bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Mass Spectrometry Imaging Reveals Mutation Status-independent Lack of Imatinib Penetration into Liver Metastases of Gastrointestinal Stromal Tumors
Authors: Sammour Denis Abu , Marsching Christian , Geisel Alexander , Erich Katrin , Schulz Sandra , Guevara Carina Ramallo , Rabe Jan-Hinrich , Marx Alexander , Findeisen Peter , Hohenberger Peter , Hopf Carsten
Published: February 2019

Mass spectrometry imaging (MSI) is an enabling technology for label-free drug disposition studies at high spatial resolution in life science- and pharmaceutical research. We present the first extensive clinical matrix-assisted laser desorption/ionization (MALDI) quantitative mass spectrometry imaging (qMSI) study of drug uptake and distribution in clinical specimen, analyzing 56 specimens of tumor and corresponding non-tumor tissues from 28 imatinib-treated patients with biopsy-proven gastrointestinal stromal tumors (GIST). For validation, we compared MALDI-TOF-qMSI with conventional UPLC-ESI-QTOF-MS-based quantification from tissue extracts and with ultra-high resolution MALDI-FTICR-qMSI. We introduced a novel generalized nonlinear calibration model of drug quantities based on focused computational evaluation of drug-containing areas that enabled better data fitting and assessment of the inherent method nonlinearities. Imatinib tissue spatial maps revealed striking inefficiency in drug penetration into GIST liver metastases even though the corresponding healthy liver tissues in the vicinity showed abundant imatinib levels beyond the limit of quantification (LOQ), thus providing evidence for secondary drug resistance independent of mutation status. Taken together, these findings underline the important application of MALDI-qMSI for studying the spatial distribution of molecularly targeted therapeutics in oncology.
Perceptual saccadic suppression starts in the retina
Authors: Idrees Saad , Baumann Matthias P. , Franke Felix , Münch Thomas A. , Hafed Ziad M.
Published: February 2019

Visual sensitivity, probed through perceptual detectability of very brief visual stimuli, is strongly impaired around the time of rapid eye movements. This robust perceptual phenomenon, called saccadic suppression, is frequently attributed to active suppressive signals that are directly derived from eye movement commands. Here we show instead that visual-only mechanisms, activated by saccade-induced image shifts, can account for all perceptual properties of saccadic suppression that we have investigated. Such mechanisms start at, but are not necessarily exclusive to, the very first stage of visual processing in the brain, the retina. Critically, neural suppression originating in the retina outlasts perceptual suppression around the time of saccades, suggesting that extra-retinal movement-related signals, rather than causing suppression, may instead act to shorten it. Our results demonstrate a far-reaching contribution of visual processing mechanisms to perceptual saccadic suppression, starting in the retina, without the need to invoke explicit motor-based suppression commands.
SNAP23 is required for the maintenance of meiotic arrest and cortical granule exocytosis in mouse oocytes
Authors: Mehlmann Lisa M. , Uliasz Tracy F. , Lowther Katie M.
Published: February 2019

Mammalian oocytes are stored in the ovary for prolonged periods, arrested in meiotic prophase. During this period, their plasma membranes are constantly being recycled by endocytosis and exocytosis. However, the function of this membrane turnover is unknown. Here, we investigated the requirement for exocytosis in the maintenance of meiotic arrest. Using a newly developed method for rapidly and specifically depleting proteins in oocytes, we have identified the SNARE protein, SNAP23, to be required for meiotic arrest. Degradation of SNAP23 causes premature meiotic resumption in follicle-enclosed oocytes. The reduction in SNAP23 is associated with loss of gap junction communication between the oocyte and surrounding follicle cells. Reduction of SNAP23 protein also inhibits cortical granule exocytosis in response to a Ca2+ stimulus, as measured by lectin staining and cleavage of ZP2. Our results show an essential role for SNAP23 in two key processes that occur in mouse oocytes and eggs.

The SNARE protein, SNAP23, is required to maintain gap junction communication between the oocyte and follicle cells that is needed to maintain oocyte meiotic arrest, as well as for cortical granule exocytosis at fertilization.
Self-reported Health is Related to Body Height and Waist Circumference in Rural Indigenous and Urbanised Latin-American Populations
Authors: Leongoméz Juan David , Sánchez Oscar R. , Vásquez-Amézquita Milena , Valderrama Eugenio , Castellanos-Chacón Andrés , Morales-Sánchez Lina , Nieto Javier , González-Santoyo Isaac
Published: February 2019

Body height is a life-history component. It involves important costs for its expression and maintenance, which may originate trade-offs on other costly components such as reproduction or immunity. Although previous evidence has supported the idea that human height could be a sexually selected trait, the explanatory mechanisms that underlie this selection are poorly understood. Despite extensive studies on the association between height and attractiveness, the role of immunity in linking this relation is scarcely studied, particularly in non-Western populations. Here, we tested whether human height is related to health measured by self-perception, and relevant nutritional and health anthropometric indicators in three Latin-American populations that widely differ in socioeconomic and ecological conditions: two urbanised populations from Bogota (Colombia) and Mexico City (Mexico), and one isolated indigenous population (Me’Phaa, Mexico). Results showed that self-reported health is best predicted by an interaction between height and waist circumference, and the costs associated with large waist circumference are height-dependent, affecting taller people more than shorter individuals. If health and genetic quality cues play an important role in human mate-choice, and height and waist interact to signal health, its evolutionary consequences, including cognitive and behavioural effects, should be addressed in future research.
Transposon-insertion sequencing screens unveil requirements for EHEC growth and intestinal colonization
Authors: Warr Alyson R. , Hubbard Troy P. , Munera Diana , Blondel Carlos J. , Abel zur Wiesch Pia , Abel Sören , Wang Xiaoxue , Davis Brigid M , Waldor Matthew K.
Published: February 2019

EnterohemorrhagicEscherichia coliO157:H7 (EHEC) is an important food-borne pathogen that colonizes the colon. Transposon-insertion sequencing (TIS) was used to identify genes required for EHEC and commensalE. coliK-12 growth in vitro and for EHEC growth in vivo in the infant rabbit colon. Surprisingly, many conserved loci contribute to EHEC’s but not to K-12’s growth in vitro, suggesting that gene acquisition during EHEC evolution has heightened the pathogen’s reliance on certain metabolic processes that are dispensable for K-12. There was a restrictive bottleneck for EHEC colonization of the rabbit colon, which complicated identification of EHEC genes facilitating growth in vivo. Both a refined version of an existing analytic framework as well as PCA-based analysis were used to compensate for the effects of the infection bottleneck. These analyses confirmed that the EHEC LEE-encoded type III secretion apparatus is required for growth in vivo and revealed that only a few effectors are critical for in vivo fitness. Numerous mutants not previously associated with EHEC survival/growth in vivo also appeared attenuated in vivo, and a subset of these putative in vivo fitness factors were validated. Some were found to contribute to efficient type-three secretion while others, includingtatABC, oxyR, envC, acrAB, andcvpA, promote EHEC resistance to host-derived stresses encountered in vivo.cvpA, which is also required for intestinal growth of several other enteric pathogens, proved to be required for EHEC,Vibrio choleraeandVibrio parahaemolyticusresistance to the bile salt deoxycholate. Collectively, our findings provide a comprehensive framework for understanding EHEC growth in the intestine.

Author Summary

EnterohemorrhagicE. coli(EHEC) are important food-borne pathogens that infect the colon. We created a highly saturated EHEC transposon library and used transposon insertion sequencing to identify the genes required for EHEC growth in vitro and in vivo in the infant rabbit colon. We found that there is a large infection bottleneck in the rabbit model of intestinal colonization, and refined two analytic approaches to facilitate rigorous identification of new EHEC genes that promote fitness in vivo. Besides the known type III secretion system, more than 200 additional genes were found to contribute to EHEC survival and/or growth within the intestine. The requirement for some of these new in vivo fitness factors was confirmed, and their contributions to infection were investigated. This set of genes should be of considerable value for future studies elucidating the processes that enable the pathogen to proliferate in vivo and for design of new therapeutics.
Optical properties of living corals determined with diffuse reflectance spectroscopy
Authors: Jacques Steven L. , Wangpraseurt Daniel , Kühl Michael
Published: February 2019

The internal light field and thus light exposure of the photosymbiotic microalgae (Symbiodinium sp.) in corals is strongly modulated by the optical properties of coral tissue and skeleton. While there are numerous studies documenting the light microenvironment in corals, there are only few measurements of the inherent optical properties of corals in the literature, and this has hampered a more quantitative understanding of coral optics. Here we present a study of the optical properties of 26 live coral samples, representative of 11 coral species and spanning a variety of morphotypes. We employed well-established fiber-optic reflectance spectroscopy techniques from biomedical optics using two methods: (1) A source and a detection fiber separated by a variable distance measured the lateral spread of light in corals, dominated by the skeleton; (2) A fiber-optic field radiance probe measured the diffuse reflectance from the coral surface, dominated by the living coral tissue. Analysis based on diffusion theory and Monte Carlo simulation yielded estimates of the bulk scattering and absorption coefficients of the coral tissue and skeleton, in the 750-1030 nm wavelength range. Extrapolating into the spectral region of photosynthetically active radiation (PAR, 400-700 nm) allowed estimation of the optical depth of absorption by the main Symbiodinium photopigment chlorophyll a. Coral tissue scattering was on average ~1.9x stronger than the scattering of the skeleton, consistent with the model that corals trap photons by high scattering to enhance absorption by algal pigments, while the lower scattering of the skeleton allows spread of light to otherwise shaded coral tissue areas.
EASY TWO-PHOTON IMAGE-SCANNING MICROSCOPY WITH SPAD ARRAY AND BLIND IMAGE RECONSTRUCTION
Authors: Koho S. V. , Slenders E. , Tortarolo G. , Castello M. , Buttafava M. , Villa F. , Tcarenkova E. , Ameloot M. , Bianchini P. , Sheppard C.J.R. , Diaspro A. , Tosi A. , Vicidomini G.
Published: February 2019

Two-photon excitation (2PE) microscopy is the imaging modality of choice, when one desires to work with thick biological samples, possibly in-vivo. However, the resolution in two-photon microscopy is poor, below confocal microscopy, and the lack of an optical pinhole becomes apparent in complex samples as reduced quality of optical sectioning. Here, we propose a straightforward implementation of 2PE image scanning microscopy (2PE-ISM) that, by leveraging our recently introduced ISM platform – based on a new single-photon avalanche diode array detector – coupled with a novel blind image reconstruction method, is shown to improve the optical resolution, as well as the overall image quality in various test samples. Most importantly, our 2PE-ISM implementation requires no calibration or other input from the user – it works like any old and familiar two-photon system, but simply produces higher resolution images (in real-time). Making the complexity disappear, in our view, is the biggest novelty here, and the key for making 2PE-ISM mainstream.
Evolutionary model of protein secondary structure capable of revealing new biological relationships
Authors: Lai Jhih-Siang , Rost Burkhard , Kobe Bostjan , Bodén Mikael
Published: February 2019

Ancestral sequence reconstruction has had recent success in decoding the origins and the determinants of complex protein functions. However, phylo­genetic analyses of remote homologues must handle extreme amino-acid se­quence diversity resulting from extended periods of evolutionary change. We exploited the wealth of protein structures to develop an evolutionary model based on protein secondary structure. The approach follows the differences between discrete secondary structure states observed in modern proteins and those hypothesised in their immediate ancestors. We implemented maximum likelihood-based phylogenetic inference to reconstruct ancestral secondary structure. The predictive accuracy from the use of the evolutionary model surpasses that of comparative modelling and sequence-based prediction; the reconstruction extracts information not available from modern structures or the ancestral sequences alone. Based on a phylogenetic analysis of multiple protein families, we showed that the model can highlight relationships that are evolutionarily rooted in structure and not evident in amino acid-based analysis.
Drug screens of NGLY1 Deficiency worm and fly models reveal catecholamine, NRF2 and anti-inflammatory pathway activation as clinical approaches
Authors: Iyer Sangeetha , Mast Joshua D. , Tsang Hillary , Rodriguez Tamy P. , DiPrimio Nina , Prangley Madeleine , Sam Feba S. , Parton Zachary , Perlstein Ethan O.
Published: February 2019

N-glycanase 1/NGLY1 Deficiency is an ultra-rare and complex monogenic glycosylation disorder that affects fewer than 40 patients globally. NGLY1 Deficiency has been studied in model organisms such as yeast, worms, flies and mice. Proteasomal and mitochondrial homeostasis gene networks are controlled by the evolutionarily conserved transcriptional regulator Nrf1, whose activity requires deglycosylation by NGLY1. Hypersensitivity to the proteasome inhibitor bortezomib is a common phenotype observed in whole animal and cellular models of NGLY1 Deficiency. Here we describe unbiased phenotypic drug screens to identify FDA approved drugs, generally recognized as safe natural products and novel chemical entities that rescue growth and development of NGLY1-deficient worm and fly larvae treated with a toxic dose of bortezomib. We used image-based larval size and number assays for use in screens of a 2,560-member drug repurposing library and a 20,240-member lead discovery library. A total of 91 validated hit compounds from primary invertebrate screens were tested in a human cell line in a NRF2 activity assay. NRF2 is a transcriptional regulator that regulates cellular redox homeostasis and it can compensate for loss of Nrf1. Plant-based polyphenols comprise the largest class of hit compounds and NRF2 inducers. Catecholamines and catecholamine receptor activators comprise the second largest class of hits. Steroidal and non-steroidal anti-inflammatory drugs comprise the third largest class. Only one compound was active in all assays and species: the atypical antipsychotic and dopamine receptor agonist aripiprazole. Worm and fly models of NGLY1 Deficiency validate therapeutic rationales for activation of NRF2 and anti-inflammatory pathways based on results in mice and human cell models and suggest a novel therapeutic rationale for boosting catecholamine levels and/or signaling in the brain.
Probing Ligand and Cation Binding Sites in G-Quadruplex Nucleic Acids by Mass Spectrometry and Electron Photodetachment Dissociation Sequencing
Authors: Paul Dababrata , Marchand Adrien , Verga Daniela , Teulade-Fichou Marie-Paule , Bombard Sophie , Rosu Frédéric , Gabelica Valérie
Published: February 2019

Mass spectrometry provides exquisite detail on ligand and cation binding stoichiometries with a DNA target. The next important step is to develop reliable methods to determine the cation and ligand binding sites in each complex separated by the mass spectrometer. To circumvent the caveat of ligand derivatization for cross-linking, which may alter the ligand binding mode, we explored a tandem mass spectrometry (MS/MS) method that does not require ligand derivatization, and is therefore also applicable to localize metal cations. By obtaining more negative charge states for the complexes using supercharging agents, and by creating radical ions by electron photodetachment, oligonucleotide bonds become weaker than the DNA-cation or DNA-ligand noncovalent bonds upon collision-induced dissociation of the radicals. This electron photodetachment (EPD) method allows to locate the binding regions of cations and ligands by top-down sequencing of the oligonucleotide target. The very potent G-quadruplex ligands 360A and PhenDC3 were found to replace a potassium cation and bind close to the central loop of 4-repeat human telomeric sequences.
Pan-cancer mutational landscape of the PPAR pathway reveals universal patterns of dysregulated metabolism and interactions with tumor immunity and hypoxia
Authors: Chang Wai Hoong , Lai Alvina G.
Published: February 2019

Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear receptors that regulate lipid metabolism and bioenergetic demands within living systems. Consequently, aberrant expression of PPAR genes could predispose individuals to diseases including cancer. PPAR signaling exerts pleiotropic functions in cancer, yet, little is known about the interactions between genetic and transcriptional events of pathway genes in a pan-cancer context. Employing multidimensional datasets of over 18,000 patients involving 21 cancers, we performed systematic characterization on copy number alteration and differential transcript expression of 74 PPAR pathway genes. We identified 18 putative driver candidates demonstrating mutually exclusive patterns of loss- and gain-of-function phenotypes. These driver genes successfully predicted patient survival rates in bladder, renal, glioma, liver and stomach/esophageal cancers. Dysregulated PPAR signaling in these cancers converged on common downstream pathways associated with multiple metabolic processes. Moreover, clinically-relevant relationships between PPARs and hypoxia were observed where hypoxia further aggravates disease phenotypes in tumor subtypes with aberrant PPAR signaling. In glioma samples, including astrocytoma and oligoastrocytoma, PPAR hyperactivation is associated with immunosuppression through increased regulatory T cell expression. Our analysis reveals underappreciated levels of diversity and conservation in PPAR genes that could lay the groundwork for therapeutic strategies targeting tumor metabolism, immunity and hypoxia.
Parasites Mediate Condition-Dependent Sexual Selection for Local Adaptation in a Natural Insect Population
Authors: Gómez-Llano Miguel , Narasimhan Aaditya , Svensson Erik I.
Published: February 2019

Condition-dependent sexual selection has been suggested to reduce mutation load, and sexual selection might also accelerate local adaptation and promote evolutionary rescue through several ecological and genetic mechanisms. Research on condition-dependent sexual selection has mainly been performed in laboratory settings, while data from natural populations are lacking. One ecological factor that can cause condition-dependent sexual selection is parasitism. Here, we quantified ectoparasite load (Arrenurus water mites) in a natural population of the common bluetail damselfly (Ischnura elegans) over 15 years. We estimated parasite-mediated sexual selection in both sexes and investigated how parasite resistance and tolerance changed over time and influenced population density. Parasites reduced mating success in both sexes, but the effects were stronger in males than in females. The male fitness advantage of carrying fewer parasites was higher under experimental low-density conditions than under high-density field conditions, suggesting that male-male competition could reduce parasite-mediated sexual selection. We further show that population density declined during the study period, while parasite resistance and male fitness tolerance (fecundity) increased, suggestive of increasing local adaptation against parasites and ongoing evolutionary rescue. We suggest that condition-dependent sexual selection can facilitate population persistence and promote evolutionary rescue by increasing local adaptation against parasites.
CDK12 phosphorylates 4E-BP1 to enable mTORC1-dependent translation and mitotic genome stability
Authors: Choi Seung H. , Martinez Thomas F. , Kim Seongjae , Donaldson Cynthia , Shokhirev Maxim N. , Saghatelian Alan , Jones Katherine A.
Published: February 2019

The RNA polymerase II (RNAPII) C-terminal domain kinase, CDK12, regulates genome stability, expression of DNA repair genes, and cancer cell resistance to chemotherapy and immunotherapy. In addition to its role in mRNA biosynthesis of DNA repair genes, we show here that CDK12 phosphorylates the mRNA 5′ cap-binding repressor, 4E-BP1, to promote translation of mTORC1-dependent mRNAs. In particular, we found that phosphorylation of 4E-BP1 by mTORC1 (T37 and T46) facilitates subsequent CDK12 phosphorylation at two Ser–Pro sites (S65 and T70) that control the exchange of 4E-BP1 with eIF4G at the 5′ cap of CHK1 and other target mRNAs. RNA immunoprecipitation coupled with deep sequencing (RIP-seq) revealed that CDK12 regulates release of 4E-BP1, and binding of eIF4G, to many mTORC1 target mRNAs, including those needed for MYC transformation. Genome-wide ribosome profiling (Ribo-seq) further identified specific CDK12 “translation-only” target mRNAs, including many mTORC1 target mRNAs as well as many subunits of mitotic and centromere/centrosome complexes. Accordingly, confocal imaging analyses revealed severe chromosome misalignment, bridging, and segregation defects in cells deprived of CDK12 or CCNK. We conclude that the nuclear RNAPII-CTD kinase CDK12 cooperates with mTORC1, and controls a specialized translation network that is essential for mitotic chromosome stability.
Full real-space analysis of a dodecagonal quasicrystal
Authors: Schenk Sebastian , Zollner Eva Maria , Krahn Oliver , Schreck Berit , Hammer René , Förster Stefan , Widdra Wolf
Published: February 2019

The atomically resolved real-space structure of a long-range-ordered dodecagonal quasicrystal is determined based on scanning tunnelling microscopy. For the BaTiO3-derived oxide quasicrystal which spontaneously forms on a Pt(111) surface, 8100 atomic positions have been determined and are compared with an ideal Niizeki–Gähler tiling. Although the Niizeki–Gähler tiling has a complex three-element structure, the abundance of the triangle, square and rhomb tiling elements in the experimental data closely resembles the ideal frequencies. Similarly, the frequencies of all possible next-neighbour tiling combinations are, within the experimental uncertainty, identical to the ideal tiling. The angular and orientational distributions of all individual tiling elements show the characteristics of the dodecagonal quasicrystal. In contrast, the analysis of the orientation of characteristic and more complex tiling combinations indicates the partial decomposition of the quasicrystal into small patches with locally reduced symmetry. These, however, preserve the long-range quasicrystal coherence. The symmetry reduction from dodecagonal to sixfold is assigned to local interaction with the threefold substrate. It leads to atomic flips which preserve the number of quasicrystal tiling elements.
A 60-heme reductase complex from an anammox bacterium shows an extended electron transfer pathway
Authors: Dietl Andreas , Maalcke Wouter J. , Ferousi Christina , Jetten Mike S. M. , Kartal Boran , Barends Thomas R. M.
Published: February 2019

The hydroxylamine oxidoreductase/hydrazine dehydrogenase (HAO/HDH) protein family constitutes an important group of octaheme cytochromes c (OCCs). The majority of these proteins form homotrimers, with their subunits being covalently attached to each other via a rare cross-link between the catalytic heme moiety and a conserved tyrosine residue in an adjacent subunit. This covalent cross-link has been proposed to modulate the active-site heme towards oxidative catalysis by distorting the heme plane. In this study, the crystal structure of a stable complex of an HAO homologue (KsHAOr) with its diheme cytochrome c redox partner (KsDH) from the anammox bacterium Kuenenia stuttgartiensis was determined. KsHAOr lacks the tyrosine cross-link and is therefore tuned to reductive catalysis. The molecular model of the KsHAOr–KsDH complex at 2.6 Å resolution shows a heterododecameric (α6β6) assembly, which was also shown to be the oligomeric state in solution by analytical ultracentrifugation and multi-angle static light scattering. The 60-heme-containing protein complex reveals a unique extended electron transfer pathway and provides deeper insights into catalysis and electron transfer in reductive OCCs.
Multi-objective multi-facility green manufacturing closed-loop supply chain under uncertain environment
Authors: Karimi Behzad , Niknamfar Amir Hossein , Hassan Gavyar Babak , Barzegar Majid , Mohtashami Ali
Published: February 2019

Purpose

Today’s, supply chain production and distribution of products to improve the customer satisfaction in the shortest possible time by paying the minimum cost, has become the most important challenge in global market. On the other hand, minimizing the total cost of the transportation and distribution is one of the critical items for companies. To handle this challenge, this paper aims to present a multi-objective multi-facility model of green closed-loop supply chain (GCLSC) under uncertain environment. In this model, the proposed GCLSC considers three classes in case of the leading chain and three classes in terms of the recursive chain. The objectives are to maximize the total profit of the GCLSC, satisfaction of demand, the satisfactions of the customers and getting to the proper cost of the consumers, distribution centers and recursive centers.

Design/methodology/approach

Then, this model is designed by considering several products under several periods regarding the recovery possibility of products. Finally, to evaluate the proposed model, several numerical examples are randomly designed and then solved using non-dominated sorting genetic algorithm and non-dominated ranking genetic algorithm. Then, they are ranked by TOPSIS along with analytical hierarchy process so-called analytic hierarchy process-technique for order of preference by similarity to ideal solution (AHP-TOPSIS).

Findings

The results indicated that non-dominated ranked genetic algorithm (NRGA) algorithm outperforms non-dominated sorting genetic algorithm (NSGA-II) algorithm in terms of computation times. However, in other metrics, any significant difference was not seen. At the end, to rank the algorithms, a multi-criterion decision technique was used. The obtained results of this method indicated that NSGA-II had better performance than ones obtained by NRGA.

Originality/value

This study is motivated by the need of integrating the leading supply chain and retrogressive supply chain. In short, the highlights of the differences of this research with the mentioned studies are as follows: developing multi-objective multi-facility model of fuzzy GCLSC under uncertain environment and integrating the leading supply chain and retrogressive supply chain.
Does real exchange rate devaluation improve the current account balance of highly indebted low income countries?
Authors: Ayele Getaneh Mihret
Published: February 2019

Purpose

The purpose of this paper is to examine whether real exchange rate devaluation improves the current account balance of four highly indebted low-income countries of East Africa.

Design/methodology/approach

The pooled mean group (PMG) approach is used for panel data from four countries over the period 1970–2016. The paper also applied bound testing and ARDL model for time-series data from individual sample countries.

Findings

The panel PMG/ARDL estimation result reveals that real exchange rate devaluation has no significant impact on the current account balance, both in the short and long run. However, the time-series analysis using the bound testing and restricted ARDL estimation suggests that real exchange rate devaluation improves the current account balance in the long run for only Ethiopia. The overall empirical results reveal that the current account balance would improve with the rising domestic income while it deteriorates with increasing foreign income and external indebtedness in the long run.

Originality/value

The paper is original.
Understanding consumer ethics in China’s demographic shift and social reforms
Authors: Chen Wei-Fen , Wang Xue , Gao Haiyan , Hong Ying-Yi
Published: February 2019

Purpose

The purpose of this paper is to explore some specific, current social phenomena in China that may influence consumers’ ethical beliefs and practices, focusing on how some top-down, social and political changes could shape consumer behavior that needs to be understood in the Chinese context.

Design/methodology/approach

Extensive literature was critically reviewed to explore recent macro-societal reforms in China and their impact on consumers’ (un)ethical practices.

Findings

The authors lay out how China, a government-led society, underwent a series of political reforms resulting in demographic shifts that differentiate it from its western, industrialized counterparts. The authors connect these societal changes with Chinese characteristics to consumers’ ethical evaluations, forming a new angle to understand consumer ethics in China. The authors also draw on two empirical examples to illustrate the argument.

Originality/value

While consumer ethics are often explained by either cultural factors or individual variations, the authors discuss how one’s ethical practice is shaped by one’s social position, which is a product of national-level public policy. The discussions have ramifications for the study of consumers’ social class and ethical practices because they take into account the elusive social positions and ambiguous social class consciousness of the Chinese population that have resulted from social mobility. The discussions may give practitioners a better understanding of the ethical rationale behind consumers’ changing lifestyles especially in the Chinese context.
The importance of CSR initiatives in building customer support and loyalty
Authors: Ajina Ahmed Suhail , Japutra Arnold , Nguyen Bang , Syed Alwi Sharifah Faridah , Al-Hajla Ali H.
Published: February 2019

Purpose

The purpose of this paper is to examine how the perception of CSR influences different aspects of consumer behaviour, specifically focussing on the antecedents of perceived value, customer support and loyalty.

Design/methodology/approach

A total of 418 completed responses were obtained and provided the data to analyse and test the hypothesised research model. To test the hypotheses, structural equation modelling using PLS was employed.

Findings

Findings reveal that customer awareness of the current CSR initiatives to different stakeholder groups significantly influences their perceptions of what social initiatives are actually undertaken by firms for their economic, legal, ethical and philanthropic responsibility. In addition, customer views of what firms actually do in respect to social initiatives are significantly related to their level of CSR expectations. This indicates that the customers will always expect more from banks compared to what they actually do. Surprisingly, CSR perception is not directly related to customers’ loyalty, which contradicts the majority of previous studies indicating that CSR perception influences consumer behaviour.

Originality/value

This study provides an original contribution to the CSR body of knowledge, especially for developing countries where the awareness level is low. It also provides a deep understanding of the influence of CSR into consumer behaviour, as it investigates the influence of the full construct of CSR into customer loyalty. Finally, the study investigated the relationship between the perception and the expectation of CSR; this relationship has been neglected in previous studies, where either CSR perceptions or CSR expectations have been examined separately.
The reasoning behind infrastructure manager’s choice of procurement instruments
Authors: Plantinga Henrico , Voordijk Hans , Doree Andre
Published: February 2019

Purpose

The purpose of this paper is to show that for frequently procuring public clients: the reasoning behind the use of procurement instruments is a process in its own right that requires managerial and scientific attention; modeling this process contributes to making sensible procurement choices; and managing this process is a relevant factor in the client’s development toward strategic procurement.

Design/methodology/approach

A model is developed to conceptualize the reasoning behind procurement instruments. Using this model in a case study, the reasoning behind the evolution of a particular procurement instrument as applied by a public infrastructure management organization is reconstructed.

Findings

The case study results show that an initially explicitly formulated set of main reasons for operating a qualification system can implicitly evolve over time into a different set of reasons. From a managerial point of view, explication of implicit reasons is important to both avoid the risk that the real value of the procurement instrument remains undetected as well as properly assess its strategic alignment with higher level strategies. The conceptual model proves to be a useful tool to support that.

Originality/value

Bringing the reasoning behind the use of procurement instruments to the fore, this study explores an area of construction procurement research that is positioned between the disciplines of purchasing and supply management, knowledge management and strategic management.
Biases in construction project dispute resolution
Authors: Cheung Sai On , Li Keyao
Published: February 2019

Purpose

This study aims to propose a framework of bias in construction project dispute resolution (CPDR hereafter).

Design/methodology/approach

With reference to the literatures on effects of bias, manifestations of bias in CPDR were developed. Based on data obtained from construction professionals about their frequency of having these bias manifestations, the underlying constructs of biased behaviors were explored by a principal component factor analysis. A confirmatory factor analysis was further conducted to validate the framework of bias in CPDR.

Findings

Four types of bias were identified as the constructs that underlie biased behaviors in CPDR. These four biases were included in the bias framework proposed: preconception, self-affirmation, optimism and interest-oriented. The potency of these types of bias was also evaluated.

Practical implications

First, the findings inform that the existence of bias in CPDR is real. Early detection allows management to intervene and steer CPDR team back to rational courses. Second, this study suggests optimizing CPDR procedures to diminish the chance of bias occurring.

Originality/value

Bias is almost an uncharted area in CPDR. The study fills this research gap by conceptualizing the underlying constructs of biased behaviors. The findings inform construction professionals of the likelihood of practicing biased behaviors in CPDR. Repeated dispute decisions in the commonly used multi-tiered dispute resolution process would enable the creeping in of biases.
Risk of excavators overturning
Authors: Edwards David , Parn Erika A. , Sing Michael C.P. , Thwala Wellington Didibhuku
Published: February 2019

Purpose

Tracked hydraulic excavators are versatile and ubiquitous items of off-highway plant and machinery that are utilised throughout the construction industry. Each year, a significant number of excavators overturn whilst conducting a lifting operation, causing damage to property, personnel injury or even fatality. The reasons for the overturn are myriad, including: operational or environmental conditions; machine operator acts or omissions; and/or inadequate site supervision. Furthermore, the safe working load (SWL) figure obtained from manufacturer guidance and utilised in lift plans is based upon undertaking a static load only. The purpose of this paper is to determine whether the SWL is still safe to be used in a lift plan when slewing a freely suspended (dynamic) load, and, if not, whether this may be a further contributory factor to overturn incidents.

Design/methodology/approach

Previous research has developed a number of machine stability test regimes but these were largely subjective, impractical to replicate and failed to accurately measure the “dynamic” horizontal centrifugal force resulting from slewing the load. This research contributes towards resolving the stability problem by critically evaluating existing governing standards and legislation, investigating case studies of excavator overturn and simulating the dynamic effects of an excavator when slewing a freely suspended load at high rotations per minute (rpm). To achieve this, both the static load and horizontal centrifugal force from slewing this load were calculated for six randomly selected cases of an excavator, with different arm geometry configurations.

Findings

The results from the six cases are presented and a worked example of one is detailed to demonstrate how the results were derived. The findings reveal that the SWL quoted on an excavator’s lift rating chart considerably underestimates the extra forces experienced by the machine when an additional dynamic load is added to the static load whilst lifting and slewing a freely suspended load.

Originality/value

This work presents the first attempt to accurately model excavator stability by taking consideration of the dynamic forces caused by slewing a freely suspended load and will lead to changes in the way that industry develops and manages lift plans. Future research proposes to vary the weight of load, arm geometry and rpm to predict machine stability characteristics under various operational conditions, and exploit these modelling data to populate pre-programmed sensor-based technology to monitor stability in real time and automatically restrict lift mode operations.
A hybrid approach to optimize initial design strategies for pre-sale housing projects
Authors: Juan Yi-Kai , Lin I-Chieh , Tsai Ji-Xuan
Published: February 2019

Purpose

The purpose of this paper is to propose a hybrid decision-making model for optimizing the initial design strategies of pre-sales housing, identifying factors affecting the initial design of housing, and developing different initial design approaches and strategies based on buyers’ preferences.

Design/methodology/approach

Indicators and factors in line with the local initial planning and design are created according to the design quality indicator framework. The important indicators and factors are screened out preliminarily with the fuzzy Delphi method and decision-making trial and evaluation laboratory based analytic network process. The performances of two actual cases under similar site conditions are checked with regard to the overall residential sales rate and time on the market (TOM).

Findings

The result shows that the proposed model can effectively improve the sales rate, shorten the TOM and better complies with buyer design strategy demands, and thus positively correlating to economic value.

Originality/value

Pre-sales make possible the customized strategy of allowing future residents to participate in the housing design process. However, buyers’ participation in the design process is highly limited, and developers usually determine their planning and initial residential design strategies based on experience and intuition. With the proposed approach, the initial residential design of a project can be effectively intervened, so that home users can truly participate in the design, and the residential construction service can be provided in a unique, but non-universal way.
Exploring the interactions among factors impeding the diffusion of prefabricated building technologies
Authors: Gan Xiao-Long , Chang Rui-Dong , Langston Craig , Wen Tao
Published: February 2019

Purpose

The purpose of this paper is to identify the interactions of factors impacting the widespread adoption of prefabricated building technologies and the intervention strategies to facilitate the development of prefabrication based on fuzzy cognitive maps (FCMs).

Design/methodology/approach

Through in-depth interviews with six stakeholder groups, namely, the government, developers, designers, contractors, manufacturers and researchers, 13 critical factors were identified and used to construct stakeholder-grouped FCMs, which were further aggregated into a collective FCM. The complexity and density of the collective FCM and the centrality of factors in the FCM were examined. Subsequently, a series of “what-if” simulations of the collective FCM were conducted to analyze the effectiveness of different interventions in promoting prefabrication.

Findings

The results show that three factors including market demand, cost, and policies and regulations have been mentioned by all stakeholder groups. However, these factors were ranked differently by stakeholder groups, implying that different stakeholder groups perceive the barriers to prefabricated building technologies differently. FCM simulations show that strengthening policies and regulations yield the strongest overall effect stimulating prefabrication, alleviating the organizational and environmental barriers more than the technological barriers, while improving the knowledge and expertise alleviate the technological barriers more. These measures need to be accompanied by other approaches, such as reducing cost and improving quality.

Research limitations/implications

It is a tough task to promote prefabrication as it is affected by numerous barriers with complex interactions, which have been overlooked by previous studies. This study clearly shows which strategy could tackle which barriers to prefabrication through the FCM simulations. This provides valuable references for the enterprises’ decision making and the governments’ policy making to facilitate the diffusion of prefabricated building technologies.

Originality/value

Few studies aim to analyze the interactions among the barriers to prefabrication, while this study specifically investigates this issue by illustrating the complex interactions using FCMs. Few studies also aim to identify the intervention strategies promoting prefabrication based on a quantitative approach, while this study employs FCM simulations to directly simulate the effectiveness of different strategies to facilitate prefabrication in a quantitative manner.
Effects of team diversity on project performance in construction projects
Authors: Wu Guangdong , Zhao Xianbo , Zuo Jian , Zillante George
Published: February 2019

Purpose

The purpose of this paper is fourfold: first, to investigate the effect of team diversity on different types of conflicts; second, to determine if team diversity is significantly correlated with project performance; third, to investigate the mediating effect of project conflicts on the relationship between team diversity and project performance and fourth, to examine the relationship between different types of conflicts and project performance in construction projects.

Design/methodology/approach

A theoretical model was developed and a questionnaire survey was conducted with 246 professionals. The structural equation modeling technique was applied to analyze the data.

Findings

The results showed that: team diversity was positively associated with project performance; the introduction of conflicts significantly weakened the effect of diversity on performance; conflicts have both constructive and destructive effects on project performance; and team diversity affected project performance through the mediating effects of task conflict and relationship conflict, thus adding both positive and negative effects on performance.

Research limitations/implications

There are other factors which may affect conflicts and project performance such as communication, trust and contract. Future research could be conducted to determine the role of these variables in determining the effects of team diversity on performance.

Practical implications

It is necessary to reduce the relationship conflict whereas maintaining a “healthy” level of task conflict. In light of this, the conclusions of this study highlight practical implications as follows: project teams should attach importance to diverse partner selection and select cooperative partners whose value orientations are similar; when implementing a construction project, the structure of diverse project teams should keep relatively stable, avoiding too many teams entering or exiting the project in a short period; project teams should make greater efforts to deal with destructive conflicts via relational governance such as trust and communication.

Originality/value

This study contributes to the literature in three areas. First, this study investigated the dynamic mechanism between team diversity, conflicts and performance in construction projects. Second, this study contributes to the body of knowledge on validating the mediating effects of conflicts on the relationship between team diversity and performance. Third, this study validated the positive and negative effects of team diversity on performance with different types of conflicts as mediation variables in construction projects.
Mapping the knowledge domains of value management: a bibliometric approach
Authors: Ekanayake E.M.A.C. , Shen Geoffrey , Kumaraswamy Mohan M.
Published: February 2019

Purpose

The purpose of this paper is to review the state-of-the-art of literature of value management (VM) and to map the VM domain to provide a launch pad for further knowledge development and dissemination.

Design/methodology/approach

This study employed CiteSpace bibliometric analysis software to systematically, comprehensively and accurately review the VM-related literature and to map the VM knowledge domain.

Findings

The results reveal the current VM knowledge base, clusters, research hotspot, and the evolutionary trajectory while contributing to the development of VM knowledge by providing a dynamic platform for integrating future developments in research.

Originality/value

The contribution of this paper to scientific VM knowledge is, therefore, a quantitative and accurate VM knowledge map based on a bibliometric analysis of data from the VM knowledge base, domains and evolution. The findings can be generalised and used as an effective knowledge mapping tool in a specific field of study that could complement and add significant value to the often adopted more traditional literature reviews. This study further recommends that the proposed knowledge map be frequently updated by similar future studies to fill gaps that arise with changing needs, priorities and contexts, as well as to identify corresponding future demands in the VM research domain.