bluuebunny/crossref_metadata_2025_split huggingface dataset:
P‐Hacking, P‐Curves, and the PSM–Performance Relationship: Is There Evidential Value?
Authors: Vogel Dominik , Homberg Fabian 
Published: July 2020

AbstractRecent developments in the social sciences have demonstrated that we cannot uncritically aggregate the published research on a particular effect to conclude about its presence or absence. Instead, questionable research practices such as p‐hacking (conducting additional analyses or collecting new data to obtain significant results) and selective publication of significant results can produce a body of published research that misleads readers even if it contains many significant results. It is, therefore, necessary to assess the evidential value of the research on a certain effect; that is, one must rule out that it is the result of questionable research practices. We introduce the p‐curve method to public administration research and apply it to the research on the relationship between public service motivation (PSM) and individual performance, to demonstrate how the evidential value of a body of published research can be assessed. We find that this particular literature contains evidential value.
High velocity impact of an Fe/Cr/Mn/Ni high entropy alloy
Authors: Hawkins M. Cameron , Thomas Sarah , Hixson Robert , Li Nan , Fensin Saryu 
Published: July 2020

Abstract
A series of shock loading experiments were conducted on High Entropy Alloy (HEA) samples consisting of Fe/Cr/Mn/Ni in weight percentages of 25.2/23.5/24.8/26.5. Characterizing this transition metal alloy is a first step in understanding the shock compression response of this relatively new class of alloy. A single stage light gas gun was used to conduct a series of flyer plate symmetric impact experiments to obtain fundamental dynamic properties. Photonic Doppler Velocimetry (PDV) diagnostics were employed to measure the free surface velocity on the back of each target during dynamic compression. These experiments yielded four data points that are in reasonable agreement with an estimated Hugoniot for the material.
Four-View Split-Image Fragment Tracking in Hypervelocity Impact Experiments
Authors: Watson Erkai , Kunert Nico , Putzar Robin , Maas Hans-Gerd , Hiermaier Stefan 
Published: July 2020

Abstract
Hypervelocity impacts (HVI) often cause significant fragmentation to occur in both target and projectile materials, and is often encountered in space debris and planetary impact applications [1]–[5]. In this paper, we focus on determining the individual velocities and sizes of fragments tracked in high-speed images. Inspired by velocimetry methods such as Particle Image Velocimetry (PIV) [6] and Particle Tracking Velocimetry (PTV) [7] and building on past work [8], we describe the setup and algorithm used for measuring fragmentation data.
Statistical Distributions of the Elastic Moduli of Particle Aggregates at the Mesoscale
Authors: Pekmezi Gerald , Littlefield David , Chareyre Bruno 
Published: July 2020

Abstract
The current work is part of an ongoing effort to couple the Discrete Element Method (DEM), used as a mesoscale method, with Statistical Mechanics in order to construct a framework for the modeling, homogenization, and uncertainty quantification of particulate geomaterials. The aspect of the framework tackled in this work, is the quantification of stress and deformation of heterogenous DE models. Such quantification is necessary to allow DEM to “speak continuum”. DEM is a discrete particle method, wherein the concept of “stress” does not fit naturally, but where each particle pair is considered to interact through discrete forces. Additionally, DEM is an explicit method, and equivalent continuum deformation must be defined in the context of particle kinematics.
Assessment and Validation of Collision “Consequence” Method of Assessing Orbital Regime Risk Posed by Potential Satellite Conjunctions
Authors: Lechtenberg Travis F. , Hejduk Matthew D. 
Published: July 2020

Abstract
Collision risk management theory requires a thorough assessment of both the likelihood and consequence of potential collision events. Satellite conjunction risk assessment has produced a highly-developed theory for assessing the likelihood of collision but typically neglects to account for the consequences of a given collision. While any collision may compromise the operational survival of a space-craft, the amount of debris produced by the potential collision, and therefore the degree to which the orbital corridor may be compromised, can vary greatly among satellite conjunctions. Previous studies leveraged work on satellite collision modeling to develop a method to estimate whether a particular collision is likely to produce a relatively large or relatively small amount of resultant debris. The approximation of the number of debris pieces is dependent on a mass estimation process for the secondary objects utilizing the radar cross section of said object. This study examines the validity of the mass estimation process and establishes uncertainty bounds on the secondary object mass which will be used to best approximate the possible consequences of a prospective collision.
Updates to the DebriSat Project in Support of Improving Breakup Models and Orbital Debris Risk Assessments
Authors: Cowardin Heather , Anz-Meador Phillip , Murray James , Liou J.-C. , Christiansen Eric , Sorge Marlon , Fitz-Coy Norman , Huynh Tom 
Published: July 2020

Abstract
Existing DOD and NASA satellite breakup models are based on a key laboratory test, the 1992 Satellite Orbital debris Characterization Impact Test (SOCIT), which has supported many applications and matched on-orbit events involving older satellite designs reasonably well over the years. To update and improve these models, the NASA Orbital Debris Program Office, in collaboration with the Air Force Space and Missile Systems Center, The Aerospace Corporation, and the University of Florida, conducted a hypervelocity impact test using a high-fidelity mock-up satellite, DebriSat, in controlled and instrumented laboratory conditions. DebriSat is representative of present-day LEO satellites, having been constructed with modern spacecraft materials and techniques. The DebriSat fragment ensemble provided a variety of shapes, bulk densities, and dimensions. Fragments down to 2 mm in size are being characterized by their physical and derived properties. A subset of fragments will be analyzed further in laboratory radar and optical facilities to update the existing radar-based NASA Size Estimation Model (SEM) and develop a comparable optical-based SEM. Thoroughly understanding size estimates from ground-based optical and radar sensors is one of the key parameters used in assessing the environment and the risks that debris present to operational spacecraft. The data will inform updates to the current NASA Standard Satellite Breakup Model (SSBM);, which was formulated using laboratory and ground-based measurements of on-orbit fragmentation events to describe an average breakup for spacecraft and upper stage collisions and explosions. DebriSat will extend the laboratory data ensemble. The DebriSat shape and density categories provide a baseline for non-spherical projectile hypervelocity impact testing for damage assessment. The data from these tests, simulations, and analyses will be used to update the NASA Orbital Debris Engineering Model (ORDEM) with more realistic simulations of catastrophic fragmentation events for modern satellites and to assess the risk posed by the orbital debris environment. This paper provides an overview of the project, updates on the characterization process, and the NASA analysis status.
3D Printed Conical Shaped Charge Performance
Authors: Mulligan Phillip , Johnson Catherine , Ho Jason , Lough Cody , Kinzel Edward 
Published: July 2020

Abstract
A Conical Shaped Charge (CSC) is a versatile device utilized in construction, mining, petroleum and defense industries. The geometry and material structure of the metal liner play an integral role in the CSC performance. The performance of CSC liners has been relatively well-characterized for liners manufactured via hydroforming, hydraulic pressing, or turning on a CNC lathe. With advancements in Additive Manufacturing (AM) CSC liners can be 3D printed with metal powders. AM can provide significant design freedom in terms of realizing better properties through introduced hierarchic structuring or anisotropy. However, it is unclear as to how metal liners produced with Selective Laser Melting (SLM), will influence the conical shaped charge’s performance. This paper explores the performance, relative to the penetration of steel plates, of CSCs using 3D printed metal liners benchmarked against machined liners. The metal liners were printed with SLM parameters that were optimized to maximize the print density. The metal liner dimensions (thickness, height, and outer diameter) were designed using the recommended ratios of the liner’s inner diameter presented by Virgil (1988). The 3D printed metal liners are compared to a CNC machined liner, with the same dimensions. The comparison enables the evaluation of how 3D printing a liner influences penetration performance. The results indicate conical shaped charges could utilize 3D printed liners. These results open a wide range of performance design opportunities that cannot be achieved via conventional manufacturing and justify the current increased cost associated with additive manufacturing metal components. Future work will continue to explore how print density, printed material, and advanced geometries modify the conical shaped charge performance.
A Predictive Non-Dimensional Scaling Law for the Plate Perforation of Several Aluminum Alloys by Fragment-Simulating Projectiles
Authors: Chen Weinong , Guo Zherui 
Published: July 2020

Abstract
An equation was previously-presented to predict the ballistic-limit velocity for the perforation of aluminum armor plates by fragment-simulating projectiles (FSP). The ballistic-limit equation was presented in terms of dimensionless parameters so that the geometric and material problem scales are identified. Previously published predictions and data for two different FSP projectile calibers (12.7 mm and 20 mm) and two different strength aluminum alloys show the scaling law to be accurate. In this paper we extend the same concept to several other alloys and show that this scaling law is predictive.
Coils, Codes and Comets: My Attempts to Partially Understand Some Particular Aspects of Hypervelocity Impacts
Authors: Crawford David A. 
Published: July 2020

Abstract
At the time of this writing in 2019, I have been studying hypervelocity impacts for about 34 years. I attended my first Hypervelocity Impact Symposium in 1992. In this paper, I attempt to show what I’ve been up to all this time but also show some of the things I’ve learned along the way. I’ve singled out three topics that stand out in my mind as milestones in my career: the impact of Comet Shoemaker-Levy 9 on Jupiter in 1994, the development of adaptive mesh refinement for the CTH hydrocode in 1998-2001 and my ongoing studies of hypervelocity impact-generated magnetic fields from 1985 to the present day.
Optimised retinopathy of prematurity screening guideline in China based on a 5-year cohort study
Authors: Yang Qian , Zhou Xiaohong , Ni Yingqin , Shan Haidong , Shi Wenjing , Yin Xuelei , Liu Jiangqin , Huang Xin 
Published: July 2020

PurposesTo develop an optimised retinopathy of prematurity (ROP) screening guideline by adjusting the screening schedule and thresholds of gestational age (GA) and birth weight (BW).MethodsA multicentre retrospective cohort study was conducted based on data from four tertiary neonatal intensive care units in Shanghai, China. The medical records of enrolled infants, born from 2012 to 2016 who underwent ROP examinations, were collected and analysed. The incidence and risk factors for ROP were analysed in all infants. Postnatal age (PNA) and postmenstrual age (PMA) of infants, detected to diagnose ROP for the first time, were compared with the present examination schedule. The predictive performance of screening models was evaluated by internally validating sensitivity and specificity.ResultsOf the 5606 eligible infants, ROP was diagnosed in 892 (15.9%) infants; 63 (1.1%) of them received treatment. The mean GA of ROP patients was 29.4±2.4 weeks, and the mean BW was 1260±330 g. Greater prematurity was associated with an older PNA at which ROP developed. The minimum PMA and PNA at which diagnosis of treatable ROP occurred were 32.43 and 3 weeks, respectively. The optimised criteria (GA <32 weeks or BW <1600 g) correctly predicted 98.4% type 1 ROP infants, reducing the infants requiring examinations by 43.2% when internally validated.ConclusionsThe incidence of type 1 ROP and the mean GA and BW of ROP infants have decreased in China. The suggested screening threshold and schedule may be reliably used to guide the modification of ROP screening guideline and decrease medical costs.
Physical distancing interventions and incidence of coronavirus disease 2019: natural experiment in 149 countries
Authors: Islam Nazrul , Sharp Stephen J , Chowell Gerardo , Shabnam Sharmin , Kawachi Ichiro , Lacey Ben , Massaro Joseph M , D’Agostino Ralph B , White Martin 
Published: July 2020

AbstractObjectiveTo evaluate the association between physical distancing interventions and incidence of coronavirus disease 2019 (covid-19) globally.DesignNatural experiment using interrupted time series analysis, with results synthesised using meta-analysis.Setting149 countries or regions, with data on daily reported cases of covid-19 from the European Centre for Disease Prevention and Control and data on the physical distancing policies from the Oxford covid-19 Government Response Tracker.ParticipantsIndividual countries or regions that implemented one of the five physical distancing interventions (closures of schools, workplaces, and public transport, restrictions on mass gatherings and public events, and restrictions on movement (lockdowns)) between 1 January and 30 May 2020.Main outcome measureIncidence rate ratios (IRRs) of covid-19 before and after implementation of physical distancing interventions, estimated using data to 30 May 2020 or 30 days post-intervention, whichever occurred first. IRRs were synthesised across countries using random effects meta-analysis.ResultsOn average, implementation of any physical distancing intervention was associated with an overall reduction in covid-19 incidence of 13% (IRR 0.87, 95% confidence interval 0.85 to 0.89; n=149 countries). Closure of public transport was not associated with any additional reduction in covid-19 incidence when the other four physical distancing interventions were in place (pooled IRR with and without public transport closure was 0.85, 0.82 to 0.88; n=72, and 0.87, 0.84 to 0.91; n=32, respectively). Data from 11 countries also suggested similar overall effectiveness (pooled IRR 0.85, 0.81 to 0.89) when school closures, workplace closures, and restrictions on mass gatherings were in place. In terms of sequence of interventions, earlier implementation of lockdown was associated with a larger reduction in covid-19 incidence (pooled IRR 0.86, 0.84 to 0.89; n=105) compared with a delayed implementation of lockdown after other physical distancing interventions were in place (pooled IRR 0.90, 0.87 to 0.94; n=41).ConclusionsPhysical distancing interventions were associated with reductions in the incidence of covid-19 globally. No evidence was found of an additional effect of public transport closure when the other four physical distancing measures were in place. Earlier implementation of lockdown was associated with a larger reduction in the incidence of covid-19. These findings might support policy decisions as countries prepare to impose or lift physical distancing measures in current or future epidemic waves.
30-minute postload plasma glucose levels during an oral glucose tolerance test predict the risk of future type 2 diabetes: the Hisayama Study
Authors: Hirakawa Yoichiro , Hata Jun , Yoshinari Masahito , Higashioka Mayu , Yoshida Daigo , Shibata Mao , Honda Takanori , Sakata Satoko , Kato Hiroyuki , Teramoto Takanori , Maki Hideki , Nishimoto Shozo , Kitazono Takanari , Ninomiya Toshiharu 
Published: July 2020

IntroductionTo investigate the associations of 30 min postload plasma glucose (30 mPG) levels during an oral glucose tolerance test (OGTT) with the risk of future diabetes in a general Japanese population.Research design and methodsA total of 2957 Japanese community-dwelling residents without diabetes, aged 40–79 years, participated in the examinations in 2007 and 2008 (participation rate, 77.1%). Among them, 2162 subjects who received 75 g OGTT in a fasting state with measurements of plasma glucose level at 0, 30, and 120 min were followed up for 7 years (2007–2014). Cox’s proportional hazards model was used to estimate HRs and their 95% CIs of each index for the development of type 2 diabetes using continuous variables and quartiles with adjustment for traditional risk factors. The influence of 30 mPG on the predictive ability was estimated with Harrell’s C-statistics, integrated discrimination improvement (IDI), and the continuous net reclassification index (cNRI).ResultsDuring follow-up, 275 subjects experienced type 2 diabetes. Elevated 30 mPG levels were significantly associated with increased risk of developing diabetes (p<0.01 for trend): the multivariable-adjusted HR was 8.41 (95% CI 4.97 to 14.24) for the highest versus the lowest quartile, and 2.26 (2.04 to 2.52) per 1 SD increase. This association was attenuated but remained significant after further adjustment for fasting and 2-hour postload plasma glucose levels. Incorporation of 30 mPG into the model including traditional risk factors with fasting and 2-hour postload plasma glucose levels for diabetes improved the predictive ability of type 2 diabetes (improvement in Harrell’s C-statistics values: from 0.828 to 0.839, p<0.01; IDI: 0.016, p<0.01; cNRI: 0.103, p=0.37).ConclusionsElevated 30 mPG levels were associated with increased risk of diabetes, and inclusion of 30 mPG levels significantly improved the predictive ability for future diabetes, suggesting that 30 mPG may be useful for identifying high-risk populations for type 2 diabetes.
Impact of Multiple Social Determinants of Health on Incident Stroke
Authors: Reshetnyak Evgeniya , Ntamatungiro Mariella , Pinheiro Laura C. , Howard Virginia J. , Carson April P. , Martin Kimberly D. , Safford Monika M. 
Published: July 2020

Background and Purpose:
Social determinants of health (SDOH) have been previously associated with incident stroke. Although SDOH often cluster within individuals, few studies have examined associations between incident stroke and multiple SDOH within the same individual. The objective was to determine the individual and cumulative effects of SDOH on incident stroke.

Methods:
This study included 27 813 participants from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study, a national, representative, prospective cohort of black and white adults aged ≥45 years. SDOH was the primary exposure. The main outcome was expert adjudicated incident stroke. Cox proportional hazards models examined associations between incident stroke and SDOH, individually and as a count of SDOH, adjusting for potential confounders.

Results:

The mean age was 64.7 years (SD 9.4) at baseline; 55.4% were women and 40.4% were blacks. Over a median follow-up of 9.5 years (IQR, 6.0–11.5), we observed 1470 incident stroke events. Of 10 candidate SDOH, 7 were associated with stroke (
P
<0.10): race, education, income, zip code poverty, health insurance, social isolation, and residence in one of the 10 lowest ranked states for public health infrastructure. A significant age interaction resulted in stratification at 75 years. In fully adjusted models, among individuals <75 years, risk of stroke rose as the number of SDOH increased (hazard ratio for one SDOH, 1.26 [95% CI, 1.02–1.55]; 2 SDOH hazard ratio, 1.38 [95% CI, 1.12–1.71]; and ≥3 SDOH hazard ratio, 1.51 [95% CI, 1.21–1.89]) compared with those without any SDOH. Among those ≥75 years, none of the observed effects reached statistical significance.

Conclusions:
Incremental increases in the number of SDOH were independently associated with higher incident stroke risk in adults aged <75 years, with no statistically significant effects observed in individuals ≥75 years. Targeting individuals with multiple SDOH may help reduce risk of stroke among vulnerable populations.
Depicting a Prayer before the Battle: On the Reader’s Marginalia Drawing in the Old Rus’ Manuscript from the British Library
Authors: Veselov Fedor 
Published: July 2020

Abstract
In the note, the author focuses on the additional drawing made by an unknown reader on the miniature of the Old Rus’ illuminated manuscript of the Tale of the Route of Mamai. The drawing depicts the image of the Mandylion over one of the key scenes of the Tale: Dmitry Donskoy receiving the blessing and prosphoron from St Sergius of Radonezh. The author examines both, the text, that is illustrated, which cites the monastic rite of Panagia, and the symbolism of the image of the Holy Saviour Not Made by Hands, to conclude whether the addition was accidental or not.
The Qurʾān Encrypted
Authors: D’Ottone Rambach Arianna 
Published: July 2020

Abstract
This article (re-)considers a unique Qurʾān manuscript (MS London, SOAS, 12217) in ciphered characters (Ar. al-taʿmiya), reminiscent of the ring letters of the Graeco-Egyptian tradition (Brillenbuchstaben). The case of this Qurʾān manuscript offers an opportunity to decode (Ar. istikhrāj al-muʿammà) a cryptographed text, to date and localize a very special Quranic codex, and to investigate the history of the collections it passed through, as well as the religious and cultural context of its production. Lastly, it examines the relations between Islam and magic—with which cryptography is often associated.
Seasonal Forecast of Early Summer Rainfall at Stations in South China Using a Statistical Downscaling Model
Authors: Lu Zheng , Guo Yan , Zhu Jiangshan , Kang Ning 
Published: July 2020

AbstractCurrent dynamic models are not able to provide reliable seasonal forecasts of regional/local rainfall. This study aims to improve the seasonal forecast of early summer rainfall at stations in South China through statistical downscaling. A statistical downscaling model was built with the canonical correlation analysis method using 850-hPa zonal wind and relative humidity from the ERA-Interim reanalysis data. An anomalous southwesterly wind that carries sufficient water vapor encounters an anomalous northeasterly wind from the Yangtze River, resulting in a wet anomaly over all of South China. This model provided good agreement with observations in both the training and independent test periods. In an independent test, the average temporal correlation coefficient (TCC) at 14 stations was 0.52, and the average root-mean-square error was 21%. Then, the statistical downscaling model was applied to the Climate Forecast System, version 2 (CFSv2), outputs to produce seasonal forecasts of rainfall for 1982–2018. A statistical downscaling model improved CFSv2 forecasts of station rainfall in South China with the average TCC increasing from 0.14 to 0.31. Forecasts of South China regionally averaged rainfall were also improved with the TCC increasing from 0.11 to 0.53. The dependence of forecast skill for regional average rainfall on ENSO events was examined. Forecast error was reduced, but not statistically significant, when it followed an El Niño event in both CFSv2 and the downscaling model. While when it followed an EP-type El Niño, the significantly reduced forecast error (at the 0.1 level) could be seen in the downscaling model and CFSv2.