bluuebunny/crossref_metadata_2025 huggingface dataset:
Accumulation of autofluorescent storage material in brain is accelerated by ischemia in chloride channel 3 gene‐deficient mice
Authors: Ohtaki Hirokazu , Ohara Kenji , Song Dandan , Miyamoto Kazuyuki , Tsumuraya Tomomi , Yofu Sachiko , Dohi Kenji , Tanabe Shigeru , Sasaki Sei , Uchida Shinichi , Matsunaga Masaji , Shioda Seiji
Published: July 2012

Autofluorescent storage material (ASM) is an aging pigment that accumulates during the normal course of senescence. Although the role of ASM has yet to be fully elucidated, ASM has been implicated in age‐related neurodegeneration. In this study, we determined the level of ASM in chloride channel 3 (ClC‐3) gene‐deficient (KO) mice both in response to aging and following mild global ischemia. To understand the mechanism of action of the ASM, mice subjected to ischemia were treated with the cyclooxygenase (COX) inhibitor indomethacin or with the noncompetitive glutamate receptor antagonist MK‐801. ClC‐3 KO mice displayed age‐related neurodegeneration of the neocortex as well as the hippocampus. The cortical layers in particular granular layers became thinner with aging. ASM accumulated in the brains of ClC‐3 KO mice was increased seven‐ to 50‐fold over that observed in the corresponding regions of their wild‐type littermates. Young wild‐type mice survived longer than age‐matched ClC‐3 KO mice after permanent global ischemia. However, in the case of older animals, the survival curves were similar. The ASM also increased four‐ to fivefold 10 days after mild global ischemia, an effect that was suppressed by treatment with indomethacin and MK‐801. These results suggest that temporary ischemia might trigger a process similar to aging in the brain, mimicking the effect of age‐related neurodegenerative diseases. © 2012 Wiley Periodicals, Inc.
Characterization of cellular protective effects of ATP13A2/PARK9 expression and alterations resulting from pathogenic mutants
Authors: Covy Jason P. , Waxman Elisa A. , Giasson Benoit I.
Published: July 2012

Mutations in ATP13A2, which encodes a lysosomal P‐type ATPase of unknown function, cause an autosomal recessive parkinsonian syndrome. With mammalian cells, we show that ATP13A2 expression protects against manganese and nickel toxicity, in addition to proteasomal, mitochondrial, and oxidative stress. Consistent with a recessive mode of inheritance of gene defects, disease‐causing mutations F182L and G504R are prone to misfolding and do not protect against manganese and nickel toxicity because they are unstable as a result of degradation via the endoplasmic reticulum‐associated degradation (ERAD)‐proteasome system. The protective effects of ATP13A2 expression are not due to inhibition of apoptotic pathways or a reduction in typical stress pathways, insofar as these pathways are still activated in challenged ATP13A2‐expressing cells; however, these cells display a dramatic reduction in the accumulation of oxidized and damaged proteins. These data indicate that, contrary to a previous suggestion, ATP13A2 is unlikely to convey cellular resilience simply by acting as a lysosomal manganese transporter. Consistent with the recent identification of an ATP13A2 recessive mutation in Tibetan terriers that develop neurodegeneration with neuronal ceroid lipofucinoses, our data suggest that ATP13A2 may function to import a cofactor required for the function of a lysosome enzyme(s). © 2012 Wiley Periodicals, Inc.
Surface cross‐linked UHMWPE can enable the use of larger femoral heads in total joints
Authors: Oral Ebru , Neils Andrew L. , Lyons Chelsea , Fung Mitchell , Doshi Brinda , Muratoglu Orhun K.
Published: July 2012

Limiting cross‐linking to the articular surfaces of ultrahigh molecular weight polyethylene (UHMWPE) to increase wear resistance while preventing detrimental effects of cross‐linking on mechanical strength has been a desirable goal. A surface cross‐linked UHMWPE can be achieved by blending UHMWPE with a free radical scavenger, such as vitamin E, consolidating the blend into an implant shape, extracting the vitamin E from the surface, and radiation cross‐linking the surface extracted blend. This process results in high cross‐link density in the vitamin E‐depleted surface region because vitamin E hinders cross‐linking during irradiation. In this study, we described the properties of successful extraction media and the manipulation of the wear and mechanical properties of extracted, irradiated blends. We showed that these formulations could have similar wear and significantly improved mechanical properties compared to currently available highly cross‐linked UHMWPEs. We believe that these materials can enable thinner implant forms and more anatomical designs in joint arthroplasty and may provide a feasible alternative to metal‐on‐metal implants. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:59–66, 2012
Eccentric training improves tendon biomechanical properties: A rat model
Authors: Kaux Jean‐François , Drion Pierre , Libertiaux Vincent , Colige Alain , Hoffmann Audrey , Nusgens Betty , Besançon Benoît , Forthomme Bénédicte , Le Goff Caroline , Franzen Rachel , Defraigne Jean‐Olivier , Cescotto Serge , Rickert Markus , Crielaard Jean‐Michel , Croisier Jean‐Louis
Published: July 2012

The treatment of choice for tendinopathies is eccentric reeducation. Although the clinical results appear favorable, the biomechanical changes to the tissue are not yet clear. Even if the mechanotransduction theory is commonly accepted, the physiology of tendons is not clearly understood. We aimed to better define the biomechanical and histological changes that affect healthy tendon after eccentric and concentric training. This study compared the effects of two methods of training (eccentric [E] training and concentric [C] training) with untrained (U) rats. The animals were trained over a period of 5 weeks. The tricipital, patellar, and Achilles tendons were removed, measured and a tensile test until failure was performed. A histological analysis (hematoxylin and eosin and Masson's trichrome stains) was also realized. There was a significant increase in the rupture force of the patellar and tricipital tendons between the U and E groups. The tricipital tendons in the control group presented a significantly smaller cross‐sectional area than the E‐ and C‐trained groups, but none was constated between E and C groups. No significant difference was observed for the mechanical stress between the three groups for all three tendons. Histological studies demonstrated the development of a greater number of blood vessels and a larger quantity of collagen in the E group. The mechanical properties of tendons in rats improve after specific training, especially following eccentric training. Our results partly explained how mechanical loading, especially in eccentric mode, could improve the healing of tendon. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:119–124, 2012
Sequence Position and Side Chain Length Dependence of Charge Pair Interactions in Collagen Triple Helices
Authors: Wei Fang , Fallas Jorge A. , Hartgerink Jeffrey D.
Published: July 2012

In this study, we examine eight ABC heterotrimers whose self‐assembly is directed through electrostatic interactions. Oppositely charged pairs of amino acids, with varying side chain length, were assessed for their ability to stabilize a triple helix. Aspartate‐lysine was found to result in the most thermally stable helix followed by lysine‐glutamate, ornithine‐aspartate, and finally ornithine‐glutamate. When the sequence position of these charged amino acids was reversed from what is normally observed in nature, triple helix stability and compositional purity were significantly reduced. We examine the effect of salt on triple helix stability and observe that increased salt concentration reduces the thermal stability of heterotrimers by an average of 5 °C, but does not disrupt helix assembly. It was also found that some highly positively charged homotrimers can be stabilized in the presence of phosphate anions.
HYSCORE and Davies ENDOR study of irradiated ultra high molecular weight polyethylene
Authors: Paganini Maria Cristina , Brunella Valentina , Chiesa Mario
Published: July 2012

Ultra high molecular weight polyethylene (UHMWPE) has been studied with different magnetic resonance techniques to elicit information on the nature and the location of radicals generated during high energy irradiation. Field swept electron paramagnetic resonance, pulsed Davies electron nuclear double resonance and hyperfine sublevel correlation spectroscopic measurements allowed extracting for the first time the full 1H hyperfine coupling tensors of the most abundant radical, i.e. a secondary alkyl radical and to ascertain the formation of allyl radicals in the first stages of the irradiation process. The 1H hyperfine coupling tensors are analogous to those reported for single crystal irradiated polyethylene, suggesting that radicals generated in UHMWPE are located in the crystalline region of the polymer. Copyright © 2012 John Wiley & Sons, Ltd.
Center‐out radial sampling with off‐resonant reconstruction for efficient and accurate localization of punctate and elongated paramagnetic structures
Authors: de Leeuw H. , Seevinck P. R. , Bakker C. J. G.
Published: July 2012

Accurate localization of interventional devices, for example, needles and brachytherapy seeds, is desired for interventional procedures. MRI is usually considered unsuitable for this purpose, as the induced signal voids and signal pile‐ups do not necessarily represent the exact location of the devices. Center‐out radial sampling with off‐resonance reception (co‐RASOR) has been shown to solve this problem by repositioning the signal pile‐up into the geometrical center of the interventional devices. However, the multiple acquisitions required for co‐RASOR resulted in a low efficiency and unsuitability for near real‐time interventional purposes. Herein, we aim to increase the efficiency of co‐RASOR by relying on multiple off‐resonance reconstructions of a single acquisition rather than on multiple acquisitions. The soundness of this approach is shown by demonstrating the equivalence of acquisition co‐RASOR and reconstruction co‐RASOR, both theoretically and experimentally. An algorithm is proposed and evaluated to obtain the geometric centers of the devices, while suppressing the background. This procedure is shown to be effective, in vitro as well as ex vivo, and to yield signal intensity increases in the order of 150–400% of the average signal, in the geometric center of a brachytherapy seed and a needle, respectively. The geometric accuracy of the resultant images is confirmed by computed tomography. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Cardiac screening investigations in adult‐onset progressive external ophthalmoplegia patients
Authors: Pfeffer Gerald , Mezei Michelle M.
Published: July 2012

Introduction: Patients with mitochondrial myopathies may develop cardiac complications such as cardiomyopathy and/or cardiac conduction defects. To identify these potentially life‐threatening and treatable conditions, it is common practice to screen patients intermittently with electrocardiography and echocardiography. The optimal time interval for such screening investigations is unknown. We developed this study to review our screening results in adult‐onset patients with progressive external ophthalmoplegia (PEO). Methods: This study was a retrospective review of PEO patients with 5 years or more of cardiac screening investigations who did not have any cardiac symptoms. Results: Fifteen patients were included, and cardiomyopathy was identified on screening echocardiogram in 1 patient. Four patients had other abnormalities identified, which were unrelated to their mitochondrial myopathy. Conclusions: Only 1 patient in 15 developed cardiac complications related to mitochondrial disease during 5 years of follow‐up. We suggest that a screening interval of 3–5 years is probably appropriate for adult‐onset PEO patients who do not have cardiac symptoms. Muscle Nerve 60: 608–611, 2012
Weakest‐link attacker‐defender games with multiple attack technologies
Authors: Arce Daniel G. , Kovenock Dan , Roberson Brian
Published: July 2012

In this article, we examine a model of terrorism that focuses on the tradeoffs facing a terrorist organization that has two qualitatively different attack modes at its disposal. The terrorist organization's objective is to successfully attack at least one target. Success for the target government is defined as defending all targets from any and all attacks. In this context, we examine how terrorist entities strategically utilize an efficient but discrete attack technology — e.g., suicide attacks — when a more conventional mode of attack is available, and the optimal anti‐terrorism measures.© 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
An iterative method based on equation decomposition for the fourth‐order singular perturbation problem
Authors: Han Houde , Huang Zhongyi , Zhang Shangyou
Published: July 2012

In this article, we propose an iterative method based on the equation decomposition technique (1) for the numerical solution of a singular perturbation problem of fourth‐order elliptic equation. At each step of the given method, we only need to solve a boundary value problem of second‐order elliptic equation and a second‐order singular perturbation problem. We prove that our approximate solution converges to the exact solution when the domain is a disc. Our numerical examples show the efficiency and accuracy of our method. Our iterative method works very well for singular perturbation problems, that is, the case of 0 < ε ≪ 1, and the convergence rate is very fast. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Adaptive characteristic finite element approximation of convection–diffusion optimal control problems
Authors: Fu Hongfei , Rui Hongxing
Published: July 2012

In this article, a characteristic finite element approximation of quadratic optimal control problems governed by linear convection–diffusion equations is given. We derive some a posteriori error estimates for both the control and the state approximations, where the control variable is constrained by pointwise inequality. The derived error estimators are then used as an error indicator to guide the mesh refinement. In this sense, they are very important in developing adaptive finite element algorithm for the optimal control problems. Finally, a numerical example is given to validate the efficiency and reliability of the theoretical results. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Preparation of polyaniline grafted multiwalled carbon nanotubes and conductive application in polyetherimide
Authors: Li Xiaohu , Du Zhongjie , Zhang Chen , Li Hangquan , Zou Wei
Published: July 2012

A methodology for improving antistatic property of polyetherimide (PEI) composite using polyaniline (PANI) grafted multi‐walled carbon nanotubes (MWNTs) as conductive medium was proposed. First, the MWNTs grafted with PANI (PANI‐g‐MWNTs) were prepared by in‐situ polymerization in an emulsion system. Subsequently, PANI‐g‐MWNTs were blended with PEI using N‐methyl‐2‐pyrrolidone as solvent. After removing the solvent, the PEI/PANI‐g‐MWNT composite was prepared. As assisted conductive medium, the grafted PANI molecular chains on MWNT surface were dispersed in the PEI matrix to decrease the percolation value of the antistatic composites. The structure and morphology of PANI‐g‐MWNTs were characterized by Fourier transform infrared spectroscopy, transmission electron microscope, thermogravimetric analysis, and X‐ray powder diffraction, respectively. The dispersion of PANI‐g‐MWNTs in PEI matrix was studied by scanning electron microscope. The electrical performance was characterized by highly resistant meter. The volume resistivity of the conductivity percolation threshold was 1.781 × 10−8 S/cm when the loading of PANI‐g‐MWNTs was 1.0 wt%. The conductivity of PANI‐g‐MWNTs/PEI composites was found to be higher than that of pristine MWNTs/PEI composite. Copyright © 2012 John Wiley & Sons, Ltd.
An integrated functional genomics approach identifies the regulatory network directed by brachyury (T) in chordoma
Authors: Nelson Andrew C , Pillay Nischalan , Henderson Stephen , Presneau Nadège , Tirabosco Roberto , Halai Dina , Berisha Fitim , Flicek Paul , Stemple Derek L , Stern Claudio D , Wardle Fiona C , Flanagan Adrienne M
Published: July 2012

Chordoma is a rare malignant tumour of bone, the molecular marker of which is the expression of the transcription factor, brachyury. Having recently demonstrated that silencing brachyury induces growth arrest in a chordoma cell line, we now seek to identify its downstream target genes. Here we use an integrated functional genomics approach involving shRNA‐mediated brachyury knockdown, gene expression microarray, ChIP‐seq experiments, and bioinformatics analysis to achieve this goal. We confirm that the T‐box binding motif of human brachyury is identical to that found in mouse, Xenopus, and zebrafish development, and that brachyury acts primarily as an activator of transcription. Using human chordoma samples for validation purposes, we show that brachyury binds 99 direct targets and indirectly influences the expression of 64 other genes, thereby acting as a master regulator of an elaborate oncogenic transcriptional network encompassing diverse signalling pathways including components of the cell cycle, and extracellular matrix components. Given the wide repertoire of its active binding and the relative specific localization of brachyury to the tumour cells, we propose that an RNA interference‐based gene therapy approach is a plausible therapeutic avenue worthy of investigation. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Detection rates of clinically significant genomic alterations by microarray analysis for specific anomalies detected by ultrasound
Authors: Shaffer Lisa G. , Rosenfeld Jill A. , Dabell Mindy P. , Coppinger Justine , Bandholz Anne M. , Ellison Jay W. , Ravnan J. Britt , Torchia Beth S. , Ballif Blake C. , Fisher Allan J.
Published: July 2012

Objective

The aim of this study is to understand the diagnostic utility of comparative genomic hybridization (CGH)‐based microarrays for pregnancies with abnormal ultrasound findings.

Methods

We performed a retrospective analysis of 2858 pregnancies with abnormal ultrasounds and normal karyotypes (when performed) tested in our laboratory using CGH microarrays targeted to known chromosomal syndromes with later versions providing backbone coverage of the entire genome. Abnormalities were stratified according to organ system involvement. Detection rates for clinically significant findings among these categories were calculated.

Results

Clinically significant genomic alterations were identified in cases with a single ultrasound anomaly (n = 99/1773, 5.6%), anomalies in two or more organ systems (n = 77/808, 9.5%), isolated growth abnormalities (n = 2/76, 2.6%), and soft markers (n = 2/77, 2.6%). The following anomalies in isolation or with additional anomalies had particularly high detection rates: holoprosencephaly (n = 9/85, 10.6%), posterior fossa defects (n = 21/144, 14.6%), skeletal anomalies (n = 15/140, 10.7%), ventricular septal defect (n = 14/132, 10.6%), hypoplastic left heart (n = 11/68, 16.2%), and cleft lip/palate (n = 14/136, 10.3%).

Conclusions

Microarray analysis identified clinically significant genomic alterations in 6.5% of cases with one or more abnormal ultrasound findings; the majority were below the resolution of karyotyping. Larger data sets such as this allow for sub‐stratification by specific anomalies to determine risks for genomic alterations detectable by microarray analysis. © 2012 John Wiley & Sons, Ltd.
Experimental improvement of preparation of acrylic acid‐modified middle deacetylated chitosan and its application in absorbing paraquat
Authors: Hsu Shih‐Tong , Chen Lung‐Chuan , Leu Min‐Her , Hsiao Wen‐Feng , Lee Wen‐Ya , Pan Ting‐Chung
Published: July 2012

Chitosan with 45% deacetylation (CS45) grafted poly (acrylic acid) (CS45‐g‐PAA) was synthesized and characterized as an adsorbent of paraquat. CS45‐g‐PAA copolymers were prepared using H2O2(aq) as an initiator and NH4OH(aq) as a promoter. The highest grafting percentage of 44.2% was obtained using the traditional kinetic method. However, a maximum grafting percentage of 52.6% was calculated for the central composite design (CCD). Experimental results based on the reaction conditions that were predicted from the CCD are consistent with theoretical calculations. The grafted copolymer was characterized by FTIR, BET, and SEM. A representative CS45‐g‐PAA copolymer was hydrolyzed to a salt type (CS45‐g‐PANa) and used in the adsorption of paraquat. The adsorption equilibrium data correlate more closely with the Langmuir isotherm than with the Freundlich equation. The maximum adsorption capacity of CS45‐g‐PANa is 396.7 mg/g‐adsorbent. This value clearly exceeds that of Fuller's earth and the activated carbon which is the most commonly used binding agent for paraquat. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Synthesis and characterization of novel poly(butylene succinate)‐based copolyesters designed as potential candidates for soft tissue engineering
Authors: Gigli Matteo , Lotti Nadia , Gazzano Massimo , Finelli Lara , Munari Andrea
Published: July 2012

Poly(butylene succinate/diglycolate) copolymers by reactive blending were subjected to molecular and solid‐state characterization to study the effects of transesterification reactions. 13C‐nuclear magnetic resonance analysis evidenced the formation of block copolymers. Thermal measurements showed that all the samples were semicrystalline, with a soft amorphous phase and a rigid crystal phase. Wide‐angle x‐ray diffraction measurements indicated that the copolymers are characterized by cocrystallization. The mechanical properties were found related to crystallinity degree. The random copolymer, characterized by the lowest crystallinity degree, exhibits the lowest elastic modulus and the highest deformation at break. Therefore, solid‐state properties of poly(butylene succinate/diglycolate) copolymers can be tailored by acting on the molecular architecture. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Various polycarbonate graft copolymers via diels–alder click reaction
Authors: Dag Aydan , Aydin Mehtap , Durmaz Hakan , Hizal Gurkan , Tunca Umit
Published: July 2012

In this work, we used Diels–Alder click reaction for the preparation of various types of aliphatic polycarbonates (PCs). We first prepared a novel anthracene‐functionalized cyclic carbonate monomer, anthracen‐9‐ylmethyl 5‐methyl‐2‐oxo‐1,3‐dioxane‐5‐carboxylate (2), followed by ring‐opening polymerization of this monomer to prepare PC with pendant anthracene groups (PC‐anthracene) using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU)/1‐(3,5‐bis(trifloromethyl)phenyl)‐3‐cyclohexylthiourea (TU) as the catalyst and benzyl alcohol as the initiator in CH2Cl2 at room temperature. Subsequently, the resulting PC‐anthracene (Mn,TDGPC = 6000 g/mol, Mw/Mn = 1.22) was grafted with a linear α‐furan protected‐maleimide terminated‐poly(methyl methacrylate) (PMMA‐MI) (Mn,GPC = 3100 g/mol, Mw/Mn = 1.31), or poly(ethylene glycol) (PEG‐MI) (Mn,GPC = 550 g/mol, Mw/Mn = 1.09), or a mixture of PMMA‐MI and PEG‐MI to yield well‐defined PC graft or hetero graft copolymers, PC‐g‐PMMA (Mn,TDGPC = 59000 g/mol, Mw/Mn = 1.22) or PC‐g‐PEG, or PC‐g‐(PMMA)‐co‐PC‐g‐(PEG) (Mn,TDGPC = 39900 g/mol, Mw/Mn = 1.16), respectively, using Diels–Alder click reaction in toluene at 110°C. The Diels–Alder grafting efficiencies were found to be over 97% using UV spectroscopy. Moreover, the structural analyses and the molecular weights of resulting graft copolymers were determined via 1H NMR and triple detection GPC (TD‐GPC), respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Particle and breath figure formation of triblock copolymers having self‐complementary hydrogen‐bonding units
Authors: Park Nojin , Seo Myungeun , Kim Sang Youl
Published: July 2012

Novel triblock copolymers having self‐complementary hydrogen‐bonding units were synthesized by using reversible addition–fragmentation transfer polymerization. As characterized by dynamic light scattering and atomic force microscopy, these polymers formed noncovalently crosslinked polymer particles and showed an aggregation behavior by intermolecular and intramolecular interactions. At low concentration, polymers formed nanoparticles, and the particle diameter increased with increasing polymer concentration. Well‐ordered hexagonal microstructures were prepared by “Breath Figure” technique with the triblock copolymers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Affective state and cognitive functioning in patients with intracranial tumors: validity of the neuropsychological baseline assessment
Authors: Goebel Simone , Kaup Lea , Wiesner Christian D. , Mehdorn H. Maximilian
Published: July 2012

Objectives

The aim of this paper is to investigate the relationship between the affective and cognitive states of neurooncological patients prior to the neurosurgical treatment to assess associations between distress levels and neuropsychological test performance in this sample and setting.

Methods

The prospective study population consists of 172 patients. Patients were studied preoperatively with a comprehensive test battery consisting of a variety of affective and cognitive measures. Psychological instruments included the Hospital Anxiety and Depression Scale, the Amsterdam Preoperative Anxiety and Information Scale, and the Acute Stress Disorder Scale.

Results

Factor analysis revealed two factors representing subjective affective functioning: whereas one reflects the patients' more general emotional state (Hospital Anxiety and Depression Scale, Acute Stress Disorder Scale), the second reflects anxiety specifically related to the neurosurgical procedure (Amsterdam Preoperative Anxiety and Information Scale). After age and education have been accounted for via linear regression analyses, affect did not contribute to cognitive performance in any of the cognitive domains in the whole patient sample. However, in patients with extreme levels of psychiatric morbidity, there was evidence for distinct cognitive morbidity consistent with previous research.

Conclusions

Our results suggest that, for a large variety of widely used neuropsychological measures and for most neurooncological patients, the preoperative neuropsychological baseline assessment can be considered valid and dependable. In patients with extreme levels of distress, however, distinct cognitive domains might be differentially affected. Copyright © 2012 John Wiley & Sons, Ltd.
NH2 and NH Surface Production in Pulsed NH3 Plasmas on TiO2: A Steady‐State Probe of Short Pulse Plasmas
Authors: Pulsipher Daniel J. V. , Fisher Ellen R.
Published: July 2012

Understanding the gas‐phase and surface chemistry of NHx species in pulsed NH3 plasmas can lead to optimized plasma conditions for nitriding metal oxide surfaces such as TiO2. Gas‐phase densities and surface reactions of NH and NH2 in pulsed NH3 plasmas used to nitride TiO2 surfaces were explored by systematically varying peak plasma power and pulsing duty cycle. Results from laser induced fluorescence and optical emission spectroscopy studies reveal interconnected trends of gas‐phase densities and surface reactions. Divergent trends in NH, NH2 Hα, Hγ, N, and N densities found in short pulse plasmas are explained by plasma pulse initiation and afterglow effects. NH2 and NH surface scatter coefficients were measured with the imaging of radicals interacting with surfaces technique as a function of plasma parameters, including pulse sequence. Results show NHx species primarily scatter off of TiO2 and are correlated to NH gas phase densities.

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Size and quality control of fast grown CdS quantum dots
Authors: Fregnaux Mathieu , Dalmasso Stéphane , Gaumet Jean‐Jacques , Laurenti Jean‐Pierre
Published: July 2012

The synthesis of high quality II‐VI semiconductor quantum dots (QDs) is fundamental for developing new devices in several applications such as biomarkers, solar cells or blue‐UV lasers. These emerging technologies are funded on the size‐dependent optical properties of the QDs. Consequently, it is a crucial aspect to get insight into different ways for syntheses of their nanosized particles. In this work, we use two different QD elaboration methods: (i) a single source precursor thermal growth methodology and (ii) a microwave synthetic route. Using both protocols, high quality small QDs (Ø < 5 nm) are produced. Both growing techniques offer the advantage to be simple and fast: 2 hours (i) and less than 25 minutes (ii) in duration, growth temperatures do not exceed 280 °C. For both elaboration procedures, we report a unique physics/chemistry cross‐disciplinary study on these small size QDs: mass spectrometry (MS) technique provides background data about composition, size and stability of particles; crystalline structure and size distribution of the QDs are obtained from X‐ray diffraction (XRD) and transmission electron microscopy (TEM); room temperature (RT) optical spectrometry of nanodispersions – photoluminescence (PL) and absorption – reveals quantum size effects. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flexible recalibration of binary clinical prediction models
Authors: Dalton Jarrod E.
Published: July 2012

Calibration in binary prediction models, that is, the agreement between model predictions and observed outcomes, is an important aspect of assessing the models' utility for characterizing risk in future data. A popular technique for assessing model calibration first proposed by D. R. Cox in 1958 involves fitting a logistic model incorporating an intercept and a slope coefficient for the logit of the estimated probability of the outcome; good calibration is evident if these parameters do not appreciably differ from 0 and 1, respectively. However, in practice, the form of miscalibration may sometimes be more complicated. In this article, we expand the Cox calibration model to allow for more general parameterizations and derive a relative measure of miscalibration between two competing models from this more flexible model. We present an example implementation using data from the US Agency for Healthcare Research and Quality. Copyright © 2012 John Wiley & Sons, Ltd.
Acute spill‐mimicking exposure effect of hexavalent chromium on the pituitary‐ovarian axis of a teleost, Channa punctatus (Bloch)
Authors: Mishra Ashish K. , Mohanty Banalata
Published: July 2012

Acute exposure to hexavalent chromium (as 10, 20, and 40 mg/L potassium dichromate for 96 h) adversely affected the pituitary‐ovarian axis of a teleost Channa punctatus. The toxic impact of metal exposure on fish ovary was revealed in the form of increased percentage of atretic follicles, significantly in 20 mg/L and 40 mg/L exposure groups. The follicular atresia mostly occurred in vitellogenic (stage II and stage III) oocytes. Reduction of serum level of 17β‐estradiol was also significant in 20 mg/L and 40 mg/L exposure groups. The increase of LH‐immunointensity of pituitary gonadotrophs (LHβ‐immunoreactive cells) and their hypertrophy was evident, significantly in fish of 40 mg/L exposed group. Thus, the present acute metal spill‐mimicking laboratory study clearly demonstrated that short‐term exposures to high doses of hexavalent chromium may disrupt reproduction of the fish and affect their population. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 733–739, 2014.
A Homochiral Metal‐Dipeptide Supramolecular Framework Including a Hydrogen‐bonded Guest Network of Water and Uncoordinated 4, 4′‐Bipyridine
Authors: Lou Benyong , Huang Xiaodong
Published: July 2012

Abstract. The self‐assembly of glycyl‐L‐leucine, Cu(NO3)2·3H2O and 4, 4′‐bipyridine resulted in the tetranuclear‐based metal‐dipeptide supramolecular framework [Cu4(C8H14N2O3)4(H2O)2(C10H8N2)2]·(C10H8N2)·13H2O (1). In the structure, the 4, 4′‐bipyridine‐bridged tetranuclear complex of CuII‐glycyl‐L‐leucine interacts with each other to form a 1D hydrogen‐bonded chain including uncoordinated 4, 4′‐bipyridine and an interesting water chain in different channels. Under similar reaction conditions, racemic glycyl‐D,L‐leucine gave rise to the centrosymmetric dinuclear complex [Cu2(C8H14N2O3)2(C10H8N2)]·2H2O (2), which is linked into a 2D hydrogen‐bonded structure without 4, 4′‐bipyridine included.
Crystal Structure and Electronic Structure of Red SnO
Authors: Köhler Jürgen , Tong Jianwei , Dinnebier Robert , Simon Arndt
Published: July 2012

Pigeon blood red powder samples of SnO were synthesized via a soft chemistry route. A precipitate was obtained from a freshly prepared SnCl2 solution containing phosphorus acid by adding ammonia until a pH value of 4.9 is reached. Heating of the mixture at 95 °C leads after 5 d to microcrystalline powders of red SnO. The crystal structure was solved and refined from X‐ray powder diffraction data (Cmc21; a = 5.0045(3) Å, b = 5.7457(3) Å, c = 11.0485(5) Å, Z = 8). Red SnO crystallizes in a new structure type. Characteristic building units are double layers of tin and oxygen atoms. The tin atoms are surrounded by four oxygen atoms with distances ranging from 2.04 Å to 2.67 Å, and the highly asymmetric coordination around the Sn2+ ions indicates the presence of a stereochemically active lone pair. LMTO band structure calculations show that the red modification of SnO is an insulator. The electronic structures of red SnO and the zero band gap semiconductor black SnO are compared. The lone pairs of the tin atoms are visualized via the electron localization function.
Robust preparative-scale extracellular production of hirudin in Escherichia coli and its purification and characterization
Authors: Huang Cuicui , Zhang Xuerui , Qu Jia , Zhang Ping , Tan Shuhua
Published: July 2012

Hirudin variant III (HV3) is potentially useful in the prevention and treatment of cataracts. To prepare sufficient amounts of rHV3 for further preclinical studies, we developed an effective process for robust preparative-scale extracellular production of rHV3 in Escherichia coli. In a 7-l bioreactor, under the optimal fed-batch fermentation conditions, rHV3 was excreted into the culture supernatant and yielded up to 915 mg l−1. Then, a four-step purification procedure was applied to the product, which included ultrafiltration, hydrophobic chromatography, anion-exchange chromatography, and preparative reversed-phase fast protein liquid chromatography (FPLC). The overall maximum recovery attained was 56 %, the purity reached at least 99 % as evaluated by HPLC analysis, the molecular weight was determined to be 7,011.10 Da by matrix-assisted laser-desorption time-of-flight mass spectrometry (MALDI-TOF/MS) analysis, and the pI was 4.46 as analyzed by isoelectric focusing. The N- and C-terminal sequence analysis confirmed the product homogeneity. The final product contained at most 10 pg of residual DNA per dose (0.2 mg) of rHV3 by high-sensitivity hybridization assay and at most 3 EU endotoxin protein/mg by limulus amebocyte lysate assay. Taken together, the rHV3 produced in multigram quantities in E. coli by this bioprocess meets the regulatory criteria for biopharmaceuticals and can be used as a drug candidate for preclinical studies.
Three-dimensional flow in circular cavities of large spanwise aspect ratio
Authors: Tutty Owen , Savelsberg Ralph , Castro Ian P.
Published: July 2012

Experimental data are presented for the vortex flow in a nominally two-dimensional circular cavity. The vortex is driven by a separated shear layer along an open section of the cavity circumference. It is shown that the core vortex flow is perturbed three-dimensionally. An inviscid analysis of an ideal core (solid body) vortex is given and it is shown that this flow contains a steady perturbation whose characteristics are almost exactly those identified in the experiments. Viscous effects reduce (by a few per cent) the spanwise wavelength of the perturbation and also lead, via spatial variations in Reynolds stress, to a modification of the core flow so that the radial profile of the circumferential velocity is ‘S’-shaped, rather than linear.
Rule Creation in a Political Hierarchy
Authors: CARRUBBA CLIFFORD J. , CLARK TOM S.
Published: July 2012

Principal-agent relations are replete in politics; politicians are agents of electorates, bureaucrats are agents of executives, lower courts are agents of upper courts, and much more. Commonly, principals are modeled as the rule-making body and agents as the rule-implementing body. However, principals often delegate the authority to make the rules themselves to their agents. The relationship between the lower federal courts and the Supreme Court is one such example; a considerable portion of the law (rules) is made in the lower federal courts with the Supreme Court serving primarily as the overseer of those lower courts’ decisions. In this article, we develop and test a principal-agent model of law (rule) creation in a judicial hierarchy. The model yields new insights about the relationship among various features of the judicial hierarchy that run against many existing perceptions. For example, we find a non-monotonic relationship between the divergence in upper and lower court preferences over rules and the likelihood of review and reversal by the Supreme Court. The empirical evidence supports these derived relationships. Wider implications for the principal-agent literature are also discussed.
Losing the Waterways: The Displacement of Khmer Communities from the Freshwater Rivers of the Mekong Delta, 1945–2010
Authors: TAYLOR PHILIP
Published: July 2012

In the latter half of the twentieth century thousands of Khmer people were displaced from their homes along the freshwater rivers of Vietnam's Mekong delta. Their pattern of settlement along freshwater tidal rivers was an ecological adaptation unique in the Khmer-speaking world, of which only vestiges remain. Drawing upon oral histories and ethnographic observations of O Mon, a district in the central Mekong delta, this paper reconstructs a picture of the traditional river-based livelihoods, social structure and religious life of Khmers in this region in the 1940s. It describes how these Khmers were driven from their villages early in the First Indochina War. Experiencing ongoing dislocations in subsequent periods of war and peace, most have been prevented from returning to their former homes or reclaiming their land. Relying on testimony by elderly Khmers, who witnessed the disintegration of their riverside communities, the account challenges existing depictions of the ecology and history of the Mekong delta, offering new insights into the complexity of the Indochina wars and the severity of their consequences.
Walking with lions: why there is no role for captive-origin lions Panthera leo in species restoration
Authors: Hunter Luke T.B. , White Paula , Henschel Philipp , Frank Laurence , Burton Cole , Loveridge Andrew , Balme Guy , Breitenmoser Christine , Breitenmoser Urs
Published: July 2012

Despite formidable challenges and few successes in reintroducing large cats from captivity to the wild, the release of captives has widespread support from the general public and local governments, and continues to occur ad hoc. Commercial so-called lion Panthera leo encounter operations in Africa exemplify the issue, in which the captive breeding of the lion is linked to claims of reintroduction and broader conservation outcomes. In this article we assess the capacity of such programmes to contribute to in situ lion conservation. By highlighting the availability of wild founders, the unsuitability of captive lions for release and the evidence-based success of wild–wild lion translocations, we show that captive-origin lions have no role in species restoration. We also argue that approaches to reintroduction exemplified by the lion encounter industry do not address the reasons for the decline of lions in situ, nor do they represent a model that can be widely applied to restoration of threatened felids elsewhere.
Selling Gasoline with a Smile: Gas Station Attendants between the United States, Italy, and the Third World, 1945–1970
Authors: Bini Elisabetta
Published: July 2012

This article analyzes the ways in which Esso Standard Italiana, the Italian affiliate of Standard Oil (New Jersey), and the state-owned firmAzienda Generale Italiana Petroli(Italian General Oil Company, Agip), redefined the job of gas station attendants in post-war Italy. It argues that, drawing on US scientific management and marketing, the two companies advanced a new understanding of masculinity and class. They promoted the idea that gas station attendants should distance themselves from the forms of male working-class identity that were associated with mechanical work and combine technical expertise with the ability to market products by relying on appearance. It shows how during the 1960s Agip exported such Americanized business practices to the developing world, by organizing a series of training courses for gas station attendants from North Africa and sub-Saharan Africa. This article looks in turn at how attendants challenged the two companies' efforts to standardize and rationalize their services by joining trade associations and organizing strikes, in the name of their rights as shopkeepers and small businessmen.
The Return of Merchant Capitalism
Authors: Lichtenstein Nelson
Published: July 2012

To understand the economic character, transnational politics, and labor regime characteristic of contemporary globalization, it is useful to revisit the concept of “merchant capitalism,” a form of market exchange that dominated trade in the eighteenth and early nineteenth centuries. Then as now, commodities proved crucial to world commerce, merchants held the whip hand over manufacturers, while workers found their remuneration and working conditions subject to competitive pressures that often debased their status. The transnational retailers who today dominate so many global supply chains therefore play many of the same roles as did the antebellum merchants of New York and Liverpool who favored free trade and formed an alliance with those who deployed unfree labor to grow the cotton and other commodities upon which the trading system of their day was built.
Embodying Labor, Then and Now
Authors: Wolkowitz Carol
Published: July 2012

In her introduction to the new edition ofWomen on the Line, first published in 1982, Miriam Glucksmann notes that it had been written well before the body and embodiment had become an explicit focus of studies of work and employment. However, rereadingWomen on the Linereminds us that ethnographers have long paid attention to the embodied aspects of work, although few of them have written about them as eloquently as Glucksmann. In the original volume she was able to articulate how it felt to experience herself in relation to her environment, a phenomenological perspective made possible by her adoption of an autoethnographic writing style (a strategy linked to her rejection both of a narrowly academic approach and, in consequence, of the disembodied authorial voice that tended to go with it). Perhaps another reason why Glucksmann was able to write about her working on the line with such sensitivity to the embodiment of the experience is that she was new to assembly line work, so the embodied routines of factory life had not yet been submerged below the level of conscious articulation. It is useful therefore to summarize what she had to say and to think about how we can build on it.
SEMIPARAMETRIC STRUCTURAL MODELS OF BINARY RESPONSE: SHAPE RESTRICTIONS AND PARTIAL IDENTIFICATION
Authors: Chesher Andrew
Published: July 2012

I study the partial identifying power of structural single-equation threshold-crossing models for binary responses when explanatory variables may be endogenous. The sharp identified set of threshold functions is derived for the case in which explanatory variables are discrete, and I provide a constructive proof of sharpness. There is special attention to a widely employed semiparametric shape restriction, which requires the threshold-crossing function to be a monotone function of a linear index involving the observable explanatory variables. The restriction brings great computational benefits, allowing calculation of the identified set of index coefficients without calculating the nonparametrically specified threshold function. With the restriction in place, the methods of the paper can be applied to produce identified sets in a class of binary response models with mismeasured explanatory variables.
WALD TESTS FOR DETECTING MULTIPLE STRUCTURAL CHANGES IN PERSISTENCE
Authors: Kejriwal Mohitosh , Perron Pierre , Zhou Jing
Published: July 2012

This paper considers the problem of testing for multiple structural changes in the persistence of a univariate time series. We propose sup-Wald tests of the null hypothesis that the process has an autoregressive unit root throughout the sample against the alternative hypothesis that the process alternates between stationary and unit root regimes. We derive the limit distributions of the tests under the null and establish their consistency under the relevant alternatives. We further show that the tests are inconsistent when directed against the incorrect alternative, thereby enabling identification of the nature of persistence in the initial regime. We also propose hybrid testing procedures that allow ruling out of stable stationary processes or ones that are subject to only stationary changes under the null, thereby aiding the researcher in interpreting a rejection as emanating from a switch between a unit root and stationary regime. The computation of the test statistics as well as asymptotic critical values is facilitated by the dynamic programming algorithm proposed in Perron and Qu (2006, Journal of Econometrics134, 373–399) which allows imposing within- and cross-regime restrictions on the parameters. Finally, we present Monte Carlo evidence to show that the proposed procedures perform well in finite samples relative to those available in the literature.
SECOND-ORDER REFINEMENT OF EMPIRICAL LIKELIHOOD FOR TESTING OVERIDENTIFYING RESTRICTIONS
Authors: Matsushita Yukitoshi , Otsu Taisuke
Published: July 2012

This paper studies second-order properties of the empirical likelihood overidentifying restriction test to check the validity of moment condition models. We show that the empirical likelihood test is Bartlett correctable and suggest second-order refinement methods for the test based on the empirical Bartlett correction and adjusted empirical likelihood. Our second-order analysis supplements the one in Chen and Cui (2007, Journal of Econometrics141, 492–516) who considered parameter hypothesis testing for overidentified models. In simulation studies we find that the empirical Bartlett correction and adjusted empirical likelihood assisted by bootstrapping provide reasonable improvements for the properties of the null rejection probabilities.