bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary protein intake and renal function
Authors: Martin William F , Armstrong Lawrence E , Rodriguez Nancy R
Published: September 2005

Recent trends in weight loss diets have led to a substantial increase in protein intake by individuals. As a result, the safety of habitually consuming dietary protein in excess of recommended intakes has been questioned. In particular, there is concern that high protein intake may promote renal damage by chronically increasing glomerular pressure and hyperfiltration. There is, however, a serious question as to whether there is significant evidence to support this relationship in healthy individuals. In fact, some studies suggest that hyperfiltration, the purported mechanism for renal damage, is a normal adaptative mechanism that occurs in response to several physiological conditions. This paper reviews the available evidence that increased dietary protein intake is a health concern in terms of the potential to initiate or promote renal disease. While protein restriction may be appropriate for treatment of existing kidney disease, we find no significant evidence for a detrimental effect of high protein intakes on kidney function in healthy persons after centuries of a high protein Western diet.
Integration of the subarachnoid space and lymphatics: Is it time to embrace a new concept of cerebrospinal fluid absorption?
Authors: Koh Lena , Zakharov Andrei , Johnston Miles
Published: September 2005

In most tissues and organs, the lymphatic circulation is responsible for the removal of interstitial protein and fluid but the parenchyma of the brain and spinal cord is devoid of lymphatic vessels. On the other hand, the literature is filled with qualitative and quantitative evidence supporting a lymphatic function in cerebrospinal fluid (CSF) absorption. The experimental data seems to warrant a re-examination of CSF dynamics and consideration of a new conceptual foundation on which to base our understanding of disorders of the CSF system. The objective of this paper is to review the key studies pertaining to the role of the lymphatic system in CSF absorption.
Induction of a B-cell-dependent chronic arthritis with glucose-6-phosphate isomerase
Authors: Bockermann Robert , Schubert David , Kamradt Thomas , Holmdahl Rikard
Published: September 2005

Antibodies specific for glucose-6-phosphate isomerase (G6PI) from T-cell receptor transgenic K/BxN mice are known to induce arthritis in mice, and immunization of DBA/1 mice with G6PI led to acute arthritis without permanent deformation of their joints. Because rheumatoid arthritis is a chronic disease, we set out to identify the capacity of G6PI to induce chronic arthritis in mice. Immunization with recombinant human G6PI induced a chronically active arthritis in mice with a C3H genomic background, whereas the DBA/1 background allowed only acute arthritis and the C57BL/10 background permitted no or very mild arthritis. The disease was associated with the major histocompatibility region sharing an allelic association similar to that of collagen-induced arthritis (i.e. q > p > r). All strains developed a strong antibody response to G6PI that correlated only in the C3H.NB strain with arthritis severity. Similarly, a weak response to type II collagen in a few mice was observed, which was associated with arthritis in C3H.NB mice. Mice on the C3H background also developed ankylosing spondylitis in the vertebrae of the tail. Both C3H.Q and B10.Q mice deficient for B cells were resistant to arthritis. We conclude that G6PI has the ability to induce a chronic arthritis, which is MHC associated and B-cell dependent. Thus, there are striking similarities between this and the collagen-induced arthritis model.
Clioquinol and pyrrolidine dithiocarbamate complex with copper to form proteasome inhibitors and apoptosis inducers in human breast cancer cells
Authors: Daniel Kenyon G , Chen Di , Orlu Shirley , Cui Qiuzhi Cindy , Miller Fred R , Dou Q Ping
Published: September 2005

Introduction

A physiological feature of many tumor tissues and cells is the tendency to accumulate high concentrations of copper. While the precise role of copper in tumors is cryptic, copper, but not other trace metals, is required for angiogenesis. We have recently reported that organic copper-containing compounds, including 8-hydroxyquinoline-copper(II) and 5,7-dichloro-8-hydroxyquinoline-copper(II), comprise a novel class of proteasome inhibitors and tumor cell apoptosis inducers. In the current study, we investigate whether clioquinol (CQ), an analog of 8-hydroxyquinoline and an Alzheimer's disease drug, and pyrrolidine dithiocarbamate (PDTC), a known copper-binding compound and antioxidant, can interact with copper to form cancer-specific proteasome inhibitors and apoptosis inducers in human breast cancer cells. Tetrathiomolybdate (TM), a strong copper chelator currently being tested in clinical trials, is used as a comparison.

Methods

Breast cell lines, normal, immortalized MCF-10A, premalignant MCF10AT1K.cl2, and malignant MCF10DCIS.com and MDA-MB-231, were treated with CQ or PDTC with or without prior interaction with copper, followed by measurement of proteasome inhibition and cell death. Inhibition of the proteasome was determined by levels of the proteasomal chymotrypsin-like activity and ubiquitinated proteins in protein extracts of the treated cells. Apoptotic cell death was measured by morphological changes, Hoechst staining, and poly(ADP-ribose) polymerase cleavage.

Results

When in complex with copper, both CQ and PDTC, but not TM, can inhibit the proteasome chymotrypsin-like activity, block proliferation, and induce apoptotic cell death preferentially in breast cancer cells, less in premalignant breast cells, but are non-toxic to normal/non-transformed breast cells at the concentrations tested. In contrast, CQ, PDTC, TM or copper alone had no effects on any of the cells. Breast premalignant or cancer cells that contain copper at concentrations similar to those found in patients, when treated with just CQ or PDTC alone, but not TM, undergo proteasome inhibition and apoptosis.

Conclusion

The feature of breast cancer cells and tissues to accumulate copper can be used as a targeting method for anticancer therapy through treatment with novel compounds such as CQ and PDTC that become active proteasome inhibitors and breast cancer cell killers in the presence of copper.
Phase I Study of Gefitinib Plus Celecoxib in Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck
Authors: Wirth Lori J. , Haddad Robert I. , Lindeman Neal I. , Zhao Xiaojun , Lee Jeffrey C. , Joshi Victoria A. , Norris Charles M. , Posner Marshall R.
Published: September 2005

Purpose

Effective and tolerable palliative treatments are needed for patients with incurable squamous cell carcinoma of the head and neck (SCCHN). Single-agent targeted therapies have limited activity in this setting. The feasibility of adding celecoxib to gefitinib for the treatment of incurable SCCHN is unknown.

Patients and Methods

Nineteen patients with unresectable recurrent locoregional and/or distant metastatic SCCHN with progressive disease after at least one prior chemotherapy or chemoradiotherapy regimen were enrolled onto this single-institution phase I study. Three dose levels were explored: (1) celecoxib 200 mg twice daily plus gefitinib 250 mg daily; (2) celecoxib 400 mg twice daily plus gefitinib 250 mg daily; and (3) celecoxib 400 mg twice daily plus gefitinib 500 mg daily.

Results

No dose-limiting toxicities were encountered at any dose level. The most common toxicities were acneiform rash, diarrhea, hand reaction, dyspepsia, and anemia. Four of 18 patients assessable for response (22%; 95% CI, 2% to 42%) achieved a confirmed partial response.

Conclusion

The combination of gefitinib 500 mg daily plus celecoxib 400 mg twice daily is well-tolerated. The encouraging responses seen in this early study suggest further evaluation of epidermal growth factor receptor and cyclooxygenase-2 inhibitors in SCCHN is warranted.
ABVD Versus Modified Stanford V Versus MOPPEBVCAD With Optional and Limited Radiotherapy in Intermediate- and Advanced-Stage Hodgkin's Lymphoma: Final Results of a Multicenter Randomized Trial by the Intergruppo Italiano Linfomi
Authors: Gobbi Paolo G. , Levis Alessandro , Chisesi Teodoro , Broglia Chiara , Vitolo Umberto , Stelitano Caterina , Pavone Vincenzo , Cavanna Luigi , Santini Gino , Merli Francesco , Liberati Marina , Baldini Luca , Deliliers Giorgio Lambertenghi , Angelucci Emanuele , Bordonaro Roberto , Federico Massimo
Published: September 2005

Purpose

In this multicenter, prospective, randomized clinical trial on advanced Hodgkin's lymphoma (HL), the efficacy and toxicity of two chemotherapy regimens, doxorubicin, vinblastine, mechlorethamine, vincristine, bleomycin, etoposide, and prednisone (Stanford V) and mechlorethamine, vincristine, procarbazine, prednisone, epidoxirubicin, bleomycin, vinblastine, lomustine, doxorubicin, and vindesine (MOPPEBVCAD), were compared with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) as standard therapy to select which regimen would best support a reduced radiotherapy program, which was limited to ≤ two sites of either previous bulky or partially remitting disease (a modification of the original Stanford program).

Patients and Methods

Three hundred fifty-five patients with stage IIB, III, or IV HL were randomly assigned. Three hundred thirty-four patients were assessable for the study and received six cycles of ABVD (n = 122), three cycles of Stanford V (n = 107), or six cycles of MOPPEBVCAD (n = 106); radiotherapy was administered to 76, 71, and 50 patients in these three arms, respectively.

Results

The complete response rates for ABVD, Stanford V, and MOPPEBVCAD were 89%, 76% and 94%, respectively; 5-year failure-free survival (FFS) and progression-free survival rates were 78%, 54%, 81% and 85%, 73%, and 94%, respectively (P < .01 for comparison of Stanford V with the other two regimens). Corresponding 5-year overall survival rates were 90%, 82%, and 89% for ABVD, Stanford V, and MOPPEBVCAD, respectively. Stanford V was more myelotoxic than ABVD but less myelotoxic than MOPPEBVCAD, which had larger reductions in the prescribed drug doses.

Conclusion

When associated with conditioned and limited (not adjuvant) radiotherapy, ABVD and MOPPEBVCAD were superior to Stanford V chemotherapy in terms of response rate and FFS and progression-free survival. Patients were irradiated less often after MOPPEBVCAD, but this regimen was more toxic. ABVD is still the best choice when it is combined with optional, limited irradiation.
Phase I and Pharmacokinetic Study of Aplidine, a New Marine Cyclodepsipeptide in Patients With Advanced Malignancies
Authors: Faivre Sandrine , Chièze Stéphanie , Delbaldo Catherine , Ady-vago Nora , Guzman Cecilia , Lopez-Lazaro Luis , Lozahic Stéphanie , Jimeno José , Pico Fernando , Armand Jean Pierre , Martin José Antonio Lopez , Raymond Eric
Published: September 2005

Purpose

To establish the safety, pharmacokinetic parameters, maximum-tolerated dose, and recommended dose of aplidine, a novel marine cyclodepsipeptide, in patients with advanced cancer.

Patients and Methods

Using a modified Fibonacci method, we performed a phase I and pharmacokinetic study of aplidine administered as a 24-hour intravenous infusion every 2 weeks.

Results

Sixty-seven patients received aplidine at a dose ranging from 0.2 to 8 mg/m2. Dose-limiting myotoxicity corresponding to grade 2 to 3 creatine phosphokinase elevation and grade 1 to 2 myalgia and muscle weakness occurred in two of six patients at 6 mg/m2. No cardiac toxicity was observed. Electron microscopy analysis showed the disappearance of thick filaments of myosin. Grade 3 muscle toxicity occurred in three of 14 patients at the recommended dose of 5 mg/m2 and seemed to be more readily reversible with oral carnitine (1 g/10 kg). Therefore, dose escalation was resumed using carnitine prophylactically, allowing an increase in the recommended dose to 7 mg/m2. Other toxicities were nausea and vomiting, diarrhea, asthenia, and transaminase elevation with mild hematologic toxicity. Aplidine displayed a long half-life (21 to 44 hours), low clearance (45 to 49 L/h), and a high volume of distribution (1,036 to 1,124 L) with high interpatient variability in plasma, whereas in whole blood, clearance ranged from 3.0 to 6.2 L/h. Minor responses and prolonged tumor stabilizations were observed in patients with medullary thyroid carcinoma.

Conclusion

Muscle toxicity was dose limiting in this study. Recommended doses of aplidine were 5 and 7 mg/m2 without and with carnitine, respectively. The role of carnitine will be further explored in phase II studies.
End-of-Life Care Preferences of Pediatric Patients With Cancer
Authors: Hinds Pamela S. , Drew Donna , Oakes Linda L. , Fouladi Maryam , Spunt Sheri L. , Church Christopher , Furman Wayne L.
Published: September 2005

Purpose

The viewpoint of the terminally ill child at the time of an end-of-life decision has not been formally investigated. We identified the preferences of children and adolescents with advanced cancer about their end-of-life care and the factors that influenced their decisions.

Patients and Methods

Pediatric patients 10 or more years of age were interviewed within 7 days of participating in one of the following three end-of-life decisions: enrollment onto a phase I trial (n = 7), adoption of a do not resuscitate order (n = 5), or initiation of terminal care (n = 8). The patient, a parent, and the primary pediatric oncologist were interviewed separately by using open-ended interview questions.

Results

Twenty patients, aged 10 to 20 years (mean, 17 years and 4 months), with a refractory solid tumor (n = 12), brain tumor (n = 4), or leukemia (n = 4) participated. Eighteen patients (90%) accurately recalled all of their treatment options and identified their own death as a consequence of their decision. The factors that were most frequently identified included the following: for patients, caring about others (n = 19 patients); for parents, the child's preferences (n = 18 parents); and for physicians, the patient's prognosis and comorbid conditions (n = 14 physicians).

Conclusion

These children and adolescents with advanced cancer realized that they were involved in an end-of-life decision, understood the consequences of their decision, and were capable of participating in a complex decision process involving risks to themselves and others. The decision factors most frequently reported by patients were relationship based; this finding is contrary to existing developmental theories.
Intense Shock Waves and Extreme States of Plasma
Authors: Fortov V E
Published: September 2005

Physical properties of hot dense matter under strong shock compression are considered. The experimental results on shock compression of liquidized deuterium and noble gases are observed. A model of strongly compressed plasma on the basis of a chemical picture of plasma at conditions of experiments with intense shock waves is presented.
A Method for Filtering and Controlling Soliton States of Bose-Einstein Condensates
Authors: Fedele R , Shukla P K , De Nicola S , Man'ko M A , Man'ko V I , Cataliotti F S
Published: September 2005

A method for filtering and controlling soliton states of the Bose-Einstein condensate is presented. The analysis is carried out by considering the 3D Gross-Pitaevskii (GP) equation with appropriate confining potential wells. Suitable matching conditions, which are relevant for filtering and mantaining localized states in experiments, are established and exact controlled analytical solutions of the 3D GP equation are found and compared with the approximate ones obtained with variational approches.
A Cyclotron Maser Instability with Application to Space and Laboratory Plasmas
Authors: Cairns R A , Speirs D C , Ronald K , Vorgul I , Kellett B J , Phelps A D R , Bingham R
Published: September 2005

When a beam of electrons moves into a converging magnetic field, the velocity distribution function takes on a horseshoe shape as a result of conservation of magnetic moment. A few years ago it was pointed out that such a distribution is unstable to a cyclotron maser type of instability and it was suggested that this instability might be the source of auroral kilometric radiation (Bingham, R. and Cairns, R. A., Phys. Plasmas 7, 3089 (2000).) and also of emission from certain types of star (Bingham, R., Cairns, R. A. and Kellett, B. J., Astron. Astrophys. 370, 1000 (2001).).

Here we present more recent work on this topic. Since the dispersion relation which describes the instability only depends on the factor by which the magnetic field increases and on ratios of the wave plasma and cyclotron frequencies, it is possible to scale the effect to laboratory dimensions. An experiment to do this is being carried out at the University of Strathclyde and is expected to be operational during the summer of 2004. The objective is to investigate whether this mechanism might produce a useful radiation source, as well as to give a laboratory simulation of auroral kilometric radiation. The design of this experiment and its current status are described.

On the theoretical side we discuss computer simulations showing the instability and its quasilinear saturation in the geometry of the experiment. We also describe a much more detailed theory of the linear instability than we have presented in previous work. Growth rates have been calculated in cylindrical geometry with various electron beam configurations and different cylindrical mode structures. These, and the simulations, support the conclusion of our earlier work that the instability has a high growth rate.
The Extended Third-Order Nonlinear Schrödinger Equation and Galileo's Transformation
Authors: Karpman V I
Published: September 2005

The extended third-order nonlinear Schrödinger equation and its solutions is studied on the basis of Galileo's transformation and generalized Galileo's invariance.
Scaling, Intermittency and Decay of MHD Turbulence
Authors: Lazarian A , Cho Jungyeon
Published: September 2005

We discuss a few recent developments that are important for understanding of MHD turbulence. First, MHD turbulence is not so messy as it is usually believed. In fact, the notion of strong nonlinear coupling of compressible and incompressible motions along MHD cascade is not tenable. Alfvén, slow and fast modes of MHD turbulence follow their own cascades and exhibit degrees of anisotropy consistent with theoretical expectations. Second, the fast decay of turbulence is not related to the compressibility of fluid. Rates of decay of compressible and incompressible motions are very similar. Third, viscosity by neutrals does not suppress MHD turbulence in a partially ionized gas. Instead, MHD turbulence develops magnetic cascade at scales below the scale at which neutrals damp ordinary hydrodynamic motions. Forth, density statistics does not exhibit the universality that the velocity and magnetic field do. For instance, at small Mach numbers the density is anisotropic, but it gets isotropic at high Mach numbers. Fifth, the intermittency of magnetic field and velocity are different. Both depend on whether the measurements are done in a local system of reference oriented along the local magnetic field or in the global system of reference related to the mean magnetic field.
Mach Cones in Space and Laboratory Dusty Magnetoplasmas
Authors: Mamun A A , Shukla P K
Published: September 2005

We present a rigorous theoretical investigation on the possibility for the formation of Mach cones in both space and laboratory dusty magnetoplasmas. We find the parametric regimes for which different types of Mach cones, such as dust-acoustic Mach cones, dust magneto-acoustic Mach cones, oscillonic Mach cones, etc. are formed in space and laboratory dusty magnetoplasmas. We also identify the basic features of such different classes of Mach cones (viz. dust-acoustic, dust magneto-acoustic, oscillonic Mach cones, etc.), and clearly explain how they are relevant to space and laboratory dusty magnetoplasmas.
Ion Acoustic Shock Waves in a Dusty Plasma
Authors: Khan Manoranjan , Ghosh Samiran , Sarkar Susmita , Gupta M R
Published: September 2005

A dispersive shock wave is generated in a plasma when wave breaking due to the nonlinearity is balanced by the combined action of dispersion and dissipation. In the absence of dissipation, the dispersive effect leads to the generation of solitons described by a KdV equation. On the other hand, when dissipation dominates, the shock front exhibits a monotonic transition of plasma density, while the shock transition is of oscillatory nature when the dissipation is weak. In a dusty plasma, when viscosity and Landau damping effects are not important, the nonadiabaticity of the dust charge variation provides shocks for which both monotonic and oscillatory structures are possible, and such shocks can be described by a K-dV Burger equation.

In this paper the evolution of the Dust Ion Acoustic (DIA) shock waves is discussed. In addition, analytical studies of the propagation of DIA waves governed by K-dV Burger equation are presented.
Filamentation Instability of Thin Current Sheets in Low-β Plasmas
Authors: Jovanović D , Pegoraro F , Shukla P K
Published: September 2005

An analytic theory is presented for the collisionless filamentation instability of thin current sheets in the frequency domain of lower-hybrid waves in low-β plasmas. In a configuration with a strong guide field, the plasma dynamics is studied in a fluid description, accounting for the effects of electron polarization and finite Larmor radii, as well as of the motion of unmagnetized ions in the presence of perpendicular electric fields. In the linear phase, two types of unstable perturbations of a thin current sheet with steep edges are identified that correspond to its filamentation or tearing and bending. Using a surface-wave formalism for the modes whose wavelength is larger than the current sheet thickness, the corresponding growth rates are calculated as the contributions of singularities in the dispersion function of surface waves. These are governed by the electron inertia and by linear coupling with local plasma modes propagating in the perpendicular direction that are subjected to the Buneman instability. This new linear instability provides a suitable channel for the dissipation of current sheets that evolve during the collisionless magnetic reconnection in shear- and kinetic-Alfvén regimes, and for the creation of anomaluos resistivity.
Motion of a Charged Parand Plasma Equilibrium in a Dipole Magnetic Field – Can a Magnetic Field Trap a Charged Particle? Can a Magnetic Field Having Bad Curvature Trap a Plasma Stably?
Authors: Hasegawa Akira
Published: September 2005

Since there is no magnetic monopole, the dipole magnetic field is the most elementary form of magnetic field. By studying carefully the motion of a single charged particle and the plasma equilibrium that results, one can obtain insight in the basic behavior of particle motion and equilibrium in a magnetic field. What will be the exact motion of a charged particle? What will be the guiding center motion? Are the equations of motion integrable? What happens if not? Is the plasma equilibrium in a magnetic field having bad curvature everywhere stable? This paper will cover these elementary questions using Hamiltonian dynamics.
Generation of Electric Solitary Structures Electron Holes by Nonlinear Low-FrequencyWaves
Authors: Lakhina G S , Tsurutani B T , Pickett J S
Published: September 2005

High resolution electric and magnetic wave data, obtained by Polar during its passage through the polar cap/cusp boundary layer, show large amplitude low-frequency electromagnetic waves and electric bipolar pulses electron holes. It is proposed that nonlinear low-frequency waves, consisting of Alfvén and/or proton cyclotron waves, can drive high-frequency electrostatic modes which saturate by trapping electrons, thereby leading to the generation of electron holes. The free energy sources for these electrostatic instabilities are the parallel currents, which are produced due to relative motion of electrons and ions in the presence of large amplitude low-frequency waves.
X-Ray Emission from Comets and Nonmagnetic Planets. Theory and Comparison with CHANDRA Observations
Authors: Shapiro V D , Bingham R , Kellett B J , Quest K , Mendis D A , Bryans P , Torney M , Summers H P
Published: September 2005

Mass loading of the solar wind by newly created cometary photoions as well as counterstreaming fluxes of protons in the mantle regions at the ionospheric boundaries of nonmagnetic planets Mars, Venus result in the modified two stream instability MTSI and excitation of the intense lower hybrid wave turbulence. Electrons are efficiently energized by these waves in the magnetic field aligned direction up to KeV energies confirmed by in situ observations and interacting with cometary or planetary atmospheres producing X-Ray emission by combination of Bremsstrahlung and line K-shell radiation. Analytical study of the nonlinear evolution of MTSI as well as numerical simulations of instability development in the mantle regions of nonmagnetic planets has been performed and it basically confirms the scenario of electron acceleration. Using the above described mechanism of X-ray emission produced in impacts of energetic electrons with ions and neutrals we employed ADAS – atomic data code to analyze X-ray spectrum emitted by comet Linear and obtained a good fit with recent CHANDRA observations. The theoretical model also predicts strong x-ray emission from nonmagnetic planets such as Mars and Venus.
Collective Modes and Linear Landau Damping in a Quark-Gluon Plasma
Authors: Murtaza G , Khattak N A D , Shah H A
Published: September 2005

The semiclassical kinetic approach of Boltzmann-Vlasov model along with the Yang-Mills equation in a covariant guage is used to study Quark-Gluon Plasma. The longitudinal and transverse color collective modes and Landau damping is investigated for extreme and for strongly relativistic cases. The relevant integrals for the polarization tensor are evaluated and the dispersion relations are obtained for both longitudinal and transverse modes. The regime of the QGP wherein the thermal speed of the plasma species equals the velocity of light, the linear Landau damping for the isotropic medium vanishes while for a slight departure from the extreme relativistic case finite mass of the plasma species, the damping term survives.
Properties of Pair-Ion Plasmas using Fullerenes
Authors: Hatakeyama R , Oohara W
Published: September 2005

We have developed a novel method for generating a pair-ion plasma which consists of only positive and negative ions with equal mass. The experimental setup is improved step by step, being suitable for plasma generation through the processes of electron-impact ionization, electron attachment, and magnetic filtering. Density modulations are actively excited by a thick annulus in order to investigate collective electrostatic-modes. Three modes propagating along magnetic-field lines are experimentally found in the pair-ion plasma. The ion acoustic wave and ion plasma wave among them are theoretically predicted, but the new mode is only experimentally found in an intermediate-frequency band between the waves for the first time.
Beyond the Paraxial Approximation in Laser Plasma Interaction
Authors: Abbasi H , Hakimi Pajouh H
Published: September 2005

A generalization of the paraxial approximation based on a stationary transverse distribution of a laser pulse in laserplasma interaction is addressed. The laser beam is assumed to have a nonuniform intensity distribution along its wave front in a plane transverse to the direction of propagation. The conditions are considered in such a way that the pulse variation in the perpendicular direction is negligible. Accordingly, the study is based on an approach that accounts for the transversal effects in an average manner. The dispersion relation is presented in this frame of work by which the electron parametric instability can be studied. It is shown that the correction terms regarding the spot size is just negligible near the symmetry axis, and as off axis points come to play, they grow and consequently their effect might have significant influence in different aspects of the instabilities.
Development of Kolmogorov Spectrum in Pulsar Radio Emission
Authors: Machabeli G Z , Gogoberidze G
Published: September 2005

It is shown that the scattering of electromagnetic waves by Langmuir ones, taking into account the electric drift motion of particles, is the most intense nonlinear process and should be responsible for the formation of the radiation spectrum of radio pulsars. Our analysis indicates that, in the case of existence, inertial interval formation of stationary spectra is possible. Analysis of the linear mechanisms of wave generation and sink allow us to conclude that the only possible stationary solution has the spectral index α = –1.5. The obtained spectrum is in good agreement with observational data.
Emission Altitude from Relativistic Phase Shift Due to Plasma Corotation in Pulsars
Authors: Gangadhara R T
Published: September 2005

The radio emission from a relativistic plasma in a pulsar magnetosphere experiences a relativistic phase shift due to spin and difference in the emission altitude. Using the single pulse data of PSR B0329 + 54 at 325 MHz and 606 MHz we studied the structure of the pulsar emission beam. The distribution of the pulse components around the central core component indicates that the emission beam consists of four nested cones. The asymmetry in the location of the conal components in the leading versus trailing parts of the profile is interpreted as being due to aberration and retardation in the pulsar magnetosphere. These measurements allow us to determine the precise location of the 4 conal rings of emission. We find that the successive outer cones are emitted at higher altitudes in the magnetosphere. Further, for any given cone, the emission height at the lower frequency is found to be larger than that at the higher frequency. We discuss the implications of our new findings on our understanding of the pulsar emission geometry and its impact on the emission mechanisms. The relativistic plasma moving along the dipolar magnetic field lines emit coherent curvature radiation. The beamed emission occurs in the direction of tangents to the field lines, and to receive it, the sight line must align with the tangent within the beaming angle 1/γ, where γ is the particle Lorentz factor. By solving the viewing geometry in an inclined and rotating dipole magnetic field, we show that, at any given pulse phase, the observer tends to receive radiation only from the specific heights allowed by the geometry.
Hall-MHD Turbulence in the Solar Wind
Authors: Krishan V , Mahajan S M
Published: September 2005

The solar wind is a great paradigm for investigating magnetohydrodynamic turbulence. It is shown that the frame work of Hall magnetohydrodynamics (HMHD), which can support three quadratic invariants and allows nonlinear states to depart fundamentally from the Alfvénic, is capable of reproducing in the inertial range the three branches of the observed solar wind magnetic fluctuation spectrum – the Kolmogorov branch f
–5/3 steepening to f
–α1
with α1 ≃ 3–4 on the high frequency side and flattening to f
–1 on the low frequency side. These fluctuations are found to be associated with the nonlinear Hall-MHD Shear Alfvén waves. The spectrum of the concomitant whistler type fluctuations is very different from the observed one. Perhaps the relatively stronger damping of the whistler fluctuations may cause their unobservability. The issue of the anisotropy of the turbulence is addressed briefly.
The Search for Quantum Gravity Using Matter Interferometers
Authors: Bingham R
Published: September 2005

One of the biggest unsolved problems in fundamental physics is the unification of quantum mechanics and gravity. One of the consequences of unification could be the existence of "incoherent conformal waves" in gravitational fields due to quantum mechanical zero-point fluctuations. Recent theories have demonstrated that these fluctuations change the first order correlation function of matterwaves. A spacecraft mission called Hyper is being designed to conduct matterwave experiments in space. An order of magnitude improvement may be gained by going into orbit reducing the effects of environmental interactions. Such experiments could put constraints on the upper bands of measurements of decoherence of a matterwave interferometer due to quantum fluctuations.
Studying Dark Energy with Supernovae: Now, Soon, and the Not-Too-Distant Future
Authors: Saul Perlmutter
Published: September 2005

The nature of the mysterious dark energy is one of the key questions at the intersection of cosmology and string theory—or any fundamental-physics theory. Although dark energy is apparently the dominant constituent of the universe, it is extremely difficult to detect, let alone measure its properties in detail. Our primary route is to measure its effect on the expansion history of the universe; we use Type Ia supernovae as direct indicators of the relative scale of the universe at each moment in history when such a supernova explosion occurred that we can study. The current generation of supernova-measurement projects now in progress are advancing our knowledge of the time-average behavior of dark energy, but we are faced with a daunting challenge when we seek to make a measurement precise—and accurate—enough to distinguish the different dark energy theories by their predictions for the changes in the dark energy's properties over cosmic time. I here highlight some of the recent results and upcoming advances in our approaches to measuring, analyzing, and identifying details of the supernova explosions—including a new satellite design—that are aimed at putting this tantalizing measurement within our grasp.
Prospects of Inflation
Authors: Andrei Linde
Published: September 2005

I will discuss the development of inflationary theory and its present status, including recent progress in describing de Sitter space and inflationary universe in string theory.
A Non Singular Universe
Authors: Stephen Hawking
Published: September 2005

The last chapter of my PhD thesis, contained my first singularity
theorem. This showed that under certain reasonable conditions,
any cosmological solution of the field equations, would have a big
bang singularity. At this singularity, classical general relativity
would break down, so one could not use it to predict how the
universe began. It was therefore necessary to develop a quantum
theory of gravity, in order to understand the origin of the universe.
In this talk, I explore if the
origin of the universe can be semi classical, and non singular. This
is possible despite the singularity theorems, because like so many
other no go theorems, they have a get out clause. In this case, the
get out is the strong energy condition.
Unconventional Scenarios and Perturbations Therein
Authors: G Veneziano
Published: September 2005

After introducing a class of string-inspired unconventional cosmologies, I will discuss the spectra of adiabatic scalar and tensor perturbations therein. On the basis of a toy model I will argue that those spectra are quite likely too `blue' to be responsible for the observed large-scale structure of our Universe. I will then discuss a possible way out of this impasse whereby a scale-invariant spectrum of adiabatic density fluctuations emerges through the early decay of the Kalb–Ramond axion of string theory.
Beyond Inflation: A Cyclic Universe Scenario
Authors: Neil Turok  , Paul J Steinhardt
Published: September 2005

Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both high energy and low energy inflation, with energy densities differing by a hundred orders of magnitude. The questions of why the universe started out undergoing high energy inflation, and why it will end up in low energy inflation, are unanswered. Rather than resort to anthropic arguments, we have developed an alternative cosmology, the cyclic universe, in which the universe exists in a very long-lived attractor state determined by the laws of physics. The model shares inflation's phenomenological successes without requiring an epoch of high energy inflation. Instead, the universe is made homogeneous and flat, and scale-invariant adiabatic perturbations are generated during an epoch of low energy acceleration like that seen today, but preceding the last big bang. Unlike inflation, the model requires low energy acceleration in order for a periodic attractor state to exist. The key challenge facing the scenario is that of passing through the cosmic singularity at t = 0. Substantial progress has been made at the level of linearised gravity, which is reviewed here. The challenge of extending this to nonlinear gravity and string theory remains.
Creating Naked Singularities and Negative Energy
Authors: Gary T Horowitz
Published: September 2005

A brief review is given of three recent results concerning classical solutions of gravitational theories: (1) With asymptotically anti de Sitter boundary conditions, there are matter theories satisfying the positive energy theorem which violate cosmic censorship. (2) Despite supersymmetry, there are solutions to 𝒩 = 8 supergravity in which the total gravitational energy is arbitrarily negative. This theory can also violate cosmic censorship. (3) A large class of supersymmetric compactifications (including all simply connected Calabi–Yau manifolds) have solutions with negative four dimensional effective energy density.
Cosmological Singularities in String Theory
Authors: David Kutasov
Published: September 2005

I briefly review some recent work on the physics associated with a certain class of cosmological singularities in string theory.
Where Do We Stand in Fundamental (String) Theory
Authors: David J Gross
Published: September 2005

I review the current state of string theory and the problems that it faces in addressing the fundamental problems of cosmology.
First International Meeting on Applied Physics (APHYS-2003)
Authors: A Méndez-Vilas  , R Chacón
Published: September 2005

This special issue of Physica Scripta contains papers presented at the 1st International Meeting on Applied Physics (APHYS-2003), held in Badajoz (Spain), from 13th to 18th October 2003, and more specifically, selected papers presented during the conference sessions mainly on Applied Optics, Laser Physics, Ultrafast Phenomena, Optical Materials, Semiconductor Materials and Devices, Optoelectronics, Quantum Electronics and Applied Solid State Physics-Chemistry.
APHYS-2003 was born as an attempt to create a new international forum on Applied Physics in Europe. Since Applied Physics is not really a branch of Physics, but the application of all the branches of Physics to the broad realms of practical problems in Science, Engineering and Industry, this conference was a truly multi and inter-disciplinary event. The organizers called for papers relating Physics with other sciences such as Biology, Chemistry, Information Science, Medicine, etc, or relating different Physics areas, and aimed at solving practical problems. In other words, the Conference was specifically interested in reports applying the techniques, the training, and the culture of Physics to research areas usually associated with other scientific and engineering disciplines.
It was extremely rewarding that over 800 researchers, from over 65 countries, attended the conference, where more than 1000 research papers were presented. We feel really proud of this excellent response obtained (in number and quality), for this first edition of the conference.
We are very grateful to all the members of the Organizing Committee, for the hard work done for the preparation of the Conference (which began one year before the conference start), and to the members of the International Advisory Committee, for the valuable contribution to the evaluation of submitted works. Also thank to the referees for the excellent work done in the revision of submitted papers.
Finally, we would like to thank the Department of Physics of the University of Extremadura, for their support, and the Regional Government (Junta de Extremadura/Consejería de Educación, Ciencia y Tecnología), as well as INNOVA Instrumentación, for sponsoring the Conference.
X-Ray Fluorescence Excited with Protons and Heavy Ions, the Cross Sections Curve
Authors: C M Romo-Kröger
Published: September 2005

X-ray fluorescence is a matter of study in fundamental research, in material analysis and in applied research, like for analytical purposes and even the fluorescence in the galactic space produced by cosmic rays. One of the most important parameters in x-ray fluorescence is the ionization cross section which presents a definite target atom to an incident projectile ion, in the case of excitation with particles. Here is presented an analytic curve to describe the ionization cross sections for a variety of target atoms (Z = 13–40) bombarded with protons (energies from a few keV to some tens of MeV). This is a sort of universal curve, for any target at any proton energy. More even, this curve serves to evaluate the ionization cross sections with other heavier ions as incident particles. That is, deuterons and alpha particles and also the so called heavy ions (typically with Z over 6). By means of a scaling law, derived from the Plane Wave Born Approximation (PWBA), the cross sections for a heavier ion can be displayed in the same curve as that for protons. For heavy ions, however, there are other physical phenomena not considered in the PWBA model. That deviates the result for heavy ions from the original curve for protons. Introducing new parameters, according to the heavy ions physics, we can get some success to fit the experimental data in a sole curve. Cross sections data from current literature are included in the construction of this fitted curve.
Deposition of Saharan Dust in Monaco Rain 2001–2002: Radionuclides and Elemental Composition
Authors: M K Pham  , J J La Rosa  , S-H Lee  , B Oregioni  , P P Povinec
Published: September 2005

Data on concentrations and activity ratios of natural and anthropogenic radio-nuclides as well as concentrations of major and trace elements in red-coloured particles (Saharan dusts) collected in Monaco rain in 2001 and 2002 (5 samples from 4 events) are presented. Different distributions of particle size as well as different activities of natural radionuclides and concentrations of trace metals have been observed for two sets of samples. The 235U/238U activity ratio is around 0.04 showing virgin natural terrestrial origin of the particles. The anthropogenic radionuclides 137Cs, 238Pu, 239+240Pu and 241Am are of global fallout origin and their annual atmospheric input to the ocean in the particulate form is estimated to be 28–37% for 137Cs, 34–45% for 239+240Pu and 36–51% for 241Am of the total annual depositional fluxes of these radionuclides to the northwest Mediterranean.
Radiation Effects on Electrical Conductivity of Proton Conducting Oxide Ceramics
Authors: B Tsuchiya  , A Moroño  , E R Hodgson  , T Shikama
Published: September 2005

Radiation Induced Conductivity (RIC) of proton conducting oxide ceramics (SrCe0.95Yb0.05O3-δ) was studied using 1.8 MeV electrons at an ionization dose rate of 10 Gy/s. The observed RIC was enhanced by an increase of the base conductivity without radiation as the irradiation temperature was increased from 298 to 673 K, due to Radiation Induced Electrical Degradation (RIED). It was found that the degradation rate of the base conductivity was strongly dependent on irradiation temperature and fluence.

It was also found that the base conductivity at temperatures above about 433 K did not change due to electron irradiation at the total ionization dose of 2.85 MGy. The result indicates that the radiation effect by the electrons has no influence on protonic or ionic conduction.
A Multiple Regression Analysis Between UV Radiation Measurements at Badajoz and Ozone, Reflectivity and Aerosols Estimated by TOMS
Authors: M Antón  , M L Cancillo  , A Serrano  , J A García
Published: September 2005

This paper analyzes the relationship between ultraviolet erythemal radiation (UVER) measured in Badajoz (Spain) and ozone, cloudiness and aerosols. Initially, the values of transmissivity of UVER are related with three parameters (ozone amount, reflectivity and aerosol index) estimated by the satellite instrument TOMS. The relative importance and dependence of each variable is analyzed by means of a multiple regression analysis with an expression derived from the Lambert-Bouger-Beer law. The results indicate that the aerosol index is not a statistically significant factor for the initial expression. Then, a partial model with only ozone and reflectivity as regressors is proposed and coefficients are obtained using UVER measurements of year 2001. Finally the model is validated comparing its prediction for 2002 with UVER measurements at ground. The agreement between both data sets is reasonably good, suggesting that UVER estimations can be successfully derived from observations of other atmospheric variables, thus providing the basis to obtain spatial distributed maps of UV variations.
Solar Global Radiation and Sunshine Duration in Extremadura (Spain)
Authors: M L Cancillo  , A Serrano  , A Ruiz  , J A García  , M Antón  , J M Vaquero
Published: September 2005

This paper aims at analysing the relationship of solar global irradiation and sunshine duration at three stations in Extremadura (Spain) at a daily and monthly basis. Studying this dependence is of great interest since it allows to estimate solar irradiation in many stations where sunshine duration is measured and then, extend the number of locations with data, in order to plot reliable solar radiation spatial distributed maps. The mentioned relationship is investigated at both daily and monthly basis, by fitting the Ångström-Prescott model by regression techniques. The correlation coefficients show notably high values for the three locations, suggesting the suitability of the model for the measured data. Moreover, the regression coefficients are in agreement with those obtained in other works for different locations in the Iberian Peninsula. In the daily analysis, it is also found that residuals show a smooth annual behaviour and, therefore, Ångström-Prescott model was fitted for each calendar month separately. The annual evolution of the regression coefficients and the atmospheric transparency index is analysed and compared for the three stations of measurements.
PM10 and PM2.5 Mass Concentration Measurements in Belgrade Urban Area
Authors: M D Tasić  , S F Rajšić  , V T Novaković  , Z R Mijić  , M N Tomašević
Published: September 2005

In order to assess the level of mass concentrations of ambient suspended particles PM10 and PM2.5, a pilot study was performed in the urban area of Belgrade, in winter and summer period from June 2002 to June 2003. The PM10 mass concentrations in Belgrade urban area were high (average value being 72 µg m-3) in comparison to other European cities and more than 68% of daily samples exceeded the limit value of 50 µg m-3. Average PM2.5 mass concentration was 61 µg m-3. Analysis of the PM10 mass concentrations indicated seasonal variation. Frequency distribution of PM10 and PM2.5 mass concentrations and wind speed was best represented by log-normal distribution. Physical and chemical characterization of suspended particulate matter was accomplished by electron microscopy methods.