bluuebunny/crossref_metadata_2025 huggingface dataset:
The L-Z complexity of exercise-induced muscle fatigue based on acoustic myographye
Authors: Yijian Min , Xinyuan Liu , Tingting Wang
Published: January 2014

The mechanism of exercise fatigue was investigated during exercise using L-Z complexity of non-linear analysis. Muscle fatigue was induced in the sitting position by lifting the heel under a load. An acoustic myogram of the gastrocnemius was obtained until exhaustion. The different modes of the speed responses were calculated using the L-Z complexity method, which analyzes muscle fibers participation, while the exercise is in progress. The L-Z complexity decreased incrementally with decreases in muscle strength, reaching a minimum value when the muscle was exhausted. Our data indicate that the L-Z complexity method is easy to use and effective at revealing the dynamic characteristics and variations of exercise fatigue. This method could be used to monitor sports training.
On core compressibility of sandwich composite panels subjected to intense underwater shock loads
Authors: Ghoshal Ritwik , Mitra Nilanjan
Published: January 2014

Novel analytical models have been proposed in this study which extends current available fluid-structure interaction (FSI) theories for explosion induced shock loading on monolithic and laminated composite plates to sandwich composite panels, featuring core compression. The proposed models have been asymptotically validated against other FSI existing theories in low pressure range. A qualitative comparative analysis of the proposed models has been made with other existing FSI theories from the viewpoint of energy conservation. Core compression as predicted by the proposed models can be utilized for more economical, robust design of blast resistant sandwich composite structures.
Effect of nano-filler on the performance of multiwalled carbon nanotubes based electrochemical double layer capacitors
Authors: Jain Amrita , Tripathi S. K.
Published: January 2014

This article presents the main features of electrochemical double layer capacitor (EDLC), made up of multiwalled carbon nanotubes as electrode materials and electrolyte based on nano silica dispersed in poly(vinylidene fluoride-co-hexafluoropropylene)-based magnesium ion conducting nano composite gel polymer electrolyte. The capacitance value was stable up to 5000 voltammetric cycles and even more. The performance characteristics of EDLC have been tested using cyclic-voltammetry, impedance spectroscopy, and charge-discharge techniques. Analysis shows that the nano-filler based EDLC has relatively larger capacitance value as compared to filler-free based electrolyte. The maximum capacitance of 92 mF cm−2, equivalent to single electrode specific capacitance of 92 F g−1 was achieved. It corresponds to energy-density of 10.5 W h kg−1 and power-density of 3.25 kW kg−1.
Spatial recurrence analysis: A sensitive and fast detection tool in digital mammography
Authors: Prado T. L. , Galuzio P. P. , Lopes S. R. , Viana R. L.
Published: January 2014

Efficient diagnostics of breast cancer requires fast digital mammographic image processing. Many breast lesions, both benign and malignant, are barely visible to the untrained eye and requires accurate and reliable methods of image processing. We propose a new method of digital mammographic image analysis that meets both needs. It uses the concept of spatial recurrence as the basis of a spatial recurrence quantification analysis, which is the spatial extension of the well-known time recurrence analysis. The recurrence-based quantifiers are able to evidence breast lesions in a way as good as the best standard image processing methods available, but with a better control over the spurious fragments in the image.
Gate-tunable gigantic lattice deformation in VO2
Authors: Okuyama D. , Nakano M. , Takeshita S. , Ohsumi H. , Tardif S. , Shibuya K. , Hatano T. , Yumoto H. , Koyama T. , Ohashi H. , Takata M. , Kawasaki M. , Arima T. , Tokura Y. , Iwasa Y.
Published: January 2014

We examined the impact of electric field on crystal lattice of vanadium dioxide (VO2) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO2 decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature.
A high-Q resonator using biocompatible materials at microwave frequencies
Authors: Lee Hee-Jo , Hyun Kyung-A , Jung Hyo-Il
Published: January 2014

In this paper, we present a high quality (Q)-factor resonator utilizing biocompatible materials, thin glass and polydimethylsiloxane, at microwave regime. The proposed resonator is completely matched with a 50-ohm characteristic impedance via the materials. From the resulting matching, we find that it shows a half-wavelength resonance having an extremely high quality-value. Actually, the loaded quality-factor is about 1 670 at the resonant frequency of 12.52 GHz. From this work, we suggest that our device can be a good candidate as a simple, cost-efficient, and non-contact sensor device based on frequency and quality-factor variation.
From kesterite to stannite photovoltaics: Stability and band gaps of the Cu2(Zn,Fe)SnS4 alloy
Authors: Shibuya Taizo , Goto Yosuke , Kamihara Yoichi , Matoba Masanori , Yasuoka Kenji , Burton Lee A. , Walsh Aron
Published: January 2014

Kesterite semiconductors, particularly Cu2ZnSnS4 (CZTS), have attracted attention for thin-film solar cells. We investigate the incorporation of Fe into CZTS to form the Cu2(Zn,Fe)SnS4 solid-solution for tuning the lattice spacing and band gap. First-principles calculations confirm a phase transition from kesterite (Zn-rich) to stannite (Fe-rich) at Fe/Zn ∼ 0.4. The exothermic enthalpy of mixing is consistent with the high solubility of Fe in the lattice. There is a linear band-gap bowing for each phase, which results in a blue-shift of photo-absorption for Fe-rich alloys due to the confinement of the conduction states. We propose compositions optimal for Si tandem cells.
Heteroepitaxy of InP on Si(001) by selective-area metal organic vapor-phase epitaxy in sub-50 nm width trenches: The role of the nucleation layer and the recess engineering
Authors: Merckling C. , Waldron N. , Jiang S. , Guo W. , Collaert N. , Caymax M. , Vancoille E. , Barla K. , Thean A. , Heyns M. , Vandervorst W.
Published: January 2014

This study relates to the heteroepitaxy of InP on patterned Si substrates using the defect trapping technique. We carefully investigated the growth mechanism in shallow trench isolation trenches to optimize the nucleation layer. By comparing different recess engineering options: rounded-Ge versus V-grooved, we could show a strong enhancement of the crystalline quality and growth uniformity of the InP semiconductor. The demonstration of III-V heteroepitaxy at scaled dimensions opens the possibility for new applications integrated on Silicon.
Effect of rapid thermal processing on copper precipitation in p/p+ silicon epitaxial wafers with heavily boron-doped substrates
Authors: Xu Jin , Ji Chuan , Zhang Guangchao
Published: January 2014

The effect of rapid thermal processing (RTP) on the formation of copper precipitation in p/p+ silicon (Si) epitaxial wafers was systematically investigated by defect etching and optical microscopy. After RTP preannealing at high temperature (1250 °C/60 s, with cooling rate 30 K/s) followed by the 750 °C/8 h + 1050 °C/16 h low-high (L-H) two-step annealing, it was revealed that the bulk microdefects were found only inside the p+ substrate, manifesting no defects generated in the epitaxial layer. However, it was found that the width of denude zone (DZ) in samples only subjected to L-H two-step annealing was narrower than that of epitaxial layer, which meant that oxygen precipitation was formed in epitaxial layer. It can be concluded that RTP was beneficial to the formation of DZ. Additionally, it was found that the width of DZ has a sharp dependence on the introducing temperature of copper contamination, that is, the corresponding equilibrium concentration of interstitial copper in the Si influence the thermodynamics and kinetics process of the formation of copper precipitation significantly.
Phase transitional behavior and electric field-induced large strain in alkali niobate-modified Bi0.5(Na0.80K0.20)0.5TiO3 lead-free piezoceramics
Authors: Hao Jigong , Shen Bo , Zhai Jiwei , Chen Haydn
Published: January 2014

The effect of (KyNa1-y)NbO3 (KyNN) addition on the ferroelectric stability and consequent changes in the electrical properties of lead-free Bi0.5(Na0.80K0.20)0.5TiO3 (BNKT20) piezoceramics were systematically studied. Results showed that the KyNN substitution into BNKT20 induces a phase transition from coexistence of ferroelectric tetragonal and rhombohedral to a relaxor pseudocubic with a significant disruption of the long-range ferroelectric order, and correspondingly adjusts the ferroelectric-relaxor transition point TF-R to room temperature. Accordingly, a large electric-field-induced strain of 0.33%–0.46% (Smax/Emax = 413–575 pm/V), which is derived from a reversible field-induced ergodic relaxor to ferroelectric phase transformation, was obtained in KyNN-modified compositions near the phase boundary. Moreover, a relationship between the position of the ferroelectric-relaxor phase boundary and the tolerance factor t of the end member KyNN was found in BNKT20–xKyNN system, which is expected to provide a guideline for searching the new ferroelectric-relaxor phase boundary where the strain response is consistently derivable in (Bi0.5Na0.5)TiO3-based materials.
Peak load sharing based on blade pitch control of wind turbine in the presence of utility supply
Authors: Mansoor Ashraf Muhammad , Nadeem Malik Tahir , Iqbal Mehroze
Published: January 2014

The alternate energy resources are replacing conventional energy sources for electricity production because of tremendously increasing environmental pollution and cost of fossil fuels. Wind power is one of the potential alternate energy resources and is being deployed actively. Wind power generation system comprises of wind turbine and electrical generator as essential parts interconnected through gear box. The conventional wind turbines are designed with adjustable blade pitch to regulate shaft speed of turbine or to withstand against heavy wind blows. In this paper, a technique for peak load sharing in the presence of utility supply using Pitch Frequency Control (PFC) is proposed for wind turbines. This technique has been simulated in MATLAB environment using Simulink. The simulation results show that PFC finds its applications with wind energy system having low speed axial flux synchronous generator as well as with the wind energy system with small gear ratio. This particular proposed PFC based control presents a cost effective technique for efficient peak load sharing and wind energy system free of power electronic converters.
Exchange bias and magnetic properties induced by intrinsic structural distortion in CaMn3O6 nanoribbons
Authors: Yu J. Y. , Huang K. , Wu H. Y. , Feng Y. , Wang L. , Tang Z. , Zhang L.
Published: January 2014

Single-crystalline CaMn3O6 nanoribbons have been synthesized by a molten-salt method. To explore the origin of the magnetism of nanosized antiferromagnetic (AFM) manganites, a comparative study has been conducted for CaMn3O6 (CMO-1) and post-growth vacuum annealed (CMO-2) nanoribbons. A lattice expansion resulting from oxygen release during vacuum annealing is observed. Correspondingly, AFM ordering in CMO-2 is further suppressed, and ferromagnetism and spin-glass (SG)-like behavior are significantly enhanced, which are presumed attributable to the intrinsic structural distortions induced by oxygen vacancies. In this case, side and surface effects are not decisive factors. In addition, this study provided observations of the exchange bias effect in manganite nanoribbons with an AFM-SG-like-ferromagnetic (FM) structure, as compared with the typical AFM-core-FM-shell.
Microfluidic electrical sorting of particles based on shape in a spiral microchannel
Authors: DuBose John , Lu Xinyu , Patel Saurin , Qian Shizhi , Woo Joo Sang , Xuan Xiangchun
Published: January 2014

Shape is an intrinsic marker of cell cycle, an important factor for identifying a bioparticle, and also a useful indicator of cell state for disease diagnostics. Therefore, shape can be a specific marker in label-free particle and cell separation for various chemical and biological applications. We demonstrate in this work a continuous-flow electrical sorting of spherical and peanut-shaped particles of similar volumes in an asymmetric double-spiral microchannel. It exploits curvature-induced dielectrophoresis to focus particles to a tight stream in the first spiral without any sheath flow and subsequently displace them to shape-dependent flow paths in the second spiral without any external force. We also develop a numerical model to simulate and understand this shape-based particle sorting in spiral microchannels. The predicted particle trajectories agree qualitatively with the experimental observation.
Structural and magnetic phase transitions in Bi1−xNdxFe1−xMnxO3 multiferroics
Authors: Khomchenko V. A. , Pereira L. C. J. , Paixão J. A.
Published: January 2014

Crystal structure, local ferroelectric and magnetic properties of the Bi1−xNdxFe1−xMnxO3 (0.05 ≤ x ≤ 0.25) ferromanganites have been studied at room temperature to reveal effect of the simultaneous Ln/Mn substitution on the multiferroic behavior of the BiFeO3 perovskite. The substitution tends to suppress polar displacements in initial rhombohedral phase to give rise to an intermediate PbZrO3-like antiferroelectric ionic arrangement at x = 0.11. Further increase of the Nd/Mn concentration stabilizes nonpolar structure specific to NdMnO3. Magnetic state of the Bi1−xNdxFe1−xMnxO3 compounds has been found to be structurally driven. The ferroelectric compounds demonstrate a dominant antiferromagnetic behavior. Magnetic field is able to modify the antiferromagnetic ordering to stabilize a weak ferromagnetic state. A threshold field inducing the metamagnetic transformation decreases with increasing the substituent's content. However, a critical Nd/Mn concentration that would yield weak ferromagnetism at H = 0 exceeds the upper limit of the compositional range of the ferroelectric phase existence, so the purely weak ferromagnetic state is realized in nonpolar solid solutions only.
On the dependence of the efficiency of a 240 GHz high-power gyrotron on the displacement of the electron beam and on the azimuthal index
Authors: Dumbrajs O. , Avramidis K. A. , Franck J. , Jelonnek J.
Published: January 2014

Two issues in the cavity design for a Megawatt-class, 240 GHz gyrotron are addressed. Those are first, the effect of a misaligned electron beam on the gyrotron efficiency and second, a possible azimuthal instability of the gyrotron. The aforementioned effects are important for any gyrotron operation, but could be more critical in the operation of Megawatt-class gyrotrons at frequencies above 200 GHz, which will be the anticipated requirement of DEMO. The target is to provide some basic trends to be considered during the refinement and optimization of the design. Self-consistent calculations are the base for simulations wherever possible. However, in cases for which self-consistent models were not available, fixed-field results are presented. In those cases, the conservative nature of the results should be kept in mind.
Role of electron-electron scattering on spin transport in single layer graphene
Authors: Ghosh Bahniman , Katiyar Saurabh , Salimath Akshaykumar
Published: January 2014

In this work, the effect of electron-electron scattering on spin transport in single layer graphene is studied using semi-classical Monte Carlo simulation. The D’yakonov-P’erel mechanism is considered for spin relaxation. It is found that electron-electron scattering causes spin relaxation length to decrease by 35% at 300 K. The reason for this decrease in spin relaxation length is that the ensemble spin is modified upon an e-e collision and also e-e scattering rate is greater than phonon scattering rate at room temperature, which causes change in spin relaxation profile due to electron-electron scattering.
Collision and diffusion in microwave breakdown of nitrogen gas in and around microgaps
Authors: Campbell J. D. , Bowman A. , Lenters G. T. , Remillard S. K.
Published: January 2014

The microwave induced breakdown of N2 gas in microgaps was modeled using the collision frequency between electrons and neutral molecules and the effective electric field concept. Low pressure breakdown at the threshold electric field occurs outside the gap, but at high pressures it is found to occur inside the microgap with a large threshold breakdown electric field corresponding to a very large electron oscillation amplitude. Three distinct pressure regimes are apparent in the microgap breakdown: a low pressure multipactor branch, a mid-pressure Paschen branch, both of which occur in the space outside the microgap, and a high pressure diffusion-drift branch, which occurs inside the microgap. The Paschen and diffusion-drift branches are divided by a sharp transition and each separately fits the collision frequency model. There is evidence that considerable electron loss to the microgap faces accompanies the diffusion-drift branch in microgaps.
Cyberspace: Connected or Segregated? Examining Virtual Segregation among Hong Kong Internet Users
Authors: Li Fei , Wang Donggen
Published: January 2014

In this paper we discuss how cyberspace has been interwoven in the geographies of social stratification and segregation nowadays. It conceptualizes ‘virtual segregation’ as an extension of the ‘digital divide’ and sociospatial segregation in urban spaces. A case study was conducted in Hong Kong in 2010, when 770 Internet users were surveyed. A comparison of their patterns of Internet use shows that these individuals, all of whom possess devices and Internet access, have varied levels of connectivity in cyberspace. A typology of Internet users was then derived from the perspective of virtual segregation. The findings suggest that people may be stratified and segregated in cyberspace in similar ways to the physical world, and that segregation studies should pay more attention to virtual segregation.
Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 1. Rationale, systems design and management
Authors: Chapman D. F. , Hill J. , Tharmaraj J. , Beca D. , Kenny S. N. , Jacobs J. L.
Published: January 2014

The profitability of dairy businesses in southern Australia is closely related to the amount of feed consumed from perennial ryegrass-dominant pasture. Historically, the dairy industry has relied on improvements in pasture productivity and utilisation to support profitable increases in stocking rate and milk production per hectare. However, doubts surround the extent to which the industry can continue to rely on perennial ryegrass technology to provide the necessary productivity improvements required into the future. This paper describes the design and management of a dairy systems experiment at Terang in south-west Victoria (780-mm average annual rainfall) conducted over four lactations (June 2005–March 2009) to compare the production and profitability of two forage base options for non-irrigated dairy farms. These options were represented by two self-contained farmlets each milking 36 mixed-age, autumn-calving Holstein-Friesian cows at peak: (1) well managed perennial ryegrass pasture (‘Ryegrass Max’, or ‘RM’); and (2) perennial ryegrass plus complementary forages (‘CF’) including 15% of farmlet area under double cropping with annual species (winter cereal grown for silage followed by summer brassica for grazing on the same land) and an average of 25% of farmlet area in perennial pasture based on tall fescue for improved late spring–early summer feed supply. The design of these systems was informed by farming systems models (DairyMod, UDDER and Redsky), which were used to estimate the effects of introducing different forage options on farm profitability. The design of the CF system was selected based on modelled profitability increases assuming that all forage components could be managed to optimise forage production and be effectively integrated to optimise milk production per cow. Using the historical ‘average’ pasture growth curve for the Terang district and a mean milk price of $3.71 per kg milk solids, the models estimated that the return on assets of the RM and CF systems would be 9.4 and 15.0%, respectively. The objectives of the experiment described here were to test whether or not such differences in profitability could be achieved in practice, and to determine the risks associated with including complementary forages on a substantial proportion of the effective farm area. Key results of the experiment are presented in subsequent papers.
Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 2. Forage harvested
Authors: Tharmaraj J. , Chapman D. F. , Hill J. , Jacobs J. L. , Cullen B. R.
Published: January 2014

A dairy farmlet experiment was conducted at Terang in south-west Victoria, Australia, over 4 years to test the hypothesis that a 30% increase in forage harvested per ha could be achieved in a production system that incorporated a range of Complementary Forages with perennial ryegrass (CF) compared with a well managed perennial ryegrass-only farmlet (‘Ryegrass Max’, RM). The CF farmlet included perennial ryegrass pasture (44% of the farmlet area on average over 4 years), but also incorporated oversowing perennial ryegrass with short-term ryegrasses (average 16% of farmlet area) to increase winter growth, tall fescue-based pasture (average 20% of farmlet area) to increase production in the late spring–summer period, a double cropping rotation (15% of farmlet area) based on winter cereal for silage production followed by summer brassica crops for grazing, and summer crops used in the pasture renovation process (average 5% of farmlet area). The RM and CF farmlets were stocked at 2.2 and 2.82 June-calving cows/ha, respectively and average annual nitrogen (N) fertiliser application rates (pasture only) were 141 and 153 kg N/ha, respectively. The total amount of forage harvested per year was generally less than predicted from pre-experimental modelling of both farmlets. However, the proposed target of a 30% increase in home-grown forage harvest per ha in the CF system compared with RM was exceeded in 2005–06 (+33%), with 21, 16 and 11% higher forage harvest achieved in CF in 2006–07, 2007–08 and 2008–09, respectively (average for all 4 years = 20%). Annual forage harvested in RM ranged between 6.5 and 8.9 t DM/ha compared with 7.9–10.3 t DM/ha in CF. Approximately two-thirds of the increased forage harvest in CF came from higher rates of pasture consumption per ha and one-third from the double cropping component of the system, although the performance of the double crop (mean annual production of 11.5 t DM/ha) was well below the expected 20 t DM/ha based on pre-experimental modelling. The higher per-hectare pasture harvest rates in CF were primarily due to increased perennial ryegrass pasture consumption achieved through higher stocking rates and efficient responses to higher N inputs from both higher fertiliser rates and additional supplementary feeding. In CF, the DM harvested from pastures oversown with short-term ryegrasses was lower than perennial ryegrass, while tall fescue-based pastures were similar to perennial ryegrass. Poor spring rainfall in 2006–07 and 2008–09 likely contributed to the lower than expected DM yields of tall fescue-based pasture and the summer crops within the double cropping component. Home-grown forage harvest rates can be increased by 11–33% above what is currently achieved by best industry practice with perennial ryegrass-only pastures using complementary forages but perennial ryegrass will remain a key component of the forage base for dairy production in southern Australia.
Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 3. Intake, milk production and composition, bodyweight and body condition score
Authors: Hill J. , Chapman D. F. , Tharmaraj J. , Jacobs J. L. , Cullen B. R.
Published: January 2014

This paper reports the performance [intake, milk production, bodyweight and body condition score (BCS)] of cows managed under two feeding systems over 4 years (June 2005–May 2009) in south-west Victoria, Australia. The feeding systems were ‘Ryegrass Max’ (RM) a well managed perennial ryegrass pasture-based system stocked at 2.2 cows/ha, and a ‘Complementary Forage’ (CF) system based on perennial ryegrass, tall fescue and a double crop of winter-sown cereal and summer-sown brassica crops stocked at 2.82 cows/ha. There were no significant differences in milk production per lactation between feeding systems, with an average of 543 and 553 kg milk solids per cow (1246 and 1642 kg milk solids per ha) produced in the RM and CF systems, respectively. These production levels were 20.9 and 10.8% above pre-experimental model targets, respectively. The bodyweight and BCS of multiparous cows were not significantly different between the two feeding systems; however, bodyweight of heifers in early lactation declined more rapidly in the CF compared with RM feeding system. Over the 4-year study in the RM system pasture comprised 60% of total DM consumed (grazed + conserved), with 26% of the ration being concentrate and the balance being purchased hay supplements. In the CF system, home-grown forage contributed 57.9% of total DM consumed of which 46.6% was pasture (grazed + conserved) and 11.3% was from the double cropping system. These levels of home-grown forage consumption were lower than those predicted by the pre-experimental modelling, leading to higher than predicted levels of purchased concentrates and conserved forages being fed. The lower than expected levels of consumption of the forages produced in the double cropping system reflected both the low intake potential and moderate nutritive value of cereal silage, and the failure of establishment and subsequent low DM yields from the summer brassica crop. Further work is required to determine the risk of implementing CF in rain-fed dairy systems reflecting uncertainties in forage management planning and nutrient delivery to support high levels of milk production.
Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 4. Economic performance
Authors: Chapman D. F. , Beca D. , Hill J. , Tharmaraj J. , Jacobs J. L. , Cullen B. R.
Published: January 2014

The profitability of dairy farm systems in southern Australia is closely related to the amount of pasture grown and consumed on-farm by dairy cows. However, there are doubts regarding the extent to which gains in feed supply from perennial ryegrass pasture can continue to support productivity growth in the industry. A farmlet experiment was conducted in south-western Victoria for 4 years (June 2005–May 2009), comparing a production system based on the use of forage species that complement perennial ryegrass in their seasonal growth pattern (‘Complementary Forages’, or CF) with a well managed system solely based on perennial ryegrass pasture (‘Ryegrass Max’, or RM). The forage base in CF included perennial ryegrass with a double-cropping rotation of winter cereal grown for whole-crop silage, followed by a summer brassica for grazing on 15% of farmlet area, a summer-active pasture based on tall fescue (on average 20% of farmlet area), perennial ryegrass oversown with short-rotation ryegrasses (average 16% of farmlet area) and summer brassica crops used in the process of pasture renovation (average 5% of farmlet area). The stocking rate was 2.2 and 2.8 cows/ha on RM and CF, respectively. Both systems were profitable over the 4 years of the experiment, with the modified internal rate of return over 4 years being 14.4% and 14.7% for the RM and CF farmlets, respectively. The coefficient of variation (%) of annual operating profit over 4 years was higher for the CF farmlet (56% and 63% for RM and CF, respectively). A severe drought in one of the 4 years exposed the more highly stocked CF system to greater supplementary feed costs and business risk. By comparison, the RM system performed consistently well across different seasons and in the face of a range of milk prices. The very small gain in profit from CF, plus the associated higher risk, makes it difficult to endorse a substantial change away from the traditional RM feed supply to greater reliance on summer-grown forages on non-irrigated dairy farms in southern Australia, as implemented in this experiment.
Dynamics transitions at the outer vestibule of the KcsA potassium channel during gating
Authors: Raghuraman H. , Islam Shahidul M. , Mukherjee Soumi , Roux Benoit , Perozo Eduardo
Published: January 2014

Significance

C-type inactivation gating in K
+
channels plays an important role in controlling the firing patterns of excitable cells and is fundamental in determining the length and frequency of the cardiac action potential. At a molecular level, toxins, blockers, and metal ions bind to the outer vestibule and modulate the functional behavior of K
+
channels. Using KcsA, we show that the shuttling between the inactivated and conductive states of K
+
channels is accompanied by changes in local outer vestibule dynamics, in the absence of large conformational changes. The altered structural and hydration dynamics of the outer vestibule appear to be likely and important modulators of selectivity filter gating transitions in K
+
channels.
Extending multipliers of the Fourier algebra from a subgroup
Authors: Brannan Michael , Forrest Brian
Published: January 2014

In this paper, we consider various extension problems associated with elements in the closure with respect to either the multiplier norm or the completely bounded multiplier norm of the Fourier algebra of a locally compact group. In particular, we show that it is not always possible to extend an element in the closure with respect to the multiplier norm of the Fourier algebra of the free group on two generators to a multiplier of the Fourier algebra of

S
L
(
2
,

R

)

SL(2,\mathbb {R})

.
On the computation of algebraic modular forms on compact inner forms of 𝐆𝐒𝐩₄
Authors: Dembélé Lassina
Published: January 2014

In this paper, we describe an algorithm for computing algebraic modular forms on compact inner forms of

G
S
p

4

\mathrm {GSp}_4

over totally real number fields. By analogues of the Jacquet-Langlands correspondence for

G
L

2

\mathrm {GL}_2

, this algorithm in fact computes Hecke eigensystems of Hilbert-Siegel modular forms of genus 2. We give some examples of such eigensystems over

Q

(

2

)

\mathbb {Q}(\sqrt {2})

.
SLC25A23 augments mitochondrial Ca2+uptake, interacts with MCU, and induces oxidative stress–mediated cell death
Authors: Hoffman Nicholas E. , Chandramoorthy Harish C. , Shanmughapriya Santhanam , Zhang Xueqian Q. , Vallem Sandhya , Doonan Patrick J. , Malliankaraman Karthik , Guo Shuchi , Rajan Sudarsan , Elrod John W. , Koch Walter J. , Cheung Joseph Y. , Madesh Muniswamy
Published: January 2014

Emerging findings suggest that two lineages of mitochondrial Ca2+uptake participate during active and resting states: 1) the major eukaryotic membrane potential–dependent mitochondrial Ca2+uniporter and 2) the evolutionarily conserved exchangers and solute carriers, which are also involved in ion transport. Although the influx of Ca2+across the inner mitochondrial membrane maintains metabolic functions and cell death signal transduction, the mechanisms that regulate mitochondrial Ca2+accumulation are unclear. Solute carriers—solute carrier 25A23 (SLC25A23), SLC25A24, and SLC25A25—represent a family of EF-hand–containing mitochondrial proteins that transport Mg-ATP/Pi across the inner membrane. RNA interference–mediated knockdown of SLC25A23 but not SLC25A24 and SLC25A25 decreases mitochondrial Ca2+uptake and reduces cytosolic Ca2+clearance after histamine stimulation. Ectopic expression of SLC25A23 EF-hand–domain mutants exhibits a dominant-negative phenotype of reduced mitochondrial Ca2+uptake. In addition, SLC25A23 interacts with mitochondrial Ca2+uniporter (MCU; CCDC109A) and MICU1 (CBARA1) while also increasing IMCU. In addition, SLC25A23 knockdown lowers basal mROS accumulation, attenuates oxidant-induced ATP decline, and reduces cell death. Further, reconstitution with short hairpin RNA–insensitive SLC25A23 cDNA restores mitochondrial Ca2+uptake and superoxide production. These findings indicate that SLC25A23 plays an important role in mitochondrial matrix Ca2+influx.
Depletion of the protein kinase VRK1 disrupts nuclear envelope morphology and leads to BAF retention on mitotic chromosomes
Authors: Molitor Tyler P. , Traktman Paula
Published: January 2014

Barrier to autointegration factor (BAF), which is encoded by the BANF1 gene, binds with high-affinity to double-stranded DNA and LEM domain–containing proteins at the nuclear periphery. A BANF1 mutation has recently been associated with a novel human progeria syndrome, and cells from these patients have aberrant nuclear envelopes. The interactions of BAF with its DNA- and protein-binding partners are known to be regulated by phosphorylation, and previously we validated BAF as a highly efficient substrate for the VRK1 protein kinase. Here we show that depletion of VRK1 in MCF10a and MDA-MB-231 cells results in aberrant nuclear architecture. The immobile fraction of green fluorescent protein (GFP)–BAF at the nuclear envelope (NE) is elevated, suggesting that prolonged interactions of BAF with its binding partners is likely responsible for the aberrant NE architecture. Because detachment of BAF from its binding partners is associated with NE disassembly, we performed live-imaging analysis of control and VRK1-depleted cells to visualize GFP-BAF dynamics during mitosis. In the absence of VRK1, BAF does not disperse but instead remains chromosome bound from the onset of mitosis. VRK1 depletion also increases the number of anaphase bridges and multipolar spindles. Thus phosphorylation of BAF by VRK1 is essential both for normal NE architecture and proper dynamics of BAF–chromosome interactions during mitosis. These results are consistent with previous studies of the VRK/BAF signaling axis in Caenorhabditis elegans and Drosophila melanogaster and validate VRK1 as a key regulator of NE architecture and mitotic chromosome dynamics in mammalian cells.
The Rebel Barons of 1264 and the Commune of London: An Oath of Mutual Aid
Authors: Stone Ian
Published: January 2014

In March 1264, the commune of London, led by its mayor Thomas fitz Thomas, allied with twenty other leading rebels to swear an oath of mutual support. This oath was mentioned by one contemporary chronicler. This article transcribes and translates this hitherto unpublished oath. It examines the significance of the agreement the rebels entered into, which was sworn just six weeks before the battle of Lewes. It analyses the text, placing it alongside other contemporary oaths in order to understand more fully its contents. Through detailed study of the oath’s unique witness list, it seeks to shed new light on the motivations and sympathies of many leading rebels of the day. Lastly, the article discusses what can be learnt about the attitudes of one of the leading chroniclers of the period of baronial reform and rebellion.
The basic keratin 10-binding domain of the virulence-associated pneumococcal serine-rich protein PsrP adopts a novel MSCRAMM fold
Authors: Schulte Tim , Löfling Jonas , Mikaelsson Cecilia , Kikhney Alexey , Hentrich Karina , Diamante Aurora , Ebel Christine , Normark Staffan , Svergun Dmitri , Henriques-Normark Birgitta , Achour Adnane
Published: January 2014

Streptococcus pneumoniaeis a major human pathogen, and a leading cause of disease and death worldwide. Pneumococcal invasive disease is triggered by initial asymptomatic colonization of the human upper respiratory tract. The pneumococcal serine-rich repeat protein (PsrP) is a lung-specific virulence factor whose functional binding region (BR) binds to keratin-10 (KRT10) and promotes pneumococcal biofilm formation through self-oligomerization. We present the crystal structure of the KRT10-binding domain of PsrP (BR187–385) determined to 2.0 Å resolution. BR187–385adopts a novel variant of the DEv-IgG fold, typical for microbial surface components recognizing adhesive matrix molecules adhesins, despite very low sequence identity. An extended β-sheet on one side of the compressed, two-sided barrel presents a basic groove that possibly binds to the acidic helical rod domain of KRT10. Our study also demonstrates the importance of the other side of the barrel, formed by extensive well-ordered loops and stabilized by short β-strands, for interaction with KRT10.
Reclassification of Leuconostoc gasicomitatum as Leuconostoc gelidum subsp. gasicomitatum comb. nov., description of Leuconostoc gelidum subsp. aenigmaticum subsp. nov., designation of Leuconostoc gelidum subsp. gelidum subsp. nov. and emended description of Leuconostoc gelidum
Authors: Rahkila Riitta , De Bruyne Katrien , Johansson Per , Vandamme Peter , Björkroth Johanna
Published: January 2014

In the present study we investigated the taxonomic status of 20 lactic acid bacteria (LAB) originating from packaged meat. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the genus

Leuconostoc

with

Leuconostoc gelidum

,

Leuconostoc inhae

and

Leuconostoc gasicomitatum

as the closest phylogenetic relatives. The novel strains shared more than 70 % DNA–DNA relatedness with type and reference strains of both

L. gelidum

and

L. gasicomitatum

. The DNA–DNA relatedness values between

L. gelidum

type and reference strains and

L. gasicomitatum

type and reference strains were also above 70 %, showing that all these strains belonged to the same species. Sequence analyses of concatenated atpA, pheS, and rpoA genes demonstrated that the novel strains as well as type and reference strains of

L. gelidum

and

L. gasicomitatum

are phylogenetically closely related, but form three clearly separated subgroups. Numerical analysis of HindIII ribopatterns and phenotypic tests supported this subdivision. Based on the data presented in this study, we propose to reclassify

Leuconostoc gasicomitatum

as Leuconostoc gelidum subsp. gasicomitatum comb. nov. (type strain, LMG 18811T = DSM 15947T). The novel strains isolated in the present study represent a novel subspecies, for which the name Leuconostoc gelidum subsp. aenigmaticum subsp. nov. is proposed, with POUF4dT ( = LMG 27840T = DSM 19375T) as the type strain. The proposal of these two novel subspecies automatically creates the subspecies Leuconostoc gelidum subsp. gelidum subsp. nov. (type strain, NCFB 2775T = DSM 5578T). An emended description of

Leuconostoc gelidum

is also provided.
Risk factors associated with Chlamydia psittaci infection in psittacine birds
Authors: Santos F. , Leal D. C. , Raso T. F. , Souza B. M. P. S. , Cunha R. M. , Martinez V. H. R. , Barrouin-Melo S. M. , Franke C. R.
Published: January 2014

Chlamydia psittaci is the aetiological agent of chlamydiosis in birds, especially Psittaciformes. The objective of the present study was to detect C. psittaci by means of semi-nested PCR among psittacine birds sold at pet markets and kept as pet birds in Salvador, Bahia, Brazil. Questionnaires were used to identify risk factors involved in the epidemiology of the disease. In addition, the management of birds and cages was observed at each location studied. The frequency of C. psittaci infection was 10.6 % (33/311) in the psittacine birds studied. Birds kept in households were less frequently positive (3.4 %; 5/148) than those at pet markets (17.2 %; 28/163). Among the several factors analysed in the epidemiology of the disease, only population density (P = 0.001) and cage hygiene (P = 0.041) in birds at pet markets were significantly associated with C. psittaci infection. These results demonstrate the presence of C. psittaci infection in Psittaciformes kept as pets and held at pet markets in Salvador, Bahia, showing that this micro-organism is a public health concern. Control measures should be encouraged to prevent the spread of the agent among birds, as well as among employees and customers.
Propensity for biofilm formation by clinical isolates from urinary tract infections: developing a multifactorial predictive model to improve antibiotherapy
Authors: Alves Maria José , Barreira João C. M. , Carvalho Inês , Trinta Luis , Perreira Liliana , Ferreira Isabel C. F. R. , Pintado Manuela
Published: January 2014

A group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2 %) were biofilm producers. The bacterial species (P<0.001), together with patient’s gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of catheterization with biofilm formation, despite being less significant (P = 0.070) than species or gender. In fact, some of the bacteria isolated were biofilm producers in all cases. With regard to resistance profile among bacterial isolates, β-lactam antibiotics presented the highest number of cases/percentages – ampicillin (32/55.2 %), cephalothin (30/51.7 %), amoxicillin/clavulanic acid (22/37.9 %) – although the carbapenem group still represented a good therapeutic option (2/3.4 %). Quinolones (nucleic acid synthesis inhibitors) also showed high resistance percentages. Furthermore, biofilm production clearly increases bacterial resistance. Almost half of the biofilm-producing bacteria showed resistance against at least three different groups of antibiotics. Bacterial resistance is often associated with catheterization. Accordingly, intrinsic (age and gender) and extrinsic (hospital unit, bacterial isolate and catheterization) factors were used to build a predictive model, by evaluating the contribution of each factor to biofilm production. In this way, it is possible to anticipate biofilm occurrence immediately after bacterial identification, allowing selection of a more effective antibiotic (among the susceptibility options suggested by the antibiogram) against biofilm-producing bacteria. This approach reduces the putative bacterial resistance during treatment, and the consequent need to adjust antibiotherapy.
Mechanism of phosphate solubilization and antifungal activity of Streptomyces spp. isolated from wheat roots and rhizosphere and their application in improving plant growth
Authors: Jog Rahul , Pandya Maharshi , Nareshkumar G. , Rajkumar Shalini
Published: January 2014

The application of plant-growth-promoting rhizobacteria (PGPR) at field scale has been hindered by an inadequate understanding of the mechanisms that enhance plant growth, rhizosphere incompetence and the inability of bacterial strains to thrive in different soil types and environmental conditions. Actinobacteria with their sporulation, nutrient cycling, root colonization, bio-control and other plant-growth-promoting activities could be potential field bio-inoculants. We report the isolation of five rhizospheric and two root endophytic actinobacteria from Triticum aestivum (wheat) plants. The cultures exhibited plant-growth-promoting activities, namely phosphate solubilization (1916 mg l−1), phytase (0.68 U ml−1), chitinase (6.2 U ml−1), indole-3-acetic acid (136.5 mg l−1) and siderophore (47.4 mg l−1) production, as well as utilizing all the rhizospheric sugars under test. Malate (50–55 mmol l−1) was estimated in the culture supernatant of the highest phosphate solublizer, Streptomyces mhcr0816. The mechanism of malate overproduction was studied by gene expression and assays of key glyoxalate cycle enzymes – isocitrate dehydrogenase (IDH), isocitrate lyase (ICL) and malate synthase (MS). The significant increase in gene expression (ICL fourfold, MS sixfold) and enzyme activity (ICL fourfold, MS tenfold) of ICL and MS during stationary phase resulted in malate production as indicated by lowered pH (2.9) and HPLC analysis (retention time 13.1 min). Similarly, the secondary metabolites for chitinase-independent biocontrol activity of Streptomyces mhcr0817, as identified by GC-MS and 1H-NMR spectra, were isoforms of pyrrole derivatives. The inoculation of actinobacterial isolate mhce0811 in T. aestivum (wheat) significantly improved plant growth, biomass (33 %) and mineral (Fe, Mn, P) content in non-axenic conditions. Thus the actinobacterial isolates reported here were efficient PGPR possessing significant antifungal activity and may have potential field applications.
Triplet amino acids located at positions 145/146/147 of the RNA polymerase of very virulent infectious bursal disease virus contribute to viral virulence
Authors: Gao Li , Li Kai , Qi Xiaole , Gao Honglei , Gao Yulong , Qin Liting , Wang Yongqiang , Shen Nan , Kong Xiangang , Wang Xiaomei
Published: January 2014

Infectious bursal disease virus (IBDV) causes an economically significant disease of chickens worldwide. The emergence of very virulent IBDV (vvIBDV) has brought more challenges for effective prevention of this disease. The molecular basis for the virulence of vvIBDV is not fully understood. In this study, 20 IBDV strains were analysed phylogenically and clustered in three branches based on their full-length B segments. The amino acid triplet located at positions 145/146/147 of VP1 was found highly conserved in branch I non-vvIBDVs as asparagine/glutamic acid/glycine (NEG), in branch II vvIBDVs as threonine/glutamic acid/glycine (TEG) and in branch III vvIBDVs as threonine/aspartic acid/asparagine (TDN). Further studies showed that the three amino acids play a critical role in the replication and pathogenicity of vvIBDV. Substitution of the TDN triplet with TEG or NEG reduced viral replication and pathogenicity of the vvIBDV HuB-1 strain in chickens. However, the replication of the attenuated IBDV Gt strain was reduced in chicken embryo fibroblast cells, whilst it was enhanced in the bursa by substituting NEG with TEG or TDN. The exchange of the three amino acids was also found to be capable of affecting the polymerase activity of VP1. The important role of segment B in the pathogenicity of IBDV was confirmed in this study. These results also provided new insights into the mechanism of the virulence of vvIBDVs and may offer new targets for their attenuation to develop potential vaccines using reverse genetics.