bluuebunny/crossref_metadata_2025_split huggingface dataset:
The mechanical basis for snapping of the Venus flytrap, Darwin’s ‘most wonderful plant in the world’
Authors: Burri Jan T. , Saikia Eashan , Läubli Nino F. , Vogler Hannes , Wittel Falk K. , Rüggeberg Markus , Herrmann Hans J. , Burgert Ingo , Nelson Bradley J. , Grossniklaus Ueli 
Published: July 2019

ABSTRACTThe carnivorous Venus flytrap catches prey by an ingenious snapping mechanism. Based on work over the past 190 years, it has become generally accepted that two touches of the trap’s sensory hairs within 30 seconds, each one generating an action potential, are required to trigger closure of the trap. We developed an electromechanical model which, however, suggests that under certain circumstances one touch is sufficient to generate two action potentials. Using a force-sensing microrobotics system, we precisely quantified the sensory hair deflection parameters necessary to trigger trap closure, and correlated them with the elicited action potentials in vivo. Our results confirm the model’s predictions, suggesting that the Venus flytrap may be adapted to a wider range of prey movement than previously assumed.
Divergent selection and primary gene flow shape incipient speciation of a riparian tree on Hawaii Island
Authors: Choi Jae Young , Purugganan Michael , Stacy Elizabeth A. 
Published: July 2019

AbstractA long-standing goal of evolutionary biology is to understand the mechanisms underlying the formation of species. Of particular interest is whether or not speciation can occur in the presence of gene flow and without a period of physical isolation. Here, we investigated this process within HawaiianMetrosideros, a hyper-variable and highly dispersible woody species complex that dominates the Hawaiian Islands in continuous stands. Specifically, we investigated the origin ofMetrosideros polymorphavar.newellii(newellii), a riparian ecotype endemic to Hawaii Island that is purportedly derived from the archipelago-wideM. polymorphavar.glaberrima(glaberrima). Disruptive selection across a sharp forest-riparian ecotone contributes to the isolation of these varieties and is a likely driver of newellii’s origin. We examined genome-wide variation of 42 trees from Hawaii Island and older islands. Results revealed a split between glaberrima and newellii within the past 0.3-1.2 million years. Admixture was extensive between lineages within Hawaii Island and between islands, but introgression from populations on older islands (i.e.secondary gene flow) did not appear to contribute to the emergence of newellii. In contrast, recurrent gene flow (i.e.primary gene flow) between glaberrima and newellii contributed to the formation of genomic islands of elevated absolute and relative divergence. These regions were enriched for genes with regulatory functions as well as for signals of positive selection, especially in newellii, consistent with divergent selection underlying their formation. In sum, our results support riparian newellii as a rare case of incipient ecological speciation with primary gene flow in trees.Author summaryA long-standing question in evolution is whether or not new species can arise in the presence of gene flow, which is expected to inhibit the formation of reproductive isolating barriers. We investigated the genomics underlying the origin of a Hawaii Island-endemic riparian tree and purported case of incipient sympatric speciation due to disruptive selection across a sharp forest-riparian ecotone. We find extensive evidence of ongoing gene flow between the riparian tree and its closest relative along with local genomic regions resistant to admixture that likely formed through selection on genes for ecological adaptation and/or reproductive isolation. These results strongly suggest that where disruptive selection is strong, incipient speciation with gene flow is possible even in long-lived, highly dispersible trees.
Functional activity of antisera against recombinant Zika virus envelope protein subunits expressed in Escherichia coli
Authors: Tham Hong-Yun , Ooi Man Kwan , Balasubramaniam Vinod RMT , Hassan Sharifah Syed , Tham Hong-Wai 
Published: July 2019

AbstractThe global Zika virus (ZIKV) outbreak across continents has been drawing research attentions to researchers and healthcare professionals. It highlights the urgent development of ZIKV vaccines that offer rapid, precise and specific protection to those living in the high-risk regions - the tropical and subtropical regions. As a public health priority, there is a progressive development in the discovery of vaccine candidates and design in recent years. Many efforts have been placed in the in vitro development of ZIKV subunits as the vaccine candidate in various protein expression systems, including bacteria, yeast, plant cells, insect cells and mammalian cells. However, due to the lack of knowledge on humoral and cellular immune responses against virus vaccines, a commercialised vaccine against Dengue virus (DENV) has been suspended due to a health scare in Philippines. Moreover, the closely-related DENV and ZIKV has indicated serological cross-reactivity between both viruses. This has led to greater attentions to precautions needed during the design of ZIKV and DENV vaccines. In this study, we pre-selected, synthesised and expressed the domain III of ZIKV envelope protein (namely rEDIII) based on a previously-established report (GenBank: AMC13911.1). The characteristics of purified ZIKV rEDIII was tested using SDS-PAGE, Western blotting and LC-MS/MS. Since the ZIKV rEDIII has been well reported as a potential protein candidate in ZIKV vaccine development, we assessed the possible outcome of preexisting immunity against the rEDIII proteins by conducting dot-blotting assays using mice antisera pre-immunised with ZIKV particles (ZIKV strain: MRS_OPY_Martinique_PaRi_2015, GenBank: KU647676) . Surprisingly, the antisera was able to recognise the rEDIII of a different ZIKV strain (GenBank: AMC13911.1). Despite its great antigenicity in eliciting humoral and cellular immunity against ZIKV infection, our finding calls for greater attention to evaluate the details of ZIKV rEDIII as a stand-alone vaccine candidate.
Production, purification and evaluation of biodegrading potential of PHB depolymerase ofStenotrophomonassp. RZS 7
Authors: Sayyed R. Z. , Wani S. J. , Al-Harthi Helal F. , Syed Asad , El-Enshasy Hesham Ali 
Published: July 2019

AbstractThere are numerous reports on PHB depolymerases produced by a wide variety of microorganisms isolated from various habitats, however, reports on PHB depolymerase isolated from plastic contaminated sites are scares. Thermophilic PHB polymerase produced by isolates obtained from plastic contaminated sites is expected to have better relevance for its application in plastic/bioplastic degradation. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase fromStenotrophomonassp. RZS 7 isolated from a plastic contaminated site. The isolate produced extracellular poly-β-hydroxybutyrate (PHB) depolymerase in the mineral salt medium at 30oC during 4 days of incubation under shake flask condition. Purification of the enzyme was carried out by three different methods using PHB as a substrate. Purification of PHB depolymerase by ammonium salt precipitation, column chromatography, and solvent purification method was successfully carried out. Among the purification method tested, the enzyme was best purified by column chromatography on Octyl-Sepharose CL-4B column with maximum (0.7993 U mg-1ml-1) purification yield. The molecular weight of purified PHB depolymerase (40 kDa) closely resembled with PHB depolymerase ofAureobacterium saperdae. Experiments on assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential ofStenotrophomonassp. RZS 7. The results obtained in FTIR analysis, HPLC study and GC-MS analysis confirmed the biodegradation attempt in liquid medium byStenotrophomonassp. RZS 7. Changes in surface morphology of PHB film in soil burial as observed in FE SEM analysis confirmed the biodegradation of PHB. The isolate was capable of degrading PHB and resulted in 87.74% degradation. Higher rate of degradation under natural soil condition is the result of activity of soil microbes that complemented the degradation byStenotrophomonassp. RZS 7.
Modelling vegetation understory cover using LiDAR metrics
Authors: Venier Lisa A. , Swystun Tom , Mazerolle Marc J. , Kreutzweiser David P. , Wainio-Keizer Kerrie L. , McIlwrick Ken A. , Woods Murray E. , Wang Xianli 
Published: July 2019

AbstractForest understory vegetation is an important feature of wildlife habitat among other things. Predicting and mapping understory is a critical need for forest management and conservation planning, but it has proved difficult. LiDAR has the potential to generate remotely sensed forest understory structure data, yet this potential has to be fully validated. Our objective was to examine the capacity of LiDAR point cloud data to predict forest understory cover. We modeled ground-based observations of understory structure in three vertical strata (0.5 m to < 1.5 m, 1.5 m to < 2.5 m, 2.5 m to < 3.5 m) as a function of a variety of LiDAR metrics using both mixed-effects and Random Forest models. We compared four understory LiDAR metrics designed to control for the spatial heterogeneity of sampling density. The four metrics were highly correlated and they all produced high values of variance explained in mixed-effects models. The top-ranked model used a voxel-based understory metric along with vertical stratum (Akaike weight = 1, explained variance = 87%, SMAPE=15.6%). We found evidence of occlusion of LiDAR pulses in the lowest stratum but no evidence that the occlusion influenced the predictability of understory structure. The Random Forest model results were consistent with those of the mixed-effects models, in that all four understory LiDAR metrics were identified as important, along with vertical stratum. The Random Forest model explained 74.4% of the variance, but had a lower cross-validation error of 12.9%. Based on these results, we conclude that the best approach to predict understory structure is using the mixed-effects model with the voxel-based understory LiDAR metric along with vertical stratum, but that other understory LiDAR metrics (fractional cover, normalized cover and leaf area density) would still be effective in mixed-effects and Random Forest modelling approaches.
What are the driving factors of pesticide overuse in vegetable production? Evidence from Chinese farmers
Authors: Yang Mansha , Zhao Xia , Meng Ting 
Published: July 2019

Purpose
Pesticide overuse has caused a series of negative impacts on environment and human health. The purpose of this paper is to examine the farmers’ behavior of pesticide overuse and to identify the underlying determinants, based on the survey data from Shandong Province, China.

Design/methodology/approach
A two-stage semiparametric approach and the binary probit model were employed in this study to analyze the marginal pesticide productivity and investigate the determinants of the pesticide overuse.

Findings
Results suggest that the marginal pesticide productivity is negative, indicating a serious overuse of pesticides in the surveyed area. Both market factors and government regulation have impacts on farmers’ use of pesticides.

Originality/value
This study estimates marginal pesticide productivity with an innovative methodology, and explores the role of market factors and government regulation in regulating farmers’ behavior of pesticide use, especially in a typical vegetable growing area and targeting a specific type of vegetable.
Return and volatility spillovers between Bitcoin and other asset classes in Turkey
Authors: Vardar Gulin , Aydogan Berna 
Published: July 2019

Purpose
With a substantial return and volatility characteristic of Bitcoin, which may be seen as a new category of investment assets, better understanding of the nature of return and volatility spillover can help investors and regulators in achieving the potential goal from portfolio diversification. The paper aims to discuss these issues.

Design/methodology/approach
This paper explores the return and volatility transmission between the Bitcoin, as the largest cryptocurrency, and other traditional asset classes, namely stock, bond and currencies from the standpoint of Turkey over the period July, 2010–June, 2018 using the newly developed multivariate econometric technique, VAR–GARCH, in mean framework with the BEKK representation.

Findings
The empirical results reveal the existence of the positive unilateral return spillovers from the bond market to Bitcoin market. Regarding the results of shock and volatility spillovers, there exists strong evidence of bidirectional cross-market shock and volatility spillover effects between Bitcoin and all other financial asset classes, except US Dollar exchange rate.

Originality/value
The important extention is the adoption of a newly developed multivariate econometric technique, VAR–GARCH, in mean framework with the BEKK representation, proposed by Engle and Kroner (1995), which is employed for the first time specifically to examine the extent of integration in terms of volatility and return between Bitcoin and key asset classes. Second, Bitcoin has experienced a rapid growth since around a decade and a number of investors are showing interest in its potential as an integrative part of portfolio diversification. The information provided by empirical results gives empirical bases from which to address topics concerning hedging purposes and optimal portfolio allocation. It is also increasingly important to analyze the current behavior of Bitcoin in relation to other assets to provide policy makers and regulatory bodies with guidance on the role of the Bitcoin as an investment asset in Turkey. Thus, this is the first serious attempt at exploring the potential for Bitcoin to offer diversification opportunities in the context of Turkey.
Does hotel cleanliness correlate with surfaces guests contact?
Authors: Park Haeik , Kline Sheryl Fried , Kim Jooho , Almanza Barbara , Ma Jing 
Published: July 2019

Purpose
This study aims to strengthen implications about hotel cleaning outcomes by comparing guests’ perception of the amount of contact they have with cleanliness of hotel surfaces.

Design/methodology/approach
This study used two data-collection methods, a survey and an adenosine triphosphate (ATP) test. Data were collected from recent hotel guests using Amazon Mechanical Turk. Guests were asked to identify hotel surfaces that they touch most frequently. Actual hotel cleanliness was measured using empirical data collected with ATP meters. The two data sets were used to compare guests’ perceptions about the amount of contact they have with actual cleanliness measurements of those hotel surfaces.

Findings
This study found that amount of guest contact was related to cleanliness of surfaces in guestrooms. Significant differences were found in guest perception between high- and low-touch areas and between guestrooms and hotel public areas. More high-touch areas and higher ATP readings were found in guestrooms than in hotel public areas.

Originality/value
To the best of the authors’ knowledge this study is the first to compare guest contact with hotel surfaces to a scientific measure of hotel cleanliness. In addition, this study is unique because it assesses guest contact and cleanliness of public areas to provide a holistic view of hotel-cleaning needs. The study offers industry empirically based results from guest perception and scientifically based data that can be used to improve hotel housekeeping programs.
Investigating green supply chain management practices and performance
Authors: Cousins Paul D. , Lawson Benn , Petersen Kenneth J. , Fugate Brian 
Published: July 2019

PurposeSustainable supply chain management has become an increasingly important driver of business performance. Understanding the contingent nature of how performance is improved in this context is therefore a critical task for management. The purpose of this paper is to explore the moderating effects of two practices unique to sustainable supply chain – ecocentricity and supply chain traceability – on a firm’s environmental and operating cost performance.Design/methodology/approachSurvey data were collected from 248 UK manufacturing firms and analyzed using moderated hierarchical regression.FindingsThe results suggest that green supply chain management (GSCM) practices are associated with improvements in both environmental and cost-based performance. Further, higher levels of ecocentricity and supply chain traceability are associated with stronger relationships between GSCM practices and cost performance. Contrary to expectations, high levels of supply chain traceability were found to negatively moderate the relationship between GSCM practices and environmental performance.Research limitations/implicationsThe research design was survey-based and cross-sectional. Future studies would benefit from longitudinal research designs that capture the effects of GSCM practices on performance over an extended period. The survey data is also perceptual; using secondary data to capture environmental performance outcomes, for example, would be another opportunity for future research.Practical implicationsThe authors provide additional support to findings that GSCM practices benefit both environmental and cost performance dimensions. In this context, the authors show that investments by firms in working with a broader set of eco-system partners (ecocentricity) and building supply chain traceability and leads to improved environmental sustainability outcomes. The authors encourage managers to carefully consider how they conceptualize and monitor their supply chains.Originality/valueThis paper offers several contributions to the research in this area. First, the authors develop and validate a measurement scale for ecocentricity and supply chain traceability. Second, the authors show how these two variables – unique to sustainable supply chains – can positively influence firm and environmental performance.
Classification and characterization of US consumers based on their perceptions of risk of tablet use in international hotels
Authors: Morosan Cristian , DeFranco Agnes 
Published: July 2019

PurposeCyber-attacks on hotel information systems could threaten the privacy of consumers and the integrity of the data they exchange upon connecting their mobile devices to hotel networks. As the perceived cyber-security risk may be reflected heterogeneously within the US consumer population traveling internationally, the purpose of this study is to examine such heterogeneity to uncover classes of US consumers based on their perceptions of risk of using tablets for various tasks when staying in hotels abroad.Design/methodology/approachUsing data collected from 1,016 US consumers who stayed in hotels abroad, this study used latent profile analysis (LPA) to classify the consumers based on their perceptions of risk associated with several tablet use behaviors in hotels.FindingsThe analysis uncovered four latent classes and produced a characterization of these classes according to several common behavioral (frequency of travel, the continent of the destination, duration of stay and purpose of travel) and demographic (gender, age, income and education) consumer characteristics.Originality/valueBeing the first study that classifies consumers based on the risk of using tablets in hotels while traveling internationally, this study brings the following contributions: offers a methodology of classifying (segmenting) consumer markets based on their cyber-security risk perceptions, uses LPA, which provides opportunities for an accurate and generalizable characterization of multivariate data that comprehensively illustrate consumer behavior and broadens the perspective offered by the current literature by focusing on consumers who travel from their US residence location to international destinations.
Ethical leadership, team leader’s cultural intelligence and ethical behavior of team members
Authors: Presbitero Alfred , Teng-Calleja Mendiola 
Published: July 2019

Purpose
Drawing from Social Learning Theory and Multiple Loci of Intelligence Theory, the purpose of this paper is to assert that, through the mechanisms of social learning and role modeling, perceived ethical leadership is positively and significantly related to ethical behavior of individual members of global teams. Moreover, this study argues that perceived cultural intelligence (CQ) of leaders which consists of perceptions of members regarding leader’s cultural knowledge and skills on how to act ethically in different cultural contexts would moderate the relationship between ethical leadership and ethical behavior of individual members of global teams.

Design/methodology/approach
To test these assertions, a survey study was conducted involving individual members of global teams in Australia (n=234).

Findings
Results demonstrate that perceived ethical leadership is positively and significantly related to an individual’s ethical behavior. Furthermore, results show that perceived leader’s CQ serves as a moderator in strengthening the relationship between perceived ethical leadership and individual member’s display of ethical behavior.

Originality/value
This study fills the gaps in the literature by examining ethical behavior of individual members of culturally diverse teams and the role that leaders play in influencing their individual display of ethical behavior. Such knowledge can provide insights particularly for human resource practitioners on how to effectively generate and ensure the display of ethical behavior in contexts that are culturally diverse like in global teams.