bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic analysis of aneuploid lines in the homeologous group 1 of the hexaploid wheat cultivar Courtot
Authors: Dumur Jérôme , Jahier Joseph , Bancel Emmanuelle , Laurière Michel , Bernard Michel , Branlard Gérard 
Published: July 2004

AbstractThree monosomic lines (MSLs) and three nullisomic lines (NSLs) of the homeologous group 1 and one euploid line of the bread wheat Triticum aestivum cultivar Courtot were used in a proteomic approach to investigate the effects of zero, one or two doses of chromosomes 1A, 1B and 1D on the amount of endosperm proteins. Polypeptides whose amounts changed significantly between each aneuploid line and the euploid line were identified using image analyses of two‐dimensional gel electrophoresis patterns resulting from specific endosperm protein extractions. Matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry and electrospray ionization tandem mass spectrometry were also used for protein identification. Removing one chromosome or a chromosome pair allowed varying responses to be observed for the remaining endosperm protein genes. Compensation phenomena for the high molecular weight glutenin subunits (HMW‐GS) were detected only in the MSLs. Subunits Bx7, By8 and Dy12 were the only HMW‐GS overexpressed (from 152–737%) when chromosomes 1A or 1B or 1D were at hemizygous state. Thirteen new protein spots were detected only in the NSL1D, and seven were identified as HMW‐GS analogs. These seven new spots may result from the expression of inactive genes. The HMW‐GS were of significantly higher volume in MSLs, whereas the low molecular weight glutenin subunits and the γ‐gliadins were of lower volume in aneuploid lines. Most of the down‐regulated proteins in the MSLs were storage proteins encoded at loci located on another chromosome pair. Complex regulations between chromosomes and loci of the homeologous groups 1 and 6 in bread wheat are discussed.
High resolution mass spectrometric alveolar proteomics: Identification of surfactant protein SP‐A and SP‐D modifications in proteinosis and cystic fibrosis patients
Authors: Bai Yu , Galetskiy Dmitry , Damoc Eugen , Paschen Christian , Liu Zhiqiang , Griese Mathias , Liu Shuying , Przybylski Michael 
Published: July 2004

AbstractIn the present study, one‐ and two‐dimensional gel electrophoresis combined with high resolution Fourier transform‐ion cyclotron resonance mass spectrometry (FT‐ICR MS) have been applied as powerful approaches for the proteome analysis of surfactant proteins SP‐A and SP‐D, including identification of structurally modified and truncation forms, in bronchoalveolar lavage fluid from patients with cystic fibrosis, chronic bronchitis and pulmonary alveolar proteinosis. Highly sensitive micropreparation techniques were developed for matrix‐assisted laser desorption/ionization (MALDI) FT‐ICR MS analysis which provided the identification of surfactant proteins at very low levels. Owing to the high resolution, FT‐ICR MS was found to provide substantial advantages for the structural identification of surfactant proteins from complex biological matrices with high mass determination accuracy. Several protein bands corresponding to SP‐A and SP‐D were identified by MALDI‐FT‐ICR MS after electrophoretic separation by one‐ and two‐dimensional gel electrophoresis, and provided the identification of structural modifications (hydroxy‐proline) and degradation products. The high resolution mass spectrometric proteome analysis should facilitate the unequivocal identification of subunits, aggregations, modifications and degradation products of surfactant proteins and hence contribute to the understanding of the mechanistic basis of lung disease pathogenesis.
The influence of interlayer cations on the photo‐oxidative degradation of polyethylene/montmorillonite composites
Authors: Qin Huaili , Zhang Zhenguang , Feng Meng , Gong Fangling , Zhang Shimin , Yang Mingshu 
Published: July 2004

AbstractThe photo‐oxidative degradation of polyethylene/montmorillonite (PE/MMT) nanocomposite and microcomposite has been investigated. It has been found that the rate of photo‐oxidative degradation of PE/MMT nanocomposite and PE/Mn+MMT (where Mn+ stands for multivalent transition metal cation) microcomposites is much faster than that of pure PE. For the PE/MMT nanocomposite, the acceleration of photo‐oxidative degradation is due to the influence of MMT and ammonium ion, in which the influence of ammonium is primary. The decomposition of ammonium ion may create acidic sites on layered silicates; meanwhile, the complex crystallographic structure and habit of clay minerals could also result in some active sites. The reversible photo‐redox reaction of transition metal cations has a catalytic effect in the degradation of the polymer matrix. All these catalytic active sites can accept single electrons from donor molecules of polymer matrix and induce the formation of free radical upon UV irradiation. The generation of free radical leads to the oxidization and break of molecular chain. Thus, the materials suffer degradation and their mechanical strength decreases. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3006–3012, 2004
Arthropod defensins illuminate the divergence of scorpion neurotoxins
Authors: Froy Oren , Gurevitz Michael 
Published: July 2004

AbstractDefensins are phylogenetically ancient antibacterial polypeptides found in plants and animals. Isolation of the cDNA and genomic sequences encoding the scorpion (Leiurus quinquestriatus hebraeus) defensin revealed similarity to scorpion neurotoxins in gene organization (two exons and a phase I intron) and intron characteristics (conserved acceptor, donor and putative branch sites). This commonality, alongside a similar core structure, protein sequence and bioactivity suggest that arthropod defensins and scorpion neurotoxins share a common ancestor. Interestingly, phylogenetic analysis of defensins and scorpion neurotoxins illuminates for the first time a putative evolutionary trajectory for scorpion sodium and potassium channel neurotoxins. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Autonomous ground vehicle path tracking
Authors: Wit Jeff , Crane Carl D. , Armstrong David 
Published: July 2004

AbstractAutonomous ground vehicle navigation requires the integration of many technologies such as path planning, position and orientation sensing, vehicle control, and obstacle avoidance. The work presented here focuses on the control of a nonholonomic ground vehicle as it tracks a given path. A new path tracking technique called “vector pursuit” is presented. This new technique is based on the theory of screws, which was developed by Sir Robert Ball in 1900. It generates a desired vehicle turning radius based on the vehicle's current position and orientation relative to the position of a point ahead on the planned path and the desired orientation along the path at that point. The vector pursuit algorithm is compared to other geometrical approaches, and it is shown to be more robust, resulting in more accurate path tracking. © 2004 Wiley Periodicals, Inc.
Macroinvertebrate assemblages in streams of interior Alaska following alluvial gold mining
Authors: Milner A. M. , Piorkowski R. J. 
Published: July 2004

AbstractAlluvial gold mining, or placer mining, represents a major disturbance to stream ecosystems in interior Alaska. This process typically involves re‐routing the stream to one side of the valley while the gravels are removed across the floodplain for processing. The stream is then re‐directed back into a reclaimed new channel after mining has ceased in that section of stream. Macroinvertebrate colonization of reclaimed stream reaches is necessary for benthic community recovery following mining. Macroinvertebrate community assemblages at 36 sites on six streams in interior Alaska were examined. Sites with different mining histories were compared to control sites. TWINSPAN classification and ordination of sites using macroinvertebrate abundance indicated a greater similarity of sites within watersheds than between watersheds even though each watershed had a history of mining including recently mined sites. Significant differences were found for total invertebrate abundance, percentage dominant taxon and mean total biomass of macroinvertebrates between control sites and sites that were recently mined (≤10 years) and sites mined 12–50 years ago. Total macroinvertebrate abundance and biomass was lower and taxon dominance higher in both groups of sites with a history of mining. No significant difference in these or other measures was found for sites where mining occurred upstream. There was also no significant relationship between time since mining and the biotic measures used to summarize macroinvertebrate community structure. Although taxon richness recovered rapidly, no individual taxon was found to be a specific indicator of macroinvertebrate recovery since mining. Copyright © 2004 John Wiley & Sons, Ltd.
Spatial variation in fine sediment transport in small upland streams: the effects of flow regulation and catchment geology
Authors: Bond Nicholas R. 
Published: July 2004

AbstractIn cobble‐ and gravel‐bed streams, fine sediments (<4 mm diameter) are an important component of the bed material that can move at a full range of flows, not just during floods and spates. It has been hypothesized that the constant movement of this fine material, as it passes over the coarse bed, is an important ecological disturbance to plants and animals. In this study, I measured baseflow sediment transport rates across a number of regulated and unregulated sites in an upland catchment comprising isolated regions of granite/sandstone and acid volcanics in southern Victoria, southeastern Australia, as a precursor to a study examining the effects of sediment on aquatic biota. Examined on three separate occasions, transport rates for fine sediments were up to 100 times greater in the granite/sandstone streams, but diversion weirs, which greatly reduced downstream sediment loads in the granite/sandstone areas, moderated these differences. Measured transport rates within unregulated sections of the granite/sandstone streams were roughly equivalent to sediment loads found to disturb benthic communities in other experimental studies. On this basis, abrasion by sediment transport in these streams may be sufficient to influence the structure of benthic communities even at baseflow. This hypothesis forms the basis of other research examining the biota at these sites. Copyright © 2004 John Wiley & Sons, Ltd.
Green hydropower: a new assessment procedure for river management
Authors: Bratrich Christine , Truffer Bernhard , Jorde Klaus , Markard Jochen , Meier Werner , Peter Armin , Schneider Matthias , Wehrli Bernhard 
Published: July 2004

AbstractHydropower is the most important renewable electricity source worldwide. It shows clear advantages for the global CO2 balance but creates serious ecological impacts on a local scale. As a consequence, concern for the conservation of natural river ecosystems is growing within society and more people are willing to pay extra for so‐called ‘green electricity’. The definition of ‘green’, however, is not straightforward and customers cannot directly examine the quality of electricity products. Therefore, credible certification of high ecological standards is essential for successful green electricity marketing.In this paper we introduce a new assessment procedure for evaluating environmentally compatible hydropower production. This so‐called ‘Green Hydro’ concept was developed in the context of a multidisciplinary case study on a 400 MW hydropower scheme in the Southern Alps of Switzerland. The concept guarantees both general standards for different schemes operating in different types of watersheds and flexibility for local particularities. We developed an environmental management matrix that considers basic criteria and eco‐investments and covers five environmental areas of concern (i.e. hydrological character, connectivity, morphology, landscape, and biological communities). The ecological perspective is complemented by five management domains (i.e. instream flow regimes, hydropeaking, reservoir and bedload management, and power plant structures). Applying assessment and modelling tools for the Green Hydro procedure showed that dynamic habitat models allowed quantification of the effects of different instream flow regulations at morphologically distinct sites. In this case, morphological restoration could be more beneficial than increasing the minimum flow.The first experience with the Green Hydro certification is encouraging. So far, 13 facilities have successfully passed the certification procedure. They produce a total of 186 GWh green electricity per year, which is sufficient for the supply of almost 40 000 households in Switzerland. Copyright © 2004 John Wiley & Sons, Ltd.
The TGFβ inducible early gene plays a central role in the anti‐proliferative response to TGFβ
Authors: Johnsen Steven A. , Subramaniam Malayannan , Effenberger Katharina E. , Spelsberg Thomas C. 
Published: July 2004

AbstractSignaling through the Transforming Growth Factor‐β (TGFβ)/Smad pathway plays an important role in a variety of cellular processes including the control of cellular proliferation and oncogenesis. The TGFβ Inducible Early Gene (TIEG) is a primary response gene for TGFβ which controls the activity of the Smad pathway. In addition, studies from our laboratory have demonstrated that TIEG expression is lost during the progression of breast cancer. In the present study we utilized a tetracycline inducible TIEG overexpressing breast cancer cell line and TIEG null mouse embryo fibroblasts (MEFs) to establish whether TIEG plays a central role in eliciting the anti‐proliferative effects of TGFβ. We demonstrate that, similar to TGFβ treatment, TIEG overexpression significantly decreases cellular proliferation. Consistent with a role in regulating cellular proliferation, TIEG overexpression increases the expression of the cyclin dependent kinase inhibitor p21. Interestingly, while cellular proliferation of wild‐type MEFs is inhibited by TGFβ, proliferation of TIEG null MEFs is stimulated by TGFβ. Furthermore, TIEG null MEF cells display a decrease in Smad dependent transcription with a concomitant prolonged increase in Smad7 expression compared to wild‐type cells. These data strongly suggest that TIEG plays a central role in the anti‐proliferative response to TGFβ and may explain how a loss of TIEG expression contributes to the development of cancer.
Estimation of the circulation distribution on a rotor blade from detailed near wake velocities
Authors: Mast E. H. M. , Vermeer L. J. , van Bussel G. J. W. 
Published: July 2004

AbstractThe circulation distribution over a blade of a wind turbine model is estimated by use of a vortex model, which is matched with measured wake properties. With near wake velocities and the Biot–Savart law an optimization scheme is constructed to estimate the circulation distribution over the blade using a polynomial function series to approximate the circulation distribution. The velocities resulting from the calculated distribution are compared with the measured data, and deviations are discussed and explained. The vortex model offers insight into how the measured velocities can be separated into induced velocities of the different parts of the vortex system, such as the influence of the tip vortex. The sensitivity of the vortex model to its most uncertain parameters is tested. Finally the circulation distribution obtained with the vortex model is compared with the circulation distribution obtained through application of a blade element momentum (BEM) code. The BEM results show an underestimation of the circulation near the root and an overestimation of the circulation near the tip with respect to the vortex model results. Copyright © 2004 John Wiley & Sons, Ltd.
Composition, components and sources of fine aerosol fractions using multielemental EDXRF analysis
Authors: Marcazzan G. M. , Ceriani M. , Valli G. , Vecchi R. 
Published: July 2004

AbstractThe extensive characterization of the elemental composition of some important components and of major sources of particulate matter PM10 and PM2.5, sampled in parallel three times per week in Milan, for the whole year 2001 is described. More than 250 PM samples were analysed and major, minor and trace element concentrations were obtained by EDXRF. A strong seasonal modulation of particulate matter and element concentrations and an important contribution to PM from secondary compounds originating from gaseous precursors were observed. The main sources and their contribution were obtained by the application of absolute principal factor analysis to the large data set of elemental concentration. Copyright © 2004 John Wiley & Sons, Ltd.
Routine x‐ray fluorescence analysis of powder materials using the ‘VERBA‐XRF’ mode
Authors: Verkhovodov Petro O. 
Published: July 2004

AbstractA new version of the ‘VERBA‐XRF’ mode was developed for the determination of the contents of principal elements with atomic numbers Z > 10 and SUM9, that is, the sum of the contents of complementary elements with Z < 9 in powder materials without alloying with borax. An original set of equations provides determination of the SUM9. Analysis was made on 120 samples: dust from electric filters, clay, clinker, gypsum, bauxite, slag, candle‐end, shale, schlamm and chalk. The results obtained in the determination of the elements Fe, Ti, Ca, K, S, Si, Al and Mg have relative standard errors of 1–2%. The availability of the value of the SUM9 provided the possibility of determining chemical compositions in samples. The content of mineral white in natural gypsum was calculated. Copyright © 2004 John Wiley & Sons, Ltd.
Index reduction for differential‐algebraic equations by minimal extension
Authors: Kunkel P. , Mehrmann V. 
Published: July 2004

AbstractIn this paper a new index reduction technique is discussed for the treatment of differential‐algebraic systems for which extra structural information is available. Based on this information reduced derivative arrays are formed and instead of using expensive subspace computations the index reduction is obtained by introducing new variables. The new approach is demonstrated for several important classes of differential‐algebraic systems, where the structural information is available. These include multibody systems and circuit simulation problems. The effectiveness of the new approach is demonstrated via numerical examples.
On some mathematical modelling of self‐field MPD thrusters
Authors: Coclici C.A. , Heiermann J. , Moroşanu G. , Wendland W.L. 
Published: July 2004

AbstractWe are concerned with the mathematical modelling of high‐enthalpy compressible plasma flows of magnetoplasmadynamic (MPD) rocket thrusters. A closed system of partial differential equations is associated with corresponding two‐fluid flows which are subjected to strong electromagnetic fields. The numerical solution of the full original model requires nowadays huge computational costs. Therefore we use a heterogeneous domain decomposition where the corresponding coupled model is based on simplified conservation laws in a large subdomain. We establish new transmission conditions for the coupled MPD model, which appear as a byproduct of a detailed asymptotic analysis of the artificial interfaces that arise by domain decomposition. Moreover, a complete coupled mathematical MPD model is formulated, including appropriate outer boundary conditions. The well‐posedness of this model is discussed by using mathematical as well as physical arguments.
A note on the flow equations under space‐time transformation
Authors: Wu Z.‐N. 
Published: July 2004

AbstractThe equations governing incompressible and compressible inviscid flows and written in the physical frame (t,x,y,z) are known to be linearly well‐posed and exhibit elliptic or hyperbolic nature. The linear well‐posedness is considered here for these equations under a space‐time transformation (t,x,y,z) → (τ,ξ,η,ς), where the pseudo‐time τ and the new space coordinate (ξ,η,ς) all depend on (t,x,y,z). This type of transformation is typical in Computational Fluid Dynamics when local time‐stepping is used and it could be useful for uniformly treating problems such as mixed fast‐slow unsteady flows in which the flow is fast unsteady somewhere and slowly unsteady or steady elsewhere and mixed incompressible‐compressible flows. It is found that the transformation may alter the ellipticity, the hyperbolicity, and even the well‐posedness of the original equations.
Risk of breast cancer with estrogen‐progestin replacement therapy
Authors:   Committee on Gynecologic Practice
Published: July 2004

AbstractRecent articles have examined the association between the use of combination estrogen‐progestin regimens for hormone replacement therapy (HRT) and the risk of breast cancer. The objective of this Committee Opinion is to evaluate critically the presented evidence. Although epidemiologic studies suggest that the addition of progestins to estrogens may increase the risk of breast cancer, this increased risk has not been proved. The American College of Obstetricians and Gynecologists continues to recommend that HRT be considered as a treatment to relieve vasomotor symptoms and genitourinary tract atrophy and to reduce the risk of osteoporosis and, potentially, cardiovascular disease. Postmenopausal women should be apprised of the current understanding of the risks and benefits of HRT. When considering the use of HRT for longer than 5 years, the clinician and individual patient should weigh the benefits versus the potential side effects and risks for that particular patient.
Von Willebrand's disease in gynecologic practice
Authors: Committee on Gynecologic Practice  
Published: July 2004

AbstractVon Willebrand's disease is one of the most common inherited bleeding disorders. Inherited and acquired disorders of coagulation and hemostasis should be considered in the differential diagnosis of menorrhagia and abnormal uterine bleeding. This Committee Opinion provides screening recommendations for von Willebrand's disease and describes treatment options.
Flexibility in the P2 domain of the HIV‐1 Gag polyprotein
Authors: Newman John L. , Butcher Eric W. , Patel Dipti T. , Mikhaylenko Yelena , Summers Michael F. 
Published: July 2004

AbstractThe HIV‐1 Gag polyprotein contains a segment called p2, located between the capsid (CA) and nucleocapsid (NC) domains, that is essential for ordered virus assembly and infectivity. We subcloned, overexpressed, and purified a 156‐residue polypeptide that contains the C‐terminal capsid subdomain (CACTD) through the NC domain of Gag (CACTD‐p2‐NC, Gag residues 276–431) for NMR relaxation and sedimentation equilibrium (SE) studies. The CACTD and NC domains are folded as expected, but residues of the p2 segment, and the adjoining thirteen C‐terminal residues of CACTD and thirteen N‐terminal residues of NC, are flexible. Backbone NMR chemical shifts of these 40 residues deviate slightly from random coil values and indicate a small propensity toward an α‐helical conformation. The presence of a transient coil‐to‐helix equilibrium may explain the unusual and necessarily slow proteolysis rate of the CA‐p2 junction. CACTD‐p2‐NC forms dimers and self‐associates with an equilibrium constant (Kd = 1.78 ± 0.5 μM) similar to that observed for the intact capsid protein (Kd = 2.94 ± 0.8 μM), suggesting that Gag self‐association is not significantly influence by the P2 domain.