bluuebunny/crossref_metadata_2025 huggingface dataset:
Disposition kinetics of meloxicam in green sea turtles (Chelonia mydas) after intravenous and intramuscular administrations
Authors: Poapolathep Amnart , Jongkolpath Oranee , Giorgi Mario , Klangkaew Narumol , Phaochoosak Napasorn , Chomcheun Thanaphan , Archawakulathep Amornthep , Poapolathep Saranya
Published: September 2023

The pharmacokinetics were described of meloxicam (MLX) in green sea turtles (Chelonia mydas), following a single intravenous (i.v.) and intramuscular (i.m.) administrations at one of two dosages of 0.1 or 0.2 mg/kg body weight (b.w.). The sample of 20 green sea turtles was divided into four groups (n = 5) using a randomization procedure according to a parallel study design. Blood samples were collected at pre‐assigned times up to 168 h. MLX in the plasma was cleaned‐up and quantified using a validated high‐performance liquid chromatography method with UV detection. The concentration of MLX in the experimental green sea turtles with respect to time was pharmacokinetically analyzed using a non‐compartment model. MLX plasma concentrations were quantifiable for up to 72 and 120 h after i.v. at dosages of 0.1 and 0.2 mg/kg b.w., respectively, whereas it was measurable for up to 168 h after i.m. administration at both dosages. The long elimination half‐life value of MLX (28 h) obtained in green sea turtles after i.v. administration was consistent with the quite slow clearance rate for both dosages. The average maximum concentration (Cmax) values of MLX were 1.05 μg/mL and 4.26 μg/mL at dosages of 0.1 and 0.2 mg/kg b.w., respectively, with their elimination half‐life values being 37.26 h and 30.64 h, respectively, after i.m. administrations. The absolute i.m. bioavailability was approximately 110%. These results suggested that i.m. administration of MLX at a dosage of 0.2 mg/kg b.w. was likely to be effective for clinical use in green sea turtles (Chelonia mydas). However, further studies are needed to determine the pharmacodynamic properties and clinical efficacy of MLX for the treatment of inflammatory disease after single and multiple dosages.
A territory‐wide opportunistic, hospital‐based HCV screening in the general population from northern Italy: The 1969–1989 birth‐cohort
Authors: D'Ambrosio Roberta , Piccinelli Sara , Beccalli Benedetta , Spinetti Angiola , Puoti Massimo , Fagiuoli Stefano , Magni Carlo Federico , Vavassori Andrea , Sacchi Paolo , Castaldi Silvana , Bombardieri Giulia , Farina Claudio , Buoro Sabrina , Amorosi Alessandro , Corradin Matteo , Cereda Danilo , Lampertico Pietro ,   the Regional HCV Working Group
Published: September 2023

Background and Aim

The World Health Organization (WHO) goal of Hepatitis C Virus (HCV) elimination by 2030 rose awareness about the need of screening plans, worldwide. In Italy, graduated screening starting from people born in 1969–1989 might be the most‐effective strategy. We performed an opportunistic HCV screening study in the general population attending health facilities in Lombardy region, Northern Italy.

Methods

This is a prospective, multicenter, territory‐wide, opportunistic study supported by the Regional Government of Lombardy, Italy. Between June 2022 and December 2022, all subjects born in 1969–1989, hospitalized or accessing blood collection centres were offered anti‐HCV and HCV–RNA tests. Patients with known anti‐HCV positivity and/or previous anti‐HCV treatment were excluded. Demographic features were uploaded into a regional web‐based platform.

Results

In total, 120 193 individuals were screened in 75 centres. Mean age was 44 (±6) years, 65.2% were females, 83.7% were tested at blood collection centres. Anti‐HCV tested positive in 604 (0.50%) subjects: mean age 47 (±5), 51.1% females. HCV seroprevalence was higher in males (p < 0.00001), elderly (p < 0.00001) and in‐ vs. outpatients (p = 0.0009). HCV–RNA was detectable in 125 out of 441 (28.3%) anti‐HCV positive subjects. Actively infected patients were 46 (±6) years old, mainly males (56.8%). The overall prevalence of active HCV infection was 0.10%, higher in elderly (p = 0.0003) and in in‐patients (p = 0.0007). Among 93 HCV–RNA positive patients, the median age was 48 years, 58% males, 62% Italian born, median HCV–RNA levels were 6,1 log IU/mL, liver stiffness measurement (LSM) values 5.5 (3.1–29.9) kPa and ALT levels 48 U/L.

Conclusions

The prevalence of active HCV infection in the 1969–1989 population attending health facilities in Lombardy was low. Most viremic patients were Italian‐born, with mild liver disease but high‐HCV–RNA levels. Due to the higher prevalence in the elderly, the extension of such opportunistic screening programs to lower birth cohorts would be warranted.
Mechanisms and treatment approaches for ACLF
Authors: Piano Salvatore , Mahmud Nadim , Caraceni Paolo , Tonon Marta , Mookerjee Rajeshwar Prosad
Published: September 2023

Acute‐on‐chronic liver failure (ACLF) is a life‐threatening syndrome characterized by decompensation of cirrhosis, severe systemic inflammation and organ failures. ACLF is frequently triggered by intra‐ and/or extrahepatic insults, such as bacterial infections, alcohol‐related hepatitis or flares of hepatic viruses. The imbalance between systemic inflammation and immune tolerance causes organ failures through the following mechanisms: (i) direct damage of immune cells/mediators; (ii) worsening of circulatory dysfunction resulting in organ hypoperfusion and (iii) metabolic alterations with prioritization of energetic substrates for inflammation and peripheral organ ‘energetic crisis’. Currently, the management of ACLF includes the support of organ failures, the identification and treatment of precipitating factors and expedited assessment for liver transplantation (LT). Early LT should be considered in patients with ACLF grade 3, who are unlikely to recover with the available treatments and have a mortality rate > 70% at 28 days. However, the selection of transplant candidates and their prioritization on the LT waiting list need standardization. Future challenges in the ACLF field include a better understanding of pathophysiological mechanisms leading to inflammation and organ failures, the development of specific treatments for the disease and personalized treatment approaches. Herein, we reviewed the current knowledge and future perspectives on mechanisms and treatment of ACLF.
Gut microbiota parallelism and divergence associated with colonisation of novel habitats
Authors: Härer Andreas , Mauro Alexander A. , Laurentino Telma G. , Rosenblum Erica B. , Rennison Diana J.
Published: September 2023

An organism's gut microbiota can change in response to novel environmental conditions, in particular when colonisation of new habitats is accompanied by shifts in the host species' ecology. Here, we investigated the gut microbiota of three lizard species (A. inornata,H. maculataandS. cowlesi) from their ancestral‐like habitat in the Chihuahuan desert and two colonised habitats with contrasting geological and ecological compositions: the White Sands and Carrizozo lava flow. The host species and the lizards' environment both shape gut microbiota composition, but host effects were overall stronger. Further, we found evidence that colonisation of the same environment by independent host species led to parallel changes of the gut microbiota, whereas the colonisation of two distinct environments by the same host species led to gut microbiota divergence. Some of the gut microbiota changes that accompanied the colonisation of the White Sands were associated with shifts in diet (based on diet information from previous studies), which is congruent with the general observation that trophic ecology has a strong effect on gut microbiota composition. Our study provides insights into how shifts in host ecology accompanying colonisation of novel environments can affect gut microbiota composition and diversity.
High climatic ancestral affinity between the lineages of the Leishmania vector Psathyromyia shannoni sensu stricto (Diptera: Phlebotominae)
Authors: Moo‐Llanes David A. , Montes de Oca‐Aguilar Ana C.
Published: September 2023

Psathyromyia (Psathyromyia) shannoni sensu stricto (Dyar) is a vector of Leishmania parasite and the second sandfly of medical importance with a wide geographical but discontinuous distribution in America. Preliminary genetic structure analysis using a mitochondrial marker shows that the species integrated by at least four lineages could be the result of ecological adaptations to different environmental scenarios, but this hypothesis had never been proven. The aim of the present study was to analyse whether the genetic structure that detected Pa. shannoni ss. is associated with divergence or conservatism niche. Using Ecological Niche Models (ENMs) theory, we estimated the potential distribution for each genetic lineage, and then, we evaluated the equivalency niche for assessing whether climatic niche was more different than expected. The ENMs identify different suitable distribution areas but the same climatic or ecological conditions for the genetic lineages of Pa. shannoni (conservatism niche). Our findings allow us to speculate that other potential processes or events could be related to the genetic differentiation of Pa. shannoni. These studies are important because they allow us to identify the factors that could restrict the potential distribution of the different lineages whose vectorial competence is still unknown.
Microbe‐dependent and independent nitrogen and phosphate acquisition and regulation in plants
Authors: Zhao Boyu , Jia Xianqing , Yu Nan , Murray Jeremy D. , Yi Keke , Wang Ertao
Published: September 2023

Nitrogen (N) and phosphorus (P) are the most important macronutrients required for plant growth and development. To cope with the limited and uneven distribution of N and P in complicated soil environments, plants have evolved intricate molecular strategies to improve nutrient acquisition that involve adaptive root development, production of root exudates, and the assistance of microbes. Recently, great advances have been made in understanding the regulation of N and P uptake and utilization and how plants balance the direct uptake of nutrients from the soil with the nutrient acquisition from beneficial microbes such as arbuscular mycorrhiza. Here, we summarize the major advances in these areas and highlight plant responses to changes in nutrient availability in the external environment through local and systemic signals.
A long‐term experiment reveals no trade‐off between seed persistence and seedling emergence
Authors: Chen Si‐Chong , Hu Xiao‐Wen , Baskin Carol C. , Baskin Jerry M.
Published: September 2023

Information on seed persistence and seedling emergence from the soil seed bank is critical for understanding species coexistence and predicting community dynamics. However, quantifying seed persistence in the soil is challenging; thus, its association with other life‐history traits is poorly known on a broad scale.

Using germination phenology for 349 species in a 42‐yr experiment, we quantified the persistence–emergence correlations and their associations with intrinsic regeneration traits using Bayesian phylogenetic multilevel models.

We showed no trade‐off between seed persistence and seedling emergence. Physically dormant seeds were more persistent but exhibited lower emergence than nondormant seeds. Monocarpic species had both higher persistence and emergence than polycarpic species. Seed mass posed a marginal proxy for persistence, while emergence almost doubled from the smallest to the largest seeds.

This study challenges the traditional assumption and is the first demonstration of noncorrelation between persistence and emergence, probably owing to the complexity of regenerative strategies. Species with short persistence and low emergence would be the most vulnerable for in situ conservation. Our analyses of this unique, long‐term dataset provide a strong incentive for further experimental studies and a rich data resource for future syntheses.
Uncertainty in surface wind speed projections over the Iberian Peninsula: CMIP6 GCMs versus a WRF‐RCM
Authors: Andres‐Martin Miguel , Azorin‐Molina Cesar , Shen Cheng , Fernández‐Alvarez José C. , Gimeno Luis , Vicente‐Serrano Sergio M. , Zha Jinlin
Published: September 2023

This study assessed the projected near‐surface wind speed (SWS) changes and variability over the Iberian Peninsula for the 21st century. Here, we compared Coupled Model Intercomparison Project Phase 6 global climate models (GCMs) with a higher spatial resolution regional climate model (RCM; ∼20 km), known as WRF‐CESM2, which was created by a dynamic downscaling of the Community Earth System Model version 2 (CESM2) using the Weather Research and Forecasting (WRF) model. Our analysis found that the GCMs tended to overestimate observed SWS for 1985–2014, while the higher spatial resolution of the WRF‐CESM2 did not improve the accuracy and underestimated the SWS magnitude. GCMs project a decline of SWS under high shared socioeconomic pathways (SSPs) greenhouse concentrations, such as SSP370 and SSP585, while an interdecadal oscillation appears in SSP126 and SSP245 for the end of the century. The WRF‐CESM2 under SSP585 predicts the opposite increasing SWS. Our results suggest that 21st‐century projections of SWS are uncertain even for regionalized products and should be taken with caution.
A novel SUCNR1 inhibitor alleviates dysbiosis through inhibition of host responses without direct interaction with host microbiota
Authors: Thomas Scott C. , Guo Yuqi , Xu Fangxi , Saxena Deepak , Li Xin
Published: September 2023

Type 2 diabetes (T2D) is a chronic metabolic disorder in which insulin resistance and impaired insulin secretion result in altered metabolite balance, specifically elevated levels of circulating glucose and succinate, which increases the risk of many pathologies, including periodontitis. Succinate, a tricarboxylic acid (TCA) cycle intermediate, can be produced and metabolized by both host cells and host microbiota, where elevated levels serve as an inflammation and pathogen threat signal through activating the succinate G protein‐coupled receptor, SUCNR1. Modulating succinate‐induced SUCNR1 signaling remains a promising therapeutic approach for pathologies resulting in elevated levels of succinate, such as T2D and periodontitis.

Here, we demonstrate hyperglycemia and elevated intracellular succinate in a T2D mouse model and determine gut microbiome composition. Drawing on previous work demonstrating the ability of a novel SUCNR1 antagonist, compound 7a, to block inflammation and alleviate dysbiosis in a mouse model, we examined if compound 7a has an impact on the growth and virulence gene expression of bacterial and fungal human microbiota in vitro, and if 7a could reduce bone loss in a periodontitis‐induced mouse model.

T2D mice harbored a significantly different gut microbiome, suggesting the altered metabolite profile of T2D causes shifts in host‐microbial community structure, with enrichment in succinate producers and consumers and mucin‐degrading bacteria. Bacterial and fungal cultures showed that 7a did not influence growth or virulence gene expression, suggesting the therapeutic effects of 7a are a direct result of 7a interacting with host cells and that alterations in microbial community structure are driven by reduced host SUCNR1 signaling. This work further suggests that targeting SUCNR1 signaling is a promising therapeutic approach in metabolic, inflammatory, or immune disorders with elevated succinate levels.
Ustilaginoidea virens‐secreted effector Uv1809 suppresses rice immunity by enhancing OsSRT2‐mediated histone deacetylation
Authors: Chen Xiaoyang , Liu Chen , Wang Hailin , Liu Qi , Yue Yaping , Duan Yuhang , Wang Zhaoyun , Zheng Lu , Chen Xiaolin , Wang Yaohui , Huang Junbin , Xu Qiutao , Pan Yuemin
Published: September 2023

Rice false smut caused by Ustilaginoidea virens is a devastating rice (Oryza sativa) disease worldwide. However, the molecular mechanisms underlying U. virens–rice interactions are largely unknown. In this study, we identified a secreted protein, Uv1809, as a key virulence factor. Heterologous expression of Uv1809 in rice enhanced susceptibility to rice false smut and bacterial blight. Host‐induced gene silencing of Uv1809 in rice enhanced resistance to U. virens, suggesting that Uv1809 inhibits rice immunity and promotes infection by U. virens. Uv1809 suppresses rice immunity by targeting and enhancing rice histone deacetylase OsSRT2‐mediated histone deacetylation, thereby reducing H4K5ac and H4K8ac levels and interfering with the transcriptional activation of defence genes. CRISPR‐Cas9 edited ossrt2 mutants showed no adverse effects in terms of growth and yield but displayed broad‐spectrum resistance to rice pathogens, revealing a potentially valuable genetic resource for breeding disease resistance. Our study provides insight into defence mechanisms against plant pathogens that inactivate plant immunity at the epigenetic level.
Molecular evolution of Cypridina noctiluca secretory luciferase for production of spectrum‐shifted luminescence‐emitting mutants and their application in nuclear receptor–reporter assays
Authors: Nishimiya Yoshiyuki , Morita Yosuke , Wu Chun , Ohyama Yasushi , Tochigi Yuki , Okuzawa Tsugumi , Sakashita Mami , Asakawa Atsushi , Irie Tsutomu , Ohmiya Yoshihiro , Ohgiya Satoru , Morita Naoki
Published: September 2023

Luciferase is a popular enzyme used for biological analyses, such as reporter assays. In addition to a conventional reporter assay using a pair of firefly and Renilla luciferases, a simple multicolor reporter assay using multiple firefly or beetle luciferases emitting different color luminescence with a single substrate has been reported. Secretory luciferases have also been used for convenient sample preparation in reporter assays; however, reporter assay using secretory luciferase mutants that emit spectrum‐shifted luminescence have not yet been reported. In this study, we generated blue‐ and red‐shifted (−16 and 12 nm) luminescence‐emitting Cypridina secretory luciferase (CLuc) mutants using multiple cycles of random and site‐directed mutagenesis. Even for red‐shifted CLuc mutant, which exhibited relatively low activity and stability, its enzymatic activity was sufficiently high for a luciferase assay (3.26 × 106 relative light unit/s), light emission was sufficiently prolonged (half‐life is 3 min), and stability at 37°C was high. We independently determined the luminescence of these CLuc mutants using a luminometer with an optical filter. Finally, we replaced the commonly used reporters, firefly and Renilla luciferases used in a conventional nuclear receptor–reporter assay with these CLuc mutants and established a secretory luciferase‐based single‐substrate dual‐color nuclear receptor–reporter assay.
Establishment of a new equation to estimate gestational age in female dogs
Authors: Pollis Elza S. C. , Padilha Felipe G. F. , Campos Isabela S. , Bartz Camila , Silva Franciele B. F. , Pinna Aline E. , Leite Juliana da Silva , Ferreira Ana M. R.
Published: September 2023

The objectives of this study were to propose a statistical model to predict the behaviour of the thickness of the uteroplacental junction as a function of the gestation period in female dogs and to determine the relationship between the thickness of the placenta and gestational age in healthy female dogs whose pregnancies had elapsed without maternal‐fetal alterations. Eight Border Collie female dogs were selected, aged 3–6 (4.48 ± 0.89) and weighing 16–22 kg (19.06 ± 1.9 kg). Female dogs with gestational ages from 20 to 62 days were examined weekly using B‐mode ultrasonography. Ultrasound measurements of the uteroplacental junction were organized into four distinct groups: GT1 (27–36 days of gestation), GT2 (37–46 days of gestation), GT3 (47–56 days of gestation) and GT4 (57–62 days of gestation). Based on multiple linear regression, a statistical model was proposed to predict the behaviour of the thickness of the uteroplacental junction (y) as a function of the length of gestation (x) in female dogs, where b0 is the intercept (linear coefficient) and bp is the slope of the predictors. The analysis relating GT, age and weight could predict placental thickness and resulted in a statistically significant model [F(1,28) = 153,736; p < .001; R2 = .846], but only that relating the length of pregnancy (β = .92; t = 12.399; p < .001) predicted the thickness of the placenta according to the equation y = b0 + bp.x1 [(thickness in cm) = β −0.3 + 0.019 × (gestation time in days)]. Only in GT4 was there no correlation between placentas within the same pregnancy (p > .05). Based on the close relationship between the development of the uteroplacental junction thickness during pregnancy and gestational age, it is possible to develop a new tool to complement gestational ultrasound evaluation in female dogs. This is important because it allows better placental evaluation in the search for significant alterations that could compromise maternal‐fetal health.
A citrate efflux transporter important for manganese distribution and phosphorus uptake in rice
Authors: Panchal Poonam , Bhatia Chitra , Chen Yi , Sharma Meenakshi , Bhadouria Jyoti , Verma Lokesh , Maurya Kanika , Miller Anthony J. , Giri Jitender
Published: September 2023

The plant citrate transporters, functional in mineral nutrient uptake and homeostasis, usually belong to the multidrug and toxic compound extrusion transporter family. We identified and functionally characterized a rice (Oryza sativa) citrate transporter, OsCT1, which differs from known plant citrate transporters and is structurally close to rice silicon transporters. Domain analysis depicted that OsCT1 carries a bacterial citrate‐metal transporter domain, CitMHS. OsCT1 showed citrate efflux activity when expressed in Xenopus laevis oocytes and is localized to the cell plasma membrane. It is highly expressed in the shoot and reproductive tissues of rice, and its promoter activity was visible in cells surrounding the vasculature. The OsCT1 knockout (KO) lines showed a reduced citrate content in the shoots and the root exudates, whereas overexpression (OE) line showed higher citrate exudation from their roots. Further, the KO and OE lines showed variations in the manganese (Mn) distribution leading to changes in their agronomical traits. Under deficient conditions (Mn‐sufficient conditions followed by 8 days of 0 μm MnCl2 · 4H2O treatment), the supply of manganese towards the newer leaf was found to be obstructed in the KO line. There were no significant differences in phosphorus (P) distribution; however, P uptake was reduced in the KO and increased in OE lines at the vegetative stage. Further, experiments in Xenopus oocytes revealed that OsCT1 could efflux citrate with Mn. In this way, we provide insights into a mechanism of citrate‐metal transport in plants and its role in mineral homeostasis, which remains conserved with their bacterial counterparts.
Canadian Blood Services traceback investigation of a suspected case of transfusion‐transmitted malaria
Authors: Tordon Bryan , Drews Steven J. , Flahr Francine , Bennett Kathleen , Gaziano Teresa , Anderson Danielle , Nahirniak Susan , Gerges Hanan , Tyrrell Gregory J. , Mah Jordan , Ndao Momar , Bigham Mark , Seftel Matthew
Published: September 2023

Background

A 4‐month‐old infant hospitalized since birth received multiple blood transfusions. In March 2022, Plasmodium falciparum was confirmed with nucleic acid testing. As the mother was assessed as unlikely to be the source of infection, the blood operator initiated a traceback investigation for a potential blood donor source. The patient had received 13 red blood cell (RBC) transfusions (aliquoted from 11 donors), 4 apheresis platelet (PLT) transfusions and 16 buffy coat pooled PLT transfusions. The blood operator medical team developed a supplementary malaria infection risk questionnaire to identify donors at highest risk of life‐time malaria infection, based on birthplace, residence, or travel in malaria‐endemic regions.

Results

With 79 donors initially implicated, initial focus was on donors of RBC components. The 11 RBC donors were contacted and assessed using the supplementary questionnaire. Three donors, all of whom met current malaria‐related donor eligibility criteria, were deemed high risk of prior malaria infection. These donors consented to P. falciparum serology and nucleic acid testing (NAT). One donor who was born and had resided in an endemic West African country for 14 years, was positive for P. falciparum by serology (indirect fluorescent antibody test) and NAT‐(Ct ≥32). Lookback of this donor's transfused fresh co‐components and prior donation identified no other malaria cases.

Conclusion

This was a probable transfusion‐transmitted malaria (TTM) case from an eligible donor who in retrospect was found to have unrecognized, asymptomatic, semi‐immune malaria infection, and who was potentially infectious. Blood donor lack of recall of prior malaria infection does not negate the risk of TTM from those who have lived in malaria‐endemic countries.
Counting functions for Dirichlet series and compactness of composition operators
Authors: Bayart Frédéric
Published: September 2023

We give a sufficient condition for a composition operator with positive characteristic to be compact on the Hardy space of Dirichlet series.
Effect of Trimmed Rear Shroud on Performance and Axial Thrust of Multi-Stage Centrifugal Pump With Emphasis on Visualizing Flow Losses
Authors: Gu Yandong , Sun Hao , Wang Chuan , Lu Rong , Liu Benqing , Ge Jie
Published: September 2023

Multi-stage centrifugal pumps are frequently used in high-lift applications and consume considerable energy, but suffer from poor performance and large axial force. The rear shroud of impeller is trimmed for reducing axial thrust, but this degrades performance. This study analyzes performance degradation and optimizes performance and axial force. Experiments and simulations are conducted on different ratios of rear shroud to front shroud (λ). Total pressure losses are calculated, and flow losses are visualized using the entropy generation method. Both measured and simulated performances decrease as the rear shroud is trimmed. Designs with different λ meet the head coefficient requirement of 1.1. However, λ of 0.86 has the best efficiency of 42.7%, λ of 0.83 reaches 42.5%, λ of 0.8 shows the lowest efficiency of 39.9%. Efficiency in the middle channel improves as the rear shroud is trimmed, but this cannot offset increased losses in the impeller and rear side chamber. Entropy production is exacerbated in the axial passage between impeller and rear side chamber due to the collision between impeller-driven flow and pressure-driven backflow. When λ is reduced by 0.03, axial thrust drops by 7%. To compromise between performance and axial thrust, λ should be designed at 0.83.
Poly (3,4-ethylenedioxythiophene): Poly (styrene sulfonate) Modified Laser Scribed Graphene for Flexible and Wearable Bioelectronics
Authors: Zhang Suheng , Yao Yao , Wang Yi
Published: September 2023

The rapid development of flexible and wearable electronic devices has increased the demand for highly flexible, conductive, and durable materials for device circuits. Over the past decade, laser-scribed graphene (LSG) has been widely employed for the contact-free and mask-free fabrication of conductive carbon circuits or patterns from polyimide or other precursors due to its excellent physiochemical properties. On the other hand, conducting polymer poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) has also been extensively studied for fabricating flexible electronics thanks to its excellent electronic/ionic conductivity and flexibility. However, both materials have their limitations, making them still difficult to use directly for manufacturing high-performance electronic devices. For example, the LSG is fragile and easily damaged, and PEDOT: PSS is easily clustered in aqueous solutions, reducing the conductivity. To overcome the limitations, in this paper, we report a facile and cost-effective LSG modifying method with PEDOT: PSS to enhance the performance, which combines the exceptional sensing properties of the PEDOT: PSS with the electronic advantages of the LSG. The modification method can be readily extended using inkjet printing or screen printing. The characterization and comparison experiments demonstrate that the electric conductivity can be improved to three times as that of the original LSG by PEDOT: PSS modification. The modified LSG has better flexibility, which is more suitable for flexible and wearable electronics.
Condenser Retrofit in Leibstadt Nuclear Power Plant (Boiling Water Reactor): Far Beyond a Standard Modular Solution
Authors: Wolf Hartwig , Wettstein Arthur , Faltermeier Robert , Graf Peter , Schupp Daniel
Published: September 2023

The Leibstadt nuclear power plant (KKL) in Switzerland was originally commissioned in 1984 with a nominal power output of 1000 MWel. Since then, there have been several uprates of the boiling water reactor (BWR), which have increased the power to 1275 MWel. After the nearly four decades of operation, the original condenser was impacted by advanced erosion corrosion and by progressive performance deterioration. In addition, the thermal power uprates required load reduction during hot summer periods to avoid high condenser back pressure. Consequently, KKL asked GE to carry out a comprehensive retrofit study to identify potential improvements on both lifetime and performance. These included robust material selection, optimized extraction of noncondensable gases by means of a bespoke air cooler section of the condenser and applying GE Steam Power's latest innovative tube pattern design, which is aligned to BWR requirements. However, site constraints prevented a typical modular condenser retrofit. Hence, working in a close cooperation between KKL and GE Steam Power, a customized retrofit concept was developed which used semi-prefabricated skeletal modules and an on-site rebuild of the condenser. In total, approximately 475 tons of old condenser material were dismantled, 24 new semi-prefabricated skeletal modules were installed, a condenser with 51,600 tubes was rebuilt on-site and 8 waterboxes were replaced with an improved design made of stainless steel. More than 350 professionals contributed to the successful retrofit with an overall site effort of 270,000 working hours—increasing the power output to 1285 MWel.
Prediction Enhancement of Machine Learning Using Time Series Modeling in Gas Turbines
Authors: Goyal Vipul , Xu Mengyu , Kapat Jayanta , Vesely Ladislav
Published: September 2023

This study is based on time-series data taken from the combined cycle heavy-duty utility gas turbines. For analysis, first a multistage vector autoregressive model is constructed for the nominal operation of the powerplant assuming sparsity in the association among variables and this is used as a basis for anomaly detection and prediction. This prediction is compared with the time-series data of the plant-operation containing anomalies. The comparative advantage based on prediction accuracy and applicability of the algorithms is discussed for the postprocessing. Next, the long-memory behavior of residuals is modeled, and heterogeneous variances are observed from the residuals of the generalized additive model. Autoregressive fractionally integrated moving average (ARFIMA) and generalized autoregressive conditional heteroskedasticity (GARCH) models are employed to fit the residual process, which significantly improve the prediction. Rolling one-step-ahead forecast is studied. Numerical experiments of abrupt changes and trend in the blade-path temperature are performed to evaluate the specificity and sensitivity of the prediction. The prediction is sensitive given reasonable signal-to-noise ratio and has lower false positive rate. The control chart is able to detect the simulated abrupt jump quickly.
Erratum to: Space–Time Structures in the Auroral Oval: Approaches to Modeling
Authors: Kozelov B. V.
Published: September 2023

An Erratum to this paper has been published: https://doi.org/10.1134/S001095252333002X
Lightweight Seizure Detection Based on Multi-Scale Channel Attention
Authors: Wang Ziwei , Hou Sujuan , Xiao Tiantian , Zhang Yongfeng , Lv Hongbin , Li Jiacheng , Zhao Shanshan , Zhao Yanna
Published: September 2023

Epilepsy is one kind of neurological disease characterized by recurring seizures. Recurrent seizures can cause ongoing negative mental and cognitive damage to the patient. Therefore, timely diagnosis and treatment of epilepsy are crucial for patients. Manual electroencephalography (EEG) signals analysis is time and energy consuming, making automatic detection using EEG signals particularly important. Many deep learning algorithms have thus been proposed to detect seizures. These methods rely on expensive and bulky hardware, which makes them unsuitable for deployment on devices with limited resources due to their high demands on computer resources. In this paper, we propose a novel lightweight neural network for seizure detection using pure convolutions, which is composed of inverted residual structure and multi-scale channel attention mechanism. Compared with other methods, our approach significantly reduces the computational complexity, making it possible to deploy on low-cost portable devices for seizures detection. We conduct experiments on the CHB-MIT dataset and achieves 98.7% accuracy, 98.3% sensitivity and 99.1% specificity with 2.68[Formula: see text]M multiply-accumulate operations (MACs) and only 88[Formula: see text]K parameters.
EXAMINATION OF THE IMPACTS OF CRYPTOCURRENCY UNCERTAINTY ON EXCHANGE-TRADED FUNDS
Authors: OMRI IMEN , OZCELEBI OGUZHAN
Published: September 2023

In this paper, we use quantile-based analysis and nonlinear conditional autoregressive value-at-risk (CAViaR) model to investigate how cryptocurrency price and policy uncertainty indexes affect exchange traded funds (ETFs) investing in equity securities of companies operating in various disruptive innovation sectors and related to digital assets and blockchain technology. Results of the quantile-on-quantile (QQ) estimates and quantile regression reveal that cryptocurrency price and policy uncertainty generally have a negative impact on the globally traded ETFs suggesting that the changes in cryptocurrency uncertainty lead to destabilizing effects in the ETF market. Moreover, we find that the impact of cryptocurrency uncertainty is asymmetric depending on each quantile of ETF returns even though each ETF is influenced in the same way by each uncertainty index, indicating that cryptocurrency price uncertainty and cryptocurrency policy uncertainty have common effects on the ETF market. A linear quantile causality analysis indicated that there is evidence of a significant causality running from the considered uncertainty indexes to the ETF returns, revealing that cryptocurrency price and policy uncertainty have a significant information value in explaining expected ETF returns. On the other hand, we find that linear quantile models outperform nonlinear CAViaR models in quantiles that are only moderate.
Quark confinement in Schwarzchild-like space–time with a metric generated by a nongravitational Yukawa-like strong field
Authors: Likéné A. Atangana , Ema’a Ema’a J. M. , Ele Abiama P. , Ben-Bolie G. H.
Published: September 2023

In this work, we use the approach recently introduced by Barros to study hadron spectra and some quark confinement properties in a Schwarzchild-like space–time generated by a nongravitational field. As a starting point, for the nongravitational field, we make the choice of a strong Yukawa-like field whose associated potential is a generalized Yukawa-like potential, typical of strong interactions. Then, from the latter field, the energy momentum tensor is constructed, the Einstein field equations are solved and the curvature function of the Schwarzchild metric is obtained. The correspondence principle applied to the Schwarzchild metric has enable us to construct the Dirac equation in the latter space. The resolution of the coupled differential equations of Dirac made it possible to obtain the energy spectrum of the strong interaction. The latter is obtained in a more general form than in the previous investigations. Then, the energy spectrum, masses and confinement radius of few hadrons are estimated and compared with experimental data and other theoretical studies. In most considered cases, our predictions are found to be in good agreement with experimental data. The good agreement observed between our outcomes and the experiment can be attributed to the choice of our potential, which has more free parameters than in past studies with the same approach.
Demystifying Practices, Challenges and Expected Features of Using GitHub Copilot
Authors: Zhang Beiqi , Liang Peng , Zhou Xiyu , Ahmad Aakash , Waseem Muhammad
Published: September 2023

With the advances in machine learning, there is a growing interest in AI-enabled tools for autocompleting source code. GitHub Copilot, also referred to as the “AI Pair Programmer”, has been trained on billions of lines of open source GitHub code, and is one of such tools that has been increasingly used since its launch in June 2021. However, little effort has been devoted to understanding the practices, challenges, and expected features of using Copilot in programming for auto-completed source code from the point of view of practitioners. To this end, we conducted an empirical study by collecting and analyzing the data from Stack Overflow (SO) and GitHub Discussions. More specifically, we searched and manually collected 303 SO posts and 927 GitHub discussions related to the usage of Copilot. We identified the programming languages, Integrated Development Environments (IDEs), technologies used with Copilot, functions implemented, benefits, limitations, and challenges when using Copilot. The results show that when practitioners use Copilot: (1) The major programming languages used with Copilot are JavaScript and Python, (2) the main IDE used with Copilot is Visual Studio Code, (3) the most common used technology with Copilot is Node.js, (4) the leading function implemented by Copilot is data processing, (5) the main purpose of users using Copilot is to help generate code, (6) the significant benefit of using Copilot is useful code generation, (7) the main limitation encountered by practitioners when using Copilot is difficulty of integration, and (8) the most common expected feature is that Copilot can be integrated with more IDEs. Our results suggest that using Copilot is like a double-edged sword, which requires developers to carefully consider various aspects when deciding whether or not to use it. Our study provides empirically grounded foundations that could inform software developers and practitioners, as well as provide a basis for future investigations on the role of Copilot as an AI pair programmer in software development.
GTFP: Network Fault Prediction Based on Graph and Time Series
Authors: Li Zhongliang , Ding Junjun , Ma Zongming
Published: September 2023

With the explosion of 5G network scale, the network structure becomes increasingly complex. During the operation of the network devices, the probability of anomalies or faults increases accordingly. Network faults may lead to the disappearance of important information and cause unpredictable losses. The prediction of network faults can enhance the quality of network services and reduce economic loss. In this paper, we propose the concept of 4D features and use the BERT algorithm to extract semantic features, the graph neural network algorithm to extract network topology information, and the Temporal Convolutional Network (TCN) algorithm to extract time series. Based on this, we propose Fault Prediction based on GraphSage and TCN (GTFP), an end-to-end solution of network fault alarm prediction, which is based on GraphSage and TCN (GTCN), a hybrid algorithm of a graph neural network and the TCN model. Our solution takes the historical alarm data as input. First, we filter out the alarm noises irrelevant to the faults through data cleaning. Then, we employ feature engineering to extract the valid alarm features, including the statistical features of the network alarm information, the semantic features of the alarm texts, the sequential features of the alarms and the network topology features of the nodes where the alarms are located. Finally, we use GTCN to predict future fault alarms based on the extracted features. Experiments on the alarm data of a real service system show that GTFP performs better than the state-of-the-art algorithms of fault alarm prediction.
Taking the high-edge route of rank-3 outer space
Authors: Gagnier Damara , Pfaff Catherine
Published: September 2023

Principal fully irreducible outer automorphisms were introduced in [Y. Algom-Kfir, I. Kapovich and C. Pfaff, Stable strata of geodesics in outer space, Int. Math. Res. Not. 2019(14) (2019) 4549–4578] to emulate principal pseudo-Anosov surface homeomorphisms, i.e. those whose attracting and repelling invariant foliations have only 3-pronged singularities. It is proved in [Y. Algom-Kfir, I. Kapovich and C. Pfaff, Stable strata of geodesics in outer space, Int. Math. Res. Not. 2019(14) (2019) 4549–4578] that these outer automorphisms semi-mimic principal pseudo-Anosov surface homeomorphisms in important ways. We prove here which rank-3 graphs carry train track representatives of principal fully irreducible outer automorphisms. As a corollary, one obtains which simplices of rank-3 Culler–Vogtmann outer space principal axes pass through.
A viable f(R) gravity model without oscillations in the effective dark energy
Authors: Oliveros A.
Published: September 2023

In this study, we propose a reparametrization of a specific viable [Formula: see text] gravity model to represent it as a perturbation of the [Formula: see text]CDM model. The [Formula: see text] gravity model under consideration includes two parameters, [Formula: see text] and [Formula: see text], which control how close the proposed model can be to [Formula: see text]CDM, allowing for arbitrary proximity. Furthermore, it is shown that the Hu–Sawicki (HS) model is a limiting case of this reparametrized model. Following the existing literature, we also derive an analytical approximation for the expansion rate [Formula: see text], which shows an excellent agreement between this analytical approximation and the numerical solution over a wide range of redshifts for realistic values of the deviation parameter [Formula: see text]. By appropriately selecting values for the model parameters, we plot the cosmological parameters [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], as well as the statefinder quantities [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. We find that their present values (at [Formula: see text]) are consistent with the observations from Planck 2018 and the values predicted by the [Formula: see text]CDM model. It is important to note that the examined cosmological and statefinder parameters do not exhibit significant oscillations of effective dark energy, which could lead to singular and unphysical solutions at high redshifts. This anomalous behavior has been avoided here by utilizing the approximate analytical solution for [Formula: see text]. Additionally, we conduct a detailed analysis of the evolution of matter density perturbations within the introduced [Formula: see text] gravity model. The results demonstrate that this viable [Formula: see text] gravity model is practically indistinguishable from the [Formula: see text]CDM model at the background level.
A LINEAR-PROGRAMMING PORTFOLIO OPTIMIZER TO MEAN–VARIANCE OPTIMIZATION
Authors: LIU XIAOYUE , HUANG ZHENZHONG , SONG BIWEI , ZHANG ZHEN
Published: September 2023

In the Markowitz mean–variance portfolio optimization problem, the estimation of the inverse covariance matrix is not trivial and can even be intractable, especially when the dimension is very high. In this paper, we propose a linear-programming portfolio optimizer (LPO) to solve the Markowitz optimization problem in both low-dimensional and high-dimensional settings. Instead of directly estimating the inverse covariance matrix [Formula: see text], the LPO method estimates the portfolio weights [Formula: see text] through solving an [Formula: see text]-constrained optimization problem. Moreover, we further prove that the LPO estimator asymptotically yields the maximum expected return while preserving the risk constraint. To offer a practical insight into the LPO approach, we provide a comprehensive implementation procedure of estimating portfolio weights via the Dantzig selector with sequential optimization (DASSO) algorithm and selecting the sparsity parameter through cross-validation. Simulations on both synthetic data and empirical data from Fama–French and the Center for Research in Security Prices (CRSP) databases validate the performance of the proposed method in comparison with other existing proposals.
STATE SPACE DECOMPOSITION AND CLASSIFICATION OF TERM STRUCTURE SHAPES IN THE TWO-FACTOR VASICEK MODEL
Authors: KELLER-RESSEL MARTIN , SACHSE FELIX
Published: September 2023

In this paper, we analyze the shapes of forward curves and yield curves that can be attained in the two-factor Vasicek model. We show how to partition the state space of the model, such that each partition is associated to a particular shape (normal, inverse, humped, etc.). The partitions and the corresponding shapes are determined by the winding number of a single curve with possible singularities and self-intersections, which can be constructed as the envelope of a family of lines. Building on these results, we classify possible transitions between term structure shapes, give results on attainability of shapes conditional on the level of the short rate, and propose a simple method to determine the relative frequency of different shapes of the forward curve and the yield curve.
Dynamic Response of Infinite Beam Resting on a Fractional Pasternak Viscoelastic Foundation Subjected to Moving Load
Authors: Ye Ti-Lei , Yan Ke-Zhen
Published: September 2023

In this paper, the dynamic response of an infinite Euler beam that was mounted on a fractional-order Pasternak viscoelastic foundation subjected to a moving point load was investigated. An analytical solution to the problem was derived using Fourier and Laplace transforms. Numerical results obtained by numerical Laplace inversion were analyzed to explore the impact of various parameters on the system’s response. The findings indicated that increasing system damping led to a decrease in maximum deflection and a more visible deformation hysteresis with an increase in fractional derivative orders. Additionally, all parameters of the foundation and shear layer were observed to have a significant effect on the deflection. The study confirmed that the fractional-order model predicted damping and dynamic deflection more accurately than the conventional integer-order foundation model. The research contributed to the understanding of the behavior of Euler beams mounted on viscoelastic foundations and provided valuable insights into the design of such systems.