bluuebunny/crossref_metadata_2025 huggingface dataset:
Gamete compatibility genes in mammals: candidates, applications and a potential path forward
Authors: Springate Leah , Frasier Timothy R.
Published: August 2017

Fertilization represents a critical stage in biology, where successful alleles of a previous generation are shuffled into new arrangements and subjected to the forces of selection in the next generation. Although much research has been conducted on how variation in morphological and behavioural traits lead to variation in fertilization patterns, surprisingly little is known about fertilization at a molecular level, and specifically about how genes expressed on the sperm and egg themselves influence fertilization patterns. In mammals, several genes have been identified whose products are expressed on either the sperm or the egg, and which influence the fertilization process, but the specific mechanisms are not yet known. Additionally, in 2014 an interacting pair of proteins was identified: ‘Izumo’ on the sperm, and ‘Juno’ on the egg. With the identification of these genes comes the first opportunity to understand the molecular aspects of fertilization in mammals, and to identify how the genetic characteristics of these genes influence fertilization patterns. Here, we review recent progress in our understanding of fertilization and gamete compatibility in mammals, which should provide a helpful guide to researchers interested in untangling the molecular mechanisms of fertilization and the resulting impacts on population biology and evolutionary processes.
Polarized light use in the nocturnal bull ant,Myrmecia midas
Authors: Freas Cody A. , Narendra Ajay , Lemesle Corentin , Cheng Ken
Published: August 2017

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant,Myrmecia midas. We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1−2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts.
Investigating the impact of feedback update interval on the efficacy of restorative brain–computer interfaces
Authors: Darvishi Sam , Ridding Michael C. , Hordacre Brenton , Abbott Derek , Baumert Mathias
Published: August 2017

Restorative brain–computer interfaces (BCIs) have been proposed to enhance stroke rehabilitation. Restorative BCIs are able to close the sensorimotor loop by rewarding motor imagery (MI) with sensory feedback. Despite the promising results from early studies, reaching clinically significant outcomes in a timely fashion is yet to be achieved. This lack of efficacy may be due to suboptimal feedback provision. To the best of our knowledge, the optimal feedback update interval (FUI) during MI remains unexplored. There is evidence that sensory feedback disinhibits the motor cortex. Thus, in this study, we explore how shorter than usual FUIs affect behavioural and neurophysiological measures following BCI training for stroke patients using a single-case proof-of-principle study design. The action research arm test was used as the primary behavioural measure and showed a clinically significant increase (36%) over the course of training. The neurophysiological measures including motor evoked potentials and maximum voluntary contraction showed distinctive changes in early and late phases of BCI training. Thus, this preliminary study may pave the way for running larger studies to further investigate the effect of FUI magnitude on the efficacy of restorative BCIs. It may also elucidate the role of early and late phases of motor learning along the course of BCI training.
Thermal facial reactivity patterns predict social categorization bias triggered by unconscious and conscious emotional stimuli
Authors: Ponsi Giorgia , Panasiti Maria Serena , Rizza Giulia , Aglioti Salvatore Maria
Published: August 2017

Members of highly social species decode, interpret, and react to the emotion of a conspecific depending on whether the other belongs to the same (ingroup) or different (outgroup) social group. While studies indicate that consciously perceived emotional stimuli drive social categorization, information about how implicit emotional stimuli and specific physiological signatures affect social categorization is lacking. We addressed this issue by exploring whether subliminal and supraliminal affective priming can influence the categorization of neutral faces as ingroup versus outgroup. Functional infrared thermal imaging was used to investigate whether the effect of affective priming on the categorization decision was moderated by the activation of the sympathetic nervous system (SNS). During the subliminal condition, we found that stronger SNS activation after positive or negative affective primes induced ingroup and outgroup face categorization, respectively. The exact opposite pattern (i.e. outgroup after positive and ingroup after negative primes) was observed in the supraliminal condition. We also found that misattribution effects were stronger in people with low emotional awareness, suggesting that this trait moderates how one recognizes SNS signals and employs them for unrelated decisions. Our results allow the remarkable implication that low-level affective reactions coupled with sympathetic activation may bias social categorization.
Estimating parasite host range
Authors: Dallas Tad , Huang Shan , Nunn Charles , Park Andrew W. , Drake John M.
Published: August 2017

Estimating the number of host species that a parasite can infect (i.e. host range) provides key insights into the evolution of host specialism and is a central concept in disease ecology. Host range is rarely estimated in real systems, however, because variation in species relative abundance and the detection of rare species makes it challenging to confidently estimate host range. We applied a non-parametric richness indicator to estimate host range in simulated and empirical data, allowing us to assess the influence of sampling heterogeneity and data completeness. After validating our method on simulated data, we estimated parasite host range for a sparsely sampled global parasite occurrence database (Global Mammal Parasite Database) and a repeatedly sampled set of parasites of small mammals from New Mexico (Sevilleta Long Term Ecological Research Program). Estimation accuracy varied strongly with parasite taxonomy, number of parasite occurrence records, and the shape of host species-abundance distribution (i.e. the dominance and rareness of species in the host community). Our findings suggest that between 20% and 40% of parasite host ranges are currently unknown, highlighting a major gap in our understanding of parasite specificity, host–parasite network structure, and parasite burdens.
Body size affects the evolution of hidden colour signals in moths
Authors: Kang Changku , Zahiri Reza , Sherratt Thomas N.
Published: August 2017

Many cryptic prey have also evolved hidden contrasting colour signals which are displayed to would-be predators. Given that these hidden contrasting signals may confer additional survival benefits to the prey by startling/intimidating predators, it is unclear why they have evolved in some species, but not in others. Here, we have conducted a comparative phylogenetic analysis of the evolution of colour traits in the family Erebidae (Lepidoptera), and found that the hidden contrasting colour signals are more likely to be found in larger species. To understand why this relationship occurs, we present a general mathematical model, demonstrating that selection for a secondary defence such as deimatic display will be stronger in large species when (i) the primary defence (crypsis) is likely to fail as its body size increases and/or (ii) the secondary defence is more effective in large prey. To test the model assumptions, we conducted behavioural experiments using a robotic moth which revealed that survivorship advantages were higher against wild birds when the moth has contrasting hindwings and large size. Collectively, our results suggest that the evolutionary association between large size and hidden contrasting signals has been driven by a combination of the need for a back-up defence and its efficacy.
Experience matters: context-dependent decisions explain spatial foraging patterns in the deposit-feeding crabScopimera intermedia
Authors: Hui T. Y. , Williams Gray A.
Published: August 2017

Behavioural decisions are often context-dependent, where information from immediate experience is incorporated into an individual's decision-making, particularly in complex environments. To test whether such mechanism is adopted by foragers in heterogeneous environments, we investigated the foraging behaviour of the deposit-feeding sand-bubbler crab,Scopimera intermedia. An individual-based model was constructed, based on an optimal-patch selection criterion, which implicitly assumed that individuals adjust foraging decisions based on immediate past experience. The model's predictions were tested on the shore by manipulating the location of food patches, where the crab showed a strong context-dependent foraging pattern. When resources were randomly distributed, the crab responded by spending 56% of time in enriched patches compared with only 28% in the same area when patches were composed of natural sediments. Shore manipulations varying resource distribution supported the underlying principles of the model mechanism, and highlighted the benefits of such a strategy in heterogeneous environments such as intertidal sediments where food resources vary at different spatial and temporal scales. The proposed model therefore provides a mechanistic process, based on optimal foraging, to predict foraging decisions and movement patterns of animals feeding in heterogeneous landscapes.
Vegetative compatibility groups explain variation in the virulence ofVerticillium dahliaeon strawberry
Authors: Fan Rong , Cockerton Helen , Armitage Andrew D. , Bates Helen , Cascant-Lopez Emma , Antanaviciute Laima , Xu Xiangming , Hu Xiaoping , Harrison Richard J.
Published: August 2017

Verticillium dahliaeinfection of strawberry (Fragaria × ananassa) is a major cause of disease-induced wilting in soil-grown strawberries across the world. To understand what components of the pathogen are affecting disease expression, the presence of the known effectorVdAve1was screened in a sample ofVerticillium dahliaeisolates. Isolates from strawberry were found to containVdAve1and were divided into two major clades, based upon their vegetative compatibility groups (VCG); no UK strawberry isolates containedVdAve1. VC clade was strongly related to their virulence levels.VdAve1-containing isolates pathogenic on strawberry were found in both clades, in contrast to some recently published findings.

On strawberry,VdAve1-containing isolates had significantly higher virulence during early infection, which diminished in significance as the infection progressed. Transformation of a virulent non-VdAve1containing isolate, withVdAve1was found neither to increase nor decrease virulence when inoculated on a susceptible strawberry cultivar. There are therefore virulence factors that are epistatic toVdAve1and potentially multiple independent routes to high virulence on strawberry inV. dahliaelineages.

Genome sequencing a subset of isolates across the two VCGs revealed that isolates were differentiated at the whole genome level and contained multiple changes in putative effector content, indicating that different clonal VCGs may have evolved different strategies for infecting strawberry, leading to different virulence levels in pathogenicity tests. It is therefore important to consider both clonal lineage and effector complement as the adaptive potential of each lineage will differ, even if they contain the same race determining effector.
A Portable Software Library that Implements the Gillespie Direct Method
Authors: Sauro Herbert M
Published: August 2017

A common approach to simulating chemical reaction systems is to formulate the problem as a set of ordinary differential equation and solve them using standard numerical procedures. Such a formulation works well when the number of molecules involved in the simulation is large and assumes a deterministic formulation for the underling chemical kinetics. However for systems such as gene regulatory networks where the number of molecules of a specific species can be of the order of 10s of molecules, the deterministic approach fails to capture important dynamical features. At low molecular numbers stochastic events dominate the dynamics. As a result much research has been devoted to developing numerical algorithms for computing the stochastic trajectories. One of the most common approaches is based on Gillespie’s stochastic simulation algorithm, for example the direct method. Due to its simplicity the direct method has been implemented many times in software. However, unusually, there does not appear to be a C based reusable software library. This article describes the development of such a library. All source code is licensed under the liberal Apache 2.0 open source license and is available at Github:https://github.com/sys-bio/libStochastic
ACaenorhabditis elegansmodel of adenylosuccinate lyase deficiency reveals neuromuscular and reproductive phenotypes of distinct etiology
Authors: Fenton Adam R. , Janowitz Haley N. , McReynolds Melanie R. , Wang Wenqing , Hanna-Rose Wendy
Published: August 2017

Inborn errors of purine metabolism are rare syndromes with an array of complex phenotypes in humans. One such disorder, adenylosuccinate lyase deficiency (ASLD), is caused by a decrease in the activity of the bi-functional purine biosynthetic enzyme, adenylosuccinate lyase (ADSL). Mutations in human ADSL cause epilepsy, muscle ataxia, and autistic-like symptoms. Although the genetic basis of ASLD syndrome is known, the molecular mechanisms driving phenotypic outcome are not. Here, we characterize neuromuscular and reproductive phenotypes associated with a deficiency ofadsl-1inCaenorhabditis elegans.Characterization of the neuromuscular phenotype reveals a disruption of cholinergic transmission affecting muscular contraction. Using genetics, pharmacological supplementation, and metabolite measurements, we correlate phenotypes with distinct metabolic perturbations. The neuromuscular defect is associated with a toxic accumulation of a purine biosynthetic intermediate whereas the reproductive defect can be ameliorated by purine supplementation, indicating differing molecular mechanisms behind the phenotypes of ASLD. Because purine metabolism is highly conserved in metazoans, we suggest that similar separable metabolic perturbations result in the varied symptoms in the human disorder and that a dual-approach therapeutic strategy may be beneficial.
Anaerobic methanotrophic communities thrive in deep submarine permafrost
Authors: Winkel Matthias , Mitzscherling Julia , Overduin Pier P. , Horn Fabian , Winterfeld Maria , Rijkers Ruud , Grigoriev Mikhail N. , Knoblauch Christian , Mangelsdorf Kai , Wagner Dirk , Liebner Susanne
Published: August 2017

Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic (ANME-2a/b, ANME-2d) assemblages in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in AOM we found a large diversity of archaea mainly belonging toBathyarchaeota,Thaumarchaeota, andEuryarchaeota. Methane concentrations and δ13C-methane signatures distinguish horizons of potential anaerobic oxidation of methane (AOM) coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescencein situhybridization (FISH) corroborate AOM communities in submarine permafrost sediments potentially active at low temperatures. Extrapolating potential AOM rates, when scaled to the total area of expected submarine permafrost thaw, reveals that methane could be consumed at rates between 8 and 120 Tg C per year, which is comparable to other AOM habitats such as seeps, continental SMTZ and wetlands. We thus propose that AOM is active where submarine permafrost thaws and needs to be accounted for in global methane budgets.
A high-throughput analysis method of microdroplet PCR coupled with fluorescence spectrophotometry
Authors: Du Yanan , Zhao Xiao , Zhao Binan , Xu Yan , Shi Wei , Ren Fangfang , Wu Yangyang , Hu Ruili , Fan Xiaorui , Zhang Qi , Zhang Xiaoxia , Shi Bin , Zhao Huanzhen , Zhao Kai
Published: August 2017

Here we report a novel microdroplet PCR method combined with fluorescence spectrophotometry (MPFS), which allows for qualitative, quantitative and high -throughput detection of multiple DNA targets. In this study, each pair of primers was labeled with a specific fluorophore. Through microdroplet PCR, a target DNA was amplified and labeled with the same fluorophore. After products purification, the DNA products tagged with different fluorophores could be analyzed qualitatively by the fluorescent intensity determination. The relative fluorensence unit was also measured to construct the standard curve and to achieve quantitative analysis. In a reaction, the co -amplified products with different fluorophores could be simultaneously analyzed to achieve high -throughput detection. We used four kinds of GM maize as a model to confirm this theory. The qualitative results revealed high specificity and sensitivity of 0.5% (w / w). The quantitative results revealed that the limit of detection was 103copies and with good repeatability. Moreover, reproducibility assay were further performed using four foodborne pathogenic bacteria. Consequently, the same qualitative, quantitative and high-throughput results were confirmed as the four GM maize.
GVC: An ultra-fast and all-round genome variant caller
Authors: Zhang Zhongbo , Yin Longhui , Hao Lingtong , Cao Lihua , Liu Changlin , Chen Mengzhu , Li Cheng , Xu Zhao , Ling Shaoping
Published: August 2017

Genome variant detection is a challenge task in cancer genome analysis. Current software for variant detection is very time-consuming and in the same time not accurate enough to satisfy the requirements of clinical applications in precision oncology. We developed an all-round ultra-fast Genomic Variant Caller (GVC), which can detect Germline and Somatic variants, including SNVs and INDELs from genome sequencing data with super high speed and accuracy. GVC achieved mean F1-measure of 99.34% and 97.92% for Germline SNVs in WGS and WES datasets, respectively. And GVC reached mean F1-measure of 97.34% and 89.03% for Germline INDELs in WGS and WES datasets, respectively. GVC achieved mean F1-measure of 90.79% and 86.3% for Somatic SNVs in WGS and WES datasets, respectively. GVC reached mean F1-measure of 76.88% and 68.36% for Somatic INDELs in WGS and WES datasets, respectively. GVC outperformed all the other widely used pipelines. GVC showed super-fast processing speed, exhibiting 128-fold and 54-fold increase in comparison to GATK in WGS and WES datasets processing, respectively. GVC webtool is available from GVC Web Toolhttps://gvc.0cancer.cn. Basing on the accurate GVC algorithm, we also released tumor mutation burden (TMB) results of TCGA datasets on GVC Web Tool.
An individual differences approach to semantic cognition: Divergent effects of age on representation, retrieval and selection
Authors: Hoffman Paul
Published: August 2017

Semantic cognition refers to the appropriate use of acquired knowledge about the world. This requires representation of knowledge as well as control processes which ensure that currently-relevant aspects of knowledge are retrieved and selected. Although these abilities can be impaired selectively following brain damage, the relationship between them in healthy individuals is unclear. It is also commonly assumed that semantic cognition is preserved in later life, because older people have greater reserves of knowledge. However, this claim overlooks the possibility of decline in semantic control processes. Here, semantic cognition was assessed in 100 young and older adults. Despite having a broader knowledge base, older people showed specific impairments in semantic control, performing more poorly than young people when selecting among competing semantic representations. Conversely, they showed preserved controlled retrieval of less salient information from the semantic store. Breadth of semantic knowledge was positively correlated with controlled retrieval but was unrelated to semantic selection ability, which was instead correlated with non-semantic executive function. These findings indicate that three distinct elements contribute to semantic cognition: semantic representations that accumulate throughout the lifespan, processes for controlled retrieval of less salient semantic information, which appear age-invariant, and mechanisms for selecting task-relevant aspects of semantic knowledge, which decline with age and may relate more closely to domain-general executive control.
Tripolar mitosis drives the association between maternal genotypes ofPLK4and aneuploidy in human preimplantation embryos
Authors: McCoy Rajiv C. , Newnham Louise J. , Ottolini Christian S. , Hoffmann Eva R. , Chatzimeletiou Katerina , Cornejo Omar E. , Zhan Qiansheng , Zaninovic Nikica , Rosenwaks Zev , Petrov Dmitri A. , Demko Zachary P. , Sigurjonsson Styrmir , Handyside Alan H.
Published: August 2017

Aneuploidy is prevalent in human preimplantation embryos and is the leading cause of pregnancy loss. Many aneuploidies arise during oogenesis, increasing in frequency with maternal age. Superimposed on these meiotic aneuploidies are a range of errors occurring during early mitotic divisions of the embryo, contributing to widespread chromosomal mosaicism. Here we reanalyzed a published dataset comprising preimplantation genetic testing for aneuploidy in 24,653 blastomere biopsies from day-3 cleavage-stage embryos, as well as 17,051 trophectoderm biopsies from day-5 blastocysts. We focused on complex abnormalities that affected multiple chromosomes simultaneously, seeking to quantify their incidences and gain insight into their mechanisms of formation. In addition to well-described patterns such as triploidy and haploidy, we identified 4.7% of day-3 blastomeres possessing karyotypes suggestive of tripolar mitosis in normally-fertilized diploid zygotes or descendant diploid cells. We further supported this hypothesis using time-lapse data from an intersecting set of 77 cleavage-stage embryos. The diploid tripolar signature was rare among day-5 blastocyst biopsies (0.5%), suggesting that complex aneuploidy generated by tripolar mitosis impairs cellular and/or early embryonic survival. Strikingly, we found that the tripolar mitosis mechanism is responsible for the previously described association with common maternal genetic variants spanningPLK4. Our findings are consistent with the role ofPLK4as the master regulator of centriole duplication with a known capacity to induce tripolar mitosis when mutated or mis-expressed. Taken together, we propose that tripolar mitosis is a key mechanism generating karyotype-wide aneuploidy in cleavage-stage embryos and implicatePLK4-mediated centrosome abnormality as a factor influencing its occurrence.
Demographic consequences of invasion by a native, controphic competitor to an insular bird population
Authors: Johnson Kate M. , Germain R.R. , Tarwater C.E. , Arcese Peter
Published: August 2017

Species invasions and range shifts can lead to novel competitive interactions between historically resident and colonizing species, but the demographic consequences of such interactions remain controversial. We present results from field experiments and 45 yrs of demographic monitoring to test the hypothesis that the colonization of Mandarte Is., BC, Canada, by fox sparrows (Passerella iliaca) caused the long-term decline of the song sparrow (Melospiza melodia) population resident there. Several lines of evidence indicate that competition with fox sparrows for winter food reduced over-winter survival in juvenile song sparrows, enforcing population decline despite an increase in annual reproductive rate in song sparrows over the same period. In contrast, we found no evidence of interspecific competition for resources during the breeding season. Our results indicate that in the absence of a sufficient ecological or evolutionary shift in niche dimension, range expansions by dominant competitors have the potential to cause the extirpation of historically resident species when competitive interactions between them are strong and resources not equitably partitioned.
A halide-free pyridinium-substituted η3-cycloheptatrienide–Pd complex
Authors: Jandl C. , Stegbauer S. , Pöthig A.
Published: August 2017

We report the synthesis and characterization of a novel 4-(dimethylamino)pyridinium-substituted η3-cycloheptatrienide–Pd complex which is free of halide ligands. Diacetonitrile{η3-[4-(dimethylamino)pyridinium-1-yl]cycloheptatrienido}palladium(II) bis(tetrafluoroborate), [Pd(C2H3N)2(C14H16N2)](BF4)2, was prepared by the exchange of two bromide ligands for noncoordinating anions, which results in the empty coordination sites being occupied by acetonitrile ligands. As described previously, exchange of only one bromide leads to a dimeric complex, di-μ-bromido-bis({η3-[4-(dimethylamino)pyridinium-1-yl]cycloheptatrienido}palladium(II)) bis(tetrafluoroborate) acetonitrile disolvate, [Pd2Br2(C14H16N2)2](BF4)2·2CH3CN, with bridging bromide ligands, and the crystal structure of this compound is also reported here. The structures of the cycloheptatrienide ligands of both complexes are analogous to the dibromide derivative, showing the allyl bond in the β-position with respect to the pyridinium substituent. This indicates that, unlike a previous interpretation, the main reason for the formation of the β-isomer cannot be internal hydrogen bonding between the cationic substituents and bromide ligands.
Mathematical model of energy conversion mechanism in screw centrifugal pump based on load criteria of blade airfoil
Authors: Quan Hui , Fu Baiheng , Li Rennian , Li Guangxian , Zhang Zhengjie , Li Jin
Published: August 2017

Purpose

To analyze the work principle and capacity of energy conversion in each segment of profile lines, the energy transfer from impeller to transmission medium is separated into head coefficient and load coefficient to analyze the energy transfer process. The concepts of airfoil lift coefficient and drag coefficient are used; the third manifestation of the Euler equations is used as well.

Design/methodology/approach

The numerical simulation of energy conversion mechanism based on load criteria of vane airfoil has been established in screw centrifugal pump to explain its energy conversion mechanism in an impeller. Upon this basis, the velocity and pressure along the entire blade are investigated through the numerical simulation of internal solid–liquid flow in the pump. The energy conversion process under load criteria in the blade airfoil has also been obtained.

Findings

The research suggests that the mathematical model of energy conversion mechanism based on the load criteria of the vane airfoil is reliable in the screw centrifugal pump. The screw centrifugal blade has twice or even several times the wrap angle than the ordinary centrifugal blade. It is a large wrap angle that forms the unique flow channel which lays the foundation for solid particles to pass smoothly and for soft energy conversion. At the same time, load distribution along the profile line on the long-screw centrifugal blade is an important factor affecting the energy conversion efficiency of the impeller.

Originality/value

The quantitative analysis method of energy in the screw centrifugal pump can help the pump designer improve certain features of the pump and shorten the research cycle.
Numerical simulation of the influence of particle shape on the mechanical properties of rockfill materials
Authors: Han Hongxing , Chen Wei , Huang Bin , Fu Xudong
Published: August 2017

Purpose

This paper aims to propose a shape factor for granular materials based on particle shape. The scientific goal is to investigate the influence of particle shape on the mechanical properties of rockfill materials.

Design/methodology/approach

The method of generating four regular-shaped particles is based on the observation that most rockfill grains are regarded as like-triangle, like-rhombus, like-square and like-hexagon. A shape factorFthat is developed using the Blaschke coefficient and a concave–convex degree is proposed. A biaxial compression test on rockfill materials under stress path is numerically simulated by discrete element method. The evolution of the shape factorFunder the simulated stress paths is analyzed, and particle breakage rate, peak intensity and peak-related internal friction angle for rockfill materials are derived. A method of determining the shape factorFinvolved in the two functions is proposed.

Findings

A new micro-parameter is calibrated using the test data of one rockfill material. Particle shape greatly affects the particle breakage rate, peak intensity and peak-related internal friction angle for rockfill materials. The final experimental grading curves all approach the particle breakage grading curve proposed by Einav (the fractal dimension is 2.7).

Originality/value

This study proposes a shape factorF, which describes the geometric features of natural rockfill particles. The proposed shape factorFhas a simple structure, and its parameters are easy to determine. The method provides an opportunity for a quantitative study on the particle shape of granular materials, and this study helps to better understand the influence of particle shape on the mechanical characteristics of rockfill materials.
Two rebelling approaches but only one embraced by policy
Authors: Eklund Magnus , Waluszewski Alexandra
Published: August 2017

Purpose

The purpose of this paper is twofold, first, to shed light on the different patterns in which international marketing and purchasing (IMP) and national innovation system (NIS) were embedded into the Swedish policy context, where the first approach must be regarded as a relative failure and the second a success, second, to compare their analytical lenses and policy implications through the study of a number of seminal texts of the two approaches.

Design/methodology/approach

First, a Swedish case is selected since it provides an example of a policy context where both approaches have been considered and used as sources of inspiration for the design of policy measures. Second, the authors study a selection of the seminal texts of the two approaches in order to identify their basic theoretical assumptions. The emphasis here lies on how the schools view the importance of relations between companies, how they perceive the innovation process, their attitude towards the neoclassical market model and the explicit and implicit implications of their theoretical assumptions for policy.

Findings

IMP and its notion of the heterogeneity of resources can provide a much more context grounded analysis than is possible within the NIS/Lundvall framework. However, it requires deep contextual knowledge of individual companies, industries and national and international settings to understand the value of these resources. IMP is “tied to the ground” and radically critical of the atomistic abstractions characterising the neoclassical market view. NIS, on the other hand, requires contextual knowledge on a more superficial level and can co-exist with neoclassical economics.

Research limitations/implications

While the authors mainly focus on IMP and NIS, which date back to the 1980s, a later wave of concepts from the 1990s and onwards involve clusters (Porter, 1990), and triple helix (Etzkowitz and Leidesdorff, 1998). However, these latecomers share with NIS the ability to co-exist with neoclassical economics.

Practical implications

IMP requires high demands on any policy maker that would adopt it, in terms of acquiring deep contextual knowledge and giving up established views on how the economy works

Originality/value

The paper reveal that while both IMP and NIS like to present themselves as rebels radically departing from neoclassical economics and the linear model, NIS can still co-exist with neoclassical economics. Furthermore, IMP places high demands on any policy maker that would adopt it, in terms of acquiring deep contextual knowledge and giving up established views on how the economy works. NIS, on the other hand, requires contextual knowledge on a more superficial level.
Constructing definitions of sustainable development
Authors: Abrahams Gareth
Published: August 2017

Purpose

The purpose of this paper is to ask how two normative definitions of sustainable development identified in the Brundtland report contribute to individual definitions constructed by a network of professional actors working in the construction industry.

Design/methodology/approach

This paper draws on 74 questionnaires generated from a purposive sample of professional actors working in the construction sector. These questionnaires are analysed using a coding strategy based on pre-defined categories generated from a review of academic and policy literature.

Findings

The results show that these definitions mostly appeal to actors working in roles with a strong input into the design process. The evidence suggests that all professional actors in the construction industry construct definitions of sustainable development to valorise their professional role, to support professional critiques of the industry or to reinforce their personal ideological beliefs.

Research limitations/implications

These results present a challenge to a normative agenda aimed at “pinning the concepts down” to an unequivocal, universal definition. It suggests that research might be better redirected towards a context dependent and pragmatic use of the term.

Practical implications

These findings suggest that future policy making should acknowledge multiple, sector and role-specific definitions of sustainable development. It also suggests that a better understanding of this diversity within the construction industry could improve the efficiency of the design, procurement and construction process.

Originality/value

These findings provide new insight into the “in use” definitions of sustainable development in the construction industry and question some of the academic arguments that support a single, universal definition of the term.
Survival rate of titanium‐zirconium narrow diameter dental implants versus commercially pure titanium narrow diameter dental implants: A systematic review
Authors: Iegami Carolina Mayumi , Uehara Priscila Nakasone , Sesma Newton , Pannuti Cláudio Mendes , Tortamano Neto Pedro , Mukai Márcio Katsuyoshi
Published: August 2017

Background

Despite the existence of several studies validating the use of narrow diameter implants, most of them are based on pure Ti alloys. There is few clinical evidence of the success of TiZr narrow diameter implants (TiZr NDIs) regarding survival rate (SR) and marginal bone loss (MLB).

Purpose

The aim of this review was to systematically assess SR, as well as MBL of TiZr NDIs compared to commercially pure titanium narrow diameter implants (cpTi NDIs).

Material and Methods

The search was conducted in Medline/PubMed, Cochrane, Scopus, and Embase databases (year 2000 to November 2016). Cohort studies and randomized trials were included.

Results

Six clinical studies from the 3453 articles initially identified met the inclusion criteria. There were no statistically significant differences in SR when TiZr NDIs and cpTi NDIs were compared in the 1‐year follow up (P = .5), or when comparing TiZr NDIs placed in posterior and anterior regions. There was no difference between groups regarding 1‐year SR: −0.01 (95% CI, −0.05‐0.03) and MLB: −0.01 mm (95% CI: −0.14‐0.12).

Conclusion

It can be concluded that TiZr NDIs present similar success rates and peri‐implant bone resorption to cpTi NDIs.
Water Table Uncertainties due to Uncertainties in Structure and Properties of an Unconfined Aquifer
Authors: Hauser Juerg , Wellmann Florian , Trefry Mike
Published: August 2017

We consider two sources of geology‐related uncertainty in making predictions of the steady‐state water table elevation for an unconfined aquifer. That is the uncertainty in the depth to base of the aquifer and in the hydraulic conductivity distribution within the aquifer. Stochastic approaches to hydrological modeling commonly use geostatistical techniques to account for hydraulic conductivity uncertainty within the aquifer. In the absence of well data allowing derivation of a relationship between geophysical and hydrological parameters, the use of geophysical data is often limited to constraining the structural boundaries. If we recover the base of an unconfined aquifer from an analysis of geophysical data, then the associated uncertainties are a consequence of the geophysical inversion process. In this study, we illustrate this by quantifying water table uncertainties for the unconfined aquifer formed by the paleochannel network around the Kintyre Uranium deposit in Western Australia. The focus of the Bayesian parametric bootstrap approach employed for the inversion of the available airborne electromagnetic data is the recovery of the base of the paleochannel network and the associated uncertainties. This allows us to then quantify the associated influences on the water table in a conceptualized groundwater usage scenario and compare the resulting uncertainties with uncertainties due to an uncertain hydraulic conductivity distribution within the aquifer. Our modeling shows that neither uncertainties in the depth to the base of the aquifer nor hydraulic conductivity uncertainties alone can capture the patterns of uncertainty in the water table that emerge when the two are combined.
Assessing Methane in Shallow Groundwater in Unconventional Oil and Gas Play Areas, Eastern Kentucky
Authors: Zhu Junfeng , Parris Thomas M. , Taylor Charles J. , Webb Steven E. , Davidson Bart , Smath Richard , Richardson Stephen D. , Molofsky Lisa J. , Kromann Jenna S. , Smith Ann P.
Published: August 2017

The expanding use of horizontal drilling and hydraulic fracturing technology to produce oil and gas from tight rock formations has increased public concern about potential impacts on the environment, especially on shallow drinking water aquifers. In eastern Kentucky, horizontal drilling and hydraulic fracturing have been used to develop the Berea Sandstone and the Rogersville Shale. To assess baseline groundwater chemistry and evaluate methane detected in groundwater overlying the Berea and Rogersville plays, we sampled 51 water wells and analyzed the samples for concentrations of major cations and anions, metals, dissolved methane, and other light hydrocarbon gases. In addition, the stable carbon and hydrogen isotopic composition of methane (δ13C‐CH4 and δ2H‐CH4) was analyzed for samples with methane concentration exceeding 1 mg/L. Our study indicates that methane is a relatively common constituent in shallow groundwater in eastern Kentucky, where methane was detected in 78% of the sampled wells (40 of 51 wells) with 51% of wells (26 of 51 wells) exhibiting methane concentrations above 1 mg/L. The δ13C‐CH4 and δ2H‐CH4 ranged from −84.0‰ to −58.3‰ and from −246.5‰ to −146.0‰, respectively. Isotopic analysis indicated that dissolved methane was primarily microbial in origin formed through CO2 reduction pathway. Results from this study provide a first assessment of methane in the shallow aquifers in the Berea and Rogersville play areas and can be used as a reference to evaluate potential impacts of future horizontal drilling and hydraulic fracturing activities on groundwater quality in the region.
Clinical and angiographic outcome of a single center, real world population treated with a dedicated technique of implantation for bioresorbable vascular scaffolds. The FAtebenefratelli Bioresorbable Vascular Scaffold (FABS) registry
Authors: Cortese Bernardo , di Palma Gaetano , Cerrato Enrico , Latini Roberto A. , Elwany Mostafa , Orrego Pedro S. , Seregni Romano G.
Published: August 2017

Objectives

With this prospective study we aim at investigating the long‐term outcome of a consecutive cohort of patients successfully treated with bioresorbable scaffold (BVS) implantation.

Background

It is not clearly understood if there is a relation between the technique of BVS implantation and the outcome.

Methods

Between December 2012 and December 2014, all consecutive patients treated with BVS were included in this registry and received an angiographic follow‐up. After a run‐in phase, all BVS were implanted using a specific technique consisting of aggressive predilation, correct scaffold sizing, visually determined, and high‐pressure post‐dilation with a noncompliance balloon. Primary endpoint was late lumen loss (LLL) at 1‐year angiographic follow‐up and ischemia‐driven target‐lesion revascularization (ID‐TLR) at 2‐year clinical follow‐up. Secondary endpoints were the occurrence of binary restenosis, major adverse cardiac events (MACE), and every single component of MACE (cardiac death, myocardial infarction, TLR) at 2 years.

Results

A total of 144 lesions in 122 patients treated consecutively with BVS, were enrolled. Diabetics were 29.5% and acute coronary syndrome at presentation occurred in 29.5% of patients. At the angiographic follow‐up LLL was 0.38 ± 0.9. At 2‐year clinical follow‐up, ID‐TLR occurred in eight patients (5.6%). We observed two cases of scaffold thrombosis (1.38%, one early and one very late). At multivariate statistical analysis, STEMI presentation remained a significant predictor for TLR.

Conclusions

In a complex, all‐comers real world population, BVS implantation with a specific, and standardized technique showed to be feasible, with acceptable mid‐term angiographic and long‐term clinical outcome.
MECHANICAL PERFORMANCE OF ROLLER COMPACTED RUBBERCRETE WITH DIFFERENT MINERAL FILLER
Authors: Adamu Musa , Mohammed Bashar S. , Shafiq Nasir
Published: August 2017

The rate of waste tire generation globally continues to escalate due to increase in vehicle usage. Scrap tires continue to pose serious environmental, health and aesthetic problems. Due limitation in the recycling of scrap tires, one of the most viable solution is to used crumb rubber from scrap tire as partial replacement to fine aggregate in concrete industry. This is rationalized as the production of concrete hit more than 3.8 billion cubic meters annually, therefore, it could provide a solution on conservation of natural aggregate and as well as improve properties of concrete. However, the major setback in the use of crumb rubber in concrete is loss in strength.  In this paper, crumb rubber was used to partially replaced fine aggregate at 0%, 10%, 20% and 30% by volume in roller compacted concrete for pavement applications to produce roller compacted rubbercrete (RCR) to improve its flexural strength and ductility. Several trials were done to achieve the combined grading as recommended by ACI 211.3R, and finally a combination of 55% fine aggregate, 40% coarse aggregate and 5% fine sand as mineral filler was used. In order to mitigate the effect of strength loss, silica fume and fly ash were used to replace natural fine sand as mineral fillers. The Results showed that fresh density, compressive, splitting and flexural strengths decreases with increase in partial replacement of fine aggregate with crumb rubber. However using silica fume as a mineral filler was successful in mitigating loss in compressive, tensile and flexural strengths for up to 20% crumb rubber replacement level, while fly ash as a mineral filler mitigated loss in strength for up to 10% crumb rubber compared natural fine sand mineral filler. The flexural strength was found to increase with 10% crumb rubber for all type of mineral filler
STATISTICAL OPTIMIZATION OF GELATIN IMMOBILISATION ON MODIFIED SURFACE PCL MICROCARRIER TO IMPROVE PCL MICROCARRIER COMPATIBILITY
Authors: Samsudin Nurhusna , Has-Yun Hashim Yumi Zuhanis , Arifin Mohd Azmir , Mel Maizirwan , Mohd. Salleh Hamzah , Nordin Norshariza , Sopyan Iis , Jimat Dzun Noraini
Published: August 2017

Growing cells on microcarriers may have overcome the limitation of conventional cell culture system. However, the main challenge remains at ensuring the surface biocompatibility with cells. Polycaprolactone (PCL), a biodegradable polymer, has received considerable attention because of its excellent mechanical properties and degradation kinetics that suit various applications, but its non-polar hydrocarbon moiety renders it sub-optimal for cell attachment. In this present study, the aim was to improve biocompatibility of PCL microcarrier by introducing oxygen functional group via ultraviolet irradiation and ozone aeration (UV/O3 system) to allow covalent immobilization of gelatin on the PCL microcarrier surface. Respond surface methodology was used as a statistical approach to optimized parameters that effect the immobilization of gelatin. The parameters used to maximized amount of gelatin immobilize were the mol ratio of COOH:EDAC, NHS concentration and gelatin concentration. The optimum conditions for maximum amount of gelatin (1797.33 µg/g) on the surface of PCL were as follows: 1.5 of COOH:EDAC ratio, 10 mM NHS concentration and, 80 mg/ml gelatin. The result shows that gelatin coated PCL microcarrier promote more and rapid cell adhesion with density of  as compared to raw PCL microcarrier (  and UV/O3 treated PCL microcarrier ( . Therefore, immobilization of gelatin with optimized parameters onto PCL microcarrier improved biocompatibility of PCL microcarrier.
EFFECTS OF COARSE PALM OIL CLINKER ON PROPERTIES OF SELF-COMPACTING LIGHTWEIGHT CONCRETE
Authors: Siew Feen Owi , Noor Mohamed Roslli , Mohamed Azman , A. Khalid Nur Hafizah
Published: August 2017

Self-compacting lightweight concrete (SCLWC) is an innovative high performance concrete which uses palm oil clinker (POC), a waste by-product from the palm oil industry, as the lightweight aggregates. This paper presents a research on the effects of utilising only POC as coarse aggregates on the fresh and hardened properties of SCLWC. Properties of SCLWC were compared to self-compacting concrete (SCC) containing crushed granite aggregates. Tests of slump flow, V-funnel, J-ring, L box and sieve segregation were conducted to characterise the self-compactability in fresh state. The hardened concrete specimens were tested for density, water absorption, ultrasonic pulse velocity (UPV), compression, tensile splitting and flexural. Results revealed that both mixes had fulfilled the self-compactability requirements as per European Guidelines whereby the fresh SCLWC exhibited better filling ability and passing ability at low segregation resistance. The inclusion of coarse POC reduced the concrete density and strength, but the SCLWC exhibited good UPV values despite greater porosity in the concrete. It can be concluded that the POC can be potentially used as coarse aggregates for producing SCLWC to manage the waste and promote environmental sustainability.