bluuebunny/crossref_metadata_2025 huggingface dataset:
Cultural tourism behaviour and preferences among the live‐performing arts audience: an application of the univorous–omnivorous framework
Authors: Barbieri Carla , Mahoney Edward
Published: December 2009

This study uses the omnivorous–univorous theoretical framework of the arts marketing studies to identify relationships between the live‐performing arts and cultural tourism behaviours and preferences. Patrons of a major performing arts centre were segmented in three groups — sporadic, univores and omnivores — and examined regarding their cultural tourism behaviours and preferences. Statistical analysis revealed significant differences among groups in terms of demographic characteristics, art and culture consumption and cultural tourism behaviour and preferences. Study results add to the body of knowledge of tourism, suggesting that the culture omnivorous consumption behaviour reported in art marketing studies is also relevant to cultural tourism. Results suggest the existence of omnivorous cultural tourists seeking a wide variety of cultural products and experiences. The identification of a group of individuals with little interest and consumption of culture, including cultural travel destinations, also emerges from this study. Copyright © 2009 John Wiley & Sons, Ltd.
Free deep circumflex iliac artery vascularised bone flap for reconstruction of the distal radius: Planning with CT angiography
Authors: Ting Jeannette W. C. , Rozen Warren M. , Leong James , Crock John
Published: December 2009

Distal radius fractures in the younger population are often comminuted and intra‐articular, which can increase the complexity of their management. In addition, these patients tend to place high demands on their wrists, and the prevention of functional arthritis necessitates excellent anatomical reduction. Complicated cases such as these are often limited in their management options. We present a complex case of distal radius fracture and bone loss in which initial therapy with nonvascularized bone graft failed, and osteomyelitis was a further complicating factor. With the aid of preoperative planning with computed tomographic angiography (CTA), a deep circumflex iliac artery (DCIA) bone flap was able to be assessed as a reconstructive option. The use of preoperative CTA, the first description of such imaging in this role, was able to delineate the bone to be harvested, confirm its vascular supply, and plan flap harvest. The use of a vascularized bone flap in this setting was thus undertaken and was able to provide an autologous anatomical support for the wrist while reducing the risk of recurrent infection and still preserving internal fixation. This unique application of the free DCIA bone flap was potentiated by CTA, achieving complete healing and good functional outcomes. © 2009 Wiley‐Liss, Inc. Microsurgery, 2010.
Sperm‐borne protein, PAWP, initiates zygotic development in Xenopus laevis by eliciting intracellular calcium release
Authors: Aarabi Mahmoud , Qin Zheng , Xu Wei , Mewburn Jeffrey , Oko Richard
Published: December 2009

We previously reported postacrosomal sheath WW domain binding protein (PAWP) as a candidate sperm borne, oocyte‐activating factor. PAWP enters the oocyte during fertilization and induces oocyte activation events including meiotic resumption, pronuclear formation, and egg cleavage. However, in order to provide proof that PAWP is a primary initiator of zygotic development it is imperative to show that PAWP initiates intracellular calcium signaling, which is considered essential for oocyte activation. Utilizing Xenopus laevis as our model, we injected recombinant PAWP or Xenopus sperm into metaphase II‐arrested oocytes and observed a significant rise in intracellular calcium levels over controls. Concurring intensities and durations of PAWP and sperm‐induced calcium waves, detected by infrared two‐photon laser‐scanning fluorescence microscopy, were prevented by coinjection of a competitive PPGY‐containing peptide derived from PAWP but not by the point‐mutated form of this peptide. This study also correlates PAWP and sperm‐induced calcium release with meiotic resumption in Xenopus. The similar mode of oocyte activation, and the ability of the competitive peptide in blocking both sperm‐ and PAWP‐induced calcium release, provide evidence for the first time that sperm‐anchored PAWP is a primary initiator of zygotic development. Mol. Reprod. Dev. 77: 249–256, 2010. © 2009 Wiley‐Liss, Inc.
Optimal operating policies in a commodity trading market with the manufacturer's presence
Authors: Zhao Hui , Bisi Arnab
Published: December 2009

With the help of the Internet and express delivery at relatively low costs, trading markets have become increasingly popular as a venue to sell excess inventory and a source to obtain products at lower prices. In this article, we study the operational decisions in the presence of a trading market in a periodic‐review, finite‐horizon setting. Prices in the trading market change periodically and are determined endogenously by the demand and supply in the market. We characterize the retailers'optimal ordering and trading policies when the original manufacturer and the trading market co‐exist and retailers face fees to participate in the trading market. Comparing with the case with no trading fees, we obtain insights into the impact of trading fees and the fee structure on the retailers and the manufacturer. Further, we find that by continually staying in the market, the manufacturer may use her pricing strategies to counter‐balance the negative impact of the trading market on her profit. Finally, we extend the model to the case when retailers dynamically update their demand distribution based on demand observations in previous periods. A numerical study provides additional insights into the impact of demand updating in a trading market with the manufacturer's competition. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Multi‐item capacitated lot‐sizing problems with setup times and pricing decisions
Authors: Önal Mehmet , Romeijn H. Edwin
Published: December 2009

We study a multi‐item capacitated lot‐sizing problem with setup times and pricing (CLSTP) over a finite and discrete planning horizon. In this class of problems, the demand for each independent item in each time period is affected by pricing decisions. The corresponding demands are then satisfied through production in a single capacitated facility or from inventory, and the goal is to set prices and determine a production plan that maximizes total profit. In contrast with many traditional lot‐sizing problems with fixed demands, we cannot, without loss of generality, restrict ourselves to instances without initial inventories, which greatly complicates the analysis of the CLSTP. We develop two alternative Dantzig–Wolfe decomposition formulations of the problem, and propose to solve their relaxations using column generation and the overall problem using branch‐and‐price. The associated pricing problem is studied under both dynamic and static pricing strategies. Through a computational study, we analyze both the efficacy of our algorithms and the benefits of allowing item prices to vary over time. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Initial testing of topotecan by the pediatric preclinical testing program
Authors: Carol Hernan , Houghton Peter J. , Morton Christopher L. , Kolb E. Anders , Gorlick Richard , Reynolds C. Patrick , Kang Min H. , Maris John M. , Keir Stephen T. , Watkins Amy , Smith Malcolm A. , Lock Richard B.
Published: December 2009

Background

Topotecan is a small molecule DNA topoisomerase I poison, that has been successful in clinical trials against pediatric solid tumors and leukemias. Topotecan was evaluated against the Pediatric Preclinical Testing Program (PPTP) tumor panels as part of a validation process for these preclinical models.

Procedures

In vivo three measures of antitumor activity were used: (1) an objective response measure modeled after the clinical setting; (2) a treated to control (T/C) tumor volume measure; and (3) a time to event (fourfold increase in tumor volume for solid tumor models, or ≥25% human CD45+ cells in the peripheral blood for acute lymphoblastic leukemia, ALL models) measure based on the median event‐free survival (EFS) of treated and control animals for each xenograft.

Results

Topotecan inhibited cell growth in vitro with IC50 values between 0.71 and 489 nM. Topotecan significantly increased EFS in 32 of 37 (87%) solid tumor xenografts and in all 8 of the ALL xenografts. Seventy‐five percent of solid tumors met EFS T/C activity criteria for intermediate (n = 17) or high activity (n = 7). Objective responses were noted in eight solid tumor xenografts (Wilms, rhabdomyosarcoma, Ewing sarcoma, neuroblastoma). Among the six neuroblastomas, three achieved a PR. For the ALL panel, two maintained CRs, three CRs, and two PRs were observed.

Conclusions

Topotecan demonstrated broad activity in vitro and in vivo against both the solid tumor and ALL panels, with significant tumor growth delay generated in all the panels. These results further demonstrate the validity of the PPTP panel for preclinical testing of new drugs. Pediatr Blood Cancer 2010;54:707–715. © 2009 Wiley‐Liss, Inc.
Transitioning childhood cancer survivors to adult‐centered healthcare: insights from parents, adolescent, and young adult survivors
Authors: Casillas Jacqueline , Kahn Katherine L. , Doose Michelle , Landier Wendy , Bhatia Smita , Hernandez Joanna , Zeltzer Lonnie K.
Published: December 2009

Objective: To determine Latino adolescent and young adults (AYA) cancer survivors' perceived barriers or facilitators to transition from pediatric to adult‐centered survivorship care and to also assess the parents' perspective of care.

Methods: Partnering with a community‐based organization that serves Latino survivors, we conducted a qualitative, constant comparative analytic approach exploring in‐depth themes that have salience for Latino pediatric cancer survivors seeking care in the adult healthcare setting. Twenty‐seven Latino AYA survivors (⩾15 years of age) completed key informant interviews and 21 Latino parents participated in focus groups.

Results: Both AYA survivors and parents identified two major facilitative factors for survivorship care: Involvement of the nuclear family in the AYA's survivorship care in the adult healthcare setting and including symptom communication in late effects discussions. Barriers to care included: perceived stigma of a cancer history and continued emotional trauma related to discussions about the childhood cancer experience.

Conclusions: Barriers to survivorship care include cancer stigma for both patient and nuclear family, which can impact on seeking survivorship care due to constraints placed on discussions because it remains difficult to discuss ‘cancer’ years later. Future research can evaluate if these findings are unique to Latino childhood cancer survivors or are found in other populations of AYA cancer survivors transitioning to adult‐centered healthcare. This community‐based participatory research collaboration also highlights the opportunity to learn about the needs of childhood cancer survivors from the lens of community leaders serving culturally diverse populations. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of site‐directed mutants of residues R58, R59, D116, W340 and R372 in the active site of E. coli cystathionine β‐lyase
Authors: Lodha Pratik H. , Jaworski Allison F. , Aitken Susan M.
Published: December 2009

Cystathionine β‐lyase (CBL) catalyzes the hydrolysis of L‐cystathionine (L‐Cth) to produce L‐homocysteine, pyruvate, and ammonia. A series of active‐site mutants of Escherichia coli CBL (eCBL) was constructed to investigate the roles of residues R58, R59, D116, W340, and R372 in catalysis and inhibition by aminoethoxyvinylglycine (AVG). The effects of these mutations on the kcat/K for the β‐elimination reaction range from a reduction of only 3‐fold for D116A and D116N to 6 orders of magnitude for the R372L and R372A mutants. The order of importance of these residues for the hydrolysis of L‐Cth is: R372 >> R58 > W340 ≈ R59 > D116. Comparison of the kinetic parameters for L‐Cth hydrolysis with those for inhibition of eCBL by AVG demonstrates that residue R58 tethers the distal carboxylate group of the substrate and confirms that residues W340 and R372 interact with the α‐carboxylate moiety. The increase in the pKa of the acidic limb and decrease in the pKa of the basic limb of the kcat/K versus pH profiles of the R58K and R58A mutants, respectively, support a role for this residue in modulating the pKa of an active‐site residue.
Retrospective analysis of prostate cancer recurrence potential with tissue metabolomic profiles
Authors: Maxeiner Andreas , Adkins Christen B. , Zhang Yifen , Taupitz Matthias , Halpern Elkan F. , McDougal W. Scott , Wu Chin‐Lee , Cheng Leo L.
Published: December 2009

BACKGROUND

In clinical care of prostate cancer patients, an improved method to assess the risk of recurrence after surgical treatment is urgently needed. We aim to retrospectively evaluate the ability of ex vivo tissue magnetic‐resonance‐spectroscopy‐based metabolomic profiles to estimate the risk of recurrence.

METHODS

PCa recurrence is defined biochemically as the detection of serum PSA after radical prostatectomy. Sixteen consecutive PCa‐recurrent cases, those with an initial PSA increase of 0.69 ± 0.26 ng/ml monitored 47.7 ± 2.6 months after prostatectomy were paired by age and Gleason score with cases without recurrence of the same pathological and clinical stages (n = 16/each). We analyzed ex vivo intact‐tissue spectroscopy results from these 48 individuals at the time of prostatectomy at 14T. From these spectra, we identified the 27 most common and intense spectral metabolic regions for statistical analyses.

RESULTS

Principal component analysis (PCA) on these spectral regions from cases of clinical‐stage‐matched groups with and without recurrence identified four pathology‐related principal components. Canonical analysis of these four and the first nine principal components for cases in the two groups defined metabolomic profiles as the canonical score that can differentiate the two groups with statistical significance. By applying the coefficients from PCA and canonical analysis to the pathological‐stage‐matched groups, recurrence was predicted with an accuracy of 78%.

CONCLUSIONS

Results indicate the potential of tissue metabolomic profiles measured with ex vivo spectroscopy to identify PCa aggressiveness in terms of cancer recurrence. With further study, this may greatly contribute to the future design of clinical strategy for personalized treatment of PCa patients. Prostate 70: 710–717, 2010. © 2009 Wiley‐Liss, Inc.
Natural oxidation of InN quantum dots: the role of cubic InN
Authors: González David , Lozano Juan G. , Herrera Miriam , Browning Nigel D. , Ruffenach Sandra , Briot Olivier , García Rafael
Published: December 2009

The natural aging process occured in indium nitride quantum dots (QDs) heterostructures as a consequence of exposure to the atmosphere has been studied by means of transmission electron microscopy and electron beam related techniques. The comparison between GaN‐capped and uncapped InN QDs kept at room conditions during 36 months indicates the structural changes that take place. While the capping layer seems to act in a protective way avoiding any change in the QDs, the uncapped structures suffer a series of phase transformations, where the original wurtzite structure is replaced by a layer of cubic phases. The main constituent of this layer is shown to be bcc‐In2O3 formed by the substitution of the nitrogen atoms by oxygen from the atmosphere. This supposes a transformation from a hexagonal to a cubic structure, explained by the existence of an oxygen‐rich cubic InN acting as an intermediate phase. The difference in the formation enthalpy between the original and the final product, together with the good match between the crystals would explain this transformation that shows the high instability of InN at environmental conditions. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deep traps analysis in AlGaN/GaN heterostructure transistors
Authors: Chikhaoui W. , Bluet J M. , Bru‐Chevallier C. , Dua C. , Aubry R.
Published: December 2009

AlGaN/GaN high electron mobility transistors are investigated by DLTS measurements. 6 different are extracted with the following activation energies: 0.12 eV, 0.15 eV, 0.21 eV, 0.42 eV, 0.49 eV and 0.94 eV. Based on comparison with literature results and measurements as a function of the pulse reverse bias, the trap localisation in the structure is discussed. Additional measurements as a function of the filling pulse duration reveal the presence of decorated extended defects in the samples. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prevalence and characteristics of female sexual dysfunction in a sample of women from Upper Egypt
Authors: Hassanin Ibrahim M.A. , Helmy Yasser A. , Fathalla Mohamed M.F. , Shahin Ahmed Y.
Published: December 2009

Objective

To study the prevalence and associated risk factors for female sexual dysfunction (FSD) in Upper Egypt.

Methods

Married women attending the outpatient clinic of Sohag University Hospital between February 2008 and March 2009 were recruited. Through direct interviews, each woman completed a questionnaire that included questions on sexual dysfunction.

Results

From 648 recruited patients, 47 declined to participate in the study. Of the 601 remaining participants, 462 women (76.9%) reported 1 or more sexual problems. Low sexual desire was the most common sexual problem (66.4%). Patients with FSD were significantly more likely to be older than 40 years, have sexual intercourse fewer than 3 times a week, have been married for 10 years or more, have 5 children or more, be circumcised, have a husband aged 40 years or more, and be postmenopausal. Age of the women maintained a statistically significant positive relationship with FSD in the regression model (odds ratio 1.39; 95% CI, 1.26–1.53).

Conclusions

There was a high prevalence of FSD in this sample of women from Upper Egypt. The prevalence of sexual problems increased with increasing age of the women.
“To Serve Revenge for the Dead”: Chinese Communist Responses to Japanese War Crimes in the PRC Foreign Ministry Archive, 1949–1956
Authors: Cathcart Adam , Nash Patricia
Published: December 2009

Using newly available documents from the PRC Foreign Ministry Archive, this article traces the evolving legacies of the War of Resistance in the first seven years of the People's Republic. Analysis is offered of PRC campaigns against Japanese bacteriological war crimes, criticisms of American dealings with Japanese war criminals, and the 1956 trial of Japanese at Shenyang. Throughout, behind-the-scenes tensions with the Soviet Union and internal bureaucratic struggles over the Japanese legacy regarding these matters are revealed. The article thereby aims to shed light on how the War of Resistance affected post-war China's foreign relations, demonstrating how the young Republic advantageously used wartime legacies as diplomatic tools in relations with the superpowers and within the orchestrated clangour of domestic propaganda campaigns.
GROUPS WITH ABELIAN SYLOW SUBGROUPS
Authors: BRANDL ROLF
Published: December 2009

Finite groups with abelian Sylow p-subgroups for certain primes p are characterized in terms of arithmetical properties of commutators.
Advances and challenges in malaria vaccine development
Authors: Wang Ruobing , Smith Joseph D. , Kappe Stefan H.I.
Published: December 2009

Malaria remains one of the most devastating infectious diseases that threaten humankind. Human malaria is caused by five different species ofPlasmodiumparasites, each transmitted by the bite of femaleAnophelesmosquitoes. Plasmodia are eukaryotic protozoans with more than 5000 genes and a complex life cycle that takes place in the mosquito vector and the human host. The life cycle can be divided into pre-erythrocytic stages, erythrocytic stages and mosquito stages. Malaria vaccine research and development faces formidable obstacles because many vaccine candidates will probably only be effective in a specific species at a specific stage. In addition,Plasmodiumactively subverts and escapes immune responses, possibly foiling vaccine-induced immunity. Although early successful vaccinations with irradiated, live-attenuated malaria parasites suggested that a vaccine is possible, until recently, most efforts have focused on subunit vaccine approaches. Blood-stage vaccines remain a primary research focus, but real progress is evident in the development of a partially efficacious recombinant pre-erythrocytic subunit vaccine and a live-attenuated sporozoite vaccine. It is unlikely that partially effective vaccines will eliminate malaria; however, they might prove useful in combination with existing control strategies. Elimination of malaria will probably ultimately depend on the development of highly effective vaccines.
Anglicans and Orthodox: The Cyprus Agreed Statement
Authors: Reid Duncan
Published: December 2009

Abstract

The article takes the form of a report on the current state of the international Anglican–Orthodox theological dialogue. It offers a critical reading of the Church of the Triune God: The Cyprus Agreed Statement of the International Commission for Anglican–Orthodox Theological Dialogue, 2006, outlining the major issues considered, together with points of convergence and continuing disagreement. Starting from acknowledged areas of previous agreement on questions of the Triune God and the nature of the Church, the statement gives special consideration to the issues arising from the ordination of women in provinces of the Anglican Communion. It considers the historical practice of ministry in both churches and the possibility of reception of new expressions of ministry. The theological question at the heart of these considerations is whether the ordination of women constitutes a church dividing matter. For this reason the statement gives some consideration to the terminology of heresy, schism and reception.
Anmerkungen zum Themenschwerpunkt Diagnostische Kompetenz von Lehrkräften
Authors: Schrader Friedrich-Wilhelm
Published: December 2009

Nach einem kurzen Überblick über die Artikel des Themenhefts wird ein Bezug zu allgemeinen Forschungsfragen zur Diagnosekompetenz von Lehrkräften hergestellt. Thematisiert werden methodische Aspekte der Erfassung diagnostischer Urteile, Probleme der Urteilsgenauigkeit sowie Kennzeichen und Korrelate diagnostischer Kompetenz. Schließlich werden einige Perspektive für die weitere Forschung angesprochen, insbesondere zur Erweiterung des Konstrukts und seinem Bezug zu anderen Lehrerkompetenzen.
Eingangsvoraussetzungen beim Studienbeginn
Authors: Klusmann Uta , Trautwein Ulrich , Lüdtke Oliver , Kunter Mareike , Baumert Jürgen
Published: December 2009

In öffentlichen Diskussionen über den Berufsstand der Lehrkräfte wird häufig die Annahme formuliert, dass sich für diesen Beruf Personen mit ungünstigen kognitiven und psychosozialen Merkmalen entschieden, was dazu führe, dass ein Teil der Lehrkräfte seine beruflichen Aufgaben nicht erfolgreich erfüllen könne. Allerdings haben nur wenige Studien die These von den negativen Selektionseffekten bei den kognitiven und psychosozialen Eingangsvoraussetzungen zukünftiger Lehrkräfte empirisch untersucht. Auf Basis einer Längsschnitterhebung mit über 2000 Abiturienten in Baden-Württemberg («Transformation des Sekundarschulsystems und Akademische Karrieren», TOSCA; Köller, Watermann, Trautwein & Lüdtke, 2004 ) vergleicht die vorliegende Arbeit die kognitiven Fähigkeiten, beruflichen Interessen und Persönlichkeitsmerkmale angehender Lehramtsstudierender mit den entsprechenden Merkmalen bei Studierenden anderer Fachrichtungen und untersucht darüber hinaus die relative Wichtigkeit dieser Merkmale bei der Studienwahl. Die Ergebnisse zeigen, dass sich die These einer generellen Negativ-Selektion in Bezug auf die kognitiven und psychosozialen Voraussetzungen von Lehramtsstudierenden empirisch nicht bestätigen lässt. Betrachtet man die Lehramtsstudierenden allerdings getrennt nach Schulart (Gymnasiallehramt vs. alle anderen Schulformen), findet sich eine negative Binnenselektion in Form von niedrigeren kognitiven Eingangsvoraussetzungen bei den zukünftigen Grund-, Haupt-, Real- und Sonderschullehrkräften im Vergleich zu den zukünftigen Gymnasiallehrkräften. Als prädiktiv für die Studienwahl erwiesen sich insbesondere die beruflichen Interessen, wobei die Entscheidung für ein Lehramtsstudium am deutlichsten durch eine ausgeprägte soziale Orientierung vorhergesagt werden konnte.
Von der Kostenerstattung zur leistungs- und ergebnisorientierten Vergütung – Eine Analyse des schweizerischen Gesundheitswesens mit Fokus auf dem stationären Bereich
Authors: Rieger  , Prengel  , Burla  , Rüdiger  , Pierer  , Heberer
Published: December 2009

Einleitung: Dem schweizerischen Gesundheitswesen steht die landesweite Einführung diagnosebezogener Fallpauschalen ab 2010 bevor. Zudem keimt in den Medien eine Diskussion über die Qualität medizinischer Leistungen auf. Vor diesem Hintergrund haben wir gegenwärtig angewendete schweizerische Entgeltsysteme und ihre Steuerungswirkungen analysiert, um mögliche zukünftige Entwicklungen abzuleiten. Methodik: Ausgehend von einer Erfassung der Verträge und Tarifordnungen am Universitätsspital Basel wurde eine Internet- und Literaturrecherche zu schweizerischen medizinischen Vergütungssystemen durchgeführt. Die dort beschriebenen Entgeltsysteme wurden mittels einer Typologie leistungsabhängiger Entgeltsysteme nach Entgeltmassstab und Entgeltobjekt klassifiziert. Die Steuerungswirkungen der Vergütungssysteme auf die Leistungserbringer wurden abgeleitet. Resultate: Als Entgeltmassstab können Kostenanfall, Kostenstandard oder verhandelte Preise herangezogen werden. Als Entgeltobjekt können Behandlungsaktivitäten, Behandlungsfälle oder Behandlungsergebnisse definiert werden. Ein Vergütungssystem kann zu Leistungsausweitung, Leistungsverminderung oder auch zu Patientenselektion führen. Im schweizerischen Gesundheitswesen ist eine Tendenz weg von traditionellem «Pay-for-Effort» (input-orientierte Vergütung) hin zur ergebnisorientierten Vergütung (Pay-for-Performance) zu beobachten. Die Entwicklung der Entgeltsysteme weist die diagnosebezogenen Fallpauschalen als zeit- und kontextbezogenen Zwischenschritt aus. Schlussfolgerungen: Eine Weiterentwicklung der medizinischen Vergütung im Sinne einer Berücksichtigung der Qualität medizinischer Leistungen sowie zu verhandelten Preisen erscheint langfristig in der Schweiz wahrscheinlich. Beides, Wirtschaftlichkeit und Qualität, sollten angemessen in einem Vergütungssystem berücksichtigt werden.
Diarrhöen, Übelkeit und Erbrechen
Authors: Senkel  , Fischer-Lampsatis
Published: December 2009

Ein 54-jähriger Patient, der bereits mehrfach wegen diverser Ulzerationen mit Blutungskomplikationen in Behandlung war, stellte sich mit Übelkeit und Erbrechen sowie Diarrhöen vor. Seit Jahren bestanden zudem rezidivierende Durchfälle. Laborchemisch war bereits einmal der V.a. einen neuroendokrinen Tumor gestellt worden, der sich dann aber intraoperativ nicht bestätigt hatte. Bei nach wie vor bestehendem Verdacht und erhöhten Chromogranin-A-Werten sowie erhöhtem Gastrinspiegel wurde eine Somatostatinrezeptor-Szintigraphie durchgeführt, in der sich ein Herd zeigte, der sich schliesslich als Metastase eines Gastrinoms unklarer Lokalisation identifizieren liess.
Glucose induces expression of rat pyruvate carboxylase through a carbohydrate response element in the distal gene promoter
Authors: Pedersen Kim B. , Buckley Rebecca S. , Scioneaux Ray
Published: December 2009

Pyruvate carboxylase is an enzyme of the so-called pyruvate cycling pathways, which have been proposed to contribute to glucose-stimulated insulin secretion in pancreatic β-cells. In the rat insulinoma cell line 832/13, transcripts from both the distal and proximal gene promoter for pyruvate carboxylase are up-regulated by glucose, with pyruvate carboxylase being expressed mainly from the distal gene promoter. At position −408 to −392 relative to the transcription start site, the distal gene promoter was found to contain a ChoRE (carbohydrate response element). Its deletion abolishes glucose responsiveness of the promoter, and the sequence can mediate glucose responsiveness to a heterologous gene promoter. ChREBP (carbohydrate response element-binding protein) and its dimerization partner Mlx (Max-like protein X) bind to the ChoRE in vitro. ChREBP further binds to the distal promoter region at a high glucose concentration in situ. The E-box-binding transcription factors USF1/2 (upstream stimulatory factor 1/2) and E2A variant 2 [also known as E47 and TCF3 (transcription factor 3)] can also bind to the ChoRE. Overexpression of E2A diminishes the magnitude of the glucose response from the pyruvate carboxylase ChoRE. This illustrates that competition between ChREBP–Mlx and other factors binding to the ChoRE affects glucose responsiveness. We conclude that a ChoRE in the distal gene promoter contributes to the glucose-mediated expression of pyruvate carboxylase.
Post-transcriptional regulation of MEK-1 by polyamines through the RNA-binding protein HuR modulating intestinal epithelial apoptosis
Authors: Wang Peng-Yuan , Rao Jaladanki N. , Zou Tongtong , Liu Lan , Xiao Lan , Yu Ting-Xi , Turner Douglas J. , Gorospe Myriam , Wang Jian-Ying
Published: December 2009

MEK-1 [MAPK (mitogen-activated protein kinase) kinase-1] is an important signal transducing enzyme that is implicated in many aspects of cellular functions. In the present paper, we report that cellular polyamines regulate MEK-1 expression at the post-transcriptional level through the RNA-binding protein HuR (Hu-antigen R) in IECs (intestinal epithelial cells). Decreasing the levels of cellular polyamines by inhibiting ODC (ornithine decarboxylase) stabilized MEK-1 mRNA and promoted its translation through enhancement of the interaction between HuR and the 3′-untranslated region of MEK-1 mRNA, whereas increasing polyamine levels by ectopic ODC overexpression destabilized the MEK-1 transcript and repressed its translation by reducing the abundance of HuR–MEK-1 mRNA complex; neither intervention changed MEK-1 gene transcription via its promoter. HuR silencing rendered the MEK-1 mRNA unstable and inhibited its translation, thus preventing increases in MEK-1 mRNA and protein in polyamine-deficient cells. Conversely, HuR overexpression increased MEK-1 mRNA stability and promoted its translation. Inhibition of MEK-1 expression by MEK-1 silencing or HuR silencing prevented the increased resistance of polyamine-deficient cells to apoptosis. Moreover, HuR overexpression did not protect against apoptosis if MEK-1 expression was silenced. These results indicate that polyamines destabilize the MEK-1 mRNA and repress its translation by inhibiting the association between HuR and the MEK-1 transcript. Our findings indicate that MEK-1 is a key effector of the HuR-elicited anti-apoptotic programme in IECs.
Iron-binding activity in yeast frataxin entails a trade off with stability in the α1/β1 acidic ridge region
Authors: Correia Ana R. , Wang Tao , Craig Elizabeth A. , Gomes Cláudio M.
Published: December 2009

Frataxin is a highly conserved mitochondrial protein whose deficiency in humans results in Friedreich's ataxia (FRDA), an autosomal recessive disorder characterized by progressive ataxia and cardiomyopathy. Although its cellular function is still not fully clear, the fact that frataxin plays a crucial role in Fe–S assembly on the scaffold protein Isu is well accepted. In the present paper, we report the characterization of eight frataxin variants having alterations on two putative functional regions: the α1/β1 acidic ridge and the conserved β-sheet surface. We report that frataxin iron-binding capacity is quite robust: even when five of the most conserved residues from the putative iron-binding region are altered, at least two iron atoms per monomer can be bound, although with decreased affinity. Furthermore, we conclude that the acidic ridge is designed to favour function over stability. The negative charges have a functional role, but at the same time significantly impair frataxin's stability. Removing five of those charges results in a thermal stabilization of ~24 °C and reduces the inherent conformational plasticity. Alterations on the conserved β-sheet residues have only a modest impact on the protein stability, highlighting the functional importance of residues 122–124.
Thr435 phosphorylation regulates RelA (p65) NF-κB subunit transactivation
Authors: O'Shea John M. , Perkins Neil D.
Published: December 2009

Phosphorylation of the RelA (p65) NF-κB (nuclear factor κB) subunit has been previously shown to modulate its ability to induce or repress transcription. In the present study we have investigated the consequences of Thr435 phosphorylation within the C-terminal transactivation domain of RelA. We confirm that Thr435 is phosphorylated in cells and is induced by TNFα (tumour necrosis factor α) treatment. Mutational analysis of this site revealed gene-specific effects on transcription, with a T435D phosphomimetic mutant significantly enhancing Cxcl2 (CXC chemokine ligand 2) mRNA levels in reconstituted Rela−/− mouse embryonic fibroblasts. Chromatin immunoprecipitation analysis revealed that this mutation results in enhanced levels of histone acetylation associated with decreased recruitment of HDAC1 (histone deacetylase 1). Moreover, mutation of this site disrupted RelA interaction with HDAC1 in vitro. Thr435 phosphorylation of promoter-bound RelA was also detected at NF-κB target genes following TNFα treatment in wild-type mouse embryonic fibroblasts. Phosphorylation at this site therefore provides an additional mechanism through which the specificity of NF-κB transcriptional activity can be modulated in cells.
Analysis of RGS2 expression and prognostic significance in stage II and III colorectal cancer
Authors: Jiang Zheng , Wang Zhimin , Xu Ye , Wang Beilan , Huang Wei , Cai Sanjun
Published: December 2009

The role of RGS2 (regulator of G-protein signalling 2) has been studied in several tumours. The purpose of the present study is to investigate the correlations between clinicopathological factors and patients' survival time and RGS2 expression in stage II and III CRC (colorectal cancer) patients. Real-time quantitative PCR was performed in 36 CRC tissues with recurrence and 28 without recurrence, and in three CRC-metastasis-derived cell lines (SW620, LoVo and Colo205) and 3 primary-CRC-derived ones (SW480, Caco-2 and HCT116) to examine RGS2 mRNA expression. In addition, to provide visualized evidence for RGS2 mRNA expression, random CRC samples were also performed with RT–PCR (reverse transcription–PCR). RGS2 protein was detected by immunostaining in 118 paraffin-embedded specimens, and the correlations between clinicopathological factors and survival time and RGS2 expression were analysed. We found that RGS2 mRNA was down-regulated both in CRC tissues with recurrence and metastasis-derived cell lines, and the expression level of RGS2 was unrelated to gender, age, tumour grade, or lymphovascular or perineural invasion. However, it was positively related to disease-free survival time (P<0.05). Furthermore, low RGS2 expression indicated a poorer survival rate (P<0.05, log-rank test). Multivariate analysis also showed that weak RGS2 protein expression was an independent adverse prognosticator in CRC (P<0.05). Taken together, we suggested that down-regulation of RGS2 might play an important role in CRC metastasis and predict poor prognosis in stage II and III CRC patients.
Development of radio-frequency identification sensors based on organic electronic sensing materials for selective detection of toxic vapors
Authors: Potyrailo Radislav A. , Surman Cheryl , Go Steven , Lee Yongjae , Sivavec Timothy , Morris William G.
Published: December 2009

Selective vapor sensors are demonstrated that involve the combination of (1) organic electronic sensing materials with diverse response mechanisms to different vapors and (2) passive 13.56 MHz radio-frequency identification (RFID) sensors with multivariable signal transduction. Intrinsically conducting polymers such as poly(3,4-ethylenedioxythiophene) and polyaniline (PANI) were applied onto resonant antennas of RFID sensors. These sensing materials are attractive to facilitate the critical evaluation of our sensing concept because they exhibit only partial vapor selectivity and have well understood diverse vapor response mechanisms. The impedance spectra Ž(f) of the RFID antennas were inductively acquired followed by spectral processing of their real Zre(f) and imaginary Zim(f) parts using principal components analysis. The typical measured 1σ noise levels in frequency and impedance magnitude measurements were 60 Hz and 0.025 Ω, respectively. These low noise levels and the high sensitivity of the resonant RFID sensor structures resulted in NH3 determinations with the 3σ detection limit down to 20 ppb. This achieved detection limit was 25–50-fold better over chemoresistor sensors based on PANI films and nanowires.
A single molecule as a dielectric medium
Authors: Mandal A. , Hunt K. L. C.
Published: December 2009

For three molecules with weak or negligible charge overlap, we prove that the three-body interaction energy obtained from quantum perturbation theory (to leading order) fits a dielectric model with a nonlocal electronic screening function. The electronic charge cloud of each molecule acts as a dielectric medium for the interaction of the remaining two with the nonlocal dielectric function ε(r,r′) obtained by O. S. Jenkins and K. L. C. Hunt [J. Chem. Phys. 119, 8250 (2003)], by considering the charge redistribution induced in a single molecule by an external perturbation. The dielectric function depends parametrically on the coordinates of the nuclei, within the Born–Oppenheimer approximation. We also prove that the force on each nucleus in molecule A depends on intramolecular dielectric screening within A. The potential from the charge distribution of B, screened by C acting as a dielectric medium, is further screened linearly within A; and similarly, with the roles of B and C reversed. In addition, the potential due to the unperturbed charge distribution of B and the potential due to the unperturbed charge distribution of C, acting simultaneously, are screened nonlinearly within A. The results show that nonlocal dielectric theory holds on the molecular level, provided that the overlap of the electronic charge distributions is weak.
Nonisolated spacelike focal and conjugate points in Lorentzian geometry
Authors: Ehrlich Paul E. , Kim Jong Ryul , Kim Seon-Bu
Published: December 2009

Nonisolated focal and conjugate points along a spacelike geodesic are investigated. We give examples of nonisolated focal points and provide conditions for such phenomenon motivated by Helfer’s example of nonisolated conjugate points and Kupeli’s definitions of degenerate focal and conjugate points.
Predictions of thermal boundary conductance for systems of disordered solids and interfaces
Authors: Beechem Thomas , Hopkins Patrick E.
Published: December 2009

As microsystems grow in their complexity, the number of material layers increases even as the thickness of these layers decreases. As a consequence, energetic transport through material intersections, the so-called thermal boundary conductance (TBC), becomes a greater contributor to the total thermal response of the system as a whole. Consequently, methods are sought that allow for insight into the mechanisms determining the efficiency of this transport, while simultaneously providing predictions with minimal computational investiture. In response, the current study extends the often employed diffuse mismatch model (DMM) to account for disorder that is frequently present in the materials making up the interface as well as the boundary itself. By applying assumptions regarding the scattering rates and mean free paths of phonons within a disordered solid, the resulting modifications of the spectral density of states induce changes in both the number and ratio of forward scattered phonons incident on a surface, and hence predictions of the TBC. Combining these assumptions with an accounting of the distance over which disorder persists, the newly implemented disorder DMM (δ-DMM) is shown to be more capable of predicting the TBC over a range of temperatures and material systems. Additionally, the model demonstrates that TBC is dependent on not only on the material properties but also on the morphology of these materials and the nature of their union.
Interaction between Na and Li in ZnO
Authors: Neuvonen Pekka T. , Vines Lasse , Kuznetsov Andrej Yu. , Svensson Bengt G. , Du Xiaolong , Tuomisto Filip , Hallén Anders
Published: December 2009

The interaction between group-Ia elements in ZnO have been studied by implanting Na into hydrothermally grown ZnO samples containing ∼4×1017 Li/cm3 and employing secondary ion mass spectrometry for sample analysis. Postimplantation annealing above 500 °C results in a diffusion of Na and concurrently Li is efficiently depleted from the regions occupied by Na. The data show unambiguously that Na and Li compete for the same trapping site and the results provide strong experimental evidence for that the formation energies of Na on Zn site together with that of interstitial Li are lower than those of Li on Zn site and interstitial Na in highly resistive ZnO. This conclusion is also supported by recent theoretical estimates of the formation energies of these species as a function of the Fermi-level position in ZnO.
Thermal and mechanical multistate folding of ribonuclease H
Authors: Schmitt Terry J. , Clark Jonathan E. , Knotts Thomas A.
Published: December 2009

Two different classes of experimental techniques exist by which protein folding mechanisms are ascertained. The first class, of which circular dichroism is an example, probes thermally-induced folding. The second class, which includes atomic force microscopy and optical tweezers, measures mechanically-induced folding. In this article, we investigate if proteins fold/unfold via the same mechanisms both thermally and mechanically. We do so using Ribonuclease H, a protein that has been shown to fold through a three-state mechanism using both types of experimental techniques. A detailed, molecular-level description of the states involved in thermal and mechanical folding shows that mechanisms for both types are globally similar, but small difference exist in the most unfolded conformations. Comparison to previous work suggests a universal folding behavior for proteins with a core helical bundle.
Raman spectroscopic determination of electron concentration in n-type GaInAsSb
Authors: Maslar J. E. , Hurst W. S. , Wang C. A.
Published: December 2009

Phonon-plasmon coupled mode Raman spectra of n-type GaInAsSb were measured at room temperature as a function of electron concentration. A relatively simple spectral model for the electronic contribution to the dielectric function was evaluated to determine the electron concentration from the bulk coupled mode spectra. The electron concentration was determined from a Raman spectrum by minimizing the sum of the squared residuals between a measured and a simulated spectrum. The only two fitting parameters were the Fermi energy and a plasmon damping parameter. The electron concentrations determined from the fits to the Raman spectra were compared to the electron concentrations determined from single magnetic field Hall effect measurements that were corrected to account for carriers in two conduction band minima. Compared to the results obtained from the Hall effect measurements, the electron concentrations obtained using Raman spectroscopy were as much as ≈19% lower at low doping levels but not more than ≈1% higher at higher doping levels. At lower carrier concentrations, the deviations are attributed to limitations of the spectral model. At higher carrier concentrations, the two methods were in good agreement. However, given the known limitations of this relatively simple spectral model, this agreement may be fortuitous; i.e., elements of the spectral model that tend to increase the apparent carrier concentration may be offset by elements that decrease the apparent carrier concentration.
Simulation study on the formation of vesicle and influence of solvent
Authors: Huang Jianhua , Wang Yan , Qian Changji
Published: December 2009

The spontaneous vesicle formation of amphiphiles A1B3s in solution has been studied using a lattice dynamic Monte Carlo simulation. The amphiphilic property of A1B3 chain is represented by the attraction between B-B beads. Two pathways of vesicle formation are observed for different strengths of repulsive interaction between B bead and solvent. In the first pathway, a bilayer disk is aggregated in a randomly dispersed system. It then bends and encapsulates solvents, and finally closes up to form a vesicle. In the second pathway, spherical aggregates are quickly assembled and grow through the coalescence of aggregates or the evaporation-condensation-like process. Then a vesicle is formed when A beads and solvents enter into the center of the aggregate.
Two-scale Brownian dynamics of suspensions of charged nanoparticles including electrostatic and hydrodynamic interactions
Authors: Dahirel V. , Jardat M. , Dufrêche J. F. , Turq P.
Published: December 2009

We propose here a multiscale strategy based on continuous solvent Brownian dynamics (BD) simulations to study the dynamical properties of aqueous suspensions of charged nanoparticles. We extend our previous coarse-graining strategy [V. Dahirel et al., J. Chem. Phys. 126, 114108 (2007)] to account for hydrodynamic interactions between solute particles. Within this new procedure, two BD simulations are performed: (1) The first one investigates the time scales of the counterions and coions (the microions) with only one nanoparticle in the simulation box but explicit microions, (ii) the second one investigates the larger time scale of the nanoparticles with numerous nanoparticles in the simulation box but implicit microions. We show how individual and collective transport coefficients can be computed from this two-scale procedure. To ensure the validity of our procedure, we compute the transport coefficients of a 10-1 model electrolyte in aqueous solution with a 1-1 added salt. We do a systematic comparison between the results obtained within the new procedure and those obtained with explicit BD simulations of the complete system containing several nanoparticles and explicit microions. The agreement between the two methods is found to be excellent: Even if the new procedure is much faster than explicit simulations, it allows us to compute transport coefficients with a good precision. Moreover, one step of our procedure also allows us to compute the individual transport coefficients relative to the microions (self-diffusion coefficients and electrophoretic mobility).
Ab initio study of noncovalent sidewall functionalization of carbon nanotubes
Authors: Lim Seokho , Park Noejung
Published: December 2009

We investigated noncovalent molecular adsorptions onto carbon nanotubes (CNTs), using density-functional theory methods including recently developed hybrid functionals. Planar aromatic molecules have greater binding strength than fully saturated nonaromatic molecules, and adsorption geometries are consistent with the features of intermolecular π−π stacking. We show that modifications with alcohol or a thiol terminal group increase the adsorption strength consistently throughout the considered molecules. This result may be used in experiments involving noncovalent sidewall functionalizations of CNTs.