bluuebunny/crossref_metadata_2025 huggingface dataset:
Personality differences in mental imagery and the effects on verbal memory
Authors: McDougall Siné , Pfeifer Gaby
Published: January 2012

This study examined the effects of extraversion and neuroticism on participants’ reported vividness of visual imagery and on their memory performance for concrete and abstract nouns. Groups of extraverts (n = 15) and introverts (n = 15) were selected from a larger original sample and asked to remember a series of concrete and abstract nouns, including a set of lexically ambiguous concrete homonyms (e.g., earth = 1. planet, 2. soil). Extraverts reported more vivid imagery than introverts but this did not translate into better recall for extraverts, even for concrete stimuli. Recall was best for unambiguous concrete nouns, followed by concrete homonyms, then abstract nouns. While initial analyses suggested that there was an interaction between extraversion and the type of word presented, later analyses revealed that neuroticism was the main driver in differences in recall between different word types. While differences in recall were best explained by context availability theory (Schwanenflugel, 1991) rather than dual coding theory (Paivio, 1991), questions remain about the power of either theory to explain the role of individual differences in personality on recall, particularly given that imagery vividness effects were related to extraversion while differences in recall were related to neuroticism. The implications of these findings for future research and theoretical development are discussed.
Na+ transport across rumen epithelium of hay‐fed sheep is acutely stimulated by the peptide IGF‐1 in vitro
Authors: Shen Zanming , Martens Holger , Schweigel‐Röntgen Monika
Published: January 2012

An energy‐rich diet leads to enhanced ruminal Na+ absorption, which is associated with elevated plasma insulin‐like growth factor 1 (IGF‐1) levels and an increased number of IGF‐1 receptors in rumen papillae. This study examined the in vitro effect of IGF‐1 on Na+ transport across the rumen epithelium of hay‐fed sheep, in which the IGF‐1 concentration in plasma is lower than in concentrate‐fed animals. At concentrations ranging from 20 to 100 μg l−1, serosal LR3‐IGF‐1, a recombinant analogue of IGF‐1, rapidly (within 30 min) stimulated the mucosal‐to‐serosal Na+ flux (JmsNa) and consequently the net Na+ flux (JnetNa). Compared with controls, JnetNa increased by about 60% (P < 0.05) following the serosal application of LR3‐IGF‐1 (20 μg l−1). The IGF‐1‐induced increment of JmsNa and JnetNa was inhibited by mucosal amiloride (1 mmol l−1). Neither IGF‐1 nor amiloride altered tissue conductance or the short‐circuit current of the isolated rumen epithelium. These data support the assumption that the stimulating effect of serosally applied IGF‐1 on Na+ transport across the rumen epithelium is mediated by Na+–H+ exchange (NHE). A further study was performed with cultured rumen epithelial cells and a fluorescent probe (BCECF) to estimate the rate of pHi recovery after acid loading. The pHi of isolated rumen epithelial cells was 6.43 ± 0.15 after butyrate loading and recovered by 0.26 ± 0.02 pH units (15 min)−1. Application of LR3‐IGF‐1 (20 μg l−1) significantly increased the rate of pHi recovery to 0.33 ± 0.02 pH units (15 min)−1. Amiloride administration reduced the recovery rate in both control and IGF‐1‐stimulated cells. These results show, for the first time, that an acute effect of IGF‐1 on Na+ absorption across rumen epithelium results from increased NHE activity. Insulin‐like growth factor 1 is thus important for the fast functional adaptation of ruminal Na+ transport via NHE.
Potential Detrimental Consequences of Excessive PWHT on Pressure Vessel Steel Properties
Authors: Chauvy Cédric , Coudreuse Lionel , Toussaint Patrick
Published: January 2012

During fabrication of Pressure Vessels, steels undergo several heat treatments that aim to confer the required properties on the entire equipment, including welds and base metal. Indeed, the production heat treatment of the base material, which leads to achieve the target properties, is most of the time followed by post weld heat treatment (PWHT). The aim of such treatments is to insure a good behavior of the welded zones in terms of residual stresses and obviously properties such as toughness. Generally, many simulated PWHT (up to 4 or more) are required for the testing of the base material, which can affect its properties and even lead to unacceptable results. In some cases for fabrication purposes an intermediate Stress relieving treatment can be required. Special attention is paid on C-Mn steels (e.g., SA/A516 from ASME BPV Code) with the effect of thickness and Ceq (International Institute of Welding Carbon equivalent formula: see page 3) requirements on the final compromise between properties and heat treatments. In particular, toughness and ultimate tensile strength (UTS) are the critical parameters that will limit the acceptance of too high PWHT. Although micro-alloying is a mean to increase the resistance to PWHT, this leads to difficulties in softening the heat affected zones. This solution is therefore not the best one considering the whole equipment optimization. Finally, the manufacturing process can play a major role when specifications are stringent. Quenching and tempering (Q&T) can indeed provide better flexibility in terms of PWHT and improved toughness for given Ceq and thickness. The case of Cr-Mo(-V) steels, which are widely used in the energy industry, is also addressed. Indeed, PWHT requirements for increasing the toughness in the weld metal can lead to decrease the base metal properties below the specification limits. For example, the case of SA/A387gr11 is very typical of metallurgical changes that can occur during these high PWHT leading to a degradation of toughness in the base metal. Another focus is made on the Vanadium Cr-Mo grade SA/A542D that must withstand very high PWHT (705 °C and even 710 °C) because of welds toughness issues. Optimization has therefore to be done to increase the resistance to softening and to guarantee acceptable microstructure, especially in the case of thick wall vessels. Some ways for improvement are proposed on the basis of the equivalent Larson–Miller parameter (LMP) tempering parameter concept. The basic philosophy is to fulfil the need for discussion between companies involved in pressure vessels fabrication so that the best compromise can be found to ensure the best and safest behavior of the equipment as a whole. In particular, the tempering operation can sometimes be done at lower temperature than PWHT in order to offer the best properties to the final vessel.
Recent Advances in Turbine Heat Transfer—With A View of Transition to Coal-Gas Based Systems
Authors: Chyu Minking K.
Published: January 2012

The performance goal of modern gas turbine engines, both land-base and air-breathing engines, can be achieved by increasing the turbine inlet temperature (TIT). The level of TIT in the near future can reach as high as 1700 °C for utility turbines and over 1900 °C for advanced military engines. To ensure the turbine airfoil component integrity operated under such a condition, advanced cooling capacity by both external and internal means was necessary to remove the excessive heat load from the turbine airfoil. This paper discusses state-of-the-art airfoil cooling technologies along with the associated thermal transport issues. Discussion is given based on five key regions on and around an airfoil: leading edge, main body, trailing edge, endwall, and near-tip. Potential implications and challenges of near-term developments in coal-gas based turbines on the cooling technologies are identified. A literature survey focusing primarily on the past 4–5years since the last International Heat Transfer Conference has also been performed.
Transient Thermocapillary Convection in a Molten or Weld Pool
Authors: Wei P. S. , Lin C. L. , Liu H. J. , Ting C. N.
Published: January 2012

This study presents a numerical scenario for the effect of thermocapillary convection on the transient, two-dimensional molten pool shape during welding or melting. Tracing the melting process is necessary to achieve a better and more complete understanding of the physical mechanism of welding. This model is used to simulate a steady state, three-dimensional welding process, by introducing an incident flux with a Gaussian distribution with a time-dependent radius determined by scanning speed and distribution parameter. Aside from presenting the variations of peak surface velocities and temperature, and depth and width of the molten pool with time, the predicted results of this work show that surface velocity and temperature profiles for a high Prandtl number strongly deform in the course of melting. The velocity profile eventually exhibits two peaks, located near the edges of the incident flux and the pool, respectively. Conversely, only one peak velocity occurs near the pool edge for a small Prandtl number. In all cases, surface temperature can ultimately be divided into hot, intermediate, and cold regions. The pool becomes deep due to an induced secondary vortex cell near the bottom of the pool for a small Prandtl number. For a high Prandtl number, the pool edge is thin and shallow, as a result of penetration into the solid near the top surface. The predicted results agree with those obtained using a commercial computer code.
Partial Transient Liquid Phase Diffusion Bonding of Zircaloy-4 to Stabilized Austenitic Stainless Steel 321 Using Titanium Interlayer
Authors: Atabaki M. Mazar , Idris J.
Published: January 2012

In this study, an innovative method was applied for bonding Zircaloy-4 to stabilized austenitic stainless steel 321 using an active titanium interlayer. Specimens were joined by partial transient liquid phase diffusion bonding method in a vacuum furnace at different temperatures under 1 MPa dynamic pressure of contact. The influence of different bonding temperatures on the microstructure, microindentation hardness, joint strength, and interlayer thickness has been studied. Additionally, a simple numerical model was developed to predict the evolution of interlayer during partial transient liquid phase diffusion bonding. Diffusion of Fe, Cr, Ni, and Zr has been investigated by scanning electron microscopy examinations and energy dispersive spectroscopy elemental analyses. Results showed that control of heating and cooling rate and 20 min soaking at 1223 K produces a perfect joint. However, solid state diffusion of the melting point depressant elements into the joint metal causes the solid/liquid interface to advance until the joint is solidified. The tensile strength values of all bonded specimens were found around 480–670 MPa. Energy dispersive spectroscopy studies indicated that the melting occurred along the interface of bonded specimens as a result of transfer of atoms between the interlayer and the matrix during bonding. The evolution of interlayer film thickness indicates a good agreement between the calculation and experimental measurement. This technique provides a reliable method of bonding zirconium alloy to stainless steel.
A Proposed Model for Predicting Clamp Load Loss Due to Gasket Creep Relaxation in Bolted Joints
Authors: Housari Basil A. , Alkelani Ali A. , Nassar Sayed A.
Published: January 2012

An improved mathematical model is proposed for predicting clamp load loss due gasket creep relaxation in bolted joints, taking into consideration gasket behavior, bolt stiffness, and joint stiffness. The gasket creep relaxation behavior is represented by a number of parameters which has been obtained experimentally in a previous work. An experimental procedure is developed to verify the proposed model using a single-bolt joint. The bolt is tightened to a target preload and the clamp load loss due to gasket creep relaxation is observed over time under various preload levels. The experimental and analytical results are presented and discussed. The proposed model provides a prediction of the residual clamp load as a function of time, gasket material and thickness, bolt stiffness, and joint stiffness. The improved model can be used to simulate the behavior of creep relaxation in soft joints as the joint stiffness effect is considered. Additionally, a closed form solution is formulated to determine the initial clamp load level necessary to provide the desired level of a steady state residual clamp load in the joint, by taking the gasket creep relaxation into account.
A New FIX for Hemophilia B
Authors: Evans-Molina Carmella
Published: January 2012

An improved gene therapy strategy results in an encouraging reduction in factor IX infusions for hemophilia B patients.
Rhodococcus sp. Strain CR-53 LipR, the First Member of a New Bacterial Lipase Family (Family X) Displaying an Unusual Y-Type Oxyanion Hole, Similar to the Candida antarctica Lipase Clan
Authors: Bassegoda Arnau , Pastor F. I. Javier , Diaz Pilar
Published: January 2012

Bacterial lipases constitute the most important group of biocatalysts for synthetic organic chemistry. Accordingly, there is substantial interest in developing new valuable lipases. Considering the lack of information concerning the lipases of the genus
Rhodococcus
and taking into account the interest raised by the enzymes produced by actinomycetes, a search for putative lipase-encoding genes from
Rhodococcus
sp. strain CR-53 was performed. We isolated, cloned, purified, and characterized LipR, the first lipase described from the genus
Rhodococcus
. LipR is a mesophilic enzyme showing preference for medium-chain-length acyl groups without showing interfacial activation. It displays good long-term stability and high tolerance for the presence of ions and chemical agents in the reaction mixture. Amino acid sequence analysis of LipR revealed that it displays four unique amino acid sequence motifs that clearly separate it from any other previously described family of bacterial lipases. Using bioinformatics tools, LipR could be related only to several uncharacterized putative lipases from different bacterial origins, all of which display the four blocks of consensus amino acid sequence motifs that contribute to define a new family of bacterial lipases, namely, family X. Therefore, LipR is the first characterized member of the new bacterial lipase family X. Further confirmation of this new family of lipases was performed after cloning
Burkholderia cenocepacia
putative lipase, bearing the same conserved motifs and clustering in family X. Interestingly, all lipases grouping in the new bacterial lipase family X display a Y-type oxyanion hole, a motif conserved in the
Candida antarctica
lipase clan but never found among bacterial lipases. This observation contributes to confirm that LipR and its homologs belong to a new family of bacterial lipases.
Characterization of Two Bacterial Hydroxynitrile Lyases with High Similarity to Cupin Superfamily Proteins
Authors: Hussain Zahid , Wiedner Romana , Steiner Kerstin , Hajek Tanja , Avi Manuela , Hecher Bianca , Sessitsch Angela , Schwab Helmut
Published: January 2012

Hydroxynitrile lyases (HNLs) catalyze the cleavage of cyanohydrins. In the reverse reaction, they catalyze the formation of carbon-carbon bonds by enantioselective condensation of hydrocyanic acid with carbonyls. In this study, we describe two proteins from endophytic bacteria that display activity in the cleavage and the synthesis reaction of (
R
)-mandelonitrile with up to 74% conversion of benzaldehyde (enantiopreference
ee
89%). Both showed high similarity to proteins of the cupin superfamily which so far were not known to exhibit HNL activity.
Abundance, Dynamics, and Biogeographic Distribution of Seven Polycyclic Aromatic Hydrocarbon Dioxygenase Gene Variants in Coastal Sediments of Patagonia
Authors: Marcos Magalí S. , Lozada Mariana , Di Marzio Walter D. , Dionisi Hebe M.
Published: January 2012

Novel polycyclic aromatic hydrocarbon dioxygenase gene variants were present in abundances similar to or higher than those of
phnA1
from
Cycloclasticus
spp. at a chronically polluted subantarctic coastal marine environment in Patagonia. These novel gene variants were detected over a 6-year time span and were also present in sediments from temperate Patagonian sites.
Aerosol Susceptibility of Influenza Virus to UV-C Light
Authors: McDevitt James J. , Rudnick Stephen N. , Radonovich Lewis J.
Published: January 2012

The person-to-person transmission of influenza virus, especially in the event of a pandemic caused by a highly virulent strain of influenza, such as H5N1 avian influenza, is of great concern due to widespread mortality and morbidity. The consequences of seasonal influenza are also substantial. Because airborne transmission appears to play a role in the spread of influenza, public health interventions should focus on preventing or interrupting this process. Air disinfection via upper-room 254-nm germicidal UV (UV-C) light in public buildings may be able to reduce influenza transmission via the airborne route. We characterized the susceptibility of influenza A virus (H1N1, PR-8) aerosols to UV-C light using a benchtop chamber equipped with a UVC exposure window. We evaluated virus susceptibility to UV-C doses ranging from 4 to 12 J/m
2
at three relative humidity levels (25, 50, and 75%). Our data show that the Z values (susceptibility factors) were higher (more susceptible) to UV-C than what has been reported previously. Furthermore, dose-response plots showed that influenza virus susceptibility increases with decreasing relative humidity. This work provides an essential scientific basis for designing and utilizing effective upper-room UV-C light installations for the prevention of the airborne transmission of influenza by characterizing its susceptibility to UV-C.
Characterization of Halomonas sp. Strain H11 α-Glucosidase Activated by Monovalent Cations and Its Application for Efficient Synthesis of α-
d
-Glucosylglycerol
Authors: Ojima Teruyo , Saburi Wataru , Yamamoto Takeshi , Kudo Toshiaki
Published: January 2012

An α-glucosidase (HaG) with the following unique properties was isolated from
Halomonas
sp. strain H11: (i) high transglucosylation activity, (ii) activation by monovalent cations, and (iii) very narrow substrate specificity. The molecular mass of the purified HaG was estimated to be 58 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). HaG showed high hydrolytic activities toward maltose, sucrose, and
p
-nitrophenyl α-
d
-glucoside (
p
NPG) but to almost no other disaccharides or malto-oligosaccharides higher than trisaccharides. HaG showed optimum activity to maltose at 30°C and pH 6.5. Monovalent cations such as K
+
, Rb
+
, Cs
+
, and NH
4
+
increased the enzymatic activity to 2- to 9-fold of the original activity. These ions shifted the activity-pH profile to the alkaline side. The optimum temperature rose to 40°C in the presence of 10 mM NH
4
+
, although temperature stability was not affected. The apparent

K
m

and
k
cat
values for maltose and
p
NPG were significantly improved by monovalent cations. Surprisingly,
k
cat
/

K
m

for
p
NPG increased 372- to 969-fold in their presence. HaG used some alcohols as acceptor substrates in transglucosylation and was useful for efficient synthesis of α-
d
-glucosylglycerol. The efficiency of the production level was superior to that of the previously reported enzyme
Aspergillus niger
α-glucosidase in terms of small amounts of by-products. Sequence analysis of HaG revealed that it was classified in glycoside hydrolase family 13. Its amino acid sequence showed high identities, 60%, 58%, 57%, and 56%, to
Xanthomonas campestris
WU-9701 α-glucosidase,
Xanthomonas campestris
pv. raphani 756C oligo-1,6-glucosidase,
Pseudomonas stutzeri
DSM 4166 oligo-1,6-glucosidase, and
Agrobacterium tumefaciens
F2 α-glucosidase, respectively.
The Ubiquitin Ligase Ubr11 Is Essential for Oligopeptide Utilization in the Fission Yeast Schizosaccharomyces pombe
Authors: Kitamura Kenji , Nakase Mai , Tohda Hideki , Takegawa Kaoru
Published: January 2012

Uptake of extracellular oligopeptides in yeast is mediated mainly by specific transporters of the peptide transporter (PTR) and oligopeptide transporter (OPT) families. Here, we investigated the role of potential peptide transporters in the yeast
Schizosaccharomyces pombe
. Utilization of naturally occurring dipeptides required only Ptr2/SPBC13A2.04c and none of the other 3 OPT proteins (Isp4, Pgt1, and Opt3), whereas only Isp4 was indispensable for tetrapeptide utilization. Both Ptr2 and Isp4 localized to the cell surface, but under rich nutrient conditions Isp4 localized in the Golgi apparatus through the function of the ubiquitin ligase Pub1. Furthermore, the ubiquitin ligase Ubr11 played a significant role in oligopeptide utilization. The mRNA levels of both the
ptr2
and
isp4
genes were significantly reduced in
ubr11
Δ cells, and the dipeptide utilization defect in the
ubr11
Δ mutant was rescued by the forced expression of Ptr2. Consistent with its role in transcriptional regulation of peptide transporter genes, the Ubr11 protein was accumulated in the nucleus. Unlike the situation in
Saccharomyces cerevisiae
, the oligopeptide utilization defect in the
S. pombe
ubr11
Δ mutant was not rescued by inactivation of the Tup11/12 transcriptional corepressors, suggesting that the requirement for the Ubr ubiquitin ligase in the upregulation of peptide transporter mRNA levels is conserved in both yeasts; however, the actual mechanism underlying the control appears to be different. We also found that the peptidomimetic proteasome inhibitor MG132 was still operative in a strain lacking all known PTR and OPT peptide transporters. Therefore, irrespective of its peptide-like structure, MG132 is carried into cells independently of the representative peptide transporters.
Roles of Long and Short Replication Initiation Proteins in the Fate of IncP-1 Plasmids
Authors: Yano Hirokazu , Deckert Gail E. , Rogers Linda M. , Top Eva M.
Published: January 2012

Broad-host-range IncP-1 plasmids generally encode two replication initiation proteins, TrfA1 and TrfA2. TrfA2 is produced from an internal translational start site withintrfA1. While TrfA1 was previously shown to be essential for replication inPseudomonas aeruginosa, its role in other bacteria within its broad host range has not been established. To address the role of TrfA1 and TrfA2 in other hosts, efficiency of transformation, plasmid copy number (PCN), and plasmid stability were first compared between a mini-IncP-1β plasmid and itstrfA1frameshift variant in four phylogenetically distant hosts:Escherichia coli,Pseudomonas putida,Sphingobium japonicum, andCupriavidus necator. TrfA2 was sufficient for replication in these hosts, but the presence of TrfA1 enhanced transformation efficiency and PCN. However, TrfA1 did not contribute to, and even negatively affected, long-term plasmid persistence. WhentrfAgenes were cloned under a constitutive promoter in the chromosomes of the four hosts, strains expressing either both TrfA1 and TrfA2 or TrfA1 alone, again, generally elicited a higher PCN of an IncP1-β replicon than strains expressing TrfA2 alone. When a single species of TrfA was produced at different concentrations inE. colicells, TrfA1 maintained a 3- to 4-fold higher PCN than TrfA2 at the same TrfA concentrations, indicating that replication mediated by TrfA1 is more efficient than that by TrfA2. These results suggest that the broad-host-range properties of IncP-1 plasmids are essentially conferred by TrfA2 and the intact replication origin alone but that TrfA1 is nonetheless important to efficiently establish plasmid replication upon transfer into a broad range of hosts.
Three-Dimensional Structures of Pathogenic and Saprophytic Leptospira Species Revealed by Cryo-Electron Tomography
Authors: Raddi Gianmarco , Morado Dustin R. , Yan Jie , Haake David A. , Yang X. Frank , Liu Jun
Published: January 2012

Leptospira interrogansis the primary causative agent of the most widespread zoonotic disease, leptospirosis. An in-depth structural characterization ofL. interrogansis needed to understand its biology and pathogenesis. In this study, cryo-electron tomography (cryo-ET) was used to compare pathogenic and saprophytic species and examine the unique morphological features of this group of bacteria. Specifically, our study revealed a structural difference between the cell envelopes ofL. interrogansandLeptospirabiflexainvolving variations in the lipopolysaccharide (LPS) layer. Through cryo-ET and subvolume averaging, we determined the first three-dimensional (3-D) structure of the flagellar motor of leptospira, with novel features in the flagellar C ring, export apparatus, and stator. Together with direct visualization of chemoreceptor arrays, DNA packing, periplasmic filaments, spherical cytoplasmic bodies, and a unique “cap” at the cell end, this report provides structural insights into these fascinatingLeptospiraspecies.
Can Medical Thermal Images Predict Acupuncture Adverse Events? A Case History
Authors: Norheim Arne Johan , Mercer James
Published: January 2012

Malaise and fainting are unpleasant acupuncture adverse effects. This paper shows how the use of thermography might identify subjects before the systematic responses become clinically significant.
Getting involved in clinical trials research in the UK: how can Clinical Research Networks help?
Authors: Hull Mark A , Yiannakou Yan , Gower Jonathan , Ryder Stephen D , Bloom Stuart L , Rees Colin R
Published: January 2012

The Clinical Research Networks of the National Institute of Health Research have transformed clinical research in the UK, leading to a doubling in the number of patients involved in clinical research studies over the past 3 years. This has been achieved by streamlining the trials approvals process, by providing local infrastructure such as research nurse support for clinical trials recruitment and through recognition of the time and funding necessary for clinicians to contribute to clinical research. Here, we describe the structure and roles of the Comprehensive Clinical Research Networks in gastrointestinal disease and hepatology, particularly in England. We will explain how the networks have already accelerated clinical research in gastrointestinal and liver disease, as well as provide a simple guide about how individual clinicians can contribute to ongoing studies via the networks.
Minimum monitoring for financial health
Authors: Gripper Peter
Published: January 2012

Maintaining financial success is important for every business, and a good manager should track its performance at a number of levels. These parameters may be interlinked and complex, so it is vital to be able to interpret the data collected. In this article, Peter Gripper describes some useful measures of financial performance and explains the importance of internal and external benchmarks.
Keeping it legal: delegation to veterinary nurses
Authors: Branscombe Liz
Published: January 2012

Last year marked the 50th anniversary of veterinary nursing and, with non‐statutory regulation of the profession being sought by the majority of its members, it is timely to consider the veterinary nurse's role. In this article, Liz Branscombe explains the procedures that can legally be delegated to veterinary nurses within the veterinary practice, as covered by Schedule 3 of the Veterinary Surgeons Act 1966.
Abdominal ultrasonography as an adjunct to clinical examination 1. Small ruminants
Authors: Scott Phil
Published: January 2012

Abdominal ultrasonography is a diagnostic technique that can be used in farm animal practice as a complementary adjunct to a thorough clinical examination. This article describes the ultrasonographic findings that can be visualised in the abdomen of small ruminants and outlines some of the common indications for ultrasonography. It illustrates how this modality can be readily incorporated into a clinical examination on farm to provide an accurate demonstration of underlying pathology. A second article, to be published in the February issue of In Practice, will discuss the use of abdominal ultrasonography in cattle.
Taxonomy of Astragalus robbinsii var. fernaldii (Fabaceae): molecular and morphological analyses support transfer to Astragalus eucosmus
Authors: Sokoloff Paul C. , Gillespie Lynn J.
Published: January 2012

Astragalus robbinsii var. fernaldii , Fernald’s milkvetch, is a taxon of conservation concern currently due for reassessment of its provincial and federal conservation status. Restricted to a narrow region spanning Newfoundland and Labrador and Quebec, its taxonomic position with respect to two congeners, Astragalus eucosmus and Astragalus robbinsii var. minor , is poorly understood. To clarify the taxonomy of Fernald’s milkvetch, we studied variation in the ycf6–trnC and trnC–rpoB chloroplast DNA (cpDNA) spacers, generated amplified fragment length polymorphism (AFLP) genotypes, and conducted a morphometric analysis. Parsimony and Bayesian analysis of the cpDNA data distinguished A. robbinsii var. minor from A. eucosmus and the majority of Fernald's milkvetch samples; both cpDNA and AFLP analysis were highly suggestive of gene flow between taxa and populations. Morphometric analysis indicates that Fernald's milkvetch is closer to A. eucosmus than to A. robbinsii var. minor in overall form and stipe length, while pubescence was not taxonomically informative. Based on these results, the recognition of Fernald's milkvetch is unwarranted; we recommend that the taxon be transferred to A. eucosmus.
HETEROGENEITY ON THE TECHNICAL EFFICIENCY IN JAPANESE AIRPORTS
Authors: BARROS CARLOS PESTANA , MANAGI SHUNSUKE , YOSHIDA YUICHIRO
Published: January 2012

This paper evaluates the production activities of Japanese airports by using a finite mixture model that allows controlling for unobserved heterogeneity. In doing so, a stochastic frontier latent class model, which allows the existence of different technologies, is adopted to estimate production frontiers. This procedure not only enables the identification of different groups of Japanese airports but also permits the analysis of their production efficiency. The main result is that there are two groups of Japanese airports, both following completely different "technologies" to obtain passengers and cargo, suggesting that business strategies need to be adapted to the characteristics of the airports. Some managerial implications are developed.
COLLISION ENERGY IN THE CENTER-OF-MASS FRAME FOR ROTATING AND ACCELERATING BLACK HOLES
Authors: HUSSAIN IBRAR
Published: January 2012

The center-of-mass (CM) energy of collision for two uncharged particles falling freely from rest at infinity is investigated in the background of charged, rotating and accelerating black hole. It is found that the CM energy of collision is unlimited at the acceleration horizon and at the event horizon (in the extremal case) if one of the colliding particles has critical angular momentum and the other one has a proper angular momentum such that the particle can reach the horizon.
TOWARDS A PROOF OF AGT CONJECTURE BY METHODS OF MATRIX MODELS
Authors: MIRONOV A. , MOROZOV A. , SHAKIROV SH.
Published: January 2012

A matrix model approach to proof of the AGT relation is briefly reviewed. It starts from the substitution of conformal blocks by the Dotsenko–Fateev β-ensemble averages and Nekrasov functions by a double deformation of the exponentiated Seiberg–Witten prepotential in β≠1 and gs≠0 directions. Establishing the equality of these two quantities is a typical matrix model problem.
FLAVOR AND SPIN DEPENDENT STRUCTURE OF THE NUCLEON AND MESON
Authors: MIRJALILI ABOLFAZL , KESHAVARZIAN KIANOOSH , YAZDANPANAH MOHAMMAD MEHDI
Published: January 2012

We employ the polarized chiral constituent quarks to extract the polarized structure function of the nucleon. The polarized valon model is used to calculate the spin dependence of parton distribution functions of meson. The connection between the polarized structure of the proton and the Goldstone bosons, using the chiral quark model (χQM) is analyzed and the spin dependence of the parton distribution functions for pion and kaon, is obtained thoroughly. These functions are evolved to high Q2 values, using the singlet, nonsinglet and quark–gluon moments (ΔMS, ΔMNS, ΔMgq) which are convoluted with the polarized valon distributions. The polarized valon distributions for meson are computed, based on a phenomenological method and a comparison between polarized and unpolarized parton distribution functions for pion and kaon are performed. As a consequence of the χQM, the SU (3)f symmetry breaking for the spin dependent of the nucleon sea distributions is achieved. The required polarized parton distributions of the proton will be obtained from the parton distribution functions of the polarized meson via the related convolution integral which are existed in the χQM. Following that the analytical result for the proton's spin structure function, [Formula: see text], is obtained and compared with experimental data. Finally, the parton orbital angular momentum of meson are introduced and the total spin of the meson, based on this quantity and the first moment of distributions for gluon and singlet sectors, are obtained.
ELECTROMAGNETIC GUIDED WAVES IN A METAMATERIAL-MAGNETIC WAVEGUIDE STRUCTURE
Authors: MOUSA H. M. , SHABAT M. M.
Published: January 2012

The growing and rapid interest in new artificial metamaterials, whose properties differ from the normal materials has motivated further investigations. The metamaterials have simultaneously negative permittivity and permeability. In this work, we have demonstrated theoretically the existence and behavior of the TE guided waves in a ferromagnetic/metamaterial/antiferromagnetic waveguide structure. The dispersion characteristics are performed for different kinds of metamaterials. The existence and the type of the solutions to the guided waves with respect to different physical parameters are also investigated and discussed. It has been shown that the metamaterials can lead to different, new unusual properties.
AB INITIO THERMODYNAMICS OF ZINC-BLENDE ZnS, ZnSe
Authors: WANG HUAN-YOU , XU HUI , CAO JU-YING , LI MING-JUN
Published: January 2012

The density function perturbation theory (DFPT) is employed to study the linear thermal expansion and heat capacity at constant pressure (with the quasiharmonic approximation). The calculations are performed using a pseudopotential plane wave method and local density approximation for the exchange-correlation potential. The calculated results of linear thermal expansion coefficient and heat capacity at constant pressure for zinc-blende ZnS , ZnSe are compared with the available experimental data in a wide temperature range. Generally, in low-temperature range, they have good agreement. However, in high-temperature range, due to anharmonic effect and other reasons, lead to larger errors for these properties between the theoretical results and available experimental data.
MULTIFERROISM AND MAGNETOELECTRIC COUPLING IN NANO-MICROSCALE LEAD-FREE COMPOSITE BY 0.3Co-FERRITE AND 0.7(K0.5Na0.5)NbO3-BASED FERROELECTRIC MATRIX
Authors: ZHOU YUN , WANG XINYAN , LI LI , SU YULING , ZHANG JINCANG , CAO SHIXUN
Published: January 2012

Nontoxic lead-free multiferroic composites are synthesized by incorporating the dispersed 0.3 CoFe 2 O 4 (CFO) ferromagnetic nanoparticles into 0.7( K 0.5 Na 0.5) NbO 3- LiSbO 3 (KNN-LS5.2) ferroelectric micromatrix. The multiferroicity of the composite can be verified by polarization-electric field hysteresis loop and magnetic hysteresis loop. The composite exhibits excellent magnetic properties. A dilution effect is observed in magnetic hysteresis loops. The field dependence of ME voltage coefficient is given as a function of magnetic field from -4 kOe to 4 kOe with a maximum magnetoelectric voltage coefficient of 10.7 mV ⋅ cm -1⋅ Oe -1 at the frequency of 1 kHz. It is a very high value in the lead-free magnetoelectric composites system for the potential use on multifunctional devices.
SYNCHRONIZATION AND ANTICOHERENCE RESONANCE OF BURSTING NEURONS WITH SPATIALLY CORRELATED NOISE
Authors: LANG XIUFENG , LU QISHAO , JI LIN
Published: January 2012

We investigate synchronization of bursting neurons, caused by spatially correlated noise, consisting of a common Guassian noise and a local one. It is found that the degree of noise-induced synchronization between identical neurons increases with both the noise intensity and noise correlation. As for non-identical neurons, it is demonstrated that the degree of phase synchronization decreases monotonously with the noise intensity for partially correlated noise, but the degree undergoes a minimum with the common noise intensity increasing. An interpretation is provided for the noise-induced synchronization between identical neurons by investigating noise-modulated spike train pattern in a single neuron. In addition, the coherence of spike train is minimized at some noise intensities.
ON A NEW NUMERICAL METHOD FOR SOLVING GENERAL VARIATIONAL INEQUALITIES
Authors: BNOUHACHEM ABDELLAH , NOOR MUHAMMAD ASLAM , KHALFAOUI MOHAMED , SHENG ZHAOHAN
Published: January 2012

In this paper, we suggest and analyze a new extragradient method for solving the general variational inequalities involving two operators. We also prove the global convergence of the proposed modified method under certain mild conditions. We used a self-adaptive technique to adjust parameter ρ at each iteration. It is proved theoretically that the lower-bound of the progress obtained by the proposed method is greater than that by the extragradient method. An example is given to illustrate the efficiency and its comparison with the extragradient method. Since the general variational inequalities include the classical variational inequalities and complementarity problems as special cases, our results obtained in this paper continue to hold for these problems. Results obtained in this paper may be viewed as an improvement and refinement of the previously known results in this field.
EXCITON-MEDIATED RAMAN SCATTERING IN ONE-DIMENSIONAL QUANTUM DOTS
Authors: SUN HAI-CHAO , LIU CUI-HONG
Published: January 2012

The differential cross section (DCS) for exciton-mediated Raman scattering (EMRS) in one-dimensional semiconductor quantum dots is presented. The exciton states are considered as intermediate states in the Raman scattering process. The selection rules for the EMRS process are studied. The numerical results show that the contribution to DCS indicated by exciton is larger than that by electron. DCS of EMRS is larger when there is a bigger confinement potential frequency.
EFFECTS OF NOISE CORRELATION AND TIME DELAY ON TRANSIENT PROPERTIES OF A CANCER GROWTH SYSTEM WITH IMMUNIZATION
Authors: JIA ZHENG-LIN
Published: January 2012

The effects of noise correlation and time delay on the transient properties of a cancer growth system are studied in terms of the mean first-passage time (MFPT), which provides a measure of the mean extinction time of the tumor cell population. The results indicate that the additive and multiplicative noises can induce the noise-enhanced stability (NES) effect. The increasing of the delay time weakens the NES effect in the presence of two noise sources and induces a shift of the maximum of the MFPT towards smaller values of the noise intensities. The increasing of cross-correlation strength between noises can only restrain the NES effect induced by the multiplicative noise and can induce a shift of the peak of the MFPT towards larger values of the noise intensities.
THE EFFECTS OF A FINITE NUMBER OF PARTICLES ON TWO TRAPPED QUANTUM GASES
Authors: CHEN LIWEI , SU GUOZHEN , CHEN JINCAN
Published: January 2012

The effects of a finite number of particles on the thermodynamic properties of ideal Bose and Fermi gases trapped in any-dimensional harmonic potential are investigated. The orders of relative corrections to the thermodynamic quantities due to the finite number of particles are estimated in different situations. The results obtained for the two trapped quantum gases are compared, and consequently, it is shown that the finite-particle-number effects for the condensed Bose gas (a Bose gas with Bose–Einstein Condensation (BEC) occurring in the system) are much more significant than those for the Fermi gas and normal Bose gas (a Bose gas without BEC).
VARIATIONAL CALCULATIONS FOR NORMAL LIQUID 3He AT FINITE TEMPERATURE USING THE SPIN-DEPENDENT CORRELATION FUNCTION
Authors: BORDBAR G. H. , KARIMI M. J.
Published: January 2012

By considering a spin dependence for the correlation function, the thermodynamic properties of normal liquid 3 He have been investigated by employing a lowest order constrained variational approach. It is seen that the spin-singlet state has a smaller contribution in the potential energy of normal liquid 3 He with respect to the spin-triplet state. It is seen that at high temperatures, the free energy of normal liquid 3 He in cases of spin-dependent and spin-independent correlation functions are nearly identical. The equations of state of these two cases are nearly similar too.
EMERGENT TURING PATTERN IN EPIDEMIC SPREADING USING CELLULAR AUTOMATON
Authors: SUN GUI-QUAN , JIN ZHEN , LI LI
Published: January 2012

Spatial epidemiology is the study of spatial variation in disease risk or incidence, including the spatial patterns of the population. Thus, an epidemic model with spatial structure based on the cellular automata method, which is different from deterministic and probabilistic CA models, is investigated. The construction of the cellular automata is based on the work of Bussemaker et al. [Phys. Rev. Lett.78, 5018–5021 (1997)]. For the appropriately chosen parameters, Turing pattern formation can emerge from a randomly perturbed uniform state, which is shown by numerical simulations. The results obtained confirm that diffusion can form the disease being in high density and the population being more stable.
NUMERICAL SOLUTIONS OF WAVE EQUATIONS SUBJECT TO AN INTEGRAL CONSERVATION CONDITION BY HE'S HOMOTOPY PERTURBATION METHOD
Authors: YILDIRIM AHMET , GÜLKANAT YAǦMUR
Published: January 2012

The aim of this paper is to solve one-dimensional wave equations that combine classical and integral boundary conditions using the homotopy perturbation method (HPM). The studied equations are changed into direct problems easy to be handled by the homotopy perturbation method. Several examples are given and the results are compared with exact solutions, revealing effectiveness and simplicity of the method.
NUMERICAL SOLUTIONS FOR THE NONLINEAR FORNBERG–WHITHAM EQUATION BY HE'S METHODS
Authors: ABIDI FAYÇAL , OMRANI KHALED
Published: January 2012

In this paper, variational iteration method (VIM) and homotopy-perturbation method (HPM) are implemented for solving analytically the nonlinear Fornberg–Whitham (FW) equation. VIM is used to construct correction functionals using general Lagrange multipliers identified optimally via the variational theory HPM converts a difficult problem into simple one, which can be easily handled. Furthermore, the solutions obtained are compared with the corresponding exact solution to show the applicability accuracy and efficiency of the present methods in solving a large class of linear and nonlinear problems arising in different fields of science and engineering.
SEARCHING FOR DARK MATTER ISOCURVATURE INITIAL CONDITIONS WITH N-BODY SIMULATIONS
Authors: LIU JIE
Published: January 2012

Small fraction of isocurvature perturbations may exist and correlate with adiabatic perturbations in the primordial perturbations. Naively switching off isocurvature perturbations may lead to biased results. We study the effect of dark matter isocurvature on the structure formation through N-body simulations. From the best-fit values, we run four sets of simulation with different initial conditions and different box sizes. We find that, if the fraction of dark matter isocurvature is small, we cannot detect its signal through matter power spectrum and two-point correlation function with large scale survey. However, the halo mass function can give an obvious signal. Compared to 5% difference on matter power spectrum, it can get 37% at z = 3 on halo mass function. This indicates that future high precise cluster count experiment can give stringent constraints on dark matter isocurvature perturbations.
COMPLETENESS THEOREMS IN THE UNIFORM NORM CONNECTED TO ELLIPTIC EQUATIONS OF HIGHER ORDER WITH CONSTANT COEFFICIENTS
Authors: CIALDEA A.
Published: January 2012

We consider the problem of the completeness of the system [Formula: see text] in [C0(Σ)]m, where {ωk} is a basis of polynomial solutions of the elliptic equation ∑|α|≤2maαDαu = 0, aαare real constants, Σ is the boundary of a bounded domain in ℝnand ∂νdenotes the normal derivative. If E satisfies a Gårding inequality and [Formula: see text] is connected, we show that such a completeness property holds if and only if all the irreducible factors of the characteristic polynomial of the differential operator vanish at the origin. The proof hinges on some jump formulas obtained for general potentials generated by measures.
OPTICAL AND HIGH-TEMPERATURE ELECTRICAL PROPERTIES OF PURE AND Sr-MODIFIED CdS NANOCRYSTALS
Authors: FIRDOUS ARFAT , AHMAD M. M.
Published: January 2012

Nanoparticles of CdS - and Sr -doped CdS were synthesized through chemical precipitation method using a high-boiling solvent. X-ray diffraction confirms the nanocrystallinity of the prepared nanostructures. The mean crystal size obtained by full width half maxima analysis is 3.34 nm for CdS , 3.39 nm for CdS:Sr (2 mM) and 3.41 nm for CdS:Sr (4 mM). The optical absorption analysis conducted in UV-vis range 200–900 nm reveals the transparency of these nanocrystals in the entire visible range but not in ultraviolet range. The results based on optical analysis yield bandgap values as 2.63 eV for CdS , 2.58 eV for CdS:Sr (2 mM) and 2.52 eV for CdS:Sr (4 mM) nanoparticles. This implies that pure CdS - and Sr -doped CdS are blue shifted with respect to the bulk CdS (2.42 eV), however Strontium modified CdS nanocrystals are red shifted with respect to pure CdS nanocrystals. The electrical conductivity data reveals semiconducting behavior of both pure CdS - and Sr -doped CdS nanocrystals. Fitting of conductivity data in Mott's variable range hopping model shows that Strontium doping in CdS reduces gap parameters from 2.81 to 2.59 eV.
LARGE SCALE SYNTHESIS OFAg2SNANOWIRES AND THEIR ELECTRICAL CHARACTERIZATION
Authors: KUMAR VIJAY , KUMAR SANJEEV , CHAKARVARTI S. K.
Published: January 2012

In this paper, large scale synthesis of Ag2S nanowires having diameter 100 nm using chemical reaction is reported. Nanochannels in anodic alumina membrane were utilized as templates. Scanning electron microscopy was used for morphological study of nanowires. X-ray diffraction depicted the monoclinic nature of Ag2S nanowires. Energy dispersive X-ray fluorescence recommended that the nanowires are of pure silver sulfide rather than any silver compound. Nonlinear I–V characteristics were observed for Ag/Ag2S/Ag heterostructures.