bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust damping control of power oscillation incorporating parametric resonance
Authors: Watanabe Takao , Ohishi Junichi , Yasuda Keiichiro 
Published: October 2002

AbstractIn this paper we consider a damping control of low‐frequency oscillations in an electric power system. On the basis of the hypothesis that an auto‐parametric resonance model can explain a power oscillation, we propose a new model for a robust damping control, by which the system maintains stability even if some auto‐parametric resonance happens. With this model, we can express a parametric variation of a principal oscillation mode and a class of uncertainties which cover neglected dynamics. Since the model has a certain structure of uncertain parameters, we design a robust controller via µ‐synthesis. The robust controller which can be obtained from the presented design strategy has the property that the control performances are more sophisticated in comparison to controllers designed with other existing methods based on the H∞ control. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 42–49, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10069
Turn‐off scheme of thyristor switches for network reconfiguration in FRIENDS
Authors: Hara Ryoichi , Kita Hiroyuki , Tanaka Eiichi , Hasegawa Jun , Iyoda Isao 
Published: October 2002

AbstractThe authors have proposed FRIENDS as a concept of the future electric power system. In order to realize FRIENDS, it is necessary to design the concrete interior structure and control scheme of the Quality Control Center (QCC) which is to be installed between distribution substation and customers. Hybrid‐type transfer switches are assumed to be installed on the high‐voltage side of the QCC to realize network reconfiguration. Some devices for handling power quality are also assumed to be installed on the low‐voltage side to realize customized power quality.In this paper, a novel control scheme for shutoff of the thyristor switches by the power quality handling devices is proposed and the effectiveness of the proposed scheme is investigated through momentary analysis using PSCAD/EMTDC. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 32–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10077
Design study of a high‐temperature superconducting transformer
Authors: Nagasawa Toru , Yamaguchi Mitsugi , Fukui Satoshi 
Published: October 2002

AbstractMany research and development projects on high‐temperature superconducting apparatus such as a transformer, fault current limiter, and cable are being actively pursued in the power field as a result of performance improvement of Bi silver sheath high‐temperature superconducting (HTS) wire. HTS transformers are considered to be among the most promising applications in view of efficiency improvement, the interface with cryogenic cable and normal temperature devices, incombustibility, overload capability, the function as a reactor, and the possibility of use as a fault current limiter. The necessary technical development items of an HTS transformer in order to achieve performance superior to conventional devices are examined. For this purpose, three‐phase 66‐kV 100‐MVA transformers were designed for the comparison of an HTS transformer and a conventional one with oil cooling. The desirable development items are an HTS wire current density of about 40 A/mm2, an allowable winding strain of about 0.5%, a percent impedance of 7.5%, an air gap flux density of about 0.3 T, and AC losses of about 0.3 W/km‐A. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 25–31, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10087
Evaluation of a power system stable region based on Hopf bifurcation theory
Authors: Watanabe Masayuki , Mitani Yasunori , Tsuji Kiichiro 
Published: October 2002

AbstractA power system is a dynamic system, which includes several kinds of nonlinear elements. Transient stability is a typical example originating in the nonlinearity of power swing. On the other hand, use of the nonlinear analysis method based on Hopf bifurcation theory reveals the existence of a limit cycle around an operating point and the stability of the limit cycle. This paper evaluates power system global stability formed by an unstable limit cycle. The limit cycle mainly results from the excitation control. Therefore, it is important to consider the effect of flux linkage change in the field winding in addition to the δ‐ω variables. This paper presents a method of calculating the correct stability boundary associated with an unstable limit cycle. Some numerical results using a model power system demonstrate the accuracy of the method. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 16–24, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10104
Extragenic suppressors of a dominant masculinizing her‐1 mutation in C. elegans identify two new genes that affect sex determination in different ways
Authors: Manser James , Wood William B. , Perry Marc D. 
Published: October 2002

AbstractSummary: The her‐1 regulatory switch gene in C. elegans sex determination is normally active in XO animals, resulting in male development, and inactive in XX animals, allowing hermaphrodite development. The her‐1(n695gf) mutation results in the incomplete transformation of XX animals into phenotypic males. We describe four extragenic mutations that suppress the masculinized phenotype of her‐1(n695gf) XX. They define two previously undescribed genes, sup‐26 and sup‐27. All four mutations exhibit semidominance of suppression and by themselves have no visible effects on sex determination in otherwise genotypically wild‐type XX or XO animals. Analysis of interactions with mutations in the major sex‐determining genes show that sup‐26 and sup‐27 influence sex determination in fundamentally different ways. sup‐26 appears to act independently of her‐1 to negatively modulate synthesis or function of tra‐2 in both XX and XO animals. sup‐27 may play a role in X‐chromosome dosage compensation and influence sex determination indirectly. genesis 34:184–195, 2002. © 2002 Wiley‐Liss, Inc.
Rapid in vivo labeling of identified zebrafish neurons
Authors: Downes Gerald B. , Waterbury Julie A. , Granato Michael 
Published: October 2002

AbstractWe report a simple and rapid method to label individual neurons in live zebrafish embryos and to examine their gene expression profiles. Injection of plasmid DNA encoding an α‐tubulin promotor driving GFP expression results in mosaic embryos containing a limited number of GFP‐positive neurons. Labeled neurons express GFP in their soma and axon, providing the opportunity to analyze pathfinding behaviors of identified neurons in vivo. Moreover, the presence of only a small subset of GFP tagged neurons permits the rapid anatomical identification of these neurons based on soma position and axonal trajectory. Analysis of injected embryos reveals that most, if not all, spinal cord cell types and many other neuronal cell types elsewhere in the nervous system can be GFP tagged. Finally, by combining GFP labeling of individual neurons with fluorescent in situ hybridization, we demonstrate the potential of this method to elucidate gene expression patterns at single cell resolution. genesis 2:196–202, 2002. © 2002 Wiley‐Liss, Inc.
Lamprey as an evo‐devo model: Lessons from comparative embryology and molecular phylogenetics
Authors: Kuratani Shigeru , Kuraku Shigehiro , Murakami Yasunori 
Published: October 2002

AbstractLamprey, the living jawless vertebrate, has been regarded as one of the most primitive groups of vertebrates. The evolutionary phylogenetic position of the lamprey promises to provide hints about the origin of the vertebrate genome as well as the origin of the body plan, a part of which may be written in the genome. Since the lamprey split from the gnathostome lineage early in the history of vertebrates, the shared developmental mechanisms in lampreys and gnathostomes can be regarded as possessed by the hypothetical common ancestor of these animals, whereas the gnathostome‐specific developmental mechanisms that are absent from lampreys indicate that they are relatively new, added to the developmental program only after the split of gnathostomes. Thus, the sequential establishment of the gnathostome body plan is inherently related to the history of genomic duplication events. In this review, recent molecular developmental and evolutionary molecular research on the living lampreys are summarized and discussed, taking vertebrate comparative morphology and embryology into consideration. genesis 34:175–183, 2002. © 2002 Wiley‐Liss, Inc.
Abnormalities in cloned mice are not transmitted to the progeny
Authors: Shimozawa Nobuhiro , Ono Yukiko , Kimoto Shingo , Hioki Kyoji , Araki Yoshihiko , Shinkai Yoichi , Kono Tomohiro , Ito Mamoru 
Published: October 2002

AbstractCloned animals suffer a wide range of severe fetal and placental malformations. Whether these malformations arise from insufficient epigenetic modifications or mutations has not yet been determined. To address this question, we examined siblings from both cloned XO and XY parents. These parents, which exhibited hypertrophic placentas, increased body weights, and open eyelids at birth, were created from the same ES cell sublines. The siblings from all three cloned pairs showed normal body and placenta weights and no open eyelids at birth. The results clearly showed that the phenotypic abnormalities seen in cloned mice were not transmitted to the progeny, a finding that suggests that abnormalities in cloned mice are responsible for insufficient epigenetic modifications/reprogramming. genesis 2:203–207, 2002. © 2002 Wiley‐Liss, Inc.
ER‐based double icre fusion protein allows partial recombination in forebrain
Authors: Casanova Emilio , Fehsenfeld Sandra , Lemberger Thomas , Shimshek Derya R. , Sprengel Rolf , Mantamadiotis Theo 
Published: October 2002

AbstractHere we describe the generation of a new tamoxifen‐inducible double Cre fusion protein generated by fusing two ERT2 domains onto both ends of the iCre recombinase (a codon improved Cre recombinase). This Cre fusion protein (ERiCreER) had a twofold increased activity in cell culture assays than the previously described MerCreMer Cre double fusion protein. ERiCreER was targeted to the brain by placing it under the control of the promoter from the CamKIIα gene using a 170 kb BAC. The fusion protein was detected in hippocampus, cortex, striatum, thalamus, and hypothalamus but not in cerebellum. The ERiCreER was cytoplasmatic in the absence of tamoxifen and translocated into the nucleus upon tamoxifen administration. The activity of the ERiCreER was tested in vivo by mating the CamKIIα ERiCreER transgenic line with mice harbouring exon 10 of the CREB gene flanked by two LoxP sites. In the absence of tamoxifen, no background activity was detected in mice older than 6 months. After tamoxifen administration, most if not all of the ERiCreER fusion protein translocated from the cytoplasm to the nucleus; however, only 5–10% of the “floxed” CREB allele was recombined. Recombination was also visualised at the cellular level by following the upregulation of the CREM protein, which corresponds precisely with CREB loss/recombination. Unlike in other tissues (Sohal et al., 2001; Tannour‐Louet et al., 2002), it appears that in brain, although ERiCreER can bind tamoxifen, the Cre‐recombinase cannot be fully activated. genesis 34:208–214, 2002. © 2002 Wiley‐Liss, Inc.
Visualization of rod photoreceptor development using GFP‐transgenic zebrafish
Authors: Hamaoka Takanori , Takechi Masaki , Chinen Akito , Nishiwaki Yuko , Kawamura Shoji 
Published: October 2002

AbstractSummary: Zebrafish retina contains five morphologically distinct classes of photoreceptors, each expressing a distinct type of opsin gene. Molecular mechanisms underlying specification of opsin expression and differentiation among the cell types are largely unknown. This is partly because mutants affected with expression of a particular class of opsin gene are difficult to find. In this study we established the transgenic lines of zebrafish carrying green fluorescent protein (GFP) gene under the 1.1‐kb and 3.7‐kb upstream regions of the rod‐opsin gene. In transgenic fish, GFP expression initiated and proceeded in the same spatiotemporal pattern with rod‐opsin gene. The retinal section from adult transgenic fish showed GFP expression throughout the rod cell layer. These results indicate that the proximal 1.1‐kb region is sufficient to drive gene expression in all rod photoreceptor cells. These transgenic fish should facilitate screening of mutants affected specifically with rod‐opsin expression or rod cell development by visualization of rod cells by GFP. genesis 34:215–220, 2002. © 2002 Wiley‐Liss, Inc.
Statistical parametric mapping of LORETA using high density EEG and individual MRI: Application to mismatch negativities in Schizophrenia
Authors: Park Hae‐Jeong , Kwon Jun Soo , Youn Tak , Pae Ji Soo , Kim Jae‐Jin , Kim Myung‐Sun , Ha Kyoo‐Seob 
Published: October 2002

AbstractWe describe a method for the statistical parametric mapping of low resolution electromagnetic tomography (LORETA) using high‐density electroencephalography (EEG) and individual magnetic resonance images (MRI) to investigate the characteristics of the mismatch negativity (MMN) generators in schizophrenia. LORETA, using a realistic head model of the boundary element method derived from the individual anatomy, estimated the current density maps from the scalp topography of the 128‐channel EEG. From the current density maps that covered the whole cortical gray matter (up to 20,000 points), volumetric current density images were reconstructed. Intensity normalization of the smoothed current density images was used to reduce the confounding effect of subject specific global activity. After transforming each image into a standard stereotaxic space, we carried out statistical parametric mapping of the normalized current density images. We applied this method to the source localization of MMN in schizophrenia. The MMN generators, produced by a deviant tone of 1,200 Hz (5% of 1,600 trials) under the standard tone of 1,000 Hz, 80 dB binaural stimuli with 300 msec of inter‐stimulus interval, were measured in 14 right‐handed schizophrenic subjects and 14 age‐, gender‐, and handedness‐matched controls. We found that the schizophrenic group exhibited significant current density reductions of MMN in the left superior temporal gyrus and the left inferior parietal gyrus (P < 0. 0005). This study is the first voxel‐by‐voxel statistical mapping of current density using individual MRI and high‐density EEG. Hum. Brain Mapping 17:168–178, 2002. © 2002 Wiley‐Liss, Inc.
Changes in neural circuitry of language before and after treatment of major depression
Authors: Abdullaev Yalçin , Kennedy Barbara L. , Tasman Allan 
Published: October 2002

AbstractLanguage tasks requiring semantic analysis of word meaning activate distinct brain areas including the anterior cingulate gyrus at about 200 msec after the stimulus onset, the left lateral prefrontal cortex at about 250 msec, and the left temporo‐parietal (Wernicke's) area at 500–600 msec. Reading the same words activate the insula around 800 msec and left occipital cortex around 200 msec stronger than the semantic analysis in normal subjects. Many of these brain areas also show abnormal activity in resting state in patients with major unipolar depression. We measured 128‐channel event‐related brain potentials (ERPs) and statistical probability mapping in the use generation task carried out with single visual nouns to explore the topography and time course of these cortical activations related to semantic processing in 11 patients with major unipolar depression before and 8 weeks after treatment with the selective serotonin reuptake inhibitor (SSRI) citalopram. Before treatment in depressed state, the time course for the left prefrontal cortex activation did not show slowing, but was accompanied by the right prefrontal activation with a similar time course. The left posterior temporo‐parietal activation appeared later than in normals. Treatment was accompanied by the complete elimination of the right prefrontal activation in the same use generation task. Time course of the posterior left temporo‐parietal area showed a trend toward normalization. Insula‐related activation in reading task was not seen in depressed state, but was evident in the same patient group after the depression has lifted, presumably as a result of treatment with citalopram. Hum. Brain Mapping 17:156–167, 2002. © 2002 Wiley‐Liss, Inc.
Validating the boundary element method for forward and inverse EEG computations in the presence of a hole in the skull
Authors: Oostenveld Robert , Oostendorp Thom F. 
Published: October 2002

AbstractHoles in the skull may have a large influence on the EEG and ERP. Inverse source modeling techniques such as dipole fitting require an accurate volume conductor model. This model should incorporate holes if present, especially when either a neuronal generator or the electrodes are close to the hole, e.g., in case of a trephine hole in the upper part of the skull. The boundary element method (BEM) is at present the preferred method for inverse computations using a realistic head model, because of its efficiency and availability. Using a simulation approach, we have studied the accuracy of the BEM by comparing it to the analytical solution for a volume conductor without a hole, and to the finite difference method (FDM) for one with a hole. Furthermore, we have evaluated the influence of holes on the results of forward and inverse computations using the BEM. Without a hole and compared to the analytical model, a three‐sphere BEM model was accurate up to 5–10%, while the corresponding FDM model had an error <0.5%. In the presence of a hole, the difference between the BEM and the FDM was, on average, 4% (1.3–11.4%). The FDM turned out to be very accurate if no hole is present. We believe that the difference between the BEM and the FDM represents the inaccuracy of the BEM. This inaccuracy in the BEM is very small compared to the effect that holes can have on the scalp potential (up to 450%). In regard to the large influence of holes on forward and inverse computations, we conclude that holes in the skull can be treated reliably by means of the BEM and should be incorporated in forward and inverse modeling. Hum. Brain Mapping 17:179–192, 2002. © 2002 Wiley‐Liss, Inc.
Fast robust automated brain extraction
Authors: Smith Stephen M. 
Published: October 2002

AbstractAn automated method for segmenting magnetic resonance head images into brain and non‐brain has been developed. It is very robust and accurate and has been tested on thousands of data sets from a wide variety of scanners and taken with a wide variety of MR sequences. The method, Brain Extraction Tool (BET), uses a deformable model that evolves to fit the brain's surface by the application of a set of locally adaptive model forces. The method is very fast and requires no preregistration or other pre‐processing before being applied. We describe the new method and give examples of results and the results of extensive quantitative testing against “gold‐standard” hand segmentations, and two other popular automated methods. Hum. Brain Mapping 17:143–155, 2002. © 2002 Wiley‐Liss, Inc.
Neural implementation of response selection in humans as revealed by localized effects of stimulus–response compatibility on brain activation
Authors: Schumacher Eric H. , D'Esposito Mark 
Published: October 2002

AbstractResponse selection, which involves choosing representations for appropriate motor behaviors given one's current situation, is a fundamental mental process central to a wide variety of human performance, yet the neural mechanisms underlying this mental process remain unclear. Research using nonhuman primates implicates ventral prefrontal and lateral premotor cortices in this process. In contrast, human neuroimaging research also highlights the role of dorsal prefrontal, anterior cingulate, and superior parietal cortices in response selection. This inconsistency may stem from the difficulty of isolating response selection within the constraints of cognitive subtraction methodology utilized in neuroimaging. We overcome this limitation by using an experimental procedure designed to selectively influence discrete mental processing stages and analyses that are less reliant on the assumptions of cognitive subtraction. We varied stimulus contrast to affect stimulus encoding and stimulus–response compatibility to affect response selection. Brain activation data suggest processing specific to response selection in superior parietal and dorsal prefrontal cortices, and not ventral prefrontal cortex. Anterior cingulate and lateral premotor cortices may also be involved in response selection, or these regions may mediate other response processes. Hum. Brain Mapping 17:193–201, 2002. © 2002 Wiley‐Liss, Inc.
Cortical and subcortical networks underlying syncopated and synchronized coordination revealed using fMRI
Authors: Mayville Justine M. , Jantzen Kelly J. , Fuchs Armin , Steinberg Fred L. , Kelso J.A. Scott 
Published: October 2002

AbstractInherent differences in difficulty between on the beat (synchronization) and off the beat (syncopation) coordination modes are well known. Synchronization is typically quite easy and, once begun, may be carried out with little apparent attention demand. Syncopation tends to be difficult, even though it has been described as a simple, phase‐shifted version of a synchronized pattern. We hypothesize that syncopation, unlike synchronization, is organized on a cycle‐by‐cycle basis, thereby imposing much greater preparatory and attentional demands on the central nervous system. To test this hypothesis we used fMRI to measure the BOLD response during syncopation and synchronization to an auditory stimulus. We found that the distribution of cortical and subcortical areas involved in intentionally coordinating movement with an external metronome depends on the timing pattern employed. Both synchronized and syncopated patterns require activation of contralateral sensorimotor and caudal supplementary motor cortices as well as the (primarily ipsilateral) cerebellum. Moving off the beat, however, requires not only additional activation of the cerebellum but also the recruitment of another network comprised of the basal ganglia, dorsolateral premotor, rostral supplementary motor, prefrontal, and temporal association cortices. No areas were found to be more active during synchronization than syncopation. The functional role of the cortical and subcortical regions areas involved in syncopation supports the hypothesis that whereas synchronization requires little preparation and monitoring, syncopated movements are planned and executed individually on each perception–action cycle. Hum. Brain Mapping 17:214–229, 2002. © 2002 Wiley‐Liss, Inc.