bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Dependence of Anisotropy and Saturation Magnetization in Iron and Iron-Silicon Alloys
Authors: Graham C. D.
Published: June 2005

The temperature dependence of the magnetocrystalline anisotropy constant K1 and of the saturation magnetization have been measured from 77 to 575°K on single-crystal samples of iron, 3.2% silicon-iron,and 5.1% silicon-iron. For iron and 3.2% Si-Fe, the anisotropy decreases as the third or fourth power of the magnetization at low temperatures; this increases to approximately the ninth power at high temperatures. The anisotropy of 5.1% Si-Fe decreases as the seventh or eighth power of the magnetization at low temperatures,and as the ninth power at high temperature.
Magnetic Anisotropy in Ferrimagnetie Crystals
Authors: Pearson R. F.
Published: June 2005

Absolute values of K1, the first-order anisotropy constant, have been determined at different temperatures from torque measurements on single crystals of the following compositions: MnxFe3−xO4, where 0.7 ≤ x ≤ 1.0; Cox Mn1−xFe2O4, where 0 ≤ x ≤ 0.25; Co0.04Mnx−0.04Fe3−xO4, where 0.70 ≤ x ≤ 0.91; GaxFe3−xO4, where 0 ≤ x ≤ 0.8; Sm3Fe5O12Gd3Fe5O12.

The magnetocrystalline anisotropy of manganese ferrous ferrite was found to vary considerably with the concentration of ferrous ions (Fe2+), some compositions even possessing a positive value of K1 at room temperature, as previously found by Penoyer (1959). In these cases, K1 becomes negative at low temperatures in contrast with the behavior of cobalt-substituted crystals which are found to have rapidly increasing positive values of K1 as the temperature is reduced. The anisotropy contribution of cobalt ions(Co2+) substituted in manganese ferrous ferrite varies with crystals of different compositions.

The experimental values of K1 are compared wherever possible with present theories of magnetic anisotropy. In particular, the recent theory proposed by Slonczewski (1958) to explain the anisotropy of cobalt ions substituted in magnetite (Fe3O4) is found to be unsuccessful in the case of Co2+ ions in manganese ferrite (MnFe2O4).

Measurements at low temperatures on the gallium-substituted magnetite crystals reveal an additional interesting effect. For certain crystals, the torque curves at 80°K exhibit considerable rotational hysteresis in fields above 10000 oe, when the material should certainly be saturated. This hysteresis is shown to be related to the ordering of the ferrous (Fe2+) and ferric (Fe3+) ionswhich takes place on the octahedral sites at low temperatures.
Localized Field Permanent Magnet Arrays
Authors: Stadler H. L.
Published: June 2005

Very short bar magnets can be grouped into linear arrays in such a way as to give a more localized field than does a single magnet of about the same size. Shaping the field from small magnet arrays is particularly important in the design of permanent magnet memories where the information is stored by the presence or absence of permanent magnets. To achieve high information density it is necessary to design magnet structures with very localized fields. Measurements of the response of a memory sensing element as a function of its distance from various magnets show that a linear array has a much stronger effect when very close to the sensor than does a single magnet of similar size and dipole moment.
Resonance Line Widths of Sintered Nickel Ferrites Having Low Porosities
Authors: Van Uitert L. G. , Soden R. R. , Swanekamp F. W.
Published: June 2005

The evolution of gas during sintering can act as a source of line broadening in low porosity ferrites. When this occurs there are systematic dependencies of ΔH (line width) upon sintering conditions but not upon porosity. Nickel ferrites sintered under such nonideal conditions show minima in ΔH as a function of cobalt content. When the same materials are sintered under more ideal conditions, ΔH increases linearly with cobalt. ΔH varies as the reciprocal of saturation magnetization for modified nickel ferrites prepared under the most ideal conditions. The effects of anisotropy field and dipole narrowing on ΔH are evident.
Effect of Applying a Magnetic Field During Neutron Irradiation on the Magnetic Properties of Fe-Ni Alloys
Authors: Schindler A. I. , Salkovitz E. I.
Published: June 2005

To test the similarity between thermally induced ordering and irradiation induced ordering, a series of commercial Fe-Ni samples have been irradiated in the presence of a saturating magnetic field. Square hysteresis loops were found for all the samples irradiated in this manner. Such results are consistent with the proposal that directional short range ordering and consequent uniaxial anisotropy has been created by the neutron irradiation.
Effect of Eddy Currents on Domain Wall Behavior Configurations, Wall Motion, and Loss for a Domain Model of Cube-On-Edge Material
Authors: Agarwal P. D. , Graham D. C.
Published: June 2005

Domain wall motion in single crystals and polycrystalline material has been observed and studied by many physicists and metallurgists under different conditions of excitation. The field has been applied in the rolling direction and in the cross rolling direction and observations made on the surface of the domain wallmotion. In these studies the rate of change of wall motion of necessity must be slow because of the limitations of the procedure for following and photographing the wall motion. It has been recognized that at higher frequencies, the wall tends to bow, but the actual motion has not been defined. The published data under dc excitation conditions, along with the required minimum energy relationship, establishes the boundary conditions that must be met by a domain model for polycrystalline cube-on-edge material. A domain model has been developed which appears to fit these boundary conditions under dc excitation.

Analysis of the induced voltage and resulting eddy currents was made on the assumption that the domain wall remain straight and that the velocity was such as to give sinusoidal flux change. The actual flow of eddy currents dictated that the wall must bow. By modifying the domain wall motion to fit the conditions as dictated by the eddy currents, the eddy current losses were calculated and compared with losses measured in present-day material. The variations of magnetizing force with time are also calculated and show reasonable agreement with expected excitation curves versus time.
Temperature Dependence of the Saturation Magnetization of Ferrites with Magnetoplumbite Structure
Authors: Heimke G.
Published: June 2005

The anomaly in the saturation magnetization vs temperature dependence of ferrites with magnetoplumbite structure is supposed to be caused by the fact that the superexchange interactions of the five crystallographically distinguished sublattices may be of several kinds in a part of the unit cell. It is shown that the interaction chain can be made to be of one kind only by replacement of the iron ions of one sublattice by nonmagnetic ions, and the conditions under which this replacement can be effected are pointed out. Experimental evidence demonstrates that this can partly be achieved by using BaTiO3 instead of BaCO3 in the starting mixture, if special precautions as to the sintering conditions are taken.
Magnetic Properties of the LixMn1−xSe System
Authors: McGuire Thomas R. , Heikes Robert R.
Published: June 2005

The details of the magnetic behavior of the LixMn1−xSe system are attributed to the double exchange interaction. At low temperatures, the hole, which is introduced by the Li+, is bound to the Li+ itself. Double exchange causes local distortions of the spin system. As the concentration is increased (x = 0.07), these local distortions overlap sufficiently so that a magnetic field will induce a suitable moment. Finally at x = 0.10one finds that spontaneous magnetization develops below 110°K. As the temperature is lowered through 70°K, the spontaneous moment disappears and an antiferromagnetic state is found. This phase change is attributed to the binding of the holes to the Li+.
Cross-Tie Walls in Thin Films
Authors: Rubinstein Harvey , Spain Robert J.
Published: June 2005

Various properties of cross-tie walls are summarized. Several new Bitter pattern experiments dealing with cross-tie walls are described. The first experiment firmly determines the magnetization distribution about a cross-tie, with the aid of an applied field at 45° to the wall. The second experiment tests the stability of cross-tie walls. It is shown in this experiment that another wall configuration is possible. This is discussed in light of the buckling mechanism of film switching.
Neutron Diffraction Investigation of the Fe1−δS System
Authors: Sparks J. T. , Mead W. , Kirschbaum A. J. , Marshall W.
Published: June 2005

The intensity of the purely magnetic (001) reflection has been investigated as a function of temperature for Fe1−δS samples with δ = 0.02, 0.066, 0.099 and 0.107. Samples from the antiferromagnetic α′ phase, δ = 0.02, exhibit a spin reorientation at a temperature corresponding closely to that at which the susceptibility anomaly occurs (125°C). Preliminary measurements on a stoichiometric sample, δ = 0, suggest that for this composition, two distinct spin reorientations occur, one at 140°C corresponding to the abrupt change in susceptibility and the second at 160°C. The presence of a small (001) reflection at room temperature in the α′-phase samples, and the appearance of the x-ray powder diffraction photographs suggest that a mixed phase region may exist below the α′ transition. Quenching from above the α′ transition produces samples which show no room temperature peak, and whose x-ray patterns indicate only a single phase. An examination of the (001) reflection of samples for which δ = 0.066, 0.099 and 0.107, suggests that for these compositions the spins lie in the hexagonal planes from room temperature to the Néel temperature, 320°C. No anomalies were observed for δ = 0.066 at the α′′ transition or in the γ region. Also no evidence of disorder occurring in the spin system below Tn was observed with either δ = 0.099 or δ = 0.107.
Magnetic Moments of Alloys of Gadolinium with Some of the Transition Elements
Authors: Hubbard W. M. , Adams E. , Gilfrich J. V.
Published: June 2005

Alloys of gadolinium with some of the transition elements were prepared and examined by x-ray and magnetic techniques in an effort to determine their structure, Curie temperatures and magnetic moments.

Values obtained for the saturation magnetization for some compositions in the gadolinium-cobalt system were higher than those reported by Nesbitt et al., but the data agree qualitatively with their theory of an antiferromagnetic interaction. An increase in saturation magnetization at room temperature and below was noted for some compositions that were cooled from their Curie points in a magnetic field. An extremely high intrinsic coercive force (IHc = 8000) was measured on the powdered hexagonal compound GdCo5 indicating a high anisotropy for this structure. The lattice parameters for a face centered cubic and two hexagonal phases in this system were calculated from the x-ray data.

The structure of the gadolinium-manganese system was found to be extremely complex, and only the compound GdMn2 was identified. Magnetic moment vs temperature values were also determined for various compositions. The Curie temperature for the composition Gd0.2Mn0.8 was found to be approximately 250°C.
Ferromagnetic-Alloy Phases Near the Compositions Ni2MnIn, Ni2MnGa, Co2MnGa, Pd2MnSb, and PdMnSb
Authors: Hames F. A.
Published: June 2005

In a search for further examples of Heusler-type alloys, ferromagnetic alloys were found near the composition Ni2MnIn, Ni2MnGa, Co2MnGa, Pd2MnSb, and PdMnSb. The first four alloys are tentatively identified as having the L21(Heusler)-type structure; PdMnSb, the Cl1-type structure. Previous work has indicated that ferromagnetism in these types of alloys is associated with Mn-Mn distances in the range 4.17–4.37 A. The present work indicates that ferromagnetism persists with Mn-Mn distances as small as 4.08 A (Co2MnGa) and as large as 4.42 A (PdMnSb); and that ferromagnetism disappears if the Mn-Mn distances become too large. Pd2MnSb, with Mn-Mn distance 4.55 A, is only feebly magnetic at room temperature.
Recent Developments in Ferromagnetic Resonance at High Power Levels
Authors: Schlömann E. , Green J. J. , Milano U.
Published: June 2005

The influence of inhomogeneities on the saturation of the ferromagnetic resonance is investigated. In the region of moderate power levels, the susceptibility at resonance χ′′ varies linearly with the square of the rf field h. The magnitude of the slope ∂χ′′/∂h2 depends on the nature of the dominant scattering mechanism. If the uniform mode scatters primarily to spin waves of very large wavelength, the slope should be negative. Scattering to spin waves of short wavelength gives a positive contribution to the slope and can lead to a reversal of the sign. The theoretical predictions agree with measurements at X band on various polycrystalline garnets and ferrites.

At very high power levels the opening angle of the precessing magnetization vector approaches a limiting value, which is related to the “line width” ΔHk of z directed spin waves having the same frequency as the uniform mode. Experiments on single crystals and polycrystals of rare earth substituted garnets show that ΔHkincreases approximately linearly with the rare earth content. The materials investigated contain Gd, Yb, Er, Sm, Dy, Ho, or Tb and for a given ratio of substitution ΔHk increases in that order. The line width ΔHk of z directed spin waves is found to be approximately proportional to the line width ΔH of the uniform mode as measured in single crystals.

Experimental results on cobalt and zinc substituted nickel ferrite are reported. ΔHk increases linearly with the cobalt content. For the nickel-zinc ferrites with a large magnetic moment the saturation curve (χ′′ vs h2) measured at X band shows a maximum well below the initial onset of nonlinearity. A theoretical explanation for this extraordinary behavior is given.

A new nonlinear effect arising from spin wave instability in a microwave magnetic field applied parallel to the dc field has been observed. Spin waves which propagate in directions perpendicular to the dc field are most susceptible to this instability. The observed variation of the critical rf field strength agrees well with the theoretical predictions. It indicates that the spin-wave line width increases with increasing wave number and decreasing angle between propagation direction and dc magnetic field.
Transfer Function and Error Probability of a Digital Magnetic Tape Recording System
Authors: Hung John Wenchung
Published: June 2005

In spite of the complexities of the digital magnetic recording system, it has been discovered that the output of the system for the input of a unit step of current can be approximated by a Gaussian probability function A exp[−a(x−d)2]. The value “a” in A exp[−a(x−d)2] is a figure of merit of the system.

This yields an analytic expression for the transfer function of the system. Experimental results correlate quite well with those based on this approximate transfer function.

Using this transfer function, the output of the system for any Nonreturn to Zero recording method can be predicted. For example, the reduction in system output with increasing bit densities is established. In addition, when Gaussian noise is introduced into the system, the error probability is obtained. The effect of the input rise time to the output amplitude is discussed.
Blood Flow Measurements Using Dynamical Paramagnetic Relaxation Times and Paramagnetic Tracer Techniques
Authors: Singer J. R.
Published: June 2005

The effect of flow on the paramagnetic relaxation time of fluids is discussed. The saturation or magnetization inversion of a group of nuclear moments constitutes a short-lived tracer for these moments permitting flow velocity measurements. For long-lived tracers, a given set of molecules with a well-known nuclear or electron paramagnetic resonance spectrum may be employed. Experimental measures of blood flow velocity in mice are discussed.
Experimental evidence rejects pairwise modelling approach to coexistence in plant communities
Authors: Dormann Carsten F , Roxburgh Stephen H
Published: June 2005

Competition is often invoked as the cause of plant species loss with increasing system productivity. Experimental results for multispecies assemblages are virtually absent and mathematical models are thus used to explore the relationship between competition and coexistence. Modelling approaches to coexistence and diversity in competitive communities commonly employ Lotka–Volterra-type (LV) models with additive pairwise competitive effects.

Using pairwise plant competition experiments, we calibrate the LV system and use it to predict plant biomass and coexistence in six three-species and one seven-species experimental mixture. Our results show that five out of the six three-species sets and the seven-species set deviate significantly from LV model predictions. Fitting an additional non-additive competition coefficient resulted in predictions that more closely matched the experimental results, with stable coexistence suggested in all but one case. These results are discussed with particular reference to the possible underlying mechanisms of coexistence in our experimental community. Modelling the effect of competition intensity on stability indicates that if non-additive effects occur, they will be relevant over a wide range of community sizes. Our findings caution against relying on coexistence predictions based on LV models.
Pax3/Pax7 mark a novel population of primitive myogenic cells during development
Authors: Kassar-Duchossoy Lina , Giacone Ellen , Gayraud-Morel Barbara , Jory Aurélie , Gomès Danielle , Tajbakhsh Shahragim
Published: June 2005

Skeletal muscle serves as a paradigm for the acquisition of cell fate, yet the relationship between primitive cell populations and emerging myoblasts has remained elusive. We identify a novel population of resident Pax3+/Pax7+, muscle marker-negative cells throughout development. Using mouse mutants that uncouple myogenic progression, we show that these Pax+ cells give rise to muscle progenitors. In the absence of skeletal muscle, they apoptose after down-regulation of Pax7. Furthermore, they mark the emergence of satellite cells during fetal development, and do not require Pax3 function. These findings identify critical cell populations during lineage restriction, and provide a framework for defining myogenic cell states for therapeutic studies.
Rater Personality, Rating Format, and Social Context: Implications for Performance Appraisal Ratings
Authors: Yun Gunna J. , Donahue Lisa M. , Dudley Nicole M. , McFarland Lynn A.
Published: June 2005

This study investigates the effects of rater personality (Conscientiousness and Agreeableness), rating format (graphic rating scale vs. behavioral checklist), and the rating social context (face‐to‐face feedback vs. no face‐to‐face feedback) on rating elevation of performance ratings. As predicted, raters high on Agreeableness showed more elevated ratings than those low on Agreeableness when they expected to have the face‐to‐face feedback meeting. Furthermore, rating format moderated the relationship between Agreeableness and rating elevation, such that raters high on Agreeableness provided less elevated ratings when using the behavioral checklist than the graphic rating scale, whereas raters low on Agreeableness showed little difference in elevation across different rating formats. Results also suggest that the interactive effects of rater personality, rating format, and social context may depend on the performance level of the ratee. The implications of these findings will be discussed.
A Criterion‐Related Validation Study of Transit Operators
Authors: Chung‐Yan Greg A. , Cronshaw Steven F. , Hausdorf Peter A.
Published: June 2005

This paper presents the results of a theory‐guided validation study conducted in a large urban transit authority. Four selection predictors were evaluated: an eye–hand–foot co‐ordination test, a cognitive and perceptual ability test, a work preference inventory, and a behaviour description structured interview that assessed adaptive and interpersonal skills. These predictors were evaluated against a comprehensive domain of job performance that included on‐the‐job observations, accidents, complaints, commendations, absences, organizational commitment, and job and work involvement. Although the results were mixed, the results generally support the use of measures of non‐intellective variables (i.e., work preference inventory and interview) when predicting transit operator performance.
Effect of concomitant dosing of famotidine with lansoprazole on gastric acid secretion in relation to CYP2C19 genotype status
Authors: FURUTA T. , SHIRAI N. , SUGIMOTO M. , NAKAMURA A. , OKUDAIRA K. , KAJIMURA M. , HISHIDA A.
Published: June 2005

Background : Famotidine increases Helicobacter pylori‐eradication rates by a triple lansoprazole/amoxicillin/clarithromycin therapy in patients with the rapid extensive metabolizer genotype of CYP2C19.

Aim : To determine the effect of famotidine on the gastric acid inhibition by lansoprazole in relation to CYP2C19 genotypes.

Methods : Twenty healthy volunteers with different CYP2C19 genotypes – consisting of six rapid extensive metabolizers, nine intermediate metabolizers and five poor metabolizers – underwent three 7‐day courses with placebo, lansoprazole 30 mg twice daily, and lansoprazole 30 mg twice plus famotidine 20 mg twice daily. Lansoprazole was dosed after breakfast and dinner. Famotidine was dosed after lunch and at bedtime. Intragastric pH monitoring was performed for 24 h on day 7 of each course.

Results : With placebo, no difference was observed in intragastric pH profiles among the three CYP2C19 genotype groups. With lansoprazole 30 mg twice daily, the median of 24‐h intragastric pH in poor metabolizers (6.1) was significantly higher than those of rapid extensive metabolizers (4.5) and intermediate metabolizers (5.0), respectively (P = 0.0176 and 0.0388), whereas with lansoprazole 30 mg twice and famotidine 20 mg twice daily, the medians were 5.4, 5.7, and 6.1, respectively (not significant).

Conclusion : Acid inhibition by lansoprazole was influenced by CYP2C19 genotype status. This influence was offset by the concomitant use of famotidine.
The prevalence and correlates of urinary tract symptoms in Norwegian men: The HUNT Study
Authors: Seim Arnfinn , Hoyo Cathrine , Østbye Truls , Vatten Lars
Published: June 2005

OBJECTIVES

To estimate the prevalence of lower urinary tract symptoms (LUTS) by severity (using the International Prostate Symptom Score, IPSS) in a population‐based study of men aged ≥ 20 years, and to assess the association between putative risk factors and the presence of moderate to severe LUTS.

SUBJECTS AND METHODS

Between 1995 and 1997, LUTS data were collected from 21 694 male residents aged ≥ 20 years in Nord Trøndelag County in Norway, using the IPSS; from the IPSS (score 0–35) LUTS was defined as a score of ≥ 8, indicating moderate to severe symptoms. We estimated the prevalence of LUTS and used logistic regression analysis to study lifestyle and anthropometric factors, and comorbidity related to LUTS.

RESULTS

The overall prevalence of moderate to severe LUTS was 15.8% (13.2% moderate and 2.6% severe). The prevalence of LUTS increased strongly with age, from ≈ 5% among men aged < 40 years to > 30% when aged ≥ 70 years. Factors positively associated with an increased risk of moderate and severe LUTS were anthropometric (body mass index and waist hip ratio) and lifestyle factors (alcohol consumption and smoking), as well as comorbid conditions, including diabetes, history of stroke, muscle complaints and osteoarthritis.

CONCLUSION

The findings from this population‐based study suggest that the prevalence of LUTS among men aged ≥ 20 years may be lower than previously estimated. Although LUTS may be viewed as an inevitable consequence of ageing, it appears to be exacerbated by lifestyle factors and comorbid conditions.
The involvement of Cav3.2/α1H T‐type calcium channels in excitability of mouse embryonic primary vestibular neurones
Authors: Autret Laurence , Mechaly Ilana , Scamps Frédérique , Valmier Jean , Lory Philippe , Desmadryl Gilles
Published: June 2005

Ca2+ influx through voltage‐gated calcium channels probably influences neuronal ontogenesis. Many developing neurones transiently express T‐type/Cav3 calcium channels that contribute to their electrical activity and potentially to their morphological differentiation. Here we have characterized the electrophysiological properties and the functional role of a large T‐type calcium current that is present in mouse developing primary vestibular neurones at embryonic day E17. This T‐type current showed fast activation and inactivation, as well as slow deactivation kinetics. The overlap of activation and inactivation parameters produced a window current between −65 and −45 mV. Recovery from short‐term inactivation was slow suggesting the presence of the Cav3.2 subunit. This T‐type current was blocked by micromolar concentrations of Ni2+ and was inhibited by fast perfusion velocities in a similar fashion to recombinant Cav3.2 T‐type channels expressed in HEK‐293 cells. More importantly, current clamp experiments have revealed that the T‐current could elicit afterdepolarization potentials during the repolarization phase of action potentials, and occasionally generate calcium spikes. Taken together, we demonstrate that the Cav3.2 subunit is likely to be the main T‐type calcium channel subunit expressed in embryonic vestibular neurones and should play a key role in the excitability of these neurones during the ontogenesis of vestibular afferentation.
Crystal Structure of Human Toll-Like Receptor 3 (TLR3) Ectodomain
Authors: Choe Jungwoo , Kelker Matthew S. , Wilson Ian A.
Published: June 2005

Toll-like receptors (TLRs) play key roles in activating immune responses during infection. The human TLR3 ectodomain structure at 2.1 angstroms reveals a large horseshoe-shaped solenoid assembled from 23 leucine-rich repeats (LRRs). Asparagines conserved in the 24-residue LRR motif contribute extensive hydrogen-bonding networks for solenoid stabilization. TLR3 is largely masked by carbohydrate, but one face is glycosylation-free, which suggests its potential role in ligand binding and oligomerization. Highly conserved surface residues and a TLR3-specific LRR insertion form a homodimer interface in the crystal, whereas two patches of positively charged residues and a second insertion would provide an appropriate binding site for double-stranded RNA.
KNOTS, BRAIDS AND HEDGEHOGS FROM THE EIKONAL EQUATION
Authors: WERESZCZYŃSKI A.
Published: June 2005

The complex eikonal equation in the three space dimensions is considered. We show that apart from the recently found torus knots, this equation can also generate other topological configurations with a nontrivial value of the π2(S2) index: braided open strings as well as hedgehogs. In particular, cylindric strings, i.e. string solutions located on a cylinder with a constant radius are found. Moreover, solutions describing strings lying on an arbitrary surface topologically equivalent to cylinder are presented. We discuss them in the context of the eikonal knots. The physical importance of the results originates in the fact that the eikonal knots have been recently used to approximate the Faddeev–Niemi hopfions.
VACUUM ENERGY DENSITY AND COSMOLOGICAL CONSTANT IN dS BRANE-WORLD
Authors: CHANG ZHE , CHEN SHAO-XIA , WEN HAI-BAO , HUANG XIN-BING
Published: June 2005

We discuss the vacuum energy density and the cosmological constant of dS5 brane-world with a dilaton field. It is shown that a stable AdS4 brane can be constructed and gravity localization can be realized. An explicit relation between the dS bulk cosmological constant and the brane cosmological constant is obtained. The discrete mass spectrum of the massive scalar field in the AdS4 brane is used to acquire the relationship between the brane cosmological constant and the vacuum energy density. The vacuum energy density in the brane gotten by this method is in agreement with astronomical observations.
RECENT RESULTS FROM LEPS
Authors: NAKANO T.
Published: June 2005

The photon beam at the LEPS facility is produced by backward-Compton scattering of laser photons from 8 GeV electrons at the SPring-8. The status and prospects of the experimental study on the Θ+ at LEPS are reported. Further evidences for pentaquark baryons and counter-evidences are also discussed.
DYNAMICALLY GENERATED RESONANCES IN THE CHIRAL UNITARY APPROACH TO MESON BARYON INTERACTION
Authors: OSET E. , SARKAR S. , VICENTE VACAS M. J. , RAMOS A. , JIDO D. , OLLER J. A. , MEISSNER U. G.
Published: June 2005

In this talk we report on the use of a chiral unitary approach for the interaction of the octets of meson and baryon and the octet of mesons with the decuplet of baryons. Two octets of Jπ=1/2- baryon states and a singlet are generated dynamically in the first case, resulting in the case of strangeness S=-1 in two poles of the scattering matrix close to the nominal Λ(1405) resonance. In the second case many resonances are also generated, among them an exotic baryon with S=1 corresponding to a ΔK resonance. We make suggestions of experiments which could show evidence for the existence of these states.
ON QCD INVESTIGATIONS OF CHIRAL LAGRANGIAN
Authors: WANG QING
Published: June 2005

I review the present status of QCD investigations on chiral Lagrangian for pseudo scalar mesons.
LOW ENERGY PION-NUCLEON SCATTERING
Authors:   For the CHAOS Collaboration., TACIK ROMAN
Published: June 2005

The CHAOS Collaboration at TRIUMF has measured differential cross sections for π±p elastic at incident pion kinetic energies of 19.9, 25.8, 32.0, 37.1, 43.3, 57.0, and 67.0 MeV. The data analysis at the five lowest energies has been completed at the University of Tübingen. In order to measure at forward angles, in the Coulomb-Nuclear Interference region, the CHAOS detector was modified from its standard configuration with a specially developed range telescope. μ±p scattering at forward angles was also measured simultaneously, and used for validation of acceptance simulations.
THE CHIRAL QUARK MODEL AND BARYON PHENOMENOLOGY
Authors: RISKA D. O.
Published: June 2005

The chiral quark model posits that pions couple to the axial current of constituent quarks. This chiral pion coupling governs the pion decays of baryon resonances and also implies pion and multipion interactions between the quarks. The qualitative features of this model for the description of pionic decay widths and baryon spectra are outlined. When the covariant quark model wave function for the nucleon is chosen so as to describe the empirical nucleon form factors the pion decay widths of the positive parity resonances are underpredicted. This indicates the presence of significant multiquark components in these resonances.
BARYONIC RESONANCES FROM BARYON DECUPLET-MESON OCTET INTERACTION
Authors: VICENTE VACAS M. J. , OSET E. , SARKAR SOURAV
Published: June 2005

The s-wave interactions of the baryon decuplet with the octet of pseudoscalar mesons is studied in a unitarized coupled channel approach. We obtain a fair agreement for mass and width of several [Formula: see text] resonances. In particular, the Ξ(1820), the Λ(1520) and the Σ(1670) states are well reproduced. Other resonances are predicted and also the couplings of the observed resonances to the various channels are evaluated.
UNITARY CHIRAL DYNAMICS IN J/Ψ DECAYS INTO VPP AND THE ROLE OF THE SCALAR MESONS
Authors: ROCA L. , PALOMAR J. E. , OSET E. , CHIANG H. C.
Published: June 2005

We make a theoretical study of the J/Ψ decays into ωππ, ϕππ, [Formula: see text] and [Formula: see text] using the techniques of the chiral unitary approach stressing the important role of the scalar resonances dynamically generated through the final state interaction of the two pseudoscalar mesons. We also discuss the importance of new mechanisms with intermediate exchange of vector and axial-vector mesons and the role played by the OZI rule in the J/Ψϕππ vertex, quantifying its effects. The results nicely reproduce the experimental data for the invariant mass distributions in all the channels considered.
QUARK DISTRIBUTIONS AND NUCLEON SPIN STRUCTURE
Authors: KHORRAMIAN ALI N. , MIRJALILI A. , TEHRANI S. ATASHBAR
Published: June 2005

In this paper we calculate spin dependence of parton distributions and proton structure function. The polarized valon distributions in a proton and the polarized parton distributions inside the valon are necessary to obtain the polarized parton distributions in a proton. The results of our calculations for the proton structure function, [Formula: see text] are in good agreement with the available experimental data. We obtain the spin contribution and angular momentum of the valons to the proton.
A SEARCH FOR NEUTRAL BARYON RESONANCES BELOW PION THRESHOLD
Authors: JIANG XIAODONG
Published: June 2005

The reaction p(e,e′π+)X0 was studied with two high resolution magnetic spectrometers to search for narrow baryon resonances. A missing mass resolution of 2.0 MeV was achieved. A search for structures in the mass region of 0.97<MX0<1.06 GeV yielded no significant signal. The yield ratio of p(e,e′π+)X0/p(e,e′π+)n was determined to be (-0.35±0.35)×10-3 at 1.004 GeV and (0.34±0.42)×10-3 at 1.044 GeV. This measurement clearly demonstrated the potential of high resolution missing mass searches in coincidence experiments.
NON-NUCLEAR MULTIQUARK STATES: DIBARYONS AND PENTAQUARKS FROM A SUCCESSFUL NUCLEAR QUARK MODEL
Authors: GOLDMAN T.
Published: June 2005

A model for nuclei described directly in terms of quarks has been developed in both relativistic and non-relativistic forms. It describes nuclear binding energy and structure for small nuclei (A=3,4) systematically correctly, including the EMC effect. With one free parameter each for strange and for nonstrange states, it also well describes low energy baryon-nucleon scattering, phase shifts and potentials. It predicts low mass, narrow dibaryon and pentaquark states. To be consistent with reported states, new physics may be required that is not included in any quark model to date.
MULTI-QUARK STATES IN THE INHERENT NODAL STRUCTURE ANALYSIS
Authors: LIU YUXIN , LI JINGSHENG
Published: June 2005

The strangeness s=+1 pentaquark states [Formula: see text] and the six-quark quark clusters qqqqqq are investigated. By analyzing the inherent nodal structure of the systems, the low-lying states are picked out. By comparing the accessibility of the nodeless states and referring the presently obtained K - N interaction potential, we propose that the quantum numbers of the lowest-lying pentaquark state Θ+ may be (JP, T)=(½+,0) and L=1. Meanwhile, the possible dibaryon states are briefly discussed.
RELATIVISTIC DESCRIPTION OF QUASIFREE ETA PHOTOPRODUCTION
Authors: VAN DER VENTEL B. I. S. , ABU-RADDAD L. J. , HILLHOUSE G. C.
Published: June 2005

A relativistic plane wave formalism for quasifree eta meson photoproduction is presented. The sensitivity of the unpolarized differential cross section, the recoil nucleon polarization, and the photon asymmetry is investigated. The results indicate that the S11 resonance dominates the unpolarized differential cross section, but that its contribution to the spin observables are very small, for which the D13 resonance plays the primary role.
ENERGY DISTRIBUTION IN A BTZ BLACK HOLE SPACETIME
Authors: VAGENAS ELIAS C.
Published: June 2005

We evaluate the energy distribution associated with the (2+1)-dimensional rotating BTZ black hole. The energy–momentum complexes of Landau–Lifshitz and Weinberg are employed for this computation. Both prescriptions give exactly the same form of energy distribution. Therefore, these results provide evidence in support of the claim that, for a given gravitational background, different energy–momentum complexes can give identical results in three dimensions, as is the case in four dimensions.
RIGIDLY ROTATING STRANGE QUARK STARS
Authors: YILMAZ İHSAN , BAYSAL HÜSNÜ
Published: June 2005

In this article, we study rotating strange quark stars in the context of general relativity. For this purpose we consider perfect fluid model composed of strange quark matter with electromagnetic field in the Gödel Universe which has rigid rotation. We solve Einstein's field equations by using equation of state for strange quark matter. Also, we discuss the features of obtained solutions.
OCCUPATION TIMES OF BROWNIAN SEGMENTS AND THE σ-FINITE WIENER MEASURE
Authors: BOJDECKI TOMASZ , GOROSTIZA LUIS G.
Published: June 2005

We give an asymptotic result for the occupation of Borel sets of functions by the segments of recurrent Brownian motion on consecutive time intervals [n, n +1], n =0, 1, 2, …. This result provides new information on the behavior of Brownian motion, which is illustrated by examples. A formulation in terms of weak convergence of random measures on Polish space is also given. The proof is based on (a strengthened form of) the Darling–Kac occupation time theorem for Markov chains, and our result can be viewed as a "trajectorial" extension of that theorem. The main role in the occupation limit for Brownian segments is played by the σ-finite Wiener measure, which first appeared in a different context. An extension for segments of symmetric α-stable Lévy processes is also given.
MALLIAVIN CALCULUS AND ANTICIPATIVE ITÔ FORMULAE FOR LÉVY PROCESSES
Authors: DI NUNNO GIULIA , MEYER-BRANDIS THILO , ØKSENDAL BERNT , PROSKE FRANK
Published: June 2005

We introduce the forward integral with respect to a pure jump Lévy process and prove an Itô formula for this integral. Then we use Mallivin calculus to establish a relationship between the forward integral and the Skorohod integral and apply this to obtain an Itô formula for the Skorohod integral.
CONSTRUCTING EXTENSIONS OF CP-MAPS VIA TENSOR DILATIONS WITH THE HELP OF VON NEUMANN MODULES
Authors: GOHM ROLF , SKEIDE MICHAEL
Published: June 2005

We apply Hilbert module methods to show that normal completely positive maps admit weak tensor dilations. Appealing to a duality between weak tensor dilations and extensions of CP-maps, we get an existence proof for certain extensions. We point out that this duality is part of a far reaching duality between a von Neumann bimodule and its commutant in which other dualities, known and new, also find their natural common place.
Timing of tectonic events in the Alpujárride Complex, Betic Cordillera, southern Spain
Authors: Platt J.P. , Kelley S.P. , Carter A. , Orozco M.
Published: June 2005

Ar–Ar and fission-track dating from four low-grade sections in the Alpujárride Complex sheds light on the timing of the early contractional history of these high-pressure metamorphic units, and their subsequent exhumation during the early Miocene extensional collapse of the Betic orogen. White mica grains from the lowest-grade rocks yield partly reset detrital Ar–Ar ages; where deformation and recrystallization are more intense, however, they yield reproducible ages as old as
c
. 48 Ma, which we interpret as the approximate timing of the main contractional event and associated high-pressure metamorphism in these units. Rocks from slightly higher-grade sections give reproducible Ar–Ar ages between 30 and 40 Ma, but these younger ages probably reflect the interplay of growth and cooling in fine-grained micas heated to between 300 °C and 400 °C during prograde metamorphism. In each of the four areas studied the low-grade rocks are separated by an extensional detachment or shear zone from medium-grade rocks below. In two areas these detachments have been folded around major overturned north-vergent folds. Ar–Ar data from structurally below the detachments, and fission-track ages from all structural levels, indicate the onset of significant cooling in the early Miocene, which corresponds to the age of the extensional event. The folds must therefore be early Miocene or younger.
Depositional architecture and transgressive–regressive cycles within Liassic backstepping carbonate ramps in the Basque–Cantabrian basin, northern Spain
Authors: Quesada Santiago , Robles Sergio , Rosales Idoia
Published: June 2005

An integrated stratigraphical, sedimentological, geochemical and sequential analysis has been carried out on the Liassic rocks of the Basque–Cantabrian basin in northern Spain using outcrop and subsurface data. The study documents the progressive drowning and backstepping of an epeiric carbonate ramp that originated during the worldwide late Triassic–early Jurassic transgression. Two major carbonate depositional systems have been recognized within the drowning succession: (1) a late Triassic–early Sinemurian shallow-marine ramp, which reflects a progressive marine transgression over Triassic continental deposits; (2) a late Sinemurian–Toarcian set of hemipelagic ramps, which recorded the progressive drowning and backstepping of the ramp system during a second major event of marine flooding. Sequence stratigraphic analysis of the Liassic succession has revealed that transgressive–regressive trends constitute the most evident cyclicity. A major transgressive–regressive cycle and six subsidiary transgressive–regressive facies cycles have been defined in the basin and compared with those defined in other European basins. Although a good correlation exists for the major transgressive–regressive cycle, significant discrepancies have been found for the number, limits and extent of the transgressive–regressive facies cycles reflecting the effects of local tectonics. The overall backstepping within the Basque–Cantabrian basin resulted in a dominance of transgressive episodes across a range of different scales. Accordingly, regressive intervals are less well developed except during limited periods of active tectonics as occurred in the mid-Sinemurian. These progressively longer and deeper marine flooding intervals, followed by relative stillstand or minor sea-level falls, are interpreted to reflect high thermal subsidence rates coupled with a Liassic eustatic transgression.
The Minch palaeo-ice stream, NW sector of the British–Irish Ice Sheet
Authors: STOKER MARTYN , BRADWELL TOM
Published: June 2005

Geophysical data from the UK continental shelf off NW Scotland reveal strongly parallel subglacial bedforms on the sea bed. Field mapping on the adjacent landmass has identified closely spaced bedrock megagrooves and highly elongate drumlinoid forms. All these mega-scale glacial lineations probably formed beneath the same fast-flowing zone of the last British–Irish Ice Sheet, The Minch palaeo-ice stream. This ice stream drained the NW sector of the British–Irish Ice Sheet during the Late Devensian Glaciation (marine isotope stage 2) and terminated near the edge of the continental shelf. The size of the adjacent trough-mouth Sula Sgeir Fan and the presence of buried mega-scale glacial lineations within the Quaternary stratigraphic record imply that fast ice-sheet flow in The Minch has been a feature of several mid- to late Pleistocene glaciations.
Effects of 7-day amino acid infusion on renal growth, function, and renin-angiotensin system in fetal sheep
Authors: Boyce Amanda C. , Gibson Karen J. , Wintour E. Marelyn , Koukoulas Irene , Lumbers Eugenie R.
Published: June 2005

These experiments examined whether renal growth and the fetal renin-angiotensin system could be stimulated by infusion of amino acids and whether chronic amino acid infusions restored glomerulotubular balance, which had been disrupted during 4-h infusions. Five fetal sheep aged 122 ± 1 days gestation received an infusion of alanine, glycine, proline and serine in 0.15 M saline at 0.22 mmol/min for 7 days. Six control fetuses were given saline at the same rate (5 ml/h). Kidney wet weights after amino acid infusion were 28% larger than control fetuses ( P < 0.05), and renal angiotensinogen mRNA levels were ∼2.6-fold higher ( P < 0.005). Circulating renin levels and renal renin mRNA levels were suppressed ( P < 0.05), and renal renin protein levels tended to be lower. Arterial pressure was increased, and there was a marked, sustained natriuresis and diuresis. Glomerular filtration rate and filtered sodium were ∼two-fold higher throughout infusion ( P < 0.05). Fractional proximal sodium reabsorption, suppressed at 4 h (from 73.4 ± 6.5 to 53.7 ± 10.2%), did not return to control levels (36.1 ± 3.4% on day 7, P < 0.05). Distal sodium reabsorption was markedly increased (from 79 ± 25 to 261 ± 75 μmol/min by day 7, P < 0.005), but this was not sufficient to restore glomerulotubular balance. The resultant high rates of sodium excretion led to hyponatremia and polyhydramnios. In conclusion, long-term amino acid infusions increased renal angiotensinogen gene expression, kidney weight, and distal nephron sodium reabsorptive capacity but failed to restore proximal and total glomerulotubular balance.
Frequency of Red Blood Cell Alloantibody in Kuwaiti Population
Authors: Ameen Reem , Al-Eyaadi Ohood , Al-Shemmari Salem , Chowdhury Rafiqul , Al-Bashir Abdulaziz
Published: June 2005

Objective: The aim of this study was to analyze the alloimmunization against red blood cells (RBC) among Kuwaiti population. Materials and Methods: Retrospective analysis of RBC alloimmunization among 179,045 Kuwaiti patients, pregnant women, and allogeneic blood donors was conducted for the period of 1992–2001. The frequency of 24 alloantibody specificities from 1,278 alloimmunized Kuwaitis was estimated. Results: The prevalence of positive antibody screen in Kuwait was 0.49%.The five most frequently identified alloantibodies were anti-D (27.3%), anti-E (18.5%), anti-K (15.6%), anti-Lea (8.7%), and anti-Leb (6.6%). Frequency of alloimmunization was greater among Kuwaiti female than male patients (3.2 F to 1 M). Anti-D (p < 0.001), anti-E (p = 0.05), anti-K (p = 0.04) were also more frequently identified alloantibody among Kuwaiti females. Conclusion: The results show higher predominance of RBC alloimmunization in females than males. Anti-D, anti-E, and anti-K were the most common clinically significant alloantibodies identified in the Kuwaiti population and were also more frequent among Kuwaiti females.
Iron Stores and Vascular Function in Voluntary Blood Donors
Authors: Zheng Haoyi , Cable Ritchard , Spencer Bryan , Votto Nancy , Katz Stuart D.
Published: June 2005

Background—

Iron is a pro-oxidant cofactor that may be linked to atherosclerosis progression. Reduction of body iron stores secondary to blood donation has been hypothesized to reduce coronary risk, but retrospective studies have yielded inconsistent findings. We sought to assess the effects of blood donation frequency on body iron stores and physiological and biochemical biomarkers of vascular function associated with atherosclerosis progression.

Methods and Results—

Forty high-frequency voluntary blood donors (≥8 donations in past 2 years) and 42 low-frequency blood donors (1 to 2 donations in past 2 years) aged 50 to 75 years were randomly selected from American Red Cross of Connecticut blood donor records. Flow-mediated dilation in the brachial artery, serum markers of iron stores, vascular inflammation and oxidative stress, and cardiac risk factors were assessed in all subjects. Serum ferritin was significantly decreased in high-frequency blood donors when compared with low-frequency blood donors (median values 17 versus 52 ng/mL;
P
<0.001), but hematocrit did not differ between groups. Flow-mediated dilation in the brachial artery was significantly greater in high-frequency donors when compared with low-frequency donors in univariate analysis (5.5±2.6% versus 3.8±1.6%;
P
=0.0003) and in multivariate analysis adjusting for cardiac risk factors and other potential confounders. Serum biomarkers of vascular inflammation did not differ between groups but 3-nitrotyrosine, a marker of oxidative stress, was decreased in high-frequency donors when compared with low-frequency donors.

Conclusions—

High-frequency blood donors had evidence of decreased body iron stores, decreased oxidative stress, and enhanced vascular function when compared with low-frequency donors. These findings support a potential link between blood donation and reduced cardiovascular risk that warrants further investigation in prospective outcome studies.