bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge‐system theory in society: Charting the growth of knowledge‐system models over a decade, 1994–2003
Authors: Graham Paul J. , Dickinson Harley D.
Published: October 2007

The second half of the twentieth century saw the emergence of three knowledge‐system models: Mode 2 knowledge production, the Triple Helix, and Post‐Normal Science (PNS). Today, this emphasis on knowledge use is the focus of such important health movements as evidence‐based medicine. Building on the methodological work of Shinn (2002) and the theoretical work of Holzner and Marx (1979), we conducted a bibliometric study of the extent to which the three knowledge‐system models are used by researchers to frame problems of health‐knowledge use. By doing so, we reveal how these models fit into a larger knowledge system of health and evidence‐based decision making. The study results show clearly that although these knowledge models are extremely popular for contextualizing research, there is a distinct lack of emphasis on use of the models in knowledge utilization or evidence‐based medicine. We recommend using these models for further research in three specific dimensions of health systems analysis: (a) differences in language use, (b) transformative thinking about health‐knowledge functions, and (c) ethical analysis of institutional linkages.
Neubau von zwei Fuß‐ und Radwegbrücken in Dortmund
Authors: Sobek Werner , Engelsmann Stephan
Published: October 2007

Der Neubau von zwei innerstädtischen Fuß‐ und Radwegbrücken in Dortmund war Teil des “Maßnahmenkatalogs Verkehr” für die Fußballweltmeisterschaft 2006. Gestaltkonzept und Erscheinungsbild der Tragstrukturen sind abgeleitet aus der Wegeführung. Die beiden Brückenbauwerke bilden eine nachhaltige Investition in Verkehrsbauten in urbanen Räumen. Der Beitrag beschreibt die Objektplanung und die Tragwerksplanung für die beiden Brückenbauwerke sowie deren Tragverhalten.
Untersuchungen zum Werkstoffverhalten des Feinkornbaustahls S 460 unter erhöhten Temperaturen
Authors: Lange Jörg , Wohlfeil Ninja
Published: October 2007

Die Bestimmung der Tragfähigkeit von Bauteilen aus S 460 im Brandfall auf der Grundlage vereinfachter oder allgemeiner Berechnungsverfahren entsprechend EN 1993‐1‐2 [1] erfordert die Kenntnis der mechanischen Eigenschaften des hochfesten Feinkornbaustahls unter erhöhten Temperaturen. Hierzu wurden Untersuchungen an Probestäben aus einem normalisierend gewalzten S 460 N und einem thermomechanisch gewalzten S 460 M durchgeführt. Beide Stahlsorten unterscheiden sich sowohl in ihrer chemischen Zusammensetzung als auch in der Temperaturführung beim Walzen. Auf der Grundlage instationärer Warmkriechversuche wurden Werkstoffgesetze für den Temperaturbereich von 20 bis 900 °C hergeleitet. Die Untersuchungen zeigen eine im Vergleich zu S 460 N erhöhte Festigkeit des S 460 M bei hohen Temperaturen. Diese ist zurückzuführen auf die durch das thermomechanische Walzen verursachte Verfestigung und die Verringerung der Kriechgeschwindigkeit durch Niob‐ und Titanausscheidungen. Beim Vergleich der Ergebnisse mit den in EN 1993‐1‐2 [1] für S 460 angegebenen Werkstoffgesetzen erkennt man, dass diese sowohl die Festigkeit als auch die Steifigkeit des untersuchten S 460 N überschätzen.
Exploring the relationship between poverty, childhood adversity and child abuse from the perspective of adulthood
Authors: Frederick John , Goddard Chris
Published: October 2007

A recent Australian study of people experiencing poverty, involving in‐depth interviews with 20 participants, suggests that a complex process leading to poverty in adult life can stem from abusive and adverse experiences in childhood. It is considered that these experiences of abuse and adversity may begin a process of ‘negative chain effects’ (Rutter, 2000) resulting in a pathway into poverty caused by ‘accumulated adversity’ (Seth‐Purdie, 2000). The development and maintenance of human capital, defined as the sum of a person's physical, psychological and economic capabilities, are strongly influenced by the extent of adversity experienced over a person's life course, particularly experiences of adversity in early childhood (Seth‐Purdie, 2000). In this paper, the experiences of childhood abuse and adversity reported by the interviewees will be outlined and discussed in the light of theory and research related to development during childhood and adolescence. Copyright © 2007 John Wiley & Sons, Ltd.
Listen to Me! Children's experiences of domestic violence
Authors: Buckley Helen , Holt Stephanie , Whelan Sadhbh
Published: October 2007

This paper reports on a study undertaken in the Republic of Ireland during 2005 and is based on the experiences of children and young people who have lived with domestic violence. The objectives of the study were to explore the impact of domestic violence on children, identify their needs and recommend appropriate interventions to be brokered through a centrally based women's support service. Data were gathered from 70 participants, including 37 service providers/volunteers, 11 mothers and 22 children and young people who had lived in violent environments. The data indicated that children respond in unique ways to living with domestic violence, and that services to meet their needs must be tailored to suit their individual situations. The impact of domestic violence on their lives manifested itself with regard to their sense of fear and anxiety in relation to themselves, their siblings and their mothers; their self‐esteem and sense of being ‘different’, their relationships (including ambivalent relationships with their fathers); their experiences of education and their sense of a lost childhood. The final report for the study was based on the total data collection, but this paper will concentrate primarily on the material elicited from the children and young people. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrocarbon‐Soluble Calcium Hydride: A “Worker‐Bee” in Calcium Chemistry
Authors: Spielmann Jan , Harder Sjoerd
Published: October 2007

The reactivity of the hydrocarbon‐soluble calcium hydride complex [{CaH(dipp‐nacnac)(thf)}2] (1; dipp‐nacnac=CH{(CMe)(2,6‐iPr2C6H3N)}2) with a large variety of substrates has been investigated. Addition of 1 to CO and CN functionalities gave easy access to calcium alkoxide and amide complexes. Similarly, reduction of the CN bond in a cyanide or an isocyanide resulted in the first calcium aldimide complexes [Ca{NC(H)R}(dipp‐nacnac)] and [Ca{C(H)NR}(dipp‐nacnac)], respectively. Complexation of 1 with borane or alane Lewis acids gave the borates and alanates as contact ion pairs. In reaction with epoxides, nucleophilic ring‐opening is observed as the major reaction. The high reactivity of hydrocarbon‐soluble 1 with most functional groups contrasts strongly with that of insoluble CaH2, which is essentially inert and is used as a common drying agent. Crystal structures of the following products are presented: [{Ca{OC(H)Ph2}(dipp‐nacnac)}2], [{Ca{NC(H)Ph}(dipp‐nacnac)}2], [{Ca{C(H)NC(Me)2CH2C(Me)3}(dipp‐nacnac)}2], [{Ca{C(H)NCy}(dipp‐nacnac)}2], [Ca(dipp‐nacnac)(thf)]+[H2BC8H14]− and [{Ca(OCy)(dipp‐nacnac)}2]. The generally smooth and clean conversions of 1 with a variety of substrates and the stability of most intermediates against ligand exchange make 1 a valuable key precursor in the syntheses of a wide variety of β‐diketiminate calcium complexes.
Iron–Palladium Association in the Preparation of Indoles and One‐Pot Synthesis of Bis(indolyl)methanes
Authors: Terrasson Vincent , Michaux Julien , Gaucher Anne , Wehbe Johny , Marque Sylvain , Prim Damien , Campagne Jean‐Marc
Published: October 2007

Indoles were prepared by annulation of the parent alkynylanilines with the use of a new FeCl3–PdCl2catalytic combination. High yields were obtained by using low loadings of the transition‐metal complex (FeCl3–PdCl2: 2 and 1 mol‐%, respectively). One‐pot accesses to bis(indolyl)methanes and trisubstituted indoles through annulation/Friedel–Crafts alkylation and annulation/1,4‐Michael addition sequences, in which FeCl3acts both as a cooxidant and a Lewis acid are described.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A review of adverse effects of damping in seismic isolation
Authors: Politopoulos Ioannis
Published: October 2007

In this paper the question of possible adverse effects of damping in seismic isolation because of higher mode response is investigated by means of simple models with a few degrees of freedom (DOF). In particular the second mode response of a 2 DOF system is examined in detail for both viscous and hysteretic (e.g. friction or elastoplastic) damping devices. Qualitative and approximate quantitative estimates are obtained by neglecting the influence of the modal coupling terms, due to viscous damping or friction forces, on the first mode response. It is shown that additional viscous damping has a diminishing effect on base displacement, storey shear force and floor spectra values in the vicinity of the first mode resonance. However, a significant amplification of the floor spectra values near the higher mode frequencies may occur. In accordance with the results of previous works, compared with the viscous damping case, hysteretic damping amplifies moderately the first storey shear force and significantly the upper storeys shear force. It also results, in a much more pronounced amplification of the floor spectral values than viscous damping, in the vicinity of the higher eigenfrequencies. However, the higher modes' response is milder if a realistic velocity dependence of the friction coefficient is taken into account. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of algebraic singularities on the voltage dynamics of differential‐algebraic power system model
Authors: Ayasun Saffet
Published: October 2007

Voltage stability analysis of differential‐algebraic equation (DAE) power system model is more complicated than for systems described by ordinary differential equations (ODEs). In addition to unstable equilibria, algebraic singularity plays a crucial role in assessing the voltage stability. This paper explores the algebraic structure and singularities of the DAE model to investigate its influence on the voltage stability. Singular points are identified at various load levels and are illustrated together with the equilibria using nose curves. Then, at a given load level, the constraint manifold is decomposed into the voltage casual regions and singular points connecting them. Time‐domain simulations initiated in the vicinity of singular points are performed to determine how singular points affect system dynamics. It is shown that depending on the relative location of initial points with respect to singular points, trajectories of bus voltages may settle to an infeasible low voltage stable equilibrium point, which may cause a further disturbance in the system leading a voltage stability problem. Copyright © 2007 John Wiley & Sons, Ltd.
Behavioural and psychological symptoms are not related to white matter hyperintensities and medial temporal lobe atrophy in Alzheimer's disease
Authors: Staekenborg Salka S. , Gillissen Freek , Romkes Rolinka , Pijnenburg Yolande A. L. , Barkhof Frederik , Scheltens Philip , van der Flier Wiesje M.
Published: October 2007

Background

The neuropathology of behavioural and psychological symptoms is much less understood than the neuropathology of cognitive impairment in AD. On MRI, medial temporal lobe atrophy (MTA) is presumed to reflect Alzheimer‐ type pathology. White matter hyperintensities (WMH) are considered markers of vascular pathology.

Aim

We investigated differences in prevalence of behavioural and psychological symptoms in AD according to the presence of MTA and WMH on MRI.

Methods

Behavioural and psychological symptoms of 111 consecutive AD patients were assessed using the Neuropsychatric Inventory (NPI). Symptoms were considered present when the score was ≥1. On MRI, MTA was rated using the five‐point Scheltens‐scale and WMH using the four‐point Fazekas‐scale. Both MRI measures were dichotomised (MTA: absent 0/1, present 2–4; WMH absent 0/1, present 2/3).

Results

Of the 111 AD patients, 60(55%) had MTA, and 32(29%) had WMH. The presence of MTA was associated with the presence of WMH (χ
2 = 11.8, p < 0.001). The prevalence of behavioural and psychological symptoms––defined as a NPI score of ≥1 on at least one symptom––was 74%.The median NPI score of the total study population was 6(0–41). There was no difference in prevalence according to MTA (p = 0.53) or WMH (p = 0.18). On inspection of individual NPI items, neither MTA, nor WMH was related to any of the symptoms.

Conclusions

There were no differences in prevalence of behavioural and psychological symptoms according to MTA or WMH, as rated on MRI. This suggests that the occurrence of those symptoms depends on other determinants, such as coping style or genetic make‐up. Copyright © 2007 John Wiley & Sons, Ltd.
Geoelectrical exploration for groundwater in Al Maha Forest, Ain Jouhra, Morocco
Authors: Toto El Arbi , Kerrouri Chakib , Zouhri Lahcen , Basri Mohamed El , Ibenbrahim Aomar , Mohamad Hafid , Benammi Mohamed
Published: October 2007

An area of about 30 km2 located in Ain Jouhra, south of Rabat, Morocco, was the subject of a geoelectric resistivity investigation. The main goal of the investigation was the assessment of the groundwater potential of the uppermost aquifer. The aquifer conditions such as depth, thickness and boundaries were also investigated. The obtained apparent resistivity curves were first analysed qualitatively and classified using simple curve shapes. Thereafter, the data were converted to resistivity and thickness pairs semi‐quantitatively by means of master curves and then quantitatively by computer modelling using ATO and Winsev software (Zohdy, 1989; Zohdy and Bisdrof, 1989). Lithological control from the available single well with a stratigraphic log aided in the correlation of the resistivity values to different rock units. Three different AB‐spacing iso‐resistivity maps, an isopach map of the main groundwater‐bearing horizon, the depth to the aquifer substratum map and five geoelectric cross‐sections were constructed.

The interpretation of these soundings indicates the presence of an unconfined to semi‐confined sandy aquifer with relatively important extent and varying thickness. The maximal thickness of the aquifer is recorded in the central part of the investigated area and is thinning southwards to pinch out farther to the south. Geophysical as well as field data indicate a hydraulic connection between the upper and deeper aquifers. Indeed, the two aquifers are separated from each other by a marly substratum that is indicated throughout the area by the lowest values of the interpreted true resistivity. The value of this resistivity varies laterally, most likely due to the lateral variation in the shale‐to‐sand ratio. The altitude of the substratum decreases towards the north, and increases southwards.

Regarding the availability of the groundwater in the study area, zones with high potential are theoretically expected to occur in the central part where the transversal resistance is greatest. However, sufficient water supply and high flow rates from wells intended to produce restrictively from the most upper aquifer are not likely to exist. This conclusion, which seems to be very pessimistic, is evidenced from two real field and experimental observations. The first is the rapid fall of the level of Gharnoug lake, despite the ongoing feeding by three wells. Hence, the amount of water level drop cannot be accounted for by the evaporation alone. That means that the deeper aquifer is continuously draining the upper aquifer at a high flow rate. Very low rates are recorded in all the wells that penetrated only the upper aquifer, the exception being the well that reached deeper into the lower aquifer. The flow rate in this lower aquifer measured 18 litre s−1. Copyright © 2007 John Wiley & Sons, Ltd.
Study of indices for drought characterization in KBK districts in Orissa (India)
Authors: Pandey R. P. , Dash B. B. , Mishra S. K. , Singh Ranvir
Published: October 2007

Drought is a temporary, random and regional climatic phenomenon, originating due to lack of precipitation leading to water deficit and causing economic loss. Success in drought alleviation depends on how well droughts are defined and their severity quantified. A quantitative definition identifies the beginning, end, spatial extent and the severity of drought. Among the available indices, no single index is capable of fully describing all the physical characteristics of drought. Therefore, in most cases it is useful and necessary to consider several indices, examine their sensitivity and accuracy, and investigate for correlation among them. In this study, the geographical information system‐based Spatial and Time Series Information Modeling (SPATSIM) and Daily Water Resources Assessment Modeling (DWRAM) software were used for drought analysis on monthly and daily bases respectively and its spatial distribution in both dry and wet years. SPATSIM utilizes standardized precipitation index (SPI), effective drought index (EDI), deciles index and departure from long‐term mean and median; and DWRAM employs only EDI. The analysis of data from the Kalahandi and Nuapada districts of Orissa (India) revealed that (a) droughts in this region occurred with a frequency of once in every 3 to 4 years, (b) droughts occurred in the year when the ratio of annual rainfall to potential evapotranspiration (Pae/PET) was less than 0·6, (c) EDI better represented the droughts in the area than any other index; (d) all SPI, EDI and annual deviation from the mean showed a similar trend of drought severity. The comparison of all indices and results of analysis led to several useful and pragmatic inferences in understanding the drought attributes of the study area. Copyright © 2007 John Wiley & Sons, Ltd.
Factors controlling stable oxygen, hydrogen and carbon isotope ratios in regional groundwater of the eastern United Arab Emirates (UAE)
Authors: Murad Ahmed A. , Krishnamurthy R. V.
Published: October 2007

Increasing groundwater salinity and depletion of the aquifers are major concerns in the UAE. Isotopes of oxygen, hydrogen, and carbon concentrations in groundwater were used to estimate evaporation loss using the isotopes of oxygen and hydrogen, and using a carbon isotope to trace inorganic carbon cycling in two main aquifers in the eastern part of the United Arab Emirates.

The δD‐δ18O of groundwater samples plotted on a line given by: δD = 4 δ18O + 4 ·4 (r2 = 0·4). In comparison, the local meteoric water line (LMWL) has been defined by the line: δD = 8 δ18O + 15. In order to better understand the system investigated, samples were separated into two groups based on the δD‐δ18O relationship. These are (1) samples that plot above the LMWL (δD = 6·1 δ18O + 12·4, r2 = 0·8) and which are located predominantly in the north of the study area, and (2) samples that plot below the LMWL (δD = 5·6 δ18O + 6·2, r2 = 0·8) and which are mostly distributed in the south. Slopes for both the groups are similar and lower than that for LMWL indicating potential evaporation of recharging water. However, the y‐intercept, which differs between the two groups, suggests evaporation of return flow and evapotranspiration in the unsaturated zone to be more significant in the south. This is attributed to intense agricultural activities in the region.

Samples from the eastern Gravel Plain aquifer have δ13C and dissolved inorganic carbon (DIC) values in the range from − 10 to 17‰, and 12–100 mg C/l, respectively, while the range for those from the Ophiolite aquifer is from − 11 to − 16.4‰, and 16–114 mg C/l respectively. This suggests the control of C‐3 and C‐4 plants on DIC formation, an observation supported by the range δ13C of soil organic matter (from − 18·5 to − 22·1‰.) Copyright © 2007 John Wiley & Sons, Ltd.
Control of beta globin genes
Authors: Mahajan Milind C. , Karmakar Subhradip , Weissman Sherman M.
Published: October 2007

The developmental changes in expression of the beta like genes from embryonic to adult stages of human life are controlled at least partially at the level of the promoter sequences of these genes and their binding factors, and competition for promoter specific interactions with the locus control region (LCR). In recent years, the control of beta globin genes has also been investigated at the level of chromatin structure involving the chemical modification of histones and their remodelling by DNA dependent ATPases (SMARCA) containing protein complexes. The role of intergenic RNA is also being investigated with renewed interest. Although a wealth of information on the structure/function relationship of the LCR and globin promoters has been gathered over more than two decades, the fundamental nature of the control of these genes at the molecular level is still not completely understood. In the following pages, we intend to briefly describe the progress made in the field and discuss future directions. J. Cell. Biochem. 102: 801–810, 2007. © 2007 Wiley‐Liss, Inc.
Regulation of C/EBPδ‐dependent transactivation by histone deacetylases in intestinal epithelial cells
Authors: Turgeon Naomie , Valiquette Caroline , Blais Mylène , Routhier Sophie , Seidman Ernest G. , Asselin Claude
Published: October 2007

The C/EBPδ transcription factor is involved in the positive regulation of the intestinal epithelial cell acute phase response. C/EBPδ regulation by histone deacetylases (HDACs) during the course of inflammation remains to be determined. Our aim was to examine the effect of HDACs on C/EBPδ‐dependent regulation of haptoglobin, an acute phase protein induced in intestinal epithelial cells in response to pro‐inflammatory cytokines. HDAC1, HDAC3, and HDAC4 were expressed in intestinal epithelial cells, as determined by Western blot. GST pull‐down assays showed specific HDAC1 interactions with the transcriptional activation and the b‐ZIP C/EBPδ domains, while the co‐repressor mSin3A interacts with the C‐terminal domain. Immunoprecipitation assays confirmed the interaction between HDAC1 and the N‐terminal C/EBPδ amino acid 36–164 domain. HDAC1 overexpression decreased C/EBPδ transcriptional activity of the haptoglobin promoter, as assessed by transient transfection and luciferase assays. Chromatin immunoprecipitation analysis showed a displacement of HDAC1 from the haptoglobin promoter in response to inflammatory stimuli and an increased acetylation of histone H3 and H4. HDAC1 silencing by shRNA expression increased both basal and IL‐1β‐induced haptoglobin mRNA levels in epithelial intestinal cells. Our results suggest that interactions between C/EBPs and HDAC1 negatively regulate C/EBPδ‐dependent haptoglobin expression in intestinal epithelial cells. J. Cell. Biochem. 103: 1573–1583, 2008. © 2007 Wiley‐Liss, Inc.
Immunosuppressive drug‐free operational immune tolerance in human kidney transplant recipients: Part I. blood gene expression statistical analysis
Authors: Braud Christophe , Baeten Dominique , Giral Magali , Pallier Annaïck , Ashton‐Chess Joanna , Braudeau Cecile , Chevalier Catherine , Lebars Alice , Léger Jean , Moreau Anne , Pechkova Eugenia , Nicolini Claudio , Soulillou Jean‐Paul , Brouard Sophie
Published: October 2007

Survival of solid organ grafts depends on life‐long immunosuppression, which results in increased rates of infection and malignancy. Induction of tolerance to allografts would represent the optimal solution for controlling both chronic rejection (CR) and side effects of immunosuppression. Although spontaneous “operational tolerance” can occur in human kidney transplantation, the lack of noninvasive peripheral blood biological markers of this rare phenomenon precludes the identification of potentially tolerant patients in whom immunosuppression could be tapered as well as the development of new tolerance inducing strategies. Here, the potential of high throughput microarray technology to decipher complex pathologies allowed us to study the peripheral blood specific gene expression profile and corresponding EASE molecular pathways associated to operational tolerance in a cohort of human kidney graft recipients. In comparison with patients with CR, tolerant patients displayed a set of 343 differentially expressed genes, mainly immune and defense genes, in their peripheral blood mononuclear cells (PBMC), of which 223 were also different from healthy volunteers. Using the expression pattern of these 343 genes, we were able to classify correctly >80% of the patients in a cross‐validation experiment and classified correctly all of the samples over time. Collectively, this study identifies a unique PBMC gene signature associated with human operational tolerance in kidney transplantation by a classical statistical microarray analysis and, in the second part, by a nonstatistical analysis. J. Cell. Biochem. 103: 1681–1692, 2008. © 2007 Wiley‐Liss, Inc.
Structure and dynamics of phospholipid bilayers using recently developed general all‐atom force fields
Authors: Rosso Lula , Gould Ian R.
Published: October 2007

Two fully hydrated pure‐species phospholipids bilayers, 1,2‐dimyristoyl‐sn‐glycero‐3‐phosphocholine (DMPC) and 1,2‐dioleoyl‐sn‐glycero‐3‐phosphorylcholine (DOPC), in the fluid phase and explicit solvent have been studied using molecular dynamics simulation. Atom interactions were modeled using recently developed force fields based on AMBER with full atomistic details. Several representative liquid phase properties for the structure and dynamics of lipids with different length of hydrocarbon chains and different level of saturation have been reproduced without artificially biasing the system in order to match experimental data. In particular, as the new GAFF (General Amber Force Field) has not been explicitly developed to reproduce lipid characteristics and is naturally compatible with standard AMBER nucleic acids and proteins parameters, it is here proven a promising tool to study mixed lipid–protein processes as protein activity dependence on membrane composition, permeation of solute across membranes, and other cellular processes. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Applications of deuterium isotope effects for probing aspects of reactions involving oxidative addition and reductive elimination of H–H and C–H bonds
Authors: Parkin Gerard
Published: October 2007

The various types of deuterium isotope effects that are observed for reactions involving oxidative addition and reductive elimination reactions of H–H and C–H bonds with a transition metal center are reviewed. Copyright © 2007 John Wiley & Sons, Ltd.
Ligand–receptor interactions and membrane structure investigated by AFM and time‐resolved fluorescence microscopy
Authors: Thormann Esben , Simonsen Adam C. , Nielsen Lars K. , Mouritsen Ole G.
Published: October 2007

The atomic force microscope (AFM) and the associated dynamic force spectroscopy technique have been exploited to quantitatively assess the interaction between proteins and their binding to specific ligands and membrane surfaces. In particular, we have studied the specific interaction between lung surfactant protein D and various carbohydrates. In addition, we have used scanning AFM and time‐resolved fluorescence microscopy to image the lateral structure of different lipid bilayers and their morphological changes as a function of time. The various systems studied illustrate the potential of modern AFM techniques for application to biomedical research, specifically within immunology and liposome‐based drug delivery. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of supercritical carbon dioxide on volatile formation from Maillard reaction between ribose and cysteine
Authors: Xu Honggao , Gao Yanxiang , Liu Xuan , Zhao Jian
Published: October 2007

BACKGROUND: Supercritical carbon dioxide (SC‐CO2) technology is being used in an increasing number of food‐manufacturing applications; however, its effect on the Maillard reaction is not well studied. The objective of this study was to investigate the effect of SC‐CO2 treatment (140 °C, 40 MPa) on the Maillard reaction of an aqueous ribose–cysteine model system under varying pH conditions (5.6, 7.0 and 8.0), with emphasis on the formation of volatile compounds.

RESULTS: SC‐CO2 had a suppressing effect on the browning stages of the reaction under acidic and neutral pH conditions, while it appeared to have an accelerating effect at pH 8.0. Over 70 volatile compounds were positively identified from the headspace of the model system by gas chromatography–mass spectrometry. The volatiles were dominated by sulfur‐containing compounds including thiophenes and fused bicyclic sulfur‐containing compounds under all experimental conditions. Several compounds, including 2‐methyl‐3‐furanthiol, 2‐furanmethanethiol, 3‐thiophenethiol, and 2‐methyl‐3‐thiophenethiol, and one of the intermediates, furfural, were generated in much higher amounts in the SC‐CO2‐treated samples, especially at alkaline and neutral pH values.

CONCLUSION: SC‐CO2 treatment was inhibitory to the formation of most volatiles in the Maillard reaction, but enhanced the formation of some intermediates and well‐known meaty flavoured compounds. Copyright © 2007 Society of Chemical Industry
Fast nosological imaging using canonical correlation analysis of brain data obtained by two‐dimensional turbo spectroscopic imaging
Authors: Laudadio Teresa , Martínez‐Bisbal M. Carmen , Celda Bernardo , Van Huffel Sabine
Published: October 2007

A new fast and accurate tissue typing technique has recently been successfully applied to prostate MR spectroscopic imaging (MRSI) data. This technique is based on canonical correlation analysis (CCA), a statistical method able to simultaneously exploit the spectral and spatial information characterizing the MRSI data. Here, the performance of CCA is further investigated by using brain data obtained by two‐dimensional turbo spectroscopic imaging (2DTSI) from patients affected by glioblastoma. The purpose of this study is to investigate the applicability of CCA when typing tissues of heterogeneous tumors. The performance of CCA is also compared with that of ordinary correlation analysis on simulated as well as in vivo data. The results show that CCA outperforms ordinary correlation analysis in terms of robustness and accuracy. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative ATP synthesis in human liver measured by localized 31P spectroscopy using the magnetization transfer experiment
Authors: Schmid A. I. , Chmelík M. , Szendroedi J. , Krššák M. , Brehm A. , Moser E. , Roden M.
Published: October 2007

The liver plays a central role in intermediate metabolism. Accumulation of liver fat (steatosis) predisposes to various liver diseases. Steatosis and abnormal muscle energy metabolism are found in insulin‐resistant and type‐2 diabetic states. To examine hepatic energy metabolism, we measured hepatocellular lipid content, using proton MRS, and rates of hepatic ATP synthesis in vivo, using the 31P magnetization transfer experiment. A suitable localization scheme was developed and applied to the measurements of longitudinal relaxation times (T1) in six healthy volunteers and the ATP‐synthesis experiment in nine healthy volunteers. Liver 31P spectra were modelled and quantified successfully using a time domain fit and the AMARES (advanced method for accurate, robust and efficient spectral fitting of MRS data with use of prior knowledge) algorithm describing the essential components of the dataset. The measured T1 relaxation times are comparable to values reported previously at lower field strengths. All nine subjects in whom saturation transfer was measured had low hepatocellular lipid content (1.5 ± 0.2% MR signal; mean ± SEM). The exchange rate constant (k) obtained was 0.30 ± 0.02 s−1, and the rate of ATP synthesis was 29.5 ± 1.8 mM/min. The measured rate of ATP synthesis is about three times higher than in human skeletal muscle and human visual cortex, but only about half of that measured in perfused rat liver. In conclusion, 31P MRS at 3 T provides sufficient sensitivity to detect magnetization transfer effects and can therefore be used to assess ATP synthesis in human liver. Copyright © 2007 John Wiley & Sons, Ltd.
Optimal state filtering and parameter identification for linear systems
Authors: Basin Michael , Perez Joel , Skliar Mikhail
Published: October 2007

This paper presents the optimal filtering and parameter identification problem for linear stochastic systems with unknown multiplicative and additive parameters over linear observations, where unknown parameters are considered Wiener processes. The original problem is reduced to the filtering problem for an extended state vector that incorporates parameters as additional states. The obtained optimal filter for the extended state vector also serves as the optimal identifier for the unknown parameters. Performance of the designed optimal state filter and parameter identifier is verified for both stable and unstable linear uncertain systems. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of individual factors in school psychology graduate students: Why do students pursue a degree in school psychology?
Authors: JR. Scott L. Graves , Wright Lynda Brown
Published: October 2007

The purpose of this study was to investigate what factors influenced students to enter the field of school psychology. Although numerous studies have documented the thoughts and perspectives of practitioners regarding why they have chosen to become school psychologists, attempts to recruit and retain an adequate number of school psychology practitioners and researchers have shown limited success. A national sample of 307 school psychology graduate students responded to a survey designed to measure issues related to the current state of professional practice, the influence of parental education, and professional organization recruitment. Results indicated that working with children and personal experiences within the school system were highly related to participant's decisions to become school psychologists. In addition, doctoral level and nondoctoral level students present similar reasons for entering the field. This research is discussed in terms of its implications for future research and the current shortage of school psychology practitioners and faculty. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 865–872, 2007.
An organelle proteomic method to study neurotransmission‐related proteins, applied to a neurodevelopmental model of schizophrenia
Authors: Vercauteren Freya G. G. , Flores Gonzalo , Ma Weiya , Chabot Jean‐Guy , Geenen Lieve , Clerens Stefan , Fazel Ali , Bergeron John J. M. , Srivastava Lalit K. , Arckens Lutgarde , Quirion Rémi
Published: October 2007

Limited information is currently available on molecular events that underlie schizophrenia‐like behaviors in animal models. Accordingly, we developed an organelle proteomic approach enabling the study of neurotransmission‐related proteins in the prefrontal cortex (PFC) of postpubertal (postnatal day 60 (PD60)) neonatally ventral hippocampal (nVH) lesioned rats, an extensively used neurodevelopmental model of schizophrenia‐like behaviors. The PFC was chosen because of its purported role in the etiology of the disease. Statistical analysis of 392 reproducible spots on 2‐D organelle proteomic patterns revealed significant changes in intensity of 18 proteinous spots in plasma membrane‐enriched fractions obtained from postpubertal nVH lesioned rats compared to controls. Mass spectrometric analysis and database searching allowed the identification of a single protein in each of the nine differential spots, including proteins of low abundance, such as neurocalcin δ. Most of the identified dysregulated proteins, including clathrin light chain B, syntaxin binding protein 1b and visinin‐like protein 1 are known to be linked to various neurotransmitter systems and to play key roles in plasma membrane receptor expression and recycling as well as synaptic vesicle exocytosis/recycling. Organelle proteomic approaches have hence proved to be most useful to identify key proteins linked to a given behavior in animal models of brain diseases.
Five years of progress in the Standardization of Proteomics Data 4th Annual Spring Workshop of the HUPO‐Proteomics Standards Initiative April 23–25, 2007 Ecole Nationale Supérieure (ENS), Lyon, France
Authors: Orchard Sandra , Montechi‐Palazzi Luisa , Deutsch Eric W. , Binz Pierre‐Alain , Jones Andrew R. , Paton Norman , Pizarro Angel , Creasy David M. , Wojcik Jérôme , Hermjakob Henning
Published: October 2007

Over the last five years, the Human Proteome Organisation Proteomics Standards Initiative (HUPO PSI) has produced and released community‐accepted XML interchange formats in the fields of mass spectrometry, molecular interactions and gel electrophoresis, have led the field in the discussion of the minimum information with which such data should be annotated and are now in the process of publishing much of this information. At this 4th Spring workshop, the emphasis was on consolidating this effort, refining and improving the existing models and in pushing these forward to align with more broadly encompassing efforts such as FuGE (Jones, A.R., Pizarro, A., Spellman, P., Miller, M., FuGE Working Group FuGE: Functional Genomics Experiment Object Model. OMICS 2006, 10, 179‐184) and the Ontology for Biomedical Investigation (OBI). The effort to merge the existing mass spectrometry XML interchange formats, mzData and mzXML, into one single standard mzML yielded significant progress. Also the preliminary design of AnalysisXML was extended to include several new use cases and better support for quantification information. Finally the Molecular Interaction group discussed the development of a molecular interaction scoring system with accompanying gold standard data test sets.
Ab initiostudy onN,N′,N″‐triaminoguanidine
Authors: Iqbal Pansy , Patel Dhilon S. , Bharatam Prasad V.
Published: October 2007

Electronic structure calculations and second‐order delocalizations inN,N′,N′′‐triaminoguanidine (TAG) have been studied by employingab initioMO and density functional methods. There are total 10 rotational isomers on the potential energy (PE) surface ofTAG. The effect of three amino groups substitution on guanidine (Gu) has been studied in terms of the primary and the secondary electron delocalizations inTAGby employing Natural Population Analysis (NPA). An increased electron delocalization is observed in protonated triaminoguanidine (TAGP) due to the three strong intramolecular hydrogen bonds and hence accounts for its extra stability. The increase in the electron delocalization upon protonation inTAGcan be compared to that in guanidine. The absolute proton affinity (APA) ofTAGis less than that ofGu. HOMA and NICS studies have been carried out to understand electron delocalization inTAGP. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and self‐assembly behavior study of α,ω‐dicarboxyl‐poly(ethylene glycol)–permethyl‐6‐amino‐6‐deoxy‐β‐cyclodextrin‐monoamide: A new β‐cyclodextrin conjugate
Authors: Nagy Miklós , Szőllősi László , Kéki Sándor , Herczegh Pál , Batta Gyula , Jicsinszky László , Zsuga Miklós
Published: October 2007

A new type of amphiphilic macromolecule was synthesized through the attachment of a poly(ethylene glycol) chain to a permethyl‐amino‐β‐cyclodextrin ring. The structure of the product was studied with 1D and 2D NMR experiments and with MALDI‐TOF MS. The resulting comet‐shaped molecule showed self‐assembly behavior in polar solvents. The presence of supramolecular structures in aqueous media was detected with dynamic light scattering and proven also by 2D NOESY and DOSY experiments. The supramolecular structures that formed could serve as starting materials for new types of drug delivery bioconjugates containing two independent dopable sites, that is, the cyclodextrin ring and the core of the supramolecular structure. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5149–5155, 2007
Structural bioinformatics analysis of enzymes involved in the biosynthesis pathway of the hypermodified nucleoside ms2io6A37 in tRNA
Authors: Kaminska Katarzyna H. , Baraniak Urszula , Boniecki Michal , Nowaczyk Katarzyna , Czerwoniec Anna , Bujnicki Janusz M.
Published: October 2007

tRNAs from all organisms contain posttranscriptionally modified nucleosides, which are derived from the four canonical nucleosides. In most tRNAs that read codons beginning with U, adenosine in the position 37 adjacent to the 3′ position of the anticodon is modified to N6‐(Δ2‐isopentenyl) adenosine (i6A). In many bacteria, such as Escherichia coli, this residue is typically hypermodified to N6‐isopentenyl‐2‐thiomethyladenosine (ms2i6A). In a few bacteria, such as Salmonella typhimurium, ms2i6A can be further hydroxylated to N6‐(cis‐4‐hydroxyisopentenyl)‐2‐thiomethyladenosine (ms2io6A). Although the enzymes that introduce the respective modifications (prenyltransferase MiaA, methylthiotransferase MiaB, and hydroxylase MiaE) have been identified, their structures remain unknown and sequence‐function relationships remain obscure. We carried out sequence analysis and structure prediction of MiaA, MiaB, and MiaE, using the protein fold‐recognition approach. Three‐dimensional models of all three proteins were then built using a new modeling protocol designed to overcome uncertainties in the alignments and divergence between the templates. For MiaA and MiaB, the catalytic core was built based on the templates from the P‐loop NTPase and Radical‐SAM superfamilies, respectively. For MiaB, we have also modeled the C‐terminal TRAM domain and the newly predicted N‐terminal flavodoxin‐fold domain. For MiaE, we confidently predict that it shares the three‐dimensional fold with the ferritin‐like four‐helix bundle proteins and that it has a similar active site and mechanism of action to diiron carboxylate enzymes, in particular, methane monooxygenase (E.C.1.14.13.25) that catalyses the biological hydroxylation of alkanes. Our models provide the first structural platform for enzymes involved in the biosynthesis of i6A, ms2i6A, and ms2io6A, explain the data available from the literature and will help to design further experiments and interpret their results. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Biophysical characterization of Vpu from HIV‐1 suggests a channel‐pore dualism
Authors: Mehnert T. , Routh A. , Judge P. J. , Lam Y. H. , Fischer D. , Watts A. , Fischer W. B.
Published: October 2007

Vpu from HIV‐1 is an 81 amino acid type I integral membrane protein which consists of a cytoplasmic and a transmembrane (TM) domain. The TM domain is known to alter membrane permeability for ions and substrates when inserted into artificial membranes. Peptides corresponding to the TM domain of Vpu (Vpu1‐32) and mutant peptides (Vpu1‐32‐W23L, Vpu1‐32‐R31V, Vpu1‐32‐S24L) have been synthesized and reconstituted into artificial lipid bilayers. All peptides show channel activity with a main conductance level of around 20 pS. Vpu1‐32‐W23L has a considerable flickering pattern in the recordings and longer open times than Vpu1‐32. Whilst recordings for Vpu1‐32‐R31V are almost indistinguishable from those of the WT peptide, recordings for Vpu1‐32‐S24L do not exhibit any noticeable channel activity. Recordings of WT peptide and Vpu1‐32‐W23L indicate Michaelis–Menten behavior when the salt concentration is increased. Both peptide channels follow the Eisenman series I, indicative for a weak ion channel with almost pore like characteristics. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Evaluating conformational changes in protein structures binding RNA
Authors: Ellis Jonathan J. , Jones Susan
Published: October 2007

Many protein–RNA recognition events are known to exhibit conformational changes from qualitative observations of individual complexes. However, a quantitative estimation of conformational changes is required if protein–RNA docking and template‐based methods for RNA binding site prediction are to be developed. This study presents the first quantitive evaluation of conformational changes that occur when proteins bind RNA. The analysis of twelve RNA‐binding proteins in the bound and unbound states using error‐scaled difference distance matrices is presented. The binding site residues are mapped to each structure, and the conformational changes that affect these residues are evaluated. Of the twelve proteins four exhibit greater movements in nonbinding site residues, and a further four show the greatest movements in binding site residues. The remaining four proteins display no significant conformational change. When interface residues are found to be in conformationally variable regions of the protein they are typically seen to move less than 2 Å between the bound and unbound conformations. The current data indicate that conformational changes in the binding site residues of RNA binding proteins may not be as significant as previously suggested, but a larger data set is required before wider conclusions may be drawn. The implications of the observed conformational changes for protein function prediction are discussed. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Nanostructuring of Watson–Crick type base‐paired (C60‐uracil):(2‐aminopurine) conjugates in Langmuir films
Authors: Obraztsov I. , Noworyta K. , Kutner W. , Gadde S. , D'Souza F.
Published: October 2007

Langmuir films of an uracil adduct of C60 (C60ur), spread on aqueous subphases of different pH and ionic strength in the presence and absence of 2‐aminopurine (2‐AP), were studied by simultaneous recording of the isotherms of surface pressure and surface potential vs. area per molecule. The film morphology was imaged by Brewster angle microscopy (BAM). C60ur forms “liquid‐expanded” Langmuir films on all studied subphase solutions. The dependence of area per molecule on the initial surface concentration of C60ur indicates substantial aggregation of the adduct molecules in films. Area per molecule for the C60ur film, prepared in the presence of 2‐AP in the subphase solution, is higher than that in its absence indicating that 2‐AP self assemble with C60ur via the Watson–Crick type base‐pairing. Accordingly, the BAM imaged surface of the former film is smoother than that of the latter. Charging of the C60ur film by either protonation or deprotonation of the uracil moiety of the adduct by using either the acidic or basic subphase solution, respectively, leads to formation of less aggregated films. This behavior is manifested by higher values of area per molecule as compared to that determined for the neutral subphase solution. The UV–vis spectra of the C60ur Langmuir‐Blodgett films, transferred from the subphase solutions containing 2‐AP, did not show the absorption band characteristic of 2‐AP as if the (C60ur):(2‐AP) conjugate was ruptured during the transfer. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Periodicity in proton conduction along a H‐bonded chain. Application to biomolecules
Authors: Isaev Alexander , Kar Tapas , Scheiner Steve
Published: October 2007

Molecular complexes are constructed to simulate proton transfer channels of the influenza A virus and of the active site of carbonic anhydrase. These complexes consist of proton donor and acceptor groups connected by a chain of water molecules. Quantum chemical calculations on the methylimidazole(H+)H2OCH3COO− model of the M2 virus channel indicate free translational motion of the water molecule between donor and acceptor, as well as concerted transfer of both H‐bond protons. The proton transfer barrier does not depend on the position of the bridged water molecule and varies linearly with the difference of electrostatic potentials between the donor and acceptor. When the water chain is elongated, and with various donor and acceptor models, periodicity appears in the H‐bond lengths and the progression of proton transfer in each link. This “wave” is shown to propagate along the chain, as it is driven by the displacement of a single proton. One can thereby estimate the velocity of the proton wave and proton conduction time. Computations are performed to examine the influence of immersing the system within a polarizable medium. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008