bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of covariance with pre‐treatment measurements in randomized trials: Comparison of equal and unequal slopes
Authors: Funatogawa Ikuko , Funatogawa Takashi 
Published: August 2011

AbstractIn randomized trials, an analysis of covariance (ANCOVA) is often used to analyze post‐treatment measurements with pre‐treatment measurements as a covariate to compare two treatment groups. Random allocation guarantees only equal variances of pre‐treatment measurements. We hence consider data with unequal covariances and variances of post‐treatment measurements without assuming normality. Recently, we showed that the actual type I error rate of the usual ANCOVA assuming equal slopes and equal residual variances is asymptotically at a nominal level under equal sample sizes, and that of the ANCOVA with unequal variances is asymptotically at a nominal level, even under unequal sample sizes. In this paper, we investigated the asymptotic properties of the ANCOVA with unequal slopes for such data. The estimators of the treatment effect at the observed mean are identical between equal and unequal variance assumptions, and these are asymptotically normal estimators for the treatment effect at the true mean. However, the variances of these estimators based on standard formulas are biased, and the actual type I error rates are not at a nominal level, irrespective of variance assumptions. In equal sample sizes, the efficiency of the usual ANCOVA assuming equal slopes and equal variances is asymptotically the same as those of the ANCOVA with unequal slopes and higher than that of the ANCOVA with equal slopes and unequal variances. Therefore, the use of the usual ANCOVA is appropriate in equal sample sizes.
Kinetic and growth parameters of Arthrospira (Spirulina) platensis cultivated in tubular photobioreactor under different cell circulation systems
Authors: Ferreira Lívia S. , Rodrigues Mayla S. , Converti Attilio , Sato Sunao , Carvalho João C.M. 
Published: August 2011

AbstractArthrospira platensis was cultivated in tubular photobioreactor in order to evaluate growth and biomass production at variable photosynthetic photon flux density (PPFD = 60, 120, and 240 µmol photons m−2 s−1) and employing three different systems for cell circulation, specifically an airlift, a motor‐driven pumping and a pressurized system. The influence of these two independents variables on the maximum cell concentration (Xm), cell productivity (Px), nitrogen‐to‐cell conversion factor (YX/N), photosynthetic efficiency (PE), and biomass composition (total lipids and proteins), taken as responses, was evaluated by analysis of variance. The statistical analysis revealed that the best combination of responses' mean values (Xm = 4,055 mg L−1, Px = 406 mg L−1 day−1, YX/N = 5.07 mg mg−1, total lipids = 8.94%, total proteins = 30.3%, PE = 2.04%) was obtained at PPFD = 120 µmol photons m−2 s−1; therefore, this light intensity should be considered as the most well‐suited for A. platensis cultivation in this photobioreactor configuration. The airlift system did not exert any significant positive statistical influence on the responses, which suggests that this traditional cell circulation system could successfully be substituted by the others tested in this work. Biotechnol. Bioeng. 2012; 109:444–450. © 2011 Wiley Periodicals, Inc.
Determination of thyroid hormones and their metabolites in tissue using SPE UPLC‐tandem MS
Authors: Ackermans M. T. , Kettelarij‐Haas Y. , Boelen A. , Endert E. 
Published: August 2011

ABSTRACTA solid‐phase liquid chromatography tandem mass spectrometry (SPE LC‐MS/MS) method was developed to determine thyroid hormones and their metabolites in tissue samples. The separation was achieved using reversed‐phase ultra‐performance liquid chromatography (UPLC); the mass spectrometric detection was achieved by positive electrospray ionization and multiple reaction monitoring. Prior to the UPLC separation a sample cleanup with a cation exchange was performed. 13 C6 labeled internal standards were used for the thyroid hormones and their metabolites. The method was linear over a range from 0.23 to 90 nmol/L for thyroxine and from 0.23 to 9 nmol/L for the metabolites. The lower limit of quantification ranged from 0.98 to 1.73 pg on column. Intra‐ and total assay variation were <10 and <15%, respectively. This method enables us to link thyroid hormone tissue concentrations to local iodothyronine deiodinase expressions, which will enhance our understanding of the regulation of thyroid hormone metabolism on the tissue level. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative determination of uridine in rabbit plasma and urine by liquid chromatography coupled to a tandem mass spectrometry
Authors: Kang Wonku 
Published: August 2011

ABSTRACTRecently a pyrimidine nucleoside, uridine, has been show to have a protective effect on cultured human corneal epithelial cells, and on dry eye animal model and patients. In this study, we introduce a sensitive liquid chromatography/tandem mass spectrometry method for the determination of uridine in rabbit plasma and urine. After protein precipitation with methanol including methaqualone (internal standard), the analyte was chromatographed on a reversed‐phase column with a mobile phase of 0.1% formic acid aqueous solution and methanol (1:4, v/v). The accuracy and precision of the assay were in accordance with Food and Drug Administration regulations for the validation of bioanalytical methods. This method was used to measure the concentrations of uridine in plasma and urine after a single oral administration of 450 mg/kg uridine in rabbits. Copyright © 2011 John Wiley & Sons, Ltd.
The Role of Warning Behaviors in Threat Assessment: An Exploration and Suggested Typology
Authors: Reid Meloy J. , Hoffmann Jens , Guldimann Angela , James David 
Published: August 2011

ABSTRACTThe concept of warning behaviors offers an additional perspective in threat assessment. Warning behaviors are acts which constitute evidence of increasing or accelerating risk. They are acute, dynamic, and particularly toxic changes in patterns of behavior which may aid in structuring a professional's judgment that an individual of concern now poses a threat – whether the actual target has been identified or not. They require an operational response. A typology of eight warning behaviors for assessing the threat of intended violence is proposed: pathway, fixation, identification, novel aggression, energy burst, leakage, directly communicated threat, and last resort warning behaviors. Previous research on risk factors associated with such warning behaviors is reviewed, and examples of each warning behavior from various intended violence cases are presented, including public figure assassination, adolescent and adult mass murder, corporate celebrity stalking, and both domestic and foreign acts of terrorism. Practical applications and future research into warning behaviors are suggested. Copyright © 2011 John Wiley & Sons, Ltd.
Computational fluid dynamics modeling of mass transfer behavior in a bioreactor for hairy root culture. I. Model development and experimental validation
Authors: Liu Rui , Sun Wei , Liu Chun‐Zhao 
Published: August 2011

AbstractA two‐dimensional axisymmetric computational fluid dynamics (CFD) model based on a porous media model and a discrete population balance model was established to investigate the hydrodynamics and mass transfer behavior in an airlift bioreactor for hairy root culture. During the hairy root culture of Echinacea purpurea, liquid and gas velocity, gas holdup, mass transfer rate, as well as oxygen concentration distribution in the airlift bioreactor were simulated by this CFD model. Simulative results indicated that liquid flow and turbulence played a dominant role in oxygen mass transfer in the growth domain of the hairy root culture. The dissolved oxygen concentration in the hairy root clump increased from the bottom to the top of the bioreactor cultured with the hairy roots, which was verified by the experimental detection of dissolved oxygen concentration in the hairy root clump. This methodology provided insight understanding on the complex system of hairy root culture and will help to eventually guide the bioreactor design and process intensification of large‐scale hairy root culture. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Review of Computational fluid dynamics applications in biotechnology processes
Authors: Sharma C. , Malhotra D. , Rathore A. S. 
Published: August 2011

AbstractComputational fluid dynamics (CFD) is well established as a tool of choice for solving problems that involve one or more of the following phenomena: flow of fluids, heat transfer, mass transfer, and chemical reaction. Unit operations that are commonly utilized in biotechnology processes are often complex and as such would greatly benefit from application of CFD. The thirst for deeper process and product understanding that has arisen out of initiatives such as quality by design provides further impetus toward usefulness of CFD for problems that may otherwise require extensive experimentation. Not surprisingly, there has been increasing interest in applying CFD toward a variety of applications in biotechnology processing in the last decade. In this article, we will review applications in the major unit operations involved with processing of biotechnology products. These include fermentation, centrifugation, chromatography, ultrafiltration, microfiltration, and freeze drying. We feel that the future applications of CFD in biotechnology processing will focus on establishing CFD as a tool of choice for providing process understanding that can be then used to guide more efficient and effective experimentation. This article puts special emphasis on the work done in the last 10 years. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Catalytic Properties of Silver Vanadium Phosphates in n‐Butane Oxidation – Considerations on the Impact of the [VxOy] Substructure
Authors: Karpov Andrey , Dobner Cornelia‐Katharina , Glaum Robert , Schunk Stephan Andreas , Rosowski Frank 
Published: August 2011

AbstractCatalysts based on silver vanadium phosphates with a general chemical formula Ag2VPxOd (1 ≤ x ≤ 2; 6 ≤ d ≤ 8) have been prepared and tested in gas phase oxidation of n‐butane. This general chemical formula comprises the two known phosphates Ag2(VVO2)PO4 (x = 1; d = 6) and Ag2(VIVO)P2O7 (x = 2; d = 8) and one novel compound with an approximate composition Ag2VIV,VP1.6O7+δ (0 ≤ δ ≤ 0.5). Among the prepared compounds, Ag2(VVO2)PO4 shows the highest activity while Ag2(VIVO)P2O7 is completely inactive. The novel phase Ag2VIV,VP1.6O7+δ (0 ≤ δ ≤ 0.5) is the only compound with selectivity to maleic anhydride. A structure‐property relationship for the prepared catalysts is discussed.
Performance evaluation of an IEEE 802.11g mesh network with multiradio nodes
Authors: Bencini Luca , Fantacci Romano 
Published: August 2011

SUMMARYWireless mesh networks are usually formed by self‐organized nodes and characterized by high reliability and modularity, low‐cost deployment, and easiness of reconfigurability. In order to improve wireless mesh network performance, several approaches have been recently proposed. Among them, one promising solution seems to be the multiradio interface approach where nodes forming the mesh network are equipped with more than one radio interface. The aim of this paper is to provide an IEEE 802.11 distributed coordination function analytical model to study the behavior of single‐hop multi‐interface mesh networks in which nodes use a uniform random interface selection strategy to identify the radio interface to be used. The accuracy of the proposed analytical approach is validated by comparing analytical predictions with simulation results under actual conditions. Copyright © 2011 John Wiley & Sons, Ltd.
The development of whisker control in rats in relation to locomotion
Authors: Grant Robyn A. , Mitchinson Ben , Prescott Tony J. 
Published: August 2011

AbstractAdult rats sweep their large facial whiskers (macrovibrissae) back and forth in a rhythmic pattern known as “whisking”. Here we examine how these whisker movements develop in relation to other aspects of exploratory behavior, particularly locomotion. We analyzed 963 high‐speed video recordings of neonatal rats, from P1 (Post‐natal day 1) to P21, and measured the emergence of whisker control and of head, body, and limb movements. Prior to P11, whisker movements were largely limited to unilateral retractions accompanying head turns. Between P11 and P13 bilateral whisking emerged alongside increased forward locomotion and improved control of the head. Contact‐induced modulations of whisking symmetry, synchrony, and whisker spread emerge shortly thereafter but continue to develop until at least P18, coinciding with the emergence of adult‐like locomotion patterns such as rearing. Overall, whisking develops alongside increasing locomotor competence indicating that active vibrissal sensing plays an important role in the exploratory behavior of the developing animal. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:151‐168, 2012.
Paradigms, Policy and Governance: The Politics of Energy Regulation in the UK Post‐2000
Authors: Fudge Shane , Peters Michael , Mulugetta Yacob , Jackson Tim 
Published: August 2011

ABSTRACTThis paper considers the debate around energy policy and government regulation in the UK, considering Helm's idea that the current period can be conceptualized as a distinct ideological paradigm in the same way that both nationalization and privatization were enmeshed within particular political and economic goals. As he reasons, the first paradigm was based on nationalization and had the purpose of bringing vital services under public ownership and the second paradigm was constructed around the premises of liberalization and privatization. Drawing on the work of Mitchell, the paper explores Helm's observations on the link between ‘paradigms and policy’ to suggest that the failings of a market‐based approach to addressing climate change and energy security argue that a more radical shift in direction and thinking is needed. In particular, it is argued that the UK Government's more recent targets on reducing carbon emissions suggest the need for an energy policy agenda that is more clearly de‐linked from the current emphasis on market solutions and associated political thinking. It is argued that such a transition in policy would need to revolve around Kuhn's pre‐conditions of a ‘gestalt switch’ – as indicated in both previous UK regulatory approaches to energy. We suggest that, in much the same way as the dominant scientific consensus structured Kuhn's original conception of a paradigm, such a shift in policy will involve a ‘gestalt switch’, and a politically led shift away from the influence of thinking which currently remains rooted in previous infrastructural and ideological legacies. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
The Drivers and Outcomes of the Clean Development Mechanism in China
Authors: Thomas Sebastian , Dargusch Paul , Griffiths Andrew 
Published: August 2011

ABSTRACTThe Clean Development Mechanism (CDM) is a flexible market mechanism intended to reduce greenhouse emissions and promote sustainable development. China hosts a third of all registered CDM projects, and generates two‐thirds of all certified emissions reductions. Understanding the political economy of the CDM in China is therefore of critical importance in determining whether the CDM is an effective instrument to promote sustainable development and mitigate climate change. This paper discusses the nature and dynamics of CDM project development in China by analysing the 579 registered CDM projects operating in China as of 1 July 2009. The predominant activities are hydroelectric and wind power projects, with foreign involvement largely by European firms specializing in emerging carbon markets. The sustainability outcomes of projects in China are primarily economic, with environmental benefits largely restricted to cleaner production. The results suggest that the CDM is largely being employed as an ancillary device to attract foreign investment and further China's existing development agenda. We argue that the these results indicate the need for further reform of the CDM to achieve desired outcomes, and that China's approach to the design of integrated policy portfolios might be an example of how to achieve this. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
CD44 is critical for airway accumulation of antigen‐specific Th2, but not Th1, cells induced by antigen challenge in mice
Authors: Katoh Shigeki , Kaminuma Osamu , Hiroi Takachika , Mori Akio , Ohtomo Takayuki , Maeda Sachie , Shimizu Hiroki , Obase Yasushi , Oka Mikio 
Published: August 2011

AbstractCD44 is a cell adhesion molecule involved in lymphocyte infiltration of inflamed tissues. We previously demonstrated that CD44 plays an important role in the development of airway inflammation in a murine model of allergic asthma. In this study, we investigated the role of CD44 expressed on CD4+ T cells in the accumulation of T‐helper type 2 (Th2) cells in the airway using CD44‐deficient mice and anti‐CD44 monoclonal antibodies. Antigen‐induced Th2‐mediated airway inflammation and airway hyperresponsiveness (AHR) in sensitized mice were reduced by CD44‐deficiency. These asthmatic responses induced by the transfer of antigen‐sensitized splenic CD4+ T cells from CD44‐deficient mice were weaker than those from WT mice. Lack of CD44 failed to induce AHR by antigen challenge. Expression level and hyaluronic acid receptor activity of CD44, as well as Neu1 sialidase expression on antigen‐specific Th2 cells, were higher than those on antigen‐specific Th1 cells. Anti‐CD44 antibody preferentially suppressed the accumulation of those Th2 cells in the airway induced by antigen challenge. Our findings indicate that CD44 expressed on CD4+ T cells plays a critical role in the accumulation of antigen‐specific Th2 cells, but not Th1 cells, in the airway and in the development of AHR induced by antigen challenge.
The preTCR‐dependent DN3 to DP transition requires Notch signaling, is improved by CXCL12 signaling and is inhibited by IL‐7 signaling
Authors: Tussiwand Roxane , Engdahl Corinne , Gehre Nadine , Bosco Nabil , Ceredig Rod , Rolink Antonius G. 
Published: August 2011

AbstractThe requirement for Notch signaling during T‐cell development has been extensively studied. Nevertheless, the developmental stage at which it is required and whether additional signaling pathways are needed are still poorly understood. By using a stromal‐cell‐free culture system, we show that sorted double‐negative 3 (DN3) thymocytes only require a Delta‐like‐4‐induced Notch signal to differentiate into double‐positive (DP) cells. This differentiation process is preTCR‐α dependent. DN3 cells undergo 4–5 proliferation cycles, and the addition of the chemokine CXCL12 improves proliferation. IL‐7 blocks the differentiation of DN3 cells to DP cells but not the Notch‐induced proliferation of cultured DN3 cells. The impaired differentiation correlates with an inhibition of Rag‐2 up‐regulation. Overall, the in vitro stromal‐cell‐free culture system presented here also provides a powerful and unique tool for studying the mechanisms involved in the positive and negative selection of T cells.
N‐Heterocyclic‐Carbene‐Induced Monomerization of Sterically Encumbered Dialkylmagnesium and Dialkylmanganese Polymers
Authors: Kennedy Alan R. , Klett Jan , Mulvey Robert E. , Robertson Stuart D. 
Published: August 2011

AbstractThe sterically encumbered polymeric dialkyl complexes [M(CH2SiMe3)2]∞ [M = Mg, MnII] were deaggregated by the potent two‐electron σ‐donor, 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr), to yield the first examples of the monomeric three‐coordinate [M(CH2SiMe3)2]·donor complexes [M = Mg (1); Mn (2)]. Similarly, monomeric three‐coordinate species M[CH(SiMe3)2]2·IPr [M = Mg, (3); Mn, (4)] were obtained from the bulkier disilyl‐substituted alkyl [CH(SiMe3)2] congeners M[CH(SiMe3)2]2·ether by displacement of the ether by IPr. Complexes 1–4, which represent rare examples of N‐heterocyclic‐carbene‐stabilized dialkylmagnesium and dialkylmanganese species, were crystallographically characterized; the diamagnetic magnesium complexes were also characterized in an arene solution by 1H and 13C NMR spectroscopy.
(1R,2R)‐Bis[(S)‐prolinamido]cyclohexane Modified with Ionic Groups: The First C2‐Symmetric Immobilized Organocatalyst for Asymmetric Aldol Reactions in Aqueous Media
Authors: Kochetkov Sergei V. , Kucherenko Alexandr S. , Zlotin Sergei G. 
Published: August 2011

AbstractThe first C2‐symmetric immobilized organocatalyst for asymmetric aldol reactions containing the (1R,2R)‐bis[(S)‐prolinamido]cyclohexane unit tagged with two imidazolium+/PF6– ion pairs has been synthesized. In its presence, (hetero)aromatic aldehydes reacted with linear or cyclic ketones in aqueous media to yield chiral aldols with high diastereo‐ and enantioselectivities and the catalyst could be recovered and reused at least 10 times without any decrease in the reaction rate or selectivity.
Bifunctional 2,5‐Diketopiperazines as Efficient Organocatalysts for the Enantioselective Conjugate Addition of Aldehydes to Nitroolefins
Authors: Durini Marco , Sahr Florian A. , Kuhn Michael , Civera Monica , Gennari Cesare , Piarulli Umberto 
Published: August 2011

AbstractFour peptidomimics (3–6) containing the cis‐DKP‐1 or trans‐DKP‐2 scaffolds and either L‐Pro or D‐Pro were synthesized. DKP‐1 and DKP‐2 are bifunctional diketopiperazines formally derived from the head‐to‐tail cyclization of L‐aspartic acid and either (R)‐ or (S)‐2,3‐diaminopropionic acid, which feature aminomethyl and carboxymethyl side arms in the 3‐ and 6‐positions of the 2,5‐piperazindione ring. Peptidomimics (3–6) were tested as organocatalysts in the conjugate addition of several aldehydes to β‐nitrostyrene and (E)‐2‐(furan‐2‐yl)nitroethene with good to excellent diastereo‐ and enantioselectivities. Monte Carlo/Energy Minimization (MC/EM) conformational searches were performed on the four catalysts and their enamine derivatives with propanal to rationalize the observed stereoselectivity.
Dielectrophoresis‐assisted massively parallel cell pairing and fusion based on field constriction created by a micro‐orifice array sheet
Authors: Kimura Yuji , Gel Murat , Techaumnat Boonchai , Oana Hidehiro , Kotera Hidetoshi , Washizu Masao 
Published: August 2011

AbstractIn this paper, we present a novel electrofusion device that enables massive parallelism, using an electrically insulating sheet having a two‐dimensional micro‐orifice array. The sheet is sandwiched by a pair of micro‐chambers with immersed electrodes, and each chamber is filled with the suspensions of the two types of cells to be fused. Dielectrophoresis, assisted by sedimentation, is used to position the cells in the upper chamber down onto the orifices, then the device is flipped over to position the cells on the other side, so that cell pairs making contact in the orifice are formed. When a pulse voltage is applied to the electrodes, most voltage drop occurs around the orifice and impressed on the cell membrane in the orifice. This makes possible the application of size‐independent voltage to fuse two cells in contact at all orifices exclusively in 1:1 manner. In the experiment, cytoplasm of one of the cells is stained with a fluorescence dye, and the transfer of the fluorescence to the other cell is used as the indication of fusion events. The two‐dimensional orifice arrangement at the pitch of 50 μm realizes simultaneous fusion of 6×103 cells on a 4 mm diameter chip, and the fusion yield of 78–90% is achieved for various sizes and types of cells.