bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence and Predictive Factors of Sepsis Following Adult Spinal Deformity Surgery
Authors: Zuckerman Scott L , Lakomkin Nikita , Stannard Blaine P , Hadjipanayis Constantinos G , Shaffrey Christopher I , Smith Justin S , Cheng Joseph S
Published: November 2017

BACKGROUND

Surgery for adult spinal deformity (ASD) improves quality of life, yet morbidity is high. Sepsis is a challenging postoperative complication that can result in death and drive inpatient resources.

OBJECTIVE

To identify the incidence and risk factors for development of sepsis within 30 days following ASD surgery.

METHODS

Adult patients who underwent thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program database. Demographic and operative variables were extracted. The primary outcome was development of postoperative sepsis. Multivariable logistic regression modeling was used to identify independent risk factors for sepsis.

RESULTS

A total of 6158 patients underwent ASD surgery. Of these, 156 (2.5%) developed sepsis postoperatively. Independent risk factors included operative time (odds ratio [OR]: 1.004, 95% confidence interval [CI]: 1.003-1.005, P < .001), male sex (OR: 1.47, 95% CI: 1.05-2.05, P = .023), diabetes (OR: 1.59, 95% CI: 1.05-2.40, P = .027), functional dependency (OR: 1.82, 95% CI: 1.12-2.95, P = .015), weight loss (OR: 2.45, 95% CI: 1.04-5.78, P = .040), bleeding disorder (OR: 2.58, 95% CI: 1.34-4.93, P = .004), and ascites (OR: 56.11, 95% CI: 5.01-628.50, P = .001). This model demonstrated strong predictive capacity, with an area under the curve of 0.80. Patients who developed sepsis were significantly more likely to have a prolonged hospital stay (P < .001), be readmitted (P < .001), and die (P < .001). The median (range) time to sepsis was 9 d (0-30).

CONCLUSION

In patients undergoing ASD surgery, male sex, diabetes, ascites, bleeding disorder, functional dependency, excessive weight loss and increased operative time independently predicted sepsis. This perioperative patient profile can be used for preoperative risk assessment, patient counseling, and postoperative management for patients undergoing ASD surgery.
FireCloud, a scalable cloud-based platform for collaborative genome analysis: Strategies for reducing and controlling costs
Authors: Birger Chet , Hanna Megan , Salinas Edward , Neff Jason , Saksena Gordon , Livitz Dimitri , Rosebrock Daniel , Stewart Chip , Leshchiner Ignaty , Baumann Alexander , Voet Douglas , Cibulskis Kristian , Banks Eric , Philippakis Anthony , Getz Gad
Published: November 2017

FireCloud, one of three NCI Cloud Pilots, is a collaborative genome analysis platform built on a cloud computing infrastructure. FireCloud aims to solve the many challenges presented by the increasingly large data sets and computing requirements employed in cancer research. However, cost uncertainty associated with cloud computing’s pay-as-you-go model is proving to be a barrier to adoption of cloud computing. In this paper we present guidelines for optimizing workflows to minimize cost and reduce latency. Our guidelines include: (i) dynamic disk sizing to efficiently utilize virtual disks; (ii) tuned provisioning of virtual machines (VMs) using a performance monitoring tool; (iii) taking advantage of steep price discounts of preemptible VMs; and (iv) utilizing the optimal parallelization of a task’s workload.
Exploring variation in human papillomavirus vaccination uptake: multi-level spatial analysis
Authors: Riesen Maurane , Konstantinoudis Garyfallos , Lang Phung , Low Nicola , Hatz Christoph , Maeusezahl Mirjam , Spaar Anne , Bühlmann Marc , Spycher Ben D. , Althaus Christian L.
Published: November 2017

Background

Understanding the factors that influence human papillomavirus (HPV) vaccination uptake is critically important to design effective vaccination programmes. In Switzerland, completed HPV vaccination by age 16 years among women ranges from 30 to 79% across 26 cantons (states). Our objective was to identify factors that are associated with the spatial variation in HPV vaccination uptake.

Methods and findings

We used data from the Swiss National Vaccination Coverage Survey 2009-2016 on HPV vaccination status (≥1 dose) of 14-17 year old girls, their municipality of residence and their nationality for 21 of 26 cantons (N=8,965). We examined covariates at municipality level: language, degree of urbanisation, socio-economic position, religious denomination, results of a vote about vaccination laws; and, at cantonal level, availability of school-based vaccination and survey period. We used a series of conditional auto regressive (CAR) models to assess the effects of covariates while accounting for variability between cantons and municipal-level spatial autocorrelation. In the best-fit model, school-based vaccination (adjusted odds ratio, OR: 2.51, 95% credible interval, CI: 1.77-3.56) was associated with increased uptake, while lower acceptance of vaccination laws was associated with lower HPV vaccination uptake (OR 0.61, 95% CI: 0.50-0.73). Overall, the covariates explained 88% of the municipal-level variation in uptake.

Conclusions

In Switzerland, cantons play a prominent role in the variation in HPV vaccination uptake, especially through the provision of school-based vaccination delivery. HPV vaccination uptake is also strongly associated with inhabitants’ attitudes towards vaccination. To increase uptake, efforts should be made both to mitigate vaccination scepticism and to encourage school-based vaccination.
Endodermal differentiation is reconstructed by coordination of two parallel signaling systems derived from the stele in roots
Authors: Li Pengxue , Yu Qiaozhi , Xu Chunmiao , Gu Xu , Qi Shilian , Wang Hong , Zhong Fenglin , Wu Shuang
Published: November 2017

The plant roots represent the exquisitely controlled cell fate map in which different cell types undergo a complete status transition from stem cell division and initial fate specification, to the terminal differentiation. The endodermis is initially specified in meristem but further differentiates to form Casparian strips (CSs), the apoplastic barrier in the mature zone for the selective transport between stele and outer tissues, and thus is regarded as plant inner skin. In the Arabidopsis thaliana root the transcription factors SHORTROOT (SHR) regulate asymmetric cell division in cortical initials to separate endodermal and cortex cell layer. In this paper, we utilized synthetic approach to examine the reconstruction of fully functional Casparian strips in plant roots. Our results revealed that SHR serves as a master regulator of a hierarchical signaling cascade that, combined with stele-derived small peptides, is sufficient to rebuild the functional CS in non-endodermal cells. This is a demonstration of the deployment of two parallel signaling systems, in which both apoplastic and symplastic communication were employed, for coordinately specifying the endodermal cell fate.
A potent neutralizing epitope of limited variability in the head domain of haemagglutinin as a novel influenza vaccine target
Authors: Thompson Craig P , Lourenço José , Walters Adam A , Obolski Uri , Edmans Matthew , Palmer Duncan S , Kooblall Kreepa , Carnell George W , Connor Daniel O’ , Bowden Thomas A , Pybus Oliver G , Pollard Andrew J , Temperton Nigel J , Lambe Teresa , Gilbert Sarah C , Gupta Sunetra
Published: November 2017

Antigenic targets of influenza vaccination are currently seen to be polarised between (i) highly immunogenic (and protective) epitopes of high variability, and (ii) conserved epitopes of low immunogenicity. This requires vaccines directed against the variable sites to be continuously updated, with the only other alternative being seen as the artificial boosting of immunity to invariant epitopes of low natural efficacy. However, theoretical models suggest that the antigenic evolution of influenza is best explained by postulating the existence of highly immunogenic epitopes of limited variability. Here we report the identification of such an epitope of limited variability in the head domain of the H1 haemagglutinin protein. We show that the epitope mediates immunity to historical influenza strains not previously seen by a cohort of young children. Furthermore, vaccinating mice with these epitope conformations can induce immunity to all the human H1N1 influenza strains that have circulated since 1918. The identification of epitopes of limited variability offers a mechanism by which a universal influenza vaccine can be created; these vaccines would also have the potential to protect against newly emerging influenza strains.
Pydigree: a python library for manipulation and forward-time simulation and of genetic datasets
Authors: Hicks James E.
Published: November 2017

The development of software for working with data from population genetics or genetic epidemiology often requires substantial time spent implementing common procedures. Pydigree is a cross-platform Python 3 library that contains efficient, user friendly implementations for many of these common functions, and support for input from common file formats. Developers can combine the functions and data structures to rapidly implement programs handling genetic data. Pydigree presents a useful environment for development of applications for genetic data or rapid prototyping before reimplementation in a higher-performance language.

Pydigree is freely available under an open source license. Stable sources can be found in the Python Package Index at https://pypi.python.org/pypi/pydigree/, and development sources can be downloaded at https://github.com/jameshicks/pydigree/
Non-biological synthetic spike-in controls and the AMPtk software pipeline improve mycobiome data
Authors: Palmer Jonathan M , Jusino Michelle A , Banik Mark T , Lindner Daniel L
Published: November 2017

High throughput amplicon sequencing (HTAS) of conserved DNA regions is a powerful technique to characterize microbial communities. Recently, spike-in mock communities have been used to measure accuracy of sequencing platforms and data analysis pipelines. To assess the ability of sequencing platforms and data processing pipelines using fungal ITS amplicons, we created two ITS spike-in control mock communities composed of cloned DNA in plasmids: a biological mock community (BioMock), consisting of ITS sequences from fungal taxa, and a synthetic mock community (SynMock), consisting of non-biological ITS-like sequences. Using these spike-in controls we show that: 1) a non-biological synthetic control (e.g., SynMock) is the best solution for parameterizing bioinformatics pipelines, 2) pre-clustering steps for variable length amplicons are critically important, 3) a major source of bias is attributed to initial PCR reactions and thus HTAS read abundances are typically not representative of starting values. We developed AMPtk, a versatile software solution equipped to deal with variable length amplicons and quality filter HTAS data based on spike-in controls. While we describe herein a non-biological synthetic mock community for ITS sequences, the concept and AMPtk software can be widely applied to any HTAS dataset to improve data quality.
Propofol-Induced Unresponsiveness is Associated with Impaired Feedforward Connectivity in the Cortical Hierarchy
Authors: Sanders Robert D. , Banks Matthew I , Darracq Matthieu , Moran Rosalyn , Sleigh Jamie , Gosseries Olivia , Bonhomme Vincent , Brichant Jean-François , Rosanova Mario , Raz Aeyal , Tononi Giulio , Massimini Marcello , Laureys Steven , Boly Mélanie
Published: November 2017

Background

Impaired consciousness has been associated with impaired cortical signal propagation following transcranial magnetic stimulation (TMS). Herein we hypothesized that the reduced current propagation under propofol-induced unresponsiveness is associated with changes in both feedforward and feedback connectivity across the cortical hierarchy.

Methods

Eight subjects underwent left occipital TMS coupled with high-density electroencephalograph (EEG) recordings during wakefulness and propofol-induced unconsciousness. Spectral analysis was applied to responses recorded from sensors overlying six hierarchical cortical sources involved in visual processing. Dynamic causal modelling (DCM) of evoked and induced source-space responses was used to investigate propofol’s effects on connectivity between regions.

Results

Propofol produced a wideband reduction in evoked power following TMS in five out of six electrodes. Bayesian Model Selection supported a DCM with hierarchical feedforward and feedback connections to best fit the data. DCM of induced responses revealed that the primary effect of propofol was impaired feedforward responses in cross frequency theta/alpha-gamma coupling and within frequency theta coupling (F contrast, Family Wise Error corrected p<0.05). An exploratory analysis (thresholded at uncorrected p<0.001) also suggested that propofol impaired feedforward and feedback beta band coupling. Posthoc analyses showed impairments in all feedforward connections and one feedback connection from parietal to occipital cortex. DCM of the evoked response potential showed impaired feedforward connectivity between left sided occipital and parietal cortex (T contrast p=0.004, Bonferroni corrected).

Conclusions

Our data suggest that propofol-induced loss of consciousness is associated with reduced evoked power and impaired hierarchical feedforward connectivity following occipital TMS.
A multi-center study on factors influencing the reproducibility ofin vitrodrug-response studies
Authors: Niepel Mario , Hafner Marc , Mills Caitlin E. , Subramanian Kartik , Williams Elizabeth H. , Chung Mirra , Gaudio Benjamin , Barrette Anne Marie , Stern Alan D. , Hu Bin , Korkola James E. ,   LINCS Consortium, Gray Joe W. , Birtwistle Marc R. , Heiser Laura M. , Sorger Peter K.
Published: November 2017

Evidence that some influential biomedical results cannot be repeated has increased interest in practices that generate data meeting findable, accessible, interoperable and reproducible (FAIR) standards. Multiple papers have identified examples of irreproducibility, but practical steps for increasing reproducibility have not been widely studied. Here, seven research centers in the NIH LINCS Program Consortium investigate the reproducibility of a prototypical perturbational assay: quantifying the responsiveness of cultured cells to anti-cancer drugs. Such assays are important for drug development, studying cell biology, and patient stratification. While many experimental and computational factors have an impact on intra- and inter-center reproducibility, the factors most difficult to identify and correct are those with a strong dependency on biological context. These factors often vary in magnitude with the drug being analyzed and with growth conditions. We provide ways of identifying such context-sensitive factors, thereby advancing the conceptual and practical basis for greater experimental reproducibility.
Adapting machine-learning algorithms to design gene circuits
Authors: Hiscock Tom
Published: November 2017

Biological systems rely on complex networks, such as transcriptional circuits and protein-protein interaction networks, to perform a variety of functions e.g. responding to stimuli, directing cell fate, or patterning an embryo. Mathematical models are often used to ask: given some network, what function does it perform? However, we often want precisely the opposite i.e. given some circuit – either observedin vivo, or desired for some engineering objective – what biological networks could execute this function? Here, we adapt optimization algorithms from machine learning to rapidly screen and design gene circuits capable of performing arbitrary functions. We demonstrate the power of this approach by designing circuits (1) that recapitulate importantin vivophenomena, such as oscillators, and (2) to perform complex tasks for synthetic biology, such as counting noisy biological events. Our method can be readily applied to biological networks of any type and size, and is provided as an open-source and easy-to-use python module, GeneNet.
Interoperable and scalable data analysis with microservices: Applications in Metabolomics
Authors: Emami Khoonsari Payam , Moreno Pablo , Bergmann Sven , Burman Joachim , Capuccini Marco , Carone Matteo , Cascante Marta , de Atauri Pedro , Foguet Carles , Gonzalez-Beltran Alejandra , Hankemeier Thomas , Haug Kenneth , He Sijin , Herman Stephanie , Johnson David , Kale Namrata , Larsson Anders , Neumann Steffen , Peters Kristian , Pireddu Luca , Rocca-Serra Philippe , Roger Pierrick , Rueedi Rico , Ruttkies Christoph , Sadawi Noureddin , Salek Reza M. , Sansone Susanna-Assunta , Schober Daniel , Selivanov Vitaly , Thévenot Etienne A. , van Vliet Michael , Zanetti Gianluigi , Steinbeck Christoph , Kultima Kim , Spjuth Ola
Published: November 2017

Developing a robust and performant data analysis workflow that integrates all necessary components whilst still being able to scale over multiple compute nodes is a challenging task. We introduce a generic method based on the microservice architecture, where software tools are encapsulated as Docker containers that can be connected into scientific workflows and executed in parallel using the Kubernetes container orchestrator. The access point is a virtual research environment which can be launched on-demand on cloud resources and desktop computers. IT-expertise requirements on the user side are kept to a minimum, and established workflows can be re-used effortlessly by any novice user. We validate our method in the field of metabolomics on two mass spectrometry studies, one nuclear magnetic resonance spectroscopy study and one fluxomics study, showing that the method scales dynamically with increasing availability of computational resources. We achieved a complete integration of the major software suites resulting in the first turn-key workflow encompassing all steps for mass-spectrometry-based metabolomics including preprocessing, multivariate statistics, and metabolite identification. Microservices is a generic methodology that can serve any scientific discipline and opens up for new types of large-scale integrative science.
Degradation of cyclin B is critical for nuclear division inTrypanosoma brucei
Authors: Hayashi Hanako , Akiyoshi Bungo
Published: November 2017

Kinetoplastids have a nucleus that contains the nuclear genome and a kinetoplast that contains the mitochondrial genome. These single-copy organelles must be duplicated and segregated faithfully to daughter cells at each cell division. InTrypanosoma brucei, although duplication of both organelles starts around the same time, segregation of the kinetoplast precedes that of the nucleus. Cytokinesis subsequently takes place so that daughter cells inherit a single copy of each organelle. Very little is known about the molecular mechanism that governs the timing of these events. Furthermore, it is thought thatT. bruceilacks a spindle checkpoint that delays the onset of nuclear division in response to spindle damage. Here we show that a mitotic cyclin CYC6 has a dynamic localization pattern during the cell cycle, including kinetochore localization from G2 to metaphase. Using CYC6 as a molecular cell cycle marker, we confirmed thatT. bruceicannot delay the onset of anaphase in response to a bipolar spindle assembly defect. Interestingly, expression of a stabilized form of CYC6 caused the nucleus to arrest in a metaphase-like state without preventing cytokinesis. We propose that trypanosomes have an ability to regulate the timing of nuclear division by modulating the CYC6 protein level, without a spindle checkpoint.
Prediction Error and Repetition Suppression Have Distinct Effects on Neural Representations of Visual Information
Authors: Tang Matthew F. , Smout Cooper A. , Arabzadeh Ehsan , Mattingley Jason B.
Published: November 2017

Predictive coding theories argue that recent experience establishes expectations in the brain that generate prediction errors when violated. Prediction errors provide a possible explanation for repetition suppression, where evoked neural activity is attenuated across repeated presentations of the same stimulus. The predictive coding account argues repetition suppression arises because repeated stimuli are expected, whereas non-repeated stimuli are unexpected and thus elicit larger neural responses. Here we employed electroencephalography in humans to test the predictive coding account of repetition suppression by presenting sequences of visual gratings with orientations that were expected either to repeat or change in separate blocks of trials. We applied multivariate forward modelling to determine how orientation selectivity was affected by repetition and prediction. Unexpected stimuli were associated with significantly enhanced orientation selectivity, whereas selectivity was unaffected for repeated stimuli. Our results suggest that repetition suppression and expectation have separable effects on neural representations of visual feature information.
Loter: A software package to infer local ancestry for a wide range of species
Authors: Dias-Alves Thomas , Mairal Julien , Blum Michael G.B.
Published: November 2017

Admixture between populations provides opportunity to study biological adaptation and phenotypic variation. Admixture studies rely on local ancestry inference for admixed individuals, which consists of computing at each locus the number of copies that originate from ancestral source populations. Existing software packages for local ancestry inference are tuned to provide accurate results on human data and recent admixture events. Here, we introduce Loter, an open-source software package that does not require any biological parameter besides haplotype data in order to make local ancestry inference available for a wide range of species. Using simulations, we compare the performance of Loter to HAPMIX, LAMP-LD, and RFMix. HAPMIX is the only software severely impacted by imperfect haplotype reconstruction. Loter is the less impacted software by increasing admixture time when considering simulated and admixed human genotypes. For simulations of admixed Populus genotypes, Loter and LAMP-LD are robust to increasing admixture times by contrast to RFMix. When comparing length of reconstructed and true ancestry tracts, Loter and LAMP-LD provide results whose accuracy is again more robust than RFMix to increasing admixture times. We apply Loter to individuals resulting from admixture betweenPopulus trichocarpaandPopulus balsamiferaand lengths of ancestry tracts indicate that admixture took place around 100 generations ago. We expect that providing a rapid and parameter-free software for local ancestry inference will make more accessible genomic studies about admixture processes.
Sensitivity to sequencing depth in single-cell cancer genomics
Authors: Alves João M. , Posada David
Published: November 2017

Background

Querying cancer genomes at single-cell resolution is expected to provide a powerful framework to understand in detail the dynamics of cancer evolution. However, given the high costs currently associated with single-cell sequencing, together with the inevitable technical noise arising from single-cell genome amplification, cost-effective strategies that maximize the quality of single-cell data are critically needed. Taking advantage of five published single-cell whole-genome and whole-exome cancer datasets, we studied the impact of sequencing depth and sampling effort towards single-cell variant detection, including structural and driver mutations, genotyping accuracy, clonal inference and phylogenetic reconstruction, using recent tools specifically designed for single-cell data.

Results

Altogether, our results suggest that, for relatively large sample sizes (25 or more cells), sequencing single tumor cells at depths >5x does not drastically improve somatic variant discovery, the characterization of clonal genotypes or the estimation of phylogenies from single tumor cells.

Conclusions

We demonstrate that sequencing many individual tumor cells at a modest depth represents an effective alternative to explore the mutational landscape and clonal evolutionary patterns of cancer genomes, without the excessively high costs associated with high-coverage genome sequencing.
Technology-independent estimation of cell type composition using differentially methylated regions
Authors: Hicks Stephanie C. , Irizarry Rafael A.
Published: November 2017

Background

High-resolution genome-wide measurement of DNA methylation (DNAm) has become a widely used assay in biomedical research. A major challenge in measuring DNAm is variability introduced from intra-sample cellular heterogeneity, which is a convolution of DNAm profiles across cell types. When this source of variability is confounded with an outcome of interest, if unaccounted for, false positives ensue. This is particularly problematic in epigenome-wide association studies for human disease performed on whole blood, a heterogeneous tissue. To account for this source of variability, a first step is to determine the actual cell proportions of each sample. Currently, the most effective approach is based on fitting a linear model in which one assumes the DNAm profiles of the representative cell types are known. However, we can only make this assumption when a dedicated experiment is performed to provide a plug-in estimate for these profiles. Although this method works well in practice, technology-specific biases lead to platform-dependent plug-in profiles. As a result, to apply the current methods across technologies we are required to repeat these costly experiments for each platform.

Results

Here, we present a method that accurately estimates cell proportions agnostic to platform by first using experimental data to identify regions in which each cell type is clearly methylated or unmethlyated and model these as latent states. While the continuous measurements used in the linear model approaches are affected by platform-specific biases, the latent states are biologically driven and therefore technology independent, implying that experimental data only needs to be collected once. We demonstrate that our method accurately estimates the cell composition from whole blood samples and is applicable across multiple platforms, including microarray and sequencing platforms.
Coherent olfactory bulb gamma oscillations arise from coupling independent columnar oscillators
Authors: Peace Shane T. , Johnson Benjamin C. , Werth Jesse C. , Li Guoshi , Kaiser Martin E. , Fukunaga Izumi , Schaefer Andreas T. , Molnar Alyosha C. , Cleland Thomas A.
Published: November 2017

Spike timing-based representations of sensory information depend on embedded dynamical frameworks within neuronal networks that establish the rules of local computation and interareal communication. Here, we investigated the dynamical properties of olfactory bulb circuitry in mice of both sexes using microelectrode array recordings from slice andin vivopreparations. Neurochemical activation or optogenetic stimulation of sensory afferents evoked persistent gamma oscillations in the local field potential. These oscillations arose from slower, GABA(A) receptor-independent intracolumnar oscillators coupled by GABA(A)-ergic synapses into a faster, broadly coherent network oscillation. Consistent with the theoretical properties of coupled-oscillator networks, the spatial extent of zero-phase coherence was bounded in slices by the reduced density of lateral interactions. The intactin vivonetwork, however, exhibited long-range lateral interactions that suffice in simulation to enable zero-phase gamma coherence across the olfactory bulb. The timing of action potentials in a subset of principal neurons was phase-constrained with respect to evoked gamma oscillations. Coupled-oscillator dynamics in olfactory bulb thereby enable a common clock, robust to biological heterogeneities, that is capable of supporting gamma-band spike synchronization and phase coding across the ensemble of activated principal neurons.

New & Noteworthy

Odor stimulation evokes rhythmic gamma oscillations in the field potential of the olfactory bulb, but the dynamical mechanisms governing these oscillations have remained unclear. Establishing these mechanisms is important, as they determine the biophysical capacities of the bulbar circuit to, for example, maintain zero-phase coherence across a spatially extended network, or coordinate the timing of action potentials in principal neurons. These properties in turn constrain and suggest hypotheses of sensory coding.
Toyota Hilux: how South Africa’s top pickup battled market challenges
Authors: Pheko Samenthea , Bick Geoff , Barnardo Claire
Published: November 2017

Subject area

The Toyota Hilux case has been designed to show the complexities associated with managerial decision-making in a highly competitive vehicle market in South Africa. The case centres on the challenges the Toyota Hilux faced in sustaining its market leadership position amid intense competition from its rivals and changing customer preferences.

Study level/applicability

The case is suited to marketing and strategy students who are eager to demonstrate their critical thinking and managerial decision-making skills as part of their Masters of Business Administration (MBA) and Executive MBA academic programmes, and delegates on Executive Education programmes.

Case overview

The teaching case focuses on the Toyota Hilux brand and the various business dilemmas that Calvyn Williams, sales and marketing manager, and his team experience prior to the launch of the next Hilux: the fierce competition from other brands and the various marketing strategies used.

Expected learning outcomes

The objective of this teaching case is to afford students a “hands-on” understanding and appreciation of the challenges faced by market leaders in sustaining their dominance and selecting the most appropriate strategies for market leaders to adopt in extremely competitive environments such as the South African vehicle market.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 8: Marketing.
High Carbon Stock forests provide co‐benefits for tropical biodiversity
Authors: Deere Nicolas J. , Guillera‐Arroita Gurutzeta , Baking Esther L. , Bernard Henry , Pfeifer Marion , Reynolds Glen , Wearn Oliver R. , Davies Zoe G. , Struebig Matthew J.
Published: November 2017

Carbon‐based policies provide powerful opportunities to unite tropical forest conservation with climate change mitigation. However, their effectiveness in delivering biodiversity co‐benefits is dependent on high levels of biodiversity being found in high carbon areas. Previous studies have focussed solely on the co‐benefits associated with Reducing Emissions from Deforestation and forest Degradation (REDD+) over large spatial scales, with few empirically testing carbon‐biodiversity correlations at management unit scales appropriate to decision‐makers. Yet, in development frontiers, where most biodiversity and carbon loss occurs, carbon‐based policies are increasingly driven by commodity certification schemes, which are applied at the concession level.

Working in a typical human‐modified landscape in Southeast Asia, we examined the biodiversity value of land prioritised via application of REDD+ or the High Carbon Stock (HCS) approach, the emerging land‐use planning tool for oil palm certification. Carbon stocks were estimated via low‐ and high‐resolution datasets derived from global or local‐level biomass. Mammalian species richness was predicted using hierarchical Bayesian multispecies occupancy models of camera‐trap data from forest and oil palm habitats.

At the community level, HCS forest supported comparable mammal diversity to control sites in continuous forest, while lower carbon strata exhibited reduced species occupancy.

No association was found between species richness and carbon when the latter was estimated using coarse‐resolution data. However, when using high‐resolution, locally validated biomass data, diversity demonstrated positive relationships with carbon for threatened and disturbance‐sensitive species, suggesting sensitivity of co‐benefits to carbon data sources and the species considered.

Policy implications. Our work confirms the potential for environmental certification and Reducing Emissions from Deforestation and forest Degradation to work in tandem with conservation to mitigate agricultural impacts on tropical forest carbon stocks and biodiversity. Successful implementation of both approaches could be used to direct development to low carbon, low biodiversity areas in tropical countries.
The role of bryophytes for tree seedling responses to winter climate change: Implications for the stress gradient hypothesis
Authors: Lett Signe , Wardle David A. , Nilsson Marie‐Charlotte , Teuber Laurenz M. , Dorrepaal Ellen
Published: November 2017

When tree seedlings establish beyond the current tree line due to climate warming, they encounter existing vegetation, such as bryophytes that often dominate in arctic and alpine tundra. The stress gradient hypothesis (SGH) predicts that plant interactions in tundra become increasingly negative as climate warms and conditions become less harsh. However, for seedlings, climate warming might not result in lower winter stress, if insulating snow cover is reduced.

We aimed to understand if bryophytes facilitate seedling survival in a changing winter climate and if these effects of bryophytes on tree seedlings comply with theSGHalong elevational gradients under contrasting snow conditions.

In the Swedish subarctic, we transplanted intact bryophyte cores covered by each of three bryophyte species and bryophyte‐free control soil from above the tree line to two field common garden sites, representing current and future tree line air temperature conditions (i.e. current tree line elevation and a lower, warmer, elevation below the tree line). We planted seedlings ofBetula pubescensandPinus sylvestrisinto these cores and subjected them to experimental manipulation of snow cover during one winter.

In agreement with theSGH, milder conditions caused by increased snow cover enhanced the generally negative or neutral effects of bryophytes on seedlings immediately after winter. Furthermore, survival ofP. sylvestrisseedlings after one full year was higher at lower elevation, especially when snow cover was thinner. However, in contrast with theSGH, impacts of bryophytes on over‐winter survival of seedlings did not differ between elevations, and impacts on survival ofB. pubescensseedlings after 1 year was more negative at lower elevation. Bryophyte species differed in their effect on seedling survival after winter, but these differences were not related to their insulating capacity.

Synthesis. Our study demonstrates that interactions from bryophytes can modify the impacts of winter climate change on tree seedlings, andvice versa. These responses do not always comply withSGH, but could ultimately have consequences for large‐scale ecological processes such as tree line shifts. These new insights need to be taken into account in predictions of plant species responses to climate change.
Simulated caribou browsing limits the effect of nutrient addition on the growth of Betula glandulosa, an expanding shrub species in Eastern Canada
Authors: Morrissette‐Boileau Clara , Boudreau Stéphane , Tremblay Jean‐Pierre , Côté Steeve D.
Published: November 2017

Warmer summer temperatures and enhanced soil fertility increase shrub growth in tundra ecosystems, and these factors have likely contributed to shrub expansion at the circumpolar scale over the last decades. Conversely, large herbivores have the potential to counteract the positive impacts of climate change on shrub growth. Indeed, by stripping the leaves, herbivores have the potential to control the growth of shrub species and, consequently, limit their expansion.

To disentangle the impacts of climate change and herbivory on Betula glandulosa Michx., we conducted a 5‐year factorial experiment near Deception Bay, Nunavik, Canada, in which we simulated warmer temperatures, increased nitrogen availability and three caribou browsing intensities during the growing season. At the end of the experiment, we harvested the above‐ground biomass of B. glandulosa and conducted dendrochronological analyses on stems.

Fertilised plots under ambient temperature had 34% greater shrub biomass than plots assigned to the combined treatment of nitrogen addition and warmer temperatures. Browsing intensity had no effect on final biomass. Nitrogen addition increased radial growth (18%–33%; 3 years out of 5). Overall, browsing had a cumulative negative impact on B. glandulosa radial growth during the 5‐year experiment. While browsing had no effect in the first year of the experiment, moderate browsing (leaves stripped on 25% of available shoots) decreased radial growth by 27% at year 2, 32% at year 4 and 27% at year 5. Heavy browsing (leaves stripped on 75% of available shoots annually) decreased radial growth by c. 27% at year 2, 37% at year 3, 50% at year 4 and 48% at year 5. We did not observe significant interactions between browsing, temperature and nitrogen availability.

Synthesis. Our results clearly showed that caribou browsing may limit the growth of B. glandulosa, and thus can potentially limit its expansion. Herbivory should thus be considered when predicting tundra vegetation changes in the Arctic, at least in areas with high herbivore densities.
Effects of stress interviews on selection/recruitment function of employment interviews
Authors: Chen Chien‐Cheng , Lee Yu‐Hsuang , Huang Ting‐Chun , Ko Shu‐Fen
Published: November 2017

Stress interviews can help interviewers effectively measure and evaluate job applicants’ emotion regulation in highly stressful settings. This research uses 90 applicants and 62 interviewers as a sample in real interview settings. Results show that there was a positive relationship between interviewers’ use of stress interviews and the interviewers’ accuracy in assessing applicants’ emotion‐regulation abilities, but that there was a negative relationship between interviewers’ use of stress interviews and applicants’ perceptions of interviewer friendliness and organizational attraction. Implications of this study's findings, contributions, and limitations, as well as future research directions, are discussed.
Comparing Statewide and Single‐center Data to Predict High‐frequency Emergency Department Utilization Among Patients With Asthma Exacerbation
Authors: Samuels‐Kalow Margaret E. , Faridi Mohammad K. , Espinola Janice A. , Klig Jean E. , Camargo Carlos A.
Published: November 2017

Background

Previous studies examining high‐frequency emergency department (ED) utilization have primarily used single‐center data, potentially leading to ascertainment bias if patients visit multiple centers. The goals of this study were 1) to create a predictive model to prospectively identify patients at risk of high‐frequency ED utilization for asthma and 2) to examine how that model differed using statewide versus single‐center data.

Methods

To track ED visits within a state, we analyzed 2011 to 2013 data from the New York State Healthcare Cost and Utilization Project State Emergency Department Databases. The first year of data (2011) was used to determine prior utilization, 2012 was used to identify index ED visits for asthma and for demographics, and 2013 was used for outcome ascertainment. High‐frequency utilization was defined as 4+ ED visits for asthma within 1 year after the index visit. We performed analyses separately for children (age < 21 years) and adults and constructed two models: one included all statewide (multicenter) visits and the other was restricted to index hospital (single‐center) visits. Multivariable logistic regression models were developed from potential predictors selected a priori. The final model was chosen by evaluating model performance using Akaike's Information Criterion scores, 10‐fold cross‐validation, and receiver operating characteristic curves.

Results

Among children, high‐frequency ED utilization for asthma was observed in 2,417 of 94,258 (2.56%) using all statewide visits, compared to 1,853 of 94,258 (1.97%) for index hospital visits only. Among adults, the corresponding results were 7,779 of 159,874 (4.87%) and 5,053 of 159,874 (3.16%), respectively. In the multicenter visit model, the area under the curve (AUC) from 10‐fold cross‐validation for children was 0.70 (95% confidence interval [CI] = 0.69–0.72), compared to 0.71 (95% CI = 0.69–0.72) in the single‐center visit model. The corresponding AUC results for adults were 0.76 (95% CI = 0.76–0.77) and 0.76 (95% CI = 0.75–0.77), respectively.

Conclusion

Data available at the index ED visit can predict subsequent high‐frequency utilization for asthma with AUC ranging from 0.70 to 0.76. Model accuracy was similar regardless of whether outcome ascertainment included all statewide visits (multicenter) or was limited to the index hospital (single‐center).
Rheumatic heart disease in pregnancy: How can health services adapt to the needs of Indigenous women? A qualitative study
Authors: Belton Suzanne , Kruske Sue , Jackson Pulver Lisa , Sherwood Juanita , Tune Kylie , Carapetis Jonathan , Vaughan Geraldine , Peek Michael , McLintock Claire , Sullivan Elizabeth
Published: November 2017

Objectives

To study rheumatic heart disease health literacy and its impact on pregnancy, and to identify how health services could more effectively meet the needs of pregnant women with rheumatic heart disease.

Materials and methods

Researchers observed and interviewed a small number of Aboriginal women and their families during pregnancy, childbirth and postpartum as they interacted with the health system. An Aboriginal Yarning method of relationship building over time, participant observations and interviews with Aboriginal women were used in the study. The settings were urban, island and remote communities across the Northern Territory. Women were followed interstate if they were transferred during pregnancy. The participants were pregnant women and their families. We relied on participants’ abilities to tell their own experiences so that researchers could interpret their understanding and perspective of rheumatic heart disease.

Results

Aboriginal women and their families rarely had rheumatic heart disease explained appropriately by health staff and therefore lacked understanding of the severity of their illness and its implications for childbearing. Health directives in written and spoken English with assumed biomedical knowledge were confusing and of limited use when delivered without interpreters or culturally appropriate health supports.

Conclusions

Despite previous studies documenting poor communication and culturally inadequate care, health systems did not meet the needs of pregnant Aboriginal women with rheumatic heart disease. Language‐appropriate health education that promotes a shared understanding should be relevant to the gender, life‐stage and social context of women with rheumatic heart disease.
Influenza burden, prevention, and treatment in asthma‐A scoping review by the EAACI Influenza in asthma task force
Authors: Schwarze J. , Openshaw P. , Jha A. , del Giacco S. R. , Firinu D. , Tsilochristou O. , Roberts G. , Selby A. , Akdis C. , Agache I. , Custovic A. , Heffler E. , Pinna G. , Khaitov M. , Nikonova A. , Papadopoulos N. , Akhlaq A. , Nurmatov U. , Renz H. , Sheikh A. , Skevaki C.
Published: November 2017

To address uncertainties in the prevention and management of influenza in people with asthma, we performed a scoping review of the published literature on influenza burden; current vaccine recommendations; vaccination coverage; immunogenicity, efficacy, effectiveness, and safety of influenza vaccines; and the benefits of antiviral drugs in people with asthma. We found significant variation in the reported rates of influenza detection in individuals with acute asthma exacerbations making it unclear to what degree influenza causes exacerbations of underlying asthma. The strongest evidence of an association was seen in studies of children. Countries in the European Union currently recommend influenza vaccination of adults with asthma; however, coverage varied between regions. Coverage was lower among children with asthma. Limited data suggest that good seroprotection and seroconversion can be achieved in both children and adults with asthma and that vaccination confers a degree of protection against influenza illness and asthma‐related morbidity to children with asthma. There were insufficient data to determine efficacy in adults. Overall, influenza vaccines appeared to be safe for people with asthma. We identify knowledge gaps and make recommendations on future research needs in relation to influenza in patients with asthma.
Efficacy and safety of intravenous vernakalant for the rapid conversion of recent‐onset atrial fibrillation: A meta‐analysis
Authors: Akel Tamer , Lafferty James
Published: November 2017

Background

Atrial fibrillation is a common cardiac arrhythmia with increasing prevalence in the aging population. It is a major cause of emergency department visits worldwide. Vernakalant, a relatively new antiarrhythmic drug with selectively preferential effects on the atrial tissue is currently used in many European countries for the termination of recent‐onset atrial fibrillation. Presently, the drug is still not approved by the United States Food and Drug Administration due to safety concerns. We evaluate the efficacy and safety of vernakalant for the conversion of recent‐onset atrial fibrillation or atrial flutter into normal sinus rhythm (NSR).

Methods

PubMed/MEDLINE (1993–2017), the Cochrane Central Register of Controlled Trials (2000–2017), and reference lists of relevant articles were searched for randomized controlled trials (RCTs) comparing vernakalant to a control drug and extracted subsequently.

Results

Nine RCTs were identified and included in the meta‐analysis. Pooled analysis of events extracted for a total of 1421 patients with recent‐onset atrial fibrillation showed a statistically significant increase in cardioversion within 90 minutes from drug infusion (Relative Risk [RR], 6.61; 95% Confidence Interval [CI], 2.78 – 15.71; p < .00001). In terms of adverse events, vernakalant was considered safe in comparison to control drugs (RR, 0.80; 95% CI, 0.61–1.05; p = .11).

Conclusion

Vernakalant is effective for rapid conversion of recent‐onset atrial fibrillation into NSR. However, although it showed a safe profile in terms of side effects in this analysis, we are still hesitant about this conclusion and few safety issues should be addressed within specific patients’ subgroups.
Genetic prognostication in uveal melanoma
Authors: Dogrusöz Mehmet , Jager Martine J.
Published: November 2017

Uveal melanoma (UM) is a rare tumour with a high propensity to metastasize. Although no effective treatment for metastases yet exists, prognostication in UM is relevant for patient counselling, planning of follow‐up and stratification in clinical trials. Besides conventional clinicopathologic characteristics, genetic tumour features with prognostic significance have been identified. Non‐random chromosome aberrations such as monosomy 3 and gain of chromosome 8q are strongly correlated with metastatic risk, while gain of chromosome 6p indicates a low risk. Recently, mutations in genes such as BAP1, SF3B1 and EIF1AX have been shown to be related to patient outcome. Genetics of UM is a rapidly advancing field, which not only contributes to the understanding of the pathogenesis of this cancer, but also results in further refinement of prognostication. Concomitantly, advances have been made in the use of genetic tests. New methods for genetic typing of UM have been developed. Despite the considerable progress made recently, many questions remain, such as those relating to the reliability of prognostic genetic tests, and the use of biopsied or previously irradiated tumour tissue for prognostication by genetic testing. In this article, we review genetic prognostic indicators in UM, also comparing available genetic tests, addressing the clinical application of genetic prognostication and discussing future perspectives for improving genetic prognostication in UM.