bluuebunny/crossref_metadata_2025 huggingface dataset:
Wanted: dead or alive? Isotopic analysis (δ13C and δ15N) of Pygoscelis penguin chick tissues supports opportunistic sampling
Authors: Vasil Christopher A. , Polito Michael J. , Patterson William P. , Emslie Steven D.
Published: February 2012

RATIONALE

Physiological stress and starvation have been shown to affect δ13C and δ15N isotope values and, given that animals often die from starvation, the cause of death may be an important factor to consider in stable isotope analyses of opportunistically collected samples.

METHODS

We addressed this issue by comparing tissue stable isotope values of living and deceased Adélie (Pygoscelis adeliae) and Chinstrap Penguin (P. antarctica) chicks collected from the same respective populations.

RESULTS

No significant difference was found between living and deceased penguin chick feather, down, and toenail isotope values and both groups displayed similar isotopic trends between tissue types. In addition, similar relationships were observed between both species and across several seasons. Furthermore, sub‐dermal adiposity and cause of death (starvation and/or predation) had no significant effect on the δ13C and δ15N values.

CONCLUSIONS

Our findings suggest that tissues from deceased penguins can be isotopically representative of tissues obtained from the living population, despite the cause of death, and support the use of opportunistic sampling in stable isotope analyses. Copyright © 2012 John Wiley & Sons, Ltd.
Comparison between a high‐resolution single‐stage Orbitrap and a triple quadrupole mass spectrometer for quantitative analyses of drugs
Authors: Henry Hugues , Sobhi Hamid Reza , Scheibner Olaf , Bromirski Maciej , Nimkar Subodh B. , Rochat Bertrand
Published: February 2012

The capabilities of a high‐resolution (HR), accurate mass spectrometer (Exactive‐MS) operating in full scan MS mode was investigated for the quantitative LC/MS analysis of drugs in patients' plasma samples. A mass resolution of 50 000 (FWHM) at m/z 200 and a mass extracted window of 5 ppm around the theoretical m/z of each analyte were used to construct chromatograms for quantitation. The quantitative performance of the Exactive‐MS was compared with that of a triple quadrupole mass spectrometer (TQ‐MS), TSQ Quantum Discovery or Quantum Ultra, operating in the conventional selected reaction monitoring (SRM) mode. The study consisted of 17 therapeutic drugs including 8 antifungal agents (anidulafungin, caspofungin, fluconazole, itraconazole, hydroxyitraconazole posaconazole, voriconazole and voriconazole‐N‐oxide), 4 immunosuppressants (ciclosporine, everolimus, sirolimus and tacrolimus) and 5 protein kinase inhibitors (dasatinib, imatinib, nilotinib, sorafenib and sunitinib). The quantitative results obtained with HR‐MS acquisition show comparable detection specificity, assay precision, accuracy, linearity and sensitivity to SRM acquisition. Importantly, HR‐MS offers several benefits over TQ‐MS technology: absence of SRM optimization, time saving when changing the analysis from one MS to another, more complete information of what is in the samples and easier troubleshooting. Our work demonstrates that U/HPLC coupled to Exactive HR‐MS delivers comparable results to TQ‐MS in routine quantitative drug analyses. Considering the advantages of HR‐MS, these results suggest that, in the near future, there should be a shift in how routine quantitative analyses of small molecules, particularly for therapeutic drugs, are performed. Copyright © 2012 John Wiley & Sons, Ltd.
Using stable isotope analysis to discriminate gasoline on the basis of its origin
Authors: Heo Su‐Young , Shin Woo‐Jin , Lee Sin‐Woo , Bong Yeon‐Sik , Lee Kwang‐Sik
Published: February 2012

RATIONALE

Leakage of gasoline and diesel from underground tanks has led to a severe environmental problem in many countries. Tracing the production origin of gasoline and diesel is required to enable the development of dispute resolution and appropriate remediation strategies for the oil‐contaminated sites.

METHODS

We investigated the bulk and compound‐specific isotopic compositions of gasoline produced by four oil companies in South Korea: S‐Oil, SK, GS and Hyundai. The relative abundance of several compounds in gasoline was determined by the peak height of the major ion (m/z 44).

RESULTS

The δ13CBulk and δDBulk values of gasoline produced by S‐Oil were significantly different from those of SK, GS and Hyundai. In particular, the compound‐specific isotopic value (δ13CCSIA) of methyl tert‐butyl ether (MTBE) in S‐Oil gasoline was significantly lower than that of gasoline produced by other oil companies. The abundance of several compounds in gasoline, such as n‐pentane, MTBE, n‐hexane, toluene, ethylbenzene and o‐xylene, differed widely among gasoline from different oil companies.

CONCLUSIONS

This study shows that gasoline can be forensically discriminated according to the oil company responsible for its manufacture using stable isotope analysis combined with multivariate statistical analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Differentiation of two industrial oil sands process‐affected waters by two‐dimensional gas chromatography/mass spectrometry of diamondoid acid profiles
Authors: Rowland Steven J. , West Charles E. , Scarlett Alan G. , Ho Cheuk , Jones David
Published: February 2012

RATIONALE

Processing of the oil sands of Canada has produced large amounts of process‐affected water (OSPW). Concerns have been raised over the possible environmental impacts of any leakage of OSPW from storage lagoons which contain toxicants, including organic acids. Natural weathering of oil sands deposits may also produce the toxicants, including the acids. Therefore, there is a need for differentiation of the possible natural and industrial sources of such toxicants and also for methods suitable for monitoring changes in the composition of OSPW during long‐term storage.

METHODS

Here we show in a simple preliminary study of the two samples currently available to us, by use of comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry (GCxGC/ToF‐MS), the distributions of methyl esters of individual isomeric diamondoid acids in OSPW from lagoons with different histories and from different industrial operators.

RESULTS

We show that the distributions of methyl esters of individual isomeric diamondoid acids, including methyladamantane carboxylic and ethanoic acids, identified by comparison with data for reference compounds, can be differentiated readily. The use of acids with known structures, each verified by authentic acids, known toxicities and known and/or predictable physicochemical properties, to distinguish the different sources is advantageous, since factors likely to control the fate and dispersion of the acids can then more easily be predicted. It is postulated that the differences observed in the relative amounts of some of the acids result from variable extents of bacterial transformation of the organic matter in OSPW.

CONCLUSIONS

The differences in distributions of diamondoid acids clearly vary between the two samples of OSPW and may prove very useful for monitoring the fate of different sources of OSPW both in storage and in the wider environment, once a wider collection of representative samples is available for study. Copyright © 2012 John Wiley & Sons, Ltd.
Public key encryption supporting plaintext equality test and user‐specified authorization
Authors: Tang Qiang
Published: February 2012

In this paper, we investigate a category of public key encryption schemes that supports plaintext equality test and user‐specified authorization. With this new primitive, two users, who possess their own public/private key pairs, can issue token(s) to a proxy to authorize it to perform plaintext equality test from their ciphertexts. We provide a formal formulation for this primitive and present a construction with provable security in our security model. To mitigate the risks against the semi‐trusted proxies, we enhance the proposed cryptosystem by integrating the concept of computational client puzzles. As a showcase, we construct a secure personal health record application on the basis of this primitive. Copyright © 2012 John Wiley & Sons, Ltd.
Analytical methodologies for the investigation of soil‐induced degradation of Cu‐based archaeological artefacts
Authors: Mezzi A. , de Caro T. , Riccucci C. , Parisi E. I. , Faraldi F. , Vassiliou P. , Grassini S.
Published: February 2012

Archaeological bronze artefacts are covered with corrosion products, that is, the patinas, whose nature depends on different degradation processes occurring during long‐term burial. As a consequence of the corrosion phenomenon, surfaces of archaeological metal objects are composed of a complex structure. By means of the combined use of different analytical techniques such as XPS, scanning electron microscopy combined with energy dispersive X‐ray spectroscopy, optical microscopy and X‐ray diffraction, some typical patinas grown on Roman and Punic archaeological bronze artefacts have been studied in details by selecting a suitable methodological approach to acquire micro‐chemical, morphological and structural information. The XPS measurements of Cu 2p, Cu LMM and valence band spectra of archaeological objects and reference samples such as CuCl2, CuCl, Cu2Cl(OH)3, Cu2O and CuO allowed us to identify the different copper oxidation states and crystallographic phases present in a patina. Moreover, the XPS elemental concentration depth profiles have yielded information about the stratified outermost layers and the occurrence of the migration phenomenon from bulk to surface due to selective corrosion processes. These pieces of information compared with those achieved via scanning electron microscopy combined with energy dispersive X‐ray spectroscopy, optical microscopy and X‐ray diffraction reveal the complex chemistry and morphology of the patina, highlighting also the correlation between patina and burial context. Copyright © 2012 John Wiley & Sons, Ltd.
Depth profiling analysis of damaged arginine films with Ar cluster ion beams
Authors: Matsuo J. , Ichiki K. , Yamamoto Y. , Seki T. , Aoki T.
Published: February 2012

Ar cluster ion beams provide unique opportunities for organic material analysis. SIMS with Ar cluster ion beams have been utilized for thin films of biomaterials and organic semiconductor multilayers. No degradation in SIMS spectra was found after sputtering with Ar cluster ion beams. In addition, a damage layer formed with ion irradiation of monomer Ga at a dose of 1 × 1014 ions/cm2 was removed with an Ar cluster beam without additional damage being created. The structure and depth of damage induced with monomer ions can be evaluated with Ar cluster SIMS. The measured thickness of the damaged layer is very close to the value calculated with TRIM. These results indicate that damage in organic materials introduced with energetic ions can be evaluated with this technique. Copyright © 2012 John Wiley & Sons, Ltd.
Fabrication and characterisation of conducting composite films based on conducting polymers and functionalised carbon nanotubes
Authors: Branzoi Florina , Branzoi Viorel , Musina Ancuta
Published: February 2012

Electropolymerisation and characterisation of polyaniline film doped with functionalised single‐wall carbon nanotubes and different dopants were studied. These nanoporous composite films were grown electrochemically from aqueous solutions such that constituents were deposited simultaneously onto substrate electrode. The synthetic, morphological and electrical properties of obtained nanocomposite films were compared. SEM revealed that the composite films consisted of nanoporous networks of single‐wall carbon nanotubes coated with polymeric film. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that these composite films had similar electrochemical response rates to pure polymeric films but a lower resistance and much improved mechanical integrity. The negatively charged functionalised carbon nanotubes served as anionic dopant during the electropolymerisation to synthesize polymer/functionalised carbon nanotube composite films. The specific electrochemical capacitance of the composite films is a significantly greater value than that for pure polymer films prepared similarly. Using these composite films, the modified electrodes with improved properties were obtained. Copyright © 2012 John Wiley & Sons, Ltd.
Structure and chemical composition of mixed benzylguanine‐ and methoxy‐terminated self‐assembled monolayers for immobilization of biomolecules
Authors: Bruns M. , Barth C. , Brüner P. , Engin S. , Grehl T. , Howell C. , Koelsch P. , Mack P. , Nagel P. , Trouillet V. , Wedlich D. , White R. G.
Published: February 2012

Covalent immobilization of biomolecules has become a subject of great interest in recent years because of the expected diversity of applications, for example, biosensors in diagnosis, lab‐on‐chip technology, and modern cell culture focused on cell adhesion, migration, and differentiation. Our approach is to produce self‐assembled monolayers (SAMs) on gold surfaces based on mixtures of a benzylguanine‐terminated thiol and a thiol, carrying ethylene glycol groups. The benzylguanine head group of such SAMs acts as a substrate for the SNAP‐tag system allowing for covalent attachment of any protein of interest fused to this tag. For this purpose, it is essential to determine the orientation and chemical composition of these layers. In this study, we use the strength of combining complementary surface analytical methods to achieve a comprehensive characterization. The chemical composition and the covalent binding of the thiols were proved by X‐ray photoelectron spectroscopy (XPS). The orientation of the SAMs together with thickness information was achieved by nondestructive depth profiles reconstructed from parallel angle‐resolved XPS data and energy‐resolved photoelectron emission spectroscopy (PES). High‐sensitivity low‐energy ion scattering and sum‐frequency‐generation spectroscopy corroborate the XPS/PES results. Copyright © 2012 John Wiley & Sons, Ltd.
Study of interfaces between phase‐change material Ge2Sb2Te5 and prevalent complementary metal‐oxide semiconductor materials by XPS
Authors: Pan Jisheng , Fang Lina Wei‐Wei , Zhang Zheng , Yeo Yee‐Chia
Published: February 2012

The energy band alignment between Ge2Sb2Te5 (GST) and common microelectronic materials such as dielectrics and metals was investigated using XPS. Energy band lineups of GST with various complementary metal‐oxide semiconductor dielectrics, that is, SiO2, HfO2, Ta2O5 and Si3N4, were thus determined, which can be used as for phase change memory device engineering and integration with complementary metal‐oxide semiconductor technology. Hole barrier height at metal/GST interface is reduced slightly by increasing the work function of the metal. Doping GST with nitrogen leads to an increase in hole barrier height at the interface between metals and nitrogen‐doped GST. Significant pinning of metal Fermi level towards the valence band energy of undoped and nitrogen‐doped GST was discovered. This leads to low hole barrier height and good ohmic contact formed between metals and GST. The hole barrier height between crystalline GST and various metals appears to increase as compared with the amorphous state. Copyright © 2012 John Wiley & Sons, Ltd.
Classification accuracy and cut point selection
Authors: Liu Xinhua
Published: February 2012

In biomedical research and practice, quantitative tests or biomarkers are often used for diagnostic or screening purposes, with a cut point established on the quantitative measurement to aid binary classification. This paper introduces an alternative to the traditional methods based on the Youden index and the closest‐to‐(0, 1) criterion for threshold selection. A concordance probability evaluating the classification accuracy of a dichotomized measure is defined as an objective function of the possible cut point. A nonparametric approach is used to search for the optimal cut point maximizing the objective function. The procedure is shown to perform well in a simulation study. Using data from a real‐world study of arsenic‐induced skin lesions, we apply the method to a measure of blood arsenic levels, selecting a cut point to be used as a warning threshold. Copyright © 2012 John Wiley & Sons, Ltd.
Conventional and advanced bending strength analysis of common and castellated, homogeneous and hybrid I‐beams
Authors: Chróścielewski Jacek , Cywiński Zbigniew , Sitarski Arkadiusz
Published: February 2012

An appropriate investigation has been performed in order to estimate the bending strength safety of steel I‐beams typical in traditional and up‐to‐date computational analyses. The bending strengths of the conventional analysis have been set in general form for the beam parameters of the span/depth ratios usually observed. Mutual strength relationships between common and castellated, homogeneous and hybrid I‐beams, reflect the anticipated regularities. Use of the advanced analysis, founded on the non‐linear FEM approach, required the solution of adequate practical examples. In view of the research class, certain completion of the typical non‐linear procedure was needed.

Konventionelle und verschärfte Berechnung der Biegefestigkeit normaler und wabenförmiger, homogener und hybrider I‐Träger. Um die Biegefestigkeit von stählernen I‐Trägern abzuschätzen, typischer Bestandteil traditioneller und moderner Berechnungsverfahren, wurde eine entsprechende Untersuchung unternommen. Für die üblichen Bauteilparameter der Spannweite/Höhe‐Verhältnisse wurden die Biegefestigkeiten der konventionellen Berechnung in der allgemeinen Form festgesetzt. Die ermittelten Traglastverhältnisse zwischen den normalen und wabenförmigen, homogenen und hybriden I‐Trägern gaben die erwarteten Verhältnisse wieder. Die Anwendung der verschärften Berechnungsmethode, gestützt auf dem nichtlinearen Vorgehen der FEM, bedurfte der Lösung entsprechender praktischer Beispiele. Angesichts der Untersuchungsklasse war eine Ergänzung des typischen nichtlinearen Verfahrens nötig.
Ersatzneubau der Autobahnbrücke über den Havelkanal bei Brieselang
Authors: Degenhardt‐Herberger Kay , Reinke Klaus‐Dieter
Published: February 2012

Die Autobahn A10 wird im westlichen Teil des Berliner Rings in der Nähe der Ortschaft Brieselang über den Havelkanal geführt. Ein Konstruktionsfehler in der Lagerung erforderte den Ersatz des bestehenden Bauwerkes. Für den Ersatzneubau wurde insbesondere unter Berücksichtigung wirtschaftlicher und gestalterischer Aspekte eine Ausführung in Form einer Netzwerkbogenbrücke mit Radialnetz als beste Lösung für den Brückenschlag gefunden. Der Bericht befasst sich mit Aspekten des Bauwerksentwurfes, der Ausschreibung und Vergabe sowie der Bauausführung des im November 2011 fertiggestellten Brückenbauwerkes.

Reconstruction of the motorway bridge over the Havelkanal near Brieselang, Germany. The motorway A10 is routed over the Havelkanal in the western part of the Berliner Ring, a perimeter road, close to the small town of Brieselang. Due to a constructional fault of the bearings the replacement of the old bridge became necessary. Considering all economic and design aspects, a network arch bridge with radial net was chosen as most suitable solution. The paper discusses aspects of conceptual design, tendering and contracting as well as the construction work of the new bridge completed in November 2011.
Meaning of Political Controversy in the Classroom: A Dialogue Across The Podium
Authors: Belgrave Linda Liska , Celaya Adrienne , Gurses Seyda Aylin , Boutwell Angelica , Fernandez Alexandra
Published: February 2012

The abstract value of academic freedom is enjoyed (or not) in concrete settings, as interactional and emergent experiences. We examine classroom political controversy in our experiences, understandings, and values, using grounded theory methods and collective autoethnography by a team of five teachers and students. Our data were generated through electronic and face‐to‐face dialogues. Our analysis, guided by a symbolic interactionist and constructionist framework, yields a picture of Controversy in Action, whereby we navigate Barriers to Open Discussion and Costs of Controversy. Results highlight insights into taken‐for‐granted meanings unexamined in day‐to‐day classroom interaction. We attend to the relevance of the local context in which our classrooms are embedded and the interactional, meaning creating work that goes on in those classrooms, as we negotiate controversy.
Subcultural Identity Work in Social Movements: Barriers to Collective Identity Changes and Overcoming Them
Authors: Gongaware Timothy B.
Published: February 2012

Over time, social movements must contend with a vast array of forces that can lead to changes in the movement's collective identity. As such changes may impact the alignment of movements and their membership, this study explores how changes are perceived by members and how they are interactively addressed. Drawing on ethnographic data gathered from two Native American social movement organizations, this study specifically asks why some changes suggested by movement members might be pursued and others are not. While movement members felt that there were a number of barriers to changes in their movements, the study revealed that it was the resonance of collective memories – presented during interactions as narrative commemorations – that encouraged the pursuit of suggested changes or the maintenance of a status quo.
Memorial Essay: Harold Garfinkel (1917–2011): A Sociologist for the Ages
Authors: Maynard Douglas W.
Published: February 2012

Harold Garfinkel, the founder of Ethnomethodology, died at home on April 21, 2011 of congestive heart failure. A major sociologist of the twentieth century, his contribution to many fields will undoubtedly continue to be felt for years to come. In this essay, I will discuss the origins of the term “ethnomethodology,” briefly explore ethnomethodology's relationship with symbolic interactionism, provide a biographical overview of Garfinkel's oeuvre, list some ways in which the work has had a massive influence, and end with a short discussion of Garfinkel's legacy.
Combined effect of hindered amine light stabilizer and ultraviolet absorbers on photodegradation of poly(vinyl chloride)
Authors: Chai Ruidan , Chen Shuangjun , Zhang Jun
Published: February 2012

The combined effect of a basic hindered amine light stabilizer (HALS) and ultraviolet absorbers (UVAs) on casted poly(vinyl chloride) (PVC) films, during photodegradation, was studied by color change, ultraviolet‐visible (UV–vis) spectroscopy, Fourier‐transform infrared (FTIR) spectroscopy, and viscosity‐average molecular weight. It was found that the basic amine groups in the HALS (T770) could promote the dehydrochlorination, thereby accelerating the photooxidation of PVC films. Meanwhile, T770 could scavenge the radicals formed and restrain the aging of PVC to some extent. The above‐mentioned aspects were competing factors: the former played a dominant role during the first 100 h, while the latter counteracted the former effect to some extent between 100 and 300 h. A benzotriazole derivative (UV326) absorbs more UV radiation in the UV‐A region (320–400 nm), which mainly causes the photodegradation of PVC samples, than a benzophenone derivative (UV531). Thus, UV326 is a more efficient UV absorber than UV531 in prohibiting the photooxidation and chain scission of PVC films. The combination of T770 and UV326 effectively protected PVC films from dehydrochlorination and photooxidation. The combination of T770 and UV531 accelerated the dehydrochlorination and discoloration of PVC films. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers
Effects of polymerization catalyst technology on the melt processing stability of polyethylenes. part 2. single stabilizer performance
Authors: del Teso Sánchez Karmele , Allen Norman S. , Liauw Christopher M. , Edge Michelle , Johnson Brian , Catalina Fernando , Corrales Teresa
Published: February 2012

The effects of a range of thermal and light stabilizers on the melt stability (investigated via multiple pass extrusion) and color stability of three different polyethylenes (PEs) were examined. The PEs varied in terms of the catalyst system used to synthesize the polymers and included an HDPE produced by using a chromium‐based Phillips catalyst and two LLDPEs produced via chromium‐based metallocene and titanium‐based Ziegler‐Natta catalysts. The additive types included a range of phenolics of different functionality, phosphites, hindered piperidines, an hydroxylamine, and Vitamin E. The results obtained for the three PEs confirmed that primary antioxidants (AOs) such as highly hindered and less, hindered phenols or hydroxylamines promoted good melt stability but in some cases tended toward yellowing. The secondary AOs such as the phosphites or thioethers behaved in the opposite way; color suppression was good, but melt stabilization was poor. It was also shown that for different types of phenols (all with similar molar activity), reducing steric hindrance to the phenolic OH enhanced the tendency to form chromophoric groups and hence color led to better efficiency than high hindrance. Those phenol with higher molar activity (mol OH/kg AO) showed the best processing performance. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers
Effects of polyethylene‐grafted maleic anhydride as a compatibilizer on the morphology and tensile properties of (thermoplastic tapioca starch)/ (high‐density polyethylene)/(natural rubber) blends
Authors: Kahar A.W.M. , Ismail H. , Othman N.
Published: February 2012

Effects of polyethylene‐grafted maleic anhydride as a compatibilizer on the tensile properties of (high‐density polyethylene)/(natural rubber)/(thermoplastic tapioca starch) (HDPE/NR/TPS) blends were investigated. The ratio of HDPE/NR was fixed at 70/30, and these materials were blended with TPS in concentrations varying from 5 to 30% by using a Haake Rheomix 600 mixer. Two series of HDPE/NR/TPS blends were prepared, i.e., with and without compatibilizer. Morphology and tensile properties of the HDPE/NR/TPS blends were evaluated as a function of TPS loading. The tensile strength and elongation at break decreased with the increase of TPS content. However, an improvement in the tensile strength was obtained for compatibilized blends as compared to uncompatibilized blends. The degrees of TPS adhesion and dispersion in HDPE/NR blends were revealed by scanning electron microscopy (SEM). Results showed that a smaller‐sized dispersed phase was achieved for compatibilized blends as compared to that for their uncompatibilized counterparts. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers
Rheometric study of the gelation and fusion processes of poly(vinyl chloride‐co‐vinyl acetate) plastisols with different commercial plasticizers
Authors: Zoller Agnes , Marcilla Antonio
Published: February 2012

Evolution of the complex viscosity of pastes of PVC‐VA (vinyl chloride‐vinyl acetate copolymer) plasticized with different commercial plasticizers has been studied. Knowledge of the rheological behavior of the formulations allows for better understanding of the gelation and fusion processes. Twenty commercial plasticizers of different types and with different functional groups have been studied and are grouped into five families: phthalate esters with linear chains, phthalate esters with branched chains, adipates (normal and polymeric), citrates, and rest of the plasticizers (carboxylates, alkylsulfonates, and pentaerythritol ester derivatives). Interesting relationships among the observed rheologies and the nature and molecular weight of the plasticizer have been observed. The evolution of the complex viscosity with temperature—at the temperatures where the blowing agents normally used in PVC plastisol foaming processes generate the main amount of gas—has been newly discussed with regard to the chemical structure and molecular weight of all of the plasticizers used. It was found that several different dynamic processes must be synchronized in order to understand the relationships among the chemical structure, plasticization, plasticizer compatibility, rheological properties, and foaming process of such materials. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers
Thermal degradation and flame retardance of epoxy resins containing a microencapsulated flame retardant
Authors: Gao Ming , Wu Weihong , Wu Fachao
Published: February 2012

Two steps were used in the synthesis of a microencapsulated intumescent flame retardant (MIFR). First bis (1‐oxo‐2,6,7‐trioxa‐l‐phosphabicyclo[2.2.2]octane‐4‐methylol) phosphate melaminium salt (Melabis) was synthesized. Then the Melabis was encapsulated with melamine resin to obtain the MIFR. Its structure was characterized by XPS, SEM, and elemental analysis, and the factors affecting microencapsulation were identified and discussed. Epoxy resins (EP) were modified with the MIFR to prepare flame‐retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI) tests. The microcapsules (20% by weight) were added to EP in order to achieve an LOI of 29.5% and a UL 94 rating of V‐0. The thermal properties of epoxy resins containing the MIFR were investigated by thermogravimetry (TG) and differential thermogravimetry (DTG). The FR decreased by weight loss, Rmax (the maximum weight loss rate), and the thermal stability of EP while promoting the formation of an effective charring layer. The char structures were studied by SEM. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers
Clinicopathological Profile, Airway Management, and Outcome in Huge Multinodular Goiters: An Institutional Experience from an Endemic Goiter Region
Authors: Agarwal Amit , Agarwal Sudhi , Tewari Prabhat , Gupta Sushil , Chand Gyan , Mishra Anjali , Agarwal Gaurav , Verma A. K. , Mishra S. K.
Published: February 2012

Background

Huge goiters are common in iodine‐deficient endemic regions. They are of concern to the surgeons because of the anticipated risk of difficult dissection and increased chances of surgical complications. Similarly, they are of concern to the anesthesiologists because of anticipated intubation‐related difficulties and post‐thyroidectomy tracheomalacia. In the present study we aimed to present our experience of managing goiters based on their gross weight, highlighting their clinicopathological profile, perioperative airway‐related difficulties, and management of surgical morbidity.

Methods

Retrospective analysis of patients who underwent total thyroidectomy in the primary setting at our institute from 1995 to 2009 was carried out based on the gross gland weight. The patients were thus grouped into group A: ≤200 g; group B: 201 to ≤400 g; group C: 401 to ≤600 g; group D: >600 g.

Results

Group A (660 cases); group B (108 cases); group C (36 cases); and group D (9 cases) were included. As the goiter size increased, the mean duration of goiter, compressive symptoms, retrosternal extension (RSE), airway deformity, intubation difficulty, and tracheomalacia increased. The rate of tracheostomy, sternotomy, hemorrhage, visceral injury, and hospital stay was high with huge goiters. These features were more marked in malignant goiters compared to benign goiters. However, the postoperative complications were comparable in both of those groups.

Conclusions

Long‐standing huge goiters are common in iodine‐deficient endemic areas. The majority of patients have symptomatic or clinicoradiological evidence of airway involvement. The incidence of RSE, airway deformity, intubation difficulty, and tracheomalacia is high with huge goiters. The surgery is technically demanding with greater associated chances of injury to native structures. Malignancy influences the presentation and outcome in smaller goiters. In centers with experienced endocrine surgeons and dedicated anesthetists, huge goiters can be successfully managed with minimal short‐term and long‐term morbidity.
Improving test properties for neonatal cystic fibrosis screening in the Netherlands before the nationwide start by May 1st 2011
Authors: Cornel Martina C. , Gille Johan J. P. , Loeber J. Gerard , Langen Annette M. M. Vernooij‐van , Dankert‐Roelse Jeannette , Bolhuis Piet A.
Published: February 2012

When new technical possibilities arise in health care, often attunement is needed between different actors from the perspectives of research, health care providers, patients, ethics and policy. For cystic fibrosis (CF) such a process of attunement in the Netherlands started in a committee of the Health Council on neonatal screening in 2005. In the balancing of pros and cons according to Wilson and Jungner criteria, the advantages for the CF patient were considered clear, even though CF remains a severe health problem with treatment. Nevertheless, screening was not started then, mainly since the specificity of the tests available at that time was considered too low. Many healthy infants would have been referred for sweat testing and much uncertainty would arise in their parents. Also the limited sensitivity for immigrants and the detection of less severe phenotypes and carriers were considered problematic. The Health Council recommended a pilot screening project which was subsequently performed in some provinces, leading to a 4‐step protocol: IRT, PAP, screening for a CFTR mutation panel, and sequencing of the CFTR gene. This would lead to the identification of 23 cases of classical CF, two infants with less severe forms and 12 carriers per year in the Netherlands. Thus many CF patients can be diagnosed early, while limiting the number of referrals, the number of infants with less severe forms diagnosed and the number of carriers identified. Technical solutions were found to limit the ethical problems. A nationwide program using this four step protocol started by 1 May 2011.
Genetic Counseling as a Tool for Type 2 Diabetes Prevention: A Genetic Counseling Framework for Common Polygenetic Disorders
Authors: Waxler Jessica L. , O'Brien Kelsey E. , Delahanty Linda M. , Meigs James B. , Florez Jose C. , Park Elyse R. , Pober Barbara R. , Grant Richard W.
Published: February 2012

Advances in genetic epidemiology have increased understanding of common, polygenic preventable diseases such as type 2 diabetes. As genetic risk testing based on this knowledge moves into clinical practice, we propose that genetic counselors will need to expand their roles and adapt traditional counseling techniques for this new patient set. In this paper, we present a genetic counseling intervention developed for a clinical trial [Genetic Counseling/Lifestyle Change for Diabetes Prevention, ClinicalTrials.gov identifier: NCT01034319] designed to motivate behavioral changes for diabetes prevention. Seventy‐two phenotypically high‐risk participants received counseling that included their diabetes genetic risk score, general education about diabetes risk factors, and encouragement to participate in a diabetes prevention program. Using two validated genetic counseling scales, participants reported favorable perceived control and satisfaction with the counseling session. Our intervention represents one model for applying traditional genetic counseling principles to risk testing for polygenetic, preventable diseases, such as type 2 diabetes.
Adaptive diversity of innate immune receptor family short pentraxins in Murinae
Authors: Li Yan , Robins Judith H. , Ye Jianping , Huang Zhiyong , Wen Qiang , Zhang Guojie
Published: February 2012

The short pentraxins C‐reactive protein (CRP) and serum amyloid P component (SAP) constitute a group of innate immune receptors that trigger immune activation by detecting molecules of the microbial cell wall. Here, we examined the evolution of short pentraxins in Murinae lineages. By molecular evolutionary analysis, CRP and SAP have been experiencing rapid diversification, driven by adaptive selection. Further, our protein modeling demonstrates that adaptively selected amino acids lie in the ligand‐binding region and contact region between subunits. Our findings suggest that rapid diversification of these regions could contribute to the determinants of recognizing specificity and the interaction between subunits.
Sinking, merging and stationary plumes in a coupled chemotaxis-fluid model: a high-resolution numerical approach
Authors: Chertock A. , Fellner K. , Kurganov A. , Lorz A. , Markowich P. A.
Published: February 2012

Aquatic bacteria like Bacillus subtilis are heavier than water yet they are able to swim up an oxygen gradient and concentrate in a layer below the water surface, which will undergo Rayleigh–Taylor-type instabilities for sufficiently high concentrations. In the literature, a simplified chemotaxis–fluid system has been proposed as a model for bio-convection in modestly diluted cell suspensions. It couples a convective chemotaxis system for the oxygen-consuming and oxytactic bacteria with the incompressible Navier–Stokes equations subject to a gravitational force proportional to the relative surplus of the cell density compared to the water density. In this paper, we derive a high-resolution vorticity-based hybrid finite-volume finite-difference scheme, which allows us to investigate the nonlinear dynamics of a two-dimensional chemotaxis–fluid system with boundary conditions matching an experiment of Hillesdon et al. (Bull. Math. Biol., vol. 57, 1995, pp. 299–344). We present selected numerical examples, which illustrate (i) the formation of sinking plumes, (ii) the possible merging of neighbouring plumes and (iii) the convergence towards numerically stable stationary plumes. The examples with stable stationary plumes show how the surface-directed oxytaxis continuously feeds cells into a high-concentration layer near the surface, from where the fluid flow (recurring upwards in the space between the plumes) transports the cells into the plumes, where then gravity makes the cells sink and constitutes the driving force in maintaining the fluid convection and, thus, in shaping the plumes into (numerically) stable stationary states. Our numerical method is fully capable of solving the coupled chemotaxis–fluid system and enabling a full exploration of its dynamics, which cannot be done in a linearised framework.
Dissipation element analysis in turbulent channel flow
Authors: Aldudak Fettah , Oberlack Martin
Published: February 2012

In order to analyse the geometric structure of turbulent flow patterns and their statistics for various scalar fields we adopt the dissipation element (DE) approach and apply it to turbulent channel flow by employing direct numerical simulations (DNS) of the Navier–Stokes equations. Gradient trajectories starting from any point in a scalar field $\phi (x, y, z, t)$ in the directions of ascending and descending scalar gradients will always reach an extremum, i.e. a minimum or a maximum point, where $\boldsymbol{\nabla} \phi = 0$. The set of all points and trajectories belonging to the same pair of extremal points defines a dissipation element. Extending previous DE approaches, which were only applied to homogeneous turbulence, we here focus on exploring the influence of solid walls on the dissipation element distribution. Employing group-theoretical methods and known symmetries of Navier–Stokes equations, we observe for the core region of the flow, i.e. the region beyond the buffer layer, that the probability distribution function (p.d.f.) of the DE length exhibits an invariant functional form, in other words, self-similar behaviour with respect to the wall distance. This is further augmented by the scaling behaviour of the mean DE length scale which shows a linear scaling with the wall distance. The known proportionality of the mean DE length and the Taylor length scale is also revisited. Utilizing a geometric analogy we give the number of DE elements as a function of the wall distance. Further, it is observed that the DE p.d.f. is rather insensitive, i.e. invariant with respect both to the Reynolds number and the actual scalar $\phi $ which has been employed for the analysis. In fact, a very remarkable degree of isotropy is observed for the DE p.d.f. in regions of high shear. This is in stark contrast to classical Kolmogorov scaling laws which usually exhibit a strong dependence on quantities such as shear, anisotropy and Reynolds number. In addition, Kolmogorov’s scaling behaviour is in many cases only visible for very large Reynolds numbers. This is rather different in the present DE approach which applies also for low Reynolds numbers. Moreover, we show that the DE p.d.f. agrees very well with the log-normal distribution and derive a log-normal p.d.f. model taking into account the wall-normal dependence. Finally, the conditional mean scalar differences of the turbulent kinetic energy at the extremal points of DE are examined. We present a power law with scaling exponent of $2/ 3$ known from Kolmogorov’s hypothesis for the centre of the channel and a logarithmic law near the wall.
Multidimensional expanding maps with singularities: a pedestrian approach
Authors: LIVERANI CARLANGELO
Published: February 2012

I provide a proof of the existence of absolutely continuous invariant measures (and study their statistical properties) for multidimensional piecewise expanding systems with not necessarily bounded derivative or distortion. The proof uses basic properties of multidimensional BV functions (the space of functions of bounded variations).
Examples of amalgamated free products and coupling rigidity
Authors: KIDA YOSHIKATA
Published: February 2012

We present amalgamated free products satisfying coupling rigidity with respect to the automorphism group of the associated Bass–Serre tree. As an application, we obtain orbit equivalence rigidity for amalgamated free products of mapping class groups.
On quasi-interpretations, blind abstractions and implicit complexity
Authors: BAILLOT PATRICK , DAL LAGO UGO , MOYEN JEAN-YVES
Published: February 2012

Quasi-interpretations are a technique for guaranteeing complexity bounds on first-order functional programs: in particular, with termination orderings, they give a sufficient condition for a program to be executable in polynomial time (Marion and Moyen 2000), which we call the P-criterion here. We study properties of the programs satisfying the P-criterion in order to improve the understanding of its intensional expressive power. Given a program, its blind abstraction is the non-deterministic program obtained by replacing all constructors with the same arity by a single one. A program is blindly polytime if its blind abstraction terminates in polynomial time. We show that all programs satisfying a variant of the P-criterion are in fact blindly polytime. Then we give two extensions of the P-criterion: one relaxing the termination ordering condition and the other (the bounded-value property) giving a necessary and sufficient condition for a program to be polynomial time executable, with memoisation.
Constraints on Cenozoic regional drainage evolution of SW China from the provenance of the Jianchuan Basin
Authors: Yan Yi , Carter Andrew , Huang Chi‐Yue , Chan Lung‐Sang , Hu Xiao‐Qiong , Lan Qing
Published: February 2012

Detrital zircon U‐Pb geochronology was applied to Cenozoic fluvial sedimentary rocks from the Jianchuan Basin, Yunnan Province, China to constrain the provenance and the nature of paleo‐drainage. Local geology testifies to a large river flowing through the Jianchuan Basin during the Paleogene and this previously has been linked to a paleo drainage system that connected the Qiangtang and Lhasa blocks to the South China Sea. The detrital zircon results from this study do not fit with this model and instead show provenance consistent with a river draining a watershed within the Songpan‐Garze Complex, most likely from the northeast. From the late Oligocene and thereafter zircon provenance records greater contributions from erosion of local sources that surround the basin including the South China Block and Yidun Arc rocks that suggest loss of the northern sources. The timing for these changes overlap with regional deformation related to strike‐slip faulting or displacement by shear strain rather than the later uplift associated with an expanding margin of the Tibetan Plateau.
Alteration at the ultramafic‐hosted Logatchev hydrothermal field: Constraints from trace element and Sr‐O isotope data
Authors: Augustin N. , Paulick H. , Lackschewitz K. S. , Eisenhauer A. , Garbe‐Schönberg D. , Kuhn T. , Botz R. , Schmidt M.
Published: February 2012

Serpentinized peridotite and gabbronorite represent the host rocks to the active, ultramafic‐hosted Logatchev hydrothermal field at the Mid‐Atlantic Ridge. We use trace element,δ18O and87Sr/86Sr data from bulk rock samples and mineral separates in order to constrain the controls on the geochemical budget within the Logatchev hydrothermal system. The trace element data of serpentinized peridotite show strong compositional variations indicating a range of processes. Some peridotites experienced geochemical modifications associated with melt‐rock interaction processes prior to serpentinization, which resulted in positive correlations of increasing high field strength element (HFSE) concentrations and light rare earth element (LREE) contents. Other serpentinites and lizardite mineral separates are enriched in LREE, lacking a correlation with HFSE due to interaction with high‐temperature, black‐smoker type fluids. The enrichment of serpentinites and lizardite separates in trace elements, as well as locally developed negative Ce‐anomalies, indicate that interaction with low‐T ambient seawater is another important process in the Logatchev hydrothermal system. Hence, mixing of high‐T hydrothermal fluids during serpentinization and/or re‐equilibration of O‐isotope signatures during subsequent low‐T alteration is required to explain the trace element andδ18O temperature constraints. Highly radiogenic87Sr/86Sr signatures of serpentinite and lizardite separates provide additional evidence for interaction with seawater‐derived fluids. Sparse talc alteration at the Logatchev site are most likely caused by Si‐metasomatism of serpentinite associated with the emplacement of shallow gabbro intrusion(s) generating localized hydrothermal circulation. In summary the geochemistry of serpentinites from the Logatchev site document subsurface processes and the evolution of a seafloor ultramafic hydrothermal system.
A method for unmixing magnetic hysteresis loops
Authors: Heslop David , Roberts Andrew P.
Published: February 2012

Hysteresis loops provide essential information concerning both induced and remanent magnetizations and are an important tool for characterizing magnetic mineral assemblages. Although the hysteresis behavior of mixed natural magnetic assemblages has been a focal point of much recent work, little progress has been made in unmixing of hysteresis loops into characteristic components. Unmixing strategies can act as cornerstones for interpretation of rock magnetic data and have become popular for characterizing isothermal remanent magnetization acquisition curves. Unmixing of hysteresis loops is, however, a challenging task because the individual component loops in the mixture must meet stringent shape constraints. We present a new technique for decomposing an ensemble of hysteresis loops into a small number of end‐members based on linear mixing theory. The end‐members are not based on type curves but instead are derived directly from the hysteresis data. Particular attention is paid to the form of the end‐members, ensuring they meet the shape constraints expected for hysteresis loops of natural magnetic mineral assemblages. Marine sediments from the Southern Ocean and lake sediments from Butte Valley, northern California, provide case studies on which the proposed unmixing method is tested.