bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional signature of conversion in Mild Cognitive Impairment patients
Authors: Pizzi Stefano Delli , Punzi Miriam , Sensi Stefano L ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: March 2018

The entorhinal-hippocampal circuit is a strategic hub for memory but also the first site to be affected in the Alzheimer’s Disease (AD)-related pathology. We investigated MRI patterns of brain atrophy and functional connectivity in a study cohort obtained from the Alzheimer’s Disease Neuroimaging Initiative database including healthy control (HC), Mild Cognitive Impairment (MCI), and AD subjects. MCI individuals were clinically evaluated 24 months after the MRI scan, and the group further divided into a subset of subjects who either did (c-MCI) or did not (nc-MCI) convert to AD. Compared to HC subjects, AD patients exhibited a collapse of long-range connectivity from the hippocampus and entorhinal cortex, pronounced cortical/sub-cortical atrophy, and a dramatic decline in cognitive performances. c-MCI patients showed entorhinal and hippocampal hypo-connectivity, no signs of cortical thinning but evidence of right hippocampus atrophy. On the contrary, nc-MCI patients showed lack of brain atrophy, largely preserved cognitive functions, hippocampal and entorhinal hyper-connectivity with selected neocortical/sub-cortical regions mainly involved in memory processing and brain meta-stability. This hyper-connectivity can represent an early compensatory strategy to overcome the progression of cognitive impairment. This functional signature can also be employed for the diagnosis of c-MCI subjects.
Imaging the evolution of visual specializations in fungus gnats
Authors: Taylor Gavin J. , Hall Stephen A. , Gren Johan A. , Baird Emily
Published: March 2018

Many insects use vision to inform their behavior, but visual information differs between habitats and the sensory demands vary with each species’ ecology. The small size of insects’ eyes constrains their optical performance, and so it is unsurprising that they have evolved specializations for optimizing the information they obtain from their habitat. Unraveling how behavioral, environmental, and phylogenetic factors influence the evolution of such specializations is difficult, however, because existing techniques to analyze insect eyes require specimens to be preserved beforehand. To facilitate broad comparative studies on insect eyes and the evolution of complex visual behavior, we developed a novel analysis technique that uses x-ray micro-computed tomography to quantify and recreate the visual world of insects. We use our methodology to investigate the eyes of fungus gnats (Orfeliini), a tribe of diminutive Dipterans, to identify the visual specializations they evolved for surviving in different forest habitats and to explore how this changed over 30 million years of evolutionary history. The specimens we studied were preserved in different ways (in ethanol, air dried, and as an endocast in amber), demonstrating that our method provides a new opportunity to quantitatively study and compare the vision of a wide range insects held in museum collections. Our analysis indicates that different visual specializations have evolved between fungus gnat species living in different forest types and that the eyes of gnats from a similar geographic location have evolved to match the changing environmental conditions. Despite the small size of fungus gnats, evolution has evidentially been able to exploit sensory specializations to meet the differing sensory demands of species from a variety of forest habitats.

Significance statement

Do insects have visual specializations that evolve with changes in their environment? To answer this question, a novel analysis technique is described that uses 3D imaging and simulations to compare the vision of ancient amber-embedded insects to those of their extant relatives. This study investigated the vision of fungus gnats to understand how tiny insects use vision to negotiate forests, some of the world’s most visually complex environments. Despite being amongst the smallest of any flying insect, the gnats’ miniature eyes have evolved visual specializations specifically adapted for different forest types, allowing different species to meet their visual demands of their specific habitats.
Achilles Tendon Structure Differs Between Runners And Non-Runners Despite No Clinical Signs Or Symptoms Of Mid-Substance Tendinopathy
Authors: Hullfish Todd J. , Hagan Kenton L. , Casey Ellen , Baxter Josh R.
Published: March 2018

Achilles tendinopathy affects many running athletes and often leads to chronic pain and functional deficits. While changes in tendon structure have been linked with tendinopathy, the effects of distance running on tendon structure is not well understood. Therefore, the purpose of this study was to characterize structural differences in the Achilles tendons in healthy young adults and competitive distance runners using quantitative ultrasound analyses. We hypothesized that competitive distance runners with no clinical signs or symptoms of tendinopathy would have quantitative signs of tendon damage, characterized by decreased collagen alignment and echogenicity, in addition to previous reports of thicker tendons. Longitudinal ultrasound images of the right Achilles tendon mid-substance were acquired in competitive distance runners and recreationally-active adults. Collagen organization, mean echogenicity, and tendon thickness were quantified using image processing techniques. Clinical assessments confirmed that runners had no signs or symptoms of tendinopathy and controls were only included if they had no history of Achilles tendon pain or injuries. Runner tendons were 40% less organized, 48% thicker, and 41% less echogenic compared to the control tendons (p < 0.001). Young adults engaged in competitive distance-running have structurally different tendons than recreationally-active young adults. While these structural differences have been associated with tendon damage, the lack of clinical symptoms of tendinopathy may suggest that these detected differences may either be precursors of tendinopathy development or protective adaptations to cyclic tendon loading experienced during running.
SCIΦ: Single-cell mutation identification via phylogenetic inference
Authors: Singer Jochen , Kuipers Jack , Jahn Katharina , Beerenwinkel Niko
Published: March 2018

Understanding the evolution of cancer is important for the development of appropriate cancer therapies. The task is challenging because tumors evolve as heterogeneous cell populations with an unknown number of genetically distinct subclones of varying frequencies. Conventional approaches based on bulk sequencing are limited in addressing this challenge as clones cannot be observed directly. Single-cell sequencing holds the promise of resolving the heterogeneity of tumors; however, it has its own challenges including elevated error rates, allelic dropout, and uneven coverage. Here, we develop a new approach to mutation detection in individual tumor cells by leveraging the evolutionary relationship among cells. Our method, called SCIΦ, jointly calls mutations in individual cells and estimates the tumor phylogeny among these cells. Employing a Markov Chain Monte Carlo scheme we robustly account for the various sources of noise in single-cell sequencing data. Our approach enables us to reliably call mutations in each single cell even in experiments with high dropout rates and missing data. We show that SCIΦ outperforms existing methods on simulated data and applied it to different real-world datasets, namely a whole exome breast cancer as well as a panel acute lymphoblastic leukemia dataset. Availability: https://github.com/cbg-ethz/SCIPhI
Plantarflexor Moment Arms Estimated From Tendon Excursion In Vivo Are Not Well Correlated With Geometric Measurements
Authors: Baxter Josh R , Piazza Stephen J
Published: March 2018

Geometric and tendon excursion methods have both been used extensively for estimating plantarflexor muscle moment arm in vivo. Geometric measures often utilize magnetic resonance imaging, which can be costly and impractical for many investigations. Estimating moment arm from tendon excursion measured with ultrasonography may provide a cost-effective alternative to geometric measures of moment arm, but how well such measures represent geometry-based moment arms remains in question. The purpose of this study was to determine whether moment arms from tendon excursion can serve as a surrogate for moment arms measured geometrically. Magnetic resonance and ultrasound imaging were performed on 19 young male subjects to quantify plantarflexor moment arm based on geometric and tendon excursion paradigms, respectively. These measurements were only moderately correlated (R2 = 0.21, p = 0.052), and moment arm from tendon excursion under-approximated geometric moment arm by nearly 40% (p < 0.001). This moderate correlation between methods is at odds with a prior report (N = 9) of a very strong correlation (R2 = 0.94) in a similar study. Therefore, we performed 92,378 regression analyses (19 choose 9) to determine if such a strong correlation existed in our study population. We found that certain sub-populations of the current study generated similarly strong coefficients of determination (R2 = 0.92), but 84% of all analyses revealed no correlation (p > 0.05). Our results suggest that the moment arms from musculoskeletal geometry cannot be otherwise obtained by simply scaling moment arms estimated from tendon excursion.
A day in the life of chromatin: how enhancer–promoter loops shape daily behavior
Authors: Weidemann Benjamin J. , Ramsey Kathryn Moynihan , Bass Joseph
Published: March 2018

Each spring, we get out of bed 1 h ahead of our biological wake-up time due to the misalignment of internal clocks with the light–dark cycle. Genetic discoveries revealed that clock genes encode transcription factors that are expressed throughout many tissues, yet a gap has remained in understanding the temporal dynamics of transcription. Two groups now apply circular chromosome conformation capture and high-throughput sequencing to dissect how “time of day”-dependent changes in chromatin drive core clock oscillations. A surprise is the finding that disruption of enhancer–promoter contacts within chromatin leads to an advance in the “wake-up” time of mice. Furthermore, the assembly of transcriptionally active domains of chromatin requires the ordered recruitment of core clock transcription factors each day. These studies show that waking up involves highly dynamic changes in the three-dimensional positioning of genes within the cell.
RABDAM: quantifying specific radiation damage in individual protein crystal structures
Authors: Shelley Kathryn L. , Dixon Thomas P. E. , Brooks-Bartlett Jonathan C. , Garman Elspeth F.
Published: March 2018

Radiation damage remains one of the major limitations to accurate structure determination in protein crystallography (PX). Despite the use of cryo-cooling techniques, it is highly probable that a number of the structures deposited in the Protein Data Bank (PDB) have suffered substantial radiation damage as a result of the high flux densities of third generation synchrotron X-ray sources. Whereas the effects of global damage upon diffraction pattern reflection intensities are readily detectable, traditionally the (earlier onset) site-specific structural changes induced by radiation damage have proven difficult to identify within individual PX structures. More recently, however, development of the B
Damage metric has helped to address this problem. B
Damage is a quantitative, per-atom metric identifies potential sites of specific damage by comparing the atomic B-factor values of atoms that occupy a similar local packing density environment in the structure. Building upon this past work, this article presents a program, RABDAM, to calculate the B
Damage metric for all selected atoms within any standard-format PDB or mmCIF file. RABDAM provides several useful outputs to assess the extent of damage suffered by an input PX structure. This free and open-source software will allow assessment and improvement of the quality of PX structures both previously and newly deposited in the PDB.
Pitfalls and reproducibility ofin situsynchrotron powder X-ray diffraction studies of solvothermal nanoparticle formation
Authors: Andersen Henrik L. , Bøjesen Espen D. , Birgisson Steinar , Christensen Mogens , Iversen Bo B.
Published: March 2018

In situpowder X-ray diffraction (PXRD) is a powerful characterization tool owing to its ability to provide time-resolved information about phase composition, crystal structure and microstructure. The application of high-flux synchrotron X-ray beams and the development of custom-built reactors have facilitated second-scale time-resolved studies of nanocrystallite formation and growth during solvothermal synthesis. The short exposure times required for good time resolution limit the data quality, while the employed high-temperature–high-pressure reactors further complicate data acquisition and treatment. Based on experience gathered during ten years of conductingin situstudies of solvothermal reactions at a number of different synchrotrons, a compilation of useful advice for conductingin situPXRD experiments and data treatment is presented here. In addition, the reproducibility of the employed portablein situPXRD setup, experimental procedure and data analysis is evaluated. This evaluation is based on repeated measurements of an LaB6line-profile standard throughout 5 d of beamtime and on the repetition of ten identicalin situsynchrotron PXRD experiments on the hydrothermal formation of γ-Fe2O3nanocrystallites. The study reveals inconsistencies in the absolute structural and microstructural values extracted by Rietveld refinement and whole powder pattern modelling of thein situPXRD data, but also illustrates the robustness of trends and relative changes in the extracted parameters. From the data, estimates of the effective errors and reproducibility ofin situPXRD studies of solvothermal nanocrystallite formation are provided.
First-principles X-ray absorption dose calculation for time-dependent mass and optical density
Authors: Berejnov Viatcheslav , Rubinstein Boris , Melo Lis G. A. , Hitchcock Adam P.
Published: March 2018

A dose integral of time-dependent X-ray absorption under conditions of variable photon energy and changing sample mass is derived from first principles starting with the Beer–Lambert (BL) absorption model. For a given photon energy the BL dose integralD(e, t) reduces to the product of an effective time integralT(t) and a dose rateR(e). Two approximations of the time-dependent optical density,i.e.exponentialA(t) =c+aexp(−bt) for first-order kinetics and hyperbolicA(t) =c+a/(b+t) for second-order kinetics, were considered for BL dose evaluation. For both models three methods of evaluating the effective time integral are considered: analytical integration, approximation by a function, and calculation of the asymptotic behaviour at large times. Data for poly(methyl methacrylate) and perfluorosulfonic acid polymers measured by scanning transmission soft X-ray microscopy were used to test the BL dose calculation. It was found that a previous method to calculate time-dependent dose underestimates the dose in mass loss situations, depending on the applied exposure time. All these methods here show that the BL dose is proportional to the exposure timeD(e, t) ≃K(e)t.
XFEL experiments: jitter of pump–probe time delays and pulse intensities
Authors: Bratos S. , Wulff M. , Leicknam J.-Cl.
Published: March 2018

Jitter of XFEL signals due to fluctuations in shot-to-shot time delays and intensities are explored in the frame of a statistical theory of X-ray diffraction from liquids. Deformed signals are calculated at different levels of pump–probe jitter. A new method is proposed to eliminate these distortions.
The structures of 1,4-diaryl-5-trifluoromethyl-1H-1,2,3-triazoles related to J147, a drug for treating Alzheimer's disease
Authors: Farrán M. Ángeles , Bonet M. Ángels , Claramunt Rosa M. , Torralba M. Carmen , Alkorta Ibon , Elguero José
Published: March 2018

J147 [N-(2,4-dimethylphenyl)-2,2,2-trifluoro-N′-(3-methoxybenzylidene)acetohydrazide] has recently been reported as a promising new drug for the treatment of Alzheimer's disease. The X-ray structures of seven new 1,4-diaryl-5-trifluoromethyl-1H-1,2,3-triazoles, namely 1-(3,4-dimethylphenyl)-4-phenyl-5-trifluoromethyl-1H-1,2,3-triazole (C17H14F3N3, 1), 1-(3,4-dimethylphenyl)-4-(3-methoxyphenyl)-5-trifluoromethyl-1H-1,2,3-triazole (C18H16F3N3O, 2), 1-(3,4-dimethylphenyl)-4-(4-methoxyphenyl)-5-trifluoromethyl-1H-1,2,3-triazole (C18H16F3N3O, 3), 1-(2,4-dimethylphenyl)-4-(4-methoxyphenyl)-5-trifluoromethyl-1H-1,2,3-triazole (C18H16F3N3O, 4), 1-[2,4-bis(trifluoromethyl)phenyl]-4-(3-methoxyphenyl)-5-trifluoromethyl-1H-1,2,3-triazole (C18H10F9N3O, 5), 1-(3,4-dimethoxyphenyl)-4-(3,4-dimethoxyphenyl)-5-trifluoromethyl-1H-1,2,3-triazole (C19H18F3N3O4, 6) and 3-[4-(3,4-dimethoxyphenyl)-5-(trifluoromethyl)-1H-1,2,3-triazol-1-yl]phenol (C17H14F3N3O3, 7), have been determined and compared to that of J147. B3LYP/6-311++G(d,p) calculations have been performed to determine the potential surface and molecular electrostatic potential (MEP) of J147, and to examine the correlation between hydrazone J147 and the 1,2,3-triazoles, both bearing a CF3 substituent. Using MEPs, it was found that the minimum-energy conformation of 4, which is nearly identical to its X-ray structure, is closely related to one of the J147 seven minima.
The crystal structure of the drug targetMycobacterium tuberculosismethionyl-tRNA synthetase in complex with a catalytic intermediate
Authors: Barros-Álvarez Ximena , Turley Stewart , Ranade Ranae M. , Gillespie J. Robert , Duster Nicole A. , Verlinde Christophe L. M. J. , Fan Erkang , Buckner Frederick S. , Hol Wim G. J.
Published: March 2018

Mycobacterium tuberculosisis a pathogenic bacterial infectious agent that is responsible for approximately 1.5 million human deaths annually. Current treatment requires the long-term administration of multiple medicines with substantial side effects. Lack of compliance, together with other factors, has resulted in a worrisome increase in resistance. New treatment options are therefore urgently needed. Here, the crystal structure of methionyl-tRNA synthetase (MetRS), an enzyme critical for protein biosynthesis and therefore a drug target, in complex with its catalytic intermediate methionyl adenylate is reported. Phenylalanine 292 of theM. tuberculosisenzyme is in an `out' conformation and barely contacts the adenine ring, in contrast to other MetRS structures where ring stacking occurs between the adenine and a protein side-chain ring in the `in' conformation. A comparison with human cytosolic MetRS reveals substantial differences in the active site as well as regarding the position of the connective peptide subdomain 1 (CP1) near the active site, which bodes well for arriving at selective inhibitors. Comparison with the human mitochondrial enzyme at the amino-acid sequence level suggests that arriving at inhibitors with higher affinity for the mycobacterial enzyme than for the mitochondrial enzyme might be achievable.
Triple-down model of capability, job characteristics and burnout
Authors: Nguyen Thuy Thi Thanh , Chang Man-Ling
Published: March 2018

Purpose

A Chinese proverb states: “Able people should do more work.” Although working hard is a common workplace phenomenon, does it lead to burnout in capable people? This study aims to examine the interactive effects of superior-perceived capability and subordinates’ self-efficacy on subordinate job demands, job involvement and burnout in frontline employees in the hospitality industry.

Design/methodology/approach

Data on 41 superiors and 161 subordinates from 16 hotels in Taiwan were collected. Hierarchical linear modeling is used to examine the research hypotheses.

Findings

The findings support the hypothesis that self-efficacy leads to high levels of burnout and job involvement. However, superior-perceived capability has no impact on subordinate job demand, job involvement or burnout. While job demands are positively related to the emotional exhaustion of burnout, job involvement is negatively related to depersonalization of burnout. In addition, job involvement partially mediates the relationship between self-efficacy and depersonalization of burnout.

Originality/value

Based on the job demands–resources theory, this study reveals the fresh point of view for the effect of self-efficacy on burnout. This paper explores the dark-side role of self-efficacy for burnout – higher self-efficacy leads to higher burnout – that is contrary to the findings from previous studies and hinges on Chinese cultural values. In addition, the current study provides guidelines for top managers to protect capable employees from burnout by enhancing intrinsic motivation and job involvement.
Critical success factors for ERP system implementation: a user perspective
Authors: Reitsma Ewout , Hilletofth Per
Published: March 2018

Purpose

The purpose of this study is to evaluate critical success factors (CSFs) for the implementation of an enterprise resource planning (ERP) system from a user perspective.

Design/methodology/approach

The research was conducted in two successive steps. First, a literature review was conducted to derive CSFs for ERP system implementation. Second, a survey was conducted to evaluate the importance of these CSFs from a user perspective. Data were collected through a questionnaire that was distributed within a German manufacturer and was developed based on the CSFs found in the literature. Gray relational analysis (GRA) was used to rank the CSFs in order of importance from a user perspective.

Findings

The findings reveal that users regard 11 of the 13 CSFs found in the literature as important for ERP system implementation. Seven of the CFSs were classified as the most important from a user perspective, namely, project team, technical possibilities, strategic decision-making, training and education, minimum customization, software testing and performance measurement. Users regarded 2 of the 13 CSFs as not important when implementing an ERP system, including organizational change management and top management involvement.

Research limitations/implications

One limitation of this study is that the respondents originate from one organization, industry and country. The findings may differ in other contexts, and thus, future research should be expanded to include more organizations, industries and countries. Another limitation is that this study only evaluates existing CSFs from a user perspective rather than identifying new ones and/or the underlying reasons using more qualitative research.

Practical implications

A better understanding of the user perspective toward CSFs for ERP system implementation promises to contribute to the design of more effective ERP systems, a more successful implementation and a more effective operation. When trying to successfully implement an ERP system, the project team may use the insights from the user perspective.

Originality/value

Even though researchers highlight the important role users play during ERP system implementation, their perspective toward the widely discussed CSFs for ERP system implementation has not been investigated comprehensively. This study aims to fill this gap by evaluating CSFs derived from the literature from a user perspective.
Exploring perceptions of customer value
Authors: Jensen Barbara , Annan-Diab Fatima , Seppala Nina
Published: March 2018

Purpose

The purpose of this paper is to develop a framework that describes and explains how corporate social responsibility (CSR) initiatives are perceived by customers and links customer perception to the notion of customer value perception. To explore customer value conception firstly, the perception of CSR initiatives is investigated; secondly, indications for the value-enhancing effects of CSR initiatives are studied, and finally, the varying effects which different value categories can have on customer attitudes and behaviour are extracted.

Design/methodology/approach

The data consists of 12 semi-structured interviews with customers of European telecommunication companies.

Findings

The results suggest that CSR initiatives, when communicated efficiently and considered as relevant by customers, will enhance two customer value categories: the extrinsic self-oriented value defined as efficiency and excellence and the intrinsic other-oriented value pertaining to ethics or spirituality. Enhancement of extrinsic self-oriented value imbeds the potential of CSR initiatives to affect customers’ purchase behaviour and thus strengthen ethical consumerism within the telecommunications industry.

Research limitations/implications

The main implication for research is a better understanding of the relationship between customer perception and customer value perception in the field of ethical consumerism. Focussing on one industry for the study can be named as a limitation.

Practical implications

As indicated by the research, results by customers prioritised CSR initiative can affect the customer value perception, mainly the extrinsic/self-oriented value. If the company is aiming to change customer behaviour and to strengthen ethical consumerism, it is important that the customer experience of CSR initiatives improve excellence (quality) and/or efficiency of the product/service.

Originality/value

This paper fulfils an identified need of research on how CSR initiatives can influence consumer behaviour.
Emotions as predictor for consumer engagement in YouTube advertisement
Authors: Kujur Fedric , Singh Saumya
Published: March 2018

Purpose

YouTube has emerged as the most innovative social networking sites (SNS) with exclusive features at that time which allowed users to post, view, comment and link to videos on the site. The purpose of this paper is to investigate the way emotional appeals are being used in YouTube advertisements to promote their products by considering various big brands of different industries in emerging market like India. The advertisement that induces consumer’s emotions can cause subconscious reactions which supersede consumer’s logical and pragmatic responses to create the unbreakable bond with a brand.

Design/methodology/approach

The study has taken online video advertisements which were uploaded on YouTube by different companies. The advertisements considered for the study were selected on three criteria: having more than 1,00,000 subscribers; videos having Indian advertisements; and have released at least one popular advertisement of minimum 1,00,000 views monthly in the period January 1-December 31, 2016. Random sampling method was used. Content analysis of 150 video advertisements was done to assess the influence of positive and negative emotions on consumer engagement. Multiple regression method is used taking the stepwise method.

Findings

The present study focused on emotional aspects of the advertisement that induce consumer engagement through SNS. The marketing strategies mainly focus on rational aspects as well as emotional aspects. The study suggests that in emerging economy like India, people heavily rely on emotions rather than logical information regarding any goods or services; hence, we considered both positive and negative emotional aspects in the study so as to measure the influence of emotional appeals on consumer engagement. Positive emotional appeals like contentment, happiness and love have the positive influence on the consumer engagement. On the other hand, negative emotional appeals are negatively related to the consumer engagement.

Originality/value

The present study aims at measuring ripple effect of the emotional appeals on ads and also tries to compare the impact between positive and negative emotional appeals so that it becomes easy for the marketers to determine the context in which it can be applied. For this purpose, YouTube video ads from India have been taken as the object of study from different industries.
Social-cultural capital in youth entrepreneurship ecosystem: Southeast Asia
Authors: Pillai Tharuma Rajan , Ahamat Amiruddin
Published: March 2018

Purpose

This paper aims to explore the contextual role of social-cultural capital in youth entrepreneurship between Malaysia and Lao PDR/Laos, comparing two different entrepreneurial ecosystems designed to identify emergent factors that stimulate and/or stifle the genesis of youth entrepreneurship while identifying similar and divergent entrepreneurial identities and traits among young people from these two sovereign contexts.

Design/methodology/approach

Utilizing qualitative-based case study design approach, data collections were garnered from 30 informants through in-depth personal interviews, focus group studies coupled with personal observation conducted via purposive cum snowball sampling.

Findings

Thematic analysis reveals a pattern-based outcome that discloses a variety of inter-related factors within the social network ecosystem that stimulate and sometimes stifle youth entrepreneurship, primarily through the active agency of social-cultural capital.

Practical implications

Entrepreneurial ecosystem contextual differences between Malaysia and Laos demonstrate the unifying factor of social-cultural capital through social network in stimulating youth entrepreneurship and unveiling practical similarities and differences that can be used to promote youth entrepreneurial endeavors among varying sovereign socio-economic contexts in ASEAN (Association of Southeast Asian Countries).

Originality/value

This study specifically focuses on the unambiguous contextual differences of two sovereign entrepreneurship ecosystems. Contextual differences may not necessarily demarcate further the gulf of differences within and between two sovereign entrepreneurship ecosystems but, on the contrary, may close the gap through the dynamic role of social-cultural capital via social network ties in youth entrepreneurship.
It takes all kinds: understanding diverse entrepreneurial ecosystems
Authors: Cowell Margaret , Lyon-Hill Sarah , Tate Scott
Published: March 2018

Purpose

This paper aims to explore the dynamics of entrepreneurial ecosystems with both rural and urban features, as well as the varied system requirements of differing types of entrepreneurs within such an ecosystem.

Design/methodology/approach

Using a mixed-methods case study approach, the study examined the Roanoke–Blacksburg region in western Virginia. Researchers conducted quantitative analysis of entrepreneurial metrics and network relationships, as well as qualitative analysis of data collected through entrepreneur surveys and stakeholder interviews.

Findings

Findings suggest entrepreneurs of different types faced disparate challenges and uneven access to resources and networks. Innovation-driven “gazelle” enterprises (IDEs) had numerous growth-related resource needs, including angel, venture and scale-up funding; prototyping equipment and facilities; and translational research by local universities. Small- and medium-sized enterprises (SMEs) required more entrepreneurial education programming, subsidized main street office space and clearer pathways through the government regulatory system. A key finding was also concerned with the different ways by which IDEs and SMEs accessed key resources within the ecosystem, illustrated through social network analysis, and supported through qualitative feedback.

Research limitations/implications

Study findings were limited by a relatively low survey response rate from some entrepreneur demographic segments, particularly minorities.

Originality/value

The study represents an in-depth, multi-methods approach that offers insight into two under-researched areas in the ecosystem literature: the dynamics of urban – rural ecosystems and the varied system requirements of different entrepreneur types. The paper includes three overarching recommendations for policy and practice: improved collection and sharing of regional metrics; differentiated approaches to entrepreneurial support based on entrepreneur type; and enhanced efforts to advance inclusive entrepreneurship.
Technology and talent: capturing the role of universities in regional entrepreneurial ecosystems
Authors: Huang-Saad Aileen , Duval-Couetil Nathalie , Park Jongho
Published: March 2018

Purpose

This paper describes the entrepreneurial ecosystems of three public research universities involved in the National Science Foundation (NSF) Midwest I-Corps TM (trademark symbol) Node. It presents a synthesis of programming, functional structure, commonly referenced university metrics and their limitations in measuring impact on commercialization and regional development.

Design/methodology/approach

Based on current literature, university data and discussions with entrepreneurship leaders at the University of Michigan/Ann Arbor, University of Illinois/Urbana Champaign and Purdue University, this paper provides an overview and analysis of entrepreneurial resources and education initiatives.

Findings

University contributions to entrepreneurial ecosystems can be described with respect to infrastructure and leadership, technology and talent and culture of innovation. Four main university entities are responsible for driving entrepreneurship initiatives. Identification of these entities, their respective activities and their outcomes allows us to propose a framework for analyzing and measuring university entrepreneurial ecosystem impact.

Practical implications

The paper describes the variety of university-based entrepreneurial initiatives believed to contribute to university entrepreneurial vibrancy and ultimately regional development. It identifies ecosystem stakeholders and provides a framework for examining their role and impact for continuous development.

Originality/value

The research complements prior reviews and empirical studies of university-wide entrepreneurial ecosystems by focusing on programming within and across institutions according to four dimensions (academic, research administration, technology transfer and community engagement) with respect to technology and talent development. It describes similarities across institutions and limitations associated with measuring impact. It provides a foundation for future empirical research related to the impact of NSF I-Corps and entrepreneurial programming in academic settings.
Gender bias in machine learning for sentiment analysis
Authors: Thelwall Mike
Published: March 2018

Purpose

The purpose of this paper is to investigate whether machine learning induces gender biases in the sense of results that are more accurate for male authors or for female authors. It also investigates whether training separate male and female variants could improve the accuracy of machine learning for sentiment analysis.

Design/methodology/approach

This paper uses ratings-balanced sets of reviews of restaurants and hotels (3 sets) to train algorithms with and without gender selection.

Findings

Accuracy is higher on female-authored reviews than on male-authored reviews for all data sets, so applications of sentiment analysis using mixed gender data sets will over represent the opinions of women. Training on same gender data improves performance less than having additional data from both genders.

Practical implications

End users of sentiment analysis should be aware that its small gender biases can affect the conclusions drawn from it and apply correction factors when necessary. Users of systems that incorporate sentiment analysis should be aware that performance will vary by author gender. Developers do not need to create gender-specific algorithms unless they have more training data than their system can cope with.

Originality/value

This is the first demonstration of gender bias in machine learning sentiment analysis.
Open bibliometrics and undiscovered public knowledge
Authors: Stuart David
Published: March 2018

Purpose

The purpose of this paper is to raise awareness of the potential of open bibliometrics, especially for the discovery of previously undiscovered public knowledge.

Design/methodology/approach

The viewpoint considers the limitations of the most popular current bibliometric tools and the possibilities offered from more open tools. It is supported by analysis of the openness of keywords associated with bibliometric studies in 2016.

Findings

The paper finds that although tools are emerging that offer more open bibliometrics, bibliometric research nonetheless continues to make use of restricted services.

Originality/value

This viewpoint on the potential of open bibliometrics is supported by an analysis of the current openness of bibliometric keywords.
Insular woody daisies (Argyranthemum, Asteraceae) are more resistant to drought‐induced hydraulic failure than their herbaceous relatives
Authors: Dória Larissa C. , Podadera Diego S. , del Arco Marcelino , Chauvin Thibaud , Smets Erik , Delzon Sylvain , Lens Frederic
Published: March 2018

Insular woodiness refers to the evolutionary transition from herbaceousness towards derived woodiness on (sub)tropical islands and leads to island floras that have a higher proportion of woody species compared to floras of nearby continents.

Several hypotheses have tried to explain insular woodiness since Darwin's original observations, but experimental evidence why plants became woody on islands is scarce at best.

Here, we combine experimental measurements of hydraulic failure in stems (as a proxy for drought stress resistance) with stem anatomical observations in the daisy lineage (Asteraceae), including insular woody Argyranthemum species from the Canary Islands and their herbaceous continental relatives.

Our results show that stems of insular woody daisies are more resistant to drought‐induced hydraulic failure than the stems of their herbaceous counterparts. The anatomical character that best predicts variation in embolism resistance is intervessel pit membrane thickness (TPM), which can be functionally linked with air bubble dynamics throughout the 3D vessel network. There is also a strong link between TPM vs. degree of woodiness and thickness of the xylem fibre wall vs. embolism resistance, resulting in an indirect link between lignification and resistance to embolism formation.

Thicker intervessel pit membranes in Argyranthemum functionally explain why this insular woody genus is more embolism resistant to drought‐induced failure compared to the herbaceous relatives from which it has evolved, but additional data are needed to confirm that palaeoclimatic drought conditions have triggered wood formation in this daisy lineage.

A plain language summary is available for this article.
Do Checklists Make a Difference? A Natural Experiment from Food Safety Enforcement
Authors: Ho Daniel E. , Sherman Sam , Wyman Phil
Published: March 2018

Inspired by Atul Gawande's bestselling Checklist Manifesto, many commentators have called for checklists to solve complex problems in law and public policy. We study a unique natural experiment to provide the first systematic evidence of checklists in law. In 2005, the Public Health Department of Seattle and King County revised its health code, subjecting half of inspection items to a checklist, with others remaining on a free‐form recall basis. Through in‐depth qualitative analysis, we identify the subset of code items that remained substantively identical across revisions, and then apply difference‐in‐differences to isolate the checklist effect in more than 95,000 inspections from 2001–2009. Contrary to scholarly and popular claims that checklists can improve the administration of law, the checklist has no detectable effect on inspector behavior. Making a violation more salient by elevating it from “noncritical” to “critical” status, however, has a pronounced effect. The benefits of checklists alone are considerably overstated.
Reviewing research priorities in weed ecology, evolution and management: a horizon scan
Authors: Neve P , Barney J N , Buckley Y , Cousens R D , Graham S , Jordan N R , Lawton‐Rauh A , Liebman M , Mesgaran M B , Schut M , Shaw J , Storkey J , Baraibar B , Baucom R S , Chalak M , Childs D Z , Christensen S , Eizenberg H , Fernández‐Quintanilla C , French K , Harsch M , Heijting S , Harrison L , Loddo D , Macel M , Maczey N , Merotto A , Mortensen D , Necajeva J , Peltzer D A , Recasens J , Renton M , Riemens M , Sønderskov M , Williams M
Published: March 2018

Weedy plants pose a major threat to food security, biodiversity, ecosystem services and consequently to human health and wellbeing. However, many currently used weed management approaches are increasingly unsustainable. To address this knowledge and practice gap, in June 2014, 35 weed and invasion ecologists, weed scientists, evolutionary biologists and social scientists convened a workshop to explore current and future perspectives and approaches in weed ecology and management. A horizon scanning exercise ranked a list of 124 pre‐submitted questions to identify a priority list of 30 questions. These questions are discussed under seven themed headings that represent areas for renewed and emerging focus for the disciplines of weed research and practice. The themed areas considered the need for transdisciplinarity, increased adoption of integrated weed management and agroecological approaches, better understanding of weed evolution, climate change, weed invasiveness and finally, disciplinary challenges for weed science. Almost all the challenges identified rested on the need for continued efforts to diversify and integrate agroecological, socio‐economic and technological approaches in weed management. These challenges are not newly conceived, though their continued prominence as research priorities highlights an ongoing intransigence that must be addressed through a more system‐oriented and transdisciplinary research agenda that seeks an embedded integration of public and private research approaches. This horizon scanning exercise thus set out the building blocks needed for future weed management research and practice; however, the challenge ahead is to identify effective ways in which sufficient research and implementation efforts can be directed towards these needs.
2D tungsten diselenide analyzed by XPS
Authors: Shallenberger Jeffrey R.
Published: March 2018

Tungsten diselenide (WSe2) was analyzed using x-ray photoelectron spectroscopy. A freshly exfoliated, oxygen-free flake was analyzed. Spectral regions for O 1s, W 4d, W 4f, W 5p, Se 3d and an extended region encompassing Se 3p, Se 3s, W 4d, Se LMM, and C 1s were acquired along with the valence band. Bulk quantitative analyses by x-ray fluorescence and x-ray diffraction indicated the material was stoichiometric and phase pure, respectively.
The ocean noise coherence matrix and its rank
Authors: Harrison Chris H.
Published: March 2018

An expression for the cross-spectral density matrix of ocean noise naturally separates into a Toeplitz part and a Hankel part [Harrison (2017). J. Acoust. Soc. Am. 141, 2812–2820]. The Toeplitz part is shown to be substantially rank-deficient for all practical acoustic cases, which has implications for adaptive beam forming. The influence of the Hankel part on passive fathometry is investigated, and its effect on adaptive beam forming is shown to be weak or negligible. Numerical demonstrations of these findings including beam patterns and eigenvalue spectra derived via circulant matrices are given based on a simple half-space with a Rayleigh reflection coefficient. Two sets of experimental data are revisited in this context, deriving eigenvalue spectra, beam patterns, and passive fathometry impulse responses with conventional and adaptive processing and differing amounts of averaging. The solution to a long-standing puzzle of processing inconsistency is suggested.
Submesoscale Rossby waves on the Antarctic circumpolar current
Authors: Taylor John R. , Bachman Scott , Stamper Megan , Hosegood Phil , Adams Katherine , Sallee Jean-Baptiste , Torres Ricardo
Published: March 2018

Submesoscale Rossby waves are found along the Antarctic circumpolar current where they drive strong vertical circulations.
Universal characteristics of particle shape evolution by bed-load chipping
Authors: Novák-Szabó Tímea , Sipos András Árpád , Shaw Sam , Bertoni Duccio , Pozzebon Alessandro , Grottoli Edoardo , Sarti Giovanni , Ciavola Paolo , Domokos Gábor , Jerolmack Douglas J.
Published: March 2018

Sediments moved by wind, rivers, and waves round in the same way due to geometry.
Organization of feed-forward loop motifs reveals architectural principles in natural and engineered networks
Authors: Gorochowski Thomas E. , Grierson Claire S. , di Bernardo Mario
Published: March 2018

We develop methods to decipher the rules controlling how small structures cluster and connect in complex networks.
Robots for the PyeongChang 2018 Winter Olympic Games
Authors: Park Hyunsub , Oh Jun-Ho
Published: March 2018

Robotic and athletic achievements shared the stage at the PyeongChang 2018 Winter Olympic Games.
Commensal orthologs of the human autoantigen Ro60 as triggers of autoimmunity in lupus
Authors: Greiling Teri M. , Dehner Carina , Chen Xinguo , Hughes Kevin , Iñiguez Alonso J. , Boccitto Marco , Ruiz Daniel Zegarra , Renfroe Stephen C. , Vieira Silvio M. , Ruff William E. , Sim Soyeong , Kriegel Christina , Glanternik Julia , Chen Xindi , Girardi Michael , Degnan Patrick , Costenbader Karen H. , Goodman Andrew L. , Wolin Sandra L. , Kriegel Martin A.
Published: March 2018

Commensal bacterial orthologs of the human autoantigen Ro60 may trigger cross-reactive T and B cells that initiate and sustain chronic autoimmunity in lupus.
Medication development in opioid addiction: Meaningful clinical end points
Authors: Volkow Nora D. , Woodcock Janet , Compton Wilson M. , Throckmorton Douglas C. , Skolnick Phil , Hertz Sharon , Wargo Eric M.
Published: March 2018

The FDA’s “abstinence” outcome measure for approval of new medications to treat opioid-use disorders has been difficult to achieve; developing and validating alternative meaningful outcomes could facilitate drug development.
Ablation of the stress protease OMA1 protects against heart failure in mice
Authors: Acin-Perez Rebeca , Lechuga-Vieco Ana Victoria , del Mar Muñoz Maria , Nieto-Arellano Rocío , Torroja Carlos , Sánchez-Cabo Fátima , Jiménez Concepción , González-Guerra Andrés , Carrascoso Isabel , Benincá Cristiane , Quiros Pedro M. , López-Otín Carlos , Castellano José María , Ruíz-Cabello Jesús , Jiménez-Borreguero Luis Jesús , Enríquez José Antonio
Published: March 2018

Loss of OMA1 protects cardiomyocytes from death in three murine models of heart failure with diverse etiologies.
A conserved transcriptional response to intranasal Ebola virus exposure in nonhuman primates prior to onset of fever
Authors: Speranza Emily , Bixler Sandra L. , Altamura Louis A. , Arnold Catherine E. , Pratt William D. , Taylor-Howell Cheryl , Burrows Christina , Aguilar William , Rossi Franco , Shamblin Joshua D. , Wollen Suzanne E. , Zelko Justine M. , Minogue Timothy , Nagle Elyse , Palacios Gustavo , Goff Arthur J. , Connor John H.
Published: March 2018

An animal model of Ebola virus infection with variable disease onset identifies host markers of infection that precede symptoms by 4 days.