bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium and strontium thiosulfate, CaS2O3·6H2O and SrS2O3·5H2O
Authors: Held Peter , Bohatý Ladislav
Published: October 2004

In contrast to former morphological studies, the results presented here show that calcium(II) thiosulfate hexahydrate, CaS2O3·6H2O, crystallizes centrosymmetrically in the pinacoidal class (point group \overline 1). The structure is characterized by chains, parallel to [100], of alternating S2O3 and Ca(H2O)6O2 groups sharing common O atoms. The composition of each chain link is [Ca(H2O)6(S2O3)]. The geometry is analysed and compared in detail with the structural features of monoclinic strontium(II) thiosulfate pentahydrate, SrS2O3·5H2O, which forms layers, parallel to (100), of alternating S2O3 and Sr(H2O)4O5 groups connected via common O atoms and O–O edges. Each layer contains [Sr(H2O)3O(S2O3)]∞ as the unique repeat unit.
2-[6-(3-Chlorophenyl)-2,4-dioxoperhydropyrimidin-3-yl]ethyl morpholine-4-carbodithioate
Authors: Köysal Yavuz , Işık Şamil , Septiog~lu Ebubekir , Çalış Ünsal
Published: October 2004

In the title compound, C17H20ClN3O3S2, the hexahydropyrimidine ring is puckered, the total puckering amplitude Q

T
being 0.41 (1) Å. The morpholine ring displays orientational disorder. Molecules are linked in the crystal via N—H...O and C—H...O interactions to form infinite chains.
catena-Poly[[(nitrato-κ2
O,O′)silver(I)]-μ-2,2′-[1,4-phenylenebis(methylenethio)]bis(5-methyl-1,3,4-thiadiazole)-κ2
N
3:N
3′]
Authors: Zheng Yan
Published: October 2004

In the title complex, [Ag(NO3)(C14H14N4S4)]
n
, the AgI atom lies on a twofold axis and shows a distorted tetrahedral coordination, comprised of two N-atom donors from two thiadiazole groups of separate ligands and two O-atom donors from one nitrate ligand. Each bis(thioether) ligand also lies on a twofold axis and bridges two adjacent Ag atoms to form an infinite chain along the c axis, with an Ag...Ag separation of 11.462 (4) Å. Adjacent one-dimensional chains are further linked into double-chain motifs through weak Ag...S and π–π stacking interactions.
1H-Imidazol-1-yl 1,2,3,4-tetrahydroisoquinolin-2-yl ketone
Authors: Grzyb Justyna A. , Lough Alan J. , Batey Robert A.
Published: October 2004

In the crystal structure of the title compound, C13H13N3O, the C—Nimidazole bond length of 1.431 (3) Å is shorter than that observed [1.466 (6) Å] in the corresponding carbamoylimidazolium salt 3-methyl-1-(1,2,3,4-tetrahydroisoquinolin-2-ylcarbonyl)imidazolium iodide. A comparision of these compounds is used to highlight the structural differences that occur as a result of the imidazolium effect. Weak C—H...O hydrogen bonds link molecules into extended tapes in the a direction.
Dicarbonyl(tropolonato)rhodium(I), a redetermination
Authors: Steyl Gideon , Kruger Gert J. , Roodt Andreas
Published: October 2004

The molecules of the title complex, [Rh(Trop)(CO)2] (Trop is 2-hydroxycyclohepta-2,4,6-trienonate, C7H5O2), exhibit symmetrical but non-crystallographic square-planar molecular geometry, with Rh—C distances of 1.825 (10) and 1.826 (9) Å, Rh—O distances of 2.021 (5) and 2.032 (5) Å, and an O—Rh—O bite angle of 79.4 (2)°. Strong Rh...Rh and Rh...C intermolecular interactions of 3.683 (3) and 3.650 (5) Å, respectively, are also observed.
Dibromotetra-μ3-methoxo-di-μ2-methoxo-hexakis(tetrahydrofuran-d
8)tetramagnesium
Authors: Walfort Bernhard , Yousef Rushdi I. , Rüffer Tobias , Steinborn Dirk
Published: October 2004

The crystal structure of the title compound, [Mg4Br2(CH3O)6(C4D8O)6], consists of discrete molecules with imposed symmetry C

i
. The tetranuclear compound exhibits two crystallographically independent Mg atoms having distorted octahedral and trigonal–bipyramidal coordination spheres. The Mg atoms are bridged by two μ3-OMe and four μ2-OMe ligands, and their coordination is completed by two terminal Br and six tetrahydrofuran ligands.
(+)-Camphoracetic acid: catemeric hydrogen bonding in a γ-keto acid
Authors: Thompson Hugh W. , Coté Marie L. , Lalancette Roger A.
Published: October 2004

The title compound, (1R)-4,7,7-trimethyl-3-oxobicyclo[2.2.1]heptane-2-endo-acetic acid, C12H18O3, like its lower homolog, forms carboxyl-to-ketone hydrogen-bonding catemers (Z′ = 2) [O...O = 2.729 (5) and 2.707 (5) Å, and O—H...O = 165 and 170°] with screw-related components. The two molecules of the asymmetric unit differ slightly in conformation and produce two counter-aligned hydrogen-bonding chains, both aligned with the b axis. Close intermolecular C—H...O=C contacts exist for the ketone group of one molecule and for both the ketone and carboxyl functions in the other.
Tetrakis(2,2′-bipyridine-κ2
N,N′)tetrakis(μ-salicylato-κ3
O,O′:O′′)-quadro-tetrazinc(II) decahydrate
Authors: Wang Yue , Odoko Mamiko , Okabe Nobuo
Published: October 2004

The title compound, [Zn4(C7H4O3)4(C10H8N2)4]·10H2O, crystallizes as a centrosymmetric tetranuclear cyclic complex containing four ZnII atoms bridged by four carboxylate groups from salicylate ligands, with a syn–anti configuration. Each ZnII atom has a distorted trigonal–bipyramidal coordination geometry, formed by two N atoms of a 2,2′-bipyridine ligand and three O atoms from two salicylate ligands. The complex is stabilized by intramolecular π–π interactions between pairs of bipyridine rings and a 16-membered gear-wheel-shaped cyclic framework. The hydrogen-bonding network is formed via the water molecules.
A new binding mode for thiosulfate in six-coordinate poly[[(1,10-phenanthroline-κ2
N,N′)cadmium(II)]-μ-thiosulfato]
Authors: Díaz de Vivar M. Enriqueta , Baggio Sergio , Baggio Ricardo
Published: October 2004

In the novel title six-coordinate cadmium complex, [Cd(S2O3)(C12H8N2)]
n
, the anion binds to three different six-coordinate cationic centres through all four external atoms, an unprecedented coordination mode for thiosulfate metal-organic complexes. This connectivity leads to strongly linked dimers, connected to form interleaved double chains, which in turn interact through remarkably short π–π bonds between their phenanthroline groups.
1,4-Dimethylpyridinium hexakis(dimethylformamide-κO)calcium(II) dodecamolybdophosphate
Authors: Tan Xue-Jie , Sun Si-Xiu , Ma Jian-Ping , Liu Lian-Dong , Dong Yu-Bin , Yu Wen-Tao , Xing Dian-Xiang
Published: October 2004

In the title compound, (C7H10N)[Ca(C3H7NO)6][PMo12O40], two types of cations {viz. 1,4-dimethylpyridinium and a [Ca(DMF)6]2+ complex cation (DMF is dimethylformamide)} and dodecamolybdophosphate (tetracontaoxophosphidododecamolybdate) anions form an infinite three-dimensional assembly via electrostatic forces.
Diaqua(sulfato-κO)[2,4,6-tris(2-pyridyl)-1,3,5-triazine-κ3
N
1,N
2,N
6]zinc(II) dihydrate
Authors: Harvey Miguel Angel , Baggio Sergio , Baggio Ricardo
Published: October 2004

In the title compound, [Zn(SO4)(C18H12N6)(H2O)2]·2H2O, the metal complex is monomeric, with an octahedral ZnII centre coordinated by the tridentate ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tpt), two aqua molecules and a monodentate sulfate ion. A complex hydrogen-bonding scheme is built up out of the profuse availability of donors and acceptors (O—H...O/N and C—H...O) which, in addition to π–π interactions between tpt groups, define a three-dimensional assembly.
Poly[manganese(II)-μ2-benzidine-κ2
N:N′-μ3-biphenyl-2,2′-dicarboxylato-κ4
O:O′,O′′:O′′′]
Authors: Jiang Min , Li Jun , Zhang Feng-Xing
Published: October 2004

The title compound, [Mn(C14H8O4)(C12H12N2)]
n
, with a novel three-dimensional framework, has been prepared by a hydrothermal reaction at 433 K. Each Mn atom lies on a twofold axis in a slightly distorted octahedral geometry, coordinated by two N atoms from two benzidine ligands and four O atoms from three symmetry-related biphenyl-2,2′-dicarboxylate (bpdc) ligands. The benzidine ligands lie about inversion centres and the bpdc ligands about twofold axes. Each bpdc ligand is bonded to three Mn ions to form a continuous chain of metal ions. The bpdc ligands are accommodated in a series of distorted holes resembling hexagonal prisms.
Hydrogen-bonded chains in 5-methyl-2-trifluoromethyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one and hydrogen-bonded chains of rings in 5-amino-3-trifluoromethyl-1H-1,2,4-triazole–5-methyl-2-trifluoromethyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one (1/1), the co-crystal of a reaction product and one of its precursors
Authors: Boechat Nubia , Dutra Karen D. B. , Valverde Alessandra L. , Wardell Solange M. S. V. , Low John N. , Glidewell Christopher
Published: October 2004

In the title compounds, C7H5F3N4O, (I), and C3H3F3N4·C7H5F3N4O, (II), all of the molecular components exhibit some polarization of their molecular–electronic structures. The molecules in (I) are linked into simple C(6) chains, while in (II), the components are linked by a combination of two-centre N—H...N and N—H...O, and three-centre N—H...(O,N) hydrogen bonds into chains containing R{_1^2}(5), R{_2^1}(6) and R{_2^2}(8) rings.
Bis[1,3-bis(trimethylsilyl)allyl]cobalt(II), a stable electron-deficient allyl complex
Authors: Smith J. Dominic , Quisenberry Keith T. , Hanusa Timothy P. , Brennessel William W.
Published: October 2004

The title compound, bis[(1,2,3-η)-(2E)-1,3-bis(trimethylsilyl)prop-2-enyl]cobalt(II), [Co(C9H21Si2)2], is a homoleptic allyl complex with η3-bound ligands. The Co—C distances range from 1.996 (3) to 2.096 (3) Å and the allyl ligands adopt staggered, nearly parallel, arrangements around the Co atom. The trimethylsilyl groups are in syn–anti conformations; the steric shielding they provide to the metal is probably responsible for the thermal stability of the compound.
Polysulfonylamines. CLXXI. [Di(methanesulfonyl)amido-κN]bis(2-picoline-κN)copper(I)
Authors: Jones Peter G. , Zerbe Eva-Maria , Wölper Christoph
Published: October 2004

The title compound, [Cu(C2H6NO4S2)(C6H7N)2], consists of monomeric molecules in which the Cu atom displays planar but irregular coordination by three N-atom donors; Cu—N = 2.1054 (12) (amide N), 1.9514 (12) and 1.9589 (12) Å, and N—Cu—N = 141.24 (5), 111.54 (5) and 107.20 (5)°. Intramolecular Cu...O contacts are observed. The packing involves (interconnected) layer formation via C—H...O interactions in two directions, three hydrogen bonds combining to form layers parallel to (101) and five to form layers parallel to (10\overline 2).
(±)-(4-Oxo-4H-chromen-2-yl)(phenyl)methyl acetate
Authors: Małecka Magdalena , Massa Werner , Budzisz Elżbieta
Published: October 2004

The title compound, C18H14O4, forms a supramolecular structure via π–π stacking and weak C—H...O and C—H...π interactions. The benzopyran moiety is almost planar. The benzene ring of the phenylmethyl acetate substituent is nearly perpendicular to the fused benzene and pyran rings and also to the methyl acetate group.
Bis(μ-2-aminopyridine)bis[(trifluoroacetato)silver(I)]
Authors: You Zhong-Lu , Zhu Hai-Liang
Published: October 2004

The title compound, [Ag2(C2F3O2)2(C5H6N2)2], is a dinuclear AgI complex with inversion symmetry. Each Ag atom is three-coordinated by two N atoms from two different 2-aminopyridine ligands and by one O atom from a trifluoroacetate anion, giving an approximately trigonal coordination environment. In the crystal packing, molecules are connected by N—H...O and N—H...F hydrogen bonds, forming layers parallel to the (001) plane.
Aquadichloro(di-2-pyridyldiazene)copper(II) monohydrate
Authors: Uçar İbrahim , Arslan Figen , Bulut Ahmet , İçbudak Hasan , Ölmez Halıs , Büyükgüngör Orhan
Published: October 2004

The crystal structure of the mononuclear title complex, [CuCl2(C10H8N4)(H2O)]·H2O, shows an s-cis/E/s-trans-configured di-2-pyridyldiazene ligand, with the square-pyramidal CuII ion coordinated to one pyridyl and one diazene N atom together with two Cl atoms and one aqua ligand. The crystal packing involves both hydrogen-bonding and π–π interactions. The solvent water molecule links three monomers to one another through hydrogen-bonding interactions in which two monomers are linked via chloro ligands and the third via the aqua ligand. Face-to-face and weak slipped π–π interactions also occur between di-2-pyridyldiazene moieties, and these interactions are responsible for the interchain packing.
[Cu(phen)2(μ-IDA)Cu(phen)](ClO4)2·CH3OH: tridentate and monodentate binding to two copper(II) species by a bridging ligand
Authors: Wei Yi-Bin , Yuan Cai-Xia , Yang Pin
Published: October 2004

The stoichiometric reaction of 1,10-phenanthroline (phen), iminodiacetic acid (IDA-H2) and Cu(ClO4)2 in a H2O–CH3OH (2:1) solution yields μ-iminodiacetato-2:1κ4
O,N,O′:O′′-tris(1,10-phenanthroline)-1κ4
N,N′;2κ2
N,N′-dicopper(II) diperchlorate methanol solvate, [Cu2(C4H5NO4)(C12H8N2)3](ClO4)2·CH3OH. The IDA ligand bridges the two CuII ions via a carboxylate group and uses one further N and an O atom of the second carboxylate group to complete a fac-tridentate coordination at one Cu centre. A phen ligand completes a distorted square-pyramidal coordination at this metal atom, although there is weak coordination by a perchlorate O atom at a sixth position. The second Cu centre has a distorted trigonal–bipyramidal coordination to two phen moieties and a carboxylate O atom.
4-Nitroanilinium nitrate
Authors: Perpétuo Genivaldo Julio , Janczak Jan
Published: October 2004

The crystal structure of the title compound, C6H7N2O2
+·NO3
−, is built up from 4-nitroanilinium cations and nitrate anions. The NO2 group is coplanar with the aryl ring, which shows significant distortion from the ideal hexagonal form. The NO3
− anion is planar but shows distortion from the C
3h
symmetry that is predicted by molecular orbital calculations. Two of the three O atoms of the NO3 group are involved in hydrogen bonds as acceptors.
A novel one-dimensional zigzag coordination polymer of copper(II) with dimethylglyoxime
Authors: Zhang Baofeng , Liu Xuanwen , Wang Xiaoqing , Wang Ruji , Xie Chengzhi , Shen Guangqiu , Shen Dezhong
Published: October 2004

A novel metal-organic based polymeric complex, namely catena-poly[[bis(μ4-dimethylglyoximato)bis(μ2-dimethylglyoximato)bis(dimethylglyoxime)tetracopper(II)] diperchlorate dihydrate], {[Cu4(dmg)2(Hdmg)2(H2dmg)2](ClO4)2·2H2O}∞ (H2dmg is dimethylglyoxime, C2H8N2O2), has been synthesized and characterized by single-crystal X-ray diffraction methods. The complex is a one-dimensional zigzag chain coordination polymer, in which the tetranuclear repeat unit is a centrosymmetric Cu4 moiety coordinated to dimethylglyoxime ligands only. These units are linked by double Cu—O—Cu bridges in a centrosymmetric rectangular junction.
Di-μ-hydroxo-bis[aqua(1,10-phenanthroline-κ2
N,N′)copper(II)] trans-bis(2-{[(E)-5-formyl-2-oxido-κO-benzylidene]amino-κN}ethanesulfonato(2–))copper(II) hexahydrate
Authors: Jiang Yi-Min , Zeng Ju-Lan , Yu Kai-Bei
Published: October 2004

The title compound, [Cu2(OH)2(C12H8N2)2(H2O)2][Cu(C10H9NO5S)2]·6H2O, is comprised of a copper-centred complex cation and a copper-centred complex anion; the cation lies about an inversion centre and in the anion the Cu atom lies on an inversion centre. In the doubly charged bridged dicopper cation, each Cu centre has distorted square-pyramidal geometry. In the square-planar dianion, two sulfonate ligands are trans coordinated to the Cu atom via a deprotonated hydroxyl O atom and an imine N atom, forming two six-membered chelate rings. The structure is stabilized by an extensive hydrogen-bond system and aromatic-ring stacking interactions.
A two-dimensional manganese(II) coordination polymer: poly[[diaquamanganese(II)]-μ-4,4-bipyridine-κ2
N:N′-μ-(p-phenylenedioxydiacetato)-κ2
O:O′]
Authors: Gao Shan , Liu Ji-Wei , Huo Li-Hua , Zhao Hui , Zhao Jing-Gui
Published: October 2004

In the title two-dimensional coordination polymer, [Mn(1,4-BDOA)(4,4-bipy)(H2O)2]
n
[1,4-BDOA2− is the p-phenylenedioxydiacetate dianion (C10H8O6) and 4,4-bipy is 4,4-bipyridine (C10H8N2)], each MnII atom displays octahedral coordination by two O atoms of the 1,4-BDOA2− groups, two N atoms of the 4,4-bipy ligands and two solvent water molecules. The MnII atom, 4,4-bipy ligand and 1,4-BDOA2− group occupy different inversion centres. Adjacent MnII atoms are bridged by 1,4-BDOA2− groups and 4,4-bipy ligands, forming a two-dimensional network with Mn...Mn separations of 11.592 (2) and 11.699 (2) Å. Hydrogen bonds from a water O—H group link the layers in the third dimension.
L-Seryl-L-phenylalanine
Authors: Helle Ina Høydal , Løkken Camilla Victoria , Görbitz Carl Henrik , Dalhus Bjørn
Published: October 2004

The peptide bond in the crystal structure of the title compound, C8H16N2O4, deviates substantially from planarity in the same manner as in other L-Ser-L-Xaa dipeptides, where Xaa is a hydrophobic residue.
The 1:1 adduct of 5-methylbenzene-1,3-diol (orcin) and 1,4-diazabicyclo[2.2.2]octane
Authors: Jin Zhi-Min , Lin Chen-Shui , Wang Hai-Bin , Hu Mao-Lin , Shen Liang , Huang Liang-Ren
Published: October 2004

In the title adduct, C6H12N2·C7H8O2, the orcin and 1,4-diazabicyclo[2.2.2]octane moieties are held together by O—H...N hydrogen bonds. One-dimensional chiral hydrogen-bonded chains are formed along the b axis. Neighbouring chains are held together principally by van der Waals interactions and are interrelated by translation, resulting in a chiral layer.
Regional Differences in Neurogenic Signal Transduction Pathway of Cholera Toxin‐Induced Fluid, Electrolyte and Serotonin Accumulation in the Porcine Jejunum
Authors: Berggreen Paul , Grøndahl Marie Louise , Ersbøll Anette Kjær , Maltbæk Jørgen Strange , Thorbøll Jens Erik , Skadhauge Erik , Hansen Mark Berner
Published: October 2004

Serotonin, acetylcholine and substance P are mediators involved in the secretory response to cholera toxin in the small intestine. The aim of this study was to investigate the regional difference in the effect of a serotonin receptor type 3 antagonist (ondansetron), a nicotinic receptor antagonist (hexamethonium), and a substance P antagonist (the neurokinin receptor type 1 antagonist, CP 99,994) on the cholera toxin‐induced fluid accumulation in the porcine jejunum. A dose‐range of cholera toxin (0.32–56.00 μg/loop) was instilled for 4 hr in ligated loops in two regions of the proximal jejunum in 6–8‐week‐old pigs. Ondansetron (200 μg/kg), hexamethonium (10 mg/kg), CP 99,994 (1 mg/kg), or saline alone (control) were given intravenously 10 min. before cholera toxin instillation. Cardiovascular parameters, blood gas data, net fluid accumulation, serotonin and electrolyte concentration in the accumulated fluid were measured. Cardiovascular and blood gas parameters were within the normal range in all treatments. The apparent maximal response in fluid accumulation was reduced 20% in case of ondansetron, and by 33% using CP 99,994 in the aboral region compared to control, whereas no effect was observed in the oral region. Hexamethonium reduced the apparent maximal secretory response in both the oral and aboral regions by 45%. None of the treatments with antagonists changed the luminal content of serotonin or the electrolyte concentrations in the accumulated fluid. The results demonstrate that the involvement of serotonin receptor type 3 and neurokinin type 1 receptors in the transductional pathway of cholera toxin‐induced fluid accumulation vary significantly within the jejunum, while the cholinergic (nicotinic) transmission plays an even role.
Protective Role of Metallothionein on DNA Damage in Rat Kidney Caused by Cis‐Diamminedichloroplatinum
Authors: Hosokawa Toshiyuki , Okabe Masashi , Saito Shigeru , Saito Takeshi , Kurasaki Masaaki
Published: October 2004

Cis‐diamminedichloroplatinum (cis‐DDP) has been used as an anticancer agent but it also causes nephrotoxicity. To study the cis‐DDP metabolism and its effects, the induction of metallothioneins and DNA damage caused by cis‐DDP were observed. Cis‐DDP or trans‐DDP was administered to seven‐week‐old Wistar male rats as three daily injections of 8.0 mg/kg body wt., intraperitoneally. Using the obtained kidneys, gel filtration assay, metal analysis, immunohistochemistry and terminal deoxy transferase‐mediated deoxy uracil triphosphate nick end labeling (TUNEL) method were carried out to examine localization of metallothioneins and DNA damage caused by cis‐DDP. Platinum (Pt) contents, 26.05±12.01 μg/g body wt. and 51.29±4.59 μg/g body wt. (average±S.E.) were detected in the kidney of rats injected with both cis‐ and trans‐DDP, respectively. Metallothionein was detected in the cortex of the kidney in rats administrated cis‐DDP or trans‐DDP. The mRNA was also detected in the same region. On the other hand cis‐DDP showed induction of DNA damage on the cells in the outer stripe of the outer medulla but trans‐DDP did not show any damage. The region‐induced DNA damage differed from that induced by metallothioneins. Cis‐DDP is suggested to be mainly trapped at the proximal tubules by metallothioneins, and the rest of cis‐DDP induces DNA damage at the outer stripe of the outer medulla. Metallothioneins are considered to contribute to the protection against cis‐DDP in the rat cortex.
Amiodarone for Rapid Cardioversion of Chronic Atrial Tachyarrhythmia?
Authors: Nielsen Klaus Damkjær , Møller Søren
Published: October 2004

Electrical cardioversion of atrial tachyarrhythmia has disadvantages, such as the need for general anaesthesia, skin burns and thoracic pain. Pharmacodynamic cardioversion is without these side effects, but the reports of the efficacy of the treatment vary a lot. Amiodarone has been the only drug so far reported to give a combination of high efficacy and low frequency of serious side effects such as ventricular tachycardia and shock. The purpose of the present study was to assess the effect of amiodarone on chronic atrial tachycardia. Seventeen patients with chronic atrial fibrillation or flutter were given an oral dose of 30 mg/kg amiodarone. Serial blood tests after amiodarone ingestion were taken to document absorption. Patients, who did not convert to sinus rhythm within 24 hr were treated by electrical cardioversion. No patients converted pharmacodynamically to sinus rhythm. Twelve patients (71%) reached the recommended serum concentration of amiodarone (2–2.5 mg/l, median 2.4 mg/l, range 0.96–4.7). The concentration of desethylamiodarone remained low (<0.2 mg/l), and there were no objective or subjective side effects following the treatment. Sixteen patients (94%) were converted to sinusrhythm the day after by electrical cardioversion without complications. A single high dose of amiodarone is a safe but ineffective method of converting chronic atrial fibrillation and flutter, and may be used as adjuvant therapy in combination with electrical cardioversion.
Associations between carbon isotope ratios of ecosystem respiration, water availability and canopy conductance
Authors: McDowell N. G. , Bowling D. R. , Schauer A. , Irvine J. , Bond B. J. , Law B. E. , Ehleringer J. R.
Published: October 2004

We tested the hypothesis that the stable carbon isotope signature of ecosystem respiration (δ13CR) was regulated by canopy conductance (Gc) using weekly Keeling plots (n=51) from a semiarid old‐growth ponderosa pine (Pinus ponderosa) forest in Oregon, USA. For a comparison of forests in two contrasting climates we also evaluated trends inδ13CRfrom a wet 20‐year‐old Douglas‐fir (Pseudotsuga menziesii) plantation located near the Pacific Ocean. Intraannual variability inδ13CRwas greater than 8.0‰ at both sites, was highest during autumn, winter, and spring when rainfall was abundant, and lowest during summer drought. Theδ13CRof the dry pine forest was consistently more positive than the wetter Douglas‐fir forest (mean annualδ13CR: −25.41‰ vs. −26.23‰, respectively,P=0.07). At the Douglas‐fir forest,δ13CR–climate relationships were consistent with predictions based on stomatal regulation of carbon isotope discrimination (Δ). Soil water content (SWC) and vapor pressure deficit (vpd) were the most important factors governingδ13CRin this forest throughout the year. In contrast,δ13CRat the pine forest was relatively insensitive toSWCorvpd, and exhibited a smaller drought‐related enrichment (∼2‰) than the enrichment observed during drought at the Douglas‐fir forest (∼5‰). Groundwater access at the pine forest may buffer canopy–gas exchange from drought. Despite this potential buffering,δ13CRat the pine forest was significantly but weakly related to canopy conductance (Gc), suggesting thatδ13CRremains coupled to canopy–gas exchange despite groundwater access. During drought,δ13CRwas strongly correlated with soil temperature at both forests. The hypothesis that canopy‐level physiology is a critical regulator ofδ13CRwas supported; however, belowground respiration may become more important during rain‐free periods.
Divergent pheromone‐mediated insect behaviour under global atmospheric change
Authors: Mondor Edward B. , Tremblay Michelle N. , Awmack Caroline S. , Lindroth Richard L.
Published: October 2004

While the effects of global atmospheric changes on vegetation and resulting insect populations(‘bottom‐up interactions’) are being increasingly studied, how these gases modify interactions among insects and their natural enemies (‘top‐down interactions’) is less clear. As natural enemy efficacy is governed largely by behavioural mechanisms, altered prey finding and prey defence may change insect population dynamics. Here we show that pheromone‐mediated escape behaviours, and hence the vulnerability of insects to natural enemies, are divergent under atmospheric conditions associated with global climate change. Chaitophorus stevensis, a common aphid on trembling aspen trees, Populus tremuloides, have diminished escape responses in enriched carbon dioxide (CO2) environments, while those in enriched ozone (O3) have augmented escape responses, to alarm pheromone. These results suggest that divergent pheromone‐mediated behaviours could alter predator–prey interactions in future environments.
Paired comparisons of carbon exchange between undisturbed and regenerating stands in four managed forests in Europe
Authors: Kowalski Andrew S. , Loustau Denis , Berbigier Paul , Manca Giovanni , Tedeschi Vanessa , Borghetti Marco , Valentini Riccardo , Kolari Pasi , Berninger Frank , Rannik Üllar , Hari Pertti , Rayment Mark , Mencuccini Maurizio , Moncrieff John , Grace John
Published: October 2004

The effects of harvest on European forest net ecosystem exchange (NEE) of carbon and its photosynthetic and respiratory components (GPP (gross primary production) and TER (total ecosystem respiration)) were examined by comparing four pairs of mature/harvested sites in Europe via a combination of eddy covariance measurements and empirical modeling. Three of the comparisons represented high coniferous forestry (spruce in Britain, and pines in Finland and France), while a coppice‐with‐standard oak plantation was examined in Italy.

While every comparison revealed that harvesting converted a mature forest carbon sink into a carbon source of similar magnitude, the mechanisms by which this occurred were very different according to species or management practice. In Britain, Finland, and France the annual sink (source) strength for mature (clear‐cut) stands was estimated at 496 (112), 138 (239), and 222 (225) g C m−2, respectively, with 381 (427) g C m−2 for the mature (coppiced) stand in Italy. In all three cases of high forestry in Britain, Finland, and France, clear‐cutting crippled the photosynthetic capacity of the ecosystem – with mature (clear‐cut) GPP of 1970 (988), 1010 (363), and 1600 (602) g C m−2– and also reduced ecosystem respiration to a lesser degree – TER of 1385 (1100), 839 (603), and 1415 (878) g C m−2, respectively. By contrast, harvesting of the coppice oak system provoked a burst in respiration – with mature (clear‐cut) TER estimated at 1160 (2220) gC m−2– which endured for the 3 years sampled postharvest. The harvest disturbance also reduced GPP in the coppice system – with mature (clear‐cut) GPP of 1600 (1420) g C m−2– but to a lesser extent than in the coniferous forests, and with near‐complete recovery within a few years. Understanding the effects of harvest on the carbon balance of European forest systems is a necessary step towards characterizing carbon exchange for timberlands on large scales.
Spatial and temporal variability in forest–atmosphere CO2 exchange
Authors: Hollinger D. Y. , Aber J. , Dail B. , Davidson E. A. , Goltz S. M. , Hughes H. , Leclerc M. Y. , Lee J. T. , Richardson A. D. , Rodrigues C. , Scott N.A. , Achuatavarier D. , Walsh J.
Published: October 2004

Seven years of carbon dioxide flux measurements indicate that a ∼90‐year‐old spruce dominated forest in Maine, USA, has been sequestering 174±46 g C m−2 yr−1 (mean±1 standard deviation, nocturnal friction velocity (u*) threshold >0.25 m s−1). An analysis of monthly flux anomalies showed that above‐average spring and fall temperatures were significantly correlated with greater monthly C uptake while above‐average summer temperatures were correlated with decreased net C uptake. Summer months with significantly drier or wetter soils than normal were also characterized by lower rates of C uptake. Years with above‐average C storage were thus typically characterized by warmer than average spring and fall temperatures and adequate summer soil moisture.

Environmental and forest–atmosphere flux data recorded from a second tower surrounded by similar forest, but sufficiently distant that flux source regions (‘footprints’), did not overlap significantly showed almost identical temperature and solar radiation conditions, but some differences in energy partitioning could be seen. Half‐hourly as well as integrated (annual) C exchange values recorded at the separate towers were very similar, with average annual net C uptake differing between the two towers by <6%. Interannual variability in net C exchange was found to be much greater than between tower variability. Simultaneous measurements from two towers were used to estimate flux data uncertainty from a single tower. Carbon‐flux model parameters derived independently from each flux tower data set were not significantly different, demonstrating that flux towers can provide a robust method for establishing C exchange model parameters.
Predictive genetic testing in young people: When is it appropriate?
Authors: Duncan RE
Published: October 2004

Abstract:  Predictive genetic testing is currently offered to adults for a range of conditions, even when there is no possibility of prophylaxis or treatment. However, similar testing in children and adolescents is advised against in international guidelines. Despite this, several authors have argued against the existing guidelines. Given the lack of empirical evidence, it is important that clinicians are aware not only of the guidelines, but also of the arguments in favour of such testing.
Management of tongue‐tie in children: A survey of paediatric surgeons in Australia
Authors: Brinkmann S , Reilly S , Meara JG
Published: October 2004

Objectives:  To explore the beliefs and practices of Australian surgeons regarding surgical intervention to release tongue‐tie and to determine the main referral sources. In addition, we aimed to ascertain if there were differences in beliefs and practices according to surgical specialty.

Methods:  Four hundred surgeons in three different surgical specialties were surveyed via questionnaire. Multiple choice response questions and open ended questions were used to explore beliefs and practices surrounding tongue‐tie assessment, management and follow up. The questionnaires were distributed by email (where available), followed by fax and mail.

Results:  A response rate of 80.8% (n = 323) was obtained. Of these, 236 (73%) reported they practised surgery to release tongue‐tie; 46% were oral and maxillofacial surgeons, 37% were plastic surgeons and 17% were paediatric general surgeons. Indications for surgical management and follow up varied according to surgical specialty. There was no clear consensus regarding clinical indicators for surgery or functional outcomes following surgery.

Conclusions:  It appears that until a prospective study designed to address some of the controversial issues outlined is undertaken, we will remain ignorant about the need for surgery to release tongue‐tie in children.
Pneumococcal meningitis in Western Australian children: Epidemiology, microbiology and outcome
Authors: King BA , Richmond P
Published: October 2004

Objectives:  Pneumococcal meningitis is now vaccine‐preventable but continues to cause high rates of neurological sequelae internationally. Population‐based epidemiology, outcome and microbiology data are necessary to target vaccination strategies. This study outlines these key areas for Western Australian children diagnosed 1990−2000.

Methods:  The charts of all rural and metropolitan children with International Classification of Disease 9 and 10 discharge codes of pneumococcal or streptococcal meningitis from the Health Department's Hospital Morbidity Data System were reviewed.

Results:  Over 10.5 years, 94 episodes were confirmed. The average annual incidence for children under 2 years was 13.45 per 100 000 and 0.66 per 100 000 for children 2 years or older. Indigenous children had an almost seven‐fold increased risk compared to non‐Indigenous (with 78.55 per 100 000 in the under two‐year Indigenous group). Eight children died and 24 of the survivors had neurological sequelae. Penicillin resistance occurred in four of 87 isolates. One quarter of the cohort qualify under the current Australian policy of vaccination of high‐risk children with seven‐valent conjugate (7vPCV) vaccine. Most isolates (49/58) were 7vPCV serotypes, however, Indigenous populations were less well‐covered (58.3% covered vs 91.3% of isolates from non‐Indigenous children). Indigenous coverage would be improved to 75% with 11‐valent conjugate vaccine.

Conclusions:  Indigenous children and those under 2 years are most affected by pneumococcal meningitis and remain primary vaccination targets. Three quarters of these children would not be protected by a policy of vaccination of only high‐risk children with 7vPCV − improved protection requires higher valencies for Indigenous populations and universal infant vaccination.
Pneumococcal meningitis: Clinical course and resource use in Western Australian children
Authors: King BA , Richmond P
Published: October 2004

Objectives:  Paediatric pneumococcal meningitis causes high rates of neurological sequelae and is presenting challenges due to the emergence of antibiotic resistance. Diagnosis can be difficult and management is frequently complicated and resource intensive. This population‐based study outlines the diagnosis, clinical course and initial resource use of Western Australian (WA) children diagnosed between 1990 and 2000.

Methods:  The charts of all rural and metropolitan children discharged from all WA hospitals with International Classification of Disease 9 and 10 codes of pneumococcal or streptococcal meningitis from the Health Department's Hospital Morbidity Data System were reviewed retrospectively.

Results:  Ninety‐four episodes of pneumococcal meningitis were confirmed (median age 12.4 months). Initial diagnosis was often difficult with a suggestive prodrome in less than one quarter of cases and a median of two reviews until diagnosis (range 1−7). The median duration of hospitalization was 11.6 days, 41.5% were admitted to the Intensive Care Unit (ICU), and 47.9% had seizures. There were eight related deaths and neurological sequelae occurred in 24. Initial hospitalization cost on average $A19 900. Penicillin resistance was first noted in 1993 and occurred in 4.6% of isolates. Most cases (84.5%) were caused by serotypes contained in the currently available seven‐valent conjugate vaccine.

Conclusions:  Pneumococcal meningitis is often difficult to diagnose, necessitates long and frequently complicated in‐patient stays and has high rates of neurological sequelae. It is possible to prevent most cases with new conjugate vaccines.
Head lice prevalence in primary schools in Victoria, Australia
Authors: Counahan M , Andrews R , Büttner P , Byrnes G , Speare R
Published: October 2004

Objectives:  To determine the prevalence of and assess risk factors associated with head lice infections (pediculosis) in children from government primary schools in Victoria, Australia.

Methods:  Between May and October 2001, children were selected by clustered random sampling of schools and classes, then examined for head lice using hair conditioner and a fine‐toothed head lice comb. There were 1838 children screened from 16 primary schools. Risk factors evaluated included metropolitan or rural residence, school class, gender and hair length.

Results:  Thirteen percent of children (239/1838) had an active infection (95% CI, 10.9−15.1) and 3.3% (61/1838) had an inactive infection (95% CI, 2.0−4.6). Prevalence of active pediculosis varied between schools from 0 to 28%. Our screening identified no more than one case per class in the majority of classes screened (58.5%). Females were 2.2 times more likely to have active infection than males (95% CI [1.7,2.9]) and there was no significant difference for the other risk factors investigated.

Conclusions:  Our study demonstrated the prevalence of head lice varied across Victoria and showed that risk factors commonly attributed to head lice infections did not hold true. Our findings support the premise that traditional ad hoc mass school‐based screening may not be the best use of resources when controlling head lice. We suggest a more pragmatic community‐based approach.
Oral glucose tolerance test in children and adolescents: Positives and pitfalls
Authors: Conwell LS , Batch JA
Published: October 2004

Objectives:  To describe the glycaemic status (assessed by an oral glucose tolerance test (OGTT)) and associated comorbidities in a cohort of Australian children and adolescents at risk of insulin resistance and impaired glucose homeostasis (IGH).

Methods:  Twenty‐one children and adolescents (three male, 18 female) (18 Caucasian, one Indigenous, two Asian) (20 obese, one lipodystrophy) referred to the Paediatric Endocrinology and Diabetes Clinic underwent a 2‐h OGTT with plasma glucose and insulin measured at baseline, + 60 and + 120 min. If abnormal, the OGTT was repeated.

Results:  The mean (SD) age was 14.2 (1.6) years, BMI 38.8 (7.0) kg/m2 and BMI‐SDS 3.6 (0.6). Fourteen patients had fasting insulin levels >21 mU/L. Type 2 diabetes mellitus was diagnosed in one patient, impaired glucose tolerance (IGT) in four patients and impaired fasting glycaemia (IFG) in one patient. Despite no weight loss, only one patient had a persistently abnormal OGTT on repeat testing. Three patients with IGH were medicated with risperidone at the time of the initial OGTT. One patient who had persistent IGT had continued risperidone. The other two patients had initial OGTT results of IGT and diabetes mellitus type 2. They both ceased risperidone between tests and repeat OGTT showed normal glycaemic status.

Conclusions:  Use of fasting glucose alone may miss cases of IGH. Diagnosis of IGT should not be made on one test alone. Interpretation of glucose and insulin responses in young people is limited by lack of normative data. Larger studies are needed to generate Australian screening recommendations. Further assessment of the potential adverse effects of atypical antipsychotic medication on glucose homeostasis in this at‐risk group is important.
Child booster seats and lethal seat belt injury
Authors: Byard RW , Noblett H
Published: October 2004

Abstract: A 7‐year‐old boy travelling in the rear seat of a sedan car was wearing a lap‐shoulder seat belt and sitting on a booster seat. Following a collision the boy ‘submarined’ under the seat belt sustaining trauma to the anterior aspect of his neck, cardiac arrest and subsequent death from hypoxic‐ischaemic encephalopathy. This case demonstrates a potential problem with unsecured older‐style booster seats. Movement of a seat in a collision may cause a child to slip under a seat belt and sustain significant neck injuries. Seatbelts for children must be correctly fitted, booster seats or capsules must be securely fastened and manufacturer's recommendations for size and weight limits should be followed. Unfortunately older booster seats may not have attached instructions for installation and use, may not fit later model vehicles, may not conform to current safety recommendations and may have worn webbing. For these reasons their use should be discouraged.
Addison's disease presenting with an acute abdomen and complicated by cardiomyopathy
Authors: Wiltshire EJ , Wilson R , Pringle KC
Published: October 2004

Abstract:  Adrenal insufficiency typically presents with non‐specific symptoms, followed by shock secondary to a salt‐wasting crisis and/or the vascular effects of glucocorticoid deficiency if it progresses to acute adrenal insufficiency. Rhabdomyolysis and cardiac dysfunction are rarely reported, particularly in children. We report a child with adrenal insufficiency, presenting with acute abdominal signs, probably secondary to rhabdomyolysis, and complicated by reversible cardiomyopathy. Acute adrenal insufficiency should be considered with this presentation. The possibility of impaired cardiac function during its treatment should also be considered.
Use of the newborn screening card to define cause of death in a 12‐year‐old diagnosed with epilepsy
Authors: Skinner JR , Chong B , Fawkner M , Webster DR , Hegde M
Published: October 2004

Abstract:  Post‐mortem investigation of sudden death in young people frequently reveals no overt cause for the death. Full investigation is hampered if tissue or blood is not retained for DNA analysis. We report a post mortem molecular diagnosis of long QT syndrome in a 12‐year‐old boy diagnosed with epilepsy who died suddenly playing sport. The DNA was extracted from an archived blood spot on his newborn screening (‘Guthrie’) card, which had been taken from him at 6 days of age. A missense mutation was detected in exon 5 of the KCNQ1 gene; R243C (835C > T), associated with long QT type 1. The same mutation was found in the mother (who now takes effective preventative therapy), but not in the sib who has now been reassured that she is not at risk of sudden death.
Reform of Accounting Education in the Post‐Enron Era: Moving Accounting ‘Out of the Shadows’
Authors: Amernic Joel , Craig Russell
Published: October 2004

This article reflects critically on the general state of university‐based accounting education. It highlights the chiding of business school educators by the President of the U.S.A., George W. Bush, in his response to the collapse of Enron and subsequent corporate failures. It draws attention to Bush's plea for corporate accounting to be moved ‘out of the shadows’.

An agenda of reform for accounting education is proposed, seeking a greater responsiveness by accounting educators to three broad matters: first, the political, rhetorical and ideological nature of accounting; second, the ‘poverty of discourse’ in accounting curricula; and third, the merits of a better understanding of accounting history. It is suggested that responsiveness to these matters be manifest in a stronger commitment to critique of accounting. This entails implementation of four curriculum themes commencing in the first class in accounting. The benefits of reading and reflecting upon the collected life's work of distinguished intellectual forbears of our discipline are canvassed. Wide‐ranging general proposals for the reform of accounting education are advanced.
Accounting Reform in Australia: Contrasting Cases of Agenda Building
Authors: Jones Stewart , Rahman Sheikh F. , Wolnizer Peter W.
Published: October 2004

On 4 March 1997, the Department of Treasury of the Australian Government announced sweeping measures to reform standard setting arrangements in Australia (CLERP Paper No.1, Commonwealth of Australia, 1997). The Government's agenda is profoundly reformist as it recommended the wholesale adoption of International Accounting Standards by Australian reporting entities, as well as advocating the introduction of market (selling) price accounting both nationally and internationally. While the notion of market value accounting is not new, this recommendation appears to be a historical first from a government, regulatory or standard setting body. Against this background, our study draws on a framework of ‘political agenda building’ proposed by Cobb and Elder (1972) and Cobb et al. (1976), in order to compare and contrast the competing standard setting reform agendas adopted by the Australian accounting profession and the Government. Using the Cobb and Elder framework, we discuss potential reasons why the CLERP agenda has supplanted that of the Australian accounting profession as well as some implications of these developments for the future of standards harmonization.
Students’ attitudes to digital radiography and measurement accuracy of two digital systems in connection with root canal treatment
Authors: Wenzel A. , Kirkevang L.‐L.
Published: October 2004

The aim of this study was to evaluate students’ attitudes towards digital radiography and measurement accuracy in digital images recorded with a CCD‐sensor and a photostimulable phosphor (PSP) plate radiography system in connection with root canal treatment. Thirty‐one dental students participated in an endodontic course. Two single‐rooted teeth were assigned at random to two receptors for digital radiographic examination, either (i) the RVG‐ui CCD sensor or (ii) the Digora PSP plate system. After the endodontic treatment had been completed for the first tooth, the student filled in a questionnaire on their use of the digital system. Thereafter, the students switched radiography system and repeated the procedure for the second tooth. Eventually, the students completed the questionnaire by answering questions that directly compared the two digital systems. The gutta‐percha filled tooth was measured using the system's own software. Two measurements of each tooth were performed: total tooth length (TTL) and root filling length (RFL). The teeth were dismounted from the plaster blocks and the true TTL and RFL was measured with an electronic slide calliper. The majority of the students had used the contrast enhancement facility (CCD sensor = 52%, PSP = 71%) and the zoom facility (65—68%) whilst some had used the density enhancement facility (CCD sensor = 39%, PSP = 55%). The students stated that they saved more time when they used the CCD sensor than when they used the PSP system (P < 0.001), and that it was easier to position the tooth with the PSP plate than with the sensor (P < 0.01). The lengths measured on the digital images from both digital systems were marginally larger than the true tooth lengths (P < 0.05). However, there was no difference between the two digital systems for the TTL/RFL ratio (P > 0.05).