Modelling exchange rate volatility with random level shifts

Recent literature has shown that the volatility of exchange rate returns displays long memory features. It has also been shown that if a short memory process is contaminated by level shifts, the estimate of the long memory parameter tends to be upward biased. In this article, we directly estimate a random level shift model to the logarithm of the absolute returns of five exchange rates series, in order to assess whether random level shifts (RLSs) can explain this long memory property. Our results show that there are few level shifts for the five series, but once they are taken into account the long memory property of the series disappears. We also provide out-of-sample forecasting comparisons, which show that, in most cases, the RLS model outperforms popular models in forecasting volatility. We further support our results using a variety of robustness checks

Towards Secure Blockchain-enabled Internet of Vehicles: Optimizing Consensus Management Using Reputation and Contract Theory

In Internet of Vehicles (IoV), data sharing among vehicles is essential to improve driving safety and enhance vehicular services. To ensure data sharing security and traceability, highefficiency Delegated Proof-of-Stake consensus scheme as a hard security solution is utilized to establish blockchain-enabled IoV (BIoV). However, as miners are selected from miner candidates by stake-based voting, it is difficult to defend against voting collusion between the candidates and compromised high-stake vehicles, which introduces serious security challenges to the BIoV. To address such challenges, we propose a soft security enhancement solution including two stages: (i) miner selection and (ii) block verification. In the first stage, a reputation-based voting scheme for the blockchain is proposed to ensure secure miner selection. This scheme evaluates candidates' reputation by using both historical interactions and recommended opinions from other vehicles. The candidates with high reputation are selected to be active miners and standby miners. In the second stage, to prevent internal collusion among the active miners, a newly generated block is further verified and audited by the standby miners. To incentivize the standby miners to participate in block verification, we formulate interactions between the active miners and the standby miners by using contract theory, which takes block verification security and delay into consideration. Numerical results based on a real-world dataset indicate that our schemes are secure and efficient for data sharing in BIoV.Comment: 12 pages, submitted for possible journal publicatio

A Residual Fully Convolutional Network (Res-FCN) for Electromagnetic Inversion of High Contrast Scatterers at an Arbitrary Frequency Within a Wide Frequency Band

Many successful machine learning methods have been developed for electromagnetic inverse scattering problems. However, so far, their inversion has been performed only at the specifically trained frequencies. To make the machine-learning-based inversion method more generalizable for realistic engineering applications, this work proposes a residual fully convolutional network (Res-FCN) to perform EM inversion of high contrast scatterers at an arbitrary frequency within a wide frequency band. The proposed Res-FCN combines the advantages of the Res-Net and the fully convolutional network (FCN). Res-FCN consists of an encoder and a decoder: the encoder is employed to extract high-dimensional features from the measured scattered field through the residual frameworks, while the decoder is employed to map from the high-dimensional features extracted by the encoder to the electrical parameter distribution in the inversion region by the up-sample layer and the residual frameworks. Four numerical examples verify that the proposed Res-FCN can achieve good performance in the 2-D EM inversion problem for high contrast scatterers with anti-noise ability at an arbitrary frequency point within a wide frequency band

Automated Paper Screening for Clinical Reviews Using Large Language Models

Objective: To assess the performance of the OpenAI GPT API in accurately and efficiently identifying relevant titles and abstracts from real-world clinical review datasets and compare its performance against ground truth labelling by two independent human reviewers. Methods: We introduce a novel workflow using the OpenAI GPT API for screening titles and abstracts in clinical reviews. A Python script was created to make calls to the GPT API with the screening criteria in natural language and a corpus of title and abstract datasets that have been filtered by a minimum of two human reviewers. We compared the performance of our model against human-reviewed papers across six review papers, screening over 24,000 titles and abstracts. Results: Our results show an accuracy of 0.91, a sensitivity of excluded papers of 0.91, and a sensitivity of included papers of 0.76. On a randomly selected subset of papers, the GPT API demonstrated the ability to provide reasoning for its decisions and corrected its initial decision upon being asked to explain its reasoning for a subset of incorrect classifications. Conclusion: The GPT API has the potential to streamline the clinical review process, save valuable time and effort for researchers, and contribute to the overall quality of clinical reviews. By prioritizing the workflow and acting as an aid rather than a replacement for researchers and reviewers, the GPT API can enhance efficiency and lead to more accurate and reliable conclusions in medical research.Comment: 15 pages, 2 figures, 4 table

Modeling the Impact of an Indoor Air Filter on Air Pollution Exposure Reduction and Associated Mortality in Urban Delhi Household.

Indoor exposure to fine particulate matter (PM2.5) is a prominent health concern. However, few studies have examined the effectiveness of long-term use of indoor air filters for reduction of PM2.5 exposure and associated decrease in adverse health impacts in urban India. We conducted 20 simulations of yearlong personal exposure to PM2.5 in urban Delhi using the National Institute of Standards and Technology's CONTAM program (NIST, Gaithersburg, MD, USA). Simulation scenarios were developed to examine different air filter efficiencies, use schedules, and the influence of a smoker at home. We quantified associated mortality reductions with Household Air Pollution Intervention Tool (HAPIT, University of California, Berkeley, CA, USA). Without an air filter, we estimated an annual mean PM2.5 personal exposure of 103 µg/m3 (95% Confidence Interval (CI): 93, 112) and 137 µg/m3 (95% CI: 125, 149) for households without and with a smoker, respectively. All day use of a high-efficiency particle air (HEPA) filter would reduce personal PM2.5 exposure to 29 µg/m3 and 30 µg/m3, respectively. The reduced personal PM2.5 exposure from air filter use is associated with 8-37% reduction in mortality attributable to PM2.5 pollution in Delhi. The findings of this study indicate that air filter may provide significant improvements in indoor air quality and result in health benefits

Interventions to improve sanitation for preventing diarrhoea

BACKGROUND: Diarrhoea is a major contributor to the global disease burden, particularly amongst children under five years in low- and middle-income countries (LMICs). As many of the infectious agents associated with diarrhoea are transmitted through faeces, sanitation interventions to safely contain and manage human faeces have the potential to reduce exposure and diarrhoeal disease. OBJECTIVES: To assess the effectiveness of sanitation interventions for preventing diarrhoeal disease, alone or in combination with other WASH interventions. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, and Chinese language databases available under the China National Knowledge Infrastructure (CNKI-CAJ). We also searched the metaRegister of Controlled Trials (mRCT) and conference proceedings, contacted researchers, and searched references of included studies. The last search date was 16 February 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs), quasi-RCTs, non-randomized controlled trials (NRCTs), controlled before-and-after studies (CBAs), and matched cohort studies of interventions aimed at introducing or expanding the coverage and/or use of sanitation facilities in children and adults in any country or population. Our primary outcome of interest was diarrhoea and secondary outcomes included dysentery (bloody diarrhoea), persistent diarrhoea, hospital or clinical visits for diarrhoea, mortality, and adverse events. We included sanitation interventions whether they were conducted independently or in combination with other interventions. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed eligible studies, extracted relevant data, assessed risk of bias, and assessed the certainty of evidence using the GRADE approach. We used meta-analyses to estimate pooled measures of effect, described results narratively, and investigated potential sources of heterogeneity using subgroup analyses. MAIN RESULTS: Fifty-one studies met our inclusion criteria, with a total of 238,535 participants. Of these, 50 studies had sufficient information to be included in quantitative meta-analysis, including 17 cluster-RCTs and 33 studies with non-randomized study designs (20 NRCTs, one CBA, and 12 matched cohort studies). Most were conducted in LMICs and 86% were conducted in whole or part in rural areas. Studies covered three broad types of interventions: (1) providing access to any sanitation facility to participants without existing access practising open defecation, (2) improving participants' existing sanitation facility, or (3) behaviour change messaging to improve sanitation access or practices without providing hardware or subsidy, although many studies overlapped multiple categories. There was substantial heterogeneity amongst individual study results for all types of interventions. Providing access to any sanitation facility Providing access to sanitation facilities was evaluated in seven cluster-RCTs, and may reduce diarrhoea prevalence in all age groups (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.73 to 1.08; 7 trials, 40,129 participants, low-certainty evidence). In children under five years, access may have little or no effect on diarrhoea prevalence (RR 0.98, 95% CI 0.83 to 1.16, 4 trials, 16,215 participants, low-certainty evidence). Additional analysis in non-randomized studies was generally consistent with these findings. Pooled estimates across randomized and non-randomized studies provided similar protective estimates (all ages: RR 0.79, 95% CI 0.66 to 0.94; 15 studies, 73,511 participants; children < 5 years: RR 0.83, 95% CI 0.68 to 1.02; 11 studies, 25,614 participants).  Sanitation facility improvement Interventions designed to improve existing sanitation facilities were evaluated in three cluster-RCTs in children under five and may reduce diarrhoea prevalence (RR 0.85, 95% CI 0.69 to 1.06; 3 trials, 14,900 participants, low-certainty evidence). However, some of these interventions, such as sewerage connection, are not easily randomized. Non-randomized studies across participants of all ages provided estimates that improving sanitation facilities may reduce diarrhoea, but may be subject to confounding (RR 0.61, 95% CI 0.50 to 0.74; 23 studies, 117,639 participants, low-certainty evidence). Pooled estimates across randomized and non-randomized studies provided similar protective estimates (all ages: RR 0.65, 95% CI 0.55 to 0.78; 26 studies, 132,539 participants; children < 5 years: RR 0.70, 95% CI 0.54 to 0.91, 12 studies, 23,353 participants).  Behaviour change messaging only (no hardware or subsidy provided) Strategies to promote behaviour change to construct, upgrade, or use sanitation facilities were evaluated in seven cluster-RCTs in children under five, and probably reduce diarrhoea prevalence (RR 0.82, 95% CI 0.69 to 0.98; 7 studies, 28,909 participants, moderate-certainty evidence). Additional analysis from two non-randomized studies found no effect, though with very high uncertainty. Pooled estimates across randomized and non-randomized studies provided similar protective estimates (RR 0.85, 95% CI 0.73 to 1.01; 9 studies, 31,080 participants). No studies measured the effects of this type of intervention in older populations.  Any sanitation intervention A pooled analysis of cluster-RCTs across all sanitation interventions demonstrated that the interventions may reduce diarrhoea prevalence in all ages (RR 0.85, 95% CI 0.76 to 0.95, 17 trials, 83,938 participants, low-certainty evidence) and children under five (RR 0.87, 95% CI 0.77 to 0.97; 14 trials, 60,024 participants, low-certainty evidence). Non-randomized comparisons also demonstrated a protective effect, but may be subject to confounding. Pooled estimates across randomized and non-randomized studies provided similar protective estimates (all ages: RR 0.74, 95% CI 0.67 to 0.82; 50 studies, 237,130 participants; children < 5 years: RR 0.80, 95% CI 0.71 to 0.89; 32 studies, 80,047 participants). In subgroup analysis, there was some evidence of larger effects in studies with increased coverage amongst all participants (75% or higher coverage levels) and also some evidence that the effect decreased over longer follow-up times for children under five years. There was limited evidence on other outcomes. However, there was some evidence that any sanitation intervention was protective against dysentery (RR 0.74, 95% CI 0.54 to 1.00; 5 studies, 34,025 participants) and persistent diarrhoea (RR 0.57, 95% CI 0.43 to 0.75; 2 studies, 2665 participants), but not against clinic visits for diarrhoea (RR 0.86, 95% CI 0.44 to 1.67; 2 studies, 3720 participants) or all-cause mortality (RR 0.99, 95% CI 0.89 to1.09; 7 studies, 46,123 participants). AUTHORS' CONCLUSIONS: There is evidence that sanitation interventions are effective at preventing diarrhoea, both for young children and all age populations. The actual level of effectiveness, however, varies by type of intervention and setting. There is a need for research to better understand the factors that influence effectiveness

Role of follistatin-like 1 levels and functions in calcific aortic stenosis

BackgroundCalcific aortic valve disease (CAVD) is a progressive disease resulting in severe calcific aortic stenosis (AS), and there is increasing interest in the discovery of novel biomarkers to identify patients with potential future calcific AS at an early stage. This study aimed to determine whether follistatin-like 1 (FSTL1) is associated with calcific AS events and its exact role in aortic valve calcification.MethodsA prospective observational cohort study involving 656 patients was performed to investigate the relationship between serum FSTL1 and calcific AS incidence during a follow-up of 5 years. Furthermore, we detected FSTL1 levels in valvular interstitial cells (VICs) from calcified valves and explored the effects of FSTL1 on VIC osteogenic differentiation in vitro as well as the signaling pathways involved.ResultsDuring a median follow-up of 5 years, lower FSTL1 levels were associated with a significantly higher risk of calcific AS events (log rank test, P = 0.007). In addition, Cox multivariable regression analyses verified the predictive value of FSTL1 after adjusting for both demographic features and laboratory confounders. Consistent with our results for serum, a lower concentration of FSTL1 was observed in calcified human valves (n = 11) and mainly colocalized with VICs. Recombinant human FSTL1 (rhFSTL1) stimulation inhibited calcium deposition, alkaline phosphatase (ALP) activity, and osteogenic gene expression partly through the downregulation of the ERK1/2 pathway.ConclusionTaken together, this study provides a strong rationale to consider FSTL1 as a potential therapeutic target for calcific AS

Adaptation and validation of Richmond Compulsive Buying Scale in Chinese population

Background and aims Compulsive buying (CB) is a behavioral addiction that is conceptualized as an obsessive–compulsive and impulsive–control disorder. The Richmond Compulsive Buying Scale (RCBS), a six-item self-reporting instrument that has been validated worldwide, was developed based on this theoretical background. This study aimed to adapt RCBS to the Chinese population (RCBS-TC) to guide future national and international prevalence studies. Methods This methodological study was conducted in two phases. Phase 1 involved the forward and backward translation of RCBS, the content and face validation of the RCBS, and the evaluation of its translation adequacy. Phase 2 involved the psychometric testing of RCBS-TC for its internal consistency, stability, and construct validity using confirmatory factor analysis (CFA). Results In Phase 1, RCBS-TC obtained satisfactory item-level (I-CVI = 83.3%–100%) and scale-level content validity index (CVI/AVE = 97.2%), comprehensibility (100%), and translation adequacy [intraclass correlation coefficient (ICC) = 0.858]. In Phase 2, based on data collected from 821 adults, RCBS-TC demonstrated a satisfactory internal consistency (Cronbach’s α = .88; corrected item-total correlation coefficients = 0.61–0.78) 2-week test–retest reliability (ICC = 0.82 based on 61 university students). For construct validation, the CFA results indicated that the corrected first-order two-factor models were acceptable with the same goodness-of-fit indices (χ2/df = 8.56, CFI = 0.99, NFI = 0.98, IFI = 0.99, and RMSEA = 0.09). The 2-week test–retest reliability of RCBS-TC (n = 61) was also satisfactory (ICC = 0.82). Discussion and conclusions This methodological study adopted appropriate and stringent procedures to ensure that the translation and validation of RCBS-TC was of quality. The results indicate that this scale has a satisfactory reliability and validity for the Chinese population

Unraveling the transcriptome-based network of tfh cells in primary sjogren syndrome: insights from a systems biology approach

BackgroundPrimary Sjogren Syndrome (pSS) is an autoimmune disease characterized by immune cell infiltration. While the presence of follicular T helper (Tfh) cells in the glandular microenvironment has been observed, their biological functions and clinical significance remain poorly understood.MethodsWe enrolled a total of 106 patients with pSS and 46 patients without pSS for this study. Clinical data and labial salivary gland (LSG) biopsies were collected from all participants. Histological staining was performed to assess the distribution of Tfh cells and B cells. Transcriptome analysis using RNA-sequencing (RNA-seq) was conducted on 56 patients with pSS and 26 patients without pSS to uncover the underlying molecular mechanisms of Tfh cells. To categorize patients, we employed the single-sample gene set enrichment analysis (ssGSEA) algorithm, dividing them into low- and high-Tfh groups. We then utilized gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution tools to explore functional and immune infiltration differences between the low- and high-Tfh groups.ResultsPatients with pSS had a higher positive rate of the antinuclear antibody (ANA), anti-Ro52, anti-SSA, anti-SSB and hypergammaglobulinaemia and higher levels of serum IgG compared to the non-pSS. Histopathologic analyses revealed the presence of Tfh cells (CD4+CXCR5+ICOS+) in germinal centers (GC) within the labial glands of pSS patients. GSEA, WGCNA, and correlation analysis indicated that the high-Tfh group was associated with an immune response related to virus-mediated IFN response and metabolic processes, primarily characterized by hypoxia, elevated glycolysis, and oxidative phosphorylation levels. In pSS, most immune cell types exhibited significantly higher infiltration levels in the high-Tfh group compared to the low-Tfh group. Additionally, patients in the Tfh-high group demonstrated a higher positive rate of the ANA, rheumatoid factor (RF), and hypergammaglobulinaemia, as well as higher serum IgG levels.ConclusionOur study suggests that Tfh cells may play a crucial role in the pathogenesis of pSS and could serve as potential therapeutic targets in pSS patients

Perforating scleral vessels adjacent to myopic choroidal neovascularization achieved a poor outcome after intravitreal anti-VEGF therapy

BackgroundThis study aimed to summarize the features of perforating scleral vessels (PSVs) in patients with myopic choroidal neovascularization (CNV) (mCNV) using optical coherence tomography angiography (OCTA) and to identify the associations with the response after intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy.MethodsA consecutive series of naïve patients who had mCNV and received intravitreal anti-VEGF therapy with a follow-up duration of 12 months or more were enrolled. The prevalence, location, and branches of PSVs were analyzed. Projection-resolved OCTA (PR-OCTA) was used to analyze the neovascular signals between CNV and PSVs. Best corrected visual acuity (BCVA) and central macular thickness (CMT) were measured. The proportion of CMT change relative to baseline was used to assess therapeutic response.ResultsA total of 44 eyes from 42 patients with mCNV were enrolled. PSVs were identified in 41 out of 44 eyes. Branches were identified in the PSVs of 24 eyes (57.14%), and 20 eyes did not have PSV branches (47.62%). In eight eyes (18.18%), PSVs were adjacent to mCNV, and in 36 eyes (81.82%), PSVs were not adjacent to mCNV. After anti-VEGF therapy for mCNV, BCVA increased (F = 6.119, p &lt; 0.001) and CMT decreased (F = 7.664, p &lt; 0.001). In the eyes where PSVs were adjacent to mCNV, BCVA improvements (F = 7.649, p = 0.009) were poor, and changes in CMT were small.ConclusionThe eyes with PSVs adjacent to mCNV showed poor therapeutic responses after intravitreal anti-VEGF therapy