bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporating spectral characteristics of Pc5 waves into three‐dimensional radiation belt modeling and the diffusion of relativistic electrons
Authors: Perry K. L. , Hudson M. K. , Elkington S. R.
Published: March 2005

The influence of ultralow frequency (ULF) waves in the Pc5 frequency range on radiation belt electrons in a compressed dipole magnetic field is examined. This is the first analysis in three dimensions utilizing model ULF wave electric and magnetic fields on the guiding center trajectories of relativistic electrons. A model is developed, describing magnetic and electric fields associated with poloidal mode Pc5 ULF waves. The frequency and L dependence of the ULF wave power are included in this model by incorporating published ground‐based magnetometer data. It is demonstrated here that realistic spectral characteristics play a significant role in the rate of diffusion of relativistic electrons via drift resonance with poloidal mode ULF waves. Radial diffusion rates including bounce motion show a weak pitch angle dependence for αeq ≥ 50° (λ ≤ 20°) for a power spectral density which is L‐independent. The data‐based model for greater power at higher L values yields stronger diffusion at αeq = 90°. The L6 dependence of the diffusion coefficient which is obtained for a power spectral density which is L‐independent is amplified by power spectral density which increases with L. During geomagnetic storms when ULF wave power is increased, ULF waves are a significant driver of increased fluxes of relativistic electrons inside geosynchronous orbit. Diffusion timescales obtained here, when frequency and L dependence comparable to observations of ULF wave power are included, support this conclusion.
Modeling radio scattering and scintillation observations of the inner solar wind using oblique Alfvén/ion cyclotron waves
Authors: Harmon John K. , Coles William A.
Published: March 2005

Radio scattering and scintillation observations of the near‐Sun solar wind are shown to be dominated by effects associated with obliquely propagating Alfvén/ion cyclotron waves. We base this on a modeling of structure functions from angular/spectral broadening observations and velocity measurements from interplanetary scintillation (IPS) observations. A simple damped‐WKB model was found inadequate, as Landau damping erodes the spectrum faster than is consistent with the observed inner scale. Invoking a turbulent cascade can counteract this damping and push the spectral cutoff back out to the observed inner scale near the ion inertial scale. Adjusting the spectrum amplitude and cascade rate to match observations gives an estimate of the wave dissipation power associated with electron Landau damping and proton cyclotron damping. The implied power levels are substantial, being comparable with levels typically invoked in extended wave heating models. Both the shape and the amplitude of the observed structure functions can be explained by a composite spectrum made up of a power law component of passive or non‐Alfvénic density fluctuations and a local flattening associated with the enhanced linear Alfvén wave compressibility at small (ion cyclotron) scales. Since IPS is dominated by the enhanced small‐scale density fluctuations, the scintillation velocity field should show a strong wave effect. Our modeling of IPS velocities does, in fact, show that the large parallel velocity spread and upward bias to the mean velocity observed near the Sun are a direct result of the density fluctuations associated with Alfvén waves along an extended line of sight.
Observations on the characteristics of tides in the Bab el Mandab Strait
Authors: Jarosz Ewa , Murray Stephen P. , Inoue Masamichi
Published: March 2005

While well known for its multilayered exchange flow, the Bab el Mandab Strait is also of interest as a transitional region between two distinctly different tidal regimes: the Gulf of Aden, where tides are mixed and have a range in excess of 2 m, and the Red Sea, where tidal fluctuations are principally semidiurnal and their range is generally less than 1 m. Observations collected in the strait indicate that dominant constituents for both elevations and currents are the K1 and M2. The vertical structure of the tidal currents differs between semidiurnal and diurnal constituents and depends on the location and stratification. The major part of the tidal signal is barotropic, but energetic baroclinic currents mainly of the diurnal period are observed near Perim Narrows and the Hanish Sill during winter months. The relationship between the barotropic currents and surface tides near Perim is fairly well explained by a simple momentum balance. To first order, a balance exists between local acceleration and the elevation gradient in the along‐strait direction, while in the cross‐strait direction, a balance between local acceleration, Coriolis term, and elevation gradient is observed. At the same location the barotropic transport fluctuations reach amplitudes of 1.6 Sv. The K1 and M2 barotropic energy fluxes are small and are directed into the strait at Perim Narrows and the Hanish Sill for the M2 constituent and into the strait near Perim and out of the strait near Hanish for the K1 constituent.
On the fine structure of thunderstorms leading to the generation of sprites and elves: Fractal analysis
Authors: Hayakawa M. , Nakamura T. , Iudin D. , Michimoto K. , Suzuki T. , Hanada T. , Shimura T.
Published: March 2005

The fine structure of convective clouds leading to the generation of sprites and elves has been studied using radar images. Sprites and elves were observed on two days, 19 December 1998 and 27 January 1999, in lightning during winter thunderstorms on the Sea of Japan. Fractal analyses of the radar images (as an ensemble and as separate clusters) for those two days have been performed with respect to the occurrence of sprites and elves. We have found that a sprite and/or an elve is triggered when and just after the image cluster maximum size increases to a certain value (∼150 km) and the ensemble fractal dimension approaches a threshold (i.e., percolation threshold).
Improved representation of diurnal variability of rainfall retrieved from the Tropical Rainfall Measurement Mission Microwave Imager adjusted Precipitation Estimation From Remotely Sensed Information Using Artificial Neural Networks (PERSIANN) system
Authors: Hong Yang , Hsu Kuo‐Lin , Sorooshian Soroosh , Gao Xiaogang
Published: March 2005

Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN) is a satellite infrared‐based algorithm that produces global estimates of rainfall at resolutions of 0.25° × 0.25° and a half‐hour. In this study the model parameters of PERSIANN are routinely adjusted using coincident rainfall derived from the Tropical Rainfall Measurement Mission Microwave Imager (TMI). The impact of such an adjustment on capturing the diurnal variability of rainfall is examined for the Boreal summer of 2002. General evaluations of the PERSIANN rainfall estimates with/without TMI adjustment were conducted using U.S. daily gauge rainfall and nationwide radar network (weather surveillance radar) 1988 Doppler data. The diurnal variability of PERSIANN rainfall estimates with TMI adjustment is improved over those without TMI adjustment. In particular, the amounts of afternoon and morning maximums in rainfall diurnal cycles improved by 14.9% and 26%, respectively, and the original 2–3 hours of time lag in the phase of diurnal cycles improved by 1–2 hours. In addition, the rainfall estimate with TMI adjustment has higher correlation (0.75 versus 0.63) and reduced bias (+8% versus −11%) at monthly 0.25° × 0.25° resolution than that without TMI adjustment and consistently shows higher correlation (0.62 versus 0.51) and lower bias (+22% versus −30%) at daily 0.25° × 0.25° scale. This study provides evidence that the TMI, which measures instantaneous rain rates from the TRMM platform flying on a non‐Sun‐synchronous orbit, enables PERSIANN to capture more realistic diurnal variations of rainfall. This study also reveals the limitation of current satellite rainfall estimation techniques in retrieving the rainfall diurnal features and suggests that further investigation of precipitation generation in different periods of cloud life cycles might help resolve this limitation.
A proper approach for nonequilibrium molecular dynamics simulations of planar elongational flow
Authors: Baig C. , Edwards B. J. , Keffer D. J. , Cochran H. D.
Published: March 2005

We present nonequilibrium molecular dynamics simulations of planar elongational flow (PEF) by an algorithm proposed by Tuckerman et al. [J. Chem. Phys. 106, 5615 (1997)] and theoretically elaborated by Edwards and Dressler [J. Non-Newtonian, Fluid Mech. 96, 163 (2001)], which we shall call the proper-SLLOD algorithm, or p-SLLOD for short. [For background on names of algorithms see W. G. Hoover, D. J. Evans, R. B. Hickman, A. J. C. Ladd, W. T. Ashurst, and B. Moran, Phys. Rev. A 22, 1690 (1980) and D. J. Evans and G. P. Morriss, Phys. Rev. A 30, 1528 (1984).] We show that there are two sources for the exponential growth in PEF of the total linear momentum of the system in the contracting direction, which has been previously observed using the so-called SLLOD algorithm. The first comes from the SLLOD algorithm itself, and the second from the implementation of the Kraynik and Reinelt [Int. J. Multiphase Flow 18, 1045 (1992)] boundary conditions. Using the p-SLLOD algorithm (to eliminate the first source) implemented with our simulation strategy (to eliminate the second) in PEF simulations, we no longer observe the exponential growth. By analyzing the equations of motion, we also demonstrate that both the SLLOD and the DOLLS algorithms are intrinsically unsuitable for representing a nonequilibrium system with elongational flow. However, the p-SLLOD algorithm has a rigorously canonical structure in laboratory phase space, and thus can represent a nonequilibrium system not only for elongational flow but also for a general flow.
Molecular alignment of ammonia studied by electron-ion-ion coincidence spectroscopy
Authors: Lindgren Andreas , Gisselbrecht Mathieu , Burmeister Florian , Naves de Brito Arnaldo , Kivimäki Antti , Sorensen Stacey L.
Published: March 2005

Electron-ion-ion coincidence measurements carried out at discrete resonances near the N 1s threshold in ammonia are reported. The measured coincidence spectra show clear alignment of the molecule upon resonant core-electron excitation. The coincidence data are analyzed to extract information about the molecule in the excited state by simulating the alignment and the dissociation processes. Dynamic changes in molecular geometry are found as the photon energy is scanned through the N 1s→4a1 resonance, whereas for the N 1s→2e state the geometry and kinetic energy released upon dissociation remain unchanged. The alignment of the core-excited molecules is found to be preserved even in two-step dissociation processes.
The dynamics of single chains within a model polymer melt
Authors: McCormick Julie A. , Hall Carol K. , Khan Saad A.
Published: March 2005

Discontinuous molecular dynamics simulations are performed on a system containing 32 hard chains of length 192 at a volume fraction of ϕ=0.45 to explore the idea that localized entanglements have a significant effect on the dynamics of the individual chains within an entangled polymer melt. Anomalous behavior can still be observed when studying the dynamics of the individual chains, although increased time averaging causes the anomalous relaxation-memory-release behavior that was observed previously in the system to smooth out. First, the individual chain mean squared displacements and apparent diffusion coefficients are calculated, and a wide distribution of diffusive behavior is found. Although the apparent diffusion coefficient curve averaged over all chains displays the predicted long-time diffusive behavior, the curves for the individual chains differ both qualitatively and quantitatively. They display superdiffusive, diffusive, and subdiffusive behavior, with the largest percentage of chains exhibiting superdiffusive behavior and the smallest percentage exhibiting the predicted diffusive behavior. Next, the individual chain end-to-end vector autocorrelation functions and relaxation times are determined, and a wide distribution of stress relaxation behavior is found. The times when the end-to-end vector autocorrelation functions relax completely span almost an order of magnitude in reduced time. For some chains, the end-to-end vector autocorrelation function relaxes smoothly toward zero similar to the system average; however, for other chains the relaxation is slowed greatly, indicating the presence of additional entanglements. Almost half of the chains exhibit the anomalous behavior in the end-to-end vector autocorrelation function. Finally, the dynamic properties are displayed for a single chain exhibiting anomalous relaxation-memory-release behavior, supporting the idea that the relaxation-memory-release behavior is a single-chain property.
Existence of the semilocal Chern–Simons vortices
Authors: Chae Dongho
Published: March 2005

We consider the Bogomol’nyi equations of the Abelian Chern–Simons–Higgs model with SU(N)global⊗U(1)local symmetry. This is a generalization of the well-known Abelian Chern–Simons–Higgs model with U(1)local symmetry. We prove existence of both topological and nontopological multivortex solutions of the system on the plane.
Effect of interfacial diffusion on microstructure and magnetic properties of Cu∕FePt bilayer thin films
Authors: Chen S. K. , Yuan F. T. , Chin T. S.
Published: March 2005

The crystal structure, microstructure, and magnetic properties for a series of Cu∕FePt bilayer films were investigated. The samples were prepared by depositing a Cu top layer on a highly ordered L10 FePt film. To promote interdiffusion, the bilayer samples were annealed at a temperature Td ranging from 300to800°C. X-ray diffraction data indicate that observable diffusion occurs at 400°C. The maximum coercivity thus obtained is 14.0kOe, which is 24% larger than that of the ordered FePt film without a Cu top layer. The high Hc can be attributed to the diffusion of copper atoms through the grain boundaries of the magnetic films, which may produce extra pinning sites for domain-wall movement. The ΔM data measured from the Henkel plots of annealed Cu∕FePt films change from negative to positive values as Td is raised from 400to800°C. This can result from the effects of demagnetization coupling and exchange coupling and is further explained from the variation of squareness ratios of hysteresis loops.
Micromagnetic configurations and switching mechanism in Pac-man-shaped submicron Ni80Fe20 magnets
Authors: Pujada B. R. , Choi B. C. , Park M. H. , Hong Y. K. , Gee S. H. , Han H. , Donohoe G. W.
Published: March 2005

Micromagnetic modeling analysis and magnetic force microscopy studies were performed in order to characterize the magnetization configuration and magnetic switching behavior in two types, PM I and PM II, of submicron Pac-man-shaped Ni80Fe20 magnetic elements. It was found that a slight variation in the shape of the elements has a striking influence on the internal magnetic structures and switching field distribution. In particular, the vortex-formation driven switching is replaced by quasicoherent reversal by removing the central core part at the center of element. The sensitive dependence of remanent magnetic configuration and switching behavior on sample geometry is discussed in terms of the competition between the exchange and demagnetizing energy terms.
Twelve-fold increase of diffraction efficiency of thermally fixed holograms in Bi12SiO20
Authors: Arizmendi L. , López-Barberá J. F. , Carrascosa M.
Published: March 2005

The effect of a dc electric field on the diffraction efficiency of thermally fixed holograms in Bi12SiO20 is studied. The theory predicts an increasing effect similar to that produced by the photovoltaic effect in other photorefractive materials. Experimentally, more than a 12-fold increase in the diffraction efficiency is observed for an applied field of 6300V∕cm. The decay times of the fixed holograms at different temperatures have also been studied. An activation energy of 1.4eV is obtained for this process. The extrapolated lifetime at room temperature is longer than 104 years. Hydrogen impurities are proposed as the ions responsible for fixing.
Gate-refreshable nanowire chemical sensors
Authors: Fan Zhiyong , Lu Jia G.
Published: March 2005

ZnO nanowire field effect transistors were implemented as highly sensitive chemical sensors for detection of NO2 and NH3 at room temperature. Due to a Debye screening length comparable to the nanowire diameter, the electric field applied over the back gate electrode was found to significantly affect the sensitivity as it modulates the carrier concentration. A strong negative field was utilized to refresh the sensors by an electrodesorption mechanism. In addition, different chemisorbed species could be distinguished from the “refresh” threshold voltage and the temporal response of the conductance. These results demonstrated a refreshable field effect sensor with a potential gas identification function.
Electrodeposition of bismuth thin films on n-GaAs (110)
Authors: Vereecken Philippe M. , Rodbell Kenneth , Ji Chunxin , Searson Peter C.
Published: March 2005

Bismuth thin films are formed electrochemically on n-GaAs (110). Bismuth films up to a few hundred nanometers in thickness exhibit a strong (018) texture, while thicker films are polycrystalline. The barrier height of the n-GaAs∕Bi Schottky contacts is 0.62eV, about 0.2eV lower than for electrodeposited bismuth films on GaAs (100).
Emission behavior of nm-thick Al2O3 film-based planar cold cathodes for electronic cooling
Authors: Lee Myoung-Bok , Hahm Sung-Ho , Lee Jung-Hee , Song Yoon-Ho
Published: March 2005

We have fabricated and investigated the emission characteristics of planar cold cathodes which are appropriate for the electronic cooling devices by atomically depositing ultrathin Al2O3 films onto the indium-tin-oxide-coated glass. A diode-type test indicated prominent emission behaviors, such as a low threshold field of 3–5V∕μm for planar cold cathodes and the nonuniform luminescence intensity with localized distribution of emission spots. We propose a resonant Fowler–Nordheim tunneling of electrons transported via the Frenkel traps with a well depth of ϕB=0.8–0.9eV in nm-thick Al2O3 films as a key process for the extraordinary emission properties of Al2O3 film-based planar cold cathodes.
The Crystal Structures at 10 K of the Trigonal Salts
KMIII(NH3)6(ClO4)2Cl2, MIII = Os and Cr, and the Possibility of Phase Transitions
Authors: Reynolds Philip A. , Figgis Brian N. , Sobolev Alexander N.
Published: March 2005

The crystal structures of
KOs(NH3)3(ClO4)2Cl2
and
KCr(NH3)6(ClO4)2Cl2
were determined at 10 K by X-ray diffraction, and for the osmium salt also at
293 K. At 293 K the osmium salt is trigonal, space group
R 3m, with the same simple
structure as others of this class of double salt. At 10 K, in agreement with
previous radius ratio predictions, both crystals are best described as
remaining R 3m. All previously
studied members, with larger alkali metal cations, are twinned
R 3 at low temperatures, with small, symmetry-breaking
rotations of the hexaamminemetal(III) and perchlorate ions about the threefold
axis. Differential scanning calorimetry on
CsRu(NH3)6(ClO4)2Cl2
suggests that the R 3m to
R 3 change is very extended in temperature with only a
small discontinuity at the transition temperature.
Solid State Coordination Chemistry of Pyridinedicarboxylic Acid Isomers. I Copper(II) Disodium Bis(pyridine-2,3- dicarboxylate) Octahydrate and Copper(II) Pyridine-3,4-dicarboxylate 3·5 Hydrate
Authors: Sileo Elsa E. , Vega Daniel , Garland Mará T. , Baggio Ricardo , Blesa Miguel A.
Published: March 2005

The crystal structures of
Na2Cu(2,3-pydc)2.8H2O
(1) and Cu(3,4-pydc).3·5H2O (2) (pydc =
pyridinedi- carboxylato) are presented. Compound (1) is monoclinic, space
group C 2/c, with
a 21·274(1), b 6
·114(1), c 17·136(1) Å, β
101·62(1)°, Z 4,
Dc 1·776 g
cm-3 ; compound (2) is also monoclinic, space group
P 21/c,
with a 7·272(2), b
11·319(3), c 25·453(9) Å, β
90·58(1)°, Z 4,
Dc 1·850 g
cm-3 . Their stereochemistries are analysed, and
compared with other copper(II) pyridine-2,6-dicarboxylates. Ligand constraints
are shown to determine the crystal structures and the magnetic properties.
Thermal dependence of magnetic susceptibility data and t.g., d.t.g. and d.t.a.
measurements are also presented.
Studies Towards the Synthesis of Phorbazoles A - D: Formation of the Pyrrole Oxazole Skeleton
Authors: Loughlin Wendy A. , Muderawan I. Wayan , McCleary Michelle A. , Volter Katie E. , King Malcolm D.
Published: March 2005

Synthetic approaches towards the synthesis of the pyrrole oxazole skeleton of
phorbazoles A–D are described. An efficient synthesis of the pyrrole
oxazole skeleton (19) from pyrrole and 4- methoxyacetophenone was developed.
In the key step, cyclodehydration of the amide (16) resulted in formation of
the diprotected pyrrole oxazole (17). Subsequent deprotection of the
diprotected pyrrole oxazole (17) gave the target phorbazole skeleton (19).
The S2 Oxygen Atoms Are Essential for the Pronounced Fungitoxicity of the Sulfur-Rich Natural Product, Dysoxysulfone
Authors: Bewick Sharon A. , Duffy Stephen , Fletcher Stephen P. , Langler Richard F. , Morrison Heather G. , O'Brien Erin M. , Ross Charles , Stephenson Vanessa C.
Published: March 2005

Synthesis and antifungal testing of 2,4,5,7,9-pentathiadecane 9,9-dioxide has established that the absence of oxygen atoms on S2 significantly attenuates fungitoxicity in accord with our earlier proposal. Attempts to convert that compound into dysoxysulfone led to the discovery of a novel oxidative conversion of unsymmetrical γ-sulfonyl disulfides into the corresponding symmetrical γ-sulfonyl disulfides.
A Hydroformylation Route to Diazabicycloalkanes and Oxazabicycloalkanes Containing Medium and Large Rings
Authors: Bergmann David J. , Campi Eva M. , Jackson W. Roy , Patti Antonio F.
Published: March 2005

Diazabicycloalkanes and oxazabicycloalkanes containing medium and large rings
can be prepared by rhodium-catalysed reactions of
N-alkenylpropane-1,3-diamines and
2-(alkenylamino)ethanols with H2/CO in excellent
yields without the need for high dilution. Selective ring opening of these
compounds can lead to large heterocycles.
Host-Guest Complexation of Aromatic Carboxylic Acids and their Conjugate Bases by β-Cyclodextrins Monosubstituted at C 6 by Linear and Cyclic Alkyl Triamines in Aqueous Solution
Authors: Kean Suzanna D. , May Bruce L. , Clements Philip , Easton Christopher J. , Lincoln Stephen F.
Published: March 2005

A pH titrimetric study of the complexation of the guests benzoic acid,
4-methylbenzoic acid and (R)- and
(S)-2-phenylpropanoic acids and their conjugate bases by
the host
6A-[2-(2-aminoethylamino)ethylamino]-,
6A-[3-(3-aminopropylamino)propylamino]-,
6A-(1,4,7-triazacyclononan-1-yl)-, and
6A-(1,5,9-triazacyclododecan-1-yl)-6A-deoxy-β-cyclodextrins
(βCDdien, βCDdipn, βCDtacn and βCDtacdo, respectively) is
reported. Over the pH range 3.0–11.0, 49 host–guest complexes were
detected. Their stability constants (K) range from
220±50 dm3 mol–1 for
the βCDdienH22+
·benzoate– complex to 48000±11000
dm3 mol–1 for the
βCDdipnH22+·(S)-2-phenylpropanoic
acid complex at 298.2 K and I = 0.10 mol
dm–3 (NaClO4). The latter
K value is among the highest reported for a complex of a
simple carboxylic acid with a substituted β-cyclodextrin. The charge,
hydrophobicity and stereochemistry of both host and guest appear to be
significant factors in the variation of host–guest complex stability.
1H ROESY n.m.r. studies of some of the complexes formed
are also reported.
Studies in the Cycloproparene Series: Approaches to Cyclopropa[b]tetracenes
Authors: Halton Brian , Evans David A. C. , Warrener Ronald N.
Published: March 2005

Cyclopropa[b]naphthalene-3,6-dione (2) fails
to add furan across the enedione olefinic bond in a Diels–Alder
cycloaddition even at 14 × 105 kPa. In contrast,
isobenzofuran (4) adds efficiently at ambient temperature and pressure. The
epoxytetracenedione (5) that is formed is air-sensitive and decomposes under
conditions employed for dehydration. Aromatization of (5) to
cyclopropatetracenedione (6) is not observed despite anthracene-1,4-dione (8)
being obtained from its analogous tetrahydro precursor (7) under the same
conditions.
Reaction of 2-Acetoxy-3-chloro and 2,3-Diacetoxy Naphthoquinones with 1,3-Dioxy and 1,1,3-Trioxy Butadienes
Authors: Cameron Donald W. , Riches Andrew G.
Published: March 2005

Reaction of 2-acetoxy-3-chloro naphthoquinones towards the 1,3-dioxy diene (2)
and the 1,1,3-trioxy diene (9) was examined. The competing influence of the
acetoxy and chloro substituents was assessed from the regiochemistry of the
resulting Diels–Alder chemistry, as was competition between that process
and Michael addition/elimination. Reaction of the same dienes towards the
less reactive 2,3-diacetoxy naphthoquinone (25) was also
investigated.
Synthesis of 2,3-Dioxy-1,4-anthraquinones Related to Tetracenomycins C and X
Authors: Cameron Donald W. , Griffiths Peter G. , Riches Andrew G.
Published: March 2005

The 2,3-dioxy-1,4-anthraquinones (6) and (7) have been synthesized from the
9,10-anthraquinone (19), through the anthrone (18). Quinones (6) and (7)
respectively possess substituents appropriate for three of the four rings of
tetracenomycins C (2) and X (3) but they did not show dienophilic properties
towards the reactive diene (5). Interaction with the diene was complicated by
transsilylation, as was also observed for the model quinone
(25).
Insulin-stimulated Plasma Membrane Fusion of Glut4 Glucose Transporter-containing Vesicles Is Regulated by Phospholipase D1
Authors: Huang Ping , Altshuller Yelena M. , Hou June Chunqiu , Pessin Jeffrey E. , Frohman Michael A.
Published: March 2005

Insulin stimulates glucose uptake in fat and muscle by mobilizing Glut4 glucose transporters from intracellular membrane storage sites to the plasma membrane. This process requires the trafficking of Glut4-containing vesicles toward the cell periphery, docking at exocytic sites, and plasma membrane fusion. We show here that phospholipase D (PLD) production of the lipid phosphatidic acid (PA) is a key event in the fusion process. PLD1 is found on Glut4-containing vesicles, is activated by insulin signaling, and traffics with Glut4 to exocytic sites. Increasing PLD1 activity facilitates glucose uptake, whereas decreasing PLD1 activity is inhibitory. Diminished PA production does not substantially hinder trafficking of the vesicles or their docking at the plasma membrane, but it does impede fusion-mediated extracellular exposure of the transporter. The fusion block caused by RNA interference-mediated PLD1 deficiency is rescued by exogenous provision of a lipid that promotes fusion pore formation and expansion, suggesting that the step regulated by PA is late in the process of vesicle fusion.
ASIC3: A Lactic Acid Sensor for Cardiac Pain
Authors: Immke D.C. , McCleskey E.W.
Published: March 2005

Angina, the prototypic vasoocclusive pain, is a radiating chest pain that occurs when heart muscle gets insufficient blood because of coronary artery disease. Other examples of vasoocclusive pain include the acute pain of heart attack and the intermittent pains that accompany sickle cell anemia and peripheral artery disease. All these conditions cause ischemia � insufficient oxygen delivery for local metabolic demand — and this releases lactic acid as cells switch to anaerobic metabolism. Recent discoveries demonstrate that sensory neurons innervating the heart are richly endowed with an ion channel that is opened by, and perfectly tuned for, the lactic acid released by muscle ischemia[1,2].
The Insulin-Sensitive Side of SHIP2
Authors: Schurmans Stephane
Published: March 2005

A substantial and increasing proportion of death and disability in the EU (and elsewhere) is attributable to diseases associated with insulin resistance (i.e., decreased insulin sensitivity). Beside type II diabetes, other diseases like obesity, hypertension, atherosclerosis, hyperlipidaemia, polycystic ovarian syndrome, and acromegaly are indeed associated with insulin resistance [1].
Breaking Immunological Tolerance through OX40 (CD134)
Authors: Bansal-Pakala Pratima , Croft Michael
Published: March 2005

Immunological tolerance represents a mechanism by which cells of the host remain protected from the immune system. Breaking of immunological tolerance can result in a variety of autoimmune diseases such as rheumatoid arthritis, diabetes, and multiple sclerosis. The reasons for tolerance breaking down and autoimmune processes arising are largely unknown but of obvious interest for therapeutic intervention of these diseases. Although reversal of the tolerant state is generally unwanted, there are instances where this may be of benefit to the host. In particular, one way a cancerous cell escapes being targeted by the immune system is through tolerance mechanisms that in effect turn off the reactivity of T lymphocytes that can respond to tumor-associated peptides. Thus tolerance represents a major obstacle in developing effective immunotherapy against tumors. The molecules that are involved in regulating immunological tolerance are then of interest as they may be great targets for positively or negatively manipulating the tolerance process.
Drugs from the Sea: A Marine Sponge-Derived Compound Prevents Type 1 Diabetes
Authors: Van Kaer Luc
Published: March 2005

More than one million Americans have Type 1 diabetes. This disease — also known as autoimmune or juvenile diabetes — strikes children suddenly, makes them dependent on insulin injections for life, and carries the constant threat of devastating complications. While it can and does strike adults, nearly half of all new cases are diagnosed in children. A child is diagnosed with Type 1 diabetes every hour. Type 1 diabetes is caused by the inability of a person’s pancreas to produce sufficient amounts of insulin to control their blood sugar levels and sustain life. While insulin injections allow affected individuals to control their blood sugar and stay alive, it is not a cure nor does it prevent the devastating complications of this disease, which include kidney failure, blindness, amputations, heart attack, and stroke. In Type 1 diabetes, the body’s own immune system goes awry, attacking and destroying insulin-producing cells in the pancreas.
Suppression of Tumor Angiogenesis by Nonsteroidal Anti-Inflammatory Drugs: A New Function for Old Drugs
Authors: Raegg Curzio , Dormond Olivier
Published: March 2005

There is solid epidemiological evidence demonstrating that the regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of developing colorectal cancer, and to a lesser extent gastric and esophageal cancers[1]. Importantly, NSAIDs suppress colon polyp formation and progression in patients diagnosed with familial adenomatous polyposis coli (APC)[2]. In many animal studies, NSAIDs have been shown to prevent tumor formation and slow tumor progression, thus confirming and extending the clinical observations[3,4,5]. Recent findings have demonstrated that NSAIDs inhibit angiogenesis, suggesting that the tumor suppressive activity of these drugs may be due, at least in part, to their ability to inhibit tumor angiogenesis[6]. The study of the mechanism by which NSAIDs suppress tumor angiogenesis, is matter of intense research.
New CGRP Antagonists
Authors: Doods H. N. , Schindler M.
Published: March 2005

The presentation will focus on BIBN 4096 BS, since this compound is still the only potent calcitonin gene-related peptide (CGRP)-antagonist described so far[1].
The Role of CGRPin Nociception?
Authors: Hill R. G.
Published: March 2005

The failure of NK1 receptor antagonists to show analgesic activity in clinical trials in spite of abundant preclinical evidence for a role of this neuropeptide in nociception, makes it somewhat dangerous to speculate on the nociceptive role of other neuropeptides, especially with respect to therapeutic utility of receptor antagonists! However, CGRP is the primary afferent peptide with the strongest evidence of a role in pain perception. It is found in a greater proportion of sensory neurones than other peptides and is a constituent of A[delta ] as well as C-fibres. Inflammation of peripheral tissues upregulates production of CGRP in sensory ganglia, coincident with the development of hyperalgesia, and CGRP knockout mice have attenuated hyperalgesic responses. CGRP is released into the dorsal horn of the spinal cord (DHSC) by noxious peripheral stimuli and excites nociceptive DHSC neurones on local application. The peptide antagonist CGRP8-37 blocks the response to exogenous CGRP and can reduce the response of DHSC neurones to noxious peripheral stimuli. CGRP8-37 has also been shown to have behavioural antinociceptive properties when given intrathecally. Conversely, injection of CGRP itself to the PAG or n. accumbens has been reported to have antinociceptive effects that are reversed by CGRP8-37. With the advent of potent non-peptide antagonists such as BIBN4096BS we should soon be able to determine whether systemic blockade of all CGRP receptors produces antinociception without limiting side effects.
Cgrp Characterization And Classification
Authors: Marshall Ian
Published: March 2005

The peptide CGRP is thought to be an agonist at a number of receptors including its own as well as those for adrenomedullin and amylin. CGRP is thought to act through its own receptors if it is antagonized by the truncated peptide CGRP8-37 although this assumes the specificity of the antagonist.
Signalling by CGRP and Adrenomedullin in the Cerebellum and Other Systems
Authors: Poyner David , Cater Heather , Hartell Nick , Conner Alex , Hay Debbie , Howitt Steve , Smith Dave
Published: March 2005

The best characterised signalling pathway activated by both CGRP and adrenomedullin is stimulation of adenylate cyclase via Gs. However, it is clear that in some circumstances the peptides can activate other signal transduction pathways, e.g., increases in intracellular calcium. Many of these signalling pathways can be observed in cultured cells but it is important also to examine isolated tissues to discover the full repertoire of transduction events. In the rat cerebellum there are receptors that respond to both CGRP and adrenomedullin. These seem to be located postsynaptically on Parallel Fibre nerve terminals and modulate transmission to Purkinje cells. Adrenomedullin acts via cAMP, apparently to augment neurotransmitter release. By contrast, CGRP decreases transmitter release, via a non-cAMP mediated pathway. We are currently examining the role of NO and tyrosine kinases in the responses to these peptides.
The Role of Cgrp-Receptor Component Protein (Rcp) in Cgrp-Mediated Signal Transduction
Authors: Prado M. A. , Evans-Bain B. , Santi S. L. , Dickerson I. M.
Published: March 2005

The calcitonin gene-related peptide (CGRP)-receptor component protein (RCP) is a 17-kDa intracellular peripheral membrane protein required for signal transduction at CGRP receptors. To determine the role of RCP in CGRP-mediated signal transduction, RCP was depleted from NIH3T3 cells using antisense strategy. Loss of RCP protein correlated with loss of cAMP production by CGRP in the antisense cells. In contrast, loss of RCP had no effect on CGRP-mediated binding; therefore RCP is not acting as a chaperone for the CGRP receptor. Instead, RCP is a novel signal transduction molecule that couples the CGRP receptor to the cellular signal transduction machinery. RCP thus represents a prototype for a new class of signal transduction proteins that are required for regulation of G protein-coupled receptors.
Multiple Receptor Subtypes for the CGRP Super-Family
Authors: Quirion R. , Chabot J.-G. Chabot , Dumont Y.
Published: March 2005

Molecular evidence for the existence of multiple receptors for CGRP has been rather difficult to obtain. Over 10 years after suggesting the existence of at least two classes (CGRP1 and CGRP2) of CGRP receptors on the basis of pharmacological data[1], molecular data on the CGRP2 receptor subtype are still lacking as well as potent and selective antagonists. The situation is somewhat different for the functional CGRP1 subtype which is likely composed of diverse subunits CRLR, RAMP1 and possibly RCP[2]. Moreover, BIBN 4096BS was recently reported as the first nonpeptide highly potent CGRP1 receptor antagonist[3]. However, in situ hybridization and receptor autoradiographic data have clearly shown the existence of major mismatches (e.g., cerebellum) between the discrete localization of CRLR, RAMP1, and specific CGRP binding sites supporting the existence of CGRP receptor subtypes. Functional studies have also provided evidence in that regard (for a recent review: [4]). Accordingly, additional studies aiming at cloning additional CGRP receptors are certainly warranted. Similarly, recent evidence from various laboratories including ours suggests the existence of more than one class (CRLR and RAMP2) of adrenomedullin receptors at least in the rat brain. In contrast, most evidence suggests the existence of a single class of amylin receptors. In brief, it appears that multiple receptors or receptor complexes do exist for CGRP and related peptides but their composition is apparently unique among the GPCR super-family and additional data are needed to fully establish the molecular organization of each subtype. Supported by CIHR of Canada.
Study of Cgrp-Receptors in Human Isolated Middle Meningeal Arteries Using Bibn4096Bs, Compound 1, and HαCgrp(8-37)
Authors: Razzaque Z. , Shaw D. , Bock M. , Maskell L. , Pickard J. , Sirinathsinghji D. , Longmore J.
Published: March 2005

Calcitonin, CGRP, adrenomedullin, and amylin require both CRLR (calcitonin-gene receptor like receptor) and receptor activity modifying proteins (RAMP1, RAMP2, and RAMP3) in different combinations for expression of selective, functional receptors[1]. We investigated whether the antagonists BIBN4096BS[2], Compound 1 (WO98/11128, [3]), and CGRP(8-37) are functionally selective for CGRP receptors in human middle meningeal arteries (HMMA).
Cgrp Uptake into Perivascular Capsaicin-Sensitive Nerve Terminals
Authors: Sams-Nielsen A. , Orskov C. , Jansen-Olesen I.
Published: March 2005

Specific mechanisms, providing reuptake of cathecholamine and amino acid neurotransmitters (e.g., serotonin and glutamate) into cells of the central nervous system are well known, whereas neuronal uptake of neuropeptides have not previously been reported.
Calcitonin/Amylin Receptors and Ramps
Authors: Sexton Patrick M.
Published: March 2005

Our understanding of G protein-coupled receptor function has recently expanded to encompass novel protein interactions that underlie both cell surface receptor expression and the exhibited phenotype. The most notable examples are those involving receptor activity modifying proteins (RAMPs). RAMP association with the calcitonin receptor-like receptor (CRLR) traffics this receptor to the cell surface, where individual RAMPs dictate the expression of unique phenotypes.
Structure of Influenza A Virus Promoter and its Implications for Viral RNA Synthesis
Authors: Bae Sung-Hun , Choi Byong-Seok
Published: March 2005

Since the worst worldwide pandemic ever recorded — the 1918 Spanish influenza outbreak that killed more than 20 million people — we have achieved significant advances in understanding the influenza virus. However, the fear of such a pandemic remains strong. For example, in 1997, when a lethal influenza variant afflicted eight people in Hong Kong, contributing to the death of six, officials feared the next wave had begun. They managed to solve the problem quickly, however, by destroying all of the poultry in Hong Kong[1].
Functional Evaluations in the Monitoring of the River Ecosystem Processes: The Adige River as a Case Stu
Authors: Braioni M.G. , Salmoiraghi G. , Bracco F. , Villani M. , Braioni A. , Girelli L.
Published: March 2005

A model of analysis and environmental evaluation was applied to 11 stretches of the Adige River, where an innovative procedure was carried out to interpret ecological results. Within each stretch, the most suitable methods were used to assess the quality and processes of flood plains, banks, water column, bed, and interstitial environment. Indices were applied to evaluate the wild state and ecological quality of the banks (wild state index, buffer strip index) and the landscape quality of wide areas of the fluvial corridor (environmental landscape index). The biotic components (i.e., macrozoobenthos, phytoplankton and zooplankton, interstitial hyporheic fauna, vegetation in the riparian areas) were analysed by both quantitative and functional methods (as productivity, litter – processing and colonisation). The results achieved were then translated into five classes of functional evaluation. These qualitative assessments have thus preserved a high level of precision and sensitivity in quantifying both the quality of the environmental conditions and the integrity of the ecosystem processes. Read together with urban planning data, they indicate what actions are needed to restore and rehabilitate the Adige River corridor.
Optimisation of the Monitoring Strategy of Macroinvertebrate Communities in the River Dender, in Relation to the EU Water Framework Directive
Authors: D’heygere Tom P. , Goethals Peter L.M. , De Pauw Niels
Published: March 2005

The Dender basin in Flanders (Belgium) was used as a case study to implement the European Union (EU) Water Framework Directive. During the last 5 years, ample research on pollution loads and ecological water quality has been done on the Dender River. In addition to biological sampling of macroinvertebrates and fish, automated measurement stations were also used to investigate the spatial-temporal variability of the physical-chemical water quality. This research revealed that the pollution of the Dender River is highly variable. The high nutrient loads result in severe algae blooms during summer, leading to very complex diurnal processes. In this paper, the monitoring strategy for the assessment of the biological water quality in the Dender basin has been reviewed in relation to the EU Water Framework Directive. For this, seasonal macroinvertebrate data were collected and assessed. General trends and hidden structures in these data were analysed by means of classification trees, using different inputs (seasons, river types, and subbasins). Validation of the results was obtained by applying statistical methods. Analysis about the presence and abundance of the macroinvertebrates revealed that there is a distinct difference between the biological water quality in the Dender stem river and its tributaries. There are also seasonal differences between the macroinvertebrate communities when the Dender and its tributaries are examined separately. An optimised monitoring strategy is proposed based on these results and the EU Water Framework Directive. This includes two monitoring campaigns in summer and winter every 3 years. Furthermore, a cyclic monitoring scheme was developed to minimise sampling efforts.
Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers
Authors: Mazzali Cristina , Angelino Elisabetta , Gerosa Giacomo , Ballarin-Denti Antonio
Published: March 2005

Passive samplers (diffusion tubes with organic reagent, produced by Passam of Switzerland) were used in a sampling campaign for the detection of weekly mean ozone concentrations in 15 sites over a domain of 80 x 40 km on the southern side of the European Alps from May to August 1998. The area is characterized by vast natural terrain of complex topography, with conifer and broadleaf forests. It is difficult to access and monitor air quality there with continuous analysers. By applying geostatistical techniques (ordinary kriging), and correcting the interpolated ozone concentrations according to the altitude of each single grid cell (2 x 2 km), maps of weekly ozone concentrations were produced. The weekly ozone data were used to assess daily and hourly data by means of an iterative procedure based on a functional dependence of ozone concentrations both on altitude and on the time of day. This allowed the estimation of values with an exposure index such as AOT40 (accumulated exposure over the threshold of 40 ppb) in all 800 cells of the domain. This also allowed the mapping of risk assessment related to the effects of ozone on the regional forest vegetation. Results obtained show values that exceed the exposure standards adopted in the Kuopio protocol (1996). Excess exposure values also match values calculated over a wider territorial domain by using hourly data on ozone concentration derived from continuous automatic analysers.
Downstream Effects of a Hydroelectric Reservoir on Aquatic Plant Assemblages
Authors: Bernez Ivan , Haury Jacques , Ferreira Maria Teresa
Published: March 2005

Macrophytes were studied downstream of the Rophémel hydroelectric dam on the River Rance (Côtes d’Armor Department, western France) to assess the effects of hydroelectric functioning on river macrophyte communities. We studied ten representative sections of the hydro-peaking channel on five occasions in 1995 and 1996, on a 15-km stretch of river. Floristic surveys were carried out on sections 50 m in length, and genera of macroalgae, species of bryophyta, hydrophytes, and emergent rhizophytes were identified. For the aquatic bryophytes and spermatophytes section of our study, we compared our results with 19thcentury floristic surveys, before the dam was built. During the vegetative growth period, the hydro-peaking frequency was low. The plant richness was highest near the dam. The macrophyte communities were highly modified according to the distance to the dam. The frequency and magnitude of hydro-peaking was related to the aquatic macrophyte richness in an Intermediate Disturbance Hypothesis position. However, the results of the eco-historical comparison with 19thcentury floristic surveys point to the original nature of the flora found at the site. Some floral patterns, seen during both periods and at an interval of 133 years, were indicative of the ubiquity of the aquatic flora and of the plants’ adaptability. This demonstrates the importance of taking river basin history into account in such biological surveys.
Maryland Power Plant Cooling-Water Intake Regulations and their Application in Evaluation of Adverse Environmental Impact
Authors: McLean Richard , Richkus William A. , Schreiner Stephen P. , Fluke David
Published: March 2005

Maryland’s cooling-water intake and discharge regulations, the Code of Maryland Regulations (COMAR) 26.08.03, stem from Sections 316(a) and (b) of the Clean Water Act (CWA). COMAR 26.08.03.05 and litigative and administrative rulings stipulate that the location, design, construction, and capability of cooling-water intake structures must reflect the best technology available (BTA) for minimizing adverse environmental impacts (AEIs), providing that the costs of implementing the BTA are not wholly disproportionate to the expected environmental benefits. Maryland law exempts facilities that withdraw less than 10 million gallons/day (MGD) and less than 20% of stream or net flow by the intake. If not exempt, BTA must be installed if the cost of doing so is less than five times the value of fish impinged annually. Through site-specific studies and the use of a Spawning and Nursery Area of Consequence (SNAC) model applied to Representative Important Species, several power plants were evaluated to determine if they have had an adverse effect on spawning and nursery areas of consequence. Examples of application of the Maryland law to a number of power plants in the state are presented, together with the outcome of their evaluation.