bluuebunny/crossref_metadata_2025 huggingface dataset:
Metallurgical and environmental factors affecting the pitting behavior of UNS S 32205 duplex stainless steel in chloride solutions
Authors: Ezuber H. M.
Published: September 2010

The effect of temperatures up to 80 °C, dissolved CO2(sat.), and flow (agitation) up to 1000 rpm on the breakdown potential of mill‐annealed UNS S 32205 duplex stainless steel (DSS) has been evaluated in 1 M NaCl solution using potentiodynamic polarization technique. The results were compared with heat‐treated samples (furnace heated at 850 °C for 10 or 60 min followed by water quench). The aim of the heat treatment is to simulate sigma phase precipitation. The results show dependence of pitting potential on the various factors (sigma phase, test temperature, dissolved CO2(sat.), or solution flow) being studied. In general, the mill annealed or heat‐treated UNS S 32205 DSS alloys are immune to pitting at room temperature (23 °C). At 50 °C however, pitting corrosion is evident and the intensity of such attack is increased with the presence of dissolved CO2, increasing isotherm held duration and/or seawater temperature. In contrast, agitation speed of 350 rpm (Re of 12 880) or above (sufficiently to yield turbulent flow) has shifted the pitting potential to more positive values. Lower speed of 100 rpm, however, is negligibly different from the stagnant conditions.
Effect of preparation method on the anti‐corrosive properties of nanocrystalline Zn–CoO ceramic pigments
Authors: Rasouli S. , Danaee I.
Published: September 2010

Zn–CoO green ceramic pigments were synthesized by two different methods; high energy ball milling and solution combustion, with two different fuels; citric acid and glycine. Products were characterized by X‐ray diffraction and scanning–transmission electron microscopy (TEM). The anti‐corrosive properties of the obtained pigments were investigated by electrochemical impedance spectroscopy (EIS) techniques. Results have shown that either by solid state reaction or combustion by citric acid, a calcination step was needed to obtain the desired phase whereas by glycine fuel, pure ZnO phase was obtained directly. TEM showed particles with mean particle size of about 70, 150, and 180 nm for glycine, citric acid, and solid state reaction samples, respectively. The corrosion performance of the coating in 3% w/v NaCl solution was evaluated by EIS and polarization measurements. According to the measurements of EIS and electrochemical polarization, the coatings with glycine‐based pigment showed the highest corrosion resistance among the prepared coatings.
Evaluation of the corrosion inhibition of salts of organic acids in alkaline solutions and chloride contaminated concrete
Authors: Pastore T. , Cabrini M. , Coppola L. , Lorenzi S. , Marcassoli P. , Buoso A.
Published: September 2010

This paper summarizes the results of testing on salts of organic acids for evaluating their use as inhibitors of rebar corrosion in chloride‐contaminated concrete. Initially a screening based on electrochemical tests in alkalinized calcium hydroxide solutions was performed on a number of carboxylic acid salts with different number of carbon atoms in the chain and carboxylic groups, also covering substances with hydroxyl and amine group substituents. The screening was completed by testing on carbon steel rebars in concretes with chlorides and substances added at 1:1 molar ratio, focused on sodium lactate, sodium oxalate and sodium borate for comparison. The monitoring of free corrosion potential and linear polarization resistance of steel bars have confirmed significant inhibition only for lactate. Corrosion was only restricted to occluded zones where the access of substance was limited by disadvantageous geometry, producing shallow attacks.

Results of further tests in saturated calcium hydroxide solution are reported in order to assess the inhibition ability of lactate as a function of its content, chloride content and pH.
Early stage beneficial effects of cathodic protection in concrete structures
Authors: Polder R. B. , Peelen W. H. A. , Stoop B. Th. J. , Neeft E. A. C.
Published: September 2010

Over the last 25 years, cathodic protection (CP) of reinforced concrete structures suffering from chloride induced reinforcement corrosion has shown to be successful and durable. CP current causes steel polarisation, electrochemical reactions and ion transport in the concrete. CP systems are designed based on experience, which results in conservative designs and their performance is a matter of wait‐and‐see. CP systems can be designed for critical aspects and made more economical using numerical models for current and polarisation distribution. Previously, principles of numerical calculations for design of CP systems were reported. The results were satisfactory, except in terms of current density for active corroding systems. This was suggested to be due to neglecting beneficial effects of CP current flow. One of the beneficial effects is pH increase at the steel surface due to oxygen reduction. As the pH increases, the corrosion rate decreases and the current demand decreases. A simple model was set up for this transient process, suggesting that such effects should occur on the time scale of hours to days. This model was validated from start up data of a CP field trial system on part of a bridge. Field results confirmed the modelling proposed here.
Electrochemical corrosion response of a precipitation hardening moulds steel in a NaCl solution
Authors: Rosalbino F. , Scavino G. , Mortarino G.
Published: September 2010

Investigations concerning the electrochemical corrosion behavior of mould steels are scarce and limited. In the present study, the corrosion resistance of a precipitation hardening moulds steel submitted to aging treatments has been assessed in a 0.1 M NaCl aqueous solution by means of potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The electrochemical characterization of the steel not submitted to hardening treatments was also examined and a comparative study was made between the different specimens. Scanning electron microscopy and electron probe microanalysis were used to obtain information about the morphology and chemical composition of the steels surface after the electrochemical tests. Increasing the aging temperature an increase of secondary hardness is observed, attributable to an increase of secondary phases (re‐precipitated carbides and metastable GP zones) amount, positively reflecting on the mechanical properties. However, the electrochemical results show a progressive worsening of the corrosion behavior, the as‐received steel sample exhibiting the best corrosion resistance. The observed decrease of corrosion resistance with increasing the aging temperature is ascribed to enhanced galvanic coupling phenomena between the secondary phases, acting as cathodes, and the surrounding matrix which, consequently, experiences preferential dissolution.
3D‐QSAR Studies on C24‐Monoalkylated Vitamin D3 26,23‐Lactones and their C2α‐Modified Derivatives with Inhibitory Activity to Vitamin D Receptor
Authors: Wang Jinhu , Tang Ke , Hou Qianqian , Cheng Xueli , Dong Lihua , Liu Yongjun , Liu Chengbu
Published: September 2010

The ligand‐based three‐dimensional quantitative structure‐activity relationship (3D‐QSAR) for 82 inhibitors of 25‐dehydro‐1α‐hydroxyvitamin D3‐26,23‐lactone analogs has been studied by using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models. The established CoMFA model in training set gives a cross‐validated q2 value of 0.516 and a non‐cross‐validated rncv2 value of 0.667, while the CoMSIA model results in q2=0.517 and rncv2=0.632. In general, the predictive ability of the CoMFA model is superior to that of the CoMSIA model, with rpred2=0.639 for the CoMFA and rpred2=0.619 for the CoMSIA model. Based on the CoMFA contour maps, some key structural characters of vitamin D3 analogs responsible for inhibitory activity are identified, and some new C2α‐modified 24‐alkylvitamin D3 lactone analogs with high predicted pIC50 values are designed. The ligand functional group mutations by FEP simulation and docking studies reveal the rationality of the molecular design.
QSPR Analysis of Copolymers by Recursive Neural Networks: Prediction of the Glass Transition Temperature of (Meth)acrylic Random Copolymers
Authors: Bertinetto Carlo Giuseppe , Duce Celia , Micheli Alessio , Solaro Roberto , Tiné Maria Rosaria
Published: September 2010

The glass transition temperature (Tg) of acrylic and methacrylic random copolymers was investigated by means of Quantitative Structure‐Property Relationship (QSPR) methodology based on Recursive Neural Networks (RNN). This method can directly take molecular structures as input, in the form of labelled trees, without needing predefined descriptors. It was applied to three data sets containing up to 615 polymers (340 homopolymers and 275 copolymers). The adopted representation was able to account for the structure of the repeating unit as well as average macromolecular characteristics, such as stereoregularity and molar composition. The best result, obtained on a data set focused on copolymers, showed a Mean Average Residual (MAR) of 4.9 K, a standard error of prediction (S) of 6.1 K and a squared correlation coefficient (R2) of 0.98 for the test set, with an optimal rate with respect to the training error. Through the treatment of homopolymers and copolymers both as separated and merged data sets, we also showed that the proposed approach is particularly suited for generalizing prediction of polymer properties to various types of chemical structures in a uniform setting.
Patient satisfaction with the benefits of overactive bladder treatment: Exploration of influencing factors and development of a satisfaction assessment instrument
Authors: Zinner Norman , Kobashi Kathleen , Koochaki Patricia , Fix Deborah , Egermark Mathias
Published: September 2010

Introduction

Patient‐reported outcome (PRO) instruments are useful for assessing treatment success in patients with overactive bladder (OAB). PROs such as the OAB Questionnaire (OAB‐q) and Patient Perception of Bladder Condition (PPBC) focus more on OAB symptoms than satisfaction. We describe the development of the Patient Satisfaction with Treatment Benefit (PSTB) questionnaire, and examine the face, content and criterion validity of this tool in a study of darifenacin treatment in OAB patients who expressed dissatisfaction with prior antimuscarinic therapy.

Methods

The PSTB questionnaire was created based on treatment‐related items identified as relevant to OAB patients in exploratory interviews, then refined to comprise an Overall Satisfaction question and 23 items addressing specific treatment benefits using a 5‐point Likert scale. The PSTB questionnaire was completed at last visit by 473 patients participating in an open‐label, 12‐week study of darifenacin treatment. Factors driving Overall Satisfaction were explored by investigating its relationship to PPBC, bladder symptom diaries and specific benefits assessed by the PSTB.

Results

At study end, mean Overall Satisfaction score was 3.1, corresponding to “satisfied.” Overall Satisfaction correlated strongly with each specific benefit in the PSTB, and with PPBC and OAB symptoms at last visit, but more weakly with change from baseline PPBC/symptoms. Satisfaction at last visit was higher for patients with mild/moderate versus severe problems on baseline PPBC.

Conclusions

Patients' reported satisfaction appears to reflect their current status rather than improvement over time. The PSTB tool may have a place alongside other symptom‐based instruments. Further testing is required to validate these findings. Neurourol. Urodynam. 30:62–68, 2011. © 2010 Wiley‐Liss, Inc.
Type and severity of new‐onset urinary incontinence in middle‐aged women: The Hordaland women's cohort
Authors: Jahanlu David , Hunskaar Steinar
Published: September 2010

Aims

To determine the natural history of new‐onset urinary incontinence by type and severity in middle‐aged women.

Methods

In 1997‐1999 2229 randomly selected women aged 41‐45 agreed to participate in the Hordaland Women's' Cohort, and six identical postal questionnaires were sent them during the following ten years. Response rate was 95.7% at inclusion and has remained 87% to 93% in subsequent waves. A total of 1274 women were continent at baseline and used as source population for this paper. Distribution of type and severity of new‐onset urinary incontinence and changes in these variables during four years follow‐up (two checkpoints) were measured.

Results

Among 1274 continent women, 514 (40.3%) reported new‐onset urinary incontinence during 10 years. Type distribution was 49.8%, 18.3% and 20.3% for stress, urgency and mixed incontinence, respectively. A majority of women (89.3%) started with slight urinary incontinence and none reported severe new‐onset urinary incontinence. During four years follow‐up of 337 women, 212 (62.9%) reported transient and 125 (37.1%) women reported persistent urinary incontinence. In the latter group 74.6% had the same type of urinary incontinence and 62.4% reported slight grade of incontinence in all reports.

Conclusions

Our study demonstrates that in middle‐aged women new‐onset urinary incontinence is mainly of stress type and of slight severity. One third of the women developed persistent incontinence, with low tendency of shifting type and severity over several years. Mixed urinary incontinence is not a final stage of incontinence in this age group. Neurourol. Urodynam. 30:87–92, 2011. © 2010 Wiley‐Liss, Inc.
Minor anomalies in children with hematological malignancies
Authors: Citak Funda Erkasar , Citak Elvan Caglar , Akkaya Emel , Kosan Bekir , Ezer Ustun , Kurekci Ahmet Emin
Published: September 2010

Background

Despite the presence of reports on correlation between major congenital defects and cancer, very few studies have investigated the frequency of minor anomalies in childhood malignancy. The aim of this study was to determine the prevalence of minor anomalies in children with hematological malignancy.

Procedure

A total of 62 well‐defined minor anomalies were determined in 109 patients. The patients were compared with age‐ and sex‐matched healthy control subjects.

Results

The results of this study showed that, 64.22% of the patients and 26.6% of the controls had at least one minor anomaly. Among the minor anomalies detected, pigmented nevi and café‐au‐lait spots were significantly more frequent in the patients. The prevalence of minor anomalies in the patients was significantly higher than that of the controls in the present study.

Conclusion

Our results contribute to the understanding of the role of genetic factors in childhood hematological malignancies. Future studies may be directed toward identifying the developmental pathways and the relevant genes that are involved in the overlap between childhood hematological malignancies and minor anomalies. Pediatr Blood Cancer 2011;56:258–261. © 2010 Wiley‐Liss, Inc.
Phase 1 trial and pharmacokinetic study of the farnesyl transferase inhibitor tipifarnib in children and adolescents with refractory leukemias: A report from the Children's Oncology Group
Authors: Widemann Brigitte C. , Arceci Robert J. , Jayaprakash Nalini , Fox Elizabeth , Zannikos Peter , Goodspeed Wendy , Goodwin Anne , Wright John J. , Blaney Susan M. , Adamson Peter C. , Balis Frank M.
Published: September 2010

Background

The objectives of this trial were to define the toxicity profile, dose, pharmacokinetics, and pharmacodynamics of the farnesyl transferase (FTase) inhibitor, tipifarnib, in children and adolescents with hematological malignancies.

Procedure

Tipifarnib was administered twice daily for 21 days, repeated every 28 days starting at a dose of 300 mg/m2/dose. Pharmacokinetic sampling was performed for 36 hr after the first dose and leukemic blasts were collected pre‐treatment and at steady state for determination of FTase activity.

Results

Of 29 patients enrolled, 18 were fully evaluable for toxicity, and 23 for response; 26 had pharmacokinetic and pharmacodynamic sampling. The recommended dose is 300 mg/m2/dose and toxicities included skin rash, mucositis, nausea, vomiting, and diarrhea. Neurotoxicity, which was dose‐limiting in adults at doses exceeding 600 mg/dose, was infrequent and mild. The plasma pharmacokinetics of tipifarnib were highly variable but comparable to adults with acute leukemia and children with solid tumors. The median apparent clearance of tipifarnib was 630 ml/min/m2 and the median half‐life was 4.7 hr. At steady state on 300 mg/m2/dose, FTase activity was inhibited by 82% in leukemic blasts. No objective responses were observed.

Conclusions

Oral tipifarnib is well tolerated in children with leukemia on a twice daily for 21days schedule at 300 mg/m2/dose. Pediatr Blood Cancer 2011;56:226–233. © 2010 Wiley‐Liss, Inc.
Preparation of amidoximated poly(glycidyl methacrylate) microbeads
Authors: Caykara Tuncer , Çakar Ferhat , Demirci Serkan
Published: September 2010

Poly(glycidyl methacrylate) (PGMA) microbeads were synthesized by a simple suspension polymerization of glycidyl methacrylate and ethylene glycol dimethacrylate. The epoxy groups of the microbeads were firstly modified with 3,3′‐iminodipropionitrile (IDPN) and the resulting nitrile groups were then converted to amidoxime. From scanning electron microscopy studies, the average size of the PGMA microbeads was determined as 170 µm, which was not changed by the modification processes. For the modification of epoxy groups with IDPN, the intensity of the C≡N absorption band at 2249 cm−1 increased proportionally with reaction time; for the conversion of nitrile groups to amidoxime, it decreased. Attenuated total reflectance Fourier transform infrared spectroscopy measurements clearly showed the disappearance of the original nitrile groups and the formation of amidoxime groups through treatment with hydroxylamine under the reaction conditions specified. The microbeads possessed good thermal and morphological properties and chemical stability suitable for practical use. Therefore, the amidoximated PGMA microbeads could be used in batch and continuous processes for the adsorption of uranyl ions from seawater or aqueous media. Copyright © 2010 Society of Chemical Industry
Synthesis of pH‐ and temperature‐responsive chitosan‐graft‐poly[2‐(N,N‐dimethylamino) ethyl methacrylate] copolymer and gold nanoparticle stabilization by its micelles
Authors: Yuan Weizhong , Zhao Zhengda , Yuan Jinying , Gu Shuying , Zhang Fengbo , Xie Xuming , Ren Jie
Published: September 2010

Novel pH‐ and temperature‐responsive chitosan‐graft‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate] (chitosan‐g‐PDMAEMA) copolymers were successfully synthesized by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Chitosan macroinitiator was prepared by phthaloylation of amino groups of chitosan and subsequent acylation of hydroxyl groups of chitosan with 2‐bromoisobutyryl bromide. The copolymers were obtained by ATRP of 2‐(N,N‐dimethylamino)ethyl methacrylate and they can self‐assemble into stable micelles in water. Hybrid micelles with a PDMAEMA corona incorporating gold nanoparticles (Au NPs) were prepared in situ via the reduction of HAuCl4 with NaBH4. The pH and temperature responses of the copolymer micelles and hybrid micelles were characterized using UV‐visible spectroscopy and dynamic laser light scattering. The morphology of the micelles was observed using transmission electron microscopy and atomic force microscopy. The PDMAEMA corona of the micelles acts as the ‘nanoreactor’ and the ‘anchor’ for the in situ formation and stabilization of Au NPs. Therefore, the spatial distribution of Au NPs within the micelles can be tuned by varying the temperature and pH value. Copyright © 2010 Society of Chemical Industry
Thermal Behavior of Nitrocellulose with Inorganic Salts and their Mechanistic Action
Authors: Katoh Katsumi , Higashi Eiko , Nakano Katsuyuki , Ito Shunsuke , Wada Yusuke , Kasamatsu Junichi , Miya Hiroshi , Yamamoto Masaaki , Wada Yuji
Published: September 2010

In this study, we investigated the effects of inorganic salts on the stability of NC and its reaction mechanism. Under isothermal conditions at 120 °C in an O2 atmosphere, the induction time period for NC heat release was prolonged in the presence of Li2CO3, Na2CO3, CaCO3, Mg(OH)2, Ca(OH)2, and MgO, all of which produce alkaline saturated solutions with a pH value of 10–12. In addition, the induction time period depended on this pH value. This suggests that these salts stabilized NC by neutralizing acids that would otherwise accelerate the hydrolysis of the O‐NO2 bond. However, Sr(OH)2 ⋅ 8H2O and K2CO3, which produce strongly alkaline saturated solutions with pH>13, decreased the induction time period. It is possible that these strong bases caused alkaline decomposition of NC. In addition, for Sr(OH)2 ⋅ 8H2O, the released water of crystallization appeared to be related to NC destabilization. SrCO3, NaHCO3, K2SO4, CaSO4, ZnSO4, NaCl, CaCl2, AgCl, and NaNO2, which produce near‐neutral saturated solutions, slightly decreased the NC induction time period. The NC induction time period with these salts depended upon the solubility of the added salt. This may indicate that in the presence of these inorganic salts, the boiling point of water is increased, which reduces the vaporization of water from NC and thus accelerates the hydrolysis of NC.
Knudsen Effusion Measurement of Organic Peroxide Vapor Pressures
Authors: Damour Paul L. , Freedman Andrew , Wormhoudt Joda
Published: September 2010

The vapor pressures of TATP over the temperature range 269.85–306.95 K and DADP over the temperature range 265.85–294.85 K were determined using a modified Knudsen effusion apparatus. The Clausius‐Clapeyron plot of log10(p(Pa)) with 1/T provided a straight line for each material. This expression for TATP is log10(p(Pa))=−(4497±80)/T(K)+(15.86±0.28) (error limits are 95 % confidence limits) and for DADP it is log10(p(Pa))=−(4417±137)/T(K)+(16.31±0.48). These expressions yield values of the vapor pressure at 298.15 K of 6 Pa for TATP and 17 Pa for DADP, and heats of sublimation of 86.2±1.5 kJ mol−1 for TATP and 84.6±2.6 kJ mol−1 for DADP. Attempts were made to determine the vapor pressure of HMTD but it appears to have a vapor pressure too low for our system to reliably determine. A two month experiment did provide an upper limit estimate for the vapor pressure of HMTD of approximately 0.04 Pa at room temperature. Melting point and melting point range were used as verification of the identity and purity of the TATP and DADP used in these experiments, but this was not possible with HMTD since it detonates prior to melting.
Increasing the Utility of the Copper Cylinder Expansion Test
Authors: Lindsay C. Michael. , Butler George C. , Rumchik Chad G. , Schulze Ben , Gustafson Ryan , Maines Warren R.
Published: September 2010

We report the development of a new methodology for analyzing CYLEX tests streak images. In these tests, the displacement of the wall of an explosive filled cylinder is obtained by backlighting the cylinder. The profile is imaged through a slit and streaked across a film record as the cylinder is detonated. A critical step in processing this data is the spatial calibration of the film and extraction of the profile of the cylinder from the image. Historically this has been a tedious task as it was performed by eye with the assistance of an optical comparator. Recently we developed an algorithm which automates the data calibration and extraction process of digitized streak records utilizing the Shen‐Castan edge detection algorithm and the image processing capabilities found in the IGOR PRO software. The new processing methodology greatly increases the resolution of the data, removes human subjectivity, and reduces analysis time from hours to seconds. The higher resolution of the new method has enabled much greater accuracy in measuring early‐time (<15 µs) expansion. With the aid of CTH hydrocode calculations, new fitting functions were developed to model both the early and late‐time expansion data. These functions contain physically meaningful fitting parameters and include terms which mimic the intensity and time scales of the shock and gas induced expansion of the cylinder independently. We demonstrate the methodology and hydrocode calculations on a recent CYLEX test series aimed at examining the effects of a plastic liner on high‐purity oxygen‐free copper cylinders filled with a high explosive.
Semiochemicals of the common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), and their potential for use in monitoring and control
Authors: Weeks Emma NI , Birkett Mike A , Cameron Mary M , Pickett John A , Logan James G
Published: September 2010

The recent resurgence of the common bed bug, Cimex lectularius L., has driven an increase in research into the biology and behaviour of this pest. Current control is reliant on the application of insecticides, but, owing to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour‐ and physiology‐modifying chemicals) could be exploited for management of bed bugs. The aim of this review was to evaluate studies undertaken in bed bug chemical ecology to date, with particular reference to how the research could be exploited for monitoring and control. Bed bugs, like many other insects, have a complex olfactory system. Recent studies have characterised the olfactory sensilla, located on the terminal segment of the antennae, to functional classes by electrophysiological screening. Behavioural studies have revealed the presence of an alarm pheromone and potential airborne aggregation semiochemicals, but it is not yet understood if bed bugs use a sex pheromone during mating. Host location cues have been investigated, and carbon dioxide has been found to be highly attractive both in laboratory and in field studies. Recent field trials have tested blends of other potential kairomones, which have been shown to have an additive effect when used in a heated bed bug trap with carbon dioxide. The trap, which combines heat and kairomones, is the only trap currently available with proven efficacy in the field. In order for semiochemicals to be useful for bed bug management, an increased knowledge and understanding of the biology, behaviour and chemical ecology of this insect is essential. Copyright © 2010 Society of Chemical Industry
Chirality dependence of the dielectric constant for the excitonic transition energy of single‐wall carbon nanotubes
Authors: Araujo P. T. , Nugraha A. R. T. , Sato K. , Dresselhaus M. S. , Saito R. , Jorio A.
Published: September 2010

Attention has been devoted recently to understand the physics behind the dielectric screening of the carbon nanotube optical transitions (Eii), including how a changing environment changes Eii. It was shown that the environmental screening could be modeled by an effective diameter dependent dielectric constant κ, which takes into account contributions from the single‐wall carbon nanotube (SWNT) itself and from the environment surrounding the tube. Here we consider the chiral angle (θ) dependence of κ which improves the previous fitting by only the diameter dependence and we can now see the difference between $E_{11}^{M} $ and $E_{22}^{S} $ by the present treatment. In this work we used the “alcohol‐assisted” and the “super‐growth” SWNT samples to address this point.
Polarised Raman measurements of β‐carotene encapsulated in SWNTs
Authors: Brose Katharina , Tschirner Norman , Zouni Athina , Müh Frank , Yanagi Kazuhiro , Kataura Hiromichi , Thomsen Christian , Maultzsch Janina
Published: September 2010

The knowledge of the vibrational properties is of key importance to understand their function of β‐carotene molecules in the reaction centre of the light‐harvesting complexes. We present polarisation‐dependent Raman spectroscopy on β‐carotene molecules in two different environments: first single dimeric photosystem II crystal, and second encapsulated β‐carotene in single‐wall carbon nanotube bundles. Both systems have nearly perpendicular or parallel orientated β‐carotene molecules. We compare the dependence of their Raman spectra on the polarisation of incident and scattered light.
Size dependence of the magnetic response of graphite oxide and graphene flakes – an electron spin resonance study
Authors: Ćirić Luka , Sienkiewicz Andrzej , Djokić Dejan M. , Smajda Rita , Magrez Arnaud , Kaspar Tommy , Nesper Reinhard , Forró László
Published: September 2010

We employed electron spin resonance (ESR) technique in the investigation of a series of graphene flakes with different size distributions. Graphene oxide (GO) samples with three distinct size distributions were prepared by the Brodie method. Large flakes of ∼2500 µm2, intermediate size flakes of ∼1 µm2, and small ones of ∼500 nm2 have been characterized by ESR in the 4–295 K temperature range. Already for GO flakes the magnetic response strongly varies with their size. Large GO flakes are inhomogeneous, revealed by the presence of both Pauli and Curie components in the overall signal. In small GO flakes ESR spin susceptibility reveals superparamagnetic behavior ascribed to interaction between localized spins. The intermediate flakes show a standard Curie behavior showing a uniform oxidation and the concomitant non‐interacting localized spins. On this batch a thermal method of reduction was applied such that in polar solvent the suspension of GO was heat treated at temperatures below 200 °C. ESR susceptibility shows that this reduction can recover some of the Pauli‐like contribution of the pristine graphene. However, our study shows that the full optimization of oxidation/reduction parameters is yet to be achieved.
Temperature dependence of first‐ and second‐order Raman scattering in silicon nanowires
Authors: Khachadorian S. , Scheel H. , Colli A. , Vierck A. , Thomsen C.
Published: September 2010

The first‐ and second‐order Raman scattering of the silicon nanowires grown without any metal catalyst is studied in the temperature range from 77 to 873 K. The first‐ and second‐order Raman peaks were found to shift and broaden differently with increasing temperature. We show that this is due to the confinement related enhanced anharmonic effects in silicon nanowires. Our measurements also show that both the second‐ to first‐order Raman peak intensity ratio [I(2TA)int./I(1TO)int. and I(2TO)int./I(1TO)int.] and the Raman relative intensities [I(2TA)int./I(2TO)int.] increase with increasing temperature.

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TEM image of SiNWs. The SiNW are 15 nm in diameter and up to a few microns long.
Synthesis and functionalization of chalcogenide nanotubes
Authors: Tahir Muhammad Nawaz , Yella Aswani , Sahoo Jugal Kishore , Annal‐Therese Helen , Zink Nicole , Tremel Wolfgang
Published: September 2010

New synthetic approaches to MS2 (M = Sn, Nb, Mo, W) chalcogenide nanostructures are highlighted. Most chalcogenide particles can be functionalized directly with inorganic nanoparticles such as Au, ZnO or MnO. Depending on the Pearson hardness of the metal involved, the functionalization may be reversible or irreversible. A covalent functionalization strategy is based on a steric shielding of the coordination sphere of transition metal atoms in such a way that only coordination sites are available for bonding to the chalcogenide surface. This allows the immobilization of fluorophors, redox active groups or proteins onto chalcogenide nanoparticle.

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Auxeticity of cubic materials under pressure
Authors: Brańka A. C. , Heyes D. M. , Wojciechowski K. W.
Published: September 2010

The global maximum and global minimum Poisson's ratio (PR) surfaces, regions of different auxetic behaviour and the domains of the different extreme directions of cubic materials are shown and discussed in terms of the elastic moduli ratios, $X = G/K,Y = G/W$, where K is the bulk modulus and $G,W$ are shear moduli. A straightforward way is given to classify any cubic material as being auxetic, nonauxetic and partially auxetic, as well as calculating its extreme PR values. A decomposition of the XY plane with the elastic constant ratio ${\lambda} = C_{12} /C_{44} $ is introduced to facilitate the interpretation of cubic materials under hydrostatic pressure, $P> 0$, and isotropic tension, $P< 0$, which are two qualitatively different situations. Using this representation it is demonstrated that cubic materials with ${\lambda} > 0$ can be auxetic only under ‘negative’ pressure ($P< 0$). It is shown that the influence of pressure on the auxetic behaviour is different for the positive and negative ${\lambda} $ cases. In particular, a cubic material with $0> {\lambda} > {-} 1$ may be auxetic at negative as well as positive pressure. The work demonstrates the crucial role of P in obtaining desired auxetic behaviour. Microscopic mechanisms which tune the cubic system to targeted regions in the XY plane are investigated with a fcc crystal of particles interacting via the pairwise spherically symmetric potential, ${\phi} (r)$. It is found that all fcc static models in which the range of interaction is only between nearest neighbour particles are placed on a universal curve in the XY plane. It is shown that auxetic behaviours can be achieved with simple static ${\phi} (r)$ analytic forms. The influence of the next neighbour interactions on the universal curve is also considered. In order to assess the role of thermal fluctuations, molecular dynamic simulations for two different ${\phi} (r)$ (the Lennard–Jones (LJ) and the tethered particle potentials) were performed. At low temperatures the studied systems are well represented by the universal curve and on increasing temperature a systematic departure from it is observed.
Unusual deformation mechanisms in carbon nanotube heterojunctions (5,5)–(10,10) under tensile loading
Authors: Scarpa F. , Narojczyk J. W. , Wojciechowski K. W.
Published: September 2010

The Poisson's ratio effect of single wall carbon nanotube heterojunctions (HJ) of the type (5,5)–(10,10) is investigated using an hybrid finite element atomistic‐continuum approach to simulate the mechanical behaviour of nanostructures. The nanotube HJs provide a peculiar deformation pattern, with combined bending and axial stretching of carbon nanotubes (CNTs), and a broad agreement of their axial stiffness with spring series continuum mechanics and existing molecular dynamics (MD) simulations. A possible auxetic behaviour is observed for the pure HJ with no tubes when subjected to tensile loading.
Flexible resistance memory devices based on Cu/ZnO:Mg/ITO structure
Authors: Shi Lei , Shang Da‐Shan , Sun Ji‐Rong , Shen Bao‐Gen
Published: September 2010

Resistance memory devices based on a Cu/Mg‐doped ZnO/indium‐tin‐oxide structure on a PET (polyethylene terephthalate) flexible substrate were fabricated. The devices showed stable bipolar resistance switching property and good flexibility. The high to low resistance ratio was larger than 30 times, the endurance was more than 102 cycles, and the resistance retention was longer than 104 s. The resistance values of both high and low resistance states were not significantly changed by bending in a radius (≥20 mm) for more than 103 times. This resistance switching phenomenon of our devices can be explained by creation/rupture of metal conductive channels induced by electrochemical migration of Cu ions. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Learning in the Field: Using Community Self Studies to Strengthen Forest‐Based Social Movements
Authors: Taylor Peter Leigh , Cronkleton Peter , Barry Deborah
Published: September 2010

State devolution has combined with social movement pressures to give communities increasing access and rights to southern forests, making development of effective local participation in sustainable resource management crucial. This paper discusses an experience of participatory research in Central America, which sought to help two grassroots forest organizations, the Association of Forest Communities of Petén, Guatemala and the Farmer to Farmer Programme of Siuna, Nicaragua, to respond to new organizational and political challenges by developing their internal capacity for research and analysis. Community‐based ‘para‐professional’ social researchers were trained to carry out studies of their communities' experiences with natural resource management, including strengths, problems and possible response strategies. The collaborative research initiative also encountered problems of inequality, uneven education and skills and concerns with validity. The results of this experience indicate that with appropriate support, community‐based research and researchers can help engender collective reflection, strengthen local organizational capacity and contribute knowledge and analysis in support of forest community movements' efforts to promote local resource rights and more sustainable development. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Comments on Brodie and Post: Climate‐driven declines in wolverine populations: causal connection or spurious correlation?
Authors: McKelvey Kevin S. , Lofroth Eric C. , Copeland Jeffrey P. , Aubry Keith B. , Magoun Audrey J.
Published: September 2010

The recent paper by Brodie and Post (“Nonlinear responses of wolverine populations to declining winter snowpack”, Popul Ecol 52:279–287, 2010) reports conclusions that are unsupportable, in our opinion, due to both mis‐interpretations of current knowledge regarding the wolverine's (Gulo gulo) association with snow, and the uncritical use of harvest data to index wolverine populations. The authors argue that, because the wolverine is a snow‐dependent species, average annual provincial snowfall, based on weather station data, can be expected to correlate strongly and positively with wolverine population numbers, which in turn can be accurately indexed by trapper harvests. Thus, correlations between declines in wolverine harvests and declining average snowpack are interpreted to reflect a climate‐driven decrease in wolverine populations. This conclusion overstates the nature of the wolverine's association with snow, and makes unsupportable assumptions about the reliability of harvest data as a proxy for population size.
Are exotic invaders less susceptible to native predators? A test using native and exotic mosquito species in New Zealand
Authors: Zuharah Wan Fatma , Lester Philip John
Published: September 2010

A major hypothesis in invasion ecology is that native predators have less impact on exotic relative to native prey species. Here, we tested this hypothesis by examining the New Zealand native predatorAnisops wakefieldiconsuming native (Culex pervigilans) and exotic (Aedes notoscriptus) mosquito larvae.Anisops wakefieldiexhibited a decelerating type II functional response for both prey species, but at high prey densities consumed more of the exotic mosquitoAe. notoscriptus. A significantly higher attack rate was observed for the native predator feeding on exotic species. In the presence of both prey species, the predator showed preferences towardsAe. notoscriptusand demonstrated switching behavior towards this exotic species. The preference of the native predator towards the exotic mosquito appeared related to behavioral differences between the two prey species. We tested the behavioral response of both mosquito species in four conditions; (1) control (without predators), (2) free‐roaming predators, (3) caged predators, and (4) kairomones only. Resting activities at the water surface and wall positions were the most frequently behaviors exhibited byCx. pervigilansin the presence of predator. In contrast, the exotic speciesAe. notoscriptusdemonstrated significantly higher levels of “thrashing” behaviors, apparently making itself more obvious to the predators. The behaviors showed byCx. pervigilansfulfilled the “threat sensitivity hypothesis”. No evidence here supported the idea that exotic mosquito species are less prone to the influence of native predators and the “escape from natural enemies” hypothesis seems not apply in our study. In fact, we observed that this invader was more susceptible to the predator.
Understanding Student Complaints in the Service Learning Pedagogy
Authors: Rosing Howard , Reed Susan , Ferrari Joseph R. , Bothne Nancy J.
Published: September 2010

This study draws upon student evaluations across 3 years of service learning (SL) courses at a large, urban, faith‐based university identifying issues of greatest concern to students. Analysis of qualitative responses revealed perspectives on the limits, pitfalls, and barriers to successful SL student work in the community replicated over the 3 year timeframe. Over 2,200 written responses were coded and tested for reliability for each of 3 years. The top three comments SL students were most likely to express included: (1) concern about their placement in the community, for example, that sites were not prepared or that further goal‐setting, communication and training by the university was necessary; (2) that the university's choice of sites may have been ill considered; and, (3) that there were problems with time and scheduling. Ongoing assessment of students' perspectives on their placement experience identifies practices that can enhance their learning and contributions toward building stronger communities.
Physico‐Chemical Analysis, NMR Spectroscopy and Gas Chromatographic Studies of Jatrophacurcas L. Germplasm
Authors: Bhagat Rani B. , Taware S. P. , Chavan A. M. , Kulkarni D. K.
Published: September 2010

A systematic collection of Jatropha curcas germplasm was carried out from five distinct ecogeographic zones of peninsular India in 2008. This involved recording passport data, documentation of important plant traits in situ, ecogeographic parameters and assessment of variability in 82 accessions. Extraction of oil was done by the Soxhlet method which gave an average yield of 38%. Oil content of collected accessions was determined by nuclear magnetic resonance and Soxhlet extraction. Oil variability ranged from 45.5% in JC‐8 to 11.5% in JC‐30. The level of unsaturated fatty acid ranged from 85% in JC‐57 to 75.5% in JC‐10. Saturated fatty acids ranged from 24% in JC‐43 to 15% in JC‐54, the oxidative stability index was highest at 2.1 in JC‐30 and lowest at 0.68 in JC‐17. The seed weight was greatest in JC‐8 and the lowest in JC‐30. This paper provides information that will facilitate the selection of promising accessions for genetic enhancement of Jatropha germplasm through conventional breeding.
The effect of time intervals on neonatal outcome in elective cesarean delivery at term under regional anesthesia
Authors: Maayan‐Metzger Ayala , Schushan‐Eisen Irit , Todris Liat , Etchin Abba , Kuint Jacob
Published: September 2010

Objectives

To measure 3 intervals of time—induction of regional anesthesia to delivery (I–D), initial skin incision to delivery (S–D), and uterine incision to delivery (U–D)—in elective cesareans and to evaluate the impact of the duration of these 3 components on short‐term neonatal outcome.

Methods

We reviewed retrospective data on the duration of the components from the computerized database of the obstetrics operation room at the Sheba Medical Center, Tel Aviv, Israel, and from the medical records of term neonates.

Results

Sufficient data were available in 933 cases. The parameters associated with longer time to delivery at any stage were epidural rather than spinal anesthesia, maternal diabetes, previous cesarean delivery, antihypertensive treatment, higher birth weight (3456 g and 3285 g for U–D interval longer than 2 minutes and U–D interval up to 2 minutes, respectively; P = 0.02), and male fetus. The duration of the I–D, S–D, and U–D intervals had no significant impact on any of the measured neonatal parameters.

Conclusion

With regard to neonatal wellbeing, obstetricians have a relatively large safety margin in the time taken for inducing regional anesthesia and making the first and uterine incisions.
Prevalence of select infectious agents in inflammatory aural and nasopharyngeal polyps from client-owned cats
Authors: Klose Tyler C. , MacPhail Catriona M. , Schultheiss Patricia C. , Rosychuk Rod A. , Hawley Jennifer R. , Lappin Michael R.
Published: September 2010

Benign, inflammatory polyps may affect the nasopharynx and auditory canal of cats. It has been proposed that inflammation induced by infectious disease agents could trigger polyp formation. The objective of this pilot study was to determine the prevalence of feline herpesvirus-1 (FHV-1), feline calicivirus (FCV), Mycoplasma species, Bartonella species and Chlamydophila felis nucleic acids in polyp tissues collected from 30 clinically affected cats. Samples collected from the tympanic bulla from 12 clinically normal cats were also assayed. DNA or RNA of some of the target agents were amplified from samples from 25% of normal cats and 33% of affected cats; however, statistical associations were not detected for individual agent results or grouped results. The study documents that common oropharyngeal or blood borne agents can be detected in the tympanic bullae of normal cats. Failure to consistently amplify RNA or DNA of the select agents from polyp tissues suggests the agents studied were not directly associated with the pathogenesis of this syndrome in the cats tested. Alternately, the inflammatory response may have cleared microbial nucleic acids to undetectable levels by the time of sample collection.
Fungal rhinosinusitis caused by Scedosporium apiospermum in a cat
Authors: Leperlier Dimitri , Vallefuoco Rosario , Laloy Eve , Debeaupuits Julien , De Thibaud Pauline Fornel , Crespeau François-Lucien , Guillot Jacques
Published: September 2010

A 3-year-old neutered male Bengal cat with a history of chronic mucopurulent bilateral nasal discharge and sneezing was diagnosed with severe fungal rhinosinusitis. A diagnosis was obtained after computer tomography imaging, histopathological examination and fungal culture. The mold Scedosporium apiospermum was identified as the aetiological agent. To our knowledge, this case is the first description of a rhinitis or sinusitis caused by this agent in a cat. Aggressive surgical debridement combined with topical and systemic antifungal therapy was performed. Unfortunately, the treatment resulted only in a partial remission of signs.
The effects of fire and tephra deposition on forest vegetation in the Central Cascades, Oregon
Authors: Long Colin J. , Power Mitchell J. , Bartlein Patrick J.
Published: September 2010

High-resolution charcoal and pollen analyses were used to reconstruct a 12,000-yr-long fire and vegetation history of the Tumalo Lake watershed and to examine the short-term effects that tephra deposition have on forest composition and fire regime. The record suggests that, from 12,000 to 9200 cal yr BP, the watershed was dominated by an open Pinus forest with Artemisia as a common understory species. Fire episodes occurred on average every 115 yr. Beginning around 9200 cal yr BP, and continuing to the present, Abies became more common while Artemisia declined, suggesting the development of a closed forest structure and a decrease in the frequency of fire episodes, occurring on average every 160 yr. High-resolution pollen analyses before and after the emplacement of three distinct tephra deposits in the watershed suggest that nonarboreal species were most affected by tephra events and that recovery of the vegetation community to previous conditions took between 40 and 100 yr. Changes in forest composition were not associated with tephra depositional events or changes in fire-episode frequency, implying that the regional climate is the more important control on long-term forest composition and structure of the vegetation in the Cascade Range.