bluuebunny/crossref_metadata_2025 huggingface dataset:
Data Communication
Authors: Yu Oliver
Published: January 2008

This chapter focuses on data communication between directly connected devices through a transmission medium with or without multiaccess, and in particular focuses on the physical and data link layers in the OSI reference model. At the physical layer, devices exchange unstructured data bit stream via modulated electromagnetic signal transmission over a physical link channel. Modulation determines the ratio of the transmitted data bit rate to the signal bandwidth. Data errors may occur because of the signal impairments by channel noises. At the link layer, devices exchange structured data bit stream via frames over a logical link channel with error recovery control to optimize link reliability. Channel coding adds structured redundancy to the data bit stream to enable error detection or error correction. Each frame consists of the data payload and the control overhead bits, which convey control procedures between sending and receiving devices. Link control procedures include flow control, error recovery, and device addressing in multiaccess medium. Emerging multinput–multi‐output (MIMO) transmission with multiple signal waveform generators (i.e., antenna array) optimizes throughput capacity and link reliability through space (antenna) time coding.
Transaction Processing in Mobile, Heterogeneous Database Systems
Authors: Lim J. B. , Hurson A. R. , Jiao Y.
Published: January 2008

The rapid explosion in the use of wireless devices, combined with the simultaneous infrastructure expansion required to suport a massive number of users, has made ubiquitous access to data a reality. When a large number of users simultaneously accesses global data in a mobile computing environment, an efficient means to manage a large amount of concurrent transactions is required. Current multi‐database concurrency control schemes do not address the limited bandwidth and frequent disconnections associated with wireless networks. This article describes a new hierarchical concurrency control algorithm, v‐lock, that addresses the shortcomings of existing multi‐database concurrency control schemes. The algorithm uses global locking tables created with semantic informantion contained within a hierarchy to serialize global transactions, and remove global deadlocks.

Additionally, wireless transmission of data is subject to weak or frequent disconnection. With the increased amount of local memory available at the mobile unit, data replication can be used to provide local data availability, limiting the restrictions imposed by a wireless mobile environment. In a mobile, multi‐database environment, local autonomy restrictions prevent the use of a page‐or‐file‐based data replication scheme. This article describes a new data replication scheme to address to limited bandwidth and local autonomy restrictions. Consistency is maintained by using a parity‐based invalidation scheme of data cached at the mobile unit. Additionally, a simple prefetching scheme is used to further improve the effectiveness of the proposed scheme. Finally, simulated results of the concurrency control and replication algorithms are presented and discussed.
Visual Database
Authors: Yang Li , Kunii Tosiyasu L.
Published: January 2008

This article introduces principles and techniques developed for the management of visual data and for supporting visual queries against databases that manage the visual data. It presents an overview of well‐established approaches that are used in visual databases today for image feature extraction, visual data retrieval, indexing, and user query interfaces. Example visual database systems are described briefly. Finally, this article gives a list of survey papers that address technical issues related to visual data management.
Markov Chains
Authors: Johansen Adam M.
Published: January 2008

A Markov chain is a collection of random variables with a temporal ordering that have the property that “conditional upon the present, the future does not depend upon the past.” This concept, which can be viewed as a form of something known as the Markov property, is the defining characteristic of the Markov chain. Such systems occur very widely throughout the physical and information sciences as well as in a broad range of other application domains. In addition to their utility in modeling real systems, several computational techniques make use of Markov chains, particularly in the field of Monte Carlo methods.

The ubiquity of the Markov chain originates from the fact that such collections lie somewhere between one of independent random variables and a completely general collection, which could be extremely complex to deal with. A sufficient structure is available to allow sophisticated analysis; sufficient generality is available to allow a broad class of systems to be described in terms of Markov chains.
Color Perception
Authors: Ramanath Rajeev , Drew Mark S.
Published: January 2008

The term color has widespread usage in common language and technical jargon yet its correct application eludes the research community and remains a hotly debated topic in the technical communities. It draws interest from a variety of fields, most likely due to its pervasive use in literature and language. In this article we will look at the various modes of color perception.
Scale‐Space
Authors: Lindeberg Tony
Published: January 2008

Scale‐space theory is a framework for multiscale image representation, which has been developed by the computer vision community with complementary motivations from physics and biologic vision. The idea is to handle the multiscale nature of real‐world objects, which implies that object may be perceived in different ways depending on the scale of observation. If one aims to develop automatic algorithms for interpreting images of unknown scenes, no way exists to know a priori what scales are relevant. Hence, the only reasonable approach is to consider representations at all scales simultaneously. From axiomatic derivations is has been shown that given the requirement that coarse‐scale representations should correspond to true simplifications of fine scale structures, convolution with Gaussian kernels and Gaussian derivatives is singled out as a canonical class of image operators forthe earliest stages of visual processing. These image operators can be used as basis to solve a large variety of visual tasks, including feature detection, feature classification, stereo matching, motion descriptors, shape cues, and image‐based recognition. By complementing scale‐space representation with a module for automatic scale selection based on the maximization of normalized derivatives over scales, early visual modules can be made scale invariant. In this way, visual modules canadapt automatically to the unknown scale variations that may occur because of objects and substructures of varying physical size as well as objects with varying distances to the camera. An interesting similarity to biologic vision is that the scale‐space operators resemble closely receptive field profiles registered in neurophysiologic studies of the mammalian retina and visual cortex.
Face Recognition Techniques
Authors: Zhao Wenyi
Published: January 2008

Biometrics is becoming a buzz word because of the increasing demand for user‐friendly systems that provide both secure and efficient services. At present, one needs to remember numbers and/or carry identifications (ID) all the time, for example, a badge ID entering an office building, a password for computer or ATM access, and a photo‐ ID as wall as an airline ticket for air travel. Although very reliable methods of biometric personal identification exist (e.g., fingerprint analysis and iris scans), these methods rely on the cooperation of the participants, whereas a personal identification system based on the analysis of frontal or profile images of the face is often effective without the participant's cooperation or knowledge. Face recognition is a fascinating research topic. On one hand, many algorithms and systems have reached a certain level of maturity after 35 years of research. For example, face detection technology has been used in digital cameras for automatic focus/exposure. On the other hand, the success of these systems is limited by the conditions imposed by many real applications. The focus of current face recognition research is to investigate various techniques to improve the robustness of existing face recognition systems while the ultimate goal is to build machine systems that are close to or even better than the human perception system.
Fingerprint Identification
Authors: Wang Rong , Bhanu Bir
Published: January 2008

Biometrics such as fingerprint, palm, face, gait, ear, signature, and speech are used to ensure a high‐confidence in the recognition of an individual for high‐security applications. Among these biometric traits, fingerprints have been used for a long period of time because of their distinctiveness and immutability. The study of fingerprint characteristics can be traced back to about 4500 years, the era of the pyramid‐building in Egypt. However, the use of fingerprints for identification began in the mid‐1800s.

Fingerprints have two fundamentally important characteristics: permanence and distinctiveness. It has been found that fingerprints are formed in the fetal stage and do not change naturally. Also, no two fingerprints ever are found to be exactly the same. Because of these interesting characteristics, fingerprints are used widely for human recognition and identification.
Software Quality Classification Models
Authors: Shin Miyoung , Goel Amrit L.
Published: January 2008

This article addresses the development of analytical models to identify fault‐prone components. Because of the lack of physical underpinnings, the software development mechanism is not understood well enough to derive theory‐based models. Therefore, these models are obtained from experimental or historical data after an iterative process. Some commonly used techniques and a recent methodology based on radial basis functions are described. A case study is presented to illustrate the model's development, evaluation, and selection process.
Ethics and Professional Responsibility in Computing
Authors: Loui Michael C. , Miller Keith W.
Published: January 2008

Computing professionals have ethical obligations to clients, employers, other professionals, and the public in fulfilling their professional responsibilities. These obligations are expressed in codes of ethics, which can be used to make decisions about ethical problems.
Computational Intelligence
Authors: Peters James F. , Pedrycz Witold
Published: January 2008

Several interpretations of the notion of computational intelligence (CI) exist. Computationally intelligent systems have been characterized by Bezdek relative to adaptivity, fault‐tolerance, speed, and error rates. In its original conception, many technologies belonged to computational intelligence, namely, neural networks, genetic algorithms, fuzzy systems, evolutionary programming, and artificial life. More recently, rough set theory and its extensions to approximate reasoning and real‐time decision systems have been considered in the context of computationally intelligent systems. Overall, CI can be regarded as a synergy of genetic, fuzzy, rough, and neural computing.
Computing Accreditation: Evolution and Trends Associated with
U
.
S
. Accrediting Agencies
Authors: Yaverbaum Gayle J. , Reichgelt Han
Published: January 2008

Accreditation is evolving to be an acceptable measure of a quality computing program. Several agencies provide evaluation of specialized technology programs or units in which such programs exist. This article reviews the fundamental history of computing accreditation, primarily in the United States. The fundamental concepts of accreditation, accreditation agencies, and the process itself are discussed.
Quality in Computer Science and Computer Engineering Education
Authors: McGettrick Andrew
Published: January 2008

A variety of interpretations exist for the term
quality
as it is used in higher education. Although minor, the various interpretations often point to fundamental differences in philosophy about aspects of higher education across different countries and indeed about its management. The purpose of this article is to focus on the major quality and accrediting mechanisms that exist in higher eduction and to explore aspects of their operation.
Fluency with Information Technology
Authors: Snyder Lawrence
Published: January 2008

Fluency with Information Technology
specifies a degree of competency with computers and information in which users possess the skills, concepts, and capabilities needed to apply Information Technology (IT) confidently and effectively and can acquire new knowledge independently. Fluency with Information Technology transcends computer literacy and prepares students for lifelong learning of IT.

The concept of
Fluency with Information Technology
derives from a National Research Council (NRC) study initiated in 1997 and funded by the National Science Foundation (NSF). The study focused on defining “what everyone should know about Information Technology.” For the purposes of the study, “everyone” meant the population at large, and IT was defined broadly to include computers, networking, software and applications, as well as information resources—virtually anything one would encounter using a network‐connected personal computer.
Cover Picture: Dynamic Imaging of Functionalized Multi‐Walled Carbon Nanotube Systemic Circulation and Urinary Excretion (Adv. Mater. 2/2008)
Authors: Lacerda L. , Soundararajan A. , Singh R. , Pastorin G. , Al‐Jamal K. T. , Turton J. , Frederik P. , Herrero M. A. , Li S. , Bao A. , Emfietzoglou D. , Mather S. , Phillips W. T. , Prato M. , Bianco A. , Goins B. , Kostarelos K.
Published: January 2008

Multiwalled carbon nanotubes (MWNTs) made highly water‐dispersible by organic functionalization and radiolabeled with Indium‐111 were shown to translocate through the kidney glomerular filter. On p. 225, multinational, multicenter research led by Kostas Kostarelos on dynamic imaging and tissue distribution of MWNTs in live animals is presented. The cover image presents a single plane single photon computed tomography whole body image of a rat following intravenous injection with the In‐111 labeled MWNTs as seen through a 3D carbon NT projection. The radioactivity from carbon NTs was mainly localized in the kidneys, and accumulated in the bladder before clearance in the urine.
Inside Front Cover: Controlling Morphology in Polymer–Fullerene Mixtures (Adv. Mater. 2/2008)
Authors: Moulé A. J. , Meerholz K.
Published: January 2008

On p. 240, Klaus Meerholz and co‐workers show control over the aggregation of P3HT in solution by mixing a dipolar, but miscible solvent to the coating solution. The resulting nanoparticle dispersions are stable and allow a quantitative comparison of the absorption spectra of amorphous and aggregated P3HT. These results are interesting not only because they allow control of morphology on the nanometer scale, but they also show a path to low‐cost morphological control of large‐area films, which is an essential step for the commercialization of plastic PV devices.
The thrifty epigenotype: An acquired and heritable predisposition for obesity and diabetes?
Authors: Stöger Reinhard
Published: January 2008

Obesity and type 2 diabetes arise from a set of complex gene–environment interactions. Explanations for the heritability of these syndromes and the environmental contribution to disease susceptibility are addressed by the “thrifty genotype” and the “thrifty phenotype” hypotheses. Here, the merits of both models are discussed and elements of them are used to synthesize a “thrifty epigenotype” hypothesis. I propose that: (1) metabolic thrift, the capacity for efficient acquisition, storage and use of energy, is an ancient, complex trait, (2) the environmentally responsive gene network encoding this trait is subject to genetic canalization and thereby has become robust against mutational perturbations, (3) DNA sequence polymorphisms play a minor role in the aetiology of obesity and type 2 diabetes—instead, disease susceptibility is predominantly determined by epigenetic variations, (4) corresponding epigenotypes have the potential to be inherited across generations, and (5) Leptin is a candidate gene for the acquisition of a thrifty epigenotype. BioEssays 30:156–166, 2008. © 2008 Wiley Periodicals, Inc.
Hagfish (cyclostomata, vertebrata): Searching for the ancestral developmental plan of vertebrates
Authors: Kuratani Shigeru , Ota Kinya G.
Published: January 2008

The phylogenetic position of the hagfish remains enigmatic. In contrast to molecular data that suggest monophyly of the cyclostomes, several morphological features imply a more ancestral state of this animal compared with the lampreys. To resolve this question requires an understanding of the embryology of the hagfish, especially of the neural crest. The early development of the hagfish has long remained a mystery. We collected a shallow‐water‐dwelling hagfish, Eptatretus burgeri, set up an aquarium tank designed to resemble its habitat, and successfully obtained several embryos. By observing the histology and expression of genes known to play fundamental roles in the neural crest, we found that the hagfish crest develops as delaminating migratory cells, as in other vertebrates. We conclude that the delaminating neural crest is a vertebrate synapomorphy that seems to have appeared from the beginning of their evolutionary history, before the splitting away of the hagfish lineage. BioEssays 30:167–172, 2008. © 2008 Wiley Periodicals, Inc.
Anion Recognition and Templation in Coordination Chemistry (Eur. J. Inorg. Chem. 3/2008)
Authors: Vilar Ramon
Published: January 2008

Cover Picture: Metalloreceptors for the molecular recognition of anions or anion templates for the synthesis of metalloreceptors? Both! This figure shows the crystal structures of two metallohosts with the corresponding anionic guest “trapped” within the hydrogen‐bonding clefts. In one case (structure shown at the top), the complex was prepared without the need for an anion template. Once formed, this dipalladium complex with urea‐containing ligands binds a range of different anions in competing solvents. The structure shown at the bottom of the figure is that of a tetrametallohost, which only forms in the presence of the appropriate anionic template. This microreview on p. 357 ff aims to give an overview of the research carried out in the author's group in the area of anion recognition and templation in coordination chemistry.
Server placement and path selection for QoS‐enabled overlay networks
Authors: De Vleeschauwer Bart , De Turck Filip , Dhoedt Bart , Demeester Piet
Published: January 2008

Multimedia services are in strong need of end‐to‐end Quality of Service (QoS) and multicasting support. This need cannot be fulfilled by the current Internet yet, due to difficulties associated with implementing these techniques ubiquitously across the numerous autonomous systems of this global network. Overlay Networks offer a means to implement these advanced network features in a logical overlay layer on top of the Internet. The problem of finding the locations of the overlay servers, coupled with the paths that are selected, has not yet been studied in sufficient detail. Therefore, we present a formal multilayer formulation of the server location and path selection problem for these overlay networks as an Integer Linear Programming (ILP) problem. An algorithm based on standard ILP solution techniques and a number of heuristics were developed. These algorithms are compared with each other and with standard Internet routing in terms of acceptance rate, end‐to‐end delay and usage of the network bandwidth. Copyright © 2008 John Wiley & Sons, Ltd.
Reciprocal and complementary sibling interactions, relationship quality and socio‐emotional problem solving
Authors: Karavasilis Karos Leigh , Howe Nina , Aquan‐Assee Jasmin
Published: January 2008

Associations between reciprocal and complementary sibling interactions, sibling relationship quality, and children's socio‐emotional problem solving were examined in 40 grade 5–6 children (Mage = 11.5 years) from middle class, Caucasian, Canadian families using a multi‐method approach (i.e. interviews, self‐report questionnaires, daily diary checklist, narrative task). Findings demonstrated that reciprocal sibling interactions were positively associated with warmth, mutual esteem, happy daily exchanges, and negatively related to rivalry and dominance, whereas complementary interactions were positively related to upsetting daily exchanges. Further, reciprocal and complementary interactions differed significantly in relation to several relationship qualities, with reciprocal interactions emerging as a significantly stronger correlate of happy exchanges. Only reciprocal interactions were positively correlated with socio‐emotional problem solving. Finally, birth order moderated the negative association of reciprocal interactions with rivalry and dominance and the positive association with socio‐emotional problem solving. In each case, the effect was stronger for younger members of the sibling dyad. Findings are discussed in light of recent theory on the sibling relationship and children's development. Copyright © 2007 John Wiley & Sons, Ltd.
Predicting school adjustment from motor abilities in kindergarten
Authors: Bart Orit , Hajami Dov , Bar‐Haim Yair
Published: January 2008

The present study assessed the relations between basic motor abilities in kindergarten and scholastic, social, and emotional adaptation in the transition to formal schooling. Seventy‐one five‐year‐old kindergarten children were administered a battery of standard assessments of basic motor functions. A year later, children's adjustment to school was assessed via a series of questionnaires completed by the children and their class teachers. The results indicate that in addition to the already documented association between visual–motor integration and academic achievement, other motor functions show significant predictive value to both scholastic adaptation and social and emotional adjustment to school. The results further suggest a better prediction of scholastic adaptation and level of disruptive behaviour in school when using an aggregate measure of children's ability in various motor domains than when using assessments of singular motor functions. It is concluded that good motor ability may serve as a buffer to the normative challenges presented to children in the transition to school. In contrast, poor motor ability emerges as a vulnerability factor in the transition to formal schooling. Copyright © 2007 John Wiley & Sons, Ltd.
Positive organizational behavior: engaged employees in flourishing organizations
Authors: Bakker Arnold B. , Schaufeli Wilmar B.
Published: January 2008

This editorial introduces a special issue of the Journal of Organizational Behavior onpositive organizational behavior(POB). POB emphasizes the need for more focused theory building, research, and effective application of positive traits, states, and behaviors of employees in organizations. We argue that in order to make a substantive contribution to organizational science, POB will need to show the added value of the positive over and above the negative. In addition, the emerging concept of employee engagement is briefly introduced. The papers in the special issue describe exciting positive organizational behavior studies that each tap into an interesting direction in which POB research might go. Copyright © 2008 John Wiley & Sons, Ltd.
A generalized eigensolver based on smoothed aggregation (GES‐SA) for initializing smoothed aggregation (SA) multigrid
Authors: Brezina M. , Manteuffel T. , McCormick S. , Ruge J. , Sanders G. , Vassilevski P.
Published: January 2008

Consider the linear system Ax=b, where A is a large, sparse, real, symmetric, and positive‐definite matrix and b is a known vector. Solving this system for unknown vector x using a smoothed aggregation (SA) multigrid algorithm requires a characterization of the algebraically smooth error, meaning error that is poorly attenuated by the algorithm's relaxation process. For many common relaxation processes, algebraically smooth error corresponds to the near‐nullspace of A. Therefore, having a good approximation to a minimal eigenvector is useful to characterize the algebraically smooth error when forming a linear SA solver. We discuss the details of a generalized eigensolver based on smoothed aggregation (GES‐SA) that is designed to produce an approximation to a minimal eigenvector of A. GES‐SA may be applied as a stand‐alone eigensolver for applications that desire an approximate minimal eigenvector, but the primary purpose here is to apply an eigensolver to the specific application of forming robust, adaptive linear solvers. This paper reports the first stage in our study of incorporating eigensolvers into the existing adaptive SA framework. Copyright © 2008 John Wiley & Sons, Ltd.
Chromatographic Analysis of Kutajarista—an Ayurvedic Polyherbal Formulation
Authors: Garg Shivali , Bhutani K. K.
Published: January 2008

Kutajarista is a well known polyherbal preparation of which the main ingredient is the stem bark of Holarrhena antidysenterica. This Ayurvedic medicine is prescribed to treat amoebic dysentery and other disorders such as fever, indigestion and malabsorption syndrome. Herbal medicines are very important since, in common with conventional medicines, they contain biologically active substances that may produce non‐trivial side effects when taken in excessive amounts. Very low doses, on the other hand, may have no therapeutic value. In this paper we report the chemical standardisation of Kutajarista by HPLC analysis based upon the presence of the biomarker conessine in the formulation. The standardisation method is simple and reliable, and the precision of method has been tested for repeatability (n = 3) and reproducibility (n = 9). The response of a refractive index detector was linear in the concentration range of 0.1–1.0 mg/mL. Recovery studies were performed to check the method for accuracy. The recovery was found to be in range of 99–105%. The developed HPLC method can be used to quantify conessine for quality control of marketed Kutajarista samples. Copyright © 2008 John Wiley & Sons, Ltd.
Quantification of artemisinin in Artemisia annua extracts by 1H‐NMR
Authors: Castilho Paula C. , Gouveia Sandra C. , Rodrigues Ana I.
Published: January 2008

Artemisinin is a polycyclic sesquiterpene lactone that is highly effective against multidrug‐resistant strains of Plasmodium falciparum, the etiological agent of the most severe form of malaria. Determination of artemisinin in the source plant, Artemisia annua, is a challenging problem since the compound is present in very low concentrations, is thermolabile and unstable, and lacks chromophoric or fluorophoric groups. The ain of this study was to develop a simple protocol for the quantification of artemisinin in a plant extract using an 1H‐NMR method. Samples were prepared by extraction of leaf material with acetone, treatment with activated charcoal to remove chlorophylls and removal of solvent. 1H‐NMR spectra were measured on samples dissolved in deuterochloroform with tert‐butanol as internal standard. Quantification was carried out using the $\d{$\delta$}$ 5.864 signal of artemisinin and the δ 1.276 signal of tert‐butanol. The method was optimised and fully validated against a reference standard of artemisinin. The results were compared with those obtained from the same samples quantified using an HPLC‐refractive index (RI) method. The 1H‐NMR method gave a linear response for artemisinin within the range 9.85–97.99 mm (r2 = 0.9968). Using the described method, yields of artemisinin in the range 0.77–1.06% were obtained from leaves of the A. annua hybrid CPQBA × POP, and these values were in agreement with those obtained using an HPLC‐RI. Copyright © 2008 John Wiley & Sons, Ltd.
Solution conformational preferences of glutaric, 3‐hydroxyglutaric, 3‐methylglutaric acid, and their mono‐ and dianions
Authors: Gerken James B. , Badger Claire , Bisbee Christopher , Gardner Sasha , Qi Yan , Vilà Víctor Durà , Roberts John D.
Published: January 2008

Conformational preferences of glutaric, 3‐hydroxyglutaric and 3‐methylglutaric acid, and their mono‐ and dianions have been investigated with the aid of NMR spectroscopy. In contrast to succinic acid, glutaric acid displays essentially statistical conformational equilibria in polar and non‐polar solutions of high and low hydrogen‐bonding ability with no clear evidence for intramolecular hydrogen‐bonding interactions. The acid ionization constant ratios, K
1/K2, in D2O and DMSO of glutaric, 3‐hydroxyglutaric, and 3‐methylglutaric acids also indicate that intramolecular interactions are much less important than, or indeed insignificant, for shorter‐chain acids. FTIR studies on 3‐methylglutaric acid indicate some preference for either association with solvent or dimerization, depending on the solvent, rather than intramolecular hydrogen bonding. Copyright © 2008 John Wiley & Sons, Ltd.
A kinetic model for water reactivity (avoiding activities) for hydrolyses in aqueous mixtures – selectivities for solvolyses of 4‐substituted benzyl derivatives in alcohol–water mixtures
Authors: Bentley T. William , Koo In Sun , Choi Hojune , Llewellyn Gareth
Published: January 2008

For solvolyses of various benzyl substrates in ethanol–water (EW) and methanol–water (MW) mixtures, product selectivities (S) are reported for chlorides at 75 °C defined as follows using molar concentrations: S = ([ether product]/[alcohol product]) × ([water]/[alcohol solvent]). The results support earlier evidence that solvolyses of 4‐nitrobenzyl substrates are SN2 processes, which are not susceptible to mechanistic changes over the whole range of solvents from water to alcohol. S values at 25 and/or 45 °C in EW and MW, and additional kinetic data including kinetic solvent isotope effects (KSIE) are reported for solvolyses of 4‐nitrobenzyl mesylate and tosylate. A kinetic model, explaining both rates and product, is proposed; a general medium effect due to solvent polarity is combined in one parameter with solvent effects on the nucleophilicity of the water and alcohol molecules acting as nucleophiles in SN2 reactions. According to this model, as alcohol is added to water the rate of reaction decreases due to a decrease in solvent polarity, but the nucleophilicity of water increases relative to alcohol. The availability of experimental rate and product data over the whole range of solvent compositions from alcohol to water, reveals limitations of alternative approaches using activities. Copyright © 2008 John Wiley & Sons, Ltd.
Top‐down proteomic analysis by MALDI‐TOF profiling: Concentration‐independent biomarkers
Authors: Nelsestuen Gary L. , Harvey Stephen B. , Zhang Yan , Kasthuri Raj S. , Sinaiko Alan R. , Ely E. Wesley , Bernard Gordon R. , Homoncik Monika , Jilma Bernd
Published: January 2008

Although numerous protein biomarkers have been correlated with advanced disease states, no new clinical assays have been developed. Goals often anticipate disease‐specific protein changes that exceed values among healthy individuals, a property common to acute phase reactants. This review considers somewhat different approaches. It focuses on intact protein isoform ratios that present a biomarker without change in the total concentration of the protein. These will seldom be detected by peptide level analysis or by most antibody‐based assays. For example, application of an inexpensive method to large sample groups resulted in observation of several polymorphisms, including the first structural polymorphism of apolipoprotein C1. Isoform distribution of this protein was altered and was eventually linked to increased obesity. Numerous other protein isoforms included C‐ and N‐terminal proteolysis, changes of glycoisoform ratios and certain types of sulfhydryl oxidation. While many of these gave excellent statistical correlation with advanced disease, clinical utility was not apparent. More important may be that protein isoform ratios were very stable in each individual. Diagnosis by longitudinal analysis of the same individual might increase sensitivity of protein biomarkers by 20‐fold or more. Protein changes that exceed the range of values found among healthy individuals may be uncommon.
Learning about seasons in a technologically enhanced environment: The impact of teacher‐guided and student‐centered instructional approaches on the process of students' conceptual change
Authors: Hsu Ying‐Shao
Published: January 2008

To explore the ways in which teacher‐guided and student‐centered instructional approaches influence students' conceptual understanding of seasonal change, we designed a technology‐enhanced learning (TEL) course to compare, by means of concept maps, the learning outcome of students in two groups: a teacher‐guided (TG) class (with whole‐class presentations) and a student‐centered (SC) class (with individual online learning). The participants were two classes of second‐year senior high school students in Taiwan. Overall, the results showed that most students developed a deep and accessible understanding of the reasons for the seasons after undergoing experiences provided by the TEL course. More importantly, it was found that, in this technologically enhanced environment, the student‐centered approach was more effective than the teacher‐guided approach in altering students' alternative conceptions of seasonal change (F = 28.05, p < 0.001). The conceptual evolution of students in the two groups was plotted and compared. These plots indicated that, first of all, the cognitive processes of contextualization and sense making helped students re‐examine their old ideas about the phenomena, leading them to generate alternative conceptions and undergo both positive and negative conceptual change. The student‐centered approach allows students to more freely test their own hypotheses in the processes of exploration and modeling, and thus move from assimilatory to properly scientific explanations. © 2008 Wiley Periodicals, Inc. Sci Ed 92:320–344, 2008
Measurement of photo‐patterned surface potential of Alq3 thin films by Kelvin‐force microscope together with near‐field optical stimulation
Authors: Ozasa Kazunari , Nemoto Shigeyuki , Isoshima Takashi , Ito Eisuke , Maeda Mizuo , Hara Masahiko
Published: January 2008

Uniform and extremely high surface potentials of tris(8‐hydroxyquinolinato) aluminum(III) (Alq3) thin films, formed spontaneously by vacuum evaporation of Alq3 in the dark, are patterned by contact‐mask photo‐exposure. The resulting surface‐potential patterns are observed by scanning‐probe Kelvin‐force microscope (KFM). Surface‐potential patterns on Alq3 thin films can be preserved in the dark for more than a year at − 20 °C. The dependence of photo‐induced reduction of surface potentials on photo‐exposure intensity is reproduced well by fitting calculation based on the assumption that the drift of photo‐excited electrons/holes decreases the surface potential. Two‐dimensional (2D) transfer functions of KFM probes are discussed from KFM potential profiles obtained for a step pattern of surface potential. Near‐field optical stimulation through an aperture of an optical fiber probe is demonstrated as scanning near‐field optical microscope (SNOM) combined with KFM (SNOM‐KFM). A photoemission pattern from an aperture of SNOM probes can be visualized as a surface‐potential pattern on Alq3 thin films by means of SNOM‐KFM measurements. Copyright © 2008 John Wiley & Sons, Ltd.
Quenched molecular dynamics studies on the extraction energy of aluminum atoms
Authors: Perron A. , Politano O. , Vignal V.
Published: January 2008

The extraction energy of an aluminum atom is calculated at 0 K as a function of coordination number and defect depth for three surface orientations [(100), (110) and (111)]. For each orientation, atoms are selected and extracted one by one. A linear relationship is obtained between the extraction energy of surface atoms and their coordination numbers (with slight variations due to the geometrical configuration of the atoms). However, the study of the influence of the defect depth on the extraction energy highlights the role played by intrinsic stress on the extraction energy. Copyright © 2008 John Wiley & Sons, Ltd.
Capillary rise between cylinders
Authors: Liu T. , Choi K. F.
Published: January 2008

The capillary rise of liquid in the gap between two closely spaced parallel cylinders, whose radii are different, was modeled in this paper. On the basis of the minimum free energy principle and interfacial analysis, the vertical capillary rise of liquid at equilibrium was calculated as a function of distance of separation of the two cylinders. In order to validate our theoretical calculation, a piece of experimental apparatus was designed and a series of experiments was conducted on it. Compared to the experimental data, our theoretical model gave a reasonably accurate prediction within experimental error. Copyright © 2008 John Wiley & Sons, Ltd.
XPS characterization of PTFE after treatment with RF oxygen and nitrogen plasma
Authors: Vesel Alenka , Mozetic Miran , Zalar Anton
Published: January 2008

A study on surface modification of extended PTFE (polytetrafluoroethylene) foil after treatment in oxygen and nitrogen plasma is presented. PTFE was exposed to a weakly ionized, highly dissociated RF plasma with a high density of neutral atoms. The gas pressure was 75 Pa and the discharge power was 200 W. The appearance of the functional groups on the sample surface was determined by using high‐resolution XPS. The results showed that oxygen plasma treatment did not cause any noticeable changes in the surface composition, while after nitrogen plasma treatment new functional groups were detected on the surface. Copyright © 2008 John Wiley & Sons, Ltd.
Mg‐Fe‐hydrotalcite as catalyst for the benzylation of benzene and other aromatics by benzyl chloride reactions
Authors: Tahir N. , Abdelssadek Z. , Halliche D. , Saadi S. , Chebout R. , Cherifi O. , Bachari K.
Published: January 2008

The benzylation of benzene and substituted benzenes reaction employing benzyl chloride as the alkylating agent over Mg‐Fe‐LDH (Mg/Fe = 2) clay without or with calcination (at 473–1073 K) has been investigated. Hydrotalcite before and after its calcination was characterized for surface area and crystalline phases. The catalyst derived from the hydrotalcite by its calcination at 473–1073 K show high catalytic activity for the benzylation of benzene and other aromatic compounds. The catalytically active species present in the catalyst in its most active form are the oxides of iron on the catalyst surface. The activity of the catalyst calcined at 1073 K for the benzylation of different aromatic compounds is in the following order: benzene> toluene> p‐xylene> anisole. Kinetics of the benzene benzylation over these catalysts have also been investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Changes in ultrasound morphology of the uterus and ovaries during the menopausal transition and early postmenopause: a 4‐year longitudinal study
Authors: Sokalska A. , Valentin L.
Published: January 2008

Objectives

To describe changes in uterine and ovarian size and morphology as determined by ultrasonography from 2 years before to 2 years after menopause.

Methods

Twenty 50‐year‐old women with fairly regular vaginal bleeding at the start of the study underwent transvaginal ultrasound examination every 3 months until 12 months postmenopause, then every 6 months until 24 months postmenopause. The results are presented from 2 years before to 2 years after the menopause.

Results

In the 2 years preceding menopause all the women were in menopausal transition. From 2 years before to 2 years after menopause uterine anteroposterior diameter decreased by 22% (mean) and left and right ovarian volumes by 45 and 20% (median), respectively. At 2 years before the menopause the total number of intraovarian follicle‐like cystic structures varied from 0 to 5, at the menopause from 0 to 7, and at 1 and 2 years after the menopause from 0 to 4 and from 0 to 2, respectively. Premenopause, the most common finding was that of ovaries containing either no follicles or a few follicles with at least one measuring ≥ 11 mm and simultaneously a hyperechogenic endometrium of varying thickness and not manifesting any midline echo or triple‐layer appearance. Images compatible with the late follicular phase were found in 6% (9/150) of examinations (‘cycle day’ 8–196) and images compatible with the luteal phase in 7% (10/150) (‘cycle day’ 11–56). Intraovarian cystic structures (3–25 mm) were seen in 14 women after the menopause.

Conclusion

We have described sonographic changes in the uterus and ovaries occurring during the transition from premenopause to postmenopause. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Selection of Appropriate Liver Resection in Left Hepatolithiasis Based on Anatomic and Clinical Study
Authors: Lee Seung Eun , Jang Jin‐Young , Lee Jeong Min , Kim Sun‐Whe
Published: January 2008

Background

Because of the possibility of injury to the left medial section of the bile duct (B4) and the presumed higher recurrence rate of hepatolithiasis, some surgeons have recently preferred left hepatectomy for left hepatolithiasis. We investigated the appropriate treatment for left hepatolithiasis by evaluating the anatomy and variations of the left hepatic duct system in a normal population and analyzed the clinical outcome of liver resection.

Methods

We reviewed the magnetic resonance imaging results of 115 normal subjects who underwent a workup for living related liver donation. An imaginary surgical resection line was established based on the lateral margin of the umbilical portion of the liver in T2‐weighted axial images. The junction of B4 with the left hepatic duct was evaluated to determine the possibility of injury during liver resection. We also analyzed the clinical outcomes of 181 patients who underwent left lateral sectionectomy or left hepatectomy.

Results

The anatomic evaluation showed that B4 joined lateral to the umbilical portion of the liver in 7.0% (8/115) of cases. In patients with left hepatolithiasis, left hepatectomy was performed in 79 patients and left lateral sectionectomy in 102. The operating time for the left lateral sectionectomy was significantly shorter than that for left hepatectomy (p = 0.001). There were no significant differences in complications or recurrence of stones.

Conclusion

Preoperative cholangiography should be performed to evaluate the anatomy of the left hepatic duct to avoid injuring B4. For most cases of left hepatolithiasis without a left hilar stricture, left lateral sectionectomy is the safest, most effective treatment.
The Usefulness of Distal Splenorenal Shunt in Children with Portal Hypertension for the Treatment of Severe Thrombocytopenia and Leukopenia
Authors: Moon Suk‐Bae , Jung Sung‐Eun , Ha Jong‐Won , Park Kwi‐Won , Seo Jeong‐Kee , Kim Woo‐Ki
Published: January 2008

Background

In the current era of transplantation and therapeutic endoscopy, the role of the distal splenorenal shunt (DSRS) for portal hypertension (PH) has diminished. We reviewed the outcome of the use of DSRS in children to determine the usefulness of this operation.

Methods

In the follow‐up course for PH from 1987 to 2006, 15 patients who developed severe thrombocytopenia (platelet count < 50 × 103/mm3) and/or leukopenia (WBC count < 3000/mm3) with normal liver function were referred for DSRS. Primary diagnosis was portal vein thrombosis (N = 10) and congenital hepatic fibrosis (N = 5). Platelet, WBC count, liver function test, and spleen size were checked before and after DSRS. Shunt patency was accessed postoperatively. Operative morbidity, mortality, and long‐term outcomes were measured.

Results

Platelet count and WBC count increased in individual patients. Mean value of each count increased significantly after DSRS (p = 0.002,. 004, respectively). Spleen size decreased significantly (N = 7, p = 0.018). Shunt patency rate was 100%. There was one postoperative complication and no postoperative mortality. Two patients developed portopulmonary hypertension. No patients underwent subsequent transplantation or endoscopic treatment for gastroesophageal varices after DSRS.

Conclusions

DSRS is an effective and reliable procedure for children with PH and is still useful for selected pediatric patients.
Emergency Laparoscopic‐assisted versus Open Right Hemicolectomy for Obstructing Right‐sided Colonic Carcinoma: A Comparative Study of Short‐term Clinical Outcomes
Authors: Ng Simon S. M. , Lee Janet F. Y. , Yiu Raymond Y. C. , Li Jimmy C. M. , Leung Wing Wa , Leung Ka Lau
Published: January 2008

Background

The aim of the present study was to compare the clinical outcomes of emergency laparoscopic‐assisted versus open right hemicolectomy for obstructing right‐sided colonic carcinoma.

Methods

Between July 2003 and July 2006, 43 consecutive patients with obstructing right‐sided colonic carcinoma underwent emergency right hemicolectomy at our institution, 14 with the laparoscopic‐assisted approach and 29 with the open approach. Clinical data were retrospectively recorded and compared between the two groups.

Results

There were no significant differences between the two groups with respect to age, gender, co‐morbidities, duration of obstructing symptoms, tumor length, and tumor staging. The laparoscopic‐assisted group had longer operative time than the open group (187.5 min versus 145 min; p = 0.034) but less blood loss (20 ml versus 100 ml; p = 0.020). The median time to full ambulation was significantly shorter in the laparoscopic‐assisted group (4 days versus 6 days; p = 0.016), but the time to return of gastrointestinal function and the duration of hospital stay were similar between the two groups. More patients in the open group developed postoperative complications (55.2% versus 28.6%), but the difference was not statistically significant.

Conclusions

Emergency laparoscopic‐assisted right hemicolectomy for obstructing right‐sided colonic carcinoma is feasible and safe. In comparison with the open approach, the laparoscopic‐assisted procedure is associated with less blood loss, earlier ambulation, and possibly lower morbidity rate.
Cyclosporine-A-induced nephrotoxicity in children with minimal-change nephrotic syndrome: long-term treatment up to 10 years
Authors: Kranz Birgitta , Vester Udo , Büscher Rainer , Wingen Anne-Margret , Hoyer Peter F.
Published: January 2008

The impact of cyclosporine A (CsA) therapy in patients with steroid-dependent nephrotic-syndrome (SDNS) on long-term renal function is controversial. Data beyond 5 years are rare. Long-term renal function was evaluated in children with SDNS with and without CsA therapy, especially beyond 5 years. Twenty children were treated with CsA (study group) for a mean of 5.4 ± 2.2 years (ten patients for 5–11 years). Glomerular filtration rate (GFR) was calculated before and after 3 and 12 months and at latest follow-up of therapy. Fifteen children with cyclophosphamide-treated SDNS without CsA served as controls. In the study group, GFR decreased within 12 months from 136 ± 19 to 120 ± 31, to 114 ± 14 ml/min per 1.73 m2at latest follow-up (p < 0.0001). Patients with CsA > 5 years had a GFR of 111 ± 14 ml/min per 1.73 m2at latest follow-up without a GFR below 90 ml/min per 1.73 m2. No CsA toxicity was found in biopsies. In the control group, GFR dropped within 3 months, from 137 ± 27 to 130 ± 24, to 126 ± 19 ml/min per 1.73 m2at latest follow-up (p = 0.1). Patients with and without nephrotoxic CsA therapy showed a drop in GFR. In CsA-treated patients, GFR was about 12% lower at latest follow-up compared with patients without nephrotoxic therapy but always remained within normal range. CsA seems to be safe, even in long-term treatment for more than 5 years.