bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of a Bioactive Coating on Resorbable, Neodymium Containing Magnesium Alloys, and Analyses of their Effects on the In Vitro Degradation Behavior in a Simulated Body Fluid
Authors: Seitz Jan‐Marten , Bormann Ulrike , Collier Kelly , Wulf Eric , Eifler Rainer , Bach Friedrich Wilhelm
Published: February 2012

Whilst bioactive coatings are commonly used as layers for non‐resorbable implant materials, such as titanium or steel to improve cell adhesion, this study investigates the application of bioactive SiO2–CaO–P2O5 on resorbable magnesium alloys (Nd2 and LANd442). The bioactive coating was applied to the magnesium alloys by a dip‐coating process, where a parameter set of 20 immersions and a 10 s drying time between each immersion generated a reproducible layer with regard to its thickness and homogeneity. In vitro mass loss, strength loss, and pH value measurements were used to determine the coating's effects on the degradation behavior in a simulated body fluid. Here, it could be observed that bioactive layers on magnesium alloys lead to an increased degradation in comparison to specimens in the uncoated states. In addition to this, pitting corrosion was determined for bioactive coated magnesium samples during comparatively early periods of the investigation. Due to the decreased corrosion resistance and induced pitting corrosion of bioactive coated magnesium alloys, it is suggested that one carefully tests if the enhanced cell adhesion, which occurs with bioactive coatings, warrants the increased degradation of magnesium based implant materials.
Reversible Switch Memory Effect in Hydrogen‐Terminated Ultrananocrystalline Diamond
Authors: Tordjman Moshe , Bolker Asaf , Saguy Cecile , Baskin Emanuel , Bruno Paola , Gruen Dieter M. , Kalish Rafi
Published: February 2012

Innovative memory switch devices require reliable bistable conductance properties. It would be desirable if such bistable characteristics were available in robust solid state materials, such as diamond, which benefit from outstanding physical properties. A bistable current with reversible switching effect from surface transfer doped ultrananocrystalline diamond thin films measured by electron field emission is reported. This switching is manifested by the appearance of huge jumps in the current emission, up to four orders of magnitude, that occur at specific extracting electric field values. Persistent hysteresis is exhibited whenever the field is ramped down. It is proposed that these phenomena are the result of resonant‐tunneling through a double barrier junction composed of tetrahedral amorphous carbon (ta‐C)/nanodiamond/adsorbent/vacuum. This finding may pave the way for the realization of novel types of memory switch devices with unprecedented performance.
Preparation and characterization of a series of novel EuIII‐complex‐polyurethane acrylate materials based on mixed 6‐hydroxy‐1‐naphthoate and 1,10‐phenanthroline ligands
Authors: Fang Shao‐Ming , Wang Cong , Hu Min , Wang Pei‐Yuan , Zhou Li‐Ming , Gao Li‐Jun , Liu Chun‐Sen
Published: February 2012

Hydroxyl groups in the coordination complex {[Eu(L)3(phen)]·H2O}2 (L = 6‐hydroxy‐1‐naphthoate and phen = 1,10‐phenanthroline) were used to react with NCO functional groups of isophorone diisocyanate in the presence of dibutyltin dilaurate. A series of new luminescent EuIII‐complex‐polyurethane acrylate materials, poly(EuIII‐complex‐polyurethane methacrylate (PUA complex)), were prepared through in situ polymerization of polyurethane acrylate macromonomers and the resulting material was characterized by X‐ray diffraction, IR spectra, thermogravimetry analysis, dynamic mechanical analysis, and fluorescence spectroscopy. The result indicates that both EuIII complex and PUA complex can emit characteristic fluorescence of EuIII ion. Moreover, the emission intensity was enhanced under the same experiment condition when the content of EuIII complex in the PUA complex was increased. In addition, we have not found the fluorescence quenching in this work even the content of EuIII complex was increased to 5 wt %. Such rare‐earth complex‐polyurethane acrylate hybrid materials are suitable for the photoluminescent applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Was heißt “lebendig”?
Authors: Penzlin Heinz
Published: February 2012

“Leben” heißt “Lebendigsein” von bestimmten Wesenheiten, die wir kurz als “Lebe‐Wesen” bezeichnen. Physikalisch gesehen sind Lebewesen offene Systeme, da sie einen intensiven Stoff‐ und Energieaustausch mit ihrer Umgebung unterhalten. Sie erhalten einen quasi‐stationären Zustand fernab vom thermodynamischen Gleichgewicht aktiv, d. h. unter Energieeinsatz, und selbsttätig gegen die ständig gegenwärtigen Kräfte des Verfalls aufrecht. Dieser dynamische Zustand der Lebewesen unterscheidet sich von allem, was wir in der anorganischen Natur vorfinden, indem er eine interne funktionelle Ordnung oder “Organisation” repräsentiert. Die mit ihm verbundenen Vorgänge sind so aufeinander abgestimmt und ausgerichtet, dass sie in ihrer Gesamtheit den Zusammenbruch des lebendigen Zustandes autonom verhindern. Das erfordert nicht nur einen intensiven Energie‐ und Stoffumsatz, sondern auch einen intensiven Informationstransfer. Organismen sind durch ihren Besitz an Nukleinsäuren als Speicher und Quelle spezifischer Informationen, die ihnen erlauben, ihre interne Organisation über die Zeit selbsttätig aufrecht zu erhalten, einzigartig in der Natur. Sie und nur sie sind im wahren Sinne des Wortes “selbst‐organisierend”.
Konvergente Evolution der Beutefangmechanismen bei Meeresquallen und Schwarmfischen
Authors: Kutschera Ulrich
Published: February 2012

Entfernt verwandte Arten, die im selben Habitat leben, können im Verlauf der Stammesentwicklung ähnliche Körpermerkmale herausbilden. So sind beispielsweise die Flügel von Insekten, Vögeln und Fledermäusen die Resultate einer derartigen konvergenten Evolution. Nun wurde auch ein Beispiel für die Konvergenz eines physiologischen Merkmals entdeckt: Quallen und Schwarmfische erbeuten Kleinstlebewesen trotz unterschiedlicher Mechanismen mit gleicher Rate und Aufwand an Stoffwechselenergie.
Lynn Margulis: Symbiogenesis‐Theorie und Anti‐Darwinismus
Authors: Kutschera Ulrich
Published: February 2012

Die Tatsache, dass kernhaltige Zellen (Eucyten) zu Organellen reduzierte Bakterien enthalten – wie beispielsweise Mitochondrien und Chloroplasten – und somit durch Kooperation und Integration entstanden sind, wurde von der Biologin Lynn Margulis mit entdeckt. Die Symbiogenese war ein Schlüsselereignis in der organismischen Evolution. Doch nicht alle Konzepte der Evolutionsbiologin Lynn Margulis sind so unumstritten, wie es die Endosymbiontentheorie heute ist – einige ihrer Gedanken werden ausgesprochen kontrovers diskutiert.
Validation of Submodels for CFD Simulation of n‐Hexane Pool Flames including Interferometry
Authors: Schälike Stefan , Wehrstedt Klaus‐Dieter , Gawlowski Markus , Schönbucher Axel
Published: February 2012

Computational fluid dynamics simulation is used to predict transient and time‐averaged flame temperatures and species concentrations of an n‐hexane pool flame. Employing a combination of an assumed probability density function approach with laminar flamelets using detailed kinetic data and large eddy simulation with Smagorinsky submodel is shown to be a promising way in modeling pool and tank fires. The measured species concentration and flame temperature profiles from gas chromatography, thermocouple measurements and holographic interferometry are used to validate the submodels for CFD simulation of pool flames.
Reconstruction of cell lineage and spatiotemporal pattern formation of the mesoderm in the amphipod crustacean Orchestia cavimana
Authors: Hunnekuhl Vera S. , Wolff Carsten
Published: February 2012

Background: Cell lineage studies in amphipods have revealed an early restriction of blastomere fate. The mesendodermal cell lineage is specified with the third cleavage of the egg. We took advantage of this stereotyped mode of development by fluorescently labeling the mesodermal precursors in embryos of Orchestia cavimana and followed the morphogenesis of the mesodermal cell layer through embryonic development. Results: The mesoderm of the trunk segments is formed by a very regular and stereotypic cell division pattern of the mesoteloblasts and their segmental daughters. The head mesoderm in contrast is generated by cell movements and divisions out of a mesendodermal cell mass. Our reconstructions reveal the presence of three different domains within the trunk mesoderm of the later embryo. We distinguish a cell group median to the limbs, a major central population from which the limb mesoderm arises and a dorsolateral branch of mesodermal cells. Conclusions: Our detailed description of mesodermal development relates different precursor cell groups to distinct muscle groups of the embryo. A dorsoventral subdivision of mesoderm is prepatterned within the longitudinal mesodermal columns of the germ‐band stage. This makes amphipods excellent crustacean models for studying mesodermal differentiation on a cellular and molecular level. Developmental Dynamics 241:697–717, 2012. © 2012 Wiley Periodicals, Inc.
FoxO1 is required in endothelial but not myocardial cell lineages during cardiovascular development
Authors: Sengupta Arunima , Chakraborty Santanu , Paik Jihye , Yutzey Katherine E. , Evans‐Anderson Heather J.
Published: February 2012

Background: The forkhead transcription factor FoxO1 is involved in cell cycle regulation during cardiovascular development. Systemic loss of FoxO1 results in lethality at embryonic day 10.5 with severe cardiovascular defects; however, the cell‐type‐specific requirements for FoxO1 in cardiovascular development are unknown. Here we examine the role of FoxO1 using a conditional loss of function approach. Results: Loss of FoxO1 in differentiated cardiac myocytes has no apparent effect on cardiovascular development. In contrast, endothelial‐specific FoxO1 deficiency in Tie2Cre;FoxO1fl/fl embryos results in lethality at E10.5, which recapitulates the FoxO1‐null phenotype. Tie2Cre;FoxO1fl/fl embryos have an intact differentiated endothelium, but display defective remodeling of vasculature. Additional effects on heart development include reduced myocardial trabeculation, which is likely secondary to the endothelial abnormalities, and hypoplasia of endocardial cushions. Conclusions: The phenotype of Tie2Cre;FoxO1fl/fl mutant embryos demonstrates that FoxO1 is required specifically in endothelial cells to regulate formation of the heart and vasculature during development. Developmental Dynamics 241:803–813, 2012. © 2012 Wiley Periodicals, Inc.
Reversal of diabetes by βTC3 cells encapsulated in alginate beads generated by emulsion and internal gelation
Authors: Hoesli Corinne A. , Kiang Roger L. J. , Mocinecová Dušana , Speck Madeleine , Mošková Daniela Jochec , Donald‐Hague Christine , Lacík Igor , Kieffer Timothy J. , Piret James M.
Published: February 2012

Encapsulation of insulin‐producing cells in alginate beads could improve the treatment of type 1 diabetes by reducing or eliminating the need for immunosuppression. We have recently adapted an emulsion and internal gelation process to β‐cell encapsulation. This process has the advantages of being well suited for m3/h production rates and allowing the use of increased alginate concentrations. Compared with 1.5% alginate beads generated by a standard extrusion process, 5% alginate emulsion‐generated beads demonstrated greater in vitro stability and greater volumetric exclusion of antibody‐sized pullulan. When βTC3 cells were transplanted into streptozotocin‐induced allogeneic diabetic mice, a significant decrease in the blood glucose levels was seen within 2 days with the 5% emulsion‐generated beads but not until >16 days with the 1.5% extrusion‐generated beads. This was correlated with higher cell survival and lower graft‐specific plasma immunoglobulin levels. These results suggest that higher‐concentration alginate beads generated by emulsion and internal gelation have improved graft immunoprotection. The emulsion process is a promising and scalable technology for cellular therapies requiring immune isolation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Prescription for innovation at Holy Family Memorial: Make big progress by thinking small
Authors: Novicoff Wendy M. , McMeans Scott
Published: February 2012

Facing the challenges of an industry undergoing reform, Holy Family Memorial, a health‐care network based in Manitowoc, Wisconsin, focused its improvement efforts on a series of small‐scale projects to address issues ranging from patient care and support to paperwork. By involving all stakeholders in decision making and shaping the organizational culture in the process, it has managed to adhere to the principles of its faith‐based mission while ensuring patient safety, enhancing customer service, facilitating organizational communications, and gaining a net marginal change exceeding $17 million over the last three years. © 2012 Wiley Periodicals, Inc.
Finite element simulations of the behavior of piled‐raft foundations using a multiphase model
Authors: Bourgeois Emmanuel , Hassen Ghazi , de Buhan Patrick
Published: February 2012

Finite element simulations of the behavior of a piled raft foundation have been carried out using a multiphase model conceived as an improved homogenization approach. According to this model, the ground reinforced by a group of piles is treated as a homogeneous continuous medium. In this approach, no specific interface elements are necessary to account for the mechanical interaction between the piles and the ground: this interaction is described by means of two scalar parameters, one stiffness parameter and one which can easily be derived from the maximum ground‐pile friction. The implementation of the model into a finite element code provides an efficient tool for the analysis of the influence of the pile number or length on the settlement and bearing capacity of a square piled raft foundation and of the way the total applied load is shared between the raft and the piles. Results are compared with a standard 3D finite element analysis. The comparison highlights the fact that the proposed approach remains to be improved to account for tip resistance. Copyright © 2012 John Wiley & Sons, Ltd.
Suppression of alcohol dependence using high‐dose baclofen: a self‐case report
Authors: Thomas Phillip E
Published: February 2012

In this self‐case report, Dr Thomas describes how his own alcohol dependence and the severe chronic anxiety at the root of it were both successfully suppressed by taking high‐dose baclofen. Copyright © 2012 John Wiley & Sons, Ltd.
Styrene–vinyl pyridine diblock copolymers: Synthesis by RAFT polymerization and self‐assembly in solution and in the bulk
Authors: Zamfir Mirela , Patrickios Costas S. , Montagne Franck , Abetz Clarissa , Abetz Volker , Oss‐Ronen Liat , Talmon Yeshayahu
Published: February 2012

Reversible addition‐fragmentation chain transfer (RAFT) polymerization along with benzyl dithiobenzoate chain transfer agent was employed for the controlled preparation of four diblock copolymers of styrene (St, less polar monomer) and 2‐ or 4‐vinyl pyridine (2VP or 4VP, more polar monomers): St161‐b‐2VP48, St161‐b‐2VP121, St161‐b‐4VP76, and St161‐b‐4VP107, where the subscripts indicate the experimentally determined degrees of polymerization for each block. These diblock copolymers and their common St homopolymer precursor were characterized in terms of their molecular weights and compositions using gel permeation chromatography and 1H NMR spectroscopy, respectively. All four diblock copolymers self‐assembled in dilute toluene solutions to form reverse spherical micelles, which were characterized using atomic force microscopy and cryogenic transmission electron microscopy. Both microscopy techniques revealed that the 4VP‐bearing diblock copolymers formed larger micelles than the 2VP‐bearing ones, a result of the greater 4VP‐toluene incompatibility as compared to the 2VP‐toluene one. Finally, films cast from chloroform solutions of the diblocks were investigated in terms of their bulk morphologies using transmission electron microscopy. While the 2VP‐containing block copolymer self‐assembled into a spherical morphology, the 4VP‐containing one with comparable composition and molecular weight formed a cylindrical structure, manifesting the greater 4VP‐St incompatibility as compared to that of the 2VP‐St pair. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Nasal versus oronasal raised volume forced expirations in infants—A real physiologic challenge
Authors: Morris Mohy G.
Published: February 2012

Raised volume rapid thoracoabdominal compression (RTC) generates forced expiration (FE) in infants typically from an airway opening pressure of 30 cm H2O (V30). We hypothesized that the higher nasal than pulmonary airway resistance limits forced expiratory flows (FEF%) during (nasal) FEn, which an opened mouth, (oronasal) FEo, would resolve. Measurements were performed during a brief post‐hyperventilation apnea on 12 healthy infants aged 6.9–104 weeks. In two infants, forced expiratory (FEFV) flow volume (FV) curves were generated using a facemask that covered the nose and a closed mouth, then again with a larger mask with the mouth opened. In other infants (n = 10), the mouth closed spontaneously during FE. Oronasal passive expiration from V30 generated either the inspiratory capacity (IC) or by activating RTC before end‐expiration, the slow vital capacity (jSVC). Peak flow (PF), FEF25, FEF50, FEF25‐75, FEV0.4, and FEV0.5 were lower via FEn than FEo (P < 0.05), but the ratio of expired volume at PF and forced vital capacity (FVC) as percent was higher (P < 0.05). FEF75, FEF85, FEF90, FVC as well as the applied jacket pressures were not different (P > 0.05). FEFV curves generated via FEo exhibited higher PF than FV curves of IC (P < 0.05); PF of those produced via FEn were not different from FV curves of IC (P > 0.05) but lower than those of jSVC (P < 0.05). In conclusion, the higher nasal than pulmonary airways resistance unequivocally affects the FEFV curves by consistently reducing PF and decreases mid‐expiratory flows. A monitored slightly opened mouth and a gentle anterior jaw thrust are physiologically integral for raised volume RTC in order to maximize the oral and minimize nasal airways contribution to FE so that flow limitation would be in the pulmonary not nasal airways. Pediatr Pulmonol. 2012. 47:780–794. © 2012 Wiley Periodicals, Inc.
Intrathoracic airway obstruction and gastroesophageal reflux: A canine model
Authors: Bhatia R. , Pagala M. , Vaynblat M. , Marcus M. , Kazachkov M.
Published: February 2012

Introduction

Gastroesophageal reflux (GER) is common in children with airway disorders. Previous studies have shown an association between upper airway obstruction and GER in experimental animal models. However, the cause and effect relationship between intrathoracic airway obstruction (IAO) and GER is obscure. The goal of this study is to investigate the association between IAO and GER using the canine model.

Methods

In sedated dogs, a telemetric implant was placed subcutaneously (with one pressure sensor tip each in intrapleural space and abdomen) to monitor intrapleural pressure (IPP) and intrabdominal pressure (IAP). The IPP and the IAP were monitored intraoperatively and in conscious dogs on the 7th to 10th postoperative days. GER was assessed by determining the reflux index (RI), based on the intraesophageal pH recording performed continuously for a 24 hr period using a pH probe. After 2–3 weeks following placement of the telemetric implant, IAO was surgically created in the dog. After maintaining IAO for 2 weeks, the IPP, IAP, and pH measurements were monitored again following the same protocol as before IAO.

Results

After the creation of IAO, there was no significant change observed in the mean RI either in the distal (P = 0.716) or proximal (P = 0.962) esophageal lumens. The IPP became significantly more negative (P = 0.006) and the IAP turned significantly negative (P < 0.001) from being positive compared to the respective values before IAO. However, transdiaphragmatic pressure (Pdi) did not change significantly (P = 0.08).

Conclusion

We conclude that moderate IAO does not cause GER in our animal model. It can be explained by the absence of significant change in Pdi after creation of IAO. Pediatr Pulmonol. 2012. 47:1097–1102. © 2012 Wiley Periodicals, Inc.
Continuous integrated distal capnography in infants ventilated with high frequency ventilation
Authors: Kugelman Amir , Riskin Arieh , Shoris Irit , Ronen Michal , Stein Iris Shalev , Bader David
Published: February 2012

Objective

To assess within a feasibility study the correlation, agreement, and trending of continuous integrated distal capnography (dCap) with PaCO2 in infants on HFV.

Study design

Sixteen premature infants [median (range) gestational age: 26.5 (24.7–34.7) weeks], ventilated with HFV (mean ± SD airway pressure: 8.1 ± 2.1 cmH2O, FiO2: 0.39 ± 0.21) for RDS, intubated with a double‐lumen endotracheal‐tube and whose data were recorded on a bedside computer participated in the study. Side‐stream dCap was measured via the extra‐port of a double‐lumen endotracheal‐tube by a Microstream capnograph, with a specially designed software for HFV and compared with simultaneous PaCO2. Integrated time‐window analysis of the data was performed retrospectively on data collected prospectively.

Results

Analysis included 195 measurements. The correlation of dCap with PaCO2 (r = 0.68, P < 0.0001) and the agreement (bias ± precision: −2.0 ± 10.7 mmHg) were adequate. Area under the ROC curves for dCap to detect high (>60 mmHg) or low (<35 mmHg) PaCO2 was 0.79 (CI: 0.70–0.89) and 0.87 (CI: 0.73–1.00), respectively; P < 0.0001. Changes in dCap and in PaCO2 for consecutive measurements within each patient were adequately correlated (r = 0.65, P < 0.0001).

Conclusions

Continuous integrated dCap is feasible in premature infants ventilated with HFV and can be helpful for trends and alarm for unsafe levels of PaCO2. Pediatr Pulmonol. 2012. 47:876–883. © 2012 Wiley Periodicals, Inc.
Strain relaxation in thick ($1{\bar {1}}01$) InGaN grown on GaN/Si substrate
Authors: Tanikawa Tomoyuki , Honda Yoshio , Yamaguchi Masahito , Amano Hiroshi , Sawaki Nobuhiko
Published: February 2012

We demonstrated the growth of thick InGaN on ($1{\bar {1}}01$) GaN/Si. The InGaN layer showed a marked inclination along the 〈0001〉 projection direction. The InGaN with a higher indium composition showed a larger inclination. Owing to the lattice mismatch between InGaN and GaN, misfit dislocations and/or stacking faults are generated from the heterointerface, which resulted in a larger inclination. As the indium content increased, inclining was observed in the early stage of InGaN growth. After InGaN was substantially relaxed, the crystallinity was saturated or improved. The surface morphology also became roughened because of the strain relaxation to form triangular grains, and then recovered following the coalescence.
Asymptotic properties of mean survival estimate based on the Kaplan–Meier curve with an extrapolated tail
Authors: Gong Qi , Fang Liang
Published: February 2012

Asymptotic distribution of the mean survival time based on the Kaplan–Meier curve with an extrapolated ‘tail’ is derived. A closed formula of the variance estimate is provided. Asymptotic properties of the estimator were studied in a simulation study, which showed that this estimator was unbiased with proper coverage probability and followed a normal distribution. An example is used to demonstrate the application of this estimator. Copyright © 2012 John Wiley & Sons, Ltd.
A Strong Electronic Coupling between Graphene Nanosheets and Layered Titanate Nanoplates: A Soft‐Chemical Route to Highly Porous Nanocomposites with Improved Photocatalytic Activity
Authors: Kim In Young , Lee Jang Mee , Kim Tae Woo , Kim Hyo Na , Kim Hyoung‐il , Choi Wonyong , Hwang Seong‐Ju
Published: February 2012

Strongly coupled nanocomposites of layered titanate and reduced graphene oxide (RGO) are synthesized by electrostatically derived self‐assembly between negatively charged RGO nanosheets and positively charged TiO2 nanosols, which is then followed by a phase transition of the anatase TiO2 component into layered titanate. The resulting nanocomposite consists of thin 2D nanoplates of lepidocrocite‐type layered titanate immobilized on the surface of RGO nanosheets. The composite formation with RGO nanosheets is effective not only in promoting the phase transition of anatase TiO2 nanosols, but also in improving the thermal stability of the layered titanate, indicating the role of RGO nanosheets as an agent for directing and stabilizing layered structures. The layered‐titanate−RGO nanocomposites exhibit remarkably expanded surface area with the formation of micropores and mesopores. The composite formation with RGO nanosheets gives rise to the disappearance of the reflectance edge of layered titanate in the diffuse reflectance UV−vis spectra, indicating a strong electronic coupling between the RGO and layered titanate. The strong electronic correlation between the two components is further evidenced by the visible‐light‐induced generation of photocurrents after the hybridization with RGO. The layered‐titanate−RGO nanocomposite shows a higher activity for the photodegradation of organic molecules than uncomposited layered titanate, underscoring the usefulness of graphene hybridization in improving the photocatalyst performance of layered titanate. The experimental findings presented here clearly demonstrate that the self‐assembly of metal oxide nanoparticles with RGO 2D nanosheets is quite effective not only in synthesizing porous metal‐oxide−graphene nanocomposites with improved photo‐induced functionality, but also in achieving strong electronic coupling between RGO and metal oxides.
Kinetic analysis of dynamic positron emission tomography data using open‐source image processing and statistical inference tools
Authors: Hawe David , Hernández Fernández Francisco R. , O'Suilleabháin Liam , Huang Jian , Wolsztynski Eric , O'Sullivan Finbarr
Published: February 2012

In dynamic mode, positron emission tomography (PET) can be used to track the evolution of injected radio‐labelled molecules in living tissue. This is a powerful diagnostic imaging technique that provides a unique opportunity to probe the status of healthy and pathological tissue by examining how it processes substrates. The spatial aspect of PET is well established in the computational statistics literature. This article focuses on its temporal aspect. The interpretation of PET time‐course data is complicated because the measured signal is a combination of vascular delivery and tissue retention effects. If the arterial time‐course is known, the tissue time‐course can typically be expressed in terms of a linear convolution between the arterial time‐course and the tissue residue. In statistical terms, the residue function is essentially a survival function—a familiar life‐time data construct. Kinetic analysis of PET data is concerned with estimation of the residue and associated functionals such as flow, flux, volume of distribution, and transit time summaries. This review emphasizes a nonparametric approach to the estimation of the residue based on a piecewise linear form. Rapid implementation of this by quadratic programming is described. The approach provides a reference for statistical assessment of widely used one‐ and two‐ compartmental model forms. We illustrate the method with data from two of the most well‐established PET radiotracers, 15O‐H2O and 18F‐fluorodeoxyglucose, used for assessment of blood perfusion and glucose metabolism, respectively. The presentation illustrates the use of two open‐source tools, AMIDE and R, for PET scan manipulation and model inference. WIREs Comput Stat 2012, 4:316–322. doi: 10.1002/wics.1196

This article is categorized under:

Applications of Computational Statistics > Health and Medical Data/Informatics

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods

Applications of Computational Statistics > Signal and Image Processing and Coding
Imprinted DNA methylation reprogramming during early mouse embryogenesis at the Gpr1‐Zdbf2 locus is linked to long cis‐intergenic transcription
Authors: Kobayashi Hisato , Sakurai Takayuki , Sato Shun , Nakabayashi Kazuhiko , Hata Kenichiro , Kono Tomohiro
Published: February 2012

The paternally‐expressed imprinted genes Gpr1 and Zdbf2 form a gene cluster wherein the imprinted‐methylated regions of these two genes differ. We identified a novel, paternally expressed, long intergenic non‐coding Zdbf2 variant (Zdbf2linc) transcribed from maternally methylated Gpr1 DMR during early embryogenesis in the mouse. While the Gpr1 DMR displayed biallelic hypermethylation, Zdbf2linc expression was rarely observed in the post‐gastrulation, despite a positive correlation between the methylation of Zdbf2 DMRs and the mono‐allelic transcription of the original Zdbf2 coding variant. Furthermore, lack of the maternal methylation imprint resulted in the biallelic expression of both coding and non‐coding Zdbf2 transcripts as well as complete methylation of Zdbf2 DMRs. Globally, our findings suggest the role of Zdbf2linc in the establishment of secondary epigenetic modifications after implantation.
The future of the modal split in China’s greenest city: Assessing options for integrating Dalian’s fragmented public transport system
Authors: Mu Rui , de Jong Martin , Yu Bin , Yang Zhongzhen
Published: February 2012

Dalian used to have a very favorable modal split (for public transport) and had the honor of being an environmentally friendly city among its peers in China only a few years ago. However, momentous and when it comes to sustainability rather deleterious is evolving in the past five years or so: automobiles have flooded the city along with car-friendly policies being promulgated at both the central and local levels of government. Consequently, the market share of public transport has been substantially eroded since then. Apart from the rapid motorization that weakened Dalian’s position as a green city, another factor fueling the downward trend of transit attractiveness has been the growing fragmentation in transit services. Given the fact that the motorization process is irreversible and restricting car purchase and use is unlikely to work out in China, if something needs to be done to maintain Dalian as a clean and comfortable living habitat, then lifting the fragmentation in the transit system is the only way to do this. Therefore, this paper explores where the fragmentation originates, and how it can be counteracted. A mathematical model is thus built to test the effectiveness of reducing fragmentation in improving transit service. And the results show that the modal split after system integration is going to tilt more strongly towards transit, while for service quality levels for users cannot expect much improvement. These modeling results have significant implications for the future public transport administration in Dalian.
URBAN TRANSFORMATION IN LIVERPOOL AND MANCHESTER, 1918–1939
Authors: WILDMAN CHARLOTTE
Published: February 2012

Liverpool and Manchester have come to typify twentieth-century urban decay and their demise is strongly associated with the perceived decline of local government after 1918. By the 1930s, contemporaries had stereotyped northern cities as places of poverty and deprivation, in comparison to the prosperous south. The divide was reinforced by economic historians who focused on regional variations in unemployment and economic depression. This article challenges stereotypical images of interwar Liverpool and Manchester by illustrating the ambitious programmes of urban redevelopment implemented by their Corporations in response to political and economic instability. Grandiose projects such as the Wythenshawe Estate, Mersey Tunnel and Manchester Central Library aimed to stimulate employment and to boost local economies and morale. Redevelopment was promoted heavily to present new images of Liverpool and Manchester. Crucially, urban transformation was marketed as a way to communicate with the newly enfranchised, classless citizen and suggests similarities with broader strategies employed by the Conservative party to engage with the mass electorate. The level of ambition and innovation demonstrates that local municipal culture thrived and Liverpool (with close American links) is shown to have been at the forefront of innovations in civic design and urban planning.
SECULARIZATION AND MODERNIZATION: THE FAILURE OF A ‘GRAND NARRATIVE’
Authors: CLARK J. C. D.
Published: February 2012

This historiographical review offers a critical reconsideration of a central component of modernization theory: the model of secularization devised within the sociology of religion, and especially the version sustained by sociologists in the UK. It compares that model with the results of historical research in a range of themes and periods, and suggests that those results are now often radically inconsistent with this sociological orthodoxy. It concludes that an older historical scenario which located in the early modern period the beginnings of a ‘process’ of secularization that achieved its natural completion in the nineteenth or twentieth centuries is finally untenable, and it proposes a broader, more historical conception of ‘religion’ able to accommodate both persistent religiosity and undoubted changes in religious behaviour.
Plasma diagnostics for complex plasmas under microgravity and on ground
Authors: PUSTYLNIK MIKHAIL Y. , THOMA MARKUS H. , MORFIŁL GREGOR E. , GRIMM RAINER , HOCK CHRISTIAN
Published: February 2012

Complex plasmas are low-temperature plasmas containing micron-sized particles (microparticles) such as dust grains. These are present in astrophysical systems (comets, molecular clouds, et al.) and in technological applications (microchip production by plasma etching, deposition of solar cells, et al.). Complex plasmas are also of interest in basic science because these are often used as models for many other strongly coupled many-body systems in solid state, fluid, or plasma physics. Since gravity has a strong influence on the microparticle component, experiments under microgravity (parabolic flights, sounding rockets, International Space Station (ISS)) are performed. Interaction between microparticles depends on plasma parameters such as ion density or ion temperature. Also, the presence of microparticles may change the properties of background plasma. Therefore, the background plasma needs to be characterized to provide adequate interpretation of the microgravity experiments. For this purpose a dedicated high-speed diagnostic system has been set up.
Biophysics of mitosis
Authors: McIntosh J. Richard , Molodtsov Maxim I. , Ataullakhanov Fazly I.
Published: February 2012

Mitosis is the process by which eukaryotic cells organize and segregate their chromosomes in preparation for cell division. It is accomplished by a cellular machine composed largely of microtubules (MTs) and their associated proteins. This article reviews literature on mitosis from a biophysical point of view, drawing attention to the assembly and motility processes required to do this complex job with precision. Work from both the recent and the older literature is integrated into a description of relevant biological events and the experiments that probe their mechanisms. Theoretical work on specific subprocesses is also reviewed. Our goal is to provide a document that will expose biophysicists to the fascination of this quite amazing process and provide them with a good background from which they can pursue their own research interests in the subject.
Gender in Italian–German bilinguals: A comparison with German L2 learners of Italian
Authors: BIANCHI GIULIA
Published: February 2012

This study compares mastery of gender assignment and agreement in Italian by adult Italian–German bilinguals who have acquired two languages simultaneously (2L1), and by adult German highly proficient second language learners (L2ers) of Italian. Our data show that incompleteness in bilingual acquisition and in second language (L2) acquisition primarily affects gender assignment: the categorization of nouns and the interpretablegenderfeature are subject to vulnerability in the two modalities of acquisition. Overall, mastery of morpho-syntax (i.e., gender agreement) was nearly native-like for both groups of speakers, suggesting that uninterpretable features are unlikely to be subject to vulnerability in the heritage language of adult bilingual speakers and can be acquired in adult L2 acquisition. Deviances from the target in gender assignment and, to a lesser extent, in gender agreement are attributed to both language-internal (i.e., language) and language-external factors (i.e., amount of input).
Geodetic constraints on San Francisco Bay Area fault slip rates and potential seismogenic asperities on the partially creeping Hayward fault
Authors: Evans Eileen L. , Loveless John P. , Meade Brendan J.
Published: February 2012

The Hayward fault in the San Francisco Bay Area (SFBA) is sometimes considered unusual among continental faults for exhibiting significant aseismic creep during the interseismic phase of the seismic cycle while also generating sufficient elastic strain to produce major earthquakes. Imaging the spatial variation in interseismic fault creep on the Hayward fault is complicated because of the interseismic strain accumulation associated with nearby faults in the SFBA, where the relative motion between the Pacific plate and the Sierra block is partitioned across closely spaced subparallel faults. To estimate spatially variable creep on the Hayward fault, we interpret geodetic observations with a three‐dimensional kinematically consistent block model of the SFBA fault system. Resolution tests reveal that creep rate variations with a length scale of <15 km are poorly resolved below 7 km depth. In addition, creep at depth may be sensitive to assumptions about the kinematic consistency of fault slip rate models. Differential microplate motions result in a slip rate of 6.7 ± 0.8 mm/yr on the Hayward fault, and we image along‐strike variations in slip deficit rate at ∼15 km length scales shallower than 7 km depth. Similar to previous studies, we identify a strongly coupled asperity with a slip deficit rate of up to 4 mm/yr on the central Hayward fault that is spatially correlated with the mapped surface trace of the 1868MW = 6.9–7.0 Hayward earthquake and adjacent to gabbroic fault surfaces.
Role of individual phosphorylation sites for the 14-3-3-protein-dependent activation of yeast neutral trehalase Nth1
Authors: Veisova Dana , Macakova Eva , Rezabkova Lenka , Sulc Miroslav , Vacha Petr , Sychrova Hana , Obsil Tomas , Obsilova Veronika
Published: February 2012

Trehalases are important highly conserved enzymes found in a wide variety of organisms and are responsible for the hydrolysis of trehalose that serves as a carbon and energy source as well as a universal stress protectant. Emerging evidence indicates that the enzymatic activity of the neutral trehalase Nth1 in yeast is enhanced by 14-3-3 protein binding in a phosphorylation-dependent manner through an unknown mechanism. In the present study, we investigated in detail the interaction between Saccharomyces cerevisiae Nth1 and 14-3-3 protein isoforms Bmh1 and Bmh2. We determined four residues that are phosphorylated by PKA (protein kinase A) in vitro within the disordered N-terminal segment of Nth1. Sedimentation analysis and enzyme kinetics measurements show that both yeast 14-3-3 isoforms form a stable complex with phosphorylated Nth1 and significantly enhance its enzymatic activity. The 14-3-3-dependent activation of Nth1 is significantly more potent compared with Ca2+-dependent activation. Limited proteolysis confirmed that the 14-3-3 proteins interact with the N-terminal segment of Nth1 where all phosphorylation sites are located. Site-directed mutagenesis in conjunction with the enzyme activity measurements in vitro and the activation studies of mutant forms in vivo suggest that Ser60 and Ser83 are sites primarily responsible for PKA-dependent and 14-3-3-mediated activation of Nth1.
IL-17/IL-17 receptor system in autoimmune disease: mechanisms and therapeutic potential
Authors: Zhu Shu , Qian Youcun
Published: February 2012

IL-17 (interleukin-17), a hallmark cytokine of Th17 (T-helper 17) cells, plays critical roles in host defence against bacterial and fungal infections, as well as in the pathogenesis of autoimmune diseases. The present review focuses on current knowledge of the regulation, functional mechanisms and targeting strategies of IL-17 in the context of inflammatory autoimmune diseases. Evidence shows that IL-17 is highly up-regulated at sites of inflammatory tissues of autoimmune diseases and amplifies the inflammation through synergy with other cytokines, such as TNF (tumour necrosis factor) α. Although IL-17 was originally thought to be produced mainly by Th17 cells, a newly defined T-cell subset with a specific differentiation programme and tight regulation, several other cell types (especially innate immune cells) are also found as important sources for IL-17 production. Although IL-17 activates common downstream signalling, including NF-κB (nuclear factor κB), MAPKs (mitogen-activated protein kinases), C/EBPs (CCAAT/enhancer-binding proteins) and mRNA stability, the immediate receptor signalling has been shown to be quite unique and tightly regulated. Mouse genetic studies have demonstrated a critical role for IL-17 in the pathogenesis of variety of inflammatory autoimmune diseases, such as RA (rheumatoid arthritis) and MS (multiple sclerosis). Importantly, promising results have been shown in initial clinical trials of monoclonal antibodies against IL-17 or its receptor (IL-17R) to block IL-17-mediated function in treating autoimmune patients with psoriasis, RA and MS. Therefore targeting IL-17/IL-17R, IL-17-producing pathways or IL-17-mediated signalling pathways can be considered for future therapy in autoimmune diseases.
Falls Among Older Adults: A Public Health Concern
Authors: Handelsman Jaynee
Published: February 2012

The risk of falling increases with advancing age, and falls in older adults are associated with immediate serious consequences, such as fractures and head injuries, as well as longer-term problems, such as disability, fear of falling, and loss of independence. The determination of fall risk among older adults and the prevention of falls have been a major focus of research for more than a decade. A number of factors have been identified that increase the likelihood that an individual will fall, and various strategies for assessing falls risk have been reported. Some have proposed clinically based assessment tools that can be easily included as part of an annual exam, whereas others have proposed laboratory based comprehensive evaluations. Regardless of the type of falls assessment strategy, the desired outcome is to provide interventions that may result in a reduction in falls risk. The purpose of this paper is to provide a brief review of the magnitude of the problem, factors that are known to be associated with an increased risk of falls, components that may be included in a fall prevention program, and evidence of factors that contribute to improved outcomes.
Podcasts, Google, and YouTube—Oh My! An Innovative Online Course for University Students on Preventing Hearing Loss
Authors: Blood Ingrid M. , Blood Gordon W.
Published: February 2012

Although hearing conservation programs have been developed and assessed for young children, military and civilian personnel, employees, and other groups, few studies have reported on ways to assist college-age students to learn about and protect their hearing. In this paper, we discuss the rationale, development, analysis, and outcome of a web-based, general education course at a large research university in the Northeast. The study analyzed annual student comments and evaluations of 2,745 individuals who had successfully completed the course from 2003 through 2011. Consistent, positive ratings using a seven-point scale (1 = lowest to 7 = highest) were obtained: the highest ratings of 6 or 7 were selected by 86% of respondents for content, 93% for overall learning experience, and 90% for online learning experience. Results suggested that college-age students can learn new knowledge and skills about hearing, hearing loss, and the negative impact of noise across the lifespan. Quantitative and qualitative data suggested that an innovative online teaching/learning experience that meets university degree requirements may help student learners develop healthy hearing practices necessary for a lifetime.
Effects of substrate on structure and the magnetic properties of (001)-textured FePt films grown at low temperature
Authors: Zhang A. M. , Chen Z. X. , Zou W. Q. , Lv B. , Ge J. J. , Cai H. L. , Du J. , Wu X. S. , Zhang S. J. , Zhou S. M.
Published: February 2012

(001)-oriented FePt films are deposited, by magnetron sputtering at 300 °C, on LaAlO3 (001), SrTiO3 (001), and MgO (001) single crystal substrates. The tetragonal distortion, magnetic anisotropy, and the coercive force of the films vary with the substrate. The ordering process is very different with the substrate, which may affect the magnetic properties of the film. The magnetic coercivity decreases with increasing the ordering parameter and the tetragonal distortion, which may be ascribed to the lattice strain.
FCH domain only-2 organizes clathrin-coated structures and interacts with Disabled-2 for low-density lipoprotein receptor endocytosis
Authors: Mulkearns Erin E. , Cooper Jonathan A.
Published: February 2012

Clathrin-mediated endocytosis regulates the internalization of many nutrient and signaling receptors. Clathrin and endocytic accessory proteins are recruited to receptors by specific adaptors. The adaptor Disabled-2 (Dab2) recruits its cargoes, including the low-density lipoprotein receptor (LDLR), and mediates endocytosis, even when the major adaptor protein AP2 is depleted. We hypothesized that the accessory proteins normally recruited by AP2 may be recruited by Dab2 if AP2 is absent. We identified one such accessory protein, the F-BAR protein FCH domain only-2 (FCHO2), as a major Dab2-interacting protein. The μ-homology domain (μHD) of FCHO2 binds directly to DPF sequences in Dab2 that also bind AP2. Disrupting the Dab2-FCHO2 interaction inhibited Dab2-mediated LDLR endocytosis in AP2-depleted cells. Depleting FCHO2 reduced the number but increased the size of clathrin structures on the adherent surface of HeLa cells and inhibited LDLR and transferrin receptor clustering. However, LDLR was internalized efficiently by FCHO2-deficient cells when additional time was provided for LDLR to enter the enlarged structures before budding, suggesting that later steps of endocytosis are normal under these conditions. These results indicate FCHO2 regulates the size of clathrin structures, and its interaction with Dab2 is needed for LDLR endocytosis under conditions of low AP2.
Modeling Agricultural Supply Response Using Mathematical Programming and Crop Mixes
Authors: Chen Xiaoguang , Önal Hayri
Published: February 2012

Mathematical programming models are widely used in agricultural sector analysis. However, the lack of micro‐level data, as well as computational requirements, necessitate the aggregation of individual producers into representative units when working at the sectoral level. This usually leads to unrealistic extreme specialization in supply responses. In 1982, McCarl introduced the “historical crop mixes” approach to avoid extreme specialization. We extend this approach by generating additional synthetic crop mixes using supply response elasticities and systematically varied commodity prices. In addition to avoiding extreme specialization, this approach provides flexibility when future supply responses can be vastly different from past responses. An application to U.S. biofuel policy analysis is presented.