bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of radiation wavelength on photo‐oxidation of unstabilised PVC
Authors: Martin K. G. , Tilley R. I.
Published: March 2007

Unstabilised PVC has been photo‐oxidised by exposure to xenon‐arc radiation from which shorter wavelengths had been removed by a series of filters. The wavelength sensitivity was found to correspond approximately to the complete ultraviolet region of the solar spectrum, maximum photo‐oxidation rates occurring at about 370 nm. Solar radiation data for Melbourne have been presented to show that variation in the ultra‐violet component with time of day and season is unimportant, to the extent that global radiation data may be utilised to characterise an exposure site with respect to the rate of photooxidation of PVC at that site.
Comparison of phonic analysis and whole word‐reading on first graders' cumulative words read and cumulative reading rate: An extension in examining instructional effectiveness and efficiency
Authors: Schmidgall Melissa , Joseph Laurice M.
Published: March 2007

This study compared the instructional effectiveness and efficiency of three word‐reading interventions on cumulative number of words read accurately and cumulative learning rate. Participants were six first graders who needed intensive intervention services. Alternating treatment designs were used to compare the effects of interspersal drill, a phonic analysis method consisting of word boxes (WB), and traditional drill and practice procedure on word‐reading performance. The current study extended this line of inquiry by including a phonic analysis condition and a measure of generalization. Results revealed that four students' cumulative word‐reading performances were greater under the phonic analysis condition. However, all students' cumulative rate of reading words was greater under the traditional drill and practice condition. As a group, there were no significant differences across conditions on maintaining and generalizing words. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 319–332, 2007.
Tryptic digestion of ubiquitin standards reveals an improved strategy for identifying ubiquitinated proteins by mass spectrometry
Authors: Denis Nicholas J. , Vasilescu Julian , Lambert Jean‐Philippe , Smith Jeffrey C. , Figeys Daniel
Published: March 2007

Ubiquitination plays an essential role in maintaining cellular homeostasis by regulating a multitude of essential processes. The ability to identify ubiquitinated proteins by MS currently relies on a strategy in which ubiquitinated peptides are identified by a 114.1 Da diglycine (GG) tag on lysine residues, which is derived from the C‐terminus of ubiquitin, following trypsin digestion. In the following study, we report a more comprehensive approach for mapping ubiquitination sites by trypsin digestion and MS/MS analysis. We demonstrate that ubiquitination sites can be identified by signature peptides containing a GG‐tag (114.1 Da) and an LRGG‐tag (383.2 Da) on internal lysine residues as well as a GG‐tag found on the C‐terminus of ubiquitinated peptides. Application of this MS‐based approach enabled the identification of 96 ubiquitination sites from proteins purified from human MCF‐7 breast cancer cells, representing a 2.4‐fold increase in the number of ubiquitination sites that could be identified over standard methods. Our improved MS‐based strategy will aid future studies which aim to identify and/or characterize ubiquitinated proteins in human cells.
Cellular processes underlying maturation of P19 neurons: Changes in protein folding regimen and cytoskeleton organization
Authors: Inberg Alex , Bogoch Yoel , Bledi Yaniv , Linial Michal
Published: March 2007

Embryonal carcinoma P19 cells provide an ideal model to study molecular programs along differentiation. Upon induction by retinoic acid (RA), the cells undergo a program of differentiation that generates functioning neurons within 60 h. RA induced cells that were plated as sparse (1000 cells/mm2) or dense (4000 cells/mm2) cultures showed a marked difference in the culture morphology with the dense cultures exhibiting rapid maturation and accelerated neurite outgrowth. The protein expression levels of the sparse and dense cultures were compared 48 h following RA. Cell extracts were separated by 1‐DE and 2‐DE and differential expression (>four‐fold) proteins were identified by MS. Here, we focus on 20 proteins associated with cytoskeletal regulation and stress‐dependent protein refolding. The first group includes drebrin, cofilin, α‐internexin, vimentin, and nestin. Among the proteins in the second group are subunits of the TCP‐1, and several chaperones of the Hsp70 and Hsp90 families. We show that coordinated remodeling of the cytoskeleton and modulations in chaperone activity underlie the change in neurite extension rate. Furthermore, a proteomics‐based analysis applied on P19 neurons demonstrated pathways underlying neuronal outgrowth, suggesting that a malfunction of such pathways leads to neuropathological conditions.
Mathematical modeling of crystallization analysis fractionation of ethylene/1‐hexene copolymers
Authors: Anantawaraskul Siripon , Jirachaithorn Preechathorn , Soares João B. P. , Limtrakul Jumras
Published: March 2007

Crystallization analysis fractionation (Crystaf) is a polymer characterization technique for estimating the chemical composition distributions of semicrystalline copolymers. Although Crystaf has been widely used during the recent years, it is still a relatively new polymer characterization technique. More quantitative understanding of its fractionation mechanism is essential for further developments. In this work, three ethylene/1‐hexene copolymers with different 1‐hexene fractions, but similar number‐average molecular weights, were analyzed by Crystaf at several cooling rates. A mathematical model was proposed to describe the effect of comonomer fraction and cooling rate on Crystaf fractionation from a fundamental point of view. The model describes the experimental Crystaf profiles of ethylene/1‐hexene copolymers with different 1‐hexene fractions measured at distinct cooling rates very well. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1010–1017, 2007
The water mediated ring closing in the formose reaction
Authors: Jalbout Abraham F. , Pavanello Michele , Adamowicz Ludwik
Published: March 2007

In this work, we investigate the ring closing mechanisms leading to the formation of formose by high‐level ab initio theoretical calculations. We suggest that a water‐mediated ring closing mechanism (through the use of H3O+) is energetically the most favorable pathway for this process. Solvent effects have also been computed and the results further confirm our assertion of the catalytic effect of water in the ring‐closing mechanism of the formose reaction. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Electron propagator studies of vertical electron detachment energies and isomerism in purinic deoxyribonucleotides
Authors: Zakjevskii V. V. , Dolgounitcheva O. , Zakrzewski V. G. , Ortiz J. V.
Published: March 2007

Electron propagator calculations in the Partial Third Order Approximation were performed on major and minor conformational isomers of 2′‐deoxyriboadenosine 5′‐monophosphate (dAMP−) and 2′‐deoxyriboguanosine 5′‐monophosphate (dGMP−). Resulting vertical electron detachment energies (VEDEs) correspond extremely well with the experimental values available from the literature. The first VEDE in dGMP− is caused by electron detachment from the guanine moiety and is well separated from the rest of the spectrum. The offset of the ionization band in the case of dAMP− is caused by two, almost degenerate detachments, one from the phosphate group and another from the adenine π1 molecular orbital. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
ONIOM quantum chemistry study of cyclic nucleotide recognition in phosphodiesterase 5
Authors: O'Brien Kerrie A. , Salter E. A. , Wierzbicki A.
Published: March 2007

Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that contribute to the regulation of cyclic nucleotides in the cell by catalyzing the hydrolysis reaction of the O3′‐phosphorous bond, yielding the noncyclic nucleotide as the product. The principal substrates are cyclic 3′,5′‐adenosine and ‐guanosine monophosphate (cAMP and cGMP). PDE5, an important target of drug inhibition, is known to be highly selective for hydrolysis of cGMP. We use all‐quantum hybrid calculations to accurately describe the binding interactions between PDE5 and cAMP/cGMP for the first time. The main reasons for cGMP preference in PDE5 are found to be to the fixed orientation of a conserved glutamine residue (Gln 817) together with the fixed orientation of a nonconserved glutamine residue (Gln 775). We report ONIOM(B3LYP/6‐31g(d):PM3MM) binding energies, which reflect favorable guanine alignment with Gln 817 and steric crowding of adenine by Gln 775. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Morse potential eigen‐energies through the asymptotic iteration method
Authors: Al‐Dossary O. M.
Published: March 2007

The eigen‐energies of the rotating Morse potential based on the original Pekeris approximation are obtained by means of the asymptotic iteration method. This approach is applied to several diatomic molecules, and it is shown that the numerical results for the eigen‐energies are all in excellent agreement with the ones obtained before. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Multistage electrospray ionization mass spectrometric analyses of sulfur‐containing iridoid glucosides in Paederia scandens
Authors: Zhou Yan , Zou Xu , Liu Xin , Peng Shu‐lin , Ding Li‐sheng
Published: March 2007

Paederia scandens is a traditional Chinese herbal medicine that possesses important bioactive sulfur‐containing iridoid glucosides. This study reports the investigation of the fragmentation behavior of four sulfur‐containing iridoid glucosides isolated from P. scandens by ion trap electrospray ionization tandem mass spectrometry (ESI‐MSn). Both multistage electrospray ionization (ESI‐MSn) experiments in an ion trap instrument and high‐resolution and accurate mass measurement in an ESI‐Q‐TOF mass spectrometer in positive mode were used to elucidate the main fragmentation pathways of these compounds. These experiments yielded essentially the same product ions in both ion trap and Q‐TOF instruments, and their fragmentation patterns were found useful for their characterization, which were applied to elucidate a trace compound in the extracts of P. scandens by on‐line LC/ESI‐MSn. Major and diagnostic product ions have been identified and their origins are proposed. Copyright © 2007 John Wiley & Sons, Ltd.
An online method combining a thermal conversion elemental analyzer with isotope ratio mass spectrometry for the determination of hydrogen isotope composition and water concentration in geological samples
Authors: Gong Bing , Zheng Yong‐Fei , Chen Ren‐Xu
Published: March 2007

An online continuous‐flow method, combining a thermal conversion elemental analyzer (TC/EA) with isotope ratio mass spectrometry (MS), is evaluated for the determination of both the hydrogen isotope composition and the water concentration of hydrous and nominally anhydrous minerals. The technique involves reduction of hydrous minerals or nominally anhydrous minerals by reaction with glassy carbon at 1450°C in a helium stream. The product gases, H2 and CO, are separated on a gas chromatographic column prior to analysis in the mass spectrometer. Calibration curves for the H concentration analysis were generated from a standard of benzoic acid (C7H6O2) that has an H concentration of 5.0 wt%; the analytical uncertainties were better than ±0.05% in our runs. Two standards of material with given δD values, polyethylene IAEA‐CH‐7 and biotite NBS‐30, were tested for the purpose of calibrating a natural garnet 04BXL02 representing nominally anhydrous minerals. Preheating at 90°C for 12 h was found to be suitable for removing adsorption water on the sample surface. This results in constant δD values and total H2O contents for the garnet, with weighted means of −94 ± 1‰ and 522 ± 11 ppm (wt), respectively. The TC/EA‐MS technique allows routine analysis of sample sizes as small as 0.01 µL H2O. For natural minerals, absolute reproducibilities for δD values are ±0.5‰ to ±2‰ (1σ) and relative uncertainties for total H2O concentrations are at levels of ±1% to ±3% (1σ). Therefore, this online method can be used for the quantitative determination of H isotope composition and H2O concentration of either hydrous or anhydrous minerals. Copyright © 2007 John Wiley & Sons, Ltd.
2‐Substituted benzofuran fragment ion formation in the electron ionization mass spectra of 6‐alkyl‐ and 6‐aryldibenzo(d,f)(1,3)dioxepine derivatives. 1. Spirocyclization of the molecular ions in the gas phase
Authors: Begala Michela , Tocco Graziella , Meli Gabriele , Podda Gianni , Urru Silvana A. M.
Published: March 2007

The formation of 2‐substituted benzo[b]furan ions in the electron ionization (EI) mass spectra of a series of 6‐alkyl‐ and 6‐aryldibenzo(d,f)(1,3)dioxepines has been studied by means of exact mass measurements and multiple‐stage mass spectrometry conditions using an ion trap mass spectrometer. The proposed mechanism of formation of benzo[b]furan ions requires the formation of a spirocyclic cyclohexadienone system, which undergoes elimination of a cyclopentadienone molecule. A parallel with the chemical conversion of arylmethyl‐substituted dibenzo(d,f)(1,3)dioxepines into an analogous spirocyclic system was also underlined. Copyright © 2007 John Wiley & Sons, Ltd.
Iterative interference cancellation and channel estimation in multibeam satellite systems
Authors: Millerioux J. P. , Boucheret M. L. , Bazile C. , Ducasse A.
Published: March 2007

This paper deals with the use of non‐linear multiuser detection techniques to mitigate co‐channel interference on the reverse link of multibeam satellite systems. These techniques allow more capacity efficient frequency reuse strategies than classical ones, as they make possible to cope with lower C/I. The considered system takes as a starting point the DVB‐RCS standard, with the use of convolutional coding, and the use of the Ka‐band.

We propose different iterative interference cancellation schemes, which operate at the beamformer outputs, and which use information from decoders. The proposed receivers assume an initial single‐user synchronization step: frame synchronization and timing recovery, and then perform channel estimation: beamformer coefficients; signal carrier phases and signal amplitudes.

In a first step, these receivers are evaluated by simulation in terms of bit error rate and of channel estimation error on two interference configurations. For one of these receivers, sensitivity to imperfect timing recovery and to low‐frequency offsets from user terminals is evaluated.

In a second step, since the receiver performances highly depend on the interference configuration, we propose an approach to evaluate performances on a multibeam coverage (by taking into account the variability of interference configurations on the coverage). This method is used to compare different receivers on an example based on a coverage designed on a digital focal array feed reflector antenna. Copyright © 2007 John Wiley & Sons, Ltd.
CEO tenure and organizational performance: an intervening model
Authors: Simsek Zeki
Published: March 2007

While CEO job tenure is seen as influencing firm performance, the intervening mechanisms that govern this influence have remained largely unexplored. Given that individuals in the firm most closely influenced by the CEO are members of the top management team (TMT), we focus on the CEO‐TMT interface as one important intervening mechanism. Specifically, our tested model suggests that CEO tenure indirectly influences performance through its direct influences on TMT risk‐taking propensity and the firm's pursuit of entrepreneurial initiatives. Results from structural equation modeling are consistent with this model and support its associated hypotheses. In the discussion, we trace the implications of our study for research and practice. Copyright © 2007 John Wiley & Sons, Ltd.
The role of managers' political networking and functional experience in new venture performance: Evidence from China's transition economy
Authors: Li Haiyang , Zhang Yan
Published: March 2007

Drawing upon the resource‐based view and transaction cost economics, this study aims to examine how various types of managerial resources (i.e., political networking and functional experience) can be beneficial to new ventures in a transition economy. Using survey data from a sample of new ventures in China's high‐technology industries, we demonstrate that managers' political networking and functional experience are positively related to new venture performance. We also find that the positive relationship between functional experience and new venture performance is moderated by the type of ownership of the ventures and the level of dysfunctional competition in their environments. Theoretical and managerial implications are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Allocation of inventive effort in complex product systems
Authors: Ethiraj Sendil K.
Published: March 2007

This paper examines the allocation of inventive effort in complex product systems. I argue that complex product systems, e.g., personal computers (PCs), are distinguished by functional interaction among several components, each guided by a relatively autonomous bundle of technical and economic characteristics. I try to explore whether the dynamics of such interactions between components of complex product systems can help us understand changes in the relative allocation of inventive effort. I advance and empirically test three hypotheses: (1) emergence of component constraints (bottlenecks) in product systems will trigger research and development (R&D) investment to resolve the constraints; (2) slack component firms have a strong incentive to invest in resolving component constraints; and (3) the incentive of slack component firms to invest in resolving component constraints is increasing in their prior sunk R&D investments in slack components. In sum, I argue that interactions between components in a product system conditions the R&D incentives of firms and also that the incentives are increasing in their prior investments or capabilities. Using product reviews from technical journals, I trace the constraint components in the PC from 1981 to 1998 and attempt to predict shifts in the allocation of inventive effort in the subsequent period. The empirical results strongly support all three hypotheses. This study highlights the paradoxical effect of modularity in complex product systems. Modular design architectures, while contributing to accelerating the pace of technical change, also tend to limit the economic benefits of firms' component R&D efforts, especially when different components technologies are progressing at different rates. This often creates an impetus to enlarge the scope of firm R&D activities beyond the component product markets that firms operate in. Other implications for R&D decision making are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
On the position of the Seventy Disciples of Confucius in the prose history of the pre-Qin period
Authors: Tongsheng CHEN
Published: March 2007

In this paper, such works as Lunyu 论语 (The Analects of Confucius), Dadai liji 大戴礼记 (Book of Rites with Commentaries of Dai De), Xiaodai liji 小戴礼记 (Book of Rites with Commentaries of Dai Sheng), Xiaojing 孝经 (Classic of Filial Piety), Yili 仪礼 (Etiquette and Ceremonial) and other Confucian documents found in the Guodian bamboo strips and the Shanghai Museum bamboo strips are studied as “prose by the Seventy Disciples of Confucius”. In addition, the “Seventy Disciples” are divided into the “Early Generation” and the “Late Generation”, and according to their different writing styles they are also divided into “the Transmitters” and “the Creators.” The “prose by the Seventy Disciples of Confucius” is the link connecting the official historians’ narrative prose with the pre-Qin philosophers’ argumentative prose.
Metabolic Syndrome: Effects of n‐3 PUFAs on a Model of Dyslipidemia, Insulin Resistance and Adiposity
Authors: Lombardo Yolanda B. , Hein Gustavo , Chicco Adriana
Published: March 2007

Both genetic and environmental factors (e.g. nutrition, life style) contribute to the development of the plurimetabolic syndrome, which has a high prevalence in the world population. Dietary n‐3 PUFAs specially those from marine oil (EPA and DHA) appear to play an important role against the adverse effects of this syndrome. The present work examined the effectiveness of fish oil (FO) in reversing or improving the dyslipidemia, insulin resistance and adiposity induced in rats by long‐term feeding a sucrose‐rich diet (SRD). We studied several metabolic and molecular mechanisms involved in both lipid and glucose metabolisms in different tissues (liver, skeletal muscle, fat pad) as well as insulin secretion patterns from perifused islets under the stimulation of different secretagogues. Dietary FO reverses dyslipidemia and improves insulin action and adiposity in the SRD fed rats. FO reduces adipocytes cell size and thus, the smaller adipocytes are more insulin sensitive and the release of fatty acids decreases. In muscle, FO normalizes both the oxidative and non‐oxidative glucose pathways. Moreover, FO modifies the fatty acid composition of membrane phospholipids. In isolated β cells, lipid contents and glucose oxidation return to normal. All these effects could contribute to the normalization of glucose‐stimulated insulin secretion and muscle insulin insensitivity.
A novel prokaryotic trans‐2‐enoyl‐CoA reductase from the spirochete Treponema denticola
Authors: Tucci Sara , Martin William
Published: March 2007

An NADH‐dependent trans‐2‐enoyl‐CoA reductase (EC1.1.1.36) from the Gram negative spirochete Treponema denticola was identified, expressed and biochemically characterized. The recombinant protein is a monomeric enzyme with a molecular mass of 44 kDa with a specific activity of 43 ± 4.8 U/mg (μmol mg−1
min−1) and K
m value of 2.7 μM for crotonoyl‐CoA. This NADH‐dependent trans‐2‐enoyl‐CoA reductase represents the first enzymatically characterized member of a prokaryotic protein family involved in a fatty acid synthesis pathway that is distinct from the familiar fatty acid synthase system.
Improving the prediction of human microRNA target genes by using ensemble algorithm
Authors: Yan Xingqi , Chao Tengfei , Tu Kang , Zhang Yu , Xie Lu , Gong Yanhua , Yuan Jiangang , Qiang Boqin , Peng Xiaozhong
Published: March 2007

MicroRNAs are a class of small endogenous noncoding RNAs which play important regulatory roles mainly by post‐transcriptional depression. Finding miRNA target genes will help a lot to understand their biological functions. We developed an ensemble machine learning algorithm which helps to improve the prediction of miRNA targets. The performance was evaluated in the training set and in FMRP associated mRNAs. Moreover, using human mir‐9 as a test case, our classification was validated in 9 of 15 transcripts tested. Finally, we applied our algorithm on the whole prediction data set provided by miRanda website. The results are available at http://www.biosino.org/~kanghu/mRTP/mRTP.html.
RNA recognition mechanism of eukaryote tRNA (m7G46) methyltransferase (Trm8–Trm82 complex)
Authors: Matsumoto Keisuke , Toyooka Takashi , Tomikawa Chie , Ochi Anna , Takano Yoshitaka , Takayanagi Naoyuki , Endo Yaeta , Hori Hiroyuki
Published: March 2007

Yeast tRNA (m7G46) methyltransferase contains two protein subunits (Trm8 and Trm82). To address the RNA recognition mechanism of the Trm8–Trm82 complex, we investigated methyl acceptance activities of eight truncated yeast tRNAPhe transcripts. Both the D‐stem and T‐stem structures were required for efficient methyl‐transfer. To clarify the role of the D‐stem structure, we tested four mutant transcripts, in which tertiary base pairs were disrupted. The tertiary base pairs were important but not essential for the methyl‐transfer to yeast tRNAPhe transcript, suggesting that these base pairs support the induced fit of the G46 base into the catalytic pocket.
Nutritional genomics: food industry applications from farm to fork
Authors: Brown Louise , van der Ouderaa Frans
Published: March 2007

Nutritional genomics is a new and promising science area which can broadly be defined as the application of high throughput genomics (transcriptomics, proteomics, metabolomics/metabonomics) and functional genomic technologies to the study of nutritional sciences and food technology. First utilised in the food industry by plant biotechnologists to manipulate plant biosynthetic pathways, the use of genomic technologies has now spread within the agriculture sector, unleashing a host of new applications (e.g. approaches for producing novel, non-transgenic plant varietals; identification of genetic markers to guide plant and animal breeding programmes; exploration of diet–gene interactions for enhancing product quality and plant/animal health). Beyond agriculture, genomic technologies are also contributing to the improvement of food processing, food safety and quality assurance as well as the development of functional food products and the evolution of new health management concepts such as ‘personalised nutrition’, an emerging paradigm in which the diet of an individual is customised, based on their own genomic information, to optimise health and prevent disease. In this review the relevance of nutritional genomics to the food industry will be considered and examples given on how this science area is starting to be leveraged for economic benefits and to improve human nutrition and health.
Canadian Mining Companies and Corporate Social Responsibility: Weighing the Impact of Global Norms
Authors: Dashwood Hevina S.
Published: March 2007

Abstract.This study analyzes the factors that led two Canadian mining companies, Noranda and Placer Dome, to adopt polices on corporate social responsibility (CSR). Although much has been written on CSR in the business and organization fields, there has been little scholarly treatment of the topic from a social sciences perspective. A common assumption is that companies are merelyreactingto societal pressures from transnational non-governmental organizations. This study challenges that assumption, by weighing the impact of emerging global norms of CSR against influences internal to the companies themselves, and domestic influences operating in Canada. The research findings point to the decisive influence of internal company dynamics and the experience of operating mines in Canada. While emerging global CSR norms are important, their role is more complex than is often assumed, as mining companies have beenproactivein their efforts to shape those norms.

Résumé.Cette étude analyse les facteurs qui ont amené deux sociétés minières canadiennes, Noranda et Placer Dome, à adopter des politiques concernant la responsabilité sociale de l'entreprise (RSE). La RSE a fait couler beaucoup d'encre dans le domaine des affaires et de l'organisation, mais peu de chercheurs s'y sont intéressés dans la perspective des sciences sociales. On part très souvent de l'hypothèse que les sociétés se contentent deréagiraux pressions sociales exercées par les organisations non-gouvernementales transnationales. Cette étude remet cette hypothèse en question en comparant l'impact des normes globales émergentes de la RSE aux influences internes aux sociétés elles-mêmes, et aux influences domestiques qui s'exercent au Canada. Les résultats révèlent l'influence décisive des dynamiques internes des sociétés et celle de l'expérience dérivée de l'exploitation des mines au Canada. Les normes globales émergentes en matière de RSE sont certes importantes, mais leur rôle est plus complexe qu'on ne l'admet souvent car les sociétés minières ont joué un rôle très actif dans leur élaboration.
Numbers and Newness: The Descriptive and Substantive Representation of Women
Authors: Beckwith Karen
Published: March 2007

Abstract.The concept of “critical mass,” drawn from physics and organizational behaviour literatures, has been employed by women and politics scholars as a potential theoretical underpinning for explaining and predicting women's substantive representation in national legislatures. This article examines two number-based theories of women's substantive representation—critical mass theory and sex-ratio proportional theory—and assesses their theoretical utility. It then proposes the alternative of focusing on the impact of newness, or a substantial increase in the number and proportion of women elected for the first time, on women's substantive representation. The article identifies research design issues and discusses the intersection of “newness” and “numbers” for evaluating women's substantive representation in parliaments. Offering a range of hypotheses for testing, it concludes by identifying an irony for critical mass research and by underscoring the necessarily gendered nature of the newness-numbers intersection.

Résumé.Le concept de “ masse critique ” issu de la physique et de la recherche en comportement organisationnel a été utilisé par les spécialistes du rapport femmes et politique comme modèle théorique possible pour expliquer et prédire la représentation substantive des femmes dans les législatures nationales. Cet article se propose d'examiner deux théories quantitatives de la représentation substantive des femmes et d'évaluer leur utilité théorique : 1. la théorie de la masse critique et 2. la théorie proportionnelle du sex ratio, et propose un autre modèle basé sur l'incidence de la nouveauté, ou une augmentation sensible dans le nombre et les proportions de femmes élues pour la première fois, sur la représentation substantive des femmes. L'article se penche sur les questions de méthodologie de la recherche et analyse l'intérêt du point d'intersection “ nouveauté ” et “ chiffres ” pour l'évaluation de la représentation substantive des femmes dans les parlements. À partir d'un choix d'hypothèses permettant d'évaluer ces modèles, l'article conclut en identifiant une ironie en ce qui concerne la recherche de masse critique et en soulignant le fait que la nature du point d'intersection nouveauté/chiffres est forcément marquée par le genre.
Droits démocratiques et identités,
Authors: LeBlanc Isabelle
Published: March 2007

Droits démocratiques et identités,, sous la
direction de Bjarne Melkevik et Luc Vigneault., Collection Dikè,
Les Presses de l'Université Laval, 2006. 148 p.

Ce ouvrage collectif regroupe les contributions de huit auteures et
auteurs au débat politique, social et juridique sur les
implications de la mondialisation, pour la société civile
d'une part et pour l'institution juridique d'autre part.
C'est dans le contexte contemporain de la mondialisation que ce livre
traite d'abord des droits démocratiques, puis du lien qui
existe entre l'identité et le droit. Lecteurs et lectrices
sont ainsi plongés, grâce à diverses perspectives et
approches, dans un profond questionnement de la compatibilité entre
le citoyen et le droit et dans une réflexion sur le décalage
qui peut exister entre l'ordre économique mondial, la
démocratie, les droits humains, la possibilité ou non de
l'universalité, les différences identitaires et le sens
même du politique.
The Success of Open Source
Authors: Zschoch Mark
Published: March 2007

The Success of Open Source, Steven Weber, Cambridge MA:
Harvard University Press, 2004, pp. viii, 312.

The phenomenon of open source software produced by distributed
networks of largely volunteer computer programmers has been studied by
legal scholars, economists, sociologists, anthropologists and computer
scientists but has to date not drawn significant attention from political
scientists. Steven Weber's book undertakes a political economic
analysis of this topic. Weber attempts to address the questions of what
incentives establish and sustain co-operation in the absence of direct
monetary rewards and how a system of governance develops despite the lack
of conventional exclusionary property rights.
Nature and History in American Political Development: A Debate
Authors: Breckenridge George
Published: March 2007

Nature and History in American Political Development: A
Debate, James W. Ceaser; with responses from Jack N. Rakove, Nancy L.
Rosenblum, Rogers M. Smith, Cambridge MA: Harvard University Press, 2006,
pp. viii, 197.

James Ceaser gave the first Tocqueville Memorial Lecture on American
Politics sponsored by the Center for American Political Studies at Harvard
in 2004. This volume contains an expanded version of his lecture, the
three responses by, respectively, a historian, a political theorist, and a
political scientist, and Ceaser's rejoinder or, in the case of
Rosenblum, rebuttal to each. There are two things going on in this volume:
a scholarly debate on how to approach the elusive question of the role of
ideas in politics and a rather acrimonious argument over Ceaser's
motivation.
Fidel Castro and “China's Lesson for Cuba”: A Chinese Perspective
Authors: Cheng Yinghong
Published: March 2007

This article examines the global impact of China's post-Mao transformation as reflected in Sino-Cuban relations. China and Cuba resumed their comradeship after Castro endorsed China's crackdown of the 1989 pro-democracy movement, and since then Beijing has promoted its approach towards legitimizing the one-party regime through engaging in economic reforms and opening to the world to Havana. “China's lesson for Cuba” has been discussed by many Cubanists worldwide. However, the Chinese approach has posed a dilemma to Fidel Castro: he admires China's power but has doubts about the future of socialism in China. The article argues that Castro has so far adopted his old strategy for dealing with Soviet influence in the 1960s in his engagement with China: praising his political ally's power as the evidence of socialism's vitality for his domestic consumption, while significantly limiting the application of China's economic policies. But his more pragmatic successors, Raul Castro in particular, may adopt the Chinese approach.
Contemporary Re-emergence of the Qipao: Political Nationalism, Cultural Production and Popular Consumption of a Traditional Chinese Dress
Authors: Chew Matthew
Published: March 2007

The qipao ceased to be worn for everyday occasions afer the 1950s in the PRC and the late 1960s in Hong Kong, Taiwan and Singapore. But it has powerfully re-emerged in the last few years. This is puzzling considering the swiftness and broad scale of the re-emergence, and the qipao's recent history of being marginalized. Are the political and cultural elites responsible and what motivated them? Besides political and cultural nationalism, are there other reasons that have led a large number of people to resume wearing the qipao? This study finds that the state did not play a significant role in the qipao's re-emergence, that cultural producers and celebrities contributed much to it, and that the symbolic meanings of the modern historical qipao have been repackaged and now cater to a variety of consumers for very different reasons.
The Rise and Fall of Leninist Control in Taiwan's Industry
Authors: Ho Ming-sho
Published: March 2007

As an industrial control strategy, Leninism imposed extensive state-party apparatuses in the workplace. After its defeat in China, the émigré Kuomintang instituted party-state infrastructure in the vast public sector inherited from Japanese colonialism to consolidate its grasp on Taiwan. This article traces the rise and fall of Leninist control in Taiwan's state-owned enterprises. Taiwan's Leninist penetration was deployed after the suppression of the 1947 uprising, and hence failed to overcome the pre-existing ethnic divide between Taiwanese and mainlanders. Further, since the 1960s, widespread moonlinghting has enabled Taiwanese workers to be more psychologically and economically detached from the clientelist network of redistribution. As the political environment turned favourable in the late 1980s, a strong current of workers's movements surged and succeeded in dismantling party-state control in nationalized industry. Taiwan's case reveals the importance of societal embeddedness as a variable that explains the trajectory of Leninist control.
PRECLASSIC MAYA OCCUPATION OF THE ITZAN ESCARPMENT, LOWER RÍO DE LA PASIÓN, PETÉN, GUATEMALA
Authors: Johnston Kevin J.
Published: March 2007

Maya elites and commoners intensively occupied the Itzan escarpment, located in the lower Río de la Pasión drainage system of Petén, Guatemala, during the Preclassic and Protoclassic periods. Itzan was colonized during the Xe phase of the Middle Preclassic period, and its occupation intensified during the late Middle and Late Preclassic periods, when elite residential and ceremonial facilities were erected. During the Late Preclassic and Protoclassic periods, the escarpment was dominated by Chaak Ak'al, a large site distinguished by massive pyramids and lengthy wall-like constructions, which undoubtedly served as a polity capital. Subsequent to the Protoclassic period, the locus of activity atop the escarpment shifted back to Itzan, which served as a polity capital through the Late Classic period. From data collected at Itzan, Chaak Ak'al, and other sites of the lower Río de la Pasión drainage system, a picture of regional Preclassic Maya political geography is emerging.
A PERSONAL HOMENAJE TO PHIL WEIGAND
Authors: Pickering Robert B. , Beekman Christopher S.
Published: March 2007

Back in the late 1960s and early 1970s, Southern Illinois University
at Carbondale was “the” place to be for anyone interested in
North or West Mexican studies. J. Charles Kelley, Carroll
“Cal” Riley, Campbell Pennington, and Basil Hedrick
constituted the cadre of scholars who specialized in the region but also
served as mentors and models for what anthropological archaeology could
be, even in the pre-Binfordian days. Walter Taylor also was there as an
icon of theoretical archaeology. All of these scholars not only believed
but also demonstrated that the subdisciplines of anthropology were
intimately connected. To pursue one perspective to the exclusion of the
other subdisciplines was deemed artificially limiting. Into this milieu
came Lewis and Sally Binford during the summers of 1962 and 1963, working
on the Carlyle Reservoir project in southern Illinois, which included
excavations at Hatchery West, Toothsome, and Galley Pond. At about the
same time, they began publishing archaeological theory and methodology
that revolutionized the discipline. Only Lew and Sally can say how their
time in Carbondale shaped their perspectives but, for me, I'd like to
think that the Carbondale experience positively influenced their
interdisciplinary work. I well remember discussions with Kelley regarding
the new archaeology that he learned under Clyde Kluckhohn at Harvard
before and during WWII, in comparison to the other “new”
archaeology championed by the Binfords. Riley, Pennington, and Hedrick
provided students with opportunities to integrate the archaeological
perspective with the ethnographic and historical in material culture
studies. The graduate students, including Weigand, Joe Mountjoy, and
others, kept the discussion alive.
The Legal Status of Tenants and Sharecroppers in Seventeenth- and Eighteenth-Century France and Ottoman Syria
Authors: JOSEPH SABRINA
Published: March 2007

By the middle of the sixteenth century, the role of the tenant farmer and sharecropper in both Syria and France witnessed important transformations which lent increasing relevance to the social and legal status enjoyed by these cultivators. In various regions of France after the sixteenth century, a rising class of bourgeois landholders increasingly appropriated agricultural lands from both peasant proprietors and nobles, leading to the spread of both sharecropping and leasing contracts. In Ottoman Syria, the appropriation of peasant lands and proliferation of tenancy arrangements was linked to an expanding state which sought to consolidate power and ensure the consistent flow of revenue. Thus, this paper will address how the socio-legal discourse on tenants and sharecroppers differed in a context where arable lands were appropriated by private rather than public forces. Issues that are examined include: perceptions of agricultural innovation; possession rights; and payment of rent and other dues.

While Islamic legal scholars articulated a discourse which sought to incorporate tenants and sharecroppers, French legal and social thinkers of the day championed the rights of the landlord above all else. Unlike their Syrian counterparts, French thinkers linked agricultural development and efficient production to private ownership of land. In Syria, on the other hand, jurists advocated a land tenure system in which the possession rights of cultivators were supported while landlord interests were not jeopardised. Thus, agricultural development in the Syrian case was articulated within a framework which conceded multiple layers of ownership. These ideas would have an important impact on nineteenth-century developments in both regions.
Commerce and Community in the Countryside: The Social Ambiguity of Market-Oriented Farming in Pre-Industrial Northern South-West Germany (c.1770–1860)
Authors: GRÜNE NIELS
Published: March 2007

In the mainstream literature on the socio-political history of the German countryside in the late eighteenth and nineteenth centuries, the south-west areas of partible inheritance are often stereotypically contrasted with the regions of impartible inheritance in the north and north-west. While the latter were dominated by the antagonism between large peasants and tenant-labourers, it is claimed, the far more homogenous village societies in the south-west were primarily marked by conflicts with external powers such as the state and nobility. This dichotomic model, however, fails to account for major differences in political culture within the south-west, which in many cases cannot simply be explained with reference to divergent social structures, such as property distribution, either. In the following article it is argued that specific forms of agricultural market-integration and their effects on rural status groups had a crucial impact on collective solidarities and local cohesion. This hypothesis is empirically tested by comparatively analysing demographic development, access to land and, most extensively, modes of commercialisation in four exemplary regions on the northern upper Rhine. In the last section, these observations are tentatively related to distinctive forms of political mobilisation.
Dormancy-break and germination in seeds ofPrunus campanulata(Rosaceae): role of covering layers and changes in concentration of abscisic acid and gibberellins
Authors: Chen Shun-Ying , Chien Ching-Te , Chung Jeng-Der , Yang Yuh-Shyong , Kuo Shing-Rong
Published: March 2007

Intact seeds (seed+endocarp) from freshly harvested fruits ofPrunus campanulatawere dormant, and required 4–6 weeks of warm followed by 8 weeks of cold stratification for maximum germination percentage. Removing both endocarp and seed coat, however, promoted germination in a high percentage of non-stratified seeds. Treatment of intact, non-stratified seeds with gibberellic acid (GA3) was only partially effective in breaking dormancy. However, GA3promoted germination of non-stratified seeds in which the endocarp (but not the seed coat) had been removed. The order of abscisic acid (ABA) concentration in fresh seeds was endocarp > seed coat > embryo, and its concentration in endocarp plus seed coat was about 6.2-fold higher than that in the embryo. Total ABA contents of seeds subjected to warm and/or cold moist stratification were reduced 6- to 12-fold. A higher concentration of GA4was detected in embryos of non-dormant than in those of dormant seeds. Fluridone, a carotenoid biosynthesis inhibitor, was efficient in breaking dormancy ofPrunusseeds. Paclobutrazol, a GA biosynthesis inhibitor, completely inhibited seed germination, and the inhibitory effect could be partially reversed by GA4, but not by GA3. Thus, dormancy inP. campanulataseeds is imposed by the covering layers. Dormancy break is accompanied by a decrease in ABA content of the covering layers and germination by an increase of embryonic GA4content.
Quantifying the oxygen sensitivity of seed germination using a population-based threshold model
Authors: Bradford Kent J. , Côme Daniel , Corbineau Françoise
Published: March 2007

Seeds vary widely in the sensitivity of germination to oxygen (O2) partial pressure, depending upon the species, temperature, dormancy state and physiological status of the seeds. Most analyses of the O2sensitivity of germination have focused on final germination percentages and estimated the O2percentage in air that is required to reduce germination to a given percentage (usually 50%). In contrast, we have applied a population-based threshold model utilizing time courses of germination to quantify three parameters related to seed germination sensitivity to O2availability: the median base (or threshold) O2percentage, the standard deviation of O2thresholds among seeds in the population, and an oxygen–time constant that relates O2percentage to germination timing. The model fits germination responses accurately across a wide range of O2concentrations. The response to O2was logarithmic in all cases, with the O2percentage required for 50% germination ranging from 21% to as low as 0.005%, depending upon the species, the temperature and the seed dormancy level. Modelling indicated that some seeds can adapt to low O2percentages and shift their thresholds to lower values over time. Lower temperatures decreased the minimum O2threshold, as did after-ripening. Seed priming generally reduced the oxygen–time constant and increased the standard deviation of germination responses, but had relatively little effect on the O2sensitivityper se. The population-based threshold model can be used to quantify the O2sensitivity of seed germination and to predict germination rates and percentages when O2availability is limiting.
A NOTE ON IMPOSING LOCAL CURVATURE IN GENERALIZED LEONTIEF MODELS
Authors: SERLETIS APOSTOLOS , SHAHMORADI ASGHAR
Published: March 2007

In this paper, we build on Ryan and Wales (1998) and Moschini (1999) and impose curvature conditions locally on the generalized Leontief model, introduced by Diewert (1974). In doing so, we exploit the Hessian matrix of second order derivatives of the reciprocal indirect utility function, unlike Ryan and Wales (1998) and Moschini (1999), who exploit the Slutsky matrix.
Calcium, diet and fracture risk: a prospective study of 1898 incident fractures among 34 696 British women and men
Authors: Key Timothy J , Appleby Paul N , Spencer Elizabeth A , Roddam Andrew W , Neale Rachel E , Allen Naomi E
Published: March 2007

Objective

The risk factors for fractures are incompletely understood. An outstanding question concerns the optimal amount of dietary calcium needed to minimise the risk of fracture.

Design

We examined the associations of dietary calcium and other nutrients with self-reported fracture risk in a prospective cohort study. Nutrient intakes were estimated using a semi-quantitative food-frequency questionnaire administered at recruitment.

Setting

The UK.

Participants

A total of 26 749 women and 7947 men aged 20–89 years.

Results

Over an average of 5.2 years of follow-up, 1555 women and 343 men reported one or more fractures, 72% of these resulting from a fall. Among women, fracture risk was higher at lower calcium intakes, with a relative risk of 1.75 (95% confidence interval (CI) 1.33–2.29) among women with a calcium intake of < 525 mg day− 1 compared with women with a calcium intake of at least 1200 mg day− 1 (test for linear trend, P < 0.001). The association of dietary calcium with fracture risk was stronger among women aged under 50 years at recruitment than among women aged 50 and above. Dietary calcium intake was not associated with fracture risk in men. Fracture risk was not related to the dietary intake of any other nutrient examined.

Conclusion

In this population, women with a low dietary calcium intake had an increased risk of bone fracture, and this association was more marked among younger women than among older women.