bluuebunny/crossref_metadata_2025 huggingface dataset:
Gravitational Effects on Optical Lens Fabrication: First Insides on Earth- and Microgravity Experiments
Authors: Fütterer Laura , Galati Marco-Nicolas , Reitz Birger , Overmeyer Ludger , Lotz Christoph
Published: September 2024

Understanding the effects of gravity on manufacturing processes is a pioneering extension of the process parameter space used to date. Until now, the improvement of manufacturing technologies has mainly focused on process parameters such as temperature, pressure, and material composition, as access to variable gravity environments is limited. The Einstein-Elevator opens up new possibilities for the variation of these process parameters and the development of in-space manufacturing technologies. Together with the research of innovative production processes for optical components within the PhoenixD Cluster of Excellence, this creates an entirely new field of research. The research presented here focuses on investigating gravity’s effects on dispensed optical lens production. Using a jet dispenser, sessile droplets are produced during a flight phase in the Einstein-Elevator and cured directly by UV polymerization. As part of this study, optical lenses were produced and compared under microgravity and Earth’s gravitational conditions. Geometric properties such as height and contact angle of the lenses produced were analyzed. It was found that lenses fabricated under microgravity have a larger contact angle than those fabricated under Earth gravity. Similarly, the height increases with decreasing gravity. These results are consistent with the theoretical assumptions described, although generalized theories to describe the morphology of a sessile droplet are not yet available. The case study findings on the influence of gravity as a process parameter on drop morphology represent a fundamental improvement for additive manufacturing technologies, especially for in-space manufacturing.
A high-order time-delay difference estimation method for signal enhancement in the distorted towed hydrophone array
Authors: Fan Hailin , Nie Wenxiang , Yao Shuai , An Liang , Yu Fujian , Zhang Ye , Wu Qisong
Published: September 2024

In passive sonar systems, deviations from an ideal linear configuration can significantly impair the beamforming performance of towed hydrophone arrays. This paper presents a method aimed at improving the underwater acoustic signals in the presence of array distortion. The method is centered on a high-order time-delay difference estimation technique utilizing time-frequency autofocus. Initially, a detailed signal model is established that captures the distinctive characteristics of distorted arrays. Subsequently, an algorithm is introduced for high-order time-delay difference estimation to enhance signal fidelity by leveraging phase information within narrowband components originating from incidental acoustic sources. Additionally, a quality metric to evaluate these components is introduced, facilitating the practical implementation of the method. The effectiveness of the proposed approach is validated through both simulation and experimental results, demonstrating its superiority over existing techniques. Importantly, this method does not require prior knowledge of the distortion pattern, making it adaptable to various non-linear array configurations.
Isometric Midthigh-Pull Testing: Reliability and Correlation With Key Functional Capacities in Young Soccer Players
Authors: Rago Vincenzo , Nakamura Fábio Yuzo , Suarez-Balsera Carlos , Arnaiz-Lastras Javier , Figueiredo Pedro
Published: September 2024

Purpose: We examined the reliability of force parameters derived from the isometric midthigh pull (IMTP) and their correlation with the functional capacities of young soccer players. Methods: Data were collected from 20 young professional soccer players within and between 2 sessions (after 1 wk) using a 1000-Hz force plate. Results: Performance outputs in all IMTP parameters were consistent and showed moderate to excellent reliability (intraclass correlation coefficient = .72–1.00) within and between sessions. However, all parameters reported a marginal ability to detect chronic changes in performance (smallest worthwhile change [SWC] < standard error of measurement [SEM]) except for peak vertical force (PF) parameters, which showed good usefulness (SWC > SEM). Absolute PF was correlated with the countermovement-jump (CMJ) total impulse (CMJ-TI; r = .54), whereas relative PF (to body mass) was correlated with CMJ height, CMJ peak power, and the last speed of the 30:15 Intermittent Fitness Test (VIFT; r = .40 to .63). IMTP time-dependent forces were correlated with CMJ-TI (r = .52 to .62). The IMTP impulse parameters were positively correlated with CMJ-TI (r = .48 to .58) and negatively with VIFT (r = −.44 to −.38). None of the IMTP parameters were correlated either with the CMJ mean propulsive force or with any linear acceleration times. Conclusions: All IMTP parameters can be adopted by practitioners involved with testing young soccer players based on their acceptable reliability criteria. However, caution should be taken when interpreting the time-dependent variables based on their marginal usefulness when assessing performance. Generally, a greater PF was associated with a greater vertical power based on its correlation to CMJ.
Enhanced global carbon cycle sensitivity to tropical temperature linked to internal climate variability
Authors: Li Na , Sippel Sebastian , Linscheid Nora , Rödenbeck Christian , Winkler Alexander J. , Reichstein Markus , Mahecha Miguel D. , Bastos Ana
Published: September 2024

The sensitivity of atmospheric CO
2
growth rate to tropical temperature (γ
T
) has almost doubled between 1959 and 2011, a trend that has been linked to increasing drought in the tropics. However, γ
T
has declined since then. Understanding whether these variations in γ
T
reflect forced changes or internal climate variability in the carbon cycle is crucial for future climate projections. We show that doubling sensitivity events can arise in simulations by Earth system models with perturbed initial conditions but are likely explained by internal climate variability. We show that the doubling sensitivity event is associated with the occurrence of a few, but very strong, El Niño events, such as 1982/83 and 1997/98. Such extreme events result in concurrent carbon release by tropical and extratropical ecosystems, increasing the variance of the global land carbon sink and its apparent sensitivity to tropical temperature. Our results imply that the doubling sensitivity does not necessarily indicate a change in carbon cycle response to climate change.
Directional picoantenna behavior of tunnel junctions formed by an atomic-scale surface defect
Authors: Mateos David , Jover Oscar , Varea Miguel , Lauwaet Koen , Granados Daniel , Miranda Rodolfo , Fernandez-Dominguez Antonio I. , Martin-Jimenez Alberto , Otero Roberto
Published: September 2024

Plasmonic nanoantennas have attracted much attention lately, among other reasons because of the directionality of light emitted by fluorophores coupled to their localized surface plasmon resonances. Plasmonic picocavities, i.e., cavities with mode volumes below 1 nm
3
, could act as enhanced antennas due to their extreme field confinement, but the directionality on their emission is difficult to control. In this work, we show that the plasmonic picocavity formed between the tip of a scanning tunneling microscope and a metal surface with a monoatomic step shows directional emission profiles and, thus, can be considered as a realization of a picoantenna. Electromagnetic calculations demonstrate that the observed directionality arises from the reshaping and tilting of the surface charges induced at the scanning tip due to the atomic step. Our results pave the way to exploiting picoantennas as an efficient way for the far-field probing and control of light-matter interactions below the nanoscale.
Targeting the phosphatidylglycerol lipid: An amphiphilic dendrimer as a promising antibacterial candidate
Authors: Zhang Nian , Dhumal Dinesh , Kuo Shanny Hsuan , Lew Shi Qian , Patil Pankaj D. , Taher Raleb , Vaidya Sanika , Galanakou Christina , Elkihel Abdechakour , Oh Myung Whan , Chong Sook Yin , Marson Domenico , Zheng Jun , Rouvinski Oleg , Abolarin Williams O. , Pricl Sabrina , Lau Gee W. , Lee Leo Tsz On , Peng Ling
Published: September 2024

The rapid emergence and spread of multidrug-resistant bacterial pathogens require the development of antibacterial agents that are robustly effective while inducing no toxicity or resistance development. In this context, we designed and synthesized amphiphilic dendrimers as antibacterial candidates. We report the promising potent antibacterial activity shown by the amphiphilic dendrimer
AD1b
, composed of a long hydrophobic alkyl chain and a tertiary amine-terminated poly(amidoamine) dendron, against a panel of Gram-negative bacteria, including multidrug-resistant
Escherichia coli
and
Acinetobacter baumannii.
AD1b
exhibited effective activity against drug-resistant bacterial infections in vivo. Mechanistic studies revealed that
AD1b
targeted the membrane phospholipids phosphatidylglycerol (PG) and cardiolipin (CL), leading to the disruption of the bacterial membrane and proton motive force, metabolic disturbance, leakage of cellular components, and, ultimately, cell death. Together,
AD1b
that specifically interacts with PG/CL in bacterial membranes supports the use of small amphiphilic dendrimers as a promising strategy to target drug-resistant bacterial pathogens and addresses the global antibiotic crisis.
Light-induced magnetization from magnonic rectification
Authors: Kahana Tom , Bustamante Lopez Daniel A. , Juraschek Dominik M.
Published: September 2024

Rectification describes the conversion of an oscillating field or current into a quasi-static one and the most basic example of a rectifier is an AC/DC converter in electronics. This principle can be translated to nonlinear light-matter interactions, where optical rectification converts the oscillating electric field component of light into a quasi-static polarization and phononic rectification converts a lattice vibration into a quasi-static structural distortion. Here, we present a rectification mechanism for magnetism that we call magnonic rectification, where a spin precession is converted into a quasi-static magnetization through the force exerted by a coupled chiral phonon mode. The transiently induced magnetic state resembles that of a canted antiferromagnet, opening an avenue toward creating dynamical spin configurations that are not accessible in equilibrium.
Single-molecule detection and super-resolution imaging with a portable and adaptable 3D-printed microscopy platform (Brick-MIC)
Authors: Moya Muñoz Gabriel G. , Brix Oliver , Klocke Philipp , Harris Paul D. , Luna Piedra Jorge R. , Wendler Nicolas D. , Lerner Eitan , Zijlstra Niels , Cordes Thorben
Published: September 2024

Over the past decades, single-molecule and super-resolution microscopy have advanced and represent essential tools for life science research. There is, however, a growing gap between the state of the art and what is accessible to biologists, biochemists, medical researchers, or labs with financial constraints. To bridge this gap, we introduce Brick-MIC, a versatile and affordable open-source 3D-printed microspectroscopy and imaging platform. Brick-MIC enables the integration of various fluorescence imaging techniques with single-molecule resolution within a single platform and exchange between different modalities within minutes. We here present variants of Brick-MIC that facilitate single-molecule fluorescence detection, fluorescence correlation spectroscopy, time-correlated single-photon counting and super-resolution imaging (STORM and PAINT). Detailed descriptions of the hardware and software components, as well as data analysis routines, are provided, to allow non-optics specialists to operate their own Brick-MIC with minimal effort and investments. We foresee that our affordable, flexible, and open-source Brick-MIC platform will be a valuable tool for many laboratories worldwide.
Long-range repulsion between chromosomes in mammalian oocyte spindles
Authors: Kelleher Colm P. , Rana Yash P. , Needleman Daniel J.
Published: September 2024

During eukaryotic cell division, a microtubule-based structure called the spindle exerts forces on chromosomes. The best-studied spindle forces, including those responsible for the separation of sister chromatids, are directed parallel to the spindle’s long axis. By contrast, little is known about forces perpendicular to the spindle axis, which determine the metaphase plate configuration and thus the location of chromosomes in the subsequent nucleus. Using live-cell microscopy, we find that metaphase chromosomes are spatially anti-correlated in mouse oocyte spindles, evidence of previously unknown long-range forces acting perpendicular to the spindle axis. We explain this observation by showing that the spindle’s microtubule network behaves as a nematic liquid crystal and that deformation of the nematic field around embedded chromosomes causes long-range repulsion between them.
Wirelessly steerable bioelectronic neuromuscular robots adapting neurocardiac junctions
Authors: Tetsuka Hiroyuki , Gobbi Samuele , Hatanaka Takaaki , Pirrami Lorenzo , Shin Su Ryon
Published: September 2024

Biological motions of native muscle tissues rely on the nervous system to interface movement with the surrounding environment. The neural innervation of muscles, crucial for regulating movement, is the fundamental infrastructure for swiftly responding to changes in body tissue requirements. This study introduces a bioelectronic neuromuscular robot integrated with the motor nervous system through electrical synapses to evoke cardiac muscle activities and steer robotic motion. Serving as an artificial brain and wirelessly regulating selective neural activation to initiate robot fin motion, a wireless frequency multiplexing bioelectronic device is used to control the robot. Frequency multiplexing bioelectronics enables the control of the robot locomotion speed and direction by modulating the flapping of the robot fins through the wireless motor innervation of cardiac muscles. The robots demonstrated an average locomotion speed of ~0.52 ± 0.22 millimeters per second, fin-flapping frequency up to 2.0 hertz, and turning locomotion path curvature of ~0.11 ± 0.04 radians per millimeter. These systems will contribute to the expansion of biohybrid machines into the brain-to-motor frontier for developing autonomous biohybrid systems capable of advanced adaptive motor control and learning.
Clinical, mechanistic, and therapeutic landscape of cutaneous fibrosis
Authors: Li Dayan J. , Berry Charlotte E. , Wan Derrick C. , Longaker Michael T.
Published: September 2024

When dysregulated, skin fibrosis can lead to a multitude of pathologies. We provide a framework for understanding the wide clinical spectrum, mechanisms, and management of cutaneous fibrosis encompassing a variety of matrix disorders, fibrohistiocytic neoplasms, injury-induced scarring, and autoimmune scleroses. Underlying such entities are common mechanistic pathways that leverage morphogenic signaling, immune activation, and mechanotransduction to modulate fibroblast function. In light of the limited array of available treatments for cutaneous fibrosis, scientific insights have opened new therapeutic and investigative avenues for conditions that still lack effective interventions.
Exploring the influence of atmospheric CO
2
and O
2
levels on the utility of nitrogen isotopes as proxy for biological N
2
fixation
Authors: Wannicke Nicola , Stüeken Eva E. , Bauersachs Thorsten , Gehringer Michelle M.
Published: September 2024

Biological N
2
fixation (BNF) is traced to the Archean. The nitrogen isotopic fractionation composition (δ
15
N) of sedimentary rocks is commonly used to reconstruct the presence of ancient diazotrophic ecosystems. While δ
15
N has been validated mostly using organisms grown under present-day conditions; it has not under the pre-Cambrian conditions, when atmospheric
p
O
2
was lower and
p
CO
2
was higher. Here, we explore δ
15
N signatures under three atmospheres with (i) elevated CO
2
and no O
2
(Archean), (ii) present-day CO
2
, and O
2
and (iii) future elevated CO
2
, in marine and freshwater, heterocytous cyanobacteria. Additionally, we augment our data set from literature for more generalized dependencies of δ
15
N and the associated fractionation factor epsilon (
ε
= δ
15
N
biomass
– δ
15
N
N2
) during BNF in Archaea and Bacteria, including cyanobacteria, and habitats. The
ε
ranges between 3.70‰ and −4.96‰ with a mean
ε
value of −1.38 ± 0.95‰, for all bacteria, including cyanobacteria, across all tested conditions. The expanded data set revealed correlations of isotopic fractionation of BNF with CO
2
concentrations, toxin production, and light, although within 1‰. Moreover, correlation showed significant dependency of
ε
to species type, C/N ratios and toxin production in cyanobacteria, albeit it within a small range (−1.44 ± 0.89‰). We therefore conclude that δ
15
N is likely robust when applied to the pre-Cambrian-like atmosphere, stressing the strong cyanobacterial bias. Interestingly, the increased fractionation (lower
ε
) observed in the toxin-producing
Nodularia
and
Nostoc
spp. suggests a heretofore unknown role of toxins in modulating nitrogen isotopic signals that warrants further investigation.

IMPORTANCE

Nitrogen is an essential element of life on Earth; however, despite its abundance, it is not biologically accessible. Biological nitrogen fixation is an essential process whereby microbes fix N
2
into biologically usable NH
3
. During this process, the enzyme nitrogenase preferentially uses light
14
N, resulting in
15
N depleted biomass. This signature can be traced back in time in sediments on Earth, and possibly other planets. In this paper, we explore the influence of
p
O
2
and
p
CO
2
on this fractionation signal. We find the signal is stable, especially for the primary producers, cyanobacteria, with correlations to CO

2

, light, and toxin-producing status, within a small range. Unexpectedly, we identified higher fractionation signals in toxin-producing
Nodularia
and
Nostoc
species that offer insight into why some organisms produce these N-rich toxic secondary metabolites.
Sialic acid and PirB are not required for targeting of neural circuits by neurotropic mammalian orthoreovirus
Authors: Griswold Kira A. , Vasylieva Iaroslavna , Smith Megan C. , Fiske Kay L. , Welsh Olivia L. , Roth Alexa N. , Watson Alan M. , Watkins Simon C. , Sutherland Danica M. , Dermody Terence S.
Published: September 2024

Serotype 3 (T3) strains of mammalian orthoreovirus (reovirus) spread to the central nervous system to infect the brain and cause lethal encephalitis in newborn mice. Although reovirus targets several regions in the brain, susceptibility to infection is not uniformly distributed. The neuronal subtypes and anatomic sites targeted throughout the brain are not precisely known. Reovirus binds several attachment factors and entry receptors, including sialic acid (SA)-containing glycans and paired immunoglobulin-like receptor B (PirB). While these receptors are not required for infection of some types of neurons, reovirus engagement of these receptors can influence neuronal infection in certain contexts. To identify patterns of T3 neurotropism, we used microbial identification after passive tissue clearance and hybridization chain reaction to stain reovirus-infected cells throughout intact, optically transparent brains of newborn mice. Three-dimensional reconstructions revealed in detail the sites targeted by reovirus throughout the brain volume, including dense infection of the midbrain and hindbrain. Using reovirus mutants incapable of binding SA and mice lacking PirB expression, we found that neither SA nor PirB is required for the infection of various brain regions. However, SA may confer minor differences in infection that vary by region. Collectively, these studies indicate that many regions in the brain of newborn mice are susceptible to reovirus and that patterns of reovirus infection are not dependent on reovirus receptors SA and PirB.

IMPORTANCE

Neurotropic viruses invade the central nervous system (CNS) and target various cell types to cause disease manifestations, such as meningitis, myelitis, or encephalitis. Infections of the CNS are often difficult to treat and can lead to lasting sequelae or death. Mammalian orthoreovirus (reovirus) causes age-dependent lethal encephalitis in many young mammals. Reovirus infects neurons in several different regions of the brain. However, the complete pattern of CNS infection is not understood. We found that reovirus targets almost all regions of the brain and that patterns of tropism are not dependent on receptors sialic acid and paired immunoglobulin-like receptor B. These studies confirm that two known reovirus receptors do not completely explain the cell types infected in brain tissue and establish strategies that can be used to understand complete patterns of viral tropism in an intact brain.
Epidemiology of childhood invasive pneumococcal disease in Australia: a prospective cohort study
Authors: Phuong Linny Kimly , Cheung Abigail , Templeton Tiarni , Abebe Tamrat , Ademi Zanfina , Buttery Jim , Clark Julia , Cole Theresa , Curtis Nigel , Dobinson Hazel , Shahul Hameed Nadha , Hernstadt Hayley , Ojaimi Samar , Sharp Ella Grace , Sinnaparajar Praisoody , Wen Sophie , Daley Andrew , McMullan Brendan , Gwee Amanda
Published: September 2024

Background

The widespread use of pneumococcal conjugate vaccines (PCV) has changed the epidemiology of invasive pneumococcal disease (IPD) in children globally.

Methods

Multicentre prospective audit of IPD episodes from five paediatric hospitals in Australia over 5.5 years between 2016 and June 2021. Children (<18 years) withStreptococcus pneumoniaeisolated from a sterile site were included.

Results

There were 377 IPD episodes in 375 children: 338 (90%) had received ≥3 PCV doses; 42 (11%) had IPD risk factors. The most common presentations were complicated pneumonia (254, 67%), bacteraemia (65, 17%) and meningitis (29, 8%). Five (1%) children died.

Serotype information was available for 230 (61%) episodes; 140 (61%) were 13vPCV vaccine serotypes (VTs). The majority (85%) of episodes of complicated pneumonia were due to a VT; predominantly 3, 19A, 19F. Children with risk factors were more likely to present with bacteraemia ± sepsis (42% vs 12%) and to have a non-vaccine serotype (NVT) (74% vs 32%). Resistance to ceftriaxone (meningitis cut-off) occurred in 17% of 23B isolates (n=12) and accounted for 22% (5/23) of meningitis cases.

Conclusions

Complicated pneumonia is the most common IPD presentation. NVTs account for the majority of bacteraemia and meningitis episodes. High rates of ceftriaxone resistance for NVT 23B support the addition of vancomycin for empiric treatment of suspected meningitis.
Global rapid review of interventions to tackle the harms of illicit tobacco
Authors: Davies Nathan , Bogdanovica Ilze , Bains Manpreet , Jayes Leah , Langley Tessa Elisabeth
Published: September 2024

Objective

This review aimed to assess interventions designed to reduce harm from illicit tobacco (IT). We evaluated health outcomes, cost-effectiveness, the advantages and disadvantages of interventions, and contextual factors affecting implementation.

Data sources

We searched MEDLINE and EMBASE databases from January 2002 to June 2024, the grey literature and undertook backward and forward citation searches of included studies without geographical restrictions.

Study selection

Eligible study types included non-randomised trials, interrupted time series, before–after studies, economic simulations and mixed-methods studies. Case studies providing outcome data linked to specific interventions were also included. Studies were screened by multiple reviewers for eligibility.

Data extraction

Data was extracted on geographical location and dates of interventions, descriptions of the interventions, contexts and outcome data relevant to review objectives which were checked by a second reviewer. Quality assessment was conducted using the Joanna Briggs Institute (JBI) critical appraisal tools appropriate for each study design.

Data synthesis

Five studies and 16 case studies were included. These reported on a range of interventions (including track-and-trace systems, anti-counterfeit measures and communications campaigns) and outcomes (including tax revenue and population attitudes toward IT). There was some evidence for the effectiveness of track-and-trace systems. Case studies, predominantly on national-level interventions, reported decreases in IT market share and increases in tax revenue suggesting potential benefits of multicomponent strategies.

Conclusions

There is promising limited evidence for interventions to tackle IT but they are seldom systematically evaluated. Comprehensive, independent evaluations are required to support policymaking and avoid tobacco industry influence in IT research.

PROSPERO registration number

CRD42023452732.
Rotational dynamics of a disk in a thin film of weakly nematic fluid subject to linear friction
Authors: Daddi-Moussa-Ider Abdallah , Tjhung Elsen , Pradas Marc , Richter Thomas , Menzel Andreas M.
Published: September 2024

Dynamics at low Reynolds numbers experiences recent revival in the fields of biophysics and active matter. While in bulk isotropic fluids it is exhaustively studied, this is less so in anisotropic fluids and in confined situations. Here, we combine the latter two by studying the rotation of a disk-like inclusion in a uniaxially anisotropic, globally oriented, incompressible two-dimensional fluid film. In terms of a perturbative expansion in parameters that quantify anisotropies in viscosity and in additional linear friction with a supporting substrate or other type of confinement, we derive analytical expressions for the resulting hydrodynamic flow and pressure fields as well as for the resistance and mobility coefficients of the rotating disk. It turns out that, in contrast to translational motion, the solutions remain well-behaved also in the absence of the additional linear friction. Comparison with results from finite-element simulations shows very good agreement with those from our analytical calculations. Besides applications to describe technological systems, for instance, in the area of microfluidics and thin cells of aligned nematic liquid crystals, our solutions are important for quantitative theoretical approaches to fluid membranes and thin films in general featuring a preferred direction.
AMP: A Method for Estimating the Temperature of the Processor Based on SNN
Authors: Xiong Hai , Shen Yuhao , Cheng Long
Published: September 2024

The demand for multicore processors has significantly increased with the rapid advancement in technology. Effective thermal managements for multicore processors are crucial for extending their operational lifespan. This paper estimates the core temperature of multi-core processors based on the membrane potential of the spiking neural network (SNN). This research collects hardware information of multi-core processors on real machines and estimates the temperature of the processor based on spiking neural network. We use proxy gradients to implement network updates and propose an AMP method to represent temperature. Experimental results reveal that the MAPE between estimated and actual processor temperatures averages almost around 7%, demonstrating the method’s high generalizability across various continuous value regression problems. In addition, the code for collecting the dataset used in this paper will be publicly available.
Nonrigidly rotating stationary cylindrical dust spacetimes
Authors: Chan R. , Santos N. O.
Published: September 2024

In this paper, we consider stationary rotating cylindrically symmetric dust spacetimes. We first show that the Maitra spacetime is the unique nonrigidly (nonnull shear scalar) rotating solution with a regular axis and that is the most general one of the field equations. We are also able to demonstrate what Maitra’s paper does not show, where the solution is merely stated without any demonstration. Then we find that the nonrigidly rotating spacetimes, not necessarily regular, can be matched, across timelike cylindrical hypersurfaces, to a one-parameter family of stationary vacuum exteriors given by the Weyl class but not to the Lewis class, generalizing a result by Bonnor and Steidman. Among other properties, it is shown that the amount of rotating dust packed inside a cylinder is bigger if it is rigidly rotating than nonrigidly rotating. Finally, we show that in the nonrigidly rotating cases the fluid necessarily has vorticity and the spacetimes are not silent, where the magnetic part of the Weyl tensor is nonzero.
Effective potential approach to study hydrodynamics and particle dynamics in Kerr geometry
Authors: Bhattacharjee Abhrajit , Chakrabarti Sandip K.
Published: September 2024

In this paper, we derive the exact form of effective potential in Kerr geometry from the general relativistic radial momentum equation. The effective potential accurately mimics the general relativistic features, over the entire range of the spin parameter [Formula: see text]. We obtain the exact expression of the rate of dragging of inertial frames that can be used to study the relativistic precession of twisted accretion disks that are formed when the disk outskirts are tilted relative to the equatorial plane of the black hole. We then present an effective potential that provides a simplistic approach to study particle dynamics using physical concepts analogous to the Newtonian physics. We compare the equatorial as well as off-equatorial particle trajectories obtained using our potential with the general relativistic solutions. We find that our approach can capture the salient features of Kerr geometry and is applicable to studies of accretion processes around Kerr black holes.
Gödel-type spacetimes in f(Q) gravity
Authors: Silva A. M. , Rebouças M. J. , Lemos N. A.
Published: September 2024

There is ongoing interest in the nonmetricity formulation of gravity. The nonlinear extension of the theory, called [Formula: see text] gravity, has recently been proposed and offers a promising avenue for addressing some of the long-standing challenges in cosmology and fundamental physics. A number of solutions have already been found that have confirmed the usefulness of the theory for astrophysics and cosmology. Motivated by earlier work on Gödel-type spacetimes, we investigate whether [Formula: see text] gravity admits such cosmological solutions, which entail causality violation. In the coincident gauge, which is shown to be a legitimate gauge because the connection field equations are satisfied, we find that Gödel-type metrics are allowed by this modified gravity theory for any function [Formula: see text]. Noncausal and causal solutions exist depending on the matter content. For a perfect fluid, out of all Gödel-type metrics only Gödel’s original model is allowed in [Formula: see text] gravity, implying violation of causality. The requirement that energy conditions be obeyed by the fluid leads to mild restrictions on [Formula: see text]. For a massless scalar field in the presence of a cosmological constant, there are causal solutions for any reasonable function [Formula: see text].
EXPERIMENTAL STUDY ON FABRICATION OF Al ALLOY Al6061 MICROCHANNEL USING WIRE ELECTRICAL DISCHARGE MACHINING (WEDM)
Authors: ANSARI MAHAMOOD , KHAN IMTIAZ ALI , ARIF UMAIR
Published: September 2024

This study investigates the optimization of wire electrical discharge machining (WEDM) parameters for microchannel machining of aluminum alloy Al 6061 with improved mechanical properties, which is crucial for various industries. This investigation for microchannel fabrication considers four response parameters: material removal rate (MRR), surface roughness (SR), tool wear rate (TWR), and spark gap (SG), alongside four input parameters: pulse on time (Ton), sparking gap voltage (SGV), wire tension (WT), and wire feed rate (WFR). The selected levels for the experiment are, Ton 105, 115, and 125[Formula: see text][Formula: see text]s, SGV 10, 25, and 40 volts, WT 6, 8, and 12[Formula: see text]kgf, and the WFR 2, 4, and 6[Formula: see text]m/min. By examining Ton, SGV, WT, and WFR, the research identifies optimal conditions using Taguchi-based grey relational analysis (GRA). The findings highlight the importance of parameters such as Ton of 105[Formula: see text][Formula: see text]s, SGV of 40 volts, WT of 8[Formula: see text]kgf, and WFR of 4[Formula: see text]m/min for machining Al 6061-based microchannels, offering valuable insights for future manufacturing endeavors. This research also incorporates the morphology study of machined Aluminium alloy microchannel.
Ultrafast saturable to reverse saturable absorption transition in CoTCPP SURMOF nanofilms and its application to all-optical logic and encryption
Authors: Saifi Anam , Roy Sukhdev
Published: September 2024

A detailed theoretical analysis of ultrafast intensity-dependent Saturable Absorption (SA) to Reverse Saturable Absorption (RSA) transition in CoTCPP SURMOF nanofilms has been presented with femtosecond (fs) laser pulses at 400[Formula: see text]nm. The effect of input pulse intensity, sample thickness, concentration, and 3[Formula: see text] and 5[Formula: see text] order nonlinear absorption (NLA) coefficients on transmittance has been studied in detail and optimized for high contrast and low-power operation. The maximum modulation achieved for RSA is 55% at 62[Formula: see text]GW/cm2. The results have been used to design all-optical fs-NOT, AND, OR, XOR and the universal NOR and NAND logic gates with 400[Formula: see text]nm thick CoTCPP SURMOF nanofilms. The modulation achieved for all-optical universal NAND logic gate is 45% at [Formula: see text][Formula: see text]GW/cm2. All-optical encryption and decryption for information security has been demonstrated based on all-optical XOR logic gates which offers high bit rate of 9[Formula: see text]Tbits/s at [Formula: see text][Formula: see text]GW/cm2 for secure data transmission without any optoelectronic conversion delays. An all-optical passive diode has also been theoretically designed with 17[Formula: see text]dB nonreciprocity. Ultrafast operation at relatively low input intensities opens up interesting prospects for the applicability of CoTCPP SURMOF nanofilms for ultrafast all-optical computing and information processing.
On the S-Krull dimension of a commutative ring
Authors: Kim Hwankoo , Mahdou Najib , Oubouhou El Houssaine
Published: September 2024

We explore the concept of the [Formula: see text]-Krull dimension in commutative rings, extending classical notions of Krull dimension by incorporating multiplicative subsets [Formula: see text] of a ring [Formula: see text]. We provide characterizations of [Formula: see text]-prime, [Formula: see text]-maximal, and [Formula: see text]-minimal [Formula: see text]-prime ideals, establishing foundational results crucial for understanding the [Formula: see text]-Krull dimension. The paper also delves into properties of [Formula: see text]-principal ideal [Formula: see text]-domains, [Formula: see text]-Artinian rings, and u-[Formula: see text]-von Neumann regular rings, introducing an [Formula: see text]-variant of the Division Algorithm. In the final section, the concept of [Formula: see text]-height for [Formula: see text]-prime ideals is defined, and the [Formula: see text]-Krull dimension is analyzed through various characterizations and examples, with a particular focus on polynomial rings. We conclude with insights into the [Formula: see text]-height of larger [Formula: see text]-prime ideals of [Formula: see text] and their intersections with [Formula: see text], contributing to a deeper understanding of the [Formula: see text]-Krull dimension.
Application of Fuzzy Reasoning with Fusion Rules in Intelligent Information Processing
Authors: Zhang Honglan
Published: September 2024

The core of artificial intelligence (AI) research is intelligent information processing, and fuzzy reasoning and fuzzy neural networks are significant research areas in models of intelligent information processing. The study examines the robustness of fuzzy reasoning by using the property characteristics of triangular modal operators and implication operators, which are used to analyse the Lipschitz property of fuzzy operators and its corresponding property characteristics of triangular modal operators and implication operators. Inference operators are used to investigate the robustness and error-control capabilities of fuzzy operators for fuzzy reasoning. The results showed that the robustness of quasi-copula fuzzy reasoning with fusion rules is better, and the corresponding maximum output perturbation is lowest at 0.36 when the fuzzy operator is TM&RMTc and the corresponding maximum output error is lowest at 0.41 when the fuzzy operators are TM&RMKl and TM&RMa. This shows the optimal performance of the fuzzy associative memory model with fuzzy rule for quasi-copula fuzzy operators and can improve the theoretical technology. The best-performance fuzzy copula operator of the fuzzy associative memory model can enhance the theoretical foundation and technical support for the processing of intelligent information.
Two new kinds of orthomodular lattices: Nilpotent and Engel orthomodular lattices
Authors: Najafi Ardavan
Published: September 2024

In this paper, the concepts of nilpotent and Engel orthomodular lattices, similar with the solvable orthomodular lattices are defined and their properties are investigated. The notion of [Formula: see text]-Engel orthomodular lattices as a natural generalization of distributive orthomodular lattices is introduced, and we discuss Engel orthomodular lattices, which is defined by left and right normed commutators.
Fingerprinting Magnetic States in Interconnected Nanoring Arrays via Spin Wave Spectra
Authors: Swindells C. , Eade D. R. , Silsupadol T. , Hayward T. J.
Published: September 2024

Arrays of interconnected magnetic nanorings show emergent dynamics arising from stochastic interactions at junctions between rings. These global emergent properties have already shown potential as a platform for reservoir computing. However, their experimental computational performance has been limited by the use of a single-dimensional global measurement, their magnetoresistance, as an output, masking much of the underlying state information. Here, we show in both simulation and experiment the potential of using the spin wave spectra of such arrays of nanorings to produce a fingerprint of the number and orientation of the internal magnetic states, providing a route towards a multi-dimensional output with which to perform computation. We show that the spectra fulfill the two criteria for reservoir computing: a nonlinear response to an input stimulus, and a fading memory.
Decolonizing AI: Implementing Humanitarian Artificial Intelligence
Authors: Sapién Abraham , Gamba Jorge Oseguera
Published: September 2024

In this article, we critically examine the implementation of what Carlos Montemayor calls Humanitarian Artificial Intelligence from a decolonizing perspective. We highlight the dichotomy of optimism and fear surrounding AI, elucidating its potential to address fundamental human problems and the risks of monopolistic control. We critique Montemayor’s proposal to align AI with a human rights framework, arguing that it insufficiently addresses global inequalities. Our tripartite analysis focuses on the distribution of AI resources, language inclusion, and content diversity to ensure AI benefits all humanity. We emphasize the need for equitable access to AI, linguistic diversity in AI training data, and the preservation of marginalized epistemologies. We advocate for strategies to mitigate environmental impacts and avoid cultural imperialism disguised as altruism, calling for a balanced approach between private sector innovation and state regulation to foster a truly humanitarian AI.
Neural Architecture Search as Program Transformation Exploration
Authors: Turner Jack , Crowley Elliot J. , O'Boyle Michael F.P.
Published: September 2024

Improving the performance of deep neural networks (DNNs) is important to both the compiler and neural architecture search (NAS) communities. Compilers apply program transformations in order to exploit hardware parallelism and memory hierarchy. However, legality concerns mean they fail to exploit the natural robustness of neural networks. In contrast, NAS techniques mutate networks by operations such as the grouping or bottlenecking of convolutions, exploiting the resilience of DNNs. In this work, we express such neural architecture operations as program transformations whose legality depends on a notion of representational capacity. This allows them to be combined with existing transformations into a unified optimization framework. This unification allows us to express existing NAS operations as combinations of simpler transformations. Crucially, it allows us to generate and explore new tensor convolutions. We prototyped the combined framework in TVM and were able to significantly reduce inference time and NAS search time.
Elevating Security with Arm CCA
Authors: Garcia-Tobin Charles , Knight Mark
Published: September 2024

Attestation and verification are integral to adopting confidential computing.
A Portable Linux-based Firmware for NVMe Computational Storage Devices
Authors: Wertenbroek Rick , Thoma Yann , Dassatti Alberto
Published: September 2024

Over the years, interest in computational storage devices has been growing steadily. This is largely due to the rise of data-intensive applications, such as machine learning, online video distribution, astrophysics, and genomics. Moving compute operations closer to the data provides benefits in terms of scaling possibilities and energy efficiency. The development of computational storage devices has been limited by the need for specialized and complex hardware. In this work, we propose a portable Linux-based firmware framework for the development of NVMe computational storage devices. Our firmware runs on a variety of hardware platforms ranging from expensive FPGA solutions to inexpensive off-the-shelf single board computers. The firmware leverages the vast Linux software ecosystem to facilitate the development and prototyping of novel computational storage devices. We benchmark our firmware on multiple hardware platforms and demonstrate its versatility through several computational examples including a content-aware disk image search engine based on natural language processing and AI-driven image recognition.
Method—Best Practices and Common Pitfalls in Experimental Investigation of Electrochemical CO2 Reduction at Gas Diffusion Electrodes
Authors: Osiewacz Jens , Ellendorff Barbara , Kunz Ulrich , Turek Thomas
Published: September 2024

Gas diffusion electrodes (GDEs) play a crucial role in the development of electrochemical CO2 reduction (eCO2R) toward an economically viable process. While membrane electrode assemblies (MEAs) are currently the most efficient approach due to their low cell voltage, electrolyte supported GDEs still present a valuable tool for the characterization of catalysts under industrially relevant current densities, allowing for direct measurement of the electrode potential against reference electrodes. In this study, common experimental methods of iR correction and pressure control in eCO2R literature studies on GDEs are analyzed and compared regarding their potential impact on the reported results. It is revealed that failure to account for dynamic changes in iR-drop can lead to significant inaccuracies in reported electrode potentials. Additionally, common methods for the application of differential pressure across GDEs are shown to impact the performance, leading to additional errors in experimental results. Based on these findings, an experimental protocol for the application of single high frequency response as a method for iR correction is developed, providing a tool for reproducible electrochemical characterization of GDEs in eCO2R.
Inference of alveolar capillary network connectivity from blood flow dynamics
Authors: Schmid Kerstin , Olivares Andy L. , Camara Oscar , Kuebler Wolfgang M. , Ochs Matthias , Hocke Andreas C. , Fischer Sabine C.
Published: September 2024

The alveolus is pivotal for gas exchange. Its complex, dynamic nature makes structural experimental studies challenging. Computational modeling offers an alternative. We developed a data-based three-dimensional (3-D) model of the alveolar capillary network and performed blood flow simulations within it. Choosing a novel perspective, we inferred structure from function. We systematically varied the properties of vessels connected to our capillary network and analyzed simulation results for blood flow and gas exchange to obtain plausible vessel configurations.
Disruption of immune responses by type 1 diabetes exacerbates SARS-CoV-2 mediated lung injury
Authors: Kass-Gergi Sara , Zhao Gan , Wong Joanna , Weiner Aaron I. , Adams Tzivelekidis Stephanie , Gentile Maria E. , Mendoza Meryl , Holcomb Nicolas P. , Li Xinyuan , Singh Madeline , Huang Yuru , Klochkova Alena , Vaughan Andrew E.
Published: September 2024

We define the exacerbating effects of type 1 diabetes mellitus (T1DM) on COVID-19 pneumonia severity in mice. Hyperglycemic mice experienced increased weight loss and reduced oxygen saturation. Transcriptomic analysis revealed impaired immune responses in diabetic mice, while flow cytometry and single-cell RNA sequencing confirmed reduced T-cell recruitment and an inflammatory macrophage profile. In addition, we introduced a novel technique for tissue analysis, enabling flow cytometric analysis on highly fixed tissue samples.
Physical effort precrastination determines preference in an isometric task
Authors: Healy Chadwick M. , Ahmed Alaa A.
Published: September 2024

We use a novel paradigm that differentiates physical effort costs, task costs, and time, where subjects choose between isometric arm-pushing tasks. Subjects prefer high physical effort earlier than later. They also decide faster and respond more vigorously the greater their preference. We find a generalizable subjective utility model that includes independent time-sensitivity of physical effort and task costs. Together, we demonstrate that subjective effort includes not only the total effort invested but also its timing.