bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective sweeps in a nutshell; the genomic footprint of rapid insecticide resistance evolution in an insect
Authors: Calla Bernarda , Demkovich Mark , Siegel Joel P. , Viana João Paulo Gomes , Walden Kim K.O. , Robertson Hugh M. , Berenbaum May R.
Published: November 2019

Relatively few genome-wide population studies of field-acquired insecticide resistance have been carried out on agricultural pests. Recently acquired bifenthrin resistance in a population of the navel orangeworm (Amyelois transitella), the main insect pest of almond orchards in California, provided an opportunity to examine the short- and long-term effects of heavy insecticide usage in the population genomic landscape of this species. We re-sequenced the genomes of three contemporaryA. transitellanatural populations differing in bifenthrin resistance status and characterized their population genetics parameters, in the process we detected an exceptionally large selective sweep in all populations. This sweep has virtually no polymorphisms and extends up to 1.3 Mb (spanning 43 genes) in the resistant population. We analyzed the possible causes of this unusually strong population genetic signature, and found genes in the sweep that are associated with DDT and pyrethroid resistance including a cluster of cytochrome P450 coding genes and the gene coding for the small conductance sodium channel “para”. Moreover, we found that the sequence along the sweep is nearly identical in the genome assembled from a strain founded in 1966, suggesting that the underpinning for insecticide resistance may have been laid a half-century ago when the California Central Valley experienced massive area-wide applications of DDT for pest control. Our findings are consistent with a scenario whereby insecticide resistance in this species evolved as a stacking of selective pressures that started decades ago and that effectively reduced variation in a region of the genome containing several genes associated with resistance to insecticides with a shared target site and mechanism of action.
Not so automatic: Task relevance and perceptual load modulate cross-modal semantic congruence effects on spatial orienting
Authors: Kvasova Daria , Soto-Faraco Salvador
Published: November 2019

Recent studies show that cross-modal semantic congruence plays a role in spatial attention orienting and visual search. However, the extent to which these cross-modal semantic relationships attract attention automatically is still unclear. At present the outcomes of different studies have been inconsistent. Variations in task-relevance of the cross-modal stimuli (from explicitly needed, to completely irrelevant) and the amount of perceptual load may account for the mixed results of previous experiments. In the present study, we addressed the effects of audio-visual semantic congruence on visuo-spatial attention across variations in task relevance and perceptual load. We used visual search amongst images of common objects paired with characteristic object sounds (e.g., guitar image and chord sound). We found that audio-visual semantic congruence speeded visual search times when the cross-modal objects are task relevant, or when they are irrelevant but presented under low perceptual load. Instead, when perceptual load is high, sounds fail to attract attention towards the congruent visual images. These results lead us to conclude that object-based crossmodal congruence does not attract attention automatically and requires some top-down processing.
Mutations in Auxilin cause parkinsonism via impaired clathrin-mediated trafficking at the Golgi apparatus and synapse
Authors: Roosen Dorien A. , Landeck Natalie , Bonet-Ponce Luis , Kluss Jillian , Conti Melissa , Smith Nathan , Saez-Atienzar Sara , Ding Jinhui , Beilina Aleksandra , Kumaran Ravindran , Kaganovich Alice , du Hoffmann Johann , Williamson Chad D. , Gershlick David C. , Sampieri Luciana , Bleck Christopher K. E. , Liu Chengyu , Bonifacino Juan S. , Li Yan , Lewis Patrick A. , Cookson Mark R.
Published: November 2019

Parkinson’s disease (PD) is a common neurodegenerative motor disorder characterized in part by neuropathological lesions in the nigrostriatal pathway. Loss of function mutations in Auxilin, the major neuronal clathrin uncoating protein, cause an aggressive form of juvenile onset PD. How mutations in Auxilin cause PD, is currently not understood. Here, we generated a novel mouse model carrying an endogenous pathogenic Auxilin mutation that phenocopies neurological features observed in patients, including motor impairments and seizures. Unbiased mapping of the Auxilin interactome identified synaptic and Golgi-resident clathrin adaptor proteins as novel interactors. Impaired clathrin-mediated trafficking in mutant Auxilin mice, both at the Golgi and the synapse, results in neuropathological lesions in the nigrostriatal pathway. Collectively, these results provide molecular mechanisms of PD pathogenesis in Auxilin mutation carriers, reinforcing a key role for clathrin-mediated trafficking in PD, and expand our understanding of the cellular function of Auxilin.
Cellular chaining influences biofilm formation and structure in Group A Streptococcus
Authors: Matysik Artur , Ho Foo Kiong , Tan Alicia Qian Ler , Vajjala Anuradha , Kline Kimberly A.
Published: November 2019

Group A Streptococcal (GAS) biofilm formation is an important pathological feature contributing to the antibiotic tolerance and progression of various GAS infections. Although a number of bacterial factors have been described to promote in vitro GAS biofilm formation, the relevance of in vitro biofilms to host-associated biofilms requires further understanding. In this study, we demonstrate how constituents of the host environment, such as lysozyme and NaCl, can modulate GAS bacterial chain length and, in turn, shape GAS biofilm morphology and structure. Disruption of GAS chains with lysozyme results in biofilms that are more stable. Based on confocal microscopy, we attribute the increase in biofilm stability to a dense and compact three-dimensional structure produced by de-chained cells. To show that changes in biofilm stability and structure are due to the shortening of bacterial chains and not specific to the activity of lysozyme, we demonstrate that augmented chaining induced by NaCl or deletion of the autolysin gene mur1.2 produced defects in biofilm formation characterized by a loose biofilm architecture. We conclude that GAS biofilm formation can be directly influenced by host and environmental factors through the modulation of bacterial chain lengths, potentially contributing to persistence and colonization within the host. Further studies of in vitro biofilm models incorporating physiological constituents such as lysozyme may uncover new insights into the physiology of in vivo GAS biofilms.
Primed acquisition and microhomology-mediated end-joining cooperate to confer specific CRISPR immunity against invasive genetic elements
Authors: Wang Xiaojie , Wu Bo , Zhang Zhufeng , Liu Tao , Li Yingjun , Hu Guoquan , He Mingxiong , Peng Nan
Published: November 2019

CRISPR-Cas systems provide archaea and bacteria with adaptive immunity against invasive genetic elements through acquisition of invader-derived spacers. De novo spacer acquisition generally adapts spacers from both invaders and hosts with a bias towards invaders, while primed acquisition shows higher specificity to adapt spacers from invaders. Here, in Zymomonas mobilis subtype I-F system, primed acquisition showed much higher efficiency than de novo acquisition in this system. However, both routes recognised a large proportion of protospacers with the less conserved 5’-end CC PAM. Moreover, primed acquisition showed a preference towards protospacers located at the opposite strand and 3’ direction of the priming protospacer sites, differing from the canonical subtype I-F system. Further, self-spacers were adapted at a higher frequency during de novo spacer acquisition, probably leading to self-interference. Importantly, this species employed microhomology-mediated end-joining (MMEJ) for repair of host DNA breaks guided by self-targeted spacers, and overexpression of a host NAD+-dependent Ligase-A significantly increased the repair efficiency. In summary, our findings demonstrate that Z. mobilis uses primed acquisition for higher specific uptake of invader DNA and employs MMEJ to repair host DNA breaks guided by self-targeted spacers, showing specific immunity against invasive genetic elements.
RNA recognition by the E2 subunit of the chloroplast pyruvate dehydrogenase complex from Chlamydomonas
Authors: Neusius Daniel , Kleinknecht Laura , Bohne Alexandra-Viola , Nickelsen Jörg
Published: November 2019

The dihydrolipoamide acetyltransferase subunit (DLA2) of the chloroplast puruvate dehydrogenase complex (cpPDC) from the green alga Chlamydomonas reinhardtii has previously been shown to possess a moonlighting activity in chloroplast gene expression. Exclusively under mixotrophic growth conditions, DLA2 forms part of an RNP particle with the psbA mRNA that encodes the D1 protein of the photosystem II reaction center. Here, we report on the further characterization of DLA2’s RNA-binding activity. Size-exclusion chromatography and Western analyses revealed that DLA2 is the only cpPDC subunit that shuttles between the metabolic cpPDC and the RNP complex. Microscale thermophoresis-based determination of RNA-binding affinities demonstrated that two DLA2 regions are crucial for RNA recognition, the peripheral E3-binding domain (E3BD) and the C-terminus of the catalytic domain. Specificity for the psbA RNA probe is conferred by the E3BD in vitro, as verified by competitive binding assays in the presence of an excess of the E3 (DLD2) of cpPDC. The data support a model in which an environmental trigger induces release of DLA2 from the cpPDC and its subsequent association with the psbA mRNA.
Molecular Docking of Glycyrrhiza glabra against the Conserved Target M1, NA and NS1 Proteins of Influenza A Viral Strains Identified through Pangenome Analysis
Authors: Aishwarya S , Shantha Evangeline , Nantha Devi E , Sagaya Jansi R
Published: November 2019

Influenza viruses that infect humans are known to swiftly evolve over time. Influenza A virus has a negative single-stranded RNA genome in eight segments. Pangenome analysis of twelve strains of Influenza A viruses H1N1, H1N2, H2N2, H3N2, H5N1, H5N6, H7N2, H7N3, H7N7, H7N9, H9N2, and H10N8 gave insight on the core genes that are conserved and accessory genes that are specific for the strains. The proteins Neuraminidase, Matrix M1 and Nonstructural protein 1 were encoded by the core genes of segments 6, 7, and 8 respectively which proves that they are conserved in almost all the strains of influenza. The 3Dimensional structures of the core genes were interpreted by homology modeling and compared with corresponding Protein Data Bank structures (4MWQ, IEA3, 2GX9). Among several anti-viral phytocompounds that were virtually screened against the modeled and PDB target proteins, three molecules of Indian plant Glycyrrhiza glabra had high scores and interactions. Compounds 2,4,4’ Trihydrochalcone, Davidigenin and Licoflavone B docked well with the Neuraminidase, Matrix protein M1 and Nonstructural Protein NS1 respectively with good scores, minimized energy and interacted with the active sites. The compounds obeyed Lipinski’s Rule of five and exhibited drugability as well. Thus the present study focused on the drugable lead compounds from glabra that has inhibitory activities against the viral attachment, replication and matrix structure.
Harnessing Digital Health to Objectively Assess Cognitive Impairment in People undergoing Hemodialysis Process: The Impact of Cognitive Impairment on Mobility Performance Measured by Wearables
Authors: Zhou He , Al-Ali Fadwa , Wang Changhong , Hamad Abdullah , Ibrahim Rania , Talal Talal , Najafi Bijan
Published: November 2019

Background

Cognitive impairment is prevalent but still poorly diagnosed in hemodialysis adults, mainly because of the impracticality of current tools. This study examined whether remotely monitoring mobility performance can help identifying digital measures of cognitive impairment in hemodialysis patients.

Methods

Sixty-nine hemodialysis patients (age=64.1±8.1years, body mass index=31.7±7.6kg/m2) were recruited. According to the Mini-Mental State Exam, 44 (64%) were determined as cognitive-intact, and 25 (36%) as cognitive-impaired. Mobility performance, including cumulated posture duration (sitting, lying, standing, and walking), daily walking performance (step and unbroken walking bout), as well as postural-transition (daily number and average duration), were measured using a validated pendant-sensor for a continuous period of 24-hour during a non-dialysis day. Motor capacity was quantified by assessing standing balance and gait performance under single-task and dual-task conditions.

Results

No between-group difference was observed for the motor capacity. However, the mobility performance was different between groups. The cognitive-impaired group spent significantly higher percentage of time in sitting and lying (Cohens effect size d=0.78, p=0.005) but took significantly less daily steps (d=0.69, p=0.015) than the cognitive-intact group. The largest effect of reduction in number of postural-transition was observed in walk-to-sit transition (d=0.65, p=0.020). Regression models based on demographics, addition of daily walking performance, and addition of other mobility performance metrics, led to area-under-curves of 0.76, 0.78, and 0.93, respectively, for discriminating cognitive-impaired cases.

Conclusions

This study suggests that mobility performance metrics could be served as potential digital biomarkers of cognitive impairment among HD patients. It also highlights the additional value of measuring cumulated posture duration and postural-transition to improve the detection of cognitive impairment. Future studies need to examine potential benefits of mobility performance metrics for early diagnosis of cognitive impairment/dementia and timely intervention.
Space use and resource selection of bobcats in the Appalachian Mountains of western Virginia
Authors: McNitt David C. , Alonso Robert S. , Cherry Michael J. , Fies Michael L. , Kelly Marcella J.
Published: November 2019

Bobcats are an apex predator and a species of socio-cultural importance in the central Appalachian Mountains. Despite their importance, knowledge of bobcat spatial ecology in the region is sparse. We examined space use and resource selection of bobcats in the Appalachian Mountains of western Virginia during 3 biological seasons: breeding (January-March), kitten-rearing (April-September), and dispersal (October-December). We observed sex effects on all space use metrics, with male seasonal areas of use (SAU) approximately 3 times larger than female SAUs and male movement rates 1.5 times higher than females during all seasons. We found no seasonal effect on SAU size for either sex. Female movement rates increased during the kitten-rearing season, and male movement rates increased during the dispersal season. We examined seasonal bobcat resource selection at 2 hierarchical scales, selection of home ranges within the landscape (2ndorder) and selection of locations within home ranges (3rdorder). Female bobcats exhibited 2ndorder selection for higher elevations and deciduous forest and avoidance of fields. Males exhibited 2ndorder selection for higher elevations and fields. Male 2ndorder selection appears to be driven largely by the spatial distribution of females, which is mediated through the valley and ridge topography of the study area. Sample size precluded 3rdorder analysis for females, however males exhibited 3rdorder selection for higher elevations, fields, and deciduous forest. Resource selection patterns varied seasonally for both sexes, possibly driven by seasonal shifts in prey availability. Our findings highlight the importance of forested ridges to bobcats in the region. Our findings also illustrate the differences in space use between sexes, which future research efforts should consider. Further research should investigate seasonal shifts in bobcat prey selection, which may further explain the seasonal resource selection shifts we observed, and highlight potential implications for prey species.
Using software Vortex as a tool towards conservation actions for sharks
Authors: Barcellos Laís Ramos , Escarlate-Tavares Fabricio
Published: November 2019

Elasmobranchs, especially sharks, are part of the most threatened group of animals in the world. Among the factors that negatively affect these populations, the environmental degradation and disordered fishing can be highlighted. Although these threats are well known, the responses of most species to these factors are not fully understood, which makes it difficult to predict potential population responses according to conservation actions. The present study aims to develop a theoretical model based on a real population of white sharks (Carcharodon carcharias) that inhabit Gulf of Mexico, using their biological patterns to identify trends for the populations using Vortex (version 10.0.0.3) as a tool. The construction of the model was based on bibliographic data, considering parameters of life history, demographic rates and main known threats. Data were entered into Vortex software, and two population sizes were tested in the population viability analysis, indicating in both cases that the species tends to lose its genetic diversity over 500 years with a 12% and 51% of probability of extinction, respectively, considering exclusively its biological potential. This results can reflect on an mislead assumption of the real subpopulation’s size, which shows that the species is inserted into the vortex of extinction even with the existence of protective measures regarding white sharks on the location of the study, and it must incorporate neonates and juveniles individuals on the analysis to generate a consistent result. Despite this, the study suggests that the utilization of Vortex is capable of generating responses necessary for the conservation of sharks by analyzing stochastic events and life history in a simple way.
Epigenetic bases of grafting-induced vigour in eggplant
Authors: Cerruti Elisa , Gisbert Carmina , Drost Hajk-Georg , Valentino Danila , Portis Ezio , Barchi Lorenzo , Prohens Jaime , Lanteri Sergio , Comino Cinzia , Catoni Marco
Published: November 2019

In horticulture, grafting is a popular technique used to combine positive traits from two different plants. This is achieved by joining the plant top part (scion) onto a rootstock which contains the stem and roots. Despite its wide use, the biological mechanisms driving rootstock-induced alterations of the scion phenotype remain largely unknown. Given that epigenetics plays a crucial role during distance signalling in plants, we studied the genome-wide changes induced by DNA methylation in eggplant (Solanum melongena) plants grafted onto two interspecific rootstocks used to increase scion vigour. As a control, we compared any epigenetic effect found in such grafts to patterns detected in self-grafted plants. We found that vigour was associated with a specific change in scion gene expression and a genome-wide hypomethylation in CHH context. Interestingly, this hypomethylation correlated with the down-regulation of younger and potentially more active LTR retrotransposons (LTR-TEs), suggesting that graft-induced epigenetic modifications are associated to both physiological and molecular phenotypes in grafted plants. We propose that rootstocks can promote vigour by reducing DNA methylation in the scion genome, following similar principles found in some heterotic hybrids.
Vacuolar processing enzyme translocates to the vacuole through the autophagy pathway to induce programmed cell death
Authors: Teper-Bamnolker Paula , Danieli Raz , Peled-Zehavi Hadas , Belausov Eduard , Abu-Abied Mohamad , Avin-Wittenberg Tamar , Sadot Einat , Eshel Dani
Published: November 2019

The caspase-like vacuolar processing enzyme (VPE) is a key factor in programmed cell death (PCD) associated with plant stress responses. Growth medium lacking a carbon source and dark conditions caused punctate labeling of 35S::VPE1-GFP (StVPE1-GFP) in potato leaves. Carbon starvation of BY-2 cells induced higher VPE activity and PCD symptoms. Growing VPE-RNAi BY-2 cells without sucrose reduced VPE activity and prevented PCD symptoms. During extended exposure to carbon starvation, VPE expression and activity levels peaked, with a gradual increase in BY-2 cell death. Histological analysis of StVPE1-GFP in BY-2 cells showed that carbon starvation induces its translocation from the endoplasmic reticulum to the central vacuole, through tonoplast engulfment. Exposure of BY-2 culture to the autophagy inhibitor concanamycin A caused autophagic bodies accumulation in the cell vacuole. Such accumulation did not occur in the presence of 3-methyladenine, an inhibitor of early-stage autophagy. BY-2 cells constitutively expressing StATG8IL-RFP, an autophagosome marker, showed colocalization with the StVPE1-GFP protein in the cytoplasm and vacuole. RNAi silencing of the core autophagy component ATG4 in BY-2 cells reduced VPE activity and cell death. These results are the first to suggest that VPE translocates to the cell vacuole through the autophagy pathway, leading to PCD.

One sentence summary

Carbon starvation induced programmed cell death by trafficking vacuolar processing enzyme through the autophagy pathway to the vacuole.
Stochastic model for the CheY-P molarity in the neighbourhood ofE. coliflagella motors
Authors: Fier G. , Hansmann D. , Buceta R. C.
Published: November 2019

Escherichia coliserves as prototype for the study of peritrichous enteric bacteria that perform runs and tumbles alternately. Bacteria run forward as a result of the counterclockwise (CCW) rotation of their flagella bundle, which is located rearward, and perform tumbles when at least one of their flagella rotates clockwise (CW), moving away from the bundle. The flagella are hooked to molecular rotary motors of nanometric diameter able to make transitions between CCW and CW rotations that last up to one hundredth of a second. At the same time, flagella move or rotate the bacteria’s body microscopically during lapses that range between a tenth and ten seconds. We assume that the transitions between CCW and CW rotations occur solely by fluctuations of CheY-P molarity in the presence of two threshold values, and that a veto rule selects the run or tumble motions. We present Langevin equations for the CheY-P molarity in the vicinity of each molecular motor. This model allows to obtain the run- or tumble-time distribution as a linear combination of decreasing exponentials that is a function of the steady molarity of CheY-P in the neighbourhood of the molecular motor, which fits experimental data. In turn, if the internal signaling system is unstimulated, we show that the runtime distributions reach power-law behaviour, a characteristic of self-organized systems, in some time range and, afterwards, exponential cutoff. In addition, our model explains without any fitting parameters the ultrasensitivity of the flagella motors as a function of the steady state of CheY-P molarity. In addition, we show that the tumble bias for peritrichous bacterium has a similar sigmoid-shape to the CW bias, although shifted to lower concentrations when the flagella number increases. Thus, the increment in the flagella number allows lower operational values for each motor increasing amplification and robustness of the chemotatic signaling pathway.
Clonal reconstruction from time course genomic sequencing data
Authors: Ismail Wazim Mohammed , Tang Haixu
Published: November 2019

Background

Bacterial cells during many replication cycles accumulate spontaneous mutations, which result in the birth of novel clones. As a result of this clonal expansion, an evolving bacterial population has different clonal composition over time, as revealed in the long-term evolution experiments (LTEEs). Accurately inferring the haplotypes of novel clones as well as the clonal frequencies and the clonal evolutionary history in a bacterial population is useful for the characterization of the evolutionary pressure on multiple correlated mutations instead of that on individual mutations.

Results

In this paper, we study the computational problem of reconstructing the haplotypes of bacterial clones from the variant allele frequencies observed from an evolving bacterial population at multiple time points. We formalize the problem using a maximum likelihood function, which is defined under the assumption that mutations occur spontaneously, and thus the likelihood of a mutation occurring in a specific clone is proportional to the frequency of the clone in the population when the mutation occurs. We develop a series of heuristic algorithms to address the maximum likelihood inference, and show through simulation experiments that the algorithms are fast and achieve near optimal accuracy that is practically plausible under the maximum likelihood framework. We also validate our method using experimental data obtained from a recent study on long-term evolution of Escherichia coli.

Conclusion

We developed efficient algorithms to reconstruct the clonal evolution history from time course genomic sequencing data. Our algorithm can also incorporate clonal sequencing data to improve the reconstruction results when they are available. Based on the evaluation on both simulated and experimental sequencing data, our algorithms can achieve satisfactory results on the genome sequencing data from long-term evolution experiments.

Availability

The program (ClonalTREE) is available as open-source software on GitHub at https://github.com/COL-IU/ClonalTREE
Alfalfa leaf curl virus is transmitted by Aphis craccivora in a highly specific circulative manner
Authors: Ryckebusch F. , Sauvion N. , Granier M. , Roumagnac P. , Peterschmitt M.
Published: November 2019

Two members of the genus Capulavirus (Geminiviridae) are transmitted by aphids including Alfalfa leaf curl virus (ALCV) transmitted by Aphis craccivora. The capulavirus Euphorbia caput-medusae latent virus was shown here to be transmitted also by A. craccivora, using the population EuphorbiaSA. ALCV was transmissible by several A. craccivora populations including Robinia, but not EuphorbiaSA, reflecting a high transmission specificity. ALCV accumulation and localization were analyzed in whole insects, midguts, hemolymphs, and heads of aphids from both populations and from the non-vector species Acyrthosiphon pisum. A 6-day persistence was observed in A. craccivora populations but not in A. pisum. Vector and non-vector A. craccivora populations could be distinguished by contrasted virus accumulations and midgut intracellular localization. Results confirm that ALCV is transmitted according to a circulative-persistent mode, and are consistent with a gut barrier to the transmission of ALCV in A. pisum and a primary salivary gland barrier in A. craccivora.
Transcriptional reprogramming in fused cells is triggered by plasma-membrane diminution
Authors: Feliciano Daniel , Espinosa-Medina Isabel , Weigel Aubrey , Milano Kristin M. , Tang Zhonghua , Lee Tzumin , Kliman Harvey J. , Guller Seth M. , Ott Carolyn M. , Lippincott-Schwartz Jennifer
Published: November 2019

Developing cells divide and differentiate, and in many tissues, such as bone, muscle, and placenta, cells fuse acquiring specialized functions. While it is known that fused-cells are differentiated, it is unclear what mechanisms trigger the programmatic-change, and whether cell-fusion alone drives differentiation. To address this, we employed a fusogen-mediated cell-fusion system involving undifferentiated cells in tissue culture. RNA-seq analysis revealed cell-fusion initiates a dramatic transcriptional change towards differentiation. Dissecting the mechanisms causing this reprogramming, we observed that after cell-fusion plasma-membrane surface area decreases through increased endocytosis. Consequently, glucose-transporters are internalized, and cytoplasmic-glucose and ATP transiently decrease. This low-energetic state activates AMPK, which inhibits YAP1, causing cell-cycle arrest. Impairing either endocytosis or AMPK prevents YAP1 inhibition and cell-cycle arrest after fusion. Together these data suggest that cell-fusion-induced differentiation does not need to rely on extrinsic-cues; rather the plasma-membrane diminishment forced by the geometric-transformations of cell-fusion cause transient cell-starvation that induces differentiation.
Combination antibiotic PMMA composites provide sustained broad-spectrum antimicrobial activity and allow for post-implantation refilling
Authors: Cyphert Erika L. , Lu Chao-yi , Marques Dylan W. , Learn Greg D. , von Recum Horst A.
Published: November 2019

Antibiotics are commonly added to poly(methyl methacrylate) (PMMA) by surgeons to locally treat infections such as in bone cement for joint replacement surgeries, but also as implantable antimicrobial “beads”. However, this strategy is of limited value in high risk patients where infections can be recurrent or chronic and otherwise hard to treat. Also when only one drug is incorporated and applied toward poly-microbial infections (multiple bacterial species), there is a high risk that bacteria can develop antibiotic resistance. To combat these limitations, we developed a combination-antibiotic PMMA composite system comprised of rifampicin-filled β-cyclodextrin (β-CD) microparticles added into PMMA filled with a second drug. Different formulations were evaluated through Zone-of-Inhibition, drug activity, antibiotic release and re-filling, as well as mechanical studies. Our combination-antibiotic PMMA composite system achieved up to an eight-fold increase in duration of antimicrobial activity in comparison to clinically used antibiotic-filled PMMA. Inclusion of CD microparticles also allowed for refilling of additional antibiotics after simulated implantation, resulting in additional windows of therapeutic efficacy. Mechanical testing showed that our tested formulations did have a small, but significant decrease in mechanical properties when compared to unmodified controls. While further studies are needed to determine whether the tested formulations are still suitable for load-bearing applications (e.g. bone cement), our composites are certainly amenable for a variety of non-load bearing applications (e.g. antimicrobial “beads” and temporary spacer in two-stage arthroscopic revisions).
Grey clustering model based on kernel and information field
Authors: Luo Dang , Huihui Zhang
Published: November 2019

Purpose

The purpose of this paper is to propose a grey clustering model based on kernel and information field to deal with the situation in which both the observation values and the turning points of the whitenization weight function are interval grey numbers.

Design/methodology/approach

First, the “unreduced axiom of degree of greyness” was expanded to obtain the inference of “information field not-reducing”. Then, based on the theoretical basis of inference, the expression of whitenization weight function with interval grey number was provided. The grey clustering model and fuzzy clustering model were compared to analyse the relationship and difference between the two models. Finally, the paper model and the fuzzy clustering model were applied to the example analysis, and the interval grey number clustering model was established to analyse the influencing factors of regional drought disaster risk in Henan Province.

Findings

The example analysis results illustrate that although the two clustering methods have different theoretical basis, they are suitable for dealing with complex systems with uncertainty or grey characteristic, solving the problem of incomplete system information, which has certain feasibility and rationality. The clustering results of case study show that five influencing factors of regional drought disaster risk in Henan Province are divided into three classes, consistent with the actual situation, and they show the validity and practicability of the clustering model.

Originality/value

The paper proposes a new whitenization weight function with interval grey number that can transform interval grey number operations into real number operations. It not only simplifies the calculation steps, but it has a great significance for the “small data sets and poor information” grey system and has a universal applicability.
Could gamification improve visitors’ engagement?
Authors: la Cuadra Miguel Trigo-De , Vila-Lopez Natalia , Hernandez-Fernández Asunción
Published: November 2019

Purpose

The experiences are the basis of the tourist sector and the creation of unique and unforgettable ones allows the differentiation from the competition. The purpose of this paper is to analyze the effects of the experience when visiting a zoo on our emotions and how they influence our (positive and/or negative) behaviors and to investigate whether an innovation (gamification programs) could be used to intensify the relations proposed.

Design/methodology/approach

The authors collected the experiences lived by 242 visitors in BIOPARC Valencia (a zoological park). Two subsamples were identified: 166 insatiable tourists who expressed that the gamification would complete their experience, and 76 conventional tourists who indicated that the current experience did not need any kind of improvement.

Findings

The results show that some of the proposed relationships are more tenuous among the insatiable visitors, defenders of gamification, which allows the authors to verify the possibilities offered by gamification.

Originality/value

First, although the impact of experiential modules on emotions and behaviors has already been investigated, as far as behavioral effects are concerned, the difference between positive behaviors (loyalty) and negative behaviors (complaints and claims) has not been addressed. Second, the relationship between both types of behaviors (positive and negative) in this sector has not been studied to date. Finally, although the literature recognizes the impact of technology and its importance as an instrument of experiential marketing, its empirical exploration remains uninvestigated. Indeed, to date, the willingness of consumers to adopt gamified strategies to improve their tourism experiences has not been investigated.
Dynamic behavior analysis of a rigid rotor supported by hydrostatic squeeze film dampers compensated with new electrorheological valve restrictors
Authors: Benadda Mohamed , Bouzidane Ahmed , Thomas Marc , Guilbault Raynald
Published: November 2019

Purpose

This paper aims to propose a new hydrostatic squeeze film damper compensated with electrorheological valve restrictors to control the nonlinear dynamic behavior of a rigid rotor caused by high unbalance eccentricity ratio. To investigate the effect of electrorheological valve restrictors on the dynamic behavior of a rigid rotor, a nonlinear model is developed and presented.

Design/methodology/approach

The nonlinear results are compared with those obtained from a linear approach. The results show good agreement between the linear and nonlinear methods when the unbalanced force is small. The effects of unbalance eccentricity ratio and electric field on the vibration response and the bearing transmitted force are investigated using the nonlinear models.

Findings

The results of simulation performed that the harmonics generated by high unbalance eccentricities can be reduced by using hydrostatic squeeze film damper compensated with electrorheological valve restrictors.

Originality/value

The numerical results demonstrate that this type of smart hydrostatic squeeze film damper provides to hydrostatic designers a new bearing configuration suitable to control rotor vibrations and bearing transmitted forces, especially for high speed.
Understanding and implementing CRM initiatives in international markets
Authors: Roggeveen Anne L. , Beitelspacher Lauren
Published: November 2019

Purpose

Drawing from prior research, the purpose of this paper is to outline the benefits of cause-related marketing (CRM) campaigns for the sponsoring multinational organization and the non-profit, to examine the impact of firm–cause fit and how this fit forms and to describe consumer reactions to CRM campaigns. With this backdrop, the paper offers recommendations for how multinational corporations (MNCs) should undertake international CRM activities.

Design/methodology/approach

A comprehensive literature review, undertaken with a theoretical lens, helps reveal how CRM campaigns can be executed in international markets.

Findings

With accurate country market assessments, MNCs are better prepared to integrate with the local environment and deliver effective CRM strategies and value.

Practical implications

This paper offers guidance for MNCs that are interested in expanding internationally in terms of how to develop an effective CRM in international markets. In addition, it explores relationship elements that are critical for creating a successful, synergistic relationship between the firm and the non-profit.

Originality/value

When adopted effectively, CRM can be a valuable tool for firms as they expand internationally, by establishing relationships with local customers. This research suggests guidelines for multinationals to consider as they expand their presence globally and apply CRM in broader contexts.
Conventional banks and Fintechs: how digitization has transformed both models
Authors: Paulet Elisabeth , Mavoori Hareesh
Published: November 2019

Purpose

The digital revolution has substantially changed the business environment. Most banks have acknowledged the importance of new technologies to improve performance and client satisfaction. The development of these innovations has led to the entrance of the so-called Fintechs. This paper aims to evaluate the impact of these transformations on the performance of financial institutions and on their business model.

Design/methodology/approach

The authors use data envelopment analysis and Malmquist total productivity indices to measure financial institutions’ efficiency and their influence on strategy.

Findings

The main finding is that clients are more than ever at the core of banking strategy. The irrelevance of distance in basic banking transactions has reduced expenses and contributed to increasing revenues for all financial institutions. Banks will have a card to play in the advice they can bring to their clients.

Practical implications

This research could be of interest for financial managers who wish to re-examine their current business practices and imagine their business model for the future.

Originality/value

The contribution will be to further define the correlation between the provision of electronic banking services and its performance by including diversified institutions (conventional banks, Fintechs, Gafas) in the sample from multiple geographic zones to identify differences as regards their efficiency and business practices.
Stock market activity and Google Trends: the case of a developing economy
Authors: Bui Vinh Xuan , Nguyen Hang Thu
Published: November 2019

Purpose

The purpose of this paper is to investigate the impacts of investor attention on stock market activity.

Design/methodology/approach

The authors employed the Google Search Volume (GSV) Index, a direct and non-traditional proxy for investor attention.

Findings

The results indicate a strong correlation between GSV and trading volume – a traditional measure of attention – proving the new measure’s reliability. In addition, market-wide attention increases both stock illiquidity and volatility, whereas company-level attention shows mixed results, driving illiquidity and volatility in both directions.

Originality/value

To the best of the authors’ knowledge, Nguyen and Pham’s (2018) study has been the only previous study identifying investor attention in Vietnam by using GSV as a proxy and examining the impacts of broad search terms about the macroeconomy on the stock market as a whole – on stock indices’ movements. The paper will contribute to this by quantifying GSV impacts on each stock individually.
Effects of government policy, quality of human resources and professional institutions on workforce competitiveness using welding technology as mediating variable
Authors: Agusman Aris Afandi , Maupa Haris , Muis Mahlia , Idrus Tabba Muhammad
Published: November 2019

Purpose

This paper aims to examine and analyze the effects of government policy, quality of human resources and professional institutions on workforce competitiveness using welding technology variable as a mediating variable.

Design/methodology/approach

This study used quantitative research by using partial least square – structural equation modeling (PLS-SEM) to analyze the collected data.

Findings

Based on the results of the analysis, it was noted that there was a significant influence between government policy, quality of human resources and professional institutions on welding technology. The coefficients are characterized by a positive direct relationship, which means that the higher the quality of government policy and human resources professionals variables, the higher the value of the institute of welding technology.

Social implications

This study recommends that government should create policies that have benefits to competitiveness of Indonesian workforce. Implications from this study support government to use the model to determine and initiate policies in the field of welding as well as establish clear and standardized operating standards and recruitment process (government apparatus) that can accommodate the competitiveness of welding workers in Indonesia.

Originality/value

The originality of this paper is that the participatory approach was adopted in this study using PLS-SEM. In addition, this study was one of the first studies to carry out research at the BNSP office, BLK-Bandung-Jakarta, Makassar, B4T and dismiss the Ministry of Manpower and the Ministry of Industry in Jakarta, Indonesia, where there was no research in this location. Previous studies conducted research in various case studies.
Chronicles of one woman’s journey towards well-being: acceptance
Authors: Mullen Jo
Published: November 2019

Purpose

The purpose of this paper is to share the experiences and reflections of one woman’s journey towards well-being.

Design/methodology/approach

A narrative approach has been taken to structure reflections based on lived experience.

Findings

Reflections are offered based on a personal journey towards well-being.

Originality/value

This paper adds to the accounts of the lived experience of the journey towards well-being, and as such, contributes to the understanding of the process of rebuilding a life.
Evaluating the online shopping behavior among Egyptian college-educated community
Authors: Aref Mayada M. , Okasha Ahmed E.
Published: November 2019

Purpose

In a dynamic environment, understanding the consumer’s behavior in an online market is critical for the development of online retailers’ strategies. In Egypt, although the number of internet users is growing rapidly, online shopping is at an early stage of development. In addition, there is a lack of knowledge about the behavior of Egyptians toward online shopping and the factors that influence their behavior.

Design/methodology/approach

To demonstrate the applicability of the technology acceptance model (TAM), this research applies an extended TAM to analyze the factors that impact the Egyptian consumers’ online shopping behavior. Structural equation modeling is used for fitting the data and testing the hypothesis.

Findings

Findings revealed that perceived enjoyment, perceived ease of use, social norm and perceived risk have significant influences on the respondents to shop online; while the site language effect was insignificant.

Research limitations/implications

This study has mainly four limitations. The first concerning the sample, it should cover diversified areas other than Cairo and should include respondents from different education levels. Future studies may consider using a national sample of current and potential online shoppers to be able to generalize the results. Second, the questionnaire should include questions about the levels of education and the level of income to analyze if they influence actual online shopping. Third, although the benefits of using online surveys such as reducing the costs and time and collecting data more accurately compared to paper-pencil surveys, the low response rate may lead to non-response bias. Finally, constructs such as website content, design, and response could be added to the TAM to examine different aspects of website functionalities on the actual shopping.

Originality/value

Considering that online shopping is still at the early stage of development in Egypt, there is a need to examine the factors that influence the behavior of Egyptian consumers while adopting online shopping. To fill in this gap, this study is analyzing the factors impacting the consumers’ decisions to shop online by examining a sample of students from the Faculty of Economics and Political Science, Cairo University. This study will contribute to providing an empirical application of the TAM on the Egyptian consumers in addition to, enhancing the knowledge of electronic retailers about the factors that drive consumers toward shopping online.
Does stress affect nonverbal engagement in teams? A case study in professional team sport
Authors: Serpell Benjamin G. , Larkham Stephen , Cook Christian J.
Published: November 2019

Purpose

Team effectiveness is often predicated by a group’s ability to communicate. However, the effect of stress response on communication success, particularly nonverbal engagement, and how this might affect team performance, is not clear; a “phenomenon” this study sought to explore.

Design/methodology/approach

This was an observational study in a cohort of professional rugby players. Participants gave presentations to their peers on two separate occasions during a “live-in” camp designed to have psychologically stressful elements. Presentations were video recorded and audience engagement was measured. Testosterone and cortisol were used as biomarkers of stress response, with a high testosterone–cortisol ratio considered positive. A team training session followed the presentations and participants were rated for training quality.

Findings

A small decline in testosterone was observed each day after waking. Conversely, cortisol rose after waking, with the rise being the highest on the first day. A decline in testosterone–cortisol ratio was also seen each day after waking; the decline was greatest on the first day. Presentation duration and audience engagement was greatest for the second presentation; when the testosterone-cortisol ratio decline and the cortisol increase after waking was smaller. Training quality was also better that day. Pooled data revealed a moderate inverse relationship and weak positive relationships for audience engagement with post-meeting cortisol and post-meeting testosterone–cortisol ratio, respectively. Training quality was related to testosterone and testosterone–cortisol ratio, but inversely related to cortisol.

Originality/value

This study suggests that in stressful conditions, as suggested by an awakening hormone response, communication and team performance could become compromised with reduced ability to engage with others.