bluuebunny/crossref_metadata_2025 huggingface dataset:
A survey of drying‐off practices on commercial dairy farms in northern Germany and a comparison to science‐based recommendations
Authors: Bertulat Sandra , Fischer‐Tenhagen Carola , Heuwieser Wolfgang
Published: February 2015

While dry cow management is important for health, milk production and fertility information on drying‐off procedures implemented on commercial dairy farms is lacking. Current drying‐off management procedures on commercial dairy farms were evaluated using a questionnaire and results compared with recommendations given in the current literature. Ninety‐one participants from a farmer education event completed the survey. On average, cows were dried off seven weeks before calving. Only 9.9 per cent of the farms had a dry period length of five weeks or less. A continuous milking regime without dry period was not established on any farm participating in the survey. Most farmers performed an abrupt drying‐off (73.0 per cent). Only 11.8 and 15.0 per cent attempted to lower milk yield prior to drying‐off by reducing milking frequencies and adjusting feed rations, respectively. While a blanket antibiotic dry cow treatment was carried out on 79.6 per cent of the farms, selective dry cow treatment was not mentioned by any farmer. Although 77.4 per cent preponed the drying‐off date in low‐yielding cows, an altered drying‐off procedure in high‐yielding dairy cows was rare (9.7 per cent). This survey provides an insight into drying‐off procedures currently applied on commercial dairy farms in northern Germany.
Endemic zoonoses in the tropics: a public health problem hiding in plain sight
Authors: Halliday Jo E. B. , Allan Kathryn J. , Ekwem Divine , Cleaveland Sarah , Kazwala Rudovick R. , Crump John A.
Published: February 2015

Zoonotic diseases are a significant burden on animal and human health, particularly in developing countries. Despite recognition of this fact, endemic zoonoses often remain undiagnosed in people, instead being mistaken for febrile diseases such as malaria. Here, as part of Veterinary Record 's ongoing series of articles on One Health, a multidisciplinary team of researchers from Scotland, Tanzania and New Zealand argues that a One Health approach is needed to effectively combat these diseases
A P300 Brain–Computer Interface Based on a Modification of the Mismatch Negativity Paradigm
Authors: Jin Jing , Sellers Eric W , Zhou Sijie , Zhang Yu , Wang Xingyu , Cichocki Andrzej
Published: February 2015

The P300-based brain–computer interface (BCI) is an extension of the oddball paradigm, and can facilitate communication for people with severe neuromuscular disorders. It has been shown that, in addition to the P300, other event-related potential (ERP) components have been shown to contribute to successful operation of the P300 BCI. Incorporating these components into the classification algorithm can improve the classification accuracy and information transfer rate (ITR). In this paper, a single character presentation paradigm was compared to a presentation paradigm that is based on the visual mismatch negativity. The mismatch negativity paradigm showed significantly higher classification accuracy and ITRs than a single character presentation paradigm. In addition, the mismatch paradigm elicited larger N200 and N400 components than the single character paradigm. The components elicited by the presentation method were consistent with what would be expected from a mismatch paradigm and a typical P300 was also observed. The results show that increasing the signal-to-noise ratio by increasing the amplitude of ERP components can significantly improve BCI speed and accuracy. The mismatch presentation paradigm may be considered a viable option to the traditional P300 BCI paradigm.
Artificial Neuron–Glia Networks Learning Approach Based on Cooperative Coevolution
Authors: Mesejo Pablo , Ibáñez Oscar , Fernández-Blanco Enrique , Cedrón Francisco , Pazos Alejandro , Porto-Pazos Ana B.
Published: February 2015

Artificial Neuron–Glia Networks (ANGNs) are a novel bio-inspired machine learning approach. They extend classical Artificial Neural Networks (ANNs) by incorporating recent findings and suppositions about the way information is processed by neural and astrocytic networks in the most evolved living organisms. Although ANGNs are not a consolidated method, their performance against the traditional approach, i.e. without artificial astrocytes, was already demonstrated on classification problems. However, the corresponding learning algorithms developed so far strongly depends on a set of glial parameters which are manually tuned for each specific problem. As a consequence, previous experimental tests have to be done in order to determine an adequate set of values, making such manual parameter configuration time-consuming, error-prone, biased and problem dependent. Thus, in this paper, we propose a novel learning approach for ANGNs that fully automates the learning process, and gives the possibility of testing any kind of reasonable parameter configuration for each specific problem. This new learning algorithm, based on coevolutionary genetic algorithms, is able to properly learn all the ANGNs parameters. Its performance is tested on five classification problems achieving significantly better results than ANGN and competitive results with ANN approaches.
EFFECTS OF CORPORATE AND COUNTRY GOVERNANCE ON R&D INVESTMENT: EVIDENCE FROM EMERGING MARKETS
Authors: HASAN IFTEKHAR , RAYMAR STEVEN , SONG LIANG
Published: February 2015

We investigate how corporate governance influences R&D across 13 emerging markets. We find that superior corporate governance increases corporate R&D spending. These results suggest that corporate governance may influence management's discretion to avoid risky innovative projects. We also find that the link between firm-level governance and corporate R&D is stronger in countries with weaker country-level governance. These results suggest substitutability between firm and country governance in generating innovation activities.
Introduction
Authors: Royon Christophe
Published: February 2015

I give a brief introduction to diffraction in lepton–hadron and hadron–hadron collisions, the subject of this special issue of the International Journal of Modern Physics A.
A perturbative approach to central exclusive production
Authors: Harland-Lang L. A. , Khoze V. A. , Ryskin M. G.
Published: February 2015

We review some selected results within the Durham model of central exclusive production. We present a detailed discussion of this theoretical approach for modeling exclusive processes and we briefly review some of its phenomenological applications.
Influences of pumping schemes on the properties of dissipative soliton in fiber lasers
Authors: Chen X. D.
Published: February 2015

Based on the extended scalar nonlinear Schrödinger equation, the influences of pumping schemes on the properties of dissipative soliton are investigated theoretically in passively mode-locked ytterbium-doped fiber laser with positive dispersion cavity. Results show that, under the conditions of the same initial total gain, the dissipative solitons obtained in the backward pumping fiber laser have the narrowest spectral width, shortest pulse duration and highest pulse peak power for the forward, backward and bidirectional pumping schemes, moreover, the linear fitting degree of pulse chirp is lowest. With the same gain saturation energy, the pulse energies of the dissipative solitons are equal for three pumping schemes, but the differences of output spectra and temporal waveforms increase as the gain saturation energy increases.
High Resolution Parameter-Space from a Two-Level Model on Semi-Insulating GaAs
Authors: Da Silva S. L. , Viana E. R. , De Oliveira A. G. , Ribeiro G. M. , Da Silva R. L.
Published: February 2015

Semi-insulating Gallium Arsenide ( SI-GaAs ) samples experimentally show, under high electric fields and even at room temperature, negative differential conductivity in N-shaped form (NNDC). Since the most consolidated model for n-GaAs , namely, "the model", proposed by E. Schöll was not capable to generate the NNDC curve for SI-GaAs , in this work we have proposed an alternative model. The model proposed, "the two-valley model" is based on the minimal set of generation-recombination equations for two valleys inside of the conduction band, and an equation for the drift velocity as a function of the applied electric field, that covers the physical properties of the nonlinear electrical conduction of the SI-GaAs system. The "two-valley model" was capable to generate theoretically the NNDC region for the first time, and with that, we were able to build a high resolution parameter-space of the periodicity (PSP) using a Periodicity-Detection (PD) routine. In the parameter-space were observed self-organized periodic structures immersed in chaotic regions. The complex regions are presented in a "shrimp" shape rotated around a focal point, which forms in large-scale a "snail shell" shape, with intricate connections between different "shrimps". The knowledge of detailed information on parameter spaces is crucial to localize wide regions of smooth and continuous chaos.
Attack on a Chaos-Based Random Number Generator Using Anticipating Synchronization
Authors: Yeniçeri Ramazan , Kilinç Selçuk , Yalçin Müştak E.
Published: February 2015

Chaotic systems have been used in random number generation, owing to the property of sensitive dependence on initial conditions and hence the possibility to produce unpredictable signals. Within the types of chaotic systems, those which are defined by only one delay-differential equation are attractive due to their simple model. On the other hand, it is possible to synchronize to the future states of a time-delay chaotic system by anticipating synchronization. Therefore, random number generator (RNG), which employs such a system, might not be immune to the attacks. In this paper, attack on a chaos-based random number generator using anticipating synchronization is investigated. The considered time-delay chaotic system produces binary signals, which can directly be used as a source of RNG. Anticipating synchronization is obtained by incorporating other systems appropriately coupled to the original one. Quantification of synchronization is given by the bit error between the streams produced by the original and coupled systems. It is shown that the bit streams generated by the original system can be anticipated by the coupled systems beforehand.
Nonlinear Dynamic Behavior of Functionally Graded Truncated Conical Shell Under Complex Loads
Authors: Yang S. W. , Hao Y. X. , Zhang W. , Li S. B.
Published: February 2015

Nonlinear dynamic behaviors of ceramic-metal graded truncated conical shell subjected to complex loads are investigated. The shell is modeled by first-order shear deformation theory. The nonlinear partial differential governing equation in terms of transverse displacements of the FGM truncated conical shell is derived from the Hamilton's principle. Galerkin's method is then utilized to discretize the partial governing equations to a two-degree-of-freedom nonlinear ordinary differential equation. The temperature-dependent materials properties of the constituents are graded in the radial direction in accordance with a power-law distribution. The aerodynamic pressure can be calculated by using the first-order piston theory. The temperature field is assumed to be a steady-state constant-temperature distribution. Bifurcation diagrams, the maximum Lyapunov exponents, wave forms and phase portraits are obtained by numerical simulation to demonstrate the complex nonlinear dynamics response of the FGM truncated conical shell. The influences of the semi-vertex angle, the material gradient index, in-plane and aerodynamic load on the nonlinear dynamics are studied.
Hidden Attractors and Dynamical Behaviors in an Extended Rikitake System
Authors: Wei Zhouchao , Zhang Wei , Wang Zhen , Yao Minghui
Published: February 2015

In this paper, an extended Rikitake system is studied. Several issues, such as Hopf bifurcation, coexistence of stable equilibria and hidden attractor, and dynamics analysis at infinity are investigated either analytically or numerically. Especially, by a simple linear transformation, the wide range of hidden attractors is noticed, and the Lyapunov exponents diagram is given. The obtained results show that the unstable periodic solution generated by Hopf bifurcation leads to the hidden attractor. The existence of hidden attractors that may render the system's behavior unpredictable not only depends on the value of system parameters but also on the value of initial conditions. The phenomena are important and potentially problematic in engineering applications.
Inverse Optimal Pinning Control for Complex Networks of Chaotic Systems
Authors: Sanchez Edgar N. , Rodriguez David I.
Published: February 2015

In this paper, a control strategy based on the inverse optimal control approach is applied for pinning weighted complex networks with chaotic systems at their nodes; additionally, a cost functional is minimized. This control strategy does not require to have the same coupling strength for all node connections.
New Chaotic Regimes in the Lorenz and Chen Systems
Authors: Sprott J. C.
Published: February 2015

It has recently been shown that the Chen system with c > 0 is identical to the reversed-time Lorenz system with particular negative parameters and that the Chen system with c < 0 is identical to the forward-time Lorenz system with particular negative parameters. This note describes this new regime and shows that it admits chaotic solutions that were previously unexplored in either system.
Bridge numbers for virtual and welded knots
Authors: Boden Hans U. , Gaudreau Anne Isabel
Published: February 2015

Using Gauss diagrams, one can define the virtual bridge number vb (K) and the welded bridge number wb (K), invariants of virtual and welded knots satisfying wb (K) ≤ vb (K). If K is a classical knot, Chernov and Manturov showed that vb (K) = br (K), the bridge number as a classical knot, and we ask whether the same thing is true for welded knots. The welded bridge number is bounded below by the meridional rank of the knot group GK, and we use this to relate this question to a conjecture of Cappell and Shaneson. We show how to use other virtual and welded invariants to further investigate bridge numbers. Among them are Manturov's parity and the reduced virtual knot group ḠK, and we apply these methods to address Questions 6.1–6.3 and 6.5 raised by Hirasawa, Kamada and Kamada in their paper [Bridge presentation of virtual knots, J. Knot Theory Ramifications 20(6) (2011) 881–893].
Gravitational anomalies in the solar system?
Authors: Iorio Lorenzo
Published: February 2015

Mindful of the anomalous perihelion precession of Mercury discovered by Le Verrier in the second half of the nineteenth century and its successful explanation by Einstein with his General Theory of Relativity in the early years of the twentieth century, discrepancies among observed effects in our Solar system and their theoretical predictions on the basis of the currently accepted laws of gravitation applied to known matter-energy distributions have the potential of paving the way for remarkable advances in fundamental physics. This is particularly important now more than ever, given that most of the universe seems to be made of unknown substances dubbed Dark Matter and Dark Energy. Should this not be directly the case, Solar system's anomalies could anyhow lead to advancements in either cumulative science, as shown to us by the discovery of Neptune in the first half of the nineteenth century, and technology itself. Moreover, investigations in one of such directions can serendipitously enrich the other one as well. The current status of some alleged gravitational anomalies in the Solar system is critically reviewed. They are: (a) Possible anomalous advances of planetary perihelia. (b) Unexplained orbital residuals of a recently discovered moon of Uranus (Mab). (c) The lingering unexplained secular increase of the eccentricity of the orbit of the Moon. (d) The so-called Faint Young Sun Paradox. (e) The secular decrease of the mass parameter of the Sun. (f) The Flyby Anomaly. (g) The Pioneer Anomaly. (h) The anomalous secular increase of the astronomical unit.
Cosmic polarization rotation: An astrophysical test of fundamental physics
Authors: di Serego Alighieri Sperello
Published: February 2015

Possible violations of fundamental physical principles, e.g. the Einstein equivalence principle on which all metric theories of gravity are based, including general relativity (GR), would lead to a rotation of the plane of polarization for linearly polarized radiation traveling over cosmological distances, the so-called cosmic polarization rotation (CPR). We review here the astrophysical tests which have been carried out so far to check if CPR exists. These are using the radio and ultraviolet polarization of radio galaxies and the polarization of the cosmic microwave background (both E-mode and B-mode). These tests so far have been negative, leading to upper limits of the order of one degree on any CPR angle, thereby increasing our confidence in those physical principles, including GR. We also discuss future prospects in detecting CPR or improving the constraints on it.
SATURATION DEPENDENCE OF TRANSPORT IN POROUS MEDIA PREDICTED BY PERCOLATION AND EFFECTIVE MEDIUM THEORIES
Authors: GHANBARIAN BEHZAD , HUNT ALLEN G. , SKINNER THOMAS E. , EWING ROBERT P.
Published: February 2015

Accurate prediction of the saturation dependence of different modes of transport in porous media, such as those due to conductivity, air permeability, and diffusion, is of broad interest in engineering and natural resources management. Most current predictions use a "bundle of capillary tubes" concept, which, despite its widespread use, is a severely distorted idealization of natural porous media. In contrast, percolation theory provides a reliable and powerful means to model interconnectivity of disordered networks and porous materials. In this study, we invoke scaling concepts from percolation theory and effective medium theory to predict the saturation dependence of modes of transport — hydraulic and electrical conductivity, air permeability, and gas diffusion — in two disturbed soils. Universal scaling from percolation theory predicts the saturation dependence of air permeability and gas diffusion accurately, even when the percolation threshold for airflow is estimated from the porosity. We also find that the non-universal scaling obtained from the critical path analysis (CPA) of percolation theory can make excellent predictions of hydraulic and electrical conductivity under partially saturated conditions.
FRACTAL ASPECTS OF MISCIBLE DISPLACEMENT IN ROUGH FRACTURES: AN EXPERIMENTAL APPROACH
Authors: KORFANTA M. , BABADAGLI T. , DEVELI K.
Published: February 2015

Experiments were performed to study the effect of fracture surface roughness on fluid distribution during miscible displacement. The transparent replicas of single fractures obtained from seven different rocks were prepared and the surface roughness of each sample was described by fractal dimensions using the variogram, power spectral, and triangular prism (TP) techniques. Then, the effect of flow rate and viscosity on the geometry of the displacement front during miscible radial injection was investigated experimentally. The fractal dimensions of the fronts were obtained using box counting fractal analysis at different time lapses. The fractal values of invasion front varied from lithology to lithology, due to different surface roughnesses controlled by the lithology of the rocks. Although fluctuations of fractal values were observed during the growth of the front, fractal dimensions typically yielded an increasing trend. Fractal dimension became more stable with increasing flow rate and developed modestly with increasing viscosity. Finally, relationships between the fractal dimensions of displacement fronts and fracture surfaces were quantitatively analyzed and correlated in order to improve the prediction of fluid distribution within a single fracture during miscible displacement. Overall, correlations were observed between the surface characteristics and front fractal dimension values with some exceptions. In summary, to determine the probable distribution of miscible fluid and development of the front, all parameters except power spectral density (PSD) fractal dimension can be applied in the case of high viscosity ratios. In the case of low injection rates, TP could be applicable. No fractal behavior was present at extreme injection and low viscosity ratios, thus no correlation can be determined for the miscible displacement.
BI-PHASE BOX COUNTING: AN IMPROVED METHOD FOR FRACTAL ANALYSIS OF BINARY IMAGES
Authors: PERFECT E. , DONNELLY B.
Published: February 2015

Many natural systems are irregular and/or fragmented, and have been interpreted to be fractal. An important parameter needed for modeling such systems is the fractal dimension, D. This parameter is often estimated from binary images using the box-counting method. However, it is not always apparent which fractal model is the most appropriate. This has led some researchers to report different D values for different phases of an analyzed image, which is mathematically untenable. This paper introduces a new method for discriminating between mass fractal, pore fractal, and Euclidean scaling in images that display apparent two-phase fractal behavior when analyzed using the traditional method. The new method, coined "bi-phase box counting", involves box-counting the selected phase and its complement, fitting both datasets conjointly to fractal and/or Euclidean scaling relations, and examining the errors from the resulting regression analyses. Use of the proposed technique was demonstrated on binary images of deterministic and stochastic fractals with known D values. Traditional box counting was unable to differentiate between the fractal and Euclidean phases in these images. In contrast, bi-phase box counting unmistakably identified the fractal phase and correctly estimated its D value. The new method was also applied to three binary images of soil thin sections. The results indicated that two of the soils were pore-fractals, while the other was a mass fractal. This outcome contrasted with the traditional box counting method which suggested that all three soils were mass fractals. Reclassification has important implications for modeling soil structure since different fractal models have different scaling relations. Overall, bi-phase box counting represents an improvement over the traditional method. It can identify the fractal phase and it provides statistical justification for this choice.
NATURAL CORROSION INHIBITORS FOR STEEL REINFORCEMENT IN CONCRETE — A REVIEW
Authors: RAJA PANDIAN BOTHI , GHOREISHIAMIRI SEYEDMOJTABA , ISMAIL MOHAMMAD
Published: February 2015

Reinforced concrete is one of the widely used construction materials for bridges, buildings, platforms and tunnels. Though reinforced concrete is capable of withstanding a large range of severe environments including marine, industrial and alpine conditions, there are still a large number of failures in concrete structures for many reasons. Either carbonation or chloride attack is the main culprit which is due to depassivation of reinforced steel and subsequently leads to rapid steel corrosion. Among many corrosion prevention measures, application of corrosion inhibitors play a vital role in metal protection. Numerous range of corrosion inhibitors were reported for concrete protection that were also used commercially in industries. This review summarizes the application of natural products as corrosion inhibitors for concrete protection and also scrutinizes various factors influencing its applicability.
An Improved AM–FM-Based Approach for Reconstructing Fingerprints from Minutiae
Authors: Li Shuiwang , Zhao Qijun , Fei Xiangdong
Published: February 2015

Reconstructing fingerprint images from a given set of minutiae is an important issue in analyzing the masquerade attack of automated fingerprint recognition systems (AFRSs) and in generating large scale databases of synthetic fingerprint images for the performance evaluation of AFRSs. Existing fingerprint reconstruction methods either cannot generate visually plausible or realistic fingerprint images, or suffer from the occurrence of false minutiae in the reconstructed fingerprint images. In this paper, we analyze the underlying reason of false minutiae generated by state-of-the-art amplitude modulation–frequency modulation (AM–FM)-based methods. Furthermore, we propose an improved approach by devising a better way to cope with the branch cuts (or discontinuities) in the fingerprint ridge orientation fields, and by introducing an effective scheme to remove false minutiae from the reconstructed fingerprint images. Compared with previous AM–FM based methods, the proposed method gets rid of block effects and successfully reduces the number of false minutiae. Theoretic proofs are provided with respect to the effectiveness of the proposed method for fingerprints with multiple singular points. The proposed method has also been evaluated on public fingerprint databases. The results demonstrate that it is superior to the existing methods in reconstructing realistic fingerprint images with fewer false minutiae.
WAVE PROPAGATION IN A 1D FLUID DYNAMICS MODEL USING PRESSURE-AREA MEASUREMENTS FROM OVINE ARTERIES
Authors: BATTISTA CHRISTINA , BIA DANIEL , GERMÁN YANINA ZÓCALO , ARMENTANO RICARDO L. , HAIDER MANSOOR A. , OLUFSEN METTE S.
Published: February 2015

This study considers a 1D fluid dynamics arterial network model with 14 vessels developed to assimilate ex vivo 0D temporal data for pressure-area dynamics in individual vessel segments from 11 male Merino sheep. A 0D model was used to estimate vessel wall parameters in a two-parameter elastic model and a four-parameter Kelvin viscoelastic model. This was done using nonlinear optimization minimizing the least squares error between model predictions and measured cross-sectional areas. Subsequently, estimated values for elastic stiffness and unstressed area were related to construct a nonlinear relationship. This relation was used in the network model. A 1D single vessel model of the aorta was then developed and used to estimate the inflow profile and parameters for total resistance and compliance for the downstream network and to demonstrate effects of incorporating viscoelasticity in the arterial wall. Lastly, the extent to which vessel wall parameters estimated from ex vivo data can be used to realistically simulate pressure and area in a vessel network was evaluated. Elastic wall parameters in the network simulations were found to yield pressure-area relationships across all vessel locations and sheep that were in ranges comparable to those in the ex vivo data.
Water molecules response to an external GHz electric field in KcsA potassium channel: A molecular modeling approach
Authors: Sajadi M. , Lohrasebi A. , Setayandeh S. S. , Rafii-Tabar H.
Published: February 2015

KcsA potassium channel is a membrane protein that allows the passage of potassium ions and water molecules across the cellular membrane. Using molecular dynamics (MD) simulation method, the effect of an applied GHz oscillating electric field of strength 0.004 V/nm on the dynamics of K + and water molecules in a KcsA channel was modeled. It was found that the application of GHz range electric field caused a change in the potential energy profile of the water molecules in the filter sites, causing an increase in the delay time of the water molecules in these sites. Therefore, exposing the channel to the GHz fields can perturb the dynamics of the water molecules in the filter, and consequently, the channel operation may be disturbed. Furthermore, the results show that the applied field has no major effects on the dipole orientation of water molecules in the channel.
The Dynamics Between Forward Citations and Price of Singleton Patents
Authors: Nair Shyam Sreekumaran , Mathew Mary
Published: February 2015

In recent years, business practitioners are seen valuing patents on the basis of the market price that the patent can attract. Researchers have also looked into various patent latent variables and firm variables that influence the price of a patent. Forward citations of a patent are shown to play a role in determining price. Using patent auction price data (of Ocean Tomo now ICAP patent brokerage), we delve deeper into the role of forward citations. The successfully sold 167 singleton patents form the sample of our study. We found that, it is mainly the right tail of the citation distribution that explains the high prices of the patents falling on the right tail of the price distribution. There is consistency in the literature on the positive correlation between patent prices and forward citations. In this paper, we go deeper to understand this linear relationship through case studies. Case studies of patents with high and low citations are described in this paper to understand why some patents attracted high prices. We look into the role of additional patent latent variables like age, technology discipline, class and breadth of the patent in influencing citations that a patent receives.
Capsule-Like Fe3O4 Nanoparticles and Triangle Fe3O4 Nanoplates: Facile Synthesis, Magnetic Properties and Catalytic Performance
Authors: Zeng T. , Bai Y. , Li H. , Yao W. F.
Published: February 2015

In this work, Fe 3 O 4 with nanosized triangle plates and capsule-like nanoparticles were prepared by solvothermal approach ( Fe 3 O 4- S ) and hydrothermal approach ( Fe 3 O 4- H ), respectively and their catalytic performance as a heterogeneous Fenton-like catalyst are investigated. Excellent ferromagnetic properties are obtained in both Fe 3 O 4- S nanoplates and Fe 3 O 4- H nanoparticles. The Fe 3 O 4- S nanoplates exhibited better catalytic performance than Fe 3 O 4- H nanoparticles in the degradation of Rhodamine B ( RhB ) with hydrogen peroxide. The relatively high catalytic activity of Fe 3 O 4- S can be ascribed to its high specific surface area and high degree of crystallinity. Fe 3 O 4- S nanoplates also exhibit good catalytic stability and reusability and do not generate significant loss of catalytic activity after four cycles of degradation.
ANALYSIS OF MARKET VOLATILITY VIA A DYNAMICALLY PURIFIED OPTION PRICE PROCESS
Authors: LUONG CHUONG , DOKUCHAEV NIKOLAI
Published: February 2015

The paper studies methods of dynamic estimation of volatility for financial time series. We suggest to estimate the volatility as the implied volatility inferred from some artificial "dynamically purified" price process that in theory allows to eliminate the impact of the stock price movements. The complete elimination would be possible if the option prices were available for continuous sets of strike prices and expiration times. In practice, we have to use only finite sets of available prices. We discuss the construction of this process from the available option prices using different methods. In order to overcome the incompleteness of the available option prices, we suggests several interpolation approaches, including the first order Taylor series extrapolation and quadratic interpolation. We examine the potential of the implied volatility derived from this proposed process for forecasting of the future volatility, in comparison with the traditional implied volatility process such as the volatility index VIX.
Caffeine inhibits glucose transport by binding at the GLUT1 nucleotide-binding site
Authors: Sage Jay M. , Cura Anthony J. , Lloyd Kenneth P. , Carruthers Anthony
Published: February 2015

Glucose transporter 1 (GLUT1) is the primary glucose transport protein of the cardiovascular system and astroglia. A recent study proposes that caffeine uncompetitive inhibition of GLUT1 results from interactions at an exofacial GLUT1 site. Intracellular ATP is also an uncompetitive GLUT1 inhibitor and shares structural similarities with caffeine, suggesting that caffeine acts at the previously characterized endofacial GLUT1 nucleotide-binding site. We tested this by confirming that caffeine uncompetitively inhibits GLUT1-mediated 3- O-methylglucose uptake in human erythrocytes [ Vmax and Km for transport are reduced fourfold; Ki(app) = 3.5 mM caffeine]. ATP and AMP antagonize caffeine inhibition of 3- O-methylglucose uptake in erythrocyte ghosts by increasing Ki(app) for caffeine inhibition of transport from 0.9 ± 0.3 mM in the absence of intracellular nucleotides to 2.6 ± 0.6 and 2.4 ± 0.5 mM in the presence of 5 mM intracellular ATP or AMP, respectively. Extracellular ATP has no effect on sugar uptake or its inhibition by caffeine. Caffeine and ATP displace the fluorescent ATP derivative, trinitrophenyl-ATP, from the GLUT1 nucleotide-binding site, but d-glucose and the transport inhibitor cytochalasin B do not. Caffeine, but not ATP, inhibits cytochalasin B binding to GLUT1. Like ATP, caffeine renders the GLUT1 carboxy-terminus less accessible to peptide-directed antibodies, but cytochalasin B and d-glucose do not. These results suggest that the caffeine-binding site bridges two nonoverlapping GLUT1 endofacial sites—the regulatory, nucleotide-binding site and the cytochalasin B-binding site. Caffeine binding to GLUT1 mimics the action of ATP but not cytochalasin B on sugar transport. Molecular docking studies support this hypothesis.
Regulation of basal promoter activity of the human thiamine pyrophosphate transporter SLC44A4 in human intestinal epithelial cells
Authors: Nabokina Svetlana M. , Ramos Mel Brendan , Valle Judith E. , Said Hamid M.
Published: February 2015

Microbiota of the large intestine synthesize considerable amount of vitamin B1 in the form of thiamine pyrophosphate (TPP). There is a specific high-affinity regulated carrier-mediated uptake system for TPP in human colonocytes (product of the SLC44A4 gene). The mechanisms of regulation of SLC44A4 gene expression are currently unknown. In this study, we characterized the SLC44A4 minimal promoter region and identified transcription factors important for basal promoter activity in colonic epithelial cells. The 5′-regulatory region of the SLC44A4 gene (1,022 bp) was cloned and showed promoter activity upon transient transfection into human colonic epithelial NCM460 cells. With the use of a series of 5′- and 3′-deletion luciferase reporter constructs, the minimal genomic region that required basal transcription of the SLC44A4 gene expression was mapped between nucleotides −178 and +88 (using the distal transcriptional start site as +1). Mutational analysis performed on putative cis-regulatory elements established the involvement of ETS/ELF3 [E26 transformation-specific sequence (ETS) proteins], cAMP-responsive element (CRE), and SP1/GC-box sequence motifs in basal SLC44A4 promoter activity. By means of EMSA, binding of ELF3 and CRE-binding protein-1 (CREB-1) transcription factors to the SLC44A4 minimal promoter was shown. Contribution of CREB into SLC44A4 promoter activity was confirmed using NCM460 cells overexpressing CREB. We also found high expression of ELF3 and CREB-1 in colonic (NCM460) compared with noncolonic (ARPE19) cells, suggesting their possible contribution to colon-specific pattern of SLC44A4 expression. This study represents the first characterization of the SLC44A4 promoter and reports the importance of both ELF3 and CREB-1 transcription factors in the maintenance of basal promoter activity in colonic epithelial cells.
Enhanced fatty acid oxidation in adipocytes and macrophages reduces lipid-induced triglyceride accumulation and inflammation
Authors: Malandrino Maria Ida , Fucho Raquel , Weber Minéia , Calderon-Dominguez María , Mir Joan Francesc , Valcarcel Lorea , Escoté Xavier , Gómez-Serrano María , Peral Belén , Salvadó Laia , Fernández-Veledo Sonia , Casals Núria , Vázquez-Carrera Manuel , Villarroya Francesc , Vendrell Joan J , Serra Dolors , Herrero Laura
Published: February 2015

Lipid overload in obesity and type 2 diabetes is associated with adipocyte dysfunction, inflammation, macrophage infiltration, and decreased fatty acid oxidation (FAO). Here, we report that the expression of carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme in mitochondrial FAO, is higher in human adipose tissue macrophages than in adipocytes and that it is differentially expressed in visceral vs. subcutaneous adipose tissue in both an obese and a type 2 diabetes cohort. These observations led us to further investigate the potential role of CPT1A in adipocytes and macrophages. We expressed CPT1AM, a permanently active mutant form of CPT1A, in 3T3-L1 CARΔ1 adipocytes and RAW 264.7 macrophages through adenoviral infection. Enhanced FAO in palmitate-incubated adipocytes and macrophages reduced triglyceride content and inflammation, improved insulin sensitivity in adipocytes, and reduced endoplasmic reticulum stress and ROS damage in macrophages. We conclude that increasing FAO in adipocytes and macrophages improves palmitate-induced derangements. This indicates that enhancing FAO in metabolically relevant cells such as adipocytes and macrophages may be a promising strategy for the treatment of chronic inflammatory pathologies such as obesity and type 2 diabetes.
Skeletal muscle dysfunction is associated with derangements in mitochondrial bioenergetics (but not UCP3) in a rodent model of sepsis
Authors: Zolfaghari Parjam S. , Carré Jane E. , Parker Nadeene , Curtin Nancy A. , Duchen Michael R. , Singer Mervyn
Published: February 2015

Muscle dysfunction is a common feature of severe sepsis and multiorgan failure. Recent evidence implicates bioenergetic dysfunction and oxidative damage as important underlying pathophysiological mechanisms. Increased abundance of uncoupling protein-3 (UCP3) in sepsis suggests increased mitochondrial proton leak, which may reduce mitochondrial coupling efficiency but limit reactive oxygen species (ROS) production. Using a murine model, we examined metabolic, cardiovascular, and skeletal muscle contractile changes following induction of peritoneal sepsis in wild-type and Ucp3−/−mice. Mitochondrial membrane potential (Δψm) was measured using two-photon microscopy in living diaphragm, and contractile function was measured in diaphragm muscle strips. The kinetic relationship between membrane potential and oxygen consumption was determined using a modular kinetic approach in isolated mitochondria. Sepsis was associated with significant whole body metabolic suppression, hypothermia, and cardiovascular dysfunction. Maximal force generation was reduced and fatigue accelerated in ex vivo diaphragm muscle strips from septic mice. Δψmwas lower in the isolated diaphragm from septic mice despite normal substrate oxidation kinetics and proton leak in skeletal muscle mitochondria. Even though wild-type mice exhibited an absolute 26 ± 6% higher UCP3 protein abundance at 24 h, no differences were seen in whole animal or diaphragm physiology, nor in survival rates, between wild-type and Ucp3−/−mice. In conclusion, this murine sepsis model shows a hypometabolic phenotype with evidence of significant cardiovascular and muscle dysfunction. This was associated with lower Δψmand alterations in mitochondrial ATP turnover and the phosphorylation pathway. However, UCP3 does not play an important functional role, despite its upregulation.
Peripheral insulin resistance in obese girls with hyperandrogenism is related to oxidative phosphorylation and elevated serum free fatty acids
Authors: Cree-Green Melanie , Newcomer Bradley R. , Coe Gregory , Newnes Lindsey , Baumgartner Amy , Brown Mark S. , Pyle Laura , Reusch Jane E. , Nadeau Kristen J.
Published: February 2015

Hyperandrogenic syndrome (HAS) is associated with insulin resistance (IR) and type 2 diabetes. Muscle IR in type 2 diabetes is linked with defects in mitochondrial oxidative capacity. In vivo muscle mitochondrial function has not been studied in HAS, especially in youth, who are early in the disease process. Our goal was to measure muscle mitochondrial oxidative function and peripheral IR in obese youth with HAS. Obese girls without HAS [ n = 22, age 15(13,17) yr, BMI Z-score 2.05 ± 0.37] and with HAS [ n = 35, age 15(14,16) yr, BMI Z-score 2.18 ± 0.30] were enrolled. Mitochondrial function was assessed with31phosphorus MR spectroscopy before, during, and after near-maximal isometric calf exercise, and peripheral IR was assessed with an 80 mU·m−2·min−1hyperinsulinemic euglycemic clamp. Girls with HAS had higher androgens [free androgen index 7.9(6.6,15.5) vs. 3.5(3.0,4.0), P < 0.01] and more IR [glucose infusion rate 9.4(7.0, 12,2) vs. 14.5(13.2,15.8) mg·kg lean−1·min−1, P < 0.01]. HAS girls also had increased markers of inflammation including CRP, platelets, and white blood cell count and higher serum free fatty acids during hyperinsulinemia. Mitochondrial oxidative phosphorylation was lower in HAS [0.11(0.06,0.19) vs. 0.18(0.12,0.23) mmol/s, P < 0.05], although other spectroscopy markers of mitochondrial function were similar between groups. In multivariate analysis of the entire cohort, IR related to androgens, oxidative phosphorylation, and free fatty acid concentrations during hyperinsulinemia. These relationships were present in just the HAS cohort as well. Obese girls with HAS have significant peripheral IR, which is related to elevated androgens and free fatty acids and decreased mitochondrial oxidative phosphorylation. These may provide future options as targets for therapeutic intervention.
Optical reconstruction of murine colorectal mucosa at cellular resolution
Authors: Liu Cambrian Y. , Dubé Philip E. , Girish Nandini , Reddy Ajay T. , Polk D. Brent
Published: February 2015

The mucosal layer of the colon is a unique and dynamic site where host cells interface with one another and the microbiome, with major implications for physiology and disease. However, the cellular mechanisms mediating colonic regeneration, inflammation, dysplasia, and dysbiosis remain undercharacterized, partly because the use of thin tissue sections in many studies removes important volumetric context. To address these challenges in visualization, we have developed the deep mucosal imaging (DMI) method to reconstruct continuous extended volumes of mouse colorectal mucosa at cellular resolution. Use of ScaleA2 and SeeDB clearing agents enabled full visualization of the colonic crypt, the fundamental unit of adult colon. Confocal imaging of large colorectal expanses revealed epithelial structures involved in repair, inflammation, tumorigenesis, and stem cell function, in fluorescent protein-labeled, immunostained, paraffin-embedded, or human biopsy samples. We provide freely available software to reconstruct and explore on computers with standard memory allocations the large DMI datasets containing in toto representations of distal colonic mucosal volume. Extended-volume imaging of colonic mucosa through the novel, extensible, and readily adopted DMI approach will expedite mechanistic investigations of intestinal physiology and pathophysiology at intracrypt to multicrypt length scales.
CXCL8 histone H3 acetylation is dysfunctional in airway smooth muscle in asthma: regulation by BET
Authors: Clifford Rachel L. , Patel Jamie K. , John Alison E. , Tatler Amanda L. , Mazengarb Lisa , Brightling Christopher E. , Knox Alan J.
Published: February 2015

Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation.
Cold-acclimation leads to differential regulation of the steelhead trout (Oncorhynchus mykiss) coronary microcirculation
Authors: Costa Isabel A. S. F. , Hein Travis W. , Gamperl A. K.
Published: February 2015

The regulation of vascular resistance in fishes has largely been studied using isolated large conductance vessels, yet changes in tissue perfusion/vascular resistance are primarily mediated by the dilation/constriction of small arterioles. Thus we adapted mammalian isolated microvessel techniques for use in fish and examined how several agents affected the tone/resistance of isolated coronary arterioles (<150 μm ID) from steelhead trout ( Oncorhynchus mykiss) acclimated to 1, 5, and 10°C. At 10°C, the vessels showed a concentration-dependent dilation to adenosine (ADE; 61 ± 8%), sodium nitroprusside (SNP; 35 ± 10%), and serotonin (SER; 27 ± 2%) (all values maximum responses). A biphasic response (mild contraction then dilation) was observed in vessels exposed to increasing concentrations of epinephrine (EPI; 34 ± 9% dilation) and norepinephrine (NE; 32 ± 7% dilation), whereas the effect was less pronounced with bradykinin (BK; 12.5 ± 3.5% constriction vs. 6 ± 6% dilation). Finally, a mild constriction was observed after exposure to acetylcholine (ACh; 6.5 ± 1.4%), while endothelin (ET)-1 caused a strong dose-dependent increase in tone (79 ± 5% constriction). Acclimation temperature had varying effects on the responsiveness of vessels. The dilations induced by EPI, ADE, SER, and SNP were reduced/eliminated at 5°C and/or 1°C as compared with 10°C. In contrast, acclimation to 5 and 1°C increased the maximum constriction induced by ACh and the sensitivity of vessels to ET-1 (but not the maximum response) at 1°C was greater. Acclimation temperature had no effect on the response to NE, and responsiveness to BK was variable.
Midline section of the medulla abolishes inspiratory activity and desynchronizes pre-inspiratory neuron rhythm on both sides of the medulla in newborn rats
Authors: Onimaru Hiroshi , Tsuzawa Kayo , Nakazono Yoshimi , Janczewski Wiktor A.
Published: February 2015

Each half of the medulla contains respiratory neurons that constitute two generators that control respiratory rhythm. One generator consists of the inspiratory neurons in the pre-Bötzinger complex (preBötC); the other, the pre-inspiratory (Pre-I) neurons in the parafacial respiratory group (pFRG), rostral to the preBötC. We investigated the contribution of the commissural fibers, connecting the respiratory rhythm generators located on the opposite side of the medulla to the generation of respiratory activity in brain stem-spinal cord preparation from 0- to 1-day-old rats. Pre-I neuron activity and the facial nerve and/or first lumbar (L1) root activity were recorded as indicators of the pFRG-driven rhythm. Fourth cervical ventral root (C4) root and/or hypoglossal (XII) nerve activity were recorded as indicators of preBötC-driven inspiratory activity. We found that a midline section that interrupted crossed fibers rostral to the obex irreversibly eliminated C4 and XII root activity, whereas the Pre-I neurons, facial nerve, and L1 roots remained rhythmically active. The facial and contralateral L1 nerve activities were synchronous, whereas right and left facial (and right and left L1) nerves lost synchrony. Optical recordings demonstrated that pFRG-driven burst activity was preserved after a midline section, whereas the preBötC neurons were no longer rhythmic. We conclude that in newborn rats, crossed excitatory interactions (via commissural fibers) are necessary for the generation of inspiratory bursts but not for the generation of rhythmic Pre-I neuron activity.