bluuebunny/crossref_metadata_2025 huggingface dataset:
Thaliporphine protects ischemic and ischemic‐reperfused rat hearts via an NO‐dependent mechanism
Authors: Hung Li‐Man , Lee Shoei‐Sheng , Chen Jan‐Kan , Huang Shiang‐Suo , Su Ming‐Jai
Published: August 2002

In ischemia or ischemia‐reperfusion (I/R), nitric oxide (NO) can potentially exert several beneficial effects. Thaliporphine, a natural alkaloid with Ca2+ channel‐activating and Na+/K+ channel‐blocking activities, increased NO levels and exerted cardioprotective action in ischemic or I/R rats. The role of NO in the cardioprotective actions of thaliporphine was assessed. The severity of rhythm disturbances and mortality in anesthetized rats with either coronary artery occlusion for 30 min, or 5 min followed by 30‐min reperfusion, were monitored and compared in thaliporphine‐ vs. placebo‐treated groups. Thaliporphine treatment significantly increased NO and decreased lactate dehydrogenase (LDH) levels in the blood during the end period of ischemia or I/R. These changes in NO and LDH levels by thaliporphine were associated with a reduction in the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF) during ischemic or I/R period. The mortality of animals was also completely prevented by 1 × 10–8 moles/kg of thaliporphine. In animals subjected to 4 h of left coronary artery occlusion, 1 × 10–7 moles/kg of thaliporphine dramatic reduced cardiac infarct zone from 46 ± 6% to 7.1 ± 1.9%. Inhibition of NO synthesis with 3.7 × 10–6 moles/kg of Nω ‐nitro‐L‐arginine methyl ester (L‐NAME) abolished the beneficial effects of thaliporphine during 30 min or 4 h myocardial ischemia. However, the antiarrhythmic activity and mortality reduction efficacy of thaliporphine during reperfusion after 5 min of ischemia was only partially antagonized by L‐NAME. These results showed that thaliporphine efficiently exerted the cardioprotections either in acute or prolonged coronary artery occlusion or occlusion‐reperfusion situations. The fact that thaliporphine induced cardioprotective effects were abrogated by L‐NAME indicates that NO is an important mediator for the cardioprotective effects of thaliporphine in acute or prolonged ischemia, whereas antioxidant activities may contribute to the protection of I/R injury. Drug Dev. Res. 52:446–453, 2001. © 2001 Wiley‐Liss, Inc.
Lipophilic methotrexate conjugates with glucose‐lipoamino acid moieties: Synthesis and in vitro antitumor activity
Authors: Pignatello Rosario , Vicari Luisa , Sorrenti Valeria , Di Giacomo Claudia , Spampinato Giuseppina , Puglisi Giovanni , Toth Istvan
Published: August 2002

To obtain methotrexate (MTX) derivatives with a balanced hydrolipophilic character, we synthesized a series of conjugates in which the drug was linked to lipoamino acid (LAA)‐glucose residues (LAAG‐MTX). These conjugates displayed increased solubility in polar media compared with the corresponding LAA‐MTX conjugates previously described. In vitro biological testing of LAAG‐MTX indicated that the introduction of the sugar moiety decreased the biological activity of these MTX conjugates. The tetradecyl derivative 6b, however, was effective in inhibiting the dihydrofolate reductase activity in vitro and showed an inhibitory effect on human lymphoblastoid cell growth. Drug Dev. Res. 52:454–461, 2001. © 2001 Wiley‐Liss, Inc.
Cardiac effects of diinosine tetraphosphate, a putative dinucleotide receptor antagonist
Authors: Stavrou Brigitte M. , Abdel‐Rahman Saif‐El‐Dean Tawfik , Pintor Jesús , Gualix Javier , Miras‐Portugal M. Teresa , Sheridan Desmond J. , Flores Nicholas A.
Published: August 2002

The cardiac electrophysiological and vasomotor effects of diinosine tetraphosphate (Ip4I, 10 nM and 1 μM) were examined in guinea pig isolated hearts together with its ability to antagonize the effects of diadenosine tetraphosphate (Ap4A, 1 nM and 1 μM). Ip4I had no effects on action potential duration or refractory period and attenuated the electrophysiological effects of Ap4A at both concentrations. Although Ip4I increased coronary perfusion pressure, the vasomotor effects of Ap4A were resistant to antagonism by Ip4I. These observations support data from neural tissues and indicate that diinosine polyphosphates may antagonize cardiac electrophysiological effects of diadenosine polyphosphates. Drug Dev. Res. 52:500–503, 2001. © 2001 Wiley‐Liss, Inc.
Characterisation of the P2X7 receptor‐mediated signalling pathway associated with rapid killing of intracellular mycobacteria within human macrophages
Authors: Stober Carmel B. , Ben‐Smith Anne , Kumararatne Dinikantha , Lammas David A.
Published: August 2002

Investigation of the P2X7 receptor‐associated signalling events following ATP stimulation of Mycobacterium bovis BCG‐infected human macrophages revealed that ATP‐mediated cell death and associated mycobacterial killing could be functionally uncoupled. Inhibitors of phospholipase D (PLD) (wortmannin and butan‐1‐ol), phospholipase A2 (PLA2) (GW 624A and GW 625A) and the mitogen‐activated protein kinase (MAPK) pathway (SB203580 and PD98059) all antagonised the ATP‐mediated killing of intracellular mycobacteria, but had no effect on ATP‐induced macrophage death. Inhibitors of protein kinase C (PKC), protein tyrosine kinases (PTKs), and protein serine/threonine phosphatases (PSTPs) were ineffective against either ATP‐stimulated cell death or bacterial killing. The mycobactericidal effects of ATP were not associated with the induction of apoptosis per se as the broad spectrum caspase inhibitor, ZVAD‐fmk, failed to block killing of mycobacteria within human macrophages. Inhibitors of protein synthesis (cycloheximide) and transcription (actinomycin D) were also ineffective against the cytotoxic and bactericidal responses of ATP, suggesting that the terminal effector mediator(s) involved is preformed and does not require de novo synthesis. Immunoelectron microscopy studies using intracellular probes to identify lysosomes revealed that ATP treatment of BCG‐infected macrophages induced the progressive colocalisation of mycobacteria‐containing phagosomes with lysosomes. The data suggests that ATP‐induced killing of intracellular mycobacteria involves the cellular activation of PLD, PLA2, and MAP kinase, and these signalling events lead to the maturation of the BCG‐containing phagosome culminating in the demise of the invading mycobacteria. Drug Dev. Res. 53:105–116, 2001. © 2001 Wiley‐Liss, Inc.
P2 nucleotide receptors in osteoclasts
Authors: Naemsch Lin N. , Du Xiaobing , Sims Stephen M. , Dixon S. Jeffrey
Published: August 2002

Osteoclasts are large, multinucleated cells responsible for the resorption of bone and other mineralized tissues. Whereas low concentrations of extracellular ATP stimulate osteoclast formation and resorptive activity, high concentrations inhibit osteoclast formation. Cell surface receptors for nucleotides are classified into two families—P2X (ligand‐gated channels nonselective for cations) and P2Y (G‐protein‐coupled receptors linked, in most cases, to release of Ca2+ from intracellular stores). Several subtypes of P2 receptors are expressed by mammalian osteoclasts. The P2X4 receptor has been identified at both protein and messenger RNA levels and ATP activates a nonselective cation current with properties similar to that mediated by the cloned P2X4 channel. The P2X2 receptor is also expressed; however, currents with properties of P2X2 have yet to be identified. Functional and expression studies also support the existence of the P2X7 receptor, which is activated by high concentrations of ATP. Application of nucleotides to osteoclasts elicits transient elevation of cytosolic free Ca2+ concentration and activation of Ca2+‐dependent K+ channels. Both these responses are mediated, at least in part, by release of Ca2+ from intracellular stores, consistent with the presence of functional P2Y receptors. Expression of P2Y1 and P2Y2 receptors has been demonstrated in mammalian osteoclasts. The presence of multiple subtypes of P2 receptors may account for the biphasic effects of extracellular nucleotides on osteoclast function. These receptors represent potential targets for the development of novel therapeutics to inhibit bone resorption in diseases such as rheumatoid arthritis, osteoporosis, tumor‐induced osteolysis, and periodontitis. Drug Dev. Res. 53:130–139, 2001. © 2001 Wiley‐Liss, Inc.
Independent signaling pathways in ATP‐evoked secretion of plasminogen and cytokines from microglia
Authors: Inoue Kazuhide
Published: August 2002

We investigated the action of ATP on the secretion of plasminogen, TNF‐α, and IL‐6 from microglia. ATP (10–100 μM) stimulated the release of plasminogen from rat cultured microglia in a concentration‐dependent manner with a peak response at 5–10 min after the stimulation. The release was dependent on extracellular Ca2+ and was blocked by pretreatment with oxidized ATP, a blocker of P2X7. UTP, an agonist of P2Y2, also stimulated the release of plasminogen from a subpopulation (about 20% of total cells) of cultured microglia. The release was also dependent on extracellular Ca2+, suggesting a role of stocker‐operated calcium entry (SOC). ATP potently stimulated TNF‐α release from 2 h after the stimulation with TNF‐α mRNA expression in primary cultures of rat brain microglia. The TNF‐α release was maximally elicited by 1 mM ATP and 2′‐ and 3′‐O‐(4‐benzoylbenzoyl)‐adenosine 5′‐triphosphate (BzATP), a P2X7 selective agonist, suggesting the involvement of P2X7. This TNF‐α release was correlated with a sustained Ca2+ influx. The release was inhibited by PD98059, an inhibitor of MEK1 which activates extracellular signal‐regulated protein kinase (ERK), and SB203580, an inhibitor of p38 MAP kinase. However, both ERK and p38 were rapidly activated by ATP even in the absence of extracellular Ca2+. These results indicate that extracellular ATP triggers TNF‐α release in rat microglia via P2X7 in a manner dependent on the sustained Ca2+ influx and via the ERK/p38 cascade independently of Ca2+ influx. ATP caused the mRNA expression and release of IL‐6 in a concentration‐dependent manner in MG‐5. The physiological meaning of these independent release mechanisms is also discussed. Drug Dev. Res. 53:166–171, 2001. © 2001 Wiley‐Liss, Inc.
Antinociceptive profile of the natural cholinesterase inhibitor huperzine A
Authors: Galeotti Nicoletta , Ghelardini Carla , Di Cesare Mannelli Lorenzo , Bartolini Alessandro
Published: August 2002

The antinociceptive effect of huperzine A, a novel cholinesterase inhibitor, was investigated in the mouse hot‐plate and abdominal constriction tests. Huperzine A induced a dose‐dependent antinociception (70–110 μg kg–1 i.p.) which was prevented by scopolamine (0.1 mg kg–1 i.p.) and S‐(–)‐ET 126 (0.01 μg per mouse i.c.v.), but not by naloxone (1 mg kg–1 i.p.), mecamylamine (2 mg kg–1 i.p.), α‐methyl‐p‐tyrosine (100 mg kg–1 i.p.), or CGP 35348 (100 mg kg–1 i.p.). A dose‐dependent inhibition of the antinociception induced by huperzine A (110 μg kg–1 i.p.) was observed after inactivation of the M1 gene by an antisense oligodeoxyribonucleotide (aODN). This effect was detected 24 h after the last intracerebroventricular injection of aODN. Time‐course experiments revealed that, after the end of the aODN treatment, sensitivity to analgesic drugs progressively appeared, reaching the normal range at 96 h. Huperzine A, at the maximal effective doses, did not produce any alteration of mice motor coordination, as revealed by rota‐rod experiments. These results indicate that huperzine A is endowed by muscarinic antinociceptive properties mediated by the activation of central M1 muscarinic receptor subtype. Drug Dev. Res. 54:19–26, 2001. © 2001 Wiley‐Liss, Inc.
Clinical application of NKT cell assays to the prediction of type 1 diabetes
Authors: Poulton Lynn D. , Baxter Alan G.
Published: August 2002

Type 1 diabetes is a disease characterised by disturbed glucose homeostasis, which results from autoimmune destruction of the insulin‐producing beta cells in the pancreas. The autoimmune attack, while not yet fully characterised, exhibits components of both mis‐targeting and failed tolerance induction. The involvement of non‐classical lymphocytes in the induction and maintenance of peripheral tolerance has recently been recognised and natural killer T (NKT) cells appear to play such a role. NKT cells are a subset of T cells that are distinct in being able to produce cytokines such as IL‐4 and IFN‐γ extremely rapidly following activation. These lymphocytes also express some surface receptors, and the lytic activity, characteristic of NK cells. Deficiencies in NKT cells have been identified in animal models of type 1 diabetes, and a causal association has been demonstrated by adoptive transfer experiments in diabetes‐prone NOD mice. Preliminary work suggests that a similar relationship may exist between deficiencies in NKT cells and type 1 diabetes in humans, although the techniques reported to date would be difficult to translate to clinical use. Here, we describe methods appropriate to the clinical assessment of NKT cells and discuss the steps required in the assessment and validation of NKT cell assays as a predictor of type 1 diabetes. Copyright © 2001 John Wiley & Sons, Ltd.
Docking protein SNT1 is a critical mediator of fibroblast growth factor signaling during Xenopus embryonic development
Authors: Akagi Keiko , Kyun Park Eui , Mood Kathleen , Daar Ira O.
Published: August 2002

The docking protein SNT1/FRS2 (fibroblast growth factor receptor substrate 2) is implicated in the transmission of extracellular signals from several growth factor receptors to the mitogen‐activated protein (MAP) kinase signaling cascade, but its biological function during development is not well characterized. Here, we show that the Xenopus homolog of mammalian SNT1/FRS‐2 (XSNT1) plays a critical role in the appropriate formation of mesoderm‐derived tissue during embryogenesis. XSNT1 has an expression pattern that is quite similar to the fibroblast growth factor receptor‐1 (FGFR1) during Xenopus development. Ectopic expression of XSNT1 markedly enhanced the embryonic defects induced by an activated FGF receptor, and increased the MAP kinase activity as well as the expression of a mesodermal marker in response to FGF receptor signaling. A loss‐of‐function study using antisense XSNT1 morpholino oligonucleotides (XSNT‐AS) shows severe malformation of trunk and posterior structures. Moreover, XSNT‐AS disrupts muscle and notochord formation, and inhibits FGFR‐induced MAP kinase activation. In ectodermal explants, XSNT‐AS blocks FGFR‐mediated induction of mesoderm and the accompanying elongation movements. Our results indicate that XSNT1 is a critical mediator of FGF signaling and is required for early Xenopus development. © 2002 Wiley‐Liss, Inc.
Induction of chondrogenesis in neural crest cells by mutant fibroblast growth factor receptors
Authors: Petiot Anita , Ferretti Patrizia , Copp Andrew J. , Chan Chi‐Tsung Joseph
Published: August 2002

Activating mutations in human fibroblast growth factor receptors (FGFR) result in a range of skeletal disorders, including craniosynostosis. Because the cranial bones are largely neural crest derived, the possibility arises that increased FGF signalling may predispose to premature/excessive skeletogenic differentiation in neural crest cells. To test this hypothesis, we expressed wild‐type and mutant FGFRs in quail embryonic neural crest cells. Chondrogenesis was consistently induced when mutant FGFR1‐K656E or FGFR2‐C278F were electroporated in ovo into stage 8 quail premigratory neural crest, followed by in vitro culture without FGF2. Neural crest cells electroporated with wild‐type FGFR1 or FGFR2 cDNAs exhibited no chondrogenic differentiation in culture. Cartilage differentiation was accompanied by expression of Sox9, Col2a1, and osteopontin. This closely resembled the response of nonelectroporated neural crest cells to FGF2 in vitro: 10 ng/ml induces chondrogenesis, Sox9, Col2a1, and osteopontin expression, whereas 1 ng/ml FGF2 enhances cell survival and Sox9 and Col2a1 expression, but never induces chondrogenesis or osteopontin expression. Transfection of neural crest cells with mutant FGFRs in vitro, after their emergence from the neural tube, in contrast, produced chondrogenesis at a very low frequency. Hence, mutant FGFRs can induce cartilage differentiation when electroporated into premigratory neural crest cells but this effect is drastically reduced if transfection is carried out after the onset of neural crest migration. © 2002 Wiley‐Liss, Inc.
Perturbation of extracellular matrix prevents association of the otic primordium with the posterior rhombencephalon and inhibits subsequent invagination
Authors: Visconti Richard P. , Hilfer S. Robert
Published: August 2002

In the avian embryo, the otic primordia become visible by Hamburger and Hamilton stage 10 as a pair of thickened regions of head ectoderm. In contrast to other epithelial primordia, invagination occurs by means of formation of a series of folds in distinct areas of the primordium, giving the otic vesicle a box‐like appearance. Because previous work has shown that otic invagination is ATP and calcium independent, it is unlikely that cytoskeletal changes are the primary mechanism responsible for invagination as in other epithelial primordia. Interaction of the primordium with surrounding tissues may provide the force for otic invagination. These extracellular forces may be transduced through extracellular matrix macromolecules and their cell surface receptors. This investigation tests the hypothesis that fusion of the otic and hindbrain basal laminae between stages 11 and 13 is necessary for normal invagination. Perturbation of binding of the otic primordium to the neural tube was accomplished by means of microinjection of antibodies to various extracellular matrix components and integrin subunits into the head mesenchyme in the otic region at stage 10. Only antibodies to laminin and integrins caused detachment of the otic primordium from the hindbrain. These experiments suggest that fusion of the otic and hindbrain basal laminae is required for subsequent invagination and, furthermore, that this event is mediated by components of the extracellular matrix. © 2001 Wiley‐Liss, Inc.
Cross‐linguistic transfer of phonological skills: a Malaysian perspective
Authors: Gomez Caroline , Reason Rea
Published: August 2002

This study examined the phonological and reading performance in English of Malaysian children whose home language was Bahasa Malaysia (BM). A sample of 69 Malaysian Standard Two pupils (aged 7–8 years) was selected for the study. Since commencing school at the age of 6 years, the children had been learning to read in BM and had subsequently also been learning to read in English for some 12 months. The study was part of a larger scale research programme that fully recognized the limitations of tests that had not been developed and standardized in Malaysia. Nevertheless, as a first step to developing such tests, a comparison with existing norms for the Phonological Assessment Battery (PhAB) and the Wechsler Objective Reading Dimension (WORD) was undertaken in relation to information about the children's L1 and L2 language competencies. Results showed that the children's performance on PhAB was at least comparable to the UK norms while, not surprisingly, they fared less well on WORD. The results are discussed in terms of L1 and L2 transfer, whereby the transparency of written BM and the structured way in which reading is taught in BM facilitates performance on phonological tasks in English. This has implications for identifying children with phonologically based reading difficulties. Copyright © 2002 John Wiley & Sons, Ltd.
Alcohol abuse and dysfunctional eating in adolescent girls: The influence of individual differences in sensitivity to reward and punishment
Authors: Loxton Natalie J. , Dawe Sharon
Published: August 2002

Objective

An unusually high comorbidity of eating disorders and alcohol abuse has been found in clinical and community samples of young women. This paper proposes that individual differences in sensitivity to reward and punishment may influence the propensity of young women to engage in dysfunctional eating and drinking behaviour.

Method

The Drive for Thinness scale, the Alcohol Use Disorders Identification Test and the BIS/BAS scales were administered to 232 high school girls.

Results

Heightened sensitivity to reward was the better predictor of alcohol misuse while heightened sensitivity to both reward and punishment was predictive of dysfunctional eating. When categorised by group, alcohol abusing, dysfunctional eating, and comorbid girls reported greater sensitivity to reward than non‐disordered girls. Girls with dysfunctional eating with and without comorbid alcohol abuse reported greater sensitivity to punishment than alcohol abusing only girls.

Discussion

These findings suggest that girls who abuse alcohol and have dysfunctional eating may share a vulnerability to heightened sensitivity to reward, yet be differentiated by sensitivity to punishment. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 455–462, 2001.
Core beliefs and bulimic symptomatology in non‐eating‐disordered women: The mediating role of borderline characteristics
Authors: Meyer Caroline , Leung Newman , Feary Rachel , Mann Baljit
Published: August 2002

Objective

To establish whether borderline personality disorder symptoms play a mediating role in the relationship between early maladaptive schemata and bulimic symptomatology, using a nonclinical sample.

Method

Sixty‐one female undergraduate students completed the Bulimic Investigatory Test, Edinburgh (BITE), the Borderline Syndrome Index (BSI), and the short form of the Young Schema Questionnaire (YSQ).

Results

Borderline symptoms were found to be a perfect mediator in the relationship between defectiveness/shame beliefs and bulimic symptomatology.

Conclusions

A model is proposed suggesting that the functional utility of bulimic behaviors might be in counteracting the negative emotions associated with borderline symptoms. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 30: 434–440, 2001.
Self‐healing in networks with multiple reliability classes
Authors: Kitami Tokuhiro , Takasawa Jun
Published: August 2002

Self‐healing has been investigated as a technique for efficient path failure restoration in VP‐based networks. This paper discusses self‐healing in networks with multiple reliability classes, and evaluates restoration performance of different failure recovery procedures that introduce priority orders in the failure recovery process based on the reliability class for each failed path. The authors present a composite‐type restoration procedure in which preplanned‐type and flooding‐type procedures are combined. This paper also presents a bumping added‐type restoration procedure. The authors evaluated the performance of the above proposed techniques assuming various failure modes. The simulation results revealed that the proposed methods show improved performance. In addition, we propose an enhanced technique that introduces a subsidiary priority criterion in the paths belonging to the same reliability class, in order to increase the number of paths to be recovered. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(7): 1–17, 2001
An enlargement method of digital images based on Laplacian pyramid representation
Authors: Takahashi Yasumasa , Taguchi Akira
Published: August 2002

Since the enlargement of digital images is carried out by insertion of sample points, the Nyquist frequency of the enlarged image is naturally larger than that prior to enlargement. Hence, estimation of unknown higher‐frequency components is required for enlargement of digital images. On the other hand, Laplacian pyramid representation is widely known as a layered expression of the images. Based on this Laplacian pyramid representation, the unknown higher‐frequency components to be estimated at the time of enlargement of digital images correspond to the unknown higher‐resolution Laplacian components. There is strong correlation between the Laplacian images at different layers. Specifically, the edge information spans several continuous layers as zero crossings and hence appears at the same location. Differences in the layers are recognized as differences in gradient near the zero crossing. In this paper, this property is directly used to provide a method of obtaining unknown higher‐resolution Laplacian images from low‐resolution Laplacian images (direct method). The results of enlargement by the direct method are particularly good in the smoothly varying parts of the images, but there are some difficulties in enlargement at the edges and of details. The paper proposes a hybrid method in which the direct method is combined with the method of Greenspan, with excellent enlargement results at edges and details, after the enlargement of images by estimation of the unknown higher‐resolution Laplacian images as in the direct method. It is demonstrated by many application examples that this hybrid method is reasonably simple and is superior numerically and subjectively. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(6): 40–49, 2001
An Algorithm for Iteratively Refining the Interval Including the Solution Set of Parameter‐Dependent Nonlinear Equations
Authors: Kanzawa Yuchi , Kashiwagi Masahide , Oishi Shin'ichi
Published: August 2002

An algorithm for arbitrarily minimizing the width of the interval which does not contain the solutions from the interval which contains the solutions of equations using nonlinear functions in which the dimension of the definition domain is greater than the dimension of the value range is proposed in this paper. In addition, the effectiveness of the proposed algorithm is shown using specific numerical examples. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(4): 39–44, 2002
Multidimensional Directed Information and Its Application
Authors: Sakata Osamu , Shiina Tsuyoshi , Saito Yoichi
Published: August 2002

Brain waves are derived as multiple time‐series signals from electrodes placed on various sites on the scalp. If the flow of information among these multiple sites can be visualized, it will be useful in obtaining a clue to the objective interpretation of brain activity, or in diagnosing the existence of failures of brain function. Directed information analysis has been proposed as a means of causality analysis in which the flow of information among the signals is investigated. The method notes an arbitrary two of a large number of time series, and examines the flow of information between these. When three or more signal series exist, they are in general related to each other. Consequently, even if the causality between two particular series is to be examined, the accurate flow of information cannot be determined unless the effect of another series is considered. Consequently, the authors have proposed multidimensional directed information analysis, which is an extension of directed information analysis. This paper tries to verify the effectiveness of multidimensional directed information analysis by simulation. Then, the method is applied to the brain waves of a healthy subject and a patient with a cerebral organic disorder, and it is verified that there is a difference, reflecting the presence of disease in the sense of information propagation in the cortex. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(4): 45–55, 2002
Image restoration by using multiple Wiener filters
Authors: Nishimiya Ryohei , Taguchi Akira
Published: August 2002

We propose a method that uses multiple Wiener filters based on region decomposition to restore natural images degraded by Gaussian noise. Usually, a Wiener filter is designed to be optimal for the entire image. However, because natural images are highly nonstationary, an effective method switches to the optimum filter for each local region. In this paper, we consider a method that repeatedly decomposes into four equal parts, the four regions obtained by dividing an image into four equal parts, and design a Wiener filter for each region. As the regions become smaller, the desired Wiener filter is not necessarily obtained because of the drop in reliability of the correlation functions used to find the Wiener filter. Therefore, we first study to what extent the restoration accuracy of a known source image is improved by ideal decomposition that repeatedly decomposes only regions where the accuracy will improve. We then present a practical method that sufficiently improves the restoration accuracy even when the source image is unknown. We next merge similar decomposed regions and investigate how many classes are essential for the decomposition and these class boundaries. Thus, we verify that the proposed decomposition implicitly accounts for properties such as the contours in the image and clearly demonstrate the suitability of the proposed method. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(8): 51–61, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1112
A method for predicting psychological response to meaningless random noise when listening to audio signals based on a bi‐variate membership function
Authors: Yamaguchi Shizuma , Saeki Tetsuro , Oimatsu Kensei
Published: August 2002

It is important for the design of a comfortable sound environment to grasp the way in which the sound pressure levels and power spectral characteristics of the audio signal are related to those of external noise and how they influence the psychological response that arises at the time of exposure to noise. In this paper, a method for estimating and/or predicting the human psychological response to the external noise when listening to an audio signal is proposed based on fuzzy set theory. Concretely, when persons listening to an audio signal are exposed to meaningless external random noise, the fuzzy relation between the sound pressure levels and power spectral characteristics of the audio signal and noise is approximately given a bi‐variate membership function with support of the signal‐to‐noise ratio. Next, a method for evaluating the psychological response is proposed by introducing the concept of fuzzy probability. Finally, the validity and applicability of the proposed method are confirmed experimentally by application to real observational data. The experimental results are in good agreement with the theory. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(8): 62–68, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1113
Generalizations of image resolution conversions using 8‐point inverse DCT
Authors: Kojima Kazuhiro , Kiya Hitoshi
Published: August 2002

The resolution conversion method using DCT is now the mainstream of image compression techniques. This paper extends the conventional method in which the inverse DCT with the same number of points as that of DCT (3 points) in the encoding is used, and generalizes the procedure. More precisely, the resolution conversion is made executable with conversion factors of not only integers but also rational numbers. Thus, a greater degree of freedom is provided in selecting the filter for controlling the image quality. As a result, resolution conversion with any rational number factor can be performed by the 3‐point inverse DCT, and the filter characteristics can be selected according to the image properties. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(9): 58–68, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1119
Characteristics of short primary linear induction motor with a partially adopted wound secondary member
Authors: Kamiya Yushi , Fukaya Koji , Woojin Jeon , Onuki Takashi
Published: August 2002

This paper describes single‐sided linear induction motors (LIMs) with a short primary member. In these machines a solid‐plate conductor is usually used for the secondary. We here propose the partial adoption of wound secondary members in LIMs. The characteristics of such machines are summarized as follows.

1. Basic characteristics: The wound secondary shortens the magnetic clearance and makes the characteristics of the machine superior to those of the solid‐plate conductor version. In addition, we can improve the thrust and efficiency characteristics by applying the proportional shifting method.

2. Primary and secondary winding scheme: Parallel connection is appropriate for the primary and independently shorted‐circuit scheme in order to obtain stable performance.

3. Transient phenomena at the boundary between the wound secondary and the solid‐plate secondary: Undesirable phenomena develop at the boundary, especially at the end of the solid‐plate conductor. Thus, we propose a novel boundary structure that yields stable transient performance. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 48–55, 2001
Adaptive noise reduction by using cascaded sandglass‐type neural networks
Authors: Yoshimura Hiroki , Shimizu Tadaaki , Isu Naoki , Sugata Kazuhiro
Published: August 2002

An adaptive noise reduction filter composed of cascaded sandglass‐type neural networks (CSNNRF) is proposed. A given number of unit sandglass‐type neural networks (SNN), each of which has a three‐layer structure and consists of the same number of neural units in the input and the output layers and a single neural unit the hidden layer, are connected in cascade. The number of unit SNNs is adaptively determined so as to be equal to a rank of covariance matrix of an original noise‐free signal (signal component). Outputs of hidden layer units in individual unit SNNs, whose variances are equivalent to eigenvalues of the covariance matrix of the observed signal, are statistically compared by use of ANOVA (analysis of variance) to estimate the rank. When a CSNNRF is composed of the number of unit SNNs equal to the rank, the observed signal is filtered without any loss of signal component while noise component is maximally reduced. It was shown by computer experiments that the rank was almost always estimated accurately in an adaptive manner, and that noise reduction from the signal was carried out optimally. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 37–46, 2001
Effects of winding connections on characteristics of a five‐phase stepping motor
Authors: Yokozuka Tsutomu , Ishikawa Takeo , Harada Takashi , Minami Toshinari , Shibuya Makoto
Published: August 2002

A method for calculating the single‐step response of five‐phase hybrid stepping motors is obtained. The effects of winding connecting methods—(1) star‐bipolar SB, (2) pentagon PD, and (3) new pentagon NP—on the single‐step response are investigated. By application of the above calculation method, the continuous rotating characteristics are studied. It is found that the maximum slewing pulse rate of NP is higher than that of SB and PD connections, and that the variation of the rotor speed at high speed with the SB and PD connections is larger than that with the NP connection. The effects of the current waveform on the oscillation characteristics and relations between the current waveform and the winding connections are investigated. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 47–56, 2001
Production of nonequilibrium plasma and MHD interaction in disk MHD channel
Authors: Oda Noritaka , Suzuki Masafumi , Fujino Takayasu , Okuno Yoshihiro , Yamasaki Hiroyuki
Published: August 2002

The production of nonequilibrium plasma and the fluid flow with the MHD interaction are examined experimentally with a shock‐tube driven disk channel with no loading electrodes. For low magnetic flux density and low seed fraction, where nonuniform and unsteady plasma is generated, the static pressure decreases monotonically in the radial direction, although the pressure increases in the entire region of the channel in comparison with the value under no MHD interaction. For magnetic flux density and seed fraction above some critical values, a fairly uniform plasma is produced. The static pressure, however, is found to increase abruptly in the channel and the total pressure is considerably reduced at the location, where the abrupt pressure increase occurs. These facts imply that steady and uniform plasma should be produced without locally constricted strong Lorentz force to improve the adiabatic efficiency of a disk MHD generator. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 42–49, 2002; DOI 10.1002/eej.1137
Magnetic levitation control of a thin steel plate by means of gap length correction commands
Authors: Nakagawa Toshiko , Hama Mikio
Published: August 2002

The techniques of maglev are expected to apply not only to railways but also to various fields of industry. As one such field, the application to process lines of steel plates is now in the limelight. However, as the levitated steel plates are thin and flat in this kind of maglev system, any guide force in conventional maglev systems is not induced. Therefore, once the steel plates levitate, the gravity force soon makes them sideslip if the electromagnets are slantingly attached to the base table. This paper deals with a control method that allows the steel plate to levitate stably and horizontally and deals with various experimental results. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 52–59, 2001
Enforcement of environmental charges: some economic aspects and evidence from the German Waste Water Charge
Authors: Gawel Erik
Published: August 2002

Enforcement problems are usually analysed with respect to command‐and‐control measures of environmental regulation. The recognition that any environmental policy instrument entails an enforcement problem in principle is basic to a comparative analysis of enforcement effects. This paper deals with the comparative enforcement effects of charges: How does enforcement of a charge function? Which problems occur particularly in the enforcement of charges? Could enforcement be facilitated by a specific construction of charge laws? Are economic concepts of charge enforceable at all, and if so, under what conditions? Are charges more readily enforceable than other instruments? Therefore, some economic theory assessments of enforcement processes are presented first. In a third part, the paper sheds light on the practical experience made with the enforcement of the German Waste Water Charge. It is argued that the well worn thesis of an enforcement‐friendly ‘self‐control’ of market instruments is based on unrealistic assumptions. Whether against this background enforcement of environmental policy can be facilitated by an increased application use of charges must be viewed sceptically in an overall assessment of the problematic. Moreover, the transition from allocative control tasks to fiscal environmental charges may well be a symptom of rather than a contribution to the solution of the political and administrative crisis of enforcement. Especially for charges, the crucial question seems to be the political implementation rather than concrete enforcement by local authorities. Copyright © 2001 John Wiley & Sons, Ltd. and ERP Environment
XPA protein alters the specificity of ultraviolet light–induced mutagenesis in vitro
Authors: King Nicole M. , Oakley Gregory G. , Medvedovic Mario , Dixon Kathleen
Published: August 2002

Studies of ultraviolet (UV) light mutagenesis have demonstrated mutations at common sites in the target genes of shuttle vector plasmids replicated in cultured cells or by cellular extracts. The reasons for the specific pattern of mutagenesis are largely unknown. We have examined the specificity of UV‐induced mutagenesis by replicating plasmid pLS189, irradiated with 40 J/m2 UVC or unirradiated, in either xeroderma pigmentosum group A (XP‐A) or HeLa cellular extracts. The XP‐A extract displayed slightly lower replication ability, but produced a higher mutant frequency, compared to that of HeLa extract. Use of irradiated plasmid inhibited replication by an average of 63% and increased the mutant frequency by an average of 16.7‐fold. Analysis of mutation spectra revealed nonrandom patterns of mutagenesis that differed significantly between HeLa and XP‐A extracts. In comparison to HeLa extract, replication in XP‐A extract resulted in lower frequencies of GC → AT transitions and tandem double‐base substitutions, and a higher frequency of deletions. Replication in HeLa extract produced hotspots at positions 100, 108, and 156 that were not produced by XP‐A extract. Furthermore, XP‐A extract produced hotspots at positions 124, 133, and 164, sites not characteristic of previous UV‐induced mutagenesis studies using XPA‐expressing cells. Addition of purified XPA protein to reactions containing XP‐A extract altered each of these parameters, including loss of the hotspots at positions 124 and 133, to yield a more HeLa‐like spectrum. These results indicate a previously uncharacterized role of the XPA protein in influencing the specificity of UV‐induced mutagenesis during DNA replication. Environ. Mol. Mutagen. 37:329–339, 2001 © 2001 Wiley‐Liss, Inc.
Nitric oxide donors induce large‐scale deletion mutations in human lymphoblastoid cells: Implications for mutations in T‐lymphocytes from arthritis patients
Authors: Grant Donna D. , Goldstein Rose , Karsh Jacob , Birnboim H. Chaim
Published: August 2002

Rheumatoid arthritis (RA) is an inflammatory disease in which high levels of reactive nitrogen oxygen species (RNOS) may be present in the affected joints. RNOS are known to produce small‐scale mutational events (transitions, transversions, small insertions, and small deletions) but the ability of these compounds to cause deletion of large segments of genomic DNA has not been previously determined. To address this question, a human lymphoblastoid cell line (WIL2‐NS) was exposed to nitric oxide (NO)–donating drugs and hypoxanthine phosphoribosyltransferase (hprt)–negative clones were selected and analyzed by multiplex‐PCR. Large‐scale deletions accounted for 60–80% of hprt mutations arising in drug‐treated cultures compared to 12% in untreated cultures (P‐values of 0.006 and 0.0001, respectively, in two experiments). Deletion mutations in untreated cultures affected exon 9, whereas 75% of drug‐induced deletion mutations affected exons 2, 3, and 9, and the remainder were very large, ranging from 26 to 1200 kbp. To compare this spectrum of NO‐induced mutations in a lymphoblastoid line to that arising in vivo in arthritis patients, T‐cells from RA patients, osteoarthritis (OA) patients, and controls were cloned and similarly analyzed. We previously showed that the overall frequency of Hprt mutant clones from patients is appreciably elevated compared to that of control subjects. Large‐scale hprt deletions (0.5 to >26 kb) were detected in mutant T‐cell clones from both RA and OA patients and also from control subjects. A total of 54 mutant clones from 16 RA patients and 19 mutant clones from 6 OA patients were studied. Of these, 6 clones (from 3 RA and 1 OA patient) had suffered large‐scale deletions. A total of 9 control subjects were studied and 62 mutant clones were obtained. Of these, 19 had suffered large‐scale deletions, arising in 7 of 9 control subjects. In conclusion, (1) RNOS are capable of inducing large‐scale deletion mutations in a human lymphoblastoid cell line and (2) large‐scale deletion mutations were found in 10–30% of T‐cell clones from RA and OA patients and controls, which we hypothesize may be induced by RNOS. Environ. Mol. Mutagen. 38:261–267, 2001. © 2001 Wiley‐Liss, Inc.
Temperature trends in the United States
Authors: Lund Robert , Seymour Lynne , Kafadar Karen
Published: August 2002

Linear temperature trends and their uncertainties from data at 359 recording stations in the contiguous United States are investigated. A statistical model is developed that accounts for changes in the site location of each station, the seasonal means and variances inherent in monthly temperature series, and the temporal and spatial correlations found in such data. Least squares estimates of the seasonal trend parameters in the model are derived, as well as appropriate standard errors that take into account the site changes, periodicities and temporal correlations present in the data. The estimates and their standard errors at each station are then spatially analyzed to identify geographical patterns of temperature change across the United States. Copyright © 2001 John Wiley & Sons, Ltd.
Bootstrap calibration to improve the reliability of tests to compare sample means and variances
Authors: Francis R. I. C. Chris , Manly Bryan F. J.
Published: August 2002

The comparison of several sample means to see whether they differ significantly is a common analysis, which is not straightforward when the samples may be from non‐normal distributions with different variances. A recent study found that a randomization test that attempts to approximate the distribution of F‐statistics from one‐ and two‐factor analysis of variance in the presence of unequal population variances was the best of 12 alternative tests considered. However, it sometimes suffered from excess size with data from extremely non‐normal distributions. In the present article a method for improving the robustness of the test by bootstrap calibration is described for one‐factor analysis of variance, and shown to be effective by a simulation study. The method is also applied with Levene's test for unequal variance by randomization. In this case the test is very robust without calibration, and calibration does not improve it. Copyright © 2001 John Wiley & Sons, Ltd.
Testing of the SIBERIA landscape evolution model using the Tin Camp Creek, Northern Territory, Australia, field catchment
Authors: Hancock G. R. , Willgoose G. R. , Evans K. G.
Published: August 2002

The SIBERIA landscape evolution model was used to simulate the geomorphic development of the Tin Camp Creek natural catchment over geological time. Measured hydrology, erosion and geomorphic data were used to calibrate the SIBERIA model, which was then used to make independent predictions of the landform geomorphology of the study site. The catchment, located in the Northern Territory, Australia is relatively untouched by Europeans so the hydrological and erosion processes that shaped the area can be assumed to be the same today as they have been in the past, subject to the caveats regarding long‐term climate fluctuation. A qualitative, or visual comparison between the natural and simulated catchments indicates that SIBERIA can match hillslope length and hillslope profile of the natural catchments. A comparison of geomorphic and hydrological statistics such as the hypsometric curve, width function, cumulative area distribution and area–slope relationship indicates that SIBERIA can model the geomorphology of the selected Tin Camp Creek catchments. Copyright 2002 © Environmental Research Institute of the Supervising Scientist, Commonwealth of Australia.
Conclusions: Implications for policy reform and policy research
Authors: Foster E. Michael , Julnes George
Published: August 2002

This chapter summarizes the findings from the studies presented in this volume, examines the broader lessons for research on leavers, and identifies next steps for policymakers and researchers.
The changing face of responsive evaluation: A postmodern rejoinder
Authors: Stronach Ian
Published: August 2002

The meanings of responsive evaluation are critiqued and reinterpreted through the lenses of loyalty and betrayal, direction and indirection, openings and closures. The hidden and unspeakable aspects of responsive evaluation are thereby deconstructively revealed.
CBUF model II applied to exemplary NZ furniture (NZ‐CBUF)
Authors: Enright Patrick A. , Fleischmann Charles M. , Vandevelde Paul
Published: August 2002

In the comprehensive EC‐sponsored initiative, CBUF (combustion behaviour of upholstered furniture), three models were developed for furniture fire prediction. The second of these models, CBUF model II, is based on an area convolution technique with expressions of burning area over time determined for furniture types. In this paper, the CBUF model II was applied to a set of exemplary New Zealand (NZ) upholstered furniture items. CBUF Model II was not found to predict with goodness the combustion behaviour of the NZ upholstered furniture. Copyright © 2001 John Wiley & Sons, Ltd.