bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic strain and support in couple: The mediating role of positive emotions
Authors: Rusu Petruta P. , Hilpert Peter , Falconier Mariana , Bodenmann Guy
Published: December 2017

This study examined positive emotions as mediating mechanisms in the association between economic strain and spouses' supportive behaviour. Data were collected from 295 married couples living in Romania. Results from the Actor–Partner Mediator Model indicated that economic strain had a negative indirect effect on spouses' supportive dyadic coping due to its negative association with partners' positive emotions (joy, contentment, and pride). For both partners, positive emotions decreased when they experienced economic strain, which in turn reduced supportive dyadic coping in couples. These findings have theoretical implications in explaining the association of economic strain with partners' positive emotions and behaviours and also clinical implications for practitioners working with couples experiencing economic strain.
Attacking your partners: Strategic alliances and competition between partners in product markets
Authors: Cui Victor , Yang Haibin , Vertinsky Ilan
Published: December 2017

Research Summary: This study contributes to the literature on strategic alliances by examining the impact of collaboration on competition between partners in product markets. We integrate the alliance learning and social network perspectives to examine how different combinations of exploratory and exploitative alliances between a firm and its partner influence the firm’s competition against its partner in product markets. Using a longitudinal dataset collected in the U.S. pharmaceutical industry (1984–2003), we find an inverted U‐shaped relationship between relative exploration (i.e., the proportion of exploratory alliances in the collaborative portfolio between a firm and its partner) and the firm’s competition against its partner. This relationship is negatively moderated by firms’ relational and structural embeddedness, but positively moderated by their positional embeddedness.

Managerial Summary: This study examines how different combinations of exploratory and exploitative alliances between two firms affect their competition in the product market. Using a 20‐year dataset collected in the U.S. pharmaceutical industry, we find that the proportion of exploratory alliances (i.e., joint development of critical innovations) in the alliance portfolio between a firm and its partner increases the firm’s competition against its partner, up to a tipping point at which such competition starts to decline. Given a certain combination of the two types of alliances, such competition is stronger if the firm has more alternative allies than its partner but weaker if the firm and its partner have previously collaborated or share common allies in their networks.
Threat of falling high status and corporate bribery: Evidence from the revealed accounting records of two South Korean presidents
Authors: Jeong Yujin , Siegel Jordan I.
Published: December 2017

Research Summary: Social status and its dynamics may be an important predictor of which firms will engage in large‐scale bribery. Prior theory is incomplete, however, and prior studies have lacked comprehensive and reliable data on firm‐level bribery decisions. We offer a new theoretical prediction and a novel data set on high‐level corruption in South Korea, where the accounting records of two presidents in the 1987–1992 era were exposed to after‐the‐fact legal and public scrutiny. We find that, controlling for a range of alternative explanations, the threat of falling high status—that is, the combination of longstanding high social status with current‐period mediocre economic performance relative to that of industry peers—is a statistically and economically meaningful predictor of increases in the amount of large‐scale corporate bribery.

Managerial Summary: What leads companies to engage in large‐scale bribery of senior politicians? Our concept of “threat of falling high status” refers to a circumstance where companies that have historically enjoyed high status through their owner families’ elite marriage networks experience mediocre economic performance relative to their peers. We show that this threat of falling high status is a notable determinant of large‐scale corporate bribery of senior politicians, using court data on corporate bribery of two South Korean presidents during 1987–1992. The implication of our study is twofold. Companies can strengthen internal control systems to avoid any large‐scale illegal activities at a higher level. Law enforcement agencies can also implement targeted monitoring programs to preempt illegal activities among companies facing the threat of falling high status.
Revisiting the imitation assumption: Why imitation may increase, rather than decrease, performance heterogeneity
Authors: Posen Hart E. , Martignoni Dirk
Published: December 2017

Research Summary: Imitation is a central construct in strategy theory because it is assumed to diminish inter‐firm performance heterogeneity within an industry. We revisit this assumption, which is premised on the logic that imitated practices act directly to make the imitator more similar to its target. This logic is incomplete because imitation also acts indirectly—via its effect on an imitator's post‐imitation experiential learning efforts through which it refines imitated practices and fills remaining knowledge gaps. We examine how an imitator's focus of attention during this post‐imitation experiential learning process impacts performance heterogeneity. Employing a computational model, we contrast the heterogeneity resulting from imitative entry with that from de novo (non‐imitative) entry and identify conditions under which imitation may increase, rather than decrease, inter‐firm performance heterogeneity.

Managerial Summary: Imitation is commonly assumed to be a low‐risk strategy by which firms can narrow the performance gap to the market leader. This assumption is predicated on an understanding of imitation that neglects the impact of imitation on subsequent, post‐imitation, learning. Such learning serves to refine the imitated practices and fill remaining knowledge gaps. Our theory suggests that imitation is more risky than is typically assumed. Imitation leads to bifurcated performance outcomes. An imitator is more likely to: (a) catch up to the market leader, and (b) perform far worse than it would have without imitation. Key factors driving the riskiness of imitation are the observability of the market leader's practices and an imitator's decision regarding its focus of attention in post‐imitation learning.
Do investors actually value sustainability? New evidence from investor reactions to the Dow Jones Sustainability Index (DJSI)
Authors: Hawn Olga , Chatterji Aaron K. , Mitchell Will
Published: December 2017

Research Summary: Research exploring investor reactions to sustainability has substantial empirical limitations, which we address with a large‐scale longitudinal financial event study of the first global sustainability index, DJSI World. We examine investor reactions to firms from 27 countries over 17 years that are added, deleted, or continue on the index. We find that once relevant controls and comparisons to observationally equivalent firms beyond the index are included, DJSI events have only limited significance and/or materiality. Nonetheless, investors' valuation of sustainability around the world has evolved over time, involving diminishing reactions to U.S. firms and increasing benefits, particularly of continuation on the index, over time. The study highlights the importance of careful analysis and longitudinal global samples in making inferences about the financial effects of social performance.

Managerial Summary: The debate about how investors perceive corporate social responsibility (CSR) predates Milton Friedman's famous statement that the only social responsibility of business is to increase profits. Although extensive research has studied whether sustainability contributes to financial performance, we have yet to understand whether investors believe it pays off. This financial event study of reactions to the addition, continuation, and deletion from DJSI World, the first global sustainability index, shows that investors care little about DJSI announcements. Nonetheless, there is some evidence that global assessments of sustainability are converging and that investors may increasingly be valuing continuation on the DJSI, suggesting that firms may gain at least limited benefits from reliable sustainability activities.
If I Leave Here Tomorrow: An Option View of Migration When Labor Market Quality Declines
Authors: Gardner John , Hendrickson Joshua R.
Published: December 2017

In this article, we provide a framework for determining when it is optimal to move when labor market opportunities are declining. We model the decision to migrate as akin to owning a financial option in which the exercise price is the fixed cost of moving. We show that a higher fixed cost associated with moving and a higher standard deviation of the quality of the labor market reduce the incentive to migrate. We then empirically examine whether the standard deviation of indicators of labor market quality reduce the likelihood of migration. Our findings strongly support this hypothesis, and imply that for the relatively mobile population of high‐skilled workers the counterfactual outmigration rates that would obtain if future labor‐market quality were known with certainty are more than twice observed rates.
Delta-Like 4 Activates Notch 3 to Regulate Self-Renewal in Skeletal Muscle Stem Cells
Authors: Low SiewHui , Barnes Josephine L. , Zammit Peter S. , Beauchamp Jonathan R.
Published: December 2017

Notch signaling is essential to maintain skeletal muscle stem cells in quiescence. However, the precise roles of different Notch receptors are incompletely defined. Here, we demonstrate a role for Notch3 (N3) in the self-renewal of muscle stem cells. We found that N3 is active in quiescent C2C12 reserve cells (RCs), and N3 over-expression and knockdown studies in C2C12 and primary satellite cells reveal a role in self-renewal. The Notch ligand Delta-like 4 (Dll4) is expressed by newly formed myotubes and interaction with this ligand is sufficient to maintain N3 activity in quiescent C2C12 RCs to prevent activation and progression into the cell cycle. Thus, our data suggest a model whereby during regeneration, expression of Dll4 by nascent muscle fibers triggers N3 signaling in associated muscle stem cells to recruit them to quiescence, thereby renewing the stem cell pool.
Experimental study of L‐shaped precast RC shear walls with middle cast‐in‐situ joint
Authors: Li Jianbao , Wang Lu , Lu Zheng , Wang Yan
Published: December 2017

Precast shear walls, as an environmentally friendly building system, have been vigorously developed in China. There are many vertical and horizontal joints on precast reinforced concrete shear wall system, which certainly have a significant effect on seismic performance of structures. In this paper, 3 L‐shaped precast reinforced concrete shear walls that were assembled by 2 precast parts through a middle cast‐in‐situ joint and a compared 1 completely cast‐in‐situ were tested under low frequency cyclic loading to investigate their seismic behaviors. The vertical distributed reinforcements in the three precast specimens were equivalently spliced by grouting sleeves arranged along the center line of the wall, and the horizontal reinforcements were directly anchored in cast‐in‐situ joints. The experimental results, including failure mode, yielding load and displacement, skeleton curve, energy dissipation, stiffness degradation, ductility, and so forth were presented in the paper. The results show that the precast specimens have similar bearing capacity whereas much better deformation capacity and ductility compared to the cast‐in‐situ specimen. Additionally, the experimental results of ultimate shear capacity of specimens were also compared with that of the calculation results. These results indicate that the tested precast shear walls have good and reliable seismic performance and can be used as a structural member in engineering projects.
Optimizing parameters of tuned mass damper subjected to critical earthquake
Authors: Kamgar Reza , Samea Parham , Khatibinia Mohsen
Published: December 2017

Tuned mass damper (TMD) has been proposed as one of the vibration control methods for rehabilitation of buildings. Because the parameters of TMD can significantly affect the seismic performance of structures, many researches focused on finding the optimum parameters. Because earthquakes are random phenomena and future earthquakes in comparison with past earthquakes may be more destructive, the optimum design of TMD subjected to selected earthquakes can be nonconservative. Hence, the main contribution of this paper is to present the optimal design of TMD for the seismic vibration control of a structure subjected to a critical earthquake that produces the most severe response of a structure. In order to achieve this purpose, the parameters of TMD are optimized through minimizing the maximum displacement of the roof. First, three optimization methods are used to obtain the optimal parameters of TMD for a 10‐story shear building subjected to the critical earthquakes. Finally, the responses of the controlled and uncontrolled buildings such as the roof displacement, strokes, transfer function, and different forms of energy are compared. Results show that the optimum designs of TMD not only effectively reduce the roof displacement but also improve the seismic performance of the building.
Formally sound implementations of security protocols with JavaSPI
Authors: Sisto Riccardo , Bettassa Copet Piergiuseppe , Avalle Matteo , Pironti Alfredo
Published: December 2017

Designing and coding security protocols is an error prone task. Several flaws are found in protocol implementations and specifications every year. Formal methods can alleviate this problem by backing implementations with rigorous proofs about their behavior. However, formally-based development typically requires domain specific knowledge available only to few experts and the development of abstract formal models that are far from real implementations. This paper presents a Java-based protocol design and implementation framework, where the user can write a security protocol symbolic model in Java, using a well defined subset of the language that corresponds to applied
π
-calculus. This Java model can be symbolically executed in the Java debugger, formally verified with ProVerif, and further refined to an interoperable Java implementation of the protocol. Soundness theorems are provided to prove that, under some reasonable assumptions, a simulation relation relates the Java refined implementation to the symbolic model verified by ProVerif, so that, for the usual security properties, a property verified by ProVerif on the symbolic model is preserved in the Java refined implementation. The applicability of the framework is evaluated by developing an extensive case study on the popular SSL protocol.
Reduced methanol input induces increased protein output byAOX1promoter in atrans-acting elements engineeredPichia pastoris
Authors: Wang Jinjia , Wang Xiaolong , Shi Lei , Zhang Yuanxing , Zhou Xiangshan , Cai Menghao
Published: December 2017

High oxygen consumption and heat release caused by methanol catabolism usually bring difficulties to industrial scale-up and cost for protein expression driven by methanol-induced AOX1 promoter in Pichia pastoris. Here, reduced methanol feeding levels were investigated for expression of insulin precursor in a trans-acting elements engineered P. pastoris strain MF1-IP. Insulin precursor expression level reached 6.69 g/(L supernatant) at the methanol feeding rate of 6.67 mL/(h·L broth), which was 59% higher than that in the wild-type strain WT-IP at the methanol feeding rate of 12 mL/(h·L broth). Correspondingly, the insulin precursor expression level in fermentation broth and maximum specific insulin precursor production rate was 137 and 77% higher than the WT-IP, respectively. However, oxygen consumption and heat evolution were reduced, and the highest oxygen consumption rate and heat evolution rate of the MF1-IP were 18.0 and 37.7% lower than the WT-IP, respectively.
Clinical Cardiovascular Genetic Counselors Take a Leading Role in Team‐based Variant Classification
Authors: Reuter Chloe , Grove Megan E. , Orland Kate , Spoonamore Katherine , Caleshu Colleen
Published: December 2017

We sought to delineate the genetic test review and interpretation practices of clinical cardiovascular genetic counselors. A one‐time anonymous online survey was taken by 46 clinical cardiovascular genetic counselors recruited through the National Society of Genetic Counselors Cardiovascular Special Interest Group. Nearly all (95.7%) gather additional information on variants reported on clinical genetic test reports and most (81.4%) assess the classification of such variants. Clinical cardiovascular genetic counselors typically (81.0%) classify variants in collaboration with cardiologist and/or geneticist colleagues, with the genetic counselor as the team member who is primarily responsible. Variant classification is a relatively recent (mean 3.2 years) addition to practice. Most genetic counselors learned classification skills on the job from clinical and laboratory colleagues. Recent graduates were more likely to have learned this in graduate school (p < 0.001). Genetic counselors are motivated to take responsibility for the classification of variants because of prior experiences with variant reclassification, inconsistencies between laboratories, and incomplete laboratory reports. They are also driven by a sense of professional duty and their proximity to the clinical context. This practice represents a broadening of the skill set of clinical cardiovascular genetic counselors and a unique expertise that they contribute to the interdisciplinary teams in which they work.
Mechanical stress increases brain amyloid β, tau, and α‐synuclein concentrations in wild‐type mice
Authors: Levy Nogueira Marcel , Hamraz Minoo , Abolhassani Mohammad , Bigan Erwan , Lafitte Olivier , Steyaert Jean‐Marc , Dubois Bruno , Schwartz Laurent
Published: December 2017

Introduction

Exposure to traumatic brain injury is a core risk factor that predisposes an individual to sporadic neurodegenerative diseases. We provide evidence that mechanical stress increases brain levels of hallmark proteins associated with neurodegeneration.

Methods

Wild‐type mice were exposed to multiple regimens of repetitive mild traumatic brain injury, generating a range of combinations of impact energies, frequencies, and durations of exposure. Brain concentrations of amyloid β 1–42 (Aβ1–42), total tau, and α‐synuclein were measured by sandwich enzyme‐linked immunosorbent assay.

Results

There was a highly significant main effect of impact energy, frequency, and duration of exposure on Aβ1–42, tau, and α‐synuclein levels (P < .001), and a significant interaction between impact energy and duration of exposure for Aβ1–42 and tau (P < .001), but not for α‐synuclein.

Discussion

Dose‐dependent and cumulative influence of repetitive mild traumatic brain injury–induced mechanical stress may trigger and/or accelerate neurodegeneration by pushing protein concentration over the disease threshold.
kW-level, narrow-linewidth linearly polarized fiber laser with excellent beam quality through compact one-stage amplification scheme
Authors: Jiang Man , Ma Pengfei , Huang Long , Xu Jiangming , Zhou Pu , Gu Xijia
Published: December 2017

In this manuscript, we demonstrate high-power, narrow-linewidth linearly polarized fiber laser with excellent beam quality through compact one-stage amplification scheme. By employing a single-mode–multimode–single-mode structure seed laser, a linearly polarized Yb-doped fiber laser with narrow linewidth and high output power is achieved. This laser, when used as a master oscillator, can be capable of suppressing the ASE in the process of power amplification. Thus, only one-stage amplification structure is used to scale up the laser power, and linearly polarized output with a polarization extinction ration of 14 dB, a narrow linewidth of 0.3 nm and an output power of 1018 W are achieved. Moreover, due to the good beam quality of seed laser and the well-designed amplifier stage, the beam quality of the output laser is near-diffraction-limited with $M_{x}^{2}\sim 1.18$ and $M_{y}^{2}\sim 1.24$ at the maximum power, and without mode instability occurring.
Dynamics of viscous backflow from a model fracture network
Authors: Dana Asaf , Zheng Zhong , Peng Gunnar G. , Stone Howard A. , Huppert Herbert E. , Ramon Guy Z.
Published: December 2017

Hydraulic fracturing for production of oil and gas from shale formations releases fluid waste, by-products that must be managed carefully to avoid significant harm to human health and the environment. These fluids are presumed to result from a variety of fracture relaxation processes, and are commonly referred to as ‘flowback’ and ‘produced water’, depending primarily on the time scale of their appearance. Here, a model is presented for investigating the dynamics of backflows caused by the elastic relaxation of a pre-strained medium, namely a single fracture and two model fracture network systems: a single bifurcated channel and its generalization for $n$ bifurcated fracture generations. Early- and late-time asymptotic solutions are obtained for the model problems and agree well with numerical solutions. In the late-time period, the fracture apertures and backflow rates exhibit a time dependence of $t^{-1/3}$ and $t^{-4/3}$, respectively. In addition, the pressure distributions collapse to universal curves when scaled by the maximum pressure in the system, which we calculate as a function of $n$. The pressure gradient along the network is steepest near the outlet while the bulk of the network serves as a ‘reservoir’. Fracture networks with larger $n$ are less efficient at evicting fluids, manifested through a longer time required for a given fractional reduction of the initial volume. The developed framework may be useful for informing engineering design and environmental regulations.
Transient effects in the translation of bubbles insonated with acoustic pulses of finite duration
Authors: Igualada-Villodre Elena , Medina-Palomo Ana , Vega-Martínez Patricia , Rodríguez-Rodríguez Javier
Published: December 2017

The translation of a bubble under the action of an acoustic forcing finds applications in fields ranging from drug delivery to sonoluminescence. This phenomenon has been widely studied for cases where the amplitude of the forcing remains constant over time. However, in many practical applications, the duration of the forcing is not long enough for the bubble to attain a constant translational velocity, mainly due to the effect of the history force. Here, we develop a formulation, valid in the limit of very viscous flow and small-amplitude acoustic forcing, that allows us to describe the transient dynamics of bubbles driven by acoustic pulses consisting of finite numbers of cycles. We also present an asymptotic solution to this theory for the case of a finite-duration sinusoidal pressure pulse. This solution takes into account both the history integral term and the transient period that the bubble needs to achieve steady radial oscillations, the former being dominant during most of the acceleration process. Moreover, by introducing some additional assumptions, we derive a simplified formula that describes the time evolution of the bubble velocity fairly well. Using this solution, we show that the convergence to the steady translational velocity, given by the so-called Bjerknes force, occurs rather slowly, namely as $\unicode[STIX]{x1D70F}^{-1/2}$, where $\unicode[STIX]{x1D70F}$ is the time made dimensionless with the viscous time scale of the bubble, which explains the slow convergence of the bubble velocity and stresses the importance of taking the history force into account.
Higher-order moment theories for dilute granular gases of smooth hard spheres
Authors: Gupta Vinay Kumar , Shukla Priyanka , Torrilhon Manuel
Published: December 2017

Grad’s method of moments is employed to develop higher-order Grad moment equations – up to the first 26 moments – for dilute granular gases within the framework of the (inelastic) Boltzmann equation. The homogeneous cooling state of a freely cooling granular gas is investigated with the Grad 26-moment equations in a semi-linearized setting and it is shown that the granular temperature in the homogeneous cooling state still decays according to Haff’s law while the other higher-order moments decay on a faster time scale. The nonlinear terms of the fully contracted fourth moment are also considered and, by exploiting the stability analysis of fixed points, it is shown that these nonlinear terms have a negligible effect on Haff’s law. Furthermore, an even larger Grad moment system, which includes the fully contracted sixth moment, is also scrutinized and the stability analysis of fixed points is again exploited to conclude that even the inclusion of the scalar sixth-order moment into the Grad moment system has a negligible effect on Haff’s law. The constitutive relations for the stress and heat flux (i.e. the Navier–Stokes and Fourier relations) are derived through the Grad 26-moment equations and compared with those obtained via the Chapman–Enskog expansion and via computer simulations. The linear stability of the homogeneous cooling state is analysed through the Grad 26-moment system and various subsystems by decomposing them into longitudinal and transverse systems. It is found that one eigenmode in both longitudinal and transverse systems in the case of inelastic gases is unstable. By comparing the eigenmodes from various theories, it is established that the 13-moment eigenmode theory predicts that the unstable heat mode of the longitudinal system remains unstable for all wavenumbers below a certain coefficient of restitution, while any other higher-order moment theory shows that this mode becomes stable above some critical wavenumber for all values of the coefficient of restitution. In particular, the Grad 26-moment theory leads to a smooth profile for the critical wavenumber, in contrast to the other considered theories. Furthermore, the critical system size obtained through the Grad 26-moment theory is in excellent agreement with that obtained through existing theories.
On the viscous flows of leak-out and spherical cap natation
Authors: Ryham Rolf J.
Published: December 2017

This paper deals with the hydrodynamics of a viscous liquid passing through the hole in a deflating hollow sphere. I employ the method of complementary integrals and calculate in closed form the pressure and streamfunction for the axisymmetric, creeping motion coming from changes in radius. The resulting flow fields describe the motion of a deformable spherical cap in a viscous environment, where the deformations include changes in the size of the spherical cap, the size of the hole and translation of the body along the axis of symmetry. The calculations yield explicit expressions for the jumps in pressure and resistance coefficients for the combined deformations. The equation for the translation force shows that a freely suspended spherical cap is able to propel as an active swimmer. The expression for pressure contains the classic Sampson flow rate equation as a limiting case, but simulations show that the pressure must also account for the velocity of hole widening to correctly predict outflow rates in physiology. Movies based on the closed-form solutions visualize the flow fields and pressures as part of physical processes.
Advective balance in pipe-formed vortex rings
Authors: Shariff Karim , Krueger Paul S.
Published: December 2017

Vorticity distributions in axisymmetric vortex rings produced by a piston–pipe apparatus are numerically studied over a range of Reynolds numbers, $Re$, and stroke-to-diameter ratios, $L/D$. It is found that a state of advective balance, such that $\unicode[STIX]{x1D701}\equiv \unicode[STIX]{x1D714}_{\unicode[STIX]{x1D719}}/r\approx F(\unicode[STIX]{x1D713},t)$, is achieved within the region (called the vortex ring bubble) enclosed by the dividing streamline. Here $\unicode[STIX]{x1D701}\equiv \unicode[STIX]{x1D714}_{\unicode[STIX]{x1D719}}/r$ is the ratio of azimuthal vorticity to cylindrical radius, and $\unicode[STIX]{x1D713}$ is the Stokes streamfunction in the frame of the ring. Some, but not all, of the $Re$ dependence in the time evolution of $F(\unicode[STIX]{x1D713},t)$ can be captured by introducing a scaled time $\unicode[STIX]{x1D70F}=\unicode[STIX]{x1D708}t$, where $\unicode[STIX]{x1D708}$ is the kinematic viscosity. When $\unicode[STIX]{x1D708}t/D^{2}\gtrsim 0.02$, the shape of $F(\unicode[STIX]{x1D713})$ is dominated by the linear-in-$\unicode[STIX]{x1D713}$ component, the coefficient of the quadratic term being an order of magnitude smaller. An important feature is that, as the dividing streamline ($\unicode[STIX]{x1D713}=0$) is approached, $F(\unicode[STIX]{x1D713})$ tends to a non-zero intercept which exhibits an extra $Re$ dependence. This and other features are explained by a simple toy model consisting of the one-dimensional cylindrical diffusion equation. The key ingredient in the model responsible for the extra $Re$ dependence is a Robin-type boundary condition, similar to Newton’s law of cooling, that accounts for the edge layer at the dividing streamline.
Motion of open vortex-current filaments under the Biot–Savart model
Authors: Kennedy Daniel T. , Van Gorder Robert A.
Published: December 2017

Vortex-current filaments have been used to study phenomena such as coronal loops and solar flares as well as tokamaks, and recent experimental work has demonstrated dynamics akin to vortex-current filaments on a table-top plasma focus device. While MHD vortex dynamics and related applications to turbulence have attracted consideration in the literature due to a wide variety of applications, not much analytical progress has been made in this area, and the analysis of such vortex-current filament solutions under various geometries may motivate further experimental efforts. To this end, we consider the motion of open, isolated vortex-current filaments in the presence of magnetohydrodynamic (MHD) as well as the standard hydrodynamic effects. We begin with the vortex-current model of Yatsuyanagi, Hatori & Kato (J. Phys. Soc. Japan, vol. 65, 1996, pp. 745–759) giving the self-induced motion of a vortex-current filament. We give the ‘cutoff’ formulation of the Biot–Savart integrals used in this model, to avoid the singularity at the vortex core. We then study the motion of a variety of vortex-current filaments, including helical, planar and self-similar filament structures. In the case where MHD effects are weak relative to hydrodynamic effects, the filaments behave as expected from the pure hydrodynamic theory. However, when MHD effects are strong enough to dominate, then we observe structural changes to the filaments in all cases considered. The most common finding is reversal of vortex-current filament orientation for strong enough MHD effects. Kelvin waves along a vortex filament (as seen for helical and self-similar structures) will reverse their translational and rotational motion under strong MHD effects. Our findings support the view that vortex-current filaments can be studied in a manner similar to classical hydrodynamic vortex filaments, with the primary role of MHD effects being to change the filament motion, while preserving the overall geometric structure of such filaments.
Spatial–spectral characteristics of momentum transport in a turbulent boundary layer
Authors: Fiscaletti D. , de Kat R. , Ganapathisubramani B.
Published: December 2017

Spectral content and spatial organization of momentum transport events are investigated in a turbulent boundary layer at the Reynolds number $(Re_{\unicode[STIX]{x1D70F}})=2700$, with time-resolved planar particle image velocimetry. The spectral content of the Reynolds-shear-stress fluctuations reveals that the largest range of time and length scales can be observed in proximity to the wall, while this range becomes progressively more narrow when the wall distance increases. Farther from the wall, longer time and larger length scales exhibit an increasing spectral content. Wave velocities of transport events are estimated from wavenumber–frequency power spectra at different wall-normal locations. Wave velocities associated with ejection events (Q2) are lower than the local average streamwise velocity, while sweep events (Q4) are characterized by wave velocities larger than the local average velocity. These velocity deficits are almost insensitive to the wall distance, which is also confirmed from time tracking the intense transport events. The vertical advection velocities of the intense ejection and sweep events are on average a small fraction of the friction velocity $U_{\unicode[STIX]{x1D70F}}$, different from previous observations in a channel flow. In the range of wall-normal locations $60<y^{+}<600$, sweeps are considerably larger than ejections, which could be because the ejections are preferentially located in between the legs of hairpin packets. Finally, it is observed that negative quadrant events of the same type tend to appear in groups over a large spatial streamwise extent.
THE ELUSIVE RIGHT TO TRUTH IN TRANSITIONAL HUMAN RIGHTS JURISPRUDENCE
Authors: Sweeney James A
Published: December 2017

This article undertakes a comparative legal analysis of the scope of an emerging legal duty to find the truth about historical human rights abuses after periods of political transition. There is substantial inconsistency between human rights regimes on how they establish temporal jurisdiction in their transitional jurisprudence, which has not yet been systematically investigated. This contribution fills the gap in the literature by identifying and critiquing the way in which the right to truth in times of transition is both expressly and implicitly vindicated in the decisions of the Human Rights Committee, and the regional jurisprudence of the Inter-American Court of Human Rights and European Court of Human Rights (the conclusion also addresses the less voluminous African regional jurisprudence). It is argued that the ‘underlying values’ of human rights treaties can provide a foundation for a powerful but finite right to truth.
Deleveraging Risk
Authors: Richardson Scott , Saffi Pedro A. C. , Sigurdsson Kari
Published: December 2017

Deleveraging risk is the risk attributable to investing in a security held by levered investors. When there is an aggregate negative shock to the availability of funding capital, securities with a greater presence of levered investors experience extreme return realizations as these investors unwind their positions. Using data on equity loans as a proxy for the degree of levered positions in a given stock, we find robust evidence of deleveraging risk. Stocks with a high degree of short selling experience large positive returns and a decrease in short selling around periods of funding capital scarcity.
Understanding host–parasite relationship: the immune central nervous system microenvironment and its effect on brain infections
Authors: Adalid-Peralta Laura , Sáenz Brenda , Fragoso Gladis , Cárdenas Graciela
Published: December 2017

The central nervous system (CNS) has been recognized as an immunologically specialized microenvironment, where immune surveillance takes a distinctive character, and where delicate neuronal networks are sustained by anti-inflammatory factors that maintain local homeostasis. However, when a foreign agent such as a parasite establishes in the CNS, a set of immune defences is mounted and several immune molecules are released to promote an array of responses, which ultimately would control the infection and associated damage. Instead, a host–parasite relationship is established, in the context of which a close biochemical coevolution and communication at all organization levels between two complex organisms have developed. The ability of the parasite to establish in its host is associated with several evasion mechanisms to the immune response and its capacity for exploiting host-derived molecules. In this context, the CNS is deeply involved in modulating immune functions, either protective or pathogenic, and possibly in parasitic activity as well,viainteractions with evolutionarily conserved molecules such as growth factors, neuropeptides and hormones. This review presents available evidence on some examples of CNS parasitic infections inducing different morbi-mortality grades in low- or middle-income countries, to illustrate how the CNS microenvironment affect pathogen establishment, growth, survival and reproduction in immunocompetent hosts. A better understanding of the influence of the CNS microenvironment on neuroinfections may provide relevant insights into the mechanisms underlying these pathologies.
Going covert: Inner and private speech in language learning
Authors: de Guerrero María C. M.
Published: December 2017

Roughly 30 years ago researchers in the second language acquisition (SLA) field started to take a focused interest in the study of inner speech (IS) and private speech (PS) processes in second language (L2) learning and use. The purpose of this review is to assess the status of current research and the progress made during the last ten years on the development and experience of covertly using a language other than the first. The review begins with a critical discussion of the challenges involved in defining and conceptualizing IS and PS. To conduct the search of relevant sources, a broad understanding of IS as ‘silent speech for oneself’ and PS as ‘externalized speech for oneself’ was adopted. After a brief synopsis of past research on L2 IS and PS, recent (2005–2015) work is discussed both from a generic-language stance and an L2, bilingual, and multilingual perspective. The review then takes a critical look at the difficult methodological issue of data collection on IS and PS, highlighting strengths and limitations in recent research. Pedagogical implications derived from the research reviewed and suggestions for future studies are discussed.
Keeping it practical and keeping it simple
Authors: Nation Paul
Published: December 2017

When I look back over my career as a teacher-trainer and researcher, I can see two themes that run through my work. The first theme is my concern for the practical issues of teaching English as a foreign language (EFL), with the strong proviso that practice must be based as far as possible in research. For me this represents the applied in applied linguistics. The second theme is a concern for seeing what the parts are that make up the whole. I think underlying this concern is the desire to see the principles governing the way the parts go together, and underlying this is a tendency to want to see what is simple and rule-based. Knowledge needs to be communicated to others and this is best done if we are aware of the important basic principles and components, and can present them as simply as possible.
A systematic review of English medium instruction in higher education
Authors: Macaro Ernesto , Curle Samantha , Pun Jack , An Jiangshan , Dearden Julie
Published: December 2017

After outlining why a systematic review of research in English medium instruction (EMI) in higher education (HE) is urgently required, we briefly situate the rapidly growing EMI phenomenon in the broader field of research in which content and language have been considered and compare HE research outputs with those from other phases of education. An in-depth review of 83 studies in HE documents the growth of EMI in different geographical areas. We describe studies which have investigated university teachers’ beliefs and those of students before attempting to synthesise the evidence on whether teaching academic subjects through the medium of English as a second language (L2) is of benefit to developing English proficiency without a detrimental effect on content learning. We conclude that key stakeholders have serious concerns regarding the introduction and implementation of EMI despite sometimes recognising its inevitability. We also conclude that the research evidence to date is insufficient to assert that EMI benefits language learning nor that it is clearly detrimental to content learning. There are also insufficient studies demonstrating, through the classroom discourse, the kind of practice which may lead to beneficial outcomes. This insufficiency, we argue, is partly due to research methodology problems both at the micro and macro level.
Risk factors for acquisition of multidrug-resistant Escherichia coli and development of community-acquired urinary tract infections
Authors: UKAH U. V. , GLASS M. , AVERY B. , DAIGNAULT D. , MULVEY M. R. , REID-SMITH R. J. , PARMLEY E. J. , PORTT A. , BOERLIN P. , MANGES A. R.
Published: December 2017

We examined risk factors associated with the intestinal acquisition of antimicrobial-resistant extraintestinal pathogenic Escherichia coli (ExPEC) and development of community-acquired urinary tract infection (UTI) in a case-control study of young women across Canada. A total of 399 women were recruited; 164 women had a UTI caused by E. coli resistant to ⩾1 antimicrobial classes and 98 had a UTI caused by E. coli resistant to ⩾3 antimicrobial classes. After adjustment for age, student health service (region of Canada) and either prior antibiotic use or UTI history, consumption of processed or ground chicken, cooked or raw shellfish, street foods and any organic fruit; as well as, contact with chickens, dogs and pet treats; and travel to Asia, were associated with an increased risk of UTI caused by antimicrobial resistant E. coli. A decreased risk of antimicrobial resistant UTI was associated with consumption of apples, nectarines, peppers, fresh herbs, peanuts and cooked beef. Drug-resistant UTI linked to foodborne and environmental exposures may be a significant public health concern and understanding the risk factors for intestinal acquisition of existing or newly emerging lineages of drug-resistant ExPEC is important for epidemiology, antimicrobial stewardship and prevention efforts.
Prenatal influences on temperament development: The role of environmental epigenetics
Authors: Gartstein Maria A. , Skinner Michael K.
Published: December 2017

This review summarizes current knowledge and outlines future directions relevant to questions concerning environmental epigenetics and the processes that contribute to temperament development. Links between prenatal adversity, epigenetic programming, and early manifestations of temperament are important in their own right, also informing our understanding of biological foundations for social–emotional development. In addition, infant temperament attributes represent key etiological factors in the onset of developmental psychopathology, and studies elucidating their prenatal foundations expand our understanding of developmental origins of health and disease. Prenatal adversity can take many forms, and this overview is focused on the environmental effects of stress, toxicants, substance use/psychotropic medication, and nutrition. Dysregulation associated with attention-deficit/hyperactivity–disruptive disorders was noted in the context of maternal substance use and toxicant exposures during gestation, as well as stress. Although these links can be made based on the existing literature, currently few studies directly connect environmental influences, epigenetic programming, and changes in brain development/behavior. The chain of events starting with environmental inputs and resulting in alterations to gene expression, physiology, and behavior of the organism is driven by epigenetics. Epigenetics provides the molecular mechanism of how environmental factors impact development and subsequent health and disease, including early brain and temperament development.
Adolescence effortful control as a mediator between family ecology and problematic substance use in early adulthood: A 16-year prospective study
Authors: Mun Chung Jung , Dishion Thomas J. , Tein Jenn-Yun , Otten Roy
Published: December 2017

This study examined the mediated effect of early adolescence familial context on early adulthood problematic substance use through effortful control in late adolescence. The sample consisted of a community sample of 311 adolescents and their families comprising the control group within a randomized trial intervention. Parental monitoring and parent–child relationship quality (P-C RQ) were measured annually from ages 11 to 13. Effortful control was measured by self-reports and parent and teacher reports at ages 16 to 17. Self-reports of problematic tobacco, alcohol, and marijuana use were measured at ages 18 to 19, 21 to 22, 23 to 24, and 26 to 27. Structural equation modeling was employed to test hypothesized models. Only P-C RQ was found to be significantly associated with adolescent effortful control. As expected, higher levels of adolescent effortful control were associated with lower problematic substance use through early adulthood, controlling for previous substance use levels. Mediation analyses showed that effortful control significantly mediated the relationship between P-C RQ and problematic substance use. Higher relationship quality between youth and parents in early adolescence is associated with higher effortful control, which in turn relates to a lower level of problematic substance use in early adulthood.
Tracking data of the Little Bustard Tetrax tetrax in Iberia shows high anthropogenic mortality
Authors: MARCELINO JOANA , MOREIRA FRANCISCO , MAÑOSA SANTI , CUSCÓ FRANCESC , MORALES MANUEL B. , GARCÍA DE LA MORENA ELADIO L. , BOTA GERARD , PALMEIRIM JORGE M. , SILVA JOÃO P.
Published: December 2017

The Little Bustard Tetrax tetrax (Linnaeus, 1758) is a medium-sized, ‘Near Threatened’ steppe bird, whose Iberian population has been alarmingly declining over recent decades. Although this population loss has been mainly attributed to agricultural intensification, there is no information on Little Bustard adult mortality levels and their drivers. Based on a joint effort combining all the tracking data on adult Little Bustards collected over a period of 12 years by all research teams working with the species in Iberia, we found that annual anthropogenic mortality is likely to have a critical impact on the species, with values almost as high as the mortality attributed to predation. Collision with power lines was found to be the main anthropogenic threat to the adult population (3.4–3.8%/year), followed by illegal killing (2.4–3%/year), which had a higher impact than initially foreseen. Our work shows how poorly understood and previously unknown threats are affecting the survival of the most important Little Bustard population in Europe.
THE STRONG MORITA EQUIVALENCE FOR INCLUSIONS OF -ALGEBRAS AND CONDITIONAL EXPECTATIONS FOR EQUIVALENCE BIMODULES
Authors: KODAKA KAZUNORI , TERUYA TAMOTSU
Published: December 2017

We shall introduce the notions of strong Morita equivalence for unital inclusions of unital$C^{\ast }$-algebras and conditional expectations from an equivalence bimodule onto its closed subspace with respect to conditional expectations from unital$C^{\ast }$-algebras onto their unital$C^{\ast }$-subalgebras. Also, we shall study their basic properties.