bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proposed Qualification Test Procedure to Identify Prestressed Concrete Ties That May Be Susceptible to End-Splitting Cracks
Authors: Savic Adrijana , Beck B. Terry , Peterman Robert J. 
Published: June 2021

Abstract
Prestressed concrete ties could develop end-splitting cracks along tendons due to lateral bursting stresses. The lateral bursting stresses can form due to Hoyer effect (change in diameter of the prestressing tendons due to Poisson’s ratio, the jacking force in the tendons, geometrical features, and indent characteristics of the prestressing tendons. End-splitting cracks can occur immediately after de-tensioning procedure in some cases, but they also can be developed during the first weeks after de-tensioning procedure due to sustained lateral stresses exerted by the prestressing tendons. The ability of concrete to resist these bursting stresses without cracking is primarily the function of the thickness of concrete cover, the type of concrete mixture used and the maximum compressive strength of the concrete. The test purpose was to identify tie designs that may be susceptible to end-splitting cracks. The Qualification test will be great tool to identify tie designs that have ability to form end-splitting cracks. The System Qualification Test involves six pre-tensioned concrete prisms with the same prestressing tendons and concrete mixture that is used in the concrete ties, except that the edge distance for the prisms is reduced by approximately 25 percent. If this reduction in edge distance results in longitudinal splitting cracks along the prestressing tendons, then the system (tie design and material selection) may be susceptible to concrete end-splitting cracks. In this case, changes to the design and/or material selection should be made prior to mass production of ties.
Multiscale Simulation-Based Mixed Train Derailment Analysis: A Case Study
Authors: Wang Yi , Nich Steven , Mulligan Kyle , Oldknow Kevin , Wang G. Gary 
Published: June 2021

Abstract
The makeup of mixed-manifest freight trains is often determined through rigid operating rules designed based on steady-state in-train forces under nominal vehicle and track conditions. Despite compliance with these rules, excessive forces experienced during exceptional situations still hold significant potential to result in derailments. This paper presents a case study involving a mixed train derailment in a sharp curve following an undesired brake release. The operating conditions and sequence of events are modelled using a novel multiscale simulation approach to combine industry-established longitudinal and multi-body dynamics simulation packages. The root cause of the derailment in this case study is assessed, along with the effectiveness of subsequent rule changes in mitigating the corresponding risk. The case study and results are further discussed in the broader context of a research initiative to utilize near real-time data collection from wayside and vehicle-mounted measurement systems, together with robust multiscale simulation approaches, to improve the area of mixed train marshalling.
New Locomotives & Technologies: Reducing Operating & Market Failures Through Aggressive Use of Reliability Growth Testing (RGT)
Authors: Iden Michael E. , Kennedy Thomas 
Published: June 2021

Abstract
Because of increasing interest and ongoing demand for reducing locomotive emissions, railroads and locomotive manufacturers may become involved in new propulsion technologies (such as fuel cells and new battery technologies) as eventual replacements for diesel-electric locomotives. Railroads and locomotive manufacturers (in the U.S. and elsewhere) have unfortunately had mixed results for decades in successfully introducing new locomotive models, power plants and new locomotive technologies with episodes of unacceptable levels of road failures, and post-delivery underperformance in terms of reliability, maintainability and operability. Occasionally, accumulative failures and performance shortfalls have resulted in excessive maintenance expenses and even premature retirement and scrappage of relatively “young” locomotive assets. A tool that should be used before new designs of locomotives (and locomotives with significant amounts of new technology) enter commercial production is Reliability Growth Testing (RGT). RGT requires and involves having a statistically significant number of “preproduction” locomotives (not experimental prototypes) operated and maintained under “real railroad” conditions (not exclusively at dedicated test facilities). RGT is always preceded by engineering analyses and design, production of preproduction components, test bench and test cell validation, etc, and is always followed by necessary redesign of components experiencing significant failures so that when commercial production is started the products have a high probability of meeting railroad customer expectations and requirements. Failure to do adequate RGT can produce a high risk of post-delivery failure for locomotive (and component) manufacturers, railroads and financial entities that mortgage new locomotives. RGT units can then, in fact, be reconfigured at the conclusion of RGT activity and delivered to a railroad as being “production compliant” units. Once any new locomotive has been “sold to the customer” it becomes a customer asset. Having to modify (“fix”) a marginal or “bad” locomotive design after a railroad customer has accepted it (sometimes multiple times!) is an unacceptable outcome in a locomotive’s early life.
Multimodal Mobility Framework: Towards Seamless Mobility Experience
Authors: Vennelakanti Ravigopal , Sankaranarayanasamy Malarvizhi , Saeedi Ramyar , Vishwakarma Rahul , Singh Prasun , Sun Jian , Akiyama Yushi , Adachi Hisao 
Published: June 2021

Abstract
Mobility is no longer just a necessity for travelers, but choices among several possible routes and transportation modes. Urban passenger rail transport plays an essential role because it is affordable, convenient, safe, and fast. On the other hand, rail lines are limited to high passenger density corridors. Inevitably, rail has to be placed together with different transport modes, forming a multimodal network. However, to enable this integration with other modes of transport, numerous practical problems remain, such as making a smooth transition from the existing siloed, mode specific operational structure towards an interconnected system of transportation modes and business models for a seamless connected journey. The current isolated operational structure lacks a single truth and accurate visibility, which further discourages participation from augmenting transportation modes and leads to the extended reaction time for new technology integration.
This research article introduces a Multimodal Mobility (MMM) solution framework that provides a functional interface to integrate and synchronize the railroad operations with other public transit networks (including train-bus-rapid transits) and micro-mobility services. The known approach to addressing the users’ seamless mobility experience entails a centralized, prearranged, a priori knowledge and mechanism for operating intermodal transport systems. In contrast, the method defined in this paper focuses on a market-driven demand-responsive system that allows for dis-intermediation in a network of peer-level transportation modes operations. The framework facilitates blockchain-based decentralized and multi-organizational engagement.
The focus here is the role of railroad in the multimodal ecosystem and its performance advancements in this integrated solutions framework. Leveraging a combination of graph analytics and machine learning algorithms, we provide methods to address challenges in encoding spatial and temporal dependencies of multimodal transit networks and handle complex optimization problems such as mixed time window and volume variation for resource allocation and transit operational analytics. This enables operation of different transit modes with varied resolution and flexibility for operational parameters like time, capacity, ridership, revenue management, etc. The analytics enable solutions for recommendations on synchronizing and integrating operations of transportation systems. Further, the network’s decentralization and modular handling enable market-driven co-optimization of operational resources across various transportation modes to ensure seamless transit experience for users.
Updated Fuel Tank Puncture Survey: 1995-2020
Authors: Jacobsen Karina 
Published: June 2021

Abstract
The Federal Railroad Administration’s Office of Research, Development and Technology has been conducting research into passenger fuel tank crashworthiness. The occurrence of a fuel tank puncture during passenger rail collisions and derailments increases the potential of serious injury and fatality for crew and passengers due to the possibility of fire. The purpose of the FRA research is to help support regulatory and standard development with technical data. In the last decade, the research has focused on understanding how fuel tanks are punctured during an impact and how various tank designs respond to common types of loading in collisions, derailments and general operation. Throughout the research, surveys have been conducted to determine the most likely scenarios that are causing fuel tank punctures. A previous FRA survey found that fuel tank punctures occur under two types of loading conditions: a blunt impact or a raking impact. A limited number of accident/incidents were evaluated in this survey. These incidents showed that fuel tanks are punctured on any side that is not protected or shielded.
The purpose of this paper is to report on a recently conducted fuel tank puncture survey updated to include the last decade. This paper identifies and describes accidents and incidents that led to breached fuel tanks in freight and passenger trains traveling on the general railroad system in the U.S. between 2008 and 2020. The results include data from the FRA’s Railroad Accident/Incident Reporting System (RAIRS), queried from 1995 to 2020. This data include the number of recorded accidents/incidents and other trends like fuel spillage, operating authority and cause of accident/incident. RAIRS data showed accidents/incidents with fuel tank puncture ranging from 10 to 55 accidents/incidents per year. Additionally, more detailed results are shared from field investigations recently conducted by the FRA or Volpe Center. These more detailed investigations provide additional insight into the types of loading that may lead to a fuel tank puncture. This survey supplements the RAIRS data with more detailed information from field investigations. The paper finally discusses the conditions that lead to fire and the associated hazards.
Child health and the implementation of Community and District-management Empowerment for Scale-up (CODES) in Uganda: a randomised controlled trial
Authors: Waiswa Peter , Mpanga Flavia , Bagenda Danstan , Kananura Rornald Muhumuza , O’Connell Thomas , Henriksson Dorcus Kiwanuka , Diaz Theresa , Ayebare Florence , Katahoire Anne Ruhweza , Ssegujja Eric , Mbonye Anthony , Peterson Stefan Swartling 
Published: June 2021

IntroductionUganda’s district-level administrative units buttress the public healthcare system. In many districts, however, local capacity is incommensurate with that required to plan and implement quality health interventions. This study investigates how a district management strategy informed by local data and community dialogue influences health services.MethodsA 3-year randomised controlled trial (RCT) comprised of 16 Ugandan districts tested a management approach, Community and District-management Empowerment for Scale-up (CODES). Eight districts were randomly selected for each of the intervention and comparison areas. The approach relies on a customised set of data-driven diagnostic tools to identify and resolve health system bottlenecks. Using a difference-in-differences approach, the authors performed an intention-to-treat analysis of protective, preventive and curative practices for malaria, pneumonia and diarrhoea among children aged 5 and younger.ResultsIntervention districts reported significant net increases in the treatment of malaria (+23%), pneumonia (+19%) and diarrhoea (+13%) and improved stool disposal (+10%). Coverage rates for immunisation and vitamin A consumption saw similar improvements. By engaging communities and district managers in a common quest to solve local bottlenecks, CODES fostered demand for health services. However, limited fiscal space-constrained district managers’ ability to implement solutions identified through CODES.ConclusionData-driven district management interventions can positively impact child health outcomes, with clinically significant improvements in the treatment of malaria, pneumonia and diarrhoea as well as stool disposal. The findings recommend the model’s suitability for health systems strengthening in Uganda and other decentralised contexts.Trial registration numberISRCTN15705788.
Low but not high exercise systolic blood pressure is associated with long-term all-cause mortality
Authors: Hedman Kristofer , Kaminsky Leonard A , Sabbahi Ahmad , Arena Ross , Myers Jonathan 
Published: June 2021

ObjectivesThe risks associated with achieving a high peak systolic blood pressure (SBP) during clinical exercise testing remain controversial, although this issue has not been evaluated in relation to predicted SBP standards. This cohort study aimed to evaluate the long-term risk of all-cause mortality in males in relation to reference values of peak SBP and the increase in SBP during exercise from the Fitness Registry and the Importance of Exercise: A National Database (FRIEND).MethodsWe followed 7164 males (mean age: 58.2±10.6 years) over 95 998 person-years of follow-up (mean 13.4±5.4 years), who performed a maximal treadmill exercise test at baseline. SBP was measured at rest and at peak exercise. Risk of all-cause mortality over 20 years (Cox regression) was determined in relation to reference percentiles of peak SBP and increase in SBP with exercise: <10th (low), 10th–90th, >90th (high) percentiles.ResultsA high peak or a large increase in SBP with exercise was not associated with all-cause mortality. Subjects with a low peak SBP had a 20% higher unadjusted risk for all-cause death compared with those with a normal value (1.20 (1.11–1.31)), and a statistically non-significant 7% higher risk after adjustment for all baseline risk factors (1.07 (0.97–1.18)). The corresponding unadjusted and adjusted risks associated with a low increase in SBP were 1.24 (1.15–1.35) and 1.11 (1.02–1.21), respectively.ConclusionsA low—but not high—peak SBP is associated with increased unadjusted risk of all-cause mortality. The FRIEND percentiles of exercise SBP can aid clinicians in individualising risk assessment.
Systematic literature search, review and dissemination methodology for the COVID-19 pandemic
Authors: Reynard Charles , Darbyshire Daniel , Prager Gabrielle , Jafar Anisa Jabeen Nasir , Naguib Mina , Oliver Govind , van den Berg Patricia , Body Richard , Ambroziak Harriet , Carley Simon 
Published: June 2021

Purpose of the studySARS-CoV-2 has caused healthcare systems globally to reorganise. A pandemic paradox emerged; while clinicians were desperate for information on a new disease, they had less time to find and evaluate the vast volume of publications at times of significant strain on healthcare systems.A multidisciplinary team undertook a weekly literature search capturing all COVID-19 publications. We also monitored free open access medical education (FOAMed) sources for emerging themes. Title and abstract screening pooled the most relevant papers for emergency medicine. Three summary types were created, a ‘Top 5 Flash Update’, a journal club and a rapid response to emerging FOAMed themes. From these summaries, three modes of dissemination were used: short written summaries, blogs and podcasts. These were amplified through social media.Study designA retrospective review was conducted assessing the impact of this knowledge dissemination strategy for the period of March to September 2020.ResultsIn total, 64 687 papers were identified and screened. Of the papers included in the ‘Top 5’, 28.3% were on epidemiology, 23.6% treatment, 16.7% diagnostics, 12% prognosis, 8.7% pathophysiology with the remaining 10.7% consisting of PPE, public health, well-being and ‘other’. We published 37 blogs, 17 podcasts and 18 Top 5 Flash Updates. The blogs were read 138 343 times, the Top 5 Flash Updates 68 610 times and the podcasts had 72 501 listens.ConclusionA combination of traditional academic and novel social media approaches can address the pandemic paradox clinicians are facing.
Follicular helper-T cells restore CD8+-dependent antitumor immunity and anti-PD-L1/PD-1 efficacy
Authors: Niogret Julie , Berger Hélène , Rebe Cédric , Mary Romain , Ballot Elise , Truntzer Caroline , Thibaudin Marion , Derangère Valentin , Hibos Christophe , Hampe Léa , Rageot David , Accogli Théo , Joubert Philippe , Routy Bertrand , Harker James , Vegran Frederique , Ghiringhelli Francois , Chalmin Fanny 
Published: June 2021

BackgroundT follicular helper cells (Tfh) are essential to shape B cell response during germinal center formation. Tfh accumulation has been reported in various human cancers, with positive or negative prognostic roles. However, the mechanisms explaining the accumulation of Tfh and their role in cancer remain obscure.MethodsIn vitro differentiated and mouse cell sorted Tfh phenotype was evaluated by flow cytometry and quantitative PCR (qPCR). Antitumor effect of Tfh was evaluated by adoptive transfer in different tumor-bearing mice models. The involvement of immune cells, cytokines and chemokines was evaluated, using depleting antibodies. Chemokines and cytokines expression and production were evaluated by qPCR and ELISA. In human, the impact of immune cells and chemokines on survival was evaluated by analyzing transcriptomic data from public databases and from our own patient cohorts.ResultsIn this study, we show that Tfh exert an antitumor immune effect in a CD8+-dependent manner. Tfh produce interleukin-21, which sustains proliferation, viability, cytokine production and cytotoxic functions of exhausted T cells. The presence of Tfh is required for efficacy of antiprogrammed cell death ligand-1 therapy. Tfh accumulate in the tumor bed and draining lymph nodes in different mouse cancer models. This recruitment is due to the capacity of transforming growth factor β to drive Chemokine (C-X-C motif) Ligand 13 expression, a chemoattractant of Tfh, by intratumor CD8+T cells. Accumulation of Tfh and exhausted CD8+T cells predicts cancer outcome in various cancer types. In patients treated with anti-programmed cell death-1 mAb, accumulation of Tfh and CD8+at the tumor site is associated with outcome.ConclusionThis study provides evidence that CD8+/Tfh crosstalk is important in shaping antitumor immune response generated by immunotherapy.
Massless fermions in planar Bianchi-type-I universes: exact and approximate solutions
Authors: Wollensak Matthias 
Published: June 2021

AbstractBased upon the exact formal solutions of the Weyl–Dirac-equation in anisotropic planar Bianchi-type-I background spacetimes with power law scale factors, one can introduce suitable equivalence classes of the solutions of these models. The associated background spacetimes are characterized by two parameters. It is shown that the exact solutions of all models of a given equivalence class can be generated with the help of a special transformation of these two parameters, provided one knows a single exact solution of an arbitrary member of this class. The method can also be utilized to derive approximate solutions, i.e. solutions which exhibit the correct behavior at early and at late times as well. This is explicitly demonstrated for the case of the anisotropic Kasner background with axial symmetry.
Gravity resonance spectroscopy and dark energy symmetron fields
Authors: Jenke Tobias , Bosina Joachim , Micko Jakob , Pitschmann Mario , Sedmik René , Abele Hartmut 
Published: June 2021

AbstractSpectroscopic methods allow to measure energy differences with unrivaled precision. In the case of gravity resonance spectroscopy, energy differences of different gravitational states are measured without recourse to the electromagnetic interaction. This provides a very pure and background-free look at gravitation and topics related to the central problem of dark energy and dark matter at short distances. In this article, we analyse the effect of dark energy scalar symmetron fields, a leading candidate for a screened dark energy field, and place limits in a large volume of parameter space.
The Israel-PLO Mutual Recognition Agreement
Authors: Singer Joel 
Published: June 2021

Abstract
From the perspective of a practitioner who was deeply engaged in the negotiations, this article describes how the Israeli-Palestinian Mutual Recognition Agreement was conceived and negotiated. It explains the process of convincing Israeli and Palestinian leaders to accept mutual recognition, overcoming their initial objections. While not nearly as publicized as the 1993 Declaration of Principles agreed at Oslo, this Agreement became the bedrock for all the Oslo Accords, and set the stage for subsequent negotiations.
Puberty challenges of female adolescents with visual impairment
Authors: Aghaee-Chaghooshi Shirin , khodabakhshi-koolaee Anahita , Falsafinejad Mohammad Reza 
Published: June 2021

Physical, psychological, emotional, and social maturity is one of the main challenges occurring during adolescence and is associated with dramatic changes in adolescents. However, these challenges are worsened when the adolescent has a disability in addition to pubertal changes. Accordingly, the present study aimed to explore the puberty challenges of female adolescents with visual impairment.This study is qualitative in terms of its design and an applied study in terms of its objectives and was conducted using a descriptive phenomenology. The research population included all female adolescents with visual impairment who were studying in high school in Tehran in 2020. The participants were blind and visually impaired girls who were selected from the Narjes educational Complex for Blind Girls using purposive sampling. The data were collected through semi-structured interviews and were saturated after interviewing 15 participants. All interviews were recorded, transcribed, and analyzed. The collected data were analyzed using Colaizzi’s seven-step method of data analysis. The challenges faced by the female adolescents with visual impairment were categorized into four main themes including “worrying emotions experienced during puberty,” “development of emotional and love needs,” “redefining social relationships with family and others,” and “lack of information resources on puberty.” This study showed that the lack of information resources, awareness about puberty for female adolescents with visual impairment, the way others treat the puberty of girls, and adolescents’ own reaction to the phenomenon of puberty affect their quality of life in this period. Therefore, paying attention to the experience of female adolescents with visual impairment about the phenomenon of puberty provides a true picture of the feelings, needs, and challenges for visually impaired female adolescents during puberty, their families, school health educators, health professionals, and school counselors.