bluuebunny/crossref_metadata_2025_split huggingface dataset:
Responses of Corcyra cephalonica (Stainton) to pirimiphos‐methyl, spinosad, and combinations of pirimiphos‐methyl and synergized pyrethrins
Authors: Huang Fangneng , Subramanyam Bhadriraju 
Published: January 2004

AbstractField control failures with pirimiphos‐methyl against the rice moth, Corcyra cephalonica (Stainton), in Weslaco, Texas, USA, led us to investigate the susceptibility of this particular strain to pirimiphos‐methyl, spinosad, pyrethrins synergized with piperonyl butoxide, and pirimiphos‐methyl combined with synergized pyrethrins. In laboratory bioassays, 50 eggs of C cephalonica were exposed to untreated and insecticide‐treated corn and sunflower seeds to determine larval survival after 21 days, egg‐to‐adult emergence after 49 days, and larval damage to seeds at both exposure periods. Pirimiphos‐methyl at both 4 and 8 mg kg−1 did not prevent larval survival or egg‐to‐adult emergence of C cephalonica on either corn or sunflower seeds, and seed damage was evident at both rates. The C cephalonica strain was highly susceptible to spinosad at 0.5 and 1 mg kg−1. At both spinosad rates, reduction in larval survival, egg‐to‐adult emergence, and seed damage relative to the control treatment was ≥93% on both corn and sunflower seeds. Pirimiphos‐methyl and spinosad were generally more effective against C cephalonica on corn than sunflower seeds. The C cephalonica strain was completely controlled on corn treated with 1.5 mg kg−1 of pyrethrins synergized with 15 mg kg−1 of piperonyl butoxide. Many larvae survived and became adults on corn treated with synergized pyrethrins at ≤0.75 mg kg−1. Corn treated with pirimiphos‐methyl at 4, 6 or 8 mg kg−1 in combination with 0.38 to 1.5 mg kg−1 of synergized pyrethrins reduced larval survival by ≥95%, egg‐to‐adult emergence by ≥97%, and seed damage by ≥94%. Our results suggest that the C cephalonica strain can be controlled on corn by combining pirimiphos‐methyl with synergized pyrethrins or with synergized pyrethrins at the labeled rate. Although spinosad is not currently labeled for use on stored corn and sunflower seeds, it appears to be effective against C cephalonica on both commodities at very low rates. Copyright © 2004 Society of Chemical Industry
The potential role of arbuscular mycorrhizal (AM) fungi in the bioprotection of plants against soil‐borne pathogens in organic and/or other sustainable farming systems
Authors: Harrier Lucy A , Watson Christine A 
Published: January 2004

AbstractSustainable farming systems strive to minimise the use of synthetic pesticides and to optimise the use of alternative management strategies to control soil‐borne pathogens. Arbuscular mycorrhizal (AM) fungi are ubiquitous in nature and constitute an integral component of terrestrial ecosystems, forming symbiotic associations with plant root systems of over 80% of all terrestrial plant species, including many agronomically important species. AM fungi are particularly important in organic and/or sustainable farming systems that rely on biological processes rather than agrochemicals to control plant diseases. Of particular importance is the bioprotection conferred to plants against many soil‐borne pathogens such as species ofAphanomyces, Cylindrocladium, Fusarium, Macrophomina, Phytophthora, Pythium, Rhizoctonia, Sclerotinium, VerticilliumandThielaviopsisand various nematodes by AM fungal colonisation of the plant root. However, the exact mechanisms by which AM fungal colonisation confers the protective effect are not completely understood, but a greater understanding of these beneficial interactions is necessary for the exploitation of AM fungi within organic and/or sustainable farming systems. In this review, we aim to discuss the potential mechanisms by which AM fungi may contribute to bioprotection against plant soil‐borne pathogens. Bioprotection within AM fungal‐colonised plants is the outcome of complex interactions between plants, pathogens and AM fungi. The use of molecular tools in the study of these multifaceted interactions may aid the optimisation of the bioprotective responses and their utility within sustainable farming systems. Copyright © 2004 Society of Chemical Industry
Approaches to Measure Chemical Similarity – a Review
Authors: Nikolova Nina , Jaworska Joanna 
Published: January 2004

AbstractAlthough the concept of similarity is a convenient for humans, a formal definition of similarity between chemical compounds is needed to enable automatic decision‐making. The objective of similarity measures in toxicology and drug design is to allow assessment of chemical activities. The ideal similarity measure should be relevant to the activity of interest. The relevance could be established by exploiting the knowledge about fundamental chemical and biological processes responsible for the activity. Unfortunately, this knowledge is rarely available and therefore different approximations have been developed based on similarity between structures or descriptor values. Various methods are reviewed, ranging from two‐dimensional, three‐dimensional and field approaches to recent methods based on “Atoms in Molecules” theory. All these methods attempt to describe chemical compounds by a set of numerical values and define some means for comparison between them. The review provides analysis of potential pitfalls of this methodology – loss of information in the representations of molecular structures – the relevance of a particular representation and chosen similarity measure to the activity. A brief review of known methods for descriptor selection is also provided. The popular “neighborhood behavior” principle is criticized, since proximity with respect to descriptors does not necessarily mean proximity with respect to activity. Structural similarity should also be used with care, as it does not always imply similar activity, as shown by examples. We remind that similarity measures and classification techniques based on distances rely on certain data distribution assumptions. If these assumptions are not satisfied for a given dataset, the results could be misleading. A discussion on similarity in descriptor space in the context of applicability domain assessment of QSAR models is also provided. Finally, it is shown that descriptor based similarity analysis is prone to errors if the relationship between the activity and the descriptors has not been previously established. A justification for the usage of a particular similarity measure should be provided for every specific activity by expert knowledge or derived by data modeling techniques.
QSAR analysis of the time dependent hypotensive activity of 1‐[3‐(4‐substituted phenylthio)propyl]‐4‐(3,4‐substituted phenyl)piperazines using Artificial Neural Networks
Authors: Saxena Anil K. , Schaper Klaus‐Jürgen 
Published: January 2004

AbstractThe quantitative analysis and physicochemical description of time‐ and dose‐dependent in vivo drug effects is problematic as observed effects depend on both pharmacodynamics and pharmacokinetics. These factors depend in a different manner on the physicochemical properties of investigated drugs. Obviously in vivo effects of drug series are governed by highly non‐linear and extremely complicated relationships. The exact form of these relations usually can be given only for some restricted experimental conditions and generally may be assumed to be unknown. As the function relating in vivo hypotensive effects of the title compounds observed in cats, to dose, time and physicochemical properties could not be modelled explicitly, an attempt has been made to train an Artificial Neural Network (ANN) to find the unknown non‐linear relationship between input variables and observed % effect values (raw data, ±20–25% error). Although each drug was applied at only two different doses and “% effect” was observed at few time points, the weights characterising the ANN model enabled the calculation/prediction of (i) complete time‐activity profiles (reflecting mainly pharmacokinetics); (ii) physicochemical property dependent activities. Thus, a maximum of information was extracted from raw in vivo data by this approach which may be useful in saving animal experiments in drug development. However, complete dose‐response curves could not be obtained due to insufficient data in terms of applied doses.
Mass spectrometry for the detection of differentially expressed proteins: a comparison of surface‐enhanced laser desorption/ionization and capillary electrophoresis/mass spectrometry
Authors: Neuhoff Nils v. , Kaiser Thorsten , Wittke Stefan , Krebs Ronald , Pitt Andrew , Burchard Aurea , Sundmacher Astrid , Schlegelberger Brigitte , Kolch Walter , Mischak Harald 
Published: January 2004

AbstractThe discovery of biomarkers is currently attracting much interest as it harbors great potential for the diagnosis and monitoring of human diseases. Here we have used two advanced mass spectroscopy based technologies, surface enhanced laser desorption ionization (SELDI‐MS) and capillary electrophoresis/mass spectrometry (CE/MS), to obtain proteomic patterns of urine samples from patients suffering from membranous glomerulonephritis (MGN) and healthy volunteers. The results indicate that CE/MS analysis is able to display a rich and complex pattern of polypeptides with high resolution and high mass accuracy. In order to analyze these patterns, the MosaiqueVisu software was developed for peak identification, deconvolution and the display of refined maps in a three‐dimensional format. The polypeptide profiles obtained with SELDI‐MS from the same samples are much sparser and show lower resolution and mass accuracy. The SELDI‐MS profiles are further heavily dependent on analyte concentration. SELDI‐MS analysis identified three differentially expressed polypeptides, which are potential biomarkers that can distinguish healthy donors from patients with MGN. In contrast, approximately 200 potential biomarkers could be identified by CE/MS. Thus, while SELDI‐MS is easy to use and requires very little sample, CE/MS generates much richer data sets that enable an in‐depth analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Improvements and new capabilities for the multiple Knudsen cell device used in high‐temperature mass spectrometry
Authors: Heyrman M. , Chatillon C. , Collas H. , Chemin J.‐L. 
Published: January 2004

AbstractThe thermodynamic properties of condensed phases, i.e. the activities of components, can be determined from partial pressures measured by the Knudsen cell mass spectrometric method. Improvements in accuracy and yield of this method are obtained with the use of twin cells, an idea proposed in the 1960s. The multiple cell method was perfected in 1977 in our laboratory. Changes to molecular beam sampling and furnace assemblies were required to make the multiple Knudsen cell technique work properly. This paper summarizes these prerequisites, and presents a new device and the associated method of measurements, as well as the necessary tests performed with a silver sample in each cell. Copyright © 2003 John Wiley & Sons, Ltd.
Sensitive sulphur‐specific detection of omeprazole metabolites in rat urine by high‐performance liquid chromatography/inductively coupled plasma mass spectrometry
Authors: Jensen Berit Packert , Smith Christopher , Wilson Ian D. , Weidolf Lars 
Published: January 2004

AbstractThe use of high‐performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS) with sulphur‐specific detection was investigated as a method for obtaining metabolite profiles for the drug omeprazole administered as a 1:1 mixture of 32S‐ and 34S‐labelled material. Analysis based on the monitoring of the chromatographic eluent at either m/z 32 or 34 was not successful due to insufficient sensitivity caused by interferences from polyatomic ions. However, reaction of sulphur with oxygen in the hexapole collision cell, combined with monitoring at m/z 48 (for 32S) or m/z 50 (for 34S), provided a facile method for metabolite profiling. Detection of m/z 48 was superior in sensitivity to detection of m/z 50. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of specific volatile organic compounds synthesised during Tuber borchii fruit body development by solid‐phase microextraction and gas chromatography/mass spectrometry
Authors: Zeppa Sabrina , Gioacchini Anna Maria , Guidi Chiara , Guescini Michele , Pierleoni Raffaella , Zambonelli Alessandra , Stocchi Vilberto 
Published: January 2004

AbstractFruit body development is a particular phase of the Tuber life cycle, characterised by the aggregation of different types of hyphae, i.e., vegetative hyphal cells and highly specialised reproductive hyphae (asci). In order to identify the volatile organic compounds (VOCs) produced in different stages of the Tuber borchii ripening fruit body, solid‐phase microextraction with gas chromatography and mass spectrometry was used. The volatile organic compounds were extracted using a DVB/CAR/PDMS 50/30 μm fiber placed for 10 min at room temperature in the truffle headspace. The results obtained reveal 49 compounds each of which was present only in a particular stage of maturation. 1‐octen‐3‐ol, aromadendrene, α‐farnesene and other terpenoid compounds were of particular interest, and their possible biological roles are discussed. The production of aromadendrene in the completely unripe fruit body suggests the existence of communication events in the early stage of ascomata formation between the fungus and the host plant. α‐Farnesene could represent a chemotactic attractant to saprophytic organisms in order to disperse the fungal spores in the environment. The identification of the VOCs produced by truffles during their maturation could give information about the processes underlying this phase of Tuber life cycle. Copyright © 2003 John Wiley & Sons, Ltd.
Quantitative analysis of triacylglycerol regioisomers in fats and oils using reversed‐phase high‐performance liquid chromatography and atmospheric pressure chemical ionization mass spectrometry
Authors: Fauconnot Laëtitia , Hau Jörg , Aeschlimann Jean‐Marc , Fay Laurent‐Bernard , Dionisi Fabiola 
Published: January 2004

AbstractPositional distribution of fatty acyl chains of triacylglycerols (TGs) in vegetable oils and fats (palm oil, cocoa butter) and animal fats (beef, pork and chicken fats) was examined by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) coupled to atmospheric pressure chemical ionization using a quadrupole mass spectrometer. Quantification of regioisomers was achieved for TGs containing two different fatty acyl chains (palmitic (P), stearic (S), oleic (O), and/or linoleic (L)). For seven pairs of ‘AAB/ABA’‐type TGs, namely PPS/PSP, PPO/POP, SSO/SOS, POO/OPO, SOO/OSO, PPL/PLP and LLS/LSL, calibration curves were established on the basis of the difference in relative abundances of the fragment ions produced by preferred losses of the fatty acid from the 1/3‐position compared to the 2‐position. In practice the positional isomers AAB and ABA yield mass spectra showing a significant difference in relative abundance ratios of the ions AA+ to AB+. Statistical analysis of the validation data obtained from analysis of TG standards and spiked oils showed that, under repeatability conditions, least‐squares regression can be used to establish calibration curves for all pairs. The regression models show linear behavior that allow the determination of the proportion of each regioisomer in an AAB/ABA pair, within a working range from 10 to 1000 μg/mL and a 95% confidence interval of ±3% for three replicates. Copyright © 2003 John Wiley & Sons, Ltd.
Combined effects of environmental factors and regulation on macrophyte vegetation along three rivers in western France
Authors: Bernez Ivan , Daniel Hervé , Haury Jacques , Ferreira Maria Teresa 
Published: January 2004

AbstractThe longitudinal changes of richness and composition of aquatic plants have been studied from headwaters to the fifth stream order in three rivers in western Brittany (France), the Orne, Sélune and Rance. All rivers are regulated by dams along their lower reaches. The total macrophyte richness differed between the rivers (61 to 150 taxa); it was lowest in the Sélune, which flows over a granite substratum throughout its basin. Absolute richness per site varied greatly between rivers, and between groups of sites either upstream or downstream of the dams, though consistently higher values were observed downstream. In contrast, the relative richness at the river basin scale was similar for the group of upstream (average 20 taxa) and downstream sites (average 28) of all rivers. At the site level, richness increased along all there rivers. Several sites below the dams had the highest richness per site, with more than 40 taxa. A shifting evolution of the macrophyte richness was revealed along the river axis, related to habitat heterogeneity and geological changes.Of the 27 abiotic variables initially considered for canonical correspondence analysis, only five to six per river were retained by a forward selection procedure. The eigenvalues of the first two canonical axes explained 16.1 to 22.4% of the total biological variability and 53.9 to 67.7% of the species–environment relationships. The macrophyte distribution was mainly determined by the stream hierarchy, expressed by the distance to source and slope, and showed also the influence of regulation, i.e. the position of the site in relation to the dam. Other physical variables significantly contributed to plant distribution, namely particular habitat types, depth and geological substratum. Nutrient enrichment and organic pollution influences were the main secondary gradients for the Orne and Rance rivers. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of discharge reductions on salt wedge dynamics of the Ebro River
Authors: Sierra J. P. , Sánchez‐Arcilla A. , Figueras P. A. , González Del Río J. , Rassmussen E. K. , Mösso C. 
Published: January 2004

AbstractThe Ebro River is the largest freshwater course of Spain with a discharge (in the lower course) that has been reduced in the last few decades due to the construction of several dams and the corresponding increase of water demand and river regulation. The lowest stretch of this river (about 42 km) behaves most of the time as a highly stratified estuary with a salt wedge. The dynamics of this salt wedge are important from the ecologic and economic points of view and depend mainly on the river discharge, although other factors (like bathymetry and climatology) play a non‐negligible secondary role. The wedge dynamics would also be affected by the planned river diversion scheme towards other areas of Spain. This diversion plan would mean a reduction of about 15% of the annual discharge (in the Ebro lower course) and the corresponding impact should be carefully assessed.With that aim a two‐layer hydrodynamic numerical model has been employed to evaluate the role of flow regulation in the Ebro salt wedge dynamics, with particular emphasis on the potential discharge reduction due to the planned water diversion. The model has been calibrated with data acquired during four field campaigns (one per season) carried out during 1999 and 2000. Different scenarios of discharge reduction have been studied. Model results suggest a significant increase of salt wedge extent and permanence associated with the planned diversion scheme. This would entail an increase of saltwater intrusion problems both for aquifers and crops. Copyright © 2003 John Wiley & Sons, Ltd.
S‐UMTS access network for broadcast and multicast service delivery: the SATIN approach
Authors: Narenthiran K. , Karaliopoulos M. , Evans B. G. , De‐Win W. , Dieudonne M. , Henrio P. , Mazzella M. , Angelou E. , Andrikopoulos I. , Philippopoulos P. I. , Axiotis D. I. , Dimitriou N. , Polydoros A. , Corazza G. E. , Vanelli‐Coralli A. 
Published: January 2004

AbstractThis paper proposes a complete satellite access network solution for multimedia broadcast multicast service (MBMS) delivery based on T‐UMTS standards. First, the benefits of MBMS delivery via satellite (SAT‐MBMS) for both S/T‐UMTS network operators are shown with market and business analysis. A new integrated S/T‐UMTS architecture for MBMS delivery is proposed featuring an intermediate module repeater (IMR) for coverage of urban areas. The architectural options of IMR and terminals are discussed considering the relevant cost and complexity. The IMR propagation channel conditions are investigated and a new propagation channel model is proposed. The potential of advanced coding schemes such as the layered coding technique to tackle the channel variations in broadcast/multicast environment is outlined. The functional and protocol architecture are defined along with the interface between the satellite access network and the UMTS core network. Required modifications on the terrestrial access scheme sub‐layers to support MBMS data are investigated and the relevant logical, transport and physical channels are selected. Based on the channel selection and the point‐to‐multipoint service nature, we define a generic radio resource management (RRM) strategy that takes into account both QoS and GoS requirements. The efficiency of the proposed solutions is evaluated in the presented simulation results, advocating the feasibility of the overall approach. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating life expectancy and related probabilities in screen‐detected breast cancer patients with restricted follow‐up information
Authors: Straatman Huub , Verbeek André L. M. , Peer Petronella G. M. , Borm George 
Published: January 2004

AbstractIssues such as life expectancy after diagnosis, the number of life years gained by early diagnosis through screening, the probability of dying from breast cancer or of dying from other causes during the lead time period or thereafter can be derived from information on complete survival after diagnosis. A method is presented to estimate complete survival and relevant outcomes after diagnosis of screen‐detected cancer when the follow‐up period is substantially shorter than the maximum follow‐up possible. Survival after diagnosis until death from breast cancer is modelled as the sum of the lead time (LT) and the post‐lead time (PLT), where both time periods follow exponential distributions and are assumed to be independent. The survival period after diagnosis until death from causes other than breast cancer (X) is assumed to follow a Gompertz distribution. The survival period after diagnosis until death from any cause (Z) is modelled as the minimum of LT+PLT and X. Maximum likelihood methods were then used to estimate all parameters of Z. This procedure for obtaining maximum likelihood estimates of Z does not need the cause of death (breast cancer or other), which is an advantage over most other methods. Especially in older patients, it may be difficult or even impossible to ascertain the true cause of death. The model was applied to data from the long‐term breast cancer screening programme in Nijmegen, the Netherlands. Complete survival was estimated on the basis of survival data on 528 screen‐detected breast cancer patients, diagnosed in 1975–1997 and with a mean follow‐up of 8.9 years. Estimated life expectancy ranged between 22.3 and 9.0 years for patients diagnosed at the age of 50 and 79 years, respectively, that is, 6.1 and 0.7 life years gained by screening. Through early diagnosis and treatment, screen‐detected patients diagnosed at the age of 50 years may have reduced their lifetime risk of dying from breast cancer from 79 per cent to 56 per cent; at the age of 79 the reduction of risk is reduced from 23 per cent to 13 per cent. Copyright © 2004 John Wiley & Sons, Ltd.