bluuebunny/crossref_metadata_2025 huggingface dataset:
Topology Optimization Using Neural Networks With Conditioning Field Initialization for Improved Efficiency
Authors: Chen Hongrui , Joglekar Aditya , Burak Kara Levent
Published: November 2023

We propose conditioning field initialization for neural network based topology optimization. In this work, we focus on (1) improving upon existing neural network based topology optimization, (2) demonstrating that by using a prior initial field on the unoptimized domain, the efficiency of neural network based topology optimization can be further improved. Our approach consists of a topology neural network that is trained on a case by case basis to represent the geometry for a single topology optimization problem. It takes in domain coordinates as input to represent the density at each coordinate where the topology is represented by a continuous density field. The displacement is solved through a finite element solver. We employ the strain energy field calculated on the initial design domain as an additional conditioning field input to the neural network throughout the optimization. The addition of the strain energy field input improves the convergence speed compared to standalone neural network based topology optimization.
Physics-Informed Neural Networks for Degradation Diagnostics of Lithium-Ion Batteries
Authors: Navidi Sina , Thelen Adam , Li Tingkai , Hu Chao
Published: November 2023

Quantifying the extent of degradation in a lithium-ion battery cell can provide valuable insights into the cell’s state of health. However, physics-based methods capable of diagnosing component-level degradation typically require long-term aging data and are computationally expensive to deploy. This work investigates combining physics-based modeling and data-driven machine learning to retain high diagnostic accuracy while mitigating the need for long-term degradation data. We develop a physics-informed neural network (PINN) algorithm to diagnose cell health in the late aging stage without needing long-term data. Using a small set of early-life experimental data from an aging experiment, we train a neural network using a physics-informed loss function which penalizes discrepancies between the neural network’s and the physics-based model’s estimates of four cell health parameters. The trained network can then estimate cell capacity and diagnose three primary degradation modes in the late-aging stage. The proposed method is evaluated and compared with other machine learning algorithms using data from a long-term (3.5 years) cycling experiment of 16 implantable-grade lithium-ion cells. Cross-validation results show that the proposed PINN algorithm can improve the estimation accuracy of the health parameters compared to a purely data-driven approach and has comparable accuracy to the other two physics-informed machine learning methods.
Numerical simulation of mirages above water bodies
Authors: Horváth Anna , Bámer Balázs , Barnaföldi Gergely Gábor
Published: November 2023

A mirage or fatamorgana is typically an upside-down “mirror” image of a scenery in deserts, over sun-heated roads, or above bodies of water. When the temperature gradient of air is large, as can happen near a surface, it results in a large gradient of the density and the refractive index as a function of height. Mirages appear when light travels through a medium with a gradient in its refractive index and, therefore, get bent towards the higher values, generating reflected images. A computer program that simulates mirages above water using the method of ray tracing has been developed and is presented here in detail for educational purposes. Results on the effect are shown by simulated images for various water-air temperature-difference cases with values ranging from 5 to 0 °C. Comparison of the simulations to a real-life scenario at Lake Balaton, Hungary has also been provided.
Using lock-in detection to build a barcode scanner
Authors: Alexander Riley E. , DiFrischia Maya M. , Doubman Margaret J. , Fabian Dubon Stefany , Goltz Lily , Li Yuqian , Long Rebecca A. , Love Genevieve , Martinez Diers Nina , Melpakkam Matangi , Robinson Catie , Tompkins Elizabeth M. , Vanis Avalon L. B. , Wang Xinrui , Yu Mallory , Spielman Sarah E. , Noel Michael W.
Published: November 2023

Lock-in detection is a widely used experimental technique in which a weak signal is measured by modulating it at a particular frequency. Then, by detecting an experimental output at that frequency, the desired signal can be isolated from much larger-amplitude noise. Here, we report on the implementation and optimization of a homemade laser barcode scanner based on the lock-in technique. Our setup is comprised of components that are readily available in an undergraduate instructional laboratory. The successful transcription of the barcode into a digital signal was achieved, and this digital signal was collected with a simple computer and processed to reveal the encoded number.
Comparison of next generation technologies and bioinformatics pipelines for capsular typing of
Streptococcus pneumoniae
Authors: Henares Desiree , Lo Stephanie W. , Perez-Argüello Amaresh , Redin Alba , Ciruela Pilar , Garcia-Garcia Juan Jose , Brotons Pedro , Yuste Jose , Sá-Leão Raquel , Muñoz-Almagro Carmen
Published: November 2023

Whole genome sequencing (WGS)-based approaches for pneumococcal capsular typing have become an alternative to serological methods.
In silico
serotyping from WGS has not yet been applied to long-read sequences produced by third-generation technologies. The objective of the study was to determine the capsular types of pneumococci causing invasive disease in Catalonia (Spain) using serological typing and WGS and to compare the performance of different bioinformatics pipelines using short- and long-read data from WGS. All invasive pneumococcal pediatric isolates collected in Hospital Sant Joan de Déu (Barcelona) from 2013 to 2019 were included. Isolates were assigned a capsular type by serological testing based on anticapsular antisera and by different WGS-based pipelines: Illumina sequencing followed by serotyping with PneumoCaT, SeroBA, and Pathogenwatch vs MinION-ONT sequencing coupled with serotyping by Pathogenwatch from pneumococcal assembled genomes. A total of 119 out of 121 pneumococcal isolates were available for sequencing. Twenty-nine different serotypes were identified by serological typing, with 24F (
n
= 17; 14.3%), 14 (
n
= 10; 8.4%), and 15B/C (
n
= 8; 6.7%) being the most common serotypes. WGS-based pipelines showed initial concordance with serological typing (>91% of accuracy). The main discrepant results were found at the serotype level within a serogroup: 6A/B, 6C/D, 9A/V, 11A/D, and 18B/C. Only one discrepancy at the serogroup level was observed: serotype 29 by serological testing and serotype 35B/D by all WGS-based pipelines. Thus, bioinformatics WGS-based pipelines, including those using third-generation sequencing, are useful for pneumococcal capsular assignment. Possible discrepancies between serological typing and WGS-based approaches should be considered in pneumococcal capsular-type surveillance studies.
Reaction of 3-(Pyridin-2-yl)-1,2,4-triazine-5-carbonitriles with 2-Amino-4-aryl-1,3-oxazoles in Anhydrous Medium
Authors: Rammohan A. , Krinochkin A. P. , Kopchuk D. S. , Shtaitz Ya. K. , Sharafieva E. R. , Gaviko V. S. , Zyryanov G. V. , Chupakhin O. N.
Published: November 2023

We previously reported the solvent-free reaction of 5-aryl-3-(pyridin-2-yl)-1,2,4-triazine-5-carbo­nitriles with 2-amino-4-aryl-1,3-oxazoles, which afforded 4,5-diaryl-3-hydroxy-2,2′-bipyridine-6-carbonitriles. Similar reaction in anhydrous medium led to the formation of two products, previously described 4,5-diaryl-3-hydroxy-2,2′-bipyridine-6-carbonitriles (up to 44%) and 4,5-diaryl-2,2′-bipyridine-6-carbonitriles (up to 32%).
Laparoscopic totally extraperitoneal exploration of intra-abdominal testis, orchidectomy and inguinal hernia repair in an adult patient
Authors: Gopinathan Athira , Ramachandran Balamurugan , Ramalingam Sivamarieswaran , Kannan Padma
Published: November 2023

The presence of undescended testis predisposes to the development of an inguinal hernia due to the persistent processus vaginalis. This coexistence is not very rare in the paediatric population. Here, we report an adult man who presented with inguinal hernia and an intra-abdominal testis and successfully underwent an extended totally extraperitoneal (e-TEP) approach for extraperitoneal exploration of the testis in the left iliac fossa, and orchidectomy along with inguinal hernia repair. Review of the literature revealed only two case reports in which TEP has been used in the treatment of undescended testis in adults, and in both cases, the testes were intracanalicular. This case, as per our extensive bibliographical research, is the first reported case of an intra-abdominal testis, with descent arrested at the iliac fossa, explored using e-TEP along with inguinal hernia repair. Such minimally invasive procedures may be offered to the patients without the risks of intraperitoneal entry.
Atypical case of coexistent vascular compression syndromes: median arcuate ligament syndrome and nutcracker syndrome
Authors: Donnelly Liam , Turner Benedict , Davies Alun H
Published: November 2023

Vascular compression syndromes, including median arcuate ligament syndrome (MALS) and nutcracker syndrome (NCS), are poorly understood and frequently delayed diagnoses. This case describes a young adult female presenting with chronic vomiting, abdominal pain and weight loss, with dependence on nasogastric feeding. Subsequent to her gastrointestinal symptoms, she developed haematuria and orthostatic intolerance. Investigations confirmed NCS and possible MALS, with superadded gastroparesis and bradygastria. Under the joint care of general and vascular surgeons, she underwent a gastrojejunostomy and panelled renocaval bypass which led to partial resolution of her symptoms. It is hypothesised that gastroparesis may have been caused by MALS via a neurogenic mechanism, or coexistent compression of the duodenum by the superior mesenteric artery. This case highlights the difficulty in diagnosis of vascular compression syndromes, the overlap between the conditions and the potential for multiple coexistent conditions which complicate diagnosis and lead to increased lead-time and morbidity for patients.
Comparative survey among paediatricians, nurses and health information technicians on ethics implementation knowledge of and attitude towards social experiments based on medical artificial intelligence at children’s hospitals in Shanghai: a cross-sectional study
Authors: Wang Yingwen , Fu Weijia , Gu Ying , Fang Weihan , Zhang Yuejie , Jin Cheng , Yin Jie , Wang Weibing , Xu Hong , Ge Xiaoling , Ye Chengjie , Tang Liangfeng , Fang Jinwu , Wang Daoyang , Su Ling , Wang Jiayu , Zhang Xiaobo , Feng Rui
Published: November 2023

Objectives

Implementing ethics is crucial to prevent harm and promote widespread benefits in social experiments based on medical artificial intelligence (MAI). However, insufficient information is available concerning this within the paediatric healthcare sector. We aimed to conduct a comparative survey among paediatricians, nurses and health information technicians regarding ethics implementation knowledge of and attitude towards MAI social experiments at children’s hospitals in Shanghai.

Design and setting

A cross-sectional electronic questionnaire was administered from 1 July 2022 to 31 July 2022, at tertiary children’s hospitals in Shanghai.

Participants

All the eligible individuals were recruited. The inclusion criteria were as follows: (1) should be a paediatrician, nurse and health information technician, (2) should have been engaged in or currently participating in social experiments based on MAI, and (3) voluntary participation in the survey.

Primary outcome

Ethics implementation knowledge of and attitude to MAI social experiments among paediatricians, nurses and health information technicians.

Results

There were 137 paediatricians, 135 nurses and 60 health information technicians who responded to the questionnaire at tertiary children’s hospitals. 2.4–9.6% of participants were familiar with ethics implementation knowledge of MAI social experiments. 31.9–86.1% of participants held an ‘agree’ ethics implementation attitude. Health information technicians accounted for the highest proportion of the participants who were familiar with the knowledge of implementing ethics, and paediatricians or nurses accounted for the highest proportion among those who held ‘agree’ attitudes.

Conclusions

There is a significant knowledge gap and variations in attitudes among paediatricians, nurses and health information technicians, which underscore the urgent need for individualised education and training programmes to enhance MAI ethics implementation in paediatric healthcare.
Using SUpported Motivational InTerviewing (SUMIT) to increase physical activity for people with knee osteoarthritis: a pilot, feasibility randomised controlled trial
Authors: Bell Emily Catherine , O'Halloran Paul , Wallis Jason A , Crossley Kay M , Gibbs Alison J , Lee Annemarie , Jennings Sophie , Barton Christian J
Published: November 2023

Objective

The objective of this study was to determine the feasibility and effectiveness of using SUpported Motivational InTerviewing (SUMIT) to increase physical activity in people with knee osteoarthritis (KOA).

Design

Randomised controlled trial.

Setting

We recruited people who had completed Good Life with osteoArthritis Denmark (GLA:D) from private, public and community settings in Victoria, Australia.

Interventions

Participants were randomised to receive SUMIT or usual care. SUMIT comprised five motivational interviewing sessions targeting physical activity over 10 weeks, and access to a multimedia web-based platform.

Participants

Thirty-two participants were recruited (17 SUMIT, 15 control) including 22 females (69%).

Outcome measures

Feasibility outcomes included recruitment rate, adherence to motivational interviewing, ActivPAL wear and drop-out rate. Effect sizes (ESs) were calculated for daily steps, stepping time, time with cadence >100 steps per minute, time in bouts >1 min; 6 min walk distance, Knee Osteoarthritis Outcome Score (KOOS) subscales (pain, symptoms, function, sport and recreation, and quality of life (QoL)), Euroqual, systolic blood pressure, body mass index, waist circumference, 30 s chair stand test and walking speed during 40 m walk test.

Results

All feasibility criteria were achieved, with 32/63 eligible participants recruited over seven months; with all participants adhering to all motivational interviewing calls and achieving sufficient ActivPAL wear time, and only two drop-outs (6%).

12/15 outcome measures showed at least a small effect (ES>0.2) favouring the SUMIT group, including daily time with cadence >100 steps per minute (ES=0.43). Two outcomes, walking speed (ES= 0.97) and KOOS QoL (ES=0.81), showed a large effect (ES>0.8).

Conclusion

SUMIT is feasible in people with knee osteoarthritis. Potential benefits included more time spent walking at moderate intensity, faster walking speeds and better QoL.

Trial registration number

ACTRN12621000267853.
Synergistic effect of Tai Chi and transcranial direct current stimulation on memory function in patients with mild cognitive impairment: study protocol for a 2×2 factorial randomised controlled trial
Authors: Wu Mengyuan , Liu Hong , Huang Jia , Liu Weilin , Liu Zhizhen , Xu Ying
Published: November 2023

Introduction

Interventions at the mild cognitive impairment (MCI) stage prevent or delay the progression of cognitive decline. In recent years, several studies have shown that physical exercise combined with transcranial direct current stimulation (tDCS) effectively delays the disease and promotes cognitive recovery in patients with MCI. This study aims to determine whether Tai Chi (TC) combined with tDCS can significantly improve memory in patients with MCI compared with TC or tDCS alone.

Methods and analysis

This clinical trial will use a 2×2 factorial design, enrolling 128 community-dwelling MCI patients, randomly categorised into four groups: TC, tDCS, TC combined with tDCS and the health education group. Outcome measures will include the Chinese Wechsler Memory Scale-Revised, Auditory Verbal Learning Test and Rey-Osterrieth Complex Figure Test. All assessments will be conducted at baseline and 3 months after the intervention. All analyses will use intention-to-treat or per-protocol methods.

Ethics and dissemination

Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of the Fujian University of Traditional Chinese Medicine (2022KY-002–01). The results of the study will be disseminated through peer-reviewed publications and at scientific conferences.

Trial registration number

ChiCTR2200059316.
Are pharmacists on the front lines of the opioid epidemic? A cross-sectional study of the practices and competencies of community and hospital pharmacists in Punjab, Pakistan
Authors: Mubarak Naeem , Zahid Taheer , Rana Fatima Rahman , Ijaz Umm-E-Barirah , Shabbir Afshan , Manzoor Mahrukh , Khan Nahan , Arif Minahil , Naeem Muhammad Mehroz , Kanwal Sabba , Saif-ur-Rehman Nasira , Zin Che Suraya , Mahmood Khalid , Asgher Javaid , Elnaem Mohamed Hassan
Published: November 2023

Introduction

Countries are grappling with a rapidly worsening upsurge in the opioid-related overdose deaths, misuse and abuse. There is a dearth of data in Pakistan regarding the practices and competencies of pharmacists in handling opioid-related issues.

Study design

A cross-sectional study, conducted across Punjab, Pakistan.

Method

The study deployed a validated survey to evaluate the competencies and practices of the community and hospital pharmacists.

Results

504 community pharmacists and 279 hospital pharmacists participated in the survey with an overall response rate of 85.5%. Almost half of the respondents ‘never’ or ‘sometimes’ made clinical notes in a journal or dispensing software to monitor ongoing opioid use. Generally, pharmacists were reluctant to collaborate with physicians or notify police regarding the abuse/misuse of opioids. Hospital pharmacists achieved significantly higher mean competency scores than chain and independent community pharmacists (p<0.05). In competency evaluation, three priority areas emerged that require additional training, that is, ‘opioid overdose management’, ‘opioid use monitoring’ and ‘therapeutic uses of opioids’.

Conclusion

Both community and hospital pharmacists hold significant positions and potential to contribute meaningfully to the mitigation of harms and risks associated with opioids. Nevertheless, this study underscores notable deficiencies in the competence of pharmacists, whether in hospital or community settings in Punjab, concerning various aspects related to the dispensing and utilisation of opioids. It also highlights the pressing need for the development of strategies aimed at improving several practice areas including the documentation, the quality of patient counselling, the effectiveness of reporting mechanisms for opioid abuse and the stringent enforcement of regulatory policies to curtail opioid misuse. Thus, to mitigate the opioid epidemic in Pakistan, it is imperative to institute opioid stewardship initiatives aimed at rectifying the competency and procedural deficiencies within the pharmacist workforce.
Beta-blockers reduce severe exacerbation in patients with mild chronic obstructive pulmonary disease with atrial fibrillation: a population-based cohort study
Authors: Lin Shan-Ju , Liao Xin-Min , Chen Nai-Yu , Chang Yu-Ching , Cheng Ching-Lan
Published: November 2023

Background and objective

Beta-blockers (BBs) decrease mortality and acute exacerbation (AE) rates in patients with chronic obstructive pulmonary disease (COPD) and cardiovascular disease; however, information on their effects in patients with COPD and atrial fibrillation (AF) is limited. We aimed to assess the AE risk in patients with different severities of COPD and AF receiving BBs compared with that in patients receiving calcium channel blockers (CCBs).

Methods

This retrospective cohort study used data from the Taiwan National Health Insurance Database from 2009 to 2018. Outcomes included AE-related emergency room visits and hospitalisation. HRs and 95% CIs were estimated using the Cox proportional hazards model. COPD severity was classified as mild or severe based on exacerbation history. Sensitivity analyses included treatment and subgroup analyses, and competing risk adjustment.

Results

After propensity score matching, 4486 pairs of BB and CCB users from 13 462 eligible patients were included. The exacerbation risk for BB users was lower (HR 0.80; 95% CI 0.72 to 0.89) than that of CCB users. After stratification, BB benefits persisted in the mild COPD group (HR 0.75; 95% CI 0.66 to 0.85), unlike the severe COPD group (HR 0.95; 95% CI 0.75 to 1.20). The results of the subgroup analysis showed consistent protective effects even in patients without heart failure or myocardial infarction (adjusted HR 0.82; 95% CI 0.71 to 0.94).

Conclusion

We found that BB use in patients with mild COPD and AF was associated with a lower exacerbation risk than CCB use, and that close monitoring of BB use in patients with severe COPD and AF is warranted.
Medical student attitudes to patient involvement in healthcare decision-making and research
Authors: O'Neill Jennifer , Docherty Stewart Bronwyn , Ng Anna , Roy Yamini , Yousif Liena , McIntyre Kirsty R
Published: November 2023

Objective

Patient involvement is used to describe the inclusion of patients as active participants in healthcare decision-making and research. This study aimed to investigate incoming year 1 medical (MBChB) students’ attitudes and opinions regarding patient involvement in this context.

Methods

We established a staff–student partnership to formulate the design of an online research survey, which included Likert scale questions and three short vignette scenarios designed to probe student attitudes towards patient involvement linked to existing legal precedent. Incoming year 1 medical students (n=333) were invited to participate in the survey before formal teaching commenced.

Results

Survey data (49 participants) indicate that students were broadly familiar with, and supportive of, patient involvement in medical treatment. There was least support for patient involvement in conducting (23.9%), contributing to (37.0%) or communicating research (32.6%), whereas there was unanimous support for patients choosing treatment from a selection of options (100%).

Conclusion

Incoming members of the medical profession demonstrate awareness of the need to actively involve patients in healthcare decision-making but are unfamiliar with the utility and value of such involvement in research. Further empirical studies are required to examine attitudes to patient involvement in healthcare.
Artificial intelligence (AI) for neurologists: do digital neurones dream of electric sheep?
Authors: Au Yeung Joshua , Wang Yang Yang , Kraljevic Zeljko , Teo James T H
Published: November 2023

Artificial intelligence (AI) is routinely mentioned in journals and newspapers, and non-technical outsiders may have difficulty in distinguishing hyperbole from reality. We present a practical guide to help non-technical neurologists to understand healthcare AI. AI is being used to support clinical decisions in treating neurological disorders. We introduce basic concepts of AI, such as machine learning and natural language processing, and explain how AI is being used in healthcare, giving examples its benefits and challenges. We also cover how AI performance is measured, and its regulatory aspects in healthcare. An important theme is that AI is a general-purpose technology like medical statistics, with broad utility applicable in various scenarios, such that niche approaches are outpaced by approaches that are broadly applicable in many disease areas and specialties. By understanding AI basics and its potential applications, neurologists can make informed decisions when evaluating AI used in their clinical practice. This article was written by four humans, with generative AI helping with formatting and image generation.
Awareness and knowledge of the Canadian 24-Hour Movement Guidelines for Adults among adults living in Canada
Authors: Kauffeldt Kaitlyn D. , Varkul Olivia , Latimer-Cheung Amy E. , Faulkner Guy , Brouwers Melissa C. , Chulak-Bozzer Tala , Jones Rebecca , Lane Kirstin N. , Weston Zachary J. , Tomasone Jennifer R.
Published: November 2023

Awareness and knowledge of national movement behaviour guidelines are needed to influence individual behaviour and public health policies. This study assessed the awareness and knowledge of the Canadian 24-Hour Movement Guidelines for Adults Aged 18–64 Years and Adults Aged 65 Years or Older (24HMG) recommendations among adults living in Canada across three timepoints. Online surveys were distributed to representative samples of adults living in Canada over a 6-month period. Findings suggest that short-term dissemination efforts were successful in increasing awareness of the 24HMG following guideline release. However, other strategies, such as education, may be needed to influence knowledge of guideline recommendations.
The hidden sector variations in the $$\mathcal{N}=1$$ supersymmetric three-family Pati–Salam models from intersecting D6-branes
Authors: Mansha Adeel , Li Tianjun , Wu Lina
Published: November 2023

It is well-known that three-family supersymmetric Pati–Salam models from intersecting D6-branes, where either one or both of the $$\textrm{U}(2)$$

U
(
2
)

gauge factors are replaced by a $$\textrm{USp}(2)$$

USp
(
2
)

group, are quite scarce. In order to construct all such kind of models with generic additional gauge symmetries, we fix the observable sectors and study all the possible hidden sectors. Thus, we are able to completely determine all types of such kind of the inequivalent models on a $$\mathbb {T}^6/(\mathbb {Z}_2\times \mathbb {Z}_2)$$

T
6

/

(

Z
2

×

Z
2

)

orientifold from IIA string theory. We find the gauge coupling relations to be highly sensitive to the variations in the hidden sector. One of the models exhibits the gauge coupling unification for a particular solution at the string scale. In addition, we perform scan on the hidden sector variations for the models presented in arXiv:2112.09632, whose gauge coupling relations are still preserved. Thus, we fix the gap in the previous study and complete the model building for all the inequivalent models.
Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity
Authors: Anselmi Damiano
Published: November 2023

Quantum gravity is extended to include purely virtual “cloud sectors”, which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their off-shell correlation functions perturbatively. The ordinary on-shell correlation functions and the S matrix elements are unaffected. Each extra sector is made of a cloud field, its anticommuting partner, a “cloud-fixing” function and a cloud Faddeev-Popov determinant. The additional fields are purely virtual, to ensure that no ghosts propagate. The extension is unitary. In particular, the off-shell, diagrammatic version of the optical theorem holds. The one-loop two-point functions of dressed scalars, vectors and gravitons are calculated. Their absorptive parts are positive, cloud independent and gauge independent, while they are unphysical if non purely virtual clouds are used. We illustrate the differences between our approach to the problem of finding a complete set of observables in quantum gravity and other approaches available in the literature.
Approximating Minimum k-Tree Cover of a Connected Graph Inspired by the Multi-Ferry Routing in Delay Tolerant Networks
Authors: Satoshi Fujita
Published: November 2023

In this paper, we consider the problem of covering the vertex set of a given graph by [Formula: see text] trees so as to minimize the maximum weight of the trees, as a subproblem of the multi-ferry scheduling problem proposed by Zhao and Ammar. After pointing out that the approximation ratio of a greedy scheme based on the Kruskal’s algorithm is provably bad, we show that the approximation ratio cannot be better than 3/2 for [Formula: see text] even when the edge selection criterion is modified so as to minimize the increase in the maximum weight in the collection of trees. We then propose two polynomial-time algorithms with a guaranteed approximation ratio. The first algorithm achieves 3-approximation for the class of graphs in which the edge weights satisfy the triangle inequality. The second algorithm achieves 4-approximation for any connected graph with arbitrary edge weights.
On exponential stability of switched functional differential equations with average dwell-time
Authors: Ngoc Pham Huu Anh , Hieu Le Trung , Tran Thai Bao
Published: November 2023

We present a novel approach to the exponential stability of switched functional differential equations. Our approach does not involve Lyapunov functions. It is simple and based upon spectral properties of Metzler matrices, a comparison principle and the average dwell-time technique. Consequently, some new explicit criteria for the exponential stability of switched functional differential equations are derived. Some illustrative examples are given.
Contextual Adversarial Representation Learning for Multiword Expressions
Authors: An Bo
Published: November 2023

Word composition is a promising method to learn the representations of long text. Unfortunately, word composition falls short when inferring representations for non-compositional multiword expressions, such as “go banana.” Presently, many methods treat multiword expressions as single words and learn their representations in a manner similar to individual word representations. However, numerous multiword expressions exhibit ambiguity, expressing distinct meanings, whether literal or idiomatic, depending on the context. In response to these challenges, our paper proposes an adversarial context-aware representation learning method for multiword expressions, which generates representations based on the contexts of their occurrences. An adversarial training framework is introduced to further enhance the representation learning method. Experimental results confirm the benefits of sense disambiguation for multiword expressions in representation learning. Moreover, our proposed method demonstrates competitive performance on idiom token classification and compositionality prediction tasks.
A Two-Mode, Adaptive Security Framework for Smart Home Security Applications
Authors: Sisodia Devkishen , Li Jun , Mergendahl Samuel , Cam Hasan
Published: November 2023

With the growth of the Internet of Things (IoT), the number of cyber attacks on the Internet is on the rise. However, the resource-constrained nature of IoT devices and their networks makes many classical security systems ineffective or inapplicable. We introduce TWINKLE, a two-mode, adaptive security framework that allows an IoT network to be in regular mode for most of the time, which incurs a low resource consumption rate, and to switch to vigilant mode only when suspicious behavior is detected, which potentially incurs a higher overhead. Compared to the early version of this work, this article presents a more comprehensive design and architecture of TWINKLE, describes challenges and details in implementing TWINKLE, and reports evaluations of TWINKLE based on real-world IoT testbeds with more metrics. We show the efficacy of TWINKLE in two case studies where we examine two existing intrusion detection and prevention systems and transform both into new, improved systems using TWINKLE. Our evaluations show that TWINKLE is not only effective at securing resource-constrained IoT networks, but can also successfully detect and prevent attacks with a significantly lower overhead and detection latency than existing solutions.
Ulterior Motives
Authors: Hoffmann Leah
Published: November 2023

2023--2024 ACM Athena Lecturer Margo Seltzer recalls the motivations behind the development of the Berkeley DB database software library, and other achievements during her career.
Halfway Around the World
Authors: Neville-Neil George V.
Published: November 2023

Learn the language, meet the people, eat the food.
Comparing Chatbots Trained in Different Languages
Authors: Chayka Antony , Sukhov Andrei
Published: November 2023

The
Communications
website, https://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

https://cacm.acm.org/blogs/blog-cacm

Antony Chayka and Andrei Sukhov examine how training chatbots in English or Russian affects their responses.
Factors That Predict K-12 Teachers' Ability to Apply Computational Thinking Skills
Authors: Tagare Deepti
Published: November 2023

Background and Objective.
Teacher assessment research suggests that teachers have good conceptual understanding of CT. However, to model CT-based problem-solving in their classrooms, teachers need to develop the ability to recognize when and how to apply CT skills. Does existing professional development (PD) equip teachers to know when and how to apply CT skills? What factors should PD providers consider while developing trainings for CT application skills?

Method.
This retrospective observational study used a binomial regression model to determine what factors predict teachers’ probability of performing well on a CT application skills test.

Participants.
Participants of this study were 129 in-service K-12 teachers from a community of practice in India.

Findings.
Results show that teachers who have received at least one CT training, who have a higher teaching experience, and are currently teaching CT will have a higher probability of applying CT skills correctly to problems irrespective of the subject they teach and their educational backgrounds. However, receiving a higher number of CT PD trainings was a negative predictor of teachers’ performance.

Implications.
Implications for school administrators, professional development providers, and researchers are discussed. Teachers need ample opportunity to teach CT in their teaching schedules. Continuous professional development does not necessarily result in improved CT application skills unless careful consideration is given to the pedagogies used and to the resolution of misconceptions that teachers may have developed in prior training. Mixing plugged and unplugged pedagogical approaches may be beneficial to encourage transfer of CT application skills across different types of problems. Last, there is a need to develop valid and reliable instruments that measure CT application skills of teachers.
Endovascular Microrobotics for Neurointervention
Authors: Santiago-Dieppa David R. , Friend James
Published: November 2023

Endovascular techniques have revolutionized the treatment of cerebrovascular disease in the human brain. In this review, we examine the current state of this technology, which consists of multiple concentric catheters that are manually navigated from the lumen of peripheral arterial access within the patient's arm or leg up into the brain using fluoroscopic image guidance. There is tremendous potential for the fields of robotics, materials science, and computer science to redefine the current techniques and ultimately improve the safety and efficacy of treatments.
Physically Assistive Robots: A Systematic Review of Mobile and Manipulator Robots That Physically Assist People with Disabilities
Authors: Nanavati Amal , Ranganeni Vinitha , Cakmak Maya
Published: November 2023

More than 1 billion people in the world are estimated to experience significant disability. These disabilities can impact people's ability to independently conduct activities of daily living, including ambulating, eating, dressing, taking care of personal hygiene, and more. Mobile and manipulator robots, which can move about human environments and physically interact with objects and people, have the potential to assist people with disabilities in activities of daily living. Although the vision of physically assistive robots has motivated research across subfields of robotics for decades, such robots have only recently become feasible in terms of capabilities, safety, and price. More and more research involves end-to-end robotic systems that interact with people with disabilities in real-world settings. In this article, we survey papers about physically assistive robots intended for people with disabilities from top conferences and journals in robotics, human–computer interactions, and accessible technology, to identify the general trends and research methodologies. We then dive into three specific research themes—interaction interfaces, levels of autonomy, and adaptation—and present frameworks for how these themes manifest across physically assistive robot research. We conclude with directions for future research.
Implications of Social Media for a Changing Work Landscape
Authors: Behrend Tara S. , Ravid Daniel M. , Thapa Stuti
Published: November 2023

More than half of the global population now uses social media. This technological ubiquity has transformed the way that individuals communicate and engage with the world around them, and consequently has had drastic effects on modern work. In the 20 years since early social media platforms such as LinkedIn and Myspace were first launched, much research on the consequences of social media has been conducted in the fields of organizational psychology and organizational behavior. In this article, we review this body of literature, highlighting the ways that social media has changed modern work, both in changing organizational behavior and human resource management and in changing the nature of work itself. We detail ethical, legal, and practical challenges that have arisen in this changing landscape and conclude with recommendations for additional research on this topic.
Distributed Computing and Inference for Big Data
Authors: Zhou Ling , Gong Ziyang , Xiang Pengcheng
Published: November 2023

Data are distributed across different sites due to computing facility limitations or data privacy considerations. Conventional centralized methods—those in which all datasets are stored and processed in a central computing facility—are not applicable in practice. Therefore, it has become necessary to develop distributed learning approaches that have good inference or predictive accuracy while remaining free of individual data or obeying policies and regulations to protect privacy. In this article, we introduce the basic idea of distributed learning and conduct a selected review on various distributed learning methods, which are categorized by their statistical accuracy, computational efficiency, heterogeneity, and privacy. This categorization can help evaluate newly proposed methods from different aspects. Moreover, we provide up-to-date descriptions of the existing theoretical results that cover statistical equivalency and computational efficiency under different statistical learning frameworks. Finally, we provide existing software implementations and benchmark datasets, and we discuss future research opportunities.
ORR Activity and Voltage-Cycling Stability of a Carbon-Supported PtxY Alloy Catalyst Evaluated in a PEM Fuel Cell
Authors: Loichet Torres Paulette A. , Li Yan-Sheng , Grön Corbinian , Lazaridis Timon , Watermeyer Philipp , Cheng Ningyan , Liebscher Christian H. , Gasteiger Hubert A.
Published: November 2023

Platinum-yttrium alloys (PtxY) are suggested to have superior oxygen reduction reaction (ORR) activity and long-term stability in proton exchange membrane fuel cells (PEMFCs). However, the actual ORR activity and stability of a PtxY catalyst with a high electrochemically active surface area (ECSA) in a PEMFC remains uncertain. Here, a Ketjen black (KB) carbon supported PtxY/KB catalyst with a high ECSA (∼60 m2/g) was synthesized using a carbon nitride precursor. Based on elemental analysis, XRD, electron microscopy, and a mass-balance based model, it was shown that the acid-leached PtxY nanoparticles of the catalyst consist of a ∼0.7 nm thick Pt-shell and a Pt3Y core. Rotating disk electrode (RDE) and 5 cm2 single-cell PEMFC measurements indicated that the ORR activity of the acid-leached PtxY/KB catalyst is similar to an analogously synthesized Pt/KB reference catalyst with the same ECSA. Voltage-cycling accelerated stress tests (ASTs) between 0.6−1.0 V (in H2/N2 at 80 °C/95% RH) in 5 cm2 single-cells showed that the ORR activity and durability of the PtxY/KB catalyst is similar to that of the Pt/KB reference catalyst. Thus, the high durability of Pt-rare Earth alloys that has been claimed on the basis of RDE measurements is not observed in actual PEMFCs.
Unveiling the Robust Struct-Electromagnetic Characteristics of CdAB2 Chalcopyrite (A = Cr, Mn, Fe; B = P, As): A Comprehensive Ab-Initio Study
Authors: Vijayalakshmi D. , Ramachandran Tholkappiyan , Jaiganesh G. , Kalpana G. , Hamed Fathalla
Published: November 2023

We present a comprehensive investigation of the electromagnetic properties of CdAB2 compounds, where A represents Cr, Mn, or Fe, and B denotes P or As. To investigate the spin-polarized behavior of these compounds the A atoms were substituted at the Group IV (Ge) position in CdGeB2 in the chalcopyrite crystal structure. Our results reveal that all the CdAB2 compounds exhibit compelling spin-splitting of energy states near the Fermi level (EF). Notably, CdAB2 materials with A = Cr and Mn exhibit intriguing half-metallic ferromagnetic (HMF) characteristics, with the calculated total magnetic moments of 2.00 and 3.00 µB/f.u., respectively. The HMF properties originated in CdAB2 (A = Cr and Mn; B = P, As) these compounds owing to the hybridization of partially filled -3d(t2g) states of A atoms with the p-states of B (P, As) atoms, with minor contributions from Cd’s-like states. In contrast, CdFeB2 displays distinct behavior, demonstrating spin-splitting of energy levels around the EF indicative of a stable ferromagnetic (FM) state and the absence of HMF at their equilibrium volume. The calculated total magnetic moments for CdFeP2 and CdFeAs2 are about 1.83 (1.64 µB/f.u.) and 1.94 µB/f.u. (1.84 µB/f.u.) under generalized gradient approximation (GGA) (local spin density approximation (LSDA)) approximations, respectively. Perhaps these CdAB2 compounds (A = Cr and Mn; B = P, As) with HMF characteristic within both LSDA and GGA formalisms makes them highly promising candidates for spin injectors in the spintronic device applications. Furthermore, their semiconducting nature renders CdCrB2 and CdMnB2 materials compatible with silicon and other semiconducting lattices, enhancing their potential practical applications in the spintronic technologies. In conclusion, this study presents a thorough exploration of the robust electronic and magnetic properties of CdAB2 chalcopyrites, offering exciting prospects for their utilization in the future spintronic applications.
Exploring the Molecular Mechanism of the Antioxidant Activity of Medicine and Food Homology Licorice Flavonoids Based on Pharmacophore Theory and Quantum Calculations
Authors: Hu Yi , Liang Peiyi , Wang Zhuxian , Jiang CuiPing , Guo Yinglin , Chen Hongkai , Shen Chunyan , Wu Yufan , Liu Li , Yi Yankui , Liu Qiang , Zhu Hongxia
Published: November 2023

Licorice flavonoids are a kind of flavonoids extracted from the root of licorice, which have good antioxidant activity and are widely used in the food industry. In the early research of the research group, it has been found that the antioxidant activity of licorice flavonoids can be altered by solvent mediation. However, the molecular mechanism underlying the antioxidant properties of licorice flavonoids is still not fully understood. Therefore, this study aims to explore the molecular mechanism underlying the antioxidant activity of licorice flavonoids based on the principles of pharmacophore theory and quantum computing. Firstly, network pharmacology will be employed to study the antioxidant properties of licorice flavonoids. The major active components and key structural features responsible for the antioxidant activity in licorice flavonoids will be screened using pharmacophore theory and further validated through molecular docking. Lastly, quantum computing will be utilized to uncover the potential mechanism underlying their antioxidant activity. Pharmacophore studies have shown that licochalcone B, retrochalcone, isoliquiritin, and isoliquiritigenin exhibit low predicted IC50 values, indicating that these compounds are key components of licorice flavonoids in the antioxidant process. Molecular electrostatic potential (MEP) and frontier molecular orbital studies have shown that licochalcone B, retrochalcone, isoliquiritin, and isoliquiritigenin all exhibit certain chemical reactivity. Quantum computing studies have found that the para-phenol hydroxyl group on the core structure of licochalcone B, isoliquiritigenin, retrochalcone, and isoliquiritin is a crucial functional group for the antioxidant activity of flavonoid compounds. In general, this study successfully elucidated the mode of action of licorice flavonoids in the antioxidant process, providing some guidance for the synthesis of new antioxidant compounds.
Renewable Energy Consumption in G-7 Countries: Evidence from a Dynamic Panel Investigation
Authors: Rahman Mohammad Mafizur , Raeisi Sarkandiz Mostafa
Published: November 2023

The necessity of transitioning from the fossil fuels era to a green economy based on renewable energy resources has become increasingly urgent. This is in order to minimize the impact of energy supply fluctuations and combat global warming, especially in the wake of the recent oil price shock due to the Russian invasion of Ukraine. The present study is aimed at identifying and analyzing the most influential variables affecting renewable energy consumption (REC) among the G-7 countries using a log-linear dynamic panel model that covers the data period from 1996 to 2018. The results indicated that foreign direct investment (FDI) and regulatory quality index (RQI) have negative impacts on REC, while urbanization and GDP per capita have positive influences. Furthermore, urbanization has the highest absolute value coefficient, which is equal to 1.26. This means that a one percent increase in urban population will lead to about a 1.26 percent increase in REC. This finding highlights the importance of planned urbanization and converting buildings and houses into environmentally friendly structures to promote REC. Also, the positive effect of GDP per capita on REC suggests that stable economic growth will enhance the share of REC in total energy consumption. Thus, the countries should robust their economies against exogenous shocks like energy price jumps. Finally, a two-stage Granger-type cointegration test showed that the variables are in a long-run and stable relationship, which implies the reliability of the research findings.
Exponentially Generated Modified Chen Distribution with Applications to Lifetime Dataset
Authors: Kabiru Abidemi Awopeju , Abiodun Alfred A.
Published: November 2023

In this paper, the exponentially generated system was used to modify a two-parameter Chen distribution to a four-parameter distribution with better performance. The property of complete probability distribution function was used to verify the completeness of the resulting distribution, which shows that the distribution is a proper probability distribution function. A simulation study involving varying sample sizes was used to ascertain the asymptotic property of the new distribution. Small and large sample sizes were considered which shows the closeness of the estimates to the true value as the sample size increases. Lifetime dataset were used for model comparison which shows the superiority of exponentially generated modify Chen distribution over some existing distributions. It is therefore recommended to use the four-parameter Chen distribution in place of the well-known two-parameter Chen distribution.