bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation of mechanical force by grafted polyelectrolytes in an electric field: application to polyelectrolyte-based nano-devices
Authors: Brilliantov N. V. , Budkov Yu. A. , Seidel C.
Published: October 2016

We analyse theoretically and by means of molecular dynamics (MD) simulations the generation of mechanical force by a polyelectrolyte (PE) chain grafted to a plane. The PE is exposed to an external electric field that favours its adsorption on the plane. The free end of the chain is linked to a deformable target body. By varying the field, one can alter the length of the non-adsorbed part of the chain. This entails variation of the deformation of the target body and hence variation of the force arising in the body. Our theoretical predictions for the generated force are in very good agreement with the MD data. Using the theory developed for the generated force, we study the effectiveness of possible PE-based nano-vices, composed of two clenching planes connected by PEs and exposed to an external electric field. We exploit the Cundall–Strack solid friction model to describe the friction between a particle and the clenching planes. We compute the diffusion coefficient of a clenched particle and show that it drastically decreases even in weak applied fields. This demonstrates the efficacy of the PE-based nano-vices, which may be a possible alternative to the existing nanotube nano-tweezers and optical tweezers.

This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’.
On the Effectiveness of Event-related Beta tACS on Episodic Memory Formation and Motor Cortex Excitability
Authors: Braun Verena , Sokoliuk Rodika , Hanslmayr Simon
Published: October 2016

Background

Transcranial alternating current stimulation (tACS) is widely used to entrain or modulate brain oscillations in order to investigate causal relationships between oscillations and cognition.

Objective

In a series of experiments we here addressed the question of whether event-related, transient tACS in the beta frequency range can be used to entrain beta oscillations in two different domains: episodic memory formation and motor cortex excitability.

Methods

In experiments 1 and 2, 72 healthy human participants engaged in an incidental encoding task of verbal and non-verbal material while receiving tACS to the left and right inferior frontal gyrus (IFG) at 6.8Hz, 10.7Hz, 18.5Hz, 30Hz, 48Hz and sham stimulation for 2s during stimulus presentation.

In experiment 3, tACS was administered to M1 at the individual motor beta frequency of eight subjects. We investigated the relationship between the size of TMS induced MEPs and tACS phase.

Results

Beta tACS did not affect memory performance compared to sham stimulation in experiments 1 and 2. Likewise, in experiment 3, MEP size was not modulated by the tACS phase.

Conclusions

Our findings suggest that event-related, transient tACS in the beta frequency range cannot be used to modulate the formation of episodic memories or motor cortex excitability. These null-results question the effectiveness of event-related tACS to entrain beta oscillations and modulate cognition.
Strategic Revenue Sharing with Daily Deal Sites: A Competitive Analysis
Authors: Bhardwaj Pradeep , Sajeesh S.
Published: October 2016

Promoting through daily deal sites has become popular in the past few years. Groupon is perhaps the best known provider of these promotions (also known as online discount vouchers) to customers. Daily deals differ from traditional coupons on three important dimensions: (i) They are not offered to consumers directly by firms but are offered through an intermediary, (ii) the promotional depth offered by these localized promotions tends to be higher, and (iii) consumers prepay for the discount vouchers, and then the daily deals site reimburses the retailer a prespecified negotiated percentage of each paid voucher. In this study, we build a theoretical model to explore the profitability of undertaking a daily deals campaign by firms. Our analysis identifies the role of types of consumers in the market, relative bargaining power of the local firms, revenue sharing agreements, and market characteristics, such as degree of product substitutability and extent of competition, on the profitability attained through daily deal promotions. Surprisingly, when demand spillovers exist, an asymmetric outcome, with one firm offering an online discount voucher and the competing firm not offering an online discount voucher, is an equilibrium under some conditions.
Use of time in a decision‐making process by a parasitoid
Authors: PARENT JEAN‐PHILIPPE , BRODEUR JACQUES , BOIVIN GUY
Published: October 2016

1. Time perception is seldom studied in invertebrates, with the limited experimental evidence being insufficient to provide a comprehensive pattern of the capacity of invertebrates to measure time and use it in decision‐making processes.

2. In this study, it was hypothesized that insect parasitoids have evolved the capacity to measure time precisely and to use it to optimize foraging decisions related to host exploitation. To examine time perception in females of the gregarious egg parasitoid Trichogramma euproctidis, the present study used their ability to adjust their investment (number of eggs laid) in a host to the initial transit duration (interval between the first contact with the host and the following contact with the substrate). Females utilize this method to assess host egg size, as a large egg necessarily requires more time to evaluate than a small host. In this study, the initial transit duration for a given sized egg was artificially extended by suspending it.

3. For similar sized hosts, female T. euproctidis significantly increased both oviposition duration and progeny allocation following a longer initial transit duration.

4. These results demonstrate the intrinsic capacity of this parasitoid to measure time and to adjust their progeny investment accordingly. This is believed to be one of the few demonstrations of a retrospective measure of time in an invertebrate.
Local depletion of glycogen with supramaximal exercise in human skeletal muscle fibres
Authors: Gejl Kasper D. , Ørtenblad Niels , Andersson Erik , Plomgaard Peter , Holmberg Hans‐Christer , Nielsen Joachim
Published: October 2016

Key points

Glycogen is stored in local spatially distinct compartments within skeletal muscle fibres and is the main energy source during supramaximal exercise.

Using quantitative electron microscopy, we show that supramaximal exercise induces a differential depletion of glycogen from these compartments and also demonstrate how this varies with fibre types.

Repeated exercise alters this compartmentalized glycogen depletion.

The results obtained in the present study help us understand the muscle metabolic dynamics of whole body repeated supramaximal exercise, and suggest that the muscle has a compartmentalized local adaptation to repeated exercise, which affects glycogen depletion.

Skeletal muscle glycogen is heterogeneously distributed in three separated compartments (intramyofibrillar, intermyofibrillar and subsarcolemmal). Although only constituting 3–13% of the total glycogen volume, the availability of intramyofibrillar glycogen is of particular importance to muscle function. The present study aimed to investigate the depletion of these three subcellular glycogen compartments during repeated supramaximal exercise in elite athletes. Ten elite cross‐country skiers (aged 25 ± 4 years, : 65 ± 4 ml kg−1 min−1; mean ± SD) performed four ∼4 min supramaximal sprint time trials (STT 1–4) with 45 min of recovery. The subcellular glycogen volumes in musculus triceps brachii were quantified from electron microscopy images before and after both STT 1 and 4. During STT 1, the depletion of intramyofibrillar glycogen was higher in type 1 fibres [−52%; (−89:−15%)] than type 2 fibres [−15% (−52:22%)] (P = 0.02), whereas the depletion of intermyofibrillar glycogen [main effect: −19% (−33:0%), P = 0.006] and subsarcolemmal glycogen [main effect: −35% (−66:0%), P = 0.03] was similar between fibre types. By contrast, only intermyofibrillar glycogen volume was significantly reduced during STT 4, in both fibre types [main effect: −31% (−50:−11%), P = 0.002]. Furthermore, for each of the subcellular compartments, the depletion of glycogen during STT 1 was associated with the volumes of glycogen before STT 1. In conclusion, the depletion of spatially distinct glycogen compartments differs during supramaximal exercise. Furthermore, the depletion changes with repeated exercise and is fibre type‐dependent.
Method for Direct Measurement of On-Axis Carbon Fiber Thermal Diffusivity Using the Laser Flash Technique
Authors: Craddock John D. , Burgess Jordan J. , Edrington Sarah E. , Weisenberger Matthew C.
Published: October 2016

Mechanical and thermal property values of carbon fiber-reinforced polymer (CFRP) composites are readily available. However, the small diameter and thermal anisotropy of the carbon filaments pose significant challenges for measuring thermal diffusivity of the constituent fibers. As a result, the literature describes many techniques to address this issue. Here, a new method for the direct, bulk measurement of on-axis thermal diffusivity of a matrix-free carbon fiber bundle is reported. Aligned carbon fiber tows were uniformly compacted into a collimated, cylindrical bundles using heat-shrink tubing, and fixed such that the fibers remained unwetted, in the center of an epoxy disk, which was subsequently analyzed for thermal diffusivity using laser flash analysis.
Single- and Two-Phase Particle Image Velocimetry Characterization of Fluid Flow Within a Liquid Immersion Cooled Electronics Module
Authors: Gess Joshua , Bhavnani Sushil , Wayne Johnson R.
Published: October 2016

With the growth and acceptance of liquid immersion cooling as a viable thermal management technique for high performance microelectronics, fundamental questions regarding the nature of the flow within the system will need to be addressed. Among these are how the coolant is directed toward components of primary interest as well as how other elements within the electronics package may affect the delivery of fluid to these more critical locations. The proposed study seeks to experimentally address these issues with particle image velocimetry (PIV) measurements of unheated and heated flow within an electronics enclosure. The effectiveness of three flow distribution designs at delivering coolant to elements of importance, in this case 6.45 cm2 (1 in.2) components meant to simulate processor chips, has been examined using the vectors yielded by the PIV experimentation in a control surface analysis around these critical components. While these previous scenarios are unheated, two-phase PIV has also been conducted with FC-72 as the working fluid while boiling is taking place. A control surface analysis around all four heated elements within the enclosure shows an expected roughly monotonic increase in the net liquid flow rate to the boiling elements as the power applied to them is increased. Additionally, discretized mapping of how the fluid is entering the area surrounding these boiling elements has been constructed to offer insight into how passive elements should be placed within an electronics enclosure so as to not obstruct or hinder the vital flow of coolant to the most critical components.
Optimization of a Thermoelectric Cooler for Time-Varying Heat Load and Sink Temperature
Authors: Pearson Matthew R. , Lents Charles E.
Published: October 2016

Thermoelectric coolers (TECs) are solid-state cooling devices that operate on the Seebeck effect. They can be used in electronic cooling applications as well as other refrigeration systems. Among the various factors that affect TEC performance within a system, it has been shown that the thermal conductance is an important parameter, which can also be easily altered during the design of a TEC to deliver optimal TEC performance for a given application. However, these studies have considered only a fixed heat load and heat sink temperature, whereas in many realistic applications these quantities can vary. A procedure has been developed for optimizing the thermal conductance of a TEC based on a typical operating cycle of time-varying heat load and sink temperature, while permitting constraints that ensure that one or more worst-case operating conditions can also be met. This procedure is valid for any arbitrary heat load and sink temperature functions; however, for illustrative purposes, a simple heat load function at fixed sink temperature (and a sink temperature function at fixed heat load) is used. The results show that the optimal conductance can strongly depend on the operating cycle, and the corresponding reduction in electrical input work (and corresponding increase in net coefficient of performance (COP)) can be significant.
Integrability of Velocity Constraints Modeling Vortex Shedding in Ideal Fluids
Authors: Tallapragada Phanindra , David Kelly Scott
Published: October 2016

A mathematical model that invokes the Kutta condition to account for vortex shedding from the trailing edge of a free hydrofoil in a planar ideal fluid is compared with a canonical model for the dynamics of a terrestrial vehicle subject to a nonintegrable velocity constraint. The Kutta condition is shown to be nonintegrable in a sense that parallels that in which the constraint on the terrestrial vehicle is nonintegrable. Simulations of the two systems' dynamics reinforce the analogy between the two.
Characterization of Tab-Induced Counter-Rotating Vortex Pair for Mixing Applications
Authors: Park Jeongmoon , Pagan-Vazquez Axy , Alvarado Jorge L. , Chamorro Leonardo P. , Lux Scott M. , Marsh Charles P.
Published: October 2016

An experimental and numerical investigation was carried out to explore the effects of four vortex generators (VG) on the onset of flow instabilities, the paths and characteristics of the induced coherent counter-rotating vortices at a Reynolds number Re ≈ 2000. The flow field around the VG was characterized using a smoke visualization technique and simulated numerically using Reynolds-averaged Navier-Stokes (RANS). The taper angle of the VG was varied based on the used tab geometries, including triangular, trapezoidal, and rectangular tabs, which shared the same height, inclination angle, and base width. The results reveal that each VG was able to generate a counter-rotating vortex pair (CVP), and that the taper angle has direct effects on the path of the CVP, the onset location of Kelvin–Helmholtz (K-H) instabilities, and the circulation strength of the vortex structures. Furthermore, a linear relation between VG taper angle and the onset of instability was observed experimentally. Before the onset of K–H instability, the path of the CVP in the wake of a VG can be predicted using a pseudo-viscous model, which was validated numerically and experimentally.
Riccati Transfer Matrix Method for Linear Tree Multibody Systems
Authors: Gu Junjie , Rui Xiaoting , Zhang Jianshu , Chen Gangli , Zhou Qinbo
Published: October 2016

The Riccati transfer matrix method (RTMM) improves the numerical stability of analyzing chain multibody systems with the transfer matrix method for multibody systems (MSTMM). However, for linear tree multibody systems, the recursive relations of the Riccati transfer matrices, especially those for elements with multiple input ends, have not been established yet. Thus, an RTMM formulism for general linear tree multibody systems is formulated based on the transformation of transfer equations and geometrical equations of such elements. The steady-state response under harmonic excitation of a linear tree multibody system is taken as an example and obtained by the proposed method. Comparison with the finite-element method (FEM) validates the proposed method and a numerical example demonstrates that the proposed method has a better numerical stability than the normal MSTMM.
Design of a Two Degree-of-Freedom Compliant Tool Tip for a Handheld Powered Surgical Tool
Authors: Chandrasekaran Karthik , Thondiyath Asokan
Published: October 2016

A novel monobloc design of a two degree-of-freedom (DOF) compliant tool tip for a handheld powered surgical tool is presented in this paper. The monobloc tool tip can pitch and yaw using corner-filleted flexure hinge-based compliant joints and has an integrated compliant grasper. The 2DOF of the tool tip is realized by six compliant joints placed in an alternating fashion, orthogonal to each other. The tool is externally powered and consists of a drive box, a stainless steel tube, and a compliant tool tip at the distal end. The drive box houses a thumb joystick for command input, three servo actuators, and a microcontroller. The microcontroller maps surgeon's command input to the tool tip orientation and grasper actuation. By design, the graspers of the tool tip are actuated by tensile forces conveyed by the tethers, which exert a compressive load on the 2DOF compliant joints. Since the compressive load-carrying capacity of slender flexure-based compliant joints is limited, a design to enhance the compressive load-carrying capacity of the compliant joints with a circular guide is presented. A finite-element simulation was done to verify the design of the compliant joints. Experiments were carried out to assess the relationship between the force input by the servo actuators and joint deflection. Additional experiments were carried out to determine the maximum pinching force that can be exerted by the compliant graspers. A prototype of the complete surgical tool was built to demonstrate the utility of the proposed compliant tool tip as an alternative to traditional tool tip for a handheld powered surgical tool.
Design and Evaluation of a Portable Laparoscopic Training System Using Virtual Reality
Authors: Zahiri Mohsen , Booton Ryan , Siu Ka-Chun , Nelson Carl A.
Published: October 2016

The ubiquitous nature of laparoscopic surgery and the decreased training time available for surgeons are driving an increased need for effective training systems to help surgeons learn different procedures. A cost-effective and user-friendly simulator has been designed to imitate specific training tasks for laparoscopic surgery in virtual environments via image processing and computer vision. The capability of using various actual surgical instruments suited for these specific procedures gives heightened fidelity to the simulator. Image processing via matlab software provides real-time mapping of the graspers in the workspace to the virtual reality (VR) environment (vizard software). Two different tasks (peg transfer and needle passing) were designed to evaluate trainees and compare their performance with characteristics of expert surgeons. Pilot testing of the system was carried out with 11 subjects to validate the similarity of this device with an existing surgical box trainer. Task completion time and muscle activity have been used as metrics for evaluation. The decrease in completion time for all subjects suggests similarity of skills transfer for both simulators. In addition, the p-value of muscle activity showed no significant differences for most muscles in the peg transfer task when using either the VR or physical analog environment and no significant differences for about half of the muscles in the needle passing task. Based on the results, the new proposed VR simulator appears to be a viable alternative to help trainees gain laparoscopic skills.
Deposition Thickness Modeling and Parameter Identification for a Spray-Assisted Vacuum Filtration Process in Additive Manufacturing
Authors: Mark August , Xu Yunjun , Gou Jihua
Published: October 2016

To enhance mechanical and/or electrical properties of composite materials used in additive manufacturing, nanoparticles are oftentimes deposited to form nanocomposite layers. To customize the mechanical and/or electrical properties of the final composite material, the thickness of such nanocomposite layers must be precisely controlled. A thickness model for filter cakes created through spray-assisted vacuum filtration is presented in this paper, to enable the development of advanced thickness controllers. The mass transfer dynamics in the spray atomization and vacuum filtration are studied to derive solid mass, water mass, and filter cake thickness differential area models. A two-loop nonlinear constrained optimization approach is used to identify the unknown parameters in the model. Experiments involving depositing carbon nanofibers in a sheet of filter paper are used to measure the ability of the model to mimic the filtration process.
Six-axis AFM in SEM with self-sensing and self-transduced cantilever for high speed analysis and nanolithography
Authors: Angelov Tihomir , Ahmad Ahmad , Guliyev Elshad , Reum Alexander , Atanasov Ivaylo , Ivanov Tzvetan , Ishchuk Valentyn , Kaestner Marcus , Krivoshapkina Yana , Lenk Steve , Lenk Claudia , Rangelow Ivo W. , Holz Mathias , Nikolov Nikolay
Published: October 2016

Merging two state-of-the-art surface research techniques, in particular, atomic force microscopy (AFM) and scanning electron microscopy (SEM), within a single system is providing novel capabilities like direct visual feedback and life-monitoring of tip-induced nanoscale interactions. In addition, the combination of AFM and SEM accelerates nanoscale characterization and metrology development. Here, the concept and first results of a novel AFM-integration into a high resolution scanning electron microscope and focused ion beam system for nanoscale characterization is presented. In this context, a six-axis AFM system using self-sensing thermomechanically transduced active cantilever was developed and integrated. The design of the developed AFM-integration is described and its performance is demonstrated. Results from combined examinations applying fast AFM-methods and SEM-image fusion, AFM-SEM combined metrology verification, and three dimensional-visualization are shown. Simultaneous operation of SEM and AFM provides a fast navigation combined with sub-10 nm topographic image acquisition. Metrology application scenarios of combined studies are discussed, for example of MoS2 and diverse metrological test structures.
On Zwicker tones and musical pitch in the likely absence of phase locking corresponding to the pitch
Authors: Gockel Hedwig E. , Carlyon Robert P.
Published: October 2016

It was assessed whether Zwicker tones (ZTs) (an auditory afterimage produced by a band-stop noise) have a musical pitch. First (stage I), musically trained subjects adjusted the frequency, level, and decay time of an exponentially decaying diotic sinusoid to sound similar to the ZT they perceived following the presentation of diotic broadband noise, for various band-stop positions. Next (stage II), subjects adjusted a sinusoid in frequency and level so that its pitch was a specified musical interval below that of either a preceding ZT or a preceding sinusoid, and so that it was equally loud. For each subject the reference sinusoid corresponded to their adjusted sinusoid from stage I. Subjects selected appropriate frequency ratios for ZTs, although the standard deviations of the adjustments were larger for the ZTs than for the equally salient sinusoids by a factor of 1.0–2.2. Experiments with monaural stimuli led to similar results, although the pitch of the ZTs could differ for monaural and diotic presentation of the ZT-exciting noise. The results suggest that a weak musical pitch may exist in the absence of phase locking in the auditory nerve to the frequency corresponding to the pitch (or harmonics thereof) at the time of the percept.
Numerical study of three-dimensional sound reflection from corrugated surface waves
Authors: Choo Youngmin , Song H. C. , Seong Woojae
Published: October 2016

When a sound wave propagates in a water medium bounded by a smooth surface wave, reflection from a wave crest can lead to focusing and result in rapid variation of the received waveform as the surface wave moves [Tindle, Deane, and Preisig, J. Acoust. Soc. Am. 125, 66–72 (2009)]. In prior work, propagation paths have been constrained to be in a plane parallel to the direction of corrugated surface waves, i.e., a two-dimensional (2-D) propagation problem. In this paper, the azimuthal dependence of sound propagation as a three-dimensional (3-D) problem is investigated using an efficient, time-domain Helmholtz–Kirchhoff integral formulation. When the source and receiver are in the plane orthogonal to the surface wave direction, the surface wave curvature vanishes in conventional 2-D treatments and the flat surface simply moves up and down, resulting in minimal temporal variation of the reflected signal intensity. On the other hand, the 3-D propagation analysis reveals that a focusing phenomenon occurs in the reflected signal due to the surface wave curvature formed along the orthogonal plane, i.e., out-of-plane scattering.
Surviving the flood
Authors: Gough Nancy R.
Published: October 2016

Plants use a MAPKKK-dependent pathway to control the permeability of roots to water.
Acute onset blindness: a case of optic neuritis and review of childhood optic neuritis
Authors: Ramdas Sithara , Morrison Danny , Absoud Michael , Lim Ming
Published: October 2016

Optic neuritis (ON) is an acquired disorder of the optic nerve due to inflammation, demyelination or degeneration. We report a child who presented with acute onset bilateral visual loss who, following a diagnosis of ON, was treated and had excellent visual recovery. Paediatric ON is considered to be different clinical entity to adult ON. Although in children ON is usually parainfectious or postinfectious, it can be the first presenting feature of multiple sclerosis or neuromyelitis optica spectrum disease. In this paper, we discuss the literature on treatment of ON and prediction of risk of recurrence.
Effect of day-case unilateral cochlear implantation in adults on general and disease-specific quality of life, postoperative complications and hearing results, tinnitus, vertigo and cost-effectiveness: protocol for a randomised controlled trial
Authors: Derks Laura S M , Wegner Inge , Smit Adriana L , Thomeer Hans G X M , Topsakal Vedat , Grolman Wilko
Published: October 2016

Introduction

Cochlear implantation is an increasingly common procedure in the treatment of severe to profound sensorineural hearing loss (SNHL) in children and adults. It is often performed as a day-case procedure. The major drive towards day-case surgery has been from a logistical, economical and societal perspective, but we also speculate that the patient's quality of life (QoL) is at least equal to inpatient surgery if not increased as a result of rapid discharge and rehabilitation. Even though cochlear implantation seems well suited to a day-case approach and this even seems to be common practice in some countries, evidence is scarce and of low quality to guide us towards the preferred treatment option.

Methods and analysis

A single-centre, non-blinded, randomised, controlled trial was designed to (primarily) investigate the effect on general QoL of day-case cochlear implantation compared to inpatient cochlear implantation and (secondarily) the effect of both methods on (subjective) hearing improvement, disease-specific QoL, tinnitus, vertigo and cost-effectiveness. 30 adult patients with severe to profound bilateral postlingual SNHL who are eligible for unilateral cochlear implantation will be randomly assigned to either the day-case or inpatient treatment group. The outcome measures will be assessed using auditory evaluations, questionnaires (preoperatively, at 1-week, 3-week, 3-month and 1-year follow-up) and costs diaries (weekly during the first month postoperatively, after which once in a month until 1-year follow-up). Preoperative and postoperative outcomes will be compared. The difference in costs and benefit will be represented using the incremental cost utility/effectiveness ratio. The analyses will be carried out on an intention-to-treat basis.

Ethics and dissemination

This research protocol was approved by the Institutional Review Board of the UMC Utrecht (NL45590.041.13; V.5, November 2015). The trial results will be disseminated through peer-reviewed medical journals and presented at scientific conferences.

Trial registration number

NTR4464; Pre-results.
“The constipation conundrum”: Improving recognition of constipation on a gastroenterology ward
Authors: Jackson Robert , Cheng Philip , Moreman Sarah , Davey Nicola , Owen Lisa
Published: October 2016

Constipation is a common and often overlooked problem, but it can cause serious complications for patients including pain, nausea, urinary retention, and prolonged hospital admission. There are no recognised criteria for the diagnosis of constipation in the acute hospital setting, and it is often the role of the ward doctor to identify and manage this problem.

Completion and monitoring of “stool charts” by nursing and medical staff is key to proper recognition and management of constipation. A baseline study found that while charts were completed well, they were only monitored by doctors 17.5% of the time. This quality improvement project introduced an altered “continuation sheet” to the clinical notes to prompt monitoring of stool charts and provide an area for documentation. This resulted in an increase in monitoring to 66.7%.
Red hot maples: Acer rubrum first-year phenology and growth responses to soil warming
Authors: Wheeler J.A. , Gonzalez N.M. , Stinson K.A.
Published: October 2016

Microhabitat environmental conditions are an important filter for seedling establishment, controlling the availability of optimal recruitment sites. Understanding how tree seedlings respond to warming soil temperature is critical for predicting population recruitment in the future hardwood forests of northeastern North America, particularly as environmental conditions and thus optimal microhabitat availabilities change. We examined the effect of soil warming of 5 °C during the first growing season on germination, survival, phenology, growth, and stem and root biomass allocation in Acer rubrum L. (red maple) seedlings. While there was no effect of soil warming on germination or survival, seedlings growing in warmer soils demonstrated significantly accelerated leaf expansion, delayed autumn leaf senescence, and an extended leaf production period. Further, seedlings growing in warmer soils showed larger leaf area and stem and root structures at the end of the first growing season, with no evidence of biomass allocation trade-offs. Results suggest that A. rubrum seedlings can capitalize on soil warming by adjusting leaf phenology and leaf production, resulting in a longer period of carbon uptake and leading to higher overall biomass. The absence of growth allocation trade-offs suggests that A. rubrum will respond positively to increasing soil temperatures in northeastern forests, at least in the early life stages.
Self-interacting dark matter
Authors: Mavromatos Nick E. , Argüelles Carlos R. , Ruffini Remo , Rueda Jorge A.
Published: October 2016

Self-interacting dark matter (SIDM) is a hypothetical form of dark matter (DM), characterized by relatively strong (compared to the weak interaction strength) self-interactions (SIs), which has been proposed to resolve a number of issues concerning tensions between simulations and observations at the galactic or smaller scales. We review here some recent developments discussed at the 14th Marcel Grossmann Meeting (MG14), paying particular attention to restrictions on the SIDM (total) cross-section from using novel observables in merging galactic structures, as well as the rôle of SIDM on the Milky Way halo and its central region. We report on some interesting particle-physics inspired SIDM models that were discussed at MG14, namely the glueball DM, and a right-handed neutrino DM (with mass of a few tens of keV, that may exist in minimal extensions of the standard model (SM)), interacting among themselves via vector bosons mediators in the dark sector. A detailed phenomenology of the latter model on galactic scales, as well as the potential role of the right handed neutrinos in alleviating some of the small-scale cosmology problems, namely the discrepancies between observations and numerical simulations within standard [Formula: see text]CDM and [Formula: see text]WDM cosmologies are reported.
Synthesis and Bio-Compatibility Study of Thermal-CVD Grown Graphene
Authors: Chakravarty Mayukh , Sharma Rishi , Amit Kumar , Sharma Neelima , Pradhan S. K.
Published: October 2016

Graphene based nanomaterials have attracted tremendous attention for their potential applications in various fields. In the present investigation, the growth of graphene on silicon substrate using thermal chemical vapor deposition (Thermal-CVD) method has been reported and the biocompatibility of obtained yield has been critically assessed. Raman spectra confirm the formation of graphene which was found to be the best to obtain minimal number of layers of graphene. Three prominent peaks have been observed at approximately 1360[Formula: see text]cm[Formula: see text] (D Peak), 1595[Formula: see text]cm[Formula: see text] (G Peak) and 2700[Formula: see text]cm[Formula: see text] (2D Peak). Haemolysis test and simulated body fluid (SBF) test are performed to check the biocompatibility of the synthesized graphene samples. Atomic force micrographs of the samples are taken prior and after soaking them in SBF solution to study their interaction with the fluid. Haemolysis percentage is determined using UV-Vis to determine the hemocompatible nature of the samples. The results of haemolysis and SBF test demonstrated that Thermal-CVD grown graphene samples are biocompatible.
Structural Modeling and Active Vibration Control of Smart FGM Plate through ANSYS
Authors: Bendine Kouider , Boukhoulda Benallel Farouk , Nouari Mohammed , Satla Zouaoui
Published: October 2016

This paper presents a methodology to use the software ANSYS in modeling and active vibration control of a functionally graded (FGM) plate with upper and lower surface-bonded piezoelectric layers. First a FGM plate with piezoelectric layers is designed using APDL ANSYS. Then a modal analysis has been carried out to get the first five rank frequencies and mode shapes. A proportional–integral–derivative (PID) and a linear-quadratic-based output feedback controller are introduced to realize the vibration control through a closed loop. Results for various volume fraction indexes are presented.
Is a bivariate polynomial with ± 1 coefficients irreducible? Very likely!
Authors: Bary-Soroker Lior , Kozma Gady
Published: October 2016

We prove that the probability of a random polynomial in two variables of degree [Formula: see text] and with [Formula: see text] coefficients to be irreducible tends to [Formula: see text] as [Formula: see text].
Abelian surfaces good away from 2
Authors: Rasmussen Christopher , Tamagawa Akio
Published: October 2016

Fix a number field [Formula: see text] and a rational prime [Formula: see text]. We consider abelian varieties whose [Formula: see text]-power torsion generates a pro-[Formula: see text] extension of [Formula: see text] which is unramified away from [Formula: see text]. It is a necessary, but not generally sufficient, condition that such varieties have good reduction away from [Formula: see text]. In the special case of [Formula: see text], we demonstrate that for abelian surfaces [Formula: see text], good reduction away from [Formula: see text] does suffice. The result is extended to elliptic curves and abelian surfaces over certain number fields unramified away from [Formula: see text]. An explicit example is constructed to demonstrate that good reduction away from [Formula: see text] is not sufficient, at [Formula: see text], for abelian varieties of sufficiently high dimension.
The pulse vaccination effects in mammary carcinoma
Authors: Aboura Chahinez , Touaoula Tarik Mohamed , Aribi Mourad
Published: October 2016

Induction of antitumor immunity by vaccination is one of the major current immunotherapy strategies. We present a mathematical model of the competition between immune cells and mammary carcinogenesis under the effect of Triplex vaccine. The model describes both humoral and cell-mediated immune responses against cancer cells. The control of the cancer cells growth occurs through the application of the pulse vaccination. Here we determine the relationship between the strength of the vaccine and the time required to eradicate cancer cells, and we present some simulations to illustrate our theoretical results, namely, the total cancer cells depletion, which is influenced by competition occurs among the immune and cancer cells.
Maps preserving strong 2-Jordan product on some algebras
Authors: Taghavi Ali , Kolivand Farzaneh
Published: October 2016

Let [Formula: see text] be a surjective map between some operator algebras such that [Formula: see text] for all [Formula: see text], where [Formula: see text] defined by [Formula: see text] and [Formula: see text] is Jordan product, i.e. [Formula: see text]. In this paper, we determine the concrete form of map [Formula: see text] on some operator algebras. Such operator algebras include standard operator algebras, properly infinite von Neumann algebras and nest algebras. Particularly, if [Formula: see text] is a factor von Neumann algebra that satisfies [Formula: see text] for all [Formula: see text] and idempotents [Formula: see text] then there exists nonzero scalar [Formula: see text] with [Formula: see text] such that [Formula: see text] for all [Formula: see text]
Approximation of periodic functions in certain sub-classes of Lp[0,2π]
Authors: Singh Uaday , Saini Soshal
Published: October 2016

In this paper, we determine the degree of trigonometric approximation of [Formula: see text]-periodic functions and their conjugates, in terms of the moduli of continuity associated with them, by matrix means of corresponding Fourier series. We also discuss some analogous results with remarks and corollaries.
Gorenstein homological dimensions and some duality results
Authors: Mohammadi Aghjeh Mashhad Fatemeh
Published: October 2016

Let [Formula: see text] be a local ring and [Formula: see text] denote the Matlis duality functor. Assume that [Formula: see text] possesses a normalized dualizing complex [Formula: see text] and [Formula: see text] and [Formula: see text] are two homologically bounded complexes of [Formula: see text]-modules with finitely generated homology modules. We will show that if G-dimension of [Formula: see text] and injective dimension of [Formula: see text] are finite, then [Formula: see text] Also, we prove that if Gorenstein injective dimension of [Formula: see text] and projective dimension of [Formula: see text] are finite, then [Formula: see text] These results provide some generalizations of Suzuki’s Duality Theorem and the Herzog–Zamani Duality Theorem.
Revisiting calculation of moments of number of comparisons used by the randomized quick sort algorithm
Authors: Jha Sumit Kumar
Published: October 2016

We revisit the method of Kirschenhofer, Prodinger and Tichy to calculate the moments of number of comparisons used by the randomized quick sort algorithm. We reemphasize that this approach helps in calculating these quantities with less computation. We also point out that as observed by Knuth this method also gives moments for total path length of a binary search tree built over a random set of [Formula: see text] keys.
The effect of local thermal nonequilibrium on conduction in metal foam tube heat exchanger with a uniform heat source
Authors: Biglari Mojtaba , Sakhaei Ali , Ganji Davood Domairy , Akbarzadeh Sanaz , Rezvani Abdollad
Published: October 2016

The effect of local thermal nonequilibrium on the steady state heat conduction in metal foam tube heat exchanger as a porous layer in the presence of internal heat generated by considering the thermal conductivity coefficient as a function of temperature was investigated. A two temperature model is investigated by using reconstruction of variational iteration method (RVIM). The obtained results from RVIM are compared with the numerical results of Maple. These comparisons reveal that RVIM is a very powerful and precise approach to solve nonlinear ordinary differential equations and there is a good agreement between them. In this study, the effects of porosity and internal heat generation on the temperature distribution in the solid and liquid phases are presented.
Adaptive Fuzzy Sliding Mode Control of MEMS Gyroscope with Finite Time Convergence
Authors: Ren Jianxin , Zhang Rui , Xu Bin
Published: October 2016

This paper presents adaptive fuzzy finite time sliding mode control of microelectromechanical system gyroscope with uncertainty and external disturbance. Firstly, fuzzy system is employed to approximate the uncertainty nonlinear dynamics. Secondly, nonlinear sliding mode hypersurface and double exponential reaching law are selected to design the finite time convergent sliding mode controller. Thirdly, based on Lyapunov methods, adaptive laws are presented to adjust the fuzzy weights and the system can be guaranteed to be stable. Finally, the effectiveness of the proposed method is verified with simulation.
Magnet‐Bead Based MicroRNA Delivery System to Modify CD133+ Stem Cells
Authors: Müller Paula , Voronina Natalia , Hausburg Frauke , Lux Cornelia A. , Wiekhorst Frank , Steinhoff Gustav , David Robert
Published: October 2016

Aim. CD133+ stem cells bear huge potential for regenerative medicine. However, low retention in the injured tissue and massive cell death reduce beneficial effects. In order to address these issues, we intended to develop a nonviral system for appropriate cell engineering. Materials and Methods. Modification of human CD133+ stem cells with magnetic polyplexes carrying microRNA was studied in terms of efficiency, safety, and targeting potential. Results. High microRNA uptake rates (~80–90%) were achieved without affecting CD133+ stem cell properties. Modified cells can be magnetically guided. Conclusion. We developed a safe and efficient protocol for CD133+ stem cell modification. Our work may become a basis to improve stem cell therapeutical effects as well as their monitoring with magnetic resonance imaging.
Comparison of the Electrical Properties of PERC Approach Applied to Monocrystalline and Multicrystalline Silicon Solar Cells
Authors: Wang Enyu , Wang He , Yang Hong
Published: October 2016

At present, the improvement in performance and the reduction of cost for crystalline silicon solar cells are a key for photovoltaic industry. Passivated emitter and rear cells are the most promising technology for next-generation commercial solar cells. The efficiency gains of passivated emitter and rear cells obtained on monocrystalline silicon wafer and multicrystalline silicon wafer are different. People are puzzled as to how to develop next-generation industrial cells. In this paper, both monocrystalline and multicrystalline silicon solar cells for commercial applications with passivated emitter and rear cells structure were fabricated by using cost-effective process. It was found that passivated emitter and rear cells are more effective for monocrystalline silicon solar cells than for multicrystalline silicon solar cells. This study gives some hints about the industrial-scale mass production of passivated emitter and rear cells process.
Biomaterial Strategies for Delivering Stem Cells as a Treatment for Spinal Cord Injury
Authors: Agbay Andrew , Edgar John M. , Robinson Meghan , Styan Tara , Wilson Krista , Schroll Julian , Ko Junghyuk , Khadem Mohtaram Nima , Jun Martin Byung-Guk , Willerth Stephanie M.
Published: October 2016

Ongoing clinical trials are evaluating the use of stem cells as a way to treat traumatic spinal cord injury (SCI). However, the inhibitory environment present in the injured spinal cord makes it challenging to achieve the survival of these cells along with desired differentiation into the appropriate phenotypes necessary to regain function. Transplanting stem cells along with an instructive biomaterial scaffold can increase cell survival and improve differentiation efficiency. This study reviews the literature discussing different types of instructive biomaterial scaffolds developed for transplanting stem cells into the injured spinal cord. We have chosen to focus specifically on biomaterial scaffolds that direct the differentiation of neural stem cells and pluripotent stem cells since they offer the most promise for producing the cell phenotypes that could restore function after SCI. In terms of biomaterial scaffolds, this article reviews the literature associated with using hydrogels made from natural biomaterials and electrospun scaffolds for differentiating stem cells into neural phenotypes. It then presents new data showing how these different types of scaffolds can be combined for neural tissue engineering applications and provides directions for future studies.
Changes in Waist Circumference among German Adults over Time - Compiling Results of Seven Prospective Cohort Studies
Authors: Haftenberger Marjolein , Mensink Gert B.M. , Vogt Susanne , Thorand Barbara , Peters Annette , Herzog Beatrice , Hartwig Saskia , Greiser Karin Halina , Ittermann Till , Schipf Sabine , Völzke Henry , Merz Benedikt , Nöthlings Ute , Koch Manja , Neamat-Allah Jasmine , Katzke Verena , Kaaks Rudolf , Boeing Heiner , Bachlechner Ursula , Scheidt-Nave Christa , Schienkiewitz Anja
Published: October 2016

Aim: This study aims to quantify longitudinal changes in waist circumference (WC) among adults aged 45-64 years in Germany. Methods: Data of 15,444 men and 17,207 women from one nationwide and six regional prospective German cohort studies were analyzed. The sex-specific mean change in WC per year of follow-up was assessed for each study separately. Findings from the cohort-by-cohort analysis were combined by applying meta-analytic methods. Progression to central obesity (WC ≥ 102 cm in men and ≥ 88 cm in women) within a standardized period of 10 years was described for each study. Results: The estimated mean change in WC per year of follow-up for all cohorts combined was 0.53 (95% confidence interval 0.29-0.76) cm/year for men and 0.63 (0.48-0.77) cm/year for women, but varied between the included studies. Within 10 years, about 20% of individuals with low WC (<94 cm in men; <80 cm in women) and about 50% of individuals with intermediate WC (94-102 cm in men; 80-88 cm in women) progressed to central obesity. Conclusion: The increase in mean WC with aging along with a profound increase of central adiposity is obviously and may have several adverse health effects. Obesity prevention programs should also focus on abdominal obesity.
Cellulitis in a Liver Transplant Patient as an Initial Manifestation of Disseminated Cryptococcal Disease
Authors: Gomes de Sousa Marcos Davi , Bernardes Filho Fred , Barros Costa Fernandes Luís Eduardo , Guedes Leal Cássia Regina , Rocha Magalhães Cristiane , Custódio Neto da Silva Marcos Antonio , Silva Barcaui Halime
Published: October 2016

A 50-year-old male underwent liver transplantation due to cryptogenic cirrhosis and was admitted with severe pain in the left leg as well as phlogosis. Amoxicillin/clavulanic acid was prescribed, assuming bullous erysipelas. Among the tests performed, the latex agglutination test for the Cryptococcus sp. antigen was positive, and in both the blood culture and blister culture Cryptococcus sp. was isolated. Daily fluconazole was started. Even though liposomal amphotericin B has been started on the fifth day of hospitalization, the patient progressed to death.