bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Influence of Hydrogen on the Magnetic Properties of LnMn2 and LnFe2 Laves Phase Compounds
Authors: Paul‐Boncour V.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Electronic Spin Crossover
Authors: Guetlich P. , Goodwin H. A.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Inorganic and Organometallic Chemistry of PtIII Complexes Having a Delocalized PtIII—PtIII Bond.
Authors: Matsumoto K.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Metallosupramolecular Chemistry ‐ What Is It?
Authors: Steel Peter J.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Enantioselective Catalysis
Authors: Riant Oliver
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
The P‐Hydroxyphenacyl Photoremovable Protecting Group
Authors: Givens Richard S. , Lee Jong‐Ill
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Azomethine, Carbonyl and Thiocarbonyl Ylides—Generation of Isomunchnones from Metal Carbenoids
Authors: Maier Martin E.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Azomethine, Carbonyl and Thiocarbonyl Ylides—Generation and Intermolecular [3 + 2]‐Cycloaddition of Non‐Stabilized Carbonyl Ylides
Authors: Hosomi Akira , Hojo Makoto , Aihara Hidenori
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Azomethine, Carbonyl and Thiocarbonyl Ylides—Generation of Non‐Stabilized Azomethine Ylides by Decarboxylative Condensation of Aldehydes with N‐Substituted α‐Amino Esters
Authors: Nyerges M. , Toke L.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Commercialization of a Novel Fermentation Concept
Authors: Mazumdar‐Shaw Kiran , Suryanarayan Shrikumar
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Molecular Engineering of Extended Chiral and Enantiopure Multiporphyrinic Architectures: Towards the Control of Their Physicochemical Properties
Authors: Solladie Nathalie , Aubert Nicolas , Gisselbrecht Jean‐Paul , Gross Maurice , Sooambar Chloe , Troiani Vincent
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Polyene Cyclization to Adociasulfate 1
Authors: Lindel Thomas , Hopmann Cordula
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Marine Guanidine Alkaloids and Their Application as Chemical/Biological Tools
Authors: Nagasawa Kazuo , Hashimoto Yuichi
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Short Syntheses of the Spirotryprostatins
Authors: Lindel Thomas
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Heterocyclic Chemistry
Authors: Stockman R. A.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Nitrile Ylides—Generation of Nitrile Ylides by Thermolysis of 1,2,4‐Oxazaphospholines
Authors: Burger Klaus , Fuchs Annett
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Nitrile Ylides—Generation of Nitrile Ylides by the Reaction of Carbenes or Carbenoids with Nitriles
Authors: Ibata Toshikazu , Fukushima Kazuaki
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Ammonium, Oxonium and Sulfonium Ylides—Generation of Sulfonium Ylides by Desilylation of α‐Silyl Sulfonium Salts
Authors: Sato Yoshiro
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis, Reactions, and Selected Physicochemical Properties of 1,3‐ and 1,2‐Tetrachalcogenafulvalenes
Authors: Schukat G. , Fanghaenel E.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Solid Phase Indole Synthesis
Authors: Knepper Kerstin , Ziegert Robert E. , Braese Stefan
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Fascinating Natural and Artificial Cyclopropane Architectures
Authors: Faust Rudiger
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Fullerenes
Authors: Birkett P. R.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Important Calixarene Derivatives : Their Synthesis and Applications
Authors: McHahon Gillian , O'Malley Shane , Nolan Kieran
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Small Organic Molecules for a Highly Enantioselective Direct Aldol Reaction
Authors: Luo Zhi‐Bin , Dai Li‐Xin
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Heterogeneous Asymmetric Catalysis: Mechanisms and Applications
Authors: Carneiro Jose Walkimar de M. , de Oliveira Ceciliana da S. B. , Passos Fabio B. , de Souza Paulo Rogerio N. , Aranda Donato A. , Hernandez‐Valdez Ricardo , Gomes Jr. Marlito , Puzer Luciano , Sabino Silvio Jose , Antunes O. A. C.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Application of Non‐Covalently Solid‐Phase Bound Catalysts
Authors: Michalek F. , Horn J. , Tzschucke C. C. , Bannwarth W.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Pulse Radiolysis Studies of Reaction Kinetics in Ionic Liquids
Authors: Neta P. , Behar D. , Grodkowski J.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Macrocyclic Glycoclusters: From Amphiphiles Through Nanoparticles to Glycoviruses.
Authors: Aoyama Yasuhiro
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Basic Principles for the Production of Fungal Enzymes by Solid‐State Fermentation
Authors: Viniegra‐Gonzalez Gustavo , Favela‐Torres Ernesto
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Generation of a Strong Dipole Layer and Its Function by Using Helical Peptide Molecular Assemblies
Authors: Kimura Shunsaku , Morita Tomoyuki , Kitagawa Kazuya
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Application of Conducting Polymers in Chemical Analysis
Authors: Trojanowicz Marek
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Bizarre Structural, Chemical and Spectral Properties of 4‐Aryl‐3,5‐dihydroxyisoxazoles and Their Derivatives (Disic Acids)
Authors: Zvilichovsky Gury
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Solution NMR Spectroscopy
Authors: Martin Gary E. , Hadden Chad E. , Russell David J.
Published: May 2004

For Abstract see ChemInform Abstract in Full Text.
Probing the Basicity of Regular and Defect Sites of Alkaline Earth Metal Oxide Surfaces by BF3 Adsorption: A Theoretical Analysis
Authors: Di Valentin Cristiana , Locati Corrado , Pacchioni Gianfranco
Published: May 2004

The basicity of regular and low‐coordinate (LC) sites (steps, edges and corners) at the surface of alkaline earths with NaCl structure (MgO, CaO, SrO, and BaO) has been investigated by using BF3 as a probe molecule. BO and BF distances; OBF bond angles; BF asymmetric stretching frequencies; O, B and F 1s core‐level binding energies; and the interaction energy of adsorbed BF3 were determined by means of DFT calculations on cluster models. These adsorption properties were compared with those of complexes of BF3 with molecules with various basicities (water, ammonia, phosphine, etc.). We show that many properties of adsorbed BF3, and in particular the experimentally accessible shifts in vibrational frequency, in B and F 1s core levels, and in BF3 desorption temperature, exhibit a linear correlation with the surface basicity as measured by the vertical ionization potential of the oxide anions. On the other hand, shifts of the O 1s core level binding energy do not provide a simple way to detect surface basicity. On a given oxide surface, the differeing basicities of various sites result in measurable differences in adsorption properties. This suggests the potential use of BF3 as a probe molecule for titrating LC sites on the surface of ionic oxides.
Novel metalloprotease–disintegrin, meltrin ϵ (ADAM35), expressed in epithelial tissues during chick embryogenesis
Authors: Watabe‐Uchida Mitsuko , Masuda Aki , Shimada Naoko , Endo Masateru , Shimamura Kenji , Yasuda Kunio , Sehara‐Fujisawa Atsuko
Published: May 2004

Members of the ADAM (a
disintegrin and metalloprotease) family are involved in fertilization, morphogenesis, and pathogenesis. Their metalloprotease domains mediate limited proteolysis, including ectodomain shedding of membrane‐anchored growth factors and intercellular‐signaling proteins, and their disintegrin domains play regulatory roles in cell adhesion and migration. In screening for cDNAs encoding chicken ADAM proteins expressed during muscle development, we identified Meltrin ϵ as a novel member of this family. To elucidate its functions, we investigated its expression during development by using antibodies raised against its protease domain. In the somites, Meltrin ϵ protein was specifically expressed in the myotomal cells, which delaminate from the dermomyotome to form epithelial sheets. It was also found in the surface ectoderm, lens placodes, otic vesicles, and the gut epithelia. Basolateral localization of Meltrin ϵ in these epithelial cells suggests its unique roles in the organization of the epithelial tissues and development of the sensory organs and the gut. Developmental Dynamics 230:557–568, 2004. © 2004 Wiley‐Liss, Inc.
Laser capture microdissection (LCM) for analysis of gene expression in specific tissues during embryonic epithelial–mesenchymal transformation
Authors: Nawshad A. , LaGamba D. , Olsen B.R. , Hay E.D.
Published: May 2004

The analysis of gene expression in developing organs is a valuable tool for the assessment of genetic fingerprints during the various stages of tissue differentiation and epithelial–mesenchymal transformation (EMT). However, the variety of differentiating cells and the close association of epithelial and mesenchymal cells makes it difficult to extract protein and mRNA from specific cells and tissue and, thus, to assign expressed genes to specific cell populations. We report here the analysis of LEF1 mRNA in epithelial and mesenchymal cells isolated by LCM from different stages of EMT during development of the mouse palate and describe our techniques in detail. By applying a laser capture microdissection (LCM) technique and real‐time polymerase chain reaction, we were able to determine mRNA levels that accurately reflect changes in gene expression in specific cells. The sensitivity of the technique is remarkable. Indeed, the mRNAs can be detected for many proteins too low in abundance to stain with antibodies. These techniques will enable embryologists to collect homogeneous groups of cells from heterogeneous populations in developing organs, which otherwise would not be available for gene analysis. Developmental Dynamics 230:529–534, 2004. © 2004 Wiley‐Liss, Inc.
Down syndrome mouse models Ts65Dn, Ts1Cje, and Ms1Cje/Ts65Dn exhibit variable severity of cerebellar phenotypes
Authors: Olson L.E. , Roper R.J. , Baxter L.L. , Carlson E.J. , Epstein C.J. , Reeves R.H.
Published: May 2004

Two mouse models are widely used for Down syndrome (DS) research. The Ts65Dn mouse carries a small chromosome derived primarily from mouse chromosome 16, causing dosage imbalance for approximately half of human chromosome 21 orthologs. These mice have cerebellar pathology with direct parallels to DS. The Ts1Cje mouse, containing a translocated chromosome 16, is at dosage imbalance for 67% of the genes triplicated in Ts65Dn. We quantified cerebellar volume and granule cell and Purkinje cell density in Ts1Cje. Cerebellar volume was significantly affected to the same degree in Ts1Cje and Ts65Dn, despite that Ts1Cje has fewer triplicated genes. However, dosage imbalance in Ts1Cje had little effect on granule cell and Purkinje cell density. Several mice with dosage imbalance for the segment of the Ts65Dn chromosome not triplicated in Ts1Cje had phenotypes that contrasted with those in Ts1Cje. These observations do not readily differentiate between two prevalent hypotheses for gene action in DS. Developmental Dynamics 230:581–589, 2004. © 2004 Wiley‐Liss, Inc.
Stereochemistry of Caracurine V, iso‐Caracurine V, Bisnortoxiferine, and Tetrahydrocaracurine V Ring Systems
Authors: Zlotos Darius P.
Published: May 2004

The 3D structures of the Strychnos toxifera alkaloids caracurine V and toxiferine I, and of the related iso‐caracurine V and tetrahydrocaracurine V ring systems were determined by means of NMR spectroscopy and semiempirical calculations. The relative spatial arrangement of the aromatic indole rings is similar in all three “caracurine” ring systems. Opening of both tetrahydrooxepine rings of caracurine V to give the bisnortoxiferine ring skeleton leads to the conformational change of the central eight‐membered ring from a crown form to a boat form, resulting in a considerably changed geometry of the whole ring skeleton. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Novel Core Region, Lacking Heptose and Phosphate, of the Lipopolysaccharide from the Gram‐Negative Bacterium Pseudomonascichorii (Pseudomonadaceae RNA Group 1)
Authors: De Castro Cristina , Molinaro Antonio , Nunziata Rosa , Lanzetta Rosa , Parrilli Michelangelo , Holst Otto
Published: May 2004

The extracted lipopolysaccharides (LPSs) fraction of the plant‐pathogenic bacterium Pseudomonas cichorii contained two different molecules, the first of them an LPS possessing an O‐specific polysaccharide made up of four 2‐acetamido‐2,6‐dideoxy sugars linked linearly in a tetrasaccharide repeating unit. The structure of the second LPS component is reported here: it was of the rough form and contained a novel type of core region. The rough form LPS of Ps. cichorii was de‐O‐acylated by mild hydrazinolysis and then de‐N‐acylated with hot 4 M KOH. The oligosaccharide representing the complete carbohydrate backbone of the LPS was isolated by high‐performance anion‐exchange chromatography. Its structural characterization employed compositional and methylation analyses, matrix‐assisted laser desorption/ionisation mass spectrometry and 1H, 13C and 31P NMR spectroscopy, with application of various 1D and 2D experiments. The carbohydrate backbone of this core region consisted of a hexasaccharide that contained no heptoses, being made up of L‐Rhap, D‐GlcpN and D‐GalpN, besides the characteristic α‐(2→4)‐linked 3‐deoxy‐D‐manno‐oct‐2‐ulosonic acid (Kdo) disaccharide. The first Kdo residue linking the core region to the lipid A was substituted by a GalpN residue. This core region thus represents one of the rather few cases in which this position is not substituted by a manno‐configured sugar. The structure of the LPS carbohydrate backbone is shown in Scheme 1. If not stated otherwise, sugars were D‐configured pyranoses. Kdo is 3‐deoxy‐D‐manno‐oct‐2‐ulosonic acid. The lipid A backbone is N‐ and O‐acylated in the LPSs. − Molecular modelling studies of the LPS carbohydrate backbone and of some of its parts were performed, yielding a preferred conformation that was surprisingly inflexible between the two Kdo residues. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Imino Sugar Scaffolds for the Generation of Glycosidase Inhibitor Libraries
Authors: La Ferla Barbara , Bugada Piergiuliano , Cipolla Laura , Peri Francesco , Nicotra Francesco
Published: May 2004

We have synthesized imino sugar scaffolds bearing two points of diversity — the stereocenters located in α positions relative to the nitrogen atom — and three points of orthogonal derivatization — a carboxylic function, the primary hydroxy group, and the ring nitrogen atom. The key steps in the synthetic approach are the chain elongation of aldehyde 5 with the formation of an α,β‐unsaturated ester, the Michael addition of an amine, and the final cyclization. This strategy leads to the preparation of different N‐substituted imino sugar analogues having both α and β structures and of both D and L stereochemistry. Different derivatives have been prepared from the scaffolds we obtained. The carboxymethyl group was coupled to the amino function of different amino acids to afford compounds 30−34, while the selectively accessible primary hydroxy group has been substituted with an azido group to afford compounds 24−26. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Characterisation of the α‐(1→3) Homopolymer of L‐glycero‐D‐manno‐Heptose Units Isolated from the O‐Chain Polysaccharide of Agrobacterium radiobacter
Authors: De Castro Cristina , Sturiale Luisa , Parrilli Michelangelo
Published: May 2004

This paper provides the first report of the molecular primary structure of the O‐chain produced from A. radiobacter group M2−1. The repeating unit was determined, by means of chemical and spectroscopical analyses, to have the following structure: [3)‐α‐L‐glycero‐D‐manno‐heptose‐(1→]n. The relevant feature of this structure is represented by the particular residue involved: L‐glycero‐D‐manno‐heptose. This monosaccharide is almost ubiquitous in Gram‐negative bacteria, but it is exclusively located in the Core region and only in one other case has it is reported as an O‐chain constituent. The knowledge of the chemical structure of the O‐chain of A. radiobacter will be useful for comprehending the bacterium‐host recognition mechanism at the molecular level. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Lewis Acid‐Mediated Diastereoselective Reduction ofN‐Protected β‐Amino Ketones: Influence of the Nature of the Metal Atom and of the Nitrogen Protecting Group
Authors: Bartoli Giuseppe , Bartolacci Massimo , Cortese Manuela , Marcantoni Enrico , Massaccesi Massimo , Pela Roberto , Sambri Letizia
Published: May 2004

Lewis acid‐mediated chelation and non‐chelation control is one of the most fundamental and practical concepts in modern organic chemistry. Extension of these concepts to the reduction of differentN‐protected α‐substituted β‐amino ketones indicated that diastereoselectivity in the hydride addition step is strongly dependent on the nature of the metal atom and on the type of protecting group. Strongly chelating TiCl4and an electron‐rich nitrogen protecting group promoted thesyndiastereoselectivity in noncoordinating solvents (CH2Cl2) at −78 °C with BH3·py as reducing agent. On the other hand, a Lewis acid as such as CeCl3and a bulkyN‐protecting group gave an excess of theanti‐diastereomer in coordinating solvents (THF) at the same temperature with lithium borohydride (LiBH4) as reducing agent. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Glycosylation of Cyclitols: Synthesis of Neamine‐Type Aminoglycosides
Authors: Verhelst Steven H. L. , Magnée Lisette , Wennekes Tom , Wiedenhof Wouter , van der Marel Gijsbert A. , Overkleeft Herman S. , van Boeckel Constant A. A. , van Boom Jacques H.
Published: May 2004

In this paper, a glycosylation‐based approach towards novel aminoglycoside analogues is presented. Three different cyclitol building blocks were condensed with different thioglycosides to give, after removal of the protective groups, several neamine‐type analogs varying in the positioning and the stereochemistry of the amino functions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
An Efficient Ruthenium‐Catalyzed Formal Synthesis of (−)‐Isoavenaciolide
Authors: Labeeuw Olivier , Blanc Delphine , Phansavath Phannarath , Ratovelomanana‐Vidal Virginie , Genêt Jean‐Pierre
Published: May 2004

A formal synthesis of (−)‐isoavenaciolide (1) by two different routes is reported. The first approach, leading to a key precursor 2 of (−)‐isoavenaciolide (1), features the stereoselective construction of the three contiguous stereogenic centers by Evans diastereoselective reduction (d.e. = 80%) of β‐hydroxy ketone 8. In the more efficient second approach, the nine‐step sequence leading to the key precursor 2 involves sequential ruthenium‐catalyzed hydrogenation reactions of β‐keto ester 4 and β‐hydroxy ketone 14 to form the two hydroxyl groups with an excellent control of the anti stereochemistry (d.e. = 99%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Reactivity of a New Nonacarbon Chain Carboxonium Salt − Access to a New Class of Streptocyanine Dyes
Authors: Izquierdo Albert , Guieu Valérie , Gornitzka Heinz , Madaule Yves , Payrastre Corinne
Published: May 2004

A new highly reactive nonacarbon chain carboxonium salt 1 was synthesized. It leads, by action of various amines and hydrazone, to a new class of symmetrical nonacarbon chain streptocyanine dyes 3−5. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Synthesis of a Novel Cyclic Chlorophyll Hetero‐Dyad as a Model Compound for Stacked Chlorophylls Found in Photosynthetic Systems (Eur. J. Org. Chem. 11/2004)
Authors: Kosaka Nobuo , Tamiaki Hitoshi
Published: May 2004

The cover picture shows the molecular structure of a synthetic doubly‐linked cyclic chlorophyll “hetero”‐dyad (left) and its symbolic image using natural leaves (right). Two chlorophyllous κ‐systems are stereospecifically and covalently bonded with two different linkers and close to each other in a nearly parallel fashion. The present synthetic strategy has great potential for the systematic preparation of various cyclic chlorophyll hetero‐dyads. Details of the synthesis and characterization are described in the article by N. Kosaka and H. Tamiaki on p. 2325 ff.
Orthogonal separations of nicotine and nicotine‐related alkaloids by various capillary electrophoretic modes
Authors: Marsh Alex , Clark Brian J. , Altria Kevin D.
Published: May 2004

The migration behaviour of nicotine and related tobacco alkaloids was investigated using three different capillary electrophoretic (CE) modes. Novel separations were achieved both using microemulsion electrokinetic chromatography (MEEKC) and nonaqueous CE (NACE). Improved resolution compared to previous studies was obtained using free‐solution CE (FSCE). Each technique resulted in different, orthogonal separation selectivity. The suitability of each method for application to the analysis of nicotine lozenges is discussed. The FSCE method was applied to the analysis of nicotine lozenges due to its compatibility with an established lozenge extraction solvent. The method used gave good injection precision and linearity. Good agreement of CE and high‐performance liquid chromatography (HPLC) results was obtained. The CE method is therefore considered suitable for the quantitative determination of nicotine in nicotine lozenges.
Genome‐based proteomics
Authors: Agaton Charlotta , Uhlén Mathias , Hober Sophia
Published: May 2004

Protein‐protein interactions play crucial roles in various biological pathways and functions. Therefore, the characterization of protein levels and also the network of interactions within an organism would contribute considerably to the understanding of life. The availability of the human genome sequence has created a range of new possibilities for biomedical research. A crucial challenge is to utilize the genetic information for better understanding of protein distribution and function in normal as well as in pathological biological processes. In this review, we have focused on different platforms used for systematic genome‐based proteome analyses. These technologies are in many ways complementary and should be seen as various ways to elucidate different functions of the proteome.
A split–merge‐based region‐growing method for fMRI activation detection
Authors: Lu Yingli , Jiang Tianzi , Zang Yufeng
Published: May 2004

We introduce a hybrid method for functional magnetic resonance imaging (fMRI) activation detection based on the well‐developed split–merge and region‐growing techniques. The proposed method includes conjoining both of the spatio‐temporal priors inherent in split–merge and the prior information afforded by the hypothesis‐led component of region selection. Compared to the fuzzy c‐means clustering analysis, this method avoids making assumptions about the number of clusters and the computation complexity is reduced markedly. We evaluated the effectiveness of the proposed method in comparison with the general linear model and the fuzzy c‐means clustering method conducted on simulated and in vivo datasets. Experimental results show that our method successfully detected expected activated regions and has advantages over the other two methods. Hum. Brain Mapping 22:271–279, 2004. © 2004 Wiley‐Liss, Inc.
Automatic attention to emotional stimuli: Neural correlates
Authors: Carretié Luis , Hinojosa José A. , Martín‐Loeches Manuel , Mercado Francisco , Tapia Manuel
Published: May 2004

We investigated the capability of emotional and nonemotional visual stimulation to capture automatic attention, an aspect of the interaction between cognitive and emotional processes that has received scant attention from researchers. Event‐related potentials were recorded from 37 subjects using a 60‐electrode array, and were submitted to temporal and spatial principal component analyses to detect and quantify the main components, and to source localization software (LORETA) to determine their spatial origin. Stimuli capturing automatic attention were of three types: emotionally positive, emotionally negative, and nonemotional pictures. Results suggest that initially (P1: 105 msec after stimulus), automatic attention is captured by negative pictures, and not by positive or nonemotional ones. Later (P2: 180 msec), automatic attention remains captured by negative pictures, but also by positive ones. Finally (N2: 240 msec), attention is captured only by positive and nonemotional stimuli. Anatomically, this sequence is characterized by decreasing activation of the visual association cortex (VAC) and by the growing involvement, from dorsal to ventral areas, of the anterior cingulate cortex (ACC). Analyses suggest that the ACC and not the VAC is responsible for experimental effects described above. Intensity, latency, and location of neural activity related to automatic attention thus depend clearly on the stimulus emotional content and on its associated biological importance. Hum. Brain Mapp. 22:290–299, 2004. © 2004 Wiley‐Liss, Inc.
Lipomatous hemangiopericytoma of the head and neck: immunohistochemical and dna ploidy analyses
Authors: Alrawi Sadir J. , Deeb George , Cheney Richard , Wallace Paul , Loree Thom , Rigual Nestor , Hicks Wesley , Tan Dongfeng
Published: May 2004

Background.

Lipomatous hemangiopericytoma (LHPC) is a newly described rare soft tissue tumor with unpredictable biologic behavior and is difficult to diagnose by conventional histologic parameters. The molecular analyses of this entity to date are sparse. Only a few cases of LHPC have been reported. Although one case of LHPC in the sinonasal region was briefly reported, this is the first case in the head and neck region with detailed clinicopathologic features and molecular analysis of this entity.

Methods.

We reported a case of LHPC in a 55‐year‐old woman with a slowly growing lesion in the occipital area that was diagnosed by CT and MRI and removed surgically. Immunohistochemical and DNA ploidy analyses were performed.

Results.

A panel of 16 markers was included for immunohistochemical analysis. Diffuse immunopositivity of CD57 in our case provides supportive evidence that LHPC is linked with HPC because this marker is also present in approximately 50% of conventional HPCs. CD57 should be used in the immunohistochemical panel in any lesion suspected to be LHPC. Furthermore, CD57 along with CD34 and XIIIa is thought to stain for primitive mesenchymal stem cells, suggesting a bimodal/multimodal differentiation of LHPC. By flow cytometry, we found that tumor cells were 100% diploid with the S‐phase fraction (SPF) being 3.21%. A significant positive correlation was detected between nuclear proliferating index and SPF (p < 0.001, by Spearman analysis). These findings provide molecular evidence indicating a benign nature of LHPC.

Conclusions.

Contrary to the old belief that HPC has an aggressive nature, this variant of tumor looks less aggressive. The patient was followed for 1 year without any evidence of recurrence, supporting our pathologic hypothesis. © 2004 Wiley Periodicals, Inc. Head Neck 26: 544–549, 2004
Prevalence of LMP‐1 gene in tonsils and non‐neoplastic nasopharynxes by nest‐polymerase chain reaction in Taiwan
Authors: Pai Ping‐Ching , Tsang Ngan‐Ming , Tseng Chen‐Kan , Hao Sheng‐Po , Kuo Tseng‐Tong , Wei Kuo‐Chen , Hsueh Chuen , Chuang Chi‐Cheng
Published: May 2004

Background.

The purpose of this study was to investigate the frequency of Epstein‐Barr virus (EBV) latent membrane protein‐1 (LMP‐1) in tonsils and non‐neoplastic nasopharynxes in Taiwan.

Methods.

Nest‐polymerase chain reaction (nest‐PCR) was used to examine the presence of LMP‐1 gene in lymphoid hyperplasia from non‐neoplastic tonsillar and nasopharyngeal tissues and in tonsillar cancers.

Results.

In 152 cases, 64 biopsy tissues were obtained from lymphoid hyperplasia of nasopharynxes, 57 from tonsillectomy of non‐neoplastic tonsils, and 31 from tonsillar cancers. LMP‐1 was detected in 43.4% of the study group. Nineteen (29.7%) and 29 (50.9%) lymphoid hyperplasias from normal nasopharynxes and tonsils, respectively, and 18 (58.1%) biopsies from tonsillar cancers had positive LMP‐1. The 30–base pair (bp) deleted variant was detected in 89.5% and 82.8% of normal nasopharynxes and tonsils, respectively, and in 66.7% of biopsies from tonsillar cancers (p = .198).

Conclusion.

This study found that the 30‐bp variant was the predominant type of LMP‐1 from a healthy population in Taiwan. © 2004 Wiley Periodicals, Inc. Head Neck 26: 619–624, 2004
Combined evaluation of expression of telomerase, survivin, and anti‐apoptotic bcl‐2 family members in relation to loss of differentiation and apoptosis in human head and neck cancers
Authors: Sharma Himani , Sen Sudip , Mathur Meera , Bahadur Sudhir , Singh Neeta
Published: May 2004

Background.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers, and it accounts for 5% of all adult cancers worldwide. Loss of growth control and a marked resistance to apoptosis are considered major mechanisms driving tumor progression. Little is known about the distribution of inhibitors of apoptosis in HNSCC or how they correlate with other biomarkers of malignancy, such as telomerase, an enzyme that plays a critical role in cellular immortalization. The objective of this study was to assess the protein expression of anti‐apoptotic members of Bcl‐2 family and survivin and correlate them with telomerase activity.

Methods.

We compared anti‐apoptotic protein expression in tumor tissue sections of 50 HNSCC patients and 19 histopathologically normal tissues by immunohistochemistry and Western blotting. Apoptotic index was studied by TUNEL assay. Telomerase activity was determined by polymerase chain reaction (PCR)–enzyme‐linked immunosorbent assay (ELISA).

Results.

Bcl‐2, Bcl‐XL, and survivin were found to be significantly upregulated in tumor tissues as compared with the normal tissue. Protein expression of Bcl‐2 and survivin was significantly associated with the loss of differentiation in tumors and that of Bcl‐XL with nodal metastasis. Telomerase activity was found to be upregulated in tumors as compared with the normal tissue (p < .001) and was found to be significantly associated with the loss of differentiation in tumors.

Conclusions.

Mechanisms that promote both cell proliferation (telomerase activity) and cell survival (expression of inhibitors of apoptosis protein [IAPs]) appear to be activated in HNSCC. This is the first study of its kind to look into the correlation of the apoptotic pathway and proliferation promoting enzyme activity simultaneously in relation to loss of apoptosis and differentiation in HNSCCs. Telomerase activity in these tumors was found to be correlated with Bcl‐2, Bcl‐XL, and survivin overexpression and with reduced apoptosis, thereby suggesting that novel strategies can be developed to control cancer cell growth by co‐targeting telomerase and apoptotic pathways. © 2004 Wiley Periodicals, Inc. Head Neck 26: 733–740, 2004
A two‐component hydrograph separation for three high‐elevation catchments in the Sierra Nevada, California
Authors: Huth A. K. , Leydecker A. , Sickman J. O. , Bales R. C.
Published: May 2004

Two‐component hydrograph separations were performed for three, nested, snowmelt‐dominated catchments in Sequoia National Park. The purpose of the hydrograph separations was to: (i) differentiate between the old and new water contributions to discharge during snowmelt using δ18O signatures; (ii) identify the fraction of snowmelt that travelled through the subsurface (reactive) compartment during the snowmelt period using silica or sodium; and (iii) investigate the impact of changing end‐member signatures on the separations. ‘Old’ water refers to water that was stored in the watershed during the previous year, whereas ‘new’ water is current snowmelt. Hydrograph separations were performed for both a high‐accumulation (1998, annual precipitation 2·4 m) and an average year (1999, 1·3 m). The proportion of old water contribution to discharge during the rising limb of the hydrograph was 10–20%, with 80–100% of snowmelt being reactive, i.e. passing through soil and talus. Estimates of old and new soil water and direct snowmelt entering the stream varied among the catchments in 1999. Differences between these components were minimal in 1998, regardless of varying topography and differing proportions of soil, rock and talus. Using time‐dependent rather than constant δ18O meltwater and silica soil‐water signatures made a meaningful impact on both new and old water, and reactive and unreactive, estimates. Copyright © 2004 John Wiley & Sons, Ltd.
Groundwater flow in anisotropic aquifers reduced to the isotropic case
Authors: Faraoni Valerio
Published: May 2004

By applying the technique of conformal transformation of the metric, widely used in general relativity and cosmology, the analysis of groundwater flow in an anisotropic aquifer (in which the hydraulic conductivity is a tensor) is reduced to the case of an isotropic one. This reduction is achieved for a particular conformal factor of the transformation. Examples of application of this technique are given. Copyright © 2004 John Wiley & Sons, Ltd.
Temporal and spatial variability of cation and silica export in an alpine watershed, Emerald Lake, California
Authors: Meixner T. , Shaw J. R. , Bales R. C.
Published: May 2004

A reaction set of possible mineral weathering reactions is proposed to explain observed cation and silica export for the Emerald Lake watershed, a small Sierra Nevada, California catchment. The reaction set was calculated through a stoichiometric mole‐balance method, using a multiyear record of stream flow and snowpack chemical analyses and site‐specific mineral compositions. Reaction‐set calculations were intended to explore how the processes controlling stream cation and silica export depend on differing bedrock mineralogy across the catchment as snowmelt and runoff patterns change over the year. Different regions within the watershed can be differentiated by lake inflow subdrainages, each exhibiting different stream‐flow chemistry and calculated weathering stoichiometry, indicating that different silica and cation generation processes are dominant in wet steep portions of the catchment. Short‐term differences in stream concentrations were assumed to reflect ion exchange equilibria and rapid biological processes, whereas long‐term persistent stream concentration differences in different areas of the catchment were assumed to reflect spatial variability in mineral weathering stoichiometry. Mineralogical analyses of rock samples from the watershed provided site‐specific chemical compositions of major mineral species for reaction calculations. Reaction sets were evaluated by linear regression of calculated versus observed differences between snowmelt and stream‐flow chemistry and by a combined measure. Initially, single weathering reactions were balanced and evaluated to determine the reactions that best explained observed stream chemical export. Next, reactions were combined, using mineral compositions from different rock types to estimate the dependence of ion fluxes on lithology. The seasonal variability of major solute calculated fluxes is low, approximately one order of magnitude, relative to the observed three orders of magnitude variability in basin discharge. Reaction sets using basin‐averaged lithology and Aplite lithologies gave superior explanations of stream chemical composition. Copyright © 2004 John Wiley & Sons, Ltd.
A digital elevation analysis: a spatially distributed flow apportioning algorithm
Authors: Kim Sanghyun , Lee Haksu
Published: May 2004

An integrated flow determination algorithm is proposed to calculate the spatial distribution of the topographic index to the channel network. The advantages of a single flow direction algorithm and other multiple flow direction schemes are selectively considered in order to address the drawbacks of existing algorithms. A spatially varying flow apportioning factor is introduced to distribute the contributing area from upslope cells to downslope cells. The channel initiation threshold concept is expanded and integrated into a spatially distributed flow apportioning algorithm to delineate a realistic channel network. The functional relationships between the flow apportioning factors and the expanded channel initiation threshold (ECIT) are developed to address the spatially varied flow distribution patterns considering the permanent channel locations. A genetic algorithm (GA) is integrated into the spatially distributed flow apportioning algorithm (SDFAA) with the objective function of river cell evaluation. An application of a field example suggests that the spatially distributed flow apportioning scheme provides several advantages over the existing approaches; the advantages include the relaxation of overdissipation problems near channel cells, the connectivity feature of river cells and the robustness of the parameter determination procedure over existing algorithms. Copyright © 2004 John Wiley & Sons, Ltd.
Observations on the movement of coarse gravel using implanted motion‐sensing radio transmitters
Authors: McNamara James P , Borden Carter
Published: May 2004

Motion‐sensing radio transmitters were implanted in cobbles (72–92 mm diameter) and placed in a stream in south‐west Idaho for 43 days during a snowmelt period. The radios transmit different pulse rates depending on whether the rocks are at rest or in motion. Every 30 s, a datalogger samples the receiver and records the pulse rate of the transmitters. Such information can be used to assess numerous properties of particle transport that are beyond the capabilities of conventional tracking methods. Conclusions include: (i) rocks are more likely to move on rising hydrograph limbs than on falling hydrograph limbs; (ii) the average Shields' parameter is 0·046; (iii) rocks move only a fraction of the time between initial and final motion during an event; (iv) the distributions of motion and rest periods are best modeled by gamma functions rather than exponential, but the distributions approach exponential as the tails are trimmed. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrological responses to conservation practices in a catchment of the Loess Plateau, China
Authors: Huang Mingbin , Zhang Lu
Published: May 2004

Since the late 1950s a series of soil conservation practices have been implemented in the Loess Plateau. It is important to assess the impact of these practices on hydrology at the catchment scale. The Jialuhe River catchment, a tributary of the Yellow River, with a drainage area of 1117 km2 in the Loess Plateau, was chosen to investigate the hydrological responses to conservation practices. Parametric and non‐parametric Mann–Kendall tests were utilized to detect trends in hydrological variables or their residuals. Relationships between precipitation and hydrological variables were developed to remove the impact of precipitation variability. Significant linear decreasing trends in annual surface runoff and baseflow were identified during the treated period from 1967 to 1989, and the rate of reduction was 1·30 and 0·48 mm/year, respectively. As result, mean annual surface runoff and baseflow decreased by 32% over the period of 1967 to 1989. Seasonal runoff also decreased during the treated period with the greatest reduction occurring in summer and the smallest reduction in winter. The response of high and low daily flow to conservation practices was greater than average flows. Copyright © 2004 John Wiley & Sons, Ltd.
Displacement and transport of marked pebbles, cobbles and boulders during floods in a steep mountain stream
Authors: Lenzi Mario Aristide
Published: May 2004

In a small experimental catchment of the Dolomites (Rio Cordon, 5 km2) field observations have been carried out on the movement of various sized bed material particles. Displacement length of 860 marked pebbles, cobbles and boulders (0·032 < D < 0·512 m) has been measured along the river bed during individual snowmelt and flood events in the periods 1993–1994 and 1996–1998. Floods were grouped into two categories. The first includes ‘ordinary’ events, which are characterized by peak discharges with a return period of 1–5 years and by an hourly bedload rate not exceeding 20 m3 h−1. The second refers to ‘exceptional’ events with a return period of 50–60 years. A flood of this latter type occurred on 14 September 1994, with a peak discharge of 10·4 m3 s−1 and average hourly bedload rate of 324 m3 h−1. The variation according to grain size of total displacement length Li depends on the degree of mobilization of the individual fractions of the bed surface: Li is independent of Di for smaller, fully mobile grain sizes and decreases rapidly with Di for larger fractions in a state of partial transport. Sustained selective transport without a supply of sediment from upstream leads to the development of a stable coarse armoured surface through progressive winnowing of finer material from the bed surface. With supply unlimited conditions for transport, both the occurrence of extreme events and the duration of a sequences of ‘ordinary’ floods play an important role in the degree of mobilization of the individual fractions of the bed. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating river discharge from very high‐resolution satellite data: a case study in the Yangtze River, China
Authors: Xu Kaiqin , Zhang Jiqun , Watanabe Masataka , Sun Chunpeng
Published: May 2004

The measurement of river discharge is necessary for understanding many water‐related issues. Traditionally, river discharge is estimated by measuring water stage and converting the measurement to discharge by using a stage–discharge rating curve. Our proposed method for the first time couples the measurement of water‐surface width with river width–stage and stage–discharge rating curves by using very high‐resolution satellite data. We used it to estimate the discharge in the Yangtze (Changjiang) River as a case study. The discharges estimated at four stations from five QuickBird‐2 images matched the ground observation data very well, demonstrating that the proposed approach can be regarded as ancillary to traditional field measurement methods or other remote methods to estimate river discharge. Copyright © 2004 John Wiley & Sons, Ltd.
Long‐term carbon storage and hydrological control of CO2 exchange in tundra ponds in the Hudson Bay Lowland
Authors: Macrae M. L. , Bello R. L. , Molot L. A.
Published: May 2004

Carbon dioxide fluxes and water balance were examined in 43 tundra ponds in the northern portion of the Hudson Bay Lowland near Churchill, Manitoba. Most of the ponds were hydrologically disconnected from their catchments during dry periods throughout the post‐melt season. However, episodic reconnection occurred following large precipitation events where depression storage was exceeded. Significant shifts in pond chemistry were observed following precipitation events, with the degree of CO2 saturation increasing during these periods. Pond CO2 concentrations rapidly fell to pre‐event levels following events, suggesting that hydrological connectivity can affect the magnitude and direction of CO2 gas fluxes in tundra ponds. Atmospheric CO2 invaded ponds with highly organic sediments for most of the summer, suggesting that terrestrially derived inorganic carbon was insufficient to meet the demands of algal net production. In contrast, ponds with highly mineral sediments continued to evade CO2 during the summer. In a subset of 11 ponds, long‐term rates of carbon accumulation in sediment ranged from 0·6 to 2·2 mol C m−2 year−1. Very strong correlations existed between average sediment accumulation rates and pond perimeters and basin areas suggesting that peat may be a major source of sediment carbon. Aeolian transport is also a potentially large source of sediment carbon. Copyright © 2004 John Wiley & Sons, Ltd.
Introduction to the special issue
Authors: Collins Frank L. , Kaslow Nadine J. , Illfelder‐Kaye Joyce
Published: May 2004

This special issue is a collection of seven articles from the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology. The articles include an executive summary that provides a broad overview of the conference organization and a summary of the themes that emerged from the six working groups. The workgroups included in this series focused on: (a) Scientific Foundations, (b) Psychological Assessment, (c) Intervention, (d) Individual and Cultural Diversity, (e) Supervision, and (f) Consultation and Interprofessional Collaboration. These article represent one outcome of this conference. Additional articles will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Becoming a competent clinician: Basic competencies in intervention
Authors: Spruill Jean , Rozensky Ronald H. , Stigall Tommy T. , Vasquez Melba , Bingham Rosie Phillips , Olvey Cindy De Vaney
Published: May 2004

This article summarizes the results from the Intervention Work Group of the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology. The generic charge presented to the Intervention Work Group was “to address issues related to interventions.” The Intervention Work Group identified four competency components of knowledge, skills, and abilities: (a) foundational competencies; (b) intervention planning; (c) intervention implementation; and (d) intervention evaluation competencies. A fifth component that included “practice management” was labeled as “others.” Each component is discussed, including competencies that were deemed an essential knowledge, skill, and/or value. A discussion of training for intervention competence and assessing that intervention competence is included. Future directions for the science and practice of psychology in the intervention arena are summarized. This is one of a series of articles published in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.