bluuebunny/crossref_metadata_2025 huggingface dataset:
Dermal nerve fibre and mast cell density, and proximity of mast cells to nerve fibres in the skin of patients with complex regional pain syndrome
Authors: Morellini Natalie , Finch Philip M. , Goebel Andreas , Drummond Peter D.
Published: June 2018

An interaction between cutaneous nerves and mast cells may contribute to pain in complex regional pain syndrome (CRPS). To explore this, we investigated the density of dermal nerve fibres, and the density and proximity of mast cells to nerve fibres, in skin biopsies obtained from the affected and unaffected limbs of 57 patients with CRPS and 28 site-matched healthy controls. The percentage of the dermis stained by the pan-neuronal marker protein gene-product 9.5 was lower in the affected limb of patients than in controls (0.12 ± 0.01% vs 0.22 ± 0.04%, P < 0.05), indicating a reduction in dermal nerve fibre density. This parameter did not correlate with CRPS duration. However, it was lower in the affected than unaffected limb of patients with warm CRPS. Dermal mast cell numbers were similar in patients and controls, but the percentage of mast cells less than 5 µm from nerve fibres was significantly lower in the affected and unaffected limbs of patients than in controls (16.8 ± 1.7%, 16.5 ± 1.7%, and 31.4 ± 2.3% respectively, P < 0.05). We confirm previous findings of a mild neuropathy in CRPS. Our findings suggest that this either develops very early after injury or precedes CRPS onset. Loss of dermal nerve fibres in CRPS might result in loss of chemotactic signals, thus halting mast cell migration toward surviving nerve fibres. Failure of normal nerve fibre–mast cell interactions could contribute to the pathophysiology of CRPS.
Ewing Sarcoma and the History of Similar and Possibly Related Small Round Cell Tumors: From Whence Have We Come and Where are We Going?
Authors: Kilpatrick Scott E. , Reith John D. , Rubin Brian
Published: June 2018

The diagnosis of small round cell tumors always has been extremely difficult, and our current classification systems continue to evolve. Since its initial discovery by Dr James Ewing, the historical context of what is acceptably included under the designation “Ewing sarcoma” has changed. Although Ewing sarcoma and primitive neuroectodermal tumor were both initially described in the early 20th century, these tumors were considered likely distinct entities until the end of that same century, almost 75 years later. With modern immunohistochemistry and more recent advances in molecular techniques, the understanding of Ewing sarcoma and Ewing-like tumors has improved dramatically but also raises new questions and challenges. We now know that this category of tumors is remarkably more heterogenous than initially thought, especially in regards to its cytogenetics and molecular properties, and some of these differences likely have prognostic relevance. Whether we are now expanding the spectrum of Ewing sarcoma or simply recognizing new entities is controversial. Therapeutic approaches to address these new categories and/or entities need further focus and attention. Herein, we provide a comprehensive historical perspective on Ewing sarcoma, Ewing-like tumors (CIC and BCOR-rearranged sarcomas), and related and/or similar small round cell tumors, often included in the differential diagnosis, including mesenchymal chondrosarcoma, desmoplastic small round cell tumor, and small cell osteosarcoma. We also seek to provide updates and insights into the evolving classification and clinical relevance of the Ewing family of tumors.
Evaluating the Accuracy of Using at Rest Images to Determine the Height of Velopharyngeal Closure
Authors: Mason Kazlin N. , Hauhuth Kelly , Perry Jamie L. , Riski John E.
Published: June 2018

Prior to performing secondary surgeries, lateral cephalograms have been used during phonation to evaluate the point of attempted velopharyngeal contact along the posterior pharyngeal wall relative to the palatal plane and the first cervical vertebra. The ability to quantify the height of velopharyngeal closure is an important aspect of planning corrective surgeries for velopharyngeal dysfunction. However, issues with patient compliance during the imaging process can present difficulties for obtaining adequate preoperative imaging data. The purpose of this study was to assess if the height of velopharyngeal closure can be accurately estimated and quantified from at rest images. Results demonstrate that the height of velopharyngeal closure above C1 can be accurately quantified using at rest images in children with cleft palate. No statistically significant difference was found between the measures obtained at rest or during sustained phonation images (P = 0.573). Thus, quantitative measures from at rest images can aid in the preoperative planning process by providing surgeons with a numeric distance for tissue insertion along the posterior pharyngeal wall above C1. This distance is correlated to the height of velopharyngeal closure and successfully placing tissue at this height is likely tied to improved postoperative speech outcomes.
How Public Transport affected the Propagation of Zika and Microcephaly within Rio de Janeiro early in 2015
Authors: Armstrong M. , Coelho F.C. , Bastos L. , Saraceni V. , Lemos C. , Silva M. , Santana L. , Crespo J , Watanabe M.
Published: June 2018

From mid-2015 to the end of January 2016, 47 cases of microcephaly were observed in the city of Rio de Janeiro, that were not due to other viral infections (syphilis, toxoplasmosis, herpes & cytomegalovirus). These children were conceived from Dec 2014 to April 2015, far too early to be explained by the officially recorded cases from October 2015 onward. Zika must have been rampant in the city from late 2014 onward. In the first half of the paper we study how the geographic spread of microcephaly cases evolved from mid-2015 to January 2016 (and hence Zika 6-9 months earlier). Cases were not evenly spread in proportion to the number of births; they were preferentially located in the northern suburbs apparently following the public transport routes, with virtually no cases in favelas and none in the southern suburbs (Zona Sul). One key difference between the transport systems in the northern and southern suburbs is that the metro & rail system in the north is above ground in the north whereas in the southern part the metro is underground with air-conditioning in carriages and forced ventilation on the platforms. The train system does not extend to Zona Sul.

In the second half of the paper we postulate that the air-conditioning and ventilation prevent mosquitos from biting people who are waiting on platforms in Zona Sul. Agent-based simulations are used to test this hypothesis. After confirming this, we postulate that providing air-conditioning and/or forced ventilation on the rail-metro transport hub in the city center (Centro) would significantly delay the propagation of arboviruses in the city, possibly preventing epidemics. One advantage of this proposal is that it does not require the use of insecticides.
Run or die in the evolution of new microRNAs - Testing the Red Queen hypothesis on de novo new genes
Authors: Zhao Yixin , Lu Guang-An , Yang Hao , Lin Pei , Liufu Zhongqi , Tang Tian , Xu Jin
Published: June 2018

The Red Queen hypothesis depicts evolution as the continual struggle to adapt. According to this hypothesis, new genes, especially those originating from non-genic sequences (i.e., de novo genes), are eliminated unless they evolve continually in adaptation to a changing environment. Here, we analyze two Drosophila de novo miRNAs that are expressed in a testis-specific manner with very high rates of evolution in their DNA sequence. We knocked out these miRNAs in two sibling species and investigated their contributions to different fitness components. We observed that the fitness contributions of miR-975 in D. simulans seem positive, in contrast to its neutral contributions in D. melanogaster, while miR-983 appears to have negative contributions in both species, as the fitness of the knockout mutant increases. As predicted by the Red Queen hypothesis, the fitness difference of these de novo miRNAs indicates their different fates.
Distinct Microbes, Metabolites, and Ecologies Define the Microbiome in Deficient and Proficient Mismatch Repair Colorectal Cancers
Authors: Hale Vanessa L. , Jeraldo Patricio , Chen Jun , Mundy Michael , Yao Janet , Priya Sambhawa , Keeney Gary , Lyke Kelly , Ridlon Jason , White Bryan A. , French Amy J. , Thibodeau Stephen N. , Diener Christian , Resendis-Antonio Osbaldo , Gransee Jaime , Dutta Tumpa , Petterson Xuan-Mai , Blekhman Ran , Boardman Lisa , Larson David , Nelson Heidi , Chia Nicholas
Published: June 2018

Background

The link between colorectal cancer (CRC) and the gut microbiome has been established, but the specific microbial species and their role in carcinogenesis remain controversial. Our understanding would be enhanced by better accounting for tumor subtype, microbial community interactions, metabolism, and ecology.

Methods

We collected paired colon tumor and normal–adjacent tissue and mucosa samples from 83 individuals who underwent partial or total colectomies for CRC. Mismatch repair (MMR) status was determined in each tumor sample and classified as either deficient MMR (dMMR) or proficient MMR (pMMR) tumor subtypes. Samples underwent 16S rRNA gene sequencing and a subset of samples from 50 individuals were submitted for targeted metabolomic analysis to quantify amino acids and short-chain fatty acids. A PERMANOVA was used to identify the biological variables that explained variance within the microbial communities. dMMR and pMMR microbial communities were then analyzed separately using a generalized linear mixed effects model that accounted for MMR status, sample location, intra–subject sample correlation, and read depth. Genome–scale metabolic models were then used to generate microbial interaction networks for dMMR and pMMR microbial communities. We assessed global network properties as well as the metabolic influence of each microbe within the dMMR and pMMR networks.

Results

We demonstrate distinct roles for microbes in dMMR and pMMR CRC. Sulfidogenic Fusobacterium nucleatum and hydrogen sulfide production were significantly enriched in dMMR CRC, but not pMMR CRC. We also surveyed the butyrate–producing microbial species, but did not find a significant difference in predicted or actual butyrate production between dMMR and pMMR microbial communities. Finally, we observed that dMMR microbial communities were predicted to be less stable than pMMR microbial communities. Community stability may play an important role in CRC development, progression, or immune activation within the respective MMR subtypes.

Conclusions

Integrating tumor biology and microbial ecology highlighted distinct microbial, metabolic, and ecological properties unique to dMMR and pMMR CRC. This approach could critically improve our ability to define, predict, prevent, and treat colorectal cancers.
NMDA spikes mediate amplification of odor pathway information in the piriform cortex
Authors: Kumar Amit , Schiff Oded , Barkai Edi , Mel Bartlett W. , Poleg-Polsky Alon , Schiller Jackie
Published: June 2018

The piriform cortex (PCx) receives direct input from the olfactory bulb (OB) and is the brain’s main station for odor recognition and memory. The transformation of the odor code from OB to PCx is profound: mitral and tufted cells in olfactory glomeruli respond to individual odorant molecules, whereas pyramidal neurons (PNs) in the PCx responds to multiple, apparently random combinations of activated glomeruli. How these “discontinuous” receptive fields are formed from OB inputs remains unknown. Counter to the prevailing view that olfactory PNs sum their inputs passively, we show for the first time that NMDA spikes within individual dendrites can both amplify OB inputs and impose combination selectivity upon them, while their ability to compartmentalize voltage signals allows different dendrites to represent different odorant combinations. Thus, the 2-layer integrative behavior of olfactory PN dendrites provides a parsimonious account for the nonlinear remapping of the odor code from bulb to cortex.
The impact of person-organization fit and leader-member exchange on withdrawal behaviors in Thailand
Authors: Rurkkhum Suthinee
Published: June 2018

Purpose

The purpose of this paper is to examine the impact of person-organization fit and leader-member exchange (LMX) on the withdrawal behaviors of Thai employees.

Design/methodology/approach

Self-report questionnaires were received from 300 employees working in one of the largest Thai public universities. Exploratory factor analysis was conducted, followed by confirmatory factor analysis. Structural equation model was then implemented to test the relationships among all variables.

Findings

The results showed negative relationships between person-organization fit and withdrawal behaviors, between LMX and withdrawal behaviors, and between person-organization fit and LMX and an intention to leave. However, only person-organization fit was statistically significant with withdrawal behaviors and an intention to leave. The progression model of withdrawal behaviors was also supported.

Research limitations/implications

The self-report questionnaires were the limitations of the study.

Practical implications

This study highlighted the importance of withdrawal behaviors and an intention to leave an organization which are costly behaviors. Person-organization fit should be emphasized at the recruitment and selection process, and coherent human resource practices should be used in an organization to possibly lessen these costly behaviors.

Originality/value

This study contributed to the knowledge of withdrawal behaviors, covering both least severe and more extreme behaviors. This study suggested that an organization should pay attention to these least severe withdrawal behaviors among employees, since these can lead to an extreme withdrawal behavior – i.e. an intention to leave an organization.
Is tourism really an escape from everyday life? Everyday leisure activities vs leisure travel activities of expats and emirati nationals living in the UAE
Authors: Slak Valek Natasa , Fotiadis Anestis
Published: June 2018

Purpose

The purpose of this study is to understand the linkage between everyday life activities with its various aspects of leisure and the leisure-related activities undertaken when traveling as a tourist. This comparison is based on information from individuals who take on both the roles of the everyday person and the traveling tourist. Moreover, as the study is based in the UAE, a multi-cultural country, leisure activities between local residents and expatriates living in UAE are contrasted as part of the investigation.

Design/methodology/approach

A newly modified International Social Survey Program about Leisure Time questionnaire was used in this study to define a comprehensive list of leisure activities. This was distributed to a sample of local residents and expats living in the UAE in 2015. Pearson χ2 was used to understand the association between everyday leisure activities and travel leisure activities.

Findings

The results show statistically significant differences in everyday leisure activities between expats and Emirati nationals living in UAE. Moreover, a moderate (V = 0.21; p = 0.25) strength of associations between everyday activities and travel leisure activities was found in the overall sample of all UAE residents.

Research limitations/implications

A non-probability sampling method was used to collect the data, and no general conclusions about the segments or the total population of residents can be made at this point. However, the sample size is sufficient to examine the proposed model and understand the differences between the two resident segments (Emirati nationals vs expats) and to compare the differences in behavior between everyday leisure and tourism-related leisure activities.

Practical implications

These findings are recommended for consideration by tourism authorities, holiday destination managers and trip organizers when targeting UAE residents, both Emirati nationals and expats.

Social implications

As a relation between everyday activities and travel activities was confirmed, the typical tourism motivation assumption that people are traveling to escape the everyday should be reconsidered. In addition, a managerial conclusion is that Emirati nationals and expats should be considered as two distinct groups when devising, preparing and marketing the leisure activities for the market in the UAE.

Originality/value

The problem of separating tourism travel from everyday life, as the common perspective of the time, was to treat tourism simply as a temporary escape from everyday life. This research enters this same area and attempts to fill the academic gap and address this issue which, to our knowledge, no specific studies have investigated or exposed the relationship between common everyday leisure activities and special travel leisure activities.
The use of tabletop exercises in nuclear security education
Authors: Shattan Michael , Seybert Adam , Gilbreath Robert Boone , Dahunsi Stephen , Hall Howard L.
Published: June 2018

Purpose

The purpose of this paper is to explore the role of tabletop exercises (TTXs) in graduate nuclear security education, their effectiveness and their relationship to traditional forms of classroom instruction. The paper highlights both the benefits and challenges of TTX implementation—the former including higher student motivation and material retention, and the latter including motivational shifts toward “winning” and possible student exclusionary behavior.

Design/methodology/approach

Survey results from 49 former students in a US university were collected electronically and combined with anecdotal evidence from student, facilitator and teaching assistant interviews following five iterations of a specifically designed, semester-long, TTX case study. The case study focused on securing a fictional nuclear facility.

Findings

Students found the TTX more memorable and retained more course material when asked to compare the TTX’s effectiveness to long-term course projects in other courses. Their in-class motivations tended to shift from traditional classroom motivations toward “winning,” and “not letting down their classmates.” In some iterations, students also observed classmates becoming more tempted to cheat or otherwise violate academic ethics. Mitigation strategies to prevent such temptations (e.g. removing direct student vs student TTX structures) were found to be effective.

Originality/value

This is the first report on the effective use of a semester-long TTX in a graduate nuclear security classroom. The flexibility of this instructional tool demonstrates its applicability to other classroom subjects including homeland security, emergency management, disease outbreak management and public policy among others.
The economic impact of a rise in US trade protectionism on East Asia
Authors: Cheong Inkyo , Tongzon Jose
Published: June 2018

Purpose

The purpose of this paper is to evaluate the economic impact of a rising US trade protectionism on the economies of China, Japan, South Korea and the ASEAN countries and draw out some policy and strategic implications for the USA and East Asia.

Design/methodology/approach

The authors employ a computable general equilibrium approach supplemented with qualitative analyses based on empirical evidence.

Findings

An increase in US import tariffs would result in economic losses for the USA and the corresponding country or region to which the import tariff increase is applied. An increase in US import tariffs for Chinese goods alone would not have any spillover effects on other East Asian countries. But, an imposition of a border adjustment tax (BAT) for all countries and for all products would actually boost US economic growth. Advanced economies would enjoy GDP increases, but China, Korea and the ASEAN countries would face an economic loss in a longer term period, although they would enjoy some growth in the short term. However, when the BAT only applies to a specific East Asian country, USA would suffer an economic loss, with the exception of a BAT specifically targeted at the ASEAN countries. ASEAN countries would not experience any economic loss under all scenarios except in the case of import tariffs specifically targeted at ASEAN.

Research limitations/implications

From the US perspective, it is beneficial to adopt a BAT for all countries and across the board. Under this arrangement, there would be an economic loss for China, Korea and the ASEAN countries in the longer term. An increase in US trade protectionism would only push the East Asian countries towards deeper economic integration, with serious implications for global pattern of trade and investment.

Originality/value

The existing literature on the likely economic impact of US trade protectionism on East Asia is very scarce and based on surveys and subjective speculations. This study uses a quantitative method based on empirical evidence.
Audit committee characteristics: an empirical investigation of the contribution to intellectual capital efficiency
Authors: Buallay Amina
Published: June 2018

Purpose

In a knowledge economy, it is generally agreed that audit committees play a significant role in supporting the overall firm’s knowledge, particularly enhancing the reporting process. In this respect, this paper aims to examine the effect of audit committee characteristics on intellectual capital efficiency.

Design/methodology/approach

This study examined 59 banks for five years (2011-2015), obtaining 295 observations. The study’s independent variable is audit committee characteristics. The dependent variable is intellectual capital components (Human: human capital efficiency [HCE]; Structural: structural capital efficiency [SCE]; Relational: relational capital efficiency [RCE]; and Physical/Financial: capital employed efficiency [CEE]). In addition, the study used four bank-specific control variables.

Findings

The findings deduced from the empirical results demonstrate that there is a significant positive impact of audit committee characteristics on intellectual capital. Moreover, the relationship between audit committee and intellectual capital components (HCE, SCE, RCE and CEE) also has a significant positive relationship if measured individually.

Originality/value

The study provides insights about the relationship between audit committee characteristics and the improvement in intellectual capital efficiency, which might be used by firms to re-arrange the roles within audit committee, to reassign internal priorities and to escalate position in their environment.
Founding team experience, industry context, and new venture creation
Authors: Li Jun , Dutta Dev K.
Published: June 2018

Purpose

The purpose of this paper is to examine the role of founding team experience (industry and venturing) in new venture creation. This paper posits the following questions: How does founding team experience influence the likelihood of new venture creation, in the nascent stage? How does industry context moderate this relationship? The study aims to fill an important gap in the literature by unpacking the impact of different types of founding team experiences on venture outcome, and by focusing on the influence of founding team in the venture creation process, specifically at the nascent stage.

Design/methodology/approach

The paper utilizes data from the Second Panel Study of Entrepreneurial Dynamics, a longitudinal data set of 1,214 nascent entrepreneurs in the USA. Logistics regression was employed to analyze the effect of founding team experience on new venture creation. Post hoc analysis was conducted to ensure the confidence of the findings.

Findings

The paper provides empirical insights about how founding team experience influences the likelihood of new venture creation in the nascent stage. At the nascent stage, founding team industry experience positively affects new venture creation while founding team venturing experience does not. However, in the high-technology industry environment, the influence of the founding team’s venturing experience on new venture creation is stronger than that in the low-technology industry environment.

Research limitations/implications

Due to the design of the data set, there is a risk of “right-censoring” problem. Also, because the study used archival data on founding teams, the methodology did not allow for uncovering the underlying team processes and dynamics during the venture creation process based on learning from experience. Future studies are encouraged to examine other types of founding team experience and the underlying process-level factors on venture creation.

Practical implications

The paper provides important practical implications for nascent entrepreneurs/entrepreneurial teams on team assembling and composition. In general, a team with higher-level industry experience is critical for venturing success. A team with higher-level venturing experience is more desired in the high-technology industry.

Originality/value

This paper fulfills an important gap in the entrepreneurial team literature by highlighting the complex and nuanced ways in which founding team experience influences the likelihood of venture creation in the nascent stage of the firm, especially after incorporating the additional impact of the industry context.
Understanding the Connections between the EU Global Strategy and Somali Peacebuilding Education Needs and Priorities
Authors: Lewis Alexandra , Winn Neil
Published: June 2018

This paper examines the connections between identity politics and European Union (EU) aid effectiveness in peacebuilding education in Somalia. It engages with a severe educational challenge, which is that a lack of capacity in rigorous educational design and/or implementation across Somali Ministries in the South Central Zone, Somaliland and Puntland has led to the importation of multiple foreign curricula into the country simultaneously that do not address Somali history and contemporary conflict drivers and that frequently clash with local values as well as with each other. We critique this from a ‘new barbarism’ perspective, arguing that Somali voices and educational priorities have not been provided a sufficient space for expression in the EU debate on the global and therefore also the national development agenda.
Measuring the intensity of community programs and policies for preventing childhood obesity in a diverse sample of US communities: the Healthy Communities Study
Authors: Collie‐Akers V. L. , Schultz J. A. , Fawcett S. B. , Landry S. , Obermeier S. , Frongillo E. A. , Forthofer M. , Weinstein N. , Weber S. A. , Logan A. , Arteaga S. S. , Nebeling L. , Au L. E. ,   on behalf of the Healthy Communities Study Team
Published: June 2018

Introduction

Efforts to address the critical public health problem of childhood obesity are occurring across the USA; however, little is known about how to characterize the intensity of these efforts.

Objectives

The purposes of this study are to describe the intensity of community programs and policies (CPPs) to address childhood obesity in 130 US communities and to examine the extent to which observed CPPs targeted multiple behaviours and employed a comprehensive array of strategies.

Methods

To document CPPs occurring over a 10‐year period, key informants were interviewed using a semi‐structured interview protocol. Staff coded CPPs for key characteristics related to intensity, including reach, duration and strategy. Three types of CPP scores were calculated for intensity of CPPs, targeting of CPPs towards multiple behaviours and strategies used.

Results

Nine thousand six hundred eighty‐one CPPs were identified. On average, communities had 74 different CPPs in place (standard deviation 30), with variation in documented CPPs (range 25–295). Most communities experienced a steady, modest increase in intensity scores over 10 years. CPP targeting scores suggested that communities expanded the focus of their efforts over time to include more behaviours and strategies.

Conclusions

Findings of this large‐scale study indicate that great variation exists across communities in the intensity and focus of community interventions being implemented to address childhood obesity.
Amide proton transfer imaging to predict tumor response to neoadjuvant chemotherapy in locally advanced rectal cancer
Authors: Nishie Akihiro , Asayama Yoshiki , Ishigami Kousei , Ushijima Yasuhiro , Takayama Yukihisa , Okamoto Daisuke , Fujita Nobuhiro , Tsurumaru Daisuke , Togao Osamu , Sagiyama Koji , Manabe Tatsuya , Oki Eiji , Kubo Yuichiro , Hida Tomoyuki , Hirahashi‐Fujiwara Minako , Keupp Jochen , Honda Hiroshi
Published: June 2018

Background and Aim

The amount of proteins and peptides can be estimated with amide proton transfer (APT) imaging. Previous studies demonstrated the usefulness of APT imaging to predict tumor malignancy. We determined whether APT imaging can predict the tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC).

Methods

Seventeen patients with LARC who underwent a pretherapeutic magnetic resonance examination including APT imaging and NAC (at least two courses) were enrolled. The APT‐weighted imaging (WI) signal intensity (SI) (%) was defined as magnetization transfer ratio asymmetry (MTRasym) at the offset of 3.5 ppm. Each tumor was histologically evaluated for the degree of degeneration and necrosis and then classified as one of five histological Grades (0, none; 1a, less than 1/3; 1b, 1/3 to 2/3; 2, more than 2/3; 3, all). We compared the mean APTWI SIs of the tumors between the Grade 0/1a/1b (low‐response group) and Grade 2/3 (high‐response group) by Student's t‐test. We used receiver operating characteristics curves to determine the diagnostic performance of the APTWI SI for predicting the tumor response.

Results

The mean APTWI SI of the low‐response group (n = 12; 3.05 ± 1.61%) was significantly higher than that of the high‐response group (n = 5; 1.14 ± 1.13%) (P = 0.029). The area under the curve for predicting the tumor response using the APTWI SI was 0.87. When ≥2.75% was used as an indicator of low‐response status, 75% sensitivity and 100% specificity of the APTWI SI were obtained.

Conclusion

Pretherapeutic APT imaging can predict the tumor response to NAC in patients with LARC.
Analysis of Train Collision Risk in the United States: 2001 to 2015
Authors: Turla Tejashree , Liu Xiang , Zhang Zhipeng , Bian Zheyong
Published: June 2018

Railways have a substantial contribution to the economy of the United States. However, a train accident can result in casualties and extensive damages to infrastructure and the environment. Most of the prior research focused on derailments or grade-crossing accidents rather than the study of train collisions. The Federal Railroad Administration (FRA) identifies over 300 causes for all types of accidents, among which we aim to recognize the major factors that cause train collisions. Evaluating how collision frequency and severity vary with the accident cause is the key part of this research, in order to identify, evaluate and mitigate transportation risk. This paper presents a statistical analysis of passenger and freight train collisions in the United States from 2001 to 2015 to statistically analyze train collision frequency, severity, accident cause, and safety risk. The analysis finds that human errors and signal failures are among the most common causes of train collisions in U.S. in the 15-year study period. There is a significant decline in the overall train collision frequency by year. By observing these trends with respect to train collisions, possible accident prevention strategies could be developed and implemented accordingly.
Simulating Fouling Material Transport in Ballast
Authors: Qian Yu , Zhu Shengwei , Wang Yi , Rizos Dimitris C.
Published: June 2018

A ballast layer is used to facilitate drainage and load transferring in railroad track structure. With tonnage accumulation, fine materials, such as coal dust, clay, locomotive sand, degraded ballast aggregate, and other small particles, will penetrate into the clean and uniformly graded ballast layer causing contamination, usually referred as fouling. Fouling is unfavorable to railroad track performance due to the reduced drainage and consequent engineering challenges including but not limited to mud pumping, excessive settlement, and reduced bearing capacity. Previous research has investigated the mechanical behavior of the fouled ballast in both the laboratory and the field environment. However, the fundamental mechanism that governs the manner in which the fouling materials are transported and accumulated in the ballast layer is not thoroughly understood. Researchers at the University of South Carolina have initiated the effort to investigate the fouling process in the ballast layer. High-fidelity computational fluid dynamics (CFD) simulation is used to study the fluid flow patterns in order to quantify the transport behavior of the fine particles within the ballast layer and potential impact to the track performance and drainage. Specifically, the ballast layer is treated as a porous material, and the fouling materials are modeled as distinct individual particles to assess the probability of their trajectory location. This paper presents the preliminary results of the simulated path of the fouling materials in the ballast layer under seepage, and demonstrates the capability of the developed algorithm to quantify the effects of the ballast layer characteristics on fouling materials transport. The findings from this study will be beneficial for optimizing shoulder ballast cleaning or undercutting practices.
Receiver Operating Characteristic (ROC) Analysis on the Wheel Impact Load Detector System of Metro-North Railroad
Authors: Stewart Monique , Pouryousef Hamed , Marquis Brian , Singh Som P. , Cakdi Demet
Published: June 2018

The Federal Railroad Administration (FRA) has partnered with Metro-North Railroad (MNR), Long Island Rail Road (LIRR) and New York & Atlantic Railway (NYA) to enhance operational safety through the implementation of wayside detection systems.

Currently, MNR has a four-track Wheel Impact Load Detector (WILD) system that has been operating since 2010 near the Grand Central Terminal. This paper discusses a Receiver Operating Characteristic (ROC) analysis of this existing WILD system in conjunction with the wheel maintenance practices since 2010.

Currently MNR’s operating procedures require a car with wheel(s) exhibiting a vertical peak load/mean load ratio, called dynamic ratio (DR), ≥3.0 to be shopped for repair. The analysis, using a 30-day repair window after detection, shows that 84% of the cars shopped for wheel(s) with DR≥3.0 required valid maintenance repairs.

The minimum number of total false records (false positive + false negative records, combined) were observed within the DR range of 2.7–2.8 when considering wheel flat defects only. An analysis of the false negative records inclusive of both flat and shell spots, showed that the minimum number of false records dropped slightly to a DR range of 2.6–2.7. The reported ROC analysis shows that MNR’s current DR≥3.0 to trigger inspection and maintenance actions is reasonable.
Vibration-Based Defect Detection for Freight Railcar Tapered-Roller Bearings
Authors: Montalvo Joseph , Tarawneh Constantine , Fuentes Arturo A.
Published: June 2018

The railroad industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the conductor of high risk defects. Many defective bearings may never be detected by TADS™ due to the fact that a high risk defect is considered a spall which spans more than 90% of a bearing’s raceway, and there are less than 20 systems in operation throughout the United States and Canada. Much like the TADS™, the HBD is a device that sits on the side of the rail tracks and uses a non-contact infrared sensor to determine the temperature of the train bearings as they roll over the detector. The accuracy and reliability of the temperature readings from this wayside detection system have been concluded to be inconsistent when comparing several laboratory and field studies. The measured temperatures can be significantly different from the actual operating temperature of the bearings due to several factors such as the class of railroad bearing and its position on the axle relative to the position of the wayside detector. Over the last two decades, a number of severely defective bearings were not identified by several wayside detectors, some of which led to costly catastrophic derailments. In response, certain railroads have attempted to optimize the use of the temperature data acquired by the HBDs. However, this latter action has led to a significant increase in the number of non-verified bearings removed from service. In fact, about 40% of the bearings removed from service in the period from 2001 to 2007 were found to have no discernible defects. The removal of non-verified (defect-free) bearings has resulted in costly delays and inefficiencies.

Driven by the need for more dependable and efficient condition monitoring systems, the University Transportation Center for Railway Safety (UTCRS) research team at the University of Texas Rio Grande Valley (UTRGV) has been developing an advanced onboard condition monitoring system that can accurately and reliably detect the onset of bearing failure. The developed system currently utilizes temperature and vibration signatures to monitor the true condition of a bearing. This system has been validated through rigorous laboratory testing at UTRGV and field testing at the Transportation Technology Center, Inc. (TTCI) in Pueblo, CO. The work presented here provides concrete evidence that the use of vibration signatures of a bearing is a more effective method to assess the bearing condition than monitoring temperature alone. The prototype bearing condition monitoring system is capable of identifying a defective bearing with a defect size of less than 6.45 cm2 (1 in2) using the vibration signature, whereas, the temperature profile of that same bearing will indicate a healthy bearing that is operating normally.
Predicting Flammability of Railcar Interior Finish With Small-Scale Heat Release Rate Data
Authors: Kraft Stefan , Lattimer Brian
Published: June 2018

There is interest in providing a heat release rate based flammability requirements for interior finish materials on railcars. As a result, a research study was performed to develop a simple empirical model that can predict the real scale fire performance of an interior finish material from ASTM E1354 cone calorimeter data. A simple to use model has been developed to predict whether a material will contribute significantly to the growth of a fire inside of a railcar. The model consists of a flammability parameter, defined as the difference between the average heat release rate and the ratio of the ignition time and the burn duration. As indicated by the model, the relative flammability of materials is based on the balance between the heat release rate and the ease of ignition relative to burning duration. This work is focused on the use of the model in predicting material fire growth performance in full scale NFPA 286 room/corner tests, which has not previously been performed. The empirical flammability model was developed to use parameters which were obtained from cone calorimeter tests at 50 kW/m2 and provides a single value for a material. Generally, materials that have a flammability parameter of greater than 0.7 were determined to cause flashover in the NFPA 286 test, while those less than 0.6 did not cause flashover. The materials in the region between these values are borderline, with some causing flashover and some not. An initial assessment of a database of passenger railcar materials using the flammability parameter model revealed that about 50% of materials that meet NFPA 130 flammability requirements using ASTM E162 have the potential to cause flashover in the NFPA 286 room-corner test.
Noteworthy Rail Accidents
Authors: Schlesinger Dave
Published: June 2018

Travel by rail in the United States is one of the safest modes of transportation available. On the rare occasion that major accidents do occur, they represent an opportunity for railroads to learn what has happened and what needs to be done to prevent reoccurrence. This paper provides several, detailed case studies of noteworthy passenger and rail transit accidents that have occurred in the United States, from the 1960s to the present. It discusses the outcome of these accidents, including changes that were implemented due to lessons learned. It also discusses unique and/or noteworthy aspects of each accident.
Occurrence of the quarantine mite pest Aculus schlechtendali (Acari: Eriophyidae) in apple orchards of Serra Gaúcha, Rio Grande do Sul state, Brazil
Authors: Ferla Noeli Juarez , Silva Darliane Evangelho , Navia Denise , Do Nascimento Joseane Moreira , Johann Liana , De Lillo Enrico
Published: June 2018

The aim of this work is to report the presence of Aculus schlechtendali (Nalepa, 1890) (Prostigmata: Eriophyidae) (Apple rust mite—ARM), in apple orchards of Serra Gaúcha, state of Rio Grande do Sul, Brazil. Surveys were conducted from apple leaves of Gala cultivar in a commercial orchard of Vacaria County (S 28' 34.540 W 050' 52.153) in the Northeast region of the state of Rio Grande do Sul, between November 2016 and January of 2017. The morphological traits and the relative measurements matched with those of A. schlechtendali. This is the first report of this mite pest in Brazil, so far regulated as a quarantine pest, and the third country report in South America. Consideration on the potential pest status of ARM is discussed.
Scaling of human brain size
Authors: Van Essen David C.
Published: June 2018

Higher cognitive regions are preferentially expanded in individuals with larger brains
Density functional study of guanidine-azole salts as energetic materials
Authors: Xu Si-Yu , Meng Zhou-Yu , Zhao Feng-Qi , Ju Xue-Hai
Published: June 2018

A series of guanidine cations and azole anions were designed for use as energetic salts. Their geometrical structures were optimized by the density functional theory (DFT) method. The counter ions were matched by the similar magnitude of the electron affinity (EA) of the cation and the ionization potential (IP) of the anion. The densities, heats of formation, detonation parameters, and impact sensitivity were predicted. The incorporation of guanidine cations and diazole anions are favorable to form thermal stable salts except cation A1. The diaminoguanidine cation has greater impact on the density and detonation properties of the salts than the triaminoguanidine cation. 2-Amino-3-nitroamino-4,5-nitro-dinitropyrazole is the best anion for advancing the detonation performance among all the anions. Incorporating the C=O bond into the guanidine cations enhances the density and detonation performance of the guanidine-azole salts. The salts containing III1–III4 anion have better detonation properties than HMX, indicating that these salts are potential energetic compounds. Compared with RDX or HMX, some salts with diaminoguanidine cation display lower impact sensitivity.
T-idempotent invariant modules
Authors: Atani Shahabaddin Ebrahimi , Khoramdel Mehdi , Hesari Saboura Dolati Pish
Published: June 2018

We introduce and investigate [Formula: see text]-idempotent invariant modules. We call an endomorphism [Formula: see text] of [Formula: see text], a [Formula: see text]-idempotent endomorphism if [Formula: see text] defined by [Formula: see text] is an idempotent and we call a module [Formula: see text] is [Formula: see text]-idempotent invariant, if it is invariant under [Formula: see text]-idempotents of its injective envelope. We prove a module [Formula: see text] is [Formula: see text]-idempotent invariant if and only if [Formula: see text], [Formula: see text] is quasi-injective, [Formula: see text] is quasi-continuous and [Formula: see text] is [Formula: see text]-injective. The class of rings [Formula: see text] for which every (finitely generated, cyclic, free) [Formula: see text]-module is [Formula: see text]-idempotent invariant is characterized. Moreover, it is proved that if [Formula: see text] is right q.f.d., then every [Formula: see text]-idempotent invariant [Formula: see text]-module is quasi-injective exactly when every nonsingular uniform [Formula: see text]-module is quasi-injective.
Mesenteric adipose tissue contributes to intestinal barrier integrity and protects against nonalcoholic fatty liver disease in mice
Authors: Wu Zhe , Tan Jiang , Chi Yujing , Zhang Feng , Xu Jun , Song Yang , Cong Xu , Wu Na , Liu Yulan
Published: June 2018

Visceral adipose tissue (VAT) is related to nonalcoholic fatty liver disease (NAFLD). However, the role of mesenteric adipose tissue (MAT), part of the VAT, in NAFLD is unclear. In the present study, we monitored the liver and four depots of the VAT in high-fat diet (HFD)-feeding mice at multiple time points (4, 8, and 12 wk). The MAT had become inflamed by the eighth week of HFD feeding, earlier than other depots of VAT. Furthermore, MAT removal after 8 wk of HFD resulted in more severe steatosis and more foci of inflammation infiltration, as well as higher NAFLD activity scores. Consistent with these findings, the mRNA expression of proinflammatory cytokines and lipid anabolism genes was increased in the livers of inflamed MAT-removal mice. MAT removal also injured the intestinal barrier and promoted intestinal inflammation. The bacterial load translocated to the liver and circulating levels of lipopolysaccharide were also evaluated in inflamed MAT-removal mice. In a coculture experiment involving adipocytes and intestinal epithelial cells, mRNA expression of zonula occludens-1 (ZO-1), and occludin in CT-26 cells was upregulated and permeability of monolayer Caco-2 cells was elevated under stimulation from adipocytes or inflamed adipocytes. Taken together, these results demonstrated that MAT removal damaged the intestinal barrier and aggravated NAFLD and that MAT inflammation may be a compensatory response to protect the liver by maintaining the intestinal barrier.

NEW & NOTEWORTHY The mesenteric adipose tissue (MAT) lies between the gut and liver and plays a critical role in hepatic metabolic diseases. In the present study, we found that the MAT was prone to inflammation in high-fat diet-fed mice. Removal of the inflamed MAT resulted in more hepatic inflammation, lipid accumulation, and decreased glucose tolerance. Furthermore, we showed that the MAT contributed to intestinal barrier integrity, thus clarifying why MAT removal aggravated nonalcoholic fatty liver disease.
T Cells and Hypertension: Solved and Unsolved Mysteries Regarding the Female Rat
Authors: Pai Amrita V. , Maddox Taylor , Sandberg Kathryn
Published: June 2018

T-cell function in female animal models of hypertension is poorly understood since most research is conducted in males. Our findings in Dahl-salt-sensitive and Dahl salt-resistant rats support prior research showing sex-specific T-cell effects in the pathophysiology of hypertension. Further studies are needed to inform clinical studies in both sexes and to provide clues into immune mechanisms underlying susceptibility and resilience to developing hypertension and associated disease.