bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical investigations of prostatic acid phosphatase
Authors: Sharma Satyan , Päivi Pirilä  , Kaija Helena , Porvari Katja , Vihko Pirkko , Juffer André H. 
Published: December 2004

AbstractThe phosphotyrosyl protein phosphatase activity of prostatic acid phosphatase (PAP) has been well established. It has also been suggested that PAP partly regulates the activity of growth factor receptors by dephosphorylating the autophosphorylysable tyrosines in them. We studied the binding of the peptides from epidermal growth factor receptor (EGFR) and its homolog (ErbB‐2), corresponding to their autophosphorylation sites, to PAP using theoretical modeling and molecular dynamics (MD) simulation methods. Nine different peptides, each with a phosphotyrosine residue, were docked on human PAP. The binding energies of these peptide–PAP complexes were calculated theoretically and compared to experimentally obtained affinities. The peptide AceDNLpYYWDNH2 from ErbB‐2(1197–1203) showed the most favorable free energy of binding when estimated theoretically. The results demonstrate that the presence of another tyrosine residue proximate to C‐terminal of autophosphorylysable Tyr enhances the binding affinity considerably. The presence of a bulky group instead prevents the binding, as is observed in case of peptide AceNLYpYWDQNH2 which failed to bind, both in theoretical calculations and experiments. Thus we demonstarted that PAP could potentially bind to EGFR and Erbb‐2 and dephosphorylate them. Thus it could be involved in the regulation of the function of such receptors. In addition, complexes of a peptide from AngiotensinII and phosphotyrosine(pY) with human PAP were also modeled. The effects of different protonation states of the titratable active site residues on ligand (pY) binding have also been investigated. For a favorable binding His12 and Asp258 should be neutral, His257 should be positively charged and the phosphate group of the ligand should be in PO state. Furthermore, the analysis of protein motion as observed during simulations suggests the loop–loop contact in the PAP dimer to be of importance in cooperativity. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Correlation between displacive‐type ferroelectricity and electronic density of states near the Fermi level in SrBi2Ta2O9
Authors: Hidaka M. , Soejima M. , Noguchi Y. , Miyayama M. , Choi Sun‐Hee , Sung Nark Eon , Kim Min Gyu , Lee Jay Min 
Published: December 2004

AbstractThe structural deformations around Sr, Bi, and Ta ions, and the electronic density of states near the Fermi level have been studied in paraelectric and ferroelectric phases of the layer pseudo‐perovskite compound, SrBi2Ta2O9 (SBT), by means of X‐ray absorption spectra (XAS) near the absorption edges of Sr, Bi, and Ta ions. The X‐ray absorption near edge structure (XANES) shows that localized largely structural deformations appear around Sr and Ta ions, but not around Bi ion in the vicinity of the ferroelectric to paraelectric structural phase transition. In both phases, there are the charge‐transfer (4dL, 4d2L2, and 4d3L3) bands of Sr, the negative charge‐transfer (5d9L′, 5d8L′2, and 5d7L′3) bands of Bi, and the charge‐transfer 5dnLm bands of Ta. The notations L and L′ represent a hole in the O‐2p valence band, and in the fully occupied 5d band of the Bi ions, respectively. The Sr‐4d, Bi‐5d, and Ta‐5d orbitals are largely hybridized with the 2p orbitals of the nearest‐neighbor oxygen ions occupying the (Bi2O2)2+ sheets or the pseudo‐perovskite blocks (SrTa2O7)2–. This hybridization is induced by an electronic interaction between the cations (Sr, Bi, and Ta ions) and the anions (O ions). The Fermi level is very close to the unoccupied Sr‐5pπ and Ta‐5d(eg) bands, but not the unoccupied Bi‐6dπ band. In the ferroelectric phase, the hybridization between the Bi ion and the oxygen ions (O2) from the (SrTa2O7)2– blocks considerably reduced and almost disappears. This reduction and disappearance of the hybridization increases the effective charges on O2 in the TaO6 octahedra, while the (Bi2O2)2+ layers act only as insulators. Thus, the charge‐up of O2 contributes a large dielectric permittivity of the pseudo‐perovskite (SrTa2O7)2– blocks, in addition to the structural deformation induced near the phase transition at 300 °C. The strong hybridization between the Sr and oxygen ions (O1, O4, and O5) also plays a crucial role to characterize the unusual ferroelectricity in SrBi2Ta2O9 family of compounds substituted Sr ions with other ions or vacancies. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Moving dislocations in general anisotropic piezoelectric solids
Authors: Soh Ai Kah , Liu Jin‐xi , Lee Kwok Lun , Fang Dai‐ning 
Published: December 2004

AbstractThe explicit closed‐form solution is presented for a moving dislocation with the generalized Burgers vector $ {\bf {\tilde b} } $ = [b1, b2, b3, Δφ]T in an anisotropic piezoelectric solid, where Δφ corresponds to an electric dipole layer along the slip plane. The steady‐state version of the Stroh formalism for piezoelectricity is used in this work. Particular attention is paid to the basic characteristics of the electric displacement and electric field due to the moving piezoelectric dislocations. As an important example, a detailed analysis is made for moving dislocations in hexagonal piezoelectric crystals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Relationship between and implications of the isotope and pressure effects on transition temperature, penetration depths and conductivities
Authors: Schneider T. 
Published: December 2004

AbstractIt is shown that the empirical relations between transition temperature, normal state conductivity linearly extrapolated to the value at the transition temperature, zero temperature penetration depths, etc., as observed in a rich variety of cuprate superconductors, are remarkably consistent with the universal critical properties of anisotropic systems which fall into the 3D‐XY universality class and undergo a crossover to a quantum critical point in 2D. The variety includes n‐ and p‐type cuprates, comprises the underdoped and overdoped regimes and the consistency extends up to six decades in the scaling variables. The resulting scaling relations for the oxygen isotope hydrostatic pressure effects agree with the experimental data and reveal that these effects originate from local lattice distortions preserving the volume of the unit cell. These observations single out 3D and anisotropic microscopic models which incorporate local lattice distortions, fall in the experimentally accessible regime into the 3D‐XY universality class, and incorporate the crossover to 2D quantum criticality where superconductivity disappears. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonadiabatic electron–phonon effects in low carrier density superconductors
Authors: Cappelluti E. , Pietronero L. 
Published: December 2004

AbstractDifferent families of unconventional superconductors present a low charge carrier density as a common trait, suggesting that the low charge density can be at the basis of a unifying picture for different superconductors. In the past years we have suggested that the electron–phonon interaction can be responsible for a high‐Tc superconducting pairing in a nonadiabatic regime, where nonadiabatic effects are triggered on by the small electronic Fermi energy associated with the low charge density character. A coherent picture of such a framework requires however reconciling the low charge density and the small Fermi energy with a finite metallic character (sizable density of states and large Fermi surfaces). In this paper we investigate the peculiar conditions which are needed to be encountered in order to fulfill these requirements. We discuss the specific case of fullerenes, cuprates and MgB2 alloys by analyzing their specific structural and electronic properties The comparison between these materials and simple instructive models permits to underline the different routes to reconcile these characteristics in different compounds. In cuprates and fullerenes the interplay between small Fermi energies and large Fermi surface is strictly connected with strong electronic correlation effects. A comprehensive understanding of these issues can be useful to the future search for new nonadiabatic high‐Tc materials. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Residual adenylosuccinase activities in fibroblasts of adenylosuccinase‐deficient children: Parallel deficiency with adenylosuccinate and succinyl‐AICAR in profoundly retarded patients and non‐parallel deficiency in a mildly retarded girl
Authors: Van den Bergh F. , Vincent M. F. , Jaeken J. , Van den Berghe G. 
Published: December 2004

SummaryAdenylosuccinase (ASase) catalyses both the conversion of succinylaminoimidazole carboxamide ribotide (succinyl‐AICAR) into AICAR and that of adenylosuccinate into AMP in the synthesis of purine nucleotides. Its deficiency results in the accumulation in body fluids of the nucleosides corresponding to both substrates, succinyl‐AICAriboside and succinyladenosine. Two main subtypes of the defect are type I with severe mental retardation and succinyladenosine/succinyl‐AICAriboside ratios around 1, and type II with slight mental delay and succinyladenosine/succinyl‐AICAriboside ratios around 4. We report that in fibroblasts of type I patients, the activity of ASase with both adenylosuccinate and succinyl‐AICAR is about 30% of normal. In contrast, in type II fibroblasts, the activity with adenylosuccinate is only 3% of normal, whereas that with succinyl‐AICAR is also 30% of normal. If also present in other tissues, this non‐parallel deficiency provides an explanation for the higher concentration of succinyladenosine in type II. In type I fibroblasts, ASase is further characterized mainly by a 3‐fold to 4‐fold increase inKm for succinyl‐AICAR, and by retarded elution from an anion exchanger. In type II fibroblasts, ASase is characterized by a similar increase inKm for succinyl‐AICAR but by a potent inhibition by KCl and nucleoside triphosphates, and by a normal elution profile. These results suggest a modification of the surface charge of ASase in type I, and the addition of one or more positively charged residues in the active site in type II.
Biochemical diagnosis of mucopolysaccharidoses: Experience of 297 diagnoses in a 15‐year period (1977–1991)
Authors: Di Natale P. , Annella T. , Daniele A. , De Luca T. , Morabito E. , Pallini R. , Rosario P. , Spagnuolo G. 
Published: December 2004

SummaryWe report the results over 15 years (1977–1991) for biochemical diagnoses of patients referred from throughout Italy and suspected of having a mucopolysaccharidosis. Of these, 147 patients were diagnosed as being homozygous or hemizygous for a specific lysosomal enzyme deficiency; 74 pregnancies at risk were monitored in their families; 76 heterozygote diagnoses were performed on their relatives, with a total of 48 positive diagnoses.We also report the analysis of genomic DNA from 11 unrelated Italian Hunter patients, using pc2S15 probe. DNA from two patients, digested with Pst‐I, showed a variant pattern of hybridization caused by deletion or rearrangement of the gene.
Mutation analysis in families with discordant phenotypes of phenylalanine hydroxylase deficiency. Inheritance and expression of the hyperphenylalaninaemias
Authors: Guldberg P. , Levy H. L. , Koch R. , Berlin C. M. , Francois B. , Henriksen K. F. , Güttler F. 
Published: December 2004

SummaryNeonatal hyperphenylalaninaemia caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) represents a wide spectrum of metabolic phenotypes, ranging from classical phenylketonuria (PKU) to mild hyperphenylalaninaemia (MHP). The marked interindividual heterogeneity is due to the expression of multiple PAH mutations in genetic compounds. We have investigated four unusual families in which both PKU and MHP were present. In each family three different mutations in the PAH gene were identified, including two associated with PKU and one associated with MHP. The unexpected outcome of discordant phenotypes within the families described is explained by previously unrecognized parental MHP. By mutation analysis we have also predicted the phenotypical outcome in a hyperphenylalaninaemic infant born to a mother who before pregnancy had been diagnosed as having MHP. Our results demonstrate the utility of nucleic acid analysis in follow‐up in PKU screening programmes.
Mild phenotypic expression of α‐N‐acetylgalactosaminidase deficiency in two adult siblings
Authors: Chabás A. , Coll M. J. , Aparicio M. , Diaz E. Rodriguez 
Published: December 2004

SummaryTwo adult siblings with an α‐N‐acetylgalactosaminidase deficiency are described. The patients' major features are massive lymphoedema and angiokeratoma corporis diffusum. Neurological evaluation performed in one of the patients was considered within normal limits. Blood type is A positive in each case. Ultrastructural examination of skin revealed numerous vacuoles in endothelial cells and pericytes. Fibroblast activity of α‐N‐acetylgalactosaminidase was decreased to 0.6–2% of mean normal value. Chromatography of urinary oligosaccharides showed abnormal bands identical to those excreted by two infantile patients with Schindler disease. The bands were identified as sialyloligosaccharides, and gas chromatography revealed the presence ofN‐acetylgalactosamine‐rich compounds accounting for 30% of the total monosaccharide content of the oligosaccharide fraction.These findings confirm the heterogeneity of α‐N‐acetylgalactosaminidase deficiency and emphasize the need to consider this lysosomal storage disease in the differential diagnosis of patients with angiokeratoma.
Variation in the herd composition counts of sika deer
Authors: Kaji Koichi , Takahashi Hiroshi , Tanaka Junpei , Tanaka Yuka 
Published: December 2004

AbstractHerd composition counts (HCC) are commonly used to assess population status in deer. We evaluated the reliability of HCC of sika deer (Cervus nippon Temminck) using repeated counts and by comparing estimated sex ratios and calf‐to‐female ratios of marked deer on Nakanoshima Island, Hokkaido, Japan between April 1999 and October 2000. Although both total counts and sex and age ratios fluctuated greatly by month, seasonal changes showed a relatively small variance. This suggested that seasonal changes in behavior within sex and age classes contributed to biased ratio estimates obtained from HCC. Route counts should be used as a relative population abundance index with estimates of detection probability, especially for females. Adult sex ratios and age ratios from HCC were unbiased during the rutting season (October–November), and age ratios in spring could be used if yearlings are counted as adults.
Sea Level History in Beringia During the Past 250,000 Years
Authors: Hopkins David M. 
Published: December 2004

AbstractThis paper attempts to relate current knowledge of sea-level history in Beringia to the Broecker-van Donk “Termination” concept of climatic and sea-level history. The Einahnuhtan transgression is thought to represent Termination III, which according to Broecker and van Donk, took place about 225,000 y.a. The Kotzebuan transgression is thought to represent a positive fluctuation that modulated the generally falling sea level during the ensuing 100,000 yr. Sea level probably fell to about −135 m in the Bering Sea area during the maximum phase of the penultimate glaciation. The two Pelukian shorelines probably represent Termination II (about 125,000 yr BP in the Broecker-van Donk chronology) and one of the two positive fluctuations that modulated the generally falling sea level of early Wisconsinan time, about 105,000 and 80,000 y.a. according to Broecker and van Donk. Another positive modulation brought sea level to at least −20 m, about 30,000 y.a. Sea level evidently fell to between −90 and −100 m during the late Wisconsinan regression, but a substantial part of the outer Bering shelf remained submerged. Submerged shoreline features at −38m, −30 m, −24 to −20 m, and −12 to −10 m represent stillstands or slight regressions that modulated Termination I, the late Wisconsinan, and early Holocene recovery of sea level.
Pleistocene Succession of the Central Interior United States
Authors: Frye John C. 
Published: December 2004

AbstractThe Quaternary of the continental interior of the United States is characterized by deposits from glacial ice, with associated outwash and eolian deposits, and by alluvial deposits produced by the same climatic pulses. Erosional incision of valleys occurred early in the glacial pulse, outwash deposition during the waning phase of the pulse, and soil formation during times of relative stability between the glacial pulses. These features of deposition, erosion, and soil formation are presented in a series of curves. One way the marine record could be correlated with that of the continental interior is to compare and match the physical records of both environments.
When did the Last Interglacial end?
Authors: Suggate R.P. 
Published: December 2004

Disagreement on the time of the end of the Last Interglacial stems from lack of an agreed definition of an Interglacial. Although strictly a climatic episode, “Interglacial” as commonly used is essentially a chronologic unit equivalent to an Age, corresponding in time range to the chronostratigraphic unit Stage.The name “Last Interglacial” has gained a global connotation so that its definition must take into account global rather than local effects of temperature fluctuations. An Interglacial begins with a warming to full interglacial warmth (as warm as the present day). It continues until a cooling of full glacial severity occurs, and includes any lesser coolings within a period of fluctuating climate. Such lesser coolings are recorded, particularly in deep-sea cores, following a period of warmth about 125,000 y.a. The cooling that led to the next full glacial cold began about 50,000 yr later. The Last Interglacial lasted from about 128,000 to 73,000 yr BP, equivalent to stage 5 of Shackleton and Opdyke.
Dating Climatic Episodes of the Holocene
Authors: Wendland Wayne M. , Bryson Reid A. 
Published: December 2004

Monitoring evidence indicates that the Holocene embraced a sequence of rather discrete climatic episodes. The transitions between these environmental episodes apparently were abrupt and globally synchronous. This paper reports on statistical analyses of radiocarbon dates associated with environmental change and cultural change.Over 800 14C dates associated with pollen maxima and minima, sea level maxima and minima, and top and bottom surfaces of peat beds were simultaneously analyzed to identify times of globally synchronous environmental discontinuities.Some 3700 14C dates associated with 155 cultural continua of the world were collectively analyzed to identify worldwide synchroneities in appearance and termination of the cultures.Significant globally synchronous discontinuities were identified in each independent analysis. The dates of environmental and cultural discontinuities are rather similar, particularly during the recent half of the Holocene. The fact that the cultural discontinuities mostly follow rather closely those of the paleobotanical record suggests that there has been a distinct climatic impact on the cultural history of man.
Quaternary Deposits in Southwestern Afghanistan
Authors: Smith George I. 
Published: December 2004

Geologic evidence in the closed Seistan Basin of southwestern Afghanistan and adjacent parts of Iran and Pakistan indicates that a lake as much as 65,000 sq km in size occupied this closed depression during Pleistocene time. The deposits consist mostly of lacustrine silt and clay and have a maximum observed thickness of about 250 m. A layer of alluvial gravels overlies the sequence. The deposits are probably early or middle Pleistocene in age; they are old enough to have sustained nearly 300 m of erosion over large areas but are not faulted or detectably folded in the central part of the basin although they are upwarped along the west edge of the basin.Sand dunes cover extensive areas of the basin. Dune orientation shows that the strong surface winds enter the basin blowing toward the south-southeast and then are deflected to the east, apparently as a response to mountains bordering the basin on its south side. The Gawdezereh, a large deflation depression, may be a result of an augmented excavation ability of winds that occurs where turbulence is created along a zone of deflection.
Holocene Insect Fossils from Two Sites at Ennadai Lake, Keewatin, Northwest Territories, Canada
Authors: Elias Scott A. 
Published: December 2004

AbstractEnnadai Lake, in the forest-tundra ecotonal region of Keewatin, Northwest Territories, Canada, has been the subject of several paleoecological investigations (palynology, plant macrofossils, fossil soils). This study concerns Holocene insect fossils at Ennadai, a new approach in a region shown to be sensitive to climatic change. The Ennadai I site yielded 53 taxa, representing 13 families of Coleoptera and 7 families of other insects and arachnids, including abundant ants. These fossils range in age from about 6300 to 630 yr B.P. The Ennadai II site produced fossils of 58 taxa, including 13 beetle families and 15 families of other arthropods, ranging in age from 4700 to 870 yr B.P. The insect evidence suggests the presence of trees in the Ennadai region from 6000 to 2200 yr B.P. A conifer pollen decline from 4800 to 4500 yr B.P. at Ennadai has previously been interpreted as an opening up or retreat of forest in response to climatic cooling, but the insect fossils reveal the continued presence of trees during this interval. Both insect assemblages suggest trends of forest retreat and tundra expansion between about 2200 and 1500 yr B.P., presumably due to climatic cooling, with a return of woodland by about 1000 yr B.P.
Recent Rainfall Trends on the Margins of the Subtropical Deserts: A Comparison of Selected Northern Hemisphere Regions
Authors: Byrne Roger , Granger Orman , Monteverdi John 
Published: December 2004

AbstractAn analysis of recent (1898–1972) seasonal rainfall data from California (winter) and Mexico (summer) provides no evidence of an inverse relationship such as has been reported by Winstanley for climatically analogous areas of Eurasia and Africa. However, California and Old World winter rain trends have been remarkably similar during this time period. Also, summer rain in northwestern Mexico (Mazatlan) correlates highly with winter rainfall in southern California (San Diego) when allowance is made for a 7-year lag. Winstanley suggested that the expansion and contraction of the circumpolar vortex is a primary control of rainfall trends on the margins of the subtropical deserts. The alternative proposed here is that, at least on this time scale, variations in the longitudinal position of troughs and ridges in the upper air westerlies are more important.
Pollen Analysis of Some Mid-Pleistocene Interglacial Lagoonal Sediments from Southern Delaware
Authors: Nickmann Rudy J. , Demarest James M. 
Published: December 2004

AbstractResults of pollen analysis on lagoonal sediments from southern Delaware, dated at 500,000–1,000,000 yr B.P. by amino acid racemization, are presented. Three pollen zones are identified in sediments that were deposited during the final stage of an interglacial cycle. A closed forest of mixed conifer-deciduous trees dominated by Tsuga, Pinus, Fagus, Liquidambar, and Quercus is recorded in the basal zone (Zone I). The inferred climate at this time was temperate and moist. A probable lowering of sea level during the deposition of Zone II exposed large areas in the surrounding estuaries and tidal flats which were colonized by marsh and bog plant taxa. Zone III is characterized by Pinus, Quercus, and Picea pollen. A scrub oak-pine association may have been favored on the coarse sandy soils of the Delmarva Peninsula at this time because of a drop in the local water table. The inferred climate during this interval was colder and probably drier than in Zone I.