bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature dependence of terahertz emission by an asymmetric intrinsic Josephson junction device
Authors: Kakeya Itsuhiro , Hirayama Nobuo , Omukai Yuta , Suzuki Minoru
Published: January 2015

This study investigates the effect of temperature on the emission frequency of an intrinsic Josephson junction terahertz (THz) electromagnetic wave source, which can be used for high-speed communications by THz carrier wave. The characteristic emission features of two device types (asymmetric and symmetric) and two bias regimes (low and high) were determined. The bias-dependent emission frequency was temperature dependent in the asymmetric device, most likely reflecting the temperature-dependent London penetration depth. The bias tunability of the emission frequency can be explained by device self-heating, which significantly and inhomogeneously raises the temperatures of the device from its bath temperature. These findings are consistent with previous studies of temperature distribution in these devices.
Tailoring dual-band electromagnetically induced transparency in planar metamaterials
Authors: Hu Sen , Yang Helin , Han Song , Huang Xiaojun , Xiao Boxun
Published: January 2015

The transmission characteristics of a planar metamaterial, composed of two finite metal strips (with different length) and one double split-ring resonator, have been numerically and experimentally investigated in this paper. By varying the length of the two strips slightly, this structure can exhibit single-band and dual-band electromagnetically induced transparency (EIT)-like spectral response in microwave region. The dark mode can be excited because of the length difference of the two metal strips, which can lead to a very asymmetric Fano-like resonance or gradually EIT-like profile in transmission. So the dual-band EIT-like physical mechanism is characterized by two bright-dark coupling modes. Our work provides a way to obtain multiple EIT-like effect, and it may achieve potential applications in a variety of fields including filters, sensing, and some other microwave devices.
Quantum dot spontaneous emission control in a ridge waveguide
Authors: Stepanov Petr , Delga Adrien , Zang Xiaorun , Bleuse Joël , Dupuy Emmanuel , Peinke Emanuel , Lalanne Philippe , Gérard Jean-Michel , Claudon Julien
Published: January 2015

We investigate the spontaneous emission (SE) of self-assembled InAs quantum dots (QDs) embedded in GaAs ridge waveguides that lay on a low index substrate. In thin enough waveguides, the coupling to the fundamental guided mode is vanishingly small. A pronounced anisotropy in the coupling to non-guided modes is then directly evidenced by normal-incidence photoluminescence polarization measurements. In this regime, a measurement of the QD decay rate reveals a SE inhibition by a factor up to 4. In larger wires, which ensure an optimal transverse confinement of the fundamental guided mode, the decay rate approaches the bulk value. Building on the good agreement with theoretical predictions, we infer from calculations the fraction β of SE coupled to the fundamental guided mode for some important QD excitonic complexes. For a charged exciton (isotropic in plane optical dipole), β reaches 0.61 at maximum for an on-axis QD. In the case of a purely transverse linear optical dipole, β increases up to 0.91. This optimal configuration is achievable through the selective excitation of one of the bright neutral excitons.
Note: Eddy current displacement sensors independent of target conductivity
Authors: Wang Hongbo , Li Wei , Feng Zhihua
Published: January 2015

Eddy current sensors (ECSs) are widely used for non-contact displacement measurement. In this note, the quantitative error of an ECS caused by target conductivity was analyzed using a complex image method. The response curves (L–x) of the ECS with different targets were similar and could be overlapped by shifting the curves on x direction with √2δ/2. Both finite element analysis and experiments match well with the theoretical analysis, which indicates that the measured error of high precision ECSs caused by target conductivity can be completely eliminated, and the ECSs can measure different materials precisely without calibration.
Bit error rate performance for head skew angle in shingled magnetic recording using dual reader heads
Authors: Nakamura Y. , Osawa H. , Okamoto Y. , Kanai Y. , Muraoaka H.
Published: January 2015

The two-dimensional magnetic recording (TDMR) exploits two-dimensional signal processing using the neighboring read-back waveforms. We allocate dual readers for the intended tracks and evaluate the effects of head skew angle on the bit error rate performance in partial response class-I maximum likelihood system with a two-dimensional finite impulse response filter using two read-back waveforms under TDMR R/W channel specifications of 4 Tbit/in.2. The results show that the effect of positive skew angle is larger than that of negative skew angle, and the center of skew angle should be shifted to minus direction.
On the bending characterization of flexible radio-frequency single-crystalline germanium diodes on a plastic substrate
Authors: Qin Guoxuan , Zuo Kelei , Seo Jung-Hun , Xu Yanmeng , Yuan Hao-Chih , Liu Hao , Huang Zhiyuan , Ma Jianguo , Ma Zhenqiang
Published: January 2015

Mechanical bending characterizations are performed on flexible radio-frequency (rf) single-crystalline germanium (Ge) diodes on plastic substrates. Transversal and longitudinal, convex, and concave bendings are conducted. Dc and rf experimental results indicate different performance dependence of the diodes on different types of bending strains, at different biases. Equivalent circuit model is employed to analyze the underlying mechanisms that affect the characteristics of the flexible Ge diodes under bending conditions. Less performance variations are observed for the flexible Ge diodes than the Si diodes with bending strains. The flexible single-crystalline Ge diodes demonstrate good high frequency response and robustness for mechanical bendings.
Tuning the graphene work function by uniaxial strain
Authors: He Xin , Tang Ning , Sun Xiaoxiao , Gan Lin , Ke Fen , Wang Tao , Xu Fujun , Wang Xinqiang , Yang Xuelin , Ge Weikun , Shen Bo
Published: January 2015

Forming good metal/graphene contact is of significance in making graphene devices, while tuning the graphene work function is a valid approach to decrease the contact barrier and then achieve electrodes with low contact resistance. A strain device has been fabricated to apply uniaxial strain to graphene grown by chemical vapor deposition method, and Kelvin probe force microscopy was used to measure the work function of the graphene under strain. The work function of the graphene is found to increase as strain increases. By applying a uniaxial strain of 7%, the work function can be adjusted as large as 0.161 eV. Such a result can be explained by strain induced increase of the density of states in graphene.
Atomic study on the ordered structure in Al melts induced by liquid/substrate interface with Ti solute
Authors: Zhang H. L. , Han Y. F. , Zhou W. , Dai Y. B. , Wang J. , Sun B. D.
Published: January 2015

Atomic ordering in Al melts induced by liquid/substrate interface with Ti solute was investigated by ab initio molecular dynamics simulations and in-situ synchrotron X-ray diffraction. It is predicted that deformed nanoscale ordering Al layers with a rhombohedral-centered hexagonal structure (R3¯m space group) instead of the intrinsic fcc structure (Fm3¯m space group) form on substrate at temperature above Al liquids. With Al atoms stacking away from the interface, the ordering structure reaches a critical thickness, which inhibits the consecutive stacking of Al atoms on substrates. The locally stacking reconstruction induced by Ti atom relieves the accumulated elastic strain energy in ordered Al layers, facilitating fully heterogeneous nucleation on substrate beyond the deformed ordering Al layer around the melting point. The roles of liquid/substrate interface with Ti solute in the physical behavior of heterogeneous nucleation on substrate were discussed.
Investigating the origin of efficiency droop by profiling the temperature across the multi-quantum well of an operating light-emitting diode
Authors: Jung Euihan , Hwang Gwangseok , Chung Jaehun , Kwon Ohmyoung , Han Jaecheon , Moon Yong-Tae , Seong Tae-Yeon
Published: January 2015

Performance degradation resulting from efficiency droop during high-power operation is a critical problem in the development of high-efficiency light-emitting diodes (LEDs). In order to resolve the efficiency droop and increase the external quantum efficiency of LEDs, the droop's origin should be identified first. To experimentally investigate the cause of efficiency droop, we used null-point scanning thermal microscopy to quantitatively profile the temperature distribution on the cross section of the epi-layers of an operating GaN-based vertical LED with nanoscale spatial resolution at four different current densities. The movement of temperature peak towards the p-GaN side as the current density increases suggests that more heat is generated by leakage current than by Auger recombination. We therefore suspect that at higher current densities, current leakage becomes the dominant cause of the droop problem.
Second order phase transition temperature of single crystals of Gd5Si1.3Ge2.7 and Gd5Si1.4Ge2.6
Authors: Hadimani R. L. , Melikhov Y. , Schlagel D. L. , Lograsso T. A. , Dennis K. W. , McCallum R. W. , Jiles D. C.
Published: January 2015

Gd5(SixGe1−x)4 has mixed phases in the composition range 0.32 < x < 0.41, which have not been widely studied. In this paper, we have synthesized and indexed single crystal samples of Gd5Si1.3Ge2.7 and Gd5Si1.4Ge2.6. We have investigated the first order and second order phase transition temperatures of these samples using magnetic moment vs. temperature and magnetic moment vs. magnetic field at different temperatures. We have used a modified Arrott plot technique that was developed and reported by us previously to determine the “hidden” second order phase transition temperature of the orthorhombic II phase.
Optical function spectra and bandgap energy of Cu2SnSe3
Authors: Choi S. G. , Kang J. , Li J. , Haneef H. , Podraza N. J. , Beall C. , Wei S.-H. , Christensen S. T. , Repins I. L.
Published: January 2015

We present the optical function spectra of Cu2SnSe3 determined from 0.30 to 6.45 eV by spectroscopic ellipsometry (SE) at room temperature. We analyze the SE data using the Tauc-Lorentz model and obtain the direct-bandgap energy of 0.49 ± 0.02 eV, which is much smaller than the previously known value of 0.84 eV for the monoclinic-phase Cu2SnSe3. We also perform density-functional theory calculations to obtain the complex dielectric function data, and the results show good agreement with the experimental spectrum. Finally, we discuss the electronic origin of the main optical structures.
Jerky magnetic noises generated by cyclic deformation of martensite in Ni2MnGa single crystalline shape memory alloys
Authors: Daróczi Lajos , Gyöngyösi Szilvia , Tóth László Z. , Szabó Sándor , Beke Dezső L.
Published: January 2015

It is shown that during periodic deformation of martensitic Ni2MnGa single crystalline alloy jerky magnetic noises are emitted. Above a threshold limit in the deformation amplitude, the noise energy per deformation cycle showed increasing tendency with increasing deformation. Energy and amplitude probability distributions of the noise were characterized by power law functions. The energy exponents were independent of the deformation amplitude in the investigated range. The decrease of the noise energy as well as power exponents with increasing magnetic field was interpreted by the decrease of the multiplicity of the martensite variants.
Bulk relaxor ferroelectric ceramics as a working body for an electrocaloric cooling device
Authors: Plaznik Uroš , Kitanovski Andrej , Rožič Brigita , Malič Barbara , Uršič Hana , Drnovšek Silvo , Cilenšek Jena , Vrabelj Marko , Poredoš Alojz , Kutnjak Zdravko
Published: January 2015

The electrocaloric effect (ECE), i.e., the conversion of the electric into the thermal energy has recently become of great importance for development of a new generation of cooling technologies. Here, we explore utilization of [Pb(Mg1∕3Nb2∕3)O3]0.9[PbTiO3]0.1 (PMN-10PT) relaxor ceramics as active elements of the heat regenerator in an ECE cooling device. We show that the PMN-10PT relaxor ceramic exhibits a relatively large electrocaloric change of temperature ΔTEC > 1 K at room temperature. The experimental testing of the cooling device demonstrates the efficient regeneration and establishment of the temperature span between the hot and the cold sides of the regenerator, exceeding several times the ΔTEC within a single PMN-10PT ceramic plate.
Progressive failure site generation in AlGaN/GaN high electron mobility transistors under OFF-state stress: Weibull statistics and temperature dependence
Authors: Sun Huarui , Bajo Miguel Montes , Uren Michael J. , Kuball Martin
Published: January 2015

Gate leakage degradation of AlGaN/GaN high electron mobility transistors under OFF-state stress is investigated using a combination of electrical, optical, and surface morphology characterizations. The generation of leakage “hot spots” at the edge of the gate is found to be strongly temperature accelerated. The time for the formation of each failure site follows a Weibull distribution with a shape parameter in the range of 0.7–0.9 from room temperature up to 120 °C. The average leakage per failure site is only weakly temperature dependent. The stress-induced structural degradation at the leakage sites exhibits a temperature dependence in the surface morphology, which is consistent with a surface defect generation process involving temperature-associated changes in the breakdown sites.
Ion dynamics in an E × B Hall plasma accelerator
Authors: Young Christopher V. , Lucca Fabris Andrea , Cappelli Mark A.
Published: January 2015

We show the time evolution of the ion velocity distribution function in a Hall plasma accelerator during a 20 kHz natural, quasi-periodic plasma oscillation. We apply a time-synchronized laser induced fluorescence technique at different locations along the channel midline, obtaining time- and spatially resolved ion velocity measurements. Strong velocity and density fluctuations and multiple ion populations are observed throughout the so-called “breathing mode” ionization instability, opening an experimental window into the detailed ion dynamics and physical processes at the heart of such devices.
Dopant selection for control of charge carrier density and mobility in amorphous indium oxide thin-film transistors: Comparison between Si- and W-dopants
Authors: Mitoma Nobuhiko , Aikawa Shinya , Ou-Yang Wei , Gao Xu , Kizu Takio , Lin Meng-Fang , Fujiwara Akihiko , Nabatame Toshihide , Tsukagoshi Kazuhito
Published: January 2015

The dependence of oxygen vacancy suppression on dopant species in amorphous indium oxide (a-InOx) thin film transistors (TFTs) is reported. In a-InOx TFTs incorporating equivalent atom densities of Si- and W-dopants, absorption of oxygen in the host a-InOx matrix was found to depend on difference of Gibbs free energy of the dopants for oxidation. For fully oxidized films, the extracted channel conductivity was higher in the a-InOx TFTs containing dopants of small ionic radius. This can be explained by a reduction in the ionic scattering cross sectional area caused by charge screening effects.
High pressure processing of hydrogenated amorphous silicon solar cells: Relation between nanostructure and high open-circuit voltage
Authors: Fischer Marinus , Tan Hairen , Melskens Jimmy , Vasudevan Ravi , Zeman Miro , Smets Arno H. M.
Published: January 2015

This study gives a guideline on developing high bandgap, high quality hydrogenated amorphous silicon (a-Si:H) through a carefully engineered nanostructure. Single-junction a-Si:H solar cells with open-circuit voltages (Voc) above 950 mV and conversion efficiencies above 9% are realized by processing the absorber layers at high pressures of 7–10 mbar. The high Voc is a result of an increased bandgap, which is attributed to an increase in the average size of the open volume deficiencies in the absorber layer without a significant increase in the nanosized void density.
Ultraviolet stimulated emission from high-temperature-annealed MgO microcrystals at room temperature
Authors: Soma Haruka , Uenaka Yuki , Asahara Akifumi , Suemoto Tohru , Uchino Takashi
Published: January 2015

Research on semiconductor nanowires underlies the development of the miniaturization of laser devices with low cost and low energy consumption. In general, nanowire lasers are made of direct band gap semiconductors, e.g., GaN, ZnO and CdS, and their band-edge emissions are used to achieve optically pumped laser emission. In addition to the existing class of nanowire lasers, we here show that air-annealed micrometer-sized MgO cubic crystals with well-defined facets exhibit room-temperature stimulated emission at 394 nm under pulsed laser pumping at ∼350 nm. Surface midgap states are assumed to be responsible for the excitation and emission processes. The present findings will not only provide opportunities for the development of miniaturized lasers composed of insulating oxides, but will also open up functionality in various families of cubic crystalline materials.
Recombination and thin film properties of silicon nitride and amorphous silicon passivated c-Si following ammonia plasma exposure
Authors: Wan Yimao , McIntosh Keith R. , Thomson Andrew F. , Cuevas Andres
Published: January 2015

Recombination at silicon nitride (SiNx) and amorphous silicon (a-Si) passivated crystalline silicon (c-Si) surfaces is shown to increase significantly following an ammonia (NH3) plasma exposure at room temperature. The effect of plasma exposure on chemical structure, refractive index, permittivity, and electronic properties of the thin films is also investigated. It is found that the NH3 plasma exposure causes (i) an increase in the density of Si≡N3 groups in both SiNx and a-Si films, (ii) a reduction in refractive index and permittivity, (iii) an increase in the density of defects at the SiNx/c-Si interface, and (iv) a reduction in the density of positive charge in SiNx. The changes in recombination and thin film properties are likely due to an insertion of N–H radicals into the bulk of SiNx or a-Si. It is therefore important for device performance to minimize NH3 plasma exposure of SiNx or a-Si passivating films during subsequent fabrication steps.
Digging up the dirty past: evidence for stormwater’s contribution to pollution of an urban floodplain lake
Authors: Lintern Anna , Deletic Ana , Leahy Paul , McCarthy David
Published: January 2015

Negative effects of urbanisation on the health of aquatic environments are well recognised; but more data are needed for an accurate assessment of the particular effects of residential development on the health of aquatic systems. This study explores the relationship between residential growth and increasing pollution, by analysing temporal trends of chemical fluxes into Willsmere Billabong – an urban floodplain lake of the Yarra River in South-East Australia. Sediment cores were extracted to reveal depositions over three centuries (~1700–2012). The cores were sub-sampled at high resolution and analysed for heavy metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Pollutant concentrations in the sediments appear to have been significantly affected by residential development in the local catchment. Normalised concentration profiles show these effects to be exacerbated from the mid-20th century, after a stormwater drain was installed in the billabong. The study suggests that urban stormwater management techniques are critical for the protection of aquatic systems incorporated into residential zones.
On Okin’s critique of libertarianism
Authors: Hicks Daniel J.
Published: January 2015

Susan Moller Okin’s critique of libertarianism inJustice, Gender, and the Familyhas received only slight attention in the libertarian literature. I find this neglect of Okin’s argument surprising: The argument is straightforward and, if sound, it establishes a devastating conflict between the core libertarian notions of self-ownership and the acquisition of property through labour. In this paper, I first present a reconstruction of Okin’s argument. In brief, she points out that mothers make children through their labour; thus it would seem that mothers own their (adult) children; but this implies that the children are not self-owners. I then examine the two most common objections to this argument in the literature: mothers do not make children, and acquisition by labour includes an exception for persons. I give several replies to each objection, including an extension of Okin’s argument that I call Okin’s dilemma. This dilemma argues that the libertarian can avoid Okin’s conclusion only by requiring an involuntary property transfer. And this alternative, it seems, is just as unacceptable for many libertarians. I close with some speculation about the further implications of Okin’s dilemma for libertarianism.
Mere moral failure
Authors: Tannenbaum Julie
Published: January 2015

When, in spite of our good intentions, we fail to meet our obligations to others, it is important that we have the correct theoretical description of what has happened so that mutual understanding and the right sort of social repair can occur. Consider an agent who promises to help pick a friend up from the airport. She takes the freeway, forgetting that it is under construction. After a long wait, the friend takes an expensive taxi ride home. Most theorists and non-theorists react to such cases by either judging the agent’s action as a violation of her obligation to help or as having satisfied the only obligation she really had, namely to try to help. However, as I show, there are serious difficulties that arise from categorizing this agent’s action as satisfying or violating her obligation – difficulties that are avoided if we instead add “mere moral failures”; to the basic categories for moral evaluation. An agent merely fails when she neither satisfies nor violates her obligation. She is responsible for what she has done, yet without thereby having done wrong. Moreover, there is a recognizable (though nameless) reactive attitude reflecting the agent’s responsibility that falls between blame and mere regret, and is also importantly different from agent-regret. What I show is that we need not reach for blame as our only way of registering that an agent has morally failed another. While thus far overlooked, mere moral failure is by no means a rare occurrence, but rather a regular part of life among friends, family, investors and clients, police and citizens, doctors and patients, and many others.
Coming out strategies of lesbians and gays at work / Estrategias de coming out de personas lesbianas y gays en el trabajo
Authors: Di Marco Donatella , Arenas Alicia , Munduate Lourdes , Hoel Helge
Published: January 2015

In recent years there has been a great deal of social and legislative progress in the struggle against discrimination on grounds of sexual orientation. However, the coming out process in the workplace is still a crucial aspect in the lives of many lesbians and gays (LG). This study sets out to analyse the different strategies that Spanish LG adopt when revealing their sexual orientation at work by identifying the factors that facilitate or hinder this process. It also analyses the personal and organizational consequences of the strategies used in the coming out process. The study was carried out through in-depth interviews with 15 LG. Results show that the coming out strategies vary and are affected by different factors (e.g., characteristics of the colleagues, sector, etc.). Moreover, it confirmed that the coming out process (or its absence) can have consequences at different levels (e.g., relationships with colleagues, perception of organizational injustice, etc.).
The moderating effect of personal values in the relationship between working conditions and wellbeing / El efecto moderador de los valores personales en la relación entre condiciones de trabajo y bienestar
Authors: Paschoal Tatiane , Álvaro José-Luis , Barreiros-Porto Juliana
Published: January 2015

The main objective of this study was to evaluate the impact that the opportunities to realize personal values at work have on wellbeing. More specifically, we tried to test the moderating effect of personal values on the relationship between opportunities for fulfilment and wellbeing. A sample of 403 civil servants from a public institution in Brazil answered a questionnaire that included measures for each of the variables studied. The results from hierarchical regression showed that there were no significant interactions between opportunities to realize personal values at work and personal value priorities in the prediction of wellbeing at work. The mere presence of opportunities to realize values that express individual interests is enough to increase wellbeing. Likewise, the results converge with those of other previous studies on the importance of working conditions in predicting wellbeing. On the other hand, this study included variables that up to now have not been used in the field of wellbeing at work, especially in relation to its eudaimonic and hedonic elements.
Authentic leadership and its influence on group cohesion and organizational identification: the role of organizational justice as a mediating variable / El liderazgo auténtico y su influencia sobre la cohesión grupal y la identificación organizacional: el papel de la justicia organizacional como variable mediadora
Authors: García-Guiu Carlos , Molero Fernando , Moriano Juan A.
Published: January 2015

The aim of this study is to analyse the relationship between authentic leadership, group cohesion, organizational identification and the potential effect of organizational justice as a mediating variable. Partial Least Squares (PLS) modelling was used to analyse the data from 210 employees at several Spanish companies. The results showed that organizational justice as a mediator in the proposed model and positive relationships among the variables studied. These findings are discussed taking into account the importance of the authentic leadership model in the study of group processes in organizations and the development of policies and behaviours that promote ethics, transparency and justice in companies.
Fighting talk: Ruth First's early journalism 1947–1950
Authors: Webb Christopher
Published: January 2015

While celebrated for her anti-apartheid activism, Ruth First's early journalism has received limited attention by scholars. The result has been an incomplete understanding of her political and intellectual development. Drawing from First's scrapbooks, this article examines some of the themes that preoccupied her from 1947–1950 while situating her work within the broader political context. Her journalism played a crucial role in chronicling resistance to segregationist policies in the pre-apartheid period and the role of cheap labour in capitalist development. Many of the themes that dominated her work on labour and development in Mozambique can be glimpsed in these scrapbooks.
Corrections to: “On the 𝔫-cohomology of limits of discrete series representations”
Authors: Soergel Wolfgang
Published: January 2015

In this note I want to point out a flaw in the argumentation of said article and explain why it has no effect on the main result. I take the opportunity to add an example.
Genome-wide analysis reveals two novel mosaic regions containing an ACME with an identical DNA sequence in the MRSA ST398-t011 and MSSA ST8-t008 isolates
Authors: Sabat Artur J. , Ilczyszyn Weronika M. , van Rijen Miranda , Akkerboom Viktoria , Sinha Bhanu , Kluytmans Jan , Miedzobrodzki Jacek , Grundmann Hajo , Friedrich Alexander W.
Published: January 2015

Objectives

The presence of the arginine catabolic mobile element (ACME) in Staphylococcus aureus has been reported to enhance the colonization of the human host. The aim of this study was to determine the genetic organization of composite islands harbouring ACME.

Methods

Two ACME-positive S. aureus isolates obtained during two different surveys conducted in the Netherlands and Poland were characterized in this study. The isolates were analysed by spa typing, DNA microarrays and whole-genome sequencing.

Results

The two isolates harboured a truncated yet fully functional ACME type II with an identical nucleotide sequence, but differed in their adjacent mobile genetic elements. The first strain was a livestock-associated ST398-t011 MRSA, which had a staphylococcal cassette chromosome mec (SCCmec) composite island composed of SCCpls adjacent to orfX followed by ACME type II and SCCmec type IVa. The second ACME-positive isolate was an ST8-t008 MSSA. Its composite island showed an SCC-like element carrying the ccrC gene followed by ACME II.

Conclusions

This is the first report of an ACME in a livestock-associated MRSA ST398. It is also the first presentation of an ACME composite island structure in an MSSA isolate. Our findings indicate an extensive mosaicism of composite islands in S. aureus, which has implications for the transmissibility among humans and thus for public health.
Impact of Parenteral Fat Composition on Cholestasis in Preterm Infants
Authors: Teng Jonas , Arnell Henrik , Bohlin Kajsa , Nemeth Antal , Fischler Björn
Published: January 2015

Objectives:

Parenteral nutrition–associated liver disease (PNALD) is frequently detected in neonatal intensive care units. Parenteral lipid emulsion (PLE) content has been implicated in its pathogenesis. We aimed to study the effect on incidence and outcome of PNALD by replacing soy‐based PLE with olive oil–based PLE in a population‐based group of preterm infants.

Methods:

All infants in Stockholm County with gestational age (GA) <30 weeks were included (n = 615). Infants who died before 28 days of age or were referred to or from other regions were excluded (n = 97). PNALD was defined as conjugated serum bilirubin ≥30 μmol/L and exceeding 20% of the total fraction on at least 2 occasions. Two different 2‐year time periods were compared: before (SOY period) and after (OLIVE period) switching PLE. For each PNALD case, 2 GA‐matched controls were randomly identified.

Results:

PNALD incidence was 14.8% (37/250) in the SOY period and 12.7% (34/268) in the OLIVE period (P = 0.52). The OLIVE infants with PNALD had more risk factors, such as lower GA and longer periods of parenteral nutrition, for developing PNALD than the SOY infants. Nevertheless, treatment during the SOY period was an independent risk factor for PNALD in logistic regression analysis.

Conclusions:

Population‐based incidence of PNALD is 1 of 7 in preterm infants with GA < 30 weeks. Changing from soy oil to olive oil–based PLE did not decrease the incidence of PNALD significantly. Olive oil–based PLE carries an equal or slightly decreased risk to develop PNALD compared with soy oil–based PLE.
Sporolactobacillus shoreae sp. nov. and Sporolactobacillus spathodeae sp. nov., two spore-forming lactic acid bacteria isolated from tree barks in Thailand
Authors: Thamacharoensuk Tanatip , Kitahara Maki , Ohkuma Moriya , Thongchul Nuttha , Tanasupawat Somboon
Published: January 2015

Two Gram-stain-positive, endospore-forming lactic acid bacteria, designated BK92T and BK117-1T, were isolated from tree barks in Thailand. Cells were catalase-negative and facultatively anaerobic rods. 16S rRNA gene sequence analysis indicated that these strains belonged to the genus

Sporolactobacillus

. Strains BK92T and BK117-1T showed the highest 16S rRNA gene sequence similarity to

Sporolactobacillus putidus

QC81-06T with 97.7 % and 97.1 % similarity, respectively. Analysis of phylogenetic relationships based on 16S rRNA and gyrB gene sequencing revealed that the positions of strains BK92T and BK117-1T were clearly separated from all related species of the genus

Sporolactobacillus

. Strains BK92T and BK117-1T had low DNA–DNA relatedness between each other and also with

S. putidus

QC81-06T and

Sporolactobacillus vineae

SL153T. The DNA G+C content of strains BK92T and BK117-1T was 46.6 mol% and 47.4 mol%, respectively. The major fatty acids of strains BK92T and BK117-1T were anteiso-C17 : 0 and anteiso-C15 : 0. They contained meso-diaminopimelic acid in cell-wall peptidoglycan and had menaquinone with seven isoprene units (MK-7) as the predominant menaquinone. Based on evidence including phenotypic, genotypic and chemotaxonomic studies, strains BK92T and BK117-1T should be classified as representatives of novel species of the genus

Sporolactobacillus

, for which the names Sporolactobacillus shoreae sp. nov. and Sporolactobacillus spathodeae sp. nov. are proposed, respectively. The type strains are BK92T ( = JCM 19541T = LMG 28365T = PCU 336T = TISTR 2234T) and BK117-1T ( = JCM 19542T = LMG 28366T = PCU 337T = TISTR 2235T).
Ponticoccus lacteus sp. nov. of the family Rhodobacteraceae, isolated from surface seawater
Authors: Yang Yujie , Sun Jia , Tang Kai , Lin Dan , Li Chenlan , Lin Yingfang
Published: January 2015

A Gram-stain-negative, rod-shaped, non-motile, aerobic bacterium, strain JL351T, was isolated from the surface seawater of the South China Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain had a close relationship with members of the genera

Ponticoccus

,

Antarctobacter

and

Sagittula

, and the closest relative was

Ponticoccus litoralis

CL-GR66T (with 96.56 % 16S rRNA gene sequence similarity). The polar lipids of strain JL351T comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminolipids, three unidentified phospholipids and an unidentified glycolipid. The predominant isoprenoid quinone was Q-10. The major fatty acids were C18 : 1ω7c (60.9 %), C18 : 0 (13.7 %), C16 : 0 (9.4 %), 11-methyl C18 : 1ω7c (4.5 %), and C12 : 1 3-OH (4.4 %). The DNA G+C content was 66.2 mol%. Based on phenotypic, phylogenetic and genotypic data, strain JL351T is considered to represent a novel species in the genus

Ponticoccus

, for which the name Ponticoccus lacteus sp. nov. is proposed. The type strain is JL351T ( = CGMCC 1.12986T = JCM 30379T).
Uruburuella testudinis sp. nov., isolated from tortoise (Testudo)
Authors: Kuhnert Peter , Thomann Andreas , Brodard Isabelle , Haefeli Willi , Korczak Bożena M.
Published: January 2015

A polyphasic taxonomic analysis was carried out on 11 uncommon Gram-stain-negative, non-motile, catalase- and oxidase-positive, but indole-negative, bacterial strains isolated from tortoises. Phenotypically and genetically they represented a homogeneous group of organisms most closely related to, but distinct from,

Uruburuella suis

. In a reconstructed 16S rRNA gene tree they clustered on a monophyletic branch next to

U. suis

with gene similarities between strains of 99.5–100 %, and of up to 98.2 % with

U. suis

. DNA–DNA hybridization indicated the organisms represented a novel species with only 40 % DNA-DNA similarity with

U. suis

. Partial sequencing of rpoB resulted in two subclusters confirming the 16S rRNA gene phylogeny; both genes allowed clear separation and identification of the novel species. Furthermore, they could be unambiguously identified by matrix-assisted laser desorption ionization time-of-flight MS, where, again, they formed a highly homogeneous cluster separate from

U. suis

and other members of the family

Neisseriaceae

. The major fatty acids were C16 : 0 and summed feature C16 : 1ω7c/iso-C15 : 0 2-OH. The DNA G+C content was 54.4 mol%. Based on phenotypic and genetic data we propose classifying these organisms as representatives of a novel species named Uruburuella testudinis sp. nov. The type strain is 07_OD624T ( = DSM 26510T = CCUG 63373T).
Taxogenomics of the order Chlamydiales
Authors: Pillonel Trestan , Bertelli Claire , Salamin Nicolas , Greub Gilbert
Published: January 2015

Bacterial classification is a long-standing problem for taxonomists and species definition itself is constantly debated among specialists. The classification of strict intracellular bacteria such as members of the order

Chlamydiales

mainly relies on DNA- or protein-based phylogenetic reconstructions because these organisms exhibit few phenotypic differences and are difficult to culture. The availability of full genome sequences allows the comparison of the performance of conserved protein sequences to reconstruct

Chlamydiales

phylogeny. This approach permits the identification of markers that maximize the phylogenetic signal and the robustness of the inferred tree. In this study, a set of 424 core proteins was identified and concatenated to reconstruct a reference species tree. Although individual protein trees present variable topologies, we detected only few cases of incongruence with the reference species tree, which were due to horizontal gene transfers. Detailed analysis of the phylogenetic information of individual protein sequences (i) showed that phylogenies based on single randomly chosen core proteins are not reliable and (ii) led to the identification of twenty taxonomically highly reliable proteins, allowing the reconstruction of a robust tree close to the reference species tree. We recommend using these protein sequences to precisely classify newly discovered isolates at the family, genus and species levels.
Idiomarina halophila sp. nov., isolated from a solar saltern sediment
Authors: Lee Jae-Chan , Kim Young-Sook , Yun Bong-Sik , Whang Kyung-Sook
Published: January 2015

A Gram-stain-negative, halophilic bacterium, designated strain BH195T, was isolated from the sediment of the solar saltern pond located in Gomso, Republic of Korea. Strain BH195T was a strictly aerobic, non-motile rod, which grew at pH 3.5–10.5 (optimum, pH 7.5), at 4–55 °C (optimum, 30 °C) and at salinities of 0.5–11 % (w/v) NaCl [optimum, 2–3 % (w/v) NaCl]. Phylogenetic analysis, based on 16S rRNA gene sequences, indicated that strain BH195T belongs to the genus

Idiomarina

, showing the highest sequence similarity to

Idiomarina salinarum

ISL-52T (97.4 %),

Idiomarina homiensis

PO-M2T (96.8 %),

Idiomarina aestuarii

KYW314T (96.7 %), and

Idiomarina tainanensis

PIN1T (96.7 %). The major cellular fatty acids of strain BH195T were iso-C11 : 0 3-OH, iso-C15 : 0 and iso-C11 : 0. The DNA G+C content was 51.3 mol% and the major respiratory quinone was ubiquinone 8. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown phospholipid. DNA–DNA relatedness between strain BH195T and

I. salinarum

KCTC 12971T was 33 %. On the basis of this polyphasic analysis, strain BH195T represents a novel species of the genus

Idiomarina

for which the name Idiomarina
halophila sp. nov. is proposed. The type strain is BH195T ( = KACC 17610T = NCAIM B 02544T).
M ethanocaldococcus bathoardescens sp. nov., a hyperthermophilic methanogen isolated from a volcanically active deep-sea hydrothermal vent
Authors: Stewart Lucy C. , Jung Jong-Hyun , Kim You-Tae , Kwon Soon-Wo , Park Cheon-Seok , Holden James F.
Published: January 2015

A hyperthermophilic methanogen, strain JH146T, was isolated from 26 °C hydrothermal vent fluid emanating from a crack in basaltic rock at Marker 113 vent, Axial Seamount in the northeastern Pacific Ocean. It was identified as an obligate anaerobe that uses only H2and CO2for growth. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain is more than 97 % similar to other species of the genusMethanocaldococcus. Therefore, overall genome relatedness index analyses were performed to establish that strain JH146Trepresents a novel species. For each analysis, strain JH146Twas most similar toMethanocaldococcussp.FS406-22, which can fix N2and also comes from Marker 113 vent. However, strain JH146Tdiffers from strain FS406-22 in that it cannot fix N2. The average nucleotide identity score for strain JH146Twas 87 %, the genome-to-genome direct comparison score was 33–55 % and the species identification score was 93 %. For each analysis, strain JH146Twas below the species delineation cut-off. Full-genome gene synteny analysis showed that strain JH146Tand strain FS406-22 have 97 % genome synteny, but strain JH146Twas missing the operons necessary for N2fixation and assimilatory nitrate reduction that are present in strain FS406-22. Based on its whole genome sequence, strain JH146Tis suggested to represent a novel species of the genusMethanocaldococcusfor which the nameMethanocaldococcusbathoardescensis proposed. The type strain is JH146T( = DSM 27223T = KACC 18232T).
TGF-β/Smad signaling through DOCK4 facilitates lung adenocarcinoma metastasis
Authors: Yu Jia-Ray , Tai Yilin , Jin Ying , Hammell Molly C. , Wilkinson J. Erby , Roe Jae-Seok , Vakoc Christopher R. , Van Aelst Linda
Published: February 2015

The mechanisms by which TGF-β promotes lung adenocarcinoma (ADC) metastasis are largely unknown. Here, we report that in lung ADC cells, TGF-β potently induces expression of DOCK4, but not other DOCK family members, via the Smad pathway and that DOCK4 induction mediates TGF-β’s prometastatic effects by enhancing tumor cell extravasation. TGF-β-induced DOCK4 stimulates lung ADC cell protrusion, motility, and invasion without affecting epithelial-to-mesenchymal transition. These processes, which are fundamental to tumor cell extravasation, are driven by DOCK4-mediated Rac1 activation, unveiling a novel link between TGF-β and Rac1. Thus, our findings uncover the atypical Rac1 activator DOCK4 as a key component of the TGF-β/Smad pathway that promotes lung ADC cell extravasation and metastasis.
Recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis ofHaemophilus influenzaeBamD and BamCD complex
Authors: Lei Jintang , Cai Xun , Ma Xiaodan , Zhang Li , Li Yuwen , Dong Xue , St Geme Joseph , Meng Guoyu
Published: February 2015

The Bam machinery, which is highly conserved from bacteria to humans, is well recognized as the apparatus responsible for the insertion and folding of most outer membrane proteins in Gram-negative bacteria. InEscherichia coli, the Bam machinery consists of five components (i.e.BamA, BamB, BamC, BamD and BamE). In comparison, there are only four partners inHaemophilus influenzae: a BamB homologue is not found in its genome. In this study, the recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis ofH. influenzaeBamD and BamCD complex are reported. The genes encoding BamC and BamD were cloned into a pET vector and expressed inE. coli. Affinity, ion-exchange and gel-filtration chromatography were used to obtain high-purity protein for further crystallographic characterization. Using the hanging-drop vapour-diffusion technique, BamD and BamCD protein crystals of suitable size were obtained using protein concentrations of 70 and 50 mg ml−1, respectively. Preliminary X-ray diffraction analysis showed that the BamD crystals diffracted to 4.0 Å resolution and belonged to space groupP212121, with unit-cell parametersa= 54.5,b= 130.5,c= 154.7 Å. The BamCD crystals diffracted to 3.8 Å resolution and belonged to space groupI212121, with unit-cell parametersa= 101.6,b= 114.1,c= 234.9 Å.
Crystal structure of bis(tetraphenylphosphonium) bis(cyanido-κC)(29H,31H-tetrabenzo[b,g,l,q]porphinato-κ4N29,N30,N31,N32)ferrate(II) acetone disolvate
Authors: Nishi Miki , Matsuda Masaki , Hoshino Norihisa , Akutagawa Tomoyuki
Published: January 2015

The crystal structure of the title compound, (C24H20P)2[Fe(C36H20N4)(CN)2]·2C3H6O, is constructed from a tetrahedral Ph4P+(tetraphenylphosphonium) cation, one [Fe(tbp)(CN)2]2−anion (tbp = tetrabenzoporphyrin in its doubly deprotonated form), located on a centre of inversion, and an acetone molecule as crystallization solvent. Since the molecular structure of theM(tbp) moiety is insensitive to the kind of metal ion and its oxidation state, bond lengths and angles in the [Fe(tbp)(CN)2]2−anion are similar to those in otherM(tbp) compounds. The Fe2+ion, located on a centre of inversion, is coordinated by four N atoms of tpb in the equatorial plane and by two C atoms of the cyanide anion at axial positions in a slightly distorted octahedral configuration. The packing is stabilized by C—H...N interactions between the Ph4P+cation and the CN−ligand of the [Fe(tbp)(CN)2]2−anion, and by C—H...π interactions between the Ph4P+cation, acetone solvent molecules and the [Fe(tbp)(CN)2]2−anion.
Defective co-creation
Authors: Greer Dominique A.
Published: January 2015

Purpose

– This study aims to explore the scope of consumers’ defective co-creation behaviour in professional service encounters. One of the founding premises of service-dominant logic (Vargo and Lusch, 2004, 2008) is that consumers co-create the value they derive from service encounters. In practice, however, dysfunctional consumer behaviour can obstruct value co-creation. Extant research has not yet investigated consumers’ defective co-creation behaviour in highly relational services, such as professional services, that are heavily reliant on co-creation.

Design/methodology/approach

– To investigate defective co-creation in professional services, 164 critical incidents were collected from 38 health-care and financial service providers using the critical incident technique within semi-structured, in-depth interviews. Thematic coding was used to identify emergent themes and patterns of consumer behaviour.

Findings

– Thematic coding resulted in a comprehensive typology of consumers’ defective co-creation behaviour that both confirms the prevalence of previously identified dysfunctional behaviours (e.g. verbal abuse and physical aggression) and identifies two new forms of consumer misbehaviour: underparticipation and overparticipation. Further, these behaviours can vary, escalate and co-occur during service encounters.

Originality/value

– Both underparticipation and overparticipation are newly identified forms of defective co-creation that need to be examined within the broader framework of service-dominant logic (SDL).
N-person grey game
Authors: Kose Erkan , Forrest Jeffrey Yi-Lin
Published: January 2015

Purpose

– One important assumption in the conventional cooperative game theory is that payoffs are assumed to be deterministic. In terms of the players’ cognitive ability of the realistic world, this is a very strict assumption. The classical game theory can find no way out when a particular game circumstance involves uncertainty, such as limited knowledge, small sample, and inadequate information, the payoff values of the game can only be described with interval grey numbers. The paper aims to discuss these issues.

Design/methodology/approach

– In this study the concept of N-person grey games is proposed in which payoffs are represented with interval grey numbers opposed to the classical game theory. A straight forward solution methodology is submitted compatible to grey numbers. Then, a currency war between anonymous countries is handled and modeled as an N-Person grey game. A generic currency war scenario is developed to follow the proposed solution procedure thoroughly.

Findings

– Based on the outcomes of this work, the authors can say that N-person grey game is an expansion of the classical N-person game under uncertain grey information and can be applied in more complex and uncertain environments, such as those seen in complicated currency warfare.

Originality/value

– This study combines the grey system theory with the classic N-person game theory and sets up the N-person grey game with grey payoff functions. Based on the grey number operating methods, the grey linear programming algorithm is established to calculate and distribute benefits to the players. In this respect this study has the feature of being the pioneer in the N-person grey game area.