bluuebunny/crossref_metadata_2025 huggingface dataset:
Weak Interionic Interactions in 2‐Haloimidazolium Hexahalotellurates(IV) [1]
Authors: Kuhn Norbert , Abu‐Rayyan Ahmed , Eichele Klaus , Piludu Carla , Steimann Manfred
Published: March 2004

The 2‐haloimidazolium salts [C11H20N2X]X [1; X = Cl (a), Br (b)] react with TeX4 to give the salts [C11H20N2X]2[TeX6] [2; X = Cl (a), Br (b)]. The crystal structure analyses of 2a and 2b · CH2Cl2 reveal the presence of ionic pairs linked by weak halogen to halogen interactions.
Polyol‐Metall‐Komplexe.47 Kristalline D‐Mannose‐Kupfer(II)‐Komplexe aus Fehlingscher Lösung
Authors: Klüfers Peter , Kunte Thomas
Published: March 2004

Blaue, zersetzliche Kristalle von K3[Cu5(β‐D‐Manp)4H—13] · α‐D‐Manp · 16.5 H2O (1), die einen pentanuclearen Kupfer(II)‐Komplex des reduzierenden Zuckers D‐Mannose in der β‐Pyranoseform (β‐D‐Manp) enthalten, werden aus eiskalten wässrig‐alkalischen Lösungen erhalten. Das homoleptische Pentacuprat enthält verbrückende Mannopyranose‐Liganden, welche die Ladung 4— und 2.5— tragen. Zusatz von Ethylendiamin (en) zu den Fehling‐Lösungen führt zur Kondensation des Diamins mit Mannose zu N, N′‐Bis(β‐D‐mannopyranosyl)‐ethylendiamin (L). Es können Kristalle von [(en)2Cu7(β‐D‐Manp1, 2, 3, 4H—4)2(L2, 3, 4H—3)2] · 26.6 H2O (2) isoliert werden, deren heptanuclearer CuII‐Komplex sich vom homoleptischen Mannosekomplex strukturell ableitet.
Synthesis and Characterization of some Unsymmetrical Schiff Base Ligands and their Nickel(II) Complexes Incorporating o‐Phenylenediimine Units
Authors: Opozda Ewa M. , Łasocha Wiesław , Włodarczyk‐Gajdab Barbara
Published: March 2004

Six new nickel(II) complexes of the unsymmetrical Schiff base ligands derived from o‐phenylenediamine were synthesized. These complexes were prepared by template and non‐template reactions of the precursor 3‐acetyl‐4‐[N‐(2'‐aminophenyl)‐amino]‐3‐buten‐2‐one (HL°) with appropriate o‐hydroxycarbonyl aromatic compounds, aromatic 1, 3‐oxo aldehydes and 1, 3‐diketones.

The nickel(II) compounds were characterized by analytical and spectroscopic methods. Crystal structure of complex [3‐acetyl‐(6, 7)‐benzo‐8‐salicylidene‐5, 8‐diazahepta‐3‐ene‐2‐onato(2‐)]nickel(II) (NiL1) has been determined by X‐ray powder diffraction method, revealed that the molecules are almost flat, and there are no forces other than van der Waals interactions between molecules. The structure was solved by global optimisation technique and refined by the Rietveld method, obtained RF and Rwp are 11.6 and 17.4%, respectively. The synthesis of a new unsymmetrical nickel(II) tetraazamacrocyclic complex is also described.
Sandwichartige Polyoxowolframate mit Indium(III) als Heteroatom — Synthese und Charakterisierung der ersten Vertreter einer neuen Familie von Anionen
Authors: Limanski E. M. , Drewes D. , Krebs B.
Published: March 2004

Die Synthesen von drei neuen Polyoxowolframaten mit Indium als Heteroatom werden vorgestellt. Die Verbindungen wurden vollständig durch Röntgenstrukturanalysen sowie IR‐ Spektroskopie und Elementaranalyse charakterisiert. Die neuartigen Verbindungen stellen die ersten Beispiele für sandwichartige Heteropolyanionen dar, die mit Indium(III) ein Element der dritten Hauptgruppe enthalten. Die Heteropolyanionen in Na5nH2n[{In(H2O)2}1, 5{Na(H2O)2}0, 5{In(H2O)2}2(SbW9O33)2]n · 28n H2O (1) und Na2K2H2[{In(H2O)3}2{In(H2O)2}2(AsW9O33)2] · 37 H2O (2) sind dem sogenannten M2X2M20‐Typs zuzuordnen. Sie sind aus zwei β‐B‐[XW9O33]‐Fragmenten aufgebaut, die sich von Defektstrukturen des Keggin‐Anions ableiten lassen. Diese Untereinheiten sind über vier MO6‐Oktaeder (M = InIII bzw. Na in 1 und InIII in 2) verknüpft und bilden so den M2X2M20‐Typ aus. Das Anion in Na10H2[In4(H2O)2(CoW9O34)2] · 43 H2O (3) ist ein neuer Vertreter des M4X2W18‐Typs, in dem zwei α‐B‐[XW9O34]‐Einheiten über einen Ring aus vier InO6‐Oktaedern verknüpft sind.

1 kristallisiert im monoklinen Kristallsystem (C2/c) mit a = 19, 370(4), b = 17, 852(4), c = 30, 015(6) Å und β = 97, 38(3)°. 2 kristallisiert im monoklinen Kristallsystem (C2/m) mit a = 20, 323(4), b = 15, 269(3), c = 16, 014(3) Å und β = 94, 06(3)°. 3 zeigt Gitterkonstanten von a = 13, 047(3), b = 17, 735(4), c = 21, 054(4) Å und einen Winkel β = 93, 38(3)° bei monoklinem Gitter (Raumgruppe P21/n).
Ti5Se4: The First Step of Cluster Condensation with Titanium Selenides
Authors: He Meng , Simon Arndt , Duppel Viola
Published: March 2004

A new Ti5Te4‐type compound, Ti5Se4, has been identified and its structure is refined against x‐ray powder diffraction data with the Rietveld method. It has a body‐centered tetragonal unit cell with lattice parameters a = 9.6728(1) Å, c = 3.5083(1) Å, space group I4/m. This compound is the first titanium selenide which consists of separated M5X4 (M = metal, X = metalloid) chains. The effect of atomic radii on the formation of the Ti5Te4‐type structure is discussed.
Synthese, Kristallstruktur und thermischer Abbau von Mg(H2O)6[B12H12] · 6 H2O
Authors: Tiritiris Ioannis , Schleid Thomas
Published: March 2004

Bei der Umsetzung einer wäßrigen Lösung der Säure (H3O)2[B12H12] mit MgCO3 und anschließendem isothermen Eindampfen der erhaltenen Lösung entstehen farblose, polyederförmige Einkristalle von Magnesium‐Dodekahydro‐closo‐Dodekaborat‐Dodekahydrat Mg(H2O)6[B12H12] · 6 H2O (kubisch, F4132; a = 1643, 21(9) pm, Z = 8). Die Kristallstruktur läßt sich auf den NaTl‐Strukturtyp zurückführen, wobei die Schwerpunkte der quasi‐ikosaedrischen [B12H12]2—‐Anionen (d(B—B) = 178—180 pm, d(B—H) = 109 pm) die Tl—‐ und die Mg2+‐Kationen die Na+‐Positionen besetzen. Ein direkter koordinativer Einfluß der [B12H12]2—‐Einheiten auf die Mg2+‐Kationen ist nicht festzustellen. Letztere werden lediglich von sechs Sauerstoffatomen der umgebenden Wassermoleküle oktaedrisch koordiniert und bilden isolierte Hexaaqua‐Komplexkationen [Mg(H2O)6]2+ (d(Mg—O) = 206 pm, 6×). Zusätzlich dazu sind in der Kristallstruktur sechs „zeolithische”︁ Wassermoleküle lokalisiert, die für die Bildung eines starken O—Hδ+···δ—O‐Wasserstoffbrückenbindungssystems sorgen. Die Ausbildung schwacher B—Hδ—···δ+H—O‐Wasserstoffbrücken wird ebenfalls diskutiert. Differenzthermoanalytische und thermogravimetrische Studien zum thermischen Verhalten des Dodekahydrats Mg[B12H12] · 12 H2O (≡ Mg(H2O)6[B12H12] · 6 H2O) belegen erwartungsgemäß einen zweistufigen Abbau im Temperaturbereich zwischen 71 und 76 °C sowie bei 202 °C, der schließlich zum wasserfreien Magnesium‐Dodekahydro‐closo‐Dodekaborat Mg[B12H12] führt.
A Novel 3‐D Heterobimetallic Cyano‐bridged Coordination Polymer Incorporating Ag···Ag Interaction: [Cu(dien)Ag(CN)2]2[Ag2(CN)3][Ag(CN)2]
Authors: Zhou Hui‐Bo , Dong Wen , Liang Mao , Liao Dai‐Zheng , Jiang Zong‐Hui , Yan Shi‐Ping , Cheng Peng
Published: March 2004

A three‐dimensional cyano‐bridged copper(II) complex, [Cu(dien)Ag(CN)2]2[Ag2(CN)3][Ag(CN)2] (1) (dien = diethylenetriamine), has been prepared and characterized by X‐ray crystallography. Complex 1 crystallized in the monoclinic space group P21/n with a = 6.988(2), b = 17.615(6), c = 12.564(4) Å, β = 90.790(5)°. The crystal consists of cis‐[Cu(dien)]2+ units bridged by [Ag(CN)2]— to form a zig‐zag chain. The Ag atoms of the free and bridging [Ag(CN)2]— link together to form additional infinite zig‐zag chains with short Ag···Ag distances. The presence of Ag···Ag interactions effectively increases the dimensionality from a 1‐D chain to a 3‐D coordination polymer.
Syntheses and Crystal Structures of Two Sodium Ruthenates: Na2RuO4 and Na2RuO3
Authors: Mogare Kailash M. , Friese Karen , Klein Wilhelm , Jansen Martin
Published: March 2004

Na2RuO4, prepared from Na2O2 and RuO2 via high oxygen pressure synthesis, crystallises monoclinic in space group P21/c (a = 10.721(6), b = 7.033(4), c = 10.871(6) Å, β = 119.10(4)°, Z = 8, 2503 unique reflections, R1 = 0.049). Structure determination from single crystal data shows that the compound consists of infinite chains of RuO5 trigonal bipyramids connected through their axial vertices. The Na cations connect the pseudohexagonally packed [RuO3O2/2] chains and are coordinated by six or seven oxygen atoms, respectively. The compound exhibits an one‐dimensional spin system with μ = 2.80 μB and Θ = —222 K and a three‐dimensional antiferromagnetic ordering below 50 K. Na2RuO3 was obtained from Na2RuO4 at 850 °C under a flow of argon. The structure was determined from X‐ray powder diffraction. It is closely related to the α‐NaFeO2 and the Li2SnO3 structure types, layered variants of the NaCl type. In Na2RuO3 the Na and Ru atoms are partially disordered. This partially disordered state was approximated by a Rietveld refinement of two superimposed structural models (model I: R 3¯ m, a = 3.12360(5), c = 16.0370(4) Å, Z = 2; model II: C2/c, a = 5.4141(4), b = 9.3663(6), c = 10.8481(4) Å, β = 99.636(9)°, Z = 8).
Enhanced activation of and increased production of matrix metalloproteinase‐9 by human blood monocytes upon adhering to carbamylated collagen
Authors: Garnotel Roselyne , Sabbah Nadia , Jaisson Stéphane , Gillery Philippe
Published: March 2004

Carbamylation refers to chemical modification of protein side chains by cyanate derived e.g. from urea. It alters their structural and functional properties. We have studied the influence of the carbamylation of type I collagen in vitro on its interactions with elutriated human monocytes, and its potential role in atherosclerosis. Adhesion of monocytes onto carbamylated collagen was significantly enhanced compared to native collagen. There was no change in superoxide anion production. On the other hand, there was an increase in the production and the activation of matrix metalloproteinase‐9. No effect was found on tissue inhibitor of metalloproteinase‐1 production. Thus, the presence of carbamylated collagen may stimulate the remodelling of extracellular matrix mediated by activated monocytes. Such alterations may contribute to enhanced atherosclerosis in renal insufficiency, a pathological condition associated with elevated levels of carbamylation.
Identification of a fatty acid Δ11‐desaturase from the microalga Thalassiosira pseudonana1
Authors: Tonon Thierry , Harvey David , Qing Renwei , Li Yi , Larson Tony R , Graham Ian A
Published: March 2004

A set of genomic DNA sequences putatively encoding front‐end desaturases were identified by in silico analysis of the draft genome of the marine microalga Thalassiosira pseudonana. Among these candidate genes, an open reading frame named TpdesN was found to be full‐length, intronless, and constitutively expressed during cell cultivation. The predicted amino acid sequence of the corresponding protein, TpDESN, exhibited typical features of desaturases involved in the production of polyunsaturated fatty acids (PUFAs) in algae, i.e. a cytochrome b5‐like domain at the N‐terminus and three conserved histidine‐rich motifs in the desaturase domain. Expression of TpDESN in Saccharomyces cerevisiae revealed that this enzyme was not involved in PUFA synthesis, but specifically desaturated palmitic acid 16:0 to 16:1Δ11. To our knowledge, until this report, Δ11‐desaturase activity had only been detected in insect cells.
The role and structure of mitochondrial carriers
Authors: Kunji Edmund R.S
Published: March 2004

Members of the mitochondrial carrier family transport compounds over the inner mitochondrial membrane to link the biochemical pathways in the cytosol with those in the mitochondrial matrix. X‐ray crystallography has recently provided us with the first atomic model of the bovine ADP/ATP carrier, which is a member of this family. The structure explains the typical three‐fold sequence repeats and signature motif of mitochondrial carriers. However, the carrier was crystallised as a monomer in detergent, which is inconsistent with the consensus that mitochondrial carriers exist as homo‐dimers. The projection structure of the yeast ADP/ATP carrier by electron crystallography shows that carriers could form homo‐dimers in the membrane.
Identification of proteins differentially expressed during chondrogenesis of mesenchymal cells
Authors: Lee Sun Joo , Jeon Hong Bae , Lee Jeung Hwa , Yoo Jong Shin , Chun Jang-Soo , Yoo Yung Joon
Published: March 2004

We performed comparative proteome analysis of mesenchymal cells and chondrocytes to identify proteins differentially expressed during chondrogenesis. Nine such proteins were identified. Type II collagen, matrilin‐1, carbonic anhydrase‐II (CA‐II), 3′‐phosphoadenosine 5′‐phosphosulfate (PAPS) synthetase‐2, and aldo‐keto reductase were increased during chondrogenesis, whereas cellular retinoic acid binding protein‐I (CRABP‐I), CRABP‐II, cytoplasmic type 5 actin, and fatty acid binding protein were decreased or almost disappeared. Expression of type II collagen, matrilin‐1, PAPS synthetase‐2, and CA‐II was regulated by extracellular signal‐regulated protein kinase, protein kinase C, and p38 kinase, signaling molecules known to regulate chondrogenesis.
A comparison between methods for linkage disequilibrium fine mapping of quantitative trait loci
Authors: ABDALLAH JIHAD M. , MANGIN BRIGITTE , GOFFINET BRUNO , CIERCO-AYROLLES CHRISTINE , PÉREZ-ENCISO MIGUEL
Published: March 2004

We present a maximum likelihood method for mapping quantitative trait loci that uses linkage disequilibrium information from single and multiple markers. We made paired comparisons between analyses using a single marker, two markers and six markers. We also compared the method to single marker regression analysis under several scenarios using simulated data. In general, our method outperformed regression (smaller mean square error and confidence intervals of location estimate) for quantitative trait loci with dominance effects. In addition, the method provides estimates of the frequency and additive and dominance effects of the quantitative trait locus.
Mendelian sampling terms as a selective advantage in optimum breeding schemes with restrictions on the rate of inbreeding
Authors: AVENDAÑO S. , WOOLLIAMS J. A. , VILLANUEVA B.
Published: March 2004

Quadratic indices are a general approach for the joint management of genetic gain and inbreeding in artificial selection programmes. They provide the optimal contributions that selection candidates should have to obtain the maximum gain when the rate of inbreeding is constrained to a predefined value. This study shows that, when using quadratic indices, the selective advantage is a function of the Mendelian sampling terms. That is, at all times, contributions of selected candidates are allocated according to the best available information about their Mendelian sampling terms (i.e. about their superiority over their parental average) and not on their breeding values. By contrast, under standard truncation selection, both estimated breeding values and Mendelian sampling terms play a major role in determining contributions. A measure of the effectiveness of using genetic variation to achieve genetic gain is presented and benchmark values of 0·92 for quadratic optimisation and 0·5 for truncation selection are found for a rate of inbreeding of 0·01 and a heritability of 0·25.
Porcine genomics delivers new tools and results: This little piggy did more than just go to market
Authors: ROTHSCHILD MAX F.
Published: March 2004

The past decade has yielded new tools for pig geneticists and breeders thanks to the considerable developments resulting from efforts to map the pig genome. The pig genetic linkage map now has nearly 5000 loci including several hundred genes, microsatellites and amplified fragment length polymorphisms (AFLP) markers. Using tools that include somatic cell hybrid panels and radiation hybrid panels, the physical genetic map is also growing rapidly and has over 4000 genes and markers. Scientists using both exotic and commercial breeds for quantitative trait loci (QTL) scans and candidate gene analyses have identified a number of important chromosomal regions and individual genes associated with growth rate, leanness, feed intake, meat quality, litter size and disease resistance. Using marker-assisted selection (MAS) the commercial pig industry is actively incorporating these gene markers and traditional performance information to improve traits of economic importance in pig production. Researchers now have novel tools including pig gene arrays and advanced bioinformatics that are being exploited to find new candidate genes and to advance the understanding of gene function in the pig. Sequencing of the pig genome has been initiated and further sequencing is now being considered. Advances in pig genomics and directions for future research and the implications to both the pig industry and human health are reviewed.
Black economic power and nation-building in post-apartheid South Africa
Authors: Iheduru Okechukwu C.
Published: March 2004

This paper evaluates the evolution and the implementation of the ANC government's commitment to fostering a black capitalist class or black economic empowerment (BEE) as a non-racial nation-building strategy. A substantial black bourgeois i.e. and other middle classes begun to emerge over the last decade, contrary to popular perceptions. The legitimating role assigned to the emergent black bourgeoisie by the ANC and the government is, however, threatens to turn the strategy into a nepotistic accumulation. This development is paradoxically threatening to re-racialise the country, widening black inequality gaps, and precluding the rise of a black bourgeoisie with a nurture capitalist agenda. Other equally powerful social groups have begun to challenge the prevailing strategy, compelling the government to explore a more accommodating strategy exemplified by the recent introduction by the government of ‘broad-based economic empowerment’. Should a less patrimonial, less racially and ethnically divisive BEE strategy emerge from this quasi-pluralist power play, such a change holds prospects for the creation of a ‘growth coalition’ capable of sustainable capitalist development and true empowerment of the black majority. That would be a positive development in terms of establishing and consolidating democracy in South Africa.
Challenge without transformation: refugees, aid and trade in western Tanzania
Authors: Landau Loren B.
Published: March 2004

Through a comparison of two rural Tanzanian districts, this paper traces the effects of a humanitarian influx – the arrival of refugees and international relief – on the economic practices of the host population in one western Tanzanian district (Kasulu). It argues that, despite popular and Government claims to the contrary, there is little evidence that the influx has effected a transformation of citizens' economic lives. While changes in exchange and resource use patterns have occurred in the five years since the influx began, they are not fundamental and many are better attributed to shifts in macro-economic policy than to the refugees, the presence of the relief agencies or the distribution of humanitarian aid. The fact that the influx has not induced a shift towards increased market activity and capitalist modes of production not only challenges government and popular pronouncements, but also reaffirms the resilience of localised modes of production against external market pressures.
Phylogeny of the Micareaceae inferred from nrSSU DNA sequences
Authors: ANDERSEN Heidi L. , EKMAN Stefan
Published: March 2004

The phylogeny of the Micareaceae and the genus Micarea Fr. was studied using 39 nuclear small subunit ribosomal DNA sequences. Phylogenetic analyses were carried out using maximum parsimony, maximum likelihood, and Bayesian inference. A confidence set of trees was estimated using expected likelihood weights to investigate a series of hypotheses of monophyly. Tree topologies were very similar between methods and differed only in the placement of a few poorly supported branches. The results indicate that the Micareaceae in its current circumscription belongs in the Lecanorales, but that it is not monophyletic. Psilolechia, Micarea with a ‘non-micareoid’ photobiont, Micarea sensu stricto and Byssoloma form a paraphyletic grade in this study. Micarea sensu stricto and Byssoloma (Pilocarpaceae) form a strongly supported monophyletic group, which constitutes the sister group to the Bacidiaceae. Scoliciosporum A. Massal has sometimes been considered close to Micarea, but no support was found for that hypothesis.
Anatomy of the endolithic Sonoran Desert lichen Verrucaria rubrocincta Breuss: implications for biodeterioration and biomineralization
Authors: BUNGARTZ Frank , GARVIE Laurence A. J. , NASH Thomas H.
Published: March 2004

The anatomy of the endolithic, calcicolous lichen Verrucaria rubrocincta Breuss is described using optical and scanning electron microscopy. This lichen is locally abundant in caliche plates of open desert pavements in the Sonoran Desert of south-western Arizona. The endolithic growth of V. rubrocincta is distinctly layered. The upper layer is a fine-grained calcite (micrite). This layer is sparsely penetrated by hyphae and therefore cannot be interpreted as a lithocortex sensu stricto. Beneath the micrite is the photobiont layer. Below this photobiont layer hyphae form a pseudomedulla penetrating up to 1 cm into the caliche. Calcium oxalates occur in the pseudomedulla but are absent from uninhabited caliche. The analogy of a greenhouse describes the ecophysiological adaptations of this endolithic growth to the environmental extremes of the Sonoran Desert. The micrite acts as a roof and the photobiont layer and pseudomedulla represent the greenhouse interior. Verrucaria rubrocincta has thus evolved a strategy to successfully establish and survive within an extreme environment. Our study illustrates biodeterioration and biomineralization processes acting simultaneously within a single lichen species. Mineralogical evidence suggests that the micrite on the thallus surface is biologically induced. The hyphae of the lichen biodeteriorate the caliche thus forming the pseudomedulla. Simultaneously with this process micrite forms at the surface protecting the thallus from exposure and counter-balancing rock degradation. These combined effects of biodeterioration and biomineralization do not markedly accelerate erosion because inhabited and uninhabited areas of the same plate show similar surface heights.
Lichenoconium christiansenii sp.nov. from Nodobryoria abbreviata (Parmeliaceae) in the Pacific Northwest, with a key to the known lichenicolous species
Authors: COLE Mariette S. , HAWKSWORTH David L.
Published: March 2004

Lichenoconium christiansenii sp. nov. is described and illustrated from the apothecia of Nodobryoria abbreviata (syn. Bryoria abbreviata) in Washington State, USA. The species recalls L. lichenicola, but differs in the more subglobose conidia and the shorter conidiogenous cells as well as in occurring on a different host. A key to the 14 species now known in the genus is provided. Lichenoconium cargillianum is also reported from Letharia vulpina for the first time.
Ammonium uptake in the nitrophytic lichen Xanthoria parietina and its effects on vitality and balance between symbionts
Authors: GAIO-OLIVEIRA Gisela , DAHLMAN Lena , PALMQVIST Kristin , MÁGUAS Cristina
Published: March 2004

The aim of this investigation was to determine the NH4Cl concentration threshold, above which negative physiological effects would occur in the nitrophytic lichen Xanthoria parietina. Over a 10 month period, X. parietina thalli growing on roof tiles were exposed weekly to NH4Cl concentrations of 0·04, 0·17, 0·34 or 0·69 M. Nitrogen (N) uptake from ammonium and the concentrations of total thallus N and biont markers (chlorophyll a, ergosterol and chitin) were measured on four occasions, over the experimental period. Xanthoria parietina was able to assimilate a significant quantity of the applied ammonium. However, lichens exposed to the two higher concentrations suffered damage to both the photobiont and the mycobiont, as evidenced by reduced chlorophyll a and ergosterol concentrations, while lichens exposed to the two lower concentrations showed no significant changes in either chlorophyll a or ergosterol that could be related to the ammonium inputs. Xanthoria parietina tolerated a weekly irrigation of at least 0·17 M NH4Cl, corresponding to an N deposition of c. 1000 kg ha−1 yr−1, suggesting that this species has a very high tolerance to N pollution.
Normal Reference Value of Hemoglobin of Older Boys and Geographical Factors
Authors: Miao Ge
Published: March 2004

In order to supply a scientific basis for uniting the normal reference value standard of hemoglobin of Chinese older boys. Methods: A research is made about the relationship between the normal reference value of 14751 examples of hemoglobin of older boys and five geographical factors in 92 areas in China, which are determined by the hemoglobincyanide method. Results: It is found that the correlation of geographical factors and the normal reference value of hemoglobin of older boys are quite significant (F = 9.68). By using the method of multiple linear regression analysis, one regression equation is inferred:

Ŷ = 108.0 + 0.003633X1 + 0.003945X2 + 0.1680X3 − 0.6310X4 + 0.005518X5 ± 8.3

Conclusion: If geographical values are obtained in some areas, the normal reference value of hemoglobin of older boys of this area can be reckoned by using the regression equation. Furthermore, the depending on the geographical factors, China can be divided into six districts: Qingzang, Southwest, Northwest, Southeast, North and Northeast district.
Characterization of a High Affinity Folate Binding Protein in Porcine Serum: Ionic Charge, Concentration—Dependent Polymerization and Ligand Binding Mechanism
Authors: Holm Jan , Ingemann Hansen Steen
Published: March 2004

The folate binding protein in porcine serum, present at concentrations of 50-100 nM, is cationic at near neutral pH as evidenced by ion exchange chromatography. The gel filtration profile of the protein isolated from porcine serum by methotrexate affinity chromatography exhibited one peak at 48 kDa and an additional peak of 91 kDa at higher protein concentrations. This could suggest the involvement of concentration-dependent polymerization phenomena. Binding of [3H] folate was of a high-af.nity type with upward convex Scatchard plots and Hill coefficients >1.0 indicative of apparent positive cooperativity. However, binding to protein isolated from porcine serum after affinity chromatography was biphasic (high/low-affinity) in the absence of Triton X-100, 1 g/1. These findings which are similar to those reported for purified milk folate binding proteins are consistent with a model predicting association between unliganded and liganded monomers to weak-ligand affinity heterodimers. Amphiphatic substances, e.g. Triton X-100, form micelles which could separate hydrophobic unliganded monomers from hydrophilic liganded monomers (monomers are hydrophilic in the liganded state) thereby preventing heterodimerization. The folate analogue N10 methyl folate was a potent and competitive inhibitor of [3H] folate binding to the folate binding protein, and moreover changed the binding type to apparent negative cooperativity.
Coherent structures beneath wind waves and their influence on air‐water gas transfer
Authors: Siddiqui M. H. Kamran , Loewen Mark R. , Asher William E. , Jessup Andrew T.
Published: March 2004

Coherent structures generated beneath laboratory wind waves were investigated using particle image velocimetry. An algorithm was developed to detect these structures and to determine their size, vorticity, and kinetic energy. As the wind speed increased from 4.5 to 11.0 m s−1, the maximum vorticity of the coherent structures increased by 40%, their average size increased by 20%, their frequency of occurrence increased 400%, and the fraction of the water surface renewed by coherent structures increased from 0.12 to 0.33. Distributions of the total kinetic energy of the coherent structures as a function of size showed that the most energetic eddies occurred in the size range 0.8–1.6 cm in diameter. The near‐surface flow could be divided into areas with one of two distinct characteristics: energetic regions occupied by coherent structures and quiescent regions largely devoid of coherent structures. A surface renewal model for air‐water exchange was used to calculate the local transfer velocity in both types of regions. The model predicted that the gas transfer velocities in the energetic regions were 2.8 times larger than in the quiescent regions and that 60% of the total air‐water gas flux occurred across the energetic regions at all wind speeds. In addition, the rate of turbulent kinetic energy dissipation was ∼2.5 times higher in the energetic regions compared to the quiescent regions at all wind speeds.
Late Neogene benthic stable isotope record of Ocean Drilling Program Site 999: Implications for Caribbean paleoceanography, organic carbon burial, and the Messinian Salinity Crisis
Authors: Bickert Torsten , Haug Gerald H. , Tiedemann Ralf
Published: March 2004

We report on epibenthic foraminiferal δ18O and δ13C and percentage coarse fraction records from Caribbean Ocean Drilling Program (ODP) Site 999 (12°44′N, 78°44′W, water depth 2828 m) spanning the interval from 8.5 to 5.3 Ma. Low epibenthic δ13C values and low amounts of sand‐sized particles (mostly foraminifer shells) indicate a poorly ventilated deep Caribbean throughout the late Miocene. At this time the deep Caribbean was dominated by a nutrient‐rich and corrosive water mass. A generally constant δ13C gradient between the Caribbean and deep Atlantic records during the late Miocene suggests that the fluctuations in δ13C reflect global changes in δ13C of the dissolved inorganic carbon due to varying erosion of organic carbon from terrigenous soils and shelf sediments. The observed 100‐kyr cyclicity of epibenthic δ13C is in good accordance with the variability of terrigenous input to the equatorial Atlantic as recorded by magnetic susceptibility records of the Ceara Rise. However, some short‐term gradient changes between 7.0 and 4.5 Ma indicate a poorer ventilation of the deep Atlantic related to a reduced production of deep water in the Atlantic. The Messinian Salinity Crisis between 6.0 and 5.3 Ma did not affect the intermediate to deep water gradient between the Caribbean and the Atlantic. Comparison to the Bahama platform record of ODP Site 1006, however, indicates a poorer ventilation of the shallower northern Caribbean basins coincident with the isolation of the Mediterranean Sea.
Detection of the southern counterpart of the Jovian northern polar cusp: Shared properties
Authors: Pallier Laurent , Prangé Renée
Published: March 2004

A transient auroral feature in the northern (N) polar region of Jupiter, referred to as an ‘auroral flare’ [Waite et al., 2001], or as the N polar cusp [Pallier and Prangé, 2001], strangely seemed to lack any southern (S) counterpart. Here, using a new HST/STIS dataset, we find a similar bright spot in the south. We suggest that both features are located near the open/closed field line boundary. They remain close to a fixed‐magnetic‐time profile, near noon, as Jupiter rotates. Their brightness varies concurrently in both hemispheres. We thus propose that the conjugate spots are really the Jovian polar cusps, and that their brightening results from transient reconnection processes with the interplanetary magnetic field. A STIS spectrum reveals primary particles penetrating deeply into the atmosphere. It implies that either the particles are very energetic (∼200 keV ‘equivalent‐electron’ energy), or the hydrocarbon layers are significantly uplifted by the power input.
Aerosol black carbon over Arabian Sea during intermonsoon and summer monsoon seasons
Authors: Babu S. Suresh , Moorthy K. Krishna , Satheesh S. K.
Published: March 2004

Extensive, collocated measurements of the mass concentrations of composite and black carbon (BC) aerosols were made over coastal Arabian Sea, adjoining Indian Peninsula, for the first time during the inter‐monsoon and summer monsoon periods, of 2003, as part of Arabian Sea Monsoon Experiment (ARMEX). Results showed that the diurnal variations are weak in March, and vanish completely by May/June, associated with the change in the synoptic circulations. The concentration of BC (and its share to total aerosol mass) decreases continuously, from ∼700 ng m−3 (2.5%) in March to ∼104 ng m−3 (0.5%) by June. Consequently, the net atmospheric forcing (heating) efficiency decreases from ∼70 W m−2 (for reported winter conditions) to ∼30 W m−2 for inter‐monsoon and to ∼15 W m−2 for summer monsoon seasons. These will have implications on regional climate forcing.
Allometric power‐law relationships in a Hortonian fractal digital elevation model
Authors: Sagar B. S. Daya , Tien Tay Lea
Published: March 2004

We provide a topologically viable model that is geomorphologically realistic from the point of its Hortonity and general allometric scaling laws. To illustrate this, we consider a fractal binary basin, generated in such a way that it follows certain postulates, and decompose it into various coded topologically prominent regions the union of which is defined as geomorphologically realistic Fractal‐DEM. We derive two unique topological networks from this Hortonian fractal DEM based on which we derive allometric power‐law relationships among the basic measures of decomposed sub‐basins of all orders ranging from ω = 1 to ω = Ω. Our results are in good accord with optimal channel networks and natural river basins.
Dense and stagnant ions in the low‐latitude boundary region under northward interplanetary magnetic field
Authors: Hasegawa H. , Fujimoto M. , Saito Y. , Mukai T.
Published: March 2004

The ion behavior in the low‐latitude boundary region is studied based on Geotail data accumulated over several years, toward understanding the formation mechanism of the cold‐dense plasma sheet under prolonged northward interplanetary magnetic field (IMF). A statistical survey shows that, during extended northward IMF, (1) dense magnetosheath‐like ions appear far more often, especially on the flanks, (2) the dense ions are mostly stagnant, in contrast to those in the classical low‐latitude boundary layer (LLBL), (3) a substantial fraction of the dense and stagnant ions is spatially mixed with hot magnetospheric ions, and (4) the mixed ion population has magnetic local time dependence in ion mixing state in energy space. Based on these findings, we argue that, under extended northward IMF, a significant transfer of the solar wind/LLBL ions onto the magnetospheric field lines occurs on the flanks, and the transport/heating process of the entrant ions is different for different local times.
A late medieval warm period in the Southern Ocean as a delayed response to external forcing?
Authors: Goosse H. , Masson‐Delmotte V. , Renssen H. , Delmotte M. , Fichefet T. , Morgan V. , van Ommen T. , Khim B. K. , Stenni B.
Published: March 2004

On the basis of long simulations performed with a three‐dimensional climate model, we propose an interhemispheric climate lag mechanism, involving the long‐term memory of deepwater masses. Warm anomalies, formed in the North Atlantic when warm conditions prevail at surface, are transported by the deep ocean circulation towards the Southern Ocean. There, the heat is released because of large scale upwelling, maintaining warm conditions and inducing a lagged response of about 150 years compared to the Northern Hemisphere. Model results and observations covering the first half of the second millenium suggest a delay between the temperature evolution in the Northern Hemisphere and in the Southern Ocean. The mechanism described here provides a reasonable hypothesis to explain such an interhemipsheric lag.
Permeability structure around an ancient exhumed subduction‐zone fault
Authors: Kato Aitaro , Sakaguchi Arito , Yoshida Shingo , Yamaguchi Haruka , Kaneda Yoshiyuki
Published: March 2004

We conducted permeability measurements on rocks sampled from an exhumed ancient subduction zone fault in the Cretaceous Shimanto accretionary complex of Japan. The permeability under seismogenic environment conditions shows a heterogeneous structure across the fault zone. Permeability of the sandstone in turbidite sequence is the lowest, whereas the highly sheared zone has the largest permeability. A combination of permeability contrast between these two zones and fluid pressure source, including tectonically driven burial and dehydration, could result in a concentration of pore fluids along the fault, which causes Deep Seismic Reflections during underplating stage as delineated in seismic reflection studies. Following a rise of temperature up to 250°C, the permeability of all the sampled rock types became smaller than at room temperature, and also gradually decreased with increasing hold time.
Impact of Amazonian deforestation on atmospheric chemistry
Authors: Ganzeveld Laurens , Lelieveld Jos
Published: March 2004

A single‐column chemistry and climate model has been used to study the impact of deforestation in the Amazon Basin on atmospheric chemistry. Over deforested areas, daytime ozone deposition generally decreases strongly except when surface wetness decreases through reduced precipitation, whereas nocturnal soil deposition increases. The isoprene and soil nitric oxide emissions decrease although nitrogen oxide release to the atmosphere increases due to reduced canopy deposition. Deforestation also affects vertical transport causing substantial ozone and hydroxyl changes, also depending on soil moisture. The analysis shows that assessment of the impact of land cover and land use changes on atmospheric chemistry requires the development of explicitly coupled chemistry and meteorological models including surface trace gas exchanges, micro‐meteorology and the hydrological cycle.
Are inter‐model differences in AMIP‐II near surface air temperature means and extremes explained by land surface energy balance complexity?
Authors: Pitman A. J. , McAvaney B. J. , Bagnoud N. , Cheminat B.
Published: March 2004

We use the Atmospheric Model Intercomparison Project (AMIP‐II) experimental protocol to perform six ensemble simulations for four different modes of land surface energy balance complexity. We calculate the land‐only mean, minimum and maximum temperature variance for each ensemble and compare these with AMIP‐II results. We find no evidence that the surface energy balance complexity leads to systematic differences in the simulated mean, minimum or maximum temperature variance at the global scale, or in the zonal averages. We therefore conclude that the differences simulated by the AMIP‐II models cannot be attributed to variations in surface energy balance complexity. Our results indicate that the simulation of mean temperature variance and the variance of extreme temperature are not limited by uncertainties in how to parameterize the surface energy balance, a conclusion that adds confidence to the use of climate models for detection and attribution studies.
One million year old groundwater in the Sahara revealed by krypton‐81 and chlorine‐36
Authors: Sturchio N. C. , Du X. , Purtschert R. , Lehmann B. E. , Sultan M. , Patterson L. J. , Lu Z.‐T. , Müller P. , Bigler T. , Bailey K. , O'Connor T. P. , Young L. , Lorenzo R. , Becker R. , El Alfy Z. , El Kaliouby B. , Dawood Y. , Abdallah A. M. A.
Published: March 2004

Measurements of 81Kr/Kr in deep groundwater from the Nubian Aquifer (Egypt) were performed by a new laser‐based atom‐counting method. 81Kr ages range from ∼2 × 105 to ∼1 × 106 yr, correlate with 36Cl/Cl ratios, and are consistent with lateral flow of groundwater from a recharge area near the Uweinat Uplift in SW Egypt. Low δ2H values of the 81Kr‐dated groundwater reveal a recurrent Atlantic moisture source during Pleistocene pluvial periods. These results indicate that the 81Kr method for dating old groundwater is robust and such measurements can now be applied to a wide range of hydrologic problems.
A relationship between timing of El Niño onset and subsequent evolution
Authors: Horii Takanori , Hanawa Kimio
Published: March 2004

A relationship between the timing of El Niño onset and the subsequent evolution is examined, using 130‐year long time series of Niño‐3.4 index from 1871 to 2000. It is found that El Niño events can be classified into two major types: one is the onset of which is from April to June (spring type) and the other is from July to October (summer‐fall type). Here, the duration of El Niño is defined as the period when the 5‐month running mean anomaly of Niño‐3.4 index is exceeding 0.5°C. As a result, 24 El Niño events are identified, and classified into 10 spring type events and 14 summer‐fall type events. In general, spring type events grow greater in magnitude, and take the mature phase around a boreal winter and the evolution is relatively regular. On the contrary, summer‐fall type events are relatively weaker in magnitude, and have rather irregular aspects.
Ionosphere gives size of greatest solar flare
Authors: Thomson Neil R. , Rodger Craig J. , Dowden Richard L.
Published: March 2004

On 4 November 2003, the largest solar flare ever recorded saturated the GOES X‐ray detectors; from these a magnitude of X28 (2.8 mW/m2) has been extrapolated (http://sec.noaa.gov/weekly/pdf/prf1471.pdf). However, using the Earth's ionosphere as a giant X‐ray detector, we show the magnitude of this flare is consistent with X45 ± 5 (4.5 ± 0.5 mW/m2), or more than twice that of the two previously recorded largest flares, both about X20. This flare magnitude is determined by using the large observed phase changes recorded at Dunedin, New Zealand, on long VLF radio paths across the Pacific from transmitters in the continental USA and Hawaii. The enhanced X‐ray flux caused a dramatic lowering of the height of the D‐region of the ionosphere, allowing the flare to be measured relative to the GOES observations.
Exploratory studies of silicate melt structure at high pressures and temperatures by in situ X‐ray diffraction
Authors: Funamori Nobumasa , Yamamoto Shino , Yagi Takehiko , Kikegawa Takumi
Published: March 2004

We have developed synchrotron X‐ray diffraction techniques for studying the structure of silicate melts and have applied them to measuring the structures of MgSiO3 and CaSiO3 melts up to 6 GPa. In both melts, it appears that the changes in the local structure around the divalent ions and in the network structure of SiO4 tetrahedra are the dominant compression mechanisms while a change in the local structure around the Si ion is a secondary mechanism up to at least 6 GPa. The structural changes appear to be larger in CaSiO3 melt than in MgSiO3 melt, especially in the vicinity of ambient pressure. These results are consistent with available experimental and theoretical information on MgSiO3 and CaSiO3, and explain discrepancies in previous work.
Frazil ice formation in an ice shelf water plume
Authors: Smedsrud Lars H. , Jenkins Adrian
Published: March 2004

We present a model for the growth of frazil ice crystals and their accumulation as marine ice at the base of Antarctic ice shelves. The model describes the flow of buoyant water upward along the ice shelf base and includes the differential growth of a range of crystal sizes. Frazil ice formation starts when the rising plume becomes supercooled. Initially, the majority of crystals have a radius of ∼0.3 mm and concentrations are below 0.1 g/L. Depending on the ice shelf slope, which controls the plume speed, frazil crystals increase in size and number. Typically, crystals up to 1.0 mm in radius are kept in suspension, and concentrations reach a maximum of 0.4 g/L. The frazil ice in suspension decreases the plume density and thus increases the plume speed. Larger crystals precipitate upward onto the ice shelf base first, with smaller crystals following as the plume slows down. In this way, marine ice is formed at rates of up to 4 m/yr in some places, consistent with areas of observed basal accumulation on Filchner‐Ronne Ice Shelf. The plume continues below the ice shelf as long as it is buoyant. If the plume reaches the ice front, its rapid rise produces high supercooling and the ice crystals attain a radius of several millimeters before reaching the surface. Similar ice crystals have been trawled at depth north of Antarctic ice shelves, but otherwise no observations exist to verify these first predictions of ice crystal sizes and volumes.
Storm‐induced sediment gravity flows at the head of the Eel submarine canyon, northern California margin
Authors: Puig P. , Ogston A. S. , Mullenbach B. L. , Nittrouer C. A. , Parsons J. D. , Sternberg R. W.
Published: March 2004

As part of the STRATAFORM program, a bottom‐boundary layer (BBL) tripod was deployed at 120 m depth in the northern thalweg of the Eel Canyon during winter 2000. Increases of the near‐bottom suspended‐sediment concentrations (SSC) recorded at the canyon head were not directly related to the Eel River discharge, but were clearly linked to the occurrence of storms. BBL measurements revealed that during intensifications of the wave orbital velocity, sediment transport at the head of the canyon occurred as sediment gravity flows directed down‐canyon. Observational evidence for near‐bed sediment gravity‐flow transport included an increase toward the bed of the down‐canyon component of wave‐averaged velocity and high estimated SSC. At higher sampling frequencies (1 Hz), the current components during these events fluctuated at the same periodicity as the pressure, reflecting a clear influence of the surface‐wave activity on the generation and maintenance of the sediment gravity flows. The origin of such flows is not related to the formation of fluid muds on the shelf or to intense wave‐current sediment resuspension around the canyon head region. Rather, liquefaction of sediment deposited at the head of the canyon (induced by wave‐load excess pore water pressures during storms) combined with elevated slopes around the canyon head appear to be the mechanisms initiating sediment transport. The resulting fluidized‐sediment layer can easily be eroded, entrained into the water column, and transported down‐canyon as a sediment gravity flow. Results from this study reveal that storm‐induced sediment gravity flows occur periodically in the Eel Canyon head, and suggest that this kind of sediment transport process can occur in other submarine canyons more frequently than previously expected.
Analysis of apparent optical properties and ocean color models using measurements of seawater constituents in New England continental shelf surface waters
Authors: Green Rebecca E. , Sosik Heidi M.
Published: March 2004

We used budgets of absorption (a), scattering (b), and backscattering (bb) for particles and chromophoric dissolved organic matter (CDOM) to investigate sources of seasonal variations in apparent optical properties (AOPs) of New England continental shelf surface waters. Spectral a, b, and bb budgets for particles were estimated from flow cytometric measurements of eukaryotic pico/nanophytoplankton, Synechococcus, heterotrophic prokaryotes, detritus, and minerals; AOPs were modeled with Hydrolight radiative transfer software. For late summer and spring, our modeled values of the diffuse attenuation coefficient (Kd) and remote sensing reflectance (Rrs) were on average within 15% and 9%, respectively, of independent measurements. This close agreement allowed us to examine how different seawater constituents contributed to AOP variability. Higher values of Kd in the spring, compared to summer, were due to higher absorption by eukaryotic phytoplankton (aeuk) and CDOM (aCDOM), which coincided with higher nutrient levels and less stratified conditions than in the summer. Differences in the spectral shape of Rrs between the seasons were caused by a combination of differences in aeuk, aCDOM, and bb from non‐phytoplankton particles (minerals and detritus combined). For non‐phytoplankton bb the major seasonal difference was a higher inverse wavelength dependence in the summer due to the effects of small organic detritus. We applied two semianalytical ocean color models to our data, in order to evaluate whether the assumptions and parameterizations inherent in these models are applicable for New England shelf waters. We show how differences between observed and modeled chlorophyll a specific phytoplankton absorption, aCDOM, and non‐phytoplankton bb cause errors in chlorophyll a concentration and IOPs retrieved from reflectance inversion models.