bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Study of Elevated Service Reservoir with Water Baffles Under Seismic Loading
Authors: Pradeep S , Anuwar Husain S , Ansari K
Published: April 2021

Around the world earthquakes occur often causing some serious damages to property and life. Earthquakes weaken the structure and cause it to fail suddenly. Elevated Water tanks are such structures which have heavier mass suspended at a height supported on slender staging. When earthquake is induced in the tanks, it generates wave sloshing, the motion of the water induced due to seismic excitation. This sloshing of the water inside the tank will move in relative direction the seismic excitation causing structural instability. The water inside the tank will also act as tuned liquid mass damper and absorbs most of the energy created during seismic excitation. In this paper we have analysed various arrangement of baffle walls inside the tank in order to determine the stresses and displacements induced by the sloshing motion of the water tank. The water inside the tank will also act as tuned liquid mass damper where it will reduce the energy generated due to seismic excitation. During sloshing motion, there is an increase in lateral pressure applied over the tank walls which has adverse effect on the displacement of the system. The displacement of the system increases due to sloshing activity. By providing baffle walls we can reduce this displacement induced due to sloshing and thereby reduce the stresses generated on the supporting structure. From this analytical work the latter said was very evident.
Study on the heat transfer characteristics of Al2O3-CuO/Water hybrid nanofluids in a shell and rotating wavy tube heat exchanger
Authors: Vinoth R. , Sachuthananthan B. , Vadivel A. , Kaleeswaran P.
Published: April 2021

The present study focuses on heat transfer and characteristics of fluid flow behaviour of a rotating wavy tube HEX using water and Al2O3-CuO/Water (0.3%) hybrid nanofluid as coolants. The shell and wavy tube were modelled in CATIA with a tube diameter of 9.3mm and shell diameter of 140mm. The heat transfer area of the rotating tube heat exchanger is 0.0476m2. Water is utilized as the hot fluid inside the shell and Al2O3-CuO/Water (0.3%) Hybrid nanofluid was used in tube side. The rotating wavy tube heat exchanger was fabricated by VMC and CNC machining process and tube is maintained at the speed of 57.5 rpm. The experiment was carried out by varying tube side mass flow rate and shell mass flow rate was kept constant. Experimental study reveals that the heat transfer rate of the rotating tube was higher when compared to the fixed tube by 10.5% when pure water is used. Similarly when Al2O3-CuO/Water (0.3%) Hybrid nanofluid is made to flow in tube side; the heat transfer rate was considerably higher than pure water by 9.15%. This is due to wavy rotating tube helps to increase the turbulence inside tube and shell side resulting in better heat transfer and a comparable pressure drop. So, this heat exchanger is found to be an optimal design and can be used in various applications.
A Study on Flexible Manufacturing Systems using Petri Net Reduction
Authors: Padma V.
Published: April 2021

Petrinets are the suitable tool for modeling and analysis of discrete event systems. The effective methods of analyzing the discrete event systems (DES) are exhibited by Petri nets. The entire structure of the system is mathematically expressed using Petrinets and also all the properties are analysed by different methods. The properties of Petrinets are different in various systems, a Flexible Manufacturing System (FMS) requires production activities in which raw materials, energy, labour, and equipment are combined together in the modification process for the production of good quality goods.” The word “flexible” explains the capability of the system to relate productively to make changes in the system. These changes can be internal failure of the system or classification problems such as a sample or external changes in the structure of the model as well as demand for the process. The inherent limitations such as undecidable properties, complexity in checking, automatic verification of the modeled system are existing in FMS. This paper explains a study on FMS using Petri net reduction. A PN underlies event structures with casuality and compatibility relations. Partial order methods and reduction methods reduce the complexity of constructing the reachability graph. The determination of PN system through reduction methods in recent years focused by many researchers. The significance of reduction methods are highlighted to execute the faster analysis of a system. Instead of coverability trees and the graphical representation the incidence matrix of the PNs are used for the reduction methods. Reduction methods are used to simplify large scale PNs into “equivalent” smaller nets. Boundedness, liveness, simplification of implicit places, shared resources and elimination of self-loops are checked though equivalent smaller nets. The structure of FMS is preserved.
Experimental study on alcohol fumigation in a CI engine energized with waste cooking oil
Authors: Praveena V. , Akshaykumar U , Nishad T
Published: April 2021

Consumption of fossil fuels rose drastically over the global level. Replacement for fossil fuels is necessary, since every year the automobile production is increasing the consumption of fossil fuels like petrol and diesel in rapid phase. Although strict vehicle emission control norms like Euro5, BS6 etc are implemented in different countries, the emission of harmful gas like Hydrocarbons (HC), Carbon monoxide (CO), NOx, VOCs etc have not been reduced to greater extent. So for the replacement of fossil fuels, a suitable alternative fuel which is a combination of waste cooking oil with hexanol added to it by fumigation technique is selected which would reduce the toxic emissions released by automobiles. The aim of this paper is to study the effect of adding hexanol at different concentration by fumigation method on the performance and emission characteristics of a CI engine. NOx emission reduces by 21% and smoke opacity by 28%. BTE is negatively affected by the fumigation mode 2 and reduces to 27.2%. From the emission point of view, the fumigation method proves to be beneficial while running a CI engine with waste cooking oil.
An effective approach for the solution of fully fuzzy transportation problems
Authors: Krishnaveni G. , Ganesan K.
Published: April 2021

In this paper, a simple method is proposed to solve fully fuzzy transportation problems whose parameters are triangular fuzzy numbers. We express all the triangular fuzzy numbers in their parametric form, applying the new arithmetic and new ranking function and solve the fully fuzzy transportation problems without converting in its crisp form. A numerical example is provided to illustrate the theory developed in this article.
Performance and emission characteristic studies on CRDi diesel engine fuelled with jatropha green diesel
Authors: Suresh Pelluru , Mathan Raj V
Published: April 2021

The Use of the fossil fuel power increments regular that leads towards the consumption of fossil fuel along with emissions from diesel or pressure ignition engine contributes development of disease on individuals, thus global government’s arrangements orders call for emissions decline. The expanding comprehension of the above made environmentally agreeable and monetary invaluable resource of green diesel gas become more alluring lately. As a rule, Biodiesel and bioethanol are acknowledged because of the reality planned sustainable transportation fuels. Fatty substances are formed related with the long and direct hydrocarbon spine having a decreased volume of oxygen when contrasted and sugar, starch, and biomass that is cellulosic. It truly is, thusly, thought to be the engaging biomass for assembling hydrocarbon biofuels. Pyrolysis, synergist breaking, and hydro de oxygenation (HDO) are achievable channels for assembling diesel-range hydrocarbons from fatty oils, regularly comprehended as ‘green diesel’. Among these methodology, HDO could be the usually acknowledged course attributable to the high return of green diesel. Also, this course is associated with negligible absence of unsaturated fat’s carbons as unpredictable hydrocarbons. This course further offers the probability of co-handling of fatty substances with raw petroleum parts inside the current hydrotreatment item. in the daily life utilizatation of the fossil fuel
Effect of injection timing on alcohol-biodiesel-diesel ternary blends in a CI engine
Authors: Praveena V. , Sharma Udayan , Prajapati Sanjay Kumar
Published: April 2021

The major concerns of using Jojoba oil in CI engines is its high viscosity, low volatility, and high NOx formation. In this work, an analysis of the emission parameters and efficiency of a jojoba biodiesel-fuelled engine is carried out. This research study investigates the impacts of the addition of higher order alcohols with diesel fuel on the performance and emission parameters of CI engine working with diesel-jojoba oil methyl ester blend. 5% and 10% by volume of n-butanol is combined with B20 blend of jojoba oil methyl ester. The experiment is divided in two steps, firstly, the optimum combination of alcohol with biodiesel is evaluated based on the BTE and emission parameters. Secondly, the effect of varying the injection timing from 21°, 23° and 25° BTDC for the alcohol blends of diesel-biodiesel blends are studied. BTE increases by 4.5% for B20+10% butanol and NO emission decreases by 23%. Other emissions are facing a significant drop except HC emissions. Delayed injection timing of 21° BTDC reduces NO emission further by 18.4%. The findings prove that adding n-butanol, oxygenated fuel could enhance the viscosity issue of jojoba oil methyl ester and the mixtures as well resulting in an enhancement in their performance parameters.
Experimental Investigation of Heat Transfer of Concentric Triple Pipe Heat Exchanger Coupled with Blossom Fins.
Authors: Arulkumar S , Mathanraj V
Published: April 2021

The present work describes the principle techniques of industrial importance as it deals with heat transfer analysis of concentric triple pipe heat exchanger employing blossom fins. Findings indicate that the use of fin arrangement is advantageous to enhance the performance of heat exchanger, LMTD, over all heat transfer and effectiveness is found to be increased. The additional fins improve the heat transfer by providing a larger area for heat transfer area per unit length of the exchanger. The net heat transfer, overall heat transfer, efficiency and effectiveness were calculated and compared for all the flow patterns and Counter flow 3 was found to have the best results among the flow patterns with the maximum heat transfer, heat transfer coefficient, efficiency and effectiveness being 1642.09 watts, 1842.07 w/m2k, 0.57896 and 0.73 respectively.
Composite Keyword Based Search Over Data on Remote Information
Authors: Senthil Kumar G. , Shiny angel T.S , Vijayakumar K. , Chamoli Akhilesh , Kejriwal Sarang , Snehalatha N.
Published: April 2021

Majority of data owners have moved their services to the cloud servers. Members of any organization can access data from the cloud by using keyword-based search. Being based on Boolean keyword matching system or semantic search they are unable to provide accurate search results as well as unable to understand misspelled keywords. With the existing searching mechanisms like keyword search in place, the search results are often slow and they result in missing of information and produce in accurate results. In this paper, a K-Gram based approach is proposed to improve the search efficiency. Using this approach, the words are divided in to groups and then they are identified by the corresponding Indexes. This proposed approach can improvise secure and efficient retrieval of information.
A Comparative Study on Aerodynamic Drag Reduction of a Blunt Nose Body using Aerospike and Aerodisk – Numerical Approach
Authors: Senthilkumar S , Mudholkar Aarohi Anmol , Sanjay K J
Published: April 2021

A spike attached to a hemispherical body drastically changes its flow field and influences aerodynamic drag in supersonic and hypersonic flow. It is, therefore a potential candidate for drag reduction of a future high-speed vehicle. The effect of spike nose configuration and angle of attack on the reduction of drag is studied. The studies show that the aerodisk is superior to the aerospike. The aerodisk of appropriate length, diameter and nose configuration may have the capability for the drag reduction. Design criteria is studied and the aerodisk attached to the blunt nose body are designed using CATIA. Numerical solutions are obtained using a commercial CFD software ANSYS-Fluent. Flow observations on the blunt body with a conical, hemispherical aerodisk and flat-faced aerodisk are carried out at Mach number of 2. The flow fields show different flow features between the conical spike, the hemispherical aerodisk and the flat-faced aerodisk. The effects of the aerospike and aerodisk on the lift and drag coefficient are studied. Finally, it is found that A forward-facing spike attached to a hemispherical body alters significantly the structure of the flow field and serves to reduce drag by the formation of a recirculation region around the stagnation point of the blunt body. The flow field, immediately behind the aerodisk shows a complex flow field due to back-disk geometry as compared to the conical spike. To take advantage of the forward-facing spike for more efficient drag reduction, the reattachment point of the shear layer on the body should be moved backward by choosing the optimal spike length with suitable geometrical configuration of the nose.
Parametric optimization of wire-EDM machining of nimonic 80a using response surface methodology
Authors: Senkathir  , Manoj Samson R , Nirmal R , Ranjith R
Published: April 2021

Wire electrical discharge machining (WEDM) can machine hard materials with ease. Nimonic 80A is hard and high temperature resistant material which is widely used in the power plant boiler tubes, gas turbines, exhaust valves. This work involves in developing a models for correlating the dependency of various WEDM process parameters of Nimonic 80A like gap voltage, duty factor and feed rate on response factors like rate of material removal (MRR), wire wear ratio and surface roughness (SR). This experiment was carried out on the basis of Response Surface Methodology (RSM) and Grey Relational Analysis (GRA). Using the design of experiments, 20 experiments were conducted. The duty factor of 0.8771, gap voltage 17V and wire feed rate of 17m/min was found to be the optimized process parameter while machining Nimonic 80A.
Design of Low cost Data Acquisition Circuit with Feature Extraction
Authors: Archana R , Rajalakshmi T , Vijay Sai P
Published: April 2021

Single channel Electrooculogram (EOG) data acquisition system is designed to observe the patterns of signal to confirm the presence of disease or disorder. Tracking the movements of the eyes are done for controlling applications such as wheelchair control, blink detection, word speller, etc for people with complete or partial disability. With the help of signals generated from the eyes, the pattern is studied. This paper lay upon designing of highly precised instrumentation part of single channel EOG with miniaturized circuit and low cost. Different amplifiers are used to remove noise and increase the gain of the signal. Arduino UNO will read the EOG signal as analog input and the signal is recorded using PLX DAQ software which is interfaced with Arduino. The EOG signal is taken for 15 adults and it is tested for the working of the circuit. The signal is further amplified and filtered using MATLAB software and thus the eye movements are visualized. The set of basic mathematical feature are derived for the filtered signal which can be used for future applications for differentiating various eye problems.
Reduction of Carbon Dioxide Emission from Diesel Engine Fuelled with Plastic Pyrolytic Oil Using Modified Charcoals
Authors: Sathish Kumar R. , Balaji G. , Cheralathatn M. , Sureshkumar K.
Published: April 2021

Carbon dioxide is one of the greenhouse gases majorly contributing to the global warming and greenhouse effects. Combustion of fossil fuels such as coal, petroleum products and natural gas for power production, transportation and industrial applications produce maximum amount of carbon dioxide. Hence, reduction of CO2 emission is mandated to avoid additional add on to the atmosphere and control global warming. A new low cost carbon trapper using modified charcoals has been designed and tested in a stationary diesel engine for the reduction of carbon dioxide emission and results were reported in this article. Normal wooden charcoal was produced and impregnated with NaOH and KOH. These two modified charcoals, Normal wooden charcoal and commercially purchased activated charcoal were testes individually and compared with each other. Also the effect of amount of different charcoals at 100 grams, 200 grams and 300 grams on carbon dioxide reduction were also tested. The potassium hydroxide (KOH) impregnated wooden charcoal with 300 grams mass shows the best result of 63.92% CO2 reduction at 75% engine load and sodium hydroxide (NaOH) impregnated charcoal shows 62.89% reduction in CO2 at the same engine load due to increased adsorption along with absorption and high porosity.
Experimental analysis of wind turbine of high-speed air available from industrial exhaust of rectangular flat blade
Authors: Sathiyamoorthy K. , Rajendran R. , Chandra Sekhar S
Published: April 2021

Wind energy iscontributing to the majority of the energy production in the renewable energy sectors. Currently more research work is being carried out in the Vertical Axis Wind Turbine technology. It is a turbine in which the axis of rotation of rotor is perpendicular to the ground and also perpendicular to the wind direction. Literature is available for the wind blades which have the special curves such as NACA profile etc., the drawback of aerodynamics blades is themanufacturing difficulties due to the complex profile which leads to the high cost of blade manufacturing. The best choice of the profile to provide a better solution is flat rectangular blade. The dimensions of the rectangular blade are: blade height-176mm, rotor diameter-110mm, blade width-12mm, blade side width-4mm and has a cross section of 12*4mm This paper deals with the study on the effect of the rectangular flat plate under the high wind velocity. A 2D model was developed using Solid works software. CFD Analysis was performed to determine the wind velocity which gives a better performance. A Prototype was built to perform the experimental analysis, and to correlate the results obtained in the CFD analysis for validation and verification. The results show that the maximum coefficient performance of 0.3 is achieved with Tip Speed Ratio (TSR) ranging from 2 to 4. This study on the dynamics of the wind blade may lead to the advancement of the blade structure and thereby generating more power. This type of flat blade can be used in the heat recovery system in the industrial exhaust where high speed wind is available. The another new thing is discussed here using the IoT techniques to measure the torque for every azimuth angle in real time experiment.
Analysis of the impact of mining and geological conditions in longwalls on the introduction of pressure monitoring for powered roof supports
Authors: Trzop K , Szurgacz D , Zhironkin S , Kasprusz A
Published: April 2021

Polska Grupa Górnicza has analysed the longwalls in its mines where powered roof supports should be subject to pressure monitoring. The main goal was to increase the safety of people working in the longwall. The scope also included the economic improvement of active longwalls in terms of stoppages caused by roof fall or possible tremors. The analysis, carried out in this regard, allowed strategic longwalls to be selected from the individual mines of Polska Grupa Górnicza. The paper describes mining and geological conditions in the longwalls, where monitoring is carried out, with particular attention paid to potential tremors. The paper discusses the scope and use of powered roof supports in longwalls. The research team selected the pressure monitoring system as the most important parameter of work of the powered roof support. The paper also presents the results of an analysis carried out on the implementation of the system. A survey was conducted among the employees regarding the relevance of the monitoring system. The analyses results were used to recommend the directions of further actions related to a development of the system for monitoring the supporting parameters of the powered roof support systems.
The Use of Active Comparators in Self-Controlled Designs
Authors: Hallas Jesper , Whitaker Heather , Delaney Joseph A , Cadarette Suzanne M , Pratt Nicole , Maclure Malcolm
Published: April 2021

For self-controlled studies of medication-related effects, time-varying confounding by indication can occur if the indication varies over time. We describe how active comparators might mitigate such bias, using an empirical example. Approaches to using active comparators are described for case-crossover design, case-time-control design, self-controlled case-series, and sequence symmetry analyses. In the empirical example, we used Danish data from 1996–2018 to study the association between penicillin and venous thromboembolism (VTE), using roxithromycin, a macrolide antibiotic, as comparator. Upper respiratory infection is a transient risk factor for VTE, thus representing time-dependent confounding by indication. Odds ratios for case-crossover analysis were 3.35 (95% confidence interval: 3.23, 3.49) for penicillin and 3.56 (95% confidence interval: 3.30, 3.83) for roxithromycin. We used a Wald-based method or an interaction term to estimate the odds ratio for penicillin with roxithromycin as comparator. These 2 estimates were 0.94 (95% confidence interval: 0.87, 1.03) and 1.03 (95% confidence interval: 0.95, 1.13). Results were similar for the case-time-control analysis, but both the self-controlled case-series and sequence symmetry analysis suggested a weak protective effect of penicillin, seemingly explained by VTE affecting future exposure exclusively for penicillin. The strong association of antibiotics with VTE suggests presence of confounding by indication. Such confounding can be mitigated by using an active comparator.
Invited Commentary: New Directions in Machine Learning Analyses of Administrative Data to Prevent Suicide-Related Behaviors
Authors: Bossarte Robert M , Kennedy Chris J , Luedtke Alex , Nock Matthew K , Smoller Jordan W , Stokes Cara , Kessler Ronald C
Published: April 2021

This issue contains a thoughtful report by Gradus et al. (Am J Epidemiol. 2021;190(12):2517–2527) on a machine learning analysis of administrative variables to predict suicide attempts over 2 decades throughout Denmark. This is one of numerous recent studies that document strong concentration of risk of suicide-related behaviors among patients with high scores on machine learning models. The clear exposition of Gradus et al. provides an opportunity to review major challenges in developing, interpreting, and using such models: defining appropriate controls and time horizons, selecting comprehensive predictors, dealing with imbalanced outcomes, choosing classifiers, tuning hyperparameters, evaluating predictor variable importance, and evaluating operating characteristics. We close by calling for machine-learning research into suicide-related behaviors to move beyond merely demonstrating significant prediction—this is by now well-established—and to focus instead on using such models to target specific preventive interventions and to develop individualized treatment rules that can be used to help guide clinical decisions to address the growing problems of suicide attempts, suicide deaths, and other injuries and deaths in the same spectrum.
StackIL6: a stacking ensemble model for improving the prediction of IL-6 inducing peptides
Authors: Charoenkwan Phasit , Chiangjong Wararat , Nantasenamat Chanin , Hasan Md Mehedi , Manavalan Balachandran , Shoombuatong Watshara
Published: April 2021

The release of interleukin (IL)-6 is stimulated by antigenic peptides from pathogens as well as by immune cells for activating aggressive inflammation. IL-6 inducing peptides are derived from pathogens and can be used as diagnostic biomarkers for predicting various stages of disease severity as well as being used as IL-6 inhibitors for the suppression of aggressive multi-signaling immune responses. Thus, the accurate identification of IL-6 inducing peptides is of great importance for investigating their mechanism of action as well as for developing diagnostic and immunotherapeutic applications. This study proposes a novel stacking ensemble model (termed StackIL6) for accurately identifying IL-6 inducing peptides. More specifically, StackIL6 was constructed from twelve different feature descriptors derived from three major groups of features (composition-based features, composition-transition-distribution-based features and physicochemical properties-based features) and five popular machine learning algorithms (extremely randomized trees, logistic regression, multi-layer perceptron, support vector machine and random forest). To enhance the utility of baseline models, they were effectively and systematically integrated through a stacking strategy to build the final meta-based model. Extensive benchmarking experiments demonstrated that StackIL6 could achieve significantly better performance than the existing method (IL6PRED) and outperformed its constituent baseline models on both training and independent test datasets, which thereby support its excellent discrimination and generalization abilities. To facilitate easy access to the StackIL6 model, it was established as a freely available web server accessible at http://camt.pythonanywhere.com/StackIL6. It is anticipated that StackIL6 can help to facilitate rapid screening of promising IL-6 inducing peptides for the development of diagnostic and immunotherapeutic applications in the future.
Multi-view Multichannel Attention Graph Convolutional Network for miRNA–disease association prediction
Authors: Tang Xinru , Luo Jiawei , Shen Cong , Lai Zihan
Published: April 2021

Motivation: In recent years, a growing number of studies have proved that microRNAs (miRNAs) play significant roles in the development of human complex diseases. Discovering the associations between miRNAs and diseases has become an important part of the discovery and treatment of disease. Since uncovering associations via traditional experimental methods is complicated and time-consuming, many computational methods have been proposed to identify the potential associations. However, there are still challenges in accurately determining potential associations between miRNA and disease by using multisource data.

Results: In this study, we develop a Multi-view Multichannel Attention Graph Convolutional Network (MMGCN) to predict potential miRNA–disease associations. Different from simple multisource information integration, MMGCN employs GCN encoder to obtain the features of miRNA and disease in different similarity views, respectively. Moreover, our MMGCN can enhance the learned latent representations for association prediction by utilizing multichannel attention, which adaptively learns the importance of different features. Empirical results on two datasets demonstrate that MMGCN model can achieve superior performance compared with nine state-of-the-art methods on most of the metrics. Furthermore, we prove the effectiveness of multichannel attention mechanism and the validity of multisource data in miRNA and disease association prediction. Case studies also indicate the ability of the method for discovering new associations.
Resilience function uncovers the critical transitions in cancer initiation
Authors: Li Yan , Zhang Shao-Wu
Published: April 2021

Considerable evidence suggests that during the progression of cancer initiation, the state transition from wellness to disease is not necessarily smooth but manifests switch-like nonlinear behaviors, preventing the cancer prediction and early interventional therapy for patients. Understanding the mechanism of such wellness-to-disease transitions is a fundamental and challenging task. Despite the advances in flux theory of nonequilibrium dynamics and ‘critical slowing down’-based system resilience theory, a system-level approach still lacks to fully describe this state transition. Here, we present a novel framework (called bioRFR) to quantify such wellness-to-disease transition during cancer initiation through uncovering the biological system’s resilience function from gene expression data. We used bioRFR to reconstruct the biologically and dynamically significant resilience functions for cancer initiation processes (e.g. BRCA, LUSC and LUAD). The resilience functions display the similar resilience pattern with hysteresis feature but different numbers of tipping points, which implies that once the cell become cancerous, it is very difficult or even impossible to reverse to the normal state. More importantly, bioRFR can measure the severe degree of cancer patients and identify the personalized key genes that are associated with the individual system’s state transition from normal to tumor in resilience perspective, indicating that bioRFR can contribute to personalized medicine and targeted cancer therapy.
Obstruction of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice
Authors: Chen Yunxia , Zhang Xiaorong , Liu Zhihui , Yang Jiacai , Chen Cheng , Wang Jue , Yang Zengjun , He Lei , Xu Pengcheng , Hu Xiaohong , Luo Gaoxing , He Weifeng
Published: April 2021

Background

Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury. However, the systematic and detailed evaluation of the scald burn injury, including second-degree deep scald (SDDS) and third-degree scald (TDS), is still unclear. The present study aims to analyze the wound-healing speed, the formation of granulation tissue, and the healing quality after cutaneous damage.

Methods

In order to assess SDDS and TDS, the models of SDDS and TDS were established using a scald instrument in C57BL/6 mice. Furthermore, an excisional wound was administered on the dorsal surface in mice (Cut group). The wound-healing rate was first analyzed at days 0, 3, 5, 7, 15 and 27, with the Cut group as a control. Then, on the full-thickness wounds, hematoxylin and eosin (H&E) staining, Masson staining, Sirius red staining, Victoria blue staining and immunohistochemistry were performed to examine re-epithelialization, the formation of granulation tissue, vascularization, inflammatory infiltration and the healing quality at different time points in the Cut, SDDS and TDS groups.

Results

The presented data revealed that the wound-healing rate was higher in the Cut group, when compared with the SDDS and TDS groups. H&E staining showed that re-epithelialization, formation of granulation tissue and inflammatory infiltration were greater in the Cut group, when compared with the SDDS and TDS groups. Immunohistochemistry revealed that the number of CD31, vascular endothelial growth factor A, transforming growth factor-β and α-smooth muscle actin reached preferential peak in the Cut group, when compared with other groups. In addition, Masson staining, Sirius red staining, Victoria blue staining, Gordon-Sweets staining and stress analysis indicated that the ratio of collagen I to III, reticular fibers, failure stress, Young’s modulus and failure length in the SDDS group were similar to those in the normal group, suggesting that healing quality was better in the SDDS group, when compared with the Cut and TDS groups.

Conclusion

Overall, the investigators first administered a comprehensive analysis in the Cut, SDDS and TDS groups through in vivo experiments, which further proved that the obstacle of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice.
LEDet: A Single-Shot Real-Time Object Detector Based on Low-Light Image Enhancement
Authors: Hao Shijie , Wang Zhonghao , Sun Fuming
Published: April 2021

Recently, significant breakthroughs have been achieved in the field of object detection. However, existing methods mostly focus on the generic object detection task. Performance degradation can be unavoidable when applying the existing methods to some specific situations directly, e.g. a low-light environment. To address this issue, we propose a single-shot real-time object Detector based on Low-light image Enhancement, namely LEDet. LEDet adapts itself to the low-light detection task in three aspects. First, a low-light enhancement module is introduced as the image preprocessor, producing the augmented inputs from the low-light images. Second, two modules, i.e. low-light and enhanced features fusion module and the scale-aware channel attention dilated convolution module are designed. These two modules aim at learning robust and discriminative features from objects of various sizes hidden in the darkness. In experiments, we validate the effectiveness of each part of our LEDet model via several ablation studies. We also compare LEDet with various methods on the Exclusively Dark dataset, showing that our model achieves the state-of-the-art performance on the balance between speed and accuracy.
Aortic valve surgery in the UK, trends in activity and outcomes from a 15-year complete national series
Authors: Baghai Max , Wendler Olaf , Grant Stuart W , Goodwin Andrew T , Trivedi Uday , Kendall Simon , Jenkins David P
Published: April 2021

OBJECTIVES

Since the turn of the century, cardiac surgery has evolved quite notably. This study sought to investigate the trends in aortic valve surgery activity and subsequent outcomes in the UK by using a mandatory national cardiac surgical clinical database within the context of a comprehensive public healthcare system (National Health Service).

METHODS

The UK National Adult Cardiac Surgery Audit database provided data for aortic valve surgery procedures performed between 2002 and 2016, and the data were validated and cleaned using reproducible algorithms. The findings and trends in in activity and outcomes were then analysed by financial year.

RESULTS

During the study period, a total of 148 862 procedures were performed, with the number of cases per year peaking in 2014/2015 at 12 483. The mean in-hospital mortality rate for all aortic valve surgery has fallen from 5.6% to 3.4%, despite an increase in patient age and mean logistic EuroSCORE. While the number of isolated aortic valve replacements has remained stable at around 5000 per year, aortic valve replacement and coronary artery bypass graft have increased to over 3200 with transcatheter aortic valve implantation activity continuing to increase.

CONCLUSIONS

This study demonstrates that despite an increase in patient risk profile, there has been a consistent reduction in in-hospital mortality within all aortic valve surgery procedures performed in the UK over a 15-year period. Increasing catheter-based interventions have not yet resulted in a significant decrease in surgical aortic valve replacements in the UK.
Systematic engineering of Saccharomyces cerevisiae for D-lactic acid production with near theoretical yield
Authors: Watcharawipas Akaraphol , Sae-tang Kittapong , Sansatchanon Kitisak , Sudying Pipat , Boonchoo Kriengsak , Tanapongpipat Sutipa , Kocharin Kanokarn , Runguphan Weerawat
Published: April 2021

D-lactic acid is a chiral three-carbon organic acid that can improve the thermostability of polylactic acid. Here, we systematically engineered Saccharomyces cerevisiae to produce D-lactic acid from glucose, a renewable carbon source, at near theoretical yield. Specifically, we screened D-lactate dehydrogenase (DLDH) variants from lactic acid bacteria in three different genera and identified the Leuconostoc pseudomesenteroides variant (LpDLDH) as having the highest activity in yeast. We then screened single-gene deletions to minimize the production of the side products ethanol and glycerol as well as prevent the conversion of D-lactic acid back to pyruvate. Based on the results of the DLDH screening and the single-gene deletions, we created a strain called ASc-d789M which overexpresses LpDLDH and contains deletions in glycerol pathway genes GPD1 and GPD2 and lactate dehydrogenase gene DLD1, as well as downregulation of ethanol pathway gene ADH1 using the L-methionine repressible promoter to minimize impact on growth. ASc-d789M produces D-lactic acid at a titer of 17.09 g/L in shake-flasks (yield of 0.89 g/g glucose consumed or 89% of the theoretical yield). Fed-batch fermentation resulted in D-lactic acid titer of 40.03 g/L (yield of 0.81 g/g glucose consumed). Altogether, our work represents progress towards efficient microbial production of D-lactic acid.
Conservation of glp-1 Regulation and Function in Nematodes
Authors: Rudel David , Kimble Judith
Published: April 2021

The Caenorhabditis elegans (Ce) glp-1 gene encodes a Notch-like receptor. We have cloned glp-1 from C. briggsae (Cb) and C. remanei (Cr), two Caenorhabditis species that have diverged from C. elegans by roughly 20–40 million years. By sequence analysis, we find that the Cb-GLP-1 and Cr-GLP-1 proteins have retained the same motif architecture as Ce-GLP-1, including number of domains. In addition, two regions (CC-linker and regions flanking the ANK repeats) are as highly conserved as regions previously recognized as essential for signaling (e.g., ANK repeats). Phylogenetic analysis of glp-1 sequences suggests a C. briggsae/C. remanei clade with C. elegans as a sister taxon. Using RNAi to test biological functions, we find that Ce-glp-1, Cb-glp-1, and Cr-glp-1 are all required for proliferation of germline stem cells and for specifying blastomere fates in the embryo. In addition, certain biological roles of Cb-glp-1, e.g., in the vulva, have diverged from those of Ce-glp-1 and Cr-glp-1, suggesting a change in either regulation or function of the Cb-glp-1 gene during evolution. Finally, the regulation of glp-1 mRNA, previously analyzed for Ce-glp-1, is conserved in Cb-glp-1, and we identify conserved 3′ UTR sequences that may serve as regulatory elements.
Genetic Architecture of Mandible Shape in Mice: Effects of Quantitative Trait Loci Analyzed by Geometric Morphometrics
Authors: Klingenberg Christian Peter , Leamy Larry J , Routman Eric J , Cheverud James M
Published: April 2021

This study introduces a new multivariate approach for analyzing the effects of quantitative trait loci (QTL) on shape and demonstrates this method for the mouse mandible. We quantified size and shape with the methods of geometric morphometrics, based on Procrustes superimposition of five morphological landmarks recorded on each mandible. Interval mapping for F2 mice originating from an intercross of the LG/J and SM/J inbred strains revealed 12 QTL for size, 25 QTL for shape, and 5 QTL for left-right asymmetry. Multivariate ordination of QTL effects by principal component analysis identified two recurrent features of shape variation, which involved the positions of the coronoid and angular processes relative to each other and to the rest of the mandible. These patterns are reminiscent of the knockout phenotypes of a number of genes involved in mandible development, although only a few of these are possible candidates for QTL in our study. The variation of shape effects among the QTL showed no evidence of clustering into distinct groups, as would be expected from theories of morphological integration. Further, for most QTL, additive and dominance effects on shape were markedly different, implying overdominance for specific features of shape. We conclude that geometric morphometrics offers a promising new approach to address problems at the interface of evolutionary and developmental genetics.
Haldane's Sieve and Adaptation From the Standing Genetic Variation
Authors: Orr H Allen , Betancourt Andrea J
Published: April 2021

We consider populations that adapt to a sudden environmental change by fixing alleles found at mutation-selection balance. In particular, we calculate probabilities of fixation for previously deleterious alleles, ignoring the input of new mutations. We find that “Haldane's sieve”—the bias against the establishment of recessive beneficial mutations—does not hold under these conditions. Instead probabilities of fixation are generally independent of dominance. We show that this result is robust to patterns of sex expression for both X-linked and autosomal loci. We further show that adaptive evolution is invariably slower at X-linked than autosomal loci when evolution begins from mutation-selection balance. This result differs from that obtained when adaptation uses new mutations, a finding that may have some bearing on recent attempts to distinguish between hitchhiking and background selection by contrasting the molecular population genetics of X-linked vs. autosomal loci. Last, we suggest a test to determine whether adaptation used new mutations or previously deleterious alleles from the standing genetic variation.
Joint Linkage and Linkage Disequilibrium Mapping in Natural Populations
Authors: Wu Rongling , Zeng Zhao-Bang
Published: April 2021

A new strategy for studying the genome structure and organization of natural populations is proposed on the basis of a combined analysis of linkage and linkage disequilibrium using known polymorphic markers. This strategy exploits a random sample drawn from a panmictic natural population and the open-pollinated progeny of the sample. It is established on the principle of gene transmission from the parental to progeny generation during which the linkage between different markers is broken down due to meiotic recombination. The strategy has power to simultaneously capture the information about the linkage of the markers (as measured by recombination fraction) and the degree of their linkage disequilibrium created at a historic time. Simulation studies indicate that the statistical method implemented by the Fisher-scoring algorithm can provide accurate and precise estimates for the allele frequencies, recombination fractions, and linkage disequilibria between different markers. The strategy has great implications for constructing a dense linkage disequilibrium map that can facilitate the identification and positional cloning of the genes underlying both simple and complex traits.
An Incremental Approach to Filling Protection Gaps in Equality Rights for Persons with Disabilities
Authors: Richards Jane
Published: April 2021

The Convention on the Rights of Persons with Disabilities (CRPD) guarantees that persons with disabilities (‘PWD’) are to be equal before and under the law. There are almost identical equality guarantees in the Canadian Charter of Rights and Freedoms and Hong Kong's mini constitution – the Basic Law. Australia boasts similar legislative equality guarantees for PWD. The CRPD Committee has interpreted the right broadly, whereas constitutional courts have taken a proportionality approach, balancing the right to substantive equality against competing concerns. The tension between these methods of rights protection means the CRPD is being positioned as an alternative model of rights protection, but it is not an alternative mechanism for enforcement. This article calls on the Committee to modify its guidance to make suggestions to state parties as to how incremental advances in rights protection can be immediately implemented, even if in the short-term, these advances fall short of full inclusion.
Dynamic hedging in incomplete markets using risk measures
Authors: Gaillardetz Patrice , Hachem Saeb
Published: April 2021

In this paper, we consider the pricing of financial derivatives that involve dynamic hedging strategies and payments within the planning horizon. Equity-indexed annuities (EIAs), guaranteed investment certificates (GICs) and American and barrier options are typical examples of these products. Our exploration involves the use and comparison of alternative models that use risk measures. Although the hedging is done for each observation of the input stochastic process, the appropriate mix of risk measures and state dynamic equations helps the issuer to appropriately tailor the overall risk exercise. These different models are solved by a unified backward stochastic dynamic programming framework that we imbed with parametric techniques to shorten the running time and manage the curse of dimensionality in dynamic programming. To demonstrate the flexibility of this framework we present numerical examples featuring GICs and point-to-point EIAs. Finally, by using sampling techniques, optimal hedging strategies and specific indicators of the hedging performance, we make recommendations on how to fine tune the risk measure parameters.
Development of a Selective Agar for Improving Campylobacter jejuni Detection in Food
Authors: Ha Jimyeong , Seo Yeongeun , Kim Yujin , Choi Yukyung , Oh Hyemin , Lee Yewon , Park Eunyoung , Kang Joohyun , Lee Heeyoung , Lee Soomin , Yoon Yohan
Published: April 2021

Background

Campylobacter jejuni is a major gastroenteritis-causing foodborne pathogen. However, it is difficult to isolate when competing bacteria or cold-damaged cells are present.

Objective

Herein, a medium (Campylobacter selective agar, CSA) was developed and supplemented with catalase, L-serine, L-cysteine, and quercetin for the selective detection of C. jejuni in food.

Method

The C. jejuni-detection efficiency in media broth and chicken tenders was evaluated. The pathogen was enumerated on modified charcoal–cefoperazone–deoxycholate agar (mCCDA), CSA supplemented with 4 µM catalase (CSA-C4), 8 µM catalase (CSA-C8), 20 mM L-serine (CSA-S20) or 50 mM L-serine (CSA-S50), and mCCDA supplemented with 0.5 mM L-cysteine (mCCDA-LC0.5), 1 mM L-cysteine (mCCDA-LC1), 40 µM quercetin (mCCDA-Q40) or 320 µM quercetin (mCCDA-Q320). The detection efficiency was then evaluated by counting colonies on the selective agar media. Quantitative assessment was also performed using chicken and duck carcasses.

Results

The C. jejuni detection efficiencies were higher (P < 0.05) in the groups CSA-C4 or CSA-C8, and CSA-S20 or CSA-S50, than mCCDA, and the detection efficiencies were maintained even in the presence of Acinetobacter baumannii, a competing bacterium. In the quantitative test, CSA-C8 and CSA-S50 demonstrated higher C. jejuni-detection efficiencies than mCCDA (control).

Conclusions

Therefore, CSA-C8 and CSA-S50 improved the detection efficiency of C. jejuni in poultry products by promoting the recovery of cold-damaged cells.

Highlights

When using CSA-C8 or CSA-S50 developed in this study for detection of C. jejuni in food, detection efficiency was higher than mCCDA.