bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross-sectional study of the burden and determinants of non-medical and opportunity costs of accessing chronic disease care in rural Tanzania
Authors: Verjans Anna , Hooley Brady , Tani Kassimu , Mhalu Grace , Tediosi Fabrizio
Published: March 2024

Objectives

Countries in sub-Saharan Africa are seeking to improve access to healthcare through health insurance. However, patients still bear non-medical costs and opportunity costs in terms of lost work days. The burden of these costs is particularly high for people with chronic diseases (CDs) who require regular healthcare. This study quantified the non-medical and opportunity costs faced by patients with CD in Tanzania and identified factors that drive these costs.

Methods

From November 2020 to January 2021, we conducted a cross-sectional patient survey at 35 healthcare facilities in rural Tanzania. Using the human capital approach to value the non-medical cost of seeking healthcare, we employed multilevel linear regression to analyse the impact of CDs and health insurance on non-medical costs and negative binomial regression to investigate the factors associated with opportunity costs of illness among patients with CDs.

Results

Among 1748 patients surveyed, 534 had at least one CD, 20% of which had comorbidities. Patients with CDs incurred significantly higher non-medical costs than other patients, with an average of US$2.79 (SD: 3.36) compared with US$2.03 (SD: 2.82). In addition, they incur a monthly illness-related opportunity cost of US$10.19 (US$0–59.34). Factors associated with higher non-medical costs included multimorbidities, hypertension, health insurance and seeking care at hospitals rather than other facilities. Patients seeking hypertension care at hospitals experienced 35% higher costs compared with those visiting other facilities. Additionally, patients with comorbidities, older age, less education and those requiring medication more frequently lost workdays.

Conclusion

Outpatient care in Tanzania imposes considerable non-medical costs, particularly for people with CDs, besides illness-related opportunity costs. Despite having health insurance, patients with CDs who seek outpatient care in hospitals face higher financial burdens than other patients. Policies to improve the availability and quality of CD care in dispensaries and health centres could reduce these costs.
Prognostic impact of combined non-severe aortic stenosis and mitral regurgitation on clinical outcomes: a single-centre retrospective study
Authors: Granot Yoav , Sapir Orly Ran , Laufer-Perl Michal , Viskin Dana , Banai Shmuel , Topilsky Yan , Havakuk Ofer
Published: March 2024

Objectives

Though the concomitant occurrence of non-severe aortic stenosis (AS) and mitral regurgitation (MR) is highly prevalent, there are limited data to guide clinical decision-making in this condition. Here, we attempt to determine an aortic valve area (AVA) cut-off value associated with worse clinical outcomes in patients with combined non-severe AS and MR.

Methods

Single-centre, retrospective analysis of consecutive patients who underwent echocardiography examination between 2010 and 2021 with evidence of combined non-severe AS and MR. We excluded patients with ≥moderate aortic valve regurgitation or mitral stenosis, as well as patients who underwent any aortic or mitral intervention either prior or following our assessment (n=372).

Results

The final cohort consisted of 2933 patients with non-severe AS, 506 of them with >mild MR. Patients with both pathologies had lower cardiac output and worse diastolic function.

Patients with an AVA ≤1.35 cm² in the presence of >mild MR had the highest rates of heart failure (HF) hospitalisations (HR 3.1, IQR 2.4–4, p<0.001) or mortality (HR 2, IQR 1.8–2.4, p<0.001), which remained significant after adjusting for clinical and echocardiographic parameters.

Conclusion

Patients with combined non-severe AS and MR have a higher rate of HF hospitalisations and mortality. An AVA≤1.35 cm² in the presence of >mild MR is associated with worse clinical outcomes.
Mixed-methods feasibility outcomes for a novel ACT-based video game ‘ACTing Minds’ to support mental health
Authors: Gordon Tom C , Kemp Andrew H , Edwards Darren J
Published: March 2024

Objectives

To determine the feasibility and acceptability of ‘ACTing Minds’, a novel single-player adventure video game based on acceptance and commitment therapy (ACT).

Design

A single-arm, mixed-methods repeated measures feasibility study.

Setting

Intervention and questionnaires were completed at home by participants. Semistructured interviews were also conducted at home via the Zoom platform.

Participants

Thirty-six participants were recruited into the study, 29 completed all phases of the feasibility design. Eligibility criteria required participants to be over the age of 18 and self-reporting experiencing ongoing depression, anxiety or stress.

Intervention

Participants completed a single session of the ‘ACTing Minds’ video game, lasting approximately 1 hour, designed to educate users on key principles from ACT.

Primary outcome measures

Participant recruitment and retention, questionnaire completion, long-term intervention adherence and acceptability of the intervention. Reflexive thematic analysis was conducted on semistructured interviews run immediately postintervention and 3 weeks later.

Secondary outcome measures

Measures of depression, anxiety, stress, psychological flexibility, social connectedness and well-being were assessed at baseline, immediately following intervention completion, and after a 3-week follow-up period. We used a standardised battery of questionnaires.

Primary results

Twenty-nine participants completed the study. A reflexive thematic analysis indicated that participants responded positively to the intervention and the study at all stages. Themes reflect participants’ desire for an engaging therapeutic experience, use of game for exploring emotions, as well as their perspectives on how they had applied their learning to the real world.

Secondary results

Quantitative results indicated small to large effect sizes associated with decreases in depression (ηp2 = 0.011), anxiety (ηp2 = 0.096) and stress (ηp2 = 0.108), and increases in psychological flexibility (ηp2 = 0.060), social connectedness (ηp2 = 0.021), well-being (ηp2 = 0.011) and participation in usual activities (ηp2 = .307).

Conclusions

Implementation of the ‘ACTing Minds’ intervention is warranted, based on both qualitative and quantitative outcomes.

Trial registration number

NCT04566042ClinicalTrials.gov
Clinical variables associated with immune checkpoint inhibitor outcomes in patients with metastatic urothelial carcinoma: a multicentre retrospective cohort study
Authors: Labidi Soumaya , Meti Nicholas , Barua Reeta , Li Mengqi , Riromar Jamila , Jiang Di Maria , Fallah-Rad Nazanin , Sridhar Srikala S , Del Rincon Sonia V , Pezo Rossanna C , Ferrario Cristiano , Cheng Susanna , Sacher Adrian G , Rose April A N
Published: March 2024

Objectives

Immune checkpoint inhibitors (ICIs) are indicated for metastatic urothelial cancer (mUC), but predictive and prognostic factors are lacking. We investigated clinical variables associated with ICI outcomes.

Methods

We performed a multicentre retrospective cohort study of 135 patients who received ICI for mUC, 2016–2021, at three Canadian centres. Clinical characteristics, body mass index (BMI), metastatic sites, neutrophil-to-lymphocyte ratio (NLR), response and survival were abstracted from chart review.

Results

We identified 135 patients and 62% had received ICI as a second-line or later treatment for mUC. A BMI ≥25 was significantly correlated to a higher overall response rate (ORR) (45.4% vs 16.3%, p value=0.020). Patients with BMI ≥30 experienced longer median overall survival (OS) of 24.8 vs 14.4 for 25≤BMI<30 and 8.5 months for BMI <25 (p value=0.012). The ORR was lower in the presence of bone metastases (16% vs 41%, p value=0.006) and liver metastases (16% vs 39%, p value=0.013). Metastatic lymph nodes were correlated with higher ORR (40% vs 20%, p value=0.032). The median OS for bone metastases was 7.3 versus 18 months (p value <0.001). Patients with liver metastases had a median OS of 8.6 versus 15 months (p value=0.006). No difference for lymph nodes metastases (13.5 vs 12.7 months, p value=0.175) was found. NLR ≥4 had worse OS (8.2 vs 17.7 months, p value=0.0001). In multivariate analysis, BMI ≥30, bone metastases, NLR ≥4, performance status ≥2 and line of ICI ≥2 were independent factors for OS.

Conclusions

Our data identified BMI and bone metastases as novel clinical biomarkers that were independently associated with ICI outcomes in mUC. External and prospective validation are warranted.
Hyperbaric oxygen therapy for poststroke insomnia: a systematic review and meta-analysis protocol
Authors: Shi Rui , Meng Wenyi , Liu Zhaozheng , Chang Liping , Lu Ruozhu , Chen Xingyu , Xue Wen , Deng Yue
Published: March 2024

Introduction

Insomnia stands as a frequent consequence of a cerebrovascular event, afflicting a substantial fraction of those who endure the aftermath of stroke. The ramifications of insomnia following a stroke can further exacerbate cognitive and behavioural anomalies while hindering the process of neurological convalescence. While several randomised controlled trials (RCTs) have scrutinised the effects of hyperbaric oxygen therapy (HBOT) on poststroke insomnia, the advantages and drawbacks persist in a state of ambiguity. We advocate for a systematic review and meta-analysis of randomised clinical trials to comprehensively evaluate the effectiveness and safety of HBOT in the context of poststroke insomnia.

Methods and analysis

A systematic search will be conducted from nine major databases (PubMed, Web of Science, EMBASE, VIP Information Database, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, China Biomedical Literature Database and Wanfang Database, Physiotherapy Evidence Database (PEDro)) for HBOT for poststroke insomnia of RCTs. The search procedures will adhere to a rigorous approach, commencing from the inception date of each database and continuing until 1 November 2023, with inquiries conducted exclusively in English and Chinese. The primary outcome will focus on the alteration in the quality of sleep while secondary outcomes will encompass the evaluation of adverse events and the rate of reoccurrence. The process of selecting studies, extracting data and evaluating the quality of research will be carried out independently by two reviewers. The quality of the included literature will be assessed using the tools of the Cochrane Collaboration. Meta-analysis will be performed by using RevMan V.5.4 and STATA V.16.0.b software. Finally, the quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation method.

Ethics and dissemination

As all data are derived from published investigations via databases without direct patient contact, ethical approval is obviated in this study. The scientific studies will be published in professional academic publications.

PROSPERO registration number

CRD42023468442.
Maternal outcomes of pre-eclampsia with severe features and its determinants at Abebech Gobena Mothers and Childrens Health and Saint Peter’s Specialized Hospital, Addis Ababa, Ethiopia: a cross-sectional study
Authors: Tadese Mesfin , Damesa Wogene Asefa , Solomon Gebeyehu Shumet , Wakie Getu Engida , Tessema Saba Desta , Endale Agizew
Published: March 2024

Objective

The main objective of this study was to determine the prevalence and factors associated with unfavourable maternal outcomes among pregnant women with pre-eclampsia with severity features (PEWSF) at Abebech Gobena Maternal and Children’s Health and St. Peter’s Hospital, Addis Ababa, Ethiopia, 2023.

Design

A hospital-based cross-sectional study was conducted from 1 January 2023 to July 2023. The data was collected using a structured and pre-tested questionnaire through face-to-face interviews and a review clinical chart. Data was entered using EpiData V.4.6 and analysed using SPSS V.26.0 statistical software. Binary logistic regression analysis was run to identify predictors of maternal outcome.

Setting

Two hospitals in Addis Ababa, Ethiopia.

Participants

348 pregnant women with PEWSF were included.

Outcome measures

Unfavourable maternal outcome was defined as mothers with PEWSF that develop at least one complication, that is, eclampsia, abruption placenta, Haemolysis, Elevated Liver Enzymes and Low Platelet Count (HELLP) syndrome, acute renal failure, disseminated intravascular coagulation, cardiac failure, stroke, postpartum haemorrhage, pulmonary oedema and death.

Results

The overall prevalence of unfavourable maternal outcomes was 33.9% (N=118) (95% CI=28.7 to 38.8). Abruptio placenta (17.2%), HELLP syndrome (15.5%) and postpartum haemorrhage (13.8%) were common complications that occurred among mothers with PEWSF. Age above 35 years (adjusted OR (AOR) (95% CI)=2.70 (1.31 to 5.59)), rural residence (AOR (95% CI)=1.94 (1.07 to 3.53)), unemployment (AOR (95% CI)=0.35 (0.20 to 0.62)), severe blood pressure on admission (AOR (95% CI)=2.32 (1.03 to 5.19)) and complain of severe headache (AOR (95% CI)=1.91 (1.16 to 3.16)) were significant associates of unfavourable maternal outcomes.

Conclusions

The prevalence of unfavourable maternal outcomes was high compared with other studies in Ethiopia. Maternal age, residence, occupation, blood pressure on admission and severe headache have shown a statistically significant association with unfavourable maternal outcomes. Socioeconomic development and early identification of severe signs and symptoms of pre-eclampsia are needed to reduce unfavourable outcomes.
Assessment of rehabilitation following acute ischaemic stroke in China: a registry-based retrospective observational study
Authors: Yin Zhike , Deng Yongmei , Li Zixiao , Gu Hongqiu , Zhou Qi , Wang Yongjun , Wang Chunjuan
Published: March 2024

Objectives

This study aimed to describe the frequency, determinants and outcomes for assessment of patients who had an acute ischaemic stroke (AIS) for rehabilitation during hospitalisation in China.

Design

A registry-based retrospective observational study.

Study design and settings

Data regarding assessment or rehabilitation were extracted from the Chinese Stroke Center Alliance database from 1 August 2015 to 31 July 2019. Univariate and multivariate analyses were conducted to identify patient and hospital characteristics associated with rehabilitation assessment during acute hospitalisation as well as discharge outcomes.

Study cohort

We included 837 897 patients who had a stroke in this study with patient characteristics, admission location, medical history, hospital characteristics and hospital designation.

Primary and secondary outcome measures

Rehabilitation assessment and discharge outcomes.

Results

Among 837 897 patients who had a stroke admitted to 1473 hospitals, 615 991 (73.5%) underwent rehabilitation assessment. There were significant variations in the rates of rehabilitation assessment across hospitals (IQR 61.3% vs 92.9%). According to multivariate analysis, guideline recommended care delivery was associated with a higher rehabilitation assessment rate, whereas high/low body mass index, ambulation (OR 0.88; 95% CI 0.87 to 0.90), history of stroke (OR 0.94; 95% CI 0.93 to 0.95), coronary heart disease (OR 0.84; 95% CI 0.82 to 0.85) and atrial fibrillation (OR 0.91; 95% CI 0.89 to 0.94) were associated with a lower rate. Additionally, rehabilitation assessment during hospitalisation was significantly associated with lower in-hospital mortality (OR 0.38; 95% CI 0.35 to 0.41) and a higher probability of discharge to a rehabilitation centre (OR 2.66; 95% CI 2.5 to 2.82).

Conclusions

Nearly one-quarter of patients who had an AIS do not undergo documented rehabilitation assessment and compliance across hospitals varies. Thus, it is necessary to improve adherence to rehabilitation assessment to improve the quality of medical care for patients who had an AIS.
Understanding the inclusion and participation of adults from Black African Diaspora Communities (BAFDC) in health and care research in the UK: a realist review protocol
Authors: Hoverd Eleanor , Effiom Violet , Gravesande Dionne , Hollowood Lorna , Kelly Tony , Mukuka Esther , Owatemi Taiwo , Sargeant Ify , Ward Shane , Spencer Rachel , Edge Dawn , Dale Jeremy , Staniszewska Sophie
Published: March 2024

Introduction

People from Black African Diaspora Communities (BAFDC) experience poorer health outcomes, have many long-term conditions and are persistently under-represented in health and care research. There is limited focus on programmes, or interventions that support inclusion and participation of people from BAFDC in research. Through coproduction, this realist review seeks to provide a programme theory explaining what context and mechanisms may be required, to produce outcomes that facilitate inclusion and participation for people from BAFDC in health and care research, in the UK.

Methods and analysis

A group of people from BAFDC with lived and professional experience, representing all levels of the health and care research system, will coproduce a realist review with a team of African-Caribbean, white British and white British of Polish origin health and care researchers. They will follow Pawson’s five steps: (1) shaping the scope of the review; (2) searching for evidence; (3) document selection and appraisal; (4) data extraction and (5) data synthesis. The coproduction group will help to map the current landscape, identifying key issues that may inhibit or facilitate inclusion. Data will be extracted, analysed and synthesised following realist logic analysis, identifying and explaining how context and mechanisms are conceptualised in the literature and the types of contextual factors that exist and impact on inclusion and participation. Findings will be reported in accordance with Realist and Meta-narrative Evidence Synthesis Evolving Standards .

Ethics and dissemination

The coproduction group will agree an ethical approach considering accountability, responsibility and power dynamics, by establishing a terms of reference, taking a reflexive approach and coproducing an ethical framework. Findings will be disseminated to BAFDC and the research community through arts-based methods, peer-reviewed publications and conference presentations, agreeing a coproduced strategy for dissemination. Ethical review is not required.

PROSPERO registration number

CRD42024517124.
Decision to self-isolate during the COVID-19 pandemic in the UK: a rapid scoping review
Authors: Keene Claire Marriott , Dickinson Sophie , Naidoo Reshania , Andersen-Waine Billie , Ferguson-Lewis Angus , Polner Anastasia , Amswych Ma’ayan , White Lisa , Molyneux Sassy , Wanat Marta
Published: March 2024

Objective

Testing for COVID-19 was a key component of the UK’s response to the COVID-19 pandemic. This strategy relied on positive individuals self-isolating to reduce transmission, making isolation the lynchpin in the public health approach. Therefore, we scoped evidence to systematically identify and categorise barriers and facilitators to compliance with self-isolation guidance during the COVID-19 pandemic in the UK, to inform public health strategies in future pandemics.

Design

A rapid scoping review was conducted.

Search strategy

Key terms were used to search literature databases (PubMed, Scopus and the WHO COVID-19 Research Database, on 7 November 2022), Google Scholar and stakeholder-identified manuscripts, ultimately including evidence published in English from UK-based studies conducted between 2020 and 2022.

Data extraction and synthesis

Data were extracted and synthesised into themes, organised broadly into capability, opportunity and motivation, and reviewed with key stakeholders from the UK Health Security Agency (UKHSA).

Results

We included 105 sources, with 63 identified from UKHSA and used to inform their decision-making during the pandemic. Influences on the decision to comply with isolation guidance were categorised into six themes: perceived ability to isolate; information and guidance; logistics; social influences, including trust; perceived value; and perceived consequences. Individuals continuously assessed these factors in deciding whether or not to comply with guidance and self-isolate.

Conclusions

Decisions to self-isolate after a positive test were influenced by multiple factors, including individuals’ beliefs, concerns, priorities and personal circumstances. Future testing strategies must facilitate meaningful financial, practical and mental health support to allow individuals to overcome the perceived and actual negative consequences of isolating. Clear, consistent communication of the purpose and procedures of isolating will also be critical to support compliance with self-isolation guidance, and should leverage people’s perceived value in protecting others. Building public trust is also essential, but requires investment before the next pandemic starts.
Systematic review of clinical manifestations, management and outcome following accidental ingestion of liquid mosquito repellent vaporiser in children
Authors: Naeem Babar , Saleem Junaid , Haider Naqvi Agha Syed Ali , Kausar Sidra , Arshad Aqdas , Kumar Kantash , Khalid Aashar , Kumar Parkash
Published: March 2024

Background

Pyrethroid-based mosquito repellents are widely used to control mosquito-borne diseases. Liquid mosquito-repellent vaporisers are effective modes of pyrethroid delivery but can also pose significant health risks if ingested or used improperly.

Objective

This systematic review was performed to assess the demographic distribution, clinical presentation, management strategies and outcomes in children resulting from accidental ingestion of liquid mosquito repellent vaporiser.

Methods

The study adheres to the reporting standards outlined in the PRISMA Statement for Systematic Reviews and was prospectively registered with PROSPERO (record # CRD42023413937) to enhance transparency and minimise reporting bias. A comprehensive search was conducted on PubMed, Scopus and Google Scholar using specific MeSH terms related to insecticides, mosquito repellents, pyrethroids, ingestion, poisoning, toxicity and prevention. The reference lists of the included studies were also reviewed for additional relevant articles. The inclusion criteria involved studies published in peer-reviewed journals between 2000 and 2023 that focused on children under 18 years old with a history of mosquito-repellent ingestion based on primary data.

Results

Twelve studies met the inclusion criteria; these were primarily case reports from India, China and the UAE. Male children were predominantly affected, and symptoms included vomiting, convulsions, cough and respiratory distress. Management primarily involved supportive and symptomatic measures, including atropine for salivation and antiepileptic drugs for seizures. Respiratory support was provided for respiratory complications.

Conclusion

Despite the known risks and diverse presentations of pyrethroid poisoning caused by liquid mosquito repellent vaporiser in children, the limited substantial evidence in the literature underscores the urgent need for comprehensive research to refine management approaches and enhance preventive measures.
Morphology combined withHER2D-DISH ploidy analysis to diagnose partial hydatidiform mole: an evaluation audit using molecular genotyping
Authors: Joyce Caroline M , Maher Geoffrey J , Dineen Susan , Suraweera Nirosha , McCarthy Tommie V , Coulter John , O'Donoghue Keelin , Seckl Michael J , Fitzgerald Brendan
Published: March 2024

Aims

A hydatidiform mole (HM) is classified as complete (CHM) or partial (PHM) based on its morphology and genomic composition. Ancillary techniques are often required to confirm a morphologically suspected PHM diagnosis. This study sought to evaluate the clinical accuracy of PHM diagnosis using morphological assessment supported byHER2dual-colour dual-hapten in situ hybridisation (D-DISH) ploidy determination.

Methods

Over a 2-year period, our unit examined 1265 products of conception (POCs) from which 103 atypical POCs were diagnosed as PHM or non-molar conceptuses with the assistance ofHER2D-DISH ploidy analysis. We retrospectively audited a sample of 40 of these atypical POCs using short tandem repeat genotyping. DNA extracted from formalin-fixed paraffin-embedded tissue was genotyped using 24 polymorphic loci. Parental alleles in placental villi were identified by comparison to those in maternal decidua. To identify triploid PHM cases, we sought three alleles of equal peak height or two alleles with one allele peak twice the height of the other at each locus.

Results

Thirty-six of the 40 cases (19 PHM and 17 non-molar) were successfully genotyped and demonstrated complete concordance with the original diagnosis. All PHMs were diandric triploid of dispermic origin. In two non-molar diploid cases, we identified suspected trisomies (13 and 18), which potentially explains the pregnancy loss in these cases.

Conclusions

This study validates the use ofHER2D-DISH ploidy analysis to support the diagnosis of a morphologically suspected PHM in our practice.
Appraisal of hydatidiform mole incidence and registration rates in Ireland following the establishment of a National Gestational Trophoblastic Disease Registry
Authors: Joyce Caroline M , Wakefield Craig , Chen-Maxwell Daphne , Dineen Susan , Kenneally Caitriona , Downey Paul , Duffy Catherine , O'Donoghue Keelin , Coulter John , Fitzgerald Brendan
Published: March 2024

Aims

This study aimed to re-evaluate the incidence of hydatidiform mole (HM) and determine gestational trophoblastic disease (GTD) registration rates in Ireland following the establishment of the National GTD Registry in 2017.

Methods

We performed a 3-year retrospective audit of HM cases (January 2017 to December 2019) reported in our centre. In 2019, we surveyed Irish pathology laboratories to determine the number of HMs diagnosed nationally and compared this data to that recorded in the National GTD Registry. Additionally, we compared both local and national HM incidence rates to those reported internationally.

Results

In the 3-year local audit, we identified 87 HMs among 1856 products of conception (POCs) providing a local HM incidence rate of 3.92 per 1000 births. The 1-year pathology survey recorded 170 HMs in 6008 POCs, yielding a national incidence rate of 2.86 per 1000 births. Importantly, the local HM incidence rate exceeded the national incidence rate by 37% and the local partial HM incidence (1 in 296 births) was 64% higher than the nationally incidence rate (1 in 484 births). Notably, 42% of the HM and atypical POCs diagnosed nationally were not reported to the National GTD Registry.

Conclusions

Our study reveals increased HM incidence rates both locally and nationally compared with previous Irish studies. The higher local PHM incidence may reflect more limited access to ploidy analysis in other pathology laboratories nationally. Significantly, almost half of the women with diagnosed or suspected HM were not registered with the National GTD Centre.
Symmetry-based study and dynamics of casual bulk viscous matter-dominated universe
Authors: Nandi Tanmay , Choudhuri Amitava
Published: March 2024

The dynamics of cosmological expansion is studied for a spatially flat matter-dominated universe filled with barotropic casual bulk viscous fluid. The evolution equation for the Hubble parameter is derived using Friedmann equations and conservation law for the viscous fluid, in which the viscous pressure is modeled by truncated version of the full Israel-Stewart theory of bulk viscosity. We use a Lie symmetry-based approach to study the evolution of the expansion rate of the Universe. The model equation possesses eight-parameter Lie symmetry generators and gives two different analytic group invariant solutions for the Hubble parameter. Expressions for various important cosmological parameters are obtained and values are estimated analytically for the explanation of the evolution dynamics of the Universe. The interesting features of the obtained symmetry-based solutions are that, one satisfies the present acceleration of the Universe, while the other could not support present accelerating phase, rather represents a universe dominated by non-viscous stiff fluid. We make useful checks on the observational constraints on the model parameters from the latest released observational data. The accelerating phase of the current universe is investigated using observational bounds and compared the model under investigation with the $$\Lambda $$
Λ
CDM model. The evolutionary cosmic phases obtained from the analysis of the Lie symmetry-based solutions correspond to the association with the critical points in the equivalent phase space. These interesting features are investigated and analyzed using dynamical systems approach.
On the positivity of $$\overline{\textrm{MS}}$$ parton distributions
Authors: Candido Alessandro , Forte Stefano , Giani Tommaso , Hekhorn Felix
Published: March 2024

We revisit our argument that shows that parton distribution functions (PDFs) in the $$\overline{\textrm{MS}}$$

MS
¯

scheme are non-negative in the perturbative region, with the dual goals of clarifying its theoretical underpinnings and elucidating its domain of validity. We specifically discuss recent results proving that PDFs can turn negative at sufficiently low scale, we clarify quantitatively various aspects of our derivation of positivity in the perturbative region, and we provide an estimate for the scale above which PDF positivity holds.
$$(g-2)_{e,\mu }$$ anomalies and decays $$h\rightarrow e_a e_b$$, $$Z\rightarrow e_ae_b$$, and $$e_b\rightarrow e_a \gamma $$ in a two Higgs doublet model with inverse seesaw neutrinos
Authors: Hong T. T. , Tran Q. Duyet , Nguyen T. Phong , Hue L. T. , Nha N. H. T.
Published: March 2024

The lepton flavor violating decays$$h\rightarrow e_b^\pm e_a^\mp $$h→eb±ea∓,$$Z\rightarrow e_b^\pm e_a^\mp $$Z→eb±ea∓, and$$e_b\rightarrow e_a \gamma $$eb→eaγwill be discussed in the framework of the Two Higgs doublet model with presence of new inverse seesaw neutrinos and a singly charged Higgs boson that accommodate both$$1\sigma $$1σexperimental data of$$(g-2)$$(g-2)anomalies of the muon and electron. Numerical results indicate that there exist regions of the parameter space supporting all experimental data of$$(g-2)_{e,\mu }$$(g-2)e,μas well as the promising LFV signals corresponding to the future experimental sensitivities.
Insights into dynamical evolution and stability of thin-shell configurations through acoustic black holes
Authors: Javed Faisal , Waseem Arfa , Lin Ji , Sadiq Sobia , Mustafa G. , Alshehri Mansoor H.
Published: March 2024

The main goal of this work is to use the cut and paste method to match the inner flat and outer acoustic Schwarzschild black holes to examine the geometry of a thin-shell. Moreover, the study uses the Klein–Gordon equation and the equation of motion to examine the dynamical evolution of a thin-shell composed of massive as well as massless scalar field. The results of the study show that the collapsing behavior is exhibited by the potential function of a massless scalar shell while the effective potential of a massive scalar shell first collapses and then progressively increases. Additionally, the researchers have analyzed the stable configuration for the phantom-type equation of state encompassing dark energy, quintessence and phantom energy by applying the linearized radial perturbations. As a result, the research suggests that thin-shell Schwarzschild black holes are less stable than acoustic Schwarzschild black holes.
Thermal leptogenesis in nonextensive cosmology
Authors: Dehpour Mehran
Published: March 2024

Thermal leptogenesis is a mechanism that explains the observed asymmetry between matter and antimatter in the early universe. In this study, we review the impact of nonextensive Tsallis statistical mechanics on the early universe and study its effect on thermal leptogenesis. The study has found that the use of nonextensive statistical mechanics can affect the production of baryon asymmetry in thermal leptogenesis by modifying the equilibrium abundance of particles, decay, and washout parameters. Also, we show that nonextensive statistical mechanics potentially reduce the required right-handed neutrino mass scale.
Worldline path integral for the massive graviton
Authors: Fecit Filippo
Published: March 2024

We compute the counterterms necessary for the renormalization of the one-loop effective action of massive gravity from a worldline perspective. This is achieved by employing the recently proposed massive$$\mathcal {N}=4$$N=4spinning particle model to describe the propagation of the massive graviton on those backgrounds that solve the Einstein equations without cosmological constant, namely on Ricci-flat manifolds, in four dimensions. The model is extended to be consistent inDspacetime dimensions by relaxing the gauging of the full SO(4) R-symmetry group to a parabolic subgroup, together with the inclusion of a suitable Chern–Simons term. Then, constructing the worldline path integral on the one-dimensional torus allows for the correct calculation of the one-loop divergencies in arbitraryDdimensions. Our primary contribution is the determination of the Seleey–DeWitt coefficients up to the fourth coefficient$$a_3(D)$$a3(D), which to our knowledge has never been reported in the literature. Its calculation is generally laborious on the quantum field theory side, as a general formula for these coefficients is not available for operators that are non-minimal in the heat kernel sense. This work illustrates the computational efficiency of worldline methods in this regard. Heat kernel coefficients characterize linearized massive gravity in a gauge-independent manner due to the on-shell condition of the background on which the graviton propagates. They could serve as a benchmark for verifying alternative approaches to massive gravity, and, for this reason, their precise expression should be known explicitly.
Optimizing bonding performance in CF/PEKK composites: The role of IR heating and press consolidation
Authors: Kim Kang-Min , Kumar Sanjay , Kim Yun-Hae
Published: March 2024

Bonding performance of carbon fiber/polyetherketoneketone (CF/PEKK) laminates is closely related to crystallinity and is influenced by growth, formation, and density of spherulites. Press consolidation, with its ability to adjust pressure, exhibits superior quality compared to oven consolidation. However, bonding and production of CF/PEKK laminates using Press consolidation exhibit significant variations in quality depending on forming conditions. While research on producing CF/PEKK laminates using press consolidation is currently active, there is a lack of studies on co-consolidation for CF/PEKK laminates. Thus, in this study, establishment of forming process variables for press consolidation was conducted to achieve excellent bonding performance for CF/PEKK. Furthermore, IR heating-assisted surface heat treatment was employed to enhance bonding performance of CF/PEKK laminates by controlling crystallinity and spherulites. To analyze bonding performance, short bean shear testing was conducted to obtain interlaminar shear strength (ILSS). Results showed that surface modification through IR heating led to an increase in crystallinity and a noticeable growth in size of spherulites. In specific conditions, improved bonding performance was observed. This is judged to be primarily due to increase in spherulite size and crystallinity at bonding interface, attributed to specific conditions of both surface treatment through IR heating and Press consolidation.
Flexural behavior of carbon/epoxy nanocomposite pipes with interleaved structure
Authors: Park Ye-Rim , Kumar Sanjay , Naz Anam , Kim Yun-Hae
Published: March 2024

The filament winding process used in this study mainly produces pipe-shaped structures. In this structure, there is an intersection of fiber bundles, which makes the fiber bundles overlapping with other fiber bundles wavy. In that area, the concentration of stress and deformation appears. Therefore, halloysite nanotubes were applied among nanoparticles to supplement this through the study. In the utilization of nanoparticles, the control of agglomeration phenomena and the ease of dispersion are pivotal factors. In consideration of this, general halloysite nanotubes were heat-treated at 1000∘C to produce amorphous halloysite nanotubes to reduce the surface energy of particles, making it easier to control agglomeration phenomena and the ease of dispersion, and it was intended to supplement and improve mechanical properties in local applications through interleaved structure design. In this study, each stacked structure was analyzed through an axial pipe bending test. The fracture pattern for each structure was observed through an optical microscope. As a result, A3 reinforced with A-HNT for all layers had the highest load value (4207N), and the flexural strength was also measured high accordingly. It shows a small degree of fracture compared to other structures. Following that, E2A1, whose innermost layer was reinforced with A-HNT, had the second-highest load value (3864N), and accordingly, the second-highest flexural strength was measured. The observed surface of the pipe was the outermost layer (E), and it was observed that the degree of fracture was more advanced than that of A3.
Delamination mechanism in CF/EPOXY with open hole under mode II loading at different distances
Authors: Bang Tae-Sun , Kumar Sanjay , Kim Yun-Hae
Published: March 2024

This research addresses limitations in current aviation composite assembly techniques, often constrained by certification challenges. To enhance bonded composite components, open holes are frequently introduced, leading to increased vulnerability to delamination, a prominent failure mode in composite laminates. This study focuses on observing the impact of open holes on the mode II behavior of composites under various distances and hole diameter conditions. Results illustrate distinct load–displacement curves influenced by hole size, with shorter distances accelerating crack propagation, evidenced by reduced elastic regions and lower load values. Analyzing specimen appearances and crack patterns highlights stress concentration at the hole, influencing initiation and propagation. In the absence of a hole, cracks exhibit a zig-zag pattern near the loading point, while with a hole, they concentrate around it. Elastic region length varies with the pre-crack-to-hole distance, indicating accelerated crack propagation in shorter distances. This study underscores the direct influence of hole size on load values, emphasizing its pivotal role in determining composite mechanical properties. This research provides valuable insights into hole characteristics’ interplay with delamination behavior in carbon fiber-reinforced composites, essential for optimizing aerospace component design and structural integrity.
INVESTIGATION ON CONCRETE MICROSTRUCTURAL EVOLUTION AND SLOPE STABILITY BASED ON COUPLED FRACTAL FLUID–STRUCTURE MODEL
Authors: YANG TINGTING , LIU YANG , LIU GUANNAN , YU BOMING , WEI MINGYAO
Published: March 2024

Slope instability is a common type of damage in embankment dams. Analyzing its microstructural changes during water transport is beneficial to identify the critical damage point in more detail. To this end, we closely link both diffused water molecule and damaged concrete. On the basis of the original research on fractal theory, the fractal permeability model for the pore system is established. At the same time, considering the pore structure characteristics of concrete, the models for fluid–solid coupling inside and outside the embankment are established in this work. The simulated results and experimental data agree well, thus verifying the correctness of the proposed models. The changes of concrete pore structures under different water pressure and different initial porosities are simulated by numerical methods. The results show that: (1) with the increase of the safety factor, the slope of the embankment begins to be damaged at the critical point and then completely destabilized; (2) with the increase of the pressure head, the change of the fractal dimension of the embankment’s porosity from the top to the bottom changes from linear to nonlinear. (3) The initial porosity of concrete is proportional to the evolution of concrete pore structure. From a technical point of view, this study can contribute the effective technical guidance for related professional practitioners in the analysis of embankment slope stability from a microscopic point of view.
MRMI-TTS: Multi-Reference Audios and Mutual Information Driven Zero-Shot Voice Cloning
Authors: Chen Yi Ting , Li Wanting , Tang Buzhou
Published: March 2024

Voice cloning in text-to-speech (TTS) is the process of replicating the voice of a target speaker with limited data. Among various voice cloning techniques, this article focuses on zero-shot voice cloning. Although existing TTS models can generate high-quality speech for seen speakers, cloning the voice of an unseen speaker remains a challenging task. The key aspect of zero-shot voice cloning is to obtain a speaker embedding from the target speaker. Previous works have used a speaker encoder to obtain a fixed-size speaker embedding from a single reference audio unsupervised, but they suffer from insufficient speaker information and content information leakage in speaker embedding. To address these issues, this article proposes MRMI-TTS, a FastSpeech2-based framework that uses speaker embedding as a conditioning variable to provide speaker information. The MRMI-TTS extracts speaker embedding and content embedding from multi-reference audios using a speaker encoder and a content encoder. To obtain sufficient speaker information, multi-reference audios are selected based on sentence similarity. The proposed model applies mutual information minimization on the two embeddings to remove entangled information within each embedding. Experiments on the public English dataset VCTK show that our method can improve synthesized speech in terms of both similarity and naturalness, even for unseen speakers. Compared to state-of-the-art reference embedding learned methods, our method achieves the best performance on the zero-shot voice cloning task. Furthermore, we demonstrate that the proposed method has a better capability of maintaining the speaker embedding in different languages. Sample outputs are available on the demo page.1
RayNet: A Simulation Platform for Developing Reinforcement Learning-Driven Network Protocols
Authors: Giacomoni Luca , Benny Basil , Parisis George
Published: March 2024

Reinforcement Learning (RL) has gained significant momentum in the development of network protocols. However, RL-based protocols are still in their infancy, and substantial research is required to build deployable solutions. Developing a protocol based on RL is a complex and challenging process that involves several model design decisions and requires significant training and evaluation in real and simulated network topologies. Network simulators offer an efficient training environment for RL-based protocols because they are deterministic and can run in parallel. In this article, we introduce
RayNet
, a scalable and adaptable simulation platform for the development of RL-based network protocols. RayNet integrates OMNeT++, a fully programmable network simulator, with Ray/RLlib, a scalable training platform for distributed RL. RayNet facilitates the methodical development of RL-based network protocols so that researchers can focus on the problem at hand and not on implementation details of the learning aspect of their research. We developed a simple RL-based congestion control approach as a proof of concept showcasing that RayNet can be a valuable platform for RL-based research in computer networks, enabling scalable training and evaluation. We compared RayNet with
ns3-gym
, a platform with similar objectives to RayNet, and showed that RayNet performs better in terms of how fast agents can collect experience in RL environments.
A Survey on Automatic Generation of Figurative Language: From Rule-based Systems to Large Language Models
Authors: Lai Huiyuan , Nissim Malvina
Published: March 2024

Figurative language generation (FLG) is the task of reformulating a given text to include a desired figure of speech, such as a hyperbole, a simile, and several others, while still being faithful to the original context. This is a fundamental, yet challenging task in Natural Language Processing (NLP), which has recently received increased attention due to the promising performance brought by pre-trained language models. Our survey provides a systematic overview of the development of FLG, mostly in English, starting with the description of some common figures of speech, their corresponding generation tasks, and datasets. We then focus on various modelling approaches and assessment strategies, leading us to discussing some challenges in this field, and suggesting some potential directions for future research. To the best of our knowledge, this is the first survey that summarizes the progress of FLG including the most recent development in NLP. We also organize corresponding resources, e.g., article lists and datasets, and make them accessible in an open repository. We hope this survey can help researchers in NLP and related fields to easily track the academic frontier, providing them with a landscape and a roadmap of this area.
A Novel Pretrained General-purpose Vision Language Model for the Vietnamese Language
Authors: Vu Dinh Anh , Pham Quang Nhat Minh , Tran Giang Son
Published: March 2024

Lying in the cross-section of computer vision and natural language processing, vision language models are capable of processing images and text at once. These models are helpful in various tasks: text generation from image and vice versa, image-text retrieval, or visual navigation. Besides building a model trained on a dataset for a task, people also study general-purpose models to utilize many datasets for multitasks. Their two primary applications are image captioning and visual question answering. For English, large datasets and foundation models are already abundant. However, for Vietnamese, they are still limited. To expand the language range, this work proposes a pretrained general-purpose image-text model named VisualRoBERTa. A dataset of 600k images with captions (translated MS COCO 2017 from English to Vietnamese) is introduced to pretrain VisualRoBERTa. The model’s architecture is built using Convolutional Neural Network and Transformer blocks. Fine-tuning VisualRoBERTa shows promising results on the ViVQA dataset with 34.49% accuracy, 0.4173 BLEU 4, and 0.4390 RougeL (in visual question answering task), and best outcomes on the sViIC dataset with 0.6685 BLEU 4, 0.6320 RougeL (in image captioning task).
Cleansing Jewel: A Neural Spelling Correction Model Built On Google OCR-ed Tibetan Manuscripts
Authors: Luo Queenie , Chuang Yung-Sung
Published: March 2024

Scholars in the humanities heavily rely on ancient manuscripts to study history, religion, and socio-political structures of the past. Significant efforts have been devoted to digitizing these precious manuscripts using OCR technology. However, most manuscripts have been blemished over the centuries, making it unrealistic for OCR programs to accurately capture faded characters. This work presents the Transformer + Confidence Score mechanism architecture for post-processing Google’s Tibetan OCR-ed outputs. According to the Loss and Character Error Rate metrics, our Transformer + Confidence Score mechanism architecture proves superior to the Transformer, LSTM-to-LSTM, and GRU-to-GRU architectures. Our method can be adapted to any language dealing with post-processing OCR outputs.