bluuebunny/crossref_metadata_2025 huggingface dataset:
Bahnbestimmung für den visuellen Doppelstern ADS 5400 AB = 12 Lyncis
Authors: Brosche P.
Published: July 2007

Das Untersystem AB des dreifachen Sternes ADS 5400 wird einer Bahnbestimmung unterzogen, wobei eine wesentliche Verbesserung gegenüber der einzigen vorherigen Bahnbestimmung von GORE erzielt wird.
Lichtelektrische Messungen von Beta Cephei
Authors: Jackisch G.
Published: July 2007

Die Änderung der Gesamthelligkeit von β Cephei wurde 1951 in 13 Nächten lichtelektrisch beobachtet. Die Beobachtungsergebnisse lassen sich durch die von STRUVE, MCNAMARA, KUNG und BEYMER abgeleitete Periode darstellen, deren Länge für den Beobachtungszeitraum P = 0d.1904884 ist. Andere Perioden brachten keine Verbesserung. Die Amplitude des Lichtwechsels beträgt 0m.04. Sie ist nur ein Mittelwert über den Beobachtungszeitraum und unterliegt Änderungen bis zu etwa ± 0m.03.
Bahnverbesserung durch Variationsbahnen für 8 Doppelsternsysteme
Authors: d̊ W. Rabe
Published: July 2007

Nach meinen in AN 280.1 mitgeteilten neuen Methoden der Bahnverbesserung werden 8 Systeme bearbeitet. Bei 3 Systemen kommt die allgemeine Methode aus der Tangentialgeschwindigkeit zur Oskulationsepoche zur Anwendung; 5 Systeme werden durch die Spezialmethode der Drehung der Apsidenlinie verbessert. Die allgemeinen Erfahrungen über die Methoden sind einleitend kurz zusammengefaßt.
Über den Zusammenhang zwischen Rotverschiebung und scheinbarer Helligkeit
Authors: Mattig W.
Published: July 2007

Im Rahmen der relativistischen Kosmologie wird für den Fall des verschwindenden kosmologischen Gliedes Λ ein strenger Zusammenhang zwischen der bolometrischen Helligkeit und der Rotverschiebung angegeben. Die sich ergebenden Differenzen gegenüber der bisher benutzten Näherung werden berechnet. Es zeigt sich, daß diese Differenzen bei größeren Beträgen der Rotverschiebung nicht mehr zu vernachlässigen sind.
Physische Beobachtungen von Kometen. X
Authors: Beyer M.
Published: July 2007

Die zwischen 1953 Okt. 6 und 1955 Juli 9 erhaltenen physischen Beobachtungen von 9 Kometen werden als Fortsetzung einer seit 1933 laufenden Serie von Berichten einer planmäßigen Überwachung dieser Himmelskörper mitgeteilt. Es handelt sich vorwiegend um visuelle Beobachtungen der Gesamthelligkeit des Kometenkopfes, um photometrische Messungen der als Kern bezeichneten sternartigen Verdichtung sowie um Bestimmungen des Durchmessers des visuell erkennbaren Teils der Koma. Zur Charakterisierung der Helligkeitsentwicklung wurden die Werte für H0 und n des die Gesamthelligkeit des Kometen in Beziehung zu seinen Abständen von Sonne und Erde darstellenden Ausdrucks mt = H0 + 2.5 n · log r + 5 · log Δ abgeleitet. Die in einigen Fällen vorhandenen, jedoch nicht immer gesicherten sekundären Helligkeitsschwankungen sind auch diesmal den auf die jeweiligen Kometenörter bezogenen Sonnenflecken‐Relativzahlen gegenübergestellt, um etwaige Einflüsse der Sonnenaktivität auf das Kometenleuchten prüfen zu können.

Weitere Beobachtungen beziehen sich auf die Gestalt, Struktur und Richtung der Schweife. Sofern die Richtungen besonders in größeren Sonnenabständen, erheblich vom verlängerten Radiusvektor des Kometen abwichen, blieben, sie doch stets innerhalb des Winkels zwischen diesem und der Richtung des zuletzt zurückgelegten Weges.
Sur le contour des continents terrestres. Influence probable de la Lune
Authors: Boneff N.
Published: July 2007

D'après la théorie de WEGENER les continents terrestres sont en dérive de l'Est à l'Ouest. Les continents se sont déplacés, d'après l'auteur, dans le sens des méridiens comme l'indiquent quelques‐unes de leurs singularités. La „tension méridienne”︁, en rapport à une diminution séculaire de l'aplatissement terrestre, est due en dernier compte à l'action de marée lunaire. Durée probable de l'évolution du système Terre‐Lune.
Zur Entstehung von Gasströmen in engen Doppelsternsystemen. Bemerkungen zu Rechnungen von Z. KOPAL
Authors: Günther O.
Published: July 2007

Ew wird vermutet, daß die spektrographisch beobachteten Gasströme um die Hauptkomponente in den Doppelsternsystemen, die KOPAL als „detached”︁ und „semi‐detached systems”︁ unterscheidet, eine gemeinsame Entstehungsursache haben. Dabei handelt es sich wohl nicht um die von KOPAL untersuchte differentielle Rotation der Nebenkomponente, sondern vielleicht um eine „Protuberanzentätigkeit”︁, wie sie von STRUVE angenommen wird.
The nature of gas streams in close binary systems
Authors: Kopal Zdenêk
Published: July 2007

The aim of the present note is to point out that the hydrogen gas streams circulating in such systems as U Sge or RW Tau must be almost completely ionized; that their macroscopic motions are characterized by REYNOLDS numbers of the order of 109, and the kinematic viscosity of the constituent gas is around 109—1010. As a result, the observed gas flow must inevitably be highly turbulent; and the magnetic fields produced by vortex motion of charged particles may exert an important — if not controlling — influence on the dynamics of such streams.
Beobachtungen der Schweifentwicklung des Kometen 1956 h (AREND‐ROLAND)
Authors: Wenske K.
Published: July 2007

An Hand von Aufnahmeserien in zwei Spektralbereichen werden die Veränderungen der Richtung und der Gestalt des Kometenschweifs beschrieben. Die Ausbildung der Gegenschweife sowie der Formunterschiede im blauen und roten Spektralbereich werden mittels einer Isophotendarstellung untersucht. Eine Aufnahmereihe in der Nacht 1957 April 27/28 gestattete die Ermittlung von Materiebewegung in einem Schweifstrahl.
Effects of overexpression of X‐box binding protein 1 on recombinant protein production in Chinese hamster ovary and NS0 myeloma cells
Authors: Ku Sebastian C.Y. , Ng Daphne T.W. , Yap Miranda G.S. , Chao Sheng‐Hao
Published: July 2007

X‐box binding protein 1 (XBP‐1) is a key regulator of the cellular secretory pathway and unfolded protein response (UPR). It has been shown that the spliced form of XBP‐1, XBP‐1S, functions as a transcription activator and up‐regulates many genes associated with protein secretion and biosynthesis of endoplasmic reticula. Since the production of some recombinant proteins is widely believed to be limited by the secretory capacity of the host cell, an increase in protein production may be achieved by overexpressing XBP‐1S. In this study, the effects of XBP‐1S on the productivity of monoclonal antibody (MAb), interferon γ (IFNγ), and erythropoietin (EPO) are examined in Chinese hamster ovary (CHO) and NS0 cell lines. Results show that XBP‐1S may become a determinative factor only when accumulation of recombinant proteins exceeds the secretory capacity of the host cell. In transient transfection systems where a bottleneck in protein secretion was achieved, overexpression of XBP‐1S improved protein titers by up to 2.5‐fold. In contrast, overexpression of XBP‐1S had no detectable effects on protein productivity of stable cell lines that did not exhibit any secretory bottleneck. We conclude that overexpression of XBP‐1S is an effective strategy in enhancing recombinant protein production when the secretory pathway of the host cell is saturated by high‐level synthesis of recombinant proteins. Biotechnol. Bioeng. 2008;99: 155–164. © 2007 Wiley Periodicals, Inc.
Overexpression of human Raf‐1 enhances radiosensitivity in fission yeast, Schizosaccharomyces pombe
Authors: Lee Michael
Published: July 2007

Recently we isolated Rad24, a 14‐3‐3 homologue, which is essential for DNA damage checkpoint, as a Raf‐1 interacting protein by screening a Schizosaccharomyces pombe (S. pombe) cDNA library. Raf‐1 was also found to recognize Cdc25 that is sequestered and inactivated by Rad24. In the present study, experiments were performed to determine the effect of overexpression of Raf‐1 proteins on asynchronously growing S. pombe cells. The overexpression of Rad24 induced elongated cell morphology and reduction in growth rate, resulting in cell cycle arrest while the overexpression of catalytically active Raf‐1 led to a decrease in cell size at division in S. pombe. However, the active Raf‐1 failed to rescue the growth arrest induced by Rad24 overexpression. In addition, the cells carrying catalytically active Raf‐1 were significantly more radiosensitive than those from a normal control as assessed by ultraviolet sensitivity assay, suggesting that constitutive overproduction of Raf‐1 kinase can revert DNA replication checkpoint arrest caused by UV irradiation. Taken together, these data suggest that Raf‐1 may interfere with the role of Rad24 by competing with Rad24 for binding to Cdc25 in DNA repair, bypassing the checkpoint pathway through Cdc25 activation. Copyright © 2007 John Wiley & Sons, Ltd.
New Hybrid Semiconductor Materials Based on Viologen Salts of Bimetallic Fe–Pt and Fe–Au Carbonyl Clusters: First Structural Characterization of the Diradical π‐Dimer of the Diethylviologen Monocation and EPR Evidence of its Triplet State
Authors: Femoni Cristina , Iapalucci Maria Carmela , Longoni Giuliano , Tiozzo Cristina , Wolowska Joanna , Zacchini Stefano , Zazzaroni Enrico
Published: July 2007

The synthesis, structure, spectroscopic characterization and electrical resistivity of the [EtV]2[Fe4Pt(CO)16], [EtV][Fe3Pt3(CO)15]⋅THF, [EtV][Fe4Au(CO)16]2⋅2 THF (EtV=1,1′‐diethyl‐4,4′‐bipyridilium cation) and [NEt4]2[Fe4Au(CO)16] is reported. The crystal structure of [EtV]2[Fe4Pt(CO)16] is based on infinite stacks of [(EtV).+]2 π‐dimers rotated by 90° and isolated [Fe4Pt(CO)16]2− ions. Within each π‐dimer, the [EtV].+ radical ions are perfectly eclipsed and the distance between their mean planes is 3.275 Å. The EPR spectrum of the solid material at room temperature clearly indicates the presence of a significantly populated triplet state of the π‐dimer, by showing signals both at Δm=1 and Δm=2. The solid‐state structure of [EtV][Fe3Pt3(CO)15]⋅THF is based on the ionic packing of [EtV]2+ and [Fe3Pt3(CO)15]2− ions, inferred from a comparison of their molecular parameters with literature data. Significant electron transfer could have been expected to give [EtV].+[Fe3Pt3(CO)15].− on the basis of their formal redox potentials. In spite of their different stoichiometries, the structures of [EtV][Fe4Au(CO)16]2⋅ 2 THF and [NEt4]2[Fe4Au(CO)16] both contain an isomer of the monoanion [Fe4Au(CO)16]− in solution (previously characterized in the solid state as a [NMe3CH2Ph]2[Fe4Au(CO)16]Cl mixed salt). Resistivity measurements on pellets of powdered samples of the above compounds indicate that their tetrasubstituted ammonium salts, and complex [EtV][Fe4Au(CO)16]2⋅2 THF, largely behave as insulators. However, the [EtV]2[Fe4Pt(CO)16] and [EtV][Fe3Pt3(CO)15]⋅THF samples respectively display resistivities 3 and 4 orders of magnitude less than those of their corresponding ammonium salts and could be classified as semiconductor materials.
Novel Core‐Expanded Rylenebis(Dicarboximide) Dyes Bearing Pentacene Units: Facile Synthesis and Photophysical Properties
Authors: Avlasevich Yuri , Müller Sibylle , Erk Peter , Müllen Klaus
Published: July 2007

Two synthetic routes for the benzannulation in the “bay”‐region of rylenebis(dicarboximide)s leading to new π‐system‐expanded chromophores are described. The first route follows a two‐step approach: Suzuki coupling of bromo‐substituted perylenebis(dicarboximide) with 2‐bromophenylboronic acid, followed by palladium‐catalysed dehydrobromination. The second route is best described as a palladium‐assisted cycloaddition of benzyne, formed in situ, to the bay‐region of the bromo‐substituted rylene core. Two new types of core‐expanded rylene dyes were synthesised: yellow dibenzocoronenebis(dicarboximide)s, absorbing at 490 nm, and a green dinaphthoquaterrylenebis(dicarboximide), which absorbs at 700 nm. These new chromophores are characterised by significant hypsochromic shifts of absorption, compared to their parent rylenebis(dicarboximide)s, excellent photostabilities and high fluorescence quantum yields.
Structural Elucidation of Dendritic Host–Guest Complexes by X‐ray Crystallography and Molecular Dynamics Simulations
Authors: Chang Theresa , Pieterse Koen , Broeren Maarten A. C. , Kooijman Huub , Spek Anthony L. , Hilbers Peter A. J. , Meijer E. W.
Published: July 2007

The multiple monovalent binding of adamantyl–urea poly(propyleneimine) dendrimers with carboxylic acid–urea guests was investigated using molecular dynamics simulations and X‐ray crystallography to better understand the structure and behavior of the dynamic multivalent complex in solution. The results from the two methods are consistent and suggest a preferred molecular picture of this complicated aggregate of multiple components. The guest molecules can bind to the dendrimer in a variety of ways although most involve hydrogen‐bonding interactions between urea groups of the dendrimer with urea and/or carboxylic acid groups of the guest. In addition, acid–base interactions between the carboxylic acid of the guest and the tertiary amine in the interior of the dendritic host are present. Our proposed structure gives important information about the predominant dynamic interactions between the host and guest and illustrates how they fit together and interact with each other.
Liquid chromatographic direct resolution of β‐amino acids on a doubly tethered chiral stationary phase containing NH amide linkage based on (+)‐(18‐crown‐6)‐ 2,3,11,12‐tetracarboxylic acid
Authors: Hyun Myung Ho , Song Yanci , Cho Yoon Jae , Choi Hee Jung
Published: July 2007

A doubly tethered chiral stationary phase (CSP) prepared by bonding (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid to doubly tethered primary aminoalkyl silica gel was used for the resolution of various β‐amino acids. All the β‐amino acids tested were resolved quite well, the separation (α) and the resolution factors (RS) being in the ranges 1.34–2.09 and 2.52–7.45, respectively, with a mobile phase of methanol–water (50:50, v/v) containing 10 mM acetic acid. The chiral recognition efficiency of the doubly‐tethered CSP was found to be generally superior to that of the corresponding singly‐tethered CSP in the resolution of β‐amino acids. The chiral recognition behaviors for the resolution of β‐amino acids on the doubly tethered CSP were examined by varying the type and content of organic and acidic modifiers in the aqueous mobile phase and the column temperature. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
A study of planar chromophores in dichromophoric molecules by circular dichroism spectroscopy
Authors: Stončius Sigitas , Bagdžiūnas Gintautas , Malinauskienė Julė , Butkus Eugenijus
Published: July 2007

A synthesis of a series of enantiomerically pure polycyclic structures derived from (+)‐(1S,5S)‐bicyclo[3.3.1]nonane‐2,6‐dione was accomplished. Molecules containing single or two similar or different chromophores were obtained. Chiroptical properties of the synthesized chiral structures 2–5, and 7 having carbonyl, 1,2‐methylenedioxybenzene, and indole chromophores were studied. The sign of the cotton effect was related to sector rules and the orientation of the planes containing chromophores in dichromophoric molecules possessing 1,2‐methylenedioxybenzene and carbonyl or indole chromophores. Interaction of the chromophores in dichromophoric molecules was examined by CD spectroscopy; however, no direct evidence was obtained. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
The impact of total retrieved lymph nodes on staging and survival of patients with pT3 gastric cancer
Authors: Shen Jia Yun , Kim Sungsoo , Cheong Jae‐Ho , Kim Yong Il , Hyung Woo Jin , Choi Won Hyuk , Choi Seung Ho , Wang Lin Bo , Noh Sung Hoon
Published: July 2007

BACKGROUND.

The incidence of lymph node metastasis is high in patients who have pT3 gastric cancer. However, the impact of total retrieved lymph nodes (tLNs) on staging and survival of these patients is not clear.

METHODS.

For this study, the authors examined 1895 patients with pT3 gastric cancer who underwent surgery at Yonsei University Medical College from January 1987 to June 2000.

RESULTS.

Four hundred sixty of 1895 patients (24.3%) were diagnosed with pT3N0 gastric cancer. Patients who had < 31 tLNs (25th percentile) had less advanced lymph node (N) stage than the other patients (P < .001). Lymph node metastasis had a positive association with the number of tLNs in a logistic regression analysis (P < .001; hazards ratio, 1.014; 95% confidence interval, 1.006–1.021). With a median follow‐up of 61.1 months, the overall 10‐year survival rate (10‐YSR) was 42.8%. Patients with pT3N0 disease who had < 31 tLNs had a 10‐YSR of only 55.4%. Although this 10‐YSR did not differ significantly from the rate for patients with N0 disease who had ≥31 tLNs (65.8%; P = .108), it approached the rate for the N1 group (53.3%; P = .207). In multivariable analyses, the number of tLNs emerged as an independent prognostic predictor in patients with pT3N2 and pT3N3 disease, but not in patients with pT3N0 or pT3N1 disease.

CONCLUSIONS.

Increasing numbers of tLNs may improve the accuracy of staging in patients who have pT3 gastric cancer. Because preoperative lymph node staging is difficult, a thorough lymph node dissection is mandatory in all serosa‐positive patients. Cancer 2007. © 2007 American Cancer Society.
Genetic polymorphisms in DNA base‐excision repair genes ADPRT, XRCC1, and APE1 and the risk of squamous cell carcinoma of the head and neck
Authors: Li Chunying , Hu Zhibin , Lu Jiachun , Liu Zhensheng , Wang Li‐E , El‐Naggar Adel K. , Sturgis Erich M. , Spitz Margaret R. , Wei Qingyi
Published: July 2007

BACKGROUND.

Tobacco smoke contains numerous carcinogens that cause DNA damage, including oxidative lesions that are removed effectively by the base‐excision repair (BER) pathway, in which adenosine diphosphate ribosyl transferase (ADPRT), x‐ray repair cross‐complementing 1 (XRCC1), and apurinic/apyimidinic endonuclease (APE1) play key roles. Genetic variations in the genes encoding for these DNA repair enzymes may alter their functions. Although there have been several studies that generated mixed results on the association between XRCC1 variants and the risk of squamous cell carcinoma of the head and neck (SCCHN), no reported studies have investigated the association between ADPRT and APE1 variants and SCCHN risk.

METHODS.

In a hospital‐based, case‐control study of 830 non‐Hispanic white patients with SCCHN and 854 cancer‐free, matched control participants, the authors genotyped the ADPRT alanine 762 valine (Ala762Val) single‐nucleotide polymorphism (SNP), the XRCC1 arginine 399 glutamine (Arg399Gln) SNP, and the APE aspartic acid 148 glutamic acid (Asp148Glu) SNP and assessed their associations with the risk of SCCHN in multivariate logistic regression models.

RESULTS.

The findings indicated that a significantly decreased risk of SCCHN was associated with the ADPRT 762Ala/Ala genotype (adjusted odds ratio [OR], 0.51; 95% confidence interval [95% CI], 0.27–0.97) and the combined ADPRT 762Ala/Val and Ala/Ala genotypes (OR, 0.79; 95% CI; 0.63–1.00) compared with the ADPRT 762Val/Val genotype, but no altered risk was associated with the XRCC1 Arg399Gln or APE Asp148Glu polymorphisms, and no evidence of interactions was observed between the 3 selected SNPs and age, sex, smoking status, drinking status, or tumor site.

CONCLUSIONS.

The ADPRT Ala762Val polymorphism may play a role in the etiology of SCCHN or in linkage disequilibrium with other untyped protective alleles. Larger studies with more SNPs in the BER genes will be needed to verify these findings. Cancer 2007; 110:867–75. © 2007 American Cancer Society.
Trastuzumab plus vinorelbine or taxane chemotherapy for HER2‐overexpressing metastatic breast cancer: The trastuzumab and vinorelbine or taxane study
Authors: Burstein Harold J. , Keshaviah Aparna , Baron Ari D. , Hart Ronald D. , Lambert‐Falls Rosemary , Marcom P. Kelly , Gelman Rebecca , Winer Eric P.
Published: July 2007

BACKGROUND.

The optimal trastuzumab‐based chemotherapy regimen for HER2‐overexpressing, metastatic breast cancer is not known. The trastuzumab and vinorelbine or taxane (TRAVIOTA) study was a prospective, multicenter, randomized trial that was designed to compare these regimens.

METHODS.

Eligible patients had HER2‐overexpressing, metastatic breast cancer and had received no prior chemotherapy for advanced disease. Patients were randomized 1:1 to receive either trastuzumab with weekly vinorelbine therapy or weekly taxane therapy (paclitaxel or docetaxel at the investigator's choice). Originally planned for 250 patients, the study was closed because of poor accrual with 81 evaluable patients, including 41 patients who received vinorelbine and 40 patients who received taxane.

RESULTS.

Response rates were 51% and 40% for the vinorelbine/trastuzumab arm and the taxane/trastuzumab arm, respectively (Fisher exact test; P = .37). The median time to disease progression was 8.5 months and 6.0 months for the vinorelbine‐ and taxane‐based arms, respectively (log‐rank test; P = .09). Treatment with either regimen generally was well tolerated, yielding comparable rates of neurologic and gastrointestinal toxicity. Vinorelbine‐based treatment was associated with more anemia and neutropenia and with 2 episodes of cardiotoxicity. Taxane‐based therapy was associated with more dermatologic toxicity, myalgias, and fluid retention.

CONCLUSIONS.

Both vinorelbine/trastuzumab and taxane/trastuzumab treatments were active as first‐line therapy for HER2‐positive, metastatic breast cancer and had comparable rates of efficacy and tolerability. The toxicities observed were the result of recognized side effects associated with each of the chemotherapy agents and schedules. These data can inform treatment decision making in this clinical setting. Cancer 2007. © 2007 American Cancer Society.
Role for connexin 26 in metastasis of human malignant melanoma
Authors: Saito‐Katsuragi Mamiko , Asada Hideo , Niizeki Hironori , Katoh Fumitaka , Masuzawa Mikio , Tsutsumi Masahiro , Kuniyasu Hiroki , Ito Akihiko , Nojima Hiroshi , Miyagawa Sachiko
Published: July 2007

BACKGROUND.

Connexins form the intercellular channels of the gap junction and play an integral part in a variety of biological functions, such as maintaining tissue homeostasis, cell growth control, and development. Previously it was demonstrated that the expression of connexin 26 (Cx26) can increase the metastatic potential of mouse melanoma cells. The objective of the study was to investigate the role Cx26 plays in the metastasis of human melanoma cells, focusing on the communication between melanoma cells and endothelial cells.

METHODS.

Immunostaining was used to examine Cx26 expression in the melanoma lesions and in the endothelial cells around the melanoma cell nests. In all, 33 melanomatous tissue samples from 16 patients were studied, as well as nevocellular nevus (NCN) and normal skin samples. Cx26 mRNA and protein expression was also examined in the cultured endothelial cells. A dye‐transfer assay was performed to examine gap junction formation between melanoma cells and endothelial cells.

RESULTS.

Immunohistochemistry demonstrated that Cx26 was clearly expressed by the endothelial cells of the small vessels surrounding the melanoma cell nests as well as the melanoma cells. Cx26 mRNA and protein expression was detected in cultured endothelial cells. In a coculture system with human malignant melanoma cell line (HMY‐1) and endothelial cells (HMVEC), immunohistochemistry indicated Cx26 expression in both types of cells and dye‐transfer assay demonstrated dye‐coupling from HMY‐1 into HMVEC.

CONCLUSIONS.

Cx26 may contribute to the metastasis of melanoma by facilitating communication between melanoma cells and their surrounding endothelial cells. Cancer 2007. © 2007 American Cancer Society.
Organization of the projections from the posterior parietal cortex to the rostral and caudal regions of the motor cortex of the cat
Authors: Andujar Jacques‐Étienne , Drew Trevor
Published: July 2007

The posterior parietal cortex (PPC) is an important source of input to the motor cortex in both the primate and the cat. However, the available evidence from the cat suggests that the projection from the PPC to those rostral areas of the motor cortex that project to the intermediate and ventral parts of the spinal gray matter is relatively small. This leaves in question the importance of the contribution of the PPC to the initiation and modulation of voluntary movements in the cat. As this anatomical evidence is not entirely compatible with the physiological data, we reinvestigated the PPC projection to the motor cortex by injecting dextran amine tracers either into the proximal or distal representations of the forelimb in the rostral motor cortex, into the representation of the forelimb in the caudal motor cortex, or into the hindlimb representation. The results show strong projections from the PPC to each of these regions. However, projections to the rostral motor cortex were observed primarily from the caudal bank of the ansate sulcus and the adjacent gyrus, whereas those to the caudal motor cortex were generally located more rostrally. There was also evidence of some topographic organization with the distal limb being located progressively more laterally and rostrally in the PPC than the areas projecting to more proximal regions. In contrast to previous anatomical investigations, these results suggest that the PPC can potentially modulate motor activity via its strong projection to the more rostral regions of the motor cortex. J. Comp. Neurol. 504:17–41, 2007. © 2007 Wiley‐Liss, Inc.
Androgen receptors in a cichlid fish, Astatotilapia burtoni: Structure, localization, and expression levels
Authors: Harbott Lene K. , Burmeister Sabrina S. , White Richard B. , Vagell Mike , Fernald Russell D.
Published: July 2007

Androgens are an important output of the hypothalamic‐pituitary‐gonadal (HPG) axis that controls reproduction in all vertebrates. In male teleosts two androgens, testosterone and 11‐ketotestosterone, control sexual differentiation and development in juveniles and reproductive behavior in adults. Androgenic signals provide feedback at many levels of the HPG axis, including the hypothalamic neurons that synthesize and release gonadotropin‐releasing hormone 1 (GnRH1), but the precise cellular site of androgen action in the brain is not known. Here we describe two androgen receptor subtypes, ARα and ARβ, in the cichlid Astatotilapia burtoni and show that these subtypes are differentially located throughout the adult brain in nuclei known to function in the control of reproduction. ARα was expressed in the ventral part of the ventral telencephalon, the preoptic area (POA) of the hypothalamus and the ventral hypothalamus, whereas ARβ was more widely expressed in the dorsal and ventral telencephalon, the POA, and the ventral and dorsal hypothalamus. We provide the first evidence in any vertebrate that the GnRH1‐releasing neurons, which serve as the central control point of the HPG axis, express both subtypes of AR. Using quantitative real‐time PCR, we show that A. burtoni AR subtypes have different expression levels in adult tissue, with ARα showing significantly higher expression than ARβ in the pituitary, and ARβ expressed at a higher level than ARα in the anterior and middle brain. These data provide important insight into the role of androgens in regulating the vertebrate reproductive axis. J. Comp. Neurol. 504:57–73, 2007. © 2007 Wiley‐Liss, Inc.
Measurement of streamer charge distribution on an insulator in SF6 Gas
Authors: Yamamoto Osamu , Hara Takehisa , Hayashi Muneaki
Published: July 2007

The charge density produced by streamers on an insulator surface in SF6 has been investigated by using a probe method with a high‐speed temporal resolution. Concentric circular probes, which also act as a plane electrode, are used in this probe method. Probe signals are observed oscilloscopically and converted into the charge densities through a numerical calculation. This method reveals the charge distribution before a disturbance caused by the “back discharge.” The charge density thus obtained ranges from several nC/cm2 up to about 60 nC/cm2. The density depends on the pressure, voltage height and the position of the streamer.

The electric field on the insulator is analyzed numerically taking into account the surface charge. The internal electric field of the streamer is found to be 40 ∼ 50 kV/cm · atm when the streamer ceases its propagation. However, it partly exceeds the critical one (89 kV/cm · atm) during the propagation.
Fuzzy user interface: Its application to power system operation
Authors: Ogi Hiromi , Takeshima Yuriko , Shinohara Jyunichi , Mouri Masahiro , Ishikawa Fujie
Published: July 2007

A power system is configured from generating plants, substations, consumers and the transmission lines that tie them together. To perform inspection, maintenance and expansion of these facilities, regular and systematic outage of this system must be conducted.

Moreover, the organization that manages this power system is a hierarchy that comprises various levels. To prepare a comprehensive schedule from the various outage requests submitted by the many sections, it is necessary for the engineer to investigate thousands of outage requests based on reliability of the power system, economical supply of power, and personnel safety.

This paper presents a computerized support system that has been developed to support a coordinating engineer in power system outage scheduling. The user interface expressed as fuzzy expressions “Fuzzy User Interface” that comprises an operator model of the coordinating engineer based on analysis of such work performed at a dispatching center is discussed.
Control of SF6 discharge gap switch by XeCl excimer laser
Authors: Okuda Hisato , Katayama Kazuhisa , Wang Xiaojun , Masugata Katsumi , Yatsui Kiyoshi
Published: July 2007

Experimental studies have been carried out on triggering characteristics of the SF6 discharge gap switch by use of XeCl excimer laser (wavelength = 308 nm).

First, laser irradiation characteristics are studied on a pure SF6 in the pressure range of p = 160 ∼ 3,800 torr. Using a lens of f (focal length) = 133 mm, the laser is irradiated into the gas, where the energy absorption is studied. If the laser is injected into the gas with the energy above a certain threshold for the breakdown, the rate of energy absorption is found to be ∼ 17 percent of the incident energy at p > 760 torr.

Injecting the laser into the SF6‐filled gap switch (gap length = 7 mm, p = 760 torr), we have studied the triggering characteristics. Excellent triggering characteristics were obtained; delay time for the discharge ∼ 20 ns, and the jitter ∼ 260 ps when the gap voltage is operated at 99 percent of the self‐breakdown voltage. In addition, the triggering characteristics are studied by changing the focusing point axially. It is found that both the delay time and the jitter decrease when the focusing point tends to approach the high‐voltage electrodes.
A new method for power generation planning and problems of uncertainty
Authors: Fujii Yasumasa , Kaya Yoichi
Published: July 2007

This paper presents a new method for power system planning which considers uncertainties of various system parameters as a part of the criterion function. The criterion function involves both the expected values of total system costs and the cost variances of different power plants.

Previously, the authors proposed that these cost variances be evaluated from the existing power system plans in the form of the solutions to the inverse optimization problem, and then applied this procedure to the planning of power systems in Japan. However, because of the correlation between fuel and facility costs, the cost variances could not be determined as specific values.

Here, to overcome this difficulty, the authors now introduce hydropower plants into the model as the so‐called nonrisky elements and focus on the expenditure shares rather than the plant capacity shares. As a result, more reasonable results are obtained.

This improved methodology is applied and the derived cost variances are shown. Further, using the resultant cost variances, the authors make Pareto‐optimal power generation plans and demonstrate also the robustness of the method to price fluctuations.
Verification of the fracture mechanism of β″‐aluminas caused by large current density
Authors: Ohshima Masaaki , Kobayashi Akira , Yoshida Akihiko , Tsuji Hiromochi
Published: July 2007

β″‐aluminas which transmit sodium ions and do not conduct electrons are expected to be applied in practice for solid electrolytes and separators in sodium‐sulfur batteries. It is known that a large sodium ion current density fractures β″‐aluminas instantly.

To clarify this fracture mechanism, the temperature and thermal stress distributions in a β″‐alumina tube generated by transmitting sodium ions were calculated. Then using β″‐alumina tubes, experiments were carried out in which β″‐alumina were cracked by a large current density. The values of thermal stress in these experiments wre solved using upper calculation. These values were almost equal to those of the mechanical strength of β″‐aluminas. The fracture mechanism of β″‐aluminas by transmission of a large sodium ion current density is thermal stress generated by Joule loss in β″‐aluminas.
Coal‐gas‐burning high‐efficiency power plant which recovers generated carbon dioxide
Authors: Pak Pyong Sik , Nakamura Ken'Ichi , Suzuki Yutaka
Published: July 2007

This paper describes the characteristics and construction of a coal‐gas‐burned high efficiency power plant which emits no carbon dioxide (CO2) into the atmosphere. In a plant, CO2 gas and superheated steam are used as the main and the secondary working fluids, respectively, of a closed dual fluid regenerative gas turbine power plant. Since coal gas composed of CO, H2, CO2 and CH4 is burned in a combustor using oxygen, the exhaust gas let into a condenser includes only CO2 and H2O. Hence, CO2 gas can be easily separated at the condenser outlet from condensate. In the plant, the combustion gas is first used to generate power by driving a turbine. High‐temperature turbine exhaust gas is next utilized at a regenerator to heat the main working fluid of CO2 gas flowing into the combustor, and then is utilized at a waste heat boiler to produce the superheated steam injected into the combustor. It is estimated that the power can be generated with gross thermal efficiency of 54.4 percent, and that the power generating efficiency is 46.7 percent. Generating efficiency is calculated by subtracting the power required for producing the high‐pressure oxygen used for combustion from the generator output. It is shown that the estimated efficiency is higher by 18.1 percent than that of a conventional boiler steam turbine power generating plant into which a process for removing and recovering CO2 from the stack gas by utilizing alkanolamine‐based solvent is integrated.
Effect of plasma surface modification on electrical conduction in polyethylene
Authors: Hayashi Hisaaki , Nakano Toshiki , Ohki Yoshimichi
Published: July 2007

High‐density polyethylene films 50 μm thick were exposed to the downstream plasma flow of RF glow discharges in argon, hydrogen, or oxygen. It was found that many transvinylene and unreacted radicals remain after the argon or hydrogen plasma treatment, and that carbonyl groups are formed in the oxygen plasma treatment.

The conduction current was smaller in the hydrogen‐plasma treated samples and the samples exposed to oxygen or ozone after hydrogen‐plasma treatment than in the untreated samples. Thermal pulse current measurements indicate that the treated surface layer traps electrons or holes and reduces the field strength at the electrode surface, thus suppressing further injection of electrons or holes.
Increase of breakdown voltage due to composite insulation in SF6 gas
Authors: Yoshida Tetsuo , Miyagawa Masaru , Ohshima Iwao , Masaki Nobuo , Yanabu Satoru
Published: July 2007

The breakdown characteristics using a hemispherical tip rod (10 ∼ 60 mm) molded with epoxy resin‐to‐plate gap in SF6 gas up to 0.20 MPa was studied.

The result shows that breakdown characteristics are classified into three regions (A, B and C region) depending on gap length. In the A‐region breakdown voltage is lowered compared with bare hemispherical tip rod‐to‐plate gap. In the B‐region breakdown voltage is raised sharply with gap length and in the C‐region it saturates. The maximum increase ratio of breakdown voltage in the B and C region are 1.95 times (ac) and 1.68 times (impulse) compared with a bare hemispherical tip rod‐to‐plate gap characteristic.

The ratios depend on the diameter of the spherical tip rod and the thickness of epoxy resin. It is concluded that the increase of breakdown voltage is attributed to the synergism effect of the decrease of maximum electric field strength by epoxy resin and the suppression of field emission.

The use of composite insulation reduces the gap length drastically in the gas‐insulated switchgear, for instance, C‐GIS (Cubicle‐type Gas‐Insulated Switchgear).
Load frequency control using power demand estimation and fuzzy control
Authors: Avatchanakorn Vichit , Ueda Akihiko , Gotoh Yasuyuki , Mizutani Yoshibumi
Published: July 2007

Numerous control methods based on modern control theory have been proposed to improve the load frequency control (LFC) characteristics of power systems. These control methods generally regard the load frequency control system as a linear system model. Furthermore, complicated mathematical equations have to be solved to determine control laws. However, realistic power systems are nonlinear, i.e., the nonlinearities of tie‐lines connecting between the control areas and of generation rate constraints of power plants exist. Consequently, it is considered that the design of controllers is difficult.

In this paper, the application of fuzzy control to the load frequency control system is proposed to solve the forementioned problems. The proposed control first, to satisfy the load frequency control requirements, estimates power demand variations of the control areas and uses them as the output set‐point values of power plants, instead of using an integral‐type controller. Next, to improve stability and optimality of the nonlinear load frequency control system using the fore‐mentioned output set‐point control method, the proportional‐type fuzzy control considering a computation time‐delay is implemented. Parameters of the proposed fuzzy controller are determined by minimizing the integral square of the area control error (ACE) to ensure optimality of the system.
Analysis of lightning surge overvoltages at substation using steady‐state solution
Authors: Ametani Akihiro , Ohnishi Hironori
Published: July 2007

The present paper proposes a method for analyzing lightning surge overvoltages at a substation by means of steady‐state solutions. The lightning current is assumed to be periodic and representable by a Fourier series. The frequency responses of the line and substation impedances as seen from the substation entrance and the response of the steady‐state solution for the open‐end line voltage with the substation removed are then easily obtained. The steady‐state voltage at the substation entrance is evaluated from the above frequency responses by means of The‐venin's theorem. The transient voltage is expressed as the sum of Fourier series of the steady‐state voltages. The lightning surge overvoltages calculated by the proposed method are in satisfactory agreement with the transient solutions calculated by the EMTP technique, and the computation time and memory requirements are far smaller.

Because the proposed method evaluates the lightning surge overvoltage only in terms of steady‐state solutions, it is conveniently used to evaluate the effect of the circuit parameters of a substation in terms of ac theory and thus may be useful in investigating the relationship between bus length and overvoltage, in estimating the optimum location of an arrester installation, and so on.
High‐electric field conduction phenomena in poly‐2‐chloro‐p‐xylylene/poly‐p‐xylylene composite thin films
Authors: Mori Tatsuo , Mizutani Teruyoshi
Published: July 2007

The high‐field currents in poly‐p‐chloro‐xylylene (PCPX) thin films are due to hole injection from anode metal and collision ionization. PPX thin films showed the negative temperature dependence of high‐field currents. Since the chlorine atoms in PCPX thin films act as carrier scattering centers, high‐field currents in PCPX thin films are suppressed in the low‐temperature region.

This paper discusses the high‐field currents of PCPX/PPX composite thin films; these films are PCPX thin films (d < 150 nm) deposited on PPX thin films (d > 200 nm). They were strongly suppressed at room temperature, but not at low temperature. Therefore, PCPX/PPX composite thin films showed a remarkable negative temperature dependence of high‐field currents. High‐field currents were suppressed more in PCPX (60 nm)/PPX (230 nm) composite thin film than in PCPX (130 nm)/PPX (230 nm). This can be explained by the suppression of the hole injection from anode by homo space charge at the interface between PCPX/PPX.
Decentralized load frequency control on each power plant
Authors: Tanaka Eiichi , Hasegawa Jun
Published: July 2007

This paper presents a load frequency control system using a refined controller for interconnected power systems. The controller consists of an integral compensator and state feedback. It has been proven that any transfer function between a reference input and a controlled output or between a disturbance and a controlled output is attained by this controller if it is attainable by realizable linear compensation. Parameters of the controller are determined by the optimal regulator theory and additional calculation.

The controller can reduce time deviation and inadvertent interchange without information about tie‐lines as well as deviations of frequency and net interchange power. This structural features makes it possible to design the control system for each regulating power plant instead of for the control center. If some state variables are not available, the control system can be designed with the remainder of state variables and a dynamic compensator.

Simulation results show that the control system is superior to the TBC system.
Relation between the superstructures and the tree deterioration in polypropylene
Authors: Yamakita Takayuki , Ariyasu Tomio
Published: July 2007

The initiation and growth of the electrical tree in crystalline polymers are influenced by the superstructure. However, there are still many unclear points in the relationship between the tree deterioration and the superstructure (spherulites).

To study the relationship between the tree deterioration and the spherulite, we designed the measuring apparatus which allows simultaneous observation of these phenomena. The sample was set on the stage of the polarizing microscope to make observations of the tree initiation and growth in polypropylene.

This paper reports the results of some observations concerning the tree initiation and growth in polypropylene with 60‐Hz ac voltage. The results are as follows:

Prior to the initiation of trees, a fine deterioration zone is formed on spherulite surfaces. Thereafter, the discharge occurs along the spherulite surface, and the trees occur.

Tree shapes change under the influence of the distribution state of spherulite.

Tree initiation voltage is 5.8 kV for the spherulite inside and 5.1 kV for the spherulite boundary, respectively.
New balance ground relay for parallel four‐circuit transmission lines
Authors: Kai Takaaki , Nomura Shizuo , Ando Takeshi
Published: July 2007

A 66‐kV network generally is grounded through a neutral grounding resistor. In this network a single‐phase ground‐fault current is limited to as small as 100 to 400 A. There are parallel four‐circuit transmission lines mounted on the same tower in the 66‐kV network. In such transmission lines, the load and the fault currents could induce circulating current that flows through the lines. Since the circulating current has zero‐phase‐sequence and negative‐phase‐sequence components, it could cause unwanted operation of a balance ground relay using zero‐phase‐sequence current. However, it is difficult to compensate for the circulating current by the conventional vector compensation scheme.

This paper presents a new balance ground relay to deal with the circulating current. In the relay from the ground‐fault inception until first tripping, the difference current Δ3I2d of negative‐phase‐sequence current 3I2d of the differential current between two protected lines is used as an input current. The Δ3I2d is the difference current of 3I2d between, before and during faults. After the first tripping, the difference current of positive‐phase‐sequence load current and zero‐phase‐sequence current of the forementioned differential current are used as an input current. Consequently, a higher sensitivity of the ground‐fault protection for these lines has been achieved. The correct operation of the new balance ground relay was confirmed when a single‐phase‐ground‐fault occurred in the parallel four‐circuit transmission lines, to which the relay is applied.
Development of an on‐line stabilization method for local power systems with large‐capacity generation plants
Authors: Suzuki Mamoru , Yanagihashi Ken , Tomizawa Kazuhiro , Gouda Tadahiro , Oshida Hideharu
Published: July 2007

This paper presents an on‐line stabilization control method developed with the aim of maintaining transient stability in a local power system which includes large‐capacity generation plants. The characteristics of this method are that the power/angle curve is estimated from the on line active and reactive power measured at the generator terminal, and the optimum generation shedding for stabilization is determined by applying the equal area method to this curve.

Simulation tests using detailed models of the power system confirmed that the optimum generation shedding for stabilization could be computed for various fault conditions, both symmetrical or asymmetrical.

It was also determined that the on‐line data could be sampled for several tens of milliseconds after clearing the fault. Thus, this method provides effective control logic for practical stabilizing systems.
Accuracy of waveform parameters in digital measurement of single‐shot waveforms
Authors: Michishita Koji , Kawamura Tatsuo , Ishii Masaru
Published: July 2007

In high‐voltage measurement, the digital measuring system is used widely because of its attractive features, for example, automatic data acquisition. However, the accuracy in the measurement of both the amplitude and time parameters by the digital measuring system is not known in detail, especially in the measurement of single‐shot waveforms.

In this paper, the accuracy of the peak value and the virtual front time of the standard lightning impulse without any signal processing of raw data is shown. From these results, the required characteristics for the digital measuring system to satisfy the IEC Draft on digital recorders for measurement in high‐voltage impulse test techniques are shown. In addition, the accuracy of the peak voltage and the rise time of the Gaussian pulse is shown.