bluuebunny/crossref_metadata_2025 huggingface dataset:
Diabetes mellitus type 2 and subsite-specific colorectal cancer risk in men and women: results from the Netherlands Cohort Study on diet and cancer
Authors: de Kort Sander , Simons C.C.J.M. , van den Brandt Piet A. , Goldbohm R. Alexandra (Sandra) , Arts Ilja C.W. , de Bruine Adriaan P. , Janssen-Heijnen Maryska L.G. , Sanduleanu Silvia , Masclee Ad A.M. , Weijenberg Matty P.
Published: April 2016

Background

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of colorectal cancer (CRC); however, studies differentiating between subsites of CRC are limited. We investigated how diabetes mellitus (DM) was associated with subsite-specific CRC risk in men and women.

Methods

The Netherlands Cohort Study on diet and cancer is a prospective study among 120 852 men and women aged 55–69 years old at baseline in 1986. Information on DM, anthropometric, dietary and lifestyle factors was self-reported at baseline. T2DM was defined as the diagnosis of DM after 30 years of age. Incident CRC cases were identified by record linkage with the Netherlands cancer registry and the Dutch pathology registry. After 17.3 years of follow-up, 1735 incident male CRC cases and 1321 female CRC cases were available for analyses. Subsite-specific hazard ratios (HRs) for CRC were estimated in case–cohort analyses using Cox regression.

Results

At baseline, 3.1% of subcohort members reported T2DM, of whom 80% were diagnosed after 50 years of age. Multivariable-adjusted models showed that the risk of proximal colon cancer was significantly increased in women with T2DM versus women without T2DM (HR=1.80, 95% confidence interval: 1.10–2.94). There was no association between T2DM and the risk of overall CRC, distal colon cancer and rectal cancer in women. In men, T2DM was not associated with overall CRC (HR=0.98, 95% confidence interval: 0.64–1.50), or with risk at any subsite.

Conclusions

This prospective study showed an increased risk of proximal colon cancer in women with T2DM compared with non-T2DM women.
Effect of different therapeutic modalities on systemic, renal, and hepatic hemodynamics and short-term outcomes in cirrhotic patients with spontaneous bacterial peritonitis
Authors: Salman Tary A. , Edrees Ahmed M. , El-Said Hala H. , El-Abd Osama L. , El-Azab Gasser I.
Published: April 2016

Background

Spontaneous bacterial peritonitis (SBP) is a major risk factor for hepatorenal syndrome. Albumin infusion has been shown to prevent renal impairment and reduce mortality in SBP. The study aimed to compare the effect of different therapeutic modalities on hemodynamics and short clinical outcomes in high-risk patients with SBP.

Methods

Two hundred cirrhotic patients with SBP and bilirubin greater than 4 mg⁄dl or creatinine more than 1 mg⁄dl were enrolled. Patients were randomized to receive albumin, terlipressin, low-dose albumin plus terlipressin, or midodrine. Systemic, renal, and hepatic hemodynamics were estimated at baseline, 3, and 10 days of treatment. Renal impairment was diagnosed when the blood urea nitrogen or serum creatinine levels increased by more than 50% of the pretreatment value.

Results

SBP resolved in most of patients in all groups (P>0.05). Cardiac output and portal flow decreased, whereas systemic vascular resistance increased significantly in terlipressin and albumin plus terlipressin groups compared with the albumin group after 3 and 10 days. After 10 days, plasma renin activity, renal, and hepatic arteries resistive index were significantly higher in the midodrine group compared with the albumin group. The midodrine group did not show any significant changes in the heart rate, mean arterial pressure, cardiac output, and portal blood flow compared with the albumin group after 3 or 10 days. There was no significant difference in renal impairment or mortality between any of the groups.

Conclusion

Terlipressin and low-dose albumin plus terlipressin could be used as a therapeutic alternative to standard-dose albumin in high-risk SBP patients.
Outcomes of Solid Organ Transplant Recipients With Preexisting Malignancies in Remission: A Systematic Review and Meta-Analysis
Authors: Acuna Sergio A. , Huang Johnny W. , Daly Corinne , Shah Prakesh S. , Kim S. Joseph , Baxter Nancy N.
Published: April 2016

Background

Solid organ transplant recipients (SOTR) with a pretransplant malignancy (PTM) are at increased risk for cancer recurrence. However, it is unclear whether differences in survival and incidence of posttransplant de novo malignancies exist between recipients with PTM and those without PTM. We designed a systematic review to synthesize all available evidence assessing these outcomes.

Methods

A systematic search was performed in MEDLINE, EMBASE, and Cochrane Library to identify studies comparing the following outcomes in SOTR by PTM status: (1) all-cause mortality, (2) cancer-specific mortality, and (3) incidence of posttransplant de novo malignancy. Risk of bias was assessed using the Newcastle-Ottawa Scale.

Results

Thirty-two cohort studies were included. Recipients with PTM were at increased risk of all-cause mortality compared to recipients without PTM (pooled hazard ratio [HR], 1.51; 95% confidence interval [CI], 1.27-1.81). Similarly, recipients with PTM were 3 times more likely to die of cancer (pooled HR, 3.13; 95% CI, 2.29-4.27). The pooled HR for developing posttransplant de novo malignancy was also increased (HR, 1.92; 95% CI, 1.52-2.42). The association of all-cause mortality and SOTR with PTM did not vary by transplanted organ.

Conclusions

Pretransplant malignancy is associated with increased risk of all cause-mortality, cancer-specific mortality and of developing de novo malignancies after transplantation compared with those without PTM. These results reaffirm the need for careful selection of transplant recipients with PTM. Tailored screening and management strategies should be developed for this group of patients.
Can blind persons accurately assess body size from the voice?
Authors: Pisanski Katarzyna , Oleszkiewicz Anna , Sorokowska Agnieszka
Published: April 2016

Vocal tract resonances provide reliable information about a speaker's body size that human listeners use for biosocial judgements as well as speech recognition. Although humans can accurately assess men's relative body size from the voice alone, how this ability is acquired remains unknown. In this study, we test the prediction that accurate voice-based size estimation is possible without prior audiovisual experience linking low frequencies to large bodies. Ninety-one healthy congenitally or early blind, late blind and sighted adults (aged 20–65) participated in the study. On the basis of vowel sounds alone, participants assessed the relative body sizes of male pairs of varying heights. Accuracy of voice-based body size assessments significantly exceeded chance and did not differ among participants who were sighted, or congenitally blind or who had lost their sight later in life. Accuracy increased significantly with relative differences in physical height between men, suggesting that both blind and sighted participants used reliable vocal cues to size (i.e. vocal tract resonances). Our findings demonstrate that prior visual experience is not necessary for accurate body size estimation. This capacity, integral to both nonverbal communication and speech perception, may be present at birth or may generalize from broader cross-modal correspondences.
Bayesian methods outperform parsimony but at the expense of precision in the estimation of phylogeny from discrete morphological data
Authors: O'Reilly Joseph E. , Puttick Mark N. , Parry Luke , Tanner Alastair R. , Tarver James E. , Fleming James , Pisani Davide , Donoghue Philip C. J.
Published: April 2016

Different analytical methods can yield competing interpretations of evolutionary history and, currently, there is no definitive method for phylogenetic reconstruction using morphological data. Parsimony has been the primary method for analysing morphological data, but there has been a resurgence of interest in the likelihood-based Mk-model. Here, we test the performance of the Bayesian implementation of the Mk-model relative to both equal and implied-weight implementations of parsimony. Using simulated morphological data, we demonstrate that the Mk-model outperforms equal-weights parsimony in terms of topological accuracy, and implied-weights performs the most poorly. However, the Mk-model produces phylogenies that have less resolution than parsimony methods. This difference in the accuracy and precision of parsimony and Bayesian approaches to topology estimation needs to be considered when selecting a method for phylogeny reconstruction.
When the birds go unheard: highway noise disrupts information transfer between bird species
Authors: Grade Aaron M. , Sieving Kathryn E.
Published: April 2016

Highway infrastructure and accompanying vehicle noise is associated with decreased wildlife populations in adjacent habitats. Noise masking of animal communication is an oft-cited potential mechanism underlying species loss in sound-polluted habitats. This study documents the disruption of between-species information transfer by anthropogenic noise. Titmice and chickadees broadcast specific calls to alert kin of predator threats, and sympatric vertebrates eavesdrop on these alarm calls to avoid predators. We tested if tufted titmouse alarm call eavesdropping by northern cardinals is disrupted by road noise. We broadcast recorded alarm calls to cardinals in natural areas near and far from highways. Cardinals reliably produced predator avoidance responses in quiet trials, but all birds in noisy areas failed to respond, demonstrating that highway noise is loud enough to disrupt this type of survival-related information via masking or cognitive distraction. Birds in family Paridae are abundant, highly social and vocal residents of woodlands across the Holarctic whose alarm calls are used by many species to mediate predation risks. Our work suggests that communication network disruption is likely to be widespread, and could help explain the pattern of reduced biodiversity near roadways.
The role of neuropeptide F in a transition to parental care
Authors: Cunningham Christopher B. , VanDenHeuvel Kathryn , Khana Daven B. , McKinney Elizabeth C. , Moore Allen J.
Published: April 2016

The genetics of complex social behaviour can be dissected by examining the genetic influences of component pathways, which can be predicted based on expected evolutionary precursors. Here, we examine how gene expression in a pathway that influences the motivation to eat is altered during parental care that involves direct feeding of larvae. We examine the expression of
neuropeptide F
, and its receptor, in the burying beetle
Nicrophorus vespilloides
, which feeds pre-digested carrion to its begging larvae. We found that the
npf
receptor
was greatly reduced during active care. Our research provides evidence that feeding behaviour was a likely target during the evolution of parental care in
N. vespilloides
. Moreover, dissecting complex behaviours into ethologically distinct sub-behaviours is a productive way to begin to target the genetic mechanisms involved in the evolution of complex behaviours.
Data analytics for simplifying thermal efficiency planning in cities
Authors: Abdolhosseini Qomi Mohammad Javad , Noshadravan Arash , Sobstyl Jake M. , Toole Jameson , Ferreira Joseph , Pellenq Roland J.-M. , Ulm Franz-Josef , Gonzalez Marta C.
Published: April 2016

More than 44% of building energy consumption in the USA is used for space heating and cooling, and this accounts for 20% of national CO
2
emissions. This prompts the need to identify among the 130 million households in the USA those with the greatest energy-saving potential and the associated costs of the path to reach that goal. Whereas current solutions address this problem by analysing each building in detail, we herein reduce the dimensionality of the problem by simplifying the calculations of energy losses in buildings. We present a novel inference method that can be used via a ranking algorithm that allows us to estimate the potential energy saving for heating purposes. To that end, we only need consumption from records of gas bills integrated with a building's footprint. The method entails a statistical screening of the intricate interplay between weather, infrastructural and residents' choice variables to determine building gas consumption and potential savings at a city scale. We derive a general statistical pattern of consumption in an urban settlement, reducing it to a set of the most influential buildings' parameters that operate locally. By way of example, the implications are explored using records of a set of (
N
= 6200) buildings in Cambridge, MA, USA, which indicate that retrofitting only 16% of buildings entails a 40% reduction in gas consumption of the whole building stock. We find that the inferred heat loss rate of buildings exhibits a power-law data distribution akin to Zipf's law, which provides a means to map an optimum path for gas savings per retrofit at a city scale. These findings have implications for improving the thermal efficiency of cities' building stock, as outlined by current policy efforts seeking to reduce home heating and cooling energy consumption and lower associated greenhouse gas emissions.
L-System model for the growth of arbuscular mycorrhizal fungi, both within and outside of their host roots
Authors: Schnepf A. , Leitner D. , Schweiger P. F. , Scholl P. , Jansa J.
Published: April 2016

Development of arbuscular mycorrhizal fungal colonization of roots and the surrounding soil is the central process of mycorrhizal symbiosis, important for ecosystem functioning and commercial inoculum applications. To improve mechanistic understanding of this highly spatially and temporarily dynamic process, we developed a three-dimensional model taking into account growth of the roots and hyphae. It is for the first time that infection within the root system is simulated dynamically and in a spatially resolved way. Comparison between data measured in a calibration experiment and simulated results showed a good fit. Our simulations showed that the position of the fungal inoculum affects the sensitivity of hyphal growth parameters. Variation in speed of secondary infection and hyphal lifetime had a different effect on root infection and hyphal length, respectively, depending on whether the inoculum was concentrated or dispersed. For other parameters (branching rate, distance between entry points), the relative effect was the same independent of inoculum placement. The model also indicated that maximum root colonization levels well below 100%, often observed experimentally, may be a result of differential spread of roots and hyphae, besides intrinsic plant control, particularly upon localized placement of inoculum and slow secondary infection.
Mix it and fix it: functions of composite olfactory signals in ring-tailed lemurs
Authors: Greene Lydia K. , Grogan Kathleen E. , Smyth Kendra N. , Adams Christine A. , Klager Skylar A. , Drea Christine M.
Published: April 2016

Animals communicating via scent often deposit composite signals that incorporate odorants from multiple sources; however, the function of mixing chemical signals remains understudied. We tested both a ‘multiple-messages’ and a ‘fixative’ hypothesis of composite olfactory signalling, which, respectively, posit that mixing scents functions to increase information content or prolong signal longevity. Our subjects—adult, male ring-tailed lemurs (Lemur catta)—have a complex scent-marking repertoire, involving volatile antebrachial (A) secretions, deposited pure or after being mixed with a squalene-rich paste exuded from brachial (B) glands. Using behavioural bioassays, we examined recipient responses to odorants collected from conspecific strangers. We concurrently presented pure A, pure B and mixed A + B secretions, in fresh or decayed conditions. Lemurs preferentially responded to mixed over pure secretions, their interest increasing and shifting over time, from sniffing and countermarking fresh mixtures, to licking and countermarking decayed mixtures. Substituting synthetic squalene (S)—a well-known fixative—for B secretions did not replicate prior results: B secretions, which contain additional chemicals that probably encode salient information, were preferred over pure S. Whereas support for the ‘multiple-messages’ hypothesis underscores the unique contribution from each of an animal's various secretions, support for the ‘fixative’ hypothesis highlights the synergistic benefits of composite signals.
Rat eradication comes within a whisker! A case study of a failed project from the South Pacific
Authors: Amos W. , Nichols H. J. , Churchyard T. , Brooke M. de L.
Published: April 2016

To enhance their conservation value, several hundred islands worldwide have been cleared of invasive alien rats,Rattusspp. One of the largest projects yet undertaken was on 43 km2Henderson Island in the Pitcairn group, South Pacific, in August 2011. Following massive immediate mortality, a singleR. exulanswas observed in March 2012 and, subsequently, rat numbers have recovered. The survivors show no sign of resistance to the toxicant used, brodifacoum. Using pre- and post-operation rat tissue samples from Henderson, plus samples from around the Pacific, we exclude re-introduction as the source of continued rat presence. Microsatellite analysis of 18 loci enabled comparison of genetic diversity of Henderson rats before and after the bait drop. The fall in diversity measured by allele frequency change indicated that the bottleneck (Ne) through which the breeding population passed was probably around 50 individuals, representing a census population of about 60–80 animals. This is the first failed project that has estimated how close it was to success.
Down syndrome cell adhesion molecule 1
: testing for a role in insect immunity, behaviour and reproduction
Authors: Peuß Robert , Wensing Kristina U. , Woestmann Luisa , Eggert Hendrik , Milutinović Barbara , Sroka Marlene G. U. , Scharsack Jörn P. , Kurtz Joachim , Armitage Sophie A. O.
Published: April 2016

Down syndrome cell adhesion molecule 1
(
Dscam1
) has wide-reaching and vital neuronal functions although the role it plays in insect and crustacean immunity is less well understood. In this study, we combine different approaches to understand the roles that
Dscam1
plays in fitness-related contexts in two model insect species. Contrary to our expectations, we found no short-term modulation of
Dscam1
gene expression after haemocoelic or oral bacterial exposure in
Tribolium castaneum
, or after haemocoelic bacterial exposure in
Drosophila melanogaster.
Furthermore, RNAi-mediated
Dscam1
knockdown and subsequent bacterial exposure did not reduce
T. castaneum
survival. However,
Dscam1
knockdown in larvae resulted in adult locomotion defects, as well as dramatically reduced fecundity in males and females. We suggest that
Dscam1
does not always play a straightforward role in immunity, but strongly influences behaviour and fecundity. This study takes a step towards understanding more about the role of this intriguing gene from different phenotypic perspectives.
The development of biofilm architecture
Authors: Fowler A. C. , Kyrke-Smith T. M. , Winstanley H. F.
Published: April 2016

We extend the one-dimensional polymer solution theory of bacterial biofilm growth described by Winstanley
et al
. (2011
Proc. R. Soc. A
467
, 1449–1467 (
doi:10.1098/rspa.2010.0327
)) to deal with the problem of the growth of a patch of biofilm in more than one lateral dimension. The extension is non-trivial, as it requires consideration of the rheology of the polymer phase. We use a novel asymptotic technique to reduce the model to a free-boundary problem governed by the equations of Stokes flow with non-standard boundary conditions. We then consider the stability of laterally uniform biofilm growth, and show that the model predicts spatial instability; this is confirmed by a direct numerical solution of the governing equations. The instability results in cusp formation at the biofilm surface and provides an explanation for the common observation of patterned biofilm architectures.
On the axisymmetric stability of heated supersonic round jets
Authors: Samanta Arnab
Published: April 2016

We perform an inviscid, spatial stability analysis of supersonic, heated round jets with the mean properties assumed uniform on either side of the jet shear layer, modelled here via a cylindrical vortex sheet. Apart from the hydrodynamic Kelvin–Helmholtz (K–H) wave, the spatial growth rates of the acoustically coupled supersonic and subsonic instability waves are computed for axisymmetric conditions (
m
=0) to analyse their role on the jet stability, under increased heating and compressibility. With the ambient stationary, supersonic instability waves may exist for any jet Mach number
M

j

≥2, whereas the subsonic instability waves, in addition, require the core-to-ambient flow temperature ratio
T

j

/
T

o

>1. We show, for moderately heated jets at
T

j

/
T

o

>2, the acoustically coupled instability modes, once cut on, to govern the overall jet stability with the K–H wave having disappeared into the cluster of acoustic modes. Sufficiently high heating makes the subsonic modes dominate the jet near-field dynamics, whereas the supersonic instability modes form the primary Mach radiation at far field.
The elastic secrets of the chameleon tongue
Authors: Moulton Derek E. , Lessinnes Thomas , O’Keeffe Stephen , Dorfmann Luis , Goriely Alain
Published: April 2016

The ballistic projection of the chameleon tongue is an extreme example of quick energy release in the animal kingdom. It relies on a complicated physiological structure and an elaborate balance between tissue elasticity, collagen fibre anisotropy, active muscular contraction, stress release and geometry. A general biophysical model for the dynamics of the chameleon tongue based on large deformation elasticity is proposed. The model involves three distinct coupled subsystems: the energetics of the intralingual sheaths, the mechanics of the activating accelerator muscle and the dynamics of tongue extension. Together, these three systems elucidate the key physical principles of prey-catching among chameleonides.
Sentinel cells, symbiotic bacteria and toxin resistance in the social amoeba
Dictyostelium discoideum
Authors: Brock Debra A. , Callison W. Éamon , Strassmann Joan E. , Queller David C.
Published: April 2016

The social amoeba
Dictyostelium discoideum
is unusual among eukaryotes in having both unicellular and multicellular stages. In the multicellular stage, some cells, called sentinels, ingest toxins, waste and bacteria. The sentinel cells ultimately fall away from the back of the migrating slug, thus removing these substances from the slug. However, some
D. discoideum
clones (called farmers) carry commensal bacteria through the multicellular stage, while others (called non-farmers) do not. Farmers profit from their beneficial bacteria. To prevent the loss of these bacteria, we hypothesize that sentinel cell numbers may be reduced in farmers, and thus farmers may have a diminished capacity to respond to pathogenic bacteria or toxins. In support, we found that farmers have fewer sentinel cells compared with non-farmers. However, farmers produced no fewer viable spores when challenged with a toxin. These results are consistent with the beneficial bacteria
Burkholderia
providing protection against toxins. The farmers did not vary in spore production with and without a toxin challenge the way the non-farmers did, which suggests the costs of
Burkholderia
may be fixed while sentinel cells may be inducible. Therefore, the costs for non-farmers are only paid in the presence of the toxin. When the farmers were cured of their symbiotic bacteria with antibiotics, they behaved just like non-farmers in response to a toxin challenge. Thus, the advantages farmers gain from carrying bacteria include not just food and protection against competitors, but also protection against toxins.
Using Y chromosomal haplogroups in genetic association studies and suggested implications
Authors: Erzurumluoglu A. Mesut , Baird Denis , Richardson Tom G. , Timpson Nicholas J. , Rodriguez Santiago
Published: April 2016

Y chromosomal (Y-DNA) haplogroups are more widely used in population genetics than in genetic epidemiology, although associations between Y-DNA haplogroups and several traits (including cardio-metabolic traits) have been reported. In apparently homogeneous populations, there is still Y-DNA haplogroup variation which will result from population history. Therefore, hidden stratification and/or differential phenotypic effects by Y-DNA haplogroups could exist. To test this, we hypothesised that stratifying individuals according to their Y-DNA haplogroups before testing associations between autosomal SNPs and phenotypes will yield difference in association. For proof of concept, we derived Y-DNA haplogroups from 6,537 males from two epidemiological cohorts, ALSPAC (N=5,080, 816 Y-DNA SNPs) and 1958 Birth Cohort (N=1,457, 1,849 Y-DNA SNPs). For illustration, we studied well-known associations between 32 SNPs and body mass index (BMI), including associations involvingFTOSNPs. Overall, no association was replicated in both cohorts when Y-DNA haplogroups were considered and this suggests that, for BMI at least, there is little evidence of differences in phenotype or gene association by Y-DNA structure. Further studies using other traits, Phenome-wide association studies (PheWAS), haplogroups and/or autosomal SNPs are required to test the generalisability of this approach.
Impact of knowledge accumulation on pathway enrichment analysis
Authors: Wadi Lina , Meyer Mona , Weiser Joel , Stein Lincoln D. , Reimand Jüri
Published: April 2016

Pathway-based interpretation of gene lists is a staple of genome analysis. It depends on frequently updated gene annotation databases. We analyzed the evolution of gene annotations over the past seven years and found that the vocabulary of pathways and processes has doubled. This strongly impacts practical analysis of genes: 80% of publications we surveyed in 2015 used outdated software that only captured 20% of pathway enrichments apparent in current annotations.
Cosmid based mutagenesis causes genetic instability inStreptomyces coelicolor, as shown by targeting of the lipoprotein signal peptidase gene
Authors: Munnoch John T , Widdick David A. , Chandra Govind , Sutcliffe Iain C. , Palmer Tracy , Hutchings Matthew I
Published: April 2016

Bacterial lipoproteins are a class of extracellular proteins tethered to cell membranes by covalently attached lipids. Deleting the lipoprotein signal peptidase (lsp) gene inStreptomyces coelicolorresults in growth and developmental defects that cannot be restored by reintroducing thelsp. We report resequencing of the genomes of the wild-type M145 and thecis-complemented Δlspmutant (BJT1004), mapping and identifying secondary mutations, including an insertion into a novel putative small RNA,scr6809. Disruption ofscr6809led to a range of developmental phenotypes. However, these secondary mutations do not increase the efficiency of disruptinglspsuggesting they are notlspspecific suppressors. Instead we suggest that these were induced by introducing the cosmid St4A10Δlspas part of the Redirect mutagenesis protocol, which transiently duplicates a number of important cell division genes. Disruption oflspusing no gene duplication resulted in the previously observed phenotype. We conclude thatlspis not essential inS. coelicolorbut loss oflspdoes lead to developmental defects due to the loss of lipoproteins from the cell. Significantly, our results indicate the use of cosmid libraries for the genetic manipulation of bacteria can lead to unexpected phenotypes not necessarily linked to the gene or pathway of interest.
Guided self-organization recapitulates tissue architecture in a bioengineered brain organoid model
Authors: Lancaster Madeline A. , Corsini Nina S. , Burkard Thomas R. , Knoblich Juergen A.
Published: April 2016

Recently emerging methodology for generating human tissuesin vitrohas the potential to revolutionize drug discovery and disease research. Currently, three-dimensional cell culture models either rely on the pronounced ability of mammalian cells to self organizein vitro1-6, or use bioengineered constructs to arrange cells in an organ-like configuration7,8. While self-organizing organoids can recapitulate developmental events at a remarkable level of detail, bioengineered constructs excel at reproducibly generating tissue of a desired architecture. Here, we combine these two approaches to reproducibly generate micropatterned human forebrain tissue while maintaining its self-organizing capacity. We utilize poly(lactide-co-glycolide) copolymer (PLGA) fiber microfilaments as a scaffold to generate elongated embryoid bodies and demonstrate that this influences tissue identity. Micropatterned engineered cerebral organoids (enCORs) display enhanced neuroectoderm formation and improved cortical development. Furthermore, we reconstitute the basement membrane at later stages leading to characteristic cortical tissue architecture including formation of a polarized cortical plate and radial units. enCORs provide the firstin vitrosystem for modelling the distinctive radial organization of the cerebral cortex and allow for the study of neuronal migration. We demonstrate their utility by modelling teratogenic effects of ethanol and show that defects in leading process formation may be responsible for the neuronal migration deficits in fetal alcohol syndrome. Our data demonstrate that combining 3D cell culture with bioengineering can significantly enhance tissue identity and architecture, and establish organoid models for teratogenic compounds.
Periodic actin structures in neuronal axons are required to maintain microtubules
Authors: Qu Yue , Hahn Ines , Webb Stephen , Pearce Simon P. , Prokop Andreas
Published: April 2016

Axons are the cable-like neuronal processes wiring the nervous system. They contain parallel bundles of microtubules as structural backbones, surrounded by regularly-spaced actin rings termed the periodic membrane skeleton (PMS). Despite being an evolutionarily-conserved, ubiquitous, highly-ordered feature of axons, the function of PMS is unknown. Here we studied PMS abundance, organisation and function, combining versatileDrosophilagenetics with super-resolution microscopy and various functional readouts. Analyses with 11 different actin regulators and 3 actin-targeting drugs suggest PMS to contain short actin filaments which are depolymerisation resistant and sensitive to spectrin, adducin and nucleator deficiency - consistent with microscopy-derived models proposing PMS as specialised cortical actin. Upon actin removal we observed gaps in microtubule bundles, reduced microtubule polymerisation and reduced axon numbers suggesting a role of PMS in microtubule organisation. These effects become strongly enhanced when carried out in neurons lacking the microtubule-stabilising protein Short stop (Shot). Combining the aforementioned actin manipulations with Shot deficiency revealed a close correlation between PMS abundance and microtubule regulation, consistent with a model in which PMS-dependent microtubule polymerisation contributes to their maintenance in axons. We discuss potential implications of this novel PMS function along axon shafts for axon maintenance and regeneration.

Significance statement

Axons are cable-like neuronal processes that are up to a meter long in humans. These delicate structures often need to be maintained for an organism’s lifetime, i.e. up to a century in humans. Unsurprisingly, we gradually lose about 50% of axons as we age. Bundles of microtubules form the structural backbones and highways for life-sustaining transport within axons, and maintenance of these bundles is essential for axonal longevity. However, the mechanisms which actively maintain axonal microtubules are poorly understood. Here we identify cortical actin as an important factor maintaining microtubule polymerisation in axons. This finding provides potential explanations for the previously identified, but unexplained, links between mutations in genes encoding cortical actin regulators and neurodegeneration.
Segmentation of infrequent performing arts consumers
Authors: Kolhede Eric John , Gomez-Arias J. Tomas
Published: April 2016

Purpose

– The purpose of this paper is to examine market segments within the broader category of occasional patrons of the performing arts. While similarities between these segments exist, important distinctions are also apparent.

Design/methodology/approach

– The authors surveyed 347 performing arts patrons using a structured questionnaire. Their responses along 28 proposed motivational variables were subjected to factor analysis to reduce their dimensionality and collinearity. Cluster analysis was then applied to respondents’ factor scores to group subjects into homogenous segments for subsequent comparison along variables, including demographic and marketing mix elements.

Findings

– The authors find six key motivating factors influencing the attendance of performing arts events: personal; promotional; product; distribution; economic; and social motivators. The authors also find that infrequent consumers can be further subsegmented into disinclined and fringe consumers with different levels of performance attendance and dissimilarities in responding to motivators.

Research limitations/implications

– The survey was conducted in a single county within the San Francisco Bay Area, limiting the generalizability of results.

Practical implications

– Fringe consumers are more responsive to the personal benefits (e.g. cultural enrichment) derived from the core product offerings of a performance such as programming and quality of the performers. The disinclined segment is more influenced by economic, social, and distribution related elements associated with a performing arts event such as pricing, the accessibility (or convenience) of the venue, and the opportunity to socialize accompanying attendance.

Social implications

– The practice of relationship marketing by small local performing arts organizations (PAOs) has been emphasized and often advocated by researches in the most recent literature. In order to ensure the viability of PAOs beyond the short-term, further examination of audience development is imperative. This paper indeed places more attention on audience development with a particular focus on expanding audiences among subsegments of infrequent performing arts consumers.

Originality/value

– The central purpose of this research is to arrive at comprehensive profiles of subsegments within a group of infrequent arts patrons, along with viable differentiated marketing program and positioning approaches that would appeal to each of these consumer categories. Consequently, the authors address a significant gap in the performing arts marketing literature as few recent studies appear to have been structured to allow for the possibility of producing adequate subsegmentation information within a group of occasional performing arts patrons. Secondarily, this study also answers a call for future research to examine the internet as a channel of promotion for arts consumers.
A sensemaking perspective on arts sponsorship decisions
Authors: Daellenbach Kate , Zander Lena , Thirkell Peter
Published: April 2016

Purpose

– The purpose of this paper is to better understand the sensemaking strategies of managers involved in making decisions concerning arts sponsorship.

Design/methodology/approach

– A qualitative, multiple case method is employed, using multiple informants in ten arts sponsorship decisions. Within and between case analyses were conducted and examined iteratively, along with literature to generate themes to guide future research.

Findings

– This study finds art sponsorships may be seen as ambiguous, cueing sensemaking; the sensemaking strategies of senior managers involve response to pro-social cues while middle managers draw on commercial benefit cues; sensebreaking and sensegiving are part of the process; and the actors and their interpretations draw from cues in the organisational frames of reference which act as filters, giving meaning to the situations.

Research limitations/implications

– This study presents a novel perspective on these decisions, focusing on the micro-level actions and interpretations of actors. It extends current understanding of sponsorship decision making, contributing to a perspective of managers responding to cues, interacting and making sense of their decisions.

Practical implications

– For arts managers, this perspective provides understanding of how managers (potential sponsors) respond to multiple cues, interpret and rationalise arts sponsorships. For corporate managers, insights reveal differences in sensemaking between hierarchical levels, and the role of interaction, and organisational frames of reference.

Originality/value

– This study is unique in its approach to understanding these decisions in terms of sensemaking, through the use of multiple informants and multiple case studies.
Analysis of the internal flow behavior on S-shaped region of a Francis pump turbine on turbine mode
Authors: Xiao Yexiang , Zhu Wei , Wang Zhengwei , zhang jin , Zeng Chongji , Yao Yangyang
Published: April 2016

Purpose

Numerically analyzed the flow characteristic and explored the hydrodynamic mechanism of the S-shaped region formation of a Francis pump-turbine.

Design/methodology/approach

Three-dimensional steady and unsteady simulations were performed for a number of operating conditions at the optimal guide vanes opening. The steady Reynolds averaged Navier-Stokes equations with the SST turbulence model were solved to model the internal flow within the entire flow passage. The predicted discharge-speed curve agrees well with the model test at generating mode. This paper compared the hydrodynamic characteristics of for off-design cases in S-shaped region with the optimal operating case, and more analysis focuses particularly on very low positive and negative discharge cases with the same unit speed.

Findings

At runaway case towards smaller discharge, the relative circumferential velocity becomes stronger in the vaneless, which generates the “water ring” and blocks the flow between guide vane and runner. The runner inlet attack angle becomes larger, and the runner blade passages nearly filled with flow separation and vortexes. The deterioration of runner blade flow leads to the dramatic decrease of runner torque, which tends to reduce the runner rotation speed. In this situation, the internal flow can’t maintain the larger rotating speed at very low positive discharge cases, so the unit discharge-speed curves bend to S-shaped near runaway case.

Originality/value

The analysis method of four off-design cases on S-shaped region with the comparison of optimal operation case and the calculated attack angles are adopted to explore the mechanism of S characteristic. The flow characteristic and quantitative analysis all explain the bending of the unit discharge-speed curves.
DEM modeling of cantilever retaining excavations: implications for lunar constructions
Authors: Jiang Mingjing , Shen Zhifu , Utili Stefano
Published: April 2016

Purpose

Retained excavation is important for future lunar exploratory missions and potential human colonization that requires the construction of permanent outposts. Knowledge in excavation obtained on the Earth is not directly applicable to lunar excavation because of the low lunar gravity and the non-negligible adhesive van der Waals interactions between lunar regolith grains. This study aims at revealing how the gravity level and lunar environment conditions should be considered to extend the knowledge in Earth excavation response to lunar excavation.

Design/methodology/approach

Two-dimensional Discrete Element Method (DEM) simulations were carried out to investigate the respective effect of gravity level and lunar environment conditions (high vacuum and extreme temperature) on retained excavation response. A novel contact model was employed with a moment – relative rotation law to account for the angularity of lunar soil particles, and a normal attractive force to account for the van der Waals interactions.

Findings

The simulation results showed that the excavation response is non-linearly related to the gravity level. Van der Waals interactions can increase the dilatancy of lunar regolith and, surprisingly as a consequence, significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Based on the simulation results, a parabola model was proposed to predict the excavation induced lateral ground movements on the Moon.

Originality/value

This study indicates that an unsafe estimate of the wall response to an excavation on the Moon would be obtained if only the effect of gravity is considered while the effect of van der Waals interactions is neglected.
A comparative study on the computation of directional overcurrent relay coordination in power systems using PSO and TLBO based optimization
Authors: Saha Debasree , Datta Asim , Saha Roy Biman Kumar , Das Priyanath
Published: April 2016

Purpose

Directional Overcurrent Relay (DOCR) coordination computation allowing for desired and high level accuracy in interconnected power systems is very difficult and is a highly constraint oriented optimization problem. This paper aims to study the effectiveness of a newly reported optimization technique, Teaching Learning Based Optimization (TLBO), in protective relay coordination comparing with a widely used optimization technique, Particle Swarm Optimization (PSO).

Design/methodology/approach

DOCR coordination in electric power systems is considered as an optimization problem by formulating objective function and specifying problem constraints. Optimum values of the DOCR adjustment parameters (Time Dial Setting and Plug Setting) in terms of reliable coordination margin and operating times of relays are computed by both the algorithms, TLBO and PSO. Optimal coordination is verified in three test bus systems: IEEE 6-bus, WSCC 9-bus and IEEE 14-bus systems.

Findings

A comparison between the numerical results of using both the algorithms indicates that the TLBO gives better results in terms of the total operating times of relays and Coordination Time Interval (CTI).

Originality/value

This paper represents the performance of a newly reported optimization technique, TLBO which is till now unpopular to protection engineers to be applied in protective relay coordination applications. The technique provides better performance in comparison to the widely applied technique, PSO. It is expected that TLBO would facilitate protection engineers to decide the optimum and appropriate settings of the relays for leading exact relays coordination.
A new strain-based finite element for plane elasticity problems
Authors: Hamadi Djamal , Ayoub Ashraf , Maalem Toufik
Published: April 2016

Purpose

In this paper, a new quadrilateral strain-based element is developed. The element has five nodes, four at the corners as well as an internal node.

Design/methodology/approach

Through the introduction of the internal node, the numerical performance of the element proved to be superior to existing elements in the literature, even though a static condensation is required.

Findings

From several numerical examples, it is shown that convergence can be achieved with the use of only a small number of finite elements. The proposed element can be used to solve general plane linear elasticity problems resulting in excellent results.

Originality/value

The results obtained are comparable with those given by the robust element Q8.
Update to "Extraction of elementary siphons in a class of generalized Petri nets using graph theory" [Engineering Computations (2014) 31(2)331-352]
Authors: Hou YiFan , Zhao Mi
Published: April 2016

Purpose

The purpose of this paper is to correct some mistakes in recently published paper (Hou, Y.F., Li, Z.W., Zhao, M., and Liu, D. (2014) “Extraction of elementary siphons in a class of generalized Petri nets using graph theory”, Engineering Computations, Vol.31, No.2, pp.331-352).

Design/methodology/approach

In (Hou et al., 2014), based on the concepts of initial resource weighted digraphs and restricted subgraphs, a structurally simple liveness-enforcing supervisor for WS3PR was designed. To demonstrate the effectiveness and applicability of the proposed method, a flexible manufacturing system (FMS) example was presented. However, there are some mistakes in the considered example. The derived monitors were incorrect, which caused the result that the final controlled net system is not live.

Findings

In order to correct the errors in (Hou et al., 2014), a liveness-enforcing Petri nets supervisor with revised monitors for the considered example was redesigned by applying the method in (Hou et al., 2014).

Originality/value

This paper corrected the mistakes in (Hou et al., 2014). Consequently, a liveness-enforcing Petri net supervisor is redesigned.
“Wasta” and women’s careers in the Arab Gulf States
Authors: Abalkhail Jouharah M. , Allan Barbara
Published: April 2016

Purpose

Women are under-represented in senior positions across the world, and this paper aims to explore the impact ofwastaon women’s careers in the Arab Gulf States. This paper has two main objectives: to understand the phenomenon ofwastaand how it manifests itself within public organisations in the Gulf region; and to examine howwastais impacting on women’s career advancement.

Design/methodology/approach

Qualitative interviews were conducted with 18 female managers working in public organisations in the Arab Gulf region.

Findings

The findings indicate thatwastarefers to a social network of interpersonal connections, rooted in family and kinship ties, and linked to family affairs as well as work. In addition, the findings demonstrate that, as a result ofwasta, social networks in the workplace, in the Arab Gulf Region, include family connections, and this is different to workplace networks in Western societies which are frequently limited to professional contacts and separate from family or friendship networks. In addition, the findings show thatwastamay be used to support women’s career progression, providing they have access to appropriatewasta. Furthermore, the findings revealed that women, in the Arab Gulf Region, rely directly on their male family member’s connections, as career facilitators, to gain access to organisational opportunities.

Practical implications

The paper provides some practical suggestions for helping to overcome the potential negative effects ofwastaand to ensure that organisations make the best use of their talent. Hence, this research could potentially inform national policy and organisational policymakers and, in particular, influence recruitment and selection practices to ensure that they are based on competence rather than personal connections.

Originality/value

The paper is based on empirical work in an under-researched, non-Western context. There is extensive literature on gender and management and leadership in Western cultures, and this paper contributes to the developing body of research on women in the Arab cultures. It provides a better understanding of the phenomenon ofwasta, and it highlights the long-term consequences ofwastaon employees, particularly women, working in public organisations. Also, it contributes to theory on the culture of organisations by highlighting the often neglected influences of the broader social and cultural systems, including patriarchal practices, on women’s positions in the organisational hierarchy.