bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrent bottlenecks in the malaria life cycle obscure signals of positive selection
Authors: CHANG HSIAO-HAN , HARTL DANIEL L.
Published: February 2014

Detecting signals of selection in the genome of malaria parasites is a key to identify targets for drug and vaccine development. Malaria parasites have a unique life cycle alternating between vector and host organism with a population bottleneck at each transition. These recurrent bottlenecks could influence the patterns of genetic diversity and the power of existing population genetic tools to identify sites under positive selection. We therefore simulated the site-frequency spectrum of a beneficial mutant allele through time under the malaria life cycle. We investigated the power of current population genetic methods to detect positive selection based on the site-frequency spectrum as well as temporal changes in allele frequency. We found that a within-host selective advantage is difficult to detect using these methods. Although a between-host transmission advantage could be detected, the power is decreased when compared with the classical Wright–Fisher (WF) population model. Using an adjusted null site-frequency spectrum that takes the malaria life cycle into account, the power of tests based on the site-frequency spectrum to detect positive selection is greatly improved. Our study demonstrates the importance of considering the life cycle in genetic analysis, especially in parasites with complex life cycles.
What is the impact of mental health-related stigma on help-seeking? A systematic review of quantitative and qualitative studies
Authors: Clement S. , Schauman O. , Graham T. , Maggioni F. , Evans-Lacko S. , Bezborodovs N. , Morgan C. , Rüsch N. , Brown J. S. L. , Thornicroft G.
Published: February 2014

Background

Individuals often avoid or delay seeking professional help for mental health problems. Stigma may be a key deterrent to help-seeking but this has not been reviewed systematically. Our systematic review addressed the overarching question: What is the impact of mental health-related stigma on help-seeking for mental health problems? Subquestions were: (a) What is the size and direction of any association between stigma and help-seeking? (b) To what extent is stigma identified as a barrier to help-seeking? (c) What processes underlie the relationship between stigma and help-seeking? (d) Are there population groups for which stigma disproportionately deters help-seeking?

Method

Five electronic databases were searched from 1980 to 2011 and references of reviews checked. A meta-synthesis of quantitative and qualitative studies, comprising three parallel narrative syntheses and subgroup analyses, was conducted.

Results

The review identified 144 studies with 90 189 participants meeting inclusion criteria. The median association between stigma and help-seeking was d = − 0.27, with internalized and treatment stigma being most often associated with reduced help-seeking. Stigma was the fourth highest ranked barrier to help-seeking, with disclosure concerns the most commonly reported stigma barrier. A detailed conceptual model was derived that describes the processes contributing to, and counteracting, the deterrent effect of stigma on help-seeking. Ethnic minorities, youth, men and those in military and health professions were disproportionately deterred by stigma.

Conclusions

Stigma has a small- to moderate-sized negative effect on help-seeking. Review findings can be used to help inform the design of interventions to increase help-seeking.
Closure of large patent ductus arteriosus using the Amplatzer Septal Occluder
Authors: García-Montes José A. , Camacho-Castro Anahí , Sandoval-Jones Juan P. , Buendía-Hernández Alfonso , Calderón-Colmenero Juan , Patiño-Bahena Emilia , Zabal Carlos
Published: February 2014

Background: Percutaneous closure of patent ductus arteriosus has become the treatment of choice in many centres. In patients with large ducts and pulmonary hypertension, transcatheter closure has been achieved with success using the Amplatzer Duct Occluder or even the Amplatzer Muscular Ventricular Septal Defect Occluder. Materials and methods: We present a series of 17 patients with large and hypertensive ductus arteriosus who were treated with an Amplatzer Septal Occluder. The group had 11 female patients (64.7%) and a mean age of 18.6±12.1 years. Results: The haemodynamic and anatomical data are as follows: pulmonary artery systolic pressure 71.3±31.8 mmHg, pulmonary to systemic flow ratio 3.14±1.36, ductal diameter at the pulmonary end 12.5±3.8 mm, and at the aortic end 20.2±7.7 mm; 14 cases (82.3%) had type A ducts. In 11 patients, we began the procedure using a different device – six with duct occluder and five with ventricular septal occluder – and it was changed because of device embolisation in six (35.3%). All septal occluders were delivered successfully. Residual shunt was moderate in six patients (35.3%), mild in eight (47%), trivial in two (11.8%), and no shunt in one (5.9%). Pulmonary systolic pressure decreased to 48.9±10.8 mmHg after occlusion (p=0.0015). Follow-up in 15 patients (88.2%) for 28.4±14.4 months showed complete closure in all cases but one, and continuous decrease of the pulmonary systolic pressure to 31.4±10.5 mmHg. No complications at follow-up have been reported. Conclusions: The Amplatzer Septal Occluder is a good alternative to percutaneously treat large and hypertensive ductus arteriosus.
Modern DIB Surveys and DIB Environmental Behavior
Authors: Sonnentrucker P.
Published: February 2014

Since the discovery of the Diffuse Interstellar Bands (DIBs) in the early 1920s, numerous research groups have taken on the task to obtain as complete a census of the DIBs as observationally possible in order to unravel characteristics that would allow the community to tie the DIB carriers to known species. Here, I will briefly review the efforts and progress that were made for the past two decades in producing new, deeper, and more complete DIB surveys. In particular, I will review the important role that these modern surveys are playing in revealing main observational characteristics of the DIBs and their dependence on the local physical conditions in the Galactic Interstellar Medium.
Diffuse Interstellar Bands: Families and Correlations
Authors: Krełowski J.
Published: February 2014

The term “families of diffuse bands” (DIBs) appeared in 1986/87 when my collaborators: Gordon A.H. Walker, Bengt E. Westerlund and I found that the strength ratio of the major DIBs 5780 and 5797 is heavily variable. We proved that at the same E(B-V) the DIB intensities may vary by as much as a factor of three or more. A similar result was published by Karl Josafatsson and Ted Snow soon after. A decade later, we proved (with Chris Sneden) that certain DIB strength ratios seem to be related to intensities of the known features of simple molecular species; this led to the introduction of the so called σ and ζ type interstellar clouds. The former are characterized by very weak molecular features (but broad DIBs – very strong) while the latter by rather strong bands of simple radicals and weak broad DIBs. Currently we face a bunch of questions: are the DIB intensities related to those of certain molecular species, e.g. C2 as suggested by Lew Hobbs' and Ted Snow's group? Do the DIB profiles, found to be complex by Peter Sarre, depend on e.g. the rotational temperatures of simple, linear carbon species? Do the DIB profiles depend on the irradiation of interstellar clouds by nearby stars? The relative DIB strengths as well as those of the simple radicals seem to be related to the shapes of interstellar extinction curves. We thus face three players in the interstellar translucent clouds: dust particles, simple radicals and the DIB carriers. Apparently, their mutual relations depend on local physical parameters of intervening clouds; these relations are not clear yet.
A Sensitive Spectral Survey of Interstellar Features in the Near-UV [3040-3700Å]
Authors: Bhatt N. H. , Cami J.
Published: February 2014

We present a comprehensive and sensitive unbiased survey of interstellar features in the near-UV range (3040-3700 Å). We combined a large number of VLT/UVES archival observations of a sample of highly reddened early type stars – typical diffuse interstellar band (DIB) targets. We stacked the individual observations to obtain a spectrum with a signal-to-noise ratio exceeding 1500. Careful inspection of this spectrum reveals tens of absorption features of interstellar nature, most of which can be identified with various atomic and molecular features. We furthermore detect four weak unidentified features, but we cannot establish their interstellar nature. Our sensitivity is limited by telluric and instrumental residuals; this precludes us from detecting broader features (e.g. DIBs). For each detected feature, we measured fundamental parameters (radial velocities, line widths, and equivalent widths). We also compare our co-added spectrum to cold gas-phase laboratory measurements of small, neutral polycyclic aromatic hydrocarbon (PAH) molecules.
Putting the Diffuse Interstellar Bands on the Map – Literally!
Authors: van Loon J. Th.
Published: February 2014

In a quest to further our understanding of the diffuse interstellar medium (ISM) as well as the unidentified carriers of the diffuse interstellar bands (DIBs), we are mapping DIBs across the sky using hundreds of hot stars as background torches – globular clusters (in particular ω Centauri), nearby stars in and around the Local Bubble, and stars within the Magellanic Clouds. I describe the results so far obtained and our current experiments.
A Possible New Sequence of DIBs
Authors: Bondar A. , Krełowski J.
Published: February 2014

One of the key factors in explaining nature of DIB carriers is to find regularities in their spectrum. Such a regular set of DIBs exists within interval λλ 6770–6865 Å. A possible new sequence of weak DIBs between λλ 5910–5990 Å is presented here. The new sequence is clearly visible in high resolution spectra (R ≳ 100,000) of some hot, reddened stars. Wavenumbers' differences, or spacings, between the most strong bands have values ~35, ~40 cm−1, which are very similar to those, found for DIBs near 6800 Å.
DIBs, Interstellar Dust, and Extinction
Authors: Clayton G. C.
Published: February 2014

The relationship between DIBs and dust is still unknown. The correlation between reddening and DIB strength means that the DIBs are mixed in with the dust and gas in interstellar clouds. The DIBs are relatively stronger in the diffuse interstellar medium than in dense clouds. There is only a weak correlation between the DIBs and the UV extinction parameters including the 2175 Å bump strength and the far-UV rise. In addition, the bump dust grains are sometimes polarized, while the DIBs are not. However, observations of DIBs in the SMC show that when the 2175 Å bump is weak or missing so are the DIBs. Two of the four sightlines that deviate strongly from the CCM UV extinction in the Galaxy show weak DIBs.
What Microwave Astronomical Spectroscopy can tell you about the Carriers of the DIBs
Authors: Liszt H. , Lucas R. , Pety J. , Gerin M.
Published: February 2014

Astronomical microwave spectroscopy has greatly broadened the inventory of identifiable chemical species in diffuse molecular gas and is an increasingly effective way to measure the abundances of polar molecules that may be candidate diffuse interstellar band carriers. Here we review some recent developments that hold new promise for chemical abundance determinations. We summarize and categorize the molecular inventory that has accrued in the past twenty years from microwave observations of diffuse clouds and we present summary tables of the molecular abundances within various chemical families in both dark and diffuse molecular gas.
Diffuse Interstellar Bands in (Proto-) Fullerene-Rich Environments
Authors: García-Hernández D. A.
Published: February 2014

The recent infrared detection of fullerenes (C60 and C70) in Planetary Nebulae (PNe) and R Coronae Borealis (RCB) stars offers a beautiful opportunity for studying the diffuse interstellar bands (DIBs) in sources where fullerenes are abundant. Here we present for the first time a detailed inspection of the optical spectra of the hot RCB star DY Cen and two fullerene PNe (Tc 1 and M 1-20), which permits us to directly explore the fullerenes - DIB connection. The DIB spectrum of DY Cen (García-Hernández et al. 2012a) is remarkably different from that in fullerene PNe (García-Hernández & Díaz-Luis 2013). In particular, Tc 1 displays unusually strong 4428 Å and 6309 Å DIBs, which are normal (or not seen) in DY Cen. On the other hand, DY Cen displays an unusually strong 6284 Å DIB that is found to be normal in fullerene PNe. We also report the detection of new broad and unidentified features centered at 4000 Å and 6525 Å in DY Cen and Tc 1, respectively. We suggest that the new 4000 Å band seen in DY Cen may be related to the circumstellar proto-fullerenes seen at infrared wavelengths (García-Hernández et al. 2012a). However, the intense 4428 Å DIB (probably also the 6309 Å DIB and the new 6525 Å band) may be related to the presence of larger fullerenes (e.g., C80, C240, C320, and C540) and buckyonions (multishell fullerenes such as C60@C240 and C60@C240@C540) in the circumstellar envelope of Tc 1 (García-Hernández & Díaz-Luis 2013).
Organic Nanoparticles as a Component of the Interstellar Medium
Authors: Kwok S.
Published: February 2014

Mixed aromatic/aliphatic organic nanoparticles (MAON) are suggested as the carrier of the unidentified infrared emission (UIE) features. The carriers of the diffuse interstellar bands (DIB) may be gas-phase molecular products released from MAON in the interstellar medium.
A Catalog of Diffuse Interstellar Bands in Fullerene-Containing Planetary Nebulae
Authors: Manchado A. , Díaz-Luis J. J. , García-Hernández D. A. , Cataldo F.
Published: February 2014

Large fullerenes and fullerene-based molecules have been proposed as carriers of diffuse interstellar bands (DIBs). The recent detection of the most common fullerenes (C60 and C70) around some Planetary Nebulae (PNe) now enable us to study the DIBs in fullerene-rich space environments. We have studied the presence of DIBs in the optical spectra (~3300-9400 Å) of two fullerene-containing PNe (Tc 1 and M 1-20). Special attention is given to DIBs which are found to be unusually intense in fullerene-containing PNe; several of these DIBS have not previously been reported. Fullerenes larger than C60 (and C70) and multishell fullerenes may be possible candidate carriers for the unusual DIBs seen in fullerene-rich environments.
A Novel Approach to the Detection and Characterization of PAH Cations and PAH-Photoproducts
Authors: Kokkin D. L. , Simon A. , Marshall C. , Bonnamy A. , Joblin C.
Published: February 2014

Cationic polycyclic aromatic hydrocarbons (PAHs) are attractive candidates for the Diffuse Interstellar Bands, but to date not a single PAH species has been identified on the basis of a spectral agreement. This indicates either that the molecular diversity is very large or that the candidates that have been considered are not the correct ones. In particular, small/medium-sized PAH cations are submitted to photodissociation under UV photons from stars. Therefore it is of interest to characterize the spectroscopic properties of key breakdown products. Furthermore, these studies should be performed under conditions that mimic those found in interstellar space, which leads to additional experimental difficulties. We describe the approach we are developing with the PIRENEA set-up and present results on the 1-Methylpyrene cation and photo-derived species. Experimental measurements are guided by calculations based on density functional theory.
Diffuse Cloud Models: Successes and Challenges
Authors: Roueff E. , Ruaud M. , Le Petit F. , Godard B. , Le Bourlot J.
Published: February 2014

We present the general physical conditions thought to be present in diffuse interstellar clouds. The radiation field is driving the atomic to molecular transition and the resulting physical conditions. We focus on the recent observational signatures of significant values of the cosmic ionization rate (10−16 - 10−15 s−1) which should also impact the clues to Diffuse interstellar Bands.
H2 as a Possible Carrier of the DIBs?
Authors: Ubachs W.
Published: February 2014

In the 1990s the hydrogen molecule, by far the most abundant molecular species in the interstellar medium, has been proposed as a possible carrier of the diffuse interstellar bands. While some remarkable coincidences were found in the rich spectrum of inter-Rydberg transitions of this molecule with DIB-features, both in frequency position as in linewidth, some open issues remained on a required non-linear optical pumping scheme that should explain the population of certain intermediate levels and act as a selection mechanism. Recently a similar scheme has been proposed relating the occurrence of the UV-bump (the ubiquitous 2170 Å extinction feature) to the spectrum of H2, therewith reviving the H2 hypothesis.
Composite Grains: Carriers of the Diffuse Interstellar Bands
Authors: Vaidya D. B. , Gupta R.
Published: February 2014

The dust grains flowing out of the stars are most likely non-spherical and inhomogeneous; viz. porous, fluffy and composites of many very small particles glued together. We calculate the scattering, absorption and extinction efficiencies of such composite grains. The composite grains consist of host silicate spheroid and inclusions of PAHs. We study the extinction as a function of the volume fraction of the inclusions. In particular, we study the variation in the absorption peak, at the wavelength ‘4430Å’ with the volume fraction of the PAH inclusions. We present the composite grain models and discuss the results.
A chiral spin crossover metal–organic framework
Authors: Liu Wei , Bao Xin , Mao Ling-Ling , Tucek Jiri , Zboril Radek , Liu Jun-Liang , Guo Fu-Sheng , Ni Zhao-Ping , Tong Ming-Liang
Published: February 2014

A rare chiral spin crossover metal–organic framework, [FeII(mptpy)2]·solv, has been solvothermally synthesized through spontaneous resolution.
Synthesis, antiradical activity and in vitro cytotoxicity of novel organotin complexes based on 2,6-di-tert-butyl-4-mercaptophenol
Authors: Shpakovsky D. B. , Banti C. N. , Mukhatova E. M. , Gracheva Yu. A. , Osipova V. P. , Berberova N. T. , Albov D. V. , Antonenko T. A. , Aslanov L. A. , Milaeva E. R. , Hadjikakou S. K.
Published: February 2014

The antiradical activity and in vitro cytotoxicity of novel organotin complexes with 2,6-di-tert-butylphenol pendant were established.
Methodologies for the analysis of instantaneous lipid diffusion in md simulations of large membrane systems
Authors: Chavent Matthieu , Reddy Tyler , Goose Joseph , Dahl Anna Caroline E. , Stone John E. , Jobard Bruno , Sansom Mark S. P.
Published: February 2014

Interactions between lipids and membrane proteins play a key role in determining the nanoscale dynamic and structural properties of biological membranes. Molecular dynamics (MD) simulations provide a valuable tool for studying membrane models, complementing experimental approaches. It is now possible to simulate large membrane systems, such as simplified models of bacterial and viral envelope membranes. Consequently, there is a pressing need to develop tools to visualize and quantify the dynamics of these immense systems, which typically comprise millions of particles. To tackle this issue, we have developed visual and quantitative analyses of molecular positions and their velocity field using path line, vector field and streamline techniques. This allows us to highlight large, transient flow-like movements of lipids and to better understand crowding within the lipid bilayer. The current study focuses on visualization and analysis of lipid dynamics. However, the methods are flexible and can be readily applied toe.g.proteins and nanoparticles within large complex membranes. The protocols developed here are readily accessible both as a plugin for the molecular visualization program VMD and as a module for the MDAnalysis library.
Water and methanol adsorption on MOFs for cycling heat transformation processes
Authors: Jeremias Felix , Fröhlich Dominik , Janiak Christoph , Henninger Stefan K.
Published: February 2014

MOFs with high water uptake capacity and hydrothermal stability are gaining attention for low temperature heat transformation applications such as thermally driven adsorption chillers or adsorption heat pumps.
A non-photochemical route to synthesize simple benzo[1,2-b:4,3-b′]dithiophenes: FeCl3-mediated cyclization of dithienyl ethenes
Authors: Cauteruccio Silvia , Dova Davide , Graiff Claudia , Carrara Claudio , Doulcet Julien , Stephenson G. Richard , Licandro Emanuela
Published: February 2014

The FeCl3-mediated cyclization of α,α′-disubstituted Z-alkenes as a general and non-photochemical route to synthesize benzo[1,2-b:4,3-b′]dithiophene derivatives.
Precursor directed synthesis – “molecular” mechanisms in the Soft Chemistry approaches and their use for template-free synthesis of metal, metal oxide and metal chalcogenide nanoparticles and nanostructures
Authors: Seisenbaeva Gulaim A. , Kessler Vadim G.
Published: February 2014

This review summarizes basic principles in the mechanisms of Soft Chemistry synthesis giving access to nanoparticles and nanostructures with controlled architecture, morphology and composition.
Strongly coupled hybrid nanostructures for selective hydrogen detection – understanding the role of noble metals in reducing cross-sensitivity
Authors: Liu Bin , Cai Daoping , Liu Yuan , Wang Dandan , Wang Lingling , Xie Wuyuan , Li Qiuhong , Wang Taihong
Published: February 2014

New insights into the cross-sensitivity of gas sensors are provided based on experimental and DFT calculation results. Compared with traditional thermally activated sensors, the sensor based on the hybrid nanostructures exhibits high response and excellent selectivity towards hydrogen.
Reversible thermal-mode control of luminescence from liquid-crystalline gold(i) complexes
Authors: Fujisawa Kaori , Okuda Yuki , Izumi Yuichi , Nagamatsu Akira , Rokusha Yuki , Sadaike Yusuke , Tsutsumi Osamu
Published: February 2014

Thermal-mode switching of the intensity and colour of photoluminescence from liquid-crystalline Au complexes was reversibly induced by a phase transition.
A benzothiazole–cyclopentadithiophene bridged D–A–π–A sensitizer with enhanced light absorption for high efficiency dye-sensitized solar cells
Authors: Wang Xingzhu , Yang Jing , Yu Hao , Li Feng , Fan Li , Sun Wen , Liu Yeru , Koh Zhen Yu , Pan Jiahong , Yim Wai-Leung , Yan Lei , Wang Qing
Published: February 2014

We demonstrate a D–A–π–A sensitizer with a benzothiazole–cyclopentadithiophene moiety as the spacer in a triphenylamine dye for dye-sensitized solar cells. The dye has a broad light absorption range up to 800 nm. A power conversion efficiency >9% has been achieved using a [Co(bpy)3]2+/3+-based electrolyte.
Central-transition double-quantum sideband NMR spectroscopy of half-integer quadrupolar nuclei: estimating internuclear distances and probing clusters within multi-spin networks
Authors: Brinkmann Andreas , Edén Mattias
Published: February 2014

Clusters within quadrupolar spin networks are probed and internuclear distances between quadrupolar nuclei are estimated by central-transition double-quantum sideband NMR spectroscopy.
Molecules in the mirror: how SERS backgrounds arise from the quantum method of images
Authors: Barnett Stephen M. , Harris Nadine , Baumberg Jeremy J.
Published: February 2014

The SERS background can be derived from the interaction of a molecule near a plasmonic surface with its image molecule.
Infrared spectroscopy of large-sized neutral and protonated ammonia clusters
Authors: Katada Marusu , Shishido Ryunosuke , Fujii Asuka
Published: February 2014

Size selective IR spectroscopy shows the nature of hydrogen bond networks in neutral and protonated ammonia clusters.
High performance photoelectrochemical hydrogen generation and solar cells with a double type II heterojunction
Authors: Lai Lai-Hung , Gomulya Widianta , Protesescu Loredana , Kovalenko Maksym V. , Loi Maria A.
Published: February 2014

We report on the fabrication of CdSe quantum dot (QD) sensitized electrodes by direct adsorption of colloidal QDs on mesoporous TiO2followed by 3-mercaptopropionic acid (MPA) ligand exchange.
Synthesis and characterisation of a new anion exchangeable layered hydroxyiodide
Authors: Southworth Faye Y. , Wilson Claire , Coles Simon J. , Fogg Andrew M.
Published: February 2014

A new anion exchangeable lanthanide hydroxyiodide has been synthesised, structurally characterised and its anion exchange chemistry investigated.
Rare-earth alkyl complexes supported by formamidinate ligands: synthesis, structure, and catalytic activity for isoprene polymerization
Authors: Guo Liping , Zhu Xiancui , Zhou Shuangliu , Mu Xiaolong , Wei Yun , Wang Shaowu , Feng Zhijun , Zhang Guangchao , Deng Baojia
Published: February 2014

Monoalkyl rare-earth metal complexes could be highly active catalysts for 1,4-regioselective polymerization of isoprene in the presence of cocatalysts.
Utility of tris(4-bromopyridyl) europium complexes as versatile intermediates in the divergent synthesis of emissive chiral probes
Authors: Butler Stephen J. , Delbianco Martina , Evans Nicholas H. , Frawley Andrew T. , Pal Robert , Parker David , Puckrin Robert S. , Yufit Dmitry S.
Published: February 2014

The tribromopyridyl complex is a versatile late intermediate in the divergent synthesis of emissive triazole and aryl–alkynyl substituted complexes.
Microwave assisted extraction as an important technology for valorising orange waste
Authors: Attard Thomas M. , Watterson Baillie , Budarin Vitaliy L. , Clark James H. , Hunt Andrew J.
Published: February 2014

Kinetics of microwave-assistedd-limonene extraction demonstrates a five-fold increase in yield over conventional extraction in a two stage process.
Halide ion-mediated growth of single crystalline Fe nanoparticles
Authors: Zhang Sen , Jiang Guangming , Filsinger Gabriel T. , Wu Liheng , Zhu Huiyuan , Lee Jonghun , Wu Zhongbiao , Sun Shouheng
Published: February 2014

We report a facile halide ion (Cl− or Br−) mediated synthesis of Fe nanoparticles (NPs) by thermal decomposition of Fe(CO)5.
Graphene nanoribbon blends with P3HT for organic electronics
Authors: El Gemayel Mirella , Narita Akimitsu , Dössel Lukas F. , Sundaram Ravi S. , Kiersnowski Adam , Pisula Wojciech , Hansen Michael Ryan , Ferrari Andrea C. , Orgiu Emanuele , Feng Xinliang , Müllen Klaus , Samorì Paolo
Published: February 2014

Solution processed 18 arm-chair graphene nanoribbons embedded in a matrix of regioregular poly(3-hexylthiophene) show improved photoconductivity and field-effect transistor performance.
An electrochemically grown three-dimensional porous Si@Ni inverse opal structure for high-performance Li ion battery anodes
Authors: Kim Do Youb , Suk Jungdon , Kim Dong Wook , Kang Yongku , Im Sang Hyuk , Yang Youngjo , Park O Ok
Published: February 2014

A Si@Ni inverse opal structure fabricated by using an inexpensive electrodeposition method and a colloidal crystal template exhibits high capacity, cyclability, and rate-performance as an anode for Li ion batteries.
Understanding doping anomalies in degenerate p-type semiconductor LaCuOSe
Authors: Scanlon David O. , Buckeridge John , Catlow C. Richard A. , Watson Graeme W.
Published: February 2014

Using state-of-the-art hybrid DFT calculations we explain the defect chemistry of LaCuOSe, a poorly understood wide band gap p-type conductor.
The upstream conserved regions (UCRs) mediate homo- and hetero-oligomerization of type 4 cyclic nucleotide phosphodiesterases (PDE4s)
Authors: Xie Moses , Blackman Brigitte , Scheitrum Colleen , Mika Delphine , Blanchard Elise , Lei Tao , Conti Marco , Richter Wito
Published: February 2014

PDE4s (type 4 cyclic nucleotide phosphodiesterases) are divided into long and short forms by the presence or absence of conserved N-terminal domains termed UCRs (upstream conserved regions). We have shown previously that PDE4D2, a short variant, is a monomer, whereas PDE4D3, a long variant, is a dimer. In the present study, we have determined the apparent molecular masses of various long and short PDE4 variants by size-exclusion chromatography and sucrose density-gradient centrifugation. Our results indicate that dimerization is a conserved property of all long PDE4 forms, whereas short forms are monomers. Dimerization is mediated by the UCR domains. Given their high sequence conservation, the UCR domains mediate not only homo-oligomerization, but also hetero-oligomerization of distinct PDE4 long forms as detected by co-immunoprecipitation assays and FRET microscopy. Endogenous PDE4 hetero-oligomers are, however, low in abundance compared with homo-dimers, revealing the presence of mechanisms that predispose PDE4s towards homo-oligomerization. Oligomerization is a prerequisite for the regulatory properties of the PDE4 long forms, such as their PKA (protein kinase A)-dependent activation, but is not necessary for PDE4 protein–protein interactions. As a result, individual PDE4 protomers may independently mediate protein–protein interactions, providing a mechanism whereby PDE4s contribute to the assembly of macromolecular signalling complexes.
Fast seismic data compression based on high‐efficiency SPIHT
Authors: Xie Kai , Bai Zhijun , Yu Wenmao
Published: February 2014

Based on the set positioning in hierarchical tree (SPIHT) algorithm, fast seismic data compression based on the high‐efficiency SPIHT (HESPIHT) algorithm is presented. To verify the validity of the algorithm, 10 seismic cross‐sections are selected for the experiment. The result shows that the algorithm can reserve the quality of data better, meanwhile improving the efficiency of encoding and decoding.
Mechanical properties of tetra-PEG gels with supercoiled network structure
Authors: Katashima Takuya , Asai Makoto , Urayama Kenji , Chung Ung-il , Sakai Takamasa
Published: February 2014

We investigate the effects of swelling and deswelling on the mechanical properties of tetra-polyethylene glycol gels with the precisely tuned polymerization degree of network strand (Nc) and polymer volume fraction at preparation (ϕ0) by varying the fraction of interest (ϕm). The ϕm-dependence of the elastic modulus exhibits a crossover at ϕc due to large contraction of the network strands (supercoiling) accompanying deswelling. The Obukhov model successfully describes the ϕm-dependence of the elastic modulus. We estimate the fractal dimension of network strands (Df) by analyzing the stress-elongation relationships at high stretching using Pincus blob concept. In the supercoiling region, Df increases with an increase in ϕm, which suggests that the gyration radius of network strands decreases with deswelling in affine manner. The extensibility increases with an increase in ϕm because the deswelling reduces the distance between the neighboring junctions. These findings will help to understand the structure and formation mechanism of supercoiling.
Gradient magnetic binary alloy nanowire
Authors: Zeng Min , Yang Haozhe , Liu Jue , Yu Ronghai
Published: February 2014

CoNi gradient binary-alloy nanowires are prepared in porous anodic aluminum oxide (AAO) template via electrodeposition. The coercivity and remanence of the nanowires are of high anisotropy due to the axial deposition of the magnetic compositions. The magnetocrystalline anisotropy and crystalline structure of the nanowires show dependence on the treatment of the annealing process that may reduce the anisotropy and improve the squareness. The difference in intensity of the effective anisotropic field with easy magnetization direction along the wire axis is responsible for different variation of the magnetic properties which is dominated by the competition between shape anisotropy and magnetocrystalline anisotropy.
Adaptive sparse grid expansions of the vibrational Hamiltonian
Authors: Strobusch D. , Scheurer Ch.
Published: February 2014

The vibrational Hamiltonian involves two high dimensional operators, the kinetic energy operator (KEO), and the potential energy surface (PES). Both must be approximated for systems involving more than a few atoms. Adaptive approximation schemes are not only superior to truncated Taylor or many-body expansions (MBE), they also allow for error estimates, and thus operators of predefined precision. To this end, modified sparse grids (SG) are developed that can be combined with adaptive MBEs. This MBE/SG hybrid approach yields a unified, fully adaptive representation of the KEO and the PES. Refinement criteria, based on the vibrational self-consistent field (VSCF) and vibrational configuration interaction (VCI) methods, are presented. The combination of the adaptive MBE/SG approach and the VSCF plus VCI methods yields a black box like procedure to compute accurate vibrational spectra. This is demonstrated on a test set of molecules, comprising water, formaldehyde, methanimine, and ethylene. The test set is first employed to prove convergence for semi-empirical PM3-PESs and subsequently to compute accurate vibrational spectra from CCSD(T)-PESs that agree well with experimental values.
Production of a high-velocity water slug using an impacting technique
Authors: Dehkhoda S. , Bourne N. K.
Published: February 2014

A pulsed water jet consists of a series of discrete water slugs travelling at high velocity. Immediately after striking a target, these slugs apply high-intensity, short-duration transient stress pulses reaching an amplitude known as the water hammer pressure, followed by low-intensity, long-duration stationary stress at a lower stagnation pressure. The magnitude and duration of the water hammer and stagnation pressures are controlled by the size and quality of the water slugs. The use of water jets for rock cutting in mining operations is a centuries-old technology; however, practical methods for producing high-energy water slugs repeatedly have proven difficult. This can be partly due to the fact that the geometrical properties of a jet and so its effectiveness in creating damage is controlled and influenced by the method that is employed to generate the water slugs. This paper investigates the quality of a single water slug produced using an impacting technique where a hammer strikes a piston, resting on top of a water-filled chamber. The coherence and integrity of the jet core was of concern in this study. The impact impulse of the formed water jet was measured in a Kel-F target material using an embedded PVDF (Polyvinylidene fluoride) shock gauge. The recorded stress waveform was then used to determine the unity and endurance of the water slug stream once travelled through air.
Cooking rice with minimum energy
Authors: De Dilip Kumar , Nathaniel Muwa , Nath De Narendra , Ajaeroh Ikechukwu Mathais
Published: February 2014

Detailed experimental studies on procedures of reducing “On-stove time” and cooking with minimum Energy (Heat) using new energy efficient cooking techniques have been carried out. The total minimum amount of heat, Qm (after subtracting radiation losses), to be delivered to the pot, the sensible heat required for cooking, hs, and on-stove time t1 required to cook 1 kg of dry rice, using a new technique (Technique I) of cooking with a stove of effective power, Peff, 626 ± 10 W are found as 560 ± 6 kJ, 465 ± 5 kJ, and 911 ± 10 s, respectively; while conventional method with pressure cooker (Technique II) required Qm = 824 ± 10 kJ heat and 1357 ± 16 s on-stove time. The corresponding energy and time without a pressure cooker (Technique III) were 1.5 MJ and 2640 s, respectively. When compared with other published works, our method gives the lowest energy to cook 1 kg of dry rice. The efficiencies of the cooking method for different techniques are evaluated. The Clean Development Mechanism potentials of the new cooking method are also evaluated. The results obtained are expected to help develop new cooking apparatus to cook with the lowest amount of energy and thus conserve food nutrient energy and protect environment by minimizing CO2 and other toxic emissions associated with all kinds of stoves/ovens. Discussion is made how to apply Technique I in solar cooker to reduce the cooking time.
Stoichiometry effect on Cu2ZnSnS4 thin films morphological and optical properties
Authors: Malerba Claudia , Azanza Ricardo Cristy Leonor , Valentini Matteo , Biccari Francesco , Müller Melanie , Rebuffi Luca , Esposito Emilia , Mangiapane Pietro , Scardi Paolo , Mittiga Alberto
Published: February 2014

Thin films of Cu2ZnSnS4 (CZTS) were prepared by sulfurization of multilayered precursors of ZnS, Cu, and Sn, changing the relative amounts to obtain CZTS layers with different compositions. X-Ray Diffraction (XRD), Energy Dispersive X-Ray spectroscopy, and SEM were used for structural, compositional, and morphological analyses, respectively. XRD quantitative phase analysis provides the amount of spurious phases and information on Sn-site occupancy. The optical properties were investigated by spectrophotometric measurements and Photothermal Deflection Spectroscopy. These films show a clear dependence of the optical and microstructural properties on the tin content. As the tin content increases we found: (i) an increase in both crystalline domain and grain size, (ii) an abrupt increase of the energy gap of about 150 meV, from 1.48 to 1.63 eV, and (iii) a decrease of sub-gap absorption up to two orders of magnitude. The results are interpreted assuming the formation of additional defects as the tin content is reduced.
Tunneling electron induced chemisorption of copper phthalocyanine molecules on the Cu(111) surface
Authors: Stock T. , Nogami J.
Published: February 2014

The adsorption of up to one monolayer (ML) of copper phthalocyanine (CuPc) molecules on a room temperature Cu(111) surface has been studied using scanning tunneling microscopy (STM). Below 1 ML the molecules are in a fluid state and are highly mobile on the surface. At 1 ML coverage the molecules coalesce into a highly ordered 2D crystal phase. At sub-ML coverages, chemisorption of individual CuPc molecules can be induced through exposure to tunneling electrons at a tunneling bias voltage exceeding a threshold value. This tunneling electron induced effect has been exploited to perform molecular STM lithography.
Phonons with long mean free paths in a-Si and a-Ge
Authors: Zhan Tianzhuo , Xu Yibin , Goto Masahiro , Tanaka Yoshihisa , Kato Ryozo , Sasaki Michiko , Kagawa Yutaka
Published: February 2014

We investigated phonons with long mean free paths (MFPs) in amorphous Si (a-Si) and amorphous Ge (a-Ge). The thermal conductivity of a-Si and a-Ge thin films prepared by magnetron sputtering was found to depend on film thickness and deposition temperature. From the film thickness dependence, we conclude that phonons with MFPs longer than 100 nm contribute to heat transport in a-Si and a-Ge. Also, as deposition temperature was increased, phonons with MFPs ranging from 100 to 250 nm in a-Si and from 15 to 250 nm in a-Ge increased.
Peptidoglycan-binding protein TsaP functions in surface assembly of type IV pili
Authors: Siewering Katja , Jain Samta , Friedrich Carmen , Webber-Birungi Mariam T. , Semchonok Dmitry A. , Binzen Ina , Wagner Alexander , Huntley Stuart , Kahnt Jörg , Klingl Andreas , Boekema Egbert J. , Søgaard-Andersen Lotte , van der Does Chris
Published: February 2014

Significance

Type IV pili (T4P) are ubiquitous and versatile bacterial cell surface structures involved in different processes like adhesion to host cells, biofilm formation, motility, and DNA uptake. T4P play an important role in the pathogenesis of many bacteria. We identify a protein whose presence in bacterial genomes is strongly linked to the presence of T4P systems and that is involved in the surface assembly of T4P. TsaP, the T4P secretin-associated protein is proposed to anchor the outer membrane secretin complex to the peptidoglycan and/or to align the secretin to inner membrane components.
Encoding regulatory state boundaries in the pregastrular oral ectoderm of the sea urchin embryo
Authors: Li Enhu , Cui Miao , Peter Isabelle S. , Davidson Eric H.
Published: February 2014

Significance

Regulatory state boundary formation is a general process in early development, in which embryonic territory is divided up into spatial domains that express distinct sets of regulatory genes. We establish the mechanistic principles by which multiple orthogonal boundaries of this kind are progressively formed on the oral side of the sea urchin embryo, according to an encoded genomic program. These boundaries separate prospective endoderm from ectoderm domains, neurogenic from non-neurogenic domains, and ciliated band from oral ectoderm domains and produce an orthogonal grid of regulatory states. Boundary formation invariably depends on spatial transcriptional repression superimposed on more widespread domains of transcriptional activation.
The Great American Scaffold
Authors: Austermühl Frank
Published: February 2014

Based on extensive quantitative and qualitative analyses of a corpus of American presidential speeches that includes all inaugural addresses and State of the Union messages from 1789 to 2008, as well as major foreign and security policy speeches after 1945, this research monograph analyzes the various forms and functions of intertextual references found in the discourse of American presidents. Working within an original, interdisciplinary theoretical framework established by theories of intertextuality, discourse analysis, and presidential studies, the book discusses five different types of presidential intertextuality, all of which contribute jointly to creating a set of carefully manipulated and politically powerful images of both the American nation and the American presidency. The book is intended for scholars and students in political and presidential studies, communications, American cultural studies, and linguistics, as well as anyone interested in the American presidency in general.
Economic migrants, social networks, and the prospect of koinéization in the United Arab Emirates
Authors: Boyle Ronald
Published: February 2014

In the United Arab Emirates (UAE), immigrants constitute nearly 90% of the population. Most are adults who come from South Asia and who are ESL users of English. The paper suggests that the English speaking community in the UAE is at the stage of pre-koinéization, one in which there is an increase in transparency with regard to features which are overly complex for ESL speakers. The very small number of children in the immigrant community and the instability of the community are constraints on the process of pre-koinéization, but this paper nevertheless suggests that there are users of acrolectal English who strive for greater transparency, and it provides examples of three ways in which they are doing so. These are through the extension of verb complementation patterns, the extension of patterns of transitivity, and the extension of the pluralization of nouns, and these changes are well documented in postcolonial Englishes (Schneider 2007). The data are drawn from a corpus of 3.3 million words of acrolectal written English.
An 18th-century novel from the Miskito Coast
Authors: Holm John
Published: February 2014

William Williams (1727–1791) wrote a novel entitled Mr. Penrose: The Journal of Penrose, Seaman about an English sailor marooned on the Caribbean coast of Nicaragua, partly based on the author’s own experience. Internal linguistic evidence confirms that the castaway’s contact was with the Rama and Miskito Indians of this area. The novel’s 350 printed pages are in the formal English of the times, but also include dialogue in the local vernacular English that was still undergoing creolization. It includes words not only from Rama and Miskito, but also Spanish and African languages and phrases suggesting convergence with modern English Creole structures (“Harry was sick, sick”). This article uses lexical and morphosyntactic data from the 18th-century manuscript to cast light on the origin of synchronic features of Miskito Coast Creole English.
Arabic plurals and root and pattern morphology in Palestinian and Egyptian heritage speakers
Authors: Benmamoun Elabbas , Albirini Abdulkafi , Montrul Silvina , Saadah Eman
Published: February 2014

This study investigates heritage speakers’ knowledge of plural formation in their colloquial varieties of Arabic, which use both concatenative and non-concatentative modes of derivation. In the concatenative derivation, a plural suffix attaches to the singular stem (muhandis‘engineer-sg.’ →muhandis-iin‘engineer-pl’); in the non-concatenative, the relation between the singular (gamal‘camel’) and the plural (gimaal‘camels’) typically involves vocalic and prosodic alternations with the main shared similarity between the two forms being the consonantal root (e.g., g-m-l). In linguistic approaches, non-concatenative patterns have been captured in different ways, though the earliest and most recognizable approach involves the mapping of a consonantal root onto a plural template. We investigated heritage speakers’ knowledge of the root and pattern system in two independent experiments. In Experiment 1, oral narratives were elicited from 20 heritage speakers and 20 native speakers of Egyptian and Palestinian Arabic. In Experiment 2, another group of 24 heritage speakers and 24 native speakers of the same dialects completed an oral picture-description task. The results of the two experiments show that heritage speakers’ knowledge of the root and pattern system of Arabic is not target-like. Yet, they have a good grasp of the root and template as basic units of word formation in their heritage Arabic dialects. We discuss implications for debates about the acquisition of the root and pattern system of Arabic morphology.
IRIS: A new resource for second language research
Authors: Marsden Emma , Mackey Alison
Published: February 2014

IRIS is a digital database of materials used to collect data for second language research that went fully live in August 2012. At the time of writing (May 2013), there have been over 3,300 downloads of materials held on the site, and almost 11,000 visits, demonstrating a clear need for the resource. IRIS has the potential to make a step-change in the way our field works, impacting the nature and rate of second language (L2) research. Here we outline the motivations for the project, what the IRIS database consists of, how it is structured, and the future of the resource.
Personalisation in Mass Media Communication
Authors: Landert Daniela
Published: February 2014

It seems to be a truism that today’s news media present the news in a more personal and direct way than print newspapers some twenty-five years ago. However, it is far from obvious, how this can be described linguistically. This study develops a model that integrates and differentiates between the various facets of personalisation from a linguistic point of view. It includes 1) contexts that involve the audience by inviting direct interaction and through the use of visual elements; 2) the focus on private individuals who are personally affected by news events; and 3) the use of communicative immediacy, for instance in the form of direct speech and first and second person pronouns. This model is applied to data from five British online news sites, demonstrating how individual features contribute to personalisation, how different features interact, and what personalisation strategies are used by news sites of different market orientations.