bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Hydrogen Bonded Interpolymer Complexes Based on Poly (n‐butyl methacrylate–co‐methacrylic acid) and Poly (n‐butyl methacrylate ‐co‐4‐vinyl pyridine). Temperature Effect
Authors: Metref Farid , Djadoun Said
Published: June 2011

Summary: Two kinds of interpolymer complexes as soluble or precipitate of different structures were obtained in both THF and butan‐2‐one as common solvents by monitoring the hydrogen‐bonding density within homoblends of poly(n‐butyl methacrylate‐co‐4‐vinylpyridine) (BM4VP) and poly(n‐butyl methacrylate‐co‐methacrylic acid) (BMMA). A viscometry study confirmed such differences between these two types of interpolymer complexes from the behavior of the reduced viscosity of their blend solutions with feed blend composition. Qualitative and quantitative analyses of the interactions that occurred between these copolymers of relatively bulky side chain length containing various amounts of methacrylic acid and 4‐vinylpyridine were carried out by FTIR. The fraction of associated pyridine groups to the carboxylic groups of the BMMA increases as the content of these latter increases in the BMMA/BM4VP blends. The obtained results also showed that the fractions of associated pyridine within the BMMA25/BM4VP26 blends are higher than those within BMMA18/BM4VP19 or BMMA8/BM4VP10. The FTIR analysis of a selected BMMA18/BM4VP19 1:1 ratio, carried out from 80 °C to 160 °C, above the glass transition temperatures of the two constituents of the blend, confirms the presence of strong hydrogen bonding interactions between the pyridine and the carboxylic groups within these blends even at 160 °C. A LCST is expected to occur at higher temperature as shown from the progressive decrease of the fraction of the associated pyridine.
Sorption of Pollutant Traces by Nanoporous Crystalline Aerogels: Visualization by a Dye
Authors: Daniel Christophe , Bernardo Fabio
Published: June 2011

Summary: The influence of the crystalline structure on the pollutant sorption properties of high porosity syndiotactic polystyrene (sPS) aerogels has been made visible by using azulene, a blue dye, capable to form a clathrate phase with sPS. The bluish coloration observed for aerogels with the nanoporous δ‐form and the absence of coloration for aerogels with the densely‐packed γ‐form clearly establish that the crystalline nanopores play a key role for the removal of pollutant traces from water or air.
Polymer Complexes with Congruent and Incongruent Fusion by Spin Coating
Authors: Richard‐Lacroix Marie , Pellerin Christian
Published: June 2011

Summary: We demonstrate that spin coating is an efficient method for preparing pure complexes between polymers and small molecules. Samples of the α and β complexes between poly(ethylene oxide) and urea were prepared as proof‐of‐concept examples since they show congruent and incongruent fusion, respectively. Infrared spectroscopy showed that pure complex of both types could be obtained by spin coating from solutions in various solvents. The ultrafast solvent evaporation appears to be the key factor in preventing the crystallization of the small molecule. These results suggest that this simple method could be generally applicable to a wide range of systems.
Supramolecular Complex of Poly(styrene)‐b‐Poly(4‐vinylpyridine) and 1‐Pyrenebutyric Acid in Thin Film
Authors: Kuila Biplab K. , Stamm Manfred
Published: June 2011

Summary:Here, we have described a novel supramolecular complex (SMC) between poly(styrene)‐b‐poly(4‐vinylpyridine) (PS‐b‐P4VP) and 1‐pyrenebutyric acid (PBA) and studied of its self assembly in thin film. PBA will make supramolecular complex with the P4VP block due to strong hydrogen bonding between the carboxylic group of 1‐pyrenebutyric acid and pyridine ring of P4VP. The formation of supramolecular complex between PS‐P4VP and PBA through hydrogen bonding is investigated through FTIR study. The supramolecular complex of PS‐b‐P4VP and 1‐pyrenebutyric acid changed the block copolymer morphology from cylindrical to lamella in thin film due to the increase of the volume fraction of P4VP (PBA). In both cases (parent block copolymer and SMC), the microdomains are oriented normal to the substrate after annealing in a selective solvent. Pure block copolymer shows cylindrical morphology with a periodicity of ∼26 nm, whereas the SMC shows lamellar morphology with a periodicity of ∼ 29 nm. After fabricating the thin film from SMC, 1‐pyrenebutyric acid can be easily removed by dissolving the thin film in ethanol to transform the block copolymer thin film into nanotemplate or membrane.
Equilibrium Phase Diagrams of Interpenetrating Polymer Networks and Liquid Crystals
Authors: Boudraa Kamel , Bouchaour Tewfik , Maschke Ulrich
Published: June 2011

Summary: Swelling and deswelling of photochemically crosslinked interpenetrating polymer networks in anisotropic solvents were examined. Phase diagrams were established in terms of composition and temperature using two low‐molecular‐weight nematic liquid crystals, 4‐cyano‐4‐n'‐pentylbiphenyl and an eutectic mixture of cyanoparaphenylenes. Networks were formed by ultraviolet curing in the presence of a difunctional monomer and a photoinitiator. Immersion in excess of solvent allowed us to measure the solvent uptake by weight and to determine the size increase by optical microscopy in terms of temperature. We calculated weight and diameter ratios considering the swollen‐to‐dry network states of the samples.
Optical and Calorimetrical Studies of Liquid Crystalline Materials Doped with Nanoparticles
Authors: Elouali Malika , Beyens Christophe , Elouali Fatima Zohra , Yaroshchuk Oleg , Abbar Boucif , Maschke Ulrich
Published: June 2011

Summary: Electro‐optical properties of Polymer Dispersed Liquid Crystal (PDLC) films doped with different nanoparticles (NPs), as well as optical and morphological properties of liquid crystal/NP mixtures have been investigated. PDLC films were prepared by UV irradiation of thiol‐ene monomers and liquid crystal E7 in the presence of a small amount (0.5 and 1 wt.%) of nanoparticles. The presence of NP strongly influence the properties of liquid crystal/NP mixtures. In particular, adding nanoparticles results in a decrease of the glass and nematic‐isotropic transition temperatures of the LC, suggesting that strong interactions occur between LC and nanoparticles.
Characterization and subcellular localization of Tektin 3 in rat spermatozoa
Authors: Takiguchi Hiroe , Murayama Emi , Kaneko Takane , Kurio Hitoshi , Toshimori Kiyotaka , Iida Hiroshi
Published: June 2011

Mammalian sperm flagella have filament‐forming Tektin proteins (Tektin 1–5) reported to be involved in the stability and structural complexity of flagella. Male mice null for Tektin3 produce spermatozoa with reduced forward progression and increased flagellar structural bending defects. The subcellular localization of Tektin3 (TEKT3) in spermatozoa, however, has not been clarified at the ultrastructural level. To elucidate the molecular localization of TEKT3 in flagella of rat spermatozoa, we performed extraction studies followed by immunoblot analysis, immunofluorescence microscopy, and immunogold electron microscopy. Extraction of sperm flagella from the cauda epididymis resulted in complete removal of axonemal tubulins, while TEKT3 was resistant to extraction with the same S‐EDTA (1% SDS, 75 mM NaCl, 24 mM EDTA, pH 7.6) solution, suggesting that TEKT3 might be present in the peri‐axonemal component and not directly associated with axonemal tubulins. Resistance to S‐EDTA extraction might be due to disulfide bond formation during epididymal maturation since concentrations of DTT greater than 5 mM drastically promoted release of TEKT3 from flagella. Immunofluorescence microscopy and pre‐embedding immunoelectron microscopy revealed that TEKT3 was predominantly associated with the surface of mitochondria and outer dense fibers in the middle piece. In addition, TEKT3 was found to be present at the equatorial segment region of the acrosome membrane in sperm heads. TEKT3 might not only work as a flagellar constituent required for flagellar stability and sperm motility but also may be involved in acrosome‐related events, such as the acrosome reaction or sperm–egg fusion. Mol. Reprod. Dev. 78:611–620, 2011. © 2011 Wiley‐Liss, Inc.
Fast CPMG‐based Bloch‐Siegert B1+ mapping
Authors: Basse‐Lüsebrink T. C. , Sturm V. J. F. , Kampf T. , Stoll G. , Jakob P. M.
Published: June 2011

A novel method for B mapping based on the Bloch‐Siegert (BS) shift was recently presented. This method applies off‐resonant pulses before signal acquisition to encode B1 information into the signal phase. BS‐based methods possess significant advantages in measurement time and accuracy compared to magnitude‐based B methods. This study extends the idea of BS B mapping to Carr, Purcell, Meiboom, Gill (CPMG)‐based multi‐spin‐echo (BS‐CPMG‐MSE) and turbo‐spin‐echo (BS‐CPMG‐TSE) imaging. Compared to BS‐based spin echo imaging (BS‐SE), faster acquisition of the B information was possible using the BS‐CPMG‐TSE sequence. Furthermore, signal loss by T2* effects could be minimized using these spin echo‐based techniques. These effects are critical for gradient echo‐based BS methods at high field strengths. However, multi‐spin‐echo‐based BS B1 methods inherently possess high specific absorption rates. Thus, the relative specific absorption rate of BS‐CPMG‐TSE sequences was estimated and compared with the specific absorption rate produced by BS‐SE sequences. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Efficient sample density estimation by combining gridding and an optimized kernel
Authors: Zwart Nicholas R. , Johnson Kenneth O. , Pipe James G.
Published: June 2011

The reconstruction of non‐Cartesian k‐space trajectories often requires the estimation of nonuniform sampling density. Particularly for 3D, this calculation can be computationally expensive. The method proposed in this work combines an iterative algorithm previously proposed by Pipe and Menon (Magn Reson Med 1999;41:179–186) with the optimal kernel design previously proposed by Johnson and Pipe (Magn Reson Med 2009;61:439–447). The proposed method shows substantial time reductions in estimating the densities of center‐out trajectories, when compared with that of Johnson. It is demonstrated that, depending on the trajectory, the proposed method can provide reductions in execution time by factors of 12 to 85. The method is also shown to be robust in areas of high trajectory overlap, when compared with two analytical density estimation methods, producing a 10‐fold increase in accuracy in one case. Initial conditions allow the proposed method to converge in fewer iterations and are shown to be flexible in terms of the accuracy of information supplied. The proposed method is not only one of the fastest and most accurate algorithms, it is also completely generic, allowing any arbitrary trajectory to be density compensated extemporaneously. The proposed method is also simple and can be implemented on parallel computing platforms in a straightforward manner. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
The compressive electrical field electrostrictive coefficient M33 of electroactive polymer composites and its saturation versus electrical field, polymer thickness, frequency, and fillers
Authors: Guyomar D. , Cottinet P.‐J. , Lebrun L. , Putson C. , Yuse K. , Kanda M. , Nishi Y.
Published: June 2011

Electroactive polymers are widely studied because of their large electrical‐field‐induced strain. Their flexibility and their ability to be deposited on large surfaces make them promising candidates as electroactive materials for actuators or energy‐harvesting devices. For actuation purposes, the material efficiency is directly related to the electrical‐field‐related electrostrictive coefficient M33 through S33 = M33E2, where S33 is the electrical‐field‐induced strain and E is the applied electrical field. Numerous studies concern the increase of M33, but very few have been devoted to its saturations versus electrical field. To this end, the present paper describes the variation of M33 versus thickness, composition, frequency, and electrical field for polyurethane‐based composites. Based on the saturation of the electrical‐field‐induced polarization within the studied polymer composites, a model of the M33 behavior was also proposed, and it was found to show a good agreement with the experimental data. In addition, this model predicts the dielectric constant and the saturation electrical field to be the key parameters ruling the M33 saturation. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and characterization of a novel phosphorus–nitrogen‐containing flame retardant and its application for textile
Authors: Nguyen Thach‐Mien D. , Chang SeChin , Condon Brian , Uchimiya Minori , Graves Elena , Smith Jade , Easson Michael , Wakelyn Phillip
Published: June 2011

The economic and environmentally friendly flame‐retardant compound, tetramethyl (6‐chloro‐1,3,5‐triazine‐2,4‐diyl)bis(oxy)bis(methylene) diphosphonate (CN‐1), was synthesized by a simple two‐step procedure from dimethyl phosphate, and its chemical structure was characterized by 1H, 13C, and 31P nuclear magnetic resonance and gas chromatography mass spectroscopy. Using the traditional pad–dry–cure method, we obtained several different add‐ons (wt%) by treating cotton twill fabric with flame retardant (CN‐1). Thermogravimetric analysis, in an air and nitrogen atmosphere, of the modified cotton showed that decomposition occurred ~230°C with 16% residue weight char yield at 600°C, indicating high thermal stability for all treated levels. Limiting oxygen index (LOI) and the vertical flammability test were employed to determine the effectiveness of the flame‐retardant treatments on the fabrics. LOI values increased from ~18 vol% oxygen in nitrogen for untreated fabric to maximum of 34 vol% for the highest treatment level. Fabrics with higher levels of flame retardant also easily passed the vertical flammability test. Furthermore, Fourier transform infrared and scanning electron microscopy were utilized to characterize the chemical structure as well as the surface morphology of the flame‐retardant treated twill fabrics, including char area and the edge between unburned fabric and char area. Copyright © 2011 John Wiley & Sons, Ltd.
Contemporary experience with ketoconazole in patients with metastatic castration‐resistant prostate cancer: Clinical factors associated with PSA response and disease progression
Authors: Keizman Daniel , Huang Peng , Carducci Michael A. , Eisenberger Mario A.
Published: June 2011

BACKGROUND

Adrenal/intratumoral androgen biosynthesis contributes to ligand‐dependent androgen receptor activation in metastatic castration‐resistant prostate cancer (mCRCP). Compounds targeting CYP‐17 hydroxylase and lyase, as ketoconazole and abiraterone, block adrenal/intratumoral androgen biosynthesis, and are used as sequential endocrine approaches in mCRCP. We aimed to describe contemporary experience and association of clinical factors with Prostate specific antigen (PSA) response and disease progression, in mCRPC progressing on GnRH‐agonist, antiandrogen, antiandrogen withdrawal, and treated with ketoconazole.

METHODS

Data were retrospectively analyzed in all mCRPC patients treated with ketoconazole. Patients continued GnRH‐agonist, and treated with ketoconazole 200–400 mg 3× a day until dose‐limiting toxicity or disease progression. A multivariate cox regression model was used to identify clinical factors associated with PSA response and disease progression.

RESULTS

From 1999 to 2010, 114 mCRPC patients were treated with ketoconazole. With a median follow‐up time of 31 months (range 5–129), 25 patients (22%) had grade 3/4 toxicity, most commonly fatigue, abdominal discomfort, nausea, and dizziness. Sixty‐one patients (54%) had ≥50% PSA decline. Median time to progression was 8 months (range 1–129). Factors associated with PSA response and disease progression were response to prior antiandrogen (≥6 vs. <6 months), pre‐treatment PSADT (≥3 vs. <3 months) and extent of disease (limited‐axial skeleton and/or nodal vs. extensive‐appendicular skeleton and/or visceral).

CONCLUSIONS

Ketoconazole is effective and safe in mCRPC. Prior response to antiandrogen, pre‐treatment PSADT, and disease extent are associated with PSA response and disease progression, and further supports a therapeutic role in suppressing adrenal androgens in mCRPC. Prostate 72:461–467, 2012. © 2011 Wiley Periodicals, Inc.
A guide to developing and implementing safety checklists: Plant steam utilities
Authors: Fecke Mark , Martens John , Cowells Joel ,   Delmar “Trey” Morrison
Published: June 2011

Steam generation is an integral part of most chemical process plants; however, the steam plant often is or can be overlooked in the area of hazard analysis. The reasons for this oversight are obvious: steam generation is considered to be an old and well‐understood process, and steam boiler systems are often not considered to pose the same hazards as other plant units. However, modern steam boiler systems are fueled with natural gas, pulverized coal, and/or fuel oil; each of which poses significant fire and explosion hazards. For example, a moderately sized chemical plant's boiler house may have two or three boilers operating at 240 MMBTU/hr, with each using approximately 11 ton/hr of subbituminous pulverized coal feed. Chemical plants rely on equipment design and installation, maintenance practices, operating procedures, and programmable logic controllers to operate safely. Steam plants rely on these same safety mechanisms. Thus, the same process safety management objectives may be applied to these systems as to the balance of the chemical plant.

Several hazard analysis techniques can be applied to existing designs, management of change, and new designs of steam power plants in chemical facilities. A method that we have found useful to apply to these systems is that of a safety checklist based on relevant standards and good engineering practice. More than just identifying the hazards and required safeguards for such a system, if implemented effectively, the checklist will enhance training and staff knowledge of boiler operation and safety systems. This paper aims to provide guidelines for when it is appropriate to implement a checklist and for reasonable alternatives for developing such a checklist. We will also discuss typical hurdles in implementing such a hazard analysis program for existing boiler systems. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
The downside of being ‘up’: entrepreneurs' dispositional positive affect and firm performance
Authors: Baron Robert A. , Tang Jintong , Hmieleski Keith M.
Published: June 2011

Previous research indicates that dispositional positive affect (DPA) is related to many beneficial outcomes (e.g., enhanced career success, development of high‐quality social networks, improved performance on many tasks). Past research, however, has not directly investigated three crucial issues: (1) Are there limits to these beneficial effects? (2) Is dispositional positive affect related to firm performance as well as to individual entrepreneur performance? (3) Are the effects of entrepreneurs' DPA moderated by specific variables? The present study provides evidence relating to these issues. Findings indicate significant relationships between entrepreneurs' DPA and two measures of firm performance (product innovation and sales growth rate). However, there are indeed limits to these effects, such that beyond certain upper bounds, further increments in entrepreneurs' DPA are associated with declines in firm performance. These effects are moderated by firm size, such that the negative effects of entrepreneurs' DPA are stronger in small firms than in comparatively larger ones. Results contribute to the development of theory for understanding the role of entrepreneurs' affect in the entrepreneurial process. More generally, they contribute to ongoing efforts to understand how founding entrepreneurs influence the subsequent development and growth of their firms. Copyright © 2011 Strategic Management Society.
The impact of ipos on the values of directly competing incumbents
Authors: Lee Seung‐Hyun , Bach Seung B. , Baik Yoon‐Suk
Published: June 2011

Would an initial public offering (IPO) in a growing and uncertain industry have a positive or negative effect on directly competing incumbent firms in the industry? We assert that due to the risk and uncertainty inherent in a growing industry, a firm's IPO may send a positive market signal of growing industry demand. An IPO can send a signal to the investors of directly competing incumbents that the market is promising, and incumbent firms will enjoy a better future. If directly competing incumbent firms are capable of capturing these positive externalities, they will experience even greater positive results. In particular, an incumbent firm with a significant research and development investment may capture more of this increased demand in the industry. On the other hand, if a market segment is more concentrated, it is more likely that directly competing incumbents will suffer when another firm announces an IPO. We find supporting results for the various arguments of our initial question examining the computer‐related service industry. We also present discussion and implications for our results. Copyright © 2011 Strategic Management Society.
Translational characterization of [11C]GSK931145, a PET ligand for the glycine transporter type 1
Authors: Gunn Roger N. , Murthy Venkatesha , Catafau Ana M. , Searle Graham , Bullich Santiago , Slifstein Mark , Ouellet Daniele , Zamuner Stefano , Herance Raul , Salinas Cristian , Pardo‐Lozano Ricardo , Rabiner Eugenii A. , Farre Magi , Laruelle Marc
Published: June 2011

The current interest in developing Glycine transporter Type 1 (GlyT‐1) inhibitors, for diseases such as schizophrenia, has led to the demand for a GlyT‐1 PET molecular imaging tool to aid drug development and dose selection. We report on [11C]GSK931145 as a novel GlyT‐1 imaging probe in primate and man. Primate PET studies were performed to determine the level of specific binding following homologous competition with GSK931145 and the plasma‐occupancy relationship of the GlyT‐1 inhibitor GSK1018921. Human PET studies were performed to determine the test–retest reproducibility of [11C]GSK931145 and the plasma‐occupancy relationship of GSK1018921. [11C]GSK931145 entered primate and human brain and yielded a heterogeneous pattern of uptake which was similar in both species with highest uptake in midbrain, thalamus, and cerebellum. Homologous competition in primates indicated no viable reference region and gave binding potential estimates between 1.5 and 3 for midbrain, thalamus and cerebellum, While the distribution and binding potential values were similar across species, both the plasma free fraction (fP: 0.8 vs. 8%) and delivery (K1: 0.025 vs. 0.126 ml cm−3 min−1) were significantly lower in humans. Test–retest reproducibility in humans calculated using a two tissue compartmental model was poor (VAR(VT): 29–38%), but was improved using a pseudo reference tissue model (VAR(BPND): 16–23%). GSK1018921 EC50 estimates were 22.5 and 45.7 ng/ml in primates and humans, respectively. Synapse, 2011. © 2011 Wiley‐Liss, Inc.
Cut Set Analysis using Behavior Trees and model checking
Authors: Lindsay Peter A. , Yatapanage Nisansala , Winter Kirsten
Published: June 2011

Safety analysis can be labour intensive and error prone for system designers. Moreover, even a relatively minor change to a system’s design can necessitate a complete reworking of the system safety analysis. This paper proposes the use of Behavior Trees and model checking to automate Cut Set Analysis (CSA) : that is, the identification of combinations of component failures that can lead to hazardous system failures. We demonstrate an automated incremental approach to CSA, in which models are extended incrementally and previous results incorporated in such a way as to significantly reduce the time and effort required for the new analysis. The approach is demonstrated on a case study concerning the hydraulics systems for the Airbus A320 aircraft.
Reduction of photosynthesis before midday depression occurred: leaf photosynthesis of Fagus crenata in a temperate forest in relation to canopy position and a number of days after rainfall
Authors: Koyama Kohei , Kikuzawa Kihachiro
Published: June 2011

We investigated an effect of canopy position and a number of days after rainfall on reduction of photosynthetic rate in a Fagus crenata forest in summer 2008, during days when midday depression was not apparent. We compared in situ photosynthetic rate and photosynthetic rate that was calculated by photosynthetic light response curves measured in the morning. The ratio, in situ photosynthesis divided by the curve‐estimated value, declined towards the end of each day for the upper leaves, but not for the lower leaves. Total photosynthesis was reduced only for the upper leaves by 12% during 5 days after the rainfall.
Direct Determination of Glycidyl Esters of Fatty Acids in Vegetable Oils by LC–MS
Authors: Blumhorst Michael R. , Venkitasubramanian Padmesh , Collison Mark W.
Published: June 2011

An LC–MS method using a single quadrupole mass spectrometer was developed for direct analysis of glycidyl esters of fatty acids in vegetable oils. Without any sample clean‐up, this method provided acceptable recovery of seven glycidyl esters, comparable results to a previously‐published method utilizing two solid‐phase extraction steps, and consistent detection parameters after greater than 200 injections without any cleaning operations performed. This method could readily be implemented as a screening assay for glycidyl esters in most oil laboratories.
Histological and biological assessment of vitrified ovarian follicles from large animals
Authors: Bao Rong‐Mei , Taketsuru Hiroaki , Miyano Takashi
Published: June 2011

Mammalian ovaries contain mixed populations of follicles at different developmental stages. A combination of vitrification and growth culture of ovarian follicles could provide the desired number of mature eggs from a preserved small amount of ovarian tissues. Secondary and primordial follicles from porcine and bovine ovaries were vitrified in solutions containing ethylene glycol, dimethyl sulfoxide and different concentrations of sucrose, and assessed via histological examination, viability staining, xenografting to immunodeficient mice, and in vitro culturing. Histological examination revealed the damage to oocytes and the damage to follicle components separately. The effects of sucrose in vitrification solutions on the follicles were different depending on the developmental stage of the follicle, oocyte size, cell type in the follicle, and species. Viability staining with fluorescein diacetate was useful to assess the damage to oocytes in secondary follicles. In the xenografts, vitrified bovine primordial and secondary follicles developed to the antral stage, and vitrified porcine primordial follicles developed to the secondary stage. Furthermore, bovine secondary follicles formed antrum‐like structures in culture. These results suggest that histological examination and viability staining are valuable for assessing the direct effects of vitrification and warming conditions on follicles and oocytes, while xenografting and in vitro culturing can be useful for evaluating the developmental ability of vitrified follicles and oocytes.
Oocyte growth in vitro: potential model for studies of oocyte–granulosa cell interactions
Authors: Hirao Yuji
Published: June 2011

Various factors such as gonadotrophins, growth factors, and steroid hormones play important roles in the regulation of oocyte/follicular growth in mammalian ovaries. In addition to these factors, there is a bidirectional interaction between oocytes and granulosa cells that is essential for achieving optimal oocyte developmental competence. Oocytes play a key role in this interaction by secreting paracrine factors that alter the activities of neighboring cumulus cells, such as the expression of a specific amino acid transporter, cholesterol biosynthesis, and levels of glycolysis in the cumulus cells. Among the known oocyte‐derived factors, growth differentiation factor 9 (GDF9) is the dominant factor mediating the regulation by oocytes leading to cumulus expansion and granulosa cell proliferation. GDF9 frequently interacts with other oocyte‐derived factors in a synergistic manner. It seems reasonable to speculate that oocytes growing in vitro require interactions similar to those in vivo. Some of the oocyte‐mediated regulations have been confirmed in vitro, providing evidence of the usefulness of culture systems as a strong tool for such studies. This review discusses in vitro culture of growing oocytes in terms of oocyte–granulosa cell interactions.
Packet level video quality evaluation of extensive H.264/AVC and SVC transmission simulation
Authors: Skupin Robert , Hellge Cornelius , Schierl Thomas , Wiegand Thomas
Published: June 2011

Video transmission over error prone channels as present in most of today’s communication channels, such as Mobile TV or some IPTV systems, is constantly subject to research. Simulation is an important instrument to evaluate performance of the overall video transmission system, but the multitude of parameters often requires large and time-consuming simulation sets. In this paper, we present a packet level mechanism for fast evaluation of error-prone H.264/AVC and SVC video transmission with application layer video quality metrics, such as PSNR. Our approach significantly reduces the overall simulation time by eliminating redundancy in the evaluation phase and utilizing the prediction structure of the video codec. The benefit of the presented packet level video quality evaluation is evaluated with an exemplary simulation setup of an IPTV service with link congestion.
From service delivery to integrated SOA based application delivery in the telecommunication industry
Authors: Menkens Christian , Wuertinger Michael
Published: June 2011

Currently, in the Telecommunication industry, the move toward service oriented infrastructures based on Internet Protocol (IP), IP Multimedia Subsystem (IMS), Service Oriented Architectures (SOA), and Service Delivery Platforms (SDP) can be observed. Communication Service Providers (CSP) are opening parts of their core infrastructure and interfaces to third party developers. Nevertheless, there is still a gap between application developer communities and the Telecommunication industry. CSPs offer their services so developers can use them in their applications but developers do not have any incentives, tools, or development environments that would help them to overcome the barriers of accessing Telecommunication services to build future distributed Web-Telecom-Converged Applications. This research work presents a concept for how to close this gap by conceptualizing an end-to-end platform from Telecommunication core networks and the Internet to end user clients. Requirements of all platform stakeholders are identified and through the combination of SOA platform concepts with Telecommunication SDP architecture concepts and application store application distribution concepts (e.g. Apple AppStore, Google Market) fulfilled. The final result is a concept and logical reference architecture for Application Delivery Platforms (ADP) that extend the concepts of SDPs by broadening the focus from re-usable SOA services over a Web-Telecom-Converged Application architecture and service/application life cycle management to end user applications on client platforms and devices. In order to proof the concepts of the logical ADP reference architecture, central parts of the architecture and a demonstrational “Converged Address Book” use-case are implemented and deployed.
The role of infant feeding practices in the explanation for ethnic differences in infant growth: the Amsterdam Born Children and their Development study
Authors: de Hoog Marieke L. A. , van Eijsden Manon , Stronks Karien , Gemke Reinoud J. B. J. , Vrijkotte Tanja G. M.
Published: June 2011

Rapid early growth in infants may influence overweight and CVD in later life. Both rapid growth and these disease outcomes disproportionately affect some ethnic minorities. We determined ethnic differences in growth rate (Δ standard deviation scores, ΔSDS) during the first 6 months of life and assessed the explanatory role of infant feeding. Data were derived from a multiethnic cohort for the Amsterdam Born Children and their Development study (The Netherlands). Growth data (weight and length) of 2998 term-born singleton infants with no fetal growth restriction were available for five ethnic populations: Dutch (n 1619), African descent (n 174), Turkish (n 167), Moroccan (n 232) and other non-Dutch (n 806). ΔSDS for weight, length and weight-for-length between 4 weeks and 6 months were defined using internal references. Infant feeding pattern (breast-feeding duration, introduction of formula feeding and complementary feeding) in relation to ethnic differences in growth rate was examined by multivariate linear regression. Results showed that the growth rate was higher in almost all ethnic minorities, with β between 0·07 and 0·41 for ΔSDS weight and between 0·12 and 0·42 for ΔSDS length, compared with ethnic Dutch infants. ΔSDS weight-for-length was similar across groups, except for Moroccan infants (β 0·25, P < 0·05) after correction for confounders. In general, exclusive breast-feeding for 4 months was associated with slower growth for all three growth measures. Feeding factors explained, to a small degree, the higher weight and length gain in African descent infants, but not the higher ΔSDS weight-for-length in the Moroccan population. More research is needed to elucidate the underlying mechanisms of the high infant growth rate in Turkish and Moroccan infants.
Towards a new role for vector systematics in parasite control
Authors: ZAROWIECKI MAGDALENA , LOAIZA JOSE R. , CONN JAN E.
Published: June 2011

Vector systematics research is being transformed by the recent development of theoretical, experimental and analytical methods, as well as conceptual insights into speciation and reconstruction of evolutionary history. We review this progress using examples from the mosquito genusAnopheles. The conclusion is that recent progress, particularly in the development of better tools for understanding evolutionary history, makes systematics much more informative for vector control purposes, and has increasing potential to inform and improve targeted vector control programmes.
The development of whole-word representations in compound word processing: Evidence from eye fixation patterns of elementary school children
Authors: HÄIKIÖ TUOMO , BERTRAM RAYMOND , HYÖNÄ JUKKA
Published: June 2011

The role of morphology in reading development was examined by measuring participants’ eye movements while they read sentences containing either a hyphenated (e.g., ulko-ovi “front door”) or concatenated (e.g., autopeli “racing game”) compound. The participants were Finnish second, fourth, and sixth graders (aged 8, 10, and 12 years, respectively). Fast second graders and all four and sixth graders read concatenated compounds faster than hyphenated compounds. This suggests that they resort to slower morpheme-based processing for hyphenated compounds but prefer to process concatenated compounds via whole-word representations. In contrast, slow second graders’ fixation durations were shorter for hyphenated than concatenated compounds. This implies that they process all compounds via constituent morphemes and that hyphenation comes to aid in this process.
An Improvement of the Lovász Local Lemma via Cluster Expansion
Authors: BISSACOT RODRIGO , FERNÁNDEZ ROBERTO , PROCACCI ALDO , SCOPPOLA BENEDETTO
Published: June 2011

An old result by Shearer relates the Lovász local lemma with the independent set polynomial on graphs, and consequently, as observed by Scott and Sokal, with the partition function of the hard-core lattice gas on graphs. We use this connection and a recent result on the analyticity of the logarithm of the partition function of the abstract polymer gas to get an improved version of the Lovász local lemma. As an application we obtain tighter bounds on conditions for the existence of Latin transversal matrices.
‘How, or Why, do we Come to Think of a World of Things in Themselves?’
Authors: Kuehn Manfred
Published: June 2011

The interpretation of Kant's Critical philosophy as a version of traditional idealism has a long history. In spite of Kant's and his commentators’ various attempts to distinguish between traditional and transcendental idealism, his philosophy continues to be construed as committed (whether explicitly or implicitly and whether consistently or inconsistently) to various features usually associated with the traditional idealist project. As a result, most often, the accusation is that his Critical philosophy makes too strong metaphysical and epistemological claims.

In his The Revolutionary Kant, Graham Bird engages in a systematic and thorough evaluation of the traditionalist interpretation, as part of perhaps the most comprehensive and compelling defence of a revolutionary reading of Kant's thought. In the third part of this special issue, the exchanges between, on the one hand, Graham Bird and, on the other, Gary Banham, Gordon Brittan, Manfred Kuehn, Adrian Moore and Kenneth Westphal focus on specific aspects of Bird's interpretation of Kant's first Critique. More exactly, the emphasis is on specific aspects of Bird's interpretation of the Introduction, Analytic of Principles and Transcendental Dialectic of Kant's first Critique.

The second part of the special issue is devoted to discussions of particular topics in Bird's construal of the remaining significant parts of the first Critique, namely, of the Transcendental Aesthetic and the Analytic of Concepts. Written by Sorin Baiasu and Michelle Grier, these articles examine specific issues in these two remaining parts of the Critique, from the perspective of the debate between the traditionalist and revolutionary interpretation. The special issue begins with an Introduction by the guest co-editors. This provides a summary of the exchanges between Bird and his critics, with a particular focus on the debates stemming from the differences between traditional and revolutionary interpretations of Kant.
Surface roughness of MgO thin film and its critical thickness for optimal biaxial texturing by ion-beam-assisted deposition
Authors: Miyata S. , Ibi A. , Izumi T. , Shiohara Y.
Published: June 2011

We investigated the deposition time dependences of the in-plane grain alignment (Δφ) and the surface roughness (w) of biaxially textured MgO thin films fabricated by ion-beam-assisted deposition (IBAD) and found a strong correlation between them. The time evolution of the surface roughness of IBAD-MgO showed an abrupt increase at the same time corresponding to the beginning of the deterioration in Δφ. The roughness versus thickness profiles obtained under different deposition conditions with different assisting ion-beam currents collapsed to a single curve, even though the deposition rates were significantly different in each condition. This implies that the abrupt increase in roughness occurred at the same thickness—of about 4 nm—irrespective of the deposition rate. The result also indicated that the Δφ deterioration began with the same thickness of about 4 nm. This “critical” thickness of about 4 nm might be related to the completion of the crystallization of the film. Further, deposition beyond the critical thickness, therefore, became merely a homoepitaxial deposition under the “IBAD” condition, which was far from optimal because of the ion bombardment and low temperature (no-heating), and thus Δφ deteriorated. Based on these considerations, we propose an approach to attain a sharp texture in a IBAD-MgO-based biaxial substrate; moreover, we demonstrated this approach using a two-step deposition process.
A continuum model of colloid-stabilized interfaces
Authors: Aland Sebastian , Lowengrub John , Voigt Axel
Published: June 2011

Colloids that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. Examples include bicontinuous interfacially jammed emulsion gels (bijels), which were proposed in this study by Stratford et al. [Science 309, 2198 (2005)] as a hypothetical new class of soft materials in which interpenetrating, continuous domains of two immiscible viscous fluids are maintained in a rigid state by a jammed layer of colloidal particles at their interface. We develop a continuum model for such a system that is capable of simulating the long-time evolution. A Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase flow system is combined with a surface phase-field-crystal model for the microscopic colloidal system along the interface. The presence of colloids introduces elastic forces at the interface between the two immiscible fluid phases. An adaptive finite element method is used to solve the model numerically. Using a variety of flow configurations in two dimensions, we demonstrate that as colloids jam on the interface and the interface crystallizes, the elastic force may be strong enough to make the interface sufficiently rigid to resist external forces, such as an applied shear flow, as well as surface tension induced coarsening in bicontinuous structures.
Planar-defect characteristics and cross-sections of 〈001〉, 〈111〉, and 〈112〉 InAs nanowires
Authors: Li Zi-An , Möller Christina , Migunov Vadim , Spasova Marina , Farle Michael , Lysov Andrey , Gutsche Christoph , Regolin Ingo , Prost Werner , Tegude Franz-Josef , Ercius Peter
Published: June 2011

We report on detailed structural and morphological characterizations of InAs nanowires of 〈001〉, 〈111〉, and 〈112〉 crystallographic directions grown on (001)B InAs wafer substrates using high-resolution transmission electron microscopy. We find that 〈001〉-oriented InAs nanowires are cubic zincblende-type structure and free of planar defects. The 〈111〉- and 〈112〉-oriented InAs nanowires both have densely twinned (111) planar defects that are perpendicular and parallel to the growth direction, respectively. The cross sections of all three types of InAs nanowires are obtained from 3D reconstructions using electron tomography. The characteristics of the planar defects and the 3D wire shape should provide better estimations of microstructure-relevant physical properties, such as conductivity and Young’s modulus of InAs nanowires.
The potential comb improves the efficiency of low-frequency energy harvesting
Authors: Gendelman B. , Gendelman O. , Pogreb R. , Bormashenko E.
Published: June 2011

This paper introduces a nonlinear resonant magneto-elastic device with 2 degrees of freedom that can serve as a mechanical frequency multiplier effective for energy harvesting. The device allows energy harvesting at low and extra-low exciting frequencies. The concept of effective frequency multiplication is proposed. The frequency multiplication factor may vary in the range from 2 up to several dozens. The theoretical model, the results of the experiment, and a computer simulation are presented. With a frequency of 3.5 Hz and an amplitude of 12.5 mm of shaker oscillations, the experimental setup produces output oscillations that have the principal harmonic of the amplitude 3.55 mm at 14 Hz. The amplitude of the output acceleration is 27 m/s2, which is 4.5 times the initial acceleration provided by the shaker. The numerical simulation of the setup with different elastic coefficients yields a frequency multiplication factor of 14, and the amplitude of output acceleration is equal to 35 to 60 m/s2. The operating principle used in the device is supposed to be useful as a principle of inexpensively transforming the mechanical energy with frequency-upconversion.
Nano-engineered defect structures in Ce- and Ho-doped metal-organic chemical vapor deposited YBa2Cu3O6+δ films: Correlation of structure and chemistry with flux pinning performance
Authors: Aytug T. , Chen Z. , Maroni V. A. , Miller D. J. , Cantoni C. , Specht E. D. , Kropf A. J. , Zaluzec N. , Zhang Y. , Zuev Y. , Paranthaman M.
Published: June 2011

This study reports on the fabrication of metal-organic chemical vapor deposited (MOCVD) YBa2Cu3O6+δ (YBCO) films doped with varying amounts of Ce and Ho and the characterization of their electrical, microstructural, and chemical properties. The films are prepared by vapor phase deposition of a Y-Ba-Cu precursor mix containing controlled amounts of Ce and Ho onto buffered metal strip templates. The comprehensive characterization of these films by critical current measurement, transmission electron microscopy, x-ray diffraction, Raman microspectroscopy, and x-ray absorption spectroscopy provides detailed information about the structure/chemistry/performance relationships and how they vary with varying amounts of Ce and Ho in the YBCO films. The microstructure exhibited by both the Ce-doped and the Ho-doped films contains a high density of crystal basal-plane aligned, fluoritelike precipitates within the YBCO matrix. For optimally doped samples, the influence of these nanocrystalline phases on the flux pinning properties manifests itself as a significant improvement in the critical current density (Jc) for magnetic field orientations that approach being parallel to the ab planes of the YBCO, while no appreciable change is observed in either self-field Jc or applied-field Jc performance in the vicinity of field orientations parallel to the YBCO c-axis. The Ce is almost exclusively concentrated in the fluoritelike nanoprecipitates, while the Ho incorporates into both the planar arrays of nanoprecipitates and the superconducting matrix, where it substitutes for Y in the YBCO lattice. The present findings for Ce and Ho doping are in interesting contrast with our prior findings for Zr-doped MOCVD films due to the fact that the Zr-doped films exhibit columnar precipitate arrays that produce a substantial improvement in Jc for magnetic field orientations parallel to the YBCO c-axis, while no appreciable change is observed in either self-field or applied-field Jc performance for field orientations parallel to the ab planes. These results suggest that improvement of the in-field Jc of YBCO films over an extended range of field angles could be achieved by doping strategies that simultaneously produce both ab-plane aligned and c-axis aligned precipitate arrays.
Plasmon-enhanced low-intensity laser switching of gold::vanadium dioxide nanocomposites
Authors: Ferrara D. W. , MacQuarrie E. R. , Nag J. , Kaye A. B. , Haglund R. F.
Published: June 2011

Transient absorption of gold nanoparticle (NP) arrays covered by a 60 nm thick film of VO2 was measured using a mechanically shuttered 785 nm pump laser and a 1550 nm cw probe. Even though the Au NPs constitute only 4% by volume of the nanocomposite, they increase the effective absorption coefficient by a factor of 1.5 and reduce the threshold laser power required to induce the semiconductor-to-metal transition (SMT) by as much as 37%. It is argued that the NPs function as thermal initiators for the SMT and as “nanoradiators” to increase the scattering and absorption of light into interband transitions of the VO2.