bluuebunny/crossref_metadata_2025 huggingface dataset:
An axially propagating two-stream instability in the Hall thruster plasma
Authors: Tsikata S. , Cavalier J. , Héron A. , Honoré C. , Lemoine N. , Grésillon D. , Coulette D.
Published: July 2014

Collective Thomson scattering experiments reveal the presence of high-frequency, axial electron density fluctuations at millimetric wavelengths in the Hall thruster plasma. The properties of these fluctuations are investigated experimentally and via linear kinetic theory. The relative drift of electrons and ions in the axial direction is found to be insufficient to cause excitation of the observed mode. Instead, the mode is determined to be a two-stream instability arising due to the velocity difference between singly and doubly charged ion populations in the plume.
Millimeter wave detection via Autler-Townes splitting in rubidium Rydberg atoms
Authors: Gordon Joshua A. , Holloway Christopher L. , Schwarzkopf Andrew , Anderson Dave A. , Miller Stephanie , Thaicharoen Nithiwadee , Raithel Georg
Published: July 2014

In this paper, we demonstrate the detection of millimeter waves via Autler-Townes splitting in 85Rb Rydberg atoms. This method may provide an independent, atom-based, SI-traceable method for measuring mm-wave electric fields, which addresses a gap in current calibration techniques in the mm-wave regime. The electric-field amplitude within a rubidium vapor cell in the WR-10 wave guide band is measured for frequencies of 93.71 GHz and 104.77 GHz. Relevant aspects of Autler-Townes splitting originating from a four-level electromagnetically induced transparency scheme are discussed. We measured the E-field generated by an open-ended waveguide using this technique. Experimental results are compared to a full-wave finite element simulation.
Temperature and concentration dependent magnetic properties of epitaxial Fe1−xCrx-alloy films in the high Cr-concentration regime
Authors: Brüssing F. , Abrudan R. , Zabel H.
Published: July 2014

Soft magnetic materials with a Curie temperature (Tc) close to room temperature are suitable candidates for device applications and for more fundamental aspects of magnetism. Promising candidates are Fe1−xCrx-alloys with a Fe concentration of about 25%–35%. We have grown by molecular beam epitaxy methods a number of epitaxial Fe1−xCrx alloys on MgO[100] and MgO[110] substrates, and we report on their structural and magnetic properties in this concentration range, including the dependence of the Curie temperature (Tc) on the concentration, the magnetocrystalline anisotropy, and the development of the magnetic moment.
Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure
Authors: Yan Xiaozhi , Ren Xiangting , He Duanwei , Chen Bin , Yang Wenge
Published: July 2014

Mechanical properties and phase transition often show quite large crystal size dependent behavior, especially at nanoscale under high pressure. Here, we have investigated Ho2O3 nanocrystals with in-situ x-ray diffraction and Raman spectroscopy under high pressure up to 33.5 GPa. When compared to the structural transition routine cubic -> monoclinic -> hexagonal phase in bulk Ho2O3 under high pressure, the nano-sized Ho2O3 shows a much higher onset transition pressure from cubic to monoclinic structure and followed by a pressure-induced-amorphization under compression. The detailed analysis on the Q (Q = 2π/d) dependent bulk moduli reveals the nanosized Ho2O3 particles consist of a clear higher compressible shell and a less compressible core. Insight into these phenomena shed lights on micro-mechanism studies of the mechanical behavior and phase evolution for nanomaterials under high pressure, in general.
Discovering low-permittivity materials: Evolutionary search for MgAl2O4 polymorphs
Authors: Xie Congwei , Zeng Qingfeng , Oganov Artem R. , Dong Dong
Published: July 2014

Low-permittivity ceramics for use as microwave band window materials must have good mechanical and optical characteristics. Unfortunately, most known ceramics are opaque to microwaves because of their high dielectric permittivity. Here, we present an effective theoretical method that may be helpful in the development of innovative low-permittivity materials. Using the material's permittivity as a global optimization function, we performed a crystal structure search for MgAl2O4 using an ab initio evolutionary algorithm implemented in the USPEX code. We identified four predicted MgAl2O4 polymorphs (P4¯m2, P4¯2m, Cc, and Pc) that had lower permittivities than MgAl2O4 spinel (Fd3¯m). Our results indicate that the density is not the only factor that affects permittivity. Further analysis of permittivity from the viewpoint of the underlying structures shows that reduced permittivity can be effectively achieved by reducing the cation coordination number. This insight will help in the discovery of materials with minimum permittivity values based on simple crystal-chemical analysis.
Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator
Authors: Mukai Y. , Hirori H. , Yamamoto T. , Kageyama H. , Tanaka K.
Published: July 2014

Excitation of antiferromagnetic resonance (AFMR) in a HoFeO3 crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.
The ionization rate under a general magnetic field for microwave breakdown
Authors: Wang Huihui , Meng Lin , Liu Dagang , Liu Laqun
Published: July 2014

The ionization rate under an extra magnetic field is studied by theory and particle-in-cell/Monte Carlo Collision simulations. The result shows that a magnetic field always decreases the ionization rate if 3ω < υm, while it may increase the ionization rate if 3ω > υm. The effect of the magnetic field on the ionization rate fades away when the angle between the magnetic field and the electric filed approaches to zero. Furthermore, the peak ionization rate among different magnetic fields is almost independent of ω. This peak ionization rate is in direct proportion to the gas pressure in the low pressure region, while it is about in inverse proportion to the gas pressure in the high pressure region.
Angular dependent ferromagnetic resonance analysis in a single micron sized cobalt stripe
Authors: Schoeppner C. , Wagner K. , Stienen S. , Meckenstock R. , Farle M. , Narkowicz R. , Suter D. , Lindner J.
Published: July 2014

We demonstrate how planar microresonators (PMRs) can be utilized to investigate the angular dependent magnetic resonance response of single magnetic nanostructures. In contrast to alternative detection schemes like electrical or optical detection, the PMR approach provides a classical means of investigating the high frequency dynamics of single magnetic entities, enabling the use of well-established analysis methods of ferromagnetic resonance (FMR) spectroscopy. To demonstrate the performance of the PMR-based FMR setup for angular dependent measurements, we investigate the microwave excited magnons in a single Co stripe of 5 × 1 × 0.02 μm3 and compare the results to micromagnetic simulations. The evolution of excited magnons under rotation of one individual stripe with respect to a static magnetic field is investigated. Besides quasi uniform excitations, we observe magneto-static as well as localized excitations. We find a strong influence of inhomogeneous dynamic and static demagnetizing fields for all modes.
Electronic structure and thermoelectric properties of orthorhombic SrLiAs
Authors: Guo Li Bin , Wang Yuan Xu , Yan Yu Li , Yang Gui , Yang Jue Ming , Feng Zhen Zhen
Published: July 2014

The electronic structure and the transport properties of orthorhombic SrLiAs were investigated using first-principles calculations and the semiclassical Boltzmann theory. It is found that the electrical conductivity along the y-direction is higher than those along other two directions, which is most likely originated from the covalent ladder-like structure formed by the Li and As atoms. Moreover, the transport properties of n-type SrLiAs are better than those of p-type one, due to the large band dispersion along the y-direction near the Fermi level. Further, the value of power factor with respect to relaxation time achieves 9.2 × 1011 W K−2 m−1 s−1 for n-type SrLiAs along the y-direction at 1000 K with an optimal carrier concentration of 6.5 × 1020 cm−3. The obtained minimum lattice thermal conductivity is comparable to those of other Zintl phase compounds.
Impact of dislocations and dangling bond defects on the electrical performance of crystalline silicon thin films
Authors: Steffens S. , Becker C. , Amkreutz D. , Klossek A. , Kittler M. , Chen Y.-Y. , Schnegg A. , Klingsporn M. , Abou-Ras D. , Lips K. , Rech B.
Published: July 2014

A wide variety of liquid and solid phase crystallized silicon films are investigated in order to determine the performance limiting defect types in crystalline silicon thin-film solar cells. Complementary characterization methods, such as electron spin resonance, photoluminescence, and electron microscopy, yield the densities of dangling bond defects and dislocations which are correlated with the electronic material quality in terms of solar cell open circuit voltage. The results indicate that the strongly differing performance of small-grained solid and large-grain liquid phase crystallized silicon can be explained by intra-grain defects like dislocations rather than grain boundary dangling bonds. A numerical model is developed containing both defect types, dislocations and dangling bonds, describing the experimental results.
Modeling the Sociospatial Constraints on Land-Use Change: The Case of Periurban Sprawl in the Greater Boston Region
Authors: McCauley Stephen M , Rogan John , Murphy James T , Turner Billie L , Ratick Samuel
Published: July 2014

Land-use-change drivers related to institutional dynamics, including historical path dependencies and political dynamics associated with urban land transformation, are difficult to relate to specific spatial locations and thus are not easily included in spatial models of urban land-use change. In this paper we describe a land-use model with variables representing such institutional dynamics in the Greater Boston region, a metropolitan area characterized by periurban sprawl, for the period 1985–99. An aggregate land-use model is developed at the municipal level, based on a narrative analysis drawn from in-depth interviews with town planners, state officials, and land developers, to explain land-development patterns documented over that study period using aerial photography. Explanatory variables, including town financial variables, school quality measures, and spatial variables associated with access and location, are linked to land-change outcomes through the selection environment framework, a framework borrowed from economic geography to describe how regional growth patterns are shaped by locally specific institutional, market, and spatial contexts that constrain individual land-use decision makers. Results of the analysis suggest that institutional dynamics associated with housing values and associated tax revenues, educational expenditures, and exclusive zoning practices significantly explain municipal land-use change in the suburban or periurban context.
Spatial Position Influences Perception of Slope from Graphs
Authors: Parrott Stacey , Guzman-Martinez Emmanuel , Ortega Laura , Grabowecky Marcia , Huntington Mark D , Suzuki Satoru
Published: July 2014

We routinely examine linear trends from bar graphs and scatterplots while taking a science class, attending a business presentation, or reading a magazine article. Graphs are placed in different positions on a page or a presentation slide for aesthetic considerations. However, because left and right positions tend to be associated with lower and higher values in the conventional depiction of numerical values, we hypothesized that the perception of positive and negative slopes may be influenced by the placement of a graph. Using a visual search task, with each display containing four bar graphs or scatterplots (one per quadrant), we have demonstrated that the detection of a negative slope is selectively slowed in the upper-right quadrant (for both bar graphs and scatterplots), whereas the detection of a positive slope is selectively slowed in the upper-left quadrant (for bar graphs only). These results suggest that an upper-right position is incompatible with perceiving negative slopes and an upper-left position is incompatible with perceiving positive slopes. Although the origin of these specific associations is unclear, our results have implications for where to place a graph depending on the slope it displays.
Effects of 25-hydroxyvitamin D3 on localisation and extent of gastrointestinal calcium absorption in dairy cattle
Authors: Oehlschlaeger V. , Wilkens M. , Schroeder B. , Daenicke S. , Breves G.
Published: July 2014

The combination of 25-hydroxyvitamin D3 (25-OHD3) and a diet negative in dietary cation anion difference (DCAD) has recently been shown to have beneficial effects on peripartal calcium (Ca) homeostasis in dairy cows. To further elucidate the underlying mechanisms, it was the aim of the experiments to investigate the effects of 25-OHD3 in combination with DCAD values about –70 meq/kg DM on pre-duodenal and overall gastrointestinal Ca absorption. A group of six ruminally fistulated lactating cows equipped with a cannula in the proximal duodenum were assigned to three dietary treatments (Control diet, anionic salts, anionic salts +25-OHD3) of 5 weeks each. Urine and faeces were collected quantitatively and flow of duodenal contents was calculated by applying chromium oxide. Blood samples were taken at regular intervals. Treatment with anionic salts and 25-OHD3 resulted in an increased Ca net absorption from the total gastrointestinal tract, which was mainly due to respective increases in intestinal Ca absorption. Furthermore, anionic salts and 25-OHD3-treated animals had significantly higher plasma phosphate concentrations and lower plasma levels of CrossLaps and the overall net absorption of phosphorus was significantly higher in these animals. From these data, it can be concluded that anionic salts in combination with 25-OHD3 positively influence the overall net Ca and phosphorus absorption, which is obviously associated with a reduced mobilisation of bone minerals as indicated by decreases in plasma CrossLaps concentrations.
The nexus between nutrient metabolism, oxidative stress and inflammation in transition cows
Authors: Sordillo L. M. , Mavangira V.
Published: July 2014

Increased incidence of several economically important diseases (i.e. mastitis, metritis, displaced abomasum and ketosis) causes significant animal welfare problems and production losses in transition dairy cattle and decreases the availability of safe and nutritious food for a growing global population. A major underlying factor responsible for the development of transition cow disorders is metabolic stress, which occurs when cows fail to adapt physiologically to an increase in nutrient requirements needed for parturition and the onset of copious milk synthesis and secretion. Metabolic stress can be characterised as resulting from the combined effects of altered nutrient metabolism, dysfunctional inflammatory responses, and oxidative stress. Together, these factors form destructive feedback loops that exacerbate metabolic stress and cause health disorders in transition cows. A better understanding of how nutrition and immunology interact to influence metabolic stress will facilitate the development of control programs to improve transition cow health. The ability to detect signs of metabolic stress early enough in the dry period to implement needed management adjustments before calving will be the key to successful monitoring and intervention programs.
A call to action: exercise as treatment for patients with mental illness
Authors: Stanton Robert , Rosenbaum Simon , Kalucy Megan , Reaburn Peter , Happell Brenda
Published: July 2014

Mental illness affects the lives of a significant number of Australians. In addition to pharmacological and psychological interventions, exercise has demonstrated benefits for people with mental illness including symptom reduction, improved cardiovascular risk profile and improved physical capacity. Unfortunately, evidence shows that clinician-delivered exercise advice is not routinely offered. This is despite patient acceptability for exercise. This article summarises the recent evidence supporting the prescription of exercise for people with mental illness and offers a model incorporating basic exercise prescription, and referral pathways for specialised advice. Current exercise prescription patterns for people with mental illness may not meet patient expectations; therefore, clinicians should consider exercise referral schemes to increase the accessibility of interventions for people with a mental illness.
Chapter 2. Revisiting stylistic fronting in Old Spanish
Authors: Fischer Susann
Published: July 2014

The aim of this paper is twofold: First, data will be presented showing that Stylistic Fronting, i.e. the movement of a past participle, an adjective or an infinitive in front of the finite verb, was productive in Old Spanish. Second, I will argue that Stylistic Fronting in Old Spanish had a semantic impact, like other left-dislocated or fronted elements in the Old Romance languages. More precisely I will show that in contrast to what has often been claimed with respect to Icelandic (cf. Holmberg 2005, among many others), Stylistic Fronting in Old Spanish is not a mere phonological displacement, but instead represents a movement that takes place in narrow syntax.
Motivating language teachers
Authors: Kubanyiova Maggie
Published: July 2014

Recent theorising in research on language teachers’ conceptual change has suggested that transforming language classrooms into engaging learning environments begins with teachers’ vision (Kubanyiova 2012). This chapter considers the significance of this finding through the lens of practical proposals for motivating language teachers’ deep reflection on their praxis. Situating the discussion in the wider domain of language teacher cognition research, this chapter adopts a theoretical framework of language teachers’ possible selves and outlines three key processes involved in inspiring language teachers’ vision: the teachers’ reflection on the who (i.e. the person doing the teaching), engagement with the why (i.e. the bigger purposes guiding language teachers’ work), and the construction of the image (i.e. a visual representation of desired teaching selves).
Conversational input to bilingual children
Authors: Ervin-Tripp Susan M.
Published: July 2014

All children learn from conversational input, including children who have simultaneous or successive acquisition of several languages in childhood. Partners who stimulate speech by asking questions, responding, and expanding a child’s utterances can accelerate learning at all levels of language, in addition to scaffolding the development of speech acts, speech events, social styles and appropriate code-switching. In family bilingualism with a person dichotomy, the frequency of conversation and the instructional style of each parent can affect the rate of acquisition. Bilingualism in minority languages is most successful when parents maintain a language different from the community, so there is a place dichotomy. Children whose second language is acquired in school can become fully bilingual but there is wide variation in acquisition time.
Social environments shape children’s language experiences, strengthening language processing and building vocabulary
Authors: Weisleder Adriana , Fernald Anne
Published: July 2014

How does language experience influence the development of language skills known to be critical for academic success? In this chapter, we build on a long history of research examining sources of variability in children’s lexical development, and offer a new perspective that focuses on the development of efficiency in real-time language processing. Examining origins of individual differences in language proficiency, we review new research showing that the amount and quality of child-directed speech in infancy contributes to the development of language processing skills, which in turn facilitate vocabulary growth. These findings reveal that early language experience can have cascading effects for later learning and school success.
The interactional context of language learning in Tzeltal
Authors: Brown Penelope
Published: July 2014

This paper addresses the theories of Eve Clark about how children learn word meanings in western middle-class interactional contexts by examining child language data from a Tzeltal Maya society in southern Mexico where interaction patterns are radically different. Through examples of caregiver interactions with children 12-30 months old, I ask what lessons we can learn from how the details of these interactions unfold in this non-child-centered cultural context, and specifically, what aspects of the Tzeltal linguistic and interactional context might help to focus children’s attention on the meanings and the conventional forms of words being used around them.
Conversation and language acquisition
Authors: Veneziano Edy
Published: July 2014

Conversational exchanges have unique properties that have a great potential for language acquisition such as the motivation to communicate, information about language meanings and structures, and the construction of new ways of expression. Results from the literature and from new data analyses show that conversational exchanges have both immediate and long-term effects. Two properties are considered here to have particularly great learning potential. One is the facilitated access to unities of meaning underlying the successive transformations in utterance shapes, cognitively analogous to the discovery of physical and logico-mathematical invariances under the transformations of shape and configuration. The other is the co-construction of sequences that foreshadow behaviors still beyond the individual child’s present capacities.
Emergent clause-combining in adult-child interactional contexts
Authors: Berman Ruth A. , Lustigman Lyle
Published: July 2014

The study analyzes early clause-combining (CC) complex syntax of three Hebrew-acquiring girls in self-initiated autonomous constructions compared to three types of interlocutor-supported contexts – by means of Affirmations (encouraging comments), Scaffolding (structural prompts), and Co-Construction (adult-child clause-combining adjacency pairs). Two of the girls show a marked rise in self-initiated use of explicitly-marked canonical CC constructions along with a concurrent increase in reliance on interlocutor-supported contexts. The third child, who progressed more slowly in producing such autonomous CC constructions, also received relatively little supportive input overall. These findings for an increase in canonical CC usage together with a rise in reliance on supportive contexts suggest that interactive contexts play a role in advancing the consolidation of early complex syntax.
Intermediate geographic range facilitates speciation in European tree species
Authors: López-Villalta Julián Simón
Published: July 2014

The possible influence of geographic range size on speciation remains a controversial subject in evolutionary ecology, with theory and data supporting positive, negative and bell-shaped relationships between speciation probability and ancestor range size. In this study, a surrogate of the speciation-range size relationship of extant European tree species (22 genera, 11 families) is obtained by comparing the range-size distribution of candidate ancestors (i.e.species which are thought to have originated new species) with that of relatives, controlling phylogenetic inertia and macroecological sampling bias. In this comparison, species range size is measured qualitatively using six categories. The candidate ancestors included seem to have speciated mainly through allopatric speciation, with fewer instances of hybridogenesis by allopolyploidy. The results show that speciation is significantly facilitated for species with intermediate range size. In the European tree flora, this pattern could be the result of multiple causes, including intermediate dispersal ability at these ranges. Descendant tree species tend to have narrow geographic ranges, a trend which arguably comes from limited dispersal ability in this case. Low dispersal ability could be common in new species as a consequence of widespread adaptation to stable habitats isolated by geographic barriers (“island habitats”) during allopatric speciation. This mechanism could be widespread among regional biotas and would facilitate narrow ranges in new species. This would provide a simple explanation to the observed abundance of narrow ranges in most macroecological species-range size distributions.
Depth use and migratory behaviour of homing Atlantic salmon (Salmo salar) in Scottish coastal waters
Authors: Godfrey Jason D. , Stewart David C. , Middlemas Stuart J. , Armstrong John D.
Published: July 2014

Knowledge of swimming depths and migration routes of homing Atlantic salmon in open coastal zones is urgently required to inform decisions on managing the species, e.g. for the sustainable development of marine renewable energy. In May–June 2013, pop-up satellite tags programmed to detach from fish after 1–10 d were fitted to 50 adult salmon on the northern coast of Scotland. Most of the tags returned water depth recorded at regular intervals (n = 47) and gave a geographic location following detachment (n = 44). In general, salmon were found near the surface during the study, with the median number of records at 0–5 m depth ranging from 72 to 85%, depending on the extent of known potential systematic bias. Depth use varied among individuals (8–100% at 0–5 m) and cluster analysis suggested that the sample of fish could be split into two groups, representing different patterns of depth use. These clusters were also associated with pop-up location. There was a small but significant increase in recorded depth at night compared with during the day, contrasting with findings of salmon at sea in other contexts. The mean maximum dive depth was 64 m (range 13–118 m), of similar order to the likely available water column depth. These results suggest that salmon will potentially interact with man-made obstacles, e.g. renewable energy generators, throughout the water column and particularly in surface waters.
A temporary earth co-orbital linked to interplanetary field enhancements
Authors: Connors M. , Russell C. T. , Lai H. R.
Published: July 2014

Near-Earth asteroid 138175 (2000 EE104) will soon be temporarily resonant with Earth, but has a much longer residence in an orbit which features a trapping behaviour with frequent Earth and Venus encounters. The object has been identified as a possible source of material for interplanetary field enhancements, a magnetic phenomenon in the solar wind inferred to be due to dust arising from secondary collisions with 10-m scale objects injected into its path. Its horseshoe libration will be reversed by a very close encounter with Venus in 2251 CE. We characterize the orbit of this asteroid, model the dispersion of the primary collision products along its path, and discuss the non-gravitational motion of secondary dust in the solar wind.
Deinococcus
phoenicis sp. nov., an extreme ionizing-radiation-resistant bacterium isolated from the Phoenix Lander assembly facility
Authors: Vaishampayan Parag , Roberts Anne Hayden , Augustus Angela , Pukall Rüdiger , Schumann Peter , Schwendner Petra , Mayilraj Shanmugam , Salmassi Tina , Venkateswaran Kasthuri
Published: July 2014

A bacterial strain, designated 1P10MET, which was resistant to extreme doses of ionizing radiation, pale-pink, non-motile, and a tetrad-forming coccoid was isolated from a cleanroom at the Kennedy Space Center, where the Phoenix spacecraft was assembled. Strain 1P10MET showed optimum growth at 30 °C, with a pH range for growth of 6.5–9.0 and was highly sensitive to sodium chloride, growing only in medium with no added NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 1P10MET represents a novel member of the genus

Deinococcus

, with low sequence similarities (<93.5 %) to recognized species of the genus

Deinococcus

. The predominant cellular fatty acid was C15 : 1ω6c. This novel strain exhibits extreme resistance to gamma radiation (D10 >8 kGy) and UV (D10 >1000 Jm−2). The results of our polyphasic taxonomic analyses suggest that strain 1P10MET represents a novel species of the genus

Deinococcus

, for which the name Deinococcus
phoenicis sp. nov. is proposed. The type strain is 1P10MET ( = NRRL B-59546T = DSM 27173T).
Undibacterium squillarum sp. nov., isolated from a freshwater shrimp culture pond
Authors: Sheu Shih-Yi , Lin Yang-Shun , Chen Jhen-Ci , Kwon Soon-Wo , Chen Wen-Ming
Published: July 2014

A bacterial strain designated CMJ-15T was isolated from a freshwater shrimp culture pond in Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain CMJ-15T were facultatively anaerobic, Gram-stain-negative and motile by a single polar flagellum and formed light-yellow colonies. Growth occurred at 20–40 °C (optimum, 25–30 °C), with 0–0.7 % NaCl (optimum, 0–0.2 %) and at pH 5.0–9.0 (optimum, pH 6.0–7.0). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain CMJ-15T belonged to the genus

Undibacterium

and its closest neighbour was

Undibacterium oligocarboniphilum

EM 1T, with sequence similarity of 96.3 %. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major cellular hydroxy fatty acid was C10 : 0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The polyamine profile was composed of the major compound putrescine and moderate amounts of 2-hydroxyputrescine. The major respiratory quinone was Q-8 and the DNA G+C content was 52.2 mol%. On the basis of these phylogenetic and phenotypic data, strain CMJ-15T should be classified as representing a novel species, for which the name Undibacterium squillarum sp. nov. is proposed. The type strain is CMJ-15T ( = BCRC 80404T = LMG 26892T = KCTC 23917T).
Hierarchical management of carbon sources is regulated similarly by the CbrA/B systems in Pseudomonas aeruginosa and Pseudomonas putida
Authors: Valentini Martina , García-Mauriño Sofía M. , Pérez-Martínez Isabel , Santero Eduardo , Canosa Inés , Lapouge Karine
Published: July 2014

The CbrA/B system in pseudomonads is involved in the utilization of carbon sources and carbon catabolite repression (CCR) through the activation of the small RNAscrcZinPseudomonas aeruginosa, andcrcZandcrcYinPseudomonas putida. Interestingly, previous works reported that the CbrA/B system activity inP. aeruginosaPAO1 andP. putidaKT2442 responded differently to the presence of different carbon sources, thus raising the question of the exact nature of the signal(s) detected by CbrA. Here, we demonstrated that the CbrA/B/CrcZ(Y) signal transduction pathway is similarly activated in the twoPseudomonasspecies. We show that the CbrA sensor kinase is fully interchangeable between the two species and, moreover, responds similarly to the presence of different carbon sources. In addition, a metabolomics analysis supported the hypothesis that CCR responds to the internal energy status of the cell, as the internal carbon/nitrogen ratio seems to determine CCR and non-CCR conditions. The strong difference found in the 2-oxoglutarate/glutamine ratio between CCR and non-CCR conditions points to the close relationship between carbon and nitrogen availability, or the relationship between the CbrA/B and NtrB/C systems, suggesting that both regulatory systems sense the same sort or interrelated signal.
No evidence that sex and transposable elements drive genome size variation in evening primroses
Authors: Ågren J Arvid , Greiner Stephan , Johnson Marc TJ , Wright Stephen I
Published: July 2014

Genome size varies dramatically across species, but despite an abundance of attention there is little agreement on the relative contributions of selective and neutral processes in governing this variation. The rate of sexual reproduction can potentially play an important role in genome size evolution because of its effect on the efficacy of selection and transmission of transposable elements. Here, we used a phylogenetic comparative approach and whole genome sequencing to investigate the contribution of sex and transposable element content to genome size variation in the evening primrose (Oenothera) genus. We determined genome size using flow cytometry from 30Oenotheraspecies of varying reproductive system and find that variation in sexual/asexual reproduction cannot explain the almost two-fold variation in genome size. Moreover, using whole genome sequences of three species of varying genome sizes and reproductive system, we found that genome size was not associated with transposable element abundance; instead the larger genomes had a higher abundance of simple sequence repeats. Although it has long been clear that sexual reproduction may affect various aspects of genome evolution in general and transposable element evolution in particular, it does not appear to have played a major role in the evening primroses.
Concerning RNA-Guided Gene Drives for the Alteration of Wild Populations
Authors: Esvelt Kevin M. , Smidler Andrea L. , Catteruccia Flaminia , Church George M.
Published: July 2014

Gene drives may be capable of addressing ecological problems by altering entire populations of wild organisms, but their use has remained largely theoretical due to technical constraints. Here we consider the potential for RNA-guided gene drives based on the CRISPR nuclease Cas9 to serve as a general method for spreading altered traits through wild populations over many generations. We detail likely capabilities, discuss limitations, and provide novel precautionary strategies to control the spread of gene drives and reverse genomic changes. The ability to edit populations of sexual species would offer substantial benefits to humanity and the environment. For example, RNA-guided gene drives could potentially prevent the spread of disease, support agriculture by reversing pesticide and herbicide resistance in insects and weeds, and control damaging invasive species. However, the possibility of unwanted ecological effects and near-certainty of spread across political borders demand careful assessment of each potential application. We call for thoughtful, inclusive, and well-informed public discussions to explore the responsible use of this currently theoretical technology.
Modulation of olfactory bulb network activity by serotonin: synchronous inhibition of mitral cells mediated by spatially localized GABAergic microcircuits
Authors: Schmidt Loren J. , Strowbridge Ben W.
Published: July 2014

Although inhibition has often been proposed as a central mechanism for coordinating activity in the olfactory system, relatively little is known about how activation of different inhibitory local circuit pathways can generate coincident inhibition of principal cells. We used serotonin (5-HT) as a pharmacological tool to induce spiking in ensembles of mitral cells (MCs), a primary output neuron in the olfactory bulb, and recorded intracellularly from pairs of MCs to directly assay coincident inhibitory input. We find that 5-HT disynaptically depolarized granule cells (GCs) only slightly but robustly increased the frequency of inhibitory postsynaptic inhibitory currents in MCs. Serotonin also triggered more coincident IPSCs in pairs of nearby MCs than expected by chance, including in MCs with truncated apical dendrites that lack glomerular synapses. That serotonin-triggered coincident inhibition in the absence of elevated GC somatic firing rates suggested that synchronized MC inhibition arose from glutamate receptor-mediated depolarization of GC dendrites or other (non-GC) interneurons outside the glomerular layer. Tetanic stimulation of GCL afferents to GCs triggered robust GC spiking, coincident inhibition in pairs of MCs, and recruited large-amplitude IPSCs in MCs. Enhancing neurotransmission through NMDARs by lowering the external Mg2+ concentration also increased inhibitory tone onto MCs but failed to promote synchronized inhibition. These results demonstrate that coincident MC inhibition can occur through multiple circuit pathways and suggests that the functional coordination between different GABAergic synapses in individual GCs can be dynamically regulated.
Prefrontal consolidation supports the attainment of fear memory accuracy
Authors: Vieira Philip A. , Lovelace Jonathan W. , Corches Alex , Rashid Asim J. , Josselyn Sheena A. , Korzus Edward
Published: July 2014

The neural mechanisms underlying the attainment of fear memory accuracy for appropriate discriminative responses to aversive and nonaversive stimuli are unclear. Considerable evidence indicates that coactivator of transcription and histone acetyltransferase cAMP response element binding protein (CREB) binding protein (CBP) is critically required for normal neural function. CBP hypofunction leads to severe psychopathological symptoms in human and cognitive abnormalities in genetic mutant mice with severity dependent on the neural locus and developmental time of the gene inactivation. Here, we showed that an acute hypofunction of CBP in the medial prefrontal cortex (mPFC) results in a disruption of fear memory accuracy in mice. In addition, interruption of CREB function in the mPFC also leads to a deficit in auditory discrimination of fearful stimuli. While mice with deficient CBP/CREB signaling in the mPFC maintain normal responses to aversive stimuli, they exhibit abnormal responses to similar but nonrelevant stimuli when compared to control animals. These data indicate that improvement of fear memory accuracy involves mPFC-dependent suppression of fear responses to nonrelevant stimuli. Evidence from a context discriminatory task and a newly developed task that depends on the ability to distinguish discrete auditory cues indicated that CBP-dependent neural signaling within the mPFC circuitry is an important component of the mechanism for disambiguating the meaning of fear signals with two opposing values: aversive and nonaversive.
Crystal structure of bis[3-methoxy-17β-estra-1,3,5(10)-trien-17-yl] oxalate
Authors: Harrison William T. A. , Nahar Lutfun , Turner Alan B.
Published: July 2014

In the title compound, C40H50O6, a symmetrical steroid oxalate diester, the dihedral angle between the CO2planes of the oxalate linker is 61.5 (5)° and the C—C bond length is 1.513 (6) Å. The steroidB,CandDrings adopt half-chair, chair and envelope conformations, respectively, in both halves of the molecule, which adopts an overall shallow V-shaped conformation. In the crystal, molecules are linked by weak C—H...O interactions, forming a three-dimensional network.
Crystal structure of [NiHg(SCN)4(CH3OH)2]n
Authors: Weil Matthias , Häusler Thomas
Published: July 2014

The title compound,catena-poly[[bis(methanol-κO)nickel(II)]-di-μ-thiocyanato-κ4N:S-mercurate(II)-di-μ-thiocyanato-κ4N:S], was obtained from a gel-growth method using tetramethoxysilane as gelling agent. The crystal structure is composed of rather regular HgS4tetrahedra (point group symmetry .2.) andtrans-NiN4O2octahedra (point group symmetry 2..) that are linked through thiocyanato bridges into a three-dimensional framework. The methanol molecules coordinateviathe O atom to the Ni2+cations and point into the voids of this arrangement while a weak O—H...S hydrogen bond to an adjacent S atom stabilizes it.
Crystal structure oftrans-1,4-bis[(trimethylsilyl)oxy]cyclohexa-2,5-diene-1,4-dicarbonitrile
Authors: Glöcklhofer Florian , Fröhlich Johannes , Stöger Berthold , Weil Matthias
Published: July 2014

The asymmetric unit of the title compound, C14H22N2O2Si2, contains one half of the molecule, which is completed by inversion symmetry. The cyclohexa-2,5-diene ring is exactly planar and reflects the bond-length distribution of a pair of located double bonds [1.3224 (14) Å] and two pairs of single bonds [1.5121 (13) and 1.5073 (14) Å]. The tetrahedral angle between thesp3-C atom and the two neighbouringsp2-C atoms in the cyclohexa-2,5-diene ring is enlarged by about 3°.
Detecting orientational order in model systems by X-ray cross-correlation methods
Authors: Lehmkühler Felix , Grübel Gerhard , Gutt Christian
Published: July 2014

The results of a computational X-ray cross-correlation analysis (XCCA) study on two-dimensional polygonal model structures are presented. This article shows how to detect and identify the orientational order of such systems, demonstrates how to eliminate the influence of the `computational box' on the XCCA results and develops new correlation functions that reflect the sample's orientational order only. For this purpose, the dependence of the correlation functions on the number of polygonal clusters and scattering vector magnitude q is studied for various types of polygons, including mixtures of polygons and randomly placed particles. An order parameter that describes the orientational order within the sample is defined. Finally, the influence of detector noise and nonplanar wavefronts on the XCCA data is determined, both of which appear to affect the results significantly and have thus to be considered in real experiments.
Performance measures of ISO 9001 certified and non-certified manufacturing companies
Authors: Psomas Evangelos , Kafetzopoulos Dimitrios
Published: July 2014

Purpose

– The purpose of this paper is to compare ISO 9001 certified and non-certified manufacturing companies with regard to performance measures, both financial and non-financial.

Design/methodology/approach

– A research study was carried out in 140 Greek manufacturing companies by means of a questionnaire. The questionnaire was sent by e-mail and it was requested that it should be answered by a company representative. Exploratory factor analysis is applied in order to extract the latent factors of performance measures. The differences between the ISO 9001 certified and non-certified manufacturing companies are determined through non-parametric tests such as the χ2-test and the Mann-Whitney U-test.

Findings

– The ISO 9001 certified manufacturing companies significantly outperform the non-certified with regard to product quality, customer satisfaction, operational, market and financial performance. This is evident in a business environment where an economic downturn and financial crisis dominates.

Research limitations/implications

– The sub-samples of the responding ISO 9001 certified and non-certified manufacturing companies are small sized and they are limited to small- and medium-sized enterprises. The subjective character of the data collected through the company representatives involves the risk of receiving biased responses regarding the performance measures. The above limitations suggest future research recommendations.

Practical implications

– The increased performance measures of the ISO 9001 certified manufacturing companies may motivate the non-certified ones to implement the ISO 9001 standard and apply for the certification in order to increase their performance and withstand the current economic downturn and financial crisis. The present study may also stimulate manufacturing companies to adopt traditional and modern benchmarking techniques, in an additional effort to improve their businesses and competitiveness.

Originality/value

– The present study compares performance measures of ISO 9001 certified and non-certified manufacturing companies operating under unprecedented circumstances due to the current economic downturn and financial crisis.
Extension of process mapping to identify “green waste”
Authors: R.T. White Gareth , James Peter
Published: July 2014

Purpose

– The purpose of this paper is to develop an approach to process mapping (Pmapping) that incorporates the identification of environmental wastes.

Design/methodology/approach

– The proposed extension of the PMapping technique is independently trialled by ten Industrial Engineers in manufacturing SMEs in South Wales. Interviews were conducted with each Engineer after the mapping technique was trialled, in order to understand the benefits and difficulties of using the approach.

Findings

– Integrating the identification of “green wastes” within the PMapping tool is found to be an effective way of focusing attention upon the environmental impact of activities within processes. Combining “green and lean” is also an approach that cements environmental issues into an organisation's continuous improvement efforts and can assist in it becoming part of its improvement philosophy.

Research limitations/implications

– The tool has been trialled within a limited number of small- to medium-sized manufacturing organisations. Further examination of the tool should be conducted in organisations in different business sectors utilising a range of process technologies.

Practical implications

– The proposed tool appears effective in aiding the identification of environmental wastes in manufacturing processes. It also has value in integrating environmental improvement initiatives with other process improvement initiatives.

Originality/value

– PMapping techniques are well known in the literature, and in practice, but none have been identified that incorporate the identification of environmental wastes.
An exploratory investigation of factors shaping electronic commerce practices in Iran
Authors: M. Yasin Mahmoud , Alavi Jafar , Czuchry Andrew , Shafieyoun Rasool
Published: July 2014

Purpose

– The purpose of this paper it to examine Electronic commerce (e-commerce) practices of Iranian business organizations, as a “traditional” business culture, as it compares to a “developed” business culture such as the one existing in business organizations in the USA.

Design/methodology/approach

– Executives from a sample of 50 business organizations in Iran were interviewed and asked to complete the research questions pertaining to e-commerce practices in their organizations. A factor analysis procedures with varimax rotations is used to analyze the data collected from these organizations.

Findings

– Comparing the result of this study with an earlier study on a sample of business organization in the USA shows more similarities than differences. Based on the results of the study, it appears that e-commerce practices and related technology present similar opportunities and challenges to organizations regardless of their business culture. Lack of appropriate technological hardware and software, however, is identified as a hindering factor preventing Iranian business organizations from reaching their e-commerce potentials.

Originality/value

– This research provides a rare insight into the Iranian business culture. The collection of data through personal interviews and the empirical nature of the study represent a unique opportunity to validate findings from other business cultures. This allows for a better practical understanding of the opportunities and constraints associated with e-commerce adoption.