bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct numerical simulations of an inertial wave attractor in linear and nonlinear regimes
Authors: Jouve Laurène , Ogilvie Gordon I.
Published: March 2014

In a uniformly rotating fluid, inertial waves propagate along rays that are inclined to the rotation axis by an angle that depends on the wave frequency. In closed domains, multiple reflections from the boundaries may cause inertial waves to focus onto particular structures known as wave attractors. These attractors are likely to appear in fluid containers with at least one boundary that is neither parallel nor normal to the rotation axis. A closely related process also applies to internal gravity waves in a stably stratified fluid. Such structures have previously been studied from a theoretical point of view, in laboratory experiments, in linear numerical calculations and in some recent numerical simulations. In the present paper, two-dimensional direct numerical simulations of an inertial wave attractor are presented. By varying the amplitude at which the system is forced periodically, we are able to describe the transition between the linear and nonlinear regimes as well as the characteristic properties of the two situations. In the linear regime, we first recover the results of the linear calculations and asymptotic theory of Ogilvie (J. Fluid Mech., vol. 543, 2005, pp. 19–44) who considered a prototypical problem involving the focusing of linear internal waves into a narrow beam centred on a wave attractor in a steady state. The velocity profile of the beam and its scalings with the Ekman number, as well as the asymptotic value of the dissipation rate, are found to be in agreement with the linear theory. We also find that, as the beam builds up around the wave attractor, the power input by the applied force reaches its limiting value more rapidly than the dissipation rate, which saturates only when the beam has reached its final thickness. In the nonlinear regime, the beam is strongly affected and becomes unstable to a subharmonic instability. This instability transfers energy to secondary waves possessing shorter wavelengths and lower frequencies. The onset of the instability of a narrow inertial wave beam is investigated by means of a separate linear analysis and the results, such as the onset of the instability, are found to be consistent with the global simulations of the wave attractor. The excitation of such secondary waves described theoretically in this work has also been seen in recent laboratory experiments on internal gravity waves.
Dispersion in the large-deviation regime. Part 1: shear flows and periodic flows
Authors: Haynes P. H. , Vanneste J.
Published: March 2014

The dispersion of a passive scalar in a fluid through the combined action of advection and molecular diffusion is often described as a diffusive process, with an effective diffusivity that is enhanced compared with the molecular value. However, this description fails to capture the tails of the scalar concentration distribution in initial-value problems. To remedy this, we develop a large-deviation theory of scalar dispersion that provides an approximation to the scalar concentration valid at much larger distances away from the centre of mass, specifically distances that are$O(t)$rather than$O(t^{1/2})$, where$t \gg 1$is the time from the scalar release. The theory centres on the calculation of a rate function characterizing the large-time form of the scalar concentration. This function is deduced from the solution of a one-parameter family of eigenvalue problems which we derive using two alternative approaches, one asymptotic, the other probabilistic. We emphasize the connection between the large-deviation theory and the homogenization theory that is often used to compute effective diffusivities: a perturbative solution of the eigenvalue problems in the appropriate limit reduces at leading order to the cell problem of homogenization theory. We consider two classes of flows in some detail: shear flows and periodic flows with closed streamlines (cellular flows). In both cases, large deviation generalizes classical results on effective diffusivity and captures new phenomena relevant to the tails of the scalar distribution. These include approximately finite dispersion speeds arising at large Péclet number$\mathit{Pe}$(corresponding to small molecular diffusivity) and, for two-dimensional cellular flows, anisotropic dispersion. Explicit asymptotic results are obtained for shear flows in the limit of large$\mathit{Pe}$. (A companion paper, Part 2, is devoted to the large-$\mathit{Pe}$asymptotic treatment of cellular flows.) The predictions of large-deviation theory are compared with Monte Carlo simulations that estimate the tails of concentration accurately using importance sampling.
An auditory profile of sclerosteosis
Authors: Potgieter J M , Swanepoel D W , Heinze B M , Hofmeyr L M , Burger A A S , Hamersma H
Published: March 2014

Objective:

To characterise auditory involvement secondary to excessive craniotubular bone growth in individuals with sclerosteosis in South Africa.

Methods:

This cross-sectional study assessed the auditory profile of 10 participants with sclerosteosis. An auditory test battery was used and results for each ear were recorded using descriptive and comparative analyses.

Results:

All participants presented with bilateral, mixed hearing losses. Of the 20 ears, hearing loss was moderate in 5 per cent (n = 1), severe in 55 per cent (n = 11) and profound in 40 per cent (n = 8). Air–bone gaps were smaller in older participants, although the difference was not statistically significant (p > 0.05). Computed tomography scans indicated pervasive abnormalities of the external auditory canal, tympanic membrane, middle-ear space, ossicles, oval window, round window and internal auditory canal. Narrowed internal auditory canals corresponded to poor speech discrimination, indicative of retrocochlear pathology and absent auditory brainstem response waves.

Conclusion:

Progressive abnormal bone formation in sclerosteosis involves the middle ear, the round and oval windows of the cochlea, and the internal auditory canal. The condition compromises conductive, sensory and neural auditory pathways, which results in moderate to profound, mixed hearing loss.
Dynamic rolling analysis of triangular-bipyramid robot
Authors: Tian Yaobin , Yao Yan-An
Published: March 2014

In this paper a rolling robot resembling the shape of a triangular-bipyramid is proposed. The robot has three degrees of freedom and is formed by connecting two tripod mechanisms with three spherical joints. By kinematic analysis, the robot can be viewed as a planar four-bar linkage. Further, its dynamic rolling ability is discussed by Zero Moment Point (ZMP) analysis. We show that the robot has the capability to roll, adjust its step length, and switch rolling directions. These functions are verified by a series of simulations with a CAD (computer-aided design) model and experiments with a prototype.
DELAY IN A TANDEM QUEUEING MODEL WITH MOBILE QUEUES: AN ANALYTICAL APPROXIMATION
Authors: Al Hanbali Ahmad , de Haan Roland , Boucherie Richard J. , van Ommeren Jan-Kees
Published: March 2014

In this paper, we analyze the end-to-end delay performance of a tandem queueing system with mobile queues. Due to state-space explosion, there is no hope for a numerical exact analysis for the joint-queue-length distribution. For this reason, we present an analytical approximation that is based on queue-length analysis. Through extensive numerical validation, we find that the queue-length approximation exhibits excellent performance for light traffic load.
Eliminating Extreme Inequality: A Sustainable Development Goal, 2015–2030
Authors: Doyle Michael W. , Stiglitz Joseph E.
Published: March 2014

At the United Nations Millennium Summit in September 2000, UN member states took a dramatic step by putting people rather than states at the center of the UN's agenda. In their Millennium Declaration, the assembled world leaders agreed to a set of breathtakingly broad goals touching on peace through development, the environment, human rights, the protection of the vulnerable, the special needs of Africa, and reforms of UN institutions. Particularly influential was the codification of the Declaration's development-related objectives, which emerged in the summer of 2001 as the now familiar eight Millennium Development Goals (MDGs), to be realized by 2015.
The Contemporary Relevance of Buddha
Authors: Sen Amartya
Published: March 2014

The great poet and novelist Rabindranath Tagore (1861–1941) once remarked that he was extremely sad that he was not alive when Gautama Buddha was still around. Tagore very much wished he could have had conversations with Buddha. I share that sentiment, but, like Rabindranath, I am also immensely grateful that, even now, we can enjoy—and learn from—the ideas and arguments that Buddha gave us twenty-five hundred years ago. Our world may be very different from what Buddha faced in the sixth century bce, but we can still benefit greatly from the reasoned approach to ethics, politics, and social relations that Gautama Buddha brought to the world of human understanding.
Coalitions of the Willing and Responsibilities to Protect: Informal Associations, Enhanced Capacities, and Shared Moral Burdens
Authors: Erskine Toni
Published: March 2014

“Coalition of the willing” is a phrase that we hear invoked with frequency in world politics. Significantly, it is generally accompanied by claims to moral responsibility. Yet the label commonly used to connote a temporary, purpose-driven, self-selected collection of states sits uneasily alongside these assertions of moral responsibility.

This article explores how the informal nature of such associations should inform judgments of moral responsibility. I begin by briefly recounting what I call a model of institutional moral agency in order to explain why it seems theoretically and practically problematic to talk about the moral responsibilities of informal associations. I then focus on coalitions of the willing as prominent, and challenging, examples of such associations, before raising misgivings about my own rather stark distinction if it means that accounts of moral responsibility must be reduced to the members—or potential members—of such coalitions in a way that neglects the moral significance of their acting together. Prompted by these concerns, I explore arguments by Virginia Held and Larry May about moral responsibility in relation to informal associations and identify insights that can be taken from these positions to refine our expectations and evaluations of the actions associated with such collectivities. Finally, I consider the particular implications of these insights in relation to the widely espoused duty to intervene to rescue vulnerable populations.
Streptococcus pneumoniaeserogroup 6 clones over two decades
Authors: PAYNE D. B. , GRAY B. M.
Published: March 2014

The major evolutionary stresses onStreptococcus pneumoniaeare thought to be the widespread use of antibiotics and the deployment of effective vaccines against the capsular polysaccharides. Our current knowledge of genetic lineages among pneumococcal isolates comes largely from investigations just before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) introduced in 2000. We examined 66 serogroup 6 isolates from the 1970s, long before the introduction of PCV7 and before widespread penicillin resistance was common in Birmingham, Alabama, to look for ancestors of the clones that came into play around the introduction of the PCV7 vaccine. The hypothesis was that some clonal complexes, if not individual clones, would be stable enough to persist over this period of time. We compared the 1970s isolates with 122 isolates from the 1990s in US and worldwide collections. Genotyping with pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) revealed that while some clones were probably localized to our area, others have persisted within groups that have expanded or diminished over the years.
A study of learners’ perceptions of online intercultural exchange through Web 2.0 technologies
Authors: Lee Lina , Markey Alfred
Published: March 2014

This paper reports a Spanish-American telecollaborative project through which students usedTwitter, blogs and podcasts for intercultural exchange over the course of one semester. The paper outlines the methodology for the project including pedagogical objectives, task design, selection of web tools and implementation. Using qualitative and quantitative data collection, the study explored how the application of Web 2.0 facilitated cross-cultural communication. How the use of digital technology affected the way in which the students viewed intercultural learning and peer feedback was examined. The findings showed that students viewed the online exchange as a superb venue for intercultural communication with native speakers. Through social engagements, students not only gained cultural knowledge but also became more aware of their own beliefs and attitudes toward their own culture. In addition, discussions on topics of tangible and intangible cultures afforded the opportunity to raise students’ awareness of cultural norms and practices. Peer feedback helped learners increase lexical knowledge, prevent language fossilization, and acquire native-sounding discourse. The study suggests that allocating sufficient time to complete each task and making personal commitment to online contributions are essential to successful intercultural exchanges.
Use of Point-of-Care Lactate in the Prehospital Aeromedical Environment
Authors: Mullen Marie , Cerri Gianluca , Murray Ryan , Talbot Angela , Sanseverino Alexandra , McCahill Peter , Mangolds Virginia , Volturo Jesse , Darling Chad , Restuccia Marc
Published: March 2014

Introduction

Lactate measurement has been used to identify critical medical illness and initiate early treatment strategies. The prehospital environment offers an opportunity for very early identification of critical illness and commencement of care.

Hypothesis

The investigators hypothesized that point-of-care lactate measurement in the prehospital aeromedical environment would: (1) identify medical patients with high mortality; (2) influence fluid, transfusion, and intubation; and (3) increase early central venous catheter (CVC) placement.

Methods

Critically ill, medical, nontrauma patients who were transported from September 2007 through February 2009 by University of Massachusetts (UMass) Memorial LifeFlight, a university-based emergency medical helicopter service, were eligible for enrollment. Patients were prospectively randomized to receive a fingerstick whole-blood lactate measurement on an alternate-day schedule. Flight crews were not blinded to results. Flight crews were asked to inform the receiving attending physician of the results. The primary endpoint was the ability of a high, prehospital lactate value [> 4 millimoles per liter (mmol/L)] to identify mortality. Secondary endpoints included differences in post-transport fluid, transfusion, and intubation, and decrease in time to central venous catheter (CVC) placement. Categorical variables were compared between groups by Fisher's Exact Test, and continuous variables were compared by t-test.

Results

Patients (N = 59) were well matched for age, gender, and acuity. In the lactate cohort (n = 20), mean lactate was 7 mmol/L [Standard error of the mean, SEM = 1]. Initial analysis revealed that prehospital lactate levels of ≥4 mmol/L did show a trend toward higher mortality with an odds ratio of 2.1 (95% CI, 0.3-13.8). Secondary endpoints did not show a statistically significant change in management between the lactate and non lactate groups. There was a trend toward decreased time to post-transport CVC in the non lactate faction.

Conclusion

Prehospital aeromedical point-of-care lactate measurement levels ≥4 mmol/L may help stratify mortality. Further investigation is needed, as this is a small, limited study. The initial analysis did not find a significant change in post-transport management.

MullenM, CerriG, MurrayR, TalbotA, SanseverinoA, McCahillP, MangoldsV, VolturoJ, DarlingC, RestucciaM. Use of point-of-care lactate in the prehospital aeromedical environment. Prehosp Disaster Med. 2014;29(1):1-4.
General Household Emergency Preparedness: A Comparison Between Veterans and Nonveterans
Authors: Der-Martirosian Claudia , Strine Tara , Atia Mangwi , Chu Karen , Mitchell Michael N. , Dobalian Aram
Published: March 2014

Background

Despite federal and local efforts to educate the public to prepare for major emergencies, many US households remain unprepared for such occurrences. United States Armed Forces veterans are at particular risk during public health emergencies as they are more likely than the general population to have multiple health conditions.

Methods

This study compares general levels of household emergency preparedness between veterans and nonveterans by focusing on seven surrogate measures of household emergency preparedness (a 3-day supply of food, water, and prescription medications, a battery-operated radio and flashlight, a written evacuation plan, and an expressed willingness to leave the community during a mandatory evacuation). This study used data from the 2006 through 2010 Behavioral Risk Factor Surveillance System (BRFSS), a state representative, random sample of adults aged 18 and older living in 14 states.

Results

The majority of veteran and nonveteran households had a 3-day supply of food (88% vs 82%, respectively) and prescription medications (95% vs 89%, respectively), access to a working, battery-operated radio (82% vs 77%, respectively) and flashlight (97% vs 95%, respectively), and were willing to leave the community during a mandatory evacuation (91% vs 96%, respectively). These populations were far less likely to have a 3-day supply of water (61% vs 52%, respectively) and a written evacuation plan (24% vs 21%, respectively). After adjusting for various sociodemographic covariates, general health status, and disability status, households with veterans were significantly more likely than households without veterans to have 3-day supplies of food, water, and prescription medications, and a written evacuation plan; less likely to indicate that they would leave their community during a mandatory evacuation; and equally likely to have a working, battery-operated radio and flashlight.

Conclusion

These findings suggest that veteran households appear to be better prepared for emergencies than do nonveteran households, although the lower expressed likelihood of veterans households to evacuate when ordered to do so may place them at a somewhat greater risk of harm during such events. Further research should examine household preparedness among other vulnerable groups including subgroups of veteran populations and the reasons why their preparedness may differ from the general population.

Der-MartirosianC, StrineT, AtiaM, ChuK, MitchellMN, DobalianA. General household emergency preparedness: a comparison between veterans and nonveterans. Prehosp Disaster Med. 2014;29(2):1-7.
Shi‘ism, Humanity and Revolution in Twentieth-Century India: Selfhood and Politics in the Husainology of ‘Ali Naqi Naqvi
Authors: JONES JUSTIN
Published: March 2014

The story of Imam Husain's martyrdom at Karbala has been told with variant emphases and interpretations in different historical contexts. This article examines one of the most famous modern tellings of this narrative: that of ‘Ali Naqi Naqvi, arguably South Asia's most influential Shi‘imujtahidof the twentieth century. It argues that, from the 1930s–1940s, ‘Ali Naqi pioneered a novel perspective on Imam Husain, establishing him as a model for human comportment and a figure to be actively emulated, both by Shi‘as and by humanity at large. As well as having implications for transformation within Shi‘ism, this reorientation of Husain's significance pre-empted its politicisation: ‘Ali Naqi's message informed the incorporation of Shi‘i symbology within the 1942 Quit India agitation, and in some senses exhibited parallels with the later revolutionary rendering of the Karbala message in 1960s–1970s Iran. It is the range of the religious and political implications to be drawn from Ali Naqi's interpretation that have ensured both the durability, and ongoing controversy, of his Husainology.
Local Nodes of a Transnational Network: a case study of a Shi‘i family in Awadh, 1900–1950
Authors: KHAN MUHAMMAD AMIR AHMAD
Published: March 2014

This article studies two generations of the Mahmudabad family, which was one of the largest Muslim landholding families in India: Maharaja Sir Muhammad ‘Ali Muhammad Khan and Raja Muhammad Amir Ahmad Khan. The family were Twelver Shi‘as and hailed from Mahmudabad in Awadh. Specifically, it shows how intra-community links of marriage and kinship facilitated a flow of ideas, information and people and therefore created new networks. The article then explores these connections through the example of the Madrasa’t-ul Wa‘izeen, which was founded by the Maharaja and its two main publications,Al-Wa‘iz, an Urdu magazine and the English languageThe Muslim Review. The founding of themadrasaalso demonstrates the importance of ideology, pilgrimage, preaching and their corresponding networks. These relationships are analysed keeping in mind local, national and transnational institutions and the role these played in creating ties between Mahmudabad, Lucknow and the wider Muslim world. This article thus presents a typology of a particular kind of Muslim transnationalism, showing how family, marriage, ideology and the importance of preaching mutually reinforced each other. The larger goal is to show how this family could be both ‘rooted’ in the local while also being part of the transnational Muslim community.
Discussion of the operating range of frequency modulated radars in the presence of interference
Authors: Schipper Tom , Harter Marlene , Mahler Tobias , Kern Oliver , Zwick Thomas
Published: March 2014

This paper discusses the operating range of frequency modulated (FM) radars in the presence of interference. For this purpose, radar- and path loss equations are used to draw the equipotential lines for a given signal-to-interference ratio as a function of the spatial distribution of targets and interferers in order to identify relevant scenario constellations. Further the factors influencing the gain of signal versus deterministic interference are discussed based on measurements and simulations. Finally, the influence of different kinds of interference on the spectrum of a frequency modulated continuous wave radar is shown.
TDOA estimation method using 60 GHz OFDM spectrum
Authors: Jafari Ahmadreza , Petrillo Luca , Sarrazin Julien , Lautru David , De Doncker Philippe , Benlarbi-Delai Aziz
Published: March 2014

In the field of high data rate wireless communications, localization issues play a key role in achieving energy-efficient communication and geographic routing. time-difference of arrival (TDOA)-based localization methods present numerous advantages. In this paper, a new method of TDOA estimation is proposed. With this method, unlike conventional TDOA measurements, it is possible to perform communication and localization at the same time by using a multi-input single-output system. By transmitting ultra-wide-band orthogonal frequency-division multiplexing signals using spatial diversity, it is possible to extract TDOA from interference patterns in spectral domain. In addition, increasing the precision of localization is also studied using a multi-band approach. This whole study is made within the framework of the WiGig alliance specifications; however, it is compatible with other standards.
Design and analysis of stair-shape UWB antenna with flowery DGS
Authors: Kaur Sukhdeep , Khanna Rajesh
Published: March 2014

In this paper, staircase-shaped ultra-wideband (UWB) response is proposed. UWB technology being emerging technology of decade needs development of antennas with small size. This paper proposed the design of antennas for UWB technology with small overall size. The feed used in the proposed design is microstrip feed line. The defected ground structure and staircase patch have been used to enhance bandwidth (BW) of antenna, to miniaturize its shape and to reduce the surface wave. The proposed design is carried out with different types of substrate materials and the best results are considered. The proposed antenna performs well in terms of BW and gain while reduction in size is reported. The proposed antenna can be used for Wireless Personal Area Network.
Cerebral Hemodynamics in Normal Aging: Central Artery Stiffness, Wave Reflection, and Pressure Pulsatility
Authors: Tarumi Takashi , Khan Muhammad Ayaz , Liu Jie , Tseng Benjamin M , Parker Rosemary , Riley Jonathan , Tinajero Cynthia , Zhang Rong
Published: March 2014

Blood ejected from the left ventricle perfuses the brain via central elastic arteries, which stiffen with advancing age and may elevate the risk of end-organ damage. The purpose of this study was to determine the impact of central arterial aging on cerebral hemodynamics. Eighty-three healthy participants aged 22 to 80 years underwent the measurements of cerebral blood flow (CBF) and CBF velocity (CBFV) using magnetic resonance imaging (MRI) and transcranial Doppler, respectively. The CBF pulsatility was determined by the relative amplitude of CBFV to the mean value (CBFV%). Central arterial stiffness (carotid-femoral pulse wave velocity), wave reflection (carotid augmentation index), and pressure were measured using applanation tonometry. Total volume of white-matter hyperintensity (WMH) was quantified from MR images. Total CBF decreased with age while systolic and pulsatile CBFV% increased and diastolic CBFV% decreased. Women showed greater total CBF and lower cerebrovascular resistance than men. Diastolic CBFV% was lower in women than in men. Age- and sex-related differences in CBF pulsatility were independently associated with carotid pulse pressure and arterial wave reflection. In older participants, higher pulsatility of CBF was associated with the greater total volume of WMH. These findings indicate that central arterial aging has an important role in age-related differences in cerebral hemodynamics.
Dye-doped silica nanoparticles as luminescent organized systems for nanomedicine
Authors: Montalti M. , Prodi L. , Rampazzo E. , Zaccheroni N.
Published: March 2014

This review summarizes developments and applications of luminescent dye doped silica nanoparticles as versatile organized systems for nanomedicine.
When self-assembly meets biology: luminescent platinum complexes for imaging applications
Authors: Mauro Matteo , Aliprandi Alessandro , Septiadi Dedy , Kehr Nermin Seda , De Cola Luisa
Published: March 2014

Self-assembled luminescent structures based on platinum complexes. A new tool for bioimaging?
Nanoparticle emissions from traditional pottery manufacturing
Authors: Voliotis Aristeidis , Bezantakos Spyros , Giamarelou Maria , Valenti Marco , Kumar Prashant , Biskos George
Published: March 2014

Traditional manufacturing of pottery tableware and ornamental ware involves firing of the ceramics; a process that leads to high concentrations of airborne nanoparticles that are harmful to human health. This paper reports systematic measurements of the size distributions and the elemental composition of nanoparticles emitted during the two firing stages of ceramics.
An XPS/AES comparative study of the surface behaviour of nano-silicon anodes for Li-ion batteries
Authors: Radvanyi Etienne , De Vito Eric , Porcher Willy , Jouanneau Si Larbi Séverine
Published: March 2014

By analyzing Si anodes using XPS and AES, both the SEI behaviour and the lithiation mechanisms are studied upon cycling.
Oxidative damage to rat brain in iron and copper overloads
Authors: Musacco-Sebio Rosario , Ferrarotti Nidia , Saporito-Magriñá Christian , Semprine Jimena , Fuda Julián , Torti Horacio , Boveris Alberto , Repetto Marisa G.
Published: March 2014

Increased cytosolic levels of Fe2+, Cu+and H2O2are central to the hypothesis that Fe and Cu toxicities are mediated by OH˙ formation and oxidative damage due to phospholipids and proteins oxidation.
Assembly of indole fluorophore in situ for hydrogen sulfide signaling through substrate triggered intramolecular reduction–cyclization cascade: a sensitive and selective probe in aqueous solution
Authors: Zhou Ji , Luo Yuanyuan , Li Qiang , Shen Jiaoning , Wang Rui , Xu Yufang , Qian Xuhong
Published: March 2014

The fluorescence enhancement is due to the formation of the indole fluorophore through reduction by H2S and cyclization.
Synthesis of zinc–nickel ferrite nanorods and their magnetic properties
Authors: Hao Liang , Zhao Yun , Jiao Qingze , Chen Puteng
Published: March 2014

Zinc–nickel (Zn–Ni) ferrite nanorods were synthesized by a microemulsion-based method in combination with calcination at different temperatures.
Sensitive naked-eye detection of Hg2+based on the aggregation and filtration of thymine functionalized vesicles caused by selective interaction between thymine and Hg2+
Authors: Ma Xue , Sheng Zhonghan , Jiang Long
Published: March 2014

A sensitive and low-cost method based on rapid interaction between functionalized PDA vesicles and Hg2+for the naked-eye detection of Hg2+.
Alkaloids analysis using off-line two-dimensional supercritical fluid chromatography × ultra-high performance liquid chromatography
Authors: Li Kuiyong , Fu Qing , Xin Huaxia , Ke Yanxiong , Jin Yu , Liang Xinmiao
Published: March 2014

2-D SFC × UHPLC method with high orthogonality for analysis of the amide alkaloids fraction of P. longum L.
Online coupling lab on valve-dispersive liquid–liquid microextraction-multisyringe flow injection with gas chromatography-mass spectrometry for the determination of sixteen priority PAHs in water
Authors: Clavijo Sabrina , Fernández Mailén , Forteza Rafael , Brunetto Maria del Rosario , Cerdà Víctor
Published: March 2014

Online gas chromatography-mass spectrometry determination of priority PAHs in water.
Colorimetric detection of ATP with DNAzyme: design an activatable hairpin probe for reducing background signals and improving selectivity
Authors: Chen Weiju , Hu Yaping , Li Jishan , Li Yinhui , Bai Junhui , Zheng Jing , Yang Ronghua
Published: March 2014

An activatable hairpin DNA probe, which includes the HRP-mimicking G-quadruplex, was designed and utilized for colorimetric detection of ATP.
Effects of lamp power and mirror position on the interface shape of the silicon molten zone during infrared convergent heating
Authors: Hossain Md. Mukter , Watauchi Satoshi , Nagao Masanori , Tanaka Isao
Published: March 2014

The effects of lamp power and mirror position on the feed–melt and crystal–melt interfaces during the growth of a silicon crystal were examined using the mirror-shifting-type infrared convergent-heating floating-zone (IR-FZ) method.
Stabilizing chromophore binding on TiO2 for long-term stability of dye-sensitized solar cells using multicomponent atomic layer deposition
Authors: Kim Do Han , Losego Mark D. , Hanson Kenneth , Alibabaei Leila , Lee Kyoungmi , Meyer Thomas J. , Parsons Gregory N.
Published: March 2014

Dye sensitized solar cells (DSSCs) are coated with subnanometer oxide coatings to prevent device degradation in ambient humidity and high temperatures.
Folates are potential ligands for ruthenium compounds in vivo
Authors: Scrase Tom G. , Page Simon M. , Barker Paul D. , Boss Sally R.
Published: March 2014

A labile ruthenium(ii) complex has been observed to chelate to folates under physiologically relevant conditions. The diastereomeric complexes formed would interfere with the one-carbon carrying role of folatein vivo. This highlights the importance of considering small molecules alongside macromolecules when determining the chemical origins of cytotoxicity of metallodrug candidates.
Application of quasi-equilibrated thermodesorption of linear and di-branched paraffin molecules for detailed porosity characterization of the mono-layered zeolite MCM-56, in comparison with MCM-22 and ZSM-5
Authors: Makowski Wacław , Mlekodaj Kinga , Gil Barbara , Roth Wiesław J. , Marszałek Bartosz , Kubu Martin , Hudec Pavol , Smiešková Agáta , Horňáček Michal
Published: March 2014

Thermodesorption of 2,2-dimethyloctane reveals different content of subsurface micropores in MWW-type zeolites.
Novel surfactant-free route to delaminated all-silica and titanosilicate zeolites derived from a layered borosilicate MWW precursor
Authors: Ouyang Xiaoying , Wanglee Ying-Jen , Hwang Son-Jong , Xie Dan , Rea Thomas , Zones Stacey I. , Katz Alexander
Published: March 2014

Layered borosilicate zeolite precursor ERB-1P (Si/B = 11) is delaminated via simultaneous deboronation and SDA removal, to yield material DZ-1 consisting of silanol nests, using a simple aqueous Zn(NO3)2 treatment.
Redefining efficiency for outdoor lighting
Authors: Kyba C. C. M. , Hänel A. , Hölker F.
Published: March 2014

Lighting policies intended to reduce energy use must focus on energy consumed per year, rather than on luminous efficiency.
Good's buffers as a basis for developing self-buffering and biocompatible ionic liquids for biological research
Authors: Taha Mohamed , e Silva Francisca A. , Quental Maria V. , Ventura Sónia P. M. , Freire Mara G. , Coutinho João A. P.
Published: March 2014

This work reports a promising approach to the development of novel self-buffering and biocompatible ionic liquids for biological research in which the anions are derived from biological buffers (Good's buffers, GB).
1,3-Carbon D–A strategy for [3 + 2] cycloadditions/annulations with imines: synthesis of functionalized pyrrolidines and related alkaloids
Authors: Kumar Indresh
Published: March 2014

[3 + 2] Cycloaddition/annulation: this article summarize the recent developments in synthesis of pyrrolidines and related alkaloids through complementary [3 + 2] cycloaddition/annulation of 1,3-carbon D–A precursors with imines.
Luminol chemiluminescence enhanced by copper nanoclusters and its analytical application
Authors: Xu Shuangjiao , Chen Funan , Deng Mao , Sui Yanyan
Published: March 2014

It was found that Cu nanoclusters could enhance the chemiluminescence (CL) emission from the luminol–hydrogen peroxide system in an alkaline medium.
Role of carbon content in qualifying Li3V2(PO4)3/C as a high capacity anode for high rate lithium battery applications
Authors: Mani V. , Nathiya K. , Kalaiselvi N.
Published: March 2014

Nanocrystalline Li3V2(PO4)3 has been prepared by the oxalic dihydrazide assisted combustion (ODHAC) method, and the corresponding Li3V2(PO4)3/C composites containing different concentrations of super P carbon, viz. 10, 20 and 30 wt% have been explored individually as anodes for lithium batteries.
Zinc-seamed pyrogallol[4]arene dimers as structural components in a two-dimensional MOF
Authors: Mossine Andrew V. , Mayhan Collin M. , Fowler Drew A. , Teat Simon J. , Deakyne Carol A. , Atwood Jerry L.
Published: March 2014

Computational methods were used as a proof of principle in the synthesis of a two-dimensional coordination polymer constructed from zinc-seamed pyrogallol[4]arene dimeric nanocapsules and 4,4′-bipyridine.
V-substituted In2S3: an intermediate band material with photocatalytic activity in the whole visible light range
Authors: Lucena Raquel , Conesa José C. , Aguilera Irene , Palacios Pablo , Wahnón Perla
Published: March 2014

Substituting In by V in In2S3extends its photocatalytic ability to the whole visible light range. This involves a two-photon process facilitated by the intermediate band predicted by quantum calculations.
TIMP-1 modulates chemotaxis of human neural stem cells through CD63 and integrin signalling
Authors: Lee Soo Youn , Kim Jung Mi , Cho Soo Young , Kim Hyun Suk , Shin Hee Sun , Jeon Jeong Yong , Kausar Rukhsana , Jeong Seon Yong , Lee Young Seek , Lee Myung Ae
Published: March 2014

We recently reported that hNSCs (human neural stem cells) have the interesting characteristic of migration towards an intracranial glioma. However, the molecules and mechanisms responsible for tumour tropism are unclear. In the present study, we used microarray and proteomics analyses to identify a novel chemoattractant molecule, TIMP-1 (tissue inhibitor of metalloproteinase-1), secreted from human brain tumour tissues. We demonstrate that TIMP-1 significantly enhances hNSC adhesion and migration in a cell culture system. These effects were critically dependent on CD63, as shRNA-mediated ablation of CD63 expression attenuated the response. TIMP-1 significantly increased the number of FAs (focal adhesions) and cytoskeletal reorganization for cell migration in hNSCs, whereas knockdown of CD63 resulted in decreased hNSC spreading, FAs and migration, even after TIMP-1 treatment. In addition, TIMP-1 binding to CD63 activated β1 integrin-mediated signalling through Akt and FAK phosphorylation, leading to pattern changes in distribution of vinculin and F-actin (filamentous actin). Furthermore, inactivation of β1 integrin by use of a blocking antibody or inhibition of PI3K (phosphoinositide 3-kinase) signalling impaired the migration of hNSCs towards TIMP-1. Collectively, our results underline TIMP-1 as a novel and effective key regulator of CD63 and β1 integrin-mediated signalling, which regulates hNSC adhesion and migration.
Myoplasmic resting Ca2+ regulation by ryanodine receptors is under the control of a novel Ca2+-binding region of the receptor
Authors: Chen Yanyi , Xue Shenghui , Zou Juan , Lopez Jose R. , Yang Jenny J. , Perez Claudio F.
Published: March 2014

Passive SR (sarcoplasmic reticulum) Ca2+ leak through the RyR (ryanodine receptor) plays a critical role in the mechanisms that regulate [Ca2+]rest (intracellular resting myoplasmic free Ca2+ concentration) in muscle. This process appears to be isoform-specific as expression of either RyR1 or RyR3 confers on myotubes different [Ca2+]rest. Using chimaeric RyR3–RyR1 receptors expressed in dyspedic myotubes, we show that isoform-dependent regulation of [Ca2+]rest is primarily defined by a small region of the receptor encompassing amino acids 3770–4007 of RyR1 (amino acids 3620–3859 of RyR3) named as the CLR (Ca2+ leak regulatory) region. [Ca2+]rest regulation by the CLR region was associated with alteration of RyRs’ Ca2+-activation profile and changes in SR Ca2+-leak rates. Biochemical analysis using Tb3+-binding assays and intrinsic tryptophan fluorescence spectroscopy of purified CLR domains revealed that this determinant of RyRs holds a novel Ca2+-binding domain with conformational properties that are distinctive to each isoform. Our data suggest that the CLR region provides channels with unique functional properties that modulate the rate of passive SR Ca2+ leak and confer on RyR1 and RyR3 distinctive [Ca2+]rest regulatory properties. The identification of a new Ca2+-binding domain of RyRs with a key modulatory role in [Ca2+]rest regulation provides new insights into Ca2+-mediated regulation of RyRs.
Analysis of the Leishmania peroxin 7 interactions with peroxin 5, peroxin 14 and PTS2 ligands
Authors: Pilar Ana Victoria C. , Strasser Rona , McLean James , Quinn Elizabeth , Cyr Normand , Hojjat Hamed , Kottarampatel Anwer Hasil , Jardim Armando
Published: March 2014

LPEX7 (Leishmania peroxin 7) is essential for targeting newly synthesized proteins with a PTS2 (peroxisome-targeting signal type 2) import signal into the glycosome. In the present paper, we describe the biophysical characterization of a functional LPEX7 isolated from Escherichia coli inclusion bodies. Pull-down assays showed that LPEX7 binds the interacting partners LdPEX5 (Leishmania donovani peroxin 5) and LdPEX14, but, more importantly, this receptor can specifically bind PTS2 cargo proteins in the monomeric and dimeric states. However, in the absence of interacting partners, LPEX7 preferentially adopts a tetrameric structure. Mapping studies localized the LdPEX5- and LdPEX14-binding sites to the N-terminal portion of LPEX7. Deletion of the first 52 residues abolished LdPEX14 association without altering the LdPEX5 interaction. Intrinsic fluorescence techniques suggested that each LPEX7 subunit has a single unique binding site for each of the respective interacting partners LdPEX5, LdPEX14 and PTS2 cargo proteins. Extrinsic fluorescence studies with ANS (8-anilinonaphthalene-1-sulfonic acid) demonstrated that LPEX7 contains a surface-exposed hydrophobic region(s) that was not altered by the binding of a PTS2 protein or LdPEX5. However, in the presence of these ligands, the accessibility of the hydrophobic domain was dramatically restricted, suggesting that both ligands are necessary to induce notable conformational changes in LPEX7. In contrast, binding of LdPEX14 did not alter the hydrophobic domain on LPEX7. It is possible that the hydrophobic surfaces on LPEX7 may be a crucial characteristic for the shuttling of this receptor in and out of the glycosome.
Electrically widely tunable interband cascade lasers
Authors: Jiang Yuchao , Li Lu , Tian Zhaobing , Ye Hao , Zhao Lihua , Yang Rui Q. , Mishima Tetsuya D. , Santos Michael B. , Johnson Matthew B. , Mansour Kamjou
Published: March 2014

Electrically tunable interband cascade lasers are demonstrated with a wide tuning range of about 280 cm−1 (34 meV in energy or 630 nm in wavelength) near 4.5 μm and about 180 cm−1 (22 meV or 900 nm) near 7 μm wavelengths. The laser structures are designed such that the heating and Stark effects act together to enhance the red-shift of the lasing wavelength with current injection to achieve wide tunability. The control and manipulation of the tuning range and rate are discussed.
Pressure induced phase transition in MH2 (M = V, Nb)
Authors: Chen Changbo , Tian Fubo , Duan Defang , Bao Kuo , Jin Xilian , Liu Bingbing , Cui Tian
Published: March 2014

High-pressure structures of MH2 (M = V, Nb) are explored through ab initio evolutionary methodology. As the same main group metal hydrides, VH2 and NbH2 adopt the same tetragonal structure with space group Fm-3m at low pressures. However, at high pressures VH2 and NbH2 possess Pnma and P63mc phases differently. The two phase transitions are both the first order phase transition identified by volume collapses. Our calculations suggest that two high-pressure structures have both dynamical and mechanical stability up to 100 GPa. Pnma VH2 and P63mc NbH2 are metallic phases demonstrated by the band structure and density of states. However, their superconducting temperatures are only several Kelvins.
A novel structure of transmission line pulse transformer with mutually coupled windings
Authors: Yu Binxiong , Su Jiancang , Li Rui , Zhao Liang , Zhang Xibo , Wang Junjie
Published: March 2014

A novel structure of transmission line transformer (TLT) with mutually coupled windings is described in this paper. All transmission lines except the first stage of the transformer are wound on a common ferrite core for the TLT with this structure. A referral method was introduced to analyze the TLT with this structure, and an analytic expression of the step response was derived. It is shown that a TLT with this structure has a significantly slower droop rate than a TLT with other winding structures and the number of ferrite cores needed is largely reduced. A four-stage TLT with this structure was developed, whose input and output impedance were 4.2 Ω and 67.7 Ω, respectively. A frequency response test of the TLT was carried out. The test results showed that pulse response time of the TLT is several nanoseconds. The TLT described in this paper has the potential to be used as a rectangle pulse transformer with very fast response time.
A new read channel architecture using a staggered pattern for bit patterned media recording
Authors: Kong Gyuyeol , Choi Sooyong
Published: March 2014

A new read channel architecture achieving diversity effects for bit patterned magnetic recording is proposed in this paper. In the proposed channel architecture, a new channel model generating several different channels for the desired symbols and the diversity achieving detection schemes are proposed to obtain performance gains with a simple structure. By using the proposed channel model, M different channels for the M desired symbols can be generated from the M reading operations and then M different channels can be exploited to obtain spatial diversity gains with the diversity achieving detection schemes. For the diversity achieving detection schemes, a single-track interference cancellation scheme is proposed based on ordered successive interference cancellation algorithm. To consider interference from the side-tracks, a multi-track interference cancellation (MTIC) scheme is also proposed. Simulation results show that the MTIC scheme with a simpler structure yields more than 1.5 dB gains over the conventional schemes when an areal density is 3 Tb/in2.
Diode pumped solid state kilohertz disk laser system for time-resolved combustion diagnostics under microgravity at the drop tower Bremen
Authors: Wagner Volker , Paa Wolfgang , Triebel Wolfgang , Eigenbrod Christian , Klinkov Konstantin , Larionov Mikhail , Giesen Adolf , Stolzenburg Christian
Published: March 2014

We describe a specially designed diode pumped solid state laser system based on the disk laser architecture for combustion diagnostics under microgravity (μg) conditions at the drop tower in Bremen. The two-stage oscillator-amplifier-system provides an excellent beam profile (TEM00) at narrowband operation (Δλ < 1 pm) and is tunable from 1018 nm to 1052 nm. The laser repetition rate of up to 4 kHz at pulse durations of 10 ns enables the tracking of processes on a millisecond time scale. Depending on the specific issue it is possible to convert the output radiation up to the fourth harmonic around 257 nm. The very compact laser system is integrated in a slightly modified drop capsule and withstands decelerations of up to 50 g (>11 ms). At first the concept of the two-stage disk laser is briefly explained, followed by a detailed description of the disk laser adaption to the drop tower requirements with special focus on the intended use under μg conditions. In order to demonstrate the capabilities of the capsule laser as a tool for μg combustion diagnostics, we finally present an investigation of the precursor-reactions before the droplet ignition using 2D imaging of the Laser Induced Fluorescence of formaldehyde.
Ultrafast dynamics of excitons in tetracene single crystals
Authors: Birech Zephania , Schwoerer Markus , Schmeiler Teresa , Pflaum Jens , Schwoerer Heinrich
Published: March 2014

Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally overlapping transient absorption traces of single crystals were systematically deconvoluted. From this, the ultrafast dynamics of the ground, excited, and transition states were identified including singlet exciton fission into two triplet excitons. Fission is generated through both, direct fission of higher singlet states Sn on a sub-picosecond timescale, and thermally activated fission of the singlet exciton S1 on a 40 ps timescale. The high energy Davydov component of the S1 exciton is proposed to undergo fission on a sub-picoseconds timescale. At high density of triplet excitons their mutual annihilation (triplet-triplet annihilation) occurs on a <10 ps timescale.