bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Control of a Nonlinear Series Elastic Cable Actuator Based on the Hill Muscle Model
Authors: Su Yingbing , Zou Huaiwu , Lu Hongrun , Hu Bingshan , Yu Hongliu
Published: February 2022

The bionic design of muscles is a research hotspot at present. Many researchers have designed bionic elastic actuators based on the Hill muscle model, and most of them include an active contraction element, passive contraction element and series elastic element, but they need more parametric design of mechanical structure and control under the guidance of Hill muscle model. In this research, a nonlinear series elastic cable actuating mechanism is designed in which the parameters of the elastic mechanism are optimized based on the Hill muscle model to fit the nonlinear passive elasticity of a muscle. Through the force–position relationship determined by the Hill muscle model, the output force and position of a nonlinear series elastic cable actuator are controlled to simulate the active contraction performance of a muscle. The experiments show that the proposed design and control method can make the nonlinear cable actuator have good muscle-like output force–displacement characteristics.
Exploring the Decisional Drivers of Deviance: A Qualitative Study of Institutionalized Adolescents in Malaysia
Authors: Yoga Ratnam Kishwen Kanna , Nik Farid Nik Daliana , Wong Li Ping , Yakub Nur Asyikin , Abd Hamid Mohd Alif Idham , Dahlui Maznah
Published: February 2022

Adolescents who break the law or deviate from social norms are often criminalized as their behavior is perceived as resulting from conscious choices. However, it is likely that such choices result from their circumstances, namely the failure of their proximal environment to safeguard their wellbeing. The purpose of this study was to gain an in-depth understanding of the background variables and choices that led these institutionalized adolescents down the road of deviance. We conducted a qualitative study using semi-structured in-depth interviews, conducted between March and May 2018, with 18 participants aged between 15 to 19 years. Participants were purposefully sampled from various welfare institutions in the states of Kuala Lumpur and Selangor, Malaysia. Audio recordings of interviews were transcribed verbatim and analyzed thematically. We found three core themes, (i) Sources of Distress, (ii) Drivers of Deviance, and (iii) Adjustment Strategies for Coping with Distress, which appeared to have influenced participants’ life trajectories and eventual institutionalization. The findings showed that participants were disadvantaged by backgrounds of risk and vulnerability, characterized by a lack of social support and opportunities for personal development, negative schooling experiences, and negative peer interactions. Substance abuse, which provided a coping strategy for the participants, may have further contributed to their delinquency. Drawing upon the socio ecological model (SEM), we systematically identify interventional opportunities at the individual, community, and policy levels to safeguard the wellbeing of at-risk adolescents. We make recommendations aimed at improving the family dynamics, promoting a healthy schooling experience, and transforming neighborhoods into a safe and nurturing environment.
Combined Use of Novel Endophytic and Rhizobacterial Strains Upregulates Antioxidant Enzyme Systems and Mineral Accumulation in Wheat
Authors: Iqbal Zafar , Bushra  , Hussain Azhar , Dar Abubakar , Ahmad Maqshoof , Wang Xiukang , Brtnicky Martin , Mustafa Adnan
Published: February 2022

Wheat is the third largest grown crop after maize and rice worldwide. Integrated use of chemical and biofertilizers have the potential to improve crop yield and quality due to their growth-promoting attributes. Therefore, the present study planned to evaluate the effectiveness of endophytic (Paenibacillus sp. strain (ZE11), Bacillus subtilis (ZE15) and Bacillus megaterium (ZE32)) and rhizobacterial strains (Bacillus subtilis (ZR2) Bacillus subtilis (ZR3) and Bacillus megaterium strain (ZR19)), solely and in combination, to increase the productivity of wheat and microbial activity in the rhizosphere. The maximum increase in microbial biomass carbon (44%), available phosphorous (30%), ammonium–nitrogen (24%), nitrate–nitrogen (37%), iron (10%), zinc (11%) and bacterial population (31%) was recorded by co-inoculation of ZE11 + ZR3. Subsequently, co-inoculation of ZE11+ZR3 showed a maximum increase of 31%, 29%, 30%, 27%, 33%, 30%, 25%, 9%, 15%, 9%, 18% and 26% in superoxidase dismutase (SOD), peroxidase dismutase (POD), catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and peroxidase (POX), grain yield, nitrogen, phosphorous, potassium, iron and zinc in grains, respectively, as compared to uninoculated control. The sole inoculation of ZR19 showed maximum harvest index (45.5%). The sole inoculation of endophytes and rhizobacteria has a significant effect on growth, physiology, and wheat crop yield. However, co-inoculation had a better effect and can be used to develop multi-strain biofertilizer to promote growth and yield of crops.
Antimicrobial Compounds from Microorganisms
Authors: Amaning Danquah Cynthia , Minkah Prince Amankwah Baffour , Osei Duah Junior Isaiah , Amankwah Kofi Bonsu , Somuah Samuel Owusu
Published: February 2022

Antimicrobial resistance is an exigent public health concern owing to the emergence of novel strains of human resistant pathogens and the concurrent rise in multi-drug resistance. An influx of new antimicrobials is urgently required to improve the treatment outcomes of infectious diseases and save lives. Plant metabolites and bioactive compounds from chemical synthesis have found their efficacy to be dwindling, despite some of them being developed as drugs and used to treat human infections for several decades. Microorganisms are considered untapped reservoirs for promising biomolecules with varying structural and functional antimicrobial activity. The advent of cost-effective and convenient model organisms, state-of-the-art molecular biology, omics technology, and machine learning has enhanced the bioprospecting of novel antimicrobial drugs and the identification of new drug targets. This review summarizes antimicrobial compounds isolated from microorganisms and reports on the modern tools and strategies for exploiting promising antimicrobial drug candidates. The investigation identified a plethora of novel compounds from microbial sources with excellent antimicrobial activity against disease-causing human pathogens. Researchers could maximize the use of novel model systems and advanced biomolecular and computational tools in exploiting lead antimicrobials, consequently ameliorating antimicrobial resistance.
Surgical Antimicrobial Prophylaxis in Patients of Neonatal and Pediatric Age Undergoing Orthopedic and Hand Surgery: A RAND/UCLA Appropriateness Method Consensus Study
Authors: Opri Francesca , Bianchini Sonia , Nicoletti Laura , Monaco Sara , Opri Roberta , Di Pietro Marilia , Carrara Elena , Rigotti Erika , Auriti Cinzia , Caminiti Caterina , Donà Daniele , Lancella Laura , Lo Vecchio Andrea , Pizzi Simone , Principi Nicola , Simonini Alessandro , Tesoro Simonetta , Venturini Eisabetta , Villani Alberto , Staiano Annamaria , Marchesini Reggiani Leonardo , Esposito Susanna ,   on behalf of the Peri-Operative Prophylaxis in Neonatal and Paediatric Age (POP-NeoPed) Study Group
Published: February 2022

Surgical site infections (SSIs) represent a potential complication in any type of surgery and can occur up to one year after the procedure in the case of implant placement. In the field of orthopedic and hand surgery, the rate of SSIs is a relevant issue, considering the need for the placement of synthesis devices and the type of some interventions (e.g., exposed fractures). This work aims to provide guidance on the management of peri-operative antibiotic prophylaxis for the pediatric and neonatal population undergoing orthopedic and hand surgery in order to standardize the management of patients and to reduce, on the one hand, the risk of SSI and, on the other, the development of antimicrobial resistance. The following scenarios were considered: (1) bloodless fracture reduction; (2) reduction of unexposed fracture and grade I and II exposed fracture; (3) reduction of grade III exposed fracture or traumatic amputation; (4) cruel fracture reduction with percutaneous synthesis; (5) non-traumatic amputation; (6) emergency intact skin trauma surgery and elective surgery without synthetic media placement; (7) elective orthopedic surgery with prosthetic and/or synthetic media placement and spinal surgery; (8) clean elective hand surgery with and without bone involvement, without use of synthetic means; (9) surgery of the hand on an elective basis with bone involvement and/or with use of synthetic means. This manuscript has been made possible by the multidisciplinary contribution of experts belonging to the most important Italian scientific societies and represents, in our opinion, the most complete and up-to-date collection of recommendations regarding the behavior to be adopted in the peri-operative setting in neonatal and pediatric orthopedic and hand surgery. The specific scenarios developed are aimed at guiding the healthcare professional in practice to ensure the better and standardized management of neonatal and pediatric patients, together with an easy consultation.
Effect of Antibiotic Prophylaxis on Surgical Site Infection in Thyroid and Parathyroid Surgery: A Systematic Review and Meta-Analysis
Authors: Polistena Andrea , Prete Francesco Paolo , Avenia Stefano , Cavallaro Giuseppe , Di Meo Giovanna , Pasculli Alessandro , Rondelli Fabio , Sanguinetti Alessandro , Sgaramella Lucia Ilaria , Avenia Nicola , Testini Mario , Gurrado Angela
Published: February 2022

Thyroid and parathyroid surgery are considered clean procedures, with an incidence of surgical site infection (SSI) after thyroidectomy ranging from 0.09% to 2.9%. International guidelines do not recommend routine antibiotic prophylaxis (AP), while AP seems to be employed commonly in clinical practice. The purpose of this systematic review is analyzing whether the postoperative SSI rate in thyroid and parathyroid surgery is altered by the practice of AP. We searched Pubmed, Scopus, the Cochrane Library, and Web of Science (WOS) for studies comparing AP to no preoperative antibiotics up to October 2021. Data on the SSI rate was evaluated and summarized as relative risks (RR) with 95% confidence intervals (95% CI). Risk of bias of studies were assessed with standard methods. Nine studies (4 RCTs and 5 nRCTs), including 8710 participants, were eligible for quantitative analysis. A meta-analysis showed that the SSI rate was not significantly different between AP and no preoperative antibiotics (SSI rate: 0.6% in AP vs. 2.4% in control group; RR 0.69, 0.43–1.10 95% CI, p = 0.13, I2 = 0%). A sensitivity analysis and subgroup analysis on RCTs were consistent with the main findings. Evidence of low quality supports that AP in thyroid and parathyroid surgery produce similar SSI rates as to the absence of perioperative antibiotics.
Pharmacodynamics of Ceftriaxone, Ertapenem, Fosfomycin and Gentamicin in Neisseria gonorrhoeae
Authors: Gubenšek Urša , de Laat Myrthe , Foerster Sunniva , Boyd Anders , van Dam Alje Pieter
Published: February 2022

Objectives: To assess the in vitro effect of select antimicrobials on the growth of N. gonorrhoeae and its pharmacodynamic parameters. Methods: Time–kill assays were performed on two reference N. gonorrhoeae strains (ceftriaxone-resistant WHO X and ceftriaxone-susceptible WHO F) and one clinical N. gonorrhoeae strain (ceftriaxone-susceptible CS03307). Time–kill curves were constructed for each strain by measuring bacterial growth rates at doubling antimicrobial concentrations of ceftriaxone, ertapenem, fosfomycin and gentamicin. Inputs from these curves were used to estimate minimal bacterial growth rates at high antimicrobial concentrations (ψmin), maximum bacterial growth rates in the absence of antimicrobials (ψmax), pharmacodynamic minimum inhibitory concentrations (zMIC), and Hill’s coefficients (κ). Results: Ceftriaxone, ertapenem and fosfomycin showed gradual death overtime at higher antimicrobial concentrations with a relatively high ψmin, demonstrating time-dependent activity. Compared to WHO F, the ψmin for WHO X was significantly increased, reflecting decreased killing activity for ceftriaxone, ertapenem and fosfomycin. At high ceftriaxone concentrations, WHO X was still efficiently killed. CS03307 also showed a high ψmin for ceftriaxone in spite of a low MIC and no difference in ψmin for fosfomycin in spite of significant MIC and zMIC differences. Gentamicin showed rapid killing for all three strains at high concentrations, demonstrating concentration-dependent activity. Conclusions: Based on time–kill assays, high-dosage ceftriaxone could be used to treat N. gonorrhoeae strains with MIC above breakpoint, with gentamicin as a potential alternative. Whether ertapenem or fosfomycin would be effective to treat strains with a high MIC to ceftriaxone is questionable.
Andrological Aspects of Exercise: Moderate Swimming Protects against Isoproterenol Induced Testis and Semen Abnormalities in Rats
Authors: Osváth Péter , Szűcs Miklós , Börzsei Denise , Szabó Renáta , Lesi Zelma Nadin , Turcsán Zsolt , Veszelka Médea , Sebestyén Judith , Juhász Béla , Priksz Dániel , Varga Csaba , Pósa Anikó
Published: February 2022

The development and progression of male infertility are closely linked to a sedentary lifestyle; however, its underlying mechanisms are not fully elucidated. Our aim was to assess the protective effects of moderate swimming exercise on the male reproductive system in isoproterenol-treated rats. Male Wistar rats were divided into five groups as follows: (1) non-interventional controls (CTRL), (2) isoproterenol-treated (ISO), (3) pre-treatment swimming training + ISO (PRE + ISO), (4) ISO + post-treatment swimming training (ISO+POST), (5) pre-treatment swimming training + ISO + post-treatment swimming training (PRE + ISO + POST) groups. Testicular oxidative stress was induced by ISO injection (1.0 mg/kg). Rats in the pre- or post-training groups were trained five days a week. At the end of the experimental period, serum testosterone levels, sperms’ hyaluronan binding, and total glutathione (GSH) content, as well as myeloperoxidase activity (MPO), TNF alpha and IL6 concentrations in the testis and semen, were measured. Serum testosterone levels, sperms’ hyaluronan binding, and GSH content were found to be significantly reduced, while MPO, TNF alpha and IL6 concentrations in the testis and semen were elevated after the ISO treatment compared to the CTRL group. Moderate-intensity swimming exercise effectively alleviated the negative effects of high oxidative stress. Our findings provide the first evidence that moderate-intensity swimming exercise confers sustained protection from isoproterenol-induced adverse effects on testicular inflammation.
Redox-Related Proteins in Melanoma Progression
Authors: Carvalho Larissa A. C. , Queijo Rodrigo G. , Baccaro Alexandre L. B. , Siena Ádamo D. D. , Silva Wilson A. , Rodrigues Tiago , Maria-Engler Silvya Stuchi
Published: February 2022

Melanoma is the most aggressive type of skin cancer. Despite the available therapies, the minimum residual disease is still refractory. Reactive oxygen and nitrogen species (ROS and RNS) play a dual role in melanoma, where redox imbalance is involved from initiation to metastasis and resistance. Redox proteins modulate the disease by controlling ROS/RNS levels in immune response, proliferation, invasion, and relapse. Chemotherapeutics such as BRAF and MEK inhibitors promote oxidative stress, but high ROS/RNS amounts with a robust antioxidant system allow cells to be adaptive and cooperate to non-toxic levels. These proteins could act as biomarkers and possible targets. By understanding the complex mechanisms involved in adaptation and searching for new targets to make cells more susceptible to treatment, the disease might be overcome. Therefore, exploring the role of redox-sensitive proteins and the modulation of redox homeostasis may provide clues to new therapies. This study analyzes information obtained from a public cohort of melanoma patients about the expression of redox-generating and detoxifying proteins in melanoma during the disease stages, genetic alterations, and overall patient survival status. According to our analysis, 66% of the isoforms presented differential expression on melanoma progression: NOS2, SOD1, NOX4, PRX3, PXDN and GPX1 are increased during melanoma progression, while CAT, GPX3, TXNIP, and PRX2 are decreased. Besides, the stage of the disease could influence the result as well. The levels of PRX1, PRX5 and PRX6 can be increased or decreased depending on the stage. We showed that all analyzed isoforms presented some genetic alteration on the gene, most of them (78%) for increased mRNA expression. Interestingly, 34% of all melanoma patients showed genetic alterations on TRX1, most for decreased mRNA expression. Additionally, 15% of the isoforms showed a significant reduction in overall patient survival status for an altered group (PRX3, PRX5, TR2, and GR) and the unaltered group (NOX4). Although no such specific antioxidant therapy is approved for melanoma yet, inhibitors or mimetics of these redox-sensitive proteins have achieved very promising results. We foresee that forthcoming investigations on the modulation of these proteins will bring significant advances for cancer therapy.
Coriander Oil Reverses Dexamethasone-Induced Insulin Resistance in Rats
Authors: Mahmoud Mona F. , Ali Noura , Mostafa Islam , Hasan Rehab A. , Sobeh Mansour
Published: February 2022

In the present study, we aimed to investigate the effect of coriander oil on dexamethasone-induced insulin resistance in rats and characterize its chemical composition using gas chromatography-mass spectrometry (GC-MS). Rats were divided into five groups (n = 6): Normal control, insulin resistance (IR) control, IR + metformin (50 mg/kg/day, PO, Per Oral), IR + coriander oil low dose (0.5 mL/kg, PO), and IR + coriander oil high dose (1 mL/kg, PO). IR groups were injected with a dose of 10 mg/kg dexamethasone subcutaneously for four consecutive days. All groups received either vehicle or drugs daily for four days. Animal weights and pancreatic weights were measured, and oral glucose tolerance test was performed at the end of study. Fasting glucose, triglycerides (TG), total cholesterol (TC), HDL and insulin levels in serum, MDA, and GSH levels in pancreatic tissue were measured and HOMA-IR was calculated. Immunoexpression of apoptosis markers BAX, and BCL2 was measured in pancreatic tissues and BAX/BCL2 ratio was calculated. Histopathological examination of pancreatic tissues was also performed. Pancreatic weight, serum HDL, pancreatic GSH, and BCL2 were decreased while serum glucose, insulin, TG, TC levels, AUC of OGGT, HOMA-IR, pancreatic MDA, BAX, and BAX/BCL2 ratio were increased in IR rats. Histopathological examination showed congestion, vacuolation and hemorrhage in pancreatic islets. These changes were reversed by metformin and the high dose of coriander oil treatments. The obtained activities could be attributed to the presence of 21 volatile compounds, identified by GC-MS. Our study indicates that coriander oil can be used as an adjuvant antihyperglycemic agent in type 2 diabetes. Further experiments are needed to determine the therapeutic dose and the treatment time.
N-Acetylcysteine Inhibits Platelet Function through the Regeneration of the Non-Oxidative Form of Albumin
Authors: Eligini Sonia , Porro Benedetta , Aldini Giancarlo , Colli Susanna , Banfi Cristina
Published: February 2022

N-acetylcysteine (NAC) is able to break down protein disulfides, generating free thiols. This mechanism occurs on mixed disulfides of albumin (HSA) to form mercaptoalbumin (HMA), the main antioxidant species in the plasma. Circulating HSA exists in two main forms: the reduced form (HMA), and the oxidized forms, whose predominant modification is cystenylation (HSA-Cys). Increased levels of oxidized HSA have been detected in several diseases associated with oxidative stress. This study showed that NAC inhibits platelet aggregation by restoring HMA. In addition, the regeneration of HMA by NAC inhibits platelet functions such as intracellular calcium mobilization, reactive oxygen species generation, arachidonic acid metabolites synthesis, and adhesion to the collagen matrix. In our conditions, the exposure of platelets to NAC did not increase GSH levels. However, the inhibition of platelet aggregation was also detected following treatment of platelet-rich plasma with GSH, which, similarly to NAC, reduced HSA-Cys levels. Furthermore, this study showed that cysteine, another compound able to restore HMA by reducing the HSA-Cys content, inhibited platelet aggregation to a similar extent as NAC. The results obtained in this study suggest a new mechanism by which NAC can modulate platelet activation and suggest its possible use as an antiplatelet drug in conditions associated with oxidative stress.
Comparison of Different Approaches Estimating Skeletal Muscle Oxygen Consumption Using Continuous-Wave Near-Infrared Spectroscopy at a Submaximal Contraction Level—A Comparative Study
Authors: Paternoster Florian Kurt , Seiberl Wolfgang
Published: February 2022

Continuous-wave near-infrared spectroscopy (CW-NIRS) is a method used to non-invasively estimate skeletal muscle oxygen consumption (mVO2). Three different signals are provided by CW-NIRS devices: (1) oxygenated hemoglobin (O2Hb); (2) deoxygenated hemoglobin (HHb); and (3) tissue saturation index (TSI). Typically, the signal’s slope is interpreted with respect to high or low mVO2 during a muscle action. What signal (or combination of signals) is used for slope interpretation differs according to what approach is used, and there are several published in literature. It is unclear if resulting mVO2 estimates can be used interchangeably. Hence, this work aimed to compare five commonly used approaches on the same set of CW-NIRS data regarding their agreement in estimated mVO2. A controlled, lab-based study setting was used for this experiment. Data are based on isometric dorsiflexion contractions of 15 subjects at 30% of voluntary maximum torque, at two different ankle angles. CW-NIRS was placed on the m. tibialis anterior and blood flow was occluded. The approaches for mVO2 estimation included calculations based on (1) TSI, (2) the difference between O2Hb and HHb (Hbdiff), (3) the mean of slopes from O2Hb and HHb (Hbmean), (4) the HHb signal, and (5) the O2Hb signal. Linear regression modelling was used to calculate respective slopes (r2 > 0.99). Repeated measures ANOVA identified significant differences between the approaches (p < 0.001, ω2 = 0.258). Post-hoc tests revealed that only TSI vs. Hbmean and Hbdiff vs. HHb gave comparable results (p > 0.271). In addition, Bland–Altman plots showed good accuracy (mean bias ~2%) but low precision (±20%) between the comparisons. Thus, the different approaches to estimate mVO2 cannot be used interchangeably. The results from different studies using different approaches should be compared with caution.
Numerical Investigations for the Two-Phase Flow Structures and Chemical Reactions within a Tray Flue Gas Desulfurization Tower by Porous Media Model
Authors: Tseng Chien-Chou , Li Cheng-Jui
Published: February 2022

The computational cost of the full-scale flue gas desulfurization (FGD) tower with perforated sieve trays is too high, considering the enormous scale ratio between the perforated hole at the sieve tray and the relevant size of the full-scale tower. As a result, the porous media model is used to replace the complex perforated structure at the sieve tray in this study, which has been validated for the measured data for both the small- and full-scale FGD tower. Under a lower inlet gas volume flow rate, the simulation result of the four-tray tower indicates that the uprising gas flow of high SO2 mass fraction can move along the wall of the tower. This region lacks two-phase mixing and, hence, its desulfurization efficiency is similar to that of empty and one-tray towers under the same flow conditions. However, when the gas volume flow rate increases, the liquid column becomes larger because of the stronger inertial of the uprising gas flow. In this situation, the implementation of the sieve tray suppresses the deflection of liquid flow and provides a better mixing within sieve trays, leading to a noticeable increase in desulfurization efficiency. This study provides insightful information for the design guideline for the relevant industries.
Investigation of Fault Effect on Blast-Induced Vibration
Authors: Gonen Alper
Published: February 2022

The propagation of blast-induced vibration velocity in the rock mass varies depending on many parameters. Due to a large number of effective parameters and the variability in the rock mass environment, it is not possible to create a vibration velocity propagation model using all of these parameters. On the other hand, it is important to determine the blast vibration velocity level in urban infrastructure works and mining operations near settlements. Recent studies on the subject have been interested in the determination of blast-induced vibration velocity by the back analysis estimations of advanced statistical approaches and artificial intelligence approaches. However, sudden changes in rock mass properties such as fault zones cause significant errors in the advanced statistical approaches functions used at the level of blast-induced vibration velocity. In this study, the variation of the blast-induced vibration velocities under the influence of the fault zone has been discussed. There is a fault zone along the northwest line of the Quarry boundary. The influence of the fault zone on the blast-induced vibration propagation was determined by comparing the vibration velocities behind the fault zone with the vibration velocities in the non-fault zone. Accordingly, it has been concluded that the fault zone has the potential to create significant differences due to the reflection/refraction of surface waves (Rayleigh and Love waves) in vibration velocity values in areas close to the fault zone have the potential.
A Comparative Assessment of Machine Learning Models for Landslide Susceptibility Mapping in the Rugged Terrain of Northern Pakistan
Authors: Shahzad Naeem , Ding Xiaoli , Abbas Sawaid
Published: February 2022

This study investigated the performances of different techniques, including random forest (RF), support vector machine (SVM), maximum entropy (maxENT), gradient-boosting machine (GBM), and logistic regression (LR), for landslide susceptibility mapping (LSM) in the rugged terrain of northern Pakistan. Initially, a landslide inventory of 200 samples was produced along with an additional 200 samples indicating nonlandslide areas and divided into training (70%) and validation (30%) groups using a stratified loop-based random sampling approach. Then, a geospatial database of 12 possible landslide influencing factors (LIFs) was generated, including elevation, slope, aspect, topographic wetness index (TWI), topographic position index (TPI), distance to drainage, distance to fault, distance to road, normalized difference vegetation index (NDVI), rainfall, land cover/land use (LCLU), and a geological map of the study area. None of the LIFs were redundant for the modeling, as indicated by the multicollinearity test (tolerance > 0.1) and information gain ratio (IGR > 0). We extended the evaluation measures of each algorithm from area-under-the-curve (AUC) analysis to the calculation of performance overall (POA) with the help of precision, recall, F1 score, accuracy (ACC), and Matthew’s correlation coefficient (MCC). The results showed that the SVM was the most promising model (AUC = 0.969, POA = 2669) for the LSM, followed by RF (AUC = 0.967, POA = 2656), GBM (AUC = 0.967, POA = 2623), maxENT (AUC = 0.872, POA = 1761), and LR (AUC = 0.836, POA = 1299). It is important to note that the SVM, RF, and GBM were the top performers, with almost similar accuracy. Thus, each of these could be equally effective for LSM and can be used for risk reduction and mitigation measures in the rugged terrain of Pakistan and other regions with similar topography.
Two-Wavelength Computational Holography for Aberration-Corrected Simultaneous Optogenetic Stimulation and Inhibition of In Vitro Biological Samples
Authors: Schmieder Felix , Büttner Lars , Hanitzsch Tony , Busskamp Volker , Czarske Jürgen W.
Published: February 2022

Optogenetics is a versatile toolset for the functional investigation of excitable cells such as neurons and cardiomyocytes in vivo and in vitro. While monochromatic illumination of these cells for either stimulation or inhibition already enables a wide range of studies, the combination of activation and silencing in one setup facilitates new experimental interrogation protocols. In this work, we present a setup for the simultaneous holographic stimulation and inhibition of multiple cells in vitro. The system is based on two fast ferroelectric liquid crystal spatial light modulators with frame rates of up to 1.7 kHz. Thereby, we are able to illuminate up to about 50 single spots with better than cellular resolution and without crosstalk, perfectly suited for refined network analysis schemes. System-inherent aberrations are corrected by applying an iterative optimization scheme based on Zernike polynomials. These are superposed on the same spatial light modulators that display the pattern-generating holograms, hence no further adaptive optical elements are needed for aberration correction. A near-diffraction-limited spatial resolution is achieved over the whole field of view, enabling subcellular optogenetic experiments by just choosing an appropriate microscope objective. The setup can pave the way for a multitude of optogenetic experiments, in particular with cardiomyocytes and neural networks.
Design of Fiber-Composite/Metal–Hybrid Structures Made by Multi-Stage Coreless Filament Winding
Authors: Mindermann Pascal , Müllner Ralf , Dieringer Erik , Ocker Christof , Klink René , Merkel Markus , Gresser Götz T.
Published: February 2022

Additive manufacturing processes, such as coreless filament winding with fiber composites or laser powder bed fusion with metals, can produce lightweight structures while exhibiting process-specific characteristics. Those features must be accounted for to successfully combine multiple processes and materials. This hybrid approach can merge the different benefits to realize mass savings in load-bearing structures with high mass-specific stiffnesses, strict geometrical tolerances, and machinability. In this study, a digital tool for coreless filament winding was developed to support all project phases by natively capturing the process-specific characteristics. As a demonstration, an aluminum base plate was stiffened by a coreless wound fiber-composite structure, which was attached by additively manufactured metallic winding pins. The geometrical deviations and surface roughness of the pins were investigated to describe the interface. The concept of multi-stage winding was introduced to reduce fiber–fiber interaction. The demonstration example exhibited an increase in mass-specific component stiffness by a factor of 2.5 with only 1/5 of the mass of a state-of-the-art reference. The hybrid design approach holds great potential to increase performance if process-specific features, interfaces, material interaction, and processes interdependencies are aligned during the digitized design phase.
Recognition of the Mental Workloads of Pilots in the Cockpit Using EEG Signals
Authors: Hernández-Sabaté Aura , Yauri José , Folch Pau , Piera Miquel Àngel , Gil Debora
Published: February 2022

The commercial flightdeck is a naturally multi-tasking work environment, one in which interruptions are frequent come in various forms, contributing in many cases to aviation incident reports. Automatic characterization of pilots’ workloads is essential to preventing these kind of incidents. In addition, minimizing the physiological sensor network as much as possible remains both a challenge and a requirement. Electroencephalogram (EEG) signals have shown high correlations with specific cognitive and mental states, such as workload. However, there is not enough evidence in the literature to validate how well models generalize in cases of new subjects performing tasks with workloads similar to the ones included during the model’s training. In this paper, we propose a convolutional neural network to classify EEG features across different mental workloads in a continuous performance task test that partly measures working memory and working memory capacity. Our model is valid at the general population level and it is able to transfer task learning to pilot mental workload recognition in a simulated operational environment.
Preparation and Electrocatalytic Activity of a Cobalt Mixed Nitrogen 3D Carbon Nanostructure @ Carbon Felt toward an All-Vanadium Redox Flow Battery
Authors: Su Jun , Li Zongyang , Hao Longlong , Qin Lilu
Published: February 2022

All-vanadium redox flow batteries (VRFBs), with good operation flexibility and scalability, have been regarded as one of the most competitive substitutes for large-scale energy storage. However, because of the low electrochemical activities of traditional electrodes such as carbon felt and graphite felt, they will impede the interfacial charge transfer processes and decrease the efficiencies of VRFBs. In this work, Co-MOF (ZIF-67) was prepared as a precursor, and a cobalt mixed nitrogen 3D carbon nanostructure and carbon felt (Co-CN@CF) was prepared by chemical reaction and used in VRFBs as electrodes. With the unique structure and high efficiency catalyst on the carbon felt, the Co-CN@CF exhibited excellent electrochemical activity toward the VO2+/VO2+ redox couple in the VRFB, with an average cell voltage efficiency (VE) of 86% and an energy efficiency (EE) of 82% at 80 mA cm−2, which was increased by more than 10% compared with the traditional carbon felt. VRFBs with a Co-CN@CF electrode also showed much better long-term stability (over 1000 cycles) compared with the battery with a pristine CF electrode.
Visible-Light-Active Zn–Fe Layered Double Hydroxide (LDH) for the Photocatalytic Conversion of Rice Husk Extract to Value-Added Products
Authors: Saeed Muhammad , Zafar Muhammad , Razzaq Abdul , Khan Shenawar Ali , Khan Zakir , Kim Woo Young
Published: February 2022

One of the major causes of excess CO2 in the atmosphere is the direct burning of biomass waste, which can be obviated by the photocatalytic biomass conversion to useful/valuable chemicals/fuels, a sustainable and renewable approach. The present research work is focused on the development of a novel Zn–Fe LDH by a simple co-precipitation method and its utilization for the photocatalytic conversion of a rice husk extract (extracted from rice husk by means of pyrolysis) to value-added products. The synthesized, pure Zn–Fe LDH was characterized by various analytical techniques such as XRD, SEM, FTIR, and UV–Visible DRS spectroscopy. The rice husk extract was converted in a photocatalytic reactor under irradiation with 75 W white light, and the valued-added chemicals were analyzed by gas chromatography–mass spectrometry (GC–MS). It was found that the compounds in the rice husk extract before the photocatalytic reaction were mainly carboxylic acids, phenols, alcohols, alkanes (in a small amount), aldehydes, ketones, and amines. After the photocatalytic reaction, all the carboxylic acids and phenols were completely converted into alkanes by complex reactions. Hence, photocatalytic biomass conversion of a rice husk extract was successfully carried out in the present experimental work, opening new avenues for the development of related research domains, with a great potential for obtaining an alternate fuel and overcoming environmental pollution.
Simple and Robust Log-Likelihood Ratio Calculation of Coded MPSK Signals in Wireless Sensor Networks for Healthcare
Authors: Xie Bo , Ma Congfang , Li Haiqiong , Zhang Gaoyuan , Han Congzheng
Published: February 2022

The simple and robust log-likelihood ratio (LLR) computation of coded Multiple Phase Shift Keying (MPSK) signals in Wireless Sensor Networks (WSNs) is considered under both phase noncoherent and Rayleigh fading channels for healthcare applications. We first simplify the optimal LLR for phase noncoherent channel, the estimation of the instantaneous channel state information (CSI) for both the fading amplitude and the additive white Gaussian noise (AWGN) is successfully avoided, and the complexity-intensive process for zero-order Bessel function of the first kind is also perfectly eliminated. Furthermore, we also develop the simplified LLR under Rayleigh fading channel. Correspondingly, the variance estimation for both AWGN and the statistical characteristic of the fading amplitude is no longer required, and the complicated process for implementation of the exponential function is also successfully avoided. Compared to the calculation of optimal LLR with full complexity, the proposed method is implementation-friendly, which is practically desired for energy-limited WSNs. The simulations are developed in the context of low-density parity-check (LDPC) codes, and the corresponding results show that the detection performance is extremely close to that of the full-complexity LLR metrics. That is, the performance degradation is efficiently prevented, whereas complexity reduction is also successfully achieved.
Exact and Inexact Lifting Transformations of Nonlinear Dynamical Systems: Transfer Functions, Equivalence, and Complexity Reduction
Authors: Gosea Ion Victor
Published: February 2022

In this work, we deal with the problem of approximating and equivalently formulating generic nonlinear systems by means of specific classes thereof. Bilinear and quadratic-bilinear systems accomplish precisely this goal. Hence, by means of exact and inexact lifting transformations, we are able to reformulate the original nonlinear dynamics into a different, more simplified format. Additionally, we study the problem of complexity/model reduction of large-scale lifted models of nonlinear systems from data. The method under consideration is the Loewner framework, an established data-driven approach that requires samples of input–output mappings. The latter are known as generalized transfer functions, which are appropriately defined for both bilinear and quadratic-bilinear systems. We show connections between these mappings as well as between the matrices of reduced-order models. Finally, we illustrate the theoretical discussion with two numerical examples.
Influence of Wood Properties and Building Construction on Energy Demand, Thermal Comfort and Start-Up Lag Time of Radiant Floor Heating Systems
Authors: Ruiz-Pardo Álvaro , Rodríguez Jara Enrique Ángel , Conde García Marta , Ríos José Antonio Tenorio
Published: February 2022

Radiant floor heating is becoming increasingly popular in cold climates because it delivers higher comfort levels more efficiently than conventional systems. Wood is one of the surface coverings most frequently used in radiant flooring, despite the widely held belief that in terms of thermal performance it is no match for higher conductivity materials if a high energy performance is intended. Given that the highest admissible thermal resistance for flooring finishes or coverings is generally accepted to be 0.15 m2K/W, wood would appear to be a scantly appropriate choice. Nonetheless, the evaluation of the thermal performance of wooden radiant floor heating systems in conjunction with the building in terms of energy demand, thermal comfort, and start-up period, has been insufficiently explored in research. This has led to the present knowledge gap around its potential to deliver lower energy consumption and higher thermal comfort than high-thermal-conductivity materials, depending on building characteristics. This article studies the thermal performance of wood radiant floors in terms of three parameters: energy demand, thermal comfort, and start-up lag time, analysing the effect of wood properties in conjunction with building construction on each. An experimentally validated radiant floor model was coupled to a simplified building thermal model to simulate the performance of 60 wood coverings and one reference granite covering in 216 urban dwellings differing in construction features. The average energy demand was observed to be lower in the wood than in the granite coverings in 25% of the dwellings simulated. Similarly, on average, wood lagged behind granite in thermal comfort by less than 1 h/day in 50% of the dwellings. The energy demand was minimised in a significant 18% and thermal comfort maximised in 14% of the simulations at the lowest thermal conductivity value. The vast majority of the wooden floors lengthened the start-up lag time relative to granite in only 30 min or less in all the dwellings. Wood flooring with the highest thermal resistance (even over the 0.15 m2K/W cited in standard EN 1264-2) did not significantly affect the energy demand or thermal comfort. On average, wood flooring lowered energy demand by 6.4% and daily hours of thermal comfort by a mere 1.6% relative to granite coverings. The findings showed that wood-finished flooring may deliver comparable or, in some cases, higher thermal performance than high-conductivity material coverings, even when their thermal resistance is over 0.15 m2K/W. The suggestion is that the aforementioned value, presently deemed the maximum admissible thermal resistance, may need to be revised.
Quasi-Density of Sets, Quasi-Statistical Convergence and the Matrix Summability Method
Authors: Masarova Renata , Visnyai Tomas , Vrabel Robert
Published: February 2022

In this paper, we define the quasi-density of subsets of the set of natural numbers and show several of the properties of this density. The quasi-density dp(A) of the set A⊆N is dependent on the sequence p=(pn). Different sequences (pn), for the same set A, will yield new and distinct densities. If the sequence (pn) does not differ from the sequence (n) in its order of magnitude, i.e., limn→∞pnn=1, then the resulting quasi-density is very close to the asymptotic density. The results for sequences that do not satisfy this condition are more interesting. In the next part, we deal with the necessary and sufficient conditions so that the quasi-statistical convergence will be equivalent to the matrix summability method for a special class of triangular matrices with real coefficients.
Intrinsic Defects, Diffusion and Dopants in AVSi2O6 (A = Li and Na) Electrode Materials
Authors: Kuganathan Navaratnarajah
Published: February 2022

The alkali metal pyroxenes of the AVSi2O6 (A = Li and Na) family have attracted considerable interest as cathode materials for the application in Li and Na batteries. Computer modelling was carried out to determine the dominant intrinsic defects, Li and Na ion diffusion pathways and promising dopants for experimental verification. The results show that the lowest energy intrinsic defect is the V–Si anti-site in both LiVSi2O6 and NaVSi2O6. Li or Na ion migration is slow, with activation energies of 3.31 eV and 3.95 eV, respectively, indicating the necessity of tailoring these materials before application. Here, we suggest that Al on the Si site can increase the amount of Li and Na in LiVSi2O6 and NaVSi2O6, respectively. This strategy can also be applied to create oxygen vacancies in both materials. The most favourable isovalent dopants on the V and Si sites are Ga and Ge, respectively.
Automatic Segmentation of Monofilament Testing Sites in Plantar Images for Diabetic Foot Management
Authors: Costa Tatiana , Coelho Luis , Silva Manuel F.
Published: February 2022

Diabetic peripheral neuropathy is a major complication of diabetes mellitus, and it is the leading cause of foot ulceration and amputations. The Semmes–Weinstein monofilament examination (SWME) is a widely used, low-cost, evidence-based tool for predicting the prognosis of diabetic foot patients. The examination can be quick, but due to the high prevalence of the disease, many healthcare professionals can be assigned to this task several days per month. In an ongoing project, it is our objective to minimize the intervention of humans in the SWME by using an automated testing system relying on computer vision. In this paper we present the project’s first part, constituting a system for automatically identifying the SWME testing sites from digital images. For this, we have created a database of plantar images and developed a segmentation system, based on image processing and deep learning—both of which are novelties. From the 9 testing sites, the system was able to correctly identify most 8 in more than 80% of the images, and 3 of the testing sites were correctly identified in more than 97.8% of the images.
Sex- and Age-Related Dynamic Changes of the Macroelements Content in the Femoral Bone with Hip Osteoarthritis
Authors: Dąbrowski Mikołaj , Zioła-Frankowska Anetta , Frankowski Marcin , Daroszewski Przemysław , Szymankiewicz-Szukała Agnieszka , Kubaszewski Łukasz
Published: February 2022

Background: The content of macroelements in bones varies with age and depends on sex. The aim of the study was to evaluate the content of macroelements and its correlation with age and sex in the femoral bone obtained during total hip arthroplasty. Methods: In the 86 patients, the content of macroelements (Ca, P, Mg, and Na) in the femoral head and neck (cancellous and cortical bone) was assessed by means of the inductively coupled plasma optical emission spectrometry analytical technique (ICP-OES). Results: There was a decrease in the content of macroelements in the cortical bone with age in the women in the 51–60 years (statistically significant: −0.59 for Ca, −0.65 for P) and over 70 years age groups (correlation not statistically significant: −0.29 for Ca, −0.38 for P). A significant decrease in the content of macroelements in the cortical bone was found in men over 70 years of age. Conclusions: Patterns of increased loss of macronutrients (Ca, P, and Mg) in the femoral neck (cortical bone) were demonstrated in the following patients with osteoarthritis: women aged 51–60 years and patients of both sexes over 70 years of age.
Modeling Vaccine Efficacy for COVID-19 Outbreak in New York City
Authors: Demongeot Jacques , Griette Quentin , Magal Pierre , Webb Glenn
Published: February 2022

In this article we study the efficacy of vaccination in epidemiological reconstructions of COVID-19 epidemics from reported cases data. Given an epidemiological model, we developed in previous studies a method that allowed the computation of an instantaneous transmission rate that produced an exact fit of reported cases data of the COVID-19 outbreak. In this article, we improve the method by incorporating vaccination data. More precisely, we develop a model in which vaccination is variable in its effectiveness. We develop a new technique to compute the transmission rate in this model, which produces an exact fit to reported cases data, while quantifying the efficacy of the vaccine and the daily number of vaccinated. We apply our method to the reported cases data and vaccination data of New York City.