bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogenolysis-Isomerization-Reduction of Propargyl Acetate, and Regio- and Stereoselective Hydrogenation of Dienyl Ester for the Synthesis of 1β-Methylcarbapenem Precursor
Authors: Fujisawa Tamotsu , Hayakawa Ryuuichirou , Shimizu Makoto
Published: March 2006

A straightforward synthetic route of lβ-methylcarbapenem precursor is established by hydrogenolysis-isomerization-reduction process of propargyl acetate or by regio- and stereoselective hydrogenation process of dienyl ester with complete stereoselectivity.
Reactivities of Neutral and Cationic Organopalladium Complexes
Authors: Kayaki Yoshihito , Shimizu Isao , Yamamoto Akio
Published: March 2006

Novel, neutral and cationic monoorganopalladium complexes containing the methyl ligand as well as ethyl ligands having polar substituents have been prepared and their reactivities toward CO insertions have been compared. The results indicate that ready availability of CO coordination site in the complexes is the most important factor in determining the reactivities of the monoorganopalladium complexes toward CO insertion.
Generation of a Selenoaldehyde, a Selenoketone, and Telluroaldehydes by [3,3] Sigmatropic Rearrangement of Allyl Alkenyl Selenides and Tellurides
Authors: Shimada Kazuaki , Oikawa Seiji , Nakamura Hidenori , Takikawa Yuji
Published: March 2006

A selenoaldehyde, a selenoketone, and telluroaldehydes were generated by [3,3] sigmatropic rearrangement of allyl alkenyl selenides and tellurides, respectively, and were trapped with 2,3-dimethyl-1,3-butadiene to give the corresponding [4+2] cycloadducts.
A Highly Convenient, One-Pot Synthesis of 3-Bromo-1,5- and -1,7-Azulenequinones by Polybromination of Azulene
Authors: Nozoe Tetsuo , Wakabayashi Hidetsugu , Shindo Kimio , Kurihara Teruo , Ishikawa Sumio , Kageyama (the late) Masanori
Published: March 2006

A very convenient, one-pot synthesis (in ca. 80% yield) of 3-Bromo-1,5- and -1,7-azulenequinones which can be used as synthones has been developed by polybromination of azulenes. Zink dust reduction and reductive acetylation of these azulenequinones were studied, and possible pathways for the present synthesis are briefly discussed.
Activity of Alkaline and Alkaline-Earth Carbonates as Heterogeneous Catalysts for the Knoevenagel Condensation between Benzaldehyde and Malononitrile
Authors: Aramendia María Angeles , Borau Victoriano , Jimenez César , Marinas José María , Romero Francisco José
Published: March 2006

This paper reports the results obtained in the Knoevenagel condensation between benzaldehyde and malononitrile using various alkaline and alkaline-earth carbonates as catalysts. Within each carbonate series, the catalyst basicity increases with increasing ionic radius of the metal. Also, the catalytic activity increases with increase in the solid basicity.
Isolation and Characterization of Two Distinct Azurins from Alcaligenes xylosoxidans subsp. xylosoxidans NCIB11015 or GIFU1051
Authors: Yamaguchi Kazuya , Deligeer  , Nakamura Nobuhumi , Shidara Sohsuke , Iwasaki Hidekazu , Suzuki Shinnichiro
Published: March 2006

Two distinct azurins isolated from Alcaligenes xylosoxidans subsp. xylosoxidans NCIB11015 or GIFU1051 have been characterized by electronic absorption, circular dichroism (CD), and electronic paramagnetic resonance (EPR) spectroscopies. On the basis of CD spectra, two azurins from bacteria are clearly distinguishable.
Presence of Electrostatic Potential Wells in the Ionic Polymer Network
Authors: Gong Jianping , Osada Yoshihito
Published: March 2006

The electrostatic potential distribution of cross-linked polyelectrolyte gels has been numerically calculated on the base of Poisson-Boltzmann equation using a three dimensional network geometry. The simulational result revealed that besides potential energy valleys around the polymer chains, there should exist deep electrostatic potential energy wells at every cross-linking point.
Oxidation of Tetraarylselenophenes and Benzo[b]selenophene with m-Chloroperbenzoic Acid
Authors: Nakayama Juzo , Matsui Tomoki , Sato Noriko
Published: March 2006

Oxidation of tetraarylselenophenes with m-chloroperbenzoic acid produces cis-1,2-diaroyl-1,2-diarylethylenes and SeO2 as the principal product, while the oxidation of benzo[b]selenophene affords benzo[b]selenophene 1-oxide.
The Development of a Program Visualizing Results of Vibrational Analysis Calculation Using ab initio Molecular Orbital Method
Authors: Tsutsui Yuko , Wasada Hiroaki
Published: March 2006

We developed a computer program MOLCAT to visualize results of vibrational analysis calculation. This program can treat Z-matrix used in ab initio molecular orbital calculation, and shows the vibrational mode as arrows with the molecular structure. We applied this program to show transition vectors of the intramolecular inversion of ammonia and the water exchange reaction of hexaaquacalcium(II). We are preparing to distribute MOLCAT as a free software.
Synthesis and Structure of a New Tripodal Polypyridine Copper(II) Complex That Enables to Recognize a Small Molecule
Authors: Harata Manabu , Jitsukawa Koichiro , Masuda Hideki , Einaga Hisahiko
Published: March 2006

With a view to constructing an artificial metalloenzyme model complex which can recognize and capture a small molecule, a new tripodal ligand, tris(6-pivaloylamino-2-pyridylmethyl)amine, and its mononuclear copper(II) complex has been synthesized, and they were characterized by 1H-NMR and positive-ion FAB mass spectra, cyclic voltammetry and X-ray structure analysis.
Preparation and Structure of 2,3-Dichloro-1,4-bis(2,4,6-tri-t-butylphenyl)-1,4-diphospha-1,3-butadiene
Authors: Ito Shigekazu , Toyota Kozo , Yoshifuji Masaaki
Published: March 2006

A sterically protected 1,4-diphospha-1,3-butadiene was prepared from the copper-mediated coupling reaction of 2,2-dichloro-1-(2,4,6-tri-t-butylphenyl)-1-phosphaethene. The X-ray crystallographic analysis shows that the molecule has a center of symmetry and that each of the bulky phenyl groups tilts almost perpendicularly to the diphosphabutadiene system serving as a good protecting group.
Self-Assembly of Cyclic Ruthenium Porphyrin Tetramer
Authors: Funatsu Kenji , Kimura Akira , Imamura Taira , Sasaki Yoichi
Published: March 2006

A novel cyclic ruthenium porphyrin tetramer was synthesized and characterized by spectral methods.
O2-Transport Albumin: A New Hybrid-Haemoprotein Incorporating Tetraphenylporphinatoiron(II) Derivative
Authors: Komatsu Teruyuki , Ando Katsutoshi , Kawai Noriyuki , Nishide Hiroyuki , Tsuchida Eishun
Published: March 2006

2-[8-{N-(2-methylimidazolyl)}octanoyloxymethyl]-5,10,15,20-tetrakis(α,α,α,α-o-pivalamido)phenylporphinatoiron(II) is incorporated into the human serum albumin, which reversibly forms a stable O2-adduct under physiological conditions (in aqueous medium, pH 7.4, 37 °C) similar to haemoglobin.
Molecular Recognition of Horse Heart Apomyoglobin to Monopropionate Hemin: Thermodynamic Determination of Two Orientational Isomers by 1H NMR Spectra
Authors: Hayashi Takashi , Hitomi Yutaka , Suzuki Akihiro , Takimura Tetsuo , Ogoshi Hisanobu
Published: March 2006

Four synthetic hemins, 1,3,5,8-tetramethyl-2,4-diethyl-6,7-dipropionate hemin (1), 1,2,3,4-tetraethyl-5,6,8-trimethyl-7-propionate hemin (2), 1,3,5,6,8-pentamethyl-2,4-diethyl-7-propionate hemin (3) and 1,3,5,7,8-pentamethyl-2,4-diethyl-6-propionate hemin (4) were prepared and incorporated into apomyoglobin to clarify hydrophilic interaction of the hemin propionate with particular polar amino acid residues. Favorable orientation of hemin in protein is interpreted by thermodynamic study using 1H NMR measurement.
Preparation and Characterization of Di-μ-oxo Dimanganese(IV) Complexes with Bidentate Schiff Bases, N-Alkyl-salicylideneamine
Authors: Torayama Hitoshi , Asada Hideyuki , Fujiwara Manabu , Matsushita Takayuki
Published: March 2006

Novel di-μ-oxo dimanganese(IV) complexes, [MnIV(N-R-sal)2(μ-O)]2, with bidentate Schiff base ligands, N-alkyl-salicylideneamine, N-R-salH (R = n-C3H7 (Pr), n-C4H9 (Bu), n-C6H13 (Hx), n-C8H17 (Oct), n-C12H25 (Dod), or n-C18H37 (Octd)), have been prepared and characterized by spectroscopies, magnetic susceptibilities, thermal analysis and X-ray crystallography.
Ruthenium-Catalyzed Addition of Aromatic Esters at the ortho C–H Bonds to Olefins
Authors: Sonoda Motohiro , Kakiuchi Fumitoshi , Kamatani Asayuki , Chatani Naoto , Murai Shinji
Published: March 2006

A ruthenium complex, Ru(H)2(CO)(PPh3)3, can catalyze the addition of aromatic and heteroaromatic esters at the ortho carbon-hydrogen bonds to olefinic double bonds. While un-substituted alkyl benzoate did not react, those substituted with CF3 or F underwent smooth catalytic addition. A heteroaromatic ester and a benzo-δ-lactone also reacted.
New Electrochemical Preparation of Reactive Zinc with a Large Surface Area
Authors: Tokuda Masao , Kurono Nobuhito , Mimura Nobuo
Published: March 2006

Reactive zinc was readily prepared by electrolysis of a DMF solution containing 0.1 M Et4NClO4 using a platinum cathode and a zinc anode. Characterization of the zinc metal showed that it was an aggregation of very fine, crystalline zinc particles with a specific surface area of 24 m2/g, which is 100 times larger than that of commercial zinc metals. Preparation of zinc with a much larger surface area of 56 m2/g could be achieved by electrolysis of the solution at a lower current density.
Asymmetric Allylation of Aromatic Aldehydes Using Chiral Allylic Tin Reagents
Authors: Nishida Minoru , Tozawa Takashi , Yamada Koji , Mukaiyama Teruaki
Published: March 2006

Chiral allylating reagents, readily generated in situ from 2λ2-1,3,2-benzodioxastannole [SnII(O2C6H4)], allyl halides, chiral dialkyl tartrates and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) smoothly react with aromatic aldehydes at −78 °C in the presence of a catalytic amount of copper salts to afford the corresponding homoallylic alcohols in high yields with high enantioselectivities.
The Effect of Pressure on the Surface Structure of MgO/BaCO3 Catalyst for Oxidative Coupling of Methane
Authors: Liu Yu , Yu Changchun , Liu Xuxia , Zhang Bing , Shen Shikong
Published: March 2006

The effect of pressure on oxidative coupling of methane (OCM) over MgO/BaCO3 catalyst was studied at the range of 0.1∼1.1 MPa at 1053 K. Deactivation of the MgO/BaCO3 catalyst at elevated pressure was attributed to the migration of BaCO3 from bulk to the surface of the catalyst.
A New Ring Contraction Rearrangement of 2,5- and 3,6-Di-tert-butyl-3H-azepines to Pyridine Derivatives
Authors: Satake Kyosuke , Takaoka Koichi , Hashimoto Michiaki , Okamoto Hideki , Kimura Masaru , Morosawa Shiro
Published: March 2006

A new ring contraction reaction giving pyridine derivatives from 3,6- and 2,5-di-tert-butyl-3H-azepines was observed by a successive treatment with bromine and aqueous K2CO3. A plausible mechanism via azatropilium cation for the rearrangement was discussed based on the product’s distribution from respective 3H-azepines.
Benzoin Oxidation at Extreme Temperature by Bis (1,2-benzenedithiolato)dioxotungstate(VI) Complex: A Model Study for Hyperthermostable Tungsten Oxidoreductases
Authors: Oku Hiroyuki , Ueyama Norikazu , Nakamura Akira
Published: March 2006

The oxidation of benzoin by (NEt4)2[MVIO2(S2C6H4)2] (M = W (1) and Mo (2)) (S2C6H4 = 1,2-benzenedithiolate) was studied to clarify the role of tungsten ions in hyperthermostable enzymes. The reaction was analyzed by saturation kinetics, primary isotope effects of kH/kD, and the high temperture reaction at 100 °C. The rate constants were also compared with those of the selenolato analogs.
Synthesis and Characterization of [RuIIICl2(TPA)]+ (TPA = Tris(2-pyridylmethyl)amine) and Its Reactivity toward Alkane Functionalization
Authors: Kojima Takahiko
Published: March 2006

A new ruthenium(III) monomer complex having a tripodal ligand TPA was synthesized and characterized by X-ray crystallography and cyclic voltammetry. The title compound was revealed to catalyze alkane functionalization with m-chloroperbenzoic acid.
N-Oxidation of π-Conjugated Poly(heterocycle)s Containing Nitrogen and Electrically Conducting Properties of the N-Oxidized Products
Authors: Yamamoto Takakazu , Saito Nobuo
Published: March 2006

Oxidation of poly(quinoline-2,6-diyl) and its analogue with H2O2 gives N-oxidized products, which show dc conductivity of 2.3–3.2 × 10−6 S cm−1 without doping.
Stereocontrolled Elongation of a Functionalized Isoprene Unit on the E or Z Terminal Methyl of Terpenoids via N-Ylide Rearrangement of the Common Ammonium Salts
Authors: Honda Kiyoshi , Tabuchi Masayuki , Inoue Seiichi
Published: March 2006

Stereocontrolled elongation of a functionalized isoprene unit on the E or Z terminal methyl of terpenoids was achieved by the N-ylide rearrangement of the common ammonium salts under the selected reaction conditions. One of rearrangement products, all-(E)-sesquiterpene carboxylate was converted into β-sinensal, a component of the essential oil of Chinese orange. General aspects of these transformations were described.
Direct Observation of Hydrogen-Deuterium Exchange Reaction in Cobaloxime Crystal by Neutron Diffraction
Authors: Ohgo Yoshiki , Ohashi Yuji , Klooster Wim T , Koetzle Thomas F
Published: March 2006

After a crystal of [(R)-1-cyanoethyl-dα][(S)-1-phenylethylamine]bis(dimethylglyoximato)cobalt(III) was exposed to a xenon lamp for two weeks, its structure was analyzed by neutron diffraction. The deuterium atom was exchanged partially with one of the three methyl hydrogenes of the cyanoethyl group. The exchanged one is located closest to the deuterium atom.
Incorporation and Direct Electron Transfer of Chlorella Ferredoxin in the Bilayer Films of Cationic Lipids on Electrodes
Authors: Tominaga Masato , Yanagimoto Junko , Nassar Alaa-Eldin F , Rusling James F , Nakashima Naotoshi
Published: March 2006

Chlorella ferredoxin in solution was found to be incorporated into the cast films of ammonium lipids on basal plane pyrolytic graphite (BPG) electrodes via ion exchange between the lipid counter anion and negatively charged ferredoxin and was embedded in them without denaturation in a way to undergo direct electron transfer reactions with the electrode.
A Catalytic Amount of Titanium Tetrahalide as Promoter for the Addition Reaction of Silyl Ketene Acetals to Imines
Authors: Shimizu Makoto , Kume Kouji , Fujisawa Tamotsu
Published: March 2006

In the presence of a catalytic amount of TiBr4 or TiI4, the reaction of silyl ketene acetals with imines smoothly proceeds to give the corresponding β-amino esters in high yield with high anti-selectivity.
Unique Temperature Dependence of NMR and UV-visible Spectra of Poly(3-hexylthiophene-2,5-diyl) and Its Related Compounds
Authors: Yamamoto Takakazu
Published: March 2006

Lowering temperature of solutions of poly(3-hexylthiophene-2,5-diyl) P3HxTh below −10 – −20 °C leads to decrease in signal intensity of aromatic-H and α-CH2 in 1H-NMR spectrum. A shift of the π-π* absorption band to a longer wavelength by 26–60 nm is also observed. These results are accounted for by aggregation of P3HxTh through intermolecular interaction of the π-conjugated system.
Ruthenium Complexes Containing an Azobipyridine Ligand as Redox-Responsive Molecular Switches
Authors: Otsuki Joe , Sato Kinu , Tsujino Masayuki , Okuda Naotoshi , Araki Koji , Seno Manabu
Published: March 2006

Mononuclear and dinuclear ruthenium complexes containing an azobipyridine ligand serve as reversible redox-responsive molecular switches modulating electron localization in the excited-state that can be read out through the emission intensity.
Synthesis and Characterization of Novel Phosphido-Bridged Bimetallic Complexes of Molybdenum and Tungsten
Authors: Minato Makoto , Nakamura Takashi , Ito Takashi , Koizumi Takeaki , Osakada Kohtaro
Published: March 2006

The phosphido-bridged molybdenum and tungsten complexes [Cp2M(H)(μ-PPh2)M′(H)Cp2]+(OTs)− (M, M′ = Mo, W) were prepared and characterized. The X-ray crystallography for the complex (M = M′ = Mo) indicated that it has a novel symmetrical structure with regard to two metal centers.
Photodimerizations of 3-Methoxy-1,5-azulenequinone via Consecutive Pericyclic Reactions
Authors: Mori Akira , Kawakami Hiroko , Takeshita Hitoshi , Nozoe Tetsuo
Published: March 2006

3-Methoxy-1,5-azulenequinone gave dimers when irradiated with a high-pressure mercury lamp. The product distribution was dependent on the polarity of the solvent. In a polar solvent, a head-to-head dimer was predominant whereas a head-to-tail dimer was mainly formed in a nonpolar solvent.
Boundary‐layer friction in midlatitude cyclones
Authors: Adamson D. S. , Belcher S. E. , Hoskins B. J. , Plant R. S.
Published: February 2006

Results from an idealized three‐dimensional baroclinic life‐cycle model are interpreted in a potential vorticity (PV) framework to identify the physical mechanisms by which frictional processes acting in the atmospheric boundary layer modify and reduce the baroclinic development of a midlatitude storm. Considering a life cycle where the only non‐conservative process acting is boundary‐layer friction, the rate of change of depth‐averaged PV within the boundary layer is governed by frictional generation of PV and the flux of PV into the free troposphere. Frictional generation of PV has two contributions: Ekman generation, which is directly analogous to the well‐known Ekman‐pumping mechanism for barotropic vortices, and baroclinic generation, which depends on the turning of the wind in the boundary layer and low‐level horizontal temperature gradients. It is usually assumed, at least implicitly, that an Ekman process of negative PV generation is the mechanism whereby friction reduces the strength and growth rates of baroclinic systems. Although there is evidence for this mechanism, it is shown that baroclinic generation of PV dominates, producing positive PV anomalies downstream of the low centre, close to developing warm and cold fronts. These PV anomalies are advected by the large‐scale warm conveyor belt flow upwards and polewards, fluxed into the troposphere near the warm front, and then advected westwards relative to the system. The result is a thin band of positive PV in the lower troposphere above the surface low centre. This PV is shown to be associated with a positive static stability anomaly, which Rossby edge wave theory suggests reduces the strength of the coupling between the upper‐ and lower‐level PV anomalies, thereby reducing the rate of baroclinic development. This mechanism, which is a result of the baroclinic dynamics in the frontal regions, is in marked contrast with simple barotropic spin‐down ideas. Finally we note the implications of these frictionally generated PV anomalies for cyclone forecasting. Copyright © 2006 Crown copyright
Equatorial waves in the lower stratosphere. I: A novel detection method
Authors: Tindall J. C. , Thuburn J. , Highwood E. J.
Published: February 2006

Wavenumber–frequency spectral analysis and linear wave theory are combined in a novel method to quantitatively estimate equatorial wave activity in the tropical lower stratosphere. The method requires temperature and velocity observations that are regularly spaced in latitude, longitude and time; it is therefore applied to the ECMWF 15‐year re‐analysis dataset (ERA‐15). Signals consistent with idealized Kelvin and Rossby‐gravity waves are found at wavenumbers and frequencies in agreement with previous studies. When averaged over 1981–93, the Kelvin wave explains approximately 1 K2 of temperature variance on the equator at 100 hPa, while the Rossby‐gravity wave explains approximately 1 m2s−2 of meridional wind variance. Some inertio‐gravity wave and equatorial Rossby wave signals are also found; however the resolution of ERA‐15 is not sufficient for the method to provide an accurate climatology of waves with high meridional structure. Copyright © 2006 Royal Meteorological Society
Equatorial waves in the lower stratosphere. II: Annual and interannual variability
Authors: Tindall J. C. , Thuburn J. , Highwood E. J.
Published: February 2006

The annual and interannual variability of idealized, linear, equatorial waves in the lower stratosphere is investigated using the temperature and velocity fields from the ECMWF 15‐year re‐analysis dataset. Peak Kelvin wave activity occurs during solstice seasons at 100 hPa, during December–February at 70 hPa and in the easterly to westerly quasi‐biennial oscillation (QBO) phase transition at 50 hPa. Peak Rossby‐gravity wave activity occurs during equinox seasons at 100 hPa, during June–August/September–November at 70 hPa and in the westerly to easterly QBO phase transition at 50 hPa. Although neglect of wind shear means that the results for inertio‐gravity waves are likely to be less accurate, they are still qualitatively reasonable and an annual cycle is observed in these waves at 100 hPa and 70 hPa. Inertio‐gravity waves with n=1 are correlated with the QBO at 50 hPa, but the eastward inertio‐gravity n=0 wave is not, due to its very fast vertical group velocity in all background winds. The relative importance of different wave types in driving the QBO at 50 hPa is also discussed. The strongest acceleration appears to be provided by the Kelvin wave while the acceleration provided by the Rossby‐gravity wave is negligible. Of the higher‐frequency waves, the westward inertio‐gravity n=1 wave appears able to contribute more to the acceleration of the 50 hPa mean zonal wind than the eastward inertio‐gravity n=1 wave. Copyright © 2006 Royal Meteorological Society
Assimilation of stratospheric ozone from MIPAS into a global general‐circulation model: The September 2002 vortex split
Authors: Geer A. J. , Peubey C. , Bannister R. N. , Brugge R. , Jackson D. R. , Lahoz W. A. , Migliorini S. , O'Neill A. , Swinbank R.
Published: February 2006

Ozone and temperature profiles from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have been assimilated, using three‐dimensional variational assimilation, into a stratosphere‐troposphere version of the Met Office numerical weather‐prediction system. Analyses are made for the month of September 2002, when there was an unprecedented split in the southern hemisphere polar vortex. The analyses are validated against independent ozone observations from sondes, limb‐occultation and total column ozone satellite instruments. Through most of the stratosphere, precision varies from 5 to 15%, and biases are 15% or less of the analysed field. Problems remain in the vortex and below the 60 hPa level, especially at the tropopause where the analyses have too much ozone and poor agreement with independent data. Analysis problems are largely a result of the model rather than the data, giving confidence in the MIPAS ozone retrievals, though there may be a small high bias in MIPAS ozone in the lower stratosphere. Model issues include an excessive Brewer‐Dobson circulation, which results both from known problems with the tracer transport scheme and from the data assimilation of dynamical variables. The extreme conditions of the vortex split reveal large differences between existing linear ozone photochemistry schemes. Despite these issues, the ozone analyses are able to successfully describe the ozone hole split and compare well to other studies of this event. Recommendations are made for the further development of the ozone assimilation system. Copyright © 2006 Royal Meteorological Society. D. R. Jackson and R. Swinbank contributions are Crown copyright
Entropy sources in a dynamical core atmosphere model
Authors: Woollings Tim , Thuburn John
Published: February 2006

Numerical atmosphere models are not generally constructed to ensure accurate treatment of entropy, but little is known about the significance of the resulting errors. This paper examines the entropy changes during a baroclinic wave simulation in a typical dynamical core model, specifically a σ‐coordinate spectral model, which includes scale‐selective dissipation terms in the form of a numerical hyperdiffusion. Lagrangian entropy conservation is found to be badly represented, with numerical transport errors resulting in cross‐isentrope mass fluxes which are of the same size as those associated with some real diabatic processes. In a global average, the total entropy increases at a rate of just 0.5 mW m−2K−1. This, however, is seen to be the residual of two opposing numerical effects which are several times larger, namely the destruction of entropy by dispersion and Gibbs errors, and its creation by diffusion. The entropy generated by diffusion is shown to be remarkably insensitive to the details of the diffusion scheme. This leads us to hypothesize that the entropy source from diffusion is determined by the rate at which small scales are generated by the deformation field of the large‐scale flow so that, while the diffusion mechanism is clearly unrealistic, the magnitude of the entropy source is, we argue, representative of that generated by physical dissipative processes in the real atmosphere. Even in this simple model it is not possible to quantify precisely the different entropy sources and sinks which combine to give the overall entropy change. However, we can say that if there is a systematic spurious entropy source in this model, then it is small, i.e. of size 0.5 mW m−2K−1 or smaller. Copyright © 2006 Royal Meteorological Society
Estimating vertical velocity and radial flow from Doppler radar observations of tropical cyclones
Authors: Lee J. L. , Lee W. C. , Macdonald A. E.
Published: February 2006

The mesoscale vorticity method (MVM) is used in conjunction with the ground‐based velocity track display (GBVTD) to derive the inner‐core vertical velocity from Doppler radar observations of tropical cyclone (TC) Danny (1997). MVM derives the vertical velocity from vorticity variations in space and in time based on the mesoscale vorticity equation. The use of MVM and GBVTD allows us to derive good correlations among the eye‐wall maximum wind, bow‐shaped updraught and echo east of the eye‐wall in Danny. Furthermore, we demonstrate the dynamically consistent radial flow can be derived from the vertical velocity obtained from MVM using the wind decomposition technique that solves the Poisson equations over a limited‐area domain. With the wind decomposition, we combine the rotational wind which is obtained from Doppler radar wind observations and the divergent wind which is inferred dynamically from the rotational wind to form the balanced horizontal wind in TC inner cores, where rotational wind dominates the divergent wind. In this study, we show a realistic horizontal and vertical structure of the vertical velocity and the induced radial flow in Danny's inner core. In the horizontal, the main eye‐wall updraught draws in significant surrounding air, converging at the strongest echo where the maximum updraught is located. In the vertical, the main updraught tilts vertically outwards, corresponding very well with the outward‐tilting eye‐wall. The maximum updraught is located at the inner edge of the eye‐wall clouds, while downward motions are found at the outer edge. This study demonstrates that the mesoscale vorticity method can use high‐temporal‐resolution data observed by Doppler radars to derive realistic vertical velocity and the radial flow of TCs. The vorticity temporal variations crucial to the accuracy of the vorticity method have to be derived from a high‐temporal‐frequency observing system such as state‐of‐the‐art Doppler radars. Copyright © 2006 Royal Meteorological Society
Limited‐area model error statistics over Western Africa: Comparisons with midlatitude results
Authors: Montmerle. Thibaut , Lafore Jean‐Philippe , Berre Loïk , Fischer Claude
Published: February 2006

In the context of the African Monsoon Multidisciplinary Analyses experiment, a new forecast error covariance matrix has been computed for data assimilation purposes, using the spectral mesoscale limited‐area model ALADIN. The so‐called ‘lagged NMC’ method has been applied using sets of forecast differences performed during the summer overWestern Africa. Multiple linear regressions on these differences have been computed in order to determine statistics and balance features between forecast errors of divergence, vorticity, specific humidity, temperature and surface pressure. The resulting auto‐ and cross‐covariances display very different features from those obtained over Western Europe, and they reflect the uncertainty of forecasting the main meteorological features of the West African Monsoon. While the geostrophic coupling with vorticity is predominant in midlatitudes, over western Africa the main mass/wind couplings instead involve divergence in the low troposphere and below the tropopause. The couplings between e.g. low‐level humidity, temperature and divergence are strengthened over Africa. The vertical correlations are broader for increasing horizontal scales but in a much less pronounced manner than in midlatitudes. The mean vertical correlations for humidity are much more localized in the low troposphere over Africa. Copyright © 2006 Royal Meteorological Society
The impact of urban areas on weather
Authors: Collier C. G.
Published: February 2006

The industrial revolution led to a rapid development of urban areas. This has continued unremittingly over the last 200 years or so. In most urban areas the surface properties are heterogeneous, which has significant implications for energy budgets, water budgets and weather phenomena within the part of the earth's atmosphere that humans live. In this paper I discuss the structure of the planetary boundary layer, confining our analysis to the region above the rooftops (canopy layer) up to around the level where clouds form. It is in this part of the atmosphere that most of the weather impacting our lives occurs, and where the buildings of our cities impact the weather.

In this review, observations of the structure of the urban atmospheric boundary layer are discussed. In particular the use of Doppler lidar provides measurements above the canopy layer. The impact of high‐rise buildings is considered.

Urban morphology impacts energy fluxes and airflow leading to phenomena such as the urban heat island and convective rainfall initiation. I discuss in situ surface‐based remote sensing and satellite measurements of these effects. Measurements have been used with simple and complex numerical models to understand the complexity and balance of the interactions involved. Cities have been found to be sometimes up to 10 degC warmer than the surrounding rural areas, and to cause large increases in rainfall amounts. However, there are situations in which urban aerosol may suppress precipitation.

Although much progress has been made in understanding these impacts, our knowledge remains incomplete. These limitations are identified. As city living becomes even more the norm for large numbers of people, it is imperative that we ensure that urban effects on the weather are included in development plans for the built environment of the future. Copyright © 2006 Royal Meteorological Society
Some numerical properties of approaches to physics–dynamics coupling for NWP
Authors: Dubal Mark , Wood Nigel , Staniforth Andrew
Published: February 2006

At the present time there exist a number of different approaches to the problem of coupling parametrized physical processes to the dynamical core in operational numerical weather‐prediction (NWP) and climate models. Motivated by the various strategies in use, some idealized representative coupling schemes are constructed and subsequently analysed using a methodology in which the physics and dynamics terms are represented in a simplified way. Particular numerical properties of the idealized schemes which are of interest are the ability to capture correct steady‐state solutions and to be second‐order accurate in time. In general, the schemes require specific choices for the time‐differencing of certain coupled processes if correct steady‐state solutions are to be obtained. This has implications for the overall numerical stability of a coupling strategy. An alternative physics–dynamics coupling approach is then described and analysed. A multiple‐sweep predictor–corrector coupling scheme is shown to capture the correct steady‐state solution and to allow for second‐order accuracy, provided that the convective process is coupled explicitly. This approach has a number of advantages over those currently used in operational NWP models. Copyright © 2006 Crown copyright
Intense convective systems in West Africa and their relationship to the African easterly jet
Authors: Mohr Karen I. , Thorncroft Chris D.
Published: February 2006

For May–September 1998, convective systems in West Africa were identified from observations by the Tropical Rainfall Measuring Mission satellite Microwave Imager at 85 GHz. Using re‐analysis data, the 10‐day average position of the African easterly jet (AEJ) was diagnosed from the 700 hPa zonal winds. The distance from each convective system's centroid to the axis of the AEJ was calculated. Each convective system's minimum brightness temperatures were ranked so that intense convective systems were defined as those in the 10th percentile or lower. The weak (>10th percentile) and intense convective systems were represented statistically as two separate populations, the weak by the skewed Gumbel distribution and the intense by the normal distribution. From May to August, the peak in activity of weak convective systems remained south of 10°N but shifted east of 10°E. The peak in activity of the intense convective systems followed the seasonal migration of the AEJ northwards and became increasingly separate from the peak in activity of weak convective systems. The majority of both weak and intense convective systems occurred within 0.50° of high terrain. The high convective available potential energy, high‐shear AEJ environment in the vicinity of high terrain appeared to have the greatest probability of generating intense convective systems in the study area. Copyright © 2006 Royal Meteorological Society
Radiative and turbulent heating rates in the clear‐air boundary layer
Authors: Savijärvi Hannu
Published: February 2006

The diurnal evolution of a clear‐sky midlatitude summertime boundary layer (BL) was studied using a column model over smooth and homogeneous land, subject to weak, moderate, and strong winds. The high‐resolution BL model (lowest point at 30 cm) was equipped with an adequate turbulence scheme and a narrow‐band long‐wave (LW) radiation scheme, the latter validated using data from the International Comparison of Radiation Codes in Climate Models (ICRCCM).

In off‐line ICRCCM experiments, ground emissivity ε < 1 led to extra LW cooling of air near the surface compared to ε = 1. However, much stronger LW cooling at heights of 1–3 m, and warming below 1 m, was obtained by setting the ground colder than air at screen height, a typical condition during clear nights. Conversely, a warm surface anomaly typical of sunny days leads to strong LW warming at 1–3 m, with LW cooling just above the ground. These ground temperature anomalies dominated the LW heating/cooling patterns at heights of up to 3–4 m, perhaps explaining controversies in the observed LW flux divergences close to the ground.

Interactive model results indicate that the middle part of a windy clear‐air nocturnal BL (NBL) is dominated by turbulent cooling, while the upper and lower NBL is dominated by LW cooling. Below about 1 m, a fourth layer is formed with LW warming and turbulent cooling, in agreement with the off‐line experiments. When the surface winds fall below about 1–1.5 m s−1 LW cooling dominates in the whole NBL, except very near the surface. In these light wind conditions the Monin–Obukhov theory should be revised to include radiative effects.

In clear‐air daytime conditions strong convective BL heating dominates over weak LW cooling except at 1–3 m heights where the cooler air absorbs the thermal emission of the hot ground. The subsequent LW warming of the superadiabatic surface layer appears to be strong enough to induce local turbulent cooling (despite the hot surface) in an ‘hour glass’ pattern independently of wind speed, such that the total diabatic heating rate remains nearly constant with height. Copyright © 2006 Royal Meteorological Society
Simulation of the observed evening transition and nocturnal boundary layers: Single‐column modelling
Authors: Edwards J. M. , Beare R. J. , Lapworth A. J.
Published: February 2006

Observations of the evolution of the atmospheric boundary layer through the evening transition and the early hours of the night are presented. Parallel simulations in a single‐column model are conducted to assess the performance of the parametrization scheme and the sensitivity to vertical resolution. The study is set within the context of a numerical weather‐prediction system and the importance of the synoptic situation is emphasized.

Comparisons are also drawn with an accompanying study describing large‐eddy simulations based on these same data. These show that, when the single‐column model is run with sharp‐tailed stability functions, turbulent diffusion is systematically underestimated in and just above the surface layer, while it is overestimated at greater heights; the parametrized profile of diffusivity is therefore too uniform, causing the temperature profile in the single‐column model to exhibit negative curvature, rather than the positive curvature seen in the observations and in the large‐eddy simulations. Copyright © 2006 Crown copyright
Simulation of the observed evening transition and nocturnal boundary layers: Large‐eddy simulation
Authors: Beare R. J. , Edwards J. M. , Lapworth A. J.
Published: February 2006

Large‐eddy simulations are performed of two observed cases of evening transition boundary layers over land. Although generally similar to the observations, the simulations have a poor match to the ageostrophic wind above the boundary layer and overestimate the nocturnal 4 m wind speed. For one case, the nocturnal phase is also simulated using a close match to observations in the early evening, reproducing well the early morning boundary layer and jet. This is achieved with a moderate resolution (5 m) and also demonstrates the importance of a good initial wind state. In a numerical weather‐prediction context, these findings motivate improved wind profile observations around transition, and a better representation of the ageostrophic wind by the boundary‐layer parametrization. Copyright © 2006 Crown copyright
Unusual γ heavy chain disease protein in a patient with splenic marginal-zone lymphoma
Authors: Morita Keiko , Kawamoto Hiromi , Takada Honami , Nakamura Shinobu , Ishii Kazuyoshi , Okamoto Yasuyuki
Published: February 2006

We conducted an electrophoretic analysis of monoclonal γ-globulin found in the serum of a patient with splenic marginal-zone lymphoma. This monoclonal protein showed electrophoretic mobility to the γ region and reacted with antii-mmunoglobulin (IgG) antiserum but not with anti- κ or anti- λ light chain antisera. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting of the monoclonal protein-rich γ-globulin fraction extracted from the sliced gel revealed the presence of two types of abnormal IgG molecule, low- and high-molecular-weight IgG, neither of which reacted with anti- κ or anti- λ light chain antisera. Additionally, an abnormal high-molecular-weight γ heavy chain was identified by reducing SDS-PAGE. These findings suggest that this monoclonal protein is composed only of γ heavy chains of normal and larger size. The presence of abnormal serum immunoglobulin composed of only γ heavy chain has been known as a fundamental feature of γ heavy chain disease (HCD). However, the unique composition of monoclonal γ-globulin makes our case distinct from typical γHCD, which is characterized by an abnormal truncated low-molecular-weight γ heavy chain. Thus, the unusual monoclonal protein may have been produced by a somatic mutation of IgH gene associated with splenic marginal-zone lymphoma.
Calibration of HbA1c and its measurement in the presence of variant haemoglobins: report on questionnaire to manufacturers
Authors: Manley S E , Round R A , Smith J M
Published: February 2006

Aims: To review 'Diabetes Control and Complications Trial (DCCT)-aligned' HbA1c reporting in UK, use of individual/network equations relating IFCC calibration to 'DCCT alignment', and whether HbA1c in the presence of variant haemoglobins is, according to manufacturers, suitable for current, clinical guidelines.

Methods: Questionnaire sent to nine manufacturers and responses analysed.

Results: All methods were certified as 'DCCT-aligned' by National Glycohemoglobin Standardization Program (NGSP); UK EQA schemes reported 95% of results 'DCCT-aligned' in December 2004. The master equation relating networks was used by six manufacturers and specific equations for individual methods by three. HbA1c results from laboratory/point of care testing analysers can be affected by variant haemoglobins including elevated HbF; only IE HPLC (and LPLC) detect their presence. If chromatographic separation is ideal in heterozygous patients, laboratories either choose not to report HbA1c and propose another strategy for monitoring glycaemia, or report HbA1c and issue a caution that it may not be appropriate for guidelines. HbA1c reported from immunochemistry or affinity chromatography in presence of variant haemoglobins, may not be reliable for use with clinical guidelines.

Conclusions: For clinical care, HbA1c must reflect its relationship to glycaemia in clinical trials underpinning national guidelines. A flowchart to establish if HbA1c measurement is appropriate has been produced for use in a clinical setting.
Increased urinary dopamine excretion in association with bilateral carotid body tumours - clinical, biochemical and genetic findings
Authors: Jeffery J , Devendra D , Farrugia J , Gardner D , Murphy MJ , Williams R , Ayling RM , Wilkin TJ
Published: February 2006

This report describes a rare case of a patient with increased urinary dopamine excretion in association with bilateral carotid body tumours. Excretion of adrenaline, noradrenaline, metadrenaline, normetadrenaline and 4-hydroxy-3-methoxymandelic acid (HMMA) were within the reference ranges, and an 123I-meta-iodobenzylguanidine (MIBG) scan showed uptake in the neck masses, with no other abnormal uptake anywhere else in the body. The patient is being managed conservatively as the tumours are not amenable to resection on account of their size and vascularity. There are only four previous case reports of dopamine-secreting tumours of the carotid body described in the literature, all of whom were women. The tumours were unilateral in three cases and bilateral in the fourth case. Familial cases of carotid body tumours have a higher prevalence of bilateral tumours than non-familial cases. Recent reports in the literature have suggested that a significant number of patients with extra-adrenal catecholamine-secreting paragangliomas have a genetic mutation in one of the identified susceptibility genes for catecholamine-secreting tumours, despite having no other affected family members, and a mutation has been found in the succinate dehydrogenase gene for this patient.
The value of measuring serum cholesterol-adjusted vitamin E in routine practice
Authors: Ford Loretta , Farr Jayne , Morris Paul , Berg Jonathan
Published: February 2006

Background: If the lipid concentration is not taken into account, then in certain situations the vitamin E status of a patient may be wrongly assigned based on serum measurement alone. In this study, the utility of using the calculated vitamin E:cholesterol ratio to determine vitamin E status was compared to the measurement of vitamin E alone.

Methods: The vitamin E:cholesterol ratio was measured in 457 patient samples received for routine vitamin E analysis. Serum vitamin E concentration was determined by high-performance liquid chromatography (HPLC) with UV detection and cholesterol concentration, using a Roche analyser and reagents.

Results: The mean vitamin E concentration and vitamin E:cholesterol ratio for the total study population was 22.0 μmol/L and 5.9 μmol/mmol, respectively. Of the 457 patient samples analysed, 57 (12.5%) were found to have a low vitamin E concentration, but only 25 (47%) of these patients had a low vitamin E:cholesterol ratio as well. Two patients both with cholestasis had a normal vitamin E concentration but low vitamin E:cholesterol ratio.

Conclusion: The determination of vitamin E:cholesterol ratios can be used to better define the vitamin E status of patients with disease states or disorders likely to raise LDL cholesterol, for example cholestasis. For the majority of samples, measurement of serum vitamin E concentration alone is sufficient to establish patient vitamin E status.
Validation of a liquid chromatography tandem mass spectrometry assay for serum creatinine and comparison with enzymatic and Jaffe methods
Authors: Owen Laura J , Wear Joanne E , Keevil Brian G
Published: February 2006

Background: Glomerular filtration rate (GFR) can be estimated using creatinine clearance or calculated formulae, methods which rely on creatinine quantification in serum. Creatinine is most frequently measured using the Jaffe method, but this is prone to interference by, for example, bilirubin, protein and ketones. Recent amendments to this assay have been made by manufacturers in an attempt to compensate for the protein interference.

Methods: We developed a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of creatinine in serum, using a strong cation exchange column to give a short run time of 1.5 min and minimal ion suppression. The method had a lower limit of quantification of 5 μmol/L and the intra- and inter-assay imprecision was <5% and <7%, respectively. Serum samples ( n = 182) were subsequently analysed by enzymatic, compensated Jaffe and LC-MS/MS methods and results compared.

Results: The compensated Jaffe and enzymatic methods gave similar results to the LC-MS/MS method at concentrations below 150 μmol/L. At concentrations above this value, creatinine was underestimated by both the compensated Jaffe and enzymatic methods compared with the LC-MS/MS method.

Conclusions: We have developed a novel, simple, sensitive LC-MS/MS assay for use in comparative studies or when the results of either Jaffe or enzymatic assays are in question.
Erythropoietin - measurement and clinical applications
Authors: Marsden Joanne T
Published: February 2006

Erythropoietin (EPO) is an endogenous hormone produced primarily by the kidney which controls the production of erythrocytes. The main stimulus to production is low tissue oxygen (hypoxia) and EPO triggers the formation of red blood cells by binding to a receptor on erythroid progenitor target cells. Alteration in the EPO regulatory system produces a change in circulating EPO in a variety of disease states, such as renal anaemia and polycythaemia. The availability of recombinant EPO in the 1980s transformed the treatment of anaemia, particularly anaemia of end stage renal disease, and led to the development of more sensitive and specific assays for the measurement of EPO. There are more widespread uses for EPO and preliminary studies indicate that EPO may be useful as a neuroprotective agent by reducing inflammation near the site of injury. The use of EPO to boost endurance in athletes has attracted unwanted publicity, although analytical techniques are now available that can differentiate between endogenous and recombinant EPO. Different types of erythropoietic agents have been developed with a longer plasma half-life and the ability to maintain haemoglobin levels for longer periods and reduce the need for frequent dosing with EPO.