bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling Laws From Statistical Data and Dimensional Analysis
Authors: Mendez Patricio F. , Ordóñez Fernando
Published: August 2005

Scaling laws provide a simple yet meaningful representation of the dominant factors of complex engineering systems, and thus are well suited to guide engineering design. Current methods to obtain useful models of complex engineering systems are typically ad hoc, tedious, and time consuming. Here, we present an algorithm that obtains a scaling law in the form of a power law from experimental data (including simulated experiments). The proposed algorithm integrates dimensional analysis into the backward elimination procedure of multivariate linear regressions. In addition to the scaling laws, the algorithm returns a set of dimensionless groups ranked by relevance. We apply the algorithm to three examples, in each obtaining the scaling law that describes the system with minimal user input.
Using Series-Series Iwan-Type Models for Understanding Joint Dynamics
Authors: Quinn D. Dane , Segalman Daniel J.
Published: August 2005

In mechanical assemblies, the energy loss induced by joints and interfaces can account for a significant portion of the overall structural dissipation. This work considers the dynamical behavior of an elastic rod on a frictional foundation as a model for the dissipation introduced by micro-slip in mechanical joints. In a quasi-static loading limit, the deformation of the rod and hence the frictional dissipation can be solved in closed form. The resulting model is a continuum model of series arrangements of parallel Jenkins elements. For a general class of normal load distributions, the resulting energy loss per forcing cycle follows a power-law and is qualitatively similar to observed experimental findings. Finally, these results are compared with those obtained from a discrete formulation of the rod including inertial effects. For loading conditions that are consistent with mechanical joints, the numerical results from the discrete model are consistent with the closed form predictions obtained in the quasistatic limit.
Numerical Analysis of Nanotube-Based NEMS Devices—Part I: Electrostatic Charge Distribution on Multiwalled Nanotubes
Authors: Ke Changhong , Espinosa Horacio D.
Published: August 2005

The charge distribution on the surface of a biased conductive, finite-length, cylindrical nanotube, free standing above an infinite grounded plane, is investigated. The diameter range of the cylinder tube under study is 20–60 nm, which is much larger than the screening length, meaning the quantum and statistical effects on the charge distribution are negligible. The relationship between the charge distribution and the geometry of the nanotube is examined in detail by classical electrostatics using full three-dimensional numerical simulations based on the boundary element method. A model of the concentrated charge at the end of nanotubes is proposed. The charge distribution for a clamped cantilever nanotube is also computed and discussed. The findings here reported are of particular usefulness in the design and modeling of electrostatic actuated nanotube/nanowire based nano-electromechanical systems.
On the Buckling of a Circular Plate on an Elastic Foundation
Authors: Wang C. Y.
Published: August 2005

The buckling of a circular plate on an elastic foundation is studied analytically. The buckling mode may not be axisymmetric as previously assumed.
Model Order Reduction of Viscously Damped Vibration Systems Using Accelerated Iterative Dynamic Condensation
Authors: Qu Zu-Qing , Selvam Panneer
Published: August 2005

An accelerated iterative dynamic condensation method for the model order reduction of vibration systems with viscous damping is proposed. A group of governing equations for dynamic condensation matrix are derived from the eigenvalue equations defined in the state space. Two iterative schemes for solving these governing equations are provided. Based on different state space formulations, two more groups of governing equations are developed. A comparison of the present method with three iterative approaches proposed recently is provided. The present approach is implemented into two practical vibration systems, a tall building with one tuned mass damper and a floating raft isolation system. The results show that the proposed method has much higher accuracy than the other three approaches while the computational effort is almost the same.
Dynamics of Plate Generated by Moving Harmonic Loads
Authors: Sun Lu
Published: August 2005

A thin plate resting on a Winkler elastic foundation subject to a moving harmonic load can be used as the model for highway and airport pavement under moving vehicle load and many other applications. The study of dynamic response of the plate thus becomes very important. In this paper we study the dynamic displacement of a plate caused by a moving harmonic line and point load. The solution is represented by the convolution of dynamic Green’s function of plate. An approximate relationship between critical load velocity and critical frequency is established analytically. It is found that the maximum displacement response occurs at the center of the moving load and travels at the same speed with the load.
Robert Andrews Millikan: Recipient of the 1940 Oersted Medal for Notable Contributions to the Teaching of Physics
Authors: Roller Duane
Published: August 2005

The American Association of Physics Teachers has made the fifth of its annual awards for notable contributions to the teaching of physics to Robert Andrews Millikan, Director of the Norman Bridge Laboratory of Physics and Chairman of the Executive Council of the California Institute of Technology. The addresses of recommendation and presentation were made by Professor Duane Roller and Professor Richard M. Sutton in a ceremony held on December 30, 1940, during the tenth annual meeting of the Association at Philadelphia, Pennsylvania. In Professor Millikan's absence, the medal was accepted on his behalf by Dr. Carl D. Anderson, and the address of acceptance prepared by Professor Millikan was read by Professor Frederic Palmer.
Formation of Regulatory Patterns During Signal Propagation in a Mammalian Cellular Network
Authors: Ma'ayan Avi , Jenkins Sherry L. , Neves Susana , Hasseldine Anthony , Grace Elizabeth , Dubin-Thaler Benjamin , Eungdamrong Narat J. , Weng Gehzi , Ram Prahlad T. , Rice J. Jeremy , Kershenbaum Aaron , Stolovitzky Gustavo A. , Blitzer Robert D. , Iyengar Ravi
Published: August 2005

We developed a model of 545 components (nodes) and 1259 interactions representing signaling pathways and cellular machines in the hippocampal CA1 neuron. Using graph theory methods, we analyzed ligand-induced signal flow through the system. Specification of input and output nodes allowed us to identify functional modules. Networking resulted in the emergence of regulatory motifs, such as positive and negative feedback and feedforward loops, that process information. Key regulators of plasticity were highly connected nodes required for the formation of regulatory motifs, indicating the potential importance of such motifs in determining cellular choices between homeostasis and plasticity.
Structural Basis for the Activation of Cholera Toxin by Human ARF6-GTP
Authors: O'Neal Claire J. , Jobling Michael G. , Holmes Randall K. , Hol Wim G. J.
Published: August 2005

The
Vibrio cholerae
bacterium causes devastating diarrhea when it infects the human intestine. The key event is adenosine diphosphate (ADP)–ribosylation of the human signaling protein G
Sα
, catalyzed by the cholera toxin A1 subunit (CTA1). This reaction is allosterically activated by human ADP-ribosylation factors (ARFs), a family of essential and ubiquitous G proteins. Crystal structures of a CTA1:ARF6-GTP (guanosine triphosphate) complex reveal that binding of the human activator elicits dramatic changes in CTA1 loop regions that allow nicotinamide adenine dinucleotide (NAD
+
) to bind to the active site. The extensive toxin:ARF-GTP interface surface mimics ARF-GTP recognition of normal cellular protein partners, which suggests that the toxin has evolved to exploit promiscuous binding properties of ARFs.
Khipu Accounting in Ancient Peru
Authors: Urton Gary , Brezine Carrie J.
Published: August 2005

Khipu are knotted-string devices that were used for bureaucratic recording and communication in the Inka Empire. We recently undertook a computer analysis of 21 khipu from the Inka administrative center of Puruchuco, on the central coast of Peru. Results indicate that this khipu archive exemplifies the way in which census and tribute data were synthesized, manipulated, and transferred between different accounting levels in the Inka administrative system.
Pre-Unfolding Resonant Oscillations of Single Green Fluorescent Protein Molecules
Authors: Baldini Giancarlo , Cannone Fabio , Chirico Giuseppe
Published: August 2005

Fluorescence spectroscopy of a green fluorescent protein mutant at single-molecule resolution has revealed a remarkable oscillatory behavior that can also be driven by applied fields. We show that immediately before unfolding, several periodic oscillations among the chemical substates of the protein chromophore occur. We also show that applied alternating electric or acoustic fields, when tuned to the protein characteristic frequencies, give rise to strong resonance effects.
FD, a bZIP Protein Mediating Signals from the Floral Pathway Integrator FT at the Shoot Apex
Authors: Abe Mitsutomo , Kobayashi Yasushi , Yamamoto Sumiko , Daimon Yasufumi , Yamaguchi Ayako , Ikeda Yoko , Ichinoki Harutaka , Notaguchi Michitaka , Goto Koji , Araki Takashi
Published: August 2005

FLOWERING LOCUS T
(
FT
) is a conserved promoter of flowering that acts downstream of various regulatory pathways, including one that mediates photoperiodic induction through
CONSTANS
(
CO
), and is expressed in the vasculature of cotyledons and leaves. A bZIP transcription factor, FD, preferentially expressed in the shoot apex is required for FT to promote flowering. FD and FT are interdependent partners through protein interaction and act at the shoot apex to promote floral transition and to initiate floral development through transcriptional activation of a floral meristem identity gene,
APETALA1
(
AP1
).
FT
may represent a long-distance signal in flowering.
The Gap Between Golgi and Cajal
Authors: Jones Edward
Published: August 2005

Nerve Endings
. The Discovery of the Synapse.
By Richard Rapport
. Norton, New York, 2005. 240 pp. $23.95, C$33. ISBN 0-393-06019-5.

Writing for a broad audience, the author describes the researches of Santiago Ramón y Cajal and Camillo Golgi that culminated in the discovery of the synapse.
HEAVY FLAVORS
Authors: ROODMAN AARON
Published: August 2005

Recent results on Heavy Flavor decays are reviewed. Many new results on rare decays, primarily from the B -Factory experiments BABAR and Belle are presented. Decays are classified according to their hadronic structure, and the theoretical issues surrounding the strong interaction effects are discussed. Special attention is given to more theoretically clean measurements.
HOW TO POPULARIZE PARTICLE PHYSICS
Authors: SIMMONS ELIZABETH H.
Published: August 2005

This article reviews why efforts to popularize particle physics are so important, offers advice on maximizing the impact and minimizing the effort involved in your own outreach endeavors, and supplies examples of existing effective programs. Readers are urged to make the 2005 World Year of Physics a focus of their current efforts in education and public outreach.
Computing in High Energy Physics
Authors: Fisk Ian M.
Published: August 2005

In this review, the computing challenges facing the current and next generation of high energy physics experiments will be discussed. High energy physics computing represents an interesting infrastructure challenge as the use of large-scale commodity computing clusters has increased. The causes and ramifications of these infrastructure challenges will be outlined. Increasing requirements, limited physical infrastructure at computing facilities, and limited budgets have driven many experiments to deploy distributed computing solutions to meet the growing computing needs for analysis reconstruction, and simulation. The current generation of experiments have developed and integrated a number of solutions to facilitate distributed computing. The current work of the running experiments gives an insight into the challenges that will be faced by the next generation of experiments and the infrastructure that will be needed.
MEASUREMENT OF ANTI-NEUTRINO SPECTRAL DISTORTION BY KAMLAND
Authors:   for the KamLAND Collaboration., Decowski Michal Patrick
Published: August 2005

The KamLAND experiment uses reactor anti-neutrinos to study the solar neutrino oscillation parameters. KamLAND recently updated the reactor neutrino measurement, with almost a factor 5 more statistics than previously reported. The measured spectral distortion in the anti-neutrino spectrum favors neutrino oscillation as the explanation for neutrino disappearance and gives the best value of [Formula: see text] to date.
Measuring νμ Charged-Current Interactions in MiniBooNE
Authors:   for the BooNE Collaboration., Wascko Morgan O.
Published: August 2005

MiniBooNE seeks to confirm or refute the LSND [Formula: see text] oscillation signal with high statistical significance and different systematics. MiniBooNE has accumulated the world's largest ~1 GeV neutrino data set. MiniBooNE employs a cosmic muon calibration system to study the reconstruction of the energies and directions of muons in the detector. Progress of measurements of the νμ charged-current quasi-elastic and single pion production cross sections are presented.
NEUTRINO PHYSICS FROM NEW MEASUREMENTS
Authors: YÜKSEL H.
Published: August 2005

Emergence of neutrino physics is fueled by the recent growth in quality and quantity of experimental data, yet, there are still open questions. How much can the determination of mixing parameters be improved? Can we improve bounds on θ13 before experiments designed specifically for this parameter start? How well can we determine or limit sterile fraction of neutrino flux from sun and sterile mixing angle? We examine the impact of outcome from new measurements in the context of providing answers to these questions.
THE AMANDA NEUTRINO TELESCOPE
Authors:   for the AMANDA Collaboration., SILVESTRI ANDREA
Published: August 2005

We present recent results from the Antarctic Muon And Neutrino Detector Array (AMANDA), located at the South Pole in Antarctica. AMANDA-II, commissioned in 2000, is a multipurpose high energy neutrino telescope with a broad physics and astrophysics scope. We summarize the results from searches for a variety of sources of ultra-high energy neutrinos: TeV-PeV diffuse sources by measuring either muon tracks or cascades, neutrinos in excess of PeV by searching for muons traveling in the down-going direction and point sources.
OSCILLATORY SIGNATURE IN ATMOSPHERIC NEUTRINOS
Authors:   for THE SUPER-KAMIOKANDE COLLABORATION., KIEŁCZEWSKA DANUTA
Published: August 2005

Interactions of atmospheric neutrinos in Super-Kamiokande detector (SK-I) have been recently reanalysed. We report here results of standard oscillation analysis based on zenith angle distributions as well as the new analysis based on a subsample of higher precision data. The latter show a dip in the plot of the muon neutrino survival probability as a function of the ratio of the distance over neutrino energy. As a result the parameters of the transitions νμ ↔ ντ, are better constrained: 1.9 × 10-3 < Δm2 < 3.0 × 10-3 eV 2 and sin 22θ > 0.90 at 90% C.L.
Limits on the Neutrino Magnetic Moment Using Super-Kamiokande Solar Neutrino Data
Authors:   Super-Kamiokande Collaboration., Liu D. W.
Published: August 2005

Existence of non-zero neutrino magnetic moment would mean new physics beyond the standard model. A search for the neutrino magnetic moment has been conducted using the high statistic solar neutrino data from Super-Kamiokande-I. This is done by looking for the distortion to the observed energy spectrum of recoil electrons. A non-zero neutrino magnetic moment would cause an increase of event rates at lower energies. The search found no clear signal of neutrino magnetic moment. A limit on the neutrino magnetic moment has been obtained at 3.6 × 10-10μB at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The effects of neutrino oscillation have been included in the analysis. Including results from other neutrino experiments limiting the oscillation region, a limit of 1.1 × 10-10μB at 90% C.L. was obtained.
SO(10) GUT's, Neutrinos and LFV
Authors: Chen Mu-Chun , Mahanthappa K. T.
Published: August 2005

A model based on SO(10) × SU(2)F having symmetric mass textures with 5 zeros is constructed. The symmetric mass textures arising from the left-right symmetry breaking chain of SO (10) give rise to good predictions for the masses, mixing angles and CP violation measures in the quark and lepton sectors, all in agreement with the most up-to-date experimental data within 1 σ. Various lepton flavor violating decays in our model are also investigated. Unlike in models with lop-sided textures, our prediction for the decay rate of μ → e γ is much suppressed and yet it is large enough to be probed by the next generation of experiments. The observed baryonic asymmetry in the Universe can be accommodated utilizing soft leptogenesis.
HIGH ENERGY ASTROPHYSICS TESTS OF LORENTZ INVARIANCE VIOLATION
Authors: STECKER F. W.
Published: August 2005

Observations of the multi-TeV spectra of the Mkn 501 and other nearby BL Lac objects exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with IR photons having a flux level as determined by various astronomical observations. After correcting for such intergalactic absorption, these spectra can be explained within the framework of synchrotron self-Compton emission models. Stecker and Glashow have shown that the existence of this annihilation via electron-positron pair production puts strong constraints on Lorentz invariance violaition. Such constraints have important implications for some quantum gravity and large extra dimension models. A much smaller amount of Lorentz invariance violation has potential implications for understanding the spectra of ultrahigh energy cosmic rays.
Observations of Supernova Remnants with H.E.S.S.
Authors:   for the H.E.S.S. collaboration., MASTERSON CONOR
Published: August 2005

The High Energy Stereoscopic System (H.E.S.S.) consists of four telescopes each equipped with a 960 photomultiplier tube camera covering a field of view of 5°. The complete system has an angular resolution of a few arc minutes, an effective energy range from 100 GeV to 20 TeV with energy resolution of 15 to 20 percent and a flux sensitivity approaching 10-13 erg cm -2 s -1. These characteristics, together with its southern hemisphere location, make H.E.S.S. ideally suited for spectral and morphological studies of Galactic Plane sources such as the supernova remnants RX J1713-3946 and SN 1006. Here we present data taken on these sources in 2003, during the construction and commissioning phase of H.E.S.S.
STATUS OF THE ICECUBE NEUTRINO TELESCOPE
Authors:   For the IceCube Collaboration., DEYOUNG T.
Published: August 2005

IceCube is a kilometer-scale deep-ice neutrino telescope, to be constructed at the South Pole beginning in January 2005. The concept and design of IceCube, its science goals, present status, and expected performance will be discussed.
Gamma-ray Observation of Nearby Starburst Galaxy IC342
Authors:   For the VERITAS Collaboration., Nagai Tomoyuki , Vassiliev Vladimir
Published: August 2005

Regions with high star formation rates (SFR) in starburst galaxies (SBGs) are frequently accompanied by high density clouds of interstellar matter (ISM). This may create nearly perfect conditions for generating diffuse gamma-ray radiation as high energy cosmic rays accelerated in supernovae explosions of massive progenitor stars interact with the ambient protons. If the current paradigm that supernovae are the origin sites of high energy cosmic rays is valid, then the star forming regions rich in supernovae may become the laboratories to test and study this phenomenon. The gamma-ray luminosity of these extragalactic objects is suppressed by a large distance factor compared to supernovae in our own galaxy. However, flux estimates indicate that if star bursting regions have a proper combination of critical parameters (intersteller medium density, age, size, supernova rate, magnetic field strength) the cumulative enhancement of the gamma-ray luminosity resulting from multiple explosions of supernovae into dense ISM may generate an observable flux for nearby SBGs such as M82, IC342. A search for TeV gamma-ray emission from IC342 was conducted with the Whipple 10m gamma-ray telescope from September 2002 to March 2004.
The Search for Single Top Quark Production in the Muon plus Jets Channel at DØ
Authors:   For the DØ Collaboration., Christofek Leonard
Published: August 2005

We have performed a search for the electroweak production of single top quarks in [Formula: see text] collisions at the Fermilab Tevatron at a center of mass energy of [Formula: see text]. The search was performed in the muon plus jets decay channel requiring at least one b-tagged jet. The data were collected using the DØ detector between August 2002 and September 2003 corresponding to an integrated luminosity of 158 pb-1. The resulting 95% C.L. upper limits on the production cross sections are 27 pb in the s-channel, 41 pb in the t-channel, and 36 pb in the combined s + t channel using the secondary vertex tagger (SVT) algorithm. We also present results from the combined electron and muon channel search using the DØ detector.
New Results from Single-Top-Quark Searches with the CDF II Detector
Authors:   On behalf of the CDF Collaboration., CIOBANU CATALIN I.
Published: August 2005

In this paper we present new results from single-top-quark searches with the CDF II detector at the Fermilab Tevatron. In a data sample of 162 pb-1 of proton-antiproton collisions accumulated at CDF, we find no significant evidence for signal and set an upper limit of 17.8 pb on the total single-top production rate, at 95% confidence level. Individual upper limits of 10.1 pb and 13.6 pb are set on the the individual rates of t–channel, and s–channel single-top, respectively.
MEASUREMENT OF R = B(t→Wb)/B(t→Wq) AT DØ
Authors:   on behalf of the DØ Collaboration., STRANDBERG JONAS
Published: August 2005

A measurement of the ratio of branching fractions, R = B(t→Wb)/B(t→Wq), with q being any quark with I3 = -1/2 and Q = -1/3, is presented. This analysis considers samples of single- and double-tagged lepton+jets events obtained with the DØ detector, corresponding to integrated luminosities of 169 pb-1 and 158 pb-1, respectively in the e+jets and μ+jets channels. Two different lifetime taggers, CSIP and SVT, are used.
New Signatures For Top In Hadron Collider
Authors: Han Tao , Valencia German , Wang Yili
Published: August 2005

We study the signatures for new TeV resonances that couple to top or bottom quarks both at the Tevatron Run II and at the LHC. We find that it is possible to study these resonances when they are produced in association with a pair of heavy quarks or in association with a single top at the LHC. In particular, with an integrated luminosity of 300 fb-1 at the LHC, it is possible to probe resonance masses up to around 2 TeV.
LIQUID–GAS PHASE TRANSITION TO FIRST ORDER OF AN ARGON-LIKE FLUID MODELED BY MIE POTENTIAL
Authors: TIAN JIANXIANG , GUI YUANXING
Published: August 2005

In this paper, we analyze the liquid–gas phase transiton to first order of an Argon-like fluid modeled by Mie potential by the theory in Ref. 1. At the same time, we extend the theory to arbitrary D space dimensions.
FERROELECTRIC PROPERTIES AND INTERFACIAL CHARACTERISTICS OF Ca SUBSTITUTED STRONTIUM BISMUTH TANTALATE THIN FILMS
Authors: DAS RASMI R. , BHATTACHARYA P. , PÉREZ W. , KATIYAR RAM S.
Published: August 2005

In this study, we have investigated the structural, interfacial and ferroelectric properties of Sr 1-x Ca x Bi 2 Ta 2 O 9 thin films grown on Pt / TiO 2/ SiO 2/ Si substrates using pulsed-laser-deposition technique. The decrease in lattice parameters with increasing Ca content was attributed to the smaller ionic radius of Ca . Atomic force microscopy shows that the average grain size and surface roughness of the films increases with the incorporation of Ca . Films with x=0.2 exhibited a maximum remanent polarization of ~23.8 μ C/cm 2 with a coercive field of 175 kV/cm. The higher remanent polarization was attributed to the increased grain size and to the increase in the lattice mismatch between TaO 2 and SrO planes. The presence of metallic bismuth at the interface of the film and the substrates was confirmed using XPS depth profile analysis. The current transport property of the thin film capacitors suggests a bulk-limited dc-current conduction mechanism.
OPEN QUANTUM DYNAMICS: COMPLETE POSITIVITY AND ENTANGLEMENT
Authors: BENATTI FABIO , FLOREANINI ROBERTO
Published: August 2005

We review the standard treatment of open quantum systems in relation to quantum entanglement, analyzing, in particular, the behavior of bipartite systems immersed in the same environment. We first focus upon the notion of complete positivity, a physically motivated algebraic constraint on the quantum dynamics, in relation to quantum entanglement, i.e. the existence of statistical correlations which can not be accounted for by classical probability. We then study the entanglement power of heat baths versus their decohering properties, a topic of increasing importance in the framework of the fast developing fields of quantum information, communication and computation. The presentation is self contained and, through several examples, it offers a detailed survey of the physics and of the most relevant and used techniques relative to both quantum open system dynamics and quantum entanglement.
REFINED ALGEBRAIC QUANTIZATION WITH THE TRIANGULAR SUBGROUP OFSL(2, ℝ)
Authors: LOUKO JORMA , MOLGADO ALBERTO
Published: August 2005

We investigate refined algebraic quantization with group averaging in a constrained Hamiltonian system whose gauge group is the connected component of the lower triangular subgroup of SL (2, ℝ). The unreduced phase space is T*ℝp+qwith p≥1 and q≥1, and the system has a distinguished classical [Formula: see text] observable algebra. Group averaging with the geometric average of the right and left invariant measures, invariant under the group inverse, yields a Hilbert space that carries a maximally degenerate principal unitary series representation of O (p, q). The representation is nontrivial iff (p, q) ≠ (1, 1), which is also the condition for the classical reduced phase space to be a symplectic manifold up to a singular subset of measure zero. We present a detailed comparison to an algebraic quantization that imposes the constraints in the sense ĤaΨ = 0 and postulates self-adjointness of the [Formula: see text] observables. Under certain technical assumptions that parallel those of the group averaging theory, this algebraic quantization gives no quantum theory when (p, q) = (1, 2) or (2, 1), or when p≥2, q≥2 and p+q ≡1 ( mod 2).
GAUGE THEORIES AS A GEOMETRICAL ISSUE OF A KALUZA–KLEIN FRAMEWORK
Authors: CIANFRANI FRANCESCO , MARROCCO ANDREA , MONTANI GIOVANNI
Published: August 2005

We present a geometrical unification theory in a Kaluza–Klein approach that achieve the geometrization of a generic gauge theory bosonic component.

We show how it is possible to derive gauge charge conservation from the invariance of the model under extra-dimensional translations and to geometrize gauge connections for spinors, in order to make possible to introducing matter just through free spinorial fields. Then we present the applications to (i) a pentadimensional manifold V4 ⊗ S1 so reproducing the original Kaluza–Klein theory with some extensions related to the rule of the scalar field contained in the metric and to the introduction of matter through spinors with a phase dependance from the fifth coordinate, (ii) a seven-dimensional manifold V4 ⊗ S1 ⊗ S2, in which we geometrize the electroweak model by introducing two spinors for every leptonic family and quark generation and a scalar field with two components with opposite hypercharge responsible for spontaneous symmetry breaking.
THE X-RAY SPECTRAL ANALYSIS OF DWARF NOVA WZ Sge OBSERVED WITH ROSAT IN QUIESCENCE
Authors: GÜN GÜLNUR İKİS
Published: August 2005

X-ray spectral parameters were determined for WZ Sge observed with the ROSAT PSPC. The raw data were fitted with various spectral models and the best fit spectral models are found to be that of Raymond–Smith and Thermal Bremsstrahlung. The best fit temperature was estimated to be kT ~ 2.17 keV while the column density was found to be NH ~ 2.8 × 1020 cm -2. The estimated 0.1–2.4 keV flux was in the range of log F = -12 ergs cm -2 s -1.

WZ Sge stars show long outburst recurrence times and weak X-ray emissions during the quiescence states. It is possible to lengthen repetition cycles by decreasing the viscosity parameter (α); however there still remains the question why α is so small, specifically for these objects. The Coronal Siphon Model of Meyer and Meyer–Hofmeister1 can explain these phenomenons successfully. For this reason, the equations of this model were applied to the results of spectral analysis. Using this model, the mass accretion rate, mass evaporation rate in corona and the radius of the corona were calculated to be 1014.48 gr yr-1, 10-5.4 gr cm-2 s-1 and 109.7 cm, respectively. The obtained values suggest that the corona model can indeed operate in WZ Sge system.
Detrital zircon provenance constraints on the evolution of the Harts Range Metamorphic Complex (central Australia): links to the Centralian Superbasin
Authors: Buick Ian S. , Hand Martin , Williams Ian S. , Mawby Jo , Miller Jodie A. , Nicoll Robert S.
Published: August 2005

Until recently it has been widely accepted that protoliths to metasediments of the Harts Range Metamorphic Complex (central Australia) were deposited prior to
c
. 1.75 Ga and form part of the Palaeoproterozoic Arunta Inlier. However, new sensitive high-resolution ion microprobe U–Pb analyses of detrital zircon, together with recently published data, suggest that they were deposited coeval with
c
. 545–520 Ma sediments from the adjacent, little metamorphosed Neoproterozoic to Palaeozoic Centralian Superbasin. Protoliths of the Harts Range Metamorphic Complex were deposited in the Irindina sub-basin, an early- to mid-Cambrian rift located between the present-day Amadeus and Georgina Basin remnants of the Centralian Superbasin. Deposition occurred during a widespread and long-lived interval of extension in parts of central Australia associated with eruption of the voluminous Kalkarinji Continental Flood Basalts. The Harts Range Metamorphic Complex was metamorphosed to upper amphibolite- to granulite-facies conditions within
c
. 40 Ma of deposition of its sedimentary protoliths.
Interaction between collisional orogenesis and convergent-margin processes: evolution of the Cambrian proto-Pacific margin of East Gondwana
Authors: Squire Richard J. , Wilson Christopher J. L.
Published: August 2005

Difficulties in correlating the Cambrian magmatic, depositional, structural and metamorphic events along the proto-Pacific margin of East Gondwana have led to subdivision of the region into the Delamerian, Lachlan and Tyennan Orogens in Australia, the Ross Orogen in Antarctica and the Takaka Terrane in New Zealand. As a result, the Cambrian tectonic evolution of the region is poorly understood. We present here a revised lithostratigraphic section from the late Early to Mid-Cambrian rocks exposed near Stawell in western Victoria, which is used as the basis for correlating geological events in East Gondwana. These data show that the Cambrian tectonic evolution of East Gondwana's >4000 km long proto-Pacific margin involved predominantly compressional orogenesis separated by major short-lived extensional events at
c
. 516–514 and 504–500 Ma. The most significant extensional event, at
c
. 516–514 Ma, involved extensive slab rollback along the proto-Pacific margin in response to major changes in global plate motions and plate-boundary stresses following the termination of East–West Gondwana collision. Partial subduction of a ribbon of buoyant continental crust led to localized subduction-zone failure and obduction of the young hot forearc lithosphere in Tasmania at
c
. 510 Ma. Collision of the continental ribbon also significantly modified the architecture of the proto-Pacific margin and ultimately controlled the extent of the second major extensional event associated with slab rollback at
c
. 504–500 Ma. Tectonic evolution of the proto-Pacific margin of East Gondwana thus involved the complex interaction between convergent-margin processes and collisional orogenesis.
Neoarchaean (

c

. 2.58 Ga) halite casts: implications for palaeoceanic chemistry
Authors: Eriksson K. A. , Simpson E. L. , Master S. , Henry G.
Published: August 2005

Possibly the most extensive and best-preserved Archaean halite casts yet discovered occur in the
c
. 2.58 Ga upper Black Reef and basal Oaktree formations, Transvaal Supergroup, in Mpumalanga Province, South Africa. Halite casts are isolated on bedding planes, range in size from
c
. 1 mm to 20 mm, and have cubic, dumbbell and triangular shapes, as well as hopper-like pyramidal hollows on cube faces. Some of the casts display distinct hopper shapes characteristic of halite crystals. The halite cast-bearing pavements are developed within silicified mudstone interbedded with siltstone or stromatolitic dolomite. Associated sedimentary structures pointing to subaerial exposure include adhesion ripples and warts, desiccation and prism cracks, rill marks and tepee structures. Halite cast-bearing beds are interpreted as supratidal flat or sabkha deposits. The presence of isolated casts and hopper-shaped crystals suggests that halite resulted from displacive growth within the sediment from supersaturated residual brines after mudstone deposition. Absence of any indication of the former presence of gypsum or anhydrite supports previous contentions that the Neoarchaean ocean was deficient in sulphate or contained a high bicarbonate to calcium ratio such that with progressive evaporation, most calcium was consumed before the gypsum stability field was reached. The association of halite and carbonate in the upper Black Reef and basal Oaktree formations constrains the palaeolatitude of the Transvaal Basin at 2.58 Ga to subequatorial (10–30°).
Evolutionary Ecology of Plant Adaptation to Serpentine Soils
Authors: Brady Kristy U. , Kruckeberg Arthur R. , Bradshaw Jr. H.D.
Published: August 2005

▪ Abstract  Plant adaptation to serpentine soil has been a topic of study for many decades, yet investigation of the genetic component of this adaptation has only recently begun. We review the defining properties of serpentine soil and the pioneering work leading to three established physiological and evolutionary mechanisms hypothesized to be responsible for serpentine tolerance: tolerance of a low calcium-to-magnesium ratio, avoidance of Mg toxicity, or a high Mg requirement. In addition, we review recent work in serpentine ecology documenting the high proportion of endemic species present, the adaptive morphologies of serpentine-tolerant plants, and the distinctive structure of serpentine communities. Studies of the physiological mechanisms proposed to confer serpentine tolerance have shown that uptake of particular ions and heavy metals varies between serpentine-tolerant and -intolerant species. Recent studies examining the genetic basis of serpentine adaptation have shown serpentine-adaptive quantitative trait loci (QTL) to have large phenotypic effects, drought tolerance to be as important as metal tolerance, and serpentine adaptation to have evolved independently multiple times within species. Investigations of plant races and species adapted to contrasting soil types have shown disparate flowering times, divergent floral morphologies, and pollen incompatibility to contribute to reproductive isolation. Finally, we propose that future studies involving serpentine systems should merge the fields of ecology, evolution, physiology, and genetics.
The Influence of Plant Secondary Metabolites on the Nutritional Ecology of Herbivorous Terrestrial Vertebrates
Authors: Dearing M. Denise , Foley William J. , McLean Stuart
Published: August 2005

▪ Abstract  Plant secondary metabolites (PSMs) significantly impact the nutritional ecology of terrestrial vertebrate herbivores. Herbivores have a wide range of mechanisms (herbivore offenses) to mitigate the negative effects of PSMs. We discuss several behavioral and physiological offenses used by terrestrial vertebrates. Several newly recognized herbivore offenses such as regulated absorption and regulation of toxin intake are presented. We give a detailed description of the biotransformation system with respect to PSMs. We also summarize recent findings of plant–animal interactions for lizards, birds, and mammals. Finally, we discuss some new tools that can be applied to long-standing questions of plant–vertebrate interactions.
Biodiversity-Ecosystem Function Research: Is It Relevant to Conservation?
Authors: Srivastava Diane S. , Vellend Mark
Published: August 2005

▪ Abstract  It has often been argued that conserving biodiversity is necessary for maintaining ecosystem functioning. We critically evaluate the current evidence for this argument. Although there is substantial evidence that diversity is able to affect function, particularly for plant communities, it is unclear if these patterns will hold for realistic scenarios of extinctions, multitrophic communities, or larger spatial scales. Experiments are conducted at small spatial scales, the very scales at which diversity tends to increase owing to exotics. Stressors may affect function by many pathways, and diversity-mediated effects on function may be a minor pathway, except in the case of multiple-stressor insurance effects. In general, the conservation case is stronger for stability measures of function than stock and flux measures, in part because it is easier to attribute value unambiguously to stability and in part because stock and flux measures of functions are anticipated to be more affected by multitrophic dynamics. Nor is biodiversity-ecosystem function theory likely to help conservation managers in practical decisions, except in the particular case of restoration. We give recommendations for increasing the relevance of this area of research for conservation.
Individual-Based Modeling of Ecological and Evolutionary Processes
Authors: DeAngelis Donald L. , Mooij Wolf M.
Published: August 2005

▪ Abstract  Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential-equation and difference-equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis for IBMs by describing five major types of individual variation in IBMs: spatial, ontogenetic, phenotypic, cognitive, and genetic. IBMs are now used in almost all subfields of ecology and evolutionary biology. We map those subfields and look more closely at selected key papers on fish recruitment, forest dynamics, sympatric speciation, metapopulation dynamics, maintenance of diversity, and species conservation. Theorists are currently divided on whether IBMs represent only a practical tool for extending classical theory to more complex situations, or whether individual-based theory represents a radically new research program. We feel that the tension between these two poles of thinking can be a source of creativity in ecology and evolutionary theory.
Personality and the Prediction of Consequential Outcomes
Authors: Ozer Daniel J. , Benet-Martínez Verónica
Published: August 2005

Personality has consequences. Measures of personality have contemporaneous and predictive relations to a variety of important outcomes. Using the Big Five factors as heuristics for organizing the research literature, numerous consequential relations are identified. Personality dispositions are associated with happiness, physical and psychological health, spirituality, and identity at an individual level; associated with the quality of relationships with peers, family, and romantic others at an interpersonal level; and associated with occupational choice, satisfaction, and performance, as well as community involvement, criminal activity, and political ideology at a social institutional level.
Na-glucose and Na-neutral amino acid cotransport are uniquely regulated by constitutive nitric oxide in rabbit small intestinal villus cells
Authors: Coon Steven , Kim James , Shao Guohong , Sundaram Uma
Published: August 2005

Na-nutrient cotransport processes are not only important for the assimilation of essential nutrients but also for the absorption of Na in the mammalian small intestine. The effect of constitutive nitric oxide (cNO) on Na-glucose (SGLT-1) and Na-amino acid cotransport (NAcT) in the mammalian small intestine is unknown. Inhibition of cNO synthase with NG-nitro-l-arginine methyl ester (l-NAME) resulted in the inhibition of Na-stimulated 3H- O-methyl-d-glucose uptake in villus cells. However, Na-stimulated alanine uptake was not affected in these cells. The l-NAME-induced reduction in SGLT-1 in villus cells was not secondary to an alteration in basolateral membrane Na-K-ATPase activity, which provides the favorable Na gradient for this cotransport process. In fact, SGLT-1 was inhibited in villus cell brush-border membrane (BBM) vesicles prepared from animals treated with l-NAME. Kinetic studies demonstrated that the mechanism of inhibition of SGLT-1 was secondary to a decrease in the affinity for glucose without a change in the maximal rate of uptake of glucose. Northern blot studies demonstrated no change in the mRNA levels of SGLT-1. Western blot studies demonstrated no significant change in the immunoreactive protein levels of SGLT-1 in ileal villus cell BBM from l-NAME-treated rabbits. These studies indicate that inhibition of cNO production inhibits SGLT-1 but not NAcT in the rabbit small intestine. Therefore, whereas cNO promotes Na-glucose cotransport, it does not affect NAcT in the mammalian small intestine.
Examination of stimulation mechanism and strength-interval curve in cardiac tissue
Authors: Sidorov Veniamin Y. , Woods Marcella C. , Baudenbacher Petra , Baudenbacher Franz
Published: August 2005

Understanding the basic mechanisms of excitability through the cardiac cycle is critical to both the development of new implantable cardiac stimulators and improvement of the pacing protocol. Although numerous works have examined excitability in different phases of the cardiac cycle, no systematic experimental research has been conducted to elucidate the correlation among the virtual electrode polarization pattern, stimulation mechanism, and excitability under unipolar cathodal and anodal stimulation. We used a high-resolution imaging system to study the spatial and temporal stimulation patterns in 20 Langendorff-perfused rabbit hearts. The potential-sensitive dye di-4-ANEPPS was utilized to record the electrical activity using epifluorescence. We delivered S1-S2 unipolar point stimuli with durations of 2–20 ms. The anodal S-I curves displayed a more complex shape in comparison with the cathodal curves. The descent from refractoriness for anodal stimulation was extremely steep, and a local minimum was clearly observed. The subsequent ascending limb had either a dome-shaped maximum or was flattened, appearing as a plateau. The cathodal S-I curves were smoother, closer to a hyperbolic shape. The transition of the stimulation mechanism from break to make always coincided with the final descending phase of both anodal and cathodal S-I curves. The transition is attributed to the bidomain properties of cardiac tissue. The effective refractory period was longer when negative stimuli were delivered than for positive stimulation. Our spatial and temporal analyses of the stimulation patterns near refractoriness show always an excitation mechanism mediated by damped wave propagation after S2 termination.
Increased heme catabolism in critically ill patients: correlation among exhaled carbon monoxide, arterial carboxyhemoglobin, and serum bilirubin IXα concentrations
Authors: Morimatsu Hiroshi , Takahashi Toru , Maeshima Kyoichiro , Inoue Kazuyoshi , Kawakami Tomoko , Shimizu Hiroko , Takeuchi Mamoru , Yokoyama Masataka , Katayama Hiroshi , Morita Kiyoshi
Published: August 2005

It has been reported that exhaled carbon monoxide (CO) concentrations and arterial carboxyhemoglobin (CO-Hb) concentration in blood may be increased in critically ill patients. However, there was no study that examined correlation among amount of CO in exhaled air, CO-Hb concentrations in erythrocytes, and bilirubin IXα (BR) in serum, i.e., the three major indexes of heme catabolism, within the same subject. Here, we examined CO concentrations in exhaled air, CO-Hb concentrations in arterial blood, and BR levels in serum in 29 critically ill patients. Measurements of exhaled CO, arterial CO-Hb, and serum total BR have been done in the intensive care unit. As control, exhaled CO concentration was also measured in eight healthy volunteers. A median exhaled CO concentration was significantly higher in critically ill patients compared with control. There was significant correlation between CO and CO-Hb and CO and total BR level. We also found CO concentrations correlated with indirect BR but not direct BR. Multivariate linear regression analysis for amount of exhaled CO concentrations also showed significant correlation with CO-Hb and total BR, despite the fact that respiratory variables of study subjects were markedly heterogeneous. We found no correlation among exhaled CO, patients’ severity, and degree of inflammation, but we found a strong trend of a higher exhaled CO concentration in survivors than in nonsurvivors. These findings suggest there is an increased heme breakdown in critically ill patients and that exhaled CO concentration, arterial CO-Hb, and serum total BR concentrations may be useful markers in critically ill conditions.
Enhanced skeletal muscle arteriolar reactivity to ANG II after recovery from ischemic acute renal failure
Authors: Basile David P. , Donohoe Deborah L. , Phillips Shane A. , Frisbee Jefferson C.
Published: August 2005

In addition to the long-term renal complications, previous studies suggested that after acute renal failure (ARF), rats manifest an increased pressor response to an overnight infusion of ANG II. The present study tested whether recovery from ARF results in alterations in sensitivity to the peripheral vasculature. ARF was induced in Sprague-Dawley rats by 45 min of bilateral renal ischemia and reperfusion. Animals were allowed to recover renal structure and function for 5–8 wk, after which the acute pressor responses to ANG II were evaluated either in vivo in in situ skeletal muscle arterioles or in isolated gracilis muscle arteries in vitro. Baseline arterial pressure was not different in ARF rats vs. sham-operated controls, although ARF rats exhibited an enhanced pressor response to bolus ANG II infusion compared with control rats. Steady-state plasma ANG II concentration and plasma renin activity were similar between ARF and control rats. Constrictor reactivity of in situ cremasteric arterioles from ARF rats was enhanced in response to increasing concentrations of ANG II; however, no difference was observed in arteriolar responses to elevated Po2, norepinephrine, acetylcholine, or sodium nitroprusside. Isolated gracilis muscle arteries from ARF rats also showed increased vasoconstriction in response to ANG II but not norepinephrine. In conclusion, recovery from ischemic ARF is not associated with hypertension but is associated with increased arteriolar constrictor reactivity to ANG II. Although the mechanisms of this altered responsiveness are unclear, such changes may relate, in part, to cardiovascular complications in patients with ARF and/or after renal transplant.