bluuebunny/crossref_metadata_2025 huggingface dataset:
Waiting for the Second Treat: Developing Culture‐Specific Modes of Self‐Regulation
Authors: Lamm Bettina , Keller Heidi , Teiser Johanna , Gudi Helene , Yovsi Relindis D. , Freitag Claudia , Poloczek Sonja , Fassbender Ina , Suhrke Janina , Teubert Manuel , Vöhringer Isabel , Knopf Monika , Schwarzer Gudrun , Lohaus Arnold
Published: June 2017

The development of self‐regulation has been studied primarily in Western middle‐class contexts and has, therefore, neglected what is known about culturally varying self‐concepts and socialization strategies. The research reported here compared the self‐regulatory competencies of German middle‐class (N = 125) and rural Cameroonian Nso preschoolers (N = 76) using the Marshmallow test (Mischel, 2014). Study 1 revealed that 4‐year‐old Nso children showed better delay‐of‐gratification performance than their German peers. Study 2 revealed that culture‐specific maternal socialization goals and interaction behaviors were related to delay‐of‐gratification performance. Nso mothers’ focus on hierarchical relational socialization goals and responsive control seems to support children's delay‐of‐gratification performance more than German middle‐class mothers’ emphasis on psychological autonomous socialization goals and sensitive, child‐centered parenting.
Transient sex differences during adolescence on auditory perceptual tasks
Authors: Huyck Julia Jones , Wright Beverly A.
Published: June 2017

Many perceptual abilities differ between the sexes. Because these sex differences have been documented almost exclusively in adults, they have been attributed to sex‐specific neural circuitry that emerges during development and is maintained in the mature perceptual system. To investigate whether behavioral sex differences in perception can also have other origins, we compared performance between males and females ranging in age from 8 to 30 years on auditory temporal‐interval discrimination and tone‐in‐noise detection tasks on which there are no sex differences in adults. If sex differences in perception arise only from the establishment and subsequent maintenance of sex‐specific neural circuitry, there should be no sex differences during development on these tasks. In contrast, sex differences emerged in adolescence but resolved by adulthood on two of the six conditions, with signs of a similar pattern on a third condition. In each case, males reached mature performance earlier than females, resulting in a sex difference in the interim. These results suggest that sex differences in perception may arise from differences in the maturational timing of common circuitry used by both sexes. They also imply that sex differences in perceptual abilities may be more prevalent than previously thought based on adult data alone.
Developing guinea pig brain as a model for cortical folding
Authors: Hatakeyama Jun , Sato Haruka , Shimamura Kenji
Published: June 2017

The cerebral cortex in mammals, the neocortex specifically, is highly diverse among species with respect to its size and morphology, likely reflecting the immense adaptiveness of this lineage. In particular, the pattern and number of convoluted ridges and fissures, called gyri and sulci, respectively, on the surface of the cortex are variable among species and even individuals. However, little is known about the mechanism of cortical folding, although there have been several hypotheses proposed. Recent studies on embryonic neurogenesis revealed the differences in cortical progenitors as a critical factor of the process of gyrification. Here, we investigated the gyrification processes using developing guinea pig brains that form a simple but fundamental pattern of gyri. In addition, we established an electroporation‐mediated gene transfer method for guinea pig embryos. We introduce the guinea pig brain as a useful model system to understand the mechanisms and basic principle of cortical folding.
Outcomes in Duchenne muscular dystrophy: nature, nurture, culture–or all three?
Authors: Langer Thorsten , Kirschner Janbernd
Published: June 2017

This commentary is on the original article by Hufton and Roper on pages 837–842 of this issue.
Increase in the incidence of severe hypoglycaemia in people with Type 2 diabetes in spite of new drugs: analysis based on health insurance data from Germany
Authors: Müller N. , Lehmann T. , Gerste B. , Adler J.‐B. , Kloos C. , Hartmann M. , Kramer G. , Kuniss N. , Müller U. A.
Published: June 2017

Aim

To evaluate the use of new anti‐hyperglycaemic agents that offer effective glycaemic control while reducing risk of hypoglycaemia, by analysing the incidence rates of severe hypoglycaemia in 2006 vs 2011 in relation to the medication.

Methods

This cross‐sectional, population‐based study used German health insurance data. All adults diagnosed with Type 2 diabetes mellitus (extrapolated to the German population: 6.35 million in 2006 and 7.52 million in 2011) were screened for severe hypoglycaemia. Anti‐hyperglycaemic agents were identified by their Anatomical Therapeutic Chemical code, and defined daily doses of each medication were calculated.

Results

The severe hypoglycaemic event rate was 460 per 100,000 people/year in 2006 and 490 per 100,000 people/year in 2011. In 2006 and 2011, 10.9% and 7.3%, respectively, of all people with severe hypoglycaemia were on sulfonylureas, while 12.7% and 9.3%, respectively, were on a combination therapy of metformin and sulfonylureas. Among those with severe hypoglycaemia, there were no prescriptions of dipeptidyl peptidase‐4 inhibitors or glucagon‐like peptide‐1 receptor agonists in 2006, but in 2011, 1.55% and 0.17%, of those with severe hypoglycaemia were receiving the respective treatments. In 2006 vs 2011, human insulin was prescribed for 11.3% vs 10.3% of people with severe hypoglycaemia, while insulin analogues were prescribed for 5.4% vs 8.1%, and mixed human insulins for 19.7% vs 14.0% of patients with severe hypoglycaemia. People receiving insulin analogue therapy had a higher risk of severe hypoglycaemia than those receiving metformin, after adjusting for age, gender, nephropathy diagnosis and year of survey (odds ratio 14.6; CI 13.3–15.9).

Conclusion

The incidence of severe hypoglycaemic events in Germany increased between 2006 and 2011, despite increased use of newer anti‐hyperglycaemic agents and decreased use of insulins.
A unified theory of forward‐ and backward‐looking M&As and divestitures
Authors: Ma Qing , Wang Susheng
Published: June 2017

In a unified theory of forward‐ and backward‐looking mergers and acquisitions (M&As) and divestitures, an M&A today may be a cause for a divestiture in the future; conversely a divestiture today may be a consequence of an M&A in the past. M&As and divestitures are not only two sides of the same coin, they are also causes and consequences of each other. In this paper, in a two‐period model, two firms consider integrating or separating in each period. We analyze forward‐ and backward‐looking M&As and divestitures, and compare them with static M&As and divestitures.
The effect of content and language integrated learning programmes' intensity on English proficiency: A longitudinal study
Authors: Merino Jon Ander , Lasagabaster David
Published: June 2017

Content and language integrated learning (CLIL) is becoming a very popular approach in Europe and many other parts of the world. However, due to the novelty of its implementation the number of longitudinal studies is scant. With this in mind, the overall aim of this study was to examine the effect of CLIL sessions and their intensity on the learning of English as a foreign language. Two test rounds were conducted in a longitudinal study spanning one year. The participants were 393 secondary education students enrolled in both bilingual and monolingual regions in Spain. Our findings revealed a significant impact of the number of CLIL sessions on students' proficiency in English.
The association between question type and the outcomes of a Dermatology eConsult service
Authors: O'Toole Ashley , Joo Jiyeh , DesGroseilliers Jean‐Pierre , Liddy Clare , Glassman Steven , Afkham Amir , Keely Erin
Published: June 2017

Background

eConsult is a web based service that facilitates communication between primary care providers (PCPs) and specialists, which can reduce the need for face‐to‐face consultations with specialists. One example is the Champlain BASE (Building Access to Specialist through eConsultation) service with dermatology being the largest specialty consulted.

Methods

Dermatology eConsults submitted from July 2011 to January 2015 were reviewed. Post eConsult surveys for PCPs were analyzed to determine the number of traditional consults avoided and perceived value of eConsults. The time it took the PCP to receive a reply and the amount of time reported by the specialist to answer eConsult were proactively recorded and analyzed. A subset of 154 most recent eConsults was categorized for dermatology content and question type (e.g. diagnosis or management) using a validated taxonomy.

Results

A total of 965 eConsults were directed to dermatology from 217 unique PCPs. The majority of eConsults (64%) took the specialist between 10 and 15 minutes to answer. The overall value of this service to the provider was rated as very good or excellent in 95% of cases. In 49%, traditional in‐person assessments were avoided. In the subset of the most recent cases, diagnosis was the most common question type asked (65.2%) followed by management (29%) and drug treatment (10.6%). The top five subject areas (40%) were: Dermatitis, Infections, Neoplasm, Nevi, and Pruritus.

Conclusion

eConsults was feasible and well received by PCPs, which improves access to dermatology care with a potential to reduce wait times for traditional consultation.
Early relapse of psoriasis after stopping brodalumab: a retrospective cohort study in 77 patients
Authors: Masson Regnault M. , Konstantinou M.‐P. , Khemis A. , Poulin Y. , Bourcier M. , Amelot F. , Bulaï Livideanu C. , Paul C.
Published: June 2017

Background

Biological agents targeting IL‐17 are very effective for clearing moderate to severe psoriasis. There is limited information regarding the frequency and pattern of psoriasis relapse upon treatment cessation.

Objective

To investigate the pattern of psoriasis recurrence in patients who were treated with brodalumab following Amgen's decision to stop the clinical programme in June 2015.

Materials and methods

Between June 2015 and March 2016, we constructed a retrospective multicenter cohort study including patients who were treated with brodalumab in Amgen's protocols after the abrupt interruption of the drug development programme. The relapse was defined as the request of patient to initiate a new treatment after brodalumab withdrawal.

Results

Seventy‐seven patients were followed up. At the time brodalumab treatment was stopped, 67 (87%) patients had reached PASI 90. After brodalumab discontinuation, all 77 patients relapsed after a follow‐up of 9 months. The median time to relapse was 46 days (range 7–224 days). Concerning the type of relapse, 73 patients presented with plaque psoriasis, one patient presented with erythrodermic psoriasis, and three patients experienced pustular psoriasis. In seven patients who had no previous history of psoriatic arthritis (PsA), the relapse of psoriasis was associated with inflammatory joint pain suggestive of PsA. At week 36, eight patients who had a limited relapse were controlled with topical treatment, 43 patients received a biological agent, two patients were included in a clinical trial with an investigational drug and 15 patients were treated with conventional systemic agents.

Conclusion

Abrupt cessation of brodalumab is associated with a rapid relapse of psoriasis with some patients experiencing a rebound. It seems not advisable to stop treatment with IL‐17 receptor antagonists abruptly even in patients who experience complete clearance of psoriasis.
Global Life Cycle Paper Flows, Recycling Metrics, and Material Efficiency
Authors: Van Ewijk Stijn , Stegemann Julia A. , Ekins Paul
Published: June 2017

Despite major improvements in recycling over the last decades, the pulp and paper sector is a significant contributor to global greenhouse gas emissions and other environmental pressures. Further reduction of virgin material requirements and environmental impacts requires a detailed understanding of the global material flows in paper production and consumption. This study constructs a Sankey diagram of global material flows in the paper life cycle, from primary inputs to end‐of‐life waste treatment, based on a review of publicly available data. It then analyzes potential improvements in material flows and discusses recycling and material efficiency metrics. The article argues that the use of the collection rate as a recycling metric does not directly stimulate avoidance of virgin inputs and associated impacts. An alternative metric compares paper for recycling (recovered paper) with total fibrous inputs and indicates that the current rate is at just over half of the technical potential. Material efficiency metrics are found to be more useful if they relate to the reuse potential of wastes. The material balance developed in this research provides a solid basis for further study of global sustainable production and consumption of paper. The conclusions on recycling and efficiency should be considered for improving environmental assessment and stimulating a shift toward resource efficiency and the circular economy.
The Development of Sensitivity to Grammatical Violations in American Sign Language: Native Versus Nonnative Signers
Authors: Novogrodsky Rama , Henner Jon , Caldwell‐Harris Catherine , Hoffmeister Robert
Published: June 2017

Factors influencing native and nonnative signers’ syntactic judgment ability in American Sign Language (ASL) were explored for 421 deaf students aged 7;6–18;5. Predictors for syntactic knowledge were chronological age, age of entering a school for the deaf, gender, and additional learning disabilities. Mixed‐effects linear modeling analysis revealed main effects of each predictor and an interaction between signing status and learning disability. The native signers showed typical syntactic development that varied by chronological age, gender, additional learning disabilities, and age of entering a deaf school. In contrast, the syntactic development of nonnative signers was more variable. It was less tightly related to chronological age and more strongly influenced by the age at which they had entered the school where assessment occurred, which was highly related to length of exposure to a sign language.
Security, ethnicity, nationalism
Authors: Neumann Iver B.
Published: June 2017

Using Slavic examples, the article looks at the nationalism/security nexus present today between the birth of ethnicities (early middle ages) and the birth of nationalism (eighteenth century). I discuss how Slavic ethnicity emerged in Greek and Roman security thinking. Others were classified in terms ofethnoiand were then interpellated into this self‐understanding. If ethnicity is an identity for the Other, then nationalism is an identity for the Self. It becomes a security concern not to order the Other polity's identity, as did the Byzantines, but to see to it that groups that may threaten your own nationalism – minorities, imperial subjects – cannot embrace nationalism. The policy of denying nationhood to minorities must be understood amongst other things as security policy. The organic understanding of the nation as young and vital demonstrates a third interstice between security and nationalism. If the young and vital nation is to grow and expand at the expense of the old and tired, then the polity that represents itself as a young and vital nation is by dint of that representation alone a security threat against those that they represent as old and tired. Finally, I discuss how this theme is played out in today's Russia
Balls on walls, feet on streets: Subversive play in Grand Ducal Florence
Authors: Wood Kelli
Published: June 2017

This article draws attention to the social and political import of balls games and acts of play in the urban space of Grand Ducal Florence. At the same time that the Medici were commissioning artworks that rhetorically promoted a unified identity of Florence and a spectre of control over the city space through the apparatus of public games like calcio in livrea, young men engaged in transitory activities of play in the street that contributed to community identity and belonging in space. Teasing out the transgressive and political potential of the ludic apart from and apart of the festal demonstrates how games in the city produced moments of community in an early modern public sphere‐ a sphere carved out through use of and performance in urban space, a sphere sometimes contending with and in contention with legislation, control, and authority by the Grand Duchy. Play shaped the production, use, and meaning of the urban environment both in daily life and during special events. In turn, the city's socially invested topography contributed to the construction of Florentine identity, within, between, and beyond factions.
Benchmarking Discount Rate in Natural Resource Damage Assessment with Risk Aversion
Authors: Wu Desheng , Chen Shuzhen
Published: June 2017

Benchmarking a credible discount rate is of crucial importance in natural resource damage assessment (NRDA) and restoration evaluation. This article integrates a holistic framework of NRDA with prevailing low discount rate theory, and proposes a discount rate benchmarking decision support system based on service‐specific risk aversion. The proposed approach has the flexibility of choosing appropriate discount rates for gauging long‐term services, as opposed to decisions based simply on duration. It improves injury identification in NRDA since potential damages and side‐effects to ecosystem services are revealed within the service‐specific framework. A real embankment case study demonstrates valid implementation of the method.
A Semiparametric Regression Model for Longitudinal Data with Non‐stationary Errors
Authors: Li Rui , Leng Chenlei , You Jinhong
Published: June 2017

Motivated by the need to analyze the National Longitudinal Surveys data, we propose a new semiparametric longitudinal mean‐covariance model in which the effects on dependent variable of some explanatory variables are linear and others are non‐linear, while the within‐subject correlations are modelled by a non‐stationary autoregressive error structure. We develop an estimation machinery based on least squares technique by approximating non‐parametric functions via B‐spline expansions and establish the asymptotic normality of parametric estimators as well as the rate of convergence for the non‐parametric estimators. We further advocate a new model selection strategy in the varying‐coefficient model framework, for distinguishing whether a component is significant and subsequently whether it is linear or non‐linear. Besides, the proposed method can also be employed for identifying the true order of lagged terms consistently. Monte Carlo studies are conducted to examine the finite sample performance of our approach, and an application of real data is also illustrated.
Construction of automorphisms of hyperkähler manifolds
Authors: Amerik Ekaterina , Verbitsky Misha
Published: June 2017

Let $M$ be an irreducible holomorphic symplectic (hyperkähler) manifold. If $b_{2}(M)\geqslant 5$, we construct a deformation $M^{\prime }$ of $M$ which admits a symplectic automorphism of infinite order. This automorphism is hyperbolic, that is, its action on the space of real $(1,1)$-classes is hyperbolic. If $b_{2}(M)\geqslant 14$, similarly, we construct a deformation which admits a parabolic automorphism (and many other automorphisms as well).
The existence of Zariski dense orbits for polynomial endomorphisms of the affine plane
Authors: Xie Junyi
Published: June 2017

In this paper we prove the following theorem. Let$f$be a dominant polynomial endomorphism of the affine plane defined over an algebraically closed field of characteristic$0$. If there is no nonconstant invariant rational function under$f$, then there exists a closed point in the plane whose orbit under$f$is Zariski dense. This result gives us a positive answer to a conjecture proposed by Medvedev and Scanlon, by Amerik, Bogomolov and Rovinsky, and by Zhang for polynomial endomorphisms of the affine plane.
Small eigenvalues of surfaces of finite type
Authors: Ballmann Werner , Matthiesen Henrik , Mondal Sugata
Published: June 2017

Extending our previous work on eigenvalues of closed surfaces and work of Otal and Rosas, we show that a complete Riemannian surface $S$ of finite type and Euler characteristic $\unicode[STIX]{x1D712}(S)<0$ has at most $-\unicode[STIX]{x1D712}(S)$ small eigenvalues.
Mechanisms underlying vestibulo‐cerebellar motor learning in mice depend on movement direction
Authors: Voges Kai , Wu Bin , Post Laura , Schonewille Martijn , De Zeeuw Chris I.
Published: June 2017

Key points

Directionality, inherent to movements, has behavioural and neuronal correlates.

Direction of vestibular stimulation determines motor learning efficiency.

Vestibulo‐ocular reflex gain–increase correlates with Purkinje cell simple spike potentiation.

The locus of neural correlates for vestibulo‐ocular reflex adaptation is paradigm specific.

Compensatory eye movements elicited by head rotation, also known as vestibulo‐ocular reflex (VOR), can be adapted with the use of visual feedback. The cerebellum is essential for this type of movement adaptation, although its neuronal correlates remain to be clarified. In the present study, we show that the direction of vestibular input determines the magnitude of eye movement adaptation induced by mismatched visual input in mice, with larger changes during contraversive head rotation. Moreover, the location of the neural correlate of this changed behaviour depends on the type of paradigm. Gain–increase paradigms induce increased simple spike (SS) activity in ipsilateral cerebellar Purkinje cells (PC), which is in line with eye movements triggered by optogenetic PC activation. By contrast, gain–decrease paradigms do not induce changes in SS activity, indicating that the murine vestibulo‐cerebellar cortical circuitry is optimally designed to enhance ipsiversive eye movements.
Dynamics of a Leidenfrost Droplet Modulated by Electrowetting
Authors: Lu Yi , Fang Hui , Bao Jiming , Liu Dong
Published: June 2017

Leidenfrost phenomenon is closely related to film boiling and the critical heat flux (CHF) limit of boiling heat transfer. Understanding the mechanisms of Leidenfrost phenomenon and devising effective ways to suppress it is of great interest to the heat transfer enhancement community. In this work, a synchronized high-speed optical imaging and infrared (IR) thermography approach was employed to investigate the dynamics of a Leidenfrost droplet under the influence of electrowetting (EW). The Leidenfrost droplet was produced by dispensing a water drop on a Teflon-coated silicon wafer maintained at a wall temperature of Twall = 200 °C. Both direct-current (DC) and alternating-current (AC) electric fields were applied to induce EW effect to suppress the Leidenfrost state. The interfacial instabilities of the Leidenfrost droplet were observed, and the instantaneous temperature and heat flux distributions on the heating surface were measured. The results suggest that the electrical forces destabilize the liquid-vapor interface and cause the vapor film that insulates the heating surface from the droplet to collapse. Re-establishment of the liquid-solid contact helps to drastically improve the heat transfer, as evidenced by the reduced surface temperature and the enhanced heat flux.
Nucleate Boiling Heat Transfer on Plain and Microporous Surfaces in Subcooled Water
Authors: Juna Seongchul , Kima Jinsub , Yeol Kimb Hwan , M. Youa Seung
Published: June 2017

The growth of hovering bubbles on Copper, High-Temperature Thermally-Conductive Microporous Coating (Cu-HTCMC) and plain surface were compared at 1,000 kW/m2 in nucleate boiling with different subcoolings. Images obtained by a high speed camera operating at 2,000 frames per second were used. The Cu-HTCMC was created by sintering copper powders with the average particle size of 67 μm and ∼300 μm thickness, which showed the optimized nucleate boiling and critical heat flux enhancement. The hovering bubble size became smaller as subcooling increased for both Cu-HTCMC and plain surface due to condensation by surrounding subcooled water. At 30 K subcooling, big hovering bubbles disappeared on both surfaces. Small bubbles were shown on plain surface and mists were shown on Cu-HTCMC surface. The hovering bubble sizes were close and the growth times were comparable for both surfaces in saturated and 10 K subcooling cases. However, the bubbles on Cu-HTCMC surface were smaller than those of plain surface at 20 K and 30 K subcoolings. This is believed to be due to the microporous structures shown in the SEM image (top left figure). The heat transfer coefficients of Cu-HTCMC were ∼300 kW/m2K for various subcoolings, about 6 times higher than those of plain surface (top right figure). The figure indicates slightly increasing trend of the heat transfer coefficient with subcooling. This is believed to be the result of the disappearance of relatively big size bubbles in Cu-HTCMC case.
Numerical Simulation of Evaporating Two-Phase Flow in a High-Aspect-Ratio Microchannel with Bends
Authors: Girard Adam , M. You Seung , Garimella Suresh V.
Published: June 2017

Flow boiling was investigated on a hydrophobic surface by coating Teflon® onto a 1×1 cm2 copper surface, resulting in contact angle of 118°. The images depicted were taken using distilled water flowing at 299 kg/m2s with 3°C subcooling. In the first series, the number of active nucleation sites increased as heat flux increased. For lower values of heat flux (< 80 kW/m2), vapor bubbles remained almost stationary on the surface. The hydrophobic contact angle makes the horizontal component of surface tension force act radially outward, causing the bubble interface to grow. This leads to increased triple contact line and increased vertical component surface force. The buoyancy force due to the vapor bubble volume appears to be insufficient to overcome this vertical force for liftoff. This explains the stationary bubbles observed at the lower heat fluxes. The bubbles show an increase in size and number with heat flux. After this increasing trend, the bubble continues to grow larger when heat flux is higher than 80 kW/m2, eventually leading to the dryout at 117.5 kW/m2. The later bubble growth at high heat fluxes is caused primarily by the coalescences of neighboring bubbles. These larger bubbles are more affected by flow induced drag forces and move downstream. This can be seen in the lower sequential series at 100 kW/m2. The larger vapor masses slide across the surface, continue to absorb smaller bubbles as they move downstream, and are swept off the surface.
Multimodal Surface Instabilities in Curved Film–Substrate Structures
Authors: Zhao Ruike , Zhao Xuanhe
Published: June 2017

Structures of thin films bonded on thick substrates are abundant in biological systems and engineering applications. Mismatch strains due to expansion of the films or shrinkage of the substrates can induce various modes of surface instabilities such as wrinkling, creasing, period doubling, folding, ridging, and delamination. In many cases, the film–substrate structures are not flat but curved. While it is known that the surface instabilities can be controlled by film–substrate mechanical properties, adhesion and mismatch strain, effects of the structures’ curvature on multiple modes of instabilities have not been well understood. In this paper, we provide a systematic study on the formation of multimodal surface instabilities on film–substrate tubular structures with different curvatures through combined theoretical analysis and numerical simulation. We first introduce a method to quantitatively categorize various instability patterns by analyzing their wave frequencies using fast Fourier transform (FFT). We show that the curved film–substrate structures delay the critical mismatch strain for wrinkling when the system modulus ratio between the film and substrate is relatively large, compared with flat ones with otherwise the same properties. In addition, concave structures promote creasing and folding, and suppress ridging. On the contrary, convex structures promote ridging and suppress creasing and folding. A set of phase diagrams are calculated to guide future design and analysis of multimodal surface instabilities in curved structures.
Additive Manufacturing-Oriented Design of Graded Lattice Structures Through Explicit Topology Optimization
Authors: Liu Chang , Du Zongliang , Zhang Weisheng , Zhu Yichao , Guo Xu
Published: June 2017

In the present work, a new approach for designing graded lattice structures is developed under the moving morphable components/voids (MMC/MMV) topology optimization framework. The essential idea is to make a coordinate perturbation to the topology description functions (TDF) that are employed for the description of component/void geometries in the design domain. Then, the optimal graded structure design can be obtained by optimizing the coefficients in the perturbed basis functions. Our numerical examples show that the proposed approach enables a concurrent optimization of both the primitive cell and the graded material distribution in a straightforward and computationally effective way. Moreover, the proposed approach also shows its potential in finding the optimal configuration of complex graded lattice structures with a very small number of design variables employed under various loading conditions and coordinate systems.
Passive Suppression Mechanisms in Laminar Vortex-Induced Vibration of a Sprung Cylinder With a Strongly Nonlinear, Dissipative Oscillator
Authors: Blanchard Antoine , Bergman Lawrence A. , Vakakis Alexander F.
Published: June 2017

We study cross-flow vortex-induced vibration (VIV) of a linearly sprung circular cylinder equipped with a dissipative oscillator with cubic stiffness nonlinearity, restrained to move in the direction of travel of the cylinder. The dissipative, essentially nonlinear coupling between the cylinder and the oscillator allows for targeted energy transfer (TET) from the former to the latter, whereby the oscillator acts as a nonlinear energy sink (NES) capable of passively suppressing cylinder oscillations. For fixed values of the Reynolds number (Re = 48, slightly above the fixed-cylinder Hopf bifurcation), cylinder-to-fluid density ratio, and dimensionless cylinder spring constant, spectral-element simulations of the Navier–Stokes equations coupled to the rigid-body motion show that different combinations of NES parameters lead to different long-time attractors of the dynamics. We identify four such attractors which do not coexist at any given point in the parameter space, three of which lead to at least partial VIV suppression. We construct a reduced-order model (ROM) of the fluid–structure interaction (FSI) based on a wake oscillator to analytically study those four mechanisms seen in the high-fidelity simulations and determine their respective regions of existence in the parameter space. Asymptotic analysis of the ROM relies on complexification-averaging (CX-A) and slow–fast partition of the transient dynamics and predicts the existence of complete and partial VIV-suppression mechanisms, relaxation cycles, and Hopf and Shilnikov bifurcations. These outcomes are confirmed by numerical integration of the ROM and comparisons with spectral-element simulations of the full system.
An Eccentric Ellipse Failure Criterion for Amorphous Materials
Authors: Ding Bin , Li Xiaoyan
Published: June 2017

We proposed an eccentric ellipse criterion to describe the failure of amorphous materials under a combination of normal stress σ and shear stress τ. This criterion can reflect a tension–compression strength asymmetry, and unify four previous failure criteria in the σ–τ stress space, including von Mises criterion, Drucker–Prager criterion, Christensen criterion, and ellipse criterion. We examined the validity of the eccentric ellipse criterion in the tensile-shear failure regimes using the results from our atomistic simulations for two typical amorphous CuZr and LiSi, and recent tension–torsion experiments on metallic glasses. The predictions from the eccentric ellipse criterion agree well with these results from atomistic simulations and experiments. It indicates that this eccentric ellipse criterion is essential for the tensile-shear failure of amorphous materials.
Recursive System Identification and Simulation of Model Predictive Control Based on Experimental Data to Control the Cathode Side Parameters of the Hybrid Fuel Cell/Gas Turbine
Authors: Restrepo Bernardo , Tucker David , Banta Larry E.
Published: June 2017

A model predictive control (MPC) strategy has been suggested and simulated with the empirical dynamic data collected on the hybrid performance (HyPer) project facility installed at the National Energy Technology Laboratory (NETL), U.S. Department of Energy, in Morgantown, WV. The excursion dynamic data collected between the setup changes of the actuators on the cathode side of the HyPer facility were processed offline to determine the feasibility of applying an adaptive model predictive control strategy. Bypass valves along with electric load (EL) of the system were manipulated, and variables such as turbine speed, mass flow, temperature, pressure of the cathode side, among others were recorded for analysis. The three main phases of the MPC, identification of the models, control design, and control tuning have been described. Two identification structures, autoregressive exogenous (ARX) and a state-space model, were used to fit the measured data to dynamic models of the facility. The system identification ARX model required around 0.12 s of computer time. The state-space identification algorithm spent around 0.65 s, which was relatively high considering that the sample time of the sensors was 0.4 s. Visual inspection of the tracking accuracy showed that the ARX approach was approximately as accurate as the state-space structure in its ability to reproduce measured data. However, by comparing the loss function and the final prediction error (FPE) parameters, the state-space approach gives better results. For the ARX/state-space models, the MPC was robust in tracking setpoint variations. The MPC strategy described here offers potential to be the way to control the HyPer facility. One of the strengths of MPC is that it can allow the designer to impose strict limits on inputs and outputs in order to keep the system within known safe bounds. Constraints are highly present in the HyPer facility. The constraint airflow valves and the electric load were used in the simulation to control the constraint turbine speed and the cathode airflow (CAF). The MPC also displayed good disturbance rejection on the output variables when the fuel flow was set to simulate fuel cell (FC) heat effluent disturbances. Different off-design scenarios of operation were tested to confirm the estimated implementation behavior of the plant-controller dynamics. One drawback in MPC implementation is the computational time consuming between calculations and will be considered for future studies.
Effect of Recess Shape on the Performance of a High-Speed Hybrid Journal Bearing
Authors: Untaroiu Alexandrina , Fu Gen
Published: June 2017

Hybrid bearings are getting more and more attention because of their ability to provide both hydrodynamic support for high-speed rotors and hydrostatic lift in low-speed conditions such as during startup. Hybrid bearings are typically designed with recess grooves to modify the pressure profile and as a result to enable the lift capacity of the bearing under various operating conditions. The literature has shown that the size and shape of the recesses have not been systematically and quantitatively studied in detail. The goal of this study is to build a 3D analytical model for a hybrid-recessed bearing with five pockets and provide a comprehensive analysis for the effect of recess geometry on the overall performance of the bearing. In this study, a baseline model selected from the literature is constructed and validated using the ANSYS cfx computational fluid dynamics software package. A sensitivity analysis of the design variables on the performance of the bearing has been performed using design expert software. The length, width, and depth of the recess as well as the diameter and location of the five inlet ports have been selected as design variables. A multivariable and multi-objective genetic algorithm has also been solved using isight software with the goal of optimizing the geometry of the recess to maximize load capacity while minimizing bearing power loss from friction torque. The results of the baseline model show reasonable agreement with the experimental data published in the literature. The regression models for lift force and friction torque were both found to be statistically significant and accurate. It has been shown that friction torque decreases as the length of recess in the circumferential direction increases. The results showed that the load capacity is highly correlated to the diameter of the orifice, d. These results provide a deeper understanding of the relationship between the shape of the recess and bearing performance and are expected to be useful in practical hybrid-bearing design.
A Combined Organic Rankine Cycle With Double Modes Used for Internal Combustion Engine Waste Heat Recovery
Authors: Zhu Guohui , Liu Jingping , Fu Jianqin , Wang Shuqian
Published: June 2017

A combined organic Rankine cycle (ORC) was proposed for both engine coolant energy recovery (CER) and exhaust energy recovery (EER), and it was applied to a gasoline direct injection (GDI) engine to verify its waste heat recovery (WHR) potential. After several kinds of organic working medium were compared, R123 was selected as the working fluid of this ORC. Two cycle modes, low-temperature cycle and high-temperature cycle, were designed according to the evaporation way of working fluid. The working fluid is evaporated by coolant heat in low-temperature cycle but by exhaust heat in high-temperature cycle. The influence factors of cycle performance and recovery potential of engine waste heat energy were investigated by cycle simulation and parametric analysis. The results show that recovery efficiency of waste heat energy is influenced by both engine operating conditions and cycle parameters. At 2000 r/min, the maximum recovery efficiency of waste heat energy is 7.3% under 0.2 MPa brake mean effective pressure (BMEP) but 10.7% under 1.4 MPa BMEP. With the combined ORC employed, the fuel efficiency improvement of engine comes up to 4.7% points under the operations of 2000 r/min and 0.2 MPa BMEP, while it further increases to 5.8% points under the operations of 2000 r/min and 1.4 MPa BMEP. All these indicate that the combined ORC is suitable for internal combustion (IC) engine WHR.
Different Resistance Mechanisms for Cadazolid and Linezolid in Clostridium difficile Found by Whole-Genome Sequencing Analysis
Authors: Caspers Patrick , Locher Hans H. , Pfaff Philippe , Diggelmann Sarah , Rueedi Georg , Bur Daniel , Ritz Daniel
Published: June 2017

Cadazolid (CDZ) is a new antibiotic currently in clinical development for the treatment of
Clostridium difficile
infections. CDZ interferes with the bacterial protein synthesis machinery. The aim of the present study was to identify resistance mechanisms for CDZ and compare the results to those obtained for linezolid (LZD) in
C. difficile
by whole-genome sequencing (WGS) of strains generated by
in vitro
passages and to those obtained for LZD-resistant clinical isolates. Clones of
C. difficile
630 selected with CDZ during 46 passages had a maximally 4-fold increase in CDZ MIC, while the LZD MIC for clones selected with LZD increased up to 16-fold. CDZ cross-resistance with LZD was maximally 4-fold, and no cross-resistance with other antibiotics tested was observed. Our data suggest that there are different resistance mechanisms for CDZ and LZD in
C. difficile
. Mutations after passages with CDZ were found in
rplD
(ribosomal protein L4) as well as in
tra
and
rmt
, whereas similar experiments with LZD showed mutations in
rplC
(ribosomal protein L3),
reg
, and
tpr
, indicating different resistance mechanisms. Although high degrees of variation between the sequenced genomes of the clinical isolates were observed, the same mutation in
rplC
was found in two clinical isolates with high LZD MICs. No mutations were found in the 23S rRNA genes, and attempts to isolate the
cfr
gene from resistant clinical isolates were unsuccessful. Analysis of 50% inhibitory concentrations (IC
50
s) determined in
in vitro
transcription/translation assays performed with
C. difficile
cell extracts from passaged clones correlated well with the MIC values for all antibiotics tested, indicating that the ribosomal mutations are causing the resistant phenotype.
Initial Treatment of Cancer Patients with Fluconazole-Susceptible Dose-Dependent Candida glabrata Fungemia: Better Outcome with an Echinocandin or Polyene Compared to an Azole?
Authors: Le Audrey , Farmakiotis Dimitrios , Tarrand Jeffrey J. , Kontoyiannis Dimitrios P.
Published: June 2017

The 28-day crude mortality rate in 68 cancer patients with fluconazole-susceptible dose-dependent
Candida glabrata
fungemia started on treatment (within 48 h after blood culture collection) with an echinocandin or liposomal amphotericin-B was better (30%) than those treated with azole monotherapy (52%) (
P
= 0.07). After adjusting for confounders, azole monotherapy also was associated with worse 28-day survival (hazard ratio, 3.8;
P
= 0.003).
Genomic Analysis of Multidrug-Resistant Escherichia coli from North Carolina Community Hospitals: Ongoing Circulation of CTX-M-Producing ST131-
H
30Rx and ST131-
H
30R1 Strains
Authors: Kanamori Hajime , Parobek Christian M. , Juliano Jonathan J. , Johnson James R. , Johnston Brian D. , Johnson Timothy J. , Weber David J. , Rutala William A. , Anderson Deverick J.
Published: June 2017

Escherichia coli
sequence type 131 (ST131) predominates globally among multidrug-resistant (MDR)
E. coli
strains. We used whole-genome sequencing (WGS) to investigate 63 MDR
E. coli
isolates from 7 North Carolina community hospitals (2010 to 2015). Of these, 39 (62%) represented ST131, including 37 (95%) from the ST131-
H
30R subclone: 10 (27%) from its
H
30R1 subset and 27 (69%) from its
H
30Rx subset. ST131 core genomes differed by a median of 15 (range, 0 to 490) single-nucleotide variants (SNVs) overall versus only 7 within
H
30R1 (range, 3 to 12 SNVs) and 11 within
H
30Rx (range, 0 to 21). The four isolates with identical core genomes were all
H
30Rx. Epidemiological and clinical characteristics did not vary significantly by strain type, but many patients with MDR
E. coli
or
H
30Rx infection were critically ill and had poor outcomes.
H
30Rx isolates characteristically exhibited fluoroquinolone resistance and CTX-M-15 production, had a high prevalence of trimethoprim-sulfamethoxazole resistance (89%),
sul1
(89%), and
dfrA17
(85%), and were enriched for specific virulence traits, and all qualified as extraintestinal pathogenic
E. coli
. The high overall prevalence of CTX-M-15 appeared to be possibly attributable to its association with the ST131-
H
30Rx subclone and IncF[F2:A1:B−] plasmids. Some phylogenetically clustered non-ST131 MDR
E. coli
isolates also had distinctive serotypes/
fimH
types, fluoroquinolone mutations, CTX-M variants, and IncF types. Thus, WGS analysis of our community hospital source MDR
E. coli
isolates suggested ongoing circulation and differentiation of
E. coli
ST131 subclones, with clonal segregation of CTX-M variants, other resistance genes, Inc-type plasmids, and virulence genes.
Micafungin Plasma Levels Are Not Affected by Continuous Renal Replacement Therapy: Experience in Critically Ill Patients
Authors: Vossen M. G. , Knafl D. , Haidinger M. , Lemmerer R. , Unger M. , Pferschy S. , Lamm W. , Maier-Salamon A. , Jäger W. , Thalhammer F.
Published: June 2017

Critically ill patients often experience acute kidney injury and the need for renal replacement therapy in the course of their treatment in an intensive care unit (ICU). These patients are at an increased risk for candidiasis. Although there have been several reports of micafungin disposition during renal replacement therapy, to this date there are no data describing the elimination of micafungin during high-dose continuous venovenous hemodiafiltration with modified AN69 membranes. The aim of this prospective open-label pharmacokinetic study was to assess whether micafungin plasma levels are affected by continuous hemodiafiltration in critical ill patients using the commonly employed AN69 membrane. A total of 10 critically ill patients with micafungin treatment due to suspected or proven candidemia were included in this trial. Prefilter/postfilter micafungin clearance was measured to be 46.0 ml/min (±21.7 ml/min;
n
= 75 individual time points), while hemofilter clearance calculated by the sieving coefficient was 0.0038 ml/min (±0.002 ml/min;
n
= 75 individual time points). Total body clearance was measured to be 14.0 ml/min (±7.0 ml/min;
n
= 12). The population area under the curve from 0 to 24 h (AUC
0–24
) was calculated as 158.5 mg · h/liter (±79.5 mg · h/liter;
n
= 13). In spite of high protein binding, no dose modification is necessary in patients receiving continuous venovenous hemodiafiltration with AN69 membranes. A dose elevation may, however, be justified in certain cases. (This study has been registered at ClinicalTrials.gov under identifier NCT02651038.)
BosR Is A Novel Fur Family Member Responsive to Copper and Regulating Copper Homeostasis in Borrelia burgdorferi
Authors: Wang Peng , Yu Zhuoteng , Santangelo Thomas J. , Olesik John , Wang Yufeng , Heldwein Ekaterina , Li Xin
Published: June 2017

The ferric uptake regulator (Fur) family of DNA-binding proteins represses and/or activates gene transcription via divalent metal ion-dependent signal sensing. The
Borrelia burgdorferi
Fur homologue, also known as
Borrelia
oxidative stress regulator (BosR), promotes spirochetal adaptation to the mammalian host by directly repressing the lipoproteins required for tick colonization and indirectly activating those required for establishing infection in the mammal. Here, we examined whether the DNA-binding activity of BosR was regulated by any of the four most prevalent transition metal ions in
B. burgdorferi
, Mn, Fe, Cu, and Zn. Our data indicated that in addition to a structural site occupied by Zn(II), BosR had two regulatory sites that could be occupied by Zn(II), Fe(II), or Cu(II) but not by Mn(II). While Fe(II) had no effect, Cu(II) and Zn(II) had a dose-dependent inhibitory effect on the BosR DNA-binding activity. Competition experiments indicated that Cu(II) had a higher affinity for BosR than Zn(II) or Fe(II). A BosR deficiency in
B. burgdorferi
resulted in a significant increase in the Cu level but no significant change in the levels of Mn, Fe, or Zn. These data suggest that Cu regulates BosR activity, and BosR in turn regulates Cu homeostasis in
B. burgdorferi
. While this regulatory paradigm is characteristic of the Fur family, BosR is the first one shown to be responsive to Cu(II), which may be an adaptation to the potentially high level of Cu present in the Lyme disease spirochete.

IMPORTANCE
Transition metal ions serve an essential role in the metabolism of all living organisms. Members of the ferric uptake regulator (Fur) family play critical roles in regulating the cellular homeostasis of transition metals in diverse bacteria, and their DNA-binding activity is often regulated by coordination of the cognate divalent metal ions. To date, regulators with metal ion specificity to Fe(II), Mn(II), Zn(II), and Ni(II) have all been described. In this study, we demonstrate that BosR, the sole Fur homologue in
Borrelia burgdorferi
, is responsive to Cu(II) and regulates Cu homeostasis in this bacterium, which may be an adaption to potentially Cu-rich milieu in the Lyme disease spirochete. This study has expanded the repertoire of the Fur family's metal ion specificity.