bluuebunny/crossref_metadata_2025 huggingface dataset:
Two approaches for the numerical determination of electromagnetic fields near material interfaces using radial basis functions in a meshless method
Authors: Gordon Richard K. , Hutchcraft W. Elliott
Published: September 2009

This article discusses the use of radial basis functions in the solution of partial differential equations. In particular, an investigation of how to implement boundary conditions at material interfaces is presented. A comparison is made of solutions obtained using only radial basis functions with those obtained using either jump functions or elliptical functions in conjunction with standard radial basis functions. The purpose of adding either jump functions or elliptical functions is to alleviate the inaccurate handling of the boundary conditions at material interfaces. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
The homotopy analysis method for solving higher dimensional initial boundary value problems of variable coefficients
Authors: Jafari H. , Saeidy M. , Firoozjaee M. A.
Published: September 2009

In this article, higher dimensional initial boundary value problems of variable coefficients are solved by means of an analytic technique, namely the Homotopy analysis method (HAM). Comparisons are made between the Adomian decomposition method (ADM), the exact solution and the homotopy analysis method. The results reveal that the proposed method is very effective and simple. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
On the potential use of adaptive control methods for improving adaptive natural resource management
Authors: Bond Craig A.
Published: September 2009

The paradigm of adaptive natural resource management (AM), in which experiments are used to learn about uncertain aspects of natural systems, is gaining prominence as the preferred technique for the administration of large‐scale environmental projects. To date, however, tools consistent with economic theory have yet to be used to either evaluate AM strategies or improve decision making in this framework. Adaptive control (AC) techniques provide such an opportunity. This paper demonstrates the conceptual link between AC methods, the alternative treatment of realized information during a planning horizon, and AM practices, shows how the different assumptions about the treatment of observational information can be represented through alternative dynamic programming model structures, and provides a means of valuing alternative treatments of information and augmenting traditional benefit–cost analysis through a decomposition of the value function. The AC approach has considerable potential to help managers prioritize experiments, plan AM programs, simulate potential AM paths, and justify decisions based on an objective valuation framework. Copyright © 2009 John Wiley & Sons, Ltd.
Ein Regenbogen in der Nacht. Optische Phänomene
Authors: Tillmanns Andrea
Published: September 2009

Die wenig bekannten Effekte der Ziliar‐Corona und des Linsen‐Halos lassen sich nicht durch atmosphärische Vorgänge erklären. In Wirklichkeit entstehen sie durch Beugungs‐ und Streueffekte im Auge. Interessanterweise werden diese beiden Phänomene bereits in Computerspielen berücksichtigt, während man sie in keinem Schul‐ oder Lehrbuch findet.
UniKat‐Flensburg. Flettner‐Rotor als alternativer Schiffsantrieb
Authors: Fiesser Lutz
Published: September 2009

Vor etwa zwei Jahren haben wir an der Universität Flensburg ein Boot mit Flettner‐Antrieb gebaut. Bei Tests konnten wir die euphorischen Erwartungen an die Leistung eines Rotorsegels nicht vollends bestätigen. Erreicht die Umfangsgeschwindigkeit des Rotors das Vierfache der aktuellen Windgeschwindigkeit, dann lässt sich der Vortrieb nicht weiter steigern. Dieser Sättigungseffekt war bislang unbekannt. Trotzdem belegen unsere Versuche mit dem UniKat‐Flensburg, dass ein Flettner‐Rotor in der Praxis extrem bedienerfreundlich ist.
Anschmiegsame Elektronik. Mechanik der Makroelektronik
Authors: Graz Ingrid
Published: September 2009

Herkömmliche Elektronik ist starr und zweidimensional, unsere Umwelt nicht. Die Makroelektronik hat möglichst großflächige elektronische Schaltungen zum Ziel, die flexibel, roll‐ und verbiegbar, sogar dehnbar sind. Ein geschicktes Design soll diese mechanischen Eigenschaften mit der elektronischen Funktionalität vereinbaren. Elektronische Bauteile lassen sich zum Beispiel in einer neutralen Zwischenschicht unterbringen, die beim Verbiegen und Rollen kaum gedehnt oder gestaucht wird. Schwieriger ist die Konstruktion dehnbarer Makroelektroniken, die sich konform an Objekte anschmiegen können. Die unterschiedlichen Konzepte nutzen metallische Filme und Halbleiter, die trickreich mit dehnfähigen Elastomerträgern kombiniert werden. Auch die Faltenbildung in der Natur dient als Vorbild, um hohe Dehnfähigkeit zu erreichen.
Einmal Mars und zurück. Probenrückführung vom Roten Planeten
Authors: Khan Michael
Published: September 2009

Eines der großen Ziele der Marsforschung besteht darin, mit einer unbemannten Sonde Proben von unserem Nachbarplaneten zur Erde zu holen. Eine solche Mars Sample Return‐Mission (MSR) ist jedoch erheblich aufwendiger als ein vergleichbares Unternehmen beim Mond. Für eine MSR werden zwei Raketen nötig sein. Eine bringt einen Orbiter, die andere eine Landeeinheit auf den Weg zum Mars. Der Rückflug ist mit einem schwierigen Rendezvous‐Manöver der Landeeinheit und des Orbiters in der Marsumlaufbahn verbunden, wie es in ähnlicher Form bei den – allerdings bemannten – Apollo‐Missionen am Mond stattgefunden hat. Außerdem muss man bei einer MSR sowohl beim Hin‐ als auch beim Rückflug das Startfenster beachten, weswegen die ganze Mission etwa fünf Jahre dauern wird.
Lichteinschluss in Zufallslasern
Authors: Fallert Johannes , Klingshirn Claus , Kalt Heinz
Published: September 2009

Zufallslaser (engl. Random Laser) stellen ein spannendes Gebiet aktueller Forschung dar und besitzen ein hohes Anwendungspotenzial. Die essentielle Frage nach dem Mechanismus der Lichtemission von Zufallslasern konnte jüngst unsere Gruppe am Karlsruher Institut für Technologie (KIT) klären.
Tropfen im Sandstrahl
Authors: Jäger Heinrich M.
Published: September 2009

Molekulare Anziehungskräfte sorgen dafür, dass Flüssigkeiten Tropfen bilden. Experimente an der Universität von Chicago haben jetzt gezeigt, dass Anziehungskräfte im Nanobereich auch in granularen Medien zu Tropfenbildung führen können, selbst wenn hier die Teilchen makroskopisch und mit bloßem Auge sichtbar sind.
Atomare Ladungszustände unter dem Rasterkraftmikroskop
Authors: Gross Leo , Mohn Fabian , Meyer Gerhard , Repp Jascha , Giessibl Franz J.
Published: September 2009

Die meisten Eigenschaften von Atomen sind durch die Zahl der Elektronen in ihrer äußeren Hülle bestimmt. Deshalb sind Messungen, die verschiedene Ladungszustände atomar aufgelöst unterscheiden können, von großer Bedeutung für die Grundlagenforschung. Auch für die Entwicklung zukünftiger, miniaturisierter Bauteile der Informationstechnik, die auf Speicherung und Transport einzelner Elektronen basieren soll, sind solche Messungen von fundamentalem Interesse. Unserer Gruppe ist es gelungen, den Ladungszustand von einzelnen Gold‐ und Silberatomen mit dem Rasterkraftmikroskop zu untersuchen.
Diplomphysiker als Lehrer
Authors: Fruböse Christian H.
Published: September 2009

Die gegenwärtige Anzahl von jährlich etwa 500 universitär ausgebildeten Lehramtsabsolventen im Fach Physik kann den Bedarf an Physiklehrern nicht decken. Viele Bundesländer bieten deshalb Diplomphysikern an, als Quer‐ oder Seiteneinsteiger in den Schuldienst einzutreten. Immerhin beträgt ihr Anteil inzwischen fast 50 % aller Neueinstellungen. Was gilt es dabei zu beachten?
Proteomic analysis of resting and thrombin‐stimulated platelets reveals the translocation and functional relevance of HIP‐55 in platelets
Authors: Tucker Katherine L. , Kaiser William J. , Bergeron Angela L. , Hu Hongbo , Dong Jing‐fei , Tan Tse‐Hua , Gibbins Jonathan M.
Published: September 2009

The platelet surface is a dynamic interface that changes rapidly in response to stimuli to co‐ordinate the formation of thrombi at sites of vascular injury. Tight control is essential as loss of organisation may result in the inappropriate formation of thrombi (thrombosis) or excessive bleeding. In this paper we describe the comparative analysis of resting and thrombin‐stimulated platelet membrane proteomes and associated proteins to identify proteins important to platelet function. Surface proteins were labelled using a biotin tag and isolated by NeurtrAvidin affinity chromatography. Liquid phase IEF and SDS‐PAGE were used to separate proteins, and bands of increased intensity in the stimulated platelet fractions were digested and identified by FT‐ICR mass spectrometry. Novel proteins were identified along with proteins known to be translocated to the platelet surface. Furthermore, many platelet proteins revealed changes in location associated with function, including G6B and Hip‐55. HIP‐55 is an SH3‐binding protein important in T‐cell receptor signalling. Further analysis of HIP‐55 revealed that this adaptor protein becomes increasingly associated with both Syk and integrin β3 upon platelet activation. Analysis of HIP‐55 deficient platelets revealed reduced fibrinogen binding upon thrombin stimulation, suggesting HIP‐55 to be an important regulator of platelet function.
Unintended changes in protein expression revealed by proteomic analysis of seeds from transgenic pea expressing a bean α‐amylase inhibitor gene
Authors: Chen Hancai , Bodulovic Greg , Hall Prudence J. , Moore Andy , Higgins Thomas J. V. , Djordjevic Michael A. , Rolfe Barry G.
Published: September 2009

Seeds of genetically modified (GM) peas (Pisum sativum L.) expressing the gene for α‐amylase inhibitor‐1 (αAI1) from the common bean (Phaseolus vulgaris L. cv. Tendergreen) exhibit resistance to the pea weevil (Bruchus pisorum). A proteomic analysis was carried out to compare seeds from GM pea lines expressing the bean αAI1 protein and the corresponding αAI1‐free segregating lines and non‐GM parental line to identify unintended alterations to the proteome of GM peas due to the introduction of the gene for αAI1. Proteomic analysis showed that in addition to the presence of αAI1, 33 other proteins were differentially accumulated in the αAI1‐expressing GM lines compared with their non‐GM parental line and these were grouped into five expression classes. Among these 33 proteins, only three were found to be associated with the expression of αAI1 in the GM pea lines. The accumulation of the remaining 30 proteins appears to be associated with Agrobacterium‐mediated transformation events. Sixteen proteins were identified after MALDI‐TOF‐TOF analysis. About 56% of the identified proteins with altered accumulation in the GM pea were storage proteins including legumin, vicilin or convicilin, phaseolin, cupin and valosin‐containing protein. Two proteins were uniquely expressed in the αAI1‐expressing GM lines and one new protein was present in both the αAI1‐expressing GM lines and their αAI1‐free segregating lines, suggesting that both transgenesis and transformation events led to demonstrable changes in the proteomes of the GM lines tested.
Quantifying Project Characteristics Related to Uncertainty
Authors: McLain David
Published: September 2009

Uncertainty is an important but difficult to quantify challenge for project managers. Despite this, some project characteristics associated with uncertainty are quantifiable and can provide project managers with clues to the amount of uncertainty in a project. This article shows how the following project characteristics can be quantified: (1) interdependencies among activities, (2) limited information about activity durations, and (3) unfamiliarity and variety in project work. Data from two example projects are used to demonstrate the calculation and interpretation of the resulting three uncertainty descriptors.
Fulminant pertussis: A multi‐center study with new insights into the clinico‐pathological mechanisms
Authors: Sawal Mohammad , Cohen Marta , Irazuzta Jose E. , Kumar Ramani , Kirton Christine , Brundler Marie‐Anne , Evans Clair Anne , Wilson John Andrew , Raffeeq Parakkal , Azaz Amer , Rotta Alexandre T. , Vora Ajay , Vohra Amit , Abboud Patricia , Mirkin L. David , Cooper Mehrengise , Dishop Megan K. , Graf Jeanine M. , Petros Andy , Klonin Hilary
Published: September 2009

Pertussis carries a high risk of mortality in very young infants. The mechanism of refractory cardio‐respiratory failure is complex and not clearly delineated. We aimed to examine the clinico‐pathological features and suggest how they may be related to outcome, by multi‐center review of clinical records and post‐mortem findings of 10 patients with fulminant pertussis (FP). All cases were less than 8 weeks of age, and required ventilation for worsening respiratory symptoms and inotropic support for severe hemodynamic compromise. All died or underwent extra corporeal membrane oxygenation (ECMO) within 1 week. All had increased leukocyte counts (from 54 to 132 × 109/L) with prominent neutrophilia in 9/10. The post‐mortem demonstrated necrotizing bronchitis and bronchiolitis with extensive areas of necrosis of the alveolar epithelium. Hyaline membranes were present in those cases with viral co‐infection. Pulmonary blood vessels were filled with leukocytes without well‐organized thrombi. Immunodepletion of the thymus, spleen, and lymph nodes was a common feature. Other organisms were isolated as follows; 2/10 cases Para influenza type 3, 2/10 Moraxella catarrhalis, 1/10 each with respiratory syncytial virus (RSV), a coliform organism, methicillin‐resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, Stenotrophomonas maltophilia, methicillin‐sensitive Staphylococcus aureus (MSSA), and candida tropicalis. We postulate that severe hypoxemia and intractable cardiac failure may be due to the effects of pertussis toxin, necrotizing bronchiolitis, extensive damage to the alveolar epithelium, tenacious airway secretions, and possibly leukostasis with activation of the immunological cascade, all contributing to increased pulmonary vascular resistance. Cellular apoptosis appeared to underlay much of these changes. The secondary immuno‐compromise may facilitate co‐infection. Pediatr Pulmonol. 2009; 44:970–980. ©2009 Wiley‐Liss, Inc.
Fidelity for qubits and photon states in tomographic probability representation
Authors: Man'ko O.V. , Man'ko V.I.
Published: September 2009

Review of the probability representation of quantum states based on the tomographic‐probability notion is presented. Classical and quantum states are studied and the difference of tomographic probabilities describing the states in both domains is elucidated. New expressions for fidelity in quantum domain in terms of the tomographic probabilities for both discrete qubit states and continuous quadrature components of photon are obtained.
Prohibitin regulates TGF‐β induced apoptosis as a downstream effector of smad‐dependent and ‐independent signaling
Authors: Zhu Brian , Zhai Jianjun , Zhu Haining , Kyprianou Natasha
Published: September 2009

BACKGROUND

Prohibitin (PHB), a protein located on the inner mitochondrial membrane and nuclei, is an intracellular effector of transforming growth factor‐β (TGF‐β) signaling in prostate cancer cells. This study investigated the involvement of PHB in the apoptosis and survival outcomes of human prostate cancer cell to TGF‐β. shRNA PHB loss of function in prostate cancer cells led to enhanced apoptotic response to TGF‐β via Smad‐dependent mechanism.

METHOD

TGF‐β activation of Raf‐Erk intracellular signaling, led to PHB phosphorylation, decreased inner mitochondrial permeability, and increased cell survival. Calcein‐based immunofluorescence studies revealed the functional involvement of PHB in maintaining inner mitochondrial membrane permeability as an integral component of TGF‐β induced apoptosis in prostate cancer cells.

RESULTS

These finding indicates that induction of TGF‐β apoptosis is mediated by Smad‐dependent and Smad‐independent signaling (MAPK) converging at PHB as a downstream effector regulating inner mitochondrial permeability. Putative PHB associated proteins were identified by subjecting TGF‐β treated cells to immunoprecipitation with anti‐PHB, and mass spectrometry. A screen for the kinase specific phosphorylation sites of PHB revealed three protein kinase (PKC) binding sites.

CONCLUSION

Our results demonstrate that TGF‐β led to upregulation of the PKC inhibitor 14‐3‐3 protein and promoted its association with PHB, while PHB association with PKC‐δ, was inhibited by the MEK1 inhibitor, documenting a critical interdependence between the MEK‐ERK signaling and prohibitin phosphorylation. These findings suggest a dual role for PHB as a downstream determinant of the cellular response to TGF‐β via Smad‐dependent pathway (apoptosis) and MAPK intracellular signaling (survival). Prostate 70: 17–26, 2010. © 2009 Wiley‐Liss, Inc.
CTEN/tensin 4 expression induces sensitivity to paclitaxel in prostate cancer
Authors: Li YouQiang , Mizokami Atsushi , Izumi Kouji , Narimoto Kazutaka , Shima Takashi , Zhang Jian , Dai Jinlu , Keller Evan T. , Namiki Mikio
Published: September 2009

BACKGROUND

Recently, we established paclitaxel‐resistant prostate cancer cell lines (PC‐3‐TxR and DU145‐TxR). To determine the mechanisms of paclitaxel resistance in PC‐3‐TxR cells, we compared the gene expression profiles between PC‐3 and PC‐3‐TxR cells. Our results indicated that expression of the C‐terminal tensin like protein (CTEN, tensin 4) gene was down‐regulated by 10‐fold in PC‐3‐TxR cells. We investigated the possibility that CTEN overexpression restores paclitaxel sensitivity.

METHODS

We investigated how knockdown and overexpression of CTEN in androgen‐independent cell lines affect paclitaxel sensitivity by colony formation assay and growth inhibition assay. To determine the mechanisms by which CTEN affects paclitaxel sensitivity, we investigated the relationships between CTEN and F‐actin or epidermal growth factor receptor (EGFR) in PC‐3 cells. We also examined the association between expression of CTEN and grade of prostate cancer by immunohistochemistry using tissue microarray analysis.

RESULTS

Down‐regulation of CTEN, which is located in the cytoskeleton, played an important role in paclitaxel resistance in PC‐3‐TxR cells. Knockdown of CTEN expression in PC‐3 cells induced paclitaxel resistance. Overexpression of CTEN in PC‐3‐TxR and DU145‐TxR cells restored paclitaxel sensitivity. CTEN expression was inversely correlated with F‐actin and EGFR expression. Then knockdown of actin and EGFR in PC‐3‐TxR cells recovered paclitaxel sensitivity, indicating that CTEN down‐regulation mediates paclitaxel resistance through elevation of EGFR and actin expression. Moreover, CTEN expression was inversely correlated with Gleason score.

CONCLUSIONS

These results strongly suggested that CTEN plays an important role in paclitaxel sensitivity and that CTEN expression level may be a prognostic predictive factor for PCa patients. Prostate 70: 48–60, 2010. © 2009 Wiley‐Liss, Inc.
Development of an advanced on‐line position‐specific stable carbon isotope system and application to methyl tert‐butyl ether
Authors: Gauchotte Caroline , O'Sullivan Gwen , Davis Simon , Kalin Robert M.
Published: September 2009

We present an advanced system for on‐line position‐specific carbon isotope analysis. The main limitation of on‐line intramolecular isotope ratio measurements has been that optimal pyrolytic fragments are obtained mostly at temperatures where the analyte has not completely reacted. As a result of undetermined isotopic fractionation, the isotopic signatures of the pyrolysis products are not strictly equal to these of the equivalent moieties in the parent molecule. We designed a pyrolytic unit in which both temperature and reaction time are variable parameters, enabling determination of the enrichment factor of the pyrolysis at optimal temperature by construction of a Rayleigh plot. In the case of methyl tert‐butyl ether (MTBE) presented here, a ‘pre‐pyrolysis’ fractionation of MTBE leading to a depletion of 0.9‰ was discovered and the enrichment factor of the optimal pyrolysis reaction was determined at −1.7‰. Absolute δ13C values of two functional groups of MTBE – the methoxy group and the 2‐methylpropane group – could be determined with 95% confidence intervals of 0.4‰ and 0.5‰, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
Semi‐global stabilization of discrete‐time systems subject to non‐right invertible constraints
Authors: Wang Xu , Saberi Ali , Stoorvogel Anton A. , Roy Sandip , Sannuti Peddapullaiah
Published: September 2009

This paper investigates time‐invariant linear systems subject to input and state constraints. We study discrete‐time systems with full or partial constraints on both input and state. It has been shown earlier that the solvability conditions of stabilization problems are closely related to important concepts such as the right invertibility or non‐right invertibility of the constraints, the location of constraint invariant zeros, and the order of constraint infinite zeros. In this paper, for general time‐invariant linear systems with non‐right invertible constraints, necessary and sufficient conditions are developed under which semi‐global stabilization in the admissible set can be achieved by state feedback. Sufficient conditions are also developed for such a stabilization in the case where measurement feedback is used. Such sufficient conditions are almost necessary. Controllers for both state feedback and measurement feedback are constructed as well. Copyright © 2009 John Wiley & Sons, Ltd.
A BMI approach for ℋ︁∞gain scheduling of discrete time‐varying systems
Authors: Borges Renato A. , Oliveira Ricardo C. L. F. , Abdallah Chaouki T. , Peres Pedro L. D.
Published: September 2009

The problem of gain‐scheduled state feedback control for discrete‐time linear systems with time‐varying parameters is considered in this paper. The time‐varying parameters are assumed to belong to the unit simplex and to have bounded rates of variation, which depend on the values of the parameters and can vary from slow to arbitrarily fast. An augmented state vector is defined to take into account possible time‐delayed inputs, allowing a simplified closed‐loop analysis by means of parameter‐dependent Lyapunov functions. A gain‐scheduled state feedback controller that minimizes an upper bound to the ℋ︁∞performance of the closed‐loop system is proposed. No grids in the parametric space are used. The design conditions are expressed in terms of bilinear matrix inequalities (BMIs) due to the use of extra variables introduced by the Finsler's lemma. By fixing some of the extra variables, the BMIs reduce to a convex optimization problem, providing an alternate semi‐definite programming algorithm to solve the problem. Robust controllers for time‐invariant uncertain parameters, as well as gain‐scheduled controllers for arbitrarily time‐varying parameters, can be obtained as particular cases of the proposed conditions. As illustrated by numerical examples, the extra variables in the BMIs can provide better results in terms of the closed‐loop ℋ︁∞performance. Copyright © 2009 John Wiley & Sons, Ltd.
Navigating with ranging radios: Five data sets with ground truth
Authors: Djugash Joseph , Hamner Bradley , Roth Stephan
Published: September 2009

Here we present five large data sets with range‐only measurements between a mobile robot and stationary nodes. Each data set consists of range measurements, surveyed locations of the stationary radio nodes, dead‐reckoned trajectory of the robot, and ground truth from a sophisticated inertial navigation system/global positioning system mounted on a robot traveling several kilometers at a time. Range measurements are made with two radio‐based ranging systems: a RFID tag‐based ranging system and an ultra–wide band ranging system. All the data are accurately time‐stamped and presented in standard formats (i.e., text files). In addition to the raw data, we present some noise characteristics of the two different ranging systems to offer insight into the quality of the range data from each system. © 2009 Wiley Periodicals, Inc.
LIDAR and vision‐based pedestrian detection system
Authors: Premebida Cristiano , Ludwig Oswaldo , Nunes Urbano
Published: September 2009

A perception system for pedestrian detection in urban scenarios using information from a LIDAR and a single camera is presented. Two sensor fusion architectures are described, a centralized and a decentralized one. In the former, the fusion process occurs at the feature level, i.e., features from LIDAR and vision spaces are combined in a single vector for posterior classification using a single classifier. In the latter, two classifiers are employed, one per sensor‐feature space, which were offline selected based on information theory and fused by a trainable fusion method applied over the likelihoods provided by the component classifiers. The proposed schemes for sensor combination, and more specifically the trainable fusion method, lead to enhanced detection performance and, in addition, maintenance of false‐alarms under tolerable values in comparison with single‐based classifiers. Experimental results highlight the performance and effectiveness of the proposed pedestrian detection system and the related sensor data combination strategies. © 2009 Wiley Periodicals, Inc.
Anodic silver (II) oxides investigated by combined electrochemistry, ex situ XPS and in situ X‐ray absorption spectroscopy
Authors: Lützenkirchen‐Hecht Dirk , Strehblow Hans‐Henning
Published: September 2009

Silver (II) oxide layers (AgO) were prepared by anodic oxidation of pre‐oxidized, Ag2O‐covered silver electrodes in 1 M NaOH (pH 13.8). The oxidized electrodes were investigated using a combination of electrochemical techniques, ex situ X‐ray photoelectron spectroscopy (XPS) and in situ surface‐sensitive grazing incidence X‐ray absorption spectroscopy (EXAFS) under full potential control. The application of these different techniques leads to a detailed, consistent picture of the anodic silver (II) oxide layer formation. The experiments have shown that the chemical composition of the AgO layer varies significantly with oxidation potential, revealing a decreasing oxygen deficiency with increasing anodization potential and oxidation time. XPS as well as EXAFS experiments support the interpretation of the oxide as a mixed valence Ag+Ag3+O2 with different contributions of Ag+ and Ag3+ species, depending on potential and anodization time. Copyright © 2009 John Wiley & Sons, Ltd.
XPS study of early stages of Al/Au interface formation
Authors: Polyak Yaroslav , Bastl Zdeněk
Published: September 2009

The interface formation between Au polycrystalline substrate kept at temperature of liquid nitrogen and Al deposit and its evolution during sample thermal treatments have been investigated by means of XPS. The intermixing of the Al and Au atoms at the interface occurred readily already at temperature of liquid nitrogen and resulted in the appearance of well‐resolved components on the high‐binding‐energy side of the Au(4f) spectra assignable to AlAu intermetallic phase. The sample annealing resulted in the growth of the amount of intermetallic compound formed at liquid nitrogen temperature. The formation of the initial AlAu phase at the Al/Au interface in our experimental conditions can be explained on the basis of its thermodynamic stability. Copyright © 2009 John Wiley & Sons, Ltd.
Adaptive group sequential design for phase II clinical trials: A Bayesian decision theoretic approach
Authors: Chen Yiyi , Smith Brian J.
Published: September 2009

Bayesian decision theoretic approaches (BDTAs) have been widely studied in the literature as tools for designing and conducting phase II clinical trials. However, full Bayesian approaches that consider multiple endpoints are lacking. Since the monitoring of toxicity is a major goal of phase II trials, we propose an adaptive group sequential design using a BDTA, which characterizes efficacy and toxicity as correlated bivariate binary endpoints. We allow trade‐off between the two endpoints. Interim evaluations are conducted group sequentially, but the number of interim looks and the size of each group are chosen adaptively based on current observations.

We utilize a loss function consisting of two components: the loss associated with accruing, treating, and monitoring patients, and the loss associated with making incorrect decisions. The performance of our Bayesian modeling, and the operating characteristics of decision rules under a wide range of loss function parameters are evaluated using seven scenarios in a simulation study.

Our method is illustrated in the context of a single‐arm phase II trial of bevacizumab, gemcitabine, and oxaliplatin in patients with metastatic pancreatic adenocarcinoma. Copyright © 2009 John Wiley & Sons, Ltd.
CD15, CD24, and CD29 Define a Surface Biomarker Code for Neural Lineage Differentiation of Stem Cells
Authors: Pruszak Jan , Ludwig Wesley , Blak Alexandra , Alavian Kambiz , Isacson Ole
Published: September 2009

Identification and use of cell surface cluster of differentiation (CD) biomarkers have enabled much scientific and clinical progress. We identify a CD surface antigen code for the neural lineage based on combinatorial flow cytometric analysis of three distinct populations derived from human embryonic stem cells: (1) CD15+/CD29HI/CD24LO surface antigen expression defined neural stem cells; (2) CD15−/CD29HI/CD24LO revealed neural crest-like and mesenchymal phenotypes; and (3) CD15−/CD29LO/CD24HI selected neuroblasts and neurons. Fluorescence-activated cell sorting (FACS) for the CD15−/CD29LO/CD24HI profile reduced proliferative cell types in human embryonic stem cell differentiation. This eliminated tumor formation in vivo, resulting in pure neuronal grafts. In conclusion, combinatorial CD15/CD24/CD29 marker profiles define neural lineage development of neural stem cell, neural crest, and neuronal populations from human stem cells. We believe this set of biomarkers enables analysis and selection of neural cell types for developmental studies and pharmacological and therapeutic applications.

Disclosure of potential conflicts of interest is found at the end of this article.
Real world contexts in PISA science: Implications for context‐based science education
Authors: Fensham Peter J.
Published: September 2009

The PISA assessment instruments for students' scientific literacy in 2000, 2003, and 2006 have each consisted of units made up of a real world context involving Science and Technology, about which students are asked a number of cognitive and affective questions. This article discusses a number of issues from this use of S&T contexts in PISA and the implications they have for the current renewed interest in context‐based science education. Suitably chosen contexts can engage both boys and girls. Secondary analyses of the students' responses using the contextual sets of items as the unit of analysis provides new information about the levels of performance in PISA 2006 Science. Embedding affective items in the achievement test did not lead to gender/context interactions of significance, and context interactions were less than competency ones. A number of implications for context‐based science teaching and learning are outlined and the PISA 2006 Science test is suggested as a model for its assessment. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 884–896, 2009
Chlorpyrifos and endosulfan affect buffalo oocyte maturation, fertilization, and embryo development in vitro directly and through cumulus cells
Authors: Nandi S. , Gupta P.S.P. , Roy S.C. , Selvaraju S. , Ravindra J.P.
Published: September 2009

This study was undertaken to examine the effect of 10 different levels (0, 0.005, 0.01, 0.02, 0.05, 0.1, 0.5, 1.0, 2.0, and 4.0 μg/mL) of two pesticides (chlorpyrifos and endosulfan) on buffalo oocyte viability, maturation, fertilization, and developmental competences in vitro. Studies were conducted to test the development of oocytes cultured with pesticides during maturation, fertilization, and during different embryo development stages. We also conducted experiments to test the hypotheses that the effects of these pesticides are hormones and somatic cells mediated. We observed a dose dependant decline in viability and developmental competence rates of oocytes. Chlorpyrifos and endosulfan had a negative impact on oocytes at 0.02 and 0.1 μg/mL levels, respectively. These pesticides reduced the oocyte nuclear maturation by a direct effect on oocytes, cumulus cell‐mediated action, and by blocking the action of hormones. Chlorpyrifos was found to be more ovotoxic and embryotoxic than endosulfan. This study will provide information on dose‐response relationship and risk assessment in domestic buffaloes. © 2009 Wiley Periodicals, Inc. Environ Toxicol 26: 57–67, 2011.
New fetal weight estimation models using fractional limb volume
Authors: Lee W. , Balasubramaniam M. , Deter R. L. , Yeo L. , Hassan S. S. , Gotsch F. , Kusanovic J. P. , Gonçalves L. F. , Romero R.
Published: September 2009

Objectives

The main goal of this study was to determine the accuracy and precision of new fetal weight estimation models, based on fractional limb volume and conventional two‐dimensional (2D) sonographic measurements during the second and third trimesters of pregnancy.

Methods

A prospective cross‐sectional study of 271 fetuses was performed using three‐dimensional ultrasonography to extract standard measurements—biparietal diameter (BPD), abdominal circumference (AC) and femoral diaphysis length (FDL)—plus fractional arm volume (AVol) and fractional thigh volume (TVol) within 4 days of delivery. Weighted multiple linear regression analysis was used to develop ‘modified Hadlock’ models and new models using transformed predictors that included soft tissue parameters for estimating birth weight. Estimated and observed birth weights were compared using mean percent difference (systematic weight estimation error) and the SD of the percent differences (random weight estimation error). The proportion of newborns with estimated birth weight within 5 or 10% of actual birth weight were compared using McNemar's test.

Results

Birth weights in the study group ranged from 235 to 5790 g, with equal proportions of male and female infants. Six new fetal weight estimation models were compared with the results for modified Hadlock models with sample‐specific coefficients. All the new models were very accurate, with mean percent differences that were not significantly different from zero. Model 3 (which used the natural logarithms of BPD, AC and AVol) and Model 6 (which used the natural logarithms of BPD, AC and TVol) provided the most precise weight estimations (random error = 6.6% of actual birth weight) as compared with 8.5% for the best original Hadlock model and 7.6% for a modified Hadlock model using sample‐specific coefficients. Model 5 (which used the natural logarithms of AC and TVol) classified an additional 9.1% and 8.3% of the fetuses within 5% and 10% of actual birth weight and Model 6 classified an additional 7.3% and 4.1% of infants within 5% and 10% of actual birth weight.

Conclusion

The precision of fetal weight estimation can be improved by adding fractional limb volume measurements to conventional 2D biometry. New models that consider fractional limb volume may offer novel insight into the contribution of soft tissue development to weight estimation. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
GenStat
Authors: Payne Roger W.
Published: September 2009

GenStat is a very flexible and extendable statistical system that caters for a wide range of types of use. Its MS Windows implementation has comprehensive menus to guide non‐technical users to use statistics correctly and effectively. It also has a powerful programming language that can be used to develop new techniques and facilities to make these too accessible via menus. GenStat's facilities cover all the standard statistical methods, as well as more recent techniques such as the use of the REML algorithm to model covariance structures in repeated measurements or spatial analysis and new methodology such as hierarchical generalized linear models to allow generalized linear models to be fitted in situations where there are several sources of error variation. It has powerful spreadsheet facilities for data storage and manipulation and an attractive graphics viewer that allows users to edit and interact with their plots. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Software for Computational Statistics > Software/Statistical Software
Systems approaches and algorithms for discovery of combinatorial therapies
Authors: Feala Jacob D. , Cortes Jorge , Duxbury Phillip M. , Piermarocchi Carlo , McCulloch Andrew D. , Paternostro Giovanni
Published: September 2009

Effective therapy of complex diseases requires control of highly nonlinear complex networks that remain incompletely characterized. In particular, drug intervention can be seen as control of cellular network activity. Identification of control parameters presents an extreme challenge due to the combinatorial explosion of control possibilities in combination therapy and to the incomplete knowledge of the systems biology of cells. In this review paper, we describe the main current and proposed approaches to the design of combinatorial therapies, including the heuristic methods used now by clinicians and alternative approaches suggested recently by several authors. New approaches for designing combinations arising from systems biology are described. We discuss in special detail the design of algorithms that identify optimal control parameters in cellular networks based on a quantitative characterization of control landscapes, maximizing utilization of incomplete knowledge of the state and structure of intracellular networks. The use of new technology for high‐throughput measurements is key to these new approaches to combination therapy and essential for the characterization of control landscapes and implementation of the algorithms. Combinatorial optimization in medical therapy is also compared with the combinatorial optimization of engineering and materials science and similarities and differences are delineated. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Translational, Genomic, and Systems Medicine > Therapeutic Methods
Development and implementation of an evaluation strategy for measuring conservation outcomes
Authors: Wagner Kathleen , Chessler Melissa , York Peter , Raynor Jared
Published: September 2009

The Philadelphia Zoo's Measuring Mission project assessed the conservation‐related impacts of a visit to the Zoo and documented the results in a way that would provide a set of easily actionable planning strategies. A logic model provided a theoretical framework and guided the development of survey items. Three groups were surveyed using a pre–post retrospective instrument: zoo visitors, members, and volunteers. This report includes findings from the visitor surveys only. Data were analyzed using factor analysis, correlations, and t‐tests. Results revealed that the Philadelphia Zoo has been most successful in providing its guests with a satisfying animal viewing experience, facilitated by accessible informative interpretive staff, but that guests do not always take advantage of opportunities to interact with staff. Success in achieving the Zoo's conservation mission was measured by comparing pre and posttest scores on five outcome factors (conservation motivation, conservation knowledge, pro‐conservation consumer skills, conservation attitudes/values, readiness to take conservation action). The greatest gains were found in conservation knowledge and conservation motivation. Quality of exhibits and quality of staff stand out as the most important factors in influencing conservation outcomes. To ensure that results would be accessible to a wide variety of Zoo employees for planning, program and exhibit development, and staff training, nine strategies were identified as key to achieving success in the Zoo's mission. Measuring Mission has created a process for assessing the Zoo's mission impact, and has confirmed that high‐quality exhibits interpreted by expert, readily available staff can influence conservation knowledge and motivation in particular. Zoo Biol 28:473–487, 2009. © 2009 Wiley‐Liss, Inc.
Liver transplantation for hepatocellular carcinoma: the Baylor experience
Authors: Onaca Nicholas , Klintmalm Goran B.
Published: September 2009

Background

Liver transplantation (LTX) is indicated in selected patients with hepatocellular carcinoma (HCC) and cirrhosis.

Methods

We compared the outcome of LTX for patients with and without HCC in 5‐year time periods between 1987 and 2007 to reflect the implementation of the Milan tumor selection criteria in 1997 and of the model for end‐stage liver disease (MELD) score‐based liver allocation in 2002.

Results

Of 2350 patients who underwent primary LTX, 330 had HCC. Five‐year patient survival for HCC patients was 28.6% in 1987–1992 and 42.3% in 1992–1997, which was 41.4–31.4% lower than that in non‐HCC patients (p < 0.0001). After 1997, 5‐year survival was 76% for HCC patients, similar to the survival for non‐HCC patients (p = 0.8784). Five‐year tumor recurrence dropped from 52.9% (1987–1992) and 48.2% (1992–1997) to 11.4% (1997–2002) and 8.4% (2002–2007) (p < 0.0001). Multivariate analysis for tumor recurrence showed the following significant factors: tumor size >6 cm [hazard ratio (HR) 3.67], ≥5 nodules (HR 3.441), vascular invasion (HR 3.18), transplant in 1987–1992 (HR 6.772), and transplant in 1992–1997 (HR 3.059). MELD‐based liver allocation reduced median waiting time for LTX for HCC versus non‐HCC (35 vs. 111 days;p = 0.005) without compromise in patient outcome.

Conclusions

The results of LTX for HCC continue to improve and are equal to results in patients without HCC.
Liver transplantation for hepatocellular carcinoma: Korean experience
Authors: Lee SungGyu , Ahn ChulSoo , Ha TaeYong , Moon DeokBog , Choi KunMoo , Song GiWon , Chung DongHwan , Park GilChun , Yu YoungDong , Choi NamKyu , Kim KwanWoo , Kim KiHun , Hwang Shin
Published: September 2009

Hepatocellular carcinoma (HCC) is the second most common cause of male cancer death in Korea, where the major etiology, chronic hepatitis B virus infection, is endemic. With a high incidence of unresectable HCCs and a low cadaveric organ donation rate, the number of adult living‐donor liver transplantations (LDLTs) has increased rapidly, by tenfold, over the past 10 years, as an alternative to deceased‐donor liver transplantation (DDLT) in Asia, including Korea. Currently, HCC accounts for more than 40% of the indications for adult LDLT as the associated decompensation cirrhosis or unresectable HCC with 2.8% perioperative mortality at our institute. In determining eligibility for LDLT, the Milan criteria, which have a major aim of reducing the wastage of cadaveric liver grafts, still remain the gold standard. Our published results with 168 adult LDLTs show no difference from the results with DDLT for HCC that meets the Milan criteria. However, since a substantial proportion of adult LDLT patients not fulfilling the Milan criteria have been found to survive for longer than expected, and because a live donor organ is a private gift, most LDLT programs in Korea accept HCC patients beyond the Milan criteria, and the reported 3‐year survival rates for such patients are approximately 63%. Our new proposal for expanded criteria (Asan criteria; tumor diameter ≤5 cm, number of lesions ≤6, no gross vascular invasion) in LDLT has focused on extending the number limits but keeping the maximum tumor size at 5 cm, because even modest expansion of tumor size limits beyond the Milan criteria adversely affected survival. The overall 5‐year patient survival rates were 76.3 and only 18.9% within and beyond the Asan criteria, respectively; these criteria broaden the indications for patient selection and can more accurately identify patients who will benefit from LDLT than the conventional Milan criteria and the University of California at San Francisco criteria. In Asia, where the option for DDLT is minimal or negligible, LDLT with the modest expanded selection criteria will continue to provide a chance of long‐term survival for some patients with advanced HCC.
Is 18F‐fluorodeoxyglucose positron emission tomography meaningful for estimating the efficacy of corticosteroid therapy in patients with autoimmune pancreatitis?
Authors: Shigekawa Minoru , Yamao Kenji , Sawaki Akira , Hara Kazuo , Takagi Tadayuki , Bhatia Vikram , Nishio Masami , Tamaki Tsuneo , El‐Amin Hussein , Sayed Zain EL‐Abdeen Ahmed , Mizuno Nobumasa
Published: September 2009

Background

Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic cancer (PC). Both conditions accumulate 18F‐fluorodeoxyglucose (FDG), so FDG positron emission tomography (FDG‐PET) is not discriminatory. This study aimed to evaluate the pattern of FDG accumulation, and the change in FDG uptake after steroid treatment in AIP and PC.

Methods

We compared FDG‐PET patterns between 18 patients with AIP and 20 patients with PC, and also evaluated the short‐term changes in FDG uptake after steroid therapy.

Results

FDG uptake was observed in 88.9% in AIP and 90.0% in PC. FDG uptake in extra‐abdominal lymph nodes was seen more frequently in AIP, and uptake in salivary glands, eyes and biliary ducts was seen only in AIP. Follow‐up PET was performed in 6 AIP patients and in 3 PC patients. Changes in SUVmax after steroid therapy were estimated within 1 week in 5 AIP patients and in all 3 PC patients, retrospectively. In 4 AIP patients, the change in SUVmax was more than 10%. On the other hand, in PC, SUVmax increased or remained almost unchanged (within 10%).

Conclusions

FDG‐PET pattern at baseline, and a decrease in FDG uptake after a short steroid trial can be useful for discriminating AIP from PC.
Diagnosis of glutathione synthetase deficiency in newborn screening
Authors: Simon E. , Vogel M. , Fingerhut R. , Ristoff E. , Mayatepek E. , Spiekerkötter U.
Published: September 2009

Glutathione synthetase (GSS) deficiency is a rare disorder of glutathione metabolism with varying clinical severity. Patients may present with haemolytic anaemia alone or together with acidosis and central nervous system impairment. Diagnosis is made by clinical presentation and detection of elevated concentrations of 5‐oxoproline in urine and low GSS activity in erythrocytes or cultured skin fibroblasts. Diagnosis can be confirmed by mutational analysis. Treatment consists of the correction of acidosis, blood transfusion, and supplementation with antioxidants. The most important determinants for outcome and survival in patients with GSS deficiency are early diagnosis and early initiation of treatment. The case of a newborn with GSS deficiency diagnosed by tandem mass spectrometry (MS/MS)‐based newborn screening is described. After onset of clinical symptoms on the 2nd day of life, expanded newborn screening revealed normal results for all disorders included in the German screening programme; however, selective MS/MS screening revealed a >10‐fold elevation of 5‐oxoproline in dried blood, leading to the presumptive diagnosis of GSS deficiency by the 5th day of life. Diagnosis was later confirmed by detection of markedly reduced glutathione concentration in erythrocytes and mutational analysis of the GSS gene. Presently, GSS deficiency is not included in newborn screening programmes in Europe. As outcome depends significantly on early start of treatment, routine inclusion of this disorder in newborn screening panels should be considered.