bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlling systems that drift through a tipping point
Authors: Nishikawa Takashi , Ott Edward
Published: July 2014

Slow parameter drift is common in many systems (e.g., the amount of greenhouse gases in the terrestrial atmosphere is increasing). In such situations, the attractor on which the system trajectory lies can be destroyed, and the trajectory will then go to another attractor of the system. We consider the case where there are more than one of these possible final attractors, and we ask whether we can control the outcome (i.e., the attractor that ultimately captures the trajectory) using only small controlling perturbations. Specifically, we consider the problem of controlling a noisy system whose parameter slowly drifts through a saddle-node bifurcation taking place on a fractal boundary between the basins of multiple attractors. We show that, when the noise level is low, a small perturbation of size comparable to the noise amplitude applied at a single point in time can ensure that the system will evolve toward a target attracting state with high probability. For a range of noise levels, we find that the minimum size of perturbation required for control is much smaller within a time period that starts some time after the bifurcation, providing a “window of opportunity” for driving the system toward a desirable state. We refer to this procedure as tipping point control.
On transition from Alfvén resonance to forced magnetic reconnection
Authors: Luan Q. , Wang X.
Published: July 2014

We revisit the transition from Alfvén resonance to forced magnetic reconnection with a focus on the property of their singularities. As the driven frequency tends to zero, the logarithmic singularity of Alfvén resonance shifts to the power-law singularity of forced reconnection, due to merging of the two resonance layers. The transition criterion depends on either kinetic effects or dissipations that resolve the singularity. As an example, a small but finite resistivity η is introduced to investigate the transition process. The transition threshold is then obtained as the driven frequency reaches a level of ∼O((η/k)1/3).
Spin-orbit coupling and the static polarizability of single-wall carbon nanotubes
Authors: Diniz Ginetom S. , Ulloa Sergio E.
Published: July 2014

We calculate the static longitudinal polarizability of single-wall carbon tubes in the long wavelength limit taking into account spin-orbit effects. We use a four-orbital orthogonal tight-binding formalism to describe the electronic states and the random phase approximation to calculate the dielectric function. We study the role of both the Rashba as well as the intrinsic spin-orbit interactions on the longitudinal dielectric response, i.e., when the probing electric field is parallel to the nanotube axis. The spin-orbit interaction modifies the nanotube electronic band dispersions, which may especially result in a small gap opening in otherwise metallic tubes. The bandgap size and state features, the result of competition between Rashba and intrinsic spin-orbit interactions, result in drastic changes in the longitudinal static polarizability of the system. We discuss results for different nanotube types and the dependence on nanotube radius and spin-orbit couplings.
Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium
Authors: Singh Dharodi Vikram , Kumar Tiwari Sanat , Das Amita
Published: July 2014

A generalized hydrodynamic model depicting the behaviour of visco-elastic fluids has often been invoked to explore the behaviour of a strongly coupled dusty plasma medium below their crystallization limit. The model has been successful in describing the collective normal modes of the strongly coupled dusty plasma medium observed experimentally. The paper focuses on the study of nonlinear dynamical characteristic features of this model. Specifically, the evolution of coherent vorticity patches is being investigated here within the framework of this model. A comparison with Newtonian fluids and molecular dynamics simulations treating the dust species interacting through the Yukawa potential has also been presented.
Pressure modulated changes in resonance frequency of microchannel string resonators
Authors: Khan M. F. , Knowles B. , Dennison C. R. , Ghoraishi M. S. , Thundat T.
Published: July 2014

Resonating strings have shown promise in a variety of applications including micron-scale mass and temperature sensors. We present microchannel string resonators (MSRs) which have resonance frequency modulated by the internal gauge pressure of silicon nitride microchannels sitting atop the strings. We present an analytical model to predict the pressure sensitivity (Hz/kPa) of the first resonance frequency as well as experimental results for three identical MSRs. While the highest experimental sensitivity of one of the resonators is 5.19 Hz/kPa (0.5 Hz/mbar), the analytical model suggests sensitivity could increase by two orders of magnitude if the microchannels are fabricated at nanometer scale with a length of 10 μm, a channel width of 600 nm, and a channel thickness of 50 nm. The average pressure resolution of the sensors is 0.4 kPa. These results are for a calibrated range of pressure from 50 kPa to 100 kPa (500 mbar to 1000 mbar). However, the analytical model shows that resonance frequency is a linear function of pressure over a range of several MPa, suggesting that the microchannel resonators could have a pressure sensing range (dynamic range) suitable for many applications.
Doping efficiency of single and randomly stacked bilayer graphene by iodine adsorption
Authors: Kim HoKwon , Renault Olivier , Tyurnina Anastasia , Simonato Jean-Pierre , Rouchon Denis , Mariolle Denis , Chevalier Nicolas , Dijon Jean
Published: July 2014

We report on the efficiency and thermal stability of p-doping by iodine on single and randomly stacked, weakly coupled bilayer polycrystalline graphene, as directly measured by photoelectron emission microscopy. The doping results in work function value increase of 0.4–0.5 eV, with a higher degree of iodine uptake by the bilayer (2%) as compared to the single layer (1%) suggesting iodine intercalation in the bilayer. The chemistry of iodine is identified accordingly as I3− and I5− poly iodide anionic complexes with slightly higher concentration of I5− in bilayer than monolayer graphene, likely attributed to differences in doping mechanisms. Temperature dependent in-situ annealing of the doped films demonstrated that the doping remains efficient up to 200 °C.
Insulating state to quantum Hall-like state transition in a spin-orbit-coupled two-dimensional electron system
Authors: Lo Shun-Tsung , Hsu Chang-Shun , Lin Y. M. , Lin S.-D. , Lee C. P. , Ho Sheng-Han , Chuang Chiashain , Wang Yi-Ting , Liang C.-T.
Published: July 2014

We study interference and interactions in an InAs/InAsSb two-dimensional electron system. In such a system, spin-orbit interactions are shown to be strong, which result in weak antilocalization (WAL) and thereby positive magnetoresistance around zero magnetic field. After suppressing WAL by the magnetic field, we demonstrate that classical positive magnetoresistance due to spin-orbit coupling plays a role. With further increasing the magnetic field, the system undergoes a direct insulator-quantum Hall transition. By analyzing the magnetotransport behavior in different field regions, we show that both electron-electron interactions and spin-related effects are essential in understanding the observed direct transition.
Recyclable surface-enhanced Raman scattering template based on nanoporous gold film/Si nanowire arrays
Authors: Zhang Chang Xing , Liu Luo , Jun Yin Hong , Fang Hui , Mei Zhao Yong , Jian Bi Chu , Jun Xu Hai
Published: July 2014

Nanoporous gold film (NPGF) composed of gold nanoparticles was used to cover a large Si nanowire array (SiNWA) by simple metal-assisted chemical etching and metal reduction processes. Three-dimensional SiNWA/NPGF was employed as an active substrate for surface-enhanced Raman scattering (SERS). The results show that the detection limit for crystal violet was as low as 10−12M, and the Raman enhancement factor was as large as 107 with a relative standard deviation of less than 20%. After calibrating the Raman peak intensities of crystal violet and thiram could be quantitatively detected. More importantly, the SERS substrates are recyclable and can be used for many gold surface adsorbates such as p-aminothiophenol, crystal violet, Rhodamine 6G, and methyl orange, which can all be rapidly and completely removed from the NPGF surface. Our findings are an important advance in SERS substrates and will allow the quantitative and recyclable detection of trace organic contaminants.
Indium tin oxide/InGaZnO bilayer stacks for enhanced mobility and optical stability in amorphous oxide thin film transistors
Authors: Chung Yoon Jang , Kim Un Ki , Hwang Eun Suk , Hwang Cheol Seong
Published: July 2014

Optically more stable, high mobility InGaZnO thin film transistors were fabricated by implementing ultrathin In2O3-SnO2 (ITO) layers at the gate dielectric/semiconductor interface. The optimized device portrayed a high saturation mobility of ∼80 cm2/V s with off current values lower than 10−11A. The ITO layer also acted as a hole filter layer, and hole current and threshold voltage shift values measured under negative bias illumination conditions showed that a significant amount of photo-generated charge carriers were annihilated before reaching the gate insulator. This effect was more evident at larger intensities, showing threshold voltage shift values reduced by more than ∼70% under stress conditions.
Island-ground single-plate electro-wetting on dielectric device for digital microfluidic systems
Authors: Cui Weiwei , Zhang Menglun , Zhang Daihua , Pang Wei , Zhang Hao
Published: July 2014

In this paper, we present a single-plate electro-wetting on dielectric (SEWOD) device by integrating an island-ground electrode (IG), which is surrounded by the driving electrodes and looks like an island. Both experiments and theoretical analysis have been conducted to investigate the performance of the IG-SEWOD device. The driving voltage of a fabricated IG-SEWOD has been measured to be 15 V, which is half of that of a floating SEWOD. The digital dynamic properties of the EWOD device are greatly enhanced due to the “double locking” effect and rapid residual charges elimination provided by the IG. The proposed EWOD device shows great potential in constructing advanced microfluidics platforms for bio-chemical detection and disease diagnosis.
Stretchable polymeric modulator for intracavity spectroscopic broadening of femtosecond optical parametric oscillators
Authors: Wang Yimeng , Zhang Xinping , Zhang Jian , Liu Hongmei
Published: July 2014

We investigate stretching-induced microscopic deformations spatially distributed in a flexible plate of polydimethylsiloxane (PDMS) and their applications in the broadening of the output spectrum of a femtosecond optical parametric oscillator. The hologram of the stretched PDMS plate was used to evaluate indirectly the microscopic deformations. The experimental results show that these deformations exhibit weak scattering and diffraction of light and induce negligible cavity loss, ensuring practical applications of the PDMS plate as an intracavity device for lasers. In combination with the thickness reduction of the PDMS plate through stretching, the distributed deformations enable smooth tuning of the output spectrum.
Coherent control of birefringence and optical activity
Authors: Mousavi Seyedmohammad A. , Plum Eric , Shi Jinhui , Zheludev Nikolay I.
Published: July 2014

We show that polarization effects due to anisotropy and chirality affecting a wave propagating through a thin slab of material can be controlled by another electromagnetic wave. No nonlinearity of the metamaterial slab is required and the control can be exercised at arbitrarily low intensities. In proof-of-principle experiments with anisotropic and chiral microwave metamaterials, we show that manifestations of linear and circular birefringence and dichroism can be modulated by the control wave from their maximum value to zero.
Direct tunneling through high-κ amorphous HfO2: Effects of chemical modification
Authors: Wang Yin , Yu Zhizhou , Zahid Ferdows , Liu Lei , Zhu Yu , Wang Jian , Guo Hong
Published: July 2014

We report first principles modeling of quantum tunneling through amorphous HfO2 dielectric layer of metal-oxide-semiconductor (MOS) nanostructures in the form of n-Si/HfO2/Al. In particular, we predict that chemically modifying the amorphous HfO2 barrier by doping N and Al atoms in the middle region—far from the two interfaces of the MOS structure—can reduce the gate-to-channel tunnel leakage by more than one order of magnitude. Several other types of modification are found to enhance tunneling or induce substantial band bending in the Si, both are not desired from leakage point of view. By analyzing transmission coefficients and projected density of states, the microscopic physics of electron traversing the tunnel barrier with or without impurity atoms in the high-κ dielectric is revealed.
Comparison of enantiomers of organic acids for their effects on methane production in vitro
Authors: Reis L. G. , Chaves A. V. , Williams S. R. O. , Moate P. J.
Published: July 2014

This study aimed to evaluate the effect of organic acids on in vitro fermentation characteristics. Four organic acids (tartaric, malic, fumaric and citric) and their enantiomers (L-tartaric, D-tartaric, DL-tartaric, L-malic and DL-malic) were analysed using in vitro batch culture incubations, at four concentrations (0, 5, 10 and 15 mM). Cumulative total gas and methane (CH4) production (mL/g DM) were measured at 6, 12 and 24 h; ammonia, pH, volatile fatty acids (VFA) and in vitro dry matter digestibility (IVDMD) were determined after 24 h of fermentation. Overall, addition of acids at 5 to 15 mM increased (P < 0.0001) cumulative gas and CH4 production. No effect (P > 0.10) of enantiomers, individual acid or interaction acid × concentration was detected at 12 and 24 h for cumulative gas or CH4 production. Addition of DL-malic, L-malic and fumaric acids increased (P < 0.0001) the percentage of propionic acid in the ruminal fluid total VFA compared with all concentrations of the other organic acids or their enantiomers. Ammonia concentration was not affected (P ≥ 0.28) by the addition of organic acids, concentrations or interactions. These findings are evidence that ruminal microorganisms can metabolise both D- and L-enantiomers of organic acids. None of the organic acids and their enantiomers at four different concentrations demonstrated potential as CH4 mitigation agents.
A systems approach to determine the effect of changes in gene expression in adipose tissue on productive and reproductive efficiency in dairy cattle
Authors: Huber K. , Kenez A. , McNamara J. P. , Shields S. L.
Published: July 2014

In order to assess the patterns of metabolism that affect efficiency, an existing mechanistic metabolic model of dairy cows (Molly) was expanded to include transcriptional control of metabolism in adipose tissue and reproductive processes. Our objective was to test the effects of changes in gene transcription in adipose tissue on patterns of metabolism, reproductive processes and efficiency. The model describes the substrate sensitivity and maximum velocity for lipogenesis, esterification and lipolysis. Data were collected from first and second parity cows from various studies, and included nutrient intake, milk component output, changes in adipose tissue lipid, visceral and body protein and lipid, and metabolism rates in adipose tissue and gene transcription. The lipogenic pathways were primarily controlled by transcriptional changes, whereas lipolysis varied primarily by post-translational control. We used the difference in transcriptional and post-translational metabolic control to alter Vmax and Ks for lipogenesis and lipolysis; in addition, we modelled a range of energy costs for ion transport and protein turnover in liver, muscle and adipose tissues. Changing rates of lipogenesis and lipolysis (~four-fold) did not affect milk production or feed intake, but altered maintenance costs, fat accretion, energetic efficiency and reproduction. Increases in lipogenesis decreased postpartum interval to first ovulation; increases in rates of lipolysis increased the interval. Changes in metabolic rate from changing either adipose tissue metabolism or rate of ion transport and protein turnover affected rates of oestrogen and progesterone degradation, which affected follicular growth and corpus luteum function. This model may be used to help interpret genomic and transcriptomic data to pinpoint the most effective ways to select and manage for changes in productive and reproductive efficiency.
Evaluation of growth hormone response to insulin-induced hypoglycaemia in dairy cattle during a 670-day lactation
Authors: Marett L. C. , Auldist M. J. , Wales W. J. , Macmillan K. L. , DiGiacomo K. , Leury B. J.
Published: July 2014

Plasma growth hormone secretion in response to insulin-induced hypoglycaemia was evaluated in cows undergoing an extended lactation. Twelve multiparous Holstein-Friesian cows that calved in late winter and were managed for a 670-day lactation by delaying mating. Four experimental periods of 40 days commenced at ~73, 217, 422 and 520 (±9.1; mean ± s.d.) days in milk (DIM) during which cows were individually offered a diet of perennial ryegrass (73 and 422 DIM) or pasture hay and pasture silage (217 and 520 DIM) supplemented with either 1 kg DM grain (CONT) or 6 kg DM grain (GRAIN). Cows were fitted with jugular catheters during the final week of each experimental period. Seven blood samples over a 24-h period were collected and an insulin tolerance test was performed on each cow using a dose of 0.12 µU insulin/kg liveweight at ~100, 250, 460 and 560 DIM. This resulted in an increase in plasma growth hormone concentration occurring at 100 DIM, an intermediate and delayed response at 250 DIM, and no response at both 460 and 560 DIM. Cows in the CONT treatment had higher basal plasma growth hormone concentrations and tended to have a greater peak growth hormone response than GRAIN cows. The growth hormone response at 100 and 250 DIM is likely a homeorhetic mechanism to support milk yield during early-mid lactation. These observations are consistent with the known actions of growth hormone to promote lipid mobilisation, hepatic glucose production and an overall state of catabolism. With further research, the insulin tolerance test may be a useful tool to identify cows with greater growth hormone secretory response and increased milk production or persistency.
Tropical cattle methane emissions: the role of natural statins supplementation
Authors: Ramírez-Restrepo C. A. , O'Neill C. J. , López-Villalobos N. , Padmanabha J. , McSweeney C.
Published: July 2014

A natural food-based supplementation in the basal diet (BD) of cattle for lowering methane emissions was conducted over a 2.5-month period in 2013 at Lansdown Research Station, in north Queensland, Australia. Using eight rumen-cannulated Belmont Red Composite steers [436 ± 18.2 kg liveweight (LW); least squares means ± s.e.m.] fed a diet mixture of 0.85 CSIRO’s Ridley beef finisher pellets and 0.15 Rhodes grass (Chloris gayana); Experiment 1 compared for 7 weeks dose-dependent effects of the fermented-Monascus purpureus red rice powder (FRR) on dry matter intake (DMI), feed efficiency and tolerability. Consistent with the developed feeding methodology, the second experiment used four (461 ± 18.2 kg LW) fistulated Belmont Red Composite steers to assess rumen fermentation parameters and methane emissions measured in an open-circuit respiratory chamber system over ~4 weeks. Overall, LW increased throughout the study. In Experiment 1, the supplementation of FRR containing a natural lovastatin (monakolin K) reached 120 g/day (i.e. 2.88 ± 0.057 mg monakolin K/kg LW) fed in two approximately equal portions at 0900 hours and 1600 hours. However, once the diet was equal to or higher than 110 g/day of FRR, adverse effects were evident in terms of DMI (P < 0.05) and animal physiology. Compared with the BD, dietary intake of 40 g of FRR/day (i.e. 0.92 ± 0.034 mg monakolin K/kg LW) was associated (P < 0.05) with increased DMI and reduced methane yield (g/kg DMI) emissions. However, the effect was transient and not observed as FRR increased to 100 g/day. It was concluded that the adverse effects of FRR on animal health precludes further investigation with high doses of supplementation, and the transient reduction in methane yield was probably due to rumen adaptation.
Characterising barrier function among regions of the gastrointestinal tract in Holstein steers
Authors: Penner G. B. , Aschenbach J. R. , Wood K. , Walpole M. E. , Kanafany-Guzman R. , Hendrick S. , Campbell J.
Published: July 2014

The objective of this study was to characterise the regional variation in the barrier function of the gastrointestinal tract in Holstein calves using the flux rates of mannitol and inulin as permeability markers and tissue conductance (Gt) as an electrophysiological indicator of barrier function. Six Holstein steer calves (6 months of age) fed a common diet were used. Calves were killed by captive bolt stunning and pithing, and tissues were collected from the rumen, omasum, duodenum, jejunum, ileum, caecum, proximal colon, and distal colon. Tissues were carefully washed using a pre-heated (38.5°C) buffer solution (pH 7.4) saturated with oxygen and then transported to the laboratory. The mucosa was prepared by hand stripping and mounted between two halves of an Ussing chamber (n = 3/region with an exposed surface area of 3.14 cm2 for rumen and omasum and 1 cm2 for all other tissues). All tissues were incubated under short-circuit conditions and exposed to a similar buffer solution except for the energy source; rumen, omasum, caecum, and colon tissues were incubated with buffer containing short-chain fatty acids while tissues from the small intestine were bathed in buffer containing glucose. The Gt and the serosal-to-mucosal flux rates of 14C-inulin and 3H-mannitol were measured as indicators of barrier function. The serosal-to-mucosal flux rate of mannitol was greatest (P < 0.001) in the jejunum [104.8 nmol/(cm2 × h)] and least in the rumen and omasum [20.3 and 18.6 nmol/(cm2 × h), respectively]. In contrast, the serosal-to-mucosal flux rate of inulin was greatest (P < 0.001) in the omasum [158.6 nmol/(cm2 × h)] followed by the rumen [87.3 nmol/(cm2 × h)] with no differences among the other regions [18.7 – 62.0 nmol/(cm2 × h)]. The Gt was greatest (P < 0.001) in the jejunum (34.6 mS/cm2) and least for the rumen (3.67 mS/cm2) and omasum (3.23 mS/cm2). The Gt was correlated with both inulin and mannitol flux rates in duodenum, caecum and proximal colon (P < 0.05); whereas, no such correlations existed in jejunum, ileum and distal colon. The Gt was correlated with the mannitol flux rate but not the inulin flux rate in rumen and omasum. For all regions but the rumen and omasum there was a positive correlation between mannitol and inulin flux rates. These data indicate that the translocation of a large molecule (inulin) across the omasum and rumen is greatest despite having an apparently tight epithelium based on Gt and mannitol flux rate, while the jejunum appears to have greatest potential for paracellular permeability.
Price risk exposure of Australian Merinos – is it in the bloodline?
Authors: Behrendt Karl
Published: July 2014

Sheep producers and their advisors utilise Australian Merino bloodline trial data to guide future sheep breeding objectives and ram selection. To adequately assess the economic outcomes from different bloodlines in the decision making process, there is a need to consider the impact of wool and sheep meat price risk. Using a steady-state wether flock model that accounts for the lifetime productivity of 268 reported Merino bloodlines and stochastic dependency in weekly wool and sheep meat prices from 28 June 2005 to 10 November 2011, gross incomes per dry sheep equivalent (GI/DSE) were calculated for a weekly time step. The analysis found that across all bloodlines and market price scenarios, GI/DSE ranged between AU$13.92 and AU$67.83, with an overall mean of AU$32.60. The individual means of bloodlines across the time series ranged from AU$37.46 to AU$25.19 GI/DSE. The coefficient of variation, used as the measure of relative risk for each bloodline, ranged from 0.24 to 0.30 with a mean of 0.25. The analysis showed that a bloodlines exposure to price risk has a curvilinear relationship to fibre diameter and fleece weight. The results from a risk-reward point of view indicate that the majority of Australian Merino bloodlines are risk-inefficient. This suggests Australian sheep producers have a significant opportunity to increase net returns and reduce price risk exposure by identifying and switching to more risk-efficient bloodlines.
Sheep of divergent genetic merit for wool growth do not differ in digesta kinetics while on restricted intakes
Authors: De Barbieri I. , Hegarty R. S. , Oddy V. H. , Barnett M. C. , Li L. , Nolan J. V.
Published: July 2014

Sheep selected for high wool growth were previously shown to exhibit higher microbial protein outflow from the rumen and higher uptake of amino nitrogen in portal blood than those selected for low wool growth. This suggests that genetic selection for wool growth may induce changes in foregut physiology. This study was undertaken to determine whether differences in digesta kinetics, especially mean retention mime (MRT), are associated with differences in fleece production between sheep with low or high estimated breeding values (EBVs) for fleece weight. Twenty mature Merino wethers with uniform EBVs for liveweight were allocated to two groups of 10 animals on the basis of high or low EBVs for yearling fleece weight. Five sheep with low-EBVs and five sheep with high-EBVs for fleece weight groups were allocated in a crossover design to low and high feeding-level treatments, which comprised a blended hay diet fed at maintenance or 1.5 times maintenance. All sheep were given single doses of chromium-mordanted fibre and cobalt-EDTA as inert, non-digestible markers. Digesta kinetics was determined by analysis of the faecal marker excretion patterns using a compartmental model. Higher feed intakes from animals fed 1.5 times maintenance were associated with higher rates of wool growth and higher masses of indigestible fibre in the gut, but reduced MRT of digesta. Although sheep with higher EBVs for fleece weight had higher wool growth rates, there was no indication that these wool growth differences were associated with differences in digesta kinetics. The lack of interaction between feeding level and genotype suggests that MRT did not contribute to genotype differences in wool growth in sheep fed restricted intakes. The differences in wool growth among commercial Merino sheep with divergent fleece weight EBVs achieved by multi-trait selection are not attributable to differences in digesta kinetics, at least when feed is not available ad libitum.
Cysteamine hydrochloride increases bodyweight and wool fibre length, improves feed conversion ratio and reduces methane yield in sheep
Authors: Barnett M. C. , Hegarty R. S.
Published: July 2014

Developing processes which reduce enteric methane production without compromising animal productivity has become critical for sustainable livestock production. It was hypothesised that administrating cysteamine hydrochloride (CSH) to sheep would decrease methane yield (MY) and plasma concentration of somatostatin (SRIF) while increasing bodyweight gain (BWG) and daily wool growth. In the first experiment, 30 Merino × Dorset lambs were randomly divided into three groups receiving different dosages of CSH; 0 mg/kg BW, 80 mg/kg BW daily, or 80 mg/kg BW every third day; for a period of 35 days. The effect on BWG, feed conversion ratio (FCR), daily wool growth, voluntary feed intake (VFI), and MY (g CH4/kg DM intake) were studied. Treatment with CSH daily increased BWG (P < 0.05) and daily wool growth (P < 0.05), improved FCR (P = 0.01), and reduced MY (P < 0.01). Administering CSH every 3 days increased BWG (P < 0.05) and reduced MY (P < 0.01). There was no CSH effect on VFI. In the second experiment, CSH equivalent to 80 mg/kg BW was administered once to eight Merino × Dorset lambs. Blood samples were collected at –24, –16, 0, 2, 8, 24, and 48 h of administration. Plasma concentrations of SRIF were significantly reduced (P < 0.01) within 2 h of CSH ingestion and remained at reduced levels 48 h after administration. These results show that CSH rapidly reduces plasma SRIF concentration, which is likely to leading to an increase in animal production traits while reducing enteric MY. This experiment constitutes a novel and potentially significant investigation into the control of livestock greenhouse gas emissions while increasing livestock productivity.
The fossilized birth–death process for coherent calibration of divergence-time estimates
Authors: Heath Tracy A. , Huelsenbeck John P. , Stadler Tanja
Published: July 2014

Significance

Divergence time estimation on an absolute timescale requires external calibration information, which typically is derived from the fossil record. The common practice in Bayesian divergence time estimation involves applying calibration densities to individual nodes. Often, these priors are arbitrarily chosen and specified yet have an excessive impact on estimates of absolute time. We introduce the fossilized birth–death process—a fossil calibration method that unifies extinct and extant species with a single macroevolutionary model, eliminating the need for ad hoc calibration priors. Compared with common calibration density approaches, Bayesian inference under this mechanistic model yields more accurate node age estimates while providing a coherent measure of statistical uncertainty. Furthermore, unlike calibration densities, our model accommodates all the reliable fossils for a given phylogenetic dataset.
Allosteric regulation of γ-secretase activity by a phenylimidazole-type γ-secretase modulator
Authors: Takeo Koji , Tanimura Shun , Shinoda Takehiro , Osawa Satoko , Zahariev Ivan Krasmirov , Takegami Naoki , Ishizuka-Katsura Yoshiko , Shinya Naoko , Takagi-Niidome Shizuka , Tominaga Aya , Ohsawa Noboru , Kimura-Someya Tomomi , Shirouzu Mikako , Yokoshima Satoshi , Yokoyama Shigeyuki , Fukuyama Tohru , Tomita Taisuke , Iwatsubo Takeshi
Published: July 2014

Significance

For mechanism-based development of treatment for Alzheimer’s disease (AD), the precise molecular mechanism of γ-secretase modulators (GSMs), which have been extensively developed as possible therapeutic reagents, is required. Here, we analyzed the mode of actions of phenylimidazole-type GSMs using a chemical biology approach and systematic mutagenesis. We provide the first structural model, to our knowledge, that binding of the phenylimidazole-type GSMs at the luminal loop of presenilin induces a conformational change of the catalytic center to reduce toxic amyloid-β species selectively. Our results may facilitate the effective development of AD therapeutics.
Substance Use and Mental Illness among Nurses: Workplace Warning Signs and Barriers to Seeking Assistance
Authors: Cares Alexa , Pace Elizabeth , Denious Jean , Crane Lori A.
Published: July 2014

Background

Although some studies have examined the prevalence of substance use among nurses, few have assessed substance use in the workplace or early cues for identifying these health conditions. Primary data collected as part of a larger program evaluation were examined with the purpose of better understanding (a) the context and perceived consequences of substance use and mental illness among nurses and (b) barriers and opportunities for earlier identification and treatment of these issues among nurses, their colleagues, and employers.

Methods

Anonymous surveys were mailed to 441 active and recent participants of a peer health assistance program in the summer of 2010. The survey examined drug-related behaviors in the workplace; behavioral cues that may permit earlier identification of substance use and mental illness; perceptions of barriers to seeking assistance; and strategies for preventing problems and overcoming barriers to seeking assistance.

Results

Responses were received from 302 nurses (69%). Nearly half (48%) reported drug or alcohol use at work, and two fifths (40%) felt that their competency level was affected by their use. More than two thirds of respondents thought their problem could have been recognized earlier. The most highly rated barriers to seeking assistance for substance use and mental illness included fear and embarrassment and concerns about losing one's nursing license. Respondents recommended greater attention be paid to early identification of risk factors during nurses’ professional training as a prevention strategy.

Conclusions

Findings from this study provide preliminary data that can be used by schools of nursing and health care employers to improve early identification of nurses’ substance use and mental illness treatment needs. These data also suggest a need for more research to explore the prevention and early identification of co-occurring disorders in health care settings where nurses practice.
IκB kinase epsilon expression in adipocytes is upregulated by interaction with macrophages
Authors: Sanada Yohei , Kumoto Takahiro , Suehiro Haruna , Yamamoto Takafumi , Nishimura Fusanori , Kato Norihisa , Yanaka Noriyuki
Published: July 2014

Macrophage infiltration in the adipose tissue, and the interaction with adipocytes, is well documented to be involved in fat inflammation and obesity-associated complications. In this study, we isolated IκB kinase ε (IKKε) as a key adipocyte factor that is potentially affected by interaction with macrophages in adipose tissue in vivo. We showed that IKKε mRNA expression levels in white adipose tissue were increased in both genetic and diet-induced obese mouse. Furthermore, IKKε mRNA expression was decreased by the administration of vitamin B6, an anti-inflammatory vitamin, and that IKKε expression levels in adipose tissue were closely correlated with the numbers of infiltrating macrophages. In a co-culture system, we showed that IKKε expression in adipocytes was upregulated by interaction with activated macrophages. This study provides novel insight into IKKε, which is involved in adipose tissue inflammation during the development of obesity.
VASCULAR PLANT ONE-ZINC FINGER1 and VOZ2 repress the FLOWERING LOCUS C clade members to control flowering time in Arabidopsis
Authors: Yasui Yukiko , Kohchi Takayuki
Published: July 2014

Floral transition is regulated by environmental and endogenous signals. Previously, we identified VASCULAR PLANT ONE-ZINC FINGER1 (VOZ1) and VOZ2 as phytochrome B-interacting factors. VOZ1 and VOZ2 redundantly promote flowering and have pivotal roles in the downregulation of FLOWERING LOCUS C (FLC), a central repressor of flowering in Arabidopsis. Here, we showed that the late-flowering phenotypes of the voz1 voz2 mutant were suppressed by vernalization in the Columbia and FRIGIDA (FRI)-containing accessions, which indicates that the late-flowering phenotype of voz1 voz2 mutants was caused by upregulation of FLC. We also showed that the other FLC clade members, MADS AFFECTING FLOWERING (MAF) genes, were also a downstream target of VOZ1 and VOZ2 as their expression levels were also increased in the voz1 voz2 mutant. Our results suggest that the FLC clade genes integrate signals from VOZ1/VOZ2 and vernalization to regulate flowering.
Minimalist, standard and no footwear on static and dynamic postural stability following jump landing
Authors: Zech Astrid , Argubi‐Wollesen Andreas , Rahlf Anna‐Lina
Published: July 2014

In recreational sports, uncushioned, light‐weight and minimalist shoes are increasingly used to imitate barefoot situations. Uncertainty exists whether these shoes provide sufficient stability during challenging movements. In this randomised crossover study, 35 healthy distance runners performed jump landing stabilisation and single‐leg stance tests on a force plate, using four conditions in random order: barefoot, uncushioned minimalist shoes, cushioned ultraflexible shoes and standard running shoes. Ground reaction force (GRF) and centre of pressure (COP) data were used to determine unilateral jump landing stabilisation time and COP sway velocity during single‐leg stance. Repeated measures analysis of variance revealed significant footwear interactions for medial–lateral (p < 0.001) and anterior–posterior COP sway velocity during standing (p < 0.001). The barefoot condition produced significantly greater postural sway velocities (p < 0.001) compared to all footwear conditions. No significant effects were found for jump landing stabilisation time. In conclusion, the results of this study indicate that increased shoe flexibility and reduced sole support have no, or only minor influence on static and dynamic postural control, and therefore, may not increase the risk of traumatic events during sports activities. However, barefoot conditions should be considered carefully when adequate postural control is needed.
Arabs and democracy: an analysis of the findings of the survey of Arab public opinion towards democracy
Authors: Sawani Youssef Mohammad
Published: July 2014

A survey commissioned by the Center of Arab Unity Studies (CAUS), and carried out in late 2009 and early 2010, was the first Arab public opinion survey on democracy of its kind. This article presents its findings and contextualizes the analyses in the debate that has marked Arab political thinking on democracy as a system of good governance. The purpose of the survey was to shed light on the attitudes of ordinary Arabs with respect to democracy. Contrary to approaches that sought to explain the democratic deficit in the Arab world by virtue of its inherently ‘undemocratic’ culture and the Islamic religion, democratic elements are not absent from Arab culture and Arab people are yearning for democracy. The article analyses and compares the results with those of other surveys to conclude that contemporary Arabs are no exception and they have the same attitudes shared by humanity at large with respect to democracy as a solid political base for a fair system of governance.
Competitive binding-based optical DNA mapping for fast identification of bacteria - multi-ligand transfer matrix theory and experimental applications on Escherichia coli
Authors: Nilsson Adam N. , Emilsson Gustav , Nyberg Lena K. , Noble Charleston , Stadler Liselott Svensson , Fritzsche Joachim , Moore Edward R. B. , Tegenfeldt Jonas O. , Ambjörnsson Tobias , Westerlund Fredrik
Published: July 2014

We demonstrate a single DNA molecule optical mapping assay able to resolve a specific Escherichia coli strain from other strains. The assay is based on competitive binding of the fluorescent dye YOYO-1 and the AT-specific antibiotic netropsin. The optical map is visualized by stretching the DNA molecules in nanofluidic channels. We optimize the experimental conditions to obtain reproducible barcodes containing as much information as possible. We implement a multi-ligand transfer matrix method for calculating theoretical barcodes from known DNA sequences. Our method extends previous theoretical approaches for competitive binding of two types of ligands to many types of ligands and introduces a recursive approach that allows long barcodes to be calculated with standard computer floating point formats. The identification of a specific E. coli strain (CCUG 10979) is based on mapping of 50–160 kilobasepair experimental DNA fragments onto the theoretical genome using the developed theory. Our identification protocol introduces two theoretical constructs: a P-value for a best experiment-theory match and an information score threshold. The developed methods provide a novel optical mapping toolbox for identification of bacterial species and strains. The protocol does not require cultivation of bacteria or DNA amplification, which allows for ultra-fast identification of bacterial pathogens.
Characterization of stipe elongation of the mushroom Coprinopsis cinerea
Authors: Zhang Wenming , Wu Xiuxiu , Zhou Yajun , Liu Zhonghua , Zhang Wen , Niu Xin , Zhao Yan , Pei Siyu , Zhao Yang , Yuan Sheng
Published: July 2014

Previously, we observed an acid-induced short-term wall extension in Flammulina velutipes apical stipes during a 15 min period after a change from a neutral to an acidic pH. This acid-induced stipe wall extension was eliminated by heating and reconstituted by a snail expansin-like protein, although we failed to isolate any endogenous expansin-like protein from F. velutipes because of its limited 1 mm fast elongation region. In this study, we report that Coprinopsis cinerea stipes possess a 9 mm fast elongation apical region, which is suitable as a model material for wall extension studies. The elongating apical stipe showed two phases of acid-induced wall extension, an initial quick short-term wall extension during the first 15 min and a slower, gradually decaying long-term wall extension over the subsequent 2 h. After heating or protein inactivation pretreatment, apical stipes lost the long-term wall extension, retaining a slower short-term wall extension, which was reconstituted by an expansin-like snail protein. In contrast, the non-elongating basal stipes showed only a weaker short-term wall extension. We propose that the long-term wall extension is a protein-mediated process involved in stipe elongation, whereas the short-term wall extension is a non-protein mediated process not involved in stipe elongation.
Genomic sequence analysis and biological characteristics of a rescued clone of avian leukosis virus strain JS11C1, isolated from indigenous chickens
Authors: Cui Ning , Su Shuai , Chen Zimeng , Zhao Xiaomin , Cui Zhizhong
Published: July 2014

The strain JS11C1, a member of a putative new subgroup of avian leukosis virus (ALV) that is different from all six known subgroups from chickens based on Gp85 amino acid sequence comparison, was isolated from Chinese native chicken breeds in 2012. In order to further study the genome structure, biological characteristics, and the evolutionary relationship of the virus with others of known subgroups from infected chickens, we determined the complete genome sequence, constructed an infectious clone of ALV strain JS11C1, and performed comparative analysis using the whole genome sequence or elements with that of other ALVs available in GenBank. The results showed that the full-length sequence of the JS11C1 DNA provirus genome was 7707 bp, which is consistent with a genetic organization typical of a replication-competent type C retrovirus lacking viral oncogenes. The rescued infectious clone of JS11C1 showed similar growth rate and biological characteristics to its original virus. All the comparison analyses based on whole genomes support the opinion that the new isolates are relatively distantly related to any known subgroups of ALVs and might be classified as a new subgroup.
“And the BAFTA goes to […]”: the assurance role of the auditor in the film awards ceremony
Authors: Jeacle Ingrid
Published: July 2014

Purpose

– The purpose of this paper is to examine the role of the Official Scrutineer in the annual film awards ceremony of the British Academy of Film and Television Arts (BAFTA), a role currently occupied by the audit firm Deloitte. The case of BAFTA provides an illustrative example of the increasing demand for discretionary assurance services from audit firms (Free et al., 2009), which in turn is reflective of Power's (1997) “audit society”. It showcases the power of audit as a legitimating tool. The paper seeks to understand the role of the auditor as assurance provider by drawing upon Goffman's (1959) dramaturgical framework. Viewing the auditor as “performer” and a range of interested stakeholders (BAFTA voting members, sponsors, award winners and industry commentators) as the “audience”, this theoretical lens facilitates insights into the nature of assurance provision.

Design/methodology/approach

– The paper gathers interview data from within the case organization (BAFTA), it's Official Scrutineers (Deloitte), BAFTA voting members, sponsors, award winners and film industry commentators.

Findings

– Drawing on Goffman's (1959) work on impression management to inform its theoretical argumentation, the analysis of results from 36 interviews indicates that Deloitte are highly effective in delivering a successful performance to their audience; they convey a very convincing impression of trust and assurance. The paper therefore suggests the importance of performance ritual in the auditor's role as assurance provider. Additionally, it argues that such a performance may be particularly effective, in the eyes of the audience, when played by a well known audit firm.

Originality/value

– The paper highlights the expanding territorial scope of assurance provision by audit firms. By focusing on a glamorous media event, it also furthers an understanding of the role of accounting within the domain of popular culture.
Progress towards institutionalising field-wide water efficiency change
Authors: Egan Matthew
Published: July 2014

Purpose

– The purpose of this paper is to explore how a heterogeneous range of water efficiency responses were driven across a field of seven water consuming organisations in Australia at a time of acute drought conditions into the late 2000s.

Design/methodology/approach

– Semi-structured interviews were conducted with a range of individuals from 2008 to 2010.

Findings

– A loosely coordinated range of drivers motivated pervasive water efficiency responses in two of the seven case organisations. Would-be leaders sought to invoke a water efficiency field, and champion nascent logics and theorisation in order to gain some competitive advantage. There was little sense among others of any normative, mimetic or coercive pressure to adopt homogeneous practices. While the field lacked effective champions for change, an institutionalisation of novel water efficiency practices continued across the field into 2010.

Research limitations/implications

– Further research could investigate how water efficiency responses continued to develop or decline into the 2010s, and how such practices integrate with the management of other sustainability issues (including carbon).

Practical implications –

Global water resources are subject to increasing supply constraints. This paper responds by exploring how the institutionalisation of water efficiency change can be driven across a field of organisations.

Originality/value

– Relatively little is understood about “institutionalization” as an unfinished process. This paper responds by contributing an understanding of how institutional logics developed, and how theorisation for water efficiency progressed in the context of water scarcity in Australia in the late 2000s.