bluuebunny/crossref_metadata_2025 huggingface dataset:
Film thickness dependence of the enhanced EuS interface ordering temperature in EuS∕Co thin films
Authors: Volobuev V. V. , Stetsenko A. N. , van Lierop J.
Published: January 2008

The temperature dependent magnetism of EuS(tnm)∕Co(tnm) films, where t=3.5, 5.0, 7.8, and 20nm, reveals two EuS ordering temperatures TC: one magnetic phase order below TC∼16K that corresponds to pure EuS and the other phase order at a TC>200K that has a EuS thickness dependence. This enhanced TC is the result of EuS interface moments exchanged coupled to Co moments in an antiparallel configuration. The interface TC varies with inverse EuS film thickness, a behavior that is consistent with a magnetic proximity effect, and the amount of EuS that orders at the enhanced TC decreases with film thickness, t<10nm.
Status of ionization by radial electron neat adaptation ion source research and development for SPIRAL2 and EURISOL-DS
Authors: Lau C. , Cheikh Mhamed M. , Essabaa S.
Published: January 2008

To take up the challenging issue of supplying a plasma ion source able to produce radioactive beams under extreme SPIRAL2 and EURISOL irradiation conditions, a research and development program has been initiated to work out ionization by radial electron neat adaptation (IRENA) ion source. Based on the electron beam generated plasma concept, the ion source is specifically adapted for thick target exploitation under intense irradiation. A validation prototype has been designed, constructed, and tested. First results obtained will be presented and commented. IRENA potential will be discussed, particularly in the framework of multimegawatt EURISOL.
Anomalous exchange bias behavior in ion-beam bombarded NiCo∕(Ni,Co)O bilayers
Authors: Lin K.-W. , Guo J.-Y. , Liu H.-Y. , Ouyang H. , Chan Y.-L. , Wei D.-H. , van Lierop J.
Published: January 2008

The structural and magnetic properties of NiCo∕(Ni,Co)O bilayers were investigated. X-ray diffractometry results have shown that the top NiCo layer consisted of a fcc NiCo phase. The bilayer bottom was either a pure (Ni,Co)O or a composite [NiCo+(Ni,Co)O] phase, depending on the percent of O2∕Ar ratio used during deposition. A double-shifted hysteresis loop exhibiting components that were from positive or negative coupling was observed in the NiCo∕(Ni,Co)O (8%O2∕Ar) bilayers. The microstructural changes, which result from a combination of deposition oxygen content and the ion-beam bombardment, will result in the unusual exchange bias behavior.
Long-period gratings inscribed in air- and water-filled photonic crystal fiber for refractometric sensing of aqueous solution
Authors: He Zonghu , Zhu Yinian , Du Henry
Published: January 2008

We report a comparative study of inscription of long-period gratings (LPGs) in air- and water-filled photonic crystal fiber (PCF) via residual stress relaxation using a scanning CO2 laser for refractometric sensing. Under the same inscribing condition, LPGs fabricated following the two PCF schemes exhibit different resonance spectral features. Using NaCl aqueous solution of various concentrations, we demonstrate that both PCF-LPGs possess excellent sensitivity of ∼10−7 refractive index unit within the index range of 1.33 and 1.35, whereas LPGs inscribed in water-filled PCF show much narrower full width at half maximum in the resonance spectrum.
Influence of disorder on the in-field Jc of MgB2 wires using highly active pyrene
Authors: Kim J. H. , Xu X. , Hossain M. S. A. , Shi D. Q. , Zhao Y. , Wang X. L. , Dou S. X. , Choi S. , Kiyoshi T.
Published: January 2008

In this work, we report on significantly enhanced critical current density (Jc) in MgB2 superconductor that was easily obtained by doping with a hydrocarbon, highly active pyrene (C16H10), and using a sintering temperature as low as ∼600°C. The processing advantages of the C16H10 additive include production of a highly active carbon (C) source, an increased level of disorder, and the introduction of small grain size, resulting in enhancement of Jc.
Local tuning of photonic crystal cavities using chalcogenide glasses
Authors: Faraon Andrei , Englund Dirk , Bulla Douglas , Luther-Davies Barry , Eggleton Benjamin J. , Stoltz Nick , Petroff Pierre , Vučković Jelena
Published: January 2008

We demonstrate a method to locally change the refractive index in planar optical devices by photodarkening of a thin chalcogenide glass layer deposited on top of the device. The method is used to tune the resonance of GaAs-based photonic crystal cavities by up to 3nm at 940nm. The method has broad applications for postproduction tuning of photonic devices.
Sensitivity enhancement in diaphragms made by aluminum nitride thin films prepared on polyimide films
Authors: Akiyama Morito , Morofuji Yukari , Nishikubo Keiko , Kamohara Toshihiro
Published: January 2008

The authors have investigated a combination of high and low modulus materials in diaphragms for high sensitivity response. High and low modulus materials are aluminum nitride (AlN) thin films and polyimide films, respectively. AlN was sputtered deposited. The AlN films consist of columnar crystal grains and indicate c-axis orientation. The diaphragm indicates a high sensitivity response of 37200pC∕N, although the piezoelectric coefficient d33 of the AlN film is 2.6pC∕N. The sensitivity response is fifty times as high as that of diaphragms consisted of AlN films and superalloy foils.
Enhancement of ZnO light emission via coupling with localized surface plasmon of Ag island film
Authors: Cheng Peihong , Li Dongsheng , Yuan Zhizhong , Chen Peiliang , Yang Deren
Published: January 2008

Enhancement of the light emission of ZnO films was observed by coupling through localized surface plasmons. By sputtering Ag islands onto ZnO films, their band gap emission coming through the Ag island films was enhanced by threefolds, while the defect emission was quenched. The enhancement was found to be mainly dependent on the sputtering time of the Ag islands, which is related to the island size. Furthermore, the relative spectral position between the ZnO emission band and the localized surface plasmon resonance bands of Ag islands was found to be decisive for the enhancement or quenching of photoluminescence, indicating that the emission intensity of ZnO films can be controlled by the Ag island size and the localized surface plasmon resonance band position.
Behavior of n-ZnO nanorods/p-Si heterojunction devices at higher temperatures
Authors: Koteeswara Reddy N. , Ahsanulhaq Q. , Kim J. H. , Hahn Y. B.
Published: January 2008

This work explores the temperature dependent heterojunction behavior of n-type zinc oxide (ZnO) nanorods/ZnO∕p-Si diodes. The as-grown ZnO nanorod structures on ZnO coated p-Si substrates are single crystalline and grown along the [001] direction. The p-n diode showed an excellent stability over the temperature range of 20–150°C due to highly doped p-type Si substrate. The turn-on and breakdown voltage of the device slightly decreased with an increase of temperature whereas the saturation current of the device increased from 0.42to0.67μA. The device behavior at different temperatures in forward as well as reverse biased conditions are studied and reported.
Formation of two conjoint fivefold deformation twins in copper nanowires with molecular dynamics simulation
Authors: Zheng Y. G. , Zhang H. W. , Chen Z. , Wang L. , Zhang Z. Q. , Wang J. B.
Published: January 2008

The formation of two conjoint fivefold deformation twins (DTs) in copper nanowires under bending is reported based on molecular dynamics simulations. It is found that an intermediate icosahedral phase is formed to facilitate the transformation from a low dense (010) plane in a face-centered-cubic lattice to a {111} close-packed fashion, forming trijunctions composed of three DTs. These trijunctions can easily interact with other DTs, forming two conjoint fivefold DTs. This formation process differs from the one observed by Cao and Wei [Appl. Phys. Lett. 89, 041919 (2006)], that is, fivefold DTs could be formed without introducing initial imperfections in simulations.
Increasing the length of single-wall carbon nanotubes in a magnetically enhanced arc discharge
Authors: Keidar Michael , Levchenko Igor , Arbel Tamir , Alexander Myriam , Waas Anthony M. , Ostrikov Kostya (Ken)
Published: January 2008

It is demonstrated that a magnetic field has a profound effect on the length of a single-wall carbon nanotube (SWCNT) synthesized in the arc discharge. The average length of SWCNT increases by a factor of 2 in discharge with magnetic field as compared with the discharge without magnetic field, and the yield of long nanotubes with lengths above 5μm also increases. A model of SWCNT growth on metal catalyst in arc plasma was developed. Monte-Carlo simulations confirm that the increase of the plasma density in the magnetic field leads to an increase in the nanotube growth rate and thus leads to longer nanotubes.
Valence band offset of MgO∕InN heterojunction measured by x-ray photoelectron spectroscopy
Authors: Zhang P. F. , Liu X. L. , Zhang R. Q. , Fan H. B. , Song H. P. , Wei H. Y. , Jiao C. M. , Yang S. Y. , Zhu Q. S. , Wang Z. G.
Published: January 2008

MgO may be a promising gate dielectric and surface passivation film for InN based devices and the valence band offset of MgO∕InN heterojunction has been measured by x-ray photoelectron spectroscopy. The valence band offset is determined to be 1.59±0.23eV. Given the experimental band gap of 7.83 for the MgO, a type-I heterojunction with a conduction band offset of 5.54±0.23eV is found. The accurate determination of the valence and conduction band offsets is important for use of MgO∕InN electronic devices.
Room temperature contactless electroreflectance of the ground and excited state transitions in Ga0.76In0.24As0.08Sb0.92∕GaSb single quantum wells of various widths
Authors: Kudrawiec R. , Motyka M. , Misiewicz J. , Hümmer M. , Rößner K. , Lehnhardt T. , Müller M. , Forchel A.
Published: January 2008

The optical transitions in Ga0.76In0.24As0.08Sb0.92∕GaSb quantum wells with the width varying from 10to21nm were studied by room temperature contactless electroreflectance (CER). In addition to the quantum well (QW) ground state transition (11H), the 22H and 33H transitions (where klH denotes transition between the kth heavy hole and the lth electron subbands) have been clearly observed in CER spectra. The experimental QW transition energies were compared with theoretical predictions based on an effective mass formalism model. It has been concluded that this QW is type I for both electron and holes and the conduction band offset for the unstrained Ga0.76In0.24As0.08Sb0.92∕GaSb interface equals ∼90%.
Molecular dynamics simulations of the torsional instability of carbon nanotubes filled with hydrogen or silicon atoms
Authors: Wang Q. , Liew K. M. , Varadan V. K.
Published: January 2008

Torsional buckling of single-walled carbon nanotubes filled with hydrogen or silicon atoms via molecular dynamics is reported. The formation of a concentric layered atomic cluster in the tubes with the half filled atoms is observed at a lower torsional angle. However, a spill-over phenomenon accompanied by torsional buckling is found at a higher torsional angle that reveals the effect that being fully filled with hydrogen and silicon atoms has on the stability of carbon nanotubes. The higher critical torsional angle of carbon nanotubes fully filled with foreign atoms is attributed to the extra energy necessary to break the atomic chain structure.
The influence of substrate polarity on the structural quality of InN layers grown by high-pressure chemical vapor deposition
Authors: Dietz N. , Alevli M. , Atalay R. , Durkaya G. , Collazo R. , Tweedie J. , Mita S. , Sitar Z.
Published: January 2008

The influence of substrate polarity on the properties of InN layers grown by high-pressure chemical vapor deposition has been studied. The 2Θ-ω x-ray diffraction scans on InN layers deposited on polar GaN epilayers revealed single-phase InN(0002) with a full width at half maximum (FWHM) of around 200arcsec. InN layers grown on N-polar GaN exhibit larger FWHMs. Rocking curve analysis confirmed single-phase InN for both growth polarities, with FWHM values for ω-RC(002) at 2080arcsec for InN grown on Ga-polar templates. The A1(LO) Raman mode analysis shows higher free carrier concentrations in InN grown on N-polar templates, indicating that polarity affects the incorporation of impurities.
Covalent capture of kinase-specific phosphopeptides reveals Cdk1-cyclin B substrates
Authors: Blethrow Justin D. , Glavy Joseph S. , Morgan David O. , Shokat Kevan M.
Published: January 2008

We describe a method for rapid identification of protein kinase substrates. Cdk1 was engineered to accept an ATP analog that allows it to uniquely label its substrates with a bio-orthogonal phosphate analog tag. A highly specific, covalent capture-and-release methodology was developed for rapid purification of tagged peptides derived from labeled substrate proteins. Application of this approach to the discovery of Cdk1-cyclin B substrates yielded identification of >70 substrates and phosphorylation sites. Many of these sites are known to be phosphorylated
in vivo
, but most of the proteins have not been characterized as Cdk1-cyclin B substrates. This approach has the potential to expand our understanding of kinase–substrate connections in signaling networks.
Enterococcus faecalis
from newborn babies regulate endogenous PPARγ activity and IL-10 levels in colonic epithelial cells
Authors: Are Alexandra , Aronsson Linda , Wang Shugui , Greicius Gediminas , Lee Yuan Kun , Gustafsson Jan-Åke , Pettersson Sven , Arulampalam Velmurugesan
Published: January 2008

The postembryonic development of the gastrointestinal tract is subject to regulation by the colonizing microbiota. This maturation process requires the commensal bacteria to cross-talk with host cells by way of recognizing receptors and inducing signaling pathways to activate transcription factors such as the nuclear receptors. Here, we show that in colonic cell lines and in primary colonic cells,
Enterococcus faecalis
isolated from newborn babies possess the ability to regulate peroxisome proliferator-activated receptor-γ1 (PPARγ1) activity through phosphorylation. This results in elevated DNA binding and transcriptional activation of downstream target genes, including IL-10, a cytokine known to modulate innate immune function. Furthermore, phosphorylation appears tightly regulated as phospho-PPARγ1 becomes an immediate substrate for degradation possibly to curtail any extended transactivation. The involvement of PPARγ1 in a myriad of physiological processes further confirms that microflora-driven regulation might be important for a number of homeostatic strategies in the gut.
Extended self-similarity of intermittent turbulence in edge magnetized plasmas
Authors: Budaev V.P. , Ohno N. , Masuzaki S. , Morisaki T. , Komori A. , Takamura S.
Published: January 2008

We investigate the intermittency of the edge plasma turbulence in the T-10 tokamak, the Large Helical Device, the linear machine NAGDIS-II and the HYBTOK-II tokamak. The higher order structure functions are analysed to characterize the self-similarity of the plasma intermittency. The generalized scale invariance over three decades of time scales is observed by involving the extended self-similarity hypothesis. Turbulent fluctuations demonstrate multifractal statistics. The structure function scalings deviate strongly from Kolmogorov's K41 model prediction. The high-order structure functions have a nonlinear scaling being a nonlinear function of the order index. The nonlinear scaling is interpreted within the framework of the log-Poisson model considering ‘hidden’ statistical symmetry (dilatation group), hierarchy of moments, a generalized scale covariance and an underlying multifractal multiplicative cascading process.
Characterization of local turbulence in magnetic confinement devices
Authors: Rajković Milan , Škorić Miloš , Sølna Knut , Antar Ghassan
Published: January 2008

A multifractal analysis based on evaluation and interpretation of large deviation spectra is applied to plasma edge turbulence data from different devices (MAST and Tore Supra). It is demonstrated that in spite of some universal features there are unique characteristics for each device as well as for different confinement regimes. In the second part of the exposition the issue of estimating the variable power law behavior of spectral densities is addressed. The analysis of this issue is performed using fractional Brownian motion (fBm) as the underlying stochastic model whose parameters are estimated locally in time by wavelet scale spectra. In this manner information about the inertial range as well as variability of the fBm parameters is obtained giving more information important for understanding edge turbulence and intermittency.
Chaotic transport in reversed shear tokamaks
Authors: Marcus F.A. , Kroetz T. , Roberto M. , Caldas I.L. , da Silva E.C. , Viana R.L. , Guimarães-Filho Z.O.
Published: January 2008

For tokamak models using simplified geometries and reversed shear plasma profiles, we have numerically investigated how the onset of Lagrangian chaos at the plasma edge may affect the plasma confinement in two distinct but closely related problems. Firstly, we have considered the motion of particles in drift waves in the presence of an equilibrium radial electric field with shear. We have shown that the radial particle transport caused by this motion is selective in phase space, being determined by the resonant drift waves and depending on the parameters of both the resonant waves and the electric field profile. Moreover, we have shown that an additional transport barrier may be created at the plasma edge by increasing the electric field. In the second place, we have studied escape patterns and magnetic footprints of chaotic magnetic field lines in the region near a tokamak wall, when there are resonant modes due to the action of an ergodic magnetic limiter. A non-monotonic safety factor profile has been used in the analysis of field line topology in a region of negative magnetic shear. We have observed that, if internal modes are perturbed, the distributions of field line connection lengths and magnetic footprints exhibit spatially localized escape channels. For typical physical parameters of a fusion plasma, the two Lagrangian chaotic processes considered in this work can be effective in usual conditions so as to influence plasma confinement. The reversed shear effects discussed in this work may also contribute to evaluate the transport barrier relevance in advanced confinement scenarios in future tokamak experiments.
Prevalence, abundance, and distribution of Lepeoptheirus salmonis (Krøyer, 1837) and Caligus elongatus (Nordmann, 1832) on wild sea trout Salmo trutta L.
Authors: Urquhart K. , Pert C. C. , Kilburn R. , Fryer R. J. , Bricknell I. R.
Published: January 2008

Urquhart, K., Pert, C. C., Kilburn, R., Fryer, R. J., and Bricknell, I. R. 2008. Prevalence, abundance, and distribution of Lepeoptheirus salmonis (Krøyer, 1837) and Caligus elongatus (Nordmann, 1832) on wild sea trout Salmo trutta L. – ICES Journal of Marine Science, 65: 171–173. Lepeophtheirus salmonis (Krøyer, 1837) and Caligus elongatus (Nordmann, 1832) were found on 100% and 90%, respectively, of 30 wild sea trout from the east coast of Scotland. Mean abundances of the same two sea lice were 7.8 and 7.7, respectively. The distribution of the two species of sea louse differed, however, with a greater proportion of L. salmonis in the posterior and anterior dorsal regions, and a greater proportion of C. elongatus in the caudal and posterior ventral regions.
Microsatellite markers discriminate three species of North Atlantic wolffishes (Anarhichas spp.)
Authors: McCusker M. R. , Paterson I. G. , Bentzen P.
Published: January 2008

Sixteen tetranucleotide and dinucleotide microsatellite markers were isolated from Atlantic wolffish, Anarhichas lupus, following a microsatellite enrichment procedure using probe‐labelled magnetic beads. These microsatellites were intended for use in Atlantic wolffish as well as in two closely related species, spotted wolffish, Anarhichas minor, and northern wolffish, Anarhichas denticulatus. As all three species are of conservation concern in Canadian waters and as forensic wildlife cases may arise for this genus, microsatellite markers were assessed to determine how well they differentiate these species from one another and to estimate probability values that could be expected for identification of individuals to species.
Mitochondrial DNA evidence for high levels of gene flow among populations of a widely distributed anadromous lamprey Entosphenus tridentatus (Petromyzontidae)
Authors: Goodman D. H. , Reid S. B. , Docker M. F. , Haas G. R. , Kinziger A. P.
Published: January 2008

Mitochondrial DNA variation among 1246 individuals of Pacific lamprey (Entosphenus tridentatus) from 81 populations spanning 2600 km from the Skeena River, British Columbia, to the Ventura River, California, was surveyed using five restriction enzymes. A total of 29 composite haplotypes was detected in two gene fragments (ND2 and ND5). The three most common haplotypes, occurring in 91% of all samples, were present at similar frequencies in all regions. Samples were divided into six biogeographic regions based on sample distribution and geographical landmarks to assess geographic genetic structure. Analysis of molecular variance indicated that 99% of the genetic variation was explained by variability within drainages. The lack of geographical population structure is likely related to a life‐history pattern that includes a prolonged larval freshwater stage, migration to oceanic feeding and return to fresh water to spawn. The lack of strong natal homing apparently promotes gene flow among drainages and regions.
History repeated: recent and historical mitochondrial introgression between the current darter Etheostoma uniporum and rainbow darter Etheostoma caeruleum (Teleostei: Percidae)
Authors: Ray J. M. , Lang N. J. , Wood R. M. , Mayden R. L.
Published: January 2008

Incongruence between recognized taxonomy and phylogenetic relationships between two species from a diverse clade (Percidae: Etheostomatinae) of stream fishes was found in a mitochondrial (mt) DNA gene tree. Two darters in subgenus Oligocephalus, Etheostoma uniporum current darter and Etheostoma caeruleum rainbow darter were sampled throughout their sympatric distribution in the Ozark Highlands of the central United States. Sequences from cytochrome (cyt) b and the first intron of the nuclear marker S7 were analysed separately using maximum parsimony and Bayesian methods. Cyt b recovered both species as polyphyletic; E. uniporum haplotypes were interspersed within E. caeruleum. However, both species were monophyletic and non‐sister taxa based on S7. The cyt b gene tree pattern is caused by introgressive hybridization resulting in the mtDNA replacement of E. uniporum haplotypes by those of E. caeruleum. Some E. uniporum haplotypes are shared with geographically proximate E. caeruleum, and this is consistent with recent hybridization, while other E. uniporum haplotypes indicate historical sorting of introgressed lineages. The mechanism of introgression is likely asymmetric sneaking behaviour by male E. uniporum, a mating tactic observed in related species. MtDNA replacement may have occurred in E. uniporum due to drift fixation in a historically small female effective population. Additional evidence for darter hybridization will likely be discovered in future molecular genetic surveys of the nearly 200 species in eastern North America.
Genetic differentiation in pointing dog breeds inferred from microsatellites and mitochondrial DNA sequence
Authors: Parra D. , Méndez S. , Cañón J. , Dunner S.
Published: January 2008

Recent studies presenting genetic analysis of dog breeds do not focus specifically on genetic relationships among pointing dog breeds, although hunting was among the first traits of interest when dogs were domesticated. This report compares histories with genetic relationships among five modern breeds of pointing dogs (English Setter, English Pointer, Epagneul Breton, Deutsch Drahthaar and German Shorthaired Pointer) collected in Spain using mitochondrial, autosomal and Y‐chromosome information. We identified 236 alleles in autosomal microsatellites, four Y‐chromosome haplotypes and 18 mitochondrial haplotypes. Average FST values were 11.2, 14.4 and 13.1 for autosomal, Y‐chromosome microsatellite markers and mtDNA sequence respectively, reflecting relatively high genetic differentiation among breeds. The high gene diversity observed in the pointing breeds (61.7–68.2) suggests contributions from genetically different individuals, but that these individuals originated from the same ancestors. The modern English Setter, thought to have arisen from the Old Spanish Pointer, was the first breed to cluster independently when using autosomal markers and seems to share a common maternal origin with the English Pointer and German Shorthaired Pointer, either via common domestic breed females in the British Isles or through the Old Spanish Pointer females taken to the British Isles in the 14th and 16th centuries. Analysis of mitochondrial DNA sequence indicates the isolation of the Epagneul Breton, which has been formally documented, and shows Deutsch Drahthaar as the result of crossing the German Shorthaired Pointer with other breeds. Our molecular data are consistent with historical documents.
Clonal diversity and genealogical relationships of gibel carp in four hatcheries
Authors: Li F.‐B. , Gui J.‐F.
Published: January 2008

To conserve and utilize the genetic pool of gynogenetic gibel carp (Carassius auratus gibelio), the Fangzheng and Qihe stock hatcheries have been established in China. However, little information is available on the amount of genetic variation within and between these populations. In this study, clonal diversity in 101 fish from these two stock hatcheries and 35 fish from two other hatcheries in Wuhan and Pengze respectively was analysed for variation in serum transferrin. Thirteen clones were found in Fangzheng and Qihe, of which 12 were novel. Six clones were specific to Fangzheng and three specific to Qihe, whereas four were shared among the Fangzheng and Qihe fish. To obtain more knowledge on genetic diversity and genealogical relationships within gibel carp, the complete mitochondrial DNA (mtDNA) control region (∼920 bp) was sequenced in 64 individuals representing all 14 clones identified in the four hatcheries. Differences in the mtDNA sequences varied remarkably among hatcheries, with the Fangzheng and Qihe lines demonstrating high diversity and Wuhan and Pengze showing no variation. The Fangzheng and Qihe lines might represent two distinct matrilineal sources. One of the Qihe samples carried the haplotype shared by a most widely cultivated Fangzheng clone, indicating that a Fangzheng clone escaped from cultivated ponds and moved into the Qihe hatchery. Four Fangzheng samples clustered within the lineage formed mainly by Qihe samples, most likely reflecting historical gene flow from Qihe to Fangzheng. It is suggested that clones in Wuhan originated from Fangzheng, consistent with their introduction history, supporting the hypothesis that gibel carp in Pengze were domesticated from individuals in the Fangzheng hatchery.
Fine‐mapping of a marbling trait to a 2.9‐cM region on bovine chromosome 7 in Japanese Black cattle
Authors: Hirano T. , Watanabe T. , Inoue K. , Sugimoto Y.
Published: January 2008

To locate quantitative trait loci (QTL) for intramuscular fat deposition (marbling) in a local population of Japanese Black cattle, we performed a genome scan using a paternal half‐sib family of Bull A. A marbling QTL was mapped in the region flanked by DIK0079 (20.7 cM) and TGLA303 (39.3 cM) on bovine chromosome (BTA) 7, affecting 5.0% of the total family variance. Haplotype analysis of the QTL region revealed that the marbling‐increasing Q allele was transmitted from the dam. On the other hand, Bull B, a maternal half‐sib of Bull A, did not receive the Q allele from its dam, based on the following findings: (i) a marbling QTL on BTA7 was not detected in the Bull B paternal half‐sib family; (ii) recombination between DIK0079 (20.7 cM) and RM006 (25.4 cM) in the QTL region was observed in the maternal chromosome of Bull B; and (iii) the Q‐harbouring steers from Bull A exhibited significantly higher marbling than the steers from Bull B and the remaining steers from Bull A. To precisely compare the maternal chromosomes of both bulls, we constructed a bacterial artificial chromosome contig covering the region between DIK0079 and RM006 and developed DNA markers. The recombination occurred between DIK8042 and DIK8044, indicating that the marbling QTL was in a 2.9‐cM region flanked by DIK0079 and DIK8044.
DNA polymorphisms in bovine fatty acid synthase are associated with beef fatty acid composition1
Authors: Zhang S. , Knight T. J. , Reecy J. M. , Beitz D. C.
Published: January 2008

The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the thioesterase (TE) domain of the bovine fatty acid synthase (FASN) gene and to evaluate the extent to which they were associated with beef fatty acid composition. The four exons in FASN that encode for the TE domain were sequenced, and three SNPs, AF285607:g.17924A>G, g.18663T>C and g.18727C>T, were identified. Purebred Angus bulls (n = 331) were classified into three genotype groups, g.17924AA (n = 121), g.17924AG (n = 168) and g.17924GG (n = 42). The g.17924A>G genotype was significantly associated with fatty acid composition of longissimus dorsi muscle of Angus bulls. Cattle with the g.17924GG genotype had lower myristic acid (C14:0; P < 0.0001), palmitic acid (C16:0, P < 0.05) and total saturated fatty acid contents (P < 0.01), greater health index (P < 0.001), oleic acid content (C18:1; P < 0.001) and total monounsaturated fatty acid concentration (P < 0.01) in the total lipids and triacylglycerols fraction than did those with the g.17924AA genotype. Because of the linkage disequilibrium between SNPs g.17924A>G and g.18663T>C, similar significant associations of fatty acid contents with the g.18663T>C genotypes were observed. In conclusion, the SNPs g.17924A>G and g.18663T>C may be used as DNA markers to select breeding stock that have a healthier fatty acid composition.
Detection of quantitative trait loci for meat quality traits in cattle
Authors: Gutiérrez‐Gil B. , Wiener P. , Nute G. R. , Burton D. , Gill J. L. , Wood J. D. , Williams J. L.
Published: January 2008

A whole‐genome scan was carried out to detect quantitative trait loci (QTL) affecting sensory, organoleptic, physical and chemical properties of meat. The study used phenotypic data from 235 second‐generation cross‐bred bull calves of a Charolais × Holstein experimental population. Loin muscle samples were evaluated for yield force, intramuscular fat and nitrogen contents, myofibrillar fragmentation index, haem pigment concentration, moisture content and pH at 24 h postmortem. A sensory assessment was performed on grilled loin and roasted silverside joints by trained panellists. A linear regression analysis based on 165 markers revealed 35 QTL at the 5% chromosome‐wide significance level (20 for sensory traits and 15 for physical and chemical traits), five of which were highly significant (F‐value: ≥9). The most significant QTL was located on chromosome 6 (with the best likely position at 39 cM) and affected haem pigment concentration. The Holstein allele for this QTL was associated with an increase of 0.53 SD in the haem scores. A QTL for pH24h was identified on chromosome 14 (at 40 cM) and a QTL for moisture content was identified on chromosome 22 (at 21 cM). Two highly significant QTL were identified for sensory panel‐assessed traits: beef odour intensity (grilled sample) on chromosome 10 (at 119 cM), and juiciness (roast sample) on chromosome 16 (at 70 cM). The proportion of phenotypic variance explained by the significant QTL ranged from 3.6% (for nitrogen content on chromosome 10) to 9.5% (for juiciness, roast sample on chromosome 16).
The origin of selection signatures on bovine chromosome 6
Authors: Hayes B. J. , Lien S. , Nilsen H. , Olsen H. G. , Berg P. , Maceachern S. , Potter S. , Meuwissen T. H. E.
Published: January 2008

The extent and pattern of linkage disequilibrium (LD) between closely spaced markers contain information about population history, including past population size and selection history. Selection signatures can be identified by comparing the LD surrounding a putative selected allele at a locus to the putative non‐selected allele. In livestock populations, locations of selection signatures identified in this way should be correlated with QTL affecting production traits, as the populations have been under strong artificial selection for these traits. We used a dense SNP map of bovine chromosome 6 to characterize the pattern of LD on this chromosome in Norwegian Red cattle, a breed which has been strongly selected for milk production. The pattern of LD was generally consistent with strong selection in regions containing QTL affecting milk production traits, including a strong selection signature in a region containing a mutation known to affect milk production. The results demonstrate that in livestock populations, the origin of selection signatures will often be QTL for livestock production traits, and illustrate the value of selection signatures in uncovering new mutations with potential effects on quantitative traits.
Polymorphisms in the promoter region of the porcine antiviral MX1 and MX2 genes
Authors: Tungtrakoolsub P. , Noda T. , Morozumi T. , Hamasima N. , Kobayashi E. , Ueda J. , Watanabe T.
Published: January 2008

The porcine MX1 and MX2 promoters were characterized in this study. Sequencing of the 332‐bp MX1 promoter region identified 15 substitutions and insertions at three positions in 21 pigs from 15 breeds, in which nine genotypes were classified. Among the nine genotypes, no statistically significant differences in the promoter activities were observed after interferon (IFN‐α 2b) treatment of transiently transfected cells containing constructs with luciferase reporter plasmids. The 341‐bp MX2 promoter region contained regulatory sequences for ISRE, GC box, Sp1 and AP‐1, as well as a TATA box. Nucleotide sequences of the MX2 promoter region revealed four substitutions and one deletion, in which six genotypes were classified. Among the six genotypes, a statistically significant difference (P < 0.05) in MX2 promoter activities after IFN‐α 2b treatment was detected in transiently transfected cells.
High genetic divergence in miniature breeds of Japanese native chickens compared to Red Junglefowl, as revealed by microsatellite analysis
Authors: Tadano R. , Nishibori M. , Imamura Y. , Matsuzaki M. , Kinoshita K. , Mizutani M. , Namikawa T. , Tsudzuki M.
Published: January 2008

A wide diversity of domesticated chicken breeds exist due to artificial selection on the basis of human interests. Miniature variants (bantams) are eminently illustrative of the large changes from ancestral junglefowls. In this report, the genetic characterization of seven Japanese miniature chicken breeds and varieties, together with institute‐kept Red Junglefowl, was conducted by means of typing 40 microsatellites located on 21 autosomes. We drew focus to genetic differentiation between the miniature chicken breeds and Red Junglefowl in particular. A total of 305 alleles were identified: 27 of these alleles (8.9%) were unique to the Red Junglefowl with high frequencies (>20%). Significantly high genetic differences (FST) were obtained between Red Junglefowl and all other breeds with a range of 0.3901–0.5128. Individual clustering (constructed from combinations of the proportion of shared alleles and the neighbour‐joining method) indicated high genetic divergence among breeds including Red Junglefowl. There were also individual assignments on the basis of the Bayesian and distance‐based approaches. The microsatellite differences in the miniature chicken breeds compared to the presumed wild ancestor reflected the phenotypic diversity among them, indicating that each of these miniature chicken breeds is a unique gene pool.
Effect of CYP2C19 *2 and *17 mutations on pharmacodynamics and kinetics of proton pump inhibitors in Caucasians
Authors: Hunfeld Nicole G. , Mathot Ron A. , Touw Daan J. , Van Schaik Ron H. , Mulder Paul G. , Franck Paul F. , Kuipers Ernst J. , Geus William P.
Published: January 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The influence of CYP2C19 on the kinetics and dynamics of omeprazole, lansoprazole and rabeprazole has been studied in Japanese subjects.

• It has been suggested that subjects with *1/*1 genotype might need stronger acid suppression than *1/*2 and *2/*2 subjects. This suggestion comes from data in Japanese subjects and has not been confirmed in Caucasians.

• Furthermore, a novel CYP2C19 mutation, *17, which mainly occurs in Caucasians has been discovered. This mutation has been associated with clinical failure, but its relevance for therapy with PPIs has not been studied yet.

WHAT THIS STUDY ADDS

• In this study, the influence of CYP2C19 on both the pharmacokinetics and dynamics in Caucasian subjects after single and repeated dosing has been investigated.

• This is the first study showing that Caucasian subjects with *1/*1 and *1/*17 mutations need stronger acid‐inhibition. In this study three proton pump inhibitors (omeprazole, lansoprazole and pantoprazole, in different doses) were studied of which pantoprazole had not been studied before in this setting, not even in Japanese.

AIMS

To investigate the impact of CYP2C19 mutations *2‐*6 and *17 on acid‐inhibition and pharmacokinetics of lansoprazole (L15), omeprazole (O10, O20) and pantoprazole (P40) in Caucasians.

METHODS

CYP2C19 genotyping for *2–*6 and *17 mutations was assessed in subjects who were H. pylori negative in two randomized crossover trials. The influence of CYP2C19 mutations on single and repeated administration of L15 and O10 (study A) and O20 and P40 (study B) was investigated. Pharmacokinetics and the cumulative percentage of time with intragastric pH above 4 (% > pH 4) were assessed on day 1 and 6.

RESULTS

For study A CYP2C19 genotyping found five *1/*1, four *1/*2, one *1/*17 and one *2/*17. For study B the results were six *1/*1, two *1/*2, six *1/*17, one *2/*2 and one *2/*17. For all PPIs AUC was highest in *2/*2 and lowest in *1/*17. On day 1, all PPIs significantly increased percentage >pH 4 compared with baseline. *1/*1 genotype showed no significant acid‐inhibition after L15, O10 and O20. *1/*17 genotype showed no significant acid‐inhibition after O20 and P40. *1/*2 genotype showed significant acid‐inhibition after L15 and O10. On day 6, all four PPIs showed significantly increased acid‐inhibition. *1/*1 and *1/*17 showed a significantly increased percentage > pH 4 after treatment with O20 and P40. However, in *1/*1 subjects percentage > pH 4 was not significantly increased after L15 and O10. *1/*2 genotype showed a significant acid‐inhibitory effect after repeated dosing with L15 and O10.

CONCLUSIONS

Caucasian subjects with *1/*1 and *1/*17 genotype need stronger acid‐suppression therapy, especially during the first days of treatment or with on‐demand therapy.
Liver dysfunction in Turner's syndrome: prevalence, natural history and effect of exogenous oestrogen
Authors: Koulouri Olympia , Ostberg Julia , Conway Gerard S.
Published: January 2008

Objectives  Raised liver enzymes are a common feature of Turner's syndrome (TS), but the cause remains unclear. We studied the hepatic function in a large cohort of women with TS and tested the effect of increasing doses of hormone replacement therapy (HRT) on liver function tests (LFTs).

Design and patients  LFTs were assessed in three studies. A cross‐sectional review of liver function of 125 women (median age: 31 years), a longitudinal study of 30 women (mean follow‐up period: 8 years) and a dose–response study of 14 women with TS and 11 controls with hypogonadism, who received oral 17‐β‐oestradiol (E2) 1, 2 and 4 mg daily in a cyclical formulation for 12 weeks each.

Measurements  Clinical features, oestrogen use and metabolic parameters were compared to liver enzymes (γ‐glutamyl transferase (GGT), alanine aminotransferase (ALT) and alkaline phosphatase (ALP)), albumin and bilirubin. LFTs were also measured during each treatment interval of the dose–response study. Hepatic autoimmunity was sought in the cross‐sectional study.

Results  When compared to the control population, as opposed to reference ranges, 91% of women with TS demonstrated liver enzyme elevation, with a yearly incidence of 2·1%. LFTs correlated positively with cholesterol (P < 0·001), BMI (P = 0·004) and type of oestrogen therapy (P = 0·04). Increasing doses of HRT resulted in a significant decrease in GGT, ALT, bilirubin and albumin. No evidence of excessive hepatic autoimmunity was found.

Conclusion  The prevalence of raised liver enzymes in TS may have been underestimated by the use of reference ranges rather than matched controls. Obesity and hyperlipidaemia are associated with raised LFTs, as well as the use of HRT compared to the oral contraceptive pill (OCP). Exogenous oestrogen both as OCP and HRT improves liver function. Liver dysfunction in TS is likely to be a form of hepatic steatosis and intervention trials are now indicated.
Alteration of ghrelin–neuropeptide Y network in obese patients with polycystic ovary syndrome: role of hyperinsulinism
Authors: Romualdi Daniela , De Marinis Laura , Campagna Giuseppe , Proto Caterina , Lanzone Antonio , Guido Maurizio
Published: January 2008

Objective  Insulin, ghrelin, neuropeptide Y (NPY) and leptin interact in the regulation of energy homeostasis. Most of these signals are altered in polycystic ovary syndrome (PCOS), which is characterized by a high prevalence of obesity. The present study was conducted to evaluate ghrelin–NPY and ghrelin–leptin interplays in relation to insulin secretion in obese PCOS subjects.

Design  Pilot prospective study.

Patients  Seven obese PCOS women and seven age–weight matched controls.

Measurements  Hormonal measurements, oral glucose tolerance test (OGTT) and a ghrelin test (1 µg/kg i.v. bolus). PCOS patients repeated the clinical work‐up after 4 months of metformin treatment (1500 mg/day orally).

Results  At baseline, PCOS women showed a significantly higher insulinaemic response to the OGTT compared to controls (P < 0·05). In basal conditions, PCOS women exhibited lower NPY levels than controls (P < 0·01). Ghrelin injection markedly increased NPY in controls (P < 0·01), whereas PCOS women showed a deeply blunted NPY response to the stimulus (area under the curve – AUC–NPY: P < 0·01 vs. controls.). Metformin treatment induced a significant decrease in insulin levels (P < 0·01) and the concomitant recovery of NPY secretory capacity in response to ghrelin (AUC–NPY: P < 0·05 vs. baseline) in PCOS women. Leptin levels, which were similar in the two groups, were not modified by ghrelin injection; metformin did not affect this pattern.

Conclusion  Hyperinsulinaemia seems to play a pivotal role in the alteration of NPY response to ghrelin in obese PCOS women. This derangement could be implicated in the physiopatology of obesity in these patients.
Fine needle aspiration at a Regional Head and Neck Clinic: A clinically beneficial and cost‐effective service
Authors: O’Donnell M. E. , Salem A. , Badger S. A. , Sharif M. A. , Kamalapurkar D. , Lieo T. , Spence R. A. J.
Published: January 2008

Background:  Fine needle aspiration (FNA) is an important adjuvant to the diagnosis of a palpable lesion which often permits the complete assessment of patients. The main objective of this study was to determine the clinical benefit of a dedicated FNA service at a tertiary referral Head and Neck Clinic and to assess if such a service is cost effective.

Methods:  All patients attending the Head and Neck Clinic during 2004 were prospectively assessed in this study. Patient records were analysed regarding investigative modalities including FNA, the subsequent cytology result and the requirement for further histopathological investigations. A cost analysis for all investigative procedures was performed.

Results:  A total of 135 patients (36 males) had FNAs performed during the study period. The median age was 51.5 years (range 17–92). Patients presented with lesions of lymph nodes (n = 46), thyroid (n = 41), salivary, parotid or submandibular glands (n = 22) and other cutaneous or cystic lesions (n = 26). Cytological grading results were; C1 = 26, C2 = 93, C3 = 8, C4 = 2 and C5 = 6. Patients with lesions C3 or above normally proceeded to further investigations. The overall cost of the FNA per episode in the out‐patient clinic was £114 per episode compared to day case open biopsy per patient of £333 and an in‐patient stay per patient was £2371. FNA provided sufficient pathological diagnosis to avoid day case surgery in 57 patients (42.2%), and inpatient surgery in 65 patients (48.1%) resulting in a total saving of £158 372 in 2004.

Conclusion:  This study demonstrates the clinical benefit and cost‐effectiveness of FNA services in a dedicated Head and Neck clinic.
Evaluating drought effect on MODIS Gross Primary Production (GPP) with an eco‐hydrological model in the mountainous forest, East Asia
Authors: HWANG TAEHEE , KANG SINKYU , KIM JOON , KIM YOUNGIL , LEE DOWON , BAND LAWRENCE
Published: January 2008

Surface soil moisture dynamics is a key link between climate fluctuation and vegetation dynamics in space and time. In East Asia, precipitation is concentrated in the short monsoon season, which reduces plants water availability in the dry season. Furthermore, most forests are located in mountainous areas because of high demand for agricultural land, which results in increased lateral water flux and uneven distribution of plant available water. These climatic and topographic features of the forests make them more vulnerable to drought conditions. In this study, the eco‐hydrological model (Regional Hydro‐Ecological Simulation System) is validated with various water and carbon flux measurements in a small catchment in Korea. The model is then extended to the regional scale with fine‐resolution remote sensing data to evaluate the Moderate Resolution Imaging Radiometer (MODIS) leaf area index and gross primary productivity (GPP) products. Long‐term model runs simulated severe drought effect in 2001 well, which is clearly shown in the ring increment data. However, MODIS GPP does not capture this drought effect in 2001, which might be from a simplified treatment of water stress in the MODIS GPP algorithm. This study shows that the MODIS GPP products can potentially overestimate carbon uptake specifically during drought conditions driven by soil water stress.
Expression of Langerin/CD207 reveals dendritic cell heterogeneity between inbred mouse strains
Authors: Flacher Vincent , Douillard Patrice , Aït‐Yahia Smina , Stoitzner Patrizia , Clair‐Moninot Valérie , Romani Nikolaus , Saeland Sem
Published: January 2008

Langerin/CD207 is expressed by a subset of dendritic cells (DC), the epithelial Langerhans cells. However, langerin is also detected among lymphoid tissue DC. Here, we describe striking differences in langerin‐expressing cells between inbred mouse strains. While langerin+ cells are observed in comparable numbers and with comparable phenotypes in the epidermis, two distinct DC subsets bear langerin in peripheral, skin‐draining lymph nodes of BALB/c mice (CD11chigh CD8αhigh and CD11clow CD8αlow), whereas only the latter subset is present in C57BL/6 mice. The CD11chigh subset is detected in mesenteric lymph nodes and spleen of BALB/c mice, but is virtually absent from C57BL/6 mice. Similar differences are observed in other mouse strains. CD11clow langerin+ cells represent skin‐derived Langerhans cells, as demonstrated by their high expression of DEC‐205/CD205, maturation markers, and recruitment to skin‐draining lymph nodes upon imiquimod‐induced inflammation. It will be of interest to determine the role of lymphoid tissue‐resident compared to skin‐derived langerin+ DC.