bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joint seasonality in geographic and ecological spaces, illustrated with a partially migratory bird
Authors: Basille Mathieu , Watling James , Romañach Stephanie , Borkhataria Rena 
Published: January 2019

AbstractAs most species live in seasonal environments, considering varying conditions is essential to understand species dynamics in both geographic and ecological spaces. Both resident and migratory species need to contend with seasonality, and balance settling in favorable areas with tracking favorable environmental conditions during the year. We present an exploratory framework to jointly investigate a species’ niche in geographic and ecological spaces, applied to wood storks (Mycteria americana), which are partially migratory wading birds, in the southeastern U.S. We concurrently described monthly geographic distributions and climatic niches based on temperature and precipitation. Geographic distributions of wood storks were more similar throughout the year than were climatic niches, suggesting that birds stay within specific areas seasonally, rather than tracking areas of similar climate. However, wood storks expressed consistent selection of warm areas during the winter, and wet areas during the summer, indicating that the selection of seasonal ranges may be directly related to environmental conditions across the entire range. Our flexible framework, which simultaneously considered geographic and ecological spaces, suggested that tracking climate alone did not explain seasonal distributions of wood storks in breeding and non-breeding areas.
Transcriptomic basis and evolution of ant nurse-larval social regulatory interactions
Authors: Warner Michael R. , Mikheyev Alexander S. , Linksvayer Timothy A. 
Published: January 2019

AbstractDevelopment is often strongly regulated by interactions among close relatives, but the underlying molecular mechanisms are largely unknown. In eusocial insects, interactions between caregiving worker nurses and larvae regulate larval development and resultant adult phenotypes. Here, we begin to characterize the social interactome regulating ant larval development by collecting and sequencing the transcriptomes of interacting nurses and larvae across time. We find that the majority of nurse and larval transcriptomes exhibit parallel expression dynamics across larval development. We leverage this widespread nurse-larva gene co-expression to infer putative social gene regulatory networks acting between nurses and larvae. Genes with the strongest inferred social effects tend to be peripheral elements of within-tissue regulatory networks and are often known to encode secreted proteins. This includes interesting candidates such as the nurse-expressedgiant-lens, which may influence larval epidermal growth factor signaling, a pathway known to influence various aspects of insect development. Finally, we find that genes with the strongest signatures of social regulation tend to experience relaxed selective constraint and are evolutionarily young. Overall, our study provides a first glimpse into the molecular and evolutionary features of the social mechanisms that regulate all aspects of social life.Author SummarySocial interactions are fundamental to all forms of life, from single-celled bacteria to complex plants and animals. Despite their obvious importance, little is known about the molecular causes and consequences of social interactions. In this paper, we study the molecular basis of nurse-larva social interactions that regulate larval development in the pharaoh antMonomorium pharaonis. We infer the effects of social interactions on gene expression from samples of nurses and larvae collected in the act of interaction across a developmental time series. Gene expression appears to be closely tied to these interactions, such that we can identify genes expressed in nurses with putative regulatory effects on larval gene expression. Genes which we infer to have strong social regulatory effects tend to have weak regulatory effects within individuals, and highly social genes tend to experience relatively weaker natural selection in comparison to less social genes. This study represents a novel approach and foundation upon which future studies at the intersection of genetics, behavior, and evolution can build.
WNT/β-CATENIN modulates the axial identity of ES derived human neural crest
Authors: Gomez Gustavo A. , Prasad Maneeshi S. , Wong Man , Charney Rebekah M. , Shelar Patrick B. , Sandhu Nabjot , Hackland James O.S. , Hernandez Jacqueline C. , Leung Alan W. , García-Castro Martín I. 
Published: January 2019

ABSTRACTThe WNT/β-CATENIN pathway is critical for neural crest (NC) formation. However, the effects of the magnitude of the signal remains poorly defined. Here we evaluate the consequences of WNT magnitude variation in a robust model of human NC formation. This model is based on human embryonic stem cells induced by WNT signaling through the small molecule CHIR9902. In addition to its known effect on NC formation, we find that the WNT signal modulates the anterior-posterior axial identity of NCCs in a dose dependent manner, with low WNT leading to anterior OTX+, HOX-NC, and high WNT leading to posterior OTX−, HOX+ NC. Differentiation tests of posterior NC confirm expected derivatives including posterior specific adrenal derivatives, and display partial capacity to generate anterior ectomesenchymal derivatives. Furthermore, unlike anterior NC, posterior NC transit through a TBXT+/SOX2+ neuromesodermal precursor-like intermediate. Finally, we analyze the contributions of other signaling pathways in posterior NC formation, and suggest a critical role for FGF in survival/proliferation, and a requirement of BMP for NC maturation. As expected RA and FGF are able to modulate HOX expression in the posterior NC, but surprisingly, RA supplementation prohibits anterior, but only reduces, posterior NC formation. This work reveals for the first time that the amplitude of WNT signaling can modulate the axial identity of NC cells in humans.
The semantic segmentation approach for normal and pathologic tympanic membrane using deep learning
Authors: Seok Jungirl , Song Jae-Jin , Koo Ja-Won , Kim Hee Chan , Choi Byung Yoon 
Published: January 2019

AbstractObjectivesThe purpose of this study was to create a deep learning model for the detection and segmentation of major structures of the tympanic membrane.MethodsTotal 920 tympanic endoscopic images had been stored were obtained, retrospectively. We constructed a detection and segmentation model using Mask R-CNN with ResNet-50 backbone targeting three clinically meaningful structures: (1) tympanic membrane (TM); (2) malleus with side of tympanic membrane; and (3) suspected perforation area. The images were randomly divided into three sets – taining set, validation set, and test set – at a ratio of 0.6:0.2:0.2, resulting in 548, 187, and 185 images, respectively. After assignment, 548 tympanic membrane images were augmented 50 times each, reaching 27,400 images.ResultsAt the most optimized point of the model, it achieved a mean average precision of 92.9% on test set. When an intersection over Union (IoU) score of greater than 0.5 was used as the reference point, the tympanic membrane was 100% detectable, the accuracy of side of the tympanic membrane based on the malleus segmentation was 88.6% and detection accuracy of suspicious perforation was 91.4%.ConclusionsAnatomical segmentation may allow the inclusion of an explanation provided by deep learning as part of the results. This method is applicable not only to tympanic endoscope, but also to sinus endoscope, laryngoscope, and stroboscope. Finally, it will be the starting point for the development of automated medical records descriptor of endoscope images.
Crystal structure ofMycobacterium tuberculosisFadB2 implicated in mycobacterial β-oxidation
Authors: Cox Jonathan A. G. , Taylor Rebecca C. , Brown Alistair K. , Attoe Samuel , Besra Gurdyal S. , Fütterer Klaus 
Published: January 2019

The intracellular pathogenMycobacterium tuberculosisis the causative agent of tuberculosis, which is a leading cause of mortality worldwide. The survival ofM. tuberculosisin host macrophages through long-lasting periods of persistence depends, in part, on breaking down host cell lipids as a carbon source. The critical role of fatty-acid catabolism in this organism is underscored by the extensive redundancy of the genes implicated in β-oxidation (∼100 genes). In a previous study, the enzymology of theM. tuberculosisL-3-hydroxyacyl-CoA dehydrogenase FadB2 was characterized. Here, the crystal structure of this enzyme in a ligand-free form is reported at 2.1 Å resolution. FadB2 crystallized as a dimer with three unique dimer copies per asymmetric unit. The structure of the monomer reveals a dual Rossmann-fold motif in the N-terminal domain, while the helical C-terminal domain mediates dimer formation. Comparison with the CoA- and NAD+-bound human orthologue mitochondrial hydroxyacyl-CoA dehydrogenase shows extensive conservation of the residues that mediate substrate and cofactor binding. Superposition with the multi-catalytic homologueM. tuberculosisFadB, which forms a trifunctional complex with the thiolase FadA, indicates that FadB has developed structural features that prevent its self-association as a dimer. Conversely, FadB2 is unable to substitute for FadB in the tetrameric FadA–FadB complex as it lacks the N-terminal hydratase domain of FadB. Instead, FadB2 may functionally (or physically) associate with the enoyl-CoA hydratase EchA8 and the thiolases FadA2, FadA3, FadA4 or FadA6 as suggested by interrogation of the STRING protein-network database.
Effect of non-conventional heat treatment of API X60 pipeline steel on corrosion resistance and stress corrosion cracking susceptibility
Authors: Jacobo Luis Ricardo , Garcia Rafael , Lopez Victor Hugo , Contreras Antonio 
Published: January 2019

PurposeThe purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility through slow strain rate tests (SSRT) in NS4 solution and congenital water (CW) to assess external and internal SCC, respectively.Design/methodology/approachAPI X60 steel was heat treated at a temperature of 1,200°C for 30 min followed by water quenching. Specimens from this steel were machined according to NACE TM 198. SSRT were performed in a constant extension rate tests (CERT) machine at room temperature at a strain rate of 1 × 10–6s–1. For this purpose, a glass cell was used. Corrosion behavior was evaluated through polarization curves (PCs).FindingsThe SCC index obtained from SSRT indicates that the steel heat treated could be susceptible to SCC in CW and NS4 solution; the mechanism of SCC was hydrogen embrittlement. Thus, CW may promote the SCC phenomenon in pipelines. HT improves the steel corrosion resistance. Higher corrosion rate (CR) was observed when the steel is exposed to CW. The corrosion process in X60 steel shows that the oxidation reaction in the anodic branch corresponds to an activation process, and the cathode branches reveal a diffusion process.Originality/valueThe purpose of the heat treatment applied to X60 steel was to generate a microstructure of acicular ferrite to improve the corrosion resistance and SCC behavior.
LCA of the maintenance of a piston-prop engine
Authors: Şöhret Yasin , Ekici Selcuk , Altuntas Onder , Karakoc T. Hikmet 
Published: January 2019

Purpose
This study aims to introduce an approach to evaluate environmental impact of a piston-prop engine from the view point of life cycle assessment (LCA).

Design/methodology/approach
In the aviation industry, safety is an important issue. For reliable and safe flights, the maintenance of aerial vehicles and engines is mandatory. Additionally, regular and correct maintenance plays a key role in keeping efficiency at a high level. With this in mind, a LCA of a regular 50 hourly maintenance process of Cessna type training aircraft is conducted. During the assessment, the starting of the engine before maintenance, replacement of the oil filter, test procedure of the spark plugs, a compressor test, engine cleaning and engine starting following maintenance are taken into account.

Findings
At the end of the study, normalization and characterization values for the maintenance, electricity consumption during maintenance and used fuel are obtained.

Practical implications
Regarding the number of this type aircraft worldwide, the current study offers a valuable contribution to the literature. The authors also intend to introduce an approach which may be useful for the assessment of large body aircraft still in service.

Originality/value
The present paper is a pioneer for future applications of LCA methodology to piston-prop engines and training aircraft.
Colombian millennials at the workplace
Authors: Roman-Calderon Juan Pablo , Gonzales-Miranda Diego René , García Gustavo A. , Gallo Oscar 
Published: January 2019

PurposeThe purpose of this paper is to present a study on the antecedents of turnover intentions (TOI) of millennial Colombian employees. A theoretical model in which positive work-family interaction, professional respect (PR) and meaning predicted TOI is simultaneously tested in Millennials and Xers.Design/methodology/approachThe authors used a multigroup structural equation approach to analyze the data provided by 2,157 Millennials and 279 Xers. Participants work in 11 companies from five Colombian cities. City, age, sex, tenure and wage are included as control variables to respond to some limitations of previous research and isolate the effects of age cohorts.FindingsThe results show differences in terms of some of the variables under study. Further, the effects of positive work-family interaction and PR on TOI were different from one age cohort to the other. The influence of meaning on the outcome variable was equal in Millennials and Xers but resulted positive.Research limitations/implicationsThe authors studied an under-researched population, used rigorous analytical procedures to simultaneously test the hypotheses across generations, analyzed data from a large sample size and control for confounding variables identified by researchers inquiring generational differences at the workplace. By these means, the study contributes to literature on millennial employees and age diversity.Originality/valueBy studying an under-reseach population and using suitable analytical techniques, the study contributes to literature on millennial employees and age diversity.
So similar and yet so different
Authors: Moretti Luca , Mayerl Martin , Muehlemann Samuel , Schlögl Peter , Wolter Stefan C. 
Published: January 2019

Purpose
The purpose of this paper is to compare a firm’s net cost and post-apprenticeship benefits of providing apprenticeship training in Austria and Switzerland: two countries with many similarities but some critical institutional differences.

Design/methodology/approach
The authors draw on detailed workplace data with information on the costs and benefits of apprenticeship training, as well as on hiring costs for skilled workers from the external labour market. The authors use nearest-neighbour matching models to compare Austrian firms with similar Swiss firms based on observable characteristics.

Findings
On average, a Swiss firm generates an annual net benefit of €3,400 from training an apprentice, whereas a firm in Austria incurs net costs of €4,200. The impetus for this difference is largely a higher relative apprentice pay in Austria. However, compared with Swiss firms, Austrian firms generate a higher post-training return by retaining a higher share of apprentices and savings on future hiring costs.

Practical implications
The authors demonstrate that apprenticeship systems can exist under different institutional environments. For countries currently in the process of establishing or expanding apprenticeship systems, the comparative analysis clearly shows that policymakers should consider more than just one country’s particular apprenticeship model.

Originality/value
The authors provide a first comparative analysis between two apprenticeship countries that empirically assesses a firm’s costs and benefits of training during an apprenticeship programme and also provides a monetary value of a particular type of post-training benefits that firms can generate by retaining former apprentices as skilled workers (i.e. savings in future hiring costs for skilled workers).
Happy feelings: examining music in the service environment
Authors: Kemp Elyria Angela , Williams Kim , Min Dong-Jun , Chen Han 
Published: January 2019

Purpose
The purpose of this paper is to examine the psychological influence that the presence of music has on consumers’ evaluations of the service environment. Specifically, it investigates how emotion regulation processes and the impact of emotions/mood are linked to consumers’ evaluation of service and product quality.

Design/methodology/approach
An exploratory study was conducted using industry professionals in order to garner insight about the value of music and its benefits in the service environment. A field experiment was then conducted to test hypotheses.

Findings
Industry professionals offer implicit theories about the value of music. Specifically, they propose that music can be used to help customers regulate emotions and improve mood, enhance the customer experience and help in attracting new consumer segments. Results from the field experiment found that those exposed to music were likely to improve mood, express more favorable evaluations of the service and product quality of the establishment, as well as exhibit stronger intentions to continue to patronize the establishment.

Practical implications
Using live music in the service environment can be beneficial to organizations by improving customers’ emotional/psychological status as well as their evaluation of the consumption experience.

Originality/value
This research contributes to the existing literature by demonstrating how emotion regulation processes and the impact of emotions/mood are linked to consumers’ evaluation of service and product quality. Also, support for mood congruency judgment is found. Participants in the field study who had been exposed to music indicated that they made efforts to improve their mood and subsequently had more favorable judgments of service and product quality.
Linking food safety training with whistle-blowing
Authors: Yu Heyao , A. Sirsat Sujata , Neal Jack A. 
Published: January 2019

PurposeThe purpose of this paper is to develop a validated food safety whistle-blowing scale and examine how training influences food handlers’ whistle-blowing, the mediating roles of job satisfaction and food safety self-efficacy and the moderating roles of organization type and gender.Design/methodology/approachA sample of 734 food handlers from the food service industry and 306 food handlers from the food processing industry were recruited. A two-step psychometric process was conducted to validate the scale, and a moderated mediation model was used to examine the mechanisms through which food safety training influences whistle-blowing.FindingsThe results showed that job satisfaction and self-efficacy fully mediated the relationship between training and whistle-blowing. Organization type moderated the first step of the two indirect paths and gender moderated the second step, thereby supporting the mediated-moderated model.Practical implicationsThe results indicate the influence of food safety training programs on whistle-blowing behaviors and suggest other methods of enhancing employee whistle-blowing through human resource management.Originality/valueA validated scale is lacking to measure whistle-blowing in the food safety context, and little research has examined the influence of human resource practices on whistle-blowing. This study provides meaningful insights for researchers by developing and validating food safety the whistle-blowing scale, connecting training with whistle-blowing, and provides useful information for practitioners by offering the methods of enhancing whistleblowing in both the food processing and food service industry.
Government institutional support, entrepreneurial orientation, strategic renewal, and firm performance in transitional China
Authors: Shu Chengli , De Clercq Dirk , Zhou Yunyue , Liu Cuijuan 
Published: January 2019

PurposeThe purpose of this paper is to examine how entrepreneurial orientation (EO) and strategic renewal (as a critical dimension of corporate entrepreneurship) might transmit government institutional support and thereby enhance firm performance in a transition economy.Design/methodology/approachMulti-respondent data were collected from 230 Chinese-based firms. The hypotheses were tested with structural equation modeling, in combination with a bias-corrected bootstrap method, to assess the significance of the theorized direct and indirect relationships.FindingsGovernment institutional support enhances EO and strategic renewal individually, yet EO also fully mediates the relationship between government institutional support and strategic renewal. Moreover, strategic renewal fully mediates the relationship between EO and firm financial performance, and it partially mediates the relationship between EO and firm reputation.Originality/valueThis study contributes to entrepreneurship literature by testing an organization-level model of entrepreneurial phenomena in established firms that identifies EO and strategic renewal as two distinct mechanisms through which government institutional support in a transition economy can enhance organizational effectiveness, which entails the firm’s financial performance and reputation. In doing so, this study provides an extended understanding of how EO and strategic renewal might influence a firm’s financial and nonfinancial outcomes in different ways.
The myth of sharing publicly as 21st century literacy
Authors: Schmier Stephanie 
Published: January 2019

PurposeThis paper highlights the fluidity with which youth make decisions about engaging with digital technologies including online social media. Specifically, the purpose of this paper is to explore the possibilities that literacy curriculum that centers digital technologies can have for students from immigrant communities through tracing the case of a Bangladeshi–American girl named Sabina.Design/methodology/approachGrounded in a transliteracies frame, this qualitative case study explores the digital literacy practices of youth in an urban public secondary school in the USA. Data collection included participant observation across various spaces including an eighth grade digital media studies class, school cafeteria and hallways, participants’ homes and online communities. Further data included formal interviews, informal conversations and digital and print artifact collection. Data were analyzed through the lenses of flow and space–time path.FindingsThe findings of this paper highlight how Sabina made space for social networking using digital technologies on her own terms as well as how the ways that she collaborated through the use of digital technologies created opportunities for her to be an active participant in her social worlds across home and school contexts.Originality/valueAnalyzing Sabina’s digital literacy practices across diverse social spaces offers insights for educators to create opportunities for diverse youth to leverage digital technologies to support skills such as collaboration and civic engagement, which have been identified as defining characteristics of twenty-first century literacies. This case points to the imperative for teachers to create connected learning classrooms that offer opportunities for youth to use digital technologies to support their efforts to make change in the world on their own terms.