bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle Stem Cell Niche Dysregulation in Volumetric Muscle Loss Injury
Authors: Anderson Shannon E. , Han Woojin M. , Srinivasa Vunya , Mohiuddin Mahir , Ruehle Marissa A. , Moon Austin , Shin Eunjung , San Emeterio Cheryl L. , Ogle Molly E. , Botchwey Edward A. , Willett Nick J. , Jang Young C.
Published: June 2018

Skeletal muscle has a remarkable regenerative capacity; however, after volumetric muscle loss (VML) due to traumatic injury or surgery this regenerative response is significantly diminished, causing chronic functional deficits. The critical defect size at which the muscle will not functionally recover has not yet been established and subsequently, the relative contribution of crucial muscle components, including muscle stem cells and the muscle stem cell niche, are unknown. In this study, we created VML injuries of 2, 3, or 4 mm diameter, full-thickness defects in the mouse quadriceps. The 2, 3, and 4 mm injuries resulted in a defect of 5, 15, or 30% of the quadriceps mass, respectively. At 14 and 28 days after injury, histological analyses revealed injury size-dependent differences in myofiber morphology and fibrosis; the number of small myofibers increased with increasing injury size. The results showed that the 3 mm injury was at a threshold point, as myofibers were unable to bridge the defect, there was persistent fibrosis and inflammation, and significantly increased number of myofibers with centrally located nuclei. We then further investigated the 3 mm VML for nerve and vascular regeneration. These injured muscles were accompanied by a drastic increase in denervated neuromuscular junctions (NMJ), while assessment of angiogenesis via micro-CT analysis revealed a significant increase in vascular volume primarily from small diameter vessels after VML injury. Collectively, these data indicate that the spatial and temporal control of the fibrotic and neuromotor response are critical to regeneration and could be potential therapeutic targets, as they are the most dysregulated components of the muscle stem cell niche after VML.
Coevolution of structural variation and optimization in sound systems of human language
Authors: Zhang Meng-Han , Gong Tao
Published: June 2018

Evolution of sound systems of human language is an optimization process to improve communicative effectiveness: The intrinsic structures of sound systems are constantly organized with respect to constraints in speech production and perception. However, there lack sufficient quantitative descriptions of this process, large-scale investigations on universal tendencies in sound systems, and explicit evidence on whether demographic and/or geographic factors can influence linguistic typology of sound systems. Here, we proposed two composite parameters, namely structural variation and optimization, to capture linguistic typology of sound systems, vowel systems in particular. Synchronic comparisons based on a large-scale vowel corpus of world languages revealed a universal negative correlation between the two parameters. Phylogenetic comparative analyses identified a correlated evolution of the two, but with distinct evolutionary modes: a gradual evolution of the structural variation and a punctuated equilibrium of the optimization. Mixed-effect models also reported significant effects of speaker population size and longitude on shaping vowel systems of world languages. All these findings elaborate the intrinsic evolutionary mechanism of sound systems, clarify the extrinsic, non-linguistic effects on shaping human sound systems, and quantitatively describe and interpret the evolution and typology of sound systems.
Field relationships and data collecting: dilemmas encountered in a construction organization
Authors: Nycyk Michael
Published: June 2018

Purpose

This paper is an autoethnographic account of field dilemmas encountered while undertaking research in a construction organization. The purpose of this paper is to provide a reflexive account for those who undertake organizational field studies and focusses on the issue of field relationships and data collection.

Design/methodology/approach

Vignettes are used providing vivid accounts of field interactions between author, informants and research team members, followed by a reflection on the consequences of these. Field notes and reflective journaling were used in the construction of the vignettes.

Findings

Data collection in organizations where informants have limited time for researchers involves building relationships that need much attention, compromise and addressing of dilemmas which arise. This autoethnography highlights this and reflects on lessons learnt of how to manage dilemmas in field relationships that require attention when they hinder data collection and prove detrimental to the research project’s progress.

Practical implications

This study informs those undertaking research in commercial organizations about the importance of managing relationships and solving potential field dilemmas.

Originality/value

This autoethnography adds to the discussion about how researchers negotiate complex relationships and the dilemmas that constrain data collection. The value of being reflective of dilemmas lies in understanding that challenging organizational field studies involves careful tending to informants’ and research stakeholders’ needs whilst remaining focused on one’s own research goals.
Formation, morphology and classification of colluvial soils: a review
Authors: Zádorová T. , Pení žek V.
Published: June 2018

Colluvial soils have received increased attention in different fields of environmental and geoarchaeological research over the past two decades. However, their pedological functions and status as specific soil units have seldom been discussed. The concepts and general understanding of the term ‘colluvial soil’ often vary; the definition of this term is vague and thus requires standardization. In this paper we define colluvial soils as soil units that underwent a specific profile development and record characteristics formed by specific processes. We also review and summarize concepts and definitions of colluvial soils in the geosciences, describe their morphology and properties, assess a typical colluvial profile and propose a new definition and inclusion of colluvial soils in soil classification systems. We suggest that colluvial soils should be defined as either (i) colluvisols, which are recent undeveloped soils formed by the periodic rejuvenation of a soil profile because of the accumulation of eroded topsoil or (ii) colluvium‐derived soils, which are soils that developed from colluvia that underwent various pedogenetic processes. The proposed criteria for the classification of colluvisols highlight (i) the accumulation of eroded soil material as the primary process in the formation of colluvisols, (ii) their specific terrain positions and (iii) the different types of development of colluvisol profiles.

Highlights

Concepts and general understanding of the term ‘colluvial soil’ vary and need standardization.

We distinguish two types of colluvial soil: colluvisols and colluvium‐derived soils.

We define three types of colluvisols reflecting variation in stratigraphy of their profiles.

We propose internationally applicable criteria for identification and classification of colluvisols.
Sampling at high spatial and temporal resolutions with an experimental chamber
Authors: Ouaknin H. , Weisbrod N. , Furman A.
Published: June 2018

Laboratory‐scale studies of the dynamics of soil biogeochemical processes often require destructive sampling for chemical, biological and genetic analyses. The consequences are either ‘end‐of‐experiment’ sampling or a set‐up with multiple experiments in parallel, of which some are sacrificed over time. We propose an alternative experimental set‐up to enable matrix sampling and monitoring at high spatiotemporal resolution of chemical, biological and physical properties. A customized experimental chamber was constructed, including an array of sensors on one side and hundreds of sampling ports on the other. A vertical unidirectional flow regime was maintained in the chamber, and soil samples were collected through ports that were not adjacent laterally to ones used in an earlier sampling campaign. We give an example of an experiment with such a chamber in which the environmental conditions (matric head and redox) were kept almost uniform in the horizontal dimension. Under these conditions nitrogen cycling was also almost the same in the lateral dimension. This system offers a unique combination of high spatial and temporal resolution sensors in the same system that is destructively sampled.

Highlights

A new experimental chamber allows high‐resolution sampling

In unidirectional flow, sacrificial sampling can be avoided
Mate choice behavior of female Eastern Gray Treefrogs (Hyla versicolor) is robust to anthropogenic light pollution
Authors: Underhill Victoria A. , Höbel Gerlinde
Published: June 2018

Human activities are drastically changing the amount of artificial light entering natural habitats. Because light pollution alters the sensory environment, it may interfere with behaviors ranging from prey detection and vigilance to mate choice. Here, we test the hypothesis that anthropogenic light pollution affects the mate choice behavior of female Eastern Gray Treefrogs (Hyla versicolor). We tested this hypothesis under two experimental light treatments that simulate the light pollution created by streetlights (expansion of lit areas and increased light intensity), and the light pollution created by headlights of passing vehicles (rapid fluctuations between bright and dark conditions). The hypothesis predicts that females tested under conditions simulating light pollution will show behavioral changes geared toward mitigating detection by predators, such as relaxed preferences, decreased choosiness for the normally preferred call, and differences in approach behavior (either more directional, faster, or stealthier movements, or no approach at all). Contrary to our prediction, we found that light pollution did not affect mate choice behavior in Gray Treefrogs, and should therefore neither interfere with population persistence nor affect the sexual selection regimes on male call traits of this species. However, we caution that this result does not imply that anthropogenic light pollution is of no concern for amphibian conservation, because behavioral responses to variation in nocturnal light levels (both in the natural as well as anthropogenically enhanced range) seem to be highly species‐specific in anurans. We encourage additional studies to help gage the vulnerability of anurans to anthropogenic light pollution.
Prophylactic bypassing agent use before and during immune tolerance induction in patients with haemophilia A and inhibitors to FVIII
Authors: Carpenter S. L. , Khair K. , Gringeri A. , Valentino L. A.
Published: June 2018

The development of high‐titre inhibitory antibodies (inhibitors) against factor VIII (FVIII) remains a challenge in the management of patients with haemophilia A (HA). Patients with high‐titre inhibitors are more likely to experience uncontrolled bleeding, physical disability from chronic arthropathy and premature death compared with those without this complication. Immune tolerance induction (ITI), utilizing repeated infusions of FVIII, is an effective therapeutic approach to eliminating inhibitory antibodies. This strategy can eradicate FVIII inhibitors, so that FVIII‐specific tolerance is induced. However, patients undergoing ITI are still vulnerable to the development of serious and/or repeated bleeding events. The efficacy of bypassing agents in preventing bleeding episodes has been widely proven in patients with HA and inhibitors to FVIII. Evidence suggests that reducing bleeding during ITI can also shorten the time to tolerance. There are concerns with the use of bypassing agents, including the cost of treatment, short half‐life, management of non‐responders and the risk of thrombosis. Despite these concerns, and the still limited evidence from prospective studies and consensus reports, the use of prophylaxis with bypassing agents during ITI has been gaining support. This review presents a rationale and current data supporting the use of prophylactic bypassing agents as effective and safe therapies to reduce the incidence of joint bleeding due to inhibitors and improve quality of life in patients with HA undergoing ITI.
Disappearing edge: the flowering period changes the distribution of insect pollinators in invasive goldenrod patches
Authors: Moroń Dawid , Skórka Piotr , Lenda Magdalena
Published: June 2018

The response of animals to the edge reveals the potential mechanism underlying the impact of invasive plants on native pollinators. Many invasive plants flower only during a part of the growing season, which creates a temporal pattern of the availability of resources. This can lead to the emergence or disappearance of the edge effect in the pollinator community in the patches dominated by alien plants.

We tested whether the variability in the supply of flower resources created by dense stands of flowering invasive goldenrods could create a temporal edge effect for pollinating insects in a grassland landscape. We surveyed pollinator communities along transects perpendicular to the goldenrod‐grassland edge. To understand the variation in edge effects, we surveyed the number of flowers, which are the main food resources for pollinators.

We found positive edge responses of abundance and species richness of all pollinator groups from the edges to the grassland interior before the goldenrod flowering period. During the goldenrod flowering period abundance and species richness of bees showed a neutral edge response, the response of butterflies and hoverflies towards the centre of the goldenrod patch were negative and positive respectively.

Our results revealed that the emergence of the edge effect in a pollinating insect community is associated with temporal usability of invasive plants as a food source. Thus, the combined outcome of the available resources and invasion of alien plants can help to understand the edge effect on pollinator distributions in the invaded landscapes.
Institutional Ownership and Future Stock Returns: An International Perspective
Authors: Dyakov Teodor , Wipplinger Evert
Published: June 2018

We investigate the risk‐adjusted performance of the aggregate equity holdings and trades of 13,807 active mutual funds located in 16 countries between 2001 and 2014. Using portfolio sorts, we find weak evidence that institutional holdings exhibit positive subsequent risk‐adjusted returns. However, any outperformance is unlikely to stem from short‐term informational advantage: stocks bought do not outperform stocks sold in the subsequent quarter. This finding is robust to regressions of subsequent stock returns on changes in institutional ownership and holds for different measurements of institutional trading.
The importance of data issues when comparing cystic fibrosis registry outcomes between countries: Are annual review FEV1 in the UK only collected when subjects are well?
Authors: Hoo Zhe Hui , Curley Rachael , Campbell Michael J. , Walters Stephen J. , Wildman Martin J.
Published: June 2018

Rationale, aims and objective

Cross‐country comparisons of cystic fibrosis (CF) outcomes can potentially identify variation in care but are dependent on data quality. An important assumption is that the UK annual review FEV1 is only collected during periods of clinical stability. If this assumption does not hold, results of FEV1 comparisons may be biased in favour of registries with encounter‐based FEV1. We aimed to test the assumption that CF annual reviews in the UK are only performed during periods of clinical stability.

Method

Prospective encounter‐based data collected in Sheffield (n = 174) was used to establish whether annual review FEV1 were always collected during periods of clinical stability and to determine the group‐level discrepancy between annual review vs best FEV1. We then went on to quantify the group‐level discrepancy between annual review and best annual FEV1 readings within the UK registry (n = 2995) to determine if the differences observed in Sheffield also apply to the wider UK data.

Results

Sheffield results showed a group‐level discrepancy between best and annual review FEV1 of −2.5% (95% CI −3.95% to −1.2%) for annual reviews performed during periods of clinical stability (n = 50). The group‐level discrepancy is larger at −8.0% (95% CI −11.2% to −4.9%) among annual reviews performed during periods of clinical instability (n = 13). Therefore, the magnitude of this group‐level discrepancy is a surrogate for the proportion of clinically stable annual reviews—smaller discrepancy indicates a higher proportion of clinically stable annual reviews and vice versa.

The overall group‐level discrepancy in the UK registry (−5.6%, 95% CI −5.9 to −5.4%) was similar to Sheffield (−6.1%, 95% CI −7.1 to −5.1%). Around 20% of the clinician reviewed, annual reviews in Sheffield were performed during periods of clinically instability.

Conclusions

Annual review FEV1 underestimates lung health of adults with CF in the UK and may bias cross‐country comparisons.
Self‐Competence and Depressive Symptoms in Middle–Late Adolescence: Disentangling the Direction of Effect
Authors: Ohannessian Christine McCauley , Vannucci Anna , Lincoln Courtney R. , Flannery Kaitlin M. , Trinh Ashley
Published: June 2018

This study examined the temporal relation between self‐competence (academic, social, athletic, physical appearance, and close friend) and depressive symptoms in a large, diverse community sample of 636 adolescents. Surveys were administered to all 10th‐ and 11th‐grade students at participating high schools at baseline (mean age = 16.10, SD = .71) and 1 year later. Girls reported higher levels of self‐competence in close friendships and more depressive symptoms, whereas boys reported higher levels of self‐competence in athletics and physical appearance. However, there were no gender differences in the associations between self‐competence and depressive symptoms. Results from autoregressive, cross‐lagged path analyses indicated that depressive symptoms predicted self‐competence more consistently than self‐competence predicted depressive symptoms during middle–late adolescence. Implications for prevention are discussed.
Using the indicator amino acid oxidation technique to study threonine requirements in horses receiving a predominantly forage diet
Authors: Mok Chan Hee , Levesque Crystal L. , Urschel Kristine L.
Published: June 2018

Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. To evaluate amino acid metabolism and requirements, the indicator amino acid oxidation (IAAO) method has been successfully used in other species. The objective of this research was to estimate threonine requirements in mature horses fed timothy hay and concentrate in 4:1 ratio using the IAAO method. Six Thoroughbred mares (579.9 ± 46.7 kg) received each of 6 levels of threonine intake, 41, 51, 61, 70, 80 and 89 mg/kg BW/day, in a randomly determined order. Each study period was 7‐day long, and on day 6, blood samples were collected before and 90 min after feeding to measure amino acid concentrations using HPLC. On day 7, horses underwent IAAO procedures, which included a 2‐hr primed, constant intravenous infusion of [13C]sodium bicarbonate to measure total CO2 production and a 4‐hr primed, constant oral administration of [1‐13C]phenylalanine to estimate phenylalanine oxidation to CO2. Blood and breath samples were collected to measure blood [13C]phenylalanine, using GC‐MS analysis and breath 13CO2 enrichment, using an infrared isotope analyser. Increasing threonine intake levels did not affect plasma phenylalanine oxidation by the ANOVA test (p > 0.05) but resulted in a linear decrease in phenylalanine oxidation (p = 0.04) without a breakpoint by the orthogonal linear contrast. This study is the first attempt to evaluate threonine requirements in horses by the IAAO method; however, threonine requirements are still unknown in mature horses at this time.
Optimization of surfactin production from Bacillus subtilis in fermentation and its effects on Clostridium perfringens‐induced necrotic enteritis and growth performance in broilers
Authors: Cheng Yeong‐Hsiang , Zhang Ning , Han Jin‐Cheng , Chang Ching‐Wen , Hsiao Felix Shih‐Hsiang , Yu Yu‐Hsiang
Published: June 2018

Bacillus species are commonly used as probiotics in the poultry feed industry for preventing infectious diseases and improving productivity by altering gastrointestinal microbiota. The growth parameters of Bacillus subtilis for surfactin production in fermentation and the benefits of surfactin on broiler chickens remain unclear. In this study, we examined the growth parameters of B. subtilis in fermentation and evaluated the effects of surfactin from B. subtilis‐fermented products on Clostridium perfringens‐induced necrotic enteritis and growth performance in broilers. Results showed that the highest viable biomass of B. subtilis was observed at 10% molasses and 2% yeast supplementation during fermentation. The 4‐ and 6‐day fermented B. subtilis products were heat‐, acid‐ and bile‐resistant. Furthermore, the 4‐day fermented B. subtilis products with the highest surfactin concentration showed the maximal antimicrobial activity against pathogens, including Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and C. perfringens. Dietary B. subtilis‐fermented product supplementation in broilers significantly improved intestinal morphology and necrotic lesions under C. perfringens challenge. Bacillus subtilis treatments could enhance broiler productivity, as well as promote bone quality and intestinal morphology. These results together indicate that B. subtilis‐fermented products containing surfactin have potential for the development as feed additives and use as possible substitutes for antibiotics to treat C. perfringens in the poultry industry.
Thermal niche evolution of functional traits in a tropical marine phototroph
Authors: Baker Kirralee G. , Radford Dale T. , Evenhuis Christian , Kuzhiumparam Unnikrishnan , Ralph Peter J. , Doblin Martina A.
Published: June 2018

Land‐based plants and ocean‐dwelling microbial phototrophs known as phytoplankton, are together responsible for almost all global primary production. Habitat warming associated with anthropogenic climate change has detrimentally impacted marine primary production, with the effects observed on regional and global scales. In contrast to slower‐growing higher plants, there is considerable potential for phytoplankton to evolve rapidly with changing environmental conditions. The energetic constraints associated with adaptation in phytoplankton are not yet understood, but are central to forecasting how global biogeochemical cycles respond to contemporary ocean change. Here, we demonstrate a number of potential trade‐offs associated with high‐temperature adaptation in a tropical microbial eukaryote, Amphidinium massartii (dinoflagellate). Most notably, the population became high‐temperature specialized (higher fitness within a narrower thermal envelope and higher thermal optimum), and had a greater nutrient requirement for carbon, nitrogen and phosphorus. Evidently, the energetic constraints associated with living at elevated temperature alter competiveness along other environmental gradients. While high‐temperature adaptation led to an irreversible change in biochemical composition (i.e., an increase in fatty acid saturation), the mechanisms underpinning thermal evolution in phytoplankton remain unclear, and will be crucial to understanding whether the trade‐offs observed here are species‐specific or are representative of the evolutionary constraints in all phytoplankton.
Interaction between the Wnt/β‐catenin signaling pathway and the EMMPRIN/MMP‐2, 9 route in periodontitis
Authors: Liu X. , Zhang Z. , Pan S. , Shang S. , Li C.
Published: June 2018

Background and Objectives

In periodontitis, the Wnt/β‐catenin signaling pathway is related to the metabolism of the alveolar bone; further, extracellular matrix metalloproteinase inducer (EMMPRIN) expression is correlated with matrix metalloproteinases (MMPs) expression and inflammation severity. The aim of this study was to perform a preliminary investigation of the interaction between the Wnt/β‐catenin signaling pathway and the EMMPRIN/MMPs route in periodontitis.

Material and Methods

Chronic periodontitis and healthy gingival tissues were obtained to detect the expression of Wnt3a, β‐catenin, EMMPRIN and MMP‐2, 9 by using immunohistochemical analysis. The human immortalized oral epithelial cell/human gingival fibroblast direct co‐culture model was treated with 10 μg/mL Porphyromonas gingivalis lipopolysaccharide (Pg. LPS). Anti‐EMMPRIN antibody was used to block the effect of EMMPRIN. Dickkopf‐1 (DKK‐1) and Wnt3a were used as the inhibitor and activator of the Wnt/β‐catenin signaling pathway, respectively. Immunofluorescence was performed to visualize the localization of β‐catenin and EMMPRIN. Expression of the EMMPRIN, MMP‐2, 9 and Wnt pathway's components was confirmed by western blotting and quantitative real‐time polymerase chain reaction.

Results

Higher levels of Wnt3a, β‐catenin, EMMPRIN and MMP‐2, 9 were observed in chronic periodontitis gingival tissues compared with controls. Pg. LPS significantly enhanced β‐catenin, p‐GSK‐3β, EMMPRIN and MMP‐2, 9 inductions in the human immortalized oral epithelial cell/human gingival fibroblast co‐culture model. Anti‐EMMPRIN antibody markedly reduced the expression of MMP‐2, 9 only in the presence of Pg. LPS. Co‐expression of β‐catenin and EMMPRIN was detected in the co‐culture model. DKK‐1 inhibited Wnt pathway, but upregulated the EMMPRIN/MMP‐2, 9 routes. In contrast, activating Wnt pathway by Wnt3a repressed the EMMPRIN/MMP‐2, 9 routes. The promotion effect of DKK‐1 on MMP‐2, 9 expressions was partially inhibited by the anti‐EMMPRIN antibody. In addition, anti‐EMMPRIN antibody led to a drastic decrease in β‐catenin and p‐GSK‐3β.

Conclusion

In periodontitis, EMMPRIN regulates MMP‐2, 9 expressions, the activation of Wnt/β‐catenin signaling pathway downregulates the EMMPRIN/MMP‐2, 9 routes and the blockade of EMMPRIN attenuates Wnt/β‐catenin signaling pathway.
Forecasting Hepatitis C liver disease burden on real‐life data. Does the hidden iceberg matter to reach the elimination goals?
Authors: Kondili Loreta A. , Robbins Sarah , Blach Sarah , Gamkrelidze Ivane , Zignego Anna L. , Brunetto Maurizia R. , Raimondo Giovanni , Taliani Gloria , Iannone Andrea , Russo Francesco P. , Santantonio Teresa A. , Zuin Massimo , Chessa Luchino , Blanc Pierluigi , Puoti Massimo , Vinci Maria , Erne Elke M. , Strazzabosco Mario , Massari Marco , Lampertico Pietro , Rumi Maria G. , Federico Alessandro , Orlandini Alessandra , Ciancio Alessia , Borgia Guglielmo , Andreone Pietro , Caporaso Nicola , Persico Marcello , Ieluzzi Donatella , Madonia Salvatore , Gori Andrea , Gasbarrini Antonio , Coppola Carmine , Brancaccio Giuseppina , Andriulli Angelo , Quaranta Maria G. , Montilla Simona , Razavi Homie , Melazzini Mario , Vella Stefano , Craxì Antonio ,   PITER Collaborating Group
Published: June 2018

Background & Aims

Advances in direct‐acting antiviral treatment of HCV have reinvigorated public health initiatives aimed at identifying affected individuals. We evaluated the possible impact of only diagnosed and linked‐to‐care individuals on overall HCV burden estimates and identified a possible strategy to achieve the WHO targets by 2030.

Methods

Using a modelling approach grounded in Italian real‐life data of diagnosed and treated patients, different linkage‐to‐care scenarios were built to evaluate potential strategies in achieving the HCV elimination goals.

Results

Under the 40% linked‐to‐care scenario, viraemic burden would decline (60%); however, eligible patients to treat will be depleted by 2025. Increased case finding through a targeted screening strategy in 1948‐1978 birth cohorts could supplement the pool of diagnosed patients by finding 75% of F0‐F3 cases. Under the 60% linked‐to‐care scenario, viraemic infections would decline by 70% by 2030 but the patients eligible for treatment will run out by 2028. If treatment is to be maintained, a screening strategy focusing on 1958‐1978 birth cohorts could capture 55% of F0‐F3 individuals. Under the 80% linked‐to‐care scenario, screening limited in 1968‐1978 birth cohorts could sustain treatment at levels required to achieve the HCV elimination goals.

Conclusion

In Italy, which is an HCV endemic country, the eligible pool of patients to treat will run out between 2025 and 2028. To maintain the treatment rate and achieve the HCV elimination goals, increased case finding in targeted, high prevalence groups is required.
Habitat loss and fragmentation reduce effective gene flow by disrupting seed dispersal in a neotropical palm
Authors: Browne Luke , Karubian Jordan
Published: June 2018

Habitat loss and fragmentation often reduce gene flow and genetic diversity in plants by disrupting the movement of pollen and seed. However, direct comparisons of the contributions of pollen vs. seed dispersal to genetic variation in fragmented landscapes are lacking. To address this knowledge gap, we partitioned the genetic diversity contributed by male gametes from pollen sources and female gametes from seed sources within established seedlings of the palm Oenocarpus bataua in forest fragments and continuous forest in northwest Ecuador. This approach allowed us to quantify the separate contributions of each of these two dispersal processes to genetic variation. Compared to continuous forest, fragments had stronger spatial genetic structure, especially among female gametes, and reduced effective population sizes. We found that within and among fragments, allelic diversity was lower and genetic structure higher for female gametes than for male gametes. Moreover, female gametic allelic diversity in fragments decreased with decreasing surrounding forest cover, while male gametic allelic diversity did not. These results indicate that limited seed dispersal within and among fragments restricts genetic diversity and strengthens genetic structure in this system. Although pollen movement may also be impacted by habitat loss and fragmentation, it nonetheless serves to promote gene flow and diversity within and among fragments. Pollen and seed dispersal play distinctive roles in determining patterns of genetic variation in fragmented landscapes, and maintaining the integrity of both dispersal processes will be critical to managing and conserving genetic variation in the face of continuing habitat loss and fragmentation in tropical landscapes.
Characteristics of Lifeline, Crisis Line, Service Users Who Have Died by Suicide
Authors: Ramsey Colette , Ennis Edel , O'Neill Siobhan
Published: June 2018

Objective

Despite their widespread use, there is limited evidence on whether crisis lines are effective, how to identify callers at risk or the best ways of supporting callers to prevent suicide. This study compared the features of callers and call patterns in service users who had died by suicide with those who were currently alive from 2008 to 2011.

Methods

Using information contained on Contact's (Northern Ireland's “Lifeline” service) Client Information Management System (CIMS), 118 deaths by suicide from 2008 to 2011 were compared with a matched control group (matched on age, gender, and main presenting issue on first contact) who had not died by suicide.

Results

Clients who had “check‐in” calls were significantly less likely to die by suicide. Those with a substance dependency or those who had made a prior suicide attempt were significantly more likely to die by suicide. Duration of service access had a negative association with suicide risk.

Conclusions

“Check‐in” calls are an important part of the service. Information on previous suicide attempts and substance dependency may be useful in identifying callers who may benefit from proactive support and outreach. Wider interventions are needed to promote service user follow‐up and to encourage longer term engagement with the service.
Premature leaf senescence 3, encoding a methyltransferase, is required for melatonin biosynthesis in rice
Authors: Hong Yongbo , Zhang Yingxin , Sinumporn Sittipun , Yu Ning , Zhan Xiaodeng , Shen Xihong , Chen Daibo , Yu Ping , Wu Weixun , Liu Qunen , Cao Zhaoyun , Zhao Chunde , Cheng Shihua , Cao Liyong
Published: June 2018

Premature leaf senescence in rice is one of the most common factors affecting the plant's development and yield. Although methyltransferases are involved in diverse biological functions, their roles in rice leaf senescence have not been previously reported. In this study, we identified the premature leaf senescence 3 (pls3) mutant in rice, which led to early leaf senescence and early heading date. Further investigations revealed that premature leaf senescence was triggered by the accumulation of reactive oxygen species. Using physiological analysis, we found that chlorophyll content was reduced in the pls3 mutant leaves, while hydrogen peroxide (H2O2) and malondialdehyde levels were elevated. Consistent with these findings, the pls3 mutant exhibited hypersensitivity to exogenous hydrogen peroxide. The expression of other senescence‐associated genes such as Osh36 and RCCR1 was increased in the pls3 mutant. Positional cloning indicated the pls3 phenotype was the result of a mutation in OsMTS1, which encodes an O‐methyltransferase in the melatonin biosynthetic pathway. Functional complementation of OsMTS1 in pls3 completely restored the wild‐type phenotype. We found leaf melatonin content to be dramatically reduced in pls3, and that exogenous application of melatonin recovered the pls3 mutant's leaf senescence phenotype to levels comparable to that of wild‐type rice. Moreover, overexpression of OsMTS1 in the wild‐type plant increased the grain yield by 15.9%. Our results demonstrate that disruption of OsMTS1, which codes for a methyltransferase, can trigger leaf senescence as a result of decreased melatonin production.
Accessible Sleeper for the Next Generation Passenger Rail Vehicles
Authors: Tabattanon Kamolnat , Hunter-Zaworski Kate
Published: June 2018

This Safety IDEA project-31 extends the design process for the accessible sleeper compartments to include 3-D digital modeling and anthropometric analyses and uses a full-scale soft mock-up of the sleeper compartment. The use of computer-aided design tools permits human factors constraints, including minimum spatial requirements and reach limitations, to be determined within the conceptual design phase without physical prototyping and data collection. In this ongoing study, physical prototyping in the form of a full-scale soft mock-up is used to validate digital results. Successful validation would indicate that anthropometric digital human models based on regular anthropometric databases may be used to design for populations with reduced mobility, provided that the wheeled mobility devices are modelled appropriately and advance the design process for accessible spaces. The soft mock-up permits spatial evaluation by the general public including people with disabilities. An online survey is also available to gather feedback and the needs and values of the target population. Representatives of the passenger rail industry are involved throughout the project and have been invited to participate in the evaluation of the soft mock up. The results of the project are validated designs for new accessible sleeper compartments for bi-level and single-level rail cars and include seating, sleeping, and restroom spaces. This will be disseminated for use by the passenger rail industry.
Addressing Future Rail Network Performance Challenges Through Effective Structural Health Monitoring
Authors: Davis Jenna , Vallely Patrick , Papaelias Mayorkinos , Huang Zheng
Published: June 2018

Operational efficiency is one of the key performance indicators for all railroad systems. Infrastructure inspection and maintenance engineers are tasked with the responsibility of ensuring the reliability, availability, maintainability and safety of the railroad network. However, as rolling stock traffic density increases throughout the network, inspection and maintenance opportunities become less readily available. Inspection and maintenance activities normally take place at night, when there is little or no train movement to avoid disruption of normal railroad network operation. In addition, conventional inspection methodologies fail to deliver the efficiency required for the optimization of maintenance decisions, particularly with respect to track renewals, due to their defect detection sensitivity and level of resolution limitations. The fact that critical structural components such as rails and crossings (frogs) are randomly loaded increases the degree of uncertainty when trying to estimate their remaining service lifetime. Maintenance decisions are predominantly based on the feedback received from inspection engineers, coupled with empirical knowledge that has been gained over the years. The use of structural degradation models is too risky due to the uncertainty arising from the variable dynamic loads sustained by the rail track. The use of structural health monitoring techniques offers significant advantages over conventional approaches. First of all, it is non-intrusive and does not interrupt normal rail traffic operations. Secondly, defects can be detected and evaluated in real-time whilst their evolution can be monitored continuously, enabling maintenance to be scheduled in advance and at times where the need for rail network availability at the section concerned is at its lowest. This paper analyzes the potential risks and benefits of a gradual shift from traditional inspection approaches to advanced structural health monitoring techniques.
Advances in Filtration in Automatic Lube Oil Filters
Authors: Stanley Ian , Schmitz Stefan
Published: June 2018

In 2006 an automatic lube oil filtration system with an automatic backflushing filter and a centrifuge for diesel locomotives was presented at the ASME Spring Technical Conference [1]. The filter cleans itself continuously and the system can be used instead of conventional disposable paper filters to reduce servicing requirements, improve oil cleanliness and reduce the oil system’s exposure to contaminants.

In 2015 at the ASME Fall Technical Conference, a development of the system was presented that introduced an electric pump to boost both centrifuge and automatic filter performance at lower engine speeds, as seen during locomotive idling or coasting.

The next development addresses the automatic filter mesh, something that has not improved substantially over the last 20 years.

The main challenge with improving the mesh for a backflushing filter has been balancing the filtration grade with self-cleaning performance. By going to a finer mesh that catches ever smaller particles, the filter element tends to become more difficult to backflush. For a given wire diameter the free flow area also decreases when the openings become smaller, reducing the maximum mesh loading. Reducing the diameter of the wire used increases the free flow area, but makes the mesh more fragile and difficult to weld.

A recent advancement in the mesh design now allows the automatic filter to filter the oil to a much finer degree than was previously possible while maintaining high self-cleaning performance. The filtration performance was evaluated by using the multi-pass method according to ISO 16889, while the backflushing performance was evaluated on our in-house test stand. Currently these elements are being field tested.

Being able to filter and separate much smaller particles is expected to reduce long term engine wear and, in certain cases, improve oil life.
Railroad Rails Containing Electrode-Induced Pitting From Pressure Electric Welding
Authors: Luck Blain R. , Vigilante Gregory N. , Ethier Christopher L. , Troiano Edward J. , Marquis Brian , Yu Hailing , Jeong David Y.
Published: June 2018

The Federal Railroad Administration (FRA) routinely conducts investigations of railroad accidents to determine causation and any contributing factors to help the railroad industry implement corrective measures that may prevent similar incidents in the future. Over the past decade, FRA has investigated multiple broken rail accidents in which fractures in the rail web were identified. The common features observed in the recovered rail fragments from these accidents included welds and spots or burn marks on the web, indicating that the rails were joined together by pressure electric welding.

Pressure electric welding uses a welding head that clamps around two opposing rail ends, pressing an electrode on each rail, then hydraulically pulling the rail ends together while arcing current through the electrodes into the rails, causing them to essentially melt together to form a continuous rail.

Based on the similarities observed in the web fractures, FRA rail integrity specialists hypothesized that stray (i.e. inadvertent and unwanted) arcing during pressure electric welding can result in the formation of burns or pits on the rail where it makes contact with the electrodes. Moreover, these electrode-induced pits behave as stress raisers (also referred to as stress concentrations). Fatigue cracks often develop at locations of stress concentration. Once a fatigue crack initiates, the localized stress encourages the growth of the crack, which may potentially lead to rail failure.

This paper describes the forensic evaluations of three railroad rails containing electrode-induced pitting. These evaluations include: magnetic particle inspection to nondestructively detect cracks emanating from the pitting; fractography to study the fracture surfaces of the cracks; metallography to study the microstructure; analysis of chemical composition; and measurements of tensile mechanical properties and fracture toughness of rail steel. Moreover, the results of these evaluations confirm the hypothesis postulated by FRA that stray arcing during pressure electric welding can cause electrode-induced pitting.
Providing Cyber Situational Awareness (CSA) for PTC Using a Distributed IDS System (DIDS)
Authors: Kolli Satish , Lilly Joshua , Wijesekera Duminda
Published: June 2018

American Railroads are planning to complete implementation of their Positive Train Control (PTC) systems by 2020 with the primary safety objectives of avoiding inter-train collisions, train derailments and ensuring railroad worker safety. Under published I-ETMS specifications, the onboard unit (OBU) communicates with two networks; (1) the Signaling network that conveys track warrants to occupy blocks etc. and (2) the Wayside Interface Unit (WIU) network, a sensor network situated on tracks to gather navigational information. These include the status of rail infrastructure (such as switches) and any operational hazards that may affect the intended train path. In order to facilitate timely delivery of messages, PTC systems will have a reliable radio network operating in the reserved 220MHz spectrum, although the PTC system itself is designed to be a real-time fail safe distributed control systems. Both the signaling and the WIUs communicate their information (track warrants, speed restrictions, and Beacon status) using software defined radio networks. Given that PTC systems are controlled by radio networks, they are subjected to cyber-attacks.

We show a design and a prototype implementation of a PTC Cyber Situational awareness system that gathers information from WIU devices and Locomotives for the use of rail operators. In order to do so, we designed secure IDS components to reside on the On Board Units (OBU), signaling points (SP) and the WIUs that gather real-time status information and share them with the Back Office system to provide the cyber-security health of the communication fabric. Our system is able to detect and share information about command replay, hash breaking guessing and message corruption attacks.
Simulation Methodology for Occupant Safety Assessment of Indian Railway Passenger Coach
Authors: Prabhune Prajakta , Deb Anindya , Balasubramani G.
Published: June 2018

This work intends to lay the groundwork for Computer Aided Engineering (CAE)-based occupant safety of a typical tier-III Indian Railway (IR) passenger coach in a collision accident. Our previous work presented in International Crashworthiness Conference 2010 under the title “Simulation of Crash Behaviour of a Common Indian Railway Passenger Coach” provided crashworthiness assessment of a typical tier-III passenger coach structure for representative head-on collision scenarios namely, against an identical passenger coach and against a stationary locomotive. These scenarios were envisioned to be part of a bigger accident scenario e.g - head-on collision between two trains moving towards each other. Analysis of involved chain of events for entire rolling stock and resulting internal collisions between individual passenger cars was out of scope of this work and necessary inputs were obtained from available literature on the same. This work used a full scale Finite Element (FE) simulation model and commercial explicit solver LS-Dyna. FE model was validated using International Railway Union (UIC) code OR566 specified proof loads for design. Simulation methodology used for dynamic impact was validated by component level crushing experiments using a drop tower facility. Material modelling incorporated strain rate effect on yield strength which is essential for obtaining accurate structural deformations under dynamic impact loading. Contacts were modelled using the penalty method option provided by the solver. This model was simulated for collisions at 30, 40 and 56 km/h against a stationary rigid barrier. Collision speeds were chosen to simulate impact energies involved in collision scenarios as mentioned above. The structure was found to exhibit global bending deformation and jackknifing with pivot position at the door section. In this paper, we present an extension of this work — coupled occupant safety simulation and injury assessment. It was accomplished by recording head, neck, chest and knee responses of a Hybrid-III 50th percentile male Anthropomorphic Test Device (ATD) FE model, seated in passenger position on lower berth of the first cabin of a passenger car. Interiors were modelled to represent the actual structure. Dummy model was adapted to passenger cabin’s excessive mobility conditions and responses were revalidated against Federal Motor Vehicle Safety Standards (FMVSS) limits. Injury interpretation was based on Abbreviated Injury Scale (AIS), automotive injury criteria and injury risk curves for Head Injury Criterion (HIC), thoracic spine acceleration, neck bending moment in flexion and extension and knee force. This study provides with estimates of injury and fatality based on computer simulation of accident scenarios. However, attempts of correlating to any available injury and fatality statistics were out of scope of this study.