bluuebunny/crossref_metadata_2025 huggingface dataset:
Opportunistic infections in polymyositis and dermatomyositis
Authors: Marie Isabelle , Hachulla Eric , Chérin Patrick , Hellot Marie‐France , Herson Serge , Levesque Hervé , Hatron Pierre‐Yves
Published: April 2005

Objective

To assess prevalence and characteristics of opportunistic infections in patients with polymyositis/dermatomyositis (PM/DM). To determine the predictive values for opportunistic infections on clinical presentation, biochemical findings, and paraclinical features of PM/DM to detect patients at risk of opportunistic infections.

Methods

The medical records of 156 consecutive PM/DM patients in 3 medical centers were reviewed.

Results

Eighteen PM/DM patients (11.5%) developed opportunistic infections. The majority of patients exhibited an opportunistic infection after the onset of PM/DM (89% of cases). Opportunistic infections occurred most frequently during the first year following PM/DM diagnosis (62.5%). The pathogen microorganisms responsible for opportunistic infections were various, i.e., Candida albicans, Pneumocystis carinii, Aspergillus fumigatus, Geotrichum capitatum, Mycobacterium avium‐intracellulare complex, M. xenopi, M. marinum, M. tuberculosis, Helicobacter heilmanii, cytomegalovirus, and herpes simplex virus. Mortality rates were as high as 27.7% in these PM/DM patients. Higher mean daily doses of steroids, lymphopenia, and lower serum total protein levels were significantly more frequent in the group of PM/DM patients with opportunistic infections.

Conclusion

Our study underscores the high frequency of opportunistic infections in PM/DM, resulting in an increased mortality rate. It also indicates that a great variety of microorganisms are responsible for opportunistic infections, although they were more often due to fungi (>50% of cases). Our series highlights a predominance of both lung and digestive opportunistic infections (89% of cases). In addition, our results suggest that PM/DM patients presenting with factors predictive of opportunistic infection may require closer monitoring.
An evaluation of novice end‐user computing performance: Data modeling, query writing, and comprehension
Authors: Chan H.C. , Teo H.H. , Zeng X.H.
Published: April 2005

End‐user computing has become a well‐established aspect of enterprise database systems today. End‐user computing performance depends on the user–database interface, in which the data model and query language are major components. We examined three prominent data models—the relational model, the Extended‐Entity‐Relationship (EER) model, and the Object‐Oriented (OO) model—and their query languages in a rigorous and systematic experiment to evaluate their effects on novice end‐user computing performance in the context of database design and data manipulation. In addition, relationships among the performances for different tasks (modeling, query writing, query comprehension) were postulated with the use of a cognitive model for the query process, and are tested in the experiment. Structural Equation Modeling (SEM) techniques were used to examine the multiple causal relationships simultaneously. The findings indicate that the EER and OO models overwhelmingly outperformed the relational model in terms of accuracy for both database design and data manipulation. The associations between tasks suggest that data modeling techniques would enhance query writing correctness, and query writing ability would contribute to query comprehension. This study provides a better and thorough understanding of the inter‐relationships among these data modeling and task factors. Our findings have significant implications for novice end‐user training and development.
Synthesis, Spectroscopic and Nonlinear Optical Properties of Multiple [60]Fullerene–Oligo(p‐phenylene ethynylene) Hybrids
Authors: Zhao Yuming , Shirai Yasuhiro , Slepkov Aaron D. , Cheng Long , Alemany Lawrence B. , Sasaki Takashi , Hegmann Frank A. , Tour James M.
Published: April 2005

A series of multiple [60]fullerene terminated oligo(p‐phenylene ethynylene) (OPE) hybrid compounds has been synthesized through a newly developed in situ ethynylation method. Structural and magnetic shielding properties of the highly unsaturated carbon‐rich C60 and OPE scaffolds were characterized by 1D and 2D NMR spectroscopic analyses. Electronic interactions between the [60]fullerenes and the OPE backbones were investigated by UV/Vis spectroscopic and cyclic voltammetry (CV) experiments. Our studies clearly show that although the multiple [60]fullerene groups are connected via π‐conjugated OPE frameworks, they present diminutive electronic interactions in the ground state, and the electronic behavior of the [60]fullerene cages are only affected by the OPE backbones through modest inductive effects. Interestingly, sizable third‐order nonlinear optical (NLO) responses (γ) and enhanced two‐photon absorption (TPA) cross‐sections (σ(2)) were determined for the multifullerene–OPE hybrid 31 relative to its OPE precursor from differential optical Kerr effect (DOKE) experiments. Such enhanced NLO performance is presumably due to the occurrence of periconjugation and/or charge transfer effects in the excited state. In addition, comparatively strong excited‐state absorption was observed and characterized for OPE pentamer 12. Thus, the use of such fullerene‐derivatized conjugated oligomers aids the quest for molecules with large third‐order NLO and TPA properties.
Syntheses, Structures, Photoluminescence and Theoretical Studies of Xanthone in Crystalline Resorcinarene‐Based Inclusion Complexes
Authors: Zheng Shao‐Liang , Coppens Philip
Published: April 2005

Two new crystalline resorcinarene‐based xanthone inclusion complexes, CECR⋅xanthone⋅MeOH (1), and HECR⋅2 xanthone⋅6 MeOH (2) (CECR=C‐ethylcalix[4]resorcinarene, HECR=hexaethylresorcin[6]arene) have been prepared to study the relation between photophysical properties and solid‐state structure. Compared with the neat crystals, the xanthone phosphorescence is severely quenched in both solids, but the lifetime is an order of magnitude larger in 2, in which xanthone occurs as a dimer, than in 1, in which it occurs as a monomer. The electronic transitions involved in the photoluminescent process, and the relation between the energy levels of host and guest and emission quenching of the guest in the supramolecular solid have been investigated by means of time‐dependent density functional theory (TDDFT) calculations.
Prostaglandin D2 affects the differentiation and functions of human dendritic cells: impact on the T cell response
Authors: Gosset Philippe , Pichavant Muriel , Faveeuw Christelle , Bureau Fabrice , Tonnel André‐Bernard , Trottein François
Published: April 2005

The local environment in which dendritic cells (DC) differentiate is important for the acquisition of their immunostimulatory properties. Since prostaglandin D2 (PGD2), a major prostanoid produced during inflammatory reactions, is involved in the control of immune responses, its effect on the differentiation and functions of human monocyte‐derived dendritic cells (MDDC) was studied. We show that DC differentiated in the presence of PGD2 (PG/DC) have an unusual phenotype, with modifications in the expression of molecules involved in antigen (Ag) capture and presentation, leading to higher endocytic and Ag‐processing activities. However, under conditions that necessitated Ag processing and presentation, PG/DC have an impaired ability to stimulate naive T cells, whereas superAg‐pulsed DC efficiently promote their proliferation. Upon lipopolysaccharide or TNF‐α/IL‐1β stimulation, PG/DC phenotypically mature but produce abnormal amounts of immunoregulatory cytokines (decreased IL‐12p70/IL‐10 ratio). Moreover, mature PG/DC fail to up‐regulate the chemokine receptor CCR7 and show an impaired migration towards its ligand CCL19. Finally, PG/DC favor the differentiation of naive T cells toward Th2 cells, an effect dependent on IL‐10 and inducible costimulator ligand expression by DC. Most of the herein described effects of PGD2 on MDDC can be reproduced, usually with a higher efficacy, with a selective D prostanoid receptor (DP)1, but not DP2, agonist. Taken as a whole, these results demonstrate that PGD2 impacts DC differentiation and functions, and extend the concept that it exerts important roles in immunity.
Binding of Oxovanadium(IV) to Dipeptides Containing Histidine and Cysteine Residues
Authors: Garribba Eugenio , Lodyga‐Chruscinska Elzbieta , Micera Giovanni , Panzanelli Angelo , Sanna Daniele
Published: April 2005

The complexation of the oxovanadium(IV) ion with five dipeptides containing L‐histidine or L‐cysteine (GlyHis, HisHis, HisGly, CysGly, GlyCys) was studied. L‐histidinamide (HisNH2) was assumed as a model system for dipeptides with L‐histidine in the N‐terminal position. The study was performed in aqueous solution through the combined application of potentiometric and spectroscopic (electronic absorption and EPR) techniques. The results indicate that simple dipeptides lacking a strong anchoring group can form mono‐ and bischelated complexes with the VIVO ion if a suitable “donor” is present in the chain. The ligands behave like amino acids in the acidic and neutral pH range, inhibit the precipitation of hydroxides and suppress the formation of hydrolytic species if at least a fivefold molar excess of ligand is used. In alkaline media all the ligands, except CysGly, promote the deprotonation and N‐coordination of the amide group. CysGly forms a bischelated complex with a [2  (NH2, S–)] donor set. The contribution of the deprotonated amide group to the 51V hyperfine coupling constant, Az, as a function of the total equatorial charge of oxovanadium(IV) ion, is discussed. The results have general validity and are useful to predict the geometry and donor set of complexes involving the bonding of the VIVO ion to the deprotonated amide group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Syntheses, Structures, and Magnetic Properties of Two 1D, Mixed‐Ligand, Metal Coordination Polymers, [M(C4O4)(dpa)(OH2)] (M = CoII, NiII, and ZnII; dpa = 2,2'‐dipyridylamine) and [Cu(C4O4)(dpa)(H2O)]2·(H2O)
Authors: Wang Chih‐Chieh , Yang Cheng‐Han , Lee Gene‐Hsiang , Tsai Hui‐Lien
Published: April 2005

Two metal coordination polymers with general formula [M(dpa)(C4O4)(H2O)] [M = Co (1), Ni (2), Zn (3); dpa = 2,2'‐dipyridylamine] and [Cu(dpa)(C4O4)(H2O)]2·H2O (4) have been synthesized under hydrothermal conditions. The single‐crystal X‐ray analyses reveal that compounds 1–3 are isostructural and possess distorted octahedral metal centers coordinated by two squarates, one dpa, and two water molecules. A 1D two‐legged ladder‐like framework is formed by interconnection of the water‐bridged [M(dpa)(μ2‐OH2)]24+ dimeric fragments and μ1,2‐squarate ligands. Intra‐ and intermolecular hydrogen bonds between squarate, water, and dpa ligands, as well as the π‐π stacking interaction of the pyridyl ring in the dpa ligands, provide extra forces to stabilize the extended network. Conversely, the molecular structure of compound 4 contains two distorted square‐pyramidal CuII centers coordinated by two squarates, one dpa ligand, and one water molecule. The squarates adopt a μ1,2‐binding mode to link the Cu centers and form a 1D helical chain. For compound 2, the magnetic exchange couplings between metal centers are analyzed with a binuclear magnetic model. The resulting negative magnetic exchange coupling constant indicates an antiferromagnetic interaction within the dimers. The magnetic behavior of compound 4 is typical of paramagnetic CuII ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Photocontrol of Complexation of Neutral and Cationic Species by p‐tert‐Butylcalix[4]arene Tetraethyl Ester
Authors: Creaven Bernadette S. , Deasy Mary , McKenna Catherine , Murray Brian A. , Tobin Darren
Published: April 2005

A number of sodium salt complexes of p‐tert‐butylcalix[4]arene tetraethyl ester (1) were isolated both with and without upper‐rim encapsulated acetonitrile or methanol. Upon dissolution in CDCl3, 1 remained largely complexed to the sodium cation but ca. 90 % of the upper‐rim bound solvent was released, reflecting the relative values of the binding constants for complexation of the two guest species. Selective decomplexation of lower‐rim bound sodium cations could be successfully achieved using low‐pressure light sources, triggering the immediate expulsion of the upper‐rim bound solvent. The extent of decomplexation at both rims is controlled both by the oxidation of the counter‐anionic species at the lower rim and by the fate of the photoproducts generated. The calixarene host molecule, 1, remains intact during the decomplexation process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
[H2bpy]2[{Cu(btepy)2}Mo5P2O23]·4H2O: A Three‐Dimensional Framework Built from Transition‐Metal Coordination Polymer Sheets Pillared by Polyoxomolybdophosphate Clusters
Authors: Lu Ying , Li Yangguang , Wang Enbo , Lü Jian , Xu Lin , Clérac Rodolphe
Published: April 2005

[H2bpy]2[{Cu(bpy)2}Mo5P2O23]·4 H2O (1; bpy = 4,4'‐bipyridine) contains the first three‐dimensional framework based on two‐dimensional transition metal coordination polymer sheets pillared by polyoxomolybdophosphate clusters. It crystallises in the C2/c monoclinic space group with a = 17.630(4) Å, b = 13.670(3) Å, c = 25.111(5) Å, and β = 106.61(3)°. Thermogravimetric analysis shows that guest molecules (H2O and free bpy ligands) can be easily removed from 1 by simple heat treatment without losing the three‐dimensional framework. Moreover, the paramagnetic properties of the {Cu(bpy)2} arrays, make this material an interesting magnetic solid based on polyoxometallate clusters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Thermal Properties of [M10Se4(SePh)12(PR3)4] (M = Zn, Cd, Hg)Cluster Molecules – Synthesis and Structure of[Cd32Se14(SePh)36(L)4]; L = OPPh3, OC4H8
Authors: Eichhöfer Andreas
Published: April 2005

A series of four different M10 selenide cluster molecules of the general formula [M10Se4(SePh)12(PR3)4] (M = Zn, Cd, Hg; R = organic group) have been synthesized by the reaction of metal chlorides MCl2 (M = Zn, Cd, Hg) with phosphanes PR3, Se(SiMe3)2 and PhSeSiMe3 in organic solvents. The investigations of the thermal properties by thermogravimetric analysis (TGA) reveal that [Zn10Se4(SePh)12(PnPr2Ph)4], [Cd10Se4(SePh)12(PEt3)4], [Cd10Se4(SePh)12(PnPr3)4] and [Hg10Se4(SePh)12(PnPrPh2)4] form the corresponding bulk chalcogenides in mainly two‐ or three‐step processes. From the intermediate product of the first step of the vacuum thermolysis of [Cd10Se4(SePh)12(PnPr3)4] we were able to obtain in solution the larger cluster molecule [Cd32Se14(SePh)36‐(OC4H8)4] and upon addition of OPPh3 its homologue [Cd32Se14(SePh)36(OPPh3)4]. The structures of both molecules have been determined by single‐crystal XRD. Obviously, the smaller Cd10 cluster grows upon thermal treatment in the solid state to form larger cluster cores. However, optical spectra and dynamic light scattering of the dissolved residues reveal that this growth is not totally specific. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Pyrazole‐Tethered Heteroditopic Ligands and Their Transition Metal Complexes: Synthesis, Structure, and Reactivity
Authors: Mukherjee Anuradha , Subramanyam U. , Puranik Vedavati G. , Mohandas Thekke P. , Sarkar Amitabha
Published: April 2005

Various pyrazole‐based P,N (2a–c) and N,N (3a–b) ligands have been synthesized. Using representative ligands, NiII, CoII, CuII, and CuI complexes have been prepared and structurally characterized by crystallography. During complexation of CoII and CuII salts, the phosphane part of the P,N ligand oxidized to phosphane oxide. For N,N donor ligands, a dimeric chloro‐bridged NiII complex was obtained. NiII complex 4 is an active catalyst for ethylene oligomerization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Trinuclear Oxo‐Centered Iron and Iron/Nickel Clusters – Ligand‐Controlled Homo/Hetero Valency
Authors: Saalfrank Rolf W. , Scheurer Andreas , Pokorny Klaus , Maid Harald , Reimann Uwe , Hampel Frank , Heinemann Frank W. , Schünemann Volker , Trautwein Alfred X.
Published: April 2005

Cleavage of the all‐iron(III) μ2‐O2–‐linked dimer [FeIII3O(L)2‐(OAc)4]2O (3) with lithium chloride yields [FeIII3O(L)2(OAc)4]Cl (4) and with sodium benzoate, in combination with complete acetate‐to‐benzoate coligand exchange, gives [FeIII3O(L)2‐(OBz)4]OBz (5). Reduction of the all‐FeIII complex 5 [Fe/L/OBz = 3:2:(4+1)] with sodium iodide affords the homonuclear mixed‐valent cluster [FeIIFeIII2O(L)3(OBz)3] (6) (Fe/L/OBz = 1:1:1) and requires fundamental coligand‐to‐ligand exchange. Likewise, when the all‐FeIII dimer [FeIII3O(L)2(OAc)4]2O (3) (Fe/L/OAc = 3:2:4) is cleaved with nickel acetate, the mixed‐valent heteronuclear complex [NiIIFeIII2O(L)3(OAc)3] (7) (M/L/OAc = 1:1:1) is formed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Di‐ and Trivalent Lanthanide Complexes Stabilized by Sterically Demanding Aminopyridinato Ligands
Authors: Scott Natalie M. , Kempe Rhett
Published: April 2005

Deprotonation of Ap*H {Ap*H = (2,6‐diisopropylphenyl)‐[6‐(2,4,6‐triisopropylphenyl)pyridin‐2‐yl]amine} and Ap'H {Ap'H = (2,6‐diisopropylphenyl)‐[6‐(2,6‐dimethylphenyl)pyridin‐2‐yl]amine} using KH leads to polymeric [Ap*K]n and [Ap'K]n which undergo clean salt metathesis reactions with NdCl3 in THF forming [Nd(Ap*)Cl2(THF)2]2 and [Nd(Ap')2‐Cl(THF)], respectively. Ethylene polymerization activities of the two chloro complexes (after activation with MAO) were studied. Derivatization of the chloro compounds proceeds without ate complex formation, for instance the reaction of [Nd(Ap')2Cl(THF)] with one equiv. of [K{N(SiMe3)2}] leads to the “THF‐free” silylamide [Nd(Ap')2{N(SiMe3)2}]. Furthermore rare examples of heteroleptic amido‐iodo complexes of selected divalent lanthanides can be stabilized by deprotonated Ap*H. Reaction of [Ap*K]n with [LnI2(THF)3] (Ln = Yb, Sm) in THF leads, after workup in hexane, to [Yb(Ap*)I‐(THF)2]2 and [Sm(Ap*)I(THF)2]2. All lanthanide complexes, four of them are paramagnetic, were characterized by X‐ray crystal structure analysis. These compounds exhibit an excellent solubility in nonpolar solvents like hexane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Endohedral Metallocenophanes of Rhodium and Cobalt
Authors: Schaefer Carsten , Scholz Gerald , Gleiter Rolf , Oeser Thomas , Rominger Frank
Published: April 2005

The synthesis of seven endohedral metallocenophanes of rhodium (7b, 8b) and cobalt (1d−h) with a cyclopentadienyl unit as one of the π‐systems and a cyclobutadiene or cyclopentadienone unit as the second π‐system is described, including the synthesis of the unsubstituted parent compound of the [CpCo(cbd)]‐derived endohedral phanes, [3.3]‐η5‐(1,1',3,3')‐cyclopentadienyl–η4‐(cyclobutadienophane)co‐balt(I) (1h). This compound could be obtained by deprotection of the corresponding trimethylsilyl‐substituted endohedral phane 1g. The X‐ray structures of 7b, 1e, 1g and 1h could be obtained. This paper compares their structural properties to the complexes reported in previous short communications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Heteroditopic Imino N‐Heterocyclic Carbenes and Their Sulfur, Selenium, and Tungsten Tetracarbonyl Derivatives
Authors: Steiner Georg , Kopacka Holger , Ongania Karl‐Hans , Wurst Klaus , Preishuber‐Pflügl Peter , Bildstein Benno
Published: April 2005

New heterditopic imino N‐heterocyclic carbenes for use as chelating ligands in homogeneous catalysis are the focus of this contribution. The synthesis of the corresponding imid‐azolium precursors is accomplished in three steps by alkylation of imidazole with ketoalkyl bromides, imination of the carbonyl functionality with anilines, either by conventional methods or by an aluminum‐assisted condensation, and methylation using highly electrophilic methyl triflate. Deprotonation of the imidazolium triflates with potassium hydride gives a different outcome depending on the substitution pattern of the iminomethyl moiety: iminomethyl N‐heterocyclic carbenes containing a methylene group between the imino moiety and the N‐heterocycle are unstable because of tautomerization to the corresponding methylene‐deprotonated ylides. In contrast, iminoisopropyl N‐heterocyclic carbenes, where the acidic site of the methylene group is blocked by two methyl groups, are stable in solution, as proven by 1H and 13C NMR spectroscopy. First derivatives of these new [N,C]‐ligands include their sulfur and selenium oxidation products (iminoisopropylimidazolin‐2‐thione and ‐selenone, respectively) as well as a tungsten tetracarbonyl complex with a six‐membered [N,C] chelating moiety. All new products were fully characterized by multinuclear NMR (1H, 13C, 77Se, 183W) and IR spectroscopy, mass spectrometry, as well as by X‐ray single crystal structures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Zinc Thiolate Complexes of (N,N,S)‐Tridentate Ligands for the Modeling of Thiolate Alkylating Enzymes
Authors: Ji Mian , Vahrenkamp Heinrich
Published: April 2005

Zinc thiolate complexes of three tridentate (N,N,S) ligands were prepared as models for the structure and function of thiolate alkylating zinc enzymes. N‐(2‐Mercaptoisobutyl)(2‐pyridin‐2‐yl‐methyl)amine (L1) forms isobutylthiolate‐bridged dinuclear complexes with ZnN2S3 coordination. N‐(2‐Mercaptoisobutyl)(2‐pyridin‐2‐yl‐ethyl)amine (L2) yields isobutylthiolate‐bridged dinuclear complexes in which the pyridine donor is not coordinated to zinc, resulting in a ZnNS3 coordination. Only N‐(2‐mercaptoisobutyl)(2‐pyridin‐2‐yl‐ethyl)methylamine (L3) forms the desired mononuclear complexes with ZnN2S2 coordination. The latter react with the alkylating agents CH3I and PO(OCH3)3 in a two‐step process. In the first step the isobutylthiolate function is methylated and its position in the ligand sphere of zinc is taken by I– or OPO(OCH3)2–, respectively, and in the second step the additional thiolate ligand is methylated and replaced by a second iodide or dimethyl phosphate anion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Reduction of CCl4 by Iron Powder in Aqueous Solution
Authors: Rusonik Irena , Cohen Haim , Meyerstein Dan
Published: April 2005

·CCl3 radicals formed in the first step of the CCl4 degradation react with iron powder to form an intermediate with an Fe–C σ bond. In the absence of iron powder, ·CCl3 radicals formed by γ‐irradiation react with 2‐propanol in a chain reaction toward dechlorination. When the irradiated solution contains iron powder, the iron scavenges the ·CCl3 radicals, thus inhibiting the chain reaction. The minor product of the dechlorination of CCl4 by iron powder in aqueous solution is CH4, contrary to the results reported in the literature for the electrochemical reduction of CCl4 on iron electrodes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Si‐, Ge‐, and Sn‐Centered Free Radicals: From Phantom Species toGrams‐Order‐Scale Materials
Authors: Lee Vladimir Ya. , Sekiguchi Akira
Published: April 2005

Recent developments in the field of the stable free radicals of heavier group 14 elements are reviewed, covering both neutral and charged radical species. The electronic and crystal‐structural features of these radicals, both in the solid state and in solution, are compared with each other. The most important parameters affecting the stability, geometry and electronic configuration of the radicals are discussed on the basis of the latest experimental and computational data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Sediment budget for an eroding peat‐moorland catchment in northern England
Authors: Evans Martin , Warburton Jeff
Published: April 2005

This paper describes a detailed contemporary sediment budget from a small peat‐covered, upland catchment in Upper Teesdale, northern England. The sediment budget was constructed by measuring: (1) sediment transfers on slopes, (2) sediment flux on the floodplain and through the main stream channel and (3) sediment yield at the catchment outlet. Measurements were taken over a four‐year monitoring period between July 1997 and October 2001 when interannual variations in runoff were relatively small. Three sites were selected to represent the major erosion subsystems within the catchment: an area of bare peat flats, a pair of peat gullies, and a 300 m channel reach. Collectively the sites allow detailed characterization of the main patterns of sediment flux within the catchment and can be scaled up to provide an estimate of the sediment budget for the catchment as a whole. This constitutes the first attempt to provide a complete description of the functioning of the sediment system in eroding blanket peatlands. Results demonstrate that fluvial suspended sediment flux is controlled to a large degree by channel processes. Gully erosion rates are high but coupling between the slopes and channels is poor and therefore the role of hillslope sediment supply to catchment output is reduced. Consequently contemporary sediment export from the catchment is controlled primarily by in‐channel processes. Error analysis of the sediment budgets is used to discuss the limitations of this approach for assessing upland sediment dynamics. A 60 per cent reduction in fluvial suspended sediment yield from Rough Sike over the last 40 years correlates with photographic evidence of significant re‐vegetation of gullies over a similar period. This strongly suggests that the reduced sediment yields are a function of increased sediment storage at the slope–channel interface, associated with re‐vegetation. Copyright © 2005 John Wiley & Sons, Ltd.
Predictability of river flow and suspended sediment transport in the Mississippi River basin: a non‐linear deterministic approach
Authors: Sivakumar Bellie , Wallender Wesley W.
Published: April 2005

As the Mississippi River plays a major role in fulfilling various water demands in North America, accurate prediction of river flow and sediment transport in the basin is crucial for undertaking both short‐term emergency measures and long‐term management efforts. To this effect, the present study investigates the predictability of river flow and suspended sediment transport in the basin. As most of the existing approaches that link water discharge, suspended sediment concentration and suspended sediment load possess certain limitations (absence of consensus on linkages), this study employs an approach that presents predictions of a variable based on history of the variable alone. The approach, based on non‐linear determinism, involves: (1) reconstruction of single‐dimensional series in multi‐dimensional phase‐space for representing the underlying dynamics; and (2) use of the local approximation technique for prediction. For implementation, river flow and suspended sediment transport variables observed at the St. Louis (Missouri) station are studied. Specifically, daily water discharge, suspended sediment concentration and suspended sediment load data are analysed for their predictability and range, by making predictions from one day to ten days ahead. The results lead to the following conclusions: (1) extremely good one‐day ahead predictions are possible for all the series; (2) prediction accuracy decreases with increasing lead time for all the series, but the decrease is much more significant for suspended sediment concentration and suspended sediment load; and (3) the number of mechanisms dominantly governing the dynamics is three for each of the series. Copyright © 2005 John Wiley & Sons, Ltd.
Estimation and propagation of error in measurements of river channel movement from aerial imagery
Authors: Mount Nicholas , Louis John
Published: April 2005

Rates of river channel migration or widening are only valid if it can be demonstrated that the amount of change in the measured parameters exceeds the measurement errors. However, it is still uncommon to see estimates of errors presented alongside rates of river channel change measured from aerial photography. Here, detailed methods are presented for the estimation of errors in quantifying channel migration rates that can be easily applied to GIS‐based analysis of planform change. In addition, the impact of relaxing assumptions regarding error independence between image dates and systematic registration errors is presented and discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Contrasting flow pathways within tropical forest slopes of Ultisol soils
Authors: Chappell Nick A. , Sherlock Mark D.
Published: April 2005

There are very few experimental studies identifying hydrological pathways within rain forest slopes. Such knowledge is, however, necessary to understand why forest disturbance affects rainfall–riverflow response and nutrient migration. This study examines flow pathways within lowland rain forest slopes comprising Udults of the Ultisol soil order. Experimentation was conducted on four SE Asian hillslope units (each 5 × 5 m in plan) in the Bukit Timah catchment (Singapore Island), and in the W8S5 catchment (Sabah, Borneo Island). The flow pathways were identified by artificial tracer experiments. We evaluated how well hydrometric calculations based on tensiometry and permeametry measurements predicted the tracer patterns.

The tracer work indicated much faster subsurface flows at Bukit Timah than W8S5 for the storms studied. Some explanation of the greater subsurface waterflows at Bukit Timah in comparison to W8S5 is afforded by the less steep moisture release curves which maintain hydraulic conductivity as the soil dries. Vertical flow of the tracer through the upper 1 m of soil predominated (>90 per cent of percolation) in the Bukit Timah slopes. In some contrast, a major component (approximately 60 per cent) of the tracer percolation was directed laterally within the W8S5 slopes. The flow vectors calculated using the hydrometric methods did, however, grossly under‐estimate the degree of lateral deflection of waterflow generated at W8S5 and to a lesser extent over‐estimated it at Bukit Timah. In part, these errors may relate to the inability of traditional hydrometric techniques to fully characterize the effect of the large and small ‘natural soil pipes’ present within both catchments. In conclusion, the study indicates that marked variations in flow vectors exist within the Udult great group of SE Asian soils and hydrometric calculations may be poor predictors of these dominant pathways. Copyright © 2005 John Wiley & Sons, Ltd.
Solution of the planar Newtonian stick–slip problem with the singular function boundary integral method
Authors: Elliotis M. , Georgiou G. , Xenophontos C.
Published: April 2005

A singular function boundary integral method (SFBIM) is proposed for solving biharmonic problems with boundary singularities. The method is applied to the Newtonian stick–slip flow problem. The streamfunction is approximated by the leading terms of the local asymptotic solution expansion which are also used to weight the governing biharmonic equation in the Galerkin sense. By means of the divergence theorem the discretized equations are reduced to boundary integrals. The Dirichlet boundary conditions are weakly enforced by means of Lagrange multipliers, the values of which are calculated together with the singular coefficients. The method converges very fast with the number of singular functions and the number of Lagrange multipliers, and accurate estimates of the leading singular coefficients are obtained. Comparisons with the analytical solution and results obtained with other numerical methods are also made. Copyright © 2005 John Wiley & Sons, Ltd.
Corroboration of a familial chordoma locus on chromosome 7q and evidence of genetic heterogeneity using single nucleotide polymorphisms (SNPs)
Authors: Yang Xiaohong (Rose) , Beerman Michael , Bergen Andrew W. , Parry Dilys M. , Sheridan Eamonn , Liebsch Norbert J. , Kelley Michael J. , Chanock Stephen , Goldstein Alisa M.
Published: April 2005

Chordoma, a rare bone tumor originating from notochordal remnants, has a genetic predisposition in some families. Previously, we performed linkage analysis using microsatellite (STR) markers on 3 unrelated chordoma kindreds (16 patients with chordoma) and reported significant evidence for linkage to chromosome 7q33 (Zmax = 4.78) with a minimal disease gene region of 11 cM. In our present study, we performed linkage analysis in these 3 families using chromosome 7 single nucleotide polymorphisms (SNPs). Parametric and nonparametric multipoint analyses showed significant linkage to 7q markers with p < 0.001 and Zmax = 2.77, respectively. The minimal disease gene region was not reduced by combined SNP and STR haplotype analysis compared to the previous STR haplotype analysis alone. We genotyped members of a fourth chordoma family with SNP and STR markers for chromosome 7q and for 1p36, the location of a previously reported chordoma locus. Affected members of this family did not share a common haplotype on 7q, and the family did not show evidence of linkage to 1p36. Thus, we corroborated a chordoma locus on chromosome 7q in the 3 original families and demonstrated evidence for genetic heterogeneity in the fourth family. Our study also provided insights into some limitations and analytical complexities associated with using a dense SNP marker set in linkage analysis of complex pedigrees. © 2005 Wiley‐Liss, Inc.
Peroxisome proliferator‐activated receptor γ agonist troglitazone induces colon tumors in normal C57BL/6J mice and enhances colonic carcinogenesis in Apc1638 N/+Mlh1+/− double mutant mice
Authors: Yang Kan , Fan Kun‐Hua , Lamprecht Sergio A. , Edelmann Winfried , Kopelovich Levy , Kucherlapati Raju , Lipkin Martin
Published: April 2005

The role of the nuclear peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) in colon tumorigenesis remains controversial. Notwithstanding evidence that PPAR‐γ ligands impede murine colorectal carcinogenesis, PPAR‐γ agonists have been shown to enhance in vivo tumor formation in mouse models of human colon cancer. Our study was designed to determine whether troglitazone (TGZ) induces colonic tumor formation in normal C57BL/6J mice and enhances colorectal carcinogenesis in double mutant Apc1638N/+Mlh1+/− mice fed a standard AIN‐76A diet. We report herein that not only does TGZ enhance carcinogenesis in the large intestine of mutant mice predisposed to intestinal carcinogenesis but TGZ also induces colonic tumors in normal mice without gene targeting or carcinogen administration. This observation indicates that preexisting mutational events are not necessary for induction of colonic tumors by activated PPAR‐γ in vivo. © 2005 Wiley‐Liss, Inc.
Loss of Cyclin B1 followed by downregulation of Cyclin A/Cdk2, apoptosis and antiproliferation in Hela cell line
Authors: Xie Xian He , An Hee Jung , Kang Suki , Hong Sunghui , Choi Yoon Pyo , Kim Young Tae , Choi Young Deuk , Cho Nam Hoon
Published: April 2005

Recent studies have shown that Cyclin B1 is overexpressed in various tumor types but present at low levels in normal tissues. To explore the possibility of employing Cyclin B1 as an anticancer target, we knocked down Cyclin B1 in an HeLa cell line using RNA interference (RNAi). Subsequently, we monitored cell cycle‐related molecules by Western blot together with immunofluorescence and determined cell cycle distribution by flow cytometry. XTT and soft agar colony growth experiments were performed to detect cell viability and proliferation. Furthermore, we analyzed cell apoptosis by measuring Bcl‐2 and Bax protein level and DNA‐ladder assay. After performing Cyclin B1 RNAi, Cyclin B1, Cyclin A and Cdk2 protein levels were found to be markedly downregulated, whereas Cdc2 was almost unaffected; S‐phase fraction increased significantly; HeLa cell viability and cell colony forming ability were markedly diminished after the RNAi; Bcl‐2 was noticeably attenuated but Bax was hardly changed; and HeLa cells displayed typical DNA ladder. The loss of Cyclin B1 resulted in the downregulation of Cyclin A and Cdk2, S‐phase delay and eventually led to cell apoptosis and the decrease of cell viability and proliferation. Our studies suggest that Cyclin B1 may be a promising anticancer target. © 2005 Wiley‐Liss, Inc.
Risk factors for thyroid cancer: A prospective cohort study
Authors: Navarro Silvera Stephanie A. , Miller Anthony B. , Rohan Thomas E.
Published: April 2005

Given the higher incidence rate of thyroid cancer among women compared to men and evidence that smoking and alcohol consumption may be inversely related to thyroid cancer risk, we examined thyroid cancer risk in association with menstrual, reproductive and hormonal factors, and cigarette and alcohol consumption, in a prospective cohort study of 89,835 Canadian women aged 40–59 at recruitment who were enrolled in the National Breast Screening Study (NBSS). Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths from all causes, respectively, with follow‐up ending between 1998 and 2000. Cox proportional hazards models (using age as the time scale) were used to estimate hazard ratios and 95% confidence intervals for the association between each of the potential risk factors and risk of thyroid cancer overall and by the main histologic subtypes. During a mean of 15.9 years of follow‐up, we observed 169 incident thyroid cancer cases. There was no evidence of altered overall thyroid cancer risk with any of the menstrual, reproductive, or hormonal factors. There was evidence of a decreased risk of papillary thyroid cancer among women with 5 or more live births (vs. nulliparous). Age at which smoking commenced, duration of smoking, number of cigarettes smoked per day, pack‐years of smoking and alcohol consumption were not associated with altered thyroid cancer risk. The present study provides little support for associations with hormonal factors, smoking, or alcohol consumption, but there is a need for additional prospective data. © 2005 Wiley‐Liss, Inc.
Novel platinum(IV) complexes induce rapid tumor cell death in vitro
Authors: Kaludjerović Goran N. , Miljković Djordje , Momcilović Miljana , Djinović Vesna M. , Stojković Marija Mostarica , Sabo Tibor J. , Trajković Vladimir
Published: April 2005

The anticancer activity of platinum complexes has been known since the discovery of classical Pt(II)‐based drug cisplatin. However, Pt(IV) complexes have greater inertness than corresponding Pt(II) complexes, thus allowing the oral administration and reducing the toxicity associated with platinum‐based chemotherapy. Here, we describe the in vitro antitumor activity of some novel Pt(IV)‐based agents against mouse fibrosarcoma L929 cells and human astrocytoma U251 cells. The cytotoxicity of 2 Pt(IV) complexes with bidentate ethylenediamine‐N,N′‐di‐3‐propanoato esters was found to be markedly higher than that of their Pt(II) counterparts and comparable to the antitumor action of cisplatin. In contrast to cisplatin, which caused oxidative stress‐independent apoptotic cell death of tumor cells, these Pt(IV) complexes induced oxygen radical‐mediated tumor cell necrosis. Importantly, the cytotoxic action of novel Pt(IV) complexes was markedly more rapid than that of cisplatin, indicating their potential usefulness in anticancer therapy. © 2005 Wiley‐Liss, Inc.
Periodically expanding discounted debt: a threat to fiscal policy sustainability?
Authors: Davig Troy
Published: April 2005

This paper models the behaviour of discounted US debt using a Markov‐switching time series model. The significance of modelling fiscal policy within this framework derives from the implications it has for long‐term sustainability. The two‐regime framework used in this paper identifies periods where the present value of US Federal debt is expanding versus periods when it is collapsing. Using an updated data series from Hamilton and Flavin (1986), a test is conducted to establish if the expanding periods pose a threat to the long‐run sustainability of fiscal policy. For the USA, it is found that they do not. Copyright © 2005 John Wiley & Sons, Ltd.
Erratum to "Solvation forces on biomolecular structures: A comparison of explicit solvent and Poisson‐Boltzmann models," by Jason Wagoner and Nathan A. Baker
Authors: Wagoner Jason , Baker Nathan A.
Published: April 2005

The original article to which this Erratum refers was published in Journal of Computational Chemistry (2004) 25(13) 1623–1629
A topological lower bound for the circular chromatic number of Schrijver graphs
Authors: Meunier Frédéric
Published: April 2005

In this paper, we prove that the Kneser graphs defined on a ground set of n elements, where n is even, have their circular chromatic numbers equal to their chromatic numbers. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 257–261, 2005
What is the role of muscle receptors in proprioception?
Authors: Proske Uwe
Published: April 2005

The role of muscle afferents is discussed in terms of their contribution to kinesthesia, the senses of position and movement of the limbs. It is argued that muscle spindles are not well suited as position sensors, on several grounds. Yet we know from muscle vibration experiments that they do contribute to kinesthesia. A number of recent experiments have shown that positional information is of particular significance to the central nervous system. In other experiments it has been demonstrated that a disturbance to kinesthesia follows fatigue from exercise. Fatigue of elbow flexor muscles led subjects to make significant positional errors in a forearm matching task. The size of the errors correlated with the fall in force from fatigue. These data suggest that we derive a positional cue from the effort required to hold a limb against the force of gravity. A challenge for the future will be to reveal how the centrally derived sense of effort and peripherally derived afferent information interact to give us our kinesthetic sense. Muscle Nerve, 2005
Exact solution of the centralized network design problem on directed graphs
Authors: Gzara Fatma , Goffin Jean‐Louis
Published: April 2005

We present a novel exact solution method for the centralized network design problem on directed graphs. The problem is modeled as the well‐known graph theoretic problem: the capacitated directed spanning tree problem. We propose a Lagrangian relaxation where the subproblem is a directed spanning tree with a degree constraint on the root. The master problem has an exponential number of constraints and variables. To solve it, we present a cut‐and‐column generation algorithm based on analytic centers. The latter solves a restricted master problem using a primal analytic center cutting plane method and strengthens the bound by generating columns that correspond to violated primal constraints. The Lagrangian bound is embedded within branch‐and‐bound leading to an interior point branch‐and‐price algorithm with cut generation. We use a dual interior point method to warm start the solution of the restricted master problem both after adding columns and after branching. We present numerical results indicating that the proposed approach outperforms the literature on the directed case. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 45(4), 181–192 2005
A simple protocol for deniable authentication based on ElGamal cryptography
Authors: Wang Yingjie , Li Jianhua , Tie Ling
Published: April 2005

Deniable authentication is different from traditional authentication in that the receiver cannot prove the source of a given message to a third party. This article presents a new deniable authentication protocol, based on ElGamal cryptography. The protocol meets the two properties of deniable authentication and can withstand person‐in‐middle (PIM) attacks. Compared with previous schemes, it is simpler and more efficient. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 45(4), 193–194 2005
Efficient neighborhood search for the Probabilistic Pickup and Delivery Travelling Salesman Problem
Authors: Beraldi Patrizia , Ghiani Gianpaolo , Laporte Gilbert , Musmanno Roberto
Published: April 2005

In this article the probabilistic Pickup and Delivery Travelling Salesman Problem is studied and an efficient neighborhood search procedure is developed. This procedure requires O(n3) computations for the evaluation of the neighborhood of a given solution while the straightforward approach has an O(n5)complexity. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 45(4), 195–198 2005
D‐Hillarin, a novel W180‐domain protein, affects cytokinesis through interaction with the septin family member Pnut
Authors: Ji Yun , Rath Uttama , Girton Jack , Johansen Kristen M. , Johansen Jørgen
Published: April 2005

By database searches of the Drosophila genome project we have identified D‐hil as the fly member of a novel family of W180‐domain containing proteins. Immunocytochemistry demonstrated that D‐hil is localized to the neuropil of the embryonic CNS, to the cellular cortex of dividing neuroblasts from larval brains, and that it is up‐regulated in the cleavage furrow of S2 cells. We show that D‐hil distribution overlaps extensively with that of the septin family member Pnut. Cross‐immunoprecipitation experiments further indicated that the two proteins may be members of the same protein complex. Analysis of a severe hypomorphic P‐element mutation in the D‐hil locus suggested that D‐hil is a nonessential protein. However, by creating double mutant flies we show that the D‐hil locus acts as a modulator of Pnut function by increasing the level of polyploidy of neuroblasts in PnutKG00478/PnutKG00478 larval brains. Based on these results we propose that D‐hil may function as a regulator of septin function during cytokinesis in the developing nervous system. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Synaptic thermoprotection in a desert‐dwellingDrosophilaspecies
Authors: Newman Amy E.M. , Xiao Chengfeng , Robertson R. Meldrum
Published: April 2005

Synaptic transmission is a critical mechanism for transferring information from the nervous system to the body. Environmental stress, such as extreme temperature, can disrupt synaptic transmission and result in death. Previous work on larvalDrosophilahas shown that prior heat‐shock exposure protects synaptic transmission against failure during subsequent thermal stress. This induced thermoprotection has been ascribed to an up‐regulation of the inducible heat‐shock protein, Hsp70. However, the mechanisms mediatingnaturalthermoprotection in the wild are unknown. We compared synaptic thermosensitivity betweenD. melanogasterand a desert species,D. arizonae.Synaptic thermosensitivity and the functional limits of the related locomotor behavior differed significantly between closely related, albeit ecologically distinct species. Locomotory behavior of wandering third instarD. arizonaelarvae was less thermosensitive and the upper temperature limit of locomotory function exceeded that ofD. melanogasterby 6°C. Behavioral results corresponded with significantly lower synaptic thermosensitivity at the neuromuscular junction inD. arizonae. Prior heat‐shock protected onlyD. melanogasterby increasing relative excitatory junctional potential (EJP) duration, the time required for EJP failure at 40°C, and the incidence of EJP recovery following heat‐induced failure. Hsp70 induction profiles following heat‐shock demonstrate up‐regulation of inducible Hsp70 inD. melanogasterbut not inD. arizonae. However, expression of Hsp70 under control conditions is greater inD. arizonae. These results suggest that the mechanisms of natural thermoprotection involve an increase in baseline Hsp70 expression. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005