bluuebunny/crossref_metadata_2025_split huggingface dataset:
Titanium‐mediated living radical styrene polymerizations. VI. Cp2TiCl‐catalyzed initiation by epoxide radical ring opening: Effect of the reducing agents, temperature, and titanium/epoxide and titanium/zinc ratios
Authors: Asandei Alexandru D. , Moran Isaac W. , Saha Gobinda , Chen Yanhui 
Published: February 2006

AbstractThe effects of the reducing agent, temperature, and epoxide/Ti and Ti/Zn ratios were investigated for the Cp2TiCl‐catalyzed living radical polymerization of styrene initiated by epoxide radical ring opening. No reduction of bis(cyclopentadienyl)titanium dichloride occurred with Cu, Devarda's alloy, Ni, Ce, Cr, Sn, Mo, and ascorbic acid, whereas Al, lithium nitride, Mn, Sm, and Fe led to free‐radical or poorly controlled polymerizations. The best results were obtained with Zn alloy, powder, or nanoparticles. Nano‐Zn provided the lowest polydispersity index values, highest initiator efficiency (IE), and fastest reaction rate while maintaining a well‐defined living polymerization. Progressively lower polydispersity was obtained with an increasing excess of Zn with an optimum at Cp2TiCl/Zn = 1/2. This was rationalized through the heterogeneous nature of Zn and its possible involvement in the reversible termination step. The polymerization was insensitive to light or dark conditions, and a linear dependence of Mn on the conversion was observed at all temperatures in the 60–130 °C range with an optimum at 70–90 °C. A stoichiometric 1/2 epoxide/Ti ratio provided low polydispersity (weight‐average molecular weight/number‐average molecular weight < 1.2) and high IE, whereas increasing the epoxide/Ti ratio to 1/3 maintained a low polydispersity index but decreased the IE. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2156–2165, 2006
Lung inflammation in preterm infants with respiratory distress syndrome: Effects of ventilation with different tidal volumes
Authors: Lista Gianluca , Castoldi Francesca , Fontana Paola , Reali Roberta , Reggiani Alessandro , Bianchi Silvia , Compagnoni Gilberto 
Published: February 2006

AbstractVentilation with an inappropriate tidal volume (Vt) triggers lung inflammation, an important predisposing factor of bronchopulmonary dysplasia. It still remains uncertain what the appropriate starting target Vt should be during the acute phase of respiratory distress syndrome (RDS). Our aim was to evaluate lung inflammation in preterm infants undergoing synchronized intermittent positive‐pressure ventilation (SIPPV) with two different tidal volumes Vt during the acute phase of RDS. Thirty preterm infants (gestational age, 25–32 weeks) with acute RDS were randomly assigned to be ventilated with Vt = 5ml/kg (n = 15) or Vt = 3 ml/kg (n = 15). Proinflammatory cytokines (interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), and tumor necrosis factor (TNF)‐α) were determined in the tracheal aspirate on days 1, 3, and 7 of life. IL‐8 and TNF‐α levels collected on day 7 were significantly higher (P < 0.05), and mechanical ventilation lasted longer in the group with Vt = 3 ml/kg (16.8 ± 4 vs. 9.2 ± 4 days; P = 0.05). In conclusion, our data show significantly higher lung inflammation in preterm infants ventilated with Vt = 3 ml/kg, suggesting a role for Vt = 5 ml/kg in reducing both inflammatory response during the acute phase of RDS and the length of ventilation. Whether the use of this starting Vt prevents bronchopulmonary dysplasia requires further study. Pediatr Pulmonol. © 2006 Wiley‐Liss, Inc.
Empirical potential function for simplified protein models: Combining contact and local sequence–structure descriptors
Authors: Zhang Jinfeng , Chen Rong , Liang Jie 
Published: February 2006

AbstractAn effective potential function is critical for protein structure prediction and folding simulation. Simplified protein models such as those requiring only Cα or backbone atoms are attractive because they enable efficient search of the conformational space. We show residue‐specific reduced discrete‐state models can represent the backbone conformations of proteins with small RMSD values. However, no potential functions exist that are designed for such simplified protein models. In this study, we develop optimal potential functions by combining contact interaction descriptors and local sequence–structure descriptors. The form of the potential function is a weighted linear sum of all descriptors, and the optimal weight coefficients are obtained through optimization using both native and decoy structures. The performance of the potential function in a test of discriminating native protein structures from decoys is evaluated using several benchmark decoy sets. Our potential function requiring only backbone atoms or Cα atoms have comparable or better performance than several residue‐based potential functions that require additional coordinates of side‐chain centers or coordinates of all side‐chain atoms. By reducing the residue alphabets down to size 10 for contact descriptors, the performance of the potential function can be further improved. Our results also suggest that local sequence–structure correlation may play important role in reducing the entropic cost of protein folding. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Evolutionary coupling of structural and functional sequence information in the intracellular lipid‐binding protein family
Authors: Marcelino Anna Marie C. , Smock Robert G. , Gierasch Lila M. 
Published: February 2006

AbstractWe have mined the evolutionary record for the large family of intracellular lipid‐binding proteins (iLBPs) by calculating the statistical coupling of residue variations in a multiple sequence alignment using methods developed by Ranganathan and coworkers (Lockless and Ranganathan, Science 1999:286;295–299). The 213 sequences analyzed have a wide range of ligand‐binding functions as well as highly divergent phylogenetic origins, assuring broad sampling of sequence space. Emerging from this analysis were two major clusters of coupled residues, which when mapped onto the structure of a representative iLBP under study in our laboratory, cellular retinoic‐acid binding protein I, are largely contiguous and provide useful points of comparison to available data for the folding of this protein. One cluster comprises a predominantly hydrophobic core away from the ligand‐binding site and likely represents key structural information for the iLBP fold. The other cluster includes the portal region where ligand enters its binding site, regions of the ligand‐binding cavity, and the region where the 10‐stranded β‐barrel characteristic of this family closes (between strands 1′ and 10). Linkages between these two clusters suggest that evolutionary pressures on this family constrain structural and functional sequence information in an interdependent fashion. The necessity of the structure to wrap around a hydrophobic ligand confounds the typical sequestration of hydrophobic side chains. Additionally, ligand entry and exit require these structures to have a capacity for specific conformational change during binding and release. We conclude that an essential and structurally apparent separation of local and global sequence information is conserved throughout the iLBP family. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Amino acid sequence predicts folding rate for middle‐size two‐state proteins
Authors: Huang Ji‐Tao , Tian Jing 
Published: February 2006

AbstractThe significant correlation between protein folding rates and the sequence‐predicted secondary structure suggests that folding rates are largely determined by the amino acid sequence. Here, we present a method for predicting the folding rates of proteins from sequences using the intrinsic properties of amino acids, which does not require any information on secondary structure prediction and structural topology. The contribution of residue to the folding rate is expressed by the residue's Ω value. For a given residue, its Ω depends on the amino acid properties (amino acid rigidity and dislike of amino acid for secondary structures). Our investigation achieves 82% correlation with folding rates determined experimentally for simple, two‐state proteins studied until the present, suggesting that the amino acid sequence of a protein is an important determinant of the protein‐folding rate and mechanism. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Upper susceptibility threshold limits with confidence intervals: a method to identify normal and abnormal population values for laboratory toxicological parameters, based on acetylcholinesterase activities in sea lice
Authors: Fallang Anders , Larsen Stig , Horsberg Tor E 
Published: February 2006

AbstractThe interpretation and importance of comparing field values of susceptibility to pesticides with a laboratory reference strain that might bear little resemblance to the actual situation in the field are problematic and a continuing subject of debate. In this paper a procedure for defining a ‘normal sensitive’ population from a field study of 383 individuals to provide a basis for analysing and interpreting in vitro results is described and examined. Instead of using only the 95th percentile, the upper and lower confidence limits for the 95th percentile were also compared to select the best estimation of the limit for the normal material. A field population constrained by the upper confidence limit for the 95th percentile provides appropriate descriptions of the normal material in this study. This approach should prove useful in studies of pesticide resistance in field populations. Copyright © 2006 Society of Chemical Industry
Impact of fungal drug transporters on fungicide sensitivity, multidrug resistance and virulence
Authors: de Waard Maarten A , Andrade Alan C , Hayashi Keisuke , Schoonbeek Henk‐jan , Stergiopoulos Ioannis , Zwiers Lute‐Harm 
Published: February 2006

AbstractDrug transporters are membrane proteins that provide protection for organisms against natural toxic products and fungicides. In plant pathogens, drug transporters function in baseline sensitivity to fungicides, multidrug resistance (MDR) and virulence on host plants. This paper describes drug transporters of the filamentous fungi Aspergillus nidulans (Eidam) Winter, Botrytis cinerea Pers and Mycosphaerella graminicola (Fückel) Schroter that function in fungicide sensitivity and resistance. The fungi possess ATP‐binding cassette (ABC) drug transporters that mediate MDR to fungicides in laboratory mutants. Similar mutants are not pronounced in field resistance to most classes of fungicide but may play a role in resistance to azoles. MDR may also explain historical cases of resistance to aromatic hydrocarbon fungicides and dodine. In clinical situations, MDR development in Candida albicans (Robin) Berkhout mediated by ABC transporters in patients suffering from candidiasis is common after prolonged treatment with azoles. Factors that can explain this striking difference between agricultural and clinical situations are discussed. Attention is also paid to the risk of MDR development in plant pathogens in the future. Finally, the paper describes the impact of fungal drug transporters on drug discovery. Copyright © 2006 Society of Chemical Industry
Substituted α‐(phenylhydrazono)phenylacetonitrile derivatives. Part 1: A new class of uncoupler of oxidative phosphorylation
Authors: Danko Peter , Flury Thomas , Hall Roger G , Karrer Friedrich , Kienast Heinz , Kriz Miroslav , Leuenberger Katrin , Pascual Alfons , Steiger Arthur , Trah Stephan 
Published: February 2006

AbstractSubstituted α‐(phenylhydrazono)phenylacetonitrile derivatives have been discovered which constitute a series of potent uncouplers of oxidative phosphorylation. Systematic variation of substituents on both benzene rings has clearly demonstrated the importance of steric congestion around the ionisation site and delocalisation of negative charge in the anionic form. Replacement of the cyano group by other electron‐withdrawing groups leads to a dramatic decrease in uncoupling activity. The sub‐nanomolar levels of uncoupling activity found in certain members indicate that these compounds are the most potent uncouplers yet reported. Copyright © 2006 Society of Chemical Industry
Influence of Bacillus spp. isolated from maize agroecosystem on growth and aflatoxin B1 production by Aspergillus section Flavi
Authors: Bluma Romina V , Etcheverry Miriam G 
Published: February 2006

AbstractA total of 59 bacteria of the Bacillus genus were isolated from different components of a maize agroecosystem and their antifungal activity against Aspergillus section Flavi was evaluated. Thirty‐three and 46% of these bacteria were able to inhibit Aspergillus flavus Link and A. parasiticus Speare respectively at water activity (aw) 0.982; however, when aw was 0.955, these percentages were decreased and only three isolates were able to inhibit Aspergillus section Flavi. The majority of bacilli acted as contact antagonists, while a small number of isolates were able to form inhibition zones. In maize meal extract agar, Aspergillus section Flavi growth rate and aflatoxin B1 (AFB1) production were significantly reduced when these strains were paired at aw 0.982 with bacilli at all inoculum levels studied. However, two bacilli isolated were able to reduce growth rate and aflatoxin production when aw was 0.955. Lag phase increase followed the same general pattern as growth rate reduction. When Aspergillus section Flavi was grown in sterile maize in the presence of three Bacillus strains at aw 0.982, the reduction in count (colony‐forming units (cfu) g−1 maize) was less than 30%, except when Aspergillus section Flavi grew with Bacillus amyloliquefaciens UNRCLR. However, levels of detectable AFB1 were significantly reduced in these interactions at aw 0.982. Copyright © 2006 Society of Chemical Industry
The use of an alternative food source (red clover) as a means of reducing slug pest damage to winter wheat: towards field implementation
Authors: Brooks Andrew S , Wilcox Andrew , Cook Richard T , James Katherine L , Crook Mitchell J 
Published: February 2006

AbstractSlugs are major pests of many crops in the UK, including winter wheat, yet current methods of control are often unreliable. The aim of this study was to investigate three issues key to the successful field implementation of a control strategy that uses red clover as an alternative food source to reduce the amount of damage caused to winter wheat by the field slug, Deroceras reticulatum (Müller). A series of three experiments was designed to assess this aim. Firstly, under laboratory conditions, red clover was consumed in greater quantities than wheat, even when wheat was presented as a novel food. Secondly, red clover had no significant effects on the emergence and early growth of wheat in a polytunnel experiment. Both these results are crucial to the successful implementation of a strategy that uses red clover as an alternative food source. Lastly, the results of a field experiment were consistent with the results of the polytunnel experiment, in that red clover did not significantly affect wheat emergence. However, plots in which red clover was left to grow until the time of wheat harvest resulted in significantly lower (43%) wheat yields than plots without red clover. These results suggest that red clover must be removed from the field after the wheat has passed its vulnerable seedling stage. Recommendations for the potential use of red clover as an alternative food source for reducing damage to winter wheat in field conditions are discussed and opportunities for further work are suggested. Copyright © 2006 Society of Chemical Industry
Residues of diflubenzuron on horse chestnut (Aesculus hippocastanum) leaves and their efficacy against the horse chestnut leafminer, Cameraria ohridella
Authors: Nejmanová Jana , Cvačka Josef , Hrdý Ivan , Kuldová Jelena , Mertelík Josef , Muck Alexander , Nešněrová Petra , Svatoš Aleš 
Published: February 2006

AbstractResidues of the insect growth regulator diflubenzuron were quantified on horse chestnut (Aesculus hippocastanum L.) leaves treated with a diflubenzuron 480 g litre−1 SC, Dimilin. To analyse the samples, an analytical procedure was developed involving a simple extraction step followed by high‐performance liquid chromatography on an octadecyl‐modified silica column with methanol + 0.01 M ammonium acetate mobile phase. The results showed diflubenzuron to be highly stable on horse chestnut leaves; more than 4 months (127 days) after application, 38% (on average) of the insecticide still remained on/in the leaves. The data confirmed biological observations showing diflubenzuron's long‐term efficacy against the horse chestnut leafminer, Cameraria ohridella Deschka & Dimić, which is the most important pest of the horse chestnut in Europe. The hypothesis of possible penetration of diflubenzuron into the leaf mass is explored and discussed. Copyright © 2006 Society of Chemical Industry
Substituted α‐(phenylhydrazono)phenylacetonitrile derivatives. Part 2: synthesis and biological activity of pro‐pesticides
Authors: Flury Thomas , Hall Roger G , Karrer Friedrich , Kienast Heinz , Leuenberger Katrin , Pascual Alfons , Rindlisbacher Alfred , Trah Stephan , Widmer Hans‐Joerg 
Published: February 2006

AbstractPro‐pesticides of α‐(2,6‐dichloro‐4‐trifluoromethylphenylhydrazono)‐4‐nitrophenylacetonitrile have been prepared and tested against mite and insect pests. Variations in potency and spectrum were observed depending on the choice of cleavable pro‐moiety. Cleavage of the pro‐moiety was demonstrated in one case by measuring the rate of increase in the uncoupling activity using a mitochondrial preparation. Irradiation experiments have demonstrated a rapid isomerisation of the planar Z isomer to the E isomer, which is reversible. Copyright © 2006 Society of Chemical Industry
Fitness costs of laboratory‐selected imidacloprid resistance in the brown planthopper, Nilaparvata lugens Stål
Authors: Liu Zewen , Han Zhaojun 
Published: February 2006

AbstractImidacloprid has been used as a key insecticide to control the brown planthopper, Nilaparvata lugens Stål, for several years, but no obvious resistance has been identified in field populations as yet. To evaluate the risk, a field population was collected and selected with imidacloprid in the laboratory. After 37‐generation selection a strain with 250‐fold resistance had been successfully achieved. Fitness analysis by constructing life tables demonstrated that resistant hoppers had obvious disadvantages in their reproduction. The fitness of highly resistant hoppers had decreased dramatically (0.169 and 0.104) to only one‐fifth to one‐tenth of that of the susceptible strain. Hence it was concluded that the brown planthopper had the potential to develop high resistance to imidacloprid but that the lower fitness of resistant hoppers could result in a quick recovery of sensitivity when the population did not come into contact with imidacloprid. This means that a reasonable resistance management programme with less imidacloprid use may efficiently delay or even stop resistance development. Copyright © 2006 Society of Chemical Industry
A system dynamics analysis of boom and bust in the shrimp aquaculture industry
Authors: Arquitt Steve , Honggang Xu , Johnstone Ron 
Published: February 2006

AbstractDriven by growing international demand for shrimp and stagnating catches of wild shrimp, the shrimp aquaculture industry has grown remarkably over the past two decades. Initial hopes that farmed shrimp could provide an environmentally benign alternative to over‐exploited wild stocks have, however, proven disappointing. Although global growth has been steady, the industry has experienced dramatic production crashes at national and sub‐national scales associated with severe environmental damage. From a systems perspective, the industry is prone to exceed and consume its environmental carrying capacity, resulting in boom and bust patterns of development. In this paper we describe a dynamic commodity system model built to examine boom and bust in the shrimp aquaculture industry. Experiments with the model suggest that a policy that taxes the industry and rebates proceeds to licensed producers may help shift the system toward sustainability. Copyright © 2005 John Wiley & Sons, Ltd.
XMILE: towards an XML interchange language for system dynamics models
Authors: Diker Vedat G. , Allen Robert B. 
Published: February 2006

AbstractWe propose that XML should be used as an interchange language for system dynamics models and we have designed and implemented a demonstration that we call XMILE. We believe that there will be many benefits for the system dynamics community in developing a full‐scale interchange language. This paper discusses the motivation factors behind the idea of developing an interchange language for system dynamics models, and explains why XML is a good candidate framework. An initial implementation of XMILE is also presented along with initial findings about its applicability to models built on various system dynamics software platforms. Copyright © 2005 John Wiley & Sons, Ltd.
Statistical screening of system dynamics models
Authors: Ford Andrew , Flynn Hilary 
Published: February 2006

AbstractThis paper describes a pragmatic method of searching for the key inputs to a system dynamics model. This analysis is known as screening. The goal is to learn which of the many uncertain inputs stand out as most influential. The method is implemented with readily available software and relies on the simple correlation coefficient to indicate the relative importance of model inputs at different times in the simulation. The screening is demonstrated with two examples with step‐by‐step instructions. The paper recommends that screening analysis be used in an iterative process of screening and model expansion to arrive at tolerance intervals on model results. The appendices compare screening analysis with analytical methods to identify the key inputs to system dynamics models. Copyright © 2005 John Wiley & Sons, Ltd.
Improving strategic management with the fundamental principles of system dynamics
Authors: Warren Kim 
Published: February 2006

AbstractA system dynamics perspective has a powerful logic that offers substantial improvements in dealing with issues in strategic management, whether one‐off challenges or the continuous direction of enterprise strategy. First, successful strategic management of business and non‐commercial organisations requires attention to how performance is changing through time. Since performance reflects the state of resources in any period, steering strategy requires policies and decisions that control the flow rates of those resources. Lastly, this is complicated by the additional dependence of these resource flows on the current state of existing and potential resources at each point in time—a dependence that gives rise to feedback. These principles can be organised into a rigorous approach to strategy that is grounded in solid evidence from the situation of concern. Important implications from this perspective include the unavoidable causal ambiguity caused by accumulating resources, and the value of explicit and quantitative examination of resource development prior to investigating feedback structures. Copyright © 2005 John Wiley & Sons, Ltd.
Shape optimization problems for eigenvalues of elliptic operators
Authors: Belhachmi Z. , Bucur D. , Buttazzo G. , Sac‐Epée J.‐M. 
Published: February 2006

AbstractWe consider a general formulation for shape optimization problems involving the eigenvalues of the Laplace operator. Both the cases of Dirichlet and Neumann conditions on the free boundary are studied. We survey the most recent results concerning the existence of optimal domains, and list some conjectures and open problems. Some open problems are supported by efficient numerical computations.