bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical aspects of operation Bali assist: initial wound surgery on the tarmac and in flight
Authors: Read David , Ashford Bruce
Published: November 2004

Background:  The explosion of three bombs on 12 October 2002 in Kuta, Bali resulted in mass casualties akin to those seen in war. The aim of the present report is to describe the sequence of events of Operation Bali Assist including triage, resuscitation and initial wound surgery in Bali at Sanglah Hospital in the aeromedical staging facility (ASF), Denpasar airport and the evacuation to Darwin.

Methods:  A descriptive report is provided of the event and includes; resuscitation, anaesthesia, initial burns surgery management including escharotomy and fasciotomy, head injury management and importance of supplies and medical records with a description of the evacuation to Darwin.

Results:  Operation Bali Assist involved five C130 Hercules aircraft and aeromedical evacuation medical and nursing teams managing 66 casualties in the Denpasar area and their evacuation to Royal Darwin Hospital with ketamine the most useful anaesthetic agent and cling film the most useful burns dressing. Twelve procedures were performed at the ASF including seven escharotomies, three fasciotomies and two closed reductions. One escharotomy was performed in flight.

Discussion:  The important lessons learnt from the exercise is the inclusion of a surgeon in the aeromedical evacuation team, the importance of debridement and delayed primary closure, the usefulness of cling film as a burns dressing and the importance of continuous assessment. Future disaster planning exercises need to consider a patient age mix that might be expected in a shopping mall, rather than the young adult encountered in Bali, a more familiar age mix for Australian Defence Force medical staff.
Diagnostic performance of quantitative ultrasound calcaneus measurement in case finding for osteoporosis in Thai postmenopausal women
Authors: Panichkul Suthee , Sripramote Manit , Sriussawaamorn Narongchai
Published: November 2004

Aim:  Dual‐energy X‐ray absorptiometry (DXA) is currently considered the gold standard for the diagnosis of osteoporosis. Quantitative ultrasound (QUS) can be an alternative method that is less expensive, portable, and can be used at a primary care level to indicate osteoporosis in women. The present study aimed to assess the diagnostic performance of QUS calcaneus measurement in a case finding for osteoporosis in Thai postmenopausal women using DXA as a gold standard.

Methods:  Three hundred postmenopausal women, who had not menstruated normally for at least 1 year, were included in the study. To determine the accuracy and reliability of QUS of the calcaneus, calcaneus bone density measurement was carried out using the QUS and left femoral neck bone density was measured using DXA. Bone mass density (BMD) was interpreted as osteoporotic or normal using WHO criteria for determining the performance of QUS. Optimal cut‐off values were determined using a receiver operating characteristic (ROC) curve for diagnosing the osteoporosis cases.

Results:  The number of osteoporosis cases in this study was 107 (35.67%). The sensitivity, specificity, positive and negative predictive values were 39.25%, 91.71%, 72.41%, 73.14%, respectively, when using the T‐score of the WHO criteria as a reference. The positive and negative likelihood ratios were 4.73 and 0.66. When using the ROC curve to determine the optimal cut‐off values, using the stiffness index of the QUS and categorizing age (<65 years and ≥65 years) before conducting the test, sensitivity and specificity were 77.6% and 59.6%, respectively.

Conclusions:  Bone mass density measurement for predicting osteoporosis using QUS had a very low sensitivity and was not good enough to replace the standard tool (DXA).
Retroperitoneal schwannoma bearing at the right vaginal wall
Authors: Inoue Takafumi , Kato Hidenori , Yoshikawa Koji , Adachi Toshisada , Etoh Kohzo , Wake Norio
Published: November 2004

Benign schwannoma commonly arises from schwann cells of the neural sheath. We report a rare case of retroperitoneal schwannoma bearing at the vaginal wall. The tumor was a 7 × 5 × 4‐cm solid mass revealed using several image techniques and diagnosed to be a retroperitoneal tumor preoperatively. The tumor was tightly attached to the vaginal submucosal tissue, so complete surgical resection was difficult. However, an almost complete resection was carried out macroscopically using laparotomy. Histologic and immunohistochemical studies confirmed the diagnosis. The patient has been followed for 18 months after the operation, but there is no evidence of recurrent tumor.
The Self and the Phenomenal
Authors: Dainton Barry
Published: November 2004

As is widely appreciated and easily demonstrated, the notion that we are essentially experiential (or conscious) beings has a good deal of appeal; what is less obvious, and more controversial, is whether it is possible to devise a viable account of the self along such lines within the confines of a broadly naturalistic metaphysical framework. There are many avenues to explore, but here I confine myself to outlining the case for one particular approach. I suggest that we should think of ourselves (or our essential cores) as being composed of experience‐producing systems, and that such systems belong to the same self when they have the capacity to contribute to unified streams of consciousness. The viability of this proposal rests in turn on a particular conception of the structure of consciousness, both at and over time; this conception is defended in the first part of the paper
Economic Diplomacy
Authors: Ponsatí Clara
Published: November 2004

We study bilateral conflicts that affect the welfare of third parties, the stakeholders. The conflict takes the form of a war of attrition and intervention is modeled as the possibility that the stakeholder “aids” the agreement with transfers to the contenders. We characterize the optimal policy when the stakeholder limits its intervention to a unilateral commitment to compensate the contenders if the conflict is resolved, and show that if contenders must be treated equally after agreement, then the optimal policy cannot eliminate the delay in resolving the conflict, and intervention is only advisable when the stakes are high enough. Economic diplomacy is modeled as a three‐player game where the stakeholder is actively involved in the negotiation where transfers are discussed simultaneously with a settlement for the conflict. We prove that, provided that none of the parties involved is too impatient, diplomacy benefits the third party in all conflicts.
Idazoxan effects upon contractile activity in the rat aorta are related to α1 adrenoceptors and L‐type channels
Authors: Serban Dragomir Nicolae , Serban Ionela Lacramioara , Nechifor Mihai
Published: November 2004

Idazoxan is an α2 adrenoceptor antagonist and α1/α2 partial agonist which also blocks imidazoline receptors. Although idazoxan is widely used in pharmacological studies, its intrinsic vasoactive properties could bring about some limitations. Others have shown that in rat aorta contracted by phenylephrine idazoxan induces relaxation and that in rat small arteries it preferentially antagonizes the α1‐mediated response. We further investigated this matter, using the rat aorta and focusing on the endothelium‐independent effects and on L‐type channels. In our study, idazoxan inhibited the contraction induced by phenylephrine, an effect which was stronger in the presence of endothelium, but did not affect the contractions induced by various other agents (high potassium, angiotensin II, prostaglandin F2α). This preferential inhibition was attenuated by 10−4 m, but not by 10−5 m yohimbine, and also reduced by 10−2 m tetraethylammonium and blunted by 10−4 m methoxyverapamil. In concentrations above 10−5 m idazoxan induced weak contractions of the de‐endothelized rings, which were prazosin‐ and methoxyverapamil‐sensitive. Others have suggested that cyclic guanosine monophospate mediates the idazoxan‐induced endothelium‐dependent relaxation, but this is difficult to reconcile with our findings. Potassium efflux could play some role in the direct relaxing effect of idazoxan. The observed idazoxan effects appear as based on action upon α1 receptors, but a direct interaction with L‐type calcium channels could also be taken into consideration.
Effects of venlafaxine on ethanol withdrawal syndrome in rats
Authors: Sağlam Esra , Uzbay I. Tayfun , Kayir Hakan , Çelik Turgay , Beyazyürek Mansur
Published: November 2004

The present study was designed to investigate the effects of venlafaxine, a serotonin and noradrenaline reuptake inhibitor (SNRI), on ethanol withdrawal syndrome in rats. Adult male Wistar rats (187–319 g) were used for the study. Ethanol (7.2%, v/v) was given to rats by a liquid diet for 21 days. Control rats were pair‐fed an isocaloric liquid diet containing sucrose as a caloric substitute to ethanol. Venlafaxine (5, 10, 20 and 40 mg/kg) and saline were injected to rats intraperitoneally just before ethanol withdrawal. After the 2nd, 4th and 6th hour of ethanol withdrawal, rats were observed for 5 min, and withdrawal signs that included locomotor hyperactivity, agitation, stereotyped behaviour and wet dog shakes were recorded or rated. A second series of injections was given at the 6th hour after the first one, and rats were then tested for audiogenic seizures. Venlafaxine produced some inhibitory effects on locomotor hyperactivity, stereotypic behaviours and wet dog shakes. However, a two‐way anova of the data did not indicate any significant effect. It reduced the incidence of the audiogenic seizures at the 6th hour of ethanol withdrawal. Venlafaxine (20 mg/kg) also prolonged the latency of the seizures significantly. Our results suggest that acute venlafaxine treatment has limited beneficial effects on ethanol withdrawal syndrome in rats.
Impact of inter‐individual differences in drug metabolism and pharmacokinetics on safety evaluation
Authors: Dorne J.L.C.M.
Published: November 2004

Safety evaluation aims to assess the dose–response relationship to determine a dose/level of exposure for food contaminants below which no deleterious effect is measurable that is ‘without appreciable health risk’ when consumed daily over a lifetime. These safe levels, such as the acceptable daily intake (ADI) have been derived from animal studies using surrogates for the threshold such as the no‐observed‐adverse‐effect‐level (NOAEL). The extrapolation from the NOAEL to the human safe intake uses a 100‐fold uncertainty factor, defined as the product of two 10‐fold factors allowing for human variability and interspecies differences. The 10‐fold factor for human variability has been further subdivided into two factors of 100.5 (3.16) to cover toxicokinetics and toxicodynamics and this subdivsion allows for the replacement of an uncertainty factor with a chemical‐specific adjustment factor (CSAF) when compound‐specific data are available. Recently, an analysis of human variability in pharmacokinetics for phase I metabolism (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, hydrolysis, alcohol dehydrogenase), phase II metabolism (N‐acetyltransferase, glucuronidation, glycine conjugation, sulphation) and renal excretion was used to derive pathway‐related uncertainty factors in subgroups of the human population (healthy adults, effects of ethnicity and age). Overall, the pathway‐related uncertainty factors (99th centile) were above the toxicokinetic uncertainty factor for healthy adults exposed to xenobiotics handled by polymorphic metabolic pathways (and assuming the parent compound was the proximate toxicant) such as CYP2D6 poor metabolizers (26), CYP2C19 poor metabolizers (52) and NAT‐2 slow acetylators (5.2). Neonates were the most susceptible subgroup of the population for pathways with available data [CYP1A2 and glucuronidation (12), CYP3A4 (14), glycine conjugation (28)]. Data for polymorphic pathways were not available in neonates but uncertainty factors of up to 45 and 9 would allow for the variability observed in children for CYP2D6 and CYP2C19 metabolism, respectively. This review presents an overview on the history of uncertainty factors, the main conclusions drawn from the analysis of inter‐individual differences in metabolism and pharmacokinetics, the development of pathway‐related uncertainty factors and their use in chemical risk assessment.
Framing the Urban: Struggles Over HOPE VI and New Urbanism in a Historic City
Authors: Elliott James R. , Gotham Kevin Fox , Milligan Melinda J.
Published: November 2004

Recent debate over the federal HOPE VI program has focused primarily on whether local applications have met administrative pledges to provide adequate affordable housing to displaced residents of newly demolished public‐housing developments. In this research we take a different direction, examining local processes of political mobilization and strategic framing around a specific type of HOPE VI redevelopment—one that includes construction of a big‐box superstore as part of proposed urban renewal. We argue that the HOPE VI program's formal alignment with New Urbanism created a political opportunity for competing actors to adopt and espouse selective new urbanist themes and imagery to construct and advance divergent visions of what urban space ought to be. Through these framing strategies and struggles, the developer, displaced residents, and opposition groups produced “the City” as a rhetorical object that each then used to advocate specific redevelopment proposals while de‐legitimating competing claims. In this way, the HOPE VI program constitutes more than a new federal housing policy; it offers a new vocabulary for framing and mobilizing collective action in contemporary urban centers.
Changes of vitamin E status of periparturient dairy cows and newborn calves
Authors: KUMAGAI Hajime , CHAIPAN Yot
Published: November 2004

Eleven primiparous Holstein Friesian and their crossbred calves (F1, Japanese Black cattle × Holstein Friesian) and 10 multiparous Holstein Friesian and their Holstein Friesian calves were used to evaluate vitamin E status in periparturient period. Plasma α‐tocopherol (α‐toc) concentrations of the multiparous cows were significantly higher than those of the primiparous cows from 60 days before expected calving to 90 days of lactation (P < 0.05). The multiparous cows had a further decrease in the concentrations of α‐toc and total lipid in plasma to the calving than the primiparous cows. Colostrum α‐toc concentrations in multiparous cows were significantly higher than those of the primiparous cows (P < 0.05). Plasma α‐toc concentrations of calves borne by the multiparous cows were significantly higher than those of the primiparous cows at 5 days of age (P < 0.05). Plasma α‐toc concentrations of calves were highest at 5 and 15 days of age in the calves borne by the multiparous and primiparous cows, respectively, and decreased thereafter till 90 days of age. The higher vitamin E status of multiparous cows over primiparous cows might have reflected nutritional composition in the rations. Their calves afforded higher plasma α‐toc levels after birth because of more α‐toc transfer via placenta and more α‐toc secretion in the colostrums thereafter. Plasma α‐toc concentrations of the calves might have decreased as the calves became dependent upon the solid feed of low vitamin E content.
Does Presidential Rhetoric Matter?  Priming and Presidential Approval
Authors: DRUCKMAN JAMES N. , HOLMES JUSTIN W.
Published: November 2004

The public's approval of the president plays a critical role in determining the president's power and policy‐making success. Scholars and pundits have thus devoted a large amount of attention to explaining the dynamics of presidential approval. Surprisingly, this work has overlooked one of the more important potential forces behind approval—that is, what the president himself says. In this article, we examine the direct impact of presidential rhetoric on approval. We do so by combining a content analysis of the 2002 State of the Union address with both a laboratory experiment and a nationally representative survey. We show that the president can have a substantial effect on his own approval by priming the criteria on which citizens base their approval evaluations. Our results add a new dimension to the study of presidential approval, raise intriguing questions about accountability, and extend work on priming and public opinion by introducing the idea of image priming.
Elections: Tax Cut Versus Lockbox: Did the Voters Grasp the Tradeoff in 2000?
Authors: WATTENBERG MARTIN P.
Published: November 2004

The central issue of the 2000 presidential campaign was how to allocate the projected federal budget surplus. George W. Bush proposed returning much of this revenue via an across‐the‐board reduction in federal income taxes. In contrast, Al Gore argued that most of the surplus should be put aside in a lockbox in order to bolster the Social Security and Medicare programs. This article finds that many voters failed to understand these alternatives, and even among the voters whose opinions matched up with a candidate the correspondence between one's vote and one's opinion was unimpressive.
GENERIC IRREDUCIBLE REPRESENTATIONS OF FINITE-DIMENSIONAL LIE SUPERALGEBRAS
Authors: PENKOV IVAN , SERGANOVA VERA
Published: November 2004

A theory of highest weight modules over an arbitrary finite-dimensional Lie superalgebra is constructed. A necessary and sufficient condition for the finite-dimensionality of such modules is proved. Generic finite-dimensional irreducible representations are defined and an explicit character formula for such representations is written down. It is conjectured that this formula applies to any generic finite-dimensional irreducible module over any finite-dimensional Lie superalgebra. The conjecture is proved for several classes of Lie superalgebras, in particular for all solvable ones, for all simple ones, and for certain semi-simple ones.
K-THEORY AND HOMOTOPY OF CERTAIN GROUPS AND INFINITE GRASSMANN SPACES ASSOCIATED WITH C*-ALGEBRAS
Authors: ZHANG SHUANG
Published: November 2004

We determine, in terms of [Formula: see text] and [Formula: see text], the homotopy groups of certain groups of invertibles and of certain equivalence classes in the infinite Grassmann space on a Hilbert C*-[Formula: see text]-module. These results provide various interpretations of [Formula: see text].
FAST ALGORITHM FOR COMPUTATIONAL STUDY OF DEEP LEVEL PHOTOLUMINESCENCE SPECTRA
Authors: BATOVSKI DOBRI ATANASSOV
Published: November 2004

An algorithm for fast calculation of theoretical deep level photoluminescence (PL) lineshapes is presented. The algorithm can be used for effective comparison with experimental spectra in cases of bulk photoluminescence. The method was expanded and for the cases of deep level photoluminescence in quasi-two and quasi-one dimensional electron systems in semiconductors.
SIMULATIONS OF GLASS FORMING LIQUIDS: WHAT HAS BEEN LEARNED
Authors: MOUNTAIN RAYMOND D.
Published: November 2004

Molecular dynamics simulations of supercooled fluid mixtures of soft-spheres and of Lennard-Jones particles have revealed the existence of a kinetic transition that occurs above the glass transition temperature. This transition appears to be thermodynamic in origin. It is associated with a change in the local mobility of the particles. The basis for these conclusions is discussed.
SIMULATIONS OF FOUR DIMENSIONAL SIMPLICIAL QUANTUM GRAVITY
Authors: CATTERALL S. , KOGUT J. , RENKEN R.
Published: November 2004

We present the results of a high statistics study of a model for four dimensional euclidean quantum gravity based on summing over triangulations.
SCREENING MASSES CLOSE TO THE CHIRAL PHASE TRANSITION
Authors: Boyd G. , Gupta S. , Karsch F. , Laermann E.
Published: November 2004

Evidence indicating that quarks are not confined inside mesons above the chiral transition is presented.
CRITICAL BEHAVIOR OF A PROBABILISTIC LOCAL AND NONLOCAL SITE-EXCHANGE CELLULAR AUTOMATON
Authors: BOCCARA N. , NASSER J. , ROGER M.
Published: November 2004

We study the critical behavior of a probabilistic automata network whose local rule consists of two subrules. The first one, applied synchronously, is a probabilistic one-dimensional range-one cellular automaton rule. The second, applied sequentially, exchanges the values of a pair of sites. According to whether the two sites are first-neighbors or not, the exchange is said to be local or nonlocal. The evolution of the system depends upon two parameters, the probability p characterizing the probabilistic cellular automaton, and the degree of mixing m resulting from the exchange process. Depending upon the values of these parameters, the system exhibits a bifurcation similar to a second order phase transition characterized by a nonnegative order parameter, whose role is played by the stationary density of occupied sites. When m is very large, the correlations created by the application of the probabilistic cellular automaton rule are destroyed, and, as expected, the behavior of the system is then correctly predicted by a mean-field-type approximation. According to whether the exchange of the site values is local or nonlocal, the critical behavior is qualitatively different as m varies.
MULTIGRID METHODS FOR THE COMPUTATION OF PROPAGATORS IN GAUGE FIELDS
Authors: KALKREUTER THOMAS
Published: November 2004

Multigrid methods were invented for the solution of discretized partial differential equations in order to overcome the slowness of traditional algorithms by updates on various length scales. In the present work generalizations of multigrid methods for propagators in gauge fields are investigated. Gauge fields are incorporated in algorithms in a covariant way. The kernel C of the restriction operator which averages from one grid to the next coarser grid is defined by projection on the ground-state of a local Hamiltonian. The idea behind this definition is that the appropriate notion of smoothness depends on the dynamics. The ground-state projection choice of C can be used in arbitrary dimension and for arbitrary gauge group. We discuss proper averaging operations for bosons and for staggered fermions. The kernels C can also be used in multigrid Monte Carlo simulations, and for the definition of block spins and blocked gauge fields in Monte Carlo renormalization group studies. Actual numerical computations are performed in four-dimensional SU(2) gauge fields. We prove that our proposals for block spins are “good”, using renormalization group arguments. A central result is that the multigrid method works in arbitrarily disordered gauge fields, in principle. It is proved that computations of propagators in gauge fields without critical slowing down are possible when one uses an ideal interpolation kernel. Unfortunately, the idealized algorithm is not practical, but it was important to answer questions of principle. Practical methods are able to outperform the conjugate gradient algorithm in case of bosons. The case of staggered fermions is harder. Multigrid methods give considerable speed-ups compared to conventional relaxation algorithms, but on lattices up to 184 conjugate gradient is superior.
A LIGHTWEIGHT APPROACH TO CLIENT-SERVER DBMS PUBLISHING
Authors: RICOTTI MARCELLO , TORRIANI MARCELLO
Published: November 2004

A commercial application of the World-Wide Web concepts is described. It is shown how it is possible to solve a real customer problem in a rapid and cost-effective way by means of the WWW framework. The application has been developed at the Library Center of the University of Bologna (CIB).
EXTREMAL AUTOMATA FOR IMAGE SHARPENING
Authors: HERNANDEZ GONZALO , HERRMANN HANS J. , GOLES ERIC
Published: November 2004

We study numerically the parallel iteration of Extremal Rules. For four Extremal Rules, conceived for sharpening algorithms for image processing, we measured, on the square lattice with Von Neumann neighborhood and free boundary conditions, the typical transient length, the loss of information and the damage spreading response considering random and smoothening random damage. The same qualitative behavior was found for all the rules, with no noticeable finite size effect. They have a fast logarithmic convergence towards the fixed points of the parallel update. The linear damage spreading response has no discontinuity at zero damage, for both kinds of damage. Three of these rules produce similar effects. We propose these rules as sharpening algorithms for image processing.
FAST MAXIMUM ENTROPY ALGORITHM FOR ILL-POSED PROBLEMS
Authors: MESHKOV S.V. , BERKOV D.V.
Published: November 2004

The fast algorithm of the Maximum Entropy (MaxEnt) numerical solution of the linear inverse problem is described. The minimization of a general functional intrinsic to the MaxEnt approach is reduced to an iteration procedure with each step being a constrained least-squares problem (minimization of a quadratic functional with linear inequality constraints). The algorithm is structurally simple and can be assembled from blocks available in standard program libraries. The algorithm is tested on “toy” tasks with exponential kernel, as well as on practical problems of the recovery of the spectral density of strongly correlated quantum systems from the imaginary time Green’s functions obtained by Monte Carlo.
ANOMALOUS ULTRASONIC BEHAVIOR OF Eu-Ba-Cu-O HIGH-Tc SUPERCONDUCTOR
Authors: REDDY R. RAVINDER , REDDY P. VENUGOPAL , REDDI B.V.
Published: November 2004

The ultrasonic longitudinal velocity studies of Eu-Ba-Cu-O high-Tc superconducting sample are carried out over a temperature range of 80–300 K by the pulse transmission technique. Unlike in normal solids, the velocity is found to decrease continuously with decreasing temperature, with an anomaly in the temperature region of 220–155 K. A qualitative explanation for the simultaneous occurrence of both the phenomena of softening in the longitudinal velocity and 220-K anomaly is given.
ABSENCE OF LOCALIZATION IN SCHRÖDINGER OPERATORS WITH ARBITRARY DETERMINISTIC POTENTIAL SEQUENCES
Authors: IGUCHI KAZUMOTO
Published: November 2004

The theory of localization in the Schrödinger operators with arbitrary deterministic potential sequences is studied herein. We classify all the systems of arbitrary substitutions into three categories in terms of the number of constituent atoms, r. If r=1, then all the states in the system belong to only extended states. If r=2, there appears a great variety of the systems on which the localization depends, where some systems show the transition between the extended and the critical states. On the other hand, if r≥3, then there is the universal criticality of the spectrum — all the states in the spectrum belong to only critical states, where the wave function is self-similar or fractal. Surprisingly, this result does not depend on any substitution scheme. Thus, the localization is absent in OUT systems.
QUANTUM GROUPS AND VON NEUMANN THEOREM
Authors: IORIO ALFREDO , VITIELLO GIUSEPPE
Published: November 2004

We discuss the q-deformation of Weyl-Heisenberg algebra in connection with the von Neumann theorem in quantum mechanics. We show that the q-deformation parameter labels the Weyl systems in quantum mechanics and the unitarily inequivalent representations of the canonical commutation relations in quantum field theory.
EFFECT OF ZINC OXIDE ON THE BAND GAP OF CADMIUM–ZINC–PHOSPHATE GLASSES
Authors: BILAL M. SHAKEEL , AHMED M. ASHFAQ , CHAUDHRY M. ASHRAF , ALTAF M.
Published: November 2004

The fundamental absorption edges of cadmium–zinc–phosphate glass samples were measured in the UV visible wavelength region of the spectrum by photoabsorption method. It is found that the optical band gaps of these glasses are composition-dependent and occur at a photon energy in the range 2.85–3.33 eV. The value of the optical band gaps enhances with ZnO content. The absorption coefficient depicts an exponential dependence on photon energy for the glass samples reported in this communication.
THERMOELECTRIC POWER OF SUPERCONDUCTORS IN CONDITIONS OF OPTICALLY INDUCED BRANCH IMBALANCE
Authors: GALOYAN N. A. , GULIAN A. M.
Published: November 2004

Linear response of a superconductor on a temperature gradient is considered assuming an imbalance between electron and hole populations. Nonequilibrium contribution to thermopower is derived for gapless superconductors in a universal form. As a specific example for finite-gap superconductors, a thermopower under the influence of electromagnetic radiation is calculated.
EFFECTIVE P, T RESTORATION IN CHERN–SIMONS SUPERCONDUCTIVITY
Authors: MANDAL S. S. , RAMASWAMY S. , RAVISHANKAR V.
Published: November 2004

We present an analysis of the finite temperature Chern–Simons superconductivity model within the mean field framework. Using analytical and numerical means we compute the changes in the magnetic susceptibility, conductivity, the dielectric constant, and the specific heat as the temperature is increased. Over a narrow range of temperatures the properties of the system show a smooth transition to the normal state. Accompanying this is the near vanishing of the off-diagonal conductivity, signifying the effective restoration of parity and time reversal symmetries.
EFFECTIVE INTERACTIONS OF PLANAR FERMIONS IN A STRONG MAGNETIC FIELD — THE EFFECT OF LANDAU LEVEL MIXING
Authors: RAY RASHMI , GAT GIL
Published: November 2004

We obtain expressions for the current operator in the lowest Landau level (L.L.L.) field theory, where higher Landau level mixing due to various external and interparticle interactions is systematically taken into account. We consider the current operators in the presence of electromagnetic interactions, both Coulomb and time-dependent, as well as local four-Fermi interactions. The importance of Landau level mixing for long range interactions is especially emphasized. We also calculate the edge current for a finite sample.
GEOMETRICAL SCALING IN THE BETHE LATTICE
Authors: DE PÁDUA ANTÔNIO , DE MIRANDA-NETO J. A. , MORAES FERNANDO
Published: November 2004

By embedding the Bethe lattice in a non-Euclidean hyperbolic surface, the hyperbolic plane ℍ2, we are able to associate well-defined geometrical features to its structure. This fact induces the study of geometrical scaling properties on the ramified pseudolattice; we analyze the growth behavior of volume and surface sites for the geometrical structure and compare it with its purely topological counterpart. The results may be applied to amorphous solids modeling and to the study of starbust dendrimers.
SPIN AND CHARGE PERSISTENT CURRENTS IN METALLIC RING WITH IMPURITY
Authors: ZVYAGIN A. A. , KARNAUKHOV IGOR N.
Published: November 2004

Quantum topological effects like Aharonov–Bohm and Aharonov–Casher effects in the metallic ring with a localized impurity are studied. The impurity couples with the conduction electrons by exchange and correlated hybridized interactions. It is shown that the impurity changes the charge and spin persistent current oscillations (the magnitudes and the periods) in contrast with the normal metal situation.
DIFFUSION PROCESSES AND COHERENT STATES
Authors: DE MARTINO SALVATORE , DE SIENA SILVIO , VITIELLO GIUSEPPE , ILLUMINATI FABRIZIO
Published: November 2004

It is shown that uncertanity relations, as well as coherent and squeezed states, are structural properties of stochastic processes with Fokker–Planck dynamics. The quantum mechanical coherent and squeezed states are explicitly constructed via Nelson stochastic quantization. The method is applied to derive new minimum uncertainty states in time-dependent oscillator potentials.
LOW TEMPERATURE ELASTIC BEHAVIOR OF POTASSIUM-DOPED Bi-2212 SINGLE PHASE HIGH Tc SUPERCONDUCTORS
Authors: KRISHNA B. GOPALA , REDDY R. RAVINDER , REDDY P. VENUGOPAL , SURYANARAYANA S. V.
Published: November 2004

A single phase Bi-2212 and two potassium-doped Bi-2212 samples have been prepared by the solid state reaction method. After the usual characterisation, the ultrasonic longitudinal velocity measurements of all the samples over a temperature range of 80–300 K were undertaken by the pulse transmission technique. The longitudinal velocity of the undoped sample is found to vary in an anomalous way followed by a maximum at 140 K. On the other hand, in the case of the two K-doped ones, the velocity is found to vary with temperature in a normal way up to 120 K followed by a maximum at 105 and 100 K respectively. A qualitative explanation for the observed behavior in all the three cases is given.
SCALING BEHAVIOR IN THE TEMPERATURE DEPENDENCE OF THE MIXED STATE RESISTIVITY IN YBCO SYSTEM: NUMERICAL SIMULATION
Authors: DONG JINMING , WANG Z. D.
Published: November 2004

Taking into account the thermal fluctuation effect, we have carried out numerical simulations of the single vortex dynamics in the presence of random pinning potential for YBCO system. The scaling behavior in the temperature dependence of the resistivity near a characteristic temperature T p is found, and its exponent is equal to 5.8 ± 0.2. Comparisons of our numerical results with the experimental measurements and the vortex glass model have been made.
PHOTOEMISSION STUDY OF PURE AND Cs-INTERCALATED VSe2
Authors: STARNBERG H.I. , BRAUER H.E. , NILSSON P.O. , HOLLEBOOM L.J. , HUGHES H.P.
Published: November 2004

We report photoemission studies of the valence band structure of VSe 2 and of VSe2 intercalated with Cs. Pure VSe 2 showed significant band dispersion both perpendicular and parallel to the layers, i.e. the valence band of VSe 2 is 3D in character, confirming self-consistent LAPW band structure calculations. After Cs intercalation the perpendicular band dispersion vanished, while that parallel to the layers remained, showing that the valence band structure had become 2D. The observed changes go far beyond the rigid band model, but are largely understandable in terms of intercalation-induced decoupling of the VSe 2 layers, and charge transfer from the Cs.
THE GENERALIZATION OF SLATER’S AND MARVIN’S INTEGRALS AND THEIR REPRESENTATIONS BY MEANS OF APPELL’S FUNCTIONS F2(x, y)
Authors: TARASOV V.F.
Published: November 2004

The paper deals with a new method of studying Slater’s integral Rk(ab, cd) and Marvin’s integrals 3Rk(ab, cd) and 3Dk(ab, cd) and their generalizations that are widely used in the theory of atomic spectra. We introduce three new definitions of the radial integrals [Formula: see text] and [Formula: see text] with ν - µ=1, 3, 5, … , µ≥0 (even), which generalize Slater’s and Marvin’s integrals. The first and the second integrals with the kernels [Formula: see text] and [Formula: see text], respectively, are represented by means of Appell’s functions F2(x, y). The kernel [Formula: see text] for the third integral may have the form [Formula: see text] respectively, for values [Formula: see text]
DEFECT METASTABILITY IN HYDROGEN PASSIVATED POLYCRYSTALLINE SILICON
Authors: NICKEL N.H. , JACKSON W.B. , JOHNSON N.M.
Published: November 2004

A comprehensive review is presented for the defect passivation and the light-induced metastability in fine grain polycrystalline silicon (poly-Si). The passivation kinetics of grain boundary defects were examined by electron spin resonance and secondary ion mass spectrometry measurements. The spin density decreases to a residual value which strongly depends on the passivation temperature and a further low-temperature anneal reduces the spin density to N S =2.2×1016 cm −3. Illumination with white light produces additional dangling bond defects which are metastable and can be removed by an anneal at moderate temperatures. The light-induced degradation decreases with repeated illumination and annealing cycles and is restored upon re-exposure to monatomic H. Our results provide the strongest evidence to date that hydrogen is responsible for the metastability in both poly-Si:H and hydrogenated amorphous silicon.
REAL SPACE IMAGING OF SURFACES BY MEANS OF BACKSCATTERED ELECTRONS
Authors: Erbudak M. , Hochstrasser M. , Wetli E.
Published: November 2004

Secondary electron imaging (SEI) is presented as a new method which allows the investigation of the near surface structure in real time. SEI is based on the observation that electrons backscattered from surfaces in the keV range show a strong enhancement of intensity along directions defined by atomic rows. The spatial imaging of such electrons reveals the symmetry of near surface regions in real space. Three-dimensional views of the solid are readily obtained which makes this method ideally suited for the study of any material system where there is a change of symmetry. SEI is especially useful for the investigation of surfaces with short range order, such as those with submonolayer coverages of growing films, and of quasicrystals possessing only rotational long range order.
EFFECT OF γ RADIATION ON SOME PHYSICAL PROPERTIES OF THE SPINEL FERRITE SYSTEM Ni0.65Zn0.35CuxFe2−xO4
Authors: TERRA F.S.
Published: November 2004

X-ray diffraction analysis, electrical resistivity measurements at room temperature, and differential thermal analysis (DTA) were carried out for γ-irradiated Ni 0.65 Zn 0.35 Cu xFe2−x O 4 spinel ferrite samples. It was found that the lattice parameter decreased, i.e. the theoretical density increased, while the electrical resistivity decreased. From the DTA analysis there is an endothermic peak at 100–130º C due to internal stress created by γ radiations as a result of lattice defects formation.
EVIDENCE FOR THE EXISTENCE OF 90º CRYSTAL DOMAINS IN 1212 PbSrYCaCuO SINGLE CRYSTALS
Authors: JIN H. , CHEN Z.J. , CAO L.Z. , ZHOU G.E. , JIA Y.B.
Published: November 2004

Single crystals of pure phase 1212 with dimensions up to 5×4×3 mm 3 have been successfully grown from a starting composition of Pb 0.5 Sr 2.5 Y 0.75 Ca 0.25 Cu 2 O x by the spontaneous nucleation method. 1212 single crystals have an orthorhombic structure with a=5.466 Å, b=5.378 Å, and c=11.784 Å. X-ray transmission scanning measurements were first carried out for as-grown 1212 single crystals. The measurements indicated the existence of many crystal domains formed by the rotation by 90º of one domain relative to another. The sizes of the domains are relatively large as estimated by θ−2θ scans for various conditions.
ON THE EXISTENCE OF WEAK SOLUTIONS TO A SYSTEM OF STATIONARY SEMICONDUCTOR EQUATIONS WITH AVALANCHE GENERATION
Authors: FREHSE J. , NAUMANN J.
Published: November 2004

This paper is concerned with the stationary drift-diffusion equations of semiconductor theory involving recombination-generation of carriers due to particle transition, and pure generation by impact ionization (avalanche generation). We establish the existence of a weak solution to the mixed boundary value problem for the system of PDEs under consideration. In the proof we combine an approximation argument with some estimates based on a positivity property of the recombination-generation term.
AN ADAPTIVE FINITE ELEMENT METHOD WITH EFFICIENT MAXIMUM NORM ERROR CONTROL FOR ELLIPTIC PROBLEMS
Authors: ERIKSSON KENNETH
Published: November 2004

A posteriori and a priori error estimates are derived for a finite element discretization method applied to an elliptic model problem. The underlying partitions need not be quasi-uniform and can be highly graded; only a certain weak, local mesh regularity is assumed. The error is bounded in terms of the local mesh size and the local regularity of the solution and data. An adaptive algorithm is designed for automatic control of the discretization error in the maximum norm. The error control is proved to be both reliable and efficient.
KALB-RAMOND VORTICITY VARIATIONAL FORMULATION OF RELATIVISTIC PERFECTLY CONDUCTING FLUID THEORY
Authors: CARTER Brandon
Published: November 2004

Use of a Kalb-Ramond type formulation is shown to allow standard perfect (electrically or neutrally) conducting fluid theory to be described by a variation principle in which the relevant vorticity forms act as independent convective field variables, a feature that is potentially useful for the purpose of constructing more general theories to allow for the macroscopic effect of vortex quantisation in superfluids.
CHANGES OF TOPOLOGY AND CHANGES OF SIGNATURE
Authors: GIBBONS G W
Published: November 2004

Some recent ideas about topology and signature changing spacetimes are described. If spacetime is everywhere Lorentzian but non-orientable, one can sometimes avoid closed timelike curves, but one must must consider pinors rather than spinors. One finds that there is now an important distinction between signature (+ + + −) and (− − − +). In some cases one signature may be excluded and the other allowed. Topology changing spacetimes with domains of non-Lorentzian signature are considered. These domains may be Riemannian or Kleinian (+ + − −). It is argued that our present signature, together with the idea of time must have arisen as the consequence of physical processes. This emergence of the idea of time is also connected with the origin of the complex numbers in Quantum Mechanics which should also be regarded as the consequence of the evolution of the universe.
EXTENSIONS OF 2D GRAVITY
Authors: Sevrin Alexander
Published: November 2004

After reviewing some aspects of gravity in two dimensions, I show that non-trivial embeddings of sl(2) in a semi-simple (super) Lie algebra give rise to a very large class of extensions of 2D gravity. The induced action is constructed as a gauged WZW model and an exact expression for the effective action is given.
ON A NEW METHOD FOR COMPUTING TRACE ANOMALIES
Authors: BASTIANELLI FIORENZO
Published: November 2004

I describe a new method for computing trace anomalies in quantum field theories which makes use of path-integrals for particles moving in curved spaces. After presenting the main ideas of the method, I discuss how it is connected to the first quantized approach of particle theory and to heat kernel techniques.
LIGHT AND GRAVITATION: ABOUT MICHELL’S THEORY
Authors: EISENSTAEDT JEAN
Published: November 2004

Through the reception of Michell’s theory on the influence of gravitation on the propagation of light, I shortly review the main developments on the subject. It appears that Einstein was aware of the idea of the bending of light in a Newtonian context.
NON-FLAT PERTURBATION SPECTRA AND LARGE SCALE STRUCTURE FORMATION
Authors: MÜLLER VOLKER
Published: November 2004

It is shown that fourth-order-gravity with a scalar field leads naturally to double inflation models. If both inflationary episodes are disconnected by a stage of power law expansion, we get a primordial inflation spectrum with a break in the power possibly relevant for the formation of large scale structures in the universe.
DARK MATTER AND DISSIPATION
Authors: PAVON DIEGO , ZIMDAHL WINFRIED
Published: November 2004

The uncertainty about the current values of the observational parameters leaves ample room for a bulk dissipative stress on cosmic scales which, we argue, may be ascribed to the presence of dark matter. As a byproduct the constraint 2q0<Ω0 is obtained.
EFFECTS OF DRAG FORCE ON COSMIC STRINGS
Authors: SAKELLARIADOU M.
Published: November 2004

We study the evolution of cosmic strings taking into account the drag force due to the surrounding radiation. We consider small perturbations on straight strings, oscillations and small perturbations on circular loops. For straight strings, perturbations whose co-moving scale crosses the horizon before cosmological time t* — when the drag force switches off — will be exponentially suppressed. Loops with size much smaller than t* will be approximately circular at the time when they start the relativistic collapse. We investigate the possibility that such loops will form black holes. We find that the number of black holes which are formed through this process is well bellow present observational limits, so this does not give any lower or upper bounds on the string tension.
SEARCHING FOR QUANTUM GRAVITY EFFECTS IN COSMOLOGICAL DATA
Authors: SALOPEK D.S.
Published: November 2004

If the inflationary scenario describes our Universe, then it is possible that quantum gravity phenomena could be observed in anisotropy experiments of the microwave background as well as in galaxy clustering data. Primordial gravitational radiation arising from inflation is a consequence of quantum gravity. Moreover, the wavefunction of the Universe is currently being measured by the COBE satellite. A non-Gaussian distribution could be a signature of nonlinear quantum gravity. In fact, the excess power power seen in the APM survey of galaxies can arise from non-Gaussian initial conditions generated during inflation.
QUANTIZATION AND THE ISSUE OF TIME FOR VARIOUS TWO-DIMENSIONAL MODELS OF GRAVITY
Authors: STROBL THOMAS
Published: November 2004

It is shown that the models of 2D Liouville Gravity, 2D Black Hole- and R2-Gravity are embedded in the Katanaev-Volovich model of 2D NonEinsteinian Gravity. Different approaches to the formulation of a quantum theory for the above systems are then presented: The Dirac constraints can be solved exactly in the momentum representation, the path integral can be integrated out, and the constraint algebra can be explicitely canonically abelianized, thus allowing also for a (superficial) reduced phase space quantization. Non-trivial dynamics are obtained by means of time dependent gauges. All of these approaches lead to the same finite dimensional quantum mechanical system.
COSMOLOGY WITH ADIABATIC MATTER CREATION
Authors: ZIMDAHL WINFRIED , PAVÓN DIEGO
Published: November 2004

The standard Friedmann-Lemaître-Robertson-Walker (FLRW) model is modified to include particle production processes. The influence of these processes on the dynamics of the early Universe is investigated. We argue that a sufficiently high creation rate may give rise to an inflationary period. A stability analysis about this background yields growing energy density perturbations during the de Sitter stage.
REALITY CONDITIONS FOR LORENTZIAN AND EUCLIDEAN GRAVITY IN THE ASHTEKAR FORMULATION
Authors: MENA MARUGÁN GUILLERMO A.
Published: November 2004

Using Ashtekar variables, we analyze Lorentzian and Euclidean gravity in vacuum up to a constant conformal transformation. Keeping unaltered the symplectic structure in the full theory of complex gravity, we prove that the reality conditions are invariant under a Wick rotation of the time, and show that the compatibility of the algebra of commutators and constraints with the involution defined by the reality conditions restricts the possible values of the conformal factor to be either real or purely imaginary. In the first case, one recovers real Lorentzian general relativity. For purely imaginary conformal factors, the classical theory can be interpreted as real Euclidean gravity. The reality conditions associated with this Euclidean theory demand the hermiticity of the Ashtekar connection, but the densitized triad is represented by an anti-Hermitian operator. We also demonstrate that the Euclidean and Lorentzian sets of reality conditions lead to inequivalent quantizations of full general relativity. This conclusion also holds in the geometrodynamic formulation. As a consequence, it seems impossible to obtain Lorentzian physical predictions from the quantum theory constructed with the Euclidean reality conditions.
DARK MATTER IN THE GALAXY
Authors: WYSE ROSEMARY F.G.
Published: November 2004

I will first review the evidence that our Milky Way Galaxy contains a substantial amount of dark matter, and what is known about the spatial distribution of this material, from rotation curve decompositions and from analysis of the vertical force law in the solar neighborhood. All data are consistent with no significant unidentified material in the Galactic disk, requiring that the dark matter be in a spatially-extended distribution. Brown dwarfs, or sub-stellar objects, are often discussed as possible dark-matter candidates, especially in view of the implication from nucleosynthesis calculations that dark baryons exist. The somewhat discour-aging status of recent searches for brown dwarfs is reviewed, together with present understanding of the low-mass stellar initial mass function. I discuss a long-term survey of the motions and chemical abundances of Galactic stars which will provide constraints on the Galactic potential well and the history of Galaxy formation.