bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the cBN Electroplated End-Mill for High Precision Machining of CFRP
Authors: Yamashita Shinnosuke , Furuki Tatsuya , Kousaka Hiroyuki , Hirogaki Toshiki , Aoyama Eiichi , Inaba Kiyofumi , Fujiwara Kazuna
Published: January 2021

Recently, the demand of carbon fiber reinforced plastics (CFRP) has been rapidly increased in various fields. In most cases, CFRP products requires a finish machining like cutting or grinding. In the case of an end-milling, burrs and uncut fibers are easy to occur. On the other hand, a precise machined surface and edge will be able to obtain by using the grinding tool. Therefore, this research has been developed a novel the cBN electroplated end-mill that combined end-mill and grinding tool. In this report, the effectiveness of developed tool was investigated. First, the developed tool cut the CFRP with side milling. As the result, the cBN abrasives that were fixed on the outer surface of developed tool did not drop out. Next, the end-milled surface of CFRP was ground with the developed tool under several grinding conditions based on the Design of Experiment. Consequently, the optimum grinding condition that can obtain the sharp edge which does not have burrs and uncut fibers was found. However, surface roughness was not good enough. Thus, an oscillating grinding was applied. In addition, the theoretical surface roughness formula in case using the developed tool was formularized. As the result, the required surface roughness in the airplane field was obtained.
Study on Forming Behaviour of Friction Stir Welded Blanks During Single Point Incremental Forming (SPIF) Process
Authors: Marathe Shalin , Raval Harit
Published: January 2021

The automobile, transportation and shipbuilding industries are aiming at fuel efficient products. In order to enhance the fuel efficiency, the overall weight of the product should be brought down. This requirement has increased the use of material like aluminium and its alloys. But, it is difficult to weld aluminium using conventional welding processes. This problem can be solved by inventions like friction stir welding (FSW) process. During fabrication of product, FSW joints are subjected to many different processes and forming is one of them. During conventional forming, the formability of the welded blanks is found to be lower than the formability of the parent blank involved in it. One of the major reasons for reduction in formability is the global deformation provided on the blank during forming process. In order to improve the formability of homogeneous blanks, Single Point Incremental Forming (SPIF) is found to be giving excellent results. So, in this work formability of the welded blanks is investigated during the SPIF process. Friction Stir Welding is used to fabricate the welded blanks using AA 6061 T6 as base material. Welded blanks are formed in to truncated cone through SPIF process. CNC milling machine is used as SPIF machine tool to perform the experimental work. In order to avoid direct contact between weld seam and forming tool, a dummy sheet was used between them. As responses forming limit curve (FLC), surface roughness, and thinning are investigated. It was found that use of dummy sheet leads to improve the surface finish of the formed blank. The formability of the blank was found less in comparison to the parent metal involved in it. Uneven distribution of mechanical properties in the welded blanks leads to decrease the formability of the welded blanks.
A Hybrid Physical Model Based Artificial Neural Network Approach to Predict Surface Texture in the Honing of Engine Cylinder Bore
Authors: Afzel Burhan , Zhang Xueping , Srivastava Anil K.
Published: January 2021

This study proposes a hybrid model that utilizes a physical model and Artificial Neural Networks (ANN) approach to predict surface roughness during cylinder bore honing with an improved prediction efficiency of 90% compared to the standalone physical model. As a critical component of internal combustion engine technology, improvement in the surface roughness of cylinder bore can significantly reduce friction, wear and oil consumption, resulting in improved engine performance. Desired surface roughness in cylinder bore is imparted by honing, which serves as the terminal process in cylinder bore manufacturing. The cylinder bore honing process consists of rough honing, fine honing, and plateau honing stage. Each stage further involves variables such as honing stone geometry, grain size, grain concentration, honing speed, pressure, feed, over travel, number of strokes, etc. In literature, different approaches have been proposed to determine the influence of process parameters on the surface roughness of the honed cylinder bore. However, these approaches have their limitations. Experimental based studies are limited by the number of parameters that can be considered, analytical analysis methods involve extensive calculations resulting in reduced computational efficiency and accuracy, while machine learning approaches require a large amount of data. To overcome these limitations, this study employs a hybrid model to investigate the evolution of roughness at the rough and fine stage of the honing process. A two-phase approach is employed; first, a physical model is used to determine the surface roughness using various parameters. Secondly, these results are applied to train the ANN that can predict surface roughness for new parameters with a difference of less than 10% from the physical model.
Expulsion Intensity Monitoring and Modeling in Resistance Spot Welding Based on Electrode Displacement Signals
Authors: Xia Yu-Jun , Shen Yan , Zhou Lang , Li Yong-Bing
Published: January 2021

Weld expulsion is one of the most common welding defects during resistance spot welding (RSW) process especially for high strength steels (HSS). In order to control and eventually eliminate weld expulsion in production, accurate assessment of the expulsion severity should be the first step and is urgently required. Among the existing methods, real-time monitoring of RSW-related process signals has become a promising approach to actualize the online evaluation of weld expulsion. However, the inherent correlation between the process signals and the expulsion intensity is still unclear. In this work, a commonly used process signal, namely the electrode displacement and its instantaneous behavior when expulsion occurs are systematically studied. Based upon experiments with various electrodes and workpieces, a nonlinear relation between the weight of expelled metal and the sudden displacement drop accompanied by the occurrence of weld expulsion is observed, which is mainly influenced by electrode tip geometry but not by material strength or sheet thickness. The intrinsic relationship between this specific signal feature and the magnitude of expulsion is further explored through geometrical analysis, and a modified analytical model for online expulsion evaluation is finally proposed. It is shown that the improved model could be applied to domed electrodes with different tip geometries and varying workpieces ranging from low carbon steel to HSS. The error of expulsion estimation could be limited within ±20.4 mg (±2σ) at a 95% confidence level. This study may contribute to the online control of weld expulsion to the minimum level.
On Transfer Learning of Traditional Frequency and Time Domain Features in Turning
Authors: Yesilli Melih C. , Khasawneh Firas A.
Published: January 2021

There has been an increasing interest in leveraging machine learning tools for chatter prediction and diagnosis in discrete manufacturing processes. Some of the most common features for studying chatter include traditional signal processing tools such as Fast Fourier Transform (FFT), Power Spectral Density (PSD), and the Auto-correlation Function (ACF). In this study, we use these tools in a supervised learning setting to identify chatter in accelerometer signals obtained from a turning experiment. The experiment is performed using four different tool overhang lengths with varying cutting speed and the depth of cut. We then examine the resulting signals and tag them as either chatter or chatter-free. The tagged signals are then used to train a classifier. The classification methods include the most common algorithms: Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), and Gradient Boost (GB). Our results show that features extracted from the Fourier spectrum are the most informative when training a classifier and testing on data from the same cutting configuration yielding accuracy as high as %96. However, the accuracy drops significantly when training and testing on two different configurations with different structural eigenfrequencies. Thus, we conclude that while these traditional features can be highly tuned to a certain process, their transfer learning ability is limited. We also compare our results against two other methods with rising popularity in the literature: Wavelet Packet Transform (WPT) and Ensemble Empirical Mode Decomposition (EEMD). The latter two methods, especially EEMD, show better transfer learning capabilities for our dataset.
Data-Enabled Modeling and Performance Evaluation of Multistage Serial Manufacturing Systems With Quality Rework
Authors: Zhu Cheng , Yu Tian , Chang Qing , Arinez Jorge
Published: January 2021

In a multistage serial production line, products with defect can be repaired or reworked to ensure high product quality. This paper studies a multistage serial manufacturing system with quality rework loops. Rework is the activity to repair or repeat the work on the defect parts during manufacturing processes, and it adds to cost and cycle time. This paper introduces an event-based data-enabled mathematical model for a stochastic production line with quality rework loops. The system performance properties are analyzed and permanent production loss due to quality rework loops is identified. The mathematical model and system performance identification methodology are studied analytically through numerical case studies.
Transient Melt Pool Formation in Laser-Powder Bed Fusion Process
Authors: Rauniyar Santosh , Chou Kevin
Published: January 2021

Parts are built in a layer-by-layer fashion in the laser powder bed fusion process. Each layer of scan in the parts is defined by a scan strategy that consists of many small patches and scans. The scan length of those multiple scans is not always long enough to have reached a quasi-steady state of the melt pool. The length at which it achieves a steady state is different for different process parameters. The available literature related to the melt pool considers the melt pool has already achieved a steady state, which holds true to a large extent. However, there is always a transient state of melt pool with different characteristics compared to the quasi-steady state. The transient state of the melt pool is particularly significant for small features and thin walls. This paper explores the cross-section and width of the melt track in the transient state. Single-tracks are deposited on semi-cylindrical samples with Ti-6Al-4V powder particles for three levels of power and speed combinations. The single tracks are built at a certain height from the base plate instead of on the build plate to include the effect of the powder particles. The experiment includes single tracks of four scan lengths i.e. 0.25, 0.5, 1 and 2 mm. Once the parts are built and removed from the build plate, White light interferometer is used to capture the melt track information and data processing is done in Matlab™. The results show that the transient length is directly proportional to the laser power and inversely proportional to the scan speed. The highest transient length value is obtained for the highest power of 195 W and lowest scan speed of 50 mm/s.
Fault Diagnosis of Timed Event Systems: An Exploration of Machine Learning Methods
Authors: Cohen Joseph , Jiang Baoyang , Ni Jun
Published: January 2021

Especially common in discrete manufacturing, timed event systems often require a high degree of synchronization for healthy operation. Discrete event system methods have been used as mathematical tools to detect known faults, but do not scale well for problems with extensive variability in the normal class. A hybridized discrete event and data-driven method is suggested to supplement fault diagnosis in the case where failure patterns are not known in advance. A unique fault diagnosis framework consisting of signal data from programmable logic controllers, a Timed Petri Net of the normal process behavior, and machine learning algorithms is presented to improve fault diagnosis of timed event systems. Various supervised and unsupervised machine learning algorithms are explored as the methodology is implemented to a case study in semiconductor manufacturing. State-of-the-art classifiers such as artificial neural networks, support vector machines, and random forests are implemented and compared for handling multi-fault diagnosis using programmable logic controller signal data. For unsupervised learning, classifiers based on principal component analysis utilizing major and minor principal components are compared for anomaly detection. The rule-based extreme random forest classifier achieves the highest validation accuracy of 98% for multi-fault classification. Likewise, the unsupervised learning approach shows similar success, yielding anomaly detection rates of 98% with false alarms under 3%. The industrial feasibility of this method is notable, with the results achieved with a training set 99% smaller than the supervised learning classifiers.
A Machine Learning Approach to Model the Electrospinning Process of Biocompatible Materials
Authors: Toscano Juan Diego , Li Zebin , Segura Luis Javier , Sun Hongyue
Published: January 2021

Electrospinning is a manufacturing technique that can produce microfibers and nanofibers from polymeric solutions. It has a broad range of applications in areas such as tissue engineering, flexible electronics, filtering, etc. However, due to its chaotic behavior, the fibers obtained by this process are prone to high diameter variations. The high diameter variations will cause poor final product functionality. The diameter is affected by process variables, ambient conditions and in-situ measurements. It is therefore important to model their effect on the fiber diameter variation, which is rarely investigated in the literature. Towards this end, this paper systematically studies the electrospinning process of a biocompatible polymer (i.e., polyacrylonitrile (PAN) 10%) via experimental study and data-driven modeling. In particular, three critical process variables (i.e., voltage, tip-to-collector distance, and polymer flow rate), are varied in a central composite design of experiment. Twenty-four runs are executed for the data collection, during which the in-situ measurements are collected via a customized sensing system. After each experiment, scanning electron microscope (SEM) images are taken from the nonwoven mats and characterized to capture the diameter and the diameter variations. Three machine learning methods, Lasso, random forest (RF), and support vector machine (SVM), are applied to the collected data. The model performance is evaluated in the real case study on the electrospinning of polymeric solution. The most predictive model (RF) can yield an around 15% relative error for prediction in testing data on average over 100 replications.
Investigation of Circuit Parameters in Tube Electrode High-Speed Electrochemical Discharge Machining
Authors: Zhang Yan , Rashedul Islam Md. , Ji Lei , Jiang Baoyang
Published: January 2021

Tube electrode high-speed electrochemical discharge machining (TSECDM) has been effectively used in the manufactures of micro holes with difficult-to-cut conductive materials in the field of aerospace industry. The design and parameters of circuit are critical for the machining performances of TSECDM. In this paper, the influences of circuit on the TSECDM performances are studied. Firstly, a relaxation type RLC generator is designed and analyzed by MATLAB simulation. Secondly, the effects of RLC circuit parameters such a resistor (R), capacitor (C) and inductor (L) on machining performances are investigated by experiments on the bulk of SS304 alloys by limiting factors changing. Finally, the analysis achievement indicated that the circuit selection parameters value R (15Ω); C (220nF); L (0.13mH) can be used to obtain a better machining performance.
Surrogate Pore Generations in L-PBF Ti64 and Effects on Mechanical Behavior
Authors: Zhang Shanshan , Chertmanova Sabina , Chou Kevin
Published: January 2021

In this study, surrogate pores were designed and generated at specific locations inside tensile specimens fabricated by laser powder bed fusion (L-PBF) processing and further evaluated in porosity characteristics and mechanical properties. The objectives are to demonstrate the feasibility of pore generation and to characterize the pores and examine the effect from various process conditions. The pore-generated specimens were fabricated in an L-PBF system using Ti-6Al-4V (Ti64) powder. Overall, specimens were made using default settings. But, during processing the middle section of the tensile specimens, single track exposures were applied to induce keyhole pores with different energy density levels as well as different scan track numbers and layers. An X-ray computed tomography system was utilized to measure and analyze surrogate pores in the fabricated specimens in pore counts, volumes and sphericity related to process conditions. The results showed that, as expected, pore formation increases with the laser energy density applied and the number of tracks and layers exposed, although individual tracks exhibit a high variability. Specimens evaluated by tensile testing and fractography show that surrogate pores produced in this study so far influence only the ductility of the specimens noticeably, but not Young’s modulus, nor the yield and tensile strengths.
Vision-Based Precision Deburring and Edge Breaking Process Quality Control
Authors: Gupta Kartik , Grimm Cindy , Sencer Burak , Balasubramanian Ravi
Published: January 2021

This paper presents a computer vision system for evaluating the quality of deburring and edge breaking on aluminum and steel blocks. This technique produces both quantitative (size) and qualitative (quality) measures of chamfering operation from images taken with an off-the-shelf camera. We demonstrate that the proposed computer vision system can detect edge chamfering geometry within a 1–2mm range. The proposed technique does not require precise calibration of the camera to the part nor specialized hardware beyond a macro lens. Off-the-shelf components and a CAD model of the original part geometry are used for calibration. We also demonstrate the effectiveness of the proposed technique on edge breaking quality control.
Experimental Study on Cost-Effective Additive Manufacturing of Silica Aerogel
Authors: Guo Zipeng , Yang Ruizhe , Wang Tianjiao , An Lu , Ren Shenqiang , Zhou Chi
Published: January 2021

The conventional manufacturing process of aerogel insulation material relies largely on the supercritical drying, which suffers from issues of massive energy consumption, high-cost equipment and prolonged processing time. With the consideration of large market demand of the aerogel insulation material in the next decade, a low-cost and scalable fabrication technique is highly desired. In this paper, a direct ink writing (DIW) method is used to three-dimensionally fabricate the silica aerogel insulation material, followed by room-temperature and ambient pressure drying. Compared to the supercritical drying and freeze-drying, the reported method significantly reduces the fabrication time and costs. The cost-effective DIW technique offers the capability to print complex hollow internal structures, coupled with the porous structure, is found to be beneficial to the thermal insulation property. The addition of fiber to the ink assures the durability of the fabricated product. The foam ink preparation methods and the printability are demonstrated in this paper, along with the printed samples for characterizing thermal insulation performance and mechanical properties.
A field study on the relationship between tick burden and deltamethrin resistance in Rhipicephalus microplus isolates of Indian household cattle

Authors: Palavesam Azhahianambi , Ramakrishnan Ram Narendran , Harikrishnan Tirunelveli Jayagopal , Sagar Sharath V , Rajeswaran Abiraami , Raj Gopal Dhinakar , Latha Bhaskaran Ravi
Published: January 2021

A total of 2809 ixodid ticks were collected by screening 4560 household cattle from six different agro-climatic zones of Tamil Nadu, a southern state of India. Among the ixodid ticks, Rhipicephalus microplus tick isolates were subjected to Adult Immersion Test (AIT) and Larval Packet Test (LPT) using deltamethrin. The mean % of ixodid tick infested cattle population was 63.2%±10.9. Positive correlation was found between the tick burden on household cattle and Resistance Factor (R=0.66). Further, 44% variance in the tick burden on cattle is explained by LPT based resistance factor suggesting deltamethrin resistance level is one of the contributing factors to the tick load on cattle. Analysis of DNA sequence of sodium channel gene domain II-S4-5 linker region of all deltamethrin resistant R. microplus tick isolates, confirmed the absence of point mutation at the 190th nucleotide which suggests the possible mutation in other regions of sodium channel gene of R. microplus tick isolates of south India and/or alternate resistance mechanisms.
Analysis of ErAs nanoparticle surface grown using a two-step modified diffusion length process
Authors: Zhang Yuanchang , Eyink Kurt G. , Hill Madelyn , Urwin Brittany , Mahalingam Krishnamurthy
Published: January 2021

Erbium arsenide nanoparticles (ErAs NPs) grown using a two-step modified diffusion length growth process are studied. The process consists of a low diffusion length (LDL) deposition step for nucleation followed by a high diffusion length (HDL) deposition step for the growth of existing nuclei without forming new nuclei. With the LDL and HDL growth conditions properly coordinated, independent control over the NP size is demonstrated over a wide range of NP densities (14–309 NP/μm2). This control is attributed to the change of Péclet number between the LDL and HDL steps, which enables complete capture of the adatoms by the existing nuclei. The appropriate LDL and HDL growth conditions are identified for practical applications of the process. Given the uniqueness of the process, the ErAs nucleus critical size (∼7 Er atoms) is derived in the nucleation regime in the LDL step exhibiting consistency with the previous observation for ErAs NP growth.
Acoustic characteristics of synthesized signals of Chinese bahaba (Bahaba taipingensis)
Authors: Wei Chong , Huang Jiali , Dai Ming , Zhang Siyu , Huang Honghui , Zhang Yu
Published: January 2021

As a member of Sciaenidae, Chinese bahaba (Bahaba taipingensis) generate sounds using sonic muscles to drive the swim bladder. In this study, the drumming sounds of Chinese bahaba in two groups differing in body size were recorded in an indoor aquarium and an outdoor pond. A piecewise exponential oscillation function was developed to synthesize the signals with a good agreement. Statistical comparisons found that the oscillation frequency and damping coefficient (part 1) of synthesized signals from larger-sized fish were lower. The results suggest that the acoustic characteristics of Chinese bahaba signals are related to fish morphology as the physiological age alters.
Small-Groups Versus Full-Class Exergaming on Urban Minority Adolescents’ Physical Activity, Enjoyment, and Self-Efficacy
Authors: McDonough Daniel J. , Liu Wenxi , Su Xiwen , Gao Zan
Published: January 2021

Background: The effects of school-based exergaming interventions on adolescents’ physical activity (PA) and psychosocial outcomes have been mixed. Researchers speculate this may be attributed to design issues. Therefore, this study examined differences in urban minority adolescents’ PA, enjoyment, and self-efficacy during small-groups and full-class exergaming.Methods: Forty-seven urban minority adolescents (83% black;) completed two 15-minute exergaming sessions on the Xbox One Kinect Just Dance: (1) small groups (n = 3–4) and (2) full class (n = 23–24). Participants’ time in sedentary behavior, light PA, and moderate to vigorous PA and steps were retrieved from ActiGraph GT3X+ accelerometers with enjoyment and self-efficacy assessed using validated surveys.Results: Participants spent significantly more time in sedentary behavior (5.9 [5.2] min vs 3.5 [2.7] min, respectively:P < .001,d = 0.57) and less time in moderate-to-vigorous PA (2.1 [2.8] min vs 5.5 [2.2] min, respectively:P < .001,d = 0.85) during the full-class versus the small-groups session. Moreover, small-groups exergaming resulted in significantly higher steps than the full-class exergaming (504.2 [132.1] vs 387.8 [122.1], respectively:P = .01,d = 0.50) and significantly greater enjoyment (3.5 [1.1] vs 3.2 [1.0], respectively:P = .02,d = 0.37). There were no significant differences between sessions for time in light PA and self-efficacy.Conclusions: Small-groups exergaming appears ideal for promoting enjoyable PA at higher intensities and lower sedentary time in underserved minority adolescents.
Ancient protein analysis in archaeology
Authors: Hendy Jessica
Published: January 2021

This review synthesizes some of the major advances and applications of ancient protein analysis in the field of archaeology.
The translocon-associated protein (TRAP) complex regulates quality control of N-linked glycosylation during ER stress
Authors: Phoomak Chatchai , Cui Wei , Hayman Thomas J. , Yu Seok-Ho , Zhao Peng , Wells Lance , Steet Richard , Contessa Joseph N.
Published: January 2021

A new method for detecting N-glycosylation reveals a role for the TRAP complex and a mechanism for cell state–specific regulation.
Integrated quantitative PIXE analysis and EDX spectroscopy using a laser-driven particle source
Authors: Mirani F. , Maffini A. , Casamichiela F. , Pazzaglia A. , Formenti A. , Dellasega D. , Russo V. , Vavassori D. , Bortot D. , Huault M. , Zeraouli G. , Ospina V. , Malko S. , Apiñaniz J. I. , Pérez-Hernández J. A. , De Luis D. , Gatti G. , Volpe L. , Pola A. , Passoni M.
Published: January 2021

A laser-driven particle source is exploited for the elemental and stratigraphic characterization of a nonhomogeneous sample.
Leaf-derived ABA regulates rice seed development via a transporter-mediated and temperature-sensitive mechanism
Authors: Qin Peng , Zhang Guohua , Hu Binhua , Wu Jie , Chen Weilan , Ren Zhijie , Liu Yulan , Xie Jing , Yuan Hua , Tu Bin , Ma Bingtian , Wang Yuping , Ye Limin , Li Legong , Xiang Chengbin , Li Shigui
Published: January 2021

A leaf-to-caryopsis abscisic acid transport mechanism ensures normal seed development in response to variable temperatures.
In situ measurements of intracellular thermal conductivity using heater-thermometer hybrid diamond nanosensors
Authors: Sotoma Shingo , Zhong Chongxia , Kah James Chen Yong , Yamashita Hayato , Plakhotnik Taras , Harada Yoshie , Suzuki Madoka
Published: January 2021

Newly made hybrid nanosensors measured thermal conductivity in cells to be about one-sixth of that in water.
Genetic analysis of amyotrophic lateral sclerosis identifies contributing pathways and cell types
Authors: Saez-Atienzar Sara , Bandres-Ciga Sara , Langston Rebekah G. , Kim Jonggeol J. , Choi Shing Wan , Reynolds Regina H. ,   the International ALS Genomics Consortium,   ITALSGEN, Abramzon Yevgeniya , Dewan Ramita , Ahmed Sarah , Landers John E. , Chia Ruth , Ryten Mina , Cookson Mark R. , Nalls Michael A. , Chiò Adriano , Traynor Bryan J.
Published: January 2021

Massive genetic analysis identifies critical pathways and cell types involved in pathogenesis of amyotrophic lateral sclerosis.
PD-1 blockade exacerbates
Mycobacterium tuberculosis
infection in rhesus macaques
Authors: Kauffman Keith D. , Sakai Shunsuke , Lora Nickiana E. , Namasivayam Sivaranjani , Baker Paul J. , Kamenyeva Olena , Foreman Taylor W. , Nelson Christine E. , Oliveira-de-Souza Deivide , Vinhaes Caian L. , Yaniv Ziv , Lindestam Arleham Cecilia S. , Sette Alessandro , Freeman Gordon J. , Moore Rashida ,   NIAID/DIR Tuberculosis Imaging Program, Sher Alan , Mayer-Barber Katrin D. , Andrade Bruno B. , Kabat Juraj , Via Laura E. , Barber Daniel L.
Published: January 2021

Blockade of the PD-1 coinhibitory pathway compromises immune control of
Mycobacterium tuberculosis
infection in rhesus macaques.
The Reliability of Metagenome-Assembled Genomes (MAGs) in Representing Natural Populations: Insights from Comparing MAGs against Isolate Genomes Derived from the Same Fecal Sample
Authors: Meziti Alexandra , Rodriguez-R Luis M. , Hatt Janet K. , Peña-Gonzalez Angela , Levy Karen , Konstantinidis Konstantinos T.
Published: January 2021

Metagenome assembly and the recovery of metagenome-assembled genomes (MAGs) have recently become common tasks for microbiome studies across environmental and clinical settings. However, the extent to which MAGs can capture the genes of the population they represent remains speculative.
The convexity of carbonate hilltops: 36Cl constraints on denudation and chemical weathering rates and implications for hillslope curvature
Authors: Ben-Asher Matan , Haviv Itai , Crouvi Onn , Roering Joshua J. , Matmon Ari
Published: January 2021

Carbonate hillslopes are often soil mantled and display a classic convex morphology. In this study we examine controls on carbonate hillslope denudation and morphology using a modified regolith mass balance equation to account for chemical weathering and dust input—two fluxes that are commonly neglected in settings with silicate-dominated bedrock. We utilize seven study sites in the Eastern Mediterranean across a significant gradient in the mean annual rainfall and dust deposition flux. Combining cosmogenic 36Cl-derived hilltop denudation rates with an estimate of the regolith chemical depletion and the quantified fraction of dust in the regolith we predict hilltop curvature and compare our predictions with observations based on high-resolution airborne LiDAR (light detection and ranging).

Denudation rates vary from 5 to 210 mm/k.y. and increase with mean annual rainfall. Less resistant carbonates (chalk) experience faster denudation rates relative to more resistant dolo-limestone and are less prone to chemical weathering. Soil production exhibits a humped dependency on soil thickness.

The observed hilltop curvature varies as a function of rainfall and dust flux with a minimum at sub-humid sites. While trends in hilltop convexity are often solely attributed to variations in erosion rate, our results illustrate the additional effects of dust production and chemical depletion. Our mass balance model implies that drier sites in the south probably experienced a more intricate history of regolith production due to dust flux fluctuations. Thus, by incorporating dust flux and chemical weathering to the classic hillslope evolution model we are able to identify a complex relation between hilltop curvature, soil production, and climate.
Supplemental Material: Discovery of a large subsoil nitrate reservoir in an arroyo floodplain and associated aquifer contamination
Authors: Linhoff Benjamin , Lunzer John
Published: January 2021

Additional information on site background, sampling methods, chloride mass balance calculations, and vadose zone modeling.
Supplemental Material: Gulf of Aden spreading does not conform to triple-junction formation
Authors: Almalki Khalid , Betts Peter
Published: January 2021

Additional geological and geophysical background information and descriptions of the data and methodology.
Fifteen-minute consultation: The review of a child with trisomy 21 (Down’s syndrome)
Authors: Dalrymple Rebecca Amy , Somerville Laura Helen , Hamza Sherin , Matta Nashwa
Published: January 2021

Down’s syndrome (DS) is the most common chromosomal abnormality seen in live born children and it is the most common genetic cause of intellectual disability. It is associated with abnormalities in many body systems, some of which can cause life threatening complications. This article aims to cover the important aspects to cover when seeing children with DS for their routine follow-up in the neurodevelopmental or general paediatric clinic.
Saw transection of retained compression screws with damaged heads instead of removal in revision first metatarsal osteotomy: a technique tip
Authors: Faroug Radwane , Abbasian Ali
Published: January 2021

Distal first metatarsal osteotomy is performed to correct hallux valgus. The surgery is being performed throughout the UK in increasing numbers. The osteotomies used are commonly fixed with one or two variable pitch compression screws. Recurrence of the deformity or inadequate correction in the primary surgery may require revision osteotomy which necessitates removal of previous screws. Revision rates for scarf osteotomy have been reported at 5%. Removal of screws can be challenging as they are often buried in bone and/or the screw heads can get damaged even despite meticulous preparation. Various techniques for removal of damaged screws are described, which require additional equipment and may result in significant loss of the host bone. We describe another technique where a standard Stryker TPS sagittal saw and saw blade (Kalamazoo, USA) are used to cut through the shaft of the compression screws in line with the planned revision osteotomy. We have successfully performed this on two occasions with good results, and describe our experience of using this technique which eliminates the need for complex over drilling procedures often required for removing stripped and retained screws
Postnatal IVIG treatment for persistent anaemia in neonate due to congenital parvovirus infection
Authors: Janssen Olivia , Lin Jing
Published: January 2021

Congenital parvovirus B19 infection is a rare but serious condition that can result in hydrops fetalis and fetal death. Due to the virus’ cytotoxic effect on fetal red blood cell precursors, postnatal infection can cause a neonatal viremia and secondary pure red cell aplasia. Here, we describe a case of congenital parvovirus infection in a preterm infant complicated by hydrops fetalis and chronic anaemia that responded to postnatal treatment with intravenous immunoglobulin administered on day of life 44. After treatment, the anaemia resolved as the neonate exhibited interval increases in haemoglobin, haematocrit and reticulocyte count with no subsequent need for red blood cell transfusions.
Management of refractory pain in Stiff-Person syndrome
Authors: Cirnigliaro Frank Arthur , Gauthier Nicole , Rush Moira
Published: January 2021

Stiff-Person syndrome (SPS) is a rare autoimmune neurological disorder characterised by episodic painful muscle rigidity and violent spasms. A significant trigger for the painful spasms experienced by patients is pain itself, making optimal pain management and avoidance a necessity. While first-line and second-line therapies for spasm prevention and termination are known, there is a paucity of evidence to guide pain management. We report the case of a 26-year-old woman with SPS referred for excruciating muscle cramping and rigidity with pain lasting beyond the episodes themselves. We report the novel use of ketamine and intravenous magnesium sulfate which may provide analgesia, spasm avoidance and early termination of exacerbations in SPS.
Evaluation of an OPEN Stewardship generated feedback intervention to improve antibiotic prescribing among primary care veterinarians in Ontario, Canada and Israel: protocol for evaluating usability and an interrupted time-series analysis
Authors: Acharya Kamal Raj , Brankston Gabrielle , Soucy Jean-Paul R , Cohen Adar , Hulth Anette , Löfmark Sonja , Davidovitch Nadav , Ellen Moriah , Fisman David N , Moran-Gilad Jacob , Steinman Amir , MacFadden Derek R , Greer Amy L
Published: January 2021

Introduction

Antimicrobial resistance (AMR) impacts the health and well-being of animals, affects animal owners both socially and economically, and contributes to AMR at the human and environmental interface. The overuse and/or inappropriate use of antibiotics in animals has been identified as one of the most important drivers of the development of AMR in animals. Effective antibiotic stewardship interventions such as feedback can be adopted in veterinary practices to improve antibiotic prescribing. However, the provision of dedicated financial and technical resources to implement such systems are challenging. The newly developed web-based Online Platform for Expanding Antibiotic Stewardship (OPEN Stewardship) platform aims to automate the generation of feedback reports and facilitate wider adoption of antibiotic stewardship. This paper describes a protocol to evaluate the usability and usefulness of a feedback intervention among veterinarians and assess its impact on individual antibiotic prescribing.

Methods and analysis

Approximately 80 veterinarians from Ontario, Canada and 60 veterinarians from Israel will be voluntarily enrolled in a controlled interrupted time-series study and their monthly antibiotic prescribing data accessed. The study intervention consists of targeted feedback reports generated using the OPEN Stewardship platform. After a 3-month preintervention period, a cohort of veterinarians (treatment cohort, n=120) will receive three feedback reports over the course of 6 months while the remainder of the veterinarians (n=20) will be the control cohort. A survey will be administered among the treatment cohort after each feedback cycle to assess the usability and usefulness of various elements of the feedback report. A multilevel negative-binomial regression analysis of the preintervention and postintervention antibiotic prescribing of the treatment cohort will be performed to evaluate the impact of the intervention.

Ethics and dissemination

Research ethics board approval was obtained at each participating site prior to the recruitment of the veterinarians. The study findings will be disseminated through open-access scientific publications, stakeholder networks and national/international meetings.
Incidence of HIV and HCV in people who inject drugs: a systematic and meta-analysis review protocol
Authors: Sharhani Asaad , Jorjoran Shushtari Zahra , Rahmani Azam , Armoon Bahram , Noroozi Mehdi , Ahounbar Elaheh , Karimi Salah Eddin , Higgs Peter
Published: January 2021

Introduction

HIV and hepatitis C virus (HCV) are major health concerns globally. This systematic review and meta-analysis protocol study aims to estimate the incidence of HIV and HCV among people who inject drugs (PWIDs) by reviewing studies that have applied mathematical modelling. The primary purpose of this systematic review is to identify and review mathematical modelling studies of HIV and HCV incidence in PWIDs.

Methods and analysis cohort, cross-sectional and clinical trial studies conducted to estimate the incidence of HIV and HCV based on mathematical models or have evaluated the effectiveness of mathematical models will be considered for inclusion in the review. A comprehensive search applying a Cochrane approach will be used to identify relevant primary studies, published between January 2000 and July 2020, and indexed in PubMed, EMBASE, Opengrey, WOS, SCOPUS and Cochrane Library with no restriction on language. This protocol was prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Study selection and data extraction will be performed by two independent reviewers. Assessment of risk of bias will be implemented using forms of the Critical Appraisal Skills Programme. Publication bias will be assessed by funnel plots, Begg’s and Egger’s tests. A meta-analysis will be conducted to answer the first research question, ‘What is the incidence of HIV and HCV when applying mathematical model in PWID?’. Clinical heterogeneity will be assessed by looking at the characteristics of participants, method of diagnosis and case definitions in the included primary studies. In addition, subgroup analyses will be conducted for population and secondary outcomes.

Ethics and dissemination

There are no ethical issues related to this study. The findings will be published in peer-reviewed scientific journals and presented at international and national conferences.

PROSPERO registration number

CRD42019126476.
Instantaneous wave-free ratio guided multivessel revascularisation during percutaneous coronary intervention for acute myocardial infarction: study protocol of the randomised controlled iMODERN trial
Authors: Beijnink Casper W H , Thim Troels , van der Heijden Dirk Jan , Klem Igor , Al-Lamee Rasha , Vos Jacqueline L , Koop Yvonne , Dijkgraaf Marcel G W , Beijk Marcel A M , Kim Raymond J , Davies Justin , Raposo Luis , Baptista Sérgio B , Escaned Javier , Piek Jan J , Maeng Michael , van Royen Niels , Nijveldt Robin
Published: January 2021

Introduction

Recent randomised clinical trials showed benefit of non-culprit lesion revascularisation in ST-elevation myocardial infarction (STEMI) patients. However, it remains unclear whether revascularisation should be performed at the index procedure or at a later stage.

Methods and analysis

The instantaneous wave-free ratio (iFR) Guided Multivessel Revascularisation During Percutaneous Coronary Intervention for Acute Myocardial Infarction trial is a multicentre, randomised controlled prospective open-label trial with blinded evaluation of endpoints. After successful primary percutaneous coronary intervention (PCI), eligible STEMI patients with residual non-culprit lesions are randomised, to instantaneous wave-free ratio guided treatment of non-culprit lesions during the index procedure versus deferred cardiac MR-guided management within 4 days to 6 weeks. The primary endpoint of the study is the combined occurrence of all-cause death, recurrent myocardial infarction and hospitalisation for heart failure at 12 months follow-up. Clinical follow-up includes questionnaires at 3 months and outpatient visits at 6 months and 12 months after primary PCI. Furthermore, a cost-effectiveness analysis will be performed.

Ethics and dissemination

Permission to conduct this trial has been granted by the Medical Ethical Committee of the Amsterdam University Medical Centres (loc. VUmc, ID NL60107.029.16). The primary results of this trial will be shared in a main article and subgroup analyses or spin-off studies will be shared in secondary papers.

Trial registration number

NCT03298659.
Symptom Screening in Pediatrics Tool in children and adolescents with high-risk malignancies: a pilot study
Authors: Szepetowski Sarah , Saultier Paul , Andre Nicolas , Pauly Vanessa , Dupuis L. Lee , Sung Lillian , Revon-Rivière Gabriel
Published: January 2021

Objective

Childhood and adolescent cancer can result in high burden of distressing symptoms, particularly in high-risk malignancies. The Symptom Screening in Pediatrics Tool (SSPedi) is a reliable and valid approach to measure bothersome symptoms in paediatric patients receiving cancer treatments. Objective was to describe the feasibility of using SSPedi administration among paediatric patients with high-risk malignancies.

Methods

We conducted a single-centre, cross-sectional study of patients aged 8–18 years with high-risk malignancies in a French paediatric oncology unit. Patients self-reported the degree of bothersome symptoms using SSPedi and difficulty with SSPedi completion. The total SSPedi Score ranging from 0 to 60 (where 60 is worst) and most common moderately bothersome symptoms (scored ≥2 on 0–4 Likert Scale) were described. Feasibility was defined as more than 75% of patients agreeing to participate and more than 90% completion of SSPedi questionnaire.

Results

Out of 16 patients approached, 1 declined participation. Median age was 13 years (IQR 8–19). All were able to self-report SSPedi without difficulty. Patients experienced a median number of 6 (range 0–15) bothersome symptoms (score >0). The mean total SSPedi Score was 12 (SD=9.4). Most common moderately bothersome symptoms were pain (8/15), changes in hunger (8/15) and feeling tired (7/15).

Conclusion

Patient-reported symptom assessment among children and adolescents with high-risk malignancies is feasible using SSPedi. These patients experience a high burden of bothersome symptoms.
Preventing first births among adolescents in Mexico City’s public abortion programme
Authors: Darney Blair G , Fuentes-Rivera Evelyn , Saavedra-Avendano Biani , Sanhueza-Smith Patricio , Schiavon Raffaela
Published: January 2021

Introduction

We examined parity and age among women seeking an abortion in Mexico City’s public first-trimester abortion programme, Interrupcion Legal de Embarazo (ILE). We hypothesised that younger women, especially students, used abortion to prevent first births while older women used abortion to limit births.

Methods

We used clinical data from a sample of 47 462 women who had an abortion between 2007 and 2016 and classified them as nulliparous or parous according to previous births prior to the abortion. We used logistic regression to identify sociodemographic and clinical factors associated with using abortion to prevent a first birth (nulliparous) versus limiting births (parous) and calculated absolute multivariable predicted probabilities.

Results

Overall, 41% of abortions were in nulliparous women seeking to prevent a first birth, and 59% were in women who already had one or more children. The adjusted probability of using abortion to prevent a first birth was 80.4% (95% CI 78.3 to 82.4) for women aged 12–17 years and 54.3% (95% CI 51.6 to 57.0) for women aged 18–24 years. Adolescents (aged 12–17 years) who were employed or students had nearly 90% adjusted probability of using abortion to prevent a first birth (employed 87.8%, 95% CI 82.9 to 92.8; students 88.5%, 95% CI 82.9 to 94.1). At all ages, employed women and students had higher probabilities of using abortion to prevent a first birth compared with unemployed women and women who work in the home.

Conclusion

Legal first-trimester abortion services in Mexico can help prevent first births in adolescents, especially students.
Evaluation of Mesenteric Artery Disease in Patients with Severe Aortic Valve Stenosis
Authors: Idil Soylu Aysegul , Avcıoglu Ufuk , Uzunkaya Fatih , Soylu Korhan
Published: January 2021

The aim of this study is to evaluate the mesenteric artery stenosis (MAS) in routinely performed CT angiography (CTA) of patients with severe aortic stenosis (AS) planned for transcatheter aortic valve implantation (TAVI) before the procedure. Patients with AS (AS group) who routinely underwent CTA before the TAVI procedure due to severe AS and patients who had CTA for other indications (control group) were retrospectively and sequentially scanned. The demographic characteristics of the patients in both groups were similar. Calcification and stenosis in the mesenteric arteries were recorded according to the localization of celiac truncus, superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). Class 0-3 classification was used for calcification score. Stenoses with a stenosis degree ≥50% were considered as significant. A total of 184 patients, 73 patients with severe AS and 111 control groups, were included in the study. SMA and IMA calcification scores of patients with AS were significantly higher than the control group (p=0.035 for SMA and p=0.020 for IMA). In addition, the rate of patients with significant MAS in at least 1 artery (45.2% vs 22.5%, p=0.001) and the rate of patients with significant stenosis in multiple arteries were also significantly higher in the AS group (8.2% vs 1.8%, p=0.037). According to the study results, patients with AS are at a higher risk for MAS. Chronic mesenteric ischemia should be kept in mind in patients with AS who have symptoms such as non-specific abdominal pain and weight loss.