bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunomodulatory efficacy of nisin—a bacterial lantibiotic peptide
Authors: Begde D. , Bundale S. , Mashitha P. , Rudra J. , Nashikkar N. , Upadhyay A. 
Published: February 2011

AbstractNisin is a peptide bacteriocin, grouped under the category of lantibiotics. It is naturally produced by Lactococcus lactis to eliminate other competing gram‐positive bacteria from its vicinity. Moreover under certain conditions it is reported to be effective against a broad range of gram‐negative bacteria as well. Thus, it has been widely used as a safe food preservative especially in the dairy industry. Because of its wide‐scale consumption, its effect on eukaryotic cells should be of great concern. Here we examine the immunomodulatory efficacy of nisin in vitro. MTT‐based cytotoxicity assay demonstrated nisin's cytotoxicity on human T‐cell lymphoma Jurkat cells, Molt‐4 cells and freshly cultured human lymphocytes at over 200 µM concentration (IC50225 µM). The cell death mechanism induced by nisin in all these lymphocyte types was independent of oligonucleosomal DNA fragmentation, as analyzed by agarose gel electrophoresis and comet assay. Additionally, scanning electron microscope and fluorescence microscopy demonstrated the ability of nisin to activate human PMNs in vitro. Nisin‐activated neutrophils extruded intact nuclear chromatin to form NETs, well known for neutralization of virulence factors and extermination of bacterial pathogens. Nisin's presence also elevated neutrophil intracellular superoxide levels, normally produced by activated NADPH oxidase and prerequisite to NET formation. These nisin‐induced responses in cellular representatives of two separate branches of human immune system—adaptive and innate—although leading to cell death, did not include DNA fragmentation. From these findings, we propose that nisin might trigger similar AICD mechanisms in lymphocytes and neutrophils, different from conventional apoptosis which involves DNA fragmentation. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Growth and characterization of Er‐doped ZnO elongated nanostructures
Authors: Ryu Y. K. , Fernández P. , Piqueras J. 
Published: February 2011

AbstractEr‐doped ZnO nano‐ and microstructures have been grown by thermal treating of compacted mixtures of ZnO and Er2O3 powders and their optical properties have been studied by cathodoluminescence (CL). Annealing the pressed samples leads to the growth of nanoneedles and nanoneedle networks, as well as rods. CL measurements enable detection of the dopant incorporation into these structures as well as the influence of this incorporation on the defect structure. CL contrast reveals an inhomogeneous distribution of luminescent centers, showing differences in the Er incorporation degree as a function of morphology and structures of the rods. Spectral distribution of the luminescence also points toward a nonhomogeneous distribution of the dopant. The growth of hierarchical structures has also been studied.
The early history of hygrometry, and the controversy between De Saussure and De Luc
Authors: Middleton W. E. Knowles 
Published: February 2011

AbstractAn account of the early development of hygrometers and hygrometry is presented from the time of Leonardo da Vinci up to about the year 1800. The famous controversy between J. A. de Luc and H. B. de Saussure, in the last two decades of the 18th century, is described in so far as it refers to hygrometry.
Piperazines for peptide carboxyl group derivatization: effect of derivatization reagents and properties of peptides on signal enhancement in matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Qiao Xiaoqiang , Sun Liangliang , Chen Lingfan , Zhou Yuan , Yang Kaiguang , Liang Zhen , Zhang Lihua , Zhang Yukui 
Published: February 2011

AbstractPiperazine‐based derivatives, including 1‐(2‐pyridyl)piperazine (2‐PP), 1‐(2‐pyrimidyl)piperazine (2‐PMP), 1‐(4‐pyridyl)piperazine (4‐PP), and 1‐(1‐methyl‐4‐piperidinyl)piperazine (M‐PP), were used for the derivatization of carboxyl groups on peptides with 1‐(3‐dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride (EDC) and 1‐hydroxy‐7‐azabenzotriazole (HOAt) as coupling reagents, and trifluoroacetic acid (TFA) as activator. Taking synthetic peptides RVYVHPI (RI‐7) and APGDRIYVHPF (AF‐11) as samples, the yields of derivatized peptides by 2‐PP, 2‐PMP and 4‐PP were higher than 94%. The effect of piperazine derivatives on the signals of tryptic digests of α‐transferrin and bovine serum albumin (BSA) was investigated, and it was found that peptides derivatized by 2‐PP and 2‐PMP exhibited obviously improved ionization efficiency. Furthermore, comparison of identified peptides before and after derivatization showed that peptides with low molecular weight (MW) and high pI value were preferably detected after derivatization. In addition, after derivatization with 2‐PP and 2‐PMP, protein myelin basic protein S, 20 kDa protein, and histone H were confidently identified from the tryptic digests of two fractions of rat brain protein separated by reversed‐phase high‐performance liquid chromatography (HPLC), indicating the potential application of 2‐PP and 2‐PMP for the highly sensitive determination of peptides in comprehensive proteome analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative profiling of SiGe/Si superlattices by time‐of‐flight secondary ion mass spectrometry: the advantages of the extended Full Spectrum protocol
Authors: Py M. , Barnes J. P. , Lafond D. , Hartmann J. M. 
Published: February 2011

AbstractThe abundance of work on SiGe‐based devices demonstrates the importance of the compositional characterization of such materials. However, Secondary Ion Mass Spectrometry (SIMS) characterization of SiGe layers often suffers from matrix effects due to the non‐linear variation of ionization yields with Ge content. Several solutions have been proposed in order to overcome this problem, each having its own limitations such as a restricted germanium concentration range, or a weak sensitivity to dopants or impurities. Here, we studied the improvements brought by an alternative protocol: the extended Full Spectrum protocol, which states proportionality between the composition of the secondary ion beam and that of the actual material. Previous studies on this protocol showed that it was extremely precise and reproducible for Ge quantification in a permanent regime, because of minimized matrix effects.In this study we thus investigated its accuracy for the simultaneous quantitative depth profiling of both matrix elements (Si, Ge) and impurities (B, C or P) in strained SiGe/Si superlattices by comparing results with those from more classic protocols. The profiles provided by the extended Full Spectrum protocol were found to be accurate, and to exhibit better properties than classic protocols in terms of signal/noise ratio and signal stability, along with a slight enhancement in depth resolution. Copyright © 2011 John Wiley & Sons, Ltd.
Kobuviruses – a comprehensive review
Authors: Reuter Gábor , Boros Ákos , Pankovics Péter 
Published: February 2011

AbstractKobuviruses are members of the large and growing family Picornaviridae. Until now, two official, Aichi virus and Bovine kobuvirus, and one candidate kobuvirus species, ‘porcine kobuvirus’, have been identified in human, cattle and swine, respectively. In addition, kobu‐like viruses were detected very recently in the bat. Aichi virus could be one of the causative agents of gastroenteritis in humans, and kobuviruses probably also cause diarrhoea in cattle and swine. Although Aichi virus has been detected relatively infrequently (0–3%) in human diarrhoea, high seroprevalence, up to 80–95% at the age of 30–40, was found indicating the general nature of infection in different human populations. In the previous years, much new information has accumulated relating to kobuviruses and their host species. This review summarises the current knowledge on kobuviruses including taxonomy, biology and viral characteristics, and covers all aspects of infection including epidemiology, clinical picture, host species diversity, laboratory diagnosis and it gives a summary about possible future perspectives. Copyright © 2011 John Wiley & Sons, Ltd.
Cooperative control of multiple surface vessels with discrete‐time periodic communications
Authors: Almeida J. , Silvestre C. , Pascoal A. M. 
Published: February 2011

SUMMARYThis paper addresses the problem of cooperative path‐following of networked autonomous surface vessels with discrete‐time periodic communications. The objective is to steer a group of autonomous vehicles along given spatial paths, while holding a desired inter‐vehicle formation pattern. For a given class of marine vessels, we show how Lyapunov‐based techniques, graph theory, and results from networked control systems can be brought together to yield a decentralized control structure where the dynamics of the cooperating vessels and the constraints imposed by the topology of the inter‐vehicle communication network are explicitly taken into account. Cooperation is achieved by adjusting the speed of each vessel along its path according to information exchanged periodically on the positions of a subset of the other vessels, as determined by the communications topology adopted. The closed‐loop system that is obtained by putting together the path‐following and cooperation strategies takes an interconnected feedback form where both systems are input‐to‐state stable with respect to the outputs of each other. Using a small‐gain theorem, stability and convergence of the overall system are guaranteed for adequate choices of the controller gains. Copyright © 2011 John Wiley & Sons, Ltd.
Networked‐based stabilization via discontinuous Lyapunov functionals
Authors: Liu Kun , Fridman Emilia 
Published: February 2011

SUMMARYThis paper presents a new stability and L2‐gain analysis of linear Networked Control Systems (NCS). The new method is inspired by discontinuous Lyapunov functions that were introduced by Naghshtabrizitextitet al. (Syst. Control Lett. 2008; 57:378–385; Proceedings 26th American Control Conference, New York, U.S.A., July 2007) in the framework of impulsive system representation. Most of the existing works on the stability of NCS (in the framework of time delay approach) are reduced to some Lyapunov‐based analysis of systems with uncertain and bounded time‐varying delays. This analysis via time‐independent Lyapunov functionals does not take advantage of the sawtooth evolution of the delays induced by sample‐and‐hold. The latter drawback was removed by Fridman (Automatica 2010; 46:421–427), where time‐dependent Lyapunov functionals for sampled‐data systems were introduced. This led to essentially less conservative results. The objective of the present paper is to extend the time‐dependent Lyapunov functional approach to NCS, where variable sampling intervals, data packet dropouts, and variable network‐induced delays are taken into account. The Lyapunov functionals in this paper depend on time and on the upper bound of the network‐induced delay, and these functionals do not grow along the input update times. The new analysis is applied to the state‐feedback and to a novel network‐based static output‐feedback H∞ control problems. Numerical examples show that the novel discontinuous terms in Lyapunov functionals essentially improve the results. Copyright © 2011 John Wiley & Sons, Ltd.
A privacy‐aware overlay routing scheme in WSNs
Authors: Kazatzopoulos L. , Delakouridis K. , Marias G. F. 
Published: February 2011

AbstractIn most of the wireless sensor networks (WSNs) configurations, the sensors are statically deployed and configured to propagate the captured information towards a sink‐sensor, a gateway with legacy systems or the internet. The captured information might be unclassified, such as environmental data, or classified as private information, such as the location of an important asset, person, or actuator. In the latter case, privacy enhancement mechanisms might be essential to ensure the confidentiality of the propagated information, as well as the location of the information source (i.e., a sensor). Light cryptographic cyptosystems, such us Elliptic Curve, might be useful to cipher the information that is relayed towards the sink. On the other hand, the static deployment of sensors in WSN simplifies the reveal of the information source. An eavesdropper might use reverse packet‐routing to identify the location of the source sensor, i.e., the one that captured and reported the information. To deal with these issues, and enhance source‐location privacy, information secrecy in WSNs, ensure source‐to‐sink unlinkability, without complex and demanding crypto‐operations, we have introduced a novel approach that uses a non–geographical, overlay routing method for packet forwarding, routing, and delivery. This paper introduces the architecture of the approach, and assesses its performance through simulation experiments, providing comparisons with relative approaches. Copyright © 2011 John Wiley & Sons, Ltd.
A non‐associative lattice‐based public key cryptosystem
Authors: Malekian Ehsan , Zakerolhosseini Ali 
Published: February 2011

AbstractIn this paper we will prove that a lattice‐based public key cryptosystem based on non‐associative algebra is not only feasible but also arguably more secure than the existing lattice based cryptosystems such as NTRU, because its lattice does not fully fit within circular and convolutional modular lattice (CCML).The underlying algebraic structure of the proposed non‐associative cryptosystem is the power‐associative and alternative octonions algebra which can be defined over any Dedekind domain such as convolution polynomial ring.Besides the detailed specification of the proposed cryptosystem, we have proved that the security of the proposed scheme relies on the difficulty of the finding shortest vector in a certain kind of lattice. Since there is no isomorphic matrix representation for octonions, the only method for attacking the proposed cryptosystem and finding a spurious key for decryption is to form a lattice of dimension 16.N which is eight times larger than the NTRU lattice. By reducing the dimension of the underlying convolution polynomial ring (N) and using optimization techniques, we can increase the encryption and decryption speed, to a level equal to NTRU.Mathematics Subject Classification (2000): 94A60, 11T71 Copyright © 2011 John Wiley & Sons, Ltd.
Quantifying bias in a health survey: Modeling total survey error in the National Immunization Survey
Authors: Molinari NoelleAngelique M. , Wolter Kirk M. , Skalland Benjamin , Montgomery Robert , Khare Meena , Smith Philip J. , Barron Martin L. , Copeland Kennon , Santos Kathleen , Singleton James A. 
Published: February 2011

AbstractRandom‐digit‐dial telephone surveys are experiencing both declining response rates and increasing under‐coverage due to the prevalence of households that substitute a wireless telephone for their residential landline telephone. These changes increase the potential for bias in survey estimates and heighten the need for survey researchers to evaluate the sources and magnitudes of potential bias.We apply a Monte Carlo simulation‐based approach to assess bias in the NIS, a land‐line telephone survey of 19–35 month‐old children used to obtain national vaccination coverage estimates. We develop a model describing the survey stages at which component nonsampling error may be introduced due to nonresponse and under‐coverage. We use that model and components of error estimated in special studies to quantify the extent to which noncoverage and nonresponse may bias the vaccination coverage estimates obtained from the NIS and present a distribution of the total survey error.Results indicated that the total error followed a normal distribution with mean of 1.72 per cent(95 per cent CI: 1.71, 1.74 per cent) and final adjusted survey weights corrected for this error. Although small, the largest contributor to error in terms of magnitude was nonresponse of immunization providers. The total error was most sensitive to declines in coverage due to cell phone only households. These results indicate that, while response rates and coverage may be declining, total survey error is quite small. Since response rates have historically been used to proxy for total survey error, the finding that these rates do not accurately reflect bias is important for evaluation of survey data. Published in 2011 by John Wiley & Sons, Ltd.
Estimation of reliability in a three‐factor model
Authors: Wang Luqiang , Keen Kevin John , Holland Burt 
Published: February 2011

AbstractReliability measures have been well studied over many years. Such measures have been thoroughly studied for two‐factor models. Motivated by a medical research problem, point and confidence interval estimates of the intraclass correlation coefficient are extended to models containing three crossed random factors—subjects, raters, and occasions. The estimation is conducted using both analysis of variance and Monte Carlo Markov chain methods. Copyright © 2011 John Wiley & Sons, Ltd.
Nanotoxicology: Advanced Optical Imaging Reveals the Dependence of Particle Geometry on Interactions Between CdSe Quantum Dots and Immune Cells (Small 3/2011)
Authors: Aaron Jesse S. , Greene Adrienne C. , Kotula Paul G. , Bachand George D. , Timlin Jerilyn A. 
Published: February 2011

AbstractThe biocompatibility and possible toxicological consequences of engineered nanomaterials, including quantum dots (QDs) due to their unique suitability for biomedical applications, remain intense areas of interest. We utilized advanced imaging approaches to characterize the interactions of CdSe QDs of various sizes and shapes with live immune cells. Particle diffusion and partitioning within the plasma membrane, cellular uptake kinetics, and sorting of particles into lysosomes were all independantly characterized. Using high‐speed total internal reflectance fluorescence (TIRF) microscopy, we show that QDs with an average aspect ratio of 2.0 (i.e., rod‐shaped) diffuse nearly an order of magnitude slower in the plasma membrane than more spherical particles with aspect ratios of 1.2 and 1.6, respectively. Moreover, more rod‐shaped QDs were shown to be internalized into the cell 2‐3 fold more slowly. Hyperspectral confocal fluorescence microscopy demonstrates that QDs tend to partition within the cell membrane into regions containing a single particle type. Furthermore, data examining QD sorting mechanisms indicate that endocytosis and lysosomal sorting increases with particle size. Together, these observations suggest that both size and aspect ratio of a nanoparticle are important characteristics that significantly impact interactions with the plasma membrane, uptake into the cell, and localization within intracellular vesicles. Thus, rather than simply characterizing nanoparticle uptake into cells, we show that utilization of advanced imaging approaches permits a more nuanced and complete examination of the multiple aspects of cell‐nanoparticle interactions that can ultimately aid understanding possible mechanisms of toxicity, resulting in safer nanomaterial designs.
An exercise in flexible formal modeling under realistic assumptions
Authors: Wedde Horst F. 
Published: February 2011

AbstractA brief introduction into the Theory of Interaction Systems is given. This is an innovative general formal tool for adequately modeling very large and complex dynamical systems (distributed systems). The formalism is purely built on interaction primitives. In order to demonstrate its possible use as a modeling and communication tool for the design and development phase of a large real modeling/reorganization process a developing elevator problem is defined and discussed which adequately reflects essential aspects of a real modeling process: Uncertainty of observations, partial autonomy of subsystems, limited range of decisions or of responsibility, interrelation of requirements on different design levels, partial reorganization/redesign. A formal solution is constructed for this problem in various iterative steps using standard constructions which describe the local change of requirements and which have a well‐defined global effect without influencing, or changing, the formal specification at, or for, distant locations or activities. So we prove the adequacy of our tools regarding the mentioned modeling aspects, in particular their flexibility. It is explained how the formal approach of interaction systems may help to constitute innovative forms of formal reasoning and of systems thinking needed for a practice‐oriented systematic way of solving organizational/design problems in large real systems.
Holons: Three conceptions
Authors: Bahm Archie J. 
Published: February 2011

AbstractRecent advances in systems theory have required a new term, ‘holon’ (a whole of parts functioning as part of a larger whole). These advances are complicated by differing interpretations provided by three competing kinds of general systems theory: Emergentism, structuralism and organicism. For emergentism, use of the term signifies a shift in emphasis from focusing on the dynamic equilibrium between a whole and its parts to that between the whole and the larger whole of which it is a part. For structuralism, the term serves in explaining subsystem adaptation to environmental and hierarchical constraints and determinations by invariant principles. By incorporating ideas from both emergentism and structuralism into its more intricate interpretations, the author claims that organicism presents a more adequate conception of the nature of holons—now regarded as essential to general systems thinking.
Toward systemic education of systems scientists
Authors: Gharajedaghi Jamshid , Ackoff Russell L. 
Published: February 2011

AbstractThe systems view of the world includes a system of concepts, a body of theory, a theory of practice and methodologies of research on, planning for and design of systems. The making of systems scientists involves their learning all these things. But the educational media used in systems education are mechanistically conceived however systemic the messages they deliver. Therefore, there is a fundamental contradiction between the media and the message, and, we believe, the media dominate.Mechanically conceived education is analytic. It disassembles that which is to be learned reducing it to a number of discrete and disconnected parts. But systems learning is a whole that cannot be easily divided into independent parts. The essential properties of this whole are lost when it is taken apart. The parts, as well, lose their essential properties when they are separated from the whole.Analysis of a system reveals its structure; synthesis is also required to appreciate its function. Thus analysis and synthesis are complementary; neither replaces the other. Systems learning incorporates both.
Complexity: Some general observations
Authors: Klir George J. 
Published: February 2011

AbstractAn attempt is made in this article to develop a general framework for dealing with the various issues associated with the notion of complexity. It is argued that complexity, in the epistemological and methodological sense, is associated with systems defined on objects of interest rather than the objects themselves. Basic types of systems are outlined in the article. It is shown that systems complexity has different meanings for different types of systems while, at the same time, it possesses some general features that are invariant of systems types. Two general kinds of complexity of a system are proposed, which are connected with the amounts of information required to describe the system and to resolve uncertainty associated with it. A general simplification problem, which is applicable to systems of any type, is formulated, and some fundamental simplification strategies are overviewed.