bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifrequency excitation of a clamped–clamped microbeam: Analytical and experimental investigation
Authors: Jaber Nizar , Ramini Abdallah , Younis Mohammad I.
Published: March 2016

Using partial electrodes and a multifrequency electrical source, we present a large-bandwidth, large-amplitude clamped–clamped microbeam resonator excited near the higher order modes of vibration. We analytically and experimentally investigate the nonlinear dynamics of the microbeam under a two-source harmonic excitation. The first-frequency source is swept around the first three modes of vibration, whereas the second source frequency remains fixed. New additive and subtractive resonances are demonstrated. We illustrated that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled. The microbeam is fabricated using polyimide as a structural layer coated with nickel from the top and chromium and gold layers from the bottom. Using the Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device. A good agreement between the theoretical and experimental data are reported.
Magneto-optical imaging of thin magnetic films using spins in diamond
Authors: Simpson David A. , Tetienne Jean-Philippe , McCoey Julia M. , Ganesan Kumaravelu , Hall Liam T. , Petrou Steven , Scholten Robert E. , Hollenberg Lloyd C. L.
Published: March 2016

Imaging the fields of magnetic materials provides crucial insight into the physical and chemical processes surrounding magnetism and has been a key ingredient in the spectacular development of magnetic data storage. Existing approaches using the magneto-optic Kerr effect, x-ray and electron microscopy have limitations that constrain further development and there is increasing demand for imaging and characterisation of magnetic phenomena in real time with high spatial resolution. Here we show how the magneto-optical response of an array of negatively-charged nitrogen-vacancy spins in diamond can be used to image and map the sub-micron stray magnetic field patterns from thin ferromagnetic films. Using optically detected magnetic resonance, we demonstrate wide-field magnetic imaging over 100 × 100 μm2 with sub-micron spatial resolution at video frame rates, under ambient conditions. We demonstrate an all-optical spin relaxation contrast imaging approach which can image magnetic structures in the absence of an applied microwave field. Straightforward extensions promise imaging with sub-μT sensitivity and sub-optical spatial and millisecond temporal resolution. This work establishes practical diamond-based wide-field microscopy for rapid high-sensitivity characterisation and imaging of magnetic samples, with the capability for investigating magnetic phenomena such as domain wall and skyrmion dynamics and the spin Hall effect in metals.
Identification of novel RNA secondary structures within the hepatitis C virus genome reveals a cooperative involvement in genome packaging
Authors: Stewart H. , Bingham R.J. , White S. J. , Dykeman E. C. , Zothner C. , Tuplin A. K. , Stockley P. G. , Twarock R. , Harris M.
Published: March 2016

The specific packaging of the hepatitis C virus (HCV) genome is hypothesised to be driven by Core-RNA interactions. To identify the regions of the viral genome involved in this process, we used SELEX (systematic evolution of ligands by exponential enrichment) to identify RNA aptamers which bind specifically to Core in vitro. Comparison of these aptamers to multiple HCV genomes revealed the presence of a conserved terminal loop motif within short RNA stem-loop structures. We postulated that interactions of these motifs, as well as sub-motifs which were present in HCV genomes at statistically significant levels, with the Core protein may drive virion assembly. We mutated 8 of these predicted motifs within the HCV infectious molecular clone JFH-1, thereby producing a range of mutant viruses predicted to possess altered RNA secondary structures. RNA replication and viral titre were unaltered in viruses possessing only one mutated structure. However, infectivity titres were decreased in viruses possessing a higher number of mutated regions. This work thus identified multiple novel RNA motifs which appear to contribute to genome packaging. We suggest that these structures act as cooperative packaging signals to drive specific RNA encapsidation during HCV assembly.
Intraguild predation between Amblyseius swirskii and two native Chinese predatory mite species and their development on intraguild prey
Authors: Guo Yingwei , Lv Jiale , Jiang Xiaohuan , Wang Boming , Gao Yulin , Wang Endong , Xu Xuenong
Published: March 2016

Amblyseius swirskii, native to the east and southeast Mediterranean region, is a successful biological control agent of whiteflies. In this study, we investigated intraguild predations (IGP) between each stage of A. swirskii and each stage of two Phytoseiid species that occur in China, Amblyseius orientalis and Neoseiulus californicus. When there was no whitefly egg provided as the extraguild prey, IGP between A. swirskii and A. orientalis, and between A. swirskii and N. californicus, was observed in 10 and 20 out of 35 combinations, respectively. When IGP was observed, A. swirskii was the intraguild predator in 70% and 65% cases of A. orientalis and N. californicus predation, respectively. These results suggest that A. swirskii is a more aggressive intraguild predator compared to either A. orientalis or N. californicus. When whitefly eggs were provided as the extraguild prey, IGP between A. swirskii and N. californicus decreased greatly, but no significant decrease of IGP was observed between A. swirskii and A. orientalis. Amblyseius swirskii was able to complete development on both heterospecific predatory mites, and both heterospecific predatory mites completed their development on A. swirskii. Possible impacts that A. swirskii may have on local predatory mite populations in China are discussed.
Inhibition of renalase expression and signaling has antitumor activity in pancreatic cancer
Authors: Guo Xiaojia , Hollander Lindsay , MacPherson Douglas , Wang Ling , Velazquez Heino , Chang John , Safirstein Robert , Cha Charles , Gorelick Fred , Desir Gary V.
Published: March 2016

An essential feature of cancer is dysregulation of cell senescence and death. Renalase, a recently discovered secreted flavoprotein, provides cytoprotection against ischemic and toxic cellular injury by signaling through the PI3K-AKT and MAPK pathways. Here we show that renalase expression is increased in pancreatic cancer tissue and that it functions as a growth factor. In a cohort of patients with pancreatic ductal adenocarcinoma, overall survival was inversely correlated with renalase expression in the tumor mass, suggesting a pathogenic role for renalase. Inhibition of renalase signaling using siRNA or inhibitory anti-renalase antibodies decreased the viability of cultured pancreatic ductal adenocarcinoma cells. In two xenograft mouse models, either the renalase monoclonal antibody m28-RNLS or shRNA knockdown of renalase inhibited pancreatic ductal adenocarcinoma growth. Inhibition of renalase caused tumor cell apoptosis and cell cycle arrest. These results reveal a previously unrecognized role for the renalase in cancer: its expression may serve as a prognostic maker and its inhibition may provide an attractive therapeutic target in pancreatic cancer.
hnRNPK inhibits GSK3β Ser9 phosphorylation, thereby stabilizing c-FLIP and contributes to TRAIL resistance in H1299 lung adenocarcinoma cells
Authors: Gao Xuejuan , Feng Junxia , He Yujiao , Xu Fengmei , Fan Xiaoqin , Huang Wensi , Xiong Haiting , Liu Qiuyu , Liu Wanting , Liu Xiaohui , Sun Xuesong , He Qing-Yu , Zhang Qihao , Liu Langxia
Published: March 2016

c-FLIP (cellular FLICE-inhibitory protein) is the pivotal regulator of TRAIL resistance in cancer cells, It is a short-lived protein degraded through the ubiquitin/proteasome pathway. The discovery of factors and mechanisms regulating its protein stability is important for the comprehension of TRAIL resistance by tumor cells. In this study, we show that, when H1299 lung adenocarcinoma cells are treated with TRAIL, hnRNPK is translocated from nucleus to cytoplasm where it interacts and co-localizes with GSK3β. We find that hnRNPK is able to inhibit the Ser9 phosphorylation of GSK3β by PKC. This has the effect of activating GSK3β and thereby stabilizing c-FLIP protein which contributes to the resistance to TRAIL in H1299 cells. Our immunohistochemical analysis using tissue microarray provides the clinical evidence of this finding by establishing a negative correlation between the level of hnRNPK expression and the Ser9 phosphorylation of GSK3β in both lung adenocarcinoma tissues and normal tissues. Moreover, in all cancer tissues examined, hnRNPK was found in the cytoplasm whereas it is exclusively nuclear in the normal tissues. Our study sheds new insights on the molecular mechanisms governing the resistance to TRAIL in tumor cells, and provides new clues for the combinatorial chemotherapeutic interventions with TRAIL.
Effects of Systemically Administered Hydrocortisone on the Human Immunome
Authors: Olnes Matthew J. , Kotliarov Yuri , Biancotto Angélique , Cheung Foo , Chen Jinguo , Shi Rongye , Zhou Huizhi , Wang Ena , Tsang John S. , Nussenblatt Robert ,   The CHI Consortium, Dickler Howard B. , Hourigan Christopher S. , Marincola Francesco M. , McCoy J. Phillip , Perl Shira , Schum Paula , Schwartzberg Pamela L. , Trinchieri Giorgio , Valdez Janet , Young Neal S.
Published: March 2016

Corticosteroids have been used for decades to modulate inflammation therapeutically, yet there is a paucity of data on their effects in humans. We examined the changes in cellular and molecular immune system parameters, or “immunome”, in healthy humans after systemic corticosteroid administration. We used multiplexed techniques to query the immunome in 20 volunteers at baseline, and after intravenous hydrocortisone (HC) administered at moderate (250 mg) and low (50 mg) doses, to provide insight into how corticosteroids exert their effects. We performed comprehensive phenotyping of 120 lymphocyte subsets by high dimensional flow cytometry, and observed a decline in circulating specific B and T cell subsets, which reached their nadir 4–8 hours after administration of HC. However, B and T cells rebounded above baseline 24 hours after HC infusion, while NK cell numbers remained stable. Whole transcriptome profiling revealed down regulation of NF-κB signaling, apoptosis, and cell death signaling transcripts that preceded lymphocyte population changes, with activation of NK cell and glucocorticoid receptor signaling transcripts. Our study is the first to systematically characterize the effects of corticosteroids on the human immunome, and we demonstrate that HC exerts differential effects on B and T lymphocytes and natural killer cells in humans.
Bio-inspired, Moisture-Powered Hybrid Carbon Nanotube Yarn Muscles
Authors: Kim Shi Hyeong , Kwon Cheong Hoon , Park Karam , Mun Tae Jin , Lepró Xavier , Baughman Ray H. , Spinks Geoffrey M. , Kim Seon Jeong
Published: March 2016

Hygromorph artificial muscles are attractive as self-powered actuators driven by moisture from the ambient environment. Previously reported hygromorph muscles have been largely limited to bending or torsional motions or as tensile actuators with low work and energy densities. Herein, we developed a hybrid yarn artificial muscle with a unique coiled and wrinkled structure, which can be actuated by either changing relative humidity or contact with water. The muscle provides a large tensile stroke (up to 78%) and a high maximum gravimetric work capacity during contraction (2.17 kJ kg−1), which is over 50 times that of the same weight human muscle and 5.5 times higher than for the same weight spider silk, which is the previous record holder for a moisture driven muscle. We demonstrate an automatic ventilation system that is operated by the tensile actuation of the hybrid muscles caused by dew condensing on the hybrid yarn. This self-powered humidity-controlled ventilation system could be adapted to automatically control the desired relative humidity of an enclosed space.
Influence of an embedded quantum dot on the Josephson effect in the topological superconducting junction with Majorana doublets
Authors: Gong Wei-Jiang , Gao Zhen , Shan Wan-Fei , Yi Guang-Yu
Published: March 2016

One Majorana doublet can be realized at each end of the time-reversal-invariant Majorana nanowires. We investigate the Josephson effect in the Majorana-doublet-presented junction modified by different inter-doublet coupling manners. It is found that when the Majorana doublets couple indirectly via a non-magnetic quantum dot, only the normal Josephson effect occurs and the fermion parity in the system just affects the current direction and amplitude. However, one magnetic field applied on the dot can induce the fractional Josephson effect in the odd-parity case. Next if the direct and indirect couplings between the Majorana doublets coexist, no fractional Josephson effect takes place, regardless of the presence of magnetic field. Instead, there almost appears the π-period-like current in some special cases. All the results are clarified by analyzing the influence of the fermion occupation in the quantum dot on the parity conservation in the whole system. We ascertain that this work will be helpful for describing the dot-assisted Josephson effect between the Majorana doublets.
Using AAV vectors expressing the β2-adrenoceptor or associated Gα proteins to modulate skeletal muscle mass and muscle fibre size
Authors: Hagg Adam , Colgan Timothy D. , Thomson Rachel E. , Qian Hongwei , Lynch Gordon S. , Gregorevic Paul
Published: March 2016

Anabolic β2-adrenoceptor (β2-AR) agonists have been proposed as therapeutics for treating muscle wasting but concerns regarding possible off-target effects have hampered their use. We investigated whether β2-AR-mediated signalling could be modulated in skeletal muscleviagene delivery to the target tissue, thereby avoiding the risks of β2-AR agonists. In mice, intramuscular administration of a recombinant adeno-associated virus-based vector (rAAV vector) expressing the β2-AR increased muscle mass by >20% within 4 weeks. This hypertrophic response was comparable to that of 4 weeks’ treatment with the β2-AR agonist formoterol and was not ablated by mTOR inhibition. Increasing expression of inhibitory (Gαi2) and stimulatory (GαsL) G-protein subunits produced minor atrophic and hypertrophic changes in muscle mass, respectively. Furthermore, Gαi2 over-expression prevented AAV:β2-AR mediated hypertrophy. Introduction of the non-muscle Gαs isoform, GαsXL elicited hypertrophy comparable to that achieved by AAV:β2-AR. Moreover, GαsXL gene delivery was found to be capable of inducing hypertrophy in the muscles of mice lacking functional β1- and β2-ARs. These findings demonstrate that gene therapy-based interventions targeting the β2-AR pathway can promote skeletal muscle hypertrophy independent of ligand administration and highlight novel methods for potentially modulating muscle mass in settings of disease.
From Cellular Attractor Selection to Adaptive Signal Control for Traffic Networks
Authors: Tian Daxin , Zhou Jianshan , Sheng Zhengguo , Wang Yunpeng , Ma Jianming
Published: March 2016

The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains.
A single-bead telomere sensor based on fluorescence resonance energy transfer
Authors: Fan Xiao , Yue Qiaoli , Li Yanyan , Liu Yingya , Qu Lu-Lu , Cao Yingnan , Li Haitao
Published: March 2016

We present a 200 nm in-diameter single-bead sensor for the detection of single, unlabeled DNA molecules in solution using fluorescence resonance energy transfer technology.
An enzyme-responsive controlled release system based on a dual-functional peptide
Authors: Li X. , Burger S. , O'Connor A. J. , Ong L. , Karas J. A. , Gras S. L.
Published: March 2016

A new controlled release system was developed by loading a dual-functional peptide on a mesoporous silica material.
Syntheses, structural diversity and photocatalytic properties of various Co(ii) coordination polymers based on a “V”-shaped 1,3-di(4′-carboxyl-phenyl)benzene acid and different imidazole bridging ligands
Authors: Meng Xiang-min , Fan Chuan-bin , Bi Cai-feng , Zong Zi-ao , Zhang Xia , Fan Yu-hua
Published: March 2016

Various polymeric structures of complexes 1–4.
Fine-tuning of microsolvation and hydrogen bond interaction regulates substrate channelling in the course of flavonoid biosynthesis
Authors: Diharce Julien , Golebiowski Jérôme , Fiorucci Sébastien , Antonczak Serge
Published: March 2016

In the course of metabolite formation, some multienzymatic edifices, the so-called metabolon, are formed and lead through substrate channeling to a more efficient production of the natural compounds.
Microbial collagenases: challenges and prospects in production and potential applications in food and nutrition
Authors: Pal Gaurav Kumar , PV Suresh
Published: March 2016

Microbial collagenases are promising enzymes in view of their extensive industrial and biological applications.
Bismuth functionalized PVA film: field, plasmonic and pH effect on PVA originated broad photoluminescence
Authors: Kumar Brijesh , Kaur Gagandeep , Verma Rajesh Kumar , Bahadur A. , Rai S. B.
Published: March 2016

Bismuth (Bi) NPs have been synthesized by Laser Ablation Synthesis in Solution (LASiS) at different pH in different aqueous solutions [viz. H2O (H), H2O + NaOH (HN), and H2O + HCl (HC)].
Deposition, patterning, and utility of conductive materials for the rapid prototyping of chemical and bioanalytical devices
Authors: Gabardo C. M. , Soleymani L.
Published: March 2016

Rapid prototyping is a critical step in the product development cycle of miniaturized chemical and bioanalytical devices, often categorized as lab-on-a-chip devices, biosensors, and micro-total analysis systems.
Cationic aluminum hydride complexes: reactions of carbene–alane adducts with trityl-borate
Authors: Cao Levy L. , Daley Erika , Johnstone Timothy C. , Stephan Douglas W.
Published: March 2016

Reaction of (Idipp)AlH3 with [Ph3C][B(C6F5)4] in toluene affords the dimeric aluminum dication [((Idipp)AlH(μ-H))2][B(C6F5)4]2 with the corresponding reaction of (IBn)AlH3 gives [(IBn)2AlH][B(C6F5)4]2.
Electrochemical properties of a thermally expanded magnetic graphene composite with a conductive polymer
Authors: Ahmed Mahmoud M. M. , Imae Toyoko
Published: March 2016

When a magnetic graphene composite derived from FeCl3–graphite intercalation compounds was treated for 2 min at 900 °C, its capacitance increased. The deposition of polyaniline on it further increased the capacitance to be 253 F g−1 at 5 mV s−1.
An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues
Authors: Ljubić Ivan , Kivimäki Antti , Coreno Marcello
Published: March 2016

Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.
Interface engineering of hybrid perovskite solar cells with poly(3-thiophene acetic acid) under ambient conditions
Authors: Shit Arnab , Nandi Arun K.
Published: March 2016

ZnO/MAPbI3 based perovskite solar cells with poly(3-thiophene acetic acid) show higher efficiency (7.38%) and stability than P3HT based cells (5.85%) in air.
Complete ligand loss in electron ionization of the weakly bound organometallic tungsten hexacarbonyl dimer
Authors: Neustetter Michael , Mauracher Andreas , Limão-Vieira Paulo , Denifl Stephan
Published: March 2016

Electron ionization of the weakly bound tungsten hexacarbonyl dimer leads to a transformation of the weak intermolecular bond into a strong valence bond.
Electrochemical lithium-ion storage properties of quinone molecules encapsulated in single-walled carbon nanotubes
Authors: Ishii Yosuke , Tashiro Kosuke , Hosoe Kento , Al-zubaidi Ayar , Kawasaki Shinji
Published: March 2016

We investigated the electrochemical lithium-ion storage properties of 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PhQ) molecules encapsulated in the inner hollow core of single-walled carbon nanotubes (SWCNTs).
Thermally stable ultra-small Pd nanoparticles encapsulated by silica: elucidating the factors determining the inherent activity of noble metal catalysts
Authors: Ying Jiawei , Peng Honggen , Xu Xianglan , Wang Ruonan , Yu Fan , Sun Qi , Liu Wenming , Gao Zhixian , Wang Xiang
Published: March 2016

1.1 nm Pd nanoparticles embedded in silica nanospheres were prepared by an improved one-step reverse micelle method, which show superior activity and thermal stability. Pd active surface area is the determining factors for the activity.
Durability of nano-enhanced textiles through the life cycle: releases from landfilling after washing
Authors: Mitrano Denise M. , Limpiteeprakan Pawena , Babel Sandhya , Nowack Bernd
Published: March 2016

By taking a life cycle approach to study the potential for silver nanoparticle (AgNP) release from functionalized textiles, we can estimate the relative importance of different phases to the release of Ag over time.
Benzothiazole hydrazones of furylbenzamides preferentially stabilize c-MYC and c-KIT1 promoter G-quadruplex DNAs
Authors: Pany Sushree Prangya Priyadarshinee , Bommisetti Praneeth , Diveshkumar K. V. , Pradeepkumar P. I.
Published: March 2016

The stabilization of G-quadruplex DNA structures by using small molecule ligands having simple structural scaffolds has the potential to be harnessed for developing next generation anticancer agents.
Towards the molecular Borromean link with three unequal rings: double-threaded ruthenium(ii) ring-in-ring complexes
Authors: Veliks Janis , Seifert Helen M. , Frantz Derik K. , Klosterman Jeremy K. , Tseng Jui-Chang , Linden Anthony , Siegel Jay S.
Published: March 2016

Synthesis of double-threaded ruthenium(ii) ring-in-ring complexes and the Borromean link with three unequal rings detected by mass spectrometry.
Efficient and environmentally friendly Glaser coupling of terminal alkynes catalyzed by multinuclear copper complexes under base-free conditions
Authors: Zhang Ling-Juan , Wang Yan-Hong , Liu Jie , Xu Mei-Chen , Zhang Xian-Ming
Published: March 2016

An efficient catalytic system with multinuclear copper complexes as catalysts has been developed for the aerobic Glaser coupling reaction, which adopts environmentally friendly water as the solvent at room temperature under base-free condition.
Chemoenzymatic modification of silk fibroin with poly(2,6-dimethyl-1,5-phenylene ether) using horseradish peroxidase
Authors: Simmons Leo , Tsuchiya Kousuke , Numata Keiji
Published: March 2016

Hydrophobic modification of silk fibroin with poly(2,6-dimethyl-1,5-phenylene ether) (PPE) chains is achieved by the chemoenzymatic polymerization of 2,6-dimethylphenol.
Coke suppression in MTO over hierarchical SAPO-34 zeolites
Authors: Liu Xiu , Ren Shu , Zeng Gaofeng , Liu Guojuan , Wu Ping , Wang Gang , Chen Xinqing , Liu Ziyu , Sun Yuhan
Published: March 2016

Hierarchical SAPO-34 crystals were synthesized by a facile TEAOH etching post-treatment for the first time.
Hybrid green nonaqueous media: tetraethylene glycol modifies the properties of a (choline chloride + urea) deep eutectic solvent
Authors: Kadyan Anu , Behera Kamalakanta , Pandey Siddharth
Published: March 2016

In mixture of a deep eutectic solvent Reline with tetraethylene glycol, inter-species interactions are stronger than the intra-species interactions.
Structure of lipid multilayersviadrop casting of aqueous liposome dispersions
Authors: Sironi Beatrice , Snow Tim , Redeker Christian , Slastanova Anna , Bikondoa Oier , Arnold Thomas , Klein Jacob , Briscoe Wuge H.
Published: March 2016

Liposomes serve as a lipid delivery matrix and a structural precursor, facilitating solid-supported lipid multilayer formationviasimple drop casting.
Composition-controlled organometal halide perovskite via CH3NH3I pressure in a vacuum co-deposition process
Authors: Kim Beom-Soo , Choi Min-Hyung , Choi Min-Soo , Kim Jang-Joo
Published: March 2016

We report an efficient method to adjust the compositions of CH3NH3PbI3 perovskite by controlling the working pressure of CH3NH3I and its effects on perovskite films in a vacuum co-deposition process.
Phase formation and conductivity degradation of Sr1−xKxSiO3−0.5x ionic conductors
Authors: Xu Jungu , Liu Shuaibo , Wang Quanchao , Xiaofeng Junshu , Li Xiaohui , Kuang Xiaojun
Published: March 2016

Amorphous K2Si2O5 is responsible for the high ionic (not oxide ions) conductivity in Sr1−xKxSiO3−0.5x materials.
Linguistic Masking Release in School-Age Children and Adults
Authors: Calandruccio Lauren , Leibold Lori J. , Buss Emily
Published: March 2016

Purpose

This study assessed if 6- to 8-year-old children benefit from a language mismatch between target and masker speech for sentence recognition in a 2-talker masker.

Method

English sentence recognition was evaluated for English monolingual children (ages 6–8 years,
n
= 15) and adults (
n
= 15) in an English 2-talker and a Spanish 2-talker masker. A regression analysis with subject as a random variable was used to test the fixed effect of listener group and masker language and the interaction of these two effects.

Results

Thresholds were approximately 5 dB higher for children than for adults in both maskers. However, children and adults benefited to the same degree from a mismatch between the target and masker language with approximately 3 dB lower thresholds in the Spanish than the English masker.

Conclusions

Results suggest that children are able to take advantage of linguistic differences between English and Spanish speech maskers to the same degree as adults. Yet, overall worse performance for children may indicate general cognitive immaturity compared with adults, perhaps causing children to be less efficient when combining glimpses of degraded speech information into a meaningful sentence.
Improving breakdown performance for novel LDMOS using n+ floating islands in substrate
Authors: Chen Yinhui , Hu Sheng Dong , Cheng Kun , Jiang Yuyu , Zhou Jianlin , Tang Fang , Zhou Xi Chuan , Gan Ping
Published: March 2016

A novel lateral double‐diffusion MOS (LDMOS) with n+ floating islands in the substrate (NFI LDMOS) is proposed. In the NFI LDMOS, a series of n+ floating islands are introduced into the substrate. On the condition of a high‐voltage blocking state, n+ floating islands induce the high potential from the drain region to the source region, which modulates the drift region's electric field and leads to a higher breakdown voltage (BV). What is more, the specific on‐resistance (Ron,sp) is reduced by the higher doping concentration of the drift region due to the n+ floating islands. Compared with the conventional LDMOS at the same 40 μm drift region, the BV of the NFI LDMOS is enhanced by 74.6% and Ron,sp is reduced by 19.7%. So, the proposed NFI LDMOS possesses a higher figure‐of‐merit (FOM).
Design of a low‐voltage op‐amp‐less ASDM to linearise VCO‐ADC
Authors: Babaie‐Fishani A. , Rombouts P.
Published: March 2016

A very simple asynchronous sigma delta modulator design for linearisation of VCO ADC's is presented. The circuit only consists of a passive feedback filter and a Schmitt Trigger. By proper sizing, the non‐linearity error can be reduced to well below 0.12% for input signals that go almost rail‐to‐rail. The design has been manufactured in the low power version of TSMC 65 nm technology and was measured at a 1 V power supply.
Enabling active and healthy ageing decision support systems with the smart collection of TV usage patterns
Authors: Billis Antonis S. , Batziakas Asterios , Bratsas Charalampos , Tsatali Marianna S. , Karagianni Maria , Bamidis Panagiotis D.
Published: March 2016

Smart monitoring of seniors behavioural patterns and more specifically activities of daily living have attracted immense research interest in recent years. Development of smart decision support systems to support the promotion of health smart homes has also emerged taking advantage of the plethora of smart, inexpensive and unobtrusive monitoring sensors, devices and software tools. To this end, a smart monitoring system has been used in order to extract meaningful information about television (TV) usage patterns and subsequently associate them with clinical findings of experts. The smart TV operating state remote monitoring system was installed in four elderly women homes and gathered data for more than 11 months. Results suggest that TV daily usage (time the TV is turned on) can predict mental health change. Conclusively, the authors suggest that collection of smart device usage patterns could strengthen the inference capabilities of existing health DSSs applied in uncontrolled settings such as real senior homes.
Predicting asthma exacerbations employing remotely monitored adherence
Authors: Killane Isabelle , Sulaiman Imran , MacHale Elaine , Breathnach Aoife , Taylor Terence E. , Holmes Martin S. , Reilly Richard B. , Costello Richard W.
Published: March 2016

This Letter investigated the efficacy of a decision‐support system, designed for respiratory medicine, at predicting asthma exacerbations in a multi‐site longitudinal randomised control trial. Adherence to inhaler medication was acquired over 3 months from patients with asthma employing a dose counter and a remote monitoring adherence device which recorded participant's inhaler use: n = 184 (23,656 audio files), 61% women, age (mean ± sd) 49.3 ± 16.4. Data on occurrence of exacerbations was collected at three clinical visits, 1 month apart. The relative risk of an asthma exacerbation for those with good and poor adherence was examined employing a univariate and multivariate modified Poisson regression approach; adjusting for age, gender and body mass index. For all months dose counter adherence was significantly (p < 0.01) higher than remote monitoring adherence. Overall, those with poor adherence had a 1.38 ± 0.34 and 1.42 ± 0.39 (remotely monitored) and 1.25 ± 0.32 and 1.18 ± 0.31 (dose counter) higher relative risk of an exacerbation in model 1 and model 2, respectively. However, this was not found to be statistically significantly different. Remotely monitored adherence holds important clinical information and future research should focus on refining adherence and exacerbation measures. Decision‐support systems based on remote monitoring may enhance patient–physician communication, possibly reducing preventable adverse events.
Performance analysis of amplify‐and‐forward cognitive relay networks with interference power constraints over Nakagami‐m fading channels
Authors: Shurman Mohammad M. , Al‐Mistarihi Mamoun F. , Alhulayil Moawiah M.
Published: March 2016

With the wide‐spread wireless applications and services, the spectrum scarcity has become a challenging problem. Thus, it is necessary to find a solution to have more spectrum bands. One from these solutions is the cognitive relay network, where we can increase the spectrum utilization by combining the cognitive radio (CR) with cooperative spectrum sharing systems. In this paper, the performance of cognitive relay networks under interference power constraints from the primary user (PU) is studied. Here, the system models are studied by utilizing different scenarios. The first scenario is by using a single amplify‐and‐forward (AF) relay, and the second one is by using a single AF relay with selection diversity. Tabulated expressions for the outage probability (OP) are derived over independent and non‐identically distributed Nakagami‐m fading channels. Numerical results show that the cooperative spectrum sharing transmission with a single AF relay and selection diversity outperforms both the direct transmission and the transmission using a single AF relay for the underlay cognitive relay networks. Furthermore, the results show that the outage performance depends on the minimum fading severity parameters of the two hops of the secondary user (SU) and the OP decreases as the PU moves away from the SU network.
Reducing codebook loss with reconfigurable receive antennas
Authors: Afsheen Uzma , Smith Peter J. , Martin Philippa A.
Published: March 2016

In this study, a reconfigurable antenna codebook feedback (FB) scheme is investigated to reduce precoding codebook loss without increasing the number of FB bits. Analysis and simulations show that increasing the number of receive antenna states (S) has the same effect as codebook size expansion when the codeword and state selection is based on minimising the distance between channel and codeword. In addition, the authors propose an optimum selection approach. The signal to noise ratio (SNR) and rates achieved with perfect FB in a traditional non‐reconfigurable antenna system, can be exceeded with only S = 2, using the proposed optimum selection. In fact doubling S gives an approximate SNR gain of 40% compared with S = 1. The authors also consider the effects of channel estimation errors and correlated antenna states. The authors show that the performance losses due to correlation can be quantified with a simple closed form result.
Simplified QR‐decomposition based and lattice reduction‐assisted multi‐user multiple‐input–multiple‐output precoding scheme
Authors: Fang Shu , Wu Jian , Lu Chengyi , Yue Zong‐di , Han Yuan‐chao
Published: March 2016

Future wireless communication systems require more and more antennas at the transceiver to improve the achievable rates. Multi‐user multiple‐input multiple‐output (MU‐MIMO) technique is regarded as a potential technique to serve large number of users simultaneously to further increase the achievable rates in MIMO systems. If the number of antennas at the transceiver is large, the computational complexity of precoding becomes the bottleneck and a big challenge in MU‐MIMO system. In this paper, a simplified QR decomposition with lattice reduction assisted MU‐MIMO precoding scheme named S‐QR‐LR is proposed as a low‐complexity MU‐MIMO transmission scheme. The simplified QR decomposition method is delicately designed and operated twice for the proposed precoding scheme not only to achieve good performance but also reduce the computational complexity significantly. The proposed S‐QR‐LR scheme first uses the simplified QR decomposition operation to balance the multi‐user interference and the noise. Then, the proposed S‐QR‐LR precoding scheme utilizes the simplified QR decomposition method again with the assist of lattice reduction to obtain the precoding gain to further improve the performance with low computational complexity. Analytical and simulation results show that the proposed S‐QR‐LR precoding scheme achieves best performance among the existing precoding schemes, but requires the lowest computational complexity.
Efficient optimal deadlock control of flexible manufacturing systems
Authors: Han Libin , Xing Keyi , Zhou Mengchu , Chen Xiao , Gao Zhenxin
Published: March 2016

The development of an efficient deadlock avoidance policy (DAP) is a critical step in the design and operation of a flexible manufacturing system (FMS). However, even for a simple FMS, the computation of an optimal DAP is intractable. This work addresses the optimal deadlock control problem of FMSs. Based on their Petri net models, it introduces the concept of κ‐resources and proves that an FMS containing no κ‐resources has only two types of reachable states: safe ones and deadlocks. It then can obtain an optimal DAP with polynomial computational complexity for a broader class of FMSs, which was never seen before. At the same time, for these FMSs, new structurally simpler optimal Petri net controllers are proposed.
Power corrected bridgeless converter based switched mode power supply factor
Authors: Singh Shikha , Singh Bhim , Bhuvaneswari Gurumoorthy , Bist Vashist
Published: March 2016

In this study, a new switched mode power supply (SMPS) for personal computers (PCs) with improved power quality and enhanced output voltage regulation is designed, modelled and implemented in the hardware. The normally used diode converter at the front end of any SMPS is eliminated in the present configuration by making use of two non‐isolated power factor corrected (PFC) converters at the front end in a back to back manner. This is followed by an isolated dc–dc converter which yields multiple dc voltages required in the PCs. The front end converter is designed in discontinuous conduction mode with a single control loop to achieve both voltage control and PFC. A fair comparison between the conventional SMPS and the proposed SMPS is made to demonstrate the effectiveness of the proposed configuration which is verified by simulation results and corroborated with experimental results.
Input‐series‐output‐parallel connected modular high frequency isolated AC–AC converters with positive compensation of inner‐current loop
Authors: Xu Guo , Sha Deshang , Liao Xiaozhong
Published: March 2016

A control strategy for input‐series‐output‐parallel (ISOP) connected modular high frequency isolated AC–AC converter is proposed in this study. The circulating currents among all the constituent modules are avoided by the proposed pulse width modulation sequence generation method. Based on the revealed relationship between input voltage sharing (IVS) and output current sharing (OCS), a stable control strategy is proposed by using an output voltage loop and positive inner‐current compensation loops. The individual input voltage sharing loops are eliminated. With the proposed control strategy, OCS or IVS can be achieved well for ISOP modular AC–AC converters under both steady and dynamic state, even in the case when the parameters of individual modules are mismatched. Simulation and experimental results are presented to verify the effectiveness of the control strategy.
A note on supervised classification and Nash-equilibrium problems
Authors: Couellan Nicolas
Published: March 2016

In this note, we investigate connections between supervised classification and (Generalized) Nash equilibrium problems (NEP & GNEP). For the specific case of support vector machines (SVM), we exploit the geometric properties of class separation in the dual space to formulate a non-cooperative game. NEP and Generalized NEP formulations are proposed for both binary and multi-class SVM problems.
Synchrotron spectroscopy of confined carriers in CdF2-CaF2 superlattices
Authors: Ivanovskikh K. V. , Hughes-Currie R. B. , Reid M. F. , Wells J.-P. R. , Sokolov N. S. , Reeves R. J.
Published: March 2016

Luminescence spectroscopic and temporal dynamic properties of high energy elementary excitations in CdF2-CaF2 superlattices have been studied utilising excitation with vacuum ultraviolet and X-ray synchrotron radiation while comparing the results with those obtained for CdF2 and CaF2 bulk crystals. It is shown that the optical properties of the superlattice structures are determined by exciton emission in the CdF2 monolayers. The experimental manifestations of exciton confinement phenomena are discussed.
Ghost fringe removal techniques using Lissajous data presentation
Authors: Erskine David J. , Eggert J. H. , Celliers P. M. , Hicks D. G.
Published: March 2016

A VISAR (Velocity Interferometer System for Any Reflector) is a Doppler velocity interferometer which is an important optical diagnostic in shockwave experiments at the national laboratories, used to measure equation of state (EOS) of materials under extreme conditions. Unwanted reflection of laser light from target windows can produce an additional component to the VISAR fringe record that can distort and obscure the true velocity signal. Accurately removing this so-called ghost artifact component is essential for achieving high accuracy EOS measurements, especially when the true light signal is only weakly reflected from the shock front. Independent of the choice of algorithm for processing the raw data into a complex fringe signal, we have found it beneficial to plot this signal as a Lissajous and seek the proper center of this path, even under time varying intensity which can shift the perceived center. The ghost contribution is then solved by a simple translation in the complex plane that recenters the Lissajous path. For continuous velocity histories, we find that plotting the fringe magnitude vs nonfringing intensity and optimizing linearity is an invaluable tool for determining accurate ghost offsets. For discontinuous velocity histories, we have developed graphically inspired methods which relate the results of two VISARs having different velocity per fringe proportionalities or assumptions of constant fringe magnitude to find the ghost offset. The technique can also remove window reflection artifacts in generic interferometers, such as in the metrology of surfaces.
Optical characteristics of p-type GaAs-based semiconductors towards applications in photoemission infrared detectors
Authors: Lao Y. F. , Perera A. G. U. , Wang H. L. , Zhao J. H. , Jin Y. J. , Zhang D. H.
Published: March 2016

Free-carrier effects in a p-type semiconductor including the intra-valence-band and inter-valence-band optical transitions are primarily responsible for its optical characteristics in infrared. Attention has been paid to the inter-valence-band transitions for the development of internal photoemission (IPE) mid-wave infrared (MWIR) photodetectors. The hole transition from the heavy-hole (HH) band to the spin-orbit split-off (SO) band has demonstrated potential applications for 3–5 μm detection without the need of cooling. However, the forbidden SO-HH transition at the Γ point (corresponding to a transition energy Δ0, which is the split-off gap between the HH and SO bands) creates a sharp drop around 3.6 μm in the spectral response of p-type GaAs/AlGaAs detectors. Here, we report a study on the optical characteristics of p-type GaAs-based semiconductors, including compressively strained InGaAs and GaAsSb, and a dilute magnetic semiconductor, GaMnAs. A model-independent fitting algorithm was used to derive the dielectric function from experimental reflection and transmission spectra. Results show that distinct absorption dip at Δ0 is observable in p-type InGaAs and GaAsSb, while GaMnAs displays enhanced absorption without degradation around Δ0. This implies the promise of using GaMnAs to develop MWIR IPE detectors. Discussions on the optical characteristics correlating with the valence-band structure and free-hole effects are presented.
On-chip Josephson junction microwave switch
Authors: Naaman O. , Abutaleb M. O. , Kirby C. , Rennie M.
Published: March 2016

The authors report on the design and measurement of a reflective single-pole single-throw microwave switch with no internal power dissipation, based on a superconducting circuit containing a single Josephson junction. The data demonstrate the switch operation with 2 GHz instantaneous bandwidth centered at 10 GHz, low insertion loss, and better than 20 dB on/off ratio. The switch's measured performance agrees well with simulations for input powers up to −100 dBm. An extension of the demonstrated circuit to implement a single-pole double-throw switch is shown in simulation.
Narrow-band near-field nanoscopy in the spectral range from 1.3 to 8.5 THz
Authors: Kuschewski F. , von Ribbeck H.-G. , Döring J. , Winnerl S. , Eng L. M. , Kehr S. C.
Published: March 2016

Nano-spectroscopy in the terahertz frequency range remains challenging despite recent technological progress in developing both THz emitter sources and near-field optical microscopy (SNOM). Here, we combine scattering-type SNOM with a free-electron laser light source, to tune into the 1.3–8.5 THz range. A significant portion of this range, namely, the frequencies above ∼3 THz, is not covered by previously reported near-field microscopy systems. However, it constitutes an indispensable regime where many elementary processes in solids including collective lattice excitations, charge, and spin transport occur. Our approach of nano-spectroscopy and nano-imaging provides a versatile analysis of nanostructures as small as 50 nm, hence beating the optical diffraction limit by λ/4600.
Lamb waves dispersion curves for diamond based piezoelectric layered structure
Authors: Sorokin B. P. , Kvashnin G. M. , Telichko A. V. , Novoselov A. S. , Burkov S. I.
Published: March 2016

The presence of spurious peaks in the amplitude-frequency response of diamond based piezoelectric layered structure was shown. Excitation of such peaks results in deterioration of an useful acoustical signal. It was shown that such spurious peaks should be associated with Lamb waves in a layered structure. By means of FEM analysis, the propagation of acoustic waves of different types in the piezoelectric layered structure “Al/AlN/Mo/(100) diamond” has been investigated in detail. By analyzing the elastic displacement patterns at frequencies from 0 up to 250 MHz, a set of all the possible acoustic waves, especially Lamb modes, have been studied, and dispersive curves of phase velocity have been plotted. A revised classification of Lamb modes has been introduced.
Magneto-elastic coupling in La(Fe, Mn, Si)13Hy within the Bean-Rodbell model
Authors: Bez Henrique N. , Nielsen Kaspar K. , Norby Poul , Smith Anders , Bahl Christian R. H.
Published: March 2016

First order magnetic phase transition materials present a large magnetocaloric effect around the transition temperature, where these materials usually undergo a large volume or structural change. This may lead to some challenges for applications, as the material may break apart during field change, due to high internal stresses. A promising magnetocaloric material is La(Fe, Mn, Si)13Hy, where the transition temperature can be controlled through the Mn amount. In this work we use XRD measurements to evaluate the temperature dependence of the unit cell volume with a varying Mn amount. The system is modelled using the Bean-Rodbell model, which is based on the assumption that the spin-lattice coupling depends linearly on the unit cell volume. This coupling is defined by the model parameter η, where for η > 1 the material undergoes a first order transition and for η  ≤ 1 a second order transition. We superimpose a Gaussian distribution of the transition temperature with a standard deviation σT0, in order to model the chemical inhomogeneity. Good agreement is obtained between measurements and model with values of η  ∼ 1.8 and σ(T0) = 1.0 K.
Stimulated quantum phase slips from weak electromagnetic radiations in superconducting nanowires
Authors: Jafari-Salim Amir , Eftekharian Amin , Majedi A. Hamed , Ansari Mohammad H.
Published: March 2016

We study the rate of quantum phase slips in an ultranarrow superconducting nanowire exposed to weak electromagnetic radiations. The superconductor is in the dirty limit close to the superconducting-insulating transition, where fluxoids move in strong dissipation. We use a semiclassical approach and show that external radiation stimulates a significant enhancement in the probability of quantum phase slips.