bluuebunny/crossref_metadata_2025 huggingface dataset:
Controllable oxidative stress and tissue specificity in major tissues during the torpor–arousal cycle in hibernating Daurian ground squirrels
Authors: Wei Yanhong , Zhang Jie , Xu Shenhui , Peng Xin , Yan Xia , Li Xiaoyu , Wang Huiping , Chang Hui , Gao Yunfang
Published: October 2018

Mammalian hibernators experience repeated hypoxic ischaemia and reperfusion during the torpor–arousal cycle. We investigated levels of oxidative stress, antioxidant capacity, and the underlying mechanism in heart, liver, brain and kidney tissue as well as plasma during different periods of hibernation in Daurian ground squirrels (
Spermophilus dauricus
). Our data showed that the levels of hydrogen peroxide significantly increased in the heart and brain during late torpor (LT) compared with levels during the summer active (SA) state. The content of malondialdehyde (MDA) was significantly lower during interbout arousal (IBA) and early torpor (ET) than that during SA or pre-hibernation (PRE), and MDA levels in the LT brain were significantly higher than the levels in other states. Superoxide dismutase 2 protein levels increased markedly in the heart throughout the entire torpor–arousal cycle. Catalase expression remained at an elevated level in the liver during the hibernation cycle. Superoxide dismutase 1 and glutathione peroxidase 1 (GPx1) expression increased considerably in all tissues during the IBA and ET states. In addition, the activities of the various antioxidant enzymes were higher in all tissues during IBA and ET than during LT; however, GPx activity in plasma decreased significantly during the hibernation season. The expression of p-Nrf2 decreased in all tissue types during IBA, but significantly increased during LT, especially in liver tissue. Interestingly, most changed indicators recovered to SA or PRE levels in post-hibernation (POST). These results suggest that increased reactive oxygen species during LT may activate the Nrf2/Keap1 antioxidant pathway and may contribute to the decreased MDA levels found during the IBA and ET states, thereby protecting organisms from oxidative damage over the torpor-arousal cycle of hibernation. This is the first report on the remarkable controllability of oxidative stress and tissue specificity in major oxidative tissues of a hibernator.
RETRACTED: Reduced miR-125a-5p level in non-small-cell lung cancer is associated with tumour progression
Authors: Liu Hongxu , Ma Yegang , Liu Changhao , Li Pengfei , Yu Tao
Published: October 2018

Emerging evidence suggests that microRNAs (miRNAs) serve an important role in tumourigenesis and development. Although the low expression of miR-125a-5p in non-small-cell lung cancer (NSCLC) has been reported, the underlying mechanism remains unknown. In the current study, the low expression of miR-125a-5p in NSCLC was verified in paired cancer tissues and adjacent non-tumour tissues. Furthermore, the CpG island in the miR-125a-5p region was hypermethylated in the tumour tissues, and the hypermethylation was negatively correlated with miR-125a-5p expression. Target gene screening showed that the histone methyltransferase Suv39H1 was one of the potential target genes.
In vitro
studies showed that miR-125a-5p could directly suppress Suv39H1 expression and decrease the H3K9me3 levels. On the other hand, Suv39H1 could induce demethylation of miR-125a-5p, resulting in re-activation of miR-125a-5p. What is more, overexpessing miR-125a-5p could also self-activate the silenced miR-125a-5p in NSCLC cells, which suppressed cell migration, invasion and proliferation
in vitro
and inhibited cancer progression
in vivo
. Thus, we found that the epigenetic silenced miR-125a-5p could be self-activated through targeting Suv39H1 in NSCLC, suggesting that miR-125a-5p might not only have the potential prognostic value as a tumour biomarker but also be a potential therapeutic target in NSCLC.
Quantum imploding scalar fields
Authors: Roberts Mark D.
Published: October 2018

The d’Alembertian □
ϕ
= 0 has the solution
ϕ
=
f
(
v
)/
r
, where
f
is a function of a null coordinate
v
, and this allows creation of a divergent singularity out of nothing. In scalar-Einstein theory a similar situation arises both for the scalar field and also for curvature invariants such as the Ricci scalar. Here what happens in canonical quantum gravity is investigated. Two minispace Hamiltonian systems are set up: extrapolation and approximation of these indicates that the quantum mechanical wave function can be finite at the origin.
Acoustic adaptation to city noise through vocal learning by a songbird
Authors: Moseley Dana Lynn , Derryberry Graham Earnest , Phillips Jennifer Nicole , Danner Julie Elizabeth , Danner Raymond Michael , Luther David Andrew , Derryberry Elizabeth Perrault
Published: October 2018

Anthropogenic noise imposes novel selection pressures, especially on species that communicate acoustically. Many animals—including insects, frogs, whales and birds—produce sounds at higher frequencies in areas with low-frequency noise pollution. Although there is support for animals changing their vocalizations in real time in response to noise (i.e. immediate flexibility), other evolutionary mechanisms for animals that learn their vocalizations remain largely unexplored. We hypothesize that cultural selection for signal structures less masked by noise is a mechanism of acoustic adaptation to anthropogenic noise. We test this hypothesis by presenting nestling white-crowned sparrows (Zonotrichia leucophyrs) with less-masked (higher-frequency) and more-masked (lower-frequency) tutor songs either during playback of anthropogenic noise (noise-tutored treatment) or at a different time from noise playback (control treatment). As predicted, we find that noise-tutored males learn less-masked songs significantly more often, whereas control males show no copying preference, providing strong experimental support for cultural selection in response to anthropogenic noise. Further, noise-tutored males reproduce songs at higher frequencies than their tutor, indicating a distinct mechanism to increase signal transmission in a noisy environment. Notably, noise-tutored males achieve lower performance songs than their tutors, suggesting potential costs in a sexual selection framework.
Whole genome sequencing enables definitive diagnosis of Cystic Fibrosis and Primary Ciliary Dyskinesia
Authors: Ellingford Jamie M , Beaman Glenda , Webb Kevin , O’Callaghan Christopher , Hirst Robert A ,   on behalf of the 100,000 Genomes Project, Black Graeme CM , Newman William G
Published: October 2018

Understanding the genomic basis of inherited respiratory disorders can assist in the clinical management of individuals with these rare disorders. We apply whole genome sequencing for the discovery of disease-causing variants in the non-coding regions of known disease genes for two individuals with inherited respiratory disorders. We describe analysis strategies to pinpoint candidate non-coding variants within the non-coding genome and demonstrate aberrant RNA splicing as a result of deep intronic variants in DNAH11 and CFTR. These findings confirm clinical diagnoses of primary ciliary dyskinesia and cystic fibrosis, respectively.
Association of the types of alcoholic beverages and blood lipids in a local population in Jharkhand, India
Authors: Verma Sunil Kumar , Rout Janmejaya , Biswas Shrutidhara , Tripathy Umakanta
Published: October 2018

Although light-to-moderate alcohol consumption is considered beneficial, alcohol in binge doses or high cumulative lifetime consumption leads to cardiovascular diseases, metabolic syndrome and structural damage to various organs. Alcohol is known to alter blood lipid concentrations; however, the association of the types of alcohol on the lipid profile has not been investigated extensively. A cross-sectional study involving male participants (n = 86) aged 20 to 60 from the Ranchi and Dhanbad zone of Jharkhand, India, was carried out to investigate the effects of cumulative lifetime consumption of Haria, a local rice-based fermented alcohol, Indian made foreign liquor (IMFL), and a combination of the two on the blood lipid profiles. Demographic characteristics, dietary intake and medical history were obtained from the participants by questionnaire, and lipid levels were determined by analysis of blood samples. The effect of Haria alone on the blood lipids was also investigated on the local female population (n = 31). After adjusting for demographic and dietary factors, IMFL and combination of IMFL and Haria consumption was associated with increased serum total cholesterol, triglyceride, and low density lipoprotein (LDL) cholesterol levels (P < 0.05) and decreased high density lipoprotein (HDL) cholesterol levels (P < 0.05). None of the blood lipids changed significantly in Haria consumers in both male and female groups. This study suggests that Haria, a popular alcoholic beverage of West Bengal and east-central India, is a relatively safe local alcoholic beverage and does not alter the lipid profile in consumers.
Non-linear changes in modelled terrestrial ecosystems subjected to perturbations
Authors: Newbold Tim , Tittensor Derek P. , Harfoot Michael B. J. , Scharlemann Jörn P. W. , Purves Drew W.
Published: October 2018

When perturbed ecosystems undergo rapid and non-linear changes, this can result in ‘regime shifts’ to an entirely different ecological state. The need to understand the extent, nature, magnitude and reversibility of these changes is urgent given the profound effects that humans are having on the natural world. It remains very challenging to empirically document non-linear changes and regime shifts within complex, real ecological communities, or even to demonstrate such shifts in simplified experimental systems. General ecosystem models, which simulate the dynamics of entire ecological communities based on a mechanistic representation of ecological processes, provide an alternative and novel way to project ecosystem changes across all scales and trophic levels and to forecast impact thresholds beyond which dramatic or irreversible changes may occur. We model non-linear changes in four terrestrial biomes subjected to human removal of plant biomass, such as occurs through agricultural land-use change. We find that irreversible and non-linear responses are predicted to be common where removal of vegetation exceeds 80% (a level that occurs across nearly 10% of the terrestrial surface), especially for organisms at higher trophic levels and in less productive ecosystems such as drylands. Very large, irreversible changes to the entire ecosystem structure are expected at levels of vegetation removal akin to those in the most intensively used real-world ecosystems. Our results suggest that the projected 21st century rapid increases in agricultural land conversion to feed an expanding human population, may lead to widespread trophic cascades and in some cases irreversible changes to the structure of ecological communities.
Demonstration of End-to-End Automation of DNA Data Storage
Authors: Takahashi Christopher N. , Nguyen Bichlien H. , Strauss Karin , Ceze Luis
Published: October 2018

We developed a complete end-to-end DNA data storage device. The device enables the encoding of data, which is then written to a DNA oligonucleotide using a custom DNA synthesizer, pooled for liquid storage, and read using a nanopore sequencer and a novel, minimal preparation protocol. We demonstrate an automated 5-byte write, store, and read cycle with the ability to expand as new technology is available.
Diminished pre-stimulus alpha-lateralization suggests compromised self-initiated attentional control of auditory processing in old age
Authors: Dahl Martin J. , Ilg Liesa , Li Shu-Chen , Passow Susanne , Werkle-Bergner Markus
Published: October 2018

Older adults experience difficulties in daily situations that require flexible information selection in the presence of multiple competing sensory inputs, like for instance multi-talker situations. Modulations of rhythmic neural activity in the alpha–beta (8–30 Hz) frequency range in posterior brain areas have been established as a cross-modal neural correlate of selective attention. However, research linking compromised auditory selective attention to changes in rhythmic neural activity in aging is sparse.

We tested younger (n = 25; 22–35 years) and older adults (n = 26; 63–76 years) in an attention modulated dichotic listening task. In this, two streams of highly similar auditory input were simultaneously presented to participants′ both ears (i.e., dichotically) while attention had to be focused on the input to only one ear (i.e. target) and the other, distracting information had to be ignored.

We here demonstrate a link between severely compromised auditory selective attention in aging and a partial reorganization of attention-related rhythmic neural responses. In particular, in old age we observed a shift from a self-initiated, preparatory modulation of alpha rhythmic activity to an externally driven, response in the alpha–beta range. Critically, moment-to-moment fluctuations in the age-specific patterns of self-initiated and externally driven lateralized rhythmic activity were tied to selective attention. We conclude that adult age difference in spatial selective attention likely derive from a functional reorganization of rhythmic neural activity within the aging brain.
A cellular anatomy of the normal adult human prostate and prostatic urethra
Authors: Henry Gervaise H. , Malewska Alicia , Joseph Diya B. , Malladi Venkat S. , Lee Jeon , Torrealba Jose , Mauck Ryan J. , Gahan Jeffrey C. , Raj Ganesh V. , Roehrborn Claus G. , Hon Gary C. , MacConmara Malcolm P. , Reese Jeffrey C. , Hutchinson Ryan C. , Vezina Chad M. , Strand Douglas W.
Published: October 2018

A cellular anatomy of normal human organs is essential for solving the cellular origins of disease. We report the first comprehensive cellular atlas of the young adult human prostate and prostatic urethra using an iterative process of single cell RNA sequencing and flow cytometry on ~98,000 cells taken from different anatomical regions. Two previously unrecognized epithelial cell types were identified by KRT13 and SCGB1A1 expression and found to be highly similar to hillock and club cells of the proximal lung. It was demonstrated by immunohistochemistry that prostate club and hillock cells are similarly concentrated in the proximal prostate. We also optimized a new flow cytometry antibody panel to improve cell type-specific purification based on newly established cellular markers. The molecular classification, anatomical distribution, and purification methods for each cell type in the human prostate create a powerful new resource for experimental design in human prostate disease.
The work engagement–performance link: an episodic perspective
Authors: Reina-Tamayo Andrea Marcela , Bakker Arnold B. , Derks Daantje
Published: October 2018

Purpose

The purpose of this paper is to integrate job demands–resources theory and the episodic process model to examine the relationships between episodic cognitive mechanisms (i.e. cognitive interference and attentional pull), work engagement and performance. It is hypothesized that an episode characterized by less cognitive interference and more attentional pull (i.e. attraction toward the work activity) is associated with the highest levels of work engagement and job performance. Additionally, it is hypothesized that episodic challenge/hindrance job demands boost/diminish the positive relationship between episodic job resources and work engagement.

Design/methodology/approach

Using experience sampling methodology, 48 employees used their smartphones to complete surveys three times a day for one week, resulting in 266 observations.

Findings

Results of multilevel analyses suggest that episodic hindrance job demands (but not challenge job demands) moderate the positive relation between job resources and work engagement.

Originality/value

This study is unique in that it captures fluctuating cognitive processes (i.e. attentional pull and cognitive interference) that take place during work activities.
Challenges in the EM-based design of modern telecommunication satellite antennas
Authors: Reiche Enrico , Schneider Michael
Published: October 2018

Purpose

This paper aims to introduce design challenges of modern telecommunication satellite antennas. The antenna farms accommodated on a satellite are systems of high complexity. From the radio frequency (RF) point of view, the most important design issues, e.g. high power applications in space (vacuum) or typical antenna scenarios (single/multi beam antennas), and their solution are considered.

Design/methodology/approach

The paper presents the application of electro-magnetic (EM) field simulation in the design and optimisation process. The design of a telecommunications satellite antenna splits into several areas, for which different types of EM field solvers are used.

Findings

The use of EM field solvers enables an accurate and efficient design approach of modern geostationary telecommunications satellite antennas. Due to the use of EM field solvers, an excellent agreement between predictions and measurement results on feed as well as antenna system level is achieved.

Originality/value

This paper gives an overview of state-of-the-art telecommunications satellite antenna architectures and their efficient RF design due to the use of EM field solvers. Typical high power effects and other design issues are explained. RF engineers are encouraged to work on this exciting topic to further improve the design process and to develop new satellite antenna and feed products.
Dynamic interaction between higher education and economic progress: a comparative analysis of BRICS countries
Authors: Chang Victor , Chen Yian , Xiong Chang
Published: October 2018

Purpose

The purpose of this paper is to gain a deeper insight on how education boosts economic progress in key emerging economies. This project is aimed at exploring the interactive dynamics between the tertiary education sector and economic development in BRICS countries. The author also aims to examine how the structure of higher education contributes to economic expansion.

Design/methodology/approach

The author uses the time series data of BRICS countries across approximately two decades to determine the statistical causality between the size of tertiary enrollment and economic development. The linear regression model is then used to figure out the different impact levels of academic and vocational training programs at the tertiary level to economic development.

Findings

Data from all BRICS countries exhibited a unidirectional statistical causality relationship, except the Brazilian data. The national economic expansion Granger Caused increased tertiary enrollment in Russia and India, while in China and South Africa, higher education enrollment Granger Caused economic progress. The impact from tertiary academic training is found to be positive for all BRICS nations, while tertiary vocation training is shown to have impaired the Russian and South African economy.

Research limitations/implications

This project is based on a rather small sample size, and the stationary feature of the time series could be different should a larger pool of data spanning a longer period of time is used. In addition, the author also neglects other control variables in the regression model. Therefore, the impact level could be distorted due to possible omitted variable bias.

Practical implications

Tertiary academic study is found to have a larger impact level to all countries’ economic advancement, except for China, during the time frame studied. There is a statistical correlation between the education and economic progress. This is particularly true for BRICS countries, especially China. But the exception is Brazil.

Social implications

The government should provide education up to the certain level, as there is a direct correlation to the job creation and economic progress. Furthermore, the government should also work closely with industry to ensure growth of industry and creation of new jobs.

Originality/value

The comparative analysis and evaluation of the dynamic interaction of tertiary enrollment and economic output across all five BRICS nations is unique, and it deepens the understanding of the socioeconomic development in these countries from a holistic management perspective.
Energy advice in Germany: a market actors’ perspective
Authors: Ringel Marc
Published: October 2018

Purpose

This study reviews present trends, barriers and outlooks for the future as seen by actors in the energy advice services market in Germany. As Germany is one of Europe’s leading markets for energy services, this review aims to highlight energy sector management issues that exist throughout Europe.

Design/methodology/approach

This study combines qualitative and quantitative research approaches, using seven qualitative stakeholder interviews and a semi-structured survey covering over 500 energy advisors. Based on the present market, this study seeks to identify barriers against further market development, regulatory measures that can promote market development and business models for energy services likely to emerge in the future.

Findings

Significant barriers persist, despite a strong government commitment to support development of the energy services markets. The barriers encourage market actors to maintain the status quo rather than use innovate new service models. To support innovative business models, action is needed by both industry associations and the government to create a stronger demand pull for advice services.

Originality/value

This paper provides a new sectoral overview of Europe’s biggest energy service market as seen from a market actor perspective. It focuses on the analysis of barriers and business models to derive needs for further capacity building within the sector and for political governance to trigger further market dynamics.
A comparative study on industrial spillover effects among Korea, China, the USA, Germany and Japan
Authors: Min Yong-Ki , Lee Sang-Gun , Aoshima Yaichi
Published: October 2018

Purpose

Starting from industry 4.0 in Germany and followed by the New Strategy for American Innovation in the USA and the smartization strategy in Japan, developed countries are pushing nation-wide innovation strategies. Similarly, China is pursuing the Made in China 2025, and Korea announced the Manufacturing Industry Innovation 3.0 strategy. However, few researchers have identified the industrial structure that establishes the foundation of the 4th Industrial Revolution or have derived strengths and weaknesses to provide implications on policy formulation through quantitative comparison with developed countries. Therefore, the purpose of this paper is to analyze the spillover effect of the information and communication technology (ICT) industry (the foundation of the 4th Industrial Revolution) and machinery·equipment industry (the foundation of smart manufacturing through convergence with ICT industry).

Design/methodology/approach

This study examines the industrial spillover effects of the ICT industry and machinery·equipment industry in the USA, Germany, Japan, China and Korea by using the World Input–Output Table from 2000 to 2014.

Findings

The results showed that backward linkage effect of the ICT Industry are high in the order of Korea≑China>Japan>the USA≑Germany, and forward linkage effect of the ICT industry are high in the order of Japan ≑> the USA≑Korea ≑> China ≑> Germany. Backward linkage effects of the machinery·equipment industry are high in the order of China>Japan≑Korea>the USA>Germany, and forward linkage effects of the machinery·equipment industry are high in the order of China>Korea>Germany≑Japan≑the USA.

Practical implications

China and Korea encourage active government investment in ICT and machinery·equipment industries, especially the intentional convergence between ICT and machinery·equipment industries is expected be generate higher synergy. The “innovation in manufacturing” strategy in the USA that utilizes its strength in ICT services seems appropriate, whereas Germany needs to revitalize the ICT industry to strengthen its manufacturing industry. Japan’s strategy is to focus its ICT capabilities on robot sector. While the scope of innovation is limited, its synergy is worth expecting.

Originality/value

This study attempted to provide a theoretical approach to the determination of national policy strategies and provide practical implications for response to the impacts of the 4th Industrial Revolution, by comparing the inducement effects of ICT and machinery·equipment industries between major countries.
Digital visual engagement: influencing purchase intentions on Instagram
Authors: Valentini Chiara , Romenti Stefania , Murtarelli Grazia , Pizzetti Marta
Published: October 2018

Purpose

The purpose of this paper is to investigate the effects of visual communications on Instagram users’ propensity to engage with image-based content through online behaviors such as liking, sharing, commenting and following, and their intention to purchase the product depicted in the visual communications.

Design/methodology/approach

An experimental design was used to measure the effect of branded Instagram images on a sample of active Instagram users. Two features of Instagram images (subject’s gaze: direct vs indirect; product salience: low vs high) were manipulated and their interactive effect tested on online behaviors.

Findings

The paper offers empirical evidence that direct gaze and high product salience positively affect digital visual engagement. Moreover, digital visual engagement influences intention to purchase.

Research limitations/implications

The hypotheses were tested on a single product category and on only two image-based features. Further studies might replicate the experiment on different product categories and include different image-based features.

Practical implications

This empirical study can offer communication managers important information on the image-based features that are most effective in increasing digital visual engagement and positively influencing purchase intentions in visual communications.

Originality/value

The study empirically demonstrates that the choice of specific image-based features in visual communication matters for increasing digital visual engagement among Instagram users.
m-servicescape: effects of the hotel mobile app servicescape preferences on customer response
Authors: Lee Seonjeong Ally
Published: October 2018

Purpose

This paper aims to explore how customer engagement behaviors and brand loyalty are enhanced through customers’ preferences of m-servicescape, based on the S-O-R model as a theoretical background.

Design/methodology/approach

A cross-sectional, online, self-administered survey method was conducted to examine proposed relationships by recruiting previous users of hotel mobile apps in the USA.

Findings

Results identified aesthetics, functionality and symbolism preferences of the m-servicescape fulfilled customers’ evaluations on autonomy and relatedness needs fulfillment, which positively influenced their engagement behaviors and brand loyalty.

Research/limitations/implications

This study contributed to mobile marketing research by investigating customers’ preferences of m-servicescapes that enhanced customers’ positive responses in the hotel industry.

Practical implications

Practical implications are as follows: using a holistic approach to explore mobile service environments in fulfilling customers’ needs, enhanced customers’ engagement behaviors and brand loyalty.

Originality/value

This study proposed and empirically investigated the role of m-servicescapes in customers’ evaluations on needs fulfillment and their positive responses in the hotel industry.
Mediating and moderating impact of goal orientation and emotional intelligence on the relationship of knowledge oriented leadership and knowledge sharing
Authors: Shariq Syed Muhammad , Mukhtar Umer , Anwar Suleman
Published: October 2018

Purpose

This paper aims to examine the underlying mechanism through which knowledge-oriented leadership (KOL) encourages knowledge sharing (KS) among the employees. It investigates KOL as an antecedent of KS. Furthermore, it also examines the mediation of employee goal orientation in the relationship of KOL and KS. Moderating role of emotional intelligence is also examined.

Design/methodology/approach

Multilayer data were collected from 223 employees of pharmaceutical industry in Pakistan. Structural equation modelling (SEM) is applied to analyse the model and hypothesis.

Findings

The result supports the direct positive effect of KOL on KS. Indirect effect of KOL on KS through the mediation of employee learning goal orientation is also supported by the result.

Practical implications

Organizations or managers should engage their learning-oriented employees newly hired employee and front line manager in KS process. Leader should give different task to such an employee who did not perform earlier because in doing so, such employee will explore or exploit their own tacit knowledge and that of their colleagues.

Originality/value

This study contributes to the existing body of knowledge by establishing unexplored indirect effect of KOL on KS through the mediation of employee goal orientation. By discussing goal orientation as an outcome of KOL, this study extends the literature of the outcomes of KOL, which are currently limited to KM, work attitudes and innovative performance.
Back to the future with IATA NDC? Critical turning points in the history of airline distribution
Authors: Bingemer Stephan
Published: October 2018

Purpose

The International Air Transport Association (IATA) New Distribution Capability (NDC) standard aims at modernising the airline distribution landscape. It has supported the spread of Direct Connects by providing a common standard for linking airlines to travel agencies. The purpose of this paper is to analyse the historical development of airline distribution and to derive implications for the future.

Design/methodology/approach

This paper follows the approach of Yeoman and McMahon-Beattie (2017) in providing a chronological account based on published research.

Findings

Direct Connects are discussed to be a step back in the evolution of the distribution landscape because they foster disaggregation. An analysis of the history of distribution finds that a comparison of Direct Connects to the early stages of computer reservation system technology falls short to recognise the tremendous technological and market changes connected to the internet, cloud computing and the rise of low-cost carriers. Moreover, drawing on the seminal article by Anderson and Tushman (1990) on technical discontinuities and dominant designs, the current state of the distribution landscape is characterised to be an era of ferment that is driven by design competition and that might end up in a new dominant design.

Originality/value

The originality of this paper lies in a critical review of the turning points of distribution. By reviewing the past developments, the paper sheds light on the contribution that IATA NDC and Direct Connect technology might deliver to the field of airline distribution.
Elements that influence knowledge sharing in the university-industry-government collaboration
Authors: Castro Igor Junqueira de , Nagano Marcelo Seido , Ribeiro Suzana Xavier
Published: October 2018

Purpose

The purpose of this paper is to determine the factors for an academic research project in electrical engineering to become relevant.

Design/methodology/approach

As a conceptual basis, a few theories of entrepreneurial university and triple helix were correlated, seeking to determine the main critical factors and the successful criteria of an academic research project. The research was conducted through four cases of electric engineering that succeed in generating social and economic impact.

Findings

When analyzing the available bibliography, it is clear that the connection among the companies, the market and the research that happens at the university is very important. Not only that, but also, according to the results, this is the key to generating revenue and impact on society. In addition, operational policies and competent leaders promoting this impact inside the universities are extremely important.

Originality/value

The topic was selected because of the reduced number of articles related to the identification and analyses of the main aspects that make an academic research project relevant to the society. Furthermore, the paper is significant because it analyzes the main factors that help develop a better society and country through academic research.
Automated post machining process planning for a new hybrid manufacturing method of additive manufacturing and rapid machining
Authors: Chen Niechen , Barnawal Prashant , Frank Matthew Charles
Published: October 2018

Purpose

The purpose of this paper is to present a new method for automated post machining process planning for a hybrid manufacturing process. The manufacturing process is expected to generate complex functional parts by taking advantage of free form surface creation from additive manufacturing and high-quality surface finishing from CNC milling.

Design/methodology/approach

The hybrid process starts with additive manufacturing to generate a near net shape part with pre-defined machining allowances on surfaces requiring high quality surface or tight tolerances, along with integrated fixture geometry. The next step is to conduct automated machining process planning to determine critical parameters such as setup angle, tool selection, depth, tool containment, and consequently, the NC code to machine the part.

Findings

This method is shown to be a feasible solution for rapidly creating functional parts. The tests have been conducted to validate the method developed in this paper.

Originality/value

This paper introduces a new automated post machining process planning method for integrating additive manufacturing with a rapid milling process.
Generating support structures for additive manufacturing with continuum topology optimization methods
Authors: Liu Yang , Li Zuyu , Wei Peng , Chen Shikui
Published: October 2018

Purpose

The purpose of this paper is to explore the possibility of combining additive manufacturing (AM) with topology optimization to generate support structures for addressing the challenging overhang problem. The overhang problem is considered as a constraint, and a novel algorithm based on continuum topology optimization is proposed.

Design/methodology/approach

A mathematical model is formulated, and the overhang constraint is embedded implicitly through a Heaviside function projection. The algorithm is based on the Solid Isotropic Material Penalization (SIMP) method, and the optimization problem is solved through sensitivity analysis.

Findings

The overhang problem of the support structures is fixed. The optimal topology of the support structures is developed from a mechanical perspective and remains stable as the material volume of support structures changes, which allows engineers to adjust the material volume to save cost and printing time and meanwhile ensure sufficient stiffness of the support structures. Three types of load conditions for practical application are considered. By discussing the uniform distributive load condition, a compromise result is achieved. By discussing the point load condition, the removal work of support structures after printing is alleviated. By discussing the most unfavorable load condition, the worst collapse situation of the printing model during printing process is sufficiently considered. Numerical examples show feasibility and effectiveness of the algorithm.

Research limitations/implications

The proposed algorithm involves time-consuming finite element analysis and iterative solution, which increase the computation burden. Only the overhang constraint and the minimum compliance problem are discussed, while other constraints and objective functions may be of interest.

Practical implications

Compared with most of the existing heuristic or geometry-based support-generating algorithms, the proposed algorithm develops support structures for AM from a mechanical perspective, which is necessary for support structures particularly used in AM for mega-scale construction such as architectures and sculptures to ensure printing success and accuracy of the printed model.

Social implications

With the rapid development of AM, complicated structures result from topology optimization are available for fabrication. The present paper demonstrates a combination of AM and topology optimization, which is the trend of fabricating manner in the future.

Originality/value

This paper remarks the first of attempts to use continuum topology optimization method to generate support structures for AM. The methodology used in this work is theoretically meaningful and conclusions drawn in this paper can be of important instruction value and practical significance.
Post-processing of FDM parts to improve surface and thermal properties
Authors: Nguyen Trieu Khoa , Lee Bong-Kee
Published: October 2018

Purpose

The purpose of this paper is to develop a novel post-processing technique of fused deposition modeling (FDM) parts to improve surface roughness and reduce heat absorption and for high-temperature application in thermoforming process.

Design/methodology/approach

The current technique consists of chemical treatment, drying and aluminum coating. First, surface morphology was investigated using FDM specimens with a flat surface. The heat absorption characteristic was also analyzed by Taguchi-based design of experiment and modified lump-capacity model. In addition, dimensional accuracy and uniformity were investigated under high-temperature conditions, which were similar to a typical thermoforming process, with specimens having concave and convex grooves.

Findings

It was verified that the proposed post-processing technique could efficiently improve surface quality of FDM parts with the arithmetic average surface roughness of 2.06 µm. In addition, the coated aluminum layer was found to reflect the heat radiation, resulting into a sufficient reduction of heat absorption. From the investigation of dimensional accuracy and uniformity, it was found that the current technique produced maximum change of 0.11 mm and uniform thickness of an aluminum layer within 0.07 mm.

Originality/value

The present study establishes a novel post-processing technique, enabling to treat the surface of FDM parts for high-temperature applications. It provides a simple way of using typical FDM parts for a thermoforming process as the mold cores. Furthermore, it can be used in other rapid tooling technologies, consequently widening the application areas of FDM.
Intraspecific variation in lizard heat tolerance alters estimates of climate impact
Authors: Herrando‐Pérez Salvador , Ferri‐Yáñez Francisco , Monasterio Camila , Beukema Wouter , Gomes Verónica , Belliure Josabel , Chown Steven L. , Vieites David R. , Araújo Miguel B.
Published: October 2018

Research addressing the effects of global warming on the distribution and persistence of species generally assumes that population variation in thermal tolerance is spatially constant or overridden by interspecific variation. Typically, this rationale is implicit in sourcing one critical thermal maximum (CTmax) population estimate per species to model spatiotemporal cross‐taxa variation in heat tolerance. Theory suggests that such an approach could result in biased or imprecise estimates and forecasts of impact from climate warming, but limited empirical evidence in support of those expectations exists.

We experimentally quantify the magnitude of intraspecific variation in CTmax among lizard populations, and the extent to which incorporating such variability can alter estimates of climate impact through a biophysical model. To do so, we measured CTmax from 59 populations of 15 Iberian lizard species (304 individuals).

The overall median CTmax across all individuals from all species was 42.8°C and ranged from 40.5 to 48.3°C, with species medians decreasing through xeric, climate‐generalist and mesic taxa. We found strong statistical support for intraspecific differentiation in CTmax by up to a median of 3°C among populations. We show that annual restricted activity (operative temperature > CTmax) over the Iberian distribution of our study species differs by a median of >80 hr per 25‐km2 grid cell based on different population‐level CTmax estimates. This discrepancy leads to predictions of spatial variation in annual restricted activity to change by more than 20 days for six of the study species.

Considering that during restriction periods, reptiles should be unable to feed and reproduce, current projections of climate‐change impacts on the fitness of ectotherm fauna could be under‐ or over‐estimated depending on which population is chosen to represent the physiological spectra of the species in question. Mapping heat tolerance over the full geographical ranges of single species is thus critical to address cross‐taxa patterns and drivers of heat tolerance in a biologically comprehensive way.
The crab spider–pitcher plant relationship is a nutritional mutualism that is dependent on prey‐resource quality
Authors: Lam Weng Ngai , Tan Hugh T. W.
Published: October 2018

Nutritional mutualisms are one of the three major categories of mutualisms and involve the provision of limiting nutrients (resources) to one species by another. It was recently shown in laboratory experiments that two species of pitcher‐dwelling crab spiders (Thomisidae),Thomisus nepenthiphilusandMisumenops nepenthicola, increased capture rates of flesh flies (Sarcophagidae) for their host,Nepenthes gracilis. The spiders ambushed pitcher‐visiting flesh flies and dropped their carcasses into pitchers after consuming them. The consumption of shared prey‐resources by crab spiders and pitcher plants presents the possibility of parasitism between them. However, ecologically generalizable mechanisms that predict the context‐dependent outcomes of such mutualisms are not known.

The effectiveness framework (mutualism effectiveness = quality × quantity) is useful for examining the total effect of mutualisms, but its quality component can be difficult to define. We identify the crab spider–pitcher plant interaction as a type of resource conversion mutualism and propose that the quality component in such interactions is the amount of the underlying resource contained in each unit of resource processed. We then used the crab spider–pitcher plant interaction to test the hypothesis that resource conversion mutualisms are more beneficial to the nutrient recipient when operating through high‐quality resources (i.e., large prey, in this interaction).

We sampled the prey and inquilines of 107N. gracilisupper pitches in situ and analysed the differences between pitchers that were inhabited or uninhabited by crab spiders, and the differences between nutritional contents of prey that were consumed by crab spiders or not.

Pitchers inhabited byT. nepenthiphiluscontained higher numbers of several prey taxa, many of which were flying insects. Consumption byT. nepenthiphilusreduced the nutrient contents in all prey examined. Overall,T. nepenthiphilus‐assisted prey capture is likely to result in a net nutrient gain forN. gracilisthat is proportional to the size of prey consumed byT. nepenthiphilus.

Our results suggest that resource conversion mutualisms are more likely to operate through high‐quality resources, since the nutrient‐processing species necessarily reduces the quality of the resource it processes while increasing its availability to the nutrient recipient species.
Prey‐specific impact of cold pre‐exposure on kill rate and reproduction
Authors: Jensen Kim , Toft Søren , Sigsgaard Lene , Sørensen Jesper G. , Holmstrup Martin
Published: October 2018

Temperature influences biological processes of ectotherms including ecological interactions, but interaction strengths may depend on species‐specific traits. Furthermore, ectotherms acclimate to prevailing thermal conditions by adjusting physiological parameters, which often implies costs to other fitness‐related parameters. Both predators and prey may therefore pay thermal acclimation costs following exposure to suboptimal temperatures. However, these costs may be asymmetrical between predator and prey, and between the predator and different species of concurrent prey.

We investigated whether thermal pre‐exposure affected subsequent kill rate and predator fitness when foraging on prey that differ in ease of capture, and whether changes were primarily caused by predator or by prey pre‐exposure effects. Specifically, we were interested in whether there were interactions between predator pre‐exposed temperature and specific prey.

Using the mesostigmatid mite Gaeolaelaps aculeifer as a generalist predator and the collembolans Folsomia candida and Protaphorura fimata as prey, we measured the impact of present temperature, predator pre‐exposure temperature, prey pre‐exposure temperature (all 10 or 20°C), prey species, and all interactions on prey numbers killed, predator eggs produced, and exploitation of killed prey in a full factorial design.

Mites killed P. fimata in equal numbers independent of the presence of F. candida, but killed F. candida when P. fimata was absent. Mite kill rate and reproduction were significantly affected by mite pre‐exposure temperature and test temperature, but not by prey pre‐exposure temperature. Significantly more of the slower prey was killed than of the quicker prey. Importantly, we found significant synergistic negative interaction effects between predator cold pre‐exposure and hunting prey of higher agility on predator kill rate and reproduction.

Our findings show that the negative effects of cold and cold pre‐exposure on kill rate and reproduction may be more severe when predators forage on quick prey. The study implies that predator cold exposure has consequences for specific prey survival following cold due to altered predation pressures, which in nature should influence the specific prey population dynamics and apparent competition outcomes. The findings exemplify how not only current but also preceding conditions affect ecological interactions, and that effect strength depends on the species involved.