bluuebunny/crossref_metadata_2025 huggingface dataset:
A Pilot Study in Odontochronology for the Pig Domestication Question in North‐Central China
Authors: Pike‐Tay Anne , Ma Xiaolin
Published: September 2011

In this paper, we report results of the pilot study in which we apply skeletochronological analysis of teeth to a collection of modern Chinese wild boar (Sus scrofa)of known age and date of death. This is the first time that odontochronology has been applied to suids in China. This work allowed us to establish parameters for subsequent analysis of a limited number of Neolithic‐agedSus(wild boar and possible early domesticated pig) samples from Henan Province. The goal of the research is to contribute to the ongoing reconstruction of Neolithic dietary, health and economic patterns along the Yellow River. Our results are encouraging in that regular seasonal growth patterning is observed in the northern control sample, which is from the same region as our archaeological investigation. Copyright © 2011 John Wiley & Sons, Ltd.
Continuation from a flat to a round Earth model in the coplanar orbit transfer problem
Authors: Cerf Max , Haberkorn Thomas , Trélat Emmanuel
Published: September 2011

In this article, we focus on the problem of minimization of the fuel consumption for the coplanar orbit transfer problem. This problem is usually solved numerically by a shooting method, based on the application of the Pontryagin Maximum Principle; however, the shooting method is known to be hard to initialize, and the convergence is difficult to obtain because of discontinuities of the optimal control. Several methods are known in order to overcome that problem; however, in this article, we introduce a new approach based on the following preliminary remark. When considering a 2D flat Earth model with constant gravity, the optimal control problem of passing from an initial configuration to some final configuration by minimizing the fuel consumption can be very efficiently solved, and the solution leads to a very efficient algorithm. Based on that, we propose a continuous deformation from this flat Earth model to a modified flat Earth model that is diffeomorphic to the usual round Earth model. The resulting numerical continuation process thus provides a new way to solve the problem of minimization of the fuel consumption for the coplanar orbit transfer problem. Copyright © 2011 John Wiley & Sons, Ltd.
STRUCTURES AND STRATEGIES IN RELATIONSHIPS BETWEEN NON‐GOVERNMENT SERVICE PROVIDERS AND GOVERNMENTS
Authors: Batley Richard
Published: September 2011

This article analyses collaboration between governments and non‐governmental organisations (NGOs) in Bangladesh, India and Pakistan in three services: basic education, healthcare and sanitation. It questions the premise that NGOs that collaborate lose their autonomy and capacity for policy influence. It finds that, even where NGOs operate in constraining institutional environments and enter agreements with government, they are able to exercise strategic choices in response. Most of the studied NGOs depended on government for less than half their funding; they all had alternative sources and so could make strategic choices to some degree. Non‐government service providers are not passive in face of structural constraints. Although their strategies are not usually explicit, they balance the need for financial survival, the defence of their organisational identities and commitment to their goals—including influencing government. At least for these NGOs, there is no contradiction between advocacy and service delivery. Copyright © 2011 John Wiley & Sons, Ltd.
Properties of rubber filled with montmorillonite with various surface modifications
Authors: Hrachová Jana , Komadel Peter , Janigová Ivica , Šlouf Miroslav , Chodák Ivan
Published: September 2011

Layered silicate/natural rubber composites were prepared by direct polymer melt intercalation. Na‐montmorillonite Kunipia‐F and its organic derivates (organo‐clays) prepared by ion exchange were used as clay fillers. Silica (SiO2) Ultrasil VN3, a filler commonly used in the rubber industry, was used in combination with clay fillers. The effect of clay or organo‐clay loading from 1 up to 10 phr without (0 phr) or with silica (15 phr) showed significant improvement of the tensile properties (stress at break, strain at break and modulus M100). Modification of montmorillonite by three alkylammonium cations with the same length of alkylammonium chain (18 carbons) and different structure resulted in altered reinforcing and plasticizing effects of the filler in composites with rubber matrix. Copyright © 2011 John Wiley & Sons, Ltd.
Anoikis: an emerging hallmark in health and diseases
Authors: Taddei ML , Giannoni E , Fiaschi T , Chiarugi P
Published: September 2011

Anoikis is a programmed cell death occurring upon cell detachment from the correct extracellular matrix, thus disrupting integrin ligation. It is a critical mechanism in preventing dysplastic cell growth or attachment to an inappropriate matrix. Anoikis prevents detached epithelial cells from colonizing elsewhere and is thus essential for tissue homeostasis and development. As anchorage‐independent growth and epithelial–mesenchymal transition, two features associated with anoikis resistance, are crucial steps during tumour progression and metastatic spreading of cancer cells, anoikis deregulation has now evoked particular attention from the scientific community. The aim of this review is to analyse the molecular mechanisms governing both anoikis and anoikis resistance, focusing on their regulation in physiological processes, as well as in several diseases, including metastatic cancers, cardiovascular diseases and diabetes. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Screening and Determination for Potential α‐Glucosidase Inhibitors from Leaves of Acanthopanax senticosus Harms by Using UF‐LC/MS and ESI‐MSn
Authors: Zhou Hui , Xing Junpeng , Liu Shu , Song Fengrui , Cai Zongwei , Pi Zifeng , Liu Zhiqiang , Liu Shuying
Published: September 2011

Introduction

Acanthopanax senticosus Harms is a typical Chinese herb with flavonoids existing in all parts of the plant but with the largest content in leaves. However, leaves have been neglected in past research. To investigate the potential use of leaves of A. senticosus Harms for discovering lead compounds to treat type 2 diabetes, the herb leaves were selected for screening the potential of α‐glucosidase inhibitors.

Objective

To screen for candidates of α‐glucosidase inhibitors from leaves of A. senticosus Harms and evaluate the structure–activity relationship of the α‐glucosidase inhibitors.

Methodology

Ultrafiltration liquid chromatography/mass spectrometry (UF‐LC/MS) assay was developed for screening candidates of α‐glucosidase inhibitors from leaves of A. senticosus Harms. The interesting compounds were identified by using reversed‐phase high performance liquid chromatography with diode array detector and electrospray ionisation multiple‐stage tandem mass spectrometry (RP‐HPLC‐DAD‐ESI‐MSn), and confirmed by using electrospray ionisation Fourier transform ion cyclotron resonance multiple‐stage tandem mass spectrometry (ESI‐FT‐ICR‐MSn). Furthermore, the α‐glucosidase inhibitory activity of the compounds detected was estimated using in vitro assays.

Results

Eight compounds that might bind to α‐glucosidase were screened and seven of them were identified successfully. The α‐glucosidase inhibitory activity of the related compounds in leaves of A. senticosus Harms was determined.

Conclusion

The results obtained provided new information for the discovery of potential α‐glucosidase inhibitors and the potential anti‐diabetic application of the leaves of A. senticosus Harms. Copyright © 2011 John Wiley & Sons, Ltd.
Evolving practicum issues in school psychology preparation
Authors: Li Chieh , Fiorello Catherine A.
Published: September 2011

Practicum experiences have been a critical aspect of the education and training of school psychologists at both the specialist and doctoral level. At the specialist level, the National Association of School Psychologists recently updated their standards for practicum, but the content, quality, and length of practicum vary tremendously across training programs. At the doctoral level, recent guidelines from the Association of State and Provincial Psychology Boards allow for the emerging option to include practicum experience together with internship toward licensure requirements. However, this raises a number of questions unique to the context of school psychology training, including what hours and activities count, appropriate credentials for supervisors, appropriate sites for practicum experiences, what competencies are to be gained, and how to assess those competencies. The Council of Directors of School Psychology Programs has organized a task force to address issues of competencies and supervision in practicum experiences to inform recommendations and regulations regarding practicum experiences. This article summarizes the nature and context of these issues, and makes recommendations for school psychology training programs, national professional organizations, and credentialing organizations. © 2011 Wiley Periodicals, Inc.
Metabolomic analysis of a synthetic metabolic switch inStreptomyces coelicolorA3(2)
Authors: Jankevics Andris , Merlo M. Elena , de Vries Marcel , Vonk Roel J. , Takano Eriko , Breitling Rainer
Published: September 2011

The global analysis of metabolism by liquid chromatography coupled to mass spectrometry is often hampered by a large amount of biological and technical variability. Here, we introduce an experimental and analytical strategy that can produce robust metabolome profiles in the face of this challenge. By applying a new computational approach based on concordance analysis to an extremely large number of analytical replicates, we are able to show that the overexpression of an antisense non‐coding RNA targeting glutamine synthetase I results in a major reorganization of the metabolism ofStreptomyces coelicolor, the model species of antibiotic‐producing bacteria. We identified 97 metabolites with statistically significant reproducible dynamic behavior across the time series. The observed metabolic changes are very rapid, specific and widespread across metabolism, but focus on the nitrogen assimilation pathways. Our results demonstrate the power of highly replicated experimental designs for the robust characterization of metabolite dynamics. The identified global rearrangement of metabolism suggests the usefulness of RNA interference as an efficient strategy to manipulate the physiology of bacteria with wider biotechnological applicability in microorganisms.
Ionic liquid functionalized polylactide by cationic polymerization: Synthesis and stabilization of carbon nanotube suspensions
Authors: Biedroń Tadeusz , Pietrzak Łukasz , Kubisa Przemysław
Published: September 2011

Medium molecular weight poly(L,L‐lactide)s (PLA) containing at one chain end ionic group derived from imidazolium ionic liquid (IL) were synthesized by cationic polymerization using hydroxylated IL as initiator. matrix assisted laser desorption/ionization time‐of‐flight analysis confirmed the structure of products (PLA‐IL). Carbon nanotubes (CNT) were dispersed in solution of PLA‐IL in 1,4‐dioxane and significant improvement of stability of suspension was observed by measurements of suspension absorbance. Similar effect was, however, observed also for solutions of PLA which did not contain terminal IL group. CNT samples treated with PLA‐IL and PLA were isolated, thoroughly washed with 1,4‐dioxane and stability of suspensions was again measured. Sample treated with PLA after washing behave similarly to untreated CNT. Stability of suspension of CNT treated with PLA‐IL after washing was considerably higher than that of untreated CNT and the presence of polymer bound to CNT was clearly detectable in scanning electron microscopy images. Results indicate that there is indeed an interaction between end‐group derived from IL and CNT surface as postulated earlier but to observe solely this effect an excess of polymer should be removed, otherwise factors such as increase of viscosity of solution or weak interactions of PLA ester groups with CNT may obscure results. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Single‐chain nanoparticles with well‐defined structure via intramolecular crosslinking of linear polymers with pendant benzoxazine groups
Authors: Wang Peng , Pu Hongting , Jin Ming
Published: September 2011

Controlled intramolecular collapse of linear polymer chains with crosslinkable groups is an efficient way to prepare single‐chain nanoparticles in the size range of 5–20 nm. However, the nature of the crosslinking group is critical. In present study, poly(styrene‐co‐chloromethyl styrene) [P(St‐co‐CMS)] was synthesized via reversible addition‐fragmentation chain transfer (RAFT) polymerization and then was converted into polystyrene azide (PSN3). Polystyrene containing benzoxazine side groups [P(St‐co‐BS)], which can be used as the precusor for the later intramolecular collapse, was obtained from PSN3 and 3‐(4‐(prop‐2‐ynyloxy)phenyl)‐3,4‐dihydro‐2H‐benzo[e][1,3]oxazine (P‐APPE) via the method of click chemistry. The sub‐20 nm polymeric nanoparticles with well‐defined structure via thermally intramolecular crosslinking of P(St‐co‐BS) were prepared. The structure change from the linear polymers to the single‐chain nanoparticles was confirmed by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography (GPC). The morphology and the dimension of the nanoparticles were characterized by using transmission electron microscope (TEM), atomic force microscopy (AFM), as well as dynamic light scattering (DLS). The results reveal that the size of the nanoparticles can be regulated by changing the molecular weight of the precursors and the amount of pendant benzoxazine groups by the use of controlled polymerization techniques. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Persistent impact of illness on families of adult survivors of childhood central nervous system tumors: a population‐based cohort study
Authors: Hovén Emma I. , Lannering Birgitta , Gustafsson Göran , Boman Krister K.
Published: September 2011

Objective

This study aims to determine the long‐term impact on families of adult survivors of childhood central nervous system tumors. Illness‐related family consequences were studied in relation to modifying determinants.

Methods

In a population‐based cohort of parents of 697 survivors 18 years and older, 551 parents provided data. The impact of cancer on the families was evaluated in four domains using the Impact on Family Scale (economic situation, personal burden, social life, sibling impact). The results were analyzed in relation to survivors' health assessed using the Health Utilities Index™, parent satisfaction with information about illness and treatment, and perceived health‐care needs of their child.

Results

Despite an established mild‐to‐moderate impact on the group level, outcomes provided evidence of substantial cancer‐related family consequences even once the child had reached adulthood. About one fifth of parents reported psychological and financial difficulties exceeding the cutoff limit for a significant impact still ≥5 years after diagnosis. A stronger total family impact was associated with poorer health of survivors (F[3,302] = 56.65, p < 0.001), and unmet informational ‐ (F[3,231] = 14.06, p < 0.001) and health‐care needs (t218 = 5.31, p < 0.001). The impact was unrelated to survivors' age at follow‐up and time since diagnosis.

Conclusions

Adverse cancer‐related consequences affect a considerable portion of families of childhood survivors of central nervous system tumor, even after reaching adulthood. The impact is aggravated by lasting sequelae and perceived shortcomings of long‐term follow‐up, factors that partly are avoidable. Improved clinical follow‐up should particularly address illness information and long‐term health‐care needs to reduce the impact on families of survivors suffering from chronic health conditions.

Copyright © 2011 John Wiley & Sons, Ltd.
A method for isolation and identification of urinary biomarkers in patients with diabetic nephropathy
Authors: Fisher Wayne G. , Lucas Jessica E. , Mehdi Uzma F. , Qunibi Danna W. , Garner Harold R. , Rosenblatt Kevin P. , Toto Robert D.
Published: September 2011

Purpose: The poor performance of current tests for predicting the onset, progression and treatment response of diabetic nephropathy has engendered a search for more sensitive and specific urinary biomarkers. Our goal was to develop a new method for protein biomarker discovery in urine from these patients.

Experimental design: We analyzed urine from normal subjects and patients with early and advanced nephropathy. Proteins were separated using a novel analysis process including immunodepletion of high‐abundance proteins followed by two‐stage LC fractionation of low‐abundance proteins. The proteins in the fractions were sequenced using MS/MS.

Results: Immunodepletion of selected high‐abundance proteins followed by two‐stage LC produced approximately 700 fractions, each less complex and more amenable to analysis than the mixture and requiring minimal processing for MS identification. Comparison of fractions between normal and diabetic nephropathy subjects revealed several low‐abundance proteins that reproducibly distinguished low glomerular filtration rate (GFR) from both high GFR diabetic and normal subjects, including uteroglobin, a protein previously associated with renal scarring.

Conclusions and clinical relevance: We developed a novel method to identify low‐abundance urinary proteins that enables the discovery of potential biomarkers to improve the diagnosis and management of patients with diabetic nephropathy.
Deposition of nanocrystalline diamond films on temperature sensitive substrates for infrared reflectance spectroscopy
Authors: Babchenko Oleg , Remes Zdenek , Izak Tibor , Rezek Bohuslav , Kromka Alexander
Published: September 2011

We report on the deposition of nanocrystalline diamond films onto protected aluminum/pyrex glass mirrors in focused or linear antenna microwave plasma enhanced chemical vapour deposition systems. Quality of the diamond films is characterized by Raman spectroscopy, scanning electron microscopy and optical images. The best material quality and coating uniformity is achieved in the linear antenna system. Infrared reflectance spectroscopy reveals enhanced reflection from the substrates prepared in the linear antenna system compared to diamond coatings prepared in common focused plasma system on protected aluminium/pyrex glass mirrors as well as on polished Si wafers. Linear antenna system diamond coatings are thus the most promising for spectroscopic characterization of molecular grafting to diamond.
High performance thin‐film transistors using moderately aligned semiconducting single‐wall carbon nanotubes
Authors: Fujii Shunjiro , Tanaka Takeshi , Nishiyama Satoko , Kataura Hiromichi
Published: September 2011

Thin‐film transistors (TFTs) using aligned network of semiconductor‐enriched single‐wall carbon nanotubes (s‐SWCNTs) were fabricated on a SiO2/Si substrate. The aligned thin film was prepared by N2 blow in the drying process using as separated s‐SWCNT solution prepared by the agarose gel chromatography. We demonstrated that TFT using a moderately aligned s‐SWCNT thin film shows drastically improved transfer characteristics. The TFT simultaneously showed a mobility of 19.6 cm2/(V · s) and an on/off ratio of 1.7 × 105, although the purity of semiconductor used in this work was not higher than 90%. Because the alignment process is very easy and effective, it is expected that moderately aligned s‐SWCNT film could be used to practical circuits made of s‐SWCNT TFTs.
Reversal Effects of Components from the Fruits of Illicium simonsii on Human Adriamycin‐resistant MCF‐7 and 5‐Fluorouracil‐resistant Bel7402 Cells
Authors: Wei Dan‐Dan , Wang Jun‐Song , Kong Ling‐Yi
Published: September 2011

Twenty‐one compounds including seven characteristic sesquiterpene lactones were isolated from Illicium simonsii and screened in vitro for their potential to restore the sensitivity of Adriamycin (ADR) resistant breast cancer cells (MCF‐7/ADR) and 5‐fluorouracil‐resistant hepatocellular carcinoma cells (Bel7402/5‐FU) to ADR and 5‐fluorouracil, respectively. These compounds were found to be non‐toxic to a panel of tumour cell lines: human breast cancer cells (MCF‐7), cervical cancer cells (HeLa), hepatic liver carcinoma cells (HepG‐2, Bel7402) and gastric carcinoma cells (BGC‐823, SGC‐7901). Five compounds showed an obvious decrease in the IC50 of doxorubicin in MCF‐7/ADR and four compounds sensitized Bel7402/5‐FU to 5‐fluorouracil at non‐toxic concentrations. The relationship between the structure of these non‐cytotoxic substances and their multidrug‐resistant (MDR) reversal abilities was investigated by principal component analysis (PCA) of the reversing fold (RF) values of these compounds and their calculated molecular descriptors of the tested substances. No correlations were found between the reversal potencies of these compounds to the two MDR cells. Compounds with lower polarity generally had stronger sensitizing ability to the P‐glycoprotein (Pgp) overexpressed MCF‐7/ADR cells. On the other hand, higher hydrophilic compounds seemed to exhibit a stronger reversal effect to the MDR‐associated protein (MRP) overexpressed Bel7402/5‐FU cell line. Our findings favoured further investigations on the active substances and the underlying mechanisms. Copyright © 2011 John Wiley & Sons, Ltd.
Antimicrobial Antioxidant Daucane Sesquiterpenes from Ferula hermonis Boiss
Authors: Ibraheim Zedan Zeid , Abdel‐Mageed Wael M. , Dai Huanqin , Guo Hui , Zhang Lixin , Jaspars Marcel
Published: September 2011

Seventeen daucane sesquiterpenoid esters, including a new one (4), were isolated from the root of Ferula hermonis Boiss. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidence and correlated with known compounds. The relative stereochemistry of the new compound was determined using 2D NOESY and the most stable and the lowest energy conformation was determined using molecular modelling. The antimicrobial activity was evaluated by determination of MIC using the broth microdilution method against six bacterial strains and one fungal strain (Pseudomonas aeruginosa PAO1, Escherichia coli, Bacillus subtilis ATCC6633, Mycobacterium bovis BCG Pasteur, Mycobacterium tuberculosis H37Rv, Staphylococcus aureus ATCC6538 and Candida albicans SC5314). There was a significant indication that compounds 15, 16, 17 demonstrated potent activity against Gram +ve (S. aureus, B. subtilis), as well as Mycobacterium strains M. bovis BCG and M. tuberculosis H37Rv. None of the isolated compounds exhibited a significant antifungal activity. In the antioxidant study using the DPPH assay method, the highest radical scavenging activity was observed for compounds 15, 16, 17. Copyright © 2011 John Wiley & Sons, Ltd.
Simulation for Transport Pallet Cost Reduction in Pet Food Manufacturing: An Empirical Case Study
Authors: Doungpattra N. , Jarupan L. , Ongkunaruk P.
Published: September 2011

This study examined different managerial scenarios for the cost reduction of transport pallets rented by a pet food manufacturer that produces pet food sold in local and international markets. A computer simulation model was developed on the basis of the empirical case to analyse the flow of pallets from the factory, the subcontractors and the distribution centre and to determine the system performance measures in terms of the average waiting times and the number of pallets in queues. The analysis showed that problems occurred when slow‐moving products occupied the rental pallets for a long time and because too much inventory was kept at the distribution centre. Two managerial scenarios were then proposed to alleviate these problems, involving pallet movement decisions by internal management. The results suggested a choice of decision supports to determine which managerial scenario was suitable for the business. The proposed implications may be beneficial to similar industries where a supply system of rental pallet service is applied. Copyright © 2011 John Wiley & Sons, Ltd.
Comparing Confidence Intervals for Multivariate Process Capability Indices
Authors: Tano Ingrid , Vännman Kerstin
Published: September 2011

Multivariate process capability indices (MPCIs) are needed for process capability analysis when the quality of a process is determined by several univariate quality characteristics that are correlated. There are several different MPCIs described in the literature, but confidence intervals have been derived for only a handful of these. In practice, the conclusion about process capability must be drawn from a random sample. Hence, confidence intervals or tests for MPCIs are important. With a case study as a start and under the assumption of multivariate normality, we review and compare four different available methods for calculating confidence intervals of MPCIs that generalize the univariate index Cp. Two of the methods are based on the ratio of a tolerance region to a process region, and two are based on the principal component analysis. For two of the methods, we derive approximate confidence intervals, which are easy to calculate and can be used for moderate sample sizes. We discuss issues that need to be solved before the studied methods can be applied more generally in practice. For instance, three of the methods have approximate confidence levels only, but no investigation has been carried out on how good these approximations are. Furthermore, we highlight the problem with the correspondence between the index value and the probability of nonconformance. We also elucidate a major drawback with the existing MPCIs on the basis of the principal component analysis. Our investigation shows the need for more research to obtain an MPCI with confidence interval such that conclusions about the process capability can be drawn at a known confidence level and that a stated value of the MPCI limits the probability of nonconformance in a known way. Copyright © 2011 John Wiley & Sons, Ltd.
Assessment of intracellular methotrexate and methotrexate‐polyglutamate metabolite concentrations in erythrocytes by ultrafast matrix‐assisted laser desorption/ionization triple quadrupole tandem mass spectrometry
Authors: Meesters Roland J. W. , den Boer Ethan , de Jonge Robert , Lindemans Jan , Luider Theo M.
Published: September 2011

A new ultrafast quantitative and high‐throughput mass spectrometric method using matrix‐assisted laser desorption/ionization triple quadrupole tandem mass spectrometry has been developed and validated for determination of intracellular erythrocyte concentrations of the antifolate drug methotrexate (MTX) and its polyglutamate metabolites. The method consists of a solid‐phase extraction of MTX and MTX‐polyglutamate metabolites from deproteinized erythrocyte lysates spiked with aminopterin as internal standard. The newly developed method was validated according to the most recent FDA guidelines on linearity, recovery, within‐run and between‐run accuracy and precision and stability of the analytes. The low limit of quantification (LLOQ) was 10 nmol/L for all analytes while the limit of detection (LOD) determined at a signal‐to‐noise (S/N) ratio = 3:1 in drug‐ free erythrocyte lysate was on average 0.3 nmol/L. After validation, the new method was used in the measurement of intracellular erythrocyte concentrations of MTX and MTX‐polyglutamate metabolites (MTXPG2 to MTXPG7) in packed human erythrocyte samples collected from patients with rheumatoid arthritis receiving low‐dose oral methotrexate therapy. Mean (SD) intracellular erythrocyte concentrations observed in patient samples were 12.8 (12.6), 12.4 (9.4), 44.4 (30.0), 33.6 (35.9) and 9.4 (8.2) nmol/L for MTX to MTXPG5, respectively, in 106 erythrocytes. The highest observed glutamylation degree of MTX was MTXPG5, the very long chain MTX‐polyglutamate metabolites MTXPG6 and MTXPG7 were not detected in the packed erythrocyte pellets collected from rheumatoid arthritis patients. Copyright © 2011 John Wiley & Sons, Ltd.
A novel online approach to the determination of isotopic ratios for organically bound chlorine, bromine and sulphur
Authors: Hitzfeld Kristina L. , Gehre Matthias , Richnow Hans‐Hermann
Published: September 2011

A novel approach for the measurement of 37Cl, 81Br and 34S in organic compounds containing chlorine, bromine, and sulphur is presented to overcome some of the major drawbacks of existing methods. Contemporary methods either require reference materials with the exact molecular compositions of the substances to be tested, or necessitate several laborious offline procedures prior to isotope analysis. In our online setup, organic compounds are separated by gas chromatography (GC) coupled to a high‐temperature reactor. Using hydrogen as a makeup gas, the reactor achieves quantitative conversion of chlorinated, brominated and sulphurated organic compounds into gaseous hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen sulphide (H2S), respectively. In this study, the GC interface was coupled to a quadrupole mass spectrometer operated in single‐ion mode. The ion traces of either H35Cl (m/z 36) and H37Cl (m/z 38), H79Br (m/z 80) and H81Br (m/z 82), or H232S (m/z 34) and H234S (m/z 36), were recorded to determine the isotopic ratios of chlorine, bromine, and sulphur isotopes. The conversion interface presented here provides a basis for a novel method for compound‐specific isotope analysis of halogenated and sulphur‐containing compounds. Rapid online measurements of organic chlorine‐, bromine‐ and sulphur‐containing mixtures will facilitate the isotopic analysis of compounds containing these elements, and broaden their usage in fields of environmental forensics employing isotopic concepts. Copyright © 2011 John Wiley & Sons, Ltd.
Metabolite identification of triptolide by data‐dependent accurate mass spectrometric analysis in combination with online hydrogen/deuterium exchange and multiple data‐mining techniques
Authors: Du Fuying , Liu Ting , Liu Tian , Wang Yongwei , Wan Yakun , Xing Jie
Published: September 2011

Triptolide (TP), the primary active component of the herbal medicine Tripterygium wilfordii Hook F, has shown promising antileukemic and anti‐inflammatory activity. The pharmacokinetic profile of TP indicates an extensive metabolic elimination in vivo; however, its metabolic data is rarely available partly because of the difficulty in identifying it due to the absence of appropriate ultraviolet chromophores in the structure and the presence of endogenous interferences in biological samples. In the present study, the biotransformation of TP was investigated by improved data‐dependent accurate mass spectrometric analysis, using an LTQ/Orbitrap hybrid mass spectrometer in conjunction with the online hydrogen (H)/deuterium (D) exchange technique for rapid structural characterization. Accurate full‐scan MS and MS/MS data were processed with multiple post‐acquisition data‐mining techniques, which were complementary and effective in detecting both common and uncommon metabolites from biological matrices. As a result, 38 phase I, 9 phase II and 8 N‐acetylcysteine (NAC) metabolites of TP were found in rat urine. Accurate MS/MS data were used to support assignments of metabolite structures, and online H/D exchange experiments provided additional evidence for exchangeable hydrogen atoms in the structure. The results showed the main phase I metabolic pathways of TP are hydroxylation, hydrolysis and desaturation, and the resulting metabolites subsequently undergo phase II processes. The presence of NAC conjugates indicated the capability of TP to form reactive intermediate species. This study also demonstrated the effectiveness of LC/HR‐MSn in combination with multiple post‐acquisition data‐mining methods and the online H/D exchange technique for the rapid identification of drug metabolites. Copyright © 2011 John Wiley & Sons, Ltd.
Magnetosomes on surface: an imaging study approach
Authors: Gojzewski Hubert , Makowski Marcin , Hashim Anezka , Kopcansky Peter , Tomori Zoltan , Timko Milan
Published: September 2011

In this study, we deposited isolated magnetosomes from magnetotactic bacteria Magnetospirillum strain AMB‐1 onto solid surfaces using spin coating (SC) and drop coating (DC) techniques. Four imaging techniques have been used to visualize the sample structure: scanning and transmission electron microscopy (SEM, TEM), atomic and magnetic force microscopy (AFM, MFM). Additionally, dynamic light scattering was applied to measure the hydrodynamic radius of agglomerated/aggregated magnetosomes in a liquid environment. This manuscript discusses observed differences between structures obtained by two deposition techniques, i.e. possible interactions and factors responsible for magnetosomes' formation, their morphology on surfaces as a result of agglomeration and aggregation phenomena. Moreover, topography and homogeneity of obtained structures as well as thickness of protein‐based membrane were also examined and described. Using high‐resolution TEM, we analyzed the size of magnetic cores, their crystal structure and quality. We found that the SC technique provides a homogenous layer of magnetosomes and hydrophilization of silicon surfaces improves the deposition of magnetosomes. However, due to strong hydrogen interaction to the hydrophilic silicone surface, the organic membrane of magnetosomes is mostly flattened. As a matter of fact, the size distributions of magnetosomes deposited by SC and DC techniques (logarithmic‐normal tendency) differ from the Feret diameter distribution (normal). Furthermore, our study confirms the good crystalline quality of magnetosomes' cores. It also shows that they are magnetic in the all their volume. SCANNING 34: 159–169, 2012. © 2011 Wiley Periodicals, Inc.
Sustainability Assessment in the Construction Sector: Rating Systems and Rated Buildings
Authors: Berardi Umberto
Published: September 2011

The increasing attention to sustainability is pushing the construction sector to build more sustainable buildings. In this scenario, several sustainable development indicators have been proposed. The worldwide diffusion of sustainability rating systems and that of their structures are considered as proxy variables for the evaluation of sustainable constructions. Available rating systems span from energy consumption evaluation systems to life cycle analysis and total quality assessment systems. In these last systems, a multi‐dimensional approach is proposed, as several building ratings are evaluated separately before being considered together. The description of assessment results from a sample of 490 buildings provides data to discuss construction characteristics that, currently, aim at being defined as sustainable. The paper shows that building energy performance is considered the most important criterion in sustainability rating systems, and the least achieved one in sustainability assessments. In contrast, other performance ratings of the building, such as water efficiency or indoor air quality, are achieved with a high rate of success in sustainability assessments. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
How potential knowledge spillovers between venture capitalists' entrepreneurial projects affect the specialization and diversification of VC funds when VC effort has value
Authors: Kang Hyoung‐Goo , Burton Richard M. , Mitchell Will
Published: September 2011

Research concerning diversification and specialization of venture capital funds typically does not consider how a VC's effort might influence performance of different portfolios. We develop a model that analyzes VC effort when there is the potential for cross‐sectional and/or serial knowledge spillover among projects. The model generates two implications concerning VC effort and performance. First, VC post‐investment effort is a nonmonotonic function of performance shocks, especially for diversified VCs. Second, greater cross‐sectional and serial knowledge spillovers improve the performance of specialization relative to diversification, and shape how the number of decision stages in a project affects portfolio choice. Copyright © 2011 Strategic Management Society.
Age matters: how demographics influence aggregate entrepreneurship
Authors: Lévesque Moren , Minniti Maria
Published: September 2011

The age distribution of a population may influence aggregate entrepreneurship and economic growth. Because of rigidities in the mobility of resources and the substitutability of employment across age groups, countries whose populations are excessively skewed toward old or young cohorts may experience low levels of entrepreneurial activity. We develop a model characterizing the conditions sufficient for aggregate entrepreneurship to decrease as a population ages or becomes younger. At a time when poorer countries confront unprecedented increases in population and developed ones see their populations aging, we provide important insights on the relationship between demographic structure, aggregate entrepreneurship, and growth. Copyright © 2011 Strategic Management Society.
XPS and SEM study of calcite bearing rock powders in the case of reactivity measurement with HCl solution
Authors: Järvinen Lauri , Leiro Jarkko Albert , Bjondahl Frej , Carletti Claudio , Eklund Olav
Published: September 2011

The dissolution of seven natural limestones and calcareous rocks in hydrochloric acid solution was examined to investigate their capability for wet flue gas desulphurisation. All samples were crushed, ground and sieved to a size‐fraction of 150–250 µm. Thereafter they were subjected to a dissolution experiment utilising stepwise titration with hydrochloric acid. The dissolution rates of three calcareous rocks were found to be controlled by reaction kinetics, while the limestones showed mass transfer control. The surface characterisation was implemented before and after dissolution experiments using X‐ray photoelectron spectroscopy and scanning electron microscopy. Additional characterisation was carried out with X‐ray diffraction, X‐ray fluorescence and polarizing microscope. Initial reactivities have been shown to decrease in the order limestone, calcareous rock with high calcium concentration, calcareous rock with low calcium concentration. Coarse grain structure is proposed to decrease the initial reactivity. Copyright © 2011 John Wiley & Sons, Ltd.
A new strategy for meta‐analysis of continuous covariates in observational studies
Authors: Sauerbrei Willi , Royston Patrick
Published: September 2011

When several studies are available, a meta‐analytic assessment of the effect of a risk or prognostic factor on an outcome is often required. We propose a new strategy, requiring individual participant data, to provide a summary estimate of the functional relationship between a continuous covariate and the outcome in a regression model, adjusting for confounding factors. Our procedure comprises three steps. First, we determine a confounder model. Ideally, the latter should include the same variables across studies, but this may be impossible. Next, we estimate the functional form for the continuous variable of interest in each study, adjusted for the confounder model. Finally, we combine the individual functions by weighted averaging to obtain a summary estimate of the function. Fractional polynomial methodology and pointwise weighted averaging of functions are the key components. In contrast to a pooled analysis, our approach can reflect more variability between functions from different studies and more flexibility with respect to confounders. We illustrate the procedure by using data from breast cancer patients in the Surveillance, Epidemiology, and End Results Program database, where we consider data from nine individual registries as separate studies. We estimate the functional forms for the number of positive lymph nodes and age. The former is an example where a strong prognostic effect has long been recognized, whereas the prognostic effect of the latter is weak or even controversial. We further discuss some general issues that are found in meta‐analyses of observational studies. Copyright © 2011 John Wiley & Sons, Ltd.
Some like it free: Innovators' Strategic use of Disclosure to slow down Competition
Authors: Pacheco‐de‐Almeida Gonçalo , Zemsky Peter B.
Published: September 2011

Why do some innovators freely reveal their intellectual property? This empirical puzzle has been a focal point of debate in the R&D literature. We show that innovators may share proprietary technology with rivals for free—even if it does not directly benefit them—to slow down competition. By disclosing IP, innovators indirectly induce rivals to wait and imitate instead of concurrently investing in innovation, which alleviates competitive pressure. In contrast with the classical strategy view, our paper also shows that imitators may not always benefit from interfirm knowledge spillovers. Specifically, imitators may want to limit the know‐how that they can freely appropriate from innovators. Otherwise, innovators have fewer incentives to quickly develop new technologies, which, ultimately, reduces the pace and profits of imitation. Copyright © 2011 John Wiley & Sons, Ltd.
Transformational leadership, integrity, and power
Authors: Harrison Laura M.
Published: September 2011

Student affairs professionals should value the ideals of transformational leadership, but they need to navigate the realities of institutional power structures, if they want to maintain their political viability and improve organizational integrity.
Two-Phase Analysis of Molecular Pathways Underlying Induced Pluripotent Stem Cell Induction
Authors: Lin Zhaoyu , Perez Philip , Lei Debin , Xu Jingyue , Gao Xiang , Bao Jianxin
Published: September 2011

Induced pluripotent stem cells (iPSCs) can be reprogrammed from adult somatic cells by transduction with Oct4, Sox2, Klf4, and c-Myc, but the molecular cascades initiated by these factors remain poorly understood. Impeding their elucidation is the stochastic nature of the iPS induction process, which results in heterogeneous cell populations. Here we have synchronized the reprogramming process by a two-phase induction: an initial stable intermediate phase following transduction with Oct4, Klf4, and c-Myc, and a final iPS phase following overexpression of Sox2. This approach has enabled us to examine temporal gene expression profiles, permitting the identification of Sox2 downstream genes critical for induction. Furthermore, we have validated the feasibility of our new approach by using it to confirm that downregulation of transforming growth factor β signaling by Sox2 proves essential to the reprogramming process. Thus, we present a novel means for dissecting the details underlying the induction of iPSCs, an approach with significant utility in this arena and the potential for wide-ranging implications in the study of other reprogramming mechanisms.
MEK-ERK Signaling Dictates DNA-Repair Gene MGMT Expression and Temozolomide Resistance of Stem-Like Glioblastoma Cells via the MDM2-p53 Axis
Authors: Sato Atsushi , Sunayama Jun , Matsuda Ken-ichiro , Seino Shizuka , Suzuki Kaori , Watanabe Eriko , Tachibana Ken , Tomiyama Arata , Kayama Takamasa , Kitanaka Chifumi
Published: September 2011

Overcoming the resistance of glioblastoma cells against temozolomide, the first-line chemotherapeutic agent of choice for newly diagnosed glioblastoma, is a major therapeutic challenge in the management of this deadly brain tumor. The gene encoding O6-methylguanine DNA methyltransferase (MGMT), which removes the methyl group attached by temozolomide, is often silenced by promoter methylation in glioblastoma but is nevertheless expressed in a significant fraction of cases and is therefore regarded as one of the most clinically relevant mechanisms of resistance against temozolomide. However, to date, signaling pathways regulating MGMT in MGMT-expressing glioblastoma cells have been poorly delineated. Here in this study, we provide lines of evidence that the mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK)–extracellular signal-regulated kinase (ERK)--murine double minute 2 (MDM2)-p53 pathway plays a critical role in the regulation of MGMT expression, using stem-like glioblastoma cells directly derived from patient tumor samples and maintained in the absence of serum, which not only possess stem-like properties but are also known to phenocopy the characteristics of the original tumors from which they are derived. We show that, in stem-like glioblastoma cells, MEK inhibition reduced MDM2 expression and that inhibition of either MEK or MDM2 resulted in p53 activation accompanied by p53-dependent downregulation of MGMT expression. MEK inhibition rendered otherwise resistant stem-like glioblastoma cells sensitive to temozolomide, and combination of MEK inhibitor and temozolomide treatments effectively deprived stem-like glioblastoma cells of their tumorigenic potential. Our findings suggest that targeting of the MEK-ERK-MDM2-p53 pathway in combination with temozolomide could be a novel and promising therapeutic strategy in the treatment of glioblastoma.
Improved multilevel bipartitioning for controlled power system islanding
Authors: Peiravi Ali , Ildarabadi Rahim
Published: September 2011

Nowadays interconnected power systems work close to their limits because of increased economic benefits. If a severe disturbance occurs in any part of the interconnected power system, it can be propagated through it. If no intelligent supervisory action is taken, a power system may be driven into an emergency state which could either cause system collapse by natural islanding or total system blackout. One possible measure to be put in effect in an emergency state is controlled power system islanding. In this paper, our previously proposed multilevel approach for controlled islanding is improved by using slow coherency grouping of generators in the aggregation phase. The approach has been applied to the IEEE 118 bus power system. The results indicate that the best partitioning of the power system is obtained with minimum generation/load imbalance in the islands, and with the coherent groups of generators maintained in each island making the restoration easy. A comparison of the computational complexities involved in the spectral, multilevel kernel k‐means and the improved multilevel approaches is made by applying these methods to the IEEE 9 bus, the IEEE 30 bus, the IEEE 39 bus, the IEEE 57 bus, the IEEE 118 bus, the IEEE 300 bus, the 2383 bus Polish and the 2746 bus Polish power systems to show the suitability of the proposed approach for controlled islanding of large‐scale power systems. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Teaching sampled‐data H∞ control theory using arm robot experiment system
Authors: She Jinhua , Xin Xin , Ohyama Yasuhiro
Published: September 2011

This paper explains how to use an arm robot experiment system to teach sampled‐data H∞ control theory. A design procedure is presented for a digital tracking control system for a continuous plant with structured uncertainties; the target is the positioning control of an arm robot. To guarantee the robust stability of the closed‐loop system and provide the desired closed‐loop performance, the design problem is first formulated as a sampled‐data H∞ control problem, and is then transformed into an equivalent discrete‐time H∞ control problem. Finally, linear matrix inequalities are used to obtain a reduced‐order output‐feedback controller and a static state‐feedback controller. In a course, the design procedure is explained and practice is provided through simulations and experiments. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.