bluuebunny/crossref_metadata_2025 huggingface dataset:
A long-term frequency stabilized deep ultraviolet laser for Mg+ ions trapping experiments
Authors: Zhang J. , Yuan W. H. , Deng K. , Deng A. , Xu Z. T. , Qin C. B. , Lu Z. H. , Luo J.
Published: December 2013

As many precision laser spectroscopy experiments require frequency stabilized lasers, development of long-term stabilized lasers is of great interest. In this work, we report long-term frequency stabilization of a 280 nm deep ultraviolet laser to a high precision wavemeter with digital servo control such that the long-term drift of the laser frequency was greatly reduced. Long-term laser frequency drift was measured with a fiber frequency comb system over 8 h. After locking, the maximum drift rate of the 280 nm laser was lowered from 576 MHz/h to 6.4 MHz/h. With proper environment control of the wavemeter, the maximum drift rate of the 280 nm laser was further lowered to less than 480 kHz/h. The locked laser system was successfully used in a Mg+ ions trapping experiment, which was also discussed in this work.
Back propagation neural network based control for the heating system of a polysilicon reduction furnace
Authors: Cheng Yuhua , Chen Kai , Bai Libing , Dai Meizhi
Published: December 2013

In this paper, the Back Propagation (BP) neural network based control strategy is proposed for the heating system of a polysilicon reduction furnace. It is applied to obtain the control signal Id, which is used to adjust the heating power through operations of the silicon core temperature, furnace temperature, silicon core voltage, and resistance of the current control cycle. With the control signal Id the polycrystalline silicon can be heated from room temperature to the required temperature smoothly and steadily. The proposed BP network applied in this paper can obtain the accurate control signal Id and achieve the precise control purpose. This paper presents the principle of the BP network and demonstrates the effectiveness of the BP network in the heating system of a polysilicon reduction furnace by combining the simulation analysis with experimental results.
Time evolution of electron flow in a model diode: Non-perturbative analysis
Authors: Rokhlenko A. , Lebowitz J. L.
Published: December 2013

Using a combination of Eulerian and Lagrangian variables we study the time evolution of the electron flow from a no-current state to a final state with the stationary current in a planar one-dimensional diode. The electrons can be injected externally or generated by the cathode via field emission governed by a current-field law. The initial zero current regime is replaced suddenly by injection or, in the case of field emission, by jumping the anode voltage from zero to a constant positive value. The case of equipotential electrodes and fixed injection is studied along with a positive anode potential. When the current is fixed externally, the approach to the stationary state goes without oscillations if the initial electron velocity is high enough and the anode can absorb the injected flow. Otherwise the accumulated space charge creates a potential barrier which reflects the flow and leads to its oscillations, but our method of analysis is invalid in such conditions. In the field emission case the flow goes to its stationary state through a train of decaying oscillations whose period is of the order of the electron transit time, in agreement with earlier studies based on perturbation techniques. Our approximate method does not permit very high cathode emissivity although the method works when the stationary current density is only about 10% smaller than the Child-Langmuir limit.
Development of a new type of high pressure calorimetric cell, mechanically agitated and equipped with a dynamic pressure control system: Application to the characterization of gas hydrates
Authors: Plantier F. , Marlin L. , Missima D. , Torré J.-P.
Published: December 2013

A novel prototype of calorimetric cell has been developed allowing experiments under pressure with an in situ agitation system and a dynamic control of the pressure inside the cell. The use of such a system opens a wide range of potential practical applications for determining properties of complex fluids in both pressurized and agitated conditions. The technical details of this prototype and its calibration procedure are described, and an application devoted to the determination of phase equilibrium and phase change enthalpy of gas hydrates is presented. Our results, obtained with a good precision and reproducibility, were found in fairly good agreement with those found in literature, illustrate the various interests to use this novel apparatus.
La-doped BaTiO3 heterostructures: Compensating the polarization discontinuity
Authors: Kumah D. P. , Yacoby Y. , Pauli S. A. , Willmott P. R. , Clarke R.
Published: December 2013

We demonstrate a route to manipulate the polarization and internal electric field of a complex oxide heterostructure using a layering sequence based on the LaAlO3-SrTiO3 interface. By combining sensitive atomic-level mapping of the structure using direct x-ray phase-retrieval methods with theoretical modeling of the electrostatic charge and polarization, we have devised a novel single-domain polar heterostructure. We find that ionic rearrangement results in strain and free energy minimization, and eliminates the polarization discontinuity leading to a two-fold increase of the spontaneous polarization towards the surface of an ultra-thin single-domain BaTiO3 film.
Theoretical and experimental study of dynamics of photoexcited carriers in GaN
Authors: Shishehchi Sara , Rudin Sergey , Garrett Gregory A. , Wraback Michael , Bellotti Enrico
Published: December 2013

We present a theoretical and experimental study of the sub-picosecond dynamics of photo-excited carriers in GaN. In the theoretical model, interaction with an external ultrafast laser pulse is treated coherently and to account for the scattering mechanisms and dephasing processes, a generalized Monte-Carlo simulation is used. The scattering mechanisms included are carrier interactions with polar optical phonons and acoustic phonons, and carrier-carrier Coulomb interactions. We study the effect of different scattering mechanisms on the carrier densities. In the case that the excitation energy satisfies the threshold for polar optical scattering, phonon contribution is the dominant process in relaxing the system, otherwise, carrier-carrier mechanism is dominant. Furthermore, we present the temperature and pulse power dependent normalized luminescence intensity. The results are presented over a range of temperatures, electric field, and excitation energy of the laser pulse. For comparison, we also report the experimental time-resolved photoluminescence studies on GaN samples. There is a good agreement between the simulation and experiment in normalized luminescence intensity results. Therefore, we show that we can explain the dynamics of the photo-excited carriers in GaN by including only carrier-carrier and carrier-phonon interactions and a relatively simple two-band electronic structure model.
Annealing control of magnetic anisotropy and phase separation in CoFe2O4-BaTiO3 nanocomposite films
Authors: Rafique Mohsin , Herklotz A. , Guo E.-J. , Roth R. , Schultz L. , Dörr K. , Manzoor Sadia
Published: December 2013

Multiferroic heteroepitaxial nanocomposite films of BaTiO3 and CoFe2O4 (CFO) have been grown by pulsed laser deposition employing alternating ablation of two ceramic targets. Films grown at temperatures between 650 °C and 710 °C contain columnar CFO grains about 10–20 nm in diameter embedded in a BaTiO3 matrix. The very strong vertical compression of these grains causes large perpendicular magnetic anisotropy. Post-growth annealing treatments above the growth temperature gradually release the compression. This allows one to tune the stress-induced magnetic anisotropy. Additionally, annealing leads to substantial enhancement of the saturation magnetization MS. Since MS of a pure CFO film remains unchanged by a similar annealing procedure, MS is proposed to depend on the volume fraction of the obtained CFO phase. We suggest that MS can be utilized to monitor the degree of phase separation in nanocomposite films.
Graphene surface emitting terahertz laser: Diffusion pumping concept
Authors: Davoyan Arthur R. , Morozov Mikhail Yu. , Popov Vyacheslav V. , Satou Akira , Otsuji Taiichi
Published: December 2013

We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50 W/cm2 terahertz power output for 100 kW/cm2 pump power at frequency around 10 THz at room temperature.
Contactless electroreflectance studies of free exciton binding energy in Zn1-xMgxO epilayers
Authors: Wełna M. , Kudrawiec R. , Kaminska A. , Kozanecki A. , Laumer B. , Eickhoff M. , Misiewicz J.
Published: December 2013

Contactless electroreflectance (CER) has been applied to study optical transitions in Zn1-xMgxO layers with magnesium concentration ≤44%. CER resonances related to free exciton and band-to-band transitions were clearly observed at room temperature. For ZnO the two transitions are separated by the energy of ∼65 meV, which is attributed to the free exciton binding energy in ZnO. Due to magnesium incorporation, the CER resonances broaden and shift to blue. The energy separation between excitonic and band-to-band transitions increases up to ∼100 meV when the magnesium concentration reaches 22%. For larger magnesium concentrations, CER resonances are significantly broadened and the excitonic transition is no longer resolved in the CER spectrum.
The electron-phonon relaxation time in thin superconducting titanium nitride films
Authors: Kardakova A. , Finkel M. , Morozov D. , Kovalyuk V. , An P. , Dunscombe C. , Tarkhov M. , Mauskopf P. , Klapwijk T. M. , Goltsman G.
Published: December 2013

We report on the direct measurement of the electron-phonon relaxation time, τeph, in disordered TiN films. Measured values of τeph are from 5.5 ns to 88 ns in the 4.2 to 1.7 K temperature range and consistent with a T−3 temperature dependence. The electronic density of states at the Fermi level N0 is estimated from measured material parameters. The presented results confirm that thin TiN films are promising candidate-materials for ultrasensitive superconducting detectors.
Shift of the blocking temperature of Co nanoparticles by Cr capping
Authors: Ewerlin M. , Petracic O. , Demirbas D. , Agudo L. , Eggeler G. , Brüssing F. , Abrudan R. , Zabel H.
Published: December 2013

We have studied the effect of Cr capping on the magnetic properties of Co nanoparticles (NPs). The NPs have an average diameter of 2.2 nm. The blocking temperature TB of the bare Co particles is 13.2 K. By capping with a thin Cr layer up to a thickness of tCr = 0.52 nm, we first observe a decrease of TB up to tCr = 0.14 nm, followed by an increase of TB for larger thicknesses 0.14 nm ≤ tCr ≤ 0.52 nm. X-ray magnetic circular dichroism measurements at the resonant Co and Cr L3 edges confirm a magnetic polarization of Cr which is opposite to the magnetization of Co. The antiparallel alignment of Co and Cr spins at the Co/Cr interface can explain the decrease at low capping layer thickness. However, for larger Cr capping layer thicknesses, the Cr film bridges the Co NPs, mediating interparticle exchange coupling and enhancing dipolar coupling that leads to an increase of the blocking temperature.
Stochastic memristive nature in Co-doped CeO2 nanorod arrays
Authors: Younis Adnan , Chu Dewei , Li Sean
Published: December 2013

In this Letter, bipolar resistive switching characteristics of electrochemically deposited pure and Cobalt doped CeO2 nanorods architectures were reported. A conducting filament based model to address resistive switching process in these devices was proposed. Furthermore, the randomness in individual switching events and the prediction of switching probabilities were studied by imposing weak programming conditions. The present study offers insights into scrutinize the inherent stochastic nature in resistive switching characteristics within these devices rather than stressfully achieve high switching probabilities using excess voltage or time.
Wetting states on structured immiscible liquid coated surfaces
Authors: Jenner Elliot , D'Urso Brian
Published: December 2013

Water on structured hydrophobic surfaces can be supported in a Wenzel or Cassie state, depending on surface chemistry and structure geometry. The Cassie state is often desirable for superhydrophobic materials as it features high contact angles and low contact angle hysteresis due to an air layer which separates most of the liquid from contact with the solid. We present evidence that multiple wetting states for water can also exist on multiscale structured surfaces with a layer of an immiscible liquid coating the surface and that a Cassie-like state can be achieved which results in enhancement of the surface properties.
Transient streaming current measurements in nanochannels for molecular detection
Authors: Martins D. C. , Chu V. , Conde J. P.
Published: December 2013

Streaming currents were measured in silica slit-like nanochannels with integrated electrodes using a pulsed flow of deionized water. The analysis of the transient streaming current measurements in nanochannels shows that streaming currents are proportional to the surface charge density σ and that the effective reduction of nanochannel height by immobilized biomolecules needs to be taken into account. The σ of silica nanochannels was measured after performing sequential chemical surface modification steps. The nanochannel surface was first altered with positively charged polylysine and then with non-charged polyethylene glycol showing that nanochannels can sense the charge and size of surface-immobilized molecules.
Imaging regenerating bone tissue based on neural networks applied to micro-diffraction measurements
Authors: Campi G. , Pezzotti G. , Fratini M. , Ricci A. , Burghammer M. , Cancedda R. , Mastrogiacomo M. , Bukreeva I. , Cedola A.
Published: December 2013

We monitored bone regeneration in a tissue engineering approach. To visualize and understand the structural evolution, the samples have been measured by X-ray micro-diffraction. We find that bone tissue regeneration proceeds through a multi-step mechanism, each step providing a specific diffraction signal. The large amount of data have been classified according to their structure and associated to the process they came from combining Neural Networks algorithms with least square pattern analysis. In this way, we obtain spatial maps of the different components of the tissues visualizing the complex kinetic at the base of the bone regeneration.
Manipulating terahertz electromagnetic induced transparency through parallel plate waveguide cavities
Authors: Chen Lin , Xu Jiaming , Gao Chunmei , Zang Xiaofei , Cai Bin , Zhu Yiming
Published: December 2013

To mechanically manipulate of electromagnetic induced transparency (EIT) in terahertz asymmetric parallel-plate waveguide cavities, the influence of waveguide spacing on the transmission response has been studied experimentally. After setting the appropriate shifting length between two cavities, we found with mechanically increasing the waveguide spacing, the symmetric resonance shows degeneracy when its wavelength is smaller than the waveguide spacing. An on-to-off modulation for symmetric resonance appeared in EIT can be observed with destructive interference broken. This control mechanism of EIT will open a door to design the tunable EIT devices.
Doping mechanisms in graphene-MoS2 hybrids
Authors: Sachs B. , Britnell L. , Wehling T. O. , Eckmann A. , Jalil R. , Belle B. D. , Lichtenstein A. I. , Katsnelson M. I. , Novoselov K. S.
Published: December 2013

We present a joint theoretical and experimental investigation of charge doping and electronic potential landscapes in hybrid structures composed of graphene and semiconducting single layer molybdenum disulfide (MoS2). From first-principles simulations, we find electron doping of graphene due to the presence of rhenium impurities in MoS2. Furthermore, we show that MoS2 edges give rise to charge reordering and a potential shift in graphene, which can be controlled through external gate voltages. The interplay of edge and impurity effects allows the use of the graphene-MoS2 hybrid as a photodetector. Spatially resolved photocurrent signals can be used to resolve potential gradients and local doping levels in the sample.
Preparing a 21st century workforce: is it time to consider clinically based, competency-based training of health practitioners?
Authors: Nancarrow Susan A. , Moran Anna M. , Graham Iain
Published: December 2013

Health workforce training in the 21st century is still based largely on 20th century healthcare paradigms that emphasise professionalisation at the expense of patient-focussed care. This is illustrated by the paradox of increased training times for health workers that have corresponded with workforce shortages, the limited career options and pathways for paraprofessional workers, and inefficient clinical training models that detract from, rather than add to, service capacity. We propose instead that a 21st century health workforce training model should be: situated in the clinical setting and supported by outsourced university training (not the other way around); based on the achievement of specific milestones rather than being time-defined; and incorporate para-professional career pathways that allow trainees to ‘step-off’ with a useable qualification following the achievement of specific competencies. Such a model could be facilitated by existing technology and clinical training infrastructure, with enormous potential for economies of scale in the provision of formal training. The benefits of a clinically based, competency-based model include an increase in clinical service capacity, and clinical training resources become a resource for the delivery of healthcare, not just education. Existing training models are unsustainable, and are not preparing a workforce with the flexibility the 21st century demands.
Key influences on motivations for utility cycling (cycling for transport to and from places)
Authors: Heesch Kristiann C. , Sahlqvist Shannon
Published: December 2013

Issue addressed

Although increases in cycling in Brisbane are encouraging, bicycle mode share to work (the proportion of people travelling to work by bicycle) in the state of Queensland remains low. The aim of this qualitative study was to draw upon the lived experiences of Queensland cyclists to understand the main motivators for utility cycling (cycling as a means to get to and from places) and compare motivators between utility cyclists (those who cycle for utility as well as for recreation) and non‐utility cyclists (those who cycle only for recreation).

Methods

For an online survey, members of a bicycle group (831 utility cyclists and 931 non‐utility cyclists, aged 18–90 years) were asked to describe, unprompted, what would motivate them to engage in utility cycling (more often). Responses were coded into themes within four levels of an ecological model.

Results

Within an ecological model, built environment influences on motivation were grouped according to whether they related to appeal (safety), convenience (accessibility) or attractiveness (more amenities) and included adequate infrastructure for short trips, bikeway connectivity, end‐of‐trip facilities at public locations and easy and safe bicycle access to destinations outside of cities. A key social‐cultural influence related to improved interactions among different road users.

Conclusions

The built and social‐cultural environments need to be more supportive of utility cycling before even current utility and non‐utility cyclists will be motivated to engage (more often) in utility cycling.

So what?

Additional government strategies and more and better infrastructure that support utility cycling beyond commuter cycling may encourage a utility cycling culture.
Edible gardens in early childhood education settings in Aotearoa, New Zealand
Authors: Dawson A. , Richards R. , Collins C. , Reeder A. I. , Gray A.
Published: December 2013

Issue addressed

This paper aims to explore the presence and role of edible gardens in Aotearoa/New Zealand Early Childhood Education Services (ECES).

Methods

Participant ECES providers were identified from the Ministry of Education database of Early Childhood Education Services (March 2009). These include Education and Care and Casual Education and Care, Kindergarten, Home‐based Education and Care services, Playcentres, Te Kohanga Reo. A structured, self‐administered questionnaire was sent to the Principal or Head Teacher of the service

Results

Of the 211 ECES that responded (55% response rate), 71% had edible gardens, incorporating vegetables, berry fruit, tree fruit, edible flowers and nut trees. Garden activities were linked with teaching across all strands of the New Zealand early childhood curriculum. In addition, 34% provided guidance on using garden produce and 30% linked the garden with messages on fruit and vegetable consumption. Most gardens were established recently (past 2 years) and relied on financial and nonfinancial support from parents, teachers and community organisations. Barriers included a lack of funding, space, time and staff support.

Conclusions/Implications

Study findings suggest that gardens are already being used as a versatile teaching tool in many ECES settings. Most gardens are new, with a need to support the sustainability and workforce development among teachers and parents in order to be able to maintain these resources for future generations.

So what?

Given the inherent links between gardening and healthy food and exercise, there seem to be extensive opportunities for health promotion aligned with the edible garden movement.
Sitting time, physical activity and cervical intraepithelial neoplasia in Australian women: a preliminary investigation
Authors: Chih HuiJun , Lee Andy H. , Colville Linda , Xu Daniel , Binns Colin W.
Published: December 2013

Issue addressed

Physical activity affects the immune system, which in turn may modify the risk of cervical intraepithelial neoplasia (CIN). The effect of sitting on CIN is unknown. This study investigated the relationship between sitting time, physical activity and the risk of CIN.

Methods

Community‐dwelling adult women within metropolitan Perth, Western Australia, who had had a Papanicolaou (Pap) smear test at any of five clinics and medical centres, were approached by their general practitioners. In total, 348 women were recruited and interviewed for information on sitting time, physical activity level and lifetime physical activity exposure using the International Physical Activity Questionnaire (IPAQ) – short form. Associations of exposure variables with CIN risk were assessed by unconditional logistic regression analyses.

Results

The prevalence of abnormal Pap smear status indicating CIN was found to be 15.8%. Women with prolonged sitting duration (42 h per week) had significantly increased risk of CIN (adjusted OR 3.49, 95% CI 1.12–10.88) than women who sat less than 24.5 h per week. Although the effect of total physical activity level was non‐significant (P = 0.408), being always involved in physical activity during the entire life appeared to be inversely associated with the CIN risk (P = 0.036).

Conclusions

Prolonged sitting time was significantly associated with increased risk of abnormal Pap smear status indicating CIN.

So what?

This preliminary investigation highlights a new prospect for health‐promotion intervention to reduce the risk of CIN. Health practitioners should encourage women to reduce their sitting time and maintain physically active throughout their life course.
The potential for sown tropical perennial grass pastures to improve soil organic carbon in the North-West Slopes and Plains of New South Wales
Authors: Schwenke G. D. , McLeod M. K. , Murphy S. R. , Harden S. , Cowie A. L. , Lonergan V. E.
Published: December 2013

Sown tropical perennial grass pastures may be a means to restore soil organic carbon (C) lost by cropping with conventional tillage to the levels originally present in native grass pastures. To assess this, total organic carbon and related soil properties were measured under sown tropical pastures, conventionally cultivated cropping, and native pastures on 75 Chromosols and 70 Vertosols to 0.3 m depth in the New South Wales North-West Slopes and Plains region of Australia. The impact of several perennial pasture species on soil organic carbon was also assessed in a 6-year-old, sown pasture experiment on a previously cropped Chromosol.
Soil cores in 0.1-m segments to 0.3 m were analysed for total organic carbon, total nitrogen (N), pH, and phosphorus (Colwell-P). Mid-infrared scans were used to predict the particulate, humus, and resistant fractions of the total organic carbon. Bulk density was used to calculate stocks of C, N, and C fractions.
In Chromosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (23.1 Mg ha–1) than conventional tillage cropping (17.7 Mg ha–1), but still less than under native pastures (26.3 Mg ha–1). Similar land-use differences were seen for particulate and resistant organic C, and total N. The proportional differences between land uses were much greater for particulate organic C than other measures, and were also significant at 0.1–0.2 and 0.2–0.3 m. Subsurface bulk density (0.1–0.2 m) was lower under sown tropical pastures (1.42 Mg m–3) than conventionally tilled cropping (1.52 Mg m–3). For Vertosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (19.0 Mg ha–1) and native pastures (20.5 Mg ha–1) than conventional tillage cropping (14.0 Mg ha–1). Similar land-use effects were seen for the particulate and humus organic C fractions, and total N.
In the sown pasture species experiment, there was no significant difference in total N, total organic carbon, or any C fraction between soils under a native-grass species mixture, two improved tropical grass species, or a perennial pasture legume. Regular monitoring is required to better discern whether gradual changes are being masked by spatial and temporal variation.
The survey results support previous research on Vertosols within the New South Wales North-West Slopes and Plains that show sown tropical grass pastures can improve total organic carbon. Improvements in total organic carbon on Chromosols have not previously been documented, so further targeted soil monitoring and experimentation is warranted for the region.
Structure of a eukaryotic thiaminase I
Authors: Kreinbring Cheryl A. , Remillard Stephen P. , Hubbard Paul , Brodkin Heather R. , Leeper Finian J. , Hawksley Dan , Lai Elaine Y. , Fulton Chandler , Petsko Gregory A. , Ringe Dagmar
Published: December 2013

Significance

Thiaminases, enzymes that cleave vitamin B1 into its pyrimidine and thiazole ring moieties, are sporadically distributed among prokaryotes and eukaryotes. Thiaminase I enzymes accomplish this reaction through substitution of the thiazole ring with a nitrogenous base or sulfhydryl compound. A thiaminase I of the single-celled amoeboflagellate
Naegleria gruberi
is the first eukaryotic thiaminase I to have been examined structurally. The crystal structures in both
apo
form and bound to 3-deazathiamin, a noncleavable thiamin analog and inhibitor of the enzyme, define the mode of thiamin binding to this class of thiaminases and indicate the residues important for catalysis. Comparison with thiaminase II argues for convergent evolution between these two enzymes.
Transient kinetics measured with force steps discriminate between double-stranded DNA elongation and melting and define the reaction energetics
Authors: Bongini Lorenzo , Melli Luca , Lombardi Vincenzo , Bianco Pasquale
Published: December 2013

Under a tension of ∼65 pN, double-stranded DNA undergoes an overstretching transition from its basic (B-form) conformation to a 1.7 times longer conformation whose nature is only recently starting to be understood. Here we provide a structural and thermodynamic characterization of the transition by recording the length transient following force steps imposed on the λ-phage DNA with different melting degrees and temperatures (10–25°C). The shortening transient following a 20–35 pN force drop from the overstretching force shows a sequence of fast shortenings of double-stranded extended (S-form) segments and pauses owing to reannealing of melted segments. The lengthening transients following a 2–35 pN stretch to the overstretching force show the kinetics of a two-state reaction and indicate that the whole 70% extension is a B-S transition that precedes and is independent of melting. The temperature dependence of the lengthening transient shows that the entropic contribution to the B-S transition is one-third of the entropy change of thermal melting, reinforcing the evidence for a double-stranded S-form that maintains a significant fraction of the interstrand bonds. The cooperativity of the unitary elongation (22 bp) is independent of temperature, suggesting that structural factors, such as the nucleic acid sequence, control the transition.
Halomonas huangheensis sp. nov., a moderately halophilic bacterium isolated from a saline–alkali soil
Authors: Miao Chaohua , Jia Fangfang , Wan Yusong , Zhang Wei , Lin Min , Jin Wujun
Published: December 2013

A novel, Gram-stain-negative, aerobic, rod-shaped, non-motile and moderately halophilic bacterium, designated strain BJGMM-B45T, was isolated from a saline–alkali soil collected from Shandong Province, China. Growth of strain BJGMM-B45T occurred at 10–45 °C (optimum, 30 °C) and pH 5.0–12.0 (optimum, pH 7.0) on Luria–Bertani agar medium with 1–20 % (w/v) NaCl (optimum, 7–10 %). The predominant respiratory quinone was Q-9. The major cellular fatty acids (>5 %) were C18 : 1ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3, C12 : 0 3-OH and C12 : 0. The genomic DNA G+C content was 57.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BJGMM-B45T belonged to the genus

Halomonas

in the class

Gammaproteobacteria

. The closest relatives were

Halomonas cupida

DSM 4740T (98.2 % 16S rRNA gene sequence similarity) and

Halomonas denitrificans

M29T (97.8 %). Levels of DNA–DNA relatedness between strain BJGMM-B45T and

Halomonas cupida

CGMCC 1.2312T and

Halomonas denitrificans

DSM 18045T were 57.0 and 58.9 %, respectively. On the basis of phenotypic, chemotaxonomic and phylogenetic features, strain BJGMM-B45T is considered to represent a novel species of the genus

Halomonas

, for which the name Halomonas huangheensis sp. nov. is proposed. The type strain is BJGMM-B45T ( = ACCC 05850T = KCTC 32409T).
Flavobacterium lacus sp. nov., isolated from a high-altitude lake, and emended description of Flavobacterium filum
Authors: Li Aihua , Liu Hongcan , Sun Bingda , Zhou Yuguang , Xin Yuhua
Published: December 2013

Two Gram-stain-negative, non-motile, rod-shaped bacterial strains, designated NP180T and NR80, were isolated from water of Nam Co Lake, located in Tibet, China. Growth of strains NP180T and NR80 occurred at 4–25 °C and at pH 6.5–10.0 (optima, 15–20 °C and pH 7.5–8.5). The 16S rRNA gene sequence similarity to the phylogenetically closest related strains,

Flavobacterium filum

EMB 34T,

F. ponti

GSW-R14T and

F. gelidilacus

LMG 21477T, was 95.1, 94.8 and 94.6 %, respectively. The predominant fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 9 (comprising iso-C17 : 1ω9c and/or 10-methyl C16 : 0). The major menaquinone of the two strains was menaquinone 6 (MK-6). Phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid were the major polar lipids in both strains. The G+C contents of the genomic DNA were 34.9 and 35.1 mol%, respectively, for strains NP180T and NR80. DNA–DNA relatedness between strains NP180T and NR80 was 99 %, indicating that they belong to the same species. According to phylogenetic inference and phenotypic characteristics, a novel species, Flavobacterium lacus sp. nov., is proposed. The type strain is NP180T ( = CGMCC 1.12504T = NBRC 109715T). An emended description of

Flavobacterium filum

is also provided.
Salinimicrobium sediminis sp. nov., isolated from a deep-sea sediment
Authors: Subhash Y. , Sasikala Ch. , Ramana Ch. V.
Published: December 2013

Strain JC207T was isolated from a deep (265 m) sea sediment, and appeared as dark yellow colonies on agar plates with cells staining Gram-negative. Catalase, oxidase and caseinase were positive, while chitinase, gelatinase and amylase were negative. Major (>5 %) fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C17 : 1ω9c, iso-C16 : 0, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH, iso-C14 : 0 and iso-C15 : 1G. Strain JC207T contained phosphatidylethanolamine as the major polar lipid, with minor amounts of five unidentified lipids. A bacterial hopane derivative, diplopterol and adenosylhopane were the major hopanoids. Genomic DNA G+C content was 47.5 mol%. 16S rRNA gene sequence comparisons indicated that strain JC207T represented a member of the genus

Salinimicrobium

within the family

Flavobacteriaceae

of the phylum

Bacteroidetes

. Strain JC207T had sequence similarity with

Salinimicrobium terrae

YIM-C338T (98 %),

Salinimicrobium xinjiangense

BH206T (97.6 %) and other members of the genus

Salinimicrobium

(<96.8 %). However, strain JC207T showed an average of 23.6±4 and 37±4 relatedness (based on DNA–DNA hybridization) with

Salinimicrobium terrae

CGMCC 1.6308T ( = YIM-C338T) and

Salinimicrobium xinjiangense

KCTC 12883T ( = BH206T), respectively. Morphological, physiological and genotypic differences from the previously described taxa support the classification of strain JC207T as a representative of a novel species in the genus

Salinimicrobium

, for which the name Salinimicrobium sediminis sp. nov. is proposed. The type strain is JC207T ( = KCTC 32444T = CGMCC 1.12641T).
The Potato Tuber Mitochondrial Proteome
Authors: Salvato Fernanda , Havelund Jesper F. , Chen Mingjie , Rao R. Shyama Prasad , Rogowska-Wrzesinska Adelina , Jensen Ole N. , Gang David R. , Thelen Jay J. , Møller Ian Max
Published: December 2013

Mitochondria are called the powerhouses of the cell. To better understand the role of mitochondria in maintaining and regulating metabolism in storage tissues, highly purified mitochondria were isolated from dormant potato tubers (Solanum tuberosum ‘Folva’) and their proteome investigated. Proteins were resolved by one-dimensional gel electrophoresis, and tryptic peptides were extracted from gel slices and analyzed by liquid chromatography-tandem mass spectrometry using an Orbitrap XL. Using four different search programs, a total of 1,060 nonredundant proteins were identified in a quantitative manner using normalized spectral counts including as many as 5-fold more “extreme” proteins (low mass, high isoelectric point, hydrophobic) than previous mitochondrial proteome studies. We estimate that this compendium of proteins represents a high coverage of the potato tuber mitochondrial proteome (possibly as high as 85%). The dynamic range of protein expression spanned 1,800-fold and included nearly all components of the electron transport chain, tricarboxylic acid cycle, and protein import apparatus. Additionally, we identified 71 pentatricopeptide repeat proteins, 29 membrane carriers/transporters, a number of new proteins involved in coenzyme biosynthesis and iron metabolism, the pyruvate dehydrogenase kinase, and a type 2C protein phosphatase that may catalyze the dephosphorylation of the pyruvate dehydrogenase complex. Systematic analysis of prominent posttranslational modifications revealed that more than 50% of the identified proteins harbor at least one modification. The most prominently observed class of posttranslational modifications was oxidative modifications. This study reveals approximately 500 new or previously unconfirmed plant mitochondrial proteins and outlines a facile strategy for unbiased, near-comprehensive identification of mitochondrial proteins and their modified forms.
Are not-for-profits learning from for-profit-organizations? A look into governance
Authors: M. Viader Ana , I. Espina Maritza
Published: December 2013

Purpose

–This paper aims to focus on governance theories and practice variables in Not-For-Profit Service Organizations. The research answers two questions: what the prevalent governance practices of Not-for-Profit Service Organizations (NPSO) are, and whether there is a crossover among NPSO governance practices and For-Profit-Organization theories in the literature.

Design/methodology/approach

–A questionnaire to the 285 organizations within the defined parameters obtained a 18 percent response. Data were collected regarding the boards' predominant roles in the organizations' governance activities, the top executives' predominant roles in the organizations' operations and their interrelationship with the boards, and the boards' most common meeting agenda topics.

Findings

–The findings prove that governance models in NPSO are mostly driven by Agency Theory (52 percent of the sample). Stewardship and Resource Dependence Theories also contribute to existing governance models (28 percent), while some of the organizations have developed Hybrid Models (20 percent) drawing from the various theories.

Research limitations/implications

–The limited number of organizations participating in the research does not allow a generalization. However the diversity of organization types and sizes within the scope do provide a panoramic view of the not-for-profit service sector.

Practical implications

–Having proved that there is a crossover of governance practices among For-Profit and Not-for Profit Organizations, this research opens the door to the evaluation of many other existing or potential crossovers in governance and other management elements.

Originality/value

–This research is novel in its approach to look for similarities rather than differences between For-Profit and Not-for-Profit Organizations. The approach allows both sectors to learn from each other and seek for fresh improvement alternatives.
From knife to paper: an audit of surgical communication
Authors: Ip Brian , Beverly Brenda Lim Chern , Chauhan Satvinder , Black Douglas
Published: December 2013

Purpose

– The paper aims to assess the quality (content and legibility) of handwritten operation notes and the reader's interpretation of legibility by clinical seniority.

Design/methodology/approach

– Consecutive elective and emergency general surgical operations over a six-week period from September 2011 at one hospital were retrospectively collected. Non-retrieval of operation notes, typed notes and endoscopies were excluded. The content of each operation note was assessed against a 26-item checklist. Legibility was assessed by 4 readers (2 Foundation Doctors and 2 Registrars in General Surgery) using an original objective scoring system.

Findings

– A total of 404 operations were identified; 45 were excluded following review of operation notes. Operation notes were derived from 12 consultants and 11 registrars. Analysis of the content score suggested that time of procedure (1 per cent), ASA grade (1 per cent) and blood loss (5 per cent) were poorly reported. Clinical indication and post-operative instructions were documented in only 52 per cent and 66 per cent of operation notes respectively. Registrar notes had a higher content score compared with consultant notes (15.8 vs 13.5, p<0.001). Legibility scores were reported to be higher for Registrar readers, compared with Foundation Doctor readers (OR 1.95, 95 per cent CI 1.75-2.18, p<0.001). Registrar-written notes had higher legibility scores compared with consultants (OR 19.0, 95 per cent CI 11.6-31.2, p<0.001).

Research limitations/implications

– The quality of handwritten notes varies. Registrar-written notes are more content-rich and legible.

Practical implications

– Clinical seniority and specialty training may improve the interpretation of handwritten operation notes. This study adds to growing evidence supporting the widespread adoption of a computerized immediate operation note.

Originality/value

– An objective scoring system to assess legibility of operation notes written as freehand was used. Also, legibility according to the reader's seniority in clinical training was evaluated.
Achieving standards for unscheduled surgical care
Authors: McArdle Kirsten , Leung Edmund , Cruickshank Neil , Laloe Veronique
Published: December 2013

Purpose

– The Royal College of Surgeons published Standards for Unscheduled Surgical Care in response to variable clinical outcomes for emergency surgery. The purpose of this study is to assess for feasibility of a district hospital providing care in accordance to the recommendations.

Design/methodology/approach

– A total of 100 consecutive patient unscheduled episodes of care were prospectively included. Information regarding demographics, timeliness of investigations, operations, consultant input and clinical outcomes was collated. All patients were risk-adjusted for mortality. The data were compared to the guidelines.

Findings

– A total of 91 patients were included; 80 patients underwent surgery. There were 18 deaths (22.5 per cent), eight (10 per cent) post-operative within 30 days. There was no statistical difference between deaths and day of admission or surgery. There were 39 critically-ill patients, none were reviewed by a consultant within the recommended 30 minutes. Of the critically-ill patients, 23 underwent CT scanning, none within the recommended 30 minutes. All patients were operated within the recommended timeframe by urgency grading. For those predicted mortality rate >5 per cent, a consultant was present in theatre for 97 per cent of cases. All patients had a consultant review within 24 hours of admission.

Originality/value

– To the authors' knowledge this is the first evaluation of the practical difficulties in achieving consultant delivered care in surgery in a district general hospital. These results are interesting to clinicians and service planners involved in developing emergency services. Adhering to these guidelines would require significant re-allocation of resources in most hospitals and may require centralisation of services.
A run time combustion zoning technique towards the EDC approach in large-scale CFD simulations
Authors: S. Vaid Hitesh , Devesh Singh Kanwar , H. Lou Helen , Chen Daniel , Richmond Peyton
Published: December 2013

Purpose

– This paper aims to present a novel run time combustion zoning (RTCZ) technique based on the working principle of eddy dissipation concept (EDC) for combustion modeling. This technique selectively chooses cells in which the full reaction mechanism needs to be solved. The selection criterion is based on the concept of differentiating between combustion and the non-combustion zone. With this approach, considerable reduction in computational load and stability of the solution was observed and even the number of iterations required to achieve a stable solution was significantly reduced.

Design/methodology/approach

– Computational fluid dynamics (CFD) simulations of real life combustion problems such as industrial scale flares, fuel fired furnaces and IC engines are difficult due to the strong interactions of chemistry with turbulence as well as the wide range distribution of time and length scales. In addition, comprehensive chemical mechanisms for hydrocarbon combustion may include hundreds of species and thousands of reactions that are known in detail for only a limited number of fuels. Even with the most advanced computers, accurate simulation of these problems is not easy. Hence, the modeler needs to have strategies to either simplify the chemistry or to improve the computational efficiency.

Findings

– The EDC turbulence model has been widely used for treating the interaction between turbulence and the chemistry in combustion problems. In an EDC model, combustion is assumed to occur in a constant pressure reactor, with initial conditions taken as the concentration of the current species and temperature in the cell. With these assumptions, EDC solves the full or simplified reaction mechanism in all the grid cells at all iterations.

Originality/value

– This paper presents a novel RTCZ technique for improving the computational efficiency, when the EDC model is used in CFD modeling. Considerable reduction in computational time and stability of the solution can be achieved. It was also observed that the number of iterations required to achieve a converged solution was significantly reduced.
Free convection in a tilted triangle porous cavity filled with Cu-water nanofluid with flush mounted heater on the wall
Authors: Sun Qiang , Pop Ioan
Published: December 2013

Purpose

– Steady-state free convection heat transfer and fluid flow of Cu-water nanofluid is investigated within a porous tilted right-angle triangular enclosure. The paper aims to discuss these issues.

Design/methodology/approach

– The flush mounted heater with finite size is placed on one right-angle wall. The temperature of the inclined wall is lower than the heater, and the rest of walls are adiabatic. The governing equations are obtained based on the Darcy's law, and the nanofluid model adopted is that by Tiwari and Das. The transformed dimensionless governing equations were solved numerically by finite difference method, and the solution for algebraic equations was obtained through successive under relaxation method.

Findings

– Investigations were made as the tilted angle of the cavity varies within under different values of Rayleigh number for a porous medium with and solid volume fraction parameter of Cu-water nanofluid with. It is found that the maximum value of the average Nusselt number is achieved with the highest Rayleigh number when the tilted angle of the cavity is 150°, while the minimum value of the average Nusselt number is obtained with the lowest Rayleigh number when the tilted angle of the cavity locates at 240°. As soon as the flow convection in the cavity is not significant, increasing can improve the value of, but opposite effects appear when flow convection becomes stronger.

Originality/value

– The present results are new and original for the heat transfer and fluid flow in a porous tilted triangle enclosure filled by Cu-water nanofluid. The results would benefit scientists and engineers to become familiar with the flow behaviour of such nanofluids, and the way to predict the properties of this flow for possibility of using nanofluids in advanced nuclear systems, in industrial sectors including transportation, power generation, chemical sectors, ventilation, air-conditioning, etc.