bluuebunny/crossref_metadata_2025 huggingface dataset:
Migration of elderly households in Canada, 1991–1996: determinants and differences
Authors: Marr William , Millerd Frank
Published: November 2004

The elderly, already a significant component of internal migration in Canada, will be an increasingly important element of future internal migration. Using census data on households, the flows and determinants of elderly migration are examined and compared with younger groups. Few migrate as individuals, most moves are multiple‐person moves, and the household, particularly the family, is the appropriate unit of analysis. In 1996 over 88% of those who migrated in the previous five years were members of households of two or more persons. The elderly are compared with the near‐elderly and those likely to be in the labour force, using the age of the primary household maintainer, a person named by each household, to classify households. The elderly are households with a primary household maintainer 65 years of age or over, the near‐elderly have a primary household maintainer of 55 to 64 years, and independent decision‐makers, the major component of the labour force, have a primary household maintainer aged 25 to 54. Significant differences are found between the groups. The elderly have a lower rate of migration and their migration determinants and destinations are less driven by employment considerations. While education, for example, is a consistently‐found determinant of migration for those in the labour force, it is much less significant for the elderly. The human capital model of migration is not applicable to the elderly. For couples both the characteristics of the primary household maintainer and the characteristics of the spouse or common‐law partner are determinants of the couple's migration, underlining the importance of modelling migration as a household move. Single‐person households often, but not always, show results similar to those for couples. When male and female single‐person households are compared, migration determinants usually have a stronger effect on females then on males. Copyright © 2004 John Wiley & Sons, Ltd.
Receptor‐based 3D QSAR Studies on PPARγ Agonists using CoMFA and CoMSIA Approaches
Authors: Hyun Kwan Hoon , Lee Do Young , Lee Bon‐Su , Kim Chan Kyung
Published: November 2004

Receptor‐based (RB) quantitative structure‐activity relationship (QSAR) studies were performed on the peroxisome proliferator‐activated receptors gamma (PPARγ) agonists with antihyperglycemic property using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) implemented in the SYBYL packages. The initial X‐ray structure of PPARγ with GI262570 agonist was used to sketch 36 training set molecules having the receptor bound conformation. These structures were subjected to subset energy minimization using TRIPOS force field and aligned against an α‐helix of PPARγ receptor. Four models were generated using CoMFA and CoMSIA with two different grid spacing, 2 Å and 1 Å. After PLS analysis, the best predicted CoMSIA model with grid spacing 1 Å, Model 4, showed that a leave‐one out (LOO) cross validated value (r$\rm{ {_{cv}^{2}}}$) and non‐cross validated conventional value (r$\rm{ {_{ncv}^{2}}}$) are 0.758 and 0.994, respectively. From the CoMFA and CoMSIA contour maps, important interactions crucial to strong binding to the receptor can be identified and verified. This information on the pharmacophore models can be used to design new ligands. Traditional ligand‐based (LB) QSAR studies were also performed using the global minima of the same training set molecules. Compared to LB QSAR study, advantage of using subset‐minimized RB QSAR study is discussed in detail.
2D‐ and 3D‐QSAR Models of Interaction between Flavor Compounds and beta‐Lactoglobulin Using Catalyst and Cerius2
Authors: Tromelin Anne , Guichard Elisabeth
Published: November 2004

See original QSAR Comb. Sci. 2004, 23, 214–233
Charge at the migrating hydrogen in the transition state of hydride transfer reactions from CH groups to hydride acceptors. Dynamics of the redox‐couple NADH‐NAD+
Authors: Buck Henk
Published: November 2004

We consider the controversial conclusions of the charge at the migrating hydrogen in the transition state of hydride‐transfer reactions from CH‐groups to hydride acceptors. Quantum chemical calculations were performed on elementary organic reactions involving carbenium ions, which can be considered as hydride acceptors. We also discuss the biochemical hydride‐transfer reactions in which the coenzyme NADH‐NAD+ plays an important role. With the calculations and the experimental model systems, an answer is given for the stereospecificity of the hydride transfer. Generally, the hydride transfer occurs via a trigonal pyramidal geometry in which the transferred hydride of the CH‐group is located in the axial position. In the case of the coenzyme NADH‐NAD+, the hydride transfer is coupled with an out‐of‐plane orientation of the carboxamide group of the pyridinium moiety, resulting in an increased stereospecificity. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Frontier example in experimental charge density research: Experimental electrostatics of proteins
Authors: Lecomte C. , Guillot B. , Jelsch C. , Podjarny A.
Published: November 2004

The experimental charge density methodology is extended to macromolecular structure and biocrystallography. Ultrahigh‐resolution diffraction data now can be collected at third‐generation synchrotron sources for well‐ordered protein crystals; the data can be refined with a more sophisticated model than the independent atom model (IAM), such as the multipolar atom. A new crystallographic program MoPro combining small molecules and macromolecular refinement method has been developed; first applications are described. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Capillary electrophoresis off‐line matrix‐assisted laser desorption/ionisation mass spectrometry of intact and digested proteins using cationic‐coated capillaries
Authors: Zuberovic Aida , Ullsten Sara , Hellman Ulf , Markides Karin E. , Bergquist Jonas
Published: November 2004

Capillary electrophoresis (CE) was coupled off‐line with matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS) for the analysis of proteins and peptides. CE fractions were collected directly on a matrix‐coated MALDI target, using a sheath‐flow interface. Protein adsorption during CE separations was prevented by coating the capillaries with the physically adsorbed, cationic polymer PolyE‐323. The CE/MALDI‐MS system was used for the analysis of model proteins and peptides at physiological pH as well as analysis of proteins in tear fluid. Moreover, tryptic on‐target digestion of the collected protein fractions, with subsequent MALDI‐MS and MS/MS peptide analysis, was demonstrated. Copyright © 2004 John Wiley & Sons, Ltd.
Atmospheric pressure chemical ionisation liquid chromatography/mass spectrometry of the ultraviolet screening pigment scytonemin: characteristic fragmentations
Authors: Squier Angela H. , Airs Ruth L. , Hodgson Dominic A. , Keely Brendan J.
Published: November 2004

Atmospheric pressure chemical ionisation reversed‐phase high‐performance liquid chromatography/multistage mass spectrometry has been used to study the mass spectral fragmentation of the cyanobacterial sheath pigment scytonemin and its reduced counterpart. The two pigments exhibit characteristic fragment ions in their MS2 and MS3 spectra that are of value in confirming the identification of the structures in extracts from natural environments. Copyright © 2004 John Wiley & Sons, Ltd.
Interfacial chemistry of adhesives on hydrated aluminium and hydrated aluminium treated with an organosilane
Authors: Watts John F. , Rattana Acharawan , Abel Marie‐Laure
Published: November 2004

The adsorption of a commercial adhesive and two of its major components—an amine curing agent [2,4‐toluene diisocyanate urone (TDI urone)] and an adhesive prepolymer resin [diglycidyl ether of bisphenol A (DGEBA)]—on a hydrated aluminium surface and the hydrated surface coated with γ‐glycidoxypropyltrimethoxysilane (GPS) has been investigated by x‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). The study of TDI urone adsorption indicated that adsorption was of the chemisorption type, and a specific interaction involving this molecule and the GPS immobilized on the hydrated aluminium surface was identified. From XPS and ToF‐SIMS data it was found that the types of interaction of the curing agent with the bare substrate were of the donor–acceptor type.

Study of the DGEBA adsorption showed different‐shaped isotherms for the bare and the GPS‐coated substrates. It was found that the typical Langmuir isotherm type was obtained for the GPS‐coated substrate whereas no adsorption plateau was observed for the bare substrate within the concentration range studied. This resulted from a change in the conformation of the DGEBA molecule on the substrate when the concentration of DGEBA solution was increased. The bonding of DGEBA with both types of substrates was assumed to be via acid–base interactions (i.e. donor–acceptor interactions).

Adsorption of the commercial adhesive on the hydrated surfaces was of BET Type IV form, rather than the simple monolayer adsorption isotherm (Langmuir type). This indicates multilayer adsorption, presumably in the pores of the hydrated substrate, as a result of a process analogous to adsorption condensation. Copyright © 2004 John Wiley & Sons, Ltd.
European trials with total mesorectal excision
Authors: Kapiteijn Ellen , van de Velde Cornelis J.H.
Published: November 2004

The outcome after surgery for rectal cancer differs markedly between patient series regarding local recurrence rates and survival. A high incidence of local recurrence is associated with conventional, nonstandardized procedures. To improve results of surgery, various additional treatments, such as radiotherapy, chemotherapy, and immunotherapy, have been tested. The Swedish Rectal Cancer Trial (SRCT) was the first trial to show that better local control achieved with preoperative radiotherapy resulted in improved survival. In recent years local control and survival have been further improved by the introduction of standardized total mesorectal excision (TME) surgery. A major problem of published studies on adjuvant therapy is that surgery was not standardized in these studies. Furthermore, quality control of the surgical technique by standardized pathological examination of the specimen is absent in most studies. In Europe, TME has become the preferred standard of operative management for rectal cancer. Adjuvant therapy studies should now be reexamined based on a platform of standardized, optimal surgery and pathology. We studied the European trials in which TME surgery is intentionally performed. Most of these trials are still in progress, with follow‐up too short for definitive results, apart from interim analyses. However, the Dutch TME trial has already shown that performing a large, multicenter trial with quality control of both surgery and pathology is feasible. Semin. Surg. Oncol. 19:350–357, 2000. © 2000 Wiley‐Liss, Inc.
Nodularin uptake by seafood during a cyanobacterial bloom
Authors: Van Buynder P. G. , Oughtred T. , Kirkby B. , Phillips S. , Eaglesham G. , Thomas K. , Burch M.
Published: November 2004

The problem of blue‐green algal toxin contamination of recreational waters and drinking water catchments is well described, as is the potential contamination of associated seafood. Algal contamination of Victorian waterways is now a widespread annual occurrence and, in some regions, the intersection of blooms and commercial fishing threatens the food safety of large numbers of people. Toxin levels which produce no observed adverse effect in animal studies were used to derive safe tolerable daily intake levels. These ‘acceptable levels’ were then modified to protect against potential acute health risks associated with short‐term exposures. National food surveys were used to derive likely seafood intakes and thus, in combination with ‘safe toxin levels’, health alert levels for seafood were formulated. During the summer of 2001 a bloom of Nodularia spumigena occurred in the Gippsland Lakes area of Southern Victoria. During the bloom, seafood samples were collected and nodularin concentrations were estimated. Nodularin concentrations reached levels of concern in mussels and in prawn viscera at cell counts as low as 30,000 cells/ml. Nodularin concentrations in the flesh of finfish remained low. Boiling the seafood redistributed toxin between viscera and flesh. The results were used to restrict some seafood harvesting. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 468–471, 2001
Cytological alterations in isolated hepatocytes from common carp (Cyprinus carpio L.) exposed to microcystin‐LR
Authors: Li XiaoYu , Liu YongDing , Song LiRong
Published: November 2004

Microcystin‐LR (MC‐LR) is the most commonly encountered of the toxic cyclic peptide hepatotoxins occurring in China. It is a model compound for toxicological studies. In this study, the toxicity of MC‐LR (50 and 500 μg/L) on isolated carp hepatocytes was determined and the ultrastructural alterations of cells induced by MC‐LR were observed. The alterations noted when hepatocytes were exposed to 50 μg/L MC‐LR were blebbing of cell membrane, shrinking and deformation of nuclei, vesiculation and transformation into concentric membrane whorls of RER, and swelling and rearrangement of the cytoskeleton. However, when the cells were exposed to 500 μg/L MC‐LR, broken cell membranes, nuclei and cytoskeleton could be observed. These ultrastructural changes paralleled the pathological events, which lead to apoptosis or necrosis of hepatocytes. These results suggest that disruption of the cytoskeletal structures could account for the blebbing of cell membrane and apoptosis induced by MC‐LR. © 2001 John Wiley & Sons, Inc. Environ Toxicol, 16: 517–522, 2001
Characterisation of a gene cluster involved in bacterial degradation of the cyanobacterial toxin microcystin LR
Authors: Bourne David G. , Riddles Peter , Jones Gary J. , Smith Wendy , Blakeley Robert L.
Published: November 2004

A novel pathway for degradation of the cyanobacterial heptapeptide hepatotoxin microcystin LR was identified in a newly isolated Sphingomonas sp. (Bourne et al. 1996 Appl. Environ. Microbiol. 62: 4086–4094). We now report the cloning and molecular characterisation of four genes from this Sphingomonas sp. that exist on a 5.8‐kb genomic fragment and encode the three hydrolytic enzymes involved in this pathway together with a putative oligopeptide transporter. The heterologously expressed degradation pathway proteins are enzymatically active. Microcystinase (MlrA), the first enzyme in the degradative pathway, is a 336‐residue endopeptidase, which displays only low sequence identity with a hypothetical protein from Methanobacterium thermoautotrophicum. Inhibition of microcystinase by EDTA and 1,10‐phenanthroline suggests that it is a metalloenzyme. The most likely residues that could potentially chelate an active‐site transition metal ion are in the sequence HXXHXE, which would be unique for a metalloproteinase. Situated immediately downstream of mlrA with the same direction of transcription is a gene mlrD, whose conceptual translation (MlrD, 442 residues) shows significant sequence identity and similar potential transmembrane spanning regions to the PTR2 family of oligopeptide transporters. A gene mlrB is situated downstream of the mlrA and mlrD genes, but transcribed in the opposite direction. The gene encodes the enzyme MlrB (402 residues) which cleaves linear microcystin LR to a tetrapeptide degradation product. This enzyme belongs to the “penicillin‐binding enzyme” family of active site serine hydrolases. The final gene in the cluster mlrC, is located upstream of the mlrA gene and is transcribed in the opposite direction. It codes for MlrC (507 residues) which mediates further peptidolytic degradation of the tetrapeptide. This protein shows significant sequence identity to a hypothetical protein from Streptomyces coelicolor. It is suspected to be a metallopeptidase based on inhibition by metal chelators. It is postulated on the basis of comparison with other microorganisms that the genes in this cluster may all be involved in cell wall peptidoglycan cycling and subsequently act fortuitously in hydrolysis of microcystin LR. © 2001 John Wiley & Sons, Inc. Environ Toxicol, 16: 523–534, 2001
Population growth impairment of sulfur‐containing compounds to Tetrahymena pyriformis
Authors: Schultz T. Wayne , Sinks Glendon D. , Miller Lisa A.
Published: November 2004

A series of 37 aliphatic and aromatic sulfur‐containing compounds were evaluated in 2‐day Tetrahymena pyriformis population growth impairment assay. The results indicate that, except for select compounds, the in‐ring sulfur‐containing compounds, sulfates, sulfites, thiols, sulfones, and sulfoxides model as neutral and noncovalent‐reacting narcotics. Abiotic loss due to volatility appears to interfere in accurate model prediction because actual toxicity was less than predicted. Vinyl sulfones and sulfoxides are more toxic than predicted using neutral narcosis. Tetrahymena exposed to methyl vinyl sulfone exhibits a direct relationship between the exposure concentration and the generation times with no lag phase in growth. As such, these population growth kinetics mimic those reported for hydrophilic neutral narcotics (i.e., ethanol and acetone). Tetrahymena exposed to phenyl vinyl sulfone exhibit a long concentration‐dependent lag phase, which is followed by population growth at rates not different from controls. These population growth kinetics are similar but more dramatic than those reported for hydrophobic neutral narcotics (i.e., butylbenzene and 2‐decanone). These results are useful in that they imply that sulfur‐containing compounds for the most part act as simple narcotics. Therefore, their toxicity can be modeled with simple structure‐toxicity relationships without much fear of underestimation of potency. © 2001 John Wiley & Sons, Inc. Environ Toxicol, 16: 543–549, 2001
Comparative sensitivity of embryo–larval toxicity assays with African catfish (Clarias gariepinus) and zebra fish (Danio rerio)
Authors: Nguyen Lien T. H. , Janssen Colin R.
Published: November 2004

Embryo–larval toxicity tests with the African catfish (Clarias gariepinus) were conducted with five chemicals (Cr, Cd, Zn, NaPCP and malathion) and three environmental samples. The sensitivity of the 5‐day assay was compared to that of the 12‐day embryo–larval toxicity tests with the zebra fish (Danio rerio). The ratios of the C. gariepinus and D. rerio LC50 values ranged from 0.4 for Cr to 8.9 for Zn. The ratios of subchronic values ranged from 0.25 for NaPCP to 3.1 for Cd indicating a more comparable sensitivity of the two species. For the three sediment pore waters, the ratios were 0.6, 1.1, and 2.4 and the subchronic values were identical for the two species. The results suggest that, considering the short‐test duration and its sensitivity, the 5‐day embryo–larval tests with C. gariepinus may be a potential alternative for short‐term embryo–larval toxicity testing with fish. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 566–571, 2001
The cross‐sectional study of the health effects of occupational exposure to carbon disulfide in a Chinese viscose plant
Authors: Tan Xiaodong , Wang Fuyuan , Bi Yongyi , Su YongJun , Li Yang , He Jun , Yi Pinfan , Yan Jun , de Bacquer Dirk , Braeckman Lutgart , Vanhoorne Michel
Published: November 2004

This article presents results of carbon disulfide exposure assessment in a Chinese viscose rayon factory and represents the cross‐sectional study beginning phase of the occupational epidemiological project. The authors measured external exposure levels to carbon disulfide at a Chinese viscose rayon factory and monitored results as internal exposure indexes by testing urine samples of workers exposed to carbon disulfide levels. The rate at which carbon disulfide is metabolized by exposed subjects was demonstrated by 2‐thio‐thiazolidine‐4‐carboxylic acid (TTCA) concentrations in urine of exposed subjects, which was studied to determine best time points for internal exposure sampling. Carbon disulfide concentrations in the air of the workplace were analyzed with gas chromatography with flame photometric detector (GC‐FPD); presence of TTCA in urine samples of subjects was determined using a modified high‐performance liquid chromatography method. Kinetics of TTCA excretion was studied by analysis at different time points during and after exposure of workers to carbon disulfide. A total of 155 personal samples were obtained. Carbon disulfide concentration at staple viscose hall was found to be 13.72±1.12 mg/m3 in terms of geometric mean and geometric standard deviation. Carbon disulfide concentration at filament spinning hall was found to be 20.05±1.33 mg/m3. TTCA values of subjects at staple spinning hall were 1.18±0.43 and 1.07±0.38 mg/g creatinine for subjects working at filament spinning hall. The best time for TTCA sampling is at the end of the exposure–working shift. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 377–382, 2001
Asp177 in C4 domain of mouse sphingosine kinase 1a is important for the sphingosine recognition
Authors: Yokota Shinji , Taniguchi Yuki , Kihara Akio , Mitsutake Susumu , Igarashi Yasuyuki
Published: November 2004

Sphingosine kinase (SK) is the enzyme that catalyzes the formation of sphingosine 1‐phosphate (S1P). Although diverse biological functions have been reported for SK, its recognition site for its substrate sphingosine (Sph) is still unclear. We constructed various mutants of mouse sphingosine kinase 1a (mSK1a), carrying mutations in the C4 domain, which we had expected to encompass the Sph‐binding site. We analyzed the influence of these mutations on the SK activity and substrate kinetics. One mutation, Asp177
→ Asn177, caused a dramatic decrease in SK activity (to ∼6% of wild type) and an increase in the K
m value for Sph (10.1 → 108 μM), with no change in the affinity for ATP. This result suggests that the C4 domain, especially the Asp177, is involved in the specific recognition of Sph. In this report, we are able, for the first time, to provide an account of the Sph‐binding site of SK.
Early Active Mobilization of Primary Repairs of the Flexor Pollicis Longus Tendon with Two Kessler Two-Strand Core Sutures and a Strengthened Circumferential Suture
Authors: SIROTAKOVA M. , ELLIOT D.
Published: November 2004

This study reports our treatment of divided flexor pollicis longus (FPL) tendons by primary repair from 1999 to 2002. Forty-eight FPL repairs were performed using two Kessler two-strand repairs with a cross-linked Silfverskiöld circumferential suture. All were rehabilitated by early active mobilization. Excellent or good results were observed in 73/77% of cases (White/Buck–Gramcko assessments, respectively). No patients (0%) ruptured their repair as a result of early active mobilization. Two patients (4%) developed post-operative infections with wound and tendon dehiscence. This combination of repairs addresses the problem of rupture of FPL during early mobilization which we experienced in previous studies. Its problems and alternatives are discussed.
The Non-Opposable Triphalangeal Thumb: A New Technique of Management
Authors: EL-KAREF ESSAM
Published: November 2004

Fifteen non-opposable triphalangeal thumbs (eight patients) were treated with a new two-staged surgical technique. The first stage included excision of the proximal interphalangeal joint and osteotomy of the thumb metacarpal, and aimed to restore a correct thumb length, position and alignment and to create a wide thumb web space. The second stage consisted of an opponensplasty with refining of any of the first stage components, as necessary. The mean age at surgery was 3.2 years (range, 2.5–6 years). After a mean follow-up period of 42 months (range, 26 months to 7 years), the targets of treatment had been accomplished without loss of growth potential, joint stability or thumb motion. All children had improved function and cosmesis of the hand.
Pseudosyndactyly and Musculoskeletal Contractures in Inherited Epidermolysis Bullosa: Experience of the National Epidermolysis Bullosa Registry, 1986–2002
Authors: FINE J.-D. , JOHNSON L.B. , WEINER M. , STEIN A. , CASH S. , DELEOZ J. , DEVRIES D.T. , SUCHINDRAN C.
Published: November 2004

Mitten deformities of the hands and feet occur in nearly every patient with the most severe subtype (Hallopeau-Siemens) of recessive dystrophic epidermolysis bullosa, and in at least 40–50% of all other recessive dystrophic epidermolysis bullosa patients. Smaller numbers of patients with dominant dystrophic, junctional, and simplex types of epidermolysis bullosa are also at risk of this complication. Surgical intervention is commonly performed to correct these deformities, but recurrence and the need for repeated surgery are common. Higher numbers of epidermolysis bullosa patients also develop musculoskeletal contractures in other anatomic sites, further impairing overall function. Lifetable analyses not only better project the cumulative risk of mitten deformities and other contractures but also emphasize the need for early surveillance and intervention, since both of these musculoskeletal complications may occur within the first year of life.
Isolation and characterization of libraries of monoclonal antibodies directed against various forms of tubulin in Paramecium
Authors: Callen Anne‐Marie , Adoutte André , Andrew Jose Manuel , Baroin‐Tourancheau Anne , Bré Marie‐Hélène , Ruiz Purificacion Calvo , Clérot Jean‐Claude , Delgado Pilar , Fleury Anne , Jeanmaire‐Wolf Rachel , Viklicky Vladimir , Villalobo Eduardo , Levilliers Nicolette
Published: November 2004

Summary— Ciliates are very good models for studying post‐translationally generated tubulin heterogeneity because they exhibit highly differentiated microtubular networks in combination with reduced genetic diversity. We have approached the analysis of tubulin heterogeneity in Paramecium through extensive isolation and characterization of monoclonal antibodies using various antigens and several immunization protocols. Eight monoclonal antibodies and 10 hybridoma supernatants were characterized by: i) immunoblotting on ciliate and pig brain tubulins as well as on peptide maps of Paramecium axonemal tubulin; ii) immunoblotting on ciliate tubulin fusion peptides generated in E coli, a procedure which allows in principle to discriminate antibodies that are directed against tubulin sequence (reactive on fusion peptides) from those directed against a post‐translational epitope (non‐reactive); and iii) immunofluorescence on Paramecium, 3T3 and PtK2 cells. Twelve antibodies labeled all microtubules in Paramecium cells and were found to be directed against tubulin primary sequences (nine of them being located in the α N‐terminal domain, one in the β C‐terminal one, and two in α and β central stretches). The remaining ones decorated only a specific subset of microtubules within the cell and were presumably directed against post‐translational modifications. Among these, three antibodies are directed against an N‐terminal acetylated epitope of α‐tubulin whereas the epitopes of three other ones (TAP 952°, AXO 58 and AXO 49°) apparently correspond to still unidentified post‐translational modifications, located in the C‐terminal domain of both α‐ and β‐tubulins. The AXO 49° specificity is similar to that of a previously described polyclonal serum raised against Paramecium axonemal tubulin [2]. The results are discussed in terms of identification and accessibility of the epitopes and immunogenicity of ciliate tubulin with reference to mammalian and ciliate tubulin sequences.
Dynamics of Mount Etna Volcano inferred from static and kinematic GPS measurements
Authors: Puglisi Giuseppe , Bonforte Alessandro
Published: November 2004

Ground deformations measured on Mount Etna from late 1995 to mid‐1998 using GPS observations are analyzed. Four GPS surveys were carried out during the considered period. In 1995 the GPS network consisted of 18 stations on the volcanic edifice and 6 stations around it. During the 1996 survey, 22 new monuments were added along a N‐S profile crossing the summit craters area. This profile was surveyed by a semikinematic method, allowing greater spatial detail to be achieved on the uppermost part of the volcano. The comparisons between the GPS surveys are reported here in terms of horizontal and vertical displacements for each station and also in terms of areal dilatation and strain distribution. This last parameter continues its ascending trend, at a rate of ∼5 μstrain yr−1, already shown in the previous period, after the end of the 1991–1993 flank eruption. Inversion of the ground deformation patterns permits investigation of the evolution of both the position and dynamics of magma reservoirs beneath the volcano, consistently associated with a general eastward sliding of its eastern sector. This study allows us to define the nonuniqueness of ground deformation sources through the investigated period, suggesting that the plumbing system of the volcano is made up of a complex system of single intrusions occurring at different times.
Associated water and organic compounds in coral skeletons: Quantitative thermogravimetry coupled to infrared absorption spectrometry
Authors: Cuif Jean‐Pierre , Dauphin Yannicke , Berthet Patrick , Jegoudez Jocelyne
Published: November 2004

Samples from coral skeletons belonging to six species have been submitted to thermogravimetric analysis in the temperature range between 20° and 550°C. Weight losses are interpreted on the basis of simultaneously recorded infrared absorption spectra at specific wavelengths for water and CO2. The organic + water content of coral skeletons represents up to 2.5% of the total weight. Additionally, it is shown that during heating the main part of water remains linked to organic compounds up to 275°–330°C, suggesting organic materials associated with the skeleton are hydrated.
Crystal structure of yeast V‐ATPase subunit C reveals its stator function
Authors: Drory Omri , Frolow Felix , Nelson Nathan
Published: November 2004

Vacuolar H+‐ATPase (V‐ATPase) has a crucial role in the vacuolar system of eukaryotic cells. It provides most of the energy required for transport systems that utilize the proton‐motive force that is generated by ATP hydrolysis. Some, but not all, of the V‐ATPase subunits are homologous to those of F‐ATPase and the nonhomologous subunits determine the unique features of V‐ATPase. We determined the crystal structure of V‐ATPase subunit C (Vma5p), which does not show any homology with F‐ATPase subunits, at 1.75 Å resolution. The structural features suggest that subunit C functions as a flexible stator that holds together the catalytic and membrane sectors of the enzyme. A second crystal form that was solved at 2.9 Å resolution supports the flexible nature of subunit C. These structures provide a framework for exploring the unique mechanistic features of V‐ATPases.
A technique to identify solvable dynamical systems, and another solvable extension of the goldfish many-body problem
Authors: Calogero Francesco
Published: November 2004

We take advantage of the simple approach, recently discussed, which associates to (solvable) matrix equations (solvable) dynamical systems interpretable as (interesting) many-body problems, possibly involving auxiliary dependent variables in addition to those identifying the positions of the moving particles. Starting from a solvable matrix evolution equation, we obtain the corresponding many-body model and note that in one case the auxiliary variables can be altogether eliminated, obtaining thereby an (also Hamiltonian) extension of the “goldfish” model. The solvability of this novel model, and of its isochronous variant, is exhibited. A related, as well solvable, model, is also introduced, as well as its isochronous variant. Finally, the small oscillations of the isochronous models around their equilibrium configurations are investigated, and from their isochronicity certain diophantine relations are evinced.
Deletion of the Chloroplast-Localized Thylakoid Formation1 Gene Product in Arabidopsis Leads to Deficient Thylakoid Formation and Variegated Leaves
Authors: Wang Qin , Sullivan Rusty W. , Kight Alicia , Henry Ralph L. , Huang Jirong , Jones Alan M. , Korth Kenneth L.
Published: November 2004

Development of thylakoid membranes depends upon the transport of membrane vesicles from the chloroplast inner envelope and subsequent fusion of vesicles within the interior of the plastid. The Arabidopsis (Arabidopsis thaliana) Thylakoid formation1 (Thf1) gene product is shown here to control an important step required for the normal organization of these vesicles into mature thylakoid stacks and ultimately for leaf development. The Arabidopsis Thf1 gene encodes an imported chloroplast protein, as shown by in vitro import and localization of a Thf1-green fluorescent protein fusion product in transgenic plants. This gene is conserved in oxygenic photoautotrophs ranging from cyanobacteria to flowering land plants. Transcript levels for Thf1 are induced in the light and decrease under dark conditions, paralleling profiles of light-regulated nuclear genes involved in chloroplast function. Disruption of the Thf1 gene via T-DNA insertion results in plants that are severely stunted with variegated leaf patterns. Nongreen sectors of variegated leaves lacking Thf1 expression contain plastids that accumulate membrane vesicles on the interior and lack organized thylakoid structures. Green sectors of Thf1-disrupted leaves contain some chloroplasts that form organized thylakoid membranes, indicating that an inefficient compensatory mechanism supports thylakoid formation in the absence of Thf1. Genetic complementation of a Thf1 knockout line confirms the role of this gene in chloroplast and leaf development. Transgenic plants expressing the Thf1 gene in antisense orientation are stunted with altered thylakoid organization, especially in young seedlings. The data indicate that the Thf1 gene product plays a crucial role in a dynamic process of vesicle-mediated thylakoid membrane biogenesis.
A Stromal Hsp100 Protein Is Required for Normal Chloroplast Development and Function in Arabidopsis
Authors: Constan Diane , Froehlich John E. , Rangarajan Sowkya , Keegstra Kenneth
Published: November 2004

Molecular chaperones are required for the translocation of many proteins across organellar membranes, presumably by providing energy in the form of ATP hydrolysis for protein movement. In the chloroplast protein import system, a heat shock protein 100 (Hsp100), known as Hsp93, is hypothesized to be the chaperone providing energy for precursor translocation, although there is little direct evidence for this hypothesis. To learn more about the possible function of Hsp93 during protein import into chloroplasts, we isolated knockout mutant lines that contain T-DNA disruptions in either atHSP93-V or atHSP93-III, which encode the two Arabidopsis (Arabidopsis thaliana) homologs of Hsp93. atHsp93-V mutant plants are much smaller and paler than wild-type plants. In addition, mutant chloroplasts contain less thylakoid membrane when compared to the wild type. Plastid protein composition, however, seems to be largely unaffected in atHsp93-V knockout plants. Chloroplasts isolated from the atHsp93-V knockout mutant line are still able to import a variety of precursor proteins, but the rate of import of some of these precursors is significantly reduced. These results indicate that atHsp93-V has an important, but not essential, role in the biogenesis of Arabidopsis chloroplasts. In contrast, knockout mutant plants for atHsp93-III, the second Arabidopsis Hsp93 homolog, had a visible phenotype identical to the wild type, suggesting that atHsp93-III may not play as important a role as atHsp93-V in chloroplast development and/or function.
Small-angle neutron and X-ray scattering of dispersions of oleic-acid-coated magnetic iron particles
Authors: Butter Karen , Hoell Armin , Wiedenmann Albrecht , Petukhov Andrei V. , Vroege Gert-Jan
Published: November 2004

This paper describes the characterization of dispersions of oleic-acid-coated magnetic iron particles by small-angle neutron and X-ray scattering (SANS and SAXS). Both oxidized and non-oxidized dilute samples were studied by SANS at different contrasts. The non-oxidized samples are found to consist of non-interacting superparamagnetic single dipolar particles, with a lognormal distribution of iron cores, surrounded by a surfactant shell, which is partially penetrated by solvent. This model is supported by SAXS measurements on the same dispersion. Small iron particles are expected to oxidize upon exposure to air. SANS was used to study the effect of this oxidation, both on single particles, as well as on interparticle interactions. It is found that on exposure to air, a non-magnetic oxide layer is formed around the iron cores, which causes an increase of particle size. In addition, particles are found to aggregate upon oxidation, presumably because the surfactant density on the particle surfaces is decreased.
High-throughput powder diffraction. IV. Cluster validation using silhouettes and fuzzy clustering
Authors: Barr Gordon , Dong Wei , Gilmore Christopher J.
Published: November 2004

In two previous papers [Gilmore, Barr & Paisley (2004).J. Appl. Cryst.37, 231–242; Barr, Dong & Gilmore (2004).J. Appl. Cryst.37, 243–252], it was demonstrated how to generate a correlation matrix by comparing full powder diffraction patterns, and then partition the diffractograms into groups using multivariate statistics and associated classification procedures. For clustering the patterns into related sets, dendrograms, metric multidimensional scaling and three-dimensional principal-components analysis score plots are employed. However, sometimes cluster membership for certain patterns is not always very clear or other ambiguities may arise; this paper describes cluster validation techniques using silhouettes and fuzzy clustering. The two methods operate in a complementary way: in some cases silhouettes are the most useful, and in others fuzzy clustering is more applicable. These procedures are available as options in the commercial computer programPolySNAP.
MODY: a program for calculation of symmetry-adapted functions for ordered structures in crystals
Authors: Sikora Wiesława , Białas Franciszek , Pytlik Lucjan
Published: November 2004

This paper describes a computer program, based on the theory of groups and representations, which calculates symmetry-adapted functions used for the description of various ordered structures in crystals. It is assumed that the ordered structure, which is formed by a configuration of occupational probabilities, ion displacements, magnetic moments, quadrupolar moments or other local physical quantities, is obtained from a high-symmetry crystal structure with a given space groupG, as a result of a symmetry-lowering phase transition. The detailed characteristics of the phase transition are given by the specification of the irreducible representations of groupG, active in the transition. The symmetry-adapted functions obtained from the calculation are perfect tools for the construction of model structures, which can be used for comparison with experimental (e.g.neutron diffraction) data, and can be a great help in numerical data elaboration by reducing the number of adjustable parameters describing the structure of a given symmetry.
The structure of ZrO2phases and devitrification processes in a Ca–Zr–Si–O-based glass ceramic: a combined a-XRD and XAS study
Authors: Meneghini C. , Mobilio S. , Lusvarghi L. , Bondioli F. , Ferrari A. M. , Manfredini T. , Siligardi C.
Published: November 2004

The structure of the Zr atomic environment in a CaO–ZrO2–SiO2glass ceramic as a function of thermal treatments has been studied, combining X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD) and anomalous XRD (a-XRD) techniques. The analysis of XRD patterns demonstrates that the devitrification process proceeds through the partial segregation of Zr-depleted phases (wollastonite-like) and Zr-rich phases (Zr oxides). The XAS and a-XRD measurements at the ZrK-edge have been exploited in order to obtain a closer insight into the atomic structure around the Zr atoms. In the as-quenched glass the Zr atom is sixfold coordinated to O atoms in an amorphous environment rich in Ca and Si. Thermal treatment firstly (T= 1273–1323 K) causes partial segregation of Zr in the form of an oxide with a tetragonal zirconia (t-ZrO2) crystalline structure. Raising the temperature (T= 1373 K) causes the formation of ZrO2crystallites in the monoclinic crystallographic phase (baddeleyite, m-ZrO2). Analysis of the XAS data shows that a considerable amount of Zr remains in an amorphous calcium silicate phase.
Multi-wavelength anomalous diffraction method for I and Xe atoms using ultra-high-energy X-rays from SPring-8
Authors: Takeda Kazuki , Miyatake Hideyuki , Park Sam-Yong , Kawamoto Masahide , Kamiya Nobuo , Miki Kunio
Published: November 2004

The first successful multi-wavelength anomalous diffraction (MAD) experiments using ultra-high-energy X-rays (∼35 keV) were performed for iodine and xenon derivatives of hen egg-white lysozyme crystals. The beamline BL41XU of SPring-8 enabled the collection of high-quality MAD data, which led to the calculation of anomalous or dispersive difference Patterson maps that determined the positions of iodine and xenon atoms. The electron density maps obtained by the density modification method for both cases proved to be of sufficient quality for building molecular models. I-MAD and Xe-MAD phasing are now available at SPring-8, and the utilization of ultra-high-energy X-rays will make a significant contribution to the solution of the phase problem in protein crystallography.
Temperature characteristics of crystal storage devices in a CP100 dry shipping Dewar
Authors: Owen Robin Leslie , Pritchard Mike , Garman Elspeth
Published: November 2004

With the advent of `courier crystallography', the safe and reliable transportation of cryo-cooled crystals in dry Dewars has become an important factor in the outcome of an experiment. The results of measurements of the long-term temperature characteristics of a dry Dewar are presented, together with the variation in properties of a `cryo-vial', a `kryo-vial' and a Rigaku MSC ACTOR `puck'. The short-term effects of removing and replacing the top-hat (`cryo-cap') holder from the Dewar have also been investigated, and the implications for best practice on synchrotron trips are discussed.
Sodium Technological functions of salt in the manufacturing of food and drink products
Authors: Hutton Tim
Published: November 2004

Salt (sodium chloride) is used in a variety of processed foods. It not only confers its own specific flavour on products, it is also used to enhance and modify the flavour of other ingredients. The reasons for using salt can be divided into three broad categories: processing reasons, sensory (taste) reasons, and preservative reasons. In some cases it performs all three of these functions, and in many situations the distinction between them is not clear‐cut.
Effectiveness of on‐the‐job training
Authors: van der Klink Marcel R. , Streumer Jan N.
Published: November 2004

Investigates the effectiveness of on‐the‐job training (OJT). Presents a definition of OJT used for this research project which involved two studies: the first in the call centres of a large company, and the second in post offices. Gives the results of the study which indicate the OJT programs were only partially successful in realising training goals. Indicates that self‐efficacy, prior experience with tasks, managerial support and workload were the most powerful predictors for training effectiveness. Concludes that the evidence suggests that OJT is not entirely an effective training method although more research is needed in this area.
Selection for digital preservation
Authors: Seadle Michael
Published: November 2004

This editorial discusses long‐term archiving and long‐term access to digital documents, with an emphasis on criteria for selection. Selecting materials for digital preservation depends on whether the materials are both valuable and endangered, whether appropriate digitization procedures and standards for these materials exist, and whether copyright allows reasonable access for educational and research purposes.
Descriptive and normative research on organizational learning: locating the contribution of Argyris and Schön
Authors: Robinson Viviane M.J.
Published: November 2004

The dual purpose of this paper is to locate the contribution of Argyris and Schon to the field of organisational learning, and to discuss aspects of their work which are particularly distinctive or controversial. There are two distinct strands of research on organisational learning. The descriptive strand, with its roots in social and cognitive psychology, seeks to understand the processes by which organisations learn and adapt. The normative strand, which is sometimes referred to as research on the “learning organization”, is concerned more with how organisations can direct their learning in ways that bring them closer to an ideal. While Argyris and Schon, with their emphasis on intervention and improvement, belong to the latter normative strand, they have also contributed greatly to the descriptive strand because their normative theorising is grounded in detailed empirical study of organisational processes. The article contrasts Argyris and Schon’s account of learning as the manipulation of symbolic representations of organisational life, with the non‐symbolic, feedback‐driven account of learning offered by many descriptive researchers. It suggests how these two accounts could be integrated by recognising that differing tasks or problems require different learning processes and different types of expertise. This more differentiated approach casts doubt on the notion of a generically capable “learning organisation”. The paper concludes with a call for more researchers to bridge the divide between the descriptive and normative strands of research on organisational learning.
Cell‐selective viral gene delivery vectors for the vasculature
Authors: Baker Andrew H. , Kritz Angelika , Work Lorraine M. , Nicklin Stuart A.
Published: November 2004

Clinical gene therapy for cardiovascular disease remains achievable. To date, however, preclinical studies and clinical trials have highlighted shortfalls in viral gene delivery to vascular cells. These include poor efficiency, poor target tissue selectivity, the presence of pre‐existing neutralizing antibodies and immunogenicity generated by the host to vectors such as adenovirus. These important issues require careful consideration when applying viral vectors for gene therapy. Each delivery vector requires precise optimization and tailoring for each disease application since parameters relating to vector : tissue exposure time, route of delivery and target cell type vary considerably. Optimization can be achieved through modification of the structure of the virus capsid proteins and expression cassette to generate vectors that are highly selective and efficient for target cell binding and entry as well as instilling transcriptional control and/or longevity on transgene expression. This ultimately will improve the efficacy and toxicity profiles of gene delivery vectors and has become a very important area in gene therapy. Here, we review recent advances in the targeting of viral gene delivery vectors to the vasculature.