bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of model bias in predicting volatility: evidence from the US equity markets
Authors: Li Yan , Luo Lian , Liang Chao , Ma Feng
Published: October 2020

Purpose

The purpose of this paper is to explore whether the out-of-sample model bias plays an important role in predicting volatility.

Design/methodology/approach

Under the heterogeneous autoregressive realized volatility (HAR-RV) framework, we analyze the predictive power of out-of-sample model bias for the realized volatility (RV) of the Dow Jones Industrial Average (DJI) and the S&P 500 (SPX) indices from in-sample and out-of-sample perspectives respectively.

Findings

The in-sample results reveal that the prediction model including the model bias can obtain biggerR2, and the out-of-sample empirical results based on several evaluation methods suggest that the prediction model incorporating model bias can improve forecast accuracy for the RV of the DJI and the SPX indices. That is, model bias can enhance the predictability of original HAR family models.

Originality/value

The author introduce out-of-sample model bias into HAR family models to enhance model capability in predicting realized volatility.
The path of support-to-sales: mediating role of seller collaborative information exchange in social commerce
Authors: Chen Li , Zhu Fengxia , Mantrala Murali
Published: October 2020

Purpose

This paper aims to systematically investigate the direct and indirect effects of four types of support – peer instrumental support, peer emotional support, platform business support and platform communication support – on seller trade volume in social commerce. It also aims to uncover the path of support-to-sales of the seller from a platform perspective and provides a more complete picture of the social commerce phenomenon.

Design/methodology/approach

This paper uses multi-source data including primary survey data and secondary data on trade volume to test the hypotheses. PROCESS mediation model is used to analyze the multi-source data set.

Findings

This study finds that the positive effects of peer instrumental support, platform business support and platform communication support on seller trade volume are fully mediated by seller collaborative information exchange. Also, peer emotional support has a significant negative effect on seller trade volume and collaborative information exchange can serve as a buffer to mitigate the negative effect.

Research limitations/implications

The authors provide new insights into what types of support are or are not conducive to improving transaction volume of individual sellers and highlight the mediating role of seller information exchange in this value generation process in social commerce. These findings advance current knowledge of how seller interactions increase value in social commerce. The chosen research setting may limit the generalizability of the findings of this study.

Practical implications

This paper offers valuable implications for social commerce platforms on how to better serve their sellers to achieve high growth. Specifically, the findings suggest that platforms should encourage instrumental support and information exchange among peer sellers. In addition, platforms should expand seller support from a single-focus on sellers’ business to a dual-focus on both sellers’ business and socialization in social commerce.

Originality/value

This paper fulfills an identified need to study how sellers can better derive value from the social interactions and how social commerce platforms can effectively influence transactions, support sales and serve as a selling platform.
Tempered radicalism as an approach to revisiting indigenous forms of critical human resource development
Authors: Osafo Emmanuel , Yawson Robert Mayfield
Published: October 2020

Purpose

The purpose of this study is to present a conceptual framework to guide the design, development, implementation and evaluation of education and human resource development (HRD) efforts in Ghana.

Design/methodology/approach

This paper draws on the concept of a tempered radical approach to provide a framework for a critical HRD (CHRD) and explore ways by which this view can contribute to developing HR who possess the requisite tools and character to function efficiently in the 21st century and beyond. This paper followed a multidisciplinary integrated literature review approach. This paper also reviewed relevant models and theories that align with the goals of this research to provide a broader view of the problems with HRD in Ghana and to help develop a framework that seeks to provide a sustainable guide for those involved in HRD activities in Ghana.

Findings

A positive outcome from the synergistic alignment between modern science and indigenous ecological knowledge moderated by the principles of CHRD will result in economic growth and development. HRD’s contribution to economic growth and development and its consequential benefit to the actors will depend on how best CHRD goals are accomplished.

Practical implications

The mediating role of the tempered radicalism will help modify the swiftness with which education and HRD programs are executed in Ghana.

Originality/value

This paper presented the tempered radicalism approach as the quintessential model for education and HRD initiatives in Ghana. The application of tempered radicalism in HRD literature is novel.
Trust initiation and development in SME-university collaborations: implications for enabling engaged scholarship
Authors: Darabi Fariba , Saunders Mark N.K. , Clark Murray
Published: October 2020

Purpose

The purpose of this study is to explore trust initiation and development in collaborations between universities and small- and medium-sized enterprises (SMEs) and the implications for enabling engaged scholarship (ES).

Design/methodology/approach

Adopting a qualitative inductive approach, semi-structured interviews were conducted with a purposive maximum variation sample comprising 14 SMEs and 12 university stakeholders.

Findings

The authors highlight the role of calculus-based trust in the initiation of collaborations emphasising the key roles of networking and referrals. As collaborations develop, reciprocal insights regarding stakeholders’ competencies and integrity and the development of knowledge-based trust can support engagement, in particular, knowledge application. Although relationships have a common sense of purpose, a fully engaged campus remains absent.

Research limitations/implications

This study is based on a collaborative research between eight SMEs and one university business school and does not reflect ES fully as conceptualised. It provides few insights into the role of trust (or distrust) in such collaborations where things go wrong.

Practical implications

Universities looking to enable ES collaborations with SMEs need to develop and enact strategies which support ongoing engagement and enable identification-based trust (IBT). Recommendations for universities and human resource development regarding interventions to support trust initiation and development to enable knowledge application ES are outlined and suggestions are offered for future research.

Social implications

University strategies to support the development of trust and, in particular, IBT are likely to benefit longer-term relationships and the development of ES between SMEs and universities.

Originality/value

Little research has been undertaken on trust initiation and development between academic and SME stakeholders or the associated implications for ES.
Challenges in successful implementation of Digital contact tracing to curb COVID-19 from global citizen’s perspective: a text analysis study
Authors: S.V. Praveen , Ittamalla Rajesh , Subramanian Dhilip
Published: October 2020

Purpose

The word “digital contact tracing” is often met with different reactions: the reaction that passionately supports it, the reaction that neither supports nor oppose and the one that vehemently opposes it. Those who support the notion of digital contact tracing vouch for its effectiveness and how the complicated process can be made simpler by implementing digital contact tracing, and those who oppose it often criticize the imminent threats it possesses. However, without earning the support of a large population, it would be difficult for any government to implement digital contact tracing to perfection. The purpose of this paper is to analyze, using machine learning, how different continents have different sentiments over digital contact tracing being used as a measure to curb COVID-19.

Design/methodology/approach

For the analysis, data were collected from Twitter. Tweets that contain the hashtag and the word “digital contact tracing” were crawled using Python library Tweepy. Tweets across countries of four continents were collected from March 2020 to August 2020. In total, 70,212 tweets were used for this study. Using the machine learning algorithm, the authors detected the sentiment of all the tweets belonging to each continent. Structural topic modeling was used to understand the overall significant issues people voice out by global citizens while sharing their opinions on digital contact tracing.

Findings

This study was conducted in two parts. Study one results show that North American and European citizens share more negative sentiments toward “digital contact tracing.” The citizens of the Asian and South American continent mostly share neutral sentiments regarding the digital contact tracing. Overall, only 33% of total tweets were positively related to contact tracing, whereas 52% of the total tweets were neutral. Study two results show that factors such as fear of government using contact tracing to spy on its people, the feeling of being unsafe and contact tracing being used to promote an agenda were the three major issues concerning the overall general public.

Originality/value

Despite numerous studies being conducted about how to implement the contact tracing efficiently, minimal studies were done to explore the possibility and challenges in implementing it. This study fills the gap.
How reviewer level affects review helpfulness and reviewing behavior across hotel classifications: the case of Seoul in Korea
Authors: Hlee Sunyoung
Published: October 2020

Purpose

The purpose of this study is to explore the effect of reviewer qualification and credibility (RQC) and hotel classification involving online hotel reviews (OHRs). The study examines the effects of the reviewer level as a proxy of RQC on review helpfulness and reviewing behavior (review rating, review length). The study also included hotel classification as a moderating variable.

Design/methodology/approach

Data from 1,968 reviews were collected from TripAdvisor.com using a web data-harvesting technique. Hypothesized relations in the model were tested with t-test and MANOVA analysis.

Findings

The empirical results show that the effect of reviewer level on review helpfulness is not significant. In addition, a high-level reviewer tends to leave a lower rating and a lengthier review than a low-level reviewer. Regarding the moderating effects, for the high-level reviewer, three-star independent hotels have a greater effect on review helpfulness.

Research limitations/implications

The study has several useful implications for researchers, hotel industry when managing OHR and disseminating information to their potential consumers.

Practical implications

The findings help online review website organizers manage the operation of RQC and hotel classification in a proper manner. Marketing managers, especially those of three-star independent hotels, can effectively utilize review management to the desired effect.

Originality/value

Unlike previous studies, this study explores the effect of RQC on review helpfulness and reviewing behaviors across the hotel classification. In addition, this study contributes to the hotel industry developing more effective online reviews from the reviewer level and diverse hotel types (three-star independent, four-star chain, five-star luxury hotels).
Saving for the bad times: slack resources during an economic downturn
Authors: Agusti Maria , Galan Jose L. , Acedo Francisco J.
Published: October 2020

Purpose

This paper aims to examine what firms in Spanish industrial sectors redeployed their resources, depending on their organisational slack (resource excess), when faced with the global economic crisis of 2008.

Design/methodology/approach

Various financial measures for slack resources and performance have been analysed from more than 400 Spanish firms from 2006 (pre-crisis) to 2017 (recovery).

Findings

The first finding is that every slack is useful against an economic downturn. The results show how industrial companies use their slack resources when faced with a generalised crisis according to the level of slack possessed. The key role of the available slack against this environmental threatens is remarked.

Research limitations/implications

Not every resource is useful against an economic downturn. The results show how industrial companies use their slack resources when faced with a generalised crisis in accordance with the types and levels of slack. The key role of the liquid resources, in particular cash, against this environmental threat is discussed. However, we also observe the behaviour of firms with only a few excess resources and find very similar resource consumption patterns.

Originality/value

Although organisational slack is a well-known concept in management, few studies deal with how companies consume or use other types of resources when confronting a crisis. This paper not only addresses this question but also offers insights for a detailed evaluation of various types of slack during and after a crisis.
Financial literacy programs and youth entrepreneurial attitudes: some insights from the Jordanian community
Authors: Aljaouni Nour Walid , Alserhan Baker , Gleason Kimberly , Zeqiri Jusuf
Published: October 2020

Purpose

The purpose of this paper is to explore the impact of a financial literacy program (FLP) recently implemented in Jordanian junior high and high schools as part of a national financial literacy agenda on students’ attitudes toward entrepreneurship relative to a control sample of students who had not yet participated in the FLP. This paper also examines the role of moderating variables, including students’ perception of teachers’ attitudes (TA) on students’ entrepreneurial attitudes.

Design/methodology/approach

Survey methodology was used to obtain data and hierarchical regression analysis was used to test hypotheses.

Findings

Results indicate that students who completed the FLP exhibited significantly higher entrepreneurial awareness than those that had not yet participated in the program. Students who took the entrepreneurship module of the FLP exhibited significantly lower entrepreneurial intention than those that had not yet taken the entrepreneurship module. However, TA did not impact students’ attitudes.

Research limitations/implications

The study examines a sample of middle and high school students in only one district in Amman, Jordan, and cannot be generalized to other communities where the FLP has been implemented.

Practical implications

The findings provide valuable insights for educators, policymakers and non-governmental organizations considering large scale, publicly funded FLPs as part of the K-12 educational system.

Social implications

Stakeholders should consider reforms to the implementation of entrepreneurship education as part of the FLP in Jordanian schools and other developing country K-12 programs.

Originality/value

This study is the first to examine the new Jordanian literacy program and the impact it has on attitudes toward entrepreneurship of middle and high school students.
Brand co-creation through participation of organization, consumers, and suppliers: an empirical validation
Authors: Sarkar Sanmitra , Banerjee Saikat
Published: October 2020

Purpose

The purpose of this paper is to empirically validate the role of different stakeholders in a co-creation context. In this paper, a new triadic brand co-creation concept has been presented highlighting why consumers participate in brand co-creation, what is the role of the organizing company and what is the role of suppliers in such event and what are the benefits each of these three stakeholders receives in-turn of participating in such an event.

Design/methodology/approach

A quantitative approach has been adopted in this study using structural equation modeling to verify brand co-creation from the triadic stakeholder participation standpoint.

Findings

The empirical study validates that consumer’s perceived psychological benefits, brand self-connection and participation in brand communities all have a positive impact on the brand co-creation process. The results also suggest co-creating organizations should create an environment of trust and openness in such a brand co-creation event and they should show participatory leadership and provide proper tools and training to the participating consumers. The participating suppliers should show higher levels of professionalism, they should be willing to invest in research and development (R&D) and collaborate with organizations in their R&D effort. The results also validate that the brand co-creation event ensures increased brand knowledge and value of consumers. Also, brand co-creation is positively related to purchasing, helping others and consumers’ feedback intention. Through brand co-creation sponsoring organizations creates innovation and reduces resource issues and marketing costs. The results also show that brand co-creation can lead to better brand loyalty among consumers. Suppliers should also be actively engaged in brand co-creation as it leads to a better performance in terms of greater revenue, market offerings and reputation.

Research limitations/implications

The research investigates all aspects of inputs and benefits of the three different stakeholders – consumers, organizations and suppliers. It gives a comprehensive framework to validate the roles and benefits of each of the stakeholders from a consumer’s viewpoint. It conceptualizes and validates the constructs to provide the holistic concept and its associated framework.

Practical implications

The findings offer new insights to brand managers, Chief Experience Officers of how a brand co-creation event can be organized successfully, what should be the role of them, how they should involve suppliers in this kind of an event and finally how this kind of event can have a long-term impact on the brand in question.

Originality/value

This is the first empirical research on brand co-creation which investigates the roles and benefits from a triadic stakeholders’ standpoint. This study also analyzes and validates the comprehensive framework of brand co-creation proposed.
Co-creational leadership capability for driving health-care service innovation
Authors: Sharma Shikha
Published: October 2020

Purpose

The purpose of this paper is to identify and explore leadership capability for driving value co-creation in health-care service innovation. The leadership theories developed for leading within organization boundaries can no longer apply when customers and multiple participants are collaborating for innovative services. This study uses the dynamic capability theory to identify leadership capability that supports value co-creation in health-care service innovation.

Design/methodology/approach

Two case studies of Australian mental health organizations are used to identify co-creational leadership capability. These organizations have successfully embedded co-creational leadership capability in organizational systems and structure as the dynamic capability.

Findings

The study is among the first one to identify the leadership capability from a service-dominant logic perspective. Drawing from dynamic capability theory, six characteristics of co-creational leadership capability are identified, namely, creating a combined world view, creating a shared vision, facilitating an environment of trust, facilitating knowledge creation and knowledge sharing, empowering choice and facilitating collaboration.

Originality/value

This research has extended the leadership and the value co-creation literature by identifying co-creational leadership capability to drive value co-creation agenda for improving organizational results and performance.
PPPs and non-financial value: a critical analysis of public policy and implications for social, environmental and indigenous cultural values
Authors: Boyce Gordon , McDonald-Kerr Lachlan
Published: October 2020

Purpose

This paper investigates how contemporary public policy for public-private partnerships (PPPs) deals with non-financial values and thereby shapes the way social, cultural and environmental issues are accounted for.

Design/methodology/approach

A case study critically analyses PPP policy in Victoria, Australia, an acknowledged leader in the area. The investigation of the policy’s approach to non-financial value focusses on the treatment of social and environmental issues, particularly in relation to indigenous cultural heritage values.

Findings

It is found that important non-financial issues are characterised as risks to be quantified and monetised in PPP project assessment. A critical analysis shows that this approach obscures many significant dimensions of social, environmental and Indigenous cultural heritage value. The resultant relegation of non-financial values in public discourse and decision-making is seen to entrench unsustainable practices.

Social implications

The paper shows how public policy may shape actions and outcomes that impact directly on social, environmental and indigenous cultural heritage values.

Originality/value

This study provides insights into contemporary social and environmental accounting and accountability for PPPs. It adds to the understanding of the implications of public policy framings of non-financial values.
Numerical modeling of structural capacity of corroded bolted assembly
Authors: Radouani Rachid , Essahli Mohamed , Ech-Charqy Younes
Published: October 2020

Purpose

Validate the resistance of bolted connections in terms of stresses, resistant moment and contact pressure.

Design/methodology/approach

Finite element modeling of corroded bolted joint.

Findings

The three types of corroded assemblies are resistant to the applied loads.

Originality/value

The research is original, it studies the stress corrosion cracking of a bolted assembly's end plate by the finite element method.
Observational equivalence of balanced growth with external habit formation
Authors: Wang Wei
Published: October 2020

This paper investigates two scenarios in the external habit formation model with concave utility functions. When the utility function is weakly concave, there exists a unique history‐dependent balanced growth path (BGP) under a knife‐edge existence condition. When the utility function is strictly concave, a unique BGP exists under a more generic condition. I find that the BGPs in the two scenarios are observationally equivalent. The knife‐edge condition limits the applicability of the first scenario. The generic existence condition and the observational equivalence result mitigate this issue. I show that our model can help understand a variety of growth patterns of countries that differ in their fundamentals substantially.
Discovering and Managing Interdependence with Customer‐Entrepreneurs
Authors: Park Hyunkyu , Ritala Paavo , Velu Chander
Published: October 2020

Research on inter‐organizational relationships has largely focused on the interdependence between formal organizations. In recent years, firms have encountered a new logic in which interdependent parties are not formal organizations but platform‐based ‘customer‐entrepreneurs’ that create value through illegal means. Drawing on a 5‐year‐long qualitative study, we examine how firms recognize and instantiate this new logic and, consequently, respond to their interdependencies with customer‐entrepreneurs. Viewed through the lens of institutional logic, we find that, with the benefit of hindsight, firms recognize the existence of the logic of customer entrepreneurship, which triggers organizational sensemaking that is made up of three elements: interpretation of legitimacy compatibility; interpretation of efficiency compatibility; and integration of stakeholder perspectives. This sensemaking results in either a determined account concluding on the compatibility calculus in a top‐down manner, or an open‐ended account avoiding the construction of a resolute, synthesized view. A determined account leads to a defiance strategy, by which firms attempt to remove the source of interdependencies with customer‐entrepreneurs, whereas an open‐ended account guides firms to espouse a decoupling strategy, whereby firms covertly resort to efficiency maximization enabled by the interdependence. Our results offer implications for the research on inter‐organizational relationships and institutional logic.
Use of forested field edges by a blueberry insect pest, Rhagoletis mendax (Diptera: Tephritidae)
Authors: Drummond Francis A. , Collins Judith A. , Rodriguez‐Saona Cesar , Zhang Aijun
Published: October 2020

The blueberry maggot fly, Rhagoletis mendax Curran, is a pest of wild and highbush blueberries. In wild blueberries, most flies colonize fields from forest edges annually. Flies were associated with forest canopies adjacent to colonized fields.

Flies were captured up to 6 m high (limited by trap placement height) and may occur at greater tree heights. Fly abundance relative to tree species was highest in red oak.

Releases of marked flies from tree canopies showed that release height had no effect on distance into the field that flies dispersed. This is important because the main fly control tactic is the application of a 25‐ to 30‐m‐wide swath of insecticide along field perimeters.

In the laboratory, flies preferred leaves and leaf extracts of red oak compared to other leaf tree and shrub species, including blueberry. Electroantennographs demonstrated that the female antennae consistently responded to compounds extracted from red oak leaves. Mass spectra and gas chromatograph retention times of five antenna‐active compounds matched those of (i) trans‐β‐ocimene, (ii) linalool, (iii) 4,8‐dimethyl‐1,3,7‐nonatriene, (iv) indole, and (v) trans‐nerolidol.

We speculate flies recruit to trees before movement into blueberry fields primarily for food, as supported by their arrestment response to leaf extracts.
Smart materials in cardiovascular implants: Shape memory alloys and shape memory polymers
Authors: Holman Heather , Kavarana Minoo Naozer , Rajab Taufiek Konrad
Published: October 2020

Smart materials have intrinsic properties that change in a controlled fashion in response to external stimuli. Currently, the only smart materials with a significant clinical impact in cardiovascular implant design are shape memory alloys, particularly Nitinol. Recent prodigious progress in material science has resulted in the development of sophisticated shape memory polymers. In this article, we have reviewed the literature and outline the characteristics, advantages, and disadvantages of shape memory alloys and shape memory polymers which are relevant to clinical cardiovascular applications, and describe the potential of these smart materials for applications in coronary stents and transcatheter valves.
Responsibility of the University in Employability: Development and validation of a measurement scale across five studies
Authors: López‐Miguens María Jesús , Caballero Gloria , Álvarez‐González Paula
Published: October 2020

This paper develops and validates, at a confirmatory level, a second‐order scale to measure Responsibility of the University in Employability (RUE). First, the literature on the components of RUE is explored and a formative conceptual model is proposed to underpin its measurement using extant research in the field of organisational responsibility and employability. At the empirical level, the second‐order RUE model considers the reputation of the university, the teaching staff, and the matching activities with employers as components of RUE. This model is based on five empirical studies. The first is a small‐sample study based on the opinions of experts (n = 5) and the rest are based on representative samples of university students (n = 816, n = 1,082, n = 1,088, and n = 1,203). A very good fit between model and data were revealed (CFI = 0.975; RMSEA = 0.039; standardised X2 = 2.676). The results indicate that matching activities with employers and teaching staff generate more RUE than university reputation. Guidelines are offered for managing the responsibility of the university in employability.
‘That’s just how I am’: a qualitative interview study to identify factors influencing engagement with a digital intervention for tinnitus self‐management
Authors: Greenwell Kate , Sereda Magdalena , Coulson Neil S. , Geraghty Adam W. A. , Bradbury Katherine , Hoare Derek J.
Published: October 2020

Objectives

To explore users’ reactions to and expectations of the Tinnitus E‐Programme 2.0, a digital cognitive behavioural intervention for tinnitus, and to identify contextual factors and mechanisms of action that may influence user engagement with the intervention.

Design

Qualitative interview study.

Methods

Think‐aloud and semi‐structured interviews were carried out with 19 people with tinnitus. Interviews explored participants’ views of the intervention’s information and advice, its wider intervention goals (e.g. behaviour change, self‐management), and factors that may strengthen or impede users’ engagement. Data were analysed using inductive thematic analysis, and findings were used to develop a conceptual model of user engagement with the intervention.

Results

Generally, participants expressed positive views of the intervention, its intervention components, and its design features. Identified contextual factors included pre‐existing attitudes, beliefs, skills, and knowledge (e.g. perceptions of tinnitus symptom severity, openness to tinnitus management, and psychological techniques); previous experience of tinnitus management; and characteristics of the condition (e.g. heterogeneous nature of tinnitus, stage in healthcare journey). These contextual factors were hypothesized to influence engagement through four mechanisms of action: motivation to change tinnitus‐related attitudes and behaviour; perceived personal relevance of the intervention; expectations of benefit; and appeal of the intervention techniques.

Conclusions

This study demonstrated the acceptability of the Tinnitus E‐Programme 2.0 amongst its target group, while highlighting potential areas for improvement in future intervention modifications. Our findings identified contextual factors that others developing interventions for tinnitus or cognitive behavioural interventions may wish to consider.
Negotiating identities and social representations through intergroup contact in a community solidarity initiative
Authors: Vine Megan , Greenwood Ronni Michelle
Published: October 2020

In Ireland, displaced people experience segregation, discrimination, and disempowering regulations within the Direct Provision system. Community solidarity initiatives (CSI) aim to address the segregation and discrimination displaced people face through collaborative contact with residents/nationals of Ireland. However, asymmetric power relations mean that residents/nationals and displaced people are likely to experience intergroup contact differently, which has implications for identity negotiation. We investigated how displaced people and residents/nationals negotiated their identities and oriented to social representations in talk about their experiences of a CSI in the West of Ireland. We interviewed 17 displaced people and residents/nationals and conducted a thematic analysis, informed by Social Identity Approach and Social Representations Theory. Then, we applied a discursive approach to understand how participants constructed social identities and social representations. Our analysis produced two main themes: ‘Identity negotiation strategies in talk about intergroup contact’ and ‘Understanding and orienting to intergroup boundaries’. We found that residents/nationals and displaced people negotiated their identities to maintain positive identification in relation to negative social representations about their groups. Participants also oriented to shared group representations in their talk , which has implications for the development of political solidarity between residents/nationals and displaced people.
ACTH following overnight dexamethasone suppression can be used in the verification of autonomous cortisol secretion in patients with adrenal incidentalomas
Authors: Puvaneswaralingam Shobitha , Kjellbom Albin , Lindgren Ola , Löndahl Magnus , Olsen Henrik
Published: October 2020

Objective

During the investigation of adrenal incidentalomas, it is important to accurately diagnose autonomous cortisol secretion (ACS) but the specificity of cortisol ≥50 nmol/L after overnight dexamethasone suppression (cortisolONDST) is low. Therefore, ACTH following overnight dexamethasone suppression (ACTHONDST) and cortisol following a 2‐day dexamethasone suppression test (cortisol2‐DAYDST) were examined as markers of HPA axis suppression during ONDST.

Design

This cross‐sectional study examined patients with adrenal incidentalomas and basal ACTH ≥ 2.0 pmol/L who underwent ONDST.

Measurements

ACTHONDST/ACTH ratio (ACTH ratio) was calculated for all patients. To define cut‐off levels for ACTHONDST and ACTH ratio as markers of HPA axis suppression, ROC curves were used to separate patients with cortisolONDST <50 and ≥50 nmol/L.

Results

CortisolONDST was ≥50 nmol/L in 140 out of 373 patients. In patients with cortisolONDST <50 nmol/L, ACTHONDST was 0.28 pmol/L (<0.23–2.7). DHEAS was positively correlated to ACTHONDST, demonstrating a 9% increase with a doubling in ACTHONDST, p = 0.02. The best cut‐off levels for ACTHONDST and ACTH ratio to detect cortisolONDST ≥50 nmol/L were ≥0.6 pmol/L and ≥18% respectively. These cut‐off levels were tested on patients with cortisolONDST <50 nmol/L, considered to have adequate suppression (n = 233), and patients with reduction of ≥50 nmol/L from cortisolONDST to cortisol2‐DAYDST, who were considered to have inadequate suppression (n = 16). ACTHONDST ≥0.6 pmol/L and ACTH ratio ≥18% had a sensitivity of 75% and 81% respectively, and a specificity of 78% and 85% respectively, for detecting patients with inadequate suppression.

Conclusions

ACTHONDST and ACTH ratio can be markers of HPA axis suppression in the investigation of adrenal incidentalomas. CortisolONDST ≥50 nmol/L with ACTHONDST <0.6 pmol/L or ACTH ratio <18% should lead to the suspicion of ACS.
Relations between parent–child interaction and children’s engagement and learning at a museum exhibit about electric circuits
Authors: Sobel David M. , Letourneau Susan M. , Legare Cristine H. , Callanan Maureen
Published: October 2020

Play is critical for children's learning, but there is significant disagreement over whether and how parents should guide children's play. The objective of the current study was to examine how parent–child interaction affected children's engagement and problem‐solving behaviors when challenged with similar tasks. Parents and 4‐ to 7‐year‐old children in the U.S. (N = 111 dyads) played together at an interactive electric circuit exhibit in a children's museum. We examined how parents and children set and accomplished goals while playing with the exhibit materials. Children then participated in a set of challenges that involved completing increasingly difficult circuits. Children whose parents set goals for their interactions showed less engagement with the challenge task (choosing to attempt fewer challenges), and children whose parents were more active in completing the circuits while families played with the exhibit subsequently completed fewer challenges on their own. We discuss these results in light of broader findings on the role of parent–child interaction in museum settings.
The four I's of adolescent transition in type 1 diabetes care: A qualitative study
Authors: Leung Joseph M. W. S. , Tang Tricia S. , Lim Catherine E. , Laffel Lori M. , Amed Shazhan
Published: October 2020

Aims

To explore adolescent perspectives on programme design in the transition to adult care.

Methods

We conducted five focus groups on adolescents with type 1 diabetes nearing the age of transition to adult care. Study participants also completed an embedded survey where they rated a wide range of potential transition interventions. Focus group transcripts were analysed with three iterations of line‐by‐line coding to triangulate themes and subthemes.

Results

Four themes were identified: Individualization—how to personalize the transition experience (having choices in the transition experience, meeting adult provider before transition and specific transition preparation); Identity—how the world relates to my diabetes (stigma of type 1 diabetes, confusion with type 2 diabetes, diagnosis disclosure and resilience); Interconnection—how my support system can help me with my diabetes (peer support, near peer support, parental support, loss of bond with paediatric team and fear of not having a bond with adult team); and Impediment—how my diabetes limits me (self‐care takes work and time, unpredictability and restrictiveness, and emotional burden). Highly rated interventions from the survey included: good communication between the paediatric and adult teams, medical summary of past diabetes care, and having paediatric and adult teams in the same building.

Conclusions

The design of future transition interventions for adolescents with type 1 diabetes should address the issues of Individualization, Identity, Interconnection and Impediment. Collaborative processes between paediatric and adult providers were also rated as important strategies to facilitate the transition to adult care.
Trump’s “maximum pressure” and anti‐containment in Iran’s regional policy
Authors: Azizi Hamidreza , Golmohammadi Vali , Vazirian Amir Hossein
Published: October 2020

Two years after withdrawing from the Iran nuclear deal, U.S. President Donald Trump's “maximum pressure” campaign has failed to change Iran's regional behavior, bring Tehran back to the negotiation table, curb its nuclear and missile programs, and counter Iran's proxy influence in the region. Instead, Iran has adopted a “maximum resistance” strategy to deal with Washington's pressure. According to the Neorealist school of thought in International Relations (IR), rising systemic or structural pressure on a given state is expected to alter its policies or even its regime. The case of Iran appears to challenge this expectation. This article suggests that Iran has adopted an “anti‐containment” strategy to deal with the U.S. pressure. The strategy is based on asymmetric deterrence, the main pillars of which are employing local allied forces and enhancing air and naval deterrence capabilities. Meanwhile, Iran's military–security establishment has gained the upper hand in dealing with the United States, sidelining the diplomatic apparatus. This situation bears the risk of a confrontation between Iran and the United States while leaving no space for meaningful diplomatic engagement.
Preoperative right ventricular strain predicts sustained right ventricular dysfunction after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension
Authors: Tsugu Toshimitsu , Kawakami Takashi , Kataoka Masaharu , Endo Jin , Kohno Takashi , Itabashi Yuji , Fukuda Keiichi , Murata Mitsushige
Published: October 2020

Aims

Balloon pulmonary angioplasty (BPA) improves hemodynamics and exercise tolerance in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, its diagnostic and predictive values remain unclear. We investigated the diagnostic and predictive values of BPA by assessing the mechanism of right ventricular (RV) dysfunction.

Methods and Results

Hemodynamic improvement was maintained over 6 months in 99 patients with CTEPH who underwent BPA. Notably, 57 of 99 patients showed normalization of pulmonary vascular resistance (PVR) after BPA. The RV mid free wall longitudinal strain (RVMFS) was inversely correlated with the 6‐min walk distance (r = −.35, P = .01) and serum levels of high‐sensitivity cardiac troponin T (hs‐cTNT) (r = −.39, P = .004) 6 months post‐BPA in the PVR‐normalized group. Among all variables analyzed, only the pre‐BPA RVMFS was correlated with the post‐BPA RVMFS (r = .40, P = .001), and the pre‐BPA RVMFS (<−15.8%) was the strongest predictor of post‐BPA normalization of RVMFS (area under the curve 0.80, P = .01, sensitivity 89%, and specificity 63%). The immediate post‐BPA RVMFS showed worsening over 6 months after the procedure (−25.8% to −21.1%) in patients with high serum hs‐cTNT levels (>0.0014 ng/mL). In contrast, we observed an improvement in these values in those with low serum hs‐cTNT levels (−23.6% to −24.4%).

Conclusion

RVMFS of −15.8% may be a useful cutoff value to categorize the refractory and non‐refractory stages of disease. Sustained serum hs‐cTNT elevation post‐BPA indicates subclinical RV myocardial injury, with resultant RVMFS deterioration and poor exercise tolerance.
Supracardiac total anomalous pulmonary venous connection with cor triatriatum sinister: A rare diagnosis confirmed by saline contrast echocardiography
Authors: Relan Jay , Choubey Mrigank , Kothari Shyam Sunder
Published: October 2020

In cor triatriatum sinister, the left atrium is divided by a membrane into a proximal and a distal chamber. Usually proximal chamber receives all the pulmonary veins and drains through an opening in the dividing membrane into distal chamber, which empties into left ventricle through the mitral valve. Rarely, the two chambers lack a communication and there is associated total anomalous pulmonary venous connection (TAPVC). We report a 1‐month‐old infant with cyanosis and heart failure, who had cor triatriatum sinister associated with supracardiac TAPVC. The case is reported for rarity of the association with a focus on contrast echocardiographic imaging.
Monitoring treatment response and disease progression in myeloma with circulating cell‐free DNA
Authors: Deshpande Shayu , Tytarenko Ruslana G. , Wang Yan , Boyle Eileen M. , Ashby Cody , Schinke Carolina D. , Thanendrarajan Sharmilan , Zangari Maurizio , Zhan Fenghuang , Davies Faith E. , Morgan Gareth J. , van Rhee Frits , Walker Brian A.
Published: October 2020

Circulating cell‐free DNA (cfDNA) has the potential to capture spatial genetic heterogeneity in myeloma (MM) patients. We assessed whether cfDNA levels vary according to risk status defined by the 70 gene expression profile (GEP70). cfDNA levels in 77 patients were significantly higher in the GEP70 high‐risk (HR) group compared to the low‐risk (LR) group and correlated weakly with clinical markers including lactate dehydrogenase, β2‐microglobulin, and ISS. Patients with high cfDNA levels were associated with a worse PFS (hazard ratio 6.4; 95% CI of ratio 1.9‐22) and OS (hazard ratio 4.4; 95% CI of ratio 1.2‐15.7). Circulating tumor DNA (ctDNA) was elevated in the HR group and ctDNA correlated strongly with GEP70 risk score (Spearman r = .69, P = .0027). cfDNA concentrations were significantly elevated between days 3‐5 after chemotherapy before falling back to baseline levels. ctDNA in two patients showed a similar spike in levels between days 3 and 5 after chemotherapy with a concomitant increase in allele fraction of KRAS mutations. We assessed cfDNA levels in 25 patients with smoldering myeloma with serial samples and showed increased allele fraction of mutated KRAS at progression in cfDNA. Our study shows that cfDNA is a dynamic tool to capture genetic events in myeloma.
Optical coherence tomography measurements as potential imaging biomarkers for Parkinson's disease: A systematic review and meta‐analysis
Authors: Zhou Wen‐Chuan , Tao Jin‐Xin , Li Jing
Published: October 2020

Background and purpose

Retinal pathological changes may precede or accompany the deterioration of brain tissue in Parkinson's disease (PD). The purpose of this meta‐analysis was to assess the usefulness of optical coherence tomography (OCT) measurements as potential imaging biomarkers for PD.

Methods

PubMed, Embase, Web of Science and Cochrane Library databases were systematically searched for observational studies (published prior to 30 May 2020) comparing the OCT measurements between PD patients and healthy controls (HCs). Our main end‐points were peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell complex thickness, macular thickness and macular volume. Pooled data were assessed by use of a random‐effects model.

Results

A total of 36 observational studies were identified that included 1712 patients with PD (2548 eyes) and 1778 HCs (2646 eyes). Compared with the HC group, the PD group showed a significant reduction in mean pRNFL thickness (weighted mean difference [WMD] −3.51 μm, 95% confidence interval [CI] −4.84, −2.18; p = 0.000), all quadrants at the pRNFL (WMD range −7.65 to −2.44 μm, all p < 0.05), macular fovea thickness (WMD −5.62 μm, 95% CI −7.37, −3.87; p = 0.000), all outer sector thicknesses at the macula (WMD range −4.68 to −4.10 μm, all p < 0.05), macular volume (WMD −0.21 mm3, 95% CI −0.36, −0.06; p < 0.05) and macular ganglion cell complex thickness (WMD −4.18 μm, 95% CI −6.07, −2.29; p < 0.05).

Conclusions

Our pooled data confirmed robust associations between retinal OCT measurements and PD, highlighting the usefulness of OCT measurements as potential imaging biomarkers for PD.
The Bioavailability of Dissolved, Particulate, and Adsorbed Organic Carbon in Groundwater Systems
Authors: Chapelle Francis H.
Published: October 2020

Dissolved organic carbon (DOC) is the smallest amount of organic carbon present in aquifer systems and is typically dwarfed by amounts of particulate organic carbon (POC) and adsorbed organic carbon (AOC). Research conducted over the last half century, however, has shown that these dissolved, particulate, and adsorbed compartments interact dynamically with each other. That suggests the hypothesis that the bioavailability of DOC in groundwater may indicate the bioavailability of the associated POC and AOC compartments as well. If that proves to be the case, it would greatly simplify the process of evaluating the bioavailability of total organic carbon present in groundwater systems. That hypothesis was examined by (1) comparing DOC bioavailability between two aquifers receiving modern atmospheric recharge, but with the recharge passing through POC/AOC sources of substantially different geologic ages, and (2) measuring POC/AOC bioavailability in sediments in from two aquifers before and after injection with bioavailable DOC consisting of dissolved sugars and emulsified vegetable oil. The results of both comparisons are consistent with the hypothesis that DOC bioavailability in groundwater reflects the bioavailability of the associated POC and AOC compartments and vice versa. Thus, DOC bioavailability may be a useful indicator of an aquifer's potential to drive reduction/oxidation processes that affect the chemical quality of groundwater.