bluuebunny/crossref_metadata_2025 huggingface dataset:
A biochemo-mechano coupled, computational model combining membrane transport and pericellular proteolysis in tissue mechanics
Authors: Vuong A.-T. , Rauch A. D. , Wall W. A.
Published: March 2017

We present a computational model for the interaction of surface- and volume-bound scalar transport and reaction processes with a deformable porous medium. The application in mind is pericellular proteolysis, i.e. the dissolution of the solid phase of the extracellular matrix (ECM) as a response to the activation of certain chemical species at the cell membrane and in the vicinity of the cell. A poroelastic medium model represents the extra cellular scaffold and the interstitial fluid flow, while a surface-bound transport model accounts for the diffusion and reaction of membrane-bound chemical species. By further modelling the volume-bound transport, we consider the advection, diffusion and reaction of sequestered chemical species within the extracellular scaffold. The chemo-mechanical coupling is established by introducing a continuum formulation for the interplay of reaction rates and the mechanical state of the ECM. It is based on known experimental insights and theoretical work on the thermodynamics of porous media and degradation kinetics of collagen fibres on the one hand and a damage-like effect of the fibre dissolution on the mechanical integrity of the ECM on the other hand. The resulting system of partial differential equations is solved via the finite-element method. To the best of our knowledge, it is the first computational model including contemporaneously the coupling between (i) advection–diffusion–reaction processes, (ii) interstitial flow and deformation of a porous medium, and (iii) the chemo-mechanical interaction impelled by the dissolution of the ECM. Our numerical examples show good agreement with experimental data. Furthermore, we outline the capability of the methodology to extend existing numerical approaches towards a more comprehensive model for cellular biochemo-mechanics.
Emerging surface characterization techniques for carbon steel corrosion: a critical brief review
Authors: Dwivedi D. , Lepkova K. , Becker T.
Published: March 2017

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.
Resistive-pulse and rectification sensing with glass and carbon nanopipettes
Authors: Wang Yixian , Wang Dengchao , Mirkin Michael V.
Published: March 2017

Along with more prevalent solid-state nanopores, glass or quartz nanopipettes have found applications in resistive-pulse and rectification sensing. Their advantages include the ease of fabrication, small physical size and needle-like geometry, rendering them useful for local measurements in small spaces and delivery of nanoparticles/biomolecules. Carbon nanopipettes fabricated by depositing a thin carbon layer on the inner wall of a quartz pipette provide additional means for detecting electroactive species and fine-tuning the current rectification properties. In this paper, we discuss the fundamentals of resistive-pulse sensing with nanopipettes and our recent studies of current rectification in carbon pipettes.
Genomic islands of divergence or opportunities for introgression?
Authors: Bay Rachael A. , Ruegg Kristen
Published: March 2017

In animals, introgression between species is often perceived as the breakdown of reproductive isolating mechanisms, but gene flow between incipient species can also represent a source for potentially beneficial alleles. Recently, genome-wide datasets have revealed clusters of differentiated loci (‘genomic islands of divergence’) that are thought to play a role in reproductive isolation and therefore have reduced gene flow. We use simulations to further examine the evolutionary forces that shape and maintain genomic islands of divergence between two subspecies of the migratory songbird, Swainson's thrush (
Catharus ustulatus
), which have come into secondary contact since the last glacial maximum. We find that, contrary to expectation, gene flow is high within islands and is highly asymmetric. In addition, patterns of nucleotide diversity at highly differentiated loci suggest selection was more frequent in a single ecotype. We propose a mechanism whereby beneficial alleles spread via selective sweeps following a post-glacial demographic expansion in one subspecies and move preferentially across the hybrid zone. We find no evidence that genomic islands are the result of divergent selection or reproductive isolation, rather our results suggest that differentiated loci both within and outside islands could provide opportunities for adaptive introgression across porous species boundaries.
Diverted by dazzle: perceived movement direction is biased by target pattern orientation
Authors: Hughes Anna E. , Jones Christian , Joshi Kaustuv , Tolhurst David J.
Published: March 2017

‘Motion dazzle’ is the hypothesis that predators may misjudge the speed or direction of moving prey which have high-contrast patterning, such as stripes. However, there is currently little experimental evidence that such patterns cause visual illusions. Here, observers binocularly tracked a Gabor target, moving with a linear trajectory randomly chosen within 18° of the horizontal. This target then became occluded, and observers were asked to judge where they thought it would later cross a vertical line to the side. We found that internal motion of the stripes within the Gabor biased judgements as expected: Gabors with upwards internal stripe motion relative to the overall direction of motion were perceived to be crossing above Gabors with downwards internal stripe movement. However, surprisingly, we found a much stronger effect of therigidpattern orientation. Patches with oblique stripes pointing upwards relative to the direction of motion were perceived to cross above patches with downward-pointing stripes. This effect occurred only at high speeds, suggesting that it may reflect an orientation-dependent effect in which spatial signals are used in direction judgements. These findings have implications for our understanding of motion dazzle mechanisms and how human motion and form processing interact.
Early-life inflammation, immune response and ageing
Authors: Khan Imroze , Agashe Deepa , Rolff Jens
Published: March 2017

Age-related diseases are often attributed to immunopathology, which results in self-damage caused by an inappropriate inflammatory response. Immunopathology associated with early-life inflammation also appears to cause faster ageing, although we lack direct experimental evidence for this association. To understand the interactions between ageing, inflammation and immunopathology, we used the mealworm beetleTenebrio molitoras a study organism. We hypothesized that phenoloxidase, an important immune effector in insect defence, may impose substantial immunopathological costs by causing tissue damage to Malpighian tubules (MTs; functionally equivalent to the human kidney), in turn accelerating ageing. In support of this hypothesis, we found that RNAi knockdown of phenoloxidase (PO) transcripts in young adults possibly reduced inflammation-induced autoreactive tissue damage to MTs, and increased adult lifespan. Our work thus suggests a causative link between immunopathological costs of early-life inflammation and faster ageing. We also reasoned that if natural selection weakens with age, older individuals should display increased immunopathological costs associated with an immune response. Indeed, we found that while old infected individuals cleared infection faster than young individuals, possibly they also displayed exacerbated immunopathological costs (larger decline in MT function) and higher post-infection mortality. RNAi-mediated knockdown of PO response partially rescued MTs function in older beetles and resulted in increased lifespan after infection. Taken together, our data are consistent with a direct role of immunopathological consequences of immune response during ageing in insects. Our work is also the first report that highlights the pervasive role of tissue damage under diverse contexts of ageing and immune response.
Exact sequence variants should replace operational taxonomic units in marker gene data analysis
Authors: Callahan Benjamin J , McMurdie Paul J , Holmes Susan P
Published: March 2017

Recent advances have made it possible to analyze high-throughput marker-gene sequencing data without resorting to the customary construction of molecular operational taxonomic units (OTUs): clusters of sequencing reads that differ by less than a fixed dissimilarity threshold. New methods control errors sufficiently that sequence variants (SVs) can be resolved exactly, down to the level of single-nucleotide differences over the sequenced gene region. The benefits of finer taxonomic resolution are immediately apparent, and arguments for SV methods have focused on their improved resolution. Less obvious, but we believe more important, are the broad benefits deriving from the status of SVs asconsistent labelswithintrinsic biological meaningidentifiedindependently from a reference database. Here we discuss how those features grant SVs the combined advantages of closed-reference OTUs — including computational costs that scale linearly with study size, simple merging between independently processed datasets, and forward prediction — and of de novo OTUs — including accurate diversity measurement and applicability to communities lacking deep coverage in reference databases. We argue that the improvements in reusability, reproducibility and comprehensiveness are sufficiently great that SVs should replace OTUs as the standard unit of marker gene analysis and reporting.
On the genetic and environmental reasons why intelligence correlates with criminal victimization
Authors: Boutwell Brian B. , Connolly Eric J. , Barbaro Nicole , Shackelford Todd K. , Petkovsek Melissa , Beaver Kevin M.
Published: March 2017

Researchers have expended considerable effort to understand the causes and correlates of criminal victimization. More recently, scholars have focused on identifying individual-level traits that increase the odds of victimization. Generally absent from this line of research, however, is examining the extent to which previously unmeasured genetic and environmental influences contribute to the covariation between victimization and individual-level risk factors. The current study aims to replicate and extend prior research by examining the contribution of genetic and environmental influences on the association between intelligence and victimization by analyzing twin and sibling data from two nationally representative samples of American youth. Quantitative genetic analyses indicate that common additive genetic factors, as well as non-shared environmental factors, explained the phenotypic association between intelligence and victimization. Finally, our results revealed that after correcting for possible familial confounding, the effect of intelligence on victimization experiences remained statistically significant. The findings of the current study replicate and extend prior research on the phenotypic association between indicators of general intelligence and the experience of victimization.
Alzheimer related genes show accelerated evolution
Authors: Nitsche Anne , Reiche Kristin , Ueberham Uwe , Arnold Christian , Hackermüller Jörg , Horn Friedemann , Stadler Peter F. , Arendt Thomas
Published: March 2017

Alzheimer's disease (AD) is a neurodegenerative disorder of unknown cause with complex genetic and environmental traits. Here, we show that gene structures of loci, that show AD-associated changes in their expression, evolve faster than the genome at large. This phylogenetic trait of AD suggests a critical pathogenetic role of recent adaptive evolution of human brain and might have far reaching consequences with respect to the appropriateness of model systems and the development of disease-modifying strategies.
Microfluidic-based mini-metagenomics enables discovery of novel microbial lineages from complex environmental samples
Authors: Brian Yu Feiqiao , Blainey Paul C. , Schulz Frederik , Woyke Tanja , Horowitz Mark A. , Quake Stephen R.
Published: March 2017

Metagenomics and single-cell genomics have enabled the discovery of many new genomes from previously unknown branches of life. However, extracting novel genomes from complex mixtures of metagenomic data can still be challenging and in many respects represents an ill-posed problem which is generally approached with ad hoc methods. Here we present a microfluidic-based mini-metagenomic method which offers a statistically rigorous approach to extract novel microbial genomes from complex samples. In addition, by generating 96 sub-samples from each environmental sample, this method maintains high throughput, reduces sample complexity, and preserves single-cell resolution. We used this approach to analyze two hot spring samples from Yellowstone National Park and extracted 29 new genomes larger than 0.5 Mbps. These genomes represent novel lineages at different taxonomic levels, including three deeply branching lineages. Functional analysis revealed that these organisms utilize diverse pathways for energy metabolism. The resolution of this mini-metagenomic method enabled accurate quantification of genome abundance, even for genomes less than 1% in relative abundance. Our analyses also revealed a wide range of genome level single nucleotide polymorphism (SNP) distributions with nonsynonymous to synonymous ratio indicative of low to moderate environmental selection. The scale, resolution, and statistical power of microfluidic-based mini-metagenomic make it a powerful tool to dissect the genomic structure microbial communities while effectively preserving the fundamental unit of biology, the single cell.
TRPV1 activation relies on hydration/dehydration of nonpolar cavities
Authors: Kasimova Marina A. , Yazici Aysenur , Yudin Yevgen , Granata Daniele , Klein Michael L. , Rohacs Tibor , Carnevale Vincenzo
Published: March 2017

TRPV1 promotes cationic currents across cellular membranes in response to multiple stimuli such as increased temperature, binding of chemicals, low pH and voltage. The molecular underpinnings of TRPV1 gating, in particular the mechanism of temperature sensitivity, are still largely unknown. Here, we used molecular simulations and electrophysiology to shed light on the closed to open transition. Specifically, we found that gating of TRPV1 relies on the motion of an evolutionarily conserved amino acid (N676) in the middle of the S6 helix. On rotation, the side chain of this asparagine faces either the central pore or the S4-S5 linker. Only in the former case is the central pore hydrated and thus conductive. Interestingly, when N676 rotates toward the linker, we observe hydration of four so far unreported small nonpolar cavities. Based on these findings, we propose a model for TRPV1 gating involving the dynamic hydration of these four cavities. Free energy calculations indicate that this gating mechanisms is markedly temperature dependent favoring the open state at high temperature. On the basis of this model, which is able to rationalize a wealth of seemingly conflicting and/or unrelated experimental observations, we predicted the behavior of two single residue mutants, M572A and F580Y, the consequences of which we confirmed experimentally.
The interplay of demography and selection during maize domestication and expansion
Authors: Wang Li , Beissinger Timothy M. , Lorant Anne , Ross-Ibarra Claudia , Ross-Ibarra Jeffrey , Hufford Matthew B.
Published: March 2017

The history of maize has been characterized by major demographic events including changes in population size associated with domestication and range expansion as well as gene flow with wild relatives. The interplay between demographic history and selection has shaped diversity across maize populations and genomes. Here, we investigate these processes based on high-depth resequencing data from 31 maize landraces spanning the pre-Columbian distribution of maize as well as four wild progenitor individuals (Zea maysssp.parviglumis) from the Balsas River Valley in Mexico. Genome-wide demographic analyses reveal that maize domestication and spread resulted in pronounced declines in effective population size due to both a protracted bottleneck and serial founder effects, while, concurrently,parviglumisexperienced population growth. The cost of maize domestication and spread was an increase in deleterious alleles in the domesticate relative to its wild progenitor. This cost is particularly pronounced in Andean maize, which appears to have experienced a more dramatic founder event when compared to other maize populations. Introgression from the wild teosinteZea maysssp.mexicanainto maize in the highlands of Mexico and Guatemala is found found to decrease the prevalence of deleterious alleles, likely due to the higher long-term effective population size of wild maize. These findings underscore the strong interaction between historical demography and the efficiency of selection species- and genome-wide and suggest domesticated species with well-characterized histories may be particularly useful for understanding this interplay.
Coupling optogenetics and light-sheet microscopy, a method to study signal transductionin vivo
Authors: Kaur Prameet , Saunders Timothy E. , Tolwinski Nicholas S.
Published: March 2017

Optogenetics allows precise, fast and reversible intervention in biological processes. Light-sheet microscopy allows observation of the full course of embryonic development from egg to larva. Bringing the two approaches together allows unparalleled precision into the temporal regulation of signaling pathways and cellular processesin vivo. To develop this method, we investigated the regulation of canonical Wnt signaling during anterior-posterior patterning of theDrosophilaembryonic epidermis. Cryptochrome 2 (CRY2) fromArabidopsis Thalianawas fused to mCherry fluorescent protein andDrosophilaβ–catenin to form an easy to visualize optogenetic switch. Blue light illumination caused oligomerization of the fusion protein and inhibited downstream Wnt signalingin vitroandin vivo. Temporal inactivation of β–catenin confirmed that Wnt signaling is required not only forDrosophilapattern formation, but also for maintenance later in development. We anticipate that this method will be easily extendable to other developmental signaling pathways and many other experimental systems.
Genetic and epigenetic profiling of a solitary Peutz–Jeghers colon polyp
Authors: Linhart Heinz , Bormann Felix , Hutter Barbara , Brors Benedikt , Lyko Frank
Published: March 2017

Colon polyps represent precursor lesions of colon cancers and their malignant potential varies according to histological subtype. A rare subtype of colon polyps is the Peutz–Jeghers (PJ) polyp. PJ polyps mostly occur in the context of Peutz–Jeghers syndrome, which is characterized by the development of multiple polyps in the intestinal tract and hyperpigmentation of oral mucosa and lips. Peutz–Jeghers is an autosomal dominant disorder caused by pathogenic variants of the serine threonine kinase STK11. PJ polyps very rarely occur outside of the syndrome and are then referred to as solitary PJ polyps. Contrary to the situation in Peutz–Jeghers, the genetic basis and the malignant potential of solitary PJ polyps are currently unknown. Here we describe a detailed and comprehensive genetic profile of a solitary PJ polyp. Pathological examination revealed a high tissue homogeneity with >80% epithelial cells. Whole-genome sequencing failed to identify any clonal mutations but demonstrated a significant number of subclonal mutations. No somatic or germline mutations were found at the STK11 locus, suggesting that solitary PJ polyps are genetically distinct from Peutz–Jeghers polyps. In addition, methylome analysis revealed global hypomethylation and CpG island hypermethylation, two features that have been described as hallmarks of the colorectal cancer epigenome. These results provide an example of a premalignant lesion that is defined by epigenetic, rather than genetic changes. Furthermore, our findings support the notion that solitary PJ polyps constitute neoplastic tissue with malignant potential that should be removed for cancer prevention.
Acemetacin cocrystal structures by powder X-ray diffraction
Authors: Bolla Geetha , Chernyshev Vladimir , Nangia Ashwini
Published: March 2017

Cocrystals of acemetacin drug (ACM) with nicotinamide (NAM),p-aminobenzoic acid (PABA), valerolactam (VLM) and 2-pyridone (2HP) were prepared by melt crystallization and their X-ray crystal structures determined by high-resolution powder X-ray diffraction. The powerful technique of structure determination from powder data (SDPD) provided details of molecular packing and hydrogen bonding in pharmaceutical cocrystals of acemetacin. ACM–NAM occurs in anhydrate and hydrate forms, whereas the other structures crystallized in a single crystalline form. The carboxylic acid group of ACM forms theacid–amide dimer three-point synthonR32(9)R22(8)R32(9) with three differentsynamides (VLM, 2HP and caprolactam). The conformations of the ACM molecule observed in the crystal structures differ mainly in the mutual orientation of chlorobenzene fragment and the neighboring methyl group, beinganti(type I) orsyn(type II). ACM hydrate, ACM—NAM, ACM–NAM-hydrate and the piperazine salt of ACM exhibit the type I conformation, whereas ACM polymorphs and other cocrystals adopt the ACM type II conformation. Hydrogen-bond interactions in all the crystal structures were quantified by calculating their molecular electrostatic potential (MEP) surfaces. Hirshfeld surface analysis of the cocrystal surfaces shows that about 50% of the contribution is due to a combination of strong and weak O...H, N...H, Cl...H and C...H interactions. The physicochemical properties of these cocrystals are under study.
Foresight for E-paper development in Taiwan
Authors: Hsieh Chih-Hung , Lin Chien-Huei , Huang Jia-Ling
Published: March 2017

Purpose

This study aims to analyse the impact of e-paper on many existing industries including paper, publishing, book distribution, display, handheld device manufacturers and content service providers. Flexible display has been studied by many institutes, firms and market research companies. Some believe that e-paper is an exceptional application for flexible display, and the need for flexible display development for handheld devices and cloud-based e-book content is indisputable.

Design/methodology/approach

This study uses the Delphi technique and STEEP (Sociological, Technological, Economic, Environmental and Political aspects) with a panel to analyse a business model and the opportunity for the development of e-paper in Taiwan up to the year 2020.

Findings

The study concludes that e-paper content and customised digital services are an essential part of e-paper development, while hardware and cloud data are no more than a mechanism to show, compute and store data. Thus, whether the screen of a handheld device is flexible may not be of importance. Although e-paper will affect the display industry, it will not substitute for handheld devices and traditional bookstores.

Originality/value

This research can be used as a reference for government, academics, industry and international investors.
An analysis on the causal relationship between freight rate and newbuilding orders
Authors: Kim Chi Yeol , Park KwangSo
Published: March 2017

Purpose

The purpose of this paper is to provide implications for forecasting export of Korean shipbuilding industry that is suffering from deadlock in newbuilding orders, by investigating the causal relationship between freight rate earnings and newbuilding orders in the shipbuilding market.

Design/methodology/approach

Using a sample of freight rate earnings and newbuilding orders (in various terms) over the period 1996-2016, Granger causality between the two variables are examined in a vector autoregressive (VAR) model. In addition, the potential asymmetry of the causal relationship according to bullish and bearish market conditions is also investigated using a combination of moving averages of different time spans.

Findings

The results indicate a uni-directional causality running from freight rate earnings to newbuilding orders. This finding implies that shipowners’ confidence in the shipping freight market is particularly important determinants in their newbuilding investment, which is consistent with the overconfidence hypothesis. However, the causality does not vary according to different market conditions.

Research limitations/implications

This study offers several importation contributions. First, the authors provide evidence that newbuilding orders are positively associated with increase in freight rate earnings. Second, the authors document a causality running from changes in freight rate earnings to the volume of newbuilding orders. These findings support the theoretical expectation of the overconfidence hypothesis. Third, contrary to the findings in the financial market, there is no asymmetric response of the volume of newbuilding orders in bullish and bearish markets. Fourth, this study provide implications for management of Korean shipyards by providing evidence on driving force of newbuilding investment decisions of their customers (shipowners).

Practical implications

The findings in this study suggest implications for management of Korean shipyards by providing evidence on driving force of newbuilding investment decisions of their customers, as well as determinants of shipbuilding export, an important source of Korea’ national income.

Social implications

The analysing the major determinants of shipbuilding exports, the findings in this study presents understanding of market cycles in shipbuilding, an important source of Korea’s national income and balance of payment.

Originality/value

This study is the first attempt to analyse the relationship between freight rate earnings and newbuilding investment in the context of the behavioural theory in economics.
The effects of applying alternative discounting methods on the economic feasibility test of Free Trade Zone development project
Authors: Kyum Kim Sang
Published: March 2017

Purpose

The purpose of this paper is to examine the applicability of the alternative way of discounting, such as the hyperbolic discount method, for the economic feasibility test on Free Trade Zone development project that needs intergenerational analysis.

Design/methodology/approach

To analyze the effects of applying alternative discounting method in the cost-benefit analysis, this paper uses the hyperbolic discount method and HM-Treasury’s method (Britain), as well as the traditional exponential discount method. Also, this study uses benefit and cost data from the actual feasibility test of the Free Trade Zone development project in Korea, to obtain better policy implication.

Findings

For the case of long-term analysis, using the exponential discounting method in the benefit-cost analysis could not give us balanced analytic results, because it discounts too much on future generation’s benefits. In contrast, if we use the hyperbolic discounting method, we could obtain better balanced results since it can control the generational effects. This paper also finds that for the results to be valid, the analysis period must be expanded long enough (a minimum of 100 years).

Originality/value

The major findings of this paper confirm the results of previous studies regarding long-term benefit-cost analysis. Also, the result of this paper is properly compatible with the findings of behavioral economics, such as the time inconsistency of preferences. However, no research has been done with the proper length of analytic periods for using hyperbolic discounting yet. To examine this matter, this paper performs benefit-cost analysis with actual data from the feasibility studies in Korea. To the best of the author’s knowledge, this is the first study to find the proper length of analytic periods that can be compatible with the hyperbolic discount method.
Sentiment analysis of virtual brand communities for effective tribal marketing
Authors: Pathak Xema , Pathak-Shelat Manisha
Published: March 2017

Purpose

By doing sentiment analysis of netnographic data, this study aims to explain the need to give special attention to negative sentiments expressed in virtual tribes, as they play a significant role in translating the informational mode of conversation to the relational mode of conversation. The overall purpose is to aid brand managers in the process of brand co-creation by articulating brand communication targeted to specific audiences based on their shared passions and interests.

Design/methodology/approach

The study adopts a mixed-methods approach. The primary data were collected from two virtual brand communities through qualitative net-based ethnographic methods. Semantria Excel plug-in was used to categorize the extracted consumer statements based on positive, neutral and negative sentiments.

Findings

Managing the negative interactions in the virtual communities and relationship development with members through non-commercial conversations should be the two main priorities for effective brand management. Sentiment analysis specifically helps to identify pain points and consumer sentiments at each stage of the shopper journey. The findings of the study endorse the importance of offering and supporting communities as a valid marketing.

Research limitations/implications

This paper shows how systematic attention to user interactions on virtual brand communities can be used for tribal marketing, which in turn will impact the intangible aspects of the business, such as increasing brand value and loyalty. By engaging the consumers, the social ties among the target audience can be nurtured and strengthened.

Originality/value

This paper focuses on decoding their behavior by unpeeling the consumer statements rather than tangible aspects of the business, such as sales of products or services. It contributes to development of a theoretical framework that outlines how the interactions in virtual brand communities can aid in formulating the functional and communicational strategies for a brand.
Harvesting wildlife affected by climate change: a modelling and management approach for polar bears
Authors: Regehr Eric V. , Wilson Ryan R. , Rode Karyn D. , Runge Michael C. , Stern Harry L.
Published: March 2017

The conservation of many wildlife species requires understanding the demographic effects of climate change, including interactions between climate change and harvest, which can provide cultural, nutritional or economic value to humans.

We present a demographic model that is based on the polar bearUrsus maritimuslife cycle and includes density‐dependent relationships linking vital rates to environmental carrying capacity (K). Using this model, we develop a state‐dependent management framework to calculate a harvest level that (i) maintains a population above its maximum net productivity level (MNPL; the population size that produces the greatest net increment in abundance) relative to a changingK, and (ii) has a limited negative effect on population persistence.

Our density‐dependent relationships suggest thatMNPLfor polar bears occurs at approximately 0·69 (95%CI = 0·63–0·74) ofK. Population growth rate atMNPLwas approximately 0·82 (95%CI = 0·79–0·84) of the maximum intrinsic growth rate, suggesting relatively strong compensation for human‐caused mortality.

Our findings indicate that it is possible to minimize the demographic risks of harvest under climate change, including the risk that harvest will accelerate population declines driven by loss of the polar bear's sea‐ice habitat. This requires that (i) the harvest rate – which could be 0 in some situations – accounts for a population's intrinsic growth rate, (ii) the harvest rate accounts for the quality of population data (e.g. lower harvest when uncertainty is large), and (iii) the harvest level is obtained by multiplying the harvest rate by an updated estimate of population size. Environmental variability, the sex and age of removed animals and risk tolerance can also affect the harvest rate.

Synthesis and applications. We present a coupled modelling and management approach for wildlife that accounts for climate change and can be used to balance trade‐offs among multiple conservation goals. In our example application to polar bears experiencing sea‐ice loss, the goals are to maintain population viability while providing continued opportunities for subsistence harvest. Our approach may be relevant to other species for which near‐term management is focused on human factors that directly influence population dynamics within the broader context of climate‐induced habitat degradation.
Climate, soil and plant functional types as drivers of global fine‐root trait variation
Authors: Freschet Grégoire T. , Valverde‐Barrantes Oscar J. , Tucker Caroline M. , Craine Joseph M. , McCormack M. Luke , Violle Cyrille , Fort Florian , Blackwood Christopher B. , Urban‐Mead Katherine R. , Iversen Colleen M. , Bonis Anne , Comas Louise H. , Cornelissen Johannes H. C. , Dong Ming , Guo Dali , Hobbie Sarah E. , Holdaway Robert J. , Kembel Steven W. , Makita Naoki , Onipchenko Vladimir G. , Picon‐Cochard Catherine , Reich Peter B. , de la Riva Enrique G. , Smith Stuart W. , Soudzilovskaia Nadejda A. , Tjoelker Mark G. , Wardle David A. , Roumet Catherine
Published: March 2017

Ecosystem functioning relies heavily on below‐ground processes, which are largely regulated by plant fine‐roots and their functional traits. However, our knowledge of fine‐root trait distribution relies to date on local‐ and regional‐scale studies with limited numbers of species, growth forms and environmental variation.

We compiled a world‐wide fine‐root trait dataset, featuring 1115 species from contrasting climatic areas, phylogeny and growth forms to test a series of hypotheses pertaining to the influence of plant functional types, soil and climate variables, and the degree of manipulation of plant growing conditions on species fine‐root trait variation. Most particularly, we tested the competing hypotheses that fine‐root traits typical of faster return on investment would be most strongly associated with conditions of limiting versus favourable soil resource availability. We accounted for both data source and species phylogenetic relatedness.

We demonstrate that: (i) Climate conditions promoting soil fertility relate negatively to fine‐root traits favouring fast soil resource acquisition, with a particularly strong positive effect of temperature on fine‐root diameter and negative effect on specific root length (SRL), and a negative effect of rainfall on root nitrogen concentration; (ii) Soil bulk density strongly influences species fine‐root morphology, by favouring thicker, denser fine‐roots; (iii) Fine‐roots from herbaceous species are on average finer and have higher SRL than those of woody species, and N2‐fixing capacity positively relates to root nitrogen; and (iv) Plants growing in pots have higher SRL than those grown in the field.

Synthesis. This study reveals both the large variation in fine‐root traits encountered globally and the relevance of several key plant functional types and soil and climate variables for explaining a substantial part of this variation. Climate, particularly temperature, and plant functional types were the two strongest predictors of fine‐root trait variation. High trait variation occurred at local scales, suggesting that wide‐ranging below‐ground resource economics strategies are viable within most climatic areas and soil conditions.
Soil carbon response to woody plant encroachment: importance of spatial heterogeneity and deep soil storage
Authors: Zhou Yong , Boutton Thomas W. , Wu X. Ben
Published: March 2017

Recent global trends of increasing woody plant abundance in grass‐dominated ecosystems may substantially enhance soil organic carbon (SOC) storage and could represent a strong carbon (C) sink in the terrestrial environment. However, few studies have quantitatively addressed the influence of spatial heterogeneity of vegetation and soil properties on SOC storage at the landscape scale. In addition, most studies assessing SOC response to woody encroachment consider only surface soils, and have not explicitly assessed the extent to which deeper portions of the soil profile may be sequestering C.

We quantified the direction, magnitude and pattern of spatial heterogeneity of SOC in the upper 1·2 m of the profile following woody encroachment via spatially specific intensive soil sampling across a landscape in a subtropical savanna in the Rio Grande Plains, USA, that has undergone woody proliferation during the past century.

Increased SOC accumulation following woody encroachment was observed to considerable depth, albeit at reduced magnitudes in deeper portions of the profile. Overall, woody clusters and groves accumulated 12·87 and 18·67 Mg C ha−1 more SOC compared to grasslands to a depth of 1·2 m.

Woody encroachment significantly altered the pattern of spatial heterogeneity of SOC to a depth of 5 cm, with marginal effect at 5–15 cm, and no significant impact on soils below 15 cm. Fine root density explained greater variability of SOC in the upper 15 cm, while a combination of fine root density and soil clay content accounted for more of the variation in SOC in soils below 15 cm across this landscape.

Synthesis. Substantial soil organic carbon sequestration can occur in deeper portions of the soil profile following woody encroachment. Furthermore, vegetation patterns and soil properties influenced the spatial heterogeneity and uncertainty of soil organic carbon in this landscape, highlighting the need for spatially specific sampling that can characterize this variability and enable scaling and modelling. Given the geographic extent of woody encroachment on a global scale, this undocumented deep soil carbon sequestration suggests this vegetation change may play a more significant role in regional and global carbon sequestration than previously thought.
Gastric cancer management: Kinases as a target therapy
Authors: Farran Batoul , Müller Susanne , Montenegro Raquel C
Published: March 2017

The molecular diagnostics revolution has reshaped the practice of oncology by facilitating the identification of genetic, epigenetic and proteomic modifications correlated with cancer, thus delineating ‘oncomaps’ for various cancer types. These advances have enhanced our understanding of gastric cancer, one of the most fatal diseases worldwide, and culminated in the approval of novel molecular therapies such as trastuzumab. Gastric tumours display recurrent aberrations in key kinase oncogenes such as Her2, epidermal growth factor receptor (EGFR), PI3K, mTOR or c‐Met, suggesting that these receptors are amenable to inhibition using specific drug agents. In this review, we examine the mutational landscape of gastric cancer, the use of kinase inhibitors as targeted therapies in gastric tumours and the clinical trials underway for novel inhibitors, highlighting successes, failures and future directions.
The limits of intensive feeding: maternal foodwork at the intersections of race, class, and gender
Authors: Brenton Joslyn
Published: March 2017

Despite experiencing numerous barriers, mothers today confront increasing social pressure to embody perfection through their foodwork. A growing body of social science research identifies how gender and class inequality shape women's perceptions of food and their feeding strategies, but this research is thus far limited in its understanding of the roles that race and ethnic identity play in a mother's food landscape. Drawing on 60 in‐depth interviews with a racially and economically diverse group of mothers, this paper examines how feeding young children is intertwined with contemporary ideas about child health as well as women's efforts to negotiate race, class, and gender hierarchies. Extending Hays' concept of intensive mothering, rich descriptions of feeding children reveal how mothers in this study are discursively engaged with what I call an ‘intensive feeding ideology’ – the widespread belief that good mothering is synonymous with intensive food labour. Drawing on intersectional theory, this article discusses the limits of an intensive feeding ideology, particularly for poor and middle‐class mothers of colour. The findings contribute to an understanding of how power relations are embedded within food ideologies and how mothers of young children attempt to negotiate them.
Can earlier literacy skills have a negative impact on future home literacy activities? Evidence from Japanese
Authors: Inoue Tomohiro , Georgiou George K. , Muroya Naoko , Maekawa Hisao , Parrila Rauno
Published: March 2017

We examined the cross‐lagged relations between the home literacy environment and literacy skills in Japanese, and whether child's gender, parents' education and child's level of literacy performance moderate the relations. One hundred forty‐two Japanese children were followed from Grades 1 to 2 and assessed on character knowledge, reading fluency and spelling. Their parents responded to a questionnaire assessing the frequency of their teaching and shared reading. Results showed that parent teaching increased and shared reading decreased from Grades 1 to 2. Cross‐lagged path analysis indicated that the literacy skills in Grade 1 were negatively associated with parent teaching in Grade 2. The results further suggested that more educated parents of higher performing children, particularly boys, adjusted their involvement to their children's literacy skills, while less educated parents of lower performing children did not. These findings indicate the importance of parents' sensitivity to their child's performance.

What is already known about this topic

Home literacy environment (HLE) plays an important role in children's literacy acquisition in Western and some East Asian contexts.

Children's early reading skills can have an impact on later HLE.

The direction of the relationship between HLE and children's reading skills may change from positive in Kindergarten to negative in Grade 1.

What this paper adds

In line with the findings of previous studies in other languages, Japanese parents adaptively adjust their home literacy activities to their child's literacy skills.

The effect of children's literacy skills on later shared reading is stronger among boys than among girls.

More educated parents of higher performing children adjust their involvement to their child's literacy skills, while less educated parents with lower performing children do not.

Implications for theory, policy or practice

We should encourage parents to be sensitive to their child's literacy skills to help them build a foundation that will boost future literacy development.

This can be particularly true of less educated parents with poorly performing children.

We should encourage educators to communicate the children's literacy achievement to their parents and also suggest the means by which HLE could be beneficial for their children's literacy development.
‘Hidden’ expatriates: international mobility in the United Arab Emirates as a challenge to current understanding of expatriation
Authors: Haak‐Saheem Washika , Brewster Chris
Published: March 2017

Expatriates are often assumed to have enhanced terms and conditions and, because that makes them expensive, to be in key managerial or technical specialist roles. Employees who come from abroad and are in more manual or even menial roles are usually referred to as ‘migrants’. However, there are millions of people around the world who are not migrants, their intended sojourn in a foreign country is seen by them and their employers as temporary, but their employment contracts are far from advantageous compared with those of locals. These ‘hidden’ expatriates are brought into focus in the emerging Arab Gulf States. In some of these countries, the population consists mainly of expatriates, with the local population a small minority: These expatriates include many in lower‐management or manual or menial jobs. We demarcate these expatriates from organisationally assigned expatriates, self‐initiated expatriates and migrants. We use qualitative data from such expatriates in the United Arab Emirates to explore the issues this raises for governments, employers and the expatriates – and for our understanding of the phenomenon of expatriation.
Thyme Oil Encapsulated in Halloysite Nanotubes for Antimicrobial Packaging System
Authors: Lee Min Hyeock , Seo Hyun‐Sun , Park Hyun Jin
Published: March 2017

An antimicrobial capsule releasing thyme oil was developed using modified halloysite nanotubes (HNTs). In order to increase the pore volume, HNTs were treated with 5.0 mol/L NaOH solution, which resulted in the encapsulation of more thyme oil molecules inside the HNTs. The morphology of the raw HNTs and NaOH‐treated HNTs (N‐HNTs) was characterized using transmission electron microscopy and nitrogen adsorption‐desorption analysis. The loading capacity increased from 180.7 ± 12.7 to 256.4 ± 16.7 mg thyme oil/g HNT after the NaOH treatment. The aerial release characteristics of thyme oil from both the HNT capsules were investigated in a closed‐package atmosphere system at 4, 25, and 40 °C. The antimicrobial activity of the capsule against Escherichia coli O157:H7 was determined using the vapor phase assay. Moreover, the antimicrobial effects of the capsule against E. coli O157:H7, total mesophilic aerobic bacteria (MAB), and molds and yeasts (MY) on the surfaces of cherry tomatoes were investigated at 4 and 25 °C for 5 d. When the cherry tomatoes were exposed to the thyme oil‐loaded N‐HNT capsule, the number of E. coli O157:H7, MAB, and MY significantly reduced during storage.