bluuebunny/crossref_metadata_2025 huggingface dataset:
Partial least squares model for dynamic rating of overhead lines in wind intensive areas based on field measurements
Authors: Abdelkader Sobhy M. , John Morrow D. , Fu Jiao , Abbot Stephen
Published: November 2013

This paper presents a statistical model for the thermal behaviour of the line model based on lab tests and field measurements. This model is based on Partial Least Squares (PLS) multi regression and is used for the Dynamic Line Rating (DLR) in a wind intensive area. DLR provides extra capacity to the line, over the traditional seasonal static rating, which makes it possible to defer the need for reinforcement the existing network or building new lines. The proposed PLS model has a number of appealing features; the model is linear, so it is straightforward to use for predicting the line rating for future periods using the available weather forecast. Unlike the available physical models, the proposed model does not require any physical parameters of the line, which avoids the inaccuracies resulting from the errors and/or variations in these parameters. The developed model is compared with physical model, the Cigre model, and has shown very good accuracy in predicting the conductor temperature as well as in determining the line rating for future time periods.
Fractional noise destroys or induces a stochastic bifurcation
Authors: Yang Qigui , Zeng Caibin , Wang Cong
Published: November 2013

Little seems to be known about the stochastic bifurcation phenomena of non-Markovian systems. Our intention in this paper is to understand such complex dynamics by a simple system, namely, the Black-Scholes model driven by a mixed fractional Brownian motion. The most interesting finding is that the multiplicative fractional noise not only destroys but also induces a stochastic bifurcation under some suitable conditions. So it opens a possible way to explore the theory of stochastic bifurcation in the non-Markovian framework.
Microwave assistance effect on magnetization switching in Co-Cr-Pt granular film
Authors: Okamoto Satoshi , Kikuchi Nobuaki , Hotta Akira , Furuta Masaki , Kitakami Osamu , Shimatsu Takehito
Published: November 2013

Experimental verification of microwave assistance effect on a perpendicular magnetic CoCrPt based granular film is demonstrated. Significant reduction of coercivity under the assistance of a radio frequency (rf) field is clearly observed. But the coercivity strongly depends on the duration of rf field, indicating that the magnetic moments of constituent grains are severely perturbed by thermal agitation. Analysis based on the Néel-Arrhenius law has revealed that the dynamic coercivity in nanosecond region can be reduced by 50% only by applying a small rf field with the amplitude less than 2% of the anisotropy field.
Thermal transport through an exciton-condensate Josephson junction based on graphene double layers
Authors: Zhang Chuanyi , Jin Guojun
Published: November 2013

We study the thermal transport through a temperature-biased exciton-condensate Josephson junction composed of two separated graphene double layers. The total heat current can be controlled by the temperatures of the two exciton condensates, which keep coherence even at higher temperatures. We find there are important physical effects indispensable in designing two thermal devices: One is the thermal rectifier with the rectification ratio up to 3.3 × 104%; the other is the thermal logic gate, and its on and off states are easily operated. These results are feasible to verify under the present experimental conditions.
Improvement of field emission properties of α-Fe2O3 nanoflakes due to the lowered back contact barrier after high energy X-ray irradiation
Authors: Wu J. Q. , Wang B. , Yi F. T. , Deng S. Z. , Xu N. S. , Chen Jun
Published: November 2013

Improvement in the field emission properties of α-Fe2O3 nanoflakes is observed after high energy X-ray irradiation from synchrotron radiation. Field emission threshold field of α-Fe2O3 nanoflakes is found to decrease from 10.1 to 7.8 MV/m after X-ray irradiation with the dose of 9.0 × 1014 phs/cm2. Electrical measurement reveals that the potential barrier at the back contact between the α-Fe2O3 layer and the iron substrate changes after X-ray irradiation. The observed threshold field decrease is well explained by the changes in potential barrier at the back contact of α-Fe2O3 nanoflakes, which indicates the back contact plays an important role in controlling the field emission properties of α-Fe2O3 nanoflakes. Our study shows that the α-Fe2O3 nanoflakes are a promising material for the application as field emitter under X-ray environment.
Realization of single-termination SrTiO3 (100) surfaces by a microwave-induced hydrothermal process
Authors: Velasco-Davalos Ivan , Thomas Reji , Ruediger Andreas
Published: November 2013

A microwave-induced hydrothermal etching of SrTiO3 (100) single crystal surfaces in deionized water and subsequent annealing in oxygen atmosphere results in single-terminated and atomically flat terraces for pure and niobium-doped substrates as confirmed through one unit-cell step height and uniform phase by atomic force microscopy. This process that requires 3 min of moderate microwave radiation completely avoids the use of hydrofluoric acid (HF) and related point defects due to fluorine in the crystal surface. The advantages of a safe, inexpensive, and environmentally neutral process hold promise to replace the existing standard protocol for substrate preparation based on buffered HF.
Real-Geographic-Scenario-Based Virtual Social Environments: Integrating Geography with Social Research
Authors: Chen Min , Lin Hui , Hu Mingyuan , He Li , Zhang Chunxiao
Published: November 2013

Existing online virtual worlds, or electronic environments, are of great significance to social science research, but are somewhat lacking in rigour. One reason is that users might not participate in those virtual worlds in the way they act in real daily life, communicating with each other in familiar environments and interacting with natural phenomena under the constraints of the human–land relationship. To help solve this problem we propose the real-geographic-scenario-based virtual social environment (RGSBVSE). The aim is to enhance the ability of current virtual worlds in social issues studies by promoting virtual geographic environments that are built with real scenarios in the physical world. In this paper we first discuss the potential shortage of current virtual worlds for serious social research. We then explain how real geographic scenarios can contribute to building a virtual social environment by providing (1) real geographic data, including the time dimension, in terms of data acquisition and organisation; (2) dynamic or real-time natural phenomena and processes for scenario simulation and expression; (3) shared spaces that enhance participants' interaction through a mix of virtuality and reality; and (4) shared hot spots of social phenomena for researchers from multidisciplinary (eg, sociology, psychology) performing collaborative research. Furthermore, two of our projects, the virtual Chinese University of Hong Kong and the Virtual Globe of the Chinese Family Tree, are introduced as case studies, to illustrate how the RGSBVSE can play a significant role in a number of critical social research issues from the local to regional scale.
Longitudinal comparison of a physiotherapist-led, home-based and group-based program for increasing physical activity in community-dwelling middle-aged adults
Authors: Freene Nicole , Waddington Gordon , Davey Rachel , Cochrane Tom
Published: November 2013

Few studies have compared the longer-term effects of physical activity interventions. Here we compare a 6-month physiotherapist-led, home-based physical activity program to a community group exercise program over 2 years. Healthy, sedentary community-dwelling 50–65 year olds were recruited to a non-randomised community group exercise program (G, n = 93) or a physiotherapist-led, home-based physical activity program (HB, n = 65). Outcomes included ‘sufficient’ physical activity (Active Australia Survey), minutes of moderate-vigorous physical activity (ActiGraph GT1M), aerobic capacity (2-min step-test), quality of life (SF-12v2), blood pressure, waist circumference, waist-to-hip ratio and body mass index. Outcome measures were collected at baseline, 6, 12, 18 and 24 months. Using intention-to-treat analysis, both interventions resulted in significant and sustainable increases in the number of participants achieving ‘sufficient’ physical activity (HB 22 v. 41%, G 22 v. 47%, P ≤ 0.001) and decreases in waist circumference (HB 90 v. 89 cm, G 93 v. 91 cm, P < 0.001) over 2 years. The home-based program was less costly (HB A$47 v. G $84 per participant) but less effective in achieving the benefits at 2 years. The physiotherapist-led, home-based physical activity program may be a low-cost alternative to increase physical activity levels for those not interested in, or unable to attend, a group exercise program.
This study has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), Clinical Trial Registration number ACTRN12611000890932.
Distinct biophysical mechanisms of focal adhesion kinase mechanoactivation by different extracellular matrix proteins
Authors: Seong Jihye , Tajik Arash , Sun Jie , Guan Jun-Lin , Humphries Martin J. , Craig Susan E. , Shekaran Asha , García Andrés J. , Lu Shaoying , Lin Michael Z. , Wang Ning , Wang Yingxiao
Published: November 2013

Significance

Mechanical forces, which guide cellular functions, can be sensed and translated into biochemical information at focal adhesions, where cells physically connect to extracellular matrix (ECM) through transmembrane receptor integrins. Our results have identified that different ECM proteins, type 1 collagen (Col I) and fibronectin (FN), can either transmit or shield from mechanical forces when regulating crucial intracellular signaling, focal adhesion kinase (FAK), with their different accessibility to the corresponding integrin receptors. Whereas the integrin α2 binding site in Col I is constitutively accessible, mechanical tension is required to expose the integrin α5 binding motif in FN. This finding should advance our understanding on how cells perceive extracellular mechanical cues through natural surface materials.
Real-time, high-resolution study of nanocrystallization and fatigue cracking in a cyclically strained metallic glass
Authors: Wang Cheng-Cai , Mao Yun-Wei , Shan Zhi-Wei , Dao Ming , Li Ju , Sun Jun , Ma Evan , Suresh Subra
Published: November 2013

Significance

The formation of nanocrystals and cracks in metallic glasses subjected to cyclically varying strains in micro- and nanoscale systems is a topic of scientific and technological interest. However, no real-time studies of such phenomena in fatigued metallic glasses have thus far been reported. Here we present unique observations of nanocrystallization and the onset and progression of fatigue failure in a metallic glass through cyclic straining experiments conducted inside a high-resolution transmission electron microscope. Molecular dynamics simulations were also performed to elucidate the underlying mechanisms. We expect that these techniques and results will provide unique fundamental insights into how crystallization occurs in a wide variety of amorphous materials and will help develop strategies for the design and use of metallic glasses.
The effect of prescriptivism on comparative markers in spoken Dutch
Authors: Hubers Ferdy , de Hoop Helen
Published: November 2013

Dutch prescriptive grammar rules dictate that the complementizer dan ‘than’ should be used in comparative constructions of inequality. This has been an issue for grammarians from the sixteenth century onwards when als ‘as’ started to be used as an alternative form in this type of context. In order to find out why and when people choose one comparative marker over the other, we examined the use of these markers in the Spoken Dutch Corpus (CGN). We found that the use of dan is overall more common than als in comparative constructions of inequality, even though from a linguistic point of view als might be favoured. The choice between als and dan turns out to be strongly correlated with the level of education. Although this factor has been assumed to be of influence for a long time, as far as we know it has never been quantitatively tested before. We conclude that the effect of the level of education we found reflects the strong influence of the prescriptive rule taught in schools, repressing the use of als in comparatives of inequality.
Continuum mechanics of line defects in liquid crystals and liquid crystal elastomers
Authors: Acharya Amit , Dayal Kaushik
Published: November 2013

This paper generalizes the Ericksen-Leslie continuum model of liquid crystals to allow for dynamically evolving line defect distributions. In analogy with recent mesoscale models of dislocations, we introduce fields that represent defects in orientational and positional order through the incompatibility of the director and deformation ‘gradient’ fields. These fields have several practical implications: first, they enable a clear separation between energetics and kinetics; second, they bypass the need to explicitly track defect motion; third, they allow easy prescription of complex defect kinetics in contrast to usual regularization approaches; and finally, the conservation form of the dynamics of the defect fields has advantages for numerical schemes.

We present a dynamics of the defect fields, motivating the choice physically and geometrically. This dynamics is shown to satisfy the constraints, in this case quite restrictive, imposed by material-frame indifference. The phenomenon of permeation appears as a natural consequence of our kinematic approach. We outline the specialization of the theory to specific material classes such as nematics, cholesterics, smectics and liquid crystal elastomers. We use our approach to derive new, non-singular, finite-energy planar solutions for a family of axial wedge disclinations.
featureCounts: an efficient general purpose program for assigning sequence reads to genomic features
Authors: Liao Yang , Smyth Gordon K. , Shi Wei
Published: November 2013

Motivation: Next-generation sequencing technologies generate millions of short sequence reads, which are usually aligned to a reference genome. In many applications, the key information required for downstream analysis is the number of reads mapping to each genomic feature, for example to each exon or each gene. The process of counting reads is called read summarization. Read summarization is required for a great variety of genomic analyses but has so far received relatively little attention in the literature.

Results: We present featureCounts, a read summarization program suitable for counting reads generated from either RNA or genomic DNA sequencing experiments. featureCounts implements highly efficient chromosome hashing and feature blocking techniques. It is considerably faster than existing methods (by an order of magnitude for gene-level summarization) and requires far less computer memory. It works with either single or paired-end reads and provides a wide range of options appropriate for different sequencing applications.

Availability and implementation:   featureCounts is available under GNU General Public License as part of the Subread (http://subread.sourceforge.net) or Rsubread (http://www.bioconductor.org) software packages.

Contact:   shi@wehi.edu.au
Phylogeny, Morphology, Distribution, and Pathogenicity of Botryosphaeriaceae and Diaporthaceae from English Walnut in California
Authors: Chen ShuaiFei , Morgan David P. , Hasey Janine K. , Anderson Kathleen , Michailides Themis J.
Published: November 2013

Species of family Botryosphaeriaceae and genus Diaporthe (anamorph: genus Phomopsis, family Diaporthaceae) were reported and caused diseases on various fruit and nut trees in California. In the last several years, diseases on English walnut (Juglans regia) caused by species of Botryosphaeriaceae and Diaporthe were observed frequently in California. Disease symptoms include stem canker; shoot canker and blight; twig, leaf, and fruit blight; and necrotic leaf lesions. Isolates of the pathogen were collected from English walnut in 13 counties in California. The aims of this study were to identify these isolates and to test their pathogenicity to English walnut cultivars. In total, 159 California isolates were identified based on comparisons of DNA sequence data of the internal transcribed spacer, translation elongation factor 1-α, and β-tubulin gene regions, and combined with the morphological features of the cultures and conidia. Research results revealed that isolates represent 10 species of Botryosphaeriaceae and two species of Diaporthe. These species include Botryosphaeria dothidea, Diplodia mutila, D. seriata, Dothiorella iberica, Lasiodiplodia citricola, Neofusicoccum mediterraneum, N. nonquaesitum, N. parvum, N. vitifusiforme, Neoscytalidium dimidiatum, Diaporthe neotheicola, and D. rhusicola. Pathogenicity on three English walnut cultivars (‘Chandler’, ‘Tulare’, and ‘Vina’) using a mycelium plug inoculation method revealed that all these species are pathogenic to all the tested cultivars, with L. citricola and N. parvum being the most pathogenic species, followed by N. mediterraneum, N. dimidiatum, and B. dothidea. Chandler was more tolerant to infection than Tulare and Vina. Results in this study determined that multiple numbers of the Botryosphaeriaceae fungi and two Diaporthe spp. cause cankers and blights of English walnut and vary in their virulence from highly to slightly virulent, respectively.
Evidence for a recent origin of penguins
Authors: Subramanian Sankar , Beans-Picón Gabrielle , Swaminathan Siva K. , Millar Craig D. , Lambert David M.
Published: November 2013

Penguins are a remarkable group of birds, with the 18 extant species living in diverse climatic zones from the tropics to Antarctica. The timing of the origin of these extant penguins remains controversial. Previous studies based on DNA sequences and fossil records have suggested widely differing times for the origin of the group. This has given rise to widely differing biogeographic narratives about their evolution. To resolve this problem, we sequenced five introns from 11 species representing all genera of living penguins. Using these data and other available DNA sequences, together with the ages of multiple penguin fossils to calibrate the molecular clock, we estimated the age of the most recent common ancestor of extant penguins to be 20.4 Myr (17.0–23.8 Myr). This time is half of the previous estimates based on molecular sequence data. Our results suggest that most of the major groups of extant penguins diverged 11–16 Ma. This overlaps with the sharp decline in Antarctic temperatures that began approximately 12 Ma, suggesting a possible relationship between climate change and penguin evolution.
A trapezoidal rule error bound unifying the Euler–Maclaurin formula and geometric convergence for periodic functions
Authors: Javed Mohsin , Trefethen Lloyd N.
Published: November 2013

The error in the trapezoidal rule quadrature formula can be attributed to discretization in the interior and non-periodicity at the boundary. Using a contour integral, we derive a unified bound for the combined error from both sources for analytic integrands. The bound gives the Euler–Maclaurin formula in one limit and the geometric convergence of the trapezoidal rule for periodic analytic functions in another. Similar results are also given for the midpoint rule.
Modelling elastic structures with strong nonlinearities with application to stick–slip friction
Authors: Szalai Robert
Published: November 2013

An exact transformation method is introduced that reduces the governing equations of a continuum structure coupled to strong nonlinearities to a low-dimensional equation with memory. The method is general and well suited to problems with isolated discontinuities such as friction and impact at point contact. It is assumed that the structure is composed of two parts: a continuum but linear structure and finitely many discrete but strong nonlinearities acting at various contact points of the elastic structure. The localized nonlinearities include discontinuities, e.g. the Coulomb friction law. Despite the discontinuities in the model, we demonstrate that contact forces are Lipschitz continuous in time at the onset of sticking for certain classes of structures. The general formalism is illustrated for a continuum elastic body coupled to a Coulomb-like friction model.
Female rhesus macaques discriminate unfamiliar paternal sisters in playback experiments: support for acoustic phenotype matching
Authors: Pfefferle Dana , Ruiz-Lambides Angelina V. , Widdig Anja
Published: November 2013

Widespread evidence exists that when relatives live together, kinship plays a central role in shaping the evolution of social behaviour. Previous studies showed that female rhesus macaques (Macaca mulatta) recognize familiar maternal kin using vocal cues. Recognizing paternal kin might, however, be more difficult as rhesus females mate promiscuously during the possible conception period, most probably concealing paternity. Behavioural observations indicate that semi free-ranging female rhesus macaques prefer to associate with their paternal half-sisters in comparison to unrelated females within the same group, particularly when born within the same age cohort. However, the cues and mechanism/s used in paternal kin discrimination remain under debate. Here, we investigated whether female rhesus macaques use the acoustic modality to discriminate between paternal half-sisters and non-kin, and tested familiarity and phenotype matching as the underlying mechanisms. We found that test females responded more often to calls of paternal half-sisters compared with calls of unrelated females, and that this discrimination ability was independent of the level of familiarity between callers and test females, which provides, to our knowledge, the first evidence for acoustic phenotype matching. Our study strengthens the evidence that female rhesus macaques can recognize their paternal kin, and that vocalizations are used as a cue.
Correlations in the population structure of music, genes and language
Authors: Brown Steven , Savage Patrick E. , Ko Albert Min-Shan , Stoneking Mark , Ko Ying-Chin , Loo Jun-Hun , Trejaut Jean A.
Published: November 2013

We present, to our knowledge, the first quantitative evidence that music and genes may have coevolved by demonstrating significant correlations between traditional group-level folk songs and mitochondrial DNA variation among nine indigenous populations of Taiwan. These correlations were of comparable magnitude to those between language and genes for the same populations, although music and language were not significantly correlated with one another. An examination of population structure for genetics showed stronger parallels to music than to language. Overall, the results suggest that music might have a sufficient time-depth to retrace ancient population movements and, additionally, that it might be capturing different aspects of population history than language. Music may therefore have the potential to serve as a novel marker of human migrations to complement genes, language and other markers.
Social status and personality: stability in social state can promote consistency of behavioural responses
Authors: Favati Anna , Leimar Olof , Radesäter Tommy , Løvlie Hanne
Published: November 2013

Stability of ‘state’ has been suggested as an underlying factor explaining behavioural stability and animal personality (i.e. variation among, and consistency within individuals in behavioural responses), but the possibility that stable social relationships represent such states remains unexplored. Here, we investigated the influence of social status on the expression and consistency of behaviours by experimentally changing social status between repeated personality assays. We used male domestic fowl (
Gallus gallus domesticus
), a social species that forms relatively stable dominance hierarchies, and showed that behavioural responses were strongly affected by social status, but also by individual characteristics. The level of vigilance, activity and exploration changed with social status, whereas boldness appeared as a stable individual property, independent of status. Furthermore, variation in vocalization predicted future social status, indicating that individual behaviours can both be a predictor and a consequence of social status, depending on the aspect in focus. Our results illustrate that social states contribute to both variation and stability in behavioural responses, and should therefore be taken into account when investigating and interpreting variation in personality.
Disentangling multiple drivers of pollination in a landscape-scale experiment
Authors: Schüepp Christof , Herzog Felix , Entling Martin H.
Published: November 2013

Animal pollination is essential for the reproductive success of many wild and crop plants. Loss and isolation of (semi-)natural habitats in agricultural landscapes can cause declines of plants and pollinators and endanger pollination services. We investigated the independent effects of these drivers on pollination of young cherry trees in a landscape-scale experiment. We included (i) isolation of study trees from other cherry trees (up to 350 m), (ii) the amount of cherry trees in the landscape, (iii) the isolation from other woody habitats (up to 200 m) and (iv) the amount of woody habitats providing nesting and floral resources for pollinators. At the local scale, we considered effects of (v) cherry flower density and (vi) heterospecific flower density. Pollinators visited flowers more often in landscapes with high amount of woody habitat and at sites with lower isolation from the next cherry tree. Fruit set was reduced by isolation from the next cherry tree and by a high local density of heterospecific flowers but did not directly depend on pollinator visitation. These results reveal the importance of considering the plant's need for conspecific pollen and its pollen competition with co-flowering species rather than focusing only on pollinators’ habitat requirements and flower visitation. It proved to be important to disentangle habitat isolation from habitat loss, local from landscape-scale effects, and direct effects of pollen availability on fruit set from indirect effects via pollinator visitation to understand the delivery of an agriculturally important ecosystem service.
Sexual conflict over mating in red-sided garter snakes (Thamnophis sirtalis) as indicated by experimental manipulation of genitalia
Authors: Friesen Christopher R. , Uhrig Emily J. , Squire Mattie K. , Mason Robert T. , Brennan Patricia L. R.
Published: November 2013

Sexual conflict over mating can result in sex-specific morphologies and behaviours that allow each sex to exert control over the outcome of reproduction. Genital traits, in particular, are often directly involved in conflict interactions. Via genital manipulation, we experimentally investigated whether genital traits in red-sided garter snakes influence copulation duration and formation of a copulatory plug. The hemipenes of male red-sided garter snakes have a large basal spine that inserts into the female cloaca during mating. We ablated the spine and found that males were still capable of copulation but copulation duration was much shorter and copulatory plugs were smaller than those produced by intact males. We also anaesthetized the female cloacal region and found that anaesthetized females copulated longer than control females, suggesting that female cloacal and vaginal contractions play a role in controlling copulation duration. Both results, combined with known aspects of the breeding biology of red-sided garter snakes, strongly support the idea that sexual conflict is involved in mating interactions in this species. Our results demonstrate the complex interactions among male and female traits generated by coevolutionary processes in a wild population. Such complexity highlights the importance of simultaneous examination of male and female traits.
Expression of a bacterial catalase in a strictly anaerobic methanogen significantly increases tolerance to hydrogen peroxide but not oxygen
Authors: Jennings Matthew E. , Schaff Cody W. , Horne Alexandra J. , Lessner Faith H. , Lessner Daniel J.
Published: November 2013

Haem-dependent catalase is an antioxidant enzyme that degrades H2O2, producing H2O and O2, and is common in aerobes. Catalase is present in some strictly anaerobic methane-producing archaea (methanogens), but the importance of catalase to the antioxidant system of methanogens is poorly understood. We report here that a survey of the sequenced genomes of methanogens revealed that the majority of species lack genes encoding catalase. Moreover, Methanosarcina acetivorans is a methanogen capable of synthesizing haem and encodes haem-dependent catalase in its genome; yet, Methanosarcina acetivorans cells lack detectable catalase activity. However, inducible expression of the haem-dependent catalase from Escherichia coli (EcKatG) in the chromosome of Methanosarcina acetivorans resulted in a 100-fold increase in the endogenous catalase activity compared with uninduced cells. The increased catalase activity conferred a 10-fold increase in the resistance of EcKatG-induced cells to H2O2 compared with uninduced cells. The EcKatG-induced cells were also able to grow when exposed to levels of H2O2 that inhibited or killed uninduced cells. However, despite the significant increase in catalase activity, growth studies revealed that EcKatG-induced cells did not exhibit increased tolerance to O2 compared with uninduced cells. These results support the lack of catalase in the majority of methanogens, since methanogens are more likely to encounter O2 rather than high concentrations of H2O2 in the natural environment. Catalase appears to be a minor component of the antioxidant system in methanogens, even those that are aerotolerant, including Methanosarcina acetivorans. Importantly, the experimental approach used here demonstrated the feasibility of engineering beneficial traits, such as H2O2 tolerance, in methanogens.
Streptococcus suis DNase SsnA contributes to degradation of neutrophil extracellular traps (NETs) and evasion of NET-mediated antimicrobial activity
Authors: de Buhr Nicole , Neumann Ariane , Jerjomiceva Natalja , von Köckritz-Blickwede Maren , Baums Christoph G.
Published: November 2013

Streptococcus suisis an important cause of different pathologies in pigs and humans, most importantly fibrinosuppurative meningitis. Tissue infected with this pathogen is substantially infiltrated with neutrophils, but the function of neutrophil extracellular traps (NETs) - a more recently discovered antimicrobial strategy of neutrophils - in host defence againstStrep. suishas not been investigated. The objective of this work was to investigate the interaction ofStrep. suiswith NETsin vitro.Strep. suisinduced NET formation in porcine neutrophils and was entrapped but not killed by those NETs. As the amount of NETs decreased over time, we hypothesized that a known extracellular DNase ofStrep. suisdegrades NETs. Though this nuclease was originally designatedStrep. suis-secreted nuclease A (SsnA), this work demonstrated surface association in accordance with an LPXTG cell wall anchor motif and partial release into the supernatant. Confirming our hypothesis, an isogenicssnA mutant was significantly attenuated in NET degradation and in protection against the antimicrobial activity of NETs as determined in assays with phorbol myristate acetate (PMA)-stimulated human neutrophils. Though assays with PMA-stimulated porcine neutrophils suggested that SsnA also degrades porcine NETs, phenotypic differences between wt and the isogenicssnA mutant were less distinct. As SsnA expression was crucial for neither growthin vitronor for survival in porcine or human blood, the results indicated that SsnA is the first specific NET evasion factor to be identified inStrep. suis.
Two Herbivore-Induced Cytochrome P450 Enzymes CYP79D6 and CYP79D7 Catalyze the Formation of Volatile Aldoximes Involved in Poplar Defense
Authors: Irmisch Sandra , Clavijo McCormick Andrea , Boeckler G. Andreas , Schmidt Axel , Reichelt Michael , Schneider Bernd , Block Katja , Schnitzler Jörg-Peter , Gershenzon Jonathan , Unsicker Sybille B. , Köllner Tobias G.
Published: November 2013

Aldoximes are known as floral and vegetative plant volatiles but also as biosynthetic intermediates for other plant defense compounds. While the cytochrome P450 monooxygenases (CYP) from the CYP79 family forming aldoximes as biosynthetic intermediates have been intensively studied, little is known about the enzymology of volatile aldoxime formation. We characterized two P450 enzymes, CYP79D6v3 and CYP79D7v2, which are involved in herbivore-induced aldoxime formation in western balsam poplar (Populus trichocarpa). Heterologous expression in Saccharomyces cerevisiae revealed that both enzymes produce a mixture of different aldoximes. Knockdown lines of CYP79D6/7 in gray poplar (Populus × canescens) exhibited a decreased emission of aldoximes, nitriles, and alcohols, emphasizing that the CYP79s catalyze the first step in the formation of a complex volatile blend. Aldoxime emission was found to be restricted to herbivore-damaged leaves and is closely correlated with CYP79D6 and CYP79D7 gene expression. The semi-volatile phenylacetaldoxime decreased survival and weight gain of gypsy moth (Lymantria dispar) caterpillars, suggesting that aldoximes may be involved in direct defense. The wide distribution of volatile aldoximes throughout the plant kingdom and the presence of CYP79 genes in all sequenced genomes of angiosperms suggest that volatile formation mediated by CYP79s is a general phenomenon in the plant kingdom.
Maternal input to children with specific language impairment during shared book reading: is mothers’ language in tune with their children's production?
Authors: Majorano Marinella , Lavelli Manuela
Published: November 2013

Background

The literature on input addressed to children with specific language impairment (SLI) has shown contrasting results on the role that parents assume during conversational interactions. Some studies have shown that parents compensate for the child's linguistic limitations. In contrast, other studies have indicated that mothers are able to adjust their communication in response to their children's language characteristics.

Aims

To assess the ‘closeness of fit’ between maternal input and child language profiles in children with SLI during shared book reading. To achieve this aim, the individual linguistic features of a group of children with SLI and their mothers were compared with those of two typically developing (TD) groups and the ‘distances’ (i.e., the differences between the mother's and her child's linguistic indices) within each dyad were compared.

Method & Procedures

Three groups of children with their mothers participated in the study: 14 children with expressive SLI, 14 language age‐matched TD children (LA‐matched group), and 14 chronological age‐matched TD children (CA‐matched group). Each mother–child dyad was videotaped during two weekly sessions of shared book reading, at home. All sessions were entirely transcribed. For each session, the following indices were then considered: whole‐word phonological indices, grammatical categories and lexical indices for types and tokens, and the distance between the mother's and the child's linguistic indices within individual dyads.

Outcomes & Results

Analysis of the differences between phonological, lexical and morphosyntactic characteristics of the mothers’ and children's language indicated that both children with SLI and their mothers produced adjectives and adverbs with lower phonological complexity and with higher frequency of use compared with the CA‐matched group, and nouns with lower frequency of use and higher age of acquisition compared with the LA‐matched group. In addition, individual dyads within the SLI group displayed reduced distances between linguistic indices produced by the mother and child compared with dyads within the CA‐matched group.

Conclusions & Implications

On the whole these findings suggest that mothers of children with SLI are able to tune their language to their children's linguistic limitations. These findings may contribute to improving early intervention programmes with children with SLI by focusing on the mother–child interaction during shared book reading.
Thalidomide‐induced angiopoietin 2, Notch1 and Dll4 downregulation under hypoxic condition in tissues with gastrointestinal vascular malformation and human umbilical vein endothelial cells
Authors: Feng Qian , Tan Hong Hong , Ge Zhi Zheng , Gao Yun Jie , Chen Hui Min , Xiao Shu Dong
Published: November 2013

Objective

To determine the pathogenesis of gastrointestinal vascular malformation (GIVM) and the mechanism of thalidomide in treating GIVM by evaluating the expression of angiopoietin 2 (Ang2), Notch1, delta‐like ligand 4 (Dll4) and hypoxia inducible factor 1α (Hif‐1α).

Methods

Data of 10 patients with histology‐confirmed GIVM were reviewed. Immunohistochemistry of surgically resected GIVM tissues and the adjacent mucosa of the patients and normal tissues from those who had undergone colonoscopy for health examination was performed to examine the expressions of Ang2, Notch1, Dll4 and Hif‐1α. In addition, in vitro effect of thalidomide on Ang2, Notch1 and Dll4 in human umbilical vein endothelial cells (HUVEC) and on HUVEC proliferation was also investigated during normoxic and hypoxic conditions.

Results

GIVM lesions presented as tortuous, dilated arterioles, venules and capillaries. Ang2, Notch1 and Dll4 showed strong immunoreactivity in the cytoplasm and nuclei of GIVM lesions but negative or weak positivity in the intestinal mucosa of the adjacent tissues and normal mucosa. Under hypoxic condition the expressions of Hif‐1α, Ang2, Notch1 and Dll4 were upregulated and the tube formation was more abundant with a greater diameter of tubes. Moreover, thalidomide downregulated their expression in HUVEC and HUVEC proliferation decreased in a concentration‐dependent manner under both hypoxic and normoxic conditions.

Conclusion

Ang2, Notch1, Dll4 and Hif‐1α may play an important role in the pathogenesis of GIVM and may be potential targets of thalidomide in the treatment of the disease.
Species and hybrid identification of sturgeon caviar: a new molecular approach to detect illegal trade
Authors: Boscari E. , Barmintseva A. , Pujolar J. M. , Doukakis P. , Mugue N. , Congiu L.
Published: November 2013

Overexploitation of wild populations due to the high economic value of caviar has driven sturgeons to near extinction. The high prices commanded by caviar on world markets have made it a magnet for illegal and fraudulent caviar trade, often involving low‐value farmed caviar being sold as top‐quality caviar. We present a new molecular approach for the identification of pure sturgeon species and hybrids that are among the most commercialized species in Europe and North America. Our test is based on the discovery of species‐specific single nucleotide polymorphisms (SNPs) in the ribosomal protein S7, supplemented with the Vimentin gene and the mitochondrial D‐loop. Test validations performed in 702 specimens of target and nontarget sturgeon species demonstrated a 100% identification success for Acipenser naccarii, A. fulvescens, A. stellatus, A. sinensis and A. transmontanus. In addition to species identification, our approach allows the identification of Bester and AL hybrids, two of the most economically important hybrids in the world, with 80% and 100% success, respectively. Moreover, the approach has the potential to identify many other existing sturgeon hybrids. The development of a standardized sturgeon identification tool will directly benefit trade law enforcement, providing the tools to monitor and regulate the legal trade of caviar and protect sturgeon stocks from illicit producers and traders, hence contributing to safeguarding this group of heavily threatened species.
Relationship between knee alignment and radiographic markers of osteoarthritis: a cross‐sectional study from a Korean population
Authors: Im Gun‐Il , Kim Min‐Kyu , Lee Sung‐Hyun
Published: November 2013

Aim

The purpose of this paper was to investigate the relationship between static varus knee alignment and the radiographic markers of knee osteoarthritis (OA), including joint space narrowing (JSN) and Kellgren–Lawrence (K‐L) grading scale.

Method

Knee alignment was measured by mechanical axis from weight‐bearing anteroposterior (AP) radiographs of 251 symptomatic knees with radiological signs of OA (K‐L grade ≥ 1). Linear correlation between knee varus alignment and variables, including joint space width (JSW) and K‐L grades of tibiofemoral (TF) joint in extension or 45° flexion and patellofemoral (PF) joints were investigated. Multiple linear regression analyses were also performed to examine independent associations between varus knee alignment and JSW. Analysis of covariance (ancova) was performed to analyze the difference in knee alignment among K‐L grade category groups adjusted for physical variables.

Results

Varus knee alignment was negatively correlated with JSW of medial TF joint in extension AP (r = –0.460, P = 0.0001) and 45° flexion PA views (r = –0.476, P = 0.0001) and PF JSN (r = –0.168, P = 0.008). Multiple linear regression analysis adjusted for physical variables showed that the varus knee alignment was negatively associated with the JSW of medial TF joint in extension AP (P = 0.0001) and 45° flexion PA view (P = 0.0001). ancova adjusted for physical variables showed that knees in K‐L grade 4 had significantly greater varus alignment than those in K‐L grades 1–3 in AP (P = 0.0001), 45° flexion PA view (P = 0.0001), and PF joint (P = 0.0001~0.001).

Conclusion

Varus knee alignment is associated with the radiographic measures of knee OA severity.
Modest Long‐Term Ethanol Consumption Affects Expression of Neurotransmitter Receptor Genes in the Rat Nucleus Accumbens
Authors: Jonsson Susanne , Ericson Mia , Söderpalm Bo
Published: November 2013

Background

Over 100 million people worldwide are affected by alcohol use disorders. These conditions usually take years to develop where an initial, voluntary consumption is gradually replaced by a compulsive intake of alcohol. The exact mechanisms behind this transition remain unknown. However, ethanol (EtOH) is known to interact with several neurotransmitters and receptors in the central nervous system, and chronic EtOH consumption causes alterations in these neurotransmitter systems, proposed to contribute to the development of dependence. This study aimed to repeat previous findings that animals after long‐term voluntary EtOH consumption spontaneously increase their intake. That the initial encounter with EtOH causes an elevation of dopamine in the nucleus accumbens (nAc), inducing feelings of well‐being and creating an incentive to continue the behavior, has been repeatedly reported in both animals and humans. The effects of chronic EtOH consumption on this region are not as well investigated.

Methods

We examined both long‐term EtOH consumption behavior and its consequences on expression of neurotransmitter‐related genes in the nAc of the Wistar rat using quantitative polymerase chain reaction.

Results

In general, the EtOH consumption of the animals in this study was modest with an average intake of 0.9 g/kg/d, and only 1 of the 24 rats consuming EtOH for 10 months drastically increased its intake in line with the results of Wolffgramm and Heyne (1995). Expression of the genes for dopamine receptor 2, μ‐opioid receptor, and somatostatin receptor 4 were down‐regulated in animals after 2 and/or 4, but not 10, months of EtOH consumption.

Conclusions

Chronic consumption even of modest amounts of alcohol seems to affect regulation of expression of these genes, possibly leading to changes in neurotransmitter signaling. Studies are ongoing to investigate whether these alterations are specific for the nAc.
Is place of birth associated with mode of birth? The effect of hospital on caesarean section rates in a public metropolitan health service
Authors: Biro Mary A. , Knight Michelle , Wallace Euan , Papacostas Kerrie , East Christine
Published: November 2013

Background

The effects of place of birth on birth outcomes have been examined in several studies both locally and internationally. However, none has examined the impact on caesarean section rates of different level maternity hospitals operating within the one health service. This study aimed to examine the impact of place of (Hospital level 6; 4–5 or 4) on birth outcomes in a large metropolitan health service in Victoria.

Methods

A cross‐sectional study utilising data on births to low‐risk first‐time mothers during 2010–2011. Data were obtained from the Birthing Outcome System (BOS) database of Monash Health. Unadjusted and adjusted analyses were undertaken using logistic regression to examine the association between place of birth and caesarean section.

Results

In this group of low‐risk nulliparae, there was evidence of a significant association between place of birth and caesarean section. The lower the acuity of the hospital, the higher the odds for the caesarean section. Compared with the level 6 hospital, the AdjOR for caesarean section at the level 4 hospital was 1.81 (95% CI: 1.37–2.41) and at the level 4–5 hospital, 1.30 (95% CI: 1.0–1.7).

Conclusions

Low‐risk nulliparae in spontaneous labour giving birth at the level 4 hospital in this health service are at significantly increased risk of caesarean section. This may have implications for the organisation and resource management of other level 4 public maternity units. Care in a tertiary (level 6) service may not necessarily equate to the higher rates of intervention reported by others.
Effect of high‐dose paracetamol on needle procedures in children with cancer – a RCT
Authors: Hedén L , von Essen L , Ljungman G
Published: November 2013

Aim

The aim was to investigate whether children experience less pain, fear and/or distress when they receive high‐dose paracetamol compared with placebo, using a needle insertion in a subcutaneously implanted intravenous port as a model.

Methods

Fifty‐one children ranging from 1 to 18 years of age being treated in a paediatric oncology setting were included consecutively when undergoing routine needle insertion into a subcutaneously implanted intravenous port. All children were subjected to one needle insertion following topical anaesthetic (EMLA) application in this double‐blind, placebo‐controlled RCT, comparing orally administered paracetamol (n = 24) 40 mg/kg body weight (max 2000 mg) with placebo (n = 27). The patients' pain, fear and distress were reported by parents, nurses and children (≥7 years of age) using 0‐ to 100‐mm visual analogue scales (VAS). In addition, pain observation, procedure time and cortisol reduction were assessed.

Results

No differences between the paracetamol and the placebo group were found with respect to demographic characteristics. According to VAS reports, paracetamol did not reduce pain, fear and distress compared with placebo. Pain observation, cortisol reduction and procedure time did not differ between the study groups.

Conclusion

Paracetamol provides no additive effect in reducing pain, fear and distress when combined with topical anaesthesia in children undergoing port needle insertion.