bluuebunny/crossref_metadata_2025 huggingface dataset:
Model predictive control for space robot manipulator modeled by switched systems: A data‐driven approach
Authors: Chen Qixin , Zhu Yanzheng , Zhang Jian
Published: October 2024

This article investigates the data‐driven based model predictive control (MPC) problem for a class of space robot manipulator (SRM). First, the SRM system is modeled as a class of discrete‐time switched system to reflect more system characteristics. Second, only the input‐state data are used for end‐to‐end controller design, and the system identification process is avoided. In order to meet the real‐time requirements of the manipulator arm angles, a kind of constrained predictive control method is designed to prevent the overheating or damage of SRM motor, optimizing the cost function for each decision cycle under the safe control input constraints. Then, based on the average dwell time method, the asymptotic stability is assured for the presented SRM system. The design conditions for data‐driven based MPC are provided in the form of linear matrix inequalities. Finally, the effectiveness and advantage for the developed data‐driven based MPC strategy are validated via a case study of SRM system.
Bolster Sustainability Through Asset Management
Authors: Zach Tacoma , Zach Jennifer
Published: October 2024

Today, more organizations recognize that sustainability is at the heart of value creation; it's not just about being good stewards of our resources. A water utility contributes to sustainability—for itself and the environment—if it wisely manages its assets through sound financial decisions, regular maintenance, and resilience planning.
Coliform Tests: An Evolution Serving Public Health
Authors: Pizzi Nick , Roland Mary
Published: October 2024

It's difficult and expensive to routinely examine waters for the presence of every type of pathogen. It's more practical to screen water for the presence of fecal contamination by testing for the presence of an “indicator” microorganism.
Operators Need to Know Wastewater Treatment Processes
Authors: Ash Steve , Adams Hunter , Southard Mark , Blake Susie , Thomas Dave , Fischer James , Chitikela S. Rao , Ikehata Keisuke
Published: October 2024

Understanding wastewater treatment processes is key to ensuring finished quality for discharge into the environment.
When Partial Lead Service Line Replacements Can’t Be Avoided
Authors: Locsin Javier A. , Kutzing Sandra
Published: October 2024

Because partial lead service line replacements don’t reliably reduce and can even increase lead levels, full replacement is the best option. However, when partial replacement can’t be avoided, steps can be taken to ensure it's done responsibly.
Amphiphilic block‐copolymer exfoliated transition metal dichalcogenides as novel epoxy toughening agents
Authors: Venu Gopika , Jayan Jitha S. , Krishnapriya R. C. , Saritha Appukuttan
Published: October 2024

Excited by the effect of amphiphilic block copolymer Polyethylene glycol‐b‐Polypropylene Glycol‐b‐Polyethylene Glycol, a triblock copolymer (TBCP) in the virgin state as well as in the grafted form with graphene oxide and multiwalled carbon nanotube in epoxy toughening, the effect of the same block copolymer in the exfoliation of graphene analogous Transition Metal Dichalcogenides (TMDs) was studied. Even though epoxy resin has several advantages, its inherent brittleness and flammability limit its application in several areas. So, there is a need for the efficient toughening of epoxy resin to make it appropriate for high‐end applications. In the present work, epoxy resin was toughened with exfoliated TMDs, especially Molybdenum sulfide and Tungsten disulfide (MoS2 and WS2). TBCP was used in the exfoliation of TMDs where the effect of these exfoliated TMDs in enhancing the properties of epoxy was evaluated. TBCP exfoliated MoS2 and WS2 exhibit fracture toughness of 483% and 636%, respectively in epoxy composites without compromising the tensile properties, which enhances the efficacy of epoxy resins towards high‐end applications. The improvement in toughness is evident from the fractography of the crack surfaces. The role of TBCP exfoliated TMDs in tuning the mechanical, thermal, and thermomechanical properties is portrayed in the manuscript, thereby unveiling the potential of yet another unique class of materials in epoxy toughening.

Highlights

The efficiency of amphiphilic block copolymer in exfoliating TMDs is analyzed.

The effect of TBCP‐exfoliated TMDs as a toughener for the epoxy matrix is portrayed.

483% and 636% improvement in the toughness compared to neat epoxy was obtained for TBCP exfoliated MoS2 and WS2 reinforced epoxy respectively.

Improved tensile properties after incorporation of TBCP exfoliated TMDs in epoxy matrix.

The plasticizing effect of TBCP compromises the thermal properties.
Association Between Oral Fluoroquinolones and Neuropsychiatric Events: Self‐Controlled Case Series With Active Comparator Design
Authors: Zhang Yin , Fan Min , Tsie Natalie T. Y. , Lee Edwin H. M. , Chang W. C. , Chen Eric Y. H. , Chan Esther W. , Wong Ian C. K. , Chui Celine S. L. , Wong Angel Y. S.
Published: October 2024

Purpose

The evidence of the neuropsychiatric effects associated with fluoroquinolones is mainly supported by case reports. Population‐based evidence remains largely limited. We aimed to investigate the association between the use of fluoroquinolones and hospitalization or Accident & Emergency department visits for acute neuropsychiatric events using a self‐controlled case series (SCCS) and active comparator to reduce confounding.

Methods

We conducted a SCCS with a recently described active comparator design using all public outpatient clinics, hospitalization, and Accident and Emergency department records from the Clinical Data Analysis and Reporting System, Hong Kong from 2001 to 2013. Among 166 325 people with an oral fluoroquinolone prescription, 4287 people who had an incident neuropsychiatric event were included. We then estimated the incidence rate ratio (IRR) of acute neuropsychiatric events during periods before and after fluoroquinolone prescription, versus baseline. We repeated the analysis for amoxicillin/clavulanic acid users as an active comparator. We then estimated the comparator‐adjusted estimates by dividing the IRR for fluoroquinolone by the IRR for amoxicillin/clavulanic acid. The primary outcome was neuropsychiatric events. Secondary outcomes were psychotic events and cognitive impairment.

Results

An increased risk of neuropsychiatric events was observed in the current use of fluoroquinolone [IRR: 2.11 (95% confidence interval (CI): 1.58–2.83)] and 1–7 days after the end of fluoroquinolone prescription [IRR: 1.90 (95% CI: 1.30–2.75)] versus baseline. No increased risk was observed in other risk periods versus baseline. Similar patterns were observed in the current use of amoxicillin/clavulanic acid [IRR: 1.92 (95% CI: 1.19–3.11)] and 1–7 days after the end of fluoroquinolone prescription [IRR: 1.81 (95% CI: 1.11–2.97)] versus baseline. Similar results were found for secondary outcomes. Using the active comparator design, comparator‐adjusted estimates were 1.10 (95% CI: 0.63–1.93) in current use of fluoroquinolones and 1.05 (95% CI: 0.57–1.95) in 1–7 days postexposure to fluoroquinolones versus baseline.

Conclusions

Although our study showed a higher incidence of neuropsychiatric events in the current use of fluoroquinolones and 7 days after the end of fluoroquinolones prescriptions compared with baseline, a similar temporal pattern was also found for amoxicillin/clavulanic acid users. Using amoxicillin/clavulanic acid as the active comparator, we found no difference in the risk of neuropsychiatric events associated with fluoroquinolone compared with baseline. Therefore, the risk of neuropsychiatric events may not need to influence the decision to prescribe either fluoroquinolones or amoxicillin/clavulanic acid based on the evidence in this study.
Diversity and distribution of Mdace mutations involved in propoxur resistance in the house fly (Musca domestica L.) in China
Authors: You Chunmei , Zhang Lulu , Song Jiajia , Zhen Congai , Ji Xiangyun , Zhang Lei , Gao Xiwu
Published: October 2024

BACKGROUND

The house fly is a public health pest due to its ability to transmit various pathogens worldwide. The suppression of house flies is frequently controlled by organophosphate and carbamate insecticides, but recurrent selection has led to the mutated target. To understand the spread and evolution of Mdace mutations in house flies, we sampled flies in eight different China provinces, sequenced, and then estimated the frequencies of mutations.

RESULTS

The inhibition of AChE towards propoxur varied geographically and was lowest in the Heilongjiang field population, and highest in Jiangsu population. The overall frequencies of the different Mdace mutations (V260L, G342A, G342V, F407Y) varied considerably between populations. Strong positive correlations were found between acetylcholinesterase (AChE) insensitivity and the frequencies of G342V allele, 342A/V genotype and combination (260V/L‐342A/V‐407Y/Y) for the field populations. Eighteen combinations of Mdace at three sites (V260L, G342A/V, F407Y) were observed, with the majority of flies being categorized into the combination (260V/L‐342A/V‐407Y/Y), ranging in frequency from 24% (in field populations in Hubei and Hainan) to 96% (Jiangsu).

CONCLUSION

Based on comparison with historical data, the mutations responsible for the extremely high resistance to the level of insecticide resistance spread widely, propoxur should be limited to use for house fly control in China. © 2024 Society of Chemical Industry.
Hybrid Optimization Approach Using Multiobjective Genetic Algorithm NSGA‐II, SCAPS‐1D Simulation, and Response Surface Methodology for Organic Solar Cell Analysis
Authors: Moulebhar Samia , Bendenia Chahrazed , Merad‐Dib Hanaa , Bendenia Souhila , Merabet Sarra , Khantar Sid Ahmed
Published: October 2024

In the field of simulation, it is difficult to find the relevant values for the properties of materials and in this context this approach has been proposed on optimizing the performance of organic solar cells, a promising technology in the field of renewable energy, to increase their efficiency. It adopts a hybrid approach combining the response surface methodology (RSM) with a Box–Behnken design (BBD) and the nondominated sorting genetic algorithm II (NSGA‐II). The RSM BBD method is used to identify objective functions to be optimized, considering interactions between selected parameters such as the thickness of the active layer, electron‐transport layer (ETL), hole‐transport layer (HTL), and the doping of these layers. Concurrently, the NSGA‐II genetic algorithm aims to maximize the performance of the solar cell based on these parameters. The specific importance of NSGA‐II lies in its ability to solve complex multiobjective optimization problems. Indeed, NSGA‐II is designed to simultaneously manage several performance objectives, which is crucial for organic solar cells. Its ability to generate a diverse set of optimal solutions enables efficient configurations to be found that may not be obvious with simpler optimization approaches. The results of this study show that optimum solar cell performance is achieved with active layer, ETL layer, and HTL layer thicknesses of 100.86, 79.9, and 20.24 nm, respectively, and active layer doping of 8.71E + 21 cm−3, HTL layer doping of 9.90E + 21 cm−3, and ETL layer doping of 9.49E + 21 cm−3. Analysis using Solar Cell Capacitance Simulator‐1D (SCAPS‐1D) software shows that optimum performance is achieved with these specific parameter values. After optimization with NSGA‐II, the power conversion efficiency increases by 39% compared to previous work. This study provides evidence of the effectiveness of the proposed hybrid approach for optimizing the performance of organic solar cells. By showing remarkable agreement between the results obtained by NSGA‐II and SCAPS‐1D, this approach opens up promising prospects for the future of renewable energy.
Model Reference‐Based Neural Controller for Transmission Line Inspection Robot
Authors: Karagöz Zehra , Ekren Nazmi , Demir Uğur , Baba Ahmet Fevzi , Şahin Mustafa
Published: October 2024

The regular inspection of the power transmission lines is essential for the uninterrupted transmission of electrical energy to demand points. This quickly requires actions with economically, efficiently, and safely. Therefore, the transmission line inspection robots are inevitable solution as an alternative to existing line inspection methods. This study present design and control of a transmission line inspection robot (I‐Robot). Since the I‐Robot exhibits nonlinear behavior and has multiple inputs and multiple outputs, a model reference‐based neural controller is determined to achieve nonlinear control. The robot design process consists of four stages which are kinematic modelling, dynamic modelling, actuator modelling and controller design. To meet inspection requirements, the conceptual design of the I‐Robot is performed, and the kinematic model are calculated in terms of the transformation matrices. According to the design requirements and system constraints, the dynamic model of the I‐Robot is created. To provide desired motions and trajectory tracking, the actuator models are determined. Then, the I‐Robot is prototyped. According to the dynamics of joint, robot and constraints, the system identification is performed to create reference model. During the system identification, the logged data are used the train the reference model. Finally, the desired trajectory for the driving cycles is created by manual excitation of the I‐Robot. During the manual excitation, the logged data are used to train the neural network (NN)‐based controller. Eventually, the I‐Robot is assessed under the test scenarios in term of the trajectory tracking performance as regression value and mean squared errors. According to the experiments, the neuron numbers and the training algorithm of the NN controller are determined. It was observed that the controller is quickly optimized with the adapting algorithm designed for the NN reference model. As a result, the performance of the model reference‐based neural controller was determined as 99%.
Causal Inference for Continuous Multiple Time Point Interventions
Authors: Schomaker Michael , McIlleron Helen , Denti Paolo , Díaz Iván
Published: October 2024

There are limited options to estimate the treatment effects of variables which are continuous and measured at multiple time points, particularly if the true dose–response curve should be estimated as closely as possible. However, these situations may be of relevance: in pharmacology, one may be interested in how outcomes of people living with—and treated for—HIV, such as viral failure, would vary for time‐varying interventions such as different drug concentration trajectories. A challenge for doing causal inference with continuous interventions is that the positivity assumption is typically violated. To address positivity violations, we develop projection functions, which reweigh and redefine the estimand of interest based on functions of the conditional support for the respective interventions. With these functions, we obtain the desired dose–response curve in areas of enough support, and otherwise a meaningful estimand that does not require the positivity assumption. We develop ‐computation type plug‐in estimators for this case. Those are contrasted with g‐computation estimators which are applied to continuous interventions without specifically addressing positivity violations, which we propose to be presented with diagnostics. The ideas are illustrated with longitudinal data from HIV positive children treated with an efavirenz‐based regimen as part of the CHAPAS‐3 trial, which enrolled children years in Zambia/Uganda. Simulations show in which situations a standard g‐computation approach is appropriate, and in which it leads to bias and how the proposed weighted estimation approach then recovers the alternative estimand of interest.
Facile Design of Bi2S3‐Doped CeO2/Dihydroxybenzoate Composite as Highly Efficient UV‐Shielding Agents
Authors: Ma Xiangmei , Pan Shengmin , Wu Yiqing , Wang Bin
Published: October 2024

In this study, bismuth sulfide (Bi2S3)‐doped cerium oxide (CeO2) was prepared via hydrothermal method, and by depositing ethyl 3,4‐dihydroxybenzoate (EDHB) on the surface of Bi2S3/CeO2 (Bi2S3/CeO2/EDHB and BCE). The samples were characterized by FTIR, XRD, TEM, and UV–vis absorption spectrum means. According to the characterizations, Bi2S3 was successfully incorporated into the CeO2 structure (Bi2S3/CeO2), and the prepared BCE/PVC composite films display excellent UV‐shielding property. Moreover, the result of thermogravimetric analysis (TGA) tests indicated that BCE also was barely catalytic thermal decomposition of PVC matrix. This work not only paves an attractive way for the design of the CeO2‐based UV‐shielding agent, but also provides valuable insights into the inspiration to construct high‐performance UV‐shielding composites.
Deciphering the Electronic Coupling Dynamics of Laser‐induced Ru/Cu Electrocatalyst for Dual‐Side Hydrogen Production and Formic Acid Co‐synthesis via DFT Analysis
Authors: Sarsenov Sagyntay , Senthil Raja Arumugam , Min Ahreum , Kumar Anuj , Moon Cheol Joo , Park Juhyeon , Choi Myong Yong
Published: October 2024

Herein, a straightforward approach using pulsed laser technology to synthesize selective hexagonal‐close‐packed (hcp) Ru nanoparticles attached to Cu nanospheres (Ru/Cu) as bifunctional electrocatalyst for catalyzing the hydrogen evolution reaction (HER) and formaldehyde oxidation reaction (FOR) are reported. Initially, Ru‐doped CuO flakes are synthesized using a coprecipitation method followed by transformation into Ru/Cu composites through a strategy involving pulsed laser irradiation in liquid. Specifically, the optimized Ru/Cu‐4 composite not only demonstrates a low overpotential of 182 mV at 10 mA·cm−2 for the HER but also an ultralow working potential of 0.078 V (versus reversible hydrogen electrode) for the FOR at the same current density. Remarkably, the FOR∥HER‐coupled electrolyzer employing the Ru/Cu‐4∥Ru/Cu‐4 system achieves H2 production at both electrodes with a cell voltage of 0.42 V at 10 mA·cm−2 while co‐synthesizing formic acid. Furthermore, density functional theory analyses elucidate that the superior activity of the Ru/Cu composite originates from optimized adsorption energies of reactive species on the catalyst surfaces during the HER and FOR, facilitated by the synergistic coupling between Ru and Cu. This study presents an alternative strategy for synthesizing highly effective electrocatalytic materials for use in energy‐efficient H2 production with the cosynthesis of value‐added chemicals suitable for practical applications.
Intrinsic charge manipulation for solution‐processed organic photodetectors with high sensitivity and fast response
Authors: Yang Tingbin , Yan Jun , Gong Li , Zhong Wentao , Chen Bulin , Shen Liang , Pan Jisheng , Nelson Jenny , Liang Yongye
Published: October 2024

Charge manipulation is crucial in optoelectronic devices. The unoptimized interfacial charge injection/extraction in solution‐processed bulk‐heterojunction (BHJ) organic photodetectors (OPDs) presents significant challenges in achieving high detectivity and fast response speed. Here, we first develop an approach for intrinsic charge manipulation induced by molecularly engineered donors to block electron injection and facilitate hole extraction between the indium tin oxide (ITO) transparent anode and the photoactive layer. By utilizing a polymer donor with 3,4‐ethylenedioxythiophene (EDOT) as the conjugated side chain, a polymer‐rich layer forms spontaneously on the ITO substrate due to the increased oxygen interactions between ITO and EDOT. This results in electron‐blocking‐layer (EBL)‐free devices with lower dark current and noise without a reduction in responsivity compared to control devices. As a result, the EBL‐free devices exhibit a peak specific detectivity of 2.36 × 1013 Jones at 950 nm and achieve a −3 dB bandwidth of 30 MHz under −1 V. Enhanced stability is also observed compared to the devices with poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). This work demonstrates a new method to intrinsically manipulate charge injection in BHJ photoactive layers, enabling the fabrication of solution‐processed EBL‐free OPDs with high sensitivity, rapid response, and good stability.
Artificial intelligence: Tool or teammate?
Authors: Díaz Brayan , Delgado Cesar
Published: October 2024

Artificial intelligence (AI) technologies generate increasingly sophisticated non‐human cognition; however, foundational learning theories only contemplate human cognition, and current research conceptualizes AI as a pedagogical tool. We argue that the incipient abilities of AI for mutual engagement with people could allow AI to participate as a legitimate member in social constructivist learning environments and suggest some potential structures and activities to explore AI's capabilities for full participation.
Evaluation of Intervertebral Disc Space Width Between 10th and 11th Thoracic Vertebrae in Cats Using Radiography and Magnetic Resonance Imaging
Authors: Kim Jiwon , Kwon Danbee , Kim Bumseok , Lee Kichang , Yoon Hakyoung
Published: October 2024

Background

It is well known that the T10–T11 intervertebral disc space is usually narrower than the adjacent intervertebral disc spaces in most dogs. However, whether the T10–T11 disc space is narrower than the adjacent disc spaces is not well‐established in cats.

Objectives

To measure the intervertebral disc space width of the T10–T11 disc space and to compare it with that of the adjacent disc spaces using radiography and magnetic resonance imaging (MRI).

Methods

In Groups 1 (101 clinically normal cats) and 2 (32 cats without spinal diseases from T8 to T13), dorsal width (DW), central width (CW) and ventral width (VW) of the T8–T13 disc spaces were measured by radiography or MRI. Significant differences of the DW, CW and VW among disc spaces measured by radiography and MRI were evaluated. Intra‐ and interobserver reliabilities were measured by intraclass correlation coefficient.

Results

In Groups 1 and 2 using radiography, the DW and CW of the T10–T11 disc space were significantly narrower than those of adjacent disc spaces (p < 0.05). The DW of the T8–T12 disc spaces was significantly narrower than that of the T12–T13 disc space in Group 1 using radiography. In Groups 1 and 2 using radiography, the CW and VW of the T8–T11 disc spaces were significantly narrower than those of the T11–T13 disc spaces. In Group 2 using MRI, the DW of the T10–T11 disc space was significantly narrower than that of the T11–T13 disc spaces. The VW of the T8–T11 disc spaces was significantly narrower than that of the T11–T13 disc spaces.

Conclusion

The T10–T11 intervertebral disc space on radiography is statistically narrower than the adjacent intervertebral disc spaces in normal cats. The cranial thoracic intervertebral disc spaces (T8–T11) are usually narrower than the caudal thoracic intervertebral disc spaces (T11–T13) on radiography and MRI.
Solvent‐Based and Matrix‐Matched Calibration Methods on Analysis of Ceftiofur Residues in Milk and Pharmaceutical Samples Using a Novel HPLC Method
Authors: Özcan Saniye , Levent Serkan , Öncü Can Nafiz
Published: October 2024

Background

The matrix effect is accepted as one of the critical factors that affect trueness, and it is especially important in the analysis of critical compounds, such as drugs, toxins and pesticides, in complex matrices. Ceftiofur (CEF) is a leading drug used in dairy industry for pulmonary infections. Because milk has a complex matrix, which is rich in fats, proteins and many other compounds, the determination of CEF in milk products deals with issues of trueness. On the other hand, pharmaceuticals also have a complex composition as they contain not only the active pharmaceutical ingredient but also many excipients, such as preservatives and pH modifiers. Due to its frequent use, its residues can be found in meat products or exist as an excreted compound in urine, milk and so on.

Objective

The aim of this study was to investigate the effect of different calibration methods on quantitative estimation of CEF in milk and pharmaceutical samples.

Methods

CEF was analysed using a new HPLC method, in which separation was achieved on a C18 bonded fused‐core silica particle column by using isocratic elution; the method was optimized by testing different chromatographic conditions and validated according to the ICH Q2(R1) and United States Pharmacopeia guidelines.

Results

Interestingly, it was found that CEF signals in milk samples were higher than the ones at the same level prepared in calibration solutions with a ratio of 11.28:1.

Conclusion

This finding reveals the necessity of matrix‐matched calibration for accurate quantitative determination of CEF in milk samples. Moreover, the milk in the market and the most used pharmaceutical formulations were analysed using the current method.
Forensic Science and How Statistics Can Help It
Authors: Xu Xiangyu , Vinci Giuseppe
Published: October 2024

The persistent issue of wrongful convictions in the United States emphasizes the need for scrutiny and improvement of the criminal justice system. While statistical methods for the evaluation of forensic evidence, including glass, fingerprints, and deoxyribonucleic acid, have significantly contributed to solving intricate crimes, there is a notable lack of national‐level standards to ensure the appropriate application of statistics in forensic investigations. We discuss the obstacles in the application of statistics in court and emphasize the importance of making statistical interpretation accessible to non‐statisticians, especially those who make decisions about potentially innocent individuals. We investigate the use and misuse of statistical methods in crime investigations, in particular the likelihood ratio approach. We further describe the use of graphical models, where hypotheses and evidence can be represented as nodes connected by arrows signifying association or causality. We emphasize the advantages of special graph structures, such as object‐oriented Bayesian networks and chain event graphs, which allow for the concurrent examination of evidence of various nature.
Integrating the full four-loop negative geometries and all-loop ladder-type negative geometries in ABJM theory
Authors: Li Zhenjie
Published: October 2024

Abstract

The decomposition of the four-point ABJM amplituhedron into negative geometries produces compact integrands of logarithmic of amplitudes such that the infrared divergence only comes from the last loop integration, from which we can compute the cusp anomalous dimension of the ABJM theory. In this note, we integrate L – 1 loop momenta of the L-loop negative geometries for all four-loop negative geometries and a special class of all-loop ladder-type negative geometries by a method based on Mellin transformation, and from these finite quantities we extract the corresponding contribution to the cusp anomalous dimension. We find that the infrared divergence of a box-type negative geometry at L = 4 is weaker than other negative geometries, then only tree-type negative geometries contribute to the cusp anomalous dimension at L = 4. For the all-loop ladder-type negative geometries, we prove and conjecture some recursive structures as integral equations in Mellin space and find that they cannot contribute zeta values like ζ3, ζ5 to the cusp anomalous dimension.
Bootstrapping conformal defect operators on a line
Authors: Dey Parijat , Ghosh Kausik
Published: October 2024

Abstract

We study a conformal field theory with cubic anisotropic symmetry in presence of a line defect. We compute the correlators of the low lying defect operators using Feynman diagrams and derive explicit expressions for the two, three and four point defect correlators at the cubic fixed point in 4 – ϵ dimensions to O(ϵ). We also compute the defect g-function for this setup and demonstrate that this is in agreement with the g-theorem, which states that the g-function is monotonic under the renormalisation group flow along the defect. Next, we focus on conformal bootstrap techniques to determine the CFT data associated with the defect operators, which is the main objective of the paper. We utilize the framework of crossing symmetric Polyakov bootstrap and compute the averaged CFT data to O(ϵ) up to a finite number of ambiguities. We comment on unmixing the CFT data for the double trace operators at O(ϵ) and use this to compute the O(ϵ2) data. Finally, we study these defect correlators non-perturbatively using numerical methods and isolate them near the free theory limit close to four dimensions.
The population-specific Thr44Met OCT3 coding variant affects metformin pharmacokinetics with subsequent effects on insulin sensitivity in C57Bl/6J mice
Authors: Wang Qian , Leask Megan P. , Lee Kate , Jaiswal Jagdish , Kallingappa Prasanna , Dissanayake Waruni , Puli’uvea Chris , O’Sullivan Conor , Watson Huti , Wilcox Phillip , Murphy Rinki , Merry Troy L. , Shepherd Peter R.
Published: October 2024

Aims/hypothesis

Metformin is an important first-line treatment for type 2 diabetes and acts by increasing the body’s ability to dispose of glucose. Metformin’s efficacy can be affected by genetic variants in the transporters that regulate its uptake into cells. The SLC22A3 gene (also known as EMT; EMTH; OCT3) codes for organic cation transporter 3 (OCT3), which is a broad-specificity cation transporter that also transports metformin. Most SLC22A3 variants reduce the rate of metformin transport but the rs8187715 variant (p.Thr44Met) is reported to increase uptake of metformin in vitro. However, the impact of this on in vivo metformin transport and efficacy is unknown. Very few carriers of this variant have been reported globally, but, notably, all were of Pacific Island descent. Therefore, this study aims to understand the prevalence of this variant in Polynesian peoples (Māori and Pacific peoples) and to understand its impact on metformin transport and efficacy in vivo.

Methods

rs8187715 was genotyped in 310 individuals with Māori and Pacific ancestry recruited in Aotearoa New Zealand. To study this variant in a physiological context, an orthologous knockin mouse model with C57BL/6J background was used. Pharmacokinetic analysis compared uptake rate of metformin into tissues. Plasma growth/differentiation factor 15 (GDF-15) was also measured as a marker of metformin efficacy. Glucose and insulin tolerance was assessed after acute or sustained metformin treatment in knockin and wild-type control mice to examine the impact of the variant on metformin’s glycaemic control.

Results

The minor allele frequency of this variant in the Māori and Pacific participants was 15.4%. There was no association of the variant with common metabolic parameters including diabetes status, BMI, blood pressure, lipids, or blood glucose and HbA1c. However, in the orthologous knockin mouse model, the rate of metformin uptake into the blood and tissues was increased. Acute metformin dosing increased insulin sensitivity in variant knockin mice but this effect was lost after longer-term metformin treatment. Metformin’s effects on GDF-15 levels were also lost in variant knockin mice with longer-term metformin treatment.

Conclusions/interpretation

These data provide evidence that the SLC22A3 rs8187715 variant accelerates metformin uptake rate in vivo. While this acutely improves insulin sensitivity, there was no increased effect of metformin with longer-term dosing. Thus, our finding of a high prevalence of this variant specifically in Māori and Pacific peoples identifies it as a potential population-specific pharmacogenetic marker with potential to guide metformin therapy in these peoples.

Graphical Abstract
Innovation in apatite Lu-Hf geochronology opens new opportunity for copper systems in southern Australia during the Nuna destruction
Authors: Yu Jie , Hand Martin , Payne Justin L. , Morrissey Laura J. , Simpson Alexander , Glorie Stijn , Chen Yan-Jing
Published: October 2024

Precambrian iron oxide copper-gold (IOCG) systems have commonly experienced multiple mineralising and tectonothermal events and identifying their timing and geodynamic framework is challenging. World-class IOCG deposits in the Olympic Cu-Au Province, South Australia, are dominated by hematite and formed in the upper crust, while the magnetite-dominated Cu deposits hosted in granulite facies rocks are considered to represent the deeper expression of giant IOCG system. However, the application of novel in-situ Lu-Hf apatite geochronology reveals the magnetite-hosted Cu mineralisation is significantly younger and unrelated to the well-known ~ 1590 Ma Gawler Craton IOCG systems. Apatite Lu-Hf ages from the granulite that predates Cu mineralisation give ages of 1490 Ma. Infiltration of Cu-bearing fluids resulted in recrystallisation of apatite, LREE mobilisation and formation of secondary monazite. Lu-Hf ages for syn-mineralisation apatite give 1460 Ma, consistent with c. 1460 Ma U-Pb ages from secondary monazite. In contrast to the apatite in situ Lu-Hf ages, all apatite types produce a single U-Pb age of c. 1460 Ma, demonstrating the ability of Lu-Hf to preserve a more complete history of apatite formation than U-Pb in high- to medium-temperature rock systems. The timing of mineralisation coincides with the onset of Nuna fragmentation, representing a previously unrecognised driver for mineral system formation in southern Australia that installed Cu in crust previously dehydrated during a long history of granulite-grade tectonic events. The recognition of this Cu system in rocks generally considered unprospective shows that continental breakup can rejuvenate metallic systems in otherwise unprospective crust.
Americans’ views of artificial intelligence: identifying and measuring aversion
Authors: Livingston Will
Published: October 2024

This study explores the phenomenon of artificial intelligence (AI) aversion within the context of public policy, building on prior research on algorithmic aversion. I aim to establish a clear conceptual distinction between algorithms and AI in the public’s perception and develop a robust metric for assessing AI aversion. Utilizing a national survey, I employed affective imagery testing to compare Americans emotional responses towards AI, algorithms, and advanced technology. The findings reveal that AI elicits significantly more negative emotional responses than the other two, indicating its unique position in public perception. I then construct the Artificial Intelligence Aversion Index (AIAI) based on responses to policy-related vignettes. Regression analyses showed a strong negative relationship between the AIAI and public support for both current and future AI applications within public policy, with aversion more pronounced towards potential future uses. These insights underscore the importance of understanding public sentiment towards AI to inform policymaking as well as helping to establish a framework by which to evaluate aversion levels.
Development of an RNA virus-based episomal vector with artificial aptazyme for gene silencing
Authors: Komorizono Ryo , Yoshizumi Shima , Tomonaga Keizo
Published: October 2024

RNA virus-based episomal vector (REVec), engineered from Borna disease virus, is an innovative gene delivery tool that enables sustained gene expression in transduced cells. However, the difficulty in controlling gene expression and eliminating vectors has limited the practical use of REVec. In this study, we overcome these shortcomings by inserting artificial aptazymes into the untranslated regions of foreign genes carried in vectors or downstream of the viral phosphoprotein gene, which is essential for vector replication. Non-transmissive REVec carrying GuaM8HDV or the P1-F5 aptazyme showed immediate suppression of gene expression in a guanine or theophylline concentration-dependent manner. Continuous compound administration also markedly reduced the percentage of vector-transduced cells and eventually led to the complete elimination of the vectors from the transduced cells. This new REVec is a safe gene delivery technology that allows fine-tuning of gene expression and could be a useful platform for gene therapy and gene-cell therapy, potentially contributing to the cure of many genetic disorders.

Key points

• We developed a bornavirus vector capable of silencing transgene expression by insertion of aptazyme

• Transgene expression was markedly suppressed in a compound concentration-dependent manner

• Artificial aptazyme systems allowed complete elimination of the vector from transduced cells
The pericoronary adipose tissue attenuation in CT strongly depends on kernels and iterative reconstructions
Authors: Lisi Costanza , Klambauer Konstantin , Moser Lukas J. , Mergen Victor , Manka Robert , Flohr Thomas , Eberhard Matthias , Alkadhi Hatem
Published: October 2024

Objectives

To investigate the influence of kernels and iterative reconstructions on pericoronary adipose tissue (PCAT) attenuation in coronary CT angiography (CCTA).

Materials and methods

Twenty otherwise healthy subjects (16 females; median age 52 years) with atypical chest pain, low risk of coronary artery disease (CAD), and without CAD in photon-counting detector CCTA were included. Images were reconstructed with a quantitative smooth (Qr36) and three vascular kernels of increasing sharpness levels (Bv36, Bv44, Bv56). Quantum iterative reconstruction (QIR) was either switched-off (QIRoff) or was used with strength levels 2 and 4. The fat-attenuation-index (FAI) of the PCAT surrounding the right coronary artery was calculated in each dataset. Histograms of FAI measurements were created. Intra- and inter-reader agreements were determined. A CT edge phantom was used to determine the edge spread function (ESF) for the same datasets.

Results

Intra- and inter-reader agreement of FAI was excellent (intra-class correlation coefficient = 0.99 and 0.98, respectively). Significant differences in FAI were observed depending on the kernel and iterative reconstruction strength level (each, p < 0.001), with considerable inter-individual variation up to 34 HU and intra-individual variation up to 33 HU, depending on kernels and iterative reconstruction levels. The ESFs showed a reduced range of edge-smoothing with increasing kernel sharpness, causing an FAI decrease. Histogram analyses revealed a narrower peak of PCAT values with increasing iterative reconstruction levels, causing a FAI increase.

Conclusions

PCAT attenuation determined with CCTA heavily depends on kernels and iterative reconstruction levels both within and across subjects. Standardization of CT reconstruction parameters is mandatory for FAI studies to enable meaningful interpretations.

Key Points

QuestionDo kernels and iterative reconstructions influence pericoronary adipose tissue (PCAT) attenuation in coronary CT angiography (CCTA)?

FindingsSignificant differences in fat-attenuation-index (FAI) were observed depending on the kernel and iterative reconstruction strength level with considerable inter- and intra-individual variation.

Clinical relevancePCAT attenuation heavily depends on kernels and iterative reconstructions requiring CT reconstruction parameter standardization to enable meaningful interpretations of fat-attenuation differences across subjects.
H+-translocating pyrophosphatases in protozoan parasites
Authors: Araujo-Ruiz Karina , Mondragón-Flores Ricardo
Published: October 2024

Integral membrane pyrophosphatases (mPPases) hydrolyze pyrophosphate. This enzymatic mechanism is coupled with the pumping of H + and/or Na + across membranes, which can be either K + -dependent or K + -independent. Inorganic proton–translocating pyrophosphatases (H + -PPases) can transport protons across cell membranes and are reported in various organisms such as plants, bacteria, and protozoan parasites. The evolutionary implications of these enzymes are of great interest for proposing approaches related to the treatment of parasitic of phytopathogenic diseases. This work presents a literature review on pyrophosphate, pyrophosphatases, their inhibitors and emphasizes H + -PPases found in various medically significant protozoan parasites such as Toxoplasma gondii, the causative agent of toxoplasmosis, and Plasmodium falciparum, the causative agent of malaria, as well as protozoan species that primarily affect animals, such as Eimeria maxima and Besnoitia besnoiti.
Operative Behandlung der Trigeminusneuralgie
Authors: Ahmadi Rezvan , Tronnier Volker Martin
Published: October 2024

Die Schmerzchirurgie zur Behandlung von neuropathischen Schmerzen, zu denen auch die Trigeminusneuralgie (TGN) gehört, wird in die drei Gruppen der Dekompression, Ablation und Neuromodulation eingeteilt. Die Mikrovaskuläre Dekompression (MVD) ist die einzige kausale Therapie der TGN, die insbesondere im Falle der klassischen TGN auf Grund eines nachgewiesenen Gefäß-Nerven-Konflikts in Frage kommt. Zu den ablativen Verfahren gehören, neben den perkutanen, auch radiochirurgische Methoden, die vor allem bei der idiopathischen Trigeminusneuralgie zum Einsatz kommen. Bei irreversiblen Neuropathien des Nervus trigeminus gilt der Therapiealgorithmus anderer neuropathischer Schmerzen und gegebenenfalls der Einsatz neuromodulativer Verfahren. Für die Auswahl der Therapie müssen die Diagnose, die Nebenwirkungen der Medikamente und die individuellen Risiken der Patienten neben den Behandlungsergebnissen berücksichtigt werden (siehe aktuelle S1 Leitlinie der Deutschen Gesellschaft für Neurologie).
Boiling heat transfer by phase-field method
Authors: Roccon Alessio
Published: October 2024

In this work, we propose and test the validity of a phase-field method tailored specifically for modeling boiling phenomena. The method relies on numerical solutions of the Navier–Stokes equations coupled with a phase-field method and the energy equation. The continuity and Navier–Stokes equations have been modified introducing a source term that accounts for phase change. Likewise, in the conservative Allen–Cahn equation (phase-field method) a source term that accounts for the volume is introduced. The system of governing equations is solved using a projection-correction method and equations are discretized using a second-order finite difference approach. Thanks to the numerical discretization employed, a constant coefficient Poisson equation for pressure is obtained, which can be efficiently solved using FFT-based direct solvers. The proposed method is validated against several benchmarks: an interface undergoing vaporization at a constant rate, the Stefan problem, the adsorption problem, and the growth of a 2D vapor bubble. For all the benchmarks, the present method well matches with analytical and archival literature results for a wide range of vapor-to-liquid density ratios, from $$\rho _v/\rho _l = 1$$

ρ
v

/

ρ
l

=
1

down to $$\rho _v/\rho _l \simeq 5 \times 10^{-4}$$

ρ
v

/

ρ
l

≃
5
×

10

-
4

(where $$\rho _v$$

ρ
v

identifies the vapor density and $$\rho _l$$

ρ
l

the liquid density).
Fast convergence of trust-regions for non-isolated minima via analysis of CG on indefinite matrices
Authors: Rebjock Quentin , Boumal Nicolas
Published: October 2024

Trust-region methods (TR) can converge quadratically to minima where the Hessian is positive definite. However, if the minima are not isolated, then the Hessian there cannot be positive definite. The weaker Polyak–Łojasiewicz (PŁ) condition is compatible with non-isolated minima, and it is enough for many algorithms to preserve good local behavior. Yet, TR with an exact subproblem solver lacks even basic features such as a capture theorem under PŁ. In practice, a popular inexact subproblem solver is the truncated conjugate gradient method (tCG). Empirically, TR-tCG exhibits superlinear convergence under PŁ. We confirm this theoretically. The main mathematical obstacle is that, under PŁ, at points arbitrarily close to minima, the Hessian has vanishingly small, possibly negative eigenvalues. Thus, tCG is applied to ill-conditioned, indefinite systems. Yet, the core theory underlying tCG is that of CG, which assumes a positive definite operator. Accordingly, we develop new tools to analyze the dynamics of CG in the presence of small eigenvalues of any sign, for the regime of interest to TR-tCG.
Formal contracts mitigate social dilemmas in multi-agent reinforcement learning
Authors: Haupt Andreas , Christoffersen Phillip , Damani Mehul , Hadfield-Menell Dylan
Published: October 2024

Multi-agent Reinforcement Learning (MARL) is a powerful tool for training autonomous agents acting independently in a common environment. However, it can lead to sub-optimal behavior when individual incentives and group incentives diverge. Humans are remarkably capable at solving these social dilemmas. It is an open problem in MARL to replicate such cooperative behaviors in selfish agents. In this work, we draw upon the idea of formal contracting from economics to overcome diverging incentives between agents in MARL. We propose an augmentation to a Markov game where agents voluntarily agree to binding transfers of reward, under pre-specified conditions. Our contributions are theoretical and empirical. First, we show that this augmentation makes all subgame-perfect equilibria of all Fully Observable Markov Games exhibit socially optimal behavior, given a sufficiently rich space of contracts. Next, we show that for general contract spaces, and even under partial observability, richer contract spaces lead to higher welfare. Hence, contract space design solves an exploration-exploitation tradeoff, sidestepping incentive issues. We complement our theoretical analysis with experiments. Issues of exploration in the contracting augmentation are mitigated using a training methodology inspired by multi-objective reinforcement learning: Multi-Objective Contract Augmentation Learning. We test our methodology in static, single-move games, as well as dynamic domains that simulate traffic, pollution management, and common pool resource management.
Digital sovereignty and artificial intelligence: a normative approach
Authors: Roberts Huw
Published: October 2024

Digital sovereignty is a term increasingly used by academics and policymakers to describe efforts by states, private companies, and citizen groups to assert control over digital technologies. This descriptive conception of digital sovereignty is normatively deficient as it centres discussion on how power is being asserted rather than evaluating whether actions are legitimate. In this article, I argue that digital sovereignty should be understood as a normative concept that centres on authority (i.e., legitimate control). A normative approach to digital sovereignty is beneficial as it supports critical discourse about the desirability of actors’ assertions of control. It is also more closely aligned with traditional definitions of sovereignty that are grounded in ideas of sovereign authority. To operationalise this normative approach to digital sovereignty and demonstrate the deficiencies of a descriptive approach, the role that “Big Tech” companies are playing in controlling artificial intelligence is considered from both perspectives. Through this case study, it is highlighted that Big Tech companies assert a high degree of control (i.e., descriptive digital sovereignty), but that they lack strong input legitimacy and have a questionable amount of output legitimacy. For this reason, it is argued that Big Tech companies should only be considered quasi-sovereigns over AI.