bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of climate change and urbanization on the runoff of the Rock Creek basin in the Portland metropolitan area, Oregon, USA
Authors: Franczyk Jon , Chang Heejun
Published: November 2008

Climate changes brought on by increasing greenhouse gases in the atmosphere are expected to have a significant effect on the Pacific Northwest hydrology during the 21st century. Many climate model simulations project higher mean annual temperatures and temporal redistribution of precipitation. This is of particular concern for highly urbanized basins where runoff changes are more vulnerable to changes in climate. The Rock Creek basin, located in the Portland metropolitan area, has been experiencing rapid urban growth throughout the last 30 years, making it an ideal study area for assessing the effect of climate and land cover changes on runoff. A combination of climate change and land cover change scenarios for 2040 with the semi‐distributed AVSWAT (ArcView Soil and Water Assessment Tool) hydrological model was used to determine changes in mean runoff depths in the 2040s (2030–2059) from the baseline period (1973–2002) at the monthly, seasonal, and annual scales. Statistically downscaled climate change simulation results from the ECHAM5 general circulation model (GCM) found that the region would experience an increase of 1·2 °C in the average annual temperature and a 2% increase in average annual precipitation from the baseline period. AVSWAT simulation shows a 2·7% increase in mean annual runoff but a 1·6% decrease in summer runoff. Projected climate change plus low‐density, sprawled urban development for 2040 produced the greatest change to mean annual runoff depth (+5·5%), while climate change plus higher‐density urban development for 2040 resulted in the smallest change (+5·2%), when compared with the climate and land cover of the baseline period. This has significant implications for water resource managers attempting to implement adaptive water resource policies to future changes resulting from climate and urbanization. Copyright © 2008 John Wiley & Sons, Ltd.
Local matrix metalloproteinase 2 gene knockdown in balloon‐injured rabbit carotid arteries using nonviral‐small interfering RNA transfection
Authors: Hlawaty Hanna , San Juan Aurélie , Jacob Marie‐Paule , Vranckx Roger , Letourneur Didier , Feldman Laurent J.
Published: November 2008

Background

Small interfering RNA (siRNA) delivery is a promising approach for the treatment of cardiovascular diseases. Matrix metalloproteinase (MMP) 2 over‐expression in the arterial wall has been implicated in restenosis after percutaneous coronary intervention, as well as in spontaneous atherosclerotic plaque rupture. We hypothesized that in vivo local delivery of siRNA targeted at MMP2 (MMP2‐siRNA) in the balloon‐injured carotid artery of hypercholesterolemic rabbits may lead to inhibition of MMP2 expression.

Methods

Two weeks after balloon injury, 5 µmol/l of Tamra‐tagged MMP2‐siRNA, scramble siRNA or saline was locally injected in the carotid artery and incubated for 1 h.

Results

Fluorescent microscopy studies showed the circumferential uptake of siRNA in the superficial layers of neointimal cells. MMP2 mRNA levels, measured by the real‐time reverse transcriptase‐polymerase chain reaction, was decreased by 79 ± 25% in MMP2‐siRNA‐ versus scramble siRNA‐transfected arteries (p < 0.05). MMP2 activity, measured by gelatin zymography performed on the conditioned media of MMP2‐siRNA versus scramble siRNA transfected arteries, decreased by 53 ± 29%, 50 ± 24% and 46 ± 14% at 24, 48 and 72 h, respectively (p < 0.005 for all). No effect was observed on MMP9, pro‐MMP9 and TIMP‐2 levels.

Conclusions

The results obtained in the present study suggest that significant inhibition of gene expression can be achieved with local delivery of siRNA in the arterial wall in vivo. Copyright © 2008 John Wiley & Sons, Ltd.
Raman to the limit: tip‐enhanced Raman spectroscopic investigations of a single tobacco mosaic virus
Authors: Cialla Dana , Deckert‐Gaudig Tanja , Budich Christian , Laue Michael , Möller Robert , Naumann Dieter , Deckert Volker , Popp Jürgen
Published: November 2008

The development of fast identification techniques of viruses is an ongoing important research topic. Conventional virus detection and identification is generally based on various different microbiological methods. However, these techniques are not suitable for the analysis of single virus particles. Therefore, our goal is to establish tip‐enhanced Raman scattering (TERS), providing vibrational spectroscopic information with a spatial resolution less than 50 nm, to characterize single viruses at a molecular level. Here we report, to the best of our knowledge for the first time, about TERS spectra of a tobacco mosaic virus, showing the great capability of this technique. However, the application of the TERS technique for a rapid and direct detection of different species of single viruses is under development, which is useful for a wide range of analytical fields. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of cathodic protection on macrocell currents: A viable method to monitor and control the efficiency of CP?
Authors: Schwarz W. , Tritthart J.
Published: November 2008

Corrosion protection of steel reinforcement in concrete structures by cathodic protection (CP) is a cost effective, reliable, and widely accepted method to stop and prevent the corrosion of the steel reinforcement. The efficiency of CP is usually monitored by the “24 h, 100 mV depolarization criterion,” a purely empirical criterion whose implementation is cost and labor intensive and that does not allow online control of CP. Within an extended research project on CP applied to concrete members of a highway bridge exposed to penetrating moisture, three sets of macrocells (MC), each composed of five MC sensors, were installed in conjunction with concrete resistance sensors and silver/silver chloride reference cells. Chloride profiles were determined from the cored or drilled powder originating from the installation of sensors and from drilling cores. Corrosion currents, steel potentials, and concrete resistance were monitored over a period of 1 year before, after installing the CP systems (which remained switched off for half a year for evaluating the effect of the conductive coating), and after start‐up of the CP systems. The CP systems applied consist of a moisture resistant conductive coating. As expected CP has a pronounced effect on local MC currents: Anodic MC currents were reduced or changed into cathodic currents, whereas cathodic currents were only weakly influenced. By adjusting the applied protection current all anodic MC currents may be changed into cathodic MC currents. Results indicate that the 100 mV depolarization criterion is a conservative criterion in atmospherically exposed concrete; it is not reliable in strongly wetted concrete. There was no consistent correlation between the CP induced changes in the local MC currents and 24 h depolarization values indicating that large potential shifts induced by CP do not necessarily imply overprotection. Results show that monitoring MC currents before, during, and after CP operation allows to demonstrate in a transparent way the effect of CP on the corrosion of the steel reinforcement. Online monitoring of MC currents is proposed as a viable and comprehensible method to monitor and control the efficiency of CP.
Influence of temperature and humidity on Portland cement mortar resistivity monitored with inner sensors
Authors: Villagrán Zaccardi Y. A. , Fullea García J. , Huélamo P. , Di Maio Á. A.
Published: November 2008

Concrete resistivity is directly related to relative humidity (RH) and is also affected by temperature. In this paper, a theoretical discussion about how these two factors affect resistivities of concrete and mortar is provided. Moreover, experimental results on sensorized mortar probes are presented and correlated to analytical models of temperature and humidity influences. All measurements were performed under controlled conditions. Temperature, RH, and resistivity were measured simultaneously in a particular zone of the probes. Temperature scanning was performed over short periods of time (approximately 1 h) and the probes were covered with waterproof paraffin each time for constant humidity content. This was feasible as all sensors were embedded. Water contents were ensured during the experiment by weighting the probes. Conclusions on the applicability of these techniques, their advantages, and limitations, and correlation to Archie and Arrhenius laws of the results are made.
Stress corrosion cracking and selective corrosion of copper‐zinc alloys for the drinking water installation
Authors: Brandl E. , Malke R. , Beck T. , Wanner A. , Hack T.
Published: November 2008

Despite a generally good corrosion resistance to tap and industrial water, many brass taps and fittings have failed in the past by stress corrosion cracking (SCC) and selective corrosion (dezincification or preferred removal of a phase). The experimental investigations of the present study clarify the influence of the ammonia concentration on the two types of corrosion. Notched specimens made of the alloys CuZn39Pb3, CuZn40Pb2, CuZn37, CuZn36Pb2As and CuZn21Si3P are polarized anodically in pure tap water and tap water with realistic ammonia concentrations (15 and 30 ppm) under a simultaneous mechanical loading condition. The influence of stress and of the third alloying elements lead and arsenic are investigated and evaluated. The experiments show that the ammonia additions significantly increase the risk of dezincification of the α‐β‐brasses. The arsenic in the CuZn36Pb2As alloy avoids dezincification, but enhances the risk of SCC. The rate of selective corrosion and SCC consistently increases with increase in tensile stress.
Study of a purple gold‐based alloy resistance to tarnishing in a sulphuric solution
Authors: Carvalho O. , Soares D. , Fonseca A. , Silva F. S.
Published: November 2008

The stability of some coloured gold alloys is dependent on the environment. In this work, the effect of a sulphuric solution on the physical properties of a purple gold‐based alloy is studied. Changes in the physical properties of the samples namely colour, brightness and reflectance were measured with time in the referred environment. It was observed that significant changes occurred even for a small exposure time. A selective dissolution of aluminium was found to be the main alloy corrosion mechanism, which is responsible for the changes in superficial physical characteristics. At the end of the experiments, the sample surface modification was analyzed by optical and SEM/EDS microscopy. The surface corrosion process resulted in the formation of a large number of superficial fissures with a significant thickness and length, essentially in the Al2Au phase. XPS spectroscopy was used in order to identify the compounds formed in the corrosion process.
Investigations on the re‐passivation of carbon steel in chloride containing concrete in consequence of cathodic polarisation
Authors: Eichler T. , Isecke B. , Bäßler R.
Published: November 2008

Although the complex changes at the steel–concrete interface due to cathodic polarisation are widely acknowledged to have a beneficial influence concerning the cathodic protection (CP) of steel in concrete, some questions concerning the repassivation of carbon steel in consequence of cathodic polarisation are still not satisfactorily clarified. In the recent literature, some indications are presented that repassivation occurs after a certain time of polarisation. Therefore, the investigations discussed in this paper aim to clarify, to what extent the re‐passivation of carbon steel due to cathodic polarisation occurs, and if the ennoblement of OCP is a sufficient indication for repassivation. In a first step, the corrosion state of five nominal equal test specimens was determined by electrochemical impedance spectroscopy (EIS). After determining the initial corrosion state by evaluating the charge transfer resistance and the polarisation resistance, respectively, the specimens were polarised cathodically. Impedance data were recorded before, during and after polarisation. The impedance data were evaluated by equivalent circuit fitting with special attention to charge transfer resistances and the impact of diffusion on the corrosion and polarisation behaviour. The results indicate that the reduction of oxides and oxygen diffusion during cathodic polarisation has strong impact on the systems behaviour and that repassivation effects occur after switching off the polarisation current and during depolarisation, respectively.
Conventional and pulse cathodic protection of reinforced concrete: Electrochemical behavior of the steel reinforcement after corrosion and protection
Authors: Koleva D. A. , Guo Z. , van Breugel K. , de Wit J. H. W.
Published: November 2008

The applicability and efficiency of an alternative for impressed current cathodic protection (CP) for reinforced concrete, based on pulse technology, was investigated. The technique, denoted as pulse CP (pCP), was evaluated on the basis of a comparative analysis to reference (non‐corroding), corroding, and conventional CP conditions, in terms of long‐term monitoring of electrochemical parameters for the embedded steel with time of corrosion and protection. The hereby reported results are for the total duration of the experiment, i.e., 460 days of conditioning, also presented in comparison with earlier stages. Protection was applied after corrosion was initiated (using corrosion medium of 5% NaCl), at different time intervals (here reported are starting points 60 and 150 days of age). Both CP regimes used current density of 5 or 20 mA/m2 steel surface. The pulse CP was applied as a pulse‐shaped block current (square wave) with the current itself being the feedback control signal, using 12.5–50% duty cycle at 500 Hz to 1 kHz frequency. Under equal environmental conditions and for a comparatively long period of application, the pulse CP was found to perform as effectively as the conventional CP with regard to electrochemical behavior of the steel reinforcement. Furthermore, the pulse CP technique was found to achieve more rapidly the so called “open circuit potential (OCP) passivity” as a result of an enhanced ion transport (chloride withdrawal) and more favorable cement chemistry (increased alkalinity around the steel reinforcement).
Chemical exchange in novel spirobicyclic zwitterionic Janovsky complexes using dynamic 1H NMR spectroscopy
Authors: Culf A. S. , Čuperlović‐Culf M. , Ouellette R. J.
Published: November 2008

Highly coloured Janovsky complexes have been known for over 120 years, being used in many colourimetric analytical procedures. In this present study, two novel and stable nitrocyclohexadienyl spirobicyclic, zwitterionic Janovsky anionic hydantoin σ‐complexes, rac‐1,3‐diisopropyl‐6‐nitro‐2,4‐dioxo‐1,3‐diazaspiro[4.5]deca‐6,9‐dien‐8‐ylideneazinate, ammonium internal salt (1) and 1,3‐diisopropyl‐2,4‐dioxo‐1,3‐diazaspiro[4.5]deca‐6,9‐dien‐8‐ylideneazinate, ammonium internal salt (2) have been prepared and characterised by NMR, electrospray ionization mass spectrometry (ESI‐MS) and UV/visible methods. For the p‐mononitro‐substituted complex (2), we discovered chemical exchange behaviour using 1D saturation transfer and 2D exchange spectroscopy (EXSY) 1H NMR techniques. The coalescence temperature was determined to be 62 °C in d3‐acetonitrile. Analysis of these data provided a Gibbs free energy of activation, ΔG ‡, of + 67 kJ mole−1, a rate constant, k, coalescence of 220 Hz and an equilibrium constant, Keqm, of 0.98 as estimates of the exchange process in this solvent. Of the two mechanisms proposed for this fluxional behaviour, ring opening to a substituted benzene or proton exchange, a further theoretical modelling study of 1D 1H NMR spectra was able to confirm that simple proton exchange between the two nitrogen sites of the hydantoin ring provided an accurate simulation of the observed experimental evidence. Interestingly, the o,p‐dinitro‐substituted complex (1) did not show any chemical exchange behaviour up to 150 °C in d3‐acetonitrile (to 75 °C) and d6‐dimethyl sulfoxide (DMSO). Molecular modelling at the MM2 level suggests that steric collisions of an N‐acyl isopropyl substituent of the hydantoin ring with the ortho‐nitro group of the spirofused cyclohexadienyl ring prevents the proposed proton exchange mechanism occurring in this case. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd
Complete assignments of NMR data of salens and their cobalt (III) complexes
Authors: Woo Yoonkyung , Koh Dongsoo , Lim Yoongho
Published: November 2008

Salens, derived from 1,2‐ethylenediamine and salicylaldehydes, have been widely used as ligands for metal complexes which have been showing enormous potential in chemical properties of asymmetric catalysts as well as biological properties such as anticancer agents. Almost all of the salen–metal complexes with their corresponding metal (II)‐complexes show the evidences of chelation of two oxygens in salens. However, several metal (II) complexes, especially cobalt (II) complexes, could not show NMR spectra due to their paramagnetism. Recently, it has been reported that one of the cobalt (III) complexes was used for NMR spectroscopy to evaluate its stereoselectivity as a catalyst. Even though many salen ligands are known, their NMR data are not assigned completely. It was possible that modification in northern part of salen with 2‐hydroxyphenyl group afforded another oxygen chelation site in salen ligand. Here we report that synthesis and full NMR assignment of new salen ligands, which form meso 1,2‐bis(2‐hydroxyphenyl)ethylenediamine) and their cobalt (III) complexes. The assignments of 1H and 13C NMR data obtained in this experiment can help us to predict the NMR data of other salen ligands. Copyright © 2008 John Wiley & Sons, Ltd.
Increased risk of digoxin toxicity following hospitalization
Authors: Haynes Kevin , Hennessy Sean , Localio A. Russell , Cohen Abigail , Leonard Charles E. , Kimmel Stephen E. , Feldman Harold I. , Strom Brian L. , Metlay Joshua P.
Published: November 2008

Purpose

Adverse drug events (ADEs) are an important cause of preventable hospitalizations among elderly individuals taking high‐risk medications. The objective of the study was to identify health care system factors that affect the risk of digoxin toxicity for older adults on digoxin.

Methods

We conducted a prospective cohort study of older adults within the Pennsylvania Pharmaceutical Assistance Contract for the Elderly (PACE) program, which provides comprehensive drug benefits for older adults with low income. Subjects were interviewed at the time of enrollment regarding the management and coordination of their health care as well as medication comprehension. Hospitalizations were identified by linking patient identifiers to a state‐wide registry. Trained abstractors reviewed discharge summaries of possible digoxin related ADEs. Unadjusted and adjusted incidence rate ratios (IRR) were calculated based on person–months of exposure using Poisson regression models, with variances adjusted for within subject repeated measures.

Results

We enrolled a total of 2030 adults on digoxin from May 2002 to June 2003. A total of 34 hospitalizations due to digoxin toxicity occurred, equivalent to 1.12 hospitalizations per 1000 person–months of exposure. Adjusting for hospitalization in the past 2 months, age, total number physicians prescribing any medications in past 3 months, total number of pharmacies filling medications in past 3 months, and number of unique prescriptions filled in the past month had a 4.25‐fold increased risk of subsequently experiencing digoxin toxicity (IRR 95%CI 1.95, 9.27).

Conclusions

The risk of digoxin toxicity‐related hospitalization, while low, is higher in the post‐hospital period. Copyright © 2008 John Wiley & Sons, Ltd.
Phonon‐assisted excitation transfer in quantum dot molecules: from quantum kinetics to transfer rates
Authors: Machnikowski Paweł , Rozbicki Emil
Published: November 2008

We study the process of excitation transfer between vertically stacked dots due to the combined effect of the Förster coupling and carrier–phonon interaction. A consistent Markovian approximation is derived which reasonably reproduces the quantum‐kinetic results. The impact of the exciton transfer process on the temperature‐dependent intensity of spectral lines is discussed in terms of rate equations. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of momentum dependent matrix elements on scattering effects in quantum cascade lasers
Authors: Schmielau Tim , Pereira Mauro F.
Published: November 2008

Results for our fully frequency‐ and wavevector‐dependend self‐consistent nonequilibrium Green's function simulations of electron transport through quantum cascade lasers are compared to those from a simplified approach where scattering rates are only evaluated at representative ‘typical values’ of the in‐plane momentum due to the complexity of the underlying many‐body problem and the limited computational resources available. We find a noticeable impact on electronic lineshapes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical control of the spin state in a semimagnetic quantum dot
Authors: Kuhn Tilmann , Reiter Doris E. , Axt Vollrath Martin
Published: November 2008

In a Mn doped quantum dot the spin state of the Mn atom can be controlled via a well chosen sequence of laser pulses, which create or annihilate excitons in the quantum dot. The change of the state consists of a flip of the Mn spin accompanied by a simultaneous spin flip of an electron or light hole induced by the exchange interaction between Mn spin and electron or hole spin. All flipping processes can be interpreted in terms of exchange‐induced Rabi oscillations. The period and amplitude of the oscillations are determined by the coupling strength of the exchange interactions, which also strongly influences the energy splitting between the involved states. External magnetic fields can be used to tune the energies of the exciton states and thereby minimize the energy splitting between the states involved in the spin flip process. Thus the switching dynamics can be optimized by applying a magnetic field. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
G‐mode behaviour of closed ended single wall carbon nanotubes under pressure
Authors: Ghandour Ahmad J. , Dunstan D. J. , Sapelkin Andrei
Published: November 2008

We have performed high pressure Raman experiments on closed‐ended single wall carbon nanotubes using two different excitation wavelengths: 632.8 nm and 514 nm. We found that the shape of the G‐mode spectrum changes while changing the excitation wavelength at lower pressures, while it becomes similar at 3.5 GPa. In addition we record that the value of the transition pressure, associated with the structural transitions in the tubes, has also changed with changing the excitation wavelength even though we are examining tubes from the same produced sample. We attribute these results to the tubes having different electronic nature (metallic; semi‐conducting) and different diameters in resonance with each excitation wavelength. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure dependence of the Raman active vibrations in InP–CdS hybrid nanoparticles
Authors: Tallman R. E. , Weinstein B. A. , Trallero‐Giner C. , Sahoo Y. , Prasad P. N.
Published: November 2008

The effects of pressure on the confined and surface‐optical (SO) vibrations in core‐shell InP–CdS colloidal nanoparticles are explored experimentally by Raman scattering and theoretically using the phenomenological macroscopic approach (PMA) (F. Comas and C. Trallero‐Giner, Phys. Rev. B 67, 115301 (2003); C. Trallero‐Giner et al., to be published [1]). Experiments on two sample ensembles are carried out to P = 6.5 GPa at 373 K and 230 K (including laser heating) using diamond‐cells with 4:1 methanol:ethanol and pyridine media. We observe the pressure‐induced shifts of the peaks due to the confined LO‐ and TO‐like core modes, and of the broad feature assigned to SO vibrations at the CdS‐shell surface. PMA calculations are performed for the confined modes and the ℓ = 1, 2 SO modes in spherical geometry using pressure‐dependent bulk parameters as input. We compute the frequencies for different core radii and shell‐to‐core radius ratios γ. The best fit to the pressure data is found for an InP core diameter of 45 ± 10 A, and γ ∼ 1.1–1.4 depending on the sample ensemble and the value of ℓ. The effects of pressure on the InP–CdS core‐shell modes appear to be well described by the PMA formalism. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio calculations of ascorbic acid interacting with C61(COOH)2 complex under pressure
Authors: Zanella I. , Lemos V. , Guerini S.
Published: November 2008

Ab initio calculations were performed to study the interaction between a C61(COOH)2 complex with ascorbic acid under hydrostatic pressure. The system was found to support pressures up to 2.0 GPa, the value above which disruption of bonds was observed. At 2.0 GPa states are observed in the DOS where a HOMO–LUMO gap existed before application of the pressure. Also, the binding energy between the vitamin C and the remaining system is increased by ∼1.6 times when the pressure applied is 2.0 GPa. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of molybdate–benzotriazole surface treatment against copper tarnishing
Authors: Zhang Da‐Quan , Goun Joo Hyung , Yong Lee Kang
Published: November 2008

The synergistic effect of benzotriazole (BTAH) and molybdate on the inhibition of copper tarnish was studied in this paper. The antitarnish treatment of copper was conducted with BTAH solution containing molybdate. The surface morphology observation and composition analysis were investigated by SEM with energy dispersive X‐ray (EDX) spectroscopy. The addition of molybdate improved the protection of BTAH significantly. The BTAH + molybdate treated copper specimen has higher N concentration in its surface. The structure of the protective film was studied by XPS and AES measurements. It was characterized to be a complex of Cu(I)BTA. The antitarnish effect is certified by the formation of the protective Cu(I)BTA film. Molybdate does not participate in the formation of the protective film. The presence of molybdate promotes the passivation of copper. This facilitates the stabilization of the cuprous oxide film, and strengthens the adsorption of BTAH. Copyright © 2008 John Wiley & Sons, Ltd.
Surface characteristics analysis of nitrocarburized (Tenifer) and carbonitrided industrial steel AISI 02 types
Authors: Fares M.L. , Touhami M.Z. , Belaid M. , Bruyas H.
Published: November 2008

Generally, tool steels for cold work are obtained by rolling and forging processes. They are treated to have a structure conferring to the material a high toughness limit in terms of wear resistance and endurance. The objective of this study is the thermochemical heat treatment of industrial steel blades made of AISI 02 types, intended for polymer crushing. The effects of nitrocarburizing (Tenifer) and gaseous carbonitriding processes on surface characteristics are considered. These surface treatments increase the usefulness of properties, that is, fatigue strength, wear and corrosion resistance of this microalloyed steel. The influence of treatment duration and the thickness of the layers on surface properties are investigated. The analysis and characterization are carried out using physical analysis [optical microscopy, scanning electron microscopy, X‐ray diffraction and glow discharge optical emission spectroscopy (GDOES) techniques] and mechanical measurements (microhardness, weight loss and residual stresses) of treated material. The results are intended to contribute in defining and optimizing the adequate choice of treatments for this type of steel in industrial conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Joint modeling longitudinal semi‐continuous data and survival, with application to longitudinal medical cost data
Authors: Liu Lei
Published: November 2008

It has been increasingly common to analyze simultaneously repeated measures and time to failure data. In this paper we propose a joint model when the repeated measures are semi‐continuous, characterized by the presence of a large portion of zero values, as well as right skewness of non zero (positive) values. Examples include monthly medical costs, car insurance annual claims, or annual number of hospitalization days. A random effects two‐part model is used to describe respectively the odds of being positive and the level of positive values. The random effects from the two‐part model are then incorporated in the hazard of the failure time to form the joint model. The estimation can be carried out by Gaussian quadrature techniques conveniently implemented in SAS Proc NLMIXED. Our model is applied to longitudinal (monthly) medical costs of 1455 chronic heart‐failure patients from the clinical data repository at the University of Virginia. Copyright © 2008 John Wiley & Sons, Ltd.
Oligothiophene Assemblies Defined by DNA Interaction: From Single Chains to Disordered Clusters
Authors: Björk Per , Thomsson Daniel , Mirzov Oleg , Wigenius Jens , Inganäs Olle , Scheblykin Ivan G.
Published: November 2008

The organization of conjugated polyelectrolytes (CPEs) interacting with biomolecules sets conditions for the biodetection of biological processes and identity, through the use of optical emission from the CPE. Herein, a well‐defined CPE and its binding to DNA is studied. By using dynamic light scattering and circular dichroism spectroscopy, it is shown that the CPE forms a multimolecule ensemble in aqueous solution that is more than doubled in size when interacting with a small DNA chain, while single chains are evident in ethanol. The related changes in the fluorescence spectra upon polymer aggregation are assigned to oscillator strength redistribution between vibronic transitions in weakly coupled H‐aggregates. An enhanced single‐molecule spectroscopy technique that allows full control of excitation and emission light polarization is applied to combed and decorated λDNA chains. It is found that the organization of combed CPE–λDNA complexes (when dry on the surface) allows considerable variation of CPE distances and direction relative to the DNA chain. By analysis of the polarization data energy transfer between the polymer chains in individual complexes is confirmed and their sizes estimated.
Microreplication and Design of Biological Architectures Using Dynamic‐Mask Multiphoton Lithography
Authors: Nielson Rex , Kaehr Bryan , Shear Jason B.
Published: November 2008

A strategy for rapidly printing three‐dimensional (3D) microscopic replicas using multiphoton lithography directed by a dynamic electronic mask is reported. Morphological descriptions of 3D structures are encoded as stacks of 2D slices created from tomographic and computer‐designed instruction sets. In this manner, digital images serve as input for a sequence of reflective photomasks on a digital micromirror device to direct replication of a structure. By scanning a laser focus across the face of the intrinsically aligned masks, tomographic and computed data can be translated into protein‐based 3D reproductions with submicrometer feature sizes within 1 min. This straightforward and highly versatile approach may provide improved routes for the development of 3D cellular scaffolds, rapid prototyping of microanalytical devices, and production of custom tissue replacements.
Cameo: an alternative model of concurrency for Eiffel
Authors: Brooke Phillip J. , Paige Richard F.
Published: November 2008

We present a new concurrency model for the Eiffel programming language. The model is motivated by describing a number of semantic problems with the leading concurrency model for Eiffel, namely SCOOP. Our alternative model aims to preserve the existing behaviour of sequential programs and libraries wherever possible. Comparison with the SCOOP model is made. The concurrency aspects of the alternative model are presented in CSP along with a model of exceptions. The results show that while the new model provides increased parallelism, this comes with the price of increased overhead due to lock management.
Estimating number of families for an urban fox population by using two public data sets
Authors: Uraguchi Kohji , Yamamura Kohji , Saitoh Takashi
Published: November 2008

The number of families in the urban fox population of Sapporo, Japan, was estimated from two sets of data reported by the public to government: records of road‐killed foxes (information‐A) and records of complaints about foxes (information‐B). We assumed that fox populations consist of families that have exclusive home ranges, i.e., territories, during the period between gestation and dispersal. The urban area was then divided into hexagons that correspond to the territories. The locations from the two sets of records during the territorial period were plotted on the map. The number of fox families for which information‐A and/or B was reported was estimated by counting the number of hexagons that include the record. The total number of families was estimated by using a double‐observation method. We adopted Chapman's unbiased estimator which is based on the hypergeometric distribution that corresponds to the conditional likelihood. We demonstrated the possibility of estimating the abundance of animals from government data such as road kill and complaints if the animals have territories.
Hurricane Katrina: Was There a Political Economy of Death?
Authors: Price Gregory N.
Published: November 2008

An empirical implication of egalitarianism in the provision of public disaster relief services is that the probability of surviving a natural disaster should not be conditioned on a household's position in the income distribution, or its racial characteristics. In this paper, we utilize data on deaths attributed to Hurricane Katrina in the City of New Orleans to estimate a political economy model of the public provision of disaster rescue services. Parameter estimates reveal that the probability of dying as a result of Hurricane Katrina, at both the census tract and individual level, increased with respect to being black and poor. Our results suggest that there was a departure from egalitarian principles in the provision of public disaster rescue services during Hurricane Katrina, and are consistent with a political economy of race and class governing decisions about the allocation of public resources to ameliorate population environmental risks.
Molecular mechanism of agonist recognition by the ligand‐binding core of the ionotropic glutamate receptor 4
Authors: Kasper Christina , Frydenvang Karla , Naur Peter , Gajhede Michael , Pickering Darryl S. , Kastrup Jette Sandholm
Published: November 2008

The α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) class of ionotropic glutamate receptors comprises four different subunits: iGluR1/iGluR2 and iGluR3/iGluR4 forming two subgroups. Three‐dimensional structures have been reported only of the ligand‐binding core of iGluR2. Here, we present two X‐ray structures of a soluble construct of the R/G unedited flip splice variant of the ligand‐binding core of iGluR4 (iGluR4i(R)‐S1S2) in complex with glutamate or AMPA. Subtle, but important differences are found in the ligand‐binding cavity between the two AMPA receptor subgroups at position 724 (Tyr in iGluR1/iGluR2 and Phe in iGluR3/iGluR4), which in iGluR4 may lead to displacement of a water molecule and hence points to the possibility to make subgroup specific ligands.
Pyridine as novel substrate for regioselective oxygenation with aromatic peroxygenase fromAgrocybe aegerita
Authors: Ullrich René , Dolge Christoph , Kluge Martin , Hofrichter Martin
Published: November 2008

Agrocybe aegeritaperoxidase (AaP) is a versatile extracellular biocatalyst that can oxygenate aromatic compounds. Here, we report on the selective oxidation of pyridine (PY) yielding pyridineN‐oxide as sole product. Using H218O2as co‐substrate, the origin of oxygen was confirmed to be the peroxide. Therefore, AaP can be regarded as a true peroxygenase transferring one oxygen atom from peroxide to the substrate. To our best knowledge, there are only two types of enzymes oxidizing PY at the nitrogen: bacterial methane monooxygenase and a few P450 monooxygenases. AaP is the first extracellular enzyme and the first peroxidase that catalyzes this reaction, and it converted also substituted PYs into the correspondingN‐oxides.
Endogenous microRNAs induced by heat‐shock reduce myocardial infarction following ischemia–reperfusion in mice
Authors: Yin Chang , Wang Xiaoyin , Kukreja Rakesh C.
Published: November 2008

We investigated the role of microRNAs (miRNA) in protection against ischemia/reperfusion (I/R) injury in heart. Mice subjected to cytoprotective heat‐shock (HS) showed a significant increase of miRNA‐1, miRNA‐21 and miRNA‐24 in the heart. miRNAs isolated from HS mice and injected into non‐HS mice significantly reduced infarct size after I/R injury, which was associated with the inhibition of pro‐apoptotic genes and increase in anti‐apoptotic genes. Chemically synthesized miRNA‐21 also reduced infarct size, whereas a miRNA‐21 inhibitor abolished this effect. Overall, these studies for the first time provide evidence for the potential role of endogenously synthesized miRNA's in cardioprotection following I/R injury.
The effect of UCP3 overexpression on mitochondrial ROS production in skeletal muscle of young versus aged mice
Authors: Nabben Miranda , Hoeks Joris , Briedé Jacob J. , Glatz Jan F.C. , Moonen-Kornips Esther , Hesselink Matthijs K.C. , Schrauwen Patrick
Published: November 2008

Uncoupling protein 3 (UCP3) is suggested to protect mitochondria against aging and lipid‐induced damage, possibly via modulation of reactive oxygen species (ROS) production. Here we show that mice overexpressing UCP3 (UCP3Tg) have a blunted age‐induced increase in ROS production, assessed by electron spin resonance spectroscopy, but only after addition of 4‐hydroxynonenal (4‐HNE). Mitochondrial function, assessed by respirometry, on glycolytic substrate was lower in UCP3Tg mice compared to wild types, whereas this tended to be higher on fatty acids. State 4o respiration was higher in UCP3Tg animals. To conclude, UCP3 overexpression leads to increased state 4o respiration and, in presence of 4‐HNE, blunts the age‐induced increase in ROS production.
Does Microvascular free flap Reconstruction in oral Squamous cell Carcinoma Improve Patient Survival?
Authors: Marchetti Claudio , Pizzigallo Angelo , Cipriani Riccardo , Campobassi Angelo , Badiali Giovanni
Published: November 2008

Objective

We analyzed our experiences with microvascular reconstruction after oncologic resections for oral squamous cell carcinoma. Has microvascular surgery changed the survival rate of these patients?

Design

Retrospective study.

Subjects and Methods

Forty‐two consecutive patients enrolled from March 1999 to December 2004. Follow‐up time ranged from 1 to 94 months. Survival rates were evaluated by the Kaplan‐Meier method and compared among different groups with the use of Cox regression.

Results

The actuarial 5‐year survival rate was 41.9% (SD = 9.6%). Survival rates were also analyzed according to T, N, and stage. The survival was significantly related only to N, which showed a 72.4% increase in the risk related to the increase of one N stage.

Conclusions

A comparison between our study group and those of 3 previous similar studies would not provide definitive statistical evidence, but it could certainly suggest a trend. The comparison seems to support that microvascular free tissue transfer does not change the survival of these patients.
Lymphosonographic Sentinel node Biopsy of the Supraglottis in a Swine Model
Authors: Curry Joseph M. , Grindle Christopher R. , Merton Daniel A. , Goldberg Barry B. , Rosen David , Pribitkin Edmund A.
Published: November 2008

Objective

To test the feasibility of a novel contrast‐enhanced ultrasound (CEUS) technique, or lymphosonography, for sentinel node biopsy (SNB) of the supraglottis in a porcine model.

Study Design and Setting

In this prospective, non‐randomized animal study, blue dye and ultrasound contrast agent were injected into the supraglottis in seven 50‐kg Yorkshire swine. Transcutaneous CEUS was used to identify real‐time lymphatic flow of contrast through lymph channels (LC) to the sentinel lymph node (SLN). SNB was carried out, visually identifying a blue node, with the assistance of intraoperative CEUS. Bilateral modified radical neck dissections were performed to search for any residual contrast‐positive or blue SLNs.

Results

In each case, at least one SLN was identified by preoperative CEUS. A total of 12 nodes were identified on preoperative CEUS, and 11 of 12 nodes were stained with blue dye (91.7%). No residual blue or contrast‐positive nodes were identified on neck dissection.

Conclusions

Lymphosonographic SNB of the supraglottis in a porcine model is technically feasible, and yields results comparable to traditional blue dye–guided techniques. No “shine‐through” effect or nonsequential nodal enhancement occurred. This technique holds promise for sentinel node biopsy and allows a novel method for in vivo investigation of the lymphatic system.
A method for identification of vocal fold lamina propria fibroblasts in culture
Authors: Thibeault Susan L. , Li Wenhua , Bartley Stephanie
Published: November 2008

Objective

Vocal fold biology research is emerging as a vital area of study in laryngology. One impediment is the lack of both commercially available vocal fold lamina propria fibroblasts and a constitutively expressed specific marker for fibroblasts. We present an in vitro technique that allows for identification of fibroblasts by ruling out the possibility of the cells belonging to other lineages that are found in vocal fold tissue.

Study Design

An in vitro study.

Methods

Two primary vocal fold fibroblast cell lines and one immortalized vocal fold fibroblast cell line were cultured. Immunohistologic staining for α‐actinin, cytokeratin 19, and von Willebrand factor was completed for the three fibroblast lines in addition to skeletal, endothelial, and epithelial cell lines. Cell type was differentiated by positive staining for α‐actinin, cytokeratin 19, and von Willebrand factor.

Results

Fibroblast cultures did not express α‐actinin, cytokeratin 19, and von Willebrand factor, whereas skeletal muscle, endothelial, and epithelial cultured cells expressed each respectively.

Conclusions

This simple rule‐out methodology for fibroblast confirmation is an important step when establishing cell culture, and it establishes sound internal validity particularly in the early stages of this emerging area of study.
Toward Revitalizing the role of Physician‐Scientists in Academic Medicine
Authors: Balaban Carey D.
Published: November 2008

There has been a growing recognition over the past 25 years that it is increasingly difficult for physicians to develop careers as physician‐scientists. This commentary reviews the traditional culture of academic medicine, factors that are altering that culture, and several grassroots suggestions for revitalizing academic medicine in our departmental programs. It is based on a presentation, “Basic Scientist or Translational Scientist? Changing Roles of Physician‐Scientists in Biomedical Research,” delivered in the President's Symposium at the Thirty‐First Midwinter Meeting of the Association for Research in Otolaryngology on February 17, 2008.
Pro-competition Policy Tools and State Capacity: Corporatisation of Public Universities in Hong Kong and Singapore
Authors: Mok Ka Ho
Published: November 2008

In the last decade, the higher education systems in Hong Kong and Singapore have experienced the processes of marketisation and corporatisation. Public universities are under constant pressures to restructure themselves to become more entrepreneurial and globally competitive. The principal goal of the article is to compare and contrast how and why governments in Hong Kong and Singapore have increasingly adopted more pro-competition policy tools, especially when indirect policy instruments have become increasingly popular in governing higher education in these East Asian Tigers. The present article also examines whether and how these Asian developmental states have really reduced their capacity in managing the public sector particularly when the “liberalising and marketising trends” are more globally driving their choices and options of policy tools.
Firm Accounting Practices, Accounting Reform and Corruption in Asia
Authors: Wu Xun
Published: November 2008

Despite rapid economic growth and assiduous efforts in anti-corruption campaigns, many Asian economies continue to be plagued with rampant corruption problems; and in a number of countries, the progress towards corruption reduction has stagnated over the last decade as measured by corruption perception indices. This paper focuses on the corporate sector as the main source of corruption problems in Asia, with particular emphasis on the impact that firm accounting practices have on the level of bribery. Using a unique cross-country firm-level dataset, we examine some distinct characteristics of bribery in corporate Asia, and empirically test the relationship between firm accounting practices and bribery. Our findings suggest that better accounting practices can help reduce both the incidence of bribery activities and the amount of bribe payments, but conforming to high quality accounting standard alone will not necessarily enhance the quality of accounting practices and thus will not automatically bring down the level of bribery.
The Cambridge Companion to the Actress
Authors: Stokes John
Published: November 2008

This Companion brings together sixteen new essays which examine, from various perspectives, the social and cultural role of the actress throughout history and across continents. Each essay focuses on a particular stage in her development, for example professionalism in the seventeenth century; the emergence of the actress/critic during the Romantic period and, later on, of the actress as best selling autobiographer; the coming of the drama schools which led to today's emphasis on the actress as a highly-trained working woman. Chapters consider the image of the actress as a courtesan, as a 'muse', as a representative of the 'ordinary' housewife, and as a political activist. The collection also contains essays on forms, genres and traditions - on cross dressing, solo performance, racial constraints, and recent Shakespeare - as well as on the actress in early photography and on film. Its unique range will fascinate, surprise and instruct theatre-goers and students alike.
The Cambridge Companion to British Romantic Poetry
Authors: McLane Maureen N.
Published: November 2008

More than any other period of British literature, Romanticism is strongly identified with a single genre. Romantic poetry has been one of the most enduring, best loved, most widely read and most frequently studied genres for two centuries and remains no less so today. This Companion offers a comprehensive overview and interpretation of the poetry of the period in its literary and historical contexts. The essays consider its metrical, formal, and linguistic features; its relation to history; its influence on other genres; its reflections of empire and nationalism, both within and outside the British Isles; and the various implications of oral transmission and the rapid expansion of print culture and mass readership. Attention is given to the work of less well-known or recently rediscovered authors, alongside the achievements of some of the greatest poets in the English language: Wordsworth, Coleridge, Blake, Scott, Burns, Keats, Shelley, Byron and Clare.