bluuebunny/crossref_metadata_2025 huggingface dataset:
Sparse Deep Neural Networks on Imaging Genetics for Schizophrenia Case-Control Classification
Authors: Chen Jiayu , Li Xiang , Calhoun Vince D. , Turner Jessica A. , van Erp Theo G. M. , Wang Lei , Andreassen Ole A. , Agartz Ingrid , Westlye Lars T. , Jönsson Erik , Ford Judith M. , Mathalon Daniel H. , Macciardi Fabio , O’Leary Daniel S. , Liu Jingyu , Ji Shihao
Published: June 2020

Machine learning approaches hold potential for deconstructing complex psychiatric traits and yielding biomarkers which have a large potential for clinical application. Particularly, the advancement in deep learning methods has promoted them as highly promising tools for this purpose due to their capability to handle high-dimensional data and automatically extract high-level latent features. However, current proposed approaches for psychiatric classification or prediction using biological data do not allow direct interpretation of original features, which hinders insights into the biological underpinnings and development of biomarkers. In the present study, we introduce a sparse deep neural network (DNN) approach to identify sparse and interpretable features for schizophrenia (SZ) case-control classification. An L0-norm regularization is implemented on the input layer of the network for sparse feature selection, which can later be interpreted based on importance weights. We applied the proposed approach on a large multi-study cohort (N = 1,684) with brain structural MRI (gray matter volume (GMV)) and genetic (single nucleotide polymorphism (SNP)) data for discrimination of patients with SZ vs. controls. A total of 634 individuals served as training samples, and the resulting classification model was evaluated for generalizability on three independent data sets collected at different sites with different scanning protocols (n = 635, 255 and 160, respectively). We examined the classification power of pure GMV features, as well as combined GMV and SNP features. The performance of the proposed approach was compared with that yielded by an independent component analysis + support vector machine (ICA+SVM) framework. Empirical experiments demonstrated that sparse DNN slightly outperformed ICA+SVM and more effectively fused GMV and SNP features for SZ discrimination. With combined GMV and SNP features, sparse DNN yielded an average classification error rate of 28.98% on external data. The importance weights suggested that the DNN model prioritized to select frontal and superior temporal gyrus for SZ classification when a high sparsity was enforced, and parietal regions were further included with a lower sparsity setting, which strongly echoed previous literature. This is the first attempt to apply an interpretable sparse DNN model to imaging and genetic features for SZ classification with generalizability assessed in a large and multi-study cohort. The results validate the application of the proposed approach to SZ classification, and promise extended utility on other data modalities (e.g. functional and diffusion images) and traits (e.g. continuous scores) which ultimately may result in clinically useful tools.
Gravin-associated kinase signaling networks coordinate γ-tubulin organization at mitotic spindle poles
Authors: Bucko Paula J. , Garcia Irvin , Manocha Ridhima , Bhat Akansha , Wordeman Linda , Scott John D.
Published: June 2020

Mitogenic signals that regulate cell division often proceed through multi-enzyme assemblies within defined intracellular compartments. The anchoring protein Gravin restricts the action of mitotic kinases and cell-cycle effectors to defined mitotic structures. In this report we discover that genetic deletion of Gravin disrupts proper accumulation and asymmetric distribution of γ-tubulin during mitosis. We utilize a new precision pharmacology tool, Local Kinase Inhibition (LoKI), to inhibit the Gravin binding partner polo-like kinase 1 (Plk1) at spindle poles. Using a combination of gene-editing approaches, quantitative imaging, and biochemical assays we provide evidence that disruption of local Plk1 signaling underlies the γ-tubulin distribution defects observed with Gravin loss. Our study uncovers a new role for Gravin in coordinating γ-tubulin recruitment during mitosis and illuminates the mechanism by which signaling enzymes regulate this process at a distinct subcellular location.
A recurrent de novo HSPD1 variant is associated with hypomyelinating leukodystrophy
Authors: Cömert Cagla , Brick Lauren , Ang Debbie , Palmfeldt Johan , Meaney Brandon F. , Kozenko Mariya , Georgopoulos Costa , Fernandez-Guerra Paula , Bross Peter
Published: June 2020

Standardization of the use of next-generation sequencing for the diagnosis of rare neurological disorders has made it possible to detect potential disease-causing genetic variations, including de novo variants. However, the lack of a clear pathogenic relevance of gene variants poses a critical limitation for translating this genetic information into clinical practice, increasing the necessity to perform functional assays. Genetic screening is currently recommended in the guidelines for diagnosis of hypomyelinating leukodystrophies (HLDs). HLDs represent a group of rare heterogeneous disorders that interfere with the myelination of the neurons in the central nervous system. One of the HLD-related genes is HSPD1, encoding the mitochondrial chaperone heat shock protein 60 (HSP60), which functions as folding machinery for the mitochondrial proteins imported into the mitochondrial matrix space. Disease-causing HSPD1 variants have been associated with an autosomal recessive form of fatal hypomyelinating leukodystrophy (HLD4, MitCHAP60 disease; MIM #612233) and an autosomal dominant form of spastic paraplegia, type 13 (SPG13; MIM #605280). In 2018, a de novo HSPD1 variant was reported in a patient with HLD. Here, we present another case carrying the same heterozygous de novo variation in the HSPD1 gene (c.139T > G, p.Leu47Val) associated with an HLD phenotype. Our molecular studies show that the variant HSP60 protein is stably present in the patient's fibroblasts, and functional assays demonstrate that the variant protein lacks in vivo function, thus confirming its disease association. We conclude that de novo variations of the HSPD1 gene should be considered as potentially disease-causing in the diagnosis and pathogenesis of the HLDs.
Clinical IRAK4 deficiency caused by homozygosity for the novel IRAK4 (c.1049delG, p.Gly350Glufs*15) variant
Authors: Jia Alicia , James Elliot , Lu Henry Y. , Sharma Mehul , Modi Bhavi P. , Biggs Catherine M. , Hildebrand Kyla J. , Chomyn Alanna , Erdle Stephanie , Kular Hasandeep , Turvey Stuart E.
Published: June 2020

The innate immune system allows for rapid recognition of pathogens. Toll-like receptor (TLR) signaling is a key aspect of the innate immune response, and interleukin-1 receptor-associated kinase 4 (IRAK4) plays a vital role in the TLR signaling cascade. Each TLR recognizes a distinct set of pathogen-associated molecular patterns (PAMPs) that encompass conserved microbial components such as lipopolysaccharides and flagellin. Upon binding of PAMPs and TLR activation, TLR intracellular domains initiate the oligomerization of the myeloid differentiation primary response 88 (MyD88), IRAK1, IRAK2, and IRAK4 signaling platform known as the Myddosome complex while also triggering the Toll/IL-1R domain-containing adaptor-inducing IFN-β (TRIF)-dependent pathway. The Myddosome complex initiates signal transduction pathways enabling the activation of NF-κB and mitogen-activated protein kinase (MAPK) transcription factors and the subsequent production of inflammatory cytokines. Human IRAK4 deficiency is an autosomal recessive inborn error of immunity that classically presents with blunted or delayed inflammatory response to infection and susceptibility to a narrow spectrum of pyogenic bacteria, particularly Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa. We describe a case of IRAK4 deficiency in an 11-mo-old boy with concurrent S. pneumoniae bacteremia and S. aureus cervical lymphadenitis with a blunted inflammatory response to invasive infection. Although initial clinical immune profiling was unremarkable, a high degree of suspicion for an innate immune defect prompted genetic sequencing. Genetic testing revealed a novel variant in the IRAK4 gene (c.1049delG, p.(Gly350Glufs*15)) predicted to be likely pathogenic. Functional testing showed a loss of IRAK4 protein expression and abolished TLR signaling, confirming the pathogenicity of this novel IRAK4 variant.
Early-onset Wilson disease caused by ATP7B exon skipping associated with intronic variant
Authors: Koboldt Daniel C. , Hickey Scott E. , Chaudhari Bimal P. , Mihalic Mosher Theresa , Bedrosian Tracy , Crist Erin , Kaler Stephen G. , McBride Kim , White Peter , Wilson Richard K.
Published: June 2020

Wilson disease is a medically actionable rare autosomal recessive disorder of defective copper excretion caused by mutations in ATP7B, one of two highly evolutionarily conserved copper-transporting ATPases. Hundreds of disease-causing variants in ATP7B have been reported to public databases; more than half of these are missense changes, and a significant proportion are presumed unequivocal loss-of-function variants (nonsense, frameshift, and canonical splice site). Current molecular genetic testing includes sequencing all coding exons (±10 bp) as well as deletion/duplication testing, with reported sensitivity of >98%. We report a proband from a consanguineous family with a biochemical phenotype consistent with early-onset Wilson disease who tested negative on conventional molecular genetic testing. Using a combination of whole-genome sequencing and transcriptome sequencing, we found that the proband's disease is due to skipping of exons 6–7 of the ATP7B gene associated with a novel intronic variant (NM_000053.4:c.1947-19T > A) that alters a putative splicing enhancer element. This variant was also homozygous in the proband's younger sister, whose subsequent clinical evaluations revealed biochemical evidence of Wilson disease. Our work adds to emerging evidence that ATP7B exon skipping from deep intronic variants outside typical splice junctions is an important mechanism of Wilson disease; the variants responsible may elude standard genetic testing.
CSR practices, identification and corporate reputation
Authors: Bruno Juan Manuel , Sarabia-Sanchez Francisco J. , Bianchi Enrique Carlos
Published: June 2020

Purpose

This study verifies the influence of the dimensions of corporate social responsibility (CSR) practices and consumer involvement on the identification of the individual with the company and the corporate reputation, moderated by the product category.

Design/methodology/approach

A covariance-based structural equation modelling is used to test the model, using a sample of 568 Argentine consumers. A multigroup analysis is employed to assess the moderating effect of the product category.

Findings

CSR practices have heterogeneous influence based on their dimension, and this influence is moderated by the product category. Accordingly, environmental practices promote consumer identification with the company, whereas those economically oriented have a direct influence on reputation. In contrast, social practices contribute to reputation if they are connected to the business model.

Research limitations/implications

The study is focussed on Argentina, analysing two product categories (laptops and financial services for final consumers) and using a large, but not strictly random, sample. In order to mainstream the results, it would be relevant to replicate the proposed model in other countries and with other product categories.

Originality/value

It provides information about the perception of consumers regarding the CSR practices from a multi-dimensional perspective, since they have an uneven effect on identification of consumer with the company and corporate reputation due to the moderating effect of the product category. The findings of this study may be relevant for managers of technology and banking service companies.
Investigation and validation of an eleven level symmetric modular multilevel inverter using grey wolf optimization and differential evolution control algorithm for solar PV applications
Authors: Stonier Albert Alexander , Chinnaraj Gnanavel , Kannan Ramani , Mani Geetha
Published: June 2020

Purpose

This paper aims to examine the design and control of a symmetric multilevel inverter (MLI) using grey wolf optimization and differential evolution algorithms.

Design/methodology/approach

The optimal modulation index along with the switching angles are calculated for an 11 level inverter. Harmonics are used to estimate the quality of output voltage and measuring the improvement of the power quality.

Findings

The simulation is carried out in MATLAB/Simulink for 11 levels of symmetric MLI and compared with the conventional inverter design. A solar photovoltaic array-based experimental setup is considered to provide the input for symmetric MLI. Field Programmable Gate Array (FPGA) based controller is used to provide the switching pulses for the inverter switches.

Originality/value

Attempted to develop a system with different optimization techniques.
Forecasting the price trends of digital currency: a hybrid model integrating the stochastic index and grey Markov chain methods
Authors: Shou Ming-Huan , Wang Zheng-Xin , Li Dan-Dan , Zhou Yi-Tong
Published: June 2020

Purpose

Since the issuance in 2009, the digital currency has enjoyed an increasing popularity and has become one of the most important options for global investors. The purpose of this paper is to propose a hybrid model ( KDJ–Markov chain) which integrates the advantages of the stochastic index (KDJ) and grey Markov chain methods and provide a useful decision support tool for investors participating in the digital currency market.

Design/methodology/approach

Taking Litecoin's closing price prediction as an example, the closing prices from May 2 to June 20, 2017, are used as the training set, while those from June 21 to August 9, 2017, are used as the test set. In addition, an adaptive KDJ–Markov chain is proposed to enhance the adaptability for dynamic transaction information. And the paper verifies the effectiveness of the KDJ–Markov chain method and adaptive KDJ–Markov chain method.

Findings

The results show that the proposed methods can provide a reliable foundation for market analysis and investment decisions. Under the circumstances the accuracy of the training set and the accuracy of the test set are 76% and 78%, respectively.

Practical implications

This study not only solves the problems that KDJ method cannot accurately predict the next day's state and the grey Markov chain method cannot divide the states very well, but it also provides two useful decision support tools for investors to make more scientific and reasonable decisions for digital currency where there are no existing methods to analyze the fluctuation.

Originality/value

A new approach to analyze the fluctuation of digital currency, in which there are no existing methods, is proposed based on the stochastic index (KDJ) and grey Markov chain methods. And both of these two models have high accuracy.
A systematic review of research on abusive supervision in hospitality and tourism
Authors: Yu Yitong , Xu Shi , Li Gang , Kong Haiyan
Published: June 2020

Purpose

This paper aims to provide researchers and practitioners with an understanding of abusive supervision in the context of hospitality. It seeks to conduct a comprehensive review of the area and offer recommendations for future research by exploring the antecedents, consequences, mechanisms and designs of research on abusive supervision.

Design/methodology/approach

Content analysis was conducted to review and analyze studies on abusive supervision in the context of hospitality. Previous studies were searched in the EBSCO, Scopus, Web of Science and Google Scholar electronic databases.

Findings

In total, 36 referred articles related to abusive supervision in hospitality were reviewed across four key areas, namely, antecedents, consequences, mechanisms and research design. After reviewing the research on abusive supervision in the context of hospitality, this paper offers future research directions with respect to research focus and research design.

Research limitations/implications

This paper only included English articles from peer-reviewed journals on abusive supervision. The number of reviewed articles was relatively small. This limitation may have arisen because abusive supervision is a new research field and is still a sensitive topic.

Practical implications

The results of this study may encourage managers to minimize or even halt abusive supervision. From an organizational perspective, formal policies may be developed to regularize supervisors’ behavior. In turn, employees could use this paper to learn further about abusive behavior and how to handle it effectively.

Social implications

The review highlighted the negative consequences of abusive supervision. Managers should urgently realize the seriousness of abusive supervision and develop effective policies to minimize its negative effect.

Originality/value

This paper contributes to the emerging literature on abusive supervision in the context of hospitality by identifying key research trends and framing the outlines of empirical studies. It identifies research gaps, and as the first review of abusive supervision in hospitality, it may encourage researchers to explore the topic on the basis of the characteristics of the sector and offer suggestions for future research.
The effects of uncertainty shocks on global housing markets
Authors: Chien Mei-Se , Setyowati Nur
Published: June 2020

Purpose

This paper aims to investigate how different uncertainty shocks affect international housing prices.

Design/methodology/approach

The authors set up a model of housing price instability with four uncertainty variables and apply the panel generalized method of moments method and quantile regression to estimate the linear and non-linear linkages among the variables based on data of 56 countries from 2001Q1 to 2018Q2.

Findings

Some empirical findings are as follows. Higher macroeconomic uncertainty and global economic policy risk increase housing price instability, whereas greater financial uncertainty and geopolitical risk present reverse effect. Four uncertainty variables are good signals for housing price changes in Asia, and geopolitical risk takes leading role in Europe. Macroeconomic uncertainty positively impacts housing price instability only at a low or middle level in all regions, as financial uncertainty, global economic policy uncertainty and geopolitical risk effects in all regions are smaller at the middle or high level of housing price instability; this confirms the existence of non-linear correlation between each variable.

Originality/value

The findings help investors and policymakers gain a better notion of housing price instability and control into uncertainty signal that could cause housing price instability crash.
Creditors' governance, information asymmetry and debt diversification: evidence from India
Authors: Jadiyappa Nemiraja , Sisodia Garima , Joseph Anto , Shrivastsava Santosh , Jyothi Pavana
Published: June 2020

Purpose

The governing role of bank-appointed directors (BADs) on the boards of non-financial firms has a potential to reduce information asymmetry between the firm and non-bank lenders. This should increase the confidence of other creditors in firm activities, thus performing the certification role. Therefore, the purpose of this paper is to empirically examine the certification role of BADs.

Design/methodology/approach

The authors test their hypotheses by using a panel of Indian non-financial firms. Our approach involves examining whether there is a significant difference in the number of different debt sources, the dispersion of debt among different debt sources, and leverage for BAD and Non_BAD Firms. The authors use univariate analysis and multivariate regression models to test the difference.

Findings

The authors find that firms with BADs on their board have (1) access to a higher number of different debt sources, (2) debt distributed evenly among different sources and (3) a higher debt ratio. Overall, our study provides supporting evidence for the certification role that BADs play on the boards of non-financial firms.

Originality/value

The authors contribute to the literature in two aspects. First, to the best of our knowledge, this is the only study that examines the effect of the governing role of banks on the lending decisions of non-bank lenders. Second, our study is associated with the growing body of the governance literature in the emerging markets context by examining the interaction of financial policies and governance in an institutional framework, which is very different from that of the developed world.
Economic policy uncertainty, R&D expenditures and innovation outputs
Authors: Tajaddini Reza , Gholipour Hassan F.
Published: June 2020

Purpose

The purpose of this study is to examine the relationship between the news-based economic policy uncertainty (EPU), research and development (R&D) expenditures per capita and innovation outputs.

Design/methodology/approach

Data from 1996 to 2015 for 19 countries (Australia, Brazil, Canada, Chile, China, France, Germany, India, Ireland, Italy, Japan, Netherlands, Russia, Singapore, South Korea, Spain, Sweden, the United Kingdom and the United States) are used. The authors apply country and year fixed-effects models for the estimations.

Findings

The study findings show that higher levels of EPU are positively associated with higher R&D expenditures per capita as well as innovation outputs (patent applications, patent grants and trademark applications).

Practical implications

This study deepens our understanding on the policy uncertainty–economic activities nexus and expands the literature on uncertainty, which is still at an initial phase of development, leading to generate a variety of open research questions for further investigation and study (Bloom, 2014).

Originality/value

There has not been an empirical investigation on the links between EPU and R&D expenditures and innovation outputs across several countries. The authors address this gap in the literature.
Knowledge management: does gender matter? A systematic review of literature
Authors: Heisig Peter , Kannan Selvi
Published: June 2020

Purpose

This paper aims to review for the first time existing research literature about the role of gender in creating, sharing and using knowledge in organizations and proposes a conceptual framework to guide future research directions.

Design/methodology/approach

Based on the systematic literature review method this study collects, synthesizes and analyses articles related to knowledge management (KM) and gender published in online databases by following a pre-defined review protocol. The paper analyses 41 papers published in peer-reviewed journals.

Findings

The role of gender in KM has been rarely addressed in KM journals and journals with specific emphasis on gender. The existing literature is fragmented, but existing research suggests that knowledge sharing might be influenced by gender. Based on the analysis and synthesis, a conceptual framework is proposed to guide further research on determining if gender matters in KM.

Research limitations/implications

Academic researchers should aim to include gender-related variables into their KM research to further explore if gender matters in KM.

Practical implications

The practical implication suggests that managers and knowledge managers should raise awareness about how stereotypes and gendered expectations about role behaviour affect how knowledge and experiences are created and shared within the organization.

Social implications

The authors believe that a better understanding of knowledge handling and gendered role expectations at the workplace could also have an impact beyond organizational boundaries.

Originality/value

The paper presents the first comprehensive systematic literature review of the article published on knowledge creation, sharing and usage and gender and provides a conceptual framework for future research.
How does political skill lead to job and organization engagement? Role of self-evaluations
Authors: Basit Ameer A.
Published: June 2020

Purpose

Political skill is a valued resource employees use to achieve success. Earlier research has mostly focused on the effect of political skill on others rather than on the self of the politically skilled individuals. Specifically, there is disconnect between political skill and employee engagement research as both these fields have been growing in isolation. Drawing from theories of engagement and conservation of resources, this study bridges this gap in knowledge by investigating how political skill leads to job and organization engagement of politically skilled employees via impacting their self-evaluations of organization-based self-esteem (OBSE) and organizational identification.

Design/methodology/approach

Using a survey method, data were obtained from 188 employees who worked in three private schools of Lahore, Pakistan. Structural equation modeling was used to test the proposed model.

Findings

This study found that individuals who used political skill by practicing social astuteness, interpersonal influence, networking and sincerity rated themselves high in OBSE and organizational identification. As a consequence, high OBSE enhanced their job engagement, whereas high organizational identification increased their organization engagement.

Originality/value

This study is one of the first studies to present political skill as a driver of job and organization engagement. It reveals that the self-evaluations of OBSE and organizational identification mediate the political skill–engagement relations in unique manners.
Using plant leaders' perspectives to overcome barriers to inter-plant exchange
Authors: Wiech Michael , Friedli Thomas
Published: June 2020

Purpose

This paper sets out to identify barriers to intra-network exchange within international manufacturing networks (IMNs) from the micro-level perspective of key actors at the plant level, namely, plant leaders.

Design/methodology/approach

Data were collected through interviews with 12 plant leaders from nine different firms operating in at least three geographically dispersed manufacturing facilities.

Findings

Six partially interrelated barriers to intra-network exchange were identified. First, there are a lack of resources, network strategies, plant overlap and individual-level ties between plant leaders. Furthermore, this study shows that the pronounced local focus of plant leaders, fierce inter-plant competition and falsely designed incentives constitute barriers to inter-plant exchange. The results underline the need for network management to consider the individual-level perspective when designing rules and policies for IMNs.

Research limitations/implications

The generalisability of the results is limited by the sample, which consists of plant leaders from firms headquartered in German-speaking areas.

Practical implications

The findings indicate that network managers should consider the interests and concerns of plant leaders when trying to facilitate network thinking. In addition to delayering the overall IMN into distinct subnetworks of peer plants, network managers should set clear and openly communicated objectives in a mission for each subnetwork that also points to inter-plant exchange and provides the resources for such activities. Practitioners should also apply shared objectives for plant leaders and promote individual-level ties between them to benefit from intra-network exchange.

Originality/value

By analysing the perceptions of plant leaders, this study sheds light on the individual level of global operations, which has been neglected in research on IMNs to date.
Life cycle cost analysis of a computerized numerical control machine tool: a case study from Indian manufacturing industry
Authors: Patil Rajkumar Bhimgonda , Kothavale Basavraj S. , Waghmode Laxman Yadu , Pecht Michael
Published: June 2020

Purpose

Life cycle cost (LCC) analysis is one of the key parameters in designing a sustainable product or system. The application of life cycle costing in the manufacturing industries is still limited due to several factors. Lack of understanding of LCC analysis methodologies is one of the key barriers. This paper presents a generalized framework for LCC analysis of repairable systems using reliability and maintainability principles.

Design/methodology/approach

The developed LCC analysis framework and stochastic point processes are applied for the analysis of a typical computerized numerical control turning center (CNCTC) and governing equations for acquisition cost, operation cost, failure cost, support cost and net salvage value are developed. The LCC of the CNCTC is evaluated for the renewal process (RP) and minimal repair process (MRP) approach.

Findings

The LCC analysis of the CNCTC reveals that, the acquisition cost is only 7.59% of the LCC, whereas the operation, failure and support costs dominate and contribute nearly 93% of the LCC. The LCC per day for RP requires additional US$ 1.03 than that for MRP. The detailed LCC analysis of the CNCTC identifies the critical components of CNCTC and these components are: spindle motor, spindle motor cooling fan, spindle belt, drawbar, spindle bearing, oil seals, hydraulic hose, solenoid valve, tool holder, lubrication pump motor system, lubrication hose, coolant pump motor system, coolant hose, supply cables, drive battery.

Originality/value

The developed framework of LCC of a repairable system can be applied to any other repairable systems with the appropriate modifications. LCC analysis of CNCTC reveals that the procurement decision of a product or system should be based on LCC and not only on the acquisition cost. The optimum utilization of consumables such as cutting tools, coolant, oil and lubricant can save operation cost. Thus, use of high-efficiency electric motors and the usage of recommended consumables can prolong the life of several components of a system. Therefore, due consideration and attention to these parameters at product design stage itself will decrease failure and support cost and ultimately its LCC.
Determinants and dimensions of the shift in Turkish behavior towards northern Syria since 2016
Authors: Gadelmola Mona Soliman
Published: June 2020

Purpose

The escalation of Turkish intervention in Arab internal affairs before and after the revolutions of the Arab Spring, particularly the military intervention. Sometimes Ankara threatens with military intervention and sometimes establishes large military bases in Arab countries: Qatar, Somalia and Iraq. Moreover, it carries out extensive military operations within the borders of some Arab countries such as Iraq and Syria. This type of behavior requires a study that takes into consideration the reasons of such behavior and future implications on the relations between the Arab and Turkish parties.

Design/methodology/approach

The theoretical framework of the study will follow neorealism, as the basis for understanding Turkish pragmatic foreign policy adopted in managing its international relations and interests with various countries.

Findings

The situation in Afrin after a year of Turkish occupation confirms this. Erdogan may not go ahead with a new military operation in east Euphrates and northern Syria. He may prefer instead he may deem it better to control the safe area in the north through the revival of the agreement of Adana of 1998. However, Turkey's desire to control northern Syria, which represents a quarter of the country, faces tough resistance of Turkish groups, Russian-Syrian rejection and European-American resentment. Control of the Syrian north may be subject to concessions and consensus among these powers without excluding any of them.

Research limitations/implications

States in the international system, such as companies in the local economy, have the same main interest: that’s survival. It is worth noting that Waltz’s neorealistic theory cannot be applied to domestic national politics. It cannot contribute to the development of state policies relating to its international and internal affairs. His theory only helps to explain the reason behind the similar behavior of countries despite having different forms of governments and diversity of political ideologies. It also explains why the comprehensive international relations have not changed despite the growing decentralization of these countries.

Originality/value

How does neorealism explain Turkish military intervention in Syria since 2016?
High haplotype diversity with fine‐scale structure in a recently established population of an endangered orchid
Authors: Duffy Karl J. , Cafasso Donata , Ren Ming‐Xun , Cozzolino Salvatore
Published: June 2020

New populations of endangered plants may establish outside of protected areas if a suitable habitat becomes available. However, it is unclear whether such populations are genetically uniform, as a result of a founder effect, or whether they contain genetic variation resulting from continuous gene flow from source populations, and subsequent recruitment after establishment. We addressed this by examining haplotype variation in the endangered orchid, Anacamptis robusta, which has formed a new population outside of its protected area within the past 20 years. To assess population growth, the number of A. robusta flowering plants were counted every year for 22 years in both the new population and populations within the reserve. Haplotype diversity and fine‐scale structure were examined with spatial autocorrelation analysis, both in the new population and representative populations from the protected area. The number of flowering individuals in the new population increased from 9 to 2,277 between 2003 and 2012, whereas within the reserve flowering population sizes varied between years. Seventeen of 23 haplotypes detected for A. robusta were detected in the new population, with seven of these occurring more frequently in the new population than reserve populations. In the new population, there was strong fine‐scale spatial structure of haplotypes, similar to patterns found in large populations from the protected area, suggesting multiple colonization events and subsequent local recruitment. This highlights that ongoing demographic and genetic monitoring of plant populations is vital to improve our understanding of population colonization and the conservation of narrow endemics.
Maternal transmission of SARS‐COV‐2 to the neonate, and possible routes for such transmission: a systematic review and critical analysis
Authors: Walker KF , O'Donoghue K , Grace N , Dorling J , Comeau JL , Li W , Thornton JG
Published: June 2020

Background

Early reports of COVID‐19 in pregnancy described management by caesarean, strict isolation of the neonate and formula feeding. Is this practice justified?

Objective

To estimate the risk of the neonate becoming infected with SARS‐CoV‐2 by mode of delivery, type of infant feeding and mother‐infant interaction.

Search strategy

Two biomedical databases were searched between September 2019 and June 2020.

Selection criteria

Case reports or case series of pregnant women with confirmed COVID‐19, where neonatal outcomes were reported.

Data collection and analysis

Data were extracted on mode of delivery, infant infection status, infant feeding and mother–infant interaction. For reported infant infection, a critical analysis was performed to evaluate the likelihood of vertical transmission.

Main results

Forty nine studies included information on mode of delivery and infant infection status for 655 women and 666 neonates. In all, 28/666 (4%) tested positive postnatally. Of babies born vaginally, 8/292 (2.7%) tested positivecompared with 20/374 (5.3%) born by Caesarean. Information on feeding and baby separation were often missing, but of reported breastfed babies 7/148 (4.7%) tested positive compared with 3/56 (5.3%) for reported formula fed ones. Of babies reported as nursed with their mother 4/107 (3.7%) tested positive, compared with 6/46 (13%) for those who were reported as isolated.

Conclusions

Neonatal COVID‐19 infection is uncommon, rarely symptomatic, and the rate of infection is no greater when the baby is born vaginally, breastfed or remains with the mother.

Tweetable abstract

Risk of neonatal infection with COVID‐19 by delivery route, infant feeding and mother‐baby interaction.
Detection of toxins involved in foodborne diseases caused by Gram‐positive bacteria
Authors: Rajkovic Andreja , Jovanovic Jelena , Monteiro Silvia , Decleer Marlies , Andjelkovic Mirjana , Foubert Astrid , Beloglazova Natalia , Tsilla Varvara , Sas Benedikt , Madder Annemieke , De Saeger Sarah , Uyttendaele Mieke
Published: June 2020

Bacterial toxins are food safety hazards causing about 10% of all reported foodborne outbreaks in Europe. Pertinent to Gram‐positive pathogens, the most relevant toxins are emetic toxin and diarrheal enterotoxins ofBacillus cereus, neurotoxins ofClostridium botulinum, enterotoxin ofClostridium perfringens, and a family of enterotoxins produced byStaphylococcus aureusand some other staphylococci. These toxins are the most important virulence factors of respective foodborne pathogens and a primary cause of the related foodborne diseases. They are proteins or peptides that differ from each other in their size, structure, toxicity, toxicological end points, solubility, and stability, types of food matrix to which they are mostly related to. These differences influence the characteristics of required detection methods. Therefore, detection of these toxins in food samples, or detection of toxin production capacity in the bacterial isolate, remains one of the cornerstones of microbial food analysis and an essential tool in understanding the relevant properties of these toxins. Advanced research has led into new insights of the incidence of toxins, mechanisms of their production, their physicochemical properties, and their toxicological mode of action and dose‐response profile. This review focuses on biological, immunological, mass spectrometry, and molecular assays as the most commonly used detection and quantification methods for toxins ofB. cereus, C. botulinum, C. perfringens, andS. aureus. Gathered and analyzed information provides a comprehensive blueprint of the existing knowledge on the principles of these assays, their application in food safety, limits of detection and quantification, matrices in which they are applicable, and type of information they provide to the user.
Genomic basis of environmental adaptation in the leathery sea squirt (Styela clava)
Authors: Wei Jiankai , Zhang Jin , Lu Qiongxuan , Ren Ping , Guo Xin , Wang Jing , Li Xiang , Chang Yaoguang , Duan Shuai , Wang Shi , Yu Haiyan , Zhang Xiaoming , Yang Xiuxia , Gao Hongwei , Dong Bo
Published: June 2020

Tunicates occupy the evolutionary position at the boundary of invertebrates and vertebrates. It exhibits adaptation to broad environmental conditions and is distributed globally. Despite hundreds of years of embryogenesis studies, the genetic basis of the invasive habits of ascidians remains largely unknown. The leathery sea squirt, Styela clava, is an important invasive species. We used the chromosomal‐level genome and transcriptome of S. clava to explore its genomic‐ and molecular‐network‐based mechanisms of adaptation to environments. Compared with Ciona intestinalis type A (C. robusta), the size of the S. clava genome was expanded by 2‐fold, although the gene number was comparable. An increase in transposon number and variation in dominant types were identified as potential expansion mechanisms. In the S. clava genome, the number of genes encoding the heat‐shock protein 70 family and members of the complement system was expanded significantly, and cold‐shock protein genes were transferred horizontally into the S. clava genome from bacteria. The expanded gene families potentially play roles in the adaptation of S. clava to its environments. The loss of key genes in the galactan synthesis pathway might explain the distinct tunic structure and hardness compared with the ascidian Ciona species. We demonstrated further that the integrated thyroid hormone pathway participated in the regulation of larval metamorphosis that provides S. clava with two opportunities for adapting to their environment. Thus, our report of the chromosomal‐level leathery sea squirt genome provides a comprehensive genomic basis for the understanding of environmental adaptation in tunicates.
The Integration of Farmers and Nomads: Archaeological Evidence for the Human Subsistence Strategy in Northwestern China during the Han Dynasty
Authors: LI Xin , LU Minxia , CUI Yifu , LIU Ruiliang , MA Minmin
Published: June 2020

The integration of farmers and nomads in northwestern China during the Han Dynasty (206 BCE ~ 220 CE) provides a crucial opportunity to reconstruct the material exchanges, formation and development of the Silk Road in antiquity. The subsistence strategy is arguably an effective proxy for the integration of various groups of people (e.g. farmers and nomads). In this paper, we have reported new stable isotope data from the Huangwan tombs dated to the Han dynasty in middle Gansu, which was the key juncture between the Han and Xiongnu empire, in order to fill the gap and further understand the substance strategies employed by the local people. According to the results of plant remains and stable isotopic data, millet farming, the typical agricultural activities for the Han Chinese in the Central Plains, was also the primary lifestyle for the Huangwan people in the mid Gansu. More importantly, this shows fundamentally remarkable difference from the agricultural practices in the Bronze Age Gansu Corridor, which were based on a variety of crops, including wheat, barley and millet. This major shift in the subsistence production at Huangwan can be correlated to a wider historical background in which the Han empire showed increasing political and military presence in the Gansu Corridor, indicating that local indigenous nomads followed the lifestyle of Han Chinese (e.g., millet farming), and/or the Han immigrates maintained millet farming.
Hydrological Variations and the Ancient Silk Road in the Northern Tarim Basin between Han and Sui Dynasties
Authors: LÜ Fenglin , ZHANG Hua , HOU Juzhi , CAO Xianyong , LIU Chenglin
Published: June 2020

The fluctuation pattern of China's civilization can be ascribed to climate change and historical geopolitical variations. The ancient Silk Road served as the most prosperous route connecting East Asia and Europe during Han Dynasty (206 BC–220 AD) and Sui‐Tang Dynasties (581–907 AD), but was deserted in Wei, Jin, Northern and Southern dynasties (220–580 AD), of which the Tarim Basin was a key area. However, our understanding about the decline of the route during this period remains limited. Here, we present an ~7‐year resolution record based on optically stimulated luminescence (OSL) age‐depth model (ca. 120 BC–750AD) from Luntai (LT) profile, about 5 km from the modern Tarim River, which fed the ancient oases, to assess the potential causes on the documented decline of the ancient Silk Road between Late Han and Sui dynasties. In this study, five episodes of hydrological change were identified by combining grain size, magnetic susceptibility, geochemistry and TOC/TN contents. Our reconstruction reveals that cold and wet climate dominated at 120BC–50 AD and 550–750AD, respectively, indicated by strong hydrodynamic conditions. Relatively warm and humid climate occurred at 120–550AD, between Eastern Han and Sui‐Tang dynasties, indicating a better and more suitable local environment. A comparison between the studied region and other areas of China demonstrates that the paleoclimatic variations in eastern and western China exhibit rough discrepancies, and the hydrological conditions in arid region is inconsistent with the decline of ancient Silk Road in the northern Tarim Basin. We suggest that political and societal factors are the key issues that caused the interruption of Silk Road during Wei, Jin, Northern and Southern dynasties, such as the co‐occurrence of societal crises, turmoil and division in eastern China, rather than the deteriorating climatic condition in the northern Tarim basin.
Quality control for modern bone collagen stable carbon and nitrogen isotope measurements
Authors: Guiry Eric J. , Szpak Paul
Published: June 2020

Isotopic analyses of collagen, the main protein preserved in subfossil bone and tooth, has long provided a powerful tool for the reconstruction of ancient diets and environments. Although isotopic studies of contemporary ecosystems have typically focused on more accessible tissues (e.g. muscle, hair), there is growing interest in the potential for analyses of collagen because it is often available in hard tissue archives (e.g. scales, skin, bone, tooth), allowing for enhanced long‐term retrospective studies. The quality of measurements of the stable carbon and nitrogen isotopic compositions of ancient samples is subject to robust and well‐established criteria for detection of contaminants and diagenesis. Among these quality control (QC) criteria, the most widely utilized is the atomic C:N ratio (C:NAtomic), which for ancient samples has an acceptable range between 2.9 and 3.6. While this QC criterion was developed for ancient materials, it has increasingly being applied to collagen from modern tissues.

Here, we use a large survey of published collagen amino acid compositions (n = 436) from 193 vertebrate species as well as recent experimental isotopic evidence from 413 modern collagen extracts to demonstrate that the C:NAtomic range used for ancient samples is not suitable for assessing collagen quality of modern and archived historical samples.

For modern tissues, collagen C:NAtomic falling outside 3.00–3.30 for fish and 3.00–3.28 for mammals and birds can produce systematically skewed isotopic compositions and may lead to significant interpretative errors. These findings are followed by a review of protocols for improving C:NAtomic criteria for modern collagen extracts.

Given the tremendous conservation and environmental policy‐informing potential that retrospective isotopic analyses of collagen from contemporary and archived vertebrate tissues have for addressing pressing questions about long‐term environmental conditions and species behaviours, it is critical that QC criteria tailored to modern tissues are established.