bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic absorption and phosphorescence of cyanodiacetylene
Authors: Turowski Michał , Crépin Claudine , Gronowski Marcin , Guillemin Jean-Claude , Coupeaud Anne , Couturier-Tamburelli Isabelle , Piétri Nathalie , Kołos Robert
Published: August 2010

Electronic absorption and emission spectra have been investigated for cyanodiacetylene, HC5N, an astrophysically relevant molecule. The analysis of gas-phase absorption was assisted with the parallel rare gas matrix isolation experiments and with density functional theory (DFT) predictions concerning the excited electronic states. Mid-UV systems B̃ Δ1←X̃ Σ1+ (origin at 282.5 nm) and Ã Σ1−←X̃ Σ1+ (306.8 nm) were observed. Vibronic assignments have been facilitated by the discovery of the visible phosphorescence ã Σ3+←X̃ Σ1+ in solid Ar, Kr, and Xe. Phosphorescence excitation spectra, as well as UV absorption measurements in rare gas matrices, revealed the enhancement of Ã←X̃ transitions. The vibronic structure of dispersed phosphorescence spectra supplied new data concerning the ground state bending fundamentals of matrix-isolated HC5N. The experimental singlet-triplet splitting, 2.92 eV in Ar, closely matches the value of 3.0 eV predicted by DFT.
Modeling of transport phenomena during the coaxial laser direct deposition process
Authors: Wen Shaoyi , Shin Yung C.
Published: August 2010

Laser direct deposition is widely used for rapid freeform fabrication of fully dense components with good metallurgical properties directly from computer-aided design drawings. Because of complex physics involved such as laser powder interaction, laser substrate interaction, track interface evolution, and melt-solid interaction, it is important to develop simulation models to better understand the characteristics and mechanisms in the process so that optimization and control of a laser direct deposition process are possible. In this paper, a new comprehensive three-dimensional self-consistent transient model is presented for a coaxial laser direct deposition process, which considers physical behaviors such as laser particle interaction, mass addition, heat transfer, fluid flow, melting, and solidification. A continuum model is built to deal with different phases (gas, liquid, solid, and mushy zone) in the calculation domain. An improved level-set method, which takes the conservative form while being implicitly solved with other governing equations, is proposed to track the evolution of free liquid/gas interface during the deposition process. To make the model more physically complete than those in the literature, a newly derived mass source term, which considers the rate of the gas phase being replaced by the deposited material due to the moving interface in some control volumes, is incorporated into the continuity equation. Corresponding new source terms of enthalpy and momentum due to the moving interface are also derived and embedded in the energy and momentum equations. The governing equations are discretized using the finite volume approach to better predict the fluid motion mainly driven by capillary and thermocapillary forces. The simulated track heights, widths, molten pool depths, and track profiles agree well with the experimental results.
Identification of pre-breakdown mechanism of silicon solar cells at low reverse voltages
Authors: Lausch Dominik , Petter Kai , Bakowskie Ronny , Czekalla Christian , Lenzner Jörg , von Wenckstern Holger , Grundmann Marius
Published: August 2010

The local breakdown of commercial silicon solar cells occurring at reverse voltages of only 3–4 V has been investigated by means of current-voltage measurements, dark lock-in thermography, and reverse-biased electroluminescence (ReBEL) with a spatial resolution on the micrometer-scale. It is shown that the origin of the local breakdown (so-called type I) can be traced back to a contamination of the wafer surface with Al particles prior to the phosphorous diffusion step. A model is presented explaining that the spectral maximum of ReBEL is within the visible range.
Maximizing the open-circuit voltage of polymer: Fullerene solar cells
Authors: Bijleveld J. C. , Verstrijden R. A. M. , Wienk M. M. , Janssen R. A. J.
Published: August 2010

The open-circuit voltage (Voc) of bulk heterojunction solar cells based on polymers and fullerene derivatives is limited to ∼1.15 V by the optical band gap of the fullerene of ∼1.75 eV and the required 0.6 eV offset for efficient charge generation. In practice this limit has not yet been reached. We present a semiconducting polymer that gives Voc=1.15 V. To reach this value the surface of the hole collecting electrode is modified by UV-ozone, which increases the work function and creates an Ohmic contact. Under simulated AM1.5 conditions optimized cells provide a power conversion efficiency of ∼1%.
In situ ultraviolet photoemission spectroscopy measurement of the pentacene-RuO2/Ti contact energy structure
Authors: Yun Dong-Jin , Lee Seunghyup , Yong Kijung , Rhee Shi-Woo
Published: August 2010

In situ ultraviolet photoemission spectroscopy was used during the pentacene layer growth on ruthenium and ruthenium oxide films to measure the energy barrier in the metal-semiconductor contact. The measurement showed that ruthenium oxide film formed lower hole-injection barrier with pentacene than ruthenium or gold metal film due to its high work function of 4.92 eV and low resistivity of ∼350 μΩ cm. Pentacene thin film transistor with ruthenium oxide electrode showed higher mobility of 0.435 cm2/V s and on-off ratio of 106 than ruthenium (μ: 0.205 cm2/V s, on/off ratio: 106) or gold electrode (μ: 0.338 cm2/V s, on/off ratio: 106) of the same structure.
CdS
/
Cu
(
In
,
Ga
)
Se
2
interface formation in high-efficiency thin film solar cells
Authors: Pookpanratana S. , Repins I. , Bär M. , Weinhardt L. , Zhang Y. , Félix R. , Blum M. , Yang W. , Heske C.
Published: August 2010

The evolution of the CdS/Cu(In,Ga)Se2 interface in high-efficiency thin film solar cells was monitored by chemically sensitive x-ray emission spectroscopy as a function of CdS chemical bath deposition time. We find direct experimental evidence that, in the initial deposition steps, the sulfur atoms on the Cu(In,Ga)Se2 surface exist in at least two distinct chemical environments, namely CdS and a compound involving Ga and In. The findings indicate the complexity of the CdS/Cu(In,Ga)Se2 interface structure at the atomic scale.
Impact of nitrogen incorporation on pseudomorphic site-controlled quantum dots grown by metalorganic vapor phase epitaxy
Authors: Dimastrodonato V. , Mereni L. O. , Juska G. , Pelucchi E.
Published: August 2010

We report on some surprising optical properties of diluted nitride InGaAs1−εNε/GaAs (ε⪡1) pyramidal site-controlled quantum dots, grown by metalorganic vapor phase epitaxy on patterned GaAs (111)B substrates. Microphotoluminescence characterizations showed antibinding exciton/biexciton behavior, a spread of exciton lifetimes in an otherwise very uniform sample, with unexpected long neutral exciton lifetimes (up to 7 ns) and a nearly zero fine structure splitting on a majority of dots.
Tailoring point electron sources of individual carbon nanotubes
Authors: Lin Yung-Chang , Wu Cheng-Da , Chiu Po-Wen
Published: August 2010

We describe a technique for the fabrication of individual carbon nanotube electron field emitters on silicon substrates, with well-defined tunneling geometries and robust metal contacts. The suspended nanotube emitters have been produced by edge lithography on cleaved silicon substrate in conjunction with edge etching. The I–V curves acquired from the resulting emitters followed the Fowler–Nordheim law and exhibited a low operating voltage in a short cathode-anode distance. The extracted field enhancement factors were an order of magnitude higher than those obtained in an electron microscope but in good agreement with those reported in large-area measurements.
Tunnel magnetoresistance and spin torque switching in MgO-based magnetic tunnel junctions with a Co/Ni multilayer electrode
Authors: Moriyama Takahiro , Gudmundsen Theodore J. , Huang Pinshane Y. , Liu Luqiao , Muller David A. , Ralph Daniel C. , Buhrman Robert A.
Published: August 2010

We have fabricated MgO-barrier magnetic tunnel junctions with a Co/Ni switching layer to reduce the demagnetizing field via interface anisotropy. With a fcc-(111) oriented Co/Ni multilayer combined with an FeCoB insertion layer, the demagnetizing field is 2 kOe and the tunnel magnetoresistance can be as high as 106%. Room-temperature measurements of spin-torque switching are in good agreement with predictions for a reduced critical current associated with the small demagnetization for antiparallel-to-parallel switching. For parallel-to-antiparallel switching the small demagnetization field causes spatially nonuniform reversal nucleated at the sample ends, with a low energy barrier but a higher switching current.
Polarization from dielectric-barrier discharges in ferroelectrets: Mapping of the electric-field profiles by means of thermal-pulse tomography
Authors: Qiu Xunlin , Holländer Lars , Suárez Rosaura Flores , Wirges Werner , Gerhard Reimund
Published: August 2010

A polymer-ferroelectret system is fabricated by attaching two uniform polycarbonate films to a grid produced from double-sided adhesive tape by means of computer-controlled laser cutting. The openings of the grid structure result in well-defined voids inside the three-layer system, which can be internally charged through dielectric barrier discharges. The negatively charged internal void surfaces can be made visible by means of xerographical toner, and the electric-field distribution inside such ferroelectrets can be studied with thermal-pulse tomography. Both techniques exhibit polarization patterns that are consistent with the grid structure. Possible reasons for the observed non-uniform charge distributions are discussed.
High temperature electrical conduction in nanoscale hafnia films under varying oxygen partial pressure
Authors: Ko Changhyun , Shandalov Michael , McIntyre Paul C. , Ramanathan Shriram
Published: August 2010

Point defect equilibration in nanocrystalline hafnium oxide thin films in the monoclinic (m-HfO2) phase was studied by electrochemical measurements performed under varying temperature and oxygen partial pressure (PO2) on films of 35–63 nm thickness on single crystal MgO and Al2O3 substrates. The conductance varied as (PO2)n, where n is the in the range ∼+1/11 to ∼+1/14, at high PO2. The increasing conductance with PO2 suggests that the electronic conduction in the HfO2 films is p-type and oxygen interstitials or hafnium vacancies, rather than oxygen vacancies, could be dominant charged point defects in nanocrystalline, undoped m-HfO2 films.
Nonthermal and screening effects on the Thomson scattering in Lorentzian plasmas
Authors: Ki Dae-Han , Jung Young-Dae
Published: August 2010

The nonthermal and screening effects on the Thompson scattering process are investigated in generalized Lorentzian electron plasmas. The Thompson scattering cross section is obtained as a function of the spectral index, wave number, and Debye length. It is shown that the nonthermal effect suppresses the Thompson scattering process in Lorentzian plasmas. It is also shown that the nonthermal effects on the forward scatterings are more significant than those on the backward scatterings. In addition, the nonthermal effects are found to be more significant in the intermediate domain of the wave number.
Challenges in designing digital interfaces for the study of multimodal phenomena
Authors: O’Halloran Kay , Tan Sabine , Smith Bradley , Podlasov Alexey
Published: August 2010

The paper discusses the challenges faced by researchers in developing effective digital interfaces for analyzing the meaning-making processes of multimodal phenomena. The authors propose a social semiotic approach as the underlying theoretical foundation, because interactive digital technology is the embodiment of multimodal social semiotic communication. The paper outlines the complex issues with which researchers are confronted in designing digital interface frameworks for modeling, analyzing, and retrieving meaning from multimodal data, giving due consideration to the multiplicity of theoretical frameworks and theories which have been developed for the study of multimodal text within social semiotics, and their impact on the development of a computer-based tool for the exploration, annotation, and analysis of multimodal data.
Conditions defining the mechanisms of the formation of light gas ions in multicomponent laser-produced plasmas
Authors: Khaydarov R.T. , Beisinbaeva H.B. , Sabitov M.M. , Kalal Milan , Berdiyorov G.R.
Published: August 2010

Using the mass-spectrometric method we study the charge, energy and spatial characteristics of ions in multicomponent plasma, generated under the action of Nd : YAG laser radiation on the surface of solid targets. We focus on the effect of the entry form of light gas atoms on the parameters of ions in such laser-produced plasmas. We found that the presence of light gas atoms considerably affects the parameters (e.g. the intensity and the charge multiplicity) of the heavier ions.
Electron cyclotron heating during ECRH-assisted pre-ionization in a tokamak
Authors: Seol JaeChun , Park B.H. , Kim S.S. , Kim J.Y. , Na Yong-Su
Published: August 2010

In this research, we investigate electron cyclotron resonance heating (ECRH) for low-energy electrons analytically and numerically, which is applicable to ECRH-assisted plasma start-up in a tokamak. From the previous experimental studies, it is well known that the first harmonic ECRH is more effective than the second harmonic ECRH. In this work, we develop an analytic model of ECRH in the start-up process and present comparisons of efficiency between the first harmonic and the second harmonic. It is found that electrons gain a large amount of energy from the waves at the first harmonic resonance up to several hundred electronvolts. However, electrons gain a large amount of energy from the waves only up to ∼10 eV and the energy gain starts decreasing afterwards at the second harmonic resonance. When seed electrons are heated from room temperature to a temperature far above the ionization energy, the seed electrons can bring about an avalanche of electrons. Thus, pre-ionization with the second harmonic can be delayed since electrons need more time to be heated up to the breakdown temperature due to the slow heating speed compared with the first harmonic ECRH.
Tree metrics and their Lipschitz-free spaces
Authors: Godard A.
Published: August 2010

We compute the Lipschitz-free spaces of subsets of the real line and characterize subsets of metric trees by the fact that their Lipschitz-free space is isometric to a subspace of

L
1

L_1

.
Breast Pain
Authors: Harrison Faye , Halliday Melanie
Published: August 2010

Breast pain, or mastalgia, is a common symptom experienced by up to two-thirds of women. They often present to their GP fearing that this is a symptom of breast cancer. Most have only mild-to-moderate breast pain and accept this as part of the normal changes that occur during their menstrual cycle. Some women, however, have more severe symptoms requiring treatment. As a GP it is essential to be able to competently take a history and examine a woman complaining of breast pain to ensure there is no underlying sinister cause and then be able to explain, reassure and offer advice on how to manage symptoms.
Poisoning and Overdose
Authors: Whitehouse Anne
Published: August 2010

Poisoning is a significant public health concern in the UK. Accidental poisoning and deliberate self-poisoning may involve drugs, household products, environmental contaminants or occur as a result of occupational exposure. This article aims to provide a strategy for GPs to use for assessment and management of patients presenting in the community with a history of exposure to poisons.
Supportless oxygen reduction electrocatalysts of CoCuPt hollow nanoparticles
Authors: Wu Jianbo , Peng Zhenmeng , Yang Hong
Published: August 2010

This paper describes a facile solution route to the synthesis of CoCuPt hollow nanoparticles that readily form chain-like structures in solution. The formation of porous CoCuPt nanostructure is through galvanic replacement with cobalt-containing cores as the templates. This approach does not require the further removal of templates and greatly simplifies the synthetic procedures. These porous CoCuPt nanoparticles can be used as supportless electrocatalysts that exhibit enhanced mass- and area-specific activities in the oxygen reduction reaction (ORR) over commercial Pt black catalysts. The highest ORR specific activity achieved so far for this ternary Pt-alloy catalyst is 0.37 mA cm
−2
Pt
which is more than double that for Pt black.
Thiocystis chemoclinalis sp. nov. and Thiocystis cadagnonensis sp. nov., motile purple sulfur bacteria isolated from the chemocline of a meromictic lake
Authors: Peduzzi Sandro , Welsh Allana , Demarta Antonella , Decristophoris Paola , Peduzzi Raffaele , Hahn Dittmar , Tonolla Mauro
Published: August 2010

Two isolates, designated CadH11T and Cad448T, representing uncultured purple sulfur bacterial populations H and 448, respectively, in the chemocline of Lake Cadagno, a crenogenic meromictic lake in Switzerland, were obtained using enrichment and isolation conditions that resembled those used for cultured members of the genus Thiocystis. Phenotypic, genotypic and phylogenetic analyses of these isolates confirmed their assignment to the genus Thiocystis. However, 16S rRNA gene sequence similarities of 98.2 % between CadH11T and Cad448T, and similarities of 97.7 and 98.5 %, respectively, with their closest cultured relative Thiocystis gelatinosa DSM 215T, as well as differences in DNA G+C content and carbon source utilization suggested that the isolates belonged to two distinct species. DNA–DNA hybridization of CadH11T and Cad448T with T. gelatinosa DSM 215T showed relatedness values of 46.4 and 60.8 %, respectively; the relatedness value between CadH11T and Cad448T was 59.2 %. Based on this evidence, strains CadH11T and Cad448T represent two novel species within the genus Thiocystis, for which the names Thiocystis chemoclinalis sp. nov. and Thiocystis cadagnonensis sp. nov. are proposed, respectively. The type strains of T. chemoclinalis sp. nov. and T. cadagnonensis sp. nov. are CadH11T ( = JCM 15112T  = KCTC 5954T) and Cad448T ( = JCM 15111T  = KCTC 15001T), respectively.
Actinopolyspora alba sp. nov. and Actinopolyspora erythraea sp. nov., isolated from a salt field, and reclassification of Actinopolyspora iraqiensis Ruan et al. 1994 as a heterotypic synonym of Saccharomonospora halophila
Authors: Tang Shu-Kun , Wang Yun , Klenk Hans-Peter , Shi Rong , Lou Kai , Zhang Yun-Jiao , Chen Chao , Ruan Ji-Sheng , Li Wen-Jun
Published: August 2010

Three actinomycetal strains, designated YIM 90479, YIM 90480T and YIM 90600T, were isolated from a salt field in Xinjiang province, North-west China and subjected to polyphasic taxonomic study. All three strains were moderately halophilic and were able to grow on agar at NaCl concentrations of up to 20–25 % (w/v). No growth was observed in the absence of NaCl. Good growth occurred at 37 °C and 15 % (w/v) NaCl. The cell walls of the three strains were of the type IV variety and their phospholipid patterns were type PIII. MK-9 (H4) and MK-10 (H4) or MK-9 (H4) and MK-9 (H2) were the predominant menaquinones. iso-C16 : 0 and anteiso-C17 : 0 or anteiso-C15 : 0 and anteiso-C17 : 0 were the major fatty acids. The G+C contents of the genomic DNA were 66.4–68.3 mol%. Based on differential phenotypic, chemotaxonomic and phylogenetic characteristics and the results of DNA–DNA hybridization tests, the three novel stains represent two novel species, for which the names Actinopolyspora alba sp. nov. and Actinopolyspora erythraea sp. nov. are proposed. The type strains of the species are YIM 90480T ( = DSM 45004T  = KCTC 19119T) and YIM 90600T ( = CCTCC M 208247T  = KCTC 19372T). In addition, we propose that Actinopolyspora iraqiensis (Ruan et al., 1994) be transferred to the genus Saccharomonospora as a heterotypic synonym of Saccharomonospora halophila based on present research results.
Cellulomonas phragmiteti sp. nov., a cellulolytic bacterium isolated from reed (Phragmites australis) periphyton in a shallow soda pond
Authors: Rusznyák Anna , Tóth Erika M. , Schumann Peter , Spröer Cathrin , Makk Judit , Szabó Gitta , Vladár Péter , Márialigeti Károly , Borsodi Andrea K.
Published: August 2010

An alkalitolerant and moderately halophilic strain, designated KB23T, characterized by optimal growth at pH 8.0–9.0 and in the presence of 5–7 % (w/v) NaCl, was isolated from a reed (Phragmites australis) periphyton sample originating from an extremely shallow, alkaline soda pond located in Hungary. Cells of strain KB23T were Gram-stain-positive, motile straight rods. Strain KB23T was facultatively anaerobic, catalase-positive, oxidase-negative and contained peptidoglycan type A4β (l-Orn–d-Asp). MK-9(H4) was the predominant isoprenoid quinone and anteiso-C15 : 0, C16 : 0 and anteiso-C15 : 1 were the major cellular fatty acids. The DNA G+C content of strain KB23T was 74.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belongs to the genus Cellulomonas and that it is related most closely to Cellulomonas
flavigena DSM 20109T (97.35 % similarity), Cellulomonas
terrae DB5T (96.81 %), Cellulomonas
iranensis OT (96.75), Cellulomonas
chitinilytica X.bu-bT (96.60 %), Cellulomonas
persica IT (96.53 %), Cellulomonas
composti TR7-06T (96.45 %), Cellulomonas
biazotea DSM 20112T (96.34 %) and Cellulomonas
fimi DSM 20113T (96.20 %). According to these results, together with DNA–DNA hybridization and physiological data, strain KB23T is considered to represent a novel species of the genus Cellulomonas, for which the name Cellulomonas phragmiteti sp. nov. is proposed. The type strain is KB23T ( = DSM 22512T  = NCAIM B002303T).
Eionea nigra gen. nov., sp. nov., a gammaproteobacterium from the Mediterranean Sea
Authors: Urios Laurent , Intertaglia Laurent , Lesongeur Françoise , Lebaron Philippe
Published: August 2010

A novel aerobic, Gram-negative bacterial strain, designated 17X/A02/237T, was isolated from waters of the coastal north-western Mediterranean Sea. Cells were motile straight rods and formed dark-grey colonies on marine agar medium. Strain 17X/A02/237T contained ubiquinone Q-8 and its major fatty acids were C16 : 1ω7c and/or iso-C15 : 0 2-OH, C18 : 1ω7c, C16 : 0, C18 : 0 and C10 : 0 3-OH. The G+C content of the genomic DNA was 47.5 mol%. Phylogenetic analysis of the 16S rRNA gene sequence placed the strain in the class Gammaproteobacteria. Based on 16S rRNA gene sequence data, as well as physiological and biochemical characteristics, this isolate represents a novel species of a new genus, for which the name of Eionea nigra gen. nov., sp. nov. is proposed. The type strain is 17X/A02/237T ( = DSM 19752T = CIP 109759T = MOLA 288T).
Pisciglobus halotolerans gen. nov., sp. nov., isolated from fish sauce
Authors: Tanasupawat Somboon , Thongsanit Jaruwan , Thawai Chitti , Lee Keun Chul , Lee Jung-Sook
Published: August 2010

Two strains of Gram-stain-positive, catalase-negative, tetrad-forming cocci, C01T and C02, were isolated in Thailand from fish sauce. They were facultatively anaerobic, non-motile and non-spore-forming bacteria. These strains produced l-lactic acid from glucose. They grew at pH 5.0–9.0, at 15–40 °C and in the presence of 10 % (w/v) NaCl. The dominant fatty acid was C18 : 1ω9c. The DNA G+C contents of strains C01T and C02 were 38.6 and 38.7 mol%, respectively. Strain C01T was related most closely to Desemzia incerta DSM 20581T, with a 16S rRNA gene sequence similarity of 96.9 %. The strains could be distinguished clearly from D. incerta DSM 20581T based on cell morphology, physiological and biochemical characteristics and low levels of DNA–DNA relatedness. On the basis of the data presented, strains C01T and C02 are considered to represent a novel species of a new genus in the Bacillus–Lactobacillus cluster, for which the name Pisciglobus halotolerans gen. nov., sp. nov. is proposed. The type strain of Pisciglobus halotolerans is C01T ( = KCTC 13150T  = TISTR 1958T  = PCU 316T).
Zhihengliuella aestuarii sp. nov., isolated from tidal flat sediment
Authors: Baik Keun Sik , Lim Chae Hong , Park Seong Chan , Choe Han Na , Kim Ho Jun , Kim DuWoon , Lee Kang Hyun , Seong Chi Nam
Published: August 2010

A Gram-stain-positive, ovoid to short rod-shaped, yellow-pigmented bacterium, designated strain DY66T, was isolated from tidal-flat sediment collected from Deukryang Bay (Republic of Korea), and its taxonomic position was investigated by using a polyphasic approach. Strain DY66T grew optimally at 30 °C and pH 8–9 and in 2 % (w/v) NaCl. The peptidoglycan type was A4α, l-Lys–l-Ala–d-Glu, and tyvelose and glucose were the major cell-wall sugars. The predominant menaquinones were MK-10 and MK-9. Major cellular fatty acids (>10 % of total) were anteiso-C15 : 0 and iso-C15 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, an unknown aminophospholipid and three unknown aminolipids. The DNA G+C content was 59.1 mol%. This chemotaxonomic profile supported the assignment of strain DY66T to the genus Zhihengliuella. Phylogenetic analysis based on 16S rRNA gene sequences also indicated that strain DY66T belonged to the family Micrococcaceae and was related to the genus Zhihengliuella. On the basis of the evidence presented in this study, strain DY66T represents a novel species of the genus Zhihengliuella, for which the name Zhihengliuella aestuarii sp. nov. is proposed. The type strain is strain DY66T ( = KCTC 19557T  = JCM 16364T).
Yeasts in the Sugiyamaella clade associated with wood-ingesting beetles and the proposal of Candida bullrunensis sp. nov.
Authors: Houseknecht Janice L. , Hart Erica L. , Suh Sung-Oui , Zhou Jianlong J.
Published: August 2010

During a survey of yeasts associated with wood-ingesting insects, six strains of theSugiyamaellaclade were isolated from the gut of passalid and tenebrionid beetles and the decayed wood inhabited by them. Phylogeny based on rRNA gene sequences placed these yeasts as members ofSugiyamaella smithiae,Sugiyamaella americana,Candida lignohabitansand a novel species closely related toSu. americana. The only strain of the novel species, EH008T, could be unquestionably distinguished from its relatives by DNA sequences and other taxonomic characteristics. Ascospore production was not observed under the laboratory conditions tested. Therefore, this novel species is proposed asCandida bullrunensissp. nov. (type strain EH008T = ATCC MYA-4660T = CBS 11840T).
Region-specific involvement of actin rearrangement-related synaptic structure alterations in conditioned taste aversion memory
Authors: Bi Ai-Ling , Wang Yue , Li Bo-Qin , Wang Qian-Qian , Ma Ling , Yu Hui , Zhao Ling , Chen Zhe-Yu
Published: August 2010

Actin rearrangement plays an essential role in learning and memory; however, the spatial and temporal regulation of actin dynamics in different phases of associative memory has not been fully understood. Here, using the conditioned taste aversion (CTA) paradigm, we investigated the region-specific involvement of actin rearrangement-related synaptic structure alterations in different memory processes. We found that CTA training could induce increased postsynaptic density (PSD) length in insular cortex (IC), but not in basolateral amygdala (BLA) and prelimbic cortex (PrL) during short-term memory (STM) formation, whereas it led to increased PSD length and synapse density in both IC and PrL during long-term memory (LTM) formation. Inhibition of actin rearrangement in the IC, but not in the BLA and PrL, impaired memory acquisition. Furthermore, actin dynamics in the IC or PrL is necessary for memory consolidation. On the contrary, inhibition of actin dynamics in the IC, BLA, or PrL had no effect on CTA memory retrieval. Our results suggest temporal and regional-specific regulation of actin rearrangement-related synaptic structure in different phases of CTA memory.
The AP-3 β Adaptin Mediates the Biogenesis and Function of Lytic Vacuoles inArabidopsis
Authors: Feraru Elena , Paciorek Tomasz , Feraru Mugurel I. , Zwiewka Marta , De Groodt Ruth , De Rycke Riet , Kleine-Vehn Jürgen , Friml Jiří
Published: August 2010

Plant vacuoles are essential multifunctional organelles largely distinct from similar organelles in other eukaryotes. Embryo protein storage vacuoles and the lytic vacuoles that perform a general degradation function are the best characterized, but little is known about the biogenesis and transition between these vacuolar types. Here, we designed a fluorescent marker–based forward genetic screen in Arabidopsis thaliana and identified a protein affected trafficking2 (pat2) mutant, whose lytic vacuoles display altered morphology and accumulation of proteins. Unlike other mutants affecting the vacuole, pat2 is specifically defective in the biogenesis, identity, and function of lytic vacuoles but shows normal sorting of proteins to storage vacuoles. PAT2 encodes a putative β-subunit of adaptor protein complex 3 (AP-3) that can partially complement the corresponding yeast mutant. Manipulations of the putative AP-3 β adaptin functions suggest a plant-specific role for the evolutionarily conserved AP-3 β in mediating lytic vacuole performance and transition of storage into the lytic vacuoles independently of the main prevacuolar compartment-based trafficking route.
TDIF Peptide Signaling Regulates Vascular Stem Cell Proliferation via theWOX4Homeobox Gene inArabidopsis
Authors: Hirakawa Yuki , Kondo Yuki , Fukuda Hiroo
Published: August 2010

The indeterminate nature of plant growth and development depends on the stem cell system found in meristems. The Arabidopsis thaliana vascular meristem includes procambium and cambium. In these tissues, cell–cell signaling, mediated by a ligand-receptor pair made of the TDIF (for tracheary element differentiation inhibitory factor) peptide and the TDR/PXY (for TDIF RECEPTOR/ PHLOEM INTERCALATED WITH XYLEM) membrane protein kinase, promotes proliferation of procambial cells and suppresses their xylem differentiation. Here, we report that a WUSCHEL-related HOMEOBOX gene, WOX4, is a key target of the TDIF signaling pathway. WOX4 is expressed preferentially in the procambium and cambium, and its expression level was upregulated upon application of TDIF in a TDR-dependent manner. Genetic analyses showed that WOX4 is required for promoting the proliferation of procambial/cambial stem cells but not for repressing their commitment to xylem differentiation in response to the TDIF signal. Thus, at least two intracellular signaling pathways that diverge after TDIF recognition by TDR might regulate independently the behavior of vascular stem cells. Detailed observations in loss-of-function mutants revealed that TDIF-TDR-WOX4 signaling plays a crucial role in the maintenance of the vascular meristem organization during secondary growth.
TheUstilago maydisClp1 Protein Orchestrates Pheromone andb-Dependent Signaling Pathways to Coordinate the Cell Cycle and Pathogenic Development
Authors: Heimel Kai , Scherer Mario , Schuler David , Kämper Jörg
Published: August 2010

Regulation of the cell cycle and morphogenetic switching during pathogenic and sexual development in Ustilago maydis is orchestrated by a concerted action of the a and b mating-type loci. Activation of either mating-type locus triggers the G2 cell cycle arrest that is a prerequisite for the formation of the infectious dikaryon; this cell cycle arrest is released only after penetration of the host plant. Here, we show that bW, one of the two homeodomain transcription factors encoded by the b mating-type locus, and the zinc-finger transcription factor Rbf1, a master regulator for pathogenic development, interact with Clp1 (clampless 1), a protein required for the distribution of nuclei during cell division of the dikaryon. In addition, we identify Cib1, a previously undiscovered bZIP transcription factor required for pathogenic development, as a Clp1-interacting protein. Clp1 interaction with bW blocks b-dependent functions, such as the b-dependent G2 cell cycle arrest and dimorphic switching. The interaction of Clp1 with Rbf1 results in the repression of the a-dependent pheromone pathway, conjugation tube formation, and the a-induced G2 cell cycle arrest. The concerted interaction of Clp1 with Rbf1 and bW coordinates a- and b-dependent cell cycle control and ensures cell cycle release and progression at the onset of biotrophic development.
The fall and rise of knowledge organization: new dimensions of subject description and retrieval
Authors: Broughton Vanda
Published: August 2010

Purpose

The purpose of this editorial is to introduce the selected Proceedings of the 1st National Conference of ISKO UK, the UK Chapter of the International Society for Knowledge Organization. It aims to provide some background for the group, and place it within the context of the recent history of information organization and retrieval in subject domains.

Design/methodology/approach

The paper introduces a selection of papers delivered at the 1st National Conference of the UK Chapter of the International Society for Knowledge Organization.

Findings

The field of knowledge organization is lively and progressive, and researchers and practitioners in many sectors are actively engaged with it, despite its apparent decline in LIS education. New communities of interest may use different terms to describe this work, but there is much common ground, and a growing convergence of ideas and methods.

Originality/value

The value of existing theory is now more widely recognised, and the importance of structured knowledge organization systems and vocabularies in retrieval is generally acknowledged. It is to be hoped that these important areas of information practice and research will soon be restored to their former place in professional education.
Lessons learned in content architecture harmonization and metadata models
Authors: Wagger Shana , Park Randi , Dowding Bedford Denise Ann
Published: August 2010

Purpose

This paper aims to review key content, architecture, and metadata model decisions and strategies in creation of a publication portal (on DVD to start), based on a 30+ year series of flagship reports from the World Bank.

Design/methodology/approach

The paper describes and analyzes key considerations and aspects of the project, including content architecture, content analysis, DTD selection, retrospective conversion, vendor management, design of metadata architectures, use of automated profiling methods, user‐information behavior, and search architectures supporting complex content architectures. It includes the challenges of applying an institutionally based taxonomy required to express subject‐matter responsibilities and relationships within the World Bank.

Findings

The team learned that the metadata behavior and architecture (inheritance, relationships, variations) are more complex than simple links between parent and child objects. The project also reinforced the importance of comprehensive and dynamic topic taxonomy for classifying content that is both historical and current. The approach to defining classes for each full report (parent) will be likely to change, given what has been learned. The team would recommend that parts be classified and the sum of the part classes be assigned to the whole report. As a result of this exploratory work, the Bank's approach to classification and indexing of report series is changing from a top‐down to a bottom‐up inheritance.

Originality/value

The study provides insights into both general and World Bank‐specific challenges in creating a publication portal and derives some best practices for content architecture, metadata architecture, and use of automated profiling methods.
“Content architecture”
Authors: Boteram Felix
Published: August 2010

Purpose

This paper seeks to develop a specified typology of various levels of semantic interoperability, designed to provide semantically expressive and functional means to interconnect typologically different sub‐systems in an international comprehensive knowledge organization system, supporting advanced information retrieval and exploration strategies.

Design/methodology/approach

Taking the analysis of rudimentary forms of a functional interoperability based on simple pattern matching as a starting‐point, more refined strategies to provide semantic interoperability, which is actually reaching the conceptual and even thematic level, are being developed. The paper also examines the potential benefits and perspectives of the selective transfer of modelling strategies from the field of semantic technologies for the refinement of relational structures of inter‐system and inter‐concept relations as a requirement for expressive and functional indexing languages supporting advanced types of semantic interoperability.

Findings

As the principles and strategies of advanced information retrieval systems largely depend on semantic information, new concepts and strategies to achieve semantic interoperability have to be developed.

Research limitations/implications

The approach has been developed in the functional and structural context of an international comprehensive system integrating several heterogeneous knowledge organization systems and indexing languages by interconnecting them to a central conceptual structure operating as a spine in an overall system designed to support retrieval and exploration of bibliographic records representing complex conceptual entities.

Originality/value

Research and development aimed at providing technical and structural interoperability has to be complemented by a thorough and precise reflection and definition of various degrees and types of interoperability on the semantic level as well. The approach specifies these levels and reflects the implications and their potential for advanced strategies of retrieval and exploration.
Large‐scale grid computing for content‐based image retrieval
Authors: Town Chris , Harrison Karl
Published: August 2010

Purpose

Content‐based image retrieval (CBIR) technologies offer many advantages over purely text‐based image search. However, one of the drawbacks associated with CBIR is the increased computational cost arising from tasks such as image processing, feature extraction, image classification, and object detection and recognition. Consequently CBIR systems have suffered from a lack of scalability, which has greatly hampered their adoption for real‐world public and commercial image search. At the same time, paradigms for large‐scale heterogeneous distributed computing such as grid computing, cloud computing, and utility‐based computing are gaining traction as a way of providing more scalable and efficient solutions to large‐scale computing tasks.

Design/methodology/approach

This paper presents an approach in which a large distributed processing grid has been used to apply a range of CBIR methods to a substantial number of images. By massively distributing the required computational task across thousands of grid nodes, very high through‐put has been achieved at relatively low overheads.

Findings

This has allowed one to analyse and index about 25 million high resolution images thus far, while using just two servers for storage and job submission. The CBIR system was developed by Imense Ltd and is based on automated analysis and recognition of image content using a semantic ontology. It features a range of image‐processing and analysis modules, including image segmentation, region classification, scene analysis, object detection, and face recognition methods.

Originality/value

In the case of content‐based image analysis, the primary performance criterion is the overall through‐put achieved by the system in terms of the number of images that can be processed over a given time frame, irrespective of the time taken to process any given image. As such, grid processing has great potential for massively parallel content‐based image retrieval and other tasks with similar performance requirements.
An evaluation of enhancing social tagging with a knowledge organization system
Authors: Matthews Brian , Jones Catherine , Puzoń Bartłomiej , Moon Jim , Tudhope Douglas , Golub Koraljka , Lykke Nielsen Marianne
Published: August 2010

Purpose

Traditional subject indexing and classification are considered infeasible in many digital collections. This paper seeks to investigate ways of enhancing social tagging via knowledge organization systems, with a view to improving the quality of tags for increased information discovery and retrieval performance.

Design/methodology/approach

Enhanced tagging interfaces were developed for exemplar online repositories, and trials were undertaken with author and reader groups to evaluate the effectiveness of tagging augmented with control vocabulary for subject indexing of papers in online repositories.

Findings

The results showed that using a knowledge organisation system to augment tagging does appear to increase the effectiveness of non‐specialist users (that is, without information science training) in subject indexing.

Research limitations/implications

While limited by the size and scope of the trials undertaken, these results do point to the usefulness of a mixed approach in supporting the subject indexing of online resources.

Originality/value

The value of this work is as a guide to future developments in the practical support for resource indexing in online repositories.
Biodiversity information retrieval across networked data sets
Authors: Sarinder K.K.S. , Lim L.H.S. , Merican A.F. , Dimyati K.
Published: August 2010

Purpose

Biodiversity resources are inevitably digital and stored in a wide variety of formats by researchers or stakeholders. In Malaysia, although digitizing biodiversity data has long been stressed, the interoperability of the biodiversity data is still an issue that requires attention. This is because, when data are shared, the question of copyright occurs, creating a setback among researchers wanting to promote or share data through online presentations. To solve this, the aim is to present an approach to integrate data through wrapping of datasets stored in relational databases located on networked platforms.

Design/methodology/approach

The approach uses tools such as XML, PHP, ASP and HTML to integrate distributed databases in heterogeneous formats. Five current database integration systems were reviewed and all of them have common attributes such as query‐oriented, using a mediator‐based approach and integrating a structured data model. These common attributes were also adopted in the proposed solution. Distributed Generic Information Retrieval (DiGIR) was used as a model in designing the proposed solution.

Findings

A new database integration system was developed, which is user‐friendly and simple with common attributes found in current integration systems.

Originality/value

The proposed system is unique in that it allows biodiversity data sharing, through the integration of biodiversity databases, hence enabling scientists to share information and generate knowledge. It also solves copyright problems by suggesting distributed warehouses, giving data owners the benefit of having their database under their own jurisdiction. It meets the requirements of querying heterogeneous and remote biodiversity databases.
Longitudinal roughness effect on magnetic fluid‐based squeeze film between conical plates
Authors: Indubhai Andharia Paresh , Deheri Gunamani
Published: August 2010

Purpose

The paper aims to improve upon the performance of a squeeze film formed by a magnetic fluid between longitudinally rough conical plates.

Design/methodology/approach

The objectives are achieved by mathematically modeling a magnetic fluid‐based squeeze film between longitudinally rough conical plates. The roughness of the bearing surface is modeled by a stochastic random variable with non‐zero mean, variance and skewness. The standard approach is to solve associated Reynold's equation which is stochastically averaged with respect to the random roughness parameter. The scope of this paper is the industrial applications with regard to enhanced performance of the bearing system.

Findings

The findings indicate that the performance of the bearing gets enhanced due to negatively skewed roughness. It is also noticed that the standard deviation increases the load carrying capacity which is unlike the case of transverse surface roughness. Further, this paper suggests that there exist considerable scopes for enhancing the performance of the longitudinally rough bearing system by choosing a suitable combination of the magnetization parameter and the semi‐vertical angle of the cone.

Practical implications

From the industry point of view, this investigation will be certainly useful for improving the performance of a magnetic fluid‐based squeeze film between longitudinally rough conical plates.

Originality/value

The paper presents the improved performance of a squeeze film formed by a magnetic fluid between longitudinally rough conical plates and thereby extending the life period of the bearing system.
Tribological properties of water‐soluble TiO2 nanoparticles as additives in water
Authors: Wang Jianhua , Li Jinlong , Wang Xiaobo , Liu Weimin
Published: August 2010

Purpose

The purpose of this paper is to prepare water‐soluble TiO2 nanoparticles and evaluate the tribological properties as additives in water.

Design/methodology/approach

Nanoparticles present excellent friction‐reducing and antiwear properties as additives in base oils. However, there are seldom literatures about the nanoparticles as additives in water as yet. In this work, water‐soluble TiO2 nanoparticles were prepared by sol‐gel method and characterized with transmission electron microscopy and selected area electron diffraction. The tribological properties as additives in water were investigated by SRV and the surface analysis by scanning electron microscope and X‐ray photon electron spectroscope.

Findings

TiO2 nanoparticles modified with polyethylene glycol have uniform size about 10 nm and easily dissolve in water. The tribological experiments showed TiO2 nanoparticles exhibit excellent friction‐reducing and antiwear properties.

Research limitations/implications

The paper is restricted to only TiO2 nanoparticles. Some other water‐soluble nanoparticles also should be prepared and their tribological properties investigated.

Practical implications

Water‐soluble TiO2 nanoparticles could be used as water additives and improve the tribological properties.

Originality/value

This paper emphasises that the water‐soluble nanoparticles are prepared and could be used as water additives.
Foresight in static stiffness of hydrostatic bearings with various compensations by film gradient versus recess pressure
Authors: Kang Yuan , Chen Cheng‐Hsien , Lee Jian‐Lin , Chen Juhn‐Horng , Chang Yeon‐Pun
Published: August 2010

Purpose

The purpose of this paper is to investigate the static stiffness of hydrostatic bearings with three constant compensations in types of constant‐flow pump, capillary and orifice, and both single‐action and double‐action variable restrictors with cylindrical‐spool, tapered‐spool, and membrane types by film gradient and recess pressure.

Design/methodology/approach

This paper utilizes the equations of flow equilibrium to determine the variations of film thickness or displacement of loading table with respect to the varying of recess pressure. For a hydrostatic bearing whose recess pressures are controlled by compensations, the stiffness characteristics can be presented directly by these variations.

Findings

The usage range of recess pressure and compensation parameters should be selected to correspond to a variation with smallest gradient.

Originality/value

This paper proposes an extensive database as a critical requirement for the selection of types and parameters of the compensation as to yield the acceptable or optimized characteristics in design of hydrostatic bearings.