bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcitriol, calcidiol, parathyroid hormone, and fibroblast growth factor‐23 interactions in chronic kidney disease
Authors: de Brito Galvao Joao F. , Nagode Larry A. , Schenck Patricia A. , Chew Dennis J.
Published: April 2013

Objective

To review the inter‐relationships between calcium, phosphorus, parathyroid hormone (PTH), parent and activated vitaminDmetabolites (vitaminD, 25(OH)‐vitaminD, 1,25(OH)2‐vitaminD, 24,25(OH)2‐vitamin D), and fibroblast growth factor‐23 (FGF‐23) during chronic kidney disease (CKD) in dogs and cats.

Data Sources

Human and veterinary literature.

Human Data Synthesis

Beneficial effects of calcitriol treatment duringCKDhave traditionally been attributed to regulation ofPTHbut new perspectives emphasize direct renoprotective actions independent ofPTHand calcium. It is now apparent that calcitriol exerts an important effect on renal tubular reclamation of filtered 25(OH)‐vitaminD, which may be important in maintaining adequate circulating 25(OH)‐vitaminD. This in turn may be vital for important pleiotropic actions in peripheral tissues through autocrine/paracrine mechanisms that impact the health of those local tissues.

Veterinary Data Synthesis

Limited information is available reporting the benefit of calcitriol treatment in dogs and cats withCKD.

Conclusions

A survival benefit has been shown for dogs withCKDtreated with calcitriol compared to placebo. The concentrations of circulating 25(OH)‐vitaminDhave recently been shown to be low in people and dogs withCKDand are related to survival in people withCKD. Combination therapy for people withCKDusing both parental and activated vitaminDcompounds is common in human nephrology and there is a developing emphasis using combination treatment with activated vitaminDand renin‐angiotensin‐aldosterone‐system (RAAS) inhibitors.
Energy Dissipation Effect in the One-Dimensional Limit of the Energy Equation in Turbulent Compressible Flow
Authors: Ytrehus Tor , Helgaker Jan Fredrik
Published: April 2013

The transportation of natural gas through high pressure transmission pipelines has been modeled by numerically solving the conservation equations for mass, momentum, and energy for one-dimensional compressible viscous heat conducting flow. Since the one-dimensional version is a result of averages over the pipe cross-section and the flow is normally turbulent, the order of averaging in space and time is an issue; in particular, for the dissipation term. The Reynolds decomposition and time averaging should be performed first, followed by the contraction to the one-dimensional version by the cross-sectional averaging. The result is a correction factor, which is close to unity, on the usual expression of the dissipation term in the energy equation. This factor will, to some extent, affect the temperature distribution along the pipeline. For low Reynolds numbers (Re≃104) it reduces the dissipation by as much as 7%, irrespective of roughness. For high Reynolds numbers (Re ≥ 107) and roughness in the high range of the micron decade, the dissipation is increased by 10%. If the pipeline is also thermally isolated such that the flow can be considered adiabatic, the effect of turbulent dissipation gains further importance.
Car Stopping Distance on a Tabletop
Authors: Haugland Ole Anton
Published: April 2013

Stopping distances in car braking can be an intriguing topic in physics teaching. It illustrates some basic principles of physics, and sheds valuable light on students' attitude towards aggressive driving. Due to safety considerations, it can be difficult to make experiments with actual car braking.
Pressure Beneath the Surface of a Fluid: Measuring the Correct Depth
Authors: McCall Richard P.
Published: April 2013

Systematic errors can cause measurements to deviate from the actual value of the quantity being measured. Faulty equipment (such as a meterstick that is not marked correctly), inaccurate calibration of measuring devices (such as a scale to measure mass that has not been properly zeroed), and improper use of equipment by the experimenter (such as misinterpreting the range of a voltmeter) are all examples of systematic errors. Some systematic errors are constant, whereas others are proportional to some quantity that changes in the experiment (whether that quantity is being measured or not). Systematic errors in a variety of laboratory exercises have been described in articles in The Physics Teacher.1–8
The Inverse-Square Law with Data Loggers
Authors: Bates Alan
Published: April 2013

The inverse-square law for the intensity of light received at a distance from a light source has been verified using various experimental techniques.1 Typical measurements involve a manual variation of the distance between a light source and a light sensor, usually by sliding the sensor or source along a bench, measuring the source-sensor distance and the received light intensity at each value of distance. In this experiment, motion and light sensors,2 with data-logging software, are used to simultaneously measure the light source-sensor distance and the light intensity falling on the light sensor.
Summer Session: A Time for Innovation
Authors: Mola Monty
Published: April 2013

Summer is almost here (at least for those of us who teach semesters). Many of us are taking a well-deserved break to spend time with our families, conduct research, travel, and myriad other activities. Some of us, however, will be teaching summer school. For those of us lucky enough to be teaching this summer, we have one suggestion: Be bold! Summer is the ideal time to try something new with your teaching. We have known for some time that alternative pedagogies and engaging teaching strategies can be more effective than traditional lectures as student learning environments.1 However, even with headlines in The Washington Post proclaiming that the lecture is dead,2 inroads of physics education research-based curricula have been slow to diffuse into the classrooms for the greater population of college physics instructors.3 Many instructors of traditional physics courses see the use of research-based instructional strategies (RBIS) as desirable but risky and time consuming.3 Assuming a traditional physics course structure, both the where and the when each component takes place can also limit the types of engaging pedagogies used.4
A Simple Inexpensive Procedure for Illustrating Some Principles of Tomography
Authors: Darvey Ivan G.
Published: April 2013

The experiment proposed here illustrates some concepts of tomography via a qualitative determination of the relative concentration of various dilutions of food dye without a priori knowledge of the concentration of each dye mixture. This is performed in a manner analogous to computed tomography (CT) scans. In order to determine the relative concentrations of dye in containers, observations are made of the transmitted light through various combinations of the containers.
Acoustic measurements of bouncing balls and the determination of gravitational acceleration
Authors: Schwarz Oliver , Vogt Patrik , Kuhn Jochen
Published: April 2013

Interesting experiments can be performed and fundamental physical relationships can be explored with so-called Super Balls or bouncy balls. An example is the determination of gravity g in an experiment. The basic idea behind this was described by Pape1 and Sprockhoff2: The initial and final heights and the complete duration of all the bounces are measured for a certain number of bounces by the ball. On the basis of this data, the acceleration of gravity can be approximately calculated if air drag on the ball is neglected. However, in practice, it becomes clear that measuring the height of the last bounce in the process is problematic. The person performing the experiment either has to make a good estimation of its height or film the bounce in front of a measuring stick. The method is based on the important assumption that each of the individual bounces of the ball loses the same percentage of mechanical energy; the coefficient of restitution k therefore remains the same.
Optimization of the array mirror for time reversal techniques used in a half-space environment
Authors: Harker Blaine M. , Anderson Brian E.
Published: April 2013

Time reversal (TR) utilizes an array of transducers, a time reversal mirror (TRM), to locate sources. Here TR is applied to simple sources using steady-state waveforms in a numerical, point source model in a half-space environment. It is found that TR can effectively localize a simple source broadcasting a continuous wave, depending on the angular spacing. Furthermore, the angular spacing and the aperture of the TRM are the most important parameters when creating a setup of receivers for imaging a source. This work optimizes a TRM when the source's location is known within a region of certainty.
Enantiospecific synthesis of the diacid side-chain of deoxyharringtonine and homodeoxyharringtonine
Authors: Sun Moran , Xie Yangla , Gu Jincan , Yang Hua
Published: April 2013

The enantiospecific synthesis of the diacid side-chain of deoxyharringtonine (2) and homodeoxyharringtonine (3) was accomplished from (L)-N-Boc-α-amino alcohol 10 in high yield. A key feature of the synthesis is the construction of the chiral tertiary alcohol by a three-step sequence (i.e., Wittig reaction, Meisenheimer rearrangement, and catalytic hydrogenation).
Changes in water chemistry associated with beaver-impounded coastal marshes of eastern Georgian Bay
Authors: Fracz Amanda , Chow-Fraser Patricia
Published: April 2013

Coastal marshes of eastern Georgian Bay contain unique water chemistry that reflects mixing between the relatively ion-rich waters of Georgian Bay and the relatively ion-poor water draining the Canadian Shield landscape. These unique chemical characteristics may be dramatically altered when wetlands become hydrologically disconnected from Georgian Bay through beaver activity. We sampled 35 coastal marshes in Georgian Bay, 17 of which had beaver impoundments built at the outlet of the coastal wetland. Impounded marshes had significantly higher total phosphorus (30.2 versus 15.3 μg·L−1, p = 0.0015), soluble reactive phosphorus, (13.33 versus 3.7 μg·L−1, p ≤ 0.0001), total suspended solids (15.5 versus 2.1 mg·L−1, p ≤ 0.0001), turbidity (5.4 versus 1.6, p = 0.0004), and chlorophyll (6.2 versus 1.9 μg·L−1, p = 0.0004), but significantly lower pH (5.57 versus 6.95, p ≤ 0.0001), nitrates (0.03 versus 0.04 mg·L−1, p = 0.0416), and conductivity (47 versus 134 μS·cm−1, p ≤ 0.0001), indicative of reduced mixing with Georgian Bay. The mosaic of chemical conditions and altered hydrological connectivity associated with beaver impoundments in coastal marshes of Georgian Bay may affect the distribution of other wetland biota, and further studies should be conducted to ascertain these impacts.
Quantum corrections to thermodynamic quantities because of spin fields and the generalized uncertainty principle
Authors: Li Guqiang , Mo Jiexiong
Published: April 2013

The entropy density, energy density, pressure, and equation of state for the perfect relativistic gas with arbitrary spin s ≤ 2 around Schwarzschild – anti-de Sitter black holes with a global monopole are investigated by using the modified state density from the generalized uncertainty principle. It is shown that all the thermodynamic quantities do not take the same forms as those in flat space–time and include terms depending on the spin and the gravity correction factor. The existence of these additional terms is closely related to conformal anomalies in curved space–time and the not-purely thermal radiation of black hole.
Spin wave theory of spin-1/2 XY model with ring exchange on a triangular lattice
Authors: Owerre Solomon A.
Published: April 2013

We present the linear spin wave theory calculation of the superfluid phase of a hard-core boson J-K model with nearest neighbour exchange J and four-particle ring-exchange K at half filling on the triangular lattice, as well as the phase diagrams of the system at zero and finite temperatures. A similar analysis has been done on a square lattice (Schaffer et al. Phys. Rev. B, 80, 014503 (2009)). We find similar behaviour to that of a square lattice but with different spin wave values of the thermodynamic quantities. We also find that the pure J model (XY model), which has a well-known uniform superfluid phase with an ordered parameter [Formula: see text] at zero temperature is quickly destroyed by the inclusion of negative-K ring-exchange interactions, favouring a state with a (4π/3, 0) ordering wavevector. We further study the behaviour of the finite-temperature Kosterlitz–Thouless phase transition (TKT) in the uniform superfluid phase, by forcing the universal quantum jump condition on the finite-temperature spin wave superfluid density. We find that for K < 0, the phase boundary monotonically decreases to T = 0 at K/J = −4/3, where a phase transition is expected and TKT decreases rapidly, while for positive K, TKT reaches a maximum at some K ≠ 0. It has been shown on a square lattice using quantum Monte Carlo (QMC) simulations that for small K > 0 away from the XY point, the zero-temperature spin stiffness value of the XY model is decreased (Melko and Sandvik. Ann. Phys. 321, 1651 (2006)). Our result seems to agree with this trend found in QMC simulations for two-dimensional systems.
Behavioural and network plasticity following conditioning of the aerial respiratory response of a pulmonate mollusc
Authors: Spencer G.E. , Rothwell C.M.
Published: April 2013

Most molluscs perform respiration using gills, but the pulmonate molluscs have developed a primitive lung with which they perform pulmonary respiration. The flow of air into this lung occurs through an opening called the pneumostome, and pulmonate molluscs travel to the surface of the water to obtain oxygen from the surrounding atmosphere. The aerial respiratory behaviour of the pulmonate mollusc, the great pond snail (Lymnaea stagnalis (L., 1758)), has been well studied, and a three-neuron central pattern generator (CPG) controlling this rhythmic behaviour has been identified. The aerial respiratory behaviour of L. stagnalis can be operantly conditioned and plasticity within the CPG has been associated with the conditioned response. In this review, we describe both the aerial respiratory behaviour and the underlying neuronal network of this pulmonate mollusc, and then discuss both the behavioural and network plasticity that results from the conditioning of this behaviour.
Plasticity of shell preference and its antipredatory advantages in the hermit crabCalcinuscaliforniensis
Authors: Arce Elsah , Alcaraz Guillermina
Published: April 2013

The preference of the hermit crab Calcinus californiensis Bouvier, 1898 among six shell species and different shell sizes was evaluated in the presence of the swimming crab Arenaeus mexicanus (Gerstaecker, 1856), a natural predator of this species. In a second experiment, the survival benefit of the shell choice made under predation threat was examined by exposing hermit crabs occupying three different shell species (including the most and least preferred shells of two fits) to a free swimming crab predator. The preference for shell species was similar in the absence and presence of the predator threat, although the hermit crabs choose larger shells (loose) when exposed to the predator compared with the ones chosen in its absence. The predatory experiment showed a higher survival chance for the hermit crabs occupying loose shells of the preferred shell species (Cantharus sanguinolentus (Duclos, 1833)). The results of this study show that the hermit crab C. californiensis is able to change their preference for shell size in response to a predation threat and that the change in preference confers survival benefits for hermit crabs. This study is consistent with the assumption that predation is an important selective pressure for intertidal hermit crabs.
A possible breakage of linkage disequilibrium between mitochondrial and chloroplast genomes during Emmer and Dinkel wheat evolution
Authors: Tsujimura Mai , Mori Naoki , Yamagishi Hiroshi , Terachi Toru
Published: April 2013

In wheat (Triticum) and Aegilops, chloroplast and mitochondrial genomes have been studied for over three decades to clarify the phylogenetic relationships among species, and most of the maternal lineages of polyploid species have been clarified. Mitochondrial genomes of Emmer (tetraploid with nuclear genome AABB) and Dinkel (hexaploid with AABBDD) wheat are classified into two different types, VIIa and VIIb, by the presence–absence of the third largest HindIII fragment (named H3) in the mitochondrial DNA. Although the mitochondrial genome in the genera often provides useful information to clarify the phylogenetic relationship among closely related species, the phylogenetic significance of this dimorphism has yet not been clarified. In this study, to facilitate analysis using a large number of accessions, a sequence characterized amplified region (SCAR) marker that distinguishes the type VIIb mitochondrial genome from type VIIa was first developed. Mitochondrial genome type was determined for each of 30 accessions of wild and cultivated Emmer wheat and 25 accessions of Dinkel wheat. The mitochondrial genome type for each accession was compared with the plastogroup that had been determined using chloroplast microsatellite markers. Unexpectedly, the distribution of mitochondrial genome type was not in accordance with that of the plastogroups, suggesting occasional paternal leakage of either the mitochondrial or chloroplast genome during speciation and differentiation of Emmer and Dinkel wheat. An alternative possibility that substoichiometric shifting is involved in the observed dimorphism of the mitochondrial genome is also discussed.
The Determinants of Performance in Alternative Markets for Small and Medium Enterprises: International Evidence
Authors: Wong Alvin Y. T. , Tang Gordon Y. N. , Chan Kam C.
Published: April 2013

Several stock exchanges have launched alternative markets to target small and medium enterprises. In this research, we examine the determinants of the operating and stock return performance of alternative markets. Our results suggest that turnover and stock returns of alternative markets affect each other. Hence, it is imperative to examine the performances of alternative markets in a simultaneous equation system to mitigate the causality among performance variables. In addition, a good anti-director rights environment and a noncommon law origin country contribute to a higher turnover and additional new listings in an alternative market. A common law origin country, all else the same, contributes to higher alternative market stock returns. A high index of economic freedom negatively correlates with the turnover of an alternative market. The accounting standard and the governance structure of an exchange are not related to the operating and stock return performance in alternative markets. This research contributes to stock market development by focusing on alternative markets.
Knowledge Management Success in Clinical Service Environments
Authors: Handzic Meliha , Ozlen Kursad
Published: April 2013

The related literature suggests the need to achieve deeper understanding and explanation of knowledge management (KM) success in healthcare service with respect to the complexity of the decision environment. Therefore, this research aims to examine descriptively KM success in Turkish healthcare organisations. More specifically, the study analyses the characteristics of the clinical context, social and technical aspects of the implemented KM solutions (KMS), clinical staff's KMS adoption and its impact on their knowledge and performance in two different clinical service environments (hospitals). The results reveal some interesting patterns. As expected, the participants who perceived their context as more complex and KMS as more sophisticated tended to adopt it more than others. However, this did not produce more superior knowledge and performance. Several possible explanations were offered for the findings and future research was recommended in order to overcome current limitations.
INNOVATION CAPABILITY AND MARKET PERFORMANCE: THE MODERATING EFFECT OF INDUSTRY DYNAMISM
Authors: ZHANG JING A. , GARRETT-JONES SAM , SZETO RICKY
Published: April 2013

Based on the resource-based view of the firm (RBV) and the resource/capability perspective of innovation, this study explores the independent and complementary effects of two types of innovation capability (namely product development capability and operational capability) on market performance in a sample of 2971 Chinese industrial firms. Product development capability and operational capability have different degrees of firm specificity in terms of the technological complexity of underlying resources. We further explore industry dynamism as an important moderating effect on the relationship between different types of innovation capability and market performance. Our findings suggest that,in the Chinese firms surveyed, both product development and operational capability in innovation positively contribute to market performance. The effect of operational capability is notably stronger than that of product development capability. We also confirm the complementary effect of operational capability with product development capability in enhancing market performance. Our findings further suggest that product development capability tends to have a stronger effect on market performance when the level of industry dynamism is low, while the impact of operational capability on market performance is stronger in industries with a relatively high level of dynamism.
MICRO-SLIP INDUCED DAMPING IN THE CONTACT OF NOMINALLY FLAT SURFACES
Authors: BOUCHAALA NOUSSA , DION JEAN LUC , PEYRET NICOLAS , HADDAR MOHAMED
Published: April 2013

It is well known that the friction between interfaces at bolted joints plays a major role in the damping of assembly structures. Friction can be either induced by macro-slipping or micro-slipping. The aim of this paper is to model and quantify the dissipated energy by micro-sliding down to the scale of roughness between two flat surfaces in order to compute the damping ratio. It was assumed that the coefficient of friction between two materials is constant and that friction is the only source of energy dissipation. An experimental study was conducted to measure static normal load and dynamic tangential load without any coupling between these two main directions. A rheological contact model based on the Extended Greenwood Model with micro-contacts and statistical distributions was developed and studied. Experimental results and simulations are compared in order to assess and discuss the model.
AXIAL CRUSHING OF TRIANGULAR TUBES
Authors: FAN Z. , LU G. , YU T. X. , LIU K.
Published: April 2013

In the present paper, the mechanical behavior of large deformation of a regular equilateral triangular tube under quasi-static axial crushing is reported, which is a polygon with an acute angle and odd number of sides. Based on the results from nonlinear finite element analysis (FEA), a new type of inextensional basic plastic collapse folding element is proposed to describe the plastic progressive collapse. The progressive folding around the stationary horizontal hinges and inclined traveling hinges are involved to develop the new basic folding element. Two types of inextensible deformation modes are discovered, i.e., diamond mode and rotational symmetrical mode. The average crushing load for each mode is predicted from the super-folding element theory, which was proposed from the previous investigation on the axial crushing of square columns. A rigid-plastic material model and a kinematically admissible model are involved in this theory. The results are further validated against experiments. The approximate quasi-static theoretical predictions for the mean crushing loads of triangular tubes provide reasonable agreement with the corresponding experimental results.
ADAPTIVE SUB-LINEAR TIME FOURIER ALGORITHMS
Authors: LAWLOR DAVID , WANG YANG , CHRISTLIEB ANDREW
Published: April 2013

We present a new deterministic algorithm for the sparse Fourier transform problem, in which we seek to identify k ≪ N significant Fourier coefficients from a signal of bandwidth N. Previous deterministic algorithms exhibit quadratic runtime scaling, while our algorithm scales linearly with k in the average case. Underlying our algorithm are a few simple observations relating the Fourier coefficients of time-shifted samples to unshifted samples of the input function. This allows us to detect when aliasing between two or more frequencies has occurred, as well as to determine the value of unaliased frequencies. We show that empirically our algorithm is orders of magnitude faster than competing algorithms.
Economic Efficiency Assessment of Autonomous Wind/Diesel/Hydrogen Systems in Russia
Authors: Marchenko O. V. , Solomin S. V.
Published: April 2013

The economic efficiency of harnessing wind energy in the autonomous power systems of Russia is analyzed. Wind turbines are shown to be competitive for many considered variants (groups of consumers, placement areas, and climatic and meteorological conditions). The authors study the possibility of storing energy in the form of hydrogen in the autonomous wind/diesel/hydrogen power systems that include wind turbines, diesel generator, electrolyzer, hydrogen tank, and fuel cells. The paper presents the zones of economic efficiency of the system (set of parameters that provide its competitiveness) depending on load, fuel price, and long-term average annual wind speed. At low wind speed and low price of fuel, it is reasonable to use only diesel generator to supply power to consumers. When the fuel price and wind speed increase, first it becomes more economical to use a wind-diesel system and then wind turbines with a hydrogen system. In the latter case, according to the optimization results, diesel generator is excluded from the system.
Comparison of Two New Mouse Models of Polygenic Type 2 Diabetes at the Jackson Laboratory, NONcNZO10Lt/J and TALLYHO/JngJ
Authors: Leiter Edward H. , Strobel Marjorie , O'Neill Adam , Schultz David , Schile Andrew , Reifsnyder Peter C.
Published: April 2013

This review compares two novel polygenic mouse models of type 2 diabetes (T2D), TALLYHO/JngJ and NONcNZO10/LtJ, and contrasts both with the well-known C57BLKS/J-Leprdb(db/db) monogenic diabesity model. We posit that the new polygenic models are more representative of the “garden variety” obesity underlying human T2D in terms of their polygenetic rather than monogenic etiology. Moreover, the clinical phenotypes in these new models are less extreme, for example, more moderated development of obesity coupled with less extreme endocrine disturbances. The more progressive development of obesity produces a maturity-onset development of hyperglycemia in contrast to the juvenile-onset diabetes observed in the morbidly obesedb/dbmodel. Unlike the leptin receptor-deficientdb/dbmodels with central leptin resistance, the new models develop a progressive peripheral leptin resistance and are able to maintain reproductive function. Although the T2D pathophysiology in both TALLYHO/JngJ and NONcNZO10/LtJ is remarkably similar, their genetic etiologies are clearly different, underscoring the genetic heterogeneity underlying T2D in humans.
Stability Analysis of a Vector-Borne Disease with Variable Human Population
Authors: Ozair Muhammad , Lashari Abid Ali , Jung Il Hyo , Seo Young Il , Kim Byul Nim
Published: April 2013

A mathematical model of a vector-borne disease involving variable human population is analyzed. The varying population size includes a term for disease-related deaths. Equilibria and stability are determined for the system of ordinary differential equations. IfR0≤1, the disease-“free” equilibrium is globally asymptotically stable and the disease always dies out. IfR0>1, a unique “endemic” equilibrium is globally asymptotically stable in the interior of feasible region and the disease persists at the “endemic” level. Our theoretical results are sustained by numerical simulations.
Adaptive Multilevel Kernel Machine for Scene Classification
Authors: Hu Junlin , Wang Liang , Duan Fuqing , Guo Ping
Published: April 2013

Scene classification is a challenging problem in computer vision applications and can be used to model and analyze a special complex system, the internet community. The spatial PACT (Principal component Analysis of Census Transform histograms) is a promising representation for recognizing instances and categories of scenes. However, since the original spatial PACT only simply concatenates compact census transform histograms at all levels together, all levels have the same contribution, which ignores the difference among various levels. In order to ameliorate this point, we propose an adaptive multilevel kernel machine method for scene classification. Firstly, it computes a set of basic kernels at each level. Secondly, an effective adaptive weight learning scheme is employed to find the optimal weights for best fusing all these base kernels. Finally, support vector machine with the optimal kernel is used for scene classification. Experiments on two popular benchmark datasets demonstrate that the proposed adaptive multilevel kernel machine method outperforms the original spatial PACT. Moreover, the proposed method is simple and easy to implement.
On the Prediction of Strength from Hardness for Copper Alloys
Authors: Krishna S. Chenna , Gangwar Narendra Kumar , Jha Abhay K. , Pant Bhanu
Published: April 2013

Hardness and strength values of over 55 copper alloys strengthened by solid solution strengthening, precipitation hardening, cold working, and dispersion strengthening were compiled. The yield strength (YS) and ultimate tensile strength (UTS) values of the copper alloys examined ranged between 50 to 1300 MPa and 200 to 1400 MPa, respectively. The compiled values were classified based on strain-hardening potential an indirect method to understand the effect of strain-hardening characteristics. Least squares regression analysis was employed to establish correlations between strength and Vickers hardness values. Strain-hardening potential showed a significant effect on the correlations. In all the cases, a linear relation was obtained for both YS and UTS with hardness for the entire range of values under analysis. Simple empirical equations were proposed to estimate the strength using bulk hardness. The proposed correlations obtained for the entire range of values were verified with experimental values. A good agreement was observed between experimental and predicted values.
Heat-Resistant Ceramic Pigments on the Base of Waste Vanadium Catalyst and Alumina
Authors: Sedelnikova M. B. , Liseenko N. V. , Pautova Y. I. , Pogrebenkov V. M.
Published: April 2013

Ceramic pigments on the base of technogenic silica-containing material—waste vanadium catalyst were obtained in this work. Corundum is identified along with the predominant mullite phase in the composition of pigments. The ions of nickel, chromium, and iron are embedded in the structure if the concentration of the corresponding oxide in the initial mixture does not exceed 10 wt.%. In this case, the oxide is not identified in a free form according to the results of X-ray diffraction analysis. Spinel CoAl2O4 is formed in cobalt pigments. The developed pigments keep the firing temperature up to 1200°C. The obtained pigments may be recommended for ceramic paints and colored glazes for building materials.
Modified Dual-Band Stacked Circularly Polarized Microstrip Antenna
Authors: Liu Guo , Xu Liang , Wang Yi
Published: April 2013

A novel high-performance circularly polarized (CP) antenna is proposed in this paper. Two separate antennas featuring the global positioning system (GPS) dual-band operation (1.575 GHz and 1.227 GHz for L1 band and L2 band, resp.) are integrated with good isolation. To enhance the gain at low angle, a new structure of patch and two parasitic metal elements are introduced. With the optimized design, good axial ratio and near-hemispherical radiation pattern are obtained.
Effect of SPIO Nanoparticle Concentrations on Temperature Changes for Hyperthermia via MRI
Authors: Elsherbini Alsayed A. M. , El-Shahawy Ahmed
Published: April 2013

Magnetic nanoparticles (MNPs) are being developed for a wide range of biomedical applications. In particular, hyperthermia involves heating the MNPs through exposure to an alternating magnetic field (AMF). These materials offer the potential for selectively by heating cancer tissue locally and at the cellular level. This may be a successful method if there are enough particles in a tumor possessing sufficiently high specific absorption rate (SAR) to deposit heat quickly while minimizing thermal damage to surrounding tissue. The current research aim is to study the influence of super paramagnetic iron oxides Fe3O4 (SPIO) NPs concentration on the total heat energy dose and the rate of temperature change in AMF to induce hyperthermia in Ehrlich carcinoma cells implanted in female mice. The results demonstrated a linearly increasing trend between these two factors.
Fixed Points of the Dickson Polynomials of the Second Kind
Authors: Diene Adama , Salim Mohamed A.
Published: April 2013

The permutation behavior of Dickson polynomials of the first kind has been extensively studied, while such behavior for Dickson polynomials of the second kind is less known. Necessary and sufficient conditions for a polynomial of the second kind to be a permutation over some finite fields have been established by Cohen, Matthew, and Henderson. We introduce a new way to define these polynomials and determine the number of their fixed points.
Analysis and Testing of a Natural Convection Solar Dryer for the Tropics
Authors: Adelaja A. O. , Babatope B. I.
Published: April 2013

Solar dryers are imperative for the tropical and sub-Saharan African countries, which are faced with the duo challenges of inadequate electrical energy supply, which has severely limited the application of conventional refrigeration as a means of preservation of agricultural produce, and the need to make produce competitive in the international market. In this study, a cost-effective natural convection solar dryer was developed; the thermal and drying analyses were done and tested to obtain some performance evaluation parameters for the system in order to examine its efficiency and effectiveness by drying some plantain fillets. The collector and system efficiencies are found to be 46.4% and 78.73%, respectively, while a percentage moisture removal of 77.5% was achieved at the 20th hour in order to give final moisture contents of 15.75% in the product, which still maintained its integrity. With a cost of about $195.00, it has been affordable for the small- and medium-scale enterprises as well as for private use in domestic applications.
Recursive Neural Networks Based on PSO for Image Parsing
Authors: Cai Guo-Rong , Chen Shui-Li
Published: April 2013

This paper presents an image parsing algorithm which is based on Particle Swarm Optimization (PSO) and Recursive Neural Networks (RNNs). State-of-the-art method such as traditional RNN-based parsing strategy uses L-BFGS over the complete data for learning the parameters. However, this could cause problems due to the nondifferentiable objective function. In order to solve this problem, the PSO algorithm has been employed to tune the weights of RNN for minimizing the objective. Experimental results obtained on the Stanford background dataset show that our PSO-based training algorithm outperforms traditional RNN, Pixel CRF, region-based energy, simultaneous MRF, and superpixel MRF.
Neurophysiological Basis of Sleep’s Function on Memory and Cognition
Authors: Spencer Rebecca M. C.
Published: April 2013

A wealth of recent studies support a function of sleep on memory and cognitive processing. At a physiological level, sleep supports memory in a number of ways including neural replay and enhanced plasticity in the context of reduced ongoing input. This paper presents behavioral evidence for sleep’s role in selective remembering and forgetting of declarative memories, in generalization of these memories, and in motor skill consolidation. Recent physiological data reviewed suggests how these behavioral changes might be supported by sleep. Importantly, in reviewing these findings, an integrated view of how distinct sleep stages uniquely contribute to memory processing emerges. This model will be useful in developing future behavioral and physiological studies to test predictions that emerge.
The Rabbit as a Model for Studying Lung Disease and Stem Cell Therapy
Authors: Kamaruzaman Nurfatin Asyikhin , Kardia Egi , Kamaldin Nurulain ‘Atikah , Latahir Ahmad Zaeri , Yahaya Badrul Hisham
Published: April 2013

No single animal model can reproduce all of the human features of both acute and chronic lung diseases. However, the rabbit is a reliable model and clinically relevant facsimile of human disease. The similarities between rabbits and humans in terms of airway anatomy and responses to inflammatory mediators highlight the value of this species in the investigation of lung disease pathophysiology and in the development of therapeutic agents. The inflammatory responses shown by the rabbit model, especially in the case of asthma, are comparable with those that occur in humans. The allergic rabbit model has been used extensively in drug screening tests, and this model and humans appear to be sensitive to similar drugs. In addition, recent studies have shown that the rabbit serves as a good platform for cell delivery for the purpose of stem-cell-based therapy.
Existence of Solutions for a Periodic Boundary Value Problem via Generalized Weakly Contractions
Authors: Moradi Sirous , Karapınar Erdal , Aydi Hassen
Published: April 2013

We discuss the existence of solutions for a periodic boundary value problem and for some polynomials. For this purpose, we present some fixed point theorems for weakly and generalized weakly contractive mappings in the setting of partially ordered complete metric spaces.
Salvianolic Acid B Prevents Arsenic Trioxide-Induced CardiotoxicityIn Vivoand Enhances Its Anticancer ActivityIn Vitro
Authors: Wang Min , Sun Guibo , Wu Ping , Chen Rongchang , Yao Fan , Qin Meng , Luo Yun , Sun Hong , Zhang Qiang , Dong Xi , Sun Xiaobo
Published: April 2013

Clinical attempts to reduce the cardiotoxicity of arsenic trioxide (ATO) without compromising its anticancer activities remain to be an unresolved issue. In this study, we determined whether Sal B can protect against ATO-induced cardiac toxicityin vivoand increase the toxicity of ATO toward cancer cells. Combination treatment of Sal B and ATO was investigated using BALB/c mice and human hepatoma (HepG2) cells and human cervical cancer (HeLa) cells. The results showed that the combination treatment significantly improved the ATO-induced loss of cardiac function, attenuated damage of cardiomyocytic structure, and suppressed the ATO-induced release of cardiac enzymes into serum in BALB/c mouse models. The expression levels of Bcl-2 and p-Akt in the mice treated with ATO alone were reduced, whereas those in the mice given the combination treatment were similar to those in the control mice. Moreover, the combination treatment significantly enhanced the ATO-induced cytotoxicity and apoptosis of HepG2 cells and HeLa cells. Increases in apoptotic marker cleaved poly (ADP-ribose) polymerase and decreases in procaspase-3 expressions were observed through western blot. Taken together, these observations indicate that the combination treatment of Sal B and ATO is potentially applicable for treating cancer with reduced cardiotoxic side effects.
In Vitro Hydroxyapatite‐Forming Ability and Antimicrobial Properties of Mesoporous Bioactive Glasses Doped with Ti/Ag
Authors: Lin Huiming , Zhang Jing , Qu Fengyu , Jiang Jingjie , Jiang Pingping
Published: April 2013

Mesoporous bioactive glasses (MBGs) doped with Ti/Ag were synthesized. The structural, morphological, and textural properties of all samples were investigated by small‐angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and N2 adsorption‐desorption technique. In vitro hydroxyapatite‐ (HAP‐) induced growth and antimicrobial properties of these materials were investigated in detail. These results indicate that MBGs‐Ti/Ag possess faster HAP‐induced growth and higher sterilization rate than the pure MBGs materials. With Ti/Ag doping, these functional MBGs show the improved characteristics and have more promising potential in bone‐tissue regeneration systems and surgery.
A Hybrid Approach for Improving the Data Quality of Mobile Phone Sensing
Authors: Min Hong , Scheuermann Peter , Heo Junyoung
Published: April 2013

Few studies have researched the temporal and spatial effects of insufficient exposure of sensors in mobile phone sensing. In this paper, the missing data problem in mobile phone sensing is addressed by using a hybrid approach to design an estimation model. This estimation model reflects the effects of participatory and opportunistic nodes based on the success probability model. The proposed model considers the spatial and temporal correlation of sensing data to accurately estimate the missing information. By applying the linear regression and linear interpolation models to sample data from neighboring nodes of the missing data, the spatial and temporal context can be described. The experiment results show that the proposed model can estimate the missing data accurately in terms of simulated and real-world datasets.
Efficient Serial and Parallel Algorithms for Selection of Unique Oligos in EST Databases
Authors: Mata-Montero Manrique , Shalaby Nabil , Sheppard Bradley
Published: April 2013

Obtaining unique oligos from an EST database is a problem of
great importance in bioinformatics, particularly in the discovery of
new genes and the mapping of the human genome. Many algorithms
have been developed to find unique oligos, many of which are much
less time consuming than the traditional brute force approach. An
algorithm was presented by Zheng et al. (2004)
which finds the solution of the unique oligos search problem efficiently.
We implement this algorithm as well as several new algorithms based
on some theorems included in this paper. We demonstrate how, with
these new algorithms, we can obtain unique oligos much faster than
with previous ones. We parallelize these new algorithms to further
improve the time of finding unique oligos. All algorithms are run on
ESTs obtained from a Barley EST database.
A Simplicial Branch and Bound Duality-Bounds Algorithm to Linear Multiplicative Programming
Authors: Zhou Xue-Gang , Cao Bing-Yuan
Published: April 2013

A simplicial branch and bound duality-bounds algorithm is presented to globally solving the linear multiplicative programming (LMP). We firstly convert the problem (LMP) into an equivalent programming one by introducingpauxiliary variables. During the branch and bound search, the required lower bounds are computed by solving ordinary linear programming problems derived by using a Lagrangian duality theory. The proposed algorithm proves that it is convergent to a global minimum through the solutions to a series of linear programming problems. Some examples are given to illustrate the feasibility of the present algorithm.
Studies on Electric and Dielectric Properties of Porous Sm0.5Sr0.5CoO3−δ
Authors: Pawar S. S. , Shinde K. P. , Bhosale A. G. , Pawar S. H.
Published: April 2013

Frequency-dependent electric and dielectric properties of the porous Sm0.5Sr0.5CoO3−δ cathode prepared through conventional combustion synthesis technique were studied in the temperature range 298 K–973 K. The crystal symmetry, space group, and unit cell dimensions were confirmed by analyzing XRD pattern. XRD analysis indicates the formation of a single-phase orthorhombic structure with space group Pnma 62. Scanning electron microscopy technique was used to examine the morphology of the sample. Scanning electron microscopy study showed the formation of porous structure with an average grain size about 850 nm. From the electrical study, it is observed that the conduction in Sm0.5Sr0.5CoO3−δ sample takes place through the hopping mechanism and follows the inverse universal power law. The correlated barrier hopping model was employed successfully to explain the mechanism of charge transport in Sm0.5Sr0.5CoO3−δ. Further, the ac conductivity data was used to evaluate the minimum hopping length and apparent activation energy. The minimum hopping length was found to be ~10−4 times smaller than the grain size of Sm0.5Sr0.5CoO3−δ. The peaking behaviour of the real part of dielectric constant with frequency was explained using the Rezlescu model. This study helps to confirm that the charge transportation in Sm0.5Sr0.5CoO3−δ is due to two types of charge carriers.
Variable morphology of the Madagascar endemic Aristida tenuissima (Poaceae: Aristidoideae) and the absence of Stipa (Poaceae: Pooideae, Stipeae) from Madagascar
Authors: VORONTSOVA MARIA S.
Published: April 2013

The widespread and species rich grass genera Aristida Linnaeus (1753: 82; Aristidoideae) and Stipa Linnaeus (1753: 78; Stipeae) are ordinarily simple to distinguish by the characteristic three awns in Aristida and a single awn in Stipa. A study of Aristida in Madagascar shows that the Madagascar endemic Stipa perrieri A.Camus (1934: 593) is in fact a 1-awned variant of Aristida tenuissima Camus (1933: 844) described and illustrated by Bosser (1969). There are no collections of Stipa or other members of Stipeae recorded from Madagascar.
Significant range extensions for two caddid harvestmen in eastern North America, Caddo pepperella and Acropsopilio boopis (Opiliones: Eupnoi: Caddidae)
Authors: SHULTZ JEFFREY W.
Published: April 2013

Three caddid harvestmen are known from eastern North America—Caddo agilis Banks, C. pepperella Shear and Acropsopilio boopis (Crosby) (Fig. 1). All also occur in Japan (Suzuki 1976; Shultz & Regier 2007), and all are apparently parthenogenetic, although a few male specimens of C. agilis are known (Gruber 1974, Suzuki & Tsurusaki 1983). The three species can be distinguished from other harvestmen by their large eye tubercle (ocularium), which occupies most of the carapace, as well as pedipalps with a proximal series of ventral spines. Acroposopilio boopis can be readily distinguished from the two Caddo species by its smaller size (body length < 1 mm in A. boopis versus 1.6–3.2 mm in Caddo) and the pedipalpal tarsus is shorter than the tibia rather than longer. (Fig. 1; Shear 1975). Caddo species can be difficult to separate as juveniles, but adult C. pepperella are smaller than C. agilis, (body length 1.6–1.9 mm in C. pepperella versus 2.8–3.2 mm in C. agilis) and the cuticle is brownish without prominent white or silver dorsal markings (Fig. 1; Shear 1975). In addition, the metapeltidium in C. pepperella bears a medial pair of fine erect projections that are absent in C. agilis (Shultz 1998).