolia seeds is ant-species dependent
Authors: Smart Hannah R. , Andrew Nigel R. , O’Hanlon James C.
Published: April 2023

Myrmecochory is a widespread mutualism between angiosperm plants and ants, where seed dispersal is facilitated by a nutrient-rich appendage known as the elaiosome. Some species of phasmids (Phasmatodea) have convergently evolved an appendage, the egg capitulum, that is analogous to the elaiosome. Research into ant-mediated dispersal of phasmid eggs is limited. It is unknown whether there are species-specific interactions between ants and phasmid eggs, nor if this variation in ant species behaviour towards eggs parallels behaviour towards seeds. We observed the behaviour of five Australian ant species towards Extatosoma tiaratum eggs and Acacia longifolia seeds. We found that ant species show significant variation in the likelihood of dispersing phasmid eggs and plant seeds. Iridomyrmex purpureus removed the largest quantities of eggs and seeds. Rhytidoponera metallica also removed large amounts of seeds but less eggs. Three species did not remove any eggs but removed small amounts of seeds. We found a species-specific component to dispersal of phasmid eggs and seeds by ants, indicating that this mutualism may depend on partner identity and abundance. Although seeds and eggs have convergently evolved to exploit ant behaviours, they elicit different behaviours in certain ant species, highlighting the complex nature of this interaction.
A comparison of ecomorphology between introduced and native Australian dung beetles
Authors: Harvey Alexander , Sherratt Emma
Published: April 2023

Among the many catastrophic introductions of exotic species to Australia, the Australian Dung Beetle Project stands apart as a success story. From 1965 dung beetles (Coleoptera: Scarabaeinae) were introduced for biological control purposes, and 23 species survived to become integrated into the environment with apparently little-to-no competition with native species. To understand this, we investigated ecomorphological diversity in the Australian dung beetle fauna, examining variation in functional traits among rolling and tunnelling species that are native to Australia and introduced. We found that introduced species are, on average, larger than native species of the same nidification strategy, but the size ranges overlap. Native and introduced tunnellers are convergent in body shape, whereas introduced rollers have distinct body shape compared with native species. Rollers and tunnellers also have distinct allometric patterns, where shape variation predicted by size aligns along two diverging allometric trajectories between nidification strategies. Our results suggest that ecomorphological differences do not explain the apparent lack of competition between tunnellers, but this may be the factor for rollers. Also, these results indicate that body size and associated allometric scaling is an important aspect of the ecomorphology of dung beetles that should be considered in future studies.
Cell cycle controls long-range calcium signaling in the regenerating epidermis
Authors: Moore Jessica L. , Bhaskar Dhananjay , Gao Feng , Matte-Martone Catherine , Du Shuangshuang , Lathrop Elizabeth , Ganesan Smirthy , Shao Lin , Norris Rachael , Campamà Sanz Nil , Annusver Karl , Kasper Maria , Cox Andy , Hendry Caroline , Rieck Bastian , Krishnaswamy Smita , Greco Valentina
Published: April 2023

Skin homeostasis is maintained by stem cells, which must communicate to balance their regenerative behaviors. Yet, how adult stem cells signal across regenerative tissue remains unknown due to challenges in studying signaling dynamics in live mice. We combined live imaging in the mouse basal stem cell layer with machine learning tools to analyze patterns of Ca2+ signaling. We show that basal cells display dynamic intercellular Ca2+ signaling among local neighborhoods. We find that these Ca2+ signals are coordinated across thousands of cells and that this coordination is an emergent property of the stem cell layer. We demonstrate that G2 cells are required to initiate normal levels of Ca2+ signaling, while connexin43 connects basal cells to orchestrate tissue-wide coordination of Ca2+ signaling. Lastly, we find that Ca2+ signaling drives cell cycle progression, revealing a communication feedback loop. This work provides resolution into how stem cells at different cell cycle stages coordinate tissue-wide signaling during epidermal regeneration.
AFRIMETS.AUV.A-S2 final report, calibration of a multi-function acoustic calibrator
Authors: Nel R , Potgieter H , Dobrowolska D , Młyńska A , Shawky H A , Maina A , Ojasalo K
Published: April 2023

Main text

Results of Regional Metrology Organisation supplementary comparison AFRIMETS.AUV.A-S2 concerning the calibration of a Brüel & Kjær 4226 multi-frequency sound calibrator are reported here. Sound pressure level results at frequencies from 31.5 Hz to 16 kHz and nominal sound level settings of 94 dB and 114 dB, were evaluated for consistency, the calculated comparison reference values and Degrees of Equivalence are reported here. The comparison's purpose was to prove technical capabilities supporting the submissions of calibration measurement capabilities in the BIPM key comparison database. The light shines quite far, the new calibration measurement capabilities that may result from this work underpin some important fundamental acoustic calibration services, e.g., sound calibrators, sound level meters and personal sound exposure meters. These instruments are intrinsic to the effective monitoring and implementation worldwide of human hearing conservation and hearing loss assessment programs, all of which impacts quality of life. According to the World Health Organization, nearly 1.5 billion people experience some decline in their hearing capacity during their lives [1].

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Infrared effects and the Unruh state
Authors: Anderson Paul R , Gholizadeh Siahmazgi Shohreh , Scofield Zachary P
Published: April 2023

Detailed behaviors of the modes of quantized scalar fields in the Unruh state for various eternal black holes in two dimensions are investigated. It is shown that the late-time behaviors of some of the modes of the quantum fields and of the symmetric two-point function are determined by infrared effects. The nature of these effects depends upon whether there is an effective potential in the mode equation and what form this potential takes. Here, three cases are considered, one with no potential and two with potentials that are nonnegative everywhere and are zero on the event horizon of the black hole and zero at either infinity or the cosmological horizon. Specifically, the potentials are a delta function potential and the potential that occurs for a massive scalar field in Schwarzschild–de Sitter spacetime. In both cases, scattering effects remove infrared divergences in the mode functions that would otherwise arise from the normalization process. When such infrared divergences are removed, it is found that the modes that are positive frequency with respect to the Kruskal time on the past black hole horizon approach zero in the limit that the radial coordinate is fixed and the time coordinate goes to infinity. In contrast, when there is no potential and thus infrared divergences occur, the same modes approach nonzero constant values in the late-time limit when the radial coordinate is held fixed. The behavior of the symmetric two-point function when the field is in the Unruh state is investigated for the case of a delta function potential in certain asymptotically flat black hole spacetimes in two dimensions. The removal of the infrared divergences in the mode functions results in the elimination of terms that grow linearly in time.
Glitch subtraction from gravitational wave data using adaptive spline fitting
Authors: Mohanty Soumya D , Chowdhury Mohammad A T
Published: April 2023

Transient signals of instrumental and environmental origins (‘glitches’) in gravitational wave data elevate the false alarm rate of searches for astrophysical signals and reduce their sensitivity. Glitches that directly overlap astrophysical signals hinder their detection and worsen parameter estimation errors. As the fraction of data occupied by detectable astrophysical signals will be higher in next generation detectors, such problematic overlaps could become more frequent. These adverse effects of glitches can be mitigated by estimating and subtracting them out from the data, but their unpredictable waveforms and large morphological diversity pose a challenge. Subtraction of glitches using data from auxiliary sensors as predictors works but not for the majority of cases. Thus, there is a need for nonparametric glitch mitigation methods that do not require auxiliary data, work for a large variety of glitches, and have minimal effect on astrophysical signals in the case of overlaps. In order to cope with the high rate of glitches, it is also desirable that such methods be computationally fast. We show that adaptive spline fitting, in which the placement of free knots is optimized to estimate both smooth and non-smooth curves in noisy data, offers a promising approach to satisfying these requirements for broadband short-duration glitches, the type that appear quite frequently. The method is demonstrated on glitches drawn from three distinct classes in the Gravity Spy database as well as on the glitch that overlapped the binary neutron star signal GW170817. The impact of glitch subtraction on the GW170817 signal, or those like it injected into the data, is seen to be negligible.
A viable relativistic scalar theory of gravitation
Authors: Bragança Diogo P L
Published: April 2023

We build a self-consistent relativistic scalar theory of gravitation on a flat Minkowski spacetime from a general field Lagrangian. It is shown that, for parameters that satisfy the equivalence principle, this theory predicts the same outcome as general relativity (GR) for every classical solar-system test. This theory also admits gravitational waves that propagate at the speed of light, and the gravitational radiation energy loss in a binary system is shown to be very similar to the GR prediction. We then analyze the strong gravity regime of the theory for a spherically symmetric configuration and find that there is an effective ‘singularity’ near the Schwarzschild radius. The main goal of this work is to show that, contrary to what is commonly believed, there are relativistic scalar theories of gravitation defined on a Minkowski spacetime that are not ruled out by the classical solar system tests of GR.
Computational budget optimization for Bayesian parameter estimation in heavy-ion collisions
Authors: Weiss Brandon , Paquet Jean-François , Bass Steffen A
Published: April 2023

Bayesian parameter estimation provides a systematic approach to compare heavy-ion collision models with measurements, leading to constraints on the properties of nuclear matter with proper accounting of experimental and theoretical uncertainties. Aside from statistical and systematic model uncertainties, interpolation uncertainties can also play a role in Bayesian inference, if the model’s predictions can only be calculated at a limited set of model parameters. This uncertainty originates from using an emulator to interpolate the model’s prediction across a continuous space of parameters. In this work, we study the trade-offs between the emulator (interpolation) and statistical uncertainties. We perform the analysis using spatial eccentricities from the TRENTo model of initial conditions for nuclear collisions. Given a fixed computational budget, we study the optimal compromise between the number of parameter samples and the number of collisions simulated per parameter sample. For the observables and parameters used in the present study, we find that the best constraints are achieved when the number of parameter samples is slightly smaller than the number of collisions simulated per parameter sample.
Calculated residential exposure to power frequency magnetic fields for an epidemiological study in France and comparison to measurements
Authors: Deschamps François , Deambrogio Vincent
Published: April 2023

The GEOCAP epidemiological study of paediatric cancers in relation with various environmental factors is currently being carried out in France. Proximity to high voltage overhead lines (63–400 kV) related to exposure to extremely low frequency magnetic field (ELF-MF) is one of studied factors. The study covers the mainland French territory and includes 4174 leukaemia cases and 45 000 controls recruited from 2002 to 2010. Residential exposure was calculated for 1124 subjects whose distance to power lines was small enough for their residential exposure to possibly exceed the background reference level 0.1 μT. Residential exposure was calculated by modelling all the influencing spans close to the subjects’ residences. At final, 371 subjects out of 1124 have a calculated exposure over 0.1 μT, including 123 subjects over 0.4 μT, i.e. 0.25% of the study population. These 371 calculated exposures exceeding 0.1 μT have been matched to an existing database of ELF-MF measurements performed in inhabited areas crossed by power lines, and measurements were found for 206 subjects. Comparison was possible for 156 of them. After extrapolation of the measured values to match to calculation conditions, the difference between calculations and adjusted measurements was lower than 30% for 124 subjects (80%), with no clear tendency for over/under estimation. Differences higher than 30% have been analysed and explained.
Super-resolution model-based iterative reconstruction for lens-coupled micro-CT imaging
Authors: Zhao Qingxian , Li Jing , Li Yi , Luo Shouhua
Published: April 2023

Lens-coupled high-resolution micro-computed tomography (micro-CT) uses a visible light magnification system behind the x-ray path to achieve higher resolution imaging than conventional micro-CT. However, the spatial resolution is theoretically limited by optical diffraction and mechanical control precision. As a result, the current system resolution is still insufficient for some applications, such as the imaging of biological materials whose structures are on the nanometer scale. To overcome this limitation, a super-resolution algorithm can be employed to improve the image resolution beyond the theoretical upper bound of the ideal spatial resolution of the system. In this work, a super-resolution model-based iterative reconstruction (SR-MBIR) algorithm is proposed based on a lens-coupled high-resolution micro-CT system and a high-precision nano-stage attached to the rotation stage of the system. The algorithm employs a scanning program that dithers the object via the nano-stage to obtain multiple sets of projection images with sub-pixel information. The blur and noise statistical models are introduced into the physical model for iterative reconstruction, allowing for super-resolution, deblurring, and noise suppression. The results of simulation data and actual data show that the SR-MBIR algorithm has a prominent effect in improving image resolution. The reconstructed images have sharper edges, better details, higher signal-to-noise ratio, and can effectively suppress the systematic blur and noise in the imaging process, thus achieving superior interior reconstruction quality.
A modified architecture of a perovskite solar cell with an enhanced optical absorption in the visible spectrum
Authors: Tooghi Alireza , Karimi Yonjali Yousef
Published: April 2023

The incomplete absorption of light in the perovskite solar cells (PSCs) due to the escape of photons and the waste of their energy in the visible spectrum hinders the efficiency of this type of solar cell. Utilizing light-trapping nanostructures and stimulating the device’s plasmonic is an efficient way to increase absorption and reduce the energy losses. In this paper, a novel configuration of a nanostructured PSC with a plasmonic enhancement has been introduced to confine light in the active layer and boost energy harvesting. According to the conducted calculations, the modified configuration supports 23.4% higher short-circuit current density (J
SC) and 21% power conversion efficiency compared to the conventional PSC. In this study, the finite element method has been employed to perform numerical simulations of the examined structures. For modeling and characterizing solar cells, optical physics of the devices is used in conjunction with their electrical physics.
Annealing temperature dependent properties for Ni/Ti/W Ohmic contacts simultaneously formed on n- and p-type 4H-SiC
Authors: Ge Niannian , Wan Caiping , Jin Zhi , Xu Hengyu
Published: April 2023

The paper investigated the annealing temperature dependence of electrical and structural properties for Ni (50 nm)/Ti (60 nm)/W (60 nm) Ohmic contacts simultaneously formed on n- and p-type 4H-SiC by in-depth electrical and physical characterization. With the annealing temperature rising in the range of 900 °C–1050 °C, the specific contact resistances (SCRs) of both n- and p-type Ohmic contacts monotonously decreased with a similar trend in the range of 1 × 10−4–1 × 10−6 Ω cm2, which was favorable for the simultaneous formation of n- and p-type Ohmic contacts with lower SCRs in the active region. For n-type Ohmic contacts, the variation of SCRs with annealing temperatures was correlated to the relative proportion of the total contact area occupied by the (220) plane compared to the other planes for the polycrystalline and textured δ-Ni2Si film at the contact interface characterized by x-ray diffraction. Furthermore, the surface morphology of Ohmic contacts under different annealing temperatures was highly similar with almost identical root mean square roughness of about 6.2 nm measured by atomic force microscopy (AFM), which was thought to be smooth enough for the wire bonding process from the perspective of device applications. The distinct W layer with no evidence of obvious intermixing and the great distance of released free carbon away from the contact surface makes the surface morphology smooth and uniform.
Controlling the light diffraction through a single subwavelength metallic slit via phase gradient
Authors: Li Songsong , Fu Yangyang , Gao Lei , Jiang Jian-Hua , Xu Yadong
Published: April 2023

In this work, we show that the concept of phase gradient metasurfaces provides a versatile way to control the diffraction of light through small holes or slits. As an example, we consider a single subwavelength metallic slit surrounded by air grooves of gradient depth that induces the expected phase gradient. It is found that for normal incident light, the phase gradient can enable unidirectional excitation of surface plasmons, which flow directionally toward the slit, resulting in extraordinary optical transmission beyond that in conventional ways. Using this scheme, unidirectional radiation of an optical dipole located inside the slit can be obtained when different phase gradients are applied to both sides of the metal plate.
Physicochemical properties and AC magnetic field induced heating properties of solvothermally prepared thiospinel: Fe3S4 (greigite) nanoparticles
Authors: Aarathy A R , Lahiri B B , Pillai S Savitha , Philip John
Published: April 2023

The presence of greigite (Fe3S4) nanoparticles in bacterial magnetosomes, and its lower toxicity have emerged as favourable aspects for its potential applications in various bio-medical applications, including magnetic hyperthermia. Despite having a number of intriguing features, systematic research on the heating efficiency of Fe3S4 nanoparticles (MNPs) in an AC magnetic field is scarce, which is primarily due to the difficulties in preparing phase pure greigite MNPs. In this study, greigite MNPs are prepared using a solvothermal approach, utilizing ethylene glycol as a solvent, and surface functionalized with varied concentrations of poly vinyl alcohol (PVA). Studies using powder x-ray diffraction and electron microscopy demonstrate the development of crystalline Fe3S4 MNPs (average crystallite size: 19–23 nm) with flaky or flower-like morphology. X-ray photoelectron spectroscopy indicates that the lattice is composed primarily of iron and sulphur. The existence of bio-compatible PVA polymer on the surface of the coated MNPs is confirmed using Fourier transform infrared spectroscopy. For the uncoated MNPs, the magnetization at 90 kOe and the effective anisotropy energy density values are found to be ∼ 15.2 emu g−1 and ∼ 22.3 kJ m−3, respectively. Due to the improved colloidal stability, magneto-calorimetric experiments reveal higher AC magnetic field induced heating efficiency for the PVA-coated MNPs. The highest specific absorption rate (SAR) is obtained as ∼ 67.8 ± 2.6 W/gFe in the current study, which is several times higher than the previously published values for synthetic Fe3S4 MNPs. Furthermore, for samples with comparable saturation magnetization and crystallite size, SAR is found to increase with initial susceptibility. The in vitro cytotoxicity studies show good bio-compatibility for the prepared greigite MNPs. The experimental findings provide deeper insights into the preparation of Fe3S4 MNPs using a simple solvothermal technique, and its AC magnetic field induced heating efficiency.
Light absorption enhancement of perovskite solar cells by a modified anti-reflection layer with corrugated void-like nanostructure using finite difference time domain methods
Authors: Mulyanti Budi , Anwar Muhammad Raihan , Wulandari Chandra , Hasanah Lilik , Pawinanto Roer Eka , Hamidah Ida , Rusydi Andrivo
Published: April 2023

Perovskite solar cells (PSC) have become a growing research interest due to their flexibility, attractive properties, and low production cost. However, the thin-film structure of PSC often results in a not fully absorbed incident light by the active layer, which is crucial to determine PSC efficiency. Thus, the fabrication of an active layer with unique nanostructures is often used to enhance light absorption and general PSC efficiency. Using the theoretical simulation based-on Finite-Difference Time-Domain (FDTD) technique, this work demonstrates the successful improvement of light absorption by embedding corrugated void-like structure and perovskite thickness modification. The investigation of a corrugated void-type anti-reflection layer effect on light absorption is done by modifying the radius (r) and lattice constant (a) to obtain the optimum geometry. In addition, the MAPbI3 perovskite layer thickness is also adjusted to examine the optimum light absorption within the visible length to near-infrared. The theoretical calculations show that the optimum r = 692 nm and a = 776 nm. Meanwhile, the optimum absorber layer thickness is 750 nm. Compared to flat PSC, our proposed PSC absorbed more light, especially in the near-infrared region. Our result shows demonstrates the successful enhancement of light absorption by embedding corrugated void-like structure and modifying the perovskite thickness using a theoretical simulation based on the FDTD technique.
Wide-angle effects in multi-tracer power spectra with Doppler corrections
Authors: Paul Pritha , Clarkson Chris , Maartens Roy
Published: April 2023

We examine the computation of wide-angle corrections to the galaxy power spectrum including redshift-space distortions and relativistic Doppler corrections, and also including multiple tracers with differing clustering, magnification and evolution biases. We show that the inclusion of the relativistic Doppler contribution, as well as radial derivative terms, are crucial for a consistent wide-angle expansion for large-scale surveys, both in the single and multi-tracer cases. We also give for the first time the wide-angle cross-power spectrum associated with the Doppler magnification-galaxy cross correlation, which has been shown to be a new way to test general relativity.
In the full-sky power spectrum, the wide-angle expansion allows integrals over products of spherical Bessel functions to be computed analytically as distributional functions, which are then relatively simple to integrate over.
We give for the first time a complete discussion and new derivation of the finite part of the divergent integrals of the form ∫0
∞ drrnjℓ
(kr) jℓ'
(qr), which are necessary to compute the wide-angle corrections when a general window function is included. This facilitates a novel method for integrating a general analytic function against a pair of spherical Bessel functions.
Exact solution of slow quench dynamics and nonadiabatic characterization of topological phases
Authors: Wu Rui , Fang Panpan , Sun Chen , Li Fuxiang
Published: April 2023

Previous studies have shown that the bulk topology of single-particle systems can be captured by the band inversion surface or by the spin inversion surface emerging on the time-averaged spin polarization. Most of the studies, however, are based on the single-particle picture even though the systems are fermionic and multi-bands. Here, we study the slow quench dynamics of topological systems with all the valence bands fully occupied, and show that the concepts of band inversion surface and spin inversion surface are still valid. More importantly, the many-particle nonadiabatic quench dynamics is shown to be reduced to a new and nontrivial three-level Landau–Zener model. This nontrivial three-level Landau–Zener problem is then solved analytically by applying the integrability condition and symmetry considerations, and thus adds a new member to the few models that are exactly solvable. Based on the analytical results, the topological spin texture revealed by the time-averaged spin polarization can be applied to characterize the bulk topology and thus provides a direct comparison for future experiments.
Facilitation of controllable excitation in Rydberg atomic ensembles
Authors: Wang Han , Qian Jing
Published: April 2023

Strongly-interacting Rydberg atomic ensembles have shown intense collective excitation effects due to the inclusion of single Rydberg excitation shared by multiple atoms in the ensemble. In this paper we investigate a counter-intuitive Rydberg excitation facilitation with a strongly-interacting atomic ensemble in the strong probe-field regime, which is enabled by the role of a control atom nearby. Differing from the case of a single ensemble, we show that, the control atom's excitation adds to a second two-photon transition onto the doubly-excited Rydberg state, arising an excitation facilitation for the ensemble atoms. Our numerical studies depending on the method of quantum Monte Carlo wave function, exhibit the observation constraints of this excitation facilitation effect under practical experimental conditions. The results obtained can provide a flexible control for the excitation of Rydberg atomic ensembles and participate further uses in developing mesoscopic Rydberg gates for multiqubit quantum computation.
Microwave-assisted synthesis of iron sulfide motifs for electrochemical applications
Authors: Salvatore Kenna L , Tang Christopher R , Bernardez Edelmy Marin , Wesley Weiqiao , Fang Justin , Lee Katherine , Paltis Ariadna , Nevers Chloe , McGuire Scott C , Hurley Nathaniel , Tong Xiao , Takeuchi Esther S , Takeuchi Kenneth J , Marschilok Amy C , Wong Stanislaus S
Published: April 2023

The syntheses of FeS2 and Fe3S4 nanomaterials were optimized using a novel facile, surfactant-free, and microwave-assisted, one-pot synthesis method, run under ambient and reasonably mild reaction conditions. Synthetic parameters, such as metal precursor salt identity, reaction time, reaction temperature, metal:sulfur molar ratios, and solvent combinations, were all systematically investigated and optimized. A series of FeS2 (pyrite) samples was initially fabricated using thioacetamide (TAA) as the sulfur precursor to generate a distinctive, uniform octahedra-based morphology. Switching the sulfur precursor from TAA to L-cysteine resulted in a corresponding transformation in not only chemical composition from FeS2 to an iron thiospinel structure, Fe3S4 (otherwise known as greigite), but also an associated morphological evolution from octahedra to nanosheet aggregates. The study of these materials has enabled crucial insights into the formation mechanisms of these materials under a relatively non-conventional microwave-assisted setting. Furthermore, in separate experiments, multi-walled carbon nanotubes (MWNTs) and graphene were added in with underlying metal sulfide species to create conductive Fe–S/MWNT composites and Fe–S/graphene composites, respectively. The method of addition of either MWNTs or graphene was also explored, wherein an ‘ex-situ’ synthetic procedure was found to be the least disruptive means of attachment and immobilization onto iron sulfide co-reagents as a means of preserving the latter’s inherent composition and morphology. The redox acidity for the parent material and associated composites demonstrates the utility of our as-developed synthetic methods for creating motifs relevant for electrochemical applications, such as energy storage.
Wet-jet milling exfoliated hexagonal boron nitride as industrial anticorrosive pigment for polymeric coatings
Authors: Molina-Garcia Miguel Angel , Bellani Sebastiano , Del Rio Castillo Antonio Esau , Conticello Irene , Gabatel Luca , Zappia Marilena Isabella , Eredia Matilde , Thorat Sanjay , Martin-Garcia Beatriz , Ceseracciu Luca , Piccinni Marco , Bonaccorso Francesco
Published: April 2023

The incorporation of inorganic nanofillers into polymeric matrices represents an effective strategy for the development of smart coatings for corrosion protection of metallic substrates. In this work, wet-jet milling exfoliation was used to massively produce few-layer hexagonal boron nitride (h-BN) flakes as a corrosion-protection pigment in polyisobutylene (PIB)-based composite coatings for marine applications. This approach represents an innovative advance in the application of two-dimensional (2D) material-based composites as corrosion protection systems at the industrial scale. Although rarely used as an organic coating, PIB was selected as a ground-breaking polymeric matrix for our h-BN-based composite coating thanks to its excellent barrier properties. The optimization of the coating indicates that 5 wt.% is the most effective h-BN content, yielding a corrosion rate of the protected structural steel as low as 7.4 × 10−6 mm yr−1. The 2D morphology and hydrophobicity of the h-BN flakes, together with the capability of PIB to act as a physical barrier against corrosive species, are the main reasons behind the excellent anticorrosion performance of our composite coating.
Encrypted machine learning of molecular quantum properties
Authors: Weinreich Jan , Falk von Rudorff Guido , Anatole von Lilienfeld O
Published: April 2023

Large machine learning (ML) models with improved predictions have become widely available in the chemical sciences. Unfortunately, these models do not protect the privacy necessary within commercial settings, prohibiting the use of potentially extremely valuable data by others. Encrypting the prediction process can solve this problem by double-blind model evaluation and prohibits the extraction of training or query data. However, contemporary ML models based on fully homomorphic encryption or federated learning are either too expensive for practical use or have to trade higher speed for weaker security. We have implemented secure and computationally feasible encrypted ML models using oblivious transfer enabling and secure predictions of molecular quantum properties across chemical compound space. However, we find that encrypted predictions using kernel ridge regression models are a million times more expensive than without encryption. This demonstrates a dire need for a compact ML model architecture, including molecular representation and kernel matrix size, that minimizes model evaluation costs.
F. S. Macaulay: From plane curves to Gorenstein rings
Authors: Eisenbud David , Gray Jeremy
Published: April 2023

Francis Sowerby Macaulay began his career working on Brill and Noether’s theory of algebraic plane curves and their interpretation of the Riemann–Roch and Cayley–Bacharach theorems; in fact it is Macaulay who first stated and proved the modern form of the Cayley–Bacharach theorem. Later in his career Macaulay developed ideas and results that have become important in modern commutative algebra, such as the notions of unmixedness, perfection (the Cohen–Macaulay property), and super-perfection (the Gorenstein property), work that was appreciated by Emmy Noether and the people around her. He also discovered results that are now fundamental in the theory of linkage, but this work was forgotten and independently rediscovered much later. The name of a computer algebra program (now Macaulay2) recognizes that much of his work is based on examples created by refined computation.

Though he never spoke of the connection, the threads of Macaulay’s work lead directly from the problems on plane curves to his later theorems. In this paper we will explain what Macaulay did, and how his results are connected.
Adverse childhood experiences and the development of multimorbidity across adulthood—a national 70-year cohort study
Authors: Chandrasekar Rahul , Lacey Rebecca E , Chaturvedi Nishi , Hughes Alun D , Patalay Praveetha , Khanolkar Amal R
Published: April 2023

Aim

To examine impact of adverse childhood experiences (ACE) on rates and development of multimorbidity across three decades in adulthood.

Methods

Sample: Participants from the 1946 National Survey of Health and Development, who attended the age 36 assessment in 1982 and follow-up assessments (ages 43, 53, 63, 69; N = 3,264, 51% males). Prospectively collected data on nine ACEs was grouped into (i) psychosocial, (ii) parental health and (iii) childhood health. For each group, we calculated cumulative ACE scores, categorised into 0, 1 and ≥2 ACEs. Multimorbidity was estimated as the total score of 18 health disorders.

Serial cross-sectional linear regression was used to estimate associations between grouped ACEs and multimorbidity during follow-up. Longitudinal analysis of ACE-associated changes in multimorbidity trajectories across follow-up was estimated using linear mixed-effects modelling for ACE groups (adjusted for sex and childhood socioeconomic circumstances).

Findings

Accumulation of psychosocial and childhood health ACEs were associated with progressively higher multimorbidity scores throughout follow-up. For example, those with ≥2 psychosocial ACEs experienced 0.20(95% CI 0.07, 0.34) more disorders at age 36 than those with none, rising to 0.61(0.18, 1.04) disorders at age 69.

All three grouped ACEs were associated with greater rates of accumulation and higher multimorbidity trajectories across adulthood. For example, individuals with ≥2 psychosocial ACEs developed 0.13(−0.09, 0.34) more disorders between ages 36 and 43, 0.29(0.06, 0.52) disorders between ages 53 and 63, and 0.30(0.09, 0.52) disorders between ages 63 and 69 compared with no psychosocial ACEs.

Interpretations

ACEs are associated with widening inequalities in multimorbidity development in adulthood and early old age. Public health policies should aim to reduce these disparities through individual and population-level interventions.
Transformations of marginal zone lymphomas and lymphoplasmacytic lymphomas: Report from the 2021 SH/EAHP Workshop
Authors: Cook James R , Amador Catalina , Czader Magdalena , Duffield Amy , Goodlad John , Ott German , Xiao Wenbin , Dave Sandeep , Thakkar Devang , Thacker Elizabeth , Dogan Ahmet , Wasik Mariusz , Nejati Reza
Published: April 2023

Objectives

To summarize the conclusions of the 2021 Society for Hematopathology/European Association for Haematopathology workshop regarding transformations of marginal zone lymphoma (MZL) and lymphoplasmacytic lymphoma (LPL).

Methods

Nineteen cases were submitted to this portion of the workshop. Additional studies were performed in cases with sufficient material.

Results

Cases included splenic MZL (n = 4), splenic diffuse red pulp small B-cell lymphoma (n = 2), nodal MZL (n = 4), extranodal MZL (n = 1), and LPL (n = 8). The most common transformation was to diffuse large B-cell lymphoma (DLBCL), but others included classic Hodgkin lymphoma, high-grade B-cell lymphomas with MYC and BCL6 rearrangements, plasmablastic lymphoma, and plasma cell leukemia. Two splenic MZLs with transformation to DLBCL contained t(14;19)(q32;q13.3) IGH::BCL3 rearrangements in both samples. Paired sequencing studies in 5 MZLs with transformation to clonally related DLBCL identified a variety of mutations and gene fusions at the time of transformation, including CARD11, IGH::MYC, NOTCH2, P2RY8, TBLX1X1, and IGH::CD274.

Conclusions

Marginal zone lymphoma and LPL may undergo a variety of transformation events, most commonly to DLBCL, which is usually, although not always, directly clonally related to the underlying low-grade lymphoma. Multiparameter analysis including broad-based sequencing studies can assist in the diagnosis and classification of these uncommon cases.
The Clinical Laboratory Is an Integral Component to Health Care Delivery : An Expanded Representation of the Total Testing Process
Authors: Lubin Ira M , Astles J Rex , Bunn Jake D , Cornish Nancy E , Lazaro Gerardo , Marshall Ashley A , Stang Heather L , De Jesús Victor R
Published: April 2023

Objectives

Developing an expanded representation of the total testing process that includes contemporary elements of laboratory practice can be useful to understanding and optimizing testing workflows across clinical laboratory and patient care settings.

Methods

Published literature and meeting reports were used by the coauthors to inform the development of the expanded representation of the total testing process and relevant examples describing its uses.

Results

A visual representation of the total testing process was developed and contextualized to patient care scenarios using a number of examples covering the detection of blood culture contamination, use of next-generation sequencing, and pharmacogenetic testing.

Conclusions

The expanded representation of the total testing process can serve as a model and framework to document and improve the use of clinical testing within the broader context of health care delivery. This representation recognizes increased engagement among clinical laboratory professionals with patients and other health care providers as essential to making informed decisions. The increasing use of data is highlighted as important to ensuring quality, appropriate test utilization, and sustaining an efficient workflow across clinical laboratory and patient care settings. Maintaining a properly resourced and competent workforce is also featured as an essential component to the testing process.
Development of a conceptual framework for reporting modifications in surgical innovation: scoping review
Authors: Hossaini Sina , Hoffmann Christin , Cousins Sian , Blencowe Natalie , McNair Angus G K , Blazeby Jane M , Avery Kerry N L , Potter Shelley , Macefield Rhiannon
Published: April 2023

Background

Innovative surgical procedures and devices are often modified throughout their development and introduction into clinical practice. A systematic approach to reporting modifications may support shared learning and foster safe and transparent innovation. Definitions of ‘modifications’, and how they are conceptualized and classified so they can be reported and shared effectively, however, are lacking. This study aimed to explore and summarize existing definitions, perceptions, classifications and views on modification reporting to develop a conceptual framework for understanding and reporting modifications.

Methods

A scoping review was conducted in accordance with PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Targeted searches and two database searches were performed to identify relevant opinion pieces and review articles. Included were articles relating to modifications to surgical procedures/devices. Data regarding definitions, perceptions and classifications of modifications, and views on modification reporting were extracted verbatim. Thematic analysis was undertaken to identify themes, which informed development of the conceptual framework.

Results

Forty-nine articles were included. Eight articles included systems for classifying modifications, but no articles reported an explicit definition of modifications. Some 13 themes relating to perception of modifications were identified. The derived conceptual framework comprises three overarching components: baseline data about modifications, details about modifications and impact/consequences of modifications.

Conclusion

A conceptual framework for understanding and reporting modifications that occur during surgical innovation has been developed. This is a first necessary step to support consistent and transparent reporting of modifications, to facilitate shared learning and incremental innovation of surgical procedures/devices. Testing and operationalization is now needed to realize the value of this framework.
Problematising ‘Fused Principles’ in Discourses of Preventative Social Care: Interpreting the Implementation of National Social Services Legislation in Wales, UK
Authors: Read Simon , Verity Fiona , Llewellyn Mark , Tetlow Sion , Richards Jonathan
Published: April 2023

Prevention is a core principle in social care legislation across the UK. However, history shows great variability in how a preventative social care agenda is conceptualised and implemented. We report findings from an independent evaluation of the implementation of the ‘2014 Social Services and Well-being (Wales) Act’ incorporating a document analysis of reports and plans from Wales’ twenty-two local authorities (LAs) and eighty-eight qualitative interviews from social services strategic leaders and operational managers within four Welsh LAs. Analysis highlighted multiple interpretations of national policy, with notable overlapping agendas. In Gramscian terms, there is a constant process of negotiating prevention values and agendas, with consequences for whose interests are served. This was apparent through drives towards cost-saving, financial sustainability and reduced service demand operating alongside values-based principles rooted in well-being and mutualism. Following Kenny’s work in community development, we argue a ‘fusing’ of principles whilst espousing benefits for service users, potentially blurs the aims of the legislation, with implications for practice.
Is phosphorylated tau a good biomarker of synapse pathology in Alzheimer’s disease?
Authors: Saura Carlos A , Parra-Damas Arnaldo
Published: April 2023

This scientific commentary refers to ‘Distinct brain pathologies associated with Alzheimer’s disease biomarker-related phospho-tau 181 and phospho-tau 217 in App knock-in mouse models of amyloid-β amyloidosis’ by Hirota et al. (https://doi.org/10.1093/braincomms/fcac286) and ‘Predictive blood biomarkers and brain changes associated with age-related cognitive decline’ by Saunders et al. (https://doi.org/10.1093/braincomms/fcad113).
Sex-specific life-history trait expression in hybrids of a cave- and surface-dwelling fish (Poecilia mexicana, Poeciliidae)
Authors: Riesch Rüdiger , Arriaga Luis R , Schlupp Ingo
Published: April 2023

Evaluating the fitness of hybrids can provide important insights into genetic differences between species or diverging populations. We focused on surface- and cave-ecotypes of the widespread Atlantic molly Poecilia mexicana and raised F1 hybrids of reciprocal crosses to sexual maturity in a common-garden experiment. Hybrids were reared in a fully factorial 2 × 2 design consisting of lighting (light vs. darkness) and resource availability (high vs. low food). We quantified survival, ability to realize their full reproductive potential (i.e., completed maturation for males and 3 consecutive births for females) and essential life-history traits. Compared to the performance of pure cave and surface fish from a previous experiment, F1s had the highest death rate and the lowest proportion of fish that reached their full reproductive potential. We also uncovered an intriguing pattern of sex-specific phenotype expression, because male hybrids expressed cave molly life histories, while female hybrids expressed surface molly life histories. Our results provide evidence for strong selection against hybrids in the cave molly system, but also suggest a complex pattern of sex-specific (opposing) dominance, with certain surface molly genes being dominant in female hybrids and certain cave molly genes being dominant in male hybrids.