bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of Embryonic Stem Cells into Anterior Definitive Endoderm
Authors: Livigni Alessandra , Villegas Santiago Nahuel , Oikonomopoulou Ifigenia , Rahman Afifah , Morrison Gillian M. , Brickman Joshua M.
Published: July 2009

Anterior definitive endoderm (ADE) is both an important embryonic signaling center and a unique multipotent precursor of liver, pancreas, and other visceral organs. Here we describe a method for the differentiation of mouse embryonic stem (ES) cells to endoderm with pronounced anterior character. ADE‐containing cultures can be produced in vitro by suspension (aggregation or embryoid body) culture and in a serum‐free adherent monolayer culture. Purified ES cell–derived ADE cells appear committed to endodermal fates and can undergo further differentiation in vitro towards liver and pancreas with enhanced efficiency. Curr. Protoc. Stem Cell Biol. 10:1G.3.1‐1G.3.10. © 2009 by John Wiley & Sons, Inc.
Lithium Storage in Carbon Nanostructures
Authors: Kaskhedikar Nitin A. , Maier Joachim
Published: July 2009

In this review article we discuss the progress of lithium storage in different carbon forms starting from intercalation in graphite to the lithium storage in fullerenes, nanotubes, diamond and most recently, graphene. The recent advances in lithium storage in various novel morphological variants of carbons prepared by a variety of techniques are also discussed with the most important models in literature that have been set out to explain the excess lithium storage. The major emphasis lies on the real structure.
A numerical study of mixing in a microchannel with circular mixing chambers
Authors: Ansari Mubashshir Ahmad , Kim Kwang‐Yong
Published: July 2009

The mixing of fluids in a microchannel is numerically investigated using three‐dimensional Navier–Stokes equations. The microchannel has circular mixing chambers that are designed to create a self‐circulating flow that operates at low Reynolds numbers. The investigations have been performed on a design that comprises of four circular mixing chambers that are joined together with constriction channels. The study has been carried out in two parts. Firstly, the mixing and the flow field are analyzed for a wide range (1–250) of the Reynolds number. Secondly, the effects of two design parameters, namely, the ratio, w/d, of the width of the constriction channel to the diameter of the circular chamber, and the angle, θ, between the outer walls of the chamber and the connection channel, on the mixing and the flow field have been evaluated. The mixing has been evaluated using a parameter, called mixing index, which is based on the variance of the mass fraction. The mixing index at the end of the device increases rapidly with the Reynolds number. The presence of a flow recirculation zone in the circular chamber is found to be effective in enhancing mixing, especially for larger Reynolds numbers. The mixing performance improves with an increase in θ, and with a decrease in w/d. The characteristics of the pressure drop have also been investigated as a function of the Reynolds number and geometric parameters. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Analysis and optimization of low‐pressure drop static mixers
Authors: Singh Mrityunjay K. , Kang Tae G. , Anderson Patrick D. , Meijer Han E. H. , Hrymak Andy N.
Published: July 2009

Various designs of the so called Low‐Pressure Drop (LPD) static mixer are analyzed for their mixing performance using the mapping method. The two types of LPD designs, the RR and RL type, show essentially different mixing patterns. The RL design provides globally chaotic mixing, whereas the RR design always yields unmixed regions separated by KAM boundaries from mixed regions. The crossing angle between the elliptical plates of the LPD is the key design parameter to decide the performance of various designs. Four different crossing angles from 90° to 160° are used for both the RR and RL designs. Mixing performance is computed as a function of the energy to mix, reflected in overall pressure drop for all designs. Optimization using the flux‐weighted intensity of segregation versus pressure drop proves the existence of the best mixer with an optimized crossing angle. The optimized angle proves to be indeed the LLPD design used in practice: the RL‐120 with θ = 120°, although RL‐140 θ = 140° performs as good. Shear thinning shows minor effects on the mixing profiles, and the main optimization conclusions remain unaltered. © 2009 American Institute of Chemical Engineers AIChE J, 2009
A comparison of text‐classification techniques applied to Arabic text
Authors: Kanaan Ghassan , Al‐Shalabi Riyad , Ghwanmeh Sameh , Al‐Ma'adeed Hamda
Published: July 2009

Many algorithms have been implemented for the problem of text classification. Most of the work in this area was carried out for English text. Very little research has been carried out on Arabic text. The nature of Arabic text is different than that of English text, and preprocessing of Arabic text is more challenging. This paper presents an implementation of three automatic text‐classification techniques for Arabic text. A corpus of 1445 Arabic text documents belonging to nine categories has been automatically classified using the kNN, Rocchio, and naïve Bayes algorithms. The research results reveal that Naïve Bayes was the best performer, followed by kNN and Rocchio.
Exploiting corpus‐related ontologies for conceptualizing document corpora
Authors: Zheng Hai‐Tao , Borchert Charles , Kim Hong‐Gee
Published: July 2009

As a greater volume of information becomes increasingly available across all disciplines, many approaches, such as document clustering and information visualization, have been proposed to help users manage information easily. However, most of these methods do not directly extract key concepts and their semantic relationships from document corpora, which could help better illuminate the conceptual structures within given information. To address this issue, we propose an approach called “Clonto” to process a document corpus, identify the key concepts, and automatically generate ontologies based on these concepts for the purpose of conceptualization. For a given document corpus, Clonto applies latent semantic analysis to identify key concepts, allocates documents based on these concepts, and utilizes WordNet to automatically generate a corpus‐related ontology. The documents are linked to the ontology through the key concepts. Based on two test collections, the experimental results show that Clonto is able to identify key concepts, and outperforms four other clustering algorithms. Moreover, the ontologies generated by Clonto show significant informative conceptual structures.
Stabilizing homeless young people with information and place
Authors: Woelfer Jill Palzkill , Hendry David G.
Published: July 2009

In this paper we examine how information—particularly, its organization and presentation—and “space” (i.e., a physical location) can be combined to create a particular “place” (i.e., a location adapted to a particular purpose) for engaging and stabilizing homeless young people, aged 13–25. Over 10 months, we used a participatory‐design research approach to investigate how an alliance of nine service agencies used information resources to support homeless young people. We collected 250 information resources and analyzed how these materials were organized and presented at four service agencies. In general, the agencies used ad hoc organizational schemes and presentations that were not in keeping with the key values of the alliance, which include human welfare, respect, trust, autonomy, and sustainability. To improve information delivery and the projection of common values, we followed a two‐step design process. First, based on a card‐sorting activity, we developed a new organizational scheme. Second, we developed four interrelated prototypes for presenting information resources: Rolling Case, InfoBike, Slat Wall, and Infold. To convey the use of these prototypes, three short video scenarios were created to demonstrate how the prototypes would be used by stakeholders, including homeless young people, staff, and volunteers. Feedback from stakeholders suggested that these prototypes, when sufficiently refined, could be useful and operationally viable. By investigating the concept of “place,” reconstituted through organizational schemes and novel presentations of information resources, this work creates possibilities that may allow grassroots service agencies to give more efficient access to information while expressing their values.
Twitter power: Tweets as electronic word of mouth
Authors: Jansen Bernard J. , Zhang Mimi , Sobel Kate , Chowdury Abdur
Published: July 2009

In this paper we report research results investigating microblogging as a form of electronic word‐of‐mouth for sharing consumer opinions concerning brands. We analyzed more than 150,000 microblog postings containing branding comments, sentiments, and opinions. We investigated the overall structure of these microblog postings, the types of expressions, and the movement in positive or negative sentiment. We compared automated methods of classifying sentiment in these microblogs with manual coding. Using a case study approach, we analyzed the range, frequency, timing, and content of tweets in a corporate account. Our research findings show that 19% of microblogs contain mention of a brand. Of the branding microblogs, nearly 20% contained some expression of brand sentiments. Of these, more than 50% were positive and 33% were critical of the company or product. Our comparison of automated and manual coding showed no significant differences between the two approaches. In analyzing microblogs for structure and composition, the linguistic structure of tweets approximate the linguistic patterns of natural language expressions. We find that microblogging is an online tool for customer word of mouth communications and discuss the implications for corporations using microblogging as part of their overall marketing strategy.
The new framework for understanding placental mammal evolution
Authors: Asher Robert J. , Bennett Nigel , Lehmann Thomas
Published: July 2009

An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of dermopterans within euarchontoglires. A variety of names for sub‐clades within the new placental mammal tree have been proposed, not all of which follow conventions regarding priority and stability. More importantly, the new phylogenetic framework enables the formulation of new hypotheses and testing thereof, for example regarding the possible developmental dichotomy that seems to distinguish members of the newly identified southern and northern radiations of living placental mammals.
Field‐based comparison of ligand and coactivator binding sites of nuclear receptors
Authors: Wohlfahrt Gerd , Sipilä Julius , Pietilä Lars‐Olof
Published: July 2009

A structure‐based comparison of the ligand‐binding domains of 35 nuclear receptors from five different subfamilies is presented. Their ligand and coactivator binding sites are characterized using knowledge‐based contact preference fields for hydrophobic and hydrophilic interactions implemented in the MOE modeling environment. Additionally, for polar knowledge‐based field points the preference for negative or positive electrostatic interactions is estimated using the Poisson‐Boltzmann equation. These molecular‐interaction fields are used to cluster the nuclear receptor family based on similarities of their binding sites. By analyzing the similarities and differences of hydrophobic and polar fields in binding pockets of related receptors it is possible to identify conserved interactions in ligand and coactivator binding pockets, which support e.g. design of specific ligands during lead optimization or virtual screening as docking filter. Examples of remarkable similarities between ligand binding sites of members from phylogenetically different nuclear receptor families (RXR, RAR, HNF4, NR5) and differences between closely related subtypes (LXR, RAR, TR) are discussed in more detail. Significant similarities and differences of coactivator binding sites are shown for NR3Cs, LXRs and PPARs. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 884–894, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Investigating the potential of Bacillus subtilis α‐amylase as a pressure‐temperature‐time indicator for high hydrostatic pressure pasteurization processes
Authors: Grauwet Tara , Van der Plancken Iesel , Vervoort Liesbeth , Hendrickx Marc E. , Loey Ann Van
Published: July 2009

The potential of Bacillus subtilis α‐amylase (BSA) as a pressure‐temperature‐time indicator (pTTI) for high pressure pasteurization processing (400–600 MPa; Ti 10–40°C; 1–15 min) was investigated. A stepwise approach was followed for the development of an enzyme‐based, extrinsic, isolated pTTI. First, based on literature data on the pressure stability, BSA was selected as a candidate indicator. Next to the accuracy and ease of the measurement of the indicator's response (residual activity) to the pressure treatment, the storage and handling stability of BSA at atmospheric pressure was verified. Second, the stability of BSA at a constant temperature (T) and time in function of pressure (p) was investigated. Solvent engineering was used to shift the inactivation window of BSA in the processing range of interest. Third, the enzyme (1 g/L BSA—MES 0.05 M pH 5.0) was kinetically calibrated under isobaric‐isothermal conditions. Time dependent changes in activity could be modeled best by a first‐order model. Except for low pressures and high temperatures, a synergistic effect between pressure and temperature could be observed. Based on the model selected to describe the combined p,T‐dependency of the inactivation rate constant, an elliptically shaped isorate contour plot could be constructed, illustrating the processing range where BSA can be used to demonstrate temperature gradients. Fourth, the validity of the kinetic model was tested successfully under dynamic conditions similar to those used in food industry. Finally, the indicator was found suitable to demonstrate nonuniformity in two‐sectional planes of a vertical, single vessel system. © 2009 American Institute of Chemical Engineers. Biotechnol. Prog., 2009
Efficient characterization of the TCR repertoire in lymph nodes by flow cytometry
Authors: Salameire D. , Le Bris Y. , Fabre B. , Fauconnier J. , Solly F. , Pernollet M. , Bonnefoix T. , Leroux D. , Plumas J. , Jacob M. C.
Published: July 2009

Analysis of the T‐cell receptor (TCR) repertoire by flow cytometry proved to be relevant for investigating T‐cell diversity and detecting reactive cells in blood samples. We used this approach to characterize non‐malignant T‐lymphocytes in lymph nodes and give insights into their origin. The TCR repertoire of CD4+ and CD8+ T‐cells from 81 lymph nodes was analyzed with a four‐color flow cytometer using a wide panel of 25 anti‐Vβ monoclonal antibodies. Flow cytometry proved to be a useful and informative technique. We demonstrated a diversified TCR‐Vβ repertoire, and only low level expansions, in 53% of the samples. They involved nearly all Vβ families, were more frequent in the CD8+ subset of older patients, but were not related to pathology. No evidence could be demonstrated in favor of stimulation by common antigens. Interestingly, the TCR‐Vβ repertoire proved to be very similar in lymph nodes and blood samples. Our results argue that in the cases studied, lymph node enlargement is mainly due to an increased homing of circulating T‐cells. They also provide reference values for expression of 25 TCR‐Vβ in lymph nodes, which could serve as a basis for further applications in diagnosis of T‐cell lymphoproliferative disorders. © 2009 International Society for Advancement of Cytometry
Fine‐needle aspiration (FNA) and pleural fluid cytology diagnosis of benign metastasizing pleomorphic adenoma of the parotid gland in the lung: A case report and review of literature
Authors: Zhang Yaxia , Gomez‐Fernandez Carmen R. , Jorda Merce , Ganjei‐Azar Parvin
Published: July 2009

Lesions that contain abundant benign myoepithelial cells, including pleomorphic adenomas of salivary gland origin, may present a diagnostic challenge in fine‐needle aspiration (FNA) specimens. Benign metastasizing pleomorphic adenoma is a rare neoplasm, in which the benign appearing pleomorphic adenoma, without any histological evidence of malignancy, metastasizes to distant sites including lung. In the absence of clinical history of a pre‐existing myoepithelial neoplasm, the presence of myoepithelial cells in the lung or any other organs besides salivary glands may create diagnostic difficulty. Here we present the cytologic findings of such a metastatic tumor found in the lung FNA and pleural fluid specimens from a 64‐year‐old woman, with a history of local recurrent salivary gland pleomorphic adenomas, who presented with multiple bilateral pulmonary nodules and pleural effusion. The diagnosis of benign metastasizing pleomorphic adenoma was made based on clinical information and cytomorphology, and confirmed by immunocytochemistry. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Cytologic detection of Stronyloides stercoralis in a 55‐year‐old Hispanic man with routine rectal/anal pap smear
Authors: Zhou Jianhong , Ferrer Hector , Cleveland Ronald , Ganesan Santhi
Published: July 2009

The anal–rectal cytology is introduced recently to evaluate human‐papillomavirus related cellular changes in the cells of anal canal. It is especially useful in high risk patients such as HIV patients. Very few reports were published regarding cytomorphological findings in anal cytology. Strongyloides stercoralis is an enteric helminthic parasite with particular significance in immunocompromised patients. The infection is asymptomatic or manifests as mild gastrointestinal symptoms in normal hosts. The infection can be devastating in immunocompromised persons, and carries a high mortality rate. The presence of S. stercoralis larva in anal–rectal pap smears is rare. We report a case in a routine anal–rectal Pap smear with Strongyloides, and discuss the clinical significance and life cycle of S. stercoralis. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Fine needle aspiration cytology in a case of fibrous dysplasia of jaw
Authors: Gupta Nalini , Gupta Ruchi , Bakshi Jaimanti , Rajwanshi Arvind
Published: July 2009

Fibro‐osseous lesions of the jaw comprise of a spectrum of diseases which include osseous dysplasia, fibrous dysplasia, and ossifying fibroma. The differentiation amongst these individual pathological lesions is difficult and a combined clinico‐radiological and histological correlation is essential for exact categorization. Fine needle aspiration cytology (FNAC) is frequently carried out to distinguish between benign and malignant lesions of the jaw as is a quick and reliable modality of investigation which guides in further management. We report, a case of a jaw swelling in a young male, diagnosed as fibrous dysplasia on FNAC. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Endometrial glandular and stromal breakdown, Part 3: Cytomorphology of “condensed cluster of stromal cells”
Authors: Norimatsu Yoshiaki , Yuminamochi Tsutomu , Shigematsu Yumie , Yanoh Kenji , Ikemoto Rie , Masuno Hiroshi , Murakami Manabu , Kobayashi Tadao K.
Published: July 2009

The aim of this study was undertaken to clarify the cytological characteristic of the “condensed clusters of stromal cells,” which may be recognized in endometrial glandular and stromal breakdown (EGBD) cases. The material consists of 60 cases of cytologic smears for which histopathological diagnosis was obtained by endometrial curettage; they comprised 30 cases of EGBD and 30 cases of endometrioid adenocarcinoma grade 1 (G1).

The following parameters were examined for “condensed clusters of stromal cells” in EGBD and for “clumps of cancer cells” in G1, respectively: (1) the occurrence of “condensed clusters of stromal cells”; (2) the nuclear shape; (3) a longer/shorter axis ratio in cell nuclei; (4) the area of cell nuclei; (5) the presence of overlapping nuclei; (6) nuclear crowding; (7) immunostaining.

(1) “Condensed clusters of stromal cells” were only observed in EGBD. (2) A reniform nuclear shape was observed in 100% EGBD (P < 0.0001) in comparison to G1 (3%). (3) The longer/shorter axis ratio in cell nuclei, G1 (1.37 ± 0.2) was significantly lower in comparison to EGBD (1.53 ± 0.12, P = 0.0005). (4) Nuclear area in G1 (51.6 ± 11.9, P < 0.0001) was significantly higher in comparison to EGBD (24.3 ± 3.9 μm2). (5) The score of overlapping nuclei in EGBD (2.5 ± 0.49) was significantly higher in comparison to G1 (1.8 ± 0.44, P < 0.0001). (6) The nuclear crowding score was the same both in EGBD (2) and G1 (2) and these findings were not statistically significant. (7) Both CD10 and Wilms' tumor protein 1 were positive in the “condensed clusters of stromal cells” in the EGBD. The anti‐cytokeratin staining was positive in “clumps of cancer cells” in the G1.

The evaluation of the immunocytochemical findings by combining the Wilms' tumor 1 protein, CD10, and the anti‐cytokeratin with the considered cytomorphologic features (reniform nucleus) may be useful for a correct diagnosis of EGBD in endometrial cytology. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
Genetic and gene–environment interaction effects on preschoolers' social behaviors
Authors: DiLalla Lisabeth Fisher , Elam Kit K. , Smolen Andrew
Published: July 2009

This study examined effects from a specific dopamine receptor gene (DRD4), environmental influences from parents and peers, and the interaction between them, on aggressive and prosocial behaviors of preschoolers. Children were classified as DRD4‐L (n = 27) if they had at least one DRD4 allele with six to eight repeats and as DRD4‐S (n = 35) if not. Parent–child interactions were coded when children were 3–4 years old. Peer interaction data and parent questionnaires were collected at age 5. DRD4‐L children shared less with each other and parents were less sensitive during parent–twin triadic interactions. Also, genotype interacted with peer aggression to affect children's aggression during a peer play interaction at age 5, and genotype interacted with prior parental sensitivity to affect later externalizing problems. Thus, children having a certain genetic disposition may be more sensitive to certain environmental stimuli and therefore more likely to exhibit aggressive behaviors under more stressful circumstances. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 451–464, 2009
Development of dynamic stability in children's rhythmic movement
Authors: James Eric G. , Hong S. Lee , Newell Karl M.
Published: July 2009

This study examined the hypothesis that the stability of rhythmic motor patterns increases with developmental age in children. Children aged 6 and 10 years and adults (18‐ to 23‐year‐olds) rocked back and forth at their preferred amplitude and frequency while seated on a wooden box placed atop a force platform. Participants performed the seated rocking task with their feet supported and unsupported. There was an age‐related decrease in rocking frequency and variability of the rocking cycle period, while the stability of the rocking dynamics increased, as indexed by the standard deviation of the phase angle of center of pressure motion. The presence of foot support decreased the stability of the rocking dynamics and reduced cycle period variability in the children, but not the adults. The results revealed that increments of age are associated with an increase in the stability of rhythmic motor patterns even when environmental conditions are altered. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 465–473, 2009
The ontogeny of exploratory behavior in male and female adolescent rats (Rattus norvegicus)
Authors: Lynn Debra A. , Brown Gillian R.
Published: July 2009

During adolescence, rats gain independence from their mothers and disperse from the natal burrow, with males typically dispersing further than females. We predicted that, if dispersal patterns are associated with responsiveness to novelty, exploratory behavior in novel environments would increase across adolescence, and males would explore more than females. Alternatively, females might explore more than males, if females are more motivated than males to learn about the immediate environment or if females have poorer spatial abilities than males. Twenty‐five male and 21 female rats were exposed to two novel environments (open field and elevated plus‐maze) during early, mid‐, or late adolescence. Total locomotion and amount of exploration directed towards aversive areas increased across adolescence, even when body weight was included as a covariate. Female adolescents locomoted more and spent more time exploring aversive areas than males. Developmental changes in neural function potentially underlie age and sex differences in exploratory behavior. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 513–520, 2009
Loss of dystrophin and the microtubule‐binding protein ELP‐1 causes progressive paralysis and death of adult C. elegans
Authors: Hueston Jennifer L. , Suprenant Kathy A.
Published: July 2009

EMAP‐like proteins (ELPs) are conserved microtubule‐binding proteins that function during cell division and in the behavior of post‐mitotic cells. In Caenorhabditis elegans, ELP‐1 is broadly expressed in many cells and tissues including the touch receptor neurons and body wall muscle. Within muscle, ELP‐1 is associated with a microtubule network that is closely opposed to the integrin‐based adhesion sites called dense bodies. To examine ELP‐1 function, we utilized an elp‐1 RNA interference assay and screened for synthetic interactions with mutated adhesion site proteins. We reveal a synthetic lethal relationship between ELP‐1 and the dystrophin‐like protein, DYS‐1. Reduction of ELP‐1 in a dystrophin [dys‐1(cx18)] mutant results in adult animals with motility defects, splayed and hypercontracted muscle with altered cholinergic signaling. Worms fill with vesicles, become flaccid, and die. We conclude that ELP‐1 is a genetic modifier of a C. elegans model of muscular dystrophy. Developmental Dynamics, 2009. © 2009 Wiley‐Liss, Inc.
Xenopus Wnt11b is identified as a potential pronephric inducer
Authors: Tételin Stéphanie , Jones Elizabeth A.
Published: July 2009

In this study, we aimed to establish if known wnt signaling molecules could be responsible for inducing early pronephros specification, using a novel and effective in vitro bioassay in Xenopus embryos. Anterior somites have the unique biological activity to signal to unspecified intermediate mesoderm to induce pronephros formation in Xenopus embryos. We have used a molecular candidate gene approach to analyze both canonical and noncanonical wnt expression in isolated anterior and posterior somites and dissected presumptive pronephros, pronephric anlagen, and pronephros from stage 12.5–35 embryos. We have identified potential candidate wnt genes expressed in the right time and place to specify pronephric development. These candidates were then directly tested in an in vitro pronephrogenesis assay based on Holtfreter sandwich cultures. Results revealed that noncanonical wnt11b and wnt11 can induce pronephros formation in vitro. Loss‐of‐function experiments confirmed that these genes are necessary for normal pronephros development. Developmental Dynamics 239:148–159, 2010. © 2009 Wiley‐Liss, Inc.
Efficiency of a modified backwater wetland in trapping a pesticide mixture
Authors: Lizotte Richard E. , Shields F. Douglas , Knight Scott S. , Bryant Charles T.
Published: July 2009

The pesticide trapping efficiency of a modified backwater wetland amended with a mixture of three pesticides, atrazine, S‐metolachlor, and fipronil, using a simulated runoff event, was examined. The 700‐m long, 25‐m wide wetland, located along the Coldwater River in Tunica County, Mississippi, USA, was modified for hydrologic control via weirs at both ends. A pesticide mixture was amended into the wetland at the upstream weir simulating a 1‐h, 1·27‐cm‐rainfall event from a 16 ha agricultural field. Water samples (1 l) were collected hourly within the first 24 h and again on days 2, 5, 7, 15, 21, 28 and 56, post‐injection at both ends of the wetland for pesticide analysis. Peak pesticide concentrations were observed upstream 1 h after injection. Rapid pesticide removal from upstream water occurred with 63, 51 and 61% decrease of atrazine, S‐metolachlor and fipronil, respectively, by 24 h. By day 7, 79, 80 and 87% decreases from peak concentrations occurred. After day 28, all pesticide concentrations were < 0·3 µg l−1, and after day 56, no target pesticides were detected. Downstream, atrazine occurred in trace amounts (<0·4 µg l−1) within 24 h and after day 28 was not detectable. S‐Metolachlor occurred once downstream on day 21 (0·249 µg l−1), and fipronil was detected on days 15–56 in trace amounts (<0·05 µg l−1). Results indicate that modified backwater wetlands can efficiently trap pesticides in runoff from agricultural fields during small to moderate rainfall events, mitigating impacts to receiving waters in the main river channel. Published in 2009 by John Wiley & Sons, Ltd.
Mycobacterium chelonae sensitisation induces CD4+‐mediated cytotoxicity against BCG
Authors: Ho Peiying , Zhang Lin , Wei Xing , Seah Geok Teng
Published: July 2009

Significant variability in efficacy of live Mycobacterium bovis BCG as a tuberculosis vaccine is observed globally. Effects of pre‐vaccination sensitisation to non‐tuberculous environmental mycobacteria (Env) are suspected to underlie this phenomenon, but the mechanisms remain unclear. We postulated that it could be due to Env‐specific T cells exerting cytotoxicity against BCG‐infected host cells. After murine sensitisation with heat‐killed antigens of different Env species, splenocytes from M. chelonae (CHE)‐sensitised mice exerted the strongest cytotoxicity against autologous BCG‐infected macrophages. This cytotoxicity was correlated with reduced BCG viability. The cytotoxicity was reduced by the depletion of CD4+, but not CD8+ or CD56+ cells, and CD4+ cells showed higher percentage of cytotoxicity than CD4− cells, supporting a role for CD4+ cells in CHE‐induced, BCG‐specific cytotoxicity. Additionally, this cytotoxicity was IFN‐γ, perforin and FasL dependent. After CHE‐sensitisation and subsequent BCG intranasal infection, there was significant expansion of lung CD4+ cells, the main cell type producing IFN‐γ. This was associated with 2‐ and 6‐fold reductions in lung BCG counts 1 and 3 wk, respectively post‐ infection, relative to non‐sensitised mice. This is the first report describing cytotoxicity against BCG‐infected cells as a mechanism underlying the influence of Env sensitisation on subsequent BCG responses.
Mechanisms determining cell membrane expression of different γδ TCR chain pairings
Authors: Boucontet Laurent , Grana Martin , Alzari Pedro M. , Pereira Pablo
Published: July 2009

We investigated the ability of the most common TCR‐γ and δ chains to express on the cell surface. Vγ1Cγ4 and Vγ7Cγ1 chains paired with all TCR‐δ chains tested, whereas Vγ4Cγ1 chains were found with Vδ4 and Vδ5, but not with Vδ2 or Vδ6 chains, and Vγ2Cγ2 chains were expressed only with Vδ5. Mapping studies showed that up to four polymorphic residues influence the different co‐expressions of Vγ1 and Vγ2 chains with Vδ chains. Unexpectedly, these residues are not located in the canonical γ/δ interface, but in the outer part of the γδ TCR complex exposed to the solvent. Expression of functional Vδ4 or Vδ6 chains in Vγ2/Vδ5+ cells or of functional Vγ2Cγ2 in Vγ1+ cells reduced cell‐surface expression of the γδ TCR. Taken together, these data show that (i) the Vγ/Vδ repertoire of mouse γδ T cells is reduced by physical constraints in their associations. (ii) Lack of Vγ2/Vδ expression is due to the formation of aberrant TCR complexes, rather than to an intrinsic inability of the chains to pair and (iii) despite not being expressed at the cell surface, the presence of a functionally rearranged Vγ2 chain in γδ T cells results in reduced TCR levels.
A roadmap for thymic epithelial cell development
Authors: Anderson Graham , Jenkinson Eric J. , Rodewald Hans‐Reimer
Published: July 2009

Thymic epithelial cells (TEC) are essential components of the thymus that guide and control the development and TCR repertoire selection of T cells. Previously, TEC have been considered as postmitotic cells that, once generated during ontogeny, were maintained in their mature state. Recently, it has become clear that TEC can be generated from common or committed medullary and cortical TEC progenitor cells in ontogeny, that stages of immature and mature TEC are phenotypically separable, and that TEC undergo a rapid turnover in a matter of a few weeks. All of these findings strongly suggest that in the adult thymus mature TEC are constantly regenerated from a pool of stem or progenitor cells, a view that renders the thymus structure potentially much more dynamic than previously thought. However, the identity of “thymus stem cells” is elusive, and developmental stages of TEC development are only beginning to be elucidated.
Variations of iridoid oleuropein in Italian olive varieties during growth and maturation
Authors: Ranalli Alfonso , Marchegiani Donato , Contento Stefania , Girardi Fabio , Nicolosi Maria Paola , Brullo Marco Desiderio
Published: July 2009

This research paper reports on the concentrations of oleuropein in fruits of seven Italian olive cultivars. These oleuropein levels, during fruit growth and maturation, were monitored by taking olive samples from the same olive trees grown in Middle Italy. A novel high‐resolution gas chromatography (HRGC) oleuropein quantification method and a new high‐performance liquid chromatography (HPLC) method were developed. The olive fruits showed high contents of oleuropein, which were greatly influenced by the olive cultivar (genetic store) factor. The stage of fruit growth and maturation was another factor strongly affecting the contents of iridoid oleuropein in olive drupes, whatever the olive cultivar considered. Green olives had much higher concentrations of this biofunctional glucoside, which decreased regularly during fruit growth and ripeness. No differences were observed between the two developed oleuropein quantification methods, which gave, for all the olive cultivars, average values of fruit oleuropein contents that were not statistically different. These two reliable repetitive methods, noticeably the HPLC one (which also showed a lower running time), could be used for routine determination of oleuropein in olive drupes. We observed that, in general, olive cultivars having high oleuropein concentrations in the fruits were also characterized by marked oleuropein contents in the leaves.
Preparation of W1/O/W2 emulsions and droplet size distribution measurements by pulsed‐field gradient nuclear magnetic resonance (PFG‐NMR) technique
Authors: Wolf Frederik , Hecht Lena , Schuchmann Heike P. , Hardy Edme H. , Guthausen Gisela
Published: July 2009

Multiple emulsions of W1/O/W2 type are of major interest in life sciences, offering possibilities for the encapsulation of water‐soluble active agents. In food science, they are also applied for fat reduction. The droplet size distributions of the inner and outer emulsions are of main importance as they influence the rheological and sensorial properties, the release kinetics, as well as the structural and microbial stability. However, the determination of the inner and outer droplet size distributions is a major challenge, as conventional measurement techniques cannot be applied. Pulsed‐field gradient nuclear magnetic resonance (PFG‐NMR) is well known as a non‐destructive tool for droplet size determination, especially in simple emulsions. In this work, double emulsions of the W1/O/W2 type were prepared with polyglycerol‐polyricinoleate (PGPR) and polyoxyethylen‐20‐sorbitan monolaurate (Tween 20) as emulsifiers by means of rotor‐stator emulsification machines. PFG‐NMR was applied for measurements of the inner phase (W1) droplet size distribution as well as for the characterization of the O phase. The W1 values were compared with results from laser light diffraction of simple emulsions (W1/O type) and were found to be consistent within the experimental errors, if restricted diffusion in the outer water phase (W2) and additional effects are considered.
Use of BPX‐70 60‐m GC columns for screening the fatty acid composition of industrial cookies
Authors: Vingering Nathalie , Ledoux Martial
Published: July 2009

The fatty acid (FA) composition of food is requested for labelling purposes and food composition tables. Suitable analytical methods for labelling purposes must be able to efficiently identify and accurately quantify FA as swiftly and cheaply as possible. This study evaluated a middle‐length highly polar column, the BPX‐70 60‐m column, to balance analysis efficiency and duration. The use of a 60‐m column led to the loss of data on minor FA but a gain in analysis time. The column was evaluated by analysing the FA composition of ten cookies made with different kinds of fats, including milk fat, and pure and/or partially hydrogenated vegetable oils. The FA elution order in this GC phase has been poorly documented in the literature compared to equivalent highly polar CPSil‐88 and SP‐2460 GC phases. Co‐elutions and overlaps on the BPX‐70 column were studied and commented upon. Overall, the BPX‐70 60‐m column could be used for rapid screening of the FA composition of simple foods. Analysis of the FA composition of a complex matrix, such as a dairy product, and specific analysis of trans‐FA required a longer highly polar column, possibly after fractionation by silver‐ion liquid chromatography. Compared to other GC phases, the BPX‐70 enabled effective isolation of 18:3 isomers although these isomers co‐eluted with 20:1 isomers on other highly polar GC phases. However, some CLA isomers co‐eluted with other FA on this column, and a specific analysis of these special FA would require another phase and/or different chromatographic conditions.
Introduction of Allyl and Prenyl Side‐Chains into Aromatic Systems by Suzuki Cross‐Coupling Reactions
Authors: Gerbino Darío C. , Mandolesi Sandra D. , Schmalz Hans‐Günther , Podestá Julio C.
Published: July 2009

This paper reports some studies aiming at the developement of a general protocol useful for the synthesis of allyl‐ and prenylaromatic compounds. The first part deals with the preparation of boron reagents like arylboronic acids and their pinacol esters as well as of pinacol allyl‐ and prenylboronates. The second part of the paper is devoted to the use of these boron reagents in Suzuki–Miyaura cross‐coupling reactions leading to allylation and prenylation of aromatic compounds. Of the six methods studied, the most promising results were obtained by using the Pd2(dba)3‐catalyzed reactions of arylboronic acids with allyl and prenyl bromides, that lead to the products of cross coupling in high yields (average 87%), and the reactions of aryl trifluoroborates with allyl and prenyl bromides catalyzed by Pd(OAc)2 that lead to the products of coupling in all cases in high yields (average 82%).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
N‐Allylideneamines Derived from Acrolein: Synthesis and Use as Acceptors of Two Nucleophiles
Authors: Mizota Isao , Matsuda Yuri , Hachiya Iwao , Shimizu Makoto
Published: July 2009

Two practical methods have been developed for the preparation of N‐allylideneamines 1b,c. One involves the isomerization of propargylamines and the other the dehydration of acrolein. N‐Allylideneamines 1b,c thus prepared were used as efficient substrates for 1,4‐ and 1,2‐double nucleophilic addition reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Biased evaluation of information during discussion: Disentangling the effects of preference consistency, social validation, and ownership of information
Authors: Mojzisch Andreas , Grouneva Lilia , Schulz‐Hardt Stefan
Published: July 2009

Group members tend to be biased in their evaluation of the information discussed. The present study aimed to disentangle the effects of preference consistency, social validation, and ownership on information evaluation in a single experimental design. Participants first received information about a personnel selection task. After having made a decision, they read a transcript of a fictitious discussion. In the transcript, preference consistency, social validation, and ownership of information were orthogonally manipulated as within‐subjects factors. As hypothesized, preference consistency, social validation, and ownership all increased the perceived quality of information. Furthermore, participants intended to discuss a larger proportion of their preference‐consistent information than of their preference‐inconsistent information. This discussion bias was significantly associated with the evaluation bias favoring preference‐consistent information. These results provide the first empirical demonstration that the evaluation of information in groups is characterized by three distinct biases and that biased evaluation of information may contribute to biased discussion of information. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of Analyte Flow Rate on Signal and Response Time of the Amperometric Gas Sensor with Nafion Membrane
Authors: Gębicki J. , Chachulski B.
Published: July 2009

This paper presents results of an investigation on influence of volumetric flow rate on the signal and response time of a prototype of sulfur dioxide gas sensor with Nafion membrane. The sensors differing in type of working electrode and composition of internal electrolyte were compared. We used Au and Pt working electrodes obtained via vacuum sublimation deposition on a Nafion membrane surface. The electrolytes were aqueous solutions of sulfuric acid of the summary concentration 5 mol dm−3 (electrolyte A). The electrolyte B contained an addition of dimethylsulfoxide (DMSO); the water/DMSO molar ratio was 2 : 1. Based on a proposed equation, which takes diffusion resistance into account, the obtained sensor signals were analyzed for the flow rate within a range of 0–100 cm3 min−1. The sensor response time was also determined for the above flow rate range.
Silicomolybdate‐Incorporated‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Modified Glassy Carbon Electrode as Amperometric Sensor for Bromate Determination
Authors: Thangamuthu R. , Wu Yu‐Ching , Chen Shen‐Ming
Published: July 2009

Silicomolybdate‐doped‐glutaraldehyde‐cross‐linked poly‐L‐lysine (PLL‐GA‐SiMo) film modified glassy carbon electrode was successfully prepared by means of electrostatically trapping the silicomolybdate anion in PLL‐GA cationic coating. The PLL‐GA‐SiMo film was stable and the charge transport through the film was fast. The modified electrode shows excellent electrocatalytic activity towards bromate reduction with significant reduction of overpotential. In amperometric determination of bromate, the calibration plot was linear over the concentration range of 5×10−5 to 1.2×10−3 M with a sensitivity of 3.6 μA mM−1. Furthermore, PLL‐GA‐SiMo film electrode showed fast response and good stability.
Characterization and identification of proteases secreted by Aspergillus fumigatus using free flow electrophoresis and MS
Authors: Neustadt Madlen , Costina Victor , Kupfahl Claudio , Buchheidt Dieter , Eckerskorn Christoph , Neumaier Michael , Findeisen Peter
Published: July 2009

Early diagnosis of life‐threatening invasive aspergillosis in neutropenic patients remains challenging because current laboratory methods have limited diagnostic sensitivity and/or specificity. Aspergillus species are known to secrete various pathogenetically relevant proteases and the monitoring of their protease activity in serum specimens might serve as a new diagnostic approach.For the characterization and identification of secreted proteases, the culture supernatant of Aspergillus fumigatus was fractionated using free flow electrophoresis (Becton Dickinson). Protease activity of separated fractions was measured using fluorescently labeled reporter peptides. Fractions were also co‐incubated in parallel with various protease inhibitors that specifically inhibit a distinct class of proteases e.g. metallo‐ or cystein‐proteases. Those fractions with high protease activity were further subjected to LC‐MS/MS analysis for protease identification. The highest protease activity was measured in fractions with an acidic pH range. The results of the ‘inhibitor‐panel’ gave a clear indication that it is mainly metallo‐ and serine‐proteases that are involved in the degradation of reporter peptides. Furthermore, several proteases were identified that facilitate the optimization of reporter peptides for functional protease profiling as a diagnostic tool for invasive aspergillosis.
Size‐based protein separations by microchip electrophoresis using an acid‐labile surfactant as a replacement for SDS
Authors: Root Brian E. , Zhang Bin , Barron Annelise E.
Published: July 2009

We demonstrate the use of an acid‐labile surfactant (ALS) as a replacement for SDS for size‐based protein separations in a microfluidic device. ALS is of interest to the proteomic field as it degrades at low pH and hence can be removed to reduce surfactant interference with down‐stream MS. A range of SDS and ALS concentrations were tested as denaturants for microchip electrophoresis to investigate their effects on the separation of proteins from 18 to 116 kDa and to provide a suitable comparison between the two surfactants. The electrophoretic mobilities of the proteins were not significantly affected by the use of ALS instead of SDS. Protein separations with ALS are performed in less than 3 min, which is a significant decrease in the time compared with the previous ALS separations on a slab gel format. We also demonstrate the use of poly‐N‐hydroxyethylacrylamide as a dynamic, hydrophilic chip channel coating that can be applied with a rapid and simple protocol for size‐based protein separation. The results reported here could significantly decrease the time and increase the attainable level of automation and integration of the front‐end protein fractionation required for “top‐down” proteomics.