bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntheses, characterization, and properties of multiblock copolymers consisting of polyisobutylene and poly(L‐lactide) segments
Authors: Ojha Umaprasana , Kulkarni Pallavi , Singh Jagdeep , Faust Rudolf
Published: June 2009

The syntheses of {‐poly(L‐lactide) (PLLA)‐b‐polyisobutylene (PIB)‐}n multiblock copolymers were accomplished for the first time by chain extension of PLLA‐b‐PIB‐b‐PLLA triblock copolymers. Well‐defined PLLA‐b‐PIB‐b‐PLLA triblock copolymers with predictable Mns, low PDIs (1.10–1.18) and excellent blocking efficiencies were prepared by anionic ring‐opening polymerizations of L‐lactide initiated with hydroxyallyl telechelic PIB (HO‐Allyl‐PIB‐Allyl‐OH) in toluene at 110 °C. The triblock copolymers were successfully chain extended with 4,4′‐methylenebis(phenylisocyanate) (MDI) to obtain the multiblock copolymers with good gravimetric yields of ∼86 to 96%. The chain‐extended polymers were soluble in a range of common organic solvents. The block copolymers showed two glass transition temperatures in differential scanning calorimetric analysis for the PIB and PLLA blocks indicating microphase separation, which was supported by atomic force microscopy images. The as‐synthesized compression molded multiblock copolymers exhibited tensile strengths in the range of 8–24 MPa with elongations at break in the range of 2.5–400%. The static and dynamic mechanical properties showed a strong dependence on the relative PLLA content in the copolymer. The dynamic mechanical analysis also indicated microphase separation at higher PLLA compositions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3490–3505, 2009
Synthesis and properties of conjugated polymers containing 3,9‐ and 2,9‐linked carbazole units in the main chain
Authors: Tamura Kosaku , Shiotsuki Masashi , Kobayashi Norihisa , Masuda Toshio , Sanda Fumio
Published: June 2009

Novel conjugated polymers containing 3,9‐ or 2,9‐linked carbazole units in the main chain were synthesized by the polycondensation of ethynyl‐ and iodo‐substituted 9‐arylenecarbazolylene monomers, and their optical and electrical properties were studied. Polymers with weight‐average molecular weights of 3400–12,000 were obtained in 76–99% yields by the Sonogashira coupling polycondensation in piperidine or tetrahydrofuran (THF)/piperidine at 30 °C for 48 h. All the 3,9‐linked polymers absorbed light around 300 nm. The para‐phenylene‐linked polymer also absorbed light around 350 nm, while meta‐phenylene‐linked one did not. The 3,9‐linked polymers absorbed light at a wavelength longer than the 2,9‐linked one. The polymers emitted blue fluorescence with high quantum yields (0.21–0.78) upon excitation at the absorption maxima. The polymers were oxidized around 0.6 V, and reduced around 0.5 V. Poly(1) showed the dark conductivity of 3.7 × 10−11 S/cm (103 V/cm). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3506–3517, 2009
Supramacromolecular self‐assembly: Chain extension, star and block polymers via pseudorotaxane formation from well‐defined end‐functionalized polymers
Authors: Gibson Harry W. , Farcas Aurica , Jones Jason W. , Ge Zhongxin , Huang Feihe , Vergne Matthew , Hercules David M.
Published: June 2009

Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended to “dimeric” 8 by pseudorotaxane formation with a ditopic guest, α,ω‐bis[p‐(N‐benzylammoniomethyl)phenoxy]heptane bis(hexafluorophosphate) (7). The three‐armed star polymer 11 was similarly formed by complexation of the dibenzo‐24‐crown‐8‐terminated polystyrene (5) with a tritopic secondary ammonium salt, 1,3,5‐tris[p‐(benzylammoniomethyl)phenyl]benzene tris(hexafluorophosphate) (10). Another three‐armed star polymer 13 was self‐assembled from dibenzo‐24‐crown‐8‐terminated polystyrene (5) and a tetratopic paraquat compound, 1,2,4,5‐tetrakis{p‐N‐[(N′‐methyl‐4,4′‐bipyridinium)methylphenyl]}benzene octakis(hexafluorophosphate) (12). The above chain extension and star polymer formation processes seemed to be cooperative; that is, the second and third complexation steps proceed with stepwise higher efficiencies than statistically expected. Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended with secondary ammonium terminated polystyrene 14, forming 16, and also self‐assembled with a secondary ammonium ion terminated polyisoprene 15 to form supramolecular block copolymer 17. These processes were examined by NMR, mass spectrometry and viscometery. Thus, although binding in these systems is not particularly strong (association constants <104 M−1), these examples provide proof‐of‐principle that pseudorotaxane formation is a viable concept for chain extension and self‐assembly of novel types of block copolymers and star polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3518–3543, 2009
Sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions as a route to well‐defined mono and bis end‐functionalized poly(N‐isopropylacrylamide)
Authors: Yu Bing , Chan Justin W. , Hoyle Charles E. , Lowe Andrew B.
Published: June 2009

Sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions have been used as a facile and quantitative method for modifying end‐groups on an N‐isopropylacrylamide (NIPAm) homopolymer. A well‐defined precursor of polyNIPAm (PNIPAm) was prepared via reversible addition‐fragmentation chain transfer (RAFT) polymerization in DMF at 70 °C using the 1‐cyano‐1‐methylethyl dithiobenzoate/2,2′‐azobis(2‐methylpropionitrile) chain transfer agent/initiator combination yielding a homopolymer with an absolute molecular weight of 5880 and polydispersity index of 1.18. The dithiobenzoate end‐groups were modified in a one‐pot process via primary amine cleavage followed by phosphine‐mediated nucleophilic thiol‐ene click reactions with either allyl methacrylate or propargyl acrylate yielding ene and yne terminal PNIPAm homopolymers quantitatively. The ene and yne groups were then modified, quantitatively as determined by 1H NMR spectroscopy, via radical thiol‐ene and radical thiol‐yne reactions with three representative commercially available thiols yielding the mono and bis end functional NIPAm homopolymers. This is the first time such sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions have been used in polymer synthesis/end‐group modification. The lower critical solution temperatures (LCST) were then determined for all PNIPAm homopolymers using a combination of optical measurements and dynamic light scattering. It is shown that the LCST varies depending on the chemical nature of the end‐groups with measured values lying in the range 26–35 °C. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3544–3557, 2009
Ethylene polymerization and ethylene/hexene copolymerization with vanadium(III) catalysts bearing heteroatom‐containing salicylaldiminato ligands
Authors: Wu Ji‐Qian , Pan Li , Liu San‐Rong , He Li‐Peng , Li Yue‐Sheng
Published: June 2009

A series of novel vanadium(III) complexes bearing heteroatom‐containing group‐substituted salicylaldiminato ligands [RNCH(ArO)]VCl2(THF)2 (Ar = C6H4, R = C3H2NS, 2a; C7H4NS, 2c; C7H5N2, 2d; Ar = C6H2tBu2 (2,4), R = C3H2NS, 2b) have been synthesized and characterized. Structure of complex 2c was further confirmed by X‐ray crystallographic analysis. The complexes were investigated as the catalysts for ethylene polymerization in the presence of Et2AlCl. Complexes 2a–d exhibited high catalytic activities (up to 22.8 kg polyethylene/mmolV h bar), and affording polymer with unimodal molecular weight distributions at 25–70 °C in the first 5‐min polymerization, whereas produced bimodal molecular weight distribution polymers at 70 °C when polymerization time prolonged to 30 min. The catalyst structure plays an important role in controlling the molecular weight and molecular weight distribution of the resultant polymers produced in 30 min polymerization. In addition, ethylene/hexene copolymerizations with catalysts 2a–d were also explored in the presence of Et2AlCl, which leads to the high molecular weight and unimodal distributions copolymers with high comonomer incorporation. Catalytic activity, comonomer incorporation, and polymer molecular weight can be controlled over a wide range by the variation of catalyst structure and the reaction parameters, such as comonomer feed concentration, polymerization time, and polymerization reaction temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3573–3582, 2009
The potential use of spirometry during methacholine challenge test in young children with respiratory symptoms
Authors: Vilozni Daphna , Livnat Galit , Dabbah Husein , Elias Nael , Hakim Fahed , Bentur Lea
Published: June 2009

Background

The concentration of methacholine that causes a fall of 20% from baseline forced expiratory volume in the first second (PC20‐FEV1) in the methacholine challenge test (MCT) is not usually considered a diagnostic tool in preschool children since PC20‐FEV1 may not be achievable <6 years of age.

Aim

To assess the usefulness of various spirometry indices obtained during MCT in a large group of 3‐ to 6‐year‐old children with respect to their clinical diagnosis.

Methods

Standardized MCT (inhaled triple‐concentration increments [0.057–13.925 mg] of methacholine solution) was performed by 84 children previously diagnosed with asthma (asthmatics) and 48 with prolonged cough (coughers). Spirometry was determined at baseline and between inhalations; PC20‐FEV1 and PC25‐FEV0.5 were calculated.

Results

PC20‐FEV1 values were significantly less in the asthmatics than in the coughers (mean ± SD was 3.21 ± 4.32 vs. 22.35 ± 3.66 ml/mg). Similarly, PC25‐FEV0.5 was 1.48 ± 3.08 in the asthmatics and 9.45 ± 12.59 mg/ml/Mch in the coughers, P < 0.0001. A cut‐off at 4.0 mg/ml for PC20‐FEV1 had 77.4% sensitivity and 75.0% specificity, a cut‐off at 2.2 mg/ml for PC25‐FEV0.5 had 73.8% sensitivity and 72.9% specificity, for clinical diagnosis of asthma. PC25‐FEV0.5 also showed a correlation with age.

Conclusions

Our findings suggest that MCT can be performed in preschool children with various respiratory symptoms. PC25‐FEV0.5 may be a better end‐point parameter. Children with a clinical diagnosis of asthma respond to a lower MCT concentration than children with cough. Further studies are needed to determine airway responsiveness in healthy young children and to further assess the contribution of MCT to the clinical diagnosis in this age group. Pediatr Pulmonol. 2009; 44:720–727. © 2009 Wiley‐Liss, Inc.
Mannitol and exercise challenge tests in asthmatic children
Authors: Kersten Elin T.G. , Driessen Jean M.M. , van der Berg Julianne D. , Thio Bernard J.
Published: June 2009

Background

Bronchial hyperresponsiveness (BHR), a characteristic feature of asthma, can be assessed through standardized bronchial provocation tests (BPT). Exercise as a BPT is used in diagnosing and monitoring exercise induced bronchoconstriction (EIB). Recently a novel osmotic BPT has been developed, using dry powder mannitol. The aim of this study was to investigate the clinical utility of the mannitol challenge to identify asthmatic children with EIB.

Materials and Methods

Thirty‐three clinically stable children, aged 9–18 years, with a history of EIB, performed both mannitol and exercise provocation challenges. Data were composed of a cross tabulation comparing the reaction on exercise provocation challenge to mannitol challenge. Correlations between post‐exercise fall in FEV1 and response–dose ratio (RDR) and PD15 of mannitol were calculated.

Results

Twenty‐five children completed both tests. Pearson's correlation between log‐transformed RDR for mannitol and post‐exercise fall in FEV1 was rp = 0.666 (P < 0.001). There was no significant relationship between the log PD15 of mannitol and post‐exercise fall in FEV1. Children on long acting bronchodilator agents (LABA) were significantly (P < 0.05) more likely to have a positive response on the mannitol challenge. Positive and negative predictive values of the mannitol challenge for EIB were 69% and 91%.

Conclusion

Mannitol challenge appears to be a suitable alternative for an exercise provocation test to assess EIB in asthmatic children. Given the negative predictive value of 91%, it is especially useful to exclude EIB. Pediatr Pulmonol. 2009; 44:655–661. © 2009 Wiley‐Liss, Inc.
Decreased risk for atopic disorder associated with highly hyperreactive tuberculin skin test reaction in children and adolescents
Authors: Marija Maćešić , Mirjana Turkalj , Žaneta Jelčić , Slavica Dodig , Branka Kristić‐Kirin , Boro Nogalo , Davor Plavec
Published: June 2009

Background

It is speculated that the exposure to Mycobacterium tuberculosis, either by infection or by Bacillus Calmette‐Guérin vaccination, may inhibit the onset of atopy by the modification of immune profiles leading to a shift of TH1/TH2 balance to the TH1 side.

Objective

One hundred eighty‐six patients hyperreactive at tuberculin skin test (TST) were examined in order to investigate the prevalence of atopic disorder, particularly referring to the association between the size of the TST induration and the prevalence of sensitization and manifest atopic disorder.

Methods

The study consisted of a family history record, patients' medical history assessment and clinical examination, skin prick test (SPT), serum total and allergen‐specific IgE (sIgE) measurement and eosinophil count.

Results

Atopic disorder was present in 49 (26.3%) patients tested. No significant difference between the groups based on the TST induration size (15–24 mm vs. ≥25 mm) was found for gender distribution, family atopy history, total IgE measurement, eosinophil count, positive SPT, and the presence of sIgE. A significant difference was found for the age median (14.0 years vs. 13.0 years), childhood atopy record, and manifest atopic disorder. No association between the size of the TST induration and the incidence of allergic sensitization was demonstrated. However, a significant inverse association between the size of the TST induration and manifest atopic disorder was demonstrated.

Conclusion

In patients highly hyperreactive at TST, the size of the induration is inversely associated with manifest atopic disorder. Pediatr Pulmonol. 2009; 44:701–705. © 2009 Wiley‐Liss, Inc.
High flow nasal cannula therapy as respiratory support in the preterm infant
Authors: Dani Carlo , Pratesi Simone , Migliori Claudio , Bertini Giovanna
Published: June 2009

We reviewed the literature on the effects of high flow nasal cannula (HFNC) and heated, humidified, high‐flow, nasal cannula (HHHFNC) treatment in preterm infants. We found nine studies, but only two were randomized controlled trials. These studies show that: HFNC application is associated to the delivery of continuous distending pressure (CDP) in patients with closed mouth, whose value is proportional to the delivered flow only in smaller infants; the CDP delivered by HFNC is unpredictable and present large inter‐patient and intra‐patient variability; the use of recently available HHHFNC devices is effective in minimizing nasal mucosa injuries compared to traditional HFNC; the effectiveness of HHHFNC versus NCPAP for the treatment of apnoea of prematurity, respiratory distress syndrome, and the prevention of extubation failure, has been poor investigated and firm conclusions cannot be drawn on this matter. In conclusion, on the basis of published data, the routinary application of HFNC should be limited to patients requiring oxygen‐therapy, HHHFNC devices should be preferred to HFNC, but their employment as an alternative to NCPAP should wait for the conclusion of randomized controlled trials. Pediatr Pulmonol. 2009; 44:629–634. © 2009 Wiley‐Liss, Inc.
Trace Detection of Explosives Vapours by Molecularly Imprinted Polymers for Security Measures
Authors: Bunte Gudrun , Heil Moritz , Röseling Dirk , Hürttlen Jürgen , Pontius Heike , Krause Horst
Published: June 2009

In view of the recent terror acts for example against aviation or underground transportation systems, it is obvious that the detection techniques used today for explosives are inadequate and have to be improved. In concern with national security there is need for inexpensive, rapid, highly sensitive and selective sensors. In this respect, mass‐sensitive devices coated with substance specific molecularly imprinted polymers (MIPs) look promising to achieve low‐cost detection devices capable of detecting gaseous explosives traces fast, sensitively and reliably. Preliminary results and possible concepts for MIP‐based low‐cost sensors are presented in this paper.
A Look Behind Electrochemical Detection of Explosives
Authors: Rabenecker Peter , Pinkwart Karsten
Published: June 2009

Few years ago, the Fraunhofer Institute for Chemical Technology started researching the detection of the explosive TNT (2,4,6‐trinitrotoluene) in contaminated soil. This research resulted in a European patent and a sensor prototype. After successful transfer of the developed detection technology from the solid to the gaseous phase, nearly 20 additional explosives were researched. Most of these explosives were nitroaromatic compounds, but in the last few years some work has also been done with peroxide explosives as a response to terrorist threats. The current article shows the good ability of electrochemical sensors to the trace detection or discrimination of explosives.
Technology of Foamed Propellants
Authors: Böhnlein‐Mauß Jutta , Kröber Hartmut
Published: June 2009

Foamed propellants are based on crystalline explosives bonded in energetic reaction polymers. Due to their porous structures they are distinguished by high burning rates. Energy content and material characteristics can be varied by using different energetic fillers, energetic polymers and porous structures. Foamed charges can be produced easily by the reaction injection moulding process. For the manufacturing of foamed propellants a semi‐continuous remote controlled production plant in pilot scale was set up and a modified reaction injection moulding process was applied.
Blast Load Diagnostic
Authors: Held Manfred
Published: June 2009

Damage is mostly caused by the impulse transferred to the target. Therefore, the impulsive load measurements are summarized, which were mostly performed with simple and inexpensive test arrangements. This was possible, especially in the near field, where blast and blast fragment loads were causing damage to the soft as well as harder target structures. For more details, the used arrangements and results can be found in the reference list.
US regional income change and migration: 1995–2004
Authors: Shumway J. Matthew , Otterstrom Samuel
Published: June 2009

One of the most important concepts found in the migration literature is that it is a selective process, both in terms of who migrates and in the migrants' individual movement trajectories. The selectivity of migration means that the population structure at both origin and destination will change over time through migration, thus influencing the socio‐economic fabric of both sending and receiving regions. In this study we are primarily interested in the selectivity of migration relative to income and how migration affects the distribution of income across metropolitan areas in the U.S. We first cluster metropolitan areas by housing costs and then examine the flow of income migration relative to these costs using IRS county‐to‐county migration data for the years 1994/95 through 2003/04. Both total aggregate and per capita incomes by housing market clusters show some significant changes over the time frame used in this paper with moderate priced housing markets and non‐metropolitan areas the biggest gainers in aggregate income and some high priced housing markets and (once again) nonmetropolitan areas the biggest gainers in per capita income. Copyright © 2009 John Wiley & Sons, Ltd.
Metastability in the resistance of polycrystalline La0.8Li0.2MnO3
Authors: Knott J. C. , Lewis R. A.
Published: June 2009

Bulk polycrystalline La0.8Li0.2MnO3 is found to switch between a low‐resistance state and a high‐resistance state on thermal cycling. The low‐temperature, high‐resistance state exhibits strong electroresistance whereas the high‐temperature, low‐resistance state does not. The change in resistance between the two distinct states is of two orders of magnitude. It is proposed that the observed metastability may serve as the basis for resistive thermal‐switching devices.

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(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sample size considerations for Japanese patients in a multi‐regional trial based on MHLW guidance
Authors: Quan Hui , Zhao Peng‐Liang , Zhang Ji , Roessner Martin , Aizawa Kyo
Published: June 2009

Since the publication of the International Conference on Harmonization E5 guideline, new drug approvals in Japan based on the bridging strategy have been increasing. To further streamline and expedite new drug development in Japan, the Ministry of Health, Labour and Welfare, the Japanese regulatory authority, recently issued the ‘Basic Principles on Global Clinical Trials' guidance to promote Japan's participation in multi‐regional trials. The guidance, in a Q&A format, provides two methods as examples for recommending the number of Japanese patients in a multi‐regional trial. Method 1 in the guidance is the focus of this paper. We derive formulas for the sample size calculations for normal, binary and survival endpoints. Computations and simulation results are provided to compare different approaches. Trial examples are used to illustrate the applications of the approaches. Copyright © 2009 John Wiley & Sons, Ltd.
A comparative method to evaluate and validate stochastic parametrizations
Authors: Hermanson Leon , Hoskins Brian , Palmer Tim
Published: June 2009

There is a growing interest in using stochastic parametrizations in numerical weather and climate prediction models. Previously, Palmer (2001) outlined the issues that give rise to the need for a stochastic parametrization and the forms such a parametrization could take. In this article a method is presented that uses a comparison between a standard‐resolution version and a high‐resolution version of the same model to gain information relevant for a stochastic parametrization in that model. A correction term that could be used in a stochastic parametrization is derived from the thermodynamic equations of both models. The origin of the components of this term is discussed. It is found that the component related to unresolved wave–wave interactions is important and can act to compensate for large parametrized tendencies. The correction term is not proportional to the parametrized tendency. Finally, it is explained how the correction term could be used to give information about the shape of the random distribution to be used in a stochastic parametrization. Copyright © 2009 Royal Meteorological Society
Path‐following algorithms and experiments for an unmanned surface vehicle
Authors: Bibuli Marco , Bruzzone Gabriele , Caccia Massimo , Lapierre Lionel
Published: June 2009

This paper addresses the problem of path following in two‐dimensional space for underactuated unmanned surface vehicles (USVs), defining a set of guidance laws at the kinematic level. The proposed nonlinear Lyapunov‐based control law yields convergence of the path‐following error coordinates to zero. Furthermore, the introduction of a virtual controlled degree of freedom for the target to be followed on the path removes singularity behaviors present in other guidance algorithms proposed in the literature. Some heuristic approaches are then proposed to face the problem of speed of advance adaptation based on path curvature measurement and steering action prediction. Finally a set of experimental results of all the proposed guidance laws, carried out with the Charlie USV, demonstrates the feasibility of the proposed approach and the performance improvements, in terms of precision in following the reference path and transient reduction, obtained by introducing speed adaptation heuristics. © 2009 Wiley Periodicals, Inc.
Semiparametric ROC surfaces for continuous diagnostic tests based on two test measurements
Authors: Wan Shuwen , Zhang Biao
Published: June 2009

We propose a semiparametric method for estimating ROC surfaces for continuous diagnostic tests based on two test measurements. Such a three‐class diagnostic problem based on two test measurements arises naturally from some DNA amplification‐related diagnostic scenarios. Simulation results show that our proposed semiparametric ROC surface estimator is more efficient than the nonparametric counterpart and is quite comparable with the parametric counterpart when model assumption of the data is correctly specified for the parametric method. Moreover, when the parametric model assumption is not true, our proposed semiparametric method is superior to both nonparametric and parametric methods. Some discussions and a simulated example along with R programs for implementation of the proposed method are also provided. Copyright © 2009 John Wiley & Sons, Ltd.
A simple G‐computation algorithm to quantify the causal effect of a secondary illness on the progression of a chronic disease
Authors: van der Wal W. M. , Prins M. , Lumbreras B. , Geskus R. B.
Published: June 2009

Progression of a chronic disease can lead to the development of secondary illnesses. An example is the development of active tuberculosis (TB) in HIV‐infected individuals. HIV disease progression, as indicated by declining CD4 + T‐cell count (CD4), increases both the risk of TB and the risk of AIDS‐related mortality. This means that CD4 is a time‐dependent confounder for the effect of TB on AIDS‐related mortality. Part of the effect of TB on AIDS‐related mortality may be indirect by causing a drop in CD4. Estimating the total causal effect of TB on AIDS‐related mortality using standard statistical techniques, conditioning on CD4 to adjust for confounding, then gives an underestimate of the true effect. Marginal structural models (MSMs) can be used to obtain an unbiased estimate. We describe an easily implemented algorithm that uses G‐computation to fit an MSM, as an alternative to inverse probability weighting (IPW). Our algorithm is simplified by utilizing individual baseline parameters that describe CD4 development. Simulation confirms that the algorithm can produce an unbiased estimate of the effect of a secondary illness, when a marker for primary disease progression is both a confounder and intermediary for the effect of the secondary illness. We used the algorithm to estimate the total causal effect of TB on AIDS‐related mortality in HIV‐infected individuals, and found a hazard ratio of 3.5 (95 per cent confidence interval 1.2–9.1). Copyright © 2009 John Wiley & Sons, Ltd.
Parent contribution and organizational control in international joint ventures
Authors: Chen Dong , Park Seung Ho , Newburry William
Published: June 2009

Organizational control scholars have recently noted how control use is not singular in organizations, but rather, different types of control are used to achieve different purposes. In international joint ventures (IJVs), we suggest that output, process, and social control are exercised by both foreign and local parent firms. We then hypothesize that a parent firm's usage of these three control types is influenced by its resource contributions. Using a sample of IJVs in China, we find that property‐based contribution is linked with output and process control, and knowledge‐based contribution is related to process and social control. The results also show differences in control practices between foreign and local parent firms. The findings provide important implications for the design and implementation of control systems in IJVs.
Parallel Preparation of Densely Packed Arrays of 150‐nm Gold‐Nanocrescent Resonators in Three Dimensions
Authors: Retsch Markus , Tamm Matthias , Bocchio Noelia , Horn Natalie , Förch Renate , Jonas Ulrich , Kreiter Maximilian
Published: June 2009

Metallic nanostructures show interesting optical properties due to their plasmonic resonances, and when arranged in three‐dimensional (3D) arrays hold promise for optical metamaterials with negative refractive index. Towards this goal a simple, cheap, and parallel method to fabricate large‐area, ordered arrays of 150‐nm gold nanocrescents supporting plasmonic resonances in the near‐infrared spectral range is demonstrated. In this process hexagonally ordered monolayers of monodisperse colloids are prepared by a simple floating technique, and subsequently the individual particles are size‐reduced in a plasma process and used as a shadow mask with the initial lattice spacing. The resulting two‐dimensional array of plasmonic resonators is coated with a transparent silica layer, which serves as a support for a second layer prepared by the identical process. The mutual orientation of the nanostructures between the individual layers can be freely adjusted, which determines the polarization‐dependent absorption of the array and opens the possibility to introduce chirality in this type of 3D metamaterial. The iteration of this simple and efficient methodology yields 3D arrays with optical features as sharp as those of the individual nanocrescents, and shows strong potential for large‐scale production of high‐quality optical metamaterials.
Cell Adhesion and Spreading Affect Adipogenesis from Embryonic Stem Cells: The Role of Calreticulin
Authors: Szabo Eva , Feng Tianshu , Dziak Ewa , Opas Michal
Published: June 2009

Calreticulin is an endoplasmic reticulum-resident multifunctional protein, which has been shown to influence numerous cellular processes, including cell adhesion. In this study, we characterized the adhesive properties of embryonic stem cells (ESCs) lacking calreticulin and showed that adipogenesis from ESCs is directly and reciprocally controlled by the adhesive status of a cell, which in turn is modulated by calreticulin. Calreticulin-deficient ESCs are not only highly adipogenic but also show elevated calmodulin/CaMKII signaling and poor adhesiveness compared with the wild-type ESCs. Calreticulin deficiency leads to a disorganized cytoskeleton and low levels of focal adhesion-related proteins, such as vinculin, paxillin, and phosphorylated focal adhesion kinase, which cause limited focal adhesion formation and limited fibronectin deposition. Moreover, differentiation on nonadhesive substrata, which hinder cell spreading, promoted adipogenesis in the wild-type ESCs that normally have low adipogenic potential, causing a decrease in focal adhesion protein expression and an increase in calmodulin/CaMKII signaling. In contrast, inhibition of CaMKII effectively increased focal adhesion protein levels and inhibited adipogenesis in calreticulin-deficient ESCs, causing them to behave like the low adipogenic, wild-type ESCs. Thus, the adipogenic potential of ESCs is proportional to their calmodulin/CaMKII activity but is inversely related to their focal adhesion protein levels and degree of adhesiveness/spreading.

Disclosure of potential conflicts of interest is found at the end of this article.
Implanted Adult Human Dental Pulp Stem Cells Induce Endogenous Axon Guidance
Authors: Arthur Agnieszka , Shi Songtao , Zannettino Andrew C. W. , Fujii Nobutaka , Gronthos Stan , Koblar Simon A.
Published: June 2009

The human central nervous system has limited capacity for regeneration. Stem cell-based therapies may overcome this through cellular mechanisms of neural replacement and/or through molecular mechanisms, whereby secreted factors induce change in the host tissue. To investigate these mechanisms, we used a readily accessible human cell population, dental pulp progenitor/stem cells (DPSCs) that can differentiate into functionally active neurons given the appropriate environmental cues. We hypothesized that implanted DPSCs secrete factors that coordinate axon guidance within a receptive host nervous system. An avian embryonic model system was adapted to investigate axon guidance in vivo after transplantation of adult human DPSCs. Chemoattraction of avian trigeminal ganglion axons toward implanted DPSCs was mediated via the chemokine, CXCL12, also known as stromal cell-derived factor-1, and its receptor, CXCR4. These findings provide the first direct evidence that DPSCs may induce neuroplasticity within a receptive host nervous system.

Disclosure of potential conflicts of interest is found at the end of this article.
Human Alternatives to Fetal Bovine Serum for the Expansion of Mesenchymal Stromal Cells from Bone Marrow
Authors: Bieback Karen , Hecker Andrea , Kocaömer Asli , Lannert Heinrich , Schallmoser Katharina , Strunk Dirk , Klüter Harald
Published: June 2009

Mesenchymal stromal cells (MSCs) are promising candidates for novel cell therapeutic applications. For clinical scale manufacturing, human factors from serum or platelets have been suggested as alternatives to fetal bovine serum (FBS). We have previously shown that pooled human serum (HS) and thrombin-activated platelet releasate in plasma (tPRP) support the expansion of adipose tissue-derived MSCs. Contradictory results with bone marrow (BM)-derived MSCs have initiated a comprehensive comparison of HS, tPRP, and pooled human platelet lysate (pHPL) and FBS in terms of their impact on MSC isolation, expansion, differentiation, and immunomodulatory activity. In addition to conventional Ficoll density gradient centrifugation, depletion of lineage marker expressing cells (RosetteSep) and CD271+ sorting were used for BM-MSC enrichment. Cells were cultured in medium containing either 10% FBS, HS, tPRP, or pHPL. Colony-forming units and cumulative population doublings were determined, and MSCs were maximally expanded. Although both HS and tPRP comparable to FBS supported isolation and expansion, pHPL significantly accelerated BM-MSC proliferation to yield clinically relevant numbers within the first two passages. MSC quality and functionality including cell surface marker expression, adipogenic and osteogenic differentiation, and immunosuppressive action were similar in MSCs from all culture conditions. Importantly, spontaneous cell transformation was not observed in any of the culture conditions. Telomerase activity was not detected in any of the cultures at any passage. In contrast to previous data from adipose tissue-derived MSCs, pHPL was found to be the most suitable FBS substitute in clinical scale BM-MSC expansion.

Disclosure of potential conflicts of interest is found at the end of this article.
High prevalence of defects in Cesarean section scars at transvaginal ultrasound examination
Authors: Vikhareva Osser O. , Jokubkiene L. , Valentin L.
Published: June 2009

Objectives

To determine the ability to correctly identify Cesarean section scars, to estimate the prevalence of defective scars, and to determine the size and location of scar defects by transvaginal ultrasound imaging.

Methods

Two hundred and eighty‐seven women underwent transvaginal ultrasound examination 6–9 months after delivery: 108 had undergone one Cesarean section, 43 had had two Cesarean sections, 11 had undergone at least three Cesarean sections, and 125 were primiparae who had delivered vaginally. The ultrasound examiner was blinded to the obstetric history until all scans had been evaluated.

Results

None of the 125 vaginally delivered women had a visible scar in the uterus, whereas all women who had undergone Cesarean section had at least one visible scar. Median myometrial thickness at the level of the isthmus was 11.6 mm in women who had only been delivered vaginally, and 8.3 mm, 6.7 mm and 4.7 mm in women who had undergone one, two and at least three Cesarean sections, respectively (P < 0.001). Scar defects were seen in 61% (66/108), 81% (35/43) and 100% (11/11) of the women who had undergone one, two and at least three Cesarean sections (P = 0.002); at least one defect was classified as large by the ultrasound examiner in 14% (15/108), 23% (10/43) and 45% (5/11) (P = 0.027), and at least one total defect was seen in 6% (7/108), 7% (3/43) and 18% (2/11) (P = 0.336). In women who had undergone one Cesarean section, the median distance between an intact scar and the internal cervical os was 4.6 (range, 0–19) mm, and that between a deficient scar and the internal cervical os was 0 (range, 0–26) mm (P < 0.001).

Conclusions

Cesarean section scars can be detected reliably by ultrasound imaging. Myometrial thickness at the level of the isthmus uteri decreases with the number of Cesarean sections and the frequency of large scar defects increases. Scars with defects are located lower in the uterus than intact scars. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Responding to Amniotic Fluid Embolism
Authors: Dobbenga‐Rhodes Yvonne A.
Published: June 2009

Amniotic fluid embolism (AFE), an uncommon disorder with a high fatality rate, is an obstetric emergency that requires swift recognition and intervention to save both the mother's life and that of her child.

The high mortality rate and varying theories as to its cause make it difficult to diagnose AFE, which can occur at any point during labor and delivery, including during cesarean birth. These factors make it important for perioperative nurses to understand and recognize AFE when it occurs in the OR. Rapid delivery of the fetus is imperative for the survival of both mother and child. Monitoring and aggressively providing respiratory and circulatory support interventions are required if the mother is to survive AFE. AORN J 89 (June 2009) 1079–1088. © AORN, Inc, 2009.
Ebstein's Anomaly: A Complex Congenital Heart Defect
Authors: Cherry Cecile , DeBord Starla , Moustapha‐Nadler Noha
Published: June 2009

Ebstein's anomaly is a complex, congenital heart defect characterized by a malformation of the tricuspid valve and right side of the heart. A variety of cardiac abnormalities are associated with Ebstein's anomaly, including atrial septal defect, conduction system abnormalities, patent foramen ovale, pulmonary stenosis or atresia, and ventricular septal defect.

The clinical course of a patient with Ebstein's anomaly depends on the severity of the abnormalities present. Surgical repair of Ebstein's anomaly involves repair or replacement of the tricuspid valve and repair of any associated cardiac abnormalities. AORN J 89 (June 2009) 1098‐1110. © AORN, Inc, 2009.
The RN First Assistant: An Expert Resource for Surgical Site Infection Prevention
Authors: Pear Suzanne M. , Williamson Theresa H.
Published: June 2009

The role of the RN first assistant (RNFA) has expanded and evolved during the past three decades. Studies that have examined patient care outcomes relative to RNFAs substituting for surgeons as first assistants have noted no resulting adverse consequences, and the use of RNFAs in surgery may improve patient outcomes.

This article reports on an intervention to improve surgical outcomes in patients undergoing cardiac surgery that involved replacing surgical residents with RNFAs for the harvesting of saphenous vein grafts. The resulting benefits were a significant decrease in surgical times as well as improvement in surgical site infection rates. AORN J 89 (June 2009) 1093–1097. © AORN, Inc, 2009.
Latex in the Perioperative Setting: Strategies for Patient and Staff Member Safety
Authors: Nelson Jason
Published: June 2009

Latex in the Perioperative Setting: Strategies for Patient and Staff Member Safety, Ciné‐Med, producer, 2009, $120 AORN members, $240 nonmembers
The PsbP protein, but not the PsbQ protein, is required for normal thylakoid architecture in Arabidopsis thaliana
Authors: Yi Xiaoping , Hargett Stefan R. , Frankel Laurie K. , Bricker Terry M.
Published: June 2009

Interfering RNA was used to suppress the expression of the genes At1g06680 and At2g30790 in Arabidopsis thaliana, which encode the PsbP‐1 and PsbP‐2 proteins, respectively, of Photosystem II. A phenotypic series of transgenic plants was recovered that expressed intermediate and low amounts of PsbP. Earlier we had documented significant alterations in a variety of Photosystem II parameters in these plant lines [Yi, X., Liu, H., Hargett, S. R., Frankel, L. K., Bricker, T. M. (2007). The PsbP protein is required for photosystem II complex assembly/stability and photoautotrophy in Arabidopsis thaliana. J. Biol. Chem. 34, 24833–24841]. In this communication, we document extensive defects in the thylakoid membrane architecture of these plants. Interestingly, strong interfering RNA suppression of the genes encoding the PsbQ protein (At4g21280 and At4g05180) was found to have no effect on the architecture of thylakoid membranes.
Biochemical characterization of an ABC transporter LptBFGC complex required for the outer membrane sorting of lipopolysaccharides
Authors: Narita Shin-ichiro , Tokuda Hajime
Published: June 2009

MINT‐7137160: lptb (uniprotkb:P0A9V1) physically interacts (MI:0914) with lptf (uniprotkb:P0AF98) and lptg (uniprotkb:P0ADC6) by pull down (MI:0096)
Proposing and testing the contextual gender influence theory: An examination of gender influence types on trust of computer agents
Authors: Lee Eun‐Ju , Schumann David W.
Published: June 2009

The purpose of this research is to examine gender‐based determinants of consumer trust towards computer agents. Employing multiple literatures, we propose a contextual gender influence theory (CGIT) which has direct bearing on trust in online exchange relationships. A set of studies is presented that begin to demonstrate how the effects of gender identity on human‐to‐computer interaction are not the same for person‐to‐person interaction. Indeed, employing both gaming and shopping exchange environments, the results reveal that while biological gender identity appears in a person‐to‐person interaction as concerns trust, psychological gender identity (specifically femininity) and not biological gender identity, influences relationship trust online.
The *amn'tgap: The view from West Yorkshire
Authors: BROADBENT JUDITH M.
Published: June 2009

The absence ofI amn'tfor the first person singular present tense negative form is taken to indicate that there is a gap in the paradigm. Recent accounts take a morphosyntactic approach and phonology is largely ignored. Such accounts typically focus on contemporary forms of Standard English. This paper, in contrast, compares nineteenth-century and contemporary West Yorkshire (WY) aux+n'tforms and pursues a largely phonological solution. The paper sets out to demonstrate that WY has never had a *amn'tgap and that changes over the past century shed light on the *amn'tgap problem. Contemporary WY is known to exhibit a phenomenon called secondary contraction, wherebyshouldn't[ʃʊdʔ], for example, may be pronounced [ʃunʔ]. I argue that secondary contraction is responsible for the creation of homophones foramn'tandaren't: [aːnt]/[aːt]. I will consider the possibility that certain aux+n'tforms have become lexicalised and that this has triggered secondary contraction as a phonological repair strategy. With the analysis of WY data as a backdrop, the paper then pursues the possibility that lexicalisation may have occurred, at a much earlier date, in precursors of Standard British English (SBE). Indeed, it seems plausible that homophony foramn'tandaren'tmay have led to prescription against new realisations ofamn't. The paper will show that grammaticallyamn'thas evolved in exactly the same way as other auxn'tforms, and it is only commentators who have treated it differently. If this is so, the *amn'tgap in SBE is man-made rather than grammatical in nature.
Saturation and reification in adjectival diathesis
Authors: LANDAU IDAN
Published: June 2009

The study of adjectival diathesis alternations lags behind the study of verbal diathesis and nominalization. This paper aims to diminish the gap by applying to the adjectival domain theoretical tools with proven success elsewhere. We focus on evaluative adjectives, which display a systematic alternation between a basic variant (John was rude) and a derived one (That was rude of John). The alternation brings about a cluster of syntactic and semantic changes – in the semantic type of the predicate, its valency and the mode of argument projection. We argue that the adjectival variants are related by the joint application of two operators: a lexicalsaturationoperator (also seen in verbal passive) and a syntacticreificationoperator (also seen in nominalization). The analysis straightforwardly extends to similar alternations with Subject- and Object-Experiencer adjectives (proud,irritating). Among its important implications are (i) lexical saturation is not restricted to external arguments (internal ones may also be saturated), and (ii) ‘referential’ (R) roles are not restricted to nominal predicates (adjectives may assign them as well).
RNA-interference methods for gene-knockdown in the sea louse, Lepeophtheirus salmonis: studies on a putative prostaglandin E synthase
Authors: CAMPBELL E. M. , PERT C. C. , BOWMAN A. S.
Published: June 2009

Harnessing the full utility of extensive gene sequences recently available for the economically important sea louse, Lepeophtheirus salmonis, requires the adaptation of modern molecular biology approaches to this non-model organism. Using a putative microsomal prostaglandin E synthase type-2 (PGES2) as a candidate gene, we investigated gene-knockdown by double-stranded RNA interference (dsRNAi) in the small free-living and the larger parasitic stages of L. salmonis. dsRNA was administered to nauplius and copepodid stages by immersion for 7 h. Pre-adult and adults received dsRNA by intra-haemocoelic injection. The extent, speed and persistence of the knockdown effects were determined by RT-PCR. LsPGES2 was abundantly expressed in all life stages, including the non-parasitic stages. Administration of dsRNA to nauplius and copepodids by immersion had no effect on mortality rates and moulting through to copepodids was observed. Dramatic knockdown of LsPGES2 was observed within 7 h and persisted for at least 48 h. Injection of dsRNA had no effect on mortality in pre-adults and adults, but knockdown of LsPGES2 was apparent within 24 h, reaching 95% over the 72 h and was persistent for at least 120 h. The methods developed resulted in rapid and persistent knockdown in L. salmonis suitable for studies in the different stadia.
Population estimates of emperor penguins at Amanda Bay, Ingrid Christensen Coast, Antarctica
Authors: Wienecke Barbara , Pedersen Peter
Published: June 2009

In 2008, the emperor penguin Aptenodytes forsteri colony at Amanda Bay, East Antarctica, was designated an Antarctic Specially Protected Area by the 31st Antarctic Treaty Consultative Meeting in Kyiv, Ukraine. It is only the third emperor penguin colony in the Australian Antarctic Territory to receive this status. The colony has been known to exist since 1956 and numerous visits have been made to it, especially by personnel from Australia's Davis station. On a number of occasions, attempts were made to estimate the number of birds in the colony in order to obtain an insight into the size of the breeding population. Here we report on the history of visitation to the colony since the 1950s and examine the quality of information collected with regard to the usefulness of this information in terms of population analyses. We also report the results of the first visit to the Amanda Bay colony made in winter with the specific purpose of estimating the number of birds present and of highlighting the need for long term monitoring programmes to assess the viability of emperor penguins in future.
The first Antarctic whaling season ofAdmiralen(1905–1906): the diary of Alexander Lange
Authors: Adie Susan , Basberg Bjørn L.
Published: June 2009

The first factory ship of the so-called modern era of Antarctic whaling wasAdmiralen, arriving together with two smaller catcher boats in the South Shetland Islands in January 1906, after a period of whaling in the Falkland Islands. The expedition leader was Alexander Lange, a Norwegian whaler with a long experience from whaling in northern Norway and Spitsbergen. He kept a diary for a considerable period and this covered several whaling voyages. The one dealing with the pioneer Antarctic season of 1905–1906 has been translated from Norwegian into English and is presented here with an introduction that places the expedition into its wider context.