bluuebunny/crossref_metadata_2025_split huggingface dataset:
Positron Emission Tomography (PET)
Authors: Kontaxakis George 
Published: April 2006

Abstract

Positron emission tomography (PET) is a powerful, proven diagnostic molecular imaging modality that displays the biological basis of function in the organs and systems of the human body unobtainable through any other means. PET allows the quantitative evaluation of the distribution of several pharmaceuticals in a target area
in vivo
. It is a unique diagnostic imaging technique for measuring the metabolic activity of cells in the human body. PET produces images of the body's basic biochemistry and biological activity in a noninvasive way, combining techniques applied in nuclear medicine with the precise localization achieved by computerized image reconstruction. It is, therefore, a powerful diagnostic test that is having a major impact on the diagnosis and treatment of disease, as well as in patient management.
Vector Quantization
Authors: Enis Cetin A. , Nezih Gerek Omer 
Published: April 2006

AbstractVector quantization (VQ) is a critical step in representing signals in digital form for computer processing. It has various uses in signal and image compression and in classification. If the signal samples are quantized separately, the operation is called “scalar quantization.” Consequently, if the samples are grouped to form vectors, their quantization is called “vector quantization.” Changing the quantization dimension from one (for scalar) to multiple (for vectors) has many important mathematical and practical implications. VQ produces indices that represent the vector formed by grouping samples. The output index, which is an integer, has little or no physical relation with the vector it is representing, which is formed by grouping real or complex valued samples. The word “quantization” in VQ comes from the fact that similar vectors are grouped together and represented by the same index. Therefore, many distinct vectors on the multidimensional space are quantized to a single vector that is represented by the index. The number of distinct indices defines the number of quantization levels. Assigning indices to a number of vectors has practical applications in compression and classification. This chapter presents the general layout of the VQ operation, introduces VQ design and optimality conditions, and gives examples about compression and classification applications.
Venous Air Embolism: Detection via Wavelet Transform
Authors: Aydin Nizamettin 
Published: April 2006

AbstractVenous air embolism (VAE) is a potentially lethal complication of surgical procedures in which the operative site is above the right atrium or gas is forced under pressure into a body cavity. Although it is associated with neurosurgery, VAE is also a potential complication of laparoscopic, pelvic, and orthopedic procedures. Therefore, it is important to detect and treat venous air entrainment. A number of techniques for monitoring VAE exist. Asymptomatic circulating emboli can be detected by Doppler ultrasound, which is a noninvasive method for monitoring emboli. Circulating embolus produces an easily identifiable characteristic sound. Embolic Doppler ultrasound signals are short‐duration transient‐like signals. The fast Fourier transform (FFT) is widely used to process embolic Doppler signals. However, the FFT is not ideally suited to analysis of short‐duration embolic signals because of an inherent trade‐off between temporal and frequency resolution. Alternatively, the wavelet transform is an ideal method for analysis and detection of such signals by optimizing time‐frequency resolution.
Assembly of Wiseana Iridovirus: Viruses for Colloidal Photonic Crystals
Authors: Juhl S. B. , Chan E. P. , Ha Y.‐H. , Maldovan M. , Brunton J. , Ward V. , Dokland T. , Kalmakoff J. , Farmer B. , Thomas E. L. , Vaia R. A. 
Published: April 2006

AbstractIn vitro assembly of Wiseana iridescent virus (WIV) yields iridescent pellets and films with structural color more vivid than in the native insect. WIV is icosahedral in shape, 140 nm in diameter, with 30 nm long fibrils attached to the outer surface, and exhibits a surface charge ca. 1/6th that of a comparable polymer colloid. The low surface charge and tethered chains on the virus surface allow the facile modification of the interparticle distance. Directed sedimentation yields predominantly an amorphous liquid‐like packing of the virus. Such samples exhibit a broad reflection band that is angle independent and for which the broad maximum can be reversibly shifted from blue towards red with increased hydration. Slow sedimentation and flow‐assisted assembly methods produce thin films with a polycrystalline morphology that exhibit narrower, more intense reflectivity peaks, which are hydration and angle dependent. This study points toward the potential of viral particles for photonic crystals where their unique structural features (icosahedral symmetry, extreme monodispersity, precise surface functionalization, and tethered surface chains of low surface‐charge density) may lead to superior control of optical properties of their assembled arrays.
High‐Performance Organic Light‐Emitting Diodes Based on Intramolecular Charge‐Transfer Emission from Donor–Acceptor Molecules: Significance of Electron‐ Donor Strength and Molecular Geometry
Authors: Kulkarni A. P. , Kong X. , Jenekhe S. A. 
Published: April 2006

AbstractOrganic light‐emitting diodes based on intramolecular‐charge‐transfer emission from two related donor–acceptor (D–A) molecules, 3,7‐[bis(4‐phenyl‐2‐quinolyl)]‐10‐methylphenothiazine (BPQ‐MPT) and 3,6‐[bis(4‐phenyl‐2‐quinolyl)]‐9‐methylcarbazole (BPQ‐MCZ), were found to have electroluminescence (EL) efficiencies and device brightnesses that differ by orders of magnitude. High brightness (> 40 000 cd m–2) and high efficiency (21.9 cd A–1, 10.8 lm W–1, 5.78 % external quantum efficiency (EQE) at 1140 cd m–2) green EL was achieved from the BPQ‐MPT emitter, which has its highest occupied molecular orbital (HOMO) level at 5.09 eV and a nonplanar geometry. In contrast, diodes with much lower brightness (2290 cd m–2) and efficiency (1.4 cd A–1, 0.66 lm W–1, 1.7 % EQE at 405 cd m–2) were obtained from the BPQ‐MCZ emitter, which has its HOMO level at 5.75 eV and exhibits a planar geometry. Compared to BPQ‐MCZ, the higher‐lying HOMO level of BPQ‐MPT facilitates more efficient hole injection/transport and a higher charge‐recombination rate, while its nonplanar geometry ensures diode color purity. White EL was observed from BPQ‐MCZ diodes owing to a blue intramolecular charge‐transfer emission and a yellow–orange intermolecular excimer emission, enabled by the planar molecular geometry. These results demonstrate that high‐performance light‐emitting devices can be achieved from intramolecular charge‐transfer emission, while highlighting the critical roles of the electron‐donor strength and the molecular geometry of D–A molecules.
Interference of programmed electromagnetic stimulation with pacemakers and automatic implantable cardioverter defibrillators
Authors: Gwechenberger Marianne , Rauscha Friedrich , Stix Günter , Schmid Gernot , Strametz‐Juranek Jeanette 
Published: April 2006

AbstractA commercially available magnetic therapy system, designed for clinical application as well as for private use without medical supervision, was examined with respect to its potential for causing electromagnetic interference with implantable pacemakers (PMs) and automatic implantable cardioverter defibrillators (AICDs). A sample of 15 PMs and 5 AICDs were experimentally investigated. Each of the implants was realistically positioned in a homogeneous, electrically passive torso phantom and exposed to the magnetic fields of the system's applicators (whole body mat, cushion, and bar applicator). The detection thresholds of the implants were programmed to maximum sensitivity and both unipolar as well as bipolar electrode configurations were considered. The evaluation of possible interferences was derived from the internal event storages and pacing statistics recorded by the implants during exposure. Any “heart activity” recorded by the implants during exposure was interpreted as a potential interference, because the implant obviously misinterpreted the external interference signal as a physiological signal. Only cases without any recorded “heart activity” and with nominal pacing rates (as expected from the program parameter settings) of the implants were rated as “interference‐free.” Exposure to the whole body mat (peak magnetic induction up to 265 µT) did not show an influence on PMs and AICD in any case. The cushion applicator at the highest field intensity (peak magnetic induction up to 360 µT) led to atrial sensing defects in four PM models with unipolar electrode configuration. Under bipolar electrode configuration no disturbances occurred. The bar applicator led to sensing problems and consecutively reduced pacing rates in all tested PM models under unipolar electrode configuration and maximum field intensity (peak magnetic induction up to 980 µT). Bipolar electrode configuration resolved the problem. The investigated AICDs did not show malfunctions under any investigated condition. In conclusion, the examined PEMF therapy system did not interfere with the investigated implantable cardiac devices with bipolar electrode configuration. However, unipolar electrode configuration in pacemakers seems to be potentially hazardous during application of the examined PEMF therapy system. Bioelectromagnetics 27:365–377, 2006. © 2006 Wiley‐Liss, Inc.
Sodium butyrate‐treated embryonic stem cells yield hepatocyte‐like cells expressing a glycolytic phenotype
Authors: Sharma N.S. , Shikhanovich R. , Schloss R. , Yarmush M.L. 
Published: April 2006

AbstractEmbryonic stem cells serve as a promising technology to obtain specific cell types for a number of biomedical applications. Because traditional techniques, such as embryoid body formation result in a wide array of differentiated cells such as hepatic, neuronal, and cardiac lineages, strategies have been utilized which favor cell‐specific differentiation to generate more uniformity. In the present study, we have investigated the use of sodium butyrate in a monolayer culture configuration to mediate hepatocyte differentiation of murine embryonic stem cells. Several functional assays used to characterize hepatocyte function (viz. urea secretion, intracellular albumin content, cytokeratin 18, and glycogen staining) were used to analyze the differentiating cell population, suggesting the presence of an enriched population of hepatocyte‐like cells. Since mature hepatocytes mediate energy metabolism predominantly through oxidative means as opposed to hepatocyte precursors, which are primarily glycolytic, we have performed a kinetic analysis of glycolytic and functional capacity to characterize the differentiated cells. In conjunction with mitochondrial mass and activity measurements, we show that Na‐butyrate‐mediated differentiated cells mediate energy metabolism predominantly through glycolysis. This metabolic and mitochondrial characterization can assist in evaluating stem cell differentiation and may prove useful in identifying key regulatory molecules in mediating further differentiation. © 2006 Wiley Periodicals, Inc.
Changes in the natural history of nonsmall cell lung cancer (NSCLC)—Comparison of outcomes and characteristics in patients with advanced NSCLC entered in Eastern Cooperative Oncology Group trials before and after 1990
Authors: Wakelee Heather A. , Bernardo Patricia , Johnson David H. , Schiller Joan H. 
Published: April 2006

AbstractBACKGROUNDDemographic factors and treatment regimens were evaluated in relation to differences in outcome between patients with advanced nonsmall cell lung cancer (NSCLC) who were diagnosed and treated on Eastern Cooperative Oncology Group Phase II and III trials from 1981 to 1990 and from 1991 to 2000.METHODSIn this retrospective analysis, 6 advanced NSCLC trials were identified between 1981 and 1990, and 3 trials were identified after 1990. Patient characteristics (n = 3398 patients) and other clinical outcomes were analyzed, including progression‐free survival (PFS) and overall survival (OS).RESULTSPatients who entered on trials after 1990 more likely were women, received a cisplatin‐containing regimen, had a performance status of 0 or 1, had Stage IIIB (vs. Stage IV) disease, had tumors with adenocarcinoma histology, had weight loss ≤10%, and had pulmonary‐only metastases (although more total metastases and brain metastases) compared with patients who were diagnosed before 1990. OS was longer post‐1990 than pre‐1990 (8.2 months vs. 5.8 months pre‐1990), and PFS was longer post‐1990 (3.5 months vs. 2.6 months pre‐1990; P<.001 for both). In addition, the median interval from the date of disease progression to death increased by nearly 62% in the later decade.CONCLUSIONSImproved survival in more recent NSCLC trials was explained in part by the enrollment of patients with more favorable prognostic factors. A change in the natural history of the disease was reflected by some of these changes, including increased numbers of women with the disease and changes in the patterns of metastases. Changes in eligibility criteria also accounted for some improvements in prognostic factors and improved second line therapies in the later decade. Thus, the survival improvements are likely to be multifactorial, with improved therapies also playing a major role. Cancer 2006. © 2006 American Cancer Society.
Long‐term memory colors of Korean and Hungarian observers
Authors: Tarczali Tünde , Park Du‐Sik , Bodrogi Peter , Kim Chang Yeong 
Published: April 2006

AbstractLong‐term memory colors have been discussed extensively in the literature but previous articles focused on reflecting color samples. In this work, we studied six important long‐term memory colors, skin (both Caucasian and Oriental), green grass, blue sky, deciduous foliage, orange, and banana, in the viewing situation of a self‐luminous color monitor, for two different observer groups, Koreans and Hungarians. We quantified the long‐term memory colors of both observer groups in terms of CIE L*,a*,b* values, in a given viewing situation, and estimated interobserver variability. We used a comprehensive psychophysical experimental methodology including both the method of constant stimuli and the method of adjustment. In many cases, we found significant differences (t tests, P < 0.05) between the Korean and the Hungarian long‐term memory colors. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 176–183, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20192
Recognized visual space of illumination: No simultaneous color contrast effect on light source colors
Authors: Cunthasaksiri Prasit , Shinoda Hiroyuki , Ikeda Mitsuo 
Published: April 2006

AbstractPrevious study [Cunthasaksiri et al., Color Res Appl 2004;29:255–260] showed that simultaneous color contrast (SCC) of an achromatic center‐chromatic surround configuration is a result of a cognitive process where color appearance of the center stimulus is determined in relation to a cortical representation of illuminant for a space or recognized visual space of illumination (RVSI) derived from the contiguous surround. Based on the same basis, we further examined the other characteristic of SCC in which it is imperceptible at relatively high stimulus luminance. It was thought that at this luminance the stimulus possibly appears as a light source where its color appearance is irrelevant to the RVSI. This is because the visual system has learned and adopted the fact that light from an illuminated surface includes the attributes of both illumination and surface reflectance whereas light from a light source is not contaminated. As a result, it could be hypothesized that SCC would not manifest in the light source mode. Observers adjusted a variable luminance achromatic stimulus under four chromatic illuminant conditions (from greenish to whitish) for imperceptible SCC threshold (LT‐noSCC) and light source threshold (LT‐ls). The results showed that first LT‐noSCC remained under LT‐ls under all illuminant conditions, implying thatno SCC occurs in light source mode. Second, neither the highest strength of SCC nor the luminance ratio (Ltest/Lsurround) explains LT‐noSCC. It suggested that the RVSI determines LT‐noSCC. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 184–190, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20207
Taking the footing of a neutral mediator
Authors: Heisterkamp Brian L. 
Published: April 2006

AbstractThis study employs conversation analysis as a method for examining conversational footing in order to achieve mediator neutrality in a court‐sanctioned mediation program. Data for the study are video recordings of actual mediation sessions. Participants include volunteer mediators and disputants who filed small claims cases at a county justice court. As first described by Goffman, conversational footing describes the various degrees of participation that interactants can have in relation to their own remarks.
Mediating in your pajamas: The benefits and challenges for ODR practitioners
Authors: Raines Susan S. 
Published: April 2006

AbstractMany alternative dispute resolution (ADR) professionals remain skeptical of on‐line dispute resolution (ODR) out of a belief that the cold, impersonal realm of cyberspace cannot adequately accommodate human emotions and meet the needs of disputants as fully as face‐to‐face ADR processes. This essay discusses how emotions and cognitive limitations influence the mediation process on‐line, possible methods by which ODR neutrals may address human needs, and some of the challenges and rewards experienced by ODR practitioners as they use technology to deliver traditional ADR services.
Accreditation of on‐line dispute resolution practitioners
Authors: Tyler Melissa Conley , Bornstein Jackie 
Published: April 2006

AbstractThe incorporation of ODR into the practice of dispute resolution creates the need to address issues of accreditation such as the qualifications of practitioners and standards of practice for resolving disputes on‐line. This article outlines models for accrediting practitioners, including case studies of accreditation systems introduced by ODR providers, and the impact such models may have on the emerging field of ODR. The article is based on research conducted for the Department of Justice Victoria (Conley Tyler, Bornstein, and Bretherton, 2004).
The study of quick download mechanism in an infrastructural wireless environment
Authors: Shin Haw‐Yun , Wu Jean‐Lien C. 
Published: April 2006

AbstractFrequent handoff consumes a lot of system capability and signalling resources in a mobile system. In this paper, we present download mechanisms in mobile systems or broadcast systems to support data users to receive the whole packet in time before moving out of the coverage area. Three download strategies: Quick Download using Multi‐channel (QDM) scheme, Prior Download using Single channel (PDS) scheme and the Quit Download (QUD) scheme are proposed in this study where the efficiencies of the three strategies are compared with the one without particular treatment. Some significant estimations such as the percentage of handoff data users having completed service before leaving the cell, the mean waiting time of non‐handoff data users, and the blocking probability of data users are analysed and compared. The numerical results show that, the QDM strategy is most efficient in reducing the handoff rate, the QUD strategy can assure the waiting time of non‐handoff data users and the PDS strategy can keep the handoff rate constant at light and heavy voice load. Furthermore, various number of guard channels for data users are evaluated in terms of data and voice performance based on various download strategies. Copyright © 2006 John Wiley & Sons, Ltd.
Proxy‐based failure detection in multimedia streaming environments
Authors: Jeon Seongkwu , Lee Jongmin , Cha Hojung , Ha Rhan 
Published: April 2006

AbstractThis paper presents an effective failure‐detection mechanism called the ‘dynamic threshold,’ which has specifically developed for use with multimedia streaming applications. Compared to the conventional failure‐detection methods, which normally use a fixed threshold to detect a server failure, the proposed mechanism detects the failure in an effective and timely manner by using a dynamically adjusted timeout value upon which queries are sent to suspected streaming servers running in a dynamic network environment. The failover mechanism based on the dynamic threshold was implemented in a real streaming environment. The empirical results show that the dynamic threshold mechanism performs better than the conventional method in terms of timeliness, with comparable accuracy. Copyright © 2006 John Wiley & Sons, Ltd.
Morphogenetic adaptation of the looping embryonic heart to altered mechanical loads
Authors: Nerurkar Nandan L. , Ramasubramanian Ashok , Taber Larry A. 
Published: April 2006

AbstractThe biophysical mechanisms that drive and regulate cardiac looping are not well understood, but mechanical forces likely play a central role. Previous studies have shown that cardiac torsion, which defines left–right directionality, is caused largely by forces exerted on the heart tube by a membrane called the splanchnopleure (SPL). Here we show that, when the SPL is removed from the embryonic chick heart, torsion is initially suppressed. Several hours later, however, normal torsion is restored. This delayed torsion coincides with increased myocardial stiffness, especially on the right side of the heart. Exposure to the myosin inhibitor Y‐27632 suppressed both responses, suggesting that the delayed torsion is caused by an abnormal cytoskeletal contraction. This hypothesis is supported further by computational modeling. These results suggest that the looping embryonic heart has the ability to adapt to changes in the mechanical environment, which may play a regulatory role during morphogenesis. Developmental Dynamics 235:1822–1829, 2006. © 2006 Wiley‐Liss, Inc.
Predictable mosaic transgene expression in ascidian embryos produced with a simple electroporation device
Authors: Zeller Robert W. , Virata Michael J. , Cone Angela C. 
Published: April 2006

AbstractTwo customized electroporators were specifically designed for creating transgenic ascidian embryos. These electroporators were simple to build, inexpensive, and produced transgenic embryos with efficiencies that equaled or rivaled commercially available machines. A key design feature of these machines resulted in the generation of consistent electroporation pulses providing repeatability between experiments. These devices were used to optimize experimental parameters allowing for the creation of transient transgenic embryos with predictable patterns of mosaic transgene expression. We used these new electroporators to examine the expression of two different fluorescent protein reporter genes with regard to embryonic cell lineage. In general, transgene expression followed the embryonic cell lineage and coelectroporated transgenes were always expressed in the same embryonic cells. Our analysis also indicated that, during development, transgenes could be lost from embryonic cells, suggesting that transgenes may be present in extrachromosomal arrays, as has been observed in other organisms. Our new electroporator designs will allow ascidian researchers to inexpensively produce transgenic ascidians and should prove useful for adapting the electroporation technique to other marine embryo systems. Developmental Dynamics 235:1921–1932, 2006. © 2006 Wiley‐Liss, Inc.