bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized Hankel operators on the Fock space II
Authors: Schneider Georg , Schneider Kristan
Published: July 2011

In this paper we study boundedness of generalized Hankel operators of the form \documentclass{article}\usepackage{amssymb,mathrsfs}\begin{document}\pagestyle{empty}${\rm H}_{{\overline{z}}^k}^l: {\mathscr F}^2\big (|z|^2\big )\rightarrow L^2\big (|z|^2\big )$\end{document} and thereby extend our results from 10. Here, \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\rm H_{{\overline{z}}^k}^l(f):=(\rm Id-\rm P_l)\big (\overline{z}^k f\big )$\end{document} and Pl is the projection onto \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$A^2_l\big (\mathbb C,| z|^2\big ):=\rm cl\big (\rm span\lbrace \overline{z} ^mz^n\,|\,m,n\in \mathbb N,\,m\le l\rbrace \big )$\end{document}. Additionally, we extend our results to general conjugate‐holomorphic L2 symbols. The arguments applied show a tight connection between operator theory and combinatorics.
Three‐dimensional Arrangement of Short DNA Oligonucleotides at Surfaces via the Synthesis of DNA‐branched Polyacrylamide Brushes by SI‐ATRP
Authors: Henry Olivier Y. F. , Mehdi Ahmed D. , Kirwan Sinead , Sanchez Josep Luis Acero , O'Sullivan Ciara K.
Published: July 2011

Short DNA oligonucleotide branches are incorporated into acrylamide brushes via surface initiated atom transfer radical polymerization in an attempt to increase DNA surface density by building three‐dimensional molecular architectures. ATR‐FTIR as well as hybridization studies followed by SPR confirm the incorporation of the DNA sequences into the polymer backbone. MALDI‐TOF analysis further suggests that six acrylamide monomer units are typically separating DNA branches present on a single brushes approximately 26 units long. This new approach offers a promising alternative to SAM‐based nucleic acid and aptamer sensors and could enable the realization of more complex soft materials of controlled architecture capable of both recognition and signaling by including additional optically or electrochemically active moieties.

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Macroporous Polymers with Hierarchical Pore Structure from Emulsion Templates Stabilised by Both Particles and Surfactants
Authors: Wong Ling L. Ching , Ikem Vivian O. , Menner Angelika , Bismarck Alexander
Published: July 2011

Inspired by natural porous materials, such as wood, bamboo and spongy bone consisting of individual structural units that are hierarchically arranged to optimise mechanical properties such as strength and toughness, synthetic macroporous polymers with enhanced physical properties were created by emulsion templating. Hierarchical poly(merised) high internal phase emulsions (HIPE) were created from HIPEs stabilised simultaneously by particles and a surfactant. In these HIPEs, surfactant stabilised and particle stabilised water droplets coexist, which upon polymerisation of the minority oil phase gives rise to macroporous polymers with a hierarchical pore structure. An improvement of the mechanical properties of our hierarchically structured macroporous polymers at equal porosity was observed, due to a more efficient packing of pores in a configuration that improves mechanical strength despite the presence of interconnecting pore throats. Moreover, the permeability of the hierarchically structured polyHIPEs are exceeding those measured for conventional polyHIPEs made from surfactant only stabilised HIPEs.

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Compartmentalization Effects on Bimolecular Termination in Atom Transfer Radical Polymerization in Nanoreactors
Authors: Zetterlund P. B.
Published: July 2011

The factors that determine the magnitude of the segregation effect in atom transfer radical polymerization (ATRP) in a dispersed system (miniemulsion, emulsion, etc.) have been elucidated by means of simulations based on two‐dimensional Smith–Ewart equations. The segregation effect is not a function of merely the average number of propagating radicals per particle, but also depends on the values of the deactivation and termination rate coefficients. This occurs as a result of these rate coefficients exerting an influence on the distribution of propagating radicals between the particles, which in turn affects the termination rate. The results provide further information as to how one can potentially exploit compartmentalization to improve livingness (end‐functionality) in ATRP in dispersed systems.

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Critical Micelle Concentration of Micelles with Different Geometries in Diblock Copolymer/Homopolymer Blends
Authors: Zhou Jiajia , Shi An‐Chang
Published: July 2011

It is well‐known that A‐B diblock copolymers in selective solvents or A‐homopolymers can form micelles of different shapes. The critical micelle concentration (CMC) of three basic micelle shapes (lamellar, cylindrical, and spherical) are calculated using the self‐consistent field theory formulated in the grand canonical ensemble. For a given set of molecular parameters, the stable micelle morphology is determined by a comparison of the CMC. The results confirm that micelles undergo a sequence of shape transitions, lamellar → cylindrical → spherical, when the A‐block of the diblock copolymer becomes longer. The results also reveal details about the micelle structure, such as the core radius and corona thickness. This information can be used to understand the effect of homopolymer molecular weight and monomer–monomer interaction on the micelle morphologies.

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BIMM: A Bias Induced Matrix Model for Incomplete Reciprocal Pairwise Comparison Matrix
Authors: Ergu Daji , Kou Gang , Peng Yi , Shi Yong , Shi Yu
Published: July 2011

The reciprocal pairwise comparison matrix is a well‐established technique and widely used in multiple criteria decision making methods. However, some entries in a pairwise comparison matrix may not be available in many real‐world decision problems. The goal of this paper is to propose a new method for estimating missing elements of an incomplete pairwise comparison matrix. A bias induced matrix model (BIMM), which combines the matrix multiplication and the properties of the original reciprocal pairwise comparison matrix, is used to calculate the missing entries in an incomplete pairwise comparison matrix. The proposed BIMM minimizes all bias values of the bias induced matrix to keep the global consistency. The missing value(s) can be estimated by solving the system of equations from the bias induced matrix. The theorems of the BIMM and the related corollaries are developed, and three numerical examples are introduced to illustrate the proposed model. Copyright © 2011 John Wiley & Sons, Ltd.
Lessons from probiotic–host interaction studies in murine models of experimental colitis
Authors: Claes Ingmar J. J. , De Keersmaecker Sigrid C. J. , Vanderleyden Jos , Lebeer Sarah
Published: July 2011

In inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as ‘live micro‐organisms that when administered in adequate amounts can confer a health benefit on the host’, have been suggested as nutritional supplements to restore these imbalances. The best response on probiotics among the different types of IBD appears to be in the case of ulcerative colitis. Although probiotics show promise in IBD in both clinical and animal studies, further mechanistic studies are necessary to optimize the use of probiotics as supporting therapy in IBD. Murine models of experimental colitis have been used for decades to study this pathology, and these models have been proven useful to search for new therapeutic approaches. The purpose of this review is to summarize probiotic–host interaction studies in murine models of experimental colitis and to evaluate how these models can further help in understanding these complex interactions. Unraveling the molecular mechanisms behind the beneficial effects will assist in better and possibly more efficient probiotic formulations.
Vitamin C modulates the interaction between adipocytes and macrophages
Authors: Garcia‐Diaz Diego F. , Campion Javier , Quintero Pablo , Milagro Fermin I. , Moreno‐Aliaga Maria J. , Martinez José. A.
Published: July 2011

Scope: Increased adiposity is related with monocyte infiltration into the adipose tissue that accentuates inflammation. Antioxidant treatments emerge as approaches to counteract this phenomenon.

Methods and results: Cocultures of differentiated 3T3‐L1 adipocytes and RAW264.7 macrophages were incubated for 24–72 h with/without 100 nM insulin and/or 200 μM vitamin C (VC). Nitric oxide (NO) secretion (24 h) was measured. Also, expression (24 h) and secretion (72 h) of MCP‐1, leptin and apelin were analyzed. NO secretion was significantly inhibited by insulin and VC only in cocultures. MCP‐1 expression/secretion was enhanced in cocultures. Insulin incubation reduced MCP‐1 expression in both cultures and VC only in controls. Both treatments inhibited MCP‐1 secretion in cocultures. Apelin gene expression was induced in cocultures. Insulin induced apelin mRNA expression, but VC inhibited its expression in cocultures under insulin treatment. Apelin secretion was notably induced by insulin and inhibited by VC in cocultures. Leptin expression was decreased in coculture, while presented no effects by VC.

Conclusion: VC importantly modulates the established pro‐inflammatory state in the interaction between adipocytes and macrophages.
A Study of Particle Nucleation in Dispersion Copolymerization of Methyl Methacrylate
Authors: Cockburn Robert A. , McKenna Timothy F. L. , Hutchinson Robin A.
Published: July 2011

The dispersion polymerization of methyl methacrylate (MMA) and its copolymerization with the bio‐renewable monomer γ‐methyl‐α‐methylene‐γ‐butyrolactone (MeMBL) is studied in a methanol/water mixture. The addition of MeMBL to an MMA dispersion decreases both rate and particle size (PS), while rate decreases and PS increases when the fraction of methanol in the continuous phase is increased. The differing effects of comonomer and continuous phase composition can be attributed to monomer partitioning and critical chain length (jcrit) of the radicals formed in solution. A cobalt(II) catalytic chain transfer agent (CCTA) was used to determine a value of 20–30 monomer units for jcrit in MMA dispersion polymerization. A distinct population of small particles, about one‐tenth as large as the 1–2 µm mature particles, was observed throughout the entire course of the dispersion polymerization; it is these particles, most likely aggregates of nuclei continuously generated in solution, that are swept up by the mature particles during growth.

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Developmental Stress and Survival among the Mid Upper Paleolithic Sunghir Children: Dental Enamel Hypoplasias of Sunghir 2 and 3
Authors: Guatelli‐Steinberg D. , Buzhilova A. P. , Trinkaus E.
Published: July 2011

The Sunghir 2 and 3 late juvenile to early adolescent immature skeletons, from the Mid Upper Paleolithic (Eastern Gravettian) of northern Russia, exhibit several episodes of dental enamel hypoplasias. Those of the older male Sunghir 2 relate principally to a stress episode in the third year post‐natal, although subsequent minor stress episodes may be indicated. They are not accompanied by other marked developmental abnormalities. The younger female Sunghir 3 exhibits at least three episodes of pronounced post‐natal stress through the third to fifth years post‐natal, followed by femoral and tibial growth arrest lines that formed shortly before her death at 9–11 years. These first decade post‐natal stress episodes of Sunghir 3 may be related to the same developmental condition that produced her abnormally bowed femora pre‐natally and/or to continued frailty related to that condition. Surviving these stress episodes for different lengths of time, both Sunghir 2 and 3 were awarded the most elaborate Paleolithic burial known. Copyright © 2011 John Wiley & Sons, Ltd.
MLL gene rearrangements in infant leukemia vary with age at diagnosis and selected demographic factors: A Children's Oncology Group (COG) study
Authors: Sam Thien N. , Kersey John H. , Linabery Amy M. , Johnson Kimberly J. , Heerema Nyla A. , Hilden Joanne M. , Davies Stella M. , Reaman Gregory H. , Ross Julie A.
Published: July 2011

Background

Infant leukemias have a high frequency of mixed lineage leukemia (MLL) gene rearrangements.

Procedure

Using data from a large etiologic study, we evaluated the distribution of selected demographic factors among 374 infant leukemia cases by leukemic subtype, MLL status and diagnosis age.

Results

Overall, 228 cases were MLL+. Compared to white infants, black infants were significantly less likely to have MLL+ leukemia. Further, there was a statistically significantly higher age at diagnosis for infants with t(9;11) translocations compared to all other translocation partners in both acute lymphoblastic leukemia and acute myeloid leukemia cases.

Conclusion

These patterns may provide important etiological insight into the biology of infant leukemia. Pediatr Blood Cancer 2012; 58: 836–839. © 2011 Wiley Periodicals, Inc.
Differential proteomic analysis of highly purified placental cytotrophoblasts in pre‐eclampsia demonstrates a state of increased oxidative stress and reduced cytotrophoblast antioxidant defense
Authors: Johnstone Edward D. , Sawicki Grzgorz , Guilbert Larry , Winkler‐Lowen Bonnie , Cadete Virgilio J. J. , Morrish Donald W.
Published: July 2011

Proteomics were performed using highly (99.99%) purified cytotrophoblasts from six normal and six pre‐eclamptic placentas. Eleven proteins were found which decreased in pre‐eclampsia (actin, glutathione S‐transferase, peroxiredoxin 6, aldose reductase, heat shock protein 60 (Hsp60), two molecular forms of heat shock protein 70 (Hsp70) β‐tubulin, subunit proteasome, ezrin, protein disulfide isomerase, and phosphoglycerate mutase 1). Only one protein, α‐2‐HS‐glycoprotein (fetuin), was found to increase its expression. Western blots of actin, Hsp70, ezrin, and glutatione S‐transferase confirmed decrease in protein expression. Many of the proteins that decreased are consistent with a state of oxidative stress in the pre‐eclamptic placenta and a decreased cytotrophoblast defense against and response to oxidative stress.
Polymer brushes on multiwalled carbon nanotubes by activators regenerated by electron transfer for atom transfer radical polymerization
Authors: Aitchison Tony J , Ginic‐Markovic Milena , Saunders Martin , Fredericks Peter , Valiyaveettil Suresh , Matisons Janis G. , Simon George P.
Published: July 2011

The synthesis and characterization of multiwalled carbon nanotube (MWCNT) polymer brushes produced by activators regenerated by electron transfer (ARGET) in atom‐transfer radical polymerization (ATRP) was discussed. The polymer brushes were synthesized by esterification of the MWCNT carboxylic acid groups with hydroxyethyl‐2‐bromoisobutyrate and subsequently used in ARGET ATRP. This created a well defined living polymer brush carbon nanotube of comparatively low polydispersity and a polymer layer 10 nm thick. As, ARGET ATRP uses only minute concentrations of copper (II) catalyst, and is less sensitive to air compared to other living polymerization techniques, this process is a more industry‐compatible route for the commercialization of such materials. The structural and chemical properties were explored by a range of techniques including high resolution transmission electron microscopy, gel permeation chromatography, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, the polymer brush nanotubes were explored for their potential use in films and as fillers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Cellulose‐based graft copolymers with controlled architecture prepared in a homogeneous phase
Authors: Raus Vladimír , Štěpánek Miroslav , Uchman Mariusz , Šlouf Miroslav , Látalová Petra , Čadová Eva , Netopilík Miloš , Kříž Jaroslav , Dybal Jiří , Vlček Petr
Published: July 2011

Cellulose‐based macroinitiators with predetermined number of initiation sites were synthesized by acylation of microcrystalline cellulose AVICEL PH‐101 with 2‐bromoisobutyryl bromide under homogeneous reaction conditions in the N,N‐dimethylacetamide/LiCl solvent system. The influence of different methods of cellulose activation on acylation efficiency and reproducibility was investigated. Best results were obtained using thermal activation under reduced pressure or the newly introduced protocol based on solvent exchange to 1,4‐dioxane. Prepared macroinitiators were used for grafting with styrene and methyl methacrylate (MMA) using optimized atom transfer radical polymerization reaction conditions to achieve well‐controlled polymerizations with high initiation efficiency. For MMA grafting, the initiation efficiency was shown to be dependent on certain reaction conditions, such as type of solvent, monomer concentration, or the presence of a sacrificial initiator. In addition, single‐electron transfer living radical polymerization with Cu(0) as the catalyst was used for the first time to prepare cellulose‐graft‐polystyrene and cellulose‐graft‐poly(MMA) copolymers in a homogeneous phase. In summary, homogeneous reaction conditions, stoichiometric control in the preparation of macroinitiators, and controlled grafting jointly allowed for an extensive control of copolymers architecture, that is, density of grafting, composition, and molecular parameters of grafts. Moreover, some of the prepared copolymers were characterized by static and dynamic light scattering and microscopic techniques (transmission electron microscopy and atomic force microscopy). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Bulk heterojunction polymer solar cells based on binary and ternary blend systems
Authors: Park Song Ju , Cho Jung Min , Byun Won‐Bae , Lee Jong‐Cheol , Shin Won Suk , Kang In‐Nam , Moon Sang‐Jin , Lee Sang Kyu
Published: July 2011

Polymer solar cells (PSCs) were fabricated using a ternary blend film consisting two conjugated polymers and a soluble fullerene derivative as the donor and acceptor materials, respectively. And, to compare ternary blend system, the single‐component copolymers consisting of the repeating units of each of the copolymers, used in ternary blend solar cells, were designed and synthesized for use as the electron donor materials in binary blend solar cells. We systematically investigated the field‐effect carrier mobilities and the optical, electrochemical, and photovoltaic properties of the copolymers. Under optimized conditions, the binary blend polymer systems showed power conversion efficiencies (PCEs) for the PSCs in the range 3.87–4.16% under AM 1.5 illumination (100 mW cm−2). All polymers exhibited similar PCEs that did not depend on the ratio of repeating units. The binary blend solar cell containing a single‐component copolymer as the electron donor material performed better than the ternary blend solar cell in this work. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Copolymerization of norbornene with methoxycarbonylnorbornene catalyzed by Ni{CF3C(O)CHC[N(naphthyl)]CH3}2/B(C6F5)3 catalytic system and good processability for Dry/Wet phase inversion and electrospinning technique
Authors: Xing Yuepeng , Chen Yiwang , He Xiaohui
Published: July 2011

Copolymerization of norbornene (NB) with methoxycarbonylnorbornene (NB‐COOCH3) was carried out with catalytic system of Ni{CF3C(O)CHC[N(naphthyl)]CH3}2 and B(C6F5)3 in toluene. The catalytic system exhibited higher activity 2.69 × 105 (gpolymer/mol Ni h) for copolymerization of norbornene and methoxycarbonylnorbornene. The influence results of the comonomer feed content on the polymerization showed that the NB‐COOCH3 has a very high insertion ratio in all copolymers, and the NB‐COOCH3 content in copolymers can be controlled to be 7.9–77.6 mol % at content of 10–90 mol % of the NB‐COOCH3 in the monomer feeds ratios. The reactivity ratios, rNB‐COOCH3 = 0.578 and rNB = 0.859, were determined by the Kelen–TÜdÕs method. Copolymers were processed by solution casting method, dry/wet phase inversion technique, and electrospinning. The films prepared by solution casting method showed good transparency in the visible region. The membranes processed by dry/wet phase inversion technique were microporous structures. The fibers diameters fabricated by electrospinning were about 3 μm. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Novel perfluorocyclobutyl aryl ether‐based well‐defined amphiphilic block copolymer
Authors: Yao Wenqiang , Li Yongjun , Zhang Sen , Liu Hao , Huang Xiaoyu
Published: July 2011

A series of fluorine‐containing amphiphilic diblock copolymers comprising hydrophobic poly(p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate) (PTPFCBPMA) and hydrophilic poly(2‐(diethylamino)ethyl methacrylate) (PDEAEMA) segments were synthesized via successive reversible addition fragmentation chain transfer (RAFT) polymerizations. RAFT homopolymerization of p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate was first initiated by 2,2′‐azobisisobutyronitrile using cumyl dithiobenzoate as chain transfer agent, and the results show that the procedure was conducted in a controlled way as confirmed by the fact that the number‐average molecular weights increased linearly with the conversions of the monomer while the polydispersity indices kept below 1.30. Dithiobenzoate‐capped PTPFCHPMA homopolymer was then used as macro‐RAFT agent to mediate RAFT polymerization of 2‐(diethylamino)ethyl methacrylate, which afforded PTPFCBPMA‐b‐PDEAEMA amphiphilic diblock copolymers with different block lengths and narrow molecular weight distributions (Mw/Mn ≤ 1.28). The critical micelle concentrations of the obtained amphiphilic diblock copolymers were determined by fluorescence spectroscopy technique using N‐phenyl‐1‐naphthylamine as probe. The morphology and size of the formed micelles were investigated by transmission electron microscopy and dynamic light scattering, respectively. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Photoresponsive self‐assembling structures from a pyrene‐based triblock copolymer
Authors: Menon Sajith , Das Suresh
Published: July 2011

A new photoresponsive amphiphilic triblock copolymer, poly(pyrenylmethyl methacrylate)‐block‐polystyrene‐block‐poly(ethylene oxide) (PPy‐b‐PSt‐b‐PEO), was synthesized using atom‐transfer radical polymerization. Formation of colloidal aggregates of the polymer was observed in solutions under controlled conditions due to the amphiphilic nature of the polymer. Irradiation of the polymer aggregates using UV light resulted in the photodissociation of 1‐pyrenemethanol units from the polymer back‐bone resulting in break‐up of the aggregates mainly due to the hydrophilic nature of the residual polymer. The use of these polymer aggregates to trap hydrophobic fluorescent dyes in water and its controlled release on exposure to UV light has also been explored. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Glow‐discharge Electrolysis Plasma Induced Synthesis of Polyvinylpyrrolidone/Acrylic Acid Hydrogel and its Adsorption Properties for Heavy‐metal Ions
Authors: Lu Quanfang , Yu Jie , Gao Jinzhang , Yang Wu , Li Yan
Published: July 2011

Polyvinylpyrrolidone/acrylic acid (PVP/AAc) hydrogel is synthesized using glow‐discharge electrolysis plasma (GDEP) technique in an aqueous solution. To optimize the synthesis conditions, the following parameters are examined in detail: discharge voltage, discharge time, mass ratio of PVP to AAc, and content of crosslinker to acrylic acid. The properties of hydrogels are characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X‐ray spectrometer (EDS), Fourier transform infrared spectroscopy (FT‐IR), and X‐ray photoelectron spectroscopy (XPS). The results show that both chemical complexation and ion‐exchange play an important role for Pb(II) adsorption onto PVP/AAc hydrogel. Langmuir and Freundlich adsorption models are applied to describe the isotherms at room temperature, and a good agreement between the Langmuir model the experimental data is obtained.

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Laboratory and field comparisons of insecticides to reduce infestation of Drosophila suzukii in berry crops
Authors: Bruck Denny J , Bolda Mark , Tanigoshi Lynell , Klick Jimmy , Kleiber Joseph , DeFrancesco Joe , Gerdeman Beverly , Spitler Hollis
Published: July 2011

BACKGROUND: The spotted wing Drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), is an invasive pest of small‐fruit crops. Unlike most other Drosophila, this insect is able to oviposit into and damage ripe and ripening fruit, making it unmarketable. Because this is a new pest in the United States, it is necessary to identify registered insecticides to manage this insect effectively in conventional and organic production systems.

RESULTS: The present laboratory bioassays and field trials identified a number of insecticides representing various modes of action that are effective in controlling D. suzukii. Products that performed well in the laboratory bioassay also performed well in the field, indicating that screening of new chemistries in the laboratory is a worthy exercise. Field application of pyrethoids, organophosphates or spinosyns provided 5–14 days of residual control of D. suzukii. The efficacy of the neonicotinoids as adulticides was not satisfactory compared with the other contact‐mode‐of‐action chemistries. Based on the zero tolerance by the small‐fruit industry and the individual effects mentioned above, neonicotinoids are not currently recommended for D. suzukii management.

CONCLUSIONS: There are effective insecticides registered for controlling D. suzukii infestations in susceptible small‐fruit crops. Copyright © 2011 Society of Chemical Industry
Pyrethroid insecticide resistance in British populations of the cabbage whitefly, Aleyrodes proletella
Authors: Springate Simon , Colvin John
Published: July 2011

BACKGROUND: The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassica crops in certain regions of the United Kingdom. In order to investigate the contribution of pesticide resistance to this phenomenon, A. proletella populations were sampled from five different areas in England in 2008 and 2009. Adult residual leaf‐dip bioassays were carried out using pyrethroid and neonicotinoid insecticides.

RESULTS: Significant resistance to pyrethroids was found in multiple samples collected from two areas. No evidence of cross‐resistance to neonicotinoids was found in a subset of the pyrethroid‐resistant populations. While the patterns of resistance to different pyrethroids were broadly correlated, the magnitude of resistance factors differed substantially. Survival of strains at a putative diagnostic concentration of lambda‐cyhalothrin was found to provide a guide to their LC50. Significant differences in LC50 were found when different brassica crops were used in the bioassay, although the resistance patterns between strains were maintained.

CONCLUSION: Reduced susceptibility to multiple pyrethroid insecticides exists in populations of A. proletella in the United Kingdom, corresponding to recent major outbreaks. The mechanism(s) of resistance are yet to be determined, but molecular structural differences in pyrethroids probably influence the magnitude of cross‐resistance within this group of insecticides. Copyright © 2011 Society of Chemical Industry
Mid‐infrared emission from Er3+ and energy transfer in Er3+–Yb3+ and Er3+–Nd3+ co‐doped Ga2S3–GeS2–Sb2S3 glasses
Authors: Ichikawa Manabu , Ishikawa Yoichi , Wakasugi Takashi , Kadono Kohei
Published: July 2011

The radiative and nonradiative transitions of the first three excited levels of Er3+ doped in Ga2S3–GeS2–Sb2S3 glass were investigated. Particularly, we focused on the 4I9/2 and 4I11/2 which are the initial and final levels of mid‐infrared emission around 4 µm. The effects of energy transfer from these levels to co‐doped rare‐earth ions, Yb3+ and Nd3+, were estimated. The population of the final level, 4I11/2, was efficiently quenched by the energy transfer to the Yb3+, 2F5/2 level. This leads to the population inversion between the initial and final levels. In the Nd3+‐co‐doped glass, on the contrary, the initial level, 4I9/2, was more rapidly quenched than the final level, 4I11/2, through the energy transfer to Nd3+, 4F5/2 + 2H9/2.
Electric field induced dynamics of charged species in metal oxide devices: Diffusion equation analysis
Authors: Kiselev I. , Sommer M. , Sysoev V. V. , Skorokhodov S. L.
Published: July 2011

Distributions of charged species over metal oxide appearing after a step‐like voltage bias application and under the alternate voltage respectively are examined in framework of the diffusion initial‐boundary value problem. When possible, the solutions are derived in analytical form to make general conclusions. The solutions obtained are helpful in particular to ascertain limits of the diffusion approach to explain the transient behavior of non‐linear electric potential distributions over gas sensitive metal oxide films and the low‐frequency abnormalities of impedance spectra of such films.
Mechanical loss of calcium fluoride at cryogenic temperatures
Authors: Schwarz Christian , Heinert Daniel , Seidel Paul , Tünnermann Andreas , Hammond Giles D. , Nawrodt Ronny
Published: July 2011

Low mechanical loss materials are in great demand for micro‐mechanical applications as well as high precision instrumentation. We describe low mechanical loss measurements of a calcium fluoride (CaF2) bulk sample. A new mechanical relaxation process was observed for frequencies in the range from 31 to 64 kHz and temperatures of 10 to 50 K. The activation energy of this process was found to be 10 meV. This relaxation process increases the mechanical loss significantly and thus sets limits to the application of this material at these temperatures.
A Double‐blind, Placebo‐controlled Investigation of the Effects of Passiflora incarnata (Passionflower) Herbal Tea on Subjective Sleep Quality
Authors: Ngan A. , Conduit R.
Published: July 2011

Passiflora incarnata is a traditional herbal sedative, anxiolytic and a popular sleep aid used for the treatment of sleep disturbance. Several controlled experiments have demonstrated enhanced sleep in laboratory animals, but clinical trials in humans are lacking. The aim of the present study was to investigate the efficacy of Passiflora incarnata herbal tea on human sleep, as measured using sleep diaries validated by polysomnography (PSG). This study featured a double‐blind, placebo‐controlled, repeated‐measures design with a counterbalanced order of treatments (passionflower vs placebo tea), separated by a 1 week ‘washout’ period. Forty‐one participants (18–35 years) were exposed to each treatment for a week, whereby they consumed a cup of the tea and filled out a sleep diary for 7 days, and completed Spielberger's state‐trait anxiety inventory on the seventh morning. Ten participants also underwent overnight PSG on the last night of each treatment period. Of six sleep‐diary measures analysed, sleep quality showed a significantly better rating for passionflower compared with placebo (t(40) = 2.70, p < 0.01). These initial findings suggest that the consumption of a low dose of Passiflora incarnata, in the form of tea, yields short‐term subjective sleep benefits for healthy adults with mild fluctuations in sleep quality. Copyright © 2011 John Wiley & Sons, Ltd.
Quercetin Inhibits α‐MSH‐stimulated Melanogenesis in B16F10 Melanoma Cells
Authors: Yang Yeon‐Mi , Son Young‐Ok , Lee Seung‐Ah , Jeon Young‐Mi , Lee Jeong‐Chae
Published: July 2011

Quercetin is known to inhibit tyrosinase activity and melanin production in melanocytes. However, several reports suggest that quercetin has different and opposite effects on melanogenesis. This study examined the precise effects of quercetin on melanogenesis using cell‐free assay systems and melanocytes. Quercetin inhibited the monophenolase and diphenolase activities of tyrosinase, and melanin synthesis in cell‐free assay systems. Quercetin induced mild stimulation of the tyrosinase activity and dihydroxyphenylalaminechrome tautomerase (TRP‐2) expression but only at low concentrations (<20 μm) in B16F10 melanoma cells. In contrast, the addition of 50 μm quercetin to the cells led to a significant decrease in the activity and synthesis of tyrosinase, as well as a decrease in the expression of tyrosinase‐related protein‐1 and TRP‐2 proteins, regardless of the presence or absence of α‐melanocyte stimulating hormone (α‐MSH). Quercetin also reduced the intracellular cAMP and the phosphorylated protein kinase A levels in α‐MSH‐stimulated B16F10 cells. Moreover, quercetin (20 μm) diminished the expression and activity of tyrosinase, and melanin content in cultured normal human epidermal melanocytes. These effects were not related to its cytotoxic action. Although the in vivo effects of quercetin are still unclear, these results suggest that quercetin could play important roles in controlling melanogenesis. Copyright © 2011 John Wiley & Sons, Ltd.
Preventative Effects of 4,4'‐Diphenylmethane‐bis(methyl) Carbamate Isolated from Cortex Mori on Human Umbilical Vein Endothelial Cell Dysfunction Induced by Advanced Glycation End Products
Authors: Feng Liang , Xu You‐hua , Wang Shan‐shan , Au‐yeung Wai , Zheng Zhao‐guang , Wang Ru‐shang , Zhu Quan , Xiang Ping
Published: July 2011

Advanced glycation end‐products (AGEs) have been regarded as an initial motivating factor in the pathogenesis of endothelial dysfunction in diabetic complications. 4,4'‐Diphenylmethane‐bis(methyl) carbamate (DMPC), a carbamate compound, was isolated from Cortex Mori and its prevention effects against AGEs‐induced endothelial dysfunction were studied. 4,4'‐Diphenylmethane‐bis(methyl) carbamate significantly reduced cell apoptosis to normal level at 10−9 mol/L concentration. Advanced glycation end‐products up‐regulated the expression of Bad and Bax and down‐regulated Bcl‐2 proteins, and pretreatment with DMPC significantly down‐regulated Bad and Bax while up‐regulating Bcl‐2 expressions. In addition, ICAM (intercellular adhesion molecule)‐1 and TGF (transforming growth factor)‐β1 expressions in human umbilical vein endothelial cell (HUVEC) were significantly enhanced by AGEs. More importantly, these increases of ICAM‐1 and TGF‐β1 expressions were reduced meaningfully with the pretreatment of DMPC. All the results showed DMPC had prevention effects against the progression of AGE‐induced endothelial dysfunction, and this compound might be a promising agent against endothelial dysfunction in diabetic vascular complications. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of jackfruit waste flour on the properties of poly(vinyl alcohol) film
Authors: Ooi Z.X. , Ismail H. , Abu Bakar A. , Aziz N.A.
Published: July 2011

A series of biodegradable polymer films based on poly(vinyl alcohol) (PVOH) and jackfruit waste flour (JWF) was prepared in the presence of water and glycerol and cast by a solution casting method. The JWF was introduced as a promoter of biodegradability. The blended films were evaluated for their tensile properties, water absorption, water vapor transmission rate (WVTR), and degradation behavior under different environmental conditions such as natural weathering and natural soil. The tensile strength (1.7–6.4 MPa) and elongation at break (13–108%) of the PVOH/JWF films were lower than those of unfilled PVOH film (26MPa and 238%). However, the Young's modulus values (157–196 MPa) of the PVOH/JWF films were higher than that of unfilled PVOH film (137 MPa). The PVOH/JWF blended films showed higher water absorption and WVTR, which increased with increasing JWF content. Biodegradability tests revealed that the presence of JWF stimulated the degradation rate and caused the weight loss and reduction in tensile properties of the PVOH/JWF blended films. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Preparation and evaluation of some benzophenone terpolymers as photostabilizers for rigid PVC
Authors: Braun Dietrich , Rabie Samira T. , Khaireldin Nahid Y. , Abd El‐Ghaffar Mahmoud A.
Published: July 2011

Some terpolymeric stabilizers based on polymerizable derivatives of 2,4‐dihydroxy‐benzophenone were prepared and evaluated as photostabilizers for rigid poly(vinyl chloride) (PVC). The prepared terpolymers, namely, (methyl methacrylate)/(2‐hydroxyethyl methacrylate)/2‐hydroxy‐4‐methacryloxybenzophenone (MMA/HEMA/HBMA) and (methyl methacrylate)/(2‐hydroxyethyl methacrylate)/2‐hydroxy‐4‐(3‐methacryloxy‐2‐hydroxypropoxy)benzophenone (MMA/HEMA/PBMA), were characterized, and their structures were confirmed by GPC, thermogravimetric analysis, FTIR, and ultraviolet‐visible (UV–vis) spectroscopy. The results revealed that the stabilizing effect of these terpolymers increased upon increasing the stabilizer concentration and the content of UV absorber units in the terpolymers. Promising results were achieved, and the prepared terpolymers showed higher stabilizing efficiency than the corresponding monomeric UV absorbers of low molecular weight. J. VINYL ADDIT. TECHNOL., 2011.© 2011 Society of Plastics Engineers
The use of decision trees for cost‐sensitive classification: an empirical study in software quality prediction
Authors: Seliya Naeem , Khoshgoftaar Taghi M.
Published: July 2011

This empirical study investigates two commonly used decision tree classification algorithms in the context of cost‐sensitive learning. A review of the literature shows that the cost‐based performance of a software quality prediction model is usually determined after the model‐training process has been completed. In contrast, we incorporate cost‐sensitive learning during the model‐training process. The C4.5 and Random Forest decision tree algorithms are used to build defect predictors either with, or without, any cost‐sensitive learning technique. The paper investigates six different cost‐sensitive learning techniques: AdaCost, Adc2, Csb2, MetaCost, Weighting, and Random Undersampling (RUS). The data come from case study include 15 software measurement datasets obtained from several high‐assurance systems. In addition, to a unique insight into the cost‐based performance of defection prediction models, this study is one of the first to use misclassification cost as a parameter during the model‐training process. The practical appeal of this research is that it provides a software quality practitioner with a clear process for how to consider (during model training) and analyze (during model evaluation) the cost‐based performance of a defect prediction model. RUS is ranked as the best cost‐sensitive technique among those considered in this study. © 2011 John Wiley & Sons, Inc. WIREs Data Mining Knowl Discov 2011 1 448–459 DOI: 10.1002/widm.38

This article is categorized under:

Algorithmic Development > Hierarchies and Trees

Technologies > Classification

Technologies > Prediction
On the limits of refinement-testing for model-checking CSP
Authors: Murray Toby
Published: July 2011

Refinement-checking, as embodied in tools like FDR, PAT and ProB, is a popular approach for model-checking refinement-closed predicates of CSP processes. We consider the limits of this approach to model-checking these kinds of predicates. By adopting Clarkson and Schneider’s hyperproperties framework, we show that every refinement-closed denotational predicate of finitely-nondeterministic, divergence-free CSP processes can be written as the conjunction of a safety predicate and the refinement-closure of a liveness predicate. We prove that every safety predicate is refinement-closed and that the safety predicates correspond precisely to the CSP refinement checks in finite linear observations models whose left-hand sides (i.e. specification processes) are independent of the systems to which they are applied. We then show that there exist important liveness predicates whose refinement-closures cannot be expressed as refinement checks in any finite linear observations model , divergence-strict model or non-divergence-strict divergence-recording model , i.e. in any standard CSP model suitable for reasoning about the kinds of processes that FDR can handle, namely finitely-branching ones. These liveness predicates include liveness properties under intuitive fairness assumptions, branching-time liveness predicates and non-causation predicates for reasoning about authority. We conclude that alternative verification approaches, besides refinement-checking, currently under development for CSP should be further pursued.
The Methods of Reconstruction of Pancreatic Digestive Continuity After Pancreaticoduodenectomy: A Meta‐Analysis of Randomized Controlled Trials
Authors: Yang Sun Hu , Dou Ke Feng , Sharma Neel , Song Wen Jie
Published: July 2011

Background

Pancreatic fistula (PF) is an important factor responsible for the considerable morbidity associated with pancreaticoduodenectomy (PD). There have been many techniques proposed for the reconstruction of pancreatic digestive continuity to prevent fistula formation but which is best is still highly debated. We carried out a systematic review and meta‐analysis to determine the effectiveness of methods of anastomosis after PD.

Methods

A full literature search was conducted in the Cochrane Controlled Trials Register Databases, Medline, and other resources irrespective of language. Randomized controlled trials (RCTs) were considered for inclusion. Analyses were carried out using RevMan software.

Results

In all, ten RCTs that included a total of 1,408 patients were included. The meta‐analysis showed that the PF, postoperative complications, biliary fistula, mortality, reoperation, and length of hospital stay were not statistically different between the pancreaticogastrostomy (PG) and pancreaticojejunostomy (PJ) groups. The PF, postoperative complications, mortality, and reoperation were not statistically different between the duct‐to‐mucosa PJ and PJ groups. Binding PJ significantly decreased the PF and postoperative complications compared with conventional PJ. The PF, postoperative complications, and mortality were not statistically different between ligation of the pancreatic duct without anastomosis versus PJ.

Conclusion

No pancreatic reconstruction technique after PD was found to be applicable to all kinds of pancreatic remnants in our systematic review and meta‐analysis. Some new approaches such as binding PJ and modified PG will be considered for study in the future.
Evaluation of an Improved Indirect Method for the Analysis of 3‐MCPD Esters Based on Acid Transesterification
Authors: Ermacora Alessia , Hrncirik Karel
Published: July 2011

The quantification of 3‐chloropropane‐1,2‐diol (3‐MCPD) esters in fat‐based matrices is currently carried out according to a number of methods that involve either the conversion of all the esters to the free form that is then quantified (indirect methods), or the separation and quantification of the individual esters (direct methods). Indirect methods of analysis show a better sensitivity, however, the series of chemical reactions that take place during sample preparation may affect the reliability of the results because of the potential ex‐novo formation of 3‐MCPD from precursors present in the sample. This study is focused on the evaluation of the selectivity and robustness of an indirect acid‐catalysed method of 3‐MCPD esters analysis. The interference of chloride ions and glycidyl esters was evaluated. 3‐MCPD esters are overestimated only when high levels of chloride ions (>1.7 mmol/kg oil) were added to the samples. The interference by chloride ions can be easily eliminated by a single extraction step of the samples before analysis. In contrast, glycidyl esters did not interfere with the determination of 3‐MCPD esters. Further investigation on the robustness of the method showed that the time allowed for the transesterification, a major drawback of the previous version of the method, can be reduced from 16 to 4 h without any significant reduction of the accuracy and repeatability (RSD = 0.7%).
Le principe de l’anonymat du don de sperme: remarques sur son histoire et son application
Authors: Bateman S.
Published: July 2011

Introduction

Cet article, basé sur des recherches sociologiques menées sur l’activité d’insémination artificielle et de conservation de sperme, vise à répondre à quatre questions relatives à la politique actuelle d’anonymat du don du sperme: qu’est-ce que le principe d’anonymat du don de sperme ? D’où vient-il ? Quelle fonction remplit-il dans l’organisation de la pratique d’insémination artificielle avec sperme de donneur (IAD) ? Comment s’applique-t-il au quotidien ?

Matériel et méthodes

L’analyse des origines de cette politique et de son évolution repose sur des documents des années 1970 et 1980, qui permettent de reconstituer l’histoire de la pratique de l’IAD, en particulier celle menée dans le cadre des règles proposées par les Centres d’étude et de conservation du sperme (Cecos).

Résultats

Il en ressort que l’anonymat du don de sperme est une politique effective depuis au moins deux siècles, tandis que la notion d’un principe d’anonymat est relativement récente.

Conclusion

Sa remise en question aujourd’hui met à jour des interrogations persistantes sur ce qui constitue la paternité lorsque celle-ci est dissociée de l’engendrement.
Impact of running away on girls’ pregnancy
Authors: Thrane Lisa E. , Chen Xiaojin
Published: July 2011

This study assessed the impact of running away on pregnancy in the subsequent year among U.S. adolescents. We also investigated interactions between running away and sexual assault, romance, and school disengagement. Pregnancy among females between 11 and 17 years (n = 6100) was examined utilizing the Longitudinal Study of Adolescent Health (Add Health) data from Waves 1 and 2. The odds of pregnancy in the next year were 1.67 times greater for runaways net of other factors. A history of sexual assault and romantic involvement increased the likelihood of pregnancy. The relationship between pregnancy and runaway behavior in the general population is understudied. Our findings suggest that runaway youth have a multiplicity of needs that require a complex array of medical, social, emotional, and academic resources to promote positive sexual health outcomes.