bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of material removal rate and surface roughness during electric discharge machining of ultra‐fine grained Al6082 using Taguchi technique
Authors: Sarapure S.
Published: February 2023

In the current work, the statistical analysis of various electric discharge machining parameters on Al6082 ultra‐fine grained aluminium alloy using Taguchi method has been presented. Repetitive corrugation and straightening (RCS) method was employed to obtain ultra‐fine grained aluminium alloy. The electric discharge machining studies were carried out for test variables – pulse off time, pulse on time and current (I). The specimens were machined in dielectric medium with current range of 3 A to 9 A in step of 3 A. Machining features of the samples analysed statistically by adopting the Taguchi's ‐ design of experiments (DOE) methodology. Impact of parameters on material removal rate (MRR) and surface roughness (SR) were examined via signal‐to‐noise ratio (S/N ratio, expressed in decibel, dB) as well as analysis‐of‐variance (ANOVA). Outcomes disclose that every selected response explicitly surface roughness (SR) and material removal rate was significantly influenced by parameters. The material removal rate was found to rise with discharge current and decrease with the duration of pulse on time and the duration of pulse off time. On the other hand, the surface roughness increased with increase in peak current and decreased with pulse on time and pulse off time especially. The machining mechanisms were examined by scanning electron microscopy.
Optimization of cutting power and power efficiency during particleboard helical milling
Authors: Li R. , Yao Q. , Wang X.
Published: February 2023

With the aim of providing scientific guidance for the application of spiral cutters in particleboard machining, this work studied the influence of milling parameters on milling power and power efficiency during helical milling of particleboard. And the response surface methodology was applied to optimize the milling parameters to reduce machining energy consumption and improve energy efficiency. The factors of milling depth, spindle speed and helical angle were selected as input parameters, and the mathematical models between the input parameters and the response parameters were established. Then, the significant influence of each factor and the interaction of two factors were determined by variance analysis, and the change trend of milling power and power efficiency was studied by response surface methodology. Results showed that the milling depth had the greatest impact on milling power and power efficiency, followed by the spindle speed and helical angle. An increase in the milling depth and spindle speed resulted in an increase in milling power and power efficiency, while the increased helical angle resulted in a decrease in milling power and power efficiency. The optimized values of helical angle, spindle speed and milling depth were 54°, 5650 min−1 and 1.3 mm, respectively.
Measuring the effectiveness of anti‐cartel interventions in the shadow of recidivism1
Authors: Katsoulacos Yannis , Motchenkova Evgenia , Ulph David
Published: February 2023

It is important to measure the effectiveness of Competition Authority (CA) anti‐cartel enforcement, recognising that the total effect may be larger than the direct effect routinely measured by CAs because of the indirect/behavioural effects of interventions—primarily on deterrence. However, existing measurement methodologies assume that prosecuting and penalising cartels brings price fixing in an industry to an end forever. It is increasingly recognised that following successful prosecutions, collusion may re‐emerge and that the extent of such recidivism depends on the structure of post‐prosecution interventions. Failure to allow for possible re‐emergence could produce biased measures of CA effectiveness. We develop a framework for measuring the effectiveness of anti‐cartel interventions that admits that recidivism could arise depending on the nature of post‐prosecution interventions. Our general model nests the no recidivism assumption as a special case and, hence, improves upon the existing methodologies. The new framework enables us to measure the extent of bias arising from the failure to allow for recidivism, and we show that it can be significant. We make a number of other significant extensions to the existing frameworks. In particular, we allow for indirect price effects as well as indirect deterrence effects and analyse the marginal effects of CA interventions.
A total variation prior unrolling approach for computed tomography reconstruction
Authors: Zhang Pengcheng , Ren Shuhui , Liu Yi , Gui Zhiguo , Shangguan Hong , Wang Yanling , Shu Huazhong , Chen Yang
Published: February 2023

Background

With the rapid development of deep learning technology, deep neural networks can effectively enhance the performance of computed tomography (CT) reconstructions. One kind of commonly used method to construct CT reconstruction networks is to unroll the conventional iterative reconstruction (IR) methods to convolutional neural networks (CNNs). However, most unrolling methods primarily unroll the fidelity term of IR methods to CNNs, without unrolling the prior terms. The prior terms are always directly replaced by neural networks.

Purpose

In conventional IR methods, the prior terms play a vital role in improving the visual quality of reconstructed images. Unrolling the hand‐crafted prior terms to CNNs may provide a more specialized unrolling approach to further improve the performance of CT reconstruction. In this work, a primal‐dual network (PD‐Net) was proposed by unrolling both the data fidelity term and the total variation (TV) prior term, which effectively preserves the image edges and textures in the reconstructed images.

Methods

By further deriving the Chambolle–Pock (CP) algorithm instance for CT reconstruction, we discovered that the TV prior updates the reconstructed images with its divergences in each iteration of the solution process. Based on this discovery, CNNs were applied to yield the divergences of the feature maps for the reconstructed image generated in each iteration. Additionally, a loss function was applied to the predicted divergences of the reconstructed image to guarantee that the CNNs’ results were the divergences of the corresponding feature maps in the iteration. In this manner, the proposed CNNs seem to play the same roles in the PD‐Net as the TV prior in the IR methods. Thus, the TV prior in the CP algorithm instance can be directly unrolled to CNNs.

Results

The datasets from the Low‐Dose CT Image and Projection Data and the Piglet dataset were employed to assess the effectiveness of our proposed PD‐Net. Compared with conventional CT reconstruction methods, our proposed method effectively preserves the structural and textural information in reference to ground truth.

Conclusions

The experimental results show that our proposed PD‐Net framework is feasible for the implementation of CT reconstruction tasks. Owing to the promising results yielded by our proposed neural network, this study is intended to inspire further development of unrolling approaches by enabling the direct unrolling of hand‐crafted prior terms to CNNs.
Value of Surgical and Nonsurgical Treatment for Sleep Apnea: A Closer Look at Health Care Utilization
Authors: Abdelwahab Mohamed , Marques Sandro , Huang Allen , De Moraes Thyago P. , Previdelli Isolde , Cruz June Alisson Westarb , Al‐Sayed Ahmed A. , Capasso Robson
Published: February 2023

Objective

To determine how surgery, continuous positive airway pressure (CPAP), and no treatment impact health care utilization in patients who have obstructive sleep apnea (OSA).

Study Design

This is a retrospective cohort study of patients between the ages of 18 and 65 that were diagnosed with OSA (9th International Classification of Diseases) from January 2007 to December 2015. Data were collected over 2 years, and prediction models were generated to evaluate trends over time.

Setting

A population‐based study using real‐world data and insurance databases.

Methods

A total of 4,978,649 participants were identified, all with at least 25 months of continuous enrollment. Patients with previous soft tissue procedures not approved for OSA (nasal surgery), or without continuous insurance coverage were excluded. A total of 18,050 patients underwent surgery, 1,054,578 were untreated, and 799,370 received CPAP. IBM Marketscan Research database was utilized to describe patient‐specific clinical utilization, and expenditures, across outpatient, and inpatient services, and medication prescriptions.

Results

When the cost of the intervention was eliminated in the 2‐year follow‐up, the monthly payments of group 1 (surgery) were significantly less than group 3 (CPAP) in overall, inpatient, outpatient, and pharmaceutical payments (p < .001). The surgery group was associated with less cumulative payments compared to the other 2 groups when the cost of the intervention (CPAP or surgery) was eliminated in all comorbidities and age groups.

Conclusion

Treating OSA with surgery can lessen overall health care utilization compared to no treatment and CPAP.
Synthesis of dual physical self‐healing starch‐based hydrogels for repairing tissue defects
Authors: Hasan Shahriari Mehrnoosh , Abdouss Majid , Hadjizadeh Afra
Published: February 2023

Hydrogels have the potential to simulate and permeate body tissues. They can be used in many biomedical applications, such as drug delivery, wound dressings, contact lenses, synthetic implants, biosensors, and tissue engineering. Despite recent significant advances in hydrogel fabrication, with the introduction of double network hydrogels, with ionic or hydrogen bonds, there is still the challenge of achieving optimal mechanical properties with appropriate self‐healing ability. To solve the above problem, in this study, a new type of starch/chitosan/PVA/borax hydrogel was synthesized by adopting the one‐pot method. The effect of concentration and ratio of raw materials on the final properties of hydrogels, such as the degree of hydrophilicity, morphology, degradation, mechanical strength, and drug release rate, was investigated. The properties of hydrogels were examined by scanning electron microscopy, thermogravimetric analysis, Fourier‐transform infrared spectroscopy, X‐ray diffractometry, and contact angle, which confirmed the composite synthesis and uniform distribution of HNT and curcumin. In addition, the composite hydrogel showed excellent mechanical properties. Drug release studies confirmed that the drug is slowly released from the nanocomposite hydrogels. The results showed that starch‐based nanocomposite hydrogels could provide appropriate repairing potential for defects exposed to changeable parameters.
Quantifying the influence of encapsulant and backsheet composition on PV‐power and electrical degradation
Authors: Brune Barbara , Ortner Irene , Eder Gabriele C. , Voronko Yuliya , Oreski Gernot , Berger Karl A. , Knöbl Karl , Neumaier Lukas , Feichtner Markus
Published: February 2023

Although the technical and economic properties of the standard polymer photovoltaic (PV) materials (ethylene‐vinyl acetate (EVA) encapsulant and fluorine‐containing polyethylene terephthalate (PET) backsheet) meet the basic technical requirements, more sustainable polyolefin‐based encapsulants and backsheets have been developed. These new polyolefin materials have to prove their performance compared to the established standard materials in terms of the electrical performance of the modules and in terms of reliability. The long‐term stability of the new materials is tested and evaluated using accelerated aging tests and degradation modelling. Based on experimental results, the influence of the type of encapsulant and backsheet (i) on the electrical output power of PV test modules and (ii) on the aging‐related electrical and material degradation under accelerated stress tests was estimated using statistical modelling approaches. First results showing significant effects for encapsulant, backsheet and the combination of both on the initial power output are presented. In general, modules with polypropylene‐based backsheets have a higher initial power (PMPP) than those with PET‐based backsheets, with the combination of thermoplastic polyolefin (TPO) encapsulation material and polyolefin backsheet being superior to the other material combinations. A comparison of the material‐dependent degradation rates obtained from the mixed‐effects models clearly shows that the degradation rate upon damp heat exposure for modules with EVA is significantly larger than that using polyolefin encapsulants. The derived relations aim to provide valuable input for innovative material developments as well as predictive maintenance specifications.
ATP8B1: A prognostic prostate cancer biomarker identified via genetic analysis
Authors: Chen Lih‐Chyang , Huang Shu‐Pin , Shih Chieh‐Tien , Li Chia‐Yang , Chen Yei‐Tsung , Huang Chao‐Yuan , Yu Chia‐Cheng , Lin Victor C. , Lee Cheng‐Hsueh , Geng Jiun‐Hung , Bao Bo‐Ying
Published: February 2023

Background

Controlling the asymmetric distribution of phospholipids across biological membranes plays a pivotal role in the life cycle of cells; one of the most important contributors that maintain this lipid asymmetry are phospholipid‐transporting adenosine triphosphatases (ATPases). Although sufficient information regarding their association with cancer exists, there is limited evidence linking the genetic variants of phospholipid‐transporting ATPase family genes to prostate cancer in humans.

Methods

In this study, we investigated the association of 222 haplotype‐tagging single‐nucleotide polymorphisms (SNPs) in eight phospholipid‐transporting ATPase genes with cancer‐specific survival (CSS) and overall survival (OS) of 630 patients treated with androgen‐deprivation therapy (ADT) for prostate cancer.

Results

After multivariate Cox regression analysis and multiple testing correction, we found that ATP8B1 rs7239484 was remarkably associated with CSS and OS after ADT. A pooled analysis of multiple independent gene‐expression datasets demonstrated that ATP8B1 was under‐expressed in tumor tissues and that a higher ATP8B1 expression was associated with a better patient prognosis. Moreover, we established highly invasive sublines using two human prostate cancer cell lines to mimic cancer progression traits in vitro. The expression of ATP8B1 was consistently downregulated in both highly invasive sublines.

Conclusion

Our study indicates that rs7239484 is a prognostic factor for patients treated with ADT and that ATP8B1 can potentially attenuate prostate cancer progression.
Climate change, host plant availability, and irrigation shape future region‐specific distributions of the Sitobion grain aphid complex
Authors: Wang Bing‐Xin , Hof Anouschka R. , Matson Kevin D. , van Langevelde Frank , Ma Chun‐Sen
Published: February 2023

BACKGROUND

Understanding where species occur using species distribution models has become fundamental to ecology. Although much attention has been paid to invasive species, questions about climate change related range shifts of widespread insect pests remain unanswered. Here, we incorporated bioclimatic factors and host plant availability into CLIMEX models to predict distributions under future climate scenarios of major cereal pests of the Sitobion grain aphid complex (Sitobion avenae, S. miscanthi, and S. akebiae). Additionally, we incorporated the application of irrigation in our models to explore the relevance of a frequently used management practice that may interact with effects of climate change of the pest distributions.

RESULTS

Our models predicted that the area potentially at high risk of outbreaks of the Sitobion grain aphid complex would increase from 41.3% to 53.3% of the global land mass. This expansion was underlined by regional shifts in both directions: expansion of risk areas in North America, Europe, most of Asia, and Oceania, and contraction of risk areas in South America, Africa, and Australia. In addition, we found that host plant availability limited the potential distribution of pests, while the application of irrigation expanded it.

CONCLUSION

Our study provides insights into potential risk areas of insect pests and how climate, host plant availability, and irrigation affect the occurrence of the Sitobion grain aphid complex. Our results thereby support agricultural policy makers, farmers, and other stakeholders in their development and application of management practices aimed at maximizing crop yields and minimizing economic losses. © 2023 Society of Chemical Industry.
Computational design of clinical trials using a combination of simulation and the genetic algorithm
Authors: Tsuchiwata Shinichi , Tsuji Yasuhiro
Published: February 2023

Artificial intelligence (AI) has come to be used in various technological fields in recent years. However, there have been no reports of AI‐designed clinical trials. In this study, we tried to develop study designs by a genetic algorithm (GA), which is an AI solution for combination optimization problems. Specifically, the computational design approach was applied to optimize the blood sampling schedule for a bioequivalence (BE) study in pediatrics and optimize the allocation of dose groups for a dose‐finding study. The GA could reduce the number of blood collection points from 15 (typical standard) to seven points without meaningful impact on the accuracy and precision of the pharmacokinetic estimation for the pediatric BE study. For the dose‐finding study, up to 10% reduction of the total number of required subjects from the standard design could be achieved. The GA also created a design that would lead to a drastic reduction of the required number of subjects in the placebo arm while keeping the total number of subjects at a minimum level. These results indicated the potential usefulness of the computational clinical study design approach for innovative drug development.
Compositional Mapping of the AlGaN Alloy Composition in Graded Buffer Structures Using Cathodoluminescence
Authors: Loeto Kagiso , Kusch Gunnar , Ghosh Saptarsi , Frentrup Martin , Hinz Alexander , Oliver Rachel
Published: February 2023

Herein, the use of cathodoluminescence (CL) hyperspectral mapping in the quantification of the AlGaN alloy composition in graded buffer structures is explored. The quantification takes advantage of the known parabolic dependence of the AlGaN bandgap on the alloy composition allowing the AlGaN near‐band‐edge (NBE) emission energy recorded from CL to be converted to a composition. The proposed quantification method is first applied to cleaved cross‐sections of two nominally step‐graded AlGaN buffer structures each containing five AlGaN layers with different compositions. By comparing the compositions obtained from CL to those calculated using X‐ray diffraction, a close agreement between values from both techniques is observed. However, due to a change in the bowing parameter, some deviation is observed for layers with compositions near 75%. The method is then applied to cleaved cross‐sections of an AlGaN buffer whose group III precursor flow molar ratio is varied linearly throughout the growth. Herein, the hyperspectral nature of the CL datasets is exploited such as to produce composition maps by converting the relevant AlGaN‐NBE emission energy at each pixel of the CL data to a composition.
Mining adverse events in large frequency tables with ontology, with an application to the vaccine adverse event reporting system
Authors: Zhao Bangyao , Zhao Lili
Published: February 2023

Many statistical methods have been applied to VAERS (vaccine adverse event reporting system) database to study the safety of COVID‐19 vaccines. However, none of these methods considered the adverse event (AE) ontology. The AE ontology contains important information about biological similarities between AEs. In this paper, we develop a model to estimate vaccine‐AE associations while incorporating the AE ontology. We model a group of AEs using the zero‐inflated negative binomial model and then estimate the vaccine‐AE association using the empirical Bayes approach. This model handles the AE count data with excess zeros and allows borrowing information from related AEs. The proposed approach was evaluated by simulation studies and was further illustrated by an application to the Vaccine Adverse Event Reporting System (VAERS) dataset. The proposed method is implemented in an R package available at
https://github.com/umich‐biostatistics/zGPS.AO.
Graphene‐Oxide‐Coated, Polypyrrole‐Supported, Nano Zerovalent Iron Nanocomposites for Adsorption of Hexavalent Chromium from Wastewater
Authors: Waghmare Aakash , Rathore Roshni , Pandey Archna , Chandra Vimlesh
Published: February 2023

The hexavalent chromium in water is extremely toxic to most living organisms and can cause many diseases. In this work, we developed Polypyrrole (PPy), Polypyrrole/graphene oxide (PPy/GO) nanocomposite, and Polypyrrole/graphene oxide/zerovalent iron nanoparticles (PPy/GO/n‐ZVI) nanocomposite for adsorption of Cr (VI) from water. PPy/GO nanocomposite showed the highest Cr (VI) removal capacity for 10 % (weight) loading of GO. PPy/GO/n‐ZVI nanocomposite showed the highest Cr (VI) adsorption capacity for 50 % iron nanoparticle loading. Chemical kinetics data showed that Cr (VI) adsorption occurred with pseudo‐second‐order. The maximum adsorption capacity (qmax) was found to be 64.29 mg/g, 129.09 mg/g, and 171.04 mg/g on PPy, PPy/GO nanocomposite, and PPy/GO/n‐ZVI nanocomposite respectively. The thermodynamic study showed a positive value of ΔS, and a negative value of ΔG indicated rise in the disorder at the adsorbate‐adsorbent interface and spontaneous nature of Cr (VI) adsorption. ΔH was close to 21 kJ/mole indicating adsorption process occurred via physisorption. The recycling of the adsorbent was carried out by washing with sodium hydroxide and Cr (VI) removal efficiency decreased by around twenty % in the fifth cycle. The present study suggests that the PPy/GO/n‐ZVI nanocomposite is an environment‐friendly magnetic material and provides a simple, low‐cost strategy for the adsorption of Cr (VI) from wastewater.
Wafer‐Scale Fabrication of Hierarchically Porous Silicon and Silica by Active Nanoparticle‐Assisted Chemical Etching and Pseudomorphic Thermal Oxidation
Authors: Gries Stella , Brinker Manuel , Zeller‐Plumhoff Berit , Rings Dagmar , Krekeler Tobias , Longo Elena , Greving Imke , Huber Patrick
Published: February 2023

Many biological materials exhibit a multiscale porosity with small, mostly nanoscale pores as well as large, macroscopic capillaries to simultaneously achieve optimized mass transport capabilities and lightweight structures with large inner surfaces. Realizing such a hierarchical porosity in artificial materials necessitates often sophisticated and expensive top‐down processing that limits scalability. Here, an approach that combines self‐organized porosity based on metal‐assisted chemical etching (MACE) with photolithographically induced macroporosity for the synthesis of single‐crystalline silicon with a bimodal pore‐size distribution is presented, i.e., hexagonally arranged cylindrical macropores with 1 µm diameter separated by walls that are traversed by pores 60 nm across. The MACE process is mainly guided by a metal‐catalyzed reduction–oxidation reaction, where silver nanoparticles (AgNPs) serve as the catalyst. In this process, the AgNPs act as self‐propelled particles that are constantly removing silicon along their trajectories. High‐resolution X‐ray imaging and electron tomography reveal a resulting large open porosity and inner surface for potential applications in high‐performance energy storage, harvesting and conversion or for on‐chip sensorics and actuorics. Finally, the hierarchically porous silicon membranes can be transformed structure‐conserving by thermal oxidation into hierarchically porous amorphous silica, a material that could be of particular interest for opto‐fluidic and (bio‐)photonic applications due to its multiscale artificial vascularization.
Using artificial intelligence to find design errors in the engineering drawings
Authors: Dzhusupova Rimma , Banotra Richa , Bosch Jan , Olsson Helena Holmström
Published: February 2023

Artificial intelligence is increasingly becoming important to businesses because many companies have realized the benefits of applying machine learning (ML) and deep learning (DL) in their operations. ML and DL have become attractive technologies for organizations looking to automate repetitive tasks to reduce manual work and free up resources for innovation. Unlike rule‐based automation, typically used for standardized and predictable processes, machine learning, especially deep learning, can handle more complex tasks and learn over time, leading to greater accuracy and efficiency improvements. One of such promising applications is to use AI to reduce manual engineering work. This paper discusses a particular case within McDermott where the research team developed a DL model to do a quality check of complex blueprints. We describe the development and the final product of this case—AI‐based software for the engineering, procurement, and construction (EPC) industry that helps to find the design mistakes buried inside very complex engineering drawings called piping and instrumentation diagrams (P&IDs). We also present a cost‐benefit analysis and potential scale‐up of the developed software. Our goal is to share the successful experience of AI‐based product development that can substantially reduce the engineering hours and, therefore, reduce the project's overall costs. The developed solution can also be potentially applied to other EPC companies doing a similar design for complex installations with high safety standards like oil and gas or petrochemical plants because the design errors it captures are common within this industry. It also could motivate practitioners and researchers to create similar products for the various fields within engineering industry.
Application of the Phase Transformation Model for the Design of the Cooling Conditions in Stelmor Process to Obtain a Favorable Multiphase Microstructure of Wire Rod for Cold Heading Applications
Authors: Kuziak Roman , Zalecki Władysław , Radwański Krzysztof , Piwowarczyk Michał , Wolańska Natalia , Rauch Łukasz , Pietrzyk Maciej
Published: February 2023

The phase transformation model is the subject of this article capable of evaluating the hardenability of various bainitic steels. The objective is to provide a tool, which will help to design the chemical composition of steels with enhanced bainitic hardenability. Three general indexes, which are based on the relation between bainite volume fraction and cooling rate, and which characterize the hardenability, are proposed. Calculations of these hardenability indexes are presented for low‐carbon steels with different chemical compositions. Correlation between the chemistry and the hardenability factors is evaluated. Following this, an industrial process of cooling of wire rods is simulated for the steel with hardenability indexes adjusted to the cooling capabilities of Stelmor system. The cooling conditions, which give a favorable multiphase microstructure of wire rod for cold heading applications, are designed.
Mechanical behavior of semi‐grouting sleeve and steel bar connection
Authors: Ma Jinfeng , Bai Guoliang , Liang Lili , Wang Lei , Su Ningfen
Published: February 2023

A series of pull‐out tests were conducted on semi‐grouting sleeve and steel bar connections to investigate the mechanical behavior of the connectors. Taking the steel bar diameter, anchorage length, and grouting material strength as the parameters. The test results showed that when the anchorage length was small and the grouting material strength was low, sufficient anchorage strength cannot be provided, specimens were subjected to bond slip failure, which belongs to the brittle failure. When the anchorage strength between the steel bar and the grouting material was sufficient, the steel bar breaking occurred on the specimens, which belongs to the ductile failure. Then, the semi‐grouting sleeve and steel bar connection was modeled by finite element software, and the bond slip between the steel bar and grouting material was simulated by COMBIN39 element. The results indicated that the failure mode of the specimen obtained by finite element simulation was the same as the test result. The ultimate bearing capacity of the specimen was highly similar to the test result, which verified the feasibility of the modeling method in this paper. Next, the number of specimens and parameter levels were increased through finite element modeling, and the influences of steel bar diameter, anchorage strength, and grouting material strength on the ultimate bearing capacity of semi‐grouting sleeve and steel bar connections were analyzed. The results testified that the ultimate bearing capacity of the specimen increased with the increase of steel bar diameter. In a certain range, the ultimate bearing capacity of the specimen increased with the raising of anchorage length and grouting material strength. While the anchorage length increased, the ultimate bearing capacity of the specimen did not necessarily increase because of the uneven distribution of stress. The steel bar diameter had the most significant influence on the ultimate bearing capacity of the specimen, while the grouting material strength had the most negligible impact, that was, increasing the steel bar diameter is the most effective method to improve the ultimate bearing capacity of the specimen. Finally, according to the results of finite element analysis, the calculation method of ultimate bearing capacity with different failure modes was obtained, and it has been proved to be effective and accurate by the comparison of calculated results and test results. The results of this paper have great significance for improving the calculation theory and design method of relevant engineering.
A deformed IR: a new IR fixed point for four-dimensional holographic theories
Authors: Horowitz Gary T. , Kolanowski Maciej , Santos Jorge E.
Published: February 2023

Abstract

In holography, the IR behavior of a quantum system at nonzero density is described by the near horizon geometry of an extremal charged black hole. It is commonly believed that for systems onS3, this near horizon geometry is AdS2×S3. We show that this is not the case: generic static, nonspherical perturbations of AdS2×S3blow up at the horizon, showing that it is not a stable IR fixed point. We then construct a new near horizon geometry which is invariant under only SO(3) (and not SO(4)) symmetry and show that it is stable to SO(3)-preserving perturbations (but not in general). We also show that an open set of nonextremal, SO(3)-invariant charged black holes develop this new near horizon geometry in the limitT→ 0. Our new IR geometry still has AdS2symmetry, but it is warped over a deformed sphere. We also construct many other near horizon geometries, including some with no rotational symmetries, but expect them all to be unstable IR fixed points.
Modular linear differential equations for four-point sphere conformal blocks
Authors: Mahanta Ratul , Sengupta Tanmoy
Published: February 2023

Abstract

We construct modular linear differential equations (MLDEs) w.r.t. subgroups of the modular group whose solutions are Virasoro conformal blocks appearing in the expansion of a crossing symmetric 4-point correlator on the sphere. This uses a connection between crossing transformations and modular transformations. We focus specifically on second order MLDEs with the cases of all identical and pairwise identical operators in the correlator. The central charge, the dimensions of the above operators and those of the intermediate ones are expressed in terms of parameters that occur in such MLDEs. In doing so, the q-expansions of the solutions to the MLDEs are compared with those of Virasoro blocks; hence, Zamolodchikov’s elliptic recursion formula provides an important input. Using the actions of respective subgroups, bootstrap equations involving the associated 3-point coefficients have been set up and solved as well in terms of the MLDE parameters. We present explicit examples of MLDEs corresponding to BPZ and novel non-BPZ equations, as well as unitary and non-unitary CFTs.
A novel echocardiography method to assess upper body systemic blood flow in preterm infants and comparison with superior vena cava flow measurement
Authors: Schena Federico , Iannotta Rossella , D’Andrea Vito , Francescato Gaia , Mayer Alessandra , Mancini Giuseppina , Prontera Giorgia , Mosca Fabio , Vento Gianni
Published: February 2023

To evaluate feasibility, reproducibility, and prognostic value of a new echocardiographic method to assess systemic arterial blood flow directed to the upper part of the body (UBAF, upper body arterial flow) alternative to superior vena cava flow (SVCF) measurement. We performed echocardiographic evaluations in 106 infants in the first 2 days of life to obtain SVCF, left ventricle output (LVO), UBAF, and standard parameters of patent ductus arteriosus (PDA) significance. UBAF was calculated by subtracting from LVO the aortic arch blood flow measured immediately distally to the origin of the left subclavian artery. Main outcome measures: UBAF and SVCF agreement was assessed by Bland–Altman analysis in terms of bias, limits of agreement and repeatability index. The Intraclass Correlation Coefficient was used to measure the strength of inter-rater agreement. The agreement between UBAF and SVCF was high. The Concordance Correlation Coefficient (CCC) was 0.7434. (CCC 0.7434, 95% C.I. [0.656, 0.8111]). There was a good absolute agreement between the two raters ICC = 0.747; p value < 0.0001; 95%CI [0.601; 0.845]. Adjusting for confounding factors (BW, GA, PDA) included in the model, there was a statistically significant relationship between UBAF and SVCF.

Conclusion: UBAF showed a strong agreement with the SCVF with a better reproducibility. Our data support UBAF as a potentially useful marker of cerebral perfusion in the evaluation of preterm infants.

What is Known:• Low SVC (superior vena cava) flow in the neonatal period has been associated with periventricular haemorrhage and unfavourable long-term neurodevelopmental outcome.• Ultrasound measurement of flow in SVC shows relatively high inter-operator variability.

What is New:• Our study highlights how much overlap there is between upper-body arterial flow (UBAF) measurement and SCV flow measurement. UBAF is easier to perform and has a strong correlation with better reproducibility.• UBAF may replace measurement of cava flow as a method for haemodynamic monitoring of unstable preterm and asphyxiated infants.
On the finite representation of linear group equivariant operators via permutant measures
Authors: Bocchi Giovanni , Botteghi Stefano , Brasini Martina , Frosini Patrizio , Quercioli Nicola
Published: February 2023

Recent advances in machine learning have highlighted the importance of using group equivariant non-expansive operators for building neural networks in a more transparent and interpretable way. An operator is called equivariant with respect to a group if the action of the group commutes with the operator. Group equivariant non-expansive operators can be seen as multi-level components that can be joined and connected in order to form neural networks by applying the operations of chaining, convex combination and direct product. In this paper we prove that each linearG-equivariant non-expansive operator (GENEO) can be produced by a weighted summation associated with a suitable permutant measure, provided that the groupGtransitively acts on a finite signal domain. This result is based on the Birkhoff–von Neumann decomposition of doubly stochastic matrices and some well known facts in group theory. Our theorem makes available a new method to build all linear GENEOs with respect to a transitively acting group in the finite setting. This work is part of the research devoted to develop a good mathematical theory of GENEOs, seen as relevant components in machine learning.
Family language policy in retrospect: Narratives of success and failure in an Indian–Iranian transnational family
Authors: Mirvahedi Seyed Hadi , Hosseini Mona
Published: February 2023

In this study, we investigate family language policy in a transnational family through a collaborative autoethnography. Following the theoretical underpinnings of family language policy (Spolsky in J Multiling Multicult Dev 31:3–11, 2012), we present parental language beliefs, management, and practices in retrospect to shine a light on the long-term impact of the family’s language policy on their daughter’s linguistic development in heritage languages (i.e., Persian and Hindi) and English. The components of the family language policy in this cross-cultural transnational family are sketched in the second author’s narratives of her experiences of multilingual childrearing and heritage language maintenance. We engage with, and critique, recent family language scholarship that apply postmodernist lens to examine families’ translingual use of languages at home to get by their daily life, showing how having failed to set boundaries between the home/heritage languages and English over the past nine years has resulted in their child’s predominant proficiency in English. We argue that such failure has its roots in parents’ own past lived, and future imagined, experiences, as well as language ideologies that are polycentric and scaled, the consequences of which concern emotional, linguistic, cultural and social frictions across generations. Drawing on the narratives of success and failure in the family, we call for critical adoption of translingual frameworks in examining family language policy paying careful attention to the long-term impact of such practices at home on children’s linguistic development.
Effect of rewetting degraded peatlands on carbon fluxes: a meta-analysis
Authors: Darusman Taryono , Murdiyarso Daniel , Impron  , Anas Iswandi
Published: February 2023

Numerous studies claim that rewetting interventions reduce CO2 and increase CH4 fluxes. To verify the claim, we conducted a systematic review and meta-analysis of the effects of rewetting on CO2 and CH4 fluxes and dissolved organic carbon (DOC). We identified 28 primary articles eligible for meta-analysis, from which we calculated 48 effect sizes for CO2 emissions, 67 effect sizes for CH4 emissions, and 5 effect sizes for DOC. We found that rewetting significantly decreased CO2 fluxes, with temperate zones showing the highest Hedges’ g effect size (−0.798 ± 0.229), followed by tropical (−0.338 ± 0.269) and boreal (−0.209 ± 0.372) zones. Meanwhile, rewetting increased CH4 fluxes, with the highest Hedges’ g effect size shown in temperate zones (1.108 ± 0.144), followed by boreal (0.805 ± 0.183) and tropical (0.096 ± 0.284) zones. In addition, based on yearly monitoring after rewetting, the CH4 emissions effect size increased significantly over the first 4 years (r2 = 0.853). Overall, the rewetting intervention reduced CO2 emissions by −1.43 ± 0.35 Mg CO2–C ha−1 year−1, increased CH4 emissions by 0.033 ± 0.003 Mg CH4–C ha−1 year−1, and had no significant impact on DOC. To improve the precision and reduce the bias of rewetting effect size quantification, it is recommended to conduct more experimental studies with extended monitoring periods using larger sample sizes and apply the before-after control-impact study design, especially in boreal and tropical climate zones.
Predictive tracking of an object by a pan–tilt camera of a robot
Authors: Nebeluk Robert , Zarzycki Krzysztof , Seredyński Dawid , Chaber Patryk , Figat Maksym , Domański Paweł D. , Zieliński Cezary
Published: February 2023

Moving-object tracking using a pan–tilt camera setup is quite a well-known task in robotics. However, the presented research addresses specific properties of the tracked object and introduces novel features to the pan–tilt camera control strategy. Pan–tilt camera control does not operate in an isolated environment. It is a part of the visual servoing system with specific goals. The system has to fulfill certain purposes, which affect its configuration and functionality. The pan–tilt system aims at keeping the visually tracked object within the middle of the image. At the same time, the overall visual servoing efficiently recognizes and tracks the object enabling its grasping by the robot arm. It uses a predictive strategy utilizing specific second-order linear models for pan and tilt joints. Model predictive control (MPC) introduces into the system the ability to predict camera operation over the specific horizon according to the predefined tracking goals. As the system anticipates future positions over the horizon of operation, the setpoint prediction of the future tracked system positions is required. Visual object recognition and tracking system use particular strategies for preparing online tracked object extrapolation over MPC horizon. Therefore, the pan–tilt camera system is intrinsically coupled to camera-based recognition and tracking. Predictive pan–tilt positioning keeps the tracked system in the middle of the image, while the visual system extrapolation improves the tracking performance. The proposed approach is thoroughly tested in the dedicated Gazebo-based robot simulator. Finally, the system is implemented and validated on the Velma robot. The results and their comparison with other control strategies confirm the initial assumptions, allowing further visual servoing system development.
Effectiveness of a structured pharmacist-delivered intervention for patients post-acute coronary syndromes on all-cause hospitalizations and cardiac-related hospital readmissions: a prospective quasi-experimental study
Authors: El Hajj Maguy Saffouh , Kaddoura Rasha , Abu Yousef Safae E. A. , Orabi Bassant , Awaisu Ahmed , AlYafei Sumaya , Shami Rula , Mahfoud Ziyad R.
Published: February 2023

Background

Acute coronary syndrome (ACS) is a leading cause of mortality and morbidity in Qatar and globally.

Aim

The primary objective of the study was to evaluate the effectiveness of a structured clinical pharmacist-delivered intervention on all-cause hospitalizations and cardiac-related readmissions in patients with ACS.

Method

A prospective quasi-experimental study was conducted at Heart Hospital in Qatar. Discharged ACS patients were allocated to one of three study arms: (1) an intervention group (received a structured clinical pharmacist-delivered medication reconciliation and counselling at discharge, and two follow-up sessions at 4 weeks and 8 weeks post-discharge), (2) a usual care group (received the general usual care at discharge by clinical pharmacists) or, (3) a control group (discharged during weekends or after clinical pharmacists' working hours). Follow-up sessions for the intervention group were designed to re-educate and counsel patients about their medications, remind them about the importance of medication adherence, and answer any questions they may have. At the hospital, patients were allocated into one of the three groups based on intrinsic and natural allocation procedures. Recruitment of patients took place between March 2016 and December 2017. Data were analyzed based on intention-to-treat principles.

Results

Three hundred seventy-three patients were enrolled in the study (intervention = 111, usual care = 120, control = 142). Unadjusted results showed that the odds of 6-month all-cause hospitalizations were significantly higher among the usual care (OR 2.034; 95% CI: 1.103–3.748, p = 0.023) and the control arms (OR 2.704; 95% CI: 1.456–5.022, p = 0.002) when compared to the intervention arm. Similarly, patients in the usual care arm (OR 2.304; 95% CI: 1.122–4.730, p = 0.023) and the control arm (OR 3.678; 95% CI: 1.802–7.506, p ≤ 0.001) had greater likelihood of cardiac-related readmissions at 6 months. After adjustment, these reductions were only significant for cardiac-related readmissions between control and intervention groups (OR 2.428; 95% CI: 1.116–5.282, p = 0.025).

Conclusion

This study demonstrated the impact of a structured intervention by clinical pharmacists on cardiac-related readmissions at 6 months post-discharge in patients post-ACS. The impact of the intervention on all-cause hospitalization was not significant after adjustment for potential confounders. Large cost‐effective studies are required to determine the sustained impact of structured clinical pharmacist-provided interventions in ACS setting.

Trial registration

Clinical Trials: NCT02648243 Registration date: January 7, 2016.
Association of the chemical composition and nutritional value of forage resources in Colombia with methane emissions by enteric fermentation
Authors: Caicedo Yiniva Camargo , Garrido Galindo Angélica P. , Fuentes Inés Meriño , Vásquez Eliana Vergara
Published: February 2023

In the livestock sector, strategies are available to mitigate gas emissions, such as methane, one of the alternatives that have shown potential correspondence to changes in the composition of the diet. The main aim of this study was to analyze the influence of methane emissions with data on enteric fermentation obtained from the Electronic Data Gathering, Analysis, and Retrieval (EDGAR) database and based on forecasts of methane emissions by enteric fermentation with an autoregressive integrated moving average (ARIMA) model and the application of statistical tests to identify the association between methane emissions from enteric fermentation and the variables of the chemical composition and nutritional value of forage resources in Colombia. The results reported positive correlations between methane emissions and the variables ash content, ethereal extract, neutral detergent fiber (NDF), and acid detergent fiber (ADF) and negative correlations between methane emissions and the variables percentage of unstructured carbohydrates, total digestible nutrients (TDN), digestibility of dry matter, metabolizable energy (MERuminants), net maintenance energy (NEm), net energy gain (NEg), and net lactation energy (NEI). The variables with the most significant influence on the reduction of methane emissions by enteric fermentation are the percentage of unstructured carbohydrates and the percentage of starch. In conclusion, the analysis of variance and the correlations between the chemical composition and the nutritive value of forage resources in Colombia help to understand the influence of diet variables on methane emissions of a particular family and with it in the application of strategies of mitigation.
How European Salafism can make us reflect on a new typology of Salafism?
Authors: Adraoui Mohamed-Ali
Published: February 2023

This article focuses on contemporary Salafism in the European context and how it speaks to the categories Wiktorowicz put forth in his seminal 2006 article. Specifically, it examines how we can identify, describe, and classify the main forms of Salafist religiosity in the context of Western European countries. Furthermore, by examining the relationship to politics, preaching, and orthodoxy and orthopraxy in several European societies, this analysis contributes to the debate on the typologies of Salafism and proposes new ways of conceiving and distinguishing the forms of attachment to this vision of Islam in the context of countries where this religion is a minority. It also shows that the fundamentalist and radical currents are even more attached to it despite or because of the strong attention they receive from the public authorities and the media.