bluuebunny/crossref_metadata_2025 huggingface dataset:
Neue Halogenochalkogen(IV)‐Säuren: [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10]
Authors: Hammerschmidt A. , Bonmann S. , Läge M. , Krebs B.
Published: October 2004

Gezielte Versuche zur Synthese neuer Halogenochalkogen(IV)‐Säuren führten mit Tellur und Brom zu den neuen Verbindungen [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] (1) und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10] (2). Die [Te2Br10]2‐‐Anionen bestehen aus zwei kantenverknüpften verzerrten TeBr6‐Oktaedern, die Oxoniumkationen werden durch Kronenether stabilisiert. (1) kristallisiert in der monoklinen Raumgruppe P21/n mit a = 14, 520(5) Å, b = 22, 259(6) Å, c = 16, 053(5) Å, β = 97, 76(3)° und Z = 4, während für (2) die trikline Raumgruppe $P {\bar 1}$ mit a = 11, 005(4) Å, b = 12, 103(5) Å, c = 14, 951(6) Å, α = 71, 61(3)°, β = 69, 17(3)°, γ = 68, 40(3)° und Z = 1 gefunden wurde.
Synthesis and Structures of New Oxidation/ Cycloaddition Products of λ3‐Cyclodiphosphazanes
Authors: Kumar K. Praveen , Chakravarty Manab , Swamy K. C. Kumara
Published: October 2004

Reaction of the cyclodiphosphazane [(OC4H8N)P(μ‐N‐t‐Bu)2P(HN‐t‐Bu)] (1) with an equimolar quantity of diisopropyl azodicarboxylate afforded the phosphinimine product [(OC4H8N)P(μ‐N‐t‐Bu)2P=N‐t‐Bu)(N(CO2 ‐i‐Pr)NHCO2‐i‐Pr] (6) having a PIII‐N‐PV skeleton. Similar products [(t‐BuNH)P(μ‐N‐t‐Bu)2P=N‐t‐Bu)(N(CO2Et)NHCO2Et] (7) and [(CO2‐i‐Pr)HNN(CO2‐i‐Pr)](t‐BuN=P(μ‐N‐t‐Bu)2POCH2CMe2CH2O[P(μ‐N‐t‐Bu)2P=N‐t‐Bu)(N(CO2‐i‐Pr)NH(CO2‐i‐Pr)] (8) were spectroscopically characterized in the reaction of [(t‐BuNH)P‐N‐t‐Bu]2 (2) and [(t‐BuNH)P(μ‐N‐t‐Bu)2POCH2CMe2CH2OP(μ‐N‐t‐Bu)2P(NH‐t‐Bu)] (3) with diethyl‐ and diisopropyl azodicarboxylate, respectively. By contrast, the reaction of [(μ‐t‐BuN)P]2[O‐6‐t‐Bu‐4‐Me‐C6H2]2CH2 (4) and [(C5H10N)P‐μ‐N‐t‐Bu]2 (5) with diisopropyl azodicarboxylate afforded the mono‐ and bis‐oxidized compounds [(O)P(μ‐N‐t‐Bu)2P][O‐6‐t‐Bu‐4‐Me‐C6H2]2CH2 (9) and [(C5H10N)(O)P‐μ‐N‐t‐Bu]2 (10), respectively. Oxidative addition of o‐chloranil to 7 and its DIAD analogue [(t‐BuNH)P(μ‐N‐t‐Bu)2P=N‐t‐Bu)(N(CO2‐i‐Pr)NHCO2‐i‐Pr] (11) afforded [(C6Cl4‐1, 2‐O2)(t‐BuNH)P(μ‐N‐t‐Bu)2P=N‐t‐Bu)(N(CO2R)NHCO2R] [R = Et (12) and i‐Pr (13)] containing tetra‐ and pentacoordinate PV atoms in the cyclodiphosphazane ring. The structures of 6, 9, 12 and 13 have been confirmed by X‐ray structure determination. For comparison, the X‐ray structure of the double cycloaddition product [(C6Cl4‐1, 2‐O2)(t‐BuNH)PN‐t‐Bu]2 (14), obtained from the reaction of 2 with two mole equivalents of o‐chloranil is also reported.
Organic‐Inorganic Hybrids based on Polyoxometalates. Part 8 Synthesis and Spectroscopic Characterization of the Heterosilylated Anions [PW9O34(tBuSiO)3(SiR)]3‐ (R = ‐CH3, ‐CH=CH2, ‐CH2‐CH=CH2, ‐(CH2)4‐CH=CH2) ‐ X‐ray Crystal Structure of [nBu4N]3[PW9O34(tBuSiO)3(SiCH2‐CH=CH2)]
Authors: Agustin Dominique , Coelho Cristina , Mazeaud Agnès , Herson Patrick , Proust Anna , Thouvenot René
Published: October 2004

The reaction of the open‐structure anion [PW9O34(tBuSiOH)3]3‐ with RSiCl3 (R = (CH2)nCH=CH2 (n = 0, 1, 4)) affords [PW9O34(tBuSiO)3(SiR)]3‐ heterosilylated capped hybrid compounds. These complexes were characterized by infrared spectroscopy and in solution by multinuclear (1H, 29Si, 31P and 183W) NMR. Crystals of [nBu4N]3[PW9O34(tBuSiO)3Si(CH2‐CH=CH2)] are orthorhombic, space group P212121 (No 19), with lattice constants a = 15.599(2) Å, b = 23.963(5) Å, c = 26.886(1) Å, V = 10.050(3) Å3, and Z = 4.
Syntheses and Molecular Structures of Titanium Derivatives with Polymerizable Ligands. Toward Extended Arrays
Authors: Cauro‐Gamet Lauren C. , Hubert‐Pfalzgraf Liliane G. , Lecocq Sylvain
Published: October 2004

The reactions between Ti(OR)4 and allylacetatoacetate (HAAA) in 1:1 or 1:2 stoichiometry at rt gave Ti2(OR)6(AAA)2 R = Et (1), iPr (2) and Ti(OR)2(AAA)2 R = Et (3), iPr (4) species. A monosubstituted derivative Ti2(OiPr)6(AMP)2 (5) was isolated with allylmethylphenol (AMPH). 1 and 5 were characterized by single crystal X‐ray diffraction. Their molecular structures consist of dimers with the polymerizable ligands in terminal positions andbridging alkoxide ligands assembling five and six‐coordinated metal atoms, respectively. The Ti‐O bond lengths of 1 are in the range 1.76(1) to 2.11(1) Å with the variation Ti‐OEt < Ti‐μ‐OEt < Ti‐η2‐O (allylacetatoacetate). All compounds were characterized by FT‐IR and 1H NMR. The possibility to accede to more extended arrays either by hydrolysis or by radical initiated homo‐ or co‐polymerization reactions was investigated for the allylacetato derivatives as well as for Ti(OiPr)2(AAEMA)2 AAEMA = [2‐(methacryloyloxy)ethylacetoacetato] for the latter reactions.
Chalcogenide Derivatives of the seco‐Cubane [Sn3(μ2‐NHtBu)2(μ2‐NtBu)(μ3‐NtBu)]
Authors: Chivers Tristram , Eisler Dana J. , Ritch Jamie S.
Published: October 2004

A series of monochalcogenide derivatives of the seco‐cubane [Sn3(μ2‐NHtBu)2(μ2‐NtBu)(μ3‐NtBu)] has been prepared and characterized by NMR and X‐ray crystallographic studies. These complexes exhibit different tin‐chalcogen bonding modes. In the case of the monotelluride, a terminal Sn=Te bond was observed in solution and in the solid state, whereas for the monosulfide, a μ2 bridging mode was adopted by the sulfur atoms. The monoselenide was found to employ both bonding modes in solution, although only the terminal Sn=Se bonding mode was structurally characterized. The complexes undergo chalcogen exchange between tin atoms in solution, and this process was studied by variable temperature NMR.
O, N‐Chelated Vanadium(IV) Oxo Aminophenolate Complexes: the Effect of Steric Bulk on the Vanadium Coordination Geometry. Can this Influence be detected Spectroscopically?
Authors: Hagen Henk , Reinoso Santiago , Reijerse Ed J. , van Faassen Ernst E. , Lutz Martin , Spek Anthony L. , van Koten Gerard
Published: October 2004

In order to study the effect of steric bulk on the vanadium coordination geometry in O, N‐chelated vanadium oxo (bis)phenolates, six different ortho‐aminophenolate ligands have been used. The ortho‐aminophenolate system was changed at three different places, i.e. 1) the second ortho position (C6) of the arene ring (R), 2) the substituents at the amino nitrogen (R′ and R″), and 3) the benzylic carbon atom (R*). The phenols were used in the preparation of the vanadium oxo (bis)phenolate complexes. In order to study whether it is possible to predict geometrical features of these vanadium complexes, UV/Vis, solution and frozen state EPR and 14N ESEEM spectroscopic data was measured and compared to the structural features of four structurally characterized vanadium oxo (bis)phenolates. Unfortunately, it turned out that is was not possible to correlate the EPR parameters, the UV/Vis HOMO‐LUMO transitions or 14N hyperfine couplings to the structural parameters.
Oscillation modes of microtubules
Authors: Kasas S. , Cibert C. , Kis A. , De Rios P. Los , Riederer B.M. , Forró L. , Dietler G. , Catsicas S.
Published: October 2004

Abstract Microtubules are long, filamentous protein complexes which play a central role in several cellular physiological processes, such as cell division transport and locomotion. Their mechanical properties are extremely important since they determine the biological function. In a recently published experiment [Phys. Rev. Lett. 89 (2002) 248101], microtubule's Young's and shear moduli were simultaneously measured, proving that they are highly anisotropic. Together with the known structure, this finding opens the way to better understand and predict their mechanical behavior under a particular set of conditions. In the present study, we modeled microtubules by using the finite elements method and analyzed their oscillation modes. The analysis revealed that oscillation modes involving a change in the diameter of the microtubules strongly depend on the shear modulus. In these modes, the correlation times of the movements are just slightly shorter than diffusion times of free molecules surrounding the microtubule. It could be therefore speculated that the matching of the two timescales could play a role in facilitating the interactions between microtubules and MT associated proteins, and between microtubules and tubulins themselves.
A novel site of AKT‐mediated phosphorylation in the human MDM2 onco‐protein
Authors: Milne Diane , Kampanis Petros , Nicol Samantha , Dias Sylvia , Campbell David G. , Fuller-Pace Frances , Meek David
Published: October 2004

MDM2 is an E3 ubiquitin ligase which mediates ubiquitylation and proteasome‐dependent degradation of the p53 tumor suppressor protein. Phosphorylation of MDM2 by the protein kinase AKT is thought to regulate MDM2 function in response to survival signals, but there has been uncertainty concerning the identity of the sites phosphorylated by AKT. In the present study, we identify Ser‐166, a site previously reported as an AKT target, and Ser‐188, a novel site which is the major site of phosphorylation of MDM2 by AKT in vitro. Analysis of MDM2 in cultured cells confirms that Ser‐166 and Ser‐188 are phosphorylated by AKT in a physiological context.
The importance of Loop 7 for the activity of calcineurin
Authors: Liu Ping , Huang Chao , Wang Hai-long , Zhou Ke , Xiao Fang-xiang , Qun Wei
Published: October 2004

Calcineurin (CN) is a heterodimer composed of a catalytic subunit (CNA) and a regulatory subunit (CNB). Loop 7 lies within the CNA catalytic domain. To investigate the role of Loop 7 in enzyme activity, we systematically examined all its residues by site‐directed deletion mutation. Our results show that the Loop 7 residues are important for enzyme activity. Besides deleting residues V314, Y315 or N316, enzyme activity also increased dramatically when residues D313 or K318 were deleted. In contrast, almost all activity was lost when L312 or N317 were deleted. Ni2+ and Mn2+ were effective activators for all active mutants. However, whereas the wild‐type enzyme was more efficiently activated by Ni2+ than by Mn2+ with 32P‐labeled RII peptide as substrate, the reverse was true in all the mutants. We also found that the effect of Loop 7 on enzyme activity was substrate dependent, and involved interactions between Loop 7 residues and the unresolved part of the CN crystal structure near the auto‐inhibitory domain and catalytic site.
A brilliant monomeric red fluorescent protein to visualize cytoskeleton dynamics in Dictyostelium
Authors: Fischer Markus , Haase Ilka , Simmeth Evelyn , Gerisch Günther , Müller-Taubenberger Annette
Published: October 2004

Red fluorescent proteins (RFPs) combined with GFP are attractive probes for double‐fluorescence labeling of proteins in live cells. However, the application of these proteins is restrained by stable oligomer formation and by their weak fluorescence in vivo. Previous attempts to eliminate these problems by mutagenesis of RFP from Discosoma (DsRed) resulted in the monomeric mRFP1 and in the tetrameric RedStar RFP, which is distinguished by its enhanced fluorescence in vivo. Based on these mutations, we have generated an enhanced monomeric RFP, mRFPmars, and report its spectral properties. Together with green fluorescent labels, we used mRFPmars to visualize filamentous actin structures and microtubules in Dictyostelium cells. This enhanced RFP proved to be suitable to monitor the dynamics of cytoskeletal proteins in cell motility, mitosis, and endocytosis using dual‐wavelength fluorescence microscopy.
Biochemical characterization of the major adenylyl cyclase, Cya1, in the cyanobacterium Synechocystis sp. PCC 6803
Authors: Masuda Shinji , Ono Taka-aki
Published: October 2004

We report herein the biochemical properties of an adenylyl cyclase, Cya1, from the cyanobacterium Synechocystis sp. PCC 6803. Heterologously expressed Cya1 catalyzed cyclic AMP formation with a K
m for ATP of approximately 2.2 μM at pH 7.5. Although cellular Cya1 activity is increased by blue light illumination [Terauchi and Ohmori, Mol. Microbiol. 52 (2004) 303], purified Cya1 did not contain any chromophores, and the activity was light‐insensitive. This suggests that an unknown blue light‐responsive factor interacts with the N‐terminal regulatory domain of Cya1 to control its adenylyl cyclase activity. Finally, our results show that the sensor of blue light using FAD (BLUF) protein, Slr1694, does not appear to be involved in the regulation of Cya1‐mediated cAMP signal transduction in this bacterium.
Purification and primary structure of two isoforms of arenicin, a novel antimicrobial peptide from marine polychaeta Arenicola marina
Authors: Ovchinnikova Tatiana V. , Aleshina Galina M. , Balandin Sergey V. , Krasnosdembskaya Anna D. , Markelov Mikhail L. , Frolova Elena I. , Leonova Yulia F. , Tagaev Andrey A. , Krasnodembsky Eugeny G. , Kokryakov Vladimir N.
Published: October 2004

Two novel 21‐residue antimicrobial peptides, arenicin‐1 and arenicin‐2, exhibiting activity against Gram‐positive and Gram‐negative bacteria and fungi, were purified from coelomocytes of marine polychaeta Arenicola marina (lugworm) by preparative gel electrophoresis and RP‐HPLC. Molecular masses (2758.3 and 2772.3 Da) and complete amino acid sequences (RWCVYAYVRVRGVLVRYRRCW and RWCVYAYVRIRGVLVRYRRCW)

1
were determined for each isoform. Each arenicin has one disulfide bond (Cys3‐Cys20). The total RNA was isolated from the lugworm coelomocytes, RT‐PCR and cloning were performed, and cDNA was sequenced. A 202‐residue preproarenicin contains a putative signal peptide (25 amino acids) and a long prodomain. Arenicins have no structure similarity to any previously identified antimicrobial peptides.
Ethanol acts as a potent agent sensitizing colon cancer cells to the TRAIL‐induced apoptosis
Authors: Vaculová Alena , Hofmanová Jiřina , Souček Karel , Anděra Ladislav , Kozubı́k Alois
Published: October 2004

Identification of mechanisms of modulation of the TNF‐related apoptosis‐inducing ligand (TRAIL)‐induced apoptosis is important for its potential use in anticancer therapy. Ethanol can induce cell death in vitro and in vivo by different signalling pathways. Its effect in combination with death ligands is unknown. We investigated how ethanol modulates the effects of TRAIL in colon cancer cells. After combined TRAIL and ethanol treatment, a potentiation of caspase‐8, ‐9, ‐3 activation, a proapoptotic Bid protein cleavage, a decrease of mitochondrial membrane potential, a complete poly(ADP)ribose polymerase cleavage, and disappearance of antiapoptotic Mcl‐1 protein were demonstrated. Ethanol acts as a potent agent sensitizing colon cancer cells to TRAIL‐induced apoptosis.
A multicystatin is induced by drought‐stress in cowpea (Vigna unguiculata (L.) Walp.) leaves
Authors: Diop Ndeye Ndack , Kidrič Marjetka , Repellin Anne , Gareil Monique , d'Arcy-Lameta Agnés , Pham Thi Anh Thu , Zuily-Fodil Yasmine
Published: October 2004

Cystatins are protein inhibitors of cystein proteinases belonging to the papain family. In cowpea, cystatin‐like polypeptides and a cDNA have been identified from seeds and metabolic functions have been attributed to them. This paper describes VuC1, a new cystatin cDNA isolated from cowpea leaves (Vigna unguiculata (L.) Walp.). Sequence analysis revealed a multicystatin structure with two cystatin‐like domains. The recombinant VUC1 protein (rVUC1) was expressed in an heterologous expression system and purified to apparent homogeneity. It appeared to be an efficient inhibitor of papain activity on a chromogenic substrate. Polyclonal antibodies against rVUC1 were obtained. Involvement of the VuC1 cDNA in the cellular response to various abiotic stresses (progressive drought‐stress, dessication and application of exogenous abscissic acid) was studied, using Northern blot and Western blot analysis, in the leaf tissues of cowpea plants corresponding to two cultivars with different capacity to tolerate drought‐stress. Surprisingly, these abiotic stresses induced accumulation of two VuC1‐like messages both translated into VUC1‐like polypeptides. Difference in the transcript accumulation patterns was observed between the two cultivars and related to their respective tolerance level. Presence of multiple cystatin‐like polypeptides and their possible involvement in the control of leaf protein degradation by cysteine proteinases is discussed.
Contribution of the active site aspartic acid to catalysis in the bacterial neuraminidase from Micromonospora viridifaciens
Authors: Watson Jacqueline N. , Newstead Simon , Dookhun Veedeeta , Taylor Garry , Bennet Andrew J.
Published: October 2004

A recombinant D92G mutant sialidase from Micromonospora viridifaciens has been cloned, expressed and purified. Kinetic studies reveal that the replacement of the conserved aspartic acid with glycine results in a catalytically competent retaining sialidase that possesses significant activity against activated substrates. The contribution of this aspartate residue to the free energy of hydrolysis for natural substrates is greater than 19 kJ/mol. The three dimensional structure of the D92G mutant shows that the removal of aspartic acid 92 causes no significant re‐arrangement of the active site, and that an ordered water molecule substitutes for the carboxylate group of D92.
The poison Dart frog's batrachotoxin modulates Nav1.8
Authors: Bosmans Frank , Maertens Chantal , Verdonck Fons , Tytgat Jan
Published: October 2004

Batrachotoxin is a potent modulator of voltage‐gated sodium channels, leading to irreversible depolarisation of nerves and muscles, fibrillation, arrhythmias and eventually cardiac failure. Since its discovery, field researchers also reported numbness after their skin came into contact with this toxin. Intrigued by this phenomenon, we determined the effect of batrachotoxin on the voltage‐gated sodium channel Nav1.8, which is considered to be a key player in nociception. As a result, we discovered that batrachotoxin profoundly modulates this channel: the inactivation process is severely altered, the voltage‐dependence of activation is shifted towards more hyperpolarised potentials resulting in the opening of Nav1.8 at more negative membrane potentials and the ion selectivity is modified.
Mitigation of seal-induced damage in salmon and whitefish trapnet fisheries by modification of the fish bag
Authors: Lehtonen Esa , Suuronen Petri
Published: October 2004

During the past decade, seal-induced gear and catch damage has increased dramatically in the Baltic Sea. The problems are most severe in the coastal trapnet fisheries for salmon (Salmo salar) and whitefish (Coregonus lavaretus), where grey seals (Halichoerus grypus) in particular frequently visit the traps. There is an acute need for gear modifications and other solutions that can prevent seals from entering the fish bag of the traps. Modifications that have been tested in Finland include a wire grid installed in the funnel of the trap and a fish bag made of extra-strong netting material. In comparative fishing experiments conducted in 2001 in the Gulf of Finland the grid was made of 2-mm steel wires with 175-mm spacing. The average undamaged salmon catch per haul in the fish bag of modified trapnets was significantly higher (70%) than that of traditional traps (Mann–Whitney, p < 0.01). In the whitefish experiments, the average undamaged catch of whitefish per haul was 16% higher in modified trapnets than in traditional traps, but the difference was not significant (Mann–Whitney, p > 0.05). These results indicate that the wire grid did not prevent fish from swimming into the fish bag. Experiments also suggest that the wire grid and the extra-strong netting prevented seals from entering the bag. However, on some occasions seals were able to tear the fish through the netting. Underwater observations confirmed that the wire grid kept adult seals outside the bag while salmon and whitefish could be seen entering through the grid into the bag.
Reaction of juvenile flounder to grid separators
Authors: Matsushita Yoshiki , Fujita Kaoru , Ikegami Naoya , Ohata Satoshi
Published: October 2004

The reaction behaviour of juvenile Japanese flounder (Paralichthys olivaceus) to towed grids (0.5 × 0.2 m, horizontally, or vertically orientated bars at 10-mm intervals) was observed as a means of understanding fish behaviour in relation to grid selection for a beam trawl fishery in Tokyo Bay. Reaction behaviours were categorized within four patterns by grid types and illumination levels: (i) forward swimming in towed direction; (ii) swimming over the grid; (iii) sticking on the grid; and (iv) passing through the grid. The most dominant reaction pattern was forward swimming, but its ratio was higher for light than for dark conditions. Passing through the grid bars occurred most frequently with horizontal bars. Approximately 40% of tested fish passed through the grid in light conditions, approximately 30% in dark conditions. Most of these fish penetrated bar gaps head first, while a considerable proportion categorized as “forward swimming” kept swimming even though their tails or bodies had partly passed between the bars. It is concluded that penetration of flounders through bar gaps is governed by voluntary actions.
Direct measurement of the swimming speed, tailbeat, and body angle of Japanese flounder (Paralichthys olivaceus)
Authors: Kawabe Ryo , Naito Yasuhiko , Sato Katsufumi , Miyashita Kazushi , Yamashita Nariharu
Published: October 2004

It is well known that flatfish species such as plaice can utilize the selective tidal stream to conduct vertical movements. However, detailed description of actual swimming behaviour is lacking, principally as a result of the difficulties encountered in monitoring the behaviour of flatfish in the open sea. The present study describes the use of a newly developed data-logger in obtaining simultaneous recordings of the swimming speed, depth, tailbeat, and body angle of free-ranging Japanese flounder (Paralichthys olivaceus) in the open sea. Our data indicate that Japanese flounders adopt a tailbeat-and-glide behaviour. They are found to glide downward without tailbeats for propulsion, and only during the ascent phase are tailbeats conducted. Flounders move horizontally at speeds of 0.59–1.23 km d−1 and at a maximum speed of 0.70–0.82 km h−1 in the open sea. Modal flounder swimming speeds are 30–40 cm s−1 (0.57–0.76 and 0.58–0.77 BL s−1), i.e. sometimes lower than the threshold of the speed sensor. In most cases, however, tailbeat oscillations occur at frequencies of 1.2–1.4 Hz. Moreover, flounders travel at a significantly steeper angle during the ascent phase than during the descent phase. In both cases it is believed that flounder optimize the energetic costs of migration, as has been shown for tuna, sharks, and seals.
Interactions between fish and fisher's spatial distribution and behaviour: an empirical study of the anchovy (Engraulis ringens) fishery of Peru
Authors: Bertrand Sophie , Díaz Erich , Ñiquen Miguel
Published: October 2004

Fishing data provide, with wide spatio-temporal coverage, inexpensive information about exploited species, but a precondition for their interpretation is a good comprehension of fish and fisher spatial dynamics and interactions. In Peru, anchovy (Engraulis ringens) is exploited by an industrial fleet of about 800 purse-seiners operating all along the coast. Using simultaneous acoustic survey and commercial fishing data for the 1998–2001 time period, we present a preliminary, exploratory, and empirical approach to identify the nature of potential interactions between Peruvian anchovy and fisher behaviour. We show that (i) Peruvian anchovy exhibited a composite spatial strategy for the study period, i.e. a change in biomass was associated with both change in geographical extension and density; (ii) fishing behaviour significantly varied within and among vessels in terms of travel duration, searching duration, and number of fishing sets; and (iii) interactions between fish and fisher behaviours differed according to the spatial scale. At a fish stock scale (the scale of fishing ground selection for fishers), fishing was more efficient with low biomass and high spatial concentration (low stock range and high biomass); at a local fish spatial scale (the scale of searching for a school inside the fishing ground), fishing performance was favoured by high mean local abundances and low spatial concentration (the way fish is distributed inside its stock range); finally, at the school scale (the scale of the fishing set), both high abundance and high spatial concentration were favourable to fishing success.
Developmental profile of NTPDase activity in synaptic plasma membranes isolated from rat cerebral cortex
Authors: Nedeljkovic N. , Banjac A. , Horvat A. , Stojiljkovic M. , Nikezic G.
Published: October 2004

In the present study the developmental profile of ATP‐hydrolyzing activity promoted by NTPDase 1, its kinetic properties and the enzyme protein abundance associated with synaptic plasma membrane from rat cerebral cortex were characterized. NTPDase 1 activity increased from birth to day 30; afterwards it decreased and remained unchanged from adulthood (90 days) to senescence (365 days). Kinetic analysis revealed that enzyme exhibited the highest specific activity at day 30 and highest apparent affinity for ATP at day 365; however,Vmax/Kmvalues remained unchanged for each age studied. Immunoblot analysis demonstrated that relative abundance of NTPDase 1 is highest at day 15 during ontogeny. The discrepancy between maximum enzyme activity and maximum enzyme protein abundance indicates that NTPDase 1 may have an additional role during development.
Hypothyroidism changes adenine nucleotide hydrolysis in synaptosomes from hippocampus and cerebral cortex of rats in different phases of development
Authors: Bruno Alessandra Nejar , Ricachenevsky Felipe Klein , Pochmann Daniela , Bonan Carla Denise , Battastini Ana Maria Oliveira , Barreto‐Chaves Maria Luiza M. , Sarkis João José Freitas
Published: October 2004

The influence of the thyroid hormones on the normal function of the mammalian central nervous system depends on the brain region and on the developmental stage. Adenine nucleotides and their products also affect the brain function; ATP is an excitatory neurotransmitter, and adenosine has inhibitory effects on neurotransmission. Thus, this study aimed to evaluate the effects of hypothyroidism on the hydrolysis of ATP to adenosine in hippocampal and cortical synaptosomes and blood serum of rats during different phases of development. Rats aged 60 and 420 days old were divided into three groups: control, sham‐operated and hypothyroid. Hypothyroidism was induced in these rats by thyroidectomy and methimazole (0.05%) added to their drinking water for 14 days. Neonatal hypothyroidism was induced by adding 0.02% methimazole in the drinking water from day 9 of gestation, and continually until 14 days old. Hypothyroidism increased the AMP hydrolysis in both hippocampus and cerebral cortex synaptosomes of rats in all aged tested. In blood serum, thyroid hormones deficiency increased the AMP hydrolysis in 14‐day‐old rats and the hydrolysis of ATP, ADP and AMP in 60‐day‐old rats; however, no alteration was observed in 420‐day‐old rats. Thus, our results suggest the involvement of the 5′‐nucleotidase in synaptic function control in hypothyroidism throughout brain development.
Recombinant factor VIIa after amniotic fluid embolism and disseminated intravascular coagulopathy
Authors: Lim Y. , Loo C.C. , Chia V. , Fun W.
Published: October 2004

This case report illustrates the successful use of activated recombinant factor VIIa in the management of severe postpartum hemorrhage secondary to amniotic fluid embolism.
Metformin therapy in women with polycystic ovary syndrome
Authors: Aruna J. , Mittal S. , Kumar S. , Misra R. , Dadhwal V. , Vimala N.
Published: October 2004

Objective

To determine the clinical, biochemical, hormonal, and ultrasonographic effects of 6 months of metformin therapy in women with polycystic ovary syndrome (PCOS) and compare with pretherapy parameters.

Method

50 Indian women with PCOS, 25 unmarried and 25 married, infertile women, were enrolled in this prospective clinical study. After a baseline workup, including body mass index (BMI), waist hip ratio (WHR), Ferriman Gallwey hirsutism scoring, menstrual pattern, levels of fasting insulin, lipids, oral glucose tolerance test (OGTT), serum gonadotropins, estradiol (E2), testosterone, androstenedione, sex hormone binding globulin (SHBG), and dehydroepiandrosterone sulphate (DHEAS), patients were given 1000 gm of metformin for 6 months and then reevaluated.

Result

In 41 of 50 women who completed treatment, significant improvement in BMI, WHR, menstrual cyclicity (80.5%), ovulation rate (66%), and pregnancy rate (28%) was noted. Statistically significant decrease in lutenising hormone (LH) and LH/FSH ratio with an increase in follicle stimulating hormone (FSH) levels were seen. Levels of high‐density lipoprotein (HDL) cholesterol (Chol) increased along with a decrease in total cholesterol. Improvement was noted in ovarian volume, stromal thickness, and number of follicles. There was no change in hirsutism, acne, levels of other sex steroid hormones, and lipids.

Conclusion

A 6‐month course of metformin therapy may improve menstrual cyclicity and fertility in women with PCOS.
Linking publicness to operations management practices: a study of quality management practices in hospitals
Authors: Goldstein Susan Meyer , Naor Michael
Published: October 2004

The goal of this study is to serve as a foundation to establish a link between the theory of organizational publicness and operations management practices. Quality management practices provide the unit of analysis for studying this linkage. The theory of organizational publicness is used to establish that organizations can be defined on a continuum of publicness rather than as purely public or purely private. Particular cultural factors, political influences, and organizational characteristics define this publicness. The study investigates the linkage between four publicness dimensions (ownership, goal setting, funding, and control) and operations‐related quality practices (information and analysis, staff focus, and process management) in U.S. hospitals. The results of regression analysis show that the publicness dimensions of ownership and control are related to some quality management practices, with control (i.e. public responsibility and compliance) having a significant effect throughout the studied models. Hospital goal setting and funding, two additional publicness dimensions, are not significantly related to quality management practices. The results of this study build our understanding of how operations practices are used in public organizations and help to define the extent to which publicness matters.
A theory of formal conceptual definitions: developing theory‐building measurement instruments
Authors: Wacker John G.
Published: October 2004

This study develops the need for formal conceptual definitions (sometimes called nominal definitions) and how to develop better measurement instruments for theory‐building. It develops the underlying theory for ‘good’ formal conceptual definitions by defining terms, demonstrating that formal conceptual definitions are needed for all theory‐building empirical research, explains how and why ‘good’ formal conceptual definitions are used to develop properties and their measures, and last, it logically explains that good formal conceptual definitions are necessary conditions for construct validity (content validity, criterion validity, convergent validity, and discriminant validity) while statistical tests are sufficient conditions for validity. This theory development explains why formal conceptual definitions are necessary before any traditional statistical empirical validity tests are performed. This study suggests that any statistical validity tests are not meaningful if the concept is not formally defined.

In short, the theory of formal conceptual definitions provides a structure to develop ‘good’ measures of the formal theory that leads to ‘good’ empirical theory‐building.
Holocene climate variability
Authors: Mayewski Paul A. , Rohling Eelco E. , Curt Stager J. , Karlén Wibjörn , Maasch Kirk A. , Meeker L. David , Meyerson Eric A. , Gasse Francoise , van Kreveld Shirley , Holmgren Karin , Lee-Thorp Julia , Rosqvist Gunhild , Rack Frank , Staubwasser Michael , Schneider Ralph R. , Steig Eric J.
Published: October 2004

Although the dramatic climate disruptions of the last glacial period have received considerable attention, relatively little has been directed toward climate variability in the Holocene (11,500 cal yr B.P. to the present). Examination of ?50 globally distributed paleoclimate records reveals as many as six periods of significant rapid climate change during the time periods 9000"8000, 6000"5000, 4200"3800, 3500"2500, 1200"1000, and 600"150 cal yr B.P. Most of the climate change events in these globally distributed records are characterized by polar cooling, tropical aridity, and major atmospheric circulation changes, although in the most recent interval (600"150 cal yr B.P.), polar cooling was accompanied by increased moisture in some parts of the tropics. Several intervals coincide with major disruptions of civilization, illustrating the human significance of Holocene climate variability.
Dimensions of depression, mania and psychosis in the general population
Authors: KRABBENDAM L. , MYIN-GERMEYS I. , DE GRAAF R. , VOLLEBERGH W. , NOLEN W. A. , IEDEMA J. , VAN OS J.
Published: October 2004

Background. In order to investigate whether correlated but separable symptom dimensions that have been identified in clinical samples also have a distribution in the general population, the underlying structure of symptoms of depression, mania and psychosis was studied in a general population sample of 7072 individuals.

Method. Data were obtained from the three measurements of the Netherlands Mental Health Survey and Incidence Study (NEMESIS). Symptoms of depression, mania and the positive symptoms of psychosis were assessed using the Composite International Diagnostic Interview. Confirmatory factor-analysis was used to test statistically the fit of hypothesized models of one, two, three or seven dimensions.

Results. The seven-dimensional model comprising core depression, sleep problems, suicidal thoughts, mania, paranoid delusions, first-rank delusions and hallucinations fitted the data best, whereas the unidimensional model obtained the poorest fit. This pattern of results could be replicated at both follow-up measurements. The results were similar for the subsamples with and without a lifetime DSM-III-R diagnosis. The seven dimensions were moderately to strongly correlated, with correlations ranging from 0·18 to 0·73 (mean 0·45).

Conclusions. In the general population, seven correlated but separable dimensions of experiences exist that resemble dimensions of psychopathology seen in clinical samples with severe mental illness. The substantial correlations between these dimensions in clinical and non-clinical samples may suggest that there is aetiological overlap between the different dimensions regardless of level of severity and diagnosable disorder.
What might not have been: an investigation of the nature of counterfactual thinking in survivors of trauma
Authors: DALGLEISH T.
Published: October 2004

Background. Counterfactual thinking (CFT) refers to the process of reflecting on an event and changing aspects of it so as to alter the eventual outcome. Such thinking appears frequent in survivors of trauma (e.g. ‘If only I had stayed at home then I wouldn't have had the accident’), but has received little systematic empirical investigation. Four studies examined the nature of CFT in both trauma survivors and non-traumatized controls.

Method. Participants generated CFT to their own trauma or to written scenarios.

Results. Three key findings emerged. Firstly, trauma survivors overwhelmingly produced CFT that mutated aspects of their own behaviour during the traumatic event (self-referent CFT) and that improved the event's outcome (upward CFT; Studies 1 and 2). Secondly, self-referent CFT style in trauma survivors was generalized to non-autobiographical scenarios and was independent of how much control the protagonist in the scenarios had over the outcome. In contrast, never-traumatized controls tended to generate more self-referent CFT to scenarios where the protagonists had some control than to scenarios where the protagonist had little control (Study 3). Thirdly, this self-referent, upward CFT style of trauma survivors was not related to frequency of post-traumatic stress symptoms (Studies 1 and 3) or Posttraumatic Stress Disorder (PTSD) caseness (Study 2).

Conclusions. These results are interpreted in terms of a self-referent, upward CFT style that is normative following trauma for all survivors, regardless of levels of trauma-related distress, and that is applied to any negative events that are encountered.
Capacity of adults with intellectual disabilities to consent to sexual relationships
Authors: MURPHY GLYNIS H. , O'CALLAGHAN ALI
Published: October 2004

Background. For people with intellectual disabilities there is a difficult balance to be struck between empowering people to claim their sexual rights and protecting them from abuse. Hypothetically, services should be guided by whether a particular person with intellectual disabilities has the capacity to consent to sexual relationships. However, there has been little agreement on how to define such capacity. This study examines the issue of capacity to consent to sexual relationships using a functional approach.

Method. Adults with intellectual disabilities (n=60) and young people presumed in law able to consent (n=60) were assessed for their sexual knowledge and vulnerability to abuse.

Results. Adults with intellectual disabilities were significantly less knowledgeable about almost all aspects of sex and appeared significantly more vulnerable to abuse, having difficulty at times distinguishing abusive from consenting relationships. Nevertheless, some adults with intellectual disabilities scored highly on all measures, especially if they had relatively high IQs and had had sex education.

Conclusions. The reasons for the poorer knowledge and increased vulnerability of people with intellectual disabilities are discussed and it is recommended that they should have on-going access to sex education. Implications of the findings for definitions of capacity to consent to sexual relationships are considered.
Production of pro-inflammatory cytokines correlates with the symptoms of acute sickness behaviour in humans
Authors: VOLLMER-CONNA U. , FAZOU C. , CAMERON B. , LI H. , BRENNAN C. , LUCK L. , DAVENPORT T. , WAKEFIELD D. , HICKIE I. , LLOYD A.
Published: October 2004

Background. Elaboration of the concept of cytokine-induced sickness behaviour in recent years has opened new avenues for understanding brain involvement in sickness and recovery processes. Additionally, this has led to much speculation about the role of the immune system in neuropsychiatric syndromes, including depression and chronic fatigue. However, few studies have examined this phenomenon as it naturally occurs in sick humans, and none has attempted to document the quantitative relationships between cytokine levels and non-specific symptoms. The aim of this research was to examine human sickness behaviour and its immunological correlates in documented Epstein–Barr virus (EBV), Q fever or Ross River virus (RRV) infections.

Method. We studied two separate samples. The first consisted of 21 patients with acute Q fever. The second included 48 patients with acute RRV or EBV infection. Psychological and somatic symptom profiles were derived from self-report measures completed at enrolment. Quantification of pro-inflammatory cytokines [interleukin (IL)-1β and IL-6] in sera and supernatants of peripheral blood mononuclear cell (PBMC) cultures was undertaken by specific ELISAs.

Results. Levels of IL-1β and IL-6 spontaneously released from PBMC cultures were consistently correlated with reported manifestations of acute sickness behaviour including fever, malaise, pain, fatigue, mood and poor concentration.

Conclusions. IL-1β and IL-6 produced as part of the host response represent sensitive markers of sickness behaviour in humans with acute infection. Further work is needed to systematically characterize the spectrum and natural history of sickness behaviour in humans and to elucidate its biological basis.
The impact of beliefs about mental health problems and coping on outcome in schizophrenia
Authors: LOBBAN F. , BARROWCLOUGH C. , JONES S.
Published: October 2004

Background. Using the theoretical framework of the Self Regulation Model (SRM), many studies have demonstrated that beliefs individuals hold about their physical health problems are important in predicting health outcomes. This study tested the SRM in the context of a mental health problem, schizophrenia.

Method. One hundred and twenty-four people with a diagnosis of schizophrenia were assessed on measures of symptom severity, beliefs about their mental health problems, coping and appraisal of outcome at two time points, 6 months apart.

Results. Using multivariate analyses and controlling for severity of symptoms, beliefs about mental health were found to be significant predictors of outcome. Beliefs about greater negative consequences were the strongest and most consistent predictors of a poorer outcome in both cross-sectional and longitudinal analyses.

Conclusions. These results suggest that the SRM is a promising model for mental health problems and may highlight important areas for development in clinical, and especially psychosocial interventions.
Severe acute respiratory syndrome (SARS) in Hong Kong in 2003: stress and psychological impact among frontline healthcare workers
Authors: TAM CINDY W. C. , PANG EDWIN P. F. , LAM LINDA C. W. , CHIU HELEN F. K.
Published: October 2004

Background. The outbreak of severe acute respiratory syndrome (SARS) posed an unprecedented threat and a great challenge to health professionals in Hong Kong. The study reported here aimed at investigating the origin of stress and psychological morbidity among frontline healthcare workers in response to this catastrophe.

Method. Self-administered questionnaires were sent to frontline healthcare workers in three hospitals. The General Health Questionnaire was used to identify psychological distress. Sociodemographic and stress variables were entered into a logistic regression analysis to find out the variables associated with psychological morbidity.

Results. The response rate was 40%. Sixty-eight per cent of participants reported a high level of stress. About 57% were found to have experienced psychological distress. The healthcare workers' psychological morbidity was best understood by the perceptions of personal vulnerability, stress and support in the workplace.

Conclusion. These findings shed light on the need for hospital administrators to be aware of the extent and sources of stress and psychological distress among frontline healthcare workers during disease outbreak.
Neuropsychological consequences of regular marijuana use: a twin study
Authors: LYONS M. J. , BAR J. L. , PANIZZON M. S. , TOOMEY R. , EISEN S. , XIAN H. , TSUANG M. T.
Published: October 2004

Background. Results of previous research examining long-term residual effects of marijuana use on cognition are conflicting. A major methodological limitation of prior studies is the inability to determine whether differences between users and non-users are due to differences in genetic vulnerability preceding drug use or due to the effects of the drug.

Method. Fifty-four monozygotic male twin pairs, discordant for regular marijuana use in which neither twin used any other illicit drug regularly, were recruited from the Vietnam Era Twin Registry. A minimum of 1 year had passed since the marijuana-using twins had last used the drug, and a mean of almost 20 years had passed since the last time marijuana had been used regularly. Twins were administered a comprehensive neuropsychological test battery to assess general intelligence, executive functioning, attention, memory and motor skills. Differences in performance between marijuana-using twins and their non-using co-twins were compared using a multivariate analysis of specific cognitive domains and univariate analyses of individual test scores. Dose–response relationships were explored within the marijuana-using group.

Results. Marijuana-using twins significantly differed from their non-using co-twins on the general intelligence domain; however, within that domain only the performance of the block design subtest of the Wechsler Adult Intelligence Scale – Revised reached a level of statistical significance.

Conclusions. Out of the numerous measures that were administered, only one significant difference was noted between marijuana-using twins and their non-using co-twins on cognitive functioning. The results indicate an absence of marked long-term residual effects of marijuana use on cognitive abilities.
Psychological distress and negative appraisals in survivors of severe acute respiratory syndrome (SARS)
Authors: CHENG S. K. W. , WONG C. W. , TSANG J. , WONG K. C.
Published: October 2004

Background. Severe acute respiratory syndrome (SARS) is a novel disease. The authors have limited knowledge of its impact on mental health. The present study aimed to examine the level and extent of psychological distress of SARS survivors following 1-month recovery, to explore patients' negative appraisals of the impact of SARS, and to evaluate the associations between psychological distress and negative appraisals.

Method. The Beck Anxiety Inventory, the Beck Depression Inventory, and a newly developed measure, the SARS Impact Scale (SIS), were mailed to 453 Hong Kong Chinese SARS survivors discharged from hospital for 4 weeks or more.

Results. A total of 425 patients received the questionnaires and 180 (mean age 36·9 years; 120 women) gave valid replies. The response rate was 42·4%. The participants also represented 13·6% of all adult survivors in Hong Kong. About 35% of respondents reported ‘moderate to severe’ or ‘severe’ ranges of anxiety and/or depressive symptoms. It was found that those working as healthcare workers or having family members killed by SARS were more prone to develop subsequent high levels of distress. Factor analyses extracted three meaningful factors of the SIS, namely ‘survival threat’, ‘physical impact’, and ‘social impact’. Negative appraisals at the acute phase and 1-month recovery significantly accounted for substantial portions of variances for anxiety and depressive symptoms, after the effects of other psychosocial variables were controlled.

Conclusions. Psychological distress of SARS survivors at 1-month recovery is real and significant. Negative appraisals may play a pivotal role in the development of psychological distress for SARS survivors, at least in the short term.