bluuebunny/crossref_metadata_2025 huggingface dataset:
ZVT‐PWM DC–DC boost converter with active snubber cell
Authors: Ting Naim Suleyman , Aksoy Ismail , Sahin Yakup
Published: October 2016

In this study, a novel zero voltage transition pulse width modulation (ZVT‐PWM) DC–DC boost converter with an active snubber cell is proposed. All of the semiconductor devices in the converter turn on and off with soft switching (SS). The main feature of the proposed converter is the absence of extra current or voltage stress on the main switch and main diode. There is also no extra voltage stress on the auxiliary switch and the auxiliary diodes. The main switch turns on with ZVT and turns off with zero voltage switching. The auxiliary switch turns on with zero current switching and turns off with zero current transition. The proposed converter smoothly operates under light‐load conditions. Having a simple structure at low cost is the main advantage of the proposed converter. This study also realises the theoretical analysis of the proposed converter. The experimental results, the operating stages and the key waveforms of the proposed converter, are given in detail for 500 W and 100 kHz switching frequency. Moreover, it is shown that the overall efficiency reaches a value of 97.8% at nominal output power. The proposed SS topology can be used in applications with the battery power source and low‐voltage DC‐link.
Coulomb interactions in sharp tip pulsed photo field emitters
Authors: Cook Ben , Kruit Pieter
Published: October 2016

Photofield emitters show great potential for many single electron pulsed applications. However, for the brightest pulses >1011A/(m2 sr V), our simulations show that Poisson statistics and stochastic Coulomb interactions limit the brightness and increase the energy spread even with an average of a single electron per pulse. For the systems, we study we find that the energy spread is probably the limiting factor for most applications.
Spectroscopic characterization of the ethyl radical-water complex
Authors: Lin Chen , Finney Brian A. , Laufer Allan H. , Anglada Josep M. , Francisco Joseph S.
Published: October 2016

An ab initio investigation has been employed to determine the structural and spectroscopic parameters, such as rotational constants, vibrational frequencies, vertical excitation energies, and the stability of the ethyl-water complex. The ethyl-water complex has a binding energy of 1.15 kcal⋅mol−1. The interaction takes place between the hydrogen of water and the unpaired electron of the radical. This interaction is found to produce a red shift in the OH stretching bands of water of ca. 84 cm−1, and a shift of all UV absorption bands to higher energies.
On the existence of Sobolev quasi-periodic solutions of multidimensional nonlinear beam equation
Authors: Shi Yunfeng
Published: October 2016

In this paper, we prove the existence of quasi-periodic solutions of the multidimensional nonlinear beam equation with finitely differentiable nonlinearities and quasi-periodic forcing in time.
Sufficient minimal model for DNA denaturation: Integration of harmonic scalar elasticity and bond energies
Authors: Singh Amit Raj , Granek Rony
Published: October 2016

We study DNA denaturation by integrating elasticity — as described by the Gaussian network model — with bond binding energies, distinguishing between different base pairs and stacking energies. We use exact calculation, within the model, of the Helmholtz free-energy of any partial denaturation state, which implies that the entropy of all formed “bubbles” (“loops”) is accounted for. Considering base pair bond removal single events, the bond designated for opening is chosen by minimizing the free-energy difference for the process, over all remaining base pair bonds. Despite of its great simplicity, for several known DNA sequences our results are in accord with available theoretical and experimental studies. Moreover, we report free-energy profiles along the denaturation pathway, which allow to detect stable or meta-stable partial denaturation states, composed of bubble, as local free-energy minima separated by barriers. Our approach allows to study very long DNA strands with commonly available computational power, as we demonstrate for a few random sequences in the range 200-800 base-pairs. For the latter, we also elucidate the self-averaging property of the system. Implications for the well known breathing dynamics of DNA are elucidated.
Graphene field-effect transistors with tunable sensitivity for high performance Hg (II) sensing
Authors: Li Peng , Liu Baijun , Zhang Dongzhi , Sun Yan'e , Liu Jingjing
Published: October 2016

Graphene field-effect transistors (FETs) capped with ionophore were fabricated to demonstrate the highly sensitive and selective detection of Hg (II) ions in solution. We systematically investigated the ion detection performances and sensing mechanism of this 2D material. Due to its ambipolar nature, graphene can work as either an n-type or a p-type sensor when a gate voltage is applied to switch its carrier characteristic, resulting in completely different sensing performances. The strong dependence of sensitivity on gate voltage was also investigated. Graphene FETs in optimal regimes were able to detect Hg2+ down to 0.1 ppb, one-fold lower than the World Health Organization tolerance level. Hg2+ ions can be effectively detected over a wide range of concentration (from 0.1 ppb to 1000 ppb) with graphene conductance change following the Langmuir isotherm for molecules adsorption on surface, and the time constant for ion adsorption extracted was only 3.5 s, approximately. The transfer characteristics of graphene FETs capped with mercury ionophore did not show obvious change by the existence of arsenite ions, demonstrating good selectivity. Our results illustrate the potential utility of ionophore integrated graphene FETs for monitoring heavy metal ions in solution.
Spin-dependent transport and current modulation in a current-in-plane spin-valve field-effect transistor
Authors: Kanaki Toshiki , Koyama Tomohiro , Chiba Daichi , Ohya Shinobu , Tanaka Masaaki
Published: October 2016

We propose a current-in-plane spin-valve field-effect transistor (CIP-SV-FET), which is composed of a ferromagnet/nonferromagnet/ferromagnet trilayer structure and a gate electrode. This is a promising device alternative to spin metal-oxide-semiconductor field-effect transistors. Here, we fabricate a ferromagnetic-semiconductor GaMnAs-based CIP-SV-FET and demonstrate its basic operation of the resistance modulation both by the magnetization configuration and by the gate electric field. Furthermore, we present the electric-field-assisted magnetization reversal in this device.
A new application of retarding field analyzer for the electron and ion temperature measurement on the J-TEXT tokamak
Authors: Liu Hai , Chen Zhipeng , Zhuang Ge , Chen Zhongyong , Xiao Chijin
Published: October 2016

A new application of retarding field analyzer for the electron and ion temperature measurement (named eiRFA) has been realized on the J-TEXT tokamak. A novel bias arrangement is adopted for the eiRFA to implement the simultaneous measurement of the electron and ion temperatures in the scrape-off layer, as well as the floating potential, plasma space potential, and sheath potential drop coefficient. It shows that the temperatures measured by eiRFA are reasonable and the plasma space potential obtained by two means is in good self-consistent. Moreover, the calculation of electron temperature can be modified using the eiRFA.
Correlated disorder in the Kuramoto model: Effects on phase coherence, finite-size scaling, and dynamic fluctuations
Authors: Hong Hyunsuk , O'Keeffe Kevin P. , Strogatz Steven H.
Published: October 2016

We consider a mean-field model of coupled phase oscillators with quenched disorder in the natural frequencies and coupling strengths. A fraction p of oscillators are positively coupled, attracting all others, while the remaining fraction 1−p are negatively coupled, repelling all others. The frequencies and couplings are deterministically chosen in a manner which correlates them, thereby correlating the two types of disorder in the model. We first explore the effect of this correlation on the system's phase coherence. We find that there is a critical width γc in the frequency distribution below which the system spontaneously synchronizes. Moreover, this γc is independent of p. Hence, our model and the traditional Kuramoto model (recovered when p = 1) have the same critical width γc. We next explore the critical behavior of the system by examining the finite-size scaling and the dynamic fluctuation of the traditional order parameter. We find that the model belongs to the same universality class as the Kuramoto model with deterministically (not randomly) chosen natural frequencies for the case of p < 1.
Two-dimensional dielectric collimator design and its experimental verification for microwave beam focusing
Authors: Kim H. , Park J. , Seo I. , Yoo J.
Published: October 2016

A collimator is an electromagnetic device that focuses or aligns the direction of wave propagation to achieve a narrow, intense beam. In this study, we propose a two-dimensional dielectric collimator for microwave beam focusing. This is something that is difficult to achieve using theoretical- or intuition-based approaches. We therefore used a systematic design process, which is referred to as the phase field design method, to obtain an optimal topological configuration for the collimator. The phase field parameter determines the optimal configuration of the dielectric material and, as a consequence, it determines the relative permittivity of the component. To verify the design results, we fabricated a prototype via three-dimensional printing and performed an experimental verification using an electric field scanner to measure the near field distributions of the designed collimator positioned parallel to an incident wave. We also performed angle dependent experiments for which the collimator position was offset at various angles. We confirmed that the experimental results are consistent with the simulation results.
Enhanced carrier mobility of multilayer MoS2 thin-film transistors by Al2O3 encapsulation
Authors: Kim Seong Yeoul , Park Seonyoung , Choi Woong
Published: October 2016

We report the effect of Al2O3 encapsulation on the carrier mobility and contact resistance of multilayer MoS2 thin-film transistors by statistically investigating 70 devices with SiO2 bottom-gate dielectric. After Al2O3 encapsulation by atomic layer deposition, calculation based on Y-function method indicates that the enhancement of carrier mobility from 24.3 cm2 V−1 s−1 to 41.2 cm2 V−1 s−1 occurs independently from the reduction of contact resistance from 276 kΩ·μm to 118 kΩ·μm. Furthermore, contrary to the previous literature, we observe a negligible effect of thermal annealing on contact resistance and carrier mobility during the atomic layer deposition of Al2O3. These results demonstrate that Al2O3 encapsulation is a useful method of improving the carrier mobility of multilayer MoS2 transistors, providing important implications on the application of MoS2 and other two-dimensional materials into high-performance transistors.
High quality factor platinum silicide microwave kinetic inductance detectors
Authors: Szypryt P. , Mazin B. A. , Ulbricht G. , Bumble B. , Meeker S. R. , Bockstiegel C. , Walter A. B.
Published: October 2016

We report on the development of microwave kinetic inductance detectors (MKIDs) using platinum silicide as the sensor material. MKIDs are an emerging superconducting detector technology, capable of measuring the arrival times of single photons to better than two microseconds and their energies to around ten percent. Previously, MKIDs have been fabricated using either sub-stoichiometric titanium nitride or aluminum, but TiN suffers from the spatial inhomogeneities in the superconducting critical temperature and Al has a low kinetic inductance fraction, causing low detector sensitivity. To address these issues, we have instead fabricated the PtSi microresonators with the superconducting critical temperatures of 944 ± 12 mK and high internal quality factors (Qi≳106). These devices show typical quasiparticle lifetimes of τqp≈30–40 μs and spectral resolution, R=λ/Δλ, of 8 at 406.6 nm. We compare PtSi MKIDs to those fabricated with TiN and detail the substantial advantages that PtSi MKIDs have to offer.
Thermal resistance optimization of GaN/substrate stacks considering thermal boundary resistance and temperature-dependent thermal conductivity
Authors: Park K. , Bayram C.
Published: October 2016

Here, we investigate the effects of thermal boundary resistance (TBR) and temperature-dependent thermal conductivity on the thermal resistance of GaN/substrate stacks. A combination of parameters such as substrates {diamond, silicon carbide, silicon, and sapphire}, thermal boundary resistance {10–60 m2K/GW}, heat source lengths {10 nm–20 μm}, and power dissipation levels {1–8 W} are studied by using technology computer-aided design (TCAD) software Synopsys. Among diamond, silicon carbide, silicon, and sapphire substrates, the diamond provides the lowest thermal resistance due to its superior thermal conductivity. We report that due to non-zero thermal boundary resistance and localized heating in GaN-based high electron mobility transistors, an optimum separation between the heat source and substrate exists. For high power (i.e., 8 W) heat dissipation on high thermal conductive substrates (i.e., diamond), the optimum separation between the heat source and substrate becomes submicron thick (i.e., 500 nm), which reduces the hotspot temperature as much as 50 °C compared to conventional multi-micron thick case (i.e., 4 μm). This is attributed to the thermal conductivity drop in GaN near the heat source. Improving the TBR between GaN and diamond increases temperature reduction by our further approach. Overall, we provide thermal management design guidelines for GaN-based devices.
Surface micromachining of polydimethylsiloxane for microfluidics applications
Authors: Hill Staci , Qian Weiyi , Chen Weiqiang , Fu Jianping
Published: October 2016

Polydimethylsiloxane (PDMS) elastomer has emerged as one of the most frequently applied materials in microfluidics. However, precise and large-scale surface micromachining of PDMS remains challenging, limiting applications of PDMS for microfluidic structures with high-resolution features. Herein, surface patterning of PDMS was achieved using a simple yet effective method combining direct photolithography followed by reactive-ion etching (RIE). This method incorporated a unique step of using oxygen plasma to activate PDMS surfaces to a hydrophilic state, thereby enabling improved adhesion of photoresist on top of PDMS surfaces for subsequent photolithography. RIE was applied to transfer patterns from photoresist to underlying PDMS thin films. Systematic experiments were conducted in the present work to characterize PDMS etch rate and etch selectivity of PDMS to photoresist as a function of various RIE parameters, including pressure, RF power, and gas flow rate and composition. We further compared two common RIE systems with and without bias power and employed inductively coupled plasma and capacitively coupled plasma sources, respectively, in terms of their PDMS etching performances. The RIE-based PDMS surface micromachining technique is compatible with conventional Si-based surface and bulk micromachining techniques, thus opening promising opportunities for generating hybrid microfluidic devices with novel functionalities.
Comparative performance of spectral and thermographic properties of plants and physiological traits for phenotyping salinity tolerance of wheat cultivars under simulated field conditions
Authors: Hu Yuncai , Hackl Harald , Schmidhalter Urs
Published: October 2016

Successful plant breeding in saline environments requires high-throughput phenotyping techniques to differentiate genotypes for salinity tolerance. This study employed advanced, non-destructive sensing technologies to identify traits contributing to salinity tolerance in wheat (Triticum aestivum L.). Plants were grown in large containers to simulate field conditions for control, salinity stress alone, and combined salinity and drought stress treatments. The comparative performance of spectral reflectance sensing, thermography, digital imaging, and the assessment of physiological traits of two wheat cultivars were tested at booting, anthesis and grain filling. Variation in grain yield between the two cultivars was significant for all treatments (controls, P < 0.01; others, P < 0.001), whereas there were no significant differences in straw DW regardless of treatment. Among the spectral and thermographic assessments, spectral indices were sufficiently sensitive to detect genotypic differences in salinity tolerance among the wheat cultivars after anthesis for the salinity alone and combined treatments. In contrast, physiological traits such as leaf water status and photosynthetic properties demonstrated no differences between the wheat cultivars for either the salinity alone or the combined treatments. These results suggest that spectral sensing has the potential for high-throughput screening of phenotypic traits associated with salinity tolerance of wheat cultivars.
Applying systems theory to the evaluation of a whole school approach to violence prevention
Authors: Kearney Sarah , Leung Loksee , Joyce Andrew , Ollis Debbie , Green Celia
Published: October 2016

Issue addressed

Our Watch led a complex 12‐month evaluation of a whole school approach to Respectful Relationships Education (RRE) implemented in 19 schools. RRE is an emerging field aimed at preventing gender‐based violence. This paper will illustrate how from an implementation science perspective, the evaluation was a critical element in the change process at both a school and policy level.

Methods

Using several conceptual approaches from systems science, the evaluation sought to examine how the multiple systems layers – student, teacher, school, community and government – interacted and influenced each other. A distinguishing feature of the evaluation included ‘feedback loops’; that is, evaluation data was provided to participants as it became available. Evaluation tools included a combination of standardised surveys (with pre‐ and post‐intervention data provided to schools via individualised reports), reflection tools, regular reflection interviews and summative focus groups.

Results

Data was shared during implementation with project staff, department staff and schools to support continuous improvement at these multiple systems levels. In complex settings, implementation can vary according to context; and the impact of evaluation processes, tools and findings differed across the schools. Interviews and focus groups conducted at the end of the project illustrated which of these methods were instrumental in motivating change and engaging stakeholders at both a school and departmental level and why.

Conclusion

The evaluation methods were a critical component of the pilot's approach, helping to shape implementation through data feedback loops and reflective practice for ongoing, responsive and continuous improvement. Future health promotion research on complex interventions needs to examine how the evaluation itself is influencing implementation.

So what?

The pilot has demonstrated that the evaluation, including feedback loops to inform project activity, were an asset to implementation. This has implications for other health promotion activities, where evaluation tools could be utilised to enhance, rather than simply measure, an intervention. The findings are relevant to a range of health promotion research activities because they demonstrate the importance of meta‐evaluation techniques that seek to understand how the evaluation itself was influencing implementation and outcomes.
Effects of intracerebroventricular infusions of ghrelin on secretion of follicle-stimulating hormone in peripubertal female sheep
Authors: Wójcik-Gładysz Anna , Wańkowska Marta , Gajewska Alina , Misztal Tomasz , Zielińska-Górska Marlena , Szlis Michał , Polkowska Jolanta
Published: October 2016

Reproduction depends on mechanisms responsible for the regulation of energy homeostasis and puberty is a developmental period when reproductive and somatic maturity are achieved. Ghrelin affects the activity of the hypothalamo–pituitary–gonadal axis under conditions of energy insufficiency. An in vivo model based on intracerebroventricular (i.c.v.) infusions was used to determine whether centrally administered acyl ghrelin affects transcriptional and translational activity of FSH in peripubertal lambs and whether ghrelin administration mimics the effects of short-term fasting. Standard-fed lambs received either Ringer–Lock (R-L) solution (120 µL h–1) or ghrelin (120 µL h–1, 100 µg day–1). Animals experiencing a short-term (72 h) fast were treated only with R-L solution. In each experimental group, i.c.v. infusions occurred for 3 consecutive days. Immunohistochemistry, in situ hybridisation and real-time reverse transcription quantitative polymerase chain reaction analyses revealed that short-term fasting, as well as exogenous acyl ghrelin administration to standard-fed peripubertal lambs, augmented FSHβ mRNA expression and immunoreactive FSH accumulation. In addition to the effects of ghrelin on FSH synthesis in standard-fed animals, effects on gonadotrophin release were also observed. Acyl ghrelin increased the pulse amplitude for gonadotrophin release, which resulted in an elevation in mean serum FSH concentrations. In conclusion, the present data suggest that ghrelin participates in an endocrine network that modulates gonadotrophic activity in peripubertal female sheep.
Influence of hyaluronan on endometrial receptivity and embryo attachment in sheep
Authors: Marei Waleed F. A. , Wathes D. Claire , Raheem Kabir A. , Mohey-Elsaeed Omnia , Ghafari Fataneh , Fouladi-Nashta Ali A.
Published: October 2016

An increasing number of reports suggests a role of hyaluronan (HA) in female reproduction and interest in its application in assisted reproduction is rising. However, there are contrasting data about the effectiveness of adding HA to the embryo-transfer medium on improving pregnancy rates. Using sheep as an experimental model, the studies reported here analysed the impact of HA infusion into the uterus on embryo attachment to uterine luminal epithelium (LE) and expression of selected markers of uterine receptivity. On Day 14 after natural mating (pre-attachment), uterine horns were infused with either (n = 4 each): PBS (control), HA (1 mg mL–1), HA + hyaluronidase 2 (Hyal2; 300 IU mL–1) or 4-methyl-umbelliferone (HA-synthesis inhibitor; 4MU, 1 mM). HA immunostaining on uterine sections collected on Day 17 was negative in the 4MU group and weak in the HA+Hyal2 group. In contrast to 4MU, which resulted in 100% attachment, HA infusion blocked embryo attachment in all treated animals. This was accompanied by the disappearance of mucin 1 and increased expression of osteopontin and CD44v6 in the LE of uteri with attached embryos. In conclusion, the presence of HA at the embryo–maternal interface during embryo implantation resulted in reduced endometrial receptivity and inhibited the interaction of trophoblasts with the LE, whereas clearance of HA favoured embryo attachment.
The architecture of annexation? Russia's bilateral agreements with South Ossetia and Abkhazia
Authors: Ambrosio Thomas , Lange William A.
Published: October 2016

Following the August War of 2008, Russia recognized South Ossetia and Abkhazia as independent states. Both territories remain dependent upon Moscow for their security and economic survival, and they remain dominated militarily, economically, and even politically by their northern patron. These relationships are structured, in part, by a series of bilateral agreements signed since September 2008, which have created a comprehensive legal architecture which, in turn, deeply affects the state- and nation-building processes in South Ossetia and Abkhazia. This article examines 78 agreements signed between Russia and these territories between 2008 and 2015 in order to better understand these processes and how they interact with and are influenced by their respective relationships with the Russian Federation. It groups these agreements into three categories: the 2008 “friendship” agreements which created the initial baseline for the bilateral relationship; the numerous, more narrowly defined documents which fleshed-out this relationship; and the “alliance” and “integration” agreements signed with Abkhazia and South Ossetia, respectively, through which Moscow sought to take its relations with these territories to a qualitatively new level. Of particular focus is the degree to which these territories exhibited signs of independent agency and formal autonomy, as well as the differences between them.
Who Owns the Unexpected? Insights from Antigone for Don Lamberton’s economic question
Authors: Williams Ruth F.G.
Published: October 2016

Dissent and assent contribute to new information and knowledge in that they foster ideas, avert errors and counter misplaced beliefs. Although intended to facilitate progress, innovation and creativity, dissent may be opposed by the closed mind and defensive mindset. Don Lamberton encountered a specific mindset in his own duties to scholarship in economics. Thus, the perspective of dissent is a fitting way to pay homage to his scholarship. However, this paper is also a lament. It gives an interpretation of Antigone from political philosophy which depicts Antigone rocking an ideological boat harboured by the polis. The silencing of Antigone’s voice results in unexpected losses in the oikos. This is the sort of tragedy threatening critical and innovative scholarship in the twenty-first century.
Single Cell Expression Data Reveal Human Genes that Escape X-Chromosome Inactivation
Authors: Wainer-Katsir Kerem , Linial Michal
Published: October 2016

Sex chromosomes pose an inherent genetic imbalance between genders. In mammals, one of the female’s X-chromosomes undergoes inactivation (Xi). Indirect measurements estimate that about 20% of Xi genes completely or partially escape inactivation. The identity of these escapee genes and their propensity to escape inactivation remain unsolved. A direct method for identifying escapees was applied by quantifying differential allelic expression from single cells. RNA-Seq fragments were assigned to informative SNPs which were labeled by the appropriate parental haplotype. This method was applied for measuring allelic specific expression from Chromosome-X (ChrX) and an autosomal chromosome as a control. We applied the protocol for measuring biallelic expression from ChrX to 104 primary fibroblasts. Out of 215 genes that were considered, only 13 genes (6%) were associated with biallelic expression. The sensitivity of escapees' identification was increased by combining SNP mapping for parental diploid genomes together with RNA-Seq from clonal single cells (25 lymphoblasts). Using complementary protocols, referred to as strict and relaxed, we confidently identified 25 and 31escapee genes, respectively. When pooled versions of 30 and 100 cells were used, <50% of these genes were revealed. We assessed the generality of our protocols in view of an escapee catalog compiled from indirect methods. The overlap between the escapee catalog and the genes’ list from this study is statistically significant (P-value of E-07). We conclude that single cells’ expression data are instrumental for studying X-inactivation with an improved sensitivity. Finally, our results support the emerging notion of the non-deterministic nature of genes that escape X-chromosome inactivation.
2bor not2b: Experimental evolution of functional exogenous sequences in a plant RNA virus
Authors: Willemsen Anouk , Zwart Mark P. , Ambrós Silvia , Carrasco José L. , Elena Santiago F.
Published: October 2016

Horizontal gene transfer (HGT) is pervasive in viruses, and thought to be a key mechanism in their evolution. On the other hand, strong selective constraints against increasing genome size are an impediment for HGT, rapidly purging horizontally transferred sequences and thereby potentially hindering evolutionary innovation. Here we explore experimentally the evolutionary fate of viruses with simulated HGT events, using the plant RNA virusTobacco etch virus(TEV), by separately introducing two functional, exogenous sequences to its genome. One of the events simulates the acquisition of a new function though HGT of a conserved AlkB domain, responsible for the repair of alkylation or methylation damage in many organisms. The other event simulates the acquisition of a sequence that duplicates an existing function, through HGT of the 2b RNA silencing suppressor fromCucumber mosaic virus(CMV). We then evolved these two viruses, tracked the maintenance of the horizontally transferred sequences over time, and for the final virus populations, sequenced their genome and measured viral fitness. We found that the AlkB domain was rapidly purged from the TEV genome, restoring fitness to wild-type levels. Conversely, the2bgene was stably maintained and did not have a major impact on viral fitness. Moreover, we found that2bis functional in TEV, as it provides a replicative advantage when the RNA silencing suppression domain of HC-Pro is mutated. These observations suggest a potentially interesting role for HGT of short functional sequences in ameliorating evolutionary constraints on viruses, through the duplication of functions.
The Chd1 chromatin remodeler shifts hexasomes unidirectionally
Authors: Levendosky Robert F. , Sabantsev Anton , Deindl Sebastian , Bowman Gregory D.
Published: October 2016

Despite their canonical two-fold symmetry, nucleosomes in biological contexts are often asymmetric: functionalized with post-translational modifications (PTMs), substituted with histone variants, and even lacking H2A/H2B dimers. Here we show that the Widom 601 nucleosome positioning sequence can be used to produce hexasomes in a specific orientation on DNA, which provide a useful tool for interrogating chromatin enzymes and allow for the generation of precisely defined asymmetry in nucleosomes. Using this methodology, we demonstrate that the Chd1 chromatin remodeler requires H2A/H2B on the entry side for sliding, and thus, unlike the back-and-forth sliding observed for nucleosomes, Chd1 shifts hexasomes unidirectionally. Chd1 takes part in chromatin reorganization surrounding transcribing RNA polymerase II (Pol II), and using asymmetric nucleosomes we show that ubiquitin-conjugated H2B on the entry side stimulates nucleosome sliding by Chd1. We speculate that biased nucleosome and hexasome sliding due to asymmetry contributes to the packing of arrays observed in vivo.
Synthesis of hydrogenated diamondlike carbon thin films using neon–acetylene based high power impulse magnetron sputtering discharges
Authors: Aijaz Asim , Louring Sascha , Lundin Daniel , Kubart Tomáš , Jensen Jens , Sarakinos Kostas , Helmersson Ulf
Published: October 2016

Hydrogenated diamondlike carbon (DLC:H) thin films exhibit many interesting properties that can be tailored by controlling the composition and energy of the vapor fluxes used for their synthesis. This control can be facilitated by high electron density and/or high electron temperature plasmas that allow one to effectively tune the gas and surface chemistry during film growth, as well as the degree of ionization of the film forming species. The authors have recently demonstrated by adding Ne in an Ar-C high power impulse magnetron sputtering (HiPIMS) discharge that electron temperatures can be effectively increased to substantially ionize C species [Aijaz et al., Diamond Relat. Mater. 23, 1 (2012)]. The authors also developed an Ar-C2H2 HiPIMS process in which the high electron densities provided by the HiPIMS operation mode enhance gas phase dissociation reactions enabling control of the plasma and growth chemistry [Aijaz et al., Diamond Relat. Mater. 44, 117 (2014)]. Seeking to further enhance electron temperature and thereby promote electron impact induced interactions, control plasma chemical reaction pathways, and tune the resulting film properties, in this work, the authors synthesize DLC:H thin films by admixing Ne in a HiPIMS based Ar/C2H2 discharge. The authors investigate the plasma properties and discharge characteristics by measuring electron energy distributions as well as by studying discharge current characteristics showing an electron temperature enhancement in C2H2 based discharges and the role of ionic contribution to the film growth. These discharge conditions allow for the growth of thick (>1 μm) DLC:H thin films exhibiting low compressive stresses (∼0.5 GPa), high hardness (∼25 GPa), low H content (∼11%), and density in the order of 2.2 g/cm3. The authors also show that film densification and change of mechanical properties are related to H removal by ion bombardment rather than subplantation.
A resolution of a metric singularity associated with the introduction of Λ into static spherically symmetric systems
Authors: Kiess Thomas E.
Published: October 2016

We resolve a metric singularity at large [Formula: see text] that is due to the introduction of the cosmological constant [Formula: see text] in simple static spherically symmetric systems in classical general relativity for a mass bounded within a radius [Formula: see text]. For the metric to be nonsingular, we find that ordinary matter must exist beyond [Formula: see text], and that mass densities and [Formula: see text] must have spatial ranges. These features can be developed covariantly and can ameliorate discrepancies between theoretical values of [Formula: see text] and those derived from astronomical observations. Requiring a nonsingular metric in classical general relativistic modeling of this and other physical systems has the potential to offer suggestive insights into cosmological parameters.
Gravitational collapse and dark universe with LTB geometry
Authors: Bhatti M. Zaeem-ul-Haq , Yousaf Z.
Published: October 2016

The objective of this paper is to examine the influence of polynomial [Formula: see text] dark sector cosmic terms on the collapse of electrically charged Lemaître–Tolman–Bondi geometry. We explored a class of solutions for [Formula: see text] field equations in the existence of electromagnetic field and under the constraint of constant curvature scalar. The influence of [Formula: see text] model on the dynamics of collapsing object have been discussed by studying its black hole and cosmological horizons. Also, the effects of these dark sources on the time interval between the corresponding singularities and horizons have been studied. We investigated that the process of collapse slows down due to the higher order curvature invariants of polynomial [Formula: see text] model and electromagnetic field.
Mathisson–Papapetrou–Tulczyjew–Dixon equations in ultra-relativistic regime and gravimagnetic moment
Authors: Deriglazov Alexei A. , Ramírez Walberto Guzmán
Published: October 2016

Mathisson–Papapetrou–Tulczyjew–Dixon (MPTD) equations in the Lagrangian formulation correspond to the minimal interaction of spin with gravity. Due to the interaction, in the Lagrangian equations instead of the original metric [Formula: see text] emerges spin-dependent effective metric [Formula: see text]. So we need to decide, which of them the MPTD particle sees as the spacetime metric. We show that the MPTD equations, if considered with respect to the original metric (using the standard Landau–Lifshitz spacetime decomposition), have unexpected behavior: the acceleration in the direction of the velocity grows up to infinity in the ultra-relativistic limit. If considered with respect to [Formula: see text], the theory does not have this problem. But the metric now depends on spin, so there is no unique spacetime manifold for the universe of spinning particles: each particle probes its own three-dimensional (3D) geometry. This can be improved by adding a nonminimal interaction, given the modified MPTD equations with reasonable behavior within the original metric.
Diagram Illustrations of Aggregation Operations for the Intuitionistic Fuzzy Values
Authors: Tian Feng , Liu Shousheng , Xu Zeshui , Lei Qian
Published: October 2016

Atanassov (Intuitionistic fuzzy set, Fuzzy Sets and Systems 20 (1986) 87–96) proposed the intuitionistic fuzzy set (A-IFS) that is a generalization of Zadeh's fuzzy set. The essential elements of an A-IFS are intuitionistic fuzzy values (IFVs), each of which is depicted by a membership degree and a non-membership degree. The existing literature only gives the explanation of the meaning and the aggregation operators of IFVs, which is very hard and non-visualized for us to comprehend. To overcome the above shortcomings, this paper puts forward the diagram method to analyze the structures of the basic aggregation operations of IFVs. In addition, this paper utilizes the diagram method which is similar to joint probability distribution to describe the components of aggregation operations of IFVs, and each IFV depicts a 3-dimensional vector which is regarded as the marginal distributions of the joint probability distribution.
Generalized Choquet Integral Operator of Triangular Atanassov’s Intuitionistic Fuzzy Numbers and Application to Multi-Attribute Group Decision Making
Authors: Dong Jiu-Ying , Lin Li-Lian , Wang Feng , Wan Shu-Ping
Published: October 2016

The purpose of this paper is to propose a new approach to interactive multi-attribute group decision making with triangular Atanassov's intuitionistic fuzzy numbers (TAIFNs). The contribution of this study is fivefold: (1) Minkowski distance between TAIFNs is firstly defined; (2) We define the possibility attitudinal expected values of TAIFNs and thereby present a novel risk attitudinal ranking method of TAIFNs which can sufficiently consider the risk attitude of decision maker; (3) The weighted average operator (TAIFWA) and generalized ordered weighted average (TAIFGWA) operator of TAIFNs are defined as well as the hybrid ordered weighted average (TAIFHOWA) operator; (4) To study the interaction between attributes, we further develop the generalized Choquet (TAIF-GC) integral operator and generalized hybrid Choquet (TAIF-GHC) integral operator of TAIFNs. Their desirable properties are also discussed; (5) The individual overall value of alternative is obtained by TAIF-GC operator and the collective one is derived through TAIFWA operator. Fuzzy measures of attribute subsets and expert weights are objectively derived through constructing multi-objective optimization model which is transformed into the goal programming model to solve. The system analyst selection example verifies effectiveness of the proposed approach.
Lower Bound of Vibration Modes Using the Node-Based Smoothed Finite Element Method (NS-FEM)
Authors: Liu Guirong , Chen Meng , Li Ming
Published: October 2016

The smoothed finite element method (S-FEM) has been recently developed as an effective solver for solid mechanics problems. This paper represents an effective approach to compute the lower bounds of vibration modes or eigenvalues of elasto-dynamic problems, by making use of the important softening effects of node-based S-FEM (NS-FEM). We first use NS-FEM, FEM and the analytic approach to compute the eigenvalues of transverse free vibration in strings and membranes. It is found that eigenvalues by NS-FEM are always smaller than those by FEM and the analytic method. However, NS-FEM produces spurious unphysical modes because of overly soft behavior. A technique is then proposed to remove them by analyzing their vibration shapes (eigenvectors). It is observed that spurious modes with excessively large wave numbers, which are unrelated to the physical deflection shapes but related to the discretization density, therefore can be easily removed. The final results of NS-FEM become the lower bound of eigenvalues and the accuracy can be improved via mesh refinement. And NS-FEM solutions (softer) are more reliable, because the large wave number component can be used as an indicator, which is available in FEM (stiffer), on the quality of the numerical solutions. The proposed NS-FEM procedure offers a viable and practical computational means to effectively compute the lower bounds of eigenvalues for solid mechanics problems.
R&D Collaboration Strategies for Innovation: An Empirical Study Through Social Network Analysis
Authors: Cammarano Antonello , Caputo Mauro , Lamberti Emilia , Michelino Francesca
Published: October 2016

The paper investigates the impact of network strategies on innovation strategies carried out in 2011 by 44 top R&D spending bio-pharmaceutical companies. Gathering patent and accounting data, we built the business network of joint development activities making use of social network analysis (SNA). Our findings show that each network strategy is related to different innovation strategies, confirming that social network analysis is an effective instrument for explaining why firms enter into R&D agreements with partners and the linkage of such collaborations with the overall innovation strategy.
KNOWLEDGE MANAGEMENT USING EXTERNAL KNOWLEDGE
Authors: FUJIWARA AYANO , WATANABE TOSHIYA
Published: October 2016

This study performed an empirical analysis of R&D based on technologies and knowledge embodied in people hired by advanced companies as engineers in emerging countries. In recent years, emerging companies in Asia have been recruiting numerous engineers from Japanese companies for their R&D efforts. This study empirically analysed the R&D performance of companies for which engineers from Japanese companies have become employed. Result shows that those engineers from Japanese companies contributed to increased patent production, patent complexity, and patent quality of companies in emerging Asian countries. However, the contribution is limited. Among the engineers from Japanese companies, engineers who contribute to increased patent production and who contribute to patent complexity, and patent quality are different.
Fast simulation method for airframe analysis based on big data
Authors: Liu DongLiang , Zhang LiXin
Published: October 2016

In this paper, we employ the big data method to structural analysis by considering the correlations between loads and loads, loads and results and results and results. By means of fundamental mathematics and physical rules, the principle, feasibility and error control of the method are discussed. We then establish the analysis process and procedures. The method is validated by two examples. The results show that the fast simulation method based on big data is fast and precise when it is applied to structural analysis.
Housing Affordability and Permanent Migration Intention of Rural-Urban Migrants
Authors: DONG Xin , ZHOU Weihua
Published: October 2016

Leading the rural-urban migration is the key to solving the problem of imbalanced urban structure in China; in which the migration will of the rural-urban migrants should not be ignored, especially the permanent will of migration. This paper uses the ratio of rent to income as an indicator of the housing affordability of rural-urban migrants, empirically analyzes the impact of housing affordability on the permanent migration will of rural-urban migrants. It was found that the impact of rent-income ratio is significant and there exists a turning point. Before the point, the ratio is positively correlated with the permanent migration will of rural migrants; whereas after the turning point, they are negatively correlated. Before that point, relative to income of rural migrants, the rents are still bearable and the ratio does not have a negative effect on the migration will, which explains why a large number of rural-urban migrants tend to choose the large-sized cities with higher housing prices, rather than the small and medium-sized cities or small towns with lower housing prices.
Ramsey Pricing for Cost Recovery Applied to Reservoir Infrastructure in Andalucía (Spain)
Authors: Sanchez-Martinez Teresa , Rodriguez-Ferrero Noelina
Published: October 2016

This paper proposes the Ramsey pricing methodology as a useful tool for water managers. As a case study, first we propose an alternative calculation of the annual depreciation charge for the investment in water infrastructure to that currently made by public administration, and then we apply the Ramsey contribution to the calculation of the price or regulatory tariff charged in 2009 by the Guadalquivir River Basin Authority (Andalucía, Spain) for providing water for urban supply and irrigation. According to Ramsey’s formula, its greatest effect is felt by domestic users, whose demand is relatively inelastic, compared to those whose demand is for agricultural purposes.
Toward Transoral Peripheral Lung Access: Combining Continuum Robots and Steerable Needles
Authors: Swaney Philip J. , Mahoney Arthur W. , Hartley Bryan I. , Remirez Andria A. , Lamers Erik , Feins Richard H. , Alterovitz Ron , Webster Robert J.
Published: October 2016

Lung cancer is the most deadly form of cancer in part because of the challenges associated with accessing nodules for diagnosis and therapy. Transoral access is preferred to percutaneous access since it has a lower risk of lung collapse, yet many sites are currently unreachable transorally due to limitations with current bronchoscopic instruments. Toward this end, we present a new robotic system for image-guided trans-bronchoscopic lung access. The system uses a bronchoscope to navigate in the airway and bronchial tubes to a site near the desired target, a concentric tube robot to move through the bronchial wall and aim at the target, and a bevel-tip steerable needle with magnetic tracking to maneuver through lung tissue to the target under closed-loop control. In this work, we illustrate the workflow of our system and show accurate targeting in phantom experiments. Ex vivo porcine lung experiments show that our steerable needle can be tuned to achieve appreciable curvature in lung tissue. Lastly, we present targeting results with our system using two scenarios based on patient cases. In these experiments, phantoms were created from patient-specific computed tomography information and our system was used to target the locations of suspicious nodules, illustrating the ability of our system to reach sites that are traditionally inaccessible transorally.
Comparison of Optimization Algorithms for a Tubular Aspiration Robot for Maximum Coverage in Intracerebral Hemorrhage Evacuation
Authors: Granna Josephine , Guo Yi , Weaver Kyle D. , Burgner-Kahrs Jessica
Published: October 2016

Intracerebral hemorrhage evacuation (ICH) using a tubular aspiration robot promises benefits over conventional approaches to release the pressure of an hemorrhage within the brain. The blood of the hemorrhage is evacuated through preplanned, coordinated motion of a flexible, curved, concentric tube that aspirates from within the hemorrhage. To achieve maximum decompression, the curvature of the inner aspirator tube has to be selected such that its workspace covers the hemorrhage. As the use of multiple aspiration tubes sequentially is advisable, one can perform an exhaustive search over all possible aspiration tube shapes as has been previously proposed in the literature. In this paper, we introduce a new optimization algorithm which is computationally more efficient and thus allows for quick optimization during surgery. To demonstrate its performance and compare it to the previously proposed exhaustive search algorithm, we present experimental evaluation results on 175 simulated patient trials.