bluuebunny/crossref_metadata_2025 huggingface dataset:
Mobile-assisted language learning and pronunciation instruction: A systematic literature review
Authors: Metruk Rastislav
Published: February 2024

In recent years, learners worldwide have expressed increasing interest in mobile learning and the utilization of mobile devices for language learning purposes. However, few research synthesis studies have focused on pronunciation development in relation to employing MALL (mobile-assisted language learning). This review article contributes to the discourse on how mobile learning aids in acquiring and practicing EFL (English as a foreign language) pronunciation since it is this language system that is both a crucial and frequently neglected aspect of English language learning. With the emergence of e-generation, it is necessary to investigate the influence of MALL on pronunciation acquisition. This paper provides a systematic literature review of the findings of 15 empirical studies published between 2015 and 2022, which is based on PRISMA 2020. The aim of the review is threefold: to investigate the effect of mobile devices on L2 learners’ pronunciation performance, examine learners’ attitudes toward employing mobile learning for pronunciation practice and development, and identify which mobile devices and apps are present in the process. The results indicate that overall, mobile learning exerts a beneficial impact on L2 pronunciation and that participants in the reviewed studies demonstrate positive attitudes toward MALL. Moreover, smartphones appear to be at the center of attention as the primary mobile device, and it was revealed that a variety of mobile apps and platforms have been employed in the studies. The article concludes with pedagogical implications and recommendations for potential research exploration in the future.
The influence of content-relevant background color as a retrieval cue on learning with multimedia
Authors: Meusel Felicia , Scheller Nadine , Rey Günter Daniel , Schneider Sascha
Published: February 2024

Color has been investigated as a signaling cue in multimedia learning environments, guiding the learner’s attention and as an emotional design element, increasing the learner’s motivation and, thus, improving learning outcomes. Retrieval cues (e.g., visual cues, odor, sound) facilitating memory retrieval have been primarily investigated in learning simple word lists. Contrary to additional retrieval cues, the background color is a component that is always present in multimedia learning environments. This study investigates if the background color of learning texts as retrieval cue can enhance learning and affect cognitive load and motivation. Hypotheses are formulated according to the Cognitive-Affective Theory of Learning with Multimedia (CATLM) and in the setting of context-dependent memory, specifically the Information, associated Context, and Ensemble Theory (ICE). A 2 (related vs. unrelated background color) × 2 (with vs. without colors in the learning test) -factorial between-subjects design with an additional control group was utilized. For the control group, the background of the learning texts and learning questions was white. In total, 191 native German speakers were randomly assigned to the five groups. The findings indicate that relying solely on the background color as a retrieval cue is insufficient. Instead of facilitating memory retrieval, the background color remains context information stored separately from the item information. However, the results should be approached carefully as learning outcomes may be subject to ceiling and floor effects.
The Lighter Touch: Less-Restriction in Sequentially Implemented Behavioral Sleep Interventions for Children with Rare Genetic Neurodevelopmental Conditions
Authors: Woodford Emma C. , McLay Laurie K. , France Karyn G. , Blampied Neville M.
Published: February 2024

Purpose

The prevalence of sleep difficulties among children with rare genetic neurodevelopmental conditions (RGNC) is high. Behavioral interventions are commonly used in the treatment of sleep difficulties in children with neurodevelopmental conditions such as autism, however, research is scarce in children with RGNC. The range of co-occurring complexities within this population, means there is a need for research to not only determine the effectiveness of behavioral sleep interventions, but also which components might be the least restrictive (i.e., intensive/aversive) and minimally sufficient.

Methods

This study used a single-case multiple baseline design to investigate the effectiveness and acceptability of behavioral sleep interventions, indicated within a Functional Behavior formulation in eight children with RGNC (M = 7.3 years). Intervention components were sequentially administered across up to three phases, based on the principle of less restriction (from least to relatively more intensive) to determine what might be minimally sufficient.

Results

Results showed an improvement in sleep onset latency, night wakings, early morning waking and unwanted bed-sharing for 7/7, 6/7, 3/3 and 3/3 children respectively. Improvement was observed for most participants following the less restrictive phases of intervention (circadian modifications, antecedent modifications and positive reinforcement), however, more restrictive, albeit modified, extinction procedures were still implemented for five participants. Improvements were maintained at follow-up and interventions were deemed acceptable to parents.

Conclusions

Less restrictive function-based behavioral strategies are an effective, and in some cases sufficient, contribution to a sequence of interventions for a range of sleep difficulties. They should be implemented first, before more restrictive strategies.
To Evaluate the Age–Happiness Relationship, Look Beyond Statistical Significance
Authors: Bartram David
Published: February 2024

The persistent contentiousness of research on the age–happiness relationship is puzzling; it should be possible to gain clarity and consensus about how to address the question effectively. In this paper I show that a key reason for the lack of clarity consists of overreliance on statistical significance as a means of evaluating empirical results. The statistical significance of a quadratic specification (age plus age-squared) is often taken as evidence in support of a ‘u-shaped’ relationship between age and happiness. But statistical significance on its own cannot tell us whether the age–happiness relationship is ‘u-shaped’ (nor indeed whether it takes any other shape). On the contrary, statistical significance can mislead us about it: a set of quadratic age coefficients can be ‘significant’ even when the relationship is obviously characterised by a different shape. When we have clarity on how to construct the analysis so that we can ‘see’ the underlying patterns in the data, it becomes obvious that the age–happiness relationship in European countries commonly shows other patterns; a u-shape is evident only in a minority of countries.
Analysis of nonsynonymous SNPs in candidate genes that influence bovine temperament and evaluation of their effect in Brahman cattle
Authors: Ruiz-De-La-Cruz Gilberto , Sifuentes-Rincón Ana María , Paredes-Sánchez Francisco Alejandro , Parra-Bracamonte Gaspar Manuel , Casas Eduardo , Riley David G. , Perry George A. , Welsh Thomas H. , Randel Ronald D.
Published: February 2024

Background

Temperament is an important production trait in cattle and multiple strategies had been developed to generate molecular markers to assist animal selection. As nonsynonymous single nucleotide polymorphisms are markers with the potential to affect gene functions, they could be useful to predict phenotypic effects. Genetic selection of less stress-responsive, temperamental animals is desirable from an economic and welfare point of view.

Methods and results

Two nonsynonymous single nucleotide polymorphisms identified in HTR1B and SLC18A2 candidate genes for temperament were analyzed in silico to determine their effects on protein structure. Those nsSNPs allowing changes in proteins were selected for a temperament association analysis in a Brahman population. Transversion effects on protein structure were evaluated in silico for each amino acid change model, revealing structural changes in the proteins of the HTR1B and SLC18A2 genes. The selected nsSNPs were genotyped in a Brahman population (n = 138), and their genotypic effects on three temperament traits were analyzed: exit velocity, pen score, and temperament score. Only the SNP rs209984404-HTR1B (C/A) showed a significant association (P = 0.0144) with pen score. The heterozygous genotype showed a pen score value 1.17 points lower than that of the homozygous CC genotype.

Conclusion

The results showed that in silico analysis could direct the selection of nsSNPs with the potential to change the protein. Non-synonymous single nucleotide polymorphisms causing structural changes and reduced protein stability were identified. Only rs209984404-HTR1B shows that the allele affecting protein stability was associated with the genotype linked to docility in cattle.
Converging survival trends in non-small cell lung cancer patients with and without brain metastasis receiving state-of-the-art treatment
Authors: Averbuch Itamar , Tschernichovsky Roi , Yust-Katz Shlomit , Rotem Ofer , Limon Dror , Kurman Noga , Icht Oded , Reinhorn Daniel , Moskovitz Mor , Hanovich Ekaterina , Benouaich-Amiel Alexandra , Siegal Tali , Zer Alona , Gal Omer
Published: February 2024

Introduction

Historically, patients with brain metastasis (BM) have been excluded from clinical trials investigating treatments for non-small cell lung cancer (NSCLC) due to their unfavorable prognosis. Advanced treatments have increased survival prospects for NSCLC patients with BM. This study evaluated the life expectancy of NSCLC patients with and without BM in the context of contemporary treatments.

Methods

Outcome data were collected for patients with advanced NSCLC attending a tertiary medical center between 2015 and 2020. Patients were stratified according to BM status and compared for overall survival (OS) using log-rank and Cox regression analyses.

Results

The cohort included 360 patients with NSCLC of whom 134 (37.2%) had BM. Most (95%) of cases of BM developed within the first two years: 63% at diagnosis, 18% during the first year, 14% during the second year. There was no significant difference in OS between patients without BM and those with BM (median 23.7 vs. 22.3 months, HR = 0.97, p = 0.82); patients with BM and a targetable or non-targetable mutation (40.2 vs. 31.4 months, HR = 0.93, p = 0.84, and 20.7 vs. 19.87 months, HR = 0.95, p = 0.75, respectively); and patients with symptomatic BM (23.7 vs. 19.8 months, HR = 0.95, p = 0.78). Treatment for BM (95% of patients) consisted of stereotactic radiosurgery or tyrosine kinase inhibitors, with corresponding intracranial control rates of 90% and 86%.

Conclusion

The results imply that the presence of BM has no impact on the prognosis of NSCLC. The practice of excluding NSCLC patients with BM from clinical trials warrants reconsideration.
DCLGM: Fusion Recommendation Model Based on LightGBM and Deep Learning
Authors: Zhao Bin , Li Bin , Zhang Jiqun , Cao Wei , Gao Yilong
Published: February 2024

The recommendation system can mine valuable information according to user preferences, so it is widely used in various industries. However, the performance of recommendation systems is generally affected by the problem of data sparsity, and LightGBM can alleviate the impact caused by data sparsity to a certain extent. To this end, this paper proposes a fusion recommendation model based on the LightGBM and deep learning—CLGM model. The model is composed of LighGBM, cross network and deep neural network. First, the features in the dataset are fused and extracted through LightGBM, and the feature with the highest classification accuracy is selected as the input of the neural network layer; Then, using the cross network and the deep neural network, the linear cross combination feature relationship and nonlinear correlation relationship between high-order features are respectively obtained; finally, the results obtained by the pre-order network are linearly weighted and combined to obtain the final recommendation result. In this paper, AUC and Logloss are used as evaluation indicators to verify the model on the public dataset Criteo and dataset Avazu. The simulation experiment results show that, compared with the four typical recommendation models, the recommendation effect of this model is better.
Projective Synchronization of Inertial Quaternion-Valued Neural Networks via Non-reduced Order Approach
Authors: Huang Qun , Yu Yue , Cao Jinde
Published: February 2024

In this article, the issue on projective synchronization of delayed inertial quaternion-valued neural networks (IQVNNs) is investigated. Different from most existing literature, we adopt the non-reduced order approach to deal with IQVNNs described by second order differential equations. By introducing a novel Lyapunov functional, several sufficient criteria are presented in component form to ensure the projective synchronization between master–slave systems. A numerical experiment demonstrates the feasibility of control strategy as well as the correctness of theoretical results.
A reliable data-based smoothing parameter selection method for circular kernel estimation
Authors: Ameijeiras-Alonso Jose
Published: February 2024

A new data-based smoothing parameter for circular kernel density (and its derivatives) estimation is proposed. Following the plug-in ideas, unknown quantities on an optimal smoothing parameter are replaced by suitable estimates. This paper provides a circular version of the well-known Sheather and Jones bandwidths (J R Stat Soc Ser B Stat Methodol 53(3):683–690, 1991. https://doi.org/10.1111/j.2517-6161.1991.tb01857.x), with direct and solve-the-equation plug-in rules. Theoretical support for our developments, related to the asymptotic mean squared error of the estimator of the density, its derivatives, and its functionals, for circular data, are provided. The proposed selectors are compared with previous data-based smoothing parameters for circular kernel density estimation. This paper also contributes to the study of the optimal kernel for circular data. An illustration of the proposed plug-in rules is also shown using real data on the time of car accidents.
Unique Identification of Stiffness Parameters in Hyperelastic Models for Anisotropic, Deformable, Thin Materials Based on a Single Experiment - A Feasibility Study Based on Virtual Full-Field Data
Authors: Makhool L. , Balzani D.
Published: February 2024

Background

Characterizing material properties of thin sheets for design or manufacturing purposes is an essential concern in many engineering applications. This task is particularly challenging for materials with a pronounced anisotropic and nonlinear mechanical behavior.

Objective

A hybrid, experimental-numerical approach for the characterization of the mechanical, nonlinear response of thin, anisotropic, deformable materials is proposed. In contrast to classical approaches where various biaxial tension tests are analyzed, the main goal here is the complete characterization based on one single experiment.

Methods

The proposed approach is based on a novel non-standard experimental setup which is on the one hand easy to install and use, and which on the other hand intentionally induces a strongly inhomogeneous strain field in the specimen capturing as many deformation modes and intensities as possible. The resulting displacement field can be measured using e.g., digital image correlation, and is then accessible to the parameter identification as full-field data. To allow for an efficient identification, an extended equilibrium gap method is presented, where unknown boundary force distributions applied in the experiment are computed iteratively. The approach’s feasibility is assessed through virtual full-field data obtained by numerical simulation of the proposed experimental setup using predefined parameter values and applying realistic noise. That way, a quantitative assessment of the method’s performance regarding two specifically chosen material models is enabled.

Results

Provided that the stiffness-related material parameters are indeed linear in the stress equations, a quadratic optimization problem can be constructed to allow for a unique identification of the parameter values. Analysis show that reference parameter values for calendered rubber as well as coated textile fabric can be identified, even when realistic noise is applied to the virtual test data.

Conclusion

Based on the presented investigations, the proposed method has been found to be feasible for the accurate identification of stiffness-related parameters of anisotropic, nonlinear thin sheets using a single experiment.
Spent coffee grounds as a suitable alternative to standard soil in ecotoxicological tests
Authors: Mendes Luís André , Domínguez Jorge
Published: February 2024

Eisenia andrei is considered in OECD and ISO guidelines to be a suitable replacement for Eisenia fetida in ecotoxicological assays. This suggests that other alternative materials and methods could also be used in standard procedures for toxicity testing. The guidelines also favor using less time-consuming procedures and reducing costs and other limitations to ecotoxicological assessments. In recent years, spent coffee grounds (SCG) have been used to produce vermicompost and biochar and as an additive to organic fertilizers. In addition, the physicochemical characteristics of SCG indicate that the material is a suitable substrate for earthworms, with the organisms performing as well as in natural soil. In the present study, a battery of ecotoxicological tests was established with unwashed and washed SCG and a natural reference soil (LUFA 2.2). The test substrates were spiked with different concentrations of silver nitrate. Survival and reproduction of the earthworm E. andrei were assessed under different conditions, along with substrate basal respiration (SBR) as a proxy for microbial activity. Seedling emergence and the germination index of Lepidium sativum were also determined, following standard guidelines. Exposure to silver nitrate had similar effects on earthworm survival and reproduction, as the estimated effective concentrations (EC10 and EC50) in unwashed SCG and LUFA 2.2 overlapped. A hormetic effect was observed for SBR in LUFA 2.2 spiked with 12.8 mg/kg but not in unwashed SCG. Both SBR and root development were inhibited by similar concentrations of silver nitrate in washed SCG. The findings indicate that unwashed SCG could potentially be used as a substrate in E. andrei toxicity tests and support the eventual inclusion of this material in the standard guidelines.
Harmfulness and Wrongfulness in Sex-by-Deception
Authors: Tolley Rachel C.
Published: February 2024

In Criminalizing Sex, Stuart Green wisely eschews any attempt to fully analyse the problem of ‘sex-by-deception’ in a single chapter, instead offering a ‘basic framework’ for determining whether an expansion of the law of ‘rape by deceit’ might be justified. In this article, I offer a revision to that framework. Green begins from an account of rape centred on the right to (negative) sexual autonomy and seeks to reject an expansionist account under which any deceptions and mistakes could vitiate consent to sexual activity. Sharing these starting points, I argue, pace Green, that variations in the harmfulness and wrongfulness of different deceptions cannot ground content-based restrictions on consent-vitiating deceptions. I argue that whilst different kinds of deceptive practices might wrong V to a greater or lesser extent, these variations lead to content-neutral, form-based restrictions on consent-vitiating deceptions. Moreover, whilst variations in the harms of D’s conduct are unlikely to ground a coherent set of content-sensitive restrictions on consent-vitiating deceptions, the harms of criminalisation differ depending on the content of the deception in question and this might lead to content-based restrictions on liability. However, an analysis of the variable costs of criminalisation is not obviously connected to the moral concept of consent-validity. Accordingly, whilst I suspect that both form and content-based restrictions on consent-vitiating deceptions are warranted in this area, the justification for the latter is unlikely to lie within an analysis of consent-validity itself, or the varied harmfulness and wrongfulness of D’s own conduct.
An online clinical decision tool to screen for vertebral fragility fractures (Vfrac) in older women presenting with back pain in general practice: protocol for a feasibility study in preparation for a future cluster randomised controlled trial
Authors: Khalid Tanzeela Y. , Peters Tim J. , Pocock Lucy V. , Drew Sarah , Hardcastle Sarah A. , Paskins Zoe , Davis Sarah , Kariki Eleni P. , Clark Emma M.
Published: February 2024

This feasibility study for a future definitive randomized trial assesses the use and acceptability of a new clinical decision tool to identify risk of a vertebral fracture and those who should be referred for spinal radiography in women aged 65 or over presenting to primary care with back pain.

Purpose

Approximately 12% of older adults have vertebral fragility fractures, but currently fewer than one-third are diagnosed, potentially limiting access to bone protection treatment. Vfrac is a vertebral fracture screening tool which classifies individuals into high or low risk of having a vertebral fracture, allowing targeting of spinal radiographs to high-risk individuals. The objective of this study was to investigate the feasibility of conducting a cluster randomized controlled trial to evaluate the use of an online version of Vfrac in primary care.

Methods

The study will run in six general practices, with three given the Vfrac tool for use on older women (> 65 years) consulting with back pain and three using standard clinical processes for managing such back pain. Anonymised data covering a 12-month period will be collected from all sites on consultations by older women with back pain. Focus groups will be undertaken with healthcare professionals and patients on whom the tool was used to understand the acceptability of Vfrac and identify factors that impact its use. These patients will be sent a paper version of the Vfrac questionnaire to self-complete at home. Outputs of the self-completion Vfrac (high versus low risk) will be compared with the face-to-face Vfrac (high versus low risk), and agreement assessed using Cohen’s kappa.

Results

This study will evaluate the use and acceptability of Vfrac within primary care and determine if data on resource use can be collected accurately and comprehensively.

Conclusions

This article describes the protocol of the Vfrac feasibility study.

Trial registration

ISRCTN18000119 (registered 01/03/2022) and ISRCTN12150779 (registered 10/01/2022).
Two Sides of a Coin: Digital Economy and the Supply of Basic Public Services
Authors: Tian Jinfang , Wang Yunjing , Sun Siyang
Published: February 2024

With the development of a new generation of IT, digital economy bears a far-reaching impact on governmental behavior and effect of governing. There are two main research purposes of this paper: First, it aims to study the relationship between the digital economy and the supply of basic public services. The second purpose is to clarify the transmission mechanism through which the digital economy affects the supply of basic public services. This paper gives an examination of the association of digital economy with the supply of basic public services based on the panel data collected from 287 prefecture-level cities across China from 2011 to 2021 and by utilizing bidirectional fixed effect model. The study delivers findings as follows: There is an inverted “U”-shaped relationship between digital economy and the supply of basic public services and most of the cities situate at the left-hand side of the inflection point. Market enabling and financial enabling serve as the transmission channel through which digital economy affects the supply of basic public services. In non-central cities and areas where energy consumption is high, development of digital economy and the supply of basic public services remain effective in promotion in the first place and inhibition afterwards. A further study shows that there is a non-linear relationship, namely, digital economy plays a role in promoting in the first place and inhibiting afterwards in basic public services such as employment services, social security, and health care. The study’s findings stated hereinafter serve as a reference as to precise formulation of basic public services in the digital and intelligent era, as well as facilitating with sustainable growth.
Comparing stapler and sutured mesh fixation techniques for laparoscopic TAPP repair: a study on chronic groin pain on 3-year follow-up
Authors: Elhadidi Amro , Negm Ahmed , Shouma Ashraf
Published: February 2024

Trans-abdominal preperitoneal (TAPP) and totally extraperitoneal (TEP) repairs are the available surgeries for inguinal hernias, with both methods of laparoscopic repairs requiring mesh applications. This study analyzes the correlation between sutured versus stapler mesh fixation in a laparoscopic TAPP for unilateral groin hernia regarding chronic pain during 3-year follow-up. A total of 130 patients with laparoscopic hernia undergoing TAPP repair were randomized into 2 groups based on their fixation technique—one with sutures and the other with stapler. Postoperative complications and chronic groin pain were noted for each technique. Equal number of participants was present in the stapler and suture groups, with the majority having an ASA score of one. The mean age was 42.50 ± 13.86 years, and the body mass index (BMI) was 27.47 ± 5.88. The stapler group presented a shorter mean operative time than the suture group. However, the stapler group had a significantly higher mean VAS score than the suture group. Most participants in the suture group (89.2%) had LOS for 1 day, while a 2-day LOS was significantly higher in the stapler group (12.3%) than in the suture group (9.2%). No patient reported mesh erosion, conversion, recurrence, testicular atrophy, and mesh infection. Early postoperative pain was more in stapler group along with long hospital stay, but both were non-significant. Chronic postoperative pain results and recurrence incidences over 3-year follow-up were also similar. Re-admission rates were minimal, no significant complications occurred.
Acetyl-cholinesterase-inhibitors reconsidered. A narrative review of post-marketing studies on Alzheimer’s disease
Authors: Zuliani Giovanni , Zuin Marco , Romagnoli Tommaso , Polastri Michele , Cervellati Carlo , Brombo Gloria
Published: February 2024

The real efficacy of Acetyl-cholinesterase-inhibitors (AChEI) has been questioned. In this narrative review we evaluated their effect on cognitive decline, measured by Mini Mental State Examination (MMSE), and on total mortality rates in patients with Alzheimer’s disease (AD) recruited into post-marketing open/non-randomized/retrospective studies. In AD patients treated with AChEI, the mean MMSE loss ranged from 0.2 to 1.37 points/years, compared with 1.07–3.4 points/years in non-treated patients. Six studies also reported data about survival; a reduction in total mortality relative risk between 27% and 42% was observed, over a period of 2–8 years. The type of studies and the use of MMSE to assess cognitive decline, may have introduced several biases. However, the clinical effects of AChEI seem to be of the same order of magnitude as the drugs currently used in most common chronic disorders, as regards progression of the disease and total mortality. In the absence of long-term randomized trials on “standard” unselected AD outpatients, open/retrospective studies and health databases represent the best available evidence on the possible effect of AChEI in the real-word setting. Our data support the clinical benefit of AChEI in older patients affected by AD.
Multiphase simulations of nonlinear fluids with SPH
Authors: Monge-Gapper Juan Gabriel , Calderon-Sanchez Javier , Serrano-Pacheco Alberto
Published: February 2024

A modified apparent viscosity approach has been implemented for a weakly compressible SPH scheme for two-phase flows where a nonlinear phase must yield under erosive dynamics but also maintain a pseudosolid behaviour under the right conditions. The final purpose is to provide a means to model both dam-break dynamics and erosive interactions between different phases simultaneously while also keeping smooth pressure fields in spite of discontinuities introduced by viscosity variations of a nonlinear phase along with significant differences in mean density. Key contributions include purposeful avoidance of nonphysical elastic behaviour and the integration of a specific particle shifting technique that allows for proper replication of erosion and scouring. In this work, the method is validated by applying it to model a silted-up dam that collapses over a static water bed, effectively including all main elements of interest. Although the formulation is inherently three dimensional, validation is done by direct comparison with data from physical experiments of a dominant two-dimensional nature, assuming variable yield stress of medium-grain quartz sand according to the Drucker–Prager equation. Overall results show most of the expected interface dynamics, such as erosion and transportation of the nonlinear phase, sustained piling of the non-yielded volume of silt, and good correspondence of both granular and water surface position with experimental data. Finally, a series of modelling assumptions and implications for future developments are explicitly stated because of their direct impact on stability and versatility for multiphase, nonlinear flows in general.
Research on the prediction of mine water inrush disasters based on multi-factor spatial game reconstruction
Authors: Zheng Qiushuang , Wang Changfeng , Zhu Zhenhao
Published: February 2024

Water damage in mines poses a widespread challenge in the coal mining industry. Gaining a comprehensive understanding of the multi-factor spatial catastrophe evolution mechanism and process of floor water inrush is crucial, which will enable the achievement of dynamic, quantitative, and precise early warning systems. It holds significant theoretical guidance for implementing effective water prevention and control measures in coal mines. This study focuses on the issue of water inrush in the coal seam floor, specifically in the context of Pengzhuang coal mine. By utilizing a small sample of non-linear characteristics derived from drilling geological data, we adopt a multifactor spatial perspective that considers geological structure and hydrogeological conditions. In light of this, we propose a quantitative risk prediction model that integrates the coupled theoretical analysis, statistical analysis, and machine learning simulation methods. Firstly, the utilization of a quantification approach employing a triangular fuzzy number allows for the representation of a comparative matrix based on empirical values. Simultaneously, the networked risk transmission effect of underlying control risk factors is taken into consideration. The application of principal component analysis optimizes the entropy weight method, effectively reducing the interference caused by multifactor correlation. By employing game theory, the subjective and objective weight proportions of the control factors are reasonably allocated, thereby establishing a vulnerability index model based on a comprehensive weighting of subjective and objective factors. Secondly, the WOA-RF-GIS approach is employed to comprehensively explore the interconnectedness of water diversion channel data. Collaborative Kriging interpolation is utilized to enhance the dimensionality of the data and facilitate spatial information processing. Lastly, the representation of risk is coupled with necessary and sufficient condition layers, enabling the qualitative visualization of quantitative results. This approach aims to accurately predict disaster risk with limited sample data, ultimately achieving the goal of precise risk assessment. The research findings demonstrate that the reconstructed optimization model based on multi-factor spatial game theory exhibits high precision and generalization capability. This model effectively unveils the non-linear dynamic processes associated with floor water inrush, which are influenced by multiple factors, characterized by limited data volume, and governed by complex formation mechanisms. The identification of high-risk areas for water inrush is achieved with remarkable accuracy, providing invaluable technical support for the formulation of targeted water prevention and control measures, ultimately ensuring the safety of coal mining operations.
Detection of the longest periodic variability in 6.7 GHz methanol masers with iMet
Authors: Tanabe Yoshihiro , Yonekura Yoshinori
Published: February 2024

Long-term monitoring observations of the 6.7 GHz methanol masers by Hitachi 32-m operated by Ibaraki University, which are named as “the Ibaraki 6.7 GHz Methanol Maser Monitor (iMet)”, have revealed that the periods of the flux variability of 6.7 GHz methanol masers in the five high-mass star-forming regions G05.900-0.430, G06.795-0.257, G10.472+0.027, G12.209-0.102 and G13.657-0.599 are over 1000 days. These periods are approximately twice the longest known period of 6.7 GHz methanol masers of 668 days for G196.45-1.68. The facts that the flux variation patterns show symmetric sine curves and that the luminosity of the central protostar and periods of maser flux variation are consistent with the expected period-luminosity (PL) relation suggest that the mechanism of maser flux variability of G05.900-0.430, G10.472+0.027 and G12.209-0.102 can be explained by protostellar pulsation instability. From the period-luminosity relation, central stars of these three sources are expected to be very high-mass protostars with a mass of : ∼40 M⊚ and a mass accretion rate of : ∼2×10-2M⊚yr-1. On the other hand, G06.795-0.257 and G13.657-0.599 have luminosities that are an order of magnitude smaller than that expected from PL relation, and the variation patterns are intermittent, suggesting a variation mechanism of these sources originated from binary system.
Ultra-precise monitoring of a class I methanol maser
Authors: Voronkov M. A. , Breen S. L. , Ellingsen S. P. , Green J. A. , Sobolev A. M. , Parfenov S. Yu. , van der Walt D. J.
Published: February 2024

We report the results of a 7-year monitoring program using the Australia Telescope Compact Array (ATCA) for the 9.9 GHz class I methanol maser in G331.13-0.24 where a periodic class II methanol maser is present. The great deal of the project was to control systematics at an unprecedented level. Although no periodic flux variation was found, the maser shows a very stable decline of 166±7 μJy/day. The radial velocity of the maser is stable down to 1 m/s level. We also report a marginal periodic signal in radial velocity (comparable to the level of systematics) of about 20±7 cm/s with the period of 475±22 days, close to that of the 6.7-GHz maser in the source. No hyperfine split was detected which suggests preferential excitation of a single hyperfine transition.
Galactic astrometry with Gaia
Authors: Jordi Carme
Published: February 2024

Gaia space mission of the European Space Agency was launched at the end of 2013 and will continue operations until 2025. The published data releases revolutionize the view of the Milky Way galaxy and beyond thanks to its unprecedented astrometry, photometry and spectroscopy. The paper reviews the products of the last data release of the Gaia mission and some of the scientific impacts of the data. We also discuss the future perspectives of Galaxy astrometry from space.
Mapping the Far Side of the Milky Way
Authors: Reid Mark J.
Published: February 2024

Great progress has been made using VLBI techniques to measure trigonometric parallaxes to masers associated with young, high-mass stars, in order to map the spiral structure of the Milky Way. However, large numbers of parallax distance have only been obtained over about half of the Galaxy. Here I discuss the use of 3-dimensional kinematic distances for completing the map with many sources well past the Galactic Center.
Signposts of transitional phases on the Asymptotic Giant Branch
Authors: Etoka S.
Published: February 2024

When low- and intermediate-mass stars pass through the Asymptotic Giant Branch (AGB) they experience dramatic changes in their circumstellar shell (CSE) influenced by their mass loss, the possible presence of a (closeby) companion and the magnetic field. Masers, well spread in this environment, provide a powerful tool to reveal the CSE changes occurring when the stars undergo a transitional phase on the AGB. These can be indirect, via for instance the modification of the pumping conditions or a direct consequence of e.g. a companion and/or of the magnetic field. Evidences of such changes have been observed towards Miras, materialized by strong - both in intensity and degree of polarisation - (OH) flaring events and towards stars believed to be transitioning from the Mira to the OH/IR phase, showing an unusual high degree of polarisation. How OH maser emission can be used as a signpost of transitional phases along the AGB is explored.
Catching unusual phenomena with extensive maser monitoring
Authors: Durjasz Michał
Published: February 2024

High brightness and low interstellar extinction allow the 6.7 GHz methanol (CH3OH) masers to carry the information about what happens in the vicinity of the High-Mass Young Stellar Objects (HMYSOs). Monitoring this transition provides an only one opportunity to catch rare, unusual phenomena. In this paper, I describe three of them: quasi-periodic flares of the red-shifted emission in Cep A HW2, accretion burst in S255-NIRS3 and reappearance of the methanol maser flare in G24.329+0.144.
Searching masers from the Sagittarius stellar stream
Authors: Wu Yuanwei , Zhang Bo , Gong Yan , Yang Wenjin , Mauron Nicolas
Published: February 2024

Large scale optical and infrared surveys have revealed numbers of accretion-derived stellar features within the halo of the Galaxy. These coherent tail-like features are produced by encounters with satellite dwarf galaxies. We conducted an SiO and H2O maser survey towards O-rich AGBs towards the orbital plane of the Sgr Stellar Stream from 2016. Up to now, maser emissions have been found from 60 sources, most of which are detected for the first time. However, their distances and kinematics suggest they are still disk stars.
Supermassive black hole mass growth in infrared-luminous gas-rich galaxy mergers and potential power of (sub)millimeter H2O megamaser observations
Authors: Imanishi Masatoshi
Published: February 2024

We present our systematic infrared and (sub)millimeter spectroscopic observations of gas/dust-rich merging ultraluminous infrared galaxies (ULIRGs) to scrutinize deeply buried AGNs (mass-accreting supermassive black holes [SMBHs]). We have found signatures of optically elusive, but intrinsically luminous buried AGNs in a large fraction of nearby (z < 0.3) ULIRGs, suggesting that SMBH mass growth is ongoing in the ULIRG population. Using ALMA, we have detected compact (<100 pc), very luminous (>104Lʘ), AGN-origin, 183 GHz (1.6 mm) H2O megamaser emission in one merging ULIRG, demonstrating that the megamaser emission can be a very powerful tool to dynamically estimate SMBH masses, with the smallest modeling uncertainty of kpc-wide stellar and gas mass distribution, at dusty ULIRGs’ nuclei, because of minimum extinction effects at millimeter. We present our current results and future prospect for the study of the SMBH mass growth in gas/dust-rich galaxy mergers, using (sub)millimeter AGN-origin H2O megamaser emission lines.
Maser Activity of Large Molecules toward Sgr B2 North
Authors: Xue Ci , Remijan Anthony , Faure Alexandre , McGuire Brett
Published: February 2024

Single-dish observations at centimeter wavelengths have suggested that the Sgr B2 molecular cloud at the Galactic Center hosts weak maser emission from several large molecules. Here, we present the interferometric observations of the Class I methanol (CH3OH) maser at 84 GHz, the methanimine (CH2NH) maser at 5.29 GHz, and the methylamine (CH2NH2) maser at 4.36 GHz toward Sgr B2 North (N). We use a Bayesian approach to quantitatively assess the observed masing spectral profiles and the excitation conditions. By comparing the spatial origin and extent of maser emission from several molecular species, we find that the new maser transitions have a close spatial relationship with the Class I masers, which suggests a similar collisional pumping mechanism.
High resolution ALMA imaging of H2O, and SiO, and SO2 masers in the atmosphere of the AGB star W Hya
Authors: Ohnaka Keiichi , Wong Ka Tat
Published: February 2024

The mass-loss mechanism in asymptotic giant branch (AGB) stars is not yet fully understood. We present 20-milliarcsecond resolution ALMA imaging of the well-studied AGB star W Hya in multiple molecular lines at 250–269 GHz, including masers from SiO, H2O, and SO2. The images show complex plumes, arcs, and clumps over the stellar disk and in the atmosphere extending to several stellar radii. We detected prominent emission components over the stellar disk—instead of pure absorption as expected—in some Si17O, 30SiO, H2O, and SO2 lines. The surface emission seen in the Si17O and vibrationally excited H2O lines is particularly strong, indicating maser actions. The masers seen over the stellar disk indicate radial amplification.
Variability, flaring and coherence – the complementarity of the maser and superradiance regimes
Authors: Houde Martin , Rajabi Fereshteh , MacLeod Gordon C. , Goedhart Sharmila , Tanabe Yoshihiro , van den Heever Stefanus P. , Wyenberg Christopher M. , Yonekura Yoshinori
Published: February 2024

We discuss the role that coherence phenomena can have on the intensity variability of spectral lines associated with maser radiation. We do so by introducing the fundamental cooperative radiation phenomenon of (Dicke’s) superradiance and discuss its complementary nature to the maser action, as well as its role in the flaring behaviour of some maser sources. We will consider examples of observational diagnostics that can help discriminate between the two, and identify superradiance as the source of the latter. More precisely, we show how superradiance readily accounts for the different time-scales observed in the multi-wavelength monitoring of the periodic flaring in G9.62+0.20E.
Mass Loss in Evolved Stars
Authors: Matthews Lynn D.
Published: February 2024

Intense mass loss through cool, low-velocity winds is a defining characteristic of low-to-intermediate mass stars during the asymptotic giant branch (AGB) evolutionary stage. Such winds return up ∼80% of the initial stellar mass to the interstellar medium and play a major role in enriching it with dust and heavy elements. A challenge to understanding the physics underlying AGB mass loss is its dependence on an interplay between complex and highly dynamic processes, including pulsations, convective flows, shocks, magnetic fields, and opacity changes resulting from dust and molecule formation. I highlight some examples of recent advances in our understanding of late-stage stellar mass loss that are emerging from radio and (sub)millimeter observations, with a particular focus on those that resolve the surfaces and extended atmospheres of evolved stars in space, time, and frequency.
Multi-scale observational study of G45.804-0.355 star-forming region
Authors: Seidu M. , Chibueze J. O. , Fuller G. A. , Avison A. , Frimpong N. A
Published: February 2024

This is a multi-wavelength study to examine the G45.804-0.355 massive star-forming region (SFR) and its environs. Using MeerKAT with angular resolution (θ) of 8″ at 1.28 GHz, we identify for the first time, a faint radio continuum emission core in G45.804-0.355. At 1.3 mm, ALMA observations (θ∼0″ 7) resolved the core into multiple dust continuum condensations including MM1 which was found to be the primary massive dust dense core in the region (mass Mc∼ 54.3M⊙). The dust continuum shows an arm-like extended emission within which other dense cores are situated. The velocity gradient of the MM1 core indicates that the source is associated with a rotation gas motion. The red- and blue-shifted lobes overlap at the position of MM1. The compact morphology of the 4.5 μm IR emission, the presence of spiral arms and overlapping of the red- and blue-shifted lobes suggest a face-on geometry of G45.80-40.355.
The 40-m Thai National Radio Telescope with its key sciences and a future South-East Asian VLBI Network
Authors: Sugiyama Koichiro , Jaroenjittichai Phrudth , Leckngam Apichat , Kramer Busaba H. , Rujopakarn Wiphu , Soonthornthum Boonrucksar , Sakai Nobuyuki , Punyawarin Songklod , Duangrit Nattapong , Asanok Kitiyanee , Hidayat Taufiq , Abidin Zamri Zainal , Algaba Juan Carlos , Diep Pham Ngoc , Poshyachinda Saran
Published: February 2024

National Astronomical Research Institute of Thailand (Public Organization) initiated a national flagship project in 2017 for development of radio astronomy and geodesy in Thailand. In this project, a 40-m Thai National Radio Telescope (TNRT) and a 13-m VLBI Global Observing System (VGOS) radio telescope as its co-location are constructed in Chiang Mai. The 40-m TNRT is the largest telescope for radio astronomy in South-East Asia. Its flexible operation with a wide-coverage of observable frequencies 0.3-115 GHz will allow us to uniquely contribute to the time-domain astronomy as well as carry out unbiased surveys for a wide variety of science research fields, which were published in a white paper. Within the framework of collaboration with VLBI arrays in the world, TNRT will drastically improve the imaging quality and performances based on its unique geographical location, for both radio astronomy and geodetic VLBI studies in South-East Asia for the first time. On-going commissioning of TNRT particularly in the L-band system (1.0–1.8 GHz) is introduced as well as vision for establishment of forthcoming regional VLBI networks based on TNRT: Thai National VLBI Array and South-East Asian VLBI Network in collaboration with Indonesia, Malaysia, and Vietnam.
Astrometry of Water Maser sources in the Outer Galaxy with VERA
Authors: Nakanishi Hiroyuki , Sakai Nobuyuki , Kurahara Kohei ,   VERA Outer Rotation Curve project members
Published: February 2024

While the rotation curve of the inner Galactic disk is well determined, study of the outer rotation curve requires observational measurements of distances and proper motions of individual sources in the Outer Galaxy. We report astrometric observation for water maser sources in the Outer Galactic disk conducted with VERA, aiming to measure the Outer Rotation Curve. We have measured annual parallaxes and proper motions for these objects. Our result was consistent with recent other works based on astrometry and classical Cepheid observations. Epicyclic frequency seems to suggest that 2 and 4 spiral mode are dominant in the inner and outer Galaxy, respectively.
Spatio-kinematics of water masers in the HMSFR NGC6334I before and during an accretion burst
Authors: Vorster Jakobus M. , Chibueze James O. , Hirota Tomoya , MacLeod Gordon C.
Published: February 2024

In 2015, the high-mass star-forming region NGC6334I-MM1 underwent an accretion burst. Using VERA, we monitored 22 GHz water masers before and during the accretion burst to observe the changes in the maser spatial and velocity distributions in the region. The masers in CM2-W2 and MM1-W1 displayed variability that could be attributed to the accretion burst. The bright masers in CM2-W2 were found to better trace the shock structure as the epochs progressed. The mean 3D speeds derived from the proper motions were 50 km/s and 54 km/s for the pre-burst and burst epochs respectively. High-velocity proper motions were found at the southern edges of the N-S (∼80 km s−1) and NW-SE (∼150 km s−1) bipolar outflows. The precise mechanism of the flaring of the water masers due to the accretion burst has yet to be investigated.