bluuebunny/crossref_metadata_2025 huggingface dataset:
Data Modeling and Management in the Big Data Era
Authors: Krishnamoorthy Srikumar
Published: September 2020

CFX Inc, an e-commerce start-up based out of India, has built a large e-marketplace that allows sellers and buyers to transact online. The firm currently has 30,000 sellers and aims to have around 50,000 sellers by FY 2015–16. In order to provide best shopping experience to their growing customer base, the firm needs to collect, store and analyze different kinds of data and improve their customer shopping experience. It is in the process of identifying and designing suitable data management systems to sustain and manage their business growth. The management needs a concrete set of recommendations in terms of the nature of solution, choice of the database, a data model that suits CFX's requirements, cost-benefit trade-offs involved and implementation considerations.
Developing MIS for National Innovation Foundation: Choosing Process, Product and Vendor
Authors: Verma Sanjay , Sharma Priyanka
Published: September 2020

National Innovation Foundation (NIF) was a partner organization of the Honey Bee Network (HBN) which was a networked organization of individuals, innovators, farmers, scholars, academicians, policy makers, entrepreneurs and non-governmental organizations (NGOs). The HBN worked to create a network of grassroot innovators and acknowledged them by protecting their IPR. NIF was an autonomous body of the Department of Science and Technology (DST), Government of India, which provided institutional support to grassroot innovators, and facilitated the diffusion of traditional knowledge through various channels. NIF also handled filing patents and licensing of grassroot technology.
Women directors’ effect on firm value and performance: the case of REITs
Authors: Noguera Magdy
Published: September 2020

Purpose

The purpose of this paper is to assess the effect of women directors on US Real Estate Investment Trusts (REITs) value and performance.

Design/methodology/approach

Archival financial and board of director data for the 1999–2019 period are collected and analyzed using panel data regression analysis.

Findings

The main findings indicate that women directors’ presence renders a modest positive effect on REIT performance but only when they reach critical mass on REIT boards; and that women directors have no effect at all on REIT value. Additional findings indicate that women directors are more common on REIT boards after the enactment of the Sarbanes–Oxley Act but less common on boards in which the REIT founder is the chief executive officer.

Originality/value

To the best of the author’s knowledge, this is the first research on the effect of a gender diverse board on REIT value. It is also the first paper documenting a positive relationship between board gender diversity and REIT performance. This paper fills a research gap, as it is one of the few papers focused on gender diversity within the REITs board composition literature.
Volunteer choice of nonprofit organisation: an integrated framework
Authors: Mitchell Sarah-Louise , Clark Moira
Published: September 2020

Purpose

This paper aims to explore how volunteers choose one nonprofit organisation (NPO) rather than another. It identifies the drivers of choice, and the relationship between them, to enable NPOs to strengthen their volunteer recruitment.

Design/methodology/approach

A total of 51 service-delivery volunteers were interviewed, drawn from 5 leading NPOs. A laddering technique was used to understand the context in which the choice of organisation was made and the underlying personal needs and goals. The data was analysed using means-end chain (MEC) methodology to uncover the relationships between, and hierarchy of, the decision drivers.

Findings

Brand, cause, and role were found to be important in meeting personal needs and goals through volunteering. The paper makes three contributions. Firstly, it presents a clearer understanding of NPO choice through adopting an integrated theoretical perspective. Secondly, it identifies the decision-making process and key relationships between the attributes of the NPO, the consequences for the volunteer, and the connection to their personal needs. Finally, the study makes an important contribution to literature through presenting a new conceptual framework of volunteer decision-making in the nonprofit context to act as a catalyst for future research.

Research limitations/implications

This research is both impactful through, and limited by, its context selection: regular service-delivery volunteers from five NPOs within two causes. The paper presents a rich research stream to extend this understanding to other nonprofit stakeholders, other causes including medical volunteer, and smaller NPOs.

Practical implications

In an increasingly competitive nonprofit environment with a growing need to support the vulnerable in society, NPO sustainability is dependent on their ability to recruit new volunteers. NPOs compete not only with other organisations with similar causes but also those offering similar volunteering roles, and other uses of time to meet personal needs such as sport, career, or community. Understanding how volunteers make their choice of NPO rather than other uses of their time is of vital importance to make the most effective use of scarce marketing resources. This paper contributes to that practitioner understanding.

Originality/value

To the best of the authors’ knowledge, this study is the first to extend the understanding of generic motivations of volunteers to consider specific choice of NPO. Unlike previous literature, the authors bring together theory on brand, cause, and role with personal needs. The authors are also the first to apply MEC methodology to the nonprofit context to uncover the personal underlying, less salient reasons behind NPO choice and the relationship between them.
Alternative future images of Tehran: scenario-based analysis
Authors: Firoozpour Armin , Marzban Ehsan , Pourezzat Ali Asghar
Published: September 2020

Purpose

Thinking and deciding about the future of the city as a combination of complex and uncertain systems is extremely difficult. This complexity, uncertainty and difficulty will be increased when our thoughts and decisions address the city’s long-term future. Considering these issues, the need for future thinking and alternate thinking in the process of urban management and planning becomes even more necessary. The purpose of this paper is to identify and explain the alternate futures of Tehran.

Design/methodology/approach

For this purpose, this study have tried to study alternate future images of Tehran in an archetypal form of “growth, collapse, disciplined society and transformed society” using “Dator’s Four Generic Alternate Futures” method.

Findings

These alternate futures, after identifying their key trends and drivers, have been narrated in the form of four scenarios called: “capital business center,” “crossing the fate of ray,” “Tehran family” and “Tehran investigators.” Increasing the authority and responsibility of the local governance, modification of Tehran urban management model and development of voluntary cooperation and democratic participation, are among the policy recommendations made on the basis of these images.

Originality/value

Achieving these images in parallel with identifying the most important challenges and opportunities in alternate futures will provide the basis for policy-making in Tehran’s future urban governance. It can be a creative model for developing future images for other cities.
Gender diversity, corporate governance and financial risk disclosure in the UK
Authors: Bufarwa Idris M. , Elamer Ahmed A. , Ntim Collins G. , AlHares Aws
Published: September 2020

Purpose

This study aims to investigate the impact of corporate governance (CG) mechanisms on financial risk reporting in the UK.

Design/methodology/approach

The study uses a panel data of 50 non-financial firms belonging to 10 industrial sectors listed on the London Stock Exchange in the period 2011-2015. Multivariate regression techniques are used to examine the relationships.

Findings

The findings of this study reveal that CG has a significant influence on financial risk disclosure. Specifically, it is found that block ownership and board gender diversity have a positive effect on the level of corporate financial risk disclosure (FRD). While there is no significant relationship between board size and corporate FRD.

Research limitations/implications

This study has significant implications for policy-makers, investors and regulators. Evidence of growing FRD implies that efforts by several stakeholders have had some positive impact on the level of FRD in the firms examined. Examples of such changes include, namely, increasing board size and gender diversity acting as effective firm level advisors and monitors of FRD. As a consequence, regulators and policymakers should continually pursue reforms to encourage firms to follow CG principles that are promoted as good practice.

Originality/value

This study adds to the emerging body of literature on CG–risk disclosure relationships in the UK context using content analysis. The study also highlights that gender diversity enhances FRD.
A moderated mediation model of employee experienced diversity management: openness to experience, perceived visible diversity discrimination and job satisfaction
Authors: Alam Mohammad Shahin , Shin DuckJung
Published: September 2020

Purpose

This study developed and tested a moderated mediation model on workplace diversity management. The analysis examined whether diversity management affects job satisfaction via perceived discrimination, depending on employees' openness to experience.

Design/methodology/approach

Building upon the assumptions of social identity theory, social cognitive theory and Big-Five theory, this study proposed and tested a model that analyzes the process through which diversity management influences perceived visible diversity discrimination and job satisfaction, depending on employees' openness to experience.

Findings

This study found support for the proposed moderated mediation model, which suggests that diversity management interacts with employees' openness to experience personality to influence their job satisfaction through perceived visible diversity discrimination. The results indicated that diversity management increased employees' job satisfaction in the workplace and that the relationship between diversity management and job satisfaction was further mediated by employees' perceptions of being discriminated against because of their age, gender and racial identities. The effect of diversity management on job satisfaction through perceived visible diversity discrimination was stronger when employees had high levels of openness to experience.

Practical implications

The results of the study suggest that the diversity management is an important organizational intervention to improve job satisfaction by providing a scientific explanation of its underlying psychological process and identifying the factors associated with the process, such as personality and perception of being discriminated.

Originality/value

This study contributes to extend the diversity management literature by applying the assumptions of social identity theory, social cognitive theory and Big-Five theory together to identify the relationship between diversity management and job satisfaction and the effect of perceived discrimination and openness to experience in the relationship.
Intellectual capital of SMEs in Thailand: an employee behavioural measurement instrument
Authors: Na-Nan Khahan , Kanthong Suteeluck N. , Khummueng Kattikamat , Dhienhirun Auemporn
Published: September 2020

Purpose

Intellectual capital (IC) is an important factor to push and drive organisations to achieve competitive advantages and growth. This study aims to develop and test an instrument to measure IC for employee behaviour in the context of small and medium-sized enterprises (SMEs).

Design/methodology/approach

The measurement instrument was designed after assessing literature reviews on IC that provided a strong theoretical support for application of a specific set of items in the SME context. Instrument validity and reliability were tested for item-objective congruence by five experts. The results ranged between 0.8 and 1.0, with a reliability coefficient of 0.950. Exploratory factor analysis and confirmatory factor analysis were used to confirm construct validity between theoretical and empirical evidence. Data were collected from 240 hairdressers employed by SMEs in Thailand.

Findings

The results revealed that IC can be classified into two groups as human capital and relational capital. Constructs between theoretical concepts and empirical evidence gave values of χ2 = 42.336, df = 35, p = 0.184, χ2/df = 1.210, GFI = 0.972, AGFI = 0.938, RMSEA = 0.030 and SRMR = 0.018.

Research limitations/implications

Empirical findings were derived from a sample of 240 hairdressers. However, validation and reliability of the instruments require confirmation in various other contexts with a larger number of samples. This cross-sectional study identified the effects of IC in SMEs, thereby contributing to the ongoing debate regarding the determinants of research performance.

Originality/value

The IC instrument was determined as valid and fulfilled the knowledge gap concerning SMEs by facilitating future studies on boundaries with IC assessment spanning SME contexts. This instrumental support will assist researchers and academics to develop a more comprehensive understanding of IC and explore its potential in future research areas.
Towards energy transition at the Faculty of Education of Bilbao (UPV/EHU): diagnosing community and building
Authors: Ortega Lasuen Unai , Ortuzar Iragorri Maria Arritokieta , Diez Jose Ramon
Published: September 2020

Purpose

This paper aims to present the results of a study aimed at performing a first diagnosis of energy literacy and energy use in a Faculty of Education, by means of identifying energy consumption patterns, as well as energy literacy and commitments regarding energy transition. This diagnosis is the basis for establishing the foundations of a path toward energy transition in the faculty and further designing energy saving and education strategies.

Design/methodology/approach

Quantitative and qualitative data were collected in a mixed-method approach. A survey was arranged to assess the attitudes, habits and knowledge regarding the current energy system within the community of the Faculty (407 responses). Comparisons among the main collectives that make up the community were performed, i.e. students, teaching and research staff and management and services staff. In parallel, the general electric consumption of the faculty was monitored. The results of these diagnostics were presented at several forums and workshops on energy transition held in the faculty where personal commitments in favor of energy transition were gathered and further categorized (105 initiatives).

Findings

Positive attitudes toward energy saving were observed, reflecting in different generic habits. Additionally, some belief or hope for a technological solution for current and future energy problems was detected, as well as a lower level of implication or commitment when specifying personal attitudes. Similarly, widespread ignorance of the current energy context was revealed, regarding both the energy system and household energy consumption. Concerning the undertaking of personal commitments, low impact energy saving habits prevailed, and knowledge was not identified as being a necessary element of energy saving education in attitudes and habits.

Practical implications

This research provides relevant information for the design of educational interventions to promote energy literacy in higher education institutions.

Originality/value

The survey provides valuable insights regarding future educators’ and their current teachers’ energy literacy in a challenging energy context. The lack of general knowledge about the energy context in the community, together with the limited impact of the commitments gathered among students, stresses the need for integration of basic energy contents, both within education degrees and the management strategy of the faculty.
The impact of political instability driven by the Tunisian revolution on the relationship between Google search queries index and financial market dynamics
Authors: Trichilli Yousra , Abbes Mouna Boujelbène , Zouari Sabrine
Published: September 2020

Purpose

This paper examines the impact of political instability on the investors' behavior, measured by Google search queries, and on the dynamics of stock market returns.

Design/methodology/approach

First, by using the DCC-GARCH model, the authors examine the effect of investor sentiment on the Tunisian stock market return. Second, the authors employ the fully modified dynamic ordinary least square method (FMOL) to estimate the long-term relationship between investor sentiment and Tunisian stock market return. Finally, the authors use the wavelet coherence model to test the co-movement between investor sentiment measured by Google Trends and Tunisian stock market return.

Findings

Using the dynamic conditional correlation (DCC), the authors find that Google search queries index has the ability to reflect political events especially the Tunisian revolution. In addition, empirical results of fully modified ordinary least square (FMOLS) method reveal that Google search queries index has a slightly higher effect on Tunindex return after the Tunisian revolution than before this revolution. Furthermore, by employing wavelet coherence model, the authors find strong comovement between Google search queries index and return index during the period of the Tunisian revolution political instability. Moreover, in the frequency domain, strong coherence can be found in less than four months and in 16–32 months during the Tunisian revolution which show that the Google search queries measure was leading over Tunindex return. In fact, wavelet coherence analysis confirms the result of DCC that Google search queries index has the ability to detect the behavior of Tunisian investors especially during the period of political instability.

Research limitations/implications

This study provides empirical evidence to portfolio managers that may use Google search queries index as a robust measure of investor's sentiment to select a suitable investment and to make an optimal investments decisions.

Originality/value

The important research question of how political instability affects stock market dynamics has been neglected by scholars. This paper attempts principally to fill this void by investigating the time-varying interactions between market returns, volatility and Google search based index, especially during Tunisian revolution.
Halal food export and Malaysia’s potential: the applicability of the gravity theory of trade
Authors: Ali Md. Yunus , Abdul Ghaffar Puteri Zahrah Aminan , Kabir Shahriar , Munir Sa'adiah
Published: September 2020

Purpose

The gravity theory of trade explains the potential for trade between nations, but its application to trade in halal food has been questioned by previous studies. This study aims to investigate this issue and the role of trading partners’ economic strength and their distance from one another to identify Malaysia’s potential to export food to key halal markets.

Design/methodology/approach

The gravity theory of trade was used to examine Malaysia’s top 10 food exports to key halal markets from 2000–2017. The gravity panels were estimated using the Hausman-Taylor modelling technique to control for endogeneity within the model.

Findings

The application of the gravity theory of trade to a halal market context provides mixed results. Although the high economic strength (gross domestic product) of the trading partners enhances halal trade, the distance between the partners does not affect the volume of halal food exports. Moreover, the study identifies Malaysia’s potential to export only a few food commodities to key halal markets.

Originality/value

This study challenges the applicability of the gravity theory of trade to the halal food market. The study extends the model with additional controls for behavioural aspects and applies it to commodity-specific segregated trade in halal food. The findings underscore the need to extend the theory beyond its current focus when explaining trade opportunities in halal markets.
Destination branding and co-creation: a service ecosystem perspective
Authors: Giannopoulos Antonios , Piha Lamprini , Skourtis George
Published: September 2020

Purpose

Drawing on the service-dominant logic and the institutional theory, this paper aims to explore the value-creating mechanisms of branding in the destination context and the brand co-creation process at and between different levels of a service ecosystem.

Design/methodology/approach

An exploratory research design was used to generate qualitative data from 18 in-depth interviews with important stakeholders and investigate how and why brand co-creation is fostered in the service ecosystem.

Findings

The study proposes a stepwise process of strategic imperatives for brand co-creation in the destination context. It presents the multi-directional flows of the brand meaning across levels of the tourism ecosystem and thereby interprets stakeholders’ efforts to co-create sustainable brands that gain prominence in the global tourism arena.

Research limitations/implications

Future research might validate the framework in a quantitative research setting. The extended analysis of the value-creating ecosystem could investigate the role of institutions and brand value propositions across levels.

Practical implications

Acknowledging their limited control over the brand co-creation process, tourism practitioners are offered step-by-step guidance to help shape a destination brand that may retain relevance in the tourists’ minds. Critical insights are provided into resource sharing between actors and subsequent responsibilities for a sustainable destination branding strategy.

Originality/value

The paper considers the significance of the various levels in the ecosystem and the underlying mechanisms of brand co-creation in a somewhat neglected branding domain.
The social impact of the 2016 Rio Olympic Games: comparison of residents' pre- and post-event perceptions
Authors: Ribeiro Tiago , Correia Abel , Biscaia Rui
Published: September 2020

Purpose

Despite the recognition that citizens' perceptions of mega sport events' social impact is critical for the sustainable development of these events and host cities, most previous studies have not taken into consideration how these perceptions may change over time. This study examines citizens' social impact perceptions of the 2016 Rio Olympic Games before and after the event.

Design/methodology/approach

Data were collected amongst local residents of Rio de Janeiro pre- and post-event (n = 256). A confirmatory factor analysis (CFA) analysed the psychometric properties of the proposed social impact constructs. Subsequently, a multigroup analysis and latent mean comparisons were conducted to test social impact perceptions pre- and post-event.

Findings

The multigroup CFA showed factorial stability of the social impact model in both periods, while the latent mean comparisons revealed significant differences in the dimensions of social experiences, city image and community pride enhancement, public infrastructures and social conflicts. Results indicated that the perception of positive impacts tends to increase, while perceived negative impacts decrease from pre- to post-event.

Social implications

The social effects of hosting sport mega events result in a short-term change in attitudes towards the local community, leading to a better comprehension on how communities perceive the event's impact on their lives.

Originality/value

In a highly complex mega event such as the Olympic Games, any change may influence residents' perceptions. The findings of this study demonstrate the importance of residents for determining support or opposition in hosting the event, allowing a better understanding of the exchange effects.
Technology usage, intellectual capital, firm performance and employee satisfaction: the accountants' idea
Authors: Torre Carlo , Tommasetti Aurelio , Maione Gennaro
Published: September 2020

Purpose

The paper proposes a conceptual integration between two variables, both considered as capable of affecting public firm performance: technology and intellectual capital.

Design/methodology/approach

The analysis is performed by testing a structural equation model (SEM) which allows to measure simultaneously a plurality of variables, highlighting all the possible connections. Data is collected by administering more than 500 paper questionnaires to accountants working within Local Health Firms of Naples and Salerno.

Findings

The study seems to align with the considerations according to which intellectual capital expressed through its three dimensions – relational capital, human capital and organizational capital – exert a positive influence on perceived performance of healthcare firms, ultimately impacting on the Employees' Satisfaction.

Research limitations/implications

The study acts as a useful guide from a managerial point of view, because it may support firm decision-making. In fact, public sector managers can leverage an instrument capable of activating functional mechanisms to improve firm performance.

Originality/value

The work allows overcoming the literature gap due to the fact that, although there is a wide recognition of the potential of technology and intellectual capital, there are no studies that synergistically integrate both the aspects in the attempt to understand their value in terms of influence on the performance of public firms, on the one hand, and on employees' satisfaction, on the other. In this vein, the work, in an attempt to provide further scientific support to the link between technology and intellectual capital, is a tool capable of highlighting how this link positively impacts on company performance and employee satisfaction.
Scalable and robust latent trajectory class analysis using artificial likelihood
Authors: Hart Kari R. , Fei Teng , Hanfelt John J.
Published: September 2020

Latent trajectory class analysis is a powerful technique to elucidate the structure underlying population heterogeneity. The standard approach relies on fully parametric modeling and is computationally impractical when the data include a large collection of non‐Gaussian longitudinal features. We introduce a new approach, the first based on artificial likelihood concepts, that avoids undue modeling assumptions and is computationally tractable. We show that this new method provides reliable estimates of the underlying population structure and is from 20 to 200 times faster than conventional methods when the longitudinal features are non‐Gaussian. We apply the approach to explore subgroups among research participants in the early stages of neurodegeneration.
Intergenerational mobility in education: Is Africa different?
Authors: Azomahou Théophile T. , Yitbarek Eleni
Published: September 2020

This study analyzes the intergenerational transmission of education in nine Sub‐Saharan African countries, using nationally representative household survey data on parents of adult individuals. It provides the levels and trends of intergenerational persistence of years of schooling over 50 years, and it also ranks the nine countries relative to other nations. There is a declining cohort trend in the intergenerational persistence of education, particularly after the 1960s. Nevertheless, the education of parents remains a strong determinant of the educational outcomes of children. The analysis also documents country heterogeneity (intergenerational educational mobility varies significantly across countries) and a marked gender effect: daughter's education attainment is more correlated with her parents' education than that of sons. From a policy perspective, our result points to the importance of targeted redistributive policies and the expansion of secondary education to improve mobility.
CERS6 required for cell migration and metastasis in lung cancer
Authors: Suzuki Motoshi , Cao Ke , Kato Seiichi , Mizutani Naoki , Tanaka Kouji , Arima Chinatsu , Tai Mei Chee , Nakatani Norie , Yanagisawa Kiyoshi , Takeuchi Toshiyuki , Shi Hanxiao , Mizutani Yasuyoshi , Niimi Atsuko , Taniguchi Tetsuo , Fukui Takayuki , Yokoi Kohei , Wakahara Keiko , Hasegawa Yoshinori , Mizutani Yukiko , Iwaki Soichiro , Fujii Satoshi , Satou Akira , Tamiya‐Koizumi Keiko , Murate Takashi , Kyogashima Mamoru , Tomida Shuta , Takahashi Takashi
Published: September 2020

Sphingolipids constitute a class of bio‐reactive molecules that transmit signals and exhibit a variety of physical properties in various cell types, though their functions in cancer pathogenesis have yet to be elucidated. Analyses of gene expression profiles of clinical specimens and a panel of cell lines revealed that the ceramide synthase gene CERS6 was overexpressed in non–small‐cell lung cancer (NSCLC) tissues, while elevated expression was shown to be associated with poor prognosis and lymph node metastasis. NSCLC profile and in vitro luciferase analysis results suggested that CERS6 overexpression is promoted, at least in part, by reduced miR‐101 expression. Under a reduced CERS6 expression condition, the ceramide profile became altered, which was determined to be associated with decreased cell migration and invasion activities in vitro. Furthermore, CERS6 knockdown suppressed RAC1‐positive lamellipodia/ruffling formation and attenuated lung metastasis efficiency in mice, while forced expression of CERS6 resulted in an opposite phenotype in examined cell lines. Based on these findings, we consider that ceramide synthesis by CERS6 has important roles in lung cancer migration and metastasis.
‘The Hidden Holocaust’: The East Timor Alert Network (ETAN) and Human Rights Claims in Canada, 1985–1998
Authors: Torelli Julian
Published: September 2020

This article examines the East Timor Alert Network's (ETAN) claims‐making strategies regarding support for human rights and self‐determination of East Timor during the Indonesian occupation from 1975–1998. This research seeks to understand how ETAN attempted to persuade Canadians to care about a geographically distant horror. I examine various claims‐making strategies that ETAN used to encourage Canadian audiences to evaluate the problem as an object of public concern, the Timorese as victims deserving of their sympathy, and Canadian government as condemnation‐worthy.
Insomnia symptoms and non‐suicidal self‐injury in adolescence: understanding temporal relations and mechanisms
Authors: Latina Delia , Bauducco Serena , Tilton‐Weaver Lauree
Published: September 2020

We propose a theoretical model of insomnia symptoms and non‐suicidal self‐injury (NSSI) that posits bidirectional linkages. We hypothesised that heightened depressive symptoms and impulsivity that result from insomnia increase NSSI. We also posit that the shame associated with NSSI triggers repetitive negative thinking, in turn increasing insomnia. Using three longitudinal waves of questionnaire data collected annually from a sample of Swedish adolescents (n = 1,457; Mage = 13.2, SD = 0.43; 52.7% boys), we assessed the mediating role of depressive symptoms, impulsivity, rumination, and worry on the link between insomnia and NSSI. After controlling for depressive symptoms, we found that insomnia was related to increases in NSSI from the second to the third time point (ß23 = 0.09, p = .01). NSSI was consistently related to increased insomnia (ß12 = 0.09, p = .01; ß23 = 0.11, p < .001). In addition, depressive symptoms (ßind = 0.01, p = .02), but not impulsivity (ßind = 0.01, p = .09), mediated the path from insomnia to increased NSSI. Neither worry (ßind = 0.00, p = .59) nor rumination (ßind = 0.00, p = .96) mediated the link between NSSI and increased insomnia. We conclude that NSSI and insomnia maintain each other over time. Thus, screening adolescents for insomnia symptoms may help identify those at risk of NSSI. Although depression seems to explain why insomnia is a risk factor for NSSI, further studies should investigate why NSSI plays a role in the maintenance of insomnia. This understanding will lay the foundation for intervention.
Targeting epicardial adipose tissue with exercise, diet, bariatric surgery or pharmaceutical interventions: A systematic review and meta‐analysis
Authors: Launbo Natja , Zobel Emilie H. , von Scholten Bernt Johan , Færch Kristine , Jørgensen Peter G. , Christensen Regitse H.
Published: September 2020

Epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) are metabolically active fat depots implicated in cardiovascular disease, and EAT has potential as a novel cardiac risk factor, suitable as a target for interventions. The objective of this systematic review and meta‐analysis was to investigate the evidence whether EAT and PAT volume can be reduced by weight‐loss interventions (exercise, diet, bariatric surgery or pharmaceutical interventions). A systematic literature search identified 34 studies that were included in the qualitative synthesis (exercise, n = 10, diet, n = 5, bariatric surgery, n = 9 and pharmaceutical interventions, n = 10). Of the 34 studies, 10 reported sufficient data to be included in the meta‐analysis. The meta‐analysis was only conducted for changes in EAT volume, since only few controlled studies reported changes in PAT (n = 3) or total cardiac adipose tissue volume (n = 1). A significant pooled effect size (ES) for reduction in EAT volume was observed following weight‐loss interventions as compared with control interventions (ES = −0.89, 95% CI: −1.23 to −0.55, P < 0.001). When comparing the effect of exercise training versus control on EAT volume reduction, there was a significant pooled ES favouring exercise training (ES: −1.11, 95% CI: −1.57 to −0.65, P < 0.001). Similarly, the ES of pharmaceutical versus control interventions on EAT volume reduction was significant, favouring pharmaceutical interventions (ES: −0.79, 95% CI: −1.37 to −0.21, P < 0.0072). In conclusion, this systematic review and meta‐analysis provides evidence that exercise, diet, bariatric surgery and pharmaceutical interventions can reduce cardiac adipose tissue volume.
Internal carotid and brachial artery shear‐dependent vasodilator function in young healthy humans
Authors: Carr Jay M. J. R. , Hoiland Ryan L. , Caldwell Hannah G. , Coombs Geoff B. , Howe Connor A. , Tremblay Joshua C. , Green Daniel J. , Ainslie Philip N.
Published: September 2020

Key points

Brachial artery (BA) shear‐mediated dilatation is a widely used assessment of vascular function with links to coronary artery health and cardiovascular risk.

Cerebral vascular health is often interrogated using cerebrovascular (middle cerebral artery velocity) reactivity to carbon dioxide.

We show that endothelium‐dependent diameter (dilator) responses are not significantly related between the internal carotid artery (ICA) and BA; nor are endothelium‐independent responses.

Additionally, ICA endothelium‐dependent responses are not related to middle cerebral artery velocity or ICA blood flow reactivity responses to carbon dioxide.

Therefore, assessment of large extracranial cerebral artery vascular health should be quantified via methods specific to the vessel, not via peripheral endothelial function or cerebrovascular reactivity to carbon dioxide.

This study compared internal carotid artery (ICA) and brachial artery (BA) endothelium‐dependent and ‐independent vasodilation. We hypothesized that endothelium‐dependent and ‐independent vasodilation of the ICA and BA would be neither similar in magnitude nor correlated between vessels. In 19 healthy adults (23 ± 6 years, 24 ± 3 kg/m2, six female), endothelium‐dependent dilatation in the ICA was determined via Duplex ultrasound during transiently elevated shear stress caused by increased partial pressure of end‐tidal carbon dioxide using dynamic end‐tidal forcing (+9 mmHg; cerebral flow‐mediated dilatation, cFMD). BA endothelium‐dependent dilatation was assessed via standard flow‐mediated dilatation (FMD). Endothelium‐independent dilatation in the ICA and BA was assessed concurrently for 10 min following administration of 400 µg sublingual glyceryl trinitrate (GTN). Endothelium‐dependent vasodilation of the ICA (3.4 ± 2.4%) was lower than (P = 0.013) and not correlated to that of the BA (7.9 ± 3.3%; r2 = 0.00, P = 0.93). Including baseline diameter and shear‐rate area under the curve as covariates maintained the difference between cFMD and FMD (3.3 ± 4.2% vs. 7.8 ± 3.8%, P = 0.03), while including baseline diameter and baseline shear rate‐adjusted area under the curve as covariates abolished it (5.9 ± 3.7% vs. 5.9.8 ± 3.5%, P = 0.99). GTN‐mediated vasodilation of the ICA (14.3 ± 2.9%) was lower than (P = 0.002) and not correlated to that of the BA (25.5 ± 8.8%; r2 = 0.12, P = 0.19). Adjusting for baseline diameter eliminated the differences in GTN‐induced vasodilation (ICA: 20.1 ± 5.8% vs. BA: 20.4 ± 5.5%; P = 0.93). Differences in endothelium‐dependent responses, and the lack of correlations between arteries, indicates that endothelium‐dependent function cannot be assumed to be related across cerebral and peripheral vasculatures in young, healthy humans.
Study on Electromagnetic Heating Process of Wind Power Gear: Temperature Morphology and Evolution
Authors: Wen Huaiyu , Han Yi , Zhang Xiaobo , Liu Feng , Zhang Hongwang
Published: September 2020

As a key component of wind turbine, the surface strengthening treatment of wind turbine gear is crucial to enhance its performance and service life. In the process of tooth-by-tooth induction heating, clear temperature distribution and process evolution could realize the lean control of heating effect and quality. In this article, the tooth-by-tooth heating process under the v-shaped inductor was studied to analyze the temperature field morphology and its evolution process. The results show that in the tooth profile region, the boundary morphology of the temperature field near the central section of the heating region conforms to the Boltzmann function, while the far sections conform to the normal distribution. At the end of heating, from the surface to the depth of the heating layer and from the heating center to both sides, both the maximum temperature difference and the distribution temperature are reduced. Meanwhile, the maximum temperature point near the central section is offset during the evolution of the temperature field morphology. The change of physical properties of materials and induced eddy distribution caused by involute structure and the constant change of temperature gradient are the fundamental reasons for the appearance of nonuniform temperature field and temperature excursion. The spatiotemporal variation of the hottest point was found, and the temperature morphology and evolution were revealed, which would provide a theoretical basis for adjusting the temperature distribution of tooth profile according to the requirements of different heating layers.
Brittle Crack Arrestability and Inverse Fracture in DWTT
Authors: Sakimoto Takahiro , Amano Toshihiko , Hiraide Takashi , Tagawa Tetsuya , Igi Satoshi , Shinohara Yasuhiro
Published: September 2020

The drop-weight tear test (DWTT) has been widely used to evaluate the resistance of linepipe steels against brittle crack propagation, and the shear area fraction SA% in the DWTT has been adopted in the requirement for the linepipe steels. However, recent studies have pointed out the issue of ambiguity in evaluation of the DWTT when a ductile crack initiates from the notch and then transits to a brittle crack during ductile crack propagation. This fracture behavior is termed “inverse fracture.” According to the API Recommended Practice 5L3 (API RP 5L3), a test is considered invalid when a DWTT specimen shows inverse fracture. In this case, it is difficult to examine the acceptance criterion (85% shear area transition temperature) for linepipe steels. Because the purpose of the DWTT is to evaluate the brittle crack arrestability of the steels in a pressurized linepipe, the DWTT results should be examined with a propagating brittle crack arrest test. A large-scale brittle crack arrest test called the West Jefferson test is generally conducted to reproduce the crack propagation and arrest behavior in actual linepipes. However, it is somewhat difficult to control the lower test temperature and to initiate brittle crack in recent high-toughness steels in this burst test. Although the test stress conditions of the uniaxial tension in the plate tension brittle crack arrest test and the biaxial tension in a pressurized pipe are different, the plate tension brittle crack arrest test has the advantages of accurate control of the test temperature, test stress, and brittle crack initiation in comparison with the actual pipe burst test. Therefore, in this study, the brittle crack arrestability of linepipe steel which showed inverse fracture in the DWTT was investigated by conducting plate tension brittle crack arrest tests under an isothermal condition (crack arrest temperature test (CAT test)), which simulates the condition of the actual pipelines in service. This study also investigated the local shear lip thickness fraction in the CAT tests together with the shear area fraction SA% measured in DWTTs. Based on the results, the effect of brittle crack arrestability on inverse fracture appearance in the DWTTs was discussed in comparison with the brittle crack arrest behavior in the CAT tests.
Surface Textured Drill Tools—An Effective Approach for Minimizing Chip Evacuation Force and Burr Formation During High Aspect Ratio Machining of Titanium Alloy
Authors: Niketh S. , Samuel G. L.
Published: September 2020

The real challenge pertaining to high aspect ratio drilling is the rapid increase in chip evacuation force due to the chip clogging phenomenon occurring at higher drilling depths. The clogged chips will further impede the reachability of cutting fluid at the machining zone leading to the tool temperature buildup. This will eventually result in the catastrophic failure of the tool. Hence, in the present work, an attempt has been made to minimize the chip evacuation force by functionalizing the drill tool surfaces based on the laser microtexturing principle. Microscale textures in the form of circular dimples were created on the flute and margin side of the drill tool with an objective to control the sliding friction, thereby minimizing the chip clogging effect. The effectiveness of the functionalized drill tools were assessed mainly based on the variation in thrust force and torque. Drilling experiments showed a net reduction of 17.18% in thrust force and 26.98% in torque while machining Ti–6Al–4V using the flute and margin textured tool, which justified the effectiveness of micro scale textures in minimizing the chip evacuation forces. The experimental analysis was further extended in terms of burr height evaluation, where FMT tools were found to be highly effective in burr height reduction (1.29 mm), showing a net reduction of 54.26% when compared with the non-textured tool. The outcomes from this research work will be highly beneficial for the manufacturing industries including aerospace, automobile, and spacecraft as high aspect ratio drilling of titanium alloys are still categorized to be the most challenging machining process owing to its lower thermal conductive property.
Dynamic Metal Transfer Behavior in Double-Wire DP-GMAW of Aluminum Alloy Under Different Pulse Phases
Authors: Wu Kaiyuan , Zhan Jiatong , Cao Xuanwei , Hong Xiaobin , Xie Peimin
Published: September 2020

The effects of pulse phase and pulse stage on the metal transfer characteristics in double-wire double pulse gas metal arc welding (DP-GMAW) of aluminum (Al) alloy were studied using high-speed camera images and current and voltage waveforms. In addition, the effects of various forces on dynamic metal transfer behavior were analyzed under different pulse phases and pulse stages. The results show that the spray transfer mode can be obtained in both the alternating pulse phase (APP) and synchronous pulse phase (SPP). The transfer pattern of the leading and trailing droplets is alternating in the APP, but changes to simultaneous metal transfer in the SPP, mainly owing to influence of the pulse phase on droplet growth. The transfer type is one drop double pulse (ODDP) during the strong pulse stage and one drop triple pulse (ODTP) during the weak pulse stage, regardless of the pulse phase. The pulse phase does, however, affect the Lorentz force between the leading and trailing droplets, causing droplet collision in the SPP, which results in a poorer weld bead appearance compared with in the APP. Finally, the droplet diameter was found to be similar during different pulse phases and pulse stages.
Electrical characterization of Si-doped conductive AlInN films grown nearly lattice-matched to c-plane GaN on sapphire by metalorganic chemical vapor deposition
Authors: Miyoshi Makoto , Nakabayashi Taiki , Yamanaka Mizuki , Egawa Takashi , Takeuchi Tetsuya
Published: September 2020

In this study, Si-doped conductive AlInN films with a thickness of 300 nm were grown nearly lattice-matched to c-plane GaN-on-sapphire templates by metalorganic chemical vapor deposition. A high net donor concentration of approximately 1 × 1019 cm−3 was observed for a highly Si-doped AlInN film. To evaluate its vertical-direction electrical resistivity without being affected by polarization-induced carriers, the transfer length measurement (TLM) model was applied to two kinds of test element groups. By analyzing the TLM results, the vertical-direction resistivity of the 300-nm-thick n-type AlInN film was estimated to be 5.8 × 10−4 Ω cm2.
Extreme-ultraviolet-induced carbon growth at contaminant pressures between 10−10 and 10−6 mbar: Experiment and model
Authors: Hill Shannon B. , Tarrio Charles , Berg Robert F. , Lucatorto Thomas B.
Published: September 2020

Carbon contamination induced by ultraviolet (UV) radiation affects precision optics in applications as diverse as semiconductor lithography and satellite observations of the Sun. Our previous experiments have shown that low-intensity UV-induced surface contamination depends quasilogarithmically on the partial pressure of the organic contaminant due to the polydispersive nature of the surface-adsorbate system. This complex dependence presents difficulties because, without a physically motivated model, it cannot be extrapolated to low pressures. We present measurements and a model of carbon growth induced by UV exposure in the presence of tetradecane vapor. The model, which includes a coverage-dependent adsorption energy, describes the measurements over four orders of magnitude in pressure, and we expect that it can be extrapolated to the lower pressures of interest to the extreme ultraviolet lithography and solar astronomy communities. Our experience with other contaminants leads us to expect that other organic contaminants will behave similar to tetradecane. The results also provide insights into the kinetics governing coverage isotherms at extremely low partial pressures.
Experimental study of nonlinear acoustic impedance of circular orifices
Authors: Komkin Alexandr , Bykov Aleksei , Mironov Mikhail
Published: September 2020

The results of experimental studies of the acoustic impedance of orifices in the plate in the impedance tube, using the transfer functions method in a wide range of sound pressure levels, are presented. Dependencies of the orifice impedance on its diameter in nonlinear regimes are obtained. It is established that in order to obtain reliable estimates of the orifice impedance, the particle velocity in the orifice should be determined by measurements. It is shown that the diameter of the orifice does not affect its acoustic impedance in the developed nonlinearity regimes. This impedance depends only on the particle velocity in the orifice, and this dependence is nonlinear.