bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF POROSITY ON SEISMIC ATTENUATION
Authors: SUN YUE-FENG , KUO JOHN T. , TENG YU-CHIUNG
Published: November 2004

Effects of porosity on the attenuation of wave propagation are studied. The effects of pore fluids and porous structures are significant on changing the shapes of propagating wavelets. The waveform change of a propagating wavelet is much more sensitive to porosity than intrinsic attenuation. The attenuation occurred in natural rocks may largely due to these porous effects in addition to the internal friction of the solid represented by the intrinsic quality factor Q. The waveform of a propagating wavelet is quantitatively associated with attenuation, porosity, and fluid content, and is characterized by three parameters: the porosity ϕ, the quality factor Q, and the center frequency f0. Estimations of attenuation, porosity, and fluid content can be made by optimal wavelet analysis. High-resolution mapping of subsurface structures can be achieved by solving the integral equation with the nonlinear optimization of the time-variant wavelets. The inversion and the optimization schemes have been applied to study the porous sea floor and the crustal axial magma chamber (AMC) on the East Pacific Rise. These results provide porosity, attenuation information, and the highly resolved wave events, for further evaluation of compressional and shear wave velocities and other physical properties such as crack density and aspect ratio.
AN EXACT RADIATION CONDITION FOR USE WITH THE A POSTERIORI PE METHOD
Authors: THOMSON DAVID J. , MAYFIELD M. ELIZABETH
Published: November 2004

In the applications of the parabolic equation (PE) to underwater sound propagation, the radiation condition as z → ∞ is usually approximated numerically by appending an absorbing layer below the physical ocean bottom and imposing a simple pressure-release boundary condition at the base of the layer. A similar artifice is needed to prevent unphysical reflections from the top of the air layer in the applications of the PE to atmospheric sound propagation. In this paper, we replace this approximate boundary treatment for the standard PE with an exact, nonlocal boundary condition that can be applied along the sea-bottom or upper-atmosphere interface. Moreover, we make use of an exact relationship between the solution ψ of the standard PE and the solution p of the Helmholtz equation to postprocess the ψ field obtained using this nonlocal boundary condition into the p field. The effectiveness of this radiation condition and the a posteriori PE scheme is demonstrated for several examples that typify underwater and outdoor sound propagation in layered media.
COMPARISON OF LINEAR AND ORTHOGONAL BEAMFORMER PERFORMANCE FOR THE 1993 MATCHED FIELD PROCESSING BENCHMARKS
Authors: OZARD JOHN M. , BROUWER PETER , SCHEUER TIM
Published: November 2004

Results are presented for the Matched Field Processing (MFP) analysis of synthetic benchmark cases, performed by a comprehensive Acoustic Signal Processing (ASP) code used in a turnkey manner. The performance of the Generalized Bartlett Beamformer (GBB), Minimum Variance (MV), and Modified Reduced Minimum Variance (MRMV) processors incorporated in the ASP code were evaluated. Matches for replicas generated using normal mode and Parabolic Equation (PE) models produced virtually identical results. However, the choice of layered versus gradient models was shown to be a cause of sufficient mismatch and to alter the source position by several increments in range and depth if sufficiently fine layering was not employed. GBB and MRMV exhibit similar levels of robustness to mismatch, while MV showed its well-known sensitivity to mismatch. Our turnkey approach indicated that MFP techniques are relatively robust with respect to source detection and localization even when suboptimal modeling and processing parameters are used.
SECTOR FOCUSING FOR ROBUST HIGH RESOLUTION ANALYSIS OF THE MATCHED FIELD PROCESSING WORKSHOP DATA SET
Authors: SMITH G. B. , CHANDLER H. A. , FEUILLADE C. , MORRIS D. J.
Published: November 2004

Replica correlator, minimum variance distortionless response, and sector-focused processing are applied to the test data cases devised for the Matched Field Processing Workshop. The methods are compared on this data set and their performance is clearly delineated. In all the cases examined from the workshop data set which were appropriate for the application of sector-focused procedures (i.e. the presence of mismatch together with modal noise), sector-focused processing performed successfully. It located the source with robustness similar to the replica correlator processor, but with the higher resolution characteristic of minimum variance distortionless response processing. In all cases where replica correlator localizes correctly, sector focusing also localizes correctly and achieves higher resolution. Sector focusing always reduced signal gain degradation compared to minimum variance distortionless response processing. It also reduced signal gain degradation compared to replica correlator processing for the lowest signal-to-noise ratio case. However, significant range bias error was observed in sector-focused as well as replica correlator processing in the case with general mismatch and colored noise. Sector focusing was not applied to the case with sound speed mismatch but no colored noise.
LOW AND HIGH ORDER FINITE ELEMENT METHOD: EXPERIENCE IN SEISMIC MODELING
Authors: PADOVANI E. , PRIOLO E. , SERIANI G.
Published: November 2004

The finite element method (FEM) is a numerical technique well suited to solving problems of elastic wave propagation in complex geometries and heterogeneous media. The main advantages are that very irregular grids can be used, free surface boundary conditions can be easily taken into account, a good reconstruction is possible of irregular surface topography, and complex geometries, such as curved, dipping and rough interfaces, intrusions, cusps, and holes can be defined. The main drawbacks of the classical approach are the need for a large amount of memory, low computational efficiency, and the possible appearance of spurious effects.

In this paper we describe some experience in improving the computational efficiency of a finite element code based on a global approach, and used for seismic modeling in geophysical oil exploration. Results from the use of different methods and models run on a mini-superworkstation APOLLO DN10000 are reported and compared. With Chebyshev spectral elements, great accuracy can be reached with almost no numerical artifacts. Static condensation of the spectral element's internal nodes dramatically reduces memory requirements and CPU time. Time integration performed with the classical implicit Newmark scheme is very accurate but not very efficient. Due to the high sparsity of the matrices, the use of compressed storage is shown to greatly reduce not only memory requirements but also computing time. The operation which most affects the performance is the matrix-by-vector product; an effective programming of this subroutine for the storage technique used is decisive. The conjugate gradient method preconditioned by incomplete Cholesky factorization provides, in general, a good compromise between efficiency and memory requirements. Spectral elements greatly increase its efficiency, since the number of iterations is reduced. The most efficient and accurate method is a hybrid iterative-direct solution of the linear system arising from the static condensation of high order elements. The size of 2D models that can be handled in a reasonable time on this kind of computer is nowadays hardly sufficient, and significant 3D modeling is completely unfeasible. However the introduction of new FEM algorithms coupled with the use of new computer architectures is encouraging for the future.
OPTIMAL SOURCE LOCATIONS FOR VARIOUS GEOMETRIES FOR ACOUSTIC REFLECTORS BY BOUNDARY ELEMENT METHODS
Authors: SHAW RICHARD PAUL , SLOOTEN PAUL VAN , NOBILE MATTHEW
Published: November 2004

A boundary element method (BEM) approach is used to solve the acoustic problem of a point source within an enclosure with a large opening to an infinite (without a baffle) or semi-infinite (with a baffle) acoustic space. Emphasis is placed on 2D models with the source located along the center line of three types of geometries: a wedge, a parabola, and a rectangular enclosure.
A NONPLANAR SOURCE TO PLANAR APERTURE ALGORITHM
Authors: CHRISTOPHER TED
Published: November 2004

A new algorithm for modeling the propagation within a nonplanar source is presented. The algorithm represents the effects of diffraction and attenuation in the propagation of acoustic waves from a nonplanar source to the associated source aperture. The algorithm is a generalization of the linear propagation methods of Christopher and Parker [J. Acous. Soc. Am.90, 507–521 (1991)]. When used to propagate the normal velocity source description to obtain a pressure description of the field, the algorithm is equivalent to the Rayleigh integral model of Williams [J. Acous. Soc, Am.17, 219–227 (1946)] and O'Neil [J. Acous. Soc. Am.21, 516–526 (1949)]. Additionally, in propagating the field beyond the aperture plane the new algorithm allows for specified aperture plane conditions and facilitates the use of very efficient linear and nonlinear beam propagation methods. The algorithm can also be extended to approximate the effects of reflections occurring within the nonplanar source.

An efficient implementation of the algorithm is presented for axially symmetric sources. The correctness of the algorithm and implementation are demonstrated using a hemispherical reflective source. The results of the algorithm are then compared against the predictions of Coulouvrat [J. Acous. Soc. Am.94, 1663–1675 (1993)] and predictions obtained with the analytical axial solution for an ellipsoidal reflector of Hamilton [J. Acous. Soc. Am.93, 1256–1266 (1993)].
SPIN-POLARIZED ELECTRON ENERGY LOSS SPECTROSCOPY
Authors: HOPSTER H.
Published: November 2004

Spin-polarized electron energy loss spectroscopy (SPEELS) probes the spin-dependent electron-hole pair excitation spectrum at surfaces. It is a very surface sensitive method for the detection of surface magnetization. Indirectly, information on surface magnetic moments is obtained. SPEELS is capable of resolving layer-by-layer antiferromagnetic order as found in 3d metal (Cr, Mn, V) films on Fe(100).
THE STRUCTURE AND LATTICE DYNAMICS OF UNRECONSTRUCTED FCC (001) AND (111) METAL SURFACES
Authors: TONG S.Y. , CHEN Y. , BOHNEN K.P. , RODACH T. , HO K.M.
Published: November 2004

Progress in first-principles surface phonon calculation and multiple scattering phonon cross-section calculation has provided a more complete understanding of the localized vibrational modes on unreconstructed metal surfaces. A discussion of some of the new results is given focusing on how the new information resolves earlier difficulties in the interpretation of inelastic He-atom scattering (HAS) and high-resolution electron energy loss spectroscopy (EELS) data on these metal surfaces.
ROTATIONAL RAINBOW SCATTERING OF ORIENTED MOLECULES
Authors: KLEYN AART W.
Published: November 2004

Molecule-surface interactions depend on many degrees of freedom. In this report one degree of freedom is discussed in particular: the dependence of the interaction on the molecular orientation. Using electrostatic fields a thermal beam of oriented NO molecules is produced. By scattering this beam from a crystal, steric effects are measured for the direct scattering and adsorption of NO on Ag(111) and Pt(111). The interaction is quite different for both systems. Nevertheless, rotational rainbow scattering when the O-end of the molecule is facing the surface is observed in both cases. For NO–Pt(111) rotational rainbows are only observed at energies around 0.5 eV. Very strong randomisation is observed for NO scattering from Pt(111) at higher energies. The results are discussed in terms of the possible elementary topology of the potential energy surfaces.
PROBING SURFACE LATTICE DYNAMICS WITH HYPERTHERMAL ION SCATTERING
Authors: GOODSTEIN DAVID M. , DIRUBIO CHRISTOPHER A. , COOPER BARBARA H. , BURKE KIERON
Published: November 2004

In recent experiments, we have succeeded in measuring thermal momentum fluctuations of surface atoms using hyperthermal (E<500 eV) energy ions. These fluctuations lead to a broadening of the energy loss peaks observed in ion surface scattering experiments. Specifically, we have measured the temperature-dependent energy broadening (ΔE)2 of the quasisingle scattering peak for Na+ ions scattering from a Cu(001) surface, and found it to agree with a parameter-free theoretical prediction to within 10%. We point out that at lower temperatures than those of the present experiment, and with no detailed knowledge of the ion surface potential, this peak should yield quantitative information about the surface lattice dynamics.
IMAGING SURFACE ATOMIC STRUCTURE WITH ENERGY-DEPENDENT ELECTRON DIFFRACTION
Authors: TOBIN J.G. , WADDILL G.D.
Published: November 2004

The general concepts and approaches to extracting structural information from imaging with electron diffraction are outlined. Key issues that are addressed in the subsequent three papers are introduced in this overview article.
SURFACE CRYSTALLOGRAPHY BY INVERTING DIFFRACTION SPECTRA
Authors: TONG S.Y. , LI HUA , HUANG H.
Published: November 2004

New ideas on how to invert electron diffraction spectra to produce the atomic coordinates of surface region atoms are reviewed in this article. Some of the ideas are borrowed from optical holography while others are invented to deal with the strong multiple scattering and angular anisotropies present in electron diffraction in solids. The examples and references given in this and the accompanying two articles (by Heinz et al. and Wei et al. respectively) demonstrate that surface crystallography by data inversion is a viable method for a number of commonly used surface diffraction techniques.
SEPARATION OF INITIAL AND FINAL STATE CONTRIBUTIONS TO CHEMICAL SHIFTS IN TERMS OF A POTENTIAL MODEL
Authors: COLE R.J. , WEIGHTMAN P.
Published: November 2004

A recently developed potential model facilitates the separation of initial and final state contributions to chemical shifts in terms of ground state charge transfer and differences in core hole screening charge. The model is applied to the free atom to elemental solid shifts of the elements Na, Mg, Si, and Zn.
FIRST-PRINCIPLES STUDY OF SnO2 (110)
Authors: MANASSIDIS I. , GILLAN M.J.
Published: November 2004

Accurate first-principles calculations are used to study the relaxed stoichiometric and reduced SnO 2 (110) surfaces. The reliability of the calculations is supported by tests on the perfect crystal. Sizable atomic relaxations at both surfaces are found. Oxygen loss leaves electron density around surface Sn atoms, which can be regarded as being in the Sn 2+ state. There are gap states for the reduced but not for the stoichiometric surface.
THE GROWTH MODES AND STRUCTURES OF NO ON Ni{111}
Authors: MAPLEDORAM L.D. , WANDER A. , KING D.A.
Published: November 2004

The growth modes of NO on Ni{111} have been determined using a novel LEED technique. Measurement of LEED intensities at the superstructure beam positions as a function of coverage indicate that initial adsorption occurs randomly up to a coverage of 0.25 ML. After this point islanding occurs until the c(4×2) half-monolayer coverage is reached. Diffuse LEED I(V) analysis has also been used to determined the structure of a low coverage phase. This low coverage phase gives rise to an optimum structure consisting of 70% fcc and 30% hcp threefold hollow site occupation, which contains a large buckling of the first nickel layer. This contrasts with the optimum structure for the ordered, 0.5 ML c(4×2) phase where a 50/50 mix of fcc and hcp site occupation is determined and no buckling is found. These site assignments do not agree with assignments made using vibrational spectroscopy. Our results provide the basis for a new interpretation of the vibrational data allowing us to give a complete picture for the adsorption of NO on Ni{111} at low temperatures.
XPS STUDY OF IN SITU CLEAVED BSCCO
Authors: SHEN T.-H. , GREIG D. , MATTHEW J.A.D. , BEAMSON G. , BALAKRISHNAN G. , LIN C.T. , LIANG W.Y.
Published: November 2004

Single crystal samples of BSCCO were cleaved in ultrahigh vacuum and studied using XPS with a monochromated Al Kα source. The resolution of the instrument is ~0.35 eV which is better than most previous XPS studies of BSCCO. We confirm that the shape of the Cu 2p and O 1s peaks imply multiple states. The samples were heated in situ to drive off O, to study how screening is affected by changes in stoichiometry. Auger parameters were used for this study. The Auger parameters of Bi, Ca, O, and Cu were estimated.
ARXPS-BASED ANALYSIS OF DIFFERENT OXYGEN STATES ADSORBED AT SILVER FOIL
Authors: BUKHTIYAROV V.I. , BORONIN A.I. , BASCHENKO O.A.
Published: November 2004

Atomic oxygen states adsorbed at silver surface have been studied by angle-resolved XPS. It has been shown that all states have different structure of adsorbed layers. This allowed us to conclude that ARXPS followed by depth concentration profile restoration is useful technique for analysis of the adsorbate location with respect to upper substrate layers.
FEASIBILITY OF EXPERIMENTS WITH CIRCULARLY POLARISED LIGHT ON BEAMLINE 4.1 AT THE SRS
Authors: FINETTI P. , ROBINSON A.W. , THORNTON G. , D'ADDATQ S.
Published: November 2004

We present the results of a feasibility study for the upgrading of beamline 4.1 at the SRS to a configuration that allows experiments with circularly polarised light. The upgrading project is based on the well-known property of bending magnets that light emitted out of the storage ring plane is elliptically polarised. The photon flux at the sample and the degree of circular polarisation have been calculated, as a function of the photon energy, for different values of the out-of-plane solid angle from which the light emitted by an ideal bending magnet at the SRS could be collected by beamline 4.1.
THE PHOTODESORPTION OF NO FROM A Pt SURFACE
Authors: HARRIS S. , HOLLOWAY S.
Published: November 2004

Time-dependent quantum wave packets have been used in a model calculation to investigate the photodesorption of an NO molecule from a Pt surface. A hot electron, generated in the substrate by an absorbed photon, may temporarily resonate in an unoccupied NO molecular orbital. If the electron spends enough time in the resonance, then on returning to the electronic ground state, the excited NO can acquire sufficient energy to desorb. The new aspect presented here is to treat the motion of the NO and that of the electron on an equal footing when calculating the photodesorption yield. We have not employed the Born-Oppenheimer approximation, but rather studied the dynamics on potential energy surfaces including both the NO-Pt and electron-Pt interactions.
A SURFACE X-RAY DIFFRACTION STUDY OF THE GROWTH OF ULTRATHIN LAYERS OF Fe ON Cu(001)
Authors: JAMES M.A. , NORRIS C. , NICKLIN C.L. , VAN SILFHOUT R.G. , HOWES P.B. , TURNER T.S.
Published: November 2004

Although it is well known that the γ (fcc) phase of Fe can be stabilised on Cu(001) single crystal substrates, there is still considerable disagreement about the exact nature of the growth mode and the structures that evolve with increasing film thickness. A detailed knowledge of the structure and morphology is essential for a complete understanding of the magnetic properties of ultrathin iron films. Surface X-ray diffraction measurements, recorded in real time during deposition of Fe deposition on Cu(001), are presented. At room temperature, well-defined layer-by-layer growth, with no significant agglomeration of iron, was observed. The specular intensity of the X-ray beam varied parabolically with coverage, as predicted by kinematical theory. Intensity oscillations were observed up to 15 Fe monolayers, at which coverage relaxation to the α (bcc) phase was confirmed. At 85 K the growth is diffusion limited.
IDENTIFYING THE NATURE OF ADSORBED PROPENE ON Cu FILMS USING IR SPECTROSCOPY
Authors: MUNRO S. , RAVAL R.
Published: November 2004

The adsorption of propene on thin copper films was studied using transmission FTIR spectroscopy. At 165 K the propene molecule is found to be molecularly adsorbed as a π-complex on the surface, interacting with the surface via the C=C double bond. The molecular skeleton is oriented largely parallel to the metal surface but with the methyl group tilted away from the surface. No evidence was found for the existence of either the di-σ or the propylidyne species suggesting that the adsorption behavior of propene on copper bears a strong resemblance to that exhibited by ethene.
STM STUDIES OF COEXISTING S-INDUCED STRUCTURES ON Cu(110)
Authors: PARKER T.M. , CONDON N.G. , LINDSAY R. , THORNTON G. , LEIBSLE F.M.
Published: November 2004

Scanning tunneling microscopy (STM) has been used to study the "c(2×2)" and p(5×2) sulphur-induced structures on Cu(110). Images have been obtained of the "c(2×2)" S /p(5×2)S codomain. Using previous results which show that the sulphur related features in "c(2×2)"S domains are above twofold hollow sites,1 we are able to derive, with respect to the underlying substrate, the sulphur adsorption sites for the p(5×2)S phase. We are therefore able to propose a new model for the p(5×2)S phase and speculate as to the structure of the c(8×2)S phase which occurs at higher coverages. These results show the conflict between the accommodation of further S adsorption at higher coverages and the tendency of the S-adatoms to occupy the twofold hollow sites.
Regulation of Ion Transport by the NHERF Family of PDZ Proteins
Authors: Shenolikar Shirish , Voltz James W. , Cunningham Rochelle , Weinman Edward J.
Published: November 2004

NHERFs are the best-studied apical PDZ proteins that are highly expressed in epithelial cells. Molecular and cellular studies over the past decade show that NHERFs regulate the targeting or trafficking of ion transporters and other membrane proteins and transduce physiological and pathophysiological signals that regulate ion homeostasis in mammals.
Surprising Versatility of Na+-Glucose Cotransporters: SLC5
Authors: Wright Ernest M. , Loo Donald D. F. , Hirayama Bruce A. , Turk Eric
Published: November 2004

SLC5 is an ancient gene family with 11 members in the human genome. These membrane proteins have diverse, multiple functions ranging from actively transporting solutes, ions, and water, to channeling water and urea, to sensing glucose in cholinergic neurons. Metabolic disorders have been identified that are associated with congenital mutations in two of the human genes.
The Molecular Physiology of Tight Junction Pores
Authors: Van Itallie Christina M. , Anderson James Melvin
Published: November 2004

Tight junctions form selective barriers that regulate paracellular transport across epithelia. A large family of tetraspanning cell-cell adhesion proteins called claudins create the barrier and regulate electrical resistance, size, and ionic charge selectivity. Study of inherited human claudin diseases and the outcome of the genetic manupulation of claudins in mice, Drosophila, and Caenorhabditis elegans are furthering our understanding of paracellular physiology.
Imaging Takes a Quantum Leap
Authors: Lidke Diane S. , Arndt-Jovin Donna J.
Published: November 2004

Semiconducting nanocrystals, or quantum dots (QDs), have emerged as a new tool in physiological imaging, combining high brilliance, photostability, broad excitation but very narrow emission spectra, and surface chemistry compatible with biomolecular conjugation. In this review, we demonstrate the power of QDs in diverse applications, including long-term in vivo fluorescence imaging.
Resistin Promotes Smooth Muscle Cell Proliferation Through Activation of Extracellular Signal–Regulated Kinase 1/2 and Phosphatidylinositol 3-Kinase Pathways
Authors: Calabro Paolo , Samudio Ismael , Willerson James T. , Yeh Edward T.H.
Published: November 2004

Background—

Resistin, a novel adipokine, is elevated in patients with type 2 diabetes and may play a role in the vascular complications of this disorder. One recent study has shown that resistin has a proinflammatory effect on endothelial cells. However, there is no information on whether resistin could also affect vascular smooth muscle cells (SMCs). Thus, the purpose of this study was to assess whether resistin could induce SMC proliferation and to study the mechanisms whereby resistin signals in SMCs.

Methods and Results—

Human aortic smooth muscle cells (HASMCs) were stimulated with increasing concentrations of resistin for 48 hours. Cell proliferation was induced by resistin in a dose-dependent manner as assessed by direct cell counting. To gain more insights into the mechanism of action of resistin, we investigated the extracellular signal–regulated kinase (ERK) and/or phosphatidylinositol 3-kinase (PI3K) signaling pathways. Transient phosphorylation of the p42/44 mitogen-activated protein kinase (ERK 1/2) occurred after addition of resistin to HASMCs. U0126, a specific inhibitor of ERK phosphorylation, significantly inhibited ERK 1/2 phosphorylation and reduced resistin-simulated proliferation of HASMCs. LY294002, a specific PI3K inhibitor, also significantly inhibited HASMC proliferation after resistin stimulation.

Conclusions—

Our results demonstrate that resistin induces HASMC proliferation through both ERK 1/2 and Akt signaling pathways. The proliferative action exerted by resistin on HASMCs may account in part for the increased incidence of restenosis in diabetes patients.
Dynamin-2 Regulates Oxidized Low-Density Lipoprotein–Induced Apoptosis of Vascular Smooth Muscle Cell
Authors: Kashiwakura Yuji , Watanabe Masami , Kusumi Norihiro , Sumiyoshi Katsuhiko , Nasu Yasutomo , Yamada Hiroshi , Sawamura Tatsuya , Kumon Hiromi , Takei Kohji , Daida Hiroyuki
Published: November 2004

Background—

On exposure to oxidized low-density lipoprotein (oxLDL), vascular cells generally undergo apoptosis, which is one of the major pathogenic factors of atherosclerosis. In this study, we examined the role of dynamin (a crucial GTPase protein in endocytosis) in oxLDL-induced apoptosis of vascular smooth muscle cells (VSMC).

Methods and Results—

After oxLDL stimulation, dynamin-2 colocalized with LOX-1 around the cell surface, as well as oxLDL in the cytoplasm, suggesting that dynamin-2 was involved in scavenger receptor–mediated oxLDL endocytosis. Downregulation of dynamin-2 induced by dynamin-2 dominant negative plasmid (K44A) resulted in a decrease of oxLDL uptake and thereby in a reduction of apoptosis. These data demonstrated that dynamin-2 was involved in oxLDL-induced apoptosis via the oxLDL endocytotic pathway. On the other hand, dynamin-2 wild-type plasmid transfection promoted oxLDL-induced apoptosis without increasing oxLDL uptake. Interestingly, the p53 inhibitor pifithrin-α (PFT) significantly reduced apoptosis promoted by wild-type dynamin-2 (78% reduction compared with the PFT[−] condition). These results indicated that dynamin-2 enhanced oxLDL-induced apoptosis of VSMC by participating in the p53 pathway, probably as a signal transducer. Moreover, we demonstrated that, in advanced plaques of apolipoprotein E
−/−
mice, dynamin-2 expression was often enhanced in apoptotic VSMC, suggesting that dynamin-2 might participate in apoptosis of VSMC even in vivo.

Conclusions—

Our data demonstrated that dynamin-2 at least partially regulated oxLDL-induced apoptosis of VSMC by participating in 2 independent pathways: the oxLDL endocytotic pathway and the p53 pathway. These findings suggest that dynamin-2 may serve as a new research or therapeutic target in vascular disease.
Elastin Degradation and Calcification in an Abdominal Aorta Injury Model
Authors: Basalyga Dina M. , Simionescu Dan T. , Xiong Wanfen , Baxter B. Timothy , Starcher Barry C. , Vyavahare Narendra R.
Published: November 2004

Background—

Elastin calcification is a widespread feature of vascular pathology, and circumstantial evidence exists for a correlation between elastin degradation and calcification. We hypothesized that matrix metalloproteinase (MMP)–mediated vascular remodeling plays a significant role in elastin calcification.

Methods and Results—

In the present studies, we determined that short-term periadventitial treatment of the rat abdominal aorta with low concentrations of calcium chloride (CaCl
2
) induced chronic degeneration and calcification of vascular elastic fibers in the absence of aneurysm formation and inflammatory reactions. Furthermore, the rate of progression of calcification depended on the application method and concentration of CaCl
2
applied periarterially. Initial calcium deposits, associated mainly with elastic fibers, were persistently accompanied by elastin degradation, disorganization of aortic extracellular matrix, and moderate levels of vascular cell apoptosis. Application of aluminum ions (known inhibitors of elastin degradation) before the CaCl
2
-mediated injury significantly reduced elastin calcification and abolished both extracellular matrix degradation and apoptosis. We also found that MMP-knockout mice were resistant to CaCl
2
-mediated aortic injury and did not develop elastin degeneration and calcification.

Conclusion—

Collectively, these data strongly indicate a correlation between MMP-mediated elastin degradation and vascular calcification.
Inhibition of Sphingomyelin Synthesis Reduces Atherogenesis in Apolipoprotein E–Knockout Mice
Authors: Park Tae-Sik , Panek Robert L. , Mueller Sandra Bak , Hanselman Jeffrey C. , Rosebury Wendy S. , Robertson Andrew W. , Kindt Erick K. , Homan Reynold , Karathanasis Sotirios K. , Rekhter Mark D.
Published: November 2004

Background—

In clinical studies, sphingomyelin (SM) plasma levels correlated with the occurrence of coronary heart disease independently of plasma cholesterol levels. We hypothesized that inhibition of SM synthesis would have antiatherogenic effects. To test this hypothesis, apolipoprotein E (apoE)–knockout (KO) mice were treated with myriocin, a potent inhibitor of serine palmitoyltransferase, the rate-limiting enzyme in SM biosynthesis.

Methods and Results—

Diet-admix treatment of apoE-KO mice with myriocin in Western diet for 12 weeks lowered SM and sphinganine plasma levels. Decreases in sphinganine and SM concentrations were also observed in the liver and aorta of myriocin-treated animals compared with controls. Inhibition of de novo sphingolipid biosynthesis reduced total cholesterol and triglyceride plasma levels. Cholesterol distribution in lipoproteins demonstrated a decrease in β-VLDL and LDL cholesterol and an increase in HDL cholesterol. Oil red O staining of total aortas demonstrated reduction of atherosclerotic lesion coverage in the myriocin-treated group. Atherosclerotic plaque area was also reduced in the aortic root and brachiocephalic artery.

Conclusions—

Inhibition of de novo SM biosynthesis in apoE-KO mice lowers plasma cholesterol and triglyceride levels, raises HDL cholesterol, and prevents development of atherosclerotic lesions.
Angiotensin-(1–7) Attenuates Neointimal Formation After Stent Implantation in the Rat
Authors: Langeveld Bas , van Gilst Wiek H. , Tio René A. , Zijlstra Felix , Roks Anton J.M.
Published: November 2004

Angiotensin-(1–7) is an endogenous, biologically active peptide of the renin-angiotensin system with vasodilatory, antithrombotic, and antiproliferative properties. This study examined the effects of angiotensin-(1–7) infusion on neointimal formation after stent placement in the rat. Male Wistar rats underwent stent implantation in the abdominal aorta or sham surgery. Subsequently, an osmotic minipump was placed for angiotensin-(1–7) (24 μg/kg per hour) or saline administration. After 4 weeks, histomorphometric and histological analyses were performed, and the endothelial function was measured in isolated thoracic aortic rings. Stent implantation resulted in equal mean injury scores within the groups. The angiotensin-(1–7)–treated group displayed a significant reduction in neointimal thickness (112±8 versus 141±11 μm;
P
<0.05), neointimal area (0.51±0.05 versus 0.70±0.07 mm
2
;
P
<0.05), and percentage stenosis (10.4±1.0 versus 14.0±1.3%;
P
<0.05) compared with the saline-treated group. Furthermore, angiotensin-(1–7) infusion attenuated the stenting-induced impairment in endothelium-dependent relaxation (42.6±3.0 versus 64.5±6.0% of phenylephrine maximal contraction;
P
<0.001). In conclusion, angiotensin-(1–7) treatment attenuates neointimal formation after stent implantation in the rat, combined with an improvement of endothelial function.
Measurement of Fiber-scale Residual Stress Variation in a Metal-matrix Composite
Authors: Prime Michael B. , Hill Michael R.
Published: November 2004

The crack compliance, or slitting, method was used to measure a localized depth profile of residual stresses in a metal-matrix composite. The composite consisted of a matrix of Kanthal, a Fe–Cr–Al refractory alloy, reinforced with continuous uniaxial tungsten fibers. The stress measurements involved successively deepening a narrow slit between the fibers in the matrix, and measuring the resulting deformations with a surface strain gage. The depth profile of the in-plane residual stress components was determined from the measured strains using an eigenstrain-based extension of the residual stress calculation scheme normally used for slitting measurements. To validate some of the eigenstrain assumptions, the measured residual stresses were compared with the predictions from a thermomechanical finite element model. The model used a mesh of the actual fiber arrangement in the composite specimen rather than the commonly used unit-cell model. Compared to other techniques for measuring residual stresses in composites, the slitting measurements provided spatial resolution to a small fraction of the fiber diameter, which is useful when validating a thermomechanical model. Coincidentally, this is the first reported slitting method measurements of shear residual stresses.
A Investigation into an Advanced Composites Finite Element Explicit Biphase Model – Part I: Elastic Parameters
Authors: Bayandor Javid , Thomson Rodney S. , Scott Murray L.
Published: November 2004

The elastic and damage parameters of the ‘‘biphase’’ composite material and degradation model contained in the explicit finite element code, Pam-Shock, have been investigated in Parts I and II, respectively. The biphase analysis is a relatively new methodology aiming at accurately predicting the complex damage responses of composite structures to dynamic loading conditions. The intricacy of the damage mechanism dealt with hence calls for a broad range of elastic and damage parameters to be defined within the analysis before a solution corresponding to real case scenarios can be achieved. This investigation focuses on the unknown effects of such parameters and has been successful in identifying the significance and sensitivities that the variation of the parameters impose on the predicted outputs. It was established that the variation of some of the parameters, such as Poisson’s ratio, can cause a considerable deviation from the reference run, thus making it imperative to concentrate on deriving accurate empirical values to be used against such material properties within the analysis. A brief tabulated summary demonstrates the strengths and limitations of the model in predicting the response of advanced composite structures to impact events.
An Investigation into an Advanced Composite Finite Element Explicit Biphase Model: Part II – Damage Parameters
Authors: Bayandor Javid , Thomson Rodney S. , Scott Murray L.
Published: November 2004

The effects of damage parameter variations in the explicit finite element ‘‘biphase’’ composite material model were studied. The damage–time history responses of three elements, selected within a sample aerospace composite panel, under dynamic loading conditions were closely studied for fibre damage, matrix volumetric and deviatoric damages, and total damage. Several of the damage parameters were found to be highly sensitive to the slightest parametric variation, imposing considerable deviations to the predicted dynamic responses of the structures under investigation. The paper continues with identifying such parameters and provides a tabulated damage sensitivity reference that enables effective application of the biphase composite model in investigating real-life aerospace composite design problems.
Dynamic Behavior of a Laminated Beam Under the Effect of a Moving Heat Source
Authors: Al-Huniti Naser S.
Published: November 2004

Dynamic thermoelastic behavior of a laminated beam is investigated. The beam is heated by a heating source moving longitudinally. A new dynamic model for a laminated beam is obtained by which the induced displacements and stresses can be computed based on the thermal history and geometry of the beam. The thermal history of the beam, the induced displacements, and the thermal stresses are determined using an analytical–numerical technique based on the Laplace transformation and the Riemann sum approximation. Different symmetric lamination layups are considered. The numerical computations show that the temperature gradients, and hence the induced displacements, and thermal stresses, are affected mainly by the heat source speed, beam inertia, layer combinations, and differences in the thermal and mechanical properties between the materials of the layers.
Slouching Towards New ‘Just’ Wars: The Hegemon after September 11th
Authors: Brunnée Jutta , Toope Stephen J.
Published: November 2004

Twentieth-century international law was in large part a struggle to reduce the evil of war by codifying a restrictive doctrine of ‘just war’. The US Administration under George W. Bush has made concerted efforts to resurrect an expansive doctrine of just war: one rooted in broad moral, rather than restrictive legal, assessments of threats and punishments. Existing rules ask us to pause and inquire whether war is necessary and just. The debate over Iraq laid bare failings in these rules, requiring action. Yet the need to limit resort to war is as great as ever. Legal rules cannot prevent the use of force; nor can they prevent violations that states perceive to be in their fundamental interests. Rather, international law provides a framework against which states’ actions are assessed, and imposes a heavy burden of justification. International law requires more specific, testable claims than can be offered by the rhetoric of evil.
An International Ethics of Evil?
Authors: Abdel-Nour Farid
Published: November 2004

Ethical debates in international relations tend to rely either on the vocabulary of norms or the vocabulary of evil. In an effort to conceive of a richer international ethics, this article explores the possibility of combining the two. Since the vocabulary of norms is indispensable, the question is how to supplement it. The most prevalent conception of evil turns out to be a dangerous and inappropriate supplement, for it posits evil as absolutelynot-self, and as an attribute of foes to be eradicated. The second conception of evil highlights the connections between evil and self. When applied to the international context, this conception encourages self-critical public debates about present and past injustices, helping societies to confront and heal ethnic, racial, and other political wounds. Thus a rich international ethics is best woven out of the vocabulary of norms and the conception of evil as connected-to-self.
Where the Political and the Psychological Meet: Moral Disruption and Children’s Understanding of War
Authors: Rafman Sandra
Published: November 2004

I argue for the inclusion of a moral dimension in the study of children’s responses to loss and trauma in contexts of armed conflict and political violence. In my clinical and research studies, the disruption of a rule-governed moral universe is revealed in the symbolic and verbal representations of both community-based and clinically referred children whose parents have disappeared or been killed in contexts of political violence. Dilemmas related to good and evil, trust and betrayal, protection and aggression, are prevalent in war-affected children’s representations of their traumatic experiences. Not only should more attention be paid to children’s construction of moral narrative in the aftermath of political violence, but also this should be done in conjunction with an examination of the moral narratives embedded in national and cultural ideologies. Following political violence, the child’s search for meaning occurs at the same time that his or her relevant culture(s) or nation(s) are struggling to construct a collective narrative, often in the context of conflicting historical accounts, memories and narratives. Interventions and research addressing the recovery of war-affected children should recognize the interconnectedness of political, social, psychological and moral dimensions of armed conflict and political violence.
Agents, Structures and Evil in World Politics
Authors: Lu Catherine
Published: November 2004

The concept of evil adds complexity to our moral analysis and judgement of social and political phenomena, but the language of evil can be abused, either to exclude persons or groups from our universes of moral obligation, or to subvert fragile international and domestic moral orders and the conditions for human moral agency and responsibility. Despite these dangers the concept of evil is indispensable for identifying acts and states of affairs that violate our most basic moral ideals and expectations. Recognition of evil leads to three distinct but interrelated questions: who is to blame? How could such evil happen? And how can it be prevented from recurring? Answering these questions requires an account of agents, structures and their relationship. Acknowledging that agents and structures are mutually constituted need not absolve agents of moral responsibility; rather, it is vital to refining judgements of moral responsibility, and understanding how various social and political evils occur, as well as how to prevent their future recurrence.
An Elasto-Plastic Stress Analysis in a Polymer–Matrix Composite Beam Supported from Two Ends under Transverse Linearly Distributed Load by Use of Anisotropic Elasticity Theory
Authors: Esendemir Umran
Published: November 2004

An analytical elasto-plastic stress analysis is carried out in a low-density polyethylenethermoplastic beam supported from two ends under transverse linearly distributed load reinforced by Cr–Ni steel fibers analytically. The material is assumed to be perfectly plastic for the elasto-plastic solution. The intensity of the uniform force is chosen at a small value; therefore, the normal stress component y is neglected in the elastic–plastic solution. The expansion of the plastic region and the residual stress component of σx and τxy are determined for 0, 30, 45, 60, and 90 orientation angles. The yielding begins at the upper and lower surfaces of the beam at the same distances from the ends. The intensity of residual stress component of x is maximum at the upper and lower surfaces but residual stress component of τxy is maximum on the x axis of the beam. The strength of the beam is increased by residual stresses.
Hot-Wet Property Characterisation of a High-Temperature Cured Glass–Epoxy Composite in Immersion Environment
Authors: Mahale Santhosh , Rajamani Deepika , Revathi A. , Prakash M. Rajendra , Srihari Shylaja , Rao R. M. V. G. K.
Published: November 2004

The hygrothermal diffusion and degradation behavior of a high-temperature cured glass–epoxy (Epoxy Novolac – EPN) composite system was studied under two environmental conditions (i.e. 323 K and 343 K immersion in distilled water). Samples immersed at 343 K showed higher diffusivity (Dc) value and lower saturation time (tm) than those of 323 K immersion while the maximum moisture content (Mm) remained the same, good Fickian correlation were observed for the composite system. As regards the degradative effects, the glass transition temperature (Tg) of the composite decreased with increased moisture content showing a maximum drop of 30 C at full saturation, while the mechanical properties (ILSS and IPS) of saturated specimens degraded upto 26 and 33% respectively. Further these mechanical properties obtained at 70 C/85%RH test condition showed good correlations with those predicted by a theoretical equation (Chamis et al. An Intergrated Theory for Predicting the Hydrothermo Mechanical Response of Advanced Composite Structural Components, Lewis Research Center, Cleveland, Ohio, NASA Technical Memorandum 73812).
The Insanity of Place
Authors: Scull Andrew
Published: November 2004

This paper uses English examples to scrutinize the complex interrelations of insanity and place over the past three centuries, taking as its starting point the late Erving Goffman’s paper of the same title. From eighteenth-century Bedlam and the emerging trade in lunacy, through the county asylums and licensed madhouses of the nineteenth century to the return of the mentally ill to the ‘community’ in the last half of the twentieth century, the place occupied by insanity has varied sharply, symbolically as well as concretely. These various techniques of containment and damage limitation must be understood as a response to the threats, symbolic and practical, that serious mental illness poses to the social order, at both the micro and macroscopic levels of analysis.
Hermann Joseph Löwenstein’s Dissertation: De Mentis Aberrationibus Ex Partium Sexualium Conditione Abnormi Oriundis(1823)
Authors: Gutmann Philipp
Published: November 2004

In the nineteenth century there was a growing number of publications by physicians who were concerned with the relation between abnormal sexual behaviour or abnormal conditions in the genital sphere and psychiatric disorders. These publications were part of an anti-onanism discourse which had been initiated in the eighteenth century. One of the earliest works in this field was Hermann Joseph Löwenstein’s dissertation De mentis aberrationibus ex partium sexualium conditione abnormi oriundis (1823). Löwenstein was influenced by the ideas of authors who saw the only reason for psychiatric disorders in somatic conditions. The chapters deal with the ‘male sex’, the ‘female sex’ and the ‘hermaphroditismus’. Finally, Löwenstein focuses directly on the mental disorders caused by abnormal sexual disorders, the differences between the sexes and the extent to which one can deduce diseases of the sexual organs from psychic disorders.
Remembering the Future — Utopia, Empire, and Harmony in 21st-Century International Theory
Authors: Callahan William A.
Published: November 2004

Using a comparative approach to international relations theory, this article examines how ancient ideas are being recycled to describe world order in the 21st century. In particular, it provides a thick description of three models of utopia in global politics — Great Harmony and Harmony with difference from China, and Empire from Hardt and Negri. Using an unexplored set of Chinese-language texts, the article first excavates how Communist Party intellectuals in China have been writing about the ancient Confucian ideal of Great Harmony as a way of promoting the People’s Republic of China’s role as a Great Power in the 21st century. Second, it uses Hardt and Negri’s deterritorialized concept of Empire to criticize Great Harmony discourse as a transcendent and state-centric model of world order. Hardt and Negri’s notion of immanent utopia is elaborated in the third section using another set of Chinese texts that describe the flexible methodology of ‘Harmony-with-difference’. The article concludes that Harmony-with-difference provides a practical logic for achieving Hardt and Negri’s immanent utopia. The article contributes two things to international relations theory — (1) using Chineselanguage texts, it broadens the reach of comparative international relations theory and (2) it uses the concept of Empire to challenge Chinese concepts of harmony, while using Chinese theory to elaborate on Hardt and Negri’s utopia. In this way, the article shows how key texts have productively recycled the classical concepts of utopia, empire, and harmony as a way of remembering the future for the 21st century.