bluuebunny/crossref_metadata_2025 huggingface dataset:
Traditional coating techniques in scanning electron microscopy compared to uncoated charge compensator technology: Looking at human blood fibrin networks with the ZEISS ULTRA Plus FEG‐SEM
Authors: Pretorius Etheresia
Published: August 2010

Scanning electron microscopy (SEM) studies surface morphology. Biological material needs to be coated to render the material conductive, and gold coating is traditionally used, although other coating material like carbon and ruthenium vapors may also be used. With modern SEM technology (e.g., ZEISS ULTRA Plus FEG‐SEM), we are able to work at very low kilovolts and also view fine surface structure in much better detail than with previous older technology. Some machines also allow for the study of uncoated material, although this is usually not done with biological material. This study focuses on surface clarity by comparing gold, ruthenium vapor, and carbon coating techniques for biological material. Human fibrin networks are used as example. Uncoated specimens are also viewed with a ZEISS ULTRA Plus FEG‐SEM because of its unique nitrogen charge compensator, and here, the first micrographs for uncoated human fibrin networks versus carbon, gold, and ruthenium coating are shown. We conclude that gold coating for biological material is not preferable with the latest SEM machines, as this method forms gold islands on top of the biological material and therefore produces a false surface morphology. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Characterization of trace gases' fluctuations on a ‘low energy’ cave (Castañar de Íbor, Spain) using techniques of entropy of curves
Authors: Fernandez‐Cortes Angel , Sanchez‐Moral Sergio , Cuezva Soledad , Benavente David , Abella Rafael
Published: August 2010

Variations of carbon dioxide and radon content of cave air are presented as key parameters to assess the outgassing and isolation processes of a subterranean atmosphere. An exhaustive monitoring in the Castañar cave determined the temporal evolution of CO2 and 222Rn levels over a 12‐month period, in order to characterise the mechanisms of these microclimatic processes. Concentrations of both gases show both seasonal variations and short‐term fluctuations depending on several climatic factors: the air temperature difference between cave and exterior, cave air pressure, rainfall and anthropic factors including visits and duration of door opening. Over the course of an annual cycle, a cause‐effect analysis has been conducted by stationary clustering of time series in terms of entropy of curves. Two opposing patterns of cave microclimate have been distinguished: (1) storage of trace gases in the cave reservoir during the cold‐wet season, and (2) CO2 emissions during warm‐dry season. The partial water filling of the porous system and fissures of the membranes covering the cave (host rock and soil) is determined by the external relative humidity (controlled by the external air temperature) as well as by rainfalls, which play a key role in confining the cave atmosphere. Copyright © 2009 Royal Meteorological Society
Influence of fatty acid additives on the tribological performance of sunflower oil
Authors: Baumgart Patrick , Canzi Gabriele , Hanashiro Tory , Doezema Lambert A. , Siniawski Matthew T.
Published: August 2010

Vegetable oils are potential substitutes for petroleum‐based lubricants because they are environmentally friendly, renewable, less toxic and readily biodegradable. The addition of free fatty acids has been shown to increase the lubrication performance of vegetable oils at elevated temperatures. The purpose of this study was to evaluate the relationship between the length of the carbon chain in the fatty acid and its effectiveness as an additive for a range of elevated temperatures. Stearic, arachidic and behenic fatty acid additives were added to commercial sunflower oil. All fatty acid additives were shown to be effective in lowering the wear rate and coefficient of friction in ball‐on‐disc tribological tests. The overall carbon chain length was not observed to have a consistent influence on the effectiveness of the additive. All additives were less effective at temperatures above 100°C. Copyright © 2010 John Wiley & Sons, Ltd.
Ring‐Opening Metathesis Polymerization of Nitrile Substituted cis‐Cyclooctenes
Authors: Schneider Martin F. , Gantner Carola , Obrecht Werner , Nuyken Oskar
Published: August 2010

New nitrile‐containing polymers have been synthesized by ring‐opening metathesis polymerization of cis‐cyanocyclooct‐4‐ene and cis‐1,2‐dicyanocyclooct‐5‐ene with a 2nd generation Grubbs catalyst [(H2IMes)(PCy3)Cl2Ru = CHPh] (H2IMes = N,N′‐bis(mesityl)‐4,5‐dihydroimidazol‐2‐ylidene). With increasing content of nitrile moieties on the cyclooctene ring the reaction rates decrease from cis‐cyclooctene to cis‐cyanocyclooct‐4‐ene and cis‐1,2‐dicyanocyclooct‐5‐ene. Contrary to commercially available nitrile rubbers (unhydrogenated and hydrogenated butadiene/acrylonitrile copolymers) in which double bonds, nitrile moieties, and methylene bridges are randomly distributed along the main chain, the new polymers show a regular distribution of structural entities.

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A Novel Route to Prepare Highly Reactive and Versatile Chromatographic Monoliths
Authors: Lv Yongqin , Hughes Timothy C. , Hao Xiaojuan , Hart Noel K. , Littler Stuart W. , Zhang Xiaoqing , Tan Tianwei
Published: August 2010

The copolymer poly(isocyanatoethyl methacrylate‐co‐methyl methacrylate‐co‐ethylene glycol dimethacrylate) (poly(IEM‐co‐MMA‐co‐EGDMA)) was developed as a novel, facile, highly reactive and versatile monolithic matrix, which was amenable to surface functionalization with a variety of nucleophilic modifiers based on the reactive isocyanate group, producing monoliths of various chemistries suitable for chromatography. The specific surface area, pore size distribution, porosity and morphology of the monolithic matrix were characterized using a mercury intrusion porosimeter and scanning electron microscopy (SEM), respectively. Thermal analysis results revealed that the monolith was thermally stable up to 307 °C. The success of the chemical modification of the monolithic matrix was confirmed by FT‐IR, solid state 13C NMR and XPS elemental analysis, showing the high ligand density of the modified monoliths. A ligand density of up to 2.33 mmol·mL−1 was obtained for the 1‐octanol modified monolith (M1) with an isocyanate group conversion of 96.9%, indicating a high efficiency of the modification reaction. The potential application of the monoliths was demonstrated by the separation of a series of compounds. The novel monolithic columns exhibited high mechanical stability, column efficiency and good repeatability and reproducibility.

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Sigma receptors and their ligands in cancer biology: overview and new perspectives for cancer therapy
Authors: Megalizzi Véronique , Le Mercier Marie , Decaestecker Christine
Published: August 2010

A large number of drugs are known to bind with high affinity to sigma receptors (sigma‐Rs) and have been used in the clinic to treat mental disorders for many years. However, recent publications highlighting sigma‐R overexpression in many cancer tissues suggest potential applications for sigma‐R ligands in cancer diagnosis and therapy. The present review focuses on the involvement of sigma‐Rs in cancer biology and the potential therapeutic contributions of their pharmacologic ligands in oncology. After summarizing the current and general knowledge regarding sigma‐Rs, we detail data reported in the particular context of oncology. We then investigate the potential and specific signal transduction pathways and mechanisms involved in the actions of sigma‐R ligands in cancer biology. These processes include modulations of (1) the plasma membrane and lipid raft components, (2) intracellular calcium levels, (3) cytoskeletal protein functions, and (4) endoplasmic reticulum stress. Finally, we conclude by speculating on the roles of sigma‐R overexpression and sigma‐R ligands in cancer biology and offer perspectives on cancer therapy. © 2010 Wiley Periodicals, Inc. Med Res Rev
Research on IPv6 address configuration for wireless sensor networks
Authors: Wang Xiaonan , Gao Demin
Published: August 2010

The paper proposes an IPv6 address configuration scheme for wireless sensor networks. In the scheme, one wireless sensor network is divided into multiple clusters and the scheme creates the IPv6 address formats for the cluster heads and the cluster members respectively. Based on the proposed IPv6 address format, the scheme proposes to adopt the division method of the hash function to allocate the IPv6 addresses for the cluster heads and cluster members and to utilize linear probing to deal with assigned address collision. From the perspectives of duplicate address detection cost, address configuration cost and address configuration delay time, the paper analyzes and compares the performances of Strong DAD, MANETConf and the proposed scheme. Analytical results demonstrate the effectiveness and efficiency of the proposed scheme. Copyright © 2010 John Wiley & Sons, Ltd.
On an efficient splitting‐based method for solving the diffusion equation on a sphere
Authors: Skiba Yuri N. , Filatov Denis M.
Published: August 2010

A novel numerical approach for solving the diffusion problem on a sphere is suggested. By using operator splitting, we develop a new method that allows constructing finite difference schemes of the second and fourth approximation orders in the spatial variables. Both schemes properly ensure the balance of mass and the energy dissipation in the L2 ‐norm. The schemes are very cheap from the computational standpoint. Numerical results demonstrate the skillfulness of the approach in describing the diffusion dynamics on a sphere. It is shown the method can directly be extended to nonlinear diffusion problems.© 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 331–352, 2012
A linear system‐free Gaussian RBF method for the Gross‐Pitaevskii equation on unbounded domains
Authors: Sarra Scott A.
Published: August 2010

Gaussian radial basis function (RBF) interpolation methods are theoretically spectrally accurate. However, in applications this accuracy is seldom realized due to the necessity of solving a very poorly conditioned linear system to evaluate the methods. Recently, by using approximate cardinal functions and restricting the method to a uniformly spaced grid (or a smooth mapping thereof), it has been shown that the Gaussian RBF method can be formulated in a matrix free framework that does not involve solving a linear system [1]. In this work, we differentiate the linear system‐free Gaussian (LSFG) method and use it to solve partial differential equations on unbounded domains that have solutions that decay rapidly and that are negligible at the ends of the grid. As an application, we use the LSFG collocation method to numerically simulate Bose‐Einstein condensates. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 389–401, 2012
Nonconforming spline collocation methods in irregular domains II: Error analysis
Authors: He Yinnian , Sun Weiwei
Published: August 2010

A nonconforming spline collocation method is investigated for elliptic PDEs in an irregular region with a triangular mesh. The existence and uniqueness of the spline collocation system and the optimal H1 and L2 ‐error analysis of the numerical solution are provided. Numerical experiments are presented to confirm the theoretical analysis and show the efficiency of this method. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 441–456 2012
Adolescent group empowerment: group‐centred occupations to empower adolescents with disabilities in the urban slums of North India
Authors: Gulati Sonia , Paterson Margo , Medves Jennifer , Luce‐Kapler Rebecca
Published: August 2010

This study aimed to understand how adolescents with disabilities can assume greater control over their rehabilitation and participation within a community‐based rehabilitation programme in the urban slums of North India. A critical ethnographical approach using multiple qualitative and participatory data collection methods was adopted. Fieldwork was conducted from January to May 2005 and October 2006 to March 2007 with 21 adolescents with and 11 adolescents without disabilities (aged 12 to 18 years), and 10 community‐based rehabilitation staff members. A conceptual framework called the ‘Adolescent Group Empowerment Pyramid’ was developed. Four themes informed the framework: group participation, group demonstration, group recognition and the socio‐cultural environment's interaction with disability. Group empowerment, achieved through group‐centred occupations, encourages adolescents to work together to address their rehabilitation challenges and agendas. Three external support factors and 10 areas for nurturing the group empowerment process also emerged. A limitation of this study is the lack of data on how the familial and local political and economic environment impact adolescents' ability to make decisions about their rehabilitation. Further research might explore group occupations and occupational recognition, and what this means for social change and the personal and collective growth of adolescents in underserviced communities. Copyright © 2010 John Wiley & Sons, Ltd.
Thermal and optical properties of some phosphorus‐containing poly(1,3,4‐oxadiazole‐ester‐imide)s
Authors: Hamciuc Corneliu , Hamciuc Elena , Serbezeanu Diana , Vlad‐Bubulac Tachita
Published: August 2010

A series of phosphorus‐containing poly(1,3,4‐oxadiazole‐ester‐imide)s was prepared by polycondensation reaction of an aromatic dianhydride, namely 1,4‐[2‐(6‐oxido‐6H‐dibenz<1,2>oxaphosphorin‐6‐yl)]‐naphthalene‐bis(trimellitate)dianhydride, with different aromatic diamines containing 1,3,4‐oxadiazole ring. A solution imidization procedure was used to convert quantitatively the poly(amic acid) intermediates to the corresponding polyimides. The chemical structures of the monomers and polymers were confirmed by Fourier transform infrared, 1H NMR and 31P NMR spectroscopy. The polymers were easily soluble in polar solvents such as N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylformamide and tetrahydrofuran. They exhibited good thermal properties having the decomposition temperature above 380°C and the glass transition temperature in the range of 201–232°C. Due to the presence of phosphorus the polymers gave high char yield in termogravimetric analysis, hence good flame retardant properties. Optical properties were analyzed in solution by using UV–vis and photoluminescence spectroscopy. Solutions of the polymers in NMP exhibited photoluminescence in the blue region. Copyright © 2010 John Wiley & Sons, Ltd.
Functional membranes prepared by layer‐by‐layer assembly and its metal ions adsorption property
Authors: Jiang Yi , Wang Wen‐Cai
Published: August 2010

PVDF/(PEI‐C/PAA)n functional membranes were prepared by layer‐by‐layer (LbL) assembly, and their heavy metal ions adsorption capability was investigated. The changes in the chemical compositions of membrane surfaces were determined by X‐ray photoelectron spectroscopy (XPS). XPS results show that the surface of the PVDF membrane can be alternatively functionalized by PEI‐C and PAA. The membrane surface hydrophilicity was evaluated through water contact angle measurement. Contact angle results show that the surface hydrophilicity of the membrane surface depends on the outermost deposited layer. Morphological changes of membrane surfaces were observed by scanning electron microscopy (SEM). The water fluxes for these membranes were elevated after modification. The performances of the PVDF/(PEI‐C/PAA)n membranes on the adsorption of copper ions (Cu2+) from aqueous solutions were investigated by inductively coupled plasma (ICP). The results indicate that the PVDF/(PEI‐C/PAA)n functional membranes show high copper ions adsorption ability. Copyright © 2010 John Wiley & Sons, Ltd.
Theoretical study of neighboring carbonyl group participation in the elimination kinetics of chloroketones in the gas phase
Authors: Mora José R. , Lezama Jesús , Márquez Edgar , Escalante Luz , Córdova Tania , Chuchani Gabriel
Published: August 2010

The gas‐phase elimination of kinetics 4‐chlorobutan‐2‐one, 5‐chloropentan‐2‐one, and 4‐chloro‐1‐phenylbutan‐1‐one has been studied using electronic structure methods: B3LYP/6‐31G(d,p), B3LYP/6‐31++G(d,p), MPW91PW91/6‐31G(d,p), MPW91PW91/6‐31++G(d,p), PBEPBE/6‐31G(d,p), PBEPBE /6‐31++G(d,p), and MP2/6‐31++G(d,p). The above‐mentioned substrates produce hydrogen chloride and the corresponding unsaturated ketone. Calculation results of 4‐chlorobutan‐2‐one suggest a non‐synchronous four‐membered cyclic transition state (TS) type of mechanism. However, in the case of 5‐chloropentan‐2‐one and 4‐chloro‐1‐phenylbutan‐1‐one, the carbonyl group assists anchimerically through a polar five‐membered cyclic TS mechanism. The polarization of the CCl bond, in the sense of Cδ+…Clδ−, is a rate‐determining step in these elimination reactions. The significant increase in rates in the elimination of 5‐chloropentan‐2‐one and 4‐chloro‐1‐phenylbutan‐1‐one is attributed to neighboring group participation due to the oxygen of the carbonyl group assisting the CCl bond polarization in the TS. Copyright © 2010 John Wiley & Sons, Ltd.
Comparison of lasting life changes after cancer and BMT: perspectives of long‐term survivors and spouses
Authors: Bishop Michelle M. , Curbow Barbara A. , Springer Shauna H. , Lee Jocelyn A. , Wingard John R.
Published: August 2010

Objective: This qualitative follow up of long‐term (>5 years) cancer survivor and spouse participants from a large, previous study of quality of life after blood and marrow transplantation (BMT) was designed to gain a deeper understanding of lasting life changes they experienced.

Methods: Thirty spouse–survivor pairs, an average of 13 years post‐BMT, were individually interviewed to identify lasting life changes. Participants were asked about their most significant long‐lasting change since cancer/BMT, most significant positive change and negative change, and whether the experience had affected them and their spouse differently.

Results: Spouses and survivors spontaneously identified both positive and negative changes. Spouses reported a higher proportion of negative changes (24%) than did survivors (15%), and survivors a higher proportion of positive changes (85%) than spouses (76%). For both groups, the most frequent positive change was in ‘perspective/outlook on life’ and negative change was ‘lingering health effects,’ although survivors mentioned the latter twice as often as did spouses. Spouses were more likely to talk about changes in the first‐person plural (we, us) that were largely emotional or in relation to the survivor, whereas survivors spoke of changes in the first‐person singular (I, me) that occurred to them directly and were largely physical.

Conclusions: Although both spouses and survivors described similar negative and positive long‐lasting changes that continued an average of 13 years post‐BMT, they reported differences in the ways they were impacted by the experience, which was reflected in the language they used. Implications for future studies, family education, and couples‐based interventions are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
The contribution of self‐esteem and self‐concept in psychological distress in women at risk of hereditary breast cancer
Authors: den Heijer Mariska , Seynaeve Caroline , Vanheusden Kathleen , Duivenvoorden Hugo J. , Vos Joël , Bartels Carina C. M. , Menke‐Pluymers Marian B. E. , Tibben Aad
Published: August 2010

Objective: Clarification of the role of several aspects of self‐concept regarding psychological distress in women at risk of hereditary breast cancer will help to target counselling and psychosocial interventions more appropriately. In this study, we aimed (1) to examine the role of general self‐esteem and specific aspects of self‐concept (i.e. stigma, vulnerability, and mastery) in psychological distress in women at risk of hereditary breast cancer and (2) to compare the relative importance of these self‐concept aspects in psychological distress in women with low versus high self‐esteem.

Methods: General and breast‐cancer‐specific distress, self‐esteem, self‐concept, and demographics were assessed in 246 women being at risk of hereditary breast cancer, who opted either for regular breast surveillance or prophylactic surgery.

Results: In the total study group, self‐esteem was negatively associated with general distress. Furthermore, feeling stigmatized was strongly associated with more breast‐cancer‐specific distress, and to a lesser degree with general distress. In women with low‐self esteem, feelings of stigmatization were strongly associated with higher levels of both breast–cancer‐specific and general distress, while a sense of mastery was associated with less general distress. For women with high self‐esteem, feelings of both stigmatization and vulnerability were associated with more breast‐cancer‐specific distress, whereas there were no significant associations with general distress.

Discussion: Psychosocial interventions or support groups for women at risk of hereditary breast cancer should focus on self‐esteem and feelings of stigmatization and isolation, and consequently tailor the interventions on specific items for respective women. Copyright © 2010 John Wiley & Sons, Ltd.
Thermal regime of a thermokarst lake and its influence on permafrost, Beiluhe Basin, Qinghai‐Tibet Plateau
Authors: Lin Zhanju , Niu Fujun , Xu Zhiying , Xu Jian , Wang Ping
Published: August 2010

A typical 2‐m deep thermokarst lake was studied in the Beiluhe Basin on the Qinghai‐Tibet Plateau. Lakeshore retrogression, water temperatures, and ground temperatures beneath and around the lake were monitored. About 80 per cent of the lakeshore edge collapsed each year with a maximum rate of about 1.8 m from August 2007 to October 2008. The warm season was the main period of shoreline collapse, especially from August to October. Ice forms in the lake towards the end of October and reaches its maximum thickness of about 0.7 m by the end of the cold season. The thaw depth at the lakeshore edge is about 0.7 m greater than in the adjacent terrain, while any pre‐existing permafrost below its centre has thawed entirely. Overall, the high degree of disturbance associated with the thermokarst lake is shown by mean annual ground temperatures beneath it that are more than 5°C higher than in the surrounding terrain at the same depth. Copyright © 2010 John Wiley & Sons, Ltd.
Successful diagnosis and treatment of congenital tracheal web using a fiberoptic bronchoscope
Authors: Yin Yong , Zhang Lei
Published: August 2010

Congenital tracheal web is a very rare abnormality that often manifests as wheezing, dyspnea, and respiratory failure. Misdiagnosis is common. Here we describe the case of a 47‐day‐old female infant who presented after severe, extended coughing. The diagnosis of congenital tracheal web was made following coronal computer tomography (CT) reconstruction and bronchoscopy. The bronchoscope was used to facilitate tracheal expansion. This is the youngest case reported to date to highlight the diagnosis and treatment of a 47 days infant with congenital tracheal web. An infant with tracheal web, a very rare congenital anomaly can be clearly diagnosed by coronal CT reconstruction combined with bronchoscopy. If diagnosed early, the bronchoscope may be used to facilitate tracheal expansion. Pediatr. Pulmonol. 2010; 45:945–947. © 2010 Wiley‐Liss, Inc.
Integrated biophysical studies implicate partial unfolding of NBD1 of CFTR in the molecular pathogenesis of F508del cystic fibrosis
Authors: Wang Chi , Protasevich Irina , Yang Zhengrong , Seehausen Derek , Skalak Timothy , Zhao Xun , Atwell Shane , Spencer Emtage J. , Wetmore Diana R. , Brouillette Christie G. , Hunt John F.
Published: August 2010

The lethal genetic disease cystic fibrosis is caused predominantly by in‐frame deletion of phenylalanine 508 in the cystic fibrosis transmembrane conductance regulator (CFTR). F508 is located in the first nucleotide‐binding domain (NBD1) of CFTR, which functions as an ATP‐gated chloride channel on the cell surface. The F508del mutation blocks CFTR export to the surface due to aberrant retention in the endoplasmic reticulum. While it was assumed that F508del interferes with NBD1 folding, biophysical studies of purified NBD1 have given conflicting results concerning the mutation's influence on domain folding and stability. We have conducted isothermal (this paper) and thermal (accompanying paper) denaturation studies of human NBD1 using a variety of biophysical techniques, including simultaneous circular dichroism, intrinsic fluorescence, and static light‐scattering measurements. These studies show that, in the absence of ATP, NBD1 unfolds via two sequential conformational transitions. The first, which is strongly influenced by F508del, involves partial unfolding and leads to aggregation accompanied by an increase in tryptophan fluorescence. The second, which is not significantly influenced by F508del, involves full unfolding of NBD1. Mg‐ATP binding delays the first transition, thereby offsetting the effect of F508del on domain stability. Evidence suggests that the initial partial unfolding transition is partially responsible for the poor in vitro solubility of human NBD1. Second‐site mutations that increase the solubility of isolated F508del‐NBD1 in vitro and suppress the trafficking defect of intact F508del‐CFTR in vivo also stabilize the protein against this transition, supporting the hypothesize that it is responsible for the pathological trafficking of F508del‐CFTR.
Sample size determination in clinical trials with multiple co‐primary binary endpoints
Authors: Sozu Takashi , Sugimoto Tomoyuki , Hamasaki Toshimitsu
Published: August 2010

Clinical trials often employ two or more primary efficacy endpoints. One of the major problems in such trials is how to determine a sample size suitable for multiple co‐primary correlated endpoints. We provide fundamental formulae for the calculation of power and sample size in order to achieve statistical significance for all the multiple primary endpoints given as binary variables. On the basis of three association measures among primary endpoints, we discuss five methods of power and sample size calculation: the asymptotic normal method with and without continuity correction, the arcsine method with and without continuity correction, and Fisher's exact method. For all five methods, the achieved sample size decreases as the value of association measure increases when the effect sizes among endpoints are approximately equal. In particular, a high positive association has a greater effect on the decrease in the sample size. On the other hand, such a relationship is not very strong when the effect sizes are different. Copyright © 2010 John Wiley & Sons, Ltd.
Covariate adjusted weighted normal spatial scan statistics with applications to study geographic clustering of obesity and lung cancer mortality in the United States
Authors: Huang Lan , Tiwari Ram C. , Pickle Linda W. , Zou Zhaohui
Published: August 2010

In the field of cluster detection, a weighted normal model‐based scan statistic was recently developed to analyze regional continuous data and to evaluate the clustering pattern of pre‐defined cells (such as state, county, tract, school, hospital) that include many individuals. The continuous measures of interest are, for example, the survival rate, mortality rate, length of physical activity, or the obesity measure, namely, body mass index, at the cell level with an uncertainty measure for each cell. In this paper, we extend the method to search for clusters of the cells after adjusting for single/multiple categorical/continuous covariates. We apply the proposed method to 1999–2003 obesity data in the United States (US) collected by CDC's Behavioral Risk Factor Surveillance System with adjustment for age and race, and to 1999–2003 lung cancer age‐adjusted mortality data by gender in the United States from the Surveillance Epidemiology and End Results (SEER Program) with adjustment for smoking and income. Copyright © 2010 John Wiley & Sons, Ltd.
Proteomic Analysis of Sox2-Associated Proteins During Early Stages of Mouse Embryonic Stem Cell Differentiation Identifies Sox21 as a Novel Regulator of Stem Cell Fate
Authors: Mallanna Sunil K. , Ormsbee Briana D. , Iacovino Michelina , Gilmore Joshua M. , Cox Jesse L. , Kyba Michael , Washburn Michael P. , Rizzino Angie
Published: August 2010

Small increases in the levels of master regulators, such as Sox2, in embryonic stem cells (ESC) have been shown to promote their differentiation. However, the mechanism by which Sox2 controls the fate of ESC is poorly understood. In this study, we employed multidimensional protein identification technology and identified >60 nuclear proteins that associate with Sox2 early during ESC differentiation. Gene ontology analysis of Sox2-associated proteins indicates that they participate in a wide range of processes. Equally important, a significant number of the Sox2-associated proteins identified in this study have been shown previously to interact with Oct4, Nanog, Sall4, and Essrb. Moreover, we examined the impact of manipulating the expression of a Sox2-associated protein on the fate of ESC. Using ESC engineered for inducible expression of Sox21, we show that ectopic expression of Sox21 in ESC induces their differentiation into specific cell types, including those that express markers representative of neurectoderm and heart development. Collectively, these studies provide new insights into the range of molecular processes through which Sox2 is likely to influence the fate of ESC and provide further support for the conclusion that the expression of Sox proteins in ESC must be precisely regulated. Importantly, our studies also argue that Sox2, along with other pluripotency-associated transcription factors, is woven into highly interconnected regulatory networks that function at several levels to control the fate of ESC.
Channel status prediction for cognitive radio networks
Authors: Tumuluru Vamsi Krishna , Wang Ping , Niyato Dusit
Published: August 2010

The cognitive radio (CR) technology appears as an attractive solution to effectively allocate the radio spectrum among the licensed and unlicensed users. With the CR technology the unlicensed users take the responsibility of dynamically sensing and accessing any unused channels (frequency bands) in the spectrum allocated to the licensed users. As spectrum sensing consumes considerable energy, predictive methods for inferring the availability of spectrum holes can reduce energy consumption of the unlicensed users to only sense those channels which are predicted to be idle. Prediction‐based channel sensing also helps to improve the spectrum utilization (SU) for the unlicensed users. In this paper, we demonstrate the advantages of channel status prediction to the spectrum sensing operation in terms of improving the SU and saving the sensing energy. We design the channel status predictor using two different adaptive schemes, i.e., a neural network based on multilayer perceptron (MLP) and the hidden Markov model (HMM). The advantage of the proposed channel status prediction schemes is that these schemes do not requirea prioriknowledge of the statistics of channel usage. Performance analysis of the two channel status prediction schemes is performed and the accuracy of the two prediction schemes is investigated. Copyright © 2010 John Wiley & Sons, Ltd.
Robust tracking algorithm for wireless sensor networks based on improved particle filter
Authors: Wang Jie , Gao Qinghua , Wang Hongyu , Chen Hongyang , Jin Minglu
Published: August 2010

Benefitting from its ability to estimate the target state's posterior probability density function (PDF) in complex nonlinear and non‐Gaussian circumstance, particle filter (PF) is widely used to solve the target tracking problem in wireless sensor networks. However, the traditional PF algorithm based on sequential importance sampling with re‐sampling will degenerate if the latest observation appear in the tail of the prior PDF or if the observation likelihood is too peaked in comparison with the prior. In this paper, we propose an improved particle filter which makes full use of the latest observation in constructing the proposal distribution. Thequality prediction functionis proposed to measure the quality of the particles, and only the high quality particles are selected and used to generate the coarse proposal distribution. Then, acentroid shift vectoris calculated based on the coarse proposal distribution, which leads the particles move towards the optimal proposal distribution. Simulation results demonstrate the robustness of the proposed algorithm under the challenging background conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Isomerization of 9c11t/10t12c CLA in Triacylglycerols
Authors: Christy Alfred A.
Published: August 2010

Isomers of conjugated linoleic acid from 7t9c through 12t14t can be induced by thermal treatment of triacylglycerol samples of 9c11t or 10t12c fatty acids in glass tubes. The formation of conjugated linoleic acids (CLAs) has been observed during thermal induction of the above‐mentioned triacylglycerols at 250, 280 and 320°C. The concentrations of isomers formed in the mixture varied depending on the temperature and duration of the heating experiments. The objective of this study was to find a suitable thermal induction temperature and time that can produce most of the isomers of CLAs from the above‐mentioned triacylglycerols. Such a mixture would give researchers a reference standard that can be used in the identification of CLAs in GC analyses of relevant samples. Fifteen‐microlitre portions of the triacylglycerol samples containing 9c11t/10t12c fatty acid were placed in micro‐glass ampoules, sealed under nitrogen and then subjected to thermal treatment. The glass ampoules were removed at regular time intervals, cut open, and part of the samples was analysed by infrared spectroscopy using attenuated internal reflectance technique. The remainder of the samples was subjected to derivatisation into their methyl esters. The methyl esters of the isomerised fatty acids were then analysed by gas chromatography after appropriate dilution in heptane. The results show that the thermally induced glyceride samples of 9c11t/10t12c fatty acids gave CLA profiles containing isomers ranging from 7t9c to 12t14t. However, the concentrations of the isomers are different depending on the duration of the thermal induction. It appears that [1,5] sigmatropic rearrangements and positional isomerisations take place in the heated mixtures. The rearrangements and positional isomerisations are accelerated by increasing temperature. The glyceride samples heated to 325°C form isomers within 30 min and provide a mixture of CLA isomers that can be used as reference sample containing the methyl esters of CLAs.
Étale groupoids as germ groupoids and their base extensions
Authors: Matsnev Dmitry , Resende Pedro
Published: August 2010

We introduce the notion of wide representation of an inverse semigroup and prove that with a suitably defined topology there is a space of germs of such a representation that has the structure of an étale groupoid. This gives an elegant description of Paterson's universal groupoid and of the translation groupoid of Skandalis, Tu and Yu. In addition, we characterize the inverse semigroups that arise from groupoids, leading to a precise bijection between the class of étale groupoids and the class of complete and infinitely distributive inverse monoids equipped with suitable representations, and we explain the sense in which quantales and localic groupoids carry a generalization of this correspondence.
Bounds for modified Bessel functions of the first and second kinds
Authors: Baricz Árpád
Published: August 2010

Some new inequalities for quotients of modified Bessel functions of the first and second kinds are deduced. Moreover, some developments on bounds for modified Bessel functions of the first and second kinds, higher-order monotonicity properties of these functions and applications to a special function that arises in finite elasticity, are summarized. The key tool in our proofs is a frequently used criterion for the monotonicity of the quotient of two Maclaurin series.
Optimization-based formation of autonomous mobile robots
Authors: Zhang Huan , Pathirana Pubudu N.
Published: August 2010

The formation of autonomous mobile robots to an arbitrary geometric pattern in a distributed fashion is a fundamental problem in formation control. This paper presents a new asynchronous, memoryless (oblivious) algorithm to the formation problem via distributed optimization techniques. The optimization minimizes an appropriately defined difference function between the current robot distribution and the target geometric pattern. The optimization processes are performed independently by individual robots in their local coordinate systems. A movement strategy derived from the results of the distributed optimizations guarantees that every movement makes the current robot configuration approaches the target geometric pattern until the final pattern is reached.
Human capability of discriminating relief-like 2D figures in tactile displaying
Authors: Ohka Masahiro , Yoshino Hiroki , Miyaoka Tetsu
Published: August 2010

To enhance tactile display capability, we performed a series of experiments based on psychophysics in which we adopted a circle and eight kinds of ovals as stimuli of the convex line (hereafter tactile image). The circle's diameter is 10 mm, the minor axes of the eight ovals are decreased in 3% steps from the circles, and each major axis is adjusted so that the area of each oval equals the circle area. Human subjects judged which stimuli (presented on the left or the right tactile images) equal the circle. The experiment was conducted on both the finger pads and the thenar parts to compare their experimental sensitivity ratios with the sensitivity ratio estimated on the basis of mechanoreceptor density. The discrimination sensitivity for the thenar part is inferior to that for the finger pad in terms of the low density of the mechanoreceptor in the thenar part. The tactile image was mainly recognized by a slowly adaptive type I unit, but the first adaptive type II unit was not affected by specimen cooling due to discrimination precision. Subsequently, discrimination sensitivity was not different between the free and restricted haptic motions. Since this result implies that the tactile image is modified by a motor signal for the haptic motion to prevent blurring of the tactile image, perhaps the motion movement in the tactile display is changed based on the design convenience.
Multiphoton Flow Cytometry to Assess Intrinsic and Extrinsic Fluorescence in Cellular Aggregates: Applications to Stem Cells
Authors: Buschke David G. , Squirrell Jayne M. , Ansari Hidayath , Smith Michael A. , Rueden Curtis T. , Williams Justin C. , Lyons Gary E. , Kamp Timothy J. , Eliceiri Kevin W. , Ogle Brenda M.
Published: August 2010

Detection and tracking of stem cell state are difficult due to insufficient means for rapidly screening cell state in a noninvasive manner. This challenge is compounded when stem cells are cultured in aggregates or three-dimensional (3D) constructs because living cells in this form are difficult to analyze without disrupting cellular contacts. Multiphoton laser scanning microscopy is uniquely suited to analyze 3D structures due to the broad tunability of excitation sources, deep sectioning capacity, and minimal phototoxicity but is throughput limited. A novel multiphoton fluorescence excitation flow cytometry (MPFC) instrument could be used to accurately probe cells in the interior of multicell aggregates or tissue constructs in an enhanced-throughput manner and measure corresponding fluorescent properties. By exciting endogenous fluorophores as intrinsic biomarkers or exciting extrinsic reporter molecules, the properties of cells in aggregates can be understood while the viable cellular aggregates are maintained. Here we introduce a first generation MPFC system and show appropriate speed and accuracy of image capture and measured fluorescence intensity, including intrinsic fluorescence intensity. Thus, this novel instrument enables rapid characterization of stem cells and corresponding aggregates in a noninvasive manner and could dramatically transform how stem cells are studied in the laboratory and utilized in the clinic.
On endoscopy and the refined Gross–Prasad conjecture for (SO5, SO4)
Authors: Gan Wee Teck , Ichino Atsushi
Published: August 2010

We prove an explicit formula for periods of certain automorphic forms on SO5× SO4along the diagonal subgroup SO4in terms ofL-values. Our formula also involves a quantity from the theory of endoscopy, as predicted by the refined Gross–Prasad conjecture.
A p-adic analogue of the Borel regulator and the Bloch–Kato exponential map
Authors: Huber Annette , Kings Guido
Published: August 2010

In this paper we define a p-adic analogue of the Borel regulator for the K-theory of p-adic fields. The van Est isomorphism in the construction of the classical Borel regulator is replaced by the Lazard isomorphism. The main result relates this p-adic regulator to the Bloch–Kato exponential and the Soulé regulator. On the way we give a new description of the Lazard isomorphism for certain formal groups. We also show that the Soulé regulator is induced by continuous and even analytic classes.
Azimuthal plasma flow in the Kronian magnetosphere
Authors: Müller A. L. , Saur J. , Krupp N. , Roussos E. , Mauk B. H. , Rymer A. M. , Mitchell D. G. , Krimigis S. M.
Published: August 2010

We study the azimuthal plasma velocity in Saturn's magnetosphere between 3 and 13 Saturn radii (Rs) by analyzing energetic particle injection events using data of the Magnetospheric Imaging Instrument (MIMI) onboard the Cassini spacecraft in orbit around Saturn. Due to the magnetic drifts, the injected particles at various energies begin to disperse and leave an imprint in the electron as well as in the ion energy spectrograms of the MIMI instrument. The shape of these profiles strongly depends on the azimuthal velocity distribution of the magnetospheric plasma and the age of the injection event. Comparison of theoretically computed dispersion profiles with observed ones enables us to characterize the azimuthal flow of the plasma. The measured flow profile clearly shows that the plasma subcorotates with velocities as low as 80% of full corotation at radial distances between 8 Rs to 13 Rs. With knowledge of the flow profile and the ages of each injection event we can calculate the location where the energetic particles were injected into the inner magnetosphere. The night and morning sector of the Kronian magnetosphere are preferred regions for the generation of hot plasma injections.
Magnetic and optical properties of airborne dust and settling rates of dust at the Phoenix landing site
Authors: Drube L. , Leer K. , Goetz W. , Gunnlaugsson H. P. , Haspang M. P. , Lauritsen N. , Madsen M. B. , Sørensen L. K. D. , Ellehoj M. D. , Lemmon M. T. , Morris R. V. , Blaney D. , Reynolds R. O. , Smith P. H.
Published: August 2010

The Magnetic Properties Experiment (referred to as iSweep or Caltarget) onboard the Phoenix lander was executed in the arctic region of Mars during the mission's 152 sols lifetime. The iSweep experiment involved periodic multispectral imaging of a series of permanent ring magnets. It was designed to attract airborne magnetic dust particles to certain areas on the iSweeps thereby sorting all settling airborne particles at least to some degree according to their magnetic properties. The dust on the area directly above the strong magnets of the iSweep was found to be brighter than that collected on the precursor Sweep Magnet Experiment onboard the Mars Exploration Rovers near Mars' equator, and also this dust is found to be brighter than both surface soil near the lander and soil in the region surrounding the lander. As most other dust and soils on Mars, the Phoenix dust lacks strong spectral signatures of highly crystalline phases. For the first time, based on the complete calibrated data set of images of the iSweeps, spectra were extracted of the putative dust falling on the magnetically protected areas of the iSweeps. These areas are accessible only for particles with a magnetic susceptibility below 10−3. Spectra of this nonmagnetic dust are interpreted as signals from nonmagnetic minerals such as tectosilicates or glasses pigmented by poorly crystalline ferric oxides. Rates of dust settling were determined to be 1.08 μm/sol on the magnets and 0.06 μm/sol for the magnetically protected areas.
Blocking Moving Window algorithm: Conditioning multiple‐point simulations to hydrogeological data
Authors: Alcolea Andres , Renard Philippe
Published: August 2010

Connectivity constraints and measurements of state variables contain valuable information on aquifer architecture. Multiple‐point (MP) geostatistics allow one to simulate aquifer architectures, presenting a predefined degree of global connectivity. In this context, connectivity data are often disregarded. The conditioning to state variables is usually carried out by minimizing a suitable objective function (i.e., solving an inverse problem). However, the discontinuous nature of lithofacies distributions and of the corresponding objective function discourages the use of traditional sensitivity‐based inversion techniques. This work presents the Blocking Moving Window algorithm (BMW), aimed at overcoming these limitations by conditioning MP simulations to hydrogeological data such as connectivity and heads. The BMW evolves iteratively until convergence: (1) MP simulation of lithofacies from geological/geophysical data and connectivity constraints, where only a random portion of the domain is simulated at every iteration (i.e., the blocking moving window, whose size is user‐defined); (2) population of hydraulic properties at the intrafacies; (3) simulation of state variables; and (4) acceptance or rejection of the MP simulation depending on the quality of the fit of measured state variables. The outcome is a stack of MP simulations that (1) resemble a prior geological model depicted by a training image, (2) honor lithological data and connectivity constraints, (3) correlate with geophysical data, and (4) fit available measurements of state variables well. We analyze the performance of the algorithm on a 2‐D synthetic example. Results show that (1) the size of the blocking moving window controls the behavior of the BMW, (2) conditioning to state variable data enhances dramatically the initial simulation (which accounts for geological/geophysical data only), and (3) connectivity constraints speed up the convergence but do not enhance the stack if the number of iterations is large.