bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deformation of elastomeric polyolefin spherulites
Authors: Wang H. P. , Chum S. P. , Hiltner A. , Baer E. 
Published: May 2009

AbstractThe ethylene‐octene block copolymers in this study consist of long crystallizable sequences with low comonomer content alternating with rubbery amorphous blocks with high comonomer content. The crystallizable blocks form lamellae that organize into space‐filling spherulites even when the fraction of crystallizable block is so low that the crystallinity is only 7%. These unusual spherulites are highly elastic and recover from strains as high as 300%. This new class of thermoplastic elastomers is fundamentally different from conventional elastomeric olefin copolymers that depend on isolated, fringed micellar‐like crystals to provide the junctions for the elastomeric network. The elastomeric block copolymers are shown to be unique in that a hierarchical organization of space‐filling lamellar spherulites provides the junctions for the elastomeric network. The deformation of the elastic spherulites is readily studied with small angle light scattering, wide angle X‐ray diffractograms, and atomic force microscopy. At strains in excess of 300%, the spherulites break up into a fibrillar structure following lamellar deformation processes that are similar to those established for high density ethylenic polymers. The crystalline transformation produces a stiffer elastomer that exhibits complete recovery on subsequent loadings. Similar experiments on elastomeric random ethylene‐octene copolymers where fringed micellar crystals provide the physical crosslinks that connect the rubbery, amorphous chain segments reveal significant differences. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1313–1330, 2009
Development and Characterisation of a Microwave‐heated Atmospheric Plasma Torch
Authors: Leins Martina , Alberts Lukas , Kaiser Mathias , Walker Matthias , Schulz Andreas , Schumacher Uwe , Stroth Ulrich 
Published: May 2009

AbstractAmong other applications, microwave plasma sources at atmospheric pressure are used for the decomposition of halogenated volatile organic compounds (VOC). The presented microwave plasma torch is based on an axially symmetric resonator. Simulations of the electric field distribution, Eigen frequency analyses and measurements of the resonant frequency resulted in an improved design. Microwaves of 2.45 GHz are fed into this cavity resulting in a sufficiently high electric field for ignition and maintaining stable plasma. The characterisation of the plasma is made with optical emission spectroscopy. The decomposition of VOC was analysed with FTIR‐spectroscopy, a mass spectrometer and an FID.
Effect of Cold Forming on Low‐Temperature Plasma Nitriding and Carburizing Characteristics of Austenitic Stainless Steel
Authors: Egawa Motoo , Matsuda Yasushi , Ueda Nobuhiro , Sone Takumi , Tsujikawa Masato , Nakata Kazuhiro 
Published: May 2009

AbstractThe cold‐rolled specimen of AISI304 and AISI316 were plasma nitrided and carburized at low temperature, and the S‐phase layers formed on the surface were investigated. In nitriding on AISI304 and AISI316, the thicknesses of the nitrided layers increased with an increase in rolling reduction. In plasma carburizing, on both steels, the thicknesses of the carburized layers were almost unchanged as the rolling reduction increased. In the nitriding, the growth of the S‐phase layer was accelerated by the deformation structure. However, in the carburizing, the growth of S‐phase layer was almost constant as the rolling reduction increased.
Sequence determinants of thermodynamic stability in a WW domain—An all‐β‐sheet protein
Authors: Jäger Marcus , Dendle Maria , Kelly Jeffery W. 
Published: May 2009

AbstractThe stabilities of 66 sequence variants of the human Pin1 WW domain have been determined by equilibrium thermal denaturation experiments. All 34 residues composing the hPin1 WW three‐stranded β‐sheet structure could be replaced one at a time with at least one different natural or non‐natural amino acid residue without leading to an unfolded protein. Alanine substitutions at only four positions within the hPin1 WW domain lead to a partially or completely unfolded protein—in the absence of a physiological ligand. The side chains of these four residues form a conserved, partially solvent‐inaccessible, continuous hydrophobic minicore comprising the N‐ and C‐termini. Ala mutations at five other residues, three of which constitute the ligand binding patch on the concave side of the β‐sheet, significantly destabilize the hPin1 WW domain without leading to an unfolded protein. The remaining mutations affect protein stability only slightly, suggesting that only a small subset of side chain interactions within the hPin1 WW domain are mandatory for acquiring and maintaining a stable, cooperatively folded β‐sheet structure.
Conformational changes in redox pairs of protein structures
Authors: Fan Samuel W. , George Richard A. , Haworth Naomi L. , Feng Lina L. , Liu Jason Y. , Wouters Merridee A. 
Published: May 2009

AbstractDisulfides are conventionally viewed as structurally stabilizing elements in proteins but emerging evidence suggests two disulfide subproteomes exist. One group mediates the well known role of structural stabilization. A second redox‐active group are best known for their catalytic functions but are increasingly being recognized for their roles in regulation of protein function. Redox‐active disulfides are, by their very nature, more susceptible to reduction than structural disulfides; and conversely, the Cys pairs that form them are more susceptible to oxidation. In this study, we searched for potentially redox‐active Cys Pairs by scanning the Protein Data Bank for structures of proteins in alternate redox states. The PDB contains over 1134 unique redox pairs of proteins, many of which exhibit conformational differences between alternate redox states. Several classes of structural changes were observed, proteins that exhibit: disulfide oxidation following expulsion of metals such as zinc; major reorganisation of the polypeptide backbone in association with disulfide redox‐activity; order/disorder transitions; and changes in quaternary structure. Based on evidence gathered supporting disulfide redox activity, we propose disulfides present in alternate redox states are likely to have physiologically relevant redox activity.
High‐energy water sites determine peptide binding affinity and specificity of PDZ domains
Authors: Beuming Thijs , Farid Ramy , Sherman Woody 
Published: May 2009

AbstractPDZ domains have well known binding preferences for distinct C‐terminal peptide motifs. For most PDZ domains, these motifs are of the form [S/T]‐W‐[I/L/V]. Although the preference for S/T has been explained by a specific hydrogen bond interaction with a histidine in the PDZ domain and the (I/L/V) is buried in a hydrophobic pocket, the mechanism for Trp specificity at the second to last position has thus far remained unknown. Here, we apply a method to compute the free energies of explicit water molecules and predict that potency gained by Trp binding is due to a favorable release of high‐energy water molecules into bulk. The affinities of a series of peptides for both wild‐type and mutant forms of the PDZ domain of Erbin correlate very well with the computed free energy of binding of displaced waters, suggesting a direct relationship between water displacement and peptide affinity. Finally, we show a correlation between the magnitude of the displaced water free energy and the degree of Trp‐sensitivity among subtypes of the HTRA PDZ family, indicating a water‐mediated mechanism for specificity of peptide binding.
Structural and biochemical analyses of YvgN and YtbE from Bacillus subtilis
Authors: Lei Jian , Zhou Yan‐Feng , Li Lan‐Fen , Su Xiao‐Dong 
Published: May 2009

AbstractBacillus subtilis is one of the most studied gram‐positive bacteria. In this work, YvgN and YtbE from B. subtilis, assigned as AKR5G1 and AKR5G2 of aldo‐keto reductase (AKR) superfamily. AKR catalyzes the NADPH‐dependent reduction of aldehyde or aldose substrates to alcohols. YvgN and YtbE were studied by crystallographic and enzymatic analyses. The apo structures of these proteins were determined by molecular replacement, and the structure of holoenzyme YvgN with NADPH was also solved, revealing the conformational changes upon cofactor binding. Our biochemical data suggest both YvgN and YtbE have preferential specificity for derivatives of benzaldehyde, such as nitryl or halogen group substitution at the 2 or 4 positions. These proteins also showed broad catalytic activity on many standard substrates of AKR, such as glyoxal, dihydroxyacetone, and DL‐glyceraldehyde, suggesting a possible role in bacterial detoxification.
NMR‐based characterization of a refolding intermediate of β2‐microglobulin labeled using a wheat germ cell‐free system
Authors: Kameda Atsushi , Morita Eugene‐Hayato , Sakurai Kazumasa , Naiki Hironobu , Goto Yuji 
Published: May 2009

AbstractIn patients with dialysis‐related amyloidosis, β2‐microglobulin (β2‐m) is a major structural component of amyloid fibrils. It has been suggested that the partial unfolding of β2‐m is a prerequisite to the formation of amyloid fibrils, and that the folding intermediate trapped by the non‐native trans‐Pro32 isomer leads to the formation of amyloid fibrils. Although clarifying the structure of this refolding intermediate by high resolution NMR spectroscopy is important, this has been made difficult by the limited lifetime of the intermediate. Here, we studied the structure of the refolding intermediate using a combination of amino acid selective labeling with wheat germ cell‐free protein synthesis and NMR techniques. The HSQC spectra of β2‐ms labeled selectively at either phenylalanine, leucine, or valine enabled us to monitor the structures of the refolding intermediate. The results suggested that the refolding intermediate has an overall fold and cores similar to the native structure, but contains disordered structures around Pro32. The fluctuation of the β‐sheet regions especially the last half of the βB strand and the first half of the βE strand, both suggested to be important for amyloidogenicity, may transform β2‐m into an amyloidogenic structure.
Regulation of PSA secretion and survival signaling by calcium‐independent phopholipase A2β in prostate cancer cells
Authors: Nicotera Thomas M. , Schuster David P. , Bourhim Mustapha , Chadha Kailash , Klaich Gary , Corral David A. 
Published: May 2009

AbstractBACKGROUNDSerum prostate specific antigen (PSA) levels in prostate cancer patients serve as a useful biomarker for diagnosing and monitoring prostate cancer. Recently, secreted PSA has been characterized as an autocrine survival factor through activation of Akt and induction of AR. In the normal prostate, PSA is secreted in the lumen of prostatic ducts to lyse proteins in the seminal coagulum.METHODSHowever, the mechanism for constitutive PSA secretion from benign prostate and its transport across the prostate‐blood barrier into serum are unknown. Regulation of peptide secretion by iPLA2‐β has been reported in non‐prostatic tissue and in prostate tissue iPLA2‐β is reported to be under androgen regulation. We investigated whether iPLA2 plays a role for in PSA secretion by comparing iPLA2 activity and expression in normal prostate epithelial RWPE‐1 cells and in LNCaP prostate cancer cells. Expression of the two active iPLA2‐β mRNA splice variants, LH‐iPLA2 and SH‐iPLA2, were increased and the inhibitory ankyrin‐iPLA2 isoform was markedly reduced in LNCaP cells as compared to normal prostate epithelial RWPE‐1 cells.RESULTSThese changes are consistent with a higher enzymatic activity in LNCaP cells. The iPLA2‐β‐specific inhibitor BEL inhibited PSA secretion and induced apoptosis in LNCaP cells. iPLA2 knockdown using SiRNA inhibited PSA secretion, downregulated AR and induced apoptosis. Exogenous PSA suppressed BEL‐induced apoptosis and neutralizing anti‐PSA antibody blocked the survival effect of PSA.CONCLUSIONSThese data indicate that iPLA2‐β participates in regulating PSA secretion and supports the concept that secreted PSA provides an autocrine survival function in LNCaP cells. Prostate 69:1270–1280, 2009. © 2009 Wiley‐Liss, Inc.
Serum adiponectin, C‐peptide and leptin and risk of symptomatic benign prostatic hyperplasia: Results from the prostate cancer prevention trial
Authors: Schenk Jeannette M. , Kristal Alan R. , Neuhouser Marian L. , Tangen Catherine M. , White Emily , Lin Daniel W. , Thompson Ian M. 
Published: May 2009

AbstractBACKGROUNDRecent epidemiologic studies have identified obesity as a risk factor for benign prostatic hyperplasia (BPH). We examined whether adiponectin, leptin, and C‐peptide were associated with incident, symptomatic BPH and whether these factors mediate the relationship between obesity and BPH risk.METHODSData are from Prostate Cancer Prevention Trial placebo arm participants who were free of BPH at baseline. Incident BPH (n = 698) was defined as treatment, two International Prostate Symptom Score (IPSS) values > 14, or an increase of ≥5 in IPSS from baseline documented on at least two occasions plus at least one score ≥12. Controls (n = 709) were selected from men reporting no BPH treatment or IPSS > 7 during the 7‐year trial. Baseline serum was analyzed for adiponectin, C‐peptide, and leptin concentrations.RESULTSNeither C‐peptide nor leptin was associated with BPH risk. The odds ratio [95% CI] contrasting highest to lowest quartiles of adiponectin was 0.65[0.47, 0.87] Ptrend = 0.004. Findings differed between levels of physical activity: there was a strong inverse association between adiponectin and BPH among moderately/very active men OR = 0.43 [0.29, 0.63], and no association among sedentary/minimally active men OR = 0.92 [0.65, 1.30] Pinteraction = 0.005. Adiponectin concentrations explained only a moderate amount of the relationship between obesity and BPH risk.CONCLUSIONSHigh adiponectin concentrations were associated with reduced risk of incident, symptomatic BPH. This association was limited to moderately/very active men; suggesting the relationship between obesity and BPH involves a complex interaction between factors affecting glucose uptake and insulin sensitivity. However, adiponectin is likely not the only mechanism through which obesity affects BPH risk. Prostate 69:1303–1311, 2009. © 2009 Wiley‐Liss, Inc.
Integrated pest management portfolios in UK arable farming: results of a farmer survey
Authors: Bailey Alastair S , Bertaglia Marco , Fraser Iain M , Sharma Abhijit , Douarin Elodie 
Published: May 2009

AbstractBACKGROUND: Farmers are faced with a wide range of pest management (PM) options that can be adopted in isolation or alongside complementary or substitute strategies. This paper presents the results of a survey of UK cereal producers, focusing on the character and diversity of PM strategies currently used by, or available to, farmers. In addition, the survey asked various questions pertaining to agricultural policy participation, attitude towards environmental issues, sources of PM advice and information and the important characteristics of PM technologies.RESULTS: The results indicate that many farmers do make use of a suite of PM techniques, and that their choice of integrated PM (IPM) portfolio appears to be jointly dictated by farm characteristics and government policy. Results also indicate that portfolio choice does affect the number of subsequent insecticide applications per crop.CONCLUSIONS: These results help to identify the type of IPM portfolios considered to be adoptable by farmers and highlight the importance of substitution in IPM portfolios. As such, these results will help to direct R&D effort towards the realisation of more sustainable PM approaches and aid the identification of potential portfolio adopters. These findings highlight the opportunity that a revised agri‐environmental policy design could generate in terms of enhancing coherent IPM portfolio adoption. Copyright © 2009 Society of Chemical Industry
Family ties and residential locations
Authors: Mulder Clara H. , Cooke Thomas J. 
Published: May 2009

AbstractIn this paper, and in the Special Issue it introduces, the focus is on the role of family ties in residential location choice and, conversely, the role of residential locations in maintaining family ties. Not only do events in the nuclear family trigger residential relocations, but nearby family members living outside the household prevent some people from moving away, whereas family members living far away trigger moves towards them. Furthermore, the current locations of family members are important to the frequency of contact and the exchange of support. The papers in this special issue all contribute to a growing appreciation of the inter‐relationships between the nuclear and extended families and residential relocation, and will contribute to a better understanding of both. Copyright © 2009 John Wiley & Sons, Ltd.
Geographical distances and support from family members
Authors: Mulder Clara H. , van der Meer Marieke J. 
Published: May 2009

AbstractWe address two questions: to what extent does geographical distance to parents, siblings and children living outside the household influence receiving support from them? And to what extent does the availability of other network members living closer play a part in receiving support? We use the Netherlands Kinship Panel Study and logistic regression models of receiving support from parents, children and siblings. The results indicate a strong impact of distance on support from family members, particularly from siblings and fathers but less so from mothers and children. Particularly siblings, sons and mothers are more likely to provide support if there are no other family members living closer. Copyright © 2009 John Wiley & Sons, Ltd.
Adult children and elderly parents as mobility attractions in Sweden
Authors: Pettersson Anna , Malmberg Gunnar 
Published: May 2009

AbstractThe aim of this paper is to investigate the extent to which elderly parents and adult children move close (or very close) to each other and how this mobility is influenced by socioeconomic conditions, family situation, gender and age. The analyses are based on register data for the years 2001 and 2002 covering all elderly parents and their adult children residing in Sweden. For instance, our analyses show a positive relationship between, on the one hand, moving close to an adult child or an elderly parent and, on the other, the presence of other family members (e.g. siblings and grandchildren). We also found that moving very close to adult children was more common among the young‐old and less common among the old‐old. One interpretation is that young‐old parents often move close to their adult children to have social contact or assist them, but as the parents grow older and their health weakens, care becomes increasingly important and, in the Swedish welfare state, it becomes more the responsibility of public institutions. Copyright © 2009 John Wiley & Sons, Ltd.
Contact and proximity of older people to their adult children: a comparison between Italy and Sweden
Authors: Bordone Valeria 
Published: May 2009

AbstractThis work extends the recent research on contact and geographical distance between older parents and their adult children. After a review of previous studies on this topic and an overview of the geography of the family in Italy and Sweden, multivariate analysis is used to answer the research questions ‘which variables account for the levels of kin contact and spatial proximity in Italy and Sweden?’ and ‘which ones explain the differences between the two countries?’ Population ageing and socio‐demographic changes in Italy raise the question of whether the differences between the ‘Mediterranean patriarchal model’ and the ‘Northern European model’ persist, or whether there is convergence towards patterns in vanguard countries such as Sweden. Of particular interest is the role played by education because of the increasing proportions of highly educated people. Logistic regression models on SHARE data always show higher levels of intergenerational proximity and contact in Italy than in Sweden. However, most of the socio‐demographic variables have similar impacts on them in the two countries. Interaction models and Seemingly Unrelated Estimation analyses lead to the conclusion that proximity has a different role in the two societies considered, affecting the frequency of contact as well. The results suggest that the available micro‐level indicators cannot fully explain the North–South divide in family behaviours, showing that cultural patterns are rather strong. Still, this work suggests a focus more on European similarities, rather than differences, in terms of intergenerational relationships and family behaviours. Copyright © 2009 John Wiley & Sons, Ltd.
Ethnic differences in spatial mobility: the impact of family ties
Authors: Zorlu Aslan 
Published: May 2009

AbstractIn the last three decades, the population of Amsterdam has been ‘coloured’ due to immigration flows from abroad and a low outflow rate among these immigrants and their descendants. The question is to what extent differences in the spatial mobility behaviours of migrants and natives are generated by neighbourhood characteristics – including the level of ethnic segregation and family ties? This article examines spatial mobility processes in the Amsterdam population using administrative individual data covering the entire population of the city. The analysis shows that Caribbean (Surinamese and Antillean) migrants have a higher probability of moving to the suburbs while Moroccans and Turks tend to rearrange themselves within the city. The estimates reveal that neighbourhood ‘quality’ has only a modest impact on the probability of moving, while family ties significantly hamper the out‐mobility of all individuals. The impact of family ties is the largest for Turkish and Moroccan migrants. Copyright © 2009 John Wiley & Sons, Ltd.
Hamilton cycles in 3‐out
Authors: Bohman Tom , Frieze Alan 
Published: May 2009

AbstractLet G3‐out denote the random graph on vertex set [n] in which each vertex chooses three neighbors uniformly at random. Note that G3‐out has minimum degree 3 and average degree 6. We prove that the probability that G3‐out is Hamiltonian goes to 1 as n tends to infinity. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Using simulation to interpret results from logit, probit, and other nonlinear models
Authors: Zelner Bennet A. 
Published: May 2009

AbstractIn a recent issue of this journal, Glenn Hoetker proposes that researchers improve the interpretation and presentation of logit and probit results by reporting the marginal effects of key independent variables at theoretically interesting or empirically relevant values of the other independent variables in the model, and also by presenting results graphically (Hoetker, 2007: 335, 337). In this research note, I suggest an alternative approach for achieving this objective: reporting differences in predicted probabilities associated with discrete changes in key independent variable values. This intuitive approach to interpretation is especially useful when the theoretically interesting or empirically relevant changes in independent variables values are not very small, and also for models that contain interaction terms (or higher‐order terms such as quadratics). Although the graphical presentations recommended by Hoetker implicitly embody this approach, they typically fail to include appropriate measures of statistical significance, and may therefore lead to erroneous conclusions. In order to calculate such measures, I recommend and demonstrate an intuitive simulation‐based approach to statistical interpretation, developed by King et al. (2000), that has gained widespread adherence in the field of political science. Throughout the article, I provide a running example based on research that has previously appeared in the Strategic Management Journal. Copyright © 2009 John Wiley & Sons, Ltd.