bluuebunny/crossref_metadata_2025 huggingface dataset:
Virulence and inoculum density‐dependent interactions between clubroot resistant canola (Brassica napus) and Plasmodiophora brassicae
Authors: Hwang S. F. , Strelkov S. E. , Ahmed H. U. , Manolii V. P. , Zhou Q. , Fu H. , Turnbull G. , Fredua‐Agyeman R. , Feindel D.
Published: February 2017

To mitigate the impact and dissemination of clubroot in western Canada, canola (Brassica napus) producers have relied on clubroot resistance traits. However, in 2013 and 2014, new strains of the clubroot pathogen, Plasmodiophora brassicae, emerged that are virulent on most clubroot‐resistant (CR) canola genotypes. Novel strains of the pathogen were inoculated onto two susceptible canola cultivars, one resistant line and six CR cultivars. Although all cultivars/lines showed a susceptible response to inoculation with the new strains of P. brassicae, the severity of disease reaction, root hair infection rates and the amount of P. brassicae DNA present in each canola genotype varied depending on the strain. In addition, the effect of inoculum density on disease severity and gall formation was recorded for one of these new strains on a universally susceptible Chinese cabbage cultivar and one susceptible and 10 resistant canola genotypes. Although root galls were observed at an inoculum density of 103 spores per mL of soil, clear differentiation of susceptible and resistant reactions among canola cultivars/lines was not observed until the inoculum density reached 105 spores mL−1. At a spore density of 106 spores mL−1 and above, all cultivars/lines developed susceptible reactions, although there was some differentiation in the degree of reaction. This study shows the potential to develop a unique disease profile for emergent clubroot pathotypes and shows a useful range of spore densities at which to study new P. brassicae strains.
Learning processes underlying avoidance of negative outcomes
Authors: Andreatta Marta , Michelmann Sebastian , Pauli Paul , Hewig Johannes
Published: February 2017

Successful avoidance of a threatening event may negatively reinforce the behavior due to activation of brain structures involved in reward processing. Here, we further investigated the learning‐related properties of avoidance using feedback‐related negativity (FRN). The FRN is modulated by violations of an intended outcome (prediction error, PE), that is, the bigger the difference between intended and actual outcome, the larger the FRN amplitude is. Twenty‐eight participants underwent an operant conditioning paradigm, in which a behavior (button press) allowed them to avoid a painful electric shock. During two learning blocks, participants could avoid an electric shock in 80% of the trials by pressing one button (avoidance button), or by not pressing another button (punishment button). After learning, participants underwent two test blocks, which were identical to the learning ones except that no shocks were delivered. Participants pressed the avoidance button more often than the punishment button. Importantly, response frequency increased throughout the learning blocks but it did not decrease during the test blocks, indicating impaired extinction and/or habit formation. In line with a PE account, FRN amplitude to negative feedback after correct responses (i.e., unexpected punishment) was significantly larger than to positive feedback (i.e., expected omission of punishment), and it increased throughout the blocks. Highly anxious individuals showed equal FRN amplitudes to negative and positive feedback, suggesting impaired discrimination. These results confirm the role of negative reinforcement in motivating behavior and learning, and reveal important differences between high and low anxious individuals in the processing of prediction errors.
Urine levels of luteinizing hormone as predictor of the period of ovulation for advantage of timed‐artificial insemination in murrah buffalo (Bubalus bubalis)
Authors: Selvam RM , Singh D , Akbarsha MA , Archunan G
Published: February 2017

Contents

Assessment of urine levels of luteinizing hormone (LH) for predicting the reproductive status of animals is in practice. The aim of this study was to predict the period of ovulation based on the urine levels of LH for timed‐artificial insemination to increase the conception rate in buffaloes, which are naturally silent‐oestrous animals. Level of LH in urine was assessed using ELISA, and a cut‐off LH concentration for prediction of ovulation period was obtained using receiver operating characteristic analysis. Artificial insemination was performed before‐ and after ‐positive prediction of ovulation period adopting this method, and the rates of conception were assessed. Urine LH level of 105 mIU/ml (n = 14) was derived as a cut‐off concentration which predicts the ovulation period. The buffaloes in the positively predicted group (day 1 or 2) inseminated via intracervical route had an increase in the conception rate (83.33%); however, the insemination in the before‐positive‐prediction group resulted in poor conception rates (day 0; 16.66%) compared to that of the naturally inseminated group (day 0; 75.0%). In conclusion, the urinary LH would possibly be a fairly reliable predictor of the ovulation period. The day when cut‐off LH concentration is obtained may be taken as the most favourable time for artificial insemination, so as to attain a much better rate of conception in the buffalo.
Organizational stressors and basic psychological needs: The mediating role of athletes' appraisal mechanisms
Authors: Bartholomew K. J. , Arnold R. , Hampson R. J. , Fletcher D.
Published: February 2017

This article reports the first study to quantitatively examine the relationships between the demands encountered by athletes that are associated with the organization within which they are operating, cognitive appraisals, and basic psychological need experiences. Three hundred and fifteen high‐level British athletes completed a multisection questionnaire which assessed each of the aforementioned constructs. A series of path analyses provided valuable insight into the way in which the three dimensions (ie, frequency, intensity, and duration) of five organizational stressor categories were evaluated by athletes and, in turn, how such threat or challenge appraisals predicted feelings of need satisfaction and need frustration. Moreover, cognitive stress appraisals were found to mediate the relationship between organizational stressors and psychological need experiences. The role of secondary control appraisals was also explored and found to mediate the relationship between primary cognitive appraisals and basic psychological need experiences. Study limitations, proposed future research directions, and the implications of the findings for applied practitioners are discussed.
Longitudinal associations among adolescents’ organized activity involvement and sociopolitical values
Authors: Oosterhoff Benjamin , Ferris Kaitlyn A. , Palmer Cara A. , Metzger Aaron
Published: February 2017

Organized activities represent a potentially important context for the development of adolescent sociopolitical values, but few studies have examined longitudinal associations between youths’ sociopolitical values and activity involvement. Adolescents (N = 299, Time 1 Mage = 15.49, SD = .93, 62% female) reported on their organized activity involvement (volunteering, church, sports, arts/music, school and community clubs) and sociopolitical values (materialism, social dominance, authoritarianism, patriotism, spirituality) at baseline and one year later. Greater involvement in arts/music predicted lower spirituality and patriotism one year later and greater involvement in church predicted higher levels of spirituality and lower levels of social dominance one year later. Higher levels of materialism predicted less involvement in arts/music one year later and higher social dominance values predicted less involvement in volunteering one year later. Findings support the importance of organized activities in sociopolitical development, and suggest that sociopolitical values may guide decisions concerning future organized activity involvement.
INTRAOPERATIVE IMAGE NAVIGATION: EXPERIMENTAL STUDY OF THE FEASIBILITY AND SURGEON PREFERENCE BETWEEN A STERILE ENCASED NINTENDO WIITM REMOTE AND STANDARD WIRELESS COMPUTER MOUSE
Authors: Appleby Ryan , zur Linden Alex , Sears William
Published: February 2017

Diagnostic imaging plays an important role in the operating room, providing surgeons with a reference and surgical plan. Surgeon autonomy in the operating room has been suggested to decrease errors that stem from communication mistakes. A standard computer mouse was compared to a wireless remote‐control style controller for computer game consoles (Wiimote) for the navigation of diagnostic imaging studies by sterile personnel in this prospective survey study. Participants were recruited from a cohort of residents and faculty that use the surgical suites at our institution. Outcome assessments were based on survey data completed by study participants following each use of either the mouse or Wiimote, and compared using an analysis of variance. The mouse was significantly preferred by the study participants in the categories of handling, accuracy and efficiency, and overall satisfaction (P <0.05). The mouse was preferred to both the Wiimote and to no device, when participants were asked to rank options for image navigation. This indicates the need for the implementation of intraoperative image navigation devices, to increase surgeon autonomy in the operating room.
Dynamics of above‐ground and below‐ground biomass of Rumex crispus, Rumex obtusifolius and the new weedy species Rumex hybrid cv. OK‐2 (R. patientia x R. tianschanicus) in the seeding year
Authors: Hujerová R , Pavlů L , Pavlů V , Hejcman M , Gaisler J
Published: February 2017

Docks can be serious weeds of arable land and permanent grasslands where they can persist through well‐established root systems. A Rumex hybrid (R. patientia x R. tianschanicus; cv. OK‐2, Uteusha) has been planted as a forage and energy crop since 2001 in Czechia and has now become a new weed species. As its ecological characteristics are unknown, there is a need for improved knowledge for developing control measures and strategies. In 2010 and 2011, we performed a tube pot experiment to investigate above‐ground and below‐ground biomass growth dynamics and below‐ground biomass allocation of Rumex OK‐2. We compared the hybrid with Rumex crispus and Rumex obtusifolius during the vegetation season in the seeding year. Above‐ground and below‐ground biomass of Rumex species tended to increase from July to September. In the seeding year, flowering was recorded only for one plant of Rumex OK‐2 and 27.5% of R. obtusifolius plants, whereas R. crispus did not flower. The proportion of below‐ground biomass of Rumex species in the upper 30 cm was about 70–80%. The growth dynamics and allocation of below‐ground biomass of Rumex OK‐2 were more like R. crispus than to R. obtusifolius. These similarities indicate the potential of Rumex OK‐2 to become a troublesome weedy species, comparable with R. crispus.
The Effect of Urbanization and Economic Performance on Metropolitan Water Consumption: Theoretic Model and Evidence from Guangzhou of China
Authors: Gao Shaohui , He Yiming
Published: February 2017

This paper examines the effect of urbanization and economic performance on metropolitan water consumption in Guangzhou of China. We develop social and individual optimal models to reveal the impact of urbanization and economic performance on metropolitan water consumption. Based on aggregated annual data from 1949 to 2014, the empirical results from OLS and ARDL suggest that previous water consumption per capita, urbanization and GDP per capita each play vital roles impacting metropolitan water consumption per capita in Guangzhou.
New Zealand Students and ‘Cultures of Intoxication’
Authors: Hutton Fiona
Published: February 2017

The drinking practices of New Zealanders have been the subject of much concern, culminating in a report by the New Zealand Law Commission in 2010 which presented evidence-based recommendations for implementing effective alcohol policies in New Zealand. Within debates about alcohol consumption and drinking practices, New Zealand University students have been identified as a group of young people who drink more heavily than their peers, as well as suffering from more alcohol related harms.
The following discussion focuses on a group of eight university students, aged 18–19, some who were non- or light-drinkers, and their reflections on the cultures of intoxication that they negotiate, as well as their experiences of peer pressure. The aim of this article is to discuss the drinking and abstinence prac- tices of this group of New Zealand university students to explore how they interact with or resist contemporary cultures of intoxication in the particular context of university life. Eight qualitative, semi-structured interviews were thematically analysed and the themes: cultures of intoxication, peer pressure and inexperienced ‘drinking disasters’ are discussed. This paper critically ex- plores these key themes and discusses the New Zealand context in relation to the international literature about student drinking cultures (Hernandez, Leotini and Harley 2013; Romo 2012; Supski, Lindsay and Tanner 2016), including young people who are light or non-drinkers (Conroy and de Visser 2014; Nairn, Higgins, Thompson, Anderson and Fu 2007; Fry 2010; Herring, Bayley and Hurcombe 2014). The interviews identified an overarching New Zealand culture of intoxication, as well as more local cultures of intoxication, which students bring with them to a university setting.
Music Video and Online Social Media: A Case Study of the Discourse around Japanese Imagery in the New Zealand Indie Scene
Authors: Johnson Henry , Wilson Oli
Published: February 2017

This article offers original insights into the construction of musical meaning through an intensification and bricolage of postmodern discourse as a result of music video as online media. The discussion contributes to contemporary popular music scholarship by discussing the ‘Stranger People’ video by Dop- rah, an indie band from Christchurch, New Zealand, with particular focus on Japanese imagery and online social media. The significance of ‘Stranger People’ is that it received a great deal of international attention via social and other media. The article focuses on not only the means of video production, distri- bution, and consumption, but also the threads of cultural knowledge that are generated through media response to sight and sound and how this creates and re-creates meaning for fans and artists alike. The video serves as a particularly useful case for acknowledging and analysing the extent to which Japanese pop culture has become enmeshed in global cultural flows, and as a site for critical discussion on the localised and creative response to Japanese cultural flows.
The Politics of Location: Being a Native Anthropologist among Western Interlocutors in India
Authors: Ganguly Tuhina
Published: February 2017

This paper examines the politics of doing fieldwork as a ‘native’ i.e. Indian anthropologist among Western interlocutors in India. Focusing on the inter-relations between the Indian anthropologist and (predominantly) Western participants, this shows the complex nature of insider/outsider and native/Western location(s). While pointing out the multiple and shifting locations inhabited by the author and the interlocutors, the paper also highlights the ways in which such fluidity negotiates with the construct of the authentic native. The fixity of the mythical figure of the native made it difficult for the author to claim undisputed insidership. However, in critiquing the construction of the native as a fixed, immobile category, the author is nevertheless mindful that counter-constructions of the native as hybrid and hypermobile overlook the privileged position of postcolonial academics. Ultimately, the paper argues that acknowledging the specificities of one’s location shatters the myth of the native as a singular category.
Longing for Childhood Times in the New Zealand Bush: Nostalgia, Antimodernism, and the Deforested Landscape in the Writing of Elsie K. Morton
Authors: Boyle Cameron John
Published: February 2017

This paper draws on articles published in the New Zealand Herald between 1914 and 1933 by the writer and journalist Elsie K. Morton to demonstrate how nostalgia for childhood experiences in the forest, or the bush, as it is labelled colloquially, have acted as an antimodern response to and critique of defor- estation in New Zealand. Morton’s articles are situated within the wider body of cultural antimodernism in New Zealand, locating them after the antimod- ern literature of Maoriland in the late nineteenth century and early twentieth century, but before the antimodern writing of several prominent authors who published their works in the 1930s and 1940s. The author makes the argument that the bush landscape is central to the expression of antimodernism as a response to the modernisation of New Zealand.
Dangerous Remains: Towards a History of Tapu
Authors: Sissons Jeffrey
Published: February 2017

The historical and cultural focus of this article is a connected sequence of rites performed by and on behalf of Maori kin groups in the mid-19th century aimed at polluting sacred groves (wāhi tapu). I argue that these rites were a logical sequel to others aimed at removing the tapu (sacredness) from chiefs prior to mass conversion to Christianity in the early 1840s. Both sets of rites sought the separation of gods from kin-groups, a process that entailed a transformation of the nature of tapu.
Response to 'Māori Indigeneity and Commodity Fetishism' by Steven Webster
Authors: McCormack Fiona
Published: February 2017

The utility of the concepts of use-value and exchange-value, compared with gift and commodity are debated via a comparison of Hawaiian and Māori fisheries, in this response to Webster's article in this issue of Sites.
Antiangiogenic cancer drug drives lymphangiogenic metastasis
Authors: Thomas Susan Napier
Published: February 2017

Tumor blood vessel–destroying cancer drug induces development of tumor lymphatics that contribute to treatment failure.
A Bioengineered Three-Dimensional Cell Culture Platform Integrated with Microfluidics To Address Antimicrobial Resistance in Tuberculosis
Authors: Bielecka Magdalena K. , Tezera Liku B. , Zmijan Robert , Drobniewski Francis , Zhang Xunli , Jayasinghe Suwan , Elkington Paul
Published: February 2017

Antimicrobial resistance presents one of the most significant threats to human health, with the emergence of totally drug-resistant organisms. We have combined bioengineering, genetically modified bacteria, longitudinal readouts, and fluidics to develop a transformative platform to address the drug development bottleneck, utilizing
Mycobacterium tuberculosis
as the model organism. We generated microspheres incorporating virulent reporter bacilli, primary human cells, and an extracellular matrix by using bioelectrospray methodology. Granulomas form within the three-dimensional matrix, and mycobacterial stress genes are upregulated. Pyrazinamide, a vital first-line antibiotic for treating human tuberculosis, kills
M. tuberculosis
in a three-dimensional culture but not in a standard two-dimensional culture or Middlebrook 7H9 broth, demonstrating that antibiotic sensitivity within microspheres reflects conditions in patients. We then performed pharmacokinetic modeling by combining the microsphere system with a microfluidic plate and demonstrated that we can model the effect of dynamic antibiotic concentrations on mycobacterial killing. The microsphere system is highly tractable, permitting variation of cell content, the extracellular matrix, sphere size, the infectious dose, and the surrounding medium with the potential to address a wide array of human infections and the threat of antimicrobial resistance.

IMPORTANCE
Antimicrobial resistance is a major global threat, and an emerging concept is that infection should be studied in the context of host immune cells. Tuberculosis is a chronic infection that kills over a million people every year and is becoming progressively more resistant to antibiotics. Recent major studies of shorter treatment or new vaccination approaches have not been successful, demonstrating that transformative technologies are required to control tuberculosis. We have developed an entirely new system to study the infection of host cells in a three-dimensional matrix by using bioengineering. We showed that antibiotics that work in patients are effective in this microsphere system but not in standard infection systems. We then combined microspheres with microfluidics to model drug concentration changes in patients and demonstrate the effect of increasing antibiotic concentrations on bacterial survival. This system can be widely applied to address the threat of antimicrobial resistance and develop new treatments.
Supporting shared decision-making for older people with multiple health and social care needs: a protocol for a realist synthesis to inform integrated care models
Authors: Bunn Frances , Goodman Claire , Manthorpe Jill , Durand Marie-Anne , Hodkinson Isabel , Rait Greta , Millac Paul , Davies Sue L , Russell Bridget , Wilson Patricia
Published: February 2017

Introduction

Including the patient or user perspective is a central organising principle of integrated care. Moreover, there is increasing recognition of the importance of strengthening relationships among patients, carers and practitioners, particularly for individuals receiving substantial health and care support, such as those with long-term or multiple conditions. The overall aims of this synthesis are to provide a context-relevant understanding of how models to facilitate shared decision-making (SDM) might work for older people with multiple health and care needs, and how they might be applied to integrated care models.

Methods and analysis

The synthesis draws on the principles of realist inquiry, to explain how, in what contexts and for whom, interventions that aim to strengthen SDM among older patients, carers and practitioners are effective. We will use an iterative, stakeholder-driven, three-phase approach. Phase 1: development of programme theory/theories that will be tested through a first scoping of the literature and consultation with key stakeholder groups; phase 2: systematic searches of the evidence to test and develop the theories identified in phase 1; phase 3: validation of programme theory/theories with a purposive sample of participants from phase 1. The synthesis will draw on prevailing theories such as candidacy, self-efficacy, personalisation and coproduction.

Ethics and dissemination

Ethics approval for the stakeholder interviews was obtained from the University of Hertfordshire ECDA (Ethics Committee with Delegated Authority), reference number HSK/SF/UH/02387. The propositions arising from this review will be used to develop recommendations about how to tailor SDM interventions to older people with complex health and social care needs in an integrated care setting.
Exploring the roots of unintended safety threats associated with the introduction of hospital ePrescribing systems and candidate avoidance and/or mitigation strategies: a qualitative study
Authors: Mozaffar Hajar , Cresswell Kathrin M , Williams Robin , Bates David W , Sheikh Aziz
Published: February 2017

Objective

Hospital electronic prescribing (ePrescribing) systems offer a wide range of patient safety benefits. Like other hospital health information technology interventions, however, they may also introduce new areas of risk. Despite recent advances in identifying these risks, the development and use of ePrescribing systems is still leading to numerous unintended consequences, which may undermine improvement and threaten patient safety. These negative consequences need to be analysed in the design, implementation and use of these systems. We therefore aimed to understand the roots of these reported threats and identify candidate avoidance/mitigation strategies.

Methods

We analysed a longitudinal, qualitative study of the implementation and adoption of ePrescribing systems in six English hospitals, each being conceptualised as a case study. Data included semistructured interviews, observations of implementation meetings and system use, and a collection of relevant documents. We analysed data first within and then across the case studies.

Results

Our dataset included 214 interviews, 24 observations and 18 documents. We developed a taxonomy of factors underlying unintended safety threats in: (1) suboptimal system design, including lack of support for complex medication administration regimens, lack of effective integration between different systems, and lack of effective automated decision support tools; (2) inappropriate use of systems—in particular, too much reliance on the system and introduction of workarounds; and (3) suboptimal implementation strategies resulting from partial roll-outs/dual systems and lack of appropriate training. We have identified a number of system and organisational strategies that could potentially avoid or reduce these risks.

Conclusions

Imperfections in the design, implementation and use of ePrescribing systems can give rise to unintended consequences, including safety threats. Hospitals and suppliers need to implement short- and long-term strategies in terms of the technology and organisation to minimise the unintended safety risks.
Novel analysis for large strains based on particle image velocimetry
Authors: Pinyol Núria M. , Alvarado Mauricio
Published: February 2017

Over the last few decades, the particle image velocimetry (PIV) technique has become an interesting tool used to measure displacements in the field of experimental mechanics. This paper presents a procedure to interpret PIV displacements, measured following an Eulerian scheme, with the purpose of providing accumulated displacements, velocities, accelerations, and strains on points representing physical particles. Strains are computed as the gradient of displacements. When compared with other standard procedures already published, the presented methodology is especially well suited to interpret large strains. The basis of the procedure is to map displacement increments measured through PIV analysis on the subset (or patch) centres into numerical particles that are defined as portions of the moving masses whose deformation is analyzed. The implementation of the method is explained in detail, highlighting its simplicity. The procedure can be used as a post-processor of currently available PIV software packages. The methodology is first applied to synthetic cases of rectangular samples in which known displacements are imposed and also to a sandy slope failure experiment involving large displacements. The method reproduces satisfactorily the recorded images.
An update to the Canadian range, abundance, and ploidy of Camelina spp. (Brassicaceae) east of the Rocky Mountains
Authors: Martin Sara L. , Smith Tyler W. , James Tracey , Shalabi Fatma , Kron Paul , Sauder Connie A.
Published: February 2017

The distribution and abundance of three Camelina species introduced to Canada is unknown, but critical for evaluating the risks associated with unconfined release of transgenic Camelina sativa (L.) Crantz (2n = 40). Furthermore, previous reports suggest Canadian populations of Camelina microcarpa Andrz. ex DC. vary for ploidy and ability to hybridize with C. sativa. We completed 8 weeks of field work in Alberta, Saskatchewan, Manitoba, southern Ontario, Quebec, and the Maritimes. We determined the ploidy composition of the populations found. We did not locate Camelina alyssum (Mill.) Thell., but located four sites with C. sativa and 34 with C. microcarpa. Eleven C. microcarpa populations were tetraploid (2n = 26, 1.00pg/2C) and 22 were hexaploid (2n = 40, 1.50pg/2C), while two populations were mixed. We examined material from botanical gardens and plant gene resource centres assessing total nuclear DNA content and completing chromosome counts for each species and cytotype identified, to determine whether tetraploid and hexaploid C. microcarpa were included in these collections. No tetraploid material was included in the C. microcarpa accessions received; however, a diploid (2n = 12, 0.54pg/2C) was found. Given the current geographic ranges, abundance, and chromosome counts of these species, the greatest risk of hybridization with transgenic C. sativa is from hexaploid C. microcarpa.
Near-infrared 2Eg → 4A2g and visible LMCT luminescence from a molecular bis-(tris(carbene)borate) manganese(IV) complex
Authors: Harris Joe P. , Reber Christian , Colmer Hannah E. , Jackson Timothy A. , Forshaw Adam P. , Smith Jeremy M. , Kinney R. Adam , Telser Joshua
Published: February 2017

The molecular bis-(tris(carbene)borate) manganese(IV) complex [{PhB(MeIm)3}2Mn](OTf)2 shows 2Eg → 4A2g luminescence at 828 nm in the solid state at 85 K; this wavelength is longer by approximately 100 nm than the wavelengths typically observed for manganese(IV) and chromium(III) doped solids and for molecular chromium(III) complexes. Weak luminescence is also observed from a LMCT excited state with an absorption maximum at 500 nm. This represents the first molecular manganese(IV) compound for which luminescence has been reported.
Broadband EM radiation amplification by means of a monochromatically driven two-level system
Authors: Soldatov Andrey V.
Published: February 2017

It is shown that a two-level quantum system possessing dipole moment operator with permanent non-equal diagonal matrix elements and driven by external semiclassical monochromatic high-frequency electromagnetic (EM) (laser) field can amplify EM radiation waves of much lower frequency.
FRACTAL ANALYSIS OF FLOW RESISTANCE IN TREE-LIKE BRANCHING NETWORKS WITH ROUGHENED MICROCHANNELS
Authors: YANG SHANSHAN , FU HUAHUA , YU BOMING
Published: February 2017

In this work, the effective average height of the roughness elements, the relative increase of the pressure gradients, the relative decrease of the permeability are derived based on the fractal geometry theory and technique for laminar flow through tree-like branching networks with roughened channels. The relationships among the effective average height, the structural parameters and pressure drops as well as permeability are studied. It is found that the total pressure drop across a tree-like branching network with roughened channels is increased by a factor of [Formula: see text], and the permeability for the network with roughened channels is decreased by a factor of [Formula: see text], where [Formula: see text] is the relative roughness of surfaces of channels, compared to those with smooth channels.
ROBUST TRADING OF IMPLIED SKEW
Authors: NADTOCHIY SERGEY , OBłÓJ JAN
Published: February 2017

In this paper, we present a method for constructing a (static) portfolio of co-maturing European options whose price sign is determined by the skewness level of the associated implied volatility. This property holds regardless of the validity of a specific model — i.e. the method is robust. The strategy is given explicitly and depends only on one’s beliefs about the future values of implied skewness, which is an observable market indicator. As such, our method allows the use of existing statistical tools to formulate the beliefs, providing a practical interpretation of the more abstract mathematical setting, in which the beliefs are understood as a family of probability measures. One of the applications of the results established herein is a method for trading one’s views on the future changes in implied skew, largely independently of other market factors. Another application of our results provides a concrete improvement of the model-independent super-replication and sub-replication strategies for barrier options proposed in [H. Brown, D. Hobson & L. C. G. Rogers (2001) Robust hedging of barrier options, Mathematical Finance 11 (3), 285–314.], which exploits the given beliefs on the implied skew. Our theoretical results are tested empirically, using the historical prices of S&P 500 options.
Dynamic Optimization of Functionally Graded Thin-Walled Box Beams
Authors: Maalawi Karam Y.
Published: February 2017

This paper introduces a mathematical model for optimizing the dynamic performance of thin-walled functionally graded box beams with closed cross-sections. The objective function is to maximize the natural frequencies and place them at their target values to avoid the occurrence of large amplitudes of vibration. The variables considered include fiber volume fraction, fiber orientation angle and ply thickness distributions. Various power-law expressions describing the distribution of the fiber volume fraction have been implemented, where the power exponent was taken as the main optimization variable. The mass of the beam is kept equal to that of a known reference beam. Side constraints are also imposed on the design variables in order to avoid having unacceptable optimal solutions. The mathematical formulation is carried out in dimensionless quantities, enabling the generalization to include models with different cross-sectional types and beam configurations. The optimization problem is solved by invoking the MatLab optimization ToolBox routines, along with structural dynamic analysis and eigenvalue calculation routines. A case study on the optimization of a cantilevered, single-cell spar beam made of carbon/epoxy composite is considered. The results for the basic case of uncoupled bending motion are given. Conspicuous design charts are developed, showing the optimum design trends for the mathematical models implemented in the study. It is concluded that the natural frequencies, even though expressed in implicit functions, are well-behaved, monotonic and can be treated as explicit functions in the design variables. Finally, the developed models can be suitably used in the global optimization of typical composite, functionally graded, thin-walled beam structures.
Performance of Semi-Active Base Isolation Systems under External Explosion
Authors: Mohebbi M. , Dadkhah H. D.
Published: February 2017

Structures designed against earthquake loads based on using control systems may experience explosions during their lifetime. In this paper, the performance of a hybrid control system composed of a low-damping base isolation and a supplemental magneto-rheological (MR) damper under external explosion has been studied. Base isolation system has the ability of decreasing the maximum structural response under blast loadings by shifting the period of the structure. In addition, MR damper improves the base isolation system performance by controlling the base drift of the structure. Hence, in this paper, the capability of a hybrid base isolation system equipped with an MR damper at the base has been evaluated in reducing the maximum structural response and base drift under external blast loadings. To determine the voltage of the semi-active MR damper, the H2/Linear Quadratic Gaussian (LQG) and clipped-optimal control algorithms have been applied. For numerical simulations, a 10-storey shear frame subjected to blast loadings applied on different floors has been considered and the performance of the hybrid isolation system and MR damper has been studied. The results have proven the effectiveness of the hybrid control system in controlling the maximum response and base drift of the isolated structure against spherical external explosion. Furthermore, comparing the performance of the hybrid passive and semi-active base isolation systems indicates that the semi-active hybrid base isolation system is more effective in reducing the root-mean-square (RMS) value of the base drift. Similarly, it has been found that the semi-active hybrid base isolation system also performs better than the high-damping base isolation system.
Vibrational Analysis of Size-Dependent Rotating Micro-Rings
Authors: Karimzadeh A. , Ahmadian M. T. , Firoozbakhsh K. , Rahaeifard M.
Published: February 2017

The size-dependent dynamic behavior and flexural vibration of rotating micro-rings are investigated in this paper. Using the modified couple stress theory and Hamilton’s principle, the governing equations of motion of the rotating micro-ring are derived. The natural frequencies for both extensional and inextensional micro-rings are obtained in closed form along with the forward and backward traveling waves derived. The results indicate that the natural frequencies of the rotating micro-ring are clearly size dependent, but the size dependency decreases as the speed of rotation of the ring increases, while it decreases when the radius-to-thickness ratio of the ring increases. A comparison between the natural frequencies of the extensional and inextensional micro-rings is performed. Moreover, the effect of the radius-to-thickness ratio of the ring on the behavior of the micro-ring is investigated. Good agreement is found between the natural frequencies obtained and the experimental results reported in the literature.
Motion Detection Enhanced Control of an Upper Limb Exoskeleton Robot for Rehabilitation Training
Authors: Ye Wenjun , Li Zhijun , Yang Chenguang , Chen Fei , Su Chun-Yi
Published: February 2017

The paper studies the control design of an exoskeleton robot based on electromyography (EMG). An EMG-based motion detection method is proposed to trigger the rehabilitation assistance according to user intention. An adaptive control scheme that compensates for the exoskeleton's dynamics is employed, and it is able to provide assistance tailored to the human user, who is supposed to participate actively in the training process. The experiment results verify the effectiveness of the control method developed in this paper.
ENaC activity in the cortical collecting duct of HKα1 H+,K+-ATPase knockout mice is uncoupled from Na+ intake
Authors: Mironova Elena , Lynch I. Jeanette , Berman Jonathan M. , Gumz Michelle L , Stockand James D. , Wingo Charles S.
Published: February 2017

Modulation of the epithelial Na+ channel (ENaC) activity in the collecting duct (CD) is an important mechanism for normal Na+ homeostasis. ENaC activity is inversely related to dietary Na+ intake, in part due to inhibitory paracrine purinergic regulation. Evidence suggests that H+,K+-ATPase activity in the CD also influences Na+ excretion. We hypothesized that renal H+,K+-ATPases affect Na+ reabsorption by the CD by modulating ENaC activity. ENaC activity in HKα1 H+,K+-ATPase knockout (HKα1−/−) mice was uncoupled from Na+ intake. ENaC activity on a high-Na+ diet was greater in the HKα1−/− mice than in WT mice. Moreover, dietary Na+ content did not modulate ENaC activity in the HKα1−/− mice as it did in WT mice. Purinergic regulation of ENaC was abnormal in HKα1−/− mice. In contrast to WT mice, where urinary [ATP] was proportional to dietary Na+ intake, urinary [ATP] did not increase in response to a high-Na+ diet in the HKα1−/− mice and was significantly lower than in the WT mice. HKα1−/− mice fed a high-Na+ diet had greater Na+ retention than WT mice and had an impaired dipsogenic response. These results suggest an important role for the HKα1 subunit in the regulation of purinergic signaling in the CD. They are also consistent with HKα1-containing H+,K+-ATPases as important components for the proper regulation of Na+ balance and the dipsogenic response to a high-salt diet. Such observations suggest a previously unrecognized element in Na+ regulation in the CD.
Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex
Authors: Cirstea Carmen M. , Choi In-Young , Lee Phil , Peng Huiling , Kaufman Christina L. , Frey Scott H.
Published: February 2017

Deafferentation is accompanied by large-scale functional reorganization of maps in the primary sensory and motor areas of the hemisphere contralateral to injury. Animal models of deafferentation suggest a variety of cellular-level changes including depression of neuronal metabolism and even neuronal death. Whether similar neuronal changes contribute to patterns of reorganization within the contralateral sensorimotor cortex of chronic human amputees is uncertain. We used functional MRI-guided proton magnetic resonance spectroscopy to test the hypothesis that unilateral deafferentation is associated with lower levels of N-acetylaspartate (NAA, a putative marker of neuronal integrity) in the sensorimotor hand territory located contralateral to the missing hand in chronic amputees ( n = 19) compared with the analogous hand territory of age- and sex-matched healthy controls ( n = 28). We also tested whether former amputees [i.e., recipients of replanted ( n = 3) or transplanted ( n = 2) hands] exhibit NAA levels that are indistinguishable from controls, possible evidence for reversal of the effects of deafferentation. As predicted, relative to controls, current amputees exhibited lower levels of NAA that were negatively and significantly correlated with the time after amputation. Contrary to our prediction, NAA levels in both replanted and transplanted patients fell within the range of the current amputees. We suggest that lower levels of NAA in current amputees reflects altered neuronal integrity consequent to chronic deafferentation. Thus local changes in NAA levels may provide a means of assessing neuroplastic changes in deafferented cortex. Results from former amputees suggest that these changes may not be readily reversible through reafferentation.

NEW & NOTEWORTHY This study is the first to use functional magnetic resonance-guided magnetic resonance spectroscopy to examine neurochemical mechanisms underlying functional reorganization in the primary somatosensory and motor cortices consequent to upper extremity amputation and its potential reversal through hand replantation or transplantation. We provide evidence for selective alteration of cortical neuronal integrity associated with amputation-related deafferentation that may not be reversible.
Impaired auditory-to-motor entrainment in Parkinson’s disease
Authors: te Woerd Erik S. , Oostenveld Robert , de Lange Floris P. , Praamstra Peter
Published: February 2017

Several electrophysiological studies suggest that Parkinson's disease (PD) patients have a reduced tendency to entrain to regular environmental patterns. Here we investigate whether this reduced entrainment concerns a generalized deficit or is confined to movement-related activity, leaving sensory entrainment intact. Magnetoencephalography was recorded during a rhythmic auditory target detection task in 14 PD patients and 14 control subjects. Participants were instructed to press a button when hearing a target tone amid an isochronous sequence of standard tones. The variable pitch of standard tones indicated the probability of the next tone to be a target. In addition, targets were occasionally omitted to evaluate entrainment uncontaminated by stimulus effects. Response times were not significantly different between groups and both groups benefited equally from the predictive value of standard tones. Analyses of oscillatory beta power over auditory cortices showed equal entrainment to the tones in both groups. By contrast, oscillatory beta power and event-related fields demonstrated a reduced engagement of motor cortical areas in PD patients, expressed in the modulation depth of beta power, in the response to omitted stimuli, and in an absent motor area P300 effect. Together, these results show equally strong entrainment of neural activity over sensory areas in controls and patients, but, in patients, a deficient translation of the adjustment to the task rhythm to motor circuits. We suggest that the reduced activation reflects not merely altered resonance to rhythmic external events, but a compromised recruitment of an endogenous response reflecting internal rhythm generation.

NEW & NOTEWORTHY Previous studies suggest that motor cortical activity in PD patients has a reduced tendency to entrain to regular environmental patterns. This study demonstrates that the deficient entrainment in PD concerns the motor system only, by showing equally strong entrainment of neural activity over sensory areas in controls and patients but, in patients, a deficient translation of this adjustment to the task rhythm to motor circuits.
Aggression from Patients or Next of Kin and Exposure to Bullying Behaviors: A Conglomerate Experience?
Authors: Reknes Iselin , Notelaers Guy , Magerøy Nils , Pallesen Ståle , Bjorvatn Bjørn , Moen Bente Elisabeth , Einarsen Ståle
Published: February 2017

Although workplace violence and aggression have been identified as important stressors in the nursing profession, studies simultaneously comparing patient-initiated aggression and exposure to bullying behaviors at work are rather scarce. The aim of this study was to compare aggression from patients or next of kin and exposure to bullying behaviors in terms of prevalence, health-related quality of life outcomes, and potential overlap in those targeted. In the period of 2008-2009, data were collected among 2059 members of the Norwegian Nurses Organization. Latent class (LC) analysis and a multivariate analysis of variance (MANOVA) were used to investigate the proposed relationships. The results showed that aggression from patients or next of kin and exposure to bullying behaviors were perceived as separate and independent stressors. Although aggression from patients or next of kin was more frequent than workplace bullying, the latter was the only significant stressor related to health-related quality of life in terms of reduced mental health functioning. Although being a rather infrequent experience, exposure to bullying behaviors seems to have more severe health-related outcomes for nurses than aggression from patients or next of kin. Hence, the results of the study strengthen previous findings and suggest that managers must aim to maintain a positive psychosocial work environment with zero-tolerance for bullying.
A Unified Constitutive Model for Creep and Cyclic Viscoplasticity Behavior Simulation of Steels Based on the Absolute Reaction Rate Theory
Authors: Chen Huayan , Zeng Xiangguo , Guo Yang , Wang Fang
Published: February 2017

In this work, the viscoplasticity and creep behavior for modified 9Cr-1Mo and 316 stainless steels were investigated. Based on the absolute reaction rate theory, a unified constitutive model incorporating internal state variables was proposed to characterize the evolution of the back stress. Also, the model was implemented by the ABAQUS system with the semi-implicit stress integration. Compared to the experimental data, the results demonstrated that the proposed approach could effectively simulate the cyclic softening and hardening behavior for such structural steels.
The Cognitive Neuroplasticity of Reading Recovery following Chronic Stroke: A Representational Similarity Analysis Approach
Authors: Fischer-Baum Simon , Jang Ava , Kajander David
Published: February 2017

Damage to certain left hemisphere regions leads to reading impairments, at least acutely, though some individuals eventually recover reading. Previous neuroimaging studies have shown a relationship between reading recovery and increases in contralesional and perilesional activation during word reading tasks, relative to controls. Questions remain about how to interpret these changes in activation. Do these changes reflect functional take-over, a reorganization of functions in the damaged brain? Or do they reveal compensatory masquerade or the use of alternative neural pathways to reading that are available in both patients and controls? We address these questions by studying a single individual, CH, who has made a partial recovery of reading familiar words following stroke. We use an fMRI analysis technique, representational similarity analysis (RSA), which allows us to decode cognitive function from distributed patterns of neural activity. Relative to controls, we find that CH shows a shift from visual to orthographic processing in contralesional regions, with a marginally significant result in perilesional regions as well. This pattern supports a contralesional reorganization of orthographic processing following stroke. More generally, these analyses demonstrate how powerful RSA can be for mapping the neural plasticity of language function.