bluuebunny/crossref_metadata_2025 huggingface dataset:
Exponential trajectories, cell size fluctuations and the adder property in bacteria follow from simple chemical dynamics and division control
Authors: Pandey Parth Pratim , Singh Harshant , Jain Sanjay
Published: December 2018

Experiments on steady state bacterial cultures have uncovered several quantitative regularities at the system level. These include, first, the exponential growth of cell size with time and the balanced growth of intracellular chemicals between cell birth and division, which are puzzling given the nonlinear and decentralized chemical dynamics in the cell. We model a cell as a set of chemical populations undergoing nonlinear mass action kinetics in a container whose volume is a linear function of the chemical populations. This turns out to be a special class of dynamical system that generically has attractors in which all populations grow exponentially with time at the same rate. This explains exponential balanced growth of bacterial cells without invoking any regulatory mechanisms and suggests that this could be a robust property of protocells as well. Second, we consider the hypothesis that cells commit themselves to division when a certain internal chemical population reaches a threshold of N molecules. We show that this hypothesis leads to a simple explanation of some of the variability observed across cells in a bacterial culture. In particular it reproduces the adder property of cell size fluctuations observed recently inE. coli, the observed correlations between interdivision time, birth volume and added volume in a generation, and the observed scale of the fluctuations (CV ~ 10-30%) when N lies between 10 and 100. Third, upon including a suitable regulatory mechanism that optimizes the growth rate of the cell, the model reproduces the observed bacterial growth laws including the dependence of the growth rate and ribosomal protein fraction on the medium. Thus, the models provide a framework for unifying diverse aspects of bacterial growth physiology under one roof. They also suggest new questions for experimental and theoretical enquiry.
Decreased grey matter volume in mTBI patients with post-traumatic headache compared to headache-free mTBI patients and healthy controls: a longitudinal MRI study
Authors: Burrowes Shana A.B. , Sours Rhodes Chandler , Meeker Timothy J. , Greenspan Joel D. , Gullapalli Rao P. , Seminowicz David A.
Published: December 2018

Background

Traumatic brain injury (TBI) occurs in 1.7 million people annually and many patients go on to develop persistent disorders including post-traumatic headache (PTH). PTH is considered chronic if it continues past 3 months. In this study we aimed to identify changes in cerebral grey matter volume (GMV) associated with PTH in mild TBI patients.

Methods

50 mTBI patients (31 Non-PTH; 19 PTH) underwent MRI scans: within 10 days post-injury, 1 month, 6 months and 18 months. PTH was assessed at visit 4 by a post-TBI headache questionnaire. Healthy controls (n=21) were scanned twice 6 months apart.

Results

Compared to non-PTH, PTH patients had decreased GMV across two large clusters described as the right anterior-parietal (p=0.012) and left temporal-opercular (p=0.027). Compared to healthy controls non-PTH patients had decreased GMV in the left thalamus (p=0.047); PTH patients had decreased GMV in several extensive clusters: left temporal-opercular (p=0.003), temporal-parietal (p=0.041), superior frontal gyrus (p=0.008) and right middle frontal/superior frontal gyrus (0.004) and anterior-parietal (p=0.003).

Conclusion

Differences between PTH and non-PTH patients were most striking at early time points. These early changes may be associated with an increased risk of PTH. Patients with these changes should be monitored for chronic PTH.
Predatory plants and patchy cows: modeling cattle interactions with toxic larkspur amid variable heterogeneity
Authors: Jablonski Kevin , Boone Randall , Meiman Paul
Published: December 2018

The most common explanations for the evolution and persistence of herd behavior in large herbivores relate to decreased risk of predation. However, poisonous plants such as larkspur (Delphinium spp.) can present a threat comparable to predation. In the western United States, larkspur diminishes the economic and ecological sustainability of cattle production by killing valuable animals and restricting management options. Recommendations for mitigating losses have long focused on seasonal avoidance of pastures with larkspur, despite little evidence that this is practical or effective. Our ongoing research points to the cattle herd itself as the potential solution to this seemingly intractable challenge and suggests that larkspur and forage patchiness may drive deaths. In this paper, we present an agent-based model that incorporates neutral landscape models to assess the interaction between plant patchiness and herd behavior within the context of poisonous plants as predator and cattle as prey. The simulation results indicate that larkspur patchiness is indeed a driver of toxicosis and that highly cohesive herds can greatly reduce the risk of death in even the most dangerous circumstances. By placing the results in context with existing theories about the utility of herds, we demonstrate that grouping in large herbivores can be an adaptive response to patchily distributed poisonous plants. Lastly, our results hold significant management-relevant insight, both for cattle producers managing grazing in larkspur habitat and in general as a call to reconsider the manifold benefits of herd behavior among domestic herbivores.
Renal medullary carcinomas depend uponSMARCB1loss and are sensitive to proteasome inhibition
Authors: Hong Andrew L. , Tseng Yuen-Yi , Wala Jeremiah , Kim Won Jun , Kynnap Bryan D. , Doshi Mihir B. , Kugener Guillaume , Sandoval Gabriel J. , Howard Thomas P. , Li Ji , Yang Xiaoping , Tillgren Michelle , Ghandi Mahmoud , Sayeed Abeer , Deasy Rebecca , Ward Abigail , McSteen Brian , Labella Katherine M. , Keskula Paula , Tracy Adam , Connor Cora , Clinton Catherine M. , Church Alanna J. , Crompton Brian D. , Janeway Katherine A. , Hare Barbara Van , Sandak David , Gjoerup Ole , Bandopadhayay Pratiti , Clemons Paul A. , Schreiber Stuart L. , Root David E. , Gokhale Prafulla C. , Chi Susan N. , Mullen Elizabeth A. , Roberts Charles W. M. , Kadoch Cigall , Beroukhim Rameen , Ligon Keith L. , Boehm Jesse S. , Hahn William C.
Published: December 2018

Renal medullary carcinoma (RMC) is a rare and deadly kidney cancer in patients of African descent with sickle cell trait. Through direct-to-patient outreach, we developed genomically faithful patient-derived models of RMC. Using whole genome sequencing, we identified intronic fusion events in oneSMARCB1allele with concurrent loss of the other allele, confirming that SMARCB1 loss occurs in RMC. Biochemical and functional characterization of these RMC models revealed that RMC depends on the loss ofSMARCB1for survival and functionally resemble other cancers that harbor loss ofSMARCB1, such as malignant rhabdoid tumors or atypical teratoid rhabdoid tumors. We performed RNAi and CRISPR-Cas9 loss of function genetic screens and a small-molecule screen and identifiedUBE2Cas an essential gene in SMARCB1 deficient cancers. We found that the ubiquitin-proteasome pathway was essential for the survival of SMARCB1 deficient cancersin vitroandin vivo.Genetic or pharmacologic inhibition of this pathway leads to G2/M arrest due to constitutive accumulation of cyclin B1. These observations identify a synthetic lethal relationship that may serve as a therapeutic approach for patients with SMARCB1 deficient cancers.
Exenatide reverts the high-fat-diet-induced impairment of BDNF signaling and inflammatory response in an animal model of Alzheimer’s disease
Authors: Bomba Manuela , Granzotto Alberto , Castelli Vanessa , Lattanzio Rossano , Cimini Annamaria , Sensi Stefano L.
Published: December 2018

Background

preclinical, clinical, and epidemiological evidence support the notion that Alzheimer’s disease(AD) is a multifactorial condition in which, along with β-amyloid (Aβ) and tau-related pathology, the synergistic activity of genetic, environmental, vascular, metabolic, and inflammatory factors promote the onset and progression of the disease. Epidemiological evidence indicate that glucose intolerance, deficits in insulin secretion or type 2 diabetes mellitus (T2DM) participate in increasing the risk of developing cognitive impairment or dementia. A pivotal role in the process is played by insulin as the hormone critically regulates brain functioning. GLP-1, the glucagon-like peptide 1, facilitates insulin signaling, regulates glucose homeostasis, and modulates synaptic plasticity. Exenatide is a GLP-1R agonist, characterized by an extended half-life, employed in T2DM. However, exenatide has also been shown to affect the signaling of the brain-derived neurotrophic factor (BDNF), synaptic plasticity, and cognitive performances in animal models of brain aging and neurodegeneration.

Methods

in this study, we tested whether exenatide exerts neuroprotection in a preclinical AD model set to mimic the clinical complexity of the human disease. To that aim, we investigated the effects of 3-month exenatide treatment in 3xTg-AD mice challenged for six months with a high-fat diet (HFD). Endpoints of the study were variations in systemic metabolism, insulin and neurotrophic signaling, neuroinflammation, levels of Aβ and tau pathology as well as changes in cognitive performances.

Findings and interpretation

results of the study indicate that exenatide reverts the adverse changes of BDNF signaling and the neuroinflammation status of 3xTg-AD mice undergoing HFD.
Boundary conditions for early life converge to an organo-sulfur metabolism
Authors: Goldford Joshua E. , Hartman Hyman , Marsland Robert , Segrè Daniel
Published: December 2018

It has been suggested that a deep memory of early life is hidden in the architecture of metabolic networks, whose reactions could have been catalyzed by small molecules or minerals prior to genetically encoded enzymes (1–6). A major challenge in unraveling these early steps is assessing the plausibility of a connected, thermodynamically consistent proto-metabolism under different geochemical conditions, which are still surrounded by high uncertainty. Here we combine network-based algorithms (9, 10) with physicochemical constraints on chemical reaction networks to systematically show how different combinations of parameters (temperature, pH, redox potential and availability of molecular precursors) could have affected the evolution of a proto-metabolism. Our analysis of possible trajectories indicates that a subset of boundary conditions converges to an organo-sulfur-based proto-metabolic network fueled by a thioester- and redox-driven variant of the reductive TCA cycle, capable of producing lipids and keto acids. Surprisingly, environmental sources of fixed nitrogen and low-potential electron donors seem not to be necessary for the earliest phases of biochemical evolution. We use one of these networks to build a steady-state dynamical metabolic model of a proto-cell, and find that different combinations of carbon sources and electron acceptors can support the continuous production of a minimal ancient “biomass” composed of putative early biopolymers and fatty acids.
Genetic and physical interactions between the organellar mechanosensitive ion channel homologs MSL1, MSL2, and MSL3 reveal a role for inter-organellar communication in plant development
Authors: Lee Josephine , Wilson Margaret , Richardson Ryan , Haswell Elizabeth
Published: December 2018

Plant development requires communication on many levels, including between cells and between organelles within a cell. For example, mitochondria and plastids have been proposed to be sensors of environmental stress and to coordinate their responses. Here we present evidence for communication between mitochondria and chloroplasts during leaf and root development, based on genetic and physical interactions between three Mechanosensitive channels of Small conductance-Like (MSL) proteins from Arabidopsis thaliana. MSL proteins are Arabidopsis homologs of the bacterial Mechanosensitive channel of Small conductance (MscS), which relieves cellular osmotic pressure to protect against lysis during hypoosmotic shock. MSL1 localizes to the inner mitochondrial membrane, while MSL2 and MSL3 localize to the inner plastid membrane and are required to maintain plastid osmotic homeostasis during normal growth and development. In this study, we characterized the phenotypic effect of a genetic lesion in MSL1, both in wild type and in msl2 msl3 mutant backgrounds. msl1 single mutants appear wild type for all phenotypes examined. The characteristic leaf rumpling in msl2 msl3 double mutants was exacerbated in the msl1 msl2 msl3 triple mutant. However, the introduction of the msl1 lesion into the msl2 msl3 mutant background suppressed other msl2 msl3 mutant phenotypes, including ectopic callus formation, accumulation of superoxide and hydrogen peroxide in the shoot apical meristem, decreased root length, and reduced number of lateral roots. All these phenotypes could be recovered by molecular complementation with a transgene containing a wild type version of MSL1. In yeast-based interaction studies, MSL1 interacted with itself, but not with MSL2 or MSL3. These results establish that the abnormalities observed in msl2 msl3 double mutants is partially dependent on the presence of functional MSL1 and suggest a possible role for communication between plastid and mitochondria in seedling development.
Hfq Globally Binds and Destabilizes the bound sRNAs and mRNAs in Yersinia pestis
Authors: Han Yanping , Chen Dong , Yan Yanfeng , Wang Hongduo , Liu Zizhong , Xue Yaqiang , Yang Ruifu , Zhang Yi
Published: December 2018

Hfq is a ubiquitous Sm-like RNA binding protein in bacteria involved in physiological fitness and pathogenesis, while its in vivo binding natures still remain elusive. Here we reported the first study of the Hfq-bound RNAs map in Yersinia pestis, the causative agent of a kind of plague, by using Cross-Linking Immunoprecipitation coupled with deep sequencing (CLIP-Seq) approach. We show that Hfq binds over 80% mRNAs of Y. pestis, and also globally binds non-coding sRNAs encoded by the intergenic, antisense, and the 3’ regions of mRNAs. Hfq U-rich stretch is highly enriched in sRNAs, while motifs partially complementary to AGAAUAA and GGGGAUUA are enriched in both mRNAs and sRNAs. Hfq binding motifs are enriched at both terminal sites and in the gene body of mRNAs. Surprisingly, a large fraction of the sRNA and mRNA regions bound by Hfq and those downstream are destabilized, likely via a 5’P-activated RNase E degradation pathway and consistent with Hfq-facilitated sRNA-mRNA base-pairing and the coupled degradation in Y. pestis. These results together have presented a high-quality Hfq-RNA interaction map in Y. pestis, which should be important for further deciphering the regulatory role of Hfq-sRNAs in Y. pestis.

AUTHOR SUMMARY

Discovered in 1968 as an Escherichia coli host factor that was essential for replication of the bacteriophage Qβ, the Hfq protein is a ubiquitous and highly abundant RNA binding protein in many bacteria. Under the assistance of Hfq, small RNAs in bacteria play important role in regulating the stability and translation of mRNAs by base-pairing. In this study, we want to elucidate the Hfq assisted sRNA-mRNA regulation in Yersinia pestis. A global map of Hfq interaction sites in Y. pestis was obtained by sequencing of cDNAs converted from the Hfq-bound RNA fragments using UV cross-linking coupled immunoprecipitation technology. We demonstrate that Hfq could hundreds of sRNAs and the majority of mRNAs in living Y. pestis. The enriched binding motifs in sRNAs and mRNA are significantly complementary to each other, suggesting a general base-pairing mechanism for sRNA-mRNA interaction. The Hfq-bound sRNA and mRNA regions were both destabilized. The results suggest that Hfq binding facilitates sRNA-mRNA base-pairing and coordinates their degradation, which might enable Hfq to surveil the hemostasis of most mRNAs in bacteria.
Proteome-wide solubility and thermal stability profiling reveals distinct regulatory roles for ATP
Authors: Sridharan Sindhuja , Kurzawa Nils , Werner Thilo , Guenthner Ina , Helm Dominic , Huber Wolfgang , Bantscheff Marcus , Savitski Mikhail M
Published: December 2018

Nucleotide triphosphates (NTPs) regulate numerous biochemical processes in cells as (co-)substrates, allosteric modulators, biosynthetic precursors, and signaling molecules. Apart from its roles as energy source fueling cellular biochemistry, adenosine triphosphate (ATP), the most abundant NTP in cells, has been reported to affect macromolecular assemblies, such as protein complexes and membrane-less organelles. Moreover, both ATP and guanosine triphosphate (GTP) have recently been shown to dissolve protein aggregates. However, system-wide studies to characterize NTP- interactions under conditions approximating the native cellular environment are lacking, which limits our perspective of the diverse physiological roles of NTPs. Here, we have mapped and quantified proteome-wide NTP-interactions by assessing thermal stability and solubility of proteins using mechanically disrupted cells. Our results reveal diverse biological roles of ATP depending on its concentration. We found that ATP specifically interacts with proteins that utilize it as substrate or allosteric modulator at doses lower than 500 μM, while it affects protein-protein interactions of protein complexes at mildly higher concentrations (between 1-2 mM). At high concentrations (> 2 mM), ATP modulates the solubility state of a quarter of the insoluble proteome, consisting of positively charged, intrinsically disordered, nucleic acid binding proteins, which are part of membrane-less organelles. The extent of solubilization depends on the localization of proteins to different membrane-less organelles. Furthermore, we uncover that ATP regulates protein-DNA interactions of the Barrier to autointegration factor (BANF1). Our data provides the first quantitative proteome-wide map of ATP affecting protein structure and protein complex stability and solubility, providing unique clues on its role in protein phase transitions.
Prevalence and genotype-specific distribution of Human papillomavirus in Burundi according to HIV status and urban or rural residence and its implications for control
Authors: NDIZEYE Zacharie , Vanden Broeck Davy , Lisbeth Ramokone Lebelo , Bogers Johannes , Benoy Ina , Van Geertruyden Jean-Pierre
Published: December 2018

Background

Human papillomaviruses are the most important causative agents for invasive cervical cancer development. HPV type-specific vaccination and HPV cervical cancer screening methods are being widely recommended to control the disease but the epidemiology of the circulating HPV types may vary locally. The circulating HPV-strains have never been assessed in Burundi. This study determined the prevalence and genotype-specific distribution of HPV in four different strata in Burundi: HIV-infected or non-infected and women living in rural or urban areas. Implications for HPV diagnosis and vaccine implementation was discussed.

Methods

Four cross-sectional surveys were conducted in Burundi (2013 in a rural area and 2016 in urban area) among rural and urban HIV-infected and uninfected women. Cytology and HPV genotyping was performed to screen women for cervical cancer lesions. Risk factors for HPV infection and cervical cancer lesions were determined using logistic regression model.

Results

HPV prevalence was very high in urban area with significant differences between HIV-positive and negative women (p<0.0001). In fact, 45.7% of HIV-positive participants were infected with any HPV type and all were infected with at least one HR/pHR-HPV type. Among the HIV-negative participants, 13.4% were HPV-infected, of whom, only 4 women (2.7%) were infected with HR/pHR-HPV types. In rural, HPV infection did not significantly differ between HIV-positive and negative women (30.0% and 31.3% respectively; p=0.80).

In urban, multiple infections with HR/pHR-HPV types were detected in 13.9% and 2.7% among HIV-positive and negative women respectively (p<0.0001), whereas in rural, multiple infections with HR/pHR-HPV types were detected in 4.7% and 3.3% of HIV positive and negative women respectively (p=0.56).

The most prevalent HR/pHR-HPV types in HIV-positive urban women were HPV 52, 51 and 56. In the HIV-negative urban women, the most prevalent HR/pHR-HPV types were HPV 66, 67 and 18. In HIV-positive rural women, the most prevalent HR/pHR-HPV types were HPV 66, 16 and 18. In the HIV-negative rural women, the most prevalent HR/pHR-HPV types were HPV 16, 66 and 18. Independent risk factors associated with cervical lesions were HPV and HIV infections.

Conclusions

There is a high burden of HR/pHR-HPV infections, in particular among HIV-infected urban women. The study points out the need to introduce a comprehensive cervical cancer control program adapted to the context. This study shows that the nonavalent vaccine covers most of the HR/pHR-HPV infections in rural and urban areas among HIV-infected and uninfected women.
Separate Polycomb Response Elements control chromatin state and activation of the vestigial gene
Authors: Ahmad Kami , Spens Amy E
Published: December 2018

Patterned expression of many developmental genes is specified by transcription factor gene expression, but is thought to be refined by chromatin-mediated repression. Regulatory DNA sequences called Polycomb Response Elements (PREs) are required to repress some developmental target genes, and are widespread in genomes, suggesting that they broadly affect developmental programs. While PREs in transgenes can nucleate trimethylation on lysine 27 of the histone H3 tail (H3K27me3), none have been demonstrated to be necessary at endogenous chromatin domains. This failure is thought to be due to the fact that most endogenous H3K27me3 domains contain many PREs, and individual PREs may be redundant. In contrast to these ideas, we show here that PREs near the wing selector gene vestigial have distinctive roles at their endogenous locus, even though both PREs are repressors in transgenes. First, a PRE near the promoter is required for vestigial activation and not for repression. Second, only the distal PRE contributes to H3K27me3, but even removal of both PREs does not eliminate H3K27me3 across the vestigial domain. Thus, endogenous chromatin domains appear to be intrinsically marked by H3K27me3, and PREs appear required to enhance this chromatin modification to high levels at inactive genes.
Schistosoma mansoni infection and risk factors among fishermen at Lake Hawassa, Southern Ethiopia
Authors: Menjetta Tadesse , Dana Daniel , Debalke Serkadis
Published: December 2018

Schistosomiasis/Bilharziasis is one of the neglected tropical parasitic diseases caused by different species of genus schistosoma. Among the species, S.mansoni (causative agents of intestinal schistosomiasis) is one of the causes of severe intestinal parasitic infections with high public and medical importance in Ethiopia. There is scarcity of information about the status of S.mansoni infection among the fisherman in the present study area and in the country at large. Therefore this study was designed to determine the prevalence and risk factors of S.mansoni infection among fishermen at Lake Hawassa, southern Ethiopia. A cross-sectional study was conducted among the fishermen from April to June 2013 in Hawassa, Southern Ethiopia. A total of 243 fishermen were included by Systematic Random Sampling from the lists of the fishermen members in the registration book of fishermen associations in the Hawassa Town. Data on socio-demographic features and risk factors were collected by using semi-structured questionnaires. Stool samples were collected and processed using Kato-Katz thick smear techniques and examined between 30- 40 minute for hook worm and after 24 hours for S.mansoni and other soil transmitted helminths (STHs). The overall prevalence of S.mansoni among the fishermen was 29.21% (71/243) and the mean intensity of infection was 158.88 eggs per gram (EPG). The prevalence of intestinal helminths including S.mansoni was 69.54% (169/243). Moreover, the prevalence of soil transmitted helminths (STHs) were 40.74% (99/243), 35.80% (87/243) and 5.76% (14/243) for A. lumbricoides, T. trichiura and hookworm species, respectively. Almost similar prevalence of S.mansoni, 31.82%, 31.75%, 31.94% were recorded in age groups of 15-19, 20-24 and 25-29 years, respectively. Fishermen who are swimming always were 2.92 times [95% CI: 1.554, 5.502] more likely to acquire S.mansoni infection than other water contacting habit of the study participants. The results of current investigation indicated the moderate endemicity of S.mansoni among the fishermen at Lake Hawassa, southern Ethiopia. Fishermen could be the potential risk group for S.mansoni infection and might be responsible for the transmission of S.mansoni to other segments of the communities. Since high prevalence of STH were recorded among the fishermen, integrated prevention and control strategies from different sectors might be important to tackle the problem.
Key words: S.mansoni, Soil transmitted helminths, Fishermen, Lake Hawassa, Ethiopia
Lessening of porcine epidemic diarrhoea virus susceptibility in piglets after editing of the CMP-N-glycolylneuraminic acid hydroxylase gene with CRISPR/Cas9 to nullify N-glycolylneuraminic acid expression
Authors: Tu Ching-Fu , Chuang Chin-kai , Hsiao Kai-Hsuan , Chen Chien-Hong , Chen Chie-Min , Peng Su-Hei , Su Yu-Hsiu , Chiou Ming-Tang , Yen Chon-Ho , Hung Shau-Wen , Yang Tien-Shuh , Chen Chuan-Mu ,   Ching-Fu Tu, Chin-kai Chuang, Kai-Hsuan Hsiao, Chien-Hong Chen, Chie-Min Chen, Su-Hei Peng, Yu.-Hsiu
Published: December 2018

Porcine epidemic diarrhoea virus (PEDV) devastates the health of piglets but may not infect piglets whose CMP-N-glycolylneuraminic acid hydroxylase (CMAH) gene mutated (knockouts, KO) by using CRISPR/Cas9 gene editing techniques. This hypothesis was tested by using KO piglets challenged with PEDV. Two single-guide RNAs targeting the CMAH gene and Cas9 mRNA were microinjected into the cytoplasm of newly fertilized eggs; 4 live founders generated and proven to be biallelic KO, lacking detectable N-glycolylneuraminic acid (NGNA). The founders were bred, and homozygous offspring were obtained. Two-day-old (in exps. I and III) and 3-day-old (in exp. II) KO and wild-type (WT) piglets were inoculated with TCID50 1x103 PEDV and then fed 20 mL of infant formula (in exps. I and II) or sow’s colostrum (in exp. III) every 4 hours. In exp. III, the colostrum was offered 6 times and was then replaced with Ringer/5% glucose solution. At 72 hours post-PEDV inoculation (hpi), the animals were euthanized for necropsy, and their intestines were sampled. In all 3 experiments, the piglets showed apparent outward clinical manifestations suggesting that infection occurred despite the CMAH KO. In exp. I, all 6 WT piglets and only 1 of 6 KO piglets died at 72 hpi. Histopathology and immunofluorescence staining showed that the villus epithelial cells of WT piglets were severely exfoliated, but only moderate exfoliation and enterocyte vacuolization was observed in KO piglets. In exp. II, delayed clinical symptoms appeared, yet the immunofluorescence staining/histopathologic inspection (I/H) scores of the two groups differed little. In exp. III, the animals exhibited clinical and pathological signs after inoculation similar to those in exp. II. These results suggest that porcine CMAH KO with nullified NGNA expression are not immune to PEDV but that this KO may lessen the severity of the infection and delay its occurrence.
Inclusion complex of β-cyclodextrin with coffee chlorogenic acid: new insights from a combined crystallographic and theoretical study
Authors: Aree Thammarat
Published: December 2018

This work reports the elusive structural evidence for the [4]pseudorotaxane of β-cyclodextrin (β-CD) with coffee chlorogenic acid (CGA), a conjugate of caffeic acid (CFA) and quinic acid (QNA). A single-crystal X-ray structure analysis of the inclusion complex β-cyclodextrin–chlorogenic acid–water (2/2/17), 2C42H70O35·2C16H18O9·17H2O, reveals that CGA threads through β-CD and assembles via O—H...O hydrogen bonds and parallel-displaced π–π interactions in the twofold symmetry-related dimer yielding a [4]pseudorotaxane, which is crystallographically observed for the first time in CD inclusion complexes. The encapsulation of the aromatic ring and C=C—C(=O)O chain in the β-CD dimeric cavity indicates that the CFA moiety plays a determinant role in complexation. This is in agreement with the DFT-derived relative thermodynamic stabilities of the trimodal β-CD–CGA inclusion complexes, that is, β-CD complexed with different CGA components: C=C—C(=O)O chain > cyclohexane ring > aromatic ring. The complexation stability is further enhanced in the dimeric β-CD–CGA complex, with the CFA moiety totally enclosed in the β-CD dimeric cavity.
Crystal structure of a second monoclinic polymorph of 3-methoxybenzoic acid with Z′ = 1
Authors: Chia Tze Shyang , Kwong Huey Chong , Wong Qin Ai , Quah Ching Kheng , Arafath Md. Azharul
Published: December 2018

A new polymorphic form of the title compound, C8H8O3, is described in the centrosymmetric monoclinic space group P21/c with Z′ = 1 as compared to the first polymorph, which crystallizes with two conformers (Z′ = 2) in the asymmetric unit in the same space group. In the crystal of the second polymorph, inversion dimers linked by O—H...O hydrogen bonds occur and these are linked into zigzag chains, propagating along the b-axis direction by C—H...O links. The crystal structure also features a weak π–π interaction, with a centroid-to-centroid distance of 3.8018 (6) Å. The second polymorph of the title compound is less stable than the reported first polymorph, as indicated by its smaller calculated lattice energy.
Analysis of BIM use for asset management in three public organizations in Québec, Canada
Authors: Brunet Maude , Motamedi Ali , Guénette Louis-Martin , Forgues Daniel
Published: December 2018

Purpose

Given the ongoing digital transformation, building information modeling (BIM) has great potential to create a collaborative environment in the whole lifecycle of the built asset, from inception to decommissioning. The paper aims to discuss this issue.

Design/methodology/approach

This paper relates current developments in Québec with regard to the use of BIM for asset management (AM). The steps taken by three public organizations to develop their capabilities and take advantage of new possibilities are presented. The main methodological approach is based on participant observation, through case studies complemented by a questionnaire.

Findings

This paper reports on results and analysis of an important module of a broader research project on the impact of new technologies and collaborative methods for projects and AM. The results of this first research module points to the importance of using pilot projects to develop a continuous improvement approach, where feedback loops from projects support the development of AM capabilities and culture. Another important finding is the importance of sharing experience for the three public organizations involved.

Originality/value

The main contributions of this paper are to document this overarching research program and to gain deeper insights by reflexively considering the steps taken and the ones ahead for the quest to enhance the transfer of information for built assets at the end of projects to the operations and maintenance phase and to use BIM for operation.
Enhancing business process execution with a context engine
Authors: Janiesch Christian , Kuhlenkamp Jörn
Published: December 2018

Purpose

Changes in workflow relevant data of business processes at run-time can hinder their completion or impact their profitability as they have been instantiated under different circumstances. The purpose of this paper is to propose a context engine to enhance a business process management (BPM) system’s context-awareness. The generic architecture provides the flexibility to configure processes during initialization as well as to adapt running instances at decision gates or during execution due to significant context change.

Design/methodology/approach

The paper discusses context-awareness as the conceptual background. The technological capabilities of business rules and complex event processing (CEP) are outlined in an architecture design. A reference process is proposed and discussed in an exemplary application.

Findings

The results provide an improvement over the current situation of static variable instantiation of business processes with local information. The proposed architecture extends the well-known combination of business rules and BPM systems with a context engine based on CEP.

Research limitations/implications

The resulting architecture for a BPM system using a context engine is generic in nature and, hence, requires to be contextualized for situated implementations. Implementation success is dependent on the availability of context information and process compensation options.

Practical implications

Practitioners receive advice on a reference architecture and technology choices for implementing systems, which can provide and monitor context information for business processes as well as intervene and adapt the execution.

Originality/value

Currently, there is no multi-purpose non-proprietary context engine based on CEP or any other technology available for BPM, which facilitates the adaptation of processes at run-time due to changes in context variables. This paper will stimulate a debate between research and practice on suitable design and technology.
Identification of barriers to PLM institutionalization in large manufacturing organizations
Authors: Singh Shikha , Misra Subhas Chandra
Published: December 2018

Purpose

The purpose of this paper is to study the barriers to institutionalize the product lifecycle management (PLM) in large manufacturing organizations. The paper explores the hurdles and identifies the causal barriers to support the organizations’ transformation into digitized firms.

Design/methodology/approach

The paper utilized the multi-criteria decision making technique, i.e., DEMATEL (DEcision MAking Trial and Evaluation Laboratory) method to find the causal barriers, and adopted maximum mean de-entropy (MMDE) algorithm to determine the threshold value based on the information entropy of the relations among the barriers to PLM institutionalization.

Findings

This study explored nine barriers to PLM institutionalization and empirically identified the four critical barriers among the nine.

Research limitations/implications

The present work is exploratory case-based research which is limited to a case of an Indian aircraft manufacturing firm with a limited number of respondents. More sophisticated statistical tools can be utilized to consider the subjectivity of the respondents. However, this research explores the various hurdles to PLM success and serves as a relevant outcome to identify the critical barriers to institutionalize the PLM concept.

Practical implications

The findings of the paper provide guidelines to the case company and similar firms for obtaining maximum benefits of PLM. The methodology shown in this paper will be useful to various large scale industries in identifying the critical barriers to PLM institutionalization among all existing barriers so that they can take appropriate measures before they proceed to adopt PLM.

Originality/value

The present work discusses the different reasons for which the companies are not able to derive the maximum benefits of PLM even after the implementation of PLM systems. This work uniquely applied the DEMATEL and MMDE methods to investigate the critical barriers to PLM institutionalization in an aircraft manufacturing firm.
The buffering effects of CSR reputation in times of product-harm crisis
Authors: Kim Yeonsoo , Woo Chang Wan
Published: December 2018

Purpose

The purpose of this paper is to examine the role of prior-CSR reputation in protecting a company’s CSR reputation during product-harm crises and how it influences consumers’ crisis-related behavioral intentions (i.e. supportive communication, resistance to negative information and crisis resiliency). The authors test whether the impact of prior-CSR reputation differs by crisis type as well.

Design/methodology/approach

A randomized 2 (CSR reputation: good vs bad) × 2 (product-harm crisis type: tampering vs preventable) full factorial design in two industry settings (food industry and retail industry) with consumer samples was conducted.

Findings

The results revealed the determinant role of positive prior-CSR reputation in protecting reputational assets. A company with positive CSR reputation experiences no decrease in its CSR reputation during victim crises and fairly minor decreases during preventable crises. However, a company with a bad prior-CSR reputation experiences a greater decline in its CSR reputation across both crises; the level of decline during victim crises was as substantial as the decline experienced during a preventable crisis. The prior-CSR reputation directly affects consumers’ crisis-related intentions, and indirectly does so through post-CSR reputation. As post-CSR reputation becomes more positive, consumers display greater resistance to negative information, supportive communication intent and crisis resiliency.

Originality/value

This study advances the understanding of the role of corporate reputation during crises and provides additional empirical evidence of how the buffering effect of CSR can extend beyond product-related intentions among consumers. The findings can induce companies to adopt CSR programs more systematically and proactively under a long-term strategic plan.
Uberization in Paris – the issue of trust between a digital platform and digital workers
Authors: Wentrup Robert , Nakamura H. Richard , Ström Patrik
Published: December 2018

Purpose

Using the lens of Uber’s digital workers in Paris, the purpose of this paper is to investigate how the trust-building mechanism is constructed between a digital platform and its digital workers in a foreign market entry.

Design/methodology/approach

This is a case study based on empirical data from in-depth interviews with 35 Uber drivers. A cross-disciplinary literature framework from mainly international business and internet geography theory and a reflexive qualitative methodology are applied.

Findings

Results show that the relationship between the digital platform and the digital workers is characterized by mistrust and suffers from decreasing commitment levels soon after market entry. Uber mitigates its mistrust via control and scarce mechanisms. The digital drivers’ “illusionary freedom”, a state in which they feel they can log on and log off at any time, enables the digital platform to gradually lower its commitment. The authors find that the mistrust does not seem to hamper the digital platform’s business performance.

Research limitations/implications

The paper mainly covers the digital workers’ perspective and the case of Uber’s market entry in Paris.

Social implications

This paper implies that digitally conveyed control seems to come at the cost of lowered human trust. Given the pace at which digital control systems are permeating society, this could eventually lower the whole societal trust level.

Originality/value

The authors criticize incumbent international business theory for not being sufficiently able to explain a contemporary digital business logic and the authors challenge the general assumption that successful internationalization is built through trust. The authors contribute with the conceptualization of a new technical market entry mode for digital platforms – “digitally controlled proxies”.
Awareness and use of self-archiving options among academic librarians in Nigerian universities
Authors: Okeji Clement Chukwuma , Eze Monica Eberechukwu , Chibueze Nneka Maureen
Published: December 2018

Purpose

The purpose of this study was to investigate the extent to which academic librarians in Nigerian universities use self-archiving options to make their research papers visible globally.

Design/methodology/approach

An online survey was designed using SurveyMonkey software to collect data from 394 academic librarians in Nigerian Universities.

Findings

The study revealed that the academic librarians in Nigerian universities know and actually use self-archiving options such as ResearchGate, institutional repository and Academia.edu to self-archive their publications. While other promotional tools such as kudos, Mendeley.com and personal websites/servers are not popularly used by the academic librarians. Increased exposure of previously published work, broadens the dissemination of academic research generally, and increases institutions’ visibility were among the factors the academic librarians indicated as very important that motivate them to contribute their scholarly output to self-archiving options.

Research limitations/implications

One major challenge to the study is that many academic librarians in Nigeria do not check their e-mails regularly to enable them to respond to a request to participate in an online survey; some of them do not have stable internet facilities, whereas others are reluctant to respond to an online questionnaire. These reasons led to a low response rate which makes it difficult to generalize findings.

Practical implications

Findings from the study will create awareness for academic librarians in developing countries to see the need to self-archive their pre-print and accepted version of their papers in different self-archiving platforms.

Originality/value

Self-archiving of papers by authors will lead to an increased visibility of the author and possible citation of the work and chances of collaboration with international colleagues for research projects.
Using fractional order weakening buffer operator to forecast the main indices of online shopping in China
Authors: Gao Xiao Hui , Wu Lifeng
Published: December 2018

Purpose

The purpose of this paper is to predict the main economic indices of online shopping in China.

Design/methodology/approach

A fractional order weakening buffer operator (WBO) for the GM(1,1) model is put forward in order to solve the problem of limited nonlinear data. The order number of WBO can adjust in line with the scenario.

Findings

The experimental results indicate that the proposed method can consider the scenario and obtain more accurate forecasting results.

Originality/value

This study found that the slowdown of growth trend after the previous high speed expansion period will continue, and the online shopping sellers should make more efforts to develop potential consumers to increase its turnover.
An Integrated Computerised Maintenance Management System (I-CMMS) for IBS building maintenance
Authors: Ismail Zul-Atfi
Published: December 2018

Purpose

The purpose of this paper is to focus on the development of an integrated computerised maintenance management system to improve the information storage of design and construction, diagnostic and defect risk assessments on IBS building through the integration of building information modelling (BIM).

Design/methodology/approach

The methodology used interviews with the IBS building client/maintenance contractor in Malaysia to gather information about maintenance management problems, approaches to address problems, information and communication technology implementation and use of emerging technologies, in addition to prototyping a system development life cycle for system development.

Findings

Relevant process flowchart documents of system development were obtained from the case study and reviewed to assist in providing an automation technique for decision-making and structural defect diagnostic operation through the integration of Visual Basic.Net, MS Access and Autodesk Revit software.

Originality/value

This research focuses on automatic bidirectional communications between an Expert System and BIM on a database level. Adoption of the approaches suggested in the research will enable the system to promote the development of zero IBS building maintenance.
Historical buildings’ energy conservation potentialities
Authors: Spigliantini Giorgia , Fabi Valentina , Schweiker Marcel , Corgnati Stefano
Published: December 2018

Purpose

Today, about 30 per cent of European existing buildings can be entitled as “historical buildings”. Nowadays, their energy retrofit is important to reach the ambitious European CO2 emissions’ reduction objectives. The purpose of this paper is to outline a methodology to investigate the potential energy savings and the enhancement of historical buildings’ liveability by acting only on their operation, so that the building fabric could be maintained as much as possible as the original evidence.

Design/methodology/approach

The paper describes the framework’s theoretical phases and their application in two real case studies. The methodology was conceived with a pre-test and post-test design approach.

Findings

The research demonstrated that the elaborated methodology is flexible and allows the adoption of different energy retrofit strategies for the different cases.

Research limitations/implications

Limitations arise out of the circumstance that the methodology is based on occupants and technicians willingness to engage in the strategies, so it is not possible to quantify its efficacy ex ante.

Practical implications

Practical implications can be found in the way of addressing energy retrofit strategies through a user-centric approach with minimum impact on the building itself.

Social implications

At the same time, the methodology has a strong social aspect with its potential to change people’s attitudes towards energy usage and behaviour.

Originality/value

This study not only represents the first attempt of applying a systematic energy retrofit strategy based on occupants and technicians behavioural change in historic buildings, but also is one of the first studies dedicated to occupants’ comfort and behaviour assessment in this context.
Challenges facing the implementation of the national natural gas policy in Tanzania
Authors: Bishoge Obadia Kyetuza , Zhang Lingling , Mushi Witness Gerald
Published: December 2018

Purpose

This study aims to investigate the challenges facing the implementation of the natural gas policy in Tanzania.

Design/methodology/approach

A structured questionnaire was used to collect data, while the principal component analysis and statistical tests were used to explore the relationship between the opinions on the influential factors for the natural gas policy implementation and the demographic information.

Findings

The findings showed that over 50 per cent of the respondents regarded poor community participation and transparency and accountability as the major policy implementation challenges. Most of the demographic information showed the statistically significant effects of the policy implementation influential factors.

Originality/value

This paper provides the current challenges facing the implementation of the national natural gas policy in Tanzania.