bluuebunny/crossref_metadata_2025 huggingface dataset:
Taylor dispersion and thermal expansion effects on flame propagation in a narrow channel
Authors: Pearce P. , Daou J.
Published: July 2014

We investigate the propagation of a premixed flame subject to thermal expansion through a narrow channel against a Poiseuille flow of large amplitude. This is the first study to consider the effect of a large-amplitude flow, characterised by a Péclet number of order one, $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{Pe}=O(1)$, on a variable-density premixed flame in the asymptotic limit of a narrow channel. It is also the first study on Taylor dispersion in the context of combustion. The relationship between the propagation speed and Péclet number is investigated, with the effect of large flame-front thickness $\epsilon $ and activation energy $\beta $ studied asymptotically in an appropriate distinguished limit. The premixed flame for $\epsilon \to \infty $, with $\mathit{Pe}=O(1)$, is found to be governed by the equation for a planar premixed flame with an effective diffusion coefficient. In this case the premixed flame can be considered to be in the Taylor regime of enhanced dispersion due to a parallel flow. The infinite activation energy limit $\beta \to \infty $ is taken to provide an analytical description of the propagation speed. Corresponding results are obtained for a premixed flame in the constant-density approximation. The asymptotic results are compared to numerical results obtained for selected values of $\epsilon $ and $\beta $ and for moderately large values of the Péclet number. Physical reasons for the differences in propagation speed between constant- and variable-density flames are discussed. Finally, the asymptotic results are shown to agree with those of previous studies performed in the limit $\mathit{Pe}\to 0$.
Immune responses during cutaneous and visceral leishmaniasis
Authors: KEDZIERSKI LUKASZ , EVANS KRYSTAL J.
Published: July 2014

Leishmaniaare protozoan parasites spread by a sandfly insect vector and causing a spectrum of diseases collectively known as leishmaniasis. The disease is a significant health problem in many parts of the world, resulting in an estimated 1·3 million new cases and 30 000 deaths annually. Current treatment is based on chemotherapy, which is difficult to administer, expensive and becoming ineffective in several endemic regions. To date there is no vaccine against leishmaniasis, although extensive evidence from studies in animal models indicates that solid protection can be achieved upon immunization. This review focuses on immune responses toLeishmaniain both cutaneous and visceral forms of the disease, pointing to the complexity of the immune response and to a range of evasive mechanisms utilized by the parasite to bypass those responses. The amalgam of innate and acquired immunity combined with the paucity of data on the human immune response is one of the major problems currently hampering vaccine development and implementation.
Antidepressants strongly influence the relationship between depression and heart rate variability: findings from The Irish Longitudinal Study on Ageing (TILDA)
Authors: O'Regan C. , Kenny R. A. , Cronin H. , Finucane C. , Kearney P. M.
Published: July 2014

Background

Heart rate variability (HRV) is known to be reduced in depression; however, is unclear whether this is a consequence of the disorder or due to antidepressant medication.

Methods

We analysed data on 4750 participants from the first wave of The Irish Longitudinal Study on Ageing (TILDA). Time [standard deviation of normal to normal intervals (SDNN ms2)] and frequency domain [low frequency (LF) and high frequency (HF)] measures of HRV were derived from 3-lead surface electrocardiogram records obtained during 10 min of supine rest. Depression was assessed using the Center for Epidemiologic Studies – Depression scale.

Results

Participants on antidepressants [with (n = 80) or without depression (n = 185)] differed significantly from controls (not depressed and not taking antidepressants n = 4107) on all measures of HRV. Depressed participants not taking antidepressants (n = 317) did not differ from controls on any measures of HRV. In linear regression analysis adjusted for relevant factors all antidepressants were associated with lower measures HRV. Participants on selective serotonin reuptake inhibitors (SSRIs) had higher measures of HRV relative to participants on tricyclic antidepressants or serotonin–norepinephrine reuptake inhibitors respectively.

Conclusions

Our results suggest that reductions in HRV observed among depressed older adults are driven by the effects of antidepressant medications. SSRIs have less impact on HRV than other antidepressants but they are still associated with lower measures of HRV. Study limitations include the use of a self-report measure of depression and floor effects of age on HRV could have limited our ability to detect an association between HRV and depression.
Joint dynamic analysis of space manipulator with planetary gear train transmission
Authors: Yang Tianfu , Yan Shaoze , Ma Wei , Han Zengyao
Published: July 2014

Joints of space manipulators are usually simplified as torsional springs in modeling motion equations, and the nonlinear behaviors of the reducer in the joints are generally neglected. In this study, a dynamic model of a space manipulator that considers the joints that are transmitted through a typical 2K-H planetary gear reducer is developed using the Lagrangian method. The backlash clearances, gear tooth profile error, and time-variant meshing stiffness are integrated into the process. The simulation results show that the backlash clearances lead to the accumulation of positioning errors in the space manipulator when the joints rotate back and forth. The tooth profile error is the main cause of severe acceleration fluctuations and meshing force impacts. These fluctuations influence torque instability, which may accelerate gear system failure.
Losing a language in childhood: a longitudinal case study on language attrition
Authors: FLORES CRISTINA
Published: July 2014

This paper is based upon a longitudinal study of L2 attrition in a bilingual child who grew up in an L2 migration background (Germany) and moved to the country of origin (Portugal) at the age of nine, experiencing adominance shift from theL2 totheL1. The study aims to analyze the effects of language loss in L2 German. Data collection started 3 weeks after the child's immersion in the Portuguese setting and ended 18 months later. Results show first effects of language attrition after 5 months of reduced exposure to German; 18 months later the informant showed severe word retrieval difficulties and was unable to produce complete sentences in her L2. The findings thus confirm the conclusions of other studies on child language attrition, which attest to strong effects of attrition when the loss of contact with the target language occurs in childhood.
A minimal generating set of the level 2 mapping class group of a non-orientable surface
Authors: HIROSE SUSUMU , SATO MASATOSHI
Published: July 2014

We construct a minimal generating set of the level 2 mapping class group of a nonorientable surface of genus g, and determine its abelianization for g ≥ 4.
The impact of restaurant consumption among US adults: effects on energy and nutrient intakes
Authors: Nguyen Binh T , Powell Lisa M
Published: July 2014

Objective

To examine the effect of fast-food and full-service restaurant consumption on adults’ energy intake and dietary indicators.

Design

Individual-level fixed-effects regression model estimation based on two different days of dietary intake data was used.

Setting

Parallel to the rising obesity epidemic in the USA, there has been a marked upward trend in total energy intake derived from food away from home.

Subjects

The full sample included 12 528 respondents aged 20–64 years who completed 24 h dietary recall interviews for both day 1 and day 2 in the National Health and Nutrition Examination Survey (NHANES) 2003–2004, 2005–2006, 2007–2008 and 2009–2010.

Results

Fast-food and full-service restaurant consumption, respectively, was associated with an increase in daily total energy intake of 813·75 kJ (194·49 kcal) and 858·04 kJ (205·21 kcal) and with higher intakes of saturated fat (3·48 g and 2·52 g) and Na (296·38 mg and 451·06 mg). Individual characteristics moderated the impacts of restaurant food consumption with adverse impacts on net energy intake being larger for black adults compared with their white and Hispanic counterparts and greater for middle-income v. high-income adults.

Conclusions

Adults’ fast-food and full-service restaurant consumption was associated with higher daily total energy intake and poorer dietary indicators.
Televised obesity-prevention advertising across US media markets: exposure and content, 2010–2011
Authors: Kornfield Rachel , Szczypka Glen , Powell Lisa M , Emery Sherry L
Published: July 2014

Objective

To examine levels of exposure and content characteristics for recent televised obesity-prevention campaigns sponsored by state and community health departments, federal agencies, non-profit organizations and television stations in the USA.

Design

Nielsen television ratings for obesity-prevention advertising were collected for the top seventy-five US media markets and were used to calculate household exposure levels for 2010 and 2011. Governmental advertisements were coded for content.

Setting

United States.

Results

Average household exposure to obesity-prevention campaigns was 2·6 advertisements per month. Exposure increased by 31 % between 2010 and 2011, largely driven by increases in federal advertisements. In 2011, the federal government accounted for 62 % of obesity-prevention exposure, non-profit organizations for 9 %, community departments for 8 %, state departments for 3 %, and television station-sponsored public-service announcements for 17 %. The greatest percentage increase between 2010 and 2011 was in community advertising, reflecting efforts funded by the Communities Putting Prevention to Work (CPPW) programme. Among thirty-four state and community campaigns, the majority advocated both healthy eating and physical activity (53 %). Campaigns typically had positive or neutral emotional valence (94 %). Obesity or overweight was mentioned in 47 % of campaigns, but only 9 % specifically advocated weight loss.

Conclusions

Exposure to televised obesity-prevention advertising increased from 2010 to 2011 and was higher than previously found in 1999–2003, apart from in 2003 during the federal VERB campaign. Nevertheless, exposure remains low relative to advertising for unhealthy foods. New federal campaigns have increased exposure to obesity-prevention advertising nationally, while CPPW grants have increased exposure for targeted areas.
Pial Arteries Respond Earlier than Penetrating Arterioles to Neural Activation in the Somatosensory Cortex in Awake Mice Exposed to Chronic Hypoxia: An Additional Mechanism to Proximal Integration Signaling?
Authors: Sekiguchi Yuta , Takuwa Hiroyuki , Kawaguchi Hiroshi , Kikuchi Takahiro , Okada Eiji , Kanno Iwao , Ito Hiroshi , Tomita Yutaka , Itoh Yoshiaki , Suzuki Norihiro , Sudo Ryo , Tanishita Kazuo , Masamoto Kazuto
Published: July 2014

The pial and penetrating arteries have a crucial role in regulating cerebral blood flow (CBF) to meet neural demand in the cortex. Here, we examined the longitudinal effects of chronic hypoxia on the arterial diameter responses to single whisker stimulation in the awake mouse cortex, where activity-induced responses of CBF were gradually attenuated. The vasodilation responses to whisker stimulation under prehypoxia normal conditions were 8.1% and 12% relative to their baselines in the pial arteries and penetrating arterioles, respectively. After 3 weeks of hypoxia, however, these responses were significantly reduced to 5.5% and 4.1%, respectively. The CBF response, measured using laser-Doppler flowmetry (LDF), induced by the same whisker stimulation was also attenuated (14% to 2.6%). A close linear correlation was found for the responses between the penetrating arteriolar diameter and LDF, and their temporal dynamics. After 3 weeks of chronic hypoxia, the initiation of vasodilation in the penetrating arterioles was significantly extended, but the pial artery responses remained unchanged. These results show that vasodilation of the penetrating arterioles followed the pial artery responses, which are not explainable in terms of proximal integration signaling. The findings therefore indicate an additional mechanism for triggering pial artery dilation in the neurovascular coupling.
Clinical Translation in the Virtual Liver Network
Authors: Kuepfer L , Kerb R , Henney AM
Published: July 2014

The liver is the central detoxifying organ, continuously removing xenobiotics from the vascular system. Given its role in drug metabolism, a functional understanding of liver physiology is crucial to optimizing drug efficacy and patient safety. The Virtual Liver Network (VLN), a German national flagship research program, focuses on producing validated computer models of human liver physiology. These models are used to analyze patient‐derived data and thereby gain mechanistic insights in the processes underlying drug pharmacokinetics (PK).

CPT Pharmacometrics Syst. Pharmacol. (2014) 3, e127; doi:10.1038/psp.2014.25; published online 30 July 2014
Nanopipette delivery: influence of surface charge
Authors: Shi Wenqing , Sa Niya , Thakar Rahul , Baker Lane A.
Published: July 2014

In this report, transport through a nanopipette is studied and the interplay between current rectification and ion delivery for small pipettes is examined.
Desalting protein ions in native mass spectrometry using supercharging reagents
Authors: Cassou Catherine A. , Williams Evan R.
Published: July 2014

Low concentrations of supercharging reagents m-NBA (1.5%) and sulfolane (2.5%) effectively desalt protein ions produced by electrospray ionization from aqueous solutions, improving mass measuring accuracy for large proteins.
Size tunable synthesis of solution processable diamond nanocrystals
Authors: Mandal Manik , Haso Fadi , Liu Tianbo , Fei Yingwei , Landskron Kai
Published: July 2014

Size tunable synthesis of solution processable diamond nanocrystals is reported.
Alkyne mechanochemistry: putative activation by transoidal bending
Authors: Diesendruck Charles E. , Zhu Lingyang , Moore Jeffrey S.
Published: July 2014

Mechanochemical transoidal bending of triple bonds lead to an unexpected reaction between alkynes and azide traps.
A lithiomethyl trimethylammonium reagent as a methylene donor
Authors: den Hartog Tim , Sarria Toro Juan M. , Couzijn Erik P. A. , Chen Peter
Published: July 2014

A soluble analogue of Wittig's lithiomethyl trimethylammonium reagent has been prepared, studied, and used as efficient methylene donor.
Designing two-photon fluorescent probes based on the target-induced enhancement of the absorption cross-section
Authors: Zeng Lingyu , Chen Shiyu , Xia Tian , Zhong Cheng , Liu Zhihong
Published: July 2014

We have reported a new strategy for two-photon probe design for the simultaneous target-induced enhancement of the two-photon absorption cross-section and quantum yield.
Tuning of net architectures of Ni(ii) and Zn(ii) coordination polymers using isomeric organic linkers
Authors: Liu Shuang-De , Kuo Bing-Chiuan , Liu Yen-Wen , Lee Jing-Yi , Wong Kwun Yip , Lee Hon Man
Published: July 2014

Ni(ii) and Zn(ii) coordination polymers with diverse net topologies were synthesized using isomeric organic linkers.
Crystal lattice effect on the quenching of the intracluster magnetic interaction in [V12B18O60H6]10−polyoxometalate
Authors: Hermosilla-Ibáñez Patricio , Cañon-Mancisidor Walter , Costamagna Juan , Vega Andrés , Paredes-García Verónica , Garland Maria Teresa , Le Fur Eric , Cador Olivier , Spodine Evgenia , Venegas-Yazigi Diego
Published: July 2014

Quenching effect of the intracluster antiferromagnetic coupling by alkaline ions of the crystalline packing.
Green tea polyphenol–reduced graphene oxide: derivatisation, reduction efficiency, reduction mechanism and cytotoxicity
Authors: Abdullah M. F. , Zakaria R. , Zein S. H. S.
Published: July 2014

This paper reports on the derivatisation, reduction efficiency, reduction mechanism and cytotoxicity of green tea polyphenol–reduced graphene oxide (GTP–RGO).
Synthesis of glycopolymers at various pendant spacer lengths of glucose moiety and their effects on adhesion, viability and proliferation of osteoblast cells
Authors: Trinadh Mummuluri , Kannan Govindaraj , Rajasekhar Tota , Sesha Sainath Annadanam V. , Dhayal Marshal
Published: July 2014

Glycopolymers with three different pendant alkyl chain lengths (0, 4 and 6) of conjugated glucose moieties were prepared by deacetylation of synthesized acetylated polymers and theirin vitroresponses with osteoblast cell adhesion, viability and proliferation were investigated. The increase in pendant spacer length of glucose moiety of the glycopolymer had enhanced cytocompatibility even at higher glycopolymer concentration.
A convenient eco-friendly system for the synthesis of 5-sulfenyl tetrazole derivatives of indoles and pyrroles employing CeCl3·7H2O in PEG-400
Authors: Fortes Margiani P. , Bassaco Mariana M. , Kaufman Teodoro S. , Silveira Claudio C.
Published: July 2014

The use of CeCl3·7H2O in PEG-400 for the convenient synthesis of 5-sulfenyl tetrazoles derived from indoles and pyrroles, is reported. The scope and limitations of the transformation were also studied.
Perspectives and advances of microalgal biodiesel production with supercritical fluid technology
Authors: Zeng Dan , Li Ruosong , Yan Ting , Fang Tao
Published: July 2014

Biodiesel, a sustainable and clean energy source, has been greatly attracting interest to compete against serious challenges like energy crisis and environmental pollution.
Visible light-driven decomposition of gaseous benzene on robust Sn2+-doped anatase TiO2 nanoparticles
Authors: Zhuang Huaqiang , Gu Quan , Long Jinlin , Lin Huan , Lin Huaxiang , Wang Xuxu
Published: July 2014

The Sn2+-doped TiO2 nanoparticles are excellent and promising visible-light photocatalysts for the decomposition of benzene with robust photostability.
A hexanuclear Cu(i) cluster supported by cuprophilic interaction: effects of aromatics on luminescence properties
Authors: Chakraborty Anindita , Ramachandran Krishna Kumar , Yamijala Sharma S. R. K. C. , Pati Swapan K. , Maji Tapas Kumar
Published: July 2014

A highly luminescent hexanuclear Cu(i) cluster was synthesized using a tricarboxylate linker. The flexibility in the linker renders Cu(i)–Cu(i) interactions that results in unique cluster centred emission properties.
Nanobubble formation on a warmer substrate
Authors: Xu Chenglong , Peng Shuhua , Qiao Greg G. , Gutowski Voytek , Lohse Detlef , Zhang Xuehua
Published: July 2014

The solvent exchange procedure is an often-used protocol to produce surface nanobubbles.
Development of a biocompatible and biodegradable hybrid hydrogel platform for sustained release of ionic drugs
Authors: Wu Jun , Zhao Xin , Wu Dequn , Chu Chih-Chang
Published: July 2014

We have developed and characterized a new hydrogel platform for ionic drug delivery, incorporating cationic, anionic, and temperature responsive precursors. In vitro biological assays show that these polymers have excellent biocompatibility, controllable biodegradability, and sustained ionic drug release capability.
Fingerprinting of hydroxyl radical-attacked polysaccharides byN-isopropyl-2-aminoacridone labelling
Authors: Vreeburg Robert A. M. , Airianah Othman B. , Fry Stephen C.
Published: July 2014

Hydroxyl radicals (•OH) cause non-enzymic scission of polysaccharides in diverse biological systems. Such reactions can be detrimental (e.g. causing rheumatic and arthritic diseases in mammals) or beneficial (e.g. promoting the softening of ripening fruit, and biomass saccharification). Here we present a method for documenting •OH action, based on fluorescent labelling of the oxo groups that are introduced as glycosulose residues when •OH attacks polysaccharides. The method was tested on several polysaccharides, especially pectin, after treatment with Fenton reagents. 2-Aminoacridone plus cyanoborohydride reductively aminated the oxo groups in treated polysaccharides; the product was then reacted with acetone plus cyanoborohydride, forming a stable tertiary amine with the carbohydrate linked to N-isopropyl-2-aminoacridone (pAMAC). Digestion of labelled pectin with ‘Driselase’ yielded several fluorescent products which on electrophoresis and HPLC provided a useful ‘fingerprint’ indicating •OH attack. The most diagnostic product was a disaccharide conjugate of the type pAMAC·UA-GalA (UA=unspecified uronic acid), whose UA-GalA bond was Driselase-resistant (product 2A). 2A was clearly distinguishable from GalA-GalA–pAMAC (disaccharide labelled at its reducing end), which was digestible to GalA–pAMAC. The methodology is applicable, with appropriate enzymes in place of Driselase, for detecting natural and artificial •OH attack in diverse plant, animal and microbial polysaccharides.
Particle filter with spline resampling and global transition model
Authors: Choe Gwangmin , Wang Tianjiang , Liu Fang , Hyon Suchol , Ha Jongwon
Published: July 2014

The authors introduce the concept of a spline resampling in the particle filter to deal with high accuracy and sample impoverishment. The resampling is usually based on a linear transformation on the weights of the particles, so it affects the filtering accuracy. The spline resampling consists of two parts: the spline transformation of weights and the spread transformation of states. The former is based on a spline transformation on the weights of the particles to obtain highly accurate particle filtering, and the latter is based on a point spread transformation on states of particles to prevent sample impoverishment due to a decline in the diversity of hypothesis after resampling. Two transformations are sequentially implemented to incorporate with each other. Then, the authors propose a global transition model in the particle filter, which takes account of the background variation caused by the camera motion, to decrease error from real object position. The authors test the performance of their spline resampling and the global transition model in the particle filter in an object‐tracking scenario. Experimental results demonstrate that the particle filter with the spline resampling and the global transition model has promising discriminative capability in comparison with others.
Segmentation of vehicle detector data for improved k‐nearest neighbours‐based traffic flow prediction
Authors: Bernaś Marcin , Płaczek Bartłomiej , Porwik Piotr , Pamuła Teresa
Published: July 2014

This study presents a data segmentation method, which was intended to improve the performance of the k‐nearest neighbours algorithm for making short‐term traffic volume predictions. According to the introduced method, selected segments of vehicle detector data are searched for records similar to the current traffic conditions, instead of the entire database. The data segments are determined on the basis of a segmentation procedure, which aims to select input data that are useful for the prediction algorithm. Advantages of the proposed method were demonstrated in experiments on real‐world traffic data. Experimental results show that the proposed method not only improves the accuracy of the traffic volume prediction, but also significantly reduces its computational cost.
Stochastic effects of traffic randomness on the determination of signal change and clearance intervals at signalised intersections
Authors: Wang Fen , Tang Keshuang , Li Keping
Published: July 2014

Conventional methods of intergreen time design are based on deterministic traffic flow theory and are difficult to fully reflect traffic randomness especially driver's decision differences. This study is to develop a probabilistic model to extensively investigate the effects of traffic flow randomness and driver's decision errors on the determination of intergreen times. An analytical framework was proposed based on a safety reliability model earlier developed by the authors and validated based on field data at a typical high‐speed intersection in Shanghai. Then, comprehensive sensitivity analysis was performed to look into the fluctuation of safety reliability towards critical variables as well as their variations and correlations. Two logistic regression models were developed to quantify the effects of each random component on the probabilities of risky behaviour and clearance failure, that is, safety reliability indicators for intergreen intervals. To facilitate easy applications of the proposed approach, a set of scenario analysis were done to calculate the required intergreen intervals under different traffic conditions and safety reliability levels. Application tables were finally provided for signal design, which are able to recommend more sophisticated intergreen times and thus aid the practitioners to select proper intergreen times according to local conditions without complicated calculation.
Fabrication of size‐tunable hierarchical CrN nanohole arrays for two‐dimensional nanomould using modified nanosphere lithography
Authors: Wu Hung‐Chun , Bao MingDong , Ma Kung‐Jeng
Published: July 2014

This Letter presents a low‐cost, high‐throughput strategy for fabricating size‐tunable hierarchical CrN nanohole arrays for a nanomould using a magnetron sputtering approach with nanosphere lithography (NIL)‐based technology. The size of the polystyrene nanospheres has a direct inﬂuence on the diameter and period of the CrN nanohole structure. The reactive ion etching and magnetron sputtering process can easily control the nanohole size and depth. The hole depth generally depends on the ﬁlm thickness. The contact angles were measured by the sessile drop method using distilled water, ethylene glycol and diiodomethane. The surface‐free energy of the CrN nanomould was calculated using the Owens–Wendt geometric mean approach. This Letter reports the successful fabrication of a series of nanoholes with diameters decreased from 347 ± 9.6 to approximately 166 ± 11.8 nm with a depth of 100 ± 5.6 nm. The corresponding surface‐free energy decreased from 40.83 to approximately 24.58 mN/m. The diameter of nanoholes has an obvious effect on the surface‐free energy and there is tendency for the surface‐free energy to decrease with the decrease in the diameter of the nanoholes. This new approach of ordered CrN nanohole array structures can be used to create a two‐dimensional nanomould for NIL.
Application of acrylic‐based nanocomposites in the consolidation of historical enamel layers
Authors: Podgórski Andrzej , Tomaszewska‐Szewczyk Alina , Piasecka Arletta
Published: July 2014

Enamel is a special coating obtained from the mixture of powdered minerals, fluxes and various pigments. This coating is used on metal to protect it against corrosion. Enamel offers properties superior to those of traditional materials, including good chemical resistance, increased thermal and colour stability. Positive features of enamels have been noted by artists, which resulted in the development of various decorative techniques. These embellishments were characterised by the highest level of artistry. However, enamel is also a very brittle material; mechanical strain or rough handling may cause cracking or exfoliation. To control these effects, the damaged structure of historic enamel is filled with an agent which stabilises it against breaking stress, whether between the coating and the metal or in the enamelling layer itself. Presented are the results of research on the consolidation of enamel by means of nanocomposites. The polymer matrix applied was acrylic resin (Paraloid). The filler was Aerosil 200 fumed silica modified by 3‐methacryloxypropyltrimethoxysilane. Selected properties of the polymer/filler composition were measured, including adhesion, hardness and flexibility. It was observed how the addition of a modified filler to acrylic resin changed its properties. Relative to the initial properties of the resin, the differences in the adhesion between the composite and glass (enamel imitation) or the composite and metal indicate interactions between the composite and the metal or glass substrate.
Flexible and elastic metamaterial absorber for low frequency, based on small-size unit cell
Authors: Yoo Y. J. , Zheng H. Y. , Kim Y. J. , Rhee J. Y. , Kang J.-H. , Kim K. W. , Cheong H. , Kim Y. H. , Lee Y. P.
Published: July 2014

Using a planar and flexible metamaterial (MM), we obtained the low-frequency perfect absorption even with very small unit-cell size in snake-shape structure. These shrunken, deep-sub-wavelength and thin MM absorbers were numerically and experimentally investigated by increasing the inductance. The periodicity/thickness (the figure of merit for perfect absorption) is achieved to be 10 and 2 for single-snake-bar and 5-snake-bar structures, respectively. The ratio between periodicity and resonance wavelength (in mm) is close to 1/12 and 1/30 at 2 GHz and 400 MHz, respectively. The absorbers are specially designed for absorption peaks around 2 GHz and 400 MHz, which can be used for depressing the electromagnetic noise from everyday electronic devices and mobile phones.
A genetic algorithm for first principles global structure optimization of supported nano structures
Authors: Vilhelmsen Lasse B. , Hammer Bjørk
Published: July 2014

We present a newly developed publicly available genetic algorithm (GA) for global structure optimisation within atomic scale modeling. The GA is focused on optimizations using first principles calculations, but it works equally well with empirical potentials. The implementation is described and benchmarked through a detailed statistical analysis employing averages across many independent runs of the GA. This analysis focuses on the practical use of GA’s with a description of optimal parameters to use. New results for the adsorption of M8 clusters (M = Ru, Rh, Pd, Ag, Pt, Au) on the stoichiometric rutile TiO2(110) surface are presented showing the power of automated structure prediction and highlighting the diversity of metal cluster geometries at the atomic scale.
Design of the high-resolution soft X-ray imaging system on the Joint Texas Experimental Tokamak
Authors: Li Jianchao , Ding Yonghua , Zhang Xiaoqing , Xiao Zhengyu , Zhuang Ge
Published: July 2014

A new soft X-ray diagnostic system has been designed on the Joint Texas Experimental Tokamak (J-TEXT) aiming to observe and survey the magnetohydrodynamic (MHD) activities. The system consists of five cameras located at the same toroidal position. Each camera has 16 photodiode elements. Three imaging cameras view the internal plasma region (r/a < 0.7) with a spatial resolution about 2 cm. By tomographic method, heat transport outside from the 1/1 mode X-point during the sawtooth collapse is found. The other two cameras with a higher spatial resolution 1 cm are designed for monitoring local MHD activities respectively in plasma core and boundary.
Methodological demonstration of laser beam pointing control for space gravitational wave detection missions
Authors: Dong Yu-Hui , Liu He-Shan , Luo Zi-Ren , Li Yu-Qiong , Jin Gang
Published: July 2014

In space laser interferometer gravitational wave (G.W.) detection missions, the stability of the laser beam pointing direction has to be kept at 10 nrad/√Hz. Otherwise, the beam pointing jitter noise will dominate the noise budget and make the detection of G.W. impossible. Disturbed by the residue non-conservative forces, the fluctuation of the laser beam pointing direction could be a few μrad/√Hz at frequencies from 0.1 mHz to 10 Hz. Therefore, the laser beam pointing control system is an essential requirement for those space G.W. detection missions. An on-ground test of such beam pointing control system is performed, where the Differential Wave-front Sensing technique is used to sense the beams pointing jitter. An active controlled steering mirror is employed to adjust the beam pointing direction to compensate the jitter. The experimental result shows that the pointing control system can be used for very large dynamic range up to 5 μrad. At the interested frequencies of space G.W. detection missions, between 1 mHz and 1 Hz, beam pointing stability of 6 nrad/√Hz is achieved.
Spectral investigations of photoionized plasmas induced in atomic and molecular gases using nanosecond extreme ultraviolet (EUV) pulses
Authors: Bartnik A. , Fiedorowicz H. , Wachulak P.
Published: July 2014

In this paper, results of spectral investigations of low temperature photoionized plasmas, created by irradiation of gases with intense pulses of extreme ultraviolet (EUV) radiation from a laser-produced plasma (LPP) source, are presented. The LPP source was based on a double-stream KrXe/He gas-puff target irradiated with 4 ns/0.8 J/10 Hz Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region λ ≈ 10–12 nm; however, spectrally integrated intensity at longer wavelengths was also significant. The EUV beam was focused on a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Irradiation of gases resulted in formation of photoionized plasmas emitting radiation in the EUV range. Radiation spectra, measured for plasmas produced in various gases, are dominated by emission lines, originating from single charged ions. Significant differences in spectral intensities and distributions between plasmas created in neon and molecular gases were observed.
Correlation between surface phonon mode and luminescence in nanocrystalline CdS thin films: An effect of ion beam irradiation
Authors: Kumar Pragati , Saxena Nupur , Gupta Vinay , Singh Fouran , Agarwal Avinash
Published: July 2014

The influence of swift heavy ion irradiation (SHII) on surface phonon mode (SPM) and green emission in nanocrystalline CdS thin films grown by chemical bath deposition is studied. The SHII of nanocrystalline CdS thin films is carried out using 70 MeV Ni ions. The micro Raman analysis shows that asymmetry and broadening in fundamental longitudinal optical (LO) phonon mode increases systematically with increasing ion fluence. To analyze the role of phonon confinement, spatial correlation model (SCM) is fitted to the experimental data. The observed deviation of SCM to the experimental data is further investigated by fitting the micro Raman spectra using two Lorentzian line shapes. It is found that two Lorentzian functions (LFs) provide better fitting than SCM fitting and facilitate to identify the contribution of SPM in the observed distortion of LO mode. The behavior of SPM as a function of ion fluence is studied to correlate the observed asymmetry (Γa/Γb) and full width at half maximum of LO phonon mode and to understand the SHII induced enhancement of SPM. The ion beam induced interstitial and surface state defects in thin films, as observed by photoluminescence (PL) spectroscopy studies, may be the underlying reason for enhancement in SPM. PL studies also show enhancement in green luminescence with increase in ion fluence. PL analysis reveals that the variation in population density of surface state defects after SHII is similar to that of SPM. The correlation between SPM and luminescence and their dependence on ion irradiation fluence is explained with the help of thermal spike model.
GaAsSb/GaAsN short-period superlattices as a capping layer for improved InAs quantum dot-based optoelectronics
Authors: Utrilla A. D. , Reyes D. F. , Ulloa J. M. , González D. , Ben T. , Guzman A. , Hierro A.
Published: July 2014

The application of a GaAsSb/GaAsN short-period superlattice capping layer (CL) on InAs/GaAs quantum dots (QDs) is shown to be an option for providing improved luminescence properties to this system. Separating both GaAsSb and GaAsN ternaries during the growth in 2 monolayer-thick phases solves the GaAsSbN immiscibility-related problems. Strong fluctuations in the CL composition and strain field as well as in the QD size distribution are significantly reduced, and a more regular CL interface is also obtained. Room-temperature (RT) photoluminescence (PL) is obtained for overall N contents as high as 3%, yielding PL peak wavelengths beyond 1.4 μm in samples with a type-II band alignment. High external quantum efficiency electroluminescence and photocurrent from the QD ground state are also demonstrated at RT in a single QD-layer p-i-n device. Thus, it becomes possible to combine and transfer the complementary benefits of Sb- and N-containing GaAs alloys to InAs QD-based optoelectronics.
Plasma asymmetry due to the magnetic filter in fusion-type negative ion sources: Comparisons between two and three-dimensional particle-in-cell simulations
Authors: Fubiani G. , Boeuf J. P.
Published: July 2014

Previously reported 2D Particle-In-Cell Monte Carlo Collisions (PIC-MCC) simulations of negative ion sources under conditions similar to those of the ITER neutral beam injection system have shown that the presence of the magnetic filter tends to generate asymmetry in the plasma properties in the extraction region. In this paper, we show that these conclusions are confirmed by 3D PIC-MCC simulations and we provide quantitative comparisons between the 2D and 3D model predictions.
Resolving three-dimensional shape of sub-50 nm wide lines with nanometer-scale sensitivity using conventional optical microscopes
Authors: Attota Ravikiran , Dixson Ronald G.
Published: July 2014

We experimentally demonstrate that the three-dimensional (3-D) shape variations of nanometer-scale objects can be resolved and measured with sub-nanometer scale sensitivity using conventional optical microscopes by analyzing 4-D optical data using the through-focus scanning optical microscopy (TSOM) method. These initial results show that TSOM-determined cross-sectional (3-D) shape differences of 30 nm–40 nm wide lines agree well with critical-dimension atomic force microscope measurements. The TSOM method showed a linewidth uncertainty of 1.22 nm (k = 2). Complex optical simulations are not needed for analysis using the TSOM method, making the process simple, economical, fast, and ideally suited for high volume nanomanufacturing process monitoring.
Intense femtosecond photoexcitation of bulk and monolayer MoS2
Authors: Paradisanos I. , Kymakis E. , Fotakis C. , Kioseoglou G. , Stratakis E.
Published: July 2014

The effect of femtosecond laser irradiation on bulk and single-layer MoS2 on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A1g and E2g1 vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800 nm and 1030 nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed.
Electrocoalescence based serial dilution of microfluidic droplets
Authors: Bhattacharjee Biddut , Vanapalli Siva A.
Published: July 2014

Dilution of microfluidic droplets where the concentration of a reagent is incrementally varied is a key operation in drop-based biological analysis. Here, we present an electrocoalescence based dilution scheme for droplets based on merging between moving and parked drops. We study the effects of fluidic and electrical parameters on the dilution process. Highly consistent coalescence and fine resolution in dilution factor are achieved with an AC signal as low as 10 V even though the electrodes are separated from the fluidic channel by insulator. We find that the amount of material exchange between the droplets per coalescence event is high for low capillary number. We also observe different types of coalescence depending on the flow and electrical parameters and discuss their influence on the rate of dilution. Overall, we find the key parameter governing the rate of dilution is the duration of coalescence between the moving and parked drop. The proposed design is simple incorporating the channel electrodes in the same layer as that of the fluidic channels. Our approach allows on-demand and controlled dilution of droplets and is simple enough to be useful for assays that require serial dilutions. The approach can also be useful for applications where there is a need to replace or wash fluid from stored drops.
Extraordinary acoustic transmission mediated by Helmholtz resonators
Authors: Koju Vijay , Rowe Ebony , Robertson William M.
Published: July 2014

We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.
Effects of Radial Direction and Eccentricity on Acceleration Perception
Authors: Mueller Alexandra S , Timney Brian
Published: July 2014

Radial optic flow can elicit impressions of self-motion—vection—or of objects moving relative to the observer, but there is disagreement as to whether humans have greater sensitivity to expanding or to contracting optic flow. Although most studies agree there is an anisotropy in sensitivity to radial optic flow, it is unclear whether this asymmetry is a function of eccentricity. The issue is further complicated by the fact that few studies have examined how acceleration sensitivity is affected, even though observers and objects in the environment seldom move at a constant speed. To address these issues, we investigated the effects of direction and eccentricity on the ability to detect acceleration in radial optic flow. Our results indicate that observers are better at detecting acceleration when viewing contraction compared with expansion and that eccentricity has no effect on the ability to detect accelerating radial optic flow. Ecological interpretations are discussed.
How blebs and pseudopods cooperate during chemotaxis
Authors: Tyson Richard A. , Zatulovskiy Evgeny , Kay Robert R. , Bretschneider Till
Published: July 2014

Significance

We show that blebs—pressure-driven extensions of the plasma membrane—preferentially form in concave regions of the plasma membrane of migrating
Dictyostelium
cells and propose that the underlying physical reason is due to membrane tension, which provides an outward force at concavities. Blebs can transform into pseudopods by continued actin polymerization and pseudopods can trigger blebs on their flanks. Thus the two forms of protrusion can cooperate during chemotaxis.
Origin of myofibroblasts in the fibrotic liver in mice
Authors: Iwaisako Keiko , Jiang Chunyan , Zhang Mingjun , Cong Min , Moore-Morris Thomas Joseph , Park Tae Jun , Liu Xiao , Xu Jun , Wang Ping , Paik Yong-Han , Meng Fanli , Asagiri Masataka , Murray Lynne A. , Hofmann Alan F. , Iida Takashi , Glass Christopher K. , Brenner David A. , Kisseleva Tatiana
Published: July 2014

Significance

Liver resident activated hepatic stellate cells (aHSCs), and activated portal fibroblasts (aPFs) are the major source of the fibrous scar in the liver. aPFs have been implicated in liver fibrosis caused by cholestatic liver injury, whereas fibrosis in hepatotoxic liver injury is attributed to aHSCs. However, the contribution of aPFs to cholestatic fibrosis is not well characterized because of difficulties in cell purification and the lack of identified aPF-specific markers. We have developed a novel flow cytometry-based method of aPFs purification from the nonparenchymal cell fraction of collagen-α1(I)-GFP mice and have identified potential aPF-specific markers. The goal of this study is to determine whether aPFs contribute to cholestatic liver fibrosis and identify the mechanism(s) of their activation.
Evolution of physiological responses to salt stress in hexaploid wheat
Authors: Yang Chunwu , Zhao Long , Zhang Huakun , Yang Zongze , Wang Huan , Wen Shanshan , Zhang Chunyu , Rustgi Sachin , von Wettstein Diter , Liu Bao
Published: July 2014

Significance

Hexaploid bread wheat is generally more salt tolerant than its tetraploid progenitor. However, the physiological bases and the relative contributions of immediate effects of polyploidization and subsequently acquired adaptive changes in the salt tolerance of hexaploid wheat remained elusive. This study compared a large suite of morphophysiological traits in synthetic and natural hexaploid wheats, and their tetraploid and diploid progenitors, under normal and salt-stressed conditions, and studied subgenome-specific expression of a critical salt-tolerance gene,
HKT1;5
. Results have thrown light on the major physiological bases underlying salt tolerance of hexaploid wheat and revealed polyploidy-induced alteration in gene regulation under salt stress. These allopolyploidization-induced immediate molecular and physiological changes showed evolutionary perseverance and hence bear implications for polyploid crop improvement.
iBiology: communicating the process of science
Authors: Goodwin Sarah S.
Published: July 2014

The Internet hosts an abundance of science video resources aimed at communicating scientific knowledge, including webinars, massive open online courses, and TED talks. Although these videos are efficient at disseminating information for diverse types of users, they often do not demonstrate the process of doing science, the excitement of scientific discovery, or how new scientific knowledge is developed. iBiology ( www.ibiology.org ), a project that creates open-access science videos about biology research and science-related topics, seeks to fill this need by producing videos by science leaders that make their ideas, stories, and experiences available to anyone with an Internet connection.
Trowel: a fast and accurate error correction module for Illumina sequencing reads
Authors: Lim Eun-Cheon , Müller Jonas , Hagmann Jörg , Henz Stefan R. , Kim Sang-Tae , Weigel Detlef
Published: July 2014

Motivation: The ability to accurately read the order of nucleotides in DNA and RNA is fundamental for modern biology. Errors in next-generation sequencing can lead to many artifacts, from erroneous genome assemblies to mistaken inferences about RNA editing. Uneven coverage in datasets also contributes to false corrections.

Result: We introduce Trowel, a massively parallelized and highly efficient error correction module for Illumina read data. Trowel both corrects erroneous base calls and boosts base qualities based on the k -mer spectrum. With high-quality k -mers and relevant base information, Trowel achieves high accuracy for different short read sequencing applications.The latency in the data path has been significantly reduced because of efficient data access and data structures. In performance evaluations, Trowel was highly competitive with other tools regardless of coverage, genome size read length and fragment size.

Availability and implementation: Trowel is written in C++ and is provided under the General Public License v3.0 (GPLv3). It is available at http://trowel-ec.sourceforge.net .

Contact:  euncheon.lim@tue.mpg.de or weigel@tue.mpg.de

Supplementary information:  Supplementary data are available at Bioinformatics online.