bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry of lipopolysaccharide species separated by slab‐polyacrylamide gel electrophoresis: High‐resolution separation and molecular weight determination of lipooligosaccharides from Vibrio fischeri strain HMK
Authors: Pupo Elder , Phillips Nancy J. , Gibson Bradford W. , Apicella Michael A. , Hardy Eugenio 
Published: July 2004

AbstractWe recently demonstrated that the combined use of lipopolysaccharide (LPS) reverse staining and high‐efficiency passive elution techniques can be successfully used as a suitable interface between LPS slab‐gel separation and electrospray ionization‐mass spectrometry (ESI‐MS) of LPS‐derived oligosaccharides. Here, we extend our micropurification strategy for the analysis of O‐deacylated LPS forms from Vibrio fischeri HMK after recovery from single reverse‐stained LPS bands using matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS). The quantities (30–40 μg) obtained from the two gel‐resolved LPS bands were sufficient to allow MALDI‐TOF‐MS detection of O‐deacylated LPS glycoforms at m/z 3767.1, 3890.1 for the high‐molecular‐weight or at m/z 2522.5, 2645.4, 2725.7, and 2848.7 for the low‐molecular‐weight LPS band. These LPS band heterogeneities resulted not only from variations in the oligosaccharide region of the LPS but also from two phosphorylation states of the lipid A (diphosphoryl and diphosphoryl plus a single phosphoethanolamine substitution). On the other hand, MALDI‐TOF mass spectra of the separated LPS bands displayed reduced heterogeneity and increased signal‐to‐noise ratios as compared to spectra of the unpurified LPS. Furthermore, micropurification of LPS bands prior MALDI‐TOF‐MS led to a higher sensitivity of detection of less abundant low‐molecular‐weight LPS glycoforms. Taken together, this and our previous study on gel‐micropurified LPS using ESI definitively show how one can unambiguously determine the different molecular species contained within each gel‐separated LPS band, their relative abundance and oligosaccharide sequences.
Spontaneous mutant frequency and mutation spectrum for gene A of ΦX174 grown in E. coli
Authors: Raney Jessica L. , Delongchamp Robert R. , Valentine Carrie R. 
Published: July 2004

AbstractThe use of transgenic targets for measuring mutant frequencies in mammalian tissue requires an estimate of the mutant frequency that results from recovery of the transgene in bacterial recovery systems. In this study, we have determined the spontaneous mutant frequency, estimated the mutation rate, and ascertained the mutation spectrum for gene A of ΦX174 grown in E. coli strain CQ2 from 156 small independent cultures. The mutant frequency of 12 of the 156 cultures was 17 ± 1.0 × 10−6 and the estimated mutation rate per gene replication was 7.4 ± 2.3 × 10−6. The mutant frequency and spectrum from E. coli were not significantly different from that of solvent‐treated embryonic mouse cells in culture, 19 ± 0.5 × 10−6 (Valentine CR et al. [2002]: Environ Mol Mutagen 39:55–68), indicating that those spontaneous mutants were primarily derived from E. coli. The E. coli spectrum was heavily weighted toward two major target sites (hot spots), 4225A→G (56%) and 4218G→A or C (20%). Four new target sites and one new mutational event were recovered by the gene A forward assay. A mutant spectrum from an expanded phage stock was also determined to assess the effects of propagating the virus. This mutant frequency was higher (6 × 10−4), contained more double mutants (15% compared to 0.6%), and had a significantly different spectrum from the spectrum for independent cultures (fewer A:T→G:C and G:C→C:G changes and more G:C→A:T; P < 0.002). The E. coli mutation spectrum will be useful for determining the origin of gene A mutation in tissues of ΦX174 transgenic mice. Environ. Mol. Mutagen. 44:119–127, 2004. Published 2004 Wiley‐Liss, Inc.
Long‐term growth of a valley‐bottom gully, western Iowa
Authors: Thomas John T. , Iverson Neal R. , Burkart Michael R. , Kramer Larry A. 
Published: July 2004

AbstractGrowth of a permanent, valley‐bottom gully from 1964 to 2000 was determined annually from survey and sediment‐discharge data and compared with runoff and baseﬂow discharges. Data were analysed to test the hypothesis that rates of gully growth decay exponentially with time in response to shrinking catchment area caused by gully enlargement. Also, monthly values of growth rates and runoff, averaged over the 36‐year record, were analysed with mass‐wasting data to determine the extent to which colluvium availability affected growth rates seasonally.From 1964 to 2000, the gully volume increased by 9200 m3, accounting for 34 per cent of sediment yield from the watershed. There were tight power‐law relationships between annual growth rates and annual runoff, with runoff exponents of 1·57 and 1·30 for headward and volumetric growth, respectively. Increases in gully length, area, and volume were ﬁtted successfully assuming an exponential decay in growth rate with time. Rather than being due to a decrease in catchment area, however, the decline in growth rate was caused by a 77 per cent decrease in the ratio of runoff to baseﬂow, which also widened the gully and reduced the mean slope of its banks. Order‐of‐magnitude seasonal changes in erosion efﬁciency, deﬁned as the fraction of stream power used to evacuate sediment from the gully, were roughly correlated with colluvium availability, as indicated by seasonal changes in the number of bank mass‐wasting events. No more than 2·2 per cent of stream power was used to evacuate sediment during any month. This study demonstrates the danger of attributing declining rates of gully growth to a shrinking catchment area if corroborative runoff and baseﬂow data are not available. Moreover, it illustrates that stream power alone provides only a rough and physically indirect measure of erosion potential. Copyright © 2004 John Wiley & Sons, Ltd.
Parallel adaptive refinement for unsteady flow calculations on 3D unstructured grids
Authors: Waltz Jacob 
Published: July 2004

AbstractA parallel adaptive refinement algorithm for three‐dimensional unstructured grids is presented. The algorithm is based on an hierarchical h‐refinement/derefinement scheme for tetrahedral elements.The algorithm has been fully parallelized for shared‐memory platforms via a domain decomposition of the mesh at the algebraic level. The effectiveness of the procedure is demonstrated with applications which involve unsteady compressible fluid flow. A parallel speedup study of the algorithm also is included. Published in 2004 by John Wiley & Sons, Ltd.
Least‐squares meshfree method for incompressible Navier–Stokes problems
Authors: Zhang Xiang Kun , Kwon Kie‐Chan , Youn Sung‐Kie 
Published: July 2004

AbstractA least‐squares meshfree method based on the first‐order velocity–pressure–vorticity formulation for two‐dimensional incompressible Navier–Stokes problem is presented. The convective term is linearized by successive substitution or Newton's method. The discretization of all governing equations is implemented by the least‐squares method. Equal‐order moving least‐squares approximation is employed with Gauss quadrature in the background cells. The boundary conditions are enforced by the penalty method. The matrix‐free element‐by‐element Jacobi preconditioned conjugate method is applied to solve the discretized linear systems. Cavity flow for steady Navier–Stokes problem and the flow over a square obstacle for time‐dependent Navier–Stokes problem are investigated for the presented least‐squares meshfree method. The effects of inaccurate integration on the accuracy of the solution are investigated. Copyright © 2004 John Wiley & Sons, Ltd.
Folate modulates Hox gene‐controlled skeletal phenotypes
Authors: Kappen Claudia , Mello Maria Alice , Finnell Richard H. , Salbaum J. Michael 
Published: July 2004

AbstractHox genes are well‐known regulators of pattern formation and cell differentiation in the developing vertebrate skeleton. Although skeletal variations are not uncommon in humans few mutations in human HOX genes have been described. If such mutations are compatible with life, there may be physiological modifiers for the manifestation of Hox gene‐controlled phenotypes, masking underlying mutations. Here we present evidence that the essential nutrient folate modulates genetically induced skeletal defects in Hoxd4 transgenic mice. We also show that chondrocytes require folate for growth and differentiation and that they express folate transport genes, providing evidence for a direct effect of folate on skeletal cells. To our knowledge, this is the first report of nutritional influence on Hox gene‐controlled phenotypes, and implicates gene–environment interactions as important modifiers of Hox gene function. Taken together, our results demonstrate a beneficial effect of folate on skeletal development that may also be relevant to disorders and variations of the human skeleton. genesis 39:155–166, 2004. © 2004 Wiley‐Liss, Inc.
Inner hair cell Cre‐expressing transgenic mouse
Authors: Li Mingyuan , Tian Yong , Fritzsch Bernd , Gao Jiangang , Wu Xudong , Zuo Jian 
Published: July 2004

AbstractCochlear hair cells of the inner ear are mechanosensory transducers critical for sound reception in mammals. A mouse with a specific expression of Cre recombinase activity in hair cells is essential for hair cell‐specific gene targeting. Here we report a transgenic mouse in which Cre activity is detected in inner hair cells, not in supporting cells, in the cochlea. The Cre activity was visualized with both X‐gal staining and β‐galactosidase immunostaining in progeny of a cross between our Cre line and the reporter ROSA26R line. In inner hair cells, the Cre activity started at postnatal day 14 and was maintained throughout adulthood. Starting at postnatal day 50, a few outer hair cells in the outermost row of cochlear apical and middle turns displayed the Cre activity. In vestibular hair cells and spiral ganglia, the Cre activity was also detected. Cre activity was present in cells widely distributed throughout brain, testis, and retina, but was absent in many other tissues such as kidney, heart, liver, and intestine. This Cre mouse line can thus be used for conditional gene targeting in mature inner hair cells of the cochlea. genesis 39:173–177, 2004. © 2004 Wiley‐Liss, Inc.
Tissue‐specific and inducible Cre‐mediated recombination in the gut epithelium
Authors: El Marjou Fatima , Janssen Klaus‐Peter , Hung‐Junn Chang Benny , Li Mei , Hindie Valérie , Chan Lawrence , Louvard Daniel , Chambon Pierre , Metzger Daniel , Robine Sylvie 
Published: July 2004

AbstractWe generated two complementary systems for Cre‐mediated recombination of target genes in the mouse digestive epithelium and tested them with a Cre‐reporter mouse strain. Cre was expressed under the control of a 9 kb regulatory region of the murine villin gene (vil‐Cre). Genetic recombination was initiated at embryonic day (E) 9 in the visceral endoderm, and by E12.5 in the entire intestinal epithelium, but not in other tissues. Cre expression was maintained throughout adulthood. Furthermore, transgenic mice bearing a tamoxifen‐dependent Cre recombinase (vil‐Cre‐ERT2) expressed under the control of the villin promoter were created to perform targeted spatiotemporally controlled somatic recombination. After tamoxifen treatment, recombination was detectable throughout the digestive epithelium. The recombined locus persisted for 60 days after tamoxifen administration, despite rapid intestinal cell renewal, indicating that epithelial progenitor cells had been targeted. The villin‐Cre and villin‐Cre‐ERT2 mice provide valuable tools for studies of cell lineage allocation and gene function in the developing and adult intestine. genesis 39:186–193, 2004. © 2004 Wiley‐Liss, Inc.
Thyrocyte‐specific expression of Cre recombinase in transgenic mice
Authors: Kusakabe Takashi , Kawaguchi Akio , Kawaguchi Rumi , Feigenbaum Lionel , Kimura Shioko 
Published: July 2004

AbstractA transgenic mouse line that expresses Cre recombinase under control of the human thyroid peroxidase (TPO) gene promoter was established. The activity and specificity of the TPO‐driven Cre recombinase were examined by using Northern blotting and by crossing with the ROSA26 reporter transgenic mouse line. In the latter mice, Cre‐mediated recombination occurred only in the thyrocytes, and recombination commenced around embryonic day 14.5, at the time during thyroid organogenesis when TPO expression begins. This study demonstrates that the TPO‐Cre transgenic mouse is a powerful tool to specifically delete loxP‐inserted (floxed) genes in thyrocytes and will be of great value in the study of thyrocyte‐specific genes during development and/or in adult thyroids. genesis 39:212–216, 2004. © 2004 Wiley‐Liss, Inc.
Germline transmission and efficient DNA recombination in mouse embryonic stem cells mediated by adenoviral‐Cre transduction
Authors: Shui Jr‐Wen , Tan Tse‐Hua 
Published: July 2004

AbstractFollowing gene targeting, a loxP‐neo‐loxP cassette was introduced into ES cells. The presence of a selectable marker such as neo in the targeted allele may result in gene interference in flox mice or unexpected phenotypes due to genetic ambiguity in direct knockout mice. Typically, the neo cassette is selectively removed by transient expression of the Cre recombinase in targeted ES cell. However, this method involves a tedious process of selecting, expanding, and screening ES cell clones which may compromise germline competency. Here, we describe a novel method of combining adenovirus‐Cre mediated gene recombination with ES gene targeting to facilitate efficient loxP‐neo‐loxP removal in ES cells. We demonstrate that adenovirus‐Cre infected ES cells can retain their germline competency. The procedures described here facilitate a rapid genetic manipulation of ES cells to obtain neo‐free knockout animals, multiple gene targeting, homozygous mutant ES cells ideal for in vitro characterization, or Rag‐deficient blastocyst complementation. genesis 39:217–223, 2004. © 2004 Wiley‐Liss, Inc.
Water resources hazard management system: spatial extension for the assessment of sustainable water use practices in Kenya
Authors: Ochola W. O. , Kerkides P. , Argyrokastritis I. , Kollias V. 
Published: July 2004

AbstractWater resources attributes can be parameterized into water quality indicators that also describe the impact of agriculture on the biophysical and socio‐economic processes in the environment. This article is a sequel to a previous paper published by the authors that presented a water resources hazard assessment decision support system (DSS). The geographical information system (GIS) functionality of the original DSS has been advanced for mapping, spatial and geostatistical analysis of water resources hazards, water use/management practice classification and best water management practice identification. The interactive mapping potential enables the users to broaden water resource management and investigate spatial and temporal trends in water hazard status. The output includes a host of thematic maps and water use matrices. The improvement of the DSS by integration of GIS has enhanced its ability to support land and water use decision‐making at farm and catchment levels by not only setting best water use guidelines but also suggesting where they are most appropriate. The improved version of the DSS has been recalibrated, tested and applied to land and water use data from the Kusa area in Kenya. The system assists land and water use planning through the evaluation of sustainability of water resources, identifying environmental issues concerning future water use sites and defining the conditions for use of present water resources. It can be used to evaluate hazards and environmental threats to other agricultural land resources. The current paper presents a documentation of the water hazard management system and a description of its application to be a requisite of water hazards in the study area. Copyright © 2004 John Wiley & Sons, Ltd.
A biomolecular force field based on the free enthalpy of hydration and solvation: The GROMOS force‐field parameter sets 53A5 and 53A6
Authors: Oostenbrink Chris , Villa Alessandra , Mark Alan E. , Van Gunsteren Wilfred F. 
Published: July 2004

AbstractSuccessive parameterizations of the GROMOS force field have been used successfully to simulate biomolecular systems over a long period of time. The continuing expansion of computational power with time makes it possible to compute ever more properties for an increasing variety of molecular systems with greater precision. This has led to recurrent parameterizations of the GROMOS force field all aimed at achieving better agreement with experimental data. Here we report the results of the latest, extensive reparameterization of the GROMOS force field. In contrast to the parameterization of other biomolecular force fields, this parameterization of the GROMOS force field is based primarily on reproducing the free enthalpies of hydration and apolar solvation for a range of compounds. This approach was chosen because the relative free enthalpy of solvation between polar and apolar environments is a key property in many biomolecular processes of interest, such as protein folding, biomolecular association, membrane formation, and transport over membranes. The newest parameter sets, 53A5 and 53A6, were optimized by first fitting to reproduce the thermodynamic properties of pure liquids of a range of small polar molecules and the solvation free enthalpies of amino acid analogs in cyclohexane (53A5). The partial charges were then adjusted to reproduce the hydration free enthalpies in water (53A6). Both parameter sets are fully documented, and the differences between these and previous parameter sets are discussed. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1656–1676, 2004
A history of Combined‐Integrated doctoral training in psychology
Authors: Beutler Larry E. , Givner Abraham , Mowder Barbara A. , Fisher Daniel , Reeve Ronald E. 
Published: July 2004

AbstractThe history of doctoral training in psychology is reviewed, with special emphasis on the development of training models for applied psychology. Among applied psychology doctoral programs, most label themselves as being one of the three currently recognized practice areas: clinical, counseling, and school psychology; however, since the 1970s, APA also has accredited “combined” programs. The history of the development of the combined model is traced, including information from the programs themselves about the manner in which each evolved. Recently, new interest in the combined category —or Combined‐Integrated (C‐I) as these programs wish to become known—has emerged, and an organization representing these programs has formed. The C‐I model is described, and the potential that the model may serve as a template for the future of professional training in psychology is discussed. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Synthesis of 2H‐ and 3H‐labelled iptakalim hydrochloride
Authors: Zhang Cheng , Yang Rifang , Chen Lanfu , Zhong Bohua , Yun Liuhong , Wang Hai 
Published: July 2004

AbstractIptakalim hydrochloride (N‐(1‐methylethyl)‐1,1,2‐trimethyl‐propylamine hydrochloride) is a promising antihypertensive drug discovered and developed by Beijing Institute of Pharmacology and Toxicology. Deuterium‐ and tritium‐labelled compounds were designed and synthesized for pharmacokinetic and pharmacological mechanism studies. A derivatization method has been employed in the synthesis procedure. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis, radiosynthesis and preliminary in vivo evaluation of [123I]‐(4‐fluorophenyl) {1‐[2‐(2‐iodophenyl)ethyl]piperidin‐4‐yl}methanone, a potential 5‐HT2A‐antagonist for SPECT brain imaging
Authors: Blanckaert P. , Vandecapelle M. , Staelens L. , Burvenich I. , Dierckx R. A. , Slegers G. 
Published: July 2004

AbstractMany people suffer from psychiatric illnesses like depression and anorexia. Relevant to these diseases is amongst others a malfunctioning of brain 5‐HT2A‐receptors. To allow in vivo quantification of these receptors with Single Photon Emission Computerized Tomography (SPECT), a radiolabelled ligand with high 5‐HT2A affinity is needed.This work reports the radiosynthesis of [123I]‐(4‐fluorophenyl) {1‐[2‐(2‐iodophenyl)ethyl]piperidin‐4‐yl}methanone, the synthesis of its precursor, (4‐fluorophenyl) {1‐[2‐(2‐bromophenyl)ethyl]piperidin‐4‐yl}methanone, and the preliminary in vivo evaluation of the tracer. The precursor was synthesized with a total yield of 40%. Radiolabelling was performed using a halogen exchange reaction and the yield was 70%. Radiochemical purity was >95%, and specific activity was at least 2.4 Ci/µmol. Log P was measured to be 2.52. The tracer showed uptake in mice brain (3.5% I.D./g tissue at 3 min post injection) and therefore will be evaluated further by regional brain biodistribution and displacement studies in rabbits. Copyright © 2004 John Wiley & Sons, Ltd.
Novel benzyl rearrangements in electrospray ionization multistage tandem mass spectra of benzyl 2′,3′‐ didehydro‐2′,3′‐dideoxythymidin‐5′‐yl H‐phosphonate
Authors: Chen Yi , Sun Xiaobin , Fu Hua , Liu Xiaohong , Zhao Yufen 
Published: July 2004

AbstractSeveral alkyl 2′,3′‐didehydro‐2′,3′‐dideoxythymidin‐5′‐yl H‐phosphonates were synthesized and analyzed by electrospray ionization multistage tandem mass spectrometry (ESI − MSn). Two kinds of novel benzyl rearrangement reactions were observed in ESI − MS2 of [M + H]+, [M + Na]+ and [M + K]+ of benzyl 2′,3′‐didehydro‐2′,3′‐dideoxythymidin‐5′‐yl H‐phosphonate. Results from tandem mass spectrometry, high‐resolution mass spectrometry and control experiments showed that the benzyl migration could undergo a four‐membered cyclic rearrangement reaction, and benzyl was essential in the process. Copyright © 2004 John Wiley & Sons, Ltd.
Study of peptide–sugar non‐covalent complexes by infrared atmospheric pressure matrix‐assisted laser desorption/ionization
Authors: Von Seggern Christopher E. , Cotter Robert J. 
Published: July 2004

AbstractInfrared atmospheric pressure matrix‐assisted laser desorption/ionization quadrupole ion trap mass spectrometry was applied to the study of siglec binding to oligosaccharide ligands. Peptides were designed to mimic the binding sites of three members of the siglec family: sialoadhesin, MAG and CD22. These peptides were tested for their ability to complex with their carbohydrate ligands 3′‐sialyllactose (3′SL) and 6′‐sialyllactose (6′SL). All peptides demonstrated the ability to bind to the carbohydrates, with the peptide representing sialoadhesin maintaining its binding specificity for 3′SL in preference to 6′SL. This technique can be used to study other protein–sugar interactions and can be expanded to create high‐throughput screening techniques. Copyright © 2004 John Wiley & Sons, Ltd.