bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a high-temperature double-layer bulge test for failure prediction in gas-based hot forming of a high-strength aluminium alloy
Authors: Teeuwen T , Baru N K , Tilly K J , Bailly D , Hirt G
Published: May 2022

In order to meet the continuously increasing environmental concerns, automotive lightweight concepts of replacing steels with high strength aluminium alloys are one promising solution. Therefore, complex automotive structural components manufactured with new processes like rapid gas-based hot sheet metal forming can become a key factor from a forming technology point of view. A product and process development phase, which is mainly assisted by numerical simulations, mandates knowledge of the material forming limits under the process conditions. The aim of this work is to determine the FLD of a 6xxx precipitation-hardening aluminium alloy within the solution heat treatment temperature range under gas-based hot forming process conditions. For this purpose, a hydraulic double-layered bulge test, as introduced by Banabic, is used as the basis and a high-temperature test setup as well as a characterization methodology are established. FE simulations are utilized to optimize the specimen geometries aiming at specific strain paths. Experiments are conducted with the optimized specimen geometries and the high-temperature FLD is extracted. The FLD is further used in simulations for process parameter identification for failure-free gas-based hot forming of a laboratory scale benchmark component. Experimental validations showed the reliability of the methodology and the determined FLD for failure prediction in the novel forming process.
Accurate plane strain compression test validation
Authors: Neag Adriana , Hu Qifan , Balan Tudor
Published: May 2022

Large strain characterization of sheet metals has become increasingly important with the generalization of advanced high strength steels, for which the tensile test provides data over a very reduced strain range. Among the numerous alternative characterization tests, the plane strain compression test (PSCT) requires a small amount of material and classical testing machine and acquisition. PSCT was mainly used for hot forming characterization, but recently it has been proved sufficiently accurate for application in cold metal forming. This work provides an in-depth validation of the PSCT by means of the finite element method. When converting the PSCT force-displacement curve into a stress-strain curve (flow curve), several analytical corrections are applied. Several sets of such corrections terms were proposed in the literature, some of which are consistently used by all authors, while others being only used in some papers. The FE simulation of the test was used in order to validate these correction terms and their hypotheses. The originality of the approach is the design of a sequence of test configurations which allow for the individual validation of each and every one of the correction terms concerning the effect of several test parameters. The FE simulations showed that the analytical exploitation of the PSCT provides a very good accuracy. They helped identifying the most suitable correction terms to consider.
Influence of criteria on the determination of forming limits in thickness reduced cruciform specimens
Authors: Wang Z , Guines D , Leotoing L
Published: May 2022

Biaxial tensile test methods using cruciform specimens have been drawing attention as an effective approach to characterize sheet metal formability. The cruciform specimens usually adopt a thickness reduction at the central area to achieve a relatively large strain gradient for localized necking and fracture investigation. For conventional tests, many criteria have been proposed to determine the forming limits at necking, however, none has been widely accepted and applied to the cruciform specimens with non-uniformed thickness reduction. Therefore, in this work, different existing necking criteria are applied and discussed for numerical procedure in order to define an appropriate necking criterion for the thickness reduced cruciform specimens. AA6061-T4 sheet with a thickness of 2mm is used as a target material. The predicted forming limit curves are compared for different criteria, and the feasibility of each criterion is discussed in detail. Thanks to two dedicated specimens proposed by the authors, forming limits are determined for a wide range of strain states.
Investigation on tool properties for the production of components with micro textured surfaces
Authors: Reck M , Merklein M
Published: May 2022

Defined surface micrcotextures offer potential for the friction reduction in elastohydrodynamic contacts and can thus increase the energy efficiency of technical systems. The production of prostheses, where microtextured surfaces can provide anti-bacterial effects is another application area. To manufacture these components economically in large quantities, forming processes are to be aimed at. Since lightweight parts are crucial in most application areas, the forming of sheet metal is the subject of current research. A major aspect of the presented investigation is the behavior of tool materials for the production of such microtextured sheet metal parts. Applying microtextures of varying geometries to the tools is a key challenge. Limitations in the accuracy of electrical discharge machining processes for the fabrication of micro cylinders, prisms and cuboids are therefore analyzed on the high-speed steels 1.3343 and 1.3244. In addition, the tool surfaces are characterized regarding their friction properties with case hardening steel as a contact partner. In this paper, the tool friction is analyzed for the steel 1.7131 (16MnCr5) with an initial sheet thickness of t0 = 2.4 mm, which is often utilized for high-wear applications due to its high strength and toughness. In this context, the friction behavior of the wax-containing lubricant Beruforge 150 DL made for bulk forming processes is compared with zinc-free high-performance lubricants Raziol CLF 65-400 of varying viscosity.
TriboForm® software evaluation for ArcelorMittal Steel Products
Authors: Bouzid A , Bour H
Published: May 2022

In numerical simulations, input data should be correctly defined to enable reliable numerical predictions, close to experimental observations. The purpose of this study is to better take into account the tribological behaviour of ArcelorMittal steel products during the stamping process. TriboForm® is an important additional software solution for the simulation of tribology, friction, and lubrication in sheet metal forming process and enables the generation of multiple friction models. A comparison between experimental observations and numerical predictions was investigated for three ArcelorMittal steel grades (CR4-GI, CR180BH-GI+NIT and CR440Y780T-DH-GI) on several stamping parts. This study illustrates the interest of TriboForm® friction law compared to a standard and constant predefined friction coefficient.
Towards a real-time tool state detection in sheet metal forming processes validated by wear classification during blanking
Authors: Kubik C , Molitor D A , Rojahn M , Groche P
Published: May 2022

The potential of data for inline detection of changes in the physical state of sheet metal forming processes has been proven over the last decade. However, with production rates exceeding 300 parts per minute the time available for a workpiece-related processing of sensor data is reduced. Therefore, the analysis of large data sets is outsourced to the cloud taking advantage of the high computing power provided there. But within this cloud-based computing paradigm, the speed of data transmission hinders real-time analysis of data and causes latency between fault detection and its occurrence. To overcome this bottleneck, this study aims to evaluate a data-based monitoring (DBM) approach for estimating process states in high speed sheet metal forming in terms of their suitability for a decentralized analysis at the edge. Thereby, the DBM is evaluated according to the model accuracy and the absolute computing time. In order to quantify these key performance parameters and the applicability of the DBM on edge devices, a classification of 16 wear states during blanking is considered. Based on the key performance parameters, an optimal DBM approach for decentralized analysis is proposed and an empirical formulation is provided to estimate the absolute computing time depending on the computational resources used for data processing.
On the reliability of yield functions in deep drawing simulations
Authors: Ghiabakloo H , Manopulo N , Mora J , Carleer B , Van Bael A
Published: May 2022

In sheet metal forming simulations, the yield functions are usually calibrated based on experimental data, and validated by comparing the modelled and measured r-values and (in more advanced models) yield stresses along various in-plane directions. The fitted yield function should ideally reproduce (or interpolate) all the experimental values used for the fitting. However, this requirement does not guarantee accurate results in a forming process simulation, and it can even lead to unexpected results. The performance of a yield function, in addition to the fitting procedure, depends on the active loading modes which the material experiences during the simulation. The active loading modes are in turn determined by the die geometry as well as the process parameters like blank holder force and lubrication. As a consequence, the performance of a yield function, which is fitted to simple experimental data, is not identical for different forming conditions. Therefore, the application of each model is usually limited to a range of materials and processes, and this applicability is often evaluated based on experience. In the present study, we examine three phenomenological yield functions and a new crystal plasticity based material model for cup drawing process simulation with an AA6016-T4 aluminium alloy. These functions are different in their input data types used for the calibration. The results surprisingly shows that the models with more experimental data (in particular, yield stresses in different directions) in their formulation not only predict unexpectedly wrong results, but also show strong sensitivity to some of those additional input data and even to modelling parameters like the friction coefficient.
Influence of the forming process on springback
Authors: Durmaz U , Heibel S , Schweiker T , Prabhakar A. , Merklein M
Published: May 2022

The use of advanced high-strength steels (AHSS) is associated with increased springback and represents a great challenge for today’s press shops with regard to the dimensional accuracy of cold-formed sheet metal parts. Springback, its appearance and characteristics are mainly dependent on the stress state introduced by the forming process and part geometry before opening the tools. With the aim of determining the influence of the forming process on springback, sheet metal forming simulation is used in this contribution to analyze a hat profile from a high-strength dual-phase steel (DH1000) by three different forming processes: crash forming, bending and drawing. For this purpose, the stresses generated by these processes and resulting springback are examined considering the respective forming history. The results show the strong influence of the material flow controlled by the process and tool geometry on the stress state before springback, which leads to significant differences in the springback of the hat profile among the forming processes: springback increases from crash forming to bending and drawing.
Assembly simulation development and validation project with industrial applications
Authors: Tinti Fabrizio , Fontana Marco , Scintilla Leonardo Daniela , Mirabile Annalisa , Carleer Bart
Published: May 2022

Full digitalization has been applied more intensively in the automotive industry. The virtual engineering of single part is established since many years. Currently, the digital process chain is expanding to the assembly process. The assembly engineering teams should be effectively supported to define the assembly process; the assembly process should make products that fulfil the required quality requirements. A detailed simulation representing the future assembly process has to be setup. In an early phase based on CAD data, in the course of the engineering process the model can be enriched with forming simulation data and even real measurement data. Based on the assembly definition, critical issues can be identified and fixed already in the virtual world. Detailed evaluation of the geometrical deviation of the assembly can be made. This methodology is validated on an industrial automotive component.
Evaluating the influence of the deformation of the forming tools in the thickness distribution along the wall of a cylindrical cup
Authors: Oliveira M C , Neto D M , Pereira A.F.G. , Alves J L , Menezes LF
Published: May 2022

The Swift cup drawing test has been adopted for evaluating sheet metal deformation properties, namely the material formability assessed through the limiting drawing ratio. Since the strain path of the points located on the flange is between uniaxial compression and pure shear, this region is subjected to thickening. If the thickness of the drawn flange is larger than the gap between the punch and the die, cup wall ironing will occur. Therefore, the ironing forces can lead to significant elastic deformation of the forming tools (punch and die). The main objective of this study is to evaluate numerically the deformation of the forming tools during the deep drawing-ironing process of a cylindrical cup. Then, the effect of that deformation on both the earing profile and the evolution of thickness along the circumferential direction, at different heights, is analysed. The material studied is the AA 6016-T4. Since both the thickness strain and the earing profile are strongly influenced by the adopted yield criterion, the study considers the classical quadratic one proposed by Hill and a non-quadratic proposed by Cazacu and Barlat. The process conditions considered are the ones from EXACT, the ESAFORM Benchmark 2021, enabling the comparison with experimental results.
Advanced part design method for springback minimization of stamped sheet metal car body components
Authors: Birkert A , Hartmann B , Nowack M , Petker A , Scholle M , Zimmermann P , Kraft T.
Published: May 2022

The requirements for high-strength and low-weight car body structures prove challenging for the stamping process and cause growing problems with the elastic springback. Compensation approaches such as the geometrical adjustment of the stamping dies by the amount of and in opposite direction to the springback can be an effective solution in many cases. However, this approach can only lead to satisfactory results if the scatter of the springback is considered, controlled and in the best case reduced. The reduction of the scatter can be provoked by adaption of the part design. Therefore, different methods such as the topology optimization method, the so-called line-of-force method and shape optimization can be applied. In the present work an advanced topology optimization method is suggested. Based on the decomposition of the springback deformation into membrane and bending components, the most efficient optimization of the part design is found relying on unconventional topology optimization. For the proposed adapted topology optimization approach the excellent results are also confirmed when applied to the industry-relevant case of a truck rear panel.
Effect of Initial Temper on the Warm Forming Characteristics of a High Strength 7000-series Al-Zn-Mg-Cu Alloy
Authors: DiCecco S , Di Ciano M , Butcher C , Worswick M
Published: May 2022

In this work, the formability of a developmental 7000-series copper containing aluminium alloy was assessed at room temperature (RT), 150°C, 175°C and 200°C in pre-aged (PA), peak-aged (T6) and overaged (T76) tempers using Nakazima tests with stereoscopic digital image correlation (DIC) strain measurement. The limit strains were identified using a novel curvature-based approach to detect the formation of an acute neck. The tensile mechanical properties in these warm forming processing routes were characterized with and without a paint bake cycle. Finally, a thermo-mechanical tensile simulator was used to evaluate the constitutive response of the PA and T76 tempers as a function of strain-rate and time at 175°C. Formability results found the selected PA temper to have a good room temperature formability and a mild positive response to the selected warm-forming cycles. The T6 and T76 tempers both exhibited increases in formability in response to warm forming. The PA temper had a significant positive response to short-duration warm forming and subsequent paint baking, with the yield strength increasing from 420 MPa to 512 MPa following this thermal cycle. For the T6 temper, the warm-forming cycle showed a trend characteristic of retrogression and re-aging, with the warm-forming cycle dropping the yield strength from 566 MPa to 534 MPa and the subsequent paint-bake re-aging to 554 MPa. The effect of aging during pre-heating prior to warm forming on the warm constitutive response of the PA and T76 tempers was also investigated. Both tempers exhibited rather different aging responses to short-duration thermal cycles. In the PA temper, this manifested as an increase in at-temperature yield strength and loss of hardening rate. In contrast, the T76 temper exhibited a drop in strength since this temper is already over-aged prior to warm forming. Both the PA and T76 tempers showed comparable at-temperature strain-rate sensitivity.
Prediction of risk-associated genes and high-risk liver cancer patients from their mutation profile: benchmarking of mutation calling techniques
Authors: Patiyal Sumeet , Dhall Anjali , Raghava Gajendra P S
Published: May 2022

Identification of somatic mutations with high precision is one of the major challenges in the prediction of high-risk liver cancer patients. In the past, number of mutations calling techniques has been developed that include MuTect2, MuSE, Varscan2, and SomaticSniper. In this study, an attempt has been made to benchmark the potential of these techniques in predicting the prognostic biomarkers for liver cancer. Initially, we extracted somatic mutations in liver cancer patients using Variant Call Format (VCF) and Mutation Annotation Format (MAF) files from the cancer genome atlas. In terms of size, the MAF files are 42 times smaller than VCF files and containing only high-quality somatic mutations. Furthermore, machine learning-based models have been developed for predicting high-risk cancer patients using mutations obtained from different techniques. The performance of different techniques and data files has been compared based on their potential to discriminate high- and low-risk liver cancer patients. Based on correlation analysis, we selected 80 genes having significant negative correlation with the overall survival of liver cancer patients. The univariate survival analysis revealed the prognostic role of highly mutated genes. Single gene-based analysis showed that MuTect2 technique-based MAF file has achieved maximum hazard ratio (HRLAMC3) of 9.25 with P-value of 1.78E-06. Further, we developed various prediction models using risk-associated top-10 genes for each technique. Our results indicate that MuTect2 technique-based VCF files outperform all other methods with maximum Area Under the Receiver-Operating Characteristic curve of 0.765 and HR = 4.50 (P-value = 3.83E-15). Eventually, VCF file generated using MuTect2 technique performs better among other mutation calling techniques for the prediction of high-risk liver cancer patients. We hope that our findings will provide a useful and comprehensive comparison of various mutation-calling techniques for the prognostic analysis of cancer patients. In order to serve the scientific community, we have provided a Python-based pipeline to develop the prediction models using mutation profiles (VCF/MAF) of cancer patients. It is available on GitHub at https://github.com/raghavagps/mutation_bench.
MLBioIGE: integration and interplay of machine learning and bioinformatics approach to identify the genetic effect of SARS-COV-2 on idiopathic pulmonary fibrosis patients
Authors: Tanzir Mehedi Sk , Ahmed Kawsar , Bui Francis M , Rahaman Musfikur , Hossain Imran , Tonmoy Tareq Mahmud , Limon Rakibul Alam , Ibrahim Sobhy M , Moni Mohammad Ali
Published: May 2022

SARS-CoV-2, the virus that causes COVID-19, is a current concern for people worldwide. The virus has recently spread worldwide and is out of control in several countries, putting the outbreak into a terrifying phase. Machine learning with transcriptome analysis has advanced in recent years. Its outstanding performance in several fields has emerged as a potential option to find out how SARS-CoV-2 is related to other diseases. Idiopathic pulmonary fibrosis (IPF) disease is caused by long-term lung injury, a risk factor for SARS-CoV-2. In this article, we used a variety of combinatorial statistical approaches, machine learning, and bioinformatics tools to investigate how the SARS-CoV-2 affects IPF patients’ complexity. For this study, we employed two RNA-seq datasets. The unique contributions include common genes identification to identify shared pathways and drug targets, PPI network to identify hub-genes and basic modules, and the interaction of transcription factors (TFs) genes and TFs–miRNAs with common differentially expressed genes also placed on the datasets. Furthermore, we used gene ontology and molecular pathway analysis to do functional analysis and discovered that IPF patients have certain standard connections with the SARS-CoV-2 virus. A detailed investigation was carried out to recommend therapeutic compounds for IPF patients affected by the SARS-CoV-2 virus.
Chlorhexidine and Mupirocin for Clearance of Methicillin-Resistant Staphylococcus aureus Colonization After Hospital Discharge: A Secondary Analysis of the Changing Lives by Eradicating Antibiotic Resistance Trial
Authors: Miller Loren G , Singh Raveena , Eells Samantha J , Gillen Daniel , McKinnell James A , Park Steven , Tjoa Tom , Chang Justin , Rashid Syma , Macias-Gil Raul , Heim Lauren , Gombosev Adrijana , Kim Diane , Cui Eric , Lequieu Jennifer , Cao Chenghua , Hong Suzie S , Peterson Ellena M , Evans Kaye D , Launer Bryn , Tam Steven , Bolaris Michael , Huang Susan S
Published: May 2022

Background

The CLEAR Trial demonstrated that a multisite body decolonization regimen reduced post-discharge infection and hospitalization in methicillin-resistant Staphylococcus aureus (MRSA) carriers. Here, we describe decolonization efficacy.

Methods

We performed a large, multicenter, randomized clinical trial of MRSA decolonization among adult patients after hospital discharge with MRSA infection or colonization. Participants were randomized 1:1 to either MRSA prevention education or education plus decolonization with topical chlorhexidine, oral chlorhexidine, and nasal mupirocin. Participants were swabbed in the nares, throat, axilla/groin, and wound (if applicable) at baseline and 1, 3, 6, and 9 months after randomization. The primary outcomes of this study are follow-up colonization differences between groups.

Results

Among 2121 participants, 1058 were randomized to decolonization. By 1 month, MRSA colonization was lower in the decolonization group compared with the education-only group (odds ration [OR] = 0.44; 95% confidence interval [CI], .36–.54; P ≤ .001). A similar magnitude of reduction was seen in the nares (OR = 0.34; 95% CI, .27–.42; P < .001), throat (OR = 0.55; 95% CI, .42–.73; P < .001), and axilla/groin (OR = 0.57; 95% CI, .43–.75; P < .001). These differences persisted through month 9 except at the wound site, which had a relatively small sample size. Higher regimen adherence was associated with lower MRSA colonization (P ≤ .01).

Conclusions

In a randomized, clinical trial, a repeated post-discharge decolonization regimen for MRSA carriers reduced MRSA colonization overall and at multiple body sites. Higher treatment adherence was associated with greater reductions in MRSA colonization.
Malaria in Refugee Children Resettled to a Holoendemic Area of Sub-Saharan Africa
Authors: Hauser Manuela , Kabuya Jean-Bertin B , Mantus Molly , Kamavu Luc K , Sichivula James L , Matende Wycliffe M , Fritschi Nora , Shields Timothy , Curriero Frank , Kvit Anton , Chongwe Gershom , Moss William J , Ritz Nicole , Ippolito Matthew M
Published: May 2022

Background

Malaria is a leading cause of morbidity and mortality in refugee children in high-transmission parts of Africa. Characterizing the clinical features of malaria in refugees can inform approaches to reduce its burden.

Methods

The study was conducted in a high-transmission region of northern Zambia hosting Congolese refugees. We analyzed surveillance data and hospital records of children with severe malaria from refugee and local sites using multivariable regression models and geospatial visualization.

Results

Malaria prevalence in the refugee settlement was similar to the highest burden areas in the district, consistent with the local ecology and leading to frequent rapid diagnostic test stockouts. We identified 2197 children hospitalized for severe malaria during the refugee crisis in 2017 and 2018. Refugee children referred from a refugee transit center (n = 63) experienced similar in-hospital mortality to local children and presented with less advanced infection. However, refugee children from a permanent refugee settlement (n = 110) had more than double the mortality of local children (P < .001), had lower referral rates, and presented more frequently with advanced infection and malnutrition. Distance from the hospital was an important mediator of the association between refugee status and mortality but did not account for all of the increased risk.

Conclusions

Malaria outcomes were more favorable in refugee children referred from a highly outfitted refugee transit center than those referred later from a permanent refugee settlement. Refugee children experienced higher in-hospital malaria mortality due in part to delayed presentation and higher rates of malnutrition. Interventions tailored to the refugee context are required to ensure capacity for rapid diagnosis and referral to reduce malaria mortality.
Repair with a pulmonary neovalve in tetralogy of Fallot: does this avoid ventricular dysfunction?
Authors: Guerrero Albert Franz , Pineda-Rodríguez Ivonne Gisel , Palacio Andres Mauricio , Obando Carlos Eduardo , Chalela Tomas , Camacho Jaime , Villa Carlos , Umaña Juan Pablo , Sandoval-Reyes Nestor Fernando
Published: May 2022

OBJECTIVES

Given the anatomical variations of tetralogy of Fallot (TOF), different surgical techniques can be used to achieve correction. Transannular patches (TAPs) are the most commonly used technique; they are associated with right ventricular dysfunction, the incidence of which can be reduced through pulmonary valve preservation.

METHODS

Between January 2010 and July 2019, we performed 274 surgical corrections of tetralogy of Fallot at Fundación Cardioinfantil; 63 patients (23%) underwent repair with a TAP in addition to a pulmonary neovalve (Group I), 66 patients (24.1%) received a TAP without a pulmonary valve (Group II) and 145 patients (52.9%) had a repair with valve preservation (Group III). We analysed patient’s characteristics before, during and after surgery at a 30-day follow-up.

RESULTS

We found that patients in Group III were older (P = 0.04). Group II had the lowest level of O2 saturation before surgery (82%, P = 0.001). Cardiopulmonary bypass and aortic cross-clamp times were longer in Group I (P < 0.001). Right ventricular dysfunction was less frequent in Group III (15.9%, P = 0.011). Severe residual pulmonary regurgitation was more common in Group II (21.9%, P = 0.001).

CONCLUSIONS

Preservation of the pulmonary valve is an important factor for immediate postoperative management of tetralogy of Fallot. Patients who were repaired with a TAP with or without a pulmonary neovalve had a higher incidence of right ventricular dysfunction than those with pulmonary valve preservation.
The impact of urbanization on outcrossing rate and population genetic variation in the native wildflower, Impatiens capensis
Authors: Rivkin L Ruth , Johnson Marc T J
Published: May 2022

Cities are one of the fastest growing ecosystems on the planet, and conserving urban biodiversity is of primary importance. Urbanization increases habitat fragmentation and may be particularly problematic for native plant species which often exist in small, remnant populations in cities. We studied the effects of urbanization on Impatiens capensis, a self-compatible native wildflower, which is an important nectar and pollen source for native bees and hummingbirds. We sampled I. capensis from six populations located in urban and rural habitats in Toronto, Ontario, Canada. We sequenced the DNA of 43 families (N = 86 individuals) using genotype-by-sequencing to obtain 5627 single nucleotide polymorphisms. From each parent and offspring, we estimated individual outcrossing rates, population-level genetic diversity and genetic structure among populations. We found that 95% of plants were outcrossed, and populations were genetically differentiated, where urban populations contained a subset of the genetic variation found in rural populations. Urban populations exhibited lower genetic diversity than rural populations, and we detected a relationship between population census size and habitat on genetic diversity. Despite high outcrossing rates, our results suggest that urbanization reduces the genetic diversity of I. capensis populations, potentially increasing the vulnerability of these populations to long-term population declines and extirpation in response to urbanization.
Acute Fatigue Responses to Occupational Training in Military Personnel: A Systematic Review and Meta-Analysis
Authors: Heilbronn Brian , Doma Kenji , Sinclair Wade , Connor Jonathan , Irvine-Brown Lachlan , Leicht Anthony
Published: May 2022

Introduction

Military personnel are required to undertake rigorous physical training to meet the unique demands of combat, often leading to high levels of physiological stress. Inappropriate recovery periods with these high levels of physical stress may result in sub-optimal training and increased risk of injury in military personnel. However, no reviews have attempted to examine the magnitude of training-induced stress following military training activities. The aim of this systematic review was to assess the magnitude of physiological stress (physical, hormonal, and immunological) following task-specific training activities in military personnel.

Methods

An extensive literature search was conducted within CINAHL, PubMed, Scopus, SportDiscus, and Web of Science databases with 7,220 records extracted and a total of 14 studies eligible for inclusion and evaluation. Study appraisal was conducted using the Kmet scale. Meta-analysis was conducted via forest plots, with standard mean difference (SMD, effect size) and inter-trial heterogeneity (I2) calculated between before (preactivity) and after (12–96 hours postactivity) military-specific activities for biomarkers of physiological stress (muscle damage, inflammation, and hormonal) and physical performance (muscular strength and power).

Results

Military training activities resulted in significant levels of muscle damage (SMD = −1.28; P = .003) and significant impairments in strength and power (SMD = 0.91; P = .008) and testosterone levels (SMD = 1.48; P = .05) up to 96 hours postactivity. There were no significant differences in inflammation (SMD = −0.70; P = .11), cortisol (SMD = −0.18; P = .81), or insulin-like growth factor 1 (SMD = 0.65; P = .07) when compared to preactivity measures.

Conclusions

These findings indicate that assessments of muscle damage, anabolic hormones like testosterone, strength, and power are effective for determining the level of acute stress following military-specific activities. With regular monitoring of these measures, appropriate recovery periods may be implemented to optimize training adaptations and occupational performance, with minimal adverse training responses in military personnel.
Priors on red galaxy stochasticity from hybrid effective field theory
Authors: Kokron Nickolas , DeRose Joseph , Chen Shi-Fan , White Martin , Wechsler Risa H
Published: May 2022

We investigate the stochastic properties of typical red galaxy samples in a controlled numerical environment. We use halo occupation distribution (HOD) modelling to create mock realizations of three separate bright red galaxy samples consistent with data sets used for clustering and lensing analyses in modern galaxy surveys. Second-order Hybrid Effective Field Theory (HEFT) is used as a field-level forward model to describe the full statistical distribution of these tracer samples, and their stochastic power spectra are directly measured and compared to the Poisson shot-noise prediction. While all of the galaxy samples we consider are hosted within haloes with sub-Poisson stochasticity, we observe that the galaxy samples themselves possess stochasticities that range from sub-Poisson to super-Poisson, in agreement with predictions from the halo model. As an application of our methodology, we place priors on the expected degree of non-Poisson stochasticity in cosmological analyses using such samples. We expect these priors will be useful in reducing the complexity of the full parameter space for future analyses using second-order Lagrangian bias models. More generally, the techniques outlined here present the first application of HEFT methods to characterize models of the galaxy–halo connection at the field level, revealing new connections between once-disparate modelling frameworks.
GLADE+ : an extended galaxy catalogue for multimessenger searches with advanced gravitational-wave detectors
Authors: Dálya G , Díaz R , Bouchet F R , Frei Z , Jasche J , Lavaux G , Macas R , Mukherjee S , Pálfi M , de Souza R S , Wandelt B D , Bilicki M , Raffai P
Published: May 2022

We present GLADE+, an extended version of the GLADE galaxy catalogue introduced in our previous paper for multimessenger searches with advanced gravitational-wave detectors. GLADE+ combines data from six separate but not independent astronomical catalogues: the GWGC, 2MPZ, 2MASS XSC, HyperLEDA, and WISExSCOSPZ galaxy catalogues, and the SDSS-DR16Q quasar catalogue. To allow corrections of CMB-frame redshifts for peculiar motions, we calculated peculiar velocities along with their standard deviations of all galaxies having B-band magnitude data within redshift z = 0.05 using the ‘Bayesian Origin Reconstruction from Galaxies’ formalism. GLADE+ is complete up to luminosity distance $d_L=47^{+4}_{-2}$ Mpc in terms of the total expected B-band luminosity of galaxies, and contains all of the brightest galaxies giving 90 per cent of the total B-band and K-band luminosity up to dL ≃ 130 Mpc. We include estimations of stellar masses and individual binary neutron star merger rates for galaxies with W1 magnitudes. These parameters can help in ranking galaxies in a given gravitational wave localization volume in terms of their likelihood of being hosts, thereby possibly reducing the number of pointings and total integration time needed to find the electromagnetic counterpart.
Numerical investigation of non-Gaussianities in the phase and modulus of density Fourier modes
Authors: Qin Jian , Pan Jun , Yu Yu , Zhang Pengjie
Published: May 2022

We numerically investigate the non-Gaussianities in the late-time cosmological density field in Fourier space. We explore various statistics, including the two- and three-point probability distribution function (PDF) of phase and modulus, and their two- and three-point correlation function. Significant non-Gaussianity is observed for certain configurations. Comparing the measurement from simulation with the theoretical expansion prediction, we find that for (600 Mpc h-1)3 volume, the $\mathcal {O}(V^{-1/2})$ order term alone is sufficiently accurate to describe all the measured non-Gaussianities in not only the PDFs, but also the correlations. We also numerically find that the phase-modulus cross-correlation contributes $\sim 50{{\ \rm per\ cent}}$ to the bispectrum, further verifying the accuracy of the $\mathcal {O}(V^{-1/2})$ order prediction. This work demonstrates that the non-Gaussianity of cosmic density field is simpler in Fourier space, and may facilitate the data analysis in the era of precision cosmology.
The sphere of influence of the bright central galaxies in the diffuse light of SDSS clusters
Authors: Chen Xiaokai , Zu Ying , Shao Zhiwei , Shan Huanyuan
Published: May 2022

The bright central galaxies (BCGs) dominate the inner portion of the diffuse cluster light, but it is still unclear where the intracluster light (ICL) takes over. To investigate the BCG–ICL transition, we stack the images of ∼3000 clusters between 0.2 < $\mathit{ z}$ < 0.3 in the Sloan Digital Sky Survey  (SDSS) gri bands, and measure their BCG + ICL stellar surface mass profile $\Sigma _{*}^{\texttt {B+I}}$ down to $3{\times }10^4\,\mathrm{ M}_{\odot }\,\mathrm{kpc}^{-2}$ at $R{\simeq }1\, \mathrm{Mpc}$ (∼32 mag arcsec−2 in the r-band). We develop a physically motivated method to decompose $\Sigma _{*}^{\texttt {B+I}}$ into three components, including an inner de Vaucouleurs’ profile, an outer ICL that follows the dark matter distribution measured from weak lensing, and an intriguing transitional component between 70 and 200 kpc. To investigate the origin of this transition, we split the clusters into two subsamples by their BCG stellar mass $M_*^{\mathrm{BCG}}$ (mass enclosed roughly within 50 kpc) while making sure they have the same distribution of satellite richness. The $\Sigma _{*}^{\texttt {B+I}}$ profiles of the two subsamples differ by more than a factor of 2 at R < 50 kpc, consistent with their 0.34 dex difference in $M_*^{\mathrm{BCG}}$, whereas on scales beyond 400 kpc, the two profiles converge to the same amplitudes, suggesting a satellite-stripping origin of the outer ICL. Remarkably, however, the discrepancy between the two $\Sigma _{*}^{\texttt {B+I}}$ profiles persists at above $50{{\ \rm per\ cent}}$ level on all scales below 200 kpc, thereby revealing the BCG sphere of influence with radius RSOI ≃ 200 kpc. Finally, we speculate that the surprisingly large sphere of influence of the BCG is tied to the elevated escape velocity profile within rs, the characteristic radius of the dark matter haloes.
Using the bispectrum to probe radio X-ray correlations in GRS 1915+105
Authors: Arur K , Maccarone T J
Published: May 2022

We present the results of bicoherence analysis on observations of GRS 1915+105 that exhibit quasi-periodic oscillations (QPOs). The bicoherence is a higher order statistic that can be used to probe the relation between the phases of a triplet of Fourier frequencies. Despite showing very similar power spectra, the observations exhibit different patterns in their bicoherence, indicating that the QPOs are phase coupled to the noise in different ways. We show that the bicoherence pattern exhibited correlates with the frequency of the QPO, the hardness ratio, as well as the radio properties of the source. In particular, we find that the nature of phase coupling between the QPO and the high and low frequency broad-band components is different between radio quiet, radio plateau, and radio steep conditions. We also investigate the phase lag behaviour of observations with QPO frequency above 2 Hz that show different bicoherence patterns and find statistically significant differences between them, indicating a change in the underlying physical mechanism. Finally, we present a scenario whereby the cooling of the jet electrons by soft photons from the accretion disc could explain the observed correlations between the bicoherence and radio properties.
The driving mode of shock-driven turbulence
Authors: Dhawalikar Saee , Federrath Christoph , Davidovits Seth , Teyssier Romain , Nagel Sabrina R , Remington Bruce A , Collins David C
Published: May 2022

Turbulence in the interstellar medium (ISM) is crucial in the process of star formation. Shocks produced by supernova explosions, jets, radiation from massive stars, or galactic spiral-arm dynamics are amongst the most common drivers of turbulence in the ISM. However, it is not fully understood how shocks drive turbulence, in particular whether shock driving is a more solenoidal (rotational, divergence-free) or a more compressive (potential, curl-free) mode of driving turbulence. The mode of turbulence driving has profound consequences for star formation, with compressive driving producing three times larger density dispersion, and an order of magnitude higher star formation rate than solenoidal driving. Here, we use hydrodynamical simulations of a shock inducing turbulent motions in a structured, multiphase medium. This is done in the context of a laser-induced shock, propagating into a foam material, in preparation for an experiment to be performed at the National Ignition Facility (NIF). Specifically, we analyse the density and velocity distributions in the shocked turbulent medium, and measure the turbulence driving parameter $b=(\sigma _{\rho /\langle \rho \rangle }^{2\Gamma }-1)^{1/2}(1-\sigma _{\rho /\langle \rho \rangle }^{-2})^{-1/2}\mathcal {M}^{-1}\Gamma ^{-1/2}$, with the density dispersion σρ/〈ρ〉, the turbulent Mach number $\mathcal {M}$, and the polytropic exponent Γ. Purely solenoidal and purely compressive driving correspond to b ∼ 1/3 and b ∼ 1, respectively. Using simulations in which a shock is driven into a multiphase medium with structures of different sizes and Γ < 1, we find b ∼ 1 for all cases, showing that shock-driven turbulence is consistent with strongly compressive driving.
A study on the characteristic features of the lunar ionosphere using dual frequency radio science (DFRS) experiment onboard Chandrayaan-2 orbiter
Authors: Tripathi Keshav R , Choudhary R K , Ambili K M , Bindu K R , Manikantan R , Parikh Umang
Published: May 2022

We present ‘first of its kind’ measurements of the enhanced integrated electron density profiles (iEDPs) at the lunar wake and trans-terminator regions using radio occultation (RO) experiments conducted with the dual frequency radio science (DFRS) payload onboard Chandrayaan-2 (CH2) spacecraft. DFRS uses one-way coherent signals at X and S-bands of radio frequencies for RO measurements. Detailed analysis of the results shows that the electron content is large (∼1.5 TECU, with 1 TECU = 1016 m−2) in the lunar wake region compared to the dayside. Large electron content is also seen near lunar polar regions during solar transition periods. These observations are unique in nature as they show post-sunset enhancements in the iEDPs compared to dayside, as reported by earlier missions. These results further confirm recent predictions from the theoretical model for the lunar ionosphere.
Accreting neutron stars: heating of the upper layers of the inner crust
Authors: Shchechilin N N , Gusakov M E , Chugunov A I
Published: May 2022

Neutron stars in low-mass X-ray binaries are thought to be heated up by accretion-induced exothermic nuclear reactions in the crust. The energy release and the location of the heating sources are important ingredients of the thermal evolution models. Here, we present thermodynamically consistent calculations of the energy release in three zones of the stellar crust: at the outer–inner crust interface, in the upper layers of the inner crust (up to the density ρ ≤ 2 × 1012 g cm−3), and in the underlying crustal layers. We consider three representative models of thermonuclear ashes (superburst, extreme rp, and Kepler ashes). The energy release in each zone is parametrized by the pressure at the outer–inner crust interface, Poi, which encodes all uncertainties related to the physics of the deepest inner-crust layers. Our calculations allow us to set new theoretical lower limits on the net energy release (per accreted baryon): Q ≳ 0.28 MeV for extreme rp ashes and Q ≳ 0.43–0.51 MeV for superburst and Kepler ashes. Our results can be directly incorporated into numerical codes and provide an opportunity to constrain Poi by comparing thermal evolution models of accreting neutron stars with observations.
Incidence and extent of disease progression on MRI between surgery and initiation of radiotherapy in glioblastoma patients
Authors: Kraus Ryan D , Weil Christopher R , Frances Su Fan-Chi , Cannon Donald M , Burt Lindsay M , Mendez Joe S
Published: May 2022

Background

A post-operative MRI (MRIpost-op) performed within 72 h is routinely used for radiation treatment planning in glioblastoma (GBM) patients, with radiotherapy starting about 4–6 weeks after surgery. Some patients undergo an additional pre-radiotherapy MRI (MRIpre-RT) about 2–6 weeks after surgery. We sought to analyze the incidence of rapid early progression (REP) between surgery and initiation of radiotherapy seen on MRIpre-RT and the impact on radiation target volumes.

Methods

Patients with GBM diagnosed between 2018 and 2020 who had an MRIpost-op and MRIpre-RT were retrospectively identified. Criteria for REP was based on Modified RANO criteria. Radiation target volumes were created and compared using the MRIpost-op and MRIpre-RT.

Results

Fifty patients met inclusion criteria. The median time between MRIpost-op and MRIpre-RT was 26 days. Indications for MRIpre-RT included clinical trial enrollment in 41/50 (82%), new symptoms in 5/50 (10%), and unspecified in 4/50 (8%). REP was identified in 35/50 (70%) of patients; 9/35 (26%) had disease progression outside of the MRIpost-op-based high dose treatment volumes. Treatment planning with MRIpost-op yielded a median undertreatment of 27.1% of enhancing disease and 11.2% of surrounding subclinical disease seen on MRIpre-RT. Patients without REP had a 38% median volume reduction of uninvolved brain if target volumes were planned with MRIpre-RT.

Conclusion

Given the incidence of REP and its impact on treatment volumes, we recommend using MRIpre-RT for radiation treatment planning to improve coverage of gross and subclinical disease, allow for early identification of REP, and decrease radiation treatment volumes in patients without REP.
The Value of the Information That Can Be Generated: Optimizing Study Design to Enable the Study of Treatments Addressing an Unmet Need for Rare Pathogens
Authors: Dane Aaron , Rex John H , Newell Paul , Stallard Nigel
Published: May 2022

In traditional phase 3 trials confirming safety and efficacy of new treatments relative to a comparator, a 1-sided type I error rate of 2.5% is traditionally used and typically leads to minimum sizes of 300–600 subjects per study. However, for rare pathogens, it may be necessary to work with data from as few as 50–100 subjects. For areas with a high unmet need, there is a balance between traditional type I error and power and enabling feasible studies. In such cases, an alternative 1-sided alpha level of 5% or 10% should be considered, and we review herein the implications of such approaches. Resolving this question requires engagement of patients, the medical community, regulatory agencies, and trial sponsors.